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/>. */
27 #include "breakpoint.h"
31 #include "target-connection.h"
32 #include "gdbthread.h"
39 #include "observable.h"
44 #include "mi/mi-common.h"
45 #include "event-top.h"
47 #include "record-full.h"
48 #include "inline-frame.h"
50 #include "tracepoint.h"
54 #include "completer.h"
55 #include "target-descriptions.h"
56 #include "target-dcache.h"
59 #include "gdbsupport/event-loop.h"
60 #include "thread-fsm.h"
61 #include "gdbsupport/enum-flags.h"
62 #include "progspace-and-thread.h"
63 #include "gdbsupport/gdb_optional.h"
64 #include "arch-utils.h"
65 #include "gdbsupport/scope-exit.h"
66 #include "gdbsupport/forward-scope-exit.h"
67 #include "gdbsupport/gdb_select.h"
68 #include <unordered_map>
69 #include "async-event.h"
70 #include "gdbsupport/selftest.h"
71 #include "scoped-mock-context.h"
72 #include "test-target.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;
108 infrun_debug_printf_1 (const char *func_name
, const char *fmt
, ...)
112 debug_prefixed_vprintf ("infrun", func_name
, fmt
, ap
);
119 infrun_async (int enable
)
121 if (infrun_is_async
!= enable
)
123 infrun_is_async
= enable
;
125 infrun_debug_printf ("enable=%d", enable
);
128 mark_async_event_handler (infrun_async_inferior_event_token
);
130 clear_async_event_handler (infrun_async_inferior_event_token
);
137 mark_infrun_async_event_handler (void)
139 mark_async_event_handler (infrun_async_inferior_event_token
);
142 /* When set, stop the 'step' command if we enter a function which has
143 no line number information. The normal behavior is that we step
144 over such function. */
145 bool step_stop_if_no_debug
= false;
147 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
148 struct cmd_list_element
*c
, const char *value
)
150 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
153 /* proceed and normal_stop use this to notify the user when the
154 inferior stopped in a different thread than it had been running
157 static ptid_t previous_inferior_ptid
;
159 /* If set (default for legacy reasons), when following a fork, GDB
160 will detach from one of the fork branches, child or parent.
161 Exactly which branch is detached depends on 'set follow-fork-mode'
164 static bool detach_fork
= true;
166 bool debug_displaced
= false;
168 show_debug_displaced (struct ui_file
*file
, int from_tty
,
169 struct cmd_list_element
*c
, const char *value
)
171 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
174 unsigned int debug_infrun
= 0;
176 show_debug_infrun (struct ui_file
*file
, int from_tty
,
177 struct cmd_list_element
*c
, const char *value
)
179 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
183 /* Support for disabling address space randomization. */
185 bool disable_randomization
= true;
188 show_disable_randomization (struct ui_file
*file
, int from_tty
,
189 struct cmd_list_element
*c
, const char *value
)
191 if (target_supports_disable_randomization ())
192 fprintf_filtered (file
,
193 _("Disabling randomization of debuggee's "
194 "virtual address space is %s.\n"),
197 fputs_filtered (_("Disabling randomization of debuggee's "
198 "virtual address space is unsupported on\n"
199 "this platform.\n"), file
);
203 set_disable_randomization (const char *args
, int from_tty
,
204 struct cmd_list_element
*c
)
206 if (!target_supports_disable_randomization ())
207 error (_("Disabling randomization of debuggee's "
208 "virtual address space is unsupported on\n"
212 /* User interface for non-stop mode. */
214 bool non_stop
= false;
215 static bool non_stop_1
= false;
218 set_non_stop (const char *args
, int from_tty
,
219 struct cmd_list_element
*c
)
221 if (target_has_execution
)
223 non_stop_1
= non_stop
;
224 error (_("Cannot change this setting while the inferior is running."));
227 non_stop
= non_stop_1
;
231 show_non_stop (struct ui_file
*file
, int from_tty
,
232 struct cmd_list_element
*c
, const char *value
)
234 fprintf_filtered (file
,
235 _("Controlling the inferior in non-stop mode is %s.\n"),
239 /* "Observer mode" is somewhat like a more extreme version of
240 non-stop, in which all GDB operations that might affect the
241 target's execution have been disabled. */
243 bool observer_mode
= false;
244 static bool observer_mode_1
= false;
247 set_observer_mode (const char *args
, int from_tty
,
248 struct cmd_list_element
*c
)
250 if (target_has_execution
)
252 observer_mode_1
= observer_mode
;
253 error (_("Cannot change this setting while the inferior is running."));
256 observer_mode
= observer_mode_1
;
258 may_write_registers
= !observer_mode
;
259 may_write_memory
= !observer_mode
;
260 may_insert_breakpoints
= !observer_mode
;
261 may_insert_tracepoints
= !observer_mode
;
262 /* We can insert fast tracepoints in or out of observer mode,
263 but enable them if we're going into this mode. */
265 may_insert_fast_tracepoints
= true;
266 may_stop
= !observer_mode
;
267 update_target_permissions ();
269 /* Going *into* observer mode we must force non-stop, then
270 going out we leave it that way. */
273 pagination_enabled
= 0;
274 non_stop
= non_stop_1
= true;
278 printf_filtered (_("Observer mode is now %s.\n"),
279 (observer_mode
? "on" : "off"));
283 show_observer_mode (struct ui_file
*file
, int from_tty
,
284 struct cmd_list_element
*c
, const char *value
)
286 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
289 /* This updates the value of observer mode based on changes in
290 permissions. Note that we are deliberately ignoring the values of
291 may-write-registers and may-write-memory, since the user may have
292 reason to enable these during a session, for instance to turn on a
293 debugging-related global. */
296 update_observer_mode (void)
298 bool newval
= (!may_insert_breakpoints
299 && !may_insert_tracepoints
300 && may_insert_fast_tracepoints
304 /* Let the user know if things change. */
305 if (newval
!= observer_mode
)
306 printf_filtered (_("Observer mode is now %s.\n"),
307 (newval
? "on" : "off"));
309 observer_mode
= observer_mode_1
= newval
;
312 /* Tables of how to react to signals; the user sets them. */
314 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
315 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
316 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
318 /* Table of signals that are registered with "catch signal". A
319 non-zero entry indicates that the signal is caught by some "catch
321 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
323 /* Table of signals that the target may silently handle.
324 This is automatically determined from the flags above,
325 and simply cached here. */
326 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
328 #define SET_SIGS(nsigs,sigs,flags) \
330 int signum = (nsigs); \
331 while (signum-- > 0) \
332 if ((sigs)[signum]) \
333 (flags)[signum] = 1; \
336 #define UNSET_SIGS(nsigs,sigs,flags) \
338 int signum = (nsigs); \
339 while (signum-- > 0) \
340 if ((sigs)[signum]) \
341 (flags)[signum] = 0; \
344 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
345 this function is to avoid exporting `signal_program'. */
348 update_signals_program_target (void)
350 target_program_signals (signal_program
);
353 /* Value to pass to target_resume() to cause all threads to resume. */
355 #define RESUME_ALL minus_one_ptid
357 /* Command list pointer for the "stop" placeholder. */
359 static struct cmd_list_element
*stop_command
;
361 /* Nonzero if we want to give control to the user when we're notified
362 of shared library events by the dynamic linker. */
363 int stop_on_solib_events
;
365 /* Enable or disable optional shared library event breakpoints
366 as appropriate when the above flag is changed. */
369 set_stop_on_solib_events (const char *args
,
370 int from_tty
, struct cmd_list_element
*c
)
372 update_solib_breakpoints ();
376 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
377 struct cmd_list_element
*c
, const char *value
)
379 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
383 /* Nonzero after stop if current stack frame should be printed. */
385 static int stop_print_frame
;
387 /* This is a cached copy of the target/ptid/waitstatus of the last
388 event returned by target_wait()/deprecated_target_wait_hook().
389 This information is returned by get_last_target_status(). */
390 static process_stratum_target
*target_last_proc_target
;
391 static ptid_t target_last_wait_ptid
;
392 static struct target_waitstatus target_last_waitstatus
;
394 void init_thread_stepping_state (struct thread_info
*tss
);
396 static const char follow_fork_mode_child
[] = "child";
397 static const char follow_fork_mode_parent
[] = "parent";
399 static const char *const follow_fork_mode_kind_names
[] = {
400 follow_fork_mode_child
,
401 follow_fork_mode_parent
,
405 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
407 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
408 struct cmd_list_element
*c
, const char *value
)
410 fprintf_filtered (file
,
411 _("Debugger response to a program "
412 "call of fork or vfork is \"%s\".\n"),
417 /* Handle changes to the inferior list based on the type of fork,
418 which process is being followed, and whether the other process
419 should be detached. On entry inferior_ptid must be the ptid of
420 the fork parent. At return inferior_ptid is the ptid of the
421 followed inferior. */
424 follow_fork_inferior (bool follow_child
, bool detach_fork
)
427 ptid_t parent_ptid
, child_ptid
;
429 has_vforked
= (inferior_thread ()->pending_follow
.kind
430 == TARGET_WAITKIND_VFORKED
);
431 parent_ptid
= inferior_ptid
;
432 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
435 && !non_stop
/* Non-stop always resumes both branches. */
436 && current_ui
->prompt_state
== PROMPT_BLOCKED
437 && !(follow_child
|| detach_fork
|| sched_multi
))
439 /* The parent stays blocked inside the vfork syscall until the
440 child execs or exits. If we don't let the child run, then
441 the parent stays blocked. If we're telling the parent to run
442 in the foreground, the user will not be able to ctrl-c to get
443 back the terminal, effectively hanging the debug session. */
444 fprintf_filtered (gdb_stderr
, _("\
445 Can not resume the parent process over vfork in the foreground while\n\
446 holding the child stopped. Try \"set detach-on-fork\" or \
447 \"set schedule-multiple\".\n"));
453 /* Detach new forked process? */
456 /* Before detaching from the child, remove all breakpoints
457 from it. If we forked, then this has already been taken
458 care of by infrun.c. If we vforked however, any
459 breakpoint inserted in the parent is visible in the
460 child, even those added while stopped in a vfork
461 catchpoint. This will remove the breakpoints from the
462 parent also, but they'll be reinserted below. */
465 /* Keep breakpoints list in sync. */
466 remove_breakpoints_inf (current_inferior ());
469 if (print_inferior_events
)
471 /* Ensure that we have a process ptid. */
472 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
474 target_terminal::ours_for_output ();
475 fprintf_filtered (gdb_stdlog
,
476 _("[Detaching after %s from child %s]\n"),
477 has_vforked
? "vfork" : "fork",
478 target_pid_to_str (process_ptid
).c_str ());
483 struct inferior
*parent_inf
, *child_inf
;
485 /* Add process to GDB's tables. */
486 child_inf
= add_inferior (child_ptid
.pid ());
488 parent_inf
= current_inferior ();
489 child_inf
->attach_flag
= parent_inf
->attach_flag
;
490 copy_terminal_info (child_inf
, parent_inf
);
491 child_inf
->gdbarch
= parent_inf
->gdbarch
;
492 copy_inferior_target_desc_info (child_inf
, parent_inf
);
494 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
496 set_current_inferior (child_inf
);
497 switch_to_no_thread ();
498 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
499 push_target (parent_inf
->process_target ());
500 thread_info
*child_thr
501 = add_thread_silent (child_inf
->process_target (), child_ptid
);
503 /* If this is a vfork child, then the address-space is
504 shared with the parent. */
507 child_inf
->pspace
= parent_inf
->pspace
;
508 child_inf
->aspace
= parent_inf
->aspace
;
512 /* The parent will be frozen until the child is done
513 with the shared region. Keep track of the
515 child_inf
->vfork_parent
= parent_inf
;
516 child_inf
->pending_detach
= 0;
517 parent_inf
->vfork_child
= child_inf
;
518 parent_inf
->pending_detach
= 0;
520 /* Now that the inferiors and program spaces are all
521 wired up, we can switch to the child thread (which
522 switches inferior and program space too). */
523 switch_to_thread (child_thr
);
527 child_inf
->aspace
= new_address_space ();
528 child_inf
->pspace
= new program_space (child_inf
->aspace
);
529 child_inf
->removable
= 1;
530 set_current_program_space (child_inf
->pspace
);
531 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
533 /* solib_create_inferior_hook relies on the current
535 switch_to_thread (child_thr
);
537 /* Let the shared library layer (e.g., solib-svr4) learn
538 about this new process, relocate the cloned exec, pull
539 in shared libraries, and install the solib event
540 breakpoint. If a "cloned-VM" event was propagated
541 better throughout the core, this wouldn't be
543 solib_create_inferior_hook (0);
549 struct inferior
*parent_inf
;
551 parent_inf
= current_inferior ();
553 /* If we detached from the child, then we have to be careful
554 to not insert breakpoints in the parent until the child
555 is done with the shared memory region. However, if we're
556 staying attached to the child, then we can and should
557 insert breakpoints, so that we can debug it. A
558 subsequent child exec or exit is enough to know when does
559 the child stops using the parent's address space. */
560 parent_inf
->waiting_for_vfork_done
= detach_fork
;
561 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
566 /* Follow the child. */
567 struct inferior
*parent_inf
, *child_inf
;
568 struct program_space
*parent_pspace
;
570 if (print_inferior_events
)
572 std::string parent_pid
= target_pid_to_str (parent_ptid
);
573 std::string child_pid
= target_pid_to_str (child_ptid
);
575 target_terminal::ours_for_output ();
576 fprintf_filtered (gdb_stdlog
,
577 _("[Attaching after %s %s to child %s]\n"),
579 has_vforked
? "vfork" : "fork",
583 /* Add the new inferior first, so that the target_detach below
584 doesn't unpush the target. */
586 child_inf
= add_inferior (child_ptid
.pid ());
588 parent_inf
= current_inferior ();
589 child_inf
->attach_flag
= parent_inf
->attach_flag
;
590 copy_terminal_info (child_inf
, parent_inf
);
591 child_inf
->gdbarch
= parent_inf
->gdbarch
;
592 copy_inferior_target_desc_info (child_inf
, parent_inf
);
594 parent_pspace
= parent_inf
->pspace
;
596 process_stratum_target
*target
= parent_inf
->process_target ();
599 /* Hold a strong reference to the target while (maybe)
600 detaching the parent. Otherwise detaching could close the
602 auto target_ref
= target_ops_ref::new_reference (target
);
604 /* If we're vforking, we want to hold on to the parent until
605 the child exits or execs. At child exec or exit time we
606 can remove the old breakpoints from the parent and detach
607 or resume debugging it. Otherwise, detach the parent now;
608 we'll want to reuse it's program/address spaces, but we
609 can't set them to the child before removing breakpoints
610 from the parent, otherwise, the breakpoints module could
611 decide to remove breakpoints from the wrong process (since
612 they'd be assigned to the same address space). */
616 gdb_assert (child_inf
->vfork_parent
== NULL
);
617 gdb_assert (parent_inf
->vfork_child
== NULL
);
618 child_inf
->vfork_parent
= parent_inf
;
619 child_inf
->pending_detach
= 0;
620 parent_inf
->vfork_child
= child_inf
;
621 parent_inf
->pending_detach
= detach_fork
;
622 parent_inf
->waiting_for_vfork_done
= 0;
624 else if (detach_fork
)
626 if (print_inferior_events
)
628 /* Ensure that we have a process ptid. */
629 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
631 target_terminal::ours_for_output ();
632 fprintf_filtered (gdb_stdlog
,
633 _("[Detaching after fork from "
635 target_pid_to_str (process_ptid
).c_str ());
638 target_detach (parent_inf
, 0);
642 /* Note that the detach above makes PARENT_INF dangling. */
644 /* Add the child thread to the appropriate lists, and switch
645 to this new thread, before cloning the program space, and
646 informing the solib layer about this new process. */
648 set_current_inferior (child_inf
);
649 push_target (target
);
652 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
654 /* If this is a vfork child, then the address-space is shared
655 with the parent. If we detached from the parent, then we can
656 reuse the parent's program/address spaces. */
657 if (has_vforked
|| detach_fork
)
659 child_inf
->pspace
= parent_pspace
;
660 child_inf
->aspace
= child_inf
->pspace
->aspace
;
666 child_inf
->aspace
= new_address_space ();
667 child_inf
->pspace
= new program_space (child_inf
->aspace
);
668 child_inf
->removable
= 1;
669 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
670 set_current_program_space (child_inf
->pspace
);
671 clone_program_space (child_inf
->pspace
, parent_pspace
);
673 /* Let the shared library layer (e.g., solib-svr4) learn
674 about this new process, relocate the cloned exec, pull in
675 shared libraries, and install the solib event breakpoint.
676 If a "cloned-VM" event was propagated better throughout
677 the core, this wouldn't be required. */
678 solib_create_inferior_hook (0);
681 switch_to_thread (child_thr
);
684 return target_follow_fork (follow_child
, detach_fork
);
687 /* Tell the target to follow the fork we're stopped at. Returns true
688 if the inferior should be resumed; false, if the target for some
689 reason decided it's best not to resume. */
694 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
695 bool should_resume
= true;
696 struct thread_info
*tp
;
698 /* Copy user stepping state to the new inferior thread. FIXME: the
699 followed fork child thread should have a copy of most of the
700 parent thread structure's run control related fields, not just these.
701 Initialized to avoid "may be used uninitialized" warnings from gcc. */
702 struct breakpoint
*step_resume_breakpoint
= NULL
;
703 struct breakpoint
*exception_resume_breakpoint
= NULL
;
704 CORE_ADDR step_range_start
= 0;
705 CORE_ADDR step_range_end
= 0;
706 int current_line
= 0;
707 symtab
*current_symtab
= NULL
;
708 struct frame_id step_frame_id
= { 0 };
709 struct thread_fsm
*thread_fsm
= NULL
;
713 process_stratum_target
*wait_target
;
715 struct target_waitstatus wait_status
;
717 /* Get the last target status returned by target_wait(). */
718 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
720 /* If not stopped at a fork event, then there's nothing else to
722 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
723 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
726 /* Check if we switched over from WAIT_PTID, since the event was
728 if (wait_ptid
!= minus_one_ptid
729 && (current_inferior ()->process_target () != wait_target
730 || inferior_ptid
!= wait_ptid
))
732 /* We did. Switch back to WAIT_PTID thread, to tell the
733 target to follow it (in either direction). We'll
734 afterwards refuse to resume, and inform the user what
736 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
737 switch_to_thread (wait_thread
);
738 should_resume
= false;
742 tp
= inferior_thread ();
744 /* If there were any forks/vforks that were caught and are now to be
745 followed, then do so now. */
746 switch (tp
->pending_follow
.kind
)
748 case TARGET_WAITKIND_FORKED
:
749 case TARGET_WAITKIND_VFORKED
:
751 ptid_t parent
, child
;
753 /* If the user did a next/step, etc, over a fork call,
754 preserve the stepping state in the fork child. */
755 if (follow_child
&& should_resume
)
757 step_resume_breakpoint
= clone_momentary_breakpoint
758 (tp
->control
.step_resume_breakpoint
);
759 step_range_start
= tp
->control
.step_range_start
;
760 step_range_end
= tp
->control
.step_range_end
;
761 current_line
= tp
->current_line
;
762 current_symtab
= tp
->current_symtab
;
763 step_frame_id
= tp
->control
.step_frame_id
;
764 exception_resume_breakpoint
765 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
766 thread_fsm
= tp
->thread_fsm
;
768 /* For now, delete the parent's sr breakpoint, otherwise,
769 parent/child sr breakpoints are considered duplicates,
770 and the child version will not be installed. Remove
771 this when the breakpoints module becomes aware of
772 inferiors and address spaces. */
773 delete_step_resume_breakpoint (tp
);
774 tp
->control
.step_range_start
= 0;
775 tp
->control
.step_range_end
= 0;
776 tp
->control
.step_frame_id
= null_frame_id
;
777 delete_exception_resume_breakpoint (tp
);
778 tp
->thread_fsm
= NULL
;
781 parent
= inferior_ptid
;
782 child
= tp
->pending_follow
.value
.related_pid
;
784 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
785 /* Set up inferior(s) as specified by the caller, and tell the
786 target to do whatever is necessary to follow either parent
788 if (follow_fork_inferior (follow_child
, detach_fork
))
790 /* Target refused to follow, or there's some other reason
791 we shouldn't resume. */
796 /* This pending follow fork event is now handled, one way
797 or another. The previous selected thread may be gone
798 from the lists by now, but if it is still around, need
799 to clear the pending follow request. */
800 tp
= find_thread_ptid (parent_targ
, parent
);
802 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
804 /* This makes sure we don't try to apply the "Switched
805 over from WAIT_PID" logic above. */
806 nullify_last_target_wait_ptid ();
808 /* If we followed the child, switch to it... */
811 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
812 switch_to_thread (child_thr
);
814 /* ... and preserve the stepping state, in case the
815 user was stepping over the fork call. */
818 tp
= inferior_thread ();
819 tp
->control
.step_resume_breakpoint
820 = step_resume_breakpoint
;
821 tp
->control
.step_range_start
= step_range_start
;
822 tp
->control
.step_range_end
= step_range_end
;
823 tp
->current_line
= current_line
;
824 tp
->current_symtab
= current_symtab
;
825 tp
->control
.step_frame_id
= step_frame_id
;
826 tp
->control
.exception_resume_breakpoint
827 = exception_resume_breakpoint
;
828 tp
->thread_fsm
= thread_fsm
;
832 /* If we get here, it was because we're trying to
833 resume from a fork catchpoint, but, the user
834 has switched threads away from the thread that
835 forked. In that case, the resume command
836 issued is most likely not applicable to the
837 child, so just warn, and refuse to resume. */
838 warning (_("Not resuming: switched threads "
839 "before following fork child."));
842 /* Reset breakpoints in the child as appropriate. */
843 follow_inferior_reset_breakpoints ();
848 case TARGET_WAITKIND_SPURIOUS
:
849 /* Nothing to follow. */
852 internal_error (__FILE__
, __LINE__
,
853 "Unexpected pending_follow.kind %d\n",
854 tp
->pending_follow
.kind
);
858 return should_resume
;
862 follow_inferior_reset_breakpoints (void)
864 struct thread_info
*tp
= inferior_thread ();
866 /* Was there a step_resume breakpoint? (There was if the user
867 did a "next" at the fork() call.) If so, explicitly reset its
868 thread number. Cloned step_resume breakpoints are disabled on
869 creation, so enable it here now that it is associated with the
872 step_resumes are a form of bp that are made to be per-thread.
873 Since we created the step_resume bp when the parent process
874 was being debugged, and now are switching to the child process,
875 from the breakpoint package's viewpoint, that's a switch of
876 "threads". We must update the bp's notion of which thread
877 it is for, or it'll be ignored when it triggers. */
879 if (tp
->control
.step_resume_breakpoint
)
881 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
882 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
885 /* Treat exception_resume breakpoints like step_resume breakpoints. */
886 if (tp
->control
.exception_resume_breakpoint
)
888 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
889 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
892 /* Reinsert all breakpoints in the child. The user may have set
893 breakpoints after catching the fork, in which case those
894 were never set in the child, but only in the parent. This makes
895 sure the inserted breakpoints match the breakpoint list. */
897 breakpoint_re_set ();
898 insert_breakpoints ();
901 /* The child has exited or execed: resume threads of the parent the
902 user wanted to be executing. */
905 proceed_after_vfork_done (struct thread_info
*thread
,
908 int pid
= * (int *) arg
;
910 if (thread
->ptid
.pid () == pid
911 && thread
->state
== THREAD_RUNNING
912 && !thread
->executing
913 && !thread
->stop_requested
914 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
916 infrun_debug_printf ("resuming vfork parent thread %s",
917 target_pid_to_str (thread
->ptid
).c_str ());
919 switch_to_thread (thread
);
920 clear_proceed_status (0);
921 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
927 /* Called whenever we notice an exec or exit event, to handle
928 detaching or resuming a vfork parent. */
931 handle_vfork_child_exec_or_exit (int exec
)
933 struct inferior
*inf
= current_inferior ();
935 if (inf
->vfork_parent
)
937 int resume_parent
= -1;
939 /* This exec or exit marks the end of the shared memory region
940 between the parent and the child. Break the bonds. */
941 inferior
*vfork_parent
= inf
->vfork_parent
;
942 inf
->vfork_parent
->vfork_child
= NULL
;
943 inf
->vfork_parent
= NULL
;
945 /* If the user wanted to detach from the parent, now is the
947 if (vfork_parent
->pending_detach
)
949 struct program_space
*pspace
;
950 struct address_space
*aspace
;
952 /* follow-fork child, detach-on-fork on. */
954 vfork_parent
->pending_detach
= 0;
956 scoped_restore_current_pspace_and_thread restore_thread
;
958 /* We're letting loose of the parent. */
959 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
960 switch_to_thread (tp
);
962 /* We're about to detach from the parent, which implicitly
963 removes breakpoints from its address space. There's a
964 catch here: we want to reuse the spaces for the child,
965 but, parent/child are still sharing the pspace at this
966 point, although the exec in reality makes the kernel give
967 the child a fresh set of new pages. The problem here is
968 that the breakpoints module being unaware of this, would
969 likely chose the child process to write to the parent
970 address space. Swapping the child temporarily away from
971 the spaces has the desired effect. Yes, this is "sort
974 pspace
= inf
->pspace
;
975 aspace
= inf
->aspace
;
979 if (print_inferior_events
)
982 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
984 target_terminal::ours_for_output ();
988 fprintf_filtered (gdb_stdlog
,
989 _("[Detaching vfork parent %s "
990 "after child exec]\n"), pidstr
.c_str ());
994 fprintf_filtered (gdb_stdlog
,
995 _("[Detaching vfork parent %s "
996 "after child exit]\n"), pidstr
.c_str ());
1000 target_detach (vfork_parent
, 0);
1003 inf
->pspace
= pspace
;
1004 inf
->aspace
= aspace
;
1008 /* We're staying attached to the parent, so, really give the
1009 child a new address space. */
1010 inf
->pspace
= new program_space (maybe_new_address_space ());
1011 inf
->aspace
= inf
->pspace
->aspace
;
1013 set_current_program_space (inf
->pspace
);
1015 resume_parent
= vfork_parent
->pid
;
1019 /* If this is a vfork child exiting, then the pspace and
1020 aspaces were shared with the parent. Since we're
1021 reporting the process exit, we'll be mourning all that is
1022 found in the address space, and switching to null_ptid,
1023 preparing to start a new inferior. But, since we don't
1024 want to clobber the parent's address/program spaces, we
1025 go ahead and create a new one for this exiting
1028 /* Switch to no-thread while running clone_program_space, so
1029 that clone_program_space doesn't want to read the
1030 selected frame of a dead process. */
1031 scoped_restore_current_thread restore_thread
;
1032 switch_to_no_thread ();
1034 inf
->pspace
= new program_space (maybe_new_address_space ());
1035 inf
->aspace
= inf
->pspace
->aspace
;
1036 set_current_program_space (inf
->pspace
);
1038 inf
->symfile_flags
= SYMFILE_NO_READ
;
1039 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1041 resume_parent
= vfork_parent
->pid
;
1044 gdb_assert (current_program_space
== inf
->pspace
);
1046 if (non_stop
&& resume_parent
!= -1)
1048 /* If the user wanted the parent to be running, let it go
1050 scoped_restore_current_thread restore_thread
;
1052 infrun_debug_printf ("resuming vfork parent process %d",
1055 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1060 /* Enum strings for "set|show follow-exec-mode". */
1062 static const char follow_exec_mode_new
[] = "new";
1063 static const char follow_exec_mode_same
[] = "same";
1064 static const char *const follow_exec_mode_names
[] =
1066 follow_exec_mode_new
,
1067 follow_exec_mode_same
,
1071 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1073 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1074 struct cmd_list_element
*c
, const char *value
)
1076 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1079 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1082 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1084 struct inferior
*inf
= current_inferior ();
1085 int pid
= ptid
.pid ();
1086 ptid_t process_ptid
;
1088 /* Switch terminal for any messages produced e.g. by
1089 breakpoint_re_set. */
1090 target_terminal::ours_for_output ();
1092 /* This is an exec event that we actually wish to pay attention to.
1093 Refresh our symbol table to the newly exec'd program, remove any
1094 momentary bp's, etc.
1096 If there are breakpoints, they aren't really inserted now,
1097 since the exec() transformed our inferior into a fresh set
1100 We want to preserve symbolic breakpoints on the list, since
1101 we have hopes that they can be reset after the new a.out's
1102 symbol table is read.
1104 However, any "raw" breakpoints must be removed from the list
1105 (e.g., the solib bp's), since their address is probably invalid
1108 And, we DON'T want to call delete_breakpoints() here, since
1109 that may write the bp's "shadow contents" (the instruction
1110 value that was overwritten with a TRAP instruction). Since
1111 we now have a new a.out, those shadow contents aren't valid. */
1113 mark_breakpoints_out ();
1115 /* The target reports the exec event to the main thread, even if
1116 some other thread does the exec, and even if the main thread was
1117 stopped or already gone. We may still have non-leader threads of
1118 the process on our list. E.g., on targets that don't have thread
1119 exit events (like remote); or on native Linux in non-stop mode if
1120 there were only two threads in the inferior and the non-leader
1121 one is the one that execs (and nothing forces an update of the
1122 thread list up to here). When debugging remotely, it's best to
1123 avoid extra traffic, when possible, so avoid syncing the thread
1124 list with the target, and instead go ahead and delete all threads
1125 of the process but one that reported the event. Note this must
1126 be done before calling update_breakpoints_after_exec, as
1127 otherwise clearing the threads' resources would reference stale
1128 thread breakpoints -- it may have been one of these threads that
1129 stepped across the exec. We could just clear their stepping
1130 states, but as long as we're iterating, might as well delete
1131 them. Deleting them now rather than at the next user-visible
1132 stop provides a nicer sequence of events for user and MI
1134 for (thread_info
*th
: all_threads_safe ())
1135 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1138 /* We also need to clear any left over stale state for the
1139 leader/event thread. E.g., if there was any step-resume
1140 breakpoint or similar, it's gone now. We cannot truly
1141 step-to-next statement through an exec(). */
1142 thread_info
*th
= inferior_thread ();
1143 th
->control
.step_resume_breakpoint
= NULL
;
1144 th
->control
.exception_resume_breakpoint
= NULL
;
1145 th
->control
.single_step_breakpoints
= NULL
;
1146 th
->control
.step_range_start
= 0;
1147 th
->control
.step_range_end
= 0;
1149 /* The user may have had the main thread held stopped in the
1150 previous image (e.g., schedlock on, or non-stop). Release
1152 th
->stop_requested
= 0;
1154 update_breakpoints_after_exec ();
1156 /* What is this a.out's name? */
1157 process_ptid
= ptid_t (pid
);
1158 printf_unfiltered (_("%s is executing new program: %s\n"),
1159 target_pid_to_str (process_ptid
).c_str (),
1162 /* We've followed the inferior through an exec. Therefore, the
1163 inferior has essentially been killed & reborn. */
1165 breakpoint_init_inferior (inf_execd
);
1167 gdb::unique_xmalloc_ptr
<char> exec_file_host
1168 = exec_file_find (exec_file_target
, NULL
);
1170 /* If we were unable to map the executable target pathname onto a host
1171 pathname, tell the user that. Otherwise GDB's subsequent behavior
1172 is confusing. Maybe it would even be better to stop at this point
1173 so that the user can specify a file manually before continuing. */
1174 if (exec_file_host
== NULL
)
1175 warning (_("Could not load symbols for executable %s.\n"
1176 "Do you need \"set sysroot\"?"),
1179 /* Reset the shared library package. This ensures that we get a
1180 shlib event when the child reaches "_start", at which point the
1181 dld will have had a chance to initialize the child. */
1182 /* Also, loading a symbol file below may trigger symbol lookups, and
1183 we don't want those to be satisfied by the libraries of the
1184 previous incarnation of this process. */
1185 no_shared_libraries (NULL
, 0);
1187 if (follow_exec_mode_string
== follow_exec_mode_new
)
1189 /* The user wants to keep the old inferior and program spaces
1190 around. Create a new fresh one, and switch to it. */
1192 /* Do exit processing for the original inferior before setting the new
1193 inferior's pid. Having two inferiors with the same pid would confuse
1194 find_inferior_p(t)id. Transfer the terminal state and info from the
1195 old to the new inferior. */
1196 inf
= add_inferior_with_spaces ();
1197 swap_terminal_info (inf
, current_inferior ());
1198 exit_inferior_silent (current_inferior ());
1201 target_follow_exec (inf
, exec_file_target
);
1203 inferior
*org_inferior
= current_inferior ();
1204 switch_to_inferior_no_thread (inf
);
1205 push_target (org_inferior
->process_target ());
1206 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1207 switch_to_thread (thr
);
1211 /* The old description may no longer be fit for the new image.
1212 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1213 old description; we'll read a new one below. No need to do
1214 this on "follow-exec-mode new", as the old inferior stays
1215 around (its description is later cleared/refetched on
1217 target_clear_description ();
1220 gdb_assert (current_program_space
== inf
->pspace
);
1222 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1223 because the proper displacement for a PIE (Position Independent
1224 Executable) main symbol file will only be computed by
1225 solib_create_inferior_hook below. breakpoint_re_set would fail
1226 to insert the breakpoints with the zero displacement. */
1227 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1229 /* If the target can specify a description, read it. Must do this
1230 after flipping to the new executable (because the target supplied
1231 description must be compatible with the executable's
1232 architecture, and the old executable may e.g., be 32-bit, while
1233 the new one 64-bit), and before anything involving memory or
1235 target_find_description ();
1237 solib_create_inferior_hook (0);
1239 jit_inferior_created_hook ();
1241 breakpoint_re_set ();
1243 /* Reinsert all breakpoints. (Those which were symbolic have
1244 been reset to the proper address in the new a.out, thanks
1245 to symbol_file_command...). */
1246 insert_breakpoints ();
1248 /* The next resume of this inferior should bring it to the shlib
1249 startup breakpoints. (If the user had also set bp's on
1250 "main" from the old (parent) process, then they'll auto-
1251 matically get reset there in the new process.). */
1254 /* The queue of threads that need to do a step-over operation to get
1255 past e.g., a breakpoint. What technique is used to step over the
1256 breakpoint/watchpoint does not matter -- all threads end up in the
1257 same queue, to maintain rough temporal order of execution, in order
1258 to avoid starvation, otherwise, we could e.g., find ourselves
1259 constantly stepping the same couple threads past their breakpoints
1260 over and over, if the single-step finish fast enough. */
1261 struct thread_info
*step_over_queue_head
;
1263 /* Bit flags indicating what the thread needs to step over. */
1265 enum step_over_what_flag
1267 /* Step over a breakpoint. */
1268 STEP_OVER_BREAKPOINT
= 1,
1270 /* Step past a non-continuable watchpoint, in order to let the
1271 instruction execute so we can evaluate the watchpoint
1273 STEP_OVER_WATCHPOINT
= 2
1275 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1277 /* Info about an instruction that is being stepped over. */
1279 struct step_over_info
1281 /* If we're stepping past a breakpoint, this is the address space
1282 and address of the instruction the breakpoint is set at. We'll
1283 skip inserting all breakpoints here. Valid iff ASPACE is
1285 const address_space
*aspace
;
1288 /* The instruction being stepped over triggers a nonsteppable
1289 watchpoint. If true, we'll skip inserting watchpoints. */
1290 int nonsteppable_watchpoint_p
;
1292 /* The thread's global number. */
1296 /* The step-over info of the location that is being stepped over.
1298 Note that with async/breakpoint always-inserted mode, a user might
1299 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1300 being stepped over. As setting a new breakpoint inserts all
1301 breakpoints, we need to make sure the breakpoint being stepped over
1302 isn't inserted then. We do that by only clearing the step-over
1303 info when the step-over is actually finished (or aborted).
1305 Presently GDB can only step over one breakpoint at any given time.
1306 Given threads that can't run code in the same address space as the
1307 breakpoint's can't really miss the breakpoint, GDB could be taught
1308 to step-over at most one breakpoint per address space (so this info
1309 could move to the address space object if/when GDB is extended).
1310 The set of breakpoints being stepped over will normally be much
1311 smaller than the set of all breakpoints, so a flag in the
1312 breakpoint location structure would be wasteful. A separate list
1313 also saves complexity and run-time, as otherwise we'd have to go
1314 through all breakpoint locations clearing their flag whenever we
1315 start a new sequence. Similar considerations weigh against storing
1316 this info in the thread object. Plus, not all step overs actually
1317 have breakpoint locations -- e.g., stepping past a single-step
1318 breakpoint, or stepping to complete a non-continuable
1320 static struct step_over_info step_over_info
;
1322 /* Record the address of the breakpoint/instruction we're currently
1324 N.B. We record the aspace and address now, instead of say just the thread,
1325 because when we need the info later the thread may be running. */
1328 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1329 int nonsteppable_watchpoint_p
,
1332 step_over_info
.aspace
= aspace
;
1333 step_over_info
.address
= address
;
1334 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1335 step_over_info
.thread
= thread
;
1338 /* Called when we're not longer stepping over a breakpoint / an
1339 instruction, so all breakpoints are free to be (re)inserted. */
1342 clear_step_over_info (void)
1344 infrun_debug_printf ("clearing step over info");
1345 step_over_info
.aspace
= NULL
;
1346 step_over_info
.address
= 0;
1347 step_over_info
.nonsteppable_watchpoint_p
= 0;
1348 step_over_info
.thread
= -1;
1354 stepping_past_instruction_at (struct address_space
*aspace
,
1357 return (step_over_info
.aspace
!= NULL
1358 && breakpoint_address_match (aspace
, address
,
1359 step_over_info
.aspace
,
1360 step_over_info
.address
));
1366 thread_is_stepping_over_breakpoint (int thread
)
1368 return (step_over_info
.thread
!= -1
1369 && thread
== step_over_info
.thread
);
1375 stepping_past_nonsteppable_watchpoint (void)
1377 return step_over_info
.nonsteppable_watchpoint_p
;
1380 /* Returns true if step-over info is valid. */
1383 step_over_info_valid_p (void)
1385 return (step_over_info
.aspace
!= NULL
1386 || stepping_past_nonsteppable_watchpoint ());
1390 /* Displaced stepping. */
1392 /* In non-stop debugging mode, we must take special care to manage
1393 breakpoints properly; in particular, the traditional strategy for
1394 stepping a thread past a breakpoint it has hit is unsuitable.
1395 'Displaced stepping' is a tactic for stepping one thread past a
1396 breakpoint it has hit while ensuring that other threads running
1397 concurrently will hit the breakpoint as they should.
1399 The traditional way to step a thread T off a breakpoint in a
1400 multi-threaded program in all-stop mode is as follows:
1402 a0) Initially, all threads are stopped, and breakpoints are not
1404 a1) We single-step T, leaving breakpoints uninserted.
1405 a2) We insert breakpoints, and resume all threads.
1407 In non-stop debugging, however, this strategy is unsuitable: we
1408 don't want to have to stop all threads in the system in order to
1409 continue or step T past a breakpoint. Instead, we use displaced
1412 n0) Initially, T is stopped, other threads are running, and
1413 breakpoints are inserted.
1414 n1) We copy the instruction "under" the breakpoint to a separate
1415 location, outside the main code stream, making any adjustments
1416 to the instruction, register, and memory state as directed by
1418 n2) We single-step T over the instruction at its new location.
1419 n3) We adjust the resulting register and memory state as directed
1420 by T's architecture. This includes resetting T's PC to point
1421 back into the main instruction stream.
1424 This approach depends on the following gdbarch methods:
1426 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1427 indicate where to copy the instruction, and how much space must
1428 be reserved there. We use these in step n1.
1430 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1431 address, and makes any necessary adjustments to the instruction,
1432 register contents, and memory. We use this in step n1.
1434 - gdbarch_displaced_step_fixup adjusts registers and memory after
1435 we have successfully single-stepped the instruction, to yield the
1436 same effect the instruction would have had if we had executed it
1437 at its original address. We use this in step n3.
1439 The gdbarch_displaced_step_copy_insn and
1440 gdbarch_displaced_step_fixup functions must be written so that
1441 copying an instruction with gdbarch_displaced_step_copy_insn,
1442 single-stepping across the copied instruction, and then applying
1443 gdbarch_displaced_insn_fixup should have the same effects on the
1444 thread's memory and registers as stepping the instruction in place
1445 would have. Exactly which responsibilities fall to the copy and
1446 which fall to the fixup is up to the author of those functions.
1448 See the comments in gdbarch.sh for details.
1450 Note that displaced stepping and software single-step cannot
1451 currently be used in combination, although with some care I think
1452 they could be made to. Software single-step works by placing
1453 breakpoints on all possible subsequent instructions; if the
1454 displaced instruction is a PC-relative jump, those breakpoints
1455 could fall in very strange places --- on pages that aren't
1456 executable, or at addresses that are not proper instruction
1457 boundaries. (We do generally let other threads run while we wait
1458 to hit the software single-step breakpoint, and they might
1459 encounter such a corrupted instruction.) One way to work around
1460 this would be to have gdbarch_displaced_step_copy_insn fully
1461 simulate the effect of PC-relative instructions (and return NULL)
1462 on architectures that use software single-stepping.
1464 In non-stop mode, we can have independent and simultaneous step
1465 requests, so more than one thread may need to simultaneously step
1466 over a breakpoint. The current implementation assumes there is
1467 only one scratch space per process. In this case, we have to
1468 serialize access to the scratch space. If thread A wants to step
1469 over a breakpoint, but we are currently waiting for some other
1470 thread to complete a displaced step, we leave thread A stopped and
1471 place it in the displaced_step_request_queue. Whenever a displaced
1472 step finishes, we pick the next thread in the queue and start a new
1473 displaced step operation on it. See displaced_step_prepare and
1474 displaced_step_fixup for details. */
1476 /* Default destructor for displaced_step_closure. */
1478 displaced_step_closure::~displaced_step_closure () = default;
1480 /* Get the displaced stepping state of process PID. */
1482 static displaced_step_inferior_state
*
1483 get_displaced_stepping_state (inferior
*inf
)
1485 return &inf
->displaced_step_state
;
1488 /* Returns true if any inferior has a thread doing a displaced
1492 displaced_step_in_progress_any_inferior ()
1494 for (inferior
*i
: all_inferiors ())
1496 if (i
->displaced_step_state
.step_thread
!= nullptr)
1503 /* Return true if thread represented by PTID is doing a displaced
1507 displaced_step_in_progress_thread (thread_info
*thread
)
1509 gdb_assert (thread
!= NULL
);
1511 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1514 /* Return true if process PID has a thread doing a displaced step. */
1517 displaced_step_in_progress (inferior
*inf
)
1519 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1522 /* If inferior is in displaced stepping, and ADDR equals to starting address
1523 of copy area, return corresponding displaced_step_closure. Otherwise,
1526 struct displaced_step_closure
*
1527 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1529 displaced_step_inferior_state
*displaced
1530 = get_displaced_stepping_state (current_inferior ());
1532 /* If checking the mode of displaced instruction in copy area. */
1533 if (displaced
->step_thread
!= nullptr
1534 && displaced
->step_copy
== addr
)
1535 return displaced
->step_closure
.get ();
1541 infrun_inferior_exit (struct inferior
*inf
)
1543 inf
->displaced_step_state
.reset ();
1546 /* If ON, and the architecture supports it, GDB will use displaced
1547 stepping to step over breakpoints. If OFF, or if the architecture
1548 doesn't support it, GDB will instead use the traditional
1549 hold-and-step approach. If AUTO (which is the default), GDB will
1550 decide which technique to use to step over breakpoints depending on
1551 whether the target works in a non-stop way (see use_displaced_stepping). */
1553 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1556 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1557 struct cmd_list_element
*c
,
1560 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1561 fprintf_filtered (file
,
1562 _("Debugger's willingness to use displaced stepping "
1563 "to step over breakpoints is %s (currently %s).\n"),
1564 value
, target_is_non_stop_p () ? "on" : "off");
1566 fprintf_filtered (file
,
1567 _("Debugger's willingness to use displaced stepping "
1568 "to step over breakpoints is %s.\n"), value
);
1571 /* Return true if the gdbarch implements the required methods to use
1572 displaced stepping. */
1575 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1577 /* Only check for the presence of step_copy_insn. Other required methods
1578 are checked by the gdbarch validation. */
1579 return gdbarch_displaced_step_copy_insn_p (arch
);
1582 /* Return non-zero if displaced stepping can/should be used to step
1583 over breakpoints of thread TP. */
1586 use_displaced_stepping (thread_info
*tp
)
1588 /* If the user disabled it explicitly, don't use displaced stepping. */
1589 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1592 /* If "auto", only use displaced stepping if the target operates in a non-stop
1594 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1595 && !target_is_non_stop_p ())
1598 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1600 /* If the architecture doesn't implement displaced stepping, don't use
1602 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1605 /* If recording, don't use displaced stepping. */
1606 if (find_record_target () != nullptr)
1609 displaced_step_inferior_state
*displaced_state
1610 = get_displaced_stepping_state (tp
->inf
);
1612 /* If displaced stepping failed before for this inferior, don't bother trying
1614 if (displaced_state
->failed_before
)
1620 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1623 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1625 displaced
->reset ();
1628 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1629 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1631 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1633 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1635 displaced_step_dump_bytes (struct ui_file
*file
,
1636 const gdb_byte
*buf
,
1641 for (i
= 0; i
< len
; i
++)
1642 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1643 fputs_unfiltered ("\n", file
);
1646 /* Prepare to single-step, using displaced stepping.
1648 Note that we cannot use displaced stepping when we have a signal to
1649 deliver. If we have a signal to deliver and an instruction to step
1650 over, then after the step, there will be no indication from the
1651 target whether the thread entered a signal handler or ignored the
1652 signal and stepped over the instruction successfully --- both cases
1653 result in a simple SIGTRAP. In the first case we mustn't do a
1654 fixup, and in the second case we must --- but we can't tell which.
1655 Comments in the code for 'random signals' in handle_inferior_event
1656 explain how we handle this case instead.
1658 Returns 1 if preparing was successful -- this thread is going to be
1659 stepped now; 0 if displaced stepping this thread got queued; or -1
1660 if this instruction can't be displaced stepped. */
1663 displaced_step_prepare_throw (thread_info
*tp
)
1665 regcache
*regcache
= get_thread_regcache (tp
);
1666 struct gdbarch
*gdbarch
= regcache
->arch ();
1667 const address_space
*aspace
= regcache
->aspace ();
1668 CORE_ADDR original
, copy
;
1672 /* We should never reach this function if the architecture does not
1673 support displaced stepping. */
1674 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1676 /* Nor if the thread isn't meant to step over a breakpoint. */
1677 gdb_assert (tp
->control
.trap_expected
);
1679 /* Disable range stepping while executing in the scratch pad. We
1680 want a single-step even if executing the displaced instruction in
1681 the scratch buffer lands within the stepping range (e.g., a
1683 tp
->control
.may_range_step
= 0;
1685 /* We have to displaced step one thread at a time, as we only have
1686 access to a single scratch space per inferior. */
1688 displaced_step_inferior_state
*displaced
1689 = get_displaced_stepping_state (tp
->inf
);
1691 if (displaced
->step_thread
!= nullptr)
1693 /* Already waiting for a displaced step to finish. Defer this
1694 request and place in queue. */
1696 if (debug_displaced
)
1697 fprintf_unfiltered (gdb_stdlog
,
1698 "displaced: deferring step of %s\n",
1699 target_pid_to_str (tp
->ptid
).c_str ());
1701 thread_step_over_chain_enqueue (tp
);
1706 if (debug_displaced
)
1707 fprintf_unfiltered (gdb_stdlog
,
1708 "displaced: stepping %s now\n",
1709 target_pid_to_str (tp
->ptid
).c_str ());
1712 displaced_step_reset (displaced
);
1714 scoped_restore_current_thread restore_thread
;
1716 switch_to_thread (tp
);
1718 original
= regcache_read_pc (regcache
);
1720 copy
= gdbarch_displaced_step_location (gdbarch
);
1721 len
= gdbarch_max_insn_length (gdbarch
);
1723 if (breakpoint_in_range_p (aspace
, copy
, len
))
1725 /* There's a breakpoint set in the scratch pad location range
1726 (which is usually around the entry point). We'd either
1727 install it before resuming, which would overwrite/corrupt the
1728 scratch pad, or if it was already inserted, this displaced
1729 step would overwrite it. The latter is OK in the sense that
1730 we already assume that no thread is going to execute the code
1731 in the scratch pad range (after initial startup) anyway, but
1732 the former is unacceptable. Simply punt and fallback to
1733 stepping over this breakpoint in-line. */
1734 if (debug_displaced
)
1736 fprintf_unfiltered (gdb_stdlog
,
1737 "displaced: breakpoint set in scratch pad. "
1738 "Stepping over breakpoint in-line instead.\n");
1744 /* Save the original contents of the copy area. */
1745 displaced
->step_saved_copy
.resize (len
);
1746 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1748 throw_error (MEMORY_ERROR
,
1749 _("Error accessing memory address %s (%s) for "
1750 "displaced-stepping scratch space."),
1751 paddress (gdbarch
, copy
), safe_strerror (status
));
1752 if (debug_displaced
)
1754 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1755 paddress (gdbarch
, copy
));
1756 displaced_step_dump_bytes (gdb_stdlog
,
1757 displaced
->step_saved_copy
.data (),
1761 displaced
->step_closure
1762 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1763 if (displaced
->step_closure
== NULL
)
1765 /* The architecture doesn't know how or want to displaced step
1766 this instruction or instruction sequence. Fallback to
1767 stepping over the breakpoint in-line. */
1771 /* Save the information we need to fix things up if the step
1773 displaced
->step_thread
= tp
;
1774 displaced
->step_gdbarch
= gdbarch
;
1775 displaced
->step_original
= original
;
1776 displaced
->step_copy
= copy
;
1779 displaced_step_reset_cleanup
cleanup (displaced
);
1781 /* Resume execution at the copy. */
1782 regcache_write_pc (regcache
, copy
);
1787 if (debug_displaced
)
1788 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1789 paddress (gdbarch
, copy
));
1794 /* Wrapper for displaced_step_prepare_throw that disabled further
1795 attempts at displaced stepping if we get a memory error. */
1798 displaced_step_prepare (thread_info
*thread
)
1804 prepared
= displaced_step_prepare_throw (thread
);
1806 catch (const gdb_exception_error
&ex
)
1808 struct displaced_step_inferior_state
*displaced_state
;
1810 if (ex
.error
!= MEMORY_ERROR
1811 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1814 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1817 /* Be verbose if "set displaced-stepping" is "on", silent if
1819 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1821 warning (_("disabling displaced stepping: %s"),
1825 /* Disable further displaced stepping attempts. */
1827 = get_displaced_stepping_state (thread
->inf
);
1828 displaced_state
->failed_before
= 1;
1835 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1836 const gdb_byte
*myaddr
, int len
)
1838 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1840 inferior_ptid
= ptid
;
1841 write_memory (memaddr
, myaddr
, len
);
1844 /* Restore the contents of the copy area for thread PTID. */
1847 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1850 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1852 write_memory_ptid (ptid
, displaced
->step_copy
,
1853 displaced
->step_saved_copy
.data (), len
);
1854 if (debug_displaced
)
1855 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1856 target_pid_to_str (ptid
).c_str (),
1857 paddress (displaced
->step_gdbarch
,
1858 displaced
->step_copy
));
1861 /* If we displaced stepped an instruction successfully, adjust
1862 registers and memory to yield the same effect the instruction would
1863 have had if we had executed it at its original address, and return
1864 1. If the instruction didn't complete, relocate the PC and return
1865 -1. If the thread wasn't displaced stepping, return 0. */
1868 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1870 struct displaced_step_inferior_state
*displaced
1871 = get_displaced_stepping_state (event_thread
->inf
);
1874 /* Was this event for the thread we displaced? */
1875 if (displaced
->step_thread
!= event_thread
)
1878 /* Fixup may need to read memory/registers. Switch to the thread
1879 that we're fixing up. Also, target_stopped_by_watchpoint checks
1880 the current thread, and displaced_step_restore performs ptid-dependent
1881 memory accesses using current_inferior() and current_top_target(). */
1882 switch_to_thread (event_thread
);
1884 displaced_step_reset_cleanup
cleanup (displaced
);
1886 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1888 /* Did the instruction complete successfully? */
1889 if (signal
== GDB_SIGNAL_TRAP
1890 && !(target_stopped_by_watchpoint ()
1891 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1892 || target_have_steppable_watchpoint
)))
1894 /* Fix up the resulting state. */
1895 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1896 displaced
->step_closure
.get (),
1897 displaced
->step_original
,
1898 displaced
->step_copy
,
1899 get_thread_regcache (displaced
->step_thread
));
1904 /* Since the instruction didn't complete, all we can do is
1906 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1907 CORE_ADDR pc
= regcache_read_pc (regcache
);
1909 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1910 regcache_write_pc (regcache
, pc
);
1917 /* Data to be passed around while handling an event. This data is
1918 discarded between events. */
1919 struct execution_control_state
1921 process_stratum_target
*target
;
1923 /* The thread that got the event, if this was a thread event; NULL
1925 struct thread_info
*event_thread
;
1927 struct target_waitstatus ws
;
1928 int stop_func_filled_in
;
1929 CORE_ADDR stop_func_start
;
1930 CORE_ADDR stop_func_end
;
1931 const char *stop_func_name
;
1934 /* True if the event thread hit the single-step breakpoint of
1935 another thread. Thus the event doesn't cause a stop, the thread
1936 needs to be single-stepped past the single-step breakpoint before
1937 we can switch back to the original stepping thread. */
1938 int hit_singlestep_breakpoint
;
1941 /* Clear ECS and set it to point at TP. */
1944 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1946 memset (ecs
, 0, sizeof (*ecs
));
1947 ecs
->event_thread
= tp
;
1948 ecs
->ptid
= tp
->ptid
;
1951 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1952 static void prepare_to_wait (struct execution_control_state
*ecs
);
1953 static int keep_going_stepped_thread (struct thread_info
*tp
);
1954 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1956 /* Are there any pending step-over requests? If so, run all we can
1957 now and return true. Otherwise, return false. */
1960 start_step_over (void)
1962 struct thread_info
*tp
, *next
;
1964 /* Don't start a new step-over if we already have an in-line
1965 step-over operation ongoing. */
1966 if (step_over_info_valid_p ())
1969 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1971 struct execution_control_state ecss
;
1972 struct execution_control_state
*ecs
= &ecss
;
1973 step_over_what step_what
;
1974 int must_be_in_line
;
1976 gdb_assert (!tp
->stop_requested
);
1978 next
= thread_step_over_chain_next (tp
);
1980 /* If this inferior already has a displaced step in process,
1981 don't start a new one. */
1982 if (displaced_step_in_progress (tp
->inf
))
1985 step_what
= thread_still_needs_step_over (tp
);
1986 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1987 || ((step_what
& STEP_OVER_BREAKPOINT
)
1988 && !use_displaced_stepping (tp
)));
1990 /* We currently stop all threads of all processes to step-over
1991 in-line. If we need to start a new in-line step-over, let
1992 any pending displaced steps finish first. */
1993 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1996 thread_step_over_chain_remove (tp
);
1998 if (step_over_queue_head
== NULL
)
1999 infrun_debug_printf ("step-over queue now empty");
2001 if (tp
->control
.trap_expected
2005 internal_error (__FILE__
, __LINE__
,
2006 "[%s] has inconsistent state: "
2007 "trap_expected=%d, resumed=%d, executing=%d\n",
2008 target_pid_to_str (tp
->ptid
).c_str (),
2009 tp
->control
.trap_expected
,
2014 infrun_debug_printf ("resuming [%s] for step-over",
2015 target_pid_to_str (tp
->ptid
).c_str ());
2017 /* keep_going_pass_signal skips the step-over if the breakpoint
2018 is no longer inserted. In all-stop, we want to keep looking
2019 for a thread that needs a step-over instead of resuming TP,
2020 because we wouldn't be able to resume anything else until the
2021 target stops again. In non-stop, the resume always resumes
2022 only TP, so it's OK to let the thread resume freely. */
2023 if (!target_is_non_stop_p () && !step_what
)
2026 switch_to_thread (tp
);
2027 reset_ecs (ecs
, tp
);
2028 keep_going_pass_signal (ecs
);
2030 if (!ecs
->wait_some_more
)
2031 error (_("Command aborted."));
2033 gdb_assert (tp
->resumed
);
2035 /* If we started a new in-line step-over, we're done. */
2036 if (step_over_info_valid_p ())
2038 gdb_assert (tp
->control
.trap_expected
);
2042 if (!target_is_non_stop_p ())
2044 /* On all-stop, shouldn't have resumed unless we needed a
2046 gdb_assert (tp
->control
.trap_expected
2047 || tp
->step_after_step_resume_breakpoint
);
2049 /* With remote targets (at least), in all-stop, we can't
2050 issue any further remote commands until the program stops
2055 /* Either the thread no longer needed a step-over, or a new
2056 displaced stepping sequence started. Even in the latter
2057 case, continue looking. Maybe we can also start another
2058 displaced step on a thread of other process. */
2064 /* Update global variables holding ptids to hold NEW_PTID if they were
2065 holding OLD_PTID. */
2067 infrun_thread_ptid_changed (process_stratum_target
*target
,
2068 ptid_t old_ptid
, ptid_t new_ptid
)
2070 if (inferior_ptid
== old_ptid
2071 && current_inferior ()->process_target () == target
)
2072 inferior_ptid
= new_ptid
;
2077 static const char schedlock_off
[] = "off";
2078 static const char schedlock_on
[] = "on";
2079 static const char schedlock_step
[] = "step";
2080 static const char schedlock_replay
[] = "replay";
2081 static const char *const scheduler_enums
[] = {
2088 static const char *scheduler_mode
= schedlock_replay
;
2090 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2091 struct cmd_list_element
*c
, const char *value
)
2093 fprintf_filtered (file
,
2094 _("Mode for locking scheduler "
2095 "during execution is \"%s\".\n"),
2100 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2102 if (!target_can_lock_scheduler
)
2104 scheduler_mode
= schedlock_off
;
2105 error (_("Target '%s' cannot support this command."), target_shortname
);
2109 /* True if execution commands resume all threads of all processes by
2110 default; otherwise, resume only threads of the current inferior
2112 bool sched_multi
= false;
2114 /* Try to setup for software single stepping over the specified location.
2115 Return 1 if target_resume() should use hardware single step.
2117 GDBARCH the current gdbarch.
2118 PC the location to step over. */
2121 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2125 if (execution_direction
== EXEC_FORWARD
2126 && gdbarch_software_single_step_p (gdbarch
))
2127 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2135 user_visible_resume_ptid (int step
)
2141 /* With non-stop mode on, threads are always handled
2143 resume_ptid
= inferior_ptid
;
2145 else if ((scheduler_mode
== schedlock_on
)
2146 || (scheduler_mode
== schedlock_step
&& step
))
2148 /* User-settable 'scheduler' mode requires solo thread
2150 resume_ptid
= inferior_ptid
;
2152 else if ((scheduler_mode
== schedlock_replay
)
2153 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2155 /* User-settable 'scheduler' mode requires solo thread resume in replay
2157 resume_ptid
= inferior_ptid
;
2159 else if (!sched_multi
&& target_supports_multi_process ())
2161 /* Resume all threads of the current process (and none of other
2163 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2167 /* Resume all threads of all processes. */
2168 resume_ptid
= RESUME_ALL
;
2176 process_stratum_target
*
2177 user_visible_resume_target (ptid_t resume_ptid
)
2179 return (resume_ptid
== minus_one_ptid
&& sched_multi
2181 : current_inferior ()->process_target ());
2184 /* Return a ptid representing the set of threads that we will resume,
2185 in the perspective of the target, assuming run control handling
2186 does not require leaving some threads stopped (e.g., stepping past
2187 breakpoint). USER_STEP indicates whether we're about to start the
2188 target for a stepping command. */
2191 internal_resume_ptid (int user_step
)
2193 /* In non-stop, we always control threads individually. Note that
2194 the target may always work in non-stop mode even with "set
2195 non-stop off", in which case user_visible_resume_ptid could
2196 return a wildcard ptid. */
2197 if (target_is_non_stop_p ())
2198 return inferior_ptid
;
2200 return user_visible_resume_ptid (user_step
);
2203 /* Wrapper for target_resume, that handles infrun-specific
2207 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2209 struct thread_info
*tp
= inferior_thread ();
2211 gdb_assert (!tp
->stop_requested
);
2213 /* Install inferior's terminal modes. */
2214 target_terminal::inferior ();
2216 /* Avoid confusing the next resume, if the next stop/resume
2217 happens to apply to another thread. */
2218 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2220 /* Advise target which signals may be handled silently.
2222 If we have removed breakpoints because we are stepping over one
2223 in-line (in any thread), we need to receive all signals to avoid
2224 accidentally skipping a breakpoint during execution of a signal
2227 Likewise if we're displaced stepping, otherwise a trap for a
2228 breakpoint in a signal handler might be confused with the
2229 displaced step finishing. We don't make the displaced_step_fixup
2230 step distinguish the cases instead, because:
2232 - a backtrace while stopped in the signal handler would show the
2233 scratch pad as frame older than the signal handler, instead of
2234 the real mainline code.
2236 - when the thread is later resumed, the signal handler would
2237 return to the scratch pad area, which would no longer be
2239 if (step_over_info_valid_p ()
2240 || displaced_step_in_progress (tp
->inf
))
2241 target_pass_signals ({});
2243 target_pass_signals (signal_pass
);
2245 target_resume (resume_ptid
, step
, sig
);
2247 target_commit_resume ();
2249 if (target_can_async_p ())
2253 /* Resume the inferior. SIG is the signal to give the inferior
2254 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2255 call 'resume', which handles exceptions. */
2258 resume_1 (enum gdb_signal sig
)
2260 struct regcache
*regcache
= get_current_regcache ();
2261 struct gdbarch
*gdbarch
= regcache
->arch ();
2262 struct thread_info
*tp
= inferior_thread ();
2263 const address_space
*aspace
= regcache
->aspace ();
2265 /* This represents the user's step vs continue request. When
2266 deciding whether "set scheduler-locking step" applies, it's the
2267 user's intention that counts. */
2268 const int user_step
= tp
->control
.stepping_command
;
2269 /* This represents what we'll actually request the target to do.
2270 This can decay from a step to a continue, if e.g., we need to
2271 implement single-stepping with breakpoints (software
2275 gdb_assert (!tp
->stop_requested
);
2276 gdb_assert (!thread_is_in_step_over_chain (tp
));
2278 if (tp
->suspend
.waitstatus_pending_p
)
2281 ("thread %s has pending wait "
2282 "status %s (currently_stepping=%d).",
2283 target_pid_to_str (tp
->ptid
).c_str (),
2284 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2285 currently_stepping (tp
));
2287 tp
->inf
->process_target ()->threads_executing
= true;
2290 /* FIXME: What should we do if we are supposed to resume this
2291 thread with a signal? Maybe we should maintain a queue of
2292 pending signals to deliver. */
2293 if (sig
!= GDB_SIGNAL_0
)
2295 warning (_("Couldn't deliver signal %s to %s."),
2296 gdb_signal_to_name (sig
),
2297 target_pid_to_str (tp
->ptid
).c_str ());
2300 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2302 if (target_can_async_p ())
2305 /* Tell the event loop we have an event to process. */
2306 mark_async_event_handler (infrun_async_inferior_event_token
);
2311 tp
->stepped_breakpoint
= 0;
2313 /* Depends on stepped_breakpoint. */
2314 step
= currently_stepping (tp
);
2316 if (current_inferior ()->waiting_for_vfork_done
)
2318 /* Don't try to single-step a vfork parent that is waiting for
2319 the child to get out of the shared memory region (by exec'ing
2320 or exiting). This is particularly important on software
2321 single-step archs, as the child process would trip on the
2322 software single step breakpoint inserted for the parent
2323 process. Since the parent will not actually execute any
2324 instruction until the child is out of the shared region (such
2325 are vfork's semantics), it is safe to simply continue it.
2326 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2327 the parent, and tell it to `keep_going', which automatically
2328 re-sets it stepping. */
2329 infrun_debug_printf ("resume : clear step");
2333 CORE_ADDR pc
= regcache_read_pc (regcache
);
2335 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2336 "current thread [%s] at %s",
2337 step
, gdb_signal_to_symbol_string (sig
),
2338 tp
->control
.trap_expected
,
2339 target_pid_to_str (inferior_ptid
).c_str (),
2340 paddress (gdbarch
, pc
));
2342 /* Normally, by the time we reach `resume', the breakpoints are either
2343 removed or inserted, as appropriate. The exception is if we're sitting
2344 at a permanent breakpoint; we need to step over it, but permanent
2345 breakpoints can't be removed. So we have to test for it here. */
2346 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2348 if (sig
!= GDB_SIGNAL_0
)
2350 /* We have a signal to pass to the inferior. The resume
2351 may, or may not take us to the signal handler. If this
2352 is a step, we'll need to stop in the signal handler, if
2353 there's one, (if the target supports stepping into
2354 handlers), or in the next mainline instruction, if
2355 there's no handler. If this is a continue, we need to be
2356 sure to run the handler with all breakpoints inserted.
2357 In all cases, set a breakpoint at the current address
2358 (where the handler returns to), and once that breakpoint
2359 is hit, resume skipping the permanent breakpoint. If
2360 that breakpoint isn't hit, then we've stepped into the
2361 signal handler (or hit some other event). We'll delete
2362 the step-resume breakpoint then. */
2364 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2365 "deliver signal first");
2367 clear_step_over_info ();
2368 tp
->control
.trap_expected
= 0;
2370 if (tp
->control
.step_resume_breakpoint
== NULL
)
2372 /* Set a "high-priority" step-resume, as we don't want
2373 user breakpoints at PC to trigger (again) when this
2375 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2376 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2378 tp
->step_after_step_resume_breakpoint
= step
;
2381 insert_breakpoints ();
2385 /* There's no signal to pass, we can go ahead and skip the
2386 permanent breakpoint manually. */
2387 infrun_debug_printf ("skipping permanent breakpoint");
2388 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2389 /* Update pc to reflect the new address from which we will
2390 execute instructions. */
2391 pc
= regcache_read_pc (regcache
);
2395 /* We've already advanced the PC, so the stepping part
2396 is done. Now we need to arrange for a trap to be
2397 reported to handle_inferior_event. Set a breakpoint
2398 at the current PC, and run to it. Don't update
2399 prev_pc, because if we end in
2400 switch_back_to_stepped_thread, we want the "expected
2401 thread advanced also" branch to be taken. IOW, we
2402 don't want this thread to step further from PC
2404 gdb_assert (!step_over_info_valid_p ());
2405 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2406 insert_breakpoints ();
2408 resume_ptid
= internal_resume_ptid (user_step
);
2409 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2416 /* If we have a breakpoint to step over, make sure to do a single
2417 step only. Same if we have software watchpoints. */
2418 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2419 tp
->control
.may_range_step
= 0;
2421 /* If displaced stepping is enabled, step over breakpoints by executing a
2422 copy of the instruction at a different address.
2424 We can't use displaced stepping when we have a signal to deliver;
2425 the comments for displaced_step_prepare explain why. The
2426 comments in the handle_inferior event for dealing with 'random
2427 signals' explain what we do instead.
2429 We can't use displaced stepping when we are waiting for vfork_done
2430 event, displaced stepping breaks the vfork child similarly as single
2431 step software breakpoint. */
2432 if (tp
->control
.trap_expected
2433 && use_displaced_stepping (tp
)
2434 && !step_over_info_valid_p ()
2435 && sig
== GDB_SIGNAL_0
2436 && !current_inferior ()->waiting_for_vfork_done
)
2438 int prepared
= displaced_step_prepare (tp
);
2442 infrun_debug_printf ("Got placed in step-over queue");
2444 tp
->control
.trap_expected
= 0;
2447 else if (prepared
< 0)
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 (prepared
> 0)
2463 struct displaced_step_inferior_state
*displaced
;
2465 /* Update pc to reflect the new address from which we will
2466 execute instructions due to displaced stepping. */
2467 pc
= regcache_read_pc (get_thread_regcache (tp
));
2469 displaced
= get_displaced_stepping_state (tp
->inf
);
2470 step
= gdbarch_displaced_step_hw_singlestep
2471 (gdbarch
, displaced
->step_closure
.get ());
2475 /* Do we need to do it the hard way, w/temp breakpoints? */
2477 step
= maybe_software_singlestep (gdbarch
, pc
);
2479 /* Currently, our software single-step implementation leads to different
2480 results than hardware single-stepping in one situation: when stepping
2481 into delivering a signal which has an associated signal handler,
2482 hardware single-step will stop at the first instruction of the handler,
2483 while software single-step will simply skip execution of the handler.
2485 For now, this difference in behavior is accepted since there is no
2486 easy way to actually implement single-stepping into a signal handler
2487 without kernel support.
2489 However, there is one scenario where this difference leads to follow-on
2490 problems: if we're stepping off a breakpoint by removing all breakpoints
2491 and then single-stepping. In this case, the software single-step
2492 behavior means that even if there is a *breakpoint* in the signal
2493 handler, GDB still would not stop.
2495 Fortunately, we can at least fix this particular issue. We detect
2496 here the case where we are about to deliver a signal while software
2497 single-stepping with breakpoints removed. In this situation, we
2498 revert the decisions to remove all breakpoints and insert single-
2499 step breakpoints, and instead we install a step-resume breakpoint
2500 at the current address, deliver the signal without stepping, and
2501 once we arrive back at the step-resume breakpoint, actually step
2502 over the breakpoint we originally wanted to step over. */
2503 if (thread_has_single_step_breakpoints_set (tp
)
2504 && sig
!= GDB_SIGNAL_0
2505 && step_over_info_valid_p ())
2507 /* If we have nested signals or a pending signal is delivered
2508 immediately after a handler returns, might already have
2509 a step-resume breakpoint set on the earlier handler. We cannot
2510 set another step-resume breakpoint; just continue on until the
2511 original breakpoint is hit. */
2512 if (tp
->control
.step_resume_breakpoint
== NULL
)
2514 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2515 tp
->step_after_step_resume_breakpoint
= 1;
2518 delete_single_step_breakpoints (tp
);
2520 clear_step_over_info ();
2521 tp
->control
.trap_expected
= 0;
2523 insert_breakpoints ();
2526 /* If STEP is set, it's a request to use hardware stepping
2527 facilities. But in that case, we should never
2528 use singlestep breakpoint. */
2529 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2531 /* Decide the set of threads to ask the target to resume. */
2532 if (tp
->control
.trap_expected
)
2534 /* We're allowing a thread to run past a breakpoint it has
2535 hit, either by single-stepping the thread with the breakpoint
2536 removed, or by displaced stepping, with the breakpoint inserted.
2537 In the former case, we need to single-step only this thread,
2538 and keep others stopped, as they can miss this breakpoint if
2539 allowed to run. That's not really a problem for displaced
2540 stepping, but, we still keep other threads stopped, in case
2541 another thread is also stopped for a breakpoint waiting for
2542 its turn in the displaced stepping queue. */
2543 resume_ptid
= inferior_ptid
;
2546 resume_ptid
= internal_resume_ptid (user_step
);
2548 if (execution_direction
!= EXEC_REVERSE
2549 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2551 /* There are two cases where we currently need to step a
2552 breakpoint instruction when we have a signal to deliver:
2554 - See handle_signal_stop where we handle random signals that
2555 could take out us out of the stepping range. Normally, in
2556 that case we end up continuing (instead of stepping) over the
2557 signal handler with a breakpoint at PC, but there are cases
2558 where we should _always_ single-step, even if we have a
2559 step-resume breakpoint, like when a software watchpoint is
2560 set. Assuming single-stepping and delivering a signal at the
2561 same time would takes us to the signal handler, then we could
2562 have removed the breakpoint at PC to step over it. However,
2563 some hardware step targets (like e.g., Mac OS) can't step
2564 into signal handlers, and for those, we need to leave the
2565 breakpoint at PC inserted, as otherwise if the handler
2566 recurses and executes PC again, it'll miss the breakpoint.
2567 So we leave the breakpoint inserted anyway, but we need to
2568 record that we tried to step a breakpoint instruction, so
2569 that adjust_pc_after_break doesn't end up confused.
2571 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2572 in one thread after another thread that was stepping had been
2573 momentarily paused for a step-over. When we re-resume the
2574 stepping thread, it may be resumed from that address with a
2575 breakpoint that hasn't trapped yet. Seen with
2576 gdb.threads/non-stop-fair-events.exp, on targets that don't
2577 do displaced stepping. */
2579 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2580 target_pid_to_str (tp
->ptid
).c_str ());
2582 tp
->stepped_breakpoint
= 1;
2584 /* Most targets can step a breakpoint instruction, thus
2585 executing it normally. But if this one cannot, just
2586 continue and we will hit it anyway. */
2587 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2592 && tp
->control
.trap_expected
2593 && use_displaced_stepping (tp
)
2594 && !step_over_info_valid_p ())
2596 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2597 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2598 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2601 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2602 paddress (resume_gdbarch
, actual_pc
));
2603 read_memory (actual_pc
, buf
, sizeof (buf
));
2604 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2607 if (tp
->control
.may_range_step
)
2609 /* If we're resuming a thread with the PC out of the step
2610 range, then we're doing some nested/finer run control
2611 operation, like stepping the thread out of the dynamic
2612 linker or the displaced stepping scratch pad. We
2613 shouldn't have allowed a range step then. */
2614 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2617 do_target_resume (resume_ptid
, step
, sig
);
2621 /* Resume the inferior. SIG is the signal to give the inferior
2622 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2623 rolls back state on error. */
2626 resume (gdb_signal sig
)
2632 catch (const gdb_exception
&ex
)
2634 /* If resuming is being aborted for any reason, delete any
2635 single-step breakpoint resume_1 may have created, to avoid
2636 confusing the following resumption, and to avoid leaving
2637 single-step breakpoints perturbing other threads, in case
2638 we're running in non-stop mode. */
2639 if (inferior_ptid
!= null_ptid
)
2640 delete_single_step_breakpoints (inferior_thread ());
2650 /* Counter that tracks number of user visible stops. This can be used
2651 to tell whether a command has proceeded the inferior past the
2652 current location. This allows e.g., inferior function calls in
2653 breakpoint commands to not interrupt the command list. When the
2654 call finishes successfully, the inferior is standing at the same
2655 breakpoint as if nothing happened (and so we don't call
2657 static ULONGEST current_stop_id
;
2664 return current_stop_id
;
2667 /* Called when we report a user visible stop. */
2675 /* Clear out all variables saying what to do when inferior is continued.
2676 First do this, then set the ones you want, then call `proceed'. */
2679 clear_proceed_status_thread (struct thread_info
*tp
)
2681 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2683 /* If we're starting a new sequence, then the previous finished
2684 single-step is no longer relevant. */
2685 if (tp
->suspend
.waitstatus_pending_p
)
2687 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2689 infrun_debug_printf ("pending event of %s was a finished step. "
2691 target_pid_to_str (tp
->ptid
).c_str ());
2693 tp
->suspend
.waitstatus_pending_p
= 0;
2694 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2699 ("thread %s has pending wait status %s (currently_stepping=%d).",
2700 target_pid_to_str (tp
->ptid
).c_str (),
2701 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2702 currently_stepping (tp
));
2706 /* If this signal should not be seen by program, give it zero.
2707 Used for debugging signals. */
2708 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2709 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2711 delete tp
->thread_fsm
;
2712 tp
->thread_fsm
= NULL
;
2714 tp
->control
.trap_expected
= 0;
2715 tp
->control
.step_range_start
= 0;
2716 tp
->control
.step_range_end
= 0;
2717 tp
->control
.may_range_step
= 0;
2718 tp
->control
.step_frame_id
= null_frame_id
;
2719 tp
->control
.step_stack_frame_id
= null_frame_id
;
2720 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2721 tp
->control
.step_start_function
= NULL
;
2722 tp
->stop_requested
= 0;
2724 tp
->control
.stop_step
= 0;
2726 tp
->control
.proceed_to_finish
= 0;
2728 tp
->control
.stepping_command
= 0;
2730 /* Discard any remaining commands or status from previous stop. */
2731 bpstat_clear (&tp
->control
.stop_bpstat
);
2735 clear_proceed_status (int step
)
2737 /* With scheduler-locking replay, stop replaying other threads if we're
2738 not replaying the user-visible resume ptid.
2740 This is a convenience feature to not require the user to explicitly
2741 stop replaying the other threads. We're assuming that the user's
2742 intent is to resume tracing the recorded process. */
2743 if (!non_stop
&& scheduler_mode
== schedlock_replay
2744 && target_record_is_replaying (minus_one_ptid
)
2745 && !target_record_will_replay (user_visible_resume_ptid (step
),
2746 execution_direction
))
2747 target_record_stop_replaying ();
2749 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2751 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2752 process_stratum_target
*resume_target
2753 = user_visible_resume_target (resume_ptid
);
2755 /* In all-stop mode, delete the per-thread status of all threads
2756 we're about to resume, implicitly and explicitly. */
2757 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2758 clear_proceed_status_thread (tp
);
2761 if (inferior_ptid
!= null_ptid
)
2763 struct inferior
*inferior
;
2767 /* If in non-stop mode, only delete the per-thread status of
2768 the current thread. */
2769 clear_proceed_status_thread (inferior_thread ());
2772 inferior
= current_inferior ();
2773 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2776 gdb::observers::about_to_proceed
.notify ();
2779 /* Returns true if TP is still stopped at a breakpoint that needs
2780 stepping-over in order to make progress. If the breakpoint is gone
2781 meanwhile, we can skip the whole step-over dance. */
2784 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2786 if (tp
->stepping_over_breakpoint
)
2788 struct regcache
*regcache
= get_thread_regcache (tp
);
2790 if (breakpoint_here_p (regcache
->aspace (),
2791 regcache_read_pc (regcache
))
2792 == ordinary_breakpoint_here
)
2795 tp
->stepping_over_breakpoint
= 0;
2801 /* Check whether thread TP still needs to start a step-over in order
2802 to make progress when resumed. Returns an bitwise or of enum
2803 step_over_what bits, indicating what needs to be stepped over. */
2805 static step_over_what
2806 thread_still_needs_step_over (struct thread_info
*tp
)
2808 step_over_what what
= 0;
2810 if (thread_still_needs_step_over_bp (tp
))
2811 what
|= STEP_OVER_BREAKPOINT
;
2813 if (tp
->stepping_over_watchpoint
2814 && !target_have_steppable_watchpoint
)
2815 what
|= STEP_OVER_WATCHPOINT
;
2820 /* Returns true if scheduler locking applies. STEP indicates whether
2821 we're about to do a step/next-like command to a thread. */
2824 schedlock_applies (struct thread_info
*tp
)
2826 return (scheduler_mode
== schedlock_on
2827 || (scheduler_mode
== schedlock_step
2828 && tp
->control
.stepping_command
)
2829 || (scheduler_mode
== schedlock_replay
2830 && target_record_will_replay (minus_one_ptid
,
2831 execution_direction
)));
2834 /* Calls target_commit_resume on all targets. */
2837 commit_resume_all_targets ()
2839 scoped_restore_current_thread restore_thread
;
2841 /* Map between process_target and a representative inferior. This
2842 is to avoid committing a resume in the same target more than
2843 once. Resumptions must be idempotent, so this is an
2845 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2847 for (inferior
*inf
: all_non_exited_inferiors ())
2848 if (inf
->has_execution ())
2849 conn_inf
[inf
->process_target ()] = inf
;
2851 for (const auto &ci
: conn_inf
)
2853 inferior
*inf
= ci
.second
;
2854 switch_to_inferior_no_thread (inf
);
2855 target_commit_resume ();
2859 /* Check that all the targets we're about to resume are in non-stop
2860 mode. Ideally, we'd only care whether all targets support
2861 target-async, but we're not there yet. E.g., stop_all_threads
2862 doesn't know how to handle all-stop targets. Also, the remote
2863 protocol in all-stop mode is synchronous, irrespective of
2864 target-async, which means that things like a breakpoint re-set
2865 triggered by one target would try to read memory from all targets
2869 check_multi_target_resumption (process_stratum_target
*resume_target
)
2871 if (!non_stop
&& resume_target
== nullptr)
2873 scoped_restore_current_thread restore_thread
;
2875 /* This is used to track whether we're resuming more than one
2877 process_stratum_target
*first_connection
= nullptr;
2879 /* The first inferior we see with a target that does not work in
2880 always-non-stop mode. */
2881 inferior
*first_not_non_stop
= nullptr;
2883 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2885 switch_to_inferior_no_thread (inf
);
2887 if (!target_has_execution
)
2890 process_stratum_target
*proc_target
2891 = current_inferior ()->process_target();
2893 if (!target_is_non_stop_p ())
2894 first_not_non_stop
= inf
;
2896 if (first_connection
== nullptr)
2897 first_connection
= proc_target
;
2898 else if (first_connection
!= proc_target
2899 && first_not_non_stop
!= nullptr)
2901 switch_to_inferior_no_thread (first_not_non_stop
);
2903 proc_target
= current_inferior ()->process_target();
2905 error (_("Connection %d (%s) does not support "
2906 "multi-target resumption."),
2907 proc_target
->connection_number
,
2908 make_target_connection_string (proc_target
).c_str ());
2914 /* Basic routine for continuing the program in various fashions.
2916 ADDR is the address to resume at, or -1 for resume where stopped.
2917 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2918 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2920 You should call clear_proceed_status before calling proceed. */
2923 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2925 struct regcache
*regcache
;
2926 struct gdbarch
*gdbarch
;
2928 struct execution_control_state ecss
;
2929 struct execution_control_state
*ecs
= &ecss
;
2932 /* If we're stopped at a fork/vfork, follow the branch set by the
2933 "set follow-fork-mode" command; otherwise, we'll just proceed
2934 resuming the current thread. */
2935 if (!follow_fork ())
2937 /* The target for some reason decided not to resume. */
2939 if (target_can_async_p ())
2940 inferior_event_handler (INF_EXEC_COMPLETE
);
2944 /* We'll update this if & when we switch to a new thread. */
2945 previous_inferior_ptid
= inferior_ptid
;
2947 regcache
= get_current_regcache ();
2948 gdbarch
= regcache
->arch ();
2949 const address_space
*aspace
= regcache
->aspace ();
2951 pc
= regcache_read_pc_protected (regcache
);
2953 thread_info
*cur_thr
= inferior_thread ();
2955 /* Fill in with reasonable starting values. */
2956 init_thread_stepping_state (cur_thr
);
2958 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2961 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2962 process_stratum_target
*resume_target
2963 = user_visible_resume_target (resume_ptid
);
2965 check_multi_target_resumption (resume_target
);
2967 if (addr
== (CORE_ADDR
) -1)
2969 if (pc
== cur_thr
->suspend
.stop_pc
2970 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2971 && execution_direction
!= EXEC_REVERSE
)
2972 /* There is a breakpoint at the address we will resume at,
2973 step one instruction before inserting breakpoints so that
2974 we do not stop right away (and report a second hit at this
2977 Note, we don't do this in reverse, because we won't
2978 actually be executing the breakpoint insn anyway.
2979 We'll be (un-)executing the previous instruction. */
2980 cur_thr
->stepping_over_breakpoint
= 1;
2981 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2982 && gdbarch_single_step_through_delay (gdbarch
,
2983 get_current_frame ()))
2984 /* We stepped onto an instruction that needs to be stepped
2985 again before re-inserting the breakpoint, do so. */
2986 cur_thr
->stepping_over_breakpoint
= 1;
2990 regcache_write_pc (regcache
, addr
);
2993 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2994 cur_thr
->suspend
.stop_signal
= siggnal
;
2996 /* If an exception is thrown from this point on, make sure to
2997 propagate GDB's knowledge of the executing state to the
2998 frontend/user running state. */
2999 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3001 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3002 threads (e.g., we might need to set threads stepping over
3003 breakpoints first), from the user/frontend's point of view, all
3004 threads in RESUME_PTID are now running. Unless we're calling an
3005 inferior function, as in that case we pretend the inferior
3006 doesn't run at all. */
3007 if (!cur_thr
->control
.in_infcall
)
3008 set_running (resume_target
, resume_ptid
, true);
3010 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3011 gdb_signal_to_symbol_string (siggnal
));
3013 annotate_starting ();
3015 /* Make sure that output from GDB appears before output from the
3017 gdb_flush (gdb_stdout
);
3019 /* Since we've marked the inferior running, give it the terminal. A
3020 QUIT/Ctrl-C from here on is forwarded to the target (which can
3021 still detect attempts to unblock a stuck connection with repeated
3022 Ctrl-C from within target_pass_ctrlc). */
3023 target_terminal::inferior ();
3025 /* In a multi-threaded task we may select another thread and
3026 then continue or step.
3028 But if a thread that we're resuming had stopped at a breakpoint,
3029 it will immediately cause another breakpoint stop without any
3030 execution (i.e. it will report a breakpoint hit incorrectly). So
3031 we must step over it first.
3033 Look for threads other than the current (TP) that reported a
3034 breakpoint hit and haven't been resumed yet since. */
3036 /* If scheduler locking applies, we can avoid iterating over all
3038 if (!non_stop
&& !schedlock_applies (cur_thr
))
3040 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3043 switch_to_thread_no_regs (tp
);
3045 /* Ignore the current thread here. It's handled
3050 if (!thread_still_needs_step_over (tp
))
3053 gdb_assert (!thread_is_in_step_over_chain (tp
));
3055 infrun_debug_printf ("need to step-over [%s] first",
3056 target_pid_to_str (tp
->ptid
).c_str ());
3058 thread_step_over_chain_enqueue (tp
);
3061 switch_to_thread (cur_thr
);
3064 /* Enqueue the current thread last, so that we move all other
3065 threads over their breakpoints first. */
3066 if (cur_thr
->stepping_over_breakpoint
)
3067 thread_step_over_chain_enqueue (cur_thr
);
3069 /* If the thread isn't started, we'll still need to set its prev_pc,
3070 so that switch_back_to_stepped_thread knows the thread hasn't
3071 advanced. Must do this before resuming any thread, as in
3072 all-stop/remote, once we resume we can't send any other packet
3073 until the target stops again. */
3074 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3077 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3079 started
= start_step_over ();
3081 if (step_over_info_valid_p ())
3083 /* Either this thread started a new in-line step over, or some
3084 other thread was already doing one. In either case, don't
3085 resume anything else until the step-over is finished. */
3087 else if (started
&& !target_is_non_stop_p ())
3089 /* A new displaced stepping sequence was started. In all-stop,
3090 we can't talk to the target anymore until it next stops. */
3092 else if (!non_stop
&& target_is_non_stop_p ())
3094 /* In all-stop, but the target is always in non-stop mode.
3095 Start all other threads that are implicitly resumed too. */
3096 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3099 switch_to_thread_no_regs (tp
);
3101 if (!tp
->inf
->has_execution ())
3103 infrun_debug_printf ("[%s] target has no execution",
3104 target_pid_to_str (tp
->ptid
).c_str ());
3110 infrun_debug_printf ("[%s] resumed",
3111 target_pid_to_str (tp
->ptid
).c_str ());
3112 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3116 if (thread_is_in_step_over_chain (tp
))
3118 infrun_debug_printf ("[%s] needs step-over",
3119 target_pid_to_str (tp
->ptid
).c_str ());
3123 infrun_debug_printf ("resuming %s",
3124 target_pid_to_str (tp
->ptid
).c_str ());
3126 reset_ecs (ecs
, tp
);
3127 switch_to_thread (tp
);
3128 keep_going_pass_signal (ecs
);
3129 if (!ecs
->wait_some_more
)
3130 error (_("Command aborted."));
3133 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3135 /* The thread wasn't started, and isn't queued, run it now. */
3136 reset_ecs (ecs
, cur_thr
);
3137 switch_to_thread (cur_thr
);
3138 keep_going_pass_signal (ecs
);
3139 if (!ecs
->wait_some_more
)
3140 error (_("Command aborted."));
3144 commit_resume_all_targets ();
3146 finish_state
.release ();
3148 /* If we've switched threads above, switch back to the previously
3149 current thread. We don't want the user to see a different
3151 switch_to_thread (cur_thr
);
3153 /* Tell the event loop to wait for it to stop. If the target
3154 supports asynchronous execution, it'll do this from within
3156 if (!target_can_async_p ())
3157 mark_async_event_handler (infrun_async_inferior_event_token
);
3161 /* Start remote-debugging of a machine over a serial link. */
3164 start_remote (int from_tty
)
3166 inferior
*inf
= current_inferior ();
3167 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3169 /* Always go on waiting for the target, regardless of the mode. */
3170 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3171 indicate to wait_for_inferior that a target should timeout if
3172 nothing is returned (instead of just blocking). Because of this,
3173 targets expecting an immediate response need to, internally, set
3174 things up so that the target_wait() is forced to eventually
3176 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3177 differentiate to its caller what the state of the target is after
3178 the initial open has been performed. Here we're assuming that
3179 the target has stopped. It should be possible to eventually have
3180 target_open() return to the caller an indication that the target
3181 is currently running and GDB state should be set to the same as
3182 for an async run. */
3183 wait_for_inferior (inf
);
3185 /* Now that the inferior has stopped, do any bookkeeping like
3186 loading shared libraries. We want to do this before normal_stop,
3187 so that the displayed frame is up to date. */
3188 post_create_inferior (current_top_target (), from_tty
);
3193 /* Initialize static vars when a new inferior begins. */
3196 init_wait_for_inferior (void)
3198 /* These are meaningless until the first time through wait_for_inferior. */
3200 breakpoint_init_inferior (inf_starting
);
3202 clear_proceed_status (0);
3204 nullify_last_target_wait_ptid ();
3206 previous_inferior_ptid
= inferior_ptid
;
3211 static void handle_inferior_event (struct execution_control_state
*ecs
);
3213 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3214 struct execution_control_state
*ecs
);
3215 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3216 struct execution_control_state
*ecs
);
3217 static void handle_signal_stop (struct execution_control_state
*ecs
);
3218 static void check_exception_resume (struct execution_control_state
*,
3219 struct frame_info
*);
3221 static void end_stepping_range (struct execution_control_state
*ecs
);
3222 static void stop_waiting (struct execution_control_state
*ecs
);
3223 static void keep_going (struct execution_control_state
*ecs
);
3224 static void process_event_stop_test (struct execution_control_state
*ecs
);
3225 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3227 /* This function is attached as a "thread_stop_requested" observer.
3228 Cleanup local state that assumed the PTID was to be resumed, and
3229 report the stop to the frontend. */
3232 infrun_thread_stop_requested (ptid_t ptid
)
3234 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3236 /* PTID was requested to stop. If the thread was already stopped,
3237 but the user/frontend doesn't know about that yet (e.g., the
3238 thread had been temporarily paused for some step-over), set up
3239 for reporting the stop now. */
3240 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3242 if (tp
->state
!= THREAD_RUNNING
)
3247 /* Remove matching threads from the step-over queue, so
3248 start_step_over doesn't try to resume them
3250 if (thread_is_in_step_over_chain (tp
))
3251 thread_step_over_chain_remove (tp
);
3253 /* If the thread is stopped, but the user/frontend doesn't
3254 know about that yet, queue a pending event, as if the
3255 thread had just stopped now. Unless the thread already had
3257 if (!tp
->suspend
.waitstatus_pending_p
)
3259 tp
->suspend
.waitstatus_pending_p
= 1;
3260 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3261 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3264 /* Clear the inline-frame state, since we're re-processing the
3266 clear_inline_frame_state (tp
);
3268 /* If this thread was paused because some other thread was
3269 doing an inline-step over, let that finish first. Once
3270 that happens, we'll restart all threads and consume pending
3271 stop events then. */
3272 if (step_over_info_valid_p ())
3275 /* Otherwise we can process the (new) pending event now. Set
3276 it so this pending event is considered by
3283 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3285 if (target_last_proc_target
== tp
->inf
->process_target ()
3286 && target_last_wait_ptid
== tp
->ptid
)
3287 nullify_last_target_wait_ptid ();
3290 /* Delete the step resume, single-step and longjmp/exception resume
3291 breakpoints of TP. */
3294 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3296 delete_step_resume_breakpoint (tp
);
3297 delete_exception_resume_breakpoint (tp
);
3298 delete_single_step_breakpoints (tp
);
3301 /* If the target still has execution, call FUNC for each thread that
3302 just stopped. In all-stop, that's all the non-exited threads; in
3303 non-stop, that's the current thread, only. */
3305 typedef void (*for_each_just_stopped_thread_callback_func
)
3306 (struct thread_info
*tp
);
3309 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3311 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3314 if (target_is_non_stop_p ())
3316 /* If in non-stop mode, only the current thread stopped. */
3317 func (inferior_thread ());
3321 /* In all-stop mode, all threads have stopped. */
3322 for (thread_info
*tp
: all_non_exited_threads ())
3327 /* Delete the step resume and longjmp/exception resume breakpoints of
3328 the threads that just stopped. */
3331 delete_just_stopped_threads_infrun_breakpoints (void)
3333 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3336 /* Delete the single-step breakpoints of the threads that just
3340 delete_just_stopped_threads_single_step_breakpoints (void)
3342 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3348 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3349 const struct target_waitstatus
*ws
)
3351 std::string status_string
= target_waitstatus_to_string (ws
);
3354 /* The text is split over several lines because it was getting too long.
3355 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3356 output as a unit; we want only one timestamp printed if debug_timestamp
3359 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3362 waiton_ptid
.tid ());
3363 if (waiton_ptid
.pid () != -1)
3364 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3365 stb
.printf (", status) =\n");
3366 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3370 target_pid_to_str (result_ptid
).c_str ());
3371 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3373 /* This uses %s in part to handle %'s in the text, but also to avoid
3374 a gcc error: the format attribute requires a string literal. */
3375 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3378 /* Select a thread at random, out of those which are resumed and have
3381 static struct thread_info
*
3382 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3386 auto has_event
= [&] (thread_info
*tp
)
3388 return (tp
->ptid
.matches (waiton_ptid
)
3390 && tp
->suspend
.waitstatus_pending_p
);
3393 /* First see how many events we have. Count only resumed threads
3394 that have an event pending. */
3395 for (thread_info
*tp
: inf
->non_exited_threads ())
3399 if (num_events
== 0)
3402 /* Now randomly pick a thread out of those that have had events. */
3403 int random_selector
= (int) ((num_events
* (double) rand ())
3404 / (RAND_MAX
+ 1.0));
3407 infrun_debug_printf ("Found %d events, selecting #%d",
3408 num_events
, random_selector
);
3410 /* Select the Nth thread that has had an event. */
3411 for (thread_info
*tp
: inf
->non_exited_threads ())
3413 if (random_selector
-- == 0)
3416 gdb_assert_not_reached ("event thread not found");
3419 /* Wrapper for target_wait that first checks whether threads have
3420 pending statuses to report before actually asking the target for
3421 more events. INF is the inferior we're using to call target_wait
3425 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3426 target_waitstatus
*status
, int options
)
3429 struct thread_info
*tp
;
3431 /* We know that we are looking for an event in the target of inferior
3432 INF, but we don't know which thread the event might come from. As
3433 such we want to make sure that INFERIOR_PTID is reset so that none of
3434 the wait code relies on it - doing so is always a mistake. */
3435 switch_to_inferior_no_thread (inf
);
3437 /* First check if there is a resumed thread with a wait status
3439 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3441 tp
= random_pending_event_thread (inf
, ptid
);
3445 infrun_debug_printf ("Waiting for specific thread %s.",
3446 target_pid_to_str (ptid
).c_str ());
3448 /* We have a specific thread to check. */
3449 tp
= find_thread_ptid (inf
, ptid
);
3450 gdb_assert (tp
!= NULL
);
3451 if (!tp
->suspend
.waitstatus_pending_p
)
3456 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3457 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3459 struct regcache
*regcache
= get_thread_regcache (tp
);
3460 struct gdbarch
*gdbarch
= regcache
->arch ();
3464 pc
= regcache_read_pc (regcache
);
3466 if (pc
!= tp
->suspend
.stop_pc
)
3468 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3469 target_pid_to_str (tp
->ptid
).c_str (),
3470 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3471 paddress (gdbarch
, pc
));
3474 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3476 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3477 target_pid_to_str (tp
->ptid
).c_str (),
3478 paddress (gdbarch
, pc
));
3485 infrun_debug_printf ("pending event of %s cancelled.",
3486 target_pid_to_str (tp
->ptid
).c_str ());
3488 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3489 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3495 infrun_debug_printf ("Using pending wait status %s for %s.",
3496 target_waitstatus_to_string
3497 (&tp
->suspend
.waitstatus
).c_str (),
3498 target_pid_to_str (tp
->ptid
).c_str ());
3500 /* Now that we've selected our final event LWP, un-adjust its PC
3501 if it was a software breakpoint (and the target doesn't
3502 always adjust the PC itself). */
3503 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3504 && !target_supports_stopped_by_sw_breakpoint ())
3506 struct regcache
*regcache
;
3507 struct gdbarch
*gdbarch
;
3510 regcache
= get_thread_regcache (tp
);
3511 gdbarch
= regcache
->arch ();
3513 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3518 pc
= regcache_read_pc (regcache
);
3519 regcache_write_pc (regcache
, pc
+ decr_pc
);
3523 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3524 *status
= tp
->suspend
.waitstatus
;
3525 tp
->suspend
.waitstatus_pending_p
= 0;
3527 /* Wake up the event loop again, until all pending events are
3529 if (target_is_async_p ())
3530 mark_async_event_handler (infrun_async_inferior_event_token
);
3534 /* But if we don't find one, we'll have to wait. */
3536 if (deprecated_target_wait_hook
)
3537 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3539 event_ptid
= target_wait (ptid
, status
, options
);
3544 /* Wrapper for target_wait that first checks whether threads have
3545 pending statuses to report before actually asking the target for
3546 more events. Polls for events from all inferiors/targets. */
3549 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3551 int num_inferiors
= 0;
3552 int random_selector
;
3554 /* For fairness, we pick the first inferior/target to poll at random
3555 out of all inferiors that may report events, and then continue
3556 polling the rest of the inferior list starting from that one in a
3557 circular fashion until the whole list is polled once. */
3559 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3561 return (inf
->process_target () != NULL
3562 && ptid_t (inf
->pid
).matches (wait_ptid
));
3565 /* First see how many matching inferiors we have. */
3566 for (inferior
*inf
: all_inferiors ())
3567 if (inferior_matches (inf
))
3570 if (num_inferiors
== 0)
3572 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3576 /* Now randomly pick an inferior out of those that matched. */
3577 random_selector
= (int)
3578 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3580 if (num_inferiors
> 1)
3581 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3582 num_inferiors
, random_selector
);
3584 /* Select the Nth inferior that matched. */
3586 inferior
*selected
= nullptr;
3588 for (inferior
*inf
: all_inferiors ())
3589 if (inferior_matches (inf
))
3590 if (random_selector
-- == 0)
3596 /* Now poll for events out of each of the matching inferior's
3597 targets, starting from the selected one. */
3599 auto do_wait
= [&] (inferior
*inf
)
3601 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3602 ecs
->target
= inf
->process_target ();
3603 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3606 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3607 here spuriously after the target is all stopped and we've already
3608 reported the stop to the user, polling for events. */
3609 scoped_restore_current_thread restore_thread
;
3611 int inf_num
= selected
->num
;
3612 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3613 if (inferior_matches (inf
))
3617 for (inferior
*inf
= inferior_list
;
3618 inf
!= NULL
&& inf
->num
< inf_num
;
3620 if (inferior_matches (inf
))
3624 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3628 /* Prepare and stabilize the inferior for detaching it. E.g.,
3629 detaching while a thread is displaced stepping is a recipe for
3630 crashing it, as nothing would readjust the PC out of the scratch
3634 prepare_for_detach (void)
3636 struct inferior
*inf
= current_inferior ();
3637 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3639 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3641 /* Is any thread of this process displaced stepping? If not,
3642 there's nothing else to do. */
3643 if (displaced
->step_thread
== nullptr)
3646 infrun_debug_printf ("displaced-stepping in-process while detaching");
3648 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3650 while (displaced
->step_thread
!= nullptr)
3652 struct execution_control_state ecss
;
3653 struct execution_control_state
*ecs
;
3656 memset (ecs
, 0, sizeof (*ecs
));
3658 overlay_cache_invalid
= 1;
3659 /* Flush target cache before starting to handle each event.
3660 Target was running and cache could be stale. This is just a
3661 heuristic. Running threads may modify target memory, but we
3662 don't get any event. */
3663 target_dcache_invalidate ();
3665 do_target_wait (pid_ptid
, ecs
, 0);
3668 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3670 /* If an error happens while handling the event, propagate GDB's
3671 knowledge of the executing state to the frontend/user running
3673 scoped_finish_thread_state
finish_state (inf
->process_target (),
3676 /* Now figure out what to do with the result of the result. */
3677 handle_inferior_event (ecs
);
3679 /* No error, don't finish the state yet. */
3680 finish_state
.release ();
3682 /* Breakpoints and watchpoints are not installed on the target
3683 at this point, and signals are passed directly to the
3684 inferior, so this must mean the process is gone. */
3685 if (!ecs
->wait_some_more
)
3687 restore_detaching
.release ();
3688 error (_("Program exited while detaching"));
3692 restore_detaching
.release ();
3695 /* Wait for control to return from inferior to debugger.
3697 If inferior gets a signal, we may decide to start it up again
3698 instead of returning. That is why there is a loop in this function.
3699 When this function actually returns it means the inferior
3700 should be left stopped and GDB should read more commands. */
3703 wait_for_inferior (inferior
*inf
)
3705 infrun_debug_printf ("wait_for_inferior ()");
3707 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3709 /* If an error happens while handling the event, propagate GDB's
3710 knowledge of the executing state to the frontend/user running
3712 scoped_finish_thread_state finish_state
3713 (inf
->process_target (), minus_one_ptid
);
3717 struct execution_control_state ecss
;
3718 struct execution_control_state
*ecs
= &ecss
;
3720 memset (ecs
, 0, sizeof (*ecs
));
3722 overlay_cache_invalid
= 1;
3724 /* Flush target cache before starting to handle each event.
3725 Target was running and cache could be stale. This is just a
3726 heuristic. Running threads may modify target memory, but we
3727 don't get any event. */
3728 target_dcache_invalidate ();
3730 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3731 ecs
->target
= inf
->process_target ();
3734 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3736 /* Now figure out what to do with the result of the result. */
3737 handle_inferior_event (ecs
);
3739 if (!ecs
->wait_some_more
)
3743 /* No error, don't finish the state yet. */
3744 finish_state
.release ();
3747 /* Cleanup that reinstalls the readline callback handler, if the
3748 target is running in the background. If while handling the target
3749 event something triggered a secondary prompt, like e.g., a
3750 pagination prompt, we'll have removed the callback handler (see
3751 gdb_readline_wrapper_line). Need to do this as we go back to the
3752 event loop, ready to process further input. Note this has no
3753 effect if the handler hasn't actually been removed, because calling
3754 rl_callback_handler_install resets the line buffer, thus losing
3758 reinstall_readline_callback_handler_cleanup ()
3760 struct ui
*ui
= current_ui
;
3764 /* We're not going back to the top level event loop yet. Don't
3765 install the readline callback, as it'd prep the terminal,
3766 readline-style (raw, noecho) (e.g., --batch). We'll install
3767 it the next time the prompt is displayed, when we're ready
3772 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3773 gdb_rl_callback_handler_reinstall ();
3776 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3777 that's just the event thread. In all-stop, that's all threads. */
3780 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3782 if (ecs
->event_thread
!= NULL
3783 && ecs
->event_thread
->thread_fsm
!= NULL
)
3784 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3788 for (thread_info
*thr
: all_non_exited_threads ())
3790 if (thr
->thread_fsm
== NULL
)
3792 if (thr
== ecs
->event_thread
)
3795 switch_to_thread (thr
);
3796 thr
->thread_fsm
->clean_up (thr
);
3799 if (ecs
->event_thread
!= NULL
)
3800 switch_to_thread (ecs
->event_thread
);
3804 /* Helper for all_uis_check_sync_execution_done that works on the
3808 check_curr_ui_sync_execution_done (void)
3810 struct ui
*ui
= current_ui
;
3812 if (ui
->prompt_state
== PROMPT_NEEDED
3814 && !gdb_in_secondary_prompt_p (ui
))
3816 target_terminal::ours ();
3817 gdb::observers::sync_execution_done
.notify ();
3818 ui_register_input_event_handler (ui
);
3825 all_uis_check_sync_execution_done (void)
3827 SWITCH_THRU_ALL_UIS ()
3829 check_curr_ui_sync_execution_done ();
3836 all_uis_on_sync_execution_starting (void)
3838 SWITCH_THRU_ALL_UIS ()
3840 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3841 async_disable_stdin ();
3845 /* Asynchronous version of wait_for_inferior. It is called by the
3846 event loop whenever a change of state is detected on the file
3847 descriptor corresponding to the target. It can be called more than
3848 once to complete a single execution command. In such cases we need
3849 to keep the state in a global variable ECSS. If it is the last time
3850 that this function is called for a single execution command, then
3851 report to the user that the inferior has stopped, and do the
3852 necessary cleanups. */
3855 fetch_inferior_event ()
3857 struct execution_control_state ecss
;
3858 struct execution_control_state
*ecs
= &ecss
;
3861 memset (ecs
, 0, sizeof (*ecs
));
3863 /* Events are always processed with the main UI as current UI. This
3864 way, warnings, debug output, etc. are always consistently sent to
3865 the main console. */
3866 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3868 /* End up with readline processing input, if necessary. */
3870 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3872 /* We're handling a live event, so make sure we're doing live
3873 debugging. If we're looking at traceframes while the target is
3874 running, we're going to need to get back to that mode after
3875 handling the event. */
3876 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3879 maybe_restore_traceframe
.emplace ();
3880 set_current_traceframe (-1);
3883 /* The user/frontend should not notice a thread switch due to
3884 internal events. Make sure we revert to the user selected
3885 thread and frame after handling the event and running any
3886 breakpoint commands. */
3887 scoped_restore_current_thread restore_thread
;
3889 overlay_cache_invalid
= 1;
3890 /* Flush target cache before starting to handle each event. Target
3891 was running and cache could be stale. This is just a heuristic.
3892 Running threads may modify target memory, but we don't get any
3894 target_dcache_invalidate ();
3896 scoped_restore save_exec_dir
3897 = make_scoped_restore (&execution_direction
,
3898 target_execution_direction ());
3900 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3903 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3905 /* Switch to the target that generated the event, so we can do
3906 target calls. Any inferior bound to the target will do, so we
3907 just switch to the first we find. */
3908 for (inferior
*inf
: all_inferiors (ecs
->target
))
3910 switch_to_inferior_no_thread (inf
);
3915 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3917 /* If an error happens while handling the event, propagate GDB's
3918 knowledge of the executing state to the frontend/user running
3920 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3921 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3923 /* Get executed before scoped_restore_current_thread above to apply
3924 still for the thread which has thrown the exception. */
3925 auto defer_bpstat_clear
3926 = make_scope_exit (bpstat_clear_actions
);
3927 auto defer_delete_threads
3928 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3930 /* Now figure out what to do with the result of the result. */
3931 handle_inferior_event (ecs
);
3933 if (!ecs
->wait_some_more
)
3935 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3936 int should_stop
= 1;
3937 struct thread_info
*thr
= ecs
->event_thread
;
3939 delete_just_stopped_threads_infrun_breakpoints ();
3943 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3945 if (thread_fsm
!= NULL
)
3946 should_stop
= thread_fsm
->should_stop (thr
);
3955 bool should_notify_stop
= true;
3958 clean_up_just_stopped_threads_fsms (ecs
);
3960 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3961 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3963 if (should_notify_stop
)
3965 /* We may not find an inferior if this was a process exit. */
3966 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3967 proceeded
= normal_stop ();
3972 inferior_event_handler (INF_EXEC_COMPLETE
);
3976 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3977 previously selected thread is gone. We have two
3978 choices - switch to no thread selected, or restore the
3979 previously selected thread (now exited). We chose the
3980 later, just because that's what GDB used to do. After
3981 this, "info threads" says "The current thread <Thread
3982 ID 2> has terminated." instead of "No thread
3986 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3987 restore_thread
.dont_restore ();
3991 defer_delete_threads
.release ();
3992 defer_bpstat_clear
.release ();
3994 /* No error, don't finish the thread states yet. */
3995 finish_state
.release ();
3997 /* This scope is used to ensure that readline callbacks are
3998 reinstalled here. */
4001 /* If a UI was in sync execution mode, and now isn't, restore its
4002 prompt (a synchronous execution command has finished, and we're
4003 ready for input). */
4004 all_uis_check_sync_execution_done ();
4007 && exec_done_display_p
4008 && (inferior_ptid
== null_ptid
4009 || inferior_thread ()->state
!= THREAD_RUNNING
))
4010 printf_unfiltered (_("completed.\n"));
4016 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4017 struct symtab_and_line sal
)
4019 /* This can be removed once this function no longer implicitly relies on the
4020 inferior_ptid value. */
4021 gdb_assert (inferior_ptid
== tp
->ptid
);
4023 tp
->control
.step_frame_id
= get_frame_id (frame
);
4024 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4026 tp
->current_symtab
= sal
.symtab
;
4027 tp
->current_line
= sal
.line
;
4030 /* Clear context switchable stepping state. */
4033 init_thread_stepping_state (struct thread_info
*tss
)
4035 tss
->stepped_breakpoint
= 0;
4036 tss
->stepping_over_breakpoint
= 0;
4037 tss
->stepping_over_watchpoint
= 0;
4038 tss
->step_after_step_resume_breakpoint
= 0;
4044 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4045 target_waitstatus status
)
4047 target_last_proc_target
= target
;
4048 target_last_wait_ptid
= ptid
;
4049 target_last_waitstatus
= status
;
4055 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4056 target_waitstatus
*status
)
4058 if (target
!= nullptr)
4059 *target
= target_last_proc_target
;
4060 if (ptid
!= nullptr)
4061 *ptid
= target_last_wait_ptid
;
4062 if (status
!= nullptr)
4063 *status
= target_last_waitstatus
;
4069 nullify_last_target_wait_ptid (void)
4071 target_last_proc_target
= nullptr;
4072 target_last_wait_ptid
= minus_one_ptid
;
4073 target_last_waitstatus
= {};
4076 /* Switch thread contexts. */
4079 context_switch (execution_control_state
*ecs
)
4081 if (ecs
->ptid
!= inferior_ptid
4082 && (inferior_ptid
== null_ptid
4083 || ecs
->event_thread
!= inferior_thread ()))
4085 infrun_debug_printf ("Switching context from %s to %s",
4086 target_pid_to_str (inferior_ptid
).c_str (),
4087 target_pid_to_str (ecs
->ptid
).c_str ());
4090 switch_to_thread (ecs
->event_thread
);
4093 /* If the target can't tell whether we've hit breakpoints
4094 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4095 check whether that could have been caused by a breakpoint. If so,
4096 adjust the PC, per gdbarch_decr_pc_after_break. */
4099 adjust_pc_after_break (struct thread_info
*thread
,
4100 struct target_waitstatus
*ws
)
4102 struct regcache
*regcache
;
4103 struct gdbarch
*gdbarch
;
4104 CORE_ADDR breakpoint_pc
, decr_pc
;
4106 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4107 we aren't, just return.
4109 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4110 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4111 implemented by software breakpoints should be handled through the normal
4114 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4115 different signals (SIGILL or SIGEMT for instance), but it is less
4116 clear where the PC is pointing afterwards. It may not match
4117 gdbarch_decr_pc_after_break. I don't know any specific target that
4118 generates these signals at breakpoints (the code has been in GDB since at
4119 least 1992) so I can not guess how to handle them here.
4121 In earlier versions of GDB, a target with
4122 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4123 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4124 target with both of these set in GDB history, and it seems unlikely to be
4125 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4127 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4130 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4133 /* In reverse execution, when a breakpoint is hit, the instruction
4134 under it has already been de-executed. The reported PC always
4135 points at the breakpoint address, so adjusting it further would
4136 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4139 B1 0x08000000 : INSN1
4140 B2 0x08000001 : INSN2
4142 PC -> 0x08000003 : INSN4
4144 Say you're stopped at 0x08000003 as above. Reverse continuing
4145 from that point should hit B2 as below. Reading the PC when the
4146 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4147 been de-executed already.
4149 B1 0x08000000 : INSN1
4150 B2 PC -> 0x08000001 : INSN2
4154 We can't apply the same logic as for forward execution, because
4155 we would wrongly adjust the PC to 0x08000000, since there's a
4156 breakpoint at PC - 1. We'd then report a hit on B1, although
4157 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4159 if (execution_direction
== EXEC_REVERSE
)
4162 /* If the target can tell whether the thread hit a SW breakpoint,
4163 trust it. Targets that can tell also adjust the PC
4165 if (target_supports_stopped_by_sw_breakpoint ())
4168 /* Note that relying on whether a breakpoint is planted in memory to
4169 determine this can fail. E.g,. the breakpoint could have been
4170 removed since. Or the thread could have been told to step an
4171 instruction the size of a breakpoint instruction, and only
4172 _after_ was a breakpoint inserted at its address. */
4174 /* If this target does not decrement the PC after breakpoints, then
4175 we have nothing to do. */
4176 regcache
= get_thread_regcache (thread
);
4177 gdbarch
= regcache
->arch ();
4179 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4183 const address_space
*aspace
= regcache
->aspace ();
4185 /* Find the location where (if we've hit a breakpoint) the
4186 breakpoint would be. */
4187 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4189 /* If the target can't tell whether a software breakpoint triggered,
4190 fallback to figuring it out based on breakpoints we think were
4191 inserted in the target, and on whether the thread was stepped or
4194 /* Check whether there actually is a software breakpoint inserted at
4197 If in non-stop mode, a race condition is possible where we've
4198 removed a breakpoint, but stop events for that breakpoint were
4199 already queued and arrive later. To suppress those spurious
4200 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4201 and retire them after a number of stop events are reported. Note
4202 this is an heuristic and can thus get confused. The real fix is
4203 to get the "stopped by SW BP and needs adjustment" info out of
4204 the target/kernel (and thus never reach here; see above). */
4205 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4206 || (target_is_non_stop_p ()
4207 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4209 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4211 if (record_full_is_used ())
4212 restore_operation_disable
.emplace
4213 (record_full_gdb_operation_disable_set ());
4215 /* When using hardware single-step, a SIGTRAP is reported for both
4216 a completed single-step and a software breakpoint. Need to
4217 differentiate between the two, as the latter needs adjusting
4218 but the former does not.
4220 The SIGTRAP can be due to a completed hardware single-step only if
4221 - we didn't insert software single-step breakpoints
4222 - this thread is currently being stepped
4224 If any of these events did not occur, we must have stopped due
4225 to hitting a software breakpoint, and have to back up to the
4228 As a special case, we could have hardware single-stepped a
4229 software breakpoint. In this case (prev_pc == breakpoint_pc),
4230 we also need to back up to the breakpoint address. */
4232 if (thread_has_single_step_breakpoints_set (thread
)
4233 || !currently_stepping (thread
)
4234 || (thread
->stepped_breakpoint
4235 && thread
->prev_pc
== breakpoint_pc
))
4236 regcache_write_pc (regcache
, breakpoint_pc
);
4241 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4243 for (frame
= get_prev_frame (frame
);
4245 frame
= get_prev_frame (frame
))
4247 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4249 if (get_frame_type (frame
) != INLINE_FRAME
)
4256 /* Look for an inline frame that is marked for skip.
4257 If PREV_FRAME is TRUE start at the previous frame,
4258 otherwise start at the current frame. Stop at the
4259 first non-inline frame, or at the frame where the
4263 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4265 struct frame_info
*frame
= get_current_frame ();
4268 frame
= get_prev_frame (frame
);
4270 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4272 const char *fn
= NULL
;
4273 symtab_and_line sal
;
4276 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4278 if (get_frame_type (frame
) != INLINE_FRAME
)
4281 sal
= find_frame_sal (frame
);
4282 sym
= get_frame_function (frame
);
4285 fn
= sym
->print_name ();
4288 && function_name_is_marked_for_skip (fn
, sal
))
4295 /* If the event thread has the stop requested flag set, pretend it
4296 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4300 handle_stop_requested (struct execution_control_state
*ecs
)
4302 if (ecs
->event_thread
->stop_requested
)
4304 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4305 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4306 handle_signal_stop (ecs
);
4312 /* Auxiliary function that handles syscall entry/return events.
4313 It returns 1 if the inferior should keep going (and GDB
4314 should ignore the event), or 0 if the event deserves to be
4318 handle_syscall_event (struct execution_control_state
*ecs
)
4320 struct regcache
*regcache
;
4323 context_switch (ecs
);
4325 regcache
= get_thread_regcache (ecs
->event_thread
);
4326 syscall_number
= ecs
->ws
.value
.syscall_number
;
4327 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4329 if (catch_syscall_enabled () > 0
4330 && catching_syscall_number (syscall_number
) > 0)
4332 infrun_debug_printf ("syscall number=%d", syscall_number
);
4334 ecs
->event_thread
->control
.stop_bpstat
4335 = bpstat_stop_status (regcache
->aspace (),
4336 ecs
->event_thread
->suspend
.stop_pc
,
4337 ecs
->event_thread
, &ecs
->ws
);
4339 if (handle_stop_requested (ecs
))
4342 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4344 /* Catchpoint hit. */
4349 if (handle_stop_requested (ecs
))
4352 /* If no catchpoint triggered for this, then keep going. */
4357 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4360 fill_in_stop_func (struct gdbarch
*gdbarch
,
4361 struct execution_control_state
*ecs
)
4363 if (!ecs
->stop_func_filled_in
)
4367 /* Don't care about return value; stop_func_start and stop_func_name
4368 will both be 0 if it doesn't work. */
4369 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4370 &ecs
->stop_func_name
,
4371 &ecs
->stop_func_start
,
4372 &ecs
->stop_func_end
,
4375 /* The call to find_pc_partial_function, above, will set
4376 stop_func_start and stop_func_end to the start and end
4377 of the range containing the stop pc. If this range
4378 contains the entry pc for the block (which is always the
4379 case for contiguous blocks), advance stop_func_start past
4380 the function's start offset and entrypoint. Note that
4381 stop_func_start is NOT advanced when in a range of a
4382 non-contiguous block that does not contain the entry pc. */
4383 if (block
!= nullptr
4384 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4385 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4387 ecs
->stop_func_start
4388 += gdbarch_deprecated_function_start_offset (gdbarch
);
4390 if (gdbarch_skip_entrypoint_p (gdbarch
))
4391 ecs
->stop_func_start
4392 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4395 ecs
->stop_func_filled_in
= 1;
4400 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4402 static enum stop_kind
4403 get_inferior_stop_soon (execution_control_state
*ecs
)
4405 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4407 gdb_assert (inf
!= NULL
);
4408 return inf
->control
.stop_soon
;
4411 /* Poll for one event out of the current target. Store the resulting
4412 waitstatus in WS, and return the event ptid. Does not block. */
4415 poll_one_curr_target (struct target_waitstatus
*ws
)
4419 overlay_cache_invalid
= 1;
4421 /* Flush target cache before starting to handle each event.
4422 Target was running and cache could be stale. This is just a
4423 heuristic. Running threads may modify target memory, but we
4424 don't get any event. */
4425 target_dcache_invalidate ();
4427 if (deprecated_target_wait_hook
)
4428 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4430 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4433 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4438 /* An event reported by wait_one. */
4440 struct wait_one_event
4442 /* The target the event came out of. */
4443 process_stratum_target
*target
;
4445 /* The PTID the event was for. */
4448 /* The waitstatus. */
4449 target_waitstatus ws
;
4452 /* Wait for one event out of any target. */
4454 static wait_one_event
4459 for (inferior
*inf
: all_inferiors ())
4461 process_stratum_target
*target
= inf
->process_target ();
4463 || !target
->is_async_p ()
4464 || !target
->threads_executing
)
4467 switch_to_inferior_no_thread (inf
);
4469 wait_one_event event
;
4470 event
.target
= target
;
4471 event
.ptid
= poll_one_curr_target (&event
.ws
);
4473 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4475 /* If nothing is resumed, remove the target from the
4479 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4483 /* Block waiting for some event. */
4490 for (inferior
*inf
: all_inferiors ())
4492 process_stratum_target
*target
= inf
->process_target ();
4494 || !target
->is_async_p ()
4495 || !target
->threads_executing
)
4498 int fd
= target
->async_wait_fd ();
4499 FD_SET (fd
, &readfds
);
4506 /* No waitable targets left. All must be stopped. */
4507 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4512 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4518 perror_with_name ("interruptible_select");
4523 /* Save the thread's event and stop reason to process it later. */
4526 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4528 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4529 target_waitstatus_to_string (ws
).c_str (),
4534 /* Record for later. */
4535 tp
->suspend
.waitstatus
= *ws
;
4536 tp
->suspend
.waitstatus_pending_p
= 1;
4538 struct regcache
*regcache
= get_thread_regcache (tp
);
4539 const address_space
*aspace
= regcache
->aspace ();
4541 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4542 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4544 CORE_ADDR pc
= regcache_read_pc (regcache
);
4546 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4548 scoped_restore_current_thread restore_thread
;
4549 switch_to_thread (tp
);
4551 if (target_stopped_by_watchpoint ())
4553 tp
->suspend
.stop_reason
4554 = TARGET_STOPPED_BY_WATCHPOINT
;
4556 else if (target_supports_stopped_by_sw_breakpoint ()
4557 && target_stopped_by_sw_breakpoint ())
4559 tp
->suspend
.stop_reason
4560 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4562 else if (target_supports_stopped_by_hw_breakpoint ()
4563 && target_stopped_by_hw_breakpoint ())
4565 tp
->suspend
.stop_reason
4566 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4568 else if (!target_supports_stopped_by_hw_breakpoint ()
4569 && hardware_breakpoint_inserted_here_p (aspace
,
4572 tp
->suspend
.stop_reason
4573 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4575 else if (!target_supports_stopped_by_sw_breakpoint ()
4576 && software_breakpoint_inserted_here_p (aspace
,
4579 tp
->suspend
.stop_reason
4580 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4582 else if (!thread_has_single_step_breakpoints_set (tp
)
4583 && currently_stepping (tp
))
4585 tp
->suspend
.stop_reason
4586 = TARGET_STOPPED_BY_SINGLE_STEP
;
4591 /* Mark the non-executing threads accordingly. In all-stop, all
4592 threads of all processes are stopped when we get any event
4593 reported. In non-stop mode, only the event thread stops. */
4596 mark_non_executing_threads (process_stratum_target
*target
,
4598 struct target_waitstatus ws
)
4602 if (!target_is_non_stop_p ())
4603 mark_ptid
= minus_one_ptid
;
4604 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4605 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4607 /* If we're handling a process exit in non-stop mode, even
4608 though threads haven't been deleted yet, one would think
4609 that there is nothing to do, as threads of the dead process
4610 will be soon deleted, and threads of any other process were
4611 left running. However, on some targets, threads survive a
4612 process exit event. E.g., for the "checkpoint" command,
4613 when the current checkpoint/fork exits, linux-fork.c
4614 automatically switches to another fork from within
4615 target_mourn_inferior, by associating the same
4616 inferior/thread to another fork. We haven't mourned yet at
4617 this point, but we must mark any threads left in the
4618 process as not-executing so that finish_thread_state marks
4619 them stopped (in the user's perspective) if/when we present
4620 the stop to the user. */
4621 mark_ptid
= ptid_t (event_ptid
.pid ());
4624 mark_ptid
= event_ptid
;
4626 set_executing (target
, mark_ptid
, false);
4628 /* Likewise the resumed flag. */
4629 set_resumed (target
, mark_ptid
, false);
4635 stop_all_threads (void)
4637 /* We may need multiple passes to discover all threads. */
4641 gdb_assert (exists_non_stop_target ());
4643 infrun_debug_printf ("starting");
4645 scoped_restore_current_thread restore_thread
;
4647 /* Enable thread events of all targets. */
4648 for (auto *target
: all_non_exited_process_targets ())
4650 switch_to_target_no_thread (target
);
4651 target_thread_events (true);
4656 /* Disable thread events of all targets. */
4657 for (auto *target
: all_non_exited_process_targets ())
4659 switch_to_target_no_thread (target
);
4660 target_thread_events (false);
4663 /* Use infrun_debug_printf_1 directly to get a meaningful function
4666 infrun_debug_printf_1 ("stop_all_threads", "done");
4669 /* Request threads to stop, and then wait for the stops. Because
4670 threads we already know about can spawn more threads while we're
4671 trying to stop them, and we only learn about new threads when we
4672 update the thread list, do this in a loop, and keep iterating
4673 until two passes find no threads that need to be stopped. */
4674 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4676 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4679 int waits_needed
= 0;
4681 for (auto *target
: all_non_exited_process_targets ())
4683 switch_to_target_no_thread (target
);
4684 update_thread_list ();
4687 /* Go through all threads looking for threads that we need
4688 to tell the target to stop. */
4689 for (thread_info
*t
: all_non_exited_threads ())
4691 /* For a single-target setting with an all-stop target,
4692 we would not even arrive here. For a multi-target
4693 setting, until GDB is able to handle a mixture of
4694 all-stop and non-stop targets, simply skip all-stop
4695 targets' threads. This should be fine due to the
4696 protection of 'check_multi_target_resumption'. */
4698 switch_to_thread_no_regs (t
);
4699 if (!target_is_non_stop_p ())
4704 /* If already stopping, don't request a stop again.
4705 We just haven't seen the notification yet. */
4706 if (!t
->stop_requested
)
4708 infrun_debug_printf (" %s executing, need stop",
4709 target_pid_to_str (t
->ptid
).c_str ());
4710 target_stop (t
->ptid
);
4711 t
->stop_requested
= 1;
4715 infrun_debug_printf (" %s executing, already stopping",
4716 target_pid_to_str (t
->ptid
).c_str ());
4719 if (t
->stop_requested
)
4724 infrun_debug_printf (" %s not executing",
4725 target_pid_to_str (t
->ptid
).c_str ());
4727 /* The thread may be not executing, but still be
4728 resumed with a pending status to process. */
4733 if (waits_needed
== 0)
4736 /* If we find new threads on the second iteration, restart
4737 over. We want to see two iterations in a row with all
4742 for (int i
= 0; i
< waits_needed
; i
++)
4744 wait_one_event event
= wait_one ();
4747 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4748 target_pid_to_str (event
.ptid
).c_str ());
4750 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4752 /* All resumed threads exited. */
4755 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4756 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4757 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4759 /* One thread/process exited/signalled. */
4761 thread_info
*t
= nullptr;
4763 /* The target may have reported just a pid. If so, try
4764 the first non-exited thread. */
4765 if (event
.ptid
.is_pid ())
4767 int pid
= event
.ptid
.pid ();
4768 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4769 for (thread_info
*tp
: inf
->non_exited_threads ())
4775 /* If there is no available thread, the event would
4776 have to be appended to a per-inferior event list,
4777 which does not exist (and if it did, we'd have
4778 to adjust run control command to be able to
4779 resume such an inferior). We assert here instead
4780 of going into an infinite loop. */
4781 gdb_assert (t
!= nullptr);
4784 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4788 t
= find_thread_ptid (event
.target
, event
.ptid
);
4789 /* Check if this is the first time we see this thread.
4790 Don't bother adding if it individually exited. */
4792 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4793 t
= add_thread (event
.target
, event
.ptid
);
4798 /* Set the threads as non-executing to avoid
4799 another stop attempt on them. */
4800 switch_to_thread_no_regs (t
);
4801 mark_non_executing_threads (event
.target
, event
.ptid
,
4803 save_waitstatus (t
, &event
.ws
);
4804 t
->stop_requested
= false;
4809 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4811 t
= add_thread (event
.target
, event
.ptid
);
4813 t
->stop_requested
= 0;
4816 t
->control
.may_range_step
= 0;
4818 /* This may be the first time we see the inferior report
4820 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4821 if (inf
->needs_setup
)
4823 switch_to_thread_no_regs (t
);
4827 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4828 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4830 /* We caught the event that we intended to catch, so
4831 there's no event pending. */
4832 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4833 t
->suspend
.waitstatus_pending_p
= 0;
4835 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4837 /* Add it back to the step-over queue. */
4839 ("displaced-step of %s canceled: adding back to "
4840 "the step-over queue",
4841 target_pid_to_str (t
->ptid
).c_str ());
4843 t
->control
.trap_expected
= 0;
4844 thread_step_over_chain_enqueue (t
);
4849 enum gdb_signal sig
;
4850 struct regcache
*regcache
;
4853 ("target_wait %s, saving status for %d.%ld.%ld",
4854 target_waitstatus_to_string (&event
.ws
).c_str (),
4855 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4857 /* Record for later. */
4858 save_waitstatus (t
, &event
.ws
);
4860 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4861 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4863 if (displaced_step_fixup (t
, sig
) < 0)
4865 /* Add it back to the step-over queue. */
4866 t
->control
.trap_expected
= 0;
4867 thread_step_over_chain_enqueue (t
);
4870 regcache
= get_thread_regcache (t
);
4871 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4873 infrun_debug_printf ("saved stop_pc=%s for %s "
4874 "(currently_stepping=%d)",
4875 paddress (target_gdbarch (),
4876 t
->suspend
.stop_pc
),
4877 target_pid_to_str (t
->ptid
).c_str (),
4878 currently_stepping (t
));
4886 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4889 handle_no_resumed (struct execution_control_state
*ecs
)
4891 if (target_can_async_p ())
4895 for (ui
*ui
: all_uis ())
4897 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4905 /* There were no unwaited-for children left in the target, but,
4906 we're not synchronously waiting for events either. Just
4909 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4910 prepare_to_wait (ecs
);
4915 /* Otherwise, if we were running a synchronous execution command, we
4916 may need to cancel it and give the user back the terminal.
4918 In non-stop mode, the target can't tell whether we've already
4919 consumed previous stop events, so it can end up sending us a
4920 no-resumed event like so:
4922 #0 - thread 1 is left stopped
4924 #1 - thread 2 is resumed and hits breakpoint
4925 -> TARGET_WAITKIND_STOPPED
4927 #2 - thread 3 is resumed and exits
4928 this is the last resumed thread, so
4929 -> TARGET_WAITKIND_NO_RESUMED
4931 #3 - gdb processes stop for thread 2 and decides to re-resume
4934 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4935 thread 2 is now resumed, so the event should be ignored.
4937 IOW, if the stop for thread 2 doesn't end a foreground command,
4938 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4939 event. But it could be that the event meant that thread 2 itself
4940 (or whatever other thread was the last resumed thread) exited.
4942 To address this we refresh the thread list and check whether we
4943 have resumed threads _now_. In the example above, this removes
4944 thread 3 from the thread list. If thread 2 was re-resumed, we
4945 ignore this event. If we find no thread resumed, then we cancel
4946 the synchronous command and show "no unwaited-for " to the
4949 inferior
*curr_inf
= current_inferior ();
4951 scoped_restore_current_thread restore_thread
;
4953 for (auto *target
: all_non_exited_process_targets ())
4955 switch_to_target_no_thread (target
);
4956 update_thread_list ();
4961 - the current target has no thread executing, and
4962 - the current inferior is native, and
4963 - the current inferior is the one which has the terminal, and
4966 then a Ctrl-C from this point on would remain stuck in the
4967 kernel, until a thread resumes and dequeues it. That would
4968 result in the GDB CLI not reacting to Ctrl-C, not able to
4969 interrupt the program. To address this, if the current inferior
4970 no longer has any thread executing, we give the terminal to some
4971 other inferior that has at least one thread executing. */
4972 bool swap_terminal
= true;
4974 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4975 whether to report it to the user. */
4976 bool ignore_event
= false;
4978 for (thread_info
*thread
: all_non_exited_threads ())
4980 if (swap_terminal
&& thread
->executing
)
4982 if (thread
->inf
!= curr_inf
)
4984 target_terminal::ours ();
4986 switch_to_thread (thread
);
4987 target_terminal::inferior ();
4989 swap_terminal
= false;
4993 && (thread
->executing
4994 || thread
->suspend
.waitstatus_pending_p
))
4996 /* Either there were no unwaited-for children left in the
4997 target at some point, but there are now, or some target
4998 other than the eventing one has unwaited-for children
4999 left. Just ignore. */
5000 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
5001 "(ignoring: found resumed)");
5003 ignore_event
= true;
5006 if (ignore_event
&& !swap_terminal
)
5012 switch_to_inferior_no_thread (curr_inf
);
5013 prepare_to_wait (ecs
);
5017 /* Go ahead and report the event. */
5021 /* Given an execution control state that has been freshly filled in by
5022 an event from the inferior, figure out what it means and take
5025 The alternatives are:
5027 1) stop_waiting and return; to really stop and return to the
5030 2) keep_going and return; to wait for the next event (set
5031 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5035 handle_inferior_event (struct execution_control_state
*ecs
)
5037 /* Make sure that all temporary struct value objects that were
5038 created during the handling of the event get deleted at the
5040 scoped_value_mark free_values
;
5042 enum stop_kind stop_soon
;
5044 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5046 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5048 /* We had an event in the inferior, but we are not interested in
5049 handling it at this level. The lower layers have already
5050 done what needs to be done, if anything.
5052 One of the possible circumstances for this is when the
5053 inferior produces output for the console. The inferior has
5054 not stopped, and we are ignoring the event. Another possible
5055 circumstance is any event which the lower level knows will be
5056 reported multiple times without an intervening resume. */
5057 prepare_to_wait (ecs
);
5061 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5063 prepare_to_wait (ecs
);
5067 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5068 && handle_no_resumed (ecs
))
5071 /* Cache the last target/ptid/waitstatus. */
5072 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5074 /* Always clear state belonging to the previous time we stopped. */
5075 stop_stack_dummy
= STOP_NONE
;
5077 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5079 /* No unwaited-for children left. IOW, all resumed children
5081 stop_print_frame
= 0;
5086 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5087 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5089 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5090 /* If it's a new thread, add it to the thread database. */
5091 if (ecs
->event_thread
== NULL
)
5092 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5094 /* Disable range stepping. If the next step request could use a
5095 range, this will be end up re-enabled then. */
5096 ecs
->event_thread
->control
.may_range_step
= 0;
5099 /* Dependent on valid ECS->EVENT_THREAD. */
5100 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5102 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5103 reinit_frame_cache ();
5105 breakpoint_retire_moribund ();
5107 /* First, distinguish signals caused by the debugger from signals
5108 that have to do with the program's own actions. Note that
5109 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5110 on the operating system version. Here we detect when a SIGILL or
5111 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5112 something similar for SIGSEGV, since a SIGSEGV will be generated
5113 when we're trying to execute a breakpoint instruction on a
5114 non-executable stack. This happens for call dummy breakpoints
5115 for architectures like SPARC that place call dummies on the
5117 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5118 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5119 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5120 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5122 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5124 if (breakpoint_inserted_here_p (regcache
->aspace (),
5125 regcache_read_pc (regcache
)))
5127 infrun_debug_printf ("Treating signal as SIGTRAP");
5128 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5132 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5134 switch (ecs
->ws
.kind
)
5136 case TARGET_WAITKIND_LOADED
:
5137 context_switch (ecs
);
5138 /* Ignore gracefully during startup of the inferior, as it might
5139 be the shell which has just loaded some objects, otherwise
5140 add the symbols for the newly loaded objects. Also ignore at
5141 the beginning of an attach or remote session; we will query
5142 the full list of libraries once the connection is
5145 stop_soon
= get_inferior_stop_soon (ecs
);
5146 if (stop_soon
== NO_STOP_QUIETLY
)
5148 struct regcache
*regcache
;
5150 regcache
= get_thread_regcache (ecs
->event_thread
);
5152 handle_solib_event ();
5154 ecs
->event_thread
->control
.stop_bpstat
5155 = bpstat_stop_status (regcache
->aspace (),
5156 ecs
->event_thread
->suspend
.stop_pc
,
5157 ecs
->event_thread
, &ecs
->ws
);
5159 if (handle_stop_requested (ecs
))
5162 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5164 /* A catchpoint triggered. */
5165 process_event_stop_test (ecs
);
5169 /* If requested, stop when the dynamic linker notifies
5170 gdb of events. This allows the user to get control
5171 and place breakpoints in initializer routines for
5172 dynamically loaded objects (among other things). */
5173 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5174 if (stop_on_solib_events
)
5176 /* Make sure we print "Stopped due to solib-event" in
5178 stop_print_frame
= 1;
5185 /* If we are skipping through a shell, or through shared library
5186 loading that we aren't interested in, resume the program. If
5187 we're running the program normally, also resume. */
5188 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5190 /* Loading of shared libraries might have changed breakpoint
5191 addresses. Make sure new breakpoints are inserted. */
5192 if (stop_soon
== NO_STOP_QUIETLY
)
5193 insert_breakpoints ();
5194 resume (GDB_SIGNAL_0
);
5195 prepare_to_wait (ecs
);
5199 /* But stop if we're attaching or setting up a remote
5201 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5202 || stop_soon
== STOP_QUIETLY_REMOTE
)
5204 infrun_debug_printf ("quietly stopped");
5209 internal_error (__FILE__
, __LINE__
,
5210 _("unhandled stop_soon: %d"), (int) stop_soon
);
5212 case TARGET_WAITKIND_SPURIOUS
:
5213 if (handle_stop_requested (ecs
))
5215 context_switch (ecs
);
5216 resume (GDB_SIGNAL_0
);
5217 prepare_to_wait (ecs
);
5220 case TARGET_WAITKIND_THREAD_CREATED
:
5221 if (handle_stop_requested (ecs
))
5223 context_switch (ecs
);
5224 if (!switch_back_to_stepped_thread (ecs
))
5228 case TARGET_WAITKIND_EXITED
:
5229 case TARGET_WAITKIND_SIGNALLED
:
5231 /* Depending on the system, ecs->ptid may point to a thread or
5232 to a process. On some targets, target_mourn_inferior may
5233 need to have access to the just-exited thread. That is the
5234 case of GNU/Linux's "checkpoint" support, for example.
5235 Call the switch_to_xxx routine as appropriate. */
5236 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5238 switch_to_thread (thr
);
5241 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5242 switch_to_inferior_no_thread (inf
);
5245 handle_vfork_child_exec_or_exit (0);
5246 target_terminal::ours (); /* Must do this before mourn anyway. */
5248 /* Clearing any previous state of convenience variables. */
5249 clear_exit_convenience_vars ();
5251 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5253 /* Record the exit code in the convenience variable $_exitcode, so
5254 that the user can inspect this again later. */
5255 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5256 (LONGEST
) ecs
->ws
.value
.integer
);
5258 /* Also record this in the inferior itself. */
5259 current_inferior ()->has_exit_code
= 1;
5260 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5262 /* Support the --return-child-result option. */
5263 return_child_result_value
= ecs
->ws
.value
.integer
;
5265 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5269 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5271 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5273 /* Set the value of the internal variable $_exitsignal,
5274 which holds the signal uncaught by the inferior. */
5275 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5276 gdbarch_gdb_signal_to_target (gdbarch
,
5277 ecs
->ws
.value
.sig
));
5281 /* We don't have access to the target's method used for
5282 converting between signal numbers (GDB's internal
5283 representation <-> target's representation).
5284 Therefore, we cannot do a good job at displaying this
5285 information to the user. It's better to just warn
5286 her about it (if infrun debugging is enabled), and
5288 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5292 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5295 gdb_flush (gdb_stdout
);
5296 target_mourn_inferior (inferior_ptid
);
5297 stop_print_frame
= 0;
5301 case TARGET_WAITKIND_FORKED
:
5302 case TARGET_WAITKIND_VFORKED
:
5303 /* Check whether the inferior is displaced stepping. */
5305 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5306 struct gdbarch
*gdbarch
= regcache
->arch ();
5308 /* If checking displaced stepping is supported, and thread
5309 ecs->ptid is displaced stepping. */
5310 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5312 struct inferior
*parent_inf
5313 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5314 struct regcache
*child_regcache
;
5315 CORE_ADDR parent_pc
;
5317 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5319 struct displaced_step_inferior_state
*displaced
5320 = get_displaced_stepping_state (parent_inf
);
5322 /* Restore scratch pad for child process. */
5323 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5326 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5327 indicating that the displaced stepping of syscall instruction
5328 has been done. Perform cleanup for parent process here. Note
5329 that this operation also cleans up the child process for vfork,
5330 because their pages are shared. */
5331 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5332 /* Start a new step-over in another thread if there's one
5336 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5337 the child's PC is also within the scratchpad. Set the child's PC
5338 to the parent's PC value, which has already been fixed up.
5339 FIXME: we use the parent's aspace here, although we're touching
5340 the child, because the child hasn't been added to the inferior
5341 list yet at this point. */
5344 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5345 ecs
->ws
.value
.related_pid
,
5347 parent_inf
->aspace
);
5348 /* Read PC value of parent process. */
5349 parent_pc
= regcache_read_pc (regcache
);
5351 if (debug_displaced
)
5352 fprintf_unfiltered (gdb_stdlog
,
5353 "displaced: write child pc from %s to %s\n",
5355 regcache_read_pc (child_regcache
)),
5356 paddress (gdbarch
, parent_pc
));
5358 regcache_write_pc (child_regcache
, parent_pc
);
5362 context_switch (ecs
);
5364 /* Immediately detach breakpoints from the child before there's
5365 any chance of letting the user delete breakpoints from the
5366 breakpoint lists. If we don't do this early, it's easy to
5367 leave left over traps in the child, vis: "break foo; catch
5368 fork; c; <fork>; del; c; <child calls foo>". We only follow
5369 the fork on the last `continue', and by that time the
5370 breakpoint at "foo" is long gone from the breakpoint table.
5371 If we vforked, then we don't need to unpatch here, since both
5372 parent and child are sharing the same memory pages; we'll
5373 need to unpatch at follow/detach time instead to be certain
5374 that new breakpoints added between catchpoint hit time and
5375 vfork follow are detached. */
5376 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5378 /* This won't actually modify the breakpoint list, but will
5379 physically remove the breakpoints from the child. */
5380 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5383 delete_just_stopped_threads_single_step_breakpoints ();
5385 /* In case the event is caught by a catchpoint, remember that
5386 the event is to be followed at the next resume of the thread,
5387 and not immediately. */
5388 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5390 ecs
->event_thread
->suspend
.stop_pc
5391 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5393 ecs
->event_thread
->control
.stop_bpstat
5394 = bpstat_stop_status (get_current_regcache ()->aspace (),
5395 ecs
->event_thread
->suspend
.stop_pc
,
5396 ecs
->event_thread
, &ecs
->ws
);
5398 if (handle_stop_requested (ecs
))
5401 /* If no catchpoint triggered for this, then keep going. Note
5402 that we're interested in knowing the bpstat actually causes a
5403 stop, not just if it may explain the signal. Software
5404 watchpoints, for example, always appear in the bpstat. */
5405 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5408 = (follow_fork_mode_string
== follow_fork_mode_child
);
5410 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5412 process_stratum_target
*targ
5413 = ecs
->event_thread
->inf
->process_target ();
5415 bool should_resume
= follow_fork ();
5417 /* Note that one of these may be an invalid pointer,
5418 depending on detach_fork. */
5419 thread_info
*parent
= ecs
->event_thread
;
5421 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5423 /* At this point, the parent is marked running, and the
5424 child is marked stopped. */
5426 /* If not resuming the parent, mark it stopped. */
5427 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5428 parent
->set_running (false);
5430 /* If resuming the child, mark it running. */
5431 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5432 child
->set_running (true);
5434 /* In non-stop mode, also resume the other branch. */
5435 if (!detach_fork
&& (non_stop
5436 || (sched_multi
&& target_is_non_stop_p ())))
5439 switch_to_thread (parent
);
5441 switch_to_thread (child
);
5443 ecs
->event_thread
= inferior_thread ();
5444 ecs
->ptid
= inferior_ptid
;
5449 switch_to_thread (child
);
5451 switch_to_thread (parent
);
5453 ecs
->event_thread
= inferior_thread ();
5454 ecs
->ptid
= inferior_ptid
;
5462 process_event_stop_test (ecs
);
5465 case TARGET_WAITKIND_VFORK_DONE
:
5466 /* Done with the shared memory region. Re-insert breakpoints in
5467 the parent, and keep going. */
5469 context_switch (ecs
);
5471 current_inferior ()->waiting_for_vfork_done
= 0;
5472 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5474 if (handle_stop_requested (ecs
))
5477 /* This also takes care of reinserting breakpoints in the
5478 previously locked inferior. */
5482 case TARGET_WAITKIND_EXECD
:
5484 /* Note we can't read registers yet (the stop_pc), because we
5485 don't yet know the inferior's post-exec architecture.
5486 'stop_pc' is explicitly read below instead. */
5487 switch_to_thread_no_regs (ecs
->event_thread
);
5489 /* Do whatever is necessary to the parent branch of the vfork. */
5490 handle_vfork_child_exec_or_exit (1);
5492 /* This causes the eventpoints and symbol table to be reset.
5493 Must do this now, before trying to determine whether to
5495 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5497 /* In follow_exec we may have deleted the original thread and
5498 created a new one. Make sure that the event thread is the
5499 execd thread for that case (this is a nop otherwise). */
5500 ecs
->event_thread
= inferior_thread ();
5502 ecs
->event_thread
->suspend
.stop_pc
5503 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5505 ecs
->event_thread
->control
.stop_bpstat
5506 = bpstat_stop_status (get_current_regcache ()->aspace (),
5507 ecs
->event_thread
->suspend
.stop_pc
,
5508 ecs
->event_thread
, &ecs
->ws
);
5510 /* Note that this may be referenced from inside
5511 bpstat_stop_status above, through inferior_has_execd. */
5512 xfree (ecs
->ws
.value
.execd_pathname
);
5513 ecs
->ws
.value
.execd_pathname
= NULL
;
5515 if (handle_stop_requested (ecs
))
5518 /* If no catchpoint triggered for this, then keep going. */
5519 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5521 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5525 process_event_stop_test (ecs
);
5528 /* Be careful not to try to gather much state about a thread
5529 that's in a syscall. It's frequently a losing proposition. */
5530 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5531 /* Getting the current syscall number. */
5532 if (handle_syscall_event (ecs
) == 0)
5533 process_event_stop_test (ecs
);
5536 /* Before examining the threads further, step this thread to
5537 get it entirely out of the syscall. (We get notice of the
5538 event when the thread is just on the verge of exiting a
5539 syscall. Stepping one instruction seems to get it back
5541 case TARGET_WAITKIND_SYSCALL_RETURN
:
5542 if (handle_syscall_event (ecs
) == 0)
5543 process_event_stop_test (ecs
);
5546 case TARGET_WAITKIND_STOPPED
:
5547 handle_signal_stop (ecs
);
5550 case TARGET_WAITKIND_NO_HISTORY
:
5551 /* Reverse execution: target ran out of history info. */
5553 /* Switch to the stopped thread. */
5554 context_switch (ecs
);
5555 infrun_debug_printf ("stopped");
5557 delete_just_stopped_threads_single_step_breakpoints ();
5558 ecs
->event_thread
->suspend
.stop_pc
5559 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5561 if (handle_stop_requested (ecs
))
5564 gdb::observers::no_history
.notify ();
5570 /* Restart threads back to what they were trying to do back when we
5571 paused them for an in-line step-over. The EVENT_THREAD thread is
5575 restart_threads (struct thread_info
*event_thread
)
5577 /* In case the instruction just stepped spawned a new thread. */
5578 update_thread_list ();
5580 for (thread_info
*tp
: all_non_exited_threads ())
5582 switch_to_thread_no_regs (tp
);
5584 if (tp
== event_thread
)
5586 infrun_debug_printf ("restart threads: [%s] is event thread",
5587 target_pid_to_str (tp
->ptid
).c_str ());
5591 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5593 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5594 target_pid_to_str (tp
->ptid
).c_str ());
5600 infrun_debug_printf ("restart threads: [%s] resumed",
5601 target_pid_to_str (tp
->ptid
).c_str ());
5602 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5606 if (thread_is_in_step_over_chain (tp
))
5608 infrun_debug_printf ("restart threads: [%s] needs step-over",
5609 target_pid_to_str (tp
->ptid
).c_str ());
5610 gdb_assert (!tp
->resumed
);
5615 if (tp
->suspend
.waitstatus_pending_p
)
5617 infrun_debug_printf ("restart threads: [%s] has pending status",
5618 target_pid_to_str (tp
->ptid
).c_str ());
5623 gdb_assert (!tp
->stop_requested
);
5625 /* If some thread needs to start a step-over at this point, it
5626 should still be in the step-over queue, and thus skipped
5628 if (thread_still_needs_step_over (tp
))
5630 internal_error (__FILE__
, __LINE__
,
5631 "thread [%s] needs a step-over, but not in "
5632 "step-over queue\n",
5633 target_pid_to_str (tp
->ptid
).c_str ());
5636 if (currently_stepping (tp
))
5638 infrun_debug_printf ("restart threads: [%s] was stepping",
5639 target_pid_to_str (tp
->ptid
).c_str ());
5640 keep_going_stepped_thread (tp
);
5644 struct execution_control_state ecss
;
5645 struct execution_control_state
*ecs
= &ecss
;
5647 infrun_debug_printf ("restart threads: [%s] continuing",
5648 target_pid_to_str (tp
->ptid
).c_str ());
5649 reset_ecs (ecs
, tp
);
5650 switch_to_thread (tp
);
5651 keep_going_pass_signal (ecs
);
5656 /* Callback for iterate_over_threads. Find a resumed thread that has
5657 a pending waitstatus. */
5660 resumed_thread_with_pending_status (struct thread_info
*tp
,
5664 && tp
->suspend
.waitstatus_pending_p
);
5667 /* Called when we get an event that may finish an in-line or
5668 out-of-line (displaced stepping) step-over started previously.
5669 Return true if the event is processed and we should go back to the
5670 event loop; false if the caller should continue processing the
5674 finish_step_over (struct execution_control_state
*ecs
)
5676 int had_step_over_info
;
5678 displaced_step_fixup (ecs
->event_thread
,
5679 ecs
->event_thread
->suspend
.stop_signal
);
5681 had_step_over_info
= step_over_info_valid_p ();
5683 if (had_step_over_info
)
5685 /* If we're stepping over a breakpoint with all threads locked,
5686 then only the thread that was stepped should be reporting
5688 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5690 clear_step_over_info ();
5693 if (!target_is_non_stop_p ())
5696 /* Start a new step-over in another thread if there's one that
5700 /* If we were stepping over a breakpoint before, and haven't started
5701 a new in-line step-over sequence, then restart all other threads
5702 (except the event thread). We can't do this in all-stop, as then
5703 e.g., we wouldn't be able to issue any other remote packet until
5704 these other threads stop. */
5705 if (had_step_over_info
&& !step_over_info_valid_p ())
5707 struct thread_info
*pending
;
5709 /* If we only have threads with pending statuses, the restart
5710 below won't restart any thread and so nothing re-inserts the
5711 breakpoint we just stepped over. But we need it inserted
5712 when we later process the pending events, otherwise if
5713 another thread has a pending event for this breakpoint too,
5714 we'd discard its event (because the breakpoint that
5715 originally caused the event was no longer inserted). */
5716 context_switch (ecs
);
5717 insert_breakpoints ();
5719 restart_threads (ecs
->event_thread
);
5721 /* If we have events pending, go through handle_inferior_event
5722 again, picking up a pending event at random. This avoids
5723 thread starvation. */
5725 /* But not if we just stepped over a watchpoint in order to let
5726 the instruction execute so we can evaluate its expression.
5727 The set of watchpoints that triggered is recorded in the
5728 breakpoint objects themselves (see bp->watchpoint_triggered).
5729 If we processed another event first, that other event could
5730 clobber this info. */
5731 if (ecs
->event_thread
->stepping_over_watchpoint
)
5734 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5736 if (pending
!= NULL
)
5738 struct thread_info
*tp
= ecs
->event_thread
;
5739 struct regcache
*regcache
;
5741 infrun_debug_printf ("found resumed threads with "
5742 "pending events, saving status");
5744 gdb_assert (pending
!= tp
);
5746 /* Record the event thread's event for later. */
5747 save_waitstatus (tp
, &ecs
->ws
);
5748 /* This was cleared early, by handle_inferior_event. Set it
5749 so this pending event is considered by
5753 gdb_assert (!tp
->executing
);
5755 regcache
= get_thread_regcache (tp
);
5756 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5758 infrun_debug_printf ("saved stop_pc=%s for %s "
5759 "(currently_stepping=%d)",
5760 paddress (target_gdbarch (),
5761 tp
->suspend
.stop_pc
),
5762 target_pid_to_str (tp
->ptid
).c_str (),
5763 currently_stepping (tp
));
5765 /* This in-line step-over finished; clear this so we won't
5766 start a new one. This is what handle_signal_stop would
5767 do, if we returned false. */
5768 tp
->stepping_over_breakpoint
= 0;
5770 /* Wake up the event loop again. */
5771 mark_async_event_handler (infrun_async_inferior_event_token
);
5773 prepare_to_wait (ecs
);
5781 /* Come here when the program has stopped with a signal. */
5784 handle_signal_stop (struct execution_control_state
*ecs
)
5786 struct frame_info
*frame
;
5787 struct gdbarch
*gdbarch
;
5788 int stopped_by_watchpoint
;
5789 enum stop_kind stop_soon
;
5792 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5794 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5796 /* Do we need to clean up the state of a thread that has
5797 completed a displaced single-step? (Doing so usually affects
5798 the PC, so do it here, before we set stop_pc.) */
5799 if (finish_step_over (ecs
))
5802 /* If we either finished a single-step or hit a breakpoint, but
5803 the user wanted this thread to be stopped, pretend we got a
5804 SIG0 (generic unsignaled stop). */
5805 if (ecs
->event_thread
->stop_requested
5806 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5807 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5809 ecs
->event_thread
->suspend
.stop_pc
5810 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5814 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5815 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5817 switch_to_thread (ecs
->event_thread
);
5819 infrun_debug_printf ("stop_pc=%s",
5820 paddress (reg_gdbarch
,
5821 ecs
->event_thread
->suspend
.stop_pc
));
5822 if (target_stopped_by_watchpoint ())
5826 infrun_debug_printf ("stopped by watchpoint");
5828 if (target_stopped_data_address (current_top_target (), &addr
))
5829 infrun_debug_printf ("stopped data address=%s",
5830 paddress (reg_gdbarch
, addr
));
5832 infrun_debug_printf ("(no data address available)");
5836 /* This is originated from start_remote(), start_inferior() and
5837 shared libraries hook functions. */
5838 stop_soon
= get_inferior_stop_soon (ecs
);
5839 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5841 context_switch (ecs
);
5842 infrun_debug_printf ("quietly stopped");
5843 stop_print_frame
= 1;
5848 /* This originates from attach_command(). We need to overwrite
5849 the stop_signal here, because some kernels don't ignore a
5850 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5851 See more comments in inferior.h. On the other hand, if we
5852 get a non-SIGSTOP, report it to the user - assume the backend
5853 will handle the SIGSTOP if it should show up later.
5855 Also consider that the attach is complete when we see a
5856 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5857 target extended-remote report it instead of a SIGSTOP
5858 (e.g. gdbserver). We already rely on SIGTRAP being our
5859 signal, so this is no exception.
5861 Also consider that the attach is complete when we see a
5862 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5863 the target to stop all threads of the inferior, in case the
5864 low level attach operation doesn't stop them implicitly. If
5865 they weren't stopped implicitly, then the stub will report a
5866 GDB_SIGNAL_0, meaning: stopped for no particular reason
5867 other than GDB's request. */
5868 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5869 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5870 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5871 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5873 stop_print_frame
= 1;
5875 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5879 /* See if something interesting happened to the non-current thread. If
5880 so, then switch to that thread. */
5881 if (ecs
->ptid
!= inferior_ptid
)
5883 infrun_debug_printf ("context switch");
5885 context_switch (ecs
);
5887 if (deprecated_context_hook
)
5888 deprecated_context_hook (ecs
->event_thread
->global_num
);
5891 /* At this point, get hold of the now-current thread's frame. */
5892 frame
= get_current_frame ();
5893 gdbarch
= get_frame_arch (frame
);
5895 /* Pull the single step breakpoints out of the target. */
5896 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5898 struct regcache
*regcache
;
5901 regcache
= get_thread_regcache (ecs
->event_thread
);
5902 const address_space
*aspace
= regcache
->aspace ();
5904 pc
= regcache_read_pc (regcache
);
5906 /* However, before doing so, if this single-step breakpoint was
5907 actually for another thread, set this thread up for moving
5909 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5912 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5914 infrun_debug_printf ("[%s] hit another thread's single-step "
5916 target_pid_to_str (ecs
->ptid
).c_str ());
5917 ecs
->hit_singlestep_breakpoint
= 1;
5922 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5923 target_pid_to_str (ecs
->ptid
).c_str ());
5926 delete_just_stopped_threads_single_step_breakpoints ();
5928 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5929 && ecs
->event_thread
->control
.trap_expected
5930 && ecs
->event_thread
->stepping_over_watchpoint
)
5931 stopped_by_watchpoint
= 0;
5933 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5935 /* If necessary, step over this watchpoint. We'll be back to display
5937 if (stopped_by_watchpoint
5938 && (target_have_steppable_watchpoint
5939 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5941 /* At this point, we are stopped at an instruction which has
5942 attempted to write to a piece of memory under control of
5943 a watchpoint. The instruction hasn't actually executed
5944 yet. If we were to evaluate the watchpoint expression
5945 now, we would get the old value, and therefore no change
5946 would seem to have occurred.
5948 In order to make watchpoints work `right', we really need
5949 to complete the memory write, and then evaluate the
5950 watchpoint expression. We do this by single-stepping the
5953 It may not be necessary to disable the watchpoint to step over
5954 it. For example, the PA can (with some kernel cooperation)
5955 single step over a watchpoint without disabling the watchpoint.
5957 It is far more common to need to disable a watchpoint to step
5958 the inferior over it. If we have non-steppable watchpoints,
5959 we must disable the current watchpoint; it's simplest to
5960 disable all watchpoints.
5962 Any breakpoint at PC must also be stepped over -- if there's
5963 one, it will have already triggered before the watchpoint
5964 triggered, and we either already reported it to the user, or
5965 it didn't cause a stop and we called keep_going. In either
5966 case, if there was a breakpoint at PC, we must be trying to
5968 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5973 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5974 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5975 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5976 ecs
->event_thread
->control
.stop_step
= 0;
5977 stop_print_frame
= 1;
5978 stopped_by_random_signal
= 0;
5979 bpstat stop_chain
= NULL
;
5981 /* Hide inlined functions starting here, unless we just performed stepi or
5982 nexti. After stepi and nexti, always show the innermost frame (not any
5983 inline function call sites). */
5984 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5986 const address_space
*aspace
5987 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5989 /* skip_inline_frames is expensive, so we avoid it if we can
5990 determine that the address is one where functions cannot have
5991 been inlined. This improves performance with inferiors that
5992 load a lot of shared libraries, because the solib event
5993 breakpoint is defined as the address of a function (i.e. not
5994 inline). Note that we have to check the previous PC as well
5995 as the current one to catch cases when we have just
5996 single-stepped off a breakpoint prior to reinstating it.
5997 Note that we're assuming that the code we single-step to is
5998 not inline, but that's not definitive: there's nothing
5999 preventing the event breakpoint function from containing
6000 inlined code, and the single-step ending up there. If the
6001 user had set a breakpoint on that inlined code, the missing
6002 skip_inline_frames call would break things. Fortunately
6003 that's an extremely unlikely scenario. */
6004 if (!pc_at_non_inline_function (aspace
,
6005 ecs
->event_thread
->suspend
.stop_pc
,
6007 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6008 && ecs
->event_thread
->control
.trap_expected
6009 && pc_at_non_inline_function (aspace
,
6010 ecs
->event_thread
->prev_pc
,
6013 stop_chain
= build_bpstat_chain (aspace
,
6014 ecs
->event_thread
->suspend
.stop_pc
,
6016 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6018 /* Re-fetch current thread's frame in case that invalidated
6020 frame
= get_current_frame ();
6021 gdbarch
= get_frame_arch (frame
);
6025 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6026 && ecs
->event_thread
->control
.trap_expected
6027 && gdbarch_single_step_through_delay_p (gdbarch
)
6028 && currently_stepping (ecs
->event_thread
))
6030 /* We're trying to step off a breakpoint. Turns out that we're
6031 also on an instruction that needs to be stepped multiple
6032 times before it's been fully executing. E.g., architectures
6033 with a delay slot. It needs to be stepped twice, once for
6034 the instruction and once for the delay slot. */
6035 int step_through_delay
6036 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6038 if (step_through_delay
)
6039 infrun_debug_printf ("step through delay");
6041 if (ecs
->event_thread
->control
.step_range_end
== 0
6042 && step_through_delay
)
6044 /* The user issued a continue when stopped at a breakpoint.
6045 Set up for another trap and get out of here. */
6046 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6050 else if (step_through_delay
)
6052 /* The user issued a step when stopped at a breakpoint.
6053 Maybe we should stop, maybe we should not - the delay
6054 slot *might* correspond to a line of source. In any
6055 case, don't decide that here, just set
6056 ecs->stepping_over_breakpoint, making sure we
6057 single-step again before breakpoints are re-inserted. */
6058 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6062 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6063 handles this event. */
6064 ecs
->event_thread
->control
.stop_bpstat
6065 = bpstat_stop_status (get_current_regcache ()->aspace (),
6066 ecs
->event_thread
->suspend
.stop_pc
,
6067 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6069 /* Following in case break condition called a
6071 stop_print_frame
= 1;
6073 /* This is where we handle "moribund" watchpoints. Unlike
6074 software breakpoints traps, hardware watchpoint traps are
6075 always distinguishable from random traps. If no high-level
6076 watchpoint is associated with the reported stop data address
6077 anymore, then the bpstat does not explain the signal ---
6078 simply make sure to ignore it if `stopped_by_watchpoint' is
6081 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6082 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6084 && stopped_by_watchpoint
)
6086 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6090 /* NOTE: cagney/2003-03-29: These checks for a random signal
6091 at one stage in the past included checks for an inferior
6092 function call's call dummy's return breakpoint. The original
6093 comment, that went with the test, read:
6095 ``End of a stack dummy. Some systems (e.g. Sony news) give
6096 another signal besides SIGTRAP, so check here as well as
6099 If someone ever tries to get call dummys on a
6100 non-executable stack to work (where the target would stop
6101 with something like a SIGSEGV), then those tests might need
6102 to be re-instated. Given, however, that the tests were only
6103 enabled when momentary breakpoints were not being used, I
6104 suspect that it won't be the case.
6106 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6107 be necessary for call dummies on a non-executable stack on
6110 /* See if the breakpoints module can explain the signal. */
6112 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6113 ecs
->event_thread
->suspend
.stop_signal
);
6115 /* Maybe this was a trap for a software breakpoint that has since
6117 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6119 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6120 ecs
->event_thread
->suspend
.stop_pc
))
6122 struct regcache
*regcache
;
6125 /* Re-adjust PC to what the program would see if GDB was not
6127 regcache
= get_thread_regcache (ecs
->event_thread
);
6128 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6131 gdb::optional
<scoped_restore_tmpl
<int>>
6132 restore_operation_disable
;
6134 if (record_full_is_used ())
6135 restore_operation_disable
.emplace
6136 (record_full_gdb_operation_disable_set ());
6138 regcache_write_pc (regcache
,
6139 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6144 /* A delayed software breakpoint event. Ignore the trap. */
6145 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6150 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6151 has since been removed. */
6152 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6154 /* A delayed hardware breakpoint event. Ignore the trap. */
6155 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6160 /* If not, perhaps stepping/nexting can. */
6162 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6163 && currently_stepping (ecs
->event_thread
));
6165 /* Perhaps the thread hit a single-step breakpoint of _another_
6166 thread. Single-step breakpoints are transparent to the
6167 breakpoints module. */
6169 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6171 /* No? Perhaps we got a moribund watchpoint. */
6173 random_signal
= !stopped_by_watchpoint
;
6175 /* Always stop if the user explicitly requested this thread to
6177 if (ecs
->event_thread
->stop_requested
)
6180 infrun_debug_printf ("user-requested stop");
6183 /* For the program's own signals, act according to
6184 the signal handling tables. */
6188 /* Signal not for debugging purposes. */
6189 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6190 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6192 infrun_debug_printf ("random signal (%s)",
6193 gdb_signal_to_symbol_string (stop_signal
));
6195 stopped_by_random_signal
= 1;
6197 /* Always stop on signals if we're either just gaining control
6198 of the program, or the user explicitly requested this thread
6199 to remain stopped. */
6200 if (stop_soon
!= NO_STOP_QUIETLY
6201 || ecs
->event_thread
->stop_requested
6203 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6209 /* Notify observers the signal has "handle print" set. Note we
6210 returned early above if stopping; normal_stop handles the
6211 printing in that case. */
6212 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6214 /* The signal table tells us to print about this signal. */
6215 target_terminal::ours_for_output ();
6216 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6217 target_terminal::inferior ();
6220 /* Clear the signal if it should not be passed. */
6221 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6222 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6224 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6225 && ecs
->event_thread
->control
.trap_expected
6226 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6228 /* We were just starting a new sequence, attempting to
6229 single-step off of a breakpoint and expecting a SIGTRAP.
6230 Instead this signal arrives. This signal will take us out
6231 of the stepping range so GDB needs to remember to, when
6232 the signal handler returns, resume stepping off that
6234 /* To simplify things, "continue" is forced to use the same
6235 code paths as single-step - set a breakpoint at the
6236 signal return address and then, once hit, step off that
6238 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6240 insert_hp_step_resume_breakpoint_at_frame (frame
);
6241 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6242 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6243 ecs
->event_thread
->control
.trap_expected
= 0;
6245 /* If we were nexting/stepping some other thread, switch to
6246 it, so that we don't continue it, losing control. */
6247 if (!switch_back_to_stepped_thread (ecs
))
6252 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6253 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6255 || ecs
->event_thread
->control
.step_range_end
== 1)
6256 && frame_id_eq (get_stack_frame_id (frame
),
6257 ecs
->event_thread
->control
.step_stack_frame_id
)
6258 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6260 /* The inferior is about to take a signal that will take it
6261 out of the single step range. Set a breakpoint at the
6262 current PC (which is presumably where the signal handler
6263 will eventually return) and then allow the inferior to
6266 Note that this is only needed for a signal delivered
6267 while in the single-step range. Nested signals aren't a
6268 problem as they eventually all return. */
6269 infrun_debug_printf ("signal may take us out of single-step range");
6271 clear_step_over_info ();
6272 insert_hp_step_resume_breakpoint_at_frame (frame
);
6273 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6274 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6275 ecs
->event_thread
->control
.trap_expected
= 0;
6280 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6281 when either there's a nested signal, or when there's a
6282 pending signal enabled just as the signal handler returns
6283 (leaving the inferior at the step-resume-breakpoint without
6284 actually executing it). Either way continue until the
6285 breakpoint is really hit. */
6287 if (!switch_back_to_stepped_thread (ecs
))
6289 infrun_debug_printf ("random signal, keep going");
6296 process_event_stop_test (ecs
);
6299 /* Come here when we've got some debug event / signal we can explain
6300 (IOW, not a random signal), and test whether it should cause a
6301 stop, or whether we should resume the inferior (transparently).
6302 E.g., could be a breakpoint whose condition evaluates false; we
6303 could be still stepping within the line; etc. */
6306 process_event_stop_test (struct execution_control_state
*ecs
)
6308 struct symtab_and_line stop_pc_sal
;
6309 struct frame_info
*frame
;
6310 struct gdbarch
*gdbarch
;
6311 CORE_ADDR jmp_buf_pc
;
6312 struct bpstat_what what
;
6314 /* Handle cases caused by hitting a breakpoint. */
6316 frame
= get_current_frame ();
6317 gdbarch
= get_frame_arch (frame
);
6319 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6321 if (what
.call_dummy
)
6323 stop_stack_dummy
= what
.call_dummy
;
6326 /* A few breakpoint types have callbacks associated (e.g.,
6327 bp_jit_event). Run them now. */
6328 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6330 /* If we hit an internal event that triggers symbol changes, the
6331 current frame will be invalidated within bpstat_what (e.g., if we
6332 hit an internal solib event). Re-fetch it. */
6333 frame
= get_current_frame ();
6334 gdbarch
= get_frame_arch (frame
);
6336 switch (what
.main_action
)
6338 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6339 /* If we hit the breakpoint at longjmp while stepping, we
6340 install a momentary breakpoint at the target of the
6343 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6345 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6347 if (what
.is_longjmp
)
6349 struct value
*arg_value
;
6351 /* If we set the longjmp breakpoint via a SystemTap probe,
6352 then use it to extract the arguments. The destination PC
6353 is the third argument to the probe. */
6354 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6357 jmp_buf_pc
= value_as_address (arg_value
);
6358 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6360 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6361 || !gdbarch_get_longjmp_target (gdbarch
,
6362 frame
, &jmp_buf_pc
))
6364 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6365 "(!gdbarch_get_longjmp_target)");
6370 /* Insert a breakpoint at resume address. */
6371 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6374 check_exception_resume (ecs
, frame
);
6378 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6380 struct frame_info
*init_frame
;
6382 /* There are several cases to consider.
6384 1. The initiating frame no longer exists. In this case we
6385 must stop, because the exception or longjmp has gone too
6388 2. The initiating frame exists, and is the same as the
6389 current frame. We stop, because the exception or longjmp
6392 3. The initiating frame exists and is different from the
6393 current frame. This means the exception or longjmp has
6394 been caught beneath the initiating frame, so keep going.
6396 4. longjmp breakpoint has been placed just to protect
6397 against stale dummy frames and user is not interested in
6398 stopping around longjmps. */
6400 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6402 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6404 delete_exception_resume_breakpoint (ecs
->event_thread
);
6406 if (what
.is_longjmp
)
6408 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6410 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6418 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6422 struct frame_id current_id
6423 = get_frame_id (get_current_frame ());
6424 if (frame_id_eq (current_id
,
6425 ecs
->event_thread
->initiating_frame
))
6427 /* Case 2. Fall through. */
6437 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6439 delete_step_resume_breakpoint (ecs
->event_thread
);
6441 end_stepping_range (ecs
);
6445 case BPSTAT_WHAT_SINGLE
:
6446 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6447 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6448 /* Still need to check other stuff, at least the case where we
6449 are stepping and step out of the right range. */
6452 case BPSTAT_WHAT_STEP_RESUME
:
6453 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6455 delete_step_resume_breakpoint (ecs
->event_thread
);
6456 if (ecs
->event_thread
->control
.proceed_to_finish
6457 && execution_direction
== EXEC_REVERSE
)
6459 struct thread_info
*tp
= ecs
->event_thread
;
6461 /* We are finishing a function in reverse, and just hit the
6462 step-resume breakpoint at the start address of the
6463 function, and we're almost there -- just need to back up
6464 by one more single-step, which should take us back to the
6466 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6470 fill_in_stop_func (gdbarch
, ecs
);
6471 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6472 && execution_direction
== EXEC_REVERSE
)
6474 /* We are stepping over a function call in reverse, and just
6475 hit the step-resume breakpoint at the start address of
6476 the function. Go back to single-stepping, which should
6477 take us back to the function call. */
6478 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6484 case BPSTAT_WHAT_STOP_NOISY
:
6485 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6486 stop_print_frame
= 1;
6488 /* Assume the thread stopped for a breakpoint. We'll still check
6489 whether a/the breakpoint is there when the thread is next
6491 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6496 case BPSTAT_WHAT_STOP_SILENT
:
6497 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6498 stop_print_frame
= 0;
6500 /* Assume the thread stopped for a breakpoint. We'll still check
6501 whether a/the breakpoint is there when the thread is next
6503 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6507 case BPSTAT_WHAT_HP_STEP_RESUME
:
6508 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6510 delete_step_resume_breakpoint (ecs
->event_thread
);
6511 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6513 /* Back when the step-resume breakpoint was inserted, we
6514 were trying to single-step off a breakpoint. Go back to
6516 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6517 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6523 case BPSTAT_WHAT_KEEP_CHECKING
:
6527 /* If we stepped a permanent breakpoint and we had a high priority
6528 step-resume breakpoint for the address we stepped, but we didn't
6529 hit it, then we must have stepped into the signal handler. The
6530 step-resume was only necessary to catch the case of _not_
6531 stepping into the handler, so delete it, and fall through to
6532 checking whether the step finished. */
6533 if (ecs
->event_thread
->stepped_breakpoint
)
6535 struct breakpoint
*sr_bp
6536 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6539 && sr_bp
->loc
->permanent
6540 && sr_bp
->type
== bp_hp_step_resume
6541 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6543 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6544 delete_step_resume_breakpoint (ecs
->event_thread
);
6545 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6549 /* We come here if we hit a breakpoint but should not stop for it.
6550 Possibly we also were stepping and should stop for that. So fall
6551 through and test for stepping. But, if not stepping, do not
6554 /* In all-stop mode, if we're currently stepping but have stopped in
6555 some other thread, we need to switch back to the stepped thread. */
6556 if (switch_back_to_stepped_thread (ecs
))
6559 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6561 infrun_debug_printf ("step-resume breakpoint is inserted");
6563 /* Having a step-resume breakpoint overrides anything
6564 else having to do with stepping commands until
6565 that breakpoint is reached. */
6570 if (ecs
->event_thread
->control
.step_range_end
== 0)
6572 infrun_debug_printf ("no stepping, continue");
6573 /* Likewise if we aren't even stepping. */
6578 /* Re-fetch current thread's frame in case the code above caused
6579 the frame cache to be re-initialized, making our FRAME variable
6580 a dangling pointer. */
6581 frame
= get_current_frame ();
6582 gdbarch
= get_frame_arch (frame
);
6583 fill_in_stop_func (gdbarch
, ecs
);
6585 /* If stepping through a line, keep going if still within it.
6587 Note that step_range_end is the address of the first instruction
6588 beyond the step range, and NOT the address of the last instruction
6591 Note also that during reverse execution, we may be stepping
6592 through a function epilogue and therefore must detect when
6593 the current-frame changes in the middle of a line. */
6595 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6597 && (execution_direction
!= EXEC_REVERSE
6598 || frame_id_eq (get_frame_id (frame
),
6599 ecs
->event_thread
->control
.step_frame_id
)))
6602 ("stepping inside range [%s-%s]",
6603 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6604 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6606 /* Tentatively re-enable range stepping; `resume' disables it if
6607 necessary (e.g., if we're stepping over a breakpoint or we
6608 have software watchpoints). */
6609 ecs
->event_thread
->control
.may_range_step
= 1;
6611 /* When stepping backward, stop at beginning of line range
6612 (unless it's the function entry point, in which case
6613 keep going back to the call point). */
6614 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6615 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6616 && stop_pc
!= ecs
->stop_func_start
6617 && execution_direction
== EXEC_REVERSE
)
6618 end_stepping_range (ecs
);
6625 /* We stepped out of the stepping range. */
6627 /* If we are stepping at the source level and entered the runtime
6628 loader dynamic symbol resolution code...
6630 EXEC_FORWARD: we keep on single stepping until we exit the run
6631 time loader code and reach the callee's address.
6633 EXEC_REVERSE: we've already executed the callee (backward), and
6634 the runtime loader code is handled just like any other
6635 undebuggable function call. Now we need only keep stepping
6636 backward through the trampoline code, and that's handled further
6637 down, so there is nothing for us to do here. */
6639 if (execution_direction
!= EXEC_REVERSE
6640 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6641 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6643 CORE_ADDR pc_after_resolver
=
6644 gdbarch_skip_solib_resolver (gdbarch
,
6645 ecs
->event_thread
->suspend
.stop_pc
);
6647 infrun_debug_printf ("stepped into dynsym resolve code");
6649 if (pc_after_resolver
)
6651 /* Set up a step-resume breakpoint at the address
6652 indicated by SKIP_SOLIB_RESOLVER. */
6653 symtab_and_line sr_sal
;
6654 sr_sal
.pc
= pc_after_resolver
;
6655 sr_sal
.pspace
= get_frame_program_space (frame
);
6657 insert_step_resume_breakpoint_at_sal (gdbarch
,
6658 sr_sal
, null_frame_id
);
6665 /* Step through an indirect branch thunk. */
6666 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6667 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6668 ecs
->event_thread
->suspend
.stop_pc
))
6670 infrun_debug_printf ("stepped into indirect branch thunk");
6675 if (ecs
->event_thread
->control
.step_range_end
!= 1
6676 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6677 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6678 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6680 infrun_debug_printf ("stepped into signal trampoline");
6681 /* The inferior, while doing a "step" or "next", has ended up in
6682 a signal trampoline (either by a signal being delivered or by
6683 the signal handler returning). Just single-step until the
6684 inferior leaves the trampoline (either by calling the handler
6690 /* If we're in the return path from a shared library trampoline,
6691 we want to proceed through the trampoline when stepping. */
6692 /* macro/2012-04-25: This needs to come before the subroutine
6693 call check below as on some targets return trampolines look
6694 like subroutine calls (MIPS16 return thunks). */
6695 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6696 ecs
->event_thread
->suspend
.stop_pc
,
6697 ecs
->stop_func_name
)
6698 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6700 /* Determine where this trampoline returns. */
6701 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6702 CORE_ADDR real_stop_pc
6703 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6705 infrun_debug_printf ("stepped into solib return tramp");
6707 /* Only proceed through if we know where it's going. */
6710 /* And put the step-breakpoint there and go until there. */
6711 symtab_and_line sr_sal
;
6712 sr_sal
.pc
= real_stop_pc
;
6713 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6714 sr_sal
.pspace
= get_frame_program_space (frame
);
6716 /* Do not specify what the fp should be when we stop since
6717 on some machines the prologue is where the new fp value
6719 insert_step_resume_breakpoint_at_sal (gdbarch
,
6720 sr_sal
, null_frame_id
);
6722 /* Restart without fiddling with the step ranges or
6729 /* Check for subroutine calls. The check for the current frame
6730 equalling the step ID is not necessary - the check of the
6731 previous frame's ID is sufficient - but it is a common case and
6732 cheaper than checking the previous frame's ID.
6734 NOTE: frame_id_eq will never report two invalid frame IDs as
6735 being equal, so to get into this block, both the current and
6736 previous frame must have valid frame IDs. */
6737 /* The outer_frame_id check is a heuristic to detect stepping
6738 through startup code. If we step over an instruction which
6739 sets the stack pointer from an invalid value to a valid value,
6740 we may detect that as a subroutine call from the mythical
6741 "outermost" function. This could be fixed by marking
6742 outermost frames as !stack_p,code_p,special_p. Then the
6743 initial outermost frame, before sp was valid, would
6744 have code_addr == &_start. See the comment in frame_id_eq
6746 if (!frame_id_eq (get_stack_frame_id (frame
),
6747 ecs
->event_thread
->control
.step_stack_frame_id
)
6748 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6749 ecs
->event_thread
->control
.step_stack_frame_id
)
6750 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6752 || (ecs
->event_thread
->control
.step_start_function
6753 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6755 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6756 CORE_ADDR real_stop_pc
;
6758 infrun_debug_printf ("stepped into subroutine");
6760 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6762 /* I presume that step_over_calls is only 0 when we're
6763 supposed to be stepping at the assembly language level
6764 ("stepi"). Just stop. */
6765 /* And this works the same backward as frontward. MVS */
6766 end_stepping_range (ecs
);
6770 /* Reverse stepping through solib trampolines. */
6772 if (execution_direction
== EXEC_REVERSE
6773 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6774 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6775 || (ecs
->stop_func_start
== 0
6776 && in_solib_dynsym_resolve_code (stop_pc
))))
6778 /* Any solib trampoline code can be handled in reverse
6779 by simply continuing to single-step. We have already
6780 executed the solib function (backwards), and a few
6781 steps will take us back through the trampoline to the
6787 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6789 /* We're doing a "next".
6791 Normal (forward) execution: set a breakpoint at the
6792 callee's return address (the address at which the caller
6795 Reverse (backward) execution. set the step-resume
6796 breakpoint at the start of the function that we just
6797 stepped into (backwards), and continue to there. When we
6798 get there, we'll need to single-step back to the caller. */
6800 if (execution_direction
== EXEC_REVERSE
)
6802 /* If we're already at the start of the function, we've either
6803 just stepped backward into a single instruction function,
6804 or stepped back out of a signal handler to the first instruction
6805 of the function. Just keep going, which will single-step back
6807 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6809 /* Normal function call return (static or dynamic). */
6810 symtab_and_line sr_sal
;
6811 sr_sal
.pc
= ecs
->stop_func_start
;
6812 sr_sal
.pspace
= get_frame_program_space (frame
);
6813 insert_step_resume_breakpoint_at_sal (gdbarch
,
6814 sr_sal
, null_frame_id
);
6818 insert_step_resume_breakpoint_at_caller (frame
);
6824 /* If we are in a function call trampoline (a stub between the
6825 calling routine and the real function), locate the real
6826 function. That's what tells us (a) whether we want to step
6827 into it at all, and (b) what prologue we want to run to the
6828 end of, if we do step into it. */
6829 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6830 if (real_stop_pc
== 0)
6831 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6832 if (real_stop_pc
!= 0)
6833 ecs
->stop_func_start
= real_stop_pc
;
6835 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6837 symtab_and_line sr_sal
;
6838 sr_sal
.pc
= ecs
->stop_func_start
;
6839 sr_sal
.pspace
= get_frame_program_space (frame
);
6841 insert_step_resume_breakpoint_at_sal (gdbarch
,
6842 sr_sal
, null_frame_id
);
6847 /* If we have line number information for the function we are
6848 thinking of stepping into and the function isn't on the skip
6851 If there are several symtabs at that PC (e.g. with include
6852 files), just want to know whether *any* of them have line
6853 numbers. find_pc_line handles this. */
6855 struct symtab_and_line tmp_sal
;
6857 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6858 if (tmp_sal
.line
!= 0
6859 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6861 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6863 if (execution_direction
== EXEC_REVERSE
)
6864 handle_step_into_function_backward (gdbarch
, ecs
);
6866 handle_step_into_function (gdbarch
, ecs
);
6871 /* If we have no line number and the step-stop-if-no-debug is
6872 set, we stop the step so that the user has a chance to switch
6873 in assembly mode. */
6874 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6875 && step_stop_if_no_debug
)
6877 end_stepping_range (ecs
);
6881 if (execution_direction
== EXEC_REVERSE
)
6883 /* If we're already at the start of the function, we've either just
6884 stepped backward into a single instruction function without line
6885 number info, or stepped back out of a signal handler to the first
6886 instruction of the function without line number info. Just keep
6887 going, which will single-step back to the caller. */
6888 if (ecs
->stop_func_start
!= stop_pc
)
6890 /* Set a breakpoint at callee's start address.
6891 From there we can step once and be back in the caller. */
6892 symtab_and_line sr_sal
;
6893 sr_sal
.pc
= ecs
->stop_func_start
;
6894 sr_sal
.pspace
= get_frame_program_space (frame
);
6895 insert_step_resume_breakpoint_at_sal (gdbarch
,
6896 sr_sal
, null_frame_id
);
6900 /* Set a breakpoint at callee's return address (the address
6901 at which the caller will resume). */
6902 insert_step_resume_breakpoint_at_caller (frame
);
6908 /* Reverse stepping through solib trampolines. */
6910 if (execution_direction
== EXEC_REVERSE
6911 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6913 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6915 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6916 || (ecs
->stop_func_start
== 0
6917 && in_solib_dynsym_resolve_code (stop_pc
)))
6919 /* Any solib trampoline code can be handled in reverse
6920 by simply continuing to single-step. We have already
6921 executed the solib function (backwards), and a few
6922 steps will take us back through the trampoline to the
6927 else if (in_solib_dynsym_resolve_code (stop_pc
))
6929 /* Stepped backward into the solib dynsym resolver.
6930 Set a breakpoint at its start and continue, then
6931 one more step will take us out. */
6932 symtab_and_line sr_sal
;
6933 sr_sal
.pc
= ecs
->stop_func_start
;
6934 sr_sal
.pspace
= get_frame_program_space (frame
);
6935 insert_step_resume_breakpoint_at_sal (gdbarch
,
6936 sr_sal
, null_frame_id
);
6942 /* This always returns the sal for the inner-most frame when we are in a
6943 stack of inlined frames, even if GDB actually believes that it is in a
6944 more outer frame. This is checked for below by calls to
6945 inline_skipped_frames. */
6946 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6948 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6949 the trampoline processing logic, however, there are some trampolines
6950 that have no names, so we should do trampoline handling first. */
6951 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6952 && ecs
->stop_func_name
== NULL
6953 && stop_pc_sal
.line
== 0)
6955 infrun_debug_printf ("stepped into undebuggable function");
6957 /* The inferior just stepped into, or returned to, an
6958 undebuggable function (where there is no debugging information
6959 and no line number corresponding to the address where the
6960 inferior stopped). Since we want to skip this kind of code,
6961 we keep going until the inferior returns from this
6962 function - unless the user has asked us not to (via
6963 set step-mode) or we no longer know how to get back
6964 to the call site. */
6965 if (step_stop_if_no_debug
6966 || !frame_id_p (frame_unwind_caller_id (frame
)))
6968 /* If we have no line number and the step-stop-if-no-debug
6969 is set, we stop the step so that the user has a chance to
6970 switch in assembly mode. */
6971 end_stepping_range (ecs
);
6976 /* Set a breakpoint at callee's return address (the address
6977 at which the caller will resume). */
6978 insert_step_resume_breakpoint_at_caller (frame
);
6984 if (ecs
->event_thread
->control
.step_range_end
== 1)
6986 /* It is stepi or nexti. We always want to stop stepping after
6988 infrun_debug_printf ("stepi/nexti");
6989 end_stepping_range (ecs
);
6993 if (stop_pc_sal
.line
== 0)
6995 /* We have no line number information. That means to stop
6996 stepping (does this always happen right after one instruction,
6997 when we do "s" in a function with no line numbers,
6998 or can this happen as a result of a return or longjmp?). */
6999 infrun_debug_printf ("line number info");
7000 end_stepping_range (ecs
);
7004 /* Look for "calls" to inlined functions, part one. If the inline
7005 frame machinery detected some skipped call sites, we have entered
7006 a new inline function. */
7008 if (frame_id_eq (get_frame_id (get_current_frame ()),
7009 ecs
->event_thread
->control
.step_frame_id
)
7010 && inline_skipped_frames (ecs
->event_thread
))
7012 infrun_debug_printf ("stepped into inlined function");
7014 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7016 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7018 /* For "step", we're going to stop. But if the call site
7019 for this inlined function is on the same source line as
7020 we were previously stepping, go down into the function
7021 first. Otherwise stop at the call site. */
7023 if (call_sal
.line
== ecs
->event_thread
->current_line
7024 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7026 step_into_inline_frame (ecs
->event_thread
);
7027 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7034 end_stepping_range (ecs
);
7039 /* For "next", we should stop at the call site if it is on a
7040 different source line. Otherwise continue through the
7041 inlined function. */
7042 if (call_sal
.line
== ecs
->event_thread
->current_line
7043 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7046 end_stepping_range (ecs
);
7051 /* Look for "calls" to inlined functions, part two. If we are still
7052 in the same real function we were stepping through, but we have
7053 to go further up to find the exact frame ID, we are stepping
7054 through a more inlined call beyond its call site. */
7056 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7057 && !frame_id_eq (get_frame_id (get_current_frame ()),
7058 ecs
->event_thread
->control
.step_frame_id
)
7059 && stepped_in_from (get_current_frame (),
7060 ecs
->event_thread
->control
.step_frame_id
))
7062 infrun_debug_printf ("stepping through inlined function");
7064 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7065 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7068 end_stepping_range (ecs
);
7072 bool refresh_step_info
= true;
7073 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7074 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7075 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7077 if (stop_pc_sal
.is_stmt
)
7079 /* We are at the start of a different line. So stop. Note that
7080 we don't stop if we step into the middle of a different line.
7081 That is said to make things like for (;;) statements work
7083 infrun_debug_printf ("stepped to a different line");
7084 end_stepping_range (ecs
);
7087 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7088 ecs
->event_thread
->control
.step_frame_id
))
7090 /* We are at the start of a different line, however, this line is
7091 not marked as a statement, and we have not changed frame. We
7092 ignore this line table entry, and continue stepping forward,
7093 looking for a better place to stop. */
7094 refresh_step_info
= false;
7095 infrun_debug_printf ("stepped to a different line, but "
7096 "it's not the start of a statement");
7100 /* We aren't done stepping.
7102 Optimize by setting the stepping range to the line.
7103 (We might not be in the original line, but if we entered a
7104 new line in mid-statement, we continue stepping. This makes
7105 things like for(;;) statements work better.)
7107 If we entered a SAL that indicates a non-statement line table entry,
7108 then we update the stepping range, but we don't update the step info,
7109 which includes things like the line number we are stepping away from.
7110 This means we will stop when we find a line table entry that is marked
7111 as is-statement, even if it matches the non-statement one we just
7114 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7115 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7116 ecs
->event_thread
->control
.may_range_step
= 1;
7117 if (refresh_step_info
)
7118 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7120 infrun_debug_printf ("keep going");
7124 /* In all-stop mode, if we're currently stepping but have stopped in
7125 some other thread, we may need to switch back to the stepped
7126 thread. Returns true we set the inferior running, false if we left
7127 it stopped (and the event needs further processing). */
7130 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7132 if (!target_is_non_stop_p ())
7134 struct thread_info
*stepping_thread
;
7136 /* If any thread is blocked on some internal breakpoint, and we
7137 simply need to step over that breakpoint to get it going
7138 again, do that first. */
7140 /* However, if we see an event for the stepping thread, then we
7141 know all other threads have been moved past their breakpoints
7142 already. Let the caller check whether the step is finished,
7143 etc., before deciding to move it past a breakpoint. */
7144 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7147 /* Check if the current thread is blocked on an incomplete
7148 step-over, interrupted by a random signal. */
7149 if (ecs
->event_thread
->control
.trap_expected
7150 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7153 ("need to finish step-over of [%s]",
7154 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7159 /* Check if the current thread is blocked by a single-step
7160 breakpoint of another thread. */
7161 if (ecs
->hit_singlestep_breakpoint
)
7163 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7164 target_pid_to_str (ecs
->ptid
).c_str ());
7169 /* If this thread needs yet another step-over (e.g., stepping
7170 through a delay slot), do it first before moving on to
7172 if (thread_still_needs_step_over (ecs
->event_thread
))
7175 ("thread [%s] still needs step-over",
7176 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7181 /* If scheduler locking applies even if not stepping, there's no
7182 need to walk over threads. Above we've checked whether the
7183 current thread is stepping. If some other thread not the
7184 event thread is stepping, then it must be that scheduler
7185 locking is not in effect. */
7186 if (schedlock_applies (ecs
->event_thread
))
7189 /* Otherwise, we no longer expect a trap in the current thread.
7190 Clear the trap_expected flag before switching back -- this is
7191 what keep_going does as well, if we call it. */
7192 ecs
->event_thread
->control
.trap_expected
= 0;
7194 /* Likewise, clear the signal if it should not be passed. */
7195 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7196 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7198 /* Do all pending step-overs before actually proceeding with
7200 if (start_step_over ())
7202 prepare_to_wait (ecs
);
7206 /* Look for the stepping/nexting thread. */
7207 stepping_thread
= NULL
;
7209 for (thread_info
*tp
: all_non_exited_threads ())
7211 switch_to_thread_no_regs (tp
);
7213 /* Ignore threads of processes the caller is not
7216 && (tp
->inf
->process_target () != ecs
->target
7217 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7220 /* When stepping over a breakpoint, we lock all threads
7221 except the one that needs to move past the breakpoint.
7222 If a non-event thread has this set, the "incomplete
7223 step-over" check above should have caught it earlier. */
7224 if (tp
->control
.trap_expected
)
7226 internal_error (__FILE__
, __LINE__
,
7227 "[%s] has inconsistent state: "
7228 "trap_expected=%d\n",
7229 target_pid_to_str (tp
->ptid
).c_str (),
7230 tp
->control
.trap_expected
);
7233 /* Did we find the stepping thread? */
7234 if (tp
->control
.step_range_end
)
7236 /* Yep. There should only one though. */
7237 gdb_assert (stepping_thread
== NULL
);
7239 /* The event thread is handled at the top, before we
7241 gdb_assert (tp
!= ecs
->event_thread
);
7243 /* If some thread other than the event thread is
7244 stepping, then scheduler locking can't be in effect,
7245 otherwise we wouldn't have resumed the current event
7246 thread in the first place. */
7247 gdb_assert (!schedlock_applies (tp
));
7249 stepping_thread
= tp
;
7253 if (stepping_thread
!= NULL
)
7255 infrun_debug_printf ("switching back to stepped thread");
7257 if (keep_going_stepped_thread (stepping_thread
))
7259 prepare_to_wait (ecs
);
7264 switch_to_thread (ecs
->event_thread
);
7270 /* Set a previously stepped thread back to stepping. Returns true on
7271 success, false if the resume is not possible (e.g., the thread
7275 keep_going_stepped_thread (struct thread_info
*tp
)
7277 struct frame_info
*frame
;
7278 struct execution_control_state ecss
;
7279 struct execution_control_state
*ecs
= &ecss
;
7281 /* If the stepping thread exited, then don't try to switch back and
7282 resume it, which could fail in several different ways depending
7283 on the target. Instead, just keep going.
7285 We can find a stepping dead thread in the thread list in two
7288 - The target supports thread exit events, and when the target
7289 tries to delete the thread from the thread list, inferior_ptid
7290 pointed at the exiting thread. In such case, calling
7291 delete_thread does not really remove the thread from the list;
7292 instead, the thread is left listed, with 'exited' state.
7294 - The target's debug interface does not support thread exit
7295 events, and so we have no idea whatsoever if the previously
7296 stepping thread is still alive. For that reason, we need to
7297 synchronously query the target now. */
7299 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7301 infrun_debug_printf ("not resuming previously stepped thread, it has "
7308 infrun_debug_printf ("resuming previously stepped thread");
7310 reset_ecs (ecs
, tp
);
7311 switch_to_thread (tp
);
7313 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7314 frame
= get_current_frame ();
7316 /* If the PC of the thread we were trying to single-step has
7317 changed, then that thread has trapped or been signaled, but the
7318 event has not been reported to GDB yet. Re-poll the target
7319 looking for this particular thread's event (i.e. temporarily
7320 enable schedlock) by:
7322 - setting a break at the current PC
7323 - resuming that particular thread, only (by setting trap
7326 This prevents us continuously moving the single-step breakpoint
7327 forward, one instruction at a time, overstepping. */
7329 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7333 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7334 paddress (target_gdbarch (), tp
->prev_pc
),
7335 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7337 /* Clear the info of the previous step-over, as it's no longer
7338 valid (if the thread was trying to step over a breakpoint, it
7339 has already succeeded). It's what keep_going would do too,
7340 if we called it. Do this before trying to insert the sss
7341 breakpoint, otherwise if we were previously trying to step
7342 over this exact address in another thread, the breakpoint is
7344 clear_step_over_info ();
7345 tp
->control
.trap_expected
= 0;
7347 insert_single_step_breakpoint (get_frame_arch (frame
),
7348 get_frame_address_space (frame
),
7349 tp
->suspend
.stop_pc
);
7352 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7353 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7357 infrun_debug_printf ("expected thread still hasn't advanced");
7359 keep_going_pass_signal (ecs
);
7364 /* Is thread TP in the middle of (software or hardware)
7365 single-stepping? (Note the result of this function must never be
7366 passed directly as target_resume's STEP parameter.) */
7369 currently_stepping (struct thread_info
*tp
)
7371 return ((tp
->control
.step_range_end
7372 && tp
->control
.step_resume_breakpoint
== NULL
)
7373 || tp
->control
.trap_expected
7374 || tp
->stepped_breakpoint
7375 || bpstat_should_step ());
7378 /* Inferior has stepped into a subroutine call with source code that
7379 we should not step over. Do step to the first line of code in
7383 handle_step_into_function (struct gdbarch
*gdbarch
,
7384 struct execution_control_state
*ecs
)
7386 fill_in_stop_func (gdbarch
, ecs
);
7388 compunit_symtab
*cust
7389 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7390 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7391 ecs
->stop_func_start
7392 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7394 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7395 /* Use the step_resume_break to step until the end of the prologue,
7396 even if that involves jumps (as it seems to on the vax under
7398 /* If the prologue ends in the middle of a source line, continue to
7399 the end of that source line (if it is still within the function).
7400 Otherwise, just go to end of prologue. */
7401 if (stop_func_sal
.end
7402 && stop_func_sal
.pc
!= ecs
->stop_func_start
7403 && stop_func_sal
.end
< ecs
->stop_func_end
)
7404 ecs
->stop_func_start
= stop_func_sal
.end
;
7406 /* Architectures which require breakpoint adjustment might not be able
7407 to place a breakpoint at the computed address. If so, the test
7408 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7409 ecs->stop_func_start to an address at which a breakpoint may be
7410 legitimately placed.
7412 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7413 made, GDB will enter an infinite loop when stepping through
7414 optimized code consisting of VLIW instructions which contain
7415 subinstructions corresponding to different source lines. On
7416 FR-V, it's not permitted to place a breakpoint on any but the
7417 first subinstruction of a VLIW instruction. When a breakpoint is
7418 set, GDB will adjust the breakpoint address to the beginning of
7419 the VLIW instruction. Thus, we need to make the corresponding
7420 adjustment here when computing the stop address. */
7422 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7424 ecs
->stop_func_start
7425 = gdbarch_adjust_breakpoint_address (gdbarch
,
7426 ecs
->stop_func_start
);
7429 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7431 /* We are already there: stop now. */
7432 end_stepping_range (ecs
);
7437 /* Put the step-breakpoint there and go until there. */
7438 symtab_and_line sr_sal
;
7439 sr_sal
.pc
= ecs
->stop_func_start
;
7440 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7441 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7443 /* Do not specify what the fp should be when we stop since on
7444 some machines the prologue is where the new fp value is
7446 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7448 /* And make sure stepping stops right away then. */
7449 ecs
->event_thread
->control
.step_range_end
7450 = ecs
->event_thread
->control
.step_range_start
;
7455 /* Inferior has stepped backward into a subroutine call with source
7456 code that we should not step over. Do step to the beginning of the
7457 last line of code in it. */
7460 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7461 struct execution_control_state
*ecs
)
7463 struct compunit_symtab
*cust
;
7464 struct symtab_and_line stop_func_sal
;
7466 fill_in_stop_func (gdbarch
, ecs
);
7468 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7469 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7470 ecs
->stop_func_start
7471 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7473 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7475 /* OK, we're just going to keep stepping here. */
7476 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7478 /* We're there already. Just stop stepping now. */
7479 end_stepping_range (ecs
);
7483 /* Else just reset the step range and keep going.
7484 No step-resume breakpoint, they don't work for
7485 epilogues, which can have multiple entry paths. */
7486 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7487 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7493 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7494 This is used to both functions and to skip over code. */
7497 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7498 struct symtab_and_line sr_sal
,
7499 struct frame_id sr_id
,
7500 enum bptype sr_type
)
7502 /* There should never be more than one step-resume or longjmp-resume
7503 breakpoint per thread, so we should never be setting a new
7504 step_resume_breakpoint when one is already active. */
7505 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7506 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7508 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7509 paddress (gdbarch
, sr_sal
.pc
));
7511 inferior_thread ()->control
.step_resume_breakpoint
7512 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7516 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7517 struct symtab_and_line sr_sal
,
7518 struct frame_id sr_id
)
7520 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7525 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7526 This is used to skip a potential signal handler.
7528 This is called with the interrupted function's frame. The signal
7529 handler, when it returns, will resume the interrupted function at
7533 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7535 gdb_assert (return_frame
!= NULL
);
7537 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7539 symtab_and_line sr_sal
;
7540 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7541 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7542 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7544 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7545 get_stack_frame_id (return_frame
),
7549 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7550 is used to skip a function after stepping into it (for "next" or if
7551 the called function has no debugging information).
7553 The current function has almost always been reached by single
7554 stepping a call or return instruction. NEXT_FRAME belongs to the
7555 current function, and the breakpoint will be set at the caller's
7558 This is a separate function rather than reusing
7559 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7560 get_prev_frame, which may stop prematurely (see the implementation
7561 of frame_unwind_caller_id for an example). */
7564 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7566 /* We shouldn't have gotten here if we don't know where the call site
7568 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7570 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7572 symtab_and_line sr_sal
;
7573 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7574 frame_unwind_caller_pc (next_frame
));
7575 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7576 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7578 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7579 frame_unwind_caller_id (next_frame
));
7582 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7583 new breakpoint at the target of a jmp_buf. The handling of
7584 longjmp-resume uses the same mechanisms used for handling
7585 "step-resume" breakpoints. */
7588 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7590 /* There should never be more than one longjmp-resume breakpoint per
7591 thread, so we should never be setting a new
7592 longjmp_resume_breakpoint when one is already active. */
7593 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7595 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7596 paddress (gdbarch
, pc
));
7598 inferior_thread ()->control
.exception_resume_breakpoint
=
7599 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7602 /* Insert an exception resume breakpoint. TP is the thread throwing
7603 the exception. The block B is the block of the unwinder debug hook
7604 function. FRAME is the frame corresponding to the call to this
7605 function. SYM is the symbol of the function argument holding the
7606 target PC of the exception. */
7609 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7610 const struct block
*b
,
7611 struct frame_info
*frame
,
7616 struct block_symbol vsym
;
7617 struct value
*value
;
7619 struct breakpoint
*bp
;
7621 vsym
= lookup_symbol_search_name (sym
->search_name (),
7623 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7624 /* If the value was optimized out, revert to the old behavior. */
7625 if (! value_optimized_out (value
))
7627 handler
= value_as_address (value
);
7629 infrun_debug_printf ("exception resume at %lx",
7630 (unsigned long) handler
);
7632 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7634 bp_exception_resume
).release ();
7636 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7639 bp
->thread
= tp
->global_num
;
7640 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7643 catch (const gdb_exception_error
&e
)
7645 /* We want to ignore errors here. */
7649 /* A helper for check_exception_resume that sets an
7650 exception-breakpoint based on a SystemTap probe. */
7653 insert_exception_resume_from_probe (struct thread_info
*tp
,
7654 const struct bound_probe
*probe
,
7655 struct frame_info
*frame
)
7657 struct value
*arg_value
;
7659 struct breakpoint
*bp
;
7661 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7665 handler
= value_as_address (arg_value
);
7667 infrun_debug_printf ("exception resume at %s",
7668 paddress (probe
->objfile
->arch (), handler
));
7670 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7671 handler
, bp_exception_resume
).release ();
7672 bp
->thread
= tp
->global_num
;
7673 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7676 /* This is called when an exception has been intercepted. Check to
7677 see whether the exception's destination is of interest, and if so,
7678 set an exception resume breakpoint there. */
7681 check_exception_resume (struct execution_control_state
*ecs
,
7682 struct frame_info
*frame
)
7684 struct bound_probe probe
;
7685 struct symbol
*func
;
7687 /* First see if this exception unwinding breakpoint was set via a
7688 SystemTap probe point. If so, the probe has two arguments: the
7689 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7690 set a breakpoint there. */
7691 probe
= find_probe_by_pc (get_frame_pc (frame
));
7694 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7698 func
= get_frame_function (frame
);
7704 const struct block
*b
;
7705 struct block_iterator iter
;
7709 /* The exception breakpoint is a thread-specific breakpoint on
7710 the unwinder's debug hook, declared as:
7712 void _Unwind_DebugHook (void *cfa, void *handler);
7714 The CFA argument indicates the frame to which control is
7715 about to be transferred. HANDLER is the destination PC.
7717 We ignore the CFA and set a temporary breakpoint at HANDLER.
7718 This is not extremely efficient but it avoids issues in gdb
7719 with computing the DWARF CFA, and it also works even in weird
7720 cases such as throwing an exception from inside a signal
7723 b
= SYMBOL_BLOCK_VALUE (func
);
7724 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7726 if (!SYMBOL_IS_ARGUMENT (sym
))
7733 insert_exception_resume_breakpoint (ecs
->event_thread
,
7739 catch (const gdb_exception_error
&e
)
7745 stop_waiting (struct execution_control_state
*ecs
)
7747 infrun_debug_printf ("stop_waiting");
7749 /* Let callers know we don't want to wait for the inferior anymore. */
7750 ecs
->wait_some_more
= 0;
7752 /* If all-stop, but there exists a non-stop target, stop all
7753 threads now that we're presenting the stop to the user. */
7754 if (!non_stop
&& exists_non_stop_target ())
7755 stop_all_threads ();
7758 /* Like keep_going, but passes the signal to the inferior, even if the
7759 signal is set to nopass. */
7762 keep_going_pass_signal (struct execution_control_state
*ecs
)
7764 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7765 gdb_assert (!ecs
->event_thread
->resumed
);
7767 /* Save the pc before execution, to compare with pc after stop. */
7768 ecs
->event_thread
->prev_pc
7769 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7771 if (ecs
->event_thread
->control
.trap_expected
)
7773 struct thread_info
*tp
= ecs
->event_thread
;
7775 infrun_debug_printf ("%s has trap_expected set, "
7776 "resuming to collect trap",
7777 target_pid_to_str (tp
->ptid
).c_str ());
7779 /* We haven't yet gotten our trap, and either: intercepted a
7780 non-signal event (e.g., a fork); or took a signal which we
7781 are supposed to pass through to the inferior. Simply
7783 resume (ecs
->event_thread
->suspend
.stop_signal
);
7785 else if (step_over_info_valid_p ())
7787 /* Another thread is stepping over a breakpoint in-line. If
7788 this thread needs a step-over too, queue the request. In
7789 either case, this resume must be deferred for later. */
7790 struct thread_info
*tp
= ecs
->event_thread
;
7792 if (ecs
->hit_singlestep_breakpoint
7793 || thread_still_needs_step_over (tp
))
7795 infrun_debug_printf ("step-over already in progress: "
7796 "step-over for %s deferred",
7797 target_pid_to_str (tp
->ptid
).c_str ());
7798 thread_step_over_chain_enqueue (tp
);
7802 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7803 target_pid_to_str (tp
->ptid
).c_str ());
7808 struct regcache
*regcache
= get_current_regcache ();
7811 step_over_what step_what
;
7813 /* Either the trap was not expected, but we are continuing
7814 anyway (if we got a signal, the user asked it be passed to
7817 We got our expected trap, but decided we should resume from
7820 We're going to run this baby now!
7822 Note that insert_breakpoints won't try to re-insert
7823 already inserted breakpoints. Therefore, we don't
7824 care if breakpoints were already inserted, or not. */
7826 /* If we need to step over a breakpoint, and we're not using
7827 displaced stepping to do so, insert all breakpoints
7828 (watchpoints, etc.) but the one we're stepping over, step one
7829 instruction, and then re-insert the breakpoint when that step
7832 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7834 remove_bp
= (ecs
->hit_singlestep_breakpoint
7835 || (step_what
& STEP_OVER_BREAKPOINT
));
7836 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7838 /* We can't use displaced stepping if we need to step past a
7839 watchpoint. The instruction copied to the scratch pad would
7840 still trigger the watchpoint. */
7842 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7844 set_step_over_info (regcache
->aspace (),
7845 regcache_read_pc (regcache
), remove_wps
,
7846 ecs
->event_thread
->global_num
);
7848 else if (remove_wps
)
7849 set_step_over_info (NULL
, 0, remove_wps
, -1);
7851 /* If we now need to do an in-line step-over, we need to stop
7852 all other threads. Note this must be done before
7853 insert_breakpoints below, because that removes the breakpoint
7854 we're about to step over, otherwise other threads could miss
7856 if (step_over_info_valid_p () && target_is_non_stop_p ())
7857 stop_all_threads ();
7859 /* Stop stepping if inserting breakpoints fails. */
7862 insert_breakpoints ();
7864 catch (const gdb_exception_error
&e
)
7866 exception_print (gdb_stderr
, e
);
7868 clear_step_over_info ();
7872 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7874 resume (ecs
->event_thread
->suspend
.stop_signal
);
7877 prepare_to_wait (ecs
);
7880 /* Called when we should continue running the inferior, because the
7881 current event doesn't cause a user visible stop. This does the
7882 resuming part; waiting for the next event is done elsewhere. */
7885 keep_going (struct execution_control_state
*ecs
)
7887 if (ecs
->event_thread
->control
.trap_expected
7888 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7889 ecs
->event_thread
->control
.trap_expected
= 0;
7891 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7892 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7893 keep_going_pass_signal (ecs
);
7896 /* This function normally comes after a resume, before
7897 handle_inferior_event exits. It takes care of any last bits of
7898 housekeeping, and sets the all-important wait_some_more flag. */
7901 prepare_to_wait (struct execution_control_state
*ecs
)
7903 infrun_debug_printf ("prepare_to_wait");
7905 ecs
->wait_some_more
= 1;
7907 /* If the target can't async, emulate it by marking the infrun event
7908 handler such that as soon as we get back to the event-loop, we
7909 immediately end up in fetch_inferior_event again calling
7911 if (!target_can_async_p ())
7912 mark_infrun_async_event_handler ();
7915 /* We are done with the step range of a step/next/si/ni command.
7916 Called once for each n of a "step n" operation. */
7919 end_stepping_range (struct execution_control_state
*ecs
)
7921 ecs
->event_thread
->control
.stop_step
= 1;
7925 /* Several print_*_reason functions to print why the inferior has stopped.
7926 We always print something when the inferior exits, or receives a signal.
7927 The rest of the cases are dealt with later on in normal_stop and
7928 print_it_typical. Ideally there should be a call to one of these
7929 print_*_reason functions functions from handle_inferior_event each time
7930 stop_waiting is called.
7932 Note that we don't call these directly, instead we delegate that to
7933 the interpreters, through observers. Interpreters then call these
7934 with whatever uiout is right. */
7937 print_end_stepping_range_reason (struct ui_out
*uiout
)
7939 /* For CLI-like interpreters, print nothing. */
7941 if (uiout
->is_mi_like_p ())
7943 uiout
->field_string ("reason",
7944 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7949 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7951 annotate_signalled ();
7952 if (uiout
->is_mi_like_p ())
7954 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7955 uiout
->text ("\nProgram terminated with signal ");
7956 annotate_signal_name ();
7957 uiout
->field_string ("signal-name",
7958 gdb_signal_to_name (siggnal
));
7959 annotate_signal_name_end ();
7961 annotate_signal_string ();
7962 uiout
->field_string ("signal-meaning",
7963 gdb_signal_to_string (siggnal
));
7964 annotate_signal_string_end ();
7965 uiout
->text (".\n");
7966 uiout
->text ("The program no longer exists.\n");
7970 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7972 struct inferior
*inf
= current_inferior ();
7973 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7975 annotate_exited (exitstatus
);
7978 if (uiout
->is_mi_like_p ())
7979 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7980 std::string exit_code_str
7981 = string_printf ("0%o", (unsigned int) exitstatus
);
7982 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7983 plongest (inf
->num
), pidstr
.c_str (),
7984 string_field ("exit-code", exit_code_str
.c_str ()));
7988 if (uiout
->is_mi_like_p ())
7990 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7991 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7992 plongest (inf
->num
), pidstr
.c_str ());
7997 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7999 struct thread_info
*thr
= inferior_thread ();
8003 if (uiout
->is_mi_like_p ())
8005 else if (show_thread_that_caused_stop ())
8009 uiout
->text ("\nThread ");
8010 uiout
->field_string ("thread-id", print_thread_id (thr
));
8012 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8015 uiout
->text (" \"");
8016 uiout
->field_string ("name", name
);
8021 uiout
->text ("\nProgram");
8023 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8024 uiout
->text (" stopped");
8027 uiout
->text (" received signal ");
8028 annotate_signal_name ();
8029 if (uiout
->is_mi_like_p ())
8031 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8032 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8033 annotate_signal_name_end ();
8035 annotate_signal_string ();
8036 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8038 struct regcache
*regcache
= get_current_regcache ();
8039 struct gdbarch
*gdbarch
= regcache
->arch ();
8040 if (gdbarch_report_signal_info_p (gdbarch
))
8041 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8043 annotate_signal_string_end ();
8045 uiout
->text (".\n");
8049 print_no_history_reason (struct ui_out
*uiout
)
8051 uiout
->text ("\nNo more reverse-execution history.\n");
8054 /* Print current location without a level number, if we have changed
8055 functions or hit a breakpoint. Print source line if we have one.
8056 bpstat_print contains the logic deciding in detail what to print,
8057 based on the event(s) that just occurred. */
8060 print_stop_location (struct target_waitstatus
*ws
)
8063 enum print_what source_flag
;
8064 int do_frame_printing
= 1;
8065 struct thread_info
*tp
= inferior_thread ();
8067 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8071 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8072 should) carry around the function and does (or should) use
8073 that when doing a frame comparison. */
8074 if (tp
->control
.stop_step
8075 && frame_id_eq (tp
->control
.step_frame_id
,
8076 get_frame_id (get_current_frame ()))
8077 && (tp
->control
.step_start_function
8078 == find_pc_function (tp
->suspend
.stop_pc
)))
8080 /* Finished step, just print source line. */
8081 source_flag
= SRC_LINE
;
8085 /* Print location and source line. */
8086 source_flag
= SRC_AND_LOC
;
8089 case PRINT_SRC_AND_LOC
:
8090 /* Print location and source line. */
8091 source_flag
= SRC_AND_LOC
;
8093 case PRINT_SRC_ONLY
:
8094 source_flag
= SRC_LINE
;
8097 /* Something bogus. */
8098 source_flag
= SRC_LINE
;
8099 do_frame_printing
= 0;
8102 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8105 /* The behavior of this routine with respect to the source
8107 SRC_LINE: Print only source line
8108 LOCATION: Print only location
8109 SRC_AND_LOC: Print location and source line. */
8110 if (do_frame_printing
)
8111 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8117 print_stop_event (struct ui_out
*uiout
, bool displays
)
8119 struct target_waitstatus last
;
8120 struct thread_info
*tp
;
8122 get_last_target_status (nullptr, nullptr, &last
);
8125 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8127 print_stop_location (&last
);
8129 /* Display the auto-display expressions. */
8134 tp
= inferior_thread ();
8135 if (tp
->thread_fsm
!= NULL
8136 && tp
->thread_fsm
->finished_p ())
8138 struct return_value_info
*rv
;
8140 rv
= tp
->thread_fsm
->return_value ();
8142 print_return_value (uiout
, rv
);
8149 maybe_remove_breakpoints (void)
8151 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8153 if (remove_breakpoints ())
8155 target_terminal::ours_for_output ();
8156 printf_filtered (_("Cannot remove breakpoints because "
8157 "program is no longer writable.\nFurther "
8158 "execution is probably impossible.\n"));
8163 /* The execution context that just caused a normal stop. */
8170 DISABLE_COPY_AND_ASSIGN (stop_context
);
8172 bool changed () const;
8177 /* The event PTID. */
8181 /* If stopp for a thread event, this is the thread that caused the
8183 struct thread_info
*thread
;
8185 /* The inferior that caused the stop. */
8189 /* Initializes a new stop context. If stopped for a thread event, this
8190 takes a strong reference to the thread. */
8192 stop_context::stop_context ()
8194 stop_id
= get_stop_id ();
8195 ptid
= inferior_ptid
;
8196 inf_num
= current_inferior ()->num
;
8198 if (inferior_ptid
!= null_ptid
)
8200 /* Take a strong reference so that the thread can't be deleted
8202 thread
= inferior_thread ();
8209 /* Release a stop context previously created with save_stop_context.
8210 Releases the strong reference to the thread as well. */
8212 stop_context::~stop_context ()
8218 /* Return true if the current context no longer matches the saved stop
8222 stop_context::changed () const
8224 if (ptid
!= inferior_ptid
)
8226 if (inf_num
!= current_inferior ()->num
)
8228 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8230 if (get_stop_id () != stop_id
)
8240 struct target_waitstatus last
;
8242 get_last_target_status (nullptr, nullptr, &last
);
8246 /* If an exception is thrown from this point on, make sure to
8247 propagate GDB's knowledge of the executing state to the
8248 frontend/user running state. A QUIT is an easy exception to see
8249 here, so do this before any filtered output. */
8251 ptid_t finish_ptid
= null_ptid
;
8254 finish_ptid
= minus_one_ptid
;
8255 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8256 || last
.kind
== TARGET_WAITKIND_EXITED
)
8258 /* On some targets, we may still have live threads in the
8259 inferior when we get a process exit event. E.g., for
8260 "checkpoint", when the current checkpoint/fork exits,
8261 linux-fork.c automatically switches to another fork from
8262 within target_mourn_inferior. */
8263 if (inferior_ptid
!= null_ptid
)
8264 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8266 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8267 finish_ptid
= inferior_ptid
;
8269 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8270 if (finish_ptid
!= null_ptid
)
8272 maybe_finish_thread_state
.emplace
8273 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8276 /* As we're presenting a stop, and potentially removing breakpoints,
8277 update the thread list so we can tell whether there are threads
8278 running on the target. With target remote, for example, we can
8279 only learn about new threads when we explicitly update the thread
8280 list. Do this before notifying the interpreters about signal
8281 stops, end of stepping ranges, etc., so that the "new thread"
8282 output is emitted before e.g., "Program received signal FOO",
8283 instead of after. */
8284 update_thread_list ();
8286 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8287 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8289 /* As with the notification of thread events, we want to delay
8290 notifying the user that we've switched thread context until
8291 the inferior actually stops.
8293 There's no point in saying anything if the inferior has exited.
8294 Note that SIGNALLED here means "exited with a signal", not
8295 "received a signal".
8297 Also skip saying anything in non-stop mode. In that mode, as we
8298 don't want GDB to switch threads behind the user's back, to avoid
8299 races where the user is typing a command to apply to thread x,
8300 but GDB switches to thread y before the user finishes entering
8301 the command, fetch_inferior_event installs a cleanup to restore
8302 the current thread back to the thread the user had selected right
8303 after this event is handled, so we're not really switching, only
8304 informing of a stop. */
8306 && previous_inferior_ptid
!= inferior_ptid
8307 && target_has_execution
8308 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8309 && last
.kind
!= TARGET_WAITKIND_EXITED
8310 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8312 SWITCH_THRU_ALL_UIS ()
8314 target_terminal::ours_for_output ();
8315 printf_filtered (_("[Switching to %s]\n"),
8316 target_pid_to_str (inferior_ptid
).c_str ());
8317 annotate_thread_changed ();
8319 previous_inferior_ptid
= inferior_ptid
;
8322 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8324 SWITCH_THRU_ALL_UIS ()
8325 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8327 target_terminal::ours_for_output ();
8328 printf_filtered (_("No unwaited-for children left.\n"));
8332 /* Note: this depends on the update_thread_list call above. */
8333 maybe_remove_breakpoints ();
8335 /* If an auto-display called a function and that got a signal,
8336 delete that auto-display to avoid an infinite recursion. */
8338 if (stopped_by_random_signal
)
8339 disable_current_display ();
8341 SWITCH_THRU_ALL_UIS ()
8343 async_enable_stdin ();
8346 /* Let the user/frontend see the threads as stopped. */
8347 maybe_finish_thread_state
.reset ();
8349 /* Select innermost stack frame - i.e., current frame is frame 0,
8350 and current location is based on that. Handle the case where the
8351 dummy call is returning after being stopped. E.g. the dummy call
8352 previously hit a breakpoint. (If the dummy call returns
8353 normally, we won't reach here.) Do this before the stop hook is
8354 run, so that it doesn't get to see the temporary dummy frame,
8355 which is not where we'll present the stop. */
8356 if (has_stack_frames ())
8358 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8360 /* Pop the empty frame that contains the stack dummy. This
8361 also restores inferior state prior to the call (struct
8362 infcall_suspend_state). */
8363 struct frame_info
*frame
= get_current_frame ();
8365 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8367 /* frame_pop calls reinit_frame_cache as the last thing it
8368 does which means there's now no selected frame. */
8371 select_frame (get_current_frame ());
8373 /* Set the current source location. */
8374 set_current_sal_from_frame (get_current_frame ());
8377 /* Look up the hook_stop and run it (CLI internally handles problem
8378 of stop_command's pre-hook not existing). */
8379 if (stop_command
!= NULL
)
8381 stop_context saved_context
;
8385 execute_cmd_pre_hook (stop_command
);
8387 catch (const gdb_exception
&ex
)
8389 exception_fprintf (gdb_stderr
, ex
,
8390 "Error while running hook_stop:\n");
8393 /* If the stop hook resumes the target, then there's no point in
8394 trying to notify about the previous stop; its context is
8395 gone. Likewise if the command switches thread or inferior --
8396 the observers would print a stop for the wrong
8398 if (saved_context
.changed ())
8402 /* Notify observers about the stop. This is where the interpreters
8403 print the stop event. */
8404 if (inferior_ptid
!= null_ptid
)
8405 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8408 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8410 annotate_stopped ();
8412 if (target_has_execution
)
8414 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8415 && last
.kind
!= TARGET_WAITKIND_EXITED
8416 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8417 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8418 Delete any breakpoint that is to be deleted at the next stop. */
8419 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8422 /* Try to get rid of automatically added inferiors that are no
8423 longer needed. Keeping those around slows down things linearly.
8424 Note that this never removes the current inferior. */
8431 signal_stop_state (int signo
)
8433 return signal_stop
[signo
];
8437 signal_print_state (int signo
)
8439 return signal_print
[signo
];
8443 signal_pass_state (int signo
)
8445 return signal_program
[signo
];
8449 signal_cache_update (int signo
)
8453 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8454 signal_cache_update (signo
);
8459 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8460 && signal_print
[signo
] == 0
8461 && signal_program
[signo
] == 1
8462 && signal_catch
[signo
] == 0);
8466 signal_stop_update (int signo
, int state
)
8468 int ret
= signal_stop
[signo
];
8470 signal_stop
[signo
] = state
;
8471 signal_cache_update (signo
);
8476 signal_print_update (int signo
, int state
)
8478 int ret
= signal_print
[signo
];
8480 signal_print
[signo
] = state
;
8481 signal_cache_update (signo
);
8486 signal_pass_update (int signo
, int state
)
8488 int ret
= signal_program
[signo
];
8490 signal_program
[signo
] = state
;
8491 signal_cache_update (signo
);
8495 /* Update the global 'signal_catch' from INFO and notify the
8499 signal_catch_update (const unsigned int *info
)
8503 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8504 signal_catch
[i
] = info
[i
] > 0;
8505 signal_cache_update (-1);
8506 target_pass_signals (signal_pass
);
8510 sig_print_header (void)
8512 printf_filtered (_("Signal Stop\tPrint\tPass "
8513 "to program\tDescription\n"));
8517 sig_print_info (enum gdb_signal oursig
)
8519 const char *name
= gdb_signal_to_name (oursig
);
8520 int name_padding
= 13 - strlen (name
);
8522 if (name_padding
<= 0)
8525 printf_filtered ("%s", name
);
8526 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8527 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8528 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8529 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8530 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8533 /* Specify how various signals in the inferior should be handled. */
8536 handle_command (const char *args
, int from_tty
)
8538 int digits
, wordlen
;
8539 int sigfirst
, siglast
;
8540 enum gdb_signal oursig
;
8545 error_no_arg (_("signal to handle"));
8548 /* Allocate and zero an array of flags for which signals to handle. */
8550 const size_t nsigs
= GDB_SIGNAL_LAST
;
8551 unsigned char sigs
[nsigs
] {};
8553 /* Break the command line up into args. */
8555 gdb_argv
built_argv (args
);
8557 /* Walk through the args, looking for signal oursigs, signal names, and
8558 actions. Signal numbers and signal names may be interspersed with
8559 actions, with the actions being performed for all signals cumulatively
8560 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8562 for (char *arg
: built_argv
)
8564 wordlen
= strlen (arg
);
8565 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8569 sigfirst
= siglast
= -1;
8571 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8573 /* Apply action to all signals except those used by the
8574 debugger. Silently skip those. */
8577 siglast
= nsigs
- 1;
8579 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8581 SET_SIGS (nsigs
, sigs
, signal_stop
);
8582 SET_SIGS (nsigs
, sigs
, signal_print
);
8584 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8586 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8588 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8590 SET_SIGS (nsigs
, sigs
, signal_print
);
8592 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8594 SET_SIGS (nsigs
, sigs
, signal_program
);
8596 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8598 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8600 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8602 SET_SIGS (nsigs
, sigs
, signal_program
);
8604 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8606 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8607 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8609 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8611 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8613 else if (digits
> 0)
8615 /* It is numeric. The numeric signal refers to our own
8616 internal signal numbering from target.h, not to host/target
8617 signal number. This is a feature; users really should be
8618 using symbolic names anyway, and the common ones like
8619 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8621 sigfirst
= siglast
= (int)
8622 gdb_signal_from_command (atoi (arg
));
8623 if (arg
[digits
] == '-')
8626 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8628 if (sigfirst
> siglast
)
8630 /* Bet he didn't figure we'd think of this case... */
8631 std::swap (sigfirst
, siglast
);
8636 oursig
= gdb_signal_from_name (arg
);
8637 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8639 sigfirst
= siglast
= (int) oursig
;
8643 /* Not a number and not a recognized flag word => complain. */
8644 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8648 /* If any signal numbers or symbol names were found, set flags for
8649 which signals to apply actions to. */
8651 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8653 switch ((enum gdb_signal
) signum
)
8655 case GDB_SIGNAL_TRAP
:
8656 case GDB_SIGNAL_INT
:
8657 if (!allsigs
&& !sigs
[signum
])
8659 if (query (_("%s is used by the debugger.\n\
8660 Are you sure you want to change it? "),
8661 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8666 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8670 case GDB_SIGNAL_DEFAULT
:
8671 case GDB_SIGNAL_UNKNOWN
:
8672 /* Make sure that "all" doesn't print these. */
8681 for (int signum
= 0; signum
< nsigs
; signum
++)
8684 signal_cache_update (-1);
8685 target_pass_signals (signal_pass
);
8686 target_program_signals (signal_program
);
8690 /* Show the results. */
8691 sig_print_header ();
8692 for (; signum
< nsigs
; signum
++)
8694 sig_print_info ((enum gdb_signal
) signum
);
8701 /* Complete the "handle" command. */
8704 handle_completer (struct cmd_list_element
*ignore
,
8705 completion_tracker
&tracker
,
8706 const char *text
, const char *word
)
8708 static const char * const keywords
[] =
8722 signal_completer (ignore
, tracker
, text
, word
);
8723 complete_on_enum (tracker
, keywords
, word
, word
);
8727 gdb_signal_from_command (int num
)
8729 if (num
>= 1 && num
<= 15)
8730 return (enum gdb_signal
) num
;
8731 error (_("Only signals 1-15 are valid as numeric signals.\n\
8732 Use \"info signals\" for a list of symbolic signals."));
8735 /* Print current contents of the tables set by the handle command.
8736 It is possible we should just be printing signals actually used
8737 by the current target (but for things to work right when switching
8738 targets, all signals should be in the signal tables). */
8741 info_signals_command (const char *signum_exp
, int from_tty
)
8743 enum gdb_signal oursig
;
8745 sig_print_header ();
8749 /* First see if this is a symbol name. */
8750 oursig
= gdb_signal_from_name (signum_exp
);
8751 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8753 /* No, try numeric. */
8755 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8757 sig_print_info (oursig
);
8761 printf_filtered ("\n");
8762 /* These ugly casts brought to you by the native VAX compiler. */
8763 for (oursig
= GDB_SIGNAL_FIRST
;
8764 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8765 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8769 if (oursig
!= GDB_SIGNAL_UNKNOWN
8770 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8771 sig_print_info (oursig
);
8774 printf_filtered (_("\nUse the \"handle\" command "
8775 "to change these tables.\n"));
8778 /* The $_siginfo convenience variable is a bit special. We don't know
8779 for sure the type of the value until we actually have a chance to
8780 fetch the data. The type can change depending on gdbarch, so it is
8781 also dependent on which thread you have selected.
8783 1. making $_siginfo be an internalvar that creates a new value on
8786 2. making the value of $_siginfo be an lval_computed value. */
8788 /* This function implements the lval_computed support for reading a
8792 siginfo_value_read (struct value
*v
)
8794 LONGEST transferred
;
8796 /* If we can access registers, so can we access $_siginfo. Likewise
8798 validate_registers_access ();
8801 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8803 value_contents_all_raw (v
),
8805 TYPE_LENGTH (value_type (v
)));
8807 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8808 error (_("Unable to read siginfo"));
8811 /* This function implements the lval_computed support for writing a
8815 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8817 LONGEST transferred
;
8819 /* If we can access registers, so can we access $_siginfo. Likewise
8821 validate_registers_access ();
8823 transferred
= target_write (current_top_target (),
8824 TARGET_OBJECT_SIGNAL_INFO
,
8826 value_contents_all_raw (fromval
),
8828 TYPE_LENGTH (value_type (fromval
)));
8830 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8831 error (_("Unable to write siginfo"));
8834 static const struct lval_funcs siginfo_value_funcs
=
8840 /* Return a new value with the correct type for the siginfo object of
8841 the current thread using architecture GDBARCH. Return a void value
8842 if there's no object available. */
8844 static struct value
*
8845 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8848 if (target_has_stack
8849 && inferior_ptid
!= null_ptid
8850 && gdbarch_get_siginfo_type_p (gdbarch
))
8852 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8854 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8857 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8861 /* infcall_suspend_state contains state about the program itself like its
8862 registers and any signal it received when it last stopped.
8863 This state must be restored regardless of how the inferior function call
8864 ends (either successfully, or after it hits a breakpoint or signal)
8865 if the program is to properly continue where it left off. */
8867 class infcall_suspend_state
8870 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8871 once the inferior function call has finished. */
8872 infcall_suspend_state (struct gdbarch
*gdbarch
,
8873 const struct thread_info
*tp
,
8874 struct regcache
*regcache
)
8875 : m_thread_suspend (tp
->suspend
),
8876 m_registers (new readonly_detached_regcache (*regcache
))
8878 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8880 if (gdbarch_get_siginfo_type_p (gdbarch
))
8882 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8883 size_t len
= TYPE_LENGTH (type
);
8885 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8887 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8888 siginfo_data
.get (), 0, len
) != len
)
8890 /* Errors ignored. */
8891 siginfo_data
.reset (nullptr);
8897 m_siginfo_gdbarch
= gdbarch
;
8898 m_siginfo_data
= std::move (siginfo_data
);
8902 /* Return a pointer to the stored register state. */
8904 readonly_detached_regcache
*registers () const
8906 return m_registers
.get ();
8909 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8911 void restore (struct gdbarch
*gdbarch
,
8912 struct thread_info
*tp
,
8913 struct regcache
*regcache
) const
8915 tp
->suspend
= m_thread_suspend
;
8917 if (m_siginfo_gdbarch
== gdbarch
)
8919 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8921 /* Errors ignored. */
8922 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8923 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8926 /* The inferior can be gone if the user types "print exit(0)"
8927 (and perhaps other times). */
8928 if (target_has_execution
)
8929 /* NB: The register write goes through to the target. */
8930 regcache
->restore (registers ());
8934 /* How the current thread stopped before the inferior function call was
8936 struct thread_suspend_state m_thread_suspend
;
8938 /* The registers before the inferior function call was executed. */
8939 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8941 /* Format of SIGINFO_DATA or NULL if it is not present. */
8942 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8944 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8945 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8946 content would be invalid. */
8947 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8950 infcall_suspend_state_up
8951 save_infcall_suspend_state ()
8953 struct thread_info
*tp
= inferior_thread ();
8954 struct regcache
*regcache
= get_current_regcache ();
8955 struct gdbarch
*gdbarch
= regcache
->arch ();
8957 infcall_suspend_state_up inf_state
8958 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8960 /* Having saved the current state, adjust the thread state, discarding
8961 any stop signal information. The stop signal is not useful when
8962 starting an inferior function call, and run_inferior_call will not use
8963 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8964 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8969 /* Restore inferior session state to INF_STATE. */
8972 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8974 struct thread_info
*tp
= inferior_thread ();
8975 struct regcache
*regcache
= get_current_regcache ();
8976 struct gdbarch
*gdbarch
= regcache
->arch ();
8978 inf_state
->restore (gdbarch
, tp
, regcache
);
8979 discard_infcall_suspend_state (inf_state
);
8983 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8988 readonly_detached_regcache
*
8989 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8991 return inf_state
->registers ();
8994 /* infcall_control_state contains state regarding gdb's control of the
8995 inferior itself like stepping control. It also contains session state like
8996 the user's currently selected frame. */
8998 struct infcall_control_state
9000 struct thread_control_state thread_control
;
9001 struct inferior_control_state inferior_control
;
9004 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9005 int stopped_by_random_signal
= 0;
9007 /* ID if the selected frame when the inferior function call was made. */
9008 struct frame_id selected_frame_id
{};
9011 /* Save all of the information associated with the inferior<==>gdb
9014 infcall_control_state_up
9015 save_infcall_control_state ()
9017 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9018 struct thread_info
*tp
= inferior_thread ();
9019 struct inferior
*inf
= current_inferior ();
9021 inf_status
->thread_control
= tp
->control
;
9022 inf_status
->inferior_control
= inf
->control
;
9024 tp
->control
.step_resume_breakpoint
= NULL
;
9025 tp
->control
.exception_resume_breakpoint
= NULL
;
9027 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9028 chain. If caller's caller is walking the chain, they'll be happier if we
9029 hand them back the original chain when restore_infcall_control_state is
9031 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9034 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9035 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9037 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9043 restore_selected_frame (const frame_id
&fid
)
9045 frame_info
*frame
= frame_find_by_id (fid
);
9047 /* If inf_status->selected_frame_id is NULL, there was no previously
9051 warning (_("Unable to restore previously selected frame."));
9055 select_frame (frame
);
9058 /* Restore inferior session state to INF_STATUS. */
9061 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9063 struct thread_info
*tp
= inferior_thread ();
9064 struct inferior
*inf
= current_inferior ();
9066 if (tp
->control
.step_resume_breakpoint
)
9067 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9069 if (tp
->control
.exception_resume_breakpoint
)
9070 tp
->control
.exception_resume_breakpoint
->disposition
9071 = disp_del_at_next_stop
;
9073 /* Handle the bpstat_copy of the chain. */
9074 bpstat_clear (&tp
->control
.stop_bpstat
);
9076 tp
->control
= inf_status
->thread_control
;
9077 inf
->control
= inf_status
->inferior_control
;
9080 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9081 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9083 if (target_has_stack
)
9085 /* The point of the try/catch is that if the stack is clobbered,
9086 walking the stack might encounter a garbage pointer and
9087 error() trying to dereference it. */
9090 restore_selected_frame (inf_status
->selected_frame_id
);
9092 catch (const gdb_exception_error
&ex
)
9094 exception_fprintf (gdb_stderr
, ex
,
9095 "Unable to restore previously selected frame:\n");
9096 /* Error in restoring the selected frame. Select the
9098 select_frame (get_current_frame ());
9106 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9108 if (inf_status
->thread_control
.step_resume_breakpoint
)
9109 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9110 = disp_del_at_next_stop
;
9112 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9113 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9114 = disp_del_at_next_stop
;
9116 /* See save_infcall_control_state for info on stop_bpstat. */
9117 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9125 clear_exit_convenience_vars (void)
9127 clear_internalvar (lookup_internalvar ("_exitsignal"));
9128 clear_internalvar (lookup_internalvar ("_exitcode"));
9132 /* User interface for reverse debugging:
9133 Set exec-direction / show exec-direction commands
9134 (returns error unless target implements to_set_exec_direction method). */
9136 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9137 static const char exec_forward
[] = "forward";
9138 static const char exec_reverse
[] = "reverse";
9139 static const char *exec_direction
= exec_forward
;
9140 static const char *const exec_direction_names
[] = {
9147 set_exec_direction_func (const char *args
, int from_tty
,
9148 struct cmd_list_element
*cmd
)
9150 if (target_can_execute_reverse
)
9152 if (!strcmp (exec_direction
, exec_forward
))
9153 execution_direction
= EXEC_FORWARD
;
9154 else if (!strcmp (exec_direction
, exec_reverse
))
9155 execution_direction
= EXEC_REVERSE
;
9159 exec_direction
= exec_forward
;
9160 error (_("Target does not support this operation."));
9165 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9166 struct cmd_list_element
*cmd
, const char *value
)
9168 switch (execution_direction
) {
9170 fprintf_filtered (out
, _("Forward.\n"));
9173 fprintf_filtered (out
, _("Reverse.\n"));
9176 internal_error (__FILE__
, __LINE__
,
9177 _("bogus execution_direction value: %d"),
9178 (int) execution_direction
);
9183 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9184 struct cmd_list_element
*c
, const char *value
)
9186 fprintf_filtered (file
, _("Resuming the execution of threads "
9187 "of all processes is %s.\n"), value
);
9190 /* Implementation of `siginfo' variable. */
9192 static const struct internalvar_funcs siginfo_funcs
=
9199 /* Callback for infrun's target events source. This is marked when a
9200 thread has a pending status to process. */
9203 infrun_async_inferior_event_handler (gdb_client_data data
)
9205 inferior_event_handler (INF_REG_EVENT
);
9211 /* Verify that when two threads with the same ptid exist (from two different
9212 targets) and one of them changes ptid, we only update inferior_ptid if
9213 it is appropriate. */
9216 infrun_thread_ptid_changed ()
9218 gdbarch
*arch
= current_inferior ()->gdbarch
;
9220 /* The thread which inferior_ptid represents changes ptid. */
9222 scoped_restore_current_pspace_and_thread restore
;
9224 scoped_mock_context
<test_target_ops
> target1 (arch
);
9225 scoped_mock_context
<test_target_ops
> target2 (arch
);
9226 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9228 ptid_t
old_ptid (111, 222);
9229 ptid_t
new_ptid (111, 333);
9231 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9232 target1
.mock_thread
.ptid
= old_ptid
;
9233 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9234 target2
.mock_thread
.ptid
= old_ptid
;
9236 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9237 set_current_inferior (&target1
.mock_inferior
);
9239 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9241 gdb_assert (inferior_ptid
== new_ptid
);
9244 /* A thread with the same ptid as inferior_ptid, but from another target,
9247 scoped_restore_current_pspace_and_thread restore
;
9249 scoped_mock_context
<test_target_ops
> target1 (arch
);
9250 scoped_mock_context
<test_target_ops
> target2 (arch
);
9251 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9253 ptid_t
old_ptid (111, 222);
9254 ptid_t
new_ptid (111, 333);
9256 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9257 target1
.mock_thread
.ptid
= old_ptid
;
9258 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9259 target2
.mock_thread
.ptid
= old_ptid
;
9261 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9262 set_current_inferior (&target2
.mock_inferior
);
9264 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9266 gdb_assert (inferior_ptid
== old_ptid
);
9270 } /* namespace selftests */
9272 void _initialize_infrun ();
9274 _initialize_infrun ()
9276 struct cmd_list_element
*c
;
9278 /* Register extra event sources in the event loop. */
9279 infrun_async_inferior_event_token
9280 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9282 add_info ("signals", info_signals_command
, _("\
9283 What debugger does when program gets various signals.\n\
9284 Specify a signal as argument to print info on that signal only."));
9285 add_info_alias ("handle", "signals", 0);
9287 c
= add_com ("handle", class_run
, handle_command
, _("\
9288 Specify how to handle signals.\n\
9289 Usage: handle SIGNAL [ACTIONS]\n\
9290 Args are signals and actions to apply to those signals.\n\
9291 If no actions are specified, the current settings for the specified signals\n\
9292 will be displayed instead.\n\
9294 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9295 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9296 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9297 The special arg \"all\" is recognized to mean all signals except those\n\
9298 used by the debugger, typically SIGTRAP and SIGINT.\n\
9300 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9301 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9302 Stop means reenter debugger if this signal happens (implies print).\n\
9303 Print means print a message if this signal happens.\n\
9304 Pass means let program see this signal; otherwise program doesn't know.\n\
9305 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9306 Pass and Stop may be combined.\n\
9308 Multiple signals may be specified. Signal numbers and signal names\n\
9309 may be interspersed with actions, with the actions being performed for\n\
9310 all signals cumulatively specified."));
9311 set_cmd_completer (c
, handle_completer
);
9314 stop_command
= add_cmd ("stop", class_obscure
,
9315 not_just_help_class_command
, _("\
9316 There is no `stop' command, but you can set a hook on `stop'.\n\
9317 This allows you to set a list of commands to be run each time execution\n\
9318 of the program stops."), &cmdlist
);
9320 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9321 Set inferior debugging."), _("\
9322 Show inferior debugging."), _("\
9323 When non-zero, inferior specific debugging is enabled."),
9326 &setdebuglist
, &showdebuglist
);
9328 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9329 &debug_displaced
, _("\
9330 Set displaced stepping debugging."), _("\
9331 Show displaced stepping debugging."), _("\
9332 When non-zero, displaced stepping specific debugging is enabled."),
9334 show_debug_displaced
,
9335 &setdebuglist
, &showdebuglist
);
9337 add_setshow_boolean_cmd ("non-stop", no_class
,
9339 Set whether gdb controls the inferior in non-stop mode."), _("\
9340 Show whether gdb controls the inferior in non-stop mode."), _("\
9341 When debugging a multi-threaded program and this setting is\n\
9342 off (the default, also called all-stop mode), when one thread stops\n\
9343 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9344 all other threads in the program while you interact with the thread of\n\
9345 interest. When you continue or step a thread, you can allow the other\n\
9346 threads to run, or have them remain stopped, but while you inspect any\n\
9347 thread's state, all threads stop.\n\
9349 In non-stop mode, when one thread stops, other threads can continue\n\
9350 to run freely. You'll be able to step each thread independently,\n\
9351 leave it stopped or free to run as needed."),
9357 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9360 signal_print
[i
] = 1;
9361 signal_program
[i
] = 1;
9362 signal_catch
[i
] = 0;
9365 /* Signals caused by debugger's own actions should not be given to
9366 the program afterwards.
9368 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9369 explicitly specifies that it should be delivered to the target
9370 program. Typically, that would occur when a user is debugging a
9371 target monitor on a simulator: the target monitor sets a
9372 breakpoint; the simulator encounters this breakpoint and halts
9373 the simulation handing control to GDB; GDB, noting that the stop
9374 address doesn't map to any known breakpoint, returns control back
9375 to the simulator; the simulator then delivers the hardware
9376 equivalent of a GDB_SIGNAL_TRAP to the program being
9378 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9379 signal_program
[GDB_SIGNAL_INT
] = 0;
9381 /* Signals that are not errors should not normally enter the debugger. */
9382 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9383 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9384 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9385 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9386 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9387 signal_print
[GDB_SIGNAL_PROF
] = 0;
9388 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9389 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9390 signal_stop
[GDB_SIGNAL_IO
] = 0;
9391 signal_print
[GDB_SIGNAL_IO
] = 0;
9392 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9393 signal_print
[GDB_SIGNAL_POLL
] = 0;
9394 signal_stop
[GDB_SIGNAL_URG
] = 0;
9395 signal_print
[GDB_SIGNAL_URG
] = 0;
9396 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9397 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9398 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9399 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9401 /* These signals are used internally by user-level thread
9402 implementations. (See signal(5) on Solaris.) Like the above
9403 signals, a healthy program receives and handles them as part of
9404 its normal operation. */
9405 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9406 signal_print
[GDB_SIGNAL_LWP
] = 0;
9407 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9408 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9409 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9410 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9411 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9412 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9414 /* Update cached state. */
9415 signal_cache_update (-1);
9417 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9418 &stop_on_solib_events
, _("\
9419 Set stopping for shared library events."), _("\
9420 Show stopping for shared library events."), _("\
9421 If nonzero, gdb will give control to the user when the dynamic linker\n\
9422 notifies gdb of shared library events. The most common event of interest\n\
9423 to the user would be loading/unloading of a new library."),
9424 set_stop_on_solib_events
,
9425 show_stop_on_solib_events
,
9426 &setlist
, &showlist
);
9428 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9429 follow_fork_mode_kind_names
,
9430 &follow_fork_mode_string
, _("\
9431 Set debugger response to a program call of fork or vfork."), _("\
9432 Show debugger response to a program call of fork or vfork."), _("\
9433 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9434 parent - the original process is debugged after a fork\n\
9435 child - the new process is debugged after a fork\n\
9436 The unfollowed process will continue to run.\n\
9437 By default, the debugger will follow the parent process."),
9439 show_follow_fork_mode_string
,
9440 &setlist
, &showlist
);
9442 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9443 follow_exec_mode_names
,
9444 &follow_exec_mode_string
, _("\
9445 Set debugger response to a program call of exec."), _("\
9446 Show debugger response to a program call of exec."), _("\
9447 An exec call replaces the program image of a process.\n\
9449 follow-exec-mode can be:\n\
9451 new - the debugger creates a new inferior and rebinds the process\n\
9452 to this new inferior. The program the process was running before\n\
9453 the exec call can be restarted afterwards by restarting the original\n\
9456 same - the debugger keeps the process bound to the same inferior.\n\
9457 The new executable image replaces the previous executable loaded in\n\
9458 the inferior. Restarting the inferior after the exec call restarts\n\
9459 the executable the process was running after the exec call.\n\
9461 By default, the debugger will use the same inferior."),
9463 show_follow_exec_mode_string
,
9464 &setlist
, &showlist
);
9466 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9467 scheduler_enums
, &scheduler_mode
, _("\
9468 Set mode for locking scheduler during execution."), _("\
9469 Show mode for locking scheduler during execution."), _("\
9470 off == no locking (threads may preempt at any time)\n\
9471 on == full locking (no thread except the current thread may run)\n\
9472 This applies to both normal execution and replay mode.\n\
9473 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9474 In this mode, other threads may run during other commands.\n\
9475 This applies to both normal execution and replay mode.\n\
9476 replay == scheduler locked in replay mode and unlocked during normal execution."),
9477 set_schedlock_func
, /* traps on target vector */
9478 show_scheduler_mode
,
9479 &setlist
, &showlist
);
9481 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9482 Set mode for resuming threads of all processes."), _("\
9483 Show mode for resuming threads of all processes."), _("\
9484 When on, execution commands (such as 'continue' or 'next') resume all\n\
9485 threads of all processes. When off (which is the default), execution\n\
9486 commands only resume the threads of the current process. The set of\n\
9487 threads that are resumed is further refined by the scheduler-locking\n\
9488 mode (see help set scheduler-locking)."),
9490 show_schedule_multiple
,
9491 &setlist
, &showlist
);
9493 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9494 Set mode of the step operation."), _("\
9495 Show mode of the step operation."), _("\
9496 When set, doing a step over a function without debug line information\n\
9497 will stop at the first instruction of that function. Otherwise, the\n\
9498 function is skipped and the step command stops at a different source line."),
9500 show_step_stop_if_no_debug
,
9501 &setlist
, &showlist
);
9503 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9504 &can_use_displaced_stepping
, _("\
9505 Set debugger's willingness to use displaced stepping."), _("\
9506 Show debugger's willingness to use displaced stepping."), _("\
9507 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9508 supported by the target architecture. If off, gdb will not use displaced\n\
9509 stepping to step over breakpoints, even if such is supported by the target\n\
9510 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9511 if the target architecture supports it and non-stop mode is active, but will not\n\
9512 use it in all-stop mode (see help set non-stop)."),
9514 show_can_use_displaced_stepping
,
9515 &setlist
, &showlist
);
9517 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9518 &exec_direction
, _("Set direction of execution.\n\
9519 Options are 'forward' or 'reverse'."),
9520 _("Show direction of execution (forward/reverse)."),
9521 _("Tells gdb whether to execute forward or backward."),
9522 set_exec_direction_func
, show_exec_direction_func
,
9523 &setlist
, &showlist
);
9525 /* Set/show detach-on-fork: user-settable mode. */
9527 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9528 Set whether gdb will detach the child of a fork."), _("\
9529 Show whether gdb will detach the child of a fork."), _("\
9530 Tells gdb whether to detach the child of a fork."),
9531 NULL
, NULL
, &setlist
, &showlist
);
9533 /* Set/show disable address space randomization mode. */
9535 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9536 &disable_randomization
, _("\
9537 Set disabling of debuggee's virtual address space randomization."), _("\
9538 Show disabling of debuggee's virtual address space randomization."), _("\
9539 When this mode is on (which is the default), randomization of the virtual\n\
9540 address space is disabled. Standalone programs run with the randomization\n\
9541 enabled by default on some platforms."),
9542 &set_disable_randomization
,
9543 &show_disable_randomization
,
9544 &setlist
, &showlist
);
9546 /* ptid initializations */
9547 inferior_ptid
= null_ptid
;
9548 target_last_wait_ptid
= minus_one_ptid
;
9550 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9551 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9552 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9553 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9555 /* Explicitly create without lookup, since that tries to create a
9556 value with a void typed value, and when we get here, gdbarch
9557 isn't initialized yet. At this point, we're quite sure there
9558 isn't another convenience variable of the same name. */
9559 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9561 add_setshow_boolean_cmd ("observer", no_class
,
9562 &observer_mode_1
, _("\
9563 Set whether gdb controls the inferior in observer mode."), _("\
9564 Show whether gdb controls the inferior in observer mode."), _("\
9565 In observer mode, GDB can get data from the inferior, but not\n\
9566 affect its execution. Registers and memory may not be changed,\n\
9567 breakpoints may not be set, and the program cannot be interrupted\n\
9575 selftests::register_test ("infrun_thread_ptid_changed",
9576 selftests::infrun_thread_ptid_changed
);