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
3907 switch_to_target_no_thread (ecs
->target
);
3910 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3912 /* If an error happens while handling the event, propagate GDB's
3913 knowledge of the executing state to the frontend/user running
3915 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3916 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3918 /* Get executed before scoped_restore_current_thread above to apply
3919 still for the thread which has thrown the exception. */
3920 auto defer_bpstat_clear
3921 = make_scope_exit (bpstat_clear_actions
);
3922 auto defer_delete_threads
3923 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3925 /* Now figure out what to do with the result of the result. */
3926 handle_inferior_event (ecs
);
3928 if (!ecs
->wait_some_more
)
3930 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3931 int should_stop
= 1;
3932 struct thread_info
*thr
= ecs
->event_thread
;
3934 delete_just_stopped_threads_infrun_breakpoints ();
3938 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3940 if (thread_fsm
!= NULL
)
3941 should_stop
= thread_fsm
->should_stop (thr
);
3950 bool should_notify_stop
= true;
3953 clean_up_just_stopped_threads_fsms (ecs
);
3955 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3956 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3958 if (should_notify_stop
)
3960 /* We may not find an inferior if this was a process exit. */
3961 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3962 proceeded
= normal_stop ();
3967 inferior_event_handler (INF_EXEC_COMPLETE
);
3971 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3972 previously selected thread is gone. We have two
3973 choices - switch to no thread selected, or restore the
3974 previously selected thread (now exited). We chose the
3975 later, just because that's what GDB used to do. After
3976 this, "info threads" says "The current thread <Thread
3977 ID 2> has terminated." instead of "No thread
3981 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3982 restore_thread
.dont_restore ();
3986 defer_delete_threads
.release ();
3987 defer_bpstat_clear
.release ();
3989 /* No error, don't finish the thread states yet. */
3990 finish_state
.release ();
3992 /* This scope is used to ensure that readline callbacks are
3993 reinstalled here. */
3996 /* If a UI was in sync execution mode, and now isn't, restore its
3997 prompt (a synchronous execution command has finished, and we're
3998 ready for input). */
3999 all_uis_check_sync_execution_done ();
4002 && exec_done_display_p
4003 && (inferior_ptid
== null_ptid
4004 || inferior_thread ()->state
!= THREAD_RUNNING
))
4005 printf_unfiltered (_("completed.\n"));
4011 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4012 struct symtab_and_line sal
)
4014 /* This can be removed once this function no longer implicitly relies on the
4015 inferior_ptid value. */
4016 gdb_assert (inferior_ptid
== tp
->ptid
);
4018 tp
->control
.step_frame_id
= get_frame_id (frame
);
4019 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4021 tp
->current_symtab
= sal
.symtab
;
4022 tp
->current_line
= sal
.line
;
4025 /* Clear context switchable stepping state. */
4028 init_thread_stepping_state (struct thread_info
*tss
)
4030 tss
->stepped_breakpoint
= 0;
4031 tss
->stepping_over_breakpoint
= 0;
4032 tss
->stepping_over_watchpoint
= 0;
4033 tss
->step_after_step_resume_breakpoint
= 0;
4039 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4040 target_waitstatus status
)
4042 target_last_proc_target
= target
;
4043 target_last_wait_ptid
= ptid
;
4044 target_last_waitstatus
= status
;
4050 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4051 target_waitstatus
*status
)
4053 if (target
!= nullptr)
4054 *target
= target_last_proc_target
;
4055 if (ptid
!= nullptr)
4056 *ptid
= target_last_wait_ptid
;
4057 if (status
!= nullptr)
4058 *status
= target_last_waitstatus
;
4064 nullify_last_target_wait_ptid (void)
4066 target_last_proc_target
= nullptr;
4067 target_last_wait_ptid
= minus_one_ptid
;
4068 target_last_waitstatus
= {};
4071 /* Switch thread contexts. */
4074 context_switch (execution_control_state
*ecs
)
4076 if (ecs
->ptid
!= inferior_ptid
4077 && (inferior_ptid
== null_ptid
4078 || ecs
->event_thread
!= inferior_thread ()))
4080 infrun_debug_printf ("Switching context from %s to %s",
4081 target_pid_to_str (inferior_ptid
).c_str (),
4082 target_pid_to_str (ecs
->ptid
).c_str ());
4085 switch_to_thread (ecs
->event_thread
);
4088 /* If the target can't tell whether we've hit breakpoints
4089 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4090 check whether that could have been caused by a breakpoint. If so,
4091 adjust the PC, per gdbarch_decr_pc_after_break. */
4094 adjust_pc_after_break (struct thread_info
*thread
,
4095 struct target_waitstatus
*ws
)
4097 struct regcache
*regcache
;
4098 struct gdbarch
*gdbarch
;
4099 CORE_ADDR breakpoint_pc
, decr_pc
;
4101 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4102 we aren't, just return.
4104 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4105 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4106 implemented by software breakpoints should be handled through the normal
4109 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4110 different signals (SIGILL or SIGEMT for instance), but it is less
4111 clear where the PC is pointing afterwards. It may not match
4112 gdbarch_decr_pc_after_break. I don't know any specific target that
4113 generates these signals at breakpoints (the code has been in GDB since at
4114 least 1992) so I can not guess how to handle them here.
4116 In earlier versions of GDB, a target with
4117 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4118 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4119 target with both of these set in GDB history, and it seems unlikely to be
4120 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4122 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4125 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4128 /* In reverse execution, when a breakpoint is hit, the instruction
4129 under it has already been de-executed. The reported PC always
4130 points at the breakpoint address, so adjusting it further would
4131 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4134 B1 0x08000000 : INSN1
4135 B2 0x08000001 : INSN2
4137 PC -> 0x08000003 : INSN4
4139 Say you're stopped at 0x08000003 as above. Reverse continuing
4140 from that point should hit B2 as below. Reading the PC when the
4141 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4142 been de-executed already.
4144 B1 0x08000000 : INSN1
4145 B2 PC -> 0x08000001 : INSN2
4149 We can't apply the same logic as for forward execution, because
4150 we would wrongly adjust the PC to 0x08000000, since there's a
4151 breakpoint at PC - 1. We'd then report a hit on B1, although
4152 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4154 if (execution_direction
== EXEC_REVERSE
)
4157 /* If the target can tell whether the thread hit a SW breakpoint,
4158 trust it. Targets that can tell also adjust the PC
4160 if (target_supports_stopped_by_sw_breakpoint ())
4163 /* Note that relying on whether a breakpoint is planted in memory to
4164 determine this can fail. E.g,. the breakpoint could have been
4165 removed since. Or the thread could have been told to step an
4166 instruction the size of a breakpoint instruction, and only
4167 _after_ was a breakpoint inserted at its address. */
4169 /* If this target does not decrement the PC after breakpoints, then
4170 we have nothing to do. */
4171 regcache
= get_thread_regcache (thread
);
4172 gdbarch
= regcache
->arch ();
4174 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4178 const address_space
*aspace
= regcache
->aspace ();
4180 /* Find the location where (if we've hit a breakpoint) the
4181 breakpoint would be. */
4182 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4184 /* If the target can't tell whether a software breakpoint triggered,
4185 fallback to figuring it out based on breakpoints we think were
4186 inserted in the target, and on whether the thread was stepped or
4189 /* Check whether there actually is a software breakpoint inserted at
4192 If in non-stop mode, a race condition is possible where we've
4193 removed a breakpoint, but stop events for that breakpoint were
4194 already queued and arrive later. To suppress those spurious
4195 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4196 and retire them after a number of stop events are reported. Note
4197 this is an heuristic and can thus get confused. The real fix is
4198 to get the "stopped by SW BP and needs adjustment" info out of
4199 the target/kernel (and thus never reach here; see above). */
4200 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4201 || (target_is_non_stop_p ()
4202 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4204 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4206 if (record_full_is_used ())
4207 restore_operation_disable
.emplace
4208 (record_full_gdb_operation_disable_set ());
4210 /* When using hardware single-step, a SIGTRAP is reported for both
4211 a completed single-step and a software breakpoint. Need to
4212 differentiate between the two, as the latter needs adjusting
4213 but the former does not.
4215 The SIGTRAP can be due to a completed hardware single-step only if
4216 - we didn't insert software single-step breakpoints
4217 - this thread is currently being stepped
4219 If any of these events did not occur, we must have stopped due
4220 to hitting a software breakpoint, and have to back up to the
4223 As a special case, we could have hardware single-stepped a
4224 software breakpoint. In this case (prev_pc == breakpoint_pc),
4225 we also need to back up to the breakpoint address. */
4227 if (thread_has_single_step_breakpoints_set (thread
)
4228 || !currently_stepping (thread
)
4229 || (thread
->stepped_breakpoint
4230 && thread
->prev_pc
== breakpoint_pc
))
4231 regcache_write_pc (regcache
, breakpoint_pc
);
4236 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4238 for (frame
= get_prev_frame (frame
);
4240 frame
= get_prev_frame (frame
))
4242 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4244 if (get_frame_type (frame
) != INLINE_FRAME
)
4251 /* Look for an inline frame that is marked for skip.
4252 If PREV_FRAME is TRUE start at the previous frame,
4253 otherwise start at the current frame. Stop at the
4254 first non-inline frame, or at the frame where the
4258 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4260 struct frame_info
*frame
= get_current_frame ();
4263 frame
= get_prev_frame (frame
);
4265 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4267 const char *fn
= NULL
;
4268 symtab_and_line sal
;
4271 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4273 if (get_frame_type (frame
) != INLINE_FRAME
)
4276 sal
= find_frame_sal (frame
);
4277 sym
= get_frame_function (frame
);
4280 fn
= sym
->print_name ();
4283 && function_name_is_marked_for_skip (fn
, sal
))
4290 /* If the event thread has the stop requested flag set, pretend it
4291 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4295 handle_stop_requested (struct execution_control_state
*ecs
)
4297 if (ecs
->event_thread
->stop_requested
)
4299 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4300 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4301 handle_signal_stop (ecs
);
4307 /* Auxiliary function that handles syscall entry/return events.
4308 It returns 1 if the inferior should keep going (and GDB
4309 should ignore the event), or 0 if the event deserves to be
4313 handle_syscall_event (struct execution_control_state
*ecs
)
4315 struct regcache
*regcache
;
4318 context_switch (ecs
);
4320 regcache
= get_thread_regcache (ecs
->event_thread
);
4321 syscall_number
= ecs
->ws
.value
.syscall_number
;
4322 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4324 if (catch_syscall_enabled () > 0
4325 && catching_syscall_number (syscall_number
) > 0)
4327 infrun_debug_printf ("syscall number=%d", syscall_number
);
4329 ecs
->event_thread
->control
.stop_bpstat
4330 = bpstat_stop_status (regcache
->aspace (),
4331 ecs
->event_thread
->suspend
.stop_pc
,
4332 ecs
->event_thread
, &ecs
->ws
);
4334 if (handle_stop_requested (ecs
))
4337 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4339 /* Catchpoint hit. */
4344 if (handle_stop_requested (ecs
))
4347 /* If no catchpoint triggered for this, then keep going. */
4352 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4355 fill_in_stop_func (struct gdbarch
*gdbarch
,
4356 struct execution_control_state
*ecs
)
4358 if (!ecs
->stop_func_filled_in
)
4361 const general_symbol_info
*gsi
;
4363 /* Don't care about return value; stop_func_start and stop_func_name
4364 will both be 0 if it doesn't work. */
4365 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4367 &ecs
->stop_func_start
,
4368 &ecs
->stop_func_end
,
4370 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4372 /* The call to find_pc_partial_function, above, will set
4373 stop_func_start and stop_func_end to the start and end
4374 of the range containing the stop pc. If this range
4375 contains the entry pc for the block (which is always the
4376 case for contiguous blocks), advance stop_func_start past
4377 the function's start offset and entrypoint. Note that
4378 stop_func_start is NOT advanced when in a range of a
4379 non-contiguous block that does not contain the entry pc. */
4380 if (block
!= nullptr
4381 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4382 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4384 ecs
->stop_func_start
4385 += gdbarch_deprecated_function_start_offset (gdbarch
);
4387 if (gdbarch_skip_entrypoint_p (gdbarch
))
4388 ecs
->stop_func_start
4389 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4392 ecs
->stop_func_filled_in
= 1;
4397 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4399 static enum stop_kind
4400 get_inferior_stop_soon (execution_control_state
*ecs
)
4402 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4404 gdb_assert (inf
!= NULL
);
4405 return inf
->control
.stop_soon
;
4408 /* Poll for one event out of the current target. Store the resulting
4409 waitstatus in WS, and return the event ptid. Does not block. */
4412 poll_one_curr_target (struct target_waitstatus
*ws
)
4416 overlay_cache_invalid
= 1;
4418 /* Flush target cache before starting to handle each event.
4419 Target was running and cache could be stale. This is just a
4420 heuristic. Running threads may modify target memory, but we
4421 don't get any event. */
4422 target_dcache_invalidate ();
4424 if (deprecated_target_wait_hook
)
4425 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4427 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4430 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4435 /* An event reported by wait_one. */
4437 struct wait_one_event
4439 /* The target the event came out of. */
4440 process_stratum_target
*target
;
4442 /* The PTID the event was for. */
4445 /* The waitstatus. */
4446 target_waitstatus ws
;
4449 /* Wait for one event out of any target. */
4451 static wait_one_event
4456 for (inferior
*inf
: all_inferiors ())
4458 process_stratum_target
*target
= inf
->process_target ();
4460 || !target
->is_async_p ()
4461 || !target
->threads_executing
)
4464 switch_to_inferior_no_thread (inf
);
4466 wait_one_event event
;
4467 event
.target
= target
;
4468 event
.ptid
= poll_one_curr_target (&event
.ws
);
4470 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4472 /* If nothing is resumed, remove the target from the
4476 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4480 /* Block waiting for some event. */
4487 for (inferior
*inf
: all_inferiors ())
4489 process_stratum_target
*target
= inf
->process_target ();
4491 || !target
->is_async_p ()
4492 || !target
->threads_executing
)
4495 int fd
= target
->async_wait_fd ();
4496 FD_SET (fd
, &readfds
);
4503 /* No waitable targets left. All must be stopped. */
4504 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4509 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4515 perror_with_name ("interruptible_select");
4520 /* Save the thread's event and stop reason to process it later. */
4523 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4525 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4526 target_waitstatus_to_string (ws
).c_str (),
4531 /* Record for later. */
4532 tp
->suspend
.waitstatus
= *ws
;
4533 tp
->suspend
.waitstatus_pending_p
= 1;
4535 struct regcache
*regcache
= get_thread_regcache (tp
);
4536 const address_space
*aspace
= regcache
->aspace ();
4538 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4539 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4541 CORE_ADDR pc
= regcache_read_pc (regcache
);
4543 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4545 scoped_restore_current_thread restore_thread
;
4546 switch_to_thread (tp
);
4548 if (target_stopped_by_watchpoint ())
4550 tp
->suspend
.stop_reason
4551 = TARGET_STOPPED_BY_WATCHPOINT
;
4553 else if (target_supports_stopped_by_sw_breakpoint ()
4554 && target_stopped_by_sw_breakpoint ())
4556 tp
->suspend
.stop_reason
4557 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4559 else if (target_supports_stopped_by_hw_breakpoint ()
4560 && target_stopped_by_hw_breakpoint ())
4562 tp
->suspend
.stop_reason
4563 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4565 else if (!target_supports_stopped_by_hw_breakpoint ()
4566 && hardware_breakpoint_inserted_here_p (aspace
,
4569 tp
->suspend
.stop_reason
4570 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4572 else if (!target_supports_stopped_by_sw_breakpoint ()
4573 && software_breakpoint_inserted_here_p (aspace
,
4576 tp
->suspend
.stop_reason
4577 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4579 else if (!thread_has_single_step_breakpoints_set (tp
)
4580 && currently_stepping (tp
))
4582 tp
->suspend
.stop_reason
4583 = TARGET_STOPPED_BY_SINGLE_STEP
;
4588 /* Mark the non-executing threads accordingly. In all-stop, all
4589 threads of all processes are stopped when we get any event
4590 reported. In non-stop mode, only the event thread stops. */
4593 mark_non_executing_threads (process_stratum_target
*target
,
4595 struct target_waitstatus ws
)
4599 if (!target_is_non_stop_p ())
4600 mark_ptid
= minus_one_ptid
;
4601 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4602 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4604 /* If we're handling a process exit in non-stop mode, even
4605 though threads haven't been deleted yet, one would think
4606 that there is nothing to do, as threads of the dead process
4607 will be soon deleted, and threads of any other process were
4608 left running. However, on some targets, threads survive a
4609 process exit event. E.g., for the "checkpoint" command,
4610 when the current checkpoint/fork exits, linux-fork.c
4611 automatically switches to another fork from within
4612 target_mourn_inferior, by associating the same
4613 inferior/thread to another fork. We haven't mourned yet at
4614 this point, but we must mark any threads left in the
4615 process as not-executing so that finish_thread_state marks
4616 them stopped (in the user's perspective) if/when we present
4617 the stop to the user. */
4618 mark_ptid
= ptid_t (event_ptid
.pid ());
4621 mark_ptid
= event_ptid
;
4623 set_executing (target
, mark_ptid
, false);
4625 /* Likewise the resumed flag. */
4626 set_resumed (target
, mark_ptid
, false);
4632 stop_all_threads (void)
4634 /* We may need multiple passes to discover all threads. */
4638 gdb_assert (exists_non_stop_target ());
4640 infrun_debug_printf ("starting");
4642 scoped_restore_current_thread restore_thread
;
4644 /* Enable thread events of all targets. */
4645 for (auto *target
: all_non_exited_process_targets ())
4647 switch_to_target_no_thread (target
);
4648 target_thread_events (true);
4653 /* Disable thread events of all targets. */
4654 for (auto *target
: all_non_exited_process_targets ())
4656 switch_to_target_no_thread (target
);
4657 target_thread_events (false);
4660 /* Use infrun_debug_printf_1 directly to get a meaningful function
4663 infrun_debug_printf_1 ("stop_all_threads", "done");
4666 /* Request threads to stop, and then wait for the stops. Because
4667 threads we already know about can spawn more threads while we're
4668 trying to stop them, and we only learn about new threads when we
4669 update the thread list, do this in a loop, and keep iterating
4670 until two passes find no threads that need to be stopped. */
4671 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4673 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4676 int waits_needed
= 0;
4678 for (auto *target
: all_non_exited_process_targets ())
4680 switch_to_target_no_thread (target
);
4681 update_thread_list ();
4684 /* Go through all threads looking for threads that we need
4685 to tell the target to stop. */
4686 for (thread_info
*t
: all_non_exited_threads ())
4688 /* For a single-target setting with an all-stop target,
4689 we would not even arrive here. For a multi-target
4690 setting, until GDB is able to handle a mixture of
4691 all-stop and non-stop targets, simply skip all-stop
4692 targets' threads. This should be fine due to the
4693 protection of 'check_multi_target_resumption'. */
4695 switch_to_thread_no_regs (t
);
4696 if (!target_is_non_stop_p ())
4701 /* If already stopping, don't request a stop again.
4702 We just haven't seen the notification yet. */
4703 if (!t
->stop_requested
)
4705 infrun_debug_printf (" %s executing, need stop",
4706 target_pid_to_str (t
->ptid
).c_str ());
4707 target_stop (t
->ptid
);
4708 t
->stop_requested
= 1;
4712 infrun_debug_printf (" %s executing, already stopping",
4713 target_pid_to_str (t
->ptid
).c_str ());
4716 if (t
->stop_requested
)
4721 infrun_debug_printf (" %s not executing",
4722 target_pid_to_str (t
->ptid
).c_str ());
4724 /* The thread may be not executing, but still be
4725 resumed with a pending status to process. */
4730 if (waits_needed
== 0)
4733 /* If we find new threads on the second iteration, restart
4734 over. We want to see two iterations in a row with all
4739 for (int i
= 0; i
< waits_needed
; i
++)
4741 wait_one_event event
= wait_one ();
4744 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4745 target_pid_to_str (event
.ptid
).c_str ());
4747 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4749 /* All resumed threads exited. */
4752 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4753 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4754 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4756 /* One thread/process exited/signalled. */
4758 thread_info
*t
= nullptr;
4760 /* The target may have reported just a pid. If so, try
4761 the first non-exited thread. */
4762 if (event
.ptid
.is_pid ())
4764 int pid
= event
.ptid
.pid ();
4765 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4766 for (thread_info
*tp
: inf
->non_exited_threads ())
4772 /* If there is no available thread, the event would
4773 have to be appended to a per-inferior event list,
4774 which does not exist (and if it did, we'd have
4775 to adjust run control command to be able to
4776 resume such an inferior). We assert here instead
4777 of going into an infinite loop. */
4778 gdb_assert (t
!= nullptr);
4781 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4785 t
= find_thread_ptid (event
.target
, event
.ptid
);
4786 /* Check if this is the first time we see this thread.
4787 Don't bother adding if it individually exited. */
4789 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4790 t
= add_thread (event
.target
, event
.ptid
);
4795 /* Set the threads as non-executing to avoid
4796 another stop attempt on them. */
4797 switch_to_thread_no_regs (t
);
4798 mark_non_executing_threads (event
.target
, event
.ptid
,
4800 save_waitstatus (t
, &event
.ws
);
4801 t
->stop_requested
= false;
4806 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4808 t
= add_thread (event
.target
, event
.ptid
);
4810 t
->stop_requested
= 0;
4813 t
->control
.may_range_step
= 0;
4815 /* This may be the first time we see the inferior report
4817 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4818 if (inf
->needs_setup
)
4820 switch_to_thread_no_regs (t
);
4824 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4825 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4827 /* We caught the event that we intended to catch, so
4828 there's no event pending. */
4829 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4830 t
->suspend
.waitstatus_pending_p
= 0;
4832 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4834 /* Add it back to the step-over queue. */
4836 ("displaced-step of %s canceled: adding back to "
4837 "the step-over queue",
4838 target_pid_to_str (t
->ptid
).c_str ());
4840 t
->control
.trap_expected
= 0;
4841 thread_step_over_chain_enqueue (t
);
4846 enum gdb_signal sig
;
4847 struct regcache
*regcache
;
4850 ("target_wait %s, saving status for %d.%ld.%ld",
4851 target_waitstatus_to_string (&event
.ws
).c_str (),
4852 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4854 /* Record for later. */
4855 save_waitstatus (t
, &event
.ws
);
4857 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4858 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4860 if (displaced_step_fixup (t
, sig
) < 0)
4862 /* Add it back to the step-over queue. */
4863 t
->control
.trap_expected
= 0;
4864 thread_step_over_chain_enqueue (t
);
4867 regcache
= get_thread_regcache (t
);
4868 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4870 infrun_debug_printf ("saved stop_pc=%s for %s "
4871 "(currently_stepping=%d)",
4872 paddress (target_gdbarch (),
4873 t
->suspend
.stop_pc
),
4874 target_pid_to_str (t
->ptid
).c_str (),
4875 currently_stepping (t
));
4883 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4886 handle_no_resumed (struct execution_control_state
*ecs
)
4888 if (target_can_async_p ())
4892 for (ui
*ui
: all_uis ())
4894 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4902 /* There were no unwaited-for children left in the target, but,
4903 we're not synchronously waiting for events either. Just
4906 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4907 prepare_to_wait (ecs
);
4912 /* Otherwise, if we were running a synchronous execution command, we
4913 may need to cancel it and give the user back the terminal.
4915 In non-stop mode, the target can't tell whether we've already
4916 consumed previous stop events, so it can end up sending us a
4917 no-resumed event like so:
4919 #0 - thread 1 is left stopped
4921 #1 - thread 2 is resumed and hits breakpoint
4922 -> TARGET_WAITKIND_STOPPED
4924 #2 - thread 3 is resumed and exits
4925 this is the last resumed thread, so
4926 -> TARGET_WAITKIND_NO_RESUMED
4928 #3 - gdb processes stop for thread 2 and decides to re-resume
4931 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4932 thread 2 is now resumed, so the event should be ignored.
4934 IOW, if the stop for thread 2 doesn't end a foreground command,
4935 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4936 event. But it could be that the event meant that thread 2 itself
4937 (or whatever other thread was the last resumed thread) exited.
4939 To address this we refresh the thread list and check whether we
4940 have resumed threads _now_. In the example above, this removes
4941 thread 3 from the thread list. If thread 2 was re-resumed, we
4942 ignore this event. If we find no thread resumed, then we cancel
4943 the synchronous command and show "no unwaited-for " to the
4946 inferior
*curr_inf
= current_inferior ();
4948 scoped_restore_current_thread restore_thread
;
4950 for (auto *target
: all_non_exited_process_targets ())
4952 switch_to_target_no_thread (target
);
4953 update_thread_list ();
4958 - the current target has no thread executing, and
4959 - the current inferior is native, and
4960 - the current inferior is the one which has the terminal, and
4963 then a Ctrl-C from this point on would remain stuck in the
4964 kernel, until a thread resumes and dequeues it. That would
4965 result in the GDB CLI not reacting to Ctrl-C, not able to
4966 interrupt the program. To address this, if the current inferior
4967 no longer has any thread executing, we give the terminal to some
4968 other inferior that has at least one thread executing. */
4969 bool swap_terminal
= true;
4971 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4972 whether to report it to the user. */
4973 bool ignore_event
= false;
4975 for (thread_info
*thread
: all_non_exited_threads ())
4977 if (swap_terminal
&& thread
->executing
)
4979 if (thread
->inf
!= curr_inf
)
4981 target_terminal::ours ();
4983 switch_to_thread (thread
);
4984 target_terminal::inferior ();
4986 swap_terminal
= false;
4990 && (thread
->executing
4991 || thread
->suspend
.waitstatus_pending_p
))
4993 /* Either there were no unwaited-for children left in the
4994 target at some point, but there are now, or some target
4995 other than the eventing one has unwaited-for children
4996 left. Just ignore. */
4997 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
4998 "(ignoring: found resumed)");
5000 ignore_event
= true;
5003 if (ignore_event
&& !swap_terminal
)
5009 switch_to_inferior_no_thread (curr_inf
);
5010 prepare_to_wait (ecs
);
5014 /* Go ahead and report the event. */
5018 /* Given an execution control state that has been freshly filled in by
5019 an event from the inferior, figure out what it means and take
5022 The alternatives are:
5024 1) stop_waiting and return; to really stop and return to the
5027 2) keep_going and return; to wait for the next event (set
5028 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5032 handle_inferior_event (struct execution_control_state
*ecs
)
5034 /* Make sure that all temporary struct value objects that were
5035 created during the handling of the event get deleted at the
5037 scoped_value_mark free_values
;
5039 enum stop_kind stop_soon
;
5041 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5043 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5045 /* We had an event in the inferior, but we are not interested in
5046 handling it at this level. The lower layers have already
5047 done what needs to be done, if anything.
5049 One of the possible circumstances for this is when the
5050 inferior produces output for the console. The inferior has
5051 not stopped, and we are ignoring the event. Another possible
5052 circumstance is any event which the lower level knows will be
5053 reported multiple times without an intervening resume. */
5054 prepare_to_wait (ecs
);
5058 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5060 prepare_to_wait (ecs
);
5064 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5065 && handle_no_resumed (ecs
))
5068 /* Cache the last target/ptid/waitstatus. */
5069 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5071 /* Always clear state belonging to the previous time we stopped. */
5072 stop_stack_dummy
= STOP_NONE
;
5074 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5076 /* No unwaited-for children left. IOW, all resumed children
5078 stop_print_frame
= 0;
5083 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5084 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5086 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5087 /* If it's a new thread, add it to the thread database. */
5088 if (ecs
->event_thread
== NULL
)
5089 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5091 /* Disable range stepping. If the next step request could use a
5092 range, this will be end up re-enabled then. */
5093 ecs
->event_thread
->control
.may_range_step
= 0;
5096 /* Dependent on valid ECS->EVENT_THREAD. */
5097 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5099 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5100 reinit_frame_cache ();
5102 breakpoint_retire_moribund ();
5104 /* First, distinguish signals caused by the debugger from signals
5105 that have to do with the program's own actions. Note that
5106 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5107 on the operating system version. Here we detect when a SIGILL or
5108 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5109 something similar for SIGSEGV, since a SIGSEGV will be generated
5110 when we're trying to execute a breakpoint instruction on a
5111 non-executable stack. This happens for call dummy breakpoints
5112 for architectures like SPARC that place call dummies on the
5114 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5115 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5116 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5117 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5119 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5121 if (breakpoint_inserted_here_p (regcache
->aspace (),
5122 regcache_read_pc (regcache
)))
5124 infrun_debug_printf ("Treating signal as SIGTRAP");
5125 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5129 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5131 switch (ecs
->ws
.kind
)
5133 case TARGET_WAITKIND_LOADED
:
5134 context_switch (ecs
);
5135 /* Ignore gracefully during startup of the inferior, as it might
5136 be the shell which has just loaded some objects, otherwise
5137 add the symbols for the newly loaded objects. Also ignore at
5138 the beginning of an attach or remote session; we will query
5139 the full list of libraries once the connection is
5142 stop_soon
= get_inferior_stop_soon (ecs
);
5143 if (stop_soon
== NO_STOP_QUIETLY
)
5145 struct regcache
*regcache
;
5147 regcache
= get_thread_regcache (ecs
->event_thread
);
5149 handle_solib_event ();
5151 ecs
->event_thread
->control
.stop_bpstat
5152 = bpstat_stop_status (regcache
->aspace (),
5153 ecs
->event_thread
->suspend
.stop_pc
,
5154 ecs
->event_thread
, &ecs
->ws
);
5156 if (handle_stop_requested (ecs
))
5159 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5161 /* A catchpoint triggered. */
5162 process_event_stop_test (ecs
);
5166 /* If requested, stop when the dynamic linker notifies
5167 gdb of events. This allows the user to get control
5168 and place breakpoints in initializer routines for
5169 dynamically loaded objects (among other things). */
5170 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5171 if (stop_on_solib_events
)
5173 /* Make sure we print "Stopped due to solib-event" in
5175 stop_print_frame
= 1;
5182 /* If we are skipping through a shell, or through shared library
5183 loading that we aren't interested in, resume the program. If
5184 we're running the program normally, also resume. */
5185 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5187 /* Loading of shared libraries might have changed breakpoint
5188 addresses. Make sure new breakpoints are inserted. */
5189 if (stop_soon
== NO_STOP_QUIETLY
)
5190 insert_breakpoints ();
5191 resume (GDB_SIGNAL_0
);
5192 prepare_to_wait (ecs
);
5196 /* But stop if we're attaching or setting up a remote
5198 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5199 || stop_soon
== STOP_QUIETLY_REMOTE
)
5201 infrun_debug_printf ("quietly stopped");
5206 internal_error (__FILE__
, __LINE__
,
5207 _("unhandled stop_soon: %d"), (int) stop_soon
);
5209 case TARGET_WAITKIND_SPURIOUS
:
5210 if (handle_stop_requested (ecs
))
5212 context_switch (ecs
);
5213 resume (GDB_SIGNAL_0
);
5214 prepare_to_wait (ecs
);
5217 case TARGET_WAITKIND_THREAD_CREATED
:
5218 if (handle_stop_requested (ecs
))
5220 context_switch (ecs
);
5221 if (!switch_back_to_stepped_thread (ecs
))
5225 case TARGET_WAITKIND_EXITED
:
5226 case TARGET_WAITKIND_SIGNALLED
:
5228 /* Depending on the system, ecs->ptid may point to a thread or
5229 to a process. On some targets, target_mourn_inferior may
5230 need to have access to the just-exited thread. That is the
5231 case of GNU/Linux's "checkpoint" support, for example.
5232 Call the switch_to_xxx routine as appropriate. */
5233 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5235 switch_to_thread (thr
);
5238 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5239 switch_to_inferior_no_thread (inf
);
5242 handle_vfork_child_exec_or_exit (0);
5243 target_terminal::ours (); /* Must do this before mourn anyway. */
5245 /* Clearing any previous state of convenience variables. */
5246 clear_exit_convenience_vars ();
5248 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5250 /* Record the exit code in the convenience variable $_exitcode, so
5251 that the user can inspect this again later. */
5252 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5253 (LONGEST
) ecs
->ws
.value
.integer
);
5255 /* Also record this in the inferior itself. */
5256 current_inferior ()->has_exit_code
= 1;
5257 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5259 /* Support the --return-child-result option. */
5260 return_child_result_value
= ecs
->ws
.value
.integer
;
5262 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5266 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5268 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5270 /* Set the value of the internal variable $_exitsignal,
5271 which holds the signal uncaught by the inferior. */
5272 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5273 gdbarch_gdb_signal_to_target (gdbarch
,
5274 ecs
->ws
.value
.sig
));
5278 /* We don't have access to the target's method used for
5279 converting between signal numbers (GDB's internal
5280 representation <-> target's representation).
5281 Therefore, we cannot do a good job at displaying this
5282 information to the user. It's better to just warn
5283 her about it (if infrun debugging is enabled), and
5285 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5289 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5292 gdb_flush (gdb_stdout
);
5293 target_mourn_inferior (inferior_ptid
);
5294 stop_print_frame
= 0;
5298 case TARGET_WAITKIND_FORKED
:
5299 case TARGET_WAITKIND_VFORKED
:
5300 /* Check whether the inferior is displaced stepping. */
5302 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5303 struct gdbarch
*gdbarch
= regcache
->arch ();
5305 /* If checking displaced stepping is supported, and thread
5306 ecs->ptid is displaced stepping. */
5307 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5309 struct inferior
*parent_inf
5310 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5311 struct regcache
*child_regcache
;
5312 CORE_ADDR parent_pc
;
5314 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5316 struct displaced_step_inferior_state
*displaced
5317 = get_displaced_stepping_state (parent_inf
);
5319 /* Restore scratch pad for child process. */
5320 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5323 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5324 indicating that the displaced stepping of syscall instruction
5325 has been done. Perform cleanup for parent process here. Note
5326 that this operation also cleans up the child process for vfork,
5327 because their pages are shared. */
5328 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5329 /* Start a new step-over in another thread if there's one
5333 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5334 the child's PC is also within the scratchpad. Set the child's PC
5335 to the parent's PC value, which has already been fixed up.
5336 FIXME: we use the parent's aspace here, although we're touching
5337 the child, because the child hasn't been added to the inferior
5338 list yet at this point. */
5341 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5342 ecs
->ws
.value
.related_pid
,
5344 parent_inf
->aspace
);
5345 /* Read PC value of parent process. */
5346 parent_pc
= regcache_read_pc (regcache
);
5348 if (debug_displaced
)
5349 fprintf_unfiltered (gdb_stdlog
,
5350 "displaced: write child pc from %s to %s\n",
5352 regcache_read_pc (child_regcache
)),
5353 paddress (gdbarch
, parent_pc
));
5355 regcache_write_pc (child_regcache
, parent_pc
);
5359 context_switch (ecs
);
5361 /* Immediately detach breakpoints from the child before there's
5362 any chance of letting the user delete breakpoints from the
5363 breakpoint lists. If we don't do this early, it's easy to
5364 leave left over traps in the child, vis: "break foo; catch
5365 fork; c; <fork>; del; c; <child calls foo>". We only follow
5366 the fork on the last `continue', and by that time the
5367 breakpoint at "foo" is long gone from the breakpoint table.
5368 If we vforked, then we don't need to unpatch here, since both
5369 parent and child are sharing the same memory pages; we'll
5370 need to unpatch at follow/detach time instead to be certain
5371 that new breakpoints added between catchpoint hit time and
5372 vfork follow are detached. */
5373 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5375 /* This won't actually modify the breakpoint list, but will
5376 physically remove the breakpoints from the child. */
5377 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5380 delete_just_stopped_threads_single_step_breakpoints ();
5382 /* In case the event is caught by a catchpoint, remember that
5383 the event is to be followed at the next resume of the thread,
5384 and not immediately. */
5385 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5387 ecs
->event_thread
->suspend
.stop_pc
5388 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5390 ecs
->event_thread
->control
.stop_bpstat
5391 = bpstat_stop_status (get_current_regcache ()->aspace (),
5392 ecs
->event_thread
->suspend
.stop_pc
,
5393 ecs
->event_thread
, &ecs
->ws
);
5395 if (handle_stop_requested (ecs
))
5398 /* If no catchpoint triggered for this, then keep going. Note
5399 that we're interested in knowing the bpstat actually causes a
5400 stop, not just if it may explain the signal. Software
5401 watchpoints, for example, always appear in the bpstat. */
5402 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5405 = (follow_fork_mode_string
== follow_fork_mode_child
);
5407 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5409 process_stratum_target
*targ
5410 = ecs
->event_thread
->inf
->process_target ();
5412 bool should_resume
= follow_fork ();
5414 /* Note that one of these may be an invalid pointer,
5415 depending on detach_fork. */
5416 thread_info
*parent
= ecs
->event_thread
;
5418 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5420 /* At this point, the parent is marked running, and the
5421 child is marked stopped. */
5423 /* If not resuming the parent, mark it stopped. */
5424 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5425 parent
->set_running (false);
5427 /* If resuming the child, mark it running. */
5428 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5429 child
->set_running (true);
5431 /* In non-stop mode, also resume the other branch. */
5432 if (!detach_fork
&& (non_stop
5433 || (sched_multi
&& target_is_non_stop_p ())))
5436 switch_to_thread (parent
);
5438 switch_to_thread (child
);
5440 ecs
->event_thread
= inferior_thread ();
5441 ecs
->ptid
= inferior_ptid
;
5446 switch_to_thread (child
);
5448 switch_to_thread (parent
);
5450 ecs
->event_thread
= inferior_thread ();
5451 ecs
->ptid
= inferior_ptid
;
5459 process_event_stop_test (ecs
);
5462 case TARGET_WAITKIND_VFORK_DONE
:
5463 /* Done with the shared memory region. Re-insert breakpoints in
5464 the parent, and keep going. */
5466 context_switch (ecs
);
5468 current_inferior ()->waiting_for_vfork_done
= 0;
5469 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5471 if (handle_stop_requested (ecs
))
5474 /* This also takes care of reinserting breakpoints in the
5475 previously locked inferior. */
5479 case TARGET_WAITKIND_EXECD
:
5481 /* Note we can't read registers yet (the stop_pc), because we
5482 don't yet know the inferior's post-exec architecture.
5483 'stop_pc' is explicitly read below instead. */
5484 switch_to_thread_no_regs (ecs
->event_thread
);
5486 /* Do whatever is necessary to the parent branch of the vfork. */
5487 handle_vfork_child_exec_or_exit (1);
5489 /* This causes the eventpoints and symbol table to be reset.
5490 Must do this now, before trying to determine whether to
5492 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5494 /* In follow_exec we may have deleted the original thread and
5495 created a new one. Make sure that the event thread is the
5496 execd thread for that case (this is a nop otherwise). */
5497 ecs
->event_thread
= inferior_thread ();
5499 ecs
->event_thread
->suspend
.stop_pc
5500 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5502 ecs
->event_thread
->control
.stop_bpstat
5503 = bpstat_stop_status (get_current_regcache ()->aspace (),
5504 ecs
->event_thread
->suspend
.stop_pc
,
5505 ecs
->event_thread
, &ecs
->ws
);
5507 /* Note that this may be referenced from inside
5508 bpstat_stop_status above, through inferior_has_execd. */
5509 xfree (ecs
->ws
.value
.execd_pathname
);
5510 ecs
->ws
.value
.execd_pathname
= NULL
;
5512 if (handle_stop_requested (ecs
))
5515 /* If no catchpoint triggered for this, then keep going. */
5516 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5518 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5522 process_event_stop_test (ecs
);
5525 /* Be careful not to try to gather much state about a thread
5526 that's in a syscall. It's frequently a losing proposition. */
5527 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5528 /* Getting the current syscall number. */
5529 if (handle_syscall_event (ecs
) == 0)
5530 process_event_stop_test (ecs
);
5533 /* Before examining the threads further, step this thread to
5534 get it entirely out of the syscall. (We get notice of the
5535 event when the thread is just on the verge of exiting a
5536 syscall. Stepping one instruction seems to get it back
5538 case TARGET_WAITKIND_SYSCALL_RETURN
:
5539 if (handle_syscall_event (ecs
) == 0)
5540 process_event_stop_test (ecs
);
5543 case TARGET_WAITKIND_STOPPED
:
5544 handle_signal_stop (ecs
);
5547 case TARGET_WAITKIND_NO_HISTORY
:
5548 /* Reverse execution: target ran out of history info. */
5550 /* Switch to the stopped thread. */
5551 context_switch (ecs
);
5552 infrun_debug_printf ("stopped");
5554 delete_just_stopped_threads_single_step_breakpoints ();
5555 ecs
->event_thread
->suspend
.stop_pc
5556 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5558 if (handle_stop_requested (ecs
))
5561 gdb::observers::no_history
.notify ();
5567 /* Restart threads back to what they were trying to do back when we
5568 paused them for an in-line step-over. The EVENT_THREAD thread is
5572 restart_threads (struct thread_info
*event_thread
)
5574 /* In case the instruction just stepped spawned a new thread. */
5575 update_thread_list ();
5577 for (thread_info
*tp
: all_non_exited_threads ())
5579 switch_to_thread_no_regs (tp
);
5581 if (tp
== event_thread
)
5583 infrun_debug_printf ("restart threads: [%s] is event thread",
5584 target_pid_to_str (tp
->ptid
).c_str ());
5588 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5590 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5591 target_pid_to_str (tp
->ptid
).c_str ());
5597 infrun_debug_printf ("restart threads: [%s] resumed",
5598 target_pid_to_str (tp
->ptid
).c_str ());
5599 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5603 if (thread_is_in_step_over_chain (tp
))
5605 infrun_debug_printf ("restart threads: [%s] needs step-over",
5606 target_pid_to_str (tp
->ptid
).c_str ());
5607 gdb_assert (!tp
->resumed
);
5612 if (tp
->suspend
.waitstatus_pending_p
)
5614 infrun_debug_printf ("restart threads: [%s] has pending status",
5615 target_pid_to_str (tp
->ptid
).c_str ());
5620 gdb_assert (!tp
->stop_requested
);
5622 /* If some thread needs to start a step-over at this point, it
5623 should still be in the step-over queue, and thus skipped
5625 if (thread_still_needs_step_over (tp
))
5627 internal_error (__FILE__
, __LINE__
,
5628 "thread [%s] needs a step-over, but not in "
5629 "step-over queue\n",
5630 target_pid_to_str (tp
->ptid
).c_str ());
5633 if (currently_stepping (tp
))
5635 infrun_debug_printf ("restart threads: [%s] was stepping",
5636 target_pid_to_str (tp
->ptid
).c_str ());
5637 keep_going_stepped_thread (tp
);
5641 struct execution_control_state ecss
;
5642 struct execution_control_state
*ecs
= &ecss
;
5644 infrun_debug_printf ("restart threads: [%s] continuing",
5645 target_pid_to_str (tp
->ptid
).c_str ());
5646 reset_ecs (ecs
, tp
);
5647 switch_to_thread (tp
);
5648 keep_going_pass_signal (ecs
);
5653 /* Callback for iterate_over_threads. Find a resumed thread that has
5654 a pending waitstatus. */
5657 resumed_thread_with_pending_status (struct thread_info
*tp
,
5661 && tp
->suspend
.waitstatus_pending_p
);
5664 /* Called when we get an event that may finish an in-line or
5665 out-of-line (displaced stepping) step-over started previously.
5666 Return true if the event is processed and we should go back to the
5667 event loop; false if the caller should continue processing the
5671 finish_step_over (struct execution_control_state
*ecs
)
5673 int had_step_over_info
;
5675 displaced_step_fixup (ecs
->event_thread
,
5676 ecs
->event_thread
->suspend
.stop_signal
);
5678 had_step_over_info
= step_over_info_valid_p ();
5680 if (had_step_over_info
)
5682 /* If we're stepping over a breakpoint with all threads locked,
5683 then only the thread that was stepped should be reporting
5685 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5687 clear_step_over_info ();
5690 if (!target_is_non_stop_p ())
5693 /* Start a new step-over in another thread if there's one that
5697 /* If we were stepping over a breakpoint before, and haven't started
5698 a new in-line step-over sequence, then restart all other threads
5699 (except the event thread). We can't do this in all-stop, as then
5700 e.g., we wouldn't be able to issue any other remote packet until
5701 these other threads stop. */
5702 if (had_step_over_info
&& !step_over_info_valid_p ())
5704 struct thread_info
*pending
;
5706 /* If we only have threads with pending statuses, the restart
5707 below won't restart any thread and so nothing re-inserts the
5708 breakpoint we just stepped over. But we need it inserted
5709 when we later process the pending events, otherwise if
5710 another thread has a pending event for this breakpoint too,
5711 we'd discard its event (because the breakpoint that
5712 originally caused the event was no longer inserted). */
5713 context_switch (ecs
);
5714 insert_breakpoints ();
5716 restart_threads (ecs
->event_thread
);
5718 /* If we have events pending, go through handle_inferior_event
5719 again, picking up a pending event at random. This avoids
5720 thread starvation. */
5722 /* But not if we just stepped over a watchpoint in order to let
5723 the instruction execute so we can evaluate its expression.
5724 The set of watchpoints that triggered is recorded in the
5725 breakpoint objects themselves (see bp->watchpoint_triggered).
5726 If we processed another event first, that other event could
5727 clobber this info. */
5728 if (ecs
->event_thread
->stepping_over_watchpoint
)
5731 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5733 if (pending
!= NULL
)
5735 struct thread_info
*tp
= ecs
->event_thread
;
5736 struct regcache
*regcache
;
5738 infrun_debug_printf ("found resumed threads with "
5739 "pending events, saving status");
5741 gdb_assert (pending
!= tp
);
5743 /* Record the event thread's event for later. */
5744 save_waitstatus (tp
, &ecs
->ws
);
5745 /* This was cleared early, by handle_inferior_event. Set it
5746 so this pending event is considered by
5750 gdb_assert (!tp
->executing
);
5752 regcache
= get_thread_regcache (tp
);
5753 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5755 infrun_debug_printf ("saved stop_pc=%s for %s "
5756 "(currently_stepping=%d)",
5757 paddress (target_gdbarch (),
5758 tp
->suspend
.stop_pc
),
5759 target_pid_to_str (tp
->ptid
).c_str (),
5760 currently_stepping (tp
));
5762 /* This in-line step-over finished; clear this so we won't
5763 start a new one. This is what handle_signal_stop would
5764 do, if we returned false. */
5765 tp
->stepping_over_breakpoint
= 0;
5767 /* Wake up the event loop again. */
5768 mark_async_event_handler (infrun_async_inferior_event_token
);
5770 prepare_to_wait (ecs
);
5778 /* Come here when the program has stopped with a signal. */
5781 handle_signal_stop (struct execution_control_state
*ecs
)
5783 struct frame_info
*frame
;
5784 struct gdbarch
*gdbarch
;
5785 int stopped_by_watchpoint
;
5786 enum stop_kind stop_soon
;
5789 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5791 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5793 /* Do we need to clean up the state of a thread that has
5794 completed a displaced single-step? (Doing so usually affects
5795 the PC, so do it here, before we set stop_pc.) */
5796 if (finish_step_over (ecs
))
5799 /* If we either finished a single-step or hit a breakpoint, but
5800 the user wanted this thread to be stopped, pretend we got a
5801 SIG0 (generic unsignaled stop). */
5802 if (ecs
->event_thread
->stop_requested
5803 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5804 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5806 ecs
->event_thread
->suspend
.stop_pc
5807 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5811 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5812 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5814 switch_to_thread (ecs
->event_thread
);
5816 infrun_debug_printf ("stop_pc=%s",
5817 paddress (reg_gdbarch
,
5818 ecs
->event_thread
->suspend
.stop_pc
));
5819 if (target_stopped_by_watchpoint ())
5823 infrun_debug_printf ("stopped by watchpoint");
5825 if (target_stopped_data_address (current_top_target (), &addr
))
5826 infrun_debug_printf ("stopped data address=%s",
5827 paddress (reg_gdbarch
, addr
));
5829 infrun_debug_printf ("(no data address available)");
5833 /* This is originated from start_remote(), start_inferior() and
5834 shared libraries hook functions. */
5835 stop_soon
= get_inferior_stop_soon (ecs
);
5836 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5838 context_switch (ecs
);
5839 infrun_debug_printf ("quietly stopped");
5840 stop_print_frame
= 1;
5845 /* This originates from attach_command(). We need to overwrite
5846 the stop_signal here, because some kernels don't ignore a
5847 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5848 See more comments in inferior.h. On the other hand, if we
5849 get a non-SIGSTOP, report it to the user - assume the backend
5850 will handle the SIGSTOP if it should show up later.
5852 Also consider that the attach is complete when we see a
5853 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5854 target extended-remote report it instead of a SIGSTOP
5855 (e.g. gdbserver). We already rely on SIGTRAP being our
5856 signal, so this is no exception.
5858 Also consider that the attach is complete when we see a
5859 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5860 the target to stop all threads of the inferior, in case the
5861 low level attach operation doesn't stop them implicitly. If
5862 they weren't stopped implicitly, then the stub will report a
5863 GDB_SIGNAL_0, meaning: stopped for no particular reason
5864 other than GDB's request. */
5865 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5866 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5867 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5868 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5870 stop_print_frame
= 1;
5872 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5876 /* See if something interesting happened to the non-current thread. If
5877 so, then switch to that thread. */
5878 if (ecs
->ptid
!= inferior_ptid
)
5880 infrun_debug_printf ("context switch");
5882 context_switch (ecs
);
5884 if (deprecated_context_hook
)
5885 deprecated_context_hook (ecs
->event_thread
->global_num
);
5888 /* At this point, get hold of the now-current thread's frame. */
5889 frame
= get_current_frame ();
5890 gdbarch
= get_frame_arch (frame
);
5892 /* Pull the single step breakpoints out of the target. */
5893 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5895 struct regcache
*regcache
;
5898 regcache
= get_thread_regcache (ecs
->event_thread
);
5899 const address_space
*aspace
= regcache
->aspace ();
5901 pc
= regcache_read_pc (regcache
);
5903 /* However, before doing so, if this single-step breakpoint was
5904 actually for another thread, set this thread up for moving
5906 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5909 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5911 infrun_debug_printf ("[%s] hit another thread's single-step "
5913 target_pid_to_str (ecs
->ptid
).c_str ());
5914 ecs
->hit_singlestep_breakpoint
= 1;
5919 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5920 target_pid_to_str (ecs
->ptid
).c_str ());
5923 delete_just_stopped_threads_single_step_breakpoints ();
5925 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5926 && ecs
->event_thread
->control
.trap_expected
5927 && ecs
->event_thread
->stepping_over_watchpoint
)
5928 stopped_by_watchpoint
= 0;
5930 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5932 /* If necessary, step over this watchpoint. We'll be back to display
5934 if (stopped_by_watchpoint
5935 && (target_have_steppable_watchpoint
5936 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5938 /* At this point, we are stopped at an instruction which has
5939 attempted to write to a piece of memory under control of
5940 a watchpoint. The instruction hasn't actually executed
5941 yet. If we were to evaluate the watchpoint expression
5942 now, we would get the old value, and therefore no change
5943 would seem to have occurred.
5945 In order to make watchpoints work `right', we really need
5946 to complete the memory write, and then evaluate the
5947 watchpoint expression. We do this by single-stepping the
5950 It may not be necessary to disable the watchpoint to step over
5951 it. For example, the PA can (with some kernel cooperation)
5952 single step over a watchpoint without disabling the watchpoint.
5954 It is far more common to need to disable a watchpoint to step
5955 the inferior over it. If we have non-steppable watchpoints,
5956 we must disable the current watchpoint; it's simplest to
5957 disable all watchpoints.
5959 Any breakpoint at PC must also be stepped over -- if there's
5960 one, it will have already triggered before the watchpoint
5961 triggered, and we either already reported it to the user, or
5962 it didn't cause a stop and we called keep_going. In either
5963 case, if there was a breakpoint at PC, we must be trying to
5965 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5970 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5971 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5972 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5973 ecs
->event_thread
->control
.stop_step
= 0;
5974 stop_print_frame
= 1;
5975 stopped_by_random_signal
= 0;
5976 bpstat stop_chain
= NULL
;
5978 /* Hide inlined functions starting here, unless we just performed stepi or
5979 nexti. After stepi and nexti, always show the innermost frame (not any
5980 inline function call sites). */
5981 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5983 const address_space
*aspace
5984 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5986 /* skip_inline_frames is expensive, so we avoid it if we can
5987 determine that the address is one where functions cannot have
5988 been inlined. This improves performance with inferiors that
5989 load a lot of shared libraries, because the solib event
5990 breakpoint is defined as the address of a function (i.e. not
5991 inline). Note that we have to check the previous PC as well
5992 as the current one to catch cases when we have just
5993 single-stepped off a breakpoint prior to reinstating it.
5994 Note that we're assuming that the code we single-step to is
5995 not inline, but that's not definitive: there's nothing
5996 preventing the event breakpoint function from containing
5997 inlined code, and the single-step ending up there. If the
5998 user had set a breakpoint on that inlined code, the missing
5999 skip_inline_frames call would break things. Fortunately
6000 that's an extremely unlikely scenario. */
6001 if (!pc_at_non_inline_function (aspace
,
6002 ecs
->event_thread
->suspend
.stop_pc
,
6004 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6005 && ecs
->event_thread
->control
.trap_expected
6006 && pc_at_non_inline_function (aspace
,
6007 ecs
->event_thread
->prev_pc
,
6010 stop_chain
= build_bpstat_chain (aspace
,
6011 ecs
->event_thread
->suspend
.stop_pc
,
6013 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6015 /* Re-fetch current thread's frame in case that invalidated
6017 frame
= get_current_frame ();
6018 gdbarch
= get_frame_arch (frame
);
6022 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6023 && ecs
->event_thread
->control
.trap_expected
6024 && gdbarch_single_step_through_delay_p (gdbarch
)
6025 && currently_stepping (ecs
->event_thread
))
6027 /* We're trying to step off a breakpoint. Turns out that we're
6028 also on an instruction that needs to be stepped multiple
6029 times before it's been fully executing. E.g., architectures
6030 with a delay slot. It needs to be stepped twice, once for
6031 the instruction and once for the delay slot. */
6032 int step_through_delay
6033 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6035 if (step_through_delay
)
6036 infrun_debug_printf ("step through delay");
6038 if (ecs
->event_thread
->control
.step_range_end
== 0
6039 && step_through_delay
)
6041 /* The user issued a continue when stopped at a breakpoint.
6042 Set up for another trap and get out of here. */
6043 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6047 else if (step_through_delay
)
6049 /* The user issued a step when stopped at a breakpoint.
6050 Maybe we should stop, maybe we should not - the delay
6051 slot *might* correspond to a line of source. In any
6052 case, don't decide that here, just set
6053 ecs->stepping_over_breakpoint, making sure we
6054 single-step again before breakpoints are re-inserted. */
6055 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6059 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6060 handles this event. */
6061 ecs
->event_thread
->control
.stop_bpstat
6062 = bpstat_stop_status (get_current_regcache ()->aspace (),
6063 ecs
->event_thread
->suspend
.stop_pc
,
6064 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6066 /* Following in case break condition called a
6068 stop_print_frame
= 1;
6070 /* This is where we handle "moribund" watchpoints. Unlike
6071 software breakpoints traps, hardware watchpoint traps are
6072 always distinguishable from random traps. If no high-level
6073 watchpoint is associated with the reported stop data address
6074 anymore, then the bpstat does not explain the signal ---
6075 simply make sure to ignore it if `stopped_by_watchpoint' is
6078 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6079 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6081 && stopped_by_watchpoint
)
6083 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6087 /* NOTE: cagney/2003-03-29: These checks for a random signal
6088 at one stage in the past included checks for an inferior
6089 function call's call dummy's return breakpoint. The original
6090 comment, that went with the test, read:
6092 ``End of a stack dummy. Some systems (e.g. Sony news) give
6093 another signal besides SIGTRAP, so check here as well as
6096 If someone ever tries to get call dummys on a
6097 non-executable stack to work (where the target would stop
6098 with something like a SIGSEGV), then those tests might need
6099 to be re-instated. Given, however, that the tests were only
6100 enabled when momentary breakpoints were not being used, I
6101 suspect that it won't be the case.
6103 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6104 be necessary for call dummies on a non-executable stack on
6107 /* See if the breakpoints module can explain the signal. */
6109 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6110 ecs
->event_thread
->suspend
.stop_signal
);
6112 /* Maybe this was a trap for a software breakpoint that has since
6114 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6116 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6117 ecs
->event_thread
->suspend
.stop_pc
))
6119 struct regcache
*regcache
;
6122 /* Re-adjust PC to what the program would see if GDB was not
6124 regcache
= get_thread_regcache (ecs
->event_thread
);
6125 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6128 gdb::optional
<scoped_restore_tmpl
<int>>
6129 restore_operation_disable
;
6131 if (record_full_is_used ())
6132 restore_operation_disable
.emplace
6133 (record_full_gdb_operation_disable_set ());
6135 regcache_write_pc (regcache
,
6136 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6141 /* A delayed software breakpoint event. Ignore the trap. */
6142 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6147 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6148 has since been removed. */
6149 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6151 /* A delayed hardware breakpoint event. Ignore the trap. */
6152 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6157 /* If not, perhaps stepping/nexting can. */
6159 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6160 && currently_stepping (ecs
->event_thread
));
6162 /* Perhaps the thread hit a single-step breakpoint of _another_
6163 thread. Single-step breakpoints are transparent to the
6164 breakpoints module. */
6166 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6168 /* No? Perhaps we got a moribund watchpoint. */
6170 random_signal
= !stopped_by_watchpoint
;
6172 /* Always stop if the user explicitly requested this thread to
6174 if (ecs
->event_thread
->stop_requested
)
6177 infrun_debug_printf ("user-requested stop");
6180 /* For the program's own signals, act according to
6181 the signal handling tables. */
6185 /* Signal not for debugging purposes. */
6186 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6187 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6189 infrun_debug_printf ("random signal (%s)",
6190 gdb_signal_to_symbol_string (stop_signal
));
6192 stopped_by_random_signal
= 1;
6194 /* Always stop on signals if we're either just gaining control
6195 of the program, or the user explicitly requested this thread
6196 to remain stopped. */
6197 if (stop_soon
!= NO_STOP_QUIETLY
6198 || ecs
->event_thread
->stop_requested
6200 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6206 /* Notify observers the signal has "handle print" set. Note we
6207 returned early above if stopping; normal_stop handles the
6208 printing in that case. */
6209 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6211 /* The signal table tells us to print about this signal. */
6212 target_terminal::ours_for_output ();
6213 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6214 target_terminal::inferior ();
6217 /* Clear the signal if it should not be passed. */
6218 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6219 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6221 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6222 && ecs
->event_thread
->control
.trap_expected
6223 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6225 /* We were just starting a new sequence, attempting to
6226 single-step off of a breakpoint and expecting a SIGTRAP.
6227 Instead this signal arrives. This signal will take us out
6228 of the stepping range so GDB needs to remember to, when
6229 the signal handler returns, resume stepping off that
6231 /* To simplify things, "continue" is forced to use the same
6232 code paths as single-step - set a breakpoint at the
6233 signal return address and then, once hit, step off that
6235 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6237 insert_hp_step_resume_breakpoint_at_frame (frame
);
6238 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6239 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6240 ecs
->event_thread
->control
.trap_expected
= 0;
6242 /* If we were nexting/stepping some other thread, switch to
6243 it, so that we don't continue it, losing control. */
6244 if (!switch_back_to_stepped_thread (ecs
))
6249 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6250 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6252 || ecs
->event_thread
->control
.step_range_end
== 1)
6253 && frame_id_eq (get_stack_frame_id (frame
),
6254 ecs
->event_thread
->control
.step_stack_frame_id
)
6255 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6257 /* The inferior is about to take a signal that will take it
6258 out of the single step range. Set a breakpoint at the
6259 current PC (which is presumably where the signal handler
6260 will eventually return) and then allow the inferior to
6263 Note that this is only needed for a signal delivered
6264 while in the single-step range. Nested signals aren't a
6265 problem as they eventually all return. */
6266 infrun_debug_printf ("signal may take us out of single-step range");
6268 clear_step_over_info ();
6269 insert_hp_step_resume_breakpoint_at_frame (frame
);
6270 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6271 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6272 ecs
->event_thread
->control
.trap_expected
= 0;
6277 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6278 when either there's a nested signal, or when there's a
6279 pending signal enabled just as the signal handler returns
6280 (leaving the inferior at the step-resume-breakpoint without
6281 actually executing it). Either way continue until the
6282 breakpoint is really hit. */
6284 if (!switch_back_to_stepped_thread (ecs
))
6286 infrun_debug_printf ("random signal, keep going");
6293 process_event_stop_test (ecs
);
6296 /* Come here when we've got some debug event / signal we can explain
6297 (IOW, not a random signal), and test whether it should cause a
6298 stop, or whether we should resume the inferior (transparently).
6299 E.g., could be a breakpoint whose condition evaluates false; we
6300 could be still stepping within the line; etc. */
6303 process_event_stop_test (struct execution_control_state
*ecs
)
6305 struct symtab_and_line stop_pc_sal
;
6306 struct frame_info
*frame
;
6307 struct gdbarch
*gdbarch
;
6308 CORE_ADDR jmp_buf_pc
;
6309 struct bpstat_what what
;
6311 /* Handle cases caused by hitting a breakpoint. */
6313 frame
= get_current_frame ();
6314 gdbarch
= get_frame_arch (frame
);
6316 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6318 if (what
.call_dummy
)
6320 stop_stack_dummy
= what
.call_dummy
;
6323 /* A few breakpoint types have callbacks associated (e.g.,
6324 bp_jit_event). Run them now. */
6325 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6327 /* If we hit an internal event that triggers symbol changes, the
6328 current frame will be invalidated within bpstat_what (e.g., if we
6329 hit an internal solib event). Re-fetch it. */
6330 frame
= get_current_frame ();
6331 gdbarch
= get_frame_arch (frame
);
6333 switch (what
.main_action
)
6335 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6336 /* If we hit the breakpoint at longjmp while stepping, we
6337 install a momentary breakpoint at the target of the
6340 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6342 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6344 if (what
.is_longjmp
)
6346 struct value
*arg_value
;
6348 /* If we set the longjmp breakpoint via a SystemTap probe,
6349 then use it to extract the arguments. The destination PC
6350 is the third argument to the probe. */
6351 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6354 jmp_buf_pc
= value_as_address (arg_value
);
6355 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6357 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6358 || !gdbarch_get_longjmp_target (gdbarch
,
6359 frame
, &jmp_buf_pc
))
6361 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6362 "(!gdbarch_get_longjmp_target)");
6367 /* Insert a breakpoint at resume address. */
6368 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6371 check_exception_resume (ecs
, frame
);
6375 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6377 struct frame_info
*init_frame
;
6379 /* There are several cases to consider.
6381 1. The initiating frame no longer exists. In this case we
6382 must stop, because the exception or longjmp has gone too
6385 2. The initiating frame exists, and is the same as the
6386 current frame. We stop, because the exception or longjmp
6389 3. The initiating frame exists and is different from the
6390 current frame. This means the exception or longjmp has
6391 been caught beneath the initiating frame, so keep going.
6393 4. longjmp breakpoint has been placed just to protect
6394 against stale dummy frames and user is not interested in
6395 stopping around longjmps. */
6397 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6399 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6401 delete_exception_resume_breakpoint (ecs
->event_thread
);
6403 if (what
.is_longjmp
)
6405 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6407 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6415 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6419 struct frame_id current_id
6420 = get_frame_id (get_current_frame ());
6421 if (frame_id_eq (current_id
,
6422 ecs
->event_thread
->initiating_frame
))
6424 /* Case 2. Fall through. */
6434 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6436 delete_step_resume_breakpoint (ecs
->event_thread
);
6438 end_stepping_range (ecs
);
6442 case BPSTAT_WHAT_SINGLE
:
6443 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6444 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6445 /* Still need to check other stuff, at least the case where we
6446 are stepping and step out of the right range. */
6449 case BPSTAT_WHAT_STEP_RESUME
:
6450 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6452 delete_step_resume_breakpoint (ecs
->event_thread
);
6453 if (ecs
->event_thread
->control
.proceed_to_finish
6454 && execution_direction
== EXEC_REVERSE
)
6456 struct thread_info
*tp
= ecs
->event_thread
;
6458 /* We are finishing a function in reverse, and just hit the
6459 step-resume breakpoint at the start address of the
6460 function, and we're almost there -- just need to back up
6461 by one more single-step, which should take us back to the
6463 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6467 fill_in_stop_func (gdbarch
, ecs
);
6468 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6469 && execution_direction
== EXEC_REVERSE
)
6471 /* We are stepping over a function call in reverse, and just
6472 hit the step-resume breakpoint at the start address of
6473 the function. Go back to single-stepping, which should
6474 take us back to the function call. */
6475 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6481 case BPSTAT_WHAT_STOP_NOISY
:
6482 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6483 stop_print_frame
= 1;
6485 /* Assume the thread stopped for a breakpoint. We'll still check
6486 whether a/the breakpoint is there when the thread is next
6488 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6493 case BPSTAT_WHAT_STOP_SILENT
:
6494 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6495 stop_print_frame
= 0;
6497 /* Assume the thread stopped for a breakpoint. We'll still check
6498 whether a/the breakpoint is there when the thread is next
6500 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6504 case BPSTAT_WHAT_HP_STEP_RESUME
:
6505 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6507 delete_step_resume_breakpoint (ecs
->event_thread
);
6508 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6510 /* Back when the step-resume breakpoint was inserted, we
6511 were trying to single-step off a breakpoint. Go back to
6513 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6514 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6520 case BPSTAT_WHAT_KEEP_CHECKING
:
6524 /* If we stepped a permanent breakpoint and we had a high priority
6525 step-resume breakpoint for the address we stepped, but we didn't
6526 hit it, then we must have stepped into the signal handler. The
6527 step-resume was only necessary to catch the case of _not_
6528 stepping into the handler, so delete it, and fall through to
6529 checking whether the step finished. */
6530 if (ecs
->event_thread
->stepped_breakpoint
)
6532 struct breakpoint
*sr_bp
6533 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6536 && sr_bp
->loc
->permanent
6537 && sr_bp
->type
== bp_hp_step_resume
6538 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6540 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6541 delete_step_resume_breakpoint (ecs
->event_thread
);
6542 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6546 /* We come here if we hit a breakpoint but should not stop for it.
6547 Possibly we also were stepping and should stop for that. So fall
6548 through and test for stepping. But, if not stepping, do not
6551 /* In all-stop mode, if we're currently stepping but have stopped in
6552 some other thread, we need to switch back to the stepped thread. */
6553 if (switch_back_to_stepped_thread (ecs
))
6556 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6558 infrun_debug_printf ("step-resume breakpoint is inserted");
6560 /* Having a step-resume breakpoint overrides anything
6561 else having to do with stepping commands until
6562 that breakpoint is reached. */
6567 if (ecs
->event_thread
->control
.step_range_end
== 0)
6569 infrun_debug_printf ("no stepping, continue");
6570 /* Likewise if we aren't even stepping. */
6575 /* Re-fetch current thread's frame in case the code above caused
6576 the frame cache to be re-initialized, making our FRAME variable
6577 a dangling pointer. */
6578 frame
= get_current_frame ();
6579 gdbarch
= get_frame_arch (frame
);
6580 fill_in_stop_func (gdbarch
, ecs
);
6582 /* If stepping through a line, keep going if still within it.
6584 Note that step_range_end is the address of the first instruction
6585 beyond the step range, and NOT the address of the last instruction
6588 Note also that during reverse execution, we may be stepping
6589 through a function epilogue and therefore must detect when
6590 the current-frame changes in the middle of a line. */
6592 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6594 && (execution_direction
!= EXEC_REVERSE
6595 || frame_id_eq (get_frame_id (frame
),
6596 ecs
->event_thread
->control
.step_frame_id
)))
6599 ("stepping inside range [%s-%s]",
6600 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6601 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6603 /* Tentatively re-enable range stepping; `resume' disables it if
6604 necessary (e.g., if we're stepping over a breakpoint or we
6605 have software watchpoints). */
6606 ecs
->event_thread
->control
.may_range_step
= 1;
6608 /* When stepping backward, stop at beginning of line range
6609 (unless it's the function entry point, in which case
6610 keep going back to the call point). */
6611 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6612 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6613 && stop_pc
!= ecs
->stop_func_start
6614 && execution_direction
== EXEC_REVERSE
)
6615 end_stepping_range (ecs
);
6622 /* We stepped out of the stepping range. */
6624 /* If we are stepping at the source level and entered the runtime
6625 loader dynamic symbol resolution code...
6627 EXEC_FORWARD: we keep on single stepping until we exit the run
6628 time loader code and reach the callee's address.
6630 EXEC_REVERSE: we've already executed the callee (backward), and
6631 the runtime loader code is handled just like any other
6632 undebuggable function call. Now we need only keep stepping
6633 backward through the trampoline code, and that's handled further
6634 down, so there is nothing for us to do here. */
6636 if (execution_direction
!= EXEC_REVERSE
6637 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6638 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6640 CORE_ADDR pc_after_resolver
=
6641 gdbarch_skip_solib_resolver (gdbarch
,
6642 ecs
->event_thread
->suspend
.stop_pc
);
6644 infrun_debug_printf ("stepped into dynsym resolve code");
6646 if (pc_after_resolver
)
6648 /* Set up a step-resume breakpoint at the address
6649 indicated by SKIP_SOLIB_RESOLVER. */
6650 symtab_and_line sr_sal
;
6651 sr_sal
.pc
= pc_after_resolver
;
6652 sr_sal
.pspace
= get_frame_program_space (frame
);
6654 insert_step_resume_breakpoint_at_sal (gdbarch
,
6655 sr_sal
, null_frame_id
);
6662 /* Step through an indirect branch thunk. */
6663 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6664 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6665 ecs
->event_thread
->suspend
.stop_pc
))
6667 infrun_debug_printf ("stepped into indirect branch thunk");
6672 if (ecs
->event_thread
->control
.step_range_end
!= 1
6673 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6674 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6675 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6677 infrun_debug_printf ("stepped into signal trampoline");
6678 /* The inferior, while doing a "step" or "next", has ended up in
6679 a signal trampoline (either by a signal being delivered or by
6680 the signal handler returning). Just single-step until the
6681 inferior leaves the trampoline (either by calling the handler
6687 /* If we're in the return path from a shared library trampoline,
6688 we want to proceed through the trampoline when stepping. */
6689 /* macro/2012-04-25: This needs to come before the subroutine
6690 call check below as on some targets return trampolines look
6691 like subroutine calls (MIPS16 return thunks). */
6692 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6693 ecs
->event_thread
->suspend
.stop_pc
,
6694 ecs
->stop_func_name
)
6695 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6697 /* Determine where this trampoline returns. */
6698 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6699 CORE_ADDR real_stop_pc
6700 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6702 infrun_debug_printf ("stepped into solib return tramp");
6704 /* Only proceed through if we know where it's going. */
6707 /* And put the step-breakpoint there and go until there. */
6708 symtab_and_line sr_sal
;
6709 sr_sal
.pc
= real_stop_pc
;
6710 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6711 sr_sal
.pspace
= get_frame_program_space (frame
);
6713 /* Do not specify what the fp should be when we stop since
6714 on some machines the prologue is where the new fp value
6716 insert_step_resume_breakpoint_at_sal (gdbarch
,
6717 sr_sal
, null_frame_id
);
6719 /* Restart without fiddling with the step ranges or
6726 /* Check for subroutine calls. The check for the current frame
6727 equalling the step ID is not necessary - the check of the
6728 previous frame's ID is sufficient - but it is a common case and
6729 cheaper than checking the previous frame's ID.
6731 NOTE: frame_id_eq will never report two invalid frame IDs as
6732 being equal, so to get into this block, both the current and
6733 previous frame must have valid frame IDs. */
6734 /* The outer_frame_id check is a heuristic to detect stepping
6735 through startup code. If we step over an instruction which
6736 sets the stack pointer from an invalid value to a valid value,
6737 we may detect that as a subroutine call from the mythical
6738 "outermost" function. This could be fixed by marking
6739 outermost frames as !stack_p,code_p,special_p. Then the
6740 initial outermost frame, before sp was valid, would
6741 have code_addr == &_start. See the comment in frame_id_eq
6743 if (!frame_id_eq (get_stack_frame_id (frame
),
6744 ecs
->event_thread
->control
.step_stack_frame_id
)
6745 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6746 ecs
->event_thread
->control
.step_stack_frame_id
)
6747 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6749 || (ecs
->event_thread
->control
.step_start_function
6750 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6752 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6753 CORE_ADDR real_stop_pc
;
6755 infrun_debug_printf ("stepped into subroutine");
6757 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6759 /* I presume that step_over_calls is only 0 when we're
6760 supposed to be stepping at the assembly language level
6761 ("stepi"). Just stop. */
6762 /* And this works the same backward as frontward. MVS */
6763 end_stepping_range (ecs
);
6767 /* Reverse stepping through solib trampolines. */
6769 if (execution_direction
== EXEC_REVERSE
6770 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6771 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6772 || (ecs
->stop_func_start
== 0
6773 && in_solib_dynsym_resolve_code (stop_pc
))))
6775 /* Any solib trampoline code can be handled in reverse
6776 by simply continuing to single-step. We have already
6777 executed the solib function (backwards), and a few
6778 steps will take us back through the trampoline to the
6784 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6786 /* We're doing a "next".
6788 Normal (forward) execution: set a breakpoint at the
6789 callee's return address (the address at which the caller
6792 Reverse (backward) execution. set the step-resume
6793 breakpoint at the start of the function that we just
6794 stepped into (backwards), and continue to there. When we
6795 get there, we'll need to single-step back to the caller. */
6797 if (execution_direction
== EXEC_REVERSE
)
6799 /* If we're already at the start of the function, we've either
6800 just stepped backward into a single instruction function,
6801 or stepped back out of a signal handler to the first instruction
6802 of the function. Just keep going, which will single-step back
6804 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6806 /* Normal function call return (static or dynamic). */
6807 symtab_and_line sr_sal
;
6808 sr_sal
.pc
= ecs
->stop_func_start
;
6809 sr_sal
.pspace
= get_frame_program_space (frame
);
6810 insert_step_resume_breakpoint_at_sal (gdbarch
,
6811 sr_sal
, null_frame_id
);
6815 insert_step_resume_breakpoint_at_caller (frame
);
6821 /* If we are in a function call trampoline (a stub between the
6822 calling routine and the real function), locate the real
6823 function. That's what tells us (a) whether we want to step
6824 into it at all, and (b) what prologue we want to run to the
6825 end of, if we do step into it. */
6826 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6827 if (real_stop_pc
== 0)
6828 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6829 if (real_stop_pc
!= 0)
6830 ecs
->stop_func_start
= real_stop_pc
;
6832 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6834 symtab_and_line sr_sal
;
6835 sr_sal
.pc
= ecs
->stop_func_start
;
6836 sr_sal
.pspace
= get_frame_program_space (frame
);
6838 insert_step_resume_breakpoint_at_sal (gdbarch
,
6839 sr_sal
, null_frame_id
);
6844 /* If we have line number information for the function we are
6845 thinking of stepping into and the function isn't on the skip
6848 If there are several symtabs at that PC (e.g. with include
6849 files), just want to know whether *any* of them have line
6850 numbers. find_pc_line handles this. */
6852 struct symtab_and_line tmp_sal
;
6854 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6855 if (tmp_sal
.line
!= 0
6856 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6858 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6860 if (execution_direction
== EXEC_REVERSE
)
6861 handle_step_into_function_backward (gdbarch
, ecs
);
6863 handle_step_into_function (gdbarch
, ecs
);
6868 /* If we have no line number and the step-stop-if-no-debug is
6869 set, we stop the step so that the user has a chance to switch
6870 in assembly mode. */
6871 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6872 && step_stop_if_no_debug
)
6874 end_stepping_range (ecs
);
6878 if (execution_direction
== EXEC_REVERSE
)
6880 /* If we're already at the start of the function, we've either just
6881 stepped backward into a single instruction function without line
6882 number info, or stepped back out of a signal handler to the first
6883 instruction of the function without line number info. Just keep
6884 going, which will single-step back to the caller. */
6885 if (ecs
->stop_func_start
!= stop_pc
)
6887 /* Set a breakpoint at callee's start address.
6888 From there we can step once and be back in the caller. */
6889 symtab_and_line sr_sal
;
6890 sr_sal
.pc
= ecs
->stop_func_start
;
6891 sr_sal
.pspace
= get_frame_program_space (frame
);
6892 insert_step_resume_breakpoint_at_sal (gdbarch
,
6893 sr_sal
, null_frame_id
);
6897 /* Set a breakpoint at callee's return address (the address
6898 at which the caller will resume). */
6899 insert_step_resume_breakpoint_at_caller (frame
);
6905 /* Reverse stepping through solib trampolines. */
6907 if (execution_direction
== EXEC_REVERSE
6908 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6910 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6912 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6913 || (ecs
->stop_func_start
== 0
6914 && in_solib_dynsym_resolve_code (stop_pc
)))
6916 /* Any solib trampoline code can be handled in reverse
6917 by simply continuing to single-step. We have already
6918 executed the solib function (backwards), and a few
6919 steps will take us back through the trampoline to the
6924 else if (in_solib_dynsym_resolve_code (stop_pc
))
6926 /* Stepped backward into the solib dynsym resolver.
6927 Set a breakpoint at its start and continue, then
6928 one more step will take us out. */
6929 symtab_and_line sr_sal
;
6930 sr_sal
.pc
= ecs
->stop_func_start
;
6931 sr_sal
.pspace
= get_frame_program_space (frame
);
6932 insert_step_resume_breakpoint_at_sal (gdbarch
,
6933 sr_sal
, null_frame_id
);
6939 /* This always returns the sal for the inner-most frame when we are in a
6940 stack of inlined frames, even if GDB actually believes that it is in a
6941 more outer frame. This is checked for below by calls to
6942 inline_skipped_frames. */
6943 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6945 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6946 the trampoline processing logic, however, there are some trampolines
6947 that have no names, so we should do trampoline handling first. */
6948 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6949 && ecs
->stop_func_name
== NULL
6950 && stop_pc_sal
.line
== 0)
6952 infrun_debug_printf ("stepped into undebuggable function");
6954 /* The inferior just stepped into, or returned to, an
6955 undebuggable function (where there is no debugging information
6956 and no line number corresponding to the address where the
6957 inferior stopped). Since we want to skip this kind of code,
6958 we keep going until the inferior returns from this
6959 function - unless the user has asked us not to (via
6960 set step-mode) or we no longer know how to get back
6961 to the call site. */
6962 if (step_stop_if_no_debug
6963 || !frame_id_p (frame_unwind_caller_id (frame
)))
6965 /* If we have no line number and the step-stop-if-no-debug
6966 is set, we stop the step so that the user has a chance to
6967 switch in assembly mode. */
6968 end_stepping_range (ecs
);
6973 /* Set a breakpoint at callee's return address (the address
6974 at which the caller will resume). */
6975 insert_step_resume_breakpoint_at_caller (frame
);
6981 if (ecs
->event_thread
->control
.step_range_end
== 1)
6983 /* It is stepi or nexti. We always want to stop stepping after
6985 infrun_debug_printf ("stepi/nexti");
6986 end_stepping_range (ecs
);
6990 if (stop_pc_sal
.line
== 0)
6992 /* We have no line number information. That means to stop
6993 stepping (does this always happen right after one instruction,
6994 when we do "s" in a function with no line numbers,
6995 or can this happen as a result of a return or longjmp?). */
6996 infrun_debug_printf ("line number info");
6997 end_stepping_range (ecs
);
7001 /* Look for "calls" to inlined functions, part one. If the inline
7002 frame machinery detected some skipped call sites, we have entered
7003 a new inline function. */
7005 if (frame_id_eq (get_frame_id (get_current_frame ()),
7006 ecs
->event_thread
->control
.step_frame_id
)
7007 && inline_skipped_frames (ecs
->event_thread
))
7009 infrun_debug_printf ("stepped into inlined function");
7011 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7013 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7015 /* For "step", we're going to stop. But if the call site
7016 for this inlined function is on the same source line as
7017 we were previously stepping, go down into the function
7018 first. Otherwise stop at the call site. */
7020 if (call_sal
.line
== ecs
->event_thread
->current_line
7021 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7023 step_into_inline_frame (ecs
->event_thread
);
7024 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7031 end_stepping_range (ecs
);
7036 /* For "next", we should stop at the call site if it is on a
7037 different source line. Otherwise continue through the
7038 inlined function. */
7039 if (call_sal
.line
== ecs
->event_thread
->current_line
7040 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7043 end_stepping_range (ecs
);
7048 /* Look for "calls" to inlined functions, part two. If we are still
7049 in the same real function we were stepping through, but we have
7050 to go further up to find the exact frame ID, we are stepping
7051 through a more inlined call beyond its call site. */
7053 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7054 && !frame_id_eq (get_frame_id (get_current_frame ()),
7055 ecs
->event_thread
->control
.step_frame_id
)
7056 && stepped_in_from (get_current_frame (),
7057 ecs
->event_thread
->control
.step_frame_id
))
7059 infrun_debug_printf ("stepping through inlined function");
7061 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7062 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7065 end_stepping_range (ecs
);
7069 bool refresh_step_info
= true;
7070 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7071 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7072 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7074 if (stop_pc_sal
.is_stmt
)
7076 /* We are at the start of a different line. So stop. Note that
7077 we don't stop if we step into the middle of a different line.
7078 That is said to make things like for (;;) statements work
7080 infrun_debug_printf ("stepped to a different line");
7081 end_stepping_range (ecs
);
7084 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7085 ecs
->event_thread
->control
.step_frame_id
))
7087 /* We are at the start of a different line, however, this line is
7088 not marked as a statement, and we have not changed frame. We
7089 ignore this line table entry, and continue stepping forward,
7090 looking for a better place to stop. */
7091 refresh_step_info
= false;
7092 infrun_debug_printf ("stepped to a different line, but "
7093 "it's not the start of a statement");
7097 /* We aren't done stepping.
7099 Optimize by setting the stepping range to the line.
7100 (We might not be in the original line, but if we entered a
7101 new line in mid-statement, we continue stepping. This makes
7102 things like for(;;) statements work better.)
7104 If we entered a SAL that indicates a non-statement line table entry,
7105 then we update the stepping range, but we don't update the step info,
7106 which includes things like the line number we are stepping away from.
7107 This means we will stop when we find a line table entry that is marked
7108 as is-statement, even if it matches the non-statement one we just
7111 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7112 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7113 ecs
->event_thread
->control
.may_range_step
= 1;
7114 if (refresh_step_info
)
7115 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7117 infrun_debug_printf ("keep going");
7121 /* In all-stop mode, if we're currently stepping but have stopped in
7122 some other thread, we may need to switch back to the stepped
7123 thread. Returns true we set the inferior running, false if we left
7124 it stopped (and the event needs further processing). */
7127 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7129 if (!target_is_non_stop_p ())
7131 struct thread_info
*stepping_thread
;
7133 /* If any thread is blocked on some internal breakpoint, and we
7134 simply need to step over that breakpoint to get it going
7135 again, do that first. */
7137 /* However, if we see an event for the stepping thread, then we
7138 know all other threads have been moved past their breakpoints
7139 already. Let the caller check whether the step is finished,
7140 etc., before deciding to move it past a breakpoint. */
7141 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7144 /* Check if the current thread is blocked on an incomplete
7145 step-over, interrupted by a random signal. */
7146 if (ecs
->event_thread
->control
.trap_expected
7147 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7150 ("need to finish step-over of [%s]",
7151 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7156 /* Check if the current thread is blocked by a single-step
7157 breakpoint of another thread. */
7158 if (ecs
->hit_singlestep_breakpoint
)
7160 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7161 target_pid_to_str (ecs
->ptid
).c_str ());
7166 /* If this thread needs yet another step-over (e.g., stepping
7167 through a delay slot), do it first before moving on to
7169 if (thread_still_needs_step_over (ecs
->event_thread
))
7172 ("thread [%s] still needs step-over",
7173 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7178 /* If scheduler locking applies even if not stepping, there's no
7179 need to walk over threads. Above we've checked whether the
7180 current thread is stepping. If some other thread not the
7181 event thread is stepping, then it must be that scheduler
7182 locking is not in effect. */
7183 if (schedlock_applies (ecs
->event_thread
))
7186 /* Otherwise, we no longer expect a trap in the current thread.
7187 Clear the trap_expected flag before switching back -- this is
7188 what keep_going does as well, if we call it. */
7189 ecs
->event_thread
->control
.trap_expected
= 0;
7191 /* Likewise, clear the signal if it should not be passed. */
7192 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7193 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7195 /* Do all pending step-overs before actually proceeding with
7197 if (start_step_over ())
7199 prepare_to_wait (ecs
);
7203 /* Look for the stepping/nexting thread. */
7204 stepping_thread
= NULL
;
7206 for (thread_info
*tp
: all_non_exited_threads ())
7208 switch_to_thread_no_regs (tp
);
7210 /* Ignore threads of processes the caller is not
7213 && (tp
->inf
->process_target () != ecs
->target
7214 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7217 /* When stepping over a breakpoint, we lock all threads
7218 except the one that needs to move past the breakpoint.
7219 If a non-event thread has this set, the "incomplete
7220 step-over" check above should have caught it earlier. */
7221 if (tp
->control
.trap_expected
)
7223 internal_error (__FILE__
, __LINE__
,
7224 "[%s] has inconsistent state: "
7225 "trap_expected=%d\n",
7226 target_pid_to_str (tp
->ptid
).c_str (),
7227 tp
->control
.trap_expected
);
7230 /* Did we find the stepping thread? */
7231 if (tp
->control
.step_range_end
)
7233 /* Yep. There should only one though. */
7234 gdb_assert (stepping_thread
== NULL
);
7236 /* The event thread is handled at the top, before we
7238 gdb_assert (tp
!= ecs
->event_thread
);
7240 /* If some thread other than the event thread is
7241 stepping, then scheduler locking can't be in effect,
7242 otherwise we wouldn't have resumed the current event
7243 thread in the first place. */
7244 gdb_assert (!schedlock_applies (tp
));
7246 stepping_thread
= tp
;
7250 if (stepping_thread
!= NULL
)
7252 infrun_debug_printf ("switching back to stepped thread");
7254 if (keep_going_stepped_thread (stepping_thread
))
7256 prepare_to_wait (ecs
);
7261 switch_to_thread (ecs
->event_thread
);
7267 /* Set a previously stepped thread back to stepping. Returns true on
7268 success, false if the resume is not possible (e.g., the thread
7272 keep_going_stepped_thread (struct thread_info
*tp
)
7274 struct frame_info
*frame
;
7275 struct execution_control_state ecss
;
7276 struct execution_control_state
*ecs
= &ecss
;
7278 /* If the stepping thread exited, then don't try to switch back and
7279 resume it, which could fail in several different ways depending
7280 on the target. Instead, just keep going.
7282 We can find a stepping dead thread in the thread list in two
7285 - The target supports thread exit events, and when the target
7286 tries to delete the thread from the thread list, inferior_ptid
7287 pointed at the exiting thread. In such case, calling
7288 delete_thread does not really remove the thread from the list;
7289 instead, the thread is left listed, with 'exited' state.
7291 - The target's debug interface does not support thread exit
7292 events, and so we have no idea whatsoever if the previously
7293 stepping thread is still alive. For that reason, we need to
7294 synchronously query the target now. */
7296 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7298 infrun_debug_printf ("not resuming previously stepped thread, it has "
7305 infrun_debug_printf ("resuming previously stepped thread");
7307 reset_ecs (ecs
, tp
);
7308 switch_to_thread (tp
);
7310 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7311 frame
= get_current_frame ();
7313 /* If the PC of the thread we were trying to single-step has
7314 changed, then that thread has trapped or been signaled, but the
7315 event has not been reported to GDB yet. Re-poll the target
7316 looking for this particular thread's event (i.e. temporarily
7317 enable schedlock) by:
7319 - setting a break at the current PC
7320 - resuming that particular thread, only (by setting trap
7323 This prevents us continuously moving the single-step breakpoint
7324 forward, one instruction at a time, overstepping. */
7326 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7330 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7331 paddress (target_gdbarch (), tp
->prev_pc
),
7332 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7334 /* Clear the info of the previous step-over, as it's no longer
7335 valid (if the thread was trying to step over a breakpoint, it
7336 has already succeeded). It's what keep_going would do too,
7337 if we called it. Do this before trying to insert the sss
7338 breakpoint, otherwise if we were previously trying to step
7339 over this exact address in another thread, the breakpoint is
7341 clear_step_over_info ();
7342 tp
->control
.trap_expected
= 0;
7344 insert_single_step_breakpoint (get_frame_arch (frame
),
7345 get_frame_address_space (frame
),
7346 tp
->suspend
.stop_pc
);
7349 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7350 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7354 infrun_debug_printf ("expected thread still hasn't advanced");
7356 keep_going_pass_signal (ecs
);
7361 /* Is thread TP in the middle of (software or hardware)
7362 single-stepping? (Note the result of this function must never be
7363 passed directly as target_resume's STEP parameter.) */
7366 currently_stepping (struct thread_info
*tp
)
7368 return ((tp
->control
.step_range_end
7369 && tp
->control
.step_resume_breakpoint
== NULL
)
7370 || tp
->control
.trap_expected
7371 || tp
->stepped_breakpoint
7372 || bpstat_should_step ());
7375 /* Inferior has stepped into a subroutine call with source code that
7376 we should not step over. Do step to the first line of code in
7380 handle_step_into_function (struct gdbarch
*gdbarch
,
7381 struct execution_control_state
*ecs
)
7383 fill_in_stop_func (gdbarch
, ecs
);
7385 compunit_symtab
*cust
7386 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7387 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7388 ecs
->stop_func_start
7389 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7391 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7392 /* Use the step_resume_break to step until the end of the prologue,
7393 even if that involves jumps (as it seems to on the vax under
7395 /* If the prologue ends in the middle of a source line, continue to
7396 the end of that source line (if it is still within the function).
7397 Otherwise, just go to end of prologue. */
7398 if (stop_func_sal
.end
7399 && stop_func_sal
.pc
!= ecs
->stop_func_start
7400 && stop_func_sal
.end
< ecs
->stop_func_end
)
7401 ecs
->stop_func_start
= stop_func_sal
.end
;
7403 /* Architectures which require breakpoint adjustment might not be able
7404 to place a breakpoint at the computed address. If so, the test
7405 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7406 ecs->stop_func_start to an address at which a breakpoint may be
7407 legitimately placed.
7409 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7410 made, GDB will enter an infinite loop when stepping through
7411 optimized code consisting of VLIW instructions which contain
7412 subinstructions corresponding to different source lines. On
7413 FR-V, it's not permitted to place a breakpoint on any but the
7414 first subinstruction of a VLIW instruction. When a breakpoint is
7415 set, GDB will adjust the breakpoint address to the beginning of
7416 the VLIW instruction. Thus, we need to make the corresponding
7417 adjustment here when computing the stop address. */
7419 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7421 ecs
->stop_func_start
7422 = gdbarch_adjust_breakpoint_address (gdbarch
,
7423 ecs
->stop_func_start
);
7426 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7428 /* We are already there: stop now. */
7429 end_stepping_range (ecs
);
7434 /* Put the step-breakpoint there and go until there. */
7435 symtab_and_line sr_sal
;
7436 sr_sal
.pc
= ecs
->stop_func_start
;
7437 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7438 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7440 /* Do not specify what the fp should be when we stop since on
7441 some machines the prologue is where the new fp value is
7443 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7445 /* And make sure stepping stops right away then. */
7446 ecs
->event_thread
->control
.step_range_end
7447 = ecs
->event_thread
->control
.step_range_start
;
7452 /* Inferior has stepped backward into a subroutine call with source
7453 code that we should not step over. Do step to the beginning of the
7454 last line of code in it. */
7457 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7458 struct execution_control_state
*ecs
)
7460 struct compunit_symtab
*cust
;
7461 struct symtab_and_line stop_func_sal
;
7463 fill_in_stop_func (gdbarch
, ecs
);
7465 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7466 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7467 ecs
->stop_func_start
7468 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7470 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7472 /* OK, we're just going to keep stepping here. */
7473 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7475 /* We're there already. Just stop stepping now. */
7476 end_stepping_range (ecs
);
7480 /* Else just reset the step range and keep going.
7481 No step-resume breakpoint, they don't work for
7482 epilogues, which can have multiple entry paths. */
7483 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7484 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7490 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7491 This is used to both functions and to skip over code. */
7494 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7495 struct symtab_and_line sr_sal
,
7496 struct frame_id sr_id
,
7497 enum bptype sr_type
)
7499 /* There should never be more than one step-resume or longjmp-resume
7500 breakpoint per thread, so we should never be setting a new
7501 step_resume_breakpoint when one is already active. */
7502 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7503 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7505 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7506 paddress (gdbarch
, sr_sal
.pc
));
7508 inferior_thread ()->control
.step_resume_breakpoint
7509 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7513 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7514 struct symtab_and_line sr_sal
,
7515 struct frame_id sr_id
)
7517 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7522 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7523 This is used to skip a potential signal handler.
7525 This is called with the interrupted function's frame. The signal
7526 handler, when it returns, will resume the interrupted function at
7530 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7532 gdb_assert (return_frame
!= NULL
);
7534 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7536 symtab_and_line sr_sal
;
7537 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7538 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7539 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7541 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7542 get_stack_frame_id (return_frame
),
7546 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7547 is used to skip a function after stepping into it (for "next" or if
7548 the called function has no debugging information).
7550 The current function has almost always been reached by single
7551 stepping a call or return instruction. NEXT_FRAME belongs to the
7552 current function, and the breakpoint will be set at the caller's
7555 This is a separate function rather than reusing
7556 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7557 get_prev_frame, which may stop prematurely (see the implementation
7558 of frame_unwind_caller_id for an example). */
7561 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7563 /* We shouldn't have gotten here if we don't know where the call site
7565 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7567 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7569 symtab_and_line sr_sal
;
7570 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7571 frame_unwind_caller_pc (next_frame
));
7572 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7573 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7575 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7576 frame_unwind_caller_id (next_frame
));
7579 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7580 new breakpoint at the target of a jmp_buf. The handling of
7581 longjmp-resume uses the same mechanisms used for handling
7582 "step-resume" breakpoints. */
7585 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7587 /* There should never be more than one longjmp-resume breakpoint per
7588 thread, so we should never be setting a new
7589 longjmp_resume_breakpoint when one is already active. */
7590 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7592 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7593 paddress (gdbarch
, pc
));
7595 inferior_thread ()->control
.exception_resume_breakpoint
=
7596 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7599 /* Insert an exception resume breakpoint. TP is the thread throwing
7600 the exception. The block B is the block of the unwinder debug hook
7601 function. FRAME is the frame corresponding to the call to this
7602 function. SYM is the symbol of the function argument holding the
7603 target PC of the exception. */
7606 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7607 const struct block
*b
,
7608 struct frame_info
*frame
,
7613 struct block_symbol vsym
;
7614 struct value
*value
;
7616 struct breakpoint
*bp
;
7618 vsym
= lookup_symbol_search_name (sym
->search_name (),
7620 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7621 /* If the value was optimized out, revert to the old behavior. */
7622 if (! value_optimized_out (value
))
7624 handler
= value_as_address (value
);
7626 infrun_debug_printf ("exception resume at %lx",
7627 (unsigned long) handler
);
7629 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7631 bp_exception_resume
).release ();
7633 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7636 bp
->thread
= tp
->global_num
;
7637 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7640 catch (const gdb_exception_error
&e
)
7642 /* We want to ignore errors here. */
7646 /* A helper for check_exception_resume that sets an
7647 exception-breakpoint based on a SystemTap probe. */
7650 insert_exception_resume_from_probe (struct thread_info
*tp
,
7651 const struct bound_probe
*probe
,
7652 struct frame_info
*frame
)
7654 struct value
*arg_value
;
7656 struct breakpoint
*bp
;
7658 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7662 handler
= value_as_address (arg_value
);
7664 infrun_debug_printf ("exception resume at %s",
7665 paddress (probe
->objfile
->arch (), handler
));
7667 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7668 handler
, bp_exception_resume
).release ();
7669 bp
->thread
= tp
->global_num
;
7670 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7673 /* This is called when an exception has been intercepted. Check to
7674 see whether the exception's destination is of interest, and if so,
7675 set an exception resume breakpoint there. */
7678 check_exception_resume (struct execution_control_state
*ecs
,
7679 struct frame_info
*frame
)
7681 struct bound_probe probe
;
7682 struct symbol
*func
;
7684 /* First see if this exception unwinding breakpoint was set via a
7685 SystemTap probe point. If so, the probe has two arguments: the
7686 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7687 set a breakpoint there. */
7688 probe
= find_probe_by_pc (get_frame_pc (frame
));
7691 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7695 func
= get_frame_function (frame
);
7701 const struct block
*b
;
7702 struct block_iterator iter
;
7706 /* The exception breakpoint is a thread-specific breakpoint on
7707 the unwinder's debug hook, declared as:
7709 void _Unwind_DebugHook (void *cfa, void *handler);
7711 The CFA argument indicates the frame to which control is
7712 about to be transferred. HANDLER is the destination PC.
7714 We ignore the CFA and set a temporary breakpoint at HANDLER.
7715 This is not extremely efficient but it avoids issues in gdb
7716 with computing the DWARF CFA, and it also works even in weird
7717 cases such as throwing an exception from inside a signal
7720 b
= SYMBOL_BLOCK_VALUE (func
);
7721 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7723 if (!SYMBOL_IS_ARGUMENT (sym
))
7730 insert_exception_resume_breakpoint (ecs
->event_thread
,
7736 catch (const gdb_exception_error
&e
)
7742 stop_waiting (struct execution_control_state
*ecs
)
7744 infrun_debug_printf ("stop_waiting");
7746 /* Let callers know we don't want to wait for the inferior anymore. */
7747 ecs
->wait_some_more
= 0;
7749 /* If all-stop, but there exists a non-stop target, stop all
7750 threads now that we're presenting the stop to the user. */
7751 if (!non_stop
&& exists_non_stop_target ())
7752 stop_all_threads ();
7755 /* Like keep_going, but passes the signal to the inferior, even if the
7756 signal is set to nopass. */
7759 keep_going_pass_signal (struct execution_control_state
*ecs
)
7761 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7762 gdb_assert (!ecs
->event_thread
->resumed
);
7764 /* Save the pc before execution, to compare with pc after stop. */
7765 ecs
->event_thread
->prev_pc
7766 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7768 if (ecs
->event_thread
->control
.trap_expected
)
7770 struct thread_info
*tp
= ecs
->event_thread
;
7772 infrun_debug_printf ("%s has trap_expected set, "
7773 "resuming to collect trap",
7774 target_pid_to_str (tp
->ptid
).c_str ());
7776 /* We haven't yet gotten our trap, and either: intercepted a
7777 non-signal event (e.g., a fork); or took a signal which we
7778 are supposed to pass through to the inferior. Simply
7780 resume (ecs
->event_thread
->suspend
.stop_signal
);
7782 else if (step_over_info_valid_p ())
7784 /* Another thread is stepping over a breakpoint in-line. If
7785 this thread needs a step-over too, queue the request. In
7786 either case, this resume must be deferred for later. */
7787 struct thread_info
*tp
= ecs
->event_thread
;
7789 if (ecs
->hit_singlestep_breakpoint
7790 || thread_still_needs_step_over (tp
))
7792 infrun_debug_printf ("step-over already in progress: "
7793 "step-over for %s deferred",
7794 target_pid_to_str (tp
->ptid
).c_str ());
7795 thread_step_over_chain_enqueue (tp
);
7799 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7800 target_pid_to_str (tp
->ptid
).c_str ());
7805 struct regcache
*regcache
= get_current_regcache ();
7808 step_over_what step_what
;
7810 /* Either the trap was not expected, but we are continuing
7811 anyway (if we got a signal, the user asked it be passed to
7814 We got our expected trap, but decided we should resume from
7817 We're going to run this baby now!
7819 Note that insert_breakpoints won't try to re-insert
7820 already inserted breakpoints. Therefore, we don't
7821 care if breakpoints were already inserted, or not. */
7823 /* If we need to step over a breakpoint, and we're not using
7824 displaced stepping to do so, insert all breakpoints
7825 (watchpoints, etc.) but the one we're stepping over, step one
7826 instruction, and then re-insert the breakpoint when that step
7829 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7831 remove_bp
= (ecs
->hit_singlestep_breakpoint
7832 || (step_what
& STEP_OVER_BREAKPOINT
));
7833 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7835 /* We can't use displaced stepping if we need to step past a
7836 watchpoint. The instruction copied to the scratch pad would
7837 still trigger the watchpoint. */
7839 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7841 set_step_over_info (regcache
->aspace (),
7842 regcache_read_pc (regcache
), remove_wps
,
7843 ecs
->event_thread
->global_num
);
7845 else if (remove_wps
)
7846 set_step_over_info (NULL
, 0, remove_wps
, -1);
7848 /* If we now need to do an in-line step-over, we need to stop
7849 all other threads. Note this must be done before
7850 insert_breakpoints below, because that removes the breakpoint
7851 we're about to step over, otherwise other threads could miss
7853 if (step_over_info_valid_p () && target_is_non_stop_p ())
7854 stop_all_threads ();
7856 /* Stop stepping if inserting breakpoints fails. */
7859 insert_breakpoints ();
7861 catch (const gdb_exception_error
&e
)
7863 exception_print (gdb_stderr
, e
);
7865 clear_step_over_info ();
7869 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7871 resume (ecs
->event_thread
->suspend
.stop_signal
);
7874 prepare_to_wait (ecs
);
7877 /* Called when we should continue running the inferior, because the
7878 current event doesn't cause a user visible stop. This does the
7879 resuming part; waiting for the next event is done elsewhere. */
7882 keep_going (struct execution_control_state
*ecs
)
7884 if (ecs
->event_thread
->control
.trap_expected
7885 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7886 ecs
->event_thread
->control
.trap_expected
= 0;
7888 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7889 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7890 keep_going_pass_signal (ecs
);
7893 /* This function normally comes after a resume, before
7894 handle_inferior_event exits. It takes care of any last bits of
7895 housekeeping, and sets the all-important wait_some_more flag. */
7898 prepare_to_wait (struct execution_control_state
*ecs
)
7900 infrun_debug_printf ("prepare_to_wait");
7902 ecs
->wait_some_more
= 1;
7904 /* If the target can't async, emulate it by marking the infrun event
7905 handler such that as soon as we get back to the event-loop, we
7906 immediately end up in fetch_inferior_event again calling
7908 if (!target_can_async_p ())
7909 mark_infrun_async_event_handler ();
7912 /* We are done with the step range of a step/next/si/ni command.
7913 Called once for each n of a "step n" operation. */
7916 end_stepping_range (struct execution_control_state
*ecs
)
7918 ecs
->event_thread
->control
.stop_step
= 1;
7922 /* Several print_*_reason functions to print why the inferior has stopped.
7923 We always print something when the inferior exits, or receives a signal.
7924 The rest of the cases are dealt with later on in normal_stop and
7925 print_it_typical. Ideally there should be a call to one of these
7926 print_*_reason functions functions from handle_inferior_event each time
7927 stop_waiting is called.
7929 Note that we don't call these directly, instead we delegate that to
7930 the interpreters, through observers. Interpreters then call these
7931 with whatever uiout is right. */
7934 print_end_stepping_range_reason (struct ui_out
*uiout
)
7936 /* For CLI-like interpreters, print nothing. */
7938 if (uiout
->is_mi_like_p ())
7940 uiout
->field_string ("reason",
7941 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7946 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7948 annotate_signalled ();
7949 if (uiout
->is_mi_like_p ())
7951 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7952 uiout
->text ("\nProgram terminated with signal ");
7953 annotate_signal_name ();
7954 uiout
->field_string ("signal-name",
7955 gdb_signal_to_name (siggnal
));
7956 annotate_signal_name_end ();
7958 annotate_signal_string ();
7959 uiout
->field_string ("signal-meaning",
7960 gdb_signal_to_string (siggnal
));
7961 annotate_signal_string_end ();
7962 uiout
->text (".\n");
7963 uiout
->text ("The program no longer exists.\n");
7967 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7969 struct inferior
*inf
= current_inferior ();
7970 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7972 annotate_exited (exitstatus
);
7975 if (uiout
->is_mi_like_p ())
7976 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7977 std::string exit_code_str
7978 = string_printf ("0%o", (unsigned int) exitstatus
);
7979 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7980 plongest (inf
->num
), pidstr
.c_str (),
7981 string_field ("exit-code", exit_code_str
.c_str ()));
7985 if (uiout
->is_mi_like_p ())
7987 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7988 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7989 plongest (inf
->num
), pidstr
.c_str ());
7994 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7996 struct thread_info
*thr
= inferior_thread ();
8000 if (uiout
->is_mi_like_p ())
8002 else if (show_thread_that_caused_stop ())
8006 uiout
->text ("\nThread ");
8007 uiout
->field_string ("thread-id", print_thread_id (thr
));
8009 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8012 uiout
->text (" \"");
8013 uiout
->field_string ("name", name
);
8018 uiout
->text ("\nProgram");
8020 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8021 uiout
->text (" stopped");
8024 uiout
->text (" received signal ");
8025 annotate_signal_name ();
8026 if (uiout
->is_mi_like_p ())
8028 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8029 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8030 annotate_signal_name_end ();
8032 annotate_signal_string ();
8033 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8035 struct regcache
*regcache
= get_current_regcache ();
8036 struct gdbarch
*gdbarch
= regcache
->arch ();
8037 if (gdbarch_report_signal_info_p (gdbarch
))
8038 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8040 annotate_signal_string_end ();
8042 uiout
->text (".\n");
8046 print_no_history_reason (struct ui_out
*uiout
)
8048 uiout
->text ("\nNo more reverse-execution history.\n");
8051 /* Print current location without a level number, if we have changed
8052 functions or hit a breakpoint. Print source line if we have one.
8053 bpstat_print contains the logic deciding in detail what to print,
8054 based on the event(s) that just occurred. */
8057 print_stop_location (struct target_waitstatus
*ws
)
8060 enum print_what source_flag
;
8061 int do_frame_printing
= 1;
8062 struct thread_info
*tp
= inferior_thread ();
8064 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8068 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8069 should) carry around the function and does (or should) use
8070 that when doing a frame comparison. */
8071 if (tp
->control
.stop_step
8072 && frame_id_eq (tp
->control
.step_frame_id
,
8073 get_frame_id (get_current_frame ()))
8074 && (tp
->control
.step_start_function
8075 == find_pc_function (tp
->suspend
.stop_pc
)))
8077 /* Finished step, just print source line. */
8078 source_flag
= SRC_LINE
;
8082 /* Print location and source line. */
8083 source_flag
= SRC_AND_LOC
;
8086 case PRINT_SRC_AND_LOC
:
8087 /* Print location and source line. */
8088 source_flag
= SRC_AND_LOC
;
8090 case PRINT_SRC_ONLY
:
8091 source_flag
= SRC_LINE
;
8094 /* Something bogus. */
8095 source_flag
= SRC_LINE
;
8096 do_frame_printing
= 0;
8099 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8102 /* The behavior of this routine with respect to the source
8104 SRC_LINE: Print only source line
8105 LOCATION: Print only location
8106 SRC_AND_LOC: Print location and source line. */
8107 if (do_frame_printing
)
8108 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8114 print_stop_event (struct ui_out
*uiout
, bool displays
)
8116 struct target_waitstatus last
;
8117 struct thread_info
*tp
;
8119 get_last_target_status (nullptr, nullptr, &last
);
8122 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8124 print_stop_location (&last
);
8126 /* Display the auto-display expressions. */
8131 tp
= inferior_thread ();
8132 if (tp
->thread_fsm
!= NULL
8133 && tp
->thread_fsm
->finished_p ())
8135 struct return_value_info
*rv
;
8137 rv
= tp
->thread_fsm
->return_value ();
8139 print_return_value (uiout
, rv
);
8146 maybe_remove_breakpoints (void)
8148 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8150 if (remove_breakpoints ())
8152 target_terminal::ours_for_output ();
8153 printf_filtered (_("Cannot remove breakpoints because "
8154 "program is no longer writable.\nFurther "
8155 "execution is probably impossible.\n"));
8160 /* The execution context that just caused a normal stop. */
8167 DISABLE_COPY_AND_ASSIGN (stop_context
);
8169 bool changed () const;
8174 /* The event PTID. */
8178 /* If stopp for a thread event, this is the thread that caused the
8180 struct thread_info
*thread
;
8182 /* The inferior that caused the stop. */
8186 /* Initializes a new stop context. If stopped for a thread event, this
8187 takes a strong reference to the thread. */
8189 stop_context::stop_context ()
8191 stop_id
= get_stop_id ();
8192 ptid
= inferior_ptid
;
8193 inf_num
= current_inferior ()->num
;
8195 if (inferior_ptid
!= null_ptid
)
8197 /* Take a strong reference so that the thread can't be deleted
8199 thread
= inferior_thread ();
8206 /* Release a stop context previously created with save_stop_context.
8207 Releases the strong reference to the thread as well. */
8209 stop_context::~stop_context ()
8215 /* Return true if the current context no longer matches the saved stop
8219 stop_context::changed () const
8221 if (ptid
!= inferior_ptid
)
8223 if (inf_num
!= current_inferior ()->num
)
8225 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8227 if (get_stop_id () != stop_id
)
8237 struct target_waitstatus last
;
8239 get_last_target_status (nullptr, nullptr, &last
);
8243 /* If an exception is thrown from this point on, make sure to
8244 propagate GDB's knowledge of the executing state to the
8245 frontend/user running state. A QUIT is an easy exception to see
8246 here, so do this before any filtered output. */
8248 ptid_t finish_ptid
= null_ptid
;
8251 finish_ptid
= minus_one_ptid
;
8252 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8253 || last
.kind
== TARGET_WAITKIND_EXITED
)
8255 /* On some targets, we may still have live threads in the
8256 inferior when we get a process exit event. E.g., for
8257 "checkpoint", when the current checkpoint/fork exits,
8258 linux-fork.c automatically switches to another fork from
8259 within target_mourn_inferior. */
8260 if (inferior_ptid
!= null_ptid
)
8261 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8263 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8264 finish_ptid
= inferior_ptid
;
8266 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8267 if (finish_ptid
!= null_ptid
)
8269 maybe_finish_thread_state
.emplace
8270 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8273 /* As we're presenting a stop, and potentially removing breakpoints,
8274 update the thread list so we can tell whether there are threads
8275 running on the target. With target remote, for example, we can
8276 only learn about new threads when we explicitly update the thread
8277 list. Do this before notifying the interpreters about signal
8278 stops, end of stepping ranges, etc., so that the "new thread"
8279 output is emitted before e.g., "Program received signal FOO",
8280 instead of after. */
8281 update_thread_list ();
8283 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8284 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8286 /* As with the notification of thread events, we want to delay
8287 notifying the user that we've switched thread context until
8288 the inferior actually stops.
8290 There's no point in saying anything if the inferior has exited.
8291 Note that SIGNALLED here means "exited with a signal", not
8292 "received a signal".
8294 Also skip saying anything in non-stop mode. In that mode, as we
8295 don't want GDB to switch threads behind the user's back, to avoid
8296 races where the user is typing a command to apply to thread x,
8297 but GDB switches to thread y before the user finishes entering
8298 the command, fetch_inferior_event installs a cleanup to restore
8299 the current thread back to the thread the user had selected right
8300 after this event is handled, so we're not really switching, only
8301 informing of a stop. */
8303 && previous_inferior_ptid
!= inferior_ptid
8304 && target_has_execution
8305 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8306 && last
.kind
!= TARGET_WAITKIND_EXITED
8307 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8309 SWITCH_THRU_ALL_UIS ()
8311 target_terminal::ours_for_output ();
8312 printf_filtered (_("[Switching to %s]\n"),
8313 target_pid_to_str (inferior_ptid
).c_str ());
8314 annotate_thread_changed ();
8316 previous_inferior_ptid
= inferior_ptid
;
8319 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8321 SWITCH_THRU_ALL_UIS ()
8322 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8324 target_terminal::ours_for_output ();
8325 printf_filtered (_("No unwaited-for children left.\n"));
8329 /* Note: this depends on the update_thread_list call above. */
8330 maybe_remove_breakpoints ();
8332 /* If an auto-display called a function and that got a signal,
8333 delete that auto-display to avoid an infinite recursion. */
8335 if (stopped_by_random_signal
)
8336 disable_current_display ();
8338 SWITCH_THRU_ALL_UIS ()
8340 async_enable_stdin ();
8343 /* Let the user/frontend see the threads as stopped. */
8344 maybe_finish_thread_state
.reset ();
8346 /* Select innermost stack frame - i.e., current frame is frame 0,
8347 and current location is based on that. Handle the case where the
8348 dummy call is returning after being stopped. E.g. the dummy call
8349 previously hit a breakpoint. (If the dummy call returns
8350 normally, we won't reach here.) Do this before the stop hook is
8351 run, so that it doesn't get to see the temporary dummy frame,
8352 which is not where we'll present the stop. */
8353 if (has_stack_frames ())
8355 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8357 /* Pop the empty frame that contains the stack dummy. This
8358 also restores inferior state prior to the call (struct
8359 infcall_suspend_state). */
8360 struct frame_info
*frame
= get_current_frame ();
8362 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8364 /* frame_pop calls reinit_frame_cache as the last thing it
8365 does which means there's now no selected frame. */
8368 select_frame (get_current_frame ());
8370 /* Set the current source location. */
8371 set_current_sal_from_frame (get_current_frame ());
8374 /* Look up the hook_stop and run it (CLI internally handles problem
8375 of stop_command's pre-hook not existing). */
8376 if (stop_command
!= NULL
)
8378 stop_context saved_context
;
8382 execute_cmd_pre_hook (stop_command
);
8384 catch (const gdb_exception
&ex
)
8386 exception_fprintf (gdb_stderr
, ex
,
8387 "Error while running hook_stop:\n");
8390 /* If the stop hook resumes the target, then there's no point in
8391 trying to notify about the previous stop; its context is
8392 gone. Likewise if the command switches thread or inferior --
8393 the observers would print a stop for the wrong
8395 if (saved_context
.changed ())
8399 /* Notify observers about the stop. This is where the interpreters
8400 print the stop event. */
8401 if (inferior_ptid
!= null_ptid
)
8402 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8405 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8407 annotate_stopped ();
8409 if (target_has_execution
)
8411 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8412 && last
.kind
!= TARGET_WAITKIND_EXITED
8413 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8414 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8415 Delete any breakpoint that is to be deleted at the next stop. */
8416 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8419 /* Try to get rid of automatically added inferiors that are no
8420 longer needed. Keeping those around slows down things linearly.
8421 Note that this never removes the current inferior. */
8428 signal_stop_state (int signo
)
8430 return signal_stop
[signo
];
8434 signal_print_state (int signo
)
8436 return signal_print
[signo
];
8440 signal_pass_state (int signo
)
8442 return signal_program
[signo
];
8446 signal_cache_update (int signo
)
8450 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8451 signal_cache_update (signo
);
8456 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8457 && signal_print
[signo
] == 0
8458 && signal_program
[signo
] == 1
8459 && signal_catch
[signo
] == 0);
8463 signal_stop_update (int signo
, int state
)
8465 int ret
= signal_stop
[signo
];
8467 signal_stop
[signo
] = state
;
8468 signal_cache_update (signo
);
8473 signal_print_update (int signo
, int state
)
8475 int ret
= signal_print
[signo
];
8477 signal_print
[signo
] = state
;
8478 signal_cache_update (signo
);
8483 signal_pass_update (int signo
, int state
)
8485 int ret
= signal_program
[signo
];
8487 signal_program
[signo
] = state
;
8488 signal_cache_update (signo
);
8492 /* Update the global 'signal_catch' from INFO and notify the
8496 signal_catch_update (const unsigned int *info
)
8500 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8501 signal_catch
[i
] = info
[i
] > 0;
8502 signal_cache_update (-1);
8503 target_pass_signals (signal_pass
);
8507 sig_print_header (void)
8509 printf_filtered (_("Signal Stop\tPrint\tPass "
8510 "to program\tDescription\n"));
8514 sig_print_info (enum gdb_signal oursig
)
8516 const char *name
= gdb_signal_to_name (oursig
);
8517 int name_padding
= 13 - strlen (name
);
8519 if (name_padding
<= 0)
8522 printf_filtered ("%s", name
);
8523 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8524 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8525 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8526 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8527 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8530 /* Specify how various signals in the inferior should be handled. */
8533 handle_command (const char *args
, int from_tty
)
8535 int digits
, wordlen
;
8536 int sigfirst
, siglast
;
8537 enum gdb_signal oursig
;
8542 error_no_arg (_("signal to handle"));
8545 /* Allocate and zero an array of flags for which signals to handle. */
8547 const size_t nsigs
= GDB_SIGNAL_LAST
;
8548 unsigned char sigs
[nsigs
] {};
8550 /* Break the command line up into args. */
8552 gdb_argv
built_argv (args
);
8554 /* Walk through the args, looking for signal oursigs, signal names, and
8555 actions. Signal numbers and signal names may be interspersed with
8556 actions, with the actions being performed for all signals cumulatively
8557 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8559 for (char *arg
: built_argv
)
8561 wordlen
= strlen (arg
);
8562 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8566 sigfirst
= siglast
= -1;
8568 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8570 /* Apply action to all signals except those used by the
8571 debugger. Silently skip those. */
8574 siglast
= nsigs
- 1;
8576 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8578 SET_SIGS (nsigs
, sigs
, signal_stop
);
8579 SET_SIGS (nsigs
, sigs
, signal_print
);
8581 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8583 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8585 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8587 SET_SIGS (nsigs
, sigs
, signal_print
);
8589 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8591 SET_SIGS (nsigs
, sigs
, signal_program
);
8593 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8595 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8597 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8599 SET_SIGS (nsigs
, sigs
, signal_program
);
8601 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8603 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8604 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8606 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8608 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8610 else if (digits
> 0)
8612 /* It is numeric. The numeric signal refers to our own
8613 internal signal numbering from target.h, not to host/target
8614 signal number. This is a feature; users really should be
8615 using symbolic names anyway, and the common ones like
8616 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8618 sigfirst
= siglast
= (int)
8619 gdb_signal_from_command (atoi (arg
));
8620 if (arg
[digits
] == '-')
8623 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8625 if (sigfirst
> siglast
)
8627 /* Bet he didn't figure we'd think of this case... */
8628 std::swap (sigfirst
, siglast
);
8633 oursig
= gdb_signal_from_name (arg
);
8634 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8636 sigfirst
= siglast
= (int) oursig
;
8640 /* Not a number and not a recognized flag word => complain. */
8641 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8645 /* If any signal numbers or symbol names were found, set flags for
8646 which signals to apply actions to. */
8648 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8650 switch ((enum gdb_signal
) signum
)
8652 case GDB_SIGNAL_TRAP
:
8653 case GDB_SIGNAL_INT
:
8654 if (!allsigs
&& !sigs
[signum
])
8656 if (query (_("%s is used by the debugger.\n\
8657 Are you sure you want to change it? "),
8658 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8663 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8667 case GDB_SIGNAL_DEFAULT
:
8668 case GDB_SIGNAL_UNKNOWN
:
8669 /* Make sure that "all" doesn't print these. */
8678 for (int signum
= 0; signum
< nsigs
; signum
++)
8681 signal_cache_update (-1);
8682 target_pass_signals (signal_pass
);
8683 target_program_signals (signal_program
);
8687 /* Show the results. */
8688 sig_print_header ();
8689 for (; signum
< nsigs
; signum
++)
8691 sig_print_info ((enum gdb_signal
) signum
);
8698 /* Complete the "handle" command. */
8701 handle_completer (struct cmd_list_element
*ignore
,
8702 completion_tracker
&tracker
,
8703 const char *text
, const char *word
)
8705 static const char * const keywords
[] =
8719 signal_completer (ignore
, tracker
, text
, word
);
8720 complete_on_enum (tracker
, keywords
, word
, word
);
8724 gdb_signal_from_command (int num
)
8726 if (num
>= 1 && num
<= 15)
8727 return (enum gdb_signal
) num
;
8728 error (_("Only signals 1-15 are valid as numeric signals.\n\
8729 Use \"info signals\" for a list of symbolic signals."));
8732 /* Print current contents of the tables set by the handle command.
8733 It is possible we should just be printing signals actually used
8734 by the current target (but for things to work right when switching
8735 targets, all signals should be in the signal tables). */
8738 info_signals_command (const char *signum_exp
, int from_tty
)
8740 enum gdb_signal oursig
;
8742 sig_print_header ();
8746 /* First see if this is a symbol name. */
8747 oursig
= gdb_signal_from_name (signum_exp
);
8748 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8750 /* No, try numeric. */
8752 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8754 sig_print_info (oursig
);
8758 printf_filtered ("\n");
8759 /* These ugly casts brought to you by the native VAX compiler. */
8760 for (oursig
= GDB_SIGNAL_FIRST
;
8761 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8762 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8766 if (oursig
!= GDB_SIGNAL_UNKNOWN
8767 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8768 sig_print_info (oursig
);
8771 printf_filtered (_("\nUse the \"handle\" command "
8772 "to change these tables.\n"));
8775 /* The $_siginfo convenience variable is a bit special. We don't know
8776 for sure the type of the value until we actually have a chance to
8777 fetch the data. The type can change depending on gdbarch, so it is
8778 also dependent on which thread you have selected.
8780 1. making $_siginfo be an internalvar that creates a new value on
8783 2. making the value of $_siginfo be an lval_computed value. */
8785 /* This function implements the lval_computed support for reading a
8789 siginfo_value_read (struct value
*v
)
8791 LONGEST transferred
;
8793 /* If we can access registers, so can we access $_siginfo. Likewise
8795 validate_registers_access ();
8798 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8800 value_contents_all_raw (v
),
8802 TYPE_LENGTH (value_type (v
)));
8804 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8805 error (_("Unable to read siginfo"));
8808 /* This function implements the lval_computed support for writing a
8812 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8814 LONGEST transferred
;
8816 /* If we can access registers, so can we access $_siginfo. Likewise
8818 validate_registers_access ();
8820 transferred
= target_write (current_top_target (),
8821 TARGET_OBJECT_SIGNAL_INFO
,
8823 value_contents_all_raw (fromval
),
8825 TYPE_LENGTH (value_type (fromval
)));
8827 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8828 error (_("Unable to write siginfo"));
8831 static const struct lval_funcs siginfo_value_funcs
=
8837 /* Return a new value with the correct type for the siginfo object of
8838 the current thread using architecture GDBARCH. Return a void value
8839 if there's no object available. */
8841 static struct value
*
8842 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8845 if (target_has_stack
8846 && inferior_ptid
!= null_ptid
8847 && gdbarch_get_siginfo_type_p (gdbarch
))
8849 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8851 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8854 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8858 /* infcall_suspend_state contains state about the program itself like its
8859 registers and any signal it received when it last stopped.
8860 This state must be restored regardless of how the inferior function call
8861 ends (either successfully, or after it hits a breakpoint or signal)
8862 if the program is to properly continue where it left off. */
8864 class infcall_suspend_state
8867 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8868 once the inferior function call has finished. */
8869 infcall_suspend_state (struct gdbarch
*gdbarch
,
8870 const struct thread_info
*tp
,
8871 struct regcache
*regcache
)
8872 : m_thread_suspend (tp
->suspend
),
8873 m_registers (new readonly_detached_regcache (*regcache
))
8875 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8877 if (gdbarch_get_siginfo_type_p (gdbarch
))
8879 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8880 size_t len
= TYPE_LENGTH (type
);
8882 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8884 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8885 siginfo_data
.get (), 0, len
) != len
)
8887 /* Errors ignored. */
8888 siginfo_data
.reset (nullptr);
8894 m_siginfo_gdbarch
= gdbarch
;
8895 m_siginfo_data
= std::move (siginfo_data
);
8899 /* Return a pointer to the stored register state. */
8901 readonly_detached_regcache
*registers () const
8903 return m_registers
.get ();
8906 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8908 void restore (struct gdbarch
*gdbarch
,
8909 struct thread_info
*tp
,
8910 struct regcache
*regcache
) const
8912 tp
->suspend
= m_thread_suspend
;
8914 if (m_siginfo_gdbarch
== gdbarch
)
8916 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8918 /* Errors ignored. */
8919 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8920 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8923 /* The inferior can be gone if the user types "print exit(0)"
8924 (and perhaps other times). */
8925 if (target_has_execution
)
8926 /* NB: The register write goes through to the target. */
8927 regcache
->restore (registers ());
8931 /* How the current thread stopped before the inferior function call was
8933 struct thread_suspend_state m_thread_suspend
;
8935 /* The registers before the inferior function call was executed. */
8936 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8938 /* Format of SIGINFO_DATA or NULL if it is not present. */
8939 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8941 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8942 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8943 content would be invalid. */
8944 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8947 infcall_suspend_state_up
8948 save_infcall_suspend_state ()
8950 struct thread_info
*tp
= inferior_thread ();
8951 struct regcache
*regcache
= get_current_regcache ();
8952 struct gdbarch
*gdbarch
= regcache
->arch ();
8954 infcall_suspend_state_up inf_state
8955 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8957 /* Having saved the current state, adjust the thread state, discarding
8958 any stop signal information. The stop signal is not useful when
8959 starting an inferior function call, and run_inferior_call will not use
8960 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8961 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8966 /* Restore inferior session state to INF_STATE. */
8969 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8971 struct thread_info
*tp
= inferior_thread ();
8972 struct regcache
*regcache
= get_current_regcache ();
8973 struct gdbarch
*gdbarch
= regcache
->arch ();
8975 inf_state
->restore (gdbarch
, tp
, regcache
);
8976 discard_infcall_suspend_state (inf_state
);
8980 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8985 readonly_detached_regcache
*
8986 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8988 return inf_state
->registers ();
8991 /* infcall_control_state contains state regarding gdb's control of the
8992 inferior itself like stepping control. It also contains session state like
8993 the user's currently selected frame. */
8995 struct infcall_control_state
8997 struct thread_control_state thread_control
;
8998 struct inferior_control_state inferior_control
;
9001 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9002 int stopped_by_random_signal
= 0;
9004 /* ID if the selected frame when the inferior function call was made. */
9005 struct frame_id selected_frame_id
{};
9008 /* Save all of the information associated with the inferior<==>gdb
9011 infcall_control_state_up
9012 save_infcall_control_state ()
9014 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9015 struct thread_info
*tp
= inferior_thread ();
9016 struct inferior
*inf
= current_inferior ();
9018 inf_status
->thread_control
= tp
->control
;
9019 inf_status
->inferior_control
= inf
->control
;
9021 tp
->control
.step_resume_breakpoint
= NULL
;
9022 tp
->control
.exception_resume_breakpoint
= NULL
;
9024 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9025 chain. If caller's caller is walking the chain, they'll be happier if we
9026 hand them back the original chain when restore_infcall_control_state is
9028 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9031 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9032 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9034 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9040 restore_selected_frame (const frame_id
&fid
)
9042 frame_info
*frame
= frame_find_by_id (fid
);
9044 /* If inf_status->selected_frame_id is NULL, there was no previously
9048 warning (_("Unable to restore previously selected frame."));
9052 select_frame (frame
);
9055 /* Restore inferior session state to INF_STATUS. */
9058 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9060 struct thread_info
*tp
= inferior_thread ();
9061 struct inferior
*inf
= current_inferior ();
9063 if (tp
->control
.step_resume_breakpoint
)
9064 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9066 if (tp
->control
.exception_resume_breakpoint
)
9067 tp
->control
.exception_resume_breakpoint
->disposition
9068 = disp_del_at_next_stop
;
9070 /* Handle the bpstat_copy of the chain. */
9071 bpstat_clear (&tp
->control
.stop_bpstat
);
9073 tp
->control
= inf_status
->thread_control
;
9074 inf
->control
= inf_status
->inferior_control
;
9077 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9078 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9080 if (target_has_stack
)
9082 /* The point of the try/catch is that if the stack is clobbered,
9083 walking the stack might encounter a garbage pointer and
9084 error() trying to dereference it. */
9087 restore_selected_frame (inf_status
->selected_frame_id
);
9089 catch (const gdb_exception_error
&ex
)
9091 exception_fprintf (gdb_stderr
, ex
,
9092 "Unable to restore previously selected frame:\n");
9093 /* Error in restoring the selected frame. Select the
9095 select_frame (get_current_frame ());
9103 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9105 if (inf_status
->thread_control
.step_resume_breakpoint
)
9106 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9107 = disp_del_at_next_stop
;
9109 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9110 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9111 = disp_del_at_next_stop
;
9113 /* See save_infcall_control_state for info on stop_bpstat. */
9114 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9122 clear_exit_convenience_vars (void)
9124 clear_internalvar (lookup_internalvar ("_exitsignal"));
9125 clear_internalvar (lookup_internalvar ("_exitcode"));
9129 /* User interface for reverse debugging:
9130 Set exec-direction / show exec-direction commands
9131 (returns error unless target implements to_set_exec_direction method). */
9133 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9134 static const char exec_forward
[] = "forward";
9135 static const char exec_reverse
[] = "reverse";
9136 static const char *exec_direction
= exec_forward
;
9137 static const char *const exec_direction_names
[] = {
9144 set_exec_direction_func (const char *args
, int from_tty
,
9145 struct cmd_list_element
*cmd
)
9147 if (target_can_execute_reverse
)
9149 if (!strcmp (exec_direction
, exec_forward
))
9150 execution_direction
= EXEC_FORWARD
;
9151 else if (!strcmp (exec_direction
, exec_reverse
))
9152 execution_direction
= EXEC_REVERSE
;
9156 exec_direction
= exec_forward
;
9157 error (_("Target does not support this operation."));
9162 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9163 struct cmd_list_element
*cmd
, const char *value
)
9165 switch (execution_direction
) {
9167 fprintf_filtered (out
, _("Forward.\n"));
9170 fprintf_filtered (out
, _("Reverse.\n"));
9173 internal_error (__FILE__
, __LINE__
,
9174 _("bogus execution_direction value: %d"),
9175 (int) execution_direction
);
9180 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9181 struct cmd_list_element
*c
, const char *value
)
9183 fprintf_filtered (file
, _("Resuming the execution of threads "
9184 "of all processes is %s.\n"), value
);
9187 /* Implementation of `siginfo' variable. */
9189 static const struct internalvar_funcs siginfo_funcs
=
9196 /* Callback for infrun's target events source. This is marked when a
9197 thread has a pending status to process. */
9200 infrun_async_inferior_event_handler (gdb_client_data data
)
9202 inferior_event_handler (INF_REG_EVENT
);
9209 /* Verify that when two threads with the same ptid exist (from two different
9210 targets) and one of them changes ptid, we only update inferior_ptid if
9211 it is appropriate. */
9214 infrun_thread_ptid_changed ()
9216 gdbarch
*arch
= current_inferior ()->gdbarch
;
9218 /* The thread which inferior_ptid represents changes ptid. */
9220 scoped_restore_current_pspace_and_thread restore
;
9222 scoped_mock_context
<test_target_ops
> target1 (arch
);
9223 scoped_mock_context
<test_target_ops
> target2 (arch
);
9224 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9226 ptid_t
old_ptid (111, 222);
9227 ptid_t
new_ptid (111, 333);
9229 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9230 target1
.mock_thread
.ptid
= old_ptid
;
9231 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9232 target2
.mock_thread
.ptid
= old_ptid
;
9234 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9235 set_current_inferior (&target1
.mock_inferior
);
9237 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9239 gdb_assert (inferior_ptid
== new_ptid
);
9242 /* A thread with the same ptid as inferior_ptid, but from another target,
9245 scoped_restore_current_pspace_and_thread restore
;
9247 scoped_mock_context
<test_target_ops
> target1 (arch
);
9248 scoped_mock_context
<test_target_ops
> target2 (arch
);
9249 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9251 ptid_t
old_ptid (111, 222);
9252 ptid_t
new_ptid (111, 333);
9254 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9255 target1
.mock_thread
.ptid
= old_ptid
;
9256 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9257 target2
.mock_thread
.ptid
= old_ptid
;
9259 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9260 set_current_inferior (&target2
.mock_inferior
);
9262 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9264 gdb_assert (inferior_ptid
== old_ptid
);
9268 } /* namespace selftests */
9270 #endif /* GDB_SELF_TEST */
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
);