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"
73 #include "gdbsupport/common-debug.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 /* Some architectures like AArch64 Morello have the LSB set for addresses
1722 in the text segment (pure capability ABI). */
1723 copy
= gdbarch_addr_bits_remove (gdbarch
, copy
);
1724 len
= gdbarch_max_insn_length (gdbarch
);
1726 if (breakpoint_in_range_p (aspace
, copy
, len
))
1728 /* There's a breakpoint set in the scratch pad location range
1729 (which is usually around the entry point). We'd either
1730 install it before resuming, which would overwrite/corrupt the
1731 scratch pad, or if it was already inserted, this displaced
1732 step would overwrite it. The latter is OK in the sense that
1733 we already assume that no thread is going to execute the code
1734 in the scratch pad range (after initial startup) anyway, but
1735 the former is unacceptable. Simply punt and fallback to
1736 stepping over this breakpoint in-line. */
1737 if (debug_displaced
)
1739 fprintf_unfiltered (gdb_stdlog
,
1740 "displaced: breakpoint set in scratch pad. "
1741 "Stepping over breakpoint in-line instead.\n");
1747 /* Save the original contents of the copy area. */
1748 displaced
->step_saved_copy
.resize (len
);
1749 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1751 throw_error (MEMORY_ERROR
,
1752 _("Error accessing memory address %s (%s) for "
1753 "displaced-stepping scratch space."),
1754 paddress (gdbarch
, copy
), safe_strerror (status
));
1755 if (debug_displaced
)
1757 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1758 paddress (gdbarch
, copy
));
1759 displaced_step_dump_bytes (gdb_stdlog
,
1760 displaced
->step_saved_copy
.data (),
1764 displaced
->step_closure
1765 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1766 if (displaced
->step_closure
== NULL
)
1768 /* The architecture doesn't know how or want to displaced step
1769 this instruction or instruction sequence. Fallback to
1770 stepping over the breakpoint in-line. */
1774 /* Save the information we need to fix things up if the step
1776 displaced
->step_thread
= tp
;
1777 displaced
->step_gdbarch
= gdbarch
;
1778 displaced
->step_original
= original
;
1779 displaced
->step_copy
= copy
;
1782 displaced_step_reset_cleanup
cleanup (displaced
);
1784 /* Resume execution at the copy. */
1785 regcache_write_pc (regcache
, copy
);
1790 if (debug_displaced
)
1791 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1792 paddress (gdbarch
, copy
));
1797 /* Wrapper for displaced_step_prepare_throw that disabled further
1798 attempts at displaced stepping if we get a memory error. */
1801 displaced_step_prepare (thread_info
*thread
)
1807 prepared
= displaced_step_prepare_throw (thread
);
1809 catch (const gdb_exception_error
&ex
)
1811 struct displaced_step_inferior_state
*displaced_state
;
1813 if (ex
.error
!= MEMORY_ERROR
1814 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1817 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1820 /* Be verbose if "set displaced-stepping" is "on", silent if
1822 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1824 warning (_("disabling displaced stepping: %s"),
1828 /* Disable further displaced stepping attempts. */
1830 = get_displaced_stepping_state (thread
->inf
);
1831 displaced_state
->failed_before
= 1;
1838 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1839 const gdb_byte
*myaddr
, int len
)
1841 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1843 inferior_ptid
= ptid
;
1844 write_memory (memaddr
, myaddr
, len
);
1847 /* Restore the contents of the copy area for thread PTID. */
1850 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1853 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1855 write_memory_ptid (ptid
, displaced
->step_copy
,
1856 displaced
->step_saved_copy
.data (), len
);
1857 if (debug_displaced
)
1858 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1859 target_pid_to_str (ptid
).c_str (),
1860 paddress (displaced
->step_gdbarch
,
1861 displaced
->step_copy
));
1864 /* If we displaced stepped an instruction successfully, adjust
1865 registers and memory to yield the same effect the instruction would
1866 have had if we had executed it at its original address, and return
1867 1. If the instruction didn't complete, relocate the PC and return
1868 -1. If the thread wasn't displaced stepping, return 0. */
1871 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1873 struct displaced_step_inferior_state
*displaced
1874 = get_displaced_stepping_state (event_thread
->inf
);
1877 /* Was this event for the thread we displaced? */
1878 if (displaced
->step_thread
!= event_thread
)
1881 /* Fixup may need to read memory/registers. Switch to the thread
1882 that we're fixing up. Also, target_stopped_by_watchpoint checks
1883 the current thread, and displaced_step_restore performs ptid-dependent
1884 memory accesses using current_inferior() and current_top_target(). */
1885 switch_to_thread (event_thread
);
1887 displaced_step_reset_cleanup
cleanup (displaced
);
1889 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1891 /* Did the instruction complete successfully? */
1892 if (signal
== GDB_SIGNAL_TRAP
1893 && !(target_stopped_by_watchpoint ()
1894 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1895 || target_have_steppable_watchpoint ())))
1897 /* Fix up the resulting state. */
1898 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1899 displaced
->step_closure
.get (),
1900 displaced
->step_original
,
1901 displaced
->step_copy
,
1902 get_thread_regcache (displaced
->step_thread
));
1907 /* Since the instruction didn't complete, all we can do is
1909 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1910 CORE_ADDR pc
= regcache_read_pc (regcache
);
1912 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1913 regcache_write_pc (regcache
, pc
);
1920 /* Data to be passed around while handling an event. This data is
1921 discarded between events. */
1922 struct execution_control_state
1924 process_stratum_target
*target
;
1926 /* The thread that got the event, if this was a thread event; NULL
1928 struct thread_info
*event_thread
;
1930 struct target_waitstatus ws
;
1931 int stop_func_filled_in
;
1932 CORE_ADDR stop_func_start
;
1933 CORE_ADDR stop_func_end
;
1934 const char *stop_func_name
;
1937 /* True if the event thread hit the single-step breakpoint of
1938 another thread. Thus the event doesn't cause a stop, the thread
1939 needs to be single-stepped past the single-step breakpoint before
1940 we can switch back to the original stepping thread. */
1941 int hit_singlestep_breakpoint
;
1944 /* Clear ECS and set it to point at TP. */
1947 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1949 memset (ecs
, 0, sizeof (*ecs
));
1950 ecs
->event_thread
= tp
;
1951 ecs
->ptid
= tp
->ptid
;
1954 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1955 static void prepare_to_wait (struct execution_control_state
*ecs
);
1956 static int keep_going_stepped_thread (struct thread_info
*tp
);
1957 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1959 /* Are there any pending step-over requests? If so, run all we can
1960 now and return true. Otherwise, return false. */
1963 start_step_over (void)
1965 struct thread_info
*tp
, *next
;
1967 /* Don't start a new step-over if we already have an in-line
1968 step-over operation ongoing. */
1969 if (step_over_info_valid_p ())
1972 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1974 struct execution_control_state ecss
;
1975 struct execution_control_state
*ecs
= &ecss
;
1976 step_over_what step_what
;
1977 int must_be_in_line
;
1979 gdb_assert (!tp
->stop_requested
);
1981 next
= thread_step_over_chain_next (tp
);
1983 /* If this inferior already has a displaced step in process,
1984 don't start a new one. */
1985 if (displaced_step_in_progress (tp
->inf
))
1988 step_what
= thread_still_needs_step_over (tp
);
1989 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1990 || ((step_what
& STEP_OVER_BREAKPOINT
)
1991 && !use_displaced_stepping (tp
)));
1993 /* We currently stop all threads of all processes to step-over
1994 in-line. If we need to start a new in-line step-over, let
1995 any pending displaced steps finish first. */
1996 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1999 thread_step_over_chain_remove (tp
);
2001 if (step_over_queue_head
== NULL
)
2002 infrun_debug_printf ("step-over queue now empty");
2004 if (tp
->control
.trap_expected
2008 internal_error (__FILE__
, __LINE__
,
2009 "[%s] has inconsistent state: "
2010 "trap_expected=%d, resumed=%d, executing=%d\n",
2011 target_pid_to_str (tp
->ptid
).c_str (),
2012 tp
->control
.trap_expected
,
2017 infrun_debug_printf ("resuming [%s] for step-over",
2018 target_pid_to_str (tp
->ptid
).c_str ());
2020 /* keep_going_pass_signal skips the step-over if the breakpoint
2021 is no longer inserted. In all-stop, we want to keep looking
2022 for a thread that needs a step-over instead of resuming TP,
2023 because we wouldn't be able to resume anything else until the
2024 target stops again. In non-stop, the resume always resumes
2025 only TP, so it's OK to let the thread resume freely. */
2026 if (!target_is_non_stop_p () && !step_what
)
2029 switch_to_thread (tp
);
2030 reset_ecs (ecs
, tp
);
2031 keep_going_pass_signal (ecs
);
2033 if (!ecs
->wait_some_more
)
2034 error (_("Command aborted."));
2036 gdb_assert (tp
->resumed
);
2038 /* If we started a new in-line step-over, we're done. */
2039 if (step_over_info_valid_p ())
2041 gdb_assert (tp
->control
.trap_expected
);
2045 if (!target_is_non_stop_p ())
2047 /* On all-stop, shouldn't have resumed unless we needed a
2049 gdb_assert (tp
->control
.trap_expected
2050 || tp
->step_after_step_resume_breakpoint
);
2052 /* With remote targets (at least), in all-stop, we can't
2053 issue any further remote commands until the program stops
2058 /* Either the thread no longer needed a step-over, or a new
2059 displaced stepping sequence started. Even in the latter
2060 case, continue looking. Maybe we can also start another
2061 displaced step on a thread of other process. */
2067 /* Update global variables holding ptids to hold NEW_PTID if they were
2068 holding OLD_PTID. */
2070 infrun_thread_ptid_changed (process_stratum_target
*target
,
2071 ptid_t old_ptid
, ptid_t new_ptid
)
2073 if (inferior_ptid
== old_ptid
2074 && current_inferior ()->process_target () == target
)
2075 inferior_ptid
= new_ptid
;
2080 static const char schedlock_off
[] = "off";
2081 static const char schedlock_on
[] = "on";
2082 static const char schedlock_step
[] = "step";
2083 static const char schedlock_replay
[] = "replay";
2084 static const char *const scheduler_enums
[] = {
2091 static const char *scheduler_mode
= schedlock_replay
;
2093 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2094 struct cmd_list_element
*c
, const char *value
)
2096 fprintf_filtered (file
,
2097 _("Mode for locking scheduler "
2098 "during execution is \"%s\".\n"),
2103 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2105 if (!target_can_lock_scheduler ())
2107 scheduler_mode
= schedlock_off
;
2108 error (_("Target '%s' cannot support this command."), target_shortname
);
2112 /* True if execution commands resume all threads of all processes by
2113 default; otherwise, resume only threads of the current inferior
2115 bool sched_multi
= false;
2117 /* Try to setup for software single stepping over the specified location.
2118 Return 1 if target_resume() should use hardware single step.
2120 GDBARCH the current gdbarch.
2121 PC the location to step over. */
2124 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2128 if (execution_direction
== EXEC_FORWARD
2129 && gdbarch_software_single_step_p (gdbarch
))
2130 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2138 user_visible_resume_ptid (int step
)
2144 /* With non-stop mode on, threads are always handled
2146 resume_ptid
= inferior_ptid
;
2148 else if ((scheduler_mode
== schedlock_on
)
2149 || (scheduler_mode
== schedlock_step
&& step
))
2151 /* User-settable 'scheduler' mode requires solo thread
2153 resume_ptid
= inferior_ptid
;
2155 else if ((scheduler_mode
== schedlock_replay
)
2156 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2158 /* User-settable 'scheduler' mode requires solo thread resume in replay
2160 resume_ptid
= inferior_ptid
;
2162 else if (!sched_multi
&& target_supports_multi_process ())
2164 /* Resume all threads of the current process (and none of other
2166 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2170 /* Resume all threads of all processes. */
2171 resume_ptid
= RESUME_ALL
;
2179 process_stratum_target
*
2180 user_visible_resume_target (ptid_t resume_ptid
)
2182 return (resume_ptid
== minus_one_ptid
&& sched_multi
2184 : current_inferior ()->process_target ());
2187 /* Return a ptid representing the set of threads that we will resume,
2188 in the perspective of the target, assuming run control handling
2189 does not require leaving some threads stopped (e.g., stepping past
2190 breakpoint). USER_STEP indicates whether we're about to start the
2191 target for a stepping command. */
2194 internal_resume_ptid (int user_step
)
2196 /* In non-stop, we always control threads individually. Note that
2197 the target may always work in non-stop mode even with "set
2198 non-stop off", in which case user_visible_resume_ptid could
2199 return a wildcard ptid. */
2200 if (target_is_non_stop_p ())
2201 return inferior_ptid
;
2203 return user_visible_resume_ptid (user_step
);
2206 /* Wrapper for target_resume, that handles infrun-specific
2210 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2212 struct thread_info
*tp
= inferior_thread ();
2214 gdb_assert (!tp
->stop_requested
);
2216 /* Install inferior's terminal modes. */
2217 target_terminal::inferior ();
2219 /* Avoid confusing the next resume, if the next stop/resume
2220 happens to apply to another thread. */
2221 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2223 /* Advise target which signals may be handled silently.
2225 If we have removed breakpoints because we are stepping over one
2226 in-line (in any thread), we need to receive all signals to avoid
2227 accidentally skipping a breakpoint during execution of a signal
2230 Likewise if we're displaced stepping, otherwise a trap for a
2231 breakpoint in a signal handler might be confused with the
2232 displaced step finishing. We don't make the displaced_step_fixup
2233 step distinguish the cases instead, because:
2235 - a backtrace while stopped in the signal handler would show the
2236 scratch pad as frame older than the signal handler, instead of
2237 the real mainline code.
2239 - when the thread is later resumed, the signal handler would
2240 return to the scratch pad area, which would no longer be
2242 if (step_over_info_valid_p ()
2243 || displaced_step_in_progress (tp
->inf
))
2244 target_pass_signals ({});
2246 target_pass_signals (signal_pass
);
2248 target_resume (resume_ptid
, step
, sig
);
2250 target_commit_resume ();
2252 if (target_can_async_p ())
2256 /* Resume the inferior. SIG is the signal to give the inferior
2257 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2258 call 'resume', which handles exceptions. */
2261 resume_1 (enum gdb_signal sig
)
2263 struct regcache
*regcache
= get_current_regcache ();
2264 struct gdbarch
*gdbarch
= regcache
->arch ();
2265 struct thread_info
*tp
= inferior_thread ();
2266 const address_space
*aspace
= regcache
->aspace ();
2268 /* This represents the user's step vs continue request. When
2269 deciding whether "set scheduler-locking step" applies, it's the
2270 user's intention that counts. */
2271 const int user_step
= tp
->control
.stepping_command
;
2272 /* This represents what we'll actually request the target to do.
2273 This can decay from a step to a continue, if e.g., we need to
2274 implement single-stepping with breakpoints (software
2278 gdb_assert (!tp
->stop_requested
);
2279 gdb_assert (!thread_is_in_step_over_chain (tp
));
2281 if (tp
->suspend
.waitstatus_pending_p
)
2284 ("thread %s has pending wait "
2285 "status %s (currently_stepping=%d).",
2286 target_pid_to_str (tp
->ptid
).c_str (),
2287 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2288 currently_stepping (tp
));
2290 tp
->inf
->process_target ()->threads_executing
= true;
2293 /* FIXME: What should we do if we are supposed to resume this
2294 thread with a signal? Maybe we should maintain a queue of
2295 pending signals to deliver. */
2296 if (sig
!= GDB_SIGNAL_0
)
2298 warning (_("Couldn't deliver signal %s to %s."),
2299 gdb_signal_to_name (sig
),
2300 target_pid_to_str (tp
->ptid
).c_str ());
2303 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2305 if (target_can_async_p ())
2308 /* Tell the event loop we have an event to process. */
2309 mark_async_event_handler (infrun_async_inferior_event_token
);
2314 tp
->stepped_breakpoint
= 0;
2316 /* Depends on stepped_breakpoint. */
2317 step
= currently_stepping (tp
);
2319 if (current_inferior ()->waiting_for_vfork_done
)
2321 /* Don't try to single-step a vfork parent that is waiting for
2322 the child to get out of the shared memory region (by exec'ing
2323 or exiting). This is particularly important on software
2324 single-step archs, as the child process would trip on the
2325 software single step breakpoint inserted for the parent
2326 process. Since the parent will not actually execute any
2327 instruction until the child is out of the shared region (such
2328 are vfork's semantics), it is safe to simply continue it.
2329 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2330 the parent, and tell it to `keep_going', which automatically
2331 re-sets it stepping. */
2332 infrun_debug_printf ("resume : clear step");
2336 CORE_ADDR pc
= regcache_read_pc (regcache
);
2338 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2339 "current thread [%s] at %s",
2340 step
, gdb_signal_to_symbol_string (sig
),
2341 tp
->control
.trap_expected
,
2342 target_pid_to_str (inferior_ptid
).c_str (),
2343 paddress (gdbarch
, pc
));
2345 /* Normally, by the time we reach `resume', the breakpoints are either
2346 removed or inserted, as appropriate. The exception is if we're sitting
2347 at a permanent breakpoint; we need to step over it, but permanent
2348 breakpoints can't be removed. So we have to test for it here. */
2349 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2351 if (sig
!= GDB_SIGNAL_0
)
2353 /* We have a signal to pass to the inferior. The resume
2354 may, or may not take us to the signal handler. If this
2355 is a step, we'll need to stop in the signal handler, if
2356 there's one, (if the target supports stepping into
2357 handlers), or in the next mainline instruction, if
2358 there's no handler. If this is a continue, we need to be
2359 sure to run the handler with all breakpoints inserted.
2360 In all cases, set a breakpoint at the current address
2361 (where the handler returns to), and once that breakpoint
2362 is hit, resume skipping the permanent breakpoint. If
2363 that breakpoint isn't hit, then we've stepped into the
2364 signal handler (or hit some other event). We'll delete
2365 the step-resume breakpoint then. */
2367 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2368 "deliver signal first");
2370 clear_step_over_info ();
2371 tp
->control
.trap_expected
= 0;
2373 if (tp
->control
.step_resume_breakpoint
== NULL
)
2375 /* Set a "high-priority" step-resume, as we don't want
2376 user breakpoints at PC to trigger (again) when this
2378 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2379 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2381 tp
->step_after_step_resume_breakpoint
= step
;
2384 insert_breakpoints ();
2388 /* There's no signal to pass, we can go ahead and skip the
2389 permanent breakpoint manually. */
2390 infrun_debug_printf ("skipping permanent breakpoint");
2391 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2392 /* Update pc to reflect the new address from which we will
2393 execute instructions. */
2394 pc
= regcache_read_pc (regcache
);
2398 /* We've already advanced the PC, so the stepping part
2399 is done. Now we need to arrange for a trap to be
2400 reported to handle_inferior_event. Set a breakpoint
2401 at the current PC, and run to it. Don't update
2402 prev_pc, because if we end in
2403 switch_back_to_stepped_thread, we want the "expected
2404 thread advanced also" branch to be taken. IOW, we
2405 don't want this thread to step further from PC
2407 gdb_assert (!step_over_info_valid_p ());
2408 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2409 insert_breakpoints ();
2411 resume_ptid
= internal_resume_ptid (user_step
);
2412 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2419 /* If we have a breakpoint to step over, make sure to do a single
2420 step only. Same if we have software watchpoints. */
2421 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2422 tp
->control
.may_range_step
= 0;
2424 /* If displaced stepping is enabled, step over breakpoints by executing a
2425 copy of the instruction at a different address.
2427 We can't use displaced stepping when we have a signal to deliver;
2428 the comments for displaced_step_prepare explain why. The
2429 comments in the handle_inferior event for dealing with 'random
2430 signals' explain what we do instead.
2432 We can't use displaced stepping when we are waiting for vfork_done
2433 event, displaced stepping breaks the vfork child similarly as single
2434 step software breakpoint. */
2435 if (tp
->control
.trap_expected
2436 && use_displaced_stepping (tp
)
2437 && !step_over_info_valid_p ()
2438 && sig
== GDB_SIGNAL_0
2439 && !current_inferior ()->waiting_for_vfork_done
)
2441 int prepared
= displaced_step_prepare (tp
);
2445 infrun_debug_printf ("Got placed in step-over queue");
2447 tp
->control
.trap_expected
= 0;
2450 else if (prepared
< 0)
2452 /* Fallback to stepping over the breakpoint in-line. */
2454 if (target_is_non_stop_p ())
2455 stop_all_threads ();
2457 set_step_over_info (regcache
->aspace (),
2458 regcache_read_pc (regcache
), 0, tp
->global_num
);
2460 step
= maybe_software_singlestep (gdbarch
, pc
);
2462 insert_breakpoints ();
2464 else if (prepared
> 0)
2466 struct displaced_step_inferior_state
*displaced
;
2468 /* Update pc to reflect the new address from which we will
2469 execute instructions due to displaced stepping. */
2470 pc
= regcache_read_pc (get_thread_regcache (tp
));
2472 displaced
= get_displaced_stepping_state (tp
->inf
);
2473 step
= gdbarch_displaced_step_hw_singlestep
2474 (gdbarch
, displaced
->step_closure
.get ());
2478 /* Do we need to do it the hard way, w/temp breakpoints? */
2480 step
= maybe_software_singlestep (gdbarch
, pc
);
2482 /* Currently, our software single-step implementation leads to different
2483 results than hardware single-stepping in one situation: when stepping
2484 into delivering a signal which has an associated signal handler,
2485 hardware single-step will stop at the first instruction of the handler,
2486 while software single-step will simply skip execution of the handler.
2488 For now, this difference in behavior is accepted since there is no
2489 easy way to actually implement single-stepping into a signal handler
2490 without kernel support.
2492 However, there is one scenario where this difference leads to follow-on
2493 problems: if we're stepping off a breakpoint by removing all breakpoints
2494 and then single-stepping. In this case, the software single-step
2495 behavior means that even if there is a *breakpoint* in the signal
2496 handler, GDB still would not stop.
2498 Fortunately, we can at least fix this particular issue. We detect
2499 here the case where we are about to deliver a signal while software
2500 single-stepping with breakpoints removed. In this situation, we
2501 revert the decisions to remove all breakpoints and insert single-
2502 step breakpoints, and instead we install a step-resume breakpoint
2503 at the current address, deliver the signal without stepping, and
2504 once we arrive back at the step-resume breakpoint, actually step
2505 over the breakpoint we originally wanted to step over. */
2506 if (thread_has_single_step_breakpoints_set (tp
)
2507 && sig
!= GDB_SIGNAL_0
2508 && step_over_info_valid_p ())
2510 /* If we have nested signals or a pending signal is delivered
2511 immediately after a handler returns, might already have
2512 a step-resume breakpoint set on the earlier handler. We cannot
2513 set another step-resume breakpoint; just continue on until the
2514 original breakpoint is hit. */
2515 if (tp
->control
.step_resume_breakpoint
== NULL
)
2517 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2518 tp
->step_after_step_resume_breakpoint
= 1;
2521 delete_single_step_breakpoints (tp
);
2523 clear_step_over_info ();
2524 tp
->control
.trap_expected
= 0;
2526 insert_breakpoints ();
2529 /* If STEP is set, it's a request to use hardware stepping
2530 facilities. But in that case, we should never
2531 use singlestep breakpoint. */
2532 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2534 /* Decide the set of threads to ask the target to resume. */
2535 if (tp
->control
.trap_expected
)
2537 /* We're allowing a thread to run past a breakpoint it has
2538 hit, either by single-stepping the thread with the breakpoint
2539 removed, or by displaced stepping, with the breakpoint inserted.
2540 In the former case, we need to single-step only this thread,
2541 and keep others stopped, as they can miss this breakpoint if
2542 allowed to run. That's not really a problem for displaced
2543 stepping, but, we still keep other threads stopped, in case
2544 another thread is also stopped for a breakpoint waiting for
2545 its turn in the displaced stepping queue. */
2546 resume_ptid
= inferior_ptid
;
2549 resume_ptid
= internal_resume_ptid (user_step
);
2551 if (execution_direction
!= EXEC_REVERSE
2552 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2554 /* There are two cases where we currently need to step a
2555 breakpoint instruction when we have a signal to deliver:
2557 - See handle_signal_stop where we handle random signals that
2558 could take out us out of the stepping range. Normally, in
2559 that case we end up continuing (instead of stepping) over the
2560 signal handler with a breakpoint at PC, but there are cases
2561 where we should _always_ single-step, even if we have a
2562 step-resume breakpoint, like when a software watchpoint is
2563 set. Assuming single-stepping and delivering a signal at the
2564 same time would takes us to the signal handler, then we could
2565 have removed the breakpoint at PC to step over it. However,
2566 some hardware step targets (like e.g., Mac OS) can't step
2567 into signal handlers, and for those, we need to leave the
2568 breakpoint at PC inserted, as otherwise if the handler
2569 recurses and executes PC again, it'll miss the breakpoint.
2570 So we leave the breakpoint inserted anyway, but we need to
2571 record that we tried to step a breakpoint instruction, so
2572 that adjust_pc_after_break doesn't end up confused.
2574 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2575 in one thread after another thread that was stepping had been
2576 momentarily paused for a step-over. When we re-resume the
2577 stepping thread, it may be resumed from that address with a
2578 breakpoint that hasn't trapped yet. Seen with
2579 gdb.threads/non-stop-fair-events.exp, on targets that don't
2580 do displaced stepping. */
2582 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2583 target_pid_to_str (tp
->ptid
).c_str ());
2585 tp
->stepped_breakpoint
= 1;
2587 /* Most targets can step a breakpoint instruction, thus
2588 executing it normally. But if this one cannot, just
2589 continue and we will hit it anyway. */
2590 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2595 && tp
->control
.trap_expected
2596 && use_displaced_stepping (tp
)
2597 && !step_over_info_valid_p ())
2599 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2600 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2601 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2604 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2605 paddress (resume_gdbarch
, actual_pc
));
2606 read_memory (actual_pc
, buf
, sizeof (buf
));
2607 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2610 if (tp
->control
.may_range_step
)
2612 /* If we're resuming a thread with the PC out of the step
2613 range, then we're doing some nested/finer run control
2614 operation, like stepping the thread out of the dynamic
2615 linker or the displaced stepping scratch pad. We
2616 shouldn't have allowed a range step then. */
2617 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2620 do_target_resume (resume_ptid
, step
, sig
);
2624 /* Resume the inferior. SIG is the signal to give the inferior
2625 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2626 rolls back state on error. */
2629 resume (gdb_signal sig
)
2635 catch (const gdb_exception
&ex
)
2637 /* If resuming is being aborted for any reason, delete any
2638 single-step breakpoint resume_1 may have created, to avoid
2639 confusing the following resumption, and to avoid leaving
2640 single-step breakpoints perturbing other threads, in case
2641 we're running in non-stop mode. */
2642 if (inferior_ptid
!= null_ptid
)
2643 delete_single_step_breakpoints (inferior_thread ());
2653 /* Counter that tracks number of user visible stops. This can be used
2654 to tell whether a command has proceeded the inferior past the
2655 current location. This allows e.g., inferior function calls in
2656 breakpoint commands to not interrupt the command list. When the
2657 call finishes successfully, the inferior is standing at the same
2658 breakpoint as if nothing happened (and so we don't call
2660 static ULONGEST current_stop_id
;
2667 return current_stop_id
;
2670 /* Called when we report a user visible stop. */
2678 /* Clear out all variables saying what to do when inferior is continued.
2679 First do this, then set the ones you want, then call `proceed'. */
2682 clear_proceed_status_thread (struct thread_info
*tp
)
2684 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2686 /* If we're starting a new sequence, then the previous finished
2687 single-step is no longer relevant. */
2688 if (tp
->suspend
.waitstatus_pending_p
)
2690 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2692 infrun_debug_printf ("pending event of %s was a finished step. "
2694 target_pid_to_str (tp
->ptid
).c_str ());
2696 tp
->suspend
.waitstatus_pending_p
= 0;
2697 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2702 ("thread %s has pending wait status %s (currently_stepping=%d).",
2703 target_pid_to_str (tp
->ptid
).c_str (),
2704 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2705 currently_stepping (tp
));
2709 /* If this signal should not be seen by program, give it zero.
2710 Used for debugging signals. */
2711 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2712 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2714 delete tp
->thread_fsm
;
2715 tp
->thread_fsm
= NULL
;
2717 tp
->control
.trap_expected
= 0;
2718 tp
->control
.step_range_start
= 0;
2719 tp
->control
.step_range_end
= 0;
2720 tp
->control
.may_range_step
= 0;
2721 tp
->control
.step_frame_id
= null_frame_id
;
2722 tp
->control
.step_stack_frame_id
= null_frame_id
;
2723 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2724 tp
->control
.step_start_function
= NULL
;
2725 tp
->stop_requested
= 0;
2727 tp
->control
.stop_step
= 0;
2729 tp
->control
.proceed_to_finish
= 0;
2731 tp
->control
.stepping_command
= 0;
2733 /* Discard any remaining commands or status from previous stop. */
2734 bpstat_clear (&tp
->control
.stop_bpstat
);
2738 clear_proceed_status (int step
)
2740 /* With scheduler-locking replay, stop replaying other threads if we're
2741 not replaying the user-visible resume ptid.
2743 This is a convenience feature to not require the user to explicitly
2744 stop replaying the other threads. We're assuming that the user's
2745 intent is to resume tracing the recorded process. */
2746 if (!non_stop
&& scheduler_mode
== schedlock_replay
2747 && target_record_is_replaying (minus_one_ptid
)
2748 && !target_record_will_replay (user_visible_resume_ptid (step
),
2749 execution_direction
))
2750 target_record_stop_replaying ();
2752 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2754 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2755 process_stratum_target
*resume_target
2756 = user_visible_resume_target (resume_ptid
);
2758 /* In all-stop mode, delete the per-thread status of all threads
2759 we're about to resume, implicitly and explicitly. */
2760 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2761 clear_proceed_status_thread (tp
);
2764 if (inferior_ptid
!= null_ptid
)
2766 struct inferior
*inferior
;
2770 /* If in non-stop mode, only delete the per-thread status of
2771 the current thread. */
2772 clear_proceed_status_thread (inferior_thread ());
2775 inferior
= current_inferior ();
2776 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2779 gdb::observers::about_to_proceed
.notify ();
2782 /* Returns true if TP is still stopped at a breakpoint that needs
2783 stepping-over in order to make progress. If the breakpoint is gone
2784 meanwhile, we can skip the whole step-over dance. */
2787 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2789 if (tp
->stepping_over_breakpoint
)
2791 struct regcache
*regcache
= get_thread_regcache (tp
);
2793 if (breakpoint_here_p (regcache
->aspace (),
2794 regcache_read_pc (regcache
))
2795 == ordinary_breakpoint_here
)
2798 tp
->stepping_over_breakpoint
= 0;
2804 /* Check whether thread TP still needs to start a step-over in order
2805 to make progress when resumed. Returns an bitwise or of enum
2806 step_over_what bits, indicating what needs to be stepped over. */
2808 static step_over_what
2809 thread_still_needs_step_over (struct thread_info
*tp
)
2811 step_over_what what
= 0;
2813 if (thread_still_needs_step_over_bp (tp
))
2814 what
|= STEP_OVER_BREAKPOINT
;
2816 if (tp
->stepping_over_watchpoint
2817 && !target_have_steppable_watchpoint ())
2818 what
|= STEP_OVER_WATCHPOINT
;
2823 /* Returns true if scheduler locking applies. STEP indicates whether
2824 we're about to do a step/next-like command to a thread. */
2827 schedlock_applies (struct thread_info
*tp
)
2829 return (scheduler_mode
== schedlock_on
2830 || (scheduler_mode
== schedlock_step
2831 && tp
->control
.stepping_command
)
2832 || (scheduler_mode
== schedlock_replay
2833 && target_record_will_replay (minus_one_ptid
,
2834 execution_direction
)));
2837 /* Calls target_commit_resume on all targets. */
2840 commit_resume_all_targets ()
2842 scoped_restore_current_thread restore_thread
;
2844 /* Map between process_target and a representative inferior. This
2845 is to avoid committing a resume in the same target more than
2846 once. Resumptions must be idempotent, so this is an
2848 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2850 for (inferior
*inf
: all_non_exited_inferiors ())
2851 if (inf
->has_execution ())
2852 conn_inf
[inf
->process_target ()] = inf
;
2854 for (const auto &ci
: conn_inf
)
2856 inferior
*inf
= ci
.second
;
2857 switch_to_inferior_no_thread (inf
);
2858 target_commit_resume ();
2862 /* Check that all the targets we're about to resume are in non-stop
2863 mode. Ideally, we'd only care whether all targets support
2864 target-async, but we're not there yet. E.g., stop_all_threads
2865 doesn't know how to handle all-stop targets. Also, the remote
2866 protocol in all-stop mode is synchronous, irrespective of
2867 target-async, which means that things like a breakpoint re-set
2868 triggered by one target would try to read memory from all targets
2872 check_multi_target_resumption (process_stratum_target
*resume_target
)
2874 if (!non_stop
&& resume_target
== nullptr)
2876 scoped_restore_current_thread restore_thread
;
2878 /* This is used to track whether we're resuming more than one
2880 process_stratum_target
*first_connection
= nullptr;
2882 /* The first inferior we see with a target that does not work in
2883 always-non-stop mode. */
2884 inferior
*first_not_non_stop
= nullptr;
2886 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2888 switch_to_inferior_no_thread (inf
);
2890 if (!target_has_execution ())
2893 process_stratum_target
*proc_target
2894 = current_inferior ()->process_target();
2896 if (!target_is_non_stop_p ())
2897 first_not_non_stop
= inf
;
2899 if (first_connection
== nullptr)
2900 first_connection
= proc_target
;
2901 else if (first_connection
!= proc_target
2902 && first_not_non_stop
!= nullptr)
2904 switch_to_inferior_no_thread (first_not_non_stop
);
2906 proc_target
= current_inferior ()->process_target();
2908 error (_("Connection %d (%s) does not support "
2909 "multi-target resumption."),
2910 proc_target
->connection_number
,
2911 make_target_connection_string (proc_target
).c_str ());
2917 /* Basic routine for continuing the program in various fashions.
2919 ADDR is the address to resume at, or -1 for resume where stopped.
2920 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2921 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2923 You should call clear_proceed_status before calling proceed. */
2926 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2928 struct regcache
*regcache
;
2929 struct gdbarch
*gdbarch
;
2931 struct execution_control_state ecss
;
2932 struct execution_control_state
*ecs
= &ecss
;
2935 /* If we're stopped at a fork/vfork, follow the branch set by the
2936 "set follow-fork-mode" command; otherwise, we'll just proceed
2937 resuming the current thread. */
2938 if (!follow_fork ())
2940 /* The target for some reason decided not to resume. */
2942 if (target_can_async_p ())
2943 inferior_event_handler (INF_EXEC_COMPLETE
);
2947 /* We'll update this if & when we switch to a new thread. */
2948 previous_inferior_ptid
= inferior_ptid
;
2950 regcache
= get_current_regcache ();
2951 gdbarch
= regcache
->arch ();
2952 const address_space
*aspace
= regcache
->aspace ();
2954 pc
= regcache_read_pc_protected (regcache
);
2956 thread_info
*cur_thr
= inferior_thread ();
2958 /* Fill in with reasonable starting values. */
2959 init_thread_stepping_state (cur_thr
);
2961 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2964 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2965 process_stratum_target
*resume_target
2966 = user_visible_resume_target (resume_ptid
);
2968 check_multi_target_resumption (resume_target
);
2970 if (addr
== (CORE_ADDR
) -1)
2972 if (pc
== cur_thr
->suspend
.stop_pc
2973 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2974 && execution_direction
!= EXEC_REVERSE
)
2975 /* There is a breakpoint at the address we will resume at,
2976 step one instruction before inserting breakpoints so that
2977 we do not stop right away (and report a second hit at this
2980 Note, we don't do this in reverse, because we won't
2981 actually be executing the breakpoint insn anyway.
2982 We'll be (un-)executing the previous instruction. */
2983 cur_thr
->stepping_over_breakpoint
= 1;
2984 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2985 && gdbarch_single_step_through_delay (gdbarch
,
2986 get_current_frame ()))
2987 /* We stepped onto an instruction that needs to be stepped
2988 again before re-inserting the breakpoint, do so. */
2989 cur_thr
->stepping_over_breakpoint
= 1;
2993 regcache_write_pc (regcache
, addr
);
2996 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2997 cur_thr
->suspend
.stop_signal
= siggnal
;
2999 /* If an exception is thrown from this point on, make sure to
3000 propagate GDB's knowledge of the executing state to the
3001 frontend/user running state. */
3002 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3004 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3005 threads (e.g., we might need to set threads stepping over
3006 breakpoints first), from the user/frontend's point of view, all
3007 threads in RESUME_PTID are now running. Unless we're calling an
3008 inferior function, as in that case we pretend the inferior
3009 doesn't run at all. */
3010 if (!cur_thr
->control
.in_infcall
)
3011 set_running (resume_target
, resume_ptid
, true);
3013 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3014 gdb_signal_to_symbol_string (siggnal
));
3016 annotate_starting ();
3018 /* Make sure that output from GDB appears before output from the
3020 gdb_flush (gdb_stdout
);
3022 /* Since we've marked the inferior running, give it the terminal. A
3023 QUIT/Ctrl-C from here on is forwarded to the target (which can
3024 still detect attempts to unblock a stuck connection with repeated
3025 Ctrl-C from within target_pass_ctrlc). */
3026 target_terminal::inferior ();
3028 /* In a multi-threaded task we may select another thread and
3029 then continue or step.
3031 But if a thread that we're resuming had stopped at a breakpoint,
3032 it will immediately cause another breakpoint stop without any
3033 execution (i.e. it will report a breakpoint hit incorrectly). So
3034 we must step over it first.
3036 Look for threads other than the current (TP) that reported a
3037 breakpoint hit and haven't been resumed yet since. */
3039 /* If scheduler locking applies, we can avoid iterating over all
3041 if (!non_stop
&& !schedlock_applies (cur_thr
))
3043 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3046 switch_to_thread_no_regs (tp
);
3048 /* Ignore the current thread here. It's handled
3053 if (!thread_still_needs_step_over (tp
))
3056 gdb_assert (!thread_is_in_step_over_chain (tp
));
3058 infrun_debug_printf ("need to step-over [%s] first",
3059 target_pid_to_str (tp
->ptid
).c_str ());
3061 thread_step_over_chain_enqueue (tp
);
3064 switch_to_thread (cur_thr
);
3067 /* Enqueue the current thread last, so that we move all other
3068 threads over their breakpoints first. */
3069 if (cur_thr
->stepping_over_breakpoint
)
3070 thread_step_over_chain_enqueue (cur_thr
);
3072 /* If the thread isn't started, we'll still need to set its prev_pc,
3073 so that switch_back_to_stepped_thread knows the thread hasn't
3074 advanced. Must do this before resuming any thread, as in
3075 all-stop/remote, once we resume we can't send any other packet
3076 until the target stops again. */
3077 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3080 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3082 started
= start_step_over ();
3084 if (step_over_info_valid_p ())
3086 /* Either this thread started a new in-line step over, or some
3087 other thread was already doing one. In either case, don't
3088 resume anything else until the step-over is finished. */
3090 else if (started
&& !target_is_non_stop_p ())
3092 /* A new displaced stepping sequence was started. In all-stop,
3093 we can't talk to the target anymore until it next stops. */
3095 else if (!non_stop
&& target_is_non_stop_p ())
3097 /* In all-stop, but the target is always in non-stop mode.
3098 Start all other threads that are implicitly resumed too. */
3099 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3102 switch_to_thread_no_regs (tp
);
3104 if (!tp
->inf
->has_execution ())
3106 infrun_debug_printf ("[%s] target has no execution",
3107 target_pid_to_str (tp
->ptid
).c_str ());
3113 infrun_debug_printf ("[%s] resumed",
3114 target_pid_to_str (tp
->ptid
).c_str ());
3115 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3119 if (thread_is_in_step_over_chain (tp
))
3121 infrun_debug_printf ("[%s] needs step-over",
3122 target_pid_to_str (tp
->ptid
).c_str ());
3126 infrun_debug_printf ("resuming %s",
3127 target_pid_to_str (tp
->ptid
).c_str ());
3129 reset_ecs (ecs
, tp
);
3130 switch_to_thread (tp
);
3131 keep_going_pass_signal (ecs
);
3132 if (!ecs
->wait_some_more
)
3133 error (_("Command aborted."));
3136 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3138 /* The thread wasn't started, and isn't queued, run it now. */
3139 reset_ecs (ecs
, cur_thr
);
3140 switch_to_thread (cur_thr
);
3141 keep_going_pass_signal (ecs
);
3142 if (!ecs
->wait_some_more
)
3143 error (_("Command aborted."));
3147 commit_resume_all_targets ();
3149 finish_state
.release ();
3151 /* If we've switched threads above, switch back to the previously
3152 current thread. We don't want the user to see a different
3154 switch_to_thread (cur_thr
);
3156 /* Tell the event loop to wait for it to stop. If the target
3157 supports asynchronous execution, it'll do this from within
3159 if (!target_can_async_p ())
3160 mark_async_event_handler (infrun_async_inferior_event_token
);
3164 /* Start remote-debugging of a machine over a serial link. */
3167 start_remote (int from_tty
)
3169 inferior
*inf
= current_inferior ();
3170 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3172 /* Always go on waiting for the target, regardless of the mode. */
3173 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3174 indicate to wait_for_inferior that a target should timeout if
3175 nothing is returned (instead of just blocking). Because of this,
3176 targets expecting an immediate response need to, internally, set
3177 things up so that the target_wait() is forced to eventually
3179 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3180 differentiate to its caller what the state of the target is after
3181 the initial open has been performed. Here we're assuming that
3182 the target has stopped. It should be possible to eventually have
3183 target_open() return to the caller an indication that the target
3184 is currently running and GDB state should be set to the same as
3185 for an async run. */
3186 wait_for_inferior (inf
);
3188 /* Now that the inferior has stopped, do any bookkeeping like
3189 loading shared libraries. We want to do this before normal_stop,
3190 so that the displayed frame is up to date. */
3191 post_create_inferior (from_tty
);
3196 /* Initialize static vars when a new inferior begins. */
3199 init_wait_for_inferior (void)
3201 /* These are meaningless until the first time through wait_for_inferior. */
3203 breakpoint_init_inferior (inf_starting
);
3205 clear_proceed_status (0);
3207 nullify_last_target_wait_ptid ();
3209 previous_inferior_ptid
= inferior_ptid
;
3214 static void handle_inferior_event (struct execution_control_state
*ecs
);
3216 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3217 struct execution_control_state
*ecs
);
3218 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3219 struct execution_control_state
*ecs
);
3220 static void handle_signal_stop (struct execution_control_state
*ecs
);
3221 static void check_exception_resume (struct execution_control_state
*,
3222 struct frame_info
*);
3224 static void end_stepping_range (struct execution_control_state
*ecs
);
3225 static void stop_waiting (struct execution_control_state
*ecs
);
3226 static void keep_going (struct execution_control_state
*ecs
);
3227 static void process_event_stop_test (struct execution_control_state
*ecs
);
3228 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3230 /* This function is attached as a "thread_stop_requested" observer.
3231 Cleanup local state that assumed the PTID was to be resumed, and
3232 report the stop to the frontend. */
3235 infrun_thread_stop_requested (ptid_t ptid
)
3237 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3239 /* PTID was requested to stop. If the thread was already stopped,
3240 but the user/frontend doesn't know about that yet (e.g., the
3241 thread had been temporarily paused for some step-over), set up
3242 for reporting the stop now. */
3243 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3245 if (tp
->state
!= THREAD_RUNNING
)
3250 /* Remove matching threads from the step-over queue, so
3251 start_step_over doesn't try to resume them
3253 if (thread_is_in_step_over_chain (tp
))
3254 thread_step_over_chain_remove (tp
);
3256 /* If the thread is stopped, but the user/frontend doesn't
3257 know about that yet, queue a pending event, as if the
3258 thread had just stopped now. Unless the thread already had
3260 if (!tp
->suspend
.waitstatus_pending_p
)
3262 tp
->suspend
.waitstatus_pending_p
= 1;
3263 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3264 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3267 /* Clear the inline-frame state, since we're re-processing the
3269 clear_inline_frame_state (tp
);
3271 /* If this thread was paused because some other thread was
3272 doing an inline-step over, let that finish first. Once
3273 that happens, we'll restart all threads and consume pending
3274 stop events then. */
3275 if (step_over_info_valid_p ())
3278 /* Otherwise we can process the (new) pending event now. Set
3279 it so this pending event is considered by
3286 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3288 if (target_last_proc_target
== tp
->inf
->process_target ()
3289 && target_last_wait_ptid
== tp
->ptid
)
3290 nullify_last_target_wait_ptid ();
3293 /* Delete the step resume, single-step and longjmp/exception resume
3294 breakpoints of TP. */
3297 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3299 delete_step_resume_breakpoint (tp
);
3300 delete_exception_resume_breakpoint (tp
);
3301 delete_single_step_breakpoints (tp
);
3304 /* If the target still has execution, call FUNC for each thread that
3305 just stopped. In all-stop, that's all the non-exited threads; in
3306 non-stop, that's the current thread, only. */
3308 typedef void (*for_each_just_stopped_thread_callback_func
)
3309 (struct thread_info
*tp
);
3312 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3314 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3317 if (target_is_non_stop_p ())
3319 /* If in non-stop mode, only the current thread stopped. */
3320 func (inferior_thread ());
3324 /* In all-stop mode, all threads have stopped. */
3325 for (thread_info
*tp
: all_non_exited_threads ())
3330 /* Delete the step resume and longjmp/exception resume breakpoints of
3331 the threads that just stopped. */
3334 delete_just_stopped_threads_infrun_breakpoints (void)
3336 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3339 /* Delete the single-step breakpoints of the threads that just
3343 delete_just_stopped_threads_single_step_breakpoints (void)
3345 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3351 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3352 const struct target_waitstatus
*ws
)
3354 std::string status_string
= target_waitstatus_to_string (ws
);
3357 /* The text is split over several lines because it was getting too long.
3358 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3359 output as a unit; we want only one timestamp printed if debug_timestamp
3362 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3365 waiton_ptid
.tid ());
3366 if (waiton_ptid
.pid () != -1)
3367 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3368 stb
.printf (", status) =\n");
3369 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3373 target_pid_to_str (result_ptid
).c_str ());
3374 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3376 /* This uses %s in part to handle %'s in the text, but also to avoid
3377 a gcc error: the format attribute requires a string literal. */
3378 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3381 /* Select a thread at random, out of those which are resumed and have
3384 static struct thread_info
*
3385 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3389 auto has_event
= [&] (thread_info
*tp
)
3391 return (tp
->ptid
.matches (waiton_ptid
)
3393 && tp
->suspend
.waitstatus_pending_p
);
3396 /* First see how many events we have. Count only resumed threads
3397 that have an event pending. */
3398 for (thread_info
*tp
: inf
->non_exited_threads ())
3402 if (num_events
== 0)
3405 /* Now randomly pick a thread out of those that have had events. */
3406 int random_selector
= (int) ((num_events
* (double) rand ())
3407 / (RAND_MAX
+ 1.0));
3410 infrun_debug_printf ("Found %d events, selecting #%d",
3411 num_events
, random_selector
);
3413 /* Select the Nth thread that has had an event. */
3414 for (thread_info
*tp
: inf
->non_exited_threads ())
3416 if (random_selector
-- == 0)
3419 gdb_assert_not_reached ("event thread not found");
3422 /* Wrapper for target_wait that first checks whether threads have
3423 pending statuses to report before actually asking the target for
3424 more events. INF is the inferior we're using to call target_wait
3428 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3429 target_waitstatus
*status
, target_wait_flags options
)
3432 struct thread_info
*tp
;
3434 /* We know that we are looking for an event in the target of inferior
3435 INF, but we don't know which thread the event might come from. As
3436 such we want to make sure that INFERIOR_PTID is reset so that none of
3437 the wait code relies on it - doing so is always a mistake. */
3438 switch_to_inferior_no_thread (inf
);
3440 /* First check if there is a resumed thread with a wait status
3442 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3444 tp
= random_pending_event_thread (inf
, ptid
);
3448 infrun_debug_printf ("Waiting for specific thread %s.",
3449 target_pid_to_str (ptid
).c_str ());
3451 /* We have a specific thread to check. */
3452 tp
= find_thread_ptid (inf
, ptid
);
3453 gdb_assert (tp
!= NULL
);
3454 if (!tp
->suspend
.waitstatus_pending_p
)
3459 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3460 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3462 struct regcache
*regcache
= get_thread_regcache (tp
);
3463 struct gdbarch
*gdbarch
= regcache
->arch ();
3467 pc
= regcache_read_pc (regcache
);
3469 if (pc
!= tp
->suspend
.stop_pc
)
3471 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3472 target_pid_to_str (tp
->ptid
).c_str (),
3473 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3474 paddress (gdbarch
, pc
));
3477 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3479 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3480 target_pid_to_str (tp
->ptid
).c_str (),
3481 paddress (gdbarch
, pc
));
3488 infrun_debug_printf ("pending event of %s cancelled.",
3489 target_pid_to_str (tp
->ptid
).c_str ());
3491 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3492 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3498 infrun_debug_printf ("Using pending wait status %s for %s.",
3499 target_waitstatus_to_string
3500 (&tp
->suspend
.waitstatus
).c_str (),
3501 target_pid_to_str (tp
->ptid
).c_str ());
3503 /* Now that we've selected our final event LWP, un-adjust its PC
3504 if it was a software breakpoint (and the target doesn't
3505 always adjust the PC itself). */
3506 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3507 && !target_supports_stopped_by_sw_breakpoint ())
3509 struct regcache
*regcache
;
3510 struct gdbarch
*gdbarch
;
3513 regcache
= get_thread_regcache (tp
);
3514 gdbarch
= regcache
->arch ();
3516 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3521 pc
= regcache_read_pc (regcache
);
3522 regcache_write_pc (regcache
, pc
+ decr_pc
);
3526 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3527 *status
= tp
->suspend
.waitstatus
;
3528 tp
->suspend
.waitstatus_pending_p
= 0;
3530 /* Wake up the event loop again, until all pending events are
3532 if (target_is_async_p ())
3533 mark_async_event_handler (infrun_async_inferior_event_token
);
3537 /* But if we don't find one, we'll have to wait. */
3539 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3541 if (!target_can_async_p ())
3542 options
&= ~TARGET_WNOHANG
;
3544 if (deprecated_target_wait_hook
)
3545 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3547 event_ptid
= target_wait (ptid
, status
, options
);
3552 /* Wrapper for target_wait that first checks whether threads have
3553 pending statuses to report before actually asking the target for
3554 more events. Polls for events from all inferiors/targets. */
3557 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3558 target_wait_flags options
)
3560 int num_inferiors
= 0;
3561 int random_selector
;
3563 /* For fairness, we pick the first inferior/target to poll at random
3564 out of all inferiors that may report events, and then continue
3565 polling the rest of the inferior list starting from that one in a
3566 circular fashion until the whole list is polled once. */
3568 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3570 return (inf
->process_target () != NULL
3571 && ptid_t (inf
->pid
).matches (wait_ptid
));
3574 /* First see how many matching inferiors we have. */
3575 for (inferior
*inf
: all_inferiors ())
3576 if (inferior_matches (inf
))
3579 if (num_inferiors
== 0)
3581 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3585 /* Now randomly pick an inferior out of those that matched. */
3586 random_selector
= (int)
3587 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3589 if (num_inferiors
> 1)
3590 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3591 num_inferiors
, random_selector
);
3593 /* Select the Nth inferior that matched. */
3595 inferior
*selected
= nullptr;
3597 for (inferior
*inf
: all_inferiors ())
3598 if (inferior_matches (inf
))
3599 if (random_selector
-- == 0)
3605 /* Now poll for events out of each of the matching inferior's
3606 targets, starting from the selected one. */
3608 auto do_wait
= [&] (inferior
*inf
)
3610 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3611 ecs
->target
= inf
->process_target ();
3612 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3615 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3616 here spuriously after the target is all stopped and we've already
3617 reported the stop to the user, polling for events. */
3618 scoped_restore_current_thread restore_thread
;
3620 int inf_num
= selected
->num
;
3621 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3622 if (inferior_matches (inf
))
3626 for (inferior
*inf
= inferior_list
;
3627 inf
!= NULL
&& inf
->num
< inf_num
;
3629 if (inferior_matches (inf
))
3633 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3637 /* Prepare and stabilize the inferior for detaching it. E.g.,
3638 detaching while a thread is displaced stepping is a recipe for
3639 crashing it, as nothing would readjust the PC out of the scratch
3643 prepare_for_detach (void)
3645 struct inferior
*inf
= current_inferior ();
3646 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3648 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3650 /* Is any thread of this process displaced stepping? If not,
3651 there's nothing else to do. */
3652 if (displaced
->step_thread
== nullptr)
3655 infrun_debug_printf ("displaced-stepping in-process while detaching");
3657 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3659 while (displaced
->step_thread
!= nullptr)
3661 struct execution_control_state ecss
;
3662 struct execution_control_state
*ecs
;
3665 memset (ecs
, 0, sizeof (*ecs
));
3667 overlay_cache_invalid
= 1;
3668 /* Flush target cache before starting to handle each event.
3669 Target was running and cache could be stale. This is just a
3670 heuristic. Running threads may modify target memory, but we
3671 don't get any event. */
3672 target_dcache_invalidate ();
3674 do_target_wait (pid_ptid
, ecs
, 0);
3677 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3679 /* If an error happens while handling the event, propagate GDB's
3680 knowledge of the executing state to the frontend/user running
3682 scoped_finish_thread_state
finish_state (inf
->process_target (),
3685 /* Now figure out what to do with the result of the result. */
3686 handle_inferior_event (ecs
);
3688 /* No error, don't finish the state yet. */
3689 finish_state
.release ();
3691 /* Breakpoints and watchpoints are not installed on the target
3692 at this point, and signals are passed directly to the
3693 inferior, so this must mean the process is gone. */
3694 if (!ecs
->wait_some_more
)
3696 restore_detaching
.release ();
3697 error (_("Program exited while detaching"));
3701 restore_detaching
.release ();
3704 /* Wait for control to return from inferior to debugger.
3706 If inferior gets a signal, we may decide to start it up again
3707 instead of returning. That is why there is a loop in this function.
3708 When this function actually returns it means the inferior
3709 should be left stopped and GDB should read more commands. */
3712 wait_for_inferior (inferior
*inf
)
3714 infrun_debug_printf ("wait_for_inferior ()");
3716 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3718 /* If an error happens while handling the event, propagate GDB's
3719 knowledge of the executing state to the frontend/user running
3721 scoped_finish_thread_state finish_state
3722 (inf
->process_target (), minus_one_ptid
);
3726 struct execution_control_state ecss
;
3727 struct execution_control_state
*ecs
= &ecss
;
3729 memset (ecs
, 0, sizeof (*ecs
));
3731 overlay_cache_invalid
= 1;
3733 /* Flush target cache before starting to handle each event.
3734 Target was running and cache could be stale. This is just a
3735 heuristic. Running threads may modify target memory, but we
3736 don't get any event. */
3737 target_dcache_invalidate ();
3739 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3740 ecs
->target
= inf
->process_target ();
3743 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3745 /* Now figure out what to do with the result of the result. */
3746 handle_inferior_event (ecs
);
3748 if (!ecs
->wait_some_more
)
3752 /* No error, don't finish the state yet. */
3753 finish_state
.release ();
3756 /* Cleanup that reinstalls the readline callback handler, if the
3757 target is running in the background. If while handling the target
3758 event something triggered a secondary prompt, like e.g., a
3759 pagination prompt, we'll have removed the callback handler (see
3760 gdb_readline_wrapper_line). Need to do this as we go back to the
3761 event loop, ready to process further input. Note this has no
3762 effect if the handler hasn't actually been removed, because calling
3763 rl_callback_handler_install resets the line buffer, thus losing
3767 reinstall_readline_callback_handler_cleanup ()
3769 struct ui
*ui
= current_ui
;
3773 /* We're not going back to the top level event loop yet. Don't
3774 install the readline callback, as it'd prep the terminal,
3775 readline-style (raw, noecho) (e.g., --batch). We'll install
3776 it the next time the prompt is displayed, when we're ready
3781 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3782 gdb_rl_callback_handler_reinstall ();
3785 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3786 that's just the event thread. In all-stop, that's all threads. */
3789 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3791 if (ecs
->event_thread
!= NULL
3792 && ecs
->event_thread
->thread_fsm
!= NULL
)
3793 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3797 for (thread_info
*thr
: all_non_exited_threads ())
3799 if (thr
->thread_fsm
== NULL
)
3801 if (thr
== ecs
->event_thread
)
3804 switch_to_thread (thr
);
3805 thr
->thread_fsm
->clean_up (thr
);
3808 if (ecs
->event_thread
!= NULL
)
3809 switch_to_thread (ecs
->event_thread
);
3813 /* Helper for all_uis_check_sync_execution_done that works on the
3817 check_curr_ui_sync_execution_done (void)
3819 struct ui
*ui
= current_ui
;
3821 if (ui
->prompt_state
== PROMPT_NEEDED
3823 && !gdb_in_secondary_prompt_p (ui
))
3825 target_terminal::ours ();
3826 gdb::observers::sync_execution_done
.notify ();
3827 ui_register_input_event_handler (ui
);
3834 all_uis_check_sync_execution_done (void)
3836 SWITCH_THRU_ALL_UIS ()
3838 check_curr_ui_sync_execution_done ();
3845 all_uis_on_sync_execution_starting (void)
3847 SWITCH_THRU_ALL_UIS ()
3849 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3850 async_disable_stdin ();
3854 /* Asynchronous version of wait_for_inferior. It is called by the
3855 event loop whenever a change of state is detected on the file
3856 descriptor corresponding to the target. It can be called more than
3857 once to complete a single execution command. In such cases we need
3858 to keep the state in a global variable ECSS. If it is the last time
3859 that this function is called for a single execution command, then
3860 report to the user that the inferior has stopped, and do the
3861 necessary cleanups. */
3864 fetch_inferior_event ()
3866 struct execution_control_state ecss
;
3867 struct execution_control_state
*ecs
= &ecss
;
3870 memset (ecs
, 0, sizeof (*ecs
));
3872 /* Events are always processed with the main UI as current UI. This
3873 way, warnings, debug output, etc. are always consistently sent to
3874 the main console. */
3875 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3877 /* End up with readline processing input, if necessary. */
3879 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3881 /* We're handling a live event, so make sure we're doing live
3882 debugging. If we're looking at traceframes while the target is
3883 running, we're going to need to get back to that mode after
3884 handling the event. */
3885 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3888 maybe_restore_traceframe
.emplace ();
3889 set_current_traceframe (-1);
3892 /* The user/frontend should not notice a thread switch due to
3893 internal events. Make sure we revert to the user selected
3894 thread and frame after handling the event and running any
3895 breakpoint commands. */
3896 scoped_restore_current_thread restore_thread
;
3898 overlay_cache_invalid
= 1;
3899 /* Flush target cache before starting to handle each event. Target
3900 was running and cache could be stale. This is just a heuristic.
3901 Running threads may modify target memory, but we don't get any
3903 target_dcache_invalidate ();
3905 scoped_restore save_exec_dir
3906 = make_scoped_restore (&execution_direction
,
3907 target_execution_direction ());
3909 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3912 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3914 /* Switch to the target that generated the event, so we can do
3916 switch_to_target_no_thread (ecs
->target
);
3919 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3921 /* If an error happens while handling the event, propagate GDB's
3922 knowledge of the executing state to the frontend/user running
3924 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3925 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3927 /* Get executed before scoped_restore_current_thread above to apply
3928 still for the thread which has thrown the exception. */
3929 auto defer_bpstat_clear
3930 = make_scope_exit (bpstat_clear_actions
);
3931 auto defer_delete_threads
3932 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3934 /* Now figure out what to do with the result of the result. */
3935 handle_inferior_event (ecs
);
3937 if (!ecs
->wait_some_more
)
3939 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3940 int should_stop
= 1;
3941 struct thread_info
*thr
= ecs
->event_thread
;
3943 delete_just_stopped_threads_infrun_breakpoints ();
3947 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3949 if (thread_fsm
!= NULL
)
3950 should_stop
= thread_fsm
->should_stop (thr
);
3959 bool should_notify_stop
= true;
3962 clean_up_just_stopped_threads_fsms (ecs
);
3964 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3965 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3967 if (should_notify_stop
)
3969 /* We may not find an inferior if this was a process exit. */
3970 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3971 proceeded
= normal_stop ();
3976 inferior_event_handler (INF_EXEC_COMPLETE
);
3980 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3981 previously selected thread is gone. We have two
3982 choices - switch to no thread selected, or restore the
3983 previously selected thread (now exited). We chose the
3984 later, just because that's what GDB used to do. After
3985 this, "info threads" says "The current thread <Thread
3986 ID 2> has terminated." instead of "No thread
3990 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3991 restore_thread
.dont_restore ();
3995 defer_delete_threads
.release ();
3996 defer_bpstat_clear
.release ();
3998 /* No error, don't finish the thread states yet. */
3999 finish_state
.release ();
4001 /* This scope is used to ensure that readline callbacks are
4002 reinstalled here. */
4005 /* If a UI was in sync execution mode, and now isn't, restore its
4006 prompt (a synchronous execution command has finished, and we're
4007 ready for input). */
4008 all_uis_check_sync_execution_done ();
4011 && exec_done_display_p
4012 && (inferior_ptid
== null_ptid
4013 || inferior_thread ()->state
!= THREAD_RUNNING
))
4014 printf_unfiltered (_("completed.\n"));
4020 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4021 struct symtab_and_line sal
)
4023 /* This can be removed once this function no longer implicitly relies on the
4024 inferior_ptid value. */
4025 gdb_assert (inferior_ptid
== tp
->ptid
);
4027 tp
->control
.step_frame_id
= get_frame_id (frame
);
4028 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4030 tp
->current_symtab
= sal
.symtab
;
4031 tp
->current_line
= sal
.line
;
4034 /* Clear context switchable stepping state. */
4037 init_thread_stepping_state (struct thread_info
*tss
)
4039 tss
->stepped_breakpoint
= 0;
4040 tss
->stepping_over_breakpoint
= 0;
4041 tss
->stepping_over_watchpoint
= 0;
4042 tss
->step_after_step_resume_breakpoint
= 0;
4048 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4049 target_waitstatus status
)
4051 target_last_proc_target
= target
;
4052 target_last_wait_ptid
= ptid
;
4053 target_last_waitstatus
= status
;
4059 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4060 target_waitstatus
*status
)
4062 if (target
!= nullptr)
4063 *target
= target_last_proc_target
;
4064 if (ptid
!= nullptr)
4065 *ptid
= target_last_wait_ptid
;
4066 if (status
!= nullptr)
4067 *status
= target_last_waitstatus
;
4073 nullify_last_target_wait_ptid (void)
4075 target_last_proc_target
= nullptr;
4076 target_last_wait_ptid
= minus_one_ptid
;
4077 target_last_waitstatus
= {};
4080 /* Switch thread contexts. */
4083 context_switch (execution_control_state
*ecs
)
4085 if (ecs
->ptid
!= inferior_ptid
4086 && (inferior_ptid
== null_ptid
4087 || ecs
->event_thread
!= inferior_thread ()))
4089 infrun_debug_printf ("Switching context from %s to %s",
4090 target_pid_to_str (inferior_ptid
).c_str (),
4091 target_pid_to_str (ecs
->ptid
).c_str ());
4094 switch_to_thread (ecs
->event_thread
);
4097 /* If the target can't tell whether we've hit breakpoints
4098 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4099 check whether that could have been caused by a breakpoint. If so,
4100 adjust the PC, per gdbarch_decr_pc_after_break. */
4103 adjust_pc_after_break (struct thread_info
*thread
,
4104 struct target_waitstatus
*ws
)
4106 struct regcache
*regcache
;
4107 struct gdbarch
*gdbarch
;
4108 CORE_ADDR breakpoint_pc
, decr_pc
;
4110 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4111 we aren't, just return.
4113 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4114 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4115 implemented by software breakpoints should be handled through the normal
4118 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4119 different signals (SIGILL or SIGEMT for instance), but it is less
4120 clear where the PC is pointing afterwards. It may not match
4121 gdbarch_decr_pc_after_break. I don't know any specific target that
4122 generates these signals at breakpoints (the code has been in GDB since at
4123 least 1992) so I can not guess how to handle them here.
4125 In earlier versions of GDB, a target with
4126 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4127 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4128 target with both of these set in GDB history, and it seems unlikely to be
4129 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4131 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4134 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4137 /* In reverse execution, when a breakpoint is hit, the instruction
4138 under it has already been de-executed. The reported PC always
4139 points at the breakpoint address, so adjusting it further would
4140 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4143 B1 0x08000000 : INSN1
4144 B2 0x08000001 : INSN2
4146 PC -> 0x08000003 : INSN4
4148 Say you're stopped at 0x08000003 as above. Reverse continuing
4149 from that point should hit B2 as below. Reading the PC when the
4150 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4151 been de-executed already.
4153 B1 0x08000000 : INSN1
4154 B2 PC -> 0x08000001 : INSN2
4158 We can't apply the same logic as for forward execution, because
4159 we would wrongly adjust the PC to 0x08000000, since there's a
4160 breakpoint at PC - 1. We'd then report a hit on B1, although
4161 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4163 if (execution_direction
== EXEC_REVERSE
)
4166 /* If the target can tell whether the thread hit a SW breakpoint,
4167 trust it. Targets that can tell also adjust the PC
4169 if (target_supports_stopped_by_sw_breakpoint ())
4172 /* Note that relying on whether a breakpoint is planted in memory to
4173 determine this can fail. E.g,. the breakpoint could have been
4174 removed since. Or the thread could have been told to step an
4175 instruction the size of a breakpoint instruction, and only
4176 _after_ was a breakpoint inserted at its address. */
4178 /* If this target does not decrement the PC after breakpoints, then
4179 we have nothing to do. */
4180 regcache
= get_thread_regcache (thread
);
4181 gdbarch
= regcache
->arch ();
4183 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4187 const address_space
*aspace
= regcache
->aspace ();
4189 /* Find the location where (if we've hit a breakpoint) the
4190 breakpoint would be. */
4191 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4193 /* If the target can't tell whether a software breakpoint triggered,
4194 fallback to figuring it out based on breakpoints we think were
4195 inserted in the target, and on whether the thread was stepped or
4198 /* Check whether there actually is a software breakpoint inserted at
4201 If in non-stop mode, a race condition is possible where we've
4202 removed a breakpoint, but stop events for that breakpoint were
4203 already queued and arrive later. To suppress those spurious
4204 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4205 and retire them after a number of stop events are reported. Note
4206 this is an heuristic and can thus get confused. The real fix is
4207 to get the "stopped by SW BP and needs adjustment" info out of
4208 the target/kernel (and thus never reach here; see above). */
4209 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4210 || (target_is_non_stop_p ()
4211 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4213 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4215 if (record_full_is_used ())
4216 restore_operation_disable
.emplace
4217 (record_full_gdb_operation_disable_set ());
4219 /* When using hardware single-step, a SIGTRAP is reported for both
4220 a completed single-step and a software breakpoint. Need to
4221 differentiate between the two, as the latter needs adjusting
4222 but the former does not.
4224 The SIGTRAP can be due to a completed hardware single-step only if
4225 - we didn't insert software single-step breakpoints
4226 - this thread is currently being stepped
4228 If any of these events did not occur, we must have stopped due
4229 to hitting a software breakpoint, and have to back up to the
4232 As a special case, we could have hardware single-stepped a
4233 software breakpoint. In this case (prev_pc == breakpoint_pc),
4234 we also need to back up to the breakpoint address. */
4236 if (thread_has_single_step_breakpoints_set (thread
)
4237 || !currently_stepping (thread
)
4238 || (thread
->stepped_breakpoint
4239 && thread
->prev_pc
== breakpoint_pc
))
4240 regcache_write_pc (regcache
, breakpoint_pc
);
4245 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4247 for (frame
= get_prev_frame (frame
);
4249 frame
= get_prev_frame (frame
))
4251 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4253 if (get_frame_type (frame
) != INLINE_FRAME
)
4260 /* Look for an inline frame that is marked for skip.
4261 If PREV_FRAME is TRUE start at the previous frame,
4262 otherwise start at the current frame. Stop at the
4263 first non-inline frame, or at the frame where the
4267 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4269 struct frame_info
*frame
= get_current_frame ();
4272 frame
= get_prev_frame (frame
);
4274 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4276 const char *fn
= NULL
;
4277 symtab_and_line sal
;
4280 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4282 if (get_frame_type (frame
) != INLINE_FRAME
)
4285 sal
= find_frame_sal (frame
);
4286 sym
= get_frame_function (frame
);
4289 fn
= sym
->print_name ();
4292 && function_name_is_marked_for_skip (fn
, sal
))
4299 /* If the event thread has the stop requested flag set, pretend it
4300 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4304 handle_stop_requested (struct execution_control_state
*ecs
)
4306 if (ecs
->event_thread
->stop_requested
)
4308 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4309 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4310 handle_signal_stop (ecs
);
4316 /* Auxiliary function that handles syscall entry/return events.
4317 It returns 1 if the inferior should keep going (and GDB
4318 should ignore the event), or 0 if the event deserves to be
4322 handle_syscall_event (struct execution_control_state
*ecs
)
4324 struct regcache
*regcache
;
4327 context_switch (ecs
);
4329 regcache
= get_thread_regcache (ecs
->event_thread
);
4330 syscall_number
= ecs
->ws
.value
.syscall_number
;
4331 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4333 if (catch_syscall_enabled () > 0
4334 && catching_syscall_number (syscall_number
) > 0)
4336 infrun_debug_printf ("syscall number=%d", syscall_number
);
4338 ecs
->event_thread
->control
.stop_bpstat
4339 = bpstat_stop_status (regcache
->aspace (),
4340 ecs
->event_thread
->suspend
.stop_pc
,
4341 ecs
->event_thread
, &ecs
->ws
);
4343 if (handle_stop_requested (ecs
))
4346 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4348 /* Catchpoint hit. */
4353 if (handle_stop_requested (ecs
))
4356 /* If no catchpoint triggered for this, then keep going. */
4361 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4364 fill_in_stop_func (struct gdbarch
*gdbarch
,
4365 struct execution_control_state
*ecs
)
4367 if (!ecs
->stop_func_filled_in
)
4370 const general_symbol_info
*gsi
;
4372 /* Don't care about return value; stop_func_start and stop_func_name
4373 will both be 0 if it doesn't work. */
4374 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4376 &ecs
->stop_func_start
,
4377 &ecs
->stop_func_end
,
4379 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4381 /* The call to find_pc_partial_function, above, will set
4382 stop_func_start and stop_func_end to the start and end
4383 of the range containing the stop pc. If this range
4384 contains the entry pc for the block (which is always the
4385 case for contiguous blocks), advance stop_func_start past
4386 the function's start offset and entrypoint. Note that
4387 stop_func_start is NOT advanced when in a range of a
4388 non-contiguous block that does not contain the entry pc. */
4389 if (block
!= nullptr
4390 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4391 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4393 ecs
->stop_func_start
4394 += gdbarch_deprecated_function_start_offset (gdbarch
);
4396 if (gdbarch_skip_entrypoint_p (gdbarch
))
4397 ecs
->stop_func_start
4398 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4401 ecs
->stop_func_filled_in
= 1;
4406 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4408 static enum stop_kind
4409 get_inferior_stop_soon (execution_control_state
*ecs
)
4411 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4413 gdb_assert (inf
!= NULL
);
4414 return inf
->control
.stop_soon
;
4417 /* Poll for one event out of the current target. Store the resulting
4418 waitstatus in WS, and return the event ptid. Does not block. */
4421 poll_one_curr_target (struct target_waitstatus
*ws
)
4425 overlay_cache_invalid
= 1;
4427 /* Flush target cache before starting to handle each event.
4428 Target was running and cache could be stale. This is just a
4429 heuristic. Running threads may modify target memory, but we
4430 don't get any event. */
4431 target_dcache_invalidate ();
4433 if (deprecated_target_wait_hook
)
4434 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4436 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4439 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4444 /* An event reported by wait_one. */
4446 struct wait_one_event
4448 /* The target the event came out of. */
4449 process_stratum_target
*target
;
4451 /* The PTID the event was for. */
4454 /* The waitstatus. */
4455 target_waitstatus ws
;
4458 /* Wait for one event out of any target. */
4460 static wait_one_event
4465 for (inferior
*inf
: all_inferiors ())
4467 process_stratum_target
*target
= inf
->process_target ();
4469 || !target
->is_async_p ()
4470 || !target
->threads_executing
)
4473 switch_to_inferior_no_thread (inf
);
4475 wait_one_event event
;
4476 event
.target
= target
;
4477 event
.ptid
= poll_one_curr_target (&event
.ws
);
4479 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4481 /* If nothing is resumed, remove the target from the
4485 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4489 /* Block waiting for some event. */
4496 for (inferior
*inf
: all_inferiors ())
4498 process_stratum_target
*target
= inf
->process_target ();
4500 || !target
->is_async_p ()
4501 || !target
->threads_executing
)
4504 int fd
= target
->async_wait_fd ();
4505 FD_SET (fd
, &readfds
);
4512 /* No waitable targets left. All must be stopped. */
4513 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4518 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4524 perror_with_name ("interruptible_select");
4529 /* Save the thread's event and stop reason to process it later. */
4532 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4534 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4535 target_waitstatus_to_string (ws
).c_str (),
4540 /* Record for later. */
4541 tp
->suspend
.waitstatus
= *ws
;
4542 tp
->suspend
.waitstatus_pending_p
= 1;
4544 struct regcache
*regcache
= get_thread_regcache (tp
);
4545 const address_space
*aspace
= regcache
->aspace ();
4547 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4548 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4550 CORE_ADDR pc
= regcache_read_pc (regcache
);
4552 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4554 scoped_restore_current_thread restore_thread
;
4555 switch_to_thread (tp
);
4557 if (target_stopped_by_watchpoint ())
4559 tp
->suspend
.stop_reason
4560 = TARGET_STOPPED_BY_WATCHPOINT
;
4562 else if (target_supports_stopped_by_sw_breakpoint ()
4563 && target_stopped_by_sw_breakpoint ())
4565 tp
->suspend
.stop_reason
4566 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4568 else if (target_supports_stopped_by_hw_breakpoint ()
4569 && target_stopped_by_hw_breakpoint ())
4571 tp
->suspend
.stop_reason
4572 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4574 else if (!target_supports_stopped_by_hw_breakpoint ()
4575 && hardware_breakpoint_inserted_here_p (aspace
,
4578 tp
->suspend
.stop_reason
4579 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4581 else if (!target_supports_stopped_by_sw_breakpoint ()
4582 && software_breakpoint_inserted_here_p (aspace
,
4585 tp
->suspend
.stop_reason
4586 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4588 else if (!thread_has_single_step_breakpoints_set (tp
)
4589 && currently_stepping (tp
))
4591 tp
->suspend
.stop_reason
4592 = TARGET_STOPPED_BY_SINGLE_STEP
;
4597 /* Mark the non-executing threads accordingly. In all-stop, all
4598 threads of all processes are stopped when we get any event
4599 reported. In non-stop mode, only the event thread stops. */
4602 mark_non_executing_threads (process_stratum_target
*target
,
4604 struct target_waitstatus ws
)
4608 if (!target_is_non_stop_p ())
4609 mark_ptid
= minus_one_ptid
;
4610 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4611 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4613 /* If we're handling a process exit in non-stop mode, even
4614 though threads haven't been deleted yet, one would think
4615 that there is nothing to do, as threads of the dead process
4616 will be soon deleted, and threads of any other process were
4617 left running. However, on some targets, threads survive a
4618 process exit event. E.g., for the "checkpoint" command,
4619 when the current checkpoint/fork exits, linux-fork.c
4620 automatically switches to another fork from within
4621 target_mourn_inferior, by associating the same
4622 inferior/thread to another fork. We haven't mourned yet at
4623 this point, but we must mark any threads left in the
4624 process as not-executing so that finish_thread_state marks
4625 them stopped (in the user's perspective) if/when we present
4626 the stop to the user. */
4627 mark_ptid
= ptid_t (event_ptid
.pid ());
4630 mark_ptid
= event_ptid
;
4632 set_executing (target
, mark_ptid
, false);
4634 /* Likewise the resumed flag. */
4635 set_resumed (target
, mark_ptid
, false);
4641 stop_all_threads (void)
4643 /* We may need multiple passes to discover all threads. */
4647 gdb_assert (exists_non_stop_target ());
4649 infrun_debug_printf ("starting");
4651 scoped_restore_current_thread restore_thread
;
4653 /* Enable 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 (true);
4662 /* Disable thread events of all targets. */
4663 for (auto *target
: all_non_exited_process_targets ())
4665 switch_to_target_no_thread (target
);
4666 target_thread_events (false);
4669 /* Use infrun_debug_printf_1 directly to get a meaningful function
4672 infrun_debug_printf_1 ("stop_all_threads", "done");
4675 /* Request threads to stop, and then wait for the stops. Because
4676 threads we already know about can spawn more threads while we're
4677 trying to stop them, and we only learn about new threads when we
4678 update the thread list, do this in a loop, and keep iterating
4679 until two passes find no threads that need to be stopped. */
4680 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4682 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4685 int waits_needed
= 0;
4687 for (auto *target
: all_non_exited_process_targets ())
4689 switch_to_target_no_thread (target
);
4690 update_thread_list ();
4693 /* Go through all threads looking for threads that we need
4694 to tell the target to stop. */
4695 for (thread_info
*t
: all_non_exited_threads ())
4697 /* For a single-target setting with an all-stop target,
4698 we would not even arrive here. For a multi-target
4699 setting, until GDB is able to handle a mixture of
4700 all-stop and non-stop targets, simply skip all-stop
4701 targets' threads. This should be fine due to the
4702 protection of 'check_multi_target_resumption'. */
4704 switch_to_thread_no_regs (t
);
4705 if (!target_is_non_stop_p ())
4710 /* If already stopping, don't request a stop again.
4711 We just haven't seen the notification yet. */
4712 if (!t
->stop_requested
)
4714 infrun_debug_printf (" %s executing, need stop",
4715 target_pid_to_str (t
->ptid
).c_str ());
4716 target_stop (t
->ptid
);
4717 t
->stop_requested
= 1;
4721 infrun_debug_printf (" %s executing, already stopping",
4722 target_pid_to_str (t
->ptid
).c_str ());
4725 if (t
->stop_requested
)
4730 infrun_debug_printf (" %s not executing",
4731 target_pid_to_str (t
->ptid
).c_str ());
4733 /* The thread may be not executing, but still be
4734 resumed with a pending status to process. */
4739 if (waits_needed
== 0)
4742 /* If we find new threads on the second iteration, restart
4743 over. We want to see two iterations in a row with all
4748 for (int i
= 0; i
< waits_needed
; i
++)
4750 wait_one_event event
= wait_one ();
4753 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4754 target_pid_to_str (event
.ptid
).c_str ());
4756 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4758 /* All resumed threads exited. */
4761 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4762 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4763 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4765 /* One thread/process exited/signalled. */
4767 thread_info
*t
= nullptr;
4769 /* The target may have reported just a pid. If so, try
4770 the first non-exited thread. */
4771 if (event
.ptid
.is_pid ())
4773 int pid
= event
.ptid
.pid ();
4774 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4775 for (thread_info
*tp
: inf
->non_exited_threads ())
4781 /* If there is no available thread, the event would
4782 have to be appended to a per-inferior event list,
4783 which does not exist (and if it did, we'd have
4784 to adjust run control command to be able to
4785 resume such an inferior). We assert here instead
4786 of going into an infinite loop. */
4787 gdb_assert (t
!= nullptr);
4790 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4794 t
= find_thread_ptid (event
.target
, event
.ptid
);
4795 /* Check if this is the first time we see this thread.
4796 Don't bother adding if it individually exited. */
4798 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4799 t
= add_thread (event
.target
, event
.ptid
);
4804 /* Set the threads as non-executing to avoid
4805 another stop attempt on them. */
4806 switch_to_thread_no_regs (t
);
4807 mark_non_executing_threads (event
.target
, event
.ptid
,
4809 save_waitstatus (t
, &event
.ws
);
4810 t
->stop_requested
= false;
4815 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4817 t
= add_thread (event
.target
, event
.ptid
);
4819 t
->stop_requested
= 0;
4822 t
->control
.may_range_step
= 0;
4824 /* This may be the first time we see the inferior report
4826 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4827 if (inf
->needs_setup
)
4829 switch_to_thread_no_regs (t
);
4833 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4834 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4836 /* We caught the event that we intended to catch, so
4837 there's no event pending. */
4838 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4839 t
->suspend
.waitstatus_pending_p
= 0;
4841 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4843 /* Add it back to the step-over queue. */
4845 ("displaced-step of %s canceled: adding back to "
4846 "the step-over queue",
4847 target_pid_to_str (t
->ptid
).c_str ());
4849 t
->control
.trap_expected
= 0;
4850 thread_step_over_chain_enqueue (t
);
4855 enum gdb_signal sig
;
4856 struct regcache
*regcache
;
4859 ("target_wait %s, saving status for %d.%ld.%ld",
4860 target_waitstatus_to_string (&event
.ws
).c_str (),
4861 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4863 /* Record for later. */
4864 save_waitstatus (t
, &event
.ws
);
4866 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4867 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4869 if (displaced_step_fixup (t
, sig
) < 0)
4871 /* Add it back to the step-over queue. */
4872 t
->control
.trap_expected
= 0;
4873 thread_step_over_chain_enqueue (t
);
4876 regcache
= get_thread_regcache (t
);
4877 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4879 infrun_debug_printf ("saved stop_pc=%s for %s "
4880 "(currently_stepping=%d)",
4881 paddress (target_gdbarch (),
4882 t
->suspend
.stop_pc
),
4883 target_pid_to_str (t
->ptid
).c_str (),
4884 currently_stepping (t
));
4892 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4895 handle_no_resumed (struct execution_control_state
*ecs
)
4897 if (target_can_async_p ())
4901 for (ui
*ui
: all_uis ())
4903 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4911 /* There were no unwaited-for children left in the target, but,
4912 we're not synchronously waiting for events either. Just
4915 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4916 prepare_to_wait (ecs
);
4921 /* Otherwise, if we were running a synchronous execution command, we
4922 may need to cancel it and give the user back the terminal.
4924 In non-stop mode, the target can't tell whether we've already
4925 consumed previous stop events, so it can end up sending us a
4926 no-resumed event like so:
4928 #0 - thread 1 is left stopped
4930 #1 - thread 2 is resumed and hits breakpoint
4931 -> TARGET_WAITKIND_STOPPED
4933 #2 - thread 3 is resumed and exits
4934 this is the last resumed thread, so
4935 -> TARGET_WAITKIND_NO_RESUMED
4937 #3 - gdb processes stop for thread 2 and decides to re-resume
4940 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4941 thread 2 is now resumed, so the event should be ignored.
4943 IOW, if the stop for thread 2 doesn't end a foreground command,
4944 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4945 event. But it could be that the event meant that thread 2 itself
4946 (or whatever other thread was the last resumed thread) exited.
4948 To address this we refresh the thread list and check whether we
4949 have resumed threads _now_. In the example above, this removes
4950 thread 3 from the thread list. If thread 2 was re-resumed, we
4951 ignore this event. If we find no thread resumed, then we cancel
4952 the synchronous command and show "no unwaited-for " to the
4955 inferior
*curr_inf
= current_inferior ();
4957 scoped_restore_current_thread restore_thread
;
4959 for (auto *target
: all_non_exited_process_targets ())
4961 switch_to_target_no_thread (target
);
4962 update_thread_list ();
4967 - the current target has no thread executing, and
4968 - the current inferior is native, and
4969 - the current inferior is the one which has the terminal, and
4972 then a Ctrl-C from this point on would remain stuck in the
4973 kernel, until a thread resumes and dequeues it. That would
4974 result in the GDB CLI not reacting to Ctrl-C, not able to
4975 interrupt the program. To address this, if the current inferior
4976 no longer has any thread executing, we give the terminal to some
4977 other inferior that has at least one thread executing. */
4978 bool swap_terminal
= true;
4980 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4981 whether to report it to the user. */
4982 bool ignore_event
= false;
4984 for (thread_info
*thread
: all_non_exited_threads ())
4986 if (swap_terminal
&& thread
->executing
)
4988 if (thread
->inf
!= curr_inf
)
4990 target_terminal::ours ();
4992 switch_to_thread (thread
);
4993 target_terminal::inferior ();
4995 swap_terminal
= false;
4999 && (thread
->executing
5000 || thread
->suspend
.waitstatus_pending_p
))
5002 /* Either there were no unwaited-for children left in the
5003 target at some point, but there are now, or some target
5004 other than the eventing one has unwaited-for children
5005 left. Just ignore. */
5006 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
5007 "(ignoring: found resumed)");
5009 ignore_event
= true;
5012 if (ignore_event
&& !swap_terminal
)
5018 switch_to_inferior_no_thread (curr_inf
);
5019 prepare_to_wait (ecs
);
5023 /* Go ahead and report the event. */
5027 /* Given an execution control state that has been freshly filled in by
5028 an event from the inferior, figure out what it means and take
5031 The alternatives are:
5033 1) stop_waiting and return; to really stop and return to the
5036 2) keep_going and return; to wait for the next event (set
5037 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5041 handle_inferior_event (struct execution_control_state
*ecs
)
5043 /* Make sure that all temporary struct value objects that were
5044 created during the handling of the event get deleted at the
5046 scoped_value_mark free_values
;
5048 enum stop_kind stop_soon
;
5050 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5052 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5054 /* We had an event in the inferior, but we are not interested in
5055 handling it at this level. The lower layers have already
5056 done what needs to be done, if anything.
5058 One of the possible circumstances for this is when the
5059 inferior produces output for the console. The inferior has
5060 not stopped, and we are ignoring the event. Another possible
5061 circumstance is any event which the lower level knows will be
5062 reported multiple times without an intervening resume. */
5063 prepare_to_wait (ecs
);
5067 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5069 prepare_to_wait (ecs
);
5073 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5074 && handle_no_resumed (ecs
))
5077 /* Cache the last target/ptid/waitstatus. */
5078 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5080 /* Always clear state belonging to the previous time we stopped. */
5081 stop_stack_dummy
= STOP_NONE
;
5083 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5085 /* No unwaited-for children left. IOW, all resumed children
5087 stop_print_frame
= 0;
5092 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5093 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5095 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5096 /* If it's a new thread, add it to the thread database. */
5097 if (ecs
->event_thread
== NULL
)
5098 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5100 /* Disable range stepping. If the next step request could use a
5101 range, this will be end up re-enabled then. */
5102 ecs
->event_thread
->control
.may_range_step
= 0;
5105 /* Dependent on valid ECS->EVENT_THREAD. */
5106 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5108 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5109 reinit_frame_cache ();
5111 breakpoint_retire_moribund ();
5113 /* First, distinguish signals caused by the debugger from signals
5114 that have to do with the program's own actions. Note that
5115 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5116 on the operating system version. Here we detect when a SIGILL or
5117 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5118 something similar for SIGSEGV, since a SIGSEGV will be generated
5119 when we're trying to execute a breakpoint instruction on a
5120 non-executable stack. This happens for call dummy breakpoints
5121 for architectures like SPARC that place call dummies on the
5123 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5124 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5125 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5126 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5128 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5130 if (breakpoint_inserted_here_p (regcache
->aspace (),
5131 regcache_read_pc (regcache
)))
5133 infrun_debug_printf ("Treating signal as SIGTRAP");
5134 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5138 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5140 switch (ecs
->ws
.kind
)
5142 case TARGET_WAITKIND_LOADED
:
5143 context_switch (ecs
);
5144 /* Ignore gracefully during startup of the inferior, as it might
5145 be the shell which has just loaded some objects, otherwise
5146 add the symbols for the newly loaded objects. Also ignore at
5147 the beginning of an attach or remote session; we will query
5148 the full list of libraries once the connection is
5151 stop_soon
= get_inferior_stop_soon (ecs
);
5152 if (stop_soon
== NO_STOP_QUIETLY
)
5154 struct regcache
*regcache
;
5156 regcache
= get_thread_regcache (ecs
->event_thread
);
5158 handle_solib_event ();
5160 ecs
->event_thread
->control
.stop_bpstat
5161 = bpstat_stop_status (regcache
->aspace (),
5162 ecs
->event_thread
->suspend
.stop_pc
,
5163 ecs
->event_thread
, &ecs
->ws
);
5165 if (handle_stop_requested (ecs
))
5168 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5170 /* A catchpoint triggered. */
5171 process_event_stop_test (ecs
);
5175 /* If requested, stop when the dynamic linker notifies
5176 gdb of events. This allows the user to get control
5177 and place breakpoints in initializer routines for
5178 dynamically loaded objects (among other things). */
5179 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5180 if (stop_on_solib_events
)
5182 /* Make sure we print "Stopped due to solib-event" in
5184 stop_print_frame
= 1;
5191 /* If we are skipping through a shell, or through shared library
5192 loading that we aren't interested in, resume the program. If
5193 we're running the program normally, also resume. */
5194 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5196 /* Loading of shared libraries might have changed breakpoint
5197 addresses. Make sure new breakpoints are inserted. */
5198 if (stop_soon
== NO_STOP_QUIETLY
)
5199 insert_breakpoints ();
5200 resume (GDB_SIGNAL_0
);
5201 prepare_to_wait (ecs
);
5205 /* But stop if we're attaching or setting up a remote
5207 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5208 || stop_soon
== STOP_QUIETLY_REMOTE
)
5210 infrun_debug_printf ("quietly stopped");
5215 internal_error (__FILE__
, __LINE__
,
5216 _("unhandled stop_soon: %d"), (int) stop_soon
);
5218 case TARGET_WAITKIND_SPURIOUS
:
5219 if (handle_stop_requested (ecs
))
5221 context_switch (ecs
);
5222 resume (GDB_SIGNAL_0
);
5223 prepare_to_wait (ecs
);
5226 case TARGET_WAITKIND_THREAD_CREATED
:
5227 if (handle_stop_requested (ecs
))
5229 context_switch (ecs
);
5230 if (!switch_back_to_stepped_thread (ecs
))
5234 case TARGET_WAITKIND_EXITED
:
5235 case TARGET_WAITKIND_SIGNALLED
:
5237 /* Depending on the system, ecs->ptid may point to a thread or
5238 to a process. On some targets, target_mourn_inferior may
5239 need to have access to the just-exited thread. That is the
5240 case of GNU/Linux's "checkpoint" support, for example.
5241 Call the switch_to_xxx routine as appropriate. */
5242 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5244 switch_to_thread (thr
);
5247 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5248 switch_to_inferior_no_thread (inf
);
5251 handle_vfork_child_exec_or_exit (0);
5252 target_terminal::ours (); /* Must do this before mourn anyway. */
5254 /* Clearing any previous state of convenience variables. */
5255 clear_exit_convenience_vars ();
5257 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5259 /* Record the exit code in the convenience variable $_exitcode, so
5260 that the user can inspect this again later. */
5261 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5262 (LONGEST
) ecs
->ws
.value
.integer
);
5264 /* Also record this in the inferior itself. */
5265 current_inferior ()->has_exit_code
= 1;
5266 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5268 /* Support the --return-child-result option. */
5269 return_child_result_value
= ecs
->ws
.value
.integer
;
5271 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5275 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5277 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5279 /* Set the value of the internal variable $_exitsignal,
5280 which holds the signal uncaught by the inferior. */
5281 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5282 gdbarch_gdb_signal_to_target (gdbarch
,
5283 ecs
->ws
.value
.sig
));
5287 /* We don't have access to the target's method used for
5288 converting between signal numbers (GDB's internal
5289 representation <-> target's representation).
5290 Therefore, we cannot do a good job at displaying this
5291 information to the user. It's better to just warn
5292 her about it (if infrun debugging is enabled), and
5294 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5298 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5301 gdb_flush (gdb_stdout
);
5302 target_mourn_inferior (inferior_ptid
);
5303 stop_print_frame
= 0;
5307 case TARGET_WAITKIND_FORKED
:
5308 case TARGET_WAITKIND_VFORKED
:
5309 /* Check whether the inferior is displaced stepping. */
5311 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5312 struct gdbarch
*gdbarch
= regcache
->arch ();
5314 /* If checking displaced stepping is supported, and thread
5315 ecs->ptid is displaced stepping. */
5316 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5318 struct inferior
*parent_inf
5319 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5320 struct regcache
*child_regcache
;
5321 CORE_ADDR parent_pc
;
5323 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5325 struct displaced_step_inferior_state
*displaced
5326 = get_displaced_stepping_state (parent_inf
);
5328 /* Restore scratch pad for child process. */
5329 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5332 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5333 indicating that the displaced stepping of syscall instruction
5334 has been done. Perform cleanup for parent process here. Note
5335 that this operation also cleans up the child process for vfork,
5336 because their pages are shared. */
5337 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5338 /* Start a new step-over in another thread if there's one
5342 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5343 the child's PC is also within the scratchpad. Set the child's PC
5344 to the parent's PC value, which has already been fixed up.
5345 FIXME: we use the parent's aspace here, although we're touching
5346 the child, because the child hasn't been added to the inferior
5347 list yet at this point. */
5350 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5351 ecs
->ws
.value
.related_pid
,
5353 parent_inf
->aspace
);
5354 /* Read PC value of parent process. */
5355 parent_pc
= regcache_read_pc (regcache
);
5357 if (debug_displaced
)
5358 fprintf_unfiltered (gdb_stdlog
,
5359 "displaced: write child pc from %s to %s\n",
5361 regcache_read_pc (child_regcache
)),
5362 paddress (gdbarch
, parent_pc
));
5364 regcache_write_pc (child_regcache
, parent_pc
);
5368 context_switch (ecs
);
5370 /* Immediately detach breakpoints from the child before there's
5371 any chance of letting the user delete breakpoints from the
5372 breakpoint lists. If we don't do this early, it's easy to
5373 leave left over traps in the child, vis: "break foo; catch
5374 fork; c; <fork>; del; c; <child calls foo>". We only follow
5375 the fork on the last `continue', and by that time the
5376 breakpoint at "foo" is long gone from the breakpoint table.
5377 If we vforked, then we don't need to unpatch here, since both
5378 parent and child are sharing the same memory pages; we'll
5379 need to unpatch at follow/detach time instead to be certain
5380 that new breakpoints added between catchpoint hit time and
5381 vfork follow are detached. */
5382 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5384 /* This won't actually modify the breakpoint list, but will
5385 physically remove the breakpoints from the child. */
5386 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5389 delete_just_stopped_threads_single_step_breakpoints ();
5391 /* In case the event is caught by a catchpoint, remember that
5392 the event is to be followed at the next resume of the thread,
5393 and not immediately. */
5394 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5396 ecs
->event_thread
->suspend
.stop_pc
5397 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5399 ecs
->event_thread
->control
.stop_bpstat
5400 = bpstat_stop_status (get_current_regcache ()->aspace (),
5401 ecs
->event_thread
->suspend
.stop_pc
,
5402 ecs
->event_thread
, &ecs
->ws
);
5404 if (handle_stop_requested (ecs
))
5407 /* If no catchpoint triggered for this, then keep going. Note
5408 that we're interested in knowing the bpstat actually causes a
5409 stop, not just if it may explain the signal. Software
5410 watchpoints, for example, always appear in the bpstat. */
5411 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5414 = (follow_fork_mode_string
== follow_fork_mode_child
);
5416 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5418 process_stratum_target
*targ
5419 = ecs
->event_thread
->inf
->process_target ();
5421 bool should_resume
= follow_fork ();
5423 /* Note that one of these may be an invalid pointer,
5424 depending on detach_fork. */
5425 thread_info
*parent
= ecs
->event_thread
;
5427 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5429 /* At this point, the parent is marked running, and the
5430 child is marked stopped. */
5432 /* If not resuming the parent, mark it stopped. */
5433 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5434 parent
->set_running (false);
5436 /* If resuming the child, mark it running. */
5437 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5438 child
->set_running (true);
5440 /* In non-stop mode, also resume the other branch. */
5441 if (!detach_fork
&& (non_stop
5442 || (sched_multi
&& target_is_non_stop_p ())))
5445 switch_to_thread (parent
);
5447 switch_to_thread (child
);
5449 ecs
->event_thread
= inferior_thread ();
5450 ecs
->ptid
= inferior_ptid
;
5455 switch_to_thread (child
);
5457 switch_to_thread (parent
);
5459 ecs
->event_thread
= inferior_thread ();
5460 ecs
->ptid
= inferior_ptid
;
5468 process_event_stop_test (ecs
);
5471 case TARGET_WAITKIND_VFORK_DONE
:
5472 /* Done with the shared memory region. Re-insert breakpoints in
5473 the parent, and keep going. */
5475 context_switch (ecs
);
5477 current_inferior ()->waiting_for_vfork_done
= 0;
5478 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5480 if (handle_stop_requested (ecs
))
5483 /* This also takes care of reinserting breakpoints in the
5484 previously locked inferior. */
5488 case TARGET_WAITKIND_EXECD
:
5490 /* Note we can't read registers yet (the stop_pc), because we
5491 don't yet know the inferior's post-exec architecture.
5492 'stop_pc' is explicitly read below instead. */
5493 switch_to_thread_no_regs (ecs
->event_thread
);
5495 /* Do whatever is necessary to the parent branch of the vfork. */
5496 handle_vfork_child_exec_or_exit (1);
5498 /* This causes the eventpoints and symbol table to be reset.
5499 Must do this now, before trying to determine whether to
5501 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5503 /* In follow_exec we may have deleted the original thread and
5504 created a new one. Make sure that the event thread is the
5505 execd thread for that case (this is a nop otherwise). */
5506 ecs
->event_thread
= inferior_thread ();
5508 ecs
->event_thread
->suspend
.stop_pc
5509 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5511 ecs
->event_thread
->control
.stop_bpstat
5512 = bpstat_stop_status (get_current_regcache ()->aspace (),
5513 ecs
->event_thread
->suspend
.stop_pc
,
5514 ecs
->event_thread
, &ecs
->ws
);
5516 /* Note that this may be referenced from inside
5517 bpstat_stop_status above, through inferior_has_execd. */
5518 xfree (ecs
->ws
.value
.execd_pathname
);
5519 ecs
->ws
.value
.execd_pathname
= NULL
;
5521 if (handle_stop_requested (ecs
))
5524 /* If no catchpoint triggered for this, then keep going. */
5525 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5527 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5531 process_event_stop_test (ecs
);
5534 /* Be careful not to try to gather much state about a thread
5535 that's in a syscall. It's frequently a losing proposition. */
5536 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5537 /* Getting the current syscall number. */
5538 if (handle_syscall_event (ecs
) == 0)
5539 process_event_stop_test (ecs
);
5542 /* Before examining the threads further, step this thread to
5543 get it entirely out of the syscall. (We get notice of the
5544 event when the thread is just on the verge of exiting a
5545 syscall. Stepping one instruction seems to get it back
5547 case TARGET_WAITKIND_SYSCALL_RETURN
:
5548 if (handle_syscall_event (ecs
) == 0)
5549 process_event_stop_test (ecs
);
5552 case TARGET_WAITKIND_STOPPED
:
5553 handle_signal_stop (ecs
);
5556 case TARGET_WAITKIND_NO_HISTORY
:
5557 /* Reverse execution: target ran out of history info. */
5559 /* Switch to the stopped thread. */
5560 context_switch (ecs
);
5561 infrun_debug_printf ("stopped");
5563 delete_just_stopped_threads_single_step_breakpoints ();
5564 ecs
->event_thread
->suspend
.stop_pc
5565 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5567 if (handle_stop_requested (ecs
))
5570 gdb::observers::no_history
.notify ();
5576 /* Restart threads back to what they were trying to do back when we
5577 paused them for an in-line step-over. The EVENT_THREAD thread is
5581 restart_threads (struct thread_info
*event_thread
)
5583 /* In case the instruction just stepped spawned a new thread. */
5584 update_thread_list ();
5586 for (thread_info
*tp
: all_non_exited_threads ())
5588 switch_to_thread_no_regs (tp
);
5590 if (tp
== event_thread
)
5592 infrun_debug_printf ("restart threads: [%s] is event thread",
5593 target_pid_to_str (tp
->ptid
).c_str ());
5597 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5599 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5600 target_pid_to_str (tp
->ptid
).c_str ());
5606 infrun_debug_printf ("restart threads: [%s] resumed",
5607 target_pid_to_str (tp
->ptid
).c_str ());
5608 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5612 if (thread_is_in_step_over_chain (tp
))
5614 infrun_debug_printf ("restart threads: [%s] needs step-over",
5615 target_pid_to_str (tp
->ptid
).c_str ());
5616 gdb_assert (!tp
->resumed
);
5621 if (tp
->suspend
.waitstatus_pending_p
)
5623 infrun_debug_printf ("restart threads: [%s] has pending status",
5624 target_pid_to_str (tp
->ptid
).c_str ());
5629 gdb_assert (!tp
->stop_requested
);
5631 /* If some thread needs to start a step-over at this point, it
5632 should still be in the step-over queue, and thus skipped
5634 if (thread_still_needs_step_over (tp
))
5636 internal_error (__FILE__
, __LINE__
,
5637 "thread [%s] needs a step-over, but not in "
5638 "step-over queue\n",
5639 target_pid_to_str (tp
->ptid
).c_str ());
5642 if (currently_stepping (tp
))
5644 infrun_debug_printf ("restart threads: [%s] was stepping",
5645 target_pid_to_str (tp
->ptid
).c_str ());
5646 keep_going_stepped_thread (tp
);
5650 struct execution_control_state ecss
;
5651 struct execution_control_state
*ecs
= &ecss
;
5653 infrun_debug_printf ("restart threads: [%s] continuing",
5654 target_pid_to_str (tp
->ptid
).c_str ());
5655 reset_ecs (ecs
, tp
);
5656 switch_to_thread (tp
);
5657 keep_going_pass_signal (ecs
);
5662 /* Callback for iterate_over_threads. Find a resumed thread that has
5663 a pending waitstatus. */
5666 resumed_thread_with_pending_status (struct thread_info
*tp
,
5670 && tp
->suspend
.waitstatus_pending_p
);
5673 /* Called when we get an event that may finish an in-line or
5674 out-of-line (displaced stepping) step-over started previously.
5675 Return true if the event is processed and we should go back to the
5676 event loop; false if the caller should continue processing the
5680 finish_step_over (struct execution_control_state
*ecs
)
5682 int had_step_over_info
;
5684 displaced_step_fixup (ecs
->event_thread
,
5685 ecs
->event_thread
->suspend
.stop_signal
);
5687 had_step_over_info
= step_over_info_valid_p ();
5689 if (had_step_over_info
)
5691 /* If we're stepping over a breakpoint with all threads locked,
5692 then only the thread that was stepped should be reporting
5694 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5696 clear_step_over_info ();
5699 if (!target_is_non_stop_p ())
5702 /* Start a new step-over in another thread if there's one that
5706 /* If we were stepping over a breakpoint before, and haven't started
5707 a new in-line step-over sequence, then restart all other threads
5708 (except the event thread). We can't do this in all-stop, as then
5709 e.g., we wouldn't be able to issue any other remote packet until
5710 these other threads stop. */
5711 if (had_step_over_info
&& !step_over_info_valid_p ())
5713 struct thread_info
*pending
;
5715 /* If we only have threads with pending statuses, the restart
5716 below won't restart any thread and so nothing re-inserts the
5717 breakpoint we just stepped over. But we need it inserted
5718 when we later process the pending events, otherwise if
5719 another thread has a pending event for this breakpoint too,
5720 we'd discard its event (because the breakpoint that
5721 originally caused the event was no longer inserted). */
5722 context_switch (ecs
);
5723 insert_breakpoints ();
5725 restart_threads (ecs
->event_thread
);
5727 /* If we have events pending, go through handle_inferior_event
5728 again, picking up a pending event at random. This avoids
5729 thread starvation. */
5731 /* But not if we just stepped over a watchpoint in order to let
5732 the instruction execute so we can evaluate its expression.
5733 The set of watchpoints that triggered is recorded in the
5734 breakpoint objects themselves (see bp->watchpoint_triggered).
5735 If we processed another event first, that other event could
5736 clobber this info. */
5737 if (ecs
->event_thread
->stepping_over_watchpoint
)
5740 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5742 if (pending
!= NULL
)
5744 struct thread_info
*tp
= ecs
->event_thread
;
5745 struct regcache
*regcache
;
5747 infrun_debug_printf ("found resumed threads with "
5748 "pending events, saving status");
5750 gdb_assert (pending
!= tp
);
5752 /* Record the event thread's event for later. */
5753 save_waitstatus (tp
, &ecs
->ws
);
5754 /* This was cleared early, by handle_inferior_event. Set it
5755 so this pending event is considered by
5759 gdb_assert (!tp
->executing
);
5761 regcache
= get_thread_regcache (tp
);
5762 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5764 infrun_debug_printf ("saved stop_pc=%s for %s "
5765 "(currently_stepping=%d)",
5766 paddress (target_gdbarch (),
5767 tp
->suspend
.stop_pc
),
5768 target_pid_to_str (tp
->ptid
).c_str (),
5769 currently_stepping (tp
));
5771 /* This in-line step-over finished; clear this so we won't
5772 start a new one. This is what handle_signal_stop would
5773 do, if we returned false. */
5774 tp
->stepping_over_breakpoint
= 0;
5776 /* Wake up the event loop again. */
5777 mark_async_event_handler (infrun_async_inferior_event_token
);
5779 prepare_to_wait (ecs
);
5787 /* Come here when the program has stopped with a signal. */
5790 handle_signal_stop (struct execution_control_state
*ecs
)
5792 struct frame_info
*frame
;
5793 struct gdbarch
*gdbarch
;
5794 int stopped_by_watchpoint
;
5795 enum stop_kind stop_soon
;
5798 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5800 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5802 /* Do we need to clean up the state of a thread that has
5803 completed a displaced single-step? (Doing so usually affects
5804 the PC, so do it here, before we set stop_pc.) */
5805 if (finish_step_over (ecs
))
5808 /* If we either finished a single-step or hit a breakpoint, but
5809 the user wanted this thread to be stopped, pretend we got a
5810 SIG0 (generic unsignaled stop). */
5811 if (ecs
->event_thread
->stop_requested
5812 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5813 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5815 ecs
->event_thread
->suspend
.stop_pc
5816 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5820 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5821 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5823 switch_to_thread (ecs
->event_thread
);
5825 infrun_debug_printf ("stop_pc=%s",
5826 paddress (reg_gdbarch
,
5827 ecs
->event_thread
->suspend
.stop_pc
));
5828 if (target_stopped_by_watchpoint ())
5832 infrun_debug_printf ("stopped by watchpoint");
5834 if (target_stopped_data_address (current_top_target (), &addr
))
5835 infrun_debug_printf ("stopped data address=%s",
5836 paddress (reg_gdbarch
, addr
));
5838 infrun_debug_printf ("(no data address available)");
5842 /* This is originated from start_remote(), start_inferior() and
5843 shared libraries hook functions. */
5844 stop_soon
= get_inferior_stop_soon (ecs
);
5845 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5847 context_switch (ecs
);
5848 infrun_debug_printf ("quietly stopped");
5849 stop_print_frame
= 1;
5854 /* This originates from attach_command(). We need to overwrite
5855 the stop_signal here, because some kernels don't ignore a
5856 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5857 See more comments in inferior.h. On the other hand, if we
5858 get a non-SIGSTOP, report it to the user - assume the backend
5859 will handle the SIGSTOP if it should show up later.
5861 Also consider that the attach is complete when we see a
5862 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5863 target extended-remote report it instead of a SIGSTOP
5864 (e.g. gdbserver). We already rely on SIGTRAP being our
5865 signal, so this is no exception.
5867 Also consider that the attach is complete when we see a
5868 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5869 the target to stop all threads of the inferior, in case the
5870 low level attach operation doesn't stop them implicitly. If
5871 they weren't stopped implicitly, then the stub will report a
5872 GDB_SIGNAL_0, meaning: stopped for no particular reason
5873 other than GDB's request. */
5874 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5875 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5876 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5877 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5879 stop_print_frame
= 1;
5881 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5885 /* See if something interesting happened to the non-current thread. If
5886 so, then switch to that thread. */
5887 if (ecs
->ptid
!= inferior_ptid
)
5889 infrun_debug_printf ("context switch");
5891 context_switch (ecs
);
5893 if (deprecated_context_hook
)
5894 deprecated_context_hook (ecs
->event_thread
->global_num
);
5897 /* At this point, get hold of the now-current thread's frame. */
5898 frame
= get_current_frame ();
5899 gdbarch
= get_frame_arch (frame
);
5901 /* Pull the single step breakpoints out of the target. */
5902 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5904 struct regcache
*regcache
;
5907 regcache
= get_thread_regcache (ecs
->event_thread
);
5908 const address_space
*aspace
= regcache
->aspace ();
5910 pc
= regcache_read_pc (regcache
);
5912 /* However, before doing so, if this single-step breakpoint was
5913 actually for another thread, set this thread up for moving
5915 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5918 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5920 infrun_debug_printf ("[%s] hit another thread's single-step "
5922 target_pid_to_str (ecs
->ptid
).c_str ());
5923 ecs
->hit_singlestep_breakpoint
= 1;
5928 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5929 target_pid_to_str (ecs
->ptid
).c_str ());
5932 delete_just_stopped_threads_single_step_breakpoints ();
5934 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5935 && ecs
->event_thread
->control
.trap_expected
5936 && ecs
->event_thread
->stepping_over_watchpoint
)
5937 stopped_by_watchpoint
= 0;
5939 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5941 /* If necessary, step over this watchpoint. We'll be back to display
5943 if (stopped_by_watchpoint
5944 && (target_have_steppable_watchpoint ()
5945 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5947 /* At this point, we are stopped at an instruction which has
5948 attempted to write to a piece of memory under control of
5949 a watchpoint. The instruction hasn't actually executed
5950 yet. If we were to evaluate the watchpoint expression
5951 now, we would get the old value, and therefore no change
5952 would seem to have occurred.
5954 In order to make watchpoints work `right', we really need
5955 to complete the memory write, and then evaluate the
5956 watchpoint expression. We do this by single-stepping the
5959 It may not be necessary to disable the watchpoint to step over
5960 it. For example, the PA can (with some kernel cooperation)
5961 single step over a watchpoint without disabling the watchpoint.
5963 It is far more common to need to disable a watchpoint to step
5964 the inferior over it. If we have non-steppable watchpoints,
5965 we must disable the current watchpoint; it's simplest to
5966 disable all watchpoints.
5968 Any breakpoint at PC must also be stepped over -- if there's
5969 one, it will have already triggered before the watchpoint
5970 triggered, and we either already reported it to the user, or
5971 it didn't cause a stop and we called keep_going. In either
5972 case, if there was a breakpoint at PC, we must be trying to
5974 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5979 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5980 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5981 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5982 ecs
->event_thread
->control
.stop_step
= 0;
5983 stop_print_frame
= 1;
5984 stopped_by_random_signal
= 0;
5985 bpstat stop_chain
= NULL
;
5987 /* Hide inlined functions starting here, unless we just performed stepi or
5988 nexti. After stepi and nexti, always show the innermost frame (not any
5989 inline function call sites). */
5990 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5992 const address_space
*aspace
5993 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5995 /* skip_inline_frames is expensive, so we avoid it if we can
5996 determine that the address is one where functions cannot have
5997 been inlined. This improves performance with inferiors that
5998 load a lot of shared libraries, because the solib event
5999 breakpoint is defined as the address of a function (i.e. not
6000 inline). Note that we have to check the previous PC as well
6001 as the current one to catch cases when we have just
6002 single-stepped off a breakpoint prior to reinstating it.
6003 Note that we're assuming that the code we single-step to is
6004 not inline, but that's not definitive: there's nothing
6005 preventing the event breakpoint function from containing
6006 inlined code, and the single-step ending up there. If the
6007 user had set a breakpoint on that inlined code, the missing
6008 skip_inline_frames call would break things. Fortunately
6009 that's an extremely unlikely scenario. */
6010 if (!pc_at_non_inline_function (aspace
,
6011 ecs
->event_thread
->suspend
.stop_pc
,
6013 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6014 && ecs
->event_thread
->control
.trap_expected
6015 && pc_at_non_inline_function (aspace
,
6016 ecs
->event_thread
->prev_pc
,
6019 stop_chain
= build_bpstat_chain (aspace
,
6020 ecs
->event_thread
->suspend
.stop_pc
,
6022 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6024 /* Re-fetch current thread's frame in case that invalidated
6026 frame
= get_current_frame ();
6027 gdbarch
= get_frame_arch (frame
);
6031 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6032 && ecs
->event_thread
->control
.trap_expected
6033 && gdbarch_single_step_through_delay_p (gdbarch
)
6034 && currently_stepping (ecs
->event_thread
))
6036 /* We're trying to step off a breakpoint. Turns out that we're
6037 also on an instruction that needs to be stepped multiple
6038 times before it's been fully executing. E.g., architectures
6039 with a delay slot. It needs to be stepped twice, once for
6040 the instruction and once for the delay slot. */
6041 int step_through_delay
6042 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6044 if (step_through_delay
)
6045 infrun_debug_printf ("step through delay");
6047 if (ecs
->event_thread
->control
.step_range_end
== 0
6048 && step_through_delay
)
6050 /* The user issued a continue when stopped at a breakpoint.
6051 Set up for another trap and get out of here. */
6052 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6056 else if (step_through_delay
)
6058 /* The user issued a step when stopped at a breakpoint.
6059 Maybe we should stop, maybe we should not - the delay
6060 slot *might* correspond to a line of source. In any
6061 case, don't decide that here, just set
6062 ecs->stepping_over_breakpoint, making sure we
6063 single-step again before breakpoints are re-inserted. */
6064 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6068 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6069 handles this event. */
6070 ecs
->event_thread
->control
.stop_bpstat
6071 = bpstat_stop_status (get_current_regcache ()->aspace (),
6072 ecs
->event_thread
->suspend
.stop_pc
,
6073 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6075 /* Following in case break condition called a
6077 stop_print_frame
= 1;
6079 /* This is where we handle "moribund" watchpoints. Unlike
6080 software breakpoints traps, hardware watchpoint traps are
6081 always distinguishable from random traps. If no high-level
6082 watchpoint is associated with the reported stop data address
6083 anymore, then the bpstat does not explain the signal ---
6084 simply make sure to ignore it if `stopped_by_watchpoint' is
6087 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6088 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6090 && stopped_by_watchpoint
)
6092 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6096 /* NOTE: cagney/2003-03-29: These checks for a random signal
6097 at one stage in the past included checks for an inferior
6098 function call's call dummy's return breakpoint. The original
6099 comment, that went with the test, read:
6101 ``End of a stack dummy. Some systems (e.g. Sony news) give
6102 another signal besides SIGTRAP, so check here as well as
6105 If someone ever tries to get call dummys on a
6106 non-executable stack to work (where the target would stop
6107 with something like a SIGSEGV), then those tests might need
6108 to be re-instated. Given, however, that the tests were only
6109 enabled when momentary breakpoints were not being used, I
6110 suspect that it won't be the case.
6112 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6113 be necessary for call dummies on a non-executable stack on
6116 /* See if the breakpoints module can explain the signal. */
6118 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6119 ecs
->event_thread
->suspend
.stop_signal
);
6121 /* Maybe this was a trap for a software breakpoint that has since
6123 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6125 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6126 ecs
->event_thread
->suspend
.stop_pc
))
6128 struct regcache
*regcache
;
6131 /* Re-adjust PC to what the program would see if GDB was not
6133 regcache
= get_thread_regcache (ecs
->event_thread
);
6134 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6137 gdb::optional
<scoped_restore_tmpl
<int>>
6138 restore_operation_disable
;
6140 if (record_full_is_used ())
6141 restore_operation_disable
.emplace
6142 (record_full_gdb_operation_disable_set ());
6144 regcache_write_pc (regcache
,
6145 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6150 /* A delayed software breakpoint event. Ignore the trap. */
6151 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6156 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6157 has since been removed. */
6158 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6160 /* A delayed hardware breakpoint event. Ignore the trap. */
6161 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6166 /* If not, perhaps stepping/nexting can. */
6168 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6169 && currently_stepping (ecs
->event_thread
));
6171 /* Perhaps the thread hit a single-step breakpoint of _another_
6172 thread. Single-step breakpoints are transparent to the
6173 breakpoints module. */
6175 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6177 /* No? Perhaps we got a moribund watchpoint. */
6179 random_signal
= !stopped_by_watchpoint
;
6181 /* Always stop if the user explicitly requested this thread to
6183 if (ecs
->event_thread
->stop_requested
)
6186 infrun_debug_printf ("user-requested stop");
6189 /* For the program's own signals, act according to
6190 the signal handling tables. */
6194 /* Signal not for debugging purposes. */
6195 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6196 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6198 infrun_debug_printf ("random signal (%s)",
6199 gdb_signal_to_symbol_string (stop_signal
));
6201 stopped_by_random_signal
= 1;
6203 /* Always stop on signals if we're either just gaining control
6204 of the program, or the user explicitly requested this thread
6205 to remain stopped. */
6206 if (stop_soon
!= NO_STOP_QUIETLY
6207 || ecs
->event_thread
->stop_requested
6209 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6215 /* Notify observers the signal has "handle print" set. Note we
6216 returned early above if stopping; normal_stop handles the
6217 printing in that case. */
6218 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6220 /* The signal table tells us to print about this signal. */
6221 target_terminal::ours_for_output ();
6222 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6223 target_terminal::inferior ();
6226 /* Clear the signal if it should not be passed. */
6227 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6228 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6230 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6231 && ecs
->event_thread
->control
.trap_expected
6232 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6234 /* We were just starting a new sequence, attempting to
6235 single-step off of a breakpoint and expecting a SIGTRAP.
6236 Instead this signal arrives. This signal will take us out
6237 of the stepping range so GDB needs to remember to, when
6238 the signal handler returns, resume stepping off that
6240 /* To simplify things, "continue" is forced to use the same
6241 code paths as single-step - set a breakpoint at the
6242 signal return address and then, once hit, step off that
6244 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6246 insert_hp_step_resume_breakpoint_at_frame (frame
);
6247 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6248 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6249 ecs
->event_thread
->control
.trap_expected
= 0;
6251 /* If we were nexting/stepping some other thread, switch to
6252 it, so that we don't continue it, losing control. */
6253 if (!switch_back_to_stepped_thread (ecs
))
6258 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6259 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6261 || ecs
->event_thread
->control
.step_range_end
== 1)
6262 && frame_id_eq (get_stack_frame_id (frame
),
6263 ecs
->event_thread
->control
.step_stack_frame_id
)
6264 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6266 /* The inferior is about to take a signal that will take it
6267 out of the single step range. Set a breakpoint at the
6268 current PC (which is presumably where the signal handler
6269 will eventually return) and then allow the inferior to
6272 Note that this is only needed for a signal delivered
6273 while in the single-step range. Nested signals aren't a
6274 problem as they eventually all return. */
6275 infrun_debug_printf ("signal may take us out of single-step range");
6277 clear_step_over_info ();
6278 insert_hp_step_resume_breakpoint_at_frame (frame
);
6279 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6280 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6281 ecs
->event_thread
->control
.trap_expected
= 0;
6286 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6287 when either there's a nested signal, or when there's a
6288 pending signal enabled just as the signal handler returns
6289 (leaving the inferior at the step-resume-breakpoint without
6290 actually executing it). Either way continue until the
6291 breakpoint is really hit. */
6293 if (!switch_back_to_stepped_thread (ecs
))
6295 infrun_debug_printf ("random signal, keep going");
6302 process_event_stop_test (ecs
);
6305 /* Come here when we've got some debug event / signal we can explain
6306 (IOW, not a random signal), and test whether it should cause a
6307 stop, or whether we should resume the inferior (transparently).
6308 E.g., could be a breakpoint whose condition evaluates false; we
6309 could be still stepping within the line; etc. */
6312 process_event_stop_test (struct execution_control_state
*ecs
)
6314 struct symtab_and_line stop_pc_sal
;
6315 struct frame_info
*frame
;
6316 struct gdbarch
*gdbarch
;
6317 CORE_ADDR jmp_buf_pc
;
6318 struct bpstat_what what
;
6320 /* Handle cases caused by hitting a breakpoint. */
6322 frame
= get_current_frame ();
6323 gdbarch
= get_frame_arch (frame
);
6325 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6327 if (what
.call_dummy
)
6329 stop_stack_dummy
= what
.call_dummy
;
6332 /* A few breakpoint types have callbacks associated (e.g.,
6333 bp_jit_event). Run them now. */
6334 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6336 /* If we hit an internal event that triggers symbol changes, the
6337 current frame will be invalidated within bpstat_what (e.g., if we
6338 hit an internal solib event). Re-fetch it. */
6339 frame
= get_current_frame ();
6340 gdbarch
= get_frame_arch (frame
);
6342 switch (what
.main_action
)
6344 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6345 /* If we hit the breakpoint at longjmp while stepping, we
6346 install a momentary breakpoint at the target of the
6349 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6351 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6353 if (what
.is_longjmp
)
6355 struct value
*arg_value
;
6357 /* If we set the longjmp breakpoint via a SystemTap probe,
6358 then use it to extract the arguments. The destination PC
6359 is the third argument to the probe. */
6360 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6363 jmp_buf_pc
= value_as_address (arg_value
);
6364 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6366 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6367 || !gdbarch_get_longjmp_target (gdbarch
,
6368 frame
, &jmp_buf_pc
))
6370 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6371 "(!gdbarch_get_longjmp_target)");
6376 /* Insert a breakpoint at resume address. */
6377 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6380 check_exception_resume (ecs
, frame
);
6384 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6386 struct frame_info
*init_frame
;
6388 /* There are several cases to consider.
6390 1. The initiating frame no longer exists. In this case we
6391 must stop, because the exception or longjmp has gone too
6394 2. The initiating frame exists, and is the same as the
6395 current frame. We stop, because the exception or longjmp
6398 3. The initiating frame exists and is different from the
6399 current frame. This means the exception or longjmp has
6400 been caught beneath the initiating frame, so keep going.
6402 4. longjmp breakpoint has been placed just to protect
6403 against stale dummy frames and user is not interested in
6404 stopping around longjmps. */
6406 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6408 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6410 delete_exception_resume_breakpoint (ecs
->event_thread
);
6412 if (what
.is_longjmp
)
6414 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6416 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6424 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6428 struct frame_id current_id
6429 = get_frame_id (get_current_frame ());
6430 if (frame_id_eq (current_id
,
6431 ecs
->event_thread
->initiating_frame
))
6433 /* Case 2. Fall through. */
6443 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6445 delete_step_resume_breakpoint (ecs
->event_thread
);
6447 end_stepping_range (ecs
);
6451 case BPSTAT_WHAT_SINGLE
:
6452 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6453 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6454 /* Still need to check other stuff, at least the case where we
6455 are stepping and step out of the right range. */
6458 case BPSTAT_WHAT_STEP_RESUME
:
6459 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6461 delete_step_resume_breakpoint (ecs
->event_thread
);
6462 if (ecs
->event_thread
->control
.proceed_to_finish
6463 && execution_direction
== EXEC_REVERSE
)
6465 struct thread_info
*tp
= ecs
->event_thread
;
6467 /* We are finishing a function in reverse, and just hit the
6468 step-resume breakpoint at the start address of the
6469 function, and we're almost there -- just need to back up
6470 by one more single-step, which should take us back to the
6472 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6476 fill_in_stop_func (gdbarch
, ecs
);
6477 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6478 && execution_direction
== EXEC_REVERSE
)
6480 /* We are stepping over a function call in reverse, and just
6481 hit the step-resume breakpoint at the start address of
6482 the function. Go back to single-stepping, which should
6483 take us back to the function call. */
6484 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6490 case BPSTAT_WHAT_STOP_NOISY
:
6491 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6492 stop_print_frame
= 1;
6494 /* Assume the thread stopped for a breakpoint. We'll still check
6495 whether a/the breakpoint is there when the thread is next
6497 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6502 case BPSTAT_WHAT_STOP_SILENT
:
6503 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6504 stop_print_frame
= 0;
6506 /* Assume the thread stopped for a breakpoint. We'll still check
6507 whether a/the breakpoint is there when the thread is next
6509 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6513 case BPSTAT_WHAT_HP_STEP_RESUME
:
6514 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6516 delete_step_resume_breakpoint (ecs
->event_thread
);
6517 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6519 /* Back when the step-resume breakpoint was inserted, we
6520 were trying to single-step off a breakpoint. Go back to
6522 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6523 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6529 case BPSTAT_WHAT_KEEP_CHECKING
:
6533 /* If we stepped a permanent breakpoint and we had a high priority
6534 step-resume breakpoint for the address we stepped, but we didn't
6535 hit it, then we must have stepped into the signal handler. The
6536 step-resume was only necessary to catch the case of _not_
6537 stepping into the handler, so delete it, and fall through to
6538 checking whether the step finished. */
6539 if (ecs
->event_thread
->stepped_breakpoint
)
6541 struct breakpoint
*sr_bp
6542 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6545 && sr_bp
->loc
->permanent
6546 && sr_bp
->type
== bp_hp_step_resume
6547 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6549 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6550 delete_step_resume_breakpoint (ecs
->event_thread
);
6551 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6555 /* We come here if we hit a breakpoint but should not stop for it.
6556 Possibly we also were stepping and should stop for that. So fall
6557 through and test for stepping. But, if not stepping, do not
6560 /* In all-stop mode, if we're currently stepping but have stopped in
6561 some other thread, we need to switch back to the stepped thread. */
6562 if (switch_back_to_stepped_thread (ecs
))
6565 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6567 infrun_debug_printf ("step-resume breakpoint is inserted");
6569 /* Having a step-resume breakpoint overrides anything
6570 else having to do with stepping commands until
6571 that breakpoint is reached. */
6576 if (ecs
->event_thread
->control
.step_range_end
== 0)
6578 infrun_debug_printf ("no stepping, continue");
6579 /* Likewise if we aren't even stepping. */
6584 /* Re-fetch current thread's frame in case the code above caused
6585 the frame cache to be re-initialized, making our FRAME variable
6586 a dangling pointer. */
6587 frame
= get_current_frame ();
6588 gdbarch
= get_frame_arch (frame
);
6589 fill_in_stop_func (gdbarch
, ecs
);
6591 /* If stepping through a line, keep going if still within it.
6593 Note that step_range_end is the address of the first instruction
6594 beyond the step range, and NOT the address of the last instruction
6597 Note also that during reverse execution, we may be stepping
6598 through a function epilogue and therefore must detect when
6599 the current-frame changes in the middle of a line. */
6601 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6603 && (execution_direction
!= EXEC_REVERSE
6604 || frame_id_eq (get_frame_id (frame
),
6605 ecs
->event_thread
->control
.step_frame_id
)))
6608 ("stepping inside range [%s-%s]",
6609 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6610 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6612 /* Tentatively re-enable range stepping; `resume' disables it if
6613 necessary (e.g., if we're stepping over a breakpoint or we
6614 have software watchpoints). */
6615 ecs
->event_thread
->control
.may_range_step
= 1;
6617 /* When stepping backward, stop at beginning of line range
6618 (unless it's the function entry point, in which case
6619 keep going back to the call point). */
6620 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6621 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6622 && stop_pc
!= ecs
->stop_func_start
6623 && execution_direction
== EXEC_REVERSE
)
6624 end_stepping_range (ecs
);
6631 /* We stepped out of the stepping range. */
6633 /* If we are stepping at the source level and entered the runtime
6634 loader dynamic symbol resolution code...
6636 EXEC_FORWARD: we keep on single stepping until we exit the run
6637 time loader code and reach the callee's address.
6639 EXEC_REVERSE: we've already executed the callee (backward), and
6640 the runtime loader code is handled just like any other
6641 undebuggable function call. Now we need only keep stepping
6642 backward through the trampoline code, and that's handled further
6643 down, so there is nothing for us to do here. */
6645 if (execution_direction
!= EXEC_REVERSE
6646 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6647 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6649 CORE_ADDR pc_after_resolver
=
6650 gdbarch_skip_solib_resolver (gdbarch
,
6651 ecs
->event_thread
->suspend
.stop_pc
);
6653 infrun_debug_printf ("stepped into dynsym resolve code");
6655 if (pc_after_resolver
)
6657 /* Set up a step-resume breakpoint at the address
6658 indicated by SKIP_SOLIB_RESOLVER. */
6659 symtab_and_line sr_sal
;
6660 sr_sal
.pc
= pc_after_resolver
;
6661 sr_sal
.pspace
= get_frame_program_space (frame
);
6663 insert_step_resume_breakpoint_at_sal (gdbarch
,
6664 sr_sal
, null_frame_id
);
6671 /* Step through an indirect branch thunk. */
6672 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6673 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6674 ecs
->event_thread
->suspend
.stop_pc
))
6676 infrun_debug_printf ("stepped into indirect branch thunk");
6681 if (ecs
->event_thread
->control
.step_range_end
!= 1
6682 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6683 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6684 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6686 infrun_debug_printf ("stepped into signal trampoline");
6687 /* The inferior, while doing a "step" or "next", has ended up in
6688 a signal trampoline (either by a signal being delivered or by
6689 the signal handler returning). Just single-step until the
6690 inferior leaves the trampoline (either by calling the handler
6696 /* If we're in the return path from a shared library trampoline,
6697 we want to proceed through the trampoline when stepping. */
6698 /* macro/2012-04-25: This needs to come before the subroutine
6699 call check below as on some targets return trampolines look
6700 like subroutine calls (MIPS16 return thunks). */
6701 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6702 ecs
->event_thread
->suspend
.stop_pc
,
6703 ecs
->stop_func_name
)
6704 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6706 /* Determine where this trampoline returns. */
6707 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6708 CORE_ADDR real_stop_pc
6709 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6711 infrun_debug_printf ("stepped into solib return tramp");
6713 /* Only proceed through if we know where it's going. */
6716 /* And put the step-breakpoint there and go until there. */
6717 symtab_and_line sr_sal
;
6718 sr_sal
.pc
= real_stop_pc
;
6719 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6720 sr_sal
.pspace
= get_frame_program_space (frame
);
6722 /* Do not specify what the fp should be when we stop since
6723 on some machines the prologue is where the new fp value
6725 insert_step_resume_breakpoint_at_sal (gdbarch
,
6726 sr_sal
, null_frame_id
);
6728 /* Restart without fiddling with the step ranges or
6735 /* Check for subroutine calls. The check for the current frame
6736 equalling the step ID is not necessary - the check of the
6737 previous frame's ID is sufficient - but it is a common case and
6738 cheaper than checking the previous frame's ID.
6740 NOTE: frame_id_eq will never report two invalid frame IDs as
6741 being equal, so to get into this block, both the current and
6742 previous frame must have valid frame IDs. */
6743 /* The outer_frame_id check is a heuristic to detect stepping
6744 through startup code. If we step over an instruction which
6745 sets the stack pointer from an invalid value to a valid value,
6746 we may detect that as a subroutine call from the mythical
6747 "outermost" function. This could be fixed by marking
6748 outermost frames as !stack_p,code_p,special_p. Then the
6749 initial outermost frame, before sp was valid, would
6750 have code_addr == &_start. See the comment in frame_id_eq
6752 if (!frame_id_eq (get_stack_frame_id (frame
),
6753 ecs
->event_thread
->control
.step_stack_frame_id
)
6754 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6755 ecs
->event_thread
->control
.step_stack_frame_id
)
6756 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6758 || (ecs
->event_thread
->control
.step_start_function
6759 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6761 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6762 CORE_ADDR real_stop_pc
;
6764 infrun_debug_printf ("stepped into subroutine");
6766 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6768 /* I presume that step_over_calls is only 0 when we're
6769 supposed to be stepping at the assembly language level
6770 ("stepi"). Just stop. */
6771 /* And this works the same backward as frontward. MVS */
6772 end_stepping_range (ecs
);
6776 /* Reverse stepping through solib trampolines. */
6778 if (execution_direction
== EXEC_REVERSE
6779 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6780 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6781 || (ecs
->stop_func_start
== 0
6782 && in_solib_dynsym_resolve_code (stop_pc
))))
6784 /* Any solib trampoline code can be handled in reverse
6785 by simply continuing to single-step. We have already
6786 executed the solib function (backwards), and a few
6787 steps will take us back through the trampoline to the
6793 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6795 /* We're doing a "next".
6797 Normal (forward) execution: set a breakpoint at the
6798 callee's return address (the address at which the caller
6801 Reverse (backward) execution. set the step-resume
6802 breakpoint at the start of the function that we just
6803 stepped into (backwards), and continue to there. When we
6804 get there, we'll need to single-step back to the caller. */
6806 if (execution_direction
== EXEC_REVERSE
)
6808 /* If we're already at the start of the function, we've either
6809 just stepped backward into a single instruction function,
6810 or stepped back out of a signal handler to the first instruction
6811 of the function. Just keep going, which will single-step back
6813 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6815 /* Normal function call return (static or dynamic). */
6816 symtab_and_line sr_sal
;
6817 sr_sal
.pc
= ecs
->stop_func_start
;
6818 sr_sal
.pspace
= get_frame_program_space (frame
);
6819 insert_step_resume_breakpoint_at_sal (gdbarch
,
6820 sr_sal
, null_frame_id
);
6824 insert_step_resume_breakpoint_at_caller (frame
);
6830 /* If we are in a function call trampoline (a stub between the
6831 calling routine and the real function), locate the real
6832 function. That's what tells us (a) whether we want to step
6833 into it at all, and (b) what prologue we want to run to the
6834 end of, if we do step into it. */
6835 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6836 if (real_stop_pc
== 0)
6837 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6838 if (real_stop_pc
!= 0)
6839 ecs
->stop_func_start
= real_stop_pc
;
6841 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6843 symtab_and_line sr_sal
;
6844 sr_sal
.pc
= ecs
->stop_func_start
;
6845 sr_sal
.pspace
= get_frame_program_space (frame
);
6847 insert_step_resume_breakpoint_at_sal (gdbarch
,
6848 sr_sal
, null_frame_id
);
6853 /* If we have line number information for the function we are
6854 thinking of stepping into and the function isn't on the skip
6857 If there are several symtabs at that PC (e.g. with include
6858 files), just want to know whether *any* of them have line
6859 numbers. find_pc_line handles this. */
6861 struct symtab_and_line tmp_sal
;
6863 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6864 if (tmp_sal
.line
!= 0
6865 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6867 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6869 if (execution_direction
== EXEC_REVERSE
)
6870 handle_step_into_function_backward (gdbarch
, ecs
);
6872 handle_step_into_function (gdbarch
, ecs
);
6877 /* If we have no line number and the step-stop-if-no-debug is
6878 set, we stop the step so that the user has a chance to switch
6879 in assembly mode. */
6880 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6881 && step_stop_if_no_debug
)
6883 end_stepping_range (ecs
);
6887 if (execution_direction
== EXEC_REVERSE
)
6889 /* If we're already at the start of the function, we've either just
6890 stepped backward into a single instruction function without line
6891 number info, or stepped back out of a signal handler to the first
6892 instruction of the function without line number info. Just keep
6893 going, which will single-step back to the caller. */
6894 if (ecs
->stop_func_start
!= stop_pc
)
6896 /* Set a breakpoint at callee's start address.
6897 From there we can step once and be back in the caller. */
6898 symtab_and_line sr_sal
;
6899 sr_sal
.pc
= ecs
->stop_func_start
;
6900 sr_sal
.pspace
= get_frame_program_space (frame
);
6901 insert_step_resume_breakpoint_at_sal (gdbarch
,
6902 sr_sal
, null_frame_id
);
6906 /* Set a breakpoint at callee's return address (the address
6907 at which the caller will resume). */
6908 insert_step_resume_breakpoint_at_caller (frame
);
6914 /* Reverse stepping through solib trampolines. */
6916 if (execution_direction
== EXEC_REVERSE
6917 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6919 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6921 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6922 || (ecs
->stop_func_start
== 0
6923 && in_solib_dynsym_resolve_code (stop_pc
)))
6925 /* Any solib trampoline code can be handled in reverse
6926 by simply continuing to single-step. We have already
6927 executed the solib function (backwards), and a few
6928 steps will take us back through the trampoline to the
6933 else if (in_solib_dynsym_resolve_code (stop_pc
))
6935 /* Stepped backward into the solib dynsym resolver.
6936 Set a breakpoint at its start and continue, then
6937 one more step will take us out. */
6938 symtab_and_line sr_sal
;
6939 sr_sal
.pc
= ecs
->stop_func_start
;
6940 sr_sal
.pspace
= get_frame_program_space (frame
);
6941 insert_step_resume_breakpoint_at_sal (gdbarch
,
6942 sr_sal
, null_frame_id
);
6948 /* This always returns the sal for the inner-most frame when we are in a
6949 stack of inlined frames, even if GDB actually believes that it is in a
6950 more outer frame. This is checked for below by calls to
6951 inline_skipped_frames. */
6952 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6954 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6955 the trampoline processing logic, however, there are some trampolines
6956 that have no names, so we should do trampoline handling first. */
6957 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6958 && ecs
->stop_func_name
== NULL
6959 && stop_pc_sal
.line
== 0)
6961 infrun_debug_printf ("stepped into undebuggable function");
6963 /* The inferior just stepped into, or returned to, an
6964 undebuggable function (where there is no debugging information
6965 and no line number corresponding to the address where the
6966 inferior stopped). Since we want to skip this kind of code,
6967 we keep going until the inferior returns from this
6968 function - unless the user has asked us not to (via
6969 set step-mode) or we no longer know how to get back
6970 to the call site. */
6971 if (step_stop_if_no_debug
6972 || !frame_id_p (frame_unwind_caller_id (frame
)))
6974 /* If we have no line number and the step-stop-if-no-debug
6975 is set, we stop the step so that the user has a chance to
6976 switch in assembly mode. */
6977 end_stepping_range (ecs
);
6982 /* Set a breakpoint at callee's return address (the address
6983 at which the caller will resume). */
6984 insert_step_resume_breakpoint_at_caller (frame
);
6990 if (ecs
->event_thread
->control
.step_range_end
== 1)
6992 /* It is stepi or nexti. We always want to stop stepping after
6994 infrun_debug_printf ("stepi/nexti");
6995 end_stepping_range (ecs
);
6999 if (stop_pc_sal
.line
== 0)
7001 /* We have no line number information. That means to stop
7002 stepping (does this always happen right after one instruction,
7003 when we do "s" in a function with no line numbers,
7004 or can this happen as a result of a return or longjmp?). */
7005 infrun_debug_printf ("line number info");
7006 end_stepping_range (ecs
);
7010 /* Look for "calls" to inlined functions, part one. If the inline
7011 frame machinery detected some skipped call sites, we have entered
7012 a new inline function. */
7014 if (frame_id_eq (get_frame_id (get_current_frame ()),
7015 ecs
->event_thread
->control
.step_frame_id
)
7016 && inline_skipped_frames (ecs
->event_thread
))
7018 infrun_debug_printf ("stepped into inlined function");
7020 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7022 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7024 /* For "step", we're going to stop. But if the call site
7025 for this inlined function is on the same source line as
7026 we were previously stepping, go down into the function
7027 first. Otherwise stop at the call site. */
7029 if (call_sal
.line
== ecs
->event_thread
->current_line
7030 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7032 step_into_inline_frame (ecs
->event_thread
);
7033 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7040 end_stepping_range (ecs
);
7045 /* For "next", we should stop at the call site if it is on a
7046 different source line. Otherwise continue through the
7047 inlined function. */
7048 if (call_sal
.line
== ecs
->event_thread
->current_line
7049 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7052 end_stepping_range (ecs
);
7057 /* Look for "calls" to inlined functions, part two. If we are still
7058 in the same real function we were stepping through, but we have
7059 to go further up to find the exact frame ID, we are stepping
7060 through a more inlined call beyond its call site. */
7062 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7063 && !frame_id_eq (get_frame_id (get_current_frame ()),
7064 ecs
->event_thread
->control
.step_frame_id
)
7065 && stepped_in_from (get_current_frame (),
7066 ecs
->event_thread
->control
.step_frame_id
))
7068 infrun_debug_printf ("stepping through inlined function");
7070 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7071 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7074 end_stepping_range (ecs
);
7078 bool refresh_step_info
= true;
7079 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7080 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7081 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7083 if (stop_pc_sal
.is_stmt
)
7085 /* We are at the start of a different line. So stop. Note that
7086 we don't stop if we step into the middle of a different line.
7087 That is said to make things like for (;;) statements work
7089 infrun_debug_printf ("stepped to a different line");
7090 end_stepping_range (ecs
);
7093 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7094 ecs
->event_thread
->control
.step_frame_id
))
7096 /* We are at the start of a different line, however, this line is
7097 not marked as a statement, and we have not changed frame. We
7098 ignore this line table entry, and continue stepping forward,
7099 looking for a better place to stop. */
7100 refresh_step_info
= false;
7101 infrun_debug_printf ("stepped to a different line, but "
7102 "it's not the start of a statement");
7106 /* We aren't done stepping.
7108 Optimize by setting the stepping range to the line.
7109 (We might not be in the original line, but if we entered a
7110 new line in mid-statement, we continue stepping. This makes
7111 things like for(;;) statements work better.)
7113 If we entered a SAL that indicates a non-statement line table entry,
7114 then we update the stepping range, but we don't update the step info,
7115 which includes things like the line number we are stepping away from.
7116 This means we will stop when we find a line table entry that is marked
7117 as is-statement, even if it matches the non-statement one we just
7120 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7121 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7122 ecs
->event_thread
->control
.may_range_step
= 1;
7123 if (refresh_step_info
)
7124 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7126 infrun_debug_printf ("keep going");
7130 /* In all-stop mode, if we're currently stepping but have stopped in
7131 some other thread, we may need to switch back to the stepped
7132 thread. Returns true we set the inferior running, false if we left
7133 it stopped (and the event needs further processing). */
7136 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7138 if (!target_is_non_stop_p ())
7140 struct thread_info
*stepping_thread
;
7142 /* If any thread is blocked on some internal breakpoint, and we
7143 simply need to step over that breakpoint to get it going
7144 again, do that first. */
7146 /* However, if we see an event for the stepping thread, then we
7147 know all other threads have been moved past their breakpoints
7148 already. Let the caller check whether the step is finished,
7149 etc., before deciding to move it past a breakpoint. */
7150 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7153 /* Check if the current thread is blocked on an incomplete
7154 step-over, interrupted by a random signal. */
7155 if (ecs
->event_thread
->control
.trap_expected
7156 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7159 ("need to finish step-over of [%s]",
7160 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7165 /* Check if the current thread is blocked by a single-step
7166 breakpoint of another thread. */
7167 if (ecs
->hit_singlestep_breakpoint
)
7169 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7170 target_pid_to_str (ecs
->ptid
).c_str ());
7175 /* If this thread needs yet another step-over (e.g., stepping
7176 through a delay slot), do it first before moving on to
7178 if (thread_still_needs_step_over (ecs
->event_thread
))
7181 ("thread [%s] still needs step-over",
7182 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7187 /* If scheduler locking applies even if not stepping, there's no
7188 need to walk over threads. Above we've checked whether the
7189 current thread is stepping. If some other thread not the
7190 event thread is stepping, then it must be that scheduler
7191 locking is not in effect. */
7192 if (schedlock_applies (ecs
->event_thread
))
7195 /* Otherwise, we no longer expect a trap in the current thread.
7196 Clear the trap_expected flag before switching back -- this is
7197 what keep_going does as well, if we call it. */
7198 ecs
->event_thread
->control
.trap_expected
= 0;
7200 /* Likewise, clear the signal if it should not be passed. */
7201 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7202 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7204 /* Do all pending step-overs before actually proceeding with
7206 if (start_step_over ())
7208 prepare_to_wait (ecs
);
7212 /* Look for the stepping/nexting thread. */
7213 stepping_thread
= NULL
;
7215 for (thread_info
*tp
: all_non_exited_threads ())
7217 switch_to_thread_no_regs (tp
);
7219 /* Ignore threads of processes the caller is not
7222 && (tp
->inf
->process_target () != ecs
->target
7223 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7226 /* When stepping over a breakpoint, we lock all threads
7227 except the one that needs to move past the breakpoint.
7228 If a non-event thread has this set, the "incomplete
7229 step-over" check above should have caught it earlier. */
7230 if (tp
->control
.trap_expected
)
7232 internal_error (__FILE__
, __LINE__
,
7233 "[%s] has inconsistent state: "
7234 "trap_expected=%d\n",
7235 target_pid_to_str (tp
->ptid
).c_str (),
7236 tp
->control
.trap_expected
);
7239 /* Did we find the stepping thread? */
7240 if (tp
->control
.step_range_end
)
7242 /* Yep. There should only one though. */
7243 gdb_assert (stepping_thread
== NULL
);
7245 /* The event thread is handled at the top, before we
7247 gdb_assert (tp
!= ecs
->event_thread
);
7249 /* If some thread other than the event thread is
7250 stepping, then scheduler locking can't be in effect,
7251 otherwise we wouldn't have resumed the current event
7252 thread in the first place. */
7253 gdb_assert (!schedlock_applies (tp
));
7255 stepping_thread
= tp
;
7259 if (stepping_thread
!= NULL
)
7261 infrun_debug_printf ("switching back to stepped thread");
7263 if (keep_going_stepped_thread (stepping_thread
))
7265 prepare_to_wait (ecs
);
7270 switch_to_thread (ecs
->event_thread
);
7276 /* Set a previously stepped thread back to stepping. Returns true on
7277 success, false if the resume is not possible (e.g., the thread
7281 keep_going_stepped_thread (struct thread_info
*tp
)
7283 struct frame_info
*frame
;
7284 struct execution_control_state ecss
;
7285 struct execution_control_state
*ecs
= &ecss
;
7287 /* If the stepping thread exited, then don't try to switch back and
7288 resume it, which could fail in several different ways depending
7289 on the target. Instead, just keep going.
7291 We can find a stepping dead thread in the thread list in two
7294 - The target supports thread exit events, and when the target
7295 tries to delete the thread from the thread list, inferior_ptid
7296 pointed at the exiting thread. In such case, calling
7297 delete_thread does not really remove the thread from the list;
7298 instead, the thread is left listed, with 'exited' state.
7300 - The target's debug interface does not support thread exit
7301 events, and so we have no idea whatsoever if the previously
7302 stepping thread is still alive. For that reason, we need to
7303 synchronously query the target now. */
7305 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7307 infrun_debug_printf ("not resuming previously stepped thread, it has "
7314 infrun_debug_printf ("resuming previously stepped thread");
7316 reset_ecs (ecs
, tp
);
7317 switch_to_thread (tp
);
7319 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7320 frame
= get_current_frame ();
7322 /* If the PC of the thread we were trying to single-step has
7323 changed, then that thread has trapped or been signaled, but the
7324 event has not been reported to GDB yet. Re-poll the target
7325 looking for this particular thread's event (i.e. temporarily
7326 enable schedlock) by:
7328 - setting a break at the current PC
7329 - resuming that particular thread, only (by setting trap
7332 This prevents us continuously moving the single-step breakpoint
7333 forward, one instruction at a time, overstepping. */
7335 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7339 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7340 paddress (target_gdbarch (), tp
->prev_pc
),
7341 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7343 /* Clear the info of the previous step-over, as it's no longer
7344 valid (if the thread was trying to step over a breakpoint, it
7345 has already succeeded). It's what keep_going would do too,
7346 if we called it. Do this before trying to insert the sss
7347 breakpoint, otherwise if we were previously trying to step
7348 over this exact address in another thread, the breakpoint is
7350 clear_step_over_info ();
7351 tp
->control
.trap_expected
= 0;
7353 insert_single_step_breakpoint (get_frame_arch (frame
),
7354 get_frame_address_space (frame
),
7355 tp
->suspend
.stop_pc
);
7358 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7359 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7363 infrun_debug_printf ("expected thread still hasn't advanced");
7365 keep_going_pass_signal (ecs
);
7370 /* Is thread TP in the middle of (software or hardware)
7371 single-stepping? (Note the result of this function must never be
7372 passed directly as target_resume's STEP parameter.) */
7375 currently_stepping (struct thread_info
*tp
)
7377 return ((tp
->control
.step_range_end
7378 && tp
->control
.step_resume_breakpoint
== NULL
)
7379 || tp
->control
.trap_expected
7380 || tp
->stepped_breakpoint
7381 || bpstat_should_step ());
7384 /* Inferior has stepped into a subroutine call with source code that
7385 we should not step over. Do step to the first line of code in
7389 handle_step_into_function (struct gdbarch
*gdbarch
,
7390 struct execution_control_state
*ecs
)
7392 fill_in_stop_func (gdbarch
, ecs
);
7394 compunit_symtab
*cust
7395 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7396 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7397 ecs
->stop_func_start
7398 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7400 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7401 /* Use the step_resume_break to step until the end of the prologue,
7402 even if that involves jumps (as it seems to on the vax under
7404 /* If the prologue ends in the middle of a source line, continue to
7405 the end of that source line (if it is still within the function).
7406 Otherwise, just go to end of prologue. */
7407 if (stop_func_sal
.end
7408 && stop_func_sal
.pc
!= ecs
->stop_func_start
7409 && stop_func_sal
.end
< ecs
->stop_func_end
)
7410 ecs
->stop_func_start
= stop_func_sal
.end
;
7412 /* Architectures which require breakpoint adjustment might not be able
7413 to place a breakpoint at the computed address. If so, the test
7414 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7415 ecs->stop_func_start to an address at which a breakpoint may be
7416 legitimately placed.
7418 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7419 made, GDB will enter an infinite loop when stepping through
7420 optimized code consisting of VLIW instructions which contain
7421 subinstructions corresponding to different source lines. On
7422 FR-V, it's not permitted to place a breakpoint on any but the
7423 first subinstruction of a VLIW instruction. When a breakpoint is
7424 set, GDB will adjust the breakpoint address to the beginning of
7425 the VLIW instruction. Thus, we need to make the corresponding
7426 adjustment here when computing the stop address. */
7428 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7430 ecs
->stop_func_start
7431 = gdbarch_adjust_breakpoint_address (gdbarch
,
7432 ecs
->stop_func_start
);
7435 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7437 /* We are already there: stop now. */
7438 end_stepping_range (ecs
);
7443 /* Put the step-breakpoint there and go until there. */
7444 symtab_and_line sr_sal
;
7445 sr_sal
.pc
= ecs
->stop_func_start
;
7446 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7447 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7449 /* Do not specify what the fp should be when we stop since on
7450 some machines the prologue is where the new fp value is
7452 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7454 /* And make sure stepping stops right away then. */
7455 ecs
->event_thread
->control
.step_range_end
7456 = ecs
->event_thread
->control
.step_range_start
;
7461 /* Inferior has stepped backward into a subroutine call with source
7462 code that we should not step over. Do step to the beginning of the
7463 last line of code in it. */
7466 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7467 struct execution_control_state
*ecs
)
7469 struct compunit_symtab
*cust
;
7470 struct symtab_and_line stop_func_sal
;
7472 fill_in_stop_func (gdbarch
, ecs
);
7474 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7475 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7476 ecs
->stop_func_start
7477 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7479 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7481 /* OK, we're just going to keep stepping here. */
7482 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7484 /* We're there already. Just stop stepping now. */
7485 end_stepping_range (ecs
);
7489 /* Else just reset the step range and keep going.
7490 No step-resume breakpoint, they don't work for
7491 epilogues, which can have multiple entry paths. */
7492 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7493 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7499 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7500 This is used to both functions and to skip over code. */
7503 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7504 struct symtab_and_line sr_sal
,
7505 struct frame_id sr_id
,
7506 enum bptype sr_type
)
7508 /* There should never be more than one step-resume or longjmp-resume
7509 breakpoint per thread, so we should never be setting a new
7510 step_resume_breakpoint when one is already active. */
7511 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7512 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7514 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7515 paddress (gdbarch
, sr_sal
.pc
));
7517 inferior_thread ()->control
.step_resume_breakpoint
7518 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7522 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7523 struct symtab_and_line sr_sal
,
7524 struct frame_id sr_id
)
7526 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7531 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7532 This is used to skip a potential signal handler.
7534 This is called with the interrupted function's frame. The signal
7535 handler, when it returns, will resume the interrupted function at
7539 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7541 gdb_assert (return_frame
!= NULL
);
7543 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7545 symtab_and_line sr_sal
;
7546 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7547 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7548 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7550 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7551 get_stack_frame_id (return_frame
),
7555 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7556 is used to skip a function after stepping into it (for "next" or if
7557 the called function has no debugging information).
7559 The current function has almost always been reached by single
7560 stepping a call or return instruction. NEXT_FRAME belongs to the
7561 current function, and the breakpoint will be set at the caller's
7564 This is a separate function rather than reusing
7565 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7566 get_prev_frame, which may stop prematurely (see the implementation
7567 of frame_unwind_caller_id for an example). */
7570 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7572 /* We shouldn't have gotten here if we don't know where the call site
7574 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7576 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7578 symtab_and_line sr_sal
;
7579 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7580 frame_unwind_caller_pc (next_frame
));
7581 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7582 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7584 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7585 frame_unwind_caller_id (next_frame
));
7588 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7589 new breakpoint at the target of a jmp_buf. The handling of
7590 longjmp-resume uses the same mechanisms used for handling
7591 "step-resume" breakpoints. */
7594 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7596 /* There should never be more than one longjmp-resume breakpoint per
7597 thread, so we should never be setting a new
7598 longjmp_resume_breakpoint when one is already active. */
7599 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7601 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7602 paddress (gdbarch
, pc
));
7604 inferior_thread ()->control
.exception_resume_breakpoint
=
7605 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7608 /* Insert an exception resume breakpoint. TP is the thread throwing
7609 the exception. The block B is the block of the unwinder debug hook
7610 function. FRAME is the frame corresponding to the call to this
7611 function. SYM is the symbol of the function argument holding the
7612 target PC of the exception. */
7615 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7616 const struct block
*b
,
7617 struct frame_info
*frame
,
7622 struct block_symbol vsym
;
7623 struct value
*value
;
7625 struct breakpoint
*bp
;
7627 vsym
= lookup_symbol_search_name (sym
->search_name (),
7629 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7630 /* If the value was optimized out, revert to the old behavior. */
7631 if (! value_optimized_out (value
))
7633 handler
= value_as_address (value
);
7635 infrun_debug_printf ("exception resume at %lx",
7636 (unsigned long) handler
);
7638 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7640 bp_exception_resume
).release ();
7642 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7645 bp
->thread
= tp
->global_num
;
7646 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7649 catch (const gdb_exception_error
&e
)
7651 /* We want to ignore errors here. */
7655 /* A helper for check_exception_resume that sets an
7656 exception-breakpoint based on a SystemTap probe. */
7659 insert_exception_resume_from_probe (struct thread_info
*tp
,
7660 const struct bound_probe
*probe
,
7661 struct frame_info
*frame
)
7663 struct value
*arg_value
;
7665 struct breakpoint
*bp
;
7667 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7671 handler
= value_as_address (arg_value
);
7673 infrun_debug_printf ("exception resume at %s",
7674 paddress (probe
->objfile
->arch (), handler
));
7676 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7677 handler
, bp_exception_resume
).release ();
7678 bp
->thread
= tp
->global_num
;
7679 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7682 /* This is called when an exception has been intercepted. Check to
7683 see whether the exception's destination is of interest, and if so,
7684 set an exception resume breakpoint there. */
7687 check_exception_resume (struct execution_control_state
*ecs
,
7688 struct frame_info
*frame
)
7690 struct bound_probe probe
;
7691 struct symbol
*func
;
7693 /* First see if this exception unwinding breakpoint was set via a
7694 SystemTap probe point. If so, the probe has two arguments: the
7695 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7696 set a breakpoint there. */
7697 probe
= find_probe_by_pc (get_frame_pc (frame
));
7700 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7704 func
= get_frame_function (frame
);
7710 const struct block
*b
;
7711 struct block_iterator iter
;
7715 /* The exception breakpoint is a thread-specific breakpoint on
7716 the unwinder's debug hook, declared as:
7718 void _Unwind_DebugHook (void *cfa, void *handler);
7720 The CFA argument indicates the frame to which control is
7721 about to be transferred. HANDLER is the destination PC.
7723 We ignore the CFA and set a temporary breakpoint at HANDLER.
7724 This is not extremely efficient but it avoids issues in gdb
7725 with computing the DWARF CFA, and it also works even in weird
7726 cases such as throwing an exception from inside a signal
7729 b
= SYMBOL_BLOCK_VALUE (func
);
7730 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7732 if (!SYMBOL_IS_ARGUMENT (sym
))
7739 insert_exception_resume_breakpoint (ecs
->event_thread
,
7745 catch (const gdb_exception_error
&e
)
7751 stop_waiting (struct execution_control_state
*ecs
)
7753 infrun_debug_printf ("stop_waiting");
7755 /* Let callers know we don't want to wait for the inferior anymore. */
7756 ecs
->wait_some_more
= 0;
7758 /* If all-stop, but there exists a non-stop target, stop all
7759 threads now that we're presenting the stop to the user. */
7760 if (!non_stop
&& exists_non_stop_target ())
7761 stop_all_threads ();
7764 /* Like keep_going, but passes the signal to the inferior, even if the
7765 signal is set to nopass. */
7768 keep_going_pass_signal (struct execution_control_state
*ecs
)
7770 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7771 gdb_assert (!ecs
->event_thread
->resumed
);
7773 /* Save the pc before execution, to compare with pc after stop. */
7774 ecs
->event_thread
->prev_pc
7775 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7777 if (ecs
->event_thread
->control
.trap_expected
)
7779 struct thread_info
*tp
= ecs
->event_thread
;
7781 infrun_debug_printf ("%s has trap_expected set, "
7782 "resuming to collect trap",
7783 target_pid_to_str (tp
->ptid
).c_str ());
7785 /* We haven't yet gotten our trap, and either: intercepted a
7786 non-signal event (e.g., a fork); or took a signal which we
7787 are supposed to pass through to the inferior. Simply
7789 resume (ecs
->event_thread
->suspend
.stop_signal
);
7791 else if (step_over_info_valid_p ())
7793 /* Another thread is stepping over a breakpoint in-line. If
7794 this thread needs a step-over too, queue the request. In
7795 either case, this resume must be deferred for later. */
7796 struct thread_info
*tp
= ecs
->event_thread
;
7798 if (ecs
->hit_singlestep_breakpoint
7799 || thread_still_needs_step_over (tp
))
7801 infrun_debug_printf ("step-over already in progress: "
7802 "step-over for %s deferred",
7803 target_pid_to_str (tp
->ptid
).c_str ());
7804 thread_step_over_chain_enqueue (tp
);
7808 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7809 target_pid_to_str (tp
->ptid
).c_str ());
7814 struct regcache
*regcache
= get_current_regcache ();
7817 step_over_what step_what
;
7819 /* Either the trap was not expected, but we are continuing
7820 anyway (if we got a signal, the user asked it be passed to
7823 We got our expected trap, but decided we should resume from
7826 We're going to run this baby now!
7828 Note that insert_breakpoints won't try to re-insert
7829 already inserted breakpoints. Therefore, we don't
7830 care if breakpoints were already inserted, or not. */
7832 /* If we need to step over a breakpoint, and we're not using
7833 displaced stepping to do so, insert all breakpoints
7834 (watchpoints, etc.) but the one we're stepping over, step one
7835 instruction, and then re-insert the breakpoint when that step
7838 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7840 remove_bp
= (ecs
->hit_singlestep_breakpoint
7841 || (step_what
& STEP_OVER_BREAKPOINT
));
7842 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7844 /* We can't use displaced stepping if we need to step past a
7845 watchpoint. The instruction copied to the scratch pad would
7846 still trigger the watchpoint. */
7848 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7850 set_step_over_info (regcache
->aspace (),
7851 regcache_read_pc (regcache
), remove_wps
,
7852 ecs
->event_thread
->global_num
);
7854 else if (remove_wps
)
7855 set_step_over_info (NULL
, 0, remove_wps
, -1);
7857 /* If we now need to do an in-line step-over, we need to stop
7858 all other threads. Note this must be done before
7859 insert_breakpoints below, because that removes the breakpoint
7860 we're about to step over, otherwise other threads could miss
7862 if (step_over_info_valid_p () && target_is_non_stop_p ())
7863 stop_all_threads ();
7865 /* Stop stepping if inserting breakpoints fails. */
7868 insert_breakpoints ();
7870 catch (const gdb_exception_error
&e
)
7872 exception_print (gdb_stderr
, e
);
7874 clear_step_over_info ();
7878 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7880 resume (ecs
->event_thread
->suspend
.stop_signal
);
7883 prepare_to_wait (ecs
);
7886 /* Called when we should continue running the inferior, because the
7887 current event doesn't cause a user visible stop. This does the
7888 resuming part; waiting for the next event is done elsewhere. */
7891 keep_going (struct execution_control_state
*ecs
)
7893 if (ecs
->event_thread
->control
.trap_expected
7894 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7895 ecs
->event_thread
->control
.trap_expected
= 0;
7897 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7898 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7899 keep_going_pass_signal (ecs
);
7902 /* This function normally comes after a resume, before
7903 handle_inferior_event exits. It takes care of any last bits of
7904 housekeeping, and sets the all-important wait_some_more flag. */
7907 prepare_to_wait (struct execution_control_state
*ecs
)
7909 infrun_debug_printf ("prepare_to_wait");
7911 ecs
->wait_some_more
= 1;
7913 /* If the target can't async, emulate it by marking the infrun event
7914 handler such that as soon as we get back to the event-loop, we
7915 immediately end up in fetch_inferior_event again calling
7917 if (!target_can_async_p ())
7918 mark_infrun_async_event_handler ();
7921 /* We are done with the step range of a step/next/si/ni command.
7922 Called once for each n of a "step n" operation. */
7925 end_stepping_range (struct execution_control_state
*ecs
)
7927 ecs
->event_thread
->control
.stop_step
= 1;
7931 /* Several print_*_reason functions to print why the inferior has stopped.
7932 We always print something when the inferior exits, or receives a signal.
7933 The rest of the cases are dealt with later on in normal_stop and
7934 print_it_typical. Ideally there should be a call to one of these
7935 print_*_reason functions functions from handle_inferior_event each time
7936 stop_waiting is called.
7938 Note that we don't call these directly, instead we delegate that to
7939 the interpreters, through observers. Interpreters then call these
7940 with whatever uiout is right. */
7943 print_end_stepping_range_reason (struct ui_out
*uiout
)
7945 /* For CLI-like interpreters, print nothing. */
7947 if (uiout
->is_mi_like_p ())
7949 uiout
->field_string ("reason",
7950 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7955 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7957 annotate_signalled ();
7958 if (uiout
->is_mi_like_p ())
7960 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7961 uiout
->text ("\nProgram terminated with signal ");
7962 annotate_signal_name ();
7963 uiout
->field_string ("signal-name",
7964 gdb_signal_to_name (siggnal
));
7965 annotate_signal_name_end ();
7967 annotate_signal_string ();
7968 uiout
->field_string ("signal-meaning",
7969 gdb_signal_to_string (siggnal
));
7970 annotate_signal_string_end ();
7971 uiout
->text (".\n");
7972 uiout
->text ("The program no longer exists.\n");
7976 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7978 struct inferior
*inf
= current_inferior ();
7979 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7981 annotate_exited (exitstatus
);
7984 if (uiout
->is_mi_like_p ())
7985 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7986 std::string exit_code_str
7987 = string_printf ("0%o", (unsigned int) exitstatus
);
7988 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7989 plongest (inf
->num
), pidstr
.c_str (),
7990 string_field ("exit-code", exit_code_str
.c_str ()));
7994 if (uiout
->is_mi_like_p ())
7996 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7997 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7998 plongest (inf
->num
), pidstr
.c_str ());
8003 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8005 struct thread_info
*thr
= inferior_thread ();
8009 if (uiout
->is_mi_like_p ())
8011 else if (show_thread_that_caused_stop ())
8015 uiout
->text ("\nThread ");
8016 uiout
->field_string ("thread-id", print_thread_id (thr
));
8018 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8021 uiout
->text (" \"");
8022 uiout
->field_string ("name", name
);
8027 uiout
->text ("\nProgram");
8029 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8030 uiout
->text (" stopped");
8033 uiout
->text (" received signal ");
8034 annotate_signal_name ();
8035 if (uiout
->is_mi_like_p ())
8037 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8038 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8039 annotate_signal_name_end ();
8041 annotate_signal_string ();
8042 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8044 struct regcache
*regcache
= get_current_regcache ();
8045 struct gdbarch
*gdbarch
= regcache
->arch ();
8046 if (gdbarch_report_signal_info_p (gdbarch
))
8047 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8049 annotate_signal_string_end ();
8051 uiout
->text (".\n");
8055 print_no_history_reason (struct ui_out
*uiout
)
8057 uiout
->text ("\nNo more reverse-execution history.\n");
8060 /* Print current location without a level number, if we have changed
8061 functions or hit a breakpoint. Print source line if we have one.
8062 bpstat_print contains the logic deciding in detail what to print,
8063 based on the event(s) that just occurred. */
8066 print_stop_location (struct target_waitstatus
*ws
)
8069 enum print_what source_flag
;
8070 int do_frame_printing
= 1;
8071 struct thread_info
*tp
= inferior_thread ();
8073 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8077 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8078 should) carry around the function and does (or should) use
8079 that when doing a frame comparison. */
8080 if (tp
->control
.stop_step
8081 && frame_id_eq (tp
->control
.step_frame_id
,
8082 get_frame_id (get_current_frame ()))
8083 && (tp
->control
.step_start_function
8084 == find_pc_function (tp
->suspend
.stop_pc
)))
8086 /* Finished step, just print source line. */
8087 source_flag
= SRC_LINE
;
8091 /* Print location and source line. */
8092 source_flag
= SRC_AND_LOC
;
8095 case PRINT_SRC_AND_LOC
:
8096 /* Print location and source line. */
8097 source_flag
= SRC_AND_LOC
;
8099 case PRINT_SRC_ONLY
:
8100 source_flag
= SRC_LINE
;
8103 /* Something bogus. */
8104 source_flag
= SRC_LINE
;
8105 do_frame_printing
= 0;
8108 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8111 /* The behavior of this routine with respect to the source
8113 SRC_LINE: Print only source line
8114 LOCATION: Print only location
8115 SRC_AND_LOC: Print location and source line. */
8116 if (do_frame_printing
)
8117 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8123 print_stop_event (struct ui_out
*uiout
, bool displays
)
8125 struct target_waitstatus last
;
8126 struct thread_info
*tp
;
8128 get_last_target_status (nullptr, nullptr, &last
);
8131 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8133 print_stop_location (&last
);
8135 /* Display the auto-display expressions. */
8140 tp
= inferior_thread ();
8141 if (tp
->thread_fsm
!= NULL
8142 && tp
->thread_fsm
->finished_p ())
8144 struct return_value_info
*rv
;
8146 rv
= tp
->thread_fsm
->return_value ();
8148 print_return_value (uiout
, rv
);
8155 maybe_remove_breakpoints (void)
8157 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8159 if (remove_breakpoints ())
8161 target_terminal::ours_for_output ();
8162 printf_filtered (_("Cannot remove breakpoints because "
8163 "program is no longer writable.\nFurther "
8164 "execution is probably impossible.\n"));
8169 /* The execution context that just caused a normal stop. */
8176 DISABLE_COPY_AND_ASSIGN (stop_context
);
8178 bool changed () const;
8183 /* The event PTID. */
8187 /* If stopp for a thread event, this is the thread that caused the
8189 struct thread_info
*thread
;
8191 /* The inferior that caused the stop. */
8195 /* Initializes a new stop context. If stopped for a thread event, this
8196 takes a strong reference to the thread. */
8198 stop_context::stop_context ()
8200 stop_id
= get_stop_id ();
8201 ptid
= inferior_ptid
;
8202 inf_num
= current_inferior ()->num
;
8204 if (inferior_ptid
!= null_ptid
)
8206 /* Take a strong reference so that the thread can't be deleted
8208 thread
= inferior_thread ();
8215 /* Release a stop context previously created with save_stop_context.
8216 Releases the strong reference to the thread as well. */
8218 stop_context::~stop_context ()
8224 /* Return true if the current context no longer matches the saved stop
8228 stop_context::changed () const
8230 if (ptid
!= inferior_ptid
)
8232 if (inf_num
!= current_inferior ()->num
)
8234 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8236 if (get_stop_id () != stop_id
)
8246 struct target_waitstatus last
;
8248 get_last_target_status (nullptr, nullptr, &last
);
8252 /* If an exception is thrown from this point on, make sure to
8253 propagate GDB's knowledge of the executing state to the
8254 frontend/user running state. A QUIT is an easy exception to see
8255 here, so do this before any filtered output. */
8257 ptid_t finish_ptid
= null_ptid
;
8260 finish_ptid
= minus_one_ptid
;
8261 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8262 || last
.kind
== TARGET_WAITKIND_EXITED
)
8264 /* On some targets, we may still have live threads in the
8265 inferior when we get a process exit event. E.g., for
8266 "checkpoint", when the current checkpoint/fork exits,
8267 linux-fork.c automatically switches to another fork from
8268 within target_mourn_inferior. */
8269 if (inferior_ptid
!= null_ptid
)
8270 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8272 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8273 finish_ptid
= inferior_ptid
;
8275 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8276 if (finish_ptid
!= null_ptid
)
8278 maybe_finish_thread_state
.emplace
8279 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8282 /* As we're presenting a stop, and potentially removing breakpoints,
8283 update the thread list so we can tell whether there are threads
8284 running on the target. With target remote, for example, we can
8285 only learn about new threads when we explicitly update the thread
8286 list. Do this before notifying the interpreters about signal
8287 stops, end of stepping ranges, etc., so that the "new thread"
8288 output is emitted before e.g., "Program received signal FOO",
8289 instead of after. */
8290 update_thread_list ();
8292 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8293 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8295 /* As with the notification of thread events, we want to delay
8296 notifying the user that we've switched thread context until
8297 the inferior actually stops.
8299 There's no point in saying anything if the inferior has exited.
8300 Note that SIGNALLED here means "exited with a signal", not
8301 "received a signal".
8303 Also skip saying anything in non-stop mode. In that mode, as we
8304 don't want GDB to switch threads behind the user's back, to avoid
8305 races where the user is typing a command to apply to thread x,
8306 but GDB switches to thread y before the user finishes entering
8307 the command, fetch_inferior_event installs a cleanup to restore
8308 the current thread back to the thread the user had selected right
8309 after this event is handled, so we're not really switching, only
8310 informing of a stop. */
8312 && previous_inferior_ptid
!= inferior_ptid
8313 && target_has_execution ()
8314 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8315 && last
.kind
!= TARGET_WAITKIND_EXITED
8316 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8318 SWITCH_THRU_ALL_UIS ()
8320 target_terminal::ours_for_output ();
8321 printf_filtered (_("[Switching to %s]\n"),
8322 target_pid_to_str (inferior_ptid
).c_str ());
8323 annotate_thread_changed ();
8325 previous_inferior_ptid
= inferior_ptid
;
8328 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8330 SWITCH_THRU_ALL_UIS ()
8331 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8333 target_terminal::ours_for_output ();
8334 printf_filtered (_("No unwaited-for children left.\n"));
8338 /* Note: this depends on the update_thread_list call above. */
8339 maybe_remove_breakpoints ();
8341 /* If an auto-display called a function and that got a signal,
8342 delete that auto-display to avoid an infinite recursion. */
8344 if (stopped_by_random_signal
)
8345 disable_current_display ();
8347 SWITCH_THRU_ALL_UIS ()
8349 async_enable_stdin ();
8352 /* Let the user/frontend see the threads as stopped. */
8353 maybe_finish_thread_state
.reset ();
8355 /* Select innermost stack frame - i.e., current frame is frame 0,
8356 and current location is based on that. Handle the case where the
8357 dummy call is returning after being stopped. E.g. the dummy call
8358 previously hit a breakpoint. (If the dummy call returns
8359 normally, we won't reach here.) Do this before the stop hook is
8360 run, so that it doesn't get to see the temporary dummy frame,
8361 which is not where we'll present the stop. */
8362 if (has_stack_frames ())
8364 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8366 /* Pop the empty frame that contains the stack dummy. This
8367 also restores inferior state prior to the call (struct
8368 infcall_suspend_state). */
8369 struct frame_info
*frame
= get_current_frame ();
8371 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8373 /* frame_pop calls reinit_frame_cache as the last thing it
8374 does which means there's now no selected frame. */
8377 select_frame (get_current_frame ());
8379 /* Set the current source location. */
8380 set_current_sal_from_frame (get_current_frame ());
8383 /* Look up the hook_stop and run it (CLI internally handles problem
8384 of stop_command's pre-hook not existing). */
8385 if (stop_command
!= NULL
)
8387 stop_context saved_context
;
8391 execute_cmd_pre_hook (stop_command
);
8393 catch (const gdb_exception
&ex
)
8395 exception_fprintf (gdb_stderr
, ex
,
8396 "Error while running hook_stop:\n");
8399 /* If the stop hook resumes the target, then there's no point in
8400 trying to notify about the previous stop; its context is
8401 gone. Likewise if the command switches thread or inferior --
8402 the observers would print a stop for the wrong
8404 if (saved_context
.changed ())
8408 /* Notify observers about the stop. This is where the interpreters
8409 print the stop event. */
8410 if (inferior_ptid
!= null_ptid
)
8411 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8414 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8416 annotate_stopped ();
8418 if (target_has_execution ())
8420 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8421 && last
.kind
!= TARGET_WAITKIND_EXITED
8422 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8423 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8424 Delete any breakpoint that is to be deleted at the next stop. */
8425 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8428 /* Try to get rid of automatically added inferiors that are no
8429 longer needed. Keeping those around slows down things linearly.
8430 Note that this never removes the current inferior. */
8437 signal_stop_state (int signo
)
8439 return signal_stop
[signo
];
8443 signal_print_state (int signo
)
8445 return signal_print
[signo
];
8449 signal_pass_state (int signo
)
8451 return signal_program
[signo
];
8455 signal_cache_update (int signo
)
8459 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8460 signal_cache_update (signo
);
8465 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8466 && signal_print
[signo
] == 0
8467 && signal_program
[signo
] == 1
8468 && signal_catch
[signo
] == 0);
8472 signal_stop_update (int signo
, int state
)
8474 int ret
= signal_stop
[signo
];
8476 signal_stop
[signo
] = state
;
8477 signal_cache_update (signo
);
8482 signal_print_update (int signo
, int state
)
8484 int ret
= signal_print
[signo
];
8486 signal_print
[signo
] = state
;
8487 signal_cache_update (signo
);
8492 signal_pass_update (int signo
, int state
)
8494 int ret
= signal_program
[signo
];
8496 signal_program
[signo
] = state
;
8497 signal_cache_update (signo
);
8501 /* Update the global 'signal_catch' from INFO and notify the
8505 signal_catch_update (const unsigned int *info
)
8509 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8510 signal_catch
[i
] = info
[i
] > 0;
8511 signal_cache_update (-1);
8512 target_pass_signals (signal_pass
);
8516 sig_print_header (void)
8518 printf_filtered (_("Signal Stop\tPrint\tPass "
8519 "to program\tDescription\n"));
8523 sig_print_info (enum gdb_signal oursig
)
8525 const char *name
= gdb_signal_to_name (oursig
);
8526 int name_padding
= 13 - strlen (name
);
8528 if (name_padding
<= 0)
8531 printf_filtered ("%s", name
);
8532 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8533 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8534 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8535 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8536 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8539 /* Specify how various signals in the inferior should be handled. */
8542 handle_command (const char *args
, int from_tty
)
8544 int digits
, wordlen
;
8545 int sigfirst
, siglast
;
8546 enum gdb_signal oursig
;
8551 error_no_arg (_("signal to handle"));
8554 /* Allocate and zero an array of flags for which signals to handle. */
8556 const size_t nsigs
= GDB_SIGNAL_LAST
;
8557 unsigned char sigs
[nsigs
] {};
8559 /* Break the command line up into args. */
8561 gdb_argv
built_argv (args
);
8563 /* Walk through the args, looking for signal oursigs, signal names, and
8564 actions. Signal numbers and signal names may be interspersed with
8565 actions, with the actions being performed for all signals cumulatively
8566 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8568 for (char *arg
: built_argv
)
8570 wordlen
= strlen (arg
);
8571 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8575 sigfirst
= siglast
= -1;
8577 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8579 /* Apply action to all signals except those used by the
8580 debugger. Silently skip those. */
8583 siglast
= nsigs
- 1;
8585 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8587 SET_SIGS (nsigs
, sigs
, signal_stop
);
8588 SET_SIGS (nsigs
, sigs
, signal_print
);
8590 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8592 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8594 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8596 SET_SIGS (nsigs
, sigs
, signal_print
);
8598 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8600 SET_SIGS (nsigs
, sigs
, signal_program
);
8602 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8604 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8606 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8608 SET_SIGS (nsigs
, sigs
, signal_program
);
8610 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8612 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8613 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8615 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8617 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8619 else if (digits
> 0)
8621 /* It is numeric. The numeric signal refers to our own
8622 internal signal numbering from target.h, not to host/target
8623 signal number. This is a feature; users really should be
8624 using symbolic names anyway, and the common ones like
8625 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8627 sigfirst
= siglast
= (int)
8628 gdb_signal_from_command (atoi (arg
));
8629 if (arg
[digits
] == '-')
8632 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8634 if (sigfirst
> siglast
)
8636 /* Bet he didn't figure we'd think of this case... */
8637 std::swap (sigfirst
, siglast
);
8642 oursig
= gdb_signal_from_name (arg
);
8643 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8645 sigfirst
= siglast
= (int) oursig
;
8649 /* Not a number and not a recognized flag word => complain. */
8650 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8654 /* If any signal numbers or symbol names were found, set flags for
8655 which signals to apply actions to. */
8657 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8659 switch ((enum gdb_signal
) signum
)
8661 case GDB_SIGNAL_TRAP
:
8662 case GDB_SIGNAL_INT
:
8663 if (!allsigs
&& !sigs
[signum
])
8665 if (query (_("%s is used by the debugger.\n\
8666 Are you sure you want to change it? "),
8667 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8672 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8676 case GDB_SIGNAL_DEFAULT
:
8677 case GDB_SIGNAL_UNKNOWN
:
8678 /* Make sure that "all" doesn't print these. */
8687 for (int signum
= 0; signum
< nsigs
; signum
++)
8690 signal_cache_update (-1);
8691 target_pass_signals (signal_pass
);
8692 target_program_signals (signal_program
);
8696 /* Show the results. */
8697 sig_print_header ();
8698 for (; signum
< nsigs
; signum
++)
8700 sig_print_info ((enum gdb_signal
) signum
);
8707 /* Complete the "handle" command. */
8710 handle_completer (struct cmd_list_element
*ignore
,
8711 completion_tracker
&tracker
,
8712 const char *text
, const char *word
)
8714 static const char * const keywords
[] =
8728 signal_completer (ignore
, tracker
, text
, word
);
8729 complete_on_enum (tracker
, keywords
, word
, word
);
8733 gdb_signal_from_command (int num
)
8735 if (num
>= 1 && num
<= 15)
8736 return (enum gdb_signal
) num
;
8737 error (_("Only signals 1-15 are valid as numeric signals.\n\
8738 Use \"info signals\" for a list of symbolic signals."));
8741 /* Print current contents of the tables set by the handle command.
8742 It is possible we should just be printing signals actually used
8743 by the current target (but for things to work right when switching
8744 targets, all signals should be in the signal tables). */
8747 info_signals_command (const char *signum_exp
, int from_tty
)
8749 enum gdb_signal oursig
;
8751 sig_print_header ();
8755 /* First see if this is a symbol name. */
8756 oursig
= gdb_signal_from_name (signum_exp
);
8757 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8759 /* No, try numeric. */
8761 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8763 sig_print_info (oursig
);
8767 printf_filtered ("\n");
8768 /* These ugly casts brought to you by the native VAX compiler. */
8769 for (oursig
= GDB_SIGNAL_FIRST
;
8770 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8771 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8775 if (oursig
!= GDB_SIGNAL_UNKNOWN
8776 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8777 sig_print_info (oursig
);
8780 printf_filtered (_("\nUse the \"handle\" command "
8781 "to change these tables.\n"));
8784 /* The $_siginfo convenience variable is a bit special. We don't know
8785 for sure the type of the value until we actually have a chance to
8786 fetch the data. The type can change depending on gdbarch, so it is
8787 also dependent on which thread you have selected.
8789 1. making $_siginfo be an internalvar that creates a new value on
8792 2. making the value of $_siginfo be an lval_computed value. */
8794 /* This function implements the lval_computed support for reading a
8798 siginfo_value_read (struct value
*v
)
8800 LONGEST transferred
;
8802 /* If we can access registers, so can we access $_siginfo. Likewise
8804 validate_registers_access ();
8807 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8809 value_contents_all_raw (v
),
8811 TYPE_LENGTH (value_type (v
)));
8813 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8814 error (_("Unable to read siginfo"));
8817 /* This function implements the lval_computed support for writing a
8821 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8823 LONGEST transferred
;
8825 /* If we can access registers, so can we access $_siginfo. Likewise
8827 validate_registers_access ();
8829 transferred
= target_write (current_top_target (),
8830 TARGET_OBJECT_SIGNAL_INFO
,
8832 value_contents_all_raw (fromval
),
8834 TYPE_LENGTH (value_type (fromval
)));
8836 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8837 error (_("Unable to write siginfo"));
8840 static const struct lval_funcs siginfo_value_funcs
=
8846 /* Return a new value with the correct type for the siginfo object of
8847 the current thread using architecture GDBARCH. Return a void value
8848 if there's no object available. */
8850 static struct value
*
8851 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8854 if (target_has_stack ()
8855 && inferior_ptid
!= null_ptid
8856 && gdbarch_get_siginfo_type_p (gdbarch
))
8858 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8860 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8863 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8867 /* infcall_suspend_state contains state about the program itself like its
8868 registers and any signal it received when it last stopped.
8869 This state must be restored regardless of how the inferior function call
8870 ends (either successfully, or after it hits a breakpoint or signal)
8871 if the program is to properly continue where it left off. */
8873 class infcall_suspend_state
8876 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8877 once the inferior function call has finished. */
8878 infcall_suspend_state (struct gdbarch
*gdbarch
,
8879 const struct thread_info
*tp
,
8880 struct regcache
*regcache
)
8881 : m_thread_suspend (tp
->suspend
),
8882 m_registers (new readonly_detached_regcache (*regcache
))
8884 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8886 if (gdbarch_get_siginfo_type_p (gdbarch
))
8888 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8889 size_t len
= TYPE_LENGTH (type
);
8891 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8893 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8894 siginfo_data
.get (), 0, len
) != len
)
8896 /* Errors ignored. */
8897 siginfo_data
.reset (nullptr);
8903 m_siginfo_gdbarch
= gdbarch
;
8904 m_siginfo_data
= std::move (siginfo_data
);
8908 /* Return a pointer to the stored register state. */
8910 readonly_detached_regcache
*registers () const
8912 return m_registers
.get ();
8915 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8917 void restore (struct gdbarch
*gdbarch
,
8918 struct thread_info
*tp
,
8919 struct regcache
*regcache
) const
8921 tp
->suspend
= m_thread_suspend
;
8923 if (m_siginfo_gdbarch
== gdbarch
)
8925 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8927 /* Errors ignored. */
8928 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8929 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8932 /* The inferior can be gone if the user types "print exit(0)"
8933 (and perhaps other times). */
8934 if (target_has_execution ())
8935 /* NB: The register write goes through to the target. */
8936 regcache
->restore (registers ());
8940 /* How the current thread stopped before the inferior function call was
8942 struct thread_suspend_state m_thread_suspend
;
8944 /* The registers before the inferior function call was executed. */
8945 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8947 /* Format of SIGINFO_DATA or NULL if it is not present. */
8948 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8950 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8951 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8952 content would be invalid. */
8953 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8956 infcall_suspend_state_up
8957 save_infcall_suspend_state ()
8959 struct thread_info
*tp
= inferior_thread ();
8960 struct regcache
*regcache
= get_current_regcache ();
8961 struct gdbarch
*gdbarch
= regcache
->arch ();
8963 infcall_suspend_state_up inf_state
8964 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8966 /* Having saved the current state, adjust the thread state, discarding
8967 any stop signal information. The stop signal is not useful when
8968 starting an inferior function call, and run_inferior_call will not use
8969 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8970 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8975 /* Restore inferior session state to INF_STATE. */
8978 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8980 struct thread_info
*tp
= inferior_thread ();
8981 struct regcache
*regcache
= get_current_regcache ();
8982 struct gdbarch
*gdbarch
= regcache
->arch ();
8984 inf_state
->restore (gdbarch
, tp
, regcache
);
8985 discard_infcall_suspend_state (inf_state
);
8989 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8994 readonly_detached_regcache
*
8995 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8997 return inf_state
->registers ();
9000 /* infcall_control_state contains state regarding gdb's control of the
9001 inferior itself like stepping control. It also contains session state like
9002 the user's currently selected frame. */
9004 struct infcall_control_state
9006 struct thread_control_state thread_control
;
9007 struct inferior_control_state inferior_control
;
9010 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9011 int stopped_by_random_signal
= 0;
9013 /* ID if the selected frame when the inferior function call was made. */
9014 struct frame_id selected_frame_id
{};
9017 /* Save all of the information associated with the inferior<==>gdb
9020 infcall_control_state_up
9021 save_infcall_control_state ()
9023 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9024 struct thread_info
*tp
= inferior_thread ();
9025 struct inferior
*inf
= current_inferior ();
9027 inf_status
->thread_control
= tp
->control
;
9028 inf_status
->inferior_control
= inf
->control
;
9030 tp
->control
.step_resume_breakpoint
= NULL
;
9031 tp
->control
.exception_resume_breakpoint
= NULL
;
9033 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9034 chain. If caller's caller is walking the chain, they'll be happier if we
9035 hand them back the original chain when restore_infcall_control_state is
9037 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9040 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9041 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9043 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9049 restore_selected_frame (const frame_id
&fid
)
9051 frame_info
*frame
= frame_find_by_id (fid
);
9053 /* If inf_status->selected_frame_id is NULL, there was no previously
9057 warning (_("Unable to restore previously selected frame."));
9061 select_frame (frame
);
9064 /* Restore inferior session state to INF_STATUS. */
9067 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9069 struct thread_info
*tp
= inferior_thread ();
9070 struct inferior
*inf
= current_inferior ();
9072 if (tp
->control
.step_resume_breakpoint
)
9073 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9075 if (tp
->control
.exception_resume_breakpoint
)
9076 tp
->control
.exception_resume_breakpoint
->disposition
9077 = disp_del_at_next_stop
;
9079 /* Handle the bpstat_copy of the chain. */
9080 bpstat_clear (&tp
->control
.stop_bpstat
);
9082 tp
->control
= inf_status
->thread_control
;
9083 inf
->control
= inf_status
->inferior_control
;
9086 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9087 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9089 if (target_has_stack ())
9091 /* The point of the try/catch is that if the stack is clobbered,
9092 walking the stack might encounter a garbage pointer and
9093 error() trying to dereference it. */
9096 restore_selected_frame (inf_status
->selected_frame_id
);
9098 catch (const gdb_exception_error
&ex
)
9100 exception_fprintf (gdb_stderr
, ex
,
9101 "Unable to restore previously selected frame:\n");
9102 /* Error in restoring the selected frame. Select the
9104 select_frame (get_current_frame ());
9112 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9114 if (inf_status
->thread_control
.step_resume_breakpoint
)
9115 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9116 = disp_del_at_next_stop
;
9118 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9119 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9120 = disp_del_at_next_stop
;
9122 /* See save_infcall_control_state for info on stop_bpstat. */
9123 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9131 clear_exit_convenience_vars (void)
9133 clear_internalvar (lookup_internalvar ("_exitsignal"));
9134 clear_internalvar (lookup_internalvar ("_exitcode"));
9138 /* User interface for reverse debugging:
9139 Set exec-direction / show exec-direction commands
9140 (returns error unless target implements to_set_exec_direction method). */
9142 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9143 static const char exec_forward
[] = "forward";
9144 static const char exec_reverse
[] = "reverse";
9145 static const char *exec_direction
= exec_forward
;
9146 static const char *const exec_direction_names
[] = {
9153 set_exec_direction_func (const char *args
, int from_tty
,
9154 struct cmd_list_element
*cmd
)
9156 if (target_can_execute_reverse ())
9158 if (!strcmp (exec_direction
, exec_forward
))
9159 execution_direction
= EXEC_FORWARD
;
9160 else if (!strcmp (exec_direction
, exec_reverse
))
9161 execution_direction
= EXEC_REVERSE
;
9165 exec_direction
= exec_forward
;
9166 error (_("Target does not support this operation."));
9171 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9172 struct cmd_list_element
*cmd
, const char *value
)
9174 switch (execution_direction
) {
9176 fprintf_filtered (out
, _("Forward.\n"));
9179 fprintf_filtered (out
, _("Reverse.\n"));
9182 internal_error (__FILE__
, __LINE__
,
9183 _("bogus execution_direction value: %d"),
9184 (int) execution_direction
);
9189 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9190 struct cmd_list_element
*c
, const char *value
)
9192 fprintf_filtered (file
, _("Resuming the execution of threads "
9193 "of all processes is %s.\n"), value
);
9196 /* Implementation of `siginfo' variable. */
9198 static const struct internalvar_funcs siginfo_funcs
=
9205 /* Callback for infrun's target events source. This is marked when a
9206 thread has a pending status to process. */
9209 infrun_async_inferior_event_handler (gdb_client_data data
)
9211 inferior_event_handler (INF_REG_EVENT
);
9218 /* Verify that when two threads with the same ptid exist (from two different
9219 targets) and one of them changes ptid, we only update inferior_ptid if
9220 it is appropriate. */
9223 infrun_thread_ptid_changed ()
9225 gdbarch
*arch
= current_inferior ()->gdbarch
;
9227 /* The thread which inferior_ptid represents changes ptid. */
9229 scoped_restore_current_pspace_and_thread restore
;
9231 scoped_mock_context
<test_target_ops
> target1 (arch
);
9232 scoped_mock_context
<test_target_ops
> target2 (arch
);
9233 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9235 ptid_t
old_ptid (111, 222);
9236 ptid_t
new_ptid (111, 333);
9238 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9239 target1
.mock_thread
.ptid
= old_ptid
;
9240 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9241 target2
.mock_thread
.ptid
= old_ptid
;
9243 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9244 set_current_inferior (&target1
.mock_inferior
);
9246 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9248 gdb_assert (inferior_ptid
== new_ptid
);
9251 /* A thread with the same ptid as inferior_ptid, but from another target,
9254 scoped_restore_current_pspace_and_thread restore
;
9256 scoped_mock_context
<test_target_ops
> target1 (arch
);
9257 scoped_mock_context
<test_target_ops
> target2 (arch
);
9258 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9260 ptid_t
old_ptid (111, 222);
9261 ptid_t
new_ptid (111, 333);
9263 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9264 target1
.mock_thread
.ptid
= old_ptid
;
9265 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9266 target2
.mock_thread
.ptid
= old_ptid
;
9268 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9269 set_current_inferior (&target2
.mock_inferior
);
9271 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9273 gdb_assert (inferior_ptid
== old_ptid
);
9277 } /* namespace selftests */
9279 #endif /* GDB_SELF_TEST */
9281 void _initialize_infrun ();
9283 _initialize_infrun ()
9285 struct cmd_list_element
*c
;
9287 /* Register extra event sources in the event loop. */
9288 infrun_async_inferior_event_token
9289 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9292 add_info ("signals", info_signals_command
, _("\
9293 What debugger does when program gets various signals.\n\
9294 Specify a signal as argument to print info on that signal only."));
9295 add_info_alias ("handle", "signals", 0);
9297 c
= add_com ("handle", class_run
, handle_command
, _("\
9298 Specify how to handle signals.\n\
9299 Usage: handle SIGNAL [ACTIONS]\n\
9300 Args are signals and actions to apply to those signals.\n\
9301 If no actions are specified, the current settings for the specified signals\n\
9302 will be displayed instead.\n\
9304 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9305 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9306 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9307 The special arg \"all\" is recognized to mean all signals except those\n\
9308 used by the debugger, typically SIGTRAP and SIGINT.\n\
9310 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9311 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9312 Stop means reenter debugger if this signal happens (implies print).\n\
9313 Print means print a message if this signal happens.\n\
9314 Pass means let program see this signal; otherwise program doesn't know.\n\
9315 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9316 Pass and Stop may be combined.\n\
9318 Multiple signals may be specified. Signal numbers and signal names\n\
9319 may be interspersed with actions, with the actions being performed for\n\
9320 all signals cumulatively specified."));
9321 set_cmd_completer (c
, handle_completer
);
9324 stop_command
= add_cmd ("stop", class_obscure
,
9325 not_just_help_class_command
, _("\
9326 There is no `stop' command, but you can set a hook on `stop'.\n\
9327 This allows you to set a list of commands to be run each time execution\n\
9328 of the program stops."), &cmdlist
);
9330 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9331 Set inferior debugging."), _("\
9332 Show inferior debugging."), _("\
9333 When non-zero, inferior specific debugging is enabled."),
9336 &setdebuglist
, &showdebuglist
);
9338 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9339 &debug_displaced
, _("\
9340 Set displaced stepping debugging."), _("\
9341 Show displaced stepping debugging."), _("\
9342 When non-zero, displaced stepping specific debugging is enabled."),
9344 show_debug_displaced
,
9345 &setdebuglist
, &showdebuglist
);
9347 add_setshow_boolean_cmd ("non-stop", no_class
,
9349 Set whether gdb controls the inferior in non-stop mode."), _("\
9350 Show whether gdb controls the inferior in non-stop mode."), _("\
9351 When debugging a multi-threaded program and this setting is\n\
9352 off (the default, also called all-stop mode), when one thread stops\n\
9353 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9354 all other threads in the program while you interact with the thread of\n\
9355 interest. When you continue or step a thread, you can allow the other\n\
9356 threads to run, or have them remain stopped, but while you inspect any\n\
9357 thread's state, all threads stop.\n\
9359 In non-stop mode, when one thread stops, other threads can continue\n\
9360 to run freely. You'll be able to step each thread independently,\n\
9361 leave it stopped or free to run as needed."),
9367 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9370 signal_print
[i
] = 1;
9371 signal_program
[i
] = 1;
9372 signal_catch
[i
] = 0;
9375 /* Signals caused by debugger's own actions should not be given to
9376 the program afterwards.
9378 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9379 explicitly specifies that it should be delivered to the target
9380 program. Typically, that would occur when a user is debugging a
9381 target monitor on a simulator: the target monitor sets a
9382 breakpoint; the simulator encounters this breakpoint and halts
9383 the simulation handing control to GDB; GDB, noting that the stop
9384 address doesn't map to any known breakpoint, returns control back
9385 to the simulator; the simulator then delivers the hardware
9386 equivalent of a GDB_SIGNAL_TRAP to the program being
9388 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9389 signal_program
[GDB_SIGNAL_INT
] = 0;
9391 /* Signals that are not errors should not normally enter the debugger. */
9392 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9393 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9394 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9395 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9396 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9397 signal_print
[GDB_SIGNAL_PROF
] = 0;
9398 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9399 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9400 signal_stop
[GDB_SIGNAL_IO
] = 0;
9401 signal_print
[GDB_SIGNAL_IO
] = 0;
9402 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9403 signal_print
[GDB_SIGNAL_POLL
] = 0;
9404 signal_stop
[GDB_SIGNAL_URG
] = 0;
9405 signal_print
[GDB_SIGNAL_URG
] = 0;
9406 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9407 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9408 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9409 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9411 /* These signals are used internally by user-level thread
9412 implementations. (See signal(5) on Solaris.) Like the above
9413 signals, a healthy program receives and handles them as part of
9414 its normal operation. */
9415 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9416 signal_print
[GDB_SIGNAL_LWP
] = 0;
9417 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9418 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9419 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9420 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9421 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9422 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9424 /* Update cached state. */
9425 signal_cache_update (-1);
9427 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9428 &stop_on_solib_events
, _("\
9429 Set stopping for shared library events."), _("\
9430 Show stopping for shared library events."), _("\
9431 If nonzero, gdb will give control to the user when the dynamic linker\n\
9432 notifies gdb of shared library events. The most common event of interest\n\
9433 to the user would be loading/unloading of a new library."),
9434 set_stop_on_solib_events
,
9435 show_stop_on_solib_events
,
9436 &setlist
, &showlist
);
9438 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9439 follow_fork_mode_kind_names
,
9440 &follow_fork_mode_string
, _("\
9441 Set debugger response to a program call of fork or vfork."), _("\
9442 Show debugger response to a program call of fork or vfork."), _("\
9443 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9444 parent - the original process is debugged after a fork\n\
9445 child - the new process is debugged after a fork\n\
9446 The unfollowed process will continue to run.\n\
9447 By default, the debugger will follow the parent process."),
9449 show_follow_fork_mode_string
,
9450 &setlist
, &showlist
);
9452 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9453 follow_exec_mode_names
,
9454 &follow_exec_mode_string
, _("\
9455 Set debugger response to a program call of exec."), _("\
9456 Show debugger response to a program call of exec."), _("\
9457 An exec call replaces the program image of a process.\n\
9459 follow-exec-mode can be:\n\
9461 new - the debugger creates a new inferior and rebinds the process\n\
9462 to this new inferior. The program the process was running before\n\
9463 the exec call can be restarted afterwards by restarting the original\n\
9466 same - the debugger keeps the process bound to the same inferior.\n\
9467 The new executable image replaces the previous executable loaded in\n\
9468 the inferior. Restarting the inferior after the exec call restarts\n\
9469 the executable the process was running after the exec call.\n\
9471 By default, the debugger will use the same inferior."),
9473 show_follow_exec_mode_string
,
9474 &setlist
, &showlist
);
9476 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9477 scheduler_enums
, &scheduler_mode
, _("\
9478 Set mode for locking scheduler during execution."), _("\
9479 Show mode for locking scheduler during execution."), _("\
9480 off == no locking (threads may preempt at any time)\n\
9481 on == full locking (no thread except the current thread may run)\n\
9482 This applies to both normal execution and replay mode.\n\
9483 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9484 In this mode, other threads may run during other commands.\n\
9485 This applies to both normal execution and replay mode.\n\
9486 replay == scheduler locked in replay mode and unlocked during normal execution."),
9487 set_schedlock_func
, /* traps on target vector */
9488 show_scheduler_mode
,
9489 &setlist
, &showlist
);
9491 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9492 Set mode for resuming threads of all processes."), _("\
9493 Show mode for resuming threads of all processes."), _("\
9494 When on, execution commands (such as 'continue' or 'next') resume all\n\
9495 threads of all processes. When off (which is the default), execution\n\
9496 commands only resume the threads of the current process. The set of\n\
9497 threads that are resumed is further refined by the scheduler-locking\n\
9498 mode (see help set scheduler-locking)."),
9500 show_schedule_multiple
,
9501 &setlist
, &showlist
);
9503 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9504 Set mode of the step operation."), _("\
9505 Show mode of the step operation."), _("\
9506 When set, doing a step over a function without debug line information\n\
9507 will stop at the first instruction of that function. Otherwise, the\n\
9508 function is skipped and the step command stops at a different source line."),
9510 show_step_stop_if_no_debug
,
9511 &setlist
, &showlist
);
9513 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9514 &can_use_displaced_stepping
, _("\
9515 Set debugger's willingness to use displaced stepping."), _("\
9516 Show debugger's willingness to use displaced stepping."), _("\
9517 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9518 supported by the target architecture. If off, gdb will not use displaced\n\
9519 stepping to step over breakpoints, even if such is supported by the target\n\
9520 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9521 if the target architecture supports it and non-stop mode is active, but will not\n\
9522 use it in all-stop mode (see help set non-stop)."),
9524 show_can_use_displaced_stepping
,
9525 &setlist
, &showlist
);
9527 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9528 &exec_direction
, _("Set direction of execution.\n\
9529 Options are 'forward' or 'reverse'."),
9530 _("Show direction of execution (forward/reverse)."),
9531 _("Tells gdb whether to execute forward or backward."),
9532 set_exec_direction_func
, show_exec_direction_func
,
9533 &setlist
, &showlist
);
9535 /* Set/show detach-on-fork: user-settable mode. */
9537 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9538 Set whether gdb will detach the child of a fork."), _("\
9539 Show whether gdb will detach the child of a fork."), _("\
9540 Tells gdb whether to detach the child of a fork."),
9541 NULL
, NULL
, &setlist
, &showlist
);
9543 /* Set/show disable address space randomization mode. */
9545 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9546 &disable_randomization
, _("\
9547 Set disabling of debuggee's virtual address space randomization."), _("\
9548 Show disabling of debuggee's virtual address space randomization."), _("\
9549 When this mode is on (which is the default), randomization of the virtual\n\
9550 address space is disabled. Standalone programs run with the randomization\n\
9551 enabled by default on some platforms."),
9552 &set_disable_randomization
,
9553 &show_disable_randomization
,
9554 &setlist
, &showlist
);
9556 /* ptid initializations */
9557 inferior_ptid
= null_ptid
;
9558 target_last_wait_ptid
= minus_one_ptid
;
9560 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9561 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9562 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9563 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9565 /* Explicitly create without lookup, since that tries to create a
9566 value with a void typed value, and when we get here, gdbarch
9567 isn't initialized yet. At this point, we're quite sure there
9568 isn't another convenience variable of the same name. */
9569 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9571 add_setshow_boolean_cmd ("observer", no_class
,
9572 &observer_mode_1
, _("\
9573 Set whether gdb controls the inferior in observer mode."), _("\
9574 Show whether gdb controls the inferior in observer mode."), _("\
9575 In observer mode, GDB can get data from the inferior, but not\n\
9576 affect its execution. Registers and memory may not be changed,\n\
9577 breakpoints may not be set, and the program cannot be interrupted\n\
9585 selftests::register_test ("infrun_thread_ptid_changed",
9586 selftests::infrun_thread_ptid_changed
);