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 bool 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 bool 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 /* True after stop if current stack frame should be printed. */
385 static bool 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 (inf
);
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 inferior INF. */
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 is doing a displaced step. */
1506 displaced_step_in_progress_thread (thread_info
*thread
)
1508 gdb_assert (thread
!= NULL
);
1510 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1513 /* Return true if INF has a thread doing a displaced step. */
1516 displaced_step_in_progress (inferior
*inf
)
1518 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1521 /* If inferior is in displaced stepping, and ADDR equals to starting address
1522 of copy area, return corresponding displaced_step_closure. Otherwise,
1525 struct displaced_step_closure
*
1526 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1528 displaced_step_inferior_state
*displaced
1529 = get_displaced_stepping_state (current_inferior ());
1531 /* If checking the mode of displaced instruction in copy area. */
1532 if (displaced
->step_thread
!= nullptr
1533 && displaced
->step_copy
== addr
)
1534 return displaced
->step_closure
.get ();
1540 infrun_inferior_exit (struct inferior
*inf
)
1542 inf
->displaced_step_state
.reset ();
1545 /* If ON, and the architecture supports it, GDB will use displaced
1546 stepping to step over breakpoints. If OFF, or if the architecture
1547 doesn't support it, GDB will instead use the traditional
1548 hold-and-step approach. If AUTO (which is the default), GDB will
1549 decide which technique to use to step over breakpoints depending on
1550 whether the target works in a non-stop way (see use_displaced_stepping). */
1552 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1555 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1556 struct cmd_list_element
*c
,
1559 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1560 fprintf_filtered (file
,
1561 _("Debugger's willingness to use displaced stepping "
1562 "to step over breakpoints is %s (currently %s).\n"),
1563 value
, target_is_non_stop_p () ? "on" : "off");
1565 fprintf_filtered (file
,
1566 _("Debugger's willingness to use displaced stepping "
1567 "to step over breakpoints is %s.\n"), value
);
1570 /* Return true if the gdbarch implements the required methods to use
1571 displaced stepping. */
1574 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1576 /* Only check for the presence of step_copy_insn. Other required methods
1577 are checked by the gdbarch validation. */
1578 return gdbarch_displaced_step_copy_insn_p (arch
);
1581 /* Return non-zero if displaced stepping can/should be used to step
1582 over breakpoints of thread TP. */
1585 use_displaced_stepping (thread_info
*tp
)
1587 /* If the user disabled it explicitly, don't use displaced stepping. */
1588 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1591 /* If "auto", only use displaced stepping if the target operates in a non-stop
1593 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1594 && !target_is_non_stop_p ())
1597 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1599 /* If the architecture doesn't implement displaced stepping, don't use
1601 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1604 /* If recording, don't use displaced stepping. */
1605 if (find_record_target () != nullptr)
1608 displaced_step_inferior_state
*displaced_state
1609 = get_displaced_stepping_state (tp
->inf
);
1611 /* If displaced stepping failed before for this inferior, don't bother trying
1613 if (displaced_state
->failed_before
)
1619 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1622 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1624 displaced
->reset ();
1627 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1628 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1630 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1632 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1634 displaced_step_dump_bytes (struct ui_file
*file
,
1635 const gdb_byte
*buf
,
1640 for (i
= 0; i
< len
; i
++)
1641 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1642 fputs_unfiltered ("\n", file
);
1645 /* Prepare to single-step, using displaced stepping.
1647 Note that we cannot use displaced stepping when we have a signal to
1648 deliver. If we have a signal to deliver and an instruction to step
1649 over, then after the step, there will be no indication from the
1650 target whether the thread entered a signal handler or ignored the
1651 signal and stepped over the instruction successfully --- both cases
1652 result in a simple SIGTRAP. In the first case we mustn't do a
1653 fixup, and in the second case we must --- but we can't tell which.
1654 Comments in the code for 'random signals' in handle_inferior_event
1655 explain how we handle this case instead.
1657 Returns 1 if preparing was successful -- this thread is going to be
1658 stepped now; 0 if displaced stepping this thread got queued; or -1
1659 if this instruction can't be displaced stepped. */
1662 displaced_step_prepare_throw (thread_info
*tp
)
1664 regcache
*regcache
= get_thread_regcache (tp
);
1665 struct gdbarch
*gdbarch
= regcache
->arch ();
1666 const address_space
*aspace
= regcache
->aspace ();
1667 CORE_ADDR original
, copy
;
1671 /* We should never reach this function if the architecture does not
1672 support displaced stepping. */
1673 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1675 /* Nor if the thread isn't meant to step over a breakpoint. */
1676 gdb_assert (tp
->control
.trap_expected
);
1678 /* Disable range stepping while executing in the scratch pad. We
1679 want a single-step even if executing the displaced instruction in
1680 the scratch buffer lands within the stepping range (e.g., a
1682 tp
->control
.may_range_step
= 0;
1684 /* We have to displaced step one thread at a time, as we only have
1685 access to a single scratch space per inferior. */
1687 displaced_step_inferior_state
*displaced
1688 = get_displaced_stepping_state (tp
->inf
);
1690 if (displaced
->step_thread
!= nullptr)
1692 /* Already waiting for a displaced step to finish. Defer this
1693 request and place in queue. */
1695 if (debug_displaced
)
1696 fprintf_unfiltered (gdb_stdlog
,
1697 "displaced: deferring step of %s\n",
1698 target_pid_to_str (tp
->ptid
).c_str ());
1700 thread_step_over_chain_enqueue (tp
);
1705 if (debug_displaced
)
1706 fprintf_unfiltered (gdb_stdlog
,
1707 "displaced: stepping %s now\n",
1708 target_pid_to_str (tp
->ptid
).c_str ());
1711 displaced_step_reset (displaced
);
1713 scoped_restore_current_thread restore_thread
;
1715 switch_to_thread (tp
);
1717 original
= regcache_read_pc (regcache
);
1719 copy
= gdbarch_displaced_step_location (gdbarch
);
1720 len
= gdbarch_max_insn_length (gdbarch
);
1722 if (breakpoint_in_range_p (aspace
, copy
, len
))
1724 /* There's a breakpoint set in the scratch pad location range
1725 (which is usually around the entry point). We'd either
1726 install it before resuming, which would overwrite/corrupt the
1727 scratch pad, or if it was already inserted, this displaced
1728 step would overwrite it. The latter is OK in the sense that
1729 we already assume that no thread is going to execute the code
1730 in the scratch pad range (after initial startup) anyway, but
1731 the former is unacceptable. Simply punt and fallback to
1732 stepping over this breakpoint in-line. */
1733 if (debug_displaced
)
1735 fprintf_unfiltered (gdb_stdlog
,
1736 "displaced: breakpoint set in scratch pad. "
1737 "Stepping over breakpoint in-line instead.\n");
1743 /* Save the original contents of the copy area. */
1744 displaced
->step_saved_copy
.resize (len
);
1745 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1747 throw_error (MEMORY_ERROR
,
1748 _("Error accessing memory address %s (%s) for "
1749 "displaced-stepping scratch space."),
1750 paddress (gdbarch
, copy
), safe_strerror (status
));
1751 if (debug_displaced
)
1753 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1754 paddress (gdbarch
, copy
));
1755 displaced_step_dump_bytes (gdb_stdlog
,
1756 displaced
->step_saved_copy
.data (),
1760 displaced
->step_closure
1761 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1762 if (displaced
->step_closure
== NULL
)
1764 /* The architecture doesn't know how or want to displaced step
1765 this instruction or instruction sequence. Fallback to
1766 stepping over the breakpoint in-line. */
1770 /* Save the information we need to fix things up if the step
1772 displaced
->step_thread
= tp
;
1773 displaced
->step_gdbarch
= gdbarch
;
1774 displaced
->step_original
= original
;
1775 displaced
->step_copy
= copy
;
1778 displaced_step_reset_cleanup
cleanup (displaced
);
1780 /* Resume execution at the copy. */
1781 regcache_write_pc (regcache
, copy
);
1786 if (debug_displaced
)
1787 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1788 paddress (gdbarch
, copy
));
1793 /* Wrapper for displaced_step_prepare_throw that disabled further
1794 attempts at displaced stepping if we get a memory error. */
1797 displaced_step_prepare (thread_info
*thread
)
1803 prepared
= displaced_step_prepare_throw (thread
);
1805 catch (const gdb_exception_error
&ex
)
1807 struct displaced_step_inferior_state
*displaced_state
;
1809 if (ex
.error
!= MEMORY_ERROR
1810 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1813 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1816 /* Be verbose if "set displaced-stepping" is "on", silent if
1818 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1820 warning (_("disabling displaced stepping: %s"),
1824 /* Disable further displaced stepping attempts. */
1826 = get_displaced_stepping_state (thread
->inf
);
1827 displaced_state
->failed_before
= 1;
1834 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1835 const gdb_byte
*myaddr
, int len
)
1837 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1839 inferior_ptid
= ptid
;
1840 write_memory (memaddr
, myaddr
, len
);
1843 /* Restore the contents of the copy area for thread PTID. */
1846 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1849 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1851 write_memory_ptid (ptid
, displaced
->step_copy
,
1852 displaced
->step_saved_copy
.data (), len
);
1853 if (debug_displaced
)
1854 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1855 target_pid_to_str (ptid
).c_str (),
1856 paddress (displaced
->step_gdbarch
,
1857 displaced
->step_copy
));
1860 /* If we displaced stepped an instruction successfully, adjust
1861 registers and memory to yield the same effect the instruction would
1862 have had if we had executed it at its original address, and return
1863 1. If the instruction didn't complete, relocate the PC and return
1864 -1. If the thread wasn't displaced stepping, return 0. */
1867 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1869 struct displaced_step_inferior_state
*displaced
1870 = get_displaced_stepping_state (event_thread
->inf
);
1873 /* Was this event for the thread we displaced? */
1874 if (displaced
->step_thread
!= event_thread
)
1877 /* Fixup may need to read memory/registers. Switch to the thread
1878 that we're fixing up. Also, target_stopped_by_watchpoint checks
1879 the current thread, and displaced_step_restore performs ptid-dependent
1880 memory accesses using current_inferior() and current_top_target(). */
1881 switch_to_thread (event_thread
);
1883 displaced_step_reset_cleanup
cleanup (displaced
);
1885 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1887 /* Did the instruction complete successfully? */
1888 if (signal
== GDB_SIGNAL_TRAP
1889 && !(target_stopped_by_watchpoint ()
1890 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1891 || target_have_steppable_watchpoint ())))
1893 /* Fix up the resulting state. */
1894 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1895 displaced
->step_closure
.get (),
1896 displaced
->step_original
,
1897 displaced
->step_copy
,
1898 get_thread_regcache (displaced
->step_thread
));
1903 /* Since the instruction didn't complete, all we can do is
1905 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1906 CORE_ADDR pc
= regcache_read_pc (regcache
);
1908 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1909 regcache_write_pc (regcache
, pc
);
1916 /* Data to be passed around while handling an event. This data is
1917 discarded between events. */
1918 struct execution_control_state
1920 process_stratum_target
*target
;
1922 /* The thread that got the event, if this was a thread event; NULL
1924 struct thread_info
*event_thread
;
1926 struct target_waitstatus ws
;
1927 int stop_func_filled_in
;
1928 CORE_ADDR stop_func_start
;
1929 CORE_ADDR stop_func_end
;
1930 const char *stop_func_name
;
1933 /* True if the event thread hit the single-step breakpoint of
1934 another thread. Thus the event doesn't cause a stop, the thread
1935 needs to be single-stepped past the single-step breakpoint before
1936 we can switch back to the original stepping thread. */
1937 int hit_singlestep_breakpoint
;
1940 /* Clear ECS and set it to point at TP. */
1943 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1945 memset (ecs
, 0, sizeof (*ecs
));
1946 ecs
->event_thread
= tp
;
1947 ecs
->ptid
= tp
->ptid
;
1950 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1951 static void prepare_to_wait (struct execution_control_state
*ecs
);
1952 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1953 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1955 /* Are there any pending step-over requests? If so, run all we can
1956 now and return true. Otherwise, return false. */
1959 start_step_over (void)
1961 struct thread_info
*tp
, *next
;
1963 /* Don't start a new step-over if we already have an in-line
1964 step-over operation ongoing. */
1965 if (step_over_info_valid_p ())
1968 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1970 struct execution_control_state ecss
;
1971 struct execution_control_state
*ecs
= &ecss
;
1972 step_over_what step_what
;
1973 int must_be_in_line
;
1975 gdb_assert (!tp
->stop_requested
);
1977 next
= thread_step_over_chain_next (tp
);
1979 /* If this inferior already has a displaced step in process,
1980 don't start a new one. */
1981 if (displaced_step_in_progress (tp
->inf
))
1984 step_what
= thread_still_needs_step_over (tp
);
1985 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1986 || ((step_what
& STEP_OVER_BREAKPOINT
)
1987 && !use_displaced_stepping (tp
)));
1989 /* We currently stop all threads of all processes to step-over
1990 in-line. If we need to start a new in-line step-over, let
1991 any pending displaced steps finish first. */
1992 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1995 thread_step_over_chain_remove (tp
);
1997 if (step_over_queue_head
== NULL
)
1998 infrun_debug_printf ("step-over queue now empty");
2000 if (tp
->control
.trap_expected
2004 internal_error (__FILE__
, __LINE__
,
2005 "[%s] has inconsistent state: "
2006 "trap_expected=%d, resumed=%d, executing=%d\n",
2007 target_pid_to_str (tp
->ptid
).c_str (),
2008 tp
->control
.trap_expected
,
2013 infrun_debug_printf ("resuming [%s] for step-over",
2014 target_pid_to_str (tp
->ptid
).c_str ());
2016 /* keep_going_pass_signal skips the step-over if the breakpoint
2017 is no longer inserted. In all-stop, we want to keep looking
2018 for a thread that needs a step-over instead of resuming TP,
2019 because we wouldn't be able to resume anything else until the
2020 target stops again. In non-stop, the resume always resumes
2021 only TP, so it's OK to let the thread resume freely. */
2022 if (!target_is_non_stop_p () && !step_what
)
2025 switch_to_thread (tp
);
2026 reset_ecs (ecs
, tp
);
2027 keep_going_pass_signal (ecs
);
2029 if (!ecs
->wait_some_more
)
2030 error (_("Command aborted."));
2032 gdb_assert (tp
->resumed
);
2034 /* If we started a new in-line step-over, we're done. */
2035 if (step_over_info_valid_p ())
2037 gdb_assert (tp
->control
.trap_expected
);
2041 if (!target_is_non_stop_p ())
2043 /* On all-stop, shouldn't have resumed unless we needed a
2045 gdb_assert (tp
->control
.trap_expected
2046 || tp
->step_after_step_resume_breakpoint
);
2048 /* With remote targets (at least), in all-stop, we can't
2049 issue any further remote commands until the program stops
2054 /* Either the thread no longer needed a step-over, or a new
2055 displaced stepping sequence started. Even in the latter
2056 case, continue looking. Maybe we can also start another
2057 displaced step on a thread of other process. */
2063 /* Update global variables holding ptids to hold NEW_PTID if they were
2064 holding OLD_PTID. */
2066 infrun_thread_ptid_changed (process_stratum_target
*target
,
2067 ptid_t old_ptid
, ptid_t new_ptid
)
2069 if (inferior_ptid
== old_ptid
2070 && current_inferior ()->process_target () == target
)
2071 inferior_ptid
= new_ptid
;
2076 static const char schedlock_off
[] = "off";
2077 static const char schedlock_on
[] = "on";
2078 static const char schedlock_step
[] = "step";
2079 static const char schedlock_replay
[] = "replay";
2080 static const char *const scheduler_enums
[] = {
2087 static const char *scheduler_mode
= schedlock_replay
;
2089 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2090 struct cmd_list_element
*c
, const char *value
)
2092 fprintf_filtered (file
,
2093 _("Mode for locking scheduler "
2094 "during execution is \"%s\".\n"),
2099 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2101 if (!target_can_lock_scheduler ())
2103 scheduler_mode
= schedlock_off
;
2104 error (_("Target '%s' cannot support this command."), target_shortname
);
2108 /* True if execution commands resume all threads of all processes by
2109 default; otherwise, resume only threads of the current inferior
2111 bool sched_multi
= false;
2113 /* Try to setup for software single stepping over the specified location.
2114 Return true if target_resume() should use hardware single step.
2116 GDBARCH the current gdbarch.
2117 PC the location to step over. */
2120 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2122 bool hw_step
= true;
2124 if (execution_direction
== EXEC_FORWARD
2125 && gdbarch_software_single_step_p (gdbarch
))
2126 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2134 user_visible_resume_ptid (int step
)
2140 /* With non-stop mode on, threads are always handled
2142 resume_ptid
= inferior_ptid
;
2144 else if ((scheduler_mode
== schedlock_on
)
2145 || (scheduler_mode
== schedlock_step
&& step
))
2147 /* User-settable 'scheduler' mode requires solo thread
2149 resume_ptid
= inferior_ptid
;
2151 else if ((scheduler_mode
== schedlock_replay
)
2152 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2154 /* User-settable 'scheduler' mode requires solo thread resume in replay
2156 resume_ptid
= inferior_ptid
;
2158 else if (!sched_multi
&& target_supports_multi_process ())
2160 /* Resume all threads of the current process (and none of other
2162 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2166 /* Resume all threads of all processes. */
2167 resume_ptid
= RESUME_ALL
;
2175 process_stratum_target
*
2176 user_visible_resume_target (ptid_t resume_ptid
)
2178 return (resume_ptid
== minus_one_ptid
&& sched_multi
2180 : current_inferior ()->process_target ());
2183 /* Return a ptid representing the set of threads that we will resume,
2184 in the perspective of the target, assuming run control handling
2185 does not require leaving some threads stopped (e.g., stepping past
2186 breakpoint). USER_STEP indicates whether we're about to start the
2187 target for a stepping command. */
2190 internal_resume_ptid (int user_step
)
2192 /* In non-stop, we always control threads individually. Note that
2193 the target may always work in non-stop mode even with "set
2194 non-stop off", in which case user_visible_resume_ptid could
2195 return a wildcard ptid. */
2196 if (target_is_non_stop_p ())
2197 return inferior_ptid
;
2199 return user_visible_resume_ptid (user_step
);
2202 /* Wrapper for target_resume, that handles infrun-specific
2206 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2208 struct thread_info
*tp
= inferior_thread ();
2210 gdb_assert (!tp
->stop_requested
);
2212 /* Install inferior's terminal modes. */
2213 target_terminal::inferior ();
2215 /* Avoid confusing the next resume, if the next stop/resume
2216 happens to apply to another thread. */
2217 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2219 /* Advise target which signals may be handled silently.
2221 If we have removed breakpoints because we are stepping over one
2222 in-line (in any thread), we need to receive all signals to avoid
2223 accidentally skipping a breakpoint during execution of a signal
2226 Likewise if we're displaced stepping, otherwise a trap for a
2227 breakpoint in a signal handler might be confused with the
2228 displaced step finishing. We don't make the displaced_step_fixup
2229 step distinguish the cases instead, because:
2231 - a backtrace while stopped in the signal handler would show the
2232 scratch pad as frame older than the signal handler, instead of
2233 the real mainline code.
2235 - when the thread is later resumed, the signal handler would
2236 return to the scratch pad area, which would no longer be
2238 if (step_over_info_valid_p ()
2239 || displaced_step_in_progress (tp
->inf
))
2240 target_pass_signals ({});
2242 target_pass_signals (signal_pass
);
2244 target_resume (resume_ptid
, step
, sig
);
2246 target_commit_resume ();
2248 if (target_can_async_p ())
2252 /* Resume the inferior. SIG is the signal to give the inferior
2253 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2254 call 'resume', which handles exceptions. */
2257 resume_1 (enum gdb_signal sig
)
2259 struct regcache
*regcache
= get_current_regcache ();
2260 struct gdbarch
*gdbarch
= regcache
->arch ();
2261 struct thread_info
*tp
= inferior_thread ();
2262 const address_space
*aspace
= regcache
->aspace ();
2264 /* This represents the user's step vs continue request. When
2265 deciding whether "set scheduler-locking step" applies, it's the
2266 user's intention that counts. */
2267 const int user_step
= tp
->control
.stepping_command
;
2268 /* This represents what we'll actually request the target to do.
2269 This can decay from a step to a continue, if e.g., we need to
2270 implement single-stepping with breakpoints (software
2274 gdb_assert (!tp
->stop_requested
);
2275 gdb_assert (!thread_is_in_step_over_chain (tp
));
2277 if (tp
->suspend
.waitstatus_pending_p
)
2280 ("thread %s has pending wait "
2281 "status %s (currently_stepping=%d).",
2282 target_pid_to_str (tp
->ptid
).c_str (),
2283 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2284 currently_stepping (tp
));
2286 tp
->inf
->process_target ()->threads_executing
= true;
2289 /* FIXME: What should we do if we are supposed to resume this
2290 thread with a signal? Maybe we should maintain a queue of
2291 pending signals to deliver. */
2292 if (sig
!= GDB_SIGNAL_0
)
2294 warning (_("Couldn't deliver signal %s to %s."),
2295 gdb_signal_to_name (sig
),
2296 target_pid_to_str (tp
->ptid
).c_str ());
2299 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2301 if (target_can_async_p ())
2304 /* Tell the event loop we have an event to process. */
2305 mark_async_event_handler (infrun_async_inferior_event_token
);
2310 tp
->stepped_breakpoint
= 0;
2312 /* Depends on stepped_breakpoint. */
2313 step
= currently_stepping (tp
);
2315 if (current_inferior ()->waiting_for_vfork_done
)
2317 /* Don't try to single-step a vfork parent that is waiting for
2318 the child to get out of the shared memory region (by exec'ing
2319 or exiting). This is particularly important on software
2320 single-step archs, as the child process would trip on the
2321 software single step breakpoint inserted for the parent
2322 process. Since the parent will not actually execute any
2323 instruction until the child is out of the shared region (such
2324 are vfork's semantics), it is safe to simply continue it.
2325 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2326 the parent, and tell it to `keep_going', which automatically
2327 re-sets it stepping. */
2328 infrun_debug_printf ("resume : clear step");
2332 CORE_ADDR pc
= regcache_read_pc (regcache
);
2334 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2335 "current thread [%s] at %s",
2336 step
, gdb_signal_to_symbol_string (sig
),
2337 tp
->control
.trap_expected
,
2338 target_pid_to_str (inferior_ptid
).c_str (),
2339 paddress (gdbarch
, pc
));
2341 /* Normally, by the time we reach `resume', the breakpoints are either
2342 removed or inserted, as appropriate. The exception is if we're sitting
2343 at a permanent breakpoint; we need to step over it, but permanent
2344 breakpoints can't be removed. So we have to test for it here. */
2345 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2347 if (sig
!= GDB_SIGNAL_0
)
2349 /* We have a signal to pass to the inferior. The resume
2350 may, or may not take us to the signal handler. If this
2351 is a step, we'll need to stop in the signal handler, if
2352 there's one, (if the target supports stepping into
2353 handlers), or in the next mainline instruction, if
2354 there's no handler. If this is a continue, we need to be
2355 sure to run the handler with all breakpoints inserted.
2356 In all cases, set a breakpoint at the current address
2357 (where the handler returns to), and once that breakpoint
2358 is hit, resume skipping the permanent breakpoint. If
2359 that breakpoint isn't hit, then we've stepped into the
2360 signal handler (or hit some other event). We'll delete
2361 the step-resume breakpoint then. */
2363 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2364 "deliver signal first");
2366 clear_step_over_info ();
2367 tp
->control
.trap_expected
= 0;
2369 if (tp
->control
.step_resume_breakpoint
== NULL
)
2371 /* Set a "high-priority" step-resume, as we don't want
2372 user breakpoints at PC to trigger (again) when this
2374 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2375 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2377 tp
->step_after_step_resume_breakpoint
= step
;
2380 insert_breakpoints ();
2384 /* There's no signal to pass, we can go ahead and skip the
2385 permanent breakpoint manually. */
2386 infrun_debug_printf ("skipping permanent breakpoint");
2387 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2388 /* Update pc to reflect the new address from which we will
2389 execute instructions. */
2390 pc
= regcache_read_pc (regcache
);
2394 /* We've already advanced the PC, so the stepping part
2395 is done. Now we need to arrange for a trap to be
2396 reported to handle_inferior_event. Set a breakpoint
2397 at the current PC, and run to it. Don't update
2398 prev_pc, because if we end in
2399 switch_back_to_stepped_thread, we want the "expected
2400 thread advanced also" branch to be taken. IOW, we
2401 don't want this thread to step further from PC
2403 gdb_assert (!step_over_info_valid_p ());
2404 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2405 insert_breakpoints ();
2407 resume_ptid
= internal_resume_ptid (user_step
);
2408 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2415 /* If we have a breakpoint to step over, make sure to do a single
2416 step only. Same if we have software watchpoints. */
2417 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2418 tp
->control
.may_range_step
= 0;
2420 /* If displaced stepping is enabled, step over breakpoints by executing a
2421 copy of the instruction at a different address.
2423 We can't use displaced stepping when we have a signal to deliver;
2424 the comments for displaced_step_prepare explain why. The
2425 comments in the handle_inferior event for dealing with 'random
2426 signals' explain what we do instead.
2428 We can't use displaced stepping when we are waiting for vfork_done
2429 event, displaced stepping breaks the vfork child similarly as single
2430 step software breakpoint. */
2431 if (tp
->control
.trap_expected
2432 && use_displaced_stepping (tp
)
2433 && !step_over_info_valid_p ()
2434 && sig
== GDB_SIGNAL_0
2435 && !current_inferior ()->waiting_for_vfork_done
)
2437 int prepared
= displaced_step_prepare (tp
);
2441 infrun_debug_printf ("Got placed in step-over queue");
2443 tp
->control
.trap_expected
= 0;
2446 else if (prepared
< 0)
2448 /* Fallback to stepping over the breakpoint in-line. */
2450 if (target_is_non_stop_p ())
2451 stop_all_threads ();
2453 set_step_over_info (regcache
->aspace (),
2454 regcache_read_pc (regcache
), 0, tp
->global_num
);
2456 step
= maybe_software_singlestep (gdbarch
, pc
);
2458 insert_breakpoints ();
2460 else if (prepared
> 0)
2462 /* Update pc to reflect the new address from which we will
2463 execute instructions due to displaced stepping. */
2464 pc
= regcache_read_pc (get_thread_regcache (tp
));
2466 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2470 /* Do we need to do it the hard way, w/temp breakpoints? */
2472 step
= maybe_software_singlestep (gdbarch
, pc
);
2474 /* Currently, our software single-step implementation leads to different
2475 results than hardware single-stepping in one situation: when stepping
2476 into delivering a signal which has an associated signal handler,
2477 hardware single-step will stop at the first instruction of the handler,
2478 while software single-step will simply skip execution of the handler.
2480 For now, this difference in behavior is accepted since there is no
2481 easy way to actually implement single-stepping into a signal handler
2482 without kernel support.
2484 However, there is one scenario where this difference leads to follow-on
2485 problems: if we're stepping off a breakpoint by removing all breakpoints
2486 and then single-stepping. In this case, the software single-step
2487 behavior means that even if there is a *breakpoint* in the signal
2488 handler, GDB still would not stop.
2490 Fortunately, we can at least fix this particular issue. We detect
2491 here the case where we are about to deliver a signal while software
2492 single-stepping with breakpoints removed. In this situation, we
2493 revert the decisions to remove all breakpoints and insert single-
2494 step breakpoints, and instead we install a step-resume breakpoint
2495 at the current address, deliver the signal without stepping, and
2496 once we arrive back at the step-resume breakpoint, actually step
2497 over the breakpoint we originally wanted to step over. */
2498 if (thread_has_single_step_breakpoints_set (tp
)
2499 && sig
!= GDB_SIGNAL_0
2500 && step_over_info_valid_p ())
2502 /* If we have nested signals or a pending signal is delivered
2503 immediately after a handler returns, might already have
2504 a step-resume breakpoint set on the earlier handler. We cannot
2505 set another step-resume breakpoint; just continue on until the
2506 original breakpoint is hit. */
2507 if (tp
->control
.step_resume_breakpoint
== NULL
)
2509 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2510 tp
->step_after_step_resume_breakpoint
= 1;
2513 delete_single_step_breakpoints (tp
);
2515 clear_step_over_info ();
2516 tp
->control
.trap_expected
= 0;
2518 insert_breakpoints ();
2521 /* If STEP is set, it's a request to use hardware stepping
2522 facilities. But in that case, we should never
2523 use singlestep breakpoint. */
2524 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2526 /* Decide the set of threads to ask the target to resume. */
2527 if (tp
->control
.trap_expected
)
2529 /* We're allowing a thread to run past a breakpoint it has
2530 hit, either by single-stepping the thread with the breakpoint
2531 removed, or by displaced stepping, with the breakpoint inserted.
2532 In the former case, we need to single-step only this thread,
2533 and keep others stopped, as they can miss this breakpoint if
2534 allowed to run. That's not really a problem for displaced
2535 stepping, but, we still keep other threads stopped, in case
2536 another thread is also stopped for a breakpoint waiting for
2537 its turn in the displaced stepping queue. */
2538 resume_ptid
= inferior_ptid
;
2541 resume_ptid
= internal_resume_ptid (user_step
);
2543 if (execution_direction
!= EXEC_REVERSE
2544 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2546 /* There are two cases where we currently need to step a
2547 breakpoint instruction when we have a signal to deliver:
2549 - See handle_signal_stop where we handle random signals that
2550 could take out us out of the stepping range. Normally, in
2551 that case we end up continuing (instead of stepping) over the
2552 signal handler with a breakpoint at PC, but there are cases
2553 where we should _always_ single-step, even if we have a
2554 step-resume breakpoint, like when a software watchpoint is
2555 set. Assuming single-stepping and delivering a signal at the
2556 same time would takes us to the signal handler, then we could
2557 have removed the breakpoint at PC to step over it. However,
2558 some hardware step targets (like e.g., Mac OS) can't step
2559 into signal handlers, and for those, we need to leave the
2560 breakpoint at PC inserted, as otherwise if the handler
2561 recurses and executes PC again, it'll miss the breakpoint.
2562 So we leave the breakpoint inserted anyway, but we need to
2563 record that we tried to step a breakpoint instruction, so
2564 that adjust_pc_after_break doesn't end up confused.
2566 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2567 in one thread after another thread that was stepping had been
2568 momentarily paused for a step-over. When we re-resume the
2569 stepping thread, it may be resumed from that address with a
2570 breakpoint that hasn't trapped yet. Seen with
2571 gdb.threads/non-stop-fair-events.exp, on targets that don't
2572 do displaced stepping. */
2574 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2575 target_pid_to_str (tp
->ptid
).c_str ());
2577 tp
->stepped_breakpoint
= 1;
2579 /* Most targets can step a breakpoint instruction, thus
2580 executing it normally. But if this one cannot, just
2581 continue and we will hit it anyway. */
2582 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2587 && tp
->control
.trap_expected
2588 && use_displaced_stepping (tp
)
2589 && !step_over_info_valid_p ())
2591 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2592 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2593 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2596 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2597 paddress (resume_gdbarch
, actual_pc
));
2598 read_memory (actual_pc
, buf
, sizeof (buf
));
2599 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2602 if (tp
->control
.may_range_step
)
2604 /* If we're resuming a thread with the PC out of the step
2605 range, then we're doing some nested/finer run control
2606 operation, like stepping the thread out of the dynamic
2607 linker or the displaced stepping scratch pad. We
2608 shouldn't have allowed a range step then. */
2609 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2612 do_target_resume (resume_ptid
, step
, sig
);
2616 /* Resume the inferior. SIG is the signal to give the inferior
2617 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2618 rolls back state on error. */
2621 resume (gdb_signal sig
)
2627 catch (const gdb_exception
&ex
)
2629 /* If resuming is being aborted for any reason, delete any
2630 single-step breakpoint resume_1 may have created, to avoid
2631 confusing the following resumption, and to avoid leaving
2632 single-step breakpoints perturbing other threads, in case
2633 we're running in non-stop mode. */
2634 if (inferior_ptid
!= null_ptid
)
2635 delete_single_step_breakpoints (inferior_thread ());
2645 /* Counter that tracks number of user visible stops. This can be used
2646 to tell whether a command has proceeded the inferior past the
2647 current location. This allows e.g., inferior function calls in
2648 breakpoint commands to not interrupt the command list. When the
2649 call finishes successfully, the inferior is standing at the same
2650 breakpoint as if nothing happened (and so we don't call
2652 static ULONGEST current_stop_id
;
2659 return current_stop_id
;
2662 /* Called when we report a user visible stop. */
2670 /* Clear out all variables saying what to do when inferior is continued.
2671 First do this, then set the ones you want, then call `proceed'. */
2674 clear_proceed_status_thread (struct thread_info
*tp
)
2676 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2678 /* If we're starting a new sequence, then the previous finished
2679 single-step is no longer relevant. */
2680 if (tp
->suspend
.waitstatus_pending_p
)
2682 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2684 infrun_debug_printf ("pending event of %s was a finished step. "
2686 target_pid_to_str (tp
->ptid
).c_str ());
2688 tp
->suspend
.waitstatus_pending_p
= 0;
2689 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2694 ("thread %s has pending wait status %s (currently_stepping=%d).",
2695 target_pid_to_str (tp
->ptid
).c_str (),
2696 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2697 currently_stepping (tp
));
2701 /* If this signal should not be seen by program, give it zero.
2702 Used for debugging signals. */
2703 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2704 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2706 delete tp
->thread_fsm
;
2707 tp
->thread_fsm
= NULL
;
2709 tp
->control
.trap_expected
= 0;
2710 tp
->control
.step_range_start
= 0;
2711 tp
->control
.step_range_end
= 0;
2712 tp
->control
.may_range_step
= 0;
2713 tp
->control
.step_frame_id
= null_frame_id
;
2714 tp
->control
.step_stack_frame_id
= null_frame_id
;
2715 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2716 tp
->control
.step_start_function
= NULL
;
2717 tp
->stop_requested
= 0;
2719 tp
->control
.stop_step
= 0;
2721 tp
->control
.proceed_to_finish
= 0;
2723 tp
->control
.stepping_command
= 0;
2725 /* Discard any remaining commands or status from previous stop. */
2726 bpstat_clear (&tp
->control
.stop_bpstat
);
2730 clear_proceed_status (int step
)
2732 /* With scheduler-locking replay, stop replaying other threads if we're
2733 not replaying the user-visible resume ptid.
2735 This is a convenience feature to not require the user to explicitly
2736 stop replaying the other threads. We're assuming that the user's
2737 intent is to resume tracing the recorded process. */
2738 if (!non_stop
&& scheduler_mode
== schedlock_replay
2739 && target_record_is_replaying (minus_one_ptid
)
2740 && !target_record_will_replay (user_visible_resume_ptid (step
),
2741 execution_direction
))
2742 target_record_stop_replaying ();
2744 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2746 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2747 process_stratum_target
*resume_target
2748 = user_visible_resume_target (resume_ptid
);
2750 /* In all-stop mode, delete the per-thread status of all threads
2751 we're about to resume, implicitly and explicitly. */
2752 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2753 clear_proceed_status_thread (tp
);
2756 if (inferior_ptid
!= null_ptid
)
2758 struct inferior
*inferior
;
2762 /* If in non-stop mode, only delete the per-thread status of
2763 the current thread. */
2764 clear_proceed_status_thread (inferior_thread ());
2767 inferior
= current_inferior ();
2768 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2771 gdb::observers::about_to_proceed
.notify ();
2774 /* Returns true if TP is still stopped at a breakpoint that needs
2775 stepping-over in order to make progress. If the breakpoint is gone
2776 meanwhile, we can skip the whole step-over dance. */
2779 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2781 if (tp
->stepping_over_breakpoint
)
2783 struct regcache
*regcache
= get_thread_regcache (tp
);
2785 if (breakpoint_here_p (regcache
->aspace (),
2786 regcache_read_pc (regcache
))
2787 == ordinary_breakpoint_here
)
2790 tp
->stepping_over_breakpoint
= 0;
2796 /* Check whether thread TP still needs to start a step-over in order
2797 to make progress when resumed. Returns an bitwise or of enum
2798 step_over_what bits, indicating what needs to be stepped over. */
2800 static step_over_what
2801 thread_still_needs_step_over (struct thread_info
*tp
)
2803 step_over_what what
= 0;
2805 if (thread_still_needs_step_over_bp (tp
))
2806 what
|= STEP_OVER_BREAKPOINT
;
2808 if (tp
->stepping_over_watchpoint
2809 && !target_have_steppable_watchpoint ())
2810 what
|= STEP_OVER_WATCHPOINT
;
2815 /* Returns true if scheduler locking applies. STEP indicates whether
2816 we're about to do a step/next-like command to a thread. */
2819 schedlock_applies (struct thread_info
*tp
)
2821 return (scheduler_mode
== schedlock_on
2822 || (scheduler_mode
== schedlock_step
2823 && tp
->control
.stepping_command
)
2824 || (scheduler_mode
== schedlock_replay
2825 && target_record_will_replay (minus_one_ptid
,
2826 execution_direction
)));
2829 /* Calls target_commit_resume on all targets. */
2832 commit_resume_all_targets ()
2834 scoped_restore_current_thread restore_thread
;
2836 /* Map between process_target and a representative inferior. This
2837 is to avoid committing a resume in the same target more than
2838 once. Resumptions must be idempotent, so this is an
2840 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2842 for (inferior
*inf
: all_non_exited_inferiors ())
2843 if (inf
->has_execution ())
2844 conn_inf
[inf
->process_target ()] = inf
;
2846 for (const auto &ci
: conn_inf
)
2848 inferior
*inf
= ci
.second
;
2849 switch_to_inferior_no_thread (inf
);
2850 target_commit_resume ();
2854 /* Check that all the targets we're about to resume are in non-stop
2855 mode. Ideally, we'd only care whether all targets support
2856 target-async, but we're not there yet. E.g., stop_all_threads
2857 doesn't know how to handle all-stop targets. Also, the remote
2858 protocol in all-stop mode is synchronous, irrespective of
2859 target-async, which means that things like a breakpoint re-set
2860 triggered by one target would try to read memory from all targets
2864 check_multi_target_resumption (process_stratum_target
*resume_target
)
2866 if (!non_stop
&& resume_target
== nullptr)
2868 scoped_restore_current_thread restore_thread
;
2870 /* This is used to track whether we're resuming more than one
2872 process_stratum_target
*first_connection
= nullptr;
2874 /* The first inferior we see with a target that does not work in
2875 always-non-stop mode. */
2876 inferior
*first_not_non_stop
= nullptr;
2878 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2880 switch_to_inferior_no_thread (inf
);
2882 if (!target_has_execution ())
2885 process_stratum_target
*proc_target
2886 = current_inferior ()->process_target();
2888 if (!target_is_non_stop_p ())
2889 first_not_non_stop
= inf
;
2891 if (first_connection
== nullptr)
2892 first_connection
= proc_target
;
2893 else if (first_connection
!= proc_target
2894 && first_not_non_stop
!= nullptr)
2896 switch_to_inferior_no_thread (first_not_non_stop
);
2898 proc_target
= current_inferior ()->process_target();
2900 error (_("Connection %d (%s) does not support "
2901 "multi-target resumption."),
2902 proc_target
->connection_number
,
2903 make_target_connection_string (proc_target
).c_str ());
2909 /* Basic routine for continuing the program in various fashions.
2911 ADDR is the address to resume at, or -1 for resume where stopped.
2912 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2913 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2915 You should call clear_proceed_status before calling proceed. */
2918 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2920 struct regcache
*regcache
;
2921 struct gdbarch
*gdbarch
;
2923 struct execution_control_state ecss
;
2924 struct execution_control_state
*ecs
= &ecss
;
2927 /* If we're stopped at a fork/vfork, follow the branch set by the
2928 "set follow-fork-mode" command; otherwise, we'll just proceed
2929 resuming the current thread. */
2930 if (!follow_fork ())
2932 /* The target for some reason decided not to resume. */
2934 if (target_can_async_p ())
2935 inferior_event_handler (INF_EXEC_COMPLETE
);
2939 /* We'll update this if & when we switch to a new thread. */
2940 previous_inferior_ptid
= inferior_ptid
;
2942 regcache
= get_current_regcache ();
2943 gdbarch
= regcache
->arch ();
2944 const address_space
*aspace
= regcache
->aspace ();
2946 pc
= regcache_read_pc_protected (regcache
);
2948 thread_info
*cur_thr
= inferior_thread ();
2950 /* Fill in with reasonable starting values. */
2951 init_thread_stepping_state (cur_thr
);
2953 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2956 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2957 process_stratum_target
*resume_target
2958 = user_visible_resume_target (resume_ptid
);
2960 check_multi_target_resumption (resume_target
);
2962 if (addr
== (CORE_ADDR
) -1)
2964 if (pc
== cur_thr
->suspend
.stop_pc
2965 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2966 && execution_direction
!= EXEC_REVERSE
)
2967 /* There is a breakpoint at the address we will resume at,
2968 step one instruction before inserting breakpoints so that
2969 we do not stop right away (and report a second hit at this
2972 Note, we don't do this in reverse, because we won't
2973 actually be executing the breakpoint insn anyway.
2974 We'll be (un-)executing the previous instruction. */
2975 cur_thr
->stepping_over_breakpoint
= 1;
2976 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2977 && gdbarch_single_step_through_delay (gdbarch
,
2978 get_current_frame ()))
2979 /* We stepped onto an instruction that needs to be stepped
2980 again before re-inserting the breakpoint, do so. */
2981 cur_thr
->stepping_over_breakpoint
= 1;
2985 regcache_write_pc (regcache
, addr
);
2988 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2989 cur_thr
->suspend
.stop_signal
= siggnal
;
2991 /* If an exception is thrown from this point on, make sure to
2992 propagate GDB's knowledge of the executing state to the
2993 frontend/user running state. */
2994 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2996 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2997 threads (e.g., we might need to set threads stepping over
2998 breakpoints first), from the user/frontend's point of view, all
2999 threads in RESUME_PTID are now running. Unless we're calling an
3000 inferior function, as in that case we pretend the inferior
3001 doesn't run at all. */
3002 if (!cur_thr
->control
.in_infcall
)
3003 set_running (resume_target
, resume_ptid
, true);
3005 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3006 gdb_signal_to_symbol_string (siggnal
));
3008 annotate_starting ();
3010 /* Make sure that output from GDB appears before output from the
3012 gdb_flush (gdb_stdout
);
3014 /* Since we've marked the inferior running, give it the terminal. A
3015 QUIT/Ctrl-C from here on is forwarded to the target (which can
3016 still detect attempts to unblock a stuck connection with repeated
3017 Ctrl-C from within target_pass_ctrlc). */
3018 target_terminal::inferior ();
3020 /* In a multi-threaded task we may select another thread and
3021 then continue or step.
3023 But if a thread that we're resuming had stopped at a breakpoint,
3024 it will immediately cause another breakpoint stop without any
3025 execution (i.e. it will report a breakpoint hit incorrectly). So
3026 we must step over it first.
3028 Look for threads other than the current (TP) that reported a
3029 breakpoint hit and haven't been resumed yet since. */
3031 /* If scheduler locking applies, we can avoid iterating over all
3033 if (!non_stop
&& !schedlock_applies (cur_thr
))
3035 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3038 switch_to_thread_no_regs (tp
);
3040 /* Ignore the current thread here. It's handled
3045 if (!thread_still_needs_step_over (tp
))
3048 gdb_assert (!thread_is_in_step_over_chain (tp
));
3050 infrun_debug_printf ("need to step-over [%s] first",
3051 target_pid_to_str (tp
->ptid
).c_str ());
3053 thread_step_over_chain_enqueue (tp
);
3056 switch_to_thread (cur_thr
);
3059 /* Enqueue the current thread last, so that we move all other
3060 threads over their breakpoints first. */
3061 if (cur_thr
->stepping_over_breakpoint
)
3062 thread_step_over_chain_enqueue (cur_thr
);
3064 /* If the thread isn't started, we'll still need to set its prev_pc,
3065 so that switch_back_to_stepped_thread knows the thread hasn't
3066 advanced. Must do this before resuming any thread, as in
3067 all-stop/remote, once we resume we can't send any other packet
3068 until the target stops again. */
3069 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3072 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3074 started
= start_step_over ();
3076 if (step_over_info_valid_p ())
3078 /* Either this thread started a new in-line step over, or some
3079 other thread was already doing one. In either case, don't
3080 resume anything else until the step-over is finished. */
3082 else if (started
&& !target_is_non_stop_p ())
3084 /* A new displaced stepping sequence was started. In all-stop,
3085 we can't talk to the target anymore until it next stops. */
3087 else if (!non_stop
&& target_is_non_stop_p ())
3089 /* In all-stop, but the target is always in non-stop mode.
3090 Start all other threads that are implicitly resumed too. */
3091 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3094 switch_to_thread_no_regs (tp
);
3096 if (!tp
->inf
->has_execution ())
3098 infrun_debug_printf ("[%s] target has no execution",
3099 target_pid_to_str (tp
->ptid
).c_str ());
3105 infrun_debug_printf ("[%s] resumed",
3106 target_pid_to_str (tp
->ptid
).c_str ());
3107 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3111 if (thread_is_in_step_over_chain (tp
))
3113 infrun_debug_printf ("[%s] needs step-over",
3114 target_pid_to_str (tp
->ptid
).c_str ());
3118 infrun_debug_printf ("resuming %s",
3119 target_pid_to_str (tp
->ptid
).c_str ());
3121 reset_ecs (ecs
, tp
);
3122 switch_to_thread (tp
);
3123 keep_going_pass_signal (ecs
);
3124 if (!ecs
->wait_some_more
)
3125 error (_("Command aborted."));
3128 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3130 /* The thread wasn't started, and isn't queued, run it now. */
3131 reset_ecs (ecs
, cur_thr
);
3132 switch_to_thread (cur_thr
);
3133 keep_going_pass_signal (ecs
);
3134 if (!ecs
->wait_some_more
)
3135 error (_("Command aborted."));
3139 commit_resume_all_targets ();
3141 finish_state
.release ();
3143 /* If we've switched threads above, switch back to the previously
3144 current thread. We don't want the user to see a different
3146 switch_to_thread (cur_thr
);
3148 /* Tell the event loop to wait for it to stop. If the target
3149 supports asynchronous execution, it'll do this from within
3151 if (!target_can_async_p ())
3152 mark_async_event_handler (infrun_async_inferior_event_token
);
3156 /* Start remote-debugging of a machine over a serial link. */
3159 start_remote (int from_tty
)
3161 inferior
*inf
= current_inferior ();
3162 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3164 /* Always go on waiting for the target, regardless of the mode. */
3165 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3166 indicate to wait_for_inferior that a target should timeout if
3167 nothing is returned (instead of just blocking). Because of this,
3168 targets expecting an immediate response need to, internally, set
3169 things up so that the target_wait() is forced to eventually
3171 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3172 differentiate to its caller what the state of the target is after
3173 the initial open has been performed. Here we're assuming that
3174 the target has stopped. It should be possible to eventually have
3175 target_open() return to the caller an indication that the target
3176 is currently running and GDB state should be set to the same as
3177 for an async run. */
3178 wait_for_inferior (inf
);
3180 /* Now that the inferior has stopped, do any bookkeeping like
3181 loading shared libraries. We want to do this before normal_stop,
3182 so that the displayed frame is up to date. */
3183 post_create_inferior (from_tty
);
3188 /* Initialize static vars when a new inferior begins. */
3191 init_wait_for_inferior (void)
3193 /* These are meaningless until the first time through wait_for_inferior. */
3195 breakpoint_init_inferior (inf_starting
);
3197 clear_proceed_status (0);
3199 nullify_last_target_wait_ptid ();
3201 previous_inferior_ptid
= inferior_ptid
;
3206 static void handle_inferior_event (struct execution_control_state
*ecs
);
3208 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3209 struct execution_control_state
*ecs
);
3210 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3211 struct execution_control_state
*ecs
);
3212 static void handle_signal_stop (struct execution_control_state
*ecs
);
3213 static void check_exception_resume (struct execution_control_state
*,
3214 struct frame_info
*);
3216 static void end_stepping_range (struct execution_control_state
*ecs
);
3217 static void stop_waiting (struct execution_control_state
*ecs
);
3218 static void keep_going (struct execution_control_state
*ecs
);
3219 static void process_event_stop_test (struct execution_control_state
*ecs
);
3220 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3222 /* This function is attached as a "thread_stop_requested" observer.
3223 Cleanup local state that assumed the PTID was to be resumed, and
3224 report the stop to the frontend. */
3227 infrun_thread_stop_requested (ptid_t ptid
)
3229 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3231 /* PTID was requested to stop. If the thread was already stopped,
3232 but the user/frontend doesn't know about that yet (e.g., the
3233 thread had been temporarily paused for some step-over), set up
3234 for reporting the stop now. */
3235 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3237 if (tp
->state
!= THREAD_RUNNING
)
3242 /* Remove matching threads from the step-over queue, so
3243 start_step_over doesn't try to resume them
3245 if (thread_is_in_step_over_chain (tp
))
3246 thread_step_over_chain_remove (tp
);
3248 /* If the thread is stopped, but the user/frontend doesn't
3249 know about that yet, queue a pending event, as if the
3250 thread had just stopped now. Unless the thread already had
3252 if (!tp
->suspend
.waitstatus_pending_p
)
3254 tp
->suspend
.waitstatus_pending_p
= 1;
3255 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3256 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3259 /* Clear the inline-frame state, since we're re-processing the
3261 clear_inline_frame_state (tp
);
3263 /* If this thread was paused because some other thread was
3264 doing an inline-step over, let that finish first. Once
3265 that happens, we'll restart all threads and consume pending
3266 stop events then. */
3267 if (step_over_info_valid_p ())
3270 /* Otherwise we can process the (new) pending event now. Set
3271 it so this pending event is considered by
3278 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3280 if (target_last_proc_target
== tp
->inf
->process_target ()
3281 && target_last_wait_ptid
== tp
->ptid
)
3282 nullify_last_target_wait_ptid ();
3285 /* Delete the step resume, single-step and longjmp/exception resume
3286 breakpoints of TP. */
3289 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3291 delete_step_resume_breakpoint (tp
);
3292 delete_exception_resume_breakpoint (tp
);
3293 delete_single_step_breakpoints (tp
);
3296 /* If the target still has execution, call FUNC for each thread that
3297 just stopped. In all-stop, that's all the non-exited threads; in
3298 non-stop, that's the current thread, only. */
3300 typedef void (*for_each_just_stopped_thread_callback_func
)
3301 (struct thread_info
*tp
);
3304 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3306 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3309 if (target_is_non_stop_p ())
3311 /* If in non-stop mode, only the current thread stopped. */
3312 func (inferior_thread ());
3316 /* In all-stop mode, all threads have stopped. */
3317 for (thread_info
*tp
: all_non_exited_threads ())
3322 /* Delete the step resume and longjmp/exception resume breakpoints of
3323 the threads that just stopped. */
3326 delete_just_stopped_threads_infrun_breakpoints (void)
3328 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3331 /* Delete the single-step breakpoints of the threads that just
3335 delete_just_stopped_threads_single_step_breakpoints (void)
3337 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3343 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3344 const struct target_waitstatus
*ws
)
3346 std::string status_string
= target_waitstatus_to_string (ws
);
3349 /* The text is split over several lines because it was getting too long.
3350 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3351 output as a unit; we want only one timestamp printed if debug_timestamp
3354 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3357 waiton_ptid
.tid ());
3358 if (waiton_ptid
.pid () != -1)
3359 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3360 stb
.printf (", status) =\n");
3361 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3365 target_pid_to_str (result_ptid
).c_str ());
3366 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3368 /* This uses %s in part to handle %'s in the text, but also to avoid
3369 a gcc error: the format attribute requires a string literal. */
3370 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3373 /* Select a thread at random, out of those which are resumed and have
3376 static struct thread_info
*
3377 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3381 auto has_event
= [&] (thread_info
*tp
)
3383 return (tp
->ptid
.matches (waiton_ptid
)
3385 && tp
->suspend
.waitstatus_pending_p
);
3388 /* First see how many events we have. Count only resumed threads
3389 that have an event pending. */
3390 for (thread_info
*tp
: inf
->non_exited_threads ())
3394 if (num_events
== 0)
3397 /* Now randomly pick a thread out of those that have had events. */
3398 int random_selector
= (int) ((num_events
* (double) rand ())
3399 / (RAND_MAX
+ 1.0));
3402 infrun_debug_printf ("Found %d events, selecting #%d",
3403 num_events
, random_selector
);
3405 /* Select the Nth thread that has had an event. */
3406 for (thread_info
*tp
: inf
->non_exited_threads ())
3408 if (random_selector
-- == 0)
3411 gdb_assert_not_reached ("event thread not found");
3414 /* Wrapper for target_wait that first checks whether threads have
3415 pending statuses to report before actually asking the target for
3416 more events. INF is the inferior we're using to call target_wait
3420 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3421 target_waitstatus
*status
, target_wait_flags options
)
3424 struct thread_info
*tp
;
3426 /* We know that we are looking for an event in the target of inferior
3427 INF, but we don't know which thread the event might come from. As
3428 such we want to make sure that INFERIOR_PTID is reset so that none of
3429 the wait code relies on it - doing so is always a mistake. */
3430 switch_to_inferior_no_thread (inf
);
3432 /* First check if there is a resumed thread with a wait status
3434 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3436 tp
= random_pending_event_thread (inf
, ptid
);
3440 infrun_debug_printf ("Waiting for specific thread %s.",
3441 target_pid_to_str (ptid
).c_str ());
3443 /* We have a specific thread to check. */
3444 tp
= find_thread_ptid (inf
, ptid
);
3445 gdb_assert (tp
!= NULL
);
3446 if (!tp
->suspend
.waitstatus_pending_p
)
3451 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3452 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3454 struct regcache
*regcache
= get_thread_regcache (tp
);
3455 struct gdbarch
*gdbarch
= regcache
->arch ();
3459 pc
= regcache_read_pc (regcache
);
3461 if (pc
!= tp
->suspend
.stop_pc
)
3463 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3464 target_pid_to_str (tp
->ptid
).c_str (),
3465 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3466 paddress (gdbarch
, pc
));
3469 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3471 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3472 target_pid_to_str (tp
->ptid
).c_str (),
3473 paddress (gdbarch
, pc
));
3480 infrun_debug_printf ("pending event of %s cancelled.",
3481 target_pid_to_str (tp
->ptid
).c_str ());
3483 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3484 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3490 infrun_debug_printf ("Using pending wait status %s for %s.",
3491 target_waitstatus_to_string
3492 (&tp
->suspend
.waitstatus
).c_str (),
3493 target_pid_to_str (tp
->ptid
).c_str ());
3495 /* Now that we've selected our final event LWP, un-adjust its PC
3496 if it was a software breakpoint (and the target doesn't
3497 always adjust the PC itself). */
3498 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3499 && !target_supports_stopped_by_sw_breakpoint ())
3501 struct regcache
*regcache
;
3502 struct gdbarch
*gdbarch
;
3505 regcache
= get_thread_regcache (tp
);
3506 gdbarch
= regcache
->arch ();
3508 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3513 pc
= regcache_read_pc (regcache
);
3514 regcache_write_pc (regcache
, pc
+ decr_pc
);
3518 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3519 *status
= tp
->suspend
.waitstatus
;
3520 tp
->suspend
.waitstatus_pending_p
= 0;
3522 /* Wake up the event loop again, until all pending events are
3524 if (target_is_async_p ())
3525 mark_async_event_handler (infrun_async_inferior_event_token
);
3529 /* But if we don't find one, we'll have to wait. */
3531 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3533 if (!target_can_async_p ())
3534 options
&= ~TARGET_WNOHANG
;
3536 if (deprecated_target_wait_hook
)
3537 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3539 event_ptid
= target_wait (ptid
, status
, options
);
3544 /* Wrapper for target_wait that first checks whether threads have
3545 pending statuses to report before actually asking the target for
3546 more events. Polls for events from all inferiors/targets. */
3549 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3550 target_wait_flags options
)
3552 int num_inferiors
= 0;
3553 int random_selector
;
3555 /* For fairness, we pick the first inferior/target to poll at random
3556 out of all inferiors that may report events, and then continue
3557 polling the rest of the inferior list starting from that one in a
3558 circular fashion until the whole list is polled once. */
3560 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3562 return (inf
->process_target () != NULL
3563 && ptid_t (inf
->pid
).matches (wait_ptid
));
3566 /* First see how many matching inferiors we have. */
3567 for (inferior
*inf
: all_inferiors ())
3568 if (inferior_matches (inf
))
3571 if (num_inferiors
== 0)
3573 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3577 /* Now randomly pick an inferior out of those that matched. */
3578 random_selector
= (int)
3579 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3581 if (num_inferiors
> 1)
3582 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3583 num_inferiors
, random_selector
);
3585 /* Select the Nth inferior that matched. */
3587 inferior
*selected
= nullptr;
3589 for (inferior
*inf
: all_inferiors ())
3590 if (inferior_matches (inf
))
3591 if (random_selector
-- == 0)
3597 /* Now poll for events out of each of the matching inferior's
3598 targets, starting from the selected one. */
3600 auto do_wait
= [&] (inferior
*inf
)
3602 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3603 ecs
->target
= inf
->process_target ();
3604 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3607 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3608 here spuriously after the target is all stopped and we've already
3609 reported the stop to the user, polling for events. */
3610 scoped_restore_current_thread restore_thread
;
3612 int inf_num
= selected
->num
;
3613 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3614 if (inferior_matches (inf
))
3618 for (inferior
*inf
= inferior_list
;
3619 inf
!= NULL
&& inf
->num
< inf_num
;
3621 if (inferior_matches (inf
))
3625 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3629 /* Prepare and stabilize the inferior for detaching it. E.g.,
3630 detaching while a thread is displaced stepping is a recipe for
3631 crashing it, as nothing would readjust the PC out of the scratch
3635 prepare_for_detach (void)
3637 struct inferior
*inf
= current_inferior ();
3638 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3640 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3642 /* Is any thread of this process displaced stepping? If not,
3643 there's nothing else to do. */
3644 if (displaced
->step_thread
== nullptr)
3647 infrun_debug_printf ("displaced-stepping in-process while detaching");
3649 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3651 while (displaced
->step_thread
!= nullptr)
3653 struct execution_control_state ecss
;
3654 struct execution_control_state
*ecs
;
3657 memset (ecs
, 0, sizeof (*ecs
));
3659 overlay_cache_invalid
= 1;
3660 /* Flush target cache before starting to handle each event.
3661 Target was running and cache could be stale. This is just a
3662 heuristic. Running threads may modify target memory, but we
3663 don't get any event. */
3664 target_dcache_invalidate ();
3666 do_target_wait (pid_ptid
, ecs
, 0);
3669 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3671 /* If an error happens while handling the event, propagate GDB's
3672 knowledge of the executing state to the frontend/user running
3674 scoped_finish_thread_state
finish_state (inf
->process_target (),
3677 /* Now figure out what to do with the result of the result. */
3678 handle_inferior_event (ecs
);
3680 /* No error, don't finish the state yet. */
3681 finish_state
.release ();
3683 /* Breakpoints and watchpoints are not installed on the target
3684 at this point, and signals are passed directly to the
3685 inferior, so this must mean the process is gone. */
3686 if (!ecs
->wait_some_more
)
3688 restore_detaching
.release ();
3689 error (_("Program exited while detaching"));
3693 restore_detaching
.release ();
3696 /* Wait for control to return from inferior to debugger.
3698 If inferior gets a signal, we may decide to start it up again
3699 instead of returning. That is why there is a loop in this function.
3700 When this function actually returns it means the inferior
3701 should be left stopped and GDB should read more commands. */
3704 wait_for_inferior (inferior
*inf
)
3706 infrun_debug_printf ("wait_for_inferior ()");
3708 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3710 /* If an error happens while handling the event, propagate GDB's
3711 knowledge of the executing state to the frontend/user running
3713 scoped_finish_thread_state finish_state
3714 (inf
->process_target (), minus_one_ptid
);
3718 struct execution_control_state ecss
;
3719 struct execution_control_state
*ecs
= &ecss
;
3721 memset (ecs
, 0, sizeof (*ecs
));
3723 overlay_cache_invalid
= 1;
3725 /* Flush target cache before starting to handle each event.
3726 Target was running and cache could be stale. This is just a
3727 heuristic. Running threads may modify target memory, but we
3728 don't get any event. */
3729 target_dcache_invalidate ();
3731 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3732 ecs
->target
= inf
->process_target ();
3735 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3737 /* Now figure out what to do with the result of the result. */
3738 handle_inferior_event (ecs
);
3740 if (!ecs
->wait_some_more
)
3744 /* No error, don't finish the state yet. */
3745 finish_state
.release ();
3748 /* Cleanup that reinstalls the readline callback handler, if the
3749 target is running in the background. If while handling the target
3750 event something triggered a secondary prompt, like e.g., a
3751 pagination prompt, we'll have removed the callback handler (see
3752 gdb_readline_wrapper_line). Need to do this as we go back to the
3753 event loop, ready to process further input. Note this has no
3754 effect if the handler hasn't actually been removed, because calling
3755 rl_callback_handler_install resets the line buffer, thus losing
3759 reinstall_readline_callback_handler_cleanup ()
3761 struct ui
*ui
= current_ui
;
3765 /* We're not going back to the top level event loop yet. Don't
3766 install the readline callback, as it'd prep the terminal,
3767 readline-style (raw, noecho) (e.g., --batch). We'll install
3768 it the next time the prompt is displayed, when we're ready
3773 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3774 gdb_rl_callback_handler_reinstall ();
3777 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3778 that's just the event thread. In all-stop, that's all threads. */
3781 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3783 if (ecs
->event_thread
!= NULL
3784 && ecs
->event_thread
->thread_fsm
!= NULL
)
3785 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3789 for (thread_info
*thr
: all_non_exited_threads ())
3791 if (thr
->thread_fsm
== NULL
)
3793 if (thr
== ecs
->event_thread
)
3796 switch_to_thread (thr
);
3797 thr
->thread_fsm
->clean_up (thr
);
3800 if (ecs
->event_thread
!= NULL
)
3801 switch_to_thread (ecs
->event_thread
);
3805 /* Helper for all_uis_check_sync_execution_done that works on the
3809 check_curr_ui_sync_execution_done (void)
3811 struct ui
*ui
= current_ui
;
3813 if (ui
->prompt_state
== PROMPT_NEEDED
3815 && !gdb_in_secondary_prompt_p (ui
))
3817 target_terminal::ours ();
3818 gdb::observers::sync_execution_done
.notify ();
3819 ui_register_input_event_handler (ui
);
3826 all_uis_check_sync_execution_done (void)
3828 SWITCH_THRU_ALL_UIS ()
3830 check_curr_ui_sync_execution_done ();
3837 all_uis_on_sync_execution_starting (void)
3839 SWITCH_THRU_ALL_UIS ()
3841 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3842 async_disable_stdin ();
3846 /* Asynchronous version of wait_for_inferior. It is called by the
3847 event loop whenever a change of state is detected on the file
3848 descriptor corresponding to the target. It can be called more than
3849 once to complete a single execution command. In such cases we need
3850 to keep the state in a global variable ECSS. If it is the last time
3851 that this function is called for a single execution command, then
3852 report to the user that the inferior has stopped, and do the
3853 necessary cleanups. */
3856 fetch_inferior_event ()
3858 struct execution_control_state ecss
;
3859 struct execution_control_state
*ecs
= &ecss
;
3862 memset (ecs
, 0, sizeof (*ecs
));
3864 /* Events are always processed with the main UI as current UI. This
3865 way, warnings, debug output, etc. are always consistently sent to
3866 the main console. */
3867 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3869 /* Temporarily disable pagination. Otherwise, the user would be
3870 given an option to press 'q' to quit, which would cause an early
3871 exit and could leave GDB in a half-baked state. */
3872 scoped_restore save_pagination
3873 = make_scoped_restore (&pagination_enabled
, false);
3875 /* End up with readline processing input, if necessary. */
3877 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3879 /* We're handling a live event, so make sure we're doing live
3880 debugging. If we're looking at traceframes while the target is
3881 running, we're going to need to get back to that mode after
3882 handling the event. */
3883 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3886 maybe_restore_traceframe
.emplace ();
3887 set_current_traceframe (-1);
3890 /* The user/frontend should not notice a thread switch due to
3891 internal events. Make sure we revert to the user selected
3892 thread and frame after handling the event and running any
3893 breakpoint commands. */
3894 scoped_restore_current_thread restore_thread
;
3896 overlay_cache_invalid
= 1;
3897 /* Flush target cache before starting to handle each event. Target
3898 was running and cache could be stale. This is just a heuristic.
3899 Running threads may modify target memory, but we don't get any
3901 target_dcache_invalidate ();
3903 scoped_restore save_exec_dir
3904 = make_scoped_restore (&execution_direction
,
3905 target_execution_direction ());
3907 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3910 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3912 /* Switch to the target that generated the event, so we can do
3914 switch_to_target_no_thread (ecs
->target
);
3917 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3919 /* If an error happens while handling the event, propagate GDB's
3920 knowledge of the executing state to the frontend/user running
3922 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3923 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3925 /* Get executed before scoped_restore_current_thread above to apply
3926 still for the thread which has thrown the exception. */
3927 auto defer_bpstat_clear
3928 = make_scope_exit (bpstat_clear_actions
);
3929 auto defer_delete_threads
3930 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3932 /* Now figure out what to do with the result of the result. */
3933 handle_inferior_event (ecs
);
3935 if (!ecs
->wait_some_more
)
3937 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3938 int should_stop
= 1;
3939 struct thread_info
*thr
= ecs
->event_thread
;
3941 delete_just_stopped_threads_infrun_breakpoints ();
3945 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3947 if (thread_fsm
!= NULL
)
3948 should_stop
= thread_fsm
->should_stop (thr
);
3957 bool should_notify_stop
= true;
3960 clean_up_just_stopped_threads_fsms (ecs
);
3962 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3963 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3965 if (should_notify_stop
)
3967 /* We may not find an inferior if this was a process exit. */
3968 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3969 proceeded
= normal_stop ();
3974 inferior_event_handler (INF_EXEC_COMPLETE
);
3978 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3979 previously selected thread is gone. We have two
3980 choices - switch to no thread selected, or restore the
3981 previously selected thread (now exited). We chose the
3982 later, just because that's what GDB used to do. After
3983 this, "info threads" says "The current thread <Thread
3984 ID 2> has terminated." instead of "No thread
3988 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3989 restore_thread
.dont_restore ();
3993 defer_delete_threads
.release ();
3994 defer_bpstat_clear
.release ();
3996 /* No error, don't finish the thread states yet. */
3997 finish_state
.release ();
3999 /* This scope is used to ensure that readline callbacks are
4000 reinstalled here. */
4003 /* If a UI was in sync execution mode, and now isn't, restore its
4004 prompt (a synchronous execution command has finished, and we're
4005 ready for input). */
4006 all_uis_check_sync_execution_done ();
4009 && exec_done_display_p
4010 && (inferior_ptid
== null_ptid
4011 || inferior_thread ()->state
!= THREAD_RUNNING
))
4012 printf_unfiltered (_("completed.\n"));
4018 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4019 struct symtab_and_line sal
)
4021 /* This can be removed once this function no longer implicitly relies on the
4022 inferior_ptid value. */
4023 gdb_assert (inferior_ptid
== tp
->ptid
);
4025 tp
->control
.step_frame_id
= get_frame_id (frame
);
4026 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4028 tp
->current_symtab
= sal
.symtab
;
4029 tp
->current_line
= sal
.line
;
4032 /* Clear context switchable stepping state. */
4035 init_thread_stepping_state (struct thread_info
*tss
)
4037 tss
->stepped_breakpoint
= 0;
4038 tss
->stepping_over_breakpoint
= 0;
4039 tss
->stepping_over_watchpoint
= 0;
4040 tss
->step_after_step_resume_breakpoint
= 0;
4046 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4047 target_waitstatus status
)
4049 target_last_proc_target
= target
;
4050 target_last_wait_ptid
= ptid
;
4051 target_last_waitstatus
= status
;
4057 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4058 target_waitstatus
*status
)
4060 if (target
!= nullptr)
4061 *target
= target_last_proc_target
;
4062 if (ptid
!= nullptr)
4063 *ptid
= target_last_wait_ptid
;
4064 if (status
!= nullptr)
4065 *status
= target_last_waitstatus
;
4071 nullify_last_target_wait_ptid (void)
4073 target_last_proc_target
= nullptr;
4074 target_last_wait_ptid
= minus_one_ptid
;
4075 target_last_waitstatus
= {};
4078 /* Switch thread contexts. */
4081 context_switch (execution_control_state
*ecs
)
4083 if (ecs
->ptid
!= inferior_ptid
4084 && (inferior_ptid
== null_ptid
4085 || ecs
->event_thread
!= inferior_thread ()))
4087 infrun_debug_printf ("Switching context from %s to %s",
4088 target_pid_to_str (inferior_ptid
).c_str (),
4089 target_pid_to_str (ecs
->ptid
).c_str ());
4092 switch_to_thread (ecs
->event_thread
);
4095 /* If the target can't tell whether we've hit breakpoints
4096 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4097 check whether that could have been caused by a breakpoint. If so,
4098 adjust the PC, per gdbarch_decr_pc_after_break. */
4101 adjust_pc_after_break (struct thread_info
*thread
,
4102 struct target_waitstatus
*ws
)
4104 struct regcache
*regcache
;
4105 struct gdbarch
*gdbarch
;
4106 CORE_ADDR breakpoint_pc
, decr_pc
;
4108 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4109 we aren't, just return.
4111 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4112 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4113 implemented by software breakpoints should be handled through the normal
4116 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4117 different signals (SIGILL or SIGEMT for instance), but it is less
4118 clear where the PC is pointing afterwards. It may not match
4119 gdbarch_decr_pc_after_break. I don't know any specific target that
4120 generates these signals at breakpoints (the code has been in GDB since at
4121 least 1992) so I can not guess how to handle them here.
4123 In earlier versions of GDB, a target with
4124 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4125 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4126 target with both of these set in GDB history, and it seems unlikely to be
4127 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4129 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4132 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4135 /* In reverse execution, when a breakpoint is hit, the instruction
4136 under it has already been de-executed. The reported PC always
4137 points at the breakpoint address, so adjusting it further would
4138 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4141 B1 0x08000000 : INSN1
4142 B2 0x08000001 : INSN2
4144 PC -> 0x08000003 : INSN4
4146 Say you're stopped at 0x08000003 as above. Reverse continuing
4147 from that point should hit B2 as below. Reading the PC when the
4148 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4149 been de-executed already.
4151 B1 0x08000000 : INSN1
4152 B2 PC -> 0x08000001 : INSN2
4156 We can't apply the same logic as for forward execution, because
4157 we would wrongly adjust the PC to 0x08000000, since there's a
4158 breakpoint at PC - 1. We'd then report a hit on B1, although
4159 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4161 if (execution_direction
== EXEC_REVERSE
)
4164 /* If the target can tell whether the thread hit a SW breakpoint,
4165 trust it. Targets that can tell also adjust the PC
4167 if (target_supports_stopped_by_sw_breakpoint ())
4170 /* Note that relying on whether a breakpoint is planted in memory to
4171 determine this can fail. E.g,. the breakpoint could have been
4172 removed since. Or the thread could have been told to step an
4173 instruction the size of a breakpoint instruction, and only
4174 _after_ was a breakpoint inserted at its address. */
4176 /* If this target does not decrement the PC after breakpoints, then
4177 we have nothing to do. */
4178 regcache
= get_thread_regcache (thread
);
4179 gdbarch
= regcache
->arch ();
4181 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4185 const address_space
*aspace
= regcache
->aspace ();
4187 /* Find the location where (if we've hit a breakpoint) the
4188 breakpoint would be. */
4189 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4191 /* If the target can't tell whether a software breakpoint triggered,
4192 fallback to figuring it out based on breakpoints we think were
4193 inserted in the target, and on whether the thread was stepped or
4196 /* Check whether there actually is a software breakpoint inserted at
4199 If in non-stop mode, a race condition is possible where we've
4200 removed a breakpoint, but stop events for that breakpoint were
4201 already queued and arrive later. To suppress those spurious
4202 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4203 and retire them after a number of stop events are reported. Note
4204 this is an heuristic and can thus get confused. The real fix is
4205 to get the "stopped by SW BP and needs adjustment" info out of
4206 the target/kernel (and thus never reach here; see above). */
4207 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4208 || (target_is_non_stop_p ()
4209 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4211 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4213 if (record_full_is_used ())
4214 restore_operation_disable
.emplace
4215 (record_full_gdb_operation_disable_set ());
4217 /* When using hardware single-step, a SIGTRAP is reported for both
4218 a completed single-step and a software breakpoint. Need to
4219 differentiate between the two, as the latter needs adjusting
4220 but the former does not.
4222 The SIGTRAP can be due to a completed hardware single-step only if
4223 - we didn't insert software single-step breakpoints
4224 - this thread is currently being stepped
4226 If any of these events did not occur, we must have stopped due
4227 to hitting a software breakpoint, and have to back up to the
4230 As a special case, we could have hardware single-stepped a
4231 software breakpoint. In this case (prev_pc == breakpoint_pc),
4232 we also need to back up to the breakpoint address. */
4234 if (thread_has_single_step_breakpoints_set (thread
)
4235 || !currently_stepping (thread
)
4236 || (thread
->stepped_breakpoint
4237 && thread
->prev_pc
== breakpoint_pc
))
4238 regcache_write_pc (regcache
, breakpoint_pc
);
4243 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4245 for (frame
= get_prev_frame (frame
);
4247 frame
= get_prev_frame (frame
))
4249 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4252 if (get_frame_type (frame
) != INLINE_FRAME
)
4259 /* Look for an inline frame that is marked for skip.
4260 If PREV_FRAME is TRUE start at the previous frame,
4261 otherwise start at the current frame. Stop at the
4262 first non-inline frame, or at the frame where the
4266 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4268 struct frame_info
*frame
= get_current_frame ();
4271 frame
= get_prev_frame (frame
);
4273 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4275 const char *fn
= NULL
;
4276 symtab_and_line sal
;
4279 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4281 if (get_frame_type (frame
) != INLINE_FRAME
)
4284 sal
= find_frame_sal (frame
);
4285 sym
= get_frame_function (frame
);
4288 fn
= sym
->print_name ();
4291 && function_name_is_marked_for_skip (fn
, sal
))
4298 /* If the event thread has the stop requested flag set, pretend it
4299 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4303 handle_stop_requested (struct execution_control_state
*ecs
)
4305 if (ecs
->event_thread
->stop_requested
)
4307 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4308 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4309 handle_signal_stop (ecs
);
4315 /* Auxiliary function that handles syscall entry/return events.
4316 It returns true if the inferior should keep going (and GDB
4317 should ignore the event), or false if the event deserves to be
4321 handle_syscall_event (struct execution_control_state
*ecs
)
4323 struct regcache
*regcache
;
4326 context_switch (ecs
);
4328 regcache
= get_thread_regcache (ecs
->event_thread
);
4329 syscall_number
= ecs
->ws
.value
.syscall_number
;
4330 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4332 if (catch_syscall_enabled () > 0
4333 && catching_syscall_number (syscall_number
) > 0)
4335 infrun_debug_printf ("syscall number=%d", syscall_number
);
4337 ecs
->event_thread
->control
.stop_bpstat
4338 = bpstat_stop_status (regcache
->aspace (),
4339 ecs
->event_thread
->suspend
.stop_pc
,
4340 ecs
->event_thread
, &ecs
->ws
);
4342 if (handle_stop_requested (ecs
))
4345 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4347 /* Catchpoint hit. */
4352 if (handle_stop_requested (ecs
))
4355 /* 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 ())
4899 bool any_sync
= false;
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
= false;
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
= true;
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
= false;
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 displaced_step_fixup (ecs
->event_thread
,
5683 ecs
->event_thread
->suspend
.stop_signal
);
5685 bool had_step_over_info
= step_over_info_valid_p ();
5687 if (had_step_over_info
)
5689 /* If we're stepping over a breakpoint with all threads locked,
5690 then only the thread that was stepped should be reporting
5692 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5694 clear_step_over_info ();
5697 if (!target_is_non_stop_p ())
5700 /* Start a new step-over in another thread if there's one that
5704 /* If we were stepping over a breakpoint before, and haven't started
5705 a new in-line step-over sequence, then restart all other threads
5706 (except the event thread). We can't do this in all-stop, as then
5707 e.g., we wouldn't be able to issue any other remote packet until
5708 these other threads stop. */
5709 if (had_step_over_info
&& !step_over_info_valid_p ())
5711 struct thread_info
*pending
;
5713 /* If we only have threads with pending statuses, the restart
5714 below won't restart any thread and so nothing re-inserts the
5715 breakpoint we just stepped over. But we need it inserted
5716 when we later process the pending events, otherwise if
5717 another thread has a pending event for this breakpoint too,
5718 we'd discard its event (because the breakpoint that
5719 originally caused the event was no longer inserted). */
5720 context_switch (ecs
);
5721 insert_breakpoints ();
5723 restart_threads (ecs
->event_thread
);
5725 /* If we have events pending, go through handle_inferior_event
5726 again, picking up a pending event at random. This avoids
5727 thread starvation. */
5729 /* But not if we just stepped over a watchpoint in order to let
5730 the instruction execute so we can evaluate its expression.
5731 The set of watchpoints that triggered is recorded in the
5732 breakpoint objects themselves (see bp->watchpoint_triggered).
5733 If we processed another event first, that other event could
5734 clobber this info. */
5735 if (ecs
->event_thread
->stepping_over_watchpoint
)
5738 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5740 if (pending
!= NULL
)
5742 struct thread_info
*tp
= ecs
->event_thread
;
5743 struct regcache
*regcache
;
5745 infrun_debug_printf ("found resumed threads with "
5746 "pending events, saving status");
5748 gdb_assert (pending
!= tp
);
5750 /* Record the event thread's event for later. */
5751 save_waitstatus (tp
, &ecs
->ws
);
5752 /* This was cleared early, by handle_inferior_event. Set it
5753 so this pending event is considered by
5757 gdb_assert (!tp
->executing
);
5759 regcache
= get_thread_regcache (tp
);
5760 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5762 infrun_debug_printf ("saved stop_pc=%s for %s "
5763 "(currently_stepping=%d)",
5764 paddress (target_gdbarch (),
5765 tp
->suspend
.stop_pc
),
5766 target_pid_to_str (tp
->ptid
).c_str (),
5767 currently_stepping (tp
));
5769 /* This in-line step-over finished; clear this so we won't
5770 start a new one. This is what handle_signal_stop would
5771 do, if we returned false. */
5772 tp
->stepping_over_breakpoint
= 0;
5774 /* Wake up the event loop again. */
5775 mark_async_event_handler (infrun_async_inferior_event_token
);
5777 prepare_to_wait (ecs
);
5785 /* Come here when the program has stopped with a signal. */
5788 handle_signal_stop (struct execution_control_state
*ecs
)
5790 struct frame_info
*frame
;
5791 struct gdbarch
*gdbarch
;
5792 int stopped_by_watchpoint
;
5793 enum stop_kind stop_soon
;
5796 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5798 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5800 /* Do we need to clean up the state of a thread that has
5801 completed a displaced single-step? (Doing so usually affects
5802 the PC, so do it here, before we set stop_pc.) */
5803 if (finish_step_over (ecs
))
5806 /* If we either finished a single-step or hit a breakpoint, but
5807 the user wanted this thread to be stopped, pretend we got a
5808 SIG0 (generic unsignaled stop). */
5809 if (ecs
->event_thread
->stop_requested
5810 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5811 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5813 ecs
->event_thread
->suspend
.stop_pc
5814 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5818 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5819 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5821 switch_to_thread (ecs
->event_thread
);
5823 infrun_debug_printf ("stop_pc=%s",
5824 paddress (reg_gdbarch
,
5825 ecs
->event_thread
->suspend
.stop_pc
));
5826 if (target_stopped_by_watchpoint ())
5830 infrun_debug_printf ("stopped by watchpoint");
5832 if (target_stopped_data_address (current_top_target (), &addr
))
5833 infrun_debug_printf ("stopped data address=%s",
5834 paddress (reg_gdbarch
, addr
));
5836 infrun_debug_printf ("(no data address available)");
5840 /* This is originated from start_remote(), start_inferior() and
5841 shared libraries hook functions. */
5842 stop_soon
= get_inferior_stop_soon (ecs
);
5843 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5845 context_switch (ecs
);
5846 infrun_debug_printf ("quietly stopped");
5847 stop_print_frame
= true;
5852 /* This originates from attach_command(). We need to overwrite
5853 the stop_signal here, because some kernels don't ignore a
5854 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5855 See more comments in inferior.h. On the other hand, if we
5856 get a non-SIGSTOP, report it to the user - assume the backend
5857 will handle the SIGSTOP if it should show up later.
5859 Also consider that the attach is complete when we see a
5860 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5861 target extended-remote report it instead of a SIGSTOP
5862 (e.g. gdbserver). We already rely on SIGTRAP being our
5863 signal, so this is no exception.
5865 Also consider that the attach is complete when we see a
5866 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5867 the target to stop all threads of the inferior, in case the
5868 low level attach operation doesn't stop them implicitly. If
5869 they weren't stopped implicitly, then the stub will report a
5870 GDB_SIGNAL_0, meaning: stopped for no particular reason
5871 other than GDB's request. */
5872 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5873 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5874 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5875 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5877 stop_print_frame
= true;
5879 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5883 /* See if something interesting happened to the non-current thread. If
5884 so, then switch to that thread. */
5885 if (ecs
->ptid
!= inferior_ptid
)
5887 infrun_debug_printf ("context switch");
5889 context_switch (ecs
);
5891 if (deprecated_context_hook
)
5892 deprecated_context_hook (ecs
->event_thread
->global_num
);
5895 /* At this point, get hold of the now-current thread's frame. */
5896 frame
= get_current_frame ();
5897 gdbarch
= get_frame_arch (frame
);
5899 /* Pull the single step breakpoints out of the target. */
5900 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5902 struct regcache
*regcache
;
5905 regcache
= get_thread_regcache (ecs
->event_thread
);
5906 const address_space
*aspace
= regcache
->aspace ();
5908 pc
= regcache_read_pc (regcache
);
5910 /* However, before doing so, if this single-step breakpoint was
5911 actually for another thread, set this thread up for moving
5913 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5916 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5918 infrun_debug_printf ("[%s] hit another thread's single-step "
5920 target_pid_to_str (ecs
->ptid
).c_str ());
5921 ecs
->hit_singlestep_breakpoint
= 1;
5926 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5927 target_pid_to_str (ecs
->ptid
).c_str ());
5930 delete_just_stopped_threads_single_step_breakpoints ();
5932 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5933 && ecs
->event_thread
->control
.trap_expected
5934 && ecs
->event_thread
->stepping_over_watchpoint
)
5935 stopped_by_watchpoint
= 0;
5937 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5939 /* If necessary, step over this watchpoint. We'll be back to display
5941 if (stopped_by_watchpoint
5942 && (target_have_steppable_watchpoint ()
5943 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5945 /* At this point, we are stopped at an instruction which has
5946 attempted to write to a piece of memory under control of
5947 a watchpoint. The instruction hasn't actually executed
5948 yet. If we were to evaluate the watchpoint expression
5949 now, we would get the old value, and therefore no change
5950 would seem to have occurred.
5952 In order to make watchpoints work `right', we really need
5953 to complete the memory write, and then evaluate the
5954 watchpoint expression. We do this by single-stepping the
5957 It may not be necessary to disable the watchpoint to step over
5958 it. For example, the PA can (with some kernel cooperation)
5959 single step over a watchpoint without disabling the watchpoint.
5961 It is far more common to need to disable a watchpoint to step
5962 the inferior over it. If we have non-steppable watchpoints,
5963 we must disable the current watchpoint; it's simplest to
5964 disable all watchpoints.
5966 Any breakpoint at PC must also be stepped over -- if there's
5967 one, it will have already triggered before the watchpoint
5968 triggered, and we either already reported it to the user, or
5969 it didn't cause a stop and we called keep_going. In either
5970 case, if there was a breakpoint at PC, we must be trying to
5972 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5977 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5978 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5979 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5980 ecs
->event_thread
->control
.stop_step
= 0;
5981 stop_print_frame
= true;
5982 stopped_by_random_signal
= 0;
5983 bpstat stop_chain
= NULL
;
5985 /* Hide inlined functions starting here, unless we just performed stepi or
5986 nexti. After stepi and nexti, always show the innermost frame (not any
5987 inline function call sites). */
5988 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5990 const address_space
*aspace
5991 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5993 /* skip_inline_frames is expensive, so we avoid it if we can
5994 determine that the address is one where functions cannot have
5995 been inlined. This improves performance with inferiors that
5996 load a lot of shared libraries, because the solib event
5997 breakpoint is defined as the address of a function (i.e. not
5998 inline). Note that we have to check the previous PC as well
5999 as the current one to catch cases when we have just
6000 single-stepped off a breakpoint prior to reinstating it.
6001 Note that we're assuming that the code we single-step to is
6002 not inline, but that's not definitive: there's nothing
6003 preventing the event breakpoint function from containing
6004 inlined code, and the single-step ending up there. If the
6005 user had set a breakpoint on that inlined code, the missing
6006 skip_inline_frames call would break things. Fortunately
6007 that's an extremely unlikely scenario. */
6008 if (!pc_at_non_inline_function (aspace
,
6009 ecs
->event_thread
->suspend
.stop_pc
,
6011 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6012 && ecs
->event_thread
->control
.trap_expected
6013 && pc_at_non_inline_function (aspace
,
6014 ecs
->event_thread
->prev_pc
,
6017 stop_chain
= build_bpstat_chain (aspace
,
6018 ecs
->event_thread
->suspend
.stop_pc
,
6020 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6022 /* Re-fetch current thread's frame in case that invalidated
6024 frame
= get_current_frame ();
6025 gdbarch
= get_frame_arch (frame
);
6029 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6030 && ecs
->event_thread
->control
.trap_expected
6031 && gdbarch_single_step_through_delay_p (gdbarch
)
6032 && currently_stepping (ecs
->event_thread
))
6034 /* We're trying to step off a breakpoint. Turns out that we're
6035 also on an instruction that needs to be stepped multiple
6036 times before it's been fully executing. E.g., architectures
6037 with a delay slot. It needs to be stepped twice, once for
6038 the instruction and once for the delay slot. */
6039 int step_through_delay
6040 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6042 if (step_through_delay
)
6043 infrun_debug_printf ("step through delay");
6045 if (ecs
->event_thread
->control
.step_range_end
== 0
6046 && step_through_delay
)
6048 /* The user issued a continue when stopped at a breakpoint.
6049 Set up for another trap and get out of here. */
6050 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6054 else if (step_through_delay
)
6056 /* The user issued a step when stopped at a breakpoint.
6057 Maybe we should stop, maybe we should not - the delay
6058 slot *might* correspond to a line of source. In any
6059 case, don't decide that here, just set
6060 ecs->stepping_over_breakpoint, making sure we
6061 single-step again before breakpoints are re-inserted. */
6062 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6066 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6067 handles this event. */
6068 ecs
->event_thread
->control
.stop_bpstat
6069 = bpstat_stop_status (get_current_regcache ()->aspace (),
6070 ecs
->event_thread
->suspend
.stop_pc
,
6071 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6073 /* Following in case break condition called a
6075 stop_print_frame
= true;
6077 /* This is where we handle "moribund" watchpoints. Unlike
6078 software breakpoints traps, hardware watchpoint traps are
6079 always distinguishable from random traps. If no high-level
6080 watchpoint is associated with the reported stop data address
6081 anymore, then the bpstat does not explain the signal ---
6082 simply make sure to ignore it if `stopped_by_watchpoint' is
6085 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6086 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6088 && stopped_by_watchpoint
)
6090 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6094 /* NOTE: cagney/2003-03-29: These checks for a random signal
6095 at one stage in the past included checks for an inferior
6096 function call's call dummy's return breakpoint. The original
6097 comment, that went with the test, read:
6099 ``End of a stack dummy. Some systems (e.g. Sony news) give
6100 another signal besides SIGTRAP, so check here as well as
6103 If someone ever tries to get call dummys on a
6104 non-executable stack to work (where the target would stop
6105 with something like a SIGSEGV), then those tests might need
6106 to be re-instated. Given, however, that the tests were only
6107 enabled when momentary breakpoints were not being used, I
6108 suspect that it won't be the case.
6110 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6111 be necessary for call dummies on a non-executable stack on
6114 /* See if the breakpoints module can explain the signal. */
6116 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6117 ecs
->event_thread
->suspend
.stop_signal
);
6119 /* Maybe this was a trap for a software breakpoint that has since
6121 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6123 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6124 ecs
->event_thread
->suspend
.stop_pc
))
6126 struct regcache
*regcache
;
6129 /* Re-adjust PC to what the program would see if GDB was not
6131 regcache
= get_thread_regcache (ecs
->event_thread
);
6132 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6135 gdb::optional
<scoped_restore_tmpl
<int>>
6136 restore_operation_disable
;
6138 if (record_full_is_used ())
6139 restore_operation_disable
.emplace
6140 (record_full_gdb_operation_disable_set ());
6142 regcache_write_pc (regcache
,
6143 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6148 /* A delayed software breakpoint event. Ignore the trap. */
6149 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6154 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6155 has since been removed. */
6156 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6158 /* A delayed hardware breakpoint event. Ignore the trap. */
6159 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6164 /* If not, perhaps stepping/nexting can. */
6166 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6167 && currently_stepping (ecs
->event_thread
));
6169 /* Perhaps the thread hit a single-step breakpoint of _another_
6170 thread. Single-step breakpoints are transparent to the
6171 breakpoints module. */
6173 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6175 /* No? Perhaps we got a moribund watchpoint. */
6177 random_signal
= !stopped_by_watchpoint
;
6179 /* Always stop if the user explicitly requested this thread to
6181 if (ecs
->event_thread
->stop_requested
)
6184 infrun_debug_printf ("user-requested stop");
6187 /* For the program's own signals, act according to
6188 the signal handling tables. */
6192 /* Signal not for debugging purposes. */
6193 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6194 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6196 infrun_debug_printf ("random signal (%s)",
6197 gdb_signal_to_symbol_string (stop_signal
));
6199 stopped_by_random_signal
= 1;
6201 /* Always stop on signals if we're either just gaining control
6202 of the program, or the user explicitly requested this thread
6203 to remain stopped. */
6204 if (stop_soon
!= NO_STOP_QUIETLY
6205 || ecs
->event_thread
->stop_requested
6207 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6213 /* Notify observers the signal has "handle print" set. Note we
6214 returned early above if stopping; normal_stop handles the
6215 printing in that case. */
6216 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6218 /* The signal table tells us to print about this signal. */
6219 target_terminal::ours_for_output ();
6220 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6221 target_terminal::inferior ();
6224 /* Clear the signal if it should not be passed. */
6225 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6226 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6228 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6229 && ecs
->event_thread
->control
.trap_expected
6230 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6232 /* We were just starting a new sequence, attempting to
6233 single-step off of a breakpoint and expecting a SIGTRAP.
6234 Instead this signal arrives. This signal will take us out
6235 of the stepping range so GDB needs to remember to, when
6236 the signal handler returns, resume stepping off that
6238 /* To simplify things, "continue" is forced to use the same
6239 code paths as single-step - set a breakpoint at the
6240 signal return address and then, once hit, step off that
6242 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6244 insert_hp_step_resume_breakpoint_at_frame (frame
);
6245 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6246 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6247 ecs
->event_thread
->control
.trap_expected
= 0;
6249 /* If we were nexting/stepping some other thread, switch to
6250 it, so that we don't continue it, losing control. */
6251 if (!switch_back_to_stepped_thread (ecs
))
6256 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6257 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6259 || ecs
->event_thread
->control
.step_range_end
== 1)
6260 && frame_id_eq (get_stack_frame_id (frame
),
6261 ecs
->event_thread
->control
.step_stack_frame_id
)
6262 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6264 /* The inferior is about to take a signal that will take it
6265 out of the single step range. Set a breakpoint at the
6266 current PC (which is presumably where the signal handler
6267 will eventually return) and then allow the inferior to
6270 Note that this is only needed for a signal delivered
6271 while in the single-step range. Nested signals aren't a
6272 problem as they eventually all return. */
6273 infrun_debug_printf ("signal may take us out of single-step range");
6275 clear_step_over_info ();
6276 insert_hp_step_resume_breakpoint_at_frame (frame
);
6277 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6278 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6279 ecs
->event_thread
->control
.trap_expected
= 0;
6284 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6285 when either there's a nested signal, or when there's a
6286 pending signal enabled just as the signal handler returns
6287 (leaving the inferior at the step-resume-breakpoint without
6288 actually executing it). Either way continue until the
6289 breakpoint is really hit. */
6291 if (!switch_back_to_stepped_thread (ecs
))
6293 infrun_debug_printf ("random signal, keep going");
6300 process_event_stop_test (ecs
);
6303 /* Come here when we've got some debug event / signal we can explain
6304 (IOW, not a random signal), and test whether it should cause a
6305 stop, or whether we should resume the inferior (transparently).
6306 E.g., could be a breakpoint whose condition evaluates false; we
6307 could be still stepping within the line; etc. */
6310 process_event_stop_test (struct execution_control_state
*ecs
)
6312 struct symtab_and_line stop_pc_sal
;
6313 struct frame_info
*frame
;
6314 struct gdbarch
*gdbarch
;
6315 CORE_ADDR jmp_buf_pc
;
6316 struct bpstat_what what
;
6318 /* Handle cases caused by hitting a breakpoint. */
6320 frame
= get_current_frame ();
6321 gdbarch
= get_frame_arch (frame
);
6323 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6325 if (what
.call_dummy
)
6327 stop_stack_dummy
= what
.call_dummy
;
6330 /* A few breakpoint types have callbacks associated (e.g.,
6331 bp_jit_event). Run them now. */
6332 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6334 /* If we hit an internal event that triggers symbol changes, the
6335 current frame will be invalidated within bpstat_what (e.g., if we
6336 hit an internal solib event). Re-fetch it. */
6337 frame
= get_current_frame ();
6338 gdbarch
= get_frame_arch (frame
);
6340 switch (what
.main_action
)
6342 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6343 /* If we hit the breakpoint at longjmp while stepping, we
6344 install a momentary breakpoint at the target of the
6347 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6349 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6351 if (what
.is_longjmp
)
6353 struct value
*arg_value
;
6355 /* If we set the longjmp breakpoint via a SystemTap probe,
6356 then use it to extract the arguments. The destination PC
6357 is the third argument to the probe. */
6358 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6361 jmp_buf_pc
= value_as_address (arg_value
);
6362 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6364 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6365 || !gdbarch_get_longjmp_target (gdbarch
,
6366 frame
, &jmp_buf_pc
))
6368 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6369 "(!gdbarch_get_longjmp_target)");
6374 /* Insert a breakpoint at resume address. */
6375 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6378 check_exception_resume (ecs
, frame
);
6382 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6384 struct frame_info
*init_frame
;
6386 /* There are several cases to consider.
6388 1. The initiating frame no longer exists. In this case we
6389 must stop, because the exception or longjmp has gone too
6392 2. The initiating frame exists, and is the same as the
6393 current frame. We stop, because the exception or longjmp
6396 3. The initiating frame exists and is different from the
6397 current frame. This means the exception or longjmp has
6398 been caught beneath the initiating frame, so keep going.
6400 4. longjmp breakpoint has been placed just to protect
6401 against stale dummy frames and user is not interested in
6402 stopping around longjmps. */
6404 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6406 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6408 delete_exception_resume_breakpoint (ecs
->event_thread
);
6410 if (what
.is_longjmp
)
6412 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6414 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6422 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6426 struct frame_id current_id
6427 = get_frame_id (get_current_frame ());
6428 if (frame_id_eq (current_id
,
6429 ecs
->event_thread
->initiating_frame
))
6431 /* Case 2. Fall through. */
6441 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6443 delete_step_resume_breakpoint (ecs
->event_thread
);
6445 end_stepping_range (ecs
);
6449 case BPSTAT_WHAT_SINGLE
:
6450 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6451 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6452 /* Still need to check other stuff, at least the case where we
6453 are stepping and step out of the right range. */
6456 case BPSTAT_WHAT_STEP_RESUME
:
6457 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6459 delete_step_resume_breakpoint (ecs
->event_thread
);
6460 if (ecs
->event_thread
->control
.proceed_to_finish
6461 && execution_direction
== EXEC_REVERSE
)
6463 struct thread_info
*tp
= ecs
->event_thread
;
6465 /* We are finishing a function in reverse, and just hit the
6466 step-resume breakpoint at the start address of the
6467 function, and we're almost there -- just need to back up
6468 by one more single-step, which should take us back to the
6470 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6474 fill_in_stop_func (gdbarch
, ecs
);
6475 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6476 && execution_direction
== EXEC_REVERSE
)
6478 /* We are stepping over a function call in reverse, and just
6479 hit the step-resume breakpoint at the start address of
6480 the function. Go back to single-stepping, which should
6481 take us back to the function call. */
6482 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6488 case BPSTAT_WHAT_STOP_NOISY
:
6489 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6490 stop_print_frame
= true;
6492 /* Assume the thread stopped for a breakpoint. We'll still check
6493 whether a/the breakpoint is there when the thread is next
6495 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6500 case BPSTAT_WHAT_STOP_SILENT
:
6501 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6502 stop_print_frame
= false;
6504 /* Assume the thread stopped for a breakpoint. We'll still check
6505 whether a/the breakpoint is there when the thread is next
6507 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6511 case BPSTAT_WHAT_HP_STEP_RESUME
:
6512 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6514 delete_step_resume_breakpoint (ecs
->event_thread
);
6515 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6517 /* Back when the step-resume breakpoint was inserted, we
6518 were trying to single-step off a breakpoint. Go back to
6520 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6521 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6527 case BPSTAT_WHAT_KEEP_CHECKING
:
6531 /* If we stepped a permanent breakpoint and we had a high priority
6532 step-resume breakpoint for the address we stepped, but we didn't
6533 hit it, then we must have stepped into the signal handler. The
6534 step-resume was only necessary to catch the case of _not_
6535 stepping into the handler, so delete it, and fall through to
6536 checking whether the step finished. */
6537 if (ecs
->event_thread
->stepped_breakpoint
)
6539 struct breakpoint
*sr_bp
6540 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6543 && sr_bp
->loc
->permanent
6544 && sr_bp
->type
== bp_hp_step_resume
6545 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6547 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6548 delete_step_resume_breakpoint (ecs
->event_thread
);
6549 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6553 /* We come here if we hit a breakpoint but should not stop for it.
6554 Possibly we also were stepping and should stop for that. So fall
6555 through and test for stepping. But, if not stepping, do not
6558 /* In all-stop mode, if we're currently stepping but have stopped in
6559 some other thread, we need to switch back to the stepped thread. */
6560 if (switch_back_to_stepped_thread (ecs
))
6563 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6565 infrun_debug_printf ("step-resume breakpoint is inserted");
6567 /* Having a step-resume breakpoint overrides anything
6568 else having to do with stepping commands until
6569 that breakpoint is reached. */
6574 if (ecs
->event_thread
->control
.step_range_end
== 0)
6576 infrun_debug_printf ("no stepping, continue");
6577 /* Likewise if we aren't even stepping. */
6582 /* Re-fetch current thread's frame in case the code above caused
6583 the frame cache to be re-initialized, making our FRAME variable
6584 a dangling pointer. */
6585 frame
= get_current_frame ();
6586 gdbarch
= get_frame_arch (frame
);
6587 fill_in_stop_func (gdbarch
, ecs
);
6589 /* If stepping through a line, keep going if still within it.
6591 Note that step_range_end is the address of the first instruction
6592 beyond the step range, and NOT the address of the last instruction
6595 Note also that during reverse execution, we may be stepping
6596 through a function epilogue and therefore must detect when
6597 the current-frame changes in the middle of a line. */
6599 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6601 && (execution_direction
!= EXEC_REVERSE
6602 || frame_id_eq (get_frame_id (frame
),
6603 ecs
->event_thread
->control
.step_frame_id
)))
6606 ("stepping inside range [%s-%s]",
6607 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6608 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6610 /* Tentatively re-enable range stepping; `resume' disables it if
6611 necessary (e.g., if we're stepping over a breakpoint or we
6612 have software watchpoints). */
6613 ecs
->event_thread
->control
.may_range_step
= 1;
6615 /* When stepping backward, stop at beginning of line range
6616 (unless it's the function entry point, in which case
6617 keep going back to the call point). */
6618 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6619 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6620 && stop_pc
!= ecs
->stop_func_start
6621 && execution_direction
== EXEC_REVERSE
)
6622 end_stepping_range (ecs
);
6629 /* We stepped out of the stepping range. */
6631 /* If we are stepping at the source level and entered the runtime
6632 loader dynamic symbol resolution code...
6634 EXEC_FORWARD: we keep on single stepping until we exit the run
6635 time loader code and reach the callee's address.
6637 EXEC_REVERSE: we've already executed the callee (backward), and
6638 the runtime loader code is handled just like any other
6639 undebuggable function call. Now we need only keep stepping
6640 backward through the trampoline code, and that's handled further
6641 down, so there is nothing for us to do here. */
6643 if (execution_direction
!= EXEC_REVERSE
6644 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6645 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6647 CORE_ADDR pc_after_resolver
=
6648 gdbarch_skip_solib_resolver (gdbarch
,
6649 ecs
->event_thread
->suspend
.stop_pc
);
6651 infrun_debug_printf ("stepped into dynsym resolve code");
6653 if (pc_after_resolver
)
6655 /* Set up a step-resume breakpoint at the address
6656 indicated by SKIP_SOLIB_RESOLVER. */
6657 symtab_and_line sr_sal
;
6658 sr_sal
.pc
= pc_after_resolver
;
6659 sr_sal
.pspace
= get_frame_program_space (frame
);
6661 insert_step_resume_breakpoint_at_sal (gdbarch
,
6662 sr_sal
, null_frame_id
);
6669 /* Step through an indirect branch thunk. */
6670 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6671 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6672 ecs
->event_thread
->suspend
.stop_pc
))
6674 infrun_debug_printf ("stepped into indirect branch thunk");
6679 if (ecs
->event_thread
->control
.step_range_end
!= 1
6680 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6681 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6682 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6684 infrun_debug_printf ("stepped into signal trampoline");
6685 /* The inferior, while doing a "step" or "next", has ended up in
6686 a signal trampoline (either by a signal being delivered or by
6687 the signal handler returning). Just single-step until the
6688 inferior leaves the trampoline (either by calling the handler
6694 /* If we're in the return path from a shared library trampoline,
6695 we want to proceed through the trampoline when stepping. */
6696 /* macro/2012-04-25: This needs to come before the subroutine
6697 call check below as on some targets return trampolines look
6698 like subroutine calls (MIPS16 return thunks). */
6699 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6700 ecs
->event_thread
->suspend
.stop_pc
,
6701 ecs
->stop_func_name
)
6702 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6704 /* Determine where this trampoline returns. */
6705 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6706 CORE_ADDR real_stop_pc
6707 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6709 infrun_debug_printf ("stepped into solib return tramp");
6711 /* Only proceed through if we know where it's going. */
6714 /* And put the step-breakpoint there and go until there. */
6715 symtab_and_line sr_sal
;
6716 sr_sal
.pc
= real_stop_pc
;
6717 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6718 sr_sal
.pspace
= get_frame_program_space (frame
);
6720 /* Do not specify what the fp should be when we stop since
6721 on some machines the prologue is where the new fp value
6723 insert_step_resume_breakpoint_at_sal (gdbarch
,
6724 sr_sal
, null_frame_id
);
6726 /* Restart without fiddling with the step ranges or
6733 /* Check for subroutine calls. The check for the current frame
6734 equalling the step ID is not necessary - the check of the
6735 previous frame's ID is sufficient - but it is a common case and
6736 cheaper than checking the previous frame's ID.
6738 NOTE: frame_id_eq will never report two invalid frame IDs as
6739 being equal, so to get into this block, both the current and
6740 previous frame must have valid frame IDs. */
6741 /* The outer_frame_id check is a heuristic to detect stepping
6742 through startup code. If we step over an instruction which
6743 sets the stack pointer from an invalid value to a valid value,
6744 we may detect that as a subroutine call from the mythical
6745 "outermost" function. This could be fixed by marking
6746 outermost frames as !stack_p,code_p,special_p. Then the
6747 initial outermost frame, before sp was valid, would
6748 have code_addr == &_start. See the comment in frame_id_eq
6750 if (!frame_id_eq (get_stack_frame_id (frame
),
6751 ecs
->event_thread
->control
.step_stack_frame_id
)
6752 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6753 ecs
->event_thread
->control
.step_stack_frame_id
)
6754 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6756 || (ecs
->event_thread
->control
.step_start_function
6757 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6759 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6760 CORE_ADDR real_stop_pc
;
6762 infrun_debug_printf ("stepped into subroutine");
6764 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6766 /* I presume that step_over_calls is only 0 when we're
6767 supposed to be stepping at the assembly language level
6768 ("stepi"). Just stop. */
6769 /* And this works the same backward as frontward. MVS */
6770 end_stepping_range (ecs
);
6774 /* Reverse stepping through solib trampolines. */
6776 if (execution_direction
== EXEC_REVERSE
6777 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6778 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6779 || (ecs
->stop_func_start
== 0
6780 && in_solib_dynsym_resolve_code (stop_pc
))))
6782 /* Any solib trampoline code can be handled in reverse
6783 by simply continuing to single-step. We have already
6784 executed the solib function (backwards), and a few
6785 steps will take us back through the trampoline to the
6791 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6793 /* We're doing a "next".
6795 Normal (forward) execution: set a breakpoint at the
6796 callee's return address (the address at which the caller
6799 Reverse (backward) execution. set the step-resume
6800 breakpoint at the start of the function that we just
6801 stepped into (backwards), and continue to there. When we
6802 get there, we'll need to single-step back to the caller. */
6804 if (execution_direction
== EXEC_REVERSE
)
6806 /* If we're already at the start of the function, we've either
6807 just stepped backward into a single instruction function,
6808 or stepped back out of a signal handler to the first instruction
6809 of the function. Just keep going, which will single-step back
6811 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6813 /* Normal function call return (static or dynamic). */
6814 symtab_and_line sr_sal
;
6815 sr_sal
.pc
= ecs
->stop_func_start
;
6816 sr_sal
.pspace
= get_frame_program_space (frame
);
6817 insert_step_resume_breakpoint_at_sal (gdbarch
,
6818 sr_sal
, null_frame_id
);
6822 insert_step_resume_breakpoint_at_caller (frame
);
6828 /* If we are in a function call trampoline (a stub between the
6829 calling routine and the real function), locate the real
6830 function. That's what tells us (a) whether we want to step
6831 into it at all, and (b) what prologue we want to run to the
6832 end of, if we do step into it. */
6833 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6834 if (real_stop_pc
== 0)
6835 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6836 if (real_stop_pc
!= 0)
6837 ecs
->stop_func_start
= real_stop_pc
;
6839 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6841 symtab_and_line sr_sal
;
6842 sr_sal
.pc
= ecs
->stop_func_start
;
6843 sr_sal
.pspace
= get_frame_program_space (frame
);
6845 insert_step_resume_breakpoint_at_sal (gdbarch
,
6846 sr_sal
, null_frame_id
);
6851 /* If we have line number information for the function we are
6852 thinking of stepping into and the function isn't on the skip
6855 If there are several symtabs at that PC (e.g. with include
6856 files), just want to know whether *any* of them have line
6857 numbers. find_pc_line handles this. */
6859 struct symtab_and_line tmp_sal
;
6861 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6862 if (tmp_sal
.line
!= 0
6863 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6865 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6867 if (execution_direction
== EXEC_REVERSE
)
6868 handle_step_into_function_backward (gdbarch
, ecs
);
6870 handle_step_into_function (gdbarch
, ecs
);
6875 /* If we have no line number and the step-stop-if-no-debug is
6876 set, we stop the step so that the user has a chance to switch
6877 in assembly mode. */
6878 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6879 && step_stop_if_no_debug
)
6881 end_stepping_range (ecs
);
6885 if (execution_direction
== EXEC_REVERSE
)
6887 /* If we're already at the start of the function, we've either just
6888 stepped backward into a single instruction function without line
6889 number info, or stepped back out of a signal handler to the first
6890 instruction of the function without line number info. Just keep
6891 going, which will single-step back to the caller. */
6892 if (ecs
->stop_func_start
!= stop_pc
)
6894 /* Set a breakpoint at callee's start address.
6895 From there we can step once and be back in the caller. */
6896 symtab_and_line sr_sal
;
6897 sr_sal
.pc
= ecs
->stop_func_start
;
6898 sr_sal
.pspace
= get_frame_program_space (frame
);
6899 insert_step_resume_breakpoint_at_sal (gdbarch
,
6900 sr_sal
, null_frame_id
);
6904 /* Set a breakpoint at callee's return address (the address
6905 at which the caller will resume). */
6906 insert_step_resume_breakpoint_at_caller (frame
);
6912 /* Reverse stepping through solib trampolines. */
6914 if (execution_direction
== EXEC_REVERSE
6915 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6917 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6919 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6920 || (ecs
->stop_func_start
== 0
6921 && in_solib_dynsym_resolve_code (stop_pc
)))
6923 /* Any solib trampoline code can be handled in reverse
6924 by simply continuing to single-step. We have already
6925 executed the solib function (backwards), and a few
6926 steps will take us back through the trampoline to the
6931 else if (in_solib_dynsym_resolve_code (stop_pc
))
6933 /* Stepped backward into the solib dynsym resolver.
6934 Set a breakpoint at its start and continue, then
6935 one more step will take us out. */
6936 symtab_and_line sr_sal
;
6937 sr_sal
.pc
= ecs
->stop_func_start
;
6938 sr_sal
.pspace
= get_frame_program_space (frame
);
6939 insert_step_resume_breakpoint_at_sal (gdbarch
,
6940 sr_sal
, null_frame_id
);
6946 /* This always returns the sal for the inner-most frame when we are in a
6947 stack of inlined frames, even if GDB actually believes that it is in a
6948 more outer frame. This is checked for below by calls to
6949 inline_skipped_frames. */
6950 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6952 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6953 the trampoline processing logic, however, there are some trampolines
6954 that have no names, so we should do trampoline handling first. */
6955 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6956 && ecs
->stop_func_name
== NULL
6957 && stop_pc_sal
.line
== 0)
6959 infrun_debug_printf ("stepped into undebuggable function");
6961 /* The inferior just stepped into, or returned to, an
6962 undebuggable function (where there is no debugging information
6963 and no line number corresponding to the address where the
6964 inferior stopped). Since we want to skip this kind of code,
6965 we keep going until the inferior returns from this
6966 function - unless the user has asked us not to (via
6967 set step-mode) or we no longer know how to get back
6968 to the call site. */
6969 if (step_stop_if_no_debug
6970 || !frame_id_p (frame_unwind_caller_id (frame
)))
6972 /* If we have no line number and the step-stop-if-no-debug
6973 is set, we stop the step so that the user has a chance to
6974 switch in assembly mode. */
6975 end_stepping_range (ecs
);
6980 /* Set a breakpoint at callee's return address (the address
6981 at which the caller will resume). */
6982 insert_step_resume_breakpoint_at_caller (frame
);
6988 if (ecs
->event_thread
->control
.step_range_end
== 1)
6990 /* It is stepi or nexti. We always want to stop stepping after
6992 infrun_debug_printf ("stepi/nexti");
6993 end_stepping_range (ecs
);
6997 if (stop_pc_sal
.line
== 0)
6999 /* We have no line number information. That means to stop
7000 stepping (does this always happen right after one instruction,
7001 when we do "s" in a function with no line numbers,
7002 or can this happen as a result of a return or longjmp?). */
7003 infrun_debug_printf ("line number info");
7004 end_stepping_range (ecs
);
7008 /* Look for "calls" to inlined functions, part one. If the inline
7009 frame machinery detected some skipped call sites, we have entered
7010 a new inline function. */
7012 if (frame_id_eq (get_frame_id (get_current_frame ()),
7013 ecs
->event_thread
->control
.step_frame_id
)
7014 && inline_skipped_frames (ecs
->event_thread
))
7016 infrun_debug_printf ("stepped into inlined function");
7018 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7020 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7022 /* For "step", we're going to stop. But if the call site
7023 for this inlined function is on the same source line as
7024 we were previously stepping, go down into the function
7025 first. Otherwise stop at the call site. */
7027 if (call_sal
.line
== ecs
->event_thread
->current_line
7028 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7030 step_into_inline_frame (ecs
->event_thread
);
7031 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7038 end_stepping_range (ecs
);
7043 /* For "next", we should stop at the call site if it is on a
7044 different source line. Otherwise continue through the
7045 inlined function. */
7046 if (call_sal
.line
== ecs
->event_thread
->current_line
7047 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7050 end_stepping_range (ecs
);
7055 /* Look for "calls" to inlined functions, part two. If we are still
7056 in the same real function we were stepping through, but we have
7057 to go further up to find the exact frame ID, we are stepping
7058 through a more inlined call beyond its call site. */
7060 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7061 && !frame_id_eq (get_frame_id (get_current_frame ()),
7062 ecs
->event_thread
->control
.step_frame_id
)
7063 && stepped_in_from (get_current_frame (),
7064 ecs
->event_thread
->control
.step_frame_id
))
7066 infrun_debug_printf ("stepping through inlined function");
7068 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7069 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7072 end_stepping_range (ecs
);
7076 bool refresh_step_info
= true;
7077 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7078 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7079 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7081 if (stop_pc_sal
.is_stmt
)
7083 /* We are at the start of a different line. So stop. Note that
7084 we don't stop if we step into the middle of a different line.
7085 That is said to make things like for (;;) statements work
7087 infrun_debug_printf ("stepped to a different line");
7088 end_stepping_range (ecs
);
7091 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7092 ecs
->event_thread
->control
.step_frame_id
))
7094 /* We are at the start of a different line, however, this line is
7095 not marked as a statement, and we have not changed frame. We
7096 ignore this line table entry, and continue stepping forward,
7097 looking for a better place to stop. */
7098 refresh_step_info
= false;
7099 infrun_debug_printf ("stepped to a different line, but "
7100 "it's not the start of a statement");
7104 /* We aren't done stepping.
7106 Optimize by setting the stepping range to the line.
7107 (We might not be in the original line, but if we entered a
7108 new line in mid-statement, we continue stepping. This makes
7109 things like for(;;) statements work better.)
7111 If we entered a SAL that indicates a non-statement line table entry,
7112 then we update the stepping range, but we don't update the step info,
7113 which includes things like the line number we are stepping away from.
7114 This means we will stop when we find a line table entry that is marked
7115 as is-statement, even if it matches the non-statement one we just
7118 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7119 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7120 ecs
->event_thread
->control
.may_range_step
= 1;
7121 if (refresh_step_info
)
7122 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7124 infrun_debug_printf ("keep going");
7128 /* In all-stop mode, if we're currently stepping but have stopped in
7129 some other thread, we may need to switch back to the stepped
7130 thread. Returns true we set the inferior running, false if we left
7131 it stopped (and the event needs further processing). */
7134 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7136 if (!target_is_non_stop_p ())
7138 struct thread_info
*stepping_thread
;
7140 /* If any thread is blocked on some internal breakpoint, and we
7141 simply need to step over that breakpoint to get it going
7142 again, do that first. */
7144 /* However, if we see an event for the stepping thread, then we
7145 know all other threads have been moved past their breakpoints
7146 already. Let the caller check whether the step is finished,
7147 etc., before deciding to move it past a breakpoint. */
7148 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7151 /* Check if the current thread is blocked on an incomplete
7152 step-over, interrupted by a random signal. */
7153 if (ecs
->event_thread
->control
.trap_expected
7154 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7157 ("need to finish step-over of [%s]",
7158 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7163 /* Check if the current thread is blocked by a single-step
7164 breakpoint of another thread. */
7165 if (ecs
->hit_singlestep_breakpoint
)
7167 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7168 target_pid_to_str (ecs
->ptid
).c_str ());
7173 /* If this thread needs yet another step-over (e.g., stepping
7174 through a delay slot), do it first before moving on to
7176 if (thread_still_needs_step_over (ecs
->event_thread
))
7179 ("thread [%s] still needs step-over",
7180 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7185 /* If scheduler locking applies even if not stepping, there's no
7186 need to walk over threads. Above we've checked whether the
7187 current thread is stepping. If some other thread not the
7188 event thread is stepping, then it must be that scheduler
7189 locking is not in effect. */
7190 if (schedlock_applies (ecs
->event_thread
))
7193 /* Otherwise, we no longer expect a trap in the current thread.
7194 Clear the trap_expected flag before switching back -- this is
7195 what keep_going does as well, if we call it. */
7196 ecs
->event_thread
->control
.trap_expected
= 0;
7198 /* Likewise, clear the signal if it should not be passed. */
7199 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7200 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7202 /* Do all pending step-overs before actually proceeding with
7204 if (start_step_over ())
7206 prepare_to_wait (ecs
);
7210 /* Look for the stepping/nexting thread. */
7211 stepping_thread
= NULL
;
7213 for (thread_info
*tp
: all_non_exited_threads ())
7215 switch_to_thread_no_regs (tp
);
7217 /* Ignore threads of processes the caller is not
7220 && (tp
->inf
->process_target () != ecs
->target
7221 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7224 /* When stepping over a breakpoint, we lock all threads
7225 except the one that needs to move past the breakpoint.
7226 If a non-event thread has this set, the "incomplete
7227 step-over" check above should have caught it earlier. */
7228 if (tp
->control
.trap_expected
)
7230 internal_error (__FILE__
, __LINE__
,
7231 "[%s] has inconsistent state: "
7232 "trap_expected=%d\n",
7233 target_pid_to_str (tp
->ptid
).c_str (),
7234 tp
->control
.trap_expected
);
7237 /* Did we find the stepping thread? */
7238 if (tp
->control
.step_range_end
)
7240 /* Yep. There should only one though. */
7241 gdb_assert (stepping_thread
== NULL
);
7243 /* The event thread is handled at the top, before we
7245 gdb_assert (tp
!= ecs
->event_thread
);
7247 /* If some thread other than the event thread is
7248 stepping, then scheduler locking can't be in effect,
7249 otherwise we wouldn't have resumed the current event
7250 thread in the first place. */
7251 gdb_assert (!schedlock_applies (tp
));
7253 stepping_thread
= tp
;
7257 if (stepping_thread
!= NULL
)
7259 infrun_debug_printf ("switching back to stepped thread");
7261 if (keep_going_stepped_thread (stepping_thread
))
7263 prepare_to_wait (ecs
);
7268 switch_to_thread (ecs
->event_thread
);
7274 /* Set a previously stepped thread back to stepping. Returns true on
7275 success, false if the resume is not possible (e.g., the thread
7279 keep_going_stepped_thread (struct thread_info
*tp
)
7281 struct frame_info
*frame
;
7282 struct execution_control_state ecss
;
7283 struct execution_control_state
*ecs
= &ecss
;
7285 /* If the stepping thread exited, then don't try to switch back and
7286 resume it, which could fail in several different ways depending
7287 on the target. Instead, just keep going.
7289 We can find a stepping dead thread in the thread list in two
7292 - The target supports thread exit events, and when the target
7293 tries to delete the thread from the thread list, inferior_ptid
7294 pointed at the exiting thread. In such case, calling
7295 delete_thread does not really remove the thread from the list;
7296 instead, the thread is left listed, with 'exited' state.
7298 - The target's debug interface does not support thread exit
7299 events, and so we have no idea whatsoever if the previously
7300 stepping thread is still alive. For that reason, we need to
7301 synchronously query the target now. */
7303 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7305 infrun_debug_printf ("not resuming previously stepped thread, it has "
7312 infrun_debug_printf ("resuming previously stepped thread");
7314 reset_ecs (ecs
, tp
);
7315 switch_to_thread (tp
);
7317 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7318 frame
= get_current_frame ();
7320 /* If the PC of the thread we were trying to single-step has
7321 changed, then that thread has trapped or been signaled, but the
7322 event has not been reported to GDB yet. Re-poll the target
7323 looking for this particular thread's event (i.e. temporarily
7324 enable schedlock) by:
7326 - setting a break at the current PC
7327 - resuming that particular thread, only (by setting trap
7330 This prevents us continuously moving the single-step breakpoint
7331 forward, one instruction at a time, overstepping. */
7333 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7337 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7338 paddress (target_gdbarch (), tp
->prev_pc
),
7339 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7341 /* Clear the info of the previous step-over, as it's no longer
7342 valid (if the thread was trying to step over a breakpoint, it
7343 has already succeeded). It's what keep_going would do too,
7344 if we called it. Do this before trying to insert the sss
7345 breakpoint, otherwise if we were previously trying to step
7346 over this exact address in another thread, the breakpoint is
7348 clear_step_over_info ();
7349 tp
->control
.trap_expected
= 0;
7351 insert_single_step_breakpoint (get_frame_arch (frame
),
7352 get_frame_address_space (frame
),
7353 tp
->suspend
.stop_pc
);
7356 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7357 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7361 infrun_debug_printf ("expected thread still hasn't advanced");
7363 keep_going_pass_signal (ecs
);
7369 /* Is thread TP in the middle of (software or hardware)
7370 single-stepping? (Note the result of this function must never be
7371 passed directly as target_resume's STEP parameter.) */
7374 currently_stepping (struct thread_info
*tp
)
7376 return ((tp
->control
.step_range_end
7377 && tp
->control
.step_resume_breakpoint
== NULL
)
7378 || tp
->control
.trap_expected
7379 || tp
->stepped_breakpoint
7380 || bpstat_should_step ());
7383 /* Inferior has stepped into a subroutine call with source code that
7384 we should not step over. Do step to the first line of code in
7388 handle_step_into_function (struct gdbarch
*gdbarch
,
7389 struct execution_control_state
*ecs
)
7391 fill_in_stop_func (gdbarch
, ecs
);
7393 compunit_symtab
*cust
7394 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7395 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7396 ecs
->stop_func_start
7397 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7399 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7400 /* Use the step_resume_break to step until the end of the prologue,
7401 even if that involves jumps (as it seems to on the vax under
7403 /* If the prologue ends in the middle of a source line, continue to
7404 the end of that source line (if it is still within the function).
7405 Otherwise, just go to end of prologue. */
7406 if (stop_func_sal
.end
7407 && stop_func_sal
.pc
!= ecs
->stop_func_start
7408 && stop_func_sal
.end
< ecs
->stop_func_end
)
7409 ecs
->stop_func_start
= stop_func_sal
.end
;
7411 /* Architectures which require breakpoint adjustment might not be able
7412 to place a breakpoint at the computed address. If so, the test
7413 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7414 ecs->stop_func_start to an address at which a breakpoint may be
7415 legitimately placed.
7417 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7418 made, GDB will enter an infinite loop when stepping through
7419 optimized code consisting of VLIW instructions which contain
7420 subinstructions corresponding to different source lines. On
7421 FR-V, it's not permitted to place a breakpoint on any but the
7422 first subinstruction of a VLIW instruction. When a breakpoint is
7423 set, GDB will adjust the breakpoint address to the beginning of
7424 the VLIW instruction. Thus, we need to make the corresponding
7425 adjustment here when computing the stop address. */
7427 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7429 ecs
->stop_func_start
7430 = gdbarch_adjust_breakpoint_address (gdbarch
,
7431 ecs
->stop_func_start
);
7434 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7436 /* We are already there: stop now. */
7437 end_stepping_range (ecs
);
7442 /* Put the step-breakpoint there and go until there. */
7443 symtab_and_line sr_sal
;
7444 sr_sal
.pc
= ecs
->stop_func_start
;
7445 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7446 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7448 /* Do not specify what the fp should be when we stop since on
7449 some machines the prologue is where the new fp value is
7451 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7453 /* And make sure stepping stops right away then. */
7454 ecs
->event_thread
->control
.step_range_end
7455 = ecs
->event_thread
->control
.step_range_start
;
7460 /* Inferior has stepped backward into a subroutine call with source
7461 code that we should not step over. Do step to the beginning of the
7462 last line of code in it. */
7465 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7466 struct execution_control_state
*ecs
)
7468 struct compunit_symtab
*cust
;
7469 struct symtab_and_line stop_func_sal
;
7471 fill_in_stop_func (gdbarch
, ecs
);
7473 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7474 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7475 ecs
->stop_func_start
7476 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7478 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7480 /* OK, we're just going to keep stepping here. */
7481 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7483 /* We're there already. Just stop stepping now. */
7484 end_stepping_range (ecs
);
7488 /* Else just reset the step range and keep going.
7489 No step-resume breakpoint, they don't work for
7490 epilogues, which can have multiple entry paths. */
7491 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7492 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7498 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7499 This is used to both functions and to skip over code. */
7502 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7503 struct symtab_and_line sr_sal
,
7504 struct frame_id sr_id
,
7505 enum bptype sr_type
)
7507 /* There should never be more than one step-resume or longjmp-resume
7508 breakpoint per thread, so we should never be setting a new
7509 step_resume_breakpoint when one is already active. */
7510 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7511 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7513 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7514 paddress (gdbarch
, sr_sal
.pc
));
7516 inferior_thread ()->control
.step_resume_breakpoint
7517 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7521 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7522 struct symtab_and_line sr_sal
,
7523 struct frame_id sr_id
)
7525 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7530 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7531 This is used to skip a potential signal handler.
7533 This is called with the interrupted function's frame. The signal
7534 handler, when it returns, will resume the interrupted function at
7538 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7540 gdb_assert (return_frame
!= NULL
);
7542 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7544 symtab_and_line sr_sal
;
7545 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7546 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7547 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7549 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7550 get_stack_frame_id (return_frame
),
7554 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7555 is used to skip a function after stepping into it (for "next" or if
7556 the called function has no debugging information).
7558 The current function has almost always been reached by single
7559 stepping a call or return instruction. NEXT_FRAME belongs to the
7560 current function, and the breakpoint will be set at the caller's
7563 This is a separate function rather than reusing
7564 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7565 get_prev_frame, which may stop prematurely (see the implementation
7566 of frame_unwind_caller_id for an example). */
7569 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7571 /* We shouldn't have gotten here if we don't know where the call site
7573 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7575 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7577 symtab_and_line sr_sal
;
7578 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7579 frame_unwind_caller_pc (next_frame
));
7580 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7581 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7583 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7584 frame_unwind_caller_id (next_frame
));
7587 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7588 new breakpoint at the target of a jmp_buf. The handling of
7589 longjmp-resume uses the same mechanisms used for handling
7590 "step-resume" breakpoints. */
7593 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7595 /* There should never be more than one longjmp-resume breakpoint per
7596 thread, so we should never be setting a new
7597 longjmp_resume_breakpoint when one is already active. */
7598 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7600 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7601 paddress (gdbarch
, pc
));
7603 inferior_thread ()->control
.exception_resume_breakpoint
=
7604 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7607 /* Insert an exception resume breakpoint. TP is the thread throwing
7608 the exception. The block B is the block of the unwinder debug hook
7609 function. FRAME is the frame corresponding to the call to this
7610 function. SYM is the symbol of the function argument holding the
7611 target PC of the exception. */
7614 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7615 const struct block
*b
,
7616 struct frame_info
*frame
,
7621 struct block_symbol vsym
;
7622 struct value
*value
;
7624 struct breakpoint
*bp
;
7626 vsym
= lookup_symbol_search_name (sym
->search_name (),
7628 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7629 /* If the value was optimized out, revert to the old behavior. */
7630 if (! value_optimized_out (value
))
7632 handler
= value_as_address (value
);
7634 infrun_debug_printf ("exception resume at %lx",
7635 (unsigned long) handler
);
7637 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7639 bp_exception_resume
).release ();
7641 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7644 bp
->thread
= tp
->global_num
;
7645 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7648 catch (const gdb_exception_error
&e
)
7650 /* We want to ignore errors here. */
7654 /* A helper for check_exception_resume that sets an
7655 exception-breakpoint based on a SystemTap probe. */
7658 insert_exception_resume_from_probe (struct thread_info
*tp
,
7659 const struct bound_probe
*probe
,
7660 struct frame_info
*frame
)
7662 struct value
*arg_value
;
7664 struct breakpoint
*bp
;
7666 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7670 handler
= value_as_address (arg_value
);
7672 infrun_debug_printf ("exception resume at %s",
7673 paddress (probe
->objfile
->arch (), handler
));
7675 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7676 handler
, bp_exception_resume
).release ();
7677 bp
->thread
= tp
->global_num
;
7678 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7681 /* This is called when an exception has been intercepted. Check to
7682 see whether the exception's destination is of interest, and if so,
7683 set an exception resume breakpoint there. */
7686 check_exception_resume (struct execution_control_state
*ecs
,
7687 struct frame_info
*frame
)
7689 struct bound_probe probe
;
7690 struct symbol
*func
;
7692 /* First see if this exception unwinding breakpoint was set via a
7693 SystemTap probe point. If so, the probe has two arguments: the
7694 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7695 set a breakpoint there. */
7696 probe
= find_probe_by_pc (get_frame_pc (frame
));
7699 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7703 func
= get_frame_function (frame
);
7709 const struct block
*b
;
7710 struct block_iterator iter
;
7714 /* The exception breakpoint is a thread-specific breakpoint on
7715 the unwinder's debug hook, declared as:
7717 void _Unwind_DebugHook (void *cfa, void *handler);
7719 The CFA argument indicates the frame to which control is
7720 about to be transferred. HANDLER is the destination PC.
7722 We ignore the CFA and set a temporary breakpoint at HANDLER.
7723 This is not extremely efficient but it avoids issues in gdb
7724 with computing the DWARF CFA, and it also works even in weird
7725 cases such as throwing an exception from inside a signal
7728 b
= SYMBOL_BLOCK_VALUE (func
);
7729 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7731 if (!SYMBOL_IS_ARGUMENT (sym
))
7738 insert_exception_resume_breakpoint (ecs
->event_thread
,
7744 catch (const gdb_exception_error
&e
)
7750 stop_waiting (struct execution_control_state
*ecs
)
7752 infrun_debug_printf ("stop_waiting");
7754 /* Let callers know we don't want to wait for the inferior anymore. */
7755 ecs
->wait_some_more
= 0;
7757 /* If all-stop, but there exists a non-stop target, stop all
7758 threads now that we're presenting the stop to the user. */
7759 if (!non_stop
&& exists_non_stop_target ())
7760 stop_all_threads ();
7763 /* Like keep_going, but passes the signal to the inferior, even if the
7764 signal is set to nopass. */
7767 keep_going_pass_signal (struct execution_control_state
*ecs
)
7769 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7770 gdb_assert (!ecs
->event_thread
->resumed
);
7772 /* Save the pc before execution, to compare with pc after stop. */
7773 ecs
->event_thread
->prev_pc
7774 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7776 if (ecs
->event_thread
->control
.trap_expected
)
7778 struct thread_info
*tp
= ecs
->event_thread
;
7780 infrun_debug_printf ("%s has trap_expected set, "
7781 "resuming to collect trap",
7782 target_pid_to_str (tp
->ptid
).c_str ());
7784 /* We haven't yet gotten our trap, and either: intercepted a
7785 non-signal event (e.g., a fork); or took a signal which we
7786 are supposed to pass through to the inferior. Simply
7788 resume (ecs
->event_thread
->suspend
.stop_signal
);
7790 else if (step_over_info_valid_p ())
7792 /* Another thread is stepping over a breakpoint in-line. If
7793 this thread needs a step-over too, queue the request. In
7794 either case, this resume must be deferred for later. */
7795 struct thread_info
*tp
= ecs
->event_thread
;
7797 if (ecs
->hit_singlestep_breakpoint
7798 || thread_still_needs_step_over (tp
))
7800 infrun_debug_printf ("step-over already in progress: "
7801 "step-over for %s deferred",
7802 target_pid_to_str (tp
->ptid
).c_str ());
7803 thread_step_over_chain_enqueue (tp
);
7807 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7808 target_pid_to_str (tp
->ptid
).c_str ());
7813 struct regcache
*regcache
= get_current_regcache ();
7816 step_over_what step_what
;
7818 /* Either the trap was not expected, but we are continuing
7819 anyway (if we got a signal, the user asked it be passed to
7822 We got our expected trap, but decided we should resume from
7825 We're going to run this baby now!
7827 Note that insert_breakpoints won't try to re-insert
7828 already inserted breakpoints. Therefore, we don't
7829 care if breakpoints were already inserted, or not. */
7831 /* If we need to step over a breakpoint, and we're not using
7832 displaced stepping to do so, insert all breakpoints
7833 (watchpoints, etc.) but the one we're stepping over, step one
7834 instruction, and then re-insert the breakpoint when that step
7837 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7839 remove_bp
= (ecs
->hit_singlestep_breakpoint
7840 || (step_what
& STEP_OVER_BREAKPOINT
));
7841 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7843 /* We can't use displaced stepping if we need to step past a
7844 watchpoint. The instruction copied to the scratch pad would
7845 still trigger the watchpoint. */
7847 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7849 set_step_over_info (regcache
->aspace (),
7850 regcache_read_pc (regcache
), remove_wps
,
7851 ecs
->event_thread
->global_num
);
7853 else if (remove_wps
)
7854 set_step_over_info (NULL
, 0, remove_wps
, -1);
7856 /* If we now need to do an in-line step-over, we need to stop
7857 all other threads. Note this must be done before
7858 insert_breakpoints below, because that removes the breakpoint
7859 we're about to step over, otherwise other threads could miss
7861 if (step_over_info_valid_p () && target_is_non_stop_p ())
7862 stop_all_threads ();
7864 /* Stop stepping if inserting breakpoints fails. */
7867 insert_breakpoints ();
7869 catch (const gdb_exception_error
&e
)
7871 exception_print (gdb_stderr
, e
);
7873 clear_step_over_info ();
7877 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7879 resume (ecs
->event_thread
->suspend
.stop_signal
);
7882 prepare_to_wait (ecs
);
7885 /* Called when we should continue running the inferior, because the
7886 current event doesn't cause a user visible stop. This does the
7887 resuming part; waiting for the next event is done elsewhere. */
7890 keep_going (struct execution_control_state
*ecs
)
7892 if (ecs
->event_thread
->control
.trap_expected
7893 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7894 ecs
->event_thread
->control
.trap_expected
= 0;
7896 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7897 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7898 keep_going_pass_signal (ecs
);
7901 /* This function normally comes after a resume, before
7902 handle_inferior_event exits. It takes care of any last bits of
7903 housekeeping, and sets the all-important wait_some_more flag. */
7906 prepare_to_wait (struct execution_control_state
*ecs
)
7908 infrun_debug_printf ("prepare_to_wait");
7910 ecs
->wait_some_more
= 1;
7912 /* If the target can't async, emulate it by marking the infrun event
7913 handler such that as soon as we get back to the event-loop, we
7914 immediately end up in fetch_inferior_event again calling
7916 if (!target_can_async_p ())
7917 mark_infrun_async_event_handler ();
7920 /* We are done with the step range of a step/next/si/ni command.
7921 Called once for each n of a "step n" operation. */
7924 end_stepping_range (struct execution_control_state
*ecs
)
7926 ecs
->event_thread
->control
.stop_step
= 1;
7930 /* Several print_*_reason functions to print why the inferior has stopped.
7931 We always print something when the inferior exits, or receives a signal.
7932 The rest of the cases are dealt with later on in normal_stop and
7933 print_it_typical. Ideally there should be a call to one of these
7934 print_*_reason functions functions from handle_inferior_event each time
7935 stop_waiting is called.
7937 Note that we don't call these directly, instead we delegate that to
7938 the interpreters, through observers. Interpreters then call these
7939 with whatever uiout is right. */
7942 print_end_stepping_range_reason (struct ui_out
*uiout
)
7944 /* For CLI-like interpreters, print nothing. */
7946 if (uiout
->is_mi_like_p ())
7948 uiout
->field_string ("reason",
7949 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7954 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7956 annotate_signalled ();
7957 if (uiout
->is_mi_like_p ())
7959 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7960 uiout
->text ("\nProgram terminated with signal ");
7961 annotate_signal_name ();
7962 uiout
->field_string ("signal-name",
7963 gdb_signal_to_name (siggnal
));
7964 annotate_signal_name_end ();
7966 annotate_signal_string ();
7967 uiout
->field_string ("signal-meaning",
7968 gdb_signal_to_string (siggnal
));
7969 annotate_signal_string_end ();
7970 uiout
->text (".\n");
7971 uiout
->text ("The program no longer exists.\n");
7975 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7977 struct inferior
*inf
= current_inferior ();
7978 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7980 annotate_exited (exitstatus
);
7983 if (uiout
->is_mi_like_p ())
7984 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7985 std::string exit_code_str
7986 = string_printf ("0%o", (unsigned int) exitstatus
);
7987 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7988 plongest (inf
->num
), pidstr
.c_str (),
7989 string_field ("exit-code", exit_code_str
.c_str ()));
7993 if (uiout
->is_mi_like_p ())
7995 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7996 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7997 plongest (inf
->num
), pidstr
.c_str ());
8002 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8004 struct thread_info
*thr
= inferior_thread ();
8008 if (uiout
->is_mi_like_p ())
8010 else if (show_thread_that_caused_stop ())
8014 uiout
->text ("\nThread ");
8015 uiout
->field_string ("thread-id", print_thread_id (thr
));
8017 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8020 uiout
->text (" \"");
8021 uiout
->field_string ("name", name
);
8026 uiout
->text ("\nProgram");
8028 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8029 uiout
->text (" stopped");
8032 uiout
->text (" received signal ");
8033 annotate_signal_name ();
8034 if (uiout
->is_mi_like_p ())
8036 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8037 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8038 annotate_signal_name_end ();
8040 annotate_signal_string ();
8041 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8043 struct regcache
*regcache
= get_current_regcache ();
8044 struct gdbarch
*gdbarch
= regcache
->arch ();
8045 if (gdbarch_report_signal_info_p (gdbarch
))
8046 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8048 annotate_signal_string_end ();
8050 uiout
->text (".\n");
8054 print_no_history_reason (struct ui_out
*uiout
)
8056 uiout
->text ("\nNo more reverse-execution history.\n");
8059 /* Print current location without a level number, if we have changed
8060 functions or hit a breakpoint. Print source line if we have one.
8061 bpstat_print contains the logic deciding in detail what to print,
8062 based on the event(s) that just occurred. */
8065 print_stop_location (struct target_waitstatus
*ws
)
8068 enum print_what source_flag
;
8069 int do_frame_printing
= 1;
8070 struct thread_info
*tp
= inferior_thread ();
8072 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8076 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8077 should) carry around the function and does (or should) use
8078 that when doing a frame comparison. */
8079 if (tp
->control
.stop_step
8080 && frame_id_eq (tp
->control
.step_frame_id
,
8081 get_frame_id (get_current_frame ()))
8082 && (tp
->control
.step_start_function
8083 == find_pc_function (tp
->suspend
.stop_pc
)))
8085 /* Finished step, just print source line. */
8086 source_flag
= SRC_LINE
;
8090 /* Print location and source line. */
8091 source_flag
= SRC_AND_LOC
;
8094 case PRINT_SRC_AND_LOC
:
8095 /* Print location and source line. */
8096 source_flag
= SRC_AND_LOC
;
8098 case PRINT_SRC_ONLY
:
8099 source_flag
= SRC_LINE
;
8102 /* Something bogus. */
8103 source_flag
= SRC_LINE
;
8104 do_frame_printing
= 0;
8107 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8110 /* The behavior of this routine with respect to the source
8112 SRC_LINE: Print only source line
8113 LOCATION: Print only location
8114 SRC_AND_LOC: Print location and source line. */
8115 if (do_frame_printing
)
8116 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8122 print_stop_event (struct ui_out
*uiout
, bool displays
)
8124 struct target_waitstatus last
;
8125 struct thread_info
*tp
;
8127 get_last_target_status (nullptr, nullptr, &last
);
8130 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8132 print_stop_location (&last
);
8134 /* Display the auto-display expressions. */
8139 tp
= inferior_thread ();
8140 if (tp
->thread_fsm
!= NULL
8141 && tp
->thread_fsm
->finished_p ())
8143 struct return_value_info
*rv
;
8145 rv
= tp
->thread_fsm
->return_value ();
8147 print_return_value (uiout
, rv
);
8154 maybe_remove_breakpoints (void)
8156 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8158 if (remove_breakpoints ())
8160 target_terminal::ours_for_output ();
8161 printf_filtered (_("Cannot remove breakpoints because "
8162 "program is no longer writable.\nFurther "
8163 "execution is probably impossible.\n"));
8168 /* The execution context that just caused a normal stop. */
8175 DISABLE_COPY_AND_ASSIGN (stop_context
);
8177 bool changed () const;
8182 /* The event PTID. */
8186 /* If stopp for a thread event, this is the thread that caused the
8188 struct thread_info
*thread
;
8190 /* The inferior that caused the stop. */
8194 /* Initializes a new stop context. If stopped for a thread event, this
8195 takes a strong reference to the thread. */
8197 stop_context::stop_context ()
8199 stop_id
= get_stop_id ();
8200 ptid
= inferior_ptid
;
8201 inf_num
= current_inferior ()->num
;
8203 if (inferior_ptid
!= null_ptid
)
8205 /* Take a strong reference so that the thread can't be deleted
8207 thread
= inferior_thread ();
8214 /* Release a stop context previously created with save_stop_context.
8215 Releases the strong reference to the thread as well. */
8217 stop_context::~stop_context ()
8223 /* Return true if the current context no longer matches the saved stop
8227 stop_context::changed () const
8229 if (ptid
!= inferior_ptid
)
8231 if (inf_num
!= current_inferior ()->num
)
8233 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8235 if (get_stop_id () != stop_id
)
8245 struct target_waitstatus last
;
8247 get_last_target_status (nullptr, nullptr, &last
);
8251 /* If an exception is thrown from this point on, make sure to
8252 propagate GDB's knowledge of the executing state to the
8253 frontend/user running state. A QUIT is an easy exception to see
8254 here, so do this before any filtered output. */
8256 ptid_t finish_ptid
= null_ptid
;
8259 finish_ptid
= minus_one_ptid
;
8260 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8261 || last
.kind
== TARGET_WAITKIND_EXITED
)
8263 /* On some targets, we may still have live threads in the
8264 inferior when we get a process exit event. E.g., for
8265 "checkpoint", when the current checkpoint/fork exits,
8266 linux-fork.c automatically switches to another fork from
8267 within target_mourn_inferior. */
8268 if (inferior_ptid
!= null_ptid
)
8269 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8271 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8272 finish_ptid
= inferior_ptid
;
8274 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8275 if (finish_ptid
!= null_ptid
)
8277 maybe_finish_thread_state
.emplace
8278 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8281 /* As we're presenting a stop, and potentially removing breakpoints,
8282 update the thread list so we can tell whether there are threads
8283 running on the target. With target remote, for example, we can
8284 only learn about new threads when we explicitly update the thread
8285 list. Do this before notifying the interpreters about signal
8286 stops, end of stepping ranges, etc., so that the "new thread"
8287 output is emitted before e.g., "Program received signal FOO",
8288 instead of after. */
8289 update_thread_list ();
8291 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8292 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8294 /* As with the notification of thread events, we want to delay
8295 notifying the user that we've switched thread context until
8296 the inferior actually stops.
8298 There's no point in saying anything if the inferior has exited.
8299 Note that SIGNALLED here means "exited with a signal", not
8300 "received a signal".
8302 Also skip saying anything in non-stop mode. In that mode, as we
8303 don't want GDB to switch threads behind the user's back, to avoid
8304 races where the user is typing a command to apply to thread x,
8305 but GDB switches to thread y before the user finishes entering
8306 the command, fetch_inferior_event installs a cleanup to restore
8307 the current thread back to the thread the user had selected right
8308 after this event is handled, so we're not really switching, only
8309 informing of a stop. */
8311 && previous_inferior_ptid
!= inferior_ptid
8312 && target_has_execution ()
8313 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8314 && last
.kind
!= TARGET_WAITKIND_EXITED
8315 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8317 SWITCH_THRU_ALL_UIS ()
8319 target_terminal::ours_for_output ();
8320 printf_filtered (_("[Switching to %s]\n"),
8321 target_pid_to_str (inferior_ptid
).c_str ());
8322 annotate_thread_changed ();
8324 previous_inferior_ptid
= inferior_ptid
;
8327 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8329 SWITCH_THRU_ALL_UIS ()
8330 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8332 target_terminal::ours_for_output ();
8333 printf_filtered (_("No unwaited-for children left.\n"));
8337 /* Note: this depends on the update_thread_list call above. */
8338 maybe_remove_breakpoints ();
8340 /* If an auto-display called a function and that got a signal,
8341 delete that auto-display to avoid an infinite recursion. */
8343 if (stopped_by_random_signal
)
8344 disable_current_display ();
8346 SWITCH_THRU_ALL_UIS ()
8348 async_enable_stdin ();
8351 /* Let the user/frontend see the threads as stopped. */
8352 maybe_finish_thread_state
.reset ();
8354 /* Select innermost stack frame - i.e., current frame is frame 0,
8355 and current location is based on that. Handle the case where the
8356 dummy call is returning after being stopped. E.g. the dummy call
8357 previously hit a breakpoint. (If the dummy call returns
8358 normally, we won't reach here.) Do this before the stop hook is
8359 run, so that it doesn't get to see the temporary dummy frame,
8360 which is not where we'll present the stop. */
8361 if (has_stack_frames ())
8363 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8365 /* Pop the empty frame that contains the stack dummy. This
8366 also restores inferior state prior to the call (struct
8367 infcall_suspend_state). */
8368 struct frame_info
*frame
= get_current_frame ();
8370 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8372 /* frame_pop calls reinit_frame_cache as the last thing it
8373 does which means there's now no selected frame. */
8376 select_frame (get_current_frame ());
8378 /* Set the current source location. */
8379 set_current_sal_from_frame (get_current_frame ());
8382 /* Look up the hook_stop and run it (CLI internally handles problem
8383 of stop_command's pre-hook not existing). */
8384 if (stop_command
!= NULL
)
8386 stop_context saved_context
;
8390 execute_cmd_pre_hook (stop_command
);
8392 catch (const gdb_exception
&ex
)
8394 exception_fprintf (gdb_stderr
, ex
,
8395 "Error while running hook_stop:\n");
8398 /* If the stop hook resumes the target, then there's no point in
8399 trying to notify about the previous stop; its context is
8400 gone. Likewise if the command switches thread or inferior --
8401 the observers would print a stop for the wrong
8403 if (saved_context
.changed ())
8407 /* Notify observers about the stop. This is where the interpreters
8408 print the stop event. */
8409 if (inferior_ptid
!= null_ptid
)
8410 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8413 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8415 annotate_stopped ();
8417 if (target_has_execution ())
8419 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8420 && last
.kind
!= TARGET_WAITKIND_EXITED
8421 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8422 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8423 Delete any breakpoint that is to be deleted at the next stop. */
8424 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8427 /* Try to get rid of automatically added inferiors that are no
8428 longer needed. Keeping those around slows down things linearly.
8429 Note that this never removes the current inferior. */
8436 signal_stop_state (int signo
)
8438 return signal_stop
[signo
];
8442 signal_print_state (int signo
)
8444 return signal_print
[signo
];
8448 signal_pass_state (int signo
)
8450 return signal_program
[signo
];
8454 signal_cache_update (int signo
)
8458 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8459 signal_cache_update (signo
);
8464 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8465 && signal_print
[signo
] == 0
8466 && signal_program
[signo
] == 1
8467 && signal_catch
[signo
] == 0);
8471 signal_stop_update (int signo
, int state
)
8473 int ret
= signal_stop
[signo
];
8475 signal_stop
[signo
] = state
;
8476 signal_cache_update (signo
);
8481 signal_print_update (int signo
, int state
)
8483 int ret
= signal_print
[signo
];
8485 signal_print
[signo
] = state
;
8486 signal_cache_update (signo
);
8491 signal_pass_update (int signo
, int state
)
8493 int ret
= signal_program
[signo
];
8495 signal_program
[signo
] = state
;
8496 signal_cache_update (signo
);
8500 /* Update the global 'signal_catch' from INFO and notify the
8504 signal_catch_update (const unsigned int *info
)
8508 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8509 signal_catch
[i
] = info
[i
] > 0;
8510 signal_cache_update (-1);
8511 target_pass_signals (signal_pass
);
8515 sig_print_header (void)
8517 printf_filtered (_("Signal Stop\tPrint\tPass "
8518 "to program\tDescription\n"));
8522 sig_print_info (enum gdb_signal oursig
)
8524 const char *name
= gdb_signal_to_name (oursig
);
8525 int name_padding
= 13 - strlen (name
);
8527 if (name_padding
<= 0)
8530 printf_filtered ("%s", name
);
8531 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8532 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8533 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8534 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8535 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8538 /* Specify how various signals in the inferior should be handled. */
8541 handle_command (const char *args
, int from_tty
)
8543 int digits
, wordlen
;
8544 int sigfirst
, siglast
;
8545 enum gdb_signal oursig
;
8550 error_no_arg (_("signal to handle"));
8553 /* Allocate and zero an array of flags for which signals to handle. */
8555 const size_t nsigs
= GDB_SIGNAL_LAST
;
8556 unsigned char sigs
[nsigs
] {};
8558 /* Break the command line up into args. */
8560 gdb_argv
built_argv (args
);
8562 /* Walk through the args, looking for signal oursigs, signal names, and
8563 actions. Signal numbers and signal names may be interspersed with
8564 actions, with the actions being performed for all signals cumulatively
8565 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8567 for (char *arg
: built_argv
)
8569 wordlen
= strlen (arg
);
8570 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8574 sigfirst
= siglast
= -1;
8576 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8578 /* Apply action to all signals except those used by the
8579 debugger. Silently skip those. */
8582 siglast
= nsigs
- 1;
8584 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8586 SET_SIGS (nsigs
, sigs
, signal_stop
);
8587 SET_SIGS (nsigs
, sigs
, signal_print
);
8589 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8591 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8593 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8595 SET_SIGS (nsigs
, sigs
, signal_print
);
8597 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8599 SET_SIGS (nsigs
, sigs
, signal_program
);
8601 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8603 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8605 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8607 SET_SIGS (nsigs
, sigs
, signal_program
);
8609 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8611 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8612 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8614 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8616 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8618 else if (digits
> 0)
8620 /* It is numeric. The numeric signal refers to our own
8621 internal signal numbering from target.h, not to host/target
8622 signal number. This is a feature; users really should be
8623 using symbolic names anyway, and the common ones like
8624 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8626 sigfirst
= siglast
= (int)
8627 gdb_signal_from_command (atoi (arg
));
8628 if (arg
[digits
] == '-')
8631 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8633 if (sigfirst
> siglast
)
8635 /* Bet he didn't figure we'd think of this case... */
8636 std::swap (sigfirst
, siglast
);
8641 oursig
= gdb_signal_from_name (arg
);
8642 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8644 sigfirst
= siglast
= (int) oursig
;
8648 /* Not a number and not a recognized flag word => complain. */
8649 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8653 /* If any signal numbers or symbol names were found, set flags for
8654 which signals to apply actions to. */
8656 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8658 switch ((enum gdb_signal
) signum
)
8660 case GDB_SIGNAL_TRAP
:
8661 case GDB_SIGNAL_INT
:
8662 if (!allsigs
&& !sigs
[signum
])
8664 if (query (_("%s is used by the debugger.\n\
8665 Are you sure you want to change it? "),
8666 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8671 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8675 case GDB_SIGNAL_DEFAULT
:
8676 case GDB_SIGNAL_UNKNOWN
:
8677 /* Make sure that "all" doesn't print these. */
8686 for (int signum
= 0; signum
< nsigs
; signum
++)
8689 signal_cache_update (-1);
8690 target_pass_signals (signal_pass
);
8691 target_program_signals (signal_program
);
8695 /* Show the results. */
8696 sig_print_header ();
8697 for (; signum
< nsigs
; signum
++)
8699 sig_print_info ((enum gdb_signal
) signum
);
8706 /* Complete the "handle" command. */
8709 handle_completer (struct cmd_list_element
*ignore
,
8710 completion_tracker
&tracker
,
8711 const char *text
, const char *word
)
8713 static const char * const keywords
[] =
8727 signal_completer (ignore
, tracker
, text
, word
);
8728 complete_on_enum (tracker
, keywords
, word
, word
);
8732 gdb_signal_from_command (int num
)
8734 if (num
>= 1 && num
<= 15)
8735 return (enum gdb_signal
) num
;
8736 error (_("Only signals 1-15 are valid as numeric signals.\n\
8737 Use \"info signals\" for a list of symbolic signals."));
8740 /* Print current contents of the tables set by the handle command.
8741 It is possible we should just be printing signals actually used
8742 by the current target (but for things to work right when switching
8743 targets, all signals should be in the signal tables). */
8746 info_signals_command (const char *signum_exp
, int from_tty
)
8748 enum gdb_signal oursig
;
8750 sig_print_header ();
8754 /* First see if this is a symbol name. */
8755 oursig
= gdb_signal_from_name (signum_exp
);
8756 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8758 /* No, try numeric. */
8760 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8762 sig_print_info (oursig
);
8766 printf_filtered ("\n");
8767 /* These ugly casts brought to you by the native VAX compiler. */
8768 for (oursig
= GDB_SIGNAL_FIRST
;
8769 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8770 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8774 if (oursig
!= GDB_SIGNAL_UNKNOWN
8775 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8776 sig_print_info (oursig
);
8779 printf_filtered (_("\nUse the \"handle\" command "
8780 "to change these tables.\n"));
8783 /* The $_siginfo convenience variable is a bit special. We don't know
8784 for sure the type of the value until we actually have a chance to
8785 fetch the data. The type can change depending on gdbarch, so it is
8786 also dependent on which thread you have selected.
8788 1. making $_siginfo be an internalvar that creates a new value on
8791 2. making the value of $_siginfo be an lval_computed value. */
8793 /* This function implements the lval_computed support for reading a
8797 siginfo_value_read (struct value
*v
)
8799 LONGEST transferred
;
8801 /* If we can access registers, so can we access $_siginfo. Likewise
8803 validate_registers_access ();
8806 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8808 value_contents_all_raw (v
),
8810 TYPE_LENGTH (value_type (v
)));
8812 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8813 error (_("Unable to read siginfo"));
8816 /* This function implements the lval_computed support for writing a
8820 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8822 LONGEST transferred
;
8824 /* If we can access registers, so can we access $_siginfo. Likewise
8826 validate_registers_access ();
8828 transferred
= target_write (current_top_target (),
8829 TARGET_OBJECT_SIGNAL_INFO
,
8831 value_contents_all_raw (fromval
),
8833 TYPE_LENGTH (value_type (fromval
)));
8835 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8836 error (_("Unable to write siginfo"));
8839 static const struct lval_funcs siginfo_value_funcs
=
8845 /* Return a new value with the correct type for the siginfo object of
8846 the current thread using architecture GDBARCH. Return a void value
8847 if there's no object available. */
8849 static struct value
*
8850 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8853 if (target_has_stack ()
8854 && inferior_ptid
!= null_ptid
8855 && gdbarch_get_siginfo_type_p (gdbarch
))
8857 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8859 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8862 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8866 /* infcall_suspend_state contains state about the program itself like its
8867 registers and any signal it received when it last stopped.
8868 This state must be restored regardless of how the inferior function call
8869 ends (either successfully, or after it hits a breakpoint or signal)
8870 if the program is to properly continue where it left off. */
8872 class infcall_suspend_state
8875 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8876 once the inferior function call has finished. */
8877 infcall_suspend_state (struct gdbarch
*gdbarch
,
8878 const struct thread_info
*tp
,
8879 struct regcache
*regcache
)
8880 : m_thread_suspend (tp
->suspend
),
8881 m_registers (new readonly_detached_regcache (*regcache
))
8883 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8885 if (gdbarch_get_siginfo_type_p (gdbarch
))
8887 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8888 size_t len
= TYPE_LENGTH (type
);
8890 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8892 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8893 siginfo_data
.get (), 0, len
) != len
)
8895 /* Errors ignored. */
8896 siginfo_data
.reset (nullptr);
8902 m_siginfo_gdbarch
= gdbarch
;
8903 m_siginfo_data
= std::move (siginfo_data
);
8907 /* Return a pointer to the stored register state. */
8909 readonly_detached_regcache
*registers () const
8911 return m_registers
.get ();
8914 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8916 void restore (struct gdbarch
*gdbarch
,
8917 struct thread_info
*tp
,
8918 struct regcache
*regcache
) const
8920 tp
->suspend
= m_thread_suspend
;
8922 if (m_siginfo_gdbarch
== gdbarch
)
8924 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8926 /* Errors ignored. */
8927 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8928 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8931 /* The inferior can be gone if the user types "print exit(0)"
8932 (and perhaps other times). */
8933 if (target_has_execution ())
8934 /* NB: The register write goes through to the target. */
8935 regcache
->restore (registers ());
8939 /* How the current thread stopped before the inferior function call was
8941 struct thread_suspend_state m_thread_suspend
;
8943 /* The registers before the inferior function call was executed. */
8944 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8946 /* Format of SIGINFO_DATA or NULL if it is not present. */
8947 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8949 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8950 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8951 content would be invalid. */
8952 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8955 infcall_suspend_state_up
8956 save_infcall_suspend_state ()
8958 struct thread_info
*tp
= inferior_thread ();
8959 struct regcache
*regcache
= get_current_regcache ();
8960 struct gdbarch
*gdbarch
= regcache
->arch ();
8962 infcall_suspend_state_up inf_state
8963 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8965 /* Having saved the current state, adjust the thread state, discarding
8966 any stop signal information. The stop signal is not useful when
8967 starting an inferior function call, and run_inferior_call will not use
8968 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8969 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8974 /* Restore inferior session state to INF_STATE. */
8977 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8979 struct thread_info
*tp
= inferior_thread ();
8980 struct regcache
*regcache
= get_current_regcache ();
8981 struct gdbarch
*gdbarch
= regcache
->arch ();
8983 inf_state
->restore (gdbarch
, tp
, regcache
);
8984 discard_infcall_suspend_state (inf_state
);
8988 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8993 readonly_detached_regcache
*
8994 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8996 return inf_state
->registers ();
8999 /* infcall_control_state contains state regarding gdb's control of the
9000 inferior itself like stepping control. It also contains session state like
9001 the user's currently selected frame. */
9003 struct infcall_control_state
9005 struct thread_control_state thread_control
;
9006 struct inferior_control_state inferior_control
;
9009 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9010 int stopped_by_random_signal
= 0;
9012 /* ID and level of the selected frame when the inferior function
9014 struct frame_id selected_frame_id
{};
9015 int selected_frame_level
= -1;
9018 /* Save all of the information associated with the inferior<==>gdb
9021 infcall_control_state_up
9022 save_infcall_control_state ()
9024 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9025 struct thread_info
*tp
= inferior_thread ();
9026 struct inferior
*inf
= current_inferior ();
9028 inf_status
->thread_control
= tp
->control
;
9029 inf_status
->inferior_control
= inf
->control
;
9031 tp
->control
.step_resume_breakpoint
= NULL
;
9032 tp
->control
.exception_resume_breakpoint
= NULL
;
9034 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9035 chain. If caller's caller is walking the chain, they'll be happier if we
9036 hand them back the original chain when restore_infcall_control_state is
9038 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9041 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9042 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9044 save_selected_frame (&inf_status
->selected_frame_id
,
9045 &inf_status
->selected_frame_level
);
9050 /* Restore inferior session state to INF_STATUS. */
9053 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9055 struct thread_info
*tp
= inferior_thread ();
9056 struct inferior
*inf
= current_inferior ();
9058 if (tp
->control
.step_resume_breakpoint
)
9059 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9061 if (tp
->control
.exception_resume_breakpoint
)
9062 tp
->control
.exception_resume_breakpoint
->disposition
9063 = disp_del_at_next_stop
;
9065 /* Handle the bpstat_copy of the chain. */
9066 bpstat_clear (&tp
->control
.stop_bpstat
);
9068 tp
->control
= inf_status
->thread_control
;
9069 inf
->control
= inf_status
->inferior_control
;
9072 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9073 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9075 if (target_has_stack ())
9077 restore_selected_frame (inf_status
->selected_frame_id
,
9078 inf_status
->selected_frame_level
);
9085 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9087 if (inf_status
->thread_control
.step_resume_breakpoint
)
9088 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9089 = disp_del_at_next_stop
;
9091 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9092 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9093 = disp_del_at_next_stop
;
9095 /* See save_infcall_control_state for info on stop_bpstat. */
9096 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9104 clear_exit_convenience_vars (void)
9106 clear_internalvar (lookup_internalvar ("_exitsignal"));
9107 clear_internalvar (lookup_internalvar ("_exitcode"));
9111 /* User interface for reverse debugging:
9112 Set exec-direction / show exec-direction commands
9113 (returns error unless target implements to_set_exec_direction method). */
9115 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9116 static const char exec_forward
[] = "forward";
9117 static const char exec_reverse
[] = "reverse";
9118 static const char *exec_direction
= exec_forward
;
9119 static const char *const exec_direction_names
[] = {
9126 set_exec_direction_func (const char *args
, int from_tty
,
9127 struct cmd_list_element
*cmd
)
9129 if (target_can_execute_reverse ())
9131 if (!strcmp (exec_direction
, exec_forward
))
9132 execution_direction
= EXEC_FORWARD
;
9133 else if (!strcmp (exec_direction
, exec_reverse
))
9134 execution_direction
= EXEC_REVERSE
;
9138 exec_direction
= exec_forward
;
9139 error (_("Target does not support this operation."));
9144 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9145 struct cmd_list_element
*cmd
, const char *value
)
9147 switch (execution_direction
) {
9149 fprintf_filtered (out
, _("Forward.\n"));
9152 fprintf_filtered (out
, _("Reverse.\n"));
9155 internal_error (__FILE__
, __LINE__
,
9156 _("bogus execution_direction value: %d"),
9157 (int) execution_direction
);
9162 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9163 struct cmd_list_element
*c
, const char *value
)
9165 fprintf_filtered (file
, _("Resuming the execution of threads "
9166 "of all processes is %s.\n"), value
);
9169 /* Implementation of `siginfo' variable. */
9171 static const struct internalvar_funcs siginfo_funcs
=
9178 /* Callback for infrun's target events source. This is marked when a
9179 thread has a pending status to process. */
9182 infrun_async_inferior_event_handler (gdb_client_data data
)
9184 inferior_event_handler (INF_REG_EVENT
);
9191 /* Verify that when two threads with the same ptid exist (from two different
9192 targets) and one of them changes ptid, we only update inferior_ptid if
9193 it is appropriate. */
9196 infrun_thread_ptid_changed ()
9198 gdbarch
*arch
= current_inferior ()->gdbarch
;
9200 /* The thread which inferior_ptid represents changes ptid. */
9202 scoped_restore_current_pspace_and_thread restore
;
9204 scoped_mock_context
<test_target_ops
> target1 (arch
);
9205 scoped_mock_context
<test_target_ops
> target2 (arch
);
9206 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9208 ptid_t
old_ptid (111, 222);
9209 ptid_t
new_ptid (111, 333);
9211 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9212 target1
.mock_thread
.ptid
= old_ptid
;
9213 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9214 target2
.mock_thread
.ptid
= old_ptid
;
9216 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9217 set_current_inferior (&target1
.mock_inferior
);
9219 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9221 gdb_assert (inferior_ptid
== new_ptid
);
9224 /* A thread with the same ptid as inferior_ptid, but from another target,
9227 scoped_restore_current_pspace_and_thread restore
;
9229 scoped_mock_context
<test_target_ops
> target1 (arch
);
9230 scoped_mock_context
<test_target_ops
> target2 (arch
);
9231 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9233 ptid_t
old_ptid (111, 222);
9234 ptid_t
new_ptid (111, 333);
9236 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9237 target1
.mock_thread
.ptid
= old_ptid
;
9238 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9239 target2
.mock_thread
.ptid
= old_ptid
;
9241 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9242 set_current_inferior (&target2
.mock_inferior
);
9244 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9246 gdb_assert (inferior_ptid
== old_ptid
);
9250 } /* namespace selftests */
9252 #endif /* GDB_SELF_TEST */
9254 void _initialize_infrun ();
9256 _initialize_infrun ()
9258 struct cmd_list_element
*c
;
9260 /* Register extra event sources in the event loop. */
9261 infrun_async_inferior_event_token
9262 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9265 add_info ("signals", info_signals_command
, _("\
9266 What debugger does when program gets various signals.\n\
9267 Specify a signal as argument to print info on that signal only."));
9268 add_info_alias ("handle", "signals", 0);
9270 c
= add_com ("handle", class_run
, handle_command
, _("\
9271 Specify how to handle signals.\n\
9272 Usage: handle SIGNAL [ACTIONS]\n\
9273 Args are signals and actions to apply to those signals.\n\
9274 If no actions are specified, the current settings for the specified signals\n\
9275 will be displayed instead.\n\
9277 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9278 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9279 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9280 The special arg \"all\" is recognized to mean all signals except those\n\
9281 used by the debugger, typically SIGTRAP and SIGINT.\n\
9283 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9284 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9285 Stop means reenter debugger if this signal happens (implies print).\n\
9286 Print means print a message if this signal happens.\n\
9287 Pass means let program see this signal; otherwise program doesn't know.\n\
9288 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9289 Pass and Stop may be combined.\n\
9291 Multiple signals may be specified. Signal numbers and signal names\n\
9292 may be interspersed with actions, with the actions being performed for\n\
9293 all signals cumulatively specified."));
9294 set_cmd_completer (c
, handle_completer
);
9297 stop_command
= add_cmd ("stop", class_obscure
,
9298 not_just_help_class_command
, _("\
9299 There is no `stop' command, but you can set a hook on `stop'.\n\
9300 This allows you to set a list of commands to be run each time execution\n\
9301 of the program stops."), &cmdlist
);
9303 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9304 Set inferior debugging."), _("\
9305 Show inferior debugging."), _("\
9306 When non-zero, inferior specific debugging is enabled."),
9309 &setdebuglist
, &showdebuglist
);
9311 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9312 &debug_displaced
, _("\
9313 Set displaced stepping debugging."), _("\
9314 Show displaced stepping debugging."), _("\
9315 When non-zero, displaced stepping specific debugging is enabled."),
9317 show_debug_displaced
,
9318 &setdebuglist
, &showdebuglist
);
9320 add_setshow_boolean_cmd ("non-stop", no_class
,
9322 Set whether gdb controls the inferior in non-stop mode."), _("\
9323 Show whether gdb controls the inferior in non-stop mode."), _("\
9324 When debugging a multi-threaded program and this setting is\n\
9325 off (the default, also called all-stop mode), when one thread stops\n\
9326 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9327 all other threads in the program while you interact with the thread of\n\
9328 interest. When you continue or step a thread, you can allow the other\n\
9329 threads to run, or have them remain stopped, but while you inspect any\n\
9330 thread's state, all threads stop.\n\
9332 In non-stop mode, when one thread stops, other threads can continue\n\
9333 to run freely. You'll be able to step each thread independently,\n\
9334 leave it stopped or free to run as needed."),
9340 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9343 signal_print
[i
] = 1;
9344 signal_program
[i
] = 1;
9345 signal_catch
[i
] = 0;
9348 /* Signals caused by debugger's own actions should not be given to
9349 the program afterwards.
9351 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9352 explicitly specifies that it should be delivered to the target
9353 program. Typically, that would occur when a user is debugging a
9354 target monitor on a simulator: the target monitor sets a
9355 breakpoint; the simulator encounters this breakpoint and halts
9356 the simulation handing control to GDB; GDB, noting that the stop
9357 address doesn't map to any known breakpoint, returns control back
9358 to the simulator; the simulator then delivers the hardware
9359 equivalent of a GDB_SIGNAL_TRAP to the program being
9361 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9362 signal_program
[GDB_SIGNAL_INT
] = 0;
9364 /* Signals that are not errors should not normally enter the debugger. */
9365 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9366 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9367 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9368 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9369 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9370 signal_print
[GDB_SIGNAL_PROF
] = 0;
9371 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9372 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9373 signal_stop
[GDB_SIGNAL_IO
] = 0;
9374 signal_print
[GDB_SIGNAL_IO
] = 0;
9375 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9376 signal_print
[GDB_SIGNAL_POLL
] = 0;
9377 signal_stop
[GDB_SIGNAL_URG
] = 0;
9378 signal_print
[GDB_SIGNAL_URG
] = 0;
9379 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9380 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9381 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9382 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9384 /* These signals are used internally by user-level thread
9385 implementations. (See signal(5) on Solaris.) Like the above
9386 signals, a healthy program receives and handles them as part of
9387 its normal operation. */
9388 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9389 signal_print
[GDB_SIGNAL_LWP
] = 0;
9390 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9391 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9392 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9393 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9394 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9395 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9397 /* Update cached state. */
9398 signal_cache_update (-1);
9400 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9401 &stop_on_solib_events
, _("\
9402 Set stopping for shared library events."), _("\
9403 Show stopping for shared library events."), _("\
9404 If nonzero, gdb will give control to the user when the dynamic linker\n\
9405 notifies gdb of shared library events. The most common event of interest\n\
9406 to the user would be loading/unloading of a new library."),
9407 set_stop_on_solib_events
,
9408 show_stop_on_solib_events
,
9409 &setlist
, &showlist
);
9411 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9412 follow_fork_mode_kind_names
,
9413 &follow_fork_mode_string
, _("\
9414 Set debugger response to a program call of fork or vfork."), _("\
9415 Show debugger response to a program call of fork or vfork."), _("\
9416 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9417 parent - the original process is debugged after a fork\n\
9418 child - the new process is debugged after a fork\n\
9419 The unfollowed process will continue to run.\n\
9420 By default, the debugger will follow the parent process."),
9422 show_follow_fork_mode_string
,
9423 &setlist
, &showlist
);
9425 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9426 follow_exec_mode_names
,
9427 &follow_exec_mode_string
, _("\
9428 Set debugger response to a program call of exec."), _("\
9429 Show debugger response to a program call of exec."), _("\
9430 An exec call replaces the program image of a process.\n\
9432 follow-exec-mode can be:\n\
9434 new - the debugger creates a new inferior and rebinds the process\n\
9435 to this new inferior. The program the process was running before\n\
9436 the exec call can be restarted afterwards by restarting the original\n\
9439 same - the debugger keeps the process bound to the same inferior.\n\
9440 The new executable image replaces the previous executable loaded in\n\
9441 the inferior. Restarting the inferior after the exec call restarts\n\
9442 the executable the process was running after the exec call.\n\
9444 By default, the debugger will use the same inferior."),
9446 show_follow_exec_mode_string
,
9447 &setlist
, &showlist
);
9449 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9450 scheduler_enums
, &scheduler_mode
, _("\
9451 Set mode for locking scheduler during execution."), _("\
9452 Show mode for locking scheduler during execution."), _("\
9453 off == no locking (threads may preempt at any time)\n\
9454 on == full locking (no thread except the current thread may run)\n\
9455 This applies to both normal execution and replay mode.\n\
9456 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9457 In this mode, other threads may run during other commands.\n\
9458 This applies to both normal execution and replay mode.\n\
9459 replay == scheduler locked in replay mode and unlocked during normal execution."),
9460 set_schedlock_func
, /* traps on target vector */
9461 show_scheduler_mode
,
9462 &setlist
, &showlist
);
9464 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9465 Set mode for resuming threads of all processes."), _("\
9466 Show mode for resuming threads of all processes."), _("\
9467 When on, execution commands (such as 'continue' or 'next') resume all\n\
9468 threads of all processes. When off (which is the default), execution\n\
9469 commands only resume the threads of the current process. The set of\n\
9470 threads that are resumed is further refined by the scheduler-locking\n\
9471 mode (see help set scheduler-locking)."),
9473 show_schedule_multiple
,
9474 &setlist
, &showlist
);
9476 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9477 Set mode of the step operation."), _("\
9478 Show mode of the step operation."), _("\
9479 When set, doing a step over a function without debug line information\n\
9480 will stop at the first instruction of that function. Otherwise, the\n\
9481 function is skipped and the step command stops at a different source line."),
9483 show_step_stop_if_no_debug
,
9484 &setlist
, &showlist
);
9486 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9487 &can_use_displaced_stepping
, _("\
9488 Set debugger's willingness to use displaced stepping."), _("\
9489 Show debugger's willingness to use displaced stepping."), _("\
9490 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9491 supported by the target architecture. If off, gdb will not use displaced\n\
9492 stepping to step over breakpoints, even if such is supported by the target\n\
9493 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9494 if the target architecture supports it and non-stop mode is active, but will not\n\
9495 use it in all-stop mode (see help set non-stop)."),
9497 show_can_use_displaced_stepping
,
9498 &setlist
, &showlist
);
9500 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9501 &exec_direction
, _("Set direction of execution.\n\
9502 Options are 'forward' or 'reverse'."),
9503 _("Show direction of execution (forward/reverse)."),
9504 _("Tells gdb whether to execute forward or backward."),
9505 set_exec_direction_func
, show_exec_direction_func
,
9506 &setlist
, &showlist
);
9508 /* Set/show detach-on-fork: user-settable mode. */
9510 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9511 Set whether gdb will detach the child of a fork."), _("\
9512 Show whether gdb will detach the child of a fork."), _("\
9513 Tells gdb whether to detach the child of a fork."),
9514 NULL
, NULL
, &setlist
, &showlist
);
9516 /* Set/show disable address space randomization mode. */
9518 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9519 &disable_randomization
, _("\
9520 Set disabling of debuggee's virtual address space randomization."), _("\
9521 Show disabling of debuggee's virtual address space randomization."), _("\
9522 When this mode is on (which is the default), randomization of the virtual\n\
9523 address space is disabled. Standalone programs run with the randomization\n\
9524 enabled by default on some platforms."),
9525 &set_disable_randomization
,
9526 &show_disable_randomization
,
9527 &setlist
, &showlist
);
9529 /* ptid initializations */
9530 inferior_ptid
= null_ptid
;
9531 target_last_wait_ptid
= minus_one_ptid
;
9533 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9534 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9535 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9536 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9538 /* Explicitly create without lookup, since that tries to create a
9539 value with a void typed value, and when we get here, gdbarch
9540 isn't initialized yet. At this point, we're quite sure there
9541 isn't another convenience variable of the same name. */
9542 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9544 add_setshow_boolean_cmd ("observer", no_class
,
9545 &observer_mode_1
, _("\
9546 Set whether gdb controls the inferior in observer mode."), _("\
9547 Show whether gdb controls the inferior in observer mode."), _("\
9548 In observer mode, GDB can get data from the inferior, but not\n\
9549 affect its execution. Registers and memory may not be changed,\n\
9550 breakpoints may not be set, and the program cannot be interrupted\n\
9558 selftests::register_test ("infrun_thread_ptid_changed",
9559 selftests::infrun_thread_ptid_changed
);