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 struct displaced_step_inferior_state
*displaced
;
2464 /* Update pc to reflect the new address from which we will
2465 execute instructions due to displaced stepping. */
2466 pc
= regcache_read_pc (get_thread_regcache (tp
));
2468 displaced
= get_displaced_stepping_state (tp
->inf
);
2469 step
= gdbarch_displaced_step_hw_singlestep
2470 (gdbarch
, displaced
->step_closure
.get ());
2474 /* Do we need to do it the hard way, w/temp breakpoints? */
2476 step
= maybe_software_singlestep (gdbarch
, pc
);
2478 /* Currently, our software single-step implementation leads to different
2479 results than hardware single-stepping in one situation: when stepping
2480 into delivering a signal which has an associated signal handler,
2481 hardware single-step will stop at the first instruction of the handler,
2482 while software single-step will simply skip execution of the handler.
2484 For now, this difference in behavior is accepted since there is no
2485 easy way to actually implement single-stepping into a signal handler
2486 without kernel support.
2488 However, there is one scenario where this difference leads to follow-on
2489 problems: if we're stepping off a breakpoint by removing all breakpoints
2490 and then single-stepping. In this case, the software single-step
2491 behavior means that even if there is a *breakpoint* in the signal
2492 handler, GDB still would not stop.
2494 Fortunately, we can at least fix this particular issue. We detect
2495 here the case where we are about to deliver a signal while software
2496 single-stepping with breakpoints removed. In this situation, we
2497 revert the decisions to remove all breakpoints and insert single-
2498 step breakpoints, and instead we install a step-resume breakpoint
2499 at the current address, deliver the signal without stepping, and
2500 once we arrive back at the step-resume breakpoint, actually step
2501 over the breakpoint we originally wanted to step over. */
2502 if (thread_has_single_step_breakpoints_set (tp
)
2503 && sig
!= GDB_SIGNAL_0
2504 && step_over_info_valid_p ())
2506 /* If we have nested signals or a pending signal is delivered
2507 immediately after a handler returns, might already have
2508 a step-resume breakpoint set on the earlier handler. We cannot
2509 set another step-resume breakpoint; just continue on until the
2510 original breakpoint is hit. */
2511 if (tp
->control
.step_resume_breakpoint
== NULL
)
2513 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2514 tp
->step_after_step_resume_breakpoint
= 1;
2517 delete_single_step_breakpoints (tp
);
2519 clear_step_over_info ();
2520 tp
->control
.trap_expected
= 0;
2522 insert_breakpoints ();
2525 /* If STEP is set, it's a request to use hardware stepping
2526 facilities. But in that case, we should never
2527 use singlestep breakpoint. */
2528 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2530 /* Decide the set of threads to ask the target to resume. */
2531 if (tp
->control
.trap_expected
)
2533 /* We're allowing a thread to run past a breakpoint it has
2534 hit, either by single-stepping the thread with the breakpoint
2535 removed, or by displaced stepping, with the breakpoint inserted.
2536 In the former case, we need to single-step only this thread,
2537 and keep others stopped, as they can miss this breakpoint if
2538 allowed to run. That's not really a problem for displaced
2539 stepping, but, we still keep other threads stopped, in case
2540 another thread is also stopped for a breakpoint waiting for
2541 its turn in the displaced stepping queue. */
2542 resume_ptid
= inferior_ptid
;
2545 resume_ptid
= internal_resume_ptid (user_step
);
2547 if (execution_direction
!= EXEC_REVERSE
2548 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2550 /* There are two cases where we currently need to step a
2551 breakpoint instruction when we have a signal to deliver:
2553 - See handle_signal_stop where we handle random signals that
2554 could take out us out of the stepping range. Normally, in
2555 that case we end up continuing (instead of stepping) over the
2556 signal handler with a breakpoint at PC, but there are cases
2557 where we should _always_ single-step, even if we have a
2558 step-resume breakpoint, like when a software watchpoint is
2559 set. Assuming single-stepping and delivering a signal at the
2560 same time would takes us to the signal handler, then we could
2561 have removed the breakpoint at PC to step over it. However,
2562 some hardware step targets (like e.g., Mac OS) can't step
2563 into signal handlers, and for those, we need to leave the
2564 breakpoint at PC inserted, as otherwise if the handler
2565 recurses and executes PC again, it'll miss the breakpoint.
2566 So we leave the breakpoint inserted anyway, but we need to
2567 record that we tried to step a breakpoint instruction, so
2568 that adjust_pc_after_break doesn't end up confused.
2570 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2571 in one thread after another thread that was stepping had been
2572 momentarily paused for a step-over. When we re-resume the
2573 stepping thread, it may be resumed from that address with a
2574 breakpoint that hasn't trapped yet. Seen with
2575 gdb.threads/non-stop-fair-events.exp, on targets that don't
2576 do displaced stepping. */
2578 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2579 target_pid_to_str (tp
->ptid
).c_str ());
2581 tp
->stepped_breakpoint
= 1;
2583 /* Most targets can step a breakpoint instruction, thus
2584 executing it normally. But if this one cannot, just
2585 continue and we will hit it anyway. */
2586 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2591 && tp
->control
.trap_expected
2592 && use_displaced_stepping (tp
)
2593 && !step_over_info_valid_p ())
2595 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2596 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2597 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2600 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2601 paddress (resume_gdbarch
, actual_pc
));
2602 read_memory (actual_pc
, buf
, sizeof (buf
));
2603 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2606 if (tp
->control
.may_range_step
)
2608 /* If we're resuming a thread with the PC out of the step
2609 range, then we're doing some nested/finer run control
2610 operation, like stepping the thread out of the dynamic
2611 linker or the displaced stepping scratch pad. We
2612 shouldn't have allowed a range step then. */
2613 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2616 do_target_resume (resume_ptid
, step
, sig
);
2620 /* Resume the inferior. SIG is the signal to give the inferior
2621 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2622 rolls back state on error. */
2625 resume (gdb_signal sig
)
2631 catch (const gdb_exception
&ex
)
2633 /* If resuming is being aborted for any reason, delete any
2634 single-step breakpoint resume_1 may have created, to avoid
2635 confusing the following resumption, and to avoid leaving
2636 single-step breakpoints perturbing other threads, in case
2637 we're running in non-stop mode. */
2638 if (inferior_ptid
!= null_ptid
)
2639 delete_single_step_breakpoints (inferior_thread ());
2649 /* Counter that tracks number of user visible stops. This can be used
2650 to tell whether a command has proceeded the inferior past the
2651 current location. This allows e.g., inferior function calls in
2652 breakpoint commands to not interrupt the command list. When the
2653 call finishes successfully, the inferior is standing at the same
2654 breakpoint as if nothing happened (and so we don't call
2656 static ULONGEST current_stop_id
;
2663 return current_stop_id
;
2666 /* Called when we report a user visible stop. */
2674 /* Clear out all variables saying what to do when inferior is continued.
2675 First do this, then set the ones you want, then call `proceed'. */
2678 clear_proceed_status_thread (struct thread_info
*tp
)
2680 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2682 /* If we're starting a new sequence, then the previous finished
2683 single-step is no longer relevant. */
2684 if (tp
->suspend
.waitstatus_pending_p
)
2686 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2688 infrun_debug_printf ("pending event of %s was a finished step. "
2690 target_pid_to_str (tp
->ptid
).c_str ());
2692 tp
->suspend
.waitstatus_pending_p
= 0;
2693 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2698 ("thread %s has pending wait status %s (currently_stepping=%d).",
2699 target_pid_to_str (tp
->ptid
).c_str (),
2700 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2701 currently_stepping (tp
));
2705 /* If this signal should not be seen by program, give it zero.
2706 Used for debugging signals. */
2707 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2708 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2710 delete tp
->thread_fsm
;
2711 tp
->thread_fsm
= NULL
;
2713 tp
->control
.trap_expected
= 0;
2714 tp
->control
.step_range_start
= 0;
2715 tp
->control
.step_range_end
= 0;
2716 tp
->control
.may_range_step
= 0;
2717 tp
->control
.step_frame_id
= null_frame_id
;
2718 tp
->control
.step_stack_frame_id
= null_frame_id
;
2719 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2720 tp
->control
.step_start_function
= NULL
;
2721 tp
->stop_requested
= 0;
2723 tp
->control
.stop_step
= 0;
2725 tp
->control
.proceed_to_finish
= 0;
2727 tp
->control
.stepping_command
= 0;
2729 /* Discard any remaining commands or status from previous stop. */
2730 bpstat_clear (&tp
->control
.stop_bpstat
);
2734 clear_proceed_status (int step
)
2736 /* With scheduler-locking replay, stop replaying other threads if we're
2737 not replaying the user-visible resume ptid.
2739 This is a convenience feature to not require the user to explicitly
2740 stop replaying the other threads. We're assuming that the user's
2741 intent is to resume tracing the recorded process. */
2742 if (!non_stop
&& scheduler_mode
== schedlock_replay
2743 && target_record_is_replaying (minus_one_ptid
)
2744 && !target_record_will_replay (user_visible_resume_ptid (step
),
2745 execution_direction
))
2746 target_record_stop_replaying ();
2748 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2750 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2751 process_stratum_target
*resume_target
2752 = user_visible_resume_target (resume_ptid
);
2754 /* In all-stop mode, delete the per-thread status of all threads
2755 we're about to resume, implicitly and explicitly. */
2756 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2757 clear_proceed_status_thread (tp
);
2760 if (inferior_ptid
!= null_ptid
)
2762 struct inferior
*inferior
;
2766 /* If in non-stop mode, only delete the per-thread status of
2767 the current thread. */
2768 clear_proceed_status_thread (inferior_thread ());
2771 inferior
= current_inferior ();
2772 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2775 gdb::observers::about_to_proceed
.notify ();
2778 /* Returns true if TP is still stopped at a breakpoint that needs
2779 stepping-over in order to make progress. If the breakpoint is gone
2780 meanwhile, we can skip the whole step-over dance. */
2783 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2785 if (tp
->stepping_over_breakpoint
)
2787 struct regcache
*regcache
= get_thread_regcache (tp
);
2789 if (breakpoint_here_p (regcache
->aspace (),
2790 regcache_read_pc (regcache
))
2791 == ordinary_breakpoint_here
)
2794 tp
->stepping_over_breakpoint
= 0;
2800 /* Check whether thread TP still needs to start a step-over in order
2801 to make progress when resumed. Returns an bitwise or of enum
2802 step_over_what bits, indicating what needs to be stepped over. */
2804 static step_over_what
2805 thread_still_needs_step_over (struct thread_info
*tp
)
2807 step_over_what what
= 0;
2809 if (thread_still_needs_step_over_bp (tp
))
2810 what
|= STEP_OVER_BREAKPOINT
;
2812 if (tp
->stepping_over_watchpoint
2813 && !target_have_steppable_watchpoint ())
2814 what
|= STEP_OVER_WATCHPOINT
;
2819 /* Returns true if scheduler locking applies. STEP indicates whether
2820 we're about to do a step/next-like command to a thread. */
2823 schedlock_applies (struct thread_info
*tp
)
2825 return (scheduler_mode
== schedlock_on
2826 || (scheduler_mode
== schedlock_step
2827 && tp
->control
.stepping_command
)
2828 || (scheduler_mode
== schedlock_replay
2829 && target_record_will_replay (minus_one_ptid
,
2830 execution_direction
)));
2833 /* Calls target_commit_resume on all targets. */
2836 commit_resume_all_targets ()
2838 scoped_restore_current_thread restore_thread
;
2840 /* Map between process_target and a representative inferior. This
2841 is to avoid committing a resume in the same target more than
2842 once. Resumptions must be idempotent, so this is an
2844 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2846 for (inferior
*inf
: all_non_exited_inferiors ())
2847 if (inf
->has_execution ())
2848 conn_inf
[inf
->process_target ()] = inf
;
2850 for (const auto &ci
: conn_inf
)
2852 inferior
*inf
= ci
.second
;
2853 switch_to_inferior_no_thread (inf
);
2854 target_commit_resume ();
2858 /* Check that all the targets we're about to resume are in non-stop
2859 mode. Ideally, we'd only care whether all targets support
2860 target-async, but we're not there yet. E.g., stop_all_threads
2861 doesn't know how to handle all-stop targets. Also, the remote
2862 protocol in all-stop mode is synchronous, irrespective of
2863 target-async, which means that things like a breakpoint re-set
2864 triggered by one target would try to read memory from all targets
2868 check_multi_target_resumption (process_stratum_target
*resume_target
)
2870 if (!non_stop
&& resume_target
== nullptr)
2872 scoped_restore_current_thread restore_thread
;
2874 /* This is used to track whether we're resuming more than one
2876 process_stratum_target
*first_connection
= nullptr;
2878 /* The first inferior we see with a target that does not work in
2879 always-non-stop mode. */
2880 inferior
*first_not_non_stop
= nullptr;
2882 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2884 switch_to_inferior_no_thread (inf
);
2886 if (!target_has_execution ())
2889 process_stratum_target
*proc_target
2890 = current_inferior ()->process_target();
2892 if (!target_is_non_stop_p ())
2893 first_not_non_stop
= inf
;
2895 if (first_connection
== nullptr)
2896 first_connection
= proc_target
;
2897 else if (first_connection
!= proc_target
2898 && first_not_non_stop
!= nullptr)
2900 switch_to_inferior_no_thread (first_not_non_stop
);
2902 proc_target
= current_inferior ()->process_target();
2904 error (_("Connection %d (%s) does not support "
2905 "multi-target resumption."),
2906 proc_target
->connection_number
,
2907 make_target_connection_string (proc_target
).c_str ());
2913 /* Basic routine for continuing the program in various fashions.
2915 ADDR is the address to resume at, or -1 for resume where stopped.
2916 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2917 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2919 You should call clear_proceed_status before calling proceed. */
2922 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2924 struct regcache
*regcache
;
2925 struct gdbarch
*gdbarch
;
2927 struct execution_control_state ecss
;
2928 struct execution_control_state
*ecs
= &ecss
;
2931 /* If we're stopped at a fork/vfork, follow the branch set by the
2932 "set follow-fork-mode" command; otherwise, we'll just proceed
2933 resuming the current thread. */
2934 if (!follow_fork ())
2936 /* The target for some reason decided not to resume. */
2938 if (target_can_async_p ())
2939 inferior_event_handler (INF_EXEC_COMPLETE
);
2943 /* We'll update this if & when we switch to a new thread. */
2944 previous_inferior_ptid
= inferior_ptid
;
2946 regcache
= get_current_regcache ();
2947 gdbarch
= regcache
->arch ();
2948 const address_space
*aspace
= regcache
->aspace ();
2950 pc
= regcache_read_pc_protected (regcache
);
2952 thread_info
*cur_thr
= inferior_thread ();
2954 /* Fill in with reasonable starting values. */
2955 init_thread_stepping_state (cur_thr
);
2957 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2960 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2961 process_stratum_target
*resume_target
2962 = user_visible_resume_target (resume_ptid
);
2964 check_multi_target_resumption (resume_target
);
2966 if (addr
== (CORE_ADDR
) -1)
2968 if (pc
== cur_thr
->suspend
.stop_pc
2969 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2970 && execution_direction
!= EXEC_REVERSE
)
2971 /* There is a breakpoint at the address we will resume at,
2972 step one instruction before inserting breakpoints so that
2973 we do not stop right away (and report a second hit at this
2976 Note, we don't do this in reverse, because we won't
2977 actually be executing the breakpoint insn anyway.
2978 We'll be (un-)executing the previous instruction. */
2979 cur_thr
->stepping_over_breakpoint
= 1;
2980 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2981 && gdbarch_single_step_through_delay (gdbarch
,
2982 get_current_frame ()))
2983 /* We stepped onto an instruction that needs to be stepped
2984 again before re-inserting the breakpoint, do so. */
2985 cur_thr
->stepping_over_breakpoint
= 1;
2989 regcache_write_pc (regcache
, addr
);
2992 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2993 cur_thr
->suspend
.stop_signal
= siggnal
;
2995 /* If an exception is thrown from this point on, make sure to
2996 propagate GDB's knowledge of the executing state to the
2997 frontend/user running state. */
2998 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3000 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3001 threads (e.g., we might need to set threads stepping over
3002 breakpoints first), from the user/frontend's point of view, all
3003 threads in RESUME_PTID are now running. Unless we're calling an
3004 inferior function, as in that case we pretend the inferior
3005 doesn't run at all. */
3006 if (!cur_thr
->control
.in_infcall
)
3007 set_running (resume_target
, resume_ptid
, true);
3009 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3010 gdb_signal_to_symbol_string (siggnal
));
3012 annotate_starting ();
3014 /* Make sure that output from GDB appears before output from the
3016 gdb_flush (gdb_stdout
);
3018 /* Since we've marked the inferior running, give it the terminal. A
3019 QUIT/Ctrl-C from here on is forwarded to the target (which can
3020 still detect attempts to unblock a stuck connection with repeated
3021 Ctrl-C from within target_pass_ctrlc). */
3022 target_terminal::inferior ();
3024 /* In a multi-threaded task we may select another thread and
3025 then continue or step.
3027 But if a thread that we're resuming had stopped at a breakpoint,
3028 it will immediately cause another breakpoint stop without any
3029 execution (i.e. it will report a breakpoint hit incorrectly). So
3030 we must step over it first.
3032 Look for threads other than the current (TP) that reported a
3033 breakpoint hit and haven't been resumed yet since. */
3035 /* If scheduler locking applies, we can avoid iterating over all
3037 if (!non_stop
&& !schedlock_applies (cur_thr
))
3039 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3042 switch_to_thread_no_regs (tp
);
3044 /* Ignore the current thread here. It's handled
3049 if (!thread_still_needs_step_over (tp
))
3052 gdb_assert (!thread_is_in_step_over_chain (tp
));
3054 infrun_debug_printf ("need to step-over [%s] first",
3055 target_pid_to_str (tp
->ptid
).c_str ());
3057 thread_step_over_chain_enqueue (tp
);
3060 switch_to_thread (cur_thr
);
3063 /* Enqueue the current thread last, so that we move all other
3064 threads over their breakpoints first. */
3065 if (cur_thr
->stepping_over_breakpoint
)
3066 thread_step_over_chain_enqueue (cur_thr
);
3068 /* If the thread isn't started, we'll still need to set its prev_pc,
3069 so that switch_back_to_stepped_thread knows the thread hasn't
3070 advanced. Must do this before resuming any thread, as in
3071 all-stop/remote, once we resume we can't send any other packet
3072 until the target stops again. */
3073 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3076 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3078 started
= start_step_over ();
3080 if (step_over_info_valid_p ())
3082 /* Either this thread started a new in-line step over, or some
3083 other thread was already doing one. In either case, don't
3084 resume anything else until the step-over is finished. */
3086 else if (started
&& !target_is_non_stop_p ())
3088 /* A new displaced stepping sequence was started. In all-stop,
3089 we can't talk to the target anymore until it next stops. */
3091 else if (!non_stop
&& target_is_non_stop_p ())
3093 /* In all-stop, but the target is always in non-stop mode.
3094 Start all other threads that are implicitly resumed too. */
3095 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3098 switch_to_thread_no_regs (tp
);
3100 if (!tp
->inf
->has_execution ())
3102 infrun_debug_printf ("[%s] target has no execution",
3103 target_pid_to_str (tp
->ptid
).c_str ());
3109 infrun_debug_printf ("[%s] resumed",
3110 target_pid_to_str (tp
->ptid
).c_str ());
3111 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3115 if (thread_is_in_step_over_chain (tp
))
3117 infrun_debug_printf ("[%s] needs step-over",
3118 target_pid_to_str (tp
->ptid
).c_str ());
3122 infrun_debug_printf ("resuming %s",
3123 target_pid_to_str (tp
->ptid
).c_str ());
3125 reset_ecs (ecs
, tp
);
3126 switch_to_thread (tp
);
3127 keep_going_pass_signal (ecs
);
3128 if (!ecs
->wait_some_more
)
3129 error (_("Command aborted."));
3132 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3134 /* The thread wasn't started, and isn't queued, run it now. */
3135 reset_ecs (ecs
, cur_thr
);
3136 switch_to_thread (cur_thr
);
3137 keep_going_pass_signal (ecs
);
3138 if (!ecs
->wait_some_more
)
3139 error (_("Command aborted."));
3143 commit_resume_all_targets ();
3145 finish_state
.release ();
3147 /* If we've switched threads above, switch back to the previously
3148 current thread. We don't want the user to see a different
3150 switch_to_thread (cur_thr
);
3152 /* Tell the event loop to wait for it to stop. If the target
3153 supports asynchronous execution, it'll do this from within
3155 if (!target_can_async_p ())
3156 mark_async_event_handler (infrun_async_inferior_event_token
);
3160 /* Start remote-debugging of a machine over a serial link. */
3163 start_remote (int from_tty
)
3165 inferior
*inf
= current_inferior ();
3166 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3168 /* Always go on waiting for the target, regardless of the mode. */
3169 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3170 indicate to wait_for_inferior that a target should timeout if
3171 nothing is returned (instead of just blocking). Because of this,
3172 targets expecting an immediate response need to, internally, set
3173 things up so that the target_wait() is forced to eventually
3175 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3176 differentiate to its caller what the state of the target is after
3177 the initial open has been performed. Here we're assuming that
3178 the target has stopped. It should be possible to eventually have
3179 target_open() return to the caller an indication that the target
3180 is currently running and GDB state should be set to the same as
3181 for an async run. */
3182 wait_for_inferior (inf
);
3184 /* Now that the inferior has stopped, do any bookkeeping like
3185 loading shared libraries. We want to do this before normal_stop,
3186 so that the displayed frame is up to date. */
3187 post_create_inferior (from_tty
);
3192 /* Initialize static vars when a new inferior begins. */
3195 init_wait_for_inferior (void)
3197 /* These are meaningless until the first time through wait_for_inferior. */
3199 breakpoint_init_inferior (inf_starting
);
3201 clear_proceed_status (0);
3203 nullify_last_target_wait_ptid ();
3205 previous_inferior_ptid
= inferior_ptid
;
3210 static void handle_inferior_event (struct execution_control_state
*ecs
);
3212 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3213 struct execution_control_state
*ecs
);
3214 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3215 struct execution_control_state
*ecs
);
3216 static void handle_signal_stop (struct execution_control_state
*ecs
);
3217 static void check_exception_resume (struct execution_control_state
*,
3218 struct frame_info
*);
3220 static void end_stepping_range (struct execution_control_state
*ecs
);
3221 static void stop_waiting (struct execution_control_state
*ecs
);
3222 static void keep_going (struct execution_control_state
*ecs
);
3223 static void process_event_stop_test (struct execution_control_state
*ecs
);
3224 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3226 /* This function is attached as a "thread_stop_requested" observer.
3227 Cleanup local state that assumed the PTID was to be resumed, and
3228 report the stop to the frontend. */
3231 infrun_thread_stop_requested (ptid_t ptid
)
3233 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3235 /* PTID was requested to stop. If the thread was already stopped,
3236 but the user/frontend doesn't know about that yet (e.g., the
3237 thread had been temporarily paused for some step-over), set up
3238 for reporting the stop now. */
3239 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3241 if (tp
->state
!= THREAD_RUNNING
)
3246 /* Remove matching threads from the step-over queue, so
3247 start_step_over doesn't try to resume them
3249 if (thread_is_in_step_over_chain (tp
))
3250 thread_step_over_chain_remove (tp
);
3252 /* If the thread is stopped, but the user/frontend doesn't
3253 know about that yet, queue a pending event, as if the
3254 thread had just stopped now. Unless the thread already had
3256 if (!tp
->suspend
.waitstatus_pending_p
)
3258 tp
->suspend
.waitstatus_pending_p
= 1;
3259 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3260 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3263 /* Clear the inline-frame state, since we're re-processing the
3265 clear_inline_frame_state (tp
);
3267 /* If this thread was paused because some other thread was
3268 doing an inline-step over, let that finish first. Once
3269 that happens, we'll restart all threads and consume pending
3270 stop events then. */
3271 if (step_over_info_valid_p ())
3274 /* Otherwise we can process the (new) pending event now. Set
3275 it so this pending event is considered by
3282 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3284 if (target_last_proc_target
== tp
->inf
->process_target ()
3285 && target_last_wait_ptid
== tp
->ptid
)
3286 nullify_last_target_wait_ptid ();
3289 /* Delete the step resume, single-step and longjmp/exception resume
3290 breakpoints of TP. */
3293 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3295 delete_step_resume_breakpoint (tp
);
3296 delete_exception_resume_breakpoint (tp
);
3297 delete_single_step_breakpoints (tp
);
3300 /* If the target still has execution, call FUNC for each thread that
3301 just stopped. In all-stop, that's all the non-exited threads; in
3302 non-stop, that's the current thread, only. */
3304 typedef void (*for_each_just_stopped_thread_callback_func
)
3305 (struct thread_info
*tp
);
3308 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3310 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3313 if (target_is_non_stop_p ())
3315 /* If in non-stop mode, only the current thread stopped. */
3316 func (inferior_thread ());
3320 /* In all-stop mode, all threads have stopped. */
3321 for (thread_info
*tp
: all_non_exited_threads ())
3326 /* Delete the step resume and longjmp/exception resume breakpoints of
3327 the threads that just stopped. */
3330 delete_just_stopped_threads_infrun_breakpoints (void)
3332 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3335 /* Delete the single-step breakpoints of the threads that just
3339 delete_just_stopped_threads_single_step_breakpoints (void)
3341 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3347 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3348 const struct target_waitstatus
*ws
)
3350 std::string status_string
= target_waitstatus_to_string (ws
);
3353 /* The text is split over several lines because it was getting too long.
3354 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3355 output as a unit; we want only one timestamp printed if debug_timestamp
3358 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3361 waiton_ptid
.tid ());
3362 if (waiton_ptid
.pid () != -1)
3363 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3364 stb
.printf (", status) =\n");
3365 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3369 target_pid_to_str (result_ptid
).c_str ());
3370 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3372 /* This uses %s in part to handle %'s in the text, but also to avoid
3373 a gcc error: the format attribute requires a string literal. */
3374 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3377 /* Select a thread at random, out of those which are resumed and have
3380 static struct thread_info
*
3381 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3385 auto has_event
= [&] (thread_info
*tp
)
3387 return (tp
->ptid
.matches (waiton_ptid
)
3389 && tp
->suspend
.waitstatus_pending_p
);
3392 /* First see how many events we have. Count only resumed threads
3393 that have an event pending. */
3394 for (thread_info
*tp
: inf
->non_exited_threads ())
3398 if (num_events
== 0)
3401 /* Now randomly pick a thread out of those that have had events. */
3402 int random_selector
= (int) ((num_events
* (double) rand ())
3403 / (RAND_MAX
+ 1.0));
3406 infrun_debug_printf ("Found %d events, selecting #%d",
3407 num_events
, random_selector
);
3409 /* Select the Nth thread that has had an event. */
3410 for (thread_info
*tp
: inf
->non_exited_threads ())
3412 if (random_selector
-- == 0)
3415 gdb_assert_not_reached ("event thread not found");
3418 /* Wrapper for target_wait that first checks whether threads have
3419 pending statuses to report before actually asking the target for
3420 more events. INF is the inferior we're using to call target_wait
3424 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3425 target_waitstatus
*status
, target_wait_flags options
)
3428 struct thread_info
*tp
;
3430 /* We know that we are looking for an event in the target of inferior
3431 INF, but we don't know which thread the event might come from. As
3432 such we want to make sure that INFERIOR_PTID is reset so that none of
3433 the wait code relies on it - doing so is always a mistake. */
3434 switch_to_inferior_no_thread (inf
);
3436 /* First check if there is a resumed thread with a wait status
3438 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3440 tp
= random_pending_event_thread (inf
, ptid
);
3444 infrun_debug_printf ("Waiting for specific thread %s.",
3445 target_pid_to_str (ptid
).c_str ());
3447 /* We have a specific thread to check. */
3448 tp
= find_thread_ptid (inf
, ptid
);
3449 gdb_assert (tp
!= NULL
);
3450 if (!tp
->suspend
.waitstatus_pending_p
)
3455 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3456 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3458 struct regcache
*regcache
= get_thread_regcache (tp
);
3459 struct gdbarch
*gdbarch
= regcache
->arch ();
3463 pc
= regcache_read_pc (regcache
);
3465 if (pc
!= tp
->suspend
.stop_pc
)
3467 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3468 target_pid_to_str (tp
->ptid
).c_str (),
3469 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3470 paddress (gdbarch
, pc
));
3473 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3475 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3476 target_pid_to_str (tp
->ptid
).c_str (),
3477 paddress (gdbarch
, pc
));
3484 infrun_debug_printf ("pending event of %s cancelled.",
3485 target_pid_to_str (tp
->ptid
).c_str ());
3487 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3488 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3494 infrun_debug_printf ("Using pending wait status %s for %s.",
3495 target_waitstatus_to_string
3496 (&tp
->suspend
.waitstatus
).c_str (),
3497 target_pid_to_str (tp
->ptid
).c_str ());
3499 /* Now that we've selected our final event LWP, un-adjust its PC
3500 if it was a software breakpoint (and the target doesn't
3501 always adjust the PC itself). */
3502 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3503 && !target_supports_stopped_by_sw_breakpoint ())
3505 struct regcache
*regcache
;
3506 struct gdbarch
*gdbarch
;
3509 regcache
= get_thread_regcache (tp
);
3510 gdbarch
= regcache
->arch ();
3512 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3517 pc
= regcache_read_pc (regcache
);
3518 regcache_write_pc (regcache
, pc
+ decr_pc
);
3522 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3523 *status
= tp
->suspend
.waitstatus
;
3524 tp
->suspend
.waitstatus_pending_p
= 0;
3526 /* Wake up the event loop again, until all pending events are
3528 if (target_is_async_p ())
3529 mark_async_event_handler (infrun_async_inferior_event_token
);
3533 /* But if we don't find one, we'll have to wait. */
3535 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3537 if (!target_can_async_p ())
3538 options
&= ~TARGET_WNOHANG
;
3540 if (deprecated_target_wait_hook
)
3541 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3543 event_ptid
= target_wait (ptid
, status
, options
);
3548 /* Wrapper for target_wait that first checks whether threads have
3549 pending statuses to report before actually asking the target for
3550 more events. Polls for events from all inferiors/targets. */
3553 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3554 target_wait_flags options
)
3556 int num_inferiors
= 0;
3557 int random_selector
;
3559 /* For fairness, we pick the first inferior/target to poll at random
3560 out of all inferiors that may report events, and then continue
3561 polling the rest of the inferior list starting from that one in a
3562 circular fashion until the whole list is polled once. */
3564 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3566 return (inf
->process_target () != NULL
3567 && ptid_t (inf
->pid
).matches (wait_ptid
));
3570 /* First see how many matching inferiors we have. */
3571 for (inferior
*inf
: all_inferiors ())
3572 if (inferior_matches (inf
))
3575 if (num_inferiors
== 0)
3577 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3581 /* Now randomly pick an inferior out of those that matched. */
3582 random_selector
= (int)
3583 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3585 if (num_inferiors
> 1)
3586 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3587 num_inferiors
, random_selector
);
3589 /* Select the Nth inferior that matched. */
3591 inferior
*selected
= nullptr;
3593 for (inferior
*inf
: all_inferiors ())
3594 if (inferior_matches (inf
))
3595 if (random_selector
-- == 0)
3601 /* Now poll for events out of each of the matching inferior's
3602 targets, starting from the selected one. */
3604 auto do_wait
= [&] (inferior
*inf
)
3606 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3607 ecs
->target
= inf
->process_target ();
3608 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3611 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3612 here spuriously after the target is all stopped and we've already
3613 reported the stop to the user, polling for events. */
3614 scoped_restore_current_thread restore_thread
;
3616 int inf_num
= selected
->num
;
3617 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3618 if (inferior_matches (inf
))
3622 for (inferior
*inf
= inferior_list
;
3623 inf
!= NULL
&& inf
->num
< inf_num
;
3625 if (inferior_matches (inf
))
3629 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3633 /* Prepare and stabilize the inferior for detaching it. E.g.,
3634 detaching while a thread is displaced stepping is a recipe for
3635 crashing it, as nothing would readjust the PC out of the scratch
3639 prepare_for_detach (void)
3641 struct inferior
*inf
= current_inferior ();
3642 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3644 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3646 /* Is any thread of this process displaced stepping? If not,
3647 there's nothing else to do. */
3648 if (displaced
->step_thread
== nullptr)
3651 infrun_debug_printf ("displaced-stepping in-process while detaching");
3653 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3655 while (displaced
->step_thread
!= nullptr)
3657 struct execution_control_state ecss
;
3658 struct execution_control_state
*ecs
;
3661 memset (ecs
, 0, sizeof (*ecs
));
3663 overlay_cache_invalid
= 1;
3664 /* Flush target cache before starting to handle each event.
3665 Target was running and cache could be stale. This is just a
3666 heuristic. Running threads may modify target memory, but we
3667 don't get any event. */
3668 target_dcache_invalidate ();
3670 do_target_wait (pid_ptid
, ecs
, 0);
3673 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3675 /* If an error happens while handling the event, propagate GDB's
3676 knowledge of the executing state to the frontend/user running
3678 scoped_finish_thread_state
finish_state (inf
->process_target (),
3681 /* Now figure out what to do with the result of the result. */
3682 handle_inferior_event (ecs
);
3684 /* No error, don't finish the state yet. */
3685 finish_state
.release ();
3687 /* Breakpoints and watchpoints are not installed on the target
3688 at this point, and signals are passed directly to the
3689 inferior, so this must mean the process is gone. */
3690 if (!ecs
->wait_some_more
)
3692 restore_detaching
.release ();
3693 error (_("Program exited while detaching"));
3697 restore_detaching
.release ();
3700 /* Wait for control to return from inferior to debugger.
3702 If inferior gets a signal, we may decide to start it up again
3703 instead of returning. That is why there is a loop in this function.
3704 When this function actually returns it means the inferior
3705 should be left stopped and GDB should read more commands. */
3708 wait_for_inferior (inferior
*inf
)
3710 infrun_debug_printf ("wait_for_inferior ()");
3712 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3714 /* If an error happens while handling the event, propagate GDB's
3715 knowledge of the executing state to the frontend/user running
3717 scoped_finish_thread_state finish_state
3718 (inf
->process_target (), minus_one_ptid
);
3722 struct execution_control_state ecss
;
3723 struct execution_control_state
*ecs
= &ecss
;
3725 memset (ecs
, 0, sizeof (*ecs
));
3727 overlay_cache_invalid
= 1;
3729 /* Flush target cache before starting to handle each event.
3730 Target was running and cache could be stale. This is just a
3731 heuristic. Running threads may modify target memory, but we
3732 don't get any event. */
3733 target_dcache_invalidate ();
3735 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3736 ecs
->target
= inf
->process_target ();
3739 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3741 /* Now figure out what to do with the result of the result. */
3742 handle_inferior_event (ecs
);
3744 if (!ecs
->wait_some_more
)
3748 /* No error, don't finish the state yet. */
3749 finish_state
.release ();
3752 /* Cleanup that reinstalls the readline callback handler, if the
3753 target is running in the background. If while handling the target
3754 event something triggered a secondary prompt, like e.g., a
3755 pagination prompt, we'll have removed the callback handler (see
3756 gdb_readline_wrapper_line). Need to do this as we go back to the
3757 event loop, ready to process further input. Note this has no
3758 effect if the handler hasn't actually been removed, because calling
3759 rl_callback_handler_install resets the line buffer, thus losing
3763 reinstall_readline_callback_handler_cleanup ()
3765 struct ui
*ui
= current_ui
;
3769 /* We're not going back to the top level event loop yet. Don't
3770 install the readline callback, as it'd prep the terminal,
3771 readline-style (raw, noecho) (e.g., --batch). We'll install
3772 it the next time the prompt is displayed, when we're ready
3777 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3778 gdb_rl_callback_handler_reinstall ();
3781 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3782 that's just the event thread. In all-stop, that's all threads. */
3785 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3787 if (ecs
->event_thread
!= NULL
3788 && ecs
->event_thread
->thread_fsm
!= NULL
)
3789 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3793 for (thread_info
*thr
: all_non_exited_threads ())
3795 if (thr
->thread_fsm
== NULL
)
3797 if (thr
== ecs
->event_thread
)
3800 switch_to_thread (thr
);
3801 thr
->thread_fsm
->clean_up (thr
);
3804 if (ecs
->event_thread
!= NULL
)
3805 switch_to_thread (ecs
->event_thread
);
3809 /* Helper for all_uis_check_sync_execution_done that works on the
3813 check_curr_ui_sync_execution_done (void)
3815 struct ui
*ui
= current_ui
;
3817 if (ui
->prompt_state
== PROMPT_NEEDED
3819 && !gdb_in_secondary_prompt_p (ui
))
3821 target_terminal::ours ();
3822 gdb::observers::sync_execution_done
.notify ();
3823 ui_register_input_event_handler (ui
);
3830 all_uis_check_sync_execution_done (void)
3832 SWITCH_THRU_ALL_UIS ()
3834 check_curr_ui_sync_execution_done ();
3841 all_uis_on_sync_execution_starting (void)
3843 SWITCH_THRU_ALL_UIS ()
3845 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3846 async_disable_stdin ();
3850 /* Asynchronous version of wait_for_inferior. It is called by the
3851 event loop whenever a change of state is detected on the file
3852 descriptor corresponding to the target. It can be called more than
3853 once to complete a single execution command. In such cases we need
3854 to keep the state in a global variable ECSS. If it is the last time
3855 that this function is called for a single execution command, then
3856 report to the user that the inferior has stopped, and do the
3857 necessary cleanups. */
3860 fetch_inferior_event ()
3862 struct execution_control_state ecss
;
3863 struct execution_control_state
*ecs
= &ecss
;
3866 memset (ecs
, 0, sizeof (*ecs
));
3868 /* Events are always processed with the main UI as current UI. This
3869 way, warnings, debug output, etc. are always consistently sent to
3870 the main console. */
3871 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3873 /* End up with readline processing input, if necessary. */
3875 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3877 /* We're handling a live event, so make sure we're doing live
3878 debugging. If we're looking at traceframes while the target is
3879 running, we're going to need to get back to that mode after
3880 handling the event. */
3881 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3884 maybe_restore_traceframe
.emplace ();
3885 set_current_traceframe (-1);
3888 /* The user/frontend should not notice a thread switch due to
3889 internal events. Make sure we revert to the user selected
3890 thread and frame after handling the event and running any
3891 breakpoint commands. */
3892 scoped_restore_current_thread restore_thread
;
3894 overlay_cache_invalid
= 1;
3895 /* Flush target cache before starting to handle each event. Target
3896 was running and cache could be stale. This is just a heuristic.
3897 Running threads may modify target memory, but we don't get any
3899 target_dcache_invalidate ();
3901 scoped_restore save_exec_dir
3902 = make_scoped_restore (&execution_direction
,
3903 target_execution_direction ());
3905 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3908 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3910 /* Switch to the target that generated the event, so we can do
3912 switch_to_target_no_thread (ecs
->target
);
3915 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3917 /* If an error happens while handling the event, propagate GDB's
3918 knowledge of the executing state to the frontend/user running
3920 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3921 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3923 /* Get executed before scoped_restore_current_thread above to apply
3924 still for the thread which has thrown the exception. */
3925 auto defer_bpstat_clear
3926 = make_scope_exit (bpstat_clear_actions
);
3927 auto defer_delete_threads
3928 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3930 /* Now figure out what to do with the result of the result. */
3931 handle_inferior_event (ecs
);
3933 if (!ecs
->wait_some_more
)
3935 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3936 int should_stop
= 1;
3937 struct thread_info
*thr
= ecs
->event_thread
;
3939 delete_just_stopped_threads_infrun_breakpoints ();
3943 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3945 if (thread_fsm
!= NULL
)
3946 should_stop
= thread_fsm
->should_stop (thr
);
3955 bool should_notify_stop
= true;
3958 clean_up_just_stopped_threads_fsms (ecs
);
3960 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3961 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3963 if (should_notify_stop
)
3965 /* We may not find an inferior if this was a process exit. */
3966 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3967 proceeded
= normal_stop ();
3972 inferior_event_handler (INF_EXEC_COMPLETE
);
3976 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3977 previously selected thread is gone. We have two
3978 choices - switch to no thread selected, or restore the
3979 previously selected thread (now exited). We chose the
3980 later, just because that's what GDB used to do. After
3981 this, "info threads" says "The current thread <Thread
3982 ID 2> has terminated." instead of "No thread
3986 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3987 restore_thread
.dont_restore ();
3991 defer_delete_threads
.release ();
3992 defer_bpstat_clear
.release ();
3994 /* No error, don't finish the thread states yet. */
3995 finish_state
.release ();
3997 /* This scope is used to ensure that readline callbacks are
3998 reinstalled here. */
4001 /* If a UI was in sync execution mode, and now isn't, restore its
4002 prompt (a synchronous execution command has finished, and we're
4003 ready for input). */
4004 all_uis_check_sync_execution_done ();
4007 && exec_done_display_p
4008 && (inferior_ptid
== null_ptid
4009 || inferior_thread ()->state
!= THREAD_RUNNING
))
4010 printf_unfiltered (_("completed.\n"));
4016 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4017 struct symtab_and_line sal
)
4019 /* This can be removed once this function no longer implicitly relies on the
4020 inferior_ptid value. */
4021 gdb_assert (inferior_ptid
== tp
->ptid
);
4023 tp
->control
.step_frame_id
= get_frame_id (frame
);
4024 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4026 tp
->current_symtab
= sal
.symtab
;
4027 tp
->current_line
= sal
.line
;
4030 /* Clear context switchable stepping state. */
4033 init_thread_stepping_state (struct thread_info
*tss
)
4035 tss
->stepped_breakpoint
= 0;
4036 tss
->stepping_over_breakpoint
= 0;
4037 tss
->stepping_over_watchpoint
= 0;
4038 tss
->step_after_step_resume_breakpoint
= 0;
4044 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4045 target_waitstatus status
)
4047 target_last_proc_target
= target
;
4048 target_last_wait_ptid
= ptid
;
4049 target_last_waitstatus
= status
;
4055 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4056 target_waitstatus
*status
)
4058 if (target
!= nullptr)
4059 *target
= target_last_proc_target
;
4060 if (ptid
!= nullptr)
4061 *ptid
= target_last_wait_ptid
;
4062 if (status
!= nullptr)
4063 *status
= target_last_waitstatus
;
4069 nullify_last_target_wait_ptid (void)
4071 target_last_proc_target
= nullptr;
4072 target_last_wait_ptid
= minus_one_ptid
;
4073 target_last_waitstatus
= {};
4076 /* Switch thread contexts. */
4079 context_switch (execution_control_state
*ecs
)
4081 if (ecs
->ptid
!= inferior_ptid
4082 && (inferior_ptid
== null_ptid
4083 || ecs
->event_thread
!= inferior_thread ()))
4085 infrun_debug_printf ("Switching context from %s to %s",
4086 target_pid_to_str (inferior_ptid
).c_str (),
4087 target_pid_to_str (ecs
->ptid
).c_str ());
4090 switch_to_thread (ecs
->event_thread
);
4093 /* If the target can't tell whether we've hit breakpoints
4094 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4095 check whether that could have been caused by a breakpoint. If so,
4096 adjust the PC, per gdbarch_decr_pc_after_break. */
4099 adjust_pc_after_break (struct thread_info
*thread
,
4100 struct target_waitstatus
*ws
)
4102 struct regcache
*regcache
;
4103 struct gdbarch
*gdbarch
;
4104 CORE_ADDR breakpoint_pc
, decr_pc
;
4106 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4107 we aren't, just return.
4109 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4110 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4111 implemented by software breakpoints should be handled through the normal
4114 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4115 different signals (SIGILL or SIGEMT for instance), but it is less
4116 clear where the PC is pointing afterwards. It may not match
4117 gdbarch_decr_pc_after_break. I don't know any specific target that
4118 generates these signals at breakpoints (the code has been in GDB since at
4119 least 1992) so I can not guess how to handle them here.
4121 In earlier versions of GDB, a target with
4122 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4123 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4124 target with both of these set in GDB history, and it seems unlikely to be
4125 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4127 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4130 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4133 /* In reverse execution, when a breakpoint is hit, the instruction
4134 under it has already been de-executed. The reported PC always
4135 points at the breakpoint address, so adjusting it further would
4136 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4139 B1 0x08000000 : INSN1
4140 B2 0x08000001 : INSN2
4142 PC -> 0x08000003 : INSN4
4144 Say you're stopped at 0x08000003 as above. Reverse continuing
4145 from that point should hit B2 as below. Reading the PC when the
4146 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4147 been de-executed already.
4149 B1 0x08000000 : INSN1
4150 B2 PC -> 0x08000001 : INSN2
4154 We can't apply the same logic as for forward execution, because
4155 we would wrongly adjust the PC to 0x08000000, since there's a
4156 breakpoint at PC - 1. We'd then report a hit on B1, although
4157 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4159 if (execution_direction
== EXEC_REVERSE
)
4162 /* If the target can tell whether the thread hit a SW breakpoint,
4163 trust it. Targets that can tell also adjust the PC
4165 if (target_supports_stopped_by_sw_breakpoint ())
4168 /* Note that relying on whether a breakpoint is planted in memory to
4169 determine this can fail. E.g,. the breakpoint could have been
4170 removed since. Or the thread could have been told to step an
4171 instruction the size of a breakpoint instruction, and only
4172 _after_ was a breakpoint inserted at its address. */
4174 /* If this target does not decrement the PC after breakpoints, then
4175 we have nothing to do. */
4176 regcache
= get_thread_regcache (thread
);
4177 gdbarch
= regcache
->arch ();
4179 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4183 const address_space
*aspace
= regcache
->aspace ();
4185 /* Find the location where (if we've hit a breakpoint) the
4186 breakpoint would be. */
4187 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4189 /* If the target can't tell whether a software breakpoint triggered,
4190 fallback to figuring it out based on breakpoints we think were
4191 inserted in the target, and on whether the thread was stepped or
4194 /* Check whether there actually is a software breakpoint inserted at
4197 If in non-stop mode, a race condition is possible where we've
4198 removed a breakpoint, but stop events for that breakpoint were
4199 already queued and arrive later. To suppress those spurious
4200 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4201 and retire them after a number of stop events are reported. Note
4202 this is an heuristic and can thus get confused. The real fix is
4203 to get the "stopped by SW BP and needs adjustment" info out of
4204 the target/kernel (and thus never reach here; see above). */
4205 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4206 || (target_is_non_stop_p ()
4207 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4209 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4211 if (record_full_is_used ())
4212 restore_operation_disable
.emplace
4213 (record_full_gdb_operation_disable_set ());
4215 /* When using hardware single-step, a SIGTRAP is reported for both
4216 a completed single-step and a software breakpoint. Need to
4217 differentiate between the two, as the latter needs adjusting
4218 but the former does not.
4220 The SIGTRAP can be due to a completed hardware single-step only if
4221 - we didn't insert software single-step breakpoints
4222 - this thread is currently being stepped
4224 If any of these events did not occur, we must have stopped due
4225 to hitting a software breakpoint, and have to back up to the
4228 As a special case, we could have hardware single-stepped a
4229 software breakpoint. In this case (prev_pc == breakpoint_pc),
4230 we also need to back up to the breakpoint address. */
4232 if (thread_has_single_step_breakpoints_set (thread
)
4233 || !currently_stepping (thread
)
4234 || (thread
->stepped_breakpoint
4235 && thread
->prev_pc
== breakpoint_pc
))
4236 regcache_write_pc (regcache
, breakpoint_pc
);
4241 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4243 for (frame
= get_prev_frame (frame
);
4245 frame
= get_prev_frame (frame
))
4247 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4250 if (get_frame_type (frame
) != INLINE_FRAME
)
4257 /* Look for an inline frame that is marked for skip.
4258 If PREV_FRAME is TRUE start at the previous frame,
4259 otherwise start at the current frame. Stop at the
4260 first non-inline frame, or at the frame where the
4264 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4266 struct frame_info
*frame
= get_current_frame ();
4269 frame
= get_prev_frame (frame
);
4271 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4273 const char *fn
= NULL
;
4274 symtab_and_line sal
;
4277 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4279 if (get_frame_type (frame
) != INLINE_FRAME
)
4282 sal
= find_frame_sal (frame
);
4283 sym
= get_frame_function (frame
);
4286 fn
= sym
->print_name ();
4289 && function_name_is_marked_for_skip (fn
, sal
))
4296 /* If the event thread has the stop requested flag set, pretend it
4297 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4301 handle_stop_requested (struct execution_control_state
*ecs
)
4303 if (ecs
->event_thread
->stop_requested
)
4305 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4306 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4307 handle_signal_stop (ecs
);
4313 /* Auxiliary function that handles syscall entry/return events.
4314 It returns true if the inferior should keep going (and GDB
4315 should ignore the event), or false if the event deserves to be
4319 handle_syscall_event (struct execution_control_state
*ecs
)
4321 struct regcache
*regcache
;
4324 context_switch (ecs
);
4326 regcache
= get_thread_regcache (ecs
->event_thread
);
4327 syscall_number
= ecs
->ws
.value
.syscall_number
;
4328 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4330 if (catch_syscall_enabled () > 0
4331 && catching_syscall_number (syscall_number
) > 0)
4333 infrun_debug_printf ("syscall number=%d", syscall_number
);
4335 ecs
->event_thread
->control
.stop_bpstat
4336 = bpstat_stop_status (regcache
->aspace (),
4337 ecs
->event_thread
->suspend
.stop_pc
,
4338 ecs
->event_thread
, &ecs
->ws
);
4340 if (handle_stop_requested (ecs
))
4343 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4345 /* Catchpoint hit. */
4350 if (handle_stop_requested (ecs
))
4353 /* If no catchpoint triggered for this, then keep going. */
4359 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4362 fill_in_stop_func (struct gdbarch
*gdbarch
,
4363 struct execution_control_state
*ecs
)
4365 if (!ecs
->stop_func_filled_in
)
4368 const general_symbol_info
*gsi
;
4370 /* Don't care about return value; stop_func_start and stop_func_name
4371 will both be 0 if it doesn't work. */
4372 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4374 &ecs
->stop_func_start
,
4375 &ecs
->stop_func_end
,
4377 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4379 /* The call to find_pc_partial_function, above, will set
4380 stop_func_start and stop_func_end to the start and end
4381 of the range containing the stop pc. If this range
4382 contains the entry pc for the block (which is always the
4383 case for contiguous blocks), advance stop_func_start past
4384 the function's start offset and entrypoint. Note that
4385 stop_func_start is NOT advanced when in a range of a
4386 non-contiguous block that does not contain the entry pc. */
4387 if (block
!= nullptr
4388 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4389 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4391 ecs
->stop_func_start
4392 += gdbarch_deprecated_function_start_offset (gdbarch
);
4394 if (gdbarch_skip_entrypoint_p (gdbarch
))
4395 ecs
->stop_func_start
4396 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4399 ecs
->stop_func_filled_in
= 1;
4404 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4406 static enum stop_kind
4407 get_inferior_stop_soon (execution_control_state
*ecs
)
4409 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4411 gdb_assert (inf
!= NULL
);
4412 return inf
->control
.stop_soon
;
4415 /* Poll for one event out of the current target. Store the resulting
4416 waitstatus in WS, and return the event ptid. Does not block. */
4419 poll_one_curr_target (struct target_waitstatus
*ws
)
4423 overlay_cache_invalid
= 1;
4425 /* Flush target cache before starting to handle each event.
4426 Target was running and cache could be stale. This is just a
4427 heuristic. Running threads may modify target memory, but we
4428 don't get any event. */
4429 target_dcache_invalidate ();
4431 if (deprecated_target_wait_hook
)
4432 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4434 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4437 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4442 /* An event reported by wait_one. */
4444 struct wait_one_event
4446 /* The target the event came out of. */
4447 process_stratum_target
*target
;
4449 /* The PTID the event was for. */
4452 /* The waitstatus. */
4453 target_waitstatus ws
;
4456 /* Wait for one event out of any target. */
4458 static wait_one_event
4463 for (inferior
*inf
: all_inferiors ())
4465 process_stratum_target
*target
= inf
->process_target ();
4467 || !target
->is_async_p ()
4468 || !target
->threads_executing
)
4471 switch_to_inferior_no_thread (inf
);
4473 wait_one_event event
;
4474 event
.target
= target
;
4475 event
.ptid
= poll_one_curr_target (&event
.ws
);
4477 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4479 /* If nothing is resumed, remove the target from the
4483 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4487 /* Block waiting for some event. */
4494 for (inferior
*inf
: all_inferiors ())
4496 process_stratum_target
*target
= inf
->process_target ();
4498 || !target
->is_async_p ()
4499 || !target
->threads_executing
)
4502 int fd
= target
->async_wait_fd ();
4503 FD_SET (fd
, &readfds
);
4510 /* No waitable targets left. All must be stopped. */
4511 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4516 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4522 perror_with_name ("interruptible_select");
4527 /* Save the thread's event and stop reason to process it later. */
4530 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4532 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4533 target_waitstatus_to_string (ws
).c_str (),
4538 /* Record for later. */
4539 tp
->suspend
.waitstatus
= *ws
;
4540 tp
->suspend
.waitstatus_pending_p
= 1;
4542 struct regcache
*regcache
= get_thread_regcache (tp
);
4543 const address_space
*aspace
= regcache
->aspace ();
4545 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4546 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4548 CORE_ADDR pc
= regcache_read_pc (regcache
);
4550 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4552 scoped_restore_current_thread restore_thread
;
4553 switch_to_thread (tp
);
4555 if (target_stopped_by_watchpoint ())
4557 tp
->suspend
.stop_reason
4558 = TARGET_STOPPED_BY_WATCHPOINT
;
4560 else if (target_supports_stopped_by_sw_breakpoint ()
4561 && target_stopped_by_sw_breakpoint ())
4563 tp
->suspend
.stop_reason
4564 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4566 else if (target_supports_stopped_by_hw_breakpoint ()
4567 && target_stopped_by_hw_breakpoint ())
4569 tp
->suspend
.stop_reason
4570 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4572 else if (!target_supports_stopped_by_hw_breakpoint ()
4573 && hardware_breakpoint_inserted_here_p (aspace
,
4576 tp
->suspend
.stop_reason
4577 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4579 else if (!target_supports_stopped_by_sw_breakpoint ()
4580 && software_breakpoint_inserted_here_p (aspace
,
4583 tp
->suspend
.stop_reason
4584 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4586 else if (!thread_has_single_step_breakpoints_set (tp
)
4587 && currently_stepping (tp
))
4589 tp
->suspend
.stop_reason
4590 = TARGET_STOPPED_BY_SINGLE_STEP
;
4595 /* Mark the non-executing threads accordingly. In all-stop, all
4596 threads of all processes are stopped when we get any event
4597 reported. In non-stop mode, only the event thread stops. */
4600 mark_non_executing_threads (process_stratum_target
*target
,
4602 struct target_waitstatus ws
)
4606 if (!target_is_non_stop_p ())
4607 mark_ptid
= minus_one_ptid
;
4608 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4609 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4611 /* If we're handling a process exit in non-stop mode, even
4612 though threads haven't been deleted yet, one would think
4613 that there is nothing to do, as threads of the dead process
4614 will be soon deleted, and threads of any other process were
4615 left running. However, on some targets, threads survive a
4616 process exit event. E.g., for the "checkpoint" command,
4617 when the current checkpoint/fork exits, linux-fork.c
4618 automatically switches to another fork from within
4619 target_mourn_inferior, by associating the same
4620 inferior/thread to another fork. We haven't mourned yet at
4621 this point, but we must mark any threads left in the
4622 process as not-executing so that finish_thread_state marks
4623 them stopped (in the user's perspective) if/when we present
4624 the stop to the user. */
4625 mark_ptid
= ptid_t (event_ptid
.pid ());
4628 mark_ptid
= event_ptid
;
4630 set_executing (target
, mark_ptid
, false);
4632 /* Likewise the resumed flag. */
4633 set_resumed (target
, mark_ptid
, false);
4639 stop_all_threads (void)
4641 /* We may need multiple passes to discover all threads. */
4645 gdb_assert (exists_non_stop_target ());
4647 infrun_debug_printf ("starting");
4649 scoped_restore_current_thread restore_thread
;
4651 /* Enable thread events of all targets. */
4652 for (auto *target
: all_non_exited_process_targets ())
4654 switch_to_target_no_thread (target
);
4655 target_thread_events (true);
4660 /* Disable thread events of all targets. */
4661 for (auto *target
: all_non_exited_process_targets ())
4663 switch_to_target_no_thread (target
);
4664 target_thread_events (false);
4667 /* Use infrun_debug_printf_1 directly to get a meaningful function
4670 infrun_debug_printf_1 ("stop_all_threads", "done");
4673 /* Request threads to stop, and then wait for the stops. Because
4674 threads we already know about can spawn more threads while we're
4675 trying to stop them, and we only learn about new threads when we
4676 update the thread list, do this in a loop, and keep iterating
4677 until two passes find no threads that need to be stopped. */
4678 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4680 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4683 int waits_needed
= 0;
4685 for (auto *target
: all_non_exited_process_targets ())
4687 switch_to_target_no_thread (target
);
4688 update_thread_list ();
4691 /* Go through all threads looking for threads that we need
4692 to tell the target to stop. */
4693 for (thread_info
*t
: all_non_exited_threads ())
4695 /* For a single-target setting with an all-stop target,
4696 we would not even arrive here. For a multi-target
4697 setting, until GDB is able to handle a mixture of
4698 all-stop and non-stop targets, simply skip all-stop
4699 targets' threads. This should be fine due to the
4700 protection of 'check_multi_target_resumption'. */
4702 switch_to_thread_no_regs (t
);
4703 if (!target_is_non_stop_p ())
4708 /* If already stopping, don't request a stop again.
4709 We just haven't seen the notification yet. */
4710 if (!t
->stop_requested
)
4712 infrun_debug_printf (" %s executing, need stop",
4713 target_pid_to_str (t
->ptid
).c_str ());
4714 target_stop (t
->ptid
);
4715 t
->stop_requested
= 1;
4719 infrun_debug_printf (" %s executing, already stopping",
4720 target_pid_to_str (t
->ptid
).c_str ());
4723 if (t
->stop_requested
)
4728 infrun_debug_printf (" %s not executing",
4729 target_pid_to_str (t
->ptid
).c_str ());
4731 /* The thread may be not executing, but still be
4732 resumed with a pending status to process. */
4737 if (waits_needed
== 0)
4740 /* If we find new threads on the second iteration, restart
4741 over. We want to see two iterations in a row with all
4746 for (int i
= 0; i
< waits_needed
; i
++)
4748 wait_one_event event
= wait_one ();
4751 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4752 target_pid_to_str (event
.ptid
).c_str ());
4754 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4756 /* All resumed threads exited. */
4759 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4760 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4761 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4763 /* One thread/process exited/signalled. */
4765 thread_info
*t
= nullptr;
4767 /* The target may have reported just a pid. If so, try
4768 the first non-exited thread. */
4769 if (event
.ptid
.is_pid ())
4771 int pid
= event
.ptid
.pid ();
4772 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4773 for (thread_info
*tp
: inf
->non_exited_threads ())
4779 /* If there is no available thread, the event would
4780 have to be appended to a per-inferior event list,
4781 which does not exist (and if it did, we'd have
4782 to adjust run control command to be able to
4783 resume such an inferior). We assert here instead
4784 of going into an infinite loop. */
4785 gdb_assert (t
!= nullptr);
4788 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4792 t
= find_thread_ptid (event
.target
, event
.ptid
);
4793 /* Check if this is the first time we see this thread.
4794 Don't bother adding if it individually exited. */
4796 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4797 t
= add_thread (event
.target
, event
.ptid
);
4802 /* Set the threads as non-executing to avoid
4803 another stop attempt on them. */
4804 switch_to_thread_no_regs (t
);
4805 mark_non_executing_threads (event
.target
, event
.ptid
,
4807 save_waitstatus (t
, &event
.ws
);
4808 t
->stop_requested
= false;
4813 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4815 t
= add_thread (event
.target
, event
.ptid
);
4817 t
->stop_requested
= 0;
4820 t
->control
.may_range_step
= 0;
4822 /* This may be the first time we see the inferior report
4824 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4825 if (inf
->needs_setup
)
4827 switch_to_thread_no_regs (t
);
4831 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4832 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4834 /* We caught the event that we intended to catch, so
4835 there's no event pending. */
4836 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4837 t
->suspend
.waitstatus_pending_p
= 0;
4839 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4841 /* Add it back to the step-over queue. */
4843 ("displaced-step of %s canceled: adding back to "
4844 "the step-over queue",
4845 target_pid_to_str (t
->ptid
).c_str ());
4847 t
->control
.trap_expected
= 0;
4848 thread_step_over_chain_enqueue (t
);
4853 enum gdb_signal sig
;
4854 struct regcache
*regcache
;
4857 ("target_wait %s, saving status for %d.%ld.%ld",
4858 target_waitstatus_to_string (&event
.ws
).c_str (),
4859 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4861 /* Record for later. */
4862 save_waitstatus (t
, &event
.ws
);
4864 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4865 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4867 if (displaced_step_fixup (t
, sig
) < 0)
4869 /* Add it back to the step-over queue. */
4870 t
->control
.trap_expected
= 0;
4871 thread_step_over_chain_enqueue (t
);
4874 regcache
= get_thread_regcache (t
);
4875 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4877 infrun_debug_printf ("saved stop_pc=%s for %s "
4878 "(currently_stepping=%d)",
4879 paddress (target_gdbarch (),
4880 t
->suspend
.stop_pc
),
4881 target_pid_to_str (t
->ptid
).c_str (),
4882 currently_stepping (t
));
4890 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4893 handle_no_resumed (struct execution_control_state
*ecs
)
4895 if (target_can_async_p ())
4897 bool any_sync
= false;
4899 for (ui
*ui
: all_uis ())
4901 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4909 /* There were no unwaited-for children left in the target, but,
4910 we're not synchronously waiting for events either. Just
4913 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4914 prepare_to_wait (ecs
);
4919 /* Otherwise, if we were running a synchronous execution command, we
4920 may need to cancel it and give the user back the terminal.
4922 In non-stop mode, the target can't tell whether we've already
4923 consumed previous stop events, so it can end up sending us a
4924 no-resumed event like so:
4926 #0 - thread 1 is left stopped
4928 #1 - thread 2 is resumed and hits breakpoint
4929 -> TARGET_WAITKIND_STOPPED
4931 #2 - thread 3 is resumed and exits
4932 this is the last resumed thread, so
4933 -> TARGET_WAITKIND_NO_RESUMED
4935 #3 - gdb processes stop for thread 2 and decides to re-resume
4938 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4939 thread 2 is now resumed, so the event should be ignored.
4941 IOW, if the stop for thread 2 doesn't end a foreground command,
4942 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4943 event. But it could be that the event meant that thread 2 itself
4944 (or whatever other thread was the last resumed thread) exited.
4946 To address this we refresh the thread list and check whether we
4947 have resumed threads _now_. In the example above, this removes
4948 thread 3 from the thread list. If thread 2 was re-resumed, we
4949 ignore this event. If we find no thread resumed, then we cancel
4950 the synchronous command and show "no unwaited-for " to the
4953 inferior
*curr_inf
= current_inferior ();
4955 scoped_restore_current_thread restore_thread
;
4957 for (auto *target
: all_non_exited_process_targets ())
4959 switch_to_target_no_thread (target
);
4960 update_thread_list ();
4965 - the current target has no thread executing, and
4966 - the current inferior is native, and
4967 - the current inferior is the one which has the terminal, and
4970 then a Ctrl-C from this point on would remain stuck in the
4971 kernel, until a thread resumes and dequeues it. That would
4972 result in the GDB CLI not reacting to Ctrl-C, not able to
4973 interrupt the program. To address this, if the current inferior
4974 no longer has any thread executing, we give the terminal to some
4975 other inferior that has at least one thread executing. */
4976 bool swap_terminal
= true;
4978 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4979 whether to report it to the user. */
4980 bool ignore_event
= false;
4982 for (thread_info
*thread
: all_non_exited_threads ())
4984 if (swap_terminal
&& thread
->executing
)
4986 if (thread
->inf
!= curr_inf
)
4988 target_terminal::ours ();
4990 switch_to_thread (thread
);
4991 target_terminal::inferior ();
4993 swap_terminal
= false;
4997 && (thread
->executing
4998 || thread
->suspend
.waitstatus_pending_p
))
5000 /* Either there were no unwaited-for children left in the
5001 target at some point, but there are now, or some target
5002 other than the eventing one has unwaited-for children
5003 left. Just ignore. */
5004 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
5005 "(ignoring: found resumed)");
5007 ignore_event
= true;
5010 if (ignore_event
&& !swap_terminal
)
5016 switch_to_inferior_no_thread (curr_inf
);
5017 prepare_to_wait (ecs
);
5021 /* Go ahead and report the event. */
5025 /* Given an execution control state that has been freshly filled in by
5026 an event from the inferior, figure out what it means and take
5029 The alternatives are:
5031 1) stop_waiting and return; to really stop and return to the
5034 2) keep_going and return; to wait for the next event (set
5035 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5039 handle_inferior_event (struct execution_control_state
*ecs
)
5041 /* Make sure that all temporary struct value objects that were
5042 created during the handling of the event get deleted at the
5044 scoped_value_mark free_values
;
5046 enum stop_kind stop_soon
;
5048 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5050 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5052 /* We had an event in the inferior, but we are not interested in
5053 handling it at this level. The lower layers have already
5054 done what needs to be done, if anything.
5056 One of the possible circumstances for this is when the
5057 inferior produces output for the console. The inferior has
5058 not stopped, and we are ignoring the event. Another possible
5059 circumstance is any event which the lower level knows will be
5060 reported multiple times without an intervening resume. */
5061 prepare_to_wait (ecs
);
5065 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5067 prepare_to_wait (ecs
);
5071 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5072 && handle_no_resumed (ecs
))
5075 /* Cache the last target/ptid/waitstatus. */
5076 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5078 /* Always clear state belonging to the previous time we stopped. */
5079 stop_stack_dummy
= STOP_NONE
;
5081 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5083 /* No unwaited-for children left. IOW, all resumed children
5085 stop_print_frame
= false;
5090 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5091 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5093 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5094 /* If it's a new thread, add it to the thread database. */
5095 if (ecs
->event_thread
== NULL
)
5096 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5098 /* Disable range stepping. If the next step request could use a
5099 range, this will be end up re-enabled then. */
5100 ecs
->event_thread
->control
.may_range_step
= 0;
5103 /* Dependent on valid ECS->EVENT_THREAD. */
5104 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5106 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5107 reinit_frame_cache ();
5109 breakpoint_retire_moribund ();
5111 /* First, distinguish signals caused by the debugger from signals
5112 that have to do with the program's own actions. Note that
5113 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5114 on the operating system version. Here we detect when a SIGILL or
5115 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5116 something similar for SIGSEGV, since a SIGSEGV will be generated
5117 when we're trying to execute a breakpoint instruction on a
5118 non-executable stack. This happens for call dummy breakpoints
5119 for architectures like SPARC that place call dummies on the
5121 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5122 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5123 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5124 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5126 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5128 if (breakpoint_inserted_here_p (regcache
->aspace (),
5129 regcache_read_pc (regcache
)))
5131 infrun_debug_printf ("Treating signal as SIGTRAP");
5132 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5136 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5138 switch (ecs
->ws
.kind
)
5140 case TARGET_WAITKIND_LOADED
:
5141 context_switch (ecs
);
5142 /* Ignore gracefully during startup of the inferior, as it might
5143 be the shell which has just loaded some objects, otherwise
5144 add the symbols for the newly loaded objects. Also ignore at
5145 the beginning of an attach or remote session; we will query
5146 the full list of libraries once the connection is
5149 stop_soon
= get_inferior_stop_soon (ecs
);
5150 if (stop_soon
== NO_STOP_QUIETLY
)
5152 struct regcache
*regcache
;
5154 regcache
= get_thread_regcache (ecs
->event_thread
);
5156 handle_solib_event ();
5158 ecs
->event_thread
->control
.stop_bpstat
5159 = bpstat_stop_status (regcache
->aspace (),
5160 ecs
->event_thread
->suspend
.stop_pc
,
5161 ecs
->event_thread
, &ecs
->ws
);
5163 if (handle_stop_requested (ecs
))
5166 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5168 /* A catchpoint triggered. */
5169 process_event_stop_test (ecs
);
5173 /* If requested, stop when the dynamic linker notifies
5174 gdb of events. This allows the user to get control
5175 and place breakpoints in initializer routines for
5176 dynamically loaded objects (among other things). */
5177 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5178 if (stop_on_solib_events
)
5180 /* Make sure we print "Stopped due to solib-event" in
5182 stop_print_frame
= true;
5189 /* If we are skipping through a shell, or through shared library
5190 loading that we aren't interested in, resume the program. If
5191 we're running the program normally, also resume. */
5192 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5194 /* Loading of shared libraries might have changed breakpoint
5195 addresses. Make sure new breakpoints are inserted. */
5196 if (stop_soon
== NO_STOP_QUIETLY
)
5197 insert_breakpoints ();
5198 resume (GDB_SIGNAL_0
);
5199 prepare_to_wait (ecs
);
5203 /* But stop if we're attaching or setting up a remote
5205 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5206 || stop_soon
== STOP_QUIETLY_REMOTE
)
5208 infrun_debug_printf ("quietly stopped");
5213 internal_error (__FILE__
, __LINE__
,
5214 _("unhandled stop_soon: %d"), (int) stop_soon
);
5216 case TARGET_WAITKIND_SPURIOUS
:
5217 if (handle_stop_requested (ecs
))
5219 context_switch (ecs
);
5220 resume (GDB_SIGNAL_0
);
5221 prepare_to_wait (ecs
);
5224 case TARGET_WAITKIND_THREAD_CREATED
:
5225 if (handle_stop_requested (ecs
))
5227 context_switch (ecs
);
5228 if (!switch_back_to_stepped_thread (ecs
))
5232 case TARGET_WAITKIND_EXITED
:
5233 case TARGET_WAITKIND_SIGNALLED
:
5235 /* Depending on the system, ecs->ptid may point to a thread or
5236 to a process. On some targets, target_mourn_inferior may
5237 need to have access to the just-exited thread. That is the
5238 case of GNU/Linux's "checkpoint" support, for example.
5239 Call the switch_to_xxx routine as appropriate. */
5240 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5242 switch_to_thread (thr
);
5245 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5246 switch_to_inferior_no_thread (inf
);
5249 handle_vfork_child_exec_or_exit (0);
5250 target_terminal::ours (); /* Must do this before mourn anyway. */
5252 /* Clearing any previous state of convenience variables. */
5253 clear_exit_convenience_vars ();
5255 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5257 /* Record the exit code in the convenience variable $_exitcode, so
5258 that the user can inspect this again later. */
5259 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5260 (LONGEST
) ecs
->ws
.value
.integer
);
5262 /* Also record this in the inferior itself. */
5263 current_inferior ()->has_exit_code
= 1;
5264 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5266 /* Support the --return-child-result option. */
5267 return_child_result_value
= ecs
->ws
.value
.integer
;
5269 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5273 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5275 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5277 /* Set the value of the internal variable $_exitsignal,
5278 which holds the signal uncaught by the inferior. */
5279 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5280 gdbarch_gdb_signal_to_target (gdbarch
,
5281 ecs
->ws
.value
.sig
));
5285 /* We don't have access to the target's method used for
5286 converting between signal numbers (GDB's internal
5287 representation <-> target's representation).
5288 Therefore, we cannot do a good job at displaying this
5289 information to the user. It's better to just warn
5290 her about it (if infrun debugging is enabled), and
5292 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5296 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5299 gdb_flush (gdb_stdout
);
5300 target_mourn_inferior (inferior_ptid
);
5301 stop_print_frame
= false;
5305 case TARGET_WAITKIND_FORKED
:
5306 case TARGET_WAITKIND_VFORKED
:
5307 /* Check whether the inferior is displaced stepping. */
5309 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5310 struct gdbarch
*gdbarch
= regcache
->arch ();
5312 /* If checking displaced stepping is supported, and thread
5313 ecs->ptid is displaced stepping. */
5314 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5316 struct inferior
*parent_inf
5317 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5318 struct regcache
*child_regcache
;
5319 CORE_ADDR parent_pc
;
5321 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5323 struct displaced_step_inferior_state
*displaced
5324 = get_displaced_stepping_state (parent_inf
);
5326 /* Restore scratch pad for child process. */
5327 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5330 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5331 indicating that the displaced stepping of syscall instruction
5332 has been done. Perform cleanup for parent process here. Note
5333 that this operation also cleans up the child process for vfork,
5334 because their pages are shared. */
5335 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5336 /* Start a new step-over in another thread if there's one
5340 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5341 the child's PC is also within the scratchpad. Set the child's PC
5342 to the parent's PC value, which has already been fixed up.
5343 FIXME: we use the parent's aspace here, although we're touching
5344 the child, because the child hasn't been added to the inferior
5345 list yet at this point. */
5348 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5349 ecs
->ws
.value
.related_pid
,
5351 parent_inf
->aspace
);
5352 /* Read PC value of parent process. */
5353 parent_pc
= regcache_read_pc (regcache
);
5355 if (debug_displaced
)
5356 fprintf_unfiltered (gdb_stdlog
,
5357 "displaced: write child pc from %s to %s\n",
5359 regcache_read_pc (child_regcache
)),
5360 paddress (gdbarch
, parent_pc
));
5362 regcache_write_pc (child_regcache
, parent_pc
);
5366 context_switch (ecs
);
5368 /* Immediately detach breakpoints from the child before there's
5369 any chance of letting the user delete breakpoints from the
5370 breakpoint lists. If we don't do this early, it's easy to
5371 leave left over traps in the child, vis: "break foo; catch
5372 fork; c; <fork>; del; c; <child calls foo>". We only follow
5373 the fork on the last `continue', and by that time the
5374 breakpoint at "foo" is long gone from the breakpoint table.
5375 If we vforked, then we don't need to unpatch here, since both
5376 parent and child are sharing the same memory pages; we'll
5377 need to unpatch at follow/detach time instead to be certain
5378 that new breakpoints added between catchpoint hit time and
5379 vfork follow are detached. */
5380 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5382 /* This won't actually modify the breakpoint list, but will
5383 physically remove the breakpoints from the child. */
5384 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5387 delete_just_stopped_threads_single_step_breakpoints ();
5389 /* In case the event is caught by a catchpoint, remember that
5390 the event is to be followed at the next resume of the thread,
5391 and not immediately. */
5392 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5394 ecs
->event_thread
->suspend
.stop_pc
5395 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5397 ecs
->event_thread
->control
.stop_bpstat
5398 = bpstat_stop_status (get_current_regcache ()->aspace (),
5399 ecs
->event_thread
->suspend
.stop_pc
,
5400 ecs
->event_thread
, &ecs
->ws
);
5402 if (handle_stop_requested (ecs
))
5405 /* If no catchpoint triggered for this, then keep going. Note
5406 that we're interested in knowing the bpstat actually causes a
5407 stop, not just if it may explain the signal. Software
5408 watchpoints, for example, always appear in the bpstat. */
5409 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5412 = (follow_fork_mode_string
== follow_fork_mode_child
);
5414 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5416 process_stratum_target
*targ
5417 = ecs
->event_thread
->inf
->process_target ();
5419 bool should_resume
= follow_fork ();
5421 /* Note that one of these may be an invalid pointer,
5422 depending on detach_fork. */
5423 thread_info
*parent
= ecs
->event_thread
;
5425 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5427 /* At this point, the parent is marked running, and the
5428 child is marked stopped. */
5430 /* If not resuming the parent, mark it stopped. */
5431 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5432 parent
->set_running (false);
5434 /* If resuming the child, mark it running. */
5435 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5436 child
->set_running (true);
5438 /* In non-stop mode, also resume the other branch. */
5439 if (!detach_fork
&& (non_stop
5440 || (sched_multi
&& target_is_non_stop_p ())))
5443 switch_to_thread (parent
);
5445 switch_to_thread (child
);
5447 ecs
->event_thread
= inferior_thread ();
5448 ecs
->ptid
= inferior_ptid
;
5453 switch_to_thread (child
);
5455 switch_to_thread (parent
);
5457 ecs
->event_thread
= inferior_thread ();
5458 ecs
->ptid
= inferior_ptid
;
5466 process_event_stop_test (ecs
);
5469 case TARGET_WAITKIND_VFORK_DONE
:
5470 /* Done with the shared memory region. Re-insert breakpoints in
5471 the parent, and keep going. */
5473 context_switch (ecs
);
5475 current_inferior ()->waiting_for_vfork_done
= 0;
5476 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5478 if (handle_stop_requested (ecs
))
5481 /* This also takes care of reinserting breakpoints in the
5482 previously locked inferior. */
5486 case TARGET_WAITKIND_EXECD
:
5488 /* Note we can't read registers yet (the stop_pc), because we
5489 don't yet know the inferior's post-exec architecture.
5490 'stop_pc' is explicitly read below instead. */
5491 switch_to_thread_no_regs (ecs
->event_thread
);
5493 /* Do whatever is necessary to the parent branch of the vfork. */
5494 handle_vfork_child_exec_or_exit (1);
5496 /* This causes the eventpoints and symbol table to be reset.
5497 Must do this now, before trying to determine whether to
5499 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5501 /* In follow_exec we may have deleted the original thread and
5502 created a new one. Make sure that the event thread is the
5503 execd thread for that case (this is a nop otherwise). */
5504 ecs
->event_thread
= inferior_thread ();
5506 ecs
->event_thread
->suspend
.stop_pc
5507 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5509 ecs
->event_thread
->control
.stop_bpstat
5510 = bpstat_stop_status (get_current_regcache ()->aspace (),
5511 ecs
->event_thread
->suspend
.stop_pc
,
5512 ecs
->event_thread
, &ecs
->ws
);
5514 /* Note that this may be referenced from inside
5515 bpstat_stop_status above, through inferior_has_execd. */
5516 xfree (ecs
->ws
.value
.execd_pathname
);
5517 ecs
->ws
.value
.execd_pathname
= NULL
;
5519 if (handle_stop_requested (ecs
))
5522 /* If no catchpoint triggered for this, then keep going. */
5523 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5525 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5529 process_event_stop_test (ecs
);
5532 /* Be careful not to try to gather much state about a thread
5533 that's in a syscall. It's frequently a losing proposition. */
5534 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5535 /* Getting the current syscall number. */
5536 if (handle_syscall_event (ecs
) == 0)
5537 process_event_stop_test (ecs
);
5540 /* Before examining the threads further, step this thread to
5541 get it entirely out of the syscall. (We get notice of the
5542 event when the thread is just on the verge of exiting a
5543 syscall. Stepping one instruction seems to get it back
5545 case TARGET_WAITKIND_SYSCALL_RETURN
:
5546 if (handle_syscall_event (ecs
) == 0)
5547 process_event_stop_test (ecs
);
5550 case TARGET_WAITKIND_STOPPED
:
5551 handle_signal_stop (ecs
);
5554 case TARGET_WAITKIND_NO_HISTORY
:
5555 /* Reverse execution: target ran out of history info. */
5557 /* Switch to the stopped thread. */
5558 context_switch (ecs
);
5559 infrun_debug_printf ("stopped");
5561 delete_just_stopped_threads_single_step_breakpoints ();
5562 ecs
->event_thread
->suspend
.stop_pc
5563 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5565 if (handle_stop_requested (ecs
))
5568 gdb::observers::no_history
.notify ();
5574 /* Restart threads back to what they were trying to do back when we
5575 paused them for an in-line step-over. The EVENT_THREAD thread is
5579 restart_threads (struct thread_info
*event_thread
)
5581 /* In case the instruction just stepped spawned a new thread. */
5582 update_thread_list ();
5584 for (thread_info
*tp
: all_non_exited_threads ())
5586 switch_to_thread_no_regs (tp
);
5588 if (tp
== event_thread
)
5590 infrun_debug_printf ("restart threads: [%s] is event thread",
5591 target_pid_to_str (tp
->ptid
).c_str ());
5595 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5597 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5598 target_pid_to_str (tp
->ptid
).c_str ());
5604 infrun_debug_printf ("restart threads: [%s] resumed",
5605 target_pid_to_str (tp
->ptid
).c_str ());
5606 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5610 if (thread_is_in_step_over_chain (tp
))
5612 infrun_debug_printf ("restart threads: [%s] needs step-over",
5613 target_pid_to_str (tp
->ptid
).c_str ());
5614 gdb_assert (!tp
->resumed
);
5619 if (tp
->suspend
.waitstatus_pending_p
)
5621 infrun_debug_printf ("restart threads: [%s] has pending status",
5622 target_pid_to_str (tp
->ptid
).c_str ());
5627 gdb_assert (!tp
->stop_requested
);
5629 /* If some thread needs to start a step-over at this point, it
5630 should still be in the step-over queue, and thus skipped
5632 if (thread_still_needs_step_over (tp
))
5634 internal_error (__FILE__
, __LINE__
,
5635 "thread [%s] needs a step-over, but not in "
5636 "step-over queue\n",
5637 target_pid_to_str (tp
->ptid
).c_str ());
5640 if (currently_stepping (tp
))
5642 infrun_debug_printf ("restart threads: [%s] was stepping",
5643 target_pid_to_str (tp
->ptid
).c_str ());
5644 keep_going_stepped_thread (tp
);
5648 struct execution_control_state ecss
;
5649 struct execution_control_state
*ecs
= &ecss
;
5651 infrun_debug_printf ("restart threads: [%s] continuing",
5652 target_pid_to_str (tp
->ptid
).c_str ());
5653 reset_ecs (ecs
, tp
);
5654 switch_to_thread (tp
);
5655 keep_going_pass_signal (ecs
);
5660 /* Callback for iterate_over_threads. Find a resumed thread that has
5661 a pending waitstatus. */
5664 resumed_thread_with_pending_status (struct thread_info
*tp
,
5668 && tp
->suspend
.waitstatus_pending_p
);
5671 /* Called when we get an event that may finish an in-line or
5672 out-of-line (displaced stepping) step-over started previously.
5673 Return true if the event is processed and we should go back to the
5674 event loop; false if the caller should continue processing the
5678 finish_step_over (struct execution_control_state
*ecs
)
5680 displaced_step_fixup (ecs
->event_thread
,
5681 ecs
->event_thread
->suspend
.stop_signal
);
5683 bool had_step_over_info
= step_over_info_valid_p ();
5685 if (had_step_over_info
)
5687 /* If we're stepping over a breakpoint with all threads locked,
5688 then only the thread that was stepped should be reporting
5690 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5692 clear_step_over_info ();
5695 if (!target_is_non_stop_p ())
5698 /* Start a new step-over in another thread if there's one that
5702 /* If we were stepping over a breakpoint before, and haven't started
5703 a new in-line step-over sequence, then restart all other threads
5704 (except the event thread). We can't do this in all-stop, as then
5705 e.g., we wouldn't be able to issue any other remote packet until
5706 these other threads stop. */
5707 if (had_step_over_info
&& !step_over_info_valid_p ())
5709 struct thread_info
*pending
;
5711 /* If we only have threads with pending statuses, the restart
5712 below won't restart any thread and so nothing re-inserts the
5713 breakpoint we just stepped over. But we need it inserted
5714 when we later process the pending events, otherwise if
5715 another thread has a pending event for this breakpoint too,
5716 we'd discard its event (because the breakpoint that
5717 originally caused the event was no longer inserted). */
5718 context_switch (ecs
);
5719 insert_breakpoints ();
5721 restart_threads (ecs
->event_thread
);
5723 /* If we have events pending, go through handle_inferior_event
5724 again, picking up a pending event at random. This avoids
5725 thread starvation. */
5727 /* But not if we just stepped over a watchpoint in order to let
5728 the instruction execute so we can evaluate its expression.
5729 The set of watchpoints that triggered is recorded in the
5730 breakpoint objects themselves (see bp->watchpoint_triggered).
5731 If we processed another event first, that other event could
5732 clobber this info. */
5733 if (ecs
->event_thread
->stepping_over_watchpoint
)
5736 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5738 if (pending
!= NULL
)
5740 struct thread_info
*tp
= ecs
->event_thread
;
5741 struct regcache
*regcache
;
5743 infrun_debug_printf ("found resumed threads with "
5744 "pending events, saving status");
5746 gdb_assert (pending
!= tp
);
5748 /* Record the event thread's event for later. */
5749 save_waitstatus (tp
, &ecs
->ws
);
5750 /* This was cleared early, by handle_inferior_event. Set it
5751 so this pending event is considered by
5755 gdb_assert (!tp
->executing
);
5757 regcache
= get_thread_regcache (tp
);
5758 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5760 infrun_debug_printf ("saved stop_pc=%s for %s "
5761 "(currently_stepping=%d)",
5762 paddress (target_gdbarch (),
5763 tp
->suspend
.stop_pc
),
5764 target_pid_to_str (tp
->ptid
).c_str (),
5765 currently_stepping (tp
));
5767 /* This in-line step-over finished; clear this so we won't
5768 start a new one. This is what handle_signal_stop would
5769 do, if we returned false. */
5770 tp
->stepping_over_breakpoint
= 0;
5772 /* Wake up the event loop again. */
5773 mark_async_event_handler (infrun_async_inferior_event_token
);
5775 prepare_to_wait (ecs
);
5783 /* Come here when the program has stopped with a signal. */
5786 handle_signal_stop (struct execution_control_state
*ecs
)
5788 struct frame_info
*frame
;
5789 struct gdbarch
*gdbarch
;
5790 int stopped_by_watchpoint
;
5791 enum stop_kind stop_soon
;
5794 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5796 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5798 /* Do we need to clean up the state of a thread that has
5799 completed a displaced single-step? (Doing so usually affects
5800 the PC, so do it here, before we set stop_pc.) */
5801 if (finish_step_over (ecs
))
5804 /* If we either finished a single-step or hit a breakpoint, but
5805 the user wanted this thread to be stopped, pretend we got a
5806 SIG0 (generic unsignaled stop). */
5807 if (ecs
->event_thread
->stop_requested
5808 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5809 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5811 ecs
->event_thread
->suspend
.stop_pc
5812 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5816 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5817 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5819 switch_to_thread (ecs
->event_thread
);
5821 infrun_debug_printf ("stop_pc=%s",
5822 paddress (reg_gdbarch
,
5823 ecs
->event_thread
->suspend
.stop_pc
));
5824 if (target_stopped_by_watchpoint ())
5828 infrun_debug_printf ("stopped by watchpoint");
5830 if (target_stopped_data_address (current_top_target (), &addr
))
5831 infrun_debug_printf ("stopped data address=%s",
5832 paddress (reg_gdbarch
, addr
));
5834 infrun_debug_printf ("(no data address available)");
5838 /* This is originated from start_remote(), start_inferior() and
5839 shared libraries hook functions. */
5840 stop_soon
= get_inferior_stop_soon (ecs
);
5841 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5843 context_switch (ecs
);
5844 infrun_debug_printf ("quietly stopped");
5845 stop_print_frame
= true;
5850 /* This originates from attach_command(). We need to overwrite
5851 the stop_signal here, because some kernels don't ignore a
5852 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5853 See more comments in inferior.h. On the other hand, if we
5854 get a non-SIGSTOP, report it to the user - assume the backend
5855 will handle the SIGSTOP if it should show up later.
5857 Also consider that the attach is complete when we see a
5858 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5859 target extended-remote report it instead of a SIGSTOP
5860 (e.g. gdbserver). We already rely on SIGTRAP being our
5861 signal, so this is no exception.
5863 Also consider that the attach is complete when we see a
5864 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5865 the target to stop all threads of the inferior, in case the
5866 low level attach operation doesn't stop them implicitly. If
5867 they weren't stopped implicitly, then the stub will report a
5868 GDB_SIGNAL_0, meaning: stopped for no particular reason
5869 other than GDB's request. */
5870 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5871 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5872 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5873 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5875 stop_print_frame
= true;
5877 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5881 /* See if something interesting happened to the non-current thread. If
5882 so, then switch to that thread. */
5883 if (ecs
->ptid
!= inferior_ptid
)
5885 infrun_debug_printf ("context switch");
5887 context_switch (ecs
);
5889 if (deprecated_context_hook
)
5890 deprecated_context_hook (ecs
->event_thread
->global_num
);
5893 /* At this point, get hold of the now-current thread's frame. */
5894 frame
= get_current_frame ();
5895 gdbarch
= get_frame_arch (frame
);
5897 /* Pull the single step breakpoints out of the target. */
5898 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5900 struct regcache
*regcache
;
5903 regcache
= get_thread_regcache (ecs
->event_thread
);
5904 const address_space
*aspace
= regcache
->aspace ();
5906 pc
= regcache_read_pc (regcache
);
5908 /* However, before doing so, if this single-step breakpoint was
5909 actually for another thread, set this thread up for moving
5911 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5914 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5916 infrun_debug_printf ("[%s] hit another thread's single-step "
5918 target_pid_to_str (ecs
->ptid
).c_str ());
5919 ecs
->hit_singlestep_breakpoint
= 1;
5924 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5925 target_pid_to_str (ecs
->ptid
).c_str ());
5928 delete_just_stopped_threads_single_step_breakpoints ();
5930 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5931 && ecs
->event_thread
->control
.trap_expected
5932 && ecs
->event_thread
->stepping_over_watchpoint
)
5933 stopped_by_watchpoint
= 0;
5935 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5937 /* If necessary, step over this watchpoint. We'll be back to display
5939 if (stopped_by_watchpoint
5940 && (target_have_steppable_watchpoint ()
5941 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5943 /* At this point, we are stopped at an instruction which has
5944 attempted to write to a piece of memory under control of
5945 a watchpoint. The instruction hasn't actually executed
5946 yet. If we were to evaluate the watchpoint expression
5947 now, we would get the old value, and therefore no change
5948 would seem to have occurred.
5950 In order to make watchpoints work `right', we really need
5951 to complete the memory write, and then evaluate the
5952 watchpoint expression. We do this by single-stepping the
5955 It may not be necessary to disable the watchpoint to step over
5956 it. For example, the PA can (with some kernel cooperation)
5957 single step over a watchpoint without disabling the watchpoint.
5959 It is far more common to need to disable a watchpoint to step
5960 the inferior over it. If we have non-steppable watchpoints,
5961 we must disable the current watchpoint; it's simplest to
5962 disable all watchpoints.
5964 Any breakpoint at PC must also be stepped over -- if there's
5965 one, it will have already triggered before the watchpoint
5966 triggered, and we either already reported it to the user, or
5967 it didn't cause a stop and we called keep_going. In either
5968 case, if there was a breakpoint at PC, we must be trying to
5970 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5975 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5976 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5977 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5978 ecs
->event_thread
->control
.stop_step
= 0;
5979 stop_print_frame
= true;
5980 stopped_by_random_signal
= 0;
5981 bpstat stop_chain
= NULL
;
5983 /* Hide inlined functions starting here, unless we just performed stepi or
5984 nexti. After stepi and nexti, always show the innermost frame (not any
5985 inline function call sites). */
5986 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5988 const address_space
*aspace
5989 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5991 /* skip_inline_frames is expensive, so we avoid it if we can
5992 determine that the address is one where functions cannot have
5993 been inlined. This improves performance with inferiors that
5994 load a lot of shared libraries, because the solib event
5995 breakpoint is defined as the address of a function (i.e. not
5996 inline). Note that we have to check the previous PC as well
5997 as the current one to catch cases when we have just
5998 single-stepped off a breakpoint prior to reinstating it.
5999 Note that we're assuming that the code we single-step to is
6000 not inline, but that's not definitive: there's nothing
6001 preventing the event breakpoint function from containing
6002 inlined code, and the single-step ending up there. If the
6003 user had set a breakpoint on that inlined code, the missing
6004 skip_inline_frames call would break things. Fortunately
6005 that's an extremely unlikely scenario. */
6006 if (!pc_at_non_inline_function (aspace
,
6007 ecs
->event_thread
->suspend
.stop_pc
,
6009 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6010 && ecs
->event_thread
->control
.trap_expected
6011 && pc_at_non_inline_function (aspace
,
6012 ecs
->event_thread
->prev_pc
,
6015 stop_chain
= build_bpstat_chain (aspace
,
6016 ecs
->event_thread
->suspend
.stop_pc
,
6018 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6020 /* Re-fetch current thread's frame in case that invalidated
6022 frame
= get_current_frame ();
6023 gdbarch
= get_frame_arch (frame
);
6027 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6028 && ecs
->event_thread
->control
.trap_expected
6029 && gdbarch_single_step_through_delay_p (gdbarch
)
6030 && currently_stepping (ecs
->event_thread
))
6032 /* We're trying to step off a breakpoint. Turns out that we're
6033 also on an instruction that needs to be stepped multiple
6034 times before it's been fully executing. E.g., architectures
6035 with a delay slot. It needs to be stepped twice, once for
6036 the instruction and once for the delay slot. */
6037 int step_through_delay
6038 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6040 if (step_through_delay
)
6041 infrun_debug_printf ("step through delay");
6043 if (ecs
->event_thread
->control
.step_range_end
== 0
6044 && step_through_delay
)
6046 /* The user issued a continue when stopped at a breakpoint.
6047 Set up for another trap and get out of here. */
6048 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6052 else if (step_through_delay
)
6054 /* The user issued a step when stopped at a breakpoint.
6055 Maybe we should stop, maybe we should not - the delay
6056 slot *might* correspond to a line of source. In any
6057 case, don't decide that here, just set
6058 ecs->stepping_over_breakpoint, making sure we
6059 single-step again before breakpoints are re-inserted. */
6060 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6064 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6065 handles this event. */
6066 ecs
->event_thread
->control
.stop_bpstat
6067 = bpstat_stop_status (get_current_regcache ()->aspace (),
6068 ecs
->event_thread
->suspend
.stop_pc
,
6069 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6071 /* Following in case break condition called a
6073 stop_print_frame
= true;
6075 /* This is where we handle "moribund" watchpoints. Unlike
6076 software breakpoints traps, hardware watchpoint traps are
6077 always distinguishable from random traps. If no high-level
6078 watchpoint is associated with the reported stop data address
6079 anymore, then the bpstat does not explain the signal ---
6080 simply make sure to ignore it if `stopped_by_watchpoint' is
6083 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6084 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6086 && stopped_by_watchpoint
)
6088 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6092 /* NOTE: cagney/2003-03-29: These checks for a random signal
6093 at one stage in the past included checks for an inferior
6094 function call's call dummy's return breakpoint. The original
6095 comment, that went with the test, read:
6097 ``End of a stack dummy. Some systems (e.g. Sony news) give
6098 another signal besides SIGTRAP, so check here as well as
6101 If someone ever tries to get call dummys on a
6102 non-executable stack to work (where the target would stop
6103 with something like a SIGSEGV), then those tests might need
6104 to be re-instated. Given, however, that the tests were only
6105 enabled when momentary breakpoints were not being used, I
6106 suspect that it won't be the case.
6108 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6109 be necessary for call dummies on a non-executable stack on
6112 /* See if the breakpoints module can explain the signal. */
6114 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6115 ecs
->event_thread
->suspend
.stop_signal
);
6117 /* Maybe this was a trap for a software breakpoint that has since
6119 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6121 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6122 ecs
->event_thread
->suspend
.stop_pc
))
6124 struct regcache
*regcache
;
6127 /* Re-adjust PC to what the program would see if GDB was not
6129 regcache
= get_thread_regcache (ecs
->event_thread
);
6130 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6133 gdb::optional
<scoped_restore_tmpl
<int>>
6134 restore_operation_disable
;
6136 if (record_full_is_used ())
6137 restore_operation_disable
.emplace
6138 (record_full_gdb_operation_disable_set ());
6140 regcache_write_pc (regcache
,
6141 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6146 /* A delayed software breakpoint event. Ignore the trap. */
6147 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6152 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6153 has since been removed. */
6154 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6156 /* A delayed hardware breakpoint event. Ignore the trap. */
6157 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6162 /* If not, perhaps stepping/nexting can. */
6164 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6165 && currently_stepping (ecs
->event_thread
));
6167 /* Perhaps the thread hit a single-step breakpoint of _another_
6168 thread. Single-step breakpoints are transparent to the
6169 breakpoints module. */
6171 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6173 /* No? Perhaps we got a moribund watchpoint. */
6175 random_signal
= !stopped_by_watchpoint
;
6177 /* Always stop if the user explicitly requested this thread to
6179 if (ecs
->event_thread
->stop_requested
)
6182 infrun_debug_printf ("user-requested stop");
6185 /* For the program's own signals, act according to
6186 the signal handling tables. */
6190 /* Signal not for debugging purposes. */
6191 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6192 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6194 infrun_debug_printf ("random signal (%s)",
6195 gdb_signal_to_symbol_string (stop_signal
));
6197 stopped_by_random_signal
= 1;
6199 /* Always stop on signals if we're either just gaining control
6200 of the program, or the user explicitly requested this thread
6201 to remain stopped. */
6202 if (stop_soon
!= NO_STOP_QUIETLY
6203 || ecs
->event_thread
->stop_requested
6205 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6211 /* Notify observers the signal has "handle print" set. Note we
6212 returned early above if stopping; normal_stop handles the
6213 printing in that case. */
6214 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6216 /* The signal table tells us to print about this signal. */
6217 target_terminal::ours_for_output ();
6218 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6219 target_terminal::inferior ();
6222 /* Clear the signal if it should not be passed. */
6223 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6224 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6226 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6227 && ecs
->event_thread
->control
.trap_expected
6228 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6230 /* We were just starting a new sequence, attempting to
6231 single-step off of a breakpoint and expecting a SIGTRAP.
6232 Instead this signal arrives. This signal will take us out
6233 of the stepping range so GDB needs to remember to, when
6234 the signal handler returns, resume stepping off that
6236 /* To simplify things, "continue" is forced to use the same
6237 code paths as single-step - set a breakpoint at the
6238 signal return address and then, once hit, step off that
6240 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6242 insert_hp_step_resume_breakpoint_at_frame (frame
);
6243 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6244 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6245 ecs
->event_thread
->control
.trap_expected
= 0;
6247 /* If we were nexting/stepping some other thread, switch to
6248 it, so that we don't continue it, losing control. */
6249 if (!switch_back_to_stepped_thread (ecs
))
6254 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6255 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6257 || ecs
->event_thread
->control
.step_range_end
== 1)
6258 && frame_id_eq (get_stack_frame_id (frame
),
6259 ecs
->event_thread
->control
.step_stack_frame_id
)
6260 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6262 /* The inferior is about to take a signal that will take it
6263 out of the single step range. Set a breakpoint at the
6264 current PC (which is presumably where the signal handler
6265 will eventually return) and then allow the inferior to
6268 Note that this is only needed for a signal delivered
6269 while in the single-step range. Nested signals aren't a
6270 problem as they eventually all return. */
6271 infrun_debug_printf ("signal may take us out of single-step range");
6273 clear_step_over_info ();
6274 insert_hp_step_resume_breakpoint_at_frame (frame
);
6275 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6276 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6277 ecs
->event_thread
->control
.trap_expected
= 0;
6282 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6283 when either there's a nested signal, or when there's a
6284 pending signal enabled just as the signal handler returns
6285 (leaving the inferior at the step-resume-breakpoint without
6286 actually executing it). Either way continue until the
6287 breakpoint is really hit. */
6289 if (!switch_back_to_stepped_thread (ecs
))
6291 infrun_debug_printf ("random signal, keep going");
6298 process_event_stop_test (ecs
);
6301 /* Come here when we've got some debug event / signal we can explain
6302 (IOW, not a random signal), and test whether it should cause a
6303 stop, or whether we should resume the inferior (transparently).
6304 E.g., could be a breakpoint whose condition evaluates false; we
6305 could be still stepping within the line; etc. */
6308 process_event_stop_test (struct execution_control_state
*ecs
)
6310 struct symtab_and_line stop_pc_sal
;
6311 struct frame_info
*frame
;
6312 struct gdbarch
*gdbarch
;
6313 CORE_ADDR jmp_buf_pc
;
6314 struct bpstat_what what
;
6316 /* Handle cases caused by hitting a breakpoint. */
6318 frame
= get_current_frame ();
6319 gdbarch
= get_frame_arch (frame
);
6321 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6323 if (what
.call_dummy
)
6325 stop_stack_dummy
= what
.call_dummy
;
6328 /* A few breakpoint types have callbacks associated (e.g.,
6329 bp_jit_event). Run them now. */
6330 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6332 /* If we hit an internal event that triggers symbol changes, the
6333 current frame will be invalidated within bpstat_what (e.g., if we
6334 hit an internal solib event). Re-fetch it. */
6335 frame
= get_current_frame ();
6336 gdbarch
= get_frame_arch (frame
);
6338 switch (what
.main_action
)
6340 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6341 /* If we hit the breakpoint at longjmp while stepping, we
6342 install a momentary breakpoint at the target of the
6345 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6347 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6349 if (what
.is_longjmp
)
6351 struct value
*arg_value
;
6353 /* If we set the longjmp breakpoint via a SystemTap probe,
6354 then use it to extract the arguments. The destination PC
6355 is the third argument to the probe. */
6356 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6359 jmp_buf_pc
= value_as_address (arg_value
);
6360 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6362 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6363 || !gdbarch_get_longjmp_target (gdbarch
,
6364 frame
, &jmp_buf_pc
))
6366 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6367 "(!gdbarch_get_longjmp_target)");
6372 /* Insert a breakpoint at resume address. */
6373 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6376 check_exception_resume (ecs
, frame
);
6380 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6382 struct frame_info
*init_frame
;
6384 /* There are several cases to consider.
6386 1. The initiating frame no longer exists. In this case we
6387 must stop, because the exception or longjmp has gone too
6390 2. The initiating frame exists, and is the same as the
6391 current frame. We stop, because the exception or longjmp
6394 3. The initiating frame exists and is different from the
6395 current frame. This means the exception or longjmp has
6396 been caught beneath the initiating frame, so keep going.
6398 4. longjmp breakpoint has been placed just to protect
6399 against stale dummy frames and user is not interested in
6400 stopping around longjmps. */
6402 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6404 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6406 delete_exception_resume_breakpoint (ecs
->event_thread
);
6408 if (what
.is_longjmp
)
6410 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6412 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6420 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6424 struct frame_id current_id
6425 = get_frame_id (get_current_frame ());
6426 if (frame_id_eq (current_id
,
6427 ecs
->event_thread
->initiating_frame
))
6429 /* Case 2. Fall through. */
6439 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6441 delete_step_resume_breakpoint (ecs
->event_thread
);
6443 end_stepping_range (ecs
);
6447 case BPSTAT_WHAT_SINGLE
:
6448 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6449 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6450 /* Still need to check other stuff, at least the case where we
6451 are stepping and step out of the right range. */
6454 case BPSTAT_WHAT_STEP_RESUME
:
6455 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6457 delete_step_resume_breakpoint (ecs
->event_thread
);
6458 if (ecs
->event_thread
->control
.proceed_to_finish
6459 && execution_direction
== EXEC_REVERSE
)
6461 struct thread_info
*tp
= ecs
->event_thread
;
6463 /* We are finishing a function in reverse, and just hit the
6464 step-resume breakpoint at the start address of the
6465 function, and we're almost there -- just need to back up
6466 by one more single-step, which should take us back to the
6468 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6472 fill_in_stop_func (gdbarch
, ecs
);
6473 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6474 && execution_direction
== EXEC_REVERSE
)
6476 /* We are stepping over a function call in reverse, and just
6477 hit the step-resume breakpoint at the start address of
6478 the function. Go back to single-stepping, which should
6479 take us back to the function call. */
6480 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6486 case BPSTAT_WHAT_STOP_NOISY
:
6487 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6488 stop_print_frame
= true;
6490 /* Assume the thread stopped for a breakpoint. We'll still check
6491 whether a/the breakpoint is there when the thread is next
6493 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6498 case BPSTAT_WHAT_STOP_SILENT
:
6499 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6500 stop_print_frame
= false;
6502 /* Assume the thread stopped for a breakpoint. We'll still check
6503 whether a/the breakpoint is there when the thread is next
6505 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6509 case BPSTAT_WHAT_HP_STEP_RESUME
:
6510 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6512 delete_step_resume_breakpoint (ecs
->event_thread
);
6513 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6515 /* Back when the step-resume breakpoint was inserted, we
6516 were trying to single-step off a breakpoint. Go back to
6518 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6519 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6525 case BPSTAT_WHAT_KEEP_CHECKING
:
6529 /* If we stepped a permanent breakpoint and we had a high priority
6530 step-resume breakpoint for the address we stepped, but we didn't
6531 hit it, then we must have stepped into the signal handler. The
6532 step-resume was only necessary to catch the case of _not_
6533 stepping into the handler, so delete it, and fall through to
6534 checking whether the step finished. */
6535 if (ecs
->event_thread
->stepped_breakpoint
)
6537 struct breakpoint
*sr_bp
6538 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6541 && sr_bp
->loc
->permanent
6542 && sr_bp
->type
== bp_hp_step_resume
6543 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6545 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6546 delete_step_resume_breakpoint (ecs
->event_thread
);
6547 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6551 /* We come here if we hit a breakpoint but should not stop for it.
6552 Possibly we also were stepping and should stop for that. So fall
6553 through and test for stepping. But, if not stepping, do not
6556 /* In all-stop mode, if we're currently stepping but have stopped in
6557 some other thread, we need to switch back to the stepped thread. */
6558 if (switch_back_to_stepped_thread (ecs
))
6561 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6563 infrun_debug_printf ("step-resume breakpoint is inserted");
6565 /* Having a step-resume breakpoint overrides anything
6566 else having to do with stepping commands until
6567 that breakpoint is reached. */
6572 if (ecs
->event_thread
->control
.step_range_end
== 0)
6574 infrun_debug_printf ("no stepping, continue");
6575 /* Likewise if we aren't even stepping. */
6580 /* Re-fetch current thread's frame in case the code above caused
6581 the frame cache to be re-initialized, making our FRAME variable
6582 a dangling pointer. */
6583 frame
= get_current_frame ();
6584 gdbarch
= get_frame_arch (frame
);
6585 fill_in_stop_func (gdbarch
, ecs
);
6587 /* If stepping through a line, keep going if still within it.
6589 Note that step_range_end is the address of the first instruction
6590 beyond the step range, and NOT the address of the last instruction
6593 Note also that during reverse execution, we may be stepping
6594 through a function epilogue and therefore must detect when
6595 the current-frame changes in the middle of a line. */
6597 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6599 && (execution_direction
!= EXEC_REVERSE
6600 || frame_id_eq (get_frame_id (frame
),
6601 ecs
->event_thread
->control
.step_frame_id
)))
6604 ("stepping inside range [%s-%s]",
6605 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6606 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6608 /* Tentatively re-enable range stepping; `resume' disables it if
6609 necessary (e.g., if we're stepping over a breakpoint or we
6610 have software watchpoints). */
6611 ecs
->event_thread
->control
.may_range_step
= 1;
6613 /* When stepping backward, stop at beginning of line range
6614 (unless it's the function entry point, in which case
6615 keep going back to the call point). */
6616 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6617 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6618 && stop_pc
!= ecs
->stop_func_start
6619 && execution_direction
== EXEC_REVERSE
)
6620 end_stepping_range (ecs
);
6627 /* We stepped out of the stepping range. */
6629 /* If we are stepping at the source level and entered the runtime
6630 loader dynamic symbol resolution code...
6632 EXEC_FORWARD: we keep on single stepping until we exit the run
6633 time loader code and reach the callee's address.
6635 EXEC_REVERSE: we've already executed the callee (backward), and
6636 the runtime loader code is handled just like any other
6637 undebuggable function call. Now we need only keep stepping
6638 backward through the trampoline code, and that's handled further
6639 down, so there is nothing for us to do here. */
6641 if (execution_direction
!= EXEC_REVERSE
6642 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6643 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6645 CORE_ADDR pc_after_resolver
=
6646 gdbarch_skip_solib_resolver (gdbarch
,
6647 ecs
->event_thread
->suspend
.stop_pc
);
6649 infrun_debug_printf ("stepped into dynsym resolve code");
6651 if (pc_after_resolver
)
6653 /* Set up a step-resume breakpoint at the address
6654 indicated by SKIP_SOLIB_RESOLVER. */
6655 symtab_and_line sr_sal
;
6656 sr_sal
.pc
= pc_after_resolver
;
6657 sr_sal
.pspace
= get_frame_program_space (frame
);
6659 insert_step_resume_breakpoint_at_sal (gdbarch
,
6660 sr_sal
, null_frame_id
);
6667 /* Step through an indirect branch thunk. */
6668 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6669 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6670 ecs
->event_thread
->suspend
.stop_pc
))
6672 infrun_debug_printf ("stepped into indirect branch thunk");
6677 if (ecs
->event_thread
->control
.step_range_end
!= 1
6678 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6679 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6680 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6682 infrun_debug_printf ("stepped into signal trampoline");
6683 /* The inferior, while doing a "step" or "next", has ended up in
6684 a signal trampoline (either by a signal being delivered or by
6685 the signal handler returning). Just single-step until the
6686 inferior leaves the trampoline (either by calling the handler
6692 /* If we're in the return path from a shared library trampoline,
6693 we want to proceed through the trampoline when stepping. */
6694 /* macro/2012-04-25: This needs to come before the subroutine
6695 call check below as on some targets return trampolines look
6696 like subroutine calls (MIPS16 return thunks). */
6697 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6698 ecs
->event_thread
->suspend
.stop_pc
,
6699 ecs
->stop_func_name
)
6700 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6702 /* Determine where this trampoline returns. */
6703 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6704 CORE_ADDR real_stop_pc
6705 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6707 infrun_debug_printf ("stepped into solib return tramp");
6709 /* Only proceed through if we know where it's going. */
6712 /* And put the step-breakpoint there and go until there. */
6713 symtab_and_line sr_sal
;
6714 sr_sal
.pc
= real_stop_pc
;
6715 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6716 sr_sal
.pspace
= get_frame_program_space (frame
);
6718 /* Do not specify what the fp should be when we stop since
6719 on some machines the prologue is where the new fp value
6721 insert_step_resume_breakpoint_at_sal (gdbarch
,
6722 sr_sal
, null_frame_id
);
6724 /* Restart without fiddling with the step ranges or
6731 /* Check for subroutine calls. The check for the current frame
6732 equalling the step ID is not necessary - the check of the
6733 previous frame's ID is sufficient - but it is a common case and
6734 cheaper than checking the previous frame's ID.
6736 NOTE: frame_id_eq will never report two invalid frame IDs as
6737 being equal, so to get into this block, both the current and
6738 previous frame must have valid frame IDs. */
6739 /* The outer_frame_id check is a heuristic to detect stepping
6740 through startup code. If we step over an instruction which
6741 sets the stack pointer from an invalid value to a valid value,
6742 we may detect that as a subroutine call from the mythical
6743 "outermost" function. This could be fixed by marking
6744 outermost frames as !stack_p,code_p,special_p. Then the
6745 initial outermost frame, before sp was valid, would
6746 have code_addr == &_start. See the comment in frame_id_eq
6748 if (!frame_id_eq (get_stack_frame_id (frame
),
6749 ecs
->event_thread
->control
.step_stack_frame_id
)
6750 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6751 ecs
->event_thread
->control
.step_stack_frame_id
)
6752 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6754 || (ecs
->event_thread
->control
.step_start_function
6755 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6757 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6758 CORE_ADDR real_stop_pc
;
6760 infrun_debug_printf ("stepped into subroutine");
6762 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6764 /* I presume that step_over_calls is only 0 when we're
6765 supposed to be stepping at the assembly language level
6766 ("stepi"). Just stop. */
6767 /* And this works the same backward as frontward. MVS */
6768 end_stepping_range (ecs
);
6772 /* Reverse stepping through solib trampolines. */
6774 if (execution_direction
== EXEC_REVERSE
6775 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6776 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6777 || (ecs
->stop_func_start
== 0
6778 && in_solib_dynsym_resolve_code (stop_pc
))))
6780 /* Any solib trampoline code can be handled in reverse
6781 by simply continuing to single-step. We have already
6782 executed the solib function (backwards), and a few
6783 steps will take us back through the trampoline to the
6789 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6791 /* We're doing a "next".
6793 Normal (forward) execution: set a breakpoint at the
6794 callee's return address (the address at which the caller
6797 Reverse (backward) execution. set the step-resume
6798 breakpoint at the start of the function that we just
6799 stepped into (backwards), and continue to there. When we
6800 get there, we'll need to single-step back to the caller. */
6802 if (execution_direction
== EXEC_REVERSE
)
6804 /* If we're already at the start of the function, we've either
6805 just stepped backward into a single instruction function,
6806 or stepped back out of a signal handler to the first instruction
6807 of the function. Just keep going, which will single-step back
6809 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6811 /* Normal function call return (static or dynamic). */
6812 symtab_and_line sr_sal
;
6813 sr_sal
.pc
= ecs
->stop_func_start
;
6814 sr_sal
.pspace
= get_frame_program_space (frame
);
6815 insert_step_resume_breakpoint_at_sal (gdbarch
,
6816 sr_sal
, null_frame_id
);
6820 insert_step_resume_breakpoint_at_caller (frame
);
6826 /* If we are in a function call trampoline (a stub between the
6827 calling routine and the real function), locate the real
6828 function. That's what tells us (a) whether we want to step
6829 into it at all, and (b) what prologue we want to run to the
6830 end of, if we do step into it. */
6831 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6832 if (real_stop_pc
== 0)
6833 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6834 if (real_stop_pc
!= 0)
6835 ecs
->stop_func_start
= real_stop_pc
;
6837 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6839 symtab_and_line sr_sal
;
6840 sr_sal
.pc
= ecs
->stop_func_start
;
6841 sr_sal
.pspace
= get_frame_program_space (frame
);
6843 insert_step_resume_breakpoint_at_sal (gdbarch
,
6844 sr_sal
, null_frame_id
);
6849 /* If we have line number information for the function we are
6850 thinking of stepping into and the function isn't on the skip
6853 If there are several symtabs at that PC (e.g. with include
6854 files), just want to know whether *any* of them have line
6855 numbers. find_pc_line handles this. */
6857 struct symtab_and_line tmp_sal
;
6859 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6860 if (tmp_sal
.line
!= 0
6861 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6863 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6865 if (execution_direction
== EXEC_REVERSE
)
6866 handle_step_into_function_backward (gdbarch
, ecs
);
6868 handle_step_into_function (gdbarch
, ecs
);
6873 /* If we have no line number and the step-stop-if-no-debug is
6874 set, we stop the step so that the user has a chance to switch
6875 in assembly mode. */
6876 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6877 && step_stop_if_no_debug
)
6879 end_stepping_range (ecs
);
6883 if (execution_direction
== EXEC_REVERSE
)
6885 /* If we're already at the start of the function, we've either just
6886 stepped backward into a single instruction function without line
6887 number info, or stepped back out of a signal handler to the first
6888 instruction of the function without line number info. Just keep
6889 going, which will single-step back to the caller. */
6890 if (ecs
->stop_func_start
!= stop_pc
)
6892 /* Set a breakpoint at callee's start address.
6893 From there we can step once and be back in the caller. */
6894 symtab_and_line sr_sal
;
6895 sr_sal
.pc
= ecs
->stop_func_start
;
6896 sr_sal
.pspace
= get_frame_program_space (frame
);
6897 insert_step_resume_breakpoint_at_sal (gdbarch
,
6898 sr_sal
, null_frame_id
);
6902 /* Set a breakpoint at callee's return address (the address
6903 at which the caller will resume). */
6904 insert_step_resume_breakpoint_at_caller (frame
);
6910 /* Reverse stepping through solib trampolines. */
6912 if (execution_direction
== EXEC_REVERSE
6913 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6915 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6917 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6918 || (ecs
->stop_func_start
== 0
6919 && in_solib_dynsym_resolve_code (stop_pc
)))
6921 /* Any solib trampoline code can be handled in reverse
6922 by simply continuing to single-step. We have already
6923 executed the solib function (backwards), and a few
6924 steps will take us back through the trampoline to the
6929 else if (in_solib_dynsym_resolve_code (stop_pc
))
6931 /* Stepped backward into the solib dynsym resolver.
6932 Set a breakpoint at its start and continue, then
6933 one more step will take us out. */
6934 symtab_and_line sr_sal
;
6935 sr_sal
.pc
= ecs
->stop_func_start
;
6936 sr_sal
.pspace
= get_frame_program_space (frame
);
6937 insert_step_resume_breakpoint_at_sal (gdbarch
,
6938 sr_sal
, null_frame_id
);
6944 /* This always returns the sal for the inner-most frame when we are in a
6945 stack of inlined frames, even if GDB actually believes that it is in a
6946 more outer frame. This is checked for below by calls to
6947 inline_skipped_frames. */
6948 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6950 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6951 the trampoline processing logic, however, there are some trampolines
6952 that have no names, so we should do trampoline handling first. */
6953 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6954 && ecs
->stop_func_name
== NULL
6955 && stop_pc_sal
.line
== 0)
6957 infrun_debug_printf ("stepped into undebuggable function");
6959 /* The inferior just stepped into, or returned to, an
6960 undebuggable function (where there is no debugging information
6961 and no line number corresponding to the address where the
6962 inferior stopped). Since we want to skip this kind of code,
6963 we keep going until the inferior returns from this
6964 function - unless the user has asked us not to (via
6965 set step-mode) or we no longer know how to get back
6966 to the call site. */
6967 if (step_stop_if_no_debug
6968 || !frame_id_p (frame_unwind_caller_id (frame
)))
6970 /* If we have no line number and the step-stop-if-no-debug
6971 is set, we stop the step so that the user has a chance to
6972 switch in assembly mode. */
6973 end_stepping_range (ecs
);
6978 /* Set a breakpoint at callee's return address (the address
6979 at which the caller will resume). */
6980 insert_step_resume_breakpoint_at_caller (frame
);
6986 if (ecs
->event_thread
->control
.step_range_end
== 1)
6988 /* It is stepi or nexti. We always want to stop stepping after
6990 infrun_debug_printf ("stepi/nexti");
6991 end_stepping_range (ecs
);
6995 if (stop_pc_sal
.line
== 0)
6997 /* We have no line number information. That means to stop
6998 stepping (does this always happen right after one instruction,
6999 when we do "s" in a function with no line numbers,
7000 or can this happen as a result of a return or longjmp?). */
7001 infrun_debug_printf ("line number info");
7002 end_stepping_range (ecs
);
7006 /* Look for "calls" to inlined functions, part one. If the inline
7007 frame machinery detected some skipped call sites, we have entered
7008 a new inline function. */
7010 if (frame_id_eq (get_frame_id (get_current_frame ()),
7011 ecs
->event_thread
->control
.step_frame_id
)
7012 && inline_skipped_frames (ecs
->event_thread
))
7014 infrun_debug_printf ("stepped into inlined function");
7016 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7018 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7020 /* For "step", we're going to stop. But if the call site
7021 for this inlined function is on the same source line as
7022 we were previously stepping, go down into the function
7023 first. Otherwise stop at the call site. */
7025 if (call_sal
.line
== ecs
->event_thread
->current_line
7026 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7028 step_into_inline_frame (ecs
->event_thread
);
7029 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7036 end_stepping_range (ecs
);
7041 /* For "next", we should stop at the call site if it is on a
7042 different source line. Otherwise continue through the
7043 inlined function. */
7044 if (call_sal
.line
== ecs
->event_thread
->current_line
7045 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7048 end_stepping_range (ecs
);
7053 /* Look for "calls" to inlined functions, part two. If we are still
7054 in the same real function we were stepping through, but we have
7055 to go further up to find the exact frame ID, we are stepping
7056 through a more inlined call beyond its call site. */
7058 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7059 && !frame_id_eq (get_frame_id (get_current_frame ()),
7060 ecs
->event_thread
->control
.step_frame_id
)
7061 && stepped_in_from (get_current_frame (),
7062 ecs
->event_thread
->control
.step_frame_id
))
7064 infrun_debug_printf ("stepping through inlined function");
7066 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7067 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7070 end_stepping_range (ecs
);
7074 bool refresh_step_info
= true;
7075 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7076 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7077 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7079 if (stop_pc_sal
.is_stmt
)
7081 /* We are at the start of a different line. So stop. Note that
7082 we don't stop if we step into the middle of a different line.
7083 That is said to make things like for (;;) statements work
7085 infrun_debug_printf ("stepped to a different line");
7086 end_stepping_range (ecs
);
7089 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7090 ecs
->event_thread
->control
.step_frame_id
))
7092 /* We are at the start of a different line, however, this line is
7093 not marked as a statement, and we have not changed frame. We
7094 ignore this line table entry, and continue stepping forward,
7095 looking for a better place to stop. */
7096 refresh_step_info
= false;
7097 infrun_debug_printf ("stepped to a different line, but "
7098 "it's not the start of a statement");
7102 /* We aren't done stepping.
7104 Optimize by setting the stepping range to the line.
7105 (We might not be in the original line, but if we entered a
7106 new line in mid-statement, we continue stepping. This makes
7107 things like for(;;) statements work better.)
7109 If we entered a SAL that indicates a non-statement line table entry,
7110 then we update the stepping range, but we don't update the step info,
7111 which includes things like the line number we are stepping away from.
7112 This means we will stop when we find a line table entry that is marked
7113 as is-statement, even if it matches the non-statement one we just
7116 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7117 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7118 ecs
->event_thread
->control
.may_range_step
= 1;
7119 if (refresh_step_info
)
7120 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7122 infrun_debug_printf ("keep going");
7126 /* In all-stop mode, if we're currently stepping but have stopped in
7127 some other thread, we may need to switch back to the stepped
7128 thread. Returns true we set the inferior running, false if we left
7129 it stopped (and the event needs further processing). */
7132 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7134 if (!target_is_non_stop_p ())
7136 struct thread_info
*stepping_thread
;
7138 /* If any thread is blocked on some internal breakpoint, and we
7139 simply need to step over that breakpoint to get it going
7140 again, do that first. */
7142 /* However, if we see an event for the stepping thread, then we
7143 know all other threads have been moved past their breakpoints
7144 already. Let the caller check whether the step is finished,
7145 etc., before deciding to move it past a breakpoint. */
7146 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7149 /* Check if the current thread is blocked on an incomplete
7150 step-over, interrupted by a random signal. */
7151 if (ecs
->event_thread
->control
.trap_expected
7152 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7155 ("need to finish step-over of [%s]",
7156 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7161 /* Check if the current thread is blocked by a single-step
7162 breakpoint of another thread. */
7163 if (ecs
->hit_singlestep_breakpoint
)
7165 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7166 target_pid_to_str (ecs
->ptid
).c_str ());
7171 /* If this thread needs yet another step-over (e.g., stepping
7172 through a delay slot), do it first before moving on to
7174 if (thread_still_needs_step_over (ecs
->event_thread
))
7177 ("thread [%s] still needs step-over",
7178 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7183 /* If scheduler locking applies even if not stepping, there's no
7184 need to walk over threads. Above we've checked whether the
7185 current thread is stepping. If some other thread not the
7186 event thread is stepping, then it must be that scheduler
7187 locking is not in effect. */
7188 if (schedlock_applies (ecs
->event_thread
))
7191 /* Otherwise, we no longer expect a trap in the current thread.
7192 Clear the trap_expected flag before switching back -- this is
7193 what keep_going does as well, if we call it. */
7194 ecs
->event_thread
->control
.trap_expected
= 0;
7196 /* Likewise, clear the signal if it should not be passed. */
7197 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7198 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7200 /* Do all pending step-overs before actually proceeding with
7202 if (start_step_over ())
7204 prepare_to_wait (ecs
);
7208 /* Look for the stepping/nexting thread. */
7209 stepping_thread
= NULL
;
7211 for (thread_info
*tp
: all_non_exited_threads ())
7213 switch_to_thread_no_regs (tp
);
7215 /* Ignore threads of processes the caller is not
7218 && (tp
->inf
->process_target () != ecs
->target
7219 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7222 /* When stepping over a breakpoint, we lock all threads
7223 except the one that needs to move past the breakpoint.
7224 If a non-event thread has this set, the "incomplete
7225 step-over" check above should have caught it earlier. */
7226 if (tp
->control
.trap_expected
)
7228 internal_error (__FILE__
, __LINE__
,
7229 "[%s] has inconsistent state: "
7230 "trap_expected=%d\n",
7231 target_pid_to_str (tp
->ptid
).c_str (),
7232 tp
->control
.trap_expected
);
7235 /* Did we find the stepping thread? */
7236 if (tp
->control
.step_range_end
)
7238 /* Yep. There should only one though. */
7239 gdb_assert (stepping_thread
== NULL
);
7241 /* The event thread is handled at the top, before we
7243 gdb_assert (tp
!= ecs
->event_thread
);
7245 /* If some thread other than the event thread is
7246 stepping, then scheduler locking can't be in effect,
7247 otherwise we wouldn't have resumed the current event
7248 thread in the first place. */
7249 gdb_assert (!schedlock_applies (tp
));
7251 stepping_thread
= tp
;
7255 if (stepping_thread
!= NULL
)
7257 infrun_debug_printf ("switching back to stepped thread");
7259 if (keep_going_stepped_thread (stepping_thread
))
7261 prepare_to_wait (ecs
);
7266 switch_to_thread (ecs
->event_thread
);
7272 /* Set a previously stepped thread back to stepping. Returns true on
7273 success, false if the resume is not possible (e.g., the thread
7277 keep_going_stepped_thread (struct thread_info
*tp
)
7279 struct frame_info
*frame
;
7280 struct execution_control_state ecss
;
7281 struct execution_control_state
*ecs
= &ecss
;
7283 /* If the stepping thread exited, then don't try to switch back and
7284 resume it, which could fail in several different ways depending
7285 on the target. Instead, just keep going.
7287 We can find a stepping dead thread in the thread list in two
7290 - The target supports thread exit events, and when the target
7291 tries to delete the thread from the thread list, inferior_ptid
7292 pointed at the exiting thread. In such case, calling
7293 delete_thread does not really remove the thread from the list;
7294 instead, the thread is left listed, with 'exited' state.
7296 - The target's debug interface does not support thread exit
7297 events, and so we have no idea whatsoever if the previously
7298 stepping thread is still alive. For that reason, we need to
7299 synchronously query the target now. */
7301 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7303 infrun_debug_printf ("not resuming previously stepped thread, it has "
7310 infrun_debug_printf ("resuming previously stepped thread");
7312 reset_ecs (ecs
, tp
);
7313 switch_to_thread (tp
);
7315 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7316 frame
= get_current_frame ();
7318 /* If the PC of the thread we were trying to single-step has
7319 changed, then that thread has trapped or been signaled, but the
7320 event has not been reported to GDB yet. Re-poll the target
7321 looking for this particular thread's event (i.e. temporarily
7322 enable schedlock) by:
7324 - setting a break at the current PC
7325 - resuming that particular thread, only (by setting trap
7328 This prevents us continuously moving the single-step breakpoint
7329 forward, one instruction at a time, overstepping. */
7331 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7335 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7336 paddress (target_gdbarch (), tp
->prev_pc
),
7337 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7339 /* Clear the info of the previous step-over, as it's no longer
7340 valid (if the thread was trying to step over a breakpoint, it
7341 has already succeeded). It's what keep_going would do too,
7342 if we called it. Do this before trying to insert the sss
7343 breakpoint, otherwise if we were previously trying to step
7344 over this exact address in another thread, the breakpoint is
7346 clear_step_over_info ();
7347 tp
->control
.trap_expected
= 0;
7349 insert_single_step_breakpoint (get_frame_arch (frame
),
7350 get_frame_address_space (frame
),
7351 tp
->suspend
.stop_pc
);
7354 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7355 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7359 infrun_debug_printf ("expected thread still hasn't advanced");
7361 keep_going_pass_signal (ecs
);
7367 /* Is thread TP in the middle of (software or hardware)
7368 single-stepping? (Note the result of this function must never be
7369 passed directly as target_resume's STEP parameter.) */
7372 currently_stepping (struct thread_info
*tp
)
7374 return ((tp
->control
.step_range_end
7375 && tp
->control
.step_resume_breakpoint
== NULL
)
7376 || tp
->control
.trap_expected
7377 || tp
->stepped_breakpoint
7378 || bpstat_should_step ());
7381 /* Inferior has stepped into a subroutine call with source code that
7382 we should not step over. Do step to the first line of code in
7386 handle_step_into_function (struct gdbarch
*gdbarch
,
7387 struct execution_control_state
*ecs
)
7389 fill_in_stop_func (gdbarch
, ecs
);
7391 compunit_symtab
*cust
7392 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7393 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7394 ecs
->stop_func_start
7395 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7397 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7398 /* Use the step_resume_break to step until the end of the prologue,
7399 even if that involves jumps (as it seems to on the vax under
7401 /* If the prologue ends in the middle of a source line, continue to
7402 the end of that source line (if it is still within the function).
7403 Otherwise, just go to end of prologue. */
7404 if (stop_func_sal
.end
7405 && stop_func_sal
.pc
!= ecs
->stop_func_start
7406 && stop_func_sal
.end
< ecs
->stop_func_end
)
7407 ecs
->stop_func_start
= stop_func_sal
.end
;
7409 /* Architectures which require breakpoint adjustment might not be able
7410 to place a breakpoint at the computed address. If so, the test
7411 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7412 ecs->stop_func_start to an address at which a breakpoint may be
7413 legitimately placed.
7415 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7416 made, GDB will enter an infinite loop when stepping through
7417 optimized code consisting of VLIW instructions which contain
7418 subinstructions corresponding to different source lines. On
7419 FR-V, it's not permitted to place a breakpoint on any but the
7420 first subinstruction of a VLIW instruction. When a breakpoint is
7421 set, GDB will adjust the breakpoint address to the beginning of
7422 the VLIW instruction. Thus, we need to make the corresponding
7423 adjustment here when computing the stop address. */
7425 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7427 ecs
->stop_func_start
7428 = gdbarch_adjust_breakpoint_address (gdbarch
,
7429 ecs
->stop_func_start
);
7432 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7434 /* We are already there: stop now. */
7435 end_stepping_range (ecs
);
7440 /* Put the step-breakpoint there and go until there. */
7441 symtab_and_line sr_sal
;
7442 sr_sal
.pc
= ecs
->stop_func_start
;
7443 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7444 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7446 /* Do not specify what the fp should be when we stop since on
7447 some machines the prologue is where the new fp value is
7449 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7451 /* And make sure stepping stops right away then. */
7452 ecs
->event_thread
->control
.step_range_end
7453 = ecs
->event_thread
->control
.step_range_start
;
7458 /* Inferior has stepped backward into a subroutine call with source
7459 code that we should not step over. Do step to the beginning of the
7460 last line of code in it. */
7463 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7464 struct execution_control_state
*ecs
)
7466 struct compunit_symtab
*cust
;
7467 struct symtab_and_line stop_func_sal
;
7469 fill_in_stop_func (gdbarch
, ecs
);
7471 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7472 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7473 ecs
->stop_func_start
7474 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7476 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7478 /* OK, we're just going to keep stepping here. */
7479 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7481 /* We're there already. Just stop stepping now. */
7482 end_stepping_range (ecs
);
7486 /* Else just reset the step range and keep going.
7487 No step-resume breakpoint, they don't work for
7488 epilogues, which can have multiple entry paths. */
7489 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7490 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7496 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7497 This is used to both functions and to skip over code. */
7500 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7501 struct symtab_and_line sr_sal
,
7502 struct frame_id sr_id
,
7503 enum bptype sr_type
)
7505 /* There should never be more than one step-resume or longjmp-resume
7506 breakpoint per thread, so we should never be setting a new
7507 step_resume_breakpoint when one is already active. */
7508 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7509 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7511 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7512 paddress (gdbarch
, sr_sal
.pc
));
7514 inferior_thread ()->control
.step_resume_breakpoint
7515 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7519 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7520 struct symtab_and_line sr_sal
,
7521 struct frame_id sr_id
)
7523 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7528 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7529 This is used to skip a potential signal handler.
7531 This is called with the interrupted function's frame. The signal
7532 handler, when it returns, will resume the interrupted function at
7536 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7538 gdb_assert (return_frame
!= NULL
);
7540 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7542 symtab_and_line sr_sal
;
7543 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7544 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7545 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7547 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7548 get_stack_frame_id (return_frame
),
7552 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7553 is used to skip a function after stepping into it (for "next" or if
7554 the called function has no debugging information).
7556 The current function has almost always been reached by single
7557 stepping a call or return instruction. NEXT_FRAME belongs to the
7558 current function, and the breakpoint will be set at the caller's
7561 This is a separate function rather than reusing
7562 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7563 get_prev_frame, which may stop prematurely (see the implementation
7564 of frame_unwind_caller_id for an example). */
7567 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7569 /* We shouldn't have gotten here if we don't know where the call site
7571 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7573 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7575 symtab_and_line sr_sal
;
7576 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7577 frame_unwind_caller_pc (next_frame
));
7578 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7579 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7581 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7582 frame_unwind_caller_id (next_frame
));
7585 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7586 new breakpoint at the target of a jmp_buf. The handling of
7587 longjmp-resume uses the same mechanisms used for handling
7588 "step-resume" breakpoints. */
7591 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7593 /* There should never be more than one longjmp-resume breakpoint per
7594 thread, so we should never be setting a new
7595 longjmp_resume_breakpoint when one is already active. */
7596 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7598 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7599 paddress (gdbarch
, pc
));
7601 inferior_thread ()->control
.exception_resume_breakpoint
=
7602 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7605 /* Insert an exception resume breakpoint. TP is the thread throwing
7606 the exception. The block B is the block of the unwinder debug hook
7607 function. FRAME is the frame corresponding to the call to this
7608 function. SYM is the symbol of the function argument holding the
7609 target PC of the exception. */
7612 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7613 const struct block
*b
,
7614 struct frame_info
*frame
,
7619 struct block_symbol vsym
;
7620 struct value
*value
;
7622 struct breakpoint
*bp
;
7624 vsym
= lookup_symbol_search_name (sym
->search_name (),
7626 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7627 /* If the value was optimized out, revert to the old behavior. */
7628 if (! value_optimized_out (value
))
7630 handler
= value_as_address (value
);
7632 infrun_debug_printf ("exception resume at %lx",
7633 (unsigned long) handler
);
7635 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7637 bp_exception_resume
).release ();
7639 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7642 bp
->thread
= tp
->global_num
;
7643 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7646 catch (const gdb_exception_error
&e
)
7648 /* We want to ignore errors here. */
7652 /* A helper for check_exception_resume that sets an
7653 exception-breakpoint based on a SystemTap probe. */
7656 insert_exception_resume_from_probe (struct thread_info
*tp
,
7657 const struct bound_probe
*probe
,
7658 struct frame_info
*frame
)
7660 struct value
*arg_value
;
7662 struct breakpoint
*bp
;
7664 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7668 handler
= value_as_address (arg_value
);
7670 infrun_debug_printf ("exception resume at %s",
7671 paddress (probe
->objfile
->arch (), handler
));
7673 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7674 handler
, bp_exception_resume
).release ();
7675 bp
->thread
= tp
->global_num
;
7676 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7679 /* This is called when an exception has been intercepted. Check to
7680 see whether the exception's destination is of interest, and if so,
7681 set an exception resume breakpoint there. */
7684 check_exception_resume (struct execution_control_state
*ecs
,
7685 struct frame_info
*frame
)
7687 struct bound_probe probe
;
7688 struct symbol
*func
;
7690 /* First see if this exception unwinding breakpoint was set via a
7691 SystemTap probe point. If so, the probe has two arguments: the
7692 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7693 set a breakpoint there. */
7694 probe
= find_probe_by_pc (get_frame_pc (frame
));
7697 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7701 func
= get_frame_function (frame
);
7707 const struct block
*b
;
7708 struct block_iterator iter
;
7712 /* The exception breakpoint is a thread-specific breakpoint on
7713 the unwinder's debug hook, declared as:
7715 void _Unwind_DebugHook (void *cfa, void *handler);
7717 The CFA argument indicates the frame to which control is
7718 about to be transferred. HANDLER is the destination PC.
7720 We ignore the CFA and set a temporary breakpoint at HANDLER.
7721 This is not extremely efficient but it avoids issues in gdb
7722 with computing the DWARF CFA, and it also works even in weird
7723 cases such as throwing an exception from inside a signal
7726 b
= SYMBOL_BLOCK_VALUE (func
);
7727 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7729 if (!SYMBOL_IS_ARGUMENT (sym
))
7736 insert_exception_resume_breakpoint (ecs
->event_thread
,
7742 catch (const gdb_exception_error
&e
)
7748 stop_waiting (struct execution_control_state
*ecs
)
7750 infrun_debug_printf ("stop_waiting");
7752 /* Let callers know we don't want to wait for the inferior anymore. */
7753 ecs
->wait_some_more
= 0;
7755 /* If all-stop, but there exists a non-stop target, stop all
7756 threads now that we're presenting the stop to the user. */
7757 if (!non_stop
&& exists_non_stop_target ())
7758 stop_all_threads ();
7761 /* Like keep_going, but passes the signal to the inferior, even if the
7762 signal is set to nopass. */
7765 keep_going_pass_signal (struct execution_control_state
*ecs
)
7767 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7768 gdb_assert (!ecs
->event_thread
->resumed
);
7770 /* Save the pc before execution, to compare with pc after stop. */
7771 ecs
->event_thread
->prev_pc
7772 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7774 if (ecs
->event_thread
->control
.trap_expected
)
7776 struct thread_info
*tp
= ecs
->event_thread
;
7778 infrun_debug_printf ("%s has trap_expected set, "
7779 "resuming to collect trap",
7780 target_pid_to_str (tp
->ptid
).c_str ());
7782 /* We haven't yet gotten our trap, and either: intercepted a
7783 non-signal event (e.g., a fork); or took a signal which we
7784 are supposed to pass through to the inferior. Simply
7786 resume (ecs
->event_thread
->suspend
.stop_signal
);
7788 else if (step_over_info_valid_p ())
7790 /* Another thread is stepping over a breakpoint in-line. If
7791 this thread needs a step-over too, queue the request. In
7792 either case, this resume must be deferred for later. */
7793 struct thread_info
*tp
= ecs
->event_thread
;
7795 if (ecs
->hit_singlestep_breakpoint
7796 || thread_still_needs_step_over (tp
))
7798 infrun_debug_printf ("step-over already in progress: "
7799 "step-over for %s deferred",
7800 target_pid_to_str (tp
->ptid
).c_str ());
7801 thread_step_over_chain_enqueue (tp
);
7805 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7806 target_pid_to_str (tp
->ptid
).c_str ());
7811 struct regcache
*regcache
= get_current_regcache ();
7814 step_over_what step_what
;
7816 /* Either the trap was not expected, but we are continuing
7817 anyway (if we got a signal, the user asked it be passed to
7820 We got our expected trap, but decided we should resume from
7823 We're going to run this baby now!
7825 Note that insert_breakpoints won't try to re-insert
7826 already inserted breakpoints. Therefore, we don't
7827 care if breakpoints were already inserted, or not. */
7829 /* If we need to step over a breakpoint, and we're not using
7830 displaced stepping to do so, insert all breakpoints
7831 (watchpoints, etc.) but the one we're stepping over, step one
7832 instruction, and then re-insert the breakpoint when that step
7835 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7837 remove_bp
= (ecs
->hit_singlestep_breakpoint
7838 || (step_what
& STEP_OVER_BREAKPOINT
));
7839 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7841 /* We can't use displaced stepping if we need to step past a
7842 watchpoint. The instruction copied to the scratch pad would
7843 still trigger the watchpoint. */
7845 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7847 set_step_over_info (regcache
->aspace (),
7848 regcache_read_pc (regcache
), remove_wps
,
7849 ecs
->event_thread
->global_num
);
7851 else if (remove_wps
)
7852 set_step_over_info (NULL
, 0, remove_wps
, -1);
7854 /* If we now need to do an in-line step-over, we need to stop
7855 all other threads. Note this must be done before
7856 insert_breakpoints below, because that removes the breakpoint
7857 we're about to step over, otherwise other threads could miss
7859 if (step_over_info_valid_p () && target_is_non_stop_p ())
7860 stop_all_threads ();
7862 /* Stop stepping if inserting breakpoints fails. */
7865 insert_breakpoints ();
7867 catch (const gdb_exception_error
&e
)
7869 exception_print (gdb_stderr
, e
);
7871 clear_step_over_info ();
7875 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7877 resume (ecs
->event_thread
->suspend
.stop_signal
);
7880 prepare_to_wait (ecs
);
7883 /* Called when we should continue running the inferior, because the
7884 current event doesn't cause a user visible stop. This does the
7885 resuming part; waiting for the next event is done elsewhere. */
7888 keep_going (struct execution_control_state
*ecs
)
7890 if (ecs
->event_thread
->control
.trap_expected
7891 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7892 ecs
->event_thread
->control
.trap_expected
= 0;
7894 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7895 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7896 keep_going_pass_signal (ecs
);
7899 /* This function normally comes after a resume, before
7900 handle_inferior_event exits. It takes care of any last bits of
7901 housekeeping, and sets the all-important wait_some_more flag. */
7904 prepare_to_wait (struct execution_control_state
*ecs
)
7906 infrun_debug_printf ("prepare_to_wait");
7908 ecs
->wait_some_more
= 1;
7910 /* If the target can't async, emulate it by marking the infrun event
7911 handler such that as soon as we get back to the event-loop, we
7912 immediately end up in fetch_inferior_event again calling
7914 if (!target_can_async_p ())
7915 mark_infrun_async_event_handler ();
7918 /* We are done with the step range of a step/next/si/ni command.
7919 Called once for each n of a "step n" operation. */
7922 end_stepping_range (struct execution_control_state
*ecs
)
7924 ecs
->event_thread
->control
.stop_step
= 1;
7928 /* Several print_*_reason functions to print why the inferior has stopped.
7929 We always print something when the inferior exits, or receives a signal.
7930 The rest of the cases are dealt with later on in normal_stop and
7931 print_it_typical. Ideally there should be a call to one of these
7932 print_*_reason functions functions from handle_inferior_event each time
7933 stop_waiting is called.
7935 Note that we don't call these directly, instead we delegate that to
7936 the interpreters, through observers. Interpreters then call these
7937 with whatever uiout is right. */
7940 print_end_stepping_range_reason (struct ui_out
*uiout
)
7942 /* For CLI-like interpreters, print nothing. */
7944 if (uiout
->is_mi_like_p ())
7946 uiout
->field_string ("reason",
7947 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7952 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7954 annotate_signalled ();
7955 if (uiout
->is_mi_like_p ())
7957 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7958 uiout
->text ("\nProgram terminated with signal ");
7959 annotate_signal_name ();
7960 uiout
->field_string ("signal-name",
7961 gdb_signal_to_name (siggnal
));
7962 annotate_signal_name_end ();
7964 annotate_signal_string ();
7965 uiout
->field_string ("signal-meaning",
7966 gdb_signal_to_string (siggnal
));
7967 annotate_signal_string_end ();
7968 uiout
->text (".\n");
7969 uiout
->text ("The program no longer exists.\n");
7973 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7975 struct inferior
*inf
= current_inferior ();
7976 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7978 annotate_exited (exitstatus
);
7981 if (uiout
->is_mi_like_p ())
7982 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7983 std::string exit_code_str
7984 = string_printf ("0%o", (unsigned int) exitstatus
);
7985 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7986 plongest (inf
->num
), pidstr
.c_str (),
7987 string_field ("exit-code", exit_code_str
.c_str ()));
7991 if (uiout
->is_mi_like_p ())
7993 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7994 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7995 plongest (inf
->num
), pidstr
.c_str ());
8000 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8002 struct thread_info
*thr
= inferior_thread ();
8006 if (uiout
->is_mi_like_p ())
8008 else if (show_thread_that_caused_stop ())
8012 uiout
->text ("\nThread ");
8013 uiout
->field_string ("thread-id", print_thread_id (thr
));
8015 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8018 uiout
->text (" \"");
8019 uiout
->field_string ("name", name
);
8024 uiout
->text ("\nProgram");
8026 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8027 uiout
->text (" stopped");
8030 uiout
->text (" received signal ");
8031 annotate_signal_name ();
8032 if (uiout
->is_mi_like_p ())
8034 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8035 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8036 annotate_signal_name_end ();
8038 annotate_signal_string ();
8039 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8041 struct regcache
*regcache
= get_current_regcache ();
8042 struct gdbarch
*gdbarch
= regcache
->arch ();
8043 if (gdbarch_report_signal_info_p (gdbarch
))
8044 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8046 annotate_signal_string_end ();
8048 uiout
->text (".\n");
8052 print_no_history_reason (struct ui_out
*uiout
)
8054 uiout
->text ("\nNo more reverse-execution history.\n");
8057 /* Print current location without a level number, if we have changed
8058 functions or hit a breakpoint. Print source line if we have one.
8059 bpstat_print contains the logic deciding in detail what to print,
8060 based on the event(s) that just occurred. */
8063 print_stop_location (struct target_waitstatus
*ws
)
8066 enum print_what source_flag
;
8067 int do_frame_printing
= 1;
8068 struct thread_info
*tp
= inferior_thread ();
8070 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8074 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8075 should) carry around the function and does (or should) use
8076 that when doing a frame comparison. */
8077 if (tp
->control
.stop_step
8078 && frame_id_eq (tp
->control
.step_frame_id
,
8079 get_frame_id (get_current_frame ()))
8080 && (tp
->control
.step_start_function
8081 == find_pc_function (tp
->suspend
.stop_pc
)))
8083 /* Finished step, just print source line. */
8084 source_flag
= SRC_LINE
;
8088 /* Print location and source line. */
8089 source_flag
= SRC_AND_LOC
;
8092 case PRINT_SRC_AND_LOC
:
8093 /* Print location and source line. */
8094 source_flag
= SRC_AND_LOC
;
8096 case PRINT_SRC_ONLY
:
8097 source_flag
= SRC_LINE
;
8100 /* Something bogus. */
8101 source_flag
= SRC_LINE
;
8102 do_frame_printing
= 0;
8105 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8108 /* The behavior of this routine with respect to the source
8110 SRC_LINE: Print only source line
8111 LOCATION: Print only location
8112 SRC_AND_LOC: Print location and source line. */
8113 if (do_frame_printing
)
8114 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8120 print_stop_event (struct ui_out
*uiout
, bool displays
)
8122 struct target_waitstatus last
;
8123 struct thread_info
*tp
;
8125 get_last_target_status (nullptr, nullptr, &last
);
8128 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8130 print_stop_location (&last
);
8132 /* Display the auto-display expressions. */
8137 tp
= inferior_thread ();
8138 if (tp
->thread_fsm
!= NULL
8139 && tp
->thread_fsm
->finished_p ())
8141 struct return_value_info
*rv
;
8143 rv
= tp
->thread_fsm
->return_value ();
8145 print_return_value (uiout
, rv
);
8152 maybe_remove_breakpoints (void)
8154 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8156 if (remove_breakpoints ())
8158 target_terminal::ours_for_output ();
8159 printf_filtered (_("Cannot remove breakpoints because "
8160 "program is no longer writable.\nFurther "
8161 "execution is probably impossible.\n"));
8166 /* The execution context that just caused a normal stop. */
8173 DISABLE_COPY_AND_ASSIGN (stop_context
);
8175 bool changed () const;
8180 /* The event PTID. */
8184 /* If stopp for a thread event, this is the thread that caused the
8186 struct thread_info
*thread
;
8188 /* The inferior that caused the stop. */
8192 /* Initializes a new stop context. If stopped for a thread event, this
8193 takes a strong reference to the thread. */
8195 stop_context::stop_context ()
8197 stop_id
= get_stop_id ();
8198 ptid
= inferior_ptid
;
8199 inf_num
= current_inferior ()->num
;
8201 if (inferior_ptid
!= null_ptid
)
8203 /* Take a strong reference so that the thread can't be deleted
8205 thread
= inferior_thread ();
8212 /* Release a stop context previously created with save_stop_context.
8213 Releases the strong reference to the thread as well. */
8215 stop_context::~stop_context ()
8221 /* Return true if the current context no longer matches the saved stop
8225 stop_context::changed () const
8227 if (ptid
!= inferior_ptid
)
8229 if (inf_num
!= current_inferior ()->num
)
8231 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8233 if (get_stop_id () != stop_id
)
8243 struct target_waitstatus last
;
8245 get_last_target_status (nullptr, nullptr, &last
);
8249 /* If an exception is thrown from this point on, make sure to
8250 propagate GDB's knowledge of the executing state to the
8251 frontend/user running state. A QUIT is an easy exception to see
8252 here, so do this before any filtered output. */
8254 ptid_t finish_ptid
= null_ptid
;
8257 finish_ptid
= minus_one_ptid
;
8258 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8259 || last
.kind
== TARGET_WAITKIND_EXITED
)
8261 /* On some targets, we may still have live threads in the
8262 inferior when we get a process exit event. E.g., for
8263 "checkpoint", when the current checkpoint/fork exits,
8264 linux-fork.c automatically switches to another fork from
8265 within target_mourn_inferior. */
8266 if (inferior_ptid
!= null_ptid
)
8267 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8269 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8270 finish_ptid
= inferior_ptid
;
8272 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8273 if (finish_ptid
!= null_ptid
)
8275 maybe_finish_thread_state
.emplace
8276 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8279 /* As we're presenting a stop, and potentially removing breakpoints,
8280 update the thread list so we can tell whether there are threads
8281 running on the target. With target remote, for example, we can
8282 only learn about new threads when we explicitly update the thread
8283 list. Do this before notifying the interpreters about signal
8284 stops, end of stepping ranges, etc., so that the "new thread"
8285 output is emitted before e.g., "Program received signal FOO",
8286 instead of after. */
8287 update_thread_list ();
8289 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8290 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8292 /* As with the notification of thread events, we want to delay
8293 notifying the user that we've switched thread context until
8294 the inferior actually stops.
8296 There's no point in saying anything if the inferior has exited.
8297 Note that SIGNALLED here means "exited with a signal", not
8298 "received a signal".
8300 Also skip saying anything in non-stop mode. In that mode, as we
8301 don't want GDB to switch threads behind the user's back, to avoid
8302 races where the user is typing a command to apply to thread x,
8303 but GDB switches to thread y before the user finishes entering
8304 the command, fetch_inferior_event installs a cleanup to restore
8305 the current thread back to the thread the user had selected right
8306 after this event is handled, so we're not really switching, only
8307 informing of a stop. */
8309 && previous_inferior_ptid
!= inferior_ptid
8310 && target_has_execution ()
8311 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8312 && last
.kind
!= TARGET_WAITKIND_EXITED
8313 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8315 SWITCH_THRU_ALL_UIS ()
8317 target_terminal::ours_for_output ();
8318 printf_filtered (_("[Switching to %s]\n"),
8319 target_pid_to_str (inferior_ptid
).c_str ());
8320 annotate_thread_changed ();
8322 previous_inferior_ptid
= inferior_ptid
;
8325 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8327 SWITCH_THRU_ALL_UIS ()
8328 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8330 target_terminal::ours_for_output ();
8331 printf_filtered (_("No unwaited-for children left.\n"));
8335 /* Note: this depends on the update_thread_list call above. */
8336 maybe_remove_breakpoints ();
8338 /* If an auto-display called a function and that got a signal,
8339 delete that auto-display to avoid an infinite recursion. */
8341 if (stopped_by_random_signal
)
8342 disable_current_display ();
8344 SWITCH_THRU_ALL_UIS ()
8346 async_enable_stdin ();
8349 /* Let the user/frontend see the threads as stopped. */
8350 maybe_finish_thread_state
.reset ();
8352 /* Select innermost stack frame - i.e., current frame is frame 0,
8353 and current location is based on that. Handle the case where the
8354 dummy call is returning after being stopped. E.g. the dummy call
8355 previously hit a breakpoint. (If the dummy call returns
8356 normally, we won't reach here.) Do this before the stop hook is
8357 run, so that it doesn't get to see the temporary dummy frame,
8358 which is not where we'll present the stop. */
8359 if (has_stack_frames ())
8361 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8363 /* Pop the empty frame that contains the stack dummy. This
8364 also restores inferior state prior to the call (struct
8365 infcall_suspend_state). */
8366 struct frame_info
*frame
= get_current_frame ();
8368 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8370 /* frame_pop calls reinit_frame_cache as the last thing it
8371 does which means there's now no selected frame. */
8374 select_frame (get_current_frame ());
8376 /* Set the current source location. */
8377 set_current_sal_from_frame (get_current_frame ());
8380 /* Look up the hook_stop and run it (CLI internally handles problem
8381 of stop_command's pre-hook not existing). */
8382 if (stop_command
!= NULL
)
8384 stop_context saved_context
;
8388 execute_cmd_pre_hook (stop_command
);
8390 catch (const gdb_exception
&ex
)
8392 exception_fprintf (gdb_stderr
, ex
,
8393 "Error while running hook_stop:\n");
8396 /* If the stop hook resumes the target, then there's no point in
8397 trying to notify about the previous stop; its context is
8398 gone. Likewise if the command switches thread or inferior --
8399 the observers would print a stop for the wrong
8401 if (saved_context
.changed ())
8405 /* Notify observers about the stop. This is where the interpreters
8406 print the stop event. */
8407 if (inferior_ptid
!= null_ptid
)
8408 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8411 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8413 annotate_stopped ();
8415 if (target_has_execution ())
8417 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8418 && last
.kind
!= TARGET_WAITKIND_EXITED
8419 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8420 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8421 Delete any breakpoint that is to be deleted at the next stop. */
8422 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8425 /* Try to get rid of automatically added inferiors that are no
8426 longer needed. Keeping those around slows down things linearly.
8427 Note that this never removes the current inferior. */
8434 signal_stop_state (int signo
)
8436 return signal_stop
[signo
];
8440 signal_print_state (int signo
)
8442 return signal_print
[signo
];
8446 signal_pass_state (int signo
)
8448 return signal_program
[signo
];
8452 signal_cache_update (int signo
)
8456 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8457 signal_cache_update (signo
);
8462 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8463 && signal_print
[signo
] == 0
8464 && signal_program
[signo
] == 1
8465 && signal_catch
[signo
] == 0);
8469 signal_stop_update (int signo
, int state
)
8471 int ret
= signal_stop
[signo
];
8473 signal_stop
[signo
] = state
;
8474 signal_cache_update (signo
);
8479 signal_print_update (int signo
, int state
)
8481 int ret
= signal_print
[signo
];
8483 signal_print
[signo
] = state
;
8484 signal_cache_update (signo
);
8489 signal_pass_update (int signo
, int state
)
8491 int ret
= signal_program
[signo
];
8493 signal_program
[signo
] = state
;
8494 signal_cache_update (signo
);
8498 /* Update the global 'signal_catch' from INFO and notify the
8502 signal_catch_update (const unsigned int *info
)
8506 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8507 signal_catch
[i
] = info
[i
] > 0;
8508 signal_cache_update (-1);
8509 target_pass_signals (signal_pass
);
8513 sig_print_header (void)
8515 printf_filtered (_("Signal Stop\tPrint\tPass "
8516 "to program\tDescription\n"));
8520 sig_print_info (enum gdb_signal oursig
)
8522 const char *name
= gdb_signal_to_name (oursig
);
8523 int name_padding
= 13 - strlen (name
);
8525 if (name_padding
<= 0)
8528 printf_filtered ("%s", name
);
8529 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8530 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8531 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8532 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8533 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8536 /* Specify how various signals in the inferior should be handled. */
8539 handle_command (const char *args
, int from_tty
)
8541 int digits
, wordlen
;
8542 int sigfirst
, siglast
;
8543 enum gdb_signal oursig
;
8548 error_no_arg (_("signal to handle"));
8551 /* Allocate and zero an array of flags for which signals to handle. */
8553 const size_t nsigs
= GDB_SIGNAL_LAST
;
8554 unsigned char sigs
[nsigs
] {};
8556 /* Break the command line up into args. */
8558 gdb_argv
built_argv (args
);
8560 /* Walk through the args, looking for signal oursigs, signal names, and
8561 actions. Signal numbers and signal names may be interspersed with
8562 actions, with the actions being performed for all signals cumulatively
8563 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8565 for (char *arg
: built_argv
)
8567 wordlen
= strlen (arg
);
8568 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8572 sigfirst
= siglast
= -1;
8574 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8576 /* Apply action to all signals except those used by the
8577 debugger. Silently skip those. */
8580 siglast
= nsigs
- 1;
8582 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8584 SET_SIGS (nsigs
, sigs
, signal_stop
);
8585 SET_SIGS (nsigs
, sigs
, signal_print
);
8587 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8589 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8591 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8593 SET_SIGS (nsigs
, sigs
, signal_print
);
8595 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8597 SET_SIGS (nsigs
, sigs
, signal_program
);
8599 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8601 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8603 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8605 SET_SIGS (nsigs
, sigs
, signal_program
);
8607 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8609 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8610 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8612 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8614 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8616 else if (digits
> 0)
8618 /* It is numeric. The numeric signal refers to our own
8619 internal signal numbering from target.h, not to host/target
8620 signal number. This is a feature; users really should be
8621 using symbolic names anyway, and the common ones like
8622 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8624 sigfirst
= siglast
= (int)
8625 gdb_signal_from_command (atoi (arg
));
8626 if (arg
[digits
] == '-')
8629 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8631 if (sigfirst
> siglast
)
8633 /* Bet he didn't figure we'd think of this case... */
8634 std::swap (sigfirst
, siglast
);
8639 oursig
= gdb_signal_from_name (arg
);
8640 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8642 sigfirst
= siglast
= (int) oursig
;
8646 /* Not a number and not a recognized flag word => complain. */
8647 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8651 /* If any signal numbers or symbol names were found, set flags for
8652 which signals to apply actions to. */
8654 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8656 switch ((enum gdb_signal
) signum
)
8658 case GDB_SIGNAL_TRAP
:
8659 case GDB_SIGNAL_INT
:
8660 if (!allsigs
&& !sigs
[signum
])
8662 if (query (_("%s is used by the debugger.\n\
8663 Are you sure you want to change it? "),
8664 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8669 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8673 case GDB_SIGNAL_DEFAULT
:
8674 case GDB_SIGNAL_UNKNOWN
:
8675 /* Make sure that "all" doesn't print these. */
8684 for (int signum
= 0; signum
< nsigs
; signum
++)
8687 signal_cache_update (-1);
8688 target_pass_signals (signal_pass
);
8689 target_program_signals (signal_program
);
8693 /* Show the results. */
8694 sig_print_header ();
8695 for (; signum
< nsigs
; signum
++)
8697 sig_print_info ((enum gdb_signal
) signum
);
8704 /* Complete the "handle" command. */
8707 handle_completer (struct cmd_list_element
*ignore
,
8708 completion_tracker
&tracker
,
8709 const char *text
, const char *word
)
8711 static const char * const keywords
[] =
8725 signal_completer (ignore
, tracker
, text
, word
);
8726 complete_on_enum (tracker
, keywords
, word
, word
);
8730 gdb_signal_from_command (int num
)
8732 if (num
>= 1 && num
<= 15)
8733 return (enum gdb_signal
) num
;
8734 error (_("Only signals 1-15 are valid as numeric signals.\n\
8735 Use \"info signals\" for a list of symbolic signals."));
8738 /* Print current contents of the tables set by the handle command.
8739 It is possible we should just be printing signals actually used
8740 by the current target (but for things to work right when switching
8741 targets, all signals should be in the signal tables). */
8744 info_signals_command (const char *signum_exp
, int from_tty
)
8746 enum gdb_signal oursig
;
8748 sig_print_header ();
8752 /* First see if this is a symbol name. */
8753 oursig
= gdb_signal_from_name (signum_exp
);
8754 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8756 /* No, try numeric. */
8758 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8760 sig_print_info (oursig
);
8764 printf_filtered ("\n");
8765 /* These ugly casts brought to you by the native VAX compiler. */
8766 for (oursig
= GDB_SIGNAL_FIRST
;
8767 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8768 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8772 if (oursig
!= GDB_SIGNAL_UNKNOWN
8773 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8774 sig_print_info (oursig
);
8777 printf_filtered (_("\nUse the \"handle\" command "
8778 "to change these tables.\n"));
8781 /* The $_siginfo convenience variable is a bit special. We don't know
8782 for sure the type of the value until we actually have a chance to
8783 fetch the data. The type can change depending on gdbarch, so it is
8784 also dependent on which thread you have selected.
8786 1. making $_siginfo be an internalvar that creates a new value on
8789 2. making the value of $_siginfo be an lval_computed value. */
8791 /* This function implements the lval_computed support for reading a
8795 siginfo_value_read (struct value
*v
)
8797 LONGEST transferred
;
8799 /* If we can access registers, so can we access $_siginfo. Likewise
8801 validate_registers_access ();
8804 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8806 value_contents_all_raw (v
),
8808 TYPE_LENGTH (value_type (v
)));
8810 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8811 error (_("Unable to read siginfo"));
8814 /* This function implements the lval_computed support for writing a
8818 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8820 LONGEST transferred
;
8822 /* If we can access registers, so can we access $_siginfo. Likewise
8824 validate_registers_access ();
8826 transferred
= target_write (current_top_target (),
8827 TARGET_OBJECT_SIGNAL_INFO
,
8829 value_contents_all_raw (fromval
),
8831 TYPE_LENGTH (value_type (fromval
)));
8833 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8834 error (_("Unable to write siginfo"));
8837 static const struct lval_funcs siginfo_value_funcs
=
8843 /* Return a new value with the correct type for the siginfo object of
8844 the current thread using architecture GDBARCH. Return a void value
8845 if there's no object available. */
8847 static struct value
*
8848 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8851 if (target_has_stack ()
8852 && inferior_ptid
!= null_ptid
8853 && gdbarch_get_siginfo_type_p (gdbarch
))
8855 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8857 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8860 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8864 /* infcall_suspend_state contains state about the program itself like its
8865 registers and any signal it received when it last stopped.
8866 This state must be restored regardless of how the inferior function call
8867 ends (either successfully, or after it hits a breakpoint or signal)
8868 if the program is to properly continue where it left off. */
8870 class infcall_suspend_state
8873 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8874 once the inferior function call has finished. */
8875 infcall_suspend_state (struct gdbarch
*gdbarch
,
8876 const struct thread_info
*tp
,
8877 struct regcache
*regcache
)
8878 : m_thread_suspend (tp
->suspend
),
8879 m_registers (new readonly_detached_regcache (*regcache
))
8881 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8883 if (gdbarch_get_siginfo_type_p (gdbarch
))
8885 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8886 size_t len
= TYPE_LENGTH (type
);
8888 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8890 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8891 siginfo_data
.get (), 0, len
) != len
)
8893 /* Errors ignored. */
8894 siginfo_data
.reset (nullptr);
8900 m_siginfo_gdbarch
= gdbarch
;
8901 m_siginfo_data
= std::move (siginfo_data
);
8905 /* Return a pointer to the stored register state. */
8907 readonly_detached_regcache
*registers () const
8909 return m_registers
.get ();
8912 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8914 void restore (struct gdbarch
*gdbarch
,
8915 struct thread_info
*tp
,
8916 struct regcache
*regcache
) const
8918 tp
->suspend
= m_thread_suspend
;
8920 if (m_siginfo_gdbarch
== gdbarch
)
8922 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8924 /* Errors ignored. */
8925 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8926 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8929 /* The inferior can be gone if the user types "print exit(0)"
8930 (and perhaps other times). */
8931 if (target_has_execution ())
8932 /* NB: The register write goes through to the target. */
8933 regcache
->restore (registers ());
8937 /* How the current thread stopped before the inferior function call was
8939 struct thread_suspend_state m_thread_suspend
;
8941 /* The registers before the inferior function call was executed. */
8942 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8944 /* Format of SIGINFO_DATA or NULL if it is not present. */
8945 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8947 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8948 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8949 content would be invalid. */
8950 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8953 infcall_suspend_state_up
8954 save_infcall_suspend_state ()
8956 struct thread_info
*tp
= inferior_thread ();
8957 struct regcache
*regcache
= get_current_regcache ();
8958 struct gdbarch
*gdbarch
= regcache
->arch ();
8960 infcall_suspend_state_up inf_state
8961 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8963 /* Having saved the current state, adjust the thread state, discarding
8964 any stop signal information. The stop signal is not useful when
8965 starting an inferior function call, and run_inferior_call will not use
8966 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8967 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8972 /* Restore inferior session state to INF_STATE. */
8975 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8977 struct thread_info
*tp
= inferior_thread ();
8978 struct regcache
*regcache
= get_current_regcache ();
8979 struct gdbarch
*gdbarch
= regcache
->arch ();
8981 inf_state
->restore (gdbarch
, tp
, regcache
);
8982 discard_infcall_suspend_state (inf_state
);
8986 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8991 readonly_detached_regcache
*
8992 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8994 return inf_state
->registers ();
8997 /* infcall_control_state contains state regarding gdb's control of the
8998 inferior itself like stepping control. It also contains session state like
8999 the user's currently selected frame. */
9001 struct infcall_control_state
9003 struct thread_control_state thread_control
;
9004 struct inferior_control_state inferior_control
;
9007 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9008 int stopped_by_random_signal
= 0;
9010 /* ID if the selected frame when the inferior function call was made. */
9011 struct frame_id selected_frame_id
{};
9014 /* Save all of the information associated with the inferior<==>gdb
9017 infcall_control_state_up
9018 save_infcall_control_state ()
9020 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9021 struct thread_info
*tp
= inferior_thread ();
9022 struct inferior
*inf
= current_inferior ();
9024 inf_status
->thread_control
= tp
->control
;
9025 inf_status
->inferior_control
= inf
->control
;
9027 tp
->control
.step_resume_breakpoint
= NULL
;
9028 tp
->control
.exception_resume_breakpoint
= NULL
;
9030 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9031 chain. If caller's caller is walking the chain, they'll be happier if we
9032 hand them back the original chain when restore_infcall_control_state is
9034 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9037 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9038 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9040 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9046 restore_selected_frame (const frame_id
&fid
)
9048 frame_info
*frame
= frame_find_by_id (fid
);
9050 /* If inf_status->selected_frame_id is NULL, there was no previously
9054 warning (_("Unable to restore previously selected frame."));
9058 select_frame (frame
);
9061 /* Restore inferior session state to INF_STATUS. */
9064 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9066 struct thread_info
*tp
= inferior_thread ();
9067 struct inferior
*inf
= current_inferior ();
9069 if (tp
->control
.step_resume_breakpoint
)
9070 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9072 if (tp
->control
.exception_resume_breakpoint
)
9073 tp
->control
.exception_resume_breakpoint
->disposition
9074 = disp_del_at_next_stop
;
9076 /* Handle the bpstat_copy of the chain. */
9077 bpstat_clear (&tp
->control
.stop_bpstat
);
9079 tp
->control
= inf_status
->thread_control
;
9080 inf
->control
= inf_status
->inferior_control
;
9083 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9084 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9086 if (target_has_stack ())
9088 /* The point of the try/catch is that if the stack is clobbered,
9089 walking the stack might encounter a garbage pointer and
9090 error() trying to dereference it. */
9093 restore_selected_frame (inf_status
->selected_frame_id
);
9095 catch (const gdb_exception_error
&ex
)
9097 exception_fprintf (gdb_stderr
, ex
,
9098 "Unable to restore previously selected frame:\n");
9099 /* Error in restoring the selected frame. Select the
9101 select_frame (get_current_frame ());
9109 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9111 if (inf_status
->thread_control
.step_resume_breakpoint
)
9112 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9113 = disp_del_at_next_stop
;
9115 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9116 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9117 = disp_del_at_next_stop
;
9119 /* See save_infcall_control_state for info on stop_bpstat. */
9120 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9128 clear_exit_convenience_vars (void)
9130 clear_internalvar (lookup_internalvar ("_exitsignal"));
9131 clear_internalvar (lookup_internalvar ("_exitcode"));
9135 /* User interface for reverse debugging:
9136 Set exec-direction / show exec-direction commands
9137 (returns error unless target implements to_set_exec_direction method). */
9139 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9140 static const char exec_forward
[] = "forward";
9141 static const char exec_reverse
[] = "reverse";
9142 static const char *exec_direction
= exec_forward
;
9143 static const char *const exec_direction_names
[] = {
9150 set_exec_direction_func (const char *args
, int from_tty
,
9151 struct cmd_list_element
*cmd
)
9153 if (target_can_execute_reverse ())
9155 if (!strcmp (exec_direction
, exec_forward
))
9156 execution_direction
= EXEC_FORWARD
;
9157 else if (!strcmp (exec_direction
, exec_reverse
))
9158 execution_direction
= EXEC_REVERSE
;
9162 exec_direction
= exec_forward
;
9163 error (_("Target does not support this operation."));
9168 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9169 struct cmd_list_element
*cmd
, const char *value
)
9171 switch (execution_direction
) {
9173 fprintf_filtered (out
, _("Forward.\n"));
9176 fprintf_filtered (out
, _("Reverse.\n"));
9179 internal_error (__FILE__
, __LINE__
,
9180 _("bogus execution_direction value: %d"),
9181 (int) execution_direction
);
9186 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9187 struct cmd_list_element
*c
, const char *value
)
9189 fprintf_filtered (file
, _("Resuming the execution of threads "
9190 "of all processes is %s.\n"), value
);
9193 /* Implementation of `siginfo' variable. */
9195 static const struct internalvar_funcs siginfo_funcs
=
9202 /* Callback for infrun's target events source. This is marked when a
9203 thread has a pending status to process. */
9206 infrun_async_inferior_event_handler (gdb_client_data data
)
9208 inferior_event_handler (INF_REG_EVENT
);
9215 /* Verify that when two threads with the same ptid exist (from two different
9216 targets) and one of them changes ptid, we only update inferior_ptid if
9217 it is appropriate. */
9220 infrun_thread_ptid_changed ()
9222 gdbarch
*arch
= current_inferior ()->gdbarch
;
9224 /* The thread which inferior_ptid represents changes ptid. */
9226 scoped_restore_current_pspace_and_thread restore
;
9228 scoped_mock_context
<test_target_ops
> target1 (arch
);
9229 scoped_mock_context
<test_target_ops
> target2 (arch
);
9230 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9232 ptid_t
old_ptid (111, 222);
9233 ptid_t
new_ptid (111, 333);
9235 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9236 target1
.mock_thread
.ptid
= old_ptid
;
9237 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9238 target2
.mock_thread
.ptid
= old_ptid
;
9240 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9241 set_current_inferior (&target1
.mock_inferior
);
9243 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9245 gdb_assert (inferior_ptid
== new_ptid
);
9248 /* A thread with the same ptid as inferior_ptid, but from another target,
9251 scoped_restore_current_pspace_and_thread restore
;
9253 scoped_mock_context
<test_target_ops
> target1 (arch
);
9254 scoped_mock_context
<test_target_ops
> target2 (arch
);
9255 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9257 ptid_t
old_ptid (111, 222);
9258 ptid_t
new_ptid (111, 333);
9260 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9261 target1
.mock_thread
.ptid
= old_ptid
;
9262 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9263 target2
.mock_thread
.ptid
= old_ptid
;
9265 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9266 set_current_inferior (&target2
.mock_inferior
);
9268 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9270 gdb_assert (inferior_ptid
== old_ptid
);
9274 } /* namespace selftests */
9276 #endif /* GDB_SELF_TEST */
9278 void _initialize_infrun ();
9280 _initialize_infrun ()
9282 struct cmd_list_element
*c
;
9284 /* Register extra event sources in the event loop. */
9285 infrun_async_inferior_event_token
9286 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9289 add_info ("signals", info_signals_command
, _("\
9290 What debugger does when program gets various signals.\n\
9291 Specify a signal as argument to print info on that signal only."));
9292 add_info_alias ("handle", "signals", 0);
9294 c
= add_com ("handle", class_run
, handle_command
, _("\
9295 Specify how to handle signals.\n\
9296 Usage: handle SIGNAL [ACTIONS]\n\
9297 Args are signals and actions to apply to those signals.\n\
9298 If no actions are specified, the current settings for the specified signals\n\
9299 will be displayed instead.\n\
9301 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9302 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9303 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9304 The special arg \"all\" is recognized to mean all signals except those\n\
9305 used by the debugger, typically SIGTRAP and SIGINT.\n\
9307 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9308 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9309 Stop means reenter debugger if this signal happens (implies print).\n\
9310 Print means print a message if this signal happens.\n\
9311 Pass means let program see this signal; otherwise program doesn't know.\n\
9312 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9313 Pass and Stop may be combined.\n\
9315 Multiple signals may be specified. Signal numbers and signal names\n\
9316 may be interspersed with actions, with the actions being performed for\n\
9317 all signals cumulatively specified."));
9318 set_cmd_completer (c
, handle_completer
);
9321 stop_command
= add_cmd ("stop", class_obscure
,
9322 not_just_help_class_command
, _("\
9323 There is no `stop' command, but you can set a hook on `stop'.\n\
9324 This allows you to set a list of commands to be run each time execution\n\
9325 of the program stops."), &cmdlist
);
9327 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9328 Set inferior debugging."), _("\
9329 Show inferior debugging."), _("\
9330 When non-zero, inferior specific debugging is enabled."),
9333 &setdebuglist
, &showdebuglist
);
9335 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9336 &debug_displaced
, _("\
9337 Set displaced stepping debugging."), _("\
9338 Show displaced stepping debugging."), _("\
9339 When non-zero, displaced stepping specific debugging is enabled."),
9341 show_debug_displaced
,
9342 &setdebuglist
, &showdebuglist
);
9344 add_setshow_boolean_cmd ("non-stop", no_class
,
9346 Set whether gdb controls the inferior in non-stop mode."), _("\
9347 Show whether gdb controls the inferior in non-stop mode."), _("\
9348 When debugging a multi-threaded program and this setting is\n\
9349 off (the default, also called all-stop mode), when one thread stops\n\
9350 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9351 all other threads in the program while you interact with the thread of\n\
9352 interest. When you continue or step a thread, you can allow the other\n\
9353 threads to run, or have them remain stopped, but while you inspect any\n\
9354 thread's state, all threads stop.\n\
9356 In non-stop mode, when one thread stops, other threads can continue\n\
9357 to run freely. You'll be able to step each thread independently,\n\
9358 leave it stopped or free to run as needed."),
9364 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9367 signal_print
[i
] = 1;
9368 signal_program
[i
] = 1;
9369 signal_catch
[i
] = 0;
9372 /* Signals caused by debugger's own actions should not be given to
9373 the program afterwards.
9375 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9376 explicitly specifies that it should be delivered to the target
9377 program. Typically, that would occur when a user is debugging a
9378 target monitor on a simulator: the target monitor sets a
9379 breakpoint; the simulator encounters this breakpoint and halts
9380 the simulation handing control to GDB; GDB, noting that the stop
9381 address doesn't map to any known breakpoint, returns control back
9382 to the simulator; the simulator then delivers the hardware
9383 equivalent of a GDB_SIGNAL_TRAP to the program being
9385 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9386 signal_program
[GDB_SIGNAL_INT
] = 0;
9388 /* Signals that are not errors should not normally enter the debugger. */
9389 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9390 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9391 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9392 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9393 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9394 signal_print
[GDB_SIGNAL_PROF
] = 0;
9395 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9396 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9397 signal_stop
[GDB_SIGNAL_IO
] = 0;
9398 signal_print
[GDB_SIGNAL_IO
] = 0;
9399 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9400 signal_print
[GDB_SIGNAL_POLL
] = 0;
9401 signal_stop
[GDB_SIGNAL_URG
] = 0;
9402 signal_print
[GDB_SIGNAL_URG
] = 0;
9403 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9404 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9405 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9406 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9408 /* These signals are used internally by user-level thread
9409 implementations. (See signal(5) on Solaris.) Like the above
9410 signals, a healthy program receives and handles them as part of
9411 its normal operation. */
9412 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9413 signal_print
[GDB_SIGNAL_LWP
] = 0;
9414 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9415 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9416 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9417 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9418 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9419 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9421 /* Update cached state. */
9422 signal_cache_update (-1);
9424 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9425 &stop_on_solib_events
, _("\
9426 Set stopping for shared library events."), _("\
9427 Show stopping for shared library events."), _("\
9428 If nonzero, gdb will give control to the user when the dynamic linker\n\
9429 notifies gdb of shared library events. The most common event of interest\n\
9430 to the user would be loading/unloading of a new library."),
9431 set_stop_on_solib_events
,
9432 show_stop_on_solib_events
,
9433 &setlist
, &showlist
);
9435 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9436 follow_fork_mode_kind_names
,
9437 &follow_fork_mode_string
, _("\
9438 Set debugger response to a program call of fork or vfork."), _("\
9439 Show debugger response to a program call of fork or vfork."), _("\
9440 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9441 parent - the original process is debugged after a fork\n\
9442 child - the new process is debugged after a fork\n\
9443 The unfollowed process will continue to run.\n\
9444 By default, the debugger will follow the parent process."),
9446 show_follow_fork_mode_string
,
9447 &setlist
, &showlist
);
9449 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9450 follow_exec_mode_names
,
9451 &follow_exec_mode_string
, _("\
9452 Set debugger response to a program call of exec."), _("\
9453 Show debugger response to a program call of exec."), _("\
9454 An exec call replaces the program image of a process.\n\
9456 follow-exec-mode can be:\n\
9458 new - the debugger creates a new inferior and rebinds the process\n\
9459 to this new inferior. The program the process was running before\n\
9460 the exec call can be restarted afterwards by restarting the original\n\
9463 same - the debugger keeps the process bound to the same inferior.\n\
9464 The new executable image replaces the previous executable loaded in\n\
9465 the inferior. Restarting the inferior after the exec call restarts\n\
9466 the executable the process was running after the exec call.\n\
9468 By default, the debugger will use the same inferior."),
9470 show_follow_exec_mode_string
,
9471 &setlist
, &showlist
);
9473 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9474 scheduler_enums
, &scheduler_mode
, _("\
9475 Set mode for locking scheduler during execution."), _("\
9476 Show mode for locking scheduler during execution."), _("\
9477 off == no locking (threads may preempt at any time)\n\
9478 on == full locking (no thread except the current thread may run)\n\
9479 This applies to both normal execution and replay mode.\n\
9480 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9481 In this mode, other threads may run during other commands.\n\
9482 This applies to both normal execution and replay mode.\n\
9483 replay == scheduler locked in replay mode and unlocked during normal execution."),
9484 set_schedlock_func
, /* traps on target vector */
9485 show_scheduler_mode
,
9486 &setlist
, &showlist
);
9488 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9489 Set mode for resuming threads of all processes."), _("\
9490 Show mode for resuming threads of all processes."), _("\
9491 When on, execution commands (such as 'continue' or 'next') resume all\n\
9492 threads of all processes. When off (which is the default), execution\n\
9493 commands only resume the threads of the current process. The set of\n\
9494 threads that are resumed is further refined by the scheduler-locking\n\
9495 mode (see help set scheduler-locking)."),
9497 show_schedule_multiple
,
9498 &setlist
, &showlist
);
9500 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9501 Set mode of the step operation."), _("\
9502 Show mode of the step operation."), _("\
9503 When set, doing a step over a function without debug line information\n\
9504 will stop at the first instruction of that function. Otherwise, the\n\
9505 function is skipped and the step command stops at a different source line."),
9507 show_step_stop_if_no_debug
,
9508 &setlist
, &showlist
);
9510 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9511 &can_use_displaced_stepping
, _("\
9512 Set debugger's willingness to use displaced stepping."), _("\
9513 Show debugger's willingness to use displaced stepping."), _("\
9514 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9515 supported by the target architecture. If off, gdb will not use displaced\n\
9516 stepping to step over breakpoints, even if such is supported by the target\n\
9517 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9518 if the target architecture supports it and non-stop mode is active, but will not\n\
9519 use it in all-stop mode (see help set non-stop)."),
9521 show_can_use_displaced_stepping
,
9522 &setlist
, &showlist
);
9524 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9525 &exec_direction
, _("Set direction of execution.\n\
9526 Options are 'forward' or 'reverse'."),
9527 _("Show direction of execution (forward/reverse)."),
9528 _("Tells gdb whether to execute forward or backward."),
9529 set_exec_direction_func
, show_exec_direction_func
,
9530 &setlist
, &showlist
);
9532 /* Set/show detach-on-fork: user-settable mode. */
9534 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9535 Set whether gdb will detach the child of a fork."), _("\
9536 Show whether gdb will detach the child of a fork."), _("\
9537 Tells gdb whether to detach the child of a fork."),
9538 NULL
, NULL
, &setlist
, &showlist
);
9540 /* Set/show disable address space randomization mode. */
9542 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9543 &disable_randomization
, _("\
9544 Set disabling of debuggee's virtual address space randomization."), _("\
9545 Show disabling of debuggee's virtual address space randomization."), _("\
9546 When this mode is on (which is the default), randomization of the virtual\n\
9547 address space is disabled. Standalone programs run with the randomization\n\
9548 enabled by default on some platforms."),
9549 &set_disable_randomization
,
9550 &show_disable_randomization
,
9551 &setlist
, &showlist
);
9553 /* ptid initializations */
9554 inferior_ptid
= null_ptid
;
9555 target_last_wait_ptid
= minus_one_ptid
;
9557 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9558 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9559 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9560 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9562 /* Explicitly create without lookup, since that tries to create a
9563 value with a void typed value, and when we get here, gdbarch
9564 isn't initialized yet. At this point, we're quite sure there
9565 isn't another convenience variable of the same name. */
9566 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9568 add_setshow_boolean_cmd ("observer", no_class
,
9569 &observer_mode_1
, _("\
9570 Set whether gdb controls the inferior in observer mode."), _("\
9571 Show whether gdb controls the inferior in observer mode."), _("\
9572 In observer mode, GDB can get data from the inferior, but not\n\
9573 affect its execution. Registers and memory may not be changed,\n\
9574 breakpoints may not be set, and the program cannot be interrupted\n\
9582 selftests::register_test ("infrun_thread_ptid_changed",
9583 selftests::infrun_thread_ptid_changed
);