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 ();
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 represented by PTID is doing a displaced
1507 displaced_step_in_progress_thread (thread_info
*thread
)
1509 gdb_assert (thread
!= NULL
);
1511 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1514 /* Return true if process PID has a thread doing a displaced step. */
1517 displaced_step_in_progress (inferior
*inf
)
1519 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1522 /* If inferior is in displaced stepping, and ADDR equals to starting address
1523 of copy area, return corresponding displaced_step_closure. Otherwise,
1526 struct displaced_step_closure
*
1527 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1529 displaced_step_inferior_state
*displaced
1530 = get_displaced_stepping_state (current_inferior ());
1532 /* If checking the mode of displaced instruction in copy area. */
1533 if (displaced
->step_thread
!= nullptr
1534 && displaced
->step_copy
== addr
)
1535 return displaced
->step_closure
.get ();
1541 infrun_inferior_exit (struct inferior
*inf
)
1543 inf
->displaced_step_state
.reset ();
1546 /* If ON, and the architecture supports it, GDB will use displaced
1547 stepping to step over breakpoints. If OFF, or if the architecture
1548 doesn't support it, GDB will instead use the traditional
1549 hold-and-step approach. If AUTO (which is the default), GDB will
1550 decide which technique to use to step over breakpoints depending on
1551 whether the target works in a non-stop way (see use_displaced_stepping). */
1553 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1556 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1557 struct cmd_list_element
*c
,
1560 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1561 fprintf_filtered (file
,
1562 _("Debugger's willingness to use displaced stepping "
1563 "to step over breakpoints is %s (currently %s).\n"),
1564 value
, target_is_non_stop_p () ? "on" : "off");
1566 fprintf_filtered (file
,
1567 _("Debugger's willingness to use displaced stepping "
1568 "to step over breakpoints is %s.\n"), value
);
1571 /* Return true if the gdbarch implements the required methods to use
1572 displaced stepping. */
1575 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1577 /* Only check for the presence of step_copy_insn. Other required methods
1578 are checked by the gdbarch validation. */
1579 return gdbarch_displaced_step_copy_insn_p (arch
);
1582 /* Return non-zero if displaced stepping can/should be used to step
1583 over breakpoints of thread TP. */
1586 use_displaced_stepping (thread_info
*tp
)
1588 /* If the user disabled it explicitly, don't use displaced stepping. */
1589 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1592 /* If "auto", only use displaced stepping if the target operates in a non-stop
1594 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1595 && !target_is_non_stop_p ())
1598 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1600 /* If the architecture doesn't implement displaced stepping, don't use
1602 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1605 /* If recording, don't use displaced stepping. */
1606 if (find_record_target () != nullptr)
1609 displaced_step_inferior_state
*displaced_state
1610 = get_displaced_stepping_state (tp
->inf
);
1612 /* If displaced stepping failed before for this inferior, don't bother trying
1614 if (displaced_state
->failed_before
)
1620 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1623 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1625 displaced
->reset ();
1628 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1629 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1631 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1633 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1635 displaced_step_dump_bytes (struct ui_file
*file
,
1636 const gdb_byte
*buf
,
1641 for (i
= 0; i
< len
; i
++)
1642 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1643 fputs_unfiltered ("\n", file
);
1646 /* Prepare to single-step, using displaced stepping.
1648 Note that we cannot use displaced stepping when we have a signal to
1649 deliver. If we have a signal to deliver and an instruction to step
1650 over, then after the step, there will be no indication from the
1651 target whether the thread entered a signal handler or ignored the
1652 signal and stepped over the instruction successfully --- both cases
1653 result in a simple SIGTRAP. In the first case we mustn't do a
1654 fixup, and in the second case we must --- but we can't tell which.
1655 Comments in the code for 'random signals' in handle_inferior_event
1656 explain how we handle this case instead.
1658 Returns 1 if preparing was successful -- this thread is going to be
1659 stepped now; 0 if displaced stepping this thread got queued; or -1
1660 if this instruction can't be displaced stepped. */
1663 displaced_step_prepare_throw (thread_info
*tp
)
1665 regcache
*regcache
= get_thread_regcache (tp
);
1666 struct gdbarch
*gdbarch
= regcache
->arch ();
1667 const address_space
*aspace
= regcache
->aspace ();
1668 CORE_ADDR original
, copy
;
1672 /* We should never reach this function if the architecture does not
1673 support displaced stepping. */
1674 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1676 /* Nor if the thread isn't meant to step over a breakpoint. */
1677 gdb_assert (tp
->control
.trap_expected
);
1679 /* Disable range stepping while executing in the scratch pad. We
1680 want a single-step even if executing the displaced instruction in
1681 the scratch buffer lands within the stepping range (e.g., a
1683 tp
->control
.may_range_step
= 0;
1685 /* We have to displaced step one thread at a time, as we only have
1686 access to a single scratch space per inferior. */
1688 displaced_step_inferior_state
*displaced
1689 = get_displaced_stepping_state (tp
->inf
);
1691 if (displaced
->step_thread
!= nullptr)
1693 /* Already waiting for a displaced step to finish. Defer this
1694 request and place in queue. */
1696 if (debug_displaced
)
1697 fprintf_unfiltered (gdb_stdlog
,
1698 "displaced: deferring step of %s\n",
1699 target_pid_to_str (tp
->ptid
).c_str ());
1701 thread_step_over_chain_enqueue (tp
);
1706 if (debug_displaced
)
1707 fprintf_unfiltered (gdb_stdlog
,
1708 "displaced: stepping %s now\n",
1709 target_pid_to_str (tp
->ptid
).c_str ());
1712 displaced_step_reset (displaced
);
1714 scoped_restore_current_thread restore_thread
;
1716 switch_to_thread (tp
);
1718 original
= regcache_read_pc (regcache
);
1720 copy
= gdbarch_displaced_step_location (gdbarch
);
1721 len
= gdbarch_max_insn_length (gdbarch
);
1723 if (breakpoint_in_range_p (aspace
, copy
, len
))
1725 /* There's a breakpoint set in the scratch pad location range
1726 (which is usually around the entry point). We'd either
1727 install it before resuming, which would overwrite/corrupt the
1728 scratch pad, or if it was already inserted, this displaced
1729 step would overwrite it. The latter is OK in the sense that
1730 we already assume that no thread is going to execute the code
1731 in the scratch pad range (after initial startup) anyway, but
1732 the former is unacceptable. Simply punt and fallback to
1733 stepping over this breakpoint in-line. */
1734 if (debug_displaced
)
1736 fprintf_unfiltered (gdb_stdlog
,
1737 "displaced: breakpoint set in scratch pad. "
1738 "Stepping over breakpoint in-line instead.\n");
1744 /* Save the original contents of the copy area. */
1745 displaced
->step_saved_copy
.resize (len
);
1746 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1748 throw_error (MEMORY_ERROR
,
1749 _("Error accessing memory address %s (%s) for "
1750 "displaced-stepping scratch space."),
1751 paddress (gdbarch
, copy
), safe_strerror (status
));
1752 if (debug_displaced
)
1754 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1755 paddress (gdbarch
, copy
));
1756 displaced_step_dump_bytes (gdb_stdlog
,
1757 displaced
->step_saved_copy
.data (),
1761 displaced
->step_closure
1762 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1763 if (displaced
->step_closure
== NULL
)
1765 /* The architecture doesn't know how or want to displaced step
1766 this instruction or instruction sequence. Fallback to
1767 stepping over the breakpoint in-line. */
1771 /* Save the information we need to fix things up if the step
1773 displaced
->step_thread
= tp
;
1774 displaced
->step_gdbarch
= gdbarch
;
1775 displaced
->step_original
= original
;
1776 displaced
->step_copy
= copy
;
1779 displaced_step_reset_cleanup
cleanup (displaced
);
1781 /* Resume execution at the copy. */
1782 regcache_write_pc (regcache
, copy
);
1787 if (debug_displaced
)
1788 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1789 paddress (gdbarch
, copy
));
1794 /* Wrapper for displaced_step_prepare_throw that disabled further
1795 attempts at displaced stepping if we get a memory error. */
1798 displaced_step_prepare (thread_info
*thread
)
1804 prepared
= displaced_step_prepare_throw (thread
);
1806 catch (const gdb_exception_error
&ex
)
1808 struct displaced_step_inferior_state
*displaced_state
;
1810 if (ex
.error
!= MEMORY_ERROR
1811 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1814 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1817 /* Be verbose if "set displaced-stepping" is "on", silent if
1819 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1821 warning (_("disabling displaced stepping: %s"),
1825 /* Disable further displaced stepping attempts. */
1827 = get_displaced_stepping_state (thread
->inf
);
1828 displaced_state
->failed_before
= 1;
1835 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1836 const gdb_byte
*myaddr
, int len
)
1838 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1840 inferior_ptid
= ptid
;
1841 write_memory (memaddr
, myaddr
, len
);
1844 /* Restore the contents of the copy area for thread PTID. */
1847 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1850 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1852 write_memory_ptid (ptid
, displaced
->step_copy
,
1853 displaced
->step_saved_copy
.data (), len
);
1854 if (debug_displaced
)
1855 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1856 target_pid_to_str (ptid
).c_str (),
1857 paddress (displaced
->step_gdbarch
,
1858 displaced
->step_copy
));
1861 /* If we displaced stepped an instruction successfully, adjust
1862 registers and memory to yield the same effect the instruction would
1863 have had if we had executed it at its original address, and return
1864 1. If the instruction didn't complete, relocate the PC and return
1865 -1. If the thread wasn't displaced stepping, return 0. */
1868 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1870 struct displaced_step_inferior_state
*displaced
1871 = get_displaced_stepping_state (event_thread
->inf
);
1874 /* Was this event for the thread we displaced? */
1875 if (displaced
->step_thread
!= event_thread
)
1878 /* Fixup may need to read memory/registers. Switch to the thread
1879 that we're fixing up. Also, target_stopped_by_watchpoint checks
1880 the current thread, and displaced_step_restore performs ptid-dependent
1881 memory accesses using current_inferior() and current_top_target(). */
1882 switch_to_thread (event_thread
);
1884 displaced_step_reset_cleanup
cleanup (displaced
);
1886 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1888 /* Did the instruction complete successfully? */
1889 if (signal
== GDB_SIGNAL_TRAP
1890 && !(target_stopped_by_watchpoint ()
1891 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1892 || target_have_steppable_watchpoint ())))
1894 /* Fix up the resulting state. */
1895 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1896 displaced
->step_closure
.get (),
1897 displaced
->step_original
,
1898 displaced
->step_copy
,
1899 get_thread_regcache (displaced
->step_thread
));
1904 /* Since the instruction didn't complete, all we can do is
1906 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1907 CORE_ADDR pc
= regcache_read_pc (regcache
);
1909 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1910 regcache_write_pc (regcache
, pc
);
1917 /* Data to be passed around while handling an event. This data is
1918 discarded between events. */
1919 struct execution_control_state
1921 process_stratum_target
*target
;
1923 /* The thread that got the event, if this was a thread event; NULL
1925 struct thread_info
*event_thread
;
1927 struct target_waitstatus ws
;
1928 int stop_func_filled_in
;
1929 CORE_ADDR stop_func_start
;
1930 CORE_ADDR stop_func_end
;
1931 const char *stop_func_name
;
1934 /* True if the event thread hit the single-step breakpoint of
1935 another thread. Thus the event doesn't cause a stop, the thread
1936 needs to be single-stepped past the single-step breakpoint before
1937 we can switch back to the original stepping thread. */
1938 int hit_singlestep_breakpoint
;
1941 /* Clear ECS and set it to point at TP. */
1944 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1946 memset (ecs
, 0, sizeof (*ecs
));
1947 ecs
->event_thread
= tp
;
1948 ecs
->ptid
= tp
->ptid
;
1951 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1952 static void prepare_to_wait (struct execution_control_state
*ecs
);
1953 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1954 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1956 /* Are there any pending step-over requests? If so, run all we can
1957 now and return true. Otherwise, return false. */
1960 start_step_over (void)
1962 struct thread_info
*tp
, *next
;
1964 /* Don't start a new step-over if we already have an in-line
1965 step-over operation ongoing. */
1966 if (step_over_info_valid_p ())
1969 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1971 struct execution_control_state ecss
;
1972 struct execution_control_state
*ecs
= &ecss
;
1973 step_over_what step_what
;
1974 int must_be_in_line
;
1976 gdb_assert (!tp
->stop_requested
);
1978 next
= thread_step_over_chain_next (tp
);
1980 /* If this inferior already has a displaced step in process,
1981 don't start a new one. */
1982 if (displaced_step_in_progress (tp
->inf
))
1985 step_what
= thread_still_needs_step_over (tp
);
1986 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1987 || ((step_what
& STEP_OVER_BREAKPOINT
)
1988 && !use_displaced_stepping (tp
)));
1990 /* We currently stop all threads of all processes to step-over
1991 in-line. If we need to start a new in-line step-over, let
1992 any pending displaced steps finish first. */
1993 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1996 thread_step_over_chain_remove (tp
);
1998 if (step_over_queue_head
== NULL
)
1999 infrun_debug_printf ("step-over queue now empty");
2001 if (tp
->control
.trap_expected
2005 internal_error (__FILE__
, __LINE__
,
2006 "[%s] has inconsistent state: "
2007 "trap_expected=%d, resumed=%d, executing=%d\n",
2008 target_pid_to_str (tp
->ptid
).c_str (),
2009 tp
->control
.trap_expected
,
2014 infrun_debug_printf ("resuming [%s] for step-over",
2015 target_pid_to_str (tp
->ptid
).c_str ());
2017 /* keep_going_pass_signal skips the step-over if the breakpoint
2018 is no longer inserted. In all-stop, we want to keep looking
2019 for a thread that needs a step-over instead of resuming TP,
2020 because we wouldn't be able to resume anything else until the
2021 target stops again. In non-stop, the resume always resumes
2022 only TP, so it's OK to let the thread resume freely. */
2023 if (!target_is_non_stop_p () && !step_what
)
2026 switch_to_thread (tp
);
2027 reset_ecs (ecs
, tp
);
2028 keep_going_pass_signal (ecs
);
2030 if (!ecs
->wait_some_more
)
2031 error (_("Command aborted."));
2033 gdb_assert (tp
->resumed
);
2035 /* If we started a new in-line step-over, we're done. */
2036 if (step_over_info_valid_p ())
2038 gdb_assert (tp
->control
.trap_expected
);
2042 if (!target_is_non_stop_p ())
2044 /* On all-stop, shouldn't have resumed unless we needed a
2046 gdb_assert (tp
->control
.trap_expected
2047 || tp
->step_after_step_resume_breakpoint
);
2049 /* With remote targets (at least), in all-stop, we can't
2050 issue any further remote commands until the program stops
2055 /* Either the thread no longer needed a step-over, or a new
2056 displaced stepping sequence started. Even in the latter
2057 case, continue looking. Maybe we can also start another
2058 displaced step on a thread of other process. */
2064 /* Update global variables holding ptids to hold NEW_PTID if they were
2065 holding OLD_PTID. */
2067 infrun_thread_ptid_changed (process_stratum_target
*target
,
2068 ptid_t old_ptid
, ptid_t new_ptid
)
2070 if (inferior_ptid
== old_ptid
2071 && current_inferior ()->process_target () == target
)
2072 inferior_ptid
= new_ptid
;
2077 static const char schedlock_off
[] = "off";
2078 static const char schedlock_on
[] = "on";
2079 static const char schedlock_step
[] = "step";
2080 static const char schedlock_replay
[] = "replay";
2081 static const char *const scheduler_enums
[] = {
2088 static const char *scheduler_mode
= schedlock_replay
;
2090 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2091 struct cmd_list_element
*c
, const char *value
)
2093 fprintf_filtered (file
,
2094 _("Mode for locking scheduler "
2095 "during execution is \"%s\".\n"),
2100 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2102 if (!target_can_lock_scheduler ())
2104 scheduler_mode
= schedlock_off
;
2105 error (_("Target '%s' cannot support this command."), target_shortname
);
2109 /* True if execution commands resume all threads of all processes by
2110 default; otherwise, resume only threads of the current inferior
2112 bool sched_multi
= false;
2114 /* Try to setup for software single stepping over the specified location.
2115 Return true if target_resume() should use hardware single step.
2117 GDBARCH the current gdbarch.
2118 PC the location to step over. */
2121 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2123 bool hw_step
= true;
2125 if (execution_direction
== EXEC_FORWARD
2126 && gdbarch_software_single_step_p (gdbarch
))
2127 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2135 user_visible_resume_ptid (int step
)
2141 /* With non-stop mode on, threads are always handled
2143 resume_ptid
= inferior_ptid
;
2145 else if ((scheduler_mode
== schedlock_on
)
2146 || (scheduler_mode
== schedlock_step
&& step
))
2148 /* User-settable 'scheduler' mode requires solo thread
2150 resume_ptid
= inferior_ptid
;
2152 else if ((scheduler_mode
== schedlock_replay
)
2153 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2155 /* User-settable 'scheduler' mode requires solo thread resume in replay
2157 resume_ptid
= inferior_ptid
;
2159 else if (!sched_multi
&& target_supports_multi_process ())
2161 /* Resume all threads of the current process (and none of other
2163 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2167 /* Resume all threads of all processes. */
2168 resume_ptid
= RESUME_ALL
;
2176 process_stratum_target
*
2177 user_visible_resume_target (ptid_t resume_ptid
)
2179 return (resume_ptid
== minus_one_ptid
&& sched_multi
2181 : current_inferior ()->process_target ());
2184 /* Return a ptid representing the set of threads that we will resume,
2185 in the perspective of the target, assuming run control handling
2186 does not require leaving some threads stopped (e.g., stepping past
2187 breakpoint). USER_STEP indicates whether we're about to start the
2188 target for a stepping command. */
2191 internal_resume_ptid (int user_step
)
2193 /* In non-stop, we always control threads individually. Note that
2194 the target may always work in non-stop mode even with "set
2195 non-stop off", in which case user_visible_resume_ptid could
2196 return a wildcard ptid. */
2197 if (target_is_non_stop_p ())
2198 return inferior_ptid
;
2200 return user_visible_resume_ptid (user_step
);
2203 /* Wrapper for target_resume, that handles infrun-specific
2207 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2209 struct thread_info
*tp
= inferior_thread ();
2211 gdb_assert (!tp
->stop_requested
);
2213 /* Install inferior's terminal modes. */
2214 target_terminal::inferior ();
2216 /* Avoid confusing the next resume, if the next stop/resume
2217 happens to apply to another thread. */
2218 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2220 /* Advise target which signals may be handled silently.
2222 If we have removed breakpoints because we are stepping over one
2223 in-line (in any thread), we need to receive all signals to avoid
2224 accidentally skipping a breakpoint during execution of a signal
2227 Likewise if we're displaced stepping, otherwise a trap for a
2228 breakpoint in a signal handler might be confused with the
2229 displaced step finishing. We don't make the displaced_step_fixup
2230 step distinguish the cases instead, because:
2232 - a backtrace while stopped in the signal handler would show the
2233 scratch pad as frame older than the signal handler, instead of
2234 the real mainline code.
2236 - when the thread is later resumed, the signal handler would
2237 return to the scratch pad area, which would no longer be
2239 if (step_over_info_valid_p ()
2240 || displaced_step_in_progress (tp
->inf
))
2241 target_pass_signals ({});
2243 target_pass_signals (signal_pass
);
2245 target_resume (resume_ptid
, step
, sig
);
2247 target_commit_resume ();
2249 if (target_can_async_p ())
2253 /* Resume the inferior. SIG is the signal to give the inferior
2254 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2255 call 'resume', which handles exceptions. */
2258 resume_1 (enum gdb_signal sig
)
2260 struct regcache
*regcache
= get_current_regcache ();
2261 struct gdbarch
*gdbarch
= regcache
->arch ();
2262 struct thread_info
*tp
= inferior_thread ();
2263 const address_space
*aspace
= regcache
->aspace ();
2265 /* This represents the user's step vs continue request. When
2266 deciding whether "set scheduler-locking step" applies, it's the
2267 user's intention that counts. */
2268 const int user_step
= tp
->control
.stepping_command
;
2269 /* This represents what we'll actually request the target to do.
2270 This can decay from a step to a continue, if e.g., we need to
2271 implement single-stepping with breakpoints (software
2275 gdb_assert (!tp
->stop_requested
);
2276 gdb_assert (!thread_is_in_step_over_chain (tp
));
2278 if (tp
->suspend
.waitstatus_pending_p
)
2281 ("thread %s has pending wait "
2282 "status %s (currently_stepping=%d).",
2283 target_pid_to_str (tp
->ptid
).c_str (),
2284 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2285 currently_stepping (tp
));
2287 tp
->inf
->process_target ()->threads_executing
= true;
2290 /* FIXME: What should we do if we are supposed to resume this
2291 thread with a signal? Maybe we should maintain a queue of
2292 pending signals to deliver. */
2293 if (sig
!= GDB_SIGNAL_0
)
2295 warning (_("Couldn't deliver signal %s to %s."),
2296 gdb_signal_to_name (sig
),
2297 target_pid_to_str (tp
->ptid
).c_str ());
2300 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2302 if (target_can_async_p ())
2305 /* Tell the event loop we have an event to process. */
2306 mark_async_event_handler (infrun_async_inferior_event_token
);
2311 tp
->stepped_breakpoint
= 0;
2313 /* Depends on stepped_breakpoint. */
2314 step
= currently_stepping (tp
);
2316 if (current_inferior ()->waiting_for_vfork_done
)
2318 /* Don't try to single-step a vfork parent that is waiting for
2319 the child to get out of the shared memory region (by exec'ing
2320 or exiting). This is particularly important on software
2321 single-step archs, as the child process would trip on the
2322 software single step breakpoint inserted for the parent
2323 process. Since the parent will not actually execute any
2324 instruction until the child is out of the shared region (such
2325 are vfork's semantics), it is safe to simply continue it.
2326 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2327 the parent, and tell it to `keep_going', which automatically
2328 re-sets it stepping. */
2329 infrun_debug_printf ("resume : clear step");
2333 CORE_ADDR pc
= regcache_read_pc (regcache
);
2335 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2336 "current thread [%s] at %s",
2337 step
, gdb_signal_to_symbol_string (sig
),
2338 tp
->control
.trap_expected
,
2339 target_pid_to_str (inferior_ptid
).c_str (),
2340 paddress (gdbarch
, pc
));
2342 /* Normally, by the time we reach `resume', the breakpoints are either
2343 removed or inserted, as appropriate. The exception is if we're sitting
2344 at a permanent breakpoint; we need to step over it, but permanent
2345 breakpoints can't be removed. So we have to test for it here. */
2346 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2348 if (sig
!= GDB_SIGNAL_0
)
2350 /* We have a signal to pass to the inferior. The resume
2351 may, or may not take us to the signal handler. If this
2352 is a step, we'll need to stop in the signal handler, if
2353 there's one, (if the target supports stepping into
2354 handlers), or in the next mainline instruction, if
2355 there's no handler. If this is a continue, we need to be
2356 sure to run the handler with all breakpoints inserted.
2357 In all cases, set a breakpoint at the current address
2358 (where the handler returns to), and once that breakpoint
2359 is hit, resume skipping the permanent breakpoint. If
2360 that breakpoint isn't hit, then we've stepped into the
2361 signal handler (or hit some other event). We'll delete
2362 the step-resume breakpoint then. */
2364 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2365 "deliver signal first");
2367 clear_step_over_info ();
2368 tp
->control
.trap_expected
= 0;
2370 if (tp
->control
.step_resume_breakpoint
== NULL
)
2372 /* Set a "high-priority" step-resume, as we don't want
2373 user breakpoints at PC to trigger (again) when this
2375 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2376 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2378 tp
->step_after_step_resume_breakpoint
= step
;
2381 insert_breakpoints ();
2385 /* There's no signal to pass, we can go ahead and skip the
2386 permanent breakpoint manually. */
2387 infrun_debug_printf ("skipping permanent breakpoint");
2388 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2389 /* Update pc to reflect the new address from which we will
2390 execute instructions. */
2391 pc
= regcache_read_pc (regcache
);
2395 /* We've already advanced the PC, so the stepping part
2396 is done. Now we need to arrange for a trap to be
2397 reported to handle_inferior_event. Set a breakpoint
2398 at the current PC, and run to it. Don't update
2399 prev_pc, because if we end in
2400 switch_back_to_stepped_thread, we want the "expected
2401 thread advanced also" branch to be taken. IOW, we
2402 don't want this thread to step further from PC
2404 gdb_assert (!step_over_info_valid_p ());
2405 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2406 insert_breakpoints ();
2408 resume_ptid
= internal_resume_ptid (user_step
);
2409 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2416 /* If we have a breakpoint to step over, make sure to do a single
2417 step only. Same if we have software watchpoints. */
2418 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2419 tp
->control
.may_range_step
= 0;
2421 /* If displaced stepping is enabled, step over breakpoints by executing a
2422 copy of the instruction at a different address.
2424 We can't use displaced stepping when we have a signal to deliver;
2425 the comments for displaced_step_prepare explain why. The
2426 comments in the handle_inferior event for dealing with 'random
2427 signals' explain what we do instead.
2429 We can't use displaced stepping when we are waiting for vfork_done
2430 event, displaced stepping breaks the vfork child similarly as single
2431 step software breakpoint. */
2432 if (tp
->control
.trap_expected
2433 && use_displaced_stepping (tp
)
2434 && !step_over_info_valid_p ()
2435 && sig
== GDB_SIGNAL_0
2436 && !current_inferior ()->waiting_for_vfork_done
)
2438 int prepared
= displaced_step_prepare (tp
);
2442 infrun_debug_printf ("Got placed in step-over queue");
2444 tp
->control
.trap_expected
= 0;
2447 else if (prepared
< 0)
2449 /* Fallback to stepping over the breakpoint in-line. */
2451 if (target_is_non_stop_p ())
2452 stop_all_threads ();
2454 set_step_over_info (regcache
->aspace (),
2455 regcache_read_pc (regcache
), 0, tp
->global_num
);
2457 step
= maybe_software_singlestep (gdbarch
, pc
);
2459 insert_breakpoints ();
2461 else if (prepared
> 0)
2463 struct displaced_step_inferior_state
*displaced
;
2465 /* Update pc to reflect the new address from which we will
2466 execute instructions due to displaced stepping. */
2467 pc
= regcache_read_pc (get_thread_regcache (tp
));
2469 displaced
= get_displaced_stepping_state (tp
->inf
);
2470 step
= gdbarch_displaced_step_hw_singlestep
2471 (gdbarch
, displaced
->step_closure
.get ());
2475 /* Do we need to do it the hard way, w/temp breakpoints? */
2477 step
= maybe_software_singlestep (gdbarch
, pc
);
2479 /* Currently, our software single-step implementation leads to different
2480 results than hardware single-stepping in one situation: when stepping
2481 into delivering a signal which has an associated signal handler,
2482 hardware single-step will stop at the first instruction of the handler,
2483 while software single-step will simply skip execution of the handler.
2485 For now, this difference in behavior is accepted since there is no
2486 easy way to actually implement single-stepping into a signal handler
2487 without kernel support.
2489 However, there is one scenario where this difference leads to follow-on
2490 problems: if we're stepping off a breakpoint by removing all breakpoints
2491 and then single-stepping. In this case, the software single-step
2492 behavior means that even if there is a *breakpoint* in the signal
2493 handler, GDB still would not stop.
2495 Fortunately, we can at least fix this particular issue. We detect
2496 here the case where we are about to deliver a signal while software
2497 single-stepping with breakpoints removed. In this situation, we
2498 revert the decisions to remove all breakpoints and insert single-
2499 step breakpoints, and instead we install a step-resume breakpoint
2500 at the current address, deliver the signal without stepping, and
2501 once we arrive back at the step-resume breakpoint, actually step
2502 over the breakpoint we originally wanted to step over. */
2503 if (thread_has_single_step_breakpoints_set (tp
)
2504 && sig
!= GDB_SIGNAL_0
2505 && step_over_info_valid_p ())
2507 /* If we have nested signals or a pending signal is delivered
2508 immediately after a handler returns, might already have
2509 a step-resume breakpoint set on the earlier handler. We cannot
2510 set another step-resume breakpoint; just continue on until the
2511 original breakpoint is hit. */
2512 if (tp
->control
.step_resume_breakpoint
== NULL
)
2514 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2515 tp
->step_after_step_resume_breakpoint
= 1;
2518 delete_single_step_breakpoints (tp
);
2520 clear_step_over_info ();
2521 tp
->control
.trap_expected
= 0;
2523 insert_breakpoints ();
2526 /* If STEP is set, it's a request to use hardware stepping
2527 facilities. But in that case, we should never
2528 use singlestep breakpoint. */
2529 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2531 /* Decide the set of threads to ask the target to resume. */
2532 if (tp
->control
.trap_expected
)
2534 /* We're allowing a thread to run past a breakpoint it has
2535 hit, either by single-stepping the thread with the breakpoint
2536 removed, or by displaced stepping, with the breakpoint inserted.
2537 In the former case, we need to single-step only this thread,
2538 and keep others stopped, as they can miss this breakpoint if
2539 allowed to run. That's not really a problem for displaced
2540 stepping, but, we still keep other threads stopped, in case
2541 another thread is also stopped for a breakpoint waiting for
2542 its turn in the displaced stepping queue. */
2543 resume_ptid
= inferior_ptid
;
2546 resume_ptid
= internal_resume_ptid (user_step
);
2548 if (execution_direction
!= EXEC_REVERSE
2549 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2551 /* There are two cases where we currently need to step a
2552 breakpoint instruction when we have a signal to deliver:
2554 - See handle_signal_stop where we handle random signals that
2555 could take out us out of the stepping range. Normally, in
2556 that case we end up continuing (instead of stepping) over the
2557 signal handler with a breakpoint at PC, but there are cases
2558 where we should _always_ single-step, even if we have a
2559 step-resume breakpoint, like when a software watchpoint is
2560 set. Assuming single-stepping and delivering a signal at the
2561 same time would takes us to the signal handler, then we could
2562 have removed the breakpoint at PC to step over it. However,
2563 some hardware step targets (like e.g., Mac OS) can't step
2564 into signal handlers, and for those, we need to leave the
2565 breakpoint at PC inserted, as otherwise if the handler
2566 recurses and executes PC again, it'll miss the breakpoint.
2567 So we leave the breakpoint inserted anyway, but we need to
2568 record that we tried to step a breakpoint instruction, so
2569 that adjust_pc_after_break doesn't end up confused.
2571 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2572 in one thread after another thread that was stepping had been
2573 momentarily paused for a step-over. When we re-resume the
2574 stepping thread, it may be resumed from that address with a
2575 breakpoint that hasn't trapped yet. Seen with
2576 gdb.threads/non-stop-fair-events.exp, on targets that don't
2577 do displaced stepping. */
2579 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2580 target_pid_to_str (tp
->ptid
).c_str ());
2582 tp
->stepped_breakpoint
= 1;
2584 /* Most targets can step a breakpoint instruction, thus
2585 executing it normally. But if this one cannot, just
2586 continue and we will hit it anyway. */
2587 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2592 && tp
->control
.trap_expected
2593 && use_displaced_stepping (tp
)
2594 && !step_over_info_valid_p ())
2596 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2597 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2598 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2601 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2602 paddress (resume_gdbarch
, actual_pc
));
2603 read_memory (actual_pc
, buf
, sizeof (buf
));
2604 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2607 if (tp
->control
.may_range_step
)
2609 /* If we're resuming a thread with the PC out of the step
2610 range, then we're doing some nested/finer run control
2611 operation, like stepping the thread out of the dynamic
2612 linker or the displaced stepping scratch pad. We
2613 shouldn't have allowed a range step then. */
2614 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2617 do_target_resume (resume_ptid
, step
, sig
);
2621 /* Resume the inferior. SIG is the signal to give the inferior
2622 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2623 rolls back state on error. */
2626 resume (gdb_signal sig
)
2632 catch (const gdb_exception
&ex
)
2634 /* If resuming is being aborted for any reason, delete any
2635 single-step breakpoint resume_1 may have created, to avoid
2636 confusing the following resumption, and to avoid leaving
2637 single-step breakpoints perturbing other threads, in case
2638 we're running in non-stop mode. */
2639 if (inferior_ptid
!= null_ptid
)
2640 delete_single_step_breakpoints (inferior_thread ());
2650 /* Counter that tracks number of user visible stops. This can be used
2651 to tell whether a command has proceeded the inferior past the
2652 current location. This allows e.g., inferior function calls in
2653 breakpoint commands to not interrupt the command list. When the
2654 call finishes successfully, the inferior is standing at the same
2655 breakpoint as if nothing happened (and so we don't call
2657 static ULONGEST current_stop_id
;
2664 return current_stop_id
;
2667 /* Called when we report a user visible stop. */
2675 /* Clear out all variables saying what to do when inferior is continued.
2676 First do this, then set the ones you want, then call `proceed'. */
2679 clear_proceed_status_thread (struct thread_info
*tp
)
2681 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2683 /* If we're starting a new sequence, then the previous finished
2684 single-step is no longer relevant. */
2685 if (tp
->suspend
.waitstatus_pending_p
)
2687 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2689 infrun_debug_printf ("pending event of %s was a finished step. "
2691 target_pid_to_str (tp
->ptid
).c_str ());
2693 tp
->suspend
.waitstatus_pending_p
= 0;
2694 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2699 ("thread %s has pending wait status %s (currently_stepping=%d).",
2700 target_pid_to_str (tp
->ptid
).c_str (),
2701 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2702 currently_stepping (tp
));
2706 /* If this signal should not be seen by program, give it zero.
2707 Used for debugging signals. */
2708 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2709 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2711 delete tp
->thread_fsm
;
2712 tp
->thread_fsm
= NULL
;
2714 tp
->control
.trap_expected
= 0;
2715 tp
->control
.step_range_start
= 0;
2716 tp
->control
.step_range_end
= 0;
2717 tp
->control
.may_range_step
= 0;
2718 tp
->control
.step_frame_id
= null_frame_id
;
2719 tp
->control
.step_stack_frame_id
= null_frame_id
;
2720 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2721 tp
->control
.step_start_function
= NULL
;
2722 tp
->stop_requested
= 0;
2724 tp
->control
.stop_step
= 0;
2726 tp
->control
.proceed_to_finish
= 0;
2728 tp
->control
.stepping_command
= 0;
2730 /* Discard any remaining commands or status from previous stop. */
2731 bpstat_clear (&tp
->control
.stop_bpstat
);
2735 clear_proceed_status (int step
)
2737 /* With scheduler-locking replay, stop replaying other threads if we're
2738 not replaying the user-visible resume ptid.
2740 This is a convenience feature to not require the user to explicitly
2741 stop replaying the other threads. We're assuming that the user's
2742 intent is to resume tracing the recorded process. */
2743 if (!non_stop
&& scheduler_mode
== schedlock_replay
2744 && target_record_is_replaying (minus_one_ptid
)
2745 && !target_record_will_replay (user_visible_resume_ptid (step
),
2746 execution_direction
))
2747 target_record_stop_replaying ();
2749 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2751 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2752 process_stratum_target
*resume_target
2753 = user_visible_resume_target (resume_ptid
);
2755 /* In all-stop mode, delete the per-thread status of all threads
2756 we're about to resume, implicitly and explicitly. */
2757 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2758 clear_proceed_status_thread (tp
);
2761 if (inferior_ptid
!= null_ptid
)
2763 struct inferior
*inferior
;
2767 /* If in non-stop mode, only delete the per-thread status of
2768 the current thread. */
2769 clear_proceed_status_thread (inferior_thread ());
2772 inferior
= current_inferior ();
2773 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2776 gdb::observers::about_to_proceed
.notify ();
2779 /* Returns true if TP is still stopped at a breakpoint that needs
2780 stepping-over in order to make progress. If the breakpoint is gone
2781 meanwhile, we can skip the whole step-over dance. */
2784 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2786 if (tp
->stepping_over_breakpoint
)
2788 struct regcache
*regcache
= get_thread_regcache (tp
);
2790 if (breakpoint_here_p (regcache
->aspace (),
2791 regcache_read_pc (regcache
))
2792 == ordinary_breakpoint_here
)
2795 tp
->stepping_over_breakpoint
= 0;
2801 /* Check whether thread TP still needs to start a step-over in order
2802 to make progress when resumed. Returns an bitwise or of enum
2803 step_over_what bits, indicating what needs to be stepped over. */
2805 static step_over_what
2806 thread_still_needs_step_over (struct thread_info
*tp
)
2808 step_over_what what
= 0;
2810 if (thread_still_needs_step_over_bp (tp
))
2811 what
|= STEP_OVER_BREAKPOINT
;
2813 if (tp
->stepping_over_watchpoint
2814 && !target_have_steppable_watchpoint ())
2815 what
|= STEP_OVER_WATCHPOINT
;
2820 /* Returns true if scheduler locking applies. STEP indicates whether
2821 we're about to do a step/next-like command to a thread. */
2824 schedlock_applies (struct thread_info
*tp
)
2826 return (scheduler_mode
== schedlock_on
2827 || (scheduler_mode
== schedlock_step
2828 && tp
->control
.stepping_command
)
2829 || (scheduler_mode
== schedlock_replay
2830 && target_record_will_replay (minus_one_ptid
,
2831 execution_direction
)));
2834 /* Calls target_commit_resume on all targets. */
2837 commit_resume_all_targets ()
2839 scoped_restore_current_thread restore_thread
;
2841 /* Map between process_target and a representative inferior. This
2842 is to avoid committing a resume in the same target more than
2843 once. Resumptions must be idempotent, so this is an
2845 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2847 for (inferior
*inf
: all_non_exited_inferiors ())
2848 if (inf
->has_execution ())
2849 conn_inf
[inf
->process_target ()] = inf
;
2851 for (const auto &ci
: conn_inf
)
2853 inferior
*inf
= ci
.second
;
2854 switch_to_inferior_no_thread (inf
);
2855 target_commit_resume ();
2859 /* Check that all the targets we're about to resume are in non-stop
2860 mode. Ideally, we'd only care whether all targets support
2861 target-async, but we're not there yet. E.g., stop_all_threads
2862 doesn't know how to handle all-stop targets. Also, the remote
2863 protocol in all-stop mode is synchronous, irrespective of
2864 target-async, which means that things like a breakpoint re-set
2865 triggered by one target would try to read memory from all targets
2869 check_multi_target_resumption (process_stratum_target
*resume_target
)
2871 if (!non_stop
&& resume_target
== nullptr)
2873 scoped_restore_current_thread restore_thread
;
2875 /* This is used to track whether we're resuming more than one
2877 process_stratum_target
*first_connection
= nullptr;
2879 /* The first inferior we see with a target that does not work in
2880 always-non-stop mode. */
2881 inferior
*first_not_non_stop
= nullptr;
2883 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2885 switch_to_inferior_no_thread (inf
);
2887 if (!target_has_execution ())
2890 process_stratum_target
*proc_target
2891 = current_inferior ()->process_target();
2893 if (!target_is_non_stop_p ())
2894 first_not_non_stop
= inf
;
2896 if (first_connection
== nullptr)
2897 first_connection
= proc_target
;
2898 else if (first_connection
!= proc_target
2899 && first_not_non_stop
!= nullptr)
2901 switch_to_inferior_no_thread (first_not_non_stop
);
2903 proc_target
= current_inferior ()->process_target();
2905 error (_("Connection %d (%s) does not support "
2906 "multi-target resumption."),
2907 proc_target
->connection_number
,
2908 make_target_connection_string (proc_target
).c_str ());
2914 /* Basic routine for continuing the program in various fashions.
2916 ADDR is the address to resume at, or -1 for resume where stopped.
2917 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2918 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2920 You should call clear_proceed_status before calling proceed. */
2923 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2925 struct regcache
*regcache
;
2926 struct gdbarch
*gdbarch
;
2928 struct execution_control_state ecss
;
2929 struct execution_control_state
*ecs
= &ecss
;
2932 /* If we're stopped at a fork/vfork, follow the branch set by the
2933 "set follow-fork-mode" command; otherwise, we'll just proceed
2934 resuming the current thread. */
2935 if (!follow_fork ())
2937 /* The target for some reason decided not to resume. */
2939 if (target_can_async_p ())
2940 inferior_event_handler (INF_EXEC_COMPLETE
);
2944 /* We'll update this if & when we switch to a new thread. */
2945 previous_inferior_ptid
= inferior_ptid
;
2947 regcache
= get_current_regcache ();
2948 gdbarch
= regcache
->arch ();
2949 const address_space
*aspace
= regcache
->aspace ();
2951 pc
= regcache_read_pc_protected (regcache
);
2953 thread_info
*cur_thr
= inferior_thread ();
2955 /* Fill in with reasonable starting values. */
2956 init_thread_stepping_state (cur_thr
);
2958 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2961 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2962 process_stratum_target
*resume_target
2963 = user_visible_resume_target (resume_ptid
);
2965 check_multi_target_resumption (resume_target
);
2967 if (addr
== (CORE_ADDR
) -1)
2969 if (pc
== cur_thr
->suspend
.stop_pc
2970 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2971 && execution_direction
!= EXEC_REVERSE
)
2972 /* There is a breakpoint at the address we will resume at,
2973 step one instruction before inserting breakpoints so that
2974 we do not stop right away (and report a second hit at this
2977 Note, we don't do this in reverse, because we won't
2978 actually be executing the breakpoint insn anyway.
2979 We'll be (un-)executing the previous instruction. */
2980 cur_thr
->stepping_over_breakpoint
= 1;
2981 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2982 && gdbarch_single_step_through_delay (gdbarch
,
2983 get_current_frame ()))
2984 /* We stepped onto an instruction that needs to be stepped
2985 again before re-inserting the breakpoint, do so. */
2986 cur_thr
->stepping_over_breakpoint
= 1;
2990 regcache_write_pc (regcache
, addr
);
2993 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2994 cur_thr
->suspend
.stop_signal
= siggnal
;
2996 /* If an exception is thrown from this point on, make sure to
2997 propagate GDB's knowledge of the executing state to the
2998 frontend/user running state. */
2999 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3001 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3002 threads (e.g., we might need to set threads stepping over
3003 breakpoints first), from the user/frontend's point of view, all
3004 threads in RESUME_PTID are now running. Unless we're calling an
3005 inferior function, as in that case we pretend the inferior
3006 doesn't run at all. */
3007 if (!cur_thr
->control
.in_infcall
)
3008 set_running (resume_target
, resume_ptid
, true);
3010 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3011 gdb_signal_to_symbol_string (siggnal
));
3013 annotate_starting ();
3015 /* Make sure that output from GDB appears before output from the
3017 gdb_flush (gdb_stdout
);
3019 /* Since we've marked the inferior running, give it the terminal. A
3020 QUIT/Ctrl-C from here on is forwarded to the target (which can
3021 still detect attempts to unblock a stuck connection with repeated
3022 Ctrl-C from within target_pass_ctrlc). */
3023 target_terminal::inferior ();
3025 /* In a multi-threaded task we may select another thread and
3026 then continue or step.
3028 But if a thread that we're resuming had stopped at a breakpoint,
3029 it will immediately cause another breakpoint stop without any
3030 execution (i.e. it will report a breakpoint hit incorrectly). So
3031 we must step over it first.
3033 Look for threads other than the current (TP) that reported a
3034 breakpoint hit and haven't been resumed yet since. */
3036 /* If scheduler locking applies, we can avoid iterating over all
3038 if (!non_stop
&& !schedlock_applies (cur_thr
))
3040 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3043 switch_to_thread_no_regs (tp
);
3045 /* Ignore the current thread here. It's handled
3050 if (!thread_still_needs_step_over (tp
))
3053 gdb_assert (!thread_is_in_step_over_chain (tp
));
3055 infrun_debug_printf ("need to step-over [%s] first",
3056 target_pid_to_str (tp
->ptid
).c_str ());
3058 thread_step_over_chain_enqueue (tp
);
3061 switch_to_thread (cur_thr
);
3064 /* Enqueue the current thread last, so that we move all other
3065 threads over their breakpoints first. */
3066 if (cur_thr
->stepping_over_breakpoint
)
3067 thread_step_over_chain_enqueue (cur_thr
);
3069 /* If the thread isn't started, we'll still need to set its prev_pc,
3070 so that switch_back_to_stepped_thread knows the thread hasn't
3071 advanced. Must do this before resuming any thread, as in
3072 all-stop/remote, once we resume we can't send any other packet
3073 until the target stops again. */
3074 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3077 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3079 started
= start_step_over ();
3081 if (step_over_info_valid_p ())
3083 /* Either this thread started a new in-line step over, or some
3084 other thread was already doing one. In either case, don't
3085 resume anything else until the step-over is finished. */
3087 else if (started
&& !target_is_non_stop_p ())
3089 /* A new displaced stepping sequence was started. In all-stop,
3090 we can't talk to the target anymore until it next stops. */
3092 else if (!non_stop
&& target_is_non_stop_p ())
3094 /* In all-stop, but the target is always in non-stop mode.
3095 Start all other threads that are implicitly resumed too. */
3096 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3099 switch_to_thread_no_regs (tp
);
3101 if (!tp
->inf
->has_execution ())
3103 infrun_debug_printf ("[%s] target has no execution",
3104 target_pid_to_str (tp
->ptid
).c_str ());
3110 infrun_debug_printf ("[%s] resumed",
3111 target_pid_to_str (tp
->ptid
).c_str ());
3112 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3116 if (thread_is_in_step_over_chain (tp
))
3118 infrun_debug_printf ("[%s] needs step-over",
3119 target_pid_to_str (tp
->ptid
).c_str ());
3123 infrun_debug_printf ("resuming %s",
3124 target_pid_to_str (tp
->ptid
).c_str ());
3126 reset_ecs (ecs
, tp
);
3127 switch_to_thread (tp
);
3128 keep_going_pass_signal (ecs
);
3129 if (!ecs
->wait_some_more
)
3130 error (_("Command aborted."));
3133 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3135 /* The thread wasn't started, and isn't queued, run it now. */
3136 reset_ecs (ecs
, cur_thr
);
3137 switch_to_thread (cur_thr
);
3138 keep_going_pass_signal (ecs
);
3139 if (!ecs
->wait_some_more
)
3140 error (_("Command aborted."));
3144 commit_resume_all_targets ();
3146 finish_state
.release ();
3148 /* If we've switched threads above, switch back to the previously
3149 current thread. We don't want the user to see a different
3151 switch_to_thread (cur_thr
);
3153 /* Tell the event loop to wait for it to stop. If the target
3154 supports asynchronous execution, it'll do this from within
3156 if (!target_can_async_p ())
3157 mark_async_event_handler (infrun_async_inferior_event_token
);
3161 /* Start remote-debugging of a machine over a serial link. */
3164 start_remote (int from_tty
)
3166 inferior
*inf
= current_inferior ();
3167 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3169 /* Always go on waiting for the target, regardless of the mode. */
3170 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3171 indicate to wait_for_inferior that a target should timeout if
3172 nothing is returned (instead of just blocking). Because of this,
3173 targets expecting an immediate response need to, internally, set
3174 things up so that the target_wait() is forced to eventually
3176 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3177 differentiate to its caller what the state of the target is after
3178 the initial open has been performed. Here we're assuming that
3179 the target has stopped. It should be possible to eventually have
3180 target_open() return to the caller an indication that the target
3181 is currently running and GDB state should be set to the same as
3182 for an async run. */
3183 wait_for_inferior (inf
);
3185 /* Now that the inferior has stopped, do any bookkeeping like
3186 loading shared libraries. We want to do this before normal_stop,
3187 so that the displayed frame is up to date. */
3188 post_create_inferior (from_tty
);
3193 /* Initialize static vars when a new inferior begins. */
3196 init_wait_for_inferior (void)
3198 /* These are meaningless until the first time through wait_for_inferior. */
3200 breakpoint_init_inferior (inf_starting
);
3202 clear_proceed_status (0);
3204 nullify_last_target_wait_ptid ();
3206 previous_inferior_ptid
= inferior_ptid
;
3211 static void handle_inferior_event (struct execution_control_state
*ecs
);
3213 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3214 struct execution_control_state
*ecs
);
3215 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3216 struct execution_control_state
*ecs
);
3217 static void handle_signal_stop (struct execution_control_state
*ecs
);
3218 static void check_exception_resume (struct execution_control_state
*,
3219 struct frame_info
*);
3221 static void end_stepping_range (struct execution_control_state
*ecs
);
3222 static void stop_waiting (struct execution_control_state
*ecs
);
3223 static void keep_going (struct execution_control_state
*ecs
);
3224 static void process_event_stop_test (struct execution_control_state
*ecs
);
3225 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3227 /* This function is attached as a "thread_stop_requested" observer.
3228 Cleanup local state that assumed the PTID was to be resumed, and
3229 report the stop to the frontend. */
3232 infrun_thread_stop_requested (ptid_t ptid
)
3234 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3236 /* PTID was requested to stop. If the thread was already stopped,
3237 but the user/frontend doesn't know about that yet (e.g., the
3238 thread had been temporarily paused for some step-over), set up
3239 for reporting the stop now. */
3240 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3242 if (tp
->state
!= THREAD_RUNNING
)
3247 /* Remove matching threads from the step-over queue, so
3248 start_step_over doesn't try to resume them
3250 if (thread_is_in_step_over_chain (tp
))
3251 thread_step_over_chain_remove (tp
);
3253 /* If the thread is stopped, but the user/frontend doesn't
3254 know about that yet, queue a pending event, as if the
3255 thread had just stopped now. Unless the thread already had
3257 if (!tp
->suspend
.waitstatus_pending_p
)
3259 tp
->suspend
.waitstatus_pending_p
= 1;
3260 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3261 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3264 /* Clear the inline-frame state, since we're re-processing the
3266 clear_inline_frame_state (tp
);
3268 /* If this thread was paused because some other thread was
3269 doing an inline-step over, let that finish first. Once
3270 that happens, we'll restart all threads and consume pending
3271 stop events then. */
3272 if (step_over_info_valid_p ())
3275 /* Otherwise we can process the (new) pending event now. Set
3276 it so this pending event is considered by
3283 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3285 if (target_last_proc_target
== tp
->inf
->process_target ()
3286 && target_last_wait_ptid
== tp
->ptid
)
3287 nullify_last_target_wait_ptid ();
3290 /* Delete the step resume, single-step and longjmp/exception resume
3291 breakpoints of TP. */
3294 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3296 delete_step_resume_breakpoint (tp
);
3297 delete_exception_resume_breakpoint (tp
);
3298 delete_single_step_breakpoints (tp
);
3301 /* If the target still has execution, call FUNC for each thread that
3302 just stopped. In all-stop, that's all the non-exited threads; in
3303 non-stop, that's the current thread, only. */
3305 typedef void (*for_each_just_stopped_thread_callback_func
)
3306 (struct thread_info
*tp
);
3309 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3311 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3314 if (target_is_non_stop_p ())
3316 /* If in non-stop mode, only the current thread stopped. */
3317 func (inferior_thread ());
3321 /* In all-stop mode, all threads have stopped. */
3322 for (thread_info
*tp
: all_non_exited_threads ())
3327 /* Delete the step resume and longjmp/exception resume breakpoints of
3328 the threads that just stopped. */
3331 delete_just_stopped_threads_infrun_breakpoints (void)
3333 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3336 /* Delete the single-step breakpoints of the threads that just
3340 delete_just_stopped_threads_single_step_breakpoints (void)
3342 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3348 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3349 const struct target_waitstatus
*ws
)
3351 std::string status_string
= target_waitstatus_to_string (ws
);
3354 /* The text is split over several lines because it was getting too long.
3355 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3356 output as a unit; we want only one timestamp printed if debug_timestamp
3359 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3362 waiton_ptid
.tid ());
3363 if (waiton_ptid
.pid () != -1)
3364 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3365 stb
.printf (", status) =\n");
3366 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3370 target_pid_to_str (result_ptid
).c_str ());
3371 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3373 /* This uses %s in part to handle %'s in the text, but also to avoid
3374 a gcc error: the format attribute requires a string literal. */
3375 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3378 /* Select a thread at random, out of those which are resumed and have
3381 static struct thread_info
*
3382 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3386 auto has_event
= [&] (thread_info
*tp
)
3388 return (tp
->ptid
.matches (waiton_ptid
)
3390 && tp
->suspend
.waitstatus_pending_p
);
3393 /* First see how many events we have. Count only resumed threads
3394 that have an event pending. */
3395 for (thread_info
*tp
: inf
->non_exited_threads ())
3399 if (num_events
== 0)
3402 /* Now randomly pick a thread out of those that have had events. */
3403 int random_selector
= (int) ((num_events
* (double) rand ())
3404 / (RAND_MAX
+ 1.0));
3407 infrun_debug_printf ("Found %d events, selecting #%d",
3408 num_events
, random_selector
);
3410 /* Select the Nth thread that has had an event. */
3411 for (thread_info
*tp
: inf
->non_exited_threads ())
3413 if (random_selector
-- == 0)
3416 gdb_assert_not_reached ("event thread not found");
3419 /* Wrapper for target_wait that first checks whether threads have
3420 pending statuses to report before actually asking the target for
3421 more events. INF is the inferior we're using to call target_wait
3425 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3426 target_waitstatus
*status
, target_wait_flags options
)
3429 struct thread_info
*tp
;
3431 /* We know that we are looking for an event in the target of inferior
3432 INF, but we don't know which thread the event might come from. As
3433 such we want to make sure that INFERIOR_PTID is reset so that none of
3434 the wait code relies on it - doing so is always a mistake. */
3435 switch_to_inferior_no_thread (inf
);
3437 /* First check if there is a resumed thread with a wait status
3439 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3441 tp
= random_pending_event_thread (inf
, ptid
);
3445 infrun_debug_printf ("Waiting for specific thread %s.",
3446 target_pid_to_str (ptid
).c_str ());
3448 /* We have a specific thread to check. */
3449 tp
= find_thread_ptid (inf
, ptid
);
3450 gdb_assert (tp
!= NULL
);
3451 if (!tp
->suspend
.waitstatus_pending_p
)
3456 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3457 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3459 struct regcache
*regcache
= get_thread_regcache (tp
);
3460 struct gdbarch
*gdbarch
= regcache
->arch ();
3464 pc
= regcache_read_pc (regcache
);
3466 if (pc
!= tp
->suspend
.stop_pc
)
3468 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3469 target_pid_to_str (tp
->ptid
).c_str (),
3470 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3471 paddress (gdbarch
, pc
));
3474 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3476 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3477 target_pid_to_str (tp
->ptid
).c_str (),
3478 paddress (gdbarch
, pc
));
3485 infrun_debug_printf ("pending event of %s cancelled.",
3486 target_pid_to_str (tp
->ptid
).c_str ());
3488 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3489 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3495 infrun_debug_printf ("Using pending wait status %s for %s.",
3496 target_waitstatus_to_string
3497 (&tp
->suspend
.waitstatus
).c_str (),
3498 target_pid_to_str (tp
->ptid
).c_str ());
3500 /* Now that we've selected our final event LWP, un-adjust its PC
3501 if it was a software breakpoint (and the target doesn't
3502 always adjust the PC itself). */
3503 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3504 && !target_supports_stopped_by_sw_breakpoint ())
3506 struct regcache
*regcache
;
3507 struct gdbarch
*gdbarch
;
3510 regcache
= get_thread_regcache (tp
);
3511 gdbarch
= regcache
->arch ();
3513 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3518 pc
= regcache_read_pc (regcache
);
3519 regcache_write_pc (regcache
, pc
+ decr_pc
);
3523 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3524 *status
= tp
->suspend
.waitstatus
;
3525 tp
->suspend
.waitstatus_pending_p
= 0;
3527 /* Wake up the event loop again, until all pending events are
3529 if (target_is_async_p ())
3530 mark_async_event_handler (infrun_async_inferior_event_token
);
3534 /* But if we don't find one, we'll have to wait. */
3536 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3538 if (!target_can_async_p ())
3539 options
&= ~TARGET_WNOHANG
;
3541 if (deprecated_target_wait_hook
)
3542 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3544 event_ptid
= target_wait (ptid
, status
, options
);
3549 /* Wrapper for target_wait that first checks whether threads have
3550 pending statuses to report before actually asking the target for
3551 more events. Polls for events from all inferiors/targets. */
3554 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3555 target_wait_flags options
)
3557 int num_inferiors
= 0;
3558 int random_selector
;
3560 /* For fairness, we pick the first inferior/target to poll at random
3561 out of all inferiors that may report events, and then continue
3562 polling the rest of the inferior list starting from that one in a
3563 circular fashion until the whole list is polled once. */
3565 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3567 return (inf
->process_target () != NULL
3568 && ptid_t (inf
->pid
).matches (wait_ptid
));
3571 /* First see how many matching inferiors we have. */
3572 for (inferior
*inf
: all_inferiors ())
3573 if (inferior_matches (inf
))
3576 if (num_inferiors
== 0)
3578 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3582 /* Now randomly pick an inferior out of those that matched. */
3583 random_selector
= (int)
3584 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3586 if (num_inferiors
> 1)
3587 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3588 num_inferiors
, random_selector
);
3590 /* Select the Nth inferior that matched. */
3592 inferior
*selected
= nullptr;
3594 for (inferior
*inf
: all_inferiors ())
3595 if (inferior_matches (inf
))
3596 if (random_selector
-- == 0)
3602 /* Now poll for events out of each of the matching inferior's
3603 targets, starting from the selected one. */
3605 auto do_wait
= [&] (inferior
*inf
)
3607 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3608 ecs
->target
= inf
->process_target ();
3609 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3612 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3613 here spuriously after the target is all stopped and we've already
3614 reported the stop to the user, polling for events. */
3615 scoped_restore_current_thread restore_thread
;
3617 int inf_num
= selected
->num
;
3618 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3619 if (inferior_matches (inf
))
3623 for (inferior
*inf
= inferior_list
;
3624 inf
!= NULL
&& inf
->num
< inf_num
;
3626 if (inferior_matches (inf
))
3630 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3634 /* Prepare and stabilize the inferior for detaching it. E.g.,
3635 detaching while a thread is displaced stepping is a recipe for
3636 crashing it, as nothing would readjust the PC out of the scratch
3640 prepare_for_detach (void)
3642 struct inferior
*inf
= current_inferior ();
3643 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3645 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3647 /* Is any thread of this process displaced stepping? If not,
3648 there's nothing else to do. */
3649 if (displaced
->step_thread
== nullptr)
3652 infrun_debug_printf ("displaced-stepping in-process while detaching");
3654 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3656 while (displaced
->step_thread
!= nullptr)
3658 struct execution_control_state ecss
;
3659 struct execution_control_state
*ecs
;
3662 memset (ecs
, 0, sizeof (*ecs
));
3664 overlay_cache_invalid
= 1;
3665 /* Flush target cache before starting to handle each event.
3666 Target was running and cache could be stale. This is just a
3667 heuristic. Running threads may modify target memory, but we
3668 don't get any event. */
3669 target_dcache_invalidate ();
3671 do_target_wait (pid_ptid
, ecs
, 0);
3674 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3676 /* If an error happens while handling the event, propagate GDB's
3677 knowledge of the executing state to the frontend/user running
3679 scoped_finish_thread_state
finish_state (inf
->process_target (),
3682 /* Now figure out what to do with the result of the result. */
3683 handle_inferior_event (ecs
);
3685 /* No error, don't finish the state yet. */
3686 finish_state
.release ();
3688 /* Breakpoints and watchpoints are not installed on the target
3689 at this point, and signals are passed directly to the
3690 inferior, so this must mean the process is gone. */
3691 if (!ecs
->wait_some_more
)
3693 restore_detaching
.release ();
3694 error (_("Program exited while detaching"));
3698 restore_detaching
.release ();
3701 /* Wait for control to return from inferior to debugger.
3703 If inferior gets a signal, we may decide to start it up again
3704 instead of returning. That is why there is a loop in this function.
3705 When this function actually returns it means the inferior
3706 should be left stopped and GDB should read more commands. */
3709 wait_for_inferior (inferior
*inf
)
3711 infrun_debug_printf ("wait_for_inferior ()");
3713 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3715 /* If an error happens while handling the event, propagate GDB's
3716 knowledge of the executing state to the frontend/user running
3718 scoped_finish_thread_state finish_state
3719 (inf
->process_target (), minus_one_ptid
);
3723 struct execution_control_state ecss
;
3724 struct execution_control_state
*ecs
= &ecss
;
3726 memset (ecs
, 0, sizeof (*ecs
));
3728 overlay_cache_invalid
= 1;
3730 /* Flush target cache before starting to handle each event.
3731 Target was running and cache could be stale. This is just a
3732 heuristic. Running threads may modify target memory, but we
3733 don't get any event. */
3734 target_dcache_invalidate ();
3736 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3737 ecs
->target
= inf
->process_target ();
3740 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3742 /* Now figure out what to do with the result of the result. */
3743 handle_inferior_event (ecs
);
3745 if (!ecs
->wait_some_more
)
3749 /* No error, don't finish the state yet. */
3750 finish_state
.release ();
3753 /* Cleanup that reinstalls the readline callback handler, if the
3754 target is running in the background. If while handling the target
3755 event something triggered a secondary prompt, like e.g., a
3756 pagination prompt, we'll have removed the callback handler (see
3757 gdb_readline_wrapper_line). Need to do this as we go back to the
3758 event loop, ready to process further input. Note this has no
3759 effect if the handler hasn't actually been removed, because calling
3760 rl_callback_handler_install resets the line buffer, thus losing
3764 reinstall_readline_callback_handler_cleanup ()
3766 struct ui
*ui
= current_ui
;
3770 /* We're not going back to the top level event loop yet. Don't
3771 install the readline callback, as it'd prep the terminal,
3772 readline-style (raw, noecho) (e.g., --batch). We'll install
3773 it the next time the prompt is displayed, when we're ready
3778 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3779 gdb_rl_callback_handler_reinstall ();
3782 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3783 that's just the event thread. In all-stop, that's all threads. */
3786 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3788 if (ecs
->event_thread
!= NULL
3789 && ecs
->event_thread
->thread_fsm
!= NULL
)
3790 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3794 for (thread_info
*thr
: all_non_exited_threads ())
3796 if (thr
->thread_fsm
== NULL
)
3798 if (thr
== ecs
->event_thread
)
3801 switch_to_thread (thr
);
3802 thr
->thread_fsm
->clean_up (thr
);
3805 if (ecs
->event_thread
!= NULL
)
3806 switch_to_thread (ecs
->event_thread
);
3810 /* Helper for all_uis_check_sync_execution_done that works on the
3814 check_curr_ui_sync_execution_done (void)
3816 struct ui
*ui
= current_ui
;
3818 if (ui
->prompt_state
== PROMPT_NEEDED
3820 && !gdb_in_secondary_prompt_p (ui
))
3822 target_terminal::ours ();
3823 gdb::observers::sync_execution_done
.notify ();
3824 ui_register_input_event_handler (ui
);
3831 all_uis_check_sync_execution_done (void)
3833 SWITCH_THRU_ALL_UIS ()
3835 check_curr_ui_sync_execution_done ();
3842 all_uis_on_sync_execution_starting (void)
3844 SWITCH_THRU_ALL_UIS ()
3846 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3847 async_disable_stdin ();
3851 /* Asynchronous version of wait_for_inferior. It is called by the
3852 event loop whenever a change of state is detected on the file
3853 descriptor corresponding to the target. It can be called more than
3854 once to complete a single execution command. In such cases we need
3855 to keep the state in a global variable ECSS. If it is the last time
3856 that this function is called for a single execution command, then
3857 report to the user that the inferior has stopped, and do the
3858 necessary cleanups. */
3861 fetch_inferior_event ()
3863 struct execution_control_state ecss
;
3864 struct execution_control_state
*ecs
= &ecss
;
3867 memset (ecs
, 0, sizeof (*ecs
));
3869 /* Events are always processed with the main UI as current UI. This
3870 way, warnings, debug output, etc. are always consistently sent to
3871 the main console. */
3872 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3874 /* End up with readline processing input, if necessary. */
3876 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3878 /* We're handling a live event, so make sure we're doing live
3879 debugging. If we're looking at traceframes while the target is
3880 running, we're going to need to get back to that mode after
3881 handling the event. */
3882 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3885 maybe_restore_traceframe
.emplace ();
3886 set_current_traceframe (-1);
3889 /* The user/frontend should not notice a thread switch due to
3890 internal events. Make sure we revert to the user selected
3891 thread and frame after handling the event and running any
3892 breakpoint commands. */
3893 scoped_restore_current_thread restore_thread
;
3895 overlay_cache_invalid
= 1;
3896 /* Flush target cache before starting to handle each event. Target
3897 was running and cache could be stale. This is just a heuristic.
3898 Running threads may modify target memory, but we don't get any
3900 target_dcache_invalidate ();
3902 scoped_restore save_exec_dir
3903 = make_scoped_restore (&execution_direction
,
3904 target_execution_direction ());
3906 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3909 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3911 /* Switch to the target that generated the event, so we can do
3913 switch_to_target_no_thread (ecs
->target
);
3916 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3918 /* If an error happens while handling the event, propagate GDB's
3919 knowledge of the executing state to the frontend/user running
3921 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3922 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3924 /* Get executed before scoped_restore_current_thread above to apply
3925 still for the thread which has thrown the exception. */
3926 auto defer_bpstat_clear
3927 = make_scope_exit (bpstat_clear_actions
);
3928 auto defer_delete_threads
3929 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3931 /* Now figure out what to do with the result of the result. */
3932 handle_inferior_event (ecs
);
3934 if (!ecs
->wait_some_more
)
3936 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3937 int should_stop
= 1;
3938 struct thread_info
*thr
= ecs
->event_thread
;
3940 delete_just_stopped_threads_infrun_breakpoints ();
3944 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3946 if (thread_fsm
!= NULL
)
3947 should_stop
= thread_fsm
->should_stop (thr
);
3956 bool should_notify_stop
= true;
3959 clean_up_just_stopped_threads_fsms (ecs
);
3961 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3962 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3964 if (should_notify_stop
)
3966 /* We may not find an inferior if this was a process exit. */
3967 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3968 proceeded
= normal_stop ();
3973 inferior_event_handler (INF_EXEC_COMPLETE
);
3977 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3978 previously selected thread is gone. We have two
3979 choices - switch to no thread selected, or restore the
3980 previously selected thread (now exited). We chose the
3981 later, just because that's what GDB used to do. After
3982 this, "info threads" says "The current thread <Thread
3983 ID 2> has terminated." instead of "No thread
3987 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3988 restore_thread
.dont_restore ();
3992 defer_delete_threads
.release ();
3993 defer_bpstat_clear
.release ();
3995 /* No error, don't finish the thread states yet. */
3996 finish_state
.release ();
3998 /* This scope is used to ensure that readline callbacks are
3999 reinstalled here. */
4002 /* If a UI was in sync execution mode, and now isn't, restore its
4003 prompt (a synchronous execution command has finished, and we're
4004 ready for input). */
4005 all_uis_check_sync_execution_done ();
4008 && exec_done_display_p
4009 && (inferior_ptid
== null_ptid
4010 || inferior_thread ()->state
!= THREAD_RUNNING
))
4011 printf_unfiltered (_("completed.\n"));
4017 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4018 struct symtab_and_line sal
)
4020 /* This can be removed once this function no longer implicitly relies on the
4021 inferior_ptid value. */
4022 gdb_assert (inferior_ptid
== tp
->ptid
);
4024 tp
->control
.step_frame_id
= get_frame_id (frame
);
4025 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4027 tp
->current_symtab
= sal
.symtab
;
4028 tp
->current_line
= sal
.line
;
4031 /* Clear context switchable stepping state. */
4034 init_thread_stepping_state (struct thread_info
*tss
)
4036 tss
->stepped_breakpoint
= 0;
4037 tss
->stepping_over_breakpoint
= 0;
4038 tss
->stepping_over_watchpoint
= 0;
4039 tss
->step_after_step_resume_breakpoint
= 0;
4045 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4046 target_waitstatus status
)
4048 target_last_proc_target
= target
;
4049 target_last_wait_ptid
= ptid
;
4050 target_last_waitstatus
= status
;
4056 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4057 target_waitstatus
*status
)
4059 if (target
!= nullptr)
4060 *target
= target_last_proc_target
;
4061 if (ptid
!= nullptr)
4062 *ptid
= target_last_wait_ptid
;
4063 if (status
!= nullptr)
4064 *status
= target_last_waitstatus
;
4070 nullify_last_target_wait_ptid (void)
4072 target_last_proc_target
= nullptr;
4073 target_last_wait_ptid
= minus_one_ptid
;
4074 target_last_waitstatus
= {};
4077 /* Switch thread contexts. */
4080 context_switch (execution_control_state
*ecs
)
4082 if (ecs
->ptid
!= inferior_ptid
4083 && (inferior_ptid
== null_ptid
4084 || ecs
->event_thread
!= inferior_thread ()))
4086 infrun_debug_printf ("Switching context from %s to %s",
4087 target_pid_to_str (inferior_ptid
).c_str (),
4088 target_pid_to_str (ecs
->ptid
).c_str ());
4091 switch_to_thread (ecs
->event_thread
);
4094 /* If the target can't tell whether we've hit breakpoints
4095 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4096 check whether that could have been caused by a breakpoint. If so,
4097 adjust the PC, per gdbarch_decr_pc_after_break. */
4100 adjust_pc_after_break (struct thread_info
*thread
,
4101 struct target_waitstatus
*ws
)
4103 struct regcache
*regcache
;
4104 struct gdbarch
*gdbarch
;
4105 CORE_ADDR breakpoint_pc
, decr_pc
;
4107 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4108 we aren't, just return.
4110 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4111 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4112 implemented by software breakpoints should be handled through the normal
4115 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4116 different signals (SIGILL or SIGEMT for instance), but it is less
4117 clear where the PC is pointing afterwards. It may not match
4118 gdbarch_decr_pc_after_break. I don't know any specific target that
4119 generates these signals at breakpoints (the code has been in GDB since at
4120 least 1992) so I can not guess how to handle them here.
4122 In earlier versions of GDB, a target with
4123 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4124 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4125 target with both of these set in GDB history, and it seems unlikely to be
4126 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4128 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4131 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4134 /* In reverse execution, when a breakpoint is hit, the instruction
4135 under it has already been de-executed. The reported PC always
4136 points at the breakpoint address, so adjusting it further would
4137 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4140 B1 0x08000000 : INSN1
4141 B2 0x08000001 : INSN2
4143 PC -> 0x08000003 : INSN4
4145 Say you're stopped at 0x08000003 as above. Reverse continuing
4146 from that point should hit B2 as below. Reading the PC when the
4147 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4148 been de-executed already.
4150 B1 0x08000000 : INSN1
4151 B2 PC -> 0x08000001 : INSN2
4155 We can't apply the same logic as for forward execution, because
4156 we would wrongly adjust the PC to 0x08000000, since there's a
4157 breakpoint at PC - 1. We'd then report a hit on B1, although
4158 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4160 if (execution_direction
== EXEC_REVERSE
)
4163 /* If the target can tell whether the thread hit a SW breakpoint,
4164 trust it. Targets that can tell also adjust the PC
4166 if (target_supports_stopped_by_sw_breakpoint ())
4169 /* Note that relying on whether a breakpoint is planted in memory to
4170 determine this can fail. E.g,. the breakpoint could have been
4171 removed since. Or the thread could have been told to step an
4172 instruction the size of a breakpoint instruction, and only
4173 _after_ was a breakpoint inserted at its address. */
4175 /* If this target does not decrement the PC after breakpoints, then
4176 we have nothing to do. */
4177 regcache
= get_thread_regcache (thread
);
4178 gdbarch
= regcache
->arch ();
4180 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4184 const address_space
*aspace
= regcache
->aspace ();
4186 /* Find the location where (if we've hit a breakpoint) the
4187 breakpoint would be. */
4188 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4190 /* If the target can't tell whether a software breakpoint triggered,
4191 fallback to figuring it out based on breakpoints we think were
4192 inserted in the target, and on whether the thread was stepped or
4195 /* Check whether there actually is a software breakpoint inserted at
4198 If in non-stop mode, a race condition is possible where we've
4199 removed a breakpoint, but stop events for that breakpoint were
4200 already queued and arrive later. To suppress those spurious
4201 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4202 and retire them after a number of stop events are reported. Note
4203 this is an heuristic and can thus get confused. The real fix is
4204 to get the "stopped by SW BP and needs adjustment" info out of
4205 the target/kernel (and thus never reach here; see above). */
4206 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4207 || (target_is_non_stop_p ()
4208 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4210 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4212 if (record_full_is_used ())
4213 restore_operation_disable
.emplace
4214 (record_full_gdb_operation_disable_set ());
4216 /* When using hardware single-step, a SIGTRAP is reported for both
4217 a completed single-step and a software breakpoint. Need to
4218 differentiate between the two, as the latter needs adjusting
4219 but the former does not.
4221 The SIGTRAP can be due to a completed hardware single-step only if
4222 - we didn't insert software single-step breakpoints
4223 - this thread is currently being stepped
4225 If any of these events did not occur, we must have stopped due
4226 to hitting a software breakpoint, and have to back up to the
4229 As a special case, we could have hardware single-stepped a
4230 software breakpoint. In this case (prev_pc == breakpoint_pc),
4231 we also need to back up to the breakpoint address. */
4233 if (thread_has_single_step_breakpoints_set (thread
)
4234 || !currently_stepping (thread
)
4235 || (thread
->stepped_breakpoint
4236 && thread
->prev_pc
== breakpoint_pc
))
4237 regcache_write_pc (regcache
, breakpoint_pc
);
4242 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4244 for (frame
= get_prev_frame (frame
);
4246 frame
= get_prev_frame (frame
))
4248 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4251 if (get_frame_type (frame
) != INLINE_FRAME
)
4258 /* Look for an inline frame that is marked for skip.
4259 If PREV_FRAME is TRUE start at the previous frame,
4260 otherwise start at the current frame. Stop at the
4261 first non-inline frame, or at the frame where the
4265 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4267 struct frame_info
*frame
= get_current_frame ();
4270 frame
= get_prev_frame (frame
);
4272 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4274 const char *fn
= NULL
;
4275 symtab_and_line sal
;
4278 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4280 if (get_frame_type (frame
) != INLINE_FRAME
)
4283 sal
= find_frame_sal (frame
);
4284 sym
= get_frame_function (frame
);
4287 fn
= sym
->print_name ();
4290 && function_name_is_marked_for_skip (fn
, sal
))
4297 /* If the event thread has the stop requested flag set, pretend it
4298 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4302 handle_stop_requested (struct execution_control_state
*ecs
)
4304 if (ecs
->event_thread
->stop_requested
)
4306 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4307 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4308 handle_signal_stop (ecs
);
4314 /* Auxiliary function that handles syscall entry/return events.
4315 It returns true if the inferior should keep going (and GDB
4316 should ignore the event), or false if the event deserves to be
4320 handle_syscall_event (struct execution_control_state
*ecs
)
4322 struct regcache
*regcache
;
4325 context_switch (ecs
);
4327 regcache
= get_thread_regcache (ecs
->event_thread
);
4328 syscall_number
= ecs
->ws
.value
.syscall_number
;
4329 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4331 if (catch_syscall_enabled () > 0
4332 && catching_syscall_number (syscall_number
) > 0)
4334 infrun_debug_printf ("syscall number=%d", syscall_number
);
4336 ecs
->event_thread
->control
.stop_bpstat
4337 = bpstat_stop_status (regcache
->aspace (),
4338 ecs
->event_thread
->suspend
.stop_pc
,
4339 ecs
->event_thread
, &ecs
->ws
);
4341 if (handle_stop_requested (ecs
))
4344 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4346 /* Catchpoint hit. */
4351 if (handle_stop_requested (ecs
))
4354 /* If no catchpoint triggered for this, then keep going. */
4360 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4363 fill_in_stop_func (struct gdbarch
*gdbarch
,
4364 struct execution_control_state
*ecs
)
4366 if (!ecs
->stop_func_filled_in
)
4369 const general_symbol_info
*gsi
;
4371 /* Don't care about return value; stop_func_start and stop_func_name
4372 will both be 0 if it doesn't work. */
4373 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4375 &ecs
->stop_func_start
,
4376 &ecs
->stop_func_end
,
4378 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4380 /* The call to find_pc_partial_function, above, will set
4381 stop_func_start and stop_func_end to the start and end
4382 of the range containing the stop pc. If this range
4383 contains the entry pc for the block (which is always the
4384 case for contiguous blocks), advance stop_func_start past
4385 the function's start offset and entrypoint. Note that
4386 stop_func_start is NOT advanced when in a range of a
4387 non-contiguous block that does not contain the entry pc. */
4388 if (block
!= nullptr
4389 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4390 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4392 ecs
->stop_func_start
4393 += gdbarch_deprecated_function_start_offset (gdbarch
);
4395 if (gdbarch_skip_entrypoint_p (gdbarch
))
4396 ecs
->stop_func_start
4397 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4400 ecs
->stop_func_filled_in
= 1;
4405 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4407 static enum stop_kind
4408 get_inferior_stop_soon (execution_control_state
*ecs
)
4410 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4412 gdb_assert (inf
!= NULL
);
4413 return inf
->control
.stop_soon
;
4416 /* Poll for one event out of the current target. Store the resulting
4417 waitstatus in WS, and return the event ptid. Does not block. */
4420 poll_one_curr_target (struct target_waitstatus
*ws
)
4424 overlay_cache_invalid
= 1;
4426 /* Flush target cache before starting to handle each event.
4427 Target was running and cache could be stale. This is just a
4428 heuristic. Running threads may modify target memory, but we
4429 don't get any event. */
4430 target_dcache_invalidate ();
4432 if (deprecated_target_wait_hook
)
4433 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4435 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4438 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4443 /* An event reported by wait_one. */
4445 struct wait_one_event
4447 /* The target the event came out of. */
4448 process_stratum_target
*target
;
4450 /* The PTID the event was for. */
4453 /* The waitstatus. */
4454 target_waitstatus ws
;
4457 /* Wait for one event out of any target. */
4459 static wait_one_event
4464 for (inferior
*inf
: all_inferiors ())
4466 process_stratum_target
*target
= inf
->process_target ();
4468 || !target
->is_async_p ()
4469 || !target
->threads_executing
)
4472 switch_to_inferior_no_thread (inf
);
4474 wait_one_event event
;
4475 event
.target
= target
;
4476 event
.ptid
= poll_one_curr_target (&event
.ws
);
4478 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4480 /* If nothing is resumed, remove the target from the
4484 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4488 /* Block waiting for some event. */
4495 for (inferior
*inf
: all_inferiors ())
4497 process_stratum_target
*target
= inf
->process_target ();
4499 || !target
->is_async_p ()
4500 || !target
->threads_executing
)
4503 int fd
= target
->async_wait_fd ();
4504 FD_SET (fd
, &readfds
);
4511 /* No waitable targets left. All must be stopped. */
4512 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4517 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4523 perror_with_name ("interruptible_select");
4528 /* Save the thread's event and stop reason to process it later. */
4531 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4533 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4534 target_waitstatus_to_string (ws
).c_str (),
4539 /* Record for later. */
4540 tp
->suspend
.waitstatus
= *ws
;
4541 tp
->suspend
.waitstatus_pending_p
= 1;
4543 struct regcache
*regcache
= get_thread_regcache (tp
);
4544 const address_space
*aspace
= regcache
->aspace ();
4546 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4547 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4549 CORE_ADDR pc
= regcache_read_pc (regcache
);
4551 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4553 scoped_restore_current_thread restore_thread
;
4554 switch_to_thread (tp
);
4556 if (target_stopped_by_watchpoint ())
4558 tp
->suspend
.stop_reason
4559 = TARGET_STOPPED_BY_WATCHPOINT
;
4561 else if (target_supports_stopped_by_sw_breakpoint ()
4562 && target_stopped_by_sw_breakpoint ())
4564 tp
->suspend
.stop_reason
4565 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4567 else if (target_supports_stopped_by_hw_breakpoint ()
4568 && target_stopped_by_hw_breakpoint ())
4570 tp
->suspend
.stop_reason
4571 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4573 else if (!target_supports_stopped_by_hw_breakpoint ()
4574 && hardware_breakpoint_inserted_here_p (aspace
,
4577 tp
->suspend
.stop_reason
4578 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4580 else if (!target_supports_stopped_by_sw_breakpoint ()
4581 && software_breakpoint_inserted_here_p (aspace
,
4584 tp
->suspend
.stop_reason
4585 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4587 else if (!thread_has_single_step_breakpoints_set (tp
)
4588 && currently_stepping (tp
))
4590 tp
->suspend
.stop_reason
4591 = TARGET_STOPPED_BY_SINGLE_STEP
;
4596 /* Mark the non-executing threads accordingly. In all-stop, all
4597 threads of all processes are stopped when we get any event
4598 reported. In non-stop mode, only the event thread stops. */
4601 mark_non_executing_threads (process_stratum_target
*target
,
4603 struct target_waitstatus ws
)
4607 if (!target_is_non_stop_p ())
4608 mark_ptid
= minus_one_ptid
;
4609 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4610 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4612 /* If we're handling a process exit in non-stop mode, even
4613 though threads haven't been deleted yet, one would think
4614 that there is nothing to do, as threads of the dead process
4615 will be soon deleted, and threads of any other process were
4616 left running. However, on some targets, threads survive a
4617 process exit event. E.g., for the "checkpoint" command,
4618 when the current checkpoint/fork exits, linux-fork.c
4619 automatically switches to another fork from within
4620 target_mourn_inferior, by associating the same
4621 inferior/thread to another fork. We haven't mourned yet at
4622 this point, but we must mark any threads left in the
4623 process as not-executing so that finish_thread_state marks
4624 them stopped (in the user's perspective) if/when we present
4625 the stop to the user. */
4626 mark_ptid
= ptid_t (event_ptid
.pid ());
4629 mark_ptid
= event_ptid
;
4631 set_executing (target
, mark_ptid
, false);
4633 /* Likewise the resumed flag. */
4634 set_resumed (target
, mark_ptid
, false);
4640 stop_all_threads (void)
4642 /* We may need multiple passes to discover all threads. */
4646 gdb_assert (exists_non_stop_target ());
4648 infrun_debug_printf ("starting");
4650 scoped_restore_current_thread restore_thread
;
4652 /* Enable thread events of all targets. */
4653 for (auto *target
: all_non_exited_process_targets ())
4655 switch_to_target_no_thread (target
);
4656 target_thread_events (true);
4661 /* Disable thread events of all targets. */
4662 for (auto *target
: all_non_exited_process_targets ())
4664 switch_to_target_no_thread (target
);
4665 target_thread_events (false);
4668 /* Use infrun_debug_printf_1 directly to get a meaningful function
4671 infrun_debug_printf_1 ("stop_all_threads", "done");
4674 /* Request threads to stop, and then wait for the stops. Because
4675 threads we already know about can spawn more threads while we're
4676 trying to stop them, and we only learn about new threads when we
4677 update the thread list, do this in a loop, and keep iterating
4678 until two passes find no threads that need to be stopped. */
4679 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4681 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4684 int waits_needed
= 0;
4686 for (auto *target
: all_non_exited_process_targets ())
4688 switch_to_target_no_thread (target
);
4689 update_thread_list ();
4692 /* Go through all threads looking for threads that we need
4693 to tell the target to stop. */
4694 for (thread_info
*t
: all_non_exited_threads ())
4696 /* For a single-target setting with an all-stop target,
4697 we would not even arrive here. For a multi-target
4698 setting, until GDB is able to handle a mixture of
4699 all-stop and non-stop targets, simply skip all-stop
4700 targets' threads. This should be fine due to the
4701 protection of 'check_multi_target_resumption'. */
4703 switch_to_thread_no_regs (t
);
4704 if (!target_is_non_stop_p ())
4709 /* If already stopping, don't request a stop again.
4710 We just haven't seen the notification yet. */
4711 if (!t
->stop_requested
)
4713 infrun_debug_printf (" %s executing, need stop",
4714 target_pid_to_str (t
->ptid
).c_str ());
4715 target_stop (t
->ptid
);
4716 t
->stop_requested
= 1;
4720 infrun_debug_printf (" %s executing, already stopping",
4721 target_pid_to_str (t
->ptid
).c_str ());
4724 if (t
->stop_requested
)
4729 infrun_debug_printf (" %s not executing",
4730 target_pid_to_str (t
->ptid
).c_str ());
4732 /* The thread may be not executing, but still be
4733 resumed with a pending status to process. */
4738 if (waits_needed
== 0)
4741 /* If we find new threads on the second iteration, restart
4742 over. We want to see two iterations in a row with all
4747 for (int i
= 0; i
< waits_needed
; i
++)
4749 wait_one_event event
= wait_one ();
4752 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4753 target_pid_to_str (event
.ptid
).c_str ());
4755 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4757 /* All resumed threads exited. */
4760 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4761 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4762 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4764 /* One thread/process exited/signalled. */
4766 thread_info
*t
= nullptr;
4768 /* The target may have reported just a pid. If so, try
4769 the first non-exited thread. */
4770 if (event
.ptid
.is_pid ())
4772 int pid
= event
.ptid
.pid ();
4773 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4774 for (thread_info
*tp
: inf
->non_exited_threads ())
4780 /* If there is no available thread, the event would
4781 have to be appended to a per-inferior event list,
4782 which does not exist (and if it did, we'd have
4783 to adjust run control command to be able to
4784 resume such an inferior). We assert here instead
4785 of going into an infinite loop. */
4786 gdb_assert (t
!= nullptr);
4789 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4793 t
= find_thread_ptid (event
.target
, event
.ptid
);
4794 /* Check if this is the first time we see this thread.
4795 Don't bother adding if it individually exited. */
4797 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4798 t
= add_thread (event
.target
, event
.ptid
);
4803 /* Set the threads as non-executing to avoid
4804 another stop attempt on them. */
4805 switch_to_thread_no_regs (t
);
4806 mark_non_executing_threads (event
.target
, event
.ptid
,
4808 save_waitstatus (t
, &event
.ws
);
4809 t
->stop_requested
= false;
4814 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4816 t
= add_thread (event
.target
, event
.ptid
);
4818 t
->stop_requested
= 0;
4821 t
->control
.may_range_step
= 0;
4823 /* This may be the first time we see the inferior report
4825 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4826 if (inf
->needs_setup
)
4828 switch_to_thread_no_regs (t
);
4832 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4833 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4835 /* We caught the event that we intended to catch, so
4836 there's no event pending. */
4837 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4838 t
->suspend
.waitstatus_pending_p
= 0;
4840 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4842 /* Add it back to the step-over queue. */
4844 ("displaced-step of %s canceled: adding back to "
4845 "the step-over queue",
4846 target_pid_to_str (t
->ptid
).c_str ());
4848 t
->control
.trap_expected
= 0;
4849 thread_step_over_chain_enqueue (t
);
4854 enum gdb_signal sig
;
4855 struct regcache
*regcache
;
4858 ("target_wait %s, saving status for %d.%ld.%ld",
4859 target_waitstatus_to_string (&event
.ws
).c_str (),
4860 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4862 /* Record for later. */
4863 save_waitstatus (t
, &event
.ws
);
4865 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4866 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4868 if (displaced_step_fixup (t
, sig
) < 0)
4870 /* Add it back to the step-over queue. */
4871 t
->control
.trap_expected
= 0;
4872 thread_step_over_chain_enqueue (t
);
4875 regcache
= get_thread_regcache (t
);
4876 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4878 infrun_debug_printf ("saved stop_pc=%s for %s "
4879 "(currently_stepping=%d)",
4880 paddress (target_gdbarch (),
4881 t
->suspend
.stop_pc
),
4882 target_pid_to_str (t
->ptid
).c_str (),
4883 currently_stepping (t
));
4891 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4894 handle_no_resumed (struct execution_control_state
*ecs
)
4896 if (target_can_async_p ())
4898 bool any_sync
= false;
4900 for (ui
*ui
: all_uis ())
4902 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4910 /* There were no unwaited-for children left in the target, but,
4911 we're not synchronously waiting for events either. Just
4914 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4915 prepare_to_wait (ecs
);
4920 /* Otherwise, if we were running a synchronous execution command, we
4921 may need to cancel it and give the user back the terminal.
4923 In non-stop mode, the target can't tell whether we've already
4924 consumed previous stop events, so it can end up sending us a
4925 no-resumed event like so:
4927 #0 - thread 1 is left stopped
4929 #1 - thread 2 is resumed and hits breakpoint
4930 -> TARGET_WAITKIND_STOPPED
4932 #2 - thread 3 is resumed and exits
4933 this is the last resumed thread, so
4934 -> TARGET_WAITKIND_NO_RESUMED
4936 #3 - gdb processes stop for thread 2 and decides to re-resume
4939 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4940 thread 2 is now resumed, so the event should be ignored.
4942 IOW, if the stop for thread 2 doesn't end a foreground command,
4943 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4944 event. But it could be that the event meant that thread 2 itself
4945 (or whatever other thread was the last resumed thread) exited.
4947 To address this we refresh the thread list and check whether we
4948 have resumed threads _now_. In the example above, this removes
4949 thread 3 from the thread list. If thread 2 was re-resumed, we
4950 ignore this event. If we find no thread resumed, then we cancel
4951 the synchronous command and show "no unwaited-for " to the
4954 inferior
*curr_inf
= current_inferior ();
4956 scoped_restore_current_thread restore_thread
;
4958 for (auto *target
: all_non_exited_process_targets ())
4960 switch_to_target_no_thread (target
);
4961 update_thread_list ();
4966 - the current target has no thread executing, and
4967 - the current inferior is native, and
4968 - the current inferior is the one which has the terminal, and
4971 then a Ctrl-C from this point on would remain stuck in the
4972 kernel, until a thread resumes and dequeues it. That would
4973 result in the GDB CLI not reacting to Ctrl-C, not able to
4974 interrupt the program. To address this, if the current inferior
4975 no longer has any thread executing, we give the terminal to some
4976 other inferior that has at least one thread executing. */
4977 bool swap_terminal
= true;
4979 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4980 whether to report it to the user. */
4981 bool ignore_event
= false;
4983 for (thread_info
*thread
: all_non_exited_threads ())
4985 if (swap_terminal
&& thread
->executing
)
4987 if (thread
->inf
!= curr_inf
)
4989 target_terminal::ours ();
4991 switch_to_thread (thread
);
4992 target_terminal::inferior ();
4994 swap_terminal
= false;
4998 && (thread
->executing
4999 || thread
->suspend
.waitstatus_pending_p
))
5001 /* Either there were no unwaited-for children left in the
5002 target at some point, but there are now, or some target
5003 other than the eventing one has unwaited-for children
5004 left. Just ignore. */
5005 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
5006 "(ignoring: found resumed)");
5008 ignore_event
= true;
5011 if (ignore_event
&& !swap_terminal
)
5017 switch_to_inferior_no_thread (curr_inf
);
5018 prepare_to_wait (ecs
);
5022 /* Go ahead and report the event. */
5026 /* Given an execution control state that has been freshly filled in by
5027 an event from the inferior, figure out what it means and take
5030 The alternatives are:
5032 1) stop_waiting and return; to really stop and return to the
5035 2) keep_going and return; to wait for the next event (set
5036 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5040 handle_inferior_event (struct execution_control_state
*ecs
)
5042 /* Make sure that all temporary struct value objects that were
5043 created during the handling of the event get deleted at the
5045 scoped_value_mark free_values
;
5047 enum stop_kind stop_soon
;
5049 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5051 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5053 /* We had an event in the inferior, but we are not interested in
5054 handling it at this level. The lower layers have already
5055 done what needs to be done, if anything.
5057 One of the possible circumstances for this is when the
5058 inferior produces output for the console. The inferior has
5059 not stopped, and we are ignoring the event. Another possible
5060 circumstance is any event which the lower level knows will be
5061 reported multiple times without an intervening resume. */
5062 prepare_to_wait (ecs
);
5066 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5068 prepare_to_wait (ecs
);
5072 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5073 && handle_no_resumed (ecs
))
5076 /* Cache the last target/ptid/waitstatus. */
5077 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5079 /* Always clear state belonging to the previous time we stopped. */
5080 stop_stack_dummy
= STOP_NONE
;
5082 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5084 /* No unwaited-for children left. IOW, all resumed children
5086 stop_print_frame
= false;
5091 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5092 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5094 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5095 /* If it's a new thread, add it to the thread database. */
5096 if (ecs
->event_thread
== NULL
)
5097 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5099 /* Disable range stepping. If the next step request could use a
5100 range, this will be end up re-enabled then. */
5101 ecs
->event_thread
->control
.may_range_step
= 0;
5104 /* Dependent on valid ECS->EVENT_THREAD. */
5105 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5107 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5108 reinit_frame_cache ();
5110 breakpoint_retire_moribund ();
5112 /* First, distinguish signals caused by the debugger from signals
5113 that have to do with the program's own actions. Note that
5114 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5115 on the operating system version. Here we detect when a SIGILL or
5116 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5117 something similar for SIGSEGV, since a SIGSEGV will be generated
5118 when we're trying to execute a breakpoint instruction on a
5119 non-executable stack. This happens for call dummy breakpoints
5120 for architectures like SPARC that place call dummies on the
5122 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5123 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5124 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5125 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5127 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5129 if (breakpoint_inserted_here_p (regcache
->aspace (),
5130 regcache_read_pc (regcache
)))
5132 infrun_debug_printf ("Treating signal as SIGTRAP");
5133 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5137 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5139 switch (ecs
->ws
.kind
)
5141 case TARGET_WAITKIND_LOADED
:
5142 context_switch (ecs
);
5143 /* Ignore gracefully during startup of the inferior, as it might
5144 be the shell which has just loaded some objects, otherwise
5145 add the symbols for the newly loaded objects. Also ignore at
5146 the beginning of an attach or remote session; we will query
5147 the full list of libraries once the connection is
5150 stop_soon
= get_inferior_stop_soon (ecs
);
5151 if (stop_soon
== NO_STOP_QUIETLY
)
5153 struct regcache
*regcache
;
5155 regcache
= get_thread_regcache (ecs
->event_thread
);
5157 handle_solib_event ();
5159 ecs
->event_thread
->control
.stop_bpstat
5160 = bpstat_stop_status (regcache
->aspace (),
5161 ecs
->event_thread
->suspend
.stop_pc
,
5162 ecs
->event_thread
, &ecs
->ws
);
5164 if (handle_stop_requested (ecs
))
5167 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5169 /* A catchpoint triggered. */
5170 process_event_stop_test (ecs
);
5174 /* If requested, stop when the dynamic linker notifies
5175 gdb of events. This allows the user to get control
5176 and place breakpoints in initializer routines for
5177 dynamically loaded objects (among other things). */
5178 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5179 if (stop_on_solib_events
)
5181 /* Make sure we print "Stopped due to solib-event" in
5183 stop_print_frame
= true;
5190 /* If we are skipping through a shell, or through shared library
5191 loading that we aren't interested in, resume the program. If
5192 we're running the program normally, also resume. */
5193 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5195 /* Loading of shared libraries might have changed breakpoint
5196 addresses. Make sure new breakpoints are inserted. */
5197 if (stop_soon
== NO_STOP_QUIETLY
)
5198 insert_breakpoints ();
5199 resume (GDB_SIGNAL_0
);
5200 prepare_to_wait (ecs
);
5204 /* But stop if we're attaching or setting up a remote
5206 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5207 || stop_soon
== STOP_QUIETLY_REMOTE
)
5209 infrun_debug_printf ("quietly stopped");
5214 internal_error (__FILE__
, __LINE__
,
5215 _("unhandled stop_soon: %d"), (int) stop_soon
);
5217 case TARGET_WAITKIND_SPURIOUS
:
5218 if (handle_stop_requested (ecs
))
5220 context_switch (ecs
);
5221 resume (GDB_SIGNAL_0
);
5222 prepare_to_wait (ecs
);
5225 case TARGET_WAITKIND_THREAD_CREATED
:
5226 if (handle_stop_requested (ecs
))
5228 context_switch (ecs
);
5229 if (!switch_back_to_stepped_thread (ecs
))
5233 case TARGET_WAITKIND_EXITED
:
5234 case TARGET_WAITKIND_SIGNALLED
:
5236 /* Depending on the system, ecs->ptid may point to a thread or
5237 to a process. On some targets, target_mourn_inferior may
5238 need to have access to the just-exited thread. That is the
5239 case of GNU/Linux's "checkpoint" support, for example.
5240 Call the switch_to_xxx routine as appropriate. */
5241 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5243 switch_to_thread (thr
);
5246 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5247 switch_to_inferior_no_thread (inf
);
5250 handle_vfork_child_exec_or_exit (0);
5251 target_terminal::ours (); /* Must do this before mourn anyway. */
5253 /* Clearing any previous state of convenience variables. */
5254 clear_exit_convenience_vars ();
5256 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5258 /* Record the exit code in the convenience variable $_exitcode, so
5259 that the user can inspect this again later. */
5260 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5261 (LONGEST
) ecs
->ws
.value
.integer
);
5263 /* Also record this in the inferior itself. */
5264 current_inferior ()->has_exit_code
= 1;
5265 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5267 /* Support the --return-child-result option. */
5268 return_child_result_value
= ecs
->ws
.value
.integer
;
5270 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5274 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5276 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5278 /* Set the value of the internal variable $_exitsignal,
5279 which holds the signal uncaught by the inferior. */
5280 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5281 gdbarch_gdb_signal_to_target (gdbarch
,
5282 ecs
->ws
.value
.sig
));
5286 /* We don't have access to the target's method used for
5287 converting between signal numbers (GDB's internal
5288 representation <-> target's representation).
5289 Therefore, we cannot do a good job at displaying this
5290 information to the user. It's better to just warn
5291 her about it (if infrun debugging is enabled), and
5293 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5297 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5300 gdb_flush (gdb_stdout
);
5301 target_mourn_inferior (inferior_ptid
);
5302 stop_print_frame
= false;
5306 case TARGET_WAITKIND_FORKED
:
5307 case TARGET_WAITKIND_VFORKED
:
5308 /* Check whether the inferior is displaced stepping. */
5310 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5311 struct gdbarch
*gdbarch
= regcache
->arch ();
5313 /* If checking displaced stepping is supported, and thread
5314 ecs->ptid is displaced stepping. */
5315 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5317 struct inferior
*parent_inf
5318 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5319 struct regcache
*child_regcache
;
5320 CORE_ADDR parent_pc
;
5322 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5324 struct displaced_step_inferior_state
*displaced
5325 = get_displaced_stepping_state (parent_inf
);
5327 /* Restore scratch pad for child process. */
5328 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5331 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5332 indicating that the displaced stepping of syscall instruction
5333 has been done. Perform cleanup for parent process here. Note
5334 that this operation also cleans up the child process for vfork,
5335 because their pages are shared. */
5336 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5337 /* Start a new step-over in another thread if there's one
5341 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5342 the child's PC is also within the scratchpad. Set the child's PC
5343 to the parent's PC value, which has already been fixed up.
5344 FIXME: we use the parent's aspace here, although we're touching
5345 the child, because the child hasn't been added to the inferior
5346 list yet at this point. */
5349 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5350 ecs
->ws
.value
.related_pid
,
5352 parent_inf
->aspace
);
5353 /* Read PC value of parent process. */
5354 parent_pc
= regcache_read_pc (regcache
);
5356 if (debug_displaced
)
5357 fprintf_unfiltered (gdb_stdlog
,
5358 "displaced: write child pc from %s to %s\n",
5360 regcache_read_pc (child_regcache
)),
5361 paddress (gdbarch
, parent_pc
));
5363 regcache_write_pc (child_regcache
, parent_pc
);
5367 context_switch (ecs
);
5369 /* Immediately detach breakpoints from the child before there's
5370 any chance of letting the user delete breakpoints from the
5371 breakpoint lists. If we don't do this early, it's easy to
5372 leave left over traps in the child, vis: "break foo; catch
5373 fork; c; <fork>; del; c; <child calls foo>". We only follow
5374 the fork on the last `continue', and by that time the
5375 breakpoint at "foo" is long gone from the breakpoint table.
5376 If we vforked, then we don't need to unpatch here, since both
5377 parent and child are sharing the same memory pages; we'll
5378 need to unpatch at follow/detach time instead to be certain
5379 that new breakpoints added between catchpoint hit time and
5380 vfork follow are detached. */
5381 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5383 /* This won't actually modify the breakpoint list, but will
5384 physically remove the breakpoints from the child. */
5385 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5388 delete_just_stopped_threads_single_step_breakpoints ();
5390 /* In case the event is caught by a catchpoint, remember that
5391 the event is to be followed at the next resume of the thread,
5392 and not immediately. */
5393 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5395 ecs
->event_thread
->suspend
.stop_pc
5396 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5398 ecs
->event_thread
->control
.stop_bpstat
5399 = bpstat_stop_status (get_current_regcache ()->aspace (),
5400 ecs
->event_thread
->suspend
.stop_pc
,
5401 ecs
->event_thread
, &ecs
->ws
);
5403 if (handle_stop_requested (ecs
))
5406 /* If no catchpoint triggered for this, then keep going. Note
5407 that we're interested in knowing the bpstat actually causes a
5408 stop, not just if it may explain the signal. Software
5409 watchpoints, for example, always appear in the bpstat. */
5410 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5413 = (follow_fork_mode_string
== follow_fork_mode_child
);
5415 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5417 process_stratum_target
*targ
5418 = ecs
->event_thread
->inf
->process_target ();
5420 bool should_resume
= follow_fork ();
5422 /* Note that one of these may be an invalid pointer,
5423 depending on detach_fork. */
5424 thread_info
*parent
= ecs
->event_thread
;
5426 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5428 /* At this point, the parent is marked running, and the
5429 child is marked stopped. */
5431 /* If not resuming the parent, mark it stopped. */
5432 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5433 parent
->set_running (false);
5435 /* If resuming the child, mark it running. */
5436 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5437 child
->set_running (true);
5439 /* In non-stop mode, also resume the other branch. */
5440 if (!detach_fork
&& (non_stop
5441 || (sched_multi
&& target_is_non_stop_p ())))
5444 switch_to_thread (parent
);
5446 switch_to_thread (child
);
5448 ecs
->event_thread
= inferior_thread ();
5449 ecs
->ptid
= inferior_ptid
;
5454 switch_to_thread (child
);
5456 switch_to_thread (parent
);
5458 ecs
->event_thread
= inferior_thread ();
5459 ecs
->ptid
= inferior_ptid
;
5467 process_event_stop_test (ecs
);
5470 case TARGET_WAITKIND_VFORK_DONE
:
5471 /* Done with the shared memory region. Re-insert breakpoints in
5472 the parent, and keep going. */
5474 context_switch (ecs
);
5476 current_inferior ()->waiting_for_vfork_done
= 0;
5477 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5479 if (handle_stop_requested (ecs
))
5482 /* This also takes care of reinserting breakpoints in the
5483 previously locked inferior. */
5487 case TARGET_WAITKIND_EXECD
:
5489 /* Note we can't read registers yet (the stop_pc), because we
5490 don't yet know the inferior's post-exec architecture.
5491 'stop_pc' is explicitly read below instead. */
5492 switch_to_thread_no_regs (ecs
->event_thread
);
5494 /* Do whatever is necessary to the parent branch of the vfork. */
5495 handle_vfork_child_exec_or_exit (1);
5497 /* This causes the eventpoints and symbol table to be reset.
5498 Must do this now, before trying to determine whether to
5500 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5502 /* In follow_exec we may have deleted the original thread and
5503 created a new one. Make sure that the event thread is the
5504 execd thread for that case (this is a nop otherwise). */
5505 ecs
->event_thread
= inferior_thread ();
5507 ecs
->event_thread
->suspend
.stop_pc
5508 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5510 ecs
->event_thread
->control
.stop_bpstat
5511 = bpstat_stop_status (get_current_regcache ()->aspace (),
5512 ecs
->event_thread
->suspend
.stop_pc
,
5513 ecs
->event_thread
, &ecs
->ws
);
5515 /* Note that this may be referenced from inside
5516 bpstat_stop_status above, through inferior_has_execd. */
5517 xfree (ecs
->ws
.value
.execd_pathname
);
5518 ecs
->ws
.value
.execd_pathname
= NULL
;
5520 if (handle_stop_requested (ecs
))
5523 /* If no catchpoint triggered for this, then keep going. */
5524 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5526 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5530 process_event_stop_test (ecs
);
5533 /* Be careful not to try to gather much state about a thread
5534 that's in a syscall. It's frequently a losing proposition. */
5535 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5536 /* Getting the current syscall number. */
5537 if (handle_syscall_event (ecs
) == 0)
5538 process_event_stop_test (ecs
);
5541 /* Before examining the threads further, step this thread to
5542 get it entirely out of the syscall. (We get notice of the
5543 event when the thread is just on the verge of exiting a
5544 syscall. Stepping one instruction seems to get it back
5546 case TARGET_WAITKIND_SYSCALL_RETURN
:
5547 if (handle_syscall_event (ecs
) == 0)
5548 process_event_stop_test (ecs
);
5551 case TARGET_WAITKIND_STOPPED
:
5552 handle_signal_stop (ecs
);
5555 case TARGET_WAITKIND_NO_HISTORY
:
5556 /* Reverse execution: target ran out of history info. */
5558 /* Switch to the stopped thread. */
5559 context_switch (ecs
);
5560 infrun_debug_printf ("stopped");
5562 delete_just_stopped_threads_single_step_breakpoints ();
5563 ecs
->event_thread
->suspend
.stop_pc
5564 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5566 if (handle_stop_requested (ecs
))
5569 gdb::observers::no_history
.notify ();
5575 /* Restart threads back to what they were trying to do back when we
5576 paused them for an in-line step-over. The EVENT_THREAD thread is
5580 restart_threads (struct thread_info
*event_thread
)
5582 /* In case the instruction just stepped spawned a new thread. */
5583 update_thread_list ();
5585 for (thread_info
*tp
: all_non_exited_threads ())
5587 switch_to_thread_no_regs (tp
);
5589 if (tp
== event_thread
)
5591 infrun_debug_printf ("restart threads: [%s] is event thread",
5592 target_pid_to_str (tp
->ptid
).c_str ());
5596 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5598 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5599 target_pid_to_str (tp
->ptid
).c_str ());
5605 infrun_debug_printf ("restart threads: [%s] resumed",
5606 target_pid_to_str (tp
->ptid
).c_str ());
5607 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5611 if (thread_is_in_step_over_chain (tp
))
5613 infrun_debug_printf ("restart threads: [%s] needs step-over",
5614 target_pid_to_str (tp
->ptid
).c_str ());
5615 gdb_assert (!tp
->resumed
);
5620 if (tp
->suspend
.waitstatus_pending_p
)
5622 infrun_debug_printf ("restart threads: [%s] has pending status",
5623 target_pid_to_str (tp
->ptid
).c_str ());
5628 gdb_assert (!tp
->stop_requested
);
5630 /* If some thread needs to start a step-over at this point, it
5631 should still be in the step-over queue, and thus skipped
5633 if (thread_still_needs_step_over (tp
))
5635 internal_error (__FILE__
, __LINE__
,
5636 "thread [%s] needs a step-over, but not in "
5637 "step-over queue\n",
5638 target_pid_to_str (tp
->ptid
).c_str ());
5641 if (currently_stepping (tp
))
5643 infrun_debug_printf ("restart threads: [%s] was stepping",
5644 target_pid_to_str (tp
->ptid
).c_str ());
5645 keep_going_stepped_thread (tp
);
5649 struct execution_control_state ecss
;
5650 struct execution_control_state
*ecs
= &ecss
;
5652 infrun_debug_printf ("restart threads: [%s] continuing",
5653 target_pid_to_str (tp
->ptid
).c_str ());
5654 reset_ecs (ecs
, tp
);
5655 switch_to_thread (tp
);
5656 keep_going_pass_signal (ecs
);
5661 /* Callback for iterate_over_threads. Find a resumed thread that has
5662 a pending waitstatus. */
5665 resumed_thread_with_pending_status (struct thread_info
*tp
,
5669 && tp
->suspend
.waitstatus_pending_p
);
5672 /* Called when we get an event that may finish an in-line or
5673 out-of-line (displaced stepping) step-over started previously.
5674 Return true if the event is processed and we should go back to the
5675 event loop; false if the caller should continue processing the
5679 finish_step_over (struct execution_control_state
*ecs
)
5681 displaced_step_fixup (ecs
->event_thread
,
5682 ecs
->event_thread
->suspend
.stop_signal
);
5684 bool had_step_over_info
= step_over_info_valid_p ();
5686 if (had_step_over_info
)
5688 /* If we're stepping over a breakpoint with all threads locked,
5689 then only the thread that was stepped should be reporting
5691 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5693 clear_step_over_info ();
5696 if (!target_is_non_stop_p ())
5699 /* Start a new step-over in another thread if there's one that
5703 /* If we were stepping over a breakpoint before, and haven't started
5704 a new in-line step-over sequence, then restart all other threads
5705 (except the event thread). We can't do this in all-stop, as then
5706 e.g., we wouldn't be able to issue any other remote packet until
5707 these other threads stop. */
5708 if (had_step_over_info
&& !step_over_info_valid_p ())
5710 struct thread_info
*pending
;
5712 /* If we only have threads with pending statuses, the restart
5713 below won't restart any thread and so nothing re-inserts the
5714 breakpoint we just stepped over. But we need it inserted
5715 when we later process the pending events, otherwise if
5716 another thread has a pending event for this breakpoint too,
5717 we'd discard its event (because the breakpoint that
5718 originally caused the event was no longer inserted). */
5719 context_switch (ecs
);
5720 insert_breakpoints ();
5722 restart_threads (ecs
->event_thread
);
5724 /* If we have events pending, go through handle_inferior_event
5725 again, picking up a pending event at random. This avoids
5726 thread starvation. */
5728 /* But not if we just stepped over a watchpoint in order to let
5729 the instruction execute so we can evaluate its expression.
5730 The set of watchpoints that triggered is recorded in the
5731 breakpoint objects themselves (see bp->watchpoint_triggered).
5732 If we processed another event first, that other event could
5733 clobber this info. */
5734 if (ecs
->event_thread
->stepping_over_watchpoint
)
5737 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5739 if (pending
!= NULL
)
5741 struct thread_info
*tp
= ecs
->event_thread
;
5742 struct regcache
*regcache
;
5744 infrun_debug_printf ("found resumed threads with "
5745 "pending events, saving status");
5747 gdb_assert (pending
!= tp
);
5749 /* Record the event thread's event for later. */
5750 save_waitstatus (tp
, &ecs
->ws
);
5751 /* This was cleared early, by handle_inferior_event. Set it
5752 so this pending event is considered by
5756 gdb_assert (!tp
->executing
);
5758 regcache
= get_thread_regcache (tp
);
5759 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5761 infrun_debug_printf ("saved stop_pc=%s for %s "
5762 "(currently_stepping=%d)",
5763 paddress (target_gdbarch (),
5764 tp
->suspend
.stop_pc
),
5765 target_pid_to_str (tp
->ptid
).c_str (),
5766 currently_stepping (tp
));
5768 /* This in-line step-over finished; clear this so we won't
5769 start a new one. This is what handle_signal_stop would
5770 do, if we returned false. */
5771 tp
->stepping_over_breakpoint
= 0;
5773 /* Wake up the event loop again. */
5774 mark_async_event_handler (infrun_async_inferior_event_token
);
5776 prepare_to_wait (ecs
);
5784 /* Come here when the program has stopped with a signal. */
5787 handle_signal_stop (struct execution_control_state
*ecs
)
5789 struct frame_info
*frame
;
5790 struct gdbarch
*gdbarch
;
5791 int stopped_by_watchpoint
;
5792 enum stop_kind stop_soon
;
5795 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5797 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5799 /* Do we need to clean up the state of a thread that has
5800 completed a displaced single-step? (Doing so usually affects
5801 the PC, so do it here, before we set stop_pc.) */
5802 if (finish_step_over (ecs
))
5805 /* If we either finished a single-step or hit a breakpoint, but
5806 the user wanted this thread to be stopped, pretend we got a
5807 SIG0 (generic unsignaled stop). */
5808 if (ecs
->event_thread
->stop_requested
5809 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5810 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5812 ecs
->event_thread
->suspend
.stop_pc
5813 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5817 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5818 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5820 switch_to_thread (ecs
->event_thread
);
5822 infrun_debug_printf ("stop_pc=%s",
5823 paddress (reg_gdbarch
,
5824 ecs
->event_thread
->suspend
.stop_pc
));
5825 if (target_stopped_by_watchpoint ())
5829 infrun_debug_printf ("stopped by watchpoint");
5831 if (target_stopped_data_address (current_top_target (), &addr
))
5832 infrun_debug_printf ("stopped data address=%s",
5833 paddress (reg_gdbarch
, addr
));
5835 infrun_debug_printf ("(no data address available)");
5839 /* This is originated from start_remote(), start_inferior() and
5840 shared libraries hook functions. */
5841 stop_soon
= get_inferior_stop_soon (ecs
);
5842 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5844 context_switch (ecs
);
5845 infrun_debug_printf ("quietly stopped");
5846 stop_print_frame
= true;
5851 /* This originates from attach_command(). We need to overwrite
5852 the stop_signal here, because some kernels don't ignore a
5853 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5854 See more comments in inferior.h. On the other hand, if we
5855 get a non-SIGSTOP, report it to the user - assume the backend
5856 will handle the SIGSTOP if it should show up later.
5858 Also consider that the attach is complete when we see a
5859 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5860 target extended-remote report it instead of a SIGSTOP
5861 (e.g. gdbserver). We already rely on SIGTRAP being our
5862 signal, so this is no exception.
5864 Also consider that the attach is complete when we see a
5865 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5866 the target to stop all threads of the inferior, in case the
5867 low level attach operation doesn't stop them implicitly. If
5868 they weren't stopped implicitly, then the stub will report a
5869 GDB_SIGNAL_0, meaning: stopped for no particular reason
5870 other than GDB's request. */
5871 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5872 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5873 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5874 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5876 stop_print_frame
= true;
5878 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5882 /* See if something interesting happened to the non-current thread. If
5883 so, then switch to that thread. */
5884 if (ecs
->ptid
!= inferior_ptid
)
5886 infrun_debug_printf ("context switch");
5888 context_switch (ecs
);
5890 if (deprecated_context_hook
)
5891 deprecated_context_hook (ecs
->event_thread
->global_num
);
5894 /* At this point, get hold of the now-current thread's frame. */
5895 frame
= get_current_frame ();
5896 gdbarch
= get_frame_arch (frame
);
5898 /* Pull the single step breakpoints out of the target. */
5899 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5901 struct regcache
*regcache
;
5904 regcache
= get_thread_regcache (ecs
->event_thread
);
5905 const address_space
*aspace
= regcache
->aspace ();
5907 pc
= regcache_read_pc (regcache
);
5909 /* However, before doing so, if this single-step breakpoint was
5910 actually for another thread, set this thread up for moving
5912 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5915 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5917 infrun_debug_printf ("[%s] hit another thread's single-step "
5919 target_pid_to_str (ecs
->ptid
).c_str ());
5920 ecs
->hit_singlestep_breakpoint
= 1;
5925 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5926 target_pid_to_str (ecs
->ptid
).c_str ());
5929 delete_just_stopped_threads_single_step_breakpoints ();
5931 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5932 && ecs
->event_thread
->control
.trap_expected
5933 && ecs
->event_thread
->stepping_over_watchpoint
)
5934 stopped_by_watchpoint
= 0;
5936 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5938 /* If necessary, step over this watchpoint. We'll be back to display
5940 if (stopped_by_watchpoint
5941 && (target_have_steppable_watchpoint ()
5942 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5944 /* At this point, we are stopped at an instruction which has
5945 attempted to write to a piece of memory under control of
5946 a watchpoint. The instruction hasn't actually executed
5947 yet. If we were to evaluate the watchpoint expression
5948 now, we would get the old value, and therefore no change
5949 would seem to have occurred.
5951 In order to make watchpoints work `right', we really need
5952 to complete the memory write, and then evaluate the
5953 watchpoint expression. We do this by single-stepping the
5956 It may not be necessary to disable the watchpoint to step over
5957 it. For example, the PA can (with some kernel cooperation)
5958 single step over a watchpoint without disabling the watchpoint.
5960 It is far more common to need to disable a watchpoint to step
5961 the inferior over it. If we have non-steppable watchpoints,
5962 we must disable the current watchpoint; it's simplest to
5963 disable all watchpoints.
5965 Any breakpoint at PC must also be stepped over -- if there's
5966 one, it will have already triggered before the watchpoint
5967 triggered, and we either already reported it to the user, or
5968 it didn't cause a stop and we called keep_going. In either
5969 case, if there was a breakpoint at PC, we must be trying to
5971 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5976 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5977 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5978 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5979 ecs
->event_thread
->control
.stop_step
= 0;
5980 stop_print_frame
= true;
5981 stopped_by_random_signal
= 0;
5982 bpstat stop_chain
= NULL
;
5984 /* Hide inlined functions starting here, unless we just performed stepi or
5985 nexti. After stepi and nexti, always show the innermost frame (not any
5986 inline function call sites). */
5987 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5989 const address_space
*aspace
5990 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5992 /* skip_inline_frames is expensive, so we avoid it if we can
5993 determine that the address is one where functions cannot have
5994 been inlined. This improves performance with inferiors that
5995 load a lot of shared libraries, because the solib event
5996 breakpoint is defined as the address of a function (i.e. not
5997 inline). Note that we have to check the previous PC as well
5998 as the current one to catch cases when we have just
5999 single-stepped off a breakpoint prior to reinstating it.
6000 Note that we're assuming that the code we single-step to is
6001 not inline, but that's not definitive: there's nothing
6002 preventing the event breakpoint function from containing
6003 inlined code, and the single-step ending up there. If the
6004 user had set a breakpoint on that inlined code, the missing
6005 skip_inline_frames call would break things. Fortunately
6006 that's an extremely unlikely scenario. */
6007 if (!pc_at_non_inline_function (aspace
,
6008 ecs
->event_thread
->suspend
.stop_pc
,
6010 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6011 && ecs
->event_thread
->control
.trap_expected
6012 && pc_at_non_inline_function (aspace
,
6013 ecs
->event_thread
->prev_pc
,
6016 stop_chain
= build_bpstat_chain (aspace
,
6017 ecs
->event_thread
->suspend
.stop_pc
,
6019 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6021 /* Re-fetch current thread's frame in case that invalidated
6023 frame
= get_current_frame ();
6024 gdbarch
= get_frame_arch (frame
);
6028 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6029 && ecs
->event_thread
->control
.trap_expected
6030 && gdbarch_single_step_through_delay_p (gdbarch
)
6031 && currently_stepping (ecs
->event_thread
))
6033 /* We're trying to step off a breakpoint. Turns out that we're
6034 also on an instruction that needs to be stepped multiple
6035 times before it's been fully executing. E.g., architectures
6036 with a delay slot. It needs to be stepped twice, once for
6037 the instruction and once for the delay slot. */
6038 int step_through_delay
6039 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6041 if (step_through_delay
)
6042 infrun_debug_printf ("step through delay");
6044 if (ecs
->event_thread
->control
.step_range_end
== 0
6045 && step_through_delay
)
6047 /* The user issued a continue when stopped at a breakpoint.
6048 Set up for another trap and get out of here. */
6049 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6053 else if (step_through_delay
)
6055 /* The user issued a step when stopped at a breakpoint.
6056 Maybe we should stop, maybe we should not - the delay
6057 slot *might* correspond to a line of source. In any
6058 case, don't decide that here, just set
6059 ecs->stepping_over_breakpoint, making sure we
6060 single-step again before breakpoints are re-inserted. */
6061 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6065 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6066 handles this event. */
6067 ecs
->event_thread
->control
.stop_bpstat
6068 = bpstat_stop_status (get_current_regcache ()->aspace (),
6069 ecs
->event_thread
->suspend
.stop_pc
,
6070 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6072 /* Following in case break condition called a
6074 stop_print_frame
= true;
6076 /* This is where we handle "moribund" watchpoints. Unlike
6077 software breakpoints traps, hardware watchpoint traps are
6078 always distinguishable from random traps. If no high-level
6079 watchpoint is associated with the reported stop data address
6080 anymore, then the bpstat does not explain the signal ---
6081 simply make sure to ignore it if `stopped_by_watchpoint' is
6084 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6085 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6087 && stopped_by_watchpoint
)
6089 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6093 /* NOTE: cagney/2003-03-29: These checks for a random signal
6094 at one stage in the past included checks for an inferior
6095 function call's call dummy's return breakpoint. The original
6096 comment, that went with the test, read:
6098 ``End of a stack dummy. Some systems (e.g. Sony news) give
6099 another signal besides SIGTRAP, so check here as well as
6102 If someone ever tries to get call dummys on a
6103 non-executable stack to work (where the target would stop
6104 with something like a SIGSEGV), then those tests might need
6105 to be re-instated. Given, however, that the tests were only
6106 enabled when momentary breakpoints were not being used, I
6107 suspect that it won't be the case.
6109 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6110 be necessary for call dummies on a non-executable stack on
6113 /* See if the breakpoints module can explain the signal. */
6115 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6116 ecs
->event_thread
->suspend
.stop_signal
);
6118 /* Maybe this was a trap for a software breakpoint that has since
6120 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6122 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6123 ecs
->event_thread
->suspend
.stop_pc
))
6125 struct regcache
*regcache
;
6128 /* Re-adjust PC to what the program would see if GDB was not
6130 regcache
= get_thread_regcache (ecs
->event_thread
);
6131 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6134 gdb::optional
<scoped_restore_tmpl
<int>>
6135 restore_operation_disable
;
6137 if (record_full_is_used ())
6138 restore_operation_disable
.emplace
6139 (record_full_gdb_operation_disable_set ());
6141 regcache_write_pc (regcache
,
6142 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6147 /* A delayed software breakpoint event. Ignore the trap. */
6148 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6153 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6154 has since been removed. */
6155 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6157 /* A delayed hardware breakpoint event. Ignore the trap. */
6158 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6163 /* If not, perhaps stepping/nexting can. */
6165 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6166 && currently_stepping (ecs
->event_thread
));
6168 /* Perhaps the thread hit a single-step breakpoint of _another_
6169 thread. Single-step breakpoints are transparent to the
6170 breakpoints module. */
6172 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6174 /* No? Perhaps we got a moribund watchpoint. */
6176 random_signal
= !stopped_by_watchpoint
;
6178 /* Always stop if the user explicitly requested this thread to
6180 if (ecs
->event_thread
->stop_requested
)
6183 infrun_debug_printf ("user-requested stop");
6186 /* For the program's own signals, act according to
6187 the signal handling tables. */
6191 /* Signal not for debugging purposes. */
6192 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6193 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6195 infrun_debug_printf ("random signal (%s)",
6196 gdb_signal_to_symbol_string (stop_signal
));
6198 stopped_by_random_signal
= 1;
6200 /* Always stop on signals if we're either just gaining control
6201 of the program, or the user explicitly requested this thread
6202 to remain stopped. */
6203 if (stop_soon
!= NO_STOP_QUIETLY
6204 || ecs
->event_thread
->stop_requested
6206 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6212 /* Notify observers the signal has "handle print" set. Note we
6213 returned early above if stopping; normal_stop handles the
6214 printing in that case. */
6215 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6217 /* The signal table tells us to print about this signal. */
6218 target_terminal::ours_for_output ();
6219 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6220 target_terminal::inferior ();
6223 /* Clear the signal if it should not be passed. */
6224 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6225 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6227 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6228 && ecs
->event_thread
->control
.trap_expected
6229 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6231 /* We were just starting a new sequence, attempting to
6232 single-step off of a breakpoint and expecting a SIGTRAP.
6233 Instead this signal arrives. This signal will take us out
6234 of the stepping range so GDB needs to remember to, when
6235 the signal handler returns, resume stepping off that
6237 /* To simplify things, "continue" is forced to use the same
6238 code paths as single-step - set a breakpoint at the
6239 signal return address and then, once hit, step off that
6241 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6243 insert_hp_step_resume_breakpoint_at_frame (frame
);
6244 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6245 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6246 ecs
->event_thread
->control
.trap_expected
= 0;
6248 /* If we were nexting/stepping some other thread, switch to
6249 it, so that we don't continue it, losing control. */
6250 if (!switch_back_to_stepped_thread (ecs
))
6255 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6256 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6258 || ecs
->event_thread
->control
.step_range_end
== 1)
6259 && frame_id_eq (get_stack_frame_id (frame
),
6260 ecs
->event_thread
->control
.step_stack_frame_id
)
6261 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6263 /* The inferior is about to take a signal that will take it
6264 out of the single step range. Set a breakpoint at the
6265 current PC (which is presumably where the signal handler
6266 will eventually return) and then allow the inferior to
6269 Note that this is only needed for a signal delivered
6270 while in the single-step range. Nested signals aren't a
6271 problem as they eventually all return. */
6272 infrun_debug_printf ("signal may take us out of single-step range");
6274 clear_step_over_info ();
6275 insert_hp_step_resume_breakpoint_at_frame (frame
);
6276 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6277 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6278 ecs
->event_thread
->control
.trap_expected
= 0;
6283 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6284 when either there's a nested signal, or when there's a
6285 pending signal enabled just as the signal handler returns
6286 (leaving the inferior at the step-resume-breakpoint without
6287 actually executing it). Either way continue until the
6288 breakpoint is really hit. */
6290 if (!switch_back_to_stepped_thread (ecs
))
6292 infrun_debug_printf ("random signal, keep going");
6299 process_event_stop_test (ecs
);
6302 /* Come here when we've got some debug event / signal we can explain
6303 (IOW, not a random signal), and test whether it should cause a
6304 stop, or whether we should resume the inferior (transparently).
6305 E.g., could be a breakpoint whose condition evaluates false; we
6306 could be still stepping within the line; etc. */
6309 process_event_stop_test (struct execution_control_state
*ecs
)
6311 struct symtab_and_line stop_pc_sal
;
6312 struct frame_info
*frame
;
6313 struct gdbarch
*gdbarch
;
6314 CORE_ADDR jmp_buf_pc
;
6315 struct bpstat_what what
;
6317 /* Handle cases caused by hitting a breakpoint. */
6319 frame
= get_current_frame ();
6320 gdbarch
= get_frame_arch (frame
);
6322 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6324 if (what
.call_dummy
)
6326 stop_stack_dummy
= what
.call_dummy
;
6329 /* A few breakpoint types have callbacks associated (e.g.,
6330 bp_jit_event). Run them now. */
6331 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6333 /* If we hit an internal event that triggers symbol changes, the
6334 current frame will be invalidated within bpstat_what (e.g., if we
6335 hit an internal solib event). Re-fetch it. */
6336 frame
= get_current_frame ();
6337 gdbarch
= get_frame_arch (frame
);
6339 switch (what
.main_action
)
6341 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6342 /* If we hit the breakpoint at longjmp while stepping, we
6343 install a momentary breakpoint at the target of the
6346 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6348 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6350 if (what
.is_longjmp
)
6352 struct value
*arg_value
;
6354 /* If we set the longjmp breakpoint via a SystemTap probe,
6355 then use it to extract the arguments. The destination PC
6356 is the third argument to the probe. */
6357 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6360 jmp_buf_pc
= value_as_address (arg_value
);
6361 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6363 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6364 || !gdbarch_get_longjmp_target (gdbarch
,
6365 frame
, &jmp_buf_pc
))
6367 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6368 "(!gdbarch_get_longjmp_target)");
6373 /* Insert a breakpoint at resume address. */
6374 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6377 check_exception_resume (ecs
, frame
);
6381 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6383 struct frame_info
*init_frame
;
6385 /* There are several cases to consider.
6387 1. The initiating frame no longer exists. In this case we
6388 must stop, because the exception or longjmp has gone too
6391 2. The initiating frame exists, and is the same as the
6392 current frame. We stop, because the exception or longjmp
6395 3. The initiating frame exists and is different from the
6396 current frame. This means the exception or longjmp has
6397 been caught beneath the initiating frame, so keep going.
6399 4. longjmp breakpoint has been placed just to protect
6400 against stale dummy frames and user is not interested in
6401 stopping around longjmps. */
6403 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6405 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6407 delete_exception_resume_breakpoint (ecs
->event_thread
);
6409 if (what
.is_longjmp
)
6411 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6413 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6421 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6425 struct frame_id current_id
6426 = get_frame_id (get_current_frame ());
6427 if (frame_id_eq (current_id
,
6428 ecs
->event_thread
->initiating_frame
))
6430 /* Case 2. Fall through. */
6440 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6442 delete_step_resume_breakpoint (ecs
->event_thread
);
6444 end_stepping_range (ecs
);
6448 case BPSTAT_WHAT_SINGLE
:
6449 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6450 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6451 /* Still need to check other stuff, at least the case where we
6452 are stepping and step out of the right range. */
6455 case BPSTAT_WHAT_STEP_RESUME
:
6456 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6458 delete_step_resume_breakpoint (ecs
->event_thread
);
6459 if (ecs
->event_thread
->control
.proceed_to_finish
6460 && execution_direction
== EXEC_REVERSE
)
6462 struct thread_info
*tp
= ecs
->event_thread
;
6464 /* We are finishing a function in reverse, and just hit the
6465 step-resume breakpoint at the start address of the
6466 function, and we're almost there -- just need to back up
6467 by one more single-step, which should take us back to the
6469 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6473 fill_in_stop_func (gdbarch
, ecs
);
6474 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6475 && execution_direction
== EXEC_REVERSE
)
6477 /* We are stepping over a function call in reverse, and just
6478 hit the step-resume breakpoint at the start address of
6479 the function. Go back to single-stepping, which should
6480 take us back to the function call. */
6481 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6487 case BPSTAT_WHAT_STOP_NOISY
:
6488 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6489 stop_print_frame
= true;
6491 /* Assume the thread stopped for a breakpoint. We'll still check
6492 whether a/the breakpoint is there when the thread is next
6494 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6499 case BPSTAT_WHAT_STOP_SILENT
:
6500 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6501 stop_print_frame
= false;
6503 /* Assume the thread stopped for a breakpoint. We'll still check
6504 whether a/the breakpoint is there when the thread is next
6506 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6510 case BPSTAT_WHAT_HP_STEP_RESUME
:
6511 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6513 delete_step_resume_breakpoint (ecs
->event_thread
);
6514 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6516 /* Back when the step-resume breakpoint was inserted, we
6517 were trying to single-step off a breakpoint. Go back to
6519 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6520 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6526 case BPSTAT_WHAT_KEEP_CHECKING
:
6530 /* If we stepped a permanent breakpoint and we had a high priority
6531 step-resume breakpoint for the address we stepped, but we didn't
6532 hit it, then we must have stepped into the signal handler. The
6533 step-resume was only necessary to catch the case of _not_
6534 stepping into the handler, so delete it, and fall through to
6535 checking whether the step finished. */
6536 if (ecs
->event_thread
->stepped_breakpoint
)
6538 struct breakpoint
*sr_bp
6539 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6542 && sr_bp
->loc
->permanent
6543 && sr_bp
->type
== bp_hp_step_resume
6544 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6546 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6547 delete_step_resume_breakpoint (ecs
->event_thread
);
6548 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6552 /* We come here if we hit a breakpoint but should not stop for it.
6553 Possibly we also were stepping and should stop for that. So fall
6554 through and test for stepping. But, if not stepping, do not
6557 /* In all-stop mode, if we're currently stepping but have stopped in
6558 some other thread, we need to switch back to the stepped thread. */
6559 if (switch_back_to_stepped_thread (ecs
))
6562 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6564 infrun_debug_printf ("step-resume breakpoint is inserted");
6566 /* Having a step-resume breakpoint overrides anything
6567 else having to do with stepping commands until
6568 that breakpoint is reached. */
6573 if (ecs
->event_thread
->control
.step_range_end
== 0)
6575 infrun_debug_printf ("no stepping, continue");
6576 /* Likewise if we aren't even stepping. */
6581 /* Re-fetch current thread's frame in case the code above caused
6582 the frame cache to be re-initialized, making our FRAME variable
6583 a dangling pointer. */
6584 frame
= get_current_frame ();
6585 gdbarch
= get_frame_arch (frame
);
6586 fill_in_stop_func (gdbarch
, ecs
);
6588 /* If stepping through a line, keep going if still within it.
6590 Note that step_range_end is the address of the first instruction
6591 beyond the step range, and NOT the address of the last instruction
6594 Note also that during reverse execution, we may be stepping
6595 through a function epilogue and therefore must detect when
6596 the current-frame changes in the middle of a line. */
6598 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6600 && (execution_direction
!= EXEC_REVERSE
6601 || frame_id_eq (get_frame_id (frame
),
6602 ecs
->event_thread
->control
.step_frame_id
)))
6605 ("stepping inside range [%s-%s]",
6606 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6607 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6609 /* Tentatively re-enable range stepping; `resume' disables it if
6610 necessary (e.g., if we're stepping over a breakpoint or we
6611 have software watchpoints). */
6612 ecs
->event_thread
->control
.may_range_step
= 1;
6614 /* When stepping backward, stop at beginning of line range
6615 (unless it's the function entry point, in which case
6616 keep going back to the call point). */
6617 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6618 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6619 && stop_pc
!= ecs
->stop_func_start
6620 && execution_direction
== EXEC_REVERSE
)
6621 end_stepping_range (ecs
);
6628 /* We stepped out of the stepping range. */
6630 /* If we are stepping at the source level and entered the runtime
6631 loader dynamic symbol resolution code...
6633 EXEC_FORWARD: we keep on single stepping until we exit the run
6634 time loader code and reach the callee's address.
6636 EXEC_REVERSE: we've already executed the callee (backward), and
6637 the runtime loader code is handled just like any other
6638 undebuggable function call. Now we need only keep stepping
6639 backward through the trampoline code, and that's handled further
6640 down, so there is nothing for us to do here. */
6642 if (execution_direction
!= EXEC_REVERSE
6643 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6644 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6646 CORE_ADDR pc_after_resolver
=
6647 gdbarch_skip_solib_resolver (gdbarch
,
6648 ecs
->event_thread
->suspend
.stop_pc
);
6650 infrun_debug_printf ("stepped into dynsym resolve code");
6652 if (pc_after_resolver
)
6654 /* Set up a step-resume breakpoint at the address
6655 indicated by SKIP_SOLIB_RESOLVER. */
6656 symtab_and_line sr_sal
;
6657 sr_sal
.pc
= pc_after_resolver
;
6658 sr_sal
.pspace
= get_frame_program_space (frame
);
6660 insert_step_resume_breakpoint_at_sal (gdbarch
,
6661 sr_sal
, null_frame_id
);
6668 /* Step through an indirect branch thunk. */
6669 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6670 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6671 ecs
->event_thread
->suspend
.stop_pc
))
6673 infrun_debug_printf ("stepped into indirect branch thunk");
6678 if (ecs
->event_thread
->control
.step_range_end
!= 1
6679 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6680 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6681 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6683 infrun_debug_printf ("stepped into signal trampoline");
6684 /* The inferior, while doing a "step" or "next", has ended up in
6685 a signal trampoline (either by a signal being delivered or by
6686 the signal handler returning). Just single-step until the
6687 inferior leaves the trampoline (either by calling the handler
6693 /* If we're in the return path from a shared library trampoline,
6694 we want to proceed through the trampoline when stepping. */
6695 /* macro/2012-04-25: This needs to come before the subroutine
6696 call check below as on some targets return trampolines look
6697 like subroutine calls (MIPS16 return thunks). */
6698 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6699 ecs
->event_thread
->suspend
.stop_pc
,
6700 ecs
->stop_func_name
)
6701 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6703 /* Determine where this trampoline returns. */
6704 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6705 CORE_ADDR real_stop_pc
6706 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6708 infrun_debug_printf ("stepped into solib return tramp");
6710 /* Only proceed through if we know where it's going. */
6713 /* And put the step-breakpoint there and go until there. */
6714 symtab_and_line sr_sal
;
6715 sr_sal
.pc
= real_stop_pc
;
6716 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6717 sr_sal
.pspace
= get_frame_program_space (frame
);
6719 /* Do not specify what the fp should be when we stop since
6720 on some machines the prologue is where the new fp value
6722 insert_step_resume_breakpoint_at_sal (gdbarch
,
6723 sr_sal
, null_frame_id
);
6725 /* Restart without fiddling with the step ranges or
6732 /* Check for subroutine calls. The check for the current frame
6733 equalling the step ID is not necessary - the check of the
6734 previous frame's ID is sufficient - but it is a common case and
6735 cheaper than checking the previous frame's ID.
6737 NOTE: frame_id_eq will never report two invalid frame IDs as
6738 being equal, so to get into this block, both the current and
6739 previous frame must have valid frame IDs. */
6740 /* The outer_frame_id check is a heuristic to detect stepping
6741 through startup code. If we step over an instruction which
6742 sets the stack pointer from an invalid value to a valid value,
6743 we may detect that as a subroutine call from the mythical
6744 "outermost" function. This could be fixed by marking
6745 outermost frames as !stack_p,code_p,special_p. Then the
6746 initial outermost frame, before sp was valid, would
6747 have code_addr == &_start. See the comment in frame_id_eq
6749 if (!frame_id_eq (get_stack_frame_id (frame
),
6750 ecs
->event_thread
->control
.step_stack_frame_id
)
6751 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6752 ecs
->event_thread
->control
.step_stack_frame_id
)
6753 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6755 || (ecs
->event_thread
->control
.step_start_function
6756 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6758 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6759 CORE_ADDR real_stop_pc
;
6761 infrun_debug_printf ("stepped into subroutine");
6763 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6765 /* I presume that step_over_calls is only 0 when we're
6766 supposed to be stepping at the assembly language level
6767 ("stepi"). Just stop. */
6768 /* And this works the same backward as frontward. MVS */
6769 end_stepping_range (ecs
);
6773 /* Reverse stepping through solib trampolines. */
6775 if (execution_direction
== EXEC_REVERSE
6776 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6777 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6778 || (ecs
->stop_func_start
== 0
6779 && in_solib_dynsym_resolve_code (stop_pc
))))
6781 /* Any solib trampoline code can be handled in reverse
6782 by simply continuing to single-step. We have already
6783 executed the solib function (backwards), and a few
6784 steps will take us back through the trampoline to the
6790 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6792 /* We're doing a "next".
6794 Normal (forward) execution: set a breakpoint at the
6795 callee's return address (the address at which the caller
6798 Reverse (backward) execution. set the step-resume
6799 breakpoint at the start of the function that we just
6800 stepped into (backwards), and continue to there. When we
6801 get there, we'll need to single-step back to the caller. */
6803 if (execution_direction
== EXEC_REVERSE
)
6805 /* If we're already at the start of the function, we've either
6806 just stepped backward into a single instruction function,
6807 or stepped back out of a signal handler to the first instruction
6808 of the function. Just keep going, which will single-step back
6810 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6812 /* Normal function call return (static or dynamic). */
6813 symtab_and_line sr_sal
;
6814 sr_sal
.pc
= ecs
->stop_func_start
;
6815 sr_sal
.pspace
= get_frame_program_space (frame
);
6816 insert_step_resume_breakpoint_at_sal (gdbarch
,
6817 sr_sal
, null_frame_id
);
6821 insert_step_resume_breakpoint_at_caller (frame
);
6827 /* If we are in a function call trampoline (a stub between the
6828 calling routine and the real function), locate the real
6829 function. That's what tells us (a) whether we want to step
6830 into it at all, and (b) what prologue we want to run to the
6831 end of, if we do step into it. */
6832 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6833 if (real_stop_pc
== 0)
6834 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6835 if (real_stop_pc
!= 0)
6836 ecs
->stop_func_start
= real_stop_pc
;
6838 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6840 symtab_and_line sr_sal
;
6841 sr_sal
.pc
= ecs
->stop_func_start
;
6842 sr_sal
.pspace
= get_frame_program_space (frame
);
6844 insert_step_resume_breakpoint_at_sal (gdbarch
,
6845 sr_sal
, null_frame_id
);
6850 /* If we have line number information for the function we are
6851 thinking of stepping into and the function isn't on the skip
6854 If there are several symtabs at that PC (e.g. with include
6855 files), just want to know whether *any* of them have line
6856 numbers. find_pc_line handles this. */
6858 struct symtab_and_line tmp_sal
;
6860 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6861 if (tmp_sal
.line
!= 0
6862 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6864 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6866 if (execution_direction
== EXEC_REVERSE
)
6867 handle_step_into_function_backward (gdbarch
, ecs
);
6869 handle_step_into_function (gdbarch
, ecs
);
6874 /* If we have no line number and the step-stop-if-no-debug is
6875 set, we stop the step so that the user has a chance to switch
6876 in assembly mode. */
6877 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6878 && step_stop_if_no_debug
)
6880 end_stepping_range (ecs
);
6884 if (execution_direction
== EXEC_REVERSE
)
6886 /* If we're already at the start of the function, we've either just
6887 stepped backward into a single instruction function without line
6888 number info, or stepped back out of a signal handler to the first
6889 instruction of the function without line number info. Just keep
6890 going, which will single-step back to the caller. */
6891 if (ecs
->stop_func_start
!= stop_pc
)
6893 /* Set a breakpoint at callee's start address.
6894 From there we can step once and be back in the caller. */
6895 symtab_and_line sr_sal
;
6896 sr_sal
.pc
= ecs
->stop_func_start
;
6897 sr_sal
.pspace
= get_frame_program_space (frame
);
6898 insert_step_resume_breakpoint_at_sal (gdbarch
,
6899 sr_sal
, null_frame_id
);
6903 /* Set a breakpoint at callee's return address (the address
6904 at which the caller will resume). */
6905 insert_step_resume_breakpoint_at_caller (frame
);
6911 /* Reverse stepping through solib trampolines. */
6913 if (execution_direction
== EXEC_REVERSE
6914 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6916 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6918 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6919 || (ecs
->stop_func_start
== 0
6920 && in_solib_dynsym_resolve_code (stop_pc
)))
6922 /* Any solib trampoline code can be handled in reverse
6923 by simply continuing to single-step. We have already
6924 executed the solib function (backwards), and a few
6925 steps will take us back through the trampoline to the
6930 else if (in_solib_dynsym_resolve_code (stop_pc
))
6932 /* Stepped backward into the solib dynsym resolver.
6933 Set a breakpoint at its start and continue, then
6934 one more step will take us out. */
6935 symtab_and_line sr_sal
;
6936 sr_sal
.pc
= ecs
->stop_func_start
;
6937 sr_sal
.pspace
= get_frame_program_space (frame
);
6938 insert_step_resume_breakpoint_at_sal (gdbarch
,
6939 sr_sal
, null_frame_id
);
6945 /* This always returns the sal for the inner-most frame when we are in a
6946 stack of inlined frames, even if GDB actually believes that it is in a
6947 more outer frame. This is checked for below by calls to
6948 inline_skipped_frames. */
6949 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6951 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6952 the trampoline processing logic, however, there are some trampolines
6953 that have no names, so we should do trampoline handling first. */
6954 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6955 && ecs
->stop_func_name
== NULL
6956 && stop_pc_sal
.line
== 0)
6958 infrun_debug_printf ("stepped into undebuggable function");
6960 /* The inferior just stepped into, or returned to, an
6961 undebuggable function (where there is no debugging information
6962 and no line number corresponding to the address where the
6963 inferior stopped). Since we want to skip this kind of code,
6964 we keep going until the inferior returns from this
6965 function - unless the user has asked us not to (via
6966 set step-mode) or we no longer know how to get back
6967 to the call site. */
6968 if (step_stop_if_no_debug
6969 || !frame_id_p (frame_unwind_caller_id (frame
)))
6971 /* If we have no line number and the step-stop-if-no-debug
6972 is set, we stop the step so that the user has a chance to
6973 switch in assembly mode. */
6974 end_stepping_range (ecs
);
6979 /* Set a breakpoint at callee's return address (the address
6980 at which the caller will resume). */
6981 insert_step_resume_breakpoint_at_caller (frame
);
6987 if (ecs
->event_thread
->control
.step_range_end
== 1)
6989 /* It is stepi or nexti. We always want to stop stepping after
6991 infrun_debug_printf ("stepi/nexti");
6992 end_stepping_range (ecs
);
6996 if (stop_pc_sal
.line
== 0)
6998 /* We have no line number information. That means to stop
6999 stepping (does this always happen right after one instruction,
7000 when we do "s" in a function with no line numbers,
7001 or can this happen as a result of a return or longjmp?). */
7002 infrun_debug_printf ("line number info");
7003 end_stepping_range (ecs
);
7007 /* Look for "calls" to inlined functions, part one. If the inline
7008 frame machinery detected some skipped call sites, we have entered
7009 a new inline function. */
7011 if (frame_id_eq (get_frame_id (get_current_frame ()),
7012 ecs
->event_thread
->control
.step_frame_id
)
7013 && inline_skipped_frames (ecs
->event_thread
))
7015 infrun_debug_printf ("stepped into inlined function");
7017 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7019 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7021 /* For "step", we're going to stop. But if the call site
7022 for this inlined function is on the same source line as
7023 we were previously stepping, go down into the function
7024 first. Otherwise stop at the call site. */
7026 if (call_sal
.line
== ecs
->event_thread
->current_line
7027 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7029 step_into_inline_frame (ecs
->event_thread
);
7030 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7037 end_stepping_range (ecs
);
7042 /* For "next", we should stop at the call site if it is on a
7043 different source line. Otherwise continue through the
7044 inlined function. */
7045 if (call_sal
.line
== ecs
->event_thread
->current_line
7046 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7049 end_stepping_range (ecs
);
7054 /* Look for "calls" to inlined functions, part two. If we are still
7055 in the same real function we were stepping through, but we have
7056 to go further up to find the exact frame ID, we are stepping
7057 through a more inlined call beyond its call site. */
7059 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7060 && !frame_id_eq (get_frame_id (get_current_frame ()),
7061 ecs
->event_thread
->control
.step_frame_id
)
7062 && stepped_in_from (get_current_frame (),
7063 ecs
->event_thread
->control
.step_frame_id
))
7065 infrun_debug_printf ("stepping through inlined function");
7067 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7068 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7071 end_stepping_range (ecs
);
7075 bool refresh_step_info
= true;
7076 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7077 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7078 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7080 if (stop_pc_sal
.is_stmt
)
7082 /* We are at the start of a different line. So stop. Note that
7083 we don't stop if we step into the middle of a different line.
7084 That is said to make things like for (;;) statements work
7086 infrun_debug_printf ("stepped to a different line");
7087 end_stepping_range (ecs
);
7090 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7091 ecs
->event_thread
->control
.step_frame_id
))
7093 /* We are at the start of a different line, however, this line is
7094 not marked as a statement, and we have not changed frame. We
7095 ignore this line table entry, and continue stepping forward,
7096 looking for a better place to stop. */
7097 refresh_step_info
= false;
7098 infrun_debug_printf ("stepped to a different line, but "
7099 "it's not the start of a statement");
7103 /* We aren't done stepping.
7105 Optimize by setting the stepping range to the line.
7106 (We might not be in the original line, but if we entered a
7107 new line in mid-statement, we continue stepping. This makes
7108 things like for(;;) statements work better.)
7110 If we entered a SAL that indicates a non-statement line table entry,
7111 then we update the stepping range, but we don't update the step info,
7112 which includes things like the line number we are stepping away from.
7113 This means we will stop when we find a line table entry that is marked
7114 as is-statement, even if it matches the non-statement one we just
7117 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7118 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7119 ecs
->event_thread
->control
.may_range_step
= 1;
7120 if (refresh_step_info
)
7121 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7123 infrun_debug_printf ("keep going");
7127 /* In all-stop mode, if we're currently stepping but have stopped in
7128 some other thread, we may need to switch back to the stepped
7129 thread. Returns true we set the inferior running, false if we left
7130 it stopped (and the event needs further processing). */
7133 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7135 if (!target_is_non_stop_p ())
7137 struct thread_info
*stepping_thread
;
7139 /* If any thread is blocked on some internal breakpoint, and we
7140 simply need to step over that breakpoint to get it going
7141 again, do that first. */
7143 /* However, if we see an event for the stepping thread, then we
7144 know all other threads have been moved past their breakpoints
7145 already. Let the caller check whether the step is finished,
7146 etc., before deciding to move it past a breakpoint. */
7147 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7150 /* Check if the current thread is blocked on an incomplete
7151 step-over, interrupted by a random signal. */
7152 if (ecs
->event_thread
->control
.trap_expected
7153 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7156 ("need to finish step-over of [%s]",
7157 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7162 /* Check if the current thread is blocked by a single-step
7163 breakpoint of another thread. */
7164 if (ecs
->hit_singlestep_breakpoint
)
7166 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7167 target_pid_to_str (ecs
->ptid
).c_str ());
7172 /* If this thread needs yet another step-over (e.g., stepping
7173 through a delay slot), do it first before moving on to
7175 if (thread_still_needs_step_over (ecs
->event_thread
))
7178 ("thread [%s] still needs step-over",
7179 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7184 /* If scheduler locking applies even if not stepping, there's no
7185 need to walk over threads. Above we've checked whether the
7186 current thread is stepping. If some other thread not the
7187 event thread is stepping, then it must be that scheduler
7188 locking is not in effect. */
7189 if (schedlock_applies (ecs
->event_thread
))
7192 /* Otherwise, we no longer expect a trap in the current thread.
7193 Clear the trap_expected flag before switching back -- this is
7194 what keep_going does as well, if we call it. */
7195 ecs
->event_thread
->control
.trap_expected
= 0;
7197 /* Likewise, clear the signal if it should not be passed. */
7198 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7199 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7201 /* Do all pending step-overs before actually proceeding with
7203 if (start_step_over ())
7205 prepare_to_wait (ecs
);
7209 /* Look for the stepping/nexting thread. */
7210 stepping_thread
= NULL
;
7212 for (thread_info
*tp
: all_non_exited_threads ())
7214 switch_to_thread_no_regs (tp
);
7216 /* Ignore threads of processes the caller is not
7219 && (tp
->inf
->process_target () != ecs
->target
7220 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7223 /* When stepping over a breakpoint, we lock all threads
7224 except the one that needs to move past the breakpoint.
7225 If a non-event thread has this set, the "incomplete
7226 step-over" check above should have caught it earlier. */
7227 if (tp
->control
.trap_expected
)
7229 internal_error (__FILE__
, __LINE__
,
7230 "[%s] has inconsistent state: "
7231 "trap_expected=%d\n",
7232 target_pid_to_str (tp
->ptid
).c_str (),
7233 tp
->control
.trap_expected
);
7236 /* Did we find the stepping thread? */
7237 if (tp
->control
.step_range_end
)
7239 /* Yep. There should only one though. */
7240 gdb_assert (stepping_thread
== NULL
);
7242 /* The event thread is handled at the top, before we
7244 gdb_assert (tp
!= ecs
->event_thread
);
7246 /* If some thread other than the event thread is
7247 stepping, then scheduler locking can't be in effect,
7248 otherwise we wouldn't have resumed the current event
7249 thread in the first place. */
7250 gdb_assert (!schedlock_applies (tp
));
7252 stepping_thread
= tp
;
7256 if (stepping_thread
!= NULL
)
7258 infrun_debug_printf ("switching back to stepped thread");
7260 if (keep_going_stepped_thread (stepping_thread
))
7262 prepare_to_wait (ecs
);
7267 switch_to_thread (ecs
->event_thread
);
7273 /* Set a previously stepped thread back to stepping. Returns true on
7274 success, false if the resume is not possible (e.g., the thread
7278 keep_going_stepped_thread (struct thread_info
*tp
)
7280 struct frame_info
*frame
;
7281 struct execution_control_state ecss
;
7282 struct execution_control_state
*ecs
= &ecss
;
7284 /* If the stepping thread exited, then don't try to switch back and
7285 resume it, which could fail in several different ways depending
7286 on the target. Instead, just keep going.
7288 We can find a stepping dead thread in the thread list in two
7291 - The target supports thread exit events, and when the target
7292 tries to delete the thread from the thread list, inferior_ptid
7293 pointed at the exiting thread. In such case, calling
7294 delete_thread does not really remove the thread from the list;
7295 instead, the thread is left listed, with 'exited' state.
7297 - The target's debug interface does not support thread exit
7298 events, and so we have no idea whatsoever if the previously
7299 stepping thread is still alive. For that reason, we need to
7300 synchronously query the target now. */
7302 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7304 infrun_debug_printf ("not resuming previously stepped thread, it has "
7311 infrun_debug_printf ("resuming previously stepped thread");
7313 reset_ecs (ecs
, tp
);
7314 switch_to_thread (tp
);
7316 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7317 frame
= get_current_frame ();
7319 /* If the PC of the thread we were trying to single-step has
7320 changed, then that thread has trapped or been signaled, but the
7321 event has not been reported to GDB yet. Re-poll the target
7322 looking for this particular thread's event (i.e. temporarily
7323 enable schedlock) by:
7325 - setting a break at the current PC
7326 - resuming that particular thread, only (by setting trap
7329 This prevents us continuously moving the single-step breakpoint
7330 forward, one instruction at a time, overstepping. */
7332 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7336 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7337 paddress (target_gdbarch (), tp
->prev_pc
),
7338 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7340 /* Clear the info of the previous step-over, as it's no longer
7341 valid (if the thread was trying to step over a breakpoint, it
7342 has already succeeded). It's what keep_going would do too,
7343 if we called it. Do this before trying to insert the sss
7344 breakpoint, otherwise if we were previously trying to step
7345 over this exact address in another thread, the breakpoint is
7347 clear_step_over_info ();
7348 tp
->control
.trap_expected
= 0;
7350 insert_single_step_breakpoint (get_frame_arch (frame
),
7351 get_frame_address_space (frame
),
7352 tp
->suspend
.stop_pc
);
7355 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7356 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7360 infrun_debug_printf ("expected thread still hasn't advanced");
7362 keep_going_pass_signal (ecs
);
7368 /* Is thread TP in the middle of (software or hardware)
7369 single-stepping? (Note the result of this function must never be
7370 passed directly as target_resume's STEP parameter.) */
7373 currently_stepping (struct thread_info
*tp
)
7375 return ((tp
->control
.step_range_end
7376 && tp
->control
.step_resume_breakpoint
== NULL
)
7377 || tp
->control
.trap_expected
7378 || tp
->stepped_breakpoint
7379 || bpstat_should_step ());
7382 /* Inferior has stepped into a subroutine call with source code that
7383 we should not step over. Do step to the first line of code in
7387 handle_step_into_function (struct gdbarch
*gdbarch
,
7388 struct execution_control_state
*ecs
)
7390 fill_in_stop_func (gdbarch
, ecs
);
7392 compunit_symtab
*cust
7393 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7394 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7395 ecs
->stop_func_start
7396 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7398 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7399 /* Use the step_resume_break to step until the end of the prologue,
7400 even if that involves jumps (as it seems to on the vax under
7402 /* If the prologue ends in the middle of a source line, continue to
7403 the end of that source line (if it is still within the function).
7404 Otherwise, just go to end of prologue. */
7405 if (stop_func_sal
.end
7406 && stop_func_sal
.pc
!= ecs
->stop_func_start
7407 && stop_func_sal
.end
< ecs
->stop_func_end
)
7408 ecs
->stop_func_start
= stop_func_sal
.end
;
7410 /* Architectures which require breakpoint adjustment might not be able
7411 to place a breakpoint at the computed address. If so, the test
7412 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7413 ecs->stop_func_start to an address at which a breakpoint may be
7414 legitimately placed.
7416 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7417 made, GDB will enter an infinite loop when stepping through
7418 optimized code consisting of VLIW instructions which contain
7419 subinstructions corresponding to different source lines. On
7420 FR-V, it's not permitted to place a breakpoint on any but the
7421 first subinstruction of a VLIW instruction. When a breakpoint is
7422 set, GDB will adjust the breakpoint address to the beginning of
7423 the VLIW instruction. Thus, we need to make the corresponding
7424 adjustment here when computing the stop address. */
7426 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7428 ecs
->stop_func_start
7429 = gdbarch_adjust_breakpoint_address (gdbarch
,
7430 ecs
->stop_func_start
);
7433 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7435 /* We are already there: stop now. */
7436 end_stepping_range (ecs
);
7441 /* Put the step-breakpoint there and go until there. */
7442 symtab_and_line sr_sal
;
7443 sr_sal
.pc
= ecs
->stop_func_start
;
7444 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7445 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7447 /* Do not specify what the fp should be when we stop since on
7448 some machines the prologue is where the new fp value is
7450 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7452 /* And make sure stepping stops right away then. */
7453 ecs
->event_thread
->control
.step_range_end
7454 = ecs
->event_thread
->control
.step_range_start
;
7459 /* Inferior has stepped backward into a subroutine call with source
7460 code that we should not step over. Do step to the beginning of the
7461 last line of code in it. */
7464 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7465 struct execution_control_state
*ecs
)
7467 struct compunit_symtab
*cust
;
7468 struct symtab_and_line stop_func_sal
;
7470 fill_in_stop_func (gdbarch
, ecs
);
7472 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7473 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7474 ecs
->stop_func_start
7475 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7477 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7479 /* OK, we're just going to keep stepping here. */
7480 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7482 /* We're there already. Just stop stepping now. */
7483 end_stepping_range (ecs
);
7487 /* Else just reset the step range and keep going.
7488 No step-resume breakpoint, they don't work for
7489 epilogues, which can have multiple entry paths. */
7490 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7491 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7497 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7498 This is used to both functions and to skip over code. */
7501 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7502 struct symtab_and_line sr_sal
,
7503 struct frame_id sr_id
,
7504 enum bptype sr_type
)
7506 /* There should never be more than one step-resume or longjmp-resume
7507 breakpoint per thread, so we should never be setting a new
7508 step_resume_breakpoint when one is already active. */
7509 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7510 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7512 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7513 paddress (gdbarch
, sr_sal
.pc
));
7515 inferior_thread ()->control
.step_resume_breakpoint
7516 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7520 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7521 struct symtab_and_line sr_sal
,
7522 struct frame_id sr_id
)
7524 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7529 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7530 This is used to skip a potential signal handler.
7532 This is called with the interrupted function's frame. The signal
7533 handler, when it returns, will resume the interrupted function at
7537 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7539 gdb_assert (return_frame
!= NULL
);
7541 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7543 symtab_and_line sr_sal
;
7544 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7545 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7546 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7548 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7549 get_stack_frame_id (return_frame
),
7553 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7554 is used to skip a function after stepping into it (for "next" or if
7555 the called function has no debugging information).
7557 The current function has almost always been reached by single
7558 stepping a call or return instruction. NEXT_FRAME belongs to the
7559 current function, and the breakpoint will be set at the caller's
7562 This is a separate function rather than reusing
7563 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7564 get_prev_frame, which may stop prematurely (see the implementation
7565 of frame_unwind_caller_id for an example). */
7568 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7570 /* We shouldn't have gotten here if we don't know where the call site
7572 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7574 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7576 symtab_and_line sr_sal
;
7577 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7578 frame_unwind_caller_pc (next_frame
));
7579 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7580 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7582 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7583 frame_unwind_caller_id (next_frame
));
7586 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7587 new breakpoint at the target of a jmp_buf. The handling of
7588 longjmp-resume uses the same mechanisms used for handling
7589 "step-resume" breakpoints. */
7592 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7594 /* There should never be more than one longjmp-resume breakpoint per
7595 thread, so we should never be setting a new
7596 longjmp_resume_breakpoint when one is already active. */
7597 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7599 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7600 paddress (gdbarch
, pc
));
7602 inferior_thread ()->control
.exception_resume_breakpoint
=
7603 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7606 /* Insert an exception resume breakpoint. TP is the thread throwing
7607 the exception. The block B is the block of the unwinder debug hook
7608 function. FRAME is the frame corresponding to the call to this
7609 function. SYM is the symbol of the function argument holding the
7610 target PC of the exception. */
7613 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7614 const struct block
*b
,
7615 struct frame_info
*frame
,
7620 struct block_symbol vsym
;
7621 struct value
*value
;
7623 struct breakpoint
*bp
;
7625 vsym
= lookup_symbol_search_name (sym
->search_name (),
7627 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7628 /* If the value was optimized out, revert to the old behavior. */
7629 if (! value_optimized_out (value
))
7631 handler
= value_as_address (value
);
7633 infrun_debug_printf ("exception resume at %lx",
7634 (unsigned long) handler
);
7636 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7638 bp_exception_resume
).release ();
7640 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7643 bp
->thread
= tp
->global_num
;
7644 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7647 catch (const gdb_exception_error
&e
)
7649 /* We want to ignore errors here. */
7653 /* A helper for check_exception_resume that sets an
7654 exception-breakpoint based on a SystemTap probe. */
7657 insert_exception_resume_from_probe (struct thread_info
*tp
,
7658 const struct bound_probe
*probe
,
7659 struct frame_info
*frame
)
7661 struct value
*arg_value
;
7663 struct breakpoint
*bp
;
7665 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7669 handler
= value_as_address (arg_value
);
7671 infrun_debug_printf ("exception resume at %s",
7672 paddress (probe
->objfile
->arch (), handler
));
7674 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7675 handler
, bp_exception_resume
).release ();
7676 bp
->thread
= tp
->global_num
;
7677 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7680 /* This is called when an exception has been intercepted. Check to
7681 see whether the exception's destination is of interest, and if so,
7682 set an exception resume breakpoint there. */
7685 check_exception_resume (struct execution_control_state
*ecs
,
7686 struct frame_info
*frame
)
7688 struct bound_probe probe
;
7689 struct symbol
*func
;
7691 /* First see if this exception unwinding breakpoint was set via a
7692 SystemTap probe point. If so, the probe has two arguments: the
7693 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7694 set a breakpoint there. */
7695 probe
= find_probe_by_pc (get_frame_pc (frame
));
7698 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7702 func
= get_frame_function (frame
);
7708 const struct block
*b
;
7709 struct block_iterator iter
;
7713 /* The exception breakpoint is a thread-specific breakpoint on
7714 the unwinder's debug hook, declared as:
7716 void _Unwind_DebugHook (void *cfa, void *handler);
7718 The CFA argument indicates the frame to which control is
7719 about to be transferred. HANDLER is the destination PC.
7721 We ignore the CFA and set a temporary breakpoint at HANDLER.
7722 This is not extremely efficient but it avoids issues in gdb
7723 with computing the DWARF CFA, and it also works even in weird
7724 cases such as throwing an exception from inside a signal
7727 b
= SYMBOL_BLOCK_VALUE (func
);
7728 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7730 if (!SYMBOL_IS_ARGUMENT (sym
))
7737 insert_exception_resume_breakpoint (ecs
->event_thread
,
7743 catch (const gdb_exception_error
&e
)
7749 stop_waiting (struct execution_control_state
*ecs
)
7751 infrun_debug_printf ("stop_waiting");
7753 /* Let callers know we don't want to wait for the inferior anymore. */
7754 ecs
->wait_some_more
= 0;
7756 /* If all-stop, but there exists a non-stop target, stop all
7757 threads now that we're presenting the stop to the user. */
7758 if (!non_stop
&& exists_non_stop_target ())
7759 stop_all_threads ();
7762 /* Like keep_going, but passes the signal to the inferior, even if the
7763 signal is set to nopass. */
7766 keep_going_pass_signal (struct execution_control_state
*ecs
)
7768 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7769 gdb_assert (!ecs
->event_thread
->resumed
);
7771 /* Save the pc before execution, to compare with pc after stop. */
7772 ecs
->event_thread
->prev_pc
7773 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7775 if (ecs
->event_thread
->control
.trap_expected
)
7777 struct thread_info
*tp
= ecs
->event_thread
;
7779 infrun_debug_printf ("%s has trap_expected set, "
7780 "resuming to collect trap",
7781 target_pid_to_str (tp
->ptid
).c_str ());
7783 /* We haven't yet gotten our trap, and either: intercepted a
7784 non-signal event (e.g., a fork); or took a signal which we
7785 are supposed to pass through to the inferior. Simply
7787 resume (ecs
->event_thread
->suspend
.stop_signal
);
7789 else if (step_over_info_valid_p ())
7791 /* Another thread is stepping over a breakpoint in-line. If
7792 this thread needs a step-over too, queue the request. In
7793 either case, this resume must be deferred for later. */
7794 struct thread_info
*tp
= ecs
->event_thread
;
7796 if (ecs
->hit_singlestep_breakpoint
7797 || thread_still_needs_step_over (tp
))
7799 infrun_debug_printf ("step-over already in progress: "
7800 "step-over for %s deferred",
7801 target_pid_to_str (tp
->ptid
).c_str ());
7802 thread_step_over_chain_enqueue (tp
);
7806 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7807 target_pid_to_str (tp
->ptid
).c_str ());
7812 struct regcache
*regcache
= get_current_regcache ();
7815 step_over_what step_what
;
7817 /* Either the trap was not expected, but we are continuing
7818 anyway (if we got a signal, the user asked it be passed to
7821 We got our expected trap, but decided we should resume from
7824 We're going to run this baby now!
7826 Note that insert_breakpoints won't try to re-insert
7827 already inserted breakpoints. Therefore, we don't
7828 care if breakpoints were already inserted, or not. */
7830 /* If we need to step over a breakpoint, and we're not using
7831 displaced stepping to do so, insert all breakpoints
7832 (watchpoints, etc.) but the one we're stepping over, step one
7833 instruction, and then re-insert the breakpoint when that step
7836 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7838 remove_bp
= (ecs
->hit_singlestep_breakpoint
7839 || (step_what
& STEP_OVER_BREAKPOINT
));
7840 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7842 /* We can't use displaced stepping if we need to step past a
7843 watchpoint. The instruction copied to the scratch pad would
7844 still trigger the watchpoint. */
7846 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7848 set_step_over_info (regcache
->aspace (),
7849 regcache_read_pc (regcache
), remove_wps
,
7850 ecs
->event_thread
->global_num
);
7852 else if (remove_wps
)
7853 set_step_over_info (NULL
, 0, remove_wps
, -1);
7855 /* If we now need to do an in-line step-over, we need to stop
7856 all other threads. Note this must be done before
7857 insert_breakpoints below, because that removes the breakpoint
7858 we're about to step over, otherwise other threads could miss
7860 if (step_over_info_valid_p () && target_is_non_stop_p ())
7861 stop_all_threads ();
7863 /* Stop stepping if inserting breakpoints fails. */
7866 insert_breakpoints ();
7868 catch (const gdb_exception_error
&e
)
7870 exception_print (gdb_stderr
, e
);
7872 clear_step_over_info ();
7876 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7878 resume (ecs
->event_thread
->suspend
.stop_signal
);
7881 prepare_to_wait (ecs
);
7884 /* Called when we should continue running the inferior, because the
7885 current event doesn't cause a user visible stop. This does the
7886 resuming part; waiting for the next event is done elsewhere. */
7889 keep_going (struct execution_control_state
*ecs
)
7891 if (ecs
->event_thread
->control
.trap_expected
7892 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7893 ecs
->event_thread
->control
.trap_expected
= 0;
7895 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7896 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7897 keep_going_pass_signal (ecs
);
7900 /* This function normally comes after a resume, before
7901 handle_inferior_event exits. It takes care of any last bits of
7902 housekeeping, and sets the all-important wait_some_more flag. */
7905 prepare_to_wait (struct execution_control_state
*ecs
)
7907 infrun_debug_printf ("prepare_to_wait");
7909 ecs
->wait_some_more
= 1;
7911 /* If the target can't async, emulate it by marking the infrun event
7912 handler such that as soon as we get back to the event-loop, we
7913 immediately end up in fetch_inferior_event again calling
7915 if (!target_can_async_p ())
7916 mark_infrun_async_event_handler ();
7919 /* We are done with the step range of a step/next/si/ni command.
7920 Called once for each n of a "step n" operation. */
7923 end_stepping_range (struct execution_control_state
*ecs
)
7925 ecs
->event_thread
->control
.stop_step
= 1;
7929 /* Several print_*_reason functions to print why the inferior has stopped.
7930 We always print something when the inferior exits, or receives a signal.
7931 The rest of the cases are dealt with later on in normal_stop and
7932 print_it_typical. Ideally there should be a call to one of these
7933 print_*_reason functions functions from handle_inferior_event each time
7934 stop_waiting is called.
7936 Note that we don't call these directly, instead we delegate that to
7937 the interpreters, through observers. Interpreters then call these
7938 with whatever uiout is right. */
7941 print_end_stepping_range_reason (struct ui_out
*uiout
)
7943 /* For CLI-like interpreters, print nothing. */
7945 if (uiout
->is_mi_like_p ())
7947 uiout
->field_string ("reason",
7948 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7953 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7955 annotate_signalled ();
7956 if (uiout
->is_mi_like_p ())
7958 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7959 uiout
->text ("\nProgram terminated with signal ");
7960 annotate_signal_name ();
7961 uiout
->field_string ("signal-name",
7962 gdb_signal_to_name (siggnal
));
7963 annotate_signal_name_end ();
7965 annotate_signal_string ();
7966 uiout
->field_string ("signal-meaning",
7967 gdb_signal_to_string (siggnal
));
7968 annotate_signal_string_end ();
7969 uiout
->text (".\n");
7970 uiout
->text ("The program no longer exists.\n");
7974 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7976 struct inferior
*inf
= current_inferior ();
7977 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7979 annotate_exited (exitstatus
);
7982 if (uiout
->is_mi_like_p ())
7983 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7984 std::string exit_code_str
7985 = string_printf ("0%o", (unsigned int) exitstatus
);
7986 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7987 plongest (inf
->num
), pidstr
.c_str (),
7988 string_field ("exit-code", exit_code_str
.c_str ()));
7992 if (uiout
->is_mi_like_p ())
7994 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7995 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7996 plongest (inf
->num
), pidstr
.c_str ());
8001 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8003 struct thread_info
*thr
= inferior_thread ();
8007 if (uiout
->is_mi_like_p ())
8009 else if (show_thread_that_caused_stop ())
8013 uiout
->text ("\nThread ");
8014 uiout
->field_string ("thread-id", print_thread_id (thr
));
8016 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8019 uiout
->text (" \"");
8020 uiout
->field_string ("name", name
);
8025 uiout
->text ("\nProgram");
8027 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8028 uiout
->text (" stopped");
8031 uiout
->text (" received signal ");
8032 annotate_signal_name ();
8033 if (uiout
->is_mi_like_p ())
8035 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8036 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8037 annotate_signal_name_end ();
8039 annotate_signal_string ();
8040 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8042 struct regcache
*regcache
= get_current_regcache ();
8043 struct gdbarch
*gdbarch
= regcache
->arch ();
8044 if (gdbarch_report_signal_info_p (gdbarch
))
8045 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8047 annotate_signal_string_end ();
8049 uiout
->text (".\n");
8053 print_no_history_reason (struct ui_out
*uiout
)
8055 uiout
->text ("\nNo more reverse-execution history.\n");
8058 /* Print current location without a level number, if we have changed
8059 functions or hit a breakpoint. Print source line if we have one.
8060 bpstat_print contains the logic deciding in detail what to print,
8061 based on the event(s) that just occurred. */
8064 print_stop_location (struct target_waitstatus
*ws
)
8067 enum print_what source_flag
;
8068 int do_frame_printing
= 1;
8069 struct thread_info
*tp
= inferior_thread ();
8071 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8075 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8076 should) carry around the function and does (or should) use
8077 that when doing a frame comparison. */
8078 if (tp
->control
.stop_step
8079 && frame_id_eq (tp
->control
.step_frame_id
,
8080 get_frame_id (get_current_frame ()))
8081 && (tp
->control
.step_start_function
8082 == find_pc_function (tp
->suspend
.stop_pc
)))
8084 /* Finished step, just print source line. */
8085 source_flag
= SRC_LINE
;
8089 /* Print location and source line. */
8090 source_flag
= SRC_AND_LOC
;
8093 case PRINT_SRC_AND_LOC
:
8094 /* Print location and source line. */
8095 source_flag
= SRC_AND_LOC
;
8097 case PRINT_SRC_ONLY
:
8098 source_flag
= SRC_LINE
;
8101 /* Something bogus. */
8102 source_flag
= SRC_LINE
;
8103 do_frame_printing
= 0;
8106 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8109 /* The behavior of this routine with respect to the source
8111 SRC_LINE: Print only source line
8112 LOCATION: Print only location
8113 SRC_AND_LOC: Print location and source line. */
8114 if (do_frame_printing
)
8115 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8121 print_stop_event (struct ui_out
*uiout
, bool displays
)
8123 struct target_waitstatus last
;
8124 struct thread_info
*tp
;
8126 get_last_target_status (nullptr, nullptr, &last
);
8129 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8131 print_stop_location (&last
);
8133 /* Display the auto-display expressions. */
8138 tp
= inferior_thread ();
8139 if (tp
->thread_fsm
!= NULL
8140 && tp
->thread_fsm
->finished_p ())
8142 struct return_value_info
*rv
;
8144 rv
= tp
->thread_fsm
->return_value ();
8146 print_return_value (uiout
, rv
);
8153 maybe_remove_breakpoints (void)
8155 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8157 if (remove_breakpoints ())
8159 target_terminal::ours_for_output ();
8160 printf_filtered (_("Cannot remove breakpoints because "
8161 "program is no longer writable.\nFurther "
8162 "execution is probably impossible.\n"));
8167 /* The execution context that just caused a normal stop. */
8174 DISABLE_COPY_AND_ASSIGN (stop_context
);
8176 bool changed () const;
8181 /* The event PTID. */
8185 /* If stopp for a thread event, this is the thread that caused the
8187 struct thread_info
*thread
;
8189 /* The inferior that caused the stop. */
8193 /* Initializes a new stop context. If stopped for a thread event, this
8194 takes a strong reference to the thread. */
8196 stop_context::stop_context ()
8198 stop_id
= get_stop_id ();
8199 ptid
= inferior_ptid
;
8200 inf_num
= current_inferior ()->num
;
8202 if (inferior_ptid
!= null_ptid
)
8204 /* Take a strong reference so that the thread can't be deleted
8206 thread
= inferior_thread ();
8213 /* Release a stop context previously created with save_stop_context.
8214 Releases the strong reference to the thread as well. */
8216 stop_context::~stop_context ()
8222 /* Return true if the current context no longer matches the saved stop
8226 stop_context::changed () const
8228 if (ptid
!= inferior_ptid
)
8230 if (inf_num
!= current_inferior ()->num
)
8232 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8234 if (get_stop_id () != stop_id
)
8244 struct target_waitstatus last
;
8246 get_last_target_status (nullptr, nullptr, &last
);
8250 /* If an exception is thrown from this point on, make sure to
8251 propagate GDB's knowledge of the executing state to the
8252 frontend/user running state. A QUIT is an easy exception to see
8253 here, so do this before any filtered output. */
8255 ptid_t finish_ptid
= null_ptid
;
8258 finish_ptid
= minus_one_ptid
;
8259 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8260 || last
.kind
== TARGET_WAITKIND_EXITED
)
8262 /* On some targets, we may still have live threads in the
8263 inferior when we get a process exit event. E.g., for
8264 "checkpoint", when the current checkpoint/fork exits,
8265 linux-fork.c automatically switches to another fork from
8266 within target_mourn_inferior. */
8267 if (inferior_ptid
!= null_ptid
)
8268 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8270 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8271 finish_ptid
= inferior_ptid
;
8273 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8274 if (finish_ptid
!= null_ptid
)
8276 maybe_finish_thread_state
.emplace
8277 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8280 /* As we're presenting a stop, and potentially removing breakpoints,
8281 update the thread list so we can tell whether there are threads
8282 running on the target. With target remote, for example, we can
8283 only learn about new threads when we explicitly update the thread
8284 list. Do this before notifying the interpreters about signal
8285 stops, end of stepping ranges, etc., so that the "new thread"
8286 output is emitted before e.g., "Program received signal FOO",
8287 instead of after. */
8288 update_thread_list ();
8290 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8291 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8293 /* As with the notification of thread events, we want to delay
8294 notifying the user that we've switched thread context until
8295 the inferior actually stops.
8297 There's no point in saying anything if the inferior has exited.
8298 Note that SIGNALLED here means "exited with a signal", not
8299 "received a signal".
8301 Also skip saying anything in non-stop mode. In that mode, as we
8302 don't want GDB to switch threads behind the user's back, to avoid
8303 races where the user is typing a command to apply to thread x,
8304 but GDB switches to thread y before the user finishes entering
8305 the command, fetch_inferior_event installs a cleanup to restore
8306 the current thread back to the thread the user had selected right
8307 after this event is handled, so we're not really switching, only
8308 informing of a stop. */
8310 && previous_inferior_ptid
!= inferior_ptid
8311 && target_has_execution ()
8312 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8313 && last
.kind
!= TARGET_WAITKIND_EXITED
8314 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8316 SWITCH_THRU_ALL_UIS ()
8318 target_terminal::ours_for_output ();
8319 printf_filtered (_("[Switching to %s]\n"),
8320 target_pid_to_str (inferior_ptid
).c_str ());
8321 annotate_thread_changed ();
8323 previous_inferior_ptid
= inferior_ptid
;
8326 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8328 SWITCH_THRU_ALL_UIS ()
8329 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8331 target_terminal::ours_for_output ();
8332 printf_filtered (_("No unwaited-for children left.\n"));
8336 /* Note: this depends on the update_thread_list call above. */
8337 maybe_remove_breakpoints ();
8339 /* If an auto-display called a function and that got a signal,
8340 delete that auto-display to avoid an infinite recursion. */
8342 if (stopped_by_random_signal
)
8343 disable_current_display ();
8345 SWITCH_THRU_ALL_UIS ()
8347 async_enable_stdin ();
8350 /* Let the user/frontend see the threads as stopped. */
8351 maybe_finish_thread_state
.reset ();
8353 /* Select innermost stack frame - i.e., current frame is frame 0,
8354 and current location is based on that. Handle the case where the
8355 dummy call is returning after being stopped. E.g. the dummy call
8356 previously hit a breakpoint. (If the dummy call returns
8357 normally, we won't reach here.) Do this before the stop hook is
8358 run, so that it doesn't get to see the temporary dummy frame,
8359 which is not where we'll present the stop. */
8360 if (has_stack_frames ())
8362 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8364 /* Pop the empty frame that contains the stack dummy. This
8365 also restores inferior state prior to the call (struct
8366 infcall_suspend_state). */
8367 struct frame_info
*frame
= get_current_frame ();
8369 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8371 /* frame_pop calls reinit_frame_cache as the last thing it
8372 does which means there's now no selected frame. */
8375 select_frame (get_current_frame ());
8377 /* Set the current source location. */
8378 set_current_sal_from_frame (get_current_frame ());
8381 /* Look up the hook_stop and run it (CLI internally handles problem
8382 of stop_command's pre-hook not existing). */
8383 if (stop_command
!= NULL
)
8385 stop_context saved_context
;
8389 execute_cmd_pre_hook (stop_command
);
8391 catch (const gdb_exception
&ex
)
8393 exception_fprintf (gdb_stderr
, ex
,
8394 "Error while running hook_stop:\n");
8397 /* If the stop hook resumes the target, then there's no point in
8398 trying to notify about the previous stop; its context is
8399 gone. Likewise if the command switches thread or inferior --
8400 the observers would print a stop for the wrong
8402 if (saved_context
.changed ())
8406 /* Notify observers about the stop. This is where the interpreters
8407 print the stop event. */
8408 if (inferior_ptid
!= null_ptid
)
8409 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8412 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8414 annotate_stopped ();
8416 if (target_has_execution ())
8418 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8419 && last
.kind
!= TARGET_WAITKIND_EXITED
8420 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8421 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8422 Delete any breakpoint that is to be deleted at the next stop. */
8423 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8426 /* Try to get rid of automatically added inferiors that are no
8427 longer needed. Keeping those around slows down things linearly.
8428 Note that this never removes the current inferior. */
8435 signal_stop_state (int signo
)
8437 return signal_stop
[signo
];
8441 signal_print_state (int signo
)
8443 return signal_print
[signo
];
8447 signal_pass_state (int signo
)
8449 return signal_program
[signo
];
8453 signal_cache_update (int signo
)
8457 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8458 signal_cache_update (signo
);
8463 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8464 && signal_print
[signo
] == 0
8465 && signal_program
[signo
] == 1
8466 && signal_catch
[signo
] == 0);
8470 signal_stop_update (int signo
, int state
)
8472 int ret
= signal_stop
[signo
];
8474 signal_stop
[signo
] = state
;
8475 signal_cache_update (signo
);
8480 signal_print_update (int signo
, int state
)
8482 int ret
= signal_print
[signo
];
8484 signal_print
[signo
] = state
;
8485 signal_cache_update (signo
);
8490 signal_pass_update (int signo
, int state
)
8492 int ret
= signal_program
[signo
];
8494 signal_program
[signo
] = state
;
8495 signal_cache_update (signo
);
8499 /* Update the global 'signal_catch' from INFO and notify the
8503 signal_catch_update (const unsigned int *info
)
8507 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8508 signal_catch
[i
] = info
[i
] > 0;
8509 signal_cache_update (-1);
8510 target_pass_signals (signal_pass
);
8514 sig_print_header (void)
8516 printf_filtered (_("Signal Stop\tPrint\tPass "
8517 "to program\tDescription\n"));
8521 sig_print_info (enum gdb_signal oursig
)
8523 const char *name
= gdb_signal_to_name (oursig
);
8524 int name_padding
= 13 - strlen (name
);
8526 if (name_padding
<= 0)
8529 printf_filtered ("%s", name
);
8530 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8531 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8532 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8533 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8534 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8537 /* Specify how various signals in the inferior should be handled. */
8540 handle_command (const char *args
, int from_tty
)
8542 int digits
, wordlen
;
8543 int sigfirst
, siglast
;
8544 enum gdb_signal oursig
;
8549 error_no_arg (_("signal to handle"));
8552 /* Allocate and zero an array of flags for which signals to handle. */
8554 const size_t nsigs
= GDB_SIGNAL_LAST
;
8555 unsigned char sigs
[nsigs
] {};
8557 /* Break the command line up into args. */
8559 gdb_argv
built_argv (args
);
8561 /* Walk through the args, looking for signal oursigs, signal names, and
8562 actions. Signal numbers and signal names may be interspersed with
8563 actions, with the actions being performed for all signals cumulatively
8564 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8566 for (char *arg
: built_argv
)
8568 wordlen
= strlen (arg
);
8569 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8573 sigfirst
= siglast
= -1;
8575 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8577 /* Apply action to all signals except those used by the
8578 debugger. Silently skip those. */
8581 siglast
= nsigs
- 1;
8583 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8585 SET_SIGS (nsigs
, sigs
, signal_stop
);
8586 SET_SIGS (nsigs
, sigs
, signal_print
);
8588 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8590 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8592 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8594 SET_SIGS (nsigs
, sigs
, signal_print
);
8596 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8598 SET_SIGS (nsigs
, sigs
, signal_program
);
8600 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8602 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8604 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8606 SET_SIGS (nsigs
, sigs
, signal_program
);
8608 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8610 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8611 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8613 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8615 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8617 else if (digits
> 0)
8619 /* It is numeric. The numeric signal refers to our own
8620 internal signal numbering from target.h, not to host/target
8621 signal number. This is a feature; users really should be
8622 using symbolic names anyway, and the common ones like
8623 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8625 sigfirst
= siglast
= (int)
8626 gdb_signal_from_command (atoi (arg
));
8627 if (arg
[digits
] == '-')
8630 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8632 if (sigfirst
> siglast
)
8634 /* Bet he didn't figure we'd think of this case... */
8635 std::swap (sigfirst
, siglast
);
8640 oursig
= gdb_signal_from_name (arg
);
8641 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8643 sigfirst
= siglast
= (int) oursig
;
8647 /* Not a number and not a recognized flag word => complain. */
8648 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8652 /* If any signal numbers or symbol names were found, set flags for
8653 which signals to apply actions to. */
8655 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8657 switch ((enum gdb_signal
) signum
)
8659 case GDB_SIGNAL_TRAP
:
8660 case GDB_SIGNAL_INT
:
8661 if (!allsigs
&& !sigs
[signum
])
8663 if (query (_("%s is used by the debugger.\n\
8664 Are you sure you want to change it? "),
8665 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8670 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8674 case GDB_SIGNAL_DEFAULT
:
8675 case GDB_SIGNAL_UNKNOWN
:
8676 /* Make sure that "all" doesn't print these. */
8685 for (int signum
= 0; signum
< nsigs
; signum
++)
8688 signal_cache_update (-1);
8689 target_pass_signals (signal_pass
);
8690 target_program_signals (signal_program
);
8694 /* Show the results. */
8695 sig_print_header ();
8696 for (; signum
< nsigs
; signum
++)
8698 sig_print_info ((enum gdb_signal
) signum
);
8705 /* Complete the "handle" command. */
8708 handle_completer (struct cmd_list_element
*ignore
,
8709 completion_tracker
&tracker
,
8710 const char *text
, const char *word
)
8712 static const char * const keywords
[] =
8726 signal_completer (ignore
, tracker
, text
, word
);
8727 complete_on_enum (tracker
, keywords
, word
, word
);
8731 gdb_signal_from_command (int num
)
8733 if (num
>= 1 && num
<= 15)
8734 return (enum gdb_signal
) num
;
8735 error (_("Only signals 1-15 are valid as numeric signals.\n\
8736 Use \"info signals\" for a list of symbolic signals."));
8739 /* Print current contents of the tables set by the handle command.
8740 It is possible we should just be printing signals actually used
8741 by the current target (but for things to work right when switching
8742 targets, all signals should be in the signal tables). */
8745 info_signals_command (const char *signum_exp
, int from_tty
)
8747 enum gdb_signal oursig
;
8749 sig_print_header ();
8753 /* First see if this is a symbol name. */
8754 oursig
= gdb_signal_from_name (signum_exp
);
8755 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8757 /* No, try numeric. */
8759 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8761 sig_print_info (oursig
);
8765 printf_filtered ("\n");
8766 /* These ugly casts brought to you by the native VAX compiler. */
8767 for (oursig
= GDB_SIGNAL_FIRST
;
8768 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8769 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8773 if (oursig
!= GDB_SIGNAL_UNKNOWN
8774 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8775 sig_print_info (oursig
);
8778 printf_filtered (_("\nUse the \"handle\" command "
8779 "to change these tables.\n"));
8782 /* The $_siginfo convenience variable is a bit special. We don't know
8783 for sure the type of the value until we actually have a chance to
8784 fetch the data. The type can change depending on gdbarch, so it is
8785 also dependent on which thread you have selected.
8787 1. making $_siginfo be an internalvar that creates a new value on
8790 2. making the value of $_siginfo be an lval_computed value. */
8792 /* This function implements the lval_computed support for reading a
8796 siginfo_value_read (struct value
*v
)
8798 LONGEST transferred
;
8800 /* If we can access registers, so can we access $_siginfo. Likewise
8802 validate_registers_access ();
8805 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8807 value_contents_all_raw (v
),
8809 TYPE_LENGTH (value_type (v
)));
8811 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8812 error (_("Unable to read siginfo"));
8815 /* This function implements the lval_computed support for writing a
8819 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8821 LONGEST transferred
;
8823 /* If we can access registers, so can we access $_siginfo. Likewise
8825 validate_registers_access ();
8827 transferred
= target_write (current_top_target (),
8828 TARGET_OBJECT_SIGNAL_INFO
,
8830 value_contents_all_raw (fromval
),
8832 TYPE_LENGTH (value_type (fromval
)));
8834 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8835 error (_("Unable to write siginfo"));
8838 static const struct lval_funcs siginfo_value_funcs
=
8844 /* Return a new value with the correct type for the siginfo object of
8845 the current thread using architecture GDBARCH. Return a void value
8846 if there's no object available. */
8848 static struct value
*
8849 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8852 if (target_has_stack ()
8853 && inferior_ptid
!= null_ptid
8854 && gdbarch_get_siginfo_type_p (gdbarch
))
8856 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8858 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8861 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8865 /* infcall_suspend_state contains state about the program itself like its
8866 registers and any signal it received when it last stopped.
8867 This state must be restored regardless of how the inferior function call
8868 ends (either successfully, or after it hits a breakpoint or signal)
8869 if the program is to properly continue where it left off. */
8871 class infcall_suspend_state
8874 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8875 once the inferior function call has finished. */
8876 infcall_suspend_state (struct gdbarch
*gdbarch
,
8877 const struct thread_info
*tp
,
8878 struct regcache
*regcache
)
8879 : m_thread_suspend (tp
->suspend
),
8880 m_registers (new readonly_detached_regcache (*regcache
))
8882 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8884 if (gdbarch_get_siginfo_type_p (gdbarch
))
8886 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8887 size_t len
= TYPE_LENGTH (type
);
8889 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8891 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8892 siginfo_data
.get (), 0, len
) != len
)
8894 /* Errors ignored. */
8895 siginfo_data
.reset (nullptr);
8901 m_siginfo_gdbarch
= gdbarch
;
8902 m_siginfo_data
= std::move (siginfo_data
);
8906 /* Return a pointer to the stored register state. */
8908 readonly_detached_regcache
*registers () const
8910 return m_registers
.get ();
8913 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8915 void restore (struct gdbarch
*gdbarch
,
8916 struct thread_info
*tp
,
8917 struct regcache
*regcache
) const
8919 tp
->suspend
= m_thread_suspend
;
8921 if (m_siginfo_gdbarch
== gdbarch
)
8923 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8925 /* Errors ignored. */
8926 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8927 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8930 /* The inferior can be gone if the user types "print exit(0)"
8931 (and perhaps other times). */
8932 if (target_has_execution ())
8933 /* NB: The register write goes through to the target. */
8934 regcache
->restore (registers ());
8938 /* How the current thread stopped before the inferior function call was
8940 struct thread_suspend_state m_thread_suspend
;
8942 /* The registers before the inferior function call was executed. */
8943 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8945 /* Format of SIGINFO_DATA or NULL if it is not present. */
8946 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8948 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8949 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8950 content would be invalid. */
8951 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8954 infcall_suspend_state_up
8955 save_infcall_suspend_state ()
8957 struct thread_info
*tp
= inferior_thread ();
8958 struct regcache
*regcache
= get_current_regcache ();
8959 struct gdbarch
*gdbarch
= regcache
->arch ();
8961 infcall_suspend_state_up inf_state
8962 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8964 /* Having saved the current state, adjust the thread state, discarding
8965 any stop signal information. The stop signal is not useful when
8966 starting an inferior function call, and run_inferior_call will not use
8967 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8968 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8973 /* Restore inferior session state to INF_STATE. */
8976 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8978 struct thread_info
*tp
= inferior_thread ();
8979 struct regcache
*regcache
= get_current_regcache ();
8980 struct gdbarch
*gdbarch
= regcache
->arch ();
8982 inf_state
->restore (gdbarch
, tp
, regcache
);
8983 discard_infcall_suspend_state (inf_state
);
8987 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8992 readonly_detached_regcache
*
8993 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8995 return inf_state
->registers ();
8998 /* infcall_control_state contains state regarding gdb's control of the
8999 inferior itself like stepping control. It also contains session state like
9000 the user's currently selected frame. */
9002 struct infcall_control_state
9004 struct thread_control_state thread_control
;
9005 struct inferior_control_state inferior_control
;
9008 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9009 int stopped_by_random_signal
= 0;
9011 /* ID if the selected frame when the inferior function call was made. */
9012 struct frame_id selected_frame_id
{};
9015 /* Save all of the information associated with the inferior<==>gdb
9018 infcall_control_state_up
9019 save_infcall_control_state ()
9021 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9022 struct thread_info
*tp
= inferior_thread ();
9023 struct inferior
*inf
= current_inferior ();
9025 inf_status
->thread_control
= tp
->control
;
9026 inf_status
->inferior_control
= inf
->control
;
9028 tp
->control
.step_resume_breakpoint
= NULL
;
9029 tp
->control
.exception_resume_breakpoint
= NULL
;
9031 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9032 chain. If caller's caller is walking the chain, they'll be happier if we
9033 hand them back the original chain when restore_infcall_control_state is
9035 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9038 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9039 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9041 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9047 restore_selected_frame (const frame_id
&fid
)
9049 frame_info
*frame
= frame_find_by_id (fid
);
9051 /* If inf_status->selected_frame_id is NULL, there was no previously
9055 warning (_("Unable to restore previously selected frame."));
9059 select_frame (frame
);
9062 /* Restore inferior session state to INF_STATUS. */
9065 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9067 struct thread_info
*tp
= inferior_thread ();
9068 struct inferior
*inf
= current_inferior ();
9070 if (tp
->control
.step_resume_breakpoint
)
9071 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9073 if (tp
->control
.exception_resume_breakpoint
)
9074 tp
->control
.exception_resume_breakpoint
->disposition
9075 = disp_del_at_next_stop
;
9077 /* Handle the bpstat_copy of the chain. */
9078 bpstat_clear (&tp
->control
.stop_bpstat
);
9080 tp
->control
= inf_status
->thread_control
;
9081 inf
->control
= inf_status
->inferior_control
;
9084 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9085 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9087 if (target_has_stack ())
9089 /* The point of the try/catch is that if the stack is clobbered,
9090 walking the stack might encounter a garbage pointer and
9091 error() trying to dereference it. */
9094 restore_selected_frame (inf_status
->selected_frame_id
);
9096 catch (const gdb_exception_error
&ex
)
9098 exception_fprintf (gdb_stderr
, ex
,
9099 "Unable to restore previously selected frame:\n");
9100 /* Error in restoring the selected frame. Select the
9102 select_frame (get_current_frame ());
9110 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9112 if (inf_status
->thread_control
.step_resume_breakpoint
)
9113 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9114 = disp_del_at_next_stop
;
9116 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9117 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9118 = disp_del_at_next_stop
;
9120 /* See save_infcall_control_state for info on stop_bpstat. */
9121 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9129 clear_exit_convenience_vars (void)
9131 clear_internalvar (lookup_internalvar ("_exitsignal"));
9132 clear_internalvar (lookup_internalvar ("_exitcode"));
9136 /* User interface for reverse debugging:
9137 Set exec-direction / show exec-direction commands
9138 (returns error unless target implements to_set_exec_direction method). */
9140 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9141 static const char exec_forward
[] = "forward";
9142 static const char exec_reverse
[] = "reverse";
9143 static const char *exec_direction
= exec_forward
;
9144 static const char *const exec_direction_names
[] = {
9151 set_exec_direction_func (const char *args
, int from_tty
,
9152 struct cmd_list_element
*cmd
)
9154 if (target_can_execute_reverse ())
9156 if (!strcmp (exec_direction
, exec_forward
))
9157 execution_direction
= EXEC_FORWARD
;
9158 else if (!strcmp (exec_direction
, exec_reverse
))
9159 execution_direction
= EXEC_REVERSE
;
9163 exec_direction
= exec_forward
;
9164 error (_("Target does not support this operation."));
9169 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9170 struct cmd_list_element
*cmd
, const char *value
)
9172 switch (execution_direction
) {
9174 fprintf_filtered (out
, _("Forward.\n"));
9177 fprintf_filtered (out
, _("Reverse.\n"));
9180 internal_error (__FILE__
, __LINE__
,
9181 _("bogus execution_direction value: %d"),
9182 (int) execution_direction
);
9187 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9188 struct cmd_list_element
*c
, const char *value
)
9190 fprintf_filtered (file
, _("Resuming the execution of threads "
9191 "of all processes is %s.\n"), value
);
9194 /* Implementation of `siginfo' variable. */
9196 static const struct internalvar_funcs siginfo_funcs
=
9203 /* Callback for infrun's target events source. This is marked when a
9204 thread has a pending status to process. */
9207 infrun_async_inferior_event_handler (gdb_client_data data
)
9209 inferior_event_handler (INF_REG_EVENT
);
9216 /* Verify that when two threads with the same ptid exist (from two different
9217 targets) and one of them changes ptid, we only update inferior_ptid if
9218 it is appropriate. */
9221 infrun_thread_ptid_changed ()
9223 gdbarch
*arch
= current_inferior ()->gdbarch
;
9225 /* The thread which inferior_ptid represents changes ptid. */
9227 scoped_restore_current_pspace_and_thread restore
;
9229 scoped_mock_context
<test_target_ops
> target1 (arch
);
9230 scoped_mock_context
<test_target_ops
> target2 (arch
);
9231 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9233 ptid_t
old_ptid (111, 222);
9234 ptid_t
new_ptid (111, 333);
9236 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9237 target1
.mock_thread
.ptid
= old_ptid
;
9238 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9239 target2
.mock_thread
.ptid
= old_ptid
;
9241 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9242 set_current_inferior (&target1
.mock_inferior
);
9244 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9246 gdb_assert (inferior_ptid
== new_ptid
);
9249 /* A thread with the same ptid as inferior_ptid, but from another target,
9252 scoped_restore_current_pspace_and_thread restore
;
9254 scoped_mock_context
<test_target_ops
> target1 (arch
);
9255 scoped_mock_context
<test_target_ops
> target2 (arch
);
9256 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9258 ptid_t
old_ptid (111, 222);
9259 ptid_t
new_ptid (111, 333);
9261 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9262 target1
.mock_thread
.ptid
= old_ptid
;
9263 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9264 target2
.mock_thread
.ptid
= old_ptid
;
9266 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9267 set_current_inferior (&target2
.mock_inferior
);
9269 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9271 gdb_assert (inferior_ptid
== old_ptid
);
9275 } /* namespace selftests */
9277 #endif /* GDB_SELF_TEST */
9279 void _initialize_infrun ();
9281 _initialize_infrun ()
9283 struct cmd_list_element
*c
;
9285 /* Register extra event sources in the event loop. */
9286 infrun_async_inferior_event_token
9287 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9290 add_info ("signals", info_signals_command
, _("\
9291 What debugger does when program gets various signals.\n\
9292 Specify a signal as argument to print info on that signal only."));
9293 add_info_alias ("handle", "signals", 0);
9295 c
= add_com ("handle", class_run
, handle_command
, _("\
9296 Specify how to handle signals.\n\
9297 Usage: handle SIGNAL [ACTIONS]\n\
9298 Args are signals and actions to apply to those signals.\n\
9299 If no actions are specified, the current settings for the specified signals\n\
9300 will be displayed instead.\n\
9302 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9303 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9304 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9305 The special arg \"all\" is recognized to mean all signals except those\n\
9306 used by the debugger, typically SIGTRAP and SIGINT.\n\
9308 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9309 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9310 Stop means reenter debugger if this signal happens (implies print).\n\
9311 Print means print a message if this signal happens.\n\
9312 Pass means let program see this signal; otherwise program doesn't know.\n\
9313 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9314 Pass and Stop may be combined.\n\
9316 Multiple signals may be specified. Signal numbers and signal names\n\
9317 may be interspersed with actions, with the actions being performed for\n\
9318 all signals cumulatively specified."));
9319 set_cmd_completer (c
, handle_completer
);
9322 stop_command
= add_cmd ("stop", class_obscure
,
9323 not_just_help_class_command
, _("\
9324 There is no `stop' command, but you can set a hook on `stop'.\n\
9325 This allows you to set a list of commands to be run each time execution\n\
9326 of the program stops."), &cmdlist
);
9328 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9329 Set inferior debugging."), _("\
9330 Show inferior debugging."), _("\
9331 When non-zero, inferior specific debugging is enabled."),
9334 &setdebuglist
, &showdebuglist
);
9336 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9337 &debug_displaced
, _("\
9338 Set displaced stepping debugging."), _("\
9339 Show displaced stepping debugging."), _("\
9340 When non-zero, displaced stepping specific debugging is enabled."),
9342 show_debug_displaced
,
9343 &setdebuglist
, &showdebuglist
);
9345 add_setshow_boolean_cmd ("non-stop", no_class
,
9347 Set whether gdb controls the inferior in non-stop mode."), _("\
9348 Show whether gdb controls the inferior in non-stop mode."), _("\
9349 When debugging a multi-threaded program and this setting is\n\
9350 off (the default, also called all-stop mode), when one thread stops\n\
9351 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9352 all other threads in the program while you interact with the thread of\n\
9353 interest. When you continue or step a thread, you can allow the other\n\
9354 threads to run, or have them remain stopped, but while you inspect any\n\
9355 thread's state, all threads stop.\n\
9357 In non-stop mode, when one thread stops, other threads can continue\n\
9358 to run freely. You'll be able to step each thread independently,\n\
9359 leave it stopped or free to run as needed."),
9365 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9368 signal_print
[i
] = 1;
9369 signal_program
[i
] = 1;
9370 signal_catch
[i
] = 0;
9373 /* Signals caused by debugger's own actions should not be given to
9374 the program afterwards.
9376 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9377 explicitly specifies that it should be delivered to the target
9378 program. Typically, that would occur when a user is debugging a
9379 target monitor on a simulator: the target monitor sets a
9380 breakpoint; the simulator encounters this breakpoint and halts
9381 the simulation handing control to GDB; GDB, noting that the stop
9382 address doesn't map to any known breakpoint, returns control back
9383 to the simulator; the simulator then delivers the hardware
9384 equivalent of a GDB_SIGNAL_TRAP to the program being
9386 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9387 signal_program
[GDB_SIGNAL_INT
] = 0;
9389 /* Signals that are not errors should not normally enter the debugger. */
9390 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9391 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9392 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9393 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9394 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9395 signal_print
[GDB_SIGNAL_PROF
] = 0;
9396 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9397 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9398 signal_stop
[GDB_SIGNAL_IO
] = 0;
9399 signal_print
[GDB_SIGNAL_IO
] = 0;
9400 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9401 signal_print
[GDB_SIGNAL_POLL
] = 0;
9402 signal_stop
[GDB_SIGNAL_URG
] = 0;
9403 signal_print
[GDB_SIGNAL_URG
] = 0;
9404 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9405 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9406 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9407 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9409 /* These signals are used internally by user-level thread
9410 implementations. (See signal(5) on Solaris.) Like the above
9411 signals, a healthy program receives and handles them as part of
9412 its normal operation. */
9413 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9414 signal_print
[GDB_SIGNAL_LWP
] = 0;
9415 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9416 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9417 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9418 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9419 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9420 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9422 /* Update cached state. */
9423 signal_cache_update (-1);
9425 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9426 &stop_on_solib_events
, _("\
9427 Set stopping for shared library events."), _("\
9428 Show stopping for shared library events."), _("\
9429 If nonzero, gdb will give control to the user when the dynamic linker\n\
9430 notifies gdb of shared library events. The most common event of interest\n\
9431 to the user would be loading/unloading of a new library."),
9432 set_stop_on_solib_events
,
9433 show_stop_on_solib_events
,
9434 &setlist
, &showlist
);
9436 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9437 follow_fork_mode_kind_names
,
9438 &follow_fork_mode_string
, _("\
9439 Set debugger response to a program call of fork or vfork."), _("\
9440 Show debugger response to a program call of fork or vfork."), _("\
9441 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9442 parent - the original process is debugged after a fork\n\
9443 child - the new process is debugged after a fork\n\
9444 The unfollowed process will continue to run.\n\
9445 By default, the debugger will follow the parent process."),
9447 show_follow_fork_mode_string
,
9448 &setlist
, &showlist
);
9450 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9451 follow_exec_mode_names
,
9452 &follow_exec_mode_string
, _("\
9453 Set debugger response to a program call of exec."), _("\
9454 Show debugger response to a program call of exec."), _("\
9455 An exec call replaces the program image of a process.\n\
9457 follow-exec-mode can be:\n\
9459 new - the debugger creates a new inferior and rebinds the process\n\
9460 to this new inferior. The program the process was running before\n\
9461 the exec call can be restarted afterwards by restarting the original\n\
9464 same - the debugger keeps the process bound to the same inferior.\n\
9465 The new executable image replaces the previous executable loaded in\n\
9466 the inferior. Restarting the inferior after the exec call restarts\n\
9467 the executable the process was running after the exec call.\n\
9469 By default, the debugger will use the same inferior."),
9471 show_follow_exec_mode_string
,
9472 &setlist
, &showlist
);
9474 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9475 scheduler_enums
, &scheduler_mode
, _("\
9476 Set mode for locking scheduler during execution."), _("\
9477 Show mode for locking scheduler during execution."), _("\
9478 off == no locking (threads may preempt at any time)\n\
9479 on == full locking (no thread except the current thread may run)\n\
9480 This applies to both normal execution and replay mode.\n\
9481 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9482 In this mode, other threads may run during other commands.\n\
9483 This applies to both normal execution and replay mode.\n\
9484 replay == scheduler locked in replay mode and unlocked during normal execution."),
9485 set_schedlock_func
, /* traps on target vector */
9486 show_scheduler_mode
,
9487 &setlist
, &showlist
);
9489 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9490 Set mode for resuming threads of all processes."), _("\
9491 Show mode for resuming threads of all processes."), _("\
9492 When on, execution commands (such as 'continue' or 'next') resume all\n\
9493 threads of all processes. When off (which is the default), execution\n\
9494 commands only resume the threads of the current process. The set of\n\
9495 threads that are resumed is further refined by the scheduler-locking\n\
9496 mode (see help set scheduler-locking)."),
9498 show_schedule_multiple
,
9499 &setlist
, &showlist
);
9501 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9502 Set mode of the step operation."), _("\
9503 Show mode of the step operation."), _("\
9504 When set, doing a step over a function without debug line information\n\
9505 will stop at the first instruction of that function. Otherwise, the\n\
9506 function is skipped and the step command stops at a different source line."),
9508 show_step_stop_if_no_debug
,
9509 &setlist
, &showlist
);
9511 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9512 &can_use_displaced_stepping
, _("\
9513 Set debugger's willingness to use displaced stepping."), _("\
9514 Show debugger's willingness to use displaced stepping."), _("\
9515 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9516 supported by the target architecture. If off, gdb will not use displaced\n\
9517 stepping to step over breakpoints, even if such is supported by the target\n\
9518 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9519 if the target architecture supports it and non-stop mode is active, but will not\n\
9520 use it in all-stop mode (see help set non-stop)."),
9522 show_can_use_displaced_stepping
,
9523 &setlist
, &showlist
);
9525 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9526 &exec_direction
, _("Set direction of execution.\n\
9527 Options are 'forward' or 'reverse'."),
9528 _("Show direction of execution (forward/reverse)."),
9529 _("Tells gdb whether to execute forward or backward."),
9530 set_exec_direction_func
, show_exec_direction_func
,
9531 &setlist
, &showlist
);
9533 /* Set/show detach-on-fork: user-settable mode. */
9535 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9536 Set whether gdb will detach the child of a fork."), _("\
9537 Show whether gdb will detach the child of a fork."), _("\
9538 Tells gdb whether to detach the child of a fork."),
9539 NULL
, NULL
, &setlist
, &showlist
);
9541 /* Set/show disable address space randomization mode. */
9543 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9544 &disable_randomization
, _("\
9545 Set disabling of debuggee's virtual address space randomization."), _("\
9546 Show disabling of debuggee's virtual address space randomization."), _("\
9547 When this mode is on (which is the default), randomization of the virtual\n\
9548 address space is disabled. Standalone programs run with the randomization\n\
9549 enabled by default on some platforms."),
9550 &set_disable_randomization
,
9551 &show_disable_randomization
,
9552 &setlist
, &showlist
);
9554 /* ptid initializations */
9555 inferior_ptid
= null_ptid
;
9556 target_last_wait_ptid
= minus_one_ptid
;
9558 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9559 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9560 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9561 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9563 /* Explicitly create without lookup, since that tries to create a
9564 value with a void typed value, and when we get here, gdbarch
9565 isn't initialized yet. At this point, we're quite sure there
9566 isn't another convenience variable of the same name. */
9567 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9569 add_setshow_boolean_cmd ("observer", no_class
,
9570 &observer_mode_1
, _("\
9571 Set whether gdb controls the inferior in observer mode."), _("\
9572 Show whether gdb controls the inferior in observer mode."), _("\
9573 In observer mode, GDB can get data from the inferior, but not\n\
9574 affect its execution. Registers and memory may not be changed,\n\
9575 breakpoints may not be set, and the program cannot be interrupted\n\
9583 selftests::register_test ("infrun_thread_ptid_changed",
9584 selftests::infrun_thread_ptid_changed
);