1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
5 Copyright (C) 2019-2020 Advanced Micro Devices, Inc. All rights reserved.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
28 #include "breakpoint.h"
32 #include "target-connection.h"
33 #include "gdbthread.h"
40 #include "observable.h"
45 #include "mi/mi-common.h"
46 #include "event-top.h"
48 #include "record-full.h"
49 #include "inline-frame.h"
51 #include "tracepoint.h"
55 #include "completer.h"
56 #include "target-descriptions.h"
57 #include "target-dcache.h"
60 #include "event-loop.h"
61 #include "thread-fsm.h"
62 #include "gdbsupport/enum-flags.h"
63 #include "progspace-and-thread.h"
64 #include "gdbsupport/gdb_optional.h"
65 #include "arch-utils.h"
66 #include "gdbsupport/scope-exit.h"
67 #include "gdbsupport/forward-scope-exit.h"
68 #include "gdb_select.h"
69 #include <unordered_map>
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal
);
75 static void sig_print_header (void);
77 static int follow_fork (void);
79 static int follow_fork_inferior (int follow_child
, int detach_fork
);
81 static void follow_inferior_reset_breakpoints (void);
83 static int currently_stepping (struct thread_info
*tp
);
85 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
87 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
89 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
91 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
93 static void resume (gdb_signal sig
);
95 static void wait_for_inferior (inferior
*inf
);
97 /* Asynchronous signal handler registered as event loop source for
98 when we have pending events ready to be passed to the core. */
99 static struct async_event_handler
*infrun_async_inferior_event_token
;
101 /* Stores whether infrun_async was previously enabled or disabled.
102 Starts off as -1, indicating "never enabled/disabled". */
103 static int infrun_is_async
= -1;
108 infrun_async (int enable
)
110 if (infrun_is_async
!= enable
)
112 infrun_is_async
= enable
;
115 fprintf_unfiltered (gdb_stdlog
,
116 "infrun: infrun_async(%d)\n",
120 mark_async_event_handler (infrun_async_inferior_event_token
);
122 clear_async_event_handler (infrun_async_inferior_event_token
);
129 mark_infrun_async_event_handler (void)
131 mark_async_event_handler (infrun_async_inferior_event_token
);
134 /* When set, stop the 'step' command if we enter a function which has
135 no line number information. The normal behavior is that we step
136 over such function. */
137 bool step_stop_if_no_debug
= false;
139 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
140 struct cmd_list_element
*c
, const char *value
)
142 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
145 /* proceed and normal_stop use this to notify the user when the
146 inferior stopped in a different thread than it had been running
149 static ptid_t previous_inferior_ptid
;
151 /* If set (default for legacy reasons), when following a fork, GDB
152 will detach from one of the fork branches, child or parent.
153 Exactly which branch is detached depends on 'set follow-fork-mode'
156 static bool detach_fork
= true;
158 bool debug_displaced
= false;
160 show_debug_displaced (struct ui_file
*file
, int from_tty
,
161 struct cmd_list_element
*c
, const char *value
)
163 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
166 unsigned int debug_infrun
= 0;
168 show_debug_infrun (struct ui_file
*file
, int from_tty
,
169 struct cmd_list_element
*c
, const char *value
)
171 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
175 /* Support for disabling address space randomization. */
177 bool disable_randomization
= true;
180 show_disable_randomization (struct ui_file
*file
, int from_tty
,
181 struct cmd_list_element
*c
, const char *value
)
183 if (target_supports_disable_randomization ())
184 fprintf_filtered (file
,
185 _("Disabling randomization of debuggee's "
186 "virtual address space is %s.\n"),
189 fputs_filtered (_("Disabling randomization of debuggee's "
190 "virtual address space is unsupported on\n"
191 "this platform.\n"), file
);
195 set_disable_randomization (const char *args
, int from_tty
,
196 struct cmd_list_element
*c
)
198 if (!target_supports_disable_randomization ())
199 error (_("Disabling randomization of debuggee's "
200 "virtual address space is unsupported on\n"
204 /* User interface for non-stop mode. */
206 bool non_stop
= false;
207 static bool non_stop_1
= false;
210 set_non_stop (const char *args
, int from_tty
,
211 struct cmd_list_element
*c
)
213 if (target_has_execution
)
215 non_stop_1
= non_stop
;
216 error (_("Cannot change this setting while the inferior is running."));
219 non_stop
= non_stop_1
;
223 show_non_stop (struct ui_file
*file
, int from_tty
,
224 struct cmd_list_element
*c
, const char *value
)
226 fprintf_filtered (file
,
227 _("Controlling the inferior in non-stop mode is %s.\n"),
231 /* "Observer mode" is somewhat like a more extreme version of
232 non-stop, in which all GDB operations that might affect the
233 target's execution have been disabled. */
235 bool observer_mode
= false;
236 static bool observer_mode_1
= false;
239 set_observer_mode (const char *args
, int from_tty
,
240 struct cmd_list_element
*c
)
242 if (target_has_execution
)
244 observer_mode_1
= observer_mode
;
245 error (_("Cannot change this setting while the inferior is running."));
248 observer_mode
= observer_mode_1
;
250 may_write_registers
= !observer_mode
;
251 may_write_memory
= !observer_mode
;
252 may_insert_breakpoints
= !observer_mode
;
253 may_insert_tracepoints
= !observer_mode
;
254 /* We can insert fast tracepoints in or out of observer mode,
255 but enable them if we're going into this mode. */
257 may_insert_fast_tracepoints
= true;
258 may_stop
= !observer_mode
;
259 update_target_permissions ();
261 /* Going *into* observer mode we must force non-stop, then
262 going out we leave it that way. */
265 pagination_enabled
= 0;
266 non_stop
= non_stop_1
= true;
270 printf_filtered (_("Observer mode is now %s.\n"),
271 (observer_mode
? "on" : "off"));
275 show_observer_mode (struct ui_file
*file
, int from_tty
,
276 struct cmd_list_element
*c
, const char *value
)
278 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
281 /* This updates the value of observer mode based on changes in
282 permissions. Note that we are deliberately ignoring the values of
283 may-write-registers and may-write-memory, since the user may have
284 reason to enable these during a session, for instance to turn on a
285 debugging-related global. */
288 update_observer_mode (void)
290 bool newval
= (!may_insert_breakpoints
291 && !may_insert_tracepoints
292 && may_insert_fast_tracepoints
296 /* Let the user know if things change. */
297 if (newval
!= observer_mode
)
298 printf_filtered (_("Observer mode is now %s.\n"),
299 (newval
? "on" : "off"));
301 observer_mode
= observer_mode_1
= newval
;
304 /* Tables of how to react to signals; the user sets them. */
306 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
307 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
308 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
310 /* Table of signals that are registered with "catch signal". A
311 non-zero entry indicates that the signal is caught by some "catch
313 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
315 /* Table of signals that the target may silently handle.
316 This is automatically determined from the flags above,
317 and simply cached here. */
318 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
320 #define SET_SIGS(nsigs,sigs,flags) \
322 int signum = (nsigs); \
323 while (signum-- > 0) \
324 if ((sigs)[signum]) \
325 (flags)[signum] = 1; \
328 #define UNSET_SIGS(nsigs,sigs,flags) \
330 int signum = (nsigs); \
331 while (signum-- > 0) \
332 if ((sigs)[signum]) \
333 (flags)[signum] = 0; \
336 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
337 this function is to avoid exporting `signal_program'. */
340 update_signals_program_target (void)
342 target_program_signals (signal_program
);
345 /* Value to pass to target_resume() to cause all threads to resume. */
347 #define RESUME_ALL minus_one_ptid
349 /* Command list pointer for the "stop" placeholder. */
351 static struct cmd_list_element
*stop_command
;
353 /* Nonzero if we want to give control to the user when we're notified
354 of shared library events by the dynamic linker. */
355 int stop_on_solib_events
;
357 /* Enable or disable optional shared library event breakpoints
358 as appropriate when the above flag is changed. */
361 set_stop_on_solib_events (const char *args
,
362 int from_tty
, struct cmd_list_element
*c
)
364 update_solib_breakpoints ();
368 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
369 struct cmd_list_element
*c
, const char *value
)
371 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
375 /* Nonzero after stop if current stack frame should be printed. */
377 static int stop_print_frame
;
379 /* This is a cached copy of the target/ptid/waitstatus of the last
380 event returned by target_wait()/deprecated_target_wait_hook().
381 This information is returned by get_last_target_status(). */
382 static process_stratum_target
*target_last_proc_target
;
383 static ptid_t target_last_wait_ptid
;
384 static struct target_waitstatus target_last_waitstatus
;
386 void init_thread_stepping_state (struct thread_info
*tss
);
388 static const char follow_fork_mode_child
[] = "child";
389 static const char follow_fork_mode_parent
[] = "parent";
391 static const char *const follow_fork_mode_kind_names
[] = {
392 follow_fork_mode_child
,
393 follow_fork_mode_parent
,
397 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
399 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
400 struct cmd_list_element
*c
, const char *value
)
402 fprintf_filtered (file
,
403 _("Debugger response to a program "
404 "call of fork or vfork is \"%s\".\n"),
409 /* Handle changes to the inferior list based on the type of fork,
410 which process is being followed, and whether the other process
411 should be detached. On entry inferior_ptid must be the ptid of
412 the fork parent. At return inferior_ptid is the ptid of the
413 followed inferior. */
416 follow_fork_inferior (int follow_child
, int detach_fork
)
419 ptid_t parent_ptid
, child_ptid
;
421 has_vforked
= (inferior_thread ()->pending_follow
.kind
422 == TARGET_WAITKIND_VFORKED
);
423 parent_ptid
= inferior_ptid
;
424 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
427 && !non_stop
/* Non-stop always resumes both branches. */
428 && current_ui
->prompt_state
== PROMPT_BLOCKED
429 && !(follow_child
|| detach_fork
|| sched_multi
))
431 /* The parent stays blocked inside the vfork syscall until the
432 child execs or exits. If we don't let the child run, then
433 the parent stays blocked. If we're telling the parent to run
434 in the foreground, the user will not be able to ctrl-c to get
435 back the terminal, effectively hanging the debug session. */
436 fprintf_filtered (gdb_stderr
, _("\
437 Can not resume the parent process over vfork in the foreground while\n\
438 holding the child stopped. Try \"set detach-on-fork\" or \
439 \"set schedule-multiple\".\n"));
445 /* Detach new forked process? */
448 /* Before detaching from the child, remove all breakpoints
449 from it. If we forked, then this has already been taken
450 care of by infrun.c. If we vforked however, any
451 breakpoint inserted in the parent is visible in the
452 child, even those added while stopped in a vfork
453 catchpoint. This will remove the breakpoints from the
454 parent also, but they'll be reinserted below. */
457 /* Keep breakpoints list in sync. */
458 remove_breakpoints_inf (current_inferior ());
461 if (print_inferior_events
)
463 /* Ensure that we have a process ptid. */
464 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
466 target_terminal::ours_for_output ();
467 fprintf_filtered (gdb_stdlog
,
468 _("[Detaching after %s from child %s]\n"),
469 has_vforked
? "vfork" : "fork",
470 target_pid_to_str (process_ptid
).c_str ());
475 struct inferior
*parent_inf
, *child_inf
;
477 /* Add process to GDB's tables. */
478 child_inf
= add_inferior (child_ptid
.pid ());
480 parent_inf
= current_inferior ();
481 child_inf
->attach_flag
= parent_inf
->attach_flag
;
482 copy_terminal_info (child_inf
, parent_inf
);
483 child_inf
->gdbarch
= parent_inf
->gdbarch
;
484 copy_inferior_target_desc_info (child_inf
, parent_inf
);
486 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
488 set_current_inferior (child_inf
);
489 switch_to_no_thread ();
490 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
491 push_target (parent_inf
->process_target ());
492 add_thread_silent (child_inf
->process_target (), child_ptid
);
493 inferior_ptid
= child_ptid
;
495 /* If this is a vfork child, then the address-space is
496 shared with the parent. */
499 child_inf
->pspace
= parent_inf
->pspace
;
500 child_inf
->aspace
= parent_inf
->aspace
;
504 /* The parent will be frozen until the child is done
505 with the shared region. Keep track of the
507 child_inf
->vfork_parent
= parent_inf
;
508 child_inf
->pending_detach
= 0;
509 parent_inf
->vfork_child
= child_inf
;
510 parent_inf
->pending_detach
= 0;
514 child_inf
->aspace
= new_address_space ();
515 child_inf
->pspace
= new program_space (child_inf
->aspace
);
516 child_inf
->removable
= 1;
517 set_current_program_space (child_inf
->pspace
);
518 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
520 /* Let the shared library layer (e.g., solib-svr4) learn
521 about this new process, relocate the cloned exec, pull
522 in shared libraries, and install the solib event
523 breakpoint. If a "cloned-VM" event was propagated
524 better throughout the core, this wouldn't be
526 solib_create_inferior_hook (0);
532 struct inferior
*parent_inf
;
534 parent_inf
= current_inferior ();
536 /* If we detached from the child, then we have to be careful
537 to not insert breakpoints in the parent until the child
538 is done with the shared memory region. However, if we're
539 staying attached to the child, then we can and should
540 insert breakpoints, so that we can debug it. A
541 subsequent child exec or exit is enough to know when does
542 the child stops using the parent's address space. */
543 parent_inf
->waiting_for_vfork_done
= detach_fork
;
544 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
549 /* Follow the child. */
550 struct inferior
*parent_inf
, *child_inf
;
551 struct program_space
*parent_pspace
;
553 if (print_inferior_events
)
555 std::string parent_pid
= target_pid_to_str (parent_ptid
);
556 std::string child_pid
= target_pid_to_str (child_ptid
);
558 target_terminal::ours_for_output ();
559 fprintf_filtered (gdb_stdlog
,
560 _("[Attaching after %s %s to child %s]\n"),
562 has_vforked
? "vfork" : "fork",
566 /* Add the new inferior first, so that the target_detach below
567 doesn't unpush the target. */
569 child_inf
= add_inferior (child_ptid
.pid ());
571 parent_inf
= current_inferior ();
572 child_inf
->attach_flag
= parent_inf
->attach_flag
;
573 copy_terminal_info (child_inf
, parent_inf
);
574 child_inf
->gdbarch
= parent_inf
->gdbarch
;
575 copy_inferior_target_desc_info (child_inf
, parent_inf
);
577 parent_pspace
= parent_inf
->pspace
;
579 process_stratum_target
*target
= parent_inf
->process_target ();
582 /* Hold a strong reference to the target while (maybe)
583 detaching the parent. Otherwise detaching could close the
585 auto target_ref
= target_ops_ref::new_reference (target
);
587 /* If we're vforking, we want to hold on to the parent until
588 the child exits or execs. At child exec or exit time we
589 can remove the old breakpoints from the parent and detach
590 or resume debugging it. Otherwise, detach the parent now;
591 we'll want to reuse it's program/address spaces, but we
592 can't set them to the child before removing breakpoints
593 from the parent, otherwise, the breakpoints module could
594 decide to remove breakpoints from the wrong process (since
595 they'd be assigned to the same address space). */
599 gdb_assert (child_inf
->vfork_parent
== NULL
);
600 gdb_assert (parent_inf
->vfork_child
== NULL
);
601 child_inf
->vfork_parent
= parent_inf
;
602 child_inf
->pending_detach
= 0;
603 parent_inf
->vfork_child
= child_inf
;
604 parent_inf
->pending_detach
= detach_fork
;
605 parent_inf
->waiting_for_vfork_done
= 0;
607 else if (detach_fork
)
609 if (print_inferior_events
)
611 /* Ensure that we have a process ptid. */
612 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
614 target_terminal::ours_for_output ();
615 fprintf_filtered (gdb_stdlog
,
616 _("[Detaching after fork from "
618 target_pid_to_str (process_ptid
).c_str ());
621 target_detach (parent_inf
, 0);
625 /* Note that the detach above makes PARENT_INF dangling. */
627 /* Add the child thread to the appropriate lists, and switch
628 to this new thread, before cloning the program space, and
629 informing the solib layer about this new process. */
631 set_current_inferior (child_inf
);
632 push_target (target
);
635 add_thread_silent (target
, child_ptid
);
636 inferior_ptid
= child_ptid
;
638 /* If this is a vfork child, then the address-space is shared
639 with the parent. If we detached from the parent, then we can
640 reuse the parent's program/address spaces. */
641 if (has_vforked
|| detach_fork
)
643 child_inf
->pspace
= parent_pspace
;
644 child_inf
->aspace
= child_inf
->pspace
->aspace
;
650 child_inf
->aspace
= new_address_space ();
651 child_inf
->pspace
= new program_space (child_inf
->aspace
);
652 child_inf
->removable
= 1;
653 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
654 set_current_program_space (child_inf
->pspace
);
655 clone_program_space (child_inf
->pspace
, parent_pspace
);
657 /* Let the shared library layer (e.g., solib-svr4) learn
658 about this new process, relocate the cloned exec, pull in
659 shared libraries, and install the solib event breakpoint.
660 If a "cloned-VM" event was propagated better throughout
661 the core, this wouldn't be required. */
662 solib_create_inferior_hook (0);
666 return target_follow_fork (follow_child
, detach_fork
);
669 /* Tell the target to follow the fork we're stopped at. Returns true
670 if the inferior should be resumed; false, if the target for some
671 reason decided it's best not to resume. */
676 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
677 int should_resume
= 1;
678 struct thread_info
*tp
;
680 /* Copy user stepping state to the new inferior thread. FIXME: the
681 followed fork child thread should have a copy of most of the
682 parent thread structure's run control related fields, not just these.
683 Initialized to avoid "may be used uninitialized" warnings from gcc. */
684 struct breakpoint
*step_resume_breakpoint
= NULL
;
685 struct breakpoint
*exception_resume_breakpoint
= NULL
;
686 CORE_ADDR step_range_start
= 0;
687 CORE_ADDR step_range_end
= 0;
688 struct frame_id step_frame_id
= { 0 };
689 struct thread_fsm
*thread_fsm
= NULL
;
693 process_stratum_target
*wait_target
;
695 struct target_waitstatus wait_status
;
697 /* Get the last target status returned by target_wait(). */
698 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
700 /* If not stopped at a fork event, then there's nothing else to
702 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
703 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
706 /* Check if we switched over from WAIT_PTID, since the event was
708 if (wait_ptid
!= minus_one_ptid
709 && (current_inferior ()->process_target () != wait_target
710 || inferior_ptid
!= wait_ptid
))
712 /* We did. Switch back to WAIT_PTID thread, to tell the
713 target to follow it (in either direction). We'll
714 afterwards refuse to resume, and inform the user what
716 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
717 switch_to_thread (wait_thread
);
722 tp
= inferior_thread ();
724 /* If there were any forks/vforks that were caught and are now to be
725 followed, then do so now. */
726 switch (tp
->pending_follow
.kind
)
728 case TARGET_WAITKIND_FORKED
:
729 case TARGET_WAITKIND_VFORKED
:
731 ptid_t parent
, child
;
733 /* If the user did a next/step, etc, over a fork call,
734 preserve the stepping state in the fork child. */
735 if (follow_child
&& should_resume
)
737 step_resume_breakpoint
= clone_momentary_breakpoint
738 (tp
->control
.step_resume_breakpoint
);
739 step_range_start
= tp
->control
.step_range_start
;
740 step_range_end
= tp
->control
.step_range_end
;
741 step_frame_id
= tp
->control
.step_frame_id
;
742 exception_resume_breakpoint
743 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
744 thread_fsm
= tp
->thread_fsm
;
746 /* For now, delete the parent's sr breakpoint, otherwise,
747 parent/child sr breakpoints are considered duplicates,
748 and the child version will not be installed. Remove
749 this when the breakpoints module becomes aware of
750 inferiors and address spaces. */
751 delete_step_resume_breakpoint (tp
);
752 tp
->control
.step_range_start
= 0;
753 tp
->control
.step_range_end
= 0;
754 tp
->control
.step_frame_id
= null_frame_id
;
755 delete_exception_resume_breakpoint (tp
);
756 tp
->thread_fsm
= NULL
;
759 parent
= inferior_ptid
;
760 child
= tp
->pending_follow
.value
.related_pid
;
762 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
763 /* Set up inferior(s) as specified by the caller, and tell the
764 target to do whatever is necessary to follow either parent
766 if (follow_fork_inferior (follow_child
, detach_fork
))
768 /* Target refused to follow, or there's some other reason
769 we shouldn't resume. */
774 /* This pending follow fork event is now handled, one way
775 or another. The previous selected thread may be gone
776 from the lists by now, but if it is still around, need
777 to clear the pending follow request. */
778 tp
= find_thread_ptid (parent_targ
, parent
);
780 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
782 /* This makes sure we don't try to apply the "Switched
783 over from WAIT_PID" logic above. */
784 nullify_last_target_wait_ptid ();
786 /* If we followed the child, switch to it... */
789 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
790 switch_to_thread (child_thr
);
792 /* ... and preserve the stepping state, in case the
793 user was stepping over the fork call. */
796 tp
= inferior_thread ();
797 tp
->control
.step_resume_breakpoint
798 = step_resume_breakpoint
;
799 tp
->control
.step_range_start
= step_range_start
;
800 tp
->control
.step_range_end
= step_range_end
;
801 tp
->control
.step_frame_id
= step_frame_id
;
802 tp
->control
.exception_resume_breakpoint
803 = exception_resume_breakpoint
;
804 tp
->thread_fsm
= thread_fsm
;
808 /* If we get here, it was because we're trying to
809 resume from a fork catchpoint, but, the user
810 has switched threads away from the thread that
811 forked. In that case, the resume command
812 issued is most likely not applicable to the
813 child, so just warn, and refuse to resume. */
814 warning (_("Not resuming: switched threads "
815 "before following fork child."));
818 /* Reset breakpoints in the child as appropriate. */
819 follow_inferior_reset_breakpoints ();
824 case TARGET_WAITKIND_SPURIOUS
:
825 /* Nothing to follow. */
828 internal_error (__FILE__
, __LINE__
,
829 "Unexpected pending_follow.kind %d\n",
830 tp
->pending_follow
.kind
);
834 return should_resume
;
838 follow_inferior_reset_breakpoints (void)
840 struct thread_info
*tp
= inferior_thread ();
842 /* Was there a step_resume breakpoint? (There was if the user
843 did a "next" at the fork() call.) If so, explicitly reset its
844 thread number. Cloned step_resume breakpoints are disabled on
845 creation, so enable it here now that it is associated with the
848 step_resumes are a form of bp that are made to be per-thread.
849 Since we created the step_resume bp when the parent process
850 was being debugged, and now are switching to the child process,
851 from the breakpoint package's viewpoint, that's a switch of
852 "threads". We must update the bp's notion of which thread
853 it is for, or it'll be ignored when it triggers. */
855 if (tp
->control
.step_resume_breakpoint
)
857 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
858 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
861 /* Treat exception_resume breakpoints like step_resume breakpoints. */
862 if (tp
->control
.exception_resume_breakpoint
)
864 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
865 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
868 /* Reinsert all breakpoints in the child. The user may have set
869 breakpoints after catching the fork, in which case those
870 were never set in the child, but only in the parent. This makes
871 sure the inserted breakpoints match the breakpoint list. */
873 breakpoint_re_set ();
874 insert_breakpoints ();
877 /* The child has exited or execed: resume threads of the parent the
878 user wanted to be executing. */
881 proceed_after_vfork_done (struct thread_info
*thread
,
884 int pid
= * (int *) arg
;
886 if (thread
->ptid
.pid () == pid
887 && thread
->state
== THREAD_RUNNING
888 && !thread
->executing
889 && !thread
->stop_requested
890 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
893 fprintf_unfiltered (gdb_stdlog
,
894 "infrun: resuming vfork parent thread %s\n",
895 target_pid_to_str (thread
->ptid
).c_str ());
897 switch_to_thread (thread
);
898 clear_proceed_status (0);
899 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
905 /* Save/restore inferior_ptid, current program space and current
906 inferior. Only use this if the current context points at an exited
907 inferior (and therefore there's no current thread to save). */
908 class scoped_restore_exited_inferior
911 scoped_restore_exited_inferior ()
912 : m_saved_ptid (&inferior_ptid
)
916 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
917 scoped_restore_current_program_space m_pspace
;
918 scoped_restore_current_inferior m_inferior
;
921 /* Called whenever we notice an exec or exit event, to handle
922 detaching or resuming a vfork parent. */
925 handle_vfork_child_exec_or_exit (int exec
)
927 struct inferior
*inf
= current_inferior ();
929 if (inf
->vfork_parent
)
931 int resume_parent
= -1;
933 /* This exec or exit marks the end of the shared memory region
934 between the parent and the child. Break the bonds. */
935 inferior
*vfork_parent
= inf
->vfork_parent
;
936 inf
->vfork_parent
->vfork_child
= NULL
;
937 inf
->vfork_parent
= NULL
;
939 /* If the user wanted to detach from the parent, now is the
941 if (vfork_parent
->pending_detach
)
943 struct thread_info
*tp
;
944 struct program_space
*pspace
;
945 struct address_space
*aspace
;
947 /* follow-fork child, detach-on-fork on. */
949 vfork_parent
->pending_detach
= 0;
951 gdb::optional
<scoped_restore_exited_inferior
>
952 maybe_restore_inferior
;
953 gdb::optional
<scoped_restore_current_pspace_and_thread
>
954 maybe_restore_thread
;
956 /* If we're handling a child exit, then inferior_ptid points
957 at the inferior's pid, not to a thread. */
959 maybe_restore_inferior
.emplace ();
961 maybe_restore_thread
.emplace ();
963 /* We're letting loose of the parent. */
964 tp
= any_live_thread_of_inferior (vfork_parent
);
965 switch_to_thread (tp
);
967 /* We're about to detach from the parent, which implicitly
968 removes breakpoints from its address space. There's a
969 catch here: we want to reuse the spaces for the child,
970 but, parent/child are still sharing the pspace at this
971 point, although the exec in reality makes the kernel give
972 the child a fresh set of new pages. The problem here is
973 that the breakpoints module being unaware of this, would
974 likely chose the child process to write to the parent
975 address space. Swapping the child temporarily away from
976 the spaces has the desired effect. Yes, this is "sort
979 pspace
= inf
->pspace
;
980 aspace
= inf
->aspace
;
984 if (print_inferior_events
)
987 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
989 target_terminal::ours_for_output ();
993 fprintf_filtered (gdb_stdlog
,
994 _("[Detaching vfork parent %s "
995 "after child exec]\n"), pidstr
.c_str ());
999 fprintf_filtered (gdb_stdlog
,
1000 _("[Detaching vfork parent %s "
1001 "after child exit]\n"), pidstr
.c_str ());
1005 target_detach (vfork_parent
, 0);
1008 inf
->pspace
= pspace
;
1009 inf
->aspace
= aspace
;
1013 /* We're staying attached to the parent, so, really give the
1014 child a new address space. */
1015 inf
->pspace
= new program_space (maybe_new_address_space ());
1016 inf
->aspace
= inf
->pspace
->aspace
;
1018 set_current_program_space (inf
->pspace
);
1020 resume_parent
= vfork_parent
->pid
;
1024 struct program_space
*pspace
;
1026 /* If this is a vfork child exiting, then the pspace and
1027 aspaces were shared with the parent. Since we're
1028 reporting the process exit, we'll be mourning all that is
1029 found in the address space, and switching to null_ptid,
1030 preparing to start a new inferior. But, since we don't
1031 want to clobber the parent's address/program spaces, we
1032 go ahead and create a new one for this exiting
1035 /* Switch to null_ptid while running clone_program_space, so
1036 that clone_program_space doesn't want to read the
1037 selected frame of a dead process. */
1038 scoped_restore restore_ptid
1039 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1041 /* This inferior is dead, so avoid giving the breakpoints
1042 module the option to write through to it (cloning a
1043 program space resets breakpoints). */
1046 pspace
= new program_space (maybe_new_address_space ());
1047 set_current_program_space (pspace
);
1049 inf
->symfile_flags
= SYMFILE_NO_READ
;
1050 clone_program_space (pspace
, vfork_parent
->pspace
);
1051 inf
->pspace
= pspace
;
1052 inf
->aspace
= pspace
->aspace
;
1054 resume_parent
= vfork_parent
->pid
;
1057 gdb_assert (current_program_space
== inf
->pspace
);
1059 if (non_stop
&& resume_parent
!= -1)
1061 /* If the user wanted the parent to be running, let it go
1063 scoped_restore_current_thread restore_thread
;
1066 fprintf_unfiltered (gdb_stdlog
,
1067 "infrun: resuming vfork parent process %d\n",
1070 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1075 /* Enum strings for "set|show follow-exec-mode". */
1077 static const char follow_exec_mode_new
[] = "new";
1078 static const char follow_exec_mode_same
[] = "same";
1079 static const char *const follow_exec_mode_names
[] =
1081 follow_exec_mode_new
,
1082 follow_exec_mode_same
,
1086 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1088 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1089 struct cmd_list_element
*c
, const char *value
)
1091 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1094 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1097 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1099 struct inferior
*inf
= current_inferior ();
1100 int pid
= ptid
.pid ();
1101 ptid_t process_ptid
;
1103 /* Switch terminal for any messages produced e.g. by
1104 breakpoint_re_set. */
1105 target_terminal::ours_for_output ();
1107 /* This is an exec event that we actually wish to pay attention to.
1108 Refresh our symbol table to the newly exec'd program, remove any
1109 momentary bp's, etc.
1111 If there are breakpoints, they aren't really inserted now,
1112 since the exec() transformed our inferior into a fresh set
1115 We want to preserve symbolic breakpoints on the list, since
1116 we have hopes that they can be reset after the new a.out's
1117 symbol table is read.
1119 However, any "raw" breakpoints must be removed from the list
1120 (e.g., the solib bp's), since their address is probably invalid
1123 And, we DON'T want to call delete_breakpoints() here, since
1124 that may write the bp's "shadow contents" (the instruction
1125 value that was overwritten with a TRAP instruction). Since
1126 we now have a new a.out, those shadow contents aren't valid. */
1128 mark_breakpoints_out ();
1130 /* The target reports the exec event to the main thread, even if
1131 some other thread does the exec, and even if the main thread was
1132 stopped or already gone. We may still have non-leader threads of
1133 the process on our list. E.g., on targets that don't have thread
1134 exit events (like remote); or on native Linux in non-stop mode if
1135 there were only two threads in the inferior and the non-leader
1136 one is the one that execs (and nothing forces an update of the
1137 thread list up to here). When debugging remotely, it's best to
1138 avoid extra traffic, when possible, so avoid syncing the thread
1139 list with the target, and instead go ahead and delete all threads
1140 of the process but one that reported the event. Note this must
1141 be done before calling update_breakpoints_after_exec, as
1142 otherwise clearing the threads' resources would reference stale
1143 thread breakpoints -- it may have been one of these threads that
1144 stepped across the exec. We could just clear their stepping
1145 states, but as long as we're iterating, might as well delete
1146 them. Deleting them now rather than at the next user-visible
1147 stop provides a nicer sequence of events for user and MI
1149 for (thread_info
*th
: all_threads_safe ())
1150 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1153 /* We also need to clear any left over stale state for the
1154 leader/event thread. E.g., if there was any step-resume
1155 breakpoint or similar, it's gone now. We cannot truly
1156 step-to-next statement through an exec(). */
1157 thread_info
*th
= inferior_thread ();
1158 th
->control
.step_resume_breakpoint
= NULL
;
1159 th
->control
.exception_resume_breakpoint
= NULL
;
1160 th
->control
.single_step_breakpoints
= NULL
;
1161 th
->control
.step_range_start
= 0;
1162 th
->control
.step_range_end
= 0;
1164 /* The user may have had the main thread held stopped in the
1165 previous image (e.g., schedlock on, or non-stop). Release
1167 th
->stop_requested
= 0;
1169 update_breakpoints_after_exec ();
1171 /* What is this a.out's name? */
1172 process_ptid
= ptid_t (pid
);
1173 printf_unfiltered (_("%s is executing new program: %s\n"),
1174 target_pid_to_str (process_ptid
).c_str (),
1177 /* We've followed the inferior through an exec. Therefore, the
1178 inferior has essentially been killed & reborn. */
1180 breakpoint_init_inferior (inf_execd
);
1182 gdb::unique_xmalloc_ptr
<char> exec_file_host
1183 = exec_file_find (exec_file_target
, NULL
);
1185 /* If we were unable to map the executable target pathname onto a host
1186 pathname, tell the user that. Otherwise GDB's subsequent behavior
1187 is confusing. Maybe it would even be better to stop at this point
1188 so that the user can specify a file manually before continuing. */
1189 if (exec_file_host
== NULL
)
1190 warning (_("Could not load symbols for executable %s.\n"
1191 "Do you need \"set sysroot\"?"),
1194 /* Reset the shared library package. This ensures that we get a
1195 shlib event when the child reaches "_start", at which point the
1196 dld will have had a chance to initialize the child. */
1197 /* Also, loading a symbol file below may trigger symbol lookups, and
1198 we don't want those to be satisfied by the libraries of the
1199 previous incarnation of this process. */
1200 no_shared_libraries (NULL
, 0);
1202 if (follow_exec_mode_string
== follow_exec_mode_new
)
1204 /* The user wants to keep the old inferior and program spaces
1205 around. Create a new fresh one, and switch to it. */
1207 /* Do exit processing for the original inferior before setting the new
1208 inferior's pid. Having two inferiors with the same pid would confuse
1209 find_inferior_p(t)id. Transfer the terminal state and info from the
1210 old to the new inferior. */
1211 inf
= add_inferior_with_spaces ();
1212 swap_terminal_info (inf
, current_inferior ());
1213 exit_inferior_silent (current_inferior ());
1216 target_follow_exec (inf
, exec_file_target
);
1218 inferior
*org_inferior
= current_inferior ();
1219 switch_to_inferior_no_thread (inf
);
1220 push_target (org_inferior
->process_target ());
1221 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1222 switch_to_thread (thr
);
1226 /* The old description may no longer be fit for the new image.
1227 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1228 old description; we'll read a new one below. No need to do
1229 this on "follow-exec-mode new", as the old inferior stays
1230 around (its description is later cleared/refetched on
1232 target_clear_description ();
1235 gdb_assert (current_program_space
== inf
->pspace
);
1237 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1238 because the proper displacement for a PIE (Position Independent
1239 Executable) main symbol file will only be computed by
1240 solib_create_inferior_hook below. breakpoint_re_set would fail
1241 to insert the breakpoints with the zero displacement. */
1242 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1244 /* If the target can specify a description, read it. Must do this
1245 after flipping to the new executable (because the target supplied
1246 description must be compatible with the executable's
1247 architecture, and the old executable may e.g., be 32-bit, while
1248 the new one 64-bit), and before anything involving memory or
1250 target_find_description ();
1252 solib_create_inferior_hook (0);
1254 jit_inferior_created_hook ();
1256 breakpoint_re_set ();
1258 /* Reinsert all breakpoints. (Those which were symbolic have
1259 been reset to the proper address in the new a.out, thanks
1260 to symbol_file_command...). */
1261 insert_breakpoints ();
1263 /* The next resume of this inferior should bring it to the shlib
1264 startup breakpoints. (If the user had also set bp's on
1265 "main" from the old (parent) process, then they'll auto-
1266 matically get reset there in the new process.). */
1269 /* The queue of threads that need to do a step-over operation to get
1270 past e.g., a breakpoint. What technique is used to step over the
1271 breakpoint/watchpoint does not matter -- all threads end up in the
1272 same queue, to maintain rough temporal order of execution, in order
1273 to avoid starvation, otherwise, we could e.g., find ourselves
1274 constantly stepping the same couple threads past their breakpoints
1275 over and over, if the single-step finish fast enough. */
1276 struct thread_info
*step_over_queue_head
;
1278 /* Bit flags indicating what the thread needs to step over. */
1280 enum step_over_what_flag
1282 /* Step over a breakpoint. */
1283 STEP_OVER_BREAKPOINT
= 1,
1285 /* Step past a non-continuable watchpoint, in order to let the
1286 instruction execute so we can evaluate the watchpoint
1288 STEP_OVER_WATCHPOINT
= 2
1290 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1292 /* Info about an instruction that is being stepped over. */
1294 struct step_over_info
1296 /* If we're stepping past a breakpoint, this is the address space
1297 and address of the instruction the breakpoint is set at. We'll
1298 skip inserting all breakpoints here. Valid iff ASPACE is
1300 const address_space
*aspace
;
1303 /* The instruction being stepped over triggers a nonsteppable
1304 watchpoint. If true, we'll skip inserting watchpoints. */
1305 int nonsteppable_watchpoint_p
;
1307 /* The thread's global number. */
1311 /* The step-over info of the location that is being stepped over.
1313 Note that with async/breakpoint always-inserted mode, a user might
1314 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1315 being stepped over. As setting a new breakpoint inserts all
1316 breakpoints, we need to make sure the breakpoint being stepped over
1317 isn't inserted then. We do that by only clearing the step-over
1318 info when the step-over is actually finished (or aborted).
1320 Presently GDB can only step over one breakpoint at any given time.
1321 Given threads that can't run code in the same address space as the
1322 breakpoint's can't really miss the breakpoint, GDB could be taught
1323 to step-over at most one breakpoint per address space (so this info
1324 could move to the address space object if/when GDB is extended).
1325 The set of breakpoints being stepped over will normally be much
1326 smaller than the set of all breakpoints, so a flag in the
1327 breakpoint location structure would be wasteful. A separate list
1328 also saves complexity and run-time, as otherwise we'd have to go
1329 through all breakpoint locations clearing their flag whenever we
1330 start a new sequence. Similar considerations weigh against storing
1331 this info in the thread object. Plus, not all step overs actually
1332 have breakpoint locations -- e.g., stepping past a single-step
1333 breakpoint, or stepping to complete a non-continuable
1335 static struct step_over_info step_over_info
;
1337 /* Record the address of the breakpoint/instruction we're currently
1339 N.B. We record the aspace and address now, instead of say just the thread,
1340 because when we need the info later the thread may be running. */
1343 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1344 int nonsteppable_watchpoint_p
,
1347 step_over_info
.aspace
= aspace
;
1348 step_over_info
.address
= address
;
1349 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1350 step_over_info
.thread
= thread
;
1353 /* Called when we're not longer stepping over a breakpoint / an
1354 instruction, so all breakpoints are free to be (re)inserted. */
1357 clear_step_over_info (void)
1360 fprintf_unfiltered (gdb_stdlog
,
1361 "infrun: clear_step_over_info\n");
1362 step_over_info
.aspace
= NULL
;
1363 step_over_info
.address
= 0;
1364 step_over_info
.nonsteppable_watchpoint_p
= 0;
1365 step_over_info
.thread
= -1;
1371 stepping_past_instruction_at (struct address_space
*aspace
,
1374 return (step_over_info
.aspace
!= NULL
1375 && breakpoint_address_match (aspace
, address
,
1376 step_over_info
.aspace
,
1377 step_over_info
.address
));
1383 thread_is_stepping_over_breakpoint (int thread
)
1385 return (step_over_info
.thread
!= -1
1386 && thread
== step_over_info
.thread
);
1392 stepping_past_nonsteppable_watchpoint (void)
1394 return step_over_info
.nonsteppable_watchpoint_p
;
1397 /* Returns true if step-over info is valid. */
1400 step_over_info_valid_p (void)
1402 return (step_over_info
.aspace
!= NULL
1403 || stepping_past_nonsteppable_watchpoint ());
1407 /* Displaced stepping. */
1409 /* In non-stop debugging mode, we must take special care to manage
1410 breakpoints properly; in particular, the traditional strategy for
1411 stepping a thread past a breakpoint it has hit is unsuitable.
1412 'Displaced stepping' is a tactic for stepping one thread past a
1413 breakpoint it has hit while ensuring that other threads running
1414 concurrently will hit the breakpoint as they should.
1416 The traditional way to step a thread T off a breakpoint in a
1417 multi-threaded program in all-stop mode is as follows:
1419 a0) Initially, all threads are stopped, and breakpoints are not
1421 a1) We single-step T, leaving breakpoints uninserted.
1422 a2) We insert breakpoints, and resume all threads.
1424 In non-stop debugging, however, this strategy is unsuitable: we
1425 don't want to have to stop all threads in the system in order to
1426 continue or step T past a breakpoint. Instead, we use displaced
1429 n0) Initially, T is stopped, other threads are running, and
1430 breakpoints are inserted.
1431 n1) We copy the instruction "under" the breakpoint to a separate
1432 location, outside the main code stream, making any adjustments
1433 to the instruction, register, and memory state as directed by
1435 n2) We single-step T over the instruction at its new location.
1436 n3) We adjust the resulting register and memory state as directed
1437 by T's architecture. This includes resetting T's PC to point
1438 back into the main instruction stream.
1441 This approach depends on the following gdbarch methods:
1443 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1444 indicate where to copy the instruction, and how much space must
1445 be reserved there. We use these in step n1.
1447 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1448 address, and makes any necessary adjustments to the instruction,
1449 register contents, and memory. We use this in step n1.
1451 - gdbarch_displaced_step_fixup adjusts registers and memory after
1452 we have successfully single-stepped the instruction, to yield the
1453 same effect the instruction would have had if we had executed it
1454 at its original address. We use this in step n3.
1456 The gdbarch_displaced_step_copy_insn and
1457 gdbarch_displaced_step_fixup functions must be written so that
1458 copying an instruction with gdbarch_displaced_step_copy_insn,
1459 single-stepping across the copied instruction, and then applying
1460 gdbarch_displaced_insn_fixup should have the same effects on the
1461 thread's memory and registers as stepping the instruction in place
1462 would have. Exactly which responsibilities fall to the copy and
1463 which fall to the fixup is up to the author of those functions.
1465 See the comments in gdbarch.sh for details.
1467 Note that displaced stepping and software single-step cannot
1468 currently be used in combination, although with some care I think
1469 they could be made to. Software single-step works by placing
1470 breakpoints on all possible subsequent instructions; if the
1471 displaced instruction is a PC-relative jump, those breakpoints
1472 could fall in very strange places --- on pages that aren't
1473 executable, or at addresses that are not proper instruction
1474 boundaries. (We do generally let other threads run while we wait
1475 to hit the software single-step breakpoint, and they might
1476 encounter such a corrupted instruction.) One way to work around
1477 this would be to have gdbarch_displaced_step_copy_insn fully
1478 simulate the effect of PC-relative instructions (and return NULL)
1479 on architectures that use software single-stepping.
1481 In non-stop mode, we can have independent and simultaneous step
1482 requests, so more than one thread may need to simultaneously step
1483 over a breakpoint. The current implementation assumes there is
1484 only one scratch space per process. In this case, we have to
1485 serialize access to the scratch space. If thread A wants to step
1486 over a breakpoint, but we are currently waiting for some other
1487 thread to complete a displaced step, we leave thread A stopped and
1488 place it in the displaced_step_request_queue. Whenever a displaced
1489 step finishes, we pick the next thread in the queue and start a new
1490 displaced step operation on it. See displaced_step_prepare and
1491 displaced_step_fixup for details. */
1493 /* Default destructor for displaced_step_closure. */
1495 displaced_step_closure::~displaced_step_closure () = default;
1497 /* Get the displaced stepping state of process PID. */
1499 static displaced_step_inferior_state
*
1500 get_displaced_stepping_state (inferior
*inf
)
1502 return &inf
->displaced_step_state
;
1505 /* Returns true if any inferior has a thread doing a displaced
1509 displaced_step_in_progress_any_inferior ()
1511 for (inferior
*i
: all_inferiors ())
1513 if (i
->displaced_step_state
.step_thread
!= nullptr)
1520 /* Return true if thread represented by PTID is doing a displaced
1524 displaced_step_in_progress_thread (thread_info
*thread
)
1526 gdb_assert (thread
!= NULL
);
1528 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1531 /* Return true if process PID has a thread doing a displaced step. */
1534 displaced_step_in_progress (inferior
*inf
)
1536 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1539 /* If inferior is in displaced stepping, and ADDR equals to starting address
1540 of copy area, return corresponding displaced_step_closure. Otherwise,
1543 struct displaced_step_closure
*
1544 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1546 displaced_step_inferior_state
*displaced
1547 = get_displaced_stepping_state (current_inferior ());
1549 /* If checking the mode of displaced instruction in copy area. */
1550 if (displaced
->step_thread
!= nullptr
1551 && displaced
->step_copy
== addr
)
1552 return displaced
->step_closure
;
1558 infrun_inferior_exit (struct inferior
*inf
)
1560 inf
->displaced_step_state
.reset ();
1563 /* If ON, and the architecture supports it, GDB will use displaced
1564 stepping to step over breakpoints. If OFF, or if the architecture
1565 doesn't support it, GDB will instead use the traditional
1566 hold-and-step approach. If AUTO (which is the default), GDB will
1567 decide which technique to use to step over breakpoints depending on
1568 which of all-stop or non-stop mode is active --- displaced stepping
1569 in non-stop mode; hold-and-step in all-stop mode. */
1571 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1574 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1575 struct cmd_list_element
*c
,
1578 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1579 fprintf_filtered (file
,
1580 _("Debugger's willingness to use displaced stepping "
1581 "to step over breakpoints is %s (currently %s).\n"),
1582 value
, target_is_non_stop_p () ? "on" : "off");
1584 fprintf_filtered (file
,
1585 _("Debugger's willingness to use displaced stepping "
1586 "to step over breakpoints is %s.\n"), value
);
1589 /* Return non-zero if displaced stepping can/should be used to step
1590 over breakpoints of thread TP. */
1593 use_displaced_stepping (struct thread_info
*tp
)
1595 struct regcache
*regcache
= get_thread_regcache (tp
);
1596 struct gdbarch
*gdbarch
= regcache
->arch ();
1597 displaced_step_inferior_state
*displaced_state
1598 = get_displaced_stepping_state (tp
->inf
);
1600 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1601 && target_is_non_stop_p ())
1602 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1603 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1604 && find_record_target () == NULL
1605 && !displaced_state
->failed_before
);
1608 /* Clean out any stray displaced stepping state. */
1610 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1612 /* Indicate that there is no cleanup pending. */
1613 displaced
->step_thread
= nullptr;
1615 delete displaced
->step_closure
;
1616 displaced
->step_closure
= NULL
;
1619 /* A cleanup that wraps displaced_step_clear. */
1620 using displaced_step_clear_cleanup
1621 = FORWARD_SCOPE_EXIT (displaced_step_clear
);
1623 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1625 displaced_step_dump_bytes (struct ui_file
*file
,
1626 const gdb_byte
*buf
,
1631 for (i
= 0; i
< len
; i
++)
1632 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1633 fputs_unfiltered ("\n", file
);
1636 /* Prepare to single-step, using displaced stepping.
1638 Note that we cannot use displaced stepping when we have a signal to
1639 deliver. If we have a signal to deliver and an instruction to step
1640 over, then after the step, there will be no indication from the
1641 target whether the thread entered a signal handler or ignored the
1642 signal and stepped over the instruction successfully --- both cases
1643 result in a simple SIGTRAP. In the first case we mustn't do a
1644 fixup, and in the second case we must --- but we can't tell which.
1645 Comments in the code for 'random signals' in handle_inferior_event
1646 explain how we handle this case instead.
1648 Returns 1 if preparing was successful -- this thread is going to be
1649 stepped now; 0 if displaced stepping this thread got queued; or -1
1650 if this instruction can't be displaced stepped. */
1653 displaced_step_prepare_throw (thread_info
*tp
)
1655 regcache
*regcache
= get_thread_regcache (tp
);
1656 struct gdbarch
*gdbarch
= regcache
->arch ();
1657 const address_space
*aspace
= regcache
->aspace ();
1658 CORE_ADDR original
, copy
;
1660 struct displaced_step_closure
*closure
;
1663 /* We should never reach this function if the architecture does not
1664 support displaced stepping. */
1665 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1667 /* Nor if the thread isn't meant to step over a breakpoint. */
1668 gdb_assert (tp
->control
.trap_expected
);
1670 /* Disable range stepping while executing in the scratch pad. We
1671 want a single-step even if executing the displaced instruction in
1672 the scratch buffer lands within the stepping range (e.g., a
1674 tp
->control
.may_range_step
= 0;
1676 /* We have to displaced step one thread at a time, as we only have
1677 access to a single scratch space per inferior. */
1679 displaced_step_inferior_state
*displaced
1680 = get_displaced_stepping_state (tp
->inf
);
1682 if (displaced
->step_thread
!= nullptr)
1684 /* Already waiting for a displaced step to finish. Defer this
1685 request and place in queue. */
1687 if (debug_displaced
)
1688 fprintf_unfiltered (gdb_stdlog
,
1689 "displaced: deferring step of %s\n",
1690 target_pid_to_str (tp
->ptid
).c_str ());
1692 thread_step_over_chain_enqueue (tp
);
1697 if (debug_displaced
)
1698 fprintf_unfiltered (gdb_stdlog
,
1699 "displaced: stepping %s now\n",
1700 target_pid_to_str (tp
->ptid
).c_str ());
1703 displaced_step_clear (displaced
);
1705 scoped_restore_current_thread restore_thread
;
1707 switch_to_thread (tp
);
1709 original
= regcache_read_pc (regcache
);
1711 copy
= gdbarch_displaced_step_location (gdbarch
);
1712 len
= gdbarch_max_insn_length (gdbarch
);
1714 if (breakpoint_in_range_p (aspace
, copy
, len
))
1716 /* There's a breakpoint set in the scratch pad location range
1717 (which is usually around the entry point). We'd either
1718 install it before resuming, which would overwrite/corrupt the
1719 scratch pad, or if it was already inserted, this displaced
1720 step would overwrite it. The latter is OK in the sense that
1721 we already assume that no thread is going to execute the code
1722 in the scratch pad range (after initial startup) anyway, but
1723 the former is unacceptable. Simply punt and fallback to
1724 stepping over this breakpoint in-line. */
1725 if (debug_displaced
)
1727 fprintf_unfiltered (gdb_stdlog
,
1728 "displaced: breakpoint set in scratch pad. "
1729 "Stepping over breakpoint in-line instead.\n");
1735 /* Save the original contents of the copy area. */
1736 displaced
->step_saved_copy
.resize (len
);
1737 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1739 throw_error (MEMORY_ERROR
,
1740 _("Error accessing memory address %s (%s) for "
1741 "displaced-stepping scratch space."),
1742 paddress (gdbarch
, copy
), safe_strerror (status
));
1743 if (debug_displaced
)
1745 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1746 paddress (gdbarch
, copy
));
1747 displaced_step_dump_bytes (gdb_stdlog
,
1748 displaced
->step_saved_copy
.data (),
1752 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1753 original
, copy
, regcache
);
1754 if (closure
== NULL
)
1756 /* The architecture doesn't know how or want to displaced step
1757 this instruction or instruction sequence. Fallback to
1758 stepping over the breakpoint in-line. */
1762 /* Save the information we need to fix things up if the step
1764 displaced
->step_thread
= tp
;
1765 displaced
->step_gdbarch
= gdbarch
;
1766 displaced
->step_closure
= closure
;
1767 displaced
->step_original
= original
;
1768 displaced
->step_copy
= copy
;
1771 displaced_step_clear_cleanup
cleanup (displaced
);
1773 /* Resume execution at the copy. */
1774 regcache_write_pc (regcache
, copy
);
1779 if (debug_displaced
)
1780 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1781 paddress (gdbarch
, copy
));
1786 /* Wrapper for displaced_step_prepare_throw that disabled further
1787 attempts at displaced stepping if we get a memory error. */
1790 displaced_step_prepare (thread_info
*thread
)
1796 prepared
= displaced_step_prepare_throw (thread
);
1798 catch (const gdb_exception_error
&ex
)
1800 struct displaced_step_inferior_state
*displaced_state
;
1802 if (ex
.error
!= MEMORY_ERROR
1803 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1808 fprintf_unfiltered (gdb_stdlog
,
1809 "infrun: disabling displaced stepping: %s\n",
1813 /* Be verbose if "set displaced-stepping" is "on", silent if
1815 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1817 warning (_("disabling displaced stepping: %s"),
1821 /* Disable further displaced stepping attempts. */
1823 = get_displaced_stepping_state (thread
->inf
);
1824 displaced_state
->failed_before
= 1;
1831 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1832 const gdb_byte
*myaddr
, int len
)
1834 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1836 inferior_ptid
= ptid
;
1837 write_memory (memaddr
, myaddr
, len
);
1840 /* Restore the contents of the copy area for thread PTID. */
1843 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1846 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1848 write_memory_ptid (ptid
, displaced
->step_copy
,
1849 displaced
->step_saved_copy
.data (), len
);
1850 if (debug_displaced
)
1851 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1852 target_pid_to_str (ptid
).c_str (),
1853 paddress (displaced
->step_gdbarch
,
1854 displaced
->step_copy
));
1857 /* If we displaced stepped an instruction successfully, adjust
1858 registers and memory to yield the same effect the instruction would
1859 have had if we had executed it at its original address, and return
1860 1. If the instruction didn't complete, relocate the PC and return
1861 -1. If the thread wasn't displaced stepping, return 0. */
1864 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1866 struct displaced_step_inferior_state
*displaced
1867 = get_displaced_stepping_state (event_thread
->inf
);
1870 /* Was this event for the thread we displaced? */
1871 if (displaced
->step_thread
!= event_thread
)
1874 displaced_step_clear_cleanup
cleanup (displaced
);
1876 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
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. */
1881 switch_to_thread (event_thread
);
1883 /* Did the instruction complete successfully? */
1884 if (signal
== GDB_SIGNAL_TRAP
1885 && !(target_stopped_by_watchpoint ()
1886 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1887 || target_have_steppable_watchpoint
)))
1889 /* Fix up the resulting state. */
1890 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1891 displaced
->step_closure
,
1892 displaced
->step_original
,
1893 displaced
->step_copy
,
1894 get_thread_regcache (displaced
->step_thread
));
1899 /* Since the instruction didn't complete, all we can do is
1901 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1902 CORE_ADDR pc
= regcache_read_pc (regcache
);
1904 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1905 regcache_write_pc (regcache
, pc
);
1912 /* Data to be passed around while handling an event. This data is
1913 discarded between events. */
1914 struct execution_control_state
1916 process_stratum_target
*target
;
1918 /* The thread that got the event, if this was a thread event; NULL
1920 struct thread_info
*event_thread
;
1922 struct target_waitstatus ws
;
1923 int stop_func_filled_in
;
1924 CORE_ADDR stop_func_start
;
1925 CORE_ADDR stop_func_end
;
1926 const char *stop_func_name
;
1929 /* True if the event thread hit the single-step breakpoint of
1930 another thread. Thus the event doesn't cause a stop, the thread
1931 needs to be single-stepped past the single-step breakpoint before
1932 we can switch back to the original stepping thread. */
1933 int hit_singlestep_breakpoint
;
1936 /* Clear ECS and set it to point at TP. */
1939 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1941 memset (ecs
, 0, sizeof (*ecs
));
1942 ecs
->event_thread
= tp
;
1943 ecs
->ptid
= tp
->ptid
;
1946 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1947 static void prepare_to_wait (struct execution_control_state
*ecs
);
1948 static int keep_going_stepped_thread (struct thread_info
*tp
);
1949 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1951 /* Are there any pending step-over requests? If so, run all we can
1952 now and return true. Otherwise, return false. */
1955 start_step_over (void)
1957 struct thread_info
*tp
, *next
;
1959 /* Don't start a new step-over if we already have an in-line
1960 step-over operation ongoing. */
1961 if (step_over_info_valid_p ())
1964 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1966 struct execution_control_state ecss
;
1967 struct execution_control_state
*ecs
= &ecss
;
1968 step_over_what step_what
;
1969 int must_be_in_line
;
1971 gdb_assert (!tp
->stop_requested
);
1973 next
= thread_step_over_chain_next (tp
);
1975 /* If this inferior already has a displaced step in process,
1976 don't start a new one. */
1977 if (displaced_step_in_progress (tp
->inf
))
1980 step_what
= thread_still_needs_step_over (tp
);
1981 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1982 || ((step_what
& STEP_OVER_BREAKPOINT
)
1983 && !use_displaced_stepping (tp
)));
1985 /* We currently stop all threads of all processes to step-over
1986 in-line. If we need to start a new in-line step-over, let
1987 any pending displaced steps finish first. */
1988 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1991 thread_step_over_chain_remove (tp
);
1993 if (step_over_queue_head
== NULL
)
1996 fprintf_unfiltered (gdb_stdlog
,
1997 "infrun: step-over queue now empty\n");
2000 if (tp
->control
.trap_expected
2004 internal_error (__FILE__
, __LINE__
,
2005 "[%s] has inconsistent state: "
2006 "trap_expected=%d, resumed=%d, executing=%d\n",
2007 target_pid_to_str (tp
->ptid
).c_str (),
2008 tp
->control
.trap_expected
,
2014 fprintf_unfiltered (gdb_stdlog
,
2015 "infrun: resuming [%s] for step-over\n",
2016 target_pid_to_str (tp
->ptid
).c_str ());
2018 /* keep_going_pass_signal skips the step-over if the breakpoint
2019 is no longer inserted. In all-stop, we want to keep looking
2020 for a thread that needs a step-over instead of resuming TP,
2021 because we wouldn't be able to resume anything else until the
2022 target stops again. In non-stop, the resume always resumes
2023 only TP, so it's OK to let the thread resume freely. */
2024 if (!target_is_non_stop_p () && !step_what
)
2027 switch_to_thread (tp
);
2028 reset_ecs (ecs
, tp
);
2029 keep_going_pass_signal (ecs
);
2031 if (!ecs
->wait_some_more
)
2032 error (_("Command aborted."));
2034 gdb_assert (tp
->resumed
);
2036 /* If we started a new in-line step-over, we're done. */
2037 if (step_over_info_valid_p ())
2039 gdb_assert (tp
->control
.trap_expected
);
2043 if (!target_is_non_stop_p ())
2045 /* On all-stop, shouldn't have resumed unless we needed a
2047 gdb_assert (tp
->control
.trap_expected
2048 || tp
->step_after_step_resume_breakpoint
);
2050 /* With remote targets (at least), in all-stop, we can't
2051 issue any further remote commands until the program stops
2056 /* Either the thread no longer needed a step-over, or a new
2057 displaced stepping sequence started. Even in the latter
2058 case, continue looking. Maybe we can also start another
2059 displaced step on a thread of other process. */
2065 /* Update global variables holding ptids to hold NEW_PTID if they were
2066 holding OLD_PTID. */
2068 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2070 if (inferior_ptid
== old_ptid
)
2071 inferior_ptid
= new_ptid
;
2076 static const char schedlock_off
[] = "off";
2077 static const char schedlock_on
[] = "on";
2078 static const char schedlock_step
[] = "step";
2079 static const char schedlock_replay
[] = "replay";
2080 static const char *const scheduler_enums
[] = {
2087 static const char *scheduler_mode
= schedlock_replay
;
2089 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2090 struct cmd_list_element
*c
, const char *value
)
2092 fprintf_filtered (file
,
2093 _("Mode for locking scheduler "
2094 "during execution is \"%s\".\n"),
2099 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2101 if (!target_can_lock_scheduler
)
2103 scheduler_mode
= schedlock_off
;
2104 error (_("Target '%s' cannot support this command."), target_shortname
);
2108 /* True if execution commands resume all threads of all processes by
2109 default; otherwise, resume only threads of the current inferior
2111 bool sched_multi
= false;
2113 /* Try to setup for software single stepping over the specified location.
2114 Return 1 if target_resume() should use hardware single step.
2116 GDBARCH the current gdbarch.
2117 PC the location to step over. */
2120 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2124 if (execution_direction
== EXEC_FORWARD
2125 && gdbarch_software_single_step_p (gdbarch
))
2126 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2134 user_visible_resume_ptid (int step
)
2140 /* With non-stop mode on, threads are always handled
2142 resume_ptid
= inferior_ptid
;
2144 else if ((scheduler_mode
== schedlock_on
)
2145 || (scheduler_mode
== schedlock_step
&& step
))
2147 /* User-settable 'scheduler' mode requires solo thread
2149 resume_ptid
= inferior_ptid
;
2151 else if ((scheduler_mode
== schedlock_replay
)
2152 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2154 /* User-settable 'scheduler' mode requires solo thread resume in replay
2156 resume_ptid
= inferior_ptid
;
2158 else if (!sched_multi
&& target_supports_multi_process ())
2160 /* Resume all threads of the current process (and none of other
2162 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2166 /* Resume all threads of all processes. */
2167 resume_ptid
= RESUME_ALL
;
2175 process_stratum_target
*
2176 user_visible_resume_target (ptid_t resume_ptid
)
2178 return (resume_ptid
== minus_one_ptid
&& sched_multi
2180 : current_inferior ()->process_target ());
2183 /* Return a ptid representing the set of threads that we will resume,
2184 in the perspective of the target, assuming run control handling
2185 does not require leaving some threads stopped (e.g., stepping past
2186 breakpoint). USER_STEP indicates whether we're about to start the
2187 target for a stepping command. */
2190 internal_resume_ptid (int user_step
)
2192 /* In non-stop, we always control threads individually. Note that
2193 the target may always work in non-stop mode even with "set
2194 non-stop off", in which case user_visible_resume_ptid could
2195 return a wildcard ptid. */
2196 if (target_is_non_stop_p ())
2197 return inferior_ptid
;
2199 return user_visible_resume_ptid (user_step
);
2202 /* Wrapper for target_resume, that handles infrun-specific
2206 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2208 struct thread_info
*tp
= inferior_thread ();
2210 gdb_assert (!tp
->stop_requested
);
2212 /* Install inferior's terminal modes. */
2213 target_terminal::inferior ();
2215 /* Avoid confusing the next resume, if the next stop/resume
2216 happens to apply to another thread. */
2217 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2219 /* Advise target which signals may be handled silently.
2221 If we have removed breakpoints because we are stepping over one
2222 in-line (in any thread), we need to receive all signals to avoid
2223 accidentally skipping a breakpoint during execution of a signal
2226 Likewise if we're displaced stepping, otherwise a trap for a
2227 breakpoint in a signal handler might be confused with the
2228 displaced step finishing. We don't make the displaced_step_fixup
2229 step distinguish the cases instead, because:
2231 - a backtrace while stopped in the signal handler would show the
2232 scratch pad as frame older than the signal handler, instead of
2233 the real mainline code.
2235 - when the thread is later resumed, the signal handler would
2236 return to the scratch pad area, which would no longer be
2238 if (step_over_info_valid_p ()
2239 || displaced_step_in_progress (tp
->inf
))
2240 target_pass_signals ({});
2242 target_pass_signals (signal_pass
);
2244 target_resume (resume_ptid
, step
, sig
);
2246 target_commit_resume ();
2248 if (target_can_async_p ())
2252 /* Resume the inferior. SIG is the signal to give the inferior
2253 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2254 call 'resume', which handles exceptions. */
2257 resume_1 (enum gdb_signal sig
)
2259 struct regcache
*regcache
= get_current_regcache ();
2260 struct gdbarch
*gdbarch
= regcache
->arch ();
2261 struct thread_info
*tp
= inferior_thread ();
2262 CORE_ADDR pc
= regcache_read_pc (regcache
);
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
)
2283 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2285 fprintf_unfiltered (gdb_stdlog
,
2286 "infrun: resume: thread %s has pending wait "
2287 "status %s (currently_stepping=%d).\n",
2288 target_pid_to_str (tp
->ptid
).c_str (),
2290 currently_stepping (tp
));
2293 tp
->inf
->process_target ()->threads_executing
= true;
2296 /* FIXME: What should we do if we are supposed to resume this
2297 thread with a signal? Maybe we should maintain a queue of
2298 pending signals to deliver. */
2299 if (sig
!= GDB_SIGNAL_0
)
2301 warning (_("Couldn't deliver signal %s to %s."),
2302 gdb_signal_to_name (sig
),
2303 target_pid_to_str (tp
->ptid
).c_str ());
2306 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2308 if (target_can_async_p ())
2311 /* Tell the event loop we have an event to process. */
2312 mark_async_event_handler (infrun_async_inferior_event_token
);
2317 tp
->stepped_breakpoint
= 0;
2319 /* Depends on stepped_breakpoint. */
2320 step
= currently_stepping (tp
);
2322 if (current_inferior ()->waiting_for_vfork_done
)
2324 /* Don't try to single-step a vfork parent that is waiting for
2325 the child to get out of the shared memory region (by exec'ing
2326 or exiting). This is particularly important on software
2327 single-step archs, as the child process would trip on the
2328 software single step breakpoint inserted for the parent
2329 process. Since the parent will not actually execute any
2330 instruction until the child is out of the shared region (such
2331 are vfork's semantics), it is safe to simply continue it.
2332 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2333 the parent, and tell it to `keep_going', which automatically
2334 re-sets it stepping. */
2336 fprintf_unfiltered (gdb_stdlog
,
2337 "infrun: resume : clear step\n");
2342 fprintf_unfiltered (gdb_stdlog
,
2343 "infrun: resume (step=%d, signal=%s), "
2344 "trap_expected=%d, current thread [%s] at %s\n",
2345 step
, gdb_signal_to_symbol_string (sig
),
2346 tp
->control
.trap_expected
,
2347 target_pid_to_str (inferior_ptid
).c_str (),
2348 paddress (gdbarch
, pc
));
2350 /* Normally, by the time we reach `resume', the breakpoints are either
2351 removed or inserted, as appropriate. The exception is if we're sitting
2352 at a permanent breakpoint; we need to step over it, but permanent
2353 breakpoints can't be removed. So we have to test for it here. */
2354 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2356 if (sig
!= GDB_SIGNAL_0
)
2358 /* We have a signal to pass to the inferior. The resume
2359 may, or may not take us to the signal handler. If this
2360 is a step, we'll need to stop in the signal handler, if
2361 there's one, (if the target supports stepping into
2362 handlers), or in the next mainline instruction, if
2363 there's no handler. If this is a continue, we need to be
2364 sure to run the handler with all breakpoints inserted.
2365 In all cases, set a breakpoint at the current address
2366 (where the handler returns to), and once that breakpoint
2367 is hit, resume skipping the permanent breakpoint. If
2368 that breakpoint isn't hit, then we've stepped into the
2369 signal handler (or hit some other event). We'll delete
2370 the step-resume breakpoint then. */
2373 fprintf_unfiltered (gdb_stdlog
,
2374 "infrun: resume: skipping permanent breakpoint, "
2375 "deliver signal first\n");
2377 clear_step_over_info ();
2378 tp
->control
.trap_expected
= 0;
2380 if (tp
->control
.step_resume_breakpoint
== NULL
)
2382 /* Set a "high-priority" step-resume, as we don't want
2383 user breakpoints at PC to trigger (again) when this
2385 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2386 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2388 tp
->step_after_step_resume_breakpoint
= step
;
2391 insert_breakpoints ();
2395 /* There's no signal to pass, we can go ahead and skip the
2396 permanent breakpoint manually. */
2398 fprintf_unfiltered (gdb_stdlog
,
2399 "infrun: resume: skipping permanent breakpoint\n");
2400 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2401 /* Update pc to reflect the new address from which we will
2402 execute instructions. */
2403 pc
= regcache_read_pc (regcache
);
2407 /* We've already advanced the PC, so the stepping part
2408 is done. Now we need to arrange for a trap to be
2409 reported to handle_inferior_event. Set a breakpoint
2410 at the current PC, and run to it. Don't update
2411 prev_pc, because if we end in
2412 switch_back_to_stepped_thread, we want the "expected
2413 thread advanced also" branch to be taken. IOW, we
2414 don't want this thread to step further from PC
2416 gdb_assert (!step_over_info_valid_p ());
2417 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2418 insert_breakpoints ();
2420 resume_ptid
= internal_resume_ptid (user_step
);
2421 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2428 /* If we have a breakpoint to step over, make sure to do a single
2429 step only. Same if we have software watchpoints. */
2430 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2431 tp
->control
.may_range_step
= 0;
2433 /* If enabled, step over breakpoints by executing a copy of the
2434 instruction at a different address.
2436 We can't use displaced stepping when we have a signal to deliver;
2437 the comments for displaced_step_prepare explain why. The
2438 comments in the handle_inferior event for dealing with 'random
2439 signals' explain what we do instead.
2441 We can't use displaced stepping when we are waiting for vfork_done
2442 event, displaced stepping breaks the vfork child similarly as single
2443 step software breakpoint. */
2444 if (tp
->control
.trap_expected
2445 && use_displaced_stepping (tp
)
2446 && !step_over_info_valid_p ()
2447 && sig
== GDB_SIGNAL_0
2448 && !current_inferior ()->waiting_for_vfork_done
)
2450 int prepared
= displaced_step_prepare (tp
);
2455 fprintf_unfiltered (gdb_stdlog
,
2456 "Got placed in step-over queue\n");
2458 tp
->control
.trap_expected
= 0;
2461 else if (prepared
< 0)
2463 /* Fallback to stepping over the breakpoint in-line. */
2465 if (target_is_non_stop_p ())
2466 stop_all_threads ();
2468 set_step_over_info (regcache
->aspace (),
2469 regcache_read_pc (regcache
), 0, tp
->global_num
);
2471 step
= maybe_software_singlestep (gdbarch
, pc
);
2473 insert_breakpoints ();
2475 else if (prepared
> 0)
2477 struct displaced_step_inferior_state
*displaced
;
2479 /* Update pc to reflect the new address from which we will
2480 execute instructions due to displaced stepping. */
2481 pc
= regcache_read_pc (get_thread_regcache (tp
));
2483 displaced
= get_displaced_stepping_state (tp
->inf
);
2484 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2485 displaced
->step_closure
);
2489 /* Do we need to do it the hard way, w/temp breakpoints? */
2491 step
= maybe_software_singlestep (gdbarch
, pc
);
2493 /* Currently, our software single-step implementation leads to different
2494 results than hardware single-stepping in one situation: when stepping
2495 into delivering a signal which has an associated signal handler,
2496 hardware single-step will stop at the first instruction of the handler,
2497 while software single-step will simply skip execution of the handler.
2499 For now, this difference in behavior is accepted since there is no
2500 easy way to actually implement single-stepping into a signal handler
2501 without kernel support.
2503 However, there is one scenario where this difference leads to follow-on
2504 problems: if we're stepping off a breakpoint by removing all breakpoints
2505 and then single-stepping. In this case, the software single-step
2506 behavior means that even if there is a *breakpoint* in the signal
2507 handler, GDB still would not stop.
2509 Fortunately, we can at least fix this particular issue. We detect
2510 here the case where we are about to deliver a signal while software
2511 single-stepping with breakpoints removed. In this situation, we
2512 revert the decisions to remove all breakpoints and insert single-
2513 step breakpoints, and instead we install a step-resume breakpoint
2514 at the current address, deliver the signal without stepping, and
2515 once we arrive back at the step-resume breakpoint, actually step
2516 over the breakpoint we originally wanted to step over. */
2517 if (thread_has_single_step_breakpoints_set (tp
)
2518 && sig
!= GDB_SIGNAL_0
2519 && step_over_info_valid_p ())
2521 /* If we have nested signals or a pending signal is delivered
2522 immediately after a handler returns, might might already have
2523 a step-resume breakpoint set on the earlier handler. We cannot
2524 set another step-resume breakpoint; just continue on until the
2525 original breakpoint is hit. */
2526 if (tp
->control
.step_resume_breakpoint
== NULL
)
2528 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2529 tp
->step_after_step_resume_breakpoint
= 1;
2532 delete_single_step_breakpoints (tp
);
2534 clear_step_over_info ();
2535 tp
->control
.trap_expected
= 0;
2537 insert_breakpoints ();
2540 /* If STEP is set, it's a request to use hardware stepping
2541 facilities. But in that case, we should never
2542 use singlestep breakpoint. */
2543 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2545 /* Decide the set of threads to ask the target to resume. */
2546 if (tp
->control
.trap_expected
)
2548 /* We're allowing a thread to run past a breakpoint it has
2549 hit, either by single-stepping the thread with the breakpoint
2550 removed, or by displaced stepping, with the breakpoint inserted.
2551 In the former case, we need to single-step only this thread,
2552 and keep others stopped, as they can miss this breakpoint if
2553 allowed to run. That's not really a problem for displaced
2554 stepping, but, we still keep other threads stopped, in case
2555 another thread is also stopped for a breakpoint waiting for
2556 its turn in the displaced stepping queue. */
2557 resume_ptid
= inferior_ptid
;
2560 resume_ptid
= internal_resume_ptid (user_step
);
2562 if (execution_direction
!= EXEC_REVERSE
2563 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2565 /* There are two cases where we currently need to step a
2566 breakpoint instruction when we have a signal to deliver:
2568 - See handle_signal_stop where we handle random signals that
2569 could take out us out of the stepping range. Normally, in
2570 that case we end up continuing (instead of stepping) over the
2571 signal handler with a breakpoint at PC, but there are cases
2572 where we should _always_ single-step, even if we have a
2573 step-resume breakpoint, like when a software watchpoint is
2574 set. Assuming single-stepping and delivering a signal at the
2575 same time would takes us to the signal handler, then we could
2576 have removed the breakpoint at PC to step over it. However,
2577 some hardware step targets (like e.g., Mac OS) can't step
2578 into signal handlers, and for those, we need to leave the
2579 breakpoint at PC inserted, as otherwise if the handler
2580 recurses and executes PC again, it'll miss the breakpoint.
2581 So we leave the breakpoint inserted anyway, but we need to
2582 record that we tried to step a breakpoint instruction, so
2583 that adjust_pc_after_break doesn't end up confused.
2585 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2586 in one thread after another thread that was stepping had been
2587 momentarily paused for a step-over. When we re-resume the
2588 stepping thread, it may be resumed from that address with a
2589 breakpoint that hasn't trapped yet. Seen with
2590 gdb.threads/non-stop-fair-events.exp, on targets that don't
2591 do displaced stepping. */
2594 fprintf_unfiltered (gdb_stdlog
,
2595 "infrun: resume: [%s] stepped breakpoint\n",
2596 target_pid_to_str (tp
->ptid
).c_str ());
2598 tp
->stepped_breakpoint
= 1;
2600 /* Most targets can step a breakpoint instruction, thus
2601 executing it normally. But if this one cannot, just
2602 continue and we will hit it anyway. */
2603 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2608 && tp
->control
.trap_expected
2609 && use_displaced_stepping (tp
)
2610 && !step_over_info_valid_p ())
2612 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2613 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2614 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2617 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2618 paddress (resume_gdbarch
, actual_pc
));
2619 read_memory (actual_pc
, buf
, sizeof (buf
));
2620 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2623 if (tp
->control
.may_range_step
)
2625 /* If we're resuming a thread with the PC out of the step
2626 range, then we're doing some nested/finer run control
2627 operation, like stepping the thread out of the dynamic
2628 linker or the displaced stepping scratch pad. We
2629 shouldn't have allowed a range step then. */
2630 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2633 do_target_resume (resume_ptid
, step
, sig
);
2637 /* Resume the inferior. SIG is the signal to give the inferior
2638 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2639 rolls back state on error. */
2642 resume (gdb_signal sig
)
2648 catch (const gdb_exception
&ex
)
2650 /* If resuming is being aborted for any reason, delete any
2651 single-step breakpoint resume_1 may have created, to avoid
2652 confusing the following resumption, and to avoid leaving
2653 single-step breakpoints perturbing other threads, in case
2654 we're running in non-stop mode. */
2655 if (inferior_ptid
!= null_ptid
)
2656 delete_single_step_breakpoints (inferior_thread ());
2666 /* Counter that tracks number of user visible stops. This can be used
2667 to tell whether a command has proceeded the inferior past the
2668 current location. This allows e.g., inferior function calls in
2669 breakpoint commands to not interrupt the command list. When the
2670 call finishes successfully, the inferior is standing at the same
2671 breakpoint as if nothing happened (and so we don't call
2673 static ULONGEST current_stop_id
;
2680 return current_stop_id
;
2683 /* Called when we report a user visible stop. */
2691 /* Clear out all variables saying what to do when inferior is continued.
2692 First do this, then set the ones you want, then call `proceed'. */
2695 clear_proceed_status_thread (struct thread_info
*tp
)
2698 fprintf_unfiltered (gdb_stdlog
,
2699 "infrun: clear_proceed_status_thread (%s)\n",
2700 target_pid_to_str (tp
->ptid
).c_str ());
2702 /* If we're starting a new sequence, then the previous finished
2703 single-step is no longer relevant. */
2704 if (tp
->suspend
.waitstatus_pending_p
)
2706 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2709 fprintf_unfiltered (gdb_stdlog
,
2710 "infrun: clear_proceed_status: pending "
2711 "event of %s was a finished step. "
2713 target_pid_to_str (tp
->ptid
).c_str ());
2715 tp
->suspend
.waitstatus_pending_p
= 0;
2716 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2718 else if (debug_infrun
)
2721 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2723 fprintf_unfiltered (gdb_stdlog
,
2724 "infrun: clear_proceed_status_thread: thread %s "
2725 "has pending wait status %s "
2726 "(currently_stepping=%d).\n",
2727 target_pid_to_str (tp
->ptid
).c_str (),
2729 currently_stepping (tp
));
2733 /* If this signal should not be seen by program, give it zero.
2734 Used for debugging signals. */
2735 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2736 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2738 delete tp
->thread_fsm
;
2739 tp
->thread_fsm
= NULL
;
2741 tp
->control
.trap_expected
= 0;
2742 tp
->control
.step_range_start
= 0;
2743 tp
->control
.step_range_end
= 0;
2744 tp
->control
.may_range_step
= 0;
2745 tp
->control
.step_frame_id
= null_frame_id
;
2746 tp
->control
.step_stack_frame_id
= null_frame_id
;
2747 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2748 tp
->control
.step_start_function
= NULL
;
2749 tp
->stop_requested
= 0;
2751 tp
->control
.stop_step
= 0;
2753 tp
->control
.proceed_to_finish
= 0;
2755 tp
->control
.stepping_command
= 0;
2757 /* Discard any remaining commands or status from previous stop. */
2758 bpstat_clear (&tp
->control
.stop_bpstat
);
2762 clear_proceed_status (int step
)
2764 /* With scheduler-locking replay, stop replaying other threads if we're
2765 not replaying the user-visible resume ptid.
2767 This is a convenience feature to not require the user to explicitly
2768 stop replaying the other threads. We're assuming that the user's
2769 intent is to resume tracing the recorded process. */
2770 if (!non_stop
&& scheduler_mode
== schedlock_replay
2771 && target_record_is_replaying (minus_one_ptid
)
2772 && !target_record_will_replay (user_visible_resume_ptid (step
),
2773 execution_direction
))
2774 target_record_stop_replaying ();
2776 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2778 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2779 process_stratum_target
*resume_target
2780 = user_visible_resume_target (resume_ptid
);
2782 /* In all-stop mode, delete the per-thread status of all threads
2783 we're about to resume, implicitly and explicitly. */
2784 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2785 clear_proceed_status_thread (tp
);
2788 if (inferior_ptid
!= null_ptid
)
2790 struct inferior
*inferior
;
2794 /* If in non-stop mode, only delete the per-thread status of
2795 the current thread. */
2796 clear_proceed_status_thread (inferior_thread ());
2799 inferior
= current_inferior ();
2800 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2803 gdb::observers::about_to_proceed
.notify ();
2806 /* Returns true if TP is still stopped at a breakpoint that needs
2807 stepping-over in order to make progress. If the breakpoint is gone
2808 meanwhile, we can skip the whole step-over dance. */
2811 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2813 if (tp
->stepping_over_breakpoint
)
2815 struct regcache
*regcache
= get_thread_regcache (tp
);
2817 if (breakpoint_here_p (regcache
->aspace (),
2818 regcache_read_pc (regcache
))
2819 == ordinary_breakpoint_here
)
2822 tp
->stepping_over_breakpoint
= 0;
2828 /* Check whether thread TP still needs to start a step-over in order
2829 to make progress when resumed. Returns an bitwise or of enum
2830 step_over_what bits, indicating what needs to be stepped over. */
2832 static step_over_what
2833 thread_still_needs_step_over (struct thread_info
*tp
)
2835 step_over_what what
= 0;
2837 if (thread_still_needs_step_over_bp (tp
))
2838 what
|= STEP_OVER_BREAKPOINT
;
2840 if (tp
->stepping_over_watchpoint
2841 && !target_have_steppable_watchpoint
)
2842 what
|= STEP_OVER_WATCHPOINT
;
2847 /* Returns true if scheduler locking applies. STEP indicates whether
2848 we're about to do a step/next-like command to a thread. */
2851 schedlock_applies (struct thread_info
*tp
)
2853 return (scheduler_mode
== schedlock_on
2854 || (scheduler_mode
== schedlock_step
2855 && tp
->control
.stepping_command
)
2856 || (scheduler_mode
== schedlock_replay
2857 && target_record_will_replay (minus_one_ptid
,
2858 execution_direction
)));
2861 /* Calls target_commit_resume on all targets. */
2864 commit_resume_all_targets ()
2866 scoped_restore_current_thread restore_thread
;
2868 /* Map between process_target and a representative inferior. This
2869 is to avoid committing a resume in the same target more than
2870 once. Resumptions must be idempotent, so this is an
2872 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2874 for (inferior
*inf
: all_non_exited_inferiors ())
2875 if (inf
->has_execution ())
2876 conn_inf
[inf
->process_target ()] = inf
;
2878 for (const auto &ci
: conn_inf
)
2880 inferior
*inf
= ci
.second
;
2881 switch_to_inferior_no_thread (inf
);
2882 target_commit_resume ();
2886 /* Check that all the targets we're about to resume are in non-stop
2887 mode. Ideally, we'd only care whether all targets support
2888 target-async, but we're not there yet. E.g., stop_all_threads
2889 doesn't know how to handle all-stop targets. Also, the remote
2890 protocol in all-stop mode is synchronous, irrespective of
2891 target-async, which means that things like a breakpoint re-set
2892 triggered by one target would try to read memory from all targets
2896 check_multi_target_resumption (process_stratum_target
*resume_target
)
2898 if (!non_stop
&& resume_target
== nullptr)
2900 scoped_restore_current_thread restore_thread
;
2902 /* This is used to track whether we're resuming more than one
2904 process_stratum_target
*first_connection
= nullptr;
2906 /* The first inferior we see with a target that does not work in
2907 always-non-stop mode. */
2908 inferior
*first_not_non_stop
= nullptr;
2910 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2912 switch_to_inferior_no_thread (inf
);
2914 if (!target_has_execution
)
2917 process_stratum_target
*proc_target
2918 = current_inferior ()->process_target();
2920 if (!target_is_non_stop_p ())
2921 first_not_non_stop
= inf
;
2923 if (first_connection
== nullptr)
2924 first_connection
= proc_target
;
2925 else if (first_connection
!= proc_target
2926 && first_not_non_stop
!= nullptr)
2928 switch_to_inferior_no_thread (first_not_non_stop
);
2930 proc_target
= current_inferior ()->process_target();
2932 error (_("Connection %d (%s) does not support "
2933 "multi-target resumption."),
2934 proc_target
->connection_number
,
2935 make_target_connection_string (proc_target
).c_str ());
2941 /* Basic routine for continuing the program in various fashions.
2943 ADDR is the address to resume at, or -1 for resume where stopped.
2944 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2945 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2947 You should call clear_proceed_status before calling proceed. */
2950 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2952 struct regcache
*regcache
;
2953 struct gdbarch
*gdbarch
;
2955 struct execution_control_state ecss
;
2956 struct execution_control_state
*ecs
= &ecss
;
2959 /* If we're stopped at a fork/vfork, follow the branch set by the
2960 "set follow-fork-mode" command; otherwise, we'll just proceed
2961 resuming the current thread. */
2962 if (!follow_fork ())
2964 /* The target for some reason decided not to resume. */
2966 if (target_can_async_p ())
2967 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2971 /* We'll update this if & when we switch to a new thread. */
2972 previous_inferior_ptid
= inferior_ptid
;
2974 regcache
= get_current_regcache ();
2975 gdbarch
= regcache
->arch ();
2976 const address_space
*aspace
= regcache
->aspace ();
2978 pc
= regcache_read_pc (regcache
);
2979 thread_info
*cur_thr
= inferior_thread ();
2981 /* Fill in with reasonable starting values. */
2982 init_thread_stepping_state (cur_thr
);
2984 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2987 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2988 process_stratum_target
*resume_target
2989 = user_visible_resume_target (resume_ptid
);
2991 check_multi_target_resumption (resume_target
);
2993 if (addr
== (CORE_ADDR
) -1)
2995 if (pc
== cur_thr
->suspend
.stop_pc
2996 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2997 && execution_direction
!= EXEC_REVERSE
)
2998 /* There is a breakpoint at the address we will resume at,
2999 step one instruction before inserting breakpoints so that
3000 we do not stop right away (and report a second hit at this
3003 Note, we don't do this in reverse, because we won't
3004 actually be executing the breakpoint insn anyway.
3005 We'll be (un-)executing the previous instruction. */
3006 cur_thr
->stepping_over_breakpoint
= 1;
3007 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3008 && gdbarch_single_step_through_delay (gdbarch
,
3009 get_current_frame ()))
3010 /* We stepped onto an instruction that needs to be stepped
3011 again before re-inserting the breakpoint, do so. */
3012 cur_thr
->stepping_over_breakpoint
= 1;
3016 regcache_write_pc (regcache
, addr
);
3019 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3020 cur_thr
->suspend
.stop_signal
= siggnal
;
3022 /* If an exception is thrown from this point on, make sure to
3023 propagate GDB's knowledge of the executing state to the
3024 frontend/user running state. */
3025 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3027 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3028 threads (e.g., we might need to set threads stepping over
3029 breakpoints first), from the user/frontend's point of view, all
3030 threads in RESUME_PTID are now running. Unless we're calling an
3031 inferior function, as in that case we pretend the inferior
3032 doesn't run at all. */
3033 if (!cur_thr
->control
.in_infcall
)
3034 set_running (resume_target
, resume_ptid
, 1);
3037 fprintf_unfiltered (gdb_stdlog
,
3038 "infrun: proceed (addr=%s, signal=%s)\n",
3039 paddress (gdbarch
, addr
),
3040 gdb_signal_to_symbol_string (siggnal
));
3042 annotate_starting ();
3044 /* Make sure that output from GDB appears before output from the
3046 gdb_flush (gdb_stdout
);
3048 /* Since we've marked the inferior running, give it the terminal. A
3049 QUIT/Ctrl-C from here on is forwarded to the target (which can
3050 still detect attempts to unblock a stuck connection with repeated
3051 Ctrl-C from within target_pass_ctrlc). */
3052 target_terminal::inferior ();
3054 /* In a multi-threaded task we may select another thread and
3055 then continue or step.
3057 But if a thread that we're resuming had stopped at a breakpoint,
3058 it will immediately cause another breakpoint stop without any
3059 execution (i.e. it will report a breakpoint hit incorrectly). So
3060 we must step over it first.
3062 Look for threads other than the current (TP) that reported a
3063 breakpoint hit and haven't been resumed yet since. */
3065 /* If scheduler locking applies, we can avoid iterating over all
3067 if (!non_stop
&& !schedlock_applies (cur_thr
))
3069 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3072 switch_to_thread_no_regs (tp
);
3074 /* Ignore the current thread here. It's handled
3079 if (!thread_still_needs_step_over (tp
))
3082 gdb_assert (!thread_is_in_step_over_chain (tp
));
3085 fprintf_unfiltered (gdb_stdlog
,
3086 "infrun: need to step-over [%s] first\n",
3087 target_pid_to_str (tp
->ptid
).c_str ());
3089 thread_step_over_chain_enqueue (tp
);
3092 switch_to_thread (cur_thr
);
3095 /* Enqueue the current thread last, so that we move all other
3096 threads over their breakpoints first. */
3097 if (cur_thr
->stepping_over_breakpoint
)
3098 thread_step_over_chain_enqueue (cur_thr
);
3100 /* If the thread isn't started, we'll still need to set its prev_pc,
3101 so that switch_back_to_stepped_thread knows the thread hasn't
3102 advanced. Must do this before resuming any thread, as in
3103 all-stop/remote, once we resume we can't send any other packet
3104 until the target stops again. */
3105 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
3108 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3110 started
= start_step_over ();
3112 if (step_over_info_valid_p ())
3114 /* Either this thread started a new in-line step over, or some
3115 other thread was already doing one. In either case, don't
3116 resume anything else until the step-over is finished. */
3118 else if (started
&& !target_is_non_stop_p ())
3120 /* A new displaced stepping sequence was started. In all-stop,
3121 we can't talk to the target anymore until it next stops. */
3123 else if (!non_stop
&& target_is_non_stop_p ())
3125 /* In all-stop, but the target is always in non-stop mode.
3126 Start all other threads that are implicitly resumed too. */
3127 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3130 switch_to_thread_no_regs (tp
);
3132 if (!tp
->inf
->has_execution ())
3135 fprintf_unfiltered (gdb_stdlog
,
3136 "infrun: proceed: [%s] target has "
3138 target_pid_to_str (tp
->ptid
).c_str ());
3145 fprintf_unfiltered (gdb_stdlog
,
3146 "infrun: proceed: [%s] resumed\n",
3147 target_pid_to_str (tp
->ptid
).c_str ());
3148 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3152 if (thread_is_in_step_over_chain (tp
))
3155 fprintf_unfiltered (gdb_stdlog
,
3156 "infrun: proceed: [%s] needs step-over\n",
3157 target_pid_to_str (tp
->ptid
).c_str ());
3162 fprintf_unfiltered (gdb_stdlog
,
3163 "infrun: proceed: resuming %s\n",
3164 target_pid_to_str (tp
->ptid
).c_str ());
3166 reset_ecs (ecs
, tp
);
3167 switch_to_thread (tp
);
3168 keep_going_pass_signal (ecs
);
3169 if (!ecs
->wait_some_more
)
3170 error (_("Command aborted."));
3173 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3175 /* The thread wasn't started, and isn't queued, run it now. */
3176 reset_ecs (ecs
, cur_thr
);
3177 switch_to_thread (cur_thr
);
3178 keep_going_pass_signal (ecs
);
3179 if (!ecs
->wait_some_more
)
3180 error (_("Command aborted."));
3184 commit_resume_all_targets ();
3186 finish_state
.release ();
3188 /* If we've switched threads above, switch back to the previously
3189 current thread. We don't want the user to see a different
3191 switch_to_thread (cur_thr
);
3193 /* Tell the event loop to wait for it to stop. If the target
3194 supports asynchronous execution, it'll do this from within
3196 if (!target_can_async_p ())
3197 mark_async_event_handler (infrun_async_inferior_event_token
);
3201 /* Start remote-debugging of a machine over a serial link. */
3204 start_remote (int from_tty
)
3206 inferior
*inf
= current_inferior ();
3207 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3209 /* Always go on waiting for the target, regardless of the mode. */
3210 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3211 indicate to wait_for_inferior that a target should timeout if
3212 nothing is returned (instead of just blocking). Because of this,
3213 targets expecting an immediate response need to, internally, set
3214 things up so that the target_wait() is forced to eventually
3216 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3217 differentiate to its caller what the state of the target is after
3218 the initial open has been performed. Here we're assuming that
3219 the target has stopped. It should be possible to eventually have
3220 target_open() return to the caller an indication that the target
3221 is currently running and GDB state should be set to the same as
3222 for an async run. */
3223 wait_for_inferior (inf
);
3225 /* Now that the inferior has stopped, do any bookkeeping like
3226 loading shared libraries. We want to do this before normal_stop,
3227 so that the displayed frame is up to date. */
3228 post_create_inferior (current_top_target (), from_tty
);
3233 /* Initialize static vars when a new inferior begins. */
3236 init_wait_for_inferior (void)
3238 /* These are meaningless until the first time through wait_for_inferior. */
3240 breakpoint_init_inferior (inf_starting
);
3242 clear_proceed_status (0);
3244 nullify_last_target_wait_ptid ();
3246 previous_inferior_ptid
= inferior_ptid
;
3251 static void handle_inferior_event (struct execution_control_state
*ecs
);
3253 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3254 struct execution_control_state
*ecs
);
3255 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3256 struct execution_control_state
*ecs
);
3257 static void handle_signal_stop (struct execution_control_state
*ecs
);
3258 static void check_exception_resume (struct execution_control_state
*,
3259 struct frame_info
*);
3261 static void end_stepping_range (struct execution_control_state
*ecs
);
3262 static void stop_waiting (struct execution_control_state
*ecs
);
3263 static void keep_going (struct execution_control_state
*ecs
);
3264 static void process_event_stop_test (struct execution_control_state
*ecs
);
3265 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3267 /* This function is attached as a "thread_stop_requested" observer.
3268 Cleanup local state that assumed the PTID was to be resumed, and
3269 report the stop to the frontend. */
3272 infrun_thread_stop_requested (ptid_t ptid
)
3274 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3276 /* PTID was requested to stop. If the thread was already stopped,
3277 but the user/frontend doesn't know about that yet (e.g., the
3278 thread had been temporarily paused for some step-over), set up
3279 for reporting the stop now. */
3280 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3282 if (tp
->state
!= THREAD_RUNNING
)
3287 /* Remove matching threads from the step-over queue, so
3288 start_step_over doesn't try to resume them
3290 if (thread_is_in_step_over_chain (tp
))
3291 thread_step_over_chain_remove (tp
);
3293 /* If the thread is stopped, but the user/frontend doesn't
3294 know about that yet, queue a pending event, as if the
3295 thread had just stopped now. Unless the thread already had
3297 if (!tp
->suspend
.waitstatus_pending_p
)
3299 tp
->suspend
.waitstatus_pending_p
= 1;
3300 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3301 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3304 /* Clear the inline-frame state, since we're re-processing the
3306 clear_inline_frame_state (tp
);
3308 /* If this thread was paused because some other thread was
3309 doing an inline-step over, let that finish first. Once
3310 that happens, we'll restart all threads and consume pending
3311 stop events then. */
3312 if (step_over_info_valid_p ())
3315 /* Otherwise we can process the (new) pending event now. Set
3316 it so this pending event is considered by
3323 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3325 if (target_last_proc_target
== tp
->inf
->process_target ()
3326 && target_last_wait_ptid
== tp
->ptid
)
3327 nullify_last_target_wait_ptid ();
3330 /* Delete the step resume, single-step and longjmp/exception resume
3331 breakpoints of TP. */
3334 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3336 delete_step_resume_breakpoint (tp
);
3337 delete_exception_resume_breakpoint (tp
);
3338 delete_single_step_breakpoints (tp
);
3341 /* If the target still has execution, call FUNC for each thread that
3342 just stopped. In all-stop, that's all the non-exited threads; in
3343 non-stop, that's the current thread, only. */
3345 typedef void (*for_each_just_stopped_thread_callback_func
)
3346 (struct thread_info
*tp
);
3349 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3351 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3354 if (target_is_non_stop_p ())
3356 /* If in non-stop mode, only the current thread stopped. */
3357 func (inferior_thread ());
3361 /* In all-stop mode, all threads have stopped. */
3362 for (thread_info
*tp
: all_non_exited_threads ())
3367 /* Delete the step resume and longjmp/exception resume breakpoints of
3368 the threads that just stopped. */
3371 delete_just_stopped_threads_infrun_breakpoints (void)
3373 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3376 /* Delete the single-step breakpoints of the threads that just
3380 delete_just_stopped_threads_single_step_breakpoints (void)
3382 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3388 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3389 const struct target_waitstatus
*ws
)
3391 std::string status_string
= target_waitstatus_to_string (ws
);
3394 /* The text is split over several lines because it was getting too long.
3395 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3396 output as a unit; we want only one timestamp printed if debug_timestamp
3399 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3402 waiton_ptid
.tid ());
3403 if (waiton_ptid
.pid () != -1)
3404 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3405 stb
.printf (", status) =\n");
3406 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3410 target_pid_to_str (result_ptid
).c_str ());
3411 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3413 /* This uses %s in part to handle %'s in the text, but also to avoid
3414 a gcc error: the format attribute requires a string literal. */
3415 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3418 /* Select a thread at random, out of those which are resumed and have
3421 static struct thread_info
*
3422 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3426 auto has_event
= [&] (thread_info
*tp
)
3428 return (tp
->ptid
.matches (waiton_ptid
)
3430 && tp
->suspend
.waitstatus_pending_p
);
3433 /* First see how many events we have. Count only resumed threads
3434 that have an event pending. */
3435 for (thread_info
*tp
: inf
->non_exited_threads ())
3439 if (num_events
== 0)
3442 /* Now randomly pick a thread out of those that have had events. */
3443 int random_selector
= (int) ((num_events
* (double) rand ())
3444 / (RAND_MAX
+ 1.0));
3446 if (debug_infrun
&& num_events
> 1)
3447 fprintf_unfiltered (gdb_stdlog
,
3448 "infrun: Found %d events, selecting #%d\n",
3449 num_events
, random_selector
);
3451 /* Select the Nth thread that has had an event. */
3452 for (thread_info
*tp
: inf
->non_exited_threads ())
3454 if (random_selector
-- == 0)
3457 gdb_assert_not_reached ("event thread not found");
3460 /* Wrapper for target_wait that first checks whether threads have
3461 pending statuses to report before actually asking the target for
3462 more events. INF is the inferior we're using to call target_wait
3466 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3467 target_waitstatus
*status
, int options
)
3470 struct thread_info
*tp
;
3472 /* First check if there is a resumed thread with a wait status
3474 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3476 tp
= random_pending_event_thread (inf
, ptid
);
3481 fprintf_unfiltered (gdb_stdlog
,
3482 "infrun: Waiting for specific thread %s.\n",
3483 target_pid_to_str (ptid
).c_str ());
3485 /* We have a specific thread to check. */
3486 tp
= find_thread_ptid (inf
, ptid
);
3487 gdb_assert (tp
!= NULL
);
3488 if (!tp
->suspend
.waitstatus_pending_p
)
3493 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3494 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3496 struct regcache
*regcache
= get_thread_regcache (tp
);
3497 struct gdbarch
*gdbarch
= regcache
->arch ();
3501 pc
= regcache_read_pc (regcache
);
3503 if (pc
!= tp
->suspend
.stop_pc
)
3506 fprintf_unfiltered (gdb_stdlog
,
3507 "infrun: PC of %s changed. was=%s, now=%s\n",
3508 target_pid_to_str (tp
->ptid
).c_str (),
3509 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3510 paddress (gdbarch
, pc
));
3513 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3516 fprintf_unfiltered (gdb_stdlog
,
3517 "infrun: previous breakpoint of %s, at %s gone\n",
3518 target_pid_to_str (tp
->ptid
).c_str (),
3519 paddress (gdbarch
, pc
));
3527 fprintf_unfiltered (gdb_stdlog
,
3528 "infrun: pending event of %s cancelled.\n",
3529 target_pid_to_str (tp
->ptid
).c_str ());
3531 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3532 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3541 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3543 fprintf_unfiltered (gdb_stdlog
,
3544 "infrun: Using pending wait status %s for %s.\n",
3546 target_pid_to_str (tp
->ptid
).c_str ());
3549 /* Now that we've selected our final event LWP, un-adjust its PC
3550 if it was a software breakpoint (and the target doesn't
3551 always adjust the PC itself). */
3552 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3553 && !target_supports_stopped_by_sw_breakpoint ())
3555 struct regcache
*regcache
;
3556 struct gdbarch
*gdbarch
;
3559 regcache
= get_thread_regcache (tp
);
3560 gdbarch
= regcache
->arch ();
3562 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3567 pc
= regcache_read_pc (regcache
);
3568 regcache_write_pc (regcache
, pc
+ decr_pc
);
3572 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3573 *status
= tp
->suspend
.waitstatus
;
3574 tp
->suspend
.waitstatus_pending_p
= 0;
3576 /* Wake up the event loop again, until all pending events are
3578 if (target_is_async_p ())
3579 mark_async_event_handler (infrun_async_inferior_event_token
);
3583 /* But if we don't find one, we'll have to wait. */
3585 if (deprecated_target_wait_hook
)
3586 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3588 event_ptid
= target_wait (ptid
, status
, options
);
3593 /* Returns true if INF has any resumed thread with a status
3597 threads_are_resumed_pending_p (inferior
*inf
)
3599 for (thread_info
*tp
: inf
->non_exited_threads ())
3601 && tp
->suspend
.waitstatus_pending_p
)
3607 /* Wrapper for target_wait that first checks whether threads have
3608 pending statuses to report before actually asking the target for
3609 more events. Polls for events from all inferiors/targets. */
3612 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3614 int num_inferiors
= 0;
3615 int random_selector
;
3617 /* For fairness, we pick the first inferior/target to poll at
3618 random, and then continue polling the rest of the inferior list
3619 starting from that one in a circular fashion until the whole list
3622 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3624 return (inf
->process_target () != NULL
3625 && (threads_are_executing (inf
->process_target ())
3626 || threads_are_resumed_pending_p (inf
))
3627 && ptid_t (inf
->pid
).matches (wait_ptid
));
3630 /* First see how many resumed inferiors we have. */
3631 for (inferior
*inf
: all_inferiors ())
3632 if (inferior_matches (inf
))
3635 if (num_inferiors
== 0)
3637 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3641 /* Now randomly pick an inferior out of those that were resumed. */
3642 random_selector
= (int)
3643 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3645 if (debug_infrun
&& num_inferiors
> 1)
3646 fprintf_unfiltered (gdb_stdlog
,
3647 "infrun: Found %d inferiors, starting at #%d\n",
3648 num_inferiors
, random_selector
);
3650 /* Select the Nth inferior that was resumed. */
3652 inferior
*selected
= nullptr;
3654 for (inferior
*inf
: all_inferiors ())
3655 if (inferior_matches (inf
))
3656 if (random_selector
-- == 0)
3662 /* Now poll for events out of each of the resumed inferior's
3663 targets, starting from the selected one. */
3665 auto do_wait
= [&] (inferior
*inf
)
3667 switch_to_inferior_no_thread (inf
);
3669 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3670 ecs
->target
= inf
->process_target ();
3671 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3674 /* Needed in all-stop+target-non-stop mode, because we end up here
3675 spuriously after the target is all stopped and we've already
3676 reported the stop to the user, polling for events. */
3677 scoped_restore_current_thread restore_thread
;
3679 int inf_num
= selected
->num
;
3680 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3681 if (inferior_matches (inf
))
3685 for (inferior
*inf
= inferior_list
;
3686 inf
!= NULL
&& inf
->num
< inf_num
;
3688 if (inferior_matches (inf
))
3692 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3696 /* Prepare and stabilize the inferior for detaching it. E.g.,
3697 detaching while a thread is displaced stepping is a recipe for
3698 crashing it, as nothing would readjust the PC out of the scratch
3702 prepare_for_detach (void)
3704 struct inferior
*inf
= current_inferior ();
3705 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3707 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3709 /* Is any thread of this process displaced stepping? If not,
3710 there's nothing else to do. */
3711 if (displaced
->step_thread
== nullptr)
3715 fprintf_unfiltered (gdb_stdlog
,
3716 "displaced-stepping in-process while detaching");
3718 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3720 while (displaced
->step_thread
!= nullptr)
3722 struct execution_control_state ecss
;
3723 struct execution_control_state
*ecs
;
3726 memset (ecs
, 0, sizeof (*ecs
));
3728 overlay_cache_invalid
= 1;
3729 /* Flush target cache before starting to handle each event.
3730 Target was running and cache could be stale. This is just a
3731 heuristic. Running threads may modify target memory, but we
3732 don't get any event. */
3733 target_dcache_invalidate ();
3735 do_target_wait (pid_ptid
, ecs
, 0);
3738 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3740 /* If an error happens while handling the event, propagate GDB's
3741 knowledge of the executing state to the frontend/user running
3743 scoped_finish_thread_state
finish_state (inf
->process_target (),
3746 /* Now figure out what to do with the result of the result. */
3747 handle_inferior_event (ecs
);
3749 /* No error, don't finish the state yet. */
3750 finish_state
.release ();
3752 /* Breakpoints and watchpoints are not installed on the target
3753 at this point, and signals are passed directly to the
3754 inferior, so this must mean the process is gone. */
3755 if (!ecs
->wait_some_more
)
3757 restore_detaching
.release ();
3758 error (_("Program exited while detaching"));
3762 restore_detaching
.release ();
3765 /* Wait for control to return from inferior to debugger.
3767 If inferior gets a signal, we may decide to start it up again
3768 instead of returning. That is why there is a loop in this function.
3769 When this function actually returns it means the inferior
3770 should be left stopped and GDB should read more commands. */
3773 wait_for_inferior (inferior
*inf
)
3777 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3779 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3781 /* If an error happens while handling the event, propagate GDB's
3782 knowledge of the executing state to the frontend/user running
3784 scoped_finish_thread_state finish_state
3785 (inf
->process_target (), minus_one_ptid
);
3789 struct execution_control_state ecss
;
3790 struct execution_control_state
*ecs
= &ecss
;
3792 memset (ecs
, 0, sizeof (*ecs
));
3794 overlay_cache_invalid
= 1;
3796 /* Flush target cache before starting to handle each event.
3797 Target was running and cache could be stale. This is just a
3798 heuristic. Running threads may modify target memory, but we
3799 don't get any event. */
3800 target_dcache_invalidate ();
3802 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3803 ecs
->target
= inf
->process_target ();
3806 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3808 /* Now figure out what to do with the result of the result. */
3809 handle_inferior_event (ecs
);
3811 if (!ecs
->wait_some_more
)
3815 /* No error, don't finish the state yet. */
3816 finish_state
.release ();
3819 /* Cleanup that reinstalls the readline callback handler, if the
3820 target is running in the background. If while handling the target
3821 event something triggered a secondary prompt, like e.g., a
3822 pagination prompt, we'll have removed the callback handler (see
3823 gdb_readline_wrapper_line). Need to do this as we go back to the
3824 event loop, ready to process further input. Note this has no
3825 effect if the handler hasn't actually been removed, because calling
3826 rl_callback_handler_install resets the line buffer, thus losing
3830 reinstall_readline_callback_handler_cleanup ()
3832 struct ui
*ui
= current_ui
;
3836 /* We're not going back to the top level event loop yet. Don't
3837 install the readline callback, as it'd prep the terminal,
3838 readline-style (raw, noecho) (e.g., --batch). We'll install
3839 it the next time the prompt is displayed, when we're ready
3844 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3845 gdb_rl_callback_handler_reinstall ();
3848 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3849 that's just the event thread. In all-stop, that's all threads. */
3852 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3854 if (ecs
->event_thread
!= NULL
3855 && ecs
->event_thread
->thread_fsm
!= NULL
)
3856 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3860 for (thread_info
*thr
: all_non_exited_threads ())
3862 if (thr
->thread_fsm
== NULL
)
3864 if (thr
== ecs
->event_thread
)
3867 switch_to_thread (thr
);
3868 thr
->thread_fsm
->clean_up (thr
);
3871 if (ecs
->event_thread
!= NULL
)
3872 switch_to_thread (ecs
->event_thread
);
3876 /* Helper for all_uis_check_sync_execution_done that works on the
3880 check_curr_ui_sync_execution_done (void)
3882 struct ui
*ui
= current_ui
;
3884 if (ui
->prompt_state
== PROMPT_NEEDED
3886 && !gdb_in_secondary_prompt_p (ui
))
3888 target_terminal::ours ();
3889 gdb::observers::sync_execution_done
.notify ();
3890 ui_register_input_event_handler (ui
);
3897 all_uis_check_sync_execution_done (void)
3899 SWITCH_THRU_ALL_UIS ()
3901 check_curr_ui_sync_execution_done ();
3908 all_uis_on_sync_execution_starting (void)
3910 SWITCH_THRU_ALL_UIS ()
3912 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3913 async_disable_stdin ();
3917 /* Asynchronous version of wait_for_inferior. It is called by the
3918 event loop whenever a change of state is detected on the file
3919 descriptor corresponding to the target. It can be called more than
3920 once to complete a single execution command. In such cases we need
3921 to keep the state in a global variable ECSS. If it is the last time
3922 that this function is called for a single execution command, then
3923 report to the user that the inferior has stopped, and do the
3924 necessary cleanups. */
3927 fetch_inferior_event (void *client_data
)
3929 struct execution_control_state ecss
;
3930 struct execution_control_state
*ecs
= &ecss
;
3933 memset (ecs
, 0, sizeof (*ecs
));
3935 /* Events are always processed with the main UI as current UI. This
3936 way, warnings, debug output, etc. are always consistently sent to
3937 the main console. */
3938 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3940 /* End up with readline processing input, if necessary. */
3942 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3944 /* We're handling a live event, so make sure we're doing live
3945 debugging. If we're looking at traceframes while the target is
3946 running, we're going to need to get back to that mode after
3947 handling the event. */
3948 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3951 maybe_restore_traceframe
.emplace ();
3952 set_current_traceframe (-1);
3955 /* The user/frontend should not notice a thread switch due to
3956 internal events. Make sure we revert to the user selected
3957 thread and frame after handling the event and running any
3958 breakpoint commands. */
3959 scoped_restore_current_thread restore_thread
;
3961 overlay_cache_invalid
= 1;
3962 /* Flush target cache before starting to handle each event. Target
3963 was running and cache could be stale. This is just a heuristic.
3964 Running threads may modify target memory, but we don't get any
3966 target_dcache_invalidate ();
3968 scoped_restore save_exec_dir
3969 = make_scoped_restore (&execution_direction
,
3970 target_execution_direction ());
3972 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3975 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3977 /* Switch to the target that generated the event, so we can do
3978 target calls. Any inferior bound to the target will do, so we
3979 just switch to the first we find. */
3980 for (inferior
*inf
: all_inferiors (ecs
->target
))
3982 switch_to_inferior_no_thread (inf
);
3987 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3989 /* If an error happens while handling the event, propagate GDB's
3990 knowledge of the executing state to the frontend/user running
3992 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3993 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3995 /* Get executed before scoped_restore_current_thread above to apply
3996 still for the thread which has thrown the exception. */
3997 auto defer_bpstat_clear
3998 = make_scope_exit (bpstat_clear_actions
);
3999 auto defer_delete_threads
4000 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4002 /* Now figure out what to do with the result of the result. */
4003 handle_inferior_event (ecs
);
4005 if (!ecs
->wait_some_more
)
4007 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4008 int should_stop
= 1;
4009 struct thread_info
*thr
= ecs
->event_thread
;
4011 delete_just_stopped_threads_infrun_breakpoints ();
4015 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4017 if (thread_fsm
!= NULL
)
4018 should_stop
= thread_fsm
->should_stop (thr
);
4027 bool should_notify_stop
= true;
4030 clean_up_just_stopped_threads_fsms (ecs
);
4032 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4033 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4035 if (should_notify_stop
)
4037 /* We may not find an inferior if this was a process exit. */
4038 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4039 proceeded
= normal_stop ();
4044 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4048 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4049 previously selected thread is gone. We have two
4050 choices - switch to no thread selected, or restore the
4051 previously selected thread (now exited). We chose the
4052 later, just because that's what GDB used to do. After
4053 this, "info threads" says "The current thread <Thread
4054 ID 2> has terminated." instead of "No thread
4058 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4059 restore_thread
.dont_restore ();
4063 defer_delete_threads
.release ();
4064 defer_bpstat_clear
.release ();
4066 /* No error, don't finish the thread states yet. */
4067 finish_state
.release ();
4069 /* This scope is used to ensure that readline callbacks are
4070 reinstalled here. */
4073 /* If a UI was in sync execution mode, and now isn't, restore its
4074 prompt (a synchronous execution command has finished, and we're
4075 ready for input). */
4076 all_uis_check_sync_execution_done ();
4079 && exec_done_display_p
4080 && (inferior_ptid
== null_ptid
4081 || inferior_thread ()->state
!= THREAD_RUNNING
))
4082 printf_unfiltered (_("completed.\n"));
4085 /* Record the frame and location we're currently stepping through. */
4087 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
4089 struct thread_info
*tp
= inferior_thread ();
4091 tp
->control
.step_frame_id
= get_frame_id (frame
);
4092 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4094 tp
->current_symtab
= sal
.symtab
;
4095 tp
->current_line
= sal
.line
;
4098 /* Clear context switchable stepping state. */
4101 init_thread_stepping_state (struct thread_info
*tss
)
4103 tss
->stepped_breakpoint
= 0;
4104 tss
->stepping_over_breakpoint
= 0;
4105 tss
->stepping_over_watchpoint
= 0;
4106 tss
->step_after_step_resume_breakpoint
= 0;
4112 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4113 target_waitstatus status
)
4115 target_last_proc_target
= target
;
4116 target_last_wait_ptid
= ptid
;
4117 target_last_waitstatus
= status
;
4123 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4124 target_waitstatus
*status
)
4126 if (target
!= nullptr)
4127 *target
= target_last_proc_target
;
4128 if (ptid
!= nullptr)
4129 *ptid
= target_last_wait_ptid
;
4130 if (status
!= nullptr)
4131 *status
= target_last_waitstatus
;
4137 nullify_last_target_wait_ptid (void)
4139 target_last_proc_target
= nullptr;
4140 target_last_wait_ptid
= minus_one_ptid
;
4141 target_last_waitstatus
= {};
4144 /* Switch thread contexts. */
4147 context_switch (execution_control_state
*ecs
)
4150 && ecs
->ptid
!= inferior_ptid
4151 && (inferior_ptid
== null_ptid
4152 || ecs
->event_thread
!= inferior_thread ()))
4154 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4155 target_pid_to_str (inferior_ptid
).c_str ());
4156 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4157 target_pid_to_str (ecs
->ptid
).c_str ());
4160 switch_to_thread (ecs
->event_thread
);
4163 /* If the target can't tell whether we've hit breakpoints
4164 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4165 check whether that could have been caused by a breakpoint. If so,
4166 adjust the PC, per gdbarch_decr_pc_after_break. */
4169 adjust_pc_after_break (struct thread_info
*thread
,
4170 struct target_waitstatus
*ws
)
4172 struct regcache
*regcache
;
4173 struct gdbarch
*gdbarch
;
4174 CORE_ADDR breakpoint_pc
, decr_pc
;
4176 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4177 we aren't, just return.
4179 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4180 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4181 implemented by software breakpoints should be handled through the normal
4184 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4185 different signals (SIGILL or SIGEMT for instance), but it is less
4186 clear where the PC is pointing afterwards. It may not match
4187 gdbarch_decr_pc_after_break. I don't know any specific target that
4188 generates these signals at breakpoints (the code has been in GDB since at
4189 least 1992) so I can not guess how to handle them here.
4191 In earlier versions of GDB, a target with
4192 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4193 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4194 target with both of these set in GDB history, and it seems unlikely to be
4195 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4197 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4200 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4203 /* In reverse execution, when a breakpoint is hit, the instruction
4204 under it has already been de-executed. The reported PC always
4205 points at the breakpoint address, so adjusting it further would
4206 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4209 B1 0x08000000 : INSN1
4210 B2 0x08000001 : INSN2
4212 PC -> 0x08000003 : INSN4
4214 Say you're stopped at 0x08000003 as above. Reverse continuing
4215 from that point should hit B2 as below. Reading the PC when the
4216 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4217 been de-executed already.
4219 B1 0x08000000 : INSN1
4220 B2 PC -> 0x08000001 : INSN2
4224 We can't apply the same logic as for forward execution, because
4225 we would wrongly adjust the PC to 0x08000000, since there's a
4226 breakpoint at PC - 1. We'd then report a hit on B1, although
4227 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4229 if (execution_direction
== EXEC_REVERSE
)
4232 /* If the target can tell whether the thread hit a SW breakpoint,
4233 trust it. Targets that can tell also adjust the PC
4235 if (target_supports_stopped_by_sw_breakpoint ())
4238 /* Note that relying on whether a breakpoint is planted in memory to
4239 determine this can fail. E.g,. the breakpoint could have been
4240 removed since. Or the thread could have been told to step an
4241 instruction the size of a breakpoint instruction, and only
4242 _after_ was a breakpoint inserted at its address. */
4244 /* If this target does not decrement the PC after breakpoints, then
4245 we have nothing to do. */
4246 regcache
= get_thread_regcache (thread
);
4247 gdbarch
= regcache
->arch ();
4249 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4253 const address_space
*aspace
= regcache
->aspace ();
4255 /* Find the location where (if we've hit a breakpoint) the
4256 breakpoint would be. */
4257 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4259 /* If the target can't tell whether a software breakpoint triggered,
4260 fallback to figuring it out based on breakpoints we think were
4261 inserted in the target, and on whether the thread was stepped or
4264 /* Check whether there actually is a software breakpoint inserted at
4267 If in non-stop mode, a race condition is possible where we've
4268 removed a breakpoint, but stop events for that breakpoint were
4269 already queued and arrive later. To suppress those spurious
4270 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4271 and retire them after a number of stop events are reported. Note
4272 this is an heuristic and can thus get confused. The real fix is
4273 to get the "stopped by SW BP and needs adjustment" info out of
4274 the target/kernel (and thus never reach here; see above). */
4275 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4276 || (target_is_non_stop_p ()
4277 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4279 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4281 if (record_full_is_used ())
4282 restore_operation_disable
.emplace
4283 (record_full_gdb_operation_disable_set ());
4285 /* When using hardware single-step, a SIGTRAP is reported for both
4286 a completed single-step and a software breakpoint. Need to
4287 differentiate between the two, as the latter needs adjusting
4288 but the former does not.
4290 The SIGTRAP can be due to a completed hardware single-step only if
4291 - we didn't insert software single-step breakpoints
4292 - this thread is currently being stepped
4294 If any of these events did not occur, we must have stopped due
4295 to hitting a software breakpoint, and have to back up to the
4298 As a special case, we could have hardware single-stepped a
4299 software breakpoint. In this case (prev_pc == breakpoint_pc),
4300 we also need to back up to the breakpoint address. */
4302 if (thread_has_single_step_breakpoints_set (thread
)
4303 || !currently_stepping (thread
)
4304 || (thread
->stepped_breakpoint
4305 && thread
->prev_pc
== breakpoint_pc
))
4306 regcache_write_pc (regcache
, breakpoint_pc
);
4311 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4313 for (frame
= get_prev_frame (frame
);
4315 frame
= get_prev_frame (frame
))
4317 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4319 if (get_frame_type (frame
) != INLINE_FRAME
)
4326 /* Look for an inline frame that is marked for skip.
4327 If PREV_FRAME is TRUE start at the previous frame,
4328 otherwise start at the current frame. Stop at the
4329 first non-inline frame, or at the frame where the
4333 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4335 struct frame_info
*frame
= get_current_frame ();
4338 frame
= get_prev_frame (frame
);
4340 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4342 const char *fn
= NULL
;
4343 symtab_and_line sal
;
4346 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4348 if (get_frame_type (frame
) != INLINE_FRAME
)
4351 sal
= find_frame_sal (frame
);
4352 sym
= get_frame_function (frame
);
4355 fn
= sym
->print_name ();
4358 && function_name_is_marked_for_skip (fn
, sal
))
4365 /* If the event thread has the stop requested flag set, pretend it
4366 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4370 handle_stop_requested (struct execution_control_state
*ecs
)
4372 if (ecs
->event_thread
->stop_requested
)
4374 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4375 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4376 handle_signal_stop (ecs
);
4382 /* Auxiliary function that handles syscall entry/return events.
4383 It returns 1 if the inferior should keep going (and GDB
4384 should ignore the event), or 0 if the event deserves to be
4388 handle_syscall_event (struct execution_control_state
*ecs
)
4390 struct regcache
*regcache
;
4393 context_switch (ecs
);
4395 regcache
= get_thread_regcache (ecs
->event_thread
);
4396 syscall_number
= ecs
->ws
.value
.syscall_number
;
4397 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4399 if (catch_syscall_enabled () > 0
4400 && catching_syscall_number (syscall_number
) > 0)
4403 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4406 ecs
->event_thread
->control
.stop_bpstat
4407 = bpstat_stop_status (regcache
->aspace (),
4408 ecs
->event_thread
->suspend
.stop_pc
,
4409 ecs
->event_thread
, &ecs
->ws
);
4411 if (handle_stop_requested (ecs
))
4414 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4416 /* Catchpoint hit. */
4421 if (handle_stop_requested (ecs
))
4424 /* If no catchpoint triggered for this, then keep going. */
4429 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4432 fill_in_stop_func (struct gdbarch
*gdbarch
,
4433 struct execution_control_state
*ecs
)
4435 if (!ecs
->stop_func_filled_in
)
4439 /* Don't care about return value; stop_func_start and stop_func_name
4440 will both be 0 if it doesn't work. */
4441 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4442 &ecs
->stop_func_name
,
4443 &ecs
->stop_func_start
,
4444 &ecs
->stop_func_end
,
4447 /* The call to find_pc_partial_function, above, will set
4448 stop_func_start and stop_func_end to the start and end
4449 of the range containing the stop pc. If this range
4450 contains the entry pc for the block (which is always the
4451 case for contiguous blocks), advance stop_func_start past
4452 the function's start offset and entrypoint. Note that
4453 stop_func_start is NOT advanced when in a range of a
4454 non-contiguous block that does not contain the entry pc. */
4455 if (block
!= nullptr
4456 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4457 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4459 ecs
->stop_func_start
4460 += gdbarch_deprecated_function_start_offset (gdbarch
);
4462 if (gdbarch_skip_entrypoint_p (gdbarch
))
4463 ecs
->stop_func_start
4464 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4467 ecs
->stop_func_filled_in
= 1;
4472 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4474 static enum stop_kind
4475 get_inferior_stop_soon (execution_control_state
*ecs
)
4477 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4479 gdb_assert (inf
!= NULL
);
4480 return inf
->control
.stop_soon
;
4483 /* Poll for one event out of the current target. Store the resulting
4484 waitstatus in WS, and return the event ptid. Does not block. */
4487 poll_one_curr_target (struct target_waitstatus
*ws
)
4491 overlay_cache_invalid
= 1;
4493 /* Flush target cache before starting to handle each event.
4494 Target was running and cache could be stale. This is just a
4495 heuristic. Running threads may modify target memory, but we
4496 don't get any event. */
4497 target_dcache_invalidate ();
4499 if (deprecated_target_wait_hook
)
4500 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4502 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4505 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4510 /* An event reported by wait_one. */
4512 struct wait_one_event
4514 /* The target the event came out of. */
4515 process_stratum_target
*target
;
4517 /* The PTID the event was for. */
4520 /* The waitstatus. */
4521 target_waitstatus ws
;
4524 /* Wait for one event out of any target. */
4526 static wait_one_event
4531 for (inferior
*inf
: all_inferiors ())
4533 process_stratum_target
*target
= inf
->process_target ();
4535 || !target
->is_async_p ()
4536 || !target
->threads_executing
)
4539 switch_to_inferior_no_thread (inf
);
4541 wait_one_event event
;
4542 event
.target
= target
;
4543 event
.ptid
= poll_one_curr_target (&event
.ws
);
4545 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4547 /* If nothing is resumed, remove the target from the
4551 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4555 /* Block waiting for some event. */
4562 for (inferior
*inf
: all_inferiors ())
4564 process_stratum_target
*target
= inf
->process_target ();
4566 || !target
->is_async_p ()
4567 || !target
->threads_executing
)
4570 int fd
= target
->async_wait_fd ();
4571 FD_SET (fd
, &readfds
);
4578 /* No waitable targets left. All must be stopped. */
4579 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4584 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4590 perror_with_name ("interruptible_select");
4595 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4596 instead of the current thread. */
4597 #define THREAD_STOPPED_BY(REASON) \
4599 thread_stopped_by_ ## REASON (ptid_t ptid) \
4601 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4602 inferior_ptid = ptid; \
4604 return target_stopped_by_ ## REASON (); \
4607 /* Generate thread_stopped_by_watchpoint. */
4608 THREAD_STOPPED_BY (watchpoint
)
4609 /* Generate thread_stopped_by_sw_breakpoint. */
4610 THREAD_STOPPED_BY (sw_breakpoint
)
4611 /* Generate thread_stopped_by_hw_breakpoint. */
4612 THREAD_STOPPED_BY (hw_breakpoint
)
4614 /* Save the thread's event and stop reason to process it later. */
4617 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4621 std::string statstr
= target_waitstatus_to_string (ws
);
4623 fprintf_unfiltered (gdb_stdlog
,
4624 "infrun: saving status %s for %d.%ld.%ld\n",
4631 /* Record for later. */
4632 tp
->suspend
.waitstatus
= *ws
;
4633 tp
->suspend
.waitstatus_pending_p
= 1;
4635 struct regcache
*regcache
= get_thread_regcache (tp
);
4636 const address_space
*aspace
= regcache
->aspace ();
4638 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4639 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4641 CORE_ADDR pc
= regcache_read_pc (regcache
);
4643 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4645 if (thread_stopped_by_watchpoint (tp
->ptid
))
4647 tp
->suspend
.stop_reason
4648 = TARGET_STOPPED_BY_WATCHPOINT
;
4650 else if (target_supports_stopped_by_sw_breakpoint ()
4651 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4653 tp
->suspend
.stop_reason
4654 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4656 else if (target_supports_stopped_by_hw_breakpoint ()
4657 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4659 tp
->suspend
.stop_reason
4660 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4662 else if (!target_supports_stopped_by_hw_breakpoint ()
4663 && hardware_breakpoint_inserted_here_p (aspace
,
4666 tp
->suspend
.stop_reason
4667 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4669 else if (!target_supports_stopped_by_sw_breakpoint ()
4670 && software_breakpoint_inserted_here_p (aspace
,
4673 tp
->suspend
.stop_reason
4674 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4676 else if (!thread_has_single_step_breakpoints_set (tp
)
4677 && currently_stepping (tp
))
4679 tp
->suspend
.stop_reason
4680 = TARGET_STOPPED_BY_SINGLE_STEP
;
4688 stop_all_threads (void)
4690 /* We may need multiple passes to discover all threads. */
4694 gdb_assert (target_is_non_stop_p ());
4697 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4699 scoped_restore_current_thread restore_thread
;
4701 target_thread_events (1);
4702 SCOPE_EXIT
{ target_thread_events (0); };
4704 /* Request threads to stop, and then wait for the stops. Because
4705 threads we already know about can spawn more threads while we're
4706 trying to stop them, and we only learn about new threads when we
4707 update the thread list, do this in a loop, and keep iterating
4708 until two passes find no threads that need to be stopped. */
4709 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4712 fprintf_unfiltered (gdb_stdlog
,
4713 "infrun: stop_all_threads, pass=%d, "
4714 "iterations=%d\n", pass
, iterations
);
4719 update_thread_list ();
4721 /* Go through all threads looking for threads that we need
4722 to tell the target to stop. */
4723 for (thread_info
*t
: all_non_exited_threads ())
4727 /* If already stopping, don't request a stop again.
4728 We just haven't seen the notification yet. */
4729 if (!t
->stop_requested
)
4732 fprintf_unfiltered (gdb_stdlog
,
4733 "infrun: %s executing, "
4735 target_pid_to_str (t
->ptid
).c_str ());
4736 switch_to_thread_no_regs (t
);
4737 target_stop (t
->ptid
);
4738 t
->stop_requested
= 1;
4743 fprintf_unfiltered (gdb_stdlog
,
4744 "infrun: %s executing, "
4745 "already stopping\n",
4746 target_pid_to_str (t
->ptid
).c_str ());
4749 if (t
->stop_requested
)
4755 fprintf_unfiltered (gdb_stdlog
,
4756 "infrun: %s not executing\n",
4757 target_pid_to_str (t
->ptid
).c_str ());
4759 /* The thread may be not executing, but still be
4760 resumed with a pending status to process. */
4768 /* If we find new threads on the second iteration, restart
4769 over. We want to see two iterations in a row with all
4774 wait_one_event event
= wait_one ();
4778 fprintf_unfiltered (gdb_stdlog
,
4779 "infrun: stop_all_threads %s %s\n",
4780 target_waitstatus_to_string (&event
.ws
).c_str (),
4781 target_pid_to_str (event
.ptid
).c_str ());
4784 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4785 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4786 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4787 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4789 /* All resumed threads exited
4790 or one thread/process exited/signalled. */
4794 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4796 t
= add_thread (event
.target
, event
.ptid
);
4798 t
->stop_requested
= 0;
4801 t
->control
.may_range_step
= 0;
4803 /* This may be the first time we see the inferior report
4805 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4806 if (inf
->needs_setup
)
4808 switch_to_thread_no_regs (t
);
4812 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4813 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4815 /* We caught the event that we intended to catch, so
4816 there's no event pending. */
4817 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4818 t
->suspend
.waitstatus_pending_p
= 0;
4820 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4822 /* Add it back to the step-over queue. */
4825 fprintf_unfiltered (gdb_stdlog
,
4826 "infrun: displaced-step of %s "
4827 "canceled: adding back to the "
4828 "step-over queue\n",
4829 target_pid_to_str (t
->ptid
).c_str ());
4831 t
->control
.trap_expected
= 0;
4832 thread_step_over_chain_enqueue (t
);
4837 enum gdb_signal sig
;
4838 struct regcache
*regcache
;
4842 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4844 fprintf_unfiltered (gdb_stdlog
,
4845 "infrun: target_wait %s, saving "
4846 "status for %d.%ld.%ld\n",
4853 /* Record for later. */
4854 save_waitstatus (t
, &event
.ws
);
4856 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4857 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4859 if (displaced_step_fixup (t
, sig
) < 0)
4861 /* Add it back to the step-over queue. */
4862 t
->control
.trap_expected
= 0;
4863 thread_step_over_chain_enqueue (t
);
4866 regcache
= get_thread_regcache (t
);
4867 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4871 fprintf_unfiltered (gdb_stdlog
,
4872 "infrun: saved stop_pc=%s for %s "
4873 "(currently_stepping=%d)\n",
4874 paddress (target_gdbarch (),
4875 t
->suspend
.stop_pc
),
4876 target_pid_to_str (t
->ptid
).c_str (),
4877 currently_stepping (t
));
4885 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4888 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4891 handle_no_resumed (struct execution_control_state
*ecs
)
4893 if (target_can_async_p ())
4900 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4908 /* There were no unwaited-for children left in the target, but,
4909 we're not synchronously waiting for events either. Just
4913 fprintf_unfiltered (gdb_stdlog
,
4914 "infrun: TARGET_WAITKIND_NO_RESUMED "
4915 "(ignoring: bg)\n");
4916 prepare_to_wait (ecs
);
4921 /* Otherwise, if we were running a synchronous execution command, we
4922 may need to cancel it and give the user back the terminal.
4924 In non-stop mode, the target can't tell whether we've already
4925 consumed previous stop events, so it can end up sending us a
4926 no-resumed event like so:
4928 #0 - thread 1 is left stopped
4930 #1 - thread 2 is resumed and hits breakpoint
4931 -> TARGET_WAITKIND_STOPPED
4933 #2 - thread 3 is resumed and exits
4934 this is the last resumed thread, so
4935 -> TARGET_WAITKIND_NO_RESUMED
4937 #3 - gdb processes stop for thread 2 and decides to re-resume
4940 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4941 thread 2 is now resumed, so the event should be ignored.
4943 IOW, if the stop for thread 2 doesn't end a foreground command,
4944 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4945 event. But it could be that the event meant that thread 2 itself
4946 (or whatever other thread was the last resumed thread) exited.
4948 To address this we refresh the thread list and check whether we
4949 have resumed threads _now_. In the example above, this removes
4950 thread 3 from the thread list. If thread 2 was re-resumed, we
4951 ignore this event. If we find no thread resumed, then we cancel
4952 the synchronous command show "no unwaited-for " to the user. */
4953 update_thread_list ();
4955 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4957 if (thread
->executing
4958 || thread
->suspend
.waitstatus_pending_p
)
4960 /* There were no unwaited-for children left in the target at
4961 some point, but there are now. Just ignore. */
4963 fprintf_unfiltered (gdb_stdlog
,
4964 "infrun: TARGET_WAITKIND_NO_RESUMED "
4965 "(ignoring: found resumed)\n");
4966 prepare_to_wait (ecs
);
4971 /* Note however that we may find no resumed thread because the whole
4972 process exited meanwhile (thus updating the thread list results
4973 in an empty thread list). In this case we know we'll be getting
4974 a process exit event shortly. */
4975 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
4977 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4981 fprintf_unfiltered (gdb_stdlog
,
4982 "infrun: TARGET_WAITKIND_NO_RESUMED "
4983 "(expect process exit)\n");
4984 prepare_to_wait (ecs
);
4989 /* Go ahead and report the event. */
4993 /* Given an execution control state that has been freshly filled in by
4994 an event from the inferior, figure out what it means and take
4997 The alternatives are:
4999 1) stop_waiting and return; to really stop and return to the
5002 2) keep_going and return; to wait for the next event (set
5003 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5007 handle_inferior_event (struct execution_control_state
*ecs
)
5009 /* Make sure that all temporary struct value objects that were
5010 created during the handling of the event get deleted at the
5012 scoped_value_mark free_values
;
5014 enum stop_kind stop_soon
;
5017 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5018 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5020 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5022 /* We had an event in the inferior, but we are not interested in
5023 handling it at this level. The lower layers have already
5024 done what needs to be done, if anything.
5026 One of the possible circumstances for this is when the
5027 inferior produces output for the console. The inferior has
5028 not stopped, and we are ignoring the event. Another possible
5029 circumstance is any event which the lower level knows will be
5030 reported multiple times without an intervening resume. */
5031 prepare_to_wait (ecs
);
5035 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5037 prepare_to_wait (ecs
);
5041 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5042 && handle_no_resumed (ecs
))
5045 /* Cache the last target/ptid/waitstatus. */
5046 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5048 /* Always clear state belonging to the previous time we stopped. */
5049 stop_stack_dummy
= STOP_NONE
;
5051 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5053 /* No unwaited-for children left. IOW, all resumed children
5055 stop_print_frame
= 0;
5060 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5061 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5063 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5064 /* If it's a new thread, add it to the thread database. */
5065 if (ecs
->event_thread
== NULL
)
5066 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5068 /* Disable range stepping. If the next step request could use a
5069 range, this will be end up re-enabled then. */
5070 ecs
->event_thread
->control
.may_range_step
= 0;
5073 /* Dependent on valid ECS->EVENT_THREAD. */
5074 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5076 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5077 reinit_frame_cache ();
5079 breakpoint_retire_moribund ();
5081 /* First, distinguish signals caused by the debugger from signals
5082 that have to do with the program's own actions. Note that
5083 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5084 on the operating system version. Here we detect when a SIGILL or
5085 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5086 something similar for SIGSEGV, since a SIGSEGV will be generated
5087 when we're trying to execute a breakpoint instruction on a
5088 non-executable stack. This happens for call dummy breakpoints
5089 for architectures like SPARC that place call dummies on the
5091 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5092 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5093 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5094 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5096 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5098 if (breakpoint_inserted_here_p (regcache
->aspace (),
5099 regcache_read_pc (regcache
)))
5102 fprintf_unfiltered (gdb_stdlog
,
5103 "infrun: Treating signal as SIGTRAP\n");
5104 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5108 /* Mark the non-executing threads accordingly. In all-stop, all
5109 threads of all processes are stopped when we get any event
5110 reported. In non-stop mode, only the event thread stops. */
5114 if (!target_is_non_stop_p ())
5115 mark_ptid
= minus_one_ptid
;
5116 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
5117 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5119 /* If we're handling a process exit in non-stop mode, even
5120 though threads haven't been deleted yet, one would think
5121 that there is nothing to do, as threads of the dead process
5122 will be soon deleted, and threads of any other process were
5123 left running. However, on some targets, threads survive a
5124 process exit event. E.g., for the "checkpoint" command,
5125 when the current checkpoint/fork exits, linux-fork.c
5126 automatically switches to another fork from within
5127 target_mourn_inferior, by associating the same
5128 inferior/thread to another fork. We haven't mourned yet at
5129 this point, but we must mark any threads left in the
5130 process as not-executing so that finish_thread_state marks
5131 them stopped (in the user's perspective) if/when we present
5132 the stop to the user. */
5133 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
5136 mark_ptid
= ecs
->ptid
;
5138 set_executing (ecs
->target
, mark_ptid
, 0);
5140 /* Likewise the resumed flag. */
5141 set_resumed (ecs
->target
, mark_ptid
, 0);
5144 switch (ecs
->ws
.kind
)
5146 case TARGET_WAITKIND_LOADED
:
5147 context_switch (ecs
);
5148 /* Ignore gracefully during startup of the inferior, as it might
5149 be the shell which has just loaded some objects, otherwise
5150 add the symbols for the newly loaded objects. Also ignore at
5151 the beginning of an attach or remote session; we will query
5152 the full list of libraries once the connection is
5155 stop_soon
= get_inferior_stop_soon (ecs
);
5156 if (stop_soon
== NO_STOP_QUIETLY
)
5158 struct regcache
*regcache
;
5160 regcache
= get_thread_regcache (ecs
->event_thread
);
5162 handle_solib_event ();
5164 ecs
->event_thread
->control
.stop_bpstat
5165 = bpstat_stop_status (regcache
->aspace (),
5166 ecs
->event_thread
->suspend
.stop_pc
,
5167 ecs
->event_thread
, &ecs
->ws
);
5169 if (handle_stop_requested (ecs
))
5172 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5174 /* A catchpoint triggered. */
5175 process_event_stop_test (ecs
);
5179 /* If requested, stop when the dynamic linker notifies
5180 gdb of events. This allows the user to get control
5181 and place breakpoints in initializer routines for
5182 dynamically loaded objects (among other things). */
5183 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5184 if (stop_on_solib_events
)
5186 /* Make sure we print "Stopped due to solib-event" in
5188 stop_print_frame
= 1;
5195 /* If we are skipping through a shell, or through shared library
5196 loading that we aren't interested in, resume the program. If
5197 we're running the program normally, also resume. */
5198 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5200 /* Loading of shared libraries might have changed breakpoint
5201 addresses. Make sure new breakpoints are inserted. */
5202 if (stop_soon
== NO_STOP_QUIETLY
)
5203 insert_breakpoints ();
5204 resume (GDB_SIGNAL_0
);
5205 prepare_to_wait (ecs
);
5209 /* But stop if we're attaching or setting up a remote
5211 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5212 || stop_soon
== STOP_QUIETLY_REMOTE
)
5215 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5220 internal_error (__FILE__
, __LINE__
,
5221 _("unhandled stop_soon: %d"), (int) stop_soon
);
5223 case TARGET_WAITKIND_SPURIOUS
:
5224 if (handle_stop_requested (ecs
))
5226 context_switch (ecs
);
5227 resume (GDB_SIGNAL_0
);
5228 prepare_to_wait (ecs
);
5231 case TARGET_WAITKIND_THREAD_CREATED
:
5232 if (handle_stop_requested (ecs
))
5234 context_switch (ecs
);
5235 if (!switch_back_to_stepped_thread (ecs
))
5239 case TARGET_WAITKIND_EXITED
:
5240 case TARGET_WAITKIND_SIGNALLED
:
5241 inferior_ptid
= ecs
->ptid
;
5242 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5243 set_current_program_space (current_inferior ()->pspace
);
5244 handle_vfork_child_exec_or_exit (0);
5245 target_terminal::ours (); /* Must do this before mourn anyway. */
5247 /* Clearing any previous state of convenience variables. */
5248 clear_exit_convenience_vars ();
5250 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5252 /* Record the exit code in the convenience variable $_exitcode, so
5253 that the user can inspect this again later. */
5254 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5255 (LONGEST
) ecs
->ws
.value
.integer
);
5257 /* Also record this in the inferior itself. */
5258 current_inferior ()->has_exit_code
= 1;
5259 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5261 /* Support the --return-child-result option. */
5262 return_child_result_value
= ecs
->ws
.value
.integer
;
5264 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5268 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5270 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5272 /* Set the value of the internal variable $_exitsignal,
5273 which holds the signal uncaught by the inferior. */
5274 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5275 gdbarch_gdb_signal_to_target (gdbarch
,
5276 ecs
->ws
.value
.sig
));
5280 /* We don't have access to the target's method used for
5281 converting between signal numbers (GDB's internal
5282 representation <-> target's representation).
5283 Therefore, we cannot do a good job at displaying this
5284 information to the user. It's better to just warn
5285 her about it (if infrun debugging is enabled), and
5288 fprintf_filtered (gdb_stdlog
, _("\
5289 Cannot fill $_exitsignal with the correct signal number.\n"));
5292 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5295 gdb_flush (gdb_stdout
);
5296 target_mourn_inferior (inferior_ptid
);
5297 stop_print_frame
= 0;
5301 /* The following are the only cases in which we keep going;
5302 the above cases end in a continue or goto. */
5303 case TARGET_WAITKIND_FORKED
:
5304 case TARGET_WAITKIND_VFORKED
:
5305 /* Check whether the inferior is displaced stepping. */
5307 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5308 struct gdbarch
*gdbarch
= regcache
->arch ();
5310 /* If checking displaced stepping is supported, and thread
5311 ecs->ptid is displaced stepping. */
5312 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5314 struct inferior
*parent_inf
5315 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5316 struct regcache
*child_regcache
;
5317 CORE_ADDR parent_pc
;
5319 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5320 indicating that the displaced stepping of syscall instruction
5321 has been done. Perform cleanup for parent process here. Note
5322 that this operation also cleans up the child process for vfork,
5323 because their pages are shared. */
5324 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5325 /* Start a new step-over in another thread if there's one
5329 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5331 struct displaced_step_inferior_state
*displaced
5332 = get_displaced_stepping_state (parent_inf
);
5334 /* Restore scratch pad for child process. */
5335 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5338 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5339 the child's PC is also within the scratchpad. Set the child's PC
5340 to the parent's PC value, which has already been fixed up.
5341 FIXME: we use the parent's aspace here, although we're touching
5342 the child, because the child hasn't been added to the inferior
5343 list yet at this point. */
5346 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5347 ecs
->ws
.value
.related_pid
,
5349 parent_inf
->aspace
);
5350 /* Read PC value of parent process. */
5351 parent_pc
= regcache_read_pc (regcache
);
5353 if (debug_displaced
)
5354 fprintf_unfiltered (gdb_stdlog
,
5355 "displaced: write child pc from %s to %s\n",
5357 regcache_read_pc (child_regcache
)),
5358 paddress (gdbarch
, parent_pc
));
5360 regcache_write_pc (child_regcache
, parent_pc
);
5364 context_switch (ecs
);
5366 /* Immediately detach breakpoints from the child before there's
5367 any chance of letting the user delete breakpoints from the
5368 breakpoint lists. If we don't do this early, it's easy to
5369 leave left over traps in the child, vis: "break foo; catch
5370 fork; c; <fork>; del; c; <child calls foo>". We only follow
5371 the fork on the last `continue', and by that time the
5372 breakpoint at "foo" is long gone from the breakpoint table.
5373 If we vforked, then we don't need to unpatch here, since both
5374 parent and child are sharing the same memory pages; we'll
5375 need to unpatch at follow/detach time instead to be certain
5376 that new breakpoints added between catchpoint hit time and
5377 vfork follow are detached. */
5378 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5380 /* This won't actually modify the breakpoint list, but will
5381 physically remove the breakpoints from the child. */
5382 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5385 delete_just_stopped_threads_single_step_breakpoints ();
5387 /* In case the event is caught by a catchpoint, remember that
5388 the event is to be followed at the next resume of the thread,
5389 and not immediately. */
5390 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5392 ecs
->event_thread
->suspend
.stop_pc
5393 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5395 ecs
->event_thread
->control
.stop_bpstat
5396 = bpstat_stop_status (get_current_regcache ()->aspace (),
5397 ecs
->event_thread
->suspend
.stop_pc
,
5398 ecs
->event_thread
, &ecs
->ws
);
5400 if (handle_stop_requested (ecs
))
5403 /* If no catchpoint triggered for this, then keep going. Note
5404 that we're interested in knowing the bpstat actually causes a
5405 stop, not just if it may explain the signal. Software
5406 watchpoints, for example, always appear in the bpstat. */
5407 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5411 = (follow_fork_mode_string
== follow_fork_mode_child
);
5413 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5415 process_stratum_target
*targ
5416 = ecs
->event_thread
->inf
->process_target ();
5418 should_resume
= follow_fork ();
5420 /* Note that one of these may be an invalid pointer,
5421 depending on detach_fork. */
5422 thread_info
*parent
= ecs
->event_thread
;
5424 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5426 /* At this point, the parent is marked running, and the
5427 child is marked stopped. */
5429 /* If not resuming the parent, mark it stopped. */
5430 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5431 parent
->set_running (false);
5433 /* If resuming the child, mark it running. */
5434 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5435 child
->set_running (true);
5437 /* In non-stop mode, also resume the other branch. */
5438 if (!detach_fork
&& (non_stop
5439 || (sched_multi
&& target_is_non_stop_p ())))
5442 switch_to_thread (parent
);
5444 switch_to_thread (child
);
5446 ecs
->event_thread
= inferior_thread ();
5447 ecs
->ptid
= inferior_ptid
;
5452 switch_to_thread (child
);
5454 switch_to_thread (parent
);
5456 ecs
->event_thread
= inferior_thread ();
5457 ecs
->ptid
= inferior_ptid
;
5465 process_event_stop_test (ecs
);
5468 case TARGET_WAITKIND_VFORK_DONE
:
5469 /* Done with the shared memory region. Re-insert breakpoints in
5470 the parent, and keep going. */
5472 context_switch (ecs
);
5474 current_inferior ()->waiting_for_vfork_done
= 0;
5475 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5477 if (handle_stop_requested (ecs
))
5480 /* This also takes care of reinserting breakpoints in the
5481 previously locked inferior. */
5485 case TARGET_WAITKIND_EXECD
:
5487 /* Note we can't read registers yet (the stop_pc), because we
5488 don't yet know the inferior's post-exec architecture.
5489 'stop_pc' is explicitly read below instead. */
5490 switch_to_thread_no_regs (ecs
->event_thread
);
5492 /* Do whatever is necessary to the parent branch of the vfork. */
5493 handle_vfork_child_exec_or_exit (1);
5495 /* This causes the eventpoints and symbol table to be reset.
5496 Must do this now, before trying to determine whether to
5498 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5500 /* In follow_exec we may have deleted the original thread and
5501 created a new one. Make sure that the event thread is the
5502 execd thread for that case (this is a nop otherwise). */
5503 ecs
->event_thread
= inferior_thread ();
5505 ecs
->event_thread
->suspend
.stop_pc
5506 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5508 ecs
->event_thread
->control
.stop_bpstat
5509 = bpstat_stop_status (get_current_regcache ()->aspace (),
5510 ecs
->event_thread
->suspend
.stop_pc
,
5511 ecs
->event_thread
, &ecs
->ws
);
5513 /* Note that this may be referenced from inside
5514 bpstat_stop_status above, through inferior_has_execd. */
5515 xfree (ecs
->ws
.value
.execd_pathname
);
5516 ecs
->ws
.value
.execd_pathname
= NULL
;
5518 if (handle_stop_requested (ecs
))
5521 /* If no catchpoint triggered for this, then keep going. */
5522 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5524 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5528 process_event_stop_test (ecs
);
5531 /* Be careful not to try to gather much state about a thread
5532 that's in a syscall. It's frequently a losing proposition. */
5533 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5534 /* Getting the current syscall number. */
5535 if (handle_syscall_event (ecs
) == 0)
5536 process_event_stop_test (ecs
);
5539 /* Before examining the threads further, step this thread to
5540 get it entirely out of the syscall. (We get notice of the
5541 event when the thread is just on the verge of exiting a
5542 syscall. Stepping one instruction seems to get it back
5544 case TARGET_WAITKIND_SYSCALL_RETURN
:
5545 if (handle_syscall_event (ecs
) == 0)
5546 process_event_stop_test (ecs
);
5549 case TARGET_WAITKIND_STOPPED
:
5550 handle_signal_stop (ecs
);
5553 case TARGET_WAITKIND_NO_HISTORY
:
5554 /* Reverse execution: target ran out of history info. */
5556 /* Switch to the stopped thread. */
5557 context_switch (ecs
);
5559 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5561 delete_just_stopped_threads_single_step_breakpoints ();
5562 ecs
->event_thread
->suspend
.stop_pc
5563 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5565 if (handle_stop_requested (ecs
))
5568 gdb::observers::no_history
.notify ();
5574 /* Restart threads back to what they were trying to do back when we
5575 paused them for an in-line step-over. The EVENT_THREAD thread is
5579 restart_threads (struct thread_info
*event_thread
)
5581 /* In case the instruction just stepped spawned a new thread. */
5582 update_thread_list ();
5584 for (thread_info
*tp
: all_non_exited_threads ())
5586 switch_to_thread_no_regs (tp
);
5588 if (tp
== event_thread
)
5591 fprintf_unfiltered (gdb_stdlog
,
5592 "infrun: restart threads: "
5593 "[%s] is event thread\n",
5594 target_pid_to_str (tp
->ptid
).c_str ());
5598 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5601 fprintf_unfiltered (gdb_stdlog
,
5602 "infrun: restart threads: "
5603 "[%s] not meant to be running\n",
5604 target_pid_to_str (tp
->ptid
).c_str ());
5611 fprintf_unfiltered (gdb_stdlog
,
5612 "infrun: restart threads: [%s] resumed\n",
5613 target_pid_to_str (tp
->ptid
).c_str ());
5614 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5618 if (thread_is_in_step_over_chain (tp
))
5621 fprintf_unfiltered (gdb_stdlog
,
5622 "infrun: restart threads: "
5623 "[%s] needs step-over\n",
5624 target_pid_to_str (tp
->ptid
).c_str ());
5625 gdb_assert (!tp
->resumed
);
5630 if (tp
->suspend
.waitstatus_pending_p
)
5633 fprintf_unfiltered (gdb_stdlog
,
5634 "infrun: restart threads: "
5635 "[%s] has pending status\n",
5636 target_pid_to_str (tp
->ptid
).c_str ());
5641 gdb_assert (!tp
->stop_requested
);
5643 /* If some thread needs to start a step-over at this point, it
5644 should still be in the step-over queue, and thus skipped
5646 if (thread_still_needs_step_over (tp
))
5648 internal_error (__FILE__
, __LINE__
,
5649 "thread [%s] needs a step-over, but not in "
5650 "step-over queue\n",
5651 target_pid_to_str (tp
->ptid
).c_str ());
5654 if (currently_stepping (tp
))
5657 fprintf_unfiltered (gdb_stdlog
,
5658 "infrun: restart threads: [%s] was stepping\n",
5659 target_pid_to_str (tp
->ptid
).c_str ());
5660 keep_going_stepped_thread (tp
);
5664 struct execution_control_state ecss
;
5665 struct execution_control_state
*ecs
= &ecss
;
5668 fprintf_unfiltered (gdb_stdlog
,
5669 "infrun: restart threads: [%s] continuing\n",
5670 target_pid_to_str (tp
->ptid
).c_str ());
5671 reset_ecs (ecs
, tp
);
5672 switch_to_thread (tp
);
5673 keep_going_pass_signal (ecs
);
5678 /* Callback for iterate_over_threads. Find a resumed thread that has
5679 a pending waitstatus. */
5682 resumed_thread_with_pending_status (struct thread_info
*tp
,
5686 && tp
->suspend
.waitstatus_pending_p
);
5689 /* Called when we get an event that may finish an in-line or
5690 out-of-line (displaced stepping) step-over started previously.
5691 Return true if the event is processed and we should go back to the
5692 event loop; false if the caller should continue processing the
5696 finish_step_over (struct execution_control_state
*ecs
)
5698 int had_step_over_info
;
5700 displaced_step_fixup (ecs
->event_thread
,
5701 ecs
->event_thread
->suspend
.stop_signal
);
5703 had_step_over_info
= step_over_info_valid_p ();
5705 if (had_step_over_info
)
5707 /* If we're stepping over a breakpoint with all threads locked,
5708 then only the thread that was stepped should be reporting
5710 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5712 clear_step_over_info ();
5715 if (!target_is_non_stop_p ())
5718 /* Start a new step-over in another thread if there's one that
5722 /* If we were stepping over a breakpoint before, and haven't started
5723 a new in-line step-over sequence, then restart all other threads
5724 (except the event thread). We can't do this in all-stop, as then
5725 e.g., we wouldn't be able to issue any other remote packet until
5726 these other threads stop. */
5727 if (had_step_over_info
&& !step_over_info_valid_p ())
5729 struct thread_info
*pending
;
5731 /* If we only have threads with pending statuses, the restart
5732 below won't restart any thread and so nothing re-inserts the
5733 breakpoint we just stepped over. But we need it inserted
5734 when we later process the pending events, otherwise if
5735 another thread has a pending event for this breakpoint too,
5736 we'd discard its event (because the breakpoint that
5737 originally caused the event was no longer inserted). */
5738 context_switch (ecs
);
5739 insert_breakpoints ();
5742 scoped_restore save_defer_tc
5743 = make_scoped_defer_target_commit_resume ();
5744 restart_threads (ecs
->event_thread
);
5746 target_commit_resume ();
5748 /* If we have events pending, go through handle_inferior_event
5749 again, picking up a pending event at random. This avoids
5750 thread starvation. */
5752 /* But not if we just stepped over a watchpoint in order to let
5753 the instruction execute so we can evaluate its expression.
5754 The set of watchpoints that triggered is recorded in the
5755 breakpoint objects themselves (see bp->watchpoint_triggered).
5756 If we processed another event first, that other event could
5757 clobber this info. */
5758 if (ecs
->event_thread
->stepping_over_watchpoint
)
5761 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5763 if (pending
!= NULL
)
5765 struct thread_info
*tp
= ecs
->event_thread
;
5766 struct regcache
*regcache
;
5770 fprintf_unfiltered (gdb_stdlog
,
5771 "infrun: found resumed threads with "
5772 "pending events, saving status\n");
5775 gdb_assert (pending
!= tp
);
5777 /* Record the event thread's event for later. */
5778 save_waitstatus (tp
, &ecs
->ws
);
5779 /* This was cleared early, by handle_inferior_event. Set it
5780 so this pending event is considered by
5784 gdb_assert (!tp
->executing
);
5786 regcache
= get_thread_regcache (tp
);
5787 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5791 fprintf_unfiltered (gdb_stdlog
,
5792 "infrun: saved stop_pc=%s for %s "
5793 "(currently_stepping=%d)\n",
5794 paddress (target_gdbarch (),
5795 tp
->suspend
.stop_pc
),
5796 target_pid_to_str (tp
->ptid
).c_str (),
5797 currently_stepping (tp
));
5800 /* This in-line step-over finished; clear this so we won't
5801 start a new one. This is what handle_signal_stop would
5802 do, if we returned false. */
5803 tp
->stepping_over_breakpoint
= 0;
5805 /* Wake up the event loop again. */
5806 mark_async_event_handler (infrun_async_inferior_event_token
);
5808 prepare_to_wait (ecs
);
5816 /* Come here when the program has stopped with a signal. */
5819 handle_signal_stop (struct execution_control_state
*ecs
)
5821 struct frame_info
*frame
;
5822 struct gdbarch
*gdbarch
;
5823 int stopped_by_watchpoint
;
5824 enum stop_kind stop_soon
;
5827 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5829 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5831 /* Do we need to clean up the state of a thread that has
5832 completed a displaced single-step? (Doing so usually affects
5833 the PC, so do it here, before we set stop_pc.) */
5834 if (finish_step_over (ecs
))
5837 /* If we either finished a single-step or hit a breakpoint, but
5838 the user wanted this thread to be stopped, pretend we got a
5839 SIG0 (generic unsignaled stop). */
5840 if (ecs
->event_thread
->stop_requested
5841 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5842 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5844 ecs
->event_thread
->suspend
.stop_pc
5845 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5849 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5850 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5852 switch_to_thread (ecs
->event_thread
);
5854 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5855 paddress (reg_gdbarch
,
5856 ecs
->event_thread
->suspend
.stop_pc
));
5857 if (target_stopped_by_watchpoint ())
5861 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5863 if (target_stopped_data_address (current_top_target (), &addr
))
5864 fprintf_unfiltered (gdb_stdlog
,
5865 "infrun: stopped data address = %s\n",
5866 paddress (reg_gdbarch
, addr
));
5868 fprintf_unfiltered (gdb_stdlog
,
5869 "infrun: (no data address available)\n");
5873 /* This is originated from start_remote(), start_inferior() and
5874 shared libraries hook functions. */
5875 stop_soon
= get_inferior_stop_soon (ecs
);
5876 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5878 context_switch (ecs
);
5880 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5881 stop_print_frame
= 1;
5886 /* This originates from attach_command(). We need to overwrite
5887 the stop_signal here, because some kernels don't ignore a
5888 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5889 See more comments in inferior.h. On the other hand, if we
5890 get a non-SIGSTOP, report it to the user - assume the backend
5891 will handle the SIGSTOP if it should show up later.
5893 Also consider that the attach is complete when we see a
5894 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5895 target extended-remote report it instead of a SIGSTOP
5896 (e.g. gdbserver). We already rely on SIGTRAP being our
5897 signal, so this is no exception.
5899 Also consider that the attach is complete when we see a
5900 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5901 the target to stop all threads of the inferior, in case the
5902 low level attach operation doesn't stop them implicitly. If
5903 they weren't stopped implicitly, then the stub will report a
5904 GDB_SIGNAL_0, meaning: stopped for no particular reason
5905 other than GDB's request. */
5906 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5907 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5908 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5909 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5911 stop_print_frame
= 1;
5913 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5917 /* See if something interesting happened to the non-current thread. If
5918 so, then switch to that thread. */
5919 if (ecs
->ptid
!= inferior_ptid
)
5922 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5924 context_switch (ecs
);
5926 if (deprecated_context_hook
)
5927 deprecated_context_hook (ecs
->event_thread
->global_num
);
5930 /* At this point, get hold of the now-current thread's frame. */
5931 frame
= get_current_frame ();
5932 gdbarch
= get_frame_arch (frame
);
5934 /* Pull the single step breakpoints out of the target. */
5935 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5937 struct regcache
*regcache
;
5940 regcache
= get_thread_regcache (ecs
->event_thread
);
5941 const address_space
*aspace
= regcache
->aspace ();
5943 pc
= regcache_read_pc (regcache
);
5945 /* However, before doing so, if this single-step breakpoint was
5946 actually for another thread, set this thread up for moving
5948 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5951 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5955 fprintf_unfiltered (gdb_stdlog
,
5956 "infrun: [%s] hit another thread's "
5957 "single-step breakpoint\n",
5958 target_pid_to_str (ecs
->ptid
).c_str ());
5960 ecs
->hit_singlestep_breakpoint
= 1;
5967 fprintf_unfiltered (gdb_stdlog
,
5968 "infrun: [%s] hit its "
5969 "single-step breakpoint\n",
5970 target_pid_to_str (ecs
->ptid
).c_str ());
5974 delete_just_stopped_threads_single_step_breakpoints ();
5976 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5977 && ecs
->event_thread
->control
.trap_expected
5978 && ecs
->event_thread
->stepping_over_watchpoint
)
5979 stopped_by_watchpoint
= 0;
5981 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5983 /* If necessary, step over this watchpoint. We'll be back to display
5985 if (stopped_by_watchpoint
5986 && (target_have_steppable_watchpoint
5987 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5989 /* At this point, we are stopped at an instruction which has
5990 attempted to write to a piece of memory under control of
5991 a watchpoint. The instruction hasn't actually executed
5992 yet. If we were to evaluate the watchpoint expression
5993 now, we would get the old value, and therefore no change
5994 would seem to have occurred.
5996 In order to make watchpoints work `right', we really need
5997 to complete the memory write, and then evaluate the
5998 watchpoint expression. We do this by single-stepping the
6001 It may not be necessary to disable the watchpoint to step over
6002 it. For example, the PA can (with some kernel cooperation)
6003 single step over a watchpoint without disabling the watchpoint.
6005 It is far more common to need to disable a watchpoint to step
6006 the inferior over it. If we have non-steppable watchpoints,
6007 we must disable the current watchpoint; it's simplest to
6008 disable all watchpoints.
6010 Any breakpoint at PC must also be stepped over -- if there's
6011 one, it will have already triggered before the watchpoint
6012 triggered, and we either already reported it to the user, or
6013 it didn't cause a stop and we called keep_going. In either
6014 case, if there was a breakpoint at PC, we must be trying to
6016 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6021 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6022 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6023 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6024 ecs
->event_thread
->control
.stop_step
= 0;
6025 stop_print_frame
= 1;
6026 stopped_by_random_signal
= 0;
6027 bpstat stop_chain
= NULL
;
6029 /* Hide inlined functions starting here, unless we just performed stepi or
6030 nexti. After stepi and nexti, always show the innermost frame (not any
6031 inline function call sites). */
6032 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6034 const address_space
*aspace
6035 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6037 /* skip_inline_frames is expensive, so we avoid it if we can
6038 determine that the address is one where functions cannot have
6039 been inlined. This improves performance with inferiors that
6040 load a lot of shared libraries, because the solib event
6041 breakpoint is defined as the address of a function (i.e. not
6042 inline). Note that we have to check the previous PC as well
6043 as the current one to catch cases when we have just
6044 single-stepped off a breakpoint prior to reinstating it.
6045 Note that we're assuming that the code we single-step to is
6046 not inline, but that's not definitive: there's nothing
6047 preventing the event breakpoint function from containing
6048 inlined code, and the single-step ending up there. If the
6049 user had set a breakpoint on that inlined code, the missing
6050 skip_inline_frames call would break things. Fortunately
6051 that's an extremely unlikely scenario. */
6052 if (!pc_at_non_inline_function (aspace
,
6053 ecs
->event_thread
->suspend
.stop_pc
,
6055 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6056 && ecs
->event_thread
->control
.trap_expected
6057 && pc_at_non_inline_function (aspace
,
6058 ecs
->event_thread
->prev_pc
,
6061 stop_chain
= build_bpstat_chain (aspace
,
6062 ecs
->event_thread
->suspend
.stop_pc
,
6064 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6066 /* Re-fetch current thread's frame in case that invalidated
6068 frame
= get_current_frame ();
6069 gdbarch
= get_frame_arch (frame
);
6073 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6074 && ecs
->event_thread
->control
.trap_expected
6075 && gdbarch_single_step_through_delay_p (gdbarch
)
6076 && currently_stepping (ecs
->event_thread
))
6078 /* We're trying to step off a breakpoint. Turns out that we're
6079 also on an instruction that needs to be stepped multiple
6080 times before it's been fully executing. E.g., architectures
6081 with a delay slot. It needs to be stepped twice, once for
6082 the instruction and once for the delay slot. */
6083 int step_through_delay
6084 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6086 if (debug_infrun
&& step_through_delay
)
6087 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6088 if (ecs
->event_thread
->control
.step_range_end
== 0
6089 && step_through_delay
)
6091 /* The user issued a continue when stopped at a breakpoint.
6092 Set up for another trap and get out of here. */
6093 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6097 else if (step_through_delay
)
6099 /* The user issued a step when stopped at a breakpoint.
6100 Maybe we should stop, maybe we should not - the delay
6101 slot *might* correspond to a line of source. In any
6102 case, don't decide that here, just set
6103 ecs->stepping_over_breakpoint, making sure we
6104 single-step again before breakpoints are re-inserted. */
6105 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6109 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6110 handles this event. */
6111 ecs
->event_thread
->control
.stop_bpstat
6112 = bpstat_stop_status (get_current_regcache ()->aspace (),
6113 ecs
->event_thread
->suspend
.stop_pc
,
6114 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6116 /* Following in case break condition called a
6118 stop_print_frame
= 1;
6120 /* This is where we handle "moribund" watchpoints. Unlike
6121 software breakpoints traps, hardware watchpoint traps are
6122 always distinguishable from random traps. If no high-level
6123 watchpoint is associated with the reported stop data address
6124 anymore, then the bpstat does not explain the signal ---
6125 simply make sure to ignore it if `stopped_by_watchpoint' is
6129 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6130 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6132 && stopped_by_watchpoint
)
6133 fprintf_unfiltered (gdb_stdlog
,
6134 "infrun: no user watchpoint explains "
6135 "watchpoint SIGTRAP, ignoring\n");
6137 /* NOTE: cagney/2003-03-29: These checks for a random signal
6138 at one stage in the past included checks for an inferior
6139 function call's call dummy's return breakpoint. The original
6140 comment, that went with the test, read:
6142 ``End of a stack dummy. Some systems (e.g. Sony news) give
6143 another signal besides SIGTRAP, so check here as well as
6146 If someone ever tries to get call dummys on a
6147 non-executable stack to work (where the target would stop
6148 with something like a SIGSEGV), then those tests might need
6149 to be re-instated. Given, however, that the tests were only
6150 enabled when momentary breakpoints were not being used, I
6151 suspect that it won't be the case.
6153 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6154 be necessary for call dummies on a non-executable stack on
6157 /* See if the breakpoints module can explain the signal. */
6159 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6160 ecs
->event_thread
->suspend
.stop_signal
);
6162 /* Maybe this was a trap for a software breakpoint that has since
6164 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6166 if (program_breakpoint_here_p (gdbarch
,
6167 ecs
->event_thread
->suspend
.stop_pc
))
6169 struct regcache
*regcache
;
6172 /* Re-adjust PC to what the program would see if GDB was not
6174 regcache
= get_thread_regcache (ecs
->event_thread
);
6175 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6178 gdb::optional
<scoped_restore_tmpl
<int>>
6179 restore_operation_disable
;
6181 if (record_full_is_used ())
6182 restore_operation_disable
.emplace
6183 (record_full_gdb_operation_disable_set ());
6185 regcache_write_pc (regcache
,
6186 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6191 /* A delayed software breakpoint event. Ignore the trap. */
6193 fprintf_unfiltered (gdb_stdlog
,
6194 "infrun: delayed software breakpoint "
6195 "trap, ignoring\n");
6200 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6201 has since been removed. */
6202 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6204 /* A delayed hardware breakpoint event. Ignore the trap. */
6206 fprintf_unfiltered (gdb_stdlog
,
6207 "infrun: delayed hardware breakpoint/watchpoint "
6208 "trap, ignoring\n");
6212 /* If not, perhaps stepping/nexting can. */
6214 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6215 && currently_stepping (ecs
->event_thread
));
6217 /* Perhaps the thread hit a single-step breakpoint of _another_
6218 thread. Single-step breakpoints are transparent to the
6219 breakpoints module. */
6221 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6223 /* No? Perhaps we got a moribund watchpoint. */
6225 random_signal
= !stopped_by_watchpoint
;
6227 /* Always stop if the user explicitly requested this thread to
6229 if (ecs
->event_thread
->stop_requested
)
6233 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6236 /* For the program's own signals, act according to
6237 the signal handling tables. */
6241 /* Signal not for debugging purposes. */
6242 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6243 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6246 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6247 gdb_signal_to_symbol_string (stop_signal
));
6249 stopped_by_random_signal
= 1;
6251 /* Always stop on signals if we're either just gaining control
6252 of the program, or the user explicitly requested this thread
6253 to remain stopped. */
6254 if (stop_soon
!= NO_STOP_QUIETLY
6255 || ecs
->event_thread
->stop_requested
6257 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6263 /* Notify observers the signal has "handle print" set. Note we
6264 returned early above if stopping; normal_stop handles the
6265 printing in that case. */
6266 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6268 /* The signal table tells us to print about this signal. */
6269 target_terminal::ours_for_output ();
6270 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6271 target_terminal::inferior ();
6274 /* Clear the signal if it should not be passed. */
6275 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6276 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6278 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6279 && ecs
->event_thread
->control
.trap_expected
6280 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6282 /* We were just starting a new sequence, attempting to
6283 single-step off of a breakpoint and expecting a SIGTRAP.
6284 Instead this signal arrives. This signal will take us out
6285 of the stepping range so GDB needs to remember to, when
6286 the signal handler returns, resume stepping off that
6288 /* To simplify things, "continue" is forced to use the same
6289 code paths as single-step - set a breakpoint at the
6290 signal return address and then, once hit, step off that
6293 fprintf_unfiltered (gdb_stdlog
,
6294 "infrun: signal arrived while stepping over "
6297 insert_hp_step_resume_breakpoint_at_frame (frame
);
6298 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6299 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6300 ecs
->event_thread
->control
.trap_expected
= 0;
6302 /* If we were nexting/stepping some other thread, switch to
6303 it, so that we don't continue it, losing control. */
6304 if (!switch_back_to_stepped_thread (ecs
))
6309 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6310 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6312 || ecs
->event_thread
->control
.step_range_end
== 1)
6313 && frame_id_eq (get_stack_frame_id (frame
),
6314 ecs
->event_thread
->control
.step_stack_frame_id
)
6315 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6317 /* The inferior is about to take a signal that will take it
6318 out of the single step range. Set a breakpoint at the
6319 current PC (which is presumably where the signal handler
6320 will eventually return) and then allow the inferior to
6323 Note that this is only needed for a signal delivered
6324 while in the single-step range. Nested signals aren't a
6325 problem as they eventually all return. */
6327 fprintf_unfiltered (gdb_stdlog
,
6328 "infrun: signal may take us out of "
6329 "single-step range\n");
6331 clear_step_over_info ();
6332 insert_hp_step_resume_breakpoint_at_frame (frame
);
6333 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6334 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6335 ecs
->event_thread
->control
.trap_expected
= 0;
6340 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6341 when either there's a nested signal, or when there's a
6342 pending signal enabled just as the signal handler returns
6343 (leaving the inferior at the step-resume-breakpoint without
6344 actually executing it). Either way continue until the
6345 breakpoint is really hit. */
6347 if (!switch_back_to_stepped_thread (ecs
))
6350 fprintf_unfiltered (gdb_stdlog
,
6351 "infrun: random signal, keep going\n");
6358 process_event_stop_test (ecs
);
6361 /* Come here when we've got some debug event / signal we can explain
6362 (IOW, not a random signal), and test whether it should cause a
6363 stop, or whether we should resume the inferior (transparently).
6364 E.g., could be a breakpoint whose condition evaluates false; we
6365 could be still stepping within the line; etc. */
6368 process_event_stop_test (struct execution_control_state
*ecs
)
6370 struct symtab_and_line stop_pc_sal
;
6371 struct frame_info
*frame
;
6372 struct gdbarch
*gdbarch
;
6373 CORE_ADDR jmp_buf_pc
;
6374 struct bpstat_what what
;
6376 /* Handle cases caused by hitting a breakpoint. */
6378 frame
= get_current_frame ();
6379 gdbarch
= get_frame_arch (frame
);
6381 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6383 if (what
.call_dummy
)
6385 stop_stack_dummy
= what
.call_dummy
;
6388 /* A few breakpoint types have callbacks associated (e.g.,
6389 bp_jit_event). Run them now. */
6390 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6392 /* If we hit an internal event that triggers symbol changes, the
6393 current frame will be invalidated within bpstat_what (e.g., if we
6394 hit an internal solib event). Re-fetch it. */
6395 frame
= get_current_frame ();
6396 gdbarch
= get_frame_arch (frame
);
6398 switch (what
.main_action
)
6400 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6401 /* If we hit the breakpoint at longjmp while stepping, we
6402 install a momentary breakpoint at the target of the
6406 fprintf_unfiltered (gdb_stdlog
,
6407 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6409 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6411 if (what
.is_longjmp
)
6413 struct value
*arg_value
;
6415 /* If we set the longjmp breakpoint via a SystemTap probe,
6416 then use it to extract the arguments. The destination PC
6417 is the third argument to the probe. */
6418 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6421 jmp_buf_pc
= value_as_address (arg_value
);
6422 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6424 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6425 || !gdbarch_get_longjmp_target (gdbarch
,
6426 frame
, &jmp_buf_pc
))
6429 fprintf_unfiltered (gdb_stdlog
,
6430 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6431 "(!gdbarch_get_longjmp_target)\n");
6436 /* Insert a breakpoint at resume address. */
6437 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6440 check_exception_resume (ecs
, frame
);
6444 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6446 struct frame_info
*init_frame
;
6448 /* There are several cases to consider.
6450 1. The initiating frame no longer exists. In this case we
6451 must stop, because the exception or longjmp has gone too
6454 2. The initiating frame exists, and is the same as the
6455 current frame. We stop, because the exception or longjmp
6458 3. The initiating frame exists and is different from the
6459 current frame. This means the exception or longjmp has
6460 been caught beneath the initiating frame, so keep going.
6462 4. longjmp breakpoint has been placed just to protect
6463 against stale dummy frames and user is not interested in
6464 stopping around longjmps. */
6467 fprintf_unfiltered (gdb_stdlog
,
6468 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6470 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6472 delete_exception_resume_breakpoint (ecs
->event_thread
);
6474 if (what
.is_longjmp
)
6476 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6478 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6486 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6490 struct frame_id current_id
6491 = get_frame_id (get_current_frame ());
6492 if (frame_id_eq (current_id
,
6493 ecs
->event_thread
->initiating_frame
))
6495 /* Case 2. Fall through. */
6505 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6507 delete_step_resume_breakpoint (ecs
->event_thread
);
6509 end_stepping_range (ecs
);
6513 case BPSTAT_WHAT_SINGLE
:
6515 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6516 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6517 /* Still need to check other stuff, at least the case where we
6518 are stepping and step out of the right range. */
6521 case BPSTAT_WHAT_STEP_RESUME
:
6523 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6525 delete_step_resume_breakpoint (ecs
->event_thread
);
6526 if (ecs
->event_thread
->control
.proceed_to_finish
6527 && execution_direction
== EXEC_REVERSE
)
6529 struct thread_info
*tp
= ecs
->event_thread
;
6531 /* We are finishing a function in reverse, and just hit the
6532 step-resume breakpoint at the start address of the
6533 function, and we're almost there -- just need to back up
6534 by one more single-step, which should take us back to the
6536 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6540 fill_in_stop_func (gdbarch
, ecs
);
6541 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6542 && execution_direction
== EXEC_REVERSE
)
6544 /* We are stepping over a function call in reverse, and just
6545 hit the step-resume breakpoint at the start address of
6546 the function. Go back to single-stepping, which should
6547 take us back to the function call. */
6548 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6554 case BPSTAT_WHAT_STOP_NOISY
:
6556 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6557 stop_print_frame
= 1;
6559 /* Assume the thread stopped for a breapoint. We'll still check
6560 whether a/the breakpoint is there when the thread is next
6562 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6567 case BPSTAT_WHAT_STOP_SILENT
:
6569 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6570 stop_print_frame
= 0;
6572 /* Assume the thread stopped for a breapoint. We'll still check
6573 whether a/the breakpoint is there when the thread is next
6575 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6579 case BPSTAT_WHAT_HP_STEP_RESUME
:
6581 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6583 delete_step_resume_breakpoint (ecs
->event_thread
);
6584 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6586 /* Back when the step-resume breakpoint was inserted, we
6587 were trying to single-step off a breakpoint. Go back to
6589 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6590 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6596 case BPSTAT_WHAT_KEEP_CHECKING
:
6600 /* If we stepped a permanent breakpoint and we had a high priority
6601 step-resume breakpoint for the address we stepped, but we didn't
6602 hit it, then we must have stepped into the signal handler. The
6603 step-resume was only necessary to catch the case of _not_
6604 stepping into the handler, so delete it, and fall through to
6605 checking whether the step finished. */
6606 if (ecs
->event_thread
->stepped_breakpoint
)
6608 struct breakpoint
*sr_bp
6609 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6612 && sr_bp
->loc
->permanent
6613 && sr_bp
->type
== bp_hp_step_resume
6614 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6617 fprintf_unfiltered (gdb_stdlog
,
6618 "infrun: stepped permanent breakpoint, stopped in "
6620 delete_step_resume_breakpoint (ecs
->event_thread
);
6621 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6625 /* We come here if we hit a breakpoint but should not stop for it.
6626 Possibly we also were stepping and should stop for that. So fall
6627 through and test for stepping. But, if not stepping, do not
6630 /* In all-stop mode, if we're currently stepping but have stopped in
6631 some other thread, we need to switch back to the stepped thread. */
6632 if (switch_back_to_stepped_thread (ecs
))
6635 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6638 fprintf_unfiltered (gdb_stdlog
,
6639 "infrun: step-resume breakpoint is inserted\n");
6641 /* Having a step-resume breakpoint overrides anything
6642 else having to do with stepping commands until
6643 that breakpoint is reached. */
6648 if (ecs
->event_thread
->control
.step_range_end
== 0)
6651 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6652 /* Likewise if we aren't even stepping. */
6657 /* Re-fetch current thread's frame in case the code above caused
6658 the frame cache to be re-initialized, making our FRAME variable
6659 a dangling pointer. */
6660 frame
= get_current_frame ();
6661 gdbarch
= get_frame_arch (frame
);
6662 fill_in_stop_func (gdbarch
, ecs
);
6664 /* If stepping through a line, keep going if still within it.
6666 Note that step_range_end is the address of the first instruction
6667 beyond the step range, and NOT the address of the last instruction
6670 Note also that during reverse execution, we may be stepping
6671 through a function epilogue and therefore must detect when
6672 the current-frame changes in the middle of a line. */
6674 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6676 && (execution_direction
!= EXEC_REVERSE
6677 || frame_id_eq (get_frame_id (frame
),
6678 ecs
->event_thread
->control
.step_frame_id
)))
6682 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6683 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6684 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6686 /* Tentatively re-enable range stepping; `resume' disables it if
6687 necessary (e.g., if we're stepping over a breakpoint or we
6688 have software watchpoints). */
6689 ecs
->event_thread
->control
.may_range_step
= 1;
6691 /* When stepping backward, stop at beginning of line range
6692 (unless it's the function entry point, in which case
6693 keep going back to the call point). */
6694 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6695 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6696 && stop_pc
!= ecs
->stop_func_start
6697 && execution_direction
== EXEC_REVERSE
)
6698 end_stepping_range (ecs
);
6705 /* We stepped out of the stepping range. */
6707 /* If we are stepping at the source level and entered the runtime
6708 loader dynamic symbol resolution code...
6710 EXEC_FORWARD: we keep on single stepping until we exit the run
6711 time loader code and reach the callee's address.
6713 EXEC_REVERSE: we've already executed the callee (backward), and
6714 the runtime loader code is handled just like any other
6715 undebuggable function call. Now we need only keep stepping
6716 backward through the trampoline code, and that's handled further
6717 down, so there is nothing for us to do here. */
6719 if (execution_direction
!= EXEC_REVERSE
6720 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6721 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6723 CORE_ADDR pc_after_resolver
=
6724 gdbarch_skip_solib_resolver (gdbarch
,
6725 ecs
->event_thread
->suspend
.stop_pc
);
6728 fprintf_unfiltered (gdb_stdlog
,
6729 "infrun: stepped into dynsym resolve code\n");
6731 if (pc_after_resolver
)
6733 /* Set up a step-resume breakpoint at the address
6734 indicated by SKIP_SOLIB_RESOLVER. */
6735 symtab_and_line sr_sal
;
6736 sr_sal
.pc
= pc_after_resolver
;
6737 sr_sal
.pspace
= get_frame_program_space (frame
);
6739 insert_step_resume_breakpoint_at_sal (gdbarch
,
6740 sr_sal
, null_frame_id
);
6747 /* Step through an indirect branch thunk. */
6748 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6749 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6750 ecs
->event_thread
->suspend
.stop_pc
))
6753 fprintf_unfiltered (gdb_stdlog
,
6754 "infrun: stepped into indirect branch thunk\n");
6759 if (ecs
->event_thread
->control
.step_range_end
!= 1
6760 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6761 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6762 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6765 fprintf_unfiltered (gdb_stdlog
,
6766 "infrun: stepped into signal trampoline\n");
6767 /* The inferior, while doing a "step" or "next", has ended up in
6768 a signal trampoline (either by a signal being delivered or by
6769 the signal handler returning). Just single-step until the
6770 inferior leaves the trampoline (either by calling the handler
6776 /* If we're in the return path from a shared library trampoline,
6777 we want to proceed through the trampoline when stepping. */
6778 /* macro/2012-04-25: This needs to come before the subroutine
6779 call check below as on some targets return trampolines look
6780 like subroutine calls (MIPS16 return thunks). */
6781 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6782 ecs
->event_thread
->suspend
.stop_pc
,
6783 ecs
->stop_func_name
)
6784 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6786 /* Determine where this trampoline returns. */
6787 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6788 CORE_ADDR real_stop_pc
6789 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6792 fprintf_unfiltered (gdb_stdlog
,
6793 "infrun: stepped into solib return tramp\n");
6795 /* Only proceed through if we know where it's going. */
6798 /* And put the step-breakpoint there and go until there. */
6799 symtab_and_line sr_sal
;
6800 sr_sal
.pc
= real_stop_pc
;
6801 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6802 sr_sal
.pspace
= get_frame_program_space (frame
);
6804 /* Do not specify what the fp should be when we stop since
6805 on some machines the prologue is where the new fp value
6807 insert_step_resume_breakpoint_at_sal (gdbarch
,
6808 sr_sal
, null_frame_id
);
6810 /* Restart without fiddling with the step ranges or
6817 /* Check for subroutine calls. The check for the current frame
6818 equalling the step ID is not necessary - the check of the
6819 previous frame's ID is sufficient - but it is a common case and
6820 cheaper than checking the previous frame's ID.
6822 NOTE: frame_id_eq will never report two invalid frame IDs as
6823 being equal, so to get into this block, both the current and
6824 previous frame must have valid frame IDs. */
6825 /* The outer_frame_id check is a heuristic to detect stepping
6826 through startup code. If we step over an instruction which
6827 sets the stack pointer from an invalid value to a valid value,
6828 we may detect that as a subroutine call from the mythical
6829 "outermost" function. This could be fixed by marking
6830 outermost frames as !stack_p,code_p,special_p. Then the
6831 initial outermost frame, before sp was valid, would
6832 have code_addr == &_start. See the comment in frame_id_eq
6834 if (!frame_id_eq (get_stack_frame_id (frame
),
6835 ecs
->event_thread
->control
.step_stack_frame_id
)
6836 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6837 ecs
->event_thread
->control
.step_stack_frame_id
)
6838 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6840 || (ecs
->event_thread
->control
.step_start_function
6841 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6843 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6844 CORE_ADDR real_stop_pc
;
6847 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6849 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6851 /* I presume that step_over_calls is only 0 when we're
6852 supposed to be stepping at the assembly language level
6853 ("stepi"). Just stop. */
6854 /* And this works the same backward as frontward. MVS */
6855 end_stepping_range (ecs
);
6859 /* Reverse stepping through solib trampolines. */
6861 if (execution_direction
== EXEC_REVERSE
6862 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6863 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6864 || (ecs
->stop_func_start
== 0
6865 && in_solib_dynsym_resolve_code (stop_pc
))))
6867 /* Any solib trampoline code can be handled in reverse
6868 by simply continuing to single-step. We have already
6869 executed the solib function (backwards), and a few
6870 steps will take us back through the trampoline to the
6876 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6878 /* We're doing a "next".
6880 Normal (forward) execution: set a breakpoint at the
6881 callee's return address (the address at which the caller
6884 Reverse (backward) execution. set the step-resume
6885 breakpoint at the start of the function that we just
6886 stepped into (backwards), and continue to there. When we
6887 get there, we'll need to single-step back to the caller. */
6889 if (execution_direction
== EXEC_REVERSE
)
6891 /* If we're already at the start of the function, we've either
6892 just stepped backward into a single instruction function,
6893 or stepped back out of a signal handler to the first instruction
6894 of the function. Just keep going, which will single-step back
6896 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6898 /* Normal function call return (static or dynamic). */
6899 symtab_and_line sr_sal
;
6900 sr_sal
.pc
= ecs
->stop_func_start
;
6901 sr_sal
.pspace
= get_frame_program_space (frame
);
6902 insert_step_resume_breakpoint_at_sal (gdbarch
,
6903 sr_sal
, null_frame_id
);
6907 insert_step_resume_breakpoint_at_caller (frame
);
6913 /* If we are in a function call trampoline (a stub between the
6914 calling routine and the real function), locate the real
6915 function. That's what tells us (a) whether we want to step
6916 into it at all, and (b) what prologue we want to run to the
6917 end of, if we do step into it. */
6918 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6919 if (real_stop_pc
== 0)
6920 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6921 if (real_stop_pc
!= 0)
6922 ecs
->stop_func_start
= real_stop_pc
;
6924 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6926 symtab_and_line sr_sal
;
6927 sr_sal
.pc
= ecs
->stop_func_start
;
6928 sr_sal
.pspace
= get_frame_program_space (frame
);
6930 insert_step_resume_breakpoint_at_sal (gdbarch
,
6931 sr_sal
, null_frame_id
);
6936 /* If we have line number information for the function we are
6937 thinking of stepping into and the function isn't on the skip
6940 If there are several symtabs at that PC (e.g. with include
6941 files), just want to know whether *any* of them have line
6942 numbers. find_pc_line handles this. */
6944 struct symtab_and_line tmp_sal
;
6946 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6947 if (tmp_sal
.line
!= 0
6948 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6950 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6952 if (execution_direction
== EXEC_REVERSE
)
6953 handle_step_into_function_backward (gdbarch
, ecs
);
6955 handle_step_into_function (gdbarch
, ecs
);
6960 /* If we have no line number and the step-stop-if-no-debug is
6961 set, we stop the step so that the user has a chance to switch
6962 in assembly mode. */
6963 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6964 && step_stop_if_no_debug
)
6966 end_stepping_range (ecs
);
6970 if (execution_direction
== EXEC_REVERSE
)
6972 /* If we're already at the start of the function, we've either just
6973 stepped backward into a single instruction function without line
6974 number info, or stepped back out of a signal handler to the first
6975 instruction of the function without line number info. Just keep
6976 going, which will single-step back to the caller. */
6977 if (ecs
->stop_func_start
!= stop_pc
)
6979 /* Set a breakpoint at callee's start address.
6980 From there we can step once and be back in the caller. */
6981 symtab_and_line sr_sal
;
6982 sr_sal
.pc
= ecs
->stop_func_start
;
6983 sr_sal
.pspace
= get_frame_program_space (frame
);
6984 insert_step_resume_breakpoint_at_sal (gdbarch
,
6985 sr_sal
, null_frame_id
);
6989 /* Set a breakpoint at callee's return address (the address
6990 at which the caller will resume). */
6991 insert_step_resume_breakpoint_at_caller (frame
);
6997 /* Reverse stepping through solib trampolines. */
6999 if (execution_direction
== EXEC_REVERSE
7000 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7002 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7004 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7005 || (ecs
->stop_func_start
== 0
7006 && in_solib_dynsym_resolve_code (stop_pc
)))
7008 /* Any solib trampoline code can be handled in reverse
7009 by simply continuing to single-step. We have already
7010 executed the solib function (backwards), and a few
7011 steps will take us back through the trampoline to the
7016 else if (in_solib_dynsym_resolve_code (stop_pc
))
7018 /* Stepped backward into the solib dynsym resolver.
7019 Set a breakpoint at its start and continue, then
7020 one more step will take us out. */
7021 symtab_and_line sr_sal
;
7022 sr_sal
.pc
= ecs
->stop_func_start
;
7023 sr_sal
.pspace
= get_frame_program_space (frame
);
7024 insert_step_resume_breakpoint_at_sal (gdbarch
,
7025 sr_sal
, null_frame_id
);
7031 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7033 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7034 the trampoline processing logic, however, there are some trampolines
7035 that have no names, so we should do trampoline handling first. */
7036 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7037 && ecs
->stop_func_name
== NULL
7038 && stop_pc_sal
.line
== 0)
7041 fprintf_unfiltered (gdb_stdlog
,
7042 "infrun: stepped into undebuggable function\n");
7044 /* The inferior just stepped into, or returned to, an
7045 undebuggable function (where there is no debugging information
7046 and no line number corresponding to the address where the
7047 inferior stopped). Since we want to skip this kind of code,
7048 we keep going until the inferior returns from this
7049 function - unless the user has asked us not to (via
7050 set step-mode) or we no longer know how to get back
7051 to the call site. */
7052 if (step_stop_if_no_debug
7053 || !frame_id_p (frame_unwind_caller_id (frame
)))
7055 /* If we have no line number and the step-stop-if-no-debug
7056 is set, we stop the step so that the user has a chance to
7057 switch in assembly mode. */
7058 end_stepping_range (ecs
);
7063 /* Set a breakpoint at callee's return address (the address
7064 at which the caller will resume). */
7065 insert_step_resume_breakpoint_at_caller (frame
);
7071 if (ecs
->event_thread
->control
.step_range_end
== 1)
7073 /* It is stepi or nexti. We always want to stop stepping after
7076 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7077 end_stepping_range (ecs
);
7081 if (stop_pc_sal
.line
== 0)
7083 /* We have no line number information. That means to stop
7084 stepping (does this always happen right after one instruction,
7085 when we do "s" in a function with no line numbers,
7086 or can this happen as a result of a return or longjmp?). */
7088 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7089 end_stepping_range (ecs
);
7093 /* Look for "calls" to inlined functions, part one. If the inline
7094 frame machinery detected some skipped call sites, we have entered
7095 a new inline function. */
7097 if (frame_id_eq (get_frame_id (get_current_frame ()),
7098 ecs
->event_thread
->control
.step_frame_id
)
7099 && inline_skipped_frames (ecs
->event_thread
))
7102 fprintf_unfiltered (gdb_stdlog
,
7103 "infrun: stepped into inlined function\n");
7105 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7107 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7109 /* For "step", we're going to stop. But if the call site
7110 for this inlined function is on the same source line as
7111 we were previously stepping, go down into the function
7112 first. Otherwise stop at the call site. */
7114 if (call_sal
.line
== ecs
->event_thread
->current_line
7115 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7117 step_into_inline_frame (ecs
->event_thread
);
7118 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7125 end_stepping_range (ecs
);
7130 /* For "next", we should stop at the call site if it is on a
7131 different source line. Otherwise continue through the
7132 inlined function. */
7133 if (call_sal
.line
== ecs
->event_thread
->current_line
7134 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7137 end_stepping_range (ecs
);
7142 /* Look for "calls" to inlined functions, part two. If we are still
7143 in the same real function we were stepping through, but we have
7144 to go further up to find the exact frame ID, we are stepping
7145 through a more inlined call beyond its call site. */
7147 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7148 && !frame_id_eq (get_frame_id (get_current_frame ()),
7149 ecs
->event_thread
->control
.step_frame_id
)
7150 && stepped_in_from (get_current_frame (),
7151 ecs
->event_thread
->control
.step_frame_id
))
7154 fprintf_unfiltered (gdb_stdlog
,
7155 "infrun: stepping through inlined function\n");
7157 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7158 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7161 end_stepping_range (ecs
);
7165 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7166 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7167 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7169 /* We are at the start of a different line. So stop. Note that
7170 we don't stop if we step into the middle of a different line.
7171 That is said to make things like for (;;) statements work
7174 fprintf_unfiltered (gdb_stdlog
,
7175 "infrun: stepped to a different line\n");
7176 end_stepping_range (ecs
);
7180 /* We aren't done stepping.
7182 Optimize by setting the stepping range to the line.
7183 (We might not be in the original line, but if we entered a
7184 new line in mid-statement, we continue stepping. This makes
7185 things like for(;;) statements work better.) */
7187 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7188 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7189 ecs
->event_thread
->control
.may_range_step
= 1;
7190 set_step_info (frame
, stop_pc_sal
);
7193 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7197 /* In all-stop mode, if we're currently stepping but have stopped in
7198 some other thread, we may need to switch back to the stepped
7199 thread. Returns true we set the inferior running, false if we left
7200 it stopped (and the event needs further processing). */
7203 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7205 if (!target_is_non_stop_p ())
7207 struct thread_info
*stepping_thread
;
7209 /* If any thread is blocked on some internal breakpoint, and we
7210 simply need to step over that breakpoint to get it going
7211 again, do that first. */
7213 /* However, if we see an event for the stepping thread, then we
7214 know all other threads have been moved past their breakpoints
7215 already. Let the caller check whether the step is finished,
7216 etc., before deciding to move it past a breakpoint. */
7217 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7220 /* Check if the current thread is blocked on an incomplete
7221 step-over, interrupted by a random signal. */
7222 if (ecs
->event_thread
->control
.trap_expected
7223 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7227 fprintf_unfiltered (gdb_stdlog
,
7228 "infrun: need to finish step-over of [%s]\n",
7229 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7235 /* Check if the current thread is blocked by a single-step
7236 breakpoint of another thread. */
7237 if (ecs
->hit_singlestep_breakpoint
)
7241 fprintf_unfiltered (gdb_stdlog
,
7242 "infrun: need to step [%s] over single-step "
7244 target_pid_to_str (ecs
->ptid
).c_str ());
7250 /* If this thread needs yet another step-over (e.g., stepping
7251 through a delay slot), do it first before moving on to
7253 if (thread_still_needs_step_over (ecs
->event_thread
))
7257 fprintf_unfiltered (gdb_stdlog
,
7258 "infrun: thread [%s] still needs step-over\n",
7259 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7265 /* If scheduler locking applies even if not stepping, there's no
7266 need to walk over threads. Above we've checked whether the
7267 current thread is stepping. If some other thread not the
7268 event thread is stepping, then it must be that scheduler
7269 locking is not in effect. */
7270 if (schedlock_applies (ecs
->event_thread
))
7273 /* Otherwise, we no longer expect a trap in the current thread.
7274 Clear the trap_expected flag before switching back -- this is
7275 what keep_going does as well, if we call it. */
7276 ecs
->event_thread
->control
.trap_expected
= 0;
7278 /* Likewise, clear the signal if it should not be passed. */
7279 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7280 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7282 /* Do all pending step-overs before actually proceeding with
7284 if (start_step_over ())
7286 prepare_to_wait (ecs
);
7290 /* Look for the stepping/nexting thread. */
7291 stepping_thread
= NULL
;
7293 for (thread_info
*tp
: all_non_exited_threads ())
7295 switch_to_thread_no_regs (tp
);
7297 /* Ignore threads of processes the caller is not
7300 && (tp
->inf
->process_target () != ecs
->target
7301 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7304 /* When stepping over a breakpoint, we lock all threads
7305 except the one that needs to move past the breakpoint.
7306 If a non-event thread has this set, the "incomplete
7307 step-over" check above should have caught it earlier. */
7308 if (tp
->control
.trap_expected
)
7310 internal_error (__FILE__
, __LINE__
,
7311 "[%s] has inconsistent state: "
7312 "trap_expected=%d\n",
7313 target_pid_to_str (tp
->ptid
).c_str (),
7314 tp
->control
.trap_expected
);
7317 /* Did we find the stepping thread? */
7318 if (tp
->control
.step_range_end
)
7320 /* Yep. There should only one though. */
7321 gdb_assert (stepping_thread
== NULL
);
7323 /* The event thread is handled at the top, before we
7325 gdb_assert (tp
!= ecs
->event_thread
);
7327 /* If some thread other than the event thread is
7328 stepping, then scheduler locking can't be in effect,
7329 otherwise we wouldn't have resumed the current event
7330 thread in the first place. */
7331 gdb_assert (!schedlock_applies (tp
));
7333 stepping_thread
= tp
;
7337 if (stepping_thread
!= NULL
)
7340 fprintf_unfiltered (gdb_stdlog
,
7341 "infrun: switching back to stepped thread\n");
7343 if (keep_going_stepped_thread (stepping_thread
))
7345 prepare_to_wait (ecs
);
7350 switch_to_thread (ecs
->event_thread
);
7356 /* Set a previously stepped thread back to stepping. Returns true on
7357 success, false if the resume is not possible (e.g., the thread
7361 keep_going_stepped_thread (struct thread_info
*tp
)
7363 struct frame_info
*frame
;
7364 struct execution_control_state ecss
;
7365 struct execution_control_state
*ecs
= &ecss
;
7367 /* If the stepping thread exited, then don't try to switch back and
7368 resume it, which could fail in several different ways depending
7369 on the target. Instead, just keep going.
7371 We can find a stepping dead thread in the thread list in two
7374 - The target supports thread exit events, and when the target
7375 tries to delete the thread from the thread list, inferior_ptid
7376 pointed at the exiting thread. In such case, calling
7377 delete_thread does not really remove the thread from the list;
7378 instead, the thread is left listed, with 'exited' state.
7380 - The target's debug interface does not support thread exit
7381 events, and so we have no idea whatsoever if the previously
7382 stepping thread is still alive. For that reason, we need to
7383 synchronously query the target now. */
7385 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7388 fprintf_unfiltered (gdb_stdlog
,
7389 "infrun: not resuming previously "
7390 "stepped thread, it has vanished\n");
7397 fprintf_unfiltered (gdb_stdlog
,
7398 "infrun: resuming previously stepped thread\n");
7400 reset_ecs (ecs
, tp
);
7401 switch_to_thread (tp
);
7403 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7404 frame
= get_current_frame ();
7406 /* If the PC of the thread we were trying to single-step has
7407 changed, then that thread has trapped or been signaled, but the
7408 event has not been reported to GDB yet. Re-poll the target
7409 looking for this particular thread's event (i.e. temporarily
7410 enable schedlock) by:
7412 - setting a break at the current PC
7413 - resuming that particular thread, only (by setting trap
7416 This prevents us continuously moving the single-step breakpoint
7417 forward, one instruction at a time, overstepping. */
7419 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7424 fprintf_unfiltered (gdb_stdlog
,
7425 "infrun: expected thread advanced also (%s -> %s)\n",
7426 paddress (target_gdbarch (), tp
->prev_pc
),
7427 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7429 /* Clear the info of the previous step-over, as it's no longer
7430 valid (if the thread was trying to step over a breakpoint, it
7431 has already succeeded). It's what keep_going would do too,
7432 if we called it. Do this before trying to insert the sss
7433 breakpoint, otherwise if we were previously trying to step
7434 over this exact address in another thread, the breakpoint is
7436 clear_step_over_info ();
7437 tp
->control
.trap_expected
= 0;
7439 insert_single_step_breakpoint (get_frame_arch (frame
),
7440 get_frame_address_space (frame
),
7441 tp
->suspend
.stop_pc
);
7444 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7445 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7450 fprintf_unfiltered (gdb_stdlog
,
7451 "infrun: expected thread still hasn't advanced\n");
7453 keep_going_pass_signal (ecs
);
7458 /* Is thread TP in the middle of (software or hardware)
7459 single-stepping? (Note the result of this function must never be
7460 passed directly as target_resume's STEP parameter.) */
7463 currently_stepping (struct thread_info
*tp
)
7465 return ((tp
->control
.step_range_end
7466 && tp
->control
.step_resume_breakpoint
== NULL
)
7467 || tp
->control
.trap_expected
7468 || tp
->stepped_breakpoint
7469 || bpstat_should_step ());
7472 /* Inferior has stepped into a subroutine call with source code that
7473 we should not step over. Do step to the first line of code in
7477 handle_step_into_function (struct gdbarch
*gdbarch
,
7478 struct execution_control_state
*ecs
)
7480 fill_in_stop_func (gdbarch
, ecs
);
7482 compunit_symtab
*cust
7483 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7484 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7485 ecs
->stop_func_start
7486 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7488 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7489 /* Use the step_resume_break to step until the end of the prologue,
7490 even if that involves jumps (as it seems to on the vax under
7492 /* If the prologue ends in the middle of a source line, continue to
7493 the end of that source line (if it is still within the function).
7494 Otherwise, just go to end of prologue. */
7495 if (stop_func_sal
.end
7496 && stop_func_sal
.pc
!= ecs
->stop_func_start
7497 && stop_func_sal
.end
< ecs
->stop_func_end
)
7498 ecs
->stop_func_start
= stop_func_sal
.end
;
7500 /* Architectures which require breakpoint adjustment might not be able
7501 to place a breakpoint at the computed address. If so, the test
7502 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7503 ecs->stop_func_start to an address at which a breakpoint may be
7504 legitimately placed.
7506 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7507 made, GDB will enter an infinite loop when stepping through
7508 optimized code consisting of VLIW instructions which contain
7509 subinstructions corresponding to different source lines. On
7510 FR-V, it's not permitted to place a breakpoint on any but the
7511 first subinstruction of a VLIW instruction. When a breakpoint is
7512 set, GDB will adjust the breakpoint address to the beginning of
7513 the VLIW instruction. Thus, we need to make the corresponding
7514 adjustment here when computing the stop address. */
7516 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7518 ecs
->stop_func_start
7519 = gdbarch_adjust_breakpoint_address (gdbarch
,
7520 ecs
->stop_func_start
);
7523 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7525 /* We are already there: stop now. */
7526 end_stepping_range (ecs
);
7531 /* Put the step-breakpoint there and go until there. */
7532 symtab_and_line sr_sal
;
7533 sr_sal
.pc
= ecs
->stop_func_start
;
7534 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7535 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7537 /* Do not specify what the fp should be when we stop since on
7538 some machines the prologue is where the new fp value is
7540 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7542 /* And make sure stepping stops right away then. */
7543 ecs
->event_thread
->control
.step_range_end
7544 = ecs
->event_thread
->control
.step_range_start
;
7549 /* Inferior has stepped backward into a subroutine call with source
7550 code that we should not step over. Do step to the beginning of the
7551 last line of code in it. */
7554 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7555 struct execution_control_state
*ecs
)
7557 struct compunit_symtab
*cust
;
7558 struct symtab_and_line stop_func_sal
;
7560 fill_in_stop_func (gdbarch
, ecs
);
7562 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7563 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7564 ecs
->stop_func_start
7565 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7567 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7569 /* OK, we're just going to keep stepping here. */
7570 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7572 /* We're there already. Just stop stepping now. */
7573 end_stepping_range (ecs
);
7577 /* Else just reset the step range and keep going.
7578 No step-resume breakpoint, they don't work for
7579 epilogues, which can have multiple entry paths. */
7580 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7581 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7587 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7588 This is used to both functions and to skip over code. */
7591 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7592 struct symtab_and_line sr_sal
,
7593 struct frame_id sr_id
,
7594 enum bptype sr_type
)
7596 /* There should never be more than one step-resume or longjmp-resume
7597 breakpoint per thread, so we should never be setting a new
7598 step_resume_breakpoint when one is already active. */
7599 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7600 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7603 fprintf_unfiltered (gdb_stdlog
,
7604 "infrun: inserting step-resume breakpoint at %s\n",
7605 paddress (gdbarch
, sr_sal
.pc
));
7607 inferior_thread ()->control
.step_resume_breakpoint
7608 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7612 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7613 struct symtab_and_line sr_sal
,
7614 struct frame_id sr_id
)
7616 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7621 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7622 This is used to skip a potential signal handler.
7624 This is called with the interrupted function's frame. The signal
7625 handler, when it returns, will resume the interrupted function at
7629 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7631 gdb_assert (return_frame
!= NULL
);
7633 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7635 symtab_and_line sr_sal
;
7636 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7637 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7638 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7640 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7641 get_stack_frame_id (return_frame
),
7645 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7646 is used to skip a function after stepping into it (for "next" or if
7647 the called function has no debugging information).
7649 The current function has almost always been reached by single
7650 stepping a call or return instruction. NEXT_FRAME belongs to the
7651 current function, and the breakpoint will be set at the caller's
7654 This is a separate function rather than reusing
7655 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7656 get_prev_frame, which may stop prematurely (see the implementation
7657 of frame_unwind_caller_id for an example). */
7660 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7662 /* We shouldn't have gotten here if we don't know where the call site
7664 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7666 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7668 symtab_and_line sr_sal
;
7669 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7670 frame_unwind_caller_pc (next_frame
));
7671 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7672 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7674 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7675 frame_unwind_caller_id (next_frame
));
7678 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7679 new breakpoint at the target of a jmp_buf. The handling of
7680 longjmp-resume uses the same mechanisms used for handling
7681 "step-resume" breakpoints. */
7684 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7686 /* There should never be more than one longjmp-resume breakpoint per
7687 thread, so we should never be setting a new
7688 longjmp_resume_breakpoint when one is already active. */
7689 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7692 fprintf_unfiltered (gdb_stdlog
,
7693 "infrun: inserting longjmp-resume breakpoint at %s\n",
7694 paddress (gdbarch
, pc
));
7696 inferior_thread ()->control
.exception_resume_breakpoint
=
7697 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7700 /* Insert an exception resume breakpoint. TP is the thread throwing
7701 the exception. The block B is the block of the unwinder debug hook
7702 function. FRAME is the frame corresponding to the call to this
7703 function. SYM is the symbol of the function argument holding the
7704 target PC of the exception. */
7707 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7708 const struct block
*b
,
7709 struct frame_info
*frame
,
7714 struct block_symbol vsym
;
7715 struct value
*value
;
7717 struct breakpoint
*bp
;
7719 vsym
= lookup_symbol_search_name (sym
->search_name (),
7721 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7722 /* If the value was optimized out, revert to the old behavior. */
7723 if (! value_optimized_out (value
))
7725 handler
= value_as_address (value
);
7728 fprintf_unfiltered (gdb_stdlog
,
7729 "infrun: exception resume at %lx\n",
7730 (unsigned long) handler
);
7732 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7734 bp_exception_resume
).release ();
7736 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7739 bp
->thread
= tp
->global_num
;
7740 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7743 catch (const gdb_exception_error
&e
)
7745 /* We want to ignore errors here. */
7749 /* A helper for check_exception_resume that sets an
7750 exception-breakpoint based on a SystemTap probe. */
7753 insert_exception_resume_from_probe (struct thread_info
*tp
,
7754 const struct bound_probe
*probe
,
7755 struct frame_info
*frame
)
7757 struct value
*arg_value
;
7759 struct breakpoint
*bp
;
7761 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7765 handler
= value_as_address (arg_value
);
7768 fprintf_unfiltered (gdb_stdlog
,
7769 "infrun: exception resume at %s\n",
7770 paddress (get_objfile_arch (probe
->objfile
),
7773 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7774 handler
, bp_exception_resume
).release ();
7775 bp
->thread
= tp
->global_num
;
7776 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7779 /* This is called when an exception has been intercepted. Check to
7780 see whether the exception's destination is of interest, and if so,
7781 set an exception resume breakpoint there. */
7784 check_exception_resume (struct execution_control_state
*ecs
,
7785 struct frame_info
*frame
)
7787 struct bound_probe probe
;
7788 struct symbol
*func
;
7790 /* First see if this exception unwinding breakpoint was set via a
7791 SystemTap probe point. If so, the probe has two arguments: the
7792 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7793 set a breakpoint there. */
7794 probe
= find_probe_by_pc (get_frame_pc (frame
));
7797 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7801 func
= get_frame_function (frame
);
7807 const struct block
*b
;
7808 struct block_iterator iter
;
7812 /* The exception breakpoint is a thread-specific breakpoint on
7813 the unwinder's debug hook, declared as:
7815 void _Unwind_DebugHook (void *cfa, void *handler);
7817 The CFA argument indicates the frame to which control is
7818 about to be transferred. HANDLER is the destination PC.
7820 We ignore the CFA and set a temporary breakpoint at HANDLER.
7821 This is not extremely efficient but it avoids issues in gdb
7822 with computing the DWARF CFA, and it also works even in weird
7823 cases such as throwing an exception from inside a signal
7826 b
= SYMBOL_BLOCK_VALUE (func
);
7827 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7829 if (!SYMBOL_IS_ARGUMENT (sym
))
7836 insert_exception_resume_breakpoint (ecs
->event_thread
,
7842 catch (const gdb_exception_error
&e
)
7848 stop_waiting (struct execution_control_state
*ecs
)
7851 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7853 /* Let callers know we don't want to wait for the inferior anymore. */
7854 ecs
->wait_some_more
= 0;
7856 /* If all-stop, but the target is always in non-stop mode, stop all
7857 threads now that we're presenting the stop to the user. */
7858 if (!non_stop
&& target_is_non_stop_p ())
7859 stop_all_threads ();
7862 /* Like keep_going, but passes the signal to the inferior, even if the
7863 signal is set to nopass. */
7866 keep_going_pass_signal (struct execution_control_state
*ecs
)
7868 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7869 gdb_assert (!ecs
->event_thread
->resumed
);
7871 /* Save the pc before execution, to compare with pc after stop. */
7872 ecs
->event_thread
->prev_pc
7873 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7875 if (ecs
->event_thread
->control
.trap_expected
)
7877 struct thread_info
*tp
= ecs
->event_thread
;
7880 fprintf_unfiltered (gdb_stdlog
,
7881 "infrun: %s has trap_expected set, "
7882 "resuming to collect trap\n",
7883 target_pid_to_str (tp
->ptid
).c_str ());
7885 /* We haven't yet gotten our trap, and either: intercepted a
7886 non-signal event (e.g., a fork); or took a signal which we
7887 are supposed to pass through to the inferior. Simply
7889 resume (ecs
->event_thread
->suspend
.stop_signal
);
7891 else if (step_over_info_valid_p ())
7893 /* Another thread is stepping over a breakpoint in-line. If
7894 this thread needs a step-over too, queue the request. In
7895 either case, this resume must be deferred for later. */
7896 struct thread_info
*tp
= ecs
->event_thread
;
7898 if (ecs
->hit_singlestep_breakpoint
7899 || thread_still_needs_step_over (tp
))
7902 fprintf_unfiltered (gdb_stdlog
,
7903 "infrun: step-over already in progress: "
7904 "step-over for %s deferred\n",
7905 target_pid_to_str (tp
->ptid
).c_str ());
7906 thread_step_over_chain_enqueue (tp
);
7911 fprintf_unfiltered (gdb_stdlog
,
7912 "infrun: step-over in progress: "
7913 "resume of %s deferred\n",
7914 target_pid_to_str (tp
->ptid
).c_str ());
7919 struct regcache
*regcache
= get_current_regcache ();
7922 step_over_what step_what
;
7924 /* Either the trap was not expected, but we are continuing
7925 anyway (if we got a signal, the user asked it be passed to
7928 We got our expected trap, but decided we should resume from
7931 We're going to run this baby now!
7933 Note that insert_breakpoints won't try to re-insert
7934 already inserted breakpoints. Therefore, we don't
7935 care if breakpoints were already inserted, or not. */
7937 /* If we need to step over a breakpoint, and we're not using
7938 displaced stepping to do so, insert all breakpoints
7939 (watchpoints, etc.) but the one we're stepping over, step one
7940 instruction, and then re-insert the breakpoint when that step
7943 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7945 remove_bp
= (ecs
->hit_singlestep_breakpoint
7946 || (step_what
& STEP_OVER_BREAKPOINT
));
7947 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7949 /* We can't use displaced stepping if we need to step past a
7950 watchpoint. The instruction copied to the scratch pad would
7951 still trigger the watchpoint. */
7953 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7955 set_step_over_info (regcache
->aspace (),
7956 regcache_read_pc (regcache
), remove_wps
,
7957 ecs
->event_thread
->global_num
);
7959 else if (remove_wps
)
7960 set_step_over_info (NULL
, 0, remove_wps
, -1);
7962 /* If we now need to do an in-line step-over, we need to stop
7963 all other threads. Note this must be done before
7964 insert_breakpoints below, because that removes the breakpoint
7965 we're about to step over, otherwise other threads could miss
7967 if (step_over_info_valid_p () && target_is_non_stop_p ())
7968 stop_all_threads ();
7970 /* Stop stepping if inserting breakpoints fails. */
7973 insert_breakpoints ();
7975 catch (const gdb_exception_error
&e
)
7977 exception_print (gdb_stderr
, e
);
7979 clear_step_over_info ();
7983 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7985 resume (ecs
->event_thread
->suspend
.stop_signal
);
7988 prepare_to_wait (ecs
);
7991 /* Called when we should continue running the inferior, because the
7992 current event doesn't cause a user visible stop. This does the
7993 resuming part; waiting for the next event is done elsewhere. */
7996 keep_going (struct execution_control_state
*ecs
)
7998 if (ecs
->event_thread
->control
.trap_expected
7999 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8000 ecs
->event_thread
->control
.trap_expected
= 0;
8002 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8003 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8004 keep_going_pass_signal (ecs
);
8007 /* This function normally comes after a resume, before
8008 handle_inferior_event exits. It takes care of any last bits of
8009 housekeeping, and sets the all-important wait_some_more flag. */
8012 prepare_to_wait (struct execution_control_state
*ecs
)
8015 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
8017 ecs
->wait_some_more
= 1;
8019 if (!target_is_async_p ())
8020 mark_infrun_async_event_handler ();
8023 /* We are done with the step range of a step/next/si/ni command.
8024 Called once for each n of a "step n" operation. */
8027 end_stepping_range (struct execution_control_state
*ecs
)
8029 ecs
->event_thread
->control
.stop_step
= 1;
8033 /* Several print_*_reason functions to print why the inferior has stopped.
8034 We always print something when the inferior exits, or receives a signal.
8035 The rest of the cases are dealt with later on in normal_stop and
8036 print_it_typical. Ideally there should be a call to one of these
8037 print_*_reason functions functions from handle_inferior_event each time
8038 stop_waiting is called.
8040 Note that we don't call these directly, instead we delegate that to
8041 the interpreters, through observers. Interpreters then call these
8042 with whatever uiout is right. */
8045 print_end_stepping_range_reason (struct ui_out
*uiout
)
8047 /* For CLI-like interpreters, print nothing. */
8049 if (uiout
->is_mi_like_p ())
8051 uiout
->field_string ("reason",
8052 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8057 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8059 annotate_signalled ();
8060 if (uiout
->is_mi_like_p ())
8062 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8063 uiout
->text ("\nProgram terminated with signal ");
8064 annotate_signal_name ();
8065 uiout
->field_string ("signal-name",
8066 gdb_signal_to_name (siggnal
));
8067 annotate_signal_name_end ();
8069 annotate_signal_string ();
8070 uiout
->field_string ("signal-meaning",
8071 gdb_signal_to_string (siggnal
));
8072 annotate_signal_string_end ();
8073 uiout
->text (".\n");
8074 uiout
->text ("The program no longer exists.\n");
8078 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8080 struct inferior
*inf
= current_inferior ();
8081 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8083 annotate_exited (exitstatus
);
8086 if (uiout
->is_mi_like_p ())
8087 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8088 std::string exit_code_str
8089 = string_printf ("0%o", (unsigned int) exitstatus
);
8090 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8091 plongest (inf
->num
), pidstr
.c_str (),
8092 string_field ("exit-code", exit_code_str
.c_str ()));
8096 if (uiout
->is_mi_like_p ())
8098 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8099 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8100 plongest (inf
->num
), pidstr
.c_str ());
8104 /* Some targets/architectures can do extra processing/display of
8105 segmentation faults. E.g., Intel MPX boundary faults.
8106 Call the architecture dependent function to handle the fault. */
8109 handle_segmentation_fault (struct ui_out
*uiout
)
8111 struct regcache
*regcache
= get_current_regcache ();
8112 struct gdbarch
*gdbarch
= regcache
->arch ();
8114 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8115 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8119 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8121 struct thread_info
*thr
= inferior_thread ();
8125 if (uiout
->is_mi_like_p ())
8127 else if (show_thread_that_caused_stop ())
8131 uiout
->text ("\nThread ");
8132 uiout
->field_string ("thread-id", print_thread_id (thr
));
8134 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8137 uiout
->text (" \"");
8138 uiout
->field_string ("name", name
);
8143 uiout
->text ("\nProgram");
8145 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8146 uiout
->text (" stopped");
8149 uiout
->text (" received signal ");
8150 annotate_signal_name ();
8151 if (uiout
->is_mi_like_p ())
8153 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8154 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8155 annotate_signal_name_end ();
8157 annotate_signal_string ();
8158 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8160 if (siggnal
== GDB_SIGNAL_SEGV
)
8161 handle_segmentation_fault (uiout
);
8163 annotate_signal_string_end ();
8165 uiout
->text (".\n");
8169 print_no_history_reason (struct ui_out
*uiout
)
8171 uiout
->text ("\nNo more reverse-execution history.\n");
8174 /* Print current location without a level number, if we have changed
8175 functions or hit a breakpoint. Print source line if we have one.
8176 bpstat_print contains the logic deciding in detail what to print,
8177 based on the event(s) that just occurred. */
8180 print_stop_location (struct target_waitstatus
*ws
)
8183 enum print_what source_flag
;
8184 int do_frame_printing
= 1;
8185 struct thread_info
*tp
= inferior_thread ();
8187 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8191 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8192 should) carry around the function and does (or should) use
8193 that when doing a frame comparison. */
8194 if (tp
->control
.stop_step
8195 && frame_id_eq (tp
->control
.step_frame_id
,
8196 get_frame_id (get_current_frame ()))
8197 && (tp
->control
.step_start_function
8198 == find_pc_function (tp
->suspend
.stop_pc
)))
8200 /* Finished step, just print source line. */
8201 source_flag
= SRC_LINE
;
8205 /* Print location and source line. */
8206 source_flag
= SRC_AND_LOC
;
8209 case PRINT_SRC_AND_LOC
:
8210 /* Print location and source line. */
8211 source_flag
= SRC_AND_LOC
;
8213 case PRINT_SRC_ONLY
:
8214 source_flag
= SRC_LINE
;
8217 /* Something bogus. */
8218 source_flag
= SRC_LINE
;
8219 do_frame_printing
= 0;
8222 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8225 /* The behavior of this routine with respect to the source
8227 SRC_LINE: Print only source line
8228 LOCATION: Print only location
8229 SRC_AND_LOC: Print location and source line. */
8230 if (do_frame_printing
)
8231 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8237 print_stop_event (struct ui_out
*uiout
, bool displays
)
8239 struct target_waitstatus last
;
8240 struct thread_info
*tp
;
8242 get_last_target_status (nullptr, nullptr, &last
);
8245 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8247 print_stop_location (&last
);
8249 /* Display the auto-display expressions. */
8254 tp
= inferior_thread ();
8255 if (tp
->thread_fsm
!= NULL
8256 && tp
->thread_fsm
->finished_p ())
8258 struct return_value_info
*rv
;
8260 rv
= tp
->thread_fsm
->return_value ();
8262 print_return_value (uiout
, rv
);
8269 maybe_remove_breakpoints (void)
8271 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8273 if (remove_breakpoints ())
8275 target_terminal::ours_for_output ();
8276 printf_filtered (_("Cannot remove breakpoints because "
8277 "program is no longer writable.\nFurther "
8278 "execution is probably impossible.\n"));
8283 /* The execution context that just caused a normal stop. */
8290 DISABLE_COPY_AND_ASSIGN (stop_context
);
8292 bool changed () const;
8297 /* The event PTID. */
8301 /* If stopp for a thread event, this is the thread that caused the
8303 struct thread_info
*thread
;
8305 /* The inferior that caused the stop. */
8309 /* Initializes a new stop context. If stopped for a thread event, this
8310 takes a strong reference to the thread. */
8312 stop_context::stop_context ()
8314 stop_id
= get_stop_id ();
8315 ptid
= inferior_ptid
;
8316 inf_num
= current_inferior ()->num
;
8318 if (inferior_ptid
!= null_ptid
)
8320 /* Take a strong reference so that the thread can't be deleted
8322 thread
= inferior_thread ();
8329 /* Release a stop context previously created with save_stop_context.
8330 Releases the strong reference to the thread as well. */
8332 stop_context::~stop_context ()
8338 /* Return true if the current context no longer matches the saved stop
8342 stop_context::changed () const
8344 if (ptid
!= inferior_ptid
)
8346 if (inf_num
!= current_inferior ()->num
)
8348 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8350 if (get_stop_id () != stop_id
)
8360 struct target_waitstatus last
;
8362 get_last_target_status (nullptr, nullptr, &last
);
8366 /* If an exception is thrown from this point on, make sure to
8367 propagate GDB's knowledge of the executing state to the
8368 frontend/user running state. A QUIT is an easy exception to see
8369 here, so do this before any filtered output. */
8371 ptid_t finish_ptid
= null_ptid
;
8374 finish_ptid
= minus_one_ptid
;
8375 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8376 || last
.kind
== TARGET_WAITKIND_EXITED
)
8378 /* On some targets, we may still have live threads in the
8379 inferior when we get a process exit event. E.g., for
8380 "checkpoint", when the current checkpoint/fork exits,
8381 linux-fork.c automatically switches to another fork from
8382 within target_mourn_inferior. */
8383 if (inferior_ptid
!= null_ptid
)
8384 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8386 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8387 finish_ptid
= inferior_ptid
;
8389 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8390 if (finish_ptid
!= null_ptid
)
8392 maybe_finish_thread_state
.emplace
8393 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8396 /* As we're presenting a stop, and potentially removing breakpoints,
8397 update the thread list so we can tell whether there are threads
8398 running on the target. With target remote, for example, we can
8399 only learn about new threads when we explicitly update the thread
8400 list. Do this before notifying the interpreters about signal
8401 stops, end of stepping ranges, etc., so that the "new thread"
8402 output is emitted before e.g., "Program received signal FOO",
8403 instead of after. */
8404 update_thread_list ();
8406 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8407 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8409 /* As with the notification of thread events, we want to delay
8410 notifying the user that we've switched thread context until
8411 the inferior actually stops.
8413 There's no point in saying anything if the inferior has exited.
8414 Note that SIGNALLED here means "exited with a signal", not
8415 "received a signal".
8417 Also skip saying anything in non-stop mode. In that mode, as we
8418 don't want GDB to switch threads behind the user's back, to avoid
8419 races where the user is typing a command to apply to thread x,
8420 but GDB switches to thread y before the user finishes entering
8421 the command, fetch_inferior_event installs a cleanup to restore
8422 the current thread back to the thread the user had selected right
8423 after this event is handled, so we're not really switching, only
8424 informing of a stop. */
8426 && previous_inferior_ptid
!= inferior_ptid
8427 && target_has_execution
8428 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8429 && last
.kind
!= TARGET_WAITKIND_EXITED
8430 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8432 SWITCH_THRU_ALL_UIS ()
8434 target_terminal::ours_for_output ();
8435 printf_filtered (_("[Switching to %s]\n"),
8436 target_pid_to_str (inferior_ptid
).c_str ());
8437 annotate_thread_changed ();
8439 previous_inferior_ptid
= inferior_ptid
;
8442 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8444 SWITCH_THRU_ALL_UIS ()
8445 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8447 target_terminal::ours_for_output ();
8448 printf_filtered (_("No unwaited-for children left.\n"));
8452 /* Note: this depends on the update_thread_list call above. */
8453 maybe_remove_breakpoints ();
8455 /* If an auto-display called a function and that got a signal,
8456 delete that auto-display to avoid an infinite recursion. */
8458 if (stopped_by_random_signal
)
8459 disable_current_display ();
8461 SWITCH_THRU_ALL_UIS ()
8463 async_enable_stdin ();
8466 /* Let the user/frontend see the threads as stopped. */
8467 maybe_finish_thread_state
.reset ();
8469 /* Select innermost stack frame - i.e., current frame is frame 0,
8470 and current location is based on that. Handle the case where the
8471 dummy call is returning after being stopped. E.g. the dummy call
8472 previously hit a breakpoint. (If the dummy call returns
8473 normally, we won't reach here.) Do this before the stop hook is
8474 run, so that it doesn't get to see the temporary dummy frame,
8475 which is not where we'll present the stop. */
8476 if (has_stack_frames ())
8478 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8480 /* Pop the empty frame that contains the stack dummy. This
8481 also restores inferior state prior to the call (struct
8482 infcall_suspend_state). */
8483 struct frame_info
*frame
= get_current_frame ();
8485 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8487 /* frame_pop calls reinit_frame_cache as the last thing it
8488 does which means there's now no selected frame. */
8491 select_frame (get_current_frame ());
8493 /* Set the current source location. */
8494 set_current_sal_from_frame (get_current_frame ());
8497 /* Look up the hook_stop and run it (CLI internally handles problem
8498 of stop_command's pre-hook not existing). */
8499 if (stop_command
!= NULL
)
8501 stop_context saved_context
;
8505 execute_cmd_pre_hook (stop_command
);
8507 catch (const gdb_exception
&ex
)
8509 exception_fprintf (gdb_stderr
, ex
,
8510 "Error while running hook_stop:\n");
8513 /* If the stop hook resumes the target, then there's no point in
8514 trying to notify about the previous stop; its context is
8515 gone. Likewise if the command switches thread or inferior --
8516 the observers would print a stop for the wrong
8518 if (saved_context
.changed ())
8522 /* Notify observers about the stop. This is where the interpreters
8523 print the stop event. */
8524 if (inferior_ptid
!= null_ptid
)
8525 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8528 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8530 annotate_stopped ();
8532 if (target_has_execution
)
8534 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8535 && last
.kind
!= TARGET_WAITKIND_EXITED
8536 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8537 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8538 Delete any breakpoint that is to be deleted at the next stop. */
8539 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8542 /* Try to get rid of automatically added inferiors that are no
8543 longer needed. Keeping those around slows down things linearly.
8544 Note that this never removes the current inferior. */
8551 signal_stop_state (int signo
)
8553 return signal_stop
[signo
];
8557 signal_print_state (int signo
)
8559 return signal_print
[signo
];
8563 signal_pass_state (int signo
)
8565 return signal_program
[signo
];
8569 signal_cache_update (int signo
)
8573 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8574 signal_cache_update (signo
);
8579 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8580 && signal_print
[signo
] == 0
8581 && signal_program
[signo
] == 1
8582 && signal_catch
[signo
] == 0);
8586 signal_stop_update (int signo
, int state
)
8588 int ret
= signal_stop
[signo
];
8590 signal_stop
[signo
] = state
;
8591 signal_cache_update (signo
);
8596 signal_print_update (int signo
, int state
)
8598 int ret
= signal_print
[signo
];
8600 signal_print
[signo
] = state
;
8601 signal_cache_update (signo
);
8606 signal_pass_update (int signo
, int state
)
8608 int ret
= signal_program
[signo
];
8610 signal_program
[signo
] = state
;
8611 signal_cache_update (signo
);
8615 /* Update the global 'signal_catch' from INFO and notify the
8619 signal_catch_update (const unsigned int *info
)
8623 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8624 signal_catch
[i
] = info
[i
] > 0;
8625 signal_cache_update (-1);
8626 target_pass_signals (signal_pass
);
8630 sig_print_header (void)
8632 printf_filtered (_("Signal Stop\tPrint\tPass "
8633 "to program\tDescription\n"));
8637 sig_print_info (enum gdb_signal oursig
)
8639 const char *name
= gdb_signal_to_name (oursig
);
8640 int name_padding
= 13 - strlen (name
);
8642 if (name_padding
<= 0)
8645 printf_filtered ("%s", name
);
8646 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8647 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8648 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8649 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8650 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8653 /* Specify how various signals in the inferior should be handled. */
8656 handle_command (const char *args
, int from_tty
)
8658 int digits
, wordlen
;
8659 int sigfirst
, siglast
;
8660 enum gdb_signal oursig
;
8665 error_no_arg (_("signal to handle"));
8668 /* Allocate and zero an array of flags for which signals to handle. */
8670 const size_t nsigs
= GDB_SIGNAL_LAST
;
8671 unsigned char sigs
[nsigs
] {};
8673 /* Break the command line up into args. */
8675 gdb_argv
built_argv (args
);
8677 /* Walk through the args, looking for signal oursigs, signal names, and
8678 actions. Signal numbers and signal names may be interspersed with
8679 actions, with the actions being performed for all signals cumulatively
8680 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8682 for (char *arg
: built_argv
)
8684 wordlen
= strlen (arg
);
8685 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8689 sigfirst
= siglast
= -1;
8691 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8693 /* Apply action to all signals except those used by the
8694 debugger. Silently skip those. */
8697 siglast
= nsigs
- 1;
8699 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8701 SET_SIGS (nsigs
, sigs
, signal_stop
);
8702 SET_SIGS (nsigs
, sigs
, signal_print
);
8704 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8706 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8708 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8710 SET_SIGS (nsigs
, sigs
, signal_print
);
8712 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8714 SET_SIGS (nsigs
, sigs
, signal_program
);
8716 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8718 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8720 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8722 SET_SIGS (nsigs
, sigs
, signal_program
);
8724 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8726 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8727 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8729 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8731 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8733 else if (digits
> 0)
8735 /* It is numeric. The numeric signal refers to our own
8736 internal signal numbering from target.h, not to host/target
8737 signal number. This is a feature; users really should be
8738 using symbolic names anyway, and the common ones like
8739 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8741 sigfirst
= siglast
= (int)
8742 gdb_signal_from_command (atoi (arg
));
8743 if (arg
[digits
] == '-')
8746 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8748 if (sigfirst
> siglast
)
8750 /* Bet he didn't figure we'd think of this case... */
8751 std::swap (sigfirst
, siglast
);
8756 oursig
= gdb_signal_from_name (arg
);
8757 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8759 sigfirst
= siglast
= (int) oursig
;
8763 /* Not a number and not a recognized flag word => complain. */
8764 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8768 /* If any signal numbers or symbol names were found, set flags for
8769 which signals to apply actions to. */
8771 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8773 switch ((enum gdb_signal
) signum
)
8775 case GDB_SIGNAL_TRAP
:
8776 case GDB_SIGNAL_INT
:
8777 if (!allsigs
&& !sigs
[signum
])
8779 if (query (_("%s is used by the debugger.\n\
8780 Are you sure you want to change it? "),
8781 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8786 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8790 case GDB_SIGNAL_DEFAULT
:
8791 case GDB_SIGNAL_UNKNOWN
:
8792 /* Make sure that "all" doesn't print these. */
8801 for (int signum
= 0; signum
< nsigs
; signum
++)
8804 signal_cache_update (-1);
8805 target_pass_signals (signal_pass
);
8806 target_program_signals (signal_program
);
8810 /* Show the results. */
8811 sig_print_header ();
8812 for (; signum
< nsigs
; signum
++)
8814 sig_print_info ((enum gdb_signal
) signum
);
8821 /* Complete the "handle" command. */
8824 handle_completer (struct cmd_list_element
*ignore
,
8825 completion_tracker
&tracker
,
8826 const char *text
, const char *word
)
8828 static const char * const keywords
[] =
8842 signal_completer (ignore
, tracker
, text
, word
);
8843 complete_on_enum (tracker
, keywords
, word
, word
);
8847 gdb_signal_from_command (int num
)
8849 if (num
>= 1 && num
<= 15)
8850 return (enum gdb_signal
) num
;
8851 error (_("Only signals 1-15 are valid as numeric signals.\n\
8852 Use \"info signals\" for a list of symbolic signals."));
8855 /* Print current contents of the tables set by the handle command.
8856 It is possible we should just be printing signals actually used
8857 by the current target (but for things to work right when switching
8858 targets, all signals should be in the signal tables). */
8861 info_signals_command (const char *signum_exp
, int from_tty
)
8863 enum gdb_signal oursig
;
8865 sig_print_header ();
8869 /* First see if this is a symbol name. */
8870 oursig
= gdb_signal_from_name (signum_exp
);
8871 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8873 /* No, try numeric. */
8875 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8877 sig_print_info (oursig
);
8881 printf_filtered ("\n");
8882 /* These ugly casts brought to you by the native VAX compiler. */
8883 for (oursig
= GDB_SIGNAL_FIRST
;
8884 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8885 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8889 if (oursig
!= GDB_SIGNAL_UNKNOWN
8890 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8891 sig_print_info (oursig
);
8894 printf_filtered (_("\nUse the \"handle\" command "
8895 "to change these tables.\n"));
8898 /* The $_siginfo convenience variable is a bit special. We don't know
8899 for sure the type of the value until we actually have a chance to
8900 fetch the data. The type can change depending on gdbarch, so it is
8901 also dependent on which thread you have selected.
8903 1. making $_siginfo be an internalvar that creates a new value on
8906 2. making the value of $_siginfo be an lval_computed value. */
8908 /* This function implements the lval_computed support for reading a
8912 siginfo_value_read (struct value
*v
)
8914 LONGEST transferred
;
8916 /* If we can access registers, so can we access $_siginfo. Likewise
8918 validate_registers_access ();
8921 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8923 value_contents_all_raw (v
),
8925 TYPE_LENGTH (value_type (v
)));
8927 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8928 error (_("Unable to read siginfo"));
8931 /* This function implements the lval_computed support for writing a
8935 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8937 LONGEST transferred
;
8939 /* If we can access registers, so can we access $_siginfo. Likewise
8941 validate_registers_access ();
8943 transferred
= target_write (current_top_target (),
8944 TARGET_OBJECT_SIGNAL_INFO
,
8946 value_contents_all_raw (fromval
),
8948 TYPE_LENGTH (value_type (fromval
)));
8950 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8951 error (_("Unable to write siginfo"));
8954 static const struct lval_funcs siginfo_value_funcs
=
8960 /* Return a new value with the correct type for the siginfo object of
8961 the current thread using architecture GDBARCH. Return a void value
8962 if there's no object available. */
8964 static struct value
*
8965 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8968 if (target_has_stack
8969 && inferior_ptid
!= null_ptid
8970 && gdbarch_get_siginfo_type_p (gdbarch
))
8972 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8974 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8977 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8981 /* infcall_suspend_state contains state about the program itself like its
8982 registers and any signal it received when it last stopped.
8983 This state must be restored regardless of how the inferior function call
8984 ends (either successfully, or after it hits a breakpoint or signal)
8985 if the program is to properly continue where it left off. */
8987 class infcall_suspend_state
8990 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8991 once the inferior function call has finished. */
8992 infcall_suspend_state (struct gdbarch
*gdbarch
,
8993 const struct thread_info
*tp
,
8994 struct regcache
*regcache
)
8995 : m_thread_suspend (tp
->suspend
),
8996 m_registers (new readonly_detached_regcache (*regcache
))
8998 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9000 if (gdbarch_get_siginfo_type_p (gdbarch
))
9002 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9003 size_t len
= TYPE_LENGTH (type
);
9005 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9007 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9008 siginfo_data
.get (), 0, len
) != len
)
9010 /* Errors ignored. */
9011 siginfo_data
.reset (nullptr);
9017 m_siginfo_gdbarch
= gdbarch
;
9018 m_siginfo_data
= std::move (siginfo_data
);
9022 /* Return a pointer to the stored register state. */
9024 readonly_detached_regcache
*registers () const
9026 return m_registers
.get ();
9029 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9031 void restore (struct gdbarch
*gdbarch
,
9032 struct thread_info
*tp
,
9033 struct regcache
*regcache
) const
9035 tp
->suspend
= m_thread_suspend
;
9037 if (m_siginfo_gdbarch
== gdbarch
)
9039 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9041 /* Errors ignored. */
9042 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9043 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9046 /* The inferior can be gone if the user types "print exit(0)"
9047 (and perhaps other times). */
9048 if (target_has_execution
)
9049 /* NB: The register write goes through to the target. */
9050 regcache
->restore (registers ());
9054 /* How the current thread stopped before the inferior function call was
9056 struct thread_suspend_state m_thread_suspend
;
9058 /* The registers before the inferior function call was executed. */
9059 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9061 /* Format of SIGINFO_DATA or NULL if it is not present. */
9062 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9064 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9065 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9066 content would be invalid. */
9067 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9070 infcall_suspend_state_up
9071 save_infcall_suspend_state ()
9073 struct thread_info
*tp
= inferior_thread ();
9074 struct regcache
*regcache
= get_current_regcache ();
9075 struct gdbarch
*gdbarch
= regcache
->arch ();
9077 infcall_suspend_state_up inf_state
9078 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9080 /* Having saved the current state, adjust the thread state, discarding
9081 any stop signal information. The stop signal is not useful when
9082 starting an inferior function call, and run_inferior_call will not use
9083 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9084 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9089 /* Restore inferior session state to INF_STATE. */
9092 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9094 struct thread_info
*tp
= inferior_thread ();
9095 struct regcache
*regcache
= get_current_regcache ();
9096 struct gdbarch
*gdbarch
= regcache
->arch ();
9098 inf_state
->restore (gdbarch
, tp
, regcache
);
9099 discard_infcall_suspend_state (inf_state
);
9103 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9108 readonly_detached_regcache
*
9109 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9111 return inf_state
->registers ();
9114 /* infcall_control_state contains state regarding gdb's control of the
9115 inferior itself like stepping control. It also contains session state like
9116 the user's currently selected frame. */
9118 struct infcall_control_state
9120 struct thread_control_state thread_control
;
9121 struct inferior_control_state inferior_control
;
9124 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9125 int stopped_by_random_signal
= 0;
9127 /* ID if the selected frame when the inferior function call was made. */
9128 struct frame_id selected_frame_id
{};
9131 /* Save all of the information associated with the inferior<==>gdb
9134 infcall_control_state_up
9135 save_infcall_control_state ()
9137 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9138 struct thread_info
*tp
= inferior_thread ();
9139 struct inferior
*inf
= current_inferior ();
9141 inf_status
->thread_control
= tp
->control
;
9142 inf_status
->inferior_control
= inf
->control
;
9144 tp
->control
.step_resume_breakpoint
= NULL
;
9145 tp
->control
.exception_resume_breakpoint
= NULL
;
9147 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9148 chain. If caller's caller is walking the chain, they'll be happier if we
9149 hand them back the original chain when restore_infcall_control_state is
9151 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9154 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9155 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9157 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9163 restore_selected_frame (const frame_id
&fid
)
9165 frame_info
*frame
= frame_find_by_id (fid
);
9167 /* If inf_status->selected_frame_id is NULL, there was no previously
9171 warning (_("Unable to restore previously selected frame."));
9175 select_frame (frame
);
9178 /* Restore inferior session state to INF_STATUS. */
9181 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9183 struct thread_info
*tp
= inferior_thread ();
9184 struct inferior
*inf
= current_inferior ();
9186 if (tp
->control
.step_resume_breakpoint
)
9187 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9189 if (tp
->control
.exception_resume_breakpoint
)
9190 tp
->control
.exception_resume_breakpoint
->disposition
9191 = disp_del_at_next_stop
;
9193 /* Handle the bpstat_copy of the chain. */
9194 bpstat_clear (&tp
->control
.stop_bpstat
);
9196 tp
->control
= inf_status
->thread_control
;
9197 inf
->control
= inf_status
->inferior_control
;
9200 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9201 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9203 if (target_has_stack
)
9205 /* The point of the try/catch is that if the stack is clobbered,
9206 walking the stack might encounter a garbage pointer and
9207 error() trying to dereference it. */
9210 restore_selected_frame (inf_status
->selected_frame_id
);
9212 catch (const gdb_exception_error
&ex
)
9214 exception_fprintf (gdb_stderr
, ex
,
9215 "Unable to restore previously selected frame:\n");
9216 /* Error in restoring the selected frame. Select the
9218 select_frame (get_current_frame ());
9226 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9228 if (inf_status
->thread_control
.step_resume_breakpoint
)
9229 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9230 = disp_del_at_next_stop
;
9232 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9233 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9234 = disp_del_at_next_stop
;
9236 /* See save_infcall_control_state for info on stop_bpstat. */
9237 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9245 clear_exit_convenience_vars (void)
9247 clear_internalvar (lookup_internalvar ("_exitsignal"));
9248 clear_internalvar (lookup_internalvar ("_exitcode"));
9252 /* User interface for reverse debugging:
9253 Set exec-direction / show exec-direction commands
9254 (returns error unless target implements to_set_exec_direction method). */
9256 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9257 static const char exec_forward
[] = "forward";
9258 static const char exec_reverse
[] = "reverse";
9259 static const char *exec_direction
= exec_forward
;
9260 static const char *const exec_direction_names
[] = {
9267 set_exec_direction_func (const char *args
, int from_tty
,
9268 struct cmd_list_element
*cmd
)
9270 if (target_can_execute_reverse
)
9272 if (!strcmp (exec_direction
, exec_forward
))
9273 execution_direction
= EXEC_FORWARD
;
9274 else if (!strcmp (exec_direction
, exec_reverse
))
9275 execution_direction
= EXEC_REVERSE
;
9279 exec_direction
= exec_forward
;
9280 error (_("Target does not support this operation."));
9285 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9286 struct cmd_list_element
*cmd
, const char *value
)
9288 switch (execution_direction
) {
9290 fprintf_filtered (out
, _("Forward.\n"));
9293 fprintf_filtered (out
, _("Reverse.\n"));
9296 internal_error (__FILE__
, __LINE__
,
9297 _("bogus execution_direction value: %d"),
9298 (int) execution_direction
);
9303 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9304 struct cmd_list_element
*c
, const char *value
)
9306 fprintf_filtered (file
, _("Resuming the execution of threads "
9307 "of all processes is %s.\n"), value
);
9310 /* Implementation of `siginfo' variable. */
9312 static const struct internalvar_funcs siginfo_funcs
=
9319 /* Callback for infrun's target events source. This is marked when a
9320 thread has a pending status to process. */
9323 infrun_async_inferior_event_handler (gdb_client_data data
)
9325 inferior_event_handler (INF_REG_EVENT
, NULL
);
9329 _initialize_infrun (void)
9331 struct cmd_list_element
*c
;
9333 /* Register extra event sources in the event loop. */
9334 infrun_async_inferior_event_token
9335 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9337 add_info ("signals", info_signals_command
, _("\
9338 What debugger does when program gets various signals.\n\
9339 Specify a signal as argument to print info on that signal only."));
9340 add_info_alias ("handle", "signals", 0);
9342 c
= add_com ("handle", class_run
, handle_command
, _("\
9343 Specify how to handle signals.\n\
9344 Usage: handle SIGNAL [ACTIONS]\n\
9345 Args are signals and actions to apply to those signals.\n\
9346 If no actions are specified, the current settings for the specified signals\n\
9347 will be displayed instead.\n\
9349 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9350 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9351 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9352 The special arg \"all\" is recognized to mean all signals except those\n\
9353 used by the debugger, typically SIGTRAP and SIGINT.\n\
9355 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9356 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9357 Stop means reenter debugger if this signal happens (implies print).\n\
9358 Print means print a message if this signal happens.\n\
9359 Pass means let program see this signal; otherwise program doesn't know.\n\
9360 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9361 Pass and Stop may be combined.\n\
9363 Multiple signals may be specified. Signal numbers and signal names\n\
9364 may be interspersed with actions, with the actions being performed for\n\
9365 all signals cumulatively specified."));
9366 set_cmd_completer (c
, handle_completer
);
9369 stop_command
= add_cmd ("stop", class_obscure
,
9370 not_just_help_class_command
, _("\
9371 There is no `stop' command, but you can set a hook on `stop'.\n\
9372 This allows you to set a list of commands to be run each time execution\n\
9373 of the program stops."), &cmdlist
);
9375 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9376 Set inferior debugging."), _("\
9377 Show inferior debugging."), _("\
9378 When non-zero, inferior specific debugging is enabled."),
9381 &setdebuglist
, &showdebuglist
);
9383 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9384 &debug_displaced
, _("\
9385 Set displaced stepping debugging."), _("\
9386 Show displaced stepping debugging."), _("\
9387 When non-zero, displaced stepping specific debugging is enabled."),
9389 show_debug_displaced
,
9390 &setdebuglist
, &showdebuglist
);
9392 add_setshow_boolean_cmd ("non-stop", no_class
,
9394 Set whether gdb controls the inferior in non-stop mode."), _("\
9395 Show whether gdb controls the inferior in non-stop mode."), _("\
9396 When debugging a multi-threaded program and this setting is\n\
9397 off (the default, also called all-stop mode), when one thread stops\n\
9398 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9399 all other threads in the program while you interact with the thread of\n\
9400 interest. When you continue or step a thread, you can allow the other\n\
9401 threads to run, or have them remain stopped, but while you inspect any\n\
9402 thread's state, all threads stop.\n\
9404 In non-stop mode, when one thread stops, other threads can continue\n\
9405 to run freely. You'll be able to step each thread independently,\n\
9406 leave it stopped or free to run as needed."),
9412 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9415 signal_print
[i
] = 1;
9416 signal_program
[i
] = 1;
9417 signal_catch
[i
] = 0;
9420 /* Signals caused by debugger's own actions should not be given to
9421 the program afterwards.
9423 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9424 explicitly specifies that it should be delivered to the target
9425 program. Typically, that would occur when a user is debugging a
9426 target monitor on a simulator: the target monitor sets a
9427 breakpoint; the simulator encounters this breakpoint and halts
9428 the simulation handing control to GDB; GDB, noting that the stop
9429 address doesn't map to any known breakpoint, returns control back
9430 to the simulator; the simulator then delivers the hardware
9431 equivalent of a GDB_SIGNAL_TRAP to the program being
9433 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9434 signal_program
[GDB_SIGNAL_INT
] = 0;
9436 /* Signals that are not errors should not normally enter the debugger. */
9437 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9438 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9439 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9440 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9441 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9442 signal_print
[GDB_SIGNAL_PROF
] = 0;
9443 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9444 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9445 signal_stop
[GDB_SIGNAL_IO
] = 0;
9446 signal_print
[GDB_SIGNAL_IO
] = 0;
9447 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9448 signal_print
[GDB_SIGNAL_POLL
] = 0;
9449 signal_stop
[GDB_SIGNAL_URG
] = 0;
9450 signal_print
[GDB_SIGNAL_URG
] = 0;
9451 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9452 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9453 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9454 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9456 /* These signals are used internally by user-level thread
9457 implementations. (See signal(5) on Solaris.) Like the above
9458 signals, a healthy program receives and handles them as part of
9459 its normal operation. */
9460 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9461 signal_print
[GDB_SIGNAL_LWP
] = 0;
9462 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9463 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9464 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9465 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9466 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9467 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9469 /* Update cached state. */
9470 signal_cache_update (-1);
9472 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9473 &stop_on_solib_events
, _("\
9474 Set stopping for shared library events."), _("\
9475 Show stopping for shared library events."), _("\
9476 If nonzero, gdb will give control to the user when the dynamic linker\n\
9477 notifies gdb of shared library events. The most common event of interest\n\
9478 to the user would be loading/unloading of a new library."),
9479 set_stop_on_solib_events
,
9480 show_stop_on_solib_events
,
9481 &setlist
, &showlist
);
9483 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9484 follow_fork_mode_kind_names
,
9485 &follow_fork_mode_string
, _("\
9486 Set debugger response to a program call of fork or vfork."), _("\
9487 Show debugger response to a program call of fork or vfork."), _("\
9488 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9489 parent - the original process is debugged after a fork\n\
9490 child - the new process is debugged after a fork\n\
9491 The unfollowed process will continue to run.\n\
9492 By default, the debugger will follow the parent process."),
9494 show_follow_fork_mode_string
,
9495 &setlist
, &showlist
);
9497 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9498 follow_exec_mode_names
,
9499 &follow_exec_mode_string
, _("\
9500 Set debugger response to a program call of exec."), _("\
9501 Show debugger response to a program call of exec."), _("\
9502 An exec call replaces the program image of a process.\n\
9504 follow-exec-mode can be:\n\
9506 new - the debugger creates a new inferior and rebinds the process\n\
9507 to this new inferior. The program the process was running before\n\
9508 the exec call can be restarted afterwards by restarting the original\n\
9511 same - the debugger keeps the process bound to the same inferior.\n\
9512 The new executable image replaces the previous executable loaded in\n\
9513 the inferior. Restarting the inferior after the exec call restarts\n\
9514 the executable the process was running after the exec call.\n\
9516 By default, the debugger will use the same inferior."),
9518 show_follow_exec_mode_string
,
9519 &setlist
, &showlist
);
9521 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9522 scheduler_enums
, &scheduler_mode
, _("\
9523 Set mode for locking scheduler during execution."), _("\
9524 Show mode for locking scheduler during execution."), _("\
9525 off == no locking (threads may preempt at any time)\n\
9526 on == full locking (no thread except the current thread may run)\n\
9527 This applies to both normal execution and replay mode.\n\
9528 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9529 In this mode, other threads may run during other commands.\n\
9530 This applies to both normal execution and replay mode.\n\
9531 replay == scheduler locked in replay mode and unlocked during normal execution."),
9532 set_schedlock_func
, /* traps on target vector */
9533 show_scheduler_mode
,
9534 &setlist
, &showlist
);
9536 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9537 Set mode for resuming threads of all processes."), _("\
9538 Show mode for resuming threads of all processes."), _("\
9539 When on, execution commands (such as 'continue' or 'next') resume all\n\
9540 threads of all processes. When off (which is the default), execution\n\
9541 commands only resume the threads of the current process. The set of\n\
9542 threads that are resumed is further refined by the scheduler-locking\n\
9543 mode (see help set scheduler-locking)."),
9545 show_schedule_multiple
,
9546 &setlist
, &showlist
);
9548 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9549 Set mode of the step operation."), _("\
9550 Show mode of the step operation."), _("\
9551 When set, doing a step over a function without debug line information\n\
9552 will stop at the first instruction of that function. Otherwise, the\n\
9553 function is skipped and the step command stops at a different source line."),
9555 show_step_stop_if_no_debug
,
9556 &setlist
, &showlist
);
9558 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9559 &can_use_displaced_stepping
, _("\
9560 Set debugger's willingness to use displaced stepping."), _("\
9561 Show debugger's willingness to use displaced stepping."), _("\
9562 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9563 supported by the target architecture. If off, gdb will not use displaced\n\
9564 stepping to step over breakpoints, even if such is supported by the target\n\
9565 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9566 if the target architecture supports it and non-stop mode is active, but will not\n\
9567 use it in all-stop mode (see help set non-stop)."),
9569 show_can_use_displaced_stepping
,
9570 &setlist
, &showlist
);
9572 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9573 &exec_direction
, _("Set direction of execution.\n\
9574 Options are 'forward' or 'reverse'."),
9575 _("Show direction of execution (forward/reverse)."),
9576 _("Tells gdb whether to execute forward or backward."),
9577 set_exec_direction_func
, show_exec_direction_func
,
9578 &setlist
, &showlist
);
9580 /* Set/show detach-on-fork: user-settable mode. */
9582 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9583 Set whether gdb will detach the child of a fork."), _("\
9584 Show whether gdb will detach the child of a fork."), _("\
9585 Tells gdb whether to detach the child of a fork."),
9586 NULL
, NULL
, &setlist
, &showlist
);
9588 /* Set/show disable address space randomization mode. */
9590 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9591 &disable_randomization
, _("\
9592 Set disabling of debuggee's virtual address space randomization."), _("\
9593 Show disabling of debuggee's virtual address space randomization."), _("\
9594 When this mode is on (which is the default), randomization of the virtual\n\
9595 address space is disabled. Standalone programs run with the randomization\n\
9596 enabled by default on some platforms."),
9597 &set_disable_randomization
,
9598 &show_disable_randomization
,
9599 &setlist
, &showlist
);
9601 /* ptid initializations */
9602 inferior_ptid
= null_ptid
;
9603 target_last_wait_ptid
= minus_one_ptid
;
9605 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9606 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9607 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9608 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9610 /* Explicitly create without lookup, since that tries to create a
9611 value with a void typed value, and when we get here, gdbarch
9612 isn't initialized yet. At this point, we're quite sure there
9613 isn't another convenience variable of the same name. */
9614 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9616 add_setshow_boolean_cmd ("observer", no_class
,
9617 &observer_mode_1
, _("\
9618 Set whether gdb controls the inferior in observer mode."), _("\
9619 Show whether gdb controls the inferior in observer mode."), _("\
9620 In observer mode, GDB can get data from the inferior, but not\n\
9621 affect its execution. Registers and memory may not be changed,\n\
9622 breakpoints may not be set, and the program cannot be interrupted\n\