1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "target-connection.h"
32 #include "gdbthread.h"
39 #include "observable.h"
44 #include "mi/mi-common.h"
45 #include "event-top.h"
47 #include "record-full.h"
48 #include "inline-frame.h"
50 #include "tracepoint.h"
54 #include "completer.h"
55 #include "target-descriptions.h"
56 #include "target-dcache.h"
59 #include "event-loop.h"
60 #include "thread-fsm.h"
61 #include "gdbsupport/enum-flags.h"
62 #include "progspace-and-thread.h"
63 #include "gdbsupport/gdb_optional.h"
64 #include "arch-utils.h"
65 #include "gdbsupport/scope-exit.h"
66 #include "gdbsupport/forward-scope-exit.h"
67 #include "gdb_select.h"
68 #include <unordered_map>
70 /* Prototypes for local functions */
72 static void sig_print_info (enum gdb_signal
);
74 static void sig_print_header (void);
76 static void follow_inferior_reset_breakpoints (void);
78 static int currently_stepping (struct thread_info
*tp
);
80 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
82 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
84 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
86 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
88 static void resume (gdb_signal sig
);
90 static void wait_for_inferior (inferior
*inf
);
92 /* Asynchronous signal handler registered as event loop source for
93 when we have pending events ready to be passed to the core. */
94 static struct async_event_handler
*infrun_async_inferior_event_token
;
96 /* Stores whether infrun_async was previously enabled or disabled.
97 Starts off as -1, indicating "never enabled/disabled". */
98 static int infrun_is_async
= -1;
103 infrun_async (int enable
)
105 if (infrun_is_async
!= enable
)
107 infrun_is_async
= enable
;
110 fprintf_unfiltered (gdb_stdlog
,
111 "infrun: infrun_async(%d)\n",
115 mark_async_event_handler (infrun_async_inferior_event_token
);
117 clear_async_event_handler (infrun_async_inferior_event_token
);
124 mark_infrun_async_event_handler (void)
126 mark_async_event_handler (infrun_async_inferior_event_token
);
129 /* When set, stop the 'step' command if we enter a function which has
130 no line number information. The normal behavior is that we step
131 over such function. */
132 bool step_stop_if_no_debug
= false;
134 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
135 struct cmd_list_element
*c
, const char *value
)
137 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
140 /* proceed and normal_stop use this to notify the user when the
141 inferior stopped in a different thread than it had been running
144 static ptid_t previous_inferior_ptid
;
146 /* If set (default for legacy reasons), when following a fork, GDB
147 will detach from one of the fork branches, child or parent.
148 Exactly which branch is detached depends on 'set follow-fork-mode'
151 static bool detach_fork
= true;
153 bool debug_displaced
= false;
155 show_debug_displaced (struct ui_file
*file
, int from_tty
,
156 struct cmd_list_element
*c
, const char *value
)
158 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
161 unsigned int debug_infrun
= 0;
163 show_debug_infrun (struct ui_file
*file
, int from_tty
,
164 struct cmd_list_element
*c
, const char *value
)
166 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
170 /* Support for disabling address space randomization. */
172 bool disable_randomization
= true;
175 show_disable_randomization (struct ui_file
*file
, int from_tty
,
176 struct cmd_list_element
*c
, const char *value
)
178 if (target_supports_disable_randomization ())
179 fprintf_filtered (file
,
180 _("Disabling randomization of debuggee's "
181 "virtual address space is %s.\n"),
184 fputs_filtered (_("Disabling randomization of debuggee's "
185 "virtual address space is unsupported on\n"
186 "this platform.\n"), file
);
190 set_disable_randomization (const char *args
, int from_tty
,
191 struct cmd_list_element
*c
)
193 if (!target_supports_disable_randomization ())
194 error (_("Disabling randomization of debuggee's "
195 "virtual address space is unsupported on\n"
199 /* User interface for non-stop mode. */
201 bool non_stop
= false;
202 static bool non_stop_1
= false;
205 set_non_stop (const char *args
, int from_tty
,
206 struct cmd_list_element
*c
)
208 if (target_has_execution
)
210 non_stop_1
= non_stop
;
211 error (_("Cannot change this setting while the inferior is running."));
214 non_stop
= non_stop_1
;
218 show_non_stop (struct ui_file
*file
, int from_tty
,
219 struct cmd_list_element
*c
, const char *value
)
221 fprintf_filtered (file
,
222 _("Controlling the inferior in non-stop mode is %s.\n"),
226 /* "Observer mode" is somewhat like a more extreme version of
227 non-stop, in which all GDB operations that might affect the
228 target's execution have been disabled. */
230 bool observer_mode
= false;
231 static bool observer_mode_1
= false;
234 set_observer_mode (const char *args
, int from_tty
,
235 struct cmd_list_element
*c
)
237 if (target_has_execution
)
239 observer_mode_1
= observer_mode
;
240 error (_("Cannot change this setting while the inferior is running."));
243 observer_mode
= observer_mode_1
;
245 may_write_registers
= !observer_mode
;
246 may_write_memory
= !observer_mode
;
247 may_insert_breakpoints
= !observer_mode
;
248 may_insert_tracepoints
= !observer_mode
;
249 /* We can insert fast tracepoints in or out of observer mode,
250 but enable them if we're going into this mode. */
252 may_insert_fast_tracepoints
= true;
253 may_stop
= !observer_mode
;
254 update_target_permissions ();
256 /* Going *into* observer mode we must force non-stop, then
257 going out we leave it that way. */
260 pagination_enabled
= 0;
261 non_stop
= non_stop_1
= true;
265 printf_filtered (_("Observer mode is now %s.\n"),
266 (observer_mode
? "on" : "off"));
270 show_observer_mode (struct ui_file
*file
, int from_tty
,
271 struct cmd_list_element
*c
, const char *value
)
273 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
276 /* This updates the value of observer mode based on changes in
277 permissions. Note that we are deliberately ignoring the values of
278 may-write-registers and may-write-memory, since the user may have
279 reason to enable these during a session, for instance to turn on a
280 debugging-related global. */
283 update_observer_mode (void)
285 bool newval
= (!may_insert_breakpoints
286 && !may_insert_tracepoints
287 && may_insert_fast_tracepoints
291 /* Let the user know if things change. */
292 if (newval
!= observer_mode
)
293 printf_filtered (_("Observer mode is now %s.\n"),
294 (newval
? "on" : "off"));
296 observer_mode
= observer_mode_1
= newval
;
299 /* Tables of how to react to signals; the user sets them. */
301 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
302 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
303 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
305 /* Table of signals that are registered with "catch signal". A
306 non-zero entry indicates that the signal is caught by some "catch
308 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
310 /* Table of signals that the target may silently handle.
311 This is automatically determined from the flags above,
312 and simply cached here. */
313 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
315 #define SET_SIGS(nsigs,sigs,flags) \
317 int signum = (nsigs); \
318 while (signum-- > 0) \
319 if ((sigs)[signum]) \
320 (flags)[signum] = 1; \
323 #define UNSET_SIGS(nsigs,sigs,flags) \
325 int signum = (nsigs); \
326 while (signum-- > 0) \
327 if ((sigs)[signum]) \
328 (flags)[signum] = 0; \
331 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
332 this function is to avoid exporting `signal_program'. */
335 update_signals_program_target (void)
337 target_program_signals (signal_program
);
340 /* Value to pass to target_resume() to cause all threads to resume. */
342 #define RESUME_ALL minus_one_ptid
344 /* Command list pointer for the "stop" placeholder. */
346 static struct cmd_list_element
*stop_command
;
348 /* Nonzero if we want to give control to the user when we're notified
349 of shared library events by the dynamic linker. */
350 int stop_on_solib_events
;
352 /* Enable or disable optional shared library event breakpoints
353 as appropriate when the above flag is changed. */
356 set_stop_on_solib_events (const char *args
,
357 int from_tty
, struct cmd_list_element
*c
)
359 update_solib_breakpoints ();
363 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
364 struct cmd_list_element
*c
, const char *value
)
366 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
370 /* Nonzero after stop if current stack frame should be printed. */
372 static int stop_print_frame
;
374 /* This is a cached copy of the target/ptid/waitstatus of the last
375 event returned by target_wait()/deprecated_target_wait_hook().
376 This information is returned by get_last_target_status(). */
377 static process_stratum_target
*target_last_proc_target
;
378 static ptid_t target_last_wait_ptid
;
379 static struct target_waitstatus target_last_waitstatus
;
381 void init_thread_stepping_state (struct thread_info
*tss
);
383 static const char follow_fork_mode_child
[] = "child";
384 static const char follow_fork_mode_parent
[] = "parent";
386 static const char *const follow_fork_mode_kind_names
[] = {
387 follow_fork_mode_child
,
388 follow_fork_mode_parent
,
392 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
394 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
395 struct cmd_list_element
*c
, const char *value
)
397 fprintf_filtered (file
,
398 _("Debugger response to a program "
399 "call of fork or vfork is \"%s\".\n"),
404 /* Handle changes to the inferior list based on the type of fork,
405 which process is being followed, and whether the other process
406 should be detached. On entry inferior_ptid must be the ptid of
407 the fork parent. At return inferior_ptid is the ptid of the
408 followed inferior. */
411 follow_fork_inferior (bool follow_child
, bool detach_fork
)
414 ptid_t parent_ptid
, child_ptid
;
416 has_vforked
= (inferior_thread ()->pending_follow
.kind
417 == TARGET_WAITKIND_VFORKED
);
418 parent_ptid
= inferior_ptid
;
419 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
422 && !non_stop
/* Non-stop always resumes both branches. */
423 && current_ui
->prompt_state
== PROMPT_BLOCKED
424 && !(follow_child
|| detach_fork
|| sched_multi
))
426 /* The parent stays blocked inside the vfork syscall until the
427 child execs or exits. If we don't let the child run, then
428 the parent stays blocked. If we're telling the parent to run
429 in the foreground, the user will not be able to ctrl-c to get
430 back the terminal, effectively hanging the debug session. */
431 fprintf_filtered (gdb_stderr
, _("\
432 Can not resume the parent process over vfork in the foreground while\n\
433 holding the child stopped. Try \"set detach-on-fork\" or \
434 \"set schedule-multiple\".\n"));
440 /* Detach new forked process? */
443 /* Before detaching from the child, remove all breakpoints
444 from it. If we forked, then this has already been taken
445 care of by infrun.c. If we vforked however, any
446 breakpoint inserted in the parent is visible in the
447 child, even those added while stopped in a vfork
448 catchpoint. This will remove the breakpoints from the
449 parent also, but they'll be reinserted below. */
452 /* Keep breakpoints list in sync. */
453 remove_breakpoints_inf (current_inferior ());
456 if (print_inferior_events
)
458 /* Ensure that we have a process ptid. */
459 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
461 target_terminal::ours_for_output ();
462 fprintf_filtered (gdb_stdlog
,
463 _("[Detaching after %s from child %s]\n"),
464 has_vforked
? "vfork" : "fork",
465 target_pid_to_str (process_ptid
).c_str ());
470 struct inferior
*parent_inf
, *child_inf
;
472 /* Add process to GDB's tables. */
473 child_inf
= add_inferior (child_ptid
.pid ());
475 parent_inf
= current_inferior ();
476 child_inf
->attach_flag
= parent_inf
->attach_flag
;
477 copy_terminal_info (child_inf
, parent_inf
);
478 child_inf
->gdbarch
= parent_inf
->gdbarch
;
479 copy_inferior_target_desc_info (child_inf
, parent_inf
);
481 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
483 set_current_inferior (child_inf
);
484 switch_to_no_thread ();
485 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
486 push_target (parent_inf
->process_target ());
487 add_thread_silent (child_inf
->process_target (), child_ptid
);
488 inferior_ptid
= child_ptid
;
490 /* If this is a vfork child, then the address-space is
491 shared with the parent. */
494 child_inf
->pspace
= parent_inf
->pspace
;
495 child_inf
->aspace
= parent_inf
->aspace
;
499 /* The parent will be frozen until the child is done
500 with the shared region. Keep track of the
502 child_inf
->vfork_parent
= parent_inf
;
503 child_inf
->pending_detach
= 0;
504 parent_inf
->vfork_child
= child_inf
;
505 parent_inf
->pending_detach
= 0;
509 child_inf
->aspace
= new_address_space ();
510 child_inf
->pspace
= new program_space (child_inf
->aspace
);
511 child_inf
->removable
= 1;
512 set_current_program_space (child_inf
->pspace
);
513 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
515 /* Let the shared library layer (e.g., solib-svr4) learn
516 about this new process, relocate the cloned exec, pull
517 in shared libraries, and install the solib event
518 breakpoint. If a "cloned-VM" event was propagated
519 better throughout the core, this wouldn't be
521 solib_create_inferior_hook (0);
527 struct inferior
*parent_inf
;
529 parent_inf
= current_inferior ();
531 /* If we detached from the child, then we have to be careful
532 to not insert breakpoints in the parent until the child
533 is done with the shared memory region. However, if we're
534 staying attached to the child, then we can and should
535 insert breakpoints, so that we can debug it. A
536 subsequent child exec or exit is enough to know when does
537 the child stops using the parent's address space. */
538 parent_inf
->waiting_for_vfork_done
= detach_fork
;
539 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
544 /* Follow the child. */
545 struct inferior
*parent_inf
, *child_inf
;
546 struct program_space
*parent_pspace
;
548 if (print_inferior_events
)
550 std::string parent_pid
= target_pid_to_str (parent_ptid
);
551 std::string child_pid
= target_pid_to_str (child_ptid
);
553 target_terminal::ours_for_output ();
554 fprintf_filtered (gdb_stdlog
,
555 _("[Attaching after %s %s to child %s]\n"),
557 has_vforked
? "vfork" : "fork",
561 /* Add the new inferior first, so that the target_detach below
562 doesn't unpush the target. */
564 child_inf
= add_inferior (child_ptid
.pid ());
566 parent_inf
= current_inferior ();
567 child_inf
->attach_flag
= parent_inf
->attach_flag
;
568 copy_terminal_info (child_inf
, parent_inf
);
569 child_inf
->gdbarch
= parent_inf
->gdbarch
;
570 copy_inferior_target_desc_info (child_inf
, parent_inf
);
572 parent_pspace
= parent_inf
->pspace
;
574 process_stratum_target
*target
= parent_inf
->process_target ();
577 /* Hold a strong reference to the target while (maybe)
578 detaching the parent. Otherwise detaching could close the
580 auto target_ref
= target_ops_ref::new_reference (target
);
582 /* If we're vforking, we want to hold on to the parent until
583 the child exits or execs. At child exec or exit time we
584 can remove the old breakpoints from the parent and detach
585 or resume debugging it. Otherwise, detach the parent now;
586 we'll want to reuse it's program/address spaces, but we
587 can't set them to the child before removing breakpoints
588 from the parent, otherwise, the breakpoints module could
589 decide to remove breakpoints from the wrong process (since
590 they'd be assigned to the same address space). */
594 gdb_assert (child_inf
->vfork_parent
== NULL
);
595 gdb_assert (parent_inf
->vfork_child
== NULL
);
596 child_inf
->vfork_parent
= parent_inf
;
597 child_inf
->pending_detach
= 0;
598 parent_inf
->vfork_child
= child_inf
;
599 parent_inf
->pending_detach
= detach_fork
;
600 parent_inf
->waiting_for_vfork_done
= 0;
602 else if (detach_fork
)
604 if (print_inferior_events
)
606 /* Ensure that we have a process ptid. */
607 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
609 target_terminal::ours_for_output ();
610 fprintf_filtered (gdb_stdlog
,
611 _("[Detaching after fork from "
613 target_pid_to_str (process_ptid
).c_str ());
616 target_detach (parent_inf
, 0);
620 /* Note that the detach above makes PARENT_INF dangling. */
622 /* Add the child thread to the appropriate lists, and switch
623 to this new thread, before cloning the program space, and
624 informing the solib layer about this new process. */
626 set_current_inferior (child_inf
);
627 push_target (target
);
630 add_thread_silent (target
, child_ptid
);
631 inferior_ptid
= child_ptid
;
633 /* If this is a vfork child, then the address-space is shared
634 with the parent. If we detached from the parent, then we can
635 reuse the parent's program/address spaces. */
636 if (has_vforked
|| detach_fork
)
638 child_inf
->pspace
= parent_pspace
;
639 child_inf
->aspace
= child_inf
->pspace
->aspace
;
645 child_inf
->aspace
= new_address_space ();
646 child_inf
->pspace
= new program_space (child_inf
->aspace
);
647 child_inf
->removable
= 1;
648 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
649 set_current_program_space (child_inf
->pspace
);
650 clone_program_space (child_inf
->pspace
, parent_pspace
);
652 /* Let the shared library layer (e.g., solib-svr4) learn
653 about this new process, relocate the cloned exec, pull in
654 shared libraries, and install the solib event breakpoint.
655 If a "cloned-VM" event was propagated better throughout
656 the core, this wouldn't be required. */
657 solib_create_inferior_hook (0);
661 return target_follow_fork (follow_child
, detach_fork
);
664 /* Tell the target to follow the fork we're stopped at. Returns true
665 if the inferior should be resumed; false, if the target for some
666 reason decided it's best not to resume. */
671 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
672 bool should_resume
= true;
673 struct thread_info
*tp
;
675 /* Copy user stepping state to the new inferior thread. FIXME: the
676 followed fork child thread should have a copy of most of the
677 parent thread structure's run control related fields, not just these.
678 Initialized to avoid "may be used uninitialized" warnings from gcc. */
679 struct breakpoint
*step_resume_breakpoint
= NULL
;
680 struct breakpoint
*exception_resume_breakpoint
= NULL
;
681 CORE_ADDR step_range_start
= 0;
682 CORE_ADDR step_range_end
= 0;
683 struct frame_id step_frame_id
= { 0 };
684 struct thread_fsm
*thread_fsm
= NULL
;
688 process_stratum_target
*wait_target
;
690 struct target_waitstatus wait_status
;
692 /* Get the last target status returned by target_wait(). */
693 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
695 /* If not stopped at a fork event, then there's nothing else to
697 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
698 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
701 /* Check if we switched over from WAIT_PTID, since the event was
703 if (wait_ptid
!= minus_one_ptid
704 && (current_inferior ()->process_target () != wait_target
705 || inferior_ptid
!= wait_ptid
))
707 /* We did. Switch back to WAIT_PTID thread, to tell the
708 target to follow it (in either direction). We'll
709 afterwards refuse to resume, and inform the user what
711 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
712 switch_to_thread (wait_thread
);
713 should_resume
= false;
717 tp
= inferior_thread ();
719 /* If there were any forks/vforks that were caught and are now to be
720 followed, then do so now. */
721 switch (tp
->pending_follow
.kind
)
723 case TARGET_WAITKIND_FORKED
:
724 case TARGET_WAITKIND_VFORKED
:
726 ptid_t parent
, child
;
728 /* If the user did a next/step, etc, over a fork call,
729 preserve the stepping state in the fork child. */
730 if (follow_child
&& should_resume
)
732 step_resume_breakpoint
= clone_momentary_breakpoint
733 (tp
->control
.step_resume_breakpoint
);
734 step_range_start
= tp
->control
.step_range_start
;
735 step_range_end
= tp
->control
.step_range_end
;
736 step_frame_id
= tp
->control
.step_frame_id
;
737 exception_resume_breakpoint
738 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
739 thread_fsm
= tp
->thread_fsm
;
741 /* For now, delete the parent's sr breakpoint, otherwise,
742 parent/child sr breakpoints are considered duplicates,
743 and the child version will not be installed. Remove
744 this when the breakpoints module becomes aware of
745 inferiors and address spaces. */
746 delete_step_resume_breakpoint (tp
);
747 tp
->control
.step_range_start
= 0;
748 tp
->control
.step_range_end
= 0;
749 tp
->control
.step_frame_id
= null_frame_id
;
750 delete_exception_resume_breakpoint (tp
);
751 tp
->thread_fsm
= NULL
;
754 parent
= inferior_ptid
;
755 child
= tp
->pending_follow
.value
.related_pid
;
757 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
758 /* Set up inferior(s) as specified by the caller, and tell the
759 target to do whatever is necessary to follow either parent
761 if (follow_fork_inferior (follow_child
, detach_fork
))
763 /* Target refused to follow, or there's some other reason
764 we shouldn't resume. */
769 /* This pending follow fork event is now handled, one way
770 or another. The previous selected thread may be gone
771 from the lists by now, but if it is still around, need
772 to clear the pending follow request. */
773 tp
= find_thread_ptid (parent_targ
, parent
);
775 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
777 /* This makes sure we don't try to apply the "Switched
778 over from WAIT_PID" logic above. */
779 nullify_last_target_wait_ptid ();
781 /* If we followed the child, switch to it... */
784 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
785 switch_to_thread (child_thr
);
787 /* ... and preserve the stepping state, in case the
788 user was stepping over the fork call. */
791 tp
= inferior_thread ();
792 tp
->control
.step_resume_breakpoint
793 = step_resume_breakpoint
;
794 tp
->control
.step_range_start
= step_range_start
;
795 tp
->control
.step_range_end
= step_range_end
;
796 tp
->control
.step_frame_id
= step_frame_id
;
797 tp
->control
.exception_resume_breakpoint
798 = exception_resume_breakpoint
;
799 tp
->thread_fsm
= thread_fsm
;
803 /* If we get here, it was because we're trying to
804 resume from a fork catchpoint, but, the user
805 has switched threads away from the thread that
806 forked. In that case, the resume command
807 issued is most likely not applicable to the
808 child, so just warn, and refuse to resume. */
809 warning (_("Not resuming: switched threads "
810 "before following fork child."));
813 /* Reset breakpoints in the child as appropriate. */
814 follow_inferior_reset_breakpoints ();
819 case TARGET_WAITKIND_SPURIOUS
:
820 /* Nothing to follow. */
823 internal_error (__FILE__
, __LINE__
,
824 "Unexpected pending_follow.kind %d\n",
825 tp
->pending_follow
.kind
);
829 return should_resume
;
833 follow_inferior_reset_breakpoints (void)
835 struct thread_info
*tp
= inferior_thread ();
837 /* Was there a step_resume breakpoint? (There was if the user
838 did a "next" at the fork() call.) If so, explicitly reset its
839 thread number. Cloned step_resume breakpoints are disabled on
840 creation, so enable it here now that it is associated with the
843 step_resumes are a form of bp that are made to be per-thread.
844 Since we created the step_resume bp when the parent process
845 was being debugged, and now are switching to the child process,
846 from the breakpoint package's viewpoint, that's a switch of
847 "threads". We must update the bp's notion of which thread
848 it is for, or it'll be ignored when it triggers. */
850 if (tp
->control
.step_resume_breakpoint
)
852 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
853 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
856 /* Treat exception_resume breakpoints like step_resume breakpoints. */
857 if (tp
->control
.exception_resume_breakpoint
)
859 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
860 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
863 /* Reinsert all breakpoints in the child. The user may have set
864 breakpoints after catching the fork, in which case those
865 were never set in the child, but only in the parent. This makes
866 sure the inserted breakpoints match the breakpoint list. */
868 breakpoint_re_set ();
869 insert_breakpoints ();
872 /* The child has exited or execed: resume threads of the parent the
873 user wanted to be executing. */
876 proceed_after_vfork_done (struct thread_info
*thread
,
879 int pid
= * (int *) arg
;
881 if (thread
->ptid
.pid () == pid
882 && thread
->state
== THREAD_RUNNING
883 && !thread
->executing
884 && !thread
->stop_requested
885 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
888 fprintf_unfiltered (gdb_stdlog
,
889 "infrun: resuming vfork parent thread %s\n",
890 target_pid_to_str (thread
->ptid
).c_str ());
892 switch_to_thread (thread
);
893 clear_proceed_status (0);
894 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
900 /* Save/restore inferior_ptid, current program space and current
901 inferior. Only use this if the current context points at an exited
902 inferior (and therefore there's no current thread to save). */
903 class scoped_restore_exited_inferior
906 scoped_restore_exited_inferior ()
907 : m_saved_ptid (&inferior_ptid
)
911 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
912 scoped_restore_current_program_space m_pspace
;
913 scoped_restore_current_inferior m_inferior
;
916 /* Called whenever we notice an exec or exit event, to handle
917 detaching or resuming a vfork parent. */
920 handle_vfork_child_exec_or_exit (int exec
)
922 struct inferior
*inf
= current_inferior ();
924 if (inf
->vfork_parent
)
926 int resume_parent
= -1;
928 /* This exec or exit marks the end of the shared memory region
929 between the parent and the child. Break the bonds. */
930 inferior
*vfork_parent
= inf
->vfork_parent
;
931 inf
->vfork_parent
->vfork_child
= NULL
;
932 inf
->vfork_parent
= NULL
;
934 /* If the user wanted to detach from the parent, now is the
936 if (vfork_parent
->pending_detach
)
938 struct thread_info
*tp
;
939 struct program_space
*pspace
;
940 struct address_space
*aspace
;
942 /* follow-fork child, detach-on-fork on. */
944 vfork_parent
->pending_detach
= 0;
946 gdb::optional
<scoped_restore_exited_inferior
>
947 maybe_restore_inferior
;
948 gdb::optional
<scoped_restore_current_pspace_and_thread
>
949 maybe_restore_thread
;
951 /* If we're handling a child exit, then inferior_ptid points
952 at the inferior's pid, not to a thread. */
954 maybe_restore_inferior
.emplace ();
956 maybe_restore_thread
.emplace ();
958 /* We're letting loose of the parent. */
959 tp
= any_live_thread_of_inferior (vfork_parent
);
960 switch_to_thread (tp
);
962 /* We're about to detach from the parent, which implicitly
963 removes breakpoints from its address space. There's a
964 catch here: we want to reuse the spaces for the child,
965 but, parent/child are still sharing the pspace at this
966 point, although the exec in reality makes the kernel give
967 the child a fresh set of new pages. The problem here is
968 that the breakpoints module being unaware of this, would
969 likely chose the child process to write to the parent
970 address space. Swapping the child temporarily away from
971 the spaces has the desired effect. Yes, this is "sort
974 pspace
= inf
->pspace
;
975 aspace
= inf
->aspace
;
979 if (print_inferior_events
)
982 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
984 target_terminal::ours_for_output ();
988 fprintf_filtered (gdb_stdlog
,
989 _("[Detaching vfork parent %s "
990 "after child exec]\n"), pidstr
.c_str ());
994 fprintf_filtered (gdb_stdlog
,
995 _("[Detaching vfork parent %s "
996 "after child exit]\n"), pidstr
.c_str ());
1000 target_detach (vfork_parent
, 0);
1003 inf
->pspace
= pspace
;
1004 inf
->aspace
= aspace
;
1008 /* We're staying attached to the parent, so, really give the
1009 child a new address space. */
1010 inf
->pspace
= new program_space (maybe_new_address_space ());
1011 inf
->aspace
= inf
->pspace
->aspace
;
1013 set_current_program_space (inf
->pspace
);
1015 resume_parent
= vfork_parent
->pid
;
1019 /* If this is a vfork child exiting, then the pspace and
1020 aspaces were shared with the parent. Since we're
1021 reporting the process exit, we'll be mourning all that is
1022 found in the address space, and switching to null_ptid,
1023 preparing to start a new inferior. But, since we don't
1024 want to clobber the parent's address/program spaces, we
1025 go ahead and create a new one for this exiting
1028 /* Switch to null_ptid while running clone_program_space, so
1029 that clone_program_space doesn't want to read the
1030 selected frame of a dead process. */
1031 scoped_restore restore_ptid
1032 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1034 inf
->pspace
= new program_space (maybe_new_address_space ());
1035 inf
->aspace
= inf
->pspace
->aspace
;
1036 set_current_program_space (inf
->pspace
);
1038 inf
->symfile_flags
= SYMFILE_NO_READ
;
1039 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1041 resume_parent
= vfork_parent
->pid
;
1044 gdb_assert (current_program_space
== inf
->pspace
);
1046 if (non_stop
&& resume_parent
!= -1)
1048 /* If the user wanted the parent to be running, let it go
1050 scoped_restore_current_thread restore_thread
;
1053 fprintf_unfiltered (gdb_stdlog
,
1054 "infrun: resuming vfork parent process %d\n",
1057 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1062 /* Enum strings for "set|show follow-exec-mode". */
1064 static const char follow_exec_mode_new
[] = "new";
1065 static const char follow_exec_mode_same
[] = "same";
1066 static const char *const follow_exec_mode_names
[] =
1068 follow_exec_mode_new
,
1069 follow_exec_mode_same
,
1073 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1075 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1076 struct cmd_list_element
*c
, const char *value
)
1078 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1081 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1084 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1086 struct inferior
*inf
= current_inferior ();
1087 int pid
= ptid
.pid ();
1088 ptid_t process_ptid
;
1090 /* Switch terminal for any messages produced e.g. by
1091 breakpoint_re_set. */
1092 target_terminal::ours_for_output ();
1094 /* This is an exec event that we actually wish to pay attention to.
1095 Refresh our symbol table to the newly exec'd program, remove any
1096 momentary bp's, etc.
1098 If there are breakpoints, they aren't really inserted now,
1099 since the exec() transformed our inferior into a fresh set
1102 We want to preserve symbolic breakpoints on the list, since
1103 we have hopes that they can be reset after the new a.out's
1104 symbol table is read.
1106 However, any "raw" breakpoints must be removed from the list
1107 (e.g., the solib bp's), since their address is probably invalid
1110 And, we DON'T want to call delete_breakpoints() here, since
1111 that may write the bp's "shadow contents" (the instruction
1112 value that was overwritten with a TRAP instruction). Since
1113 we now have a new a.out, those shadow contents aren't valid. */
1115 mark_breakpoints_out ();
1117 /* The target reports the exec event to the main thread, even if
1118 some other thread does the exec, and even if the main thread was
1119 stopped or already gone. We may still have non-leader threads of
1120 the process on our list. E.g., on targets that don't have thread
1121 exit events (like remote); or on native Linux in non-stop mode if
1122 there were only two threads in the inferior and the non-leader
1123 one is the one that execs (and nothing forces an update of the
1124 thread list up to here). When debugging remotely, it's best to
1125 avoid extra traffic, when possible, so avoid syncing the thread
1126 list with the target, and instead go ahead and delete all threads
1127 of the process but one that reported the event. Note this must
1128 be done before calling update_breakpoints_after_exec, as
1129 otherwise clearing the threads' resources would reference stale
1130 thread breakpoints -- it may have been one of these threads that
1131 stepped across the exec. We could just clear their stepping
1132 states, but as long as we're iterating, might as well delete
1133 them. Deleting them now rather than at the next user-visible
1134 stop provides a nicer sequence of events for user and MI
1136 for (thread_info
*th
: all_threads_safe ())
1137 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1140 /* We also need to clear any left over stale state for the
1141 leader/event thread. E.g., if there was any step-resume
1142 breakpoint or similar, it's gone now. We cannot truly
1143 step-to-next statement through an exec(). */
1144 thread_info
*th
= inferior_thread ();
1145 th
->control
.step_resume_breakpoint
= NULL
;
1146 th
->control
.exception_resume_breakpoint
= NULL
;
1147 th
->control
.single_step_breakpoints
= NULL
;
1148 th
->control
.step_range_start
= 0;
1149 th
->control
.step_range_end
= 0;
1151 /* The user may have had the main thread held stopped in the
1152 previous image (e.g., schedlock on, or non-stop). Release
1154 th
->stop_requested
= 0;
1156 update_breakpoints_after_exec ();
1158 /* What is this a.out's name? */
1159 process_ptid
= ptid_t (pid
);
1160 printf_unfiltered (_("%s is executing new program: %s\n"),
1161 target_pid_to_str (process_ptid
).c_str (),
1164 /* We've followed the inferior through an exec. Therefore, the
1165 inferior has essentially been killed & reborn. */
1167 breakpoint_init_inferior (inf_execd
);
1169 gdb::unique_xmalloc_ptr
<char> exec_file_host
1170 = exec_file_find (exec_file_target
, NULL
);
1172 /* If we were unable to map the executable target pathname onto a host
1173 pathname, tell the user that. Otherwise GDB's subsequent behavior
1174 is confusing. Maybe it would even be better to stop at this point
1175 so that the user can specify a file manually before continuing. */
1176 if (exec_file_host
== NULL
)
1177 warning (_("Could not load symbols for executable %s.\n"
1178 "Do you need \"set sysroot\"?"),
1181 /* Reset the shared library package. This ensures that we get a
1182 shlib event when the child reaches "_start", at which point the
1183 dld will have had a chance to initialize the child. */
1184 /* Also, loading a symbol file below may trigger symbol lookups, and
1185 we don't want those to be satisfied by the libraries of the
1186 previous incarnation of this process. */
1187 no_shared_libraries (NULL
, 0);
1189 if (follow_exec_mode_string
== follow_exec_mode_new
)
1191 /* The user wants to keep the old inferior and program spaces
1192 around. Create a new fresh one, and switch to it. */
1194 /* Do exit processing for the original inferior before setting the new
1195 inferior's pid. Having two inferiors with the same pid would confuse
1196 find_inferior_p(t)id. Transfer the terminal state and info from the
1197 old to the new inferior. */
1198 inf
= add_inferior_with_spaces ();
1199 swap_terminal_info (inf
, current_inferior ());
1200 exit_inferior_silent (current_inferior ());
1203 target_follow_exec (inf
, exec_file_target
);
1205 inferior
*org_inferior
= current_inferior ();
1206 switch_to_inferior_no_thread (inf
);
1207 push_target (org_inferior
->process_target ());
1208 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1209 switch_to_thread (thr
);
1213 /* The old description may no longer be fit for the new image.
1214 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1215 old description; we'll read a new one below. No need to do
1216 this on "follow-exec-mode new", as the old inferior stays
1217 around (its description is later cleared/refetched on
1219 target_clear_description ();
1222 gdb_assert (current_program_space
== inf
->pspace
);
1224 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1225 because the proper displacement for a PIE (Position Independent
1226 Executable) main symbol file will only be computed by
1227 solib_create_inferior_hook below. breakpoint_re_set would fail
1228 to insert the breakpoints with the zero displacement. */
1229 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1231 /* If the target can specify a description, read it. Must do this
1232 after flipping to the new executable (because the target supplied
1233 description must be compatible with the executable's
1234 architecture, and the old executable may e.g., be 32-bit, while
1235 the new one 64-bit), and before anything involving memory or
1237 target_find_description ();
1239 solib_create_inferior_hook (0);
1241 jit_inferior_created_hook ();
1243 breakpoint_re_set ();
1245 /* Reinsert all breakpoints. (Those which were symbolic have
1246 been reset to the proper address in the new a.out, thanks
1247 to symbol_file_command...). */
1248 insert_breakpoints ();
1250 /* The next resume of this inferior should bring it to the shlib
1251 startup breakpoints. (If the user had also set bp's on
1252 "main" from the old (parent) process, then they'll auto-
1253 matically get reset there in the new process.). */
1256 /* The queue of threads that need to do a step-over operation to get
1257 past e.g., a breakpoint. What technique is used to step over the
1258 breakpoint/watchpoint does not matter -- all threads end up in the
1259 same queue, to maintain rough temporal order of execution, in order
1260 to avoid starvation, otherwise, we could e.g., find ourselves
1261 constantly stepping the same couple threads past their breakpoints
1262 over and over, if the single-step finish fast enough. */
1263 struct thread_info
*step_over_queue_head
;
1265 /* Bit flags indicating what the thread needs to step over. */
1267 enum step_over_what_flag
1269 /* Step over a breakpoint. */
1270 STEP_OVER_BREAKPOINT
= 1,
1272 /* Step past a non-continuable watchpoint, in order to let the
1273 instruction execute so we can evaluate the watchpoint
1275 STEP_OVER_WATCHPOINT
= 2
1277 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1279 /* Info about an instruction that is being stepped over. */
1281 struct step_over_info
1283 /* If we're stepping past a breakpoint, this is the address space
1284 and address of the instruction the breakpoint is set at. We'll
1285 skip inserting all breakpoints here. Valid iff ASPACE is
1287 const address_space
*aspace
;
1290 /* The instruction being stepped over triggers a nonsteppable
1291 watchpoint. If true, we'll skip inserting watchpoints. */
1292 int nonsteppable_watchpoint_p
;
1294 /* The thread's global number. */
1298 /* The step-over info of the location that is being stepped over.
1300 Note that with async/breakpoint always-inserted mode, a user might
1301 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1302 being stepped over. As setting a new breakpoint inserts all
1303 breakpoints, we need to make sure the breakpoint being stepped over
1304 isn't inserted then. We do that by only clearing the step-over
1305 info when the step-over is actually finished (or aborted).
1307 Presently GDB can only step over one breakpoint at any given time.
1308 Given threads that can't run code in the same address space as the
1309 breakpoint's can't really miss the breakpoint, GDB could be taught
1310 to step-over at most one breakpoint per address space (so this info
1311 could move to the address space object if/when GDB is extended).
1312 The set of breakpoints being stepped over will normally be much
1313 smaller than the set of all breakpoints, so a flag in the
1314 breakpoint location structure would be wasteful. A separate list
1315 also saves complexity and run-time, as otherwise we'd have to go
1316 through all breakpoint locations clearing their flag whenever we
1317 start a new sequence. Similar considerations weigh against storing
1318 this info in the thread object. Plus, not all step overs actually
1319 have breakpoint locations -- e.g., stepping past a single-step
1320 breakpoint, or stepping to complete a non-continuable
1322 static struct step_over_info step_over_info
;
1324 /* Record the address of the breakpoint/instruction we're currently
1326 N.B. We record the aspace and address now, instead of say just the thread,
1327 because when we need the info later the thread may be running. */
1330 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1331 int nonsteppable_watchpoint_p
,
1334 step_over_info
.aspace
= aspace
;
1335 step_over_info
.address
= address
;
1336 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1337 step_over_info
.thread
= thread
;
1340 /* Called when we're not longer stepping over a breakpoint / an
1341 instruction, so all breakpoints are free to be (re)inserted. */
1344 clear_step_over_info (void)
1347 fprintf_unfiltered (gdb_stdlog
,
1348 "infrun: clear_step_over_info\n");
1349 step_over_info
.aspace
= NULL
;
1350 step_over_info
.address
= 0;
1351 step_over_info
.nonsteppable_watchpoint_p
= 0;
1352 step_over_info
.thread
= -1;
1358 stepping_past_instruction_at (struct address_space
*aspace
,
1361 return (step_over_info
.aspace
!= NULL
1362 && breakpoint_address_match (aspace
, address
,
1363 step_over_info
.aspace
,
1364 step_over_info
.address
));
1370 thread_is_stepping_over_breakpoint (int thread
)
1372 return (step_over_info
.thread
!= -1
1373 && thread
== step_over_info
.thread
);
1379 stepping_past_nonsteppable_watchpoint (void)
1381 return step_over_info
.nonsteppable_watchpoint_p
;
1384 /* Returns true if step-over info is valid. */
1387 step_over_info_valid_p (void)
1389 return (step_over_info
.aspace
!= NULL
1390 || stepping_past_nonsteppable_watchpoint ());
1394 /* Displaced stepping. */
1396 /* In non-stop debugging mode, we must take special care to manage
1397 breakpoints properly; in particular, the traditional strategy for
1398 stepping a thread past a breakpoint it has hit is unsuitable.
1399 'Displaced stepping' is a tactic for stepping one thread past a
1400 breakpoint it has hit while ensuring that other threads running
1401 concurrently will hit the breakpoint as they should.
1403 The traditional way to step a thread T off a breakpoint in a
1404 multi-threaded program in all-stop mode is as follows:
1406 a0) Initially, all threads are stopped, and breakpoints are not
1408 a1) We single-step T, leaving breakpoints uninserted.
1409 a2) We insert breakpoints, and resume all threads.
1411 In non-stop debugging, however, this strategy is unsuitable: we
1412 don't want to have to stop all threads in the system in order to
1413 continue or step T past a breakpoint. Instead, we use displaced
1416 n0) Initially, T is stopped, other threads are running, and
1417 breakpoints are inserted.
1418 n1) We copy the instruction "under" the breakpoint to a separate
1419 location, outside the main code stream, making any adjustments
1420 to the instruction, register, and memory state as directed by
1422 n2) We single-step T over the instruction at its new location.
1423 n3) We adjust the resulting register and memory state as directed
1424 by T's architecture. This includes resetting T's PC to point
1425 back into the main instruction stream.
1428 This approach depends on the following gdbarch methods:
1430 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1431 indicate where to copy the instruction, and how much space must
1432 be reserved there. We use these in step n1.
1434 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1435 address, and makes any necessary adjustments to the instruction,
1436 register contents, and memory. We use this in step n1.
1438 - gdbarch_displaced_step_fixup adjusts registers and memory after
1439 we have successfully single-stepped the instruction, to yield the
1440 same effect the instruction would have had if we had executed it
1441 at its original address. We use this in step n3.
1443 The gdbarch_displaced_step_copy_insn and
1444 gdbarch_displaced_step_fixup functions must be written so that
1445 copying an instruction with gdbarch_displaced_step_copy_insn,
1446 single-stepping across the copied instruction, and then applying
1447 gdbarch_displaced_insn_fixup should have the same effects on the
1448 thread's memory and registers as stepping the instruction in place
1449 would have. Exactly which responsibilities fall to the copy and
1450 which fall to the fixup is up to the author of those functions.
1452 See the comments in gdbarch.sh for details.
1454 Note that displaced stepping and software single-step cannot
1455 currently be used in combination, although with some care I think
1456 they could be made to. Software single-step works by placing
1457 breakpoints on all possible subsequent instructions; if the
1458 displaced instruction is a PC-relative jump, those breakpoints
1459 could fall in very strange places --- on pages that aren't
1460 executable, or at addresses that are not proper instruction
1461 boundaries. (We do generally let other threads run while we wait
1462 to hit the software single-step breakpoint, and they might
1463 encounter such a corrupted instruction.) One way to work around
1464 this would be to have gdbarch_displaced_step_copy_insn fully
1465 simulate the effect of PC-relative instructions (and return NULL)
1466 on architectures that use software single-stepping.
1468 In non-stop mode, we can have independent and simultaneous step
1469 requests, so more than one thread may need to simultaneously step
1470 over a breakpoint. The current implementation assumes there is
1471 only one scratch space per process. In this case, we have to
1472 serialize access to the scratch space. If thread A wants to step
1473 over a breakpoint, but we are currently waiting for some other
1474 thread to complete a displaced step, we leave thread A stopped and
1475 place it in the displaced_step_request_queue. Whenever a displaced
1476 step finishes, we pick the next thread in the queue and start a new
1477 displaced step operation on it. See displaced_step_prepare and
1478 displaced_step_fixup for details. */
1480 /* Default destructor for displaced_step_closure. */
1482 displaced_step_closure::~displaced_step_closure () = default;
1484 /* Get the displaced stepping state of process PID. */
1486 static displaced_step_inferior_state
*
1487 get_displaced_stepping_state (inferior
*inf
)
1489 return &inf
->displaced_step_state
;
1492 /* Returns true if any inferior has a thread doing a displaced
1496 displaced_step_in_progress_any_inferior ()
1498 for (inferior
*i
: all_inferiors ())
1500 if (i
->displaced_step_state
.step_thread
!= nullptr)
1507 /* Return true if thread represented by PTID is doing a displaced
1511 displaced_step_in_progress_thread (thread_info
*thread
)
1513 gdb_assert (thread
!= NULL
);
1515 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1518 /* Return true if process PID has a thread doing a displaced step. */
1521 displaced_step_in_progress (inferior
*inf
)
1523 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1526 /* If inferior is in displaced stepping, and ADDR equals to starting address
1527 of copy area, return corresponding displaced_step_closure. Otherwise,
1530 struct displaced_step_closure
*
1531 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1533 displaced_step_inferior_state
*displaced
1534 = get_displaced_stepping_state (current_inferior ());
1536 /* If checking the mode of displaced instruction in copy area. */
1537 if (displaced
->step_thread
!= nullptr
1538 && displaced
->step_copy
== addr
)
1539 return displaced
->step_closure
.get ();
1545 infrun_inferior_exit (struct inferior
*inf
)
1547 inf
->displaced_step_state
.reset ();
1550 /* If ON, and the architecture supports it, GDB will use displaced
1551 stepping to step over breakpoints. If OFF, or if the architecture
1552 doesn't support it, GDB will instead use the traditional
1553 hold-and-step approach. If AUTO (which is the default), GDB will
1554 decide which technique to use to step over breakpoints depending on
1555 whether the target works in a non-stop way (see use_displaced_stepping). */
1557 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1560 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1561 struct cmd_list_element
*c
,
1564 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1565 fprintf_filtered (file
,
1566 _("Debugger's willingness to use displaced stepping "
1567 "to step over breakpoints is %s (currently %s).\n"),
1568 value
, target_is_non_stop_p () ? "on" : "off");
1570 fprintf_filtered (file
,
1571 _("Debugger's willingness to use displaced stepping "
1572 "to step over breakpoints is %s.\n"), value
);
1575 /* Return true if the gdbarch implements the required methods to use
1576 displaced stepping. */
1579 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1581 /* Only check for the presence of step_copy_insn. Other required methods
1582 are checked by the gdbarch validation. */
1583 return gdbarch_displaced_step_copy_insn_p (arch
);
1586 /* Return non-zero if displaced stepping can/should be used to step
1587 over breakpoints of thread TP. */
1590 use_displaced_stepping (thread_info
*tp
)
1592 /* If the user disabled it explicitly, don't use displaced stepping. */
1593 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1596 /* If "auto", only use displaced stepping if the target operates in a non-stop
1598 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1599 && !target_is_non_stop_p ())
1602 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1604 /* If the architecture doesn't implement displaced stepping, don't use
1606 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1609 /* If recording, don't use displaced stepping. */
1610 if (find_record_target () != nullptr)
1613 displaced_step_inferior_state
*displaced_state
1614 = get_displaced_stepping_state (tp
->inf
);
1616 /* If displaced stepping failed before for this inferior, don't bother trying
1618 if (displaced_state
->failed_before
)
1624 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1627 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1629 displaced
->reset ();
1632 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1633 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1635 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1637 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1639 displaced_step_dump_bytes (struct ui_file
*file
,
1640 const gdb_byte
*buf
,
1645 for (i
= 0; i
< len
; i
++)
1646 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1647 fputs_unfiltered ("\n", file
);
1650 /* Prepare to single-step, using displaced stepping.
1652 Note that we cannot use displaced stepping when we have a signal to
1653 deliver. If we have a signal to deliver and an instruction to step
1654 over, then after the step, there will be no indication from the
1655 target whether the thread entered a signal handler or ignored the
1656 signal and stepped over the instruction successfully --- both cases
1657 result in a simple SIGTRAP. In the first case we mustn't do a
1658 fixup, and in the second case we must --- but we can't tell which.
1659 Comments in the code for 'random signals' in handle_inferior_event
1660 explain how we handle this case instead.
1662 Returns 1 if preparing was successful -- this thread is going to be
1663 stepped now; 0 if displaced stepping this thread got queued; or -1
1664 if this instruction can't be displaced stepped. */
1667 displaced_step_prepare_throw (thread_info
*tp
)
1669 regcache
*regcache
= get_thread_regcache (tp
);
1670 struct gdbarch
*gdbarch
= regcache
->arch ();
1671 const address_space
*aspace
= regcache
->aspace ();
1672 CORE_ADDR original
, copy
;
1676 /* We should never reach this function if the architecture does not
1677 support displaced stepping. */
1678 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1680 /* Nor if the thread isn't meant to step over a breakpoint. */
1681 gdb_assert (tp
->control
.trap_expected
);
1683 /* Disable range stepping while executing in the scratch pad. We
1684 want a single-step even if executing the displaced instruction in
1685 the scratch buffer lands within the stepping range (e.g., a
1687 tp
->control
.may_range_step
= 0;
1689 /* We have to displaced step one thread at a time, as we only have
1690 access to a single scratch space per inferior. */
1692 displaced_step_inferior_state
*displaced
1693 = get_displaced_stepping_state (tp
->inf
);
1695 if (displaced
->step_thread
!= nullptr)
1697 /* Already waiting for a displaced step to finish. Defer this
1698 request and place in queue. */
1700 if (debug_displaced
)
1701 fprintf_unfiltered (gdb_stdlog
,
1702 "displaced: deferring step of %s\n",
1703 target_pid_to_str (tp
->ptid
).c_str ());
1705 thread_step_over_chain_enqueue (tp
);
1710 if (debug_displaced
)
1711 fprintf_unfiltered (gdb_stdlog
,
1712 "displaced: stepping %s now\n",
1713 target_pid_to_str (tp
->ptid
).c_str ());
1716 displaced_step_reset (displaced
);
1718 scoped_restore_current_thread restore_thread
;
1720 switch_to_thread (tp
);
1722 original
= regcache_read_pc (regcache
);
1724 copy
= gdbarch_displaced_step_location (gdbarch
);
1725 len
= gdbarch_max_insn_length (gdbarch
);
1727 if (breakpoint_in_range_p (aspace
, copy
, len
))
1729 /* There's a breakpoint set in the scratch pad location range
1730 (which is usually around the entry point). We'd either
1731 install it before resuming, which would overwrite/corrupt the
1732 scratch pad, or if it was already inserted, this displaced
1733 step would overwrite it. The latter is OK in the sense that
1734 we already assume that no thread is going to execute the code
1735 in the scratch pad range (after initial startup) anyway, but
1736 the former is unacceptable. Simply punt and fallback to
1737 stepping over this breakpoint in-line. */
1738 if (debug_displaced
)
1740 fprintf_unfiltered (gdb_stdlog
,
1741 "displaced: breakpoint set in scratch pad. "
1742 "Stepping over breakpoint in-line instead.\n");
1748 /* Save the original contents of the copy area. */
1749 displaced
->step_saved_copy
.resize (len
);
1750 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1752 throw_error (MEMORY_ERROR
,
1753 _("Error accessing memory address %s (%s) for "
1754 "displaced-stepping scratch space."),
1755 paddress (gdbarch
, copy
), safe_strerror (status
));
1756 if (debug_displaced
)
1758 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1759 paddress (gdbarch
, copy
));
1760 displaced_step_dump_bytes (gdb_stdlog
,
1761 displaced
->step_saved_copy
.data (),
1765 displaced
->step_closure
1766 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1767 if (displaced
->step_closure
== NULL
)
1769 /* The architecture doesn't know how or want to displaced step
1770 this instruction or instruction sequence. Fallback to
1771 stepping over the breakpoint in-line. */
1775 /* Save the information we need to fix things up if the step
1777 displaced
->step_thread
= tp
;
1778 displaced
->step_gdbarch
= gdbarch
;
1779 displaced
->step_original
= original
;
1780 displaced
->step_copy
= copy
;
1783 displaced_step_reset_cleanup
cleanup (displaced
);
1785 /* Resume execution at the copy. */
1786 regcache_write_pc (regcache
, copy
);
1791 if (debug_displaced
)
1792 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1793 paddress (gdbarch
, copy
));
1798 /* Wrapper for displaced_step_prepare_throw that disabled further
1799 attempts at displaced stepping if we get a memory error. */
1802 displaced_step_prepare (thread_info
*thread
)
1808 prepared
= displaced_step_prepare_throw (thread
);
1810 catch (const gdb_exception_error
&ex
)
1812 struct displaced_step_inferior_state
*displaced_state
;
1814 if (ex
.error
!= MEMORY_ERROR
1815 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1820 fprintf_unfiltered (gdb_stdlog
,
1821 "infrun: disabling displaced stepping: %s\n",
1825 /* Be verbose if "set displaced-stepping" is "on", silent if
1827 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1829 warning (_("disabling displaced stepping: %s"),
1833 /* Disable further displaced stepping attempts. */
1835 = get_displaced_stepping_state (thread
->inf
);
1836 displaced_state
->failed_before
= 1;
1843 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1844 const gdb_byte
*myaddr
, int len
)
1846 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1848 inferior_ptid
= ptid
;
1849 write_memory (memaddr
, myaddr
, len
);
1852 /* Restore the contents of the copy area for thread PTID. */
1855 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1858 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1860 write_memory_ptid (ptid
, displaced
->step_copy
,
1861 displaced
->step_saved_copy
.data (), len
);
1862 if (debug_displaced
)
1863 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1864 target_pid_to_str (ptid
).c_str (),
1865 paddress (displaced
->step_gdbarch
,
1866 displaced
->step_copy
));
1869 /* If we displaced stepped an instruction successfully, adjust
1870 registers and memory to yield the same effect the instruction would
1871 have had if we had executed it at its original address, and return
1872 1. If the instruction didn't complete, relocate the PC and return
1873 -1. If the thread wasn't displaced stepping, return 0. */
1876 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1878 struct displaced_step_inferior_state
*displaced
1879 = get_displaced_stepping_state (event_thread
->inf
);
1882 /* Was this event for the thread we displaced? */
1883 if (displaced
->step_thread
!= event_thread
)
1886 displaced_step_reset_cleanup
cleanup (displaced
);
1888 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1890 /* Fixup may need to read memory/registers. Switch to the thread
1891 that we're fixing up. Also, target_stopped_by_watchpoint checks
1892 the current thread. */
1893 switch_to_thread (event_thread
);
1895 /* Did the instruction complete successfully? */
1896 if (signal
== GDB_SIGNAL_TRAP
1897 && !(target_stopped_by_watchpoint ()
1898 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1899 || target_have_steppable_watchpoint
)))
1901 /* Fix up the resulting state. */
1902 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1903 displaced
->step_closure
.get (),
1904 displaced
->step_original
,
1905 displaced
->step_copy
,
1906 get_thread_regcache (displaced
->step_thread
));
1911 /* Since the instruction didn't complete, all we can do is
1913 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1914 CORE_ADDR pc
= regcache_read_pc (regcache
);
1916 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1917 regcache_write_pc (regcache
, pc
);
1924 /* Data to be passed around while handling an event. This data is
1925 discarded between events. */
1926 struct execution_control_state
1928 process_stratum_target
*target
;
1930 /* The thread that got the event, if this was a thread event; NULL
1932 struct thread_info
*event_thread
;
1934 struct target_waitstatus ws
;
1935 int stop_func_filled_in
;
1936 CORE_ADDR stop_func_start
;
1937 CORE_ADDR stop_func_end
;
1938 const char *stop_func_name
;
1941 /* True if the event thread hit the single-step breakpoint of
1942 another thread. Thus the event doesn't cause a stop, the thread
1943 needs to be single-stepped past the single-step breakpoint before
1944 we can switch back to the original stepping thread. */
1945 int hit_singlestep_breakpoint
;
1948 /* Clear ECS and set it to point at TP. */
1951 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1953 memset (ecs
, 0, sizeof (*ecs
));
1954 ecs
->event_thread
= tp
;
1955 ecs
->ptid
= tp
->ptid
;
1958 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1959 static void prepare_to_wait (struct execution_control_state
*ecs
);
1960 static int keep_going_stepped_thread (struct thread_info
*tp
);
1961 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1963 /* Are there any pending step-over requests? If so, run all we can
1964 now and return true. Otherwise, return false. */
1967 start_step_over (void)
1969 struct thread_info
*tp
, *next
;
1971 /* Don't start a new step-over if we already have an in-line
1972 step-over operation ongoing. */
1973 if (step_over_info_valid_p ())
1976 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1978 struct execution_control_state ecss
;
1979 struct execution_control_state
*ecs
= &ecss
;
1980 step_over_what step_what
;
1981 int must_be_in_line
;
1983 gdb_assert (!tp
->stop_requested
);
1985 next
= thread_step_over_chain_next (tp
);
1987 /* If this inferior already has a displaced step in process,
1988 don't start a new one. */
1989 if (displaced_step_in_progress (tp
->inf
))
1992 step_what
= thread_still_needs_step_over (tp
);
1993 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1994 || ((step_what
& STEP_OVER_BREAKPOINT
)
1995 && !use_displaced_stepping (tp
)));
1997 /* We currently stop all threads of all processes to step-over
1998 in-line. If we need to start a new in-line step-over, let
1999 any pending displaced steps finish first. */
2000 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
2003 thread_step_over_chain_remove (tp
);
2005 if (step_over_queue_head
== NULL
)
2008 fprintf_unfiltered (gdb_stdlog
,
2009 "infrun: step-over queue now empty\n");
2012 if (tp
->control
.trap_expected
2016 internal_error (__FILE__
, __LINE__
,
2017 "[%s] has inconsistent state: "
2018 "trap_expected=%d, resumed=%d, executing=%d\n",
2019 target_pid_to_str (tp
->ptid
).c_str (),
2020 tp
->control
.trap_expected
,
2026 fprintf_unfiltered (gdb_stdlog
,
2027 "infrun: resuming [%s] for step-over\n",
2028 target_pid_to_str (tp
->ptid
).c_str ());
2030 /* keep_going_pass_signal skips the step-over if the breakpoint
2031 is no longer inserted. In all-stop, we want to keep looking
2032 for a thread that needs a step-over instead of resuming TP,
2033 because we wouldn't be able to resume anything else until the
2034 target stops again. In non-stop, the resume always resumes
2035 only TP, so it's OK to let the thread resume freely. */
2036 if (!target_is_non_stop_p () && !step_what
)
2039 switch_to_thread (tp
);
2040 reset_ecs (ecs
, tp
);
2041 keep_going_pass_signal (ecs
);
2043 if (!ecs
->wait_some_more
)
2044 error (_("Command aborted."));
2046 gdb_assert (tp
->resumed
);
2048 /* If we started a new in-line step-over, we're done. */
2049 if (step_over_info_valid_p ())
2051 gdb_assert (tp
->control
.trap_expected
);
2055 if (!target_is_non_stop_p ())
2057 /* On all-stop, shouldn't have resumed unless we needed a
2059 gdb_assert (tp
->control
.trap_expected
2060 || tp
->step_after_step_resume_breakpoint
);
2062 /* With remote targets (at least), in all-stop, we can't
2063 issue any further remote commands until the program stops
2068 /* Either the thread no longer needed a step-over, or a new
2069 displaced stepping sequence started. Even in the latter
2070 case, continue looking. Maybe we can also start another
2071 displaced step on a thread of other process. */
2077 /* Update global variables holding ptids to hold NEW_PTID if they were
2078 holding OLD_PTID. */
2080 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2082 if (inferior_ptid
== old_ptid
)
2083 inferior_ptid
= new_ptid
;
2088 static const char schedlock_off
[] = "off";
2089 static const char schedlock_on
[] = "on";
2090 static const char schedlock_step
[] = "step";
2091 static const char schedlock_replay
[] = "replay";
2092 static const char *const scheduler_enums
[] = {
2099 static const char *scheduler_mode
= schedlock_replay
;
2101 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2102 struct cmd_list_element
*c
, const char *value
)
2104 fprintf_filtered (file
,
2105 _("Mode for locking scheduler "
2106 "during execution is \"%s\".\n"),
2111 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2113 if (!target_can_lock_scheduler
)
2115 scheduler_mode
= schedlock_off
;
2116 error (_("Target '%s' cannot support this command."), target_shortname
);
2120 /* True if execution commands resume all threads of all processes by
2121 default; otherwise, resume only threads of the current inferior
2123 bool sched_multi
= false;
2125 /* Try to setup for software single stepping over the specified location.
2126 Return 1 if target_resume() should use hardware single step.
2128 GDBARCH the current gdbarch.
2129 PC the location to step over. */
2132 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2136 if (execution_direction
== EXEC_FORWARD
2137 && gdbarch_software_single_step_p (gdbarch
))
2138 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2146 user_visible_resume_ptid (int step
)
2152 /* With non-stop mode on, threads are always handled
2154 resume_ptid
= inferior_ptid
;
2156 else if ((scheduler_mode
== schedlock_on
)
2157 || (scheduler_mode
== schedlock_step
&& step
))
2159 /* User-settable 'scheduler' mode requires solo thread
2161 resume_ptid
= inferior_ptid
;
2163 else if ((scheduler_mode
== schedlock_replay
)
2164 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2166 /* User-settable 'scheduler' mode requires solo thread resume in replay
2168 resume_ptid
= inferior_ptid
;
2170 else if (!sched_multi
&& target_supports_multi_process ())
2172 /* Resume all threads of the current process (and none of other
2174 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2178 /* Resume all threads of all processes. */
2179 resume_ptid
= RESUME_ALL
;
2187 process_stratum_target
*
2188 user_visible_resume_target (ptid_t resume_ptid
)
2190 return (resume_ptid
== minus_one_ptid
&& sched_multi
2192 : current_inferior ()->process_target ());
2195 /* Return a ptid representing the set of threads that we will resume,
2196 in the perspective of the target, assuming run control handling
2197 does not require leaving some threads stopped (e.g., stepping past
2198 breakpoint). USER_STEP indicates whether we're about to start the
2199 target for a stepping command. */
2202 internal_resume_ptid (int user_step
)
2204 /* In non-stop, we always control threads individually. Note that
2205 the target may always work in non-stop mode even with "set
2206 non-stop off", in which case user_visible_resume_ptid could
2207 return a wildcard ptid. */
2208 if (target_is_non_stop_p ())
2209 return inferior_ptid
;
2211 return user_visible_resume_ptid (user_step
);
2214 /* Wrapper for target_resume, that handles infrun-specific
2218 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2220 struct thread_info
*tp
= inferior_thread ();
2222 gdb_assert (!tp
->stop_requested
);
2224 /* Install inferior's terminal modes. */
2225 target_terminal::inferior ();
2227 /* Avoid confusing the next resume, if the next stop/resume
2228 happens to apply to another thread. */
2229 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2231 /* Advise target which signals may be handled silently.
2233 If we have removed breakpoints because we are stepping over one
2234 in-line (in any thread), we need to receive all signals to avoid
2235 accidentally skipping a breakpoint during execution of a signal
2238 Likewise if we're displaced stepping, otherwise a trap for a
2239 breakpoint in a signal handler might be confused with the
2240 displaced step finishing. We don't make the displaced_step_fixup
2241 step distinguish the cases instead, because:
2243 - a backtrace while stopped in the signal handler would show the
2244 scratch pad as frame older than the signal handler, instead of
2245 the real mainline code.
2247 - when the thread is later resumed, the signal handler would
2248 return to the scratch pad area, which would no longer be
2250 if (step_over_info_valid_p ()
2251 || displaced_step_in_progress (tp
->inf
))
2252 target_pass_signals ({});
2254 target_pass_signals (signal_pass
);
2256 target_resume (resume_ptid
, step
, sig
);
2258 target_commit_resume ();
2260 if (target_can_async_p ())
2264 /* Resume the inferior. SIG is the signal to give the inferior
2265 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2266 call 'resume', which handles exceptions. */
2269 resume_1 (enum gdb_signal sig
)
2271 struct regcache
*regcache
= get_current_regcache ();
2272 struct gdbarch
*gdbarch
= regcache
->arch ();
2273 struct thread_info
*tp
= inferior_thread ();
2274 CORE_ADDR pc
= regcache_read_pc (regcache
);
2275 const address_space
*aspace
= regcache
->aspace ();
2277 /* This represents the user's step vs continue request. When
2278 deciding whether "set scheduler-locking step" applies, it's the
2279 user's intention that counts. */
2280 const int user_step
= tp
->control
.stepping_command
;
2281 /* This represents what we'll actually request the target to do.
2282 This can decay from a step to a continue, if e.g., we need to
2283 implement single-stepping with breakpoints (software
2287 gdb_assert (!tp
->stop_requested
);
2288 gdb_assert (!thread_is_in_step_over_chain (tp
));
2290 if (tp
->suspend
.waitstatus_pending_p
)
2295 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2297 fprintf_unfiltered (gdb_stdlog
,
2298 "infrun: resume: thread %s has pending wait "
2299 "status %s (currently_stepping=%d).\n",
2300 target_pid_to_str (tp
->ptid
).c_str (),
2302 currently_stepping (tp
));
2305 tp
->inf
->process_target ()->threads_executing
= true;
2308 /* FIXME: What should we do if we are supposed to resume this
2309 thread with a signal? Maybe we should maintain a queue of
2310 pending signals to deliver. */
2311 if (sig
!= GDB_SIGNAL_0
)
2313 warning (_("Couldn't deliver signal %s to %s."),
2314 gdb_signal_to_name (sig
),
2315 target_pid_to_str (tp
->ptid
).c_str ());
2318 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2320 if (target_can_async_p ())
2323 /* Tell the event loop we have an event to process. */
2324 mark_async_event_handler (infrun_async_inferior_event_token
);
2329 tp
->stepped_breakpoint
= 0;
2331 /* Depends on stepped_breakpoint. */
2332 step
= currently_stepping (tp
);
2334 if (current_inferior ()->waiting_for_vfork_done
)
2336 /* Don't try to single-step a vfork parent that is waiting for
2337 the child to get out of the shared memory region (by exec'ing
2338 or exiting). This is particularly important on software
2339 single-step archs, as the child process would trip on the
2340 software single step breakpoint inserted for the parent
2341 process. Since the parent will not actually execute any
2342 instruction until the child is out of the shared region (such
2343 are vfork's semantics), it is safe to simply continue it.
2344 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2345 the parent, and tell it to `keep_going', which automatically
2346 re-sets it stepping. */
2348 fprintf_unfiltered (gdb_stdlog
,
2349 "infrun: resume : clear step\n");
2354 fprintf_unfiltered (gdb_stdlog
,
2355 "infrun: resume (step=%d, signal=%s), "
2356 "trap_expected=%d, current thread [%s] at %s\n",
2357 step
, gdb_signal_to_symbol_string (sig
),
2358 tp
->control
.trap_expected
,
2359 target_pid_to_str (inferior_ptid
).c_str (),
2360 paddress (gdbarch
, pc
));
2362 /* Normally, by the time we reach `resume', the breakpoints are either
2363 removed or inserted, as appropriate. The exception is if we're sitting
2364 at a permanent breakpoint; we need to step over it, but permanent
2365 breakpoints can't be removed. So we have to test for it here. */
2366 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2368 if (sig
!= GDB_SIGNAL_0
)
2370 /* We have a signal to pass to the inferior. The resume
2371 may, or may not take us to the signal handler. If this
2372 is a step, we'll need to stop in the signal handler, if
2373 there's one, (if the target supports stepping into
2374 handlers), or in the next mainline instruction, if
2375 there's no handler. If this is a continue, we need to be
2376 sure to run the handler with all breakpoints inserted.
2377 In all cases, set a breakpoint at the current address
2378 (where the handler returns to), and once that breakpoint
2379 is hit, resume skipping the permanent breakpoint. If
2380 that breakpoint isn't hit, then we've stepped into the
2381 signal handler (or hit some other event). We'll delete
2382 the step-resume breakpoint then. */
2385 fprintf_unfiltered (gdb_stdlog
,
2386 "infrun: resume: skipping permanent breakpoint, "
2387 "deliver signal first\n");
2389 clear_step_over_info ();
2390 tp
->control
.trap_expected
= 0;
2392 if (tp
->control
.step_resume_breakpoint
== NULL
)
2394 /* Set a "high-priority" step-resume, as we don't want
2395 user breakpoints at PC to trigger (again) when this
2397 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2398 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2400 tp
->step_after_step_resume_breakpoint
= step
;
2403 insert_breakpoints ();
2407 /* There's no signal to pass, we can go ahead and skip the
2408 permanent breakpoint manually. */
2410 fprintf_unfiltered (gdb_stdlog
,
2411 "infrun: resume: skipping permanent breakpoint\n");
2412 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2413 /* Update pc to reflect the new address from which we will
2414 execute instructions. */
2415 pc
= regcache_read_pc (regcache
);
2419 /* We've already advanced the PC, so the stepping part
2420 is done. Now we need to arrange for a trap to be
2421 reported to handle_inferior_event. Set a breakpoint
2422 at the current PC, and run to it. Don't update
2423 prev_pc, because if we end in
2424 switch_back_to_stepped_thread, we want the "expected
2425 thread advanced also" branch to be taken. IOW, we
2426 don't want this thread to step further from PC
2428 gdb_assert (!step_over_info_valid_p ());
2429 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2430 insert_breakpoints ();
2432 resume_ptid
= internal_resume_ptid (user_step
);
2433 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2440 /* If we have a breakpoint to step over, make sure to do a single
2441 step only. Same if we have software watchpoints. */
2442 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2443 tp
->control
.may_range_step
= 0;
2445 /* If displaced stepping is enabled, step over breakpoints by executing a
2446 copy of the instruction at a different address.
2448 We can't use displaced stepping when we have a signal to deliver;
2449 the comments for displaced_step_prepare explain why. The
2450 comments in the handle_inferior event for dealing with 'random
2451 signals' explain what we do instead.
2453 We can't use displaced stepping when we are waiting for vfork_done
2454 event, displaced stepping breaks the vfork child similarly as single
2455 step software breakpoint. */
2456 if (tp
->control
.trap_expected
2457 && use_displaced_stepping (tp
)
2458 && !step_over_info_valid_p ()
2459 && sig
== GDB_SIGNAL_0
2460 && !current_inferior ()->waiting_for_vfork_done
)
2462 int prepared
= displaced_step_prepare (tp
);
2467 fprintf_unfiltered (gdb_stdlog
,
2468 "Got placed in step-over queue\n");
2470 tp
->control
.trap_expected
= 0;
2473 else if (prepared
< 0)
2475 /* Fallback to stepping over the breakpoint in-line. */
2477 if (target_is_non_stop_p ())
2478 stop_all_threads ();
2480 set_step_over_info (regcache
->aspace (),
2481 regcache_read_pc (regcache
), 0, tp
->global_num
);
2483 step
= maybe_software_singlestep (gdbarch
, pc
);
2485 insert_breakpoints ();
2487 else if (prepared
> 0)
2489 struct displaced_step_inferior_state
*displaced
;
2491 /* Update pc to reflect the new address from which we will
2492 execute instructions due to displaced stepping. */
2493 pc
= regcache_read_pc (get_thread_regcache (tp
));
2495 displaced
= get_displaced_stepping_state (tp
->inf
);
2496 step
= gdbarch_displaced_step_hw_singlestep
2497 (gdbarch
, displaced
->step_closure
.get ());
2501 /* Do we need to do it the hard way, w/temp breakpoints? */
2503 step
= maybe_software_singlestep (gdbarch
, pc
);
2505 /* Currently, our software single-step implementation leads to different
2506 results than hardware single-stepping in one situation: when stepping
2507 into delivering a signal which has an associated signal handler,
2508 hardware single-step will stop at the first instruction of the handler,
2509 while software single-step will simply skip execution of the handler.
2511 For now, this difference in behavior is accepted since there is no
2512 easy way to actually implement single-stepping into a signal handler
2513 without kernel support.
2515 However, there is one scenario where this difference leads to follow-on
2516 problems: if we're stepping off a breakpoint by removing all breakpoints
2517 and then single-stepping. In this case, the software single-step
2518 behavior means that even if there is a *breakpoint* in the signal
2519 handler, GDB still would not stop.
2521 Fortunately, we can at least fix this particular issue. We detect
2522 here the case where we are about to deliver a signal while software
2523 single-stepping with breakpoints removed. In this situation, we
2524 revert the decisions to remove all breakpoints and insert single-
2525 step breakpoints, and instead we install a step-resume breakpoint
2526 at the current address, deliver the signal without stepping, and
2527 once we arrive back at the step-resume breakpoint, actually step
2528 over the breakpoint we originally wanted to step over. */
2529 if (thread_has_single_step_breakpoints_set (tp
)
2530 && sig
!= GDB_SIGNAL_0
2531 && step_over_info_valid_p ())
2533 /* If we have nested signals or a pending signal is delivered
2534 immediately after a handler returns, might already have
2535 a step-resume breakpoint set on the earlier handler. We cannot
2536 set another step-resume breakpoint; just continue on until the
2537 original breakpoint is hit. */
2538 if (tp
->control
.step_resume_breakpoint
== NULL
)
2540 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2541 tp
->step_after_step_resume_breakpoint
= 1;
2544 delete_single_step_breakpoints (tp
);
2546 clear_step_over_info ();
2547 tp
->control
.trap_expected
= 0;
2549 insert_breakpoints ();
2552 /* If STEP is set, it's a request to use hardware stepping
2553 facilities. But in that case, we should never
2554 use singlestep breakpoint. */
2555 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2557 /* Decide the set of threads to ask the target to resume. */
2558 if (tp
->control
.trap_expected
)
2560 /* We're allowing a thread to run past a breakpoint it has
2561 hit, either by single-stepping the thread with the breakpoint
2562 removed, or by displaced stepping, with the breakpoint inserted.
2563 In the former case, we need to single-step only this thread,
2564 and keep others stopped, as they can miss this breakpoint if
2565 allowed to run. That's not really a problem for displaced
2566 stepping, but, we still keep other threads stopped, in case
2567 another thread is also stopped for a breakpoint waiting for
2568 its turn in the displaced stepping queue. */
2569 resume_ptid
= inferior_ptid
;
2572 resume_ptid
= internal_resume_ptid (user_step
);
2574 if (execution_direction
!= EXEC_REVERSE
2575 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2577 /* There are two cases where we currently need to step a
2578 breakpoint instruction when we have a signal to deliver:
2580 - See handle_signal_stop where we handle random signals that
2581 could take out us out of the stepping range. Normally, in
2582 that case we end up continuing (instead of stepping) over the
2583 signal handler with a breakpoint at PC, but there are cases
2584 where we should _always_ single-step, even if we have a
2585 step-resume breakpoint, like when a software watchpoint is
2586 set. Assuming single-stepping and delivering a signal at the
2587 same time would takes us to the signal handler, then we could
2588 have removed the breakpoint at PC to step over it. However,
2589 some hardware step targets (like e.g., Mac OS) can't step
2590 into signal handlers, and for those, we need to leave the
2591 breakpoint at PC inserted, as otherwise if the handler
2592 recurses and executes PC again, it'll miss the breakpoint.
2593 So we leave the breakpoint inserted anyway, but we need to
2594 record that we tried to step a breakpoint instruction, so
2595 that adjust_pc_after_break doesn't end up confused.
2597 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2598 in one thread after another thread that was stepping had been
2599 momentarily paused for a step-over. When we re-resume the
2600 stepping thread, it may be resumed from that address with a
2601 breakpoint that hasn't trapped yet. Seen with
2602 gdb.threads/non-stop-fair-events.exp, on targets that don't
2603 do displaced stepping. */
2606 fprintf_unfiltered (gdb_stdlog
,
2607 "infrun: resume: [%s] stepped breakpoint\n",
2608 target_pid_to_str (tp
->ptid
).c_str ());
2610 tp
->stepped_breakpoint
= 1;
2612 /* Most targets can step a breakpoint instruction, thus
2613 executing it normally. But if this one cannot, just
2614 continue and we will hit it anyway. */
2615 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2620 && tp
->control
.trap_expected
2621 && use_displaced_stepping (tp
)
2622 && !step_over_info_valid_p ())
2624 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2625 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2626 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2629 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2630 paddress (resume_gdbarch
, actual_pc
));
2631 read_memory (actual_pc
, buf
, sizeof (buf
));
2632 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2635 if (tp
->control
.may_range_step
)
2637 /* If we're resuming a thread with the PC out of the step
2638 range, then we're doing some nested/finer run control
2639 operation, like stepping the thread out of the dynamic
2640 linker or the displaced stepping scratch pad. We
2641 shouldn't have allowed a range step then. */
2642 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2645 do_target_resume (resume_ptid
, step
, sig
);
2649 /* Resume the inferior. SIG is the signal to give the inferior
2650 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2651 rolls back state on error. */
2654 resume (gdb_signal sig
)
2660 catch (const gdb_exception
&ex
)
2662 /* If resuming is being aborted for any reason, delete any
2663 single-step breakpoint resume_1 may have created, to avoid
2664 confusing the following resumption, and to avoid leaving
2665 single-step breakpoints perturbing other threads, in case
2666 we're running in non-stop mode. */
2667 if (inferior_ptid
!= null_ptid
)
2668 delete_single_step_breakpoints (inferior_thread ());
2678 /* Counter that tracks number of user visible stops. This can be used
2679 to tell whether a command has proceeded the inferior past the
2680 current location. This allows e.g., inferior function calls in
2681 breakpoint commands to not interrupt the command list. When the
2682 call finishes successfully, the inferior is standing at the same
2683 breakpoint as if nothing happened (and so we don't call
2685 static ULONGEST current_stop_id
;
2692 return current_stop_id
;
2695 /* Called when we report a user visible stop. */
2703 /* Clear out all variables saying what to do when inferior is continued.
2704 First do this, then set the ones you want, then call `proceed'. */
2707 clear_proceed_status_thread (struct thread_info
*tp
)
2710 fprintf_unfiltered (gdb_stdlog
,
2711 "infrun: clear_proceed_status_thread (%s)\n",
2712 target_pid_to_str (tp
->ptid
).c_str ());
2714 /* If we're starting a new sequence, then the previous finished
2715 single-step is no longer relevant. */
2716 if (tp
->suspend
.waitstatus_pending_p
)
2718 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2721 fprintf_unfiltered (gdb_stdlog
,
2722 "infrun: clear_proceed_status: pending "
2723 "event of %s was a finished step. "
2725 target_pid_to_str (tp
->ptid
).c_str ());
2727 tp
->suspend
.waitstatus_pending_p
= 0;
2728 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2730 else if (debug_infrun
)
2733 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2735 fprintf_unfiltered (gdb_stdlog
,
2736 "infrun: clear_proceed_status_thread: thread %s "
2737 "has pending wait status %s "
2738 "(currently_stepping=%d).\n",
2739 target_pid_to_str (tp
->ptid
).c_str (),
2741 currently_stepping (tp
));
2745 /* If this signal should not be seen by program, give it zero.
2746 Used for debugging signals. */
2747 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2748 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2750 delete tp
->thread_fsm
;
2751 tp
->thread_fsm
= NULL
;
2753 tp
->control
.trap_expected
= 0;
2754 tp
->control
.step_range_start
= 0;
2755 tp
->control
.step_range_end
= 0;
2756 tp
->control
.may_range_step
= 0;
2757 tp
->control
.step_frame_id
= null_frame_id
;
2758 tp
->control
.step_stack_frame_id
= null_frame_id
;
2759 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2760 tp
->control
.step_start_function
= NULL
;
2761 tp
->stop_requested
= 0;
2763 tp
->control
.stop_step
= 0;
2765 tp
->control
.proceed_to_finish
= 0;
2767 tp
->control
.stepping_command
= 0;
2769 /* Discard any remaining commands or status from previous stop. */
2770 bpstat_clear (&tp
->control
.stop_bpstat
);
2774 clear_proceed_status (int step
)
2776 /* With scheduler-locking replay, stop replaying other threads if we're
2777 not replaying the user-visible resume ptid.
2779 This is a convenience feature to not require the user to explicitly
2780 stop replaying the other threads. We're assuming that the user's
2781 intent is to resume tracing the recorded process. */
2782 if (!non_stop
&& scheduler_mode
== schedlock_replay
2783 && target_record_is_replaying (minus_one_ptid
)
2784 && !target_record_will_replay (user_visible_resume_ptid (step
),
2785 execution_direction
))
2786 target_record_stop_replaying ();
2788 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2790 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2791 process_stratum_target
*resume_target
2792 = user_visible_resume_target (resume_ptid
);
2794 /* In all-stop mode, delete the per-thread status of all threads
2795 we're about to resume, implicitly and explicitly. */
2796 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2797 clear_proceed_status_thread (tp
);
2800 if (inferior_ptid
!= null_ptid
)
2802 struct inferior
*inferior
;
2806 /* If in non-stop mode, only delete the per-thread status of
2807 the current thread. */
2808 clear_proceed_status_thread (inferior_thread ());
2811 inferior
= current_inferior ();
2812 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2815 gdb::observers::about_to_proceed
.notify ();
2818 /* Returns true if TP is still stopped at a breakpoint that needs
2819 stepping-over in order to make progress. If the breakpoint is gone
2820 meanwhile, we can skip the whole step-over dance. */
2823 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2825 if (tp
->stepping_over_breakpoint
)
2827 struct regcache
*regcache
= get_thread_regcache (tp
);
2829 if (breakpoint_here_p (regcache
->aspace (),
2830 regcache_read_pc (regcache
))
2831 == ordinary_breakpoint_here
)
2834 tp
->stepping_over_breakpoint
= 0;
2840 /* Check whether thread TP still needs to start a step-over in order
2841 to make progress when resumed. Returns an bitwise or of enum
2842 step_over_what bits, indicating what needs to be stepped over. */
2844 static step_over_what
2845 thread_still_needs_step_over (struct thread_info
*tp
)
2847 step_over_what what
= 0;
2849 if (thread_still_needs_step_over_bp (tp
))
2850 what
|= STEP_OVER_BREAKPOINT
;
2852 if (tp
->stepping_over_watchpoint
2853 && !target_have_steppable_watchpoint
)
2854 what
|= STEP_OVER_WATCHPOINT
;
2859 /* Returns true if scheduler locking applies. STEP indicates whether
2860 we're about to do a step/next-like command to a thread. */
2863 schedlock_applies (struct thread_info
*tp
)
2865 return (scheduler_mode
== schedlock_on
2866 || (scheduler_mode
== schedlock_step
2867 && tp
->control
.stepping_command
)
2868 || (scheduler_mode
== schedlock_replay
2869 && target_record_will_replay (minus_one_ptid
,
2870 execution_direction
)));
2873 /* Calls target_commit_resume on all targets. */
2876 commit_resume_all_targets ()
2878 scoped_restore_current_thread restore_thread
;
2880 /* Map between process_target and a representative inferior. This
2881 is to avoid committing a resume in the same target more than
2882 once. Resumptions must be idempotent, so this is an
2884 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2886 for (inferior
*inf
: all_non_exited_inferiors ())
2887 if (inf
->has_execution ())
2888 conn_inf
[inf
->process_target ()] = inf
;
2890 for (const auto &ci
: conn_inf
)
2892 inferior
*inf
= ci
.second
;
2893 switch_to_inferior_no_thread (inf
);
2894 target_commit_resume ();
2898 /* Check that all the targets we're about to resume are in non-stop
2899 mode. Ideally, we'd only care whether all targets support
2900 target-async, but we're not there yet. E.g., stop_all_threads
2901 doesn't know how to handle all-stop targets. Also, the remote
2902 protocol in all-stop mode is synchronous, irrespective of
2903 target-async, which means that things like a breakpoint re-set
2904 triggered by one target would try to read memory from all targets
2908 check_multi_target_resumption (process_stratum_target
*resume_target
)
2910 if (!non_stop
&& resume_target
== nullptr)
2912 scoped_restore_current_thread restore_thread
;
2914 /* This is used to track whether we're resuming more than one
2916 process_stratum_target
*first_connection
= nullptr;
2918 /* The first inferior we see with a target that does not work in
2919 always-non-stop mode. */
2920 inferior
*first_not_non_stop
= nullptr;
2922 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2924 switch_to_inferior_no_thread (inf
);
2926 if (!target_has_execution
)
2929 process_stratum_target
*proc_target
2930 = current_inferior ()->process_target();
2932 if (!target_is_non_stop_p ())
2933 first_not_non_stop
= inf
;
2935 if (first_connection
== nullptr)
2936 first_connection
= proc_target
;
2937 else if (first_connection
!= proc_target
2938 && first_not_non_stop
!= nullptr)
2940 switch_to_inferior_no_thread (first_not_non_stop
);
2942 proc_target
= current_inferior ()->process_target();
2944 error (_("Connection %d (%s) does not support "
2945 "multi-target resumption."),
2946 proc_target
->connection_number
,
2947 make_target_connection_string (proc_target
).c_str ());
2953 /* Basic routine for continuing the program in various fashions.
2955 ADDR is the address to resume at, or -1 for resume where stopped.
2956 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2957 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2959 You should call clear_proceed_status before calling proceed. */
2962 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2964 struct regcache
*regcache
;
2965 struct gdbarch
*gdbarch
;
2967 struct execution_control_state ecss
;
2968 struct execution_control_state
*ecs
= &ecss
;
2971 /* If we're stopped at a fork/vfork, follow the branch set by the
2972 "set follow-fork-mode" command; otherwise, we'll just proceed
2973 resuming the current thread. */
2974 if (!follow_fork ())
2976 /* The target for some reason decided not to resume. */
2978 if (target_can_async_p ())
2979 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2983 /* We'll update this if & when we switch to a new thread. */
2984 previous_inferior_ptid
= inferior_ptid
;
2986 regcache
= get_current_regcache ();
2987 gdbarch
= regcache
->arch ();
2988 const address_space
*aspace
= regcache
->aspace ();
2990 pc
= regcache_read_pc (regcache
);
2991 thread_info
*cur_thr
= inferior_thread ();
2993 /* Fill in with reasonable starting values. */
2994 init_thread_stepping_state (cur_thr
);
2996 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2999 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
3000 process_stratum_target
*resume_target
3001 = user_visible_resume_target (resume_ptid
);
3003 check_multi_target_resumption (resume_target
);
3005 if (addr
== (CORE_ADDR
) -1)
3007 if (pc
== cur_thr
->suspend
.stop_pc
3008 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3009 && execution_direction
!= EXEC_REVERSE
)
3010 /* There is a breakpoint at the address we will resume at,
3011 step one instruction before inserting breakpoints so that
3012 we do not stop right away (and report a second hit at this
3015 Note, we don't do this in reverse, because we won't
3016 actually be executing the breakpoint insn anyway.
3017 We'll be (un-)executing the previous instruction. */
3018 cur_thr
->stepping_over_breakpoint
= 1;
3019 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3020 && gdbarch_single_step_through_delay (gdbarch
,
3021 get_current_frame ()))
3022 /* We stepped onto an instruction that needs to be stepped
3023 again before re-inserting the breakpoint, do so. */
3024 cur_thr
->stepping_over_breakpoint
= 1;
3028 regcache_write_pc (regcache
, addr
);
3031 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3032 cur_thr
->suspend
.stop_signal
= siggnal
;
3034 /* If an exception is thrown from this point on, make sure to
3035 propagate GDB's knowledge of the executing state to the
3036 frontend/user running state. */
3037 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3039 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3040 threads (e.g., we might need to set threads stepping over
3041 breakpoints first), from the user/frontend's point of view, all
3042 threads in RESUME_PTID are now running. Unless we're calling an
3043 inferior function, as in that case we pretend the inferior
3044 doesn't run at all. */
3045 if (!cur_thr
->control
.in_infcall
)
3046 set_running (resume_target
, resume_ptid
, true);
3049 fprintf_unfiltered (gdb_stdlog
,
3050 "infrun: proceed (addr=%s, signal=%s)\n",
3051 paddress (gdbarch
, addr
),
3052 gdb_signal_to_symbol_string (siggnal
));
3054 annotate_starting ();
3056 /* Make sure that output from GDB appears before output from the
3058 gdb_flush (gdb_stdout
);
3060 /* Since we've marked the inferior running, give it the terminal. A
3061 QUIT/Ctrl-C from here on is forwarded to the target (which can
3062 still detect attempts to unblock a stuck connection with repeated
3063 Ctrl-C from within target_pass_ctrlc). */
3064 target_terminal::inferior ();
3066 /* In a multi-threaded task we may select another thread and
3067 then continue or step.
3069 But if a thread that we're resuming had stopped at a breakpoint,
3070 it will immediately cause another breakpoint stop without any
3071 execution (i.e. it will report a breakpoint hit incorrectly). So
3072 we must step over it first.
3074 Look for threads other than the current (TP) that reported a
3075 breakpoint hit and haven't been resumed yet since. */
3077 /* If scheduler locking applies, we can avoid iterating over all
3079 if (!non_stop
&& !schedlock_applies (cur_thr
))
3081 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3084 switch_to_thread_no_regs (tp
);
3086 /* Ignore the current thread here. It's handled
3091 if (!thread_still_needs_step_over (tp
))
3094 gdb_assert (!thread_is_in_step_over_chain (tp
));
3097 fprintf_unfiltered (gdb_stdlog
,
3098 "infrun: need to step-over [%s] first\n",
3099 target_pid_to_str (tp
->ptid
).c_str ());
3101 thread_step_over_chain_enqueue (tp
);
3104 switch_to_thread (cur_thr
);
3107 /* Enqueue the current thread last, so that we move all other
3108 threads over their breakpoints first. */
3109 if (cur_thr
->stepping_over_breakpoint
)
3110 thread_step_over_chain_enqueue (cur_thr
);
3112 /* If the thread isn't started, we'll still need to set its prev_pc,
3113 so that switch_back_to_stepped_thread knows the thread hasn't
3114 advanced. Must do this before resuming any thread, as in
3115 all-stop/remote, once we resume we can't send any other packet
3116 until the target stops again. */
3117 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
3120 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3122 started
= start_step_over ();
3124 if (step_over_info_valid_p ())
3126 /* Either this thread started a new in-line step over, or some
3127 other thread was already doing one. In either case, don't
3128 resume anything else until the step-over is finished. */
3130 else if (started
&& !target_is_non_stop_p ())
3132 /* A new displaced stepping sequence was started. In all-stop,
3133 we can't talk to the target anymore until it next stops. */
3135 else if (!non_stop
&& target_is_non_stop_p ())
3137 /* In all-stop, but the target is always in non-stop mode.
3138 Start all other threads that are implicitly resumed too. */
3139 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3142 switch_to_thread_no_regs (tp
);
3144 if (!tp
->inf
->has_execution ())
3147 fprintf_unfiltered (gdb_stdlog
,
3148 "infrun: proceed: [%s] target has "
3150 target_pid_to_str (tp
->ptid
).c_str ());
3157 fprintf_unfiltered (gdb_stdlog
,
3158 "infrun: proceed: [%s] resumed\n",
3159 target_pid_to_str (tp
->ptid
).c_str ());
3160 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3164 if (thread_is_in_step_over_chain (tp
))
3167 fprintf_unfiltered (gdb_stdlog
,
3168 "infrun: proceed: [%s] needs step-over\n",
3169 target_pid_to_str (tp
->ptid
).c_str ());
3174 fprintf_unfiltered (gdb_stdlog
,
3175 "infrun: proceed: resuming %s\n",
3176 target_pid_to_str (tp
->ptid
).c_str ());
3178 reset_ecs (ecs
, tp
);
3179 switch_to_thread (tp
);
3180 keep_going_pass_signal (ecs
);
3181 if (!ecs
->wait_some_more
)
3182 error (_("Command aborted."));
3185 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3187 /* The thread wasn't started, and isn't queued, run it now. */
3188 reset_ecs (ecs
, cur_thr
);
3189 switch_to_thread (cur_thr
);
3190 keep_going_pass_signal (ecs
);
3191 if (!ecs
->wait_some_more
)
3192 error (_("Command aborted."));
3196 commit_resume_all_targets ();
3198 finish_state
.release ();
3200 /* If we've switched threads above, switch back to the previously
3201 current thread. We don't want the user to see a different
3203 switch_to_thread (cur_thr
);
3205 /* Tell the event loop to wait for it to stop. If the target
3206 supports asynchronous execution, it'll do this from within
3208 if (!target_can_async_p ())
3209 mark_async_event_handler (infrun_async_inferior_event_token
);
3213 /* Start remote-debugging of a machine over a serial link. */
3216 start_remote (int from_tty
)
3218 inferior
*inf
= current_inferior ();
3219 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3221 /* Always go on waiting for the target, regardless of the mode. */
3222 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3223 indicate to wait_for_inferior that a target should timeout if
3224 nothing is returned (instead of just blocking). Because of this,
3225 targets expecting an immediate response need to, internally, set
3226 things up so that the target_wait() is forced to eventually
3228 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3229 differentiate to its caller what the state of the target is after
3230 the initial open has been performed. Here we're assuming that
3231 the target has stopped. It should be possible to eventually have
3232 target_open() return to the caller an indication that the target
3233 is currently running and GDB state should be set to the same as
3234 for an async run. */
3235 wait_for_inferior (inf
);
3237 /* Now that the inferior has stopped, do any bookkeeping like
3238 loading shared libraries. We want to do this before normal_stop,
3239 so that the displayed frame is up to date. */
3240 post_create_inferior (current_top_target (), from_tty
);
3245 /* Initialize static vars when a new inferior begins. */
3248 init_wait_for_inferior (void)
3250 /* These are meaningless until the first time through wait_for_inferior. */
3252 breakpoint_init_inferior (inf_starting
);
3254 clear_proceed_status (0);
3256 nullify_last_target_wait_ptid ();
3258 previous_inferior_ptid
= inferior_ptid
;
3263 static void handle_inferior_event (struct execution_control_state
*ecs
);
3265 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3266 struct execution_control_state
*ecs
);
3267 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3268 struct execution_control_state
*ecs
);
3269 static void handle_signal_stop (struct execution_control_state
*ecs
);
3270 static void check_exception_resume (struct execution_control_state
*,
3271 struct frame_info
*);
3273 static void end_stepping_range (struct execution_control_state
*ecs
);
3274 static void stop_waiting (struct execution_control_state
*ecs
);
3275 static void keep_going (struct execution_control_state
*ecs
);
3276 static void process_event_stop_test (struct execution_control_state
*ecs
);
3277 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3279 /* This function is attached as a "thread_stop_requested" observer.
3280 Cleanup local state that assumed the PTID was to be resumed, and
3281 report the stop to the frontend. */
3284 infrun_thread_stop_requested (ptid_t ptid
)
3286 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3288 /* PTID was requested to stop. If the thread was already stopped,
3289 but the user/frontend doesn't know about that yet (e.g., the
3290 thread had been temporarily paused for some step-over), set up
3291 for reporting the stop now. */
3292 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3294 if (tp
->state
!= THREAD_RUNNING
)
3299 /* Remove matching threads from the step-over queue, so
3300 start_step_over doesn't try to resume them
3302 if (thread_is_in_step_over_chain (tp
))
3303 thread_step_over_chain_remove (tp
);
3305 /* If the thread is stopped, but the user/frontend doesn't
3306 know about that yet, queue a pending event, as if the
3307 thread had just stopped now. Unless the thread already had
3309 if (!tp
->suspend
.waitstatus_pending_p
)
3311 tp
->suspend
.waitstatus_pending_p
= 1;
3312 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3313 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3316 /* Clear the inline-frame state, since we're re-processing the
3318 clear_inline_frame_state (tp
);
3320 /* If this thread was paused because some other thread was
3321 doing an inline-step over, let that finish first. Once
3322 that happens, we'll restart all threads and consume pending
3323 stop events then. */
3324 if (step_over_info_valid_p ())
3327 /* Otherwise we can process the (new) pending event now. Set
3328 it so this pending event is considered by
3335 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3337 if (target_last_proc_target
== tp
->inf
->process_target ()
3338 && target_last_wait_ptid
== tp
->ptid
)
3339 nullify_last_target_wait_ptid ();
3342 /* Delete the step resume, single-step and longjmp/exception resume
3343 breakpoints of TP. */
3346 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3348 delete_step_resume_breakpoint (tp
);
3349 delete_exception_resume_breakpoint (tp
);
3350 delete_single_step_breakpoints (tp
);
3353 /* If the target still has execution, call FUNC for each thread that
3354 just stopped. In all-stop, that's all the non-exited threads; in
3355 non-stop, that's the current thread, only. */
3357 typedef void (*for_each_just_stopped_thread_callback_func
)
3358 (struct thread_info
*tp
);
3361 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3363 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3366 if (target_is_non_stop_p ())
3368 /* If in non-stop mode, only the current thread stopped. */
3369 func (inferior_thread ());
3373 /* In all-stop mode, all threads have stopped. */
3374 for (thread_info
*tp
: all_non_exited_threads ())
3379 /* Delete the step resume and longjmp/exception resume breakpoints of
3380 the threads that just stopped. */
3383 delete_just_stopped_threads_infrun_breakpoints (void)
3385 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3388 /* Delete the single-step breakpoints of the threads that just
3392 delete_just_stopped_threads_single_step_breakpoints (void)
3394 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3400 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3401 const struct target_waitstatus
*ws
)
3403 std::string status_string
= target_waitstatus_to_string (ws
);
3406 /* The text is split over several lines because it was getting too long.
3407 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3408 output as a unit; we want only one timestamp printed if debug_timestamp
3411 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3414 waiton_ptid
.tid ());
3415 if (waiton_ptid
.pid () != -1)
3416 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3417 stb
.printf (", status) =\n");
3418 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3422 target_pid_to_str (result_ptid
).c_str ());
3423 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3425 /* This uses %s in part to handle %'s in the text, but also to avoid
3426 a gcc error: the format attribute requires a string literal. */
3427 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3430 /* Select a thread at random, out of those which are resumed and have
3433 static struct thread_info
*
3434 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3438 auto has_event
= [&] (thread_info
*tp
)
3440 return (tp
->ptid
.matches (waiton_ptid
)
3442 && tp
->suspend
.waitstatus_pending_p
);
3445 /* First see how many events we have. Count only resumed threads
3446 that have an event pending. */
3447 for (thread_info
*tp
: inf
->non_exited_threads ())
3451 if (num_events
== 0)
3454 /* Now randomly pick a thread out of those that have had events. */
3455 int random_selector
= (int) ((num_events
* (double) rand ())
3456 / (RAND_MAX
+ 1.0));
3458 if (debug_infrun
&& num_events
> 1)
3459 fprintf_unfiltered (gdb_stdlog
,
3460 "infrun: Found %d events, selecting #%d\n",
3461 num_events
, random_selector
);
3463 /* Select the Nth thread that has had an event. */
3464 for (thread_info
*tp
: inf
->non_exited_threads ())
3466 if (random_selector
-- == 0)
3469 gdb_assert_not_reached ("event thread not found");
3472 /* Wrapper for target_wait that first checks whether threads have
3473 pending statuses to report before actually asking the target for
3474 more events. INF is the inferior we're using to call target_wait
3478 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3479 target_waitstatus
*status
, int options
)
3482 struct thread_info
*tp
;
3484 /* We know that we are looking for an event in the target of inferior
3485 INF, but we don't know which thread the event might come from. As
3486 such we want to make sure that INFERIOR_PTID is reset so that none of
3487 the wait code relies on it - doing so is always a mistake. */
3488 switch_to_inferior_no_thread (inf
);
3490 /* First check if there is a resumed thread with a wait status
3492 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3494 tp
= random_pending_event_thread (inf
, ptid
);
3499 fprintf_unfiltered (gdb_stdlog
,
3500 "infrun: Waiting for specific thread %s.\n",
3501 target_pid_to_str (ptid
).c_str ());
3503 /* We have a specific thread to check. */
3504 tp
= find_thread_ptid (inf
, ptid
);
3505 gdb_assert (tp
!= NULL
);
3506 if (!tp
->suspend
.waitstatus_pending_p
)
3511 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3512 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3514 struct regcache
*regcache
= get_thread_regcache (tp
);
3515 struct gdbarch
*gdbarch
= regcache
->arch ();
3519 pc
= regcache_read_pc (regcache
);
3521 if (pc
!= tp
->suspend
.stop_pc
)
3524 fprintf_unfiltered (gdb_stdlog
,
3525 "infrun: PC of %s changed. was=%s, now=%s\n",
3526 target_pid_to_str (tp
->ptid
).c_str (),
3527 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3528 paddress (gdbarch
, pc
));
3531 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3534 fprintf_unfiltered (gdb_stdlog
,
3535 "infrun: previous breakpoint of %s, at %s gone\n",
3536 target_pid_to_str (tp
->ptid
).c_str (),
3537 paddress (gdbarch
, pc
));
3545 fprintf_unfiltered (gdb_stdlog
,
3546 "infrun: pending event of %s cancelled.\n",
3547 target_pid_to_str (tp
->ptid
).c_str ());
3549 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3550 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3559 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3561 fprintf_unfiltered (gdb_stdlog
,
3562 "infrun: Using pending wait status %s for %s.\n",
3564 target_pid_to_str (tp
->ptid
).c_str ());
3567 /* Now that we've selected our final event LWP, un-adjust its PC
3568 if it was a software breakpoint (and the target doesn't
3569 always adjust the PC itself). */
3570 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3571 && !target_supports_stopped_by_sw_breakpoint ())
3573 struct regcache
*regcache
;
3574 struct gdbarch
*gdbarch
;
3577 regcache
= get_thread_regcache (tp
);
3578 gdbarch
= regcache
->arch ();
3580 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3585 pc
= regcache_read_pc (regcache
);
3586 regcache_write_pc (regcache
, pc
+ decr_pc
);
3590 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3591 *status
= tp
->suspend
.waitstatus
;
3592 tp
->suspend
.waitstatus_pending_p
= 0;
3594 /* Wake up the event loop again, until all pending events are
3596 if (target_is_async_p ())
3597 mark_async_event_handler (infrun_async_inferior_event_token
);
3601 /* But if we don't find one, we'll have to wait. */
3603 if (deprecated_target_wait_hook
)
3604 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3606 event_ptid
= target_wait (ptid
, status
, options
);
3611 /* Returns true if INF has any resumed thread with a status
3615 threads_are_resumed_pending_p (inferior
*inf
)
3617 for (thread_info
*tp
: inf
->non_exited_threads ())
3619 && tp
->suspend
.waitstatus_pending_p
)
3625 /* Wrapper for target_wait that first checks whether threads have
3626 pending statuses to report before actually asking the target for
3627 more events. Polls for events from all inferiors/targets. */
3630 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3632 int num_inferiors
= 0;
3633 int random_selector
;
3635 /* For fairness, we pick the first inferior/target to poll at
3636 random, and then continue polling the rest of the inferior list
3637 starting from that one in a circular fashion until the whole list
3640 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3642 return (inf
->process_target () != NULL
3643 && (threads_are_executing (inf
->process_target ())
3644 || threads_are_resumed_pending_p (inf
))
3645 && ptid_t (inf
->pid
).matches (wait_ptid
));
3648 /* First see how many resumed inferiors we have. */
3649 for (inferior
*inf
: all_inferiors ())
3650 if (inferior_matches (inf
))
3653 if (num_inferiors
== 0)
3655 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3659 /* Now randomly pick an inferior out of those that were resumed. */
3660 random_selector
= (int)
3661 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3663 if (debug_infrun
&& num_inferiors
> 1)
3664 fprintf_unfiltered (gdb_stdlog
,
3665 "infrun: Found %d inferiors, starting at #%d\n",
3666 num_inferiors
, random_selector
);
3668 /* Select the Nth inferior that was resumed. */
3670 inferior
*selected
= nullptr;
3672 for (inferior
*inf
: all_inferiors ())
3673 if (inferior_matches (inf
))
3674 if (random_selector
-- == 0)
3680 /* Now poll for events out of each of the resumed inferior's
3681 targets, starting from the selected one. */
3683 auto do_wait
= [&] (inferior
*inf
)
3685 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3686 ecs
->target
= inf
->process_target ();
3687 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3690 /* Needed in all-stop+target-non-stop mode, because we end up here
3691 spuriously after the target is all stopped and we've already
3692 reported the stop to the user, polling for events. */
3693 scoped_restore_current_thread restore_thread
;
3695 int inf_num
= selected
->num
;
3696 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3697 if (inferior_matches (inf
))
3701 for (inferior
*inf
= inferior_list
;
3702 inf
!= NULL
&& inf
->num
< inf_num
;
3704 if (inferior_matches (inf
))
3708 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3712 /* Prepare and stabilize the inferior for detaching it. E.g.,
3713 detaching while a thread is displaced stepping is a recipe for
3714 crashing it, as nothing would readjust the PC out of the scratch
3718 prepare_for_detach (void)
3720 struct inferior
*inf
= current_inferior ();
3721 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3723 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3725 /* Is any thread of this process displaced stepping? If not,
3726 there's nothing else to do. */
3727 if (displaced
->step_thread
== nullptr)
3731 fprintf_unfiltered (gdb_stdlog
,
3732 "displaced-stepping in-process while detaching");
3734 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3736 while (displaced
->step_thread
!= nullptr)
3738 struct execution_control_state ecss
;
3739 struct execution_control_state
*ecs
;
3742 memset (ecs
, 0, sizeof (*ecs
));
3744 overlay_cache_invalid
= 1;
3745 /* Flush target cache before starting to handle each event.
3746 Target was running and cache could be stale. This is just a
3747 heuristic. Running threads may modify target memory, but we
3748 don't get any event. */
3749 target_dcache_invalidate ();
3751 do_target_wait (pid_ptid
, ecs
, 0);
3754 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3756 /* If an error happens while handling the event, propagate GDB's
3757 knowledge of the executing state to the frontend/user running
3759 scoped_finish_thread_state
finish_state (inf
->process_target (),
3762 /* Now figure out what to do with the result of the result. */
3763 handle_inferior_event (ecs
);
3765 /* No error, don't finish the state yet. */
3766 finish_state
.release ();
3768 /* Breakpoints and watchpoints are not installed on the target
3769 at this point, and signals are passed directly to the
3770 inferior, so this must mean the process is gone. */
3771 if (!ecs
->wait_some_more
)
3773 restore_detaching
.release ();
3774 error (_("Program exited while detaching"));
3778 restore_detaching
.release ();
3781 /* Wait for control to return from inferior to debugger.
3783 If inferior gets a signal, we may decide to start it up again
3784 instead of returning. That is why there is a loop in this function.
3785 When this function actually returns it means the inferior
3786 should be left stopped and GDB should read more commands. */
3789 wait_for_inferior (inferior
*inf
)
3793 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3795 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3797 /* If an error happens while handling the event, propagate GDB's
3798 knowledge of the executing state to the frontend/user running
3800 scoped_finish_thread_state finish_state
3801 (inf
->process_target (), minus_one_ptid
);
3805 struct execution_control_state ecss
;
3806 struct execution_control_state
*ecs
= &ecss
;
3808 memset (ecs
, 0, sizeof (*ecs
));
3810 overlay_cache_invalid
= 1;
3812 /* Flush target cache before starting to handle each event.
3813 Target was running and cache could be stale. This is just a
3814 heuristic. Running threads may modify target memory, but we
3815 don't get any event. */
3816 target_dcache_invalidate ();
3818 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3819 ecs
->target
= inf
->process_target ();
3822 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3824 /* Now figure out what to do with the result of the result. */
3825 handle_inferior_event (ecs
);
3827 if (!ecs
->wait_some_more
)
3831 /* No error, don't finish the state yet. */
3832 finish_state
.release ();
3835 /* Cleanup that reinstalls the readline callback handler, if the
3836 target is running in the background. If while handling the target
3837 event something triggered a secondary prompt, like e.g., a
3838 pagination prompt, we'll have removed the callback handler (see
3839 gdb_readline_wrapper_line). Need to do this as we go back to the
3840 event loop, ready to process further input. Note this has no
3841 effect if the handler hasn't actually been removed, because calling
3842 rl_callback_handler_install resets the line buffer, thus losing
3846 reinstall_readline_callback_handler_cleanup ()
3848 struct ui
*ui
= current_ui
;
3852 /* We're not going back to the top level event loop yet. Don't
3853 install the readline callback, as it'd prep the terminal,
3854 readline-style (raw, noecho) (e.g., --batch). We'll install
3855 it the next time the prompt is displayed, when we're ready
3860 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3861 gdb_rl_callback_handler_reinstall ();
3864 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3865 that's just the event thread. In all-stop, that's all threads. */
3868 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3870 if (ecs
->event_thread
!= NULL
3871 && ecs
->event_thread
->thread_fsm
!= NULL
)
3872 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3876 for (thread_info
*thr
: all_non_exited_threads ())
3878 if (thr
->thread_fsm
== NULL
)
3880 if (thr
== ecs
->event_thread
)
3883 switch_to_thread (thr
);
3884 thr
->thread_fsm
->clean_up (thr
);
3887 if (ecs
->event_thread
!= NULL
)
3888 switch_to_thread (ecs
->event_thread
);
3892 /* Helper for all_uis_check_sync_execution_done that works on the
3896 check_curr_ui_sync_execution_done (void)
3898 struct ui
*ui
= current_ui
;
3900 if (ui
->prompt_state
== PROMPT_NEEDED
3902 && !gdb_in_secondary_prompt_p (ui
))
3904 target_terminal::ours ();
3905 gdb::observers::sync_execution_done
.notify ();
3906 ui_register_input_event_handler (ui
);
3913 all_uis_check_sync_execution_done (void)
3915 SWITCH_THRU_ALL_UIS ()
3917 check_curr_ui_sync_execution_done ();
3924 all_uis_on_sync_execution_starting (void)
3926 SWITCH_THRU_ALL_UIS ()
3928 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3929 async_disable_stdin ();
3933 /* Asynchronous version of wait_for_inferior. It is called by the
3934 event loop whenever a change of state is detected on the file
3935 descriptor corresponding to the target. It can be called more than
3936 once to complete a single execution command. In such cases we need
3937 to keep the state in a global variable ECSS. If it is the last time
3938 that this function is called for a single execution command, then
3939 report to the user that the inferior has stopped, and do the
3940 necessary cleanups. */
3943 fetch_inferior_event (void *client_data
)
3945 struct execution_control_state ecss
;
3946 struct execution_control_state
*ecs
= &ecss
;
3949 memset (ecs
, 0, sizeof (*ecs
));
3951 /* Events are always processed with the main UI as current UI. This
3952 way, warnings, debug output, etc. are always consistently sent to
3953 the main console. */
3954 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3956 /* End up with readline processing input, if necessary. */
3958 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3960 /* We're handling a live event, so make sure we're doing live
3961 debugging. If we're looking at traceframes while the target is
3962 running, we're going to need to get back to that mode after
3963 handling the event. */
3964 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3967 maybe_restore_traceframe
.emplace ();
3968 set_current_traceframe (-1);
3971 /* The user/frontend should not notice a thread switch due to
3972 internal events. Make sure we revert to the user selected
3973 thread and frame after handling the event and running any
3974 breakpoint commands. */
3975 scoped_restore_current_thread restore_thread
;
3977 overlay_cache_invalid
= 1;
3978 /* Flush target cache before starting to handle each event. Target
3979 was running and cache could be stale. This is just a heuristic.
3980 Running threads may modify target memory, but we don't get any
3982 target_dcache_invalidate ();
3984 scoped_restore save_exec_dir
3985 = make_scoped_restore (&execution_direction
,
3986 target_execution_direction ());
3988 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3991 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3993 /* Switch to the target that generated the event, so we can do
3994 target calls. Any inferior bound to the target will do, so we
3995 just switch to the first we find. */
3996 for (inferior
*inf
: all_inferiors (ecs
->target
))
3998 switch_to_inferior_no_thread (inf
);
4003 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
4005 /* If an error happens while handling the event, propagate GDB's
4006 knowledge of the executing state to the frontend/user running
4008 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
4009 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
4011 /* Get executed before scoped_restore_current_thread above to apply
4012 still for the thread which has thrown the exception. */
4013 auto defer_bpstat_clear
4014 = make_scope_exit (bpstat_clear_actions
);
4015 auto defer_delete_threads
4016 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4018 /* Now figure out what to do with the result of the result. */
4019 handle_inferior_event (ecs
);
4021 if (!ecs
->wait_some_more
)
4023 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4024 int should_stop
= 1;
4025 struct thread_info
*thr
= ecs
->event_thread
;
4027 delete_just_stopped_threads_infrun_breakpoints ();
4031 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4033 if (thread_fsm
!= NULL
)
4034 should_stop
= thread_fsm
->should_stop (thr
);
4043 bool should_notify_stop
= true;
4046 clean_up_just_stopped_threads_fsms (ecs
);
4048 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4049 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4051 if (should_notify_stop
)
4053 /* We may not find an inferior if this was a process exit. */
4054 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4055 proceeded
= normal_stop ();
4060 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4064 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4065 previously selected thread is gone. We have two
4066 choices - switch to no thread selected, or restore the
4067 previously selected thread (now exited). We chose the
4068 later, just because that's what GDB used to do. After
4069 this, "info threads" says "The current thread <Thread
4070 ID 2> has terminated." instead of "No thread
4074 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4075 restore_thread
.dont_restore ();
4079 defer_delete_threads
.release ();
4080 defer_bpstat_clear
.release ();
4082 /* No error, don't finish the thread states yet. */
4083 finish_state
.release ();
4085 /* This scope is used to ensure that readline callbacks are
4086 reinstalled here. */
4089 /* If a UI was in sync execution mode, and now isn't, restore its
4090 prompt (a synchronous execution command has finished, and we're
4091 ready for input). */
4092 all_uis_check_sync_execution_done ();
4095 && exec_done_display_p
4096 && (inferior_ptid
== null_ptid
4097 || inferior_thread ()->state
!= THREAD_RUNNING
))
4098 printf_unfiltered (_("completed.\n"));
4104 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4105 struct symtab_and_line sal
)
4107 /* This can be removed once this function no longer implicitly relies on the
4108 inferior_ptid value. */
4109 gdb_assert (inferior_ptid
== tp
->ptid
);
4111 tp
->control
.step_frame_id
= get_frame_id (frame
);
4112 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4114 tp
->current_symtab
= sal
.symtab
;
4115 tp
->current_line
= sal
.line
;
4118 /* Clear context switchable stepping state. */
4121 init_thread_stepping_state (struct thread_info
*tss
)
4123 tss
->stepped_breakpoint
= 0;
4124 tss
->stepping_over_breakpoint
= 0;
4125 tss
->stepping_over_watchpoint
= 0;
4126 tss
->step_after_step_resume_breakpoint
= 0;
4132 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4133 target_waitstatus status
)
4135 target_last_proc_target
= target
;
4136 target_last_wait_ptid
= ptid
;
4137 target_last_waitstatus
= status
;
4143 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4144 target_waitstatus
*status
)
4146 if (target
!= nullptr)
4147 *target
= target_last_proc_target
;
4148 if (ptid
!= nullptr)
4149 *ptid
= target_last_wait_ptid
;
4150 if (status
!= nullptr)
4151 *status
= target_last_waitstatus
;
4157 nullify_last_target_wait_ptid (void)
4159 target_last_proc_target
= nullptr;
4160 target_last_wait_ptid
= minus_one_ptid
;
4161 target_last_waitstatus
= {};
4164 /* Switch thread contexts. */
4167 context_switch (execution_control_state
*ecs
)
4170 && ecs
->ptid
!= inferior_ptid
4171 && (inferior_ptid
== null_ptid
4172 || ecs
->event_thread
!= inferior_thread ()))
4174 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4175 target_pid_to_str (inferior_ptid
).c_str ());
4176 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4177 target_pid_to_str (ecs
->ptid
).c_str ());
4180 switch_to_thread (ecs
->event_thread
);
4183 /* If the target can't tell whether we've hit breakpoints
4184 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4185 check whether that could have been caused by a breakpoint. If so,
4186 adjust the PC, per gdbarch_decr_pc_after_break. */
4189 adjust_pc_after_break (struct thread_info
*thread
,
4190 struct target_waitstatus
*ws
)
4192 struct regcache
*regcache
;
4193 struct gdbarch
*gdbarch
;
4194 CORE_ADDR breakpoint_pc
, decr_pc
;
4196 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4197 we aren't, just return.
4199 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4200 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4201 implemented by software breakpoints should be handled through the normal
4204 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4205 different signals (SIGILL or SIGEMT for instance), but it is less
4206 clear where the PC is pointing afterwards. It may not match
4207 gdbarch_decr_pc_after_break. I don't know any specific target that
4208 generates these signals at breakpoints (the code has been in GDB since at
4209 least 1992) so I can not guess how to handle them here.
4211 In earlier versions of GDB, a target with
4212 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4213 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4214 target with both of these set in GDB history, and it seems unlikely to be
4215 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4217 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4220 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4223 /* In reverse execution, when a breakpoint is hit, the instruction
4224 under it has already been de-executed. The reported PC always
4225 points at the breakpoint address, so adjusting it further would
4226 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4229 B1 0x08000000 : INSN1
4230 B2 0x08000001 : INSN2
4232 PC -> 0x08000003 : INSN4
4234 Say you're stopped at 0x08000003 as above. Reverse continuing
4235 from that point should hit B2 as below. Reading the PC when the
4236 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4237 been de-executed already.
4239 B1 0x08000000 : INSN1
4240 B2 PC -> 0x08000001 : INSN2
4244 We can't apply the same logic as for forward execution, because
4245 we would wrongly adjust the PC to 0x08000000, since there's a
4246 breakpoint at PC - 1. We'd then report a hit on B1, although
4247 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4249 if (execution_direction
== EXEC_REVERSE
)
4252 /* If the target can tell whether the thread hit a SW breakpoint,
4253 trust it. Targets that can tell also adjust the PC
4255 if (target_supports_stopped_by_sw_breakpoint ())
4258 /* Note that relying on whether a breakpoint is planted in memory to
4259 determine this can fail. E.g,. the breakpoint could have been
4260 removed since. Or the thread could have been told to step an
4261 instruction the size of a breakpoint instruction, and only
4262 _after_ was a breakpoint inserted at its address. */
4264 /* If this target does not decrement the PC after breakpoints, then
4265 we have nothing to do. */
4266 regcache
= get_thread_regcache (thread
);
4267 gdbarch
= regcache
->arch ();
4269 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4273 const address_space
*aspace
= regcache
->aspace ();
4275 /* Find the location where (if we've hit a breakpoint) the
4276 breakpoint would be. */
4277 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4279 /* If the target can't tell whether a software breakpoint triggered,
4280 fallback to figuring it out based on breakpoints we think were
4281 inserted in the target, and on whether the thread was stepped or
4284 /* Check whether there actually is a software breakpoint inserted at
4287 If in non-stop mode, a race condition is possible where we've
4288 removed a breakpoint, but stop events for that breakpoint were
4289 already queued and arrive later. To suppress those spurious
4290 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4291 and retire them after a number of stop events are reported. Note
4292 this is an heuristic and can thus get confused. The real fix is
4293 to get the "stopped by SW BP and needs adjustment" info out of
4294 the target/kernel (and thus never reach here; see above). */
4295 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4296 || (target_is_non_stop_p ()
4297 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4299 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4301 if (record_full_is_used ())
4302 restore_operation_disable
.emplace
4303 (record_full_gdb_operation_disable_set ());
4305 /* When using hardware single-step, a SIGTRAP is reported for both
4306 a completed single-step and a software breakpoint. Need to
4307 differentiate between the two, as the latter needs adjusting
4308 but the former does not.
4310 The SIGTRAP can be due to a completed hardware single-step only if
4311 - we didn't insert software single-step breakpoints
4312 - this thread is currently being stepped
4314 If any of these events did not occur, we must have stopped due
4315 to hitting a software breakpoint, and have to back up to the
4318 As a special case, we could have hardware single-stepped a
4319 software breakpoint. In this case (prev_pc == breakpoint_pc),
4320 we also need to back up to the breakpoint address. */
4322 if (thread_has_single_step_breakpoints_set (thread
)
4323 || !currently_stepping (thread
)
4324 || (thread
->stepped_breakpoint
4325 && thread
->prev_pc
== breakpoint_pc
))
4326 regcache_write_pc (regcache
, breakpoint_pc
);
4331 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4333 for (frame
= get_prev_frame (frame
);
4335 frame
= get_prev_frame (frame
))
4337 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4339 if (get_frame_type (frame
) != INLINE_FRAME
)
4346 /* Look for an inline frame that is marked for skip.
4347 If PREV_FRAME is TRUE start at the previous frame,
4348 otherwise start at the current frame. Stop at the
4349 first non-inline frame, or at the frame where the
4353 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4355 struct frame_info
*frame
= get_current_frame ();
4358 frame
= get_prev_frame (frame
);
4360 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4362 const char *fn
= NULL
;
4363 symtab_and_line sal
;
4366 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4368 if (get_frame_type (frame
) != INLINE_FRAME
)
4371 sal
= find_frame_sal (frame
);
4372 sym
= get_frame_function (frame
);
4375 fn
= sym
->print_name ();
4378 && function_name_is_marked_for_skip (fn
, sal
))
4385 /* If the event thread has the stop requested flag set, pretend it
4386 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4390 handle_stop_requested (struct execution_control_state
*ecs
)
4392 if (ecs
->event_thread
->stop_requested
)
4394 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4395 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4396 handle_signal_stop (ecs
);
4402 /* Auxiliary function that handles syscall entry/return events.
4403 It returns 1 if the inferior should keep going (and GDB
4404 should ignore the event), or 0 if the event deserves to be
4408 handle_syscall_event (struct execution_control_state
*ecs
)
4410 struct regcache
*regcache
;
4413 context_switch (ecs
);
4415 regcache
= get_thread_regcache (ecs
->event_thread
);
4416 syscall_number
= ecs
->ws
.value
.syscall_number
;
4417 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4419 if (catch_syscall_enabled () > 0
4420 && catching_syscall_number (syscall_number
) > 0)
4423 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4426 ecs
->event_thread
->control
.stop_bpstat
4427 = bpstat_stop_status (regcache
->aspace (),
4428 ecs
->event_thread
->suspend
.stop_pc
,
4429 ecs
->event_thread
, &ecs
->ws
);
4431 if (handle_stop_requested (ecs
))
4434 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4436 /* Catchpoint hit. */
4441 if (handle_stop_requested (ecs
))
4444 /* If no catchpoint triggered for this, then keep going. */
4449 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4452 fill_in_stop_func (struct gdbarch
*gdbarch
,
4453 struct execution_control_state
*ecs
)
4455 if (!ecs
->stop_func_filled_in
)
4459 /* Don't care about return value; stop_func_start and stop_func_name
4460 will both be 0 if it doesn't work. */
4461 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4462 &ecs
->stop_func_name
,
4463 &ecs
->stop_func_start
,
4464 &ecs
->stop_func_end
,
4467 /* The call to find_pc_partial_function, above, will set
4468 stop_func_start and stop_func_end to the start and end
4469 of the range containing the stop pc. If this range
4470 contains the entry pc for the block (which is always the
4471 case for contiguous blocks), advance stop_func_start past
4472 the function's start offset and entrypoint. Note that
4473 stop_func_start is NOT advanced when in a range of a
4474 non-contiguous block that does not contain the entry pc. */
4475 if (block
!= nullptr
4476 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4477 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4479 ecs
->stop_func_start
4480 += gdbarch_deprecated_function_start_offset (gdbarch
);
4482 if (gdbarch_skip_entrypoint_p (gdbarch
))
4483 ecs
->stop_func_start
4484 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4487 ecs
->stop_func_filled_in
= 1;
4492 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4494 static enum stop_kind
4495 get_inferior_stop_soon (execution_control_state
*ecs
)
4497 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4499 gdb_assert (inf
!= NULL
);
4500 return inf
->control
.stop_soon
;
4503 /* Poll for one event out of the current target. Store the resulting
4504 waitstatus in WS, and return the event ptid. Does not block. */
4507 poll_one_curr_target (struct target_waitstatus
*ws
)
4511 overlay_cache_invalid
= 1;
4513 /* Flush target cache before starting to handle each event.
4514 Target was running and cache could be stale. This is just a
4515 heuristic. Running threads may modify target memory, but we
4516 don't get any event. */
4517 target_dcache_invalidate ();
4519 if (deprecated_target_wait_hook
)
4520 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4522 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4525 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4530 /* An event reported by wait_one. */
4532 struct wait_one_event
4534 /* The target the event came out of. */
4535 process_stratum_target
*target
;
4537 /* The PTID the event was for. */
4540 /* The waitstatus. */
4541 target_waitstatus ws
;
4544 /* Wait for one event out of any target. */
4546 static wait_one_event
4551 for (inferior
*inf
: all_inferiors ())
4553 process_stratum_target
*target
= inf
->process_target ();
4555 || !target
->is_async_p ()
4556 || !target
->threads_executing
)
4559 switch_to_inferior_no_thread (inf
);
4561 wait_one_event event
;
4562 event
.target
= target
;
4563 event
.ptid
= poll_one_curr_target (&event
.ws
);
4565 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4567 /* If nothing is resumed, remove the target from the
4571 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4575 /* Block waiting for some event. */
4582 for (inferior
*inf
: all_inferiors ())
4584 process_stratum_target
*target
= inf
->process_target ();
4586 || !target
->is_async_p ()
4587 || !target
->threads_executing
)
4590 int fd
= target
->async_wait_fd ();
4591 FD_SET (fd
, &readfds
);
4598 /* No waitable targets left. All must be stopped. */
4599 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4604 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4610 perror_with_name ("interruptible_select");
4615 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4616 instead of the current thread. */
4617 #define THREAD_STOPPED_BY(REASON) \
4619 thread_stopped_by_ ## REASON (ptid_t ptid) \
4621 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4622 inferior_ptid = ptid; \
4624 return target_stopped_by_ ## REASON (); \
4627 /* Generate thread_stopped_by_watchpoint. */
4628 THREAD_STOPPED_BY (watchpoint
)
4629 /* Generate thread_stopped_by_sw_breakpoint. */
4630 THREAD_STOPPED_BY (sw_breakpoint
)
4631 /* Generate thread_stopped_by_hw_breakpoint. */
4632 THREAD_STOPPED_BY (hw_breakpoint
)
4634 /* Save the thread's event and stop reason to process it later. */
4637 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4641 std::string statstr
= target_waitstatus_to_string (ws
);
4643 fprintf_unfiltered (gdb_stdlog
,
4644 "infrun: saving status %s for %d.%ld.%ld\n",
4651 /* Record for later. */
4652 tp
->suspend
.waitstatus
= *ws
;
4653 tp
->suspend
.waitstatus_pending_p
= 1;
4655 struct regcache
*regcache
= get_thread_regcache (tp
);
4656 const address_space
*aspace
= regcache
->aspace ();
4658 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4659 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4661 CORE_ADDR pc
= regcache_read_pc (regcache
);
4663 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4665 if (thread_stopped_by_watchpoint (tp
->ptid
))
4667 tp
->suspend
.stop_reason
4668 = TARGET_STOPPED_BY_WATCHPOINT
;
4670 else if (target_supports_stopped_by_sw_breakpoint ()
4671 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4673 tp
->suspend
.stop_reason
4674 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4676 else if (target_supports_stopped_by_hw_breakpoint ()
4677 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4679 tp
->suspend
.stop_reason
4680 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4682 else if (!target_supports_stopped_by_hw_breakpoint ()
4683 && hardware_breakpoint_inserted_here_p (aspace
,
4686 tp
->suspend
.stop_reason
4687 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4689 else if (!target_supports_stopped_by_sw_breakpoint ()
4690 && software_breakpoint_inserted_here_p (aspace
,
4693 tp
->suspend
.stop_reason
4694 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4696 else if (!thread_has_single_step_breakpoints_set (tp
)
4697 && currently_stepping (tp
))
4699 tp
->suspend
.stop_reason
4700 = TARGET_STOPPED_BY_SINGLE_STEP
;
4708 stop_all_threads (void)
4710 /* We may need multiple passes to discover all threads. */
4714 gdb_assert (exists_non_stop_target ());
4717 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4719 scoped_restore_current_thread restore_thread
;
4721 target_thread_events (1);
4722 SCOPE_EXIT
{ target_thread_events (0); };
4724 /* Request threads to stop, and then wait for the stops. Because
4725 threads we already know about can spawn more threads while we're
4726 trying to stop them, and we only learn about new threads when we
4727 update the thread list, do this in a loop, and keep iterating
4728 until two passes find no threads that need to be stopped. */
4729 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4732 fprintf_unfiltered (gdb_stdlog
,
4733 "infrun: stop_all_threads, pass=%d, "
4734 "iterations=%d\n", pass
, iterations
);
4739 update_thread_list ();
4741 /* Go through all threads looking for threads that we need
4742 to tell the target to stop. */
4743 for (thread_info
*t
: all_non_exited_threads ())
4745 /* For a single-target setting with an all-stop target,
4746 we would not even arrive here. For a multi-target
4747 setting, until GDB is able to handle a mixture of
4748 all-stop and non-stop targets, simply skip all-stop
4749 targets' threads. This should be fine due to the
4750 protection of 'check_multi_target_resumption'. */
4752 switch_to_thread_no_regs (t
);
4753 if (!target_is_non_stop_p ())
4758 /* If already stopping, don't request a stop again.
4759 We just haven't seen the notification yet. */
4760 if (!t
->stop_requested
)
4763 fprintf_unfiltered (gdb_stdlog
,
4764 "infrun: %s executing, "
4766 target_pid_to_str (t
->ptid
).c_str ());
4767 target_stop (t
->ptid
);
4768 t
->stop_requested
= 1;
4773 fprintf_unfiltered (gdb_stdlog
,
4774 "infrun: %s executing, "
4775 "already stopping\n",
4776 target_pid_to_str (t
->ptid
).c_str ());
4779 if (t
->stop_requested
)
4785 fprintf_unfiltered (gdb_stdlog
,
4786 "infrun: %s not executing\n",
4787 target_pid_to_str (t
->ptid
).c_str ());
4789 /* The thread may be not executing, but still be
4790 resumed with a pending status to process. */
4798 /* If we find new threads on the second iteration, restart
4799 over. We want to see two iterations in a row with all
4804 wait_one_event event
= wait_one ();
4808 fprintf_unfiltered (gdb_stdlog
,
4809 "infrun: stop_all_threads %s %s\n",
4810 target_waitstatus_to_string (&event
.ws
).c_str (),
4811 target_pid_to_str (event
.ptid
).c_str ());
4814 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4815 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4816 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4817 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4819 /* All resumed threads exited
4820 or one thread/process exited/signalled. */
4824 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4826 t
= add_thread (event
.target
, event
.ptid
);
4828 t
->stop_requested
= 0;
4831 t
->control
.may_range_step
= 0;
4833 /* This may be the first time we see the inferior report
4835 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4836 if (inf
->needs_setup
)
4838 switch_to_thread_no_regs (t
);
4842 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4843 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4845 /* We caught the event that we intended to catch, so
4846 there's no event pending. */
4847 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4848 t
->suspend
.waitstatus_pending_p
= 0;
4850 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4852 /* Add it back to the step-over queue. */
4855 fprintf_unfiltered (gdb_stdlog
,
4856 "infrun: displaced-step of %s "
4857 "canceled: adding back to the "
4858 "step-over queue\n",
4859 target_pid_to_str (t
->ptid
).c_str ());
4861 t
->control
.trap_expected
= 0;
4862 thread_step_over_chain_enqueue (t
);
4867 enum gdb_signal sig
;
4868 struct regcache
*regcache
;
4872 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4874 fprintf_unfiltered (gdb_stdlog
,
4875 "infrun: target_wait %s, saving "
4876 "status for %d.%ld.%ld\n",
4883 /* Record for later. */
4884 save_waitstatus (t
, &event
.ws
);
4886 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4887 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4889 if (displaced_step_fixup (t
, sig
) < 0)
4891 /* Add it back to the step-over queue. */
4892 t
->control
.trap_expected
= 0;
4893 thread_step_over_chain_enqueue (t
);
4896 regcache
= get_thread_regcache (t
);
4897 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4901 fprintf_unfiltered (gdb_stdlog
,
4902 "infrun: saved stop_pc=%s for %s "
4903 "(currently_stepping=%d)\n",
4904 paddress (target_gdbarch (),
4905 t
->suspend
.stop_pc
),
4906 target_pid_to_str (t
->ptid
).c_str (),
4907 currently_stepping (t
));
4915 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4918 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4921 handle_no_resumed (struct execution_control_state
*ecs
)
4923 if (target_can_async_p ())
4930 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4938 /* There were no unwaited-for children left in the target, but,
4939 we're not synchronously waiting for events either. Just
4943 fprintf_unfiltered (gdb_stdlog
,
4944 "infrun: TARGET_WAITKIND_NO_RESUMED "
4945 "(ignoring: bg)\n");
4946 prepare_to_wait (ecs
);
4951 /* Otherwise, if we were running a synchronous execution command, we
4952 may need to cancel it and give the user back the terminal.
4954 In non-stop mode, the target can't tell whether we've already
4955 consumed previous stop events, so it can end up sending us a
4956 no-resumed event like so:
4958 #0 - thread 1 is left stopped
4960 #1 - thread 2 is resumed and hits breakpoint
4961 -> TARGET_WAITKIND_STOPPED
4963 #2 - thread 3 is resumed and exits
4964 this is the last resumed thread, so
4965 -> TARGET_WAITKIND_NO_RESUMED
4967 #3 - gdb processes stop for thread 2 and decides to re-resume
4970 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4971 thread 2 is now resumed, so the event should be ignored.
4973 IOW, if the stop for thread 2 doesn't end a foreground command,
4974 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4975 event. But it could be that the event meant that thread 2 itself
4976 (or whatever other thread was the last resumed thread) exited.
4978 To address this we refresh the thread list and check whether we
4979 have resumed threads _now_. In the example above, this removes
4980 thread 3 from the thread list. If thread 2 was re-resumed, we
4981 ignore this event. If we find no thread resumed, then we cancel
4982 the synchronous command show "no unwaited-for " to the user. */
4983 update_thread_list ();
4985 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4987 if (thread
->executing
4988 || thread
->suspend
.waitstatus_pending_p
)
4990 /* There were no unwaited-for children left in the target at
4991 some point, but there are now. Just ignore. */
4993 fprintf_unfiltered (gdb_stdlog
,
4994 "infrun: TARGET_WAITKIND_NO_RESUMED "
4995 "(ignoring: found resumed)\n");
4996 prepare_to_wait (ecs
);
5001 /* Note however that we may find no resumed thread because the whole
5002 process exited meanwhile (thus updating the thread list results
5003 in an empty thread list). In this case we know we'll be getting
5004 a process exit event shortly. */
5005 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
5007 thread_info
*thread
= any_live_thread_of_inferior (inf
);
5011 fprintf_unfiltered (gdb_stdlog
,
5012 "infrun: TARGET_WAITKIND_NO_RESUMED "
5013 "(expect process exit)\n");
5014 prepare_to_wait (ecs
);
5019 /* Go ahead and report the event. */
5023 /* Given an execution control state that has been freshly filled in by
5024 an event from the inferior, figure out what it means and take
5027 The alternatives are:
5029 1) stop_waiting and return; to really stop and return to the
5032 2) keep_going and return; to wait for the next event (set
5033 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5037 handle_inferior_event (struct execution_control_state
*ecs
)
5039 /* Make sure that all temporary struct value objects that were
5040 created during the handling of the event get deleted at the
5042 scoped_value_mark free_values
;
5044 enum stop_kind stop_soon
;
5047 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5048 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5050 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5052 /* We had an event in the inferior, but we are not interested in
5053 handling it at this level. The lower layers have already
5054 done what needs to be done, if anything.
5056 One of the possible circumstances for this is when the
5057 inferior produces output for the console. The inferior has
5058 not stopped, and we are ignoring the event. Another possible
5059 circumstance is any event which the lower level knows will be
5060 reported multiple times without an intervening resume. */
5061 prepare_to_wait (ecs
);
5065 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5067 prepare_to_wait (ecs
);
5071 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5072 && handle_no_resumed (ecs
))
5075 /* Cache the last target/ptid/waitstatus. */
5076 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5078 /* Always clear state belonging to the previous time we stopped. */
5079 stop_stack_dummy
= STOP_NONE
;
5081 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5083 /* No unwaited-for children left. IOW, all resumed children
5085 stop_print_frame
= 0;
5090 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5091 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5093 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5094 /* If it's a new thread, add it to the thread database. */
5095 if (ecs
->event_thread
== NULL
)
5096 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5098 /* Disable range stepping. If the next step request could use a
5099 range, this will be end up re-enabled then. */
5100 ecs
->event_thread
->control
.may_range_step
= 0;
5103 /* Dependent on valid ECS->EVENT_THREAD. */
5104 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5106 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5107 reinit_frame_cache ();
5109 breakpoint_retire_moribund ();
5111 /* First, distinguish signals caused by the debugger from signals
5112 that have to do with the program's own actions. Note that
5113 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5114 on the operating system version. Here we detect when a SIGILL or
5115 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5116 something similar for SIGSEGV, since a SIGSEGV will be generated
5117 when we're trying to execute a breakpoint instruction on a
5118 non-executable stack. This happens for call dummy breakpoints
5119 for architectures like SPARC that place call dummies on the
5121 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5122 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5123 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5124 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5126 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5128 if (breakpoint_inserted_here_p (regcache
->aspace (),
5129 regcache_read_pc (regcache
)))
5132 fprintf_unfiltered (gdb_stdlog
,
5133 "infrun: Treating signal as SIGTRAP\n");
5134 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5138 /* Mark the non-executing threads accordingly. In all-stop, all
5139 threads of all processes are stopped when we get any event
5140 reported. In non-stop mode, only the event thread stops. */
5144 if (!target_is_non_stop_p ())
5145 mark_ptid
= minus_one_ptid
;
5146 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
5147 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5149 /* If we're handling a process exit in non-stop mode, even
5150 though threads haven't been deleted yet, one would think
5151 that there is nothing to do, as threads of the dead process
5152 will be soon deleted, and threads of any other process were
5153 left running. However, on some targets, threads survive a
5154 process exit event. E.g., for the "checkpoint" command,
5155 when the current checkpoint/fork exits, linux-fork.c
5156 automatically switches to another fork from within
5157 target_mourn_inferior, by associating the same
5158 inferior/thread to another fork. We haven't mourned yet at
5159 this point, but we must mark any threads left in the
5160 process as not-executing so that finish_thread_state marks
5161 them stopped (in the user's perspective) if/when we present
5162 the stop to the user. */
5163 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
5166 mark_ptid
= ecs
->ptid
;
5168 set_executing (ecs
->target
, mark_ptid
, false);
5170 /* Likewise the resumed flag. */
5171 set_resumed (ecs
->target
, mark_ptid
, false);
5174 switch (ecs
->ws
.kind
)
5176 case TARGET_WAITKIND_LOADED
:
5177 context_switch (ecs
);
5178 /* Ignore gracefully during startup of the inferior, as it might
5179 be the shell which has just loaded some objects, otherwise
5180 add the symbols for the newly loaded objects. Also ignore at
5181 the beginning of an attach or remote session; we will query
5182 the full list of libraries once the connection is
5185 stop_soon
= get_inferior_stop_soon (ecs
);
5186 if (stop_soon
== NO_STOP_QUIETLY
)
5188 struct regcache
*regcache
;
5190 regcache
= get_thread_regcache (ecs
->event_thread
);
5192 handle_solib_event ();
5194 ecs
->event_thread
->control
.stop_bpstat
5195 = bpstat_stop_status (regcache
->aspace (),
5196 ecs
->event_thread
->suspend
.stop_pc
,
5197 ecs
->event_thread
, &ecs
->ws
);
5199 if (handle_stop_requested (ecs
))
5202 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5204 /* A catchpoint triggered. */
5205 process_event_stop_test (ecs
);
5209 /* If requested, stop when the dynamic linker notifies
5210 gdb of events. This allows the user to get control
5211 and place breakpoints in initializer routines for
5212 dynamically loaded objects (among other things). */
5213 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5214 if (stop_on_solib_events
)
5216 /* Make sure we print "Stopped due to solib-event" in
5218 stop_print_frame
= 1;
5225 /* If we are skipping through a shell, or through shared library
5226 loading that we aren't interested in, resume the program. If
5227 we're running the program normally, also resume. */
5228 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5230 /* Loading of shared libraries might have changed breakpoint
5231 addresses. Make sure new breakpoints are inserted. */
5232 if (stop_soon
== NO_STOP_QUIETLY
)
5233 insert_breakpoints ();
5234 resume (GDB_SIGNAL_0
);
5235 prepare_to_wait (ecs
);
5239 /* But stop if we're attaching or setting up a remote
5241 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5242 || stop_soon
== STOP_QUIETLY_REMOTE
)
5245 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5250 internal_error (__FILE__
, __LINE__
,
5251 _("unhandled stop_soon: %d"), (int) stop_soon
);
5253 case TARGET_WAITKIND_SPURIOUS
:
5254 if (handle_stop_requested (ecs
))
5256 context_switch (ecs
);
5257 resume (GDB_SIGNAL_0
);
5258 prepare_to_wait (ecs
);
5261 case TARGET_WAITKIND_THREAD_CREATED
:
5262 if (handle_stop_requested (ecs
))
5264 context_switch (ecs
);
5265 if (!switch_back_to_stepped_thread (ecs
))
5269 case TARGET_WAITKIND_EXITED
:
5270 case TARGET_WAITKIND_SIGNALLED
:
5271 inferior_ptid
= ecs
->ptid
;
5272 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5273 set_current_program_space (current_inferior ()->pspace
);
5274 handle_vfork_child_exec_or_exit (0);
5275 target_terminal::ours (); /* Must do this before mourn anyway. */
5277 /* Clearing any previous state of convenience variables. */
5278 clear_exit_convenience_vars ();
5280 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5282 /* Record the exit code in the convenience variable $_exitcode, so
5283 that the user can inspect this again later. */
5284 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5285 (LONGEST
) ecs
->ws
.value
.integer
);
5287 /* Also record this in the inferior itself. */
5288 current_inferior ()->has_exit_code
= 1;
5289 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5291 /* Support the --return-child-result option. */
5292 return_child_result_value
= ecs
->ws
.value
.integer
;
5294 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5298 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5300 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5302 /* Set the value of the internal variable $_exitsignal,
5303 which holds the signal uncaught by the inferior. */
5304 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5305 gdbarch_gdb_signal_to_target (gdbarch
,
5306 ecs
->ws
.value
.sig
));
5310 /* We don't have access to the target's method used for
5311 converting between signal numbers (GDB's internal
5312 representation <-> target's representation).
5313 Therefore, we cannot do a good job at displaying this
5314 information to the user. It's better to just warn
5315 her about it (if infrun debugging is enabled), and
5318 fprintf_filtered (gdb_stdlog
, _("\
5319 Cannot fill $_exitsignal with the correct signal number.\n"));
5322 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5325 gdb_flush (gdb_stdout
);
5326 target_mourn_inferior (inferior_ptid
);
5327 stop_print_frame
= 0;
5331 case TARGET_WAITKIND_FORKED
:
5332 case TARGET_WAITKIND_VFORKED
:
5333 /* Check whether the inferior is displaced stepping. */
5335 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5336 struct gdbarch
*gdbarch
= regcache
->arch ();
5338 /* If checking displaced stepping is supported, and thread
5339 ecs->ptid is displaced stepping. */
5340 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5342 struct inferior
*parent_inf
5343 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5344 struct regcache
*child_regcache
;
5345 CORE_ADDR parent_pc
;
5347 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5349 struct displaced_step_inferior_state
*displaced
5350 = get_displaced_stepping_state (parent_inf
);
5352 /* Restore scratch pad for child process. */
5353 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5356 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5357 indicating that the displaced stepping of syscall instruction
5358 has been done. Perform cleanup for parent process here. Note
5359 that this operation also cleans up the child process for vfork,
5360 because their pages are shared. */
5361 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5362 /* Start a new step-over in another thread if there's one
5366 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5367 the child's PC is also within the scratchpad. Set the child's PC
5368 to the parent's PC value, which has already been fixed up.
5369 FIXME: we use the parent's aspace here, although we're touching
5370 the child, because the child hasn't been added to the inferior
5371 list yet at this point. */
5374 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5375 ecs
->ws
.value
.related_pid
,
5377 parent_inf
->aspace
);
5378 /* Read PC value of parent process. */
5379 parent_pc
= regcache_read_pc (regcache
);
5381 if (debug_displaced
)
5382 fprintf_unfiltered (gdb_stdlog
,
5383 "displaced: write child pc from %s to %s\n",
5385 regcache_read_pc (child_regcache
)),
5386 paddress (gdbarch
, parent_pc
));
5388 regcache_write_pc (child_regcache
, parent_pc
);
5392 context_switch (ecs
);
5394 /* Immediately detach breakpoints from the child before there's
5395 any chance of letting the user delete breakpoints from the
5396 breakpoint lists. If we don't do this early, it's easy to
5397 leave left over traps in the child, vis: "break foo; catch
5398 fork; c; <fork>; del; c; <child calls foo>". We only follow
5399 the fork on the last `continue', and by that time the
5400 breakpoint at "foo" is long gone from the breakpoint table.
5401 If we vforked, then we don't need to unpatch here, since both
5402 parent and child are sharing the same memory pages; we'll
5403 need to unpatch at follow/detach time instead to be certain
5404 that new breakpoints added between catchpoint hit time and
5405 vfork follow are detached. */
5406 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5408 /* This won't actually modify the breakpoint list, but will
5409 physically remove the breakpoints from the child. */
5410 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5413 delete_just_stopped_threads_single_step_breakpoints ();
5415 /* In case the event is caught by a catchpoint, remember that
5416 the event is to be followed at the next resume of the thread,
5417 and not immediately. */
5418 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5420 ecs
->event_thread
->suspend
.stop_pc
5421 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5423 ecs
->event_thread
->control
.stop_bpstat
5424 = bpstat_stop_status (get_current_regcache ()->aspace (),
5425 ecs
->event_thread
->suspend
.stop_pc
,
5426 ecs
->event_thread
, &ecs
->ws
);
5428 if (handle_stop_requested (ecs
))
5431 /* If no catchpoint triggered for this, then keep going. Note
5432 that we're interested in knowing the bpstat actually causes a
5433 stop, not just if it may explain the signal. Software
5434 watchpoints, for example, always appear in the bpstat. */
5435 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5438 = (follow_fork_mode_string
== follow_fork_mode_child
);
5440 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5442 process_stratum_target
*targ
5443 = ecs
->event_thread
->inf
->process_target ();
5445 bool should_resume
= follow_fork ();
5447 /* Note that one of these may be an invalid pointer,
5448 depending on detach_fork. */
5449 thread_info
*parent
= ecs
->event_thread
;
5451 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5453 /* At this point, the parent is marked running, and the
5454 child is marked stopped. */
5456 /* If not resuming the parent, mark it stopped. */
5457 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5458 parent
->set_running (false);
5460 /* If resuming the child, mark it running. */
5461 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5462 child
->set_running (true);
5464 /* In non-stop mode, also resume the other branch. */
5465 if (!detach_fork
&& (non_stop
5466 || (sched_multi
&& target_is_non_stop_p ())))
5469 switch_to_thread (parent
);
5471 switch_to_thread (child
);
5473 ecs
->event_thread
= inferior_thread ();
5474 ecs
->ptid
= inferior_ptid
;
5479 switch_to_thread (child
);
5481 switch_to_thread (parent
);
5483 ecs
->event_thread
= inferior_thread ();
5484 ecs
->ptid
= inferior_ptid
;
5492 process_event_stop_test (ecs
);
5495 case TARGET_WAITKIND_VFORK_DONE
:
5496 /* Done with the shared memory region. Re-insert breakpoints in
5497 the parent, and keep going. */
5499 context_switch (ecs
);
5501 current_inferior ()->waiting_for_vfork_done
= 0;
5502 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5504 if (handle_stop_requested (ecs
))
5507 /* This also takes care of reinserting breakpoints in the
5508 previously locked inferior. */
5512 case TARGET_WAITKIND_EXECD
:
5514 /* Note we can't read registers yet (the stop_pc), because we
5515 don't yet know the inferior's post-exec architecture.
5516 'stop_pc' is explicitly read below instead. */
5517 switch_to_thread_no_regs (ecs
->event_thread
);
5519 /* Do whatever is necessary to the parent branch of the vfork. */
5520 handle_vfork_child_exec_or_exit (1);
5522 /* This causes the eventpoints and symbol table to be reset.
5523 Must do this now, before trying to determine whether to
5525 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5527 /* In follow_exec we may have deleted the original thread and
5528 created a new one. Make sure that the event thread is the
5529 execd thread for that case (this is a nop otherwise). */
5530 ecs
->event_thread
= inferior_thread ();
5532 ecs
->event_thread
->suspend
.stop_pc
5533 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5535 ecs
->event_thread
->control
.stop_bpstat
5536 = bpstat_stop_status (get_current_regcache ()->aspace (),
5537 ecs
->event_thread
->suspend
.stop_pc
,
5538 ecs
->event_thread
, &ecs
->ws
);
5540 /* Note that this may be referenced from inside
5541 bpstat_stop_status above, through inferior_has_execd. */
5542 xfree (ecs
->ws
.value
.execd_pathname
);
5543 ecs
->ws
.value
.execd_pathname
= NULL
;
5545 if (handle_stop_requested (ecs
))
5548 /* If no catchpoint triggered for this, then keep going. */
5549 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5551 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5555 process_event_stop_test (ecs
);
5558 /* Be careful not to try to gather much state about a thread
5559 that's in a syscall. It's frequently a losing proposition. */
5560 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5561 /* Getting the current syscall number. */
5562 if (handle_syscall_event (ecs
) == 0)
5563 process_event_stop_test (ecs
);
5566 /* Before examining the threads further, step this thread to
5567 get it entirely out of the syscall. (We get notice of the
5568 event when the thread is just on the verge of exiting a
5569 syscall. Stepping one instruction seems to get it back
5571 case TARGET_WAITKIND_SYSCALL_RETURN
:
5572 if (handle_syscall_event (ecs
) == 0)
5573 process_event_stop_test (ecs
);
5576 case TARGET_WAITKIND_STOPPED
:
5577 handle_signal_stop (ecs
);
5580 case TARGET_WAITKIND_NO_HISTORY
:
5581 /* Reverse execution: target ran out of history info. */
5583 /* Switch to the stopped thread. */
5584 context_switch (ecs
);
5586 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5588 delete_just_stopped_threads_single_step_breakpoints ();
5589 ecs
->event_thread
->suspend
.stop_pc
5590 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5592 if (handle_stop_requested (ecs
))
5595 gdb::observers::no_history
.notify ();
5601 /* Restart threads back to what they were trying to do back when we
5602 paused them for an in-line step-over. The EVENT_THREAD thread is
5606 restart_threads (struct thread_info
*event_thread
)
5608 /* In case the instruction just stepped spawned a new thread. */
5609 update_thread_list ();
5611 for (thread_info
*tp
: all_non_exited_threads ())
5613 switch_to_thread_no_regs (tp
);
5615 if (tp
== event_thread
)
5618 fprintf_unfiltered (gdb_stdlog
,
5619 "infrun: restart threads: "
5620 "[%s] is event thread\n",
5621 target_pid_to_str (tp
->ptid
).c_str ());
5625 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5628 fprintf_unfiltered (gdb_stdlog
,
5629 "infrun: restart threads: "
5630 "[%s] not meant to be running\n",
5631 target_pid_to_str (tp
->ptid
).c_str ());
5638 fprintf_unfiltered (gdb_stdlog
,
5639 "infrun: restart threads: [%s] resumed\n",
5640 target_pid_to_str (tp
->ptid
).c_str ());
5641 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5645 if (thread_is_in_step_over_chain (tp
))
5648 fprintf_unfiltered (gdb_stdlog
,
5649 "infrun: restart threads: "
5650 "[%s] needs step-over\n",
5651 target_pid_to_str (tp
->ptid
).c_str ());
5652 gdb_assert (!tp
->resumed
);
5657 if (tp
->suspend
.waitstatus_pending_p
)
5660 fprintf_unfiltered (gdb_stdlog
,
5661 "infrun: restart threads: "
5662 "[%s] has pending status\n",
5663 target_pid_to_str (tp
->ptid
).c_str ());
5668 gdb_assert (!tp
->stop_requested
);
5670 /* If some thread needs to start a step-over at this point, it
5671 should still be in the step-over queue, and thus skipped
5673 if (thread_still_needs_step_over (tp
))
5675 internal_error (__FILE__
, __LINE__
,
5676 "thread [%s] needs a step-over, but not in "
5677 "step-over queue\n",
5678 target_pid_to_str (tp
->ptid
).c_str ());
5681 if (currently_stepping (tp
))
5684 fprintf_unfiltered (gdb_stdlog
,
5685 "infrun: restart threads: [%s] was stepping\n",
5686 target_pid_to_str (tp
->ptid
).c_str ());
5687 keep_going_stepped_thread (tp
);
5691 struct execution_control_state ecss
;
5692 struct execution_control_state
*ecs
= &ecss
;
5695 fprintf_unfiltered (gdb_stdlog
,
5696 "infrun: restart threads: [%s] continuing\n",
5697 target_pid_to_str (tp
->ptid
).c_str ());
5698 reset_ecs (ecs
, tp
);
5699 switch_to_thread (tp
);
5700 keep_going_pass_signal (ecs
);
5705 /* Callback for iterate_over_threads. Find a resumed thread that has
5706 a pending waitstatus. */
5709 resumed_thread_with_pending_status (struct thread_info
*tp
,
5713 && tp
->suspend
.waitstatus_pending_p
);
5716 /* Called when we get an event that may finish an in-line or
5717 out-of-line (displaced stepping) step-over started previously.
5718 Return true if the event is processed and we should go back to the
5719 event loop; false if the caller should continue processing the
5723 finish_step_over (struct execution_control_state
*ecs
)
5725 int had_step_over_info
;
5727 displaced_step_fixup (ecs
->event_thread
,
5728 ecs
->event_thread
->suspend
.stop_signal
);
5730 had_step_over_info
= step_over_info_valid_p ();
5732 if (had_step_over_info
)
5734 /* If we're stepping over a breakpoint with all threads locked,
5735 then only the thread that was stepped should be reporting
5737 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5739 clear_step_over_info ();
5742 if (!target_is_non_stop_p ())
5745 /* Start a new step-over in another thread if there's one that
5749 /* If we were stepping over a breakpoint before, and haven't started
5750 a new in-line step-over sequence, then restart all other threads
5751 (except the event thread). We can't do this in all-stop, as then
5752 e.g., we wouldn't be able to issue any other remote packet until
5753 these other threads stop. */
5754 if (had_step_over_info
&& !step_over_info_valid_p ())
5756 struct thread_info
*pending
;
5758 /* If we only have threads with pending statuses, the restart
5759 below won't restart any thread and so nothing re-inserts the
5760 breakpoint we just stepped over. But we need it inserted
5761 when we later process the pending events, otherwise if
5762 another thread has a pending event for this breakpoint too,
5763 we'd discard its event (because the breakpoint that
5764 originally caused the event was no longer inserted). */
5765 context_switch (ecs
);
5766 insert_breakpoints ();
5768 restart_threads (ecs
->event_thread
);
5770 /* If we have events pending, go through handle_inferior_event
5771 again, picking up a pending event at random. This avoids
5772 thread starvation. */
5774 /* But not if we just stepped over a watchpoint in order to let
5775 the instruction execute so we can evaluate its expression.
5776 The set of watchpoints that triggered is recorded in the
5777 breakpoint objects themselves (see bp->watchpoint_triggered).
5778 If we processed another event first, that other event could
5779 clobber this info. */
5780 if (ecs
->event_thread
->stepping_over_watchpoint
)
5783 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5785 if (pending
!= NULL
)
5787 struct thread_info
*tp
= ecs
->event_thread
;
5788 struct regcache
*regcache
;
5792 fprintf_unfiltered (gdb_stdlog
,
5793 "infrun: found resumed threads with "
5794 "pending events, saving status\n");
5797 gdb_assert (pending
!= tp
);
5799 /* Record the event thread's event for later. */
5800 save_waitstatus (tp
, &ecs
->ws
);
5801 /* This was cleared early, by handle_inferior_event. Set it
5802 so this pending event is considered by
5806 gdb_assert (!tp
->executing
);
5808 regcache
= get_thread_regcache (tp
);
5809 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5813 fprintf_unfiltered (gdb_stdlog
,
5814 "infrun: saved stop_pc=%s for %s "
5815 "(currently_stepping=%d)\n",
5816 paddress (target_gdbarch (),
5817 tp
->suspend
.stop_pc
),
5818 target_pid_to_str (tp
->ptid
).c_str (),
5819 currently_stepping (tp
));
5822 /* This in-line step-over finished; clear this so we won't
5823 start a new one. This is what handle_signal_stop would
5824 do, if we returned false. */
5825 tp
->stepping_over_breakpoint
= 0;
5827 /* Wake up the event loop again. */
5828 mark_async_event_handler (infrun_async_inferior_event_token
);
5830 prepare_to_wait (ecs
);
5838 /* Come here when the program has stopped with a signal. */
5841 handle_signal_stop (struct execution_control_state
*ecs
)
5843 struct frame_info
*frame
;
5844 struct gdbarch
*gdbarch
;
5845 int stopped_by_watchpoint
;
5846 enum stop_kind stop_soon
;
5849 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5851 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5853 /* Do we need to clean up the state of a thread that has
5854 completed a displaced single-step? (Doing so usually affects
5855 the PC, so do it here, before we set stop_pc.) */
5856 if (finish_step_over (ecs
))
5859 /* If we either finished a single-step or hit a breakpoint, but
5860 the user wanted this thread to be stopped, pretend we got a
5861 SIG0 (generic unsignaled stop). */
5862 if (ecs
->event_thread
->stop_requested
5863 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5864 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5866 ecs
->event_thread
->suspend
.stop_pc
5867 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5871 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5872 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5874 switch_to_thread (ecs
->event_thread
);
5876 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5877 paddress (reg_gdbarch
,
5878 ecs
->event_thread
->suspend
.stop_pc
));
5879 if (target_stopped_by_watchpoint ())
5883 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5885 if (target_stopped_data_address (current_top_target (), &addr
))
5886 fprintf_unfiltered (gdb_stdlog
,
5887 "infrun: stopped data address = %s\n",
5888 paddress (reg_gdbarch
, addr
));
5890 fprintf_unfiltered (gdb_stdlog
,
5891 "infrun: (no data address available)\n");
5895 /* This is originated from start_remote(), start_inferior() and
5896 shared libraries hook functions. */
5897 stop_soon
= get_inferior_stop_soon (ecs
);
5898 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5900 context_switch (ecs
);
5902 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5903 stop_print_frame
= 1;
5908 /* This originates from attach_command(). We need to overwrite
5909 the stop_signal here, because some kernels don't ignore a
5910 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5911 See more comments in inferior.h. On the other hand, if we
5912 get a non-SIGSTOP, report it to the user - assume the backend
5913 will handle the SIGSTOP if it should show up later.
5915 Also consider that the attach is complete when we see a
5916 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5917 target extended-remote report it instead of a SIGSTOP
5918 (e.g. gdbserver). We already rely on SIGTRAP being our
5919 signal, so this is no exception.
5921 Also consider that the attach is complete when we see a
5922 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5923 the target to stop all threads of the inferior, in case the
5924 low level attach operation doesn't stop them implicitly. If
5925 they weren't stopped implicitly, then the stub will report a
5926 GDB_SIGNAL_0, meaning: stopped for no particular reason
5927 other than GDB's request. */
5928 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5929 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5930 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5931 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5933 stop_print_frame
= 1;
5935 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5939 /* See if something interesting happened to the non-current thread. If
5940 so, then switch to that thread. */
5941 if (ecs
->ptid
!= inferior_ptid
)
5944 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5946 context_switch (ecs
);
5948 if (deprecated_context_hook
)
5949 deprecated_context_hook (ecs
->event_thread
->global_num
);
5952 /* At this point, get hold of the now-current thread's frame. */
5953 frame
= get_current_frame ();
5954 gdbarch
= get_frame_arch (frame
);
5956 /* Pull the single step breakpoints out of the target. */
5957 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5959 struct regcache
*regcache
;
5962 regcache
= get_thread_regcache (ecs
->event_thread
);
5963 const address_space
*aspace
= regcache
->aspace ();
5965 pc
= regcache_read_pc (regcache
);
5967 /* However, before doing so, if this single-step breakpoint was
5968 actually for another thread, set this thread up for moving
5970 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5973 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5977 fprintf_unfiltered (gdb_stdlog
,
5978 "infrun: [%s] hit another thread's "
5979 "single-step breakpoint\n",
5980 target_pid_to_str (ecs
->ptid
).c_str ());
5982 ecs
->hit_singlestep_breakpoint
= 1;
5989 fprintf_unfiltered (gdb_stdlog
,
5990 "infrun: [%s] hit its "
5991 "single-step breakpoint\n",
5992 target_pid_to_str (ecs
->ptid
).c_str ());
5996 delete_just_stopped_threads_single_step_breakpoints ();
5998 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5999 && ecs
->event_thread
->control
.trap_expected
6000 && ecs
->event_thread
->stepping_over_watchpoint
)
6001 stopped_by_watchpoint
= 0;
6003 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
6005 /* If necessary, step over this watchpoint. We'll be back to display
6007 if (stopped_by_watchpoint
6008 && (target_have_steppable_watchpoint
6009 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6011 /* At this point, we are stopped at an instruction which has
6012 attempted to write to a piece of memory under control of
6013 a watchpoint. The instruction hasn't actually executed
6014 yet. If we were to evaluate the watchpoint expression
6015 now, we would get the old value, and therefore no change
6016 would seem to have occurred.
6018 In order to make watchpoints work `right', we really need
6019 to complete the memory write, and then evaluate the
6020 watchpoint expression. We do this by single-stepping the
6023 It may not be necessary to disable the watchpoint to step over
6024 it. For example, the PA can (with some kernel cooperation)
6025 single step over a watchpoint without disabling the watchpoint.
6027 It is far more common to need to disable a watchpoint to step
6028 the inferior over it. If we have non-steppable watchpoints,
6029 we must disable the current watchpoint; it's simplest to
6030 disable all watchpoints.
6032 Any breakpoint at PC must also be stepped over -- if there's
6033 one, it will have already triggered before the watchpoint
6034 triggered, and we either already reported it to the user, or
6035 it didn't cause a stop and we called keep_going. In either
6036 case, if there was a breakpoint at PC, we must be trying to
6038 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6043 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6044 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6045 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6046 ecs
->event_thread
->control
.stop_step
= 0;
6047 stop_print_frame
= 1;
6048 stopped_by_random_signal
= 0;
6049 bpstat stop_chain
= NULL
;
6051 /* Hide inlined functions starting here, unless we just performed stepi or
6052 nexti. After stepi and nexti, always show the innermost frame (not any
6053 inline function call sites). */
6054 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6056 const address_space
*aspace
6057 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6059 /* skip_inline_frames is expensive, so we avoid it if we can
6060 determine that the address is one where functions cannot have
6061 been inlined. This improves performance with inferiors that
6062 load a lot of shared libraries, because the solib event
6063 breakpoint is defined as the address of a function (i.e. not
6064 inline). Note that we have to check the previous PC as well
6065 as the current one to catch cases when we have just
6066 single-stepped off a breakpoint prior to reinstating it.
6067 Note that we're assuming that the code we single-step to is
6068 not inline, but that's not definitive: there's nothing
6069 preventing the event breakpoint function from containing
6070 inlined code, and the single-step ending up there. If the
6071 user had set a breakpoint on that inlined code, the missing
6072 skip_inline_frames call would break things. Fortunately
6073 that's an extremely unlikely scenario. */
6074 if (!pc_at_non_inline_function (aspace
,
6075 ecs
->event_thread
->suspend
.stop_pc
,
6077 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6078 && ecs
->event_thread
->control
.trap_expected
6079 && pc_at_non_inline_function (aspace
,
6080 ecs
->event_thread
->prev_pc
,
6083 stop_chain
= build_bpstat_chain (aspace
,
6084 ecs
->event_thread
->suspend
.stop_pc
,
6086 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6088 /* Re-fetch current thread's frame in case that invalidated
6090 frame
= get_current_frame ();
6091 gdbarch
= get_frame_arch (frame
);
6095 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6096 && ecs
->event_thread
->control
.trap_expected
6097 && gdbarch_single_step_through_delay_p (gdbarch
)
6098 && currently_stepping (ecs
->event_thread
))
6100 /* We're trying to step off a breakpoint. Turns out that we're
6101 also on an instruction that needs to be stepped multiple
6102 times before it's been fully executing. E.g., architectures
6103 with a delay slot. It needs to be stepped twice, once for
6104 the instruction and once for the delay slot. */
6105 int step_through_delay
6106 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6108 if (debug_infrun
&& step_through_delay
)
6109 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6110 if (ecs
->event_thread
->control
.step_range_end
== 0
6111 && step_through_delay
)
6113 /* The user issued a continue when stopped at a breakpoint.
6114 Set up for another trap and get out of here. */
6115 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6119 else if (step_through_delay
)
6121 /* The user issued a step when stopped at a breakpoint.
6122 Maybe we should stop, maybe we should not - the delay
6123 slot *might* correspond to a line of source. In any
6124 case, don't decide that here, just set
6125 ecs->stepping_over_breakpoint, making sure we
6126 single-step again before breakpoints are re-inserted. */
6127 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6131 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6132 handles this event. */
6133 ecs
->event_thread
->control
.stop_bpstat
6134 = bpstat_stop_status (get_current_regcache ()->aspace (),
6135 ecs
->event_thread
->suspend
.stop_pc
,
6136 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6138 /* Following in case break condition called a
6140 stop_print_frame
= 1;
6142 /* This is where we handle "moribund" watchpoints. Unlike
6143 software breakpoints traps, hardware watchpoint traps are
6144 always distinguishable from random traps. If no high-level
6145 watchpoint is associated with the reported stop data address
6146 anymore, then the bpstat does not explain the signal ---
6147 simply make sure to ignore it if `stopped_by_watchpoint' is
6151 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6152 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6154 && stopped_by_watchpoint
)
6155 fprintf_unfiltered (gdb_stdlog
,
6156 "infrun: no user watchpoint explains "
6157 "watchpoint SIGTRAP, ignoring\n");
6159 /* NOTE: cagney/2003-03-29: These checks for a random signal
6160 at one stage in the past included checks for an inferior
6161 function call's call dummy's return breakpoint. The original
6162 comment, that went with the test, read:
6164 ``End of a stack dummy. Some systems (e.g. Sony news) give
6165 another signal besides SIGTRAP, so check here as well as
6168 If someone ever tries to get call dummys on a
6169 non-executable stack to work (where the target would stop
6170 with something like a SIGSEGV), then those tests might need
6171 to be re-instated. Given, however, that the tests were only
6172 enabled when momentary breakpoints were not being used, I
6173 suspect that it won't be the case.
6175 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6176 be necessary for call dummies on a non-executable stack on
6179 /* See if the breakpoints module can explain the signal. */
6181 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6182 ecs
->event_thread
->suspend
.stop_signal
);
6184 /* Maybe this was a trap for a software breakpoint that has since
6186 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6188 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6189 ecs
->event_thread
->suspend
.stop_pc
))
6191 struct regcache
*regcache
;
6194 /* Re-adjust PC to what the program would see if GDB was not
6196 regcache
= get_thread_regcache (ecs
->event_thread
);
6197 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6200 gdb::optional
<scoped_restore_tmpl
<int>>
6201 restore_operation_disable
;
6203 if (record_full_is_used ())
6204 restore_operation_disable
.emplace
6205 (record_full_gdb_operation_disable_set ());
6207 regcache_write_pc (regcache
,
6208 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6213 /* A delayed software breakpoint event. Ignore the trap. */
6215 fprintf_unfiltered (gdb_stdlog
,
6216 "infrun: delayed software breakpoint "
6217 "trap, ignoring\n");
6222 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6223 has since been removed. */
6224 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6226 /* A delayed hardware breakpoint event. Ignore the trap. */
6228 fprintf_unfiltered (gdb_stdlog
,
6229 "infrun: delayed hardware breakpoint/watchpoint "
6230 "trap, ignoring\n");
6234 /* If not, perhaps stepping/nexting can. */
6236 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6237 && currently_stepping (ecs
->event_thread
));
6239 /* Perhaps the thread hit a single-step breakpoint of _another_
6240 thread. Single-step breakpoints are transparent to the
6241 breakpoints module. */
6243 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6245 /* No? Perhaps we got a moribund watchpoint. */
6247 random_signal
= !stopped_by_watchpoint
;
6249 /* Always stop if the user explicitly requested this thread to
6251 if (ecs
->event_thread
->stop_requested
)
6255 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6258 /* For the program's own signals, act according to
6259 the signal handling tables. */
6263 /* Signal not for debugging purposes. */
6264 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6265 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6268 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6269 gdb_signal_to_symbol_string (stop_signal
));
6271 stopped_by_random_signal
= 1;
6273 /* Always stop on signals if we're either just gaining control
6274 of the program, or the user explicitly requested this thread
6275 to remain stopped. */
6276 if (stop_soon
!= NO_STOP_QUIETLY
6277 || ecs
->event_thread
->stop_requested
6279 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6285 /* Notify observers the signal has "handle print" set. Note we
6286 returned early above if stopping; normal_stop handles the
6287 printing in that case. */
6288 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6290 /* The signal table tells us to print about this signal. */
6291 target_terminal::ours_for_output ();
6292 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6293 target_terminal::inferior ();
6296 /* Clear the signal if it should not be passed. */
6297 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6298 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6300 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6301 && ecs
->event_thread
->control
.trap_expected
6302 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6304 /* We were just starting a new sequence, attempting to
6305 single-step off of a breakpoint and expecting a SIGTRAP.
6306 Instead this signal arrives. This signal will take us out
6307 of the stepping range so GDB needs to remember to, when
6308 the signal handler returns, resume stepping off that
6310 /* To simplify things, "continue" is forced to use the same
6311 code paths as single-step - set a breakpoint at the
6312 signal return address and then, once hit, step off that
6315 fprintf_unfiltered (gdb_stdlog
,
6316 "infrun: signal arrived while stepping over "
6319 insert_hp_step_resume_breakpoint_at_frame (frame
);
6320 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6321 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6322 ecs
->event_thread
->control
.trap_expected
= 0;
6324 /* If we were nexting/stepping some other thread, switch to
6325 it, so that we don't continue it, losing control. */
6326 if (!switch_back_to_stepped_thread (ecs
))
6331 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6332 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6334 || ecs
->event_thread
->control
.step_range_end
== 1)
6335 && frame_id_eq (get_stack_frame_id (frame
),
6336 ecs
->event_thread
->control
.step_stack_frame_id
)
6337 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6339 /* The inferior is about to take a signal that will take it
6340 out of the single step range. Set a breakpoint at the
6341 current PC (which is presumably where the signal handler
6342 will eventually return) and then allow the inferior to
6345 Note that this is only needed for a signal delivered
6346 while in the single-step range. Nested signals aren't a
6347 problem as they eventually all return. */
6349 fprintf_unfiltered (gdb_stdlog
,
6350 "infrun: signal may take us out of "
6351 "single-step range\n");
6353 clear_step_over_info ();
6354 insert_hp_step_resume_breakpoint_at_frame (frame
);
6355 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6356 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6357 ecs
->event_thread
->control
.trap_expected
= 0;
6362 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6363 when either there's a nested signal, or when there's a
6364 pending signal enabled just as the signal handler returns
6365 (leaving the inferior at the step-resume-breakpoint without
6366 actually executing it). Either way continue until the
6367 breakpoint is really hit. */
6369 if (!switch_back_to_stepped_thread (ecs
))
6372 fprintf_unfiltered (gdb_stdlog
,
6373 "infrun: random signal, keep going\n");
6380 process_event_stop_test (ecs
);
6383 /* Come here when we've got some debug event / signal we can explain
6384 (IOW, not a random signal), and test whether it should cause a
6385 stop, or whether we should resume the inferior (transparently).
6386 E.g., could be a breakpoint whose condition evaluates false; we
6387 could be still stepping within the line; etc. */
6390 process_event_stop_test (struct execution_control_state
*ecs
)
6392 struct symtab_and_line stop_pc_sal
;
6393 struct frame_info
*frame
;
6394 struct gdbarch
*gdbarch
;
6395 CORE_ADDR jmp_buf_pc
;
6396 struct bpstat_what what
;
6398 /* Handle cases caused by hitting a breakpoint. */
6400 frame
= get_current_frame ();
6401 gdbarch
= get_frame_arch (frame
);
6403 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6405 if (what
.call_dummy
)
6407 stop_stack_dummy
= what
.call_dummy
;
6410 /* A few breakpoint types have callbacks associated (e.g.,
6411 bp_jit_event). Run them now. */
6412 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6414 /* If we hit an internal event that triggers symbol changes, the
6415 current frame will be invalidated within bpstat_what (e.g., if we
6416 hit an internal solib event). Re-fetch it. */
6417 frame
= get_current_frame ();
6418 gdbarch
= get_frame_arch (frame
);
6420 switch (what
.main_action
)
6422 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6423 /* If we hit the breakpoint at longjmp while stepping, we
6424 install a momentary breakpoint at the target of the
6428 fprintf_unfiltered (gdb_stdlog
,
6429 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6431 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6433 if (what
.is_longjmp
)
6435 struct value
*arg_value
;
6437 /* If we set the longjmp breakpoint via a SystemTap probe,
6438 then use it to extract the arguments. The destination PC
6439 is the third argument to the probe. */
6440 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6443 jmp_buf_pc
= value_as_address (arg_value
);
6444 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6446 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6447 || !gdbarch_get_longjmp_target (gdbarch
,
6448 frame
, &jmp_buf_pc
))
6451 fprintf_unfiltered (gdb_stdlog
,
6452 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6453 "(!gdbarch_get_longjmp_target)\n");
6458 /* Insert a breakpoint at resume address. */
6459 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6462 check_exception_resume (ecs
, frame
);
6466 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6468 struct frame_info
*init_frame
;
6470 /* There are several cases to consider.
6472 1. The initiating frame no longer exists. In this case we
6473 must stop, because the exception or longjmp has gone too
6476 2. The initiating frame exists, and is the same as the
6477 current frame. We stop, because the exception or longjmp
6480 3. The initiating frame exists and is different from the
6481 current frame. This means the exception or longjmp has
6482 been caught beneath the initiating frame, so keep going.
6484 4. longjmp breakpoint has been placed just to protect
6485 against stale dummy frames and user is not interested in
6486 stopping around longjmps. */
6489 fprintf_unfiltered (gdb_stdlog
,
6490 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6492 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6494 delete_exception_resume_breakpoint (ecs
->event_thread
);
6496 if (what
.is_longjmp
)
6498 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6500 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6508 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6512 struct frame_id current_id
6513 = get_frame_id (get_current_frame ());
6514 if (frame_id_eq (current_id
,
6515 ecs
->event_thread
->initiating_frame
))
6517 /* Case 2. Fall through. */
6527 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6529 delete_step_resume_breakpoint (ecs
->event_thread
);
6531 end_stepping_range (ecs
);
6535 case BPSTAT_WHAT_SINGLE
:
6537 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6538 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6539 /* Still need to check other stuff, at least the case where we
6540 are stepping and step out of the right range. */
6543 case BPSTAT_WHAT_STEP_RESUME
:
6545 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6547 delete_step_resume_breakpoint (ecs
->event_thread
);
6548 if (ecs
->event_thread
->control
.proceed_to_finish
6549 && execution_direction
== EXEC_REVERSE
)
6551 struct thread_info
*tp
= ecs
->event_thread
;
6553 /* We are finishing a function in reverse, and just hit the
6554 step-resume breakpoint at the start address of the
6555 function, and we're almost there -- just need to back up
6556 by one more single-step, which should take us back to the
6558 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6562 fill_in_stop_func (gdbarch
, ecs
);
6563 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6564 && execution_direction
== EXEC_REVERSE
)
6566 /* We are stepping over a function call in reverse, and just
6567 hit the step-resume breakpoint at the start address of
6568 the function. Go back to single-stepping, which should
6569 take us back to the function call. */
6570 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6576 case BPSTAT_WHAT_STOP_NOISY
:
6578 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6579 stop_print_frame
= 1;
6581 /* Assume the thread stopped for a breapoint. We'll still check
6582 whether a/the breakpoint is there when the thread is next
6584 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6589 case BPSTAT_WHAT_STOP_SILENT
:
6591 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6592 stop_print_frame
= 0;
6594 /* Assume the thread stopped for a breapoint. We'll still check
6595 whether a/the breakpoint is there when the thread is next
6597 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6601 case BPSTAT_WHAT_HP_STEP_RESUME
:
6603 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6605 delete_step_resume_breakpoint (ecs
->event_thread
);
6606 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6608 /* Back when the step-resume breakpoint was inserted, we
6609 were trying to single-step off a breakpoint. Go back to
6611 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6612 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6618 case BPSTAT_WHAT_KEEP_CHECKING
:
6622 /* If we stepped a permanent breakpoint and we had a high priority
6623 step-resume breakpoint for the address we stepped, but we didn't
6624 hit it, then we must have stepped into the signal handler. The
6625 step-resume was only necessary to catch the case of _not_
6626 stepping into the handler, so delete it, and fall through to
6627 checking whether the step finished. */
6628 if (ecs
->event_thread
->stepped_breakpoint
)
6630 struct breakpoint
*sr_bp
6631 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6634 && sr_bp
->loc
->permanent
6635 && sr_bp
->type
== bp_hp_step_resume
6636 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6639 fprintf_unfiltered (gdb_stdlog
,
6640 "infrun: stepped permanent breakpoint, stopped in "
6642 delete_step_resume_breakpoint (ecs
->event_thread
);
6643 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6647 /* We come here if we hit a breakpoint but should not stop for it.
6648 Possibly we also were stepping and should stop for that. So fall
6649 through and test for stepping. But, if not stepping, do not
6652 /* In all-stop mode, if we're currently stepping but have stopped in
6653 some other thread, we need to switch back to the stepped thread. */
6654 if (switch_back_to_stepped_thread (ecs
))
6657 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6660 fprintf_unfiltered (gdb_stdlog
,
6661 "infrun: step-resume breakpoint is inserted\n");
6663 /* Having a step-resume breakpoint overrides anything
6664 else having to do with stepping commands until
6665 that breakpoint is reached. */
6670 if (ecs
->event_thread
->control
.step_range_end
== 0)
6673 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6674 /* Likewise if we aren't even stepping. */
6679 /* Re-fetch current thread's frame in case the code above caused
6680 the frame cache to be re-initialized, making our FRAME variable
6681 a dangling pointer. */
6682 frame
= get_current_frame ();
6683 gdbarch
= get_frame_arch (frame
);
6684 fill_in_stop_func (gdbarch
, ecs
);
6686 /* If stepping through a line, keep going if still within it.
6688 Note that step_range_end is the address of the first instruction
6689 beyond the step range, and NOT the address of the last instruction
6692 Note also that during reverse execution, we may be stepping
6693 through a function epilogue and therefore must detect when
6694 the current-frame changes in the middle of a line. */
6696 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6698 && (execution_direction
!= EXEC_REVERSE
6699 || frame_id_eq (get_frame_id (frame
),
6700 ecs
->event_thread
->control
.step_frame_id
)))
6704 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6705 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6706 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6708 /* Tentatively re-enable range stepping; `resume' disables it if
6709 necessary (e.g., if we're stepping over a breakpoint or we
6710 have software watchpoints). */
6711 ecs
->event_thread
->control
.may_range_step
= 1;
6713 /* When stepping backward, stop at beginning of line range
6714 (unless it's the function entry point, in which case
6715 keep going back to the call point). */
6716 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6717 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6718 && stop_pc
!= ecs
->stop_func_start
6719 && execution_direction
== EXEC_REVERSE
)
6720 end_stepping_range (ecs
);
6727 /* We stepped out of the stepping range. */
6729 /* If we are stepping at the source level and entered the runtime
6730 loader dynamic symbol resolution code...
6732 EXEC_FORWARD: we keep on single stepping until we exit the run
6733 time loader code and reach the callee's address.
6735 EXEC_REVERSE: we've already executed the callee (backward), and
6736 the runtime loader code is handled just like any other
6737 undebuggable function call. Now we need only keep stepping
6738 backward through the trampoline code, and that's handled further
6739 down, so there is nothing for us to do here. */
6741 if (execution_direction
!= EXEC_REVERSE
6742 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6743 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6745 CORE_ADDR pc_after_resolver
=
6746 gdbarch_skip_solib_resolver (gdbarch
,
6747 ecs
->event_thread
->suspend
.stop_pc
);
6750 fprintf_unfiltered (gdb_stdlog
,
6751 "infrun: stepped into dynsym resolve code\n");
6753 if (pc_after_resolver
)
6755 /* Set up a step-resume breakpoint at the address
6756 indicated by SKIP_SOLIB_RESOLVER. */
6757 symtab_and_line sr_sal
;
6758 sr_sal
.pc
= pc_after_resolver
;
6759 sr_sal
.pspace
= get_frame_program_space (frame
);
6761 insert_step_resume_breakpoint_at_sal (gdbarch
,
6762 sr_sal
, null_frame_id
);
6769 /* Step through an indirect branch thunk. */
6770 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6771 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6772 ecs
->event_thread
->suspend
.stop_pc
))
6775 fprintf_unfiltered (gdb_stdlog
,
6776 "infrun: stepped into indirect branch thunk\n");
6781 if (ecs
->event_thread
->control
.step_range_end
!= 1
6782 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6783 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6784 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6787 fprintf_unfiltered (gdb_stdlog
,
6788 "infrun: stepped into signal trampoline\n");
6789 /* The inferior, while doing a "step" or "next", has ended up in
6790 a signal trampoline (either by a signal being delivered or by
6791 the signal handler returning). Just single-step until the
6792 inferior leaves the trampoline (either by calling the handler
6798 /* If we're in the return path from a shared library trampoline,
6799 we want to proceed through the trampoline when stepping. */
6800 /* macro/2012-04-25: This needs to come before the subroutine
6801 call check below as on some targets return trampolines look
6802 like subroutine calls (MIPS16 return thunks). */
6803 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6804 ecs
->event_thread
->suspend
.stop_pc
,
6805 ecs
->stop_func_name
)
6806 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6808 /* Determine where this trampoline returns. */
6809 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6810 CORE_ADDR real_stop_pc
6811 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6814 fprintf_unfiltered (gdb_stdlog
,
6815 "infrun: stepped into solib return tramp\n");
6817 /* Only proceed through if we know where it's going. */
6820 /* And put the step-breakpoint there and go until there. */
6821 symtab_and_line sr_sal
;
6822 sr_sal
.pc
= real_stop_pc
;
6823 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6824 sr_sal
.pspace
= get_frame_program_space (frame
);
6826 /* Do not specify what the fp should be when we stop since
6827 on some machines the prologue is where the new fp value
6829 insert_step_resume_breakpoint_at_sal (gdbarch
,
6830 sr_sal
, null_frame_id
);
6832 /* Restart without fiddling with the step ranges or
6839 /* Check for subroutine calls. The check for the current frame
6840 equalling the step ID is not necessary - the check of the
6841 previous frame's ID is sufficient - but it is a common case and
6842 cheaper than checking the previous frame's ID.
6844 NOTE: frame_id_eq will never report two invalid frame IDs as
6845 being equal, so to get into this block, both the current and
6846 previous frame must have valid frame IDs. */
6847 /* The outer_frame_id check is a heuristic to detect stepping
6848 through startup code. If we step over an instruction which
6849 sets the stack pointer from an invalid value to a valid value,
6850 we may detect that as a subroutine call from the mythical
6851 "outermost" function. This could be fixed by marking
6852 outermost frames as !stack_p,code_p,special_p. Then the
6853 initial outermost frame, before sp was valid, would
6854 have code_addr == &_start. See the comment in frame_id_eq
6856 if (!frame_id_eq (get_stack_frame_id (frame
),
6857 ecs
->event_thread
->control
.step_stack_frame_id
)
6858 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6859 ecs
->event_thread
->control
.step_stack_frame_id
)
6860 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6862 || (ecs
->event_thread
->control
.step_start_function
6863 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6865 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6866 CORE_ADDR real_stop_pc
;
6869 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6871 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6873 /* I presume that step_over_calls is only 0 when we're
6874 supposed to be stepping at the assembly language level
6875 ("stepi"). Just stop. */
6876 /* And this works the same backward as frontward. MVS */
6877 end_stepping_range (ecs
);
6881 /* Reverse stepping through solib trampolines. */
6883 if (execution_direction
== EXEC_REVERSE
6884 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6885 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6886 || (ecs
->stop_func_start
== 0
6887 && in_solib_dynsym_resolve_code (stop_pc
))))
6889 /* Any solib trampoline code can be handled in reverse
6890 by simply continuing to single-step. We have already
6891 executed the solib function (backwards), and a few
6892 steps will take us back through the trampoline to the
6898 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6900 /* We're doing a "next".
6902 Normal (forward) execution: set a breakpoint at the
6903 callee's return address (the address at which the caller
6906 Reverse (backward) execution. set the step-resume
6907 breakpoint at the start of the function that we just
6908 stepped into (backwards), and continue to there. When we
6909 get there, we'll need to single-step back to the caller. */
6911 if (execution_direction
== EXEC_REVERSE
)
6913 /* If we're already at the start of the function, we've either
6914 just stepped backward into a single instruction function,
6915 or stepped back out of a signal handler to the first instruction
6916 of the function. Just keep going, which will single-step back
6918 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6920 /* Normal function call return (static or dynamic). */
6921 symtab_and_line sr_sal
;
6922 sr_sal
.pc
= ecs
->stop_func_start
;
6923 sr_sal
.pspace
= get_frame_program_space (frame
);
6924 insert_step_resume_breakpoint_at_sal (gdbarch
,
6925 sr_sal
, null_frame_id
);
6929 insert_step_resume_breakpoint_at_caller (frame
);
6935 /* If we are in a function call trampoline (a stub between the
6936 calling routine and the real function), locate the real
6937 function. That's what tells us (a) whether we want to step
6938 into it at all, and (b) what prologue we want to run to the
6939 end of, if we do step into it. */
6940 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6941 if (real_stop_pc
== 0)
6942 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6943 if (real_stop_pc
!= 0)
6944 ecs
->stop_func_start
= real_stop_pc
;
6946 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6948 symtab_and_line sr_sal
;
6949 sr_sal
.pc
= ecs
->stop_func_start
;
6950 sr_sal
.pspace
= get_frame_program_space (frame
);
6952 insert_step_resume_breakpoint_at_sal (gdbarch
,
6953 sr_sal
, null_frame_id
);
6958 /* If we have line number information for the function we are
6959 thinking of stepping into and the function isn't on the skip
6962 If there are several symtabs at that PC (e.g. with include
6963 files), just want to know whether *any* of them have line
6964 numbers. find_pc_line handles this. */
6966 struct symtab_and_line tmp_sal
;
6968 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6969 if (tmp_sal
.line
!= 0
6970 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6972 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6974 if (execution_direction
== EXEC_REVERSE
)
6975 handle_step_into_function_backward (gdbarch
, ecs
);
6977 handle_step_into_function (gdbarch
, ecs
);
6982 /* If we have no line number and the step-stop-if-no-debug is
6983 set, we stop the step so that the user has a chance to switch
6984 in assembly mode. */
6985 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6986 && step_stop_if_no_debug
)
6988 end_stepping_range (ecs
);
6992 if (execution_direction
== EXEC_REVERSE
)
6994 /* If we're already at the start of the function, we've either just
6995 stepped backward into a single instruction function without line
6996 number info, or stepped back out of a signal handler to the first
6997 instruction of the function without line number info. Just keep
6998 going, which will single-step back to the caller. */
6999 if (ecs
->stop_func_start
!= stop_pc
)
7001 /* Set a breakpoint at callee's start address.
7002 From there we can step once and be back in the caller. */
7003 symtab_and_line sr_sal
;
7004 sr_sal
.pc
= ecs
->stop_func_start
;
7005 sr_sal
.pspace
= get_frame_program_space (frame
);
7006 insert_step_resume_breakpoint_at_sal (gdbarch
,
7007 sr_sal
, null_frame_id
);
7011 /* Set a breakpoint at callee's return address (the address
7012 at which the caller will resume). */
7013 insert_step_resume_breakpoint_at_caller (frame
);
7019 /* Reverse stepping through solib trampolines. */
7021 if (execution_direction
== EXEC_REVERSE
7022 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7024 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7026 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7027 || (ecs
->stop_func_start
== 0
7028 && in_solib_dynsym_resolve_code (stop_pc
)))
7030 /* Any solib trampoline code can be handled in reverse
7031 by simply continuing to single-step. We have already
7032 executed the solib function (backwards), and a few
7033 steps will take us back through the trampoline to the
7038 else if (in_solib_dynsym_resolve_code (stop_pc
))
7040 /* Stepped backward into the solib dynsym resolver.
7041 Set a breakpoint at its start and continue, then
7042 one more step will take us out. */
7043 symtab_and_line sr_sal
;
7044 sr_sal
.pc
= ecs
->stop_func_start
;
7045 sr_sal
.pspace
= get_frame_program_space (frame
);
7046 insert_step_resume_breakpoint_at_sal (gdbarch
,
7047 sr_sal
, null_frame_id
);
7053 /* This always returns the sal for the inner-most frame when we are in a
7054 stack of inlined frames, even if GDB actually believes that it is in a
7055 more outer frame. This is checked for below by calls to
7056 inline_skipped_frames. */
7057 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7059 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7060 the trampoline processing logic, however, there are some trampolines
7061 that have no names, so we should do trampoline handling first. */
7062 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7063 && ecs
->stop_func_name
== NULL
7064 && stop_pc_sal
.line
== 0)
7067 fprintf_unfiltered (gdb_stdlog
,
7068 "infrun: stepped into undebuggable function\n");
7070 /* The inferior just stepped into, or returned to, an
7071 undebuggable function (where there is no debugging information
7072 and no line number corresponding to the address where the
7073 inferior stopped). Since we want to skip this kind of code,
7074 we keep going until the inferior returns from this
7075 function - unless the user has asked us not to (via
7076 set step-mode) or we no longer know how to get back
7077 to the call site. */
7078 if (step_stop_if_no_debug
7079 || !frame_id_p (frame_unwind_caller_id (frame
)))
7081 /* If we have no line number and the step-stop-if-no-debug
7082 is set, we stop the step so that the user has a chance to
7083 switch in assembly mode. */
7084 end_stepping_range (ecs
);
7089 /* Set a breakpoint at callee's return address (the address
7090 at which the caller will resume). */
7091 insert_step_resume_breakpoint_at_caller (frame
);
7097 if (ecs
->event_thread
->control
.step_range_end
== 1)
7099 /* It is stepi or nexti. We always want to stop stepping after
7102 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7103 end_stepping_range (ecs
);
7107 if (stop_pc_sal
.line
== 0)
7109 /* We have no line number information. That means to stop
7110 stepping (does this always happen right after one instruction,
7111 when we do "s" in a function with no line numbers,
7112 or can this happen as a result of a return or longjmp?). */
7114 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7115 end_stepping_range (ecs
);
7119 /* Look for "calls" to inlined functions, part one. If the inline
7120 frame machinery detected some skipped call sites, we have entered
7121 a new inline function. */
7123 if (frame_id_eq (get_frame_id (get_current_frame ()),
7124 ecs
->event_thread
->control
.step_frame_id
)
7125 && inline_skipped_frames (ecs
->event_thread
))
7128 fprintf_unfiltered (gdb_stdlog
,
7129 "infrun: stepped into inlined function\n");
7131 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7133 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7135 /* For "step", we're going to stop. But if the call site
7136 for this inlined function is on the same source line as
7137 we were previously stepping, go down into the function
7138 first. Otherwise stop at the call site. */
7140 if (call_sal
.line
== ecs
->event_thread
->current_line
7141 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7143 step_into_inline_frame (ecs
->event_thread
);
7144 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7151 end_stepping_range (ecs
);
7156 /* For "next", we should stop at the call site if it is on a
7157 different source line. Otherwise continue through the
7158 inlined function. */
7159 if (call_sal
.line
== ecs
->event_thread
->current_line
7160 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7163 end_stepping_range (ecs
);
7168 /* Look for "calls" to inlined functions, part two. If we are still
7169 in the same real function we were stepping through, but we have
7170 to go further up to find the exact frame ID, we are stepping
7171 through a more inlined call beyond its call site. */
7173 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7174 && !frame_id_eq (get_frame_id (get_current_frame ()),
7175 ecs
->event_thread
->control
.step_frame_id
)
7176 && stepped_in_from (get_current_frame (),
7177 ecs
->event_thread
->control
.step_frame_id
))
7180 fprintf_unfiltered (gdb_stdlog
,
7181 "infrun: stepping through inlined function\n");
7183 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7184 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7187 end_stepping_range (ecs
);
7191 bool refresh_step_info
= true;
7192 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7193 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7194 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7196 if (stop_pc_sal
.is_stmt
)
7198 /* We are at the start of a different line. So stop. Note that
7199 we don't stop if we step into the middle of a different line.
7200 That is said to make things like for (;;) statements work
7203 fprintf_unfiltered (gdb_stdlog
,
7204 "infrun: stepped to a different line\n");
7205 end_stepping_range (ecs
);
7208 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7209 ecs
->event_thread
->control
.step_frame_id
))
7211 /* We are at the start of a different line, however, this line is
7212 not marked as a statement, and we have not changed frame. We
7213 ignore this line table entry, and continue stepping forward,
7214 looking for a better place to stop. */
7215 refresh_step_info
= false;
7217 fprintf_unfiltered (gdb_stdlog
,
7218 "infrun: stepped to a different line, but "
7219 "it's not the start of a statement\n");
7223 /* We aren't done stepping.
7225 Optimize by setting the stepping range to the line.
7226 (We might not be in the original line, but if we entered a
7227 new line in mid-statement, we continue stepping. This makes
7228 things like for(;;) statements work better.)
7230 If we entered a SAL that indicates a non-statement line table entry,
7231 then we update the stepping range, but we don't update the step info,
7232 which includes things like the line number we are stepping away from.
7233 This means we will stop when we find a line table entry that is marked
7234 as is-statement, even if it matches the non-statement one we just
7237 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7238 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7239 ecs
->event_thread
->control
.may_range_step
= 1;
7240 if (refresh_step_info
)
7241 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7244 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7248 /* In all-stop mode, if we're currently stepping but have stopped in
7249 some other thread, we may need to switch back to the stepped
7250 thread. Returns true we set the inferior running, false if we left
7251 it stopped (and the event needs further processing). */
7254 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7256 if (!target_is_non_stop_p ())
7258 struct thread_info
*stepping_thread
;
7260 /* If any thread is blocked on some internal breakpoint, and we
7261 simply need to step over that breakpoint to get it going
7262 again, do that first. */
7264 /* However, if we see an event for the stepping thread, then we
7265 know all other threads have been moved past their breakpoints
7266 already. Let the caller check whether the step is finished,
7267 etc., before deciding to move it past a breakpoint. */
7268 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7271 /* Check if the current thread is blocked on an incomplete
7272 step-over, interrupted by a random signal. */
7273 if (ecs
->event_thread
->control
.trap_expected
7274 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7278 fprintf_unfiltered (gdb_stdlog
,
7279 "infrun: need to finish step-over of [%s]\n",
7280 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7286 /* Check if the current thread is blocked by a single-step
7287 breakpoint of another thread. */
7288 if (ecs
->hit_singlestep_breakpoint
)
7292 fprintf_unfiltered (gdb_stdlog
,
7293 "infrun: need to step [%s] over single-step "
7295 target_pid_to_str (ecs
->ptid
).c_str ());
7301 /* If this thread needs yet another step-over (e.g., stepping
7302 through a delay slot), do it first before moving on to
7304 if (thread_still_needs_step_over (ecs
->event_thread
))
7308 fprintf_unfiltered (gdb_stdlog
,
7309 "infrun: thread [%s] still needs step-over\n",
7310 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7316 /* If scheduler locking applies even if not stepping, there's no
7317 need to walk over threads. Above we've checked whether the
7318 current thread is stepping. If some other thread not the
7319 event thread is stepping, then it must be that scheduler
7320 locking is not in effect. */
7321 if (schedlock_applies (ecs
->event_thread
))
7324 /* Otherwise, we no longer expect a trap in the current thread.
7325 Clear the trap_expected flag before switching back -- this is
7326 what keep_going does as well, if we call it. */
7327 ecs
->event_thread
->control
.trap_expected
= 0;
7329 /* Likewise, clear the signal if it should not be passed. */
7330 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7331 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7333 /* Do all pending step-overs before actually proceeding with
7335 if (start_step_over ())
7337 prepare_to_wait (ecs
);
7341 /* Look for the stepping/nexting thread. */
7342 stepping_thread
= NULL
;
7344 for (thread_info
*tp
: all_non_exited_threads ())
7346 switch_to_thread_no_regs (tp
);
7348 /* Ignore threads of processes the caller is not
7351 && (tp
->inf
->process_target () != ecs
->target
7352 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7355 /* When stepping over a breakpoint, we lock all threads
7356 except the one that needs to move past the breakpoint.
7357 If a non-event thread has this set, the "incomplete
7358 step-over" check above should have caught it earlier. */
7359 if (tp
->control
.trap_expected
)
7361 internal_error (__FILE__
, __LINE__
,
7362 "[%s] has inconsistent state: "
7363 "trap_expected=%d\n",
7364 target_pid_to_str (tp
->ptid
).c_str (),
7365 tp
->control
.trap_expected
);
7368 /* Did we find the stepping thread? */
7369 if (tp
->control
.step_range_end
)
7371 /* Yep. There should only one though. */
7372 gdb_assert (stepping_thread
== NULL
);
7374 /* The event thread is handled at the top, before we
7376 gdb_assert (tp
!= ecs
->event_thread
);
7378 /* If some thread other than the event thread is
7379 stepping, then scheduler locking can't be in effect,
7380 otherwise we wouldn't have resumed the current event
7381 thread in the first place. */
7382 gdb_assert (!schedlock_applies (tp
));
7384 stepping_thread
= tp
;
7388 if (stepping_thread
!= NULL
)
7391 fprintf_unfiltered (gdb_stdlog
,
7392 "infrun: switching back to stepped thread\n");
7394 if (keep_going_stepped_thread (stepping_thread
))
7396 prepare_to_wait (ecs
);
7401 switch_to_thread (ecs
->event_thread
);
7407 /* Set a previously stepped thread back to stepping. Returns true on
7408 success, false if the resume is not possible (e.g., the thread
7412 keep_going_stepped_thread (struct thread_info
*tp
)
7414 struct frame_info
*frame
;
7415 struct execution_control_state ecss
;
7416 struct execution_control_state
*ecs
= &ecss
;
7418 /* If the stepping thread exited, then don't try to switch back and
7419 resume it, which could fail in several different ways depending
7420 on the target. Instead, just keep going.
7422 We can find a stepping dead thread in the thread list in two
7425 - The target supports thread exit events, and when the target
7426 tries to delete the thread from the thread list, inferior_ptid
7427 pointed at the exiting thread. In such case, calling
7428 delete_thread does not really remove the thread from the list;
7429 instead, the thread is left listed, with 'exited' state.
7431 - The target's debug interface does not support thread exit
7432 events, and so we have no idea whatsoever if the previously
7433 stepping thread is still alive. For that reason, we need to
7434 synchronously query the target now. */
7436 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7439 fprintf_unfiltered (gdb_stdlog
,
7440 "infrun: not resuming previously "
7441 "stepped thread, it has vanished\n");
7448 fprintf_unfiltered (gdb_stdlog
,
7449 "infrun: resuming previously stepped thread\n");
7451 reset_ecs (ecs
, tp
);
7452 switch_to_thread (tp
);
7454 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7455 frame
= get_current_frame ();
7457 /* If the PC of the thread we were trying to single-step has
7458 changed, then that thread has trapped or been signaled, but the
7459 event has not been reported to GDB yet. Re-poll the target
7460 looking for this particular thread's event (i.e. temporarily
7461 enable schedlock) by:
7463 - setting a break at the current PC
7464 - resuming that particular thread, only (by setting trap
7467 This prevents us continuously moving the single-step breakpoint
7468 forward, one instruction at a time, overstepping. */
7470 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7475 fprintf_unfiltered (gdb_stdlog
,
7476 "infrun: expected thread advanced also (%s -> %s)\n",
7477 paddress (target_gdbarch (), tp
->prev_pc
),
7478 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7480 /* Clear the info of the previous step-over, as it's no longer
7481 valid (if the thread was trying to step over a breakpoint, it
7482 has already succeeded). It's what keep_going would do too,
7483 if we called it. Do this before trying to insert the sss
7484 breakpoint, otherwise if we were previously trying to step
7485 over this exact address in another thread, the breakpoint is
7487 clear_step_over_info ();
7488 tp
->control
.trap_expected
= 0;
7490 insert_single_step_breakpoint (get_frame_arch (frame
),
7491 get_frame_address_space (frame
),
7492 tp
->suspend
.stop_pc
);
7495 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7496 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7501 fprintf_unfiltered (gdb_stdlog
,
7502 "infrun: expected thread still hasn't advanced\n");
7504 keep_going_pass_signal (ecs
);
7509 /* Is thread TP in the middle of (software or hardware)
7510 single-stepping? (Note the result of this function must never be
7511 passed directly as target_resume's STEP parameter.) */
7514 currently_stepping (struct thread_info
*tp
)
7516 return ((tp
->control
.step_range_end
7517 && tp
->control
.step_resume_breakpoint
== NULL
)
7518 || tp
->control
.trap_expected
7519 || tp
->stepped_breakpoint
7520 || bpstat_should_step ());
7523 /* Inferior has stepped into a subroutine call with source code that
7524 we should not step over. Do step to the first line of code in
7528 handle_step_into_function (struct gdbarch
*gdbarch
,
7529 struct execution_control_state
*ecs
)
7531 fill_in_stop_func (gdbarch
, ecs
);
7533 compunit_symtab
*cust
7534 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7535 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7536 ecs
->stop_func_start
7537 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7539 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7540 /* Use the step_resume_break to step until the end of the prologue,
7541 even if that involves jumps (as it seems to on the vax under
7543 /* If the prologue ends in the middle of a source line, continue to
7544 the end of that source line (if it is still within the function).
7545 Otherwise, just go to end of prologue. */
7546 if (stop_func_sal
.end
7547 && stop_func_sal
.pc
!= ecs
->stop_func_start
7548 && stop_func_sal
.end
< ecs
->stop_func_end
)
7549 ecs
->stop_func_start
= stop_func_sal
.end
;
7551 /* Architectures which require breakpoint adjustment might not be able
7552 to place a breakpoint at the computed address. If so, the test
7553 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7554 ecs->stop_func_start to an address at which a breakpoint may be
7555 legitimately placed.
7557 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7558 made, GDB will enter an infinite loop when stepping through
7559 optimized code consisting of VLIW instructions which contain
7560 subinstructions corresponding to different source lines. On
7561 FR-V, it's not permitted to place a breakpoint on any but the
7562 first subinstruction of a VLIW instruction. When a breakpoint is
7563 set, GDB will adjust the breakpoint address to the beginning of
7564 the VLIW instruction. Thus, we need to make the corresponding
7565 adjustment here when computing the stop address. */
7567 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7569 ecs
->stop_func_start
7570 = gdbarch_adjust_breakpoint_address (gdbarch
,
7571 ecs
->stop_func_start
);
7574 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7576 /* We are already there: stop now. */
7577 end_stepping_range (ecs
);
7582 /* Put the step-breakpoint there and go until there. */
7583 symtab_and_line sr_sal
;
7584 sr_sal
.pc
= ecs
->stop_func_start
;
7585 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7586 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7588 /* Do not specify what the fp should be when we stop since on
7589 some machines the prologue is where the new fp value is
7591 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7593 /* And make sure stepping stops right away then. */
7594 ecs
->event_thread
->control
.step_range_end
7595 = ecs
->event_thread
->control
.step_range_start
;
7600 /* Inferior has stepped backward into a subroutine call with source
7601 code that we should not step over. Do step to the beginning of the
7602 last line of code in it. */
7605 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7606 struct execution_control_state
*ecs
)
7608 struct compunit_symtab
*cust
;
7609 struct symtab_and_line stop_func_sal
;
7611 fill_in_stop_func (gdbarch
, ecs
);
7613 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7614 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7615 ecs
->stop_func_start
7616 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7618 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7620 /* OK, we're just going to keep stepping here. */
7621 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7623 /* We're there already. Just stop stepping now. */
7624 end_stepping_range (ecs
);
7628 /* Else just reset the step range and keep going.
7629 No step-resume breakpoint, they don't work for
7630 epilogues, which can have multiple entry paths. */
7631 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7632 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7638 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7639 This is used to both functions and to skip over code. */
7642 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7643 struct symtab_and_line sr_sal
,
7644 struct frame_id sr_id
,
7645 enum bptype sr_type
)
7647 /* There should never be more than one step-resume or longjmp-resume
7648 breakpoint per thread, so we should never be setting a new
7649 step_resume_breakpoint when one is already active. */
7650 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7651 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7654 fprintf_unfiltered (gdb_stdlog
,
7655 "infrun: inserting step-resume breakpoint at %s\n",
7656 paddress (gdbarch
, sr_sal
.pc
));
7658 inferior_thread ()->control
.step_resume_breakpoint
7659 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7663 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7664 struct symtab_and_line sr_sal
,
7665 struct frame_id sr_id
)
7667 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7672 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7673 This is used to skip a potential signal handler.
7675 This is called with the interrupted function's frame. The signal
7676 handler, when it returns, will resume the interrupted function at
7680 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7682 gdb_assert (return_frame
!= NULL
);
7684 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7686 symtab_and_line sr_sal
;
7687 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7688 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7689 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7691 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7692 get_stack_frame_id (return_frame
),
7696 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7697 is used to skip a function after stepping into it (for "next" or if
7698 the called function has no debugging information).
7700 The current function has almost always been reached by single
7701 stepping a call or return instruction. NEXT_FRAME belongs to the
7702 current function, and the breakpoint will be set at the caller's
7705 This is a separate function rather than reusing
7706 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7707 get_prev_frame, which may stop prematurely (see the implementation
7708 of frame_unwind_caller_id for an example). */
7711 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7713 /* We shouldn't have gotten here if we don't know where the call site
7715 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7717 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7719 symtab_and_line sr_sal
;
7720 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7721 frame_unwind_caller_pc (next_frame
));
7722 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7723 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7725 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7726 frame_unwind_caller_id (next_frame
));
7729 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7730 new breakpoint at the target of a jmp_buf. The handling of
7731 longjmp-resume uses the same mechanisms used for handling
7732 "step-resume" breakpoints. */
7735 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7737 /* There should never be more than one longjmp-resume breakpoint per
7738 thread, so we should never be setting a new
7739 longjmp_resume_breakpoint when one is already active. */
7740 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7743 fprintf_unfiltered (gdb_stdlog
,
7744 "infrun: inserting longjmp-resume breakpoint at %s\n",
7745 paddress (gdbarch
, pc
));
7747 inferior_thread ()->control
.exception_resume_breakpoint
=
7748 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7751 /* Insert an exception resume breakpoint. TP is the thread throwing
7752 the exception. The block B is the block of the unwinder debug hook
7753 function. FRAME is the frame corresponding to the call to this
7754 function. SYM is the symbol of the function argument holding the
7755 target PC of the exception. */
7758 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7759 const struct block
*b
,
7760 struct frame_info
*frame
,
7765 struct block_symbol vsym
;
7766 struct value
*value
;
7768 struct breakpoint
*bp
;
7770 vsym
= lookup_symbol_search_name (sym
->search_name (),
7772 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7773 /* If the value was optimized out, revert to the old behavior. */
7774 if (! value_optimized_out (value
))
7776 handler
= value_as_address (value
);
7779 fprintf_unfiltered (gdb_stdlog
,
7780 "infrun: exception resume at %lx\n",
7781 (unsigned long) handler
);
7783 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7785 bp_exception_resume
).release ();
7787 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7790 bp
->thread
= tp
->global_num
;
7791 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7794 catch (const gdb_exception_error
&e
)
7796 /* We want to ignore errors here. */
7800 /* A helper for check_exception_resume that sets an
7801 exception-breakpoint based on a SystemTap probe. */
7804 insert_exception_resume_from_probe (struct thread_info
*tp
,
7805 const struct bound_probe
*probe
,
7806 struct frame_info
*frame
)
7808 struct value
*arg_value
;
7810 struct breakpoint
*bp
;
7812 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7816 handler
= value_as_address (arg_value
);
7819 fprintf_unfiltered (gdb_stdlog
,
7820 "infrun: exception resume at %s\n",
7821 paddress (get_objfile_arch (probe
->objfile
),
7824 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7825 handler
, bp_exception_resume
).release ();
7826 bp
->thread
= tp
->global_num
;
7827 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7830 /* This is called when an exception has been intercepted. Check to
7831 see whether the exception's destination is of interest, and if so,
7832 set an exception resume breakpoint there. */
7835 check_exception_resume (struct execution_control_state
*ecs
,
7836 struct frame_info
*frame
)
7838 struct bound_probe probe
;
7839 struct symbol
*func
;
7841 /* First see if this exception unwinding breakpoint was set via a
7842 SystemTap probe point. If so, the probe has two arguments: the
7843 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7844 set a breakpoint there. */
7845 probe
= find_probe_by_pc (get_frame_pc (frame
));
7848 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7852 func
= get_frame_function (frame
);
7858 const struct block
*b
;
7859 struct block_iterator iter
;
7863 /* The exception breakpoint is a thread-specific breakpoint on
7864 the unwinder's debug hook, declared as:
7866 void _Unwind_DebugHook (void *cfa, void *handler);
7868 The CFA argument indicates the frame to which control is
7869 about to be transferred. HANDLER is the destination PC.
7871 We ignore the CFA and set a temporary breakpoint at HANDLER.
7872 This is not extremely efficient but it avoids issues in gdb
7873 with computing the DWARF CFA, and it also works even in weird
7874 cases such as throwing an exception from inside a signal
7877 b
= SYMBOL_BLOCK_VALUE (func
);
7878 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7880 if (!SYMBOL_IS_ARGUMENT (sym
))
7887 insert_exception_resume_breakpoint (ecs
->event_thread
,
7893 catch (const gdb_exception_error
&e
)
7899 stop_waiting (struct execution_control_state
*ecs
)
7902 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7904 /* Let callers know we don't want to wait for the inferior anymore. */
7905 ecs
->wait_some_more
= 0;
7907 /* If all-stop, but there exists a non-stop target, stop all
7908 threads now that we're presenting the stop to the user. */
7909 if (!non_stop
&& exists_non_stop_target ())
7910 stop_all_threads ();
7913 /* Like keep_going, but passes the signal to the inferior, even if the
7914 signal is set to nopass. */
7917 keep_going_pass_signal (struct execution_control_state
*ecs
)
7919 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7920 gdb_assert (!ecs
->event_thread
->resumed
);
7922 /* Save the pc before execution, to compare with pc after stop. */
7923 ecs
->event_thread
->prev_pc
7924 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7926 if (ecs
->event_thread
->control
.trap_expected
)
7928 struct thread_info
*tp
= ecs
->event_thread
;
7931 fprintf_unfiltered (gdb_stdlog
,
7932 "infrun: %s has trap_expected set, "
7933 "resuming to collect trap\n",
7934 target_pid_to_str (tp
->ptid
).c_str ());
7936 /* We haven't yet gotten our trap, and either: intercepted a
7937 non-signal event (e.g., a fork); or took a signal which we
7938 are supposed to pass through to the inferior. Simply
7940 resume (ecs
->event_thread
->suspend
.stop_signal
);
7942 else if (step_over_info_valid_p ())
7944 /* Another thread is stepping over a breakpoint in-line. If
7945 this thread needs a step-over too, queue the request. In
7946 either case, this resume must be deferred for later. */
7947 struct thread_info
*tp
= ecs
->event_thread
;
7949 if (ecs
->hit_singlestep_breakpoint
7950 || thread_still_needs_step_over (tp
))
7953 fprintf_unfiltered (gdb_stdlog
,
7954 "infrun: step-over already in progress: "
7955 "step-over for %s deferred\n",
7956 target_pid_to_str (tp
->ptid
).c_str ());
7957 thread_step_over_chain_enqueue (tp
);
7962 fprintf_unfiltered (gdb_stdlog
,
7963 "infrun: step-over in progress: "
7964 "resume of %s deferred\n",
7965 target_pid_to_str (tp
->ptid
).c_str ());
7970 struct regcache
*regcache
= get_current_regcache ();
7973 step_over_what step_what
;
7975 /* Either the trap was not expected, but we are continuing
7976 anyway (if we got a signal, the user asked it be passed to
7979 We got our expected trap, but decided we should resume from
7982 We're going to run this baby now!
7984 Note that insert_breakpoints won't try to re-insert
7985 already inserted breakpoints. Therefore, we don't
7986 care if breakpoints were already inserted, or not. */
7988 /* If we need to step over a breakpoint, and we're not using
7989 displaced stepping to do so, insert all breakpoints
7990 (watchpoints, etc.) but the one we're stepping over, step one
7991 instruction, and then re-insert the breakpoint when that step
7994 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7996 remove_bp
= (ecs
->hit_singlestep_breakpoint
7997 || (step_what
& STEP_OVER_BREAKPOINT
));
7998 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
8000 /* We can't use displaced stepping if we need to step past a
8001 watchpoint. The instruction copied to the scratch pad would
8002 still trigger the watchpoint. */
8004 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8006 set_step_over_info (regcache
->aspace (),
8007 regcache_read_pc (regcache
), remove_wps
,
8008 ecs
->event_thread
->global_num
);
8010 else if (remove_wps
)
8011 set_step_over_info (NULL
, 0, remove_wps
, -1);
8013 /* If we now need to do an in-line step-over, we need to stop
8014 all other threads. Note this must be done before
8015 insert_breakpoints below, because that removes the breakpoint
8016 we're about to step over, otherwise other threads could miss
8018 if (step_over_info_valid_p () && target_is_non_stop_p ())
8019 stop_all_threads ();
8021 /* Stop stepping if inserting breakpoints fails. */
8024 insert_breakpoints ();
8026 catch (const gdb_exception_error
&e
)
8028 exception_print (gdb_stderr
, e
);
8030 clear_step_over_info ();
8034 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8036 resume (ecs
->event_thread
->suspend
.stop_signal
);
8039 prepare_to_wait (ecs
);
8042 /* Called when we should continue running the inferior, because the
8043 current event doesn't cause a user visible stop. This does the
8044 resuming part; waiting for the next event is done elsewhere. */
8047 keep_going (struct execution_control_state
*ecs
)
8049 if (ecs
->event_thread
->control
.trap_expected
8050 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8051 ecs
->event_thread
->control
.trap_expected
= 0;
8053 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8054 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8055 keep_going_pass_signal (ecs
);
8058 /* This function normally comes after a resume, before
8059 handle_inferior_event exits. It takes care of any last bits of
8060 housekeeping, and sets the all-important wait_some_more flag. */
8063 prepare_to_wait (struct execution_control_state
*ecs
)
8066 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
8068 ecs
->wait_some_more
= 1;
8070 if (!target_is_async_p ())
8071 mark_infrun_async_event_handler ();
8074 /* We are done with the step range of a step/next/si/ni command.
8075 Called once for each n of a "step n" operation. */
8078 end_stepping_range (struct execution_control_state
*ecs
)
8080 ecs
->event_thread
->control
.stop_step
= 1;
8084 /* Several print_*_reason functions to print why the inferior has stopped.
8085 We always print something when the inferior exits, or receives a signal.
8086 The rest of the cases are dealt with later on in normal_stop and
8087 print_it_typical. Ideally there should be a call to one of these
8088 print_*_reason functions functions from handle_inferior_event each time
8089 stop_waiting is called.
8091 Note that we don't call these directly, instead we delegate that to
8092 the interpreters, through observers. Interpreters then call these
8093 with whatever uiout is right. */
8096 print_end_stepping_range_reason (struct ui_out
*uiout
)
8098 /* For CLI-like interpreters, print nothing. */
8100 if (uiout
->is_mi_like_p ())
8102 uiout
->field_string ("reason",
8103 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8108 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8110 annotate_signalled ();
8111 if (uiout
->is_mi_like_p ())
8113 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8114 uiout
->text ("\nProgram terminated with signal ");
8115 annotate_signal_name ();
8116 uiout
->field_string ("signal-name",
8117 gdb_signal_to_name (siggnal
));
8118 annotate_signal_name_end ();
8120 annotate_signal_string ();
8121 uiout
->field_string ("signal-meaning",
8122 gdb_signal_to_string (siggnal
));
8123 annotate_signal_string_end ();
8124 uiout
->text (".\n");
8125 uiout
->text ("The program no longer exists.\n");
8129 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8131 struct inferior
*inf
= current_inferior ();
8132 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8134 annotate_exited (exitstatus
);
8137 if (uiout
->is_mi_like_p ())
8138 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8139 std::string exit_code_str
8140 = string_printf ("0%o", (unsigned int) exitstatus
);
8141 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8142 plongest (inf
->num
), pidstr
.c_str (),
8143 string_field ("exit-code", exit_code_str
.c_str ()));
8147 if (uiout
->is_mi_like_p ())
8149 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8150 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8151 plongest (inf
->num
), pidstr
.c_str ());
8155 /* Some targets/architectures can do extra processing/display of
8156 segmentation faults. E.g., Intel MPX boundary faults.
8157 Call the architecture dependent function to handle the fault. */
8160 handle_segmentation_fault (struct ui_out
*uiout
)
8162 struct regcache
*regcache
= get_current_regcache ();
8163 struct gdbarch
*gdbarch
= regcache
->arch ();
8165 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8166 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8170 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8172 struct thread_info
*thr
= inferior_thread ();
8176 if (uiout
->is_mi_like_p ())
8178 else if (show_thread_that_caused_stop ())
8182 uiout
->text ("\nThread ");
8183 uiout
->field_string ("thread-id", print_thread_id (thr
));
8185 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8188 uiout
->text (" \"");
8189 uiout
->field_string ("name", name
);
8194 uiout
->text ("\nProgram");
8196 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8197 uiout
->text (" stopped");
8200 uiout
->text (" received signal ");
8201 annotate_signal_name ();
8202 if (uiout
->is_mi_like_p ())
8204 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8205 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8206 annotate_signal_name_end ();
8208 annotate_signal_string ();
8209 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8211 if (siggnal
== GDB_SIGNAL_SEGV
)
8212 handle_segmentation_fault (uiout
);
8214 annotate_signal_string_end ();
8216 uiout
->text (".\n");
8220 print_no_history_reason (struct ui_out
*uiout
)
8222 uiout
->text ("\nNo more reverse-execution history.\n");
8225 /* Print current location without a level number, if we have changed
8226 functions or hit a breakpoint. Print source line if we have one.
8227 bpstat_print contains the logic deciding in detail what to print,
8228 based on the event(s) that just occurred. */
8231 print_stop_location (struct target_waitstatus
*ws
)
8234 enum print_what source_flag
;
8235 int do_frame_printing
= 1;
8236 struct thread_info
*tp
= inferior_thread ();
8238 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8242 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8243 should) carry around the function and does (or should) use
8244 that when doing a frame comparison. */
8245 if (tp
->control
.stop_step
8246 && frame_id_eq (tp
->control
.step_frame_id
,
8247 get_frame_id (get_current_frame ()))
8248 && (tp
->control
.step_start_function
8249 == find_pc_function (tp
->suspend
.stop_pc
)))
8251 /* Finished step, just print source line. */
8252 source_flag
= SRC_LINE
;
8256 /* Print location and source line. */
8257 source_flag
= SRC_AND_LOC
;
8260 case PRINT_SRC_AND_LOC
:
8261 /* Print location and source line. */
8262 source_flag
= SRC_AND_LOC
;
8264 case PRINT_SRC_ONLY
:
8265 source_flag
= SRC_LINE
;
8268 /* Something bogus. */
8269 source_flag
= SRC_LINE
;
8270 do_frame_printing
= 0;
8273 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8276 /* The behavior of this routine with respect to the source
8278 SRC_LINE: Print only source line
8279 LOCATION: Print only location
8280 SRC_AND_LOC: Print location and source line. */
8281 if (do_frame_printing
)
8282 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8288 print_stop_event (struct ui_out
*uiout
, bool displays
)
8290 struct target_waitstatus last
;
8291 struct thread_info
*tp
;
8293 get_last_target_status (nullptr, nullptr, &last
);
8296 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8298 print_stop_location (&last
);
8300 /* Display the auto-display expressions. */
8305 tp
= inferior_thread ();
8306 if (tp
->thread_fsm
!= NULL
8307 && tp
->thread_fsm
->finished_p ())
8309 struct return_value_info
*rv
;
8311 rv
= tp
->thread_fsm
->return_value ();
8313 print_return_value (uiout
, rv
);
8320 maybe_remove_breakpoints (void)
8322 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8324 if (remove_breakpoints ())
8326 target_terminal::ours_for_output ();
8327 printf_filtered (_("Cannot remove breakpoints because "
8328 "program is no longer writable.\nFurther "
8329 "execution is probably impossible.\n"));
8334 /* The execution context that just caused a normal stop. */
8341 DISABLE_COPY_AND_ASSIGN (stop_context
);
8343 bool changed () const;
8348 /* The event PTID. */
8352 /* If stopp for a thread event, this is the thread that caused the
8354 struct thread_info
*thread
;
8356 /* The inferior that caused the stop. */
8360 /* Initializes a new stop context. If stopped for a thread event, this
8361 takes a strong reference to the thread. */
8363 stop_context::stop_context ()
8365 stop_id
= get_stop_id ();
8366 ptid
= inferior_ptid
;
8367 inf_num
= current_inferior ()->num
;
8369 if (inferior_ptid
!= null_ptid
)
8371 /* Take a strong reference so that the thread can't be deleted
8373 thread
= inferior_thread ();
8380 /* Release a stop context previously created with save_stop_context.
8381 Releases the strong reference to the thread as well. */
8383 stop_context::~stop_context ()
8389 /* Return true if the current context no longer matches the saved stop
8393 stop_context::changed () const
8395 if (ptid
!= inferior_ptid
)
8397 if (inf_num
!= current_inferior ()->num
)
8399 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8401 if (get_stop_id () != stop_id
)
8411 struct target_waitstatus last
;
8413 get_last_target_status (nullptr, nullptr, &last
);
8417 /* If an exception is thrown from this point on, make sure to
8418 propagate GDB's knowledge of the executing state to the
8419 frontend/user running state. A QUIT is an easy exception to see
8420 here, so do this before any filtered output. */
8422 ptid_t finish_ptid
= null_ptid
;
8425 finish_ptid
= minus_one_ptid
;
8426 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8427 || last
.kind
== TARGET_WAITKIND_EXITED
)
8429 /* On some targets, we may still have live threads in the
8430 inferior when we get a process exit event. E.g., for
8431 "checkpoint", when the current checkpoint/fork exits,
8432 linux-fork.c automatically switches to another fork from
8433 within target_mourn_inferior. */
8434 if (inferior_ptid
!= null_ptid
)
8435 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8437 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8438 finish_ptid
= inferior_ptid
;
8440 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8441 if (finish_ptid
!= null_ptid
)
8443 maybe_finish_thread_state
.emplace
8444 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8447 /* As we're presenting a stop, and potentially removing breakpoints,
8448 update the thread list so we can tell whether there are threads
8449 running on the target. With target remote, for example, we can
8450 only learn about new threads when we explicitly update the thread
8451 list. Do this before notifying the interpreters about signal
8452 stops, end of stepping ranges, etc., so that the "new thread"
8453 output is emitted before e.g., "Program received signal FOO",
8454 instead of after. */
8455 update_thread_list ();
8457 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8458 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8460 /* As with the notification of thread events, we want to delay
8461 notifying the user that we've switched thread context until
8462 the inferior actually stops.
8464 There's no point in saying anything if the inferior has exited.
8465 Note that SIGNALLED here means "exited with a signal", not
8466 "received a signal".
8468 Also skip saying anything in non-stop mode. In that mode, as we
8469 don't want GDB to switch threads behind the user's back, to avoid
8470 races where the user is typing a command to apply to thread x,
8471 but GDB switches to thread y before the user finishes entering
8472 the command, fetch_inferior_event installs a cleanup to restore
8473 the current thread back to the thread the user had selected right
8474 after this event is handled, so we're not really switching, only
8475 informing of a stop. */
8477 && previous_inferior_ptid
!= inferior_ptid
8478 && target_has_execution
8479 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8480 && last
.kind
!= TARGET_WAITKIND_EXITED
8481 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8483 SWITCH_THRU_ALL_UIS ()
8485 target_terminal::ours_for_output ();
8486 printf_filtered (_("[Switching to %s]\n"),
8487 target_pid_to_str (inferior_ptid
).c_str ());
8488 annotate_thread_changed ();
8490 previous_inferior_ptid
= inferior_ptid
;
8493 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8495 SWITCH_THRU_ALL_UIS ()
8496 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8498 target_terminal::ours_for_output ();
8499 printf_filtered (_("No unwaited-for children left.\n"));
8503 /* Note: this depends on the update_thread_list call above. */
8504 maybe_remove_breakpoints ();
8506 /* If an auto-display called a function and that got a signal,
8507 delete that auto-display to avoid an infinite recursion. */
8509 if (stopped_by_random_signal
)
8510 disable_current_display ();
8512 SWITCH_THRU_ALL_UIS ()
8514 async_enable_stdin ();
8517 /* Let the user/frontend see the threads as stopped. */
8518 maybe_finish_thread_state
.reset ();
8520 /* Select innermost stack frame - i.e., current frame is frame 0,
8521 and current location is based on that. Handle the case where the
8522 dummy call is returning after being stopped. E.g. the dummy call
8523 previously hit a breakpoint. (If the dummy call returns
8524 normally, we won't reach here.) Do this before the stop hook is
8525 run, so that it doesn't get to see the temporary dummy frame,
8526 which is not where we'll present the stop. */
8527 if (has_stack_frames ())
8529 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8531 /* Pop the empty frame that contains the stack dummy. This
8532 also restores inferior state prior to the call (struct
8533 infcall_suspend_state). */
8534 struct frame_info
*frame
= get_current_frame ();
8536 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8538 /* frame_pop calls reinit_frame_cache as the last thing it
8539 does which means there's now no selected frame. */
8542 select_frame (get_current_frame ());
8544 /* Set the current source location. */
8545 set_current_sal_from_frame (get_current_frame ());
8548 /* Look up the hook_stop and run it (CLI internally handles problem
8549 of stop_command's pre-hook not existing). */
8550 if (stop_command
!= NULL
)
8552 stop_context saved_context
;
8556 execute_cmd_pre_hook (stop_command
);
8558 catch (const gdb_exception
&ex
)
8560 exception_fprintf (gdb_stderr
, ex
,
8561 "Error while running hook_stop:\n");
8564 /* If the stop hook resumes the target, then there's no point in
8565 trying to notify about the previous stop; its context is
8566 gone. Likewise if the command switches thread or inferior --
8567 the observers would print a stop for the wrong
8569 if (saved_context
.changed ())
8573 /* Notify observers about the stop. This is where the interpreters
8574 print the stop event. */
8575 if (inferior_ptid
!= null_ptid
)
8576 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8579 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8581 annotate_stopped ();
8583 if (target_has_execution
)
8585 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8586 && last
.kind
!= TARGET_WAITKIND_EXITED
8587 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8588 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8589 Delete any breakpoint that is to be deleted at the next stop. */
8590 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8593 /* Try to get rid of automatically added inferiors that are no
8594 longer needed. Keeping those around slows down things linearly.
8595 Note that this never removes the current inferior. */
8602 signal_stop_state (int signo
)
8604 return signal_stop
[signo
];
8608 signal_print_state (int signo
)
8610 return signal_print
[signo
];
8614 signal_pass_state (int signo
)
8616 return signal_program
[signo
];
8620 signal_cache_update (int signo
)
8624 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8625 signal_cache_update (signo
);
8630 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8631 && signal_print
[signo
] == 0
8632 && signal_program
[signo
] == 1
8633 && signal_catch
[signo
] == 0);
8637 signal_stop_update (int signo
, int state
)
8639 int ret
= signal_stop
[signo
];
8641 signal_stop
[signo
] = state
;
8642 signal_cache_update (signo
);
8647 signal_print_update (int signo
, int state
)
8649 int ret
= signal_print
[signo
];
8651 signal_print
[signo
] = state
;
8652 signal_cache_update (signo
);
8657 signal_pass_update (int signo
, int state
)
8659 int ret
= signal_program
[signo
];
8661 signal_program
[signo
] = state
;
8662 signal_cache_update (signo
);
8666 /* Update the global 'signal_catch' from INFO and notify the
8670 signal_catch_update (const unsigned int *info
)
8674 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8675 signal_catch
[i
] = info
[i
] > 0;
8676 signal_cache_update (-1);
8677 target_pass_signals (signal_pass
);
8681 sig_print_header (void)
8683 printf_filtered (_("Signal Stop\tPrint\tPass "
8684 "to program\tDescription\n"));
8688 sig_print_info (enum gdb_signal oursig
)
8690 const char *name
= gdb_signal_to_name (oursig
);
8691 int name_padding
= 13 - strlen (name
);
8693 if (name_padding
<= 0)
8696 printf_filtered ("%s", name
);
8697 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8698 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8699 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8700 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8701 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8704 /* Specify how various signals in the inferior should be handled. */
8707 handle_command (const char *args
, int from_tty
)
8709 int digits
, wordlen
;
8710 int sigfirst
, siglast
;
8711 enum gdb_signal oursig
;
8716 error_no_arg (_("signal to handle"));
8719 /* Allocate and zero an array of flags for which signals to handle. */
8721 const size_t nsigs
= GDB_SIGNAL_LAST
;
8722 unsigned char sigs
[nsigs
] {};
8724 /* Break the command line up into args. */
8726 gdb_argv
built_argv (args
);
8728 /* Walk through the args, looking for signal oursigs, signal names, and
8729 actions. Signal numbers and signal names may be interspersed with
8730 actions, with the actions being performed for all signals cumulatively
8731 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8733 for (char *arg
: built_argv
)
8735 wordlen
= strlen (arg
);
8736 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8740 sigfirst
= siglast
= -1;
8742 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8744 /* Apply action to all signals except those used by the
8745 debugger. Silently skip those. */
8748 siglast
= nsigs
- 1;
8750 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8752 SET_SIGS (nsigs
, sigs
, signal_stop
);
8753 SET_SIGS (nsigs
, sigs
, signal_print
);
8755 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8757 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8759 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8761 SET_SIGS (nsigs
, sigs
, signal_print
);
8763 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8765 SET_SIGS (nsigs
, sigs
, signal_program
);
8767 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8769 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8771 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8773 SET_SIGS (nsigs
, sigs
, signal_program
);
8775 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8777 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8778 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8780 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8782 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8784 else if (digits
> 0)
8786 /* It is numeric. The numeric signal refers to our own
8787 internal signal numbering from target.h, not to host/target
8788 signal number. This is a feature; users really should be
8789 using symbolic names anyway, and the common ones like
8790 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8792 sigfirst
= siglast
= (int)
8793 gdb_signal_from_command (atoi (arg
));
8794 if (arg
[digits
] == '-')
8797 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8799 if (sigfirst
> siglast
)
8801 /* Bet he didn't figure we'd think of this case... */
8802 std::swap (sigfirst
, siglast
);
8807 oursig
= gdb_signal_from_name (arg
);
8808 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8810 sigfirst
= siglast
= (int) oursig
;
8814 /* Not a number and not a recognized flag word => complain. */
8815 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8819 /* If any signal numbers or symbol names were found, set flags for
8820 which signals to apply actions to. */
8822 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8824 switch ((enum gdb_signal
) signum
)
8826 case GDB_SIGNAL_TRAP
:
8827 case GDB_SIGNAL_INT
:
8828 if (!allsigs
&& !sigs
[signum
])
8830 if (query (_("%s is used by the debugger.\n\
8831 Are you sure you want to change it? "),
8832 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8837 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8841 case GDB_SIGNAL_DEFAULT
:
8842 case GDB_SIGNAL_UNKNOWN
:
8843 /* Make sure that "all" doesn't print these. */
8852 for (int signum
= 0; signum
< nsigs
; signum
++)
8855 signal_cache_update (-1);
8856 target_pass_signals (signal_pass
);
8857 target_program_signals (signal_program
);
8861 /* Show the results. */
8862 sig_print_header ();
8863 for (; signum
< nsigs
; signum
++)
8865 sig_print_info ((enum gdb_signal
) signum
);
8872 /* Complete the "handle" command. */
8875 handle_completer (struct cmd_list_element
*ignore
,
8876 completion_tracker
&tracker
,
8877 const char *text
, const char *word
)
8879 static const char * const keywords
[] =
8893 signal_completer (ignore
, tracker
, text
, word
);
8894 complete_on_enum (tracker
, keywords
, word
, word
);
8898 gdb_signal_from_command (int num
)
8900 if (num
>= 1 && num
<= 15)
8901 return (enum gdb_signal
) num
;
8902 error (_("Only signals 1-15 are valid as numeric signals.\n\
8903 Use \"info signals\" for a list of symbolic signals."));
8906 /* Print current contents of the tables set by the handle command.
8907 It is possible we should just be printing signals actually used
8908 by the current target (but for things to work right when switching
8909 targets, all signals should be in the signal tables). */
8912 info_signals_command (const char *signum_exp
, int from_tty
)
8914 enum gdb_signal oursig
;
8916 sig_print_header ();
8920 /* First see if this is a symbol name. */
8921 oursig
= gdb_signal_from_name (signum_exp
);
8922 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8924 /* No, try numeric. */
8926 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8928 sig_print_info (oursig
);
8932 printf_filtered ("\n");
8933 /* These ugly casts brought to you by the native VAX compiler. */
8934 for (oursig
= GDB_SIGNAL_FIRST
;
8935 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8936 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8940 if (oursig
!= GDB_SIGNAL_UNKNOWN
8941 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8942 sig_print_info (oursig
);
8945 printf_filtered (_("\nUse the \"handle\" command "
8946 "to change these tables.\n"));
8949 /* The $_siginfo convenience variable is a bit special. We don't know
8950 for sure the type of the value until we actually have a chance to
8951 fetch the data. The type can change depending on gdbarch, so it is
8952 also dependent on which thread you have selected.
8954 1. making $_siginfo be an internalvar that creates a new value on
8957 2. making the value of $_siginfo be an lval_computed value. */
8959 /* This function implements the lval_computed support for reading a
8963 siginfo_value_read (struct value
*v
)
8965 LONGEST transferred
;
8967 /* If we can access registers, so can we access $_siginfo. Likewise
8969 validate_registers_access ();
8972 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8974 value_contents_all_raw (v
),
8976 TYPE_LENGTH (value_type (v
)));
8978 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8979 error (_("Unable to read siginfo"));
8982 /* This function implements the lval_computed support for writing a
8986 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8988 LONGEST transferred
;
8990 /* If we can access registers, so can we access $_siginfo. Likewise
8992 validate_registers_access ();
8994 transferred
= target_write (current_top_target (),
8995 TARGET_OBJECT_SIGNAL_INFO
,
8997 value_contents_all_raw (fromval
),
8999 TYPE_LENGTH (value_type (fromval
)));
9001 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
9002 error (_("Unable to write siginfo"));
9005 static const struct lval_funcs siginfo_value_funcs
=
9011 /* Return a new value with the correct type for the siginfo object of
9012 the current thread using architecture GDBARCH. Return a void value
9013 if there's no object available. */
9015 static struct value
*
9016 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9019 if (target_has_stack
9020 && inferior_ptid
!= null_ptid
9021 && gdbarch_get_siginfo_type_p (gdbarch
))
9023 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9025 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9028 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9032 /* infcall_suspend_state contains state about the program itself like its
9033 registers and any signal it received when it last stopped.
9034 This state must be restored regardless of how the inferior function call
9035 ends (either successfully, or after it hits a breakpoint or signal)
9036 if the program is to properly continue where it left off. */
9038 class infcall_suspend_state
9041 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9042 once the inferior function call has finished. */
9043 infcall_suspend_state (struct gdbarch
*gdbarch
,
9044 const struct thread_info
*tp
,
9045 struct regcache
*regcache
)
9046 : m_thread_suspend (tp
->suspend
),
9047 m_registers (new readonly_detached_regcache (*regcache
))
9049 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9051 if (gdbarch_get_siginfo_type_p (gdbarch
))
9053 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9054 size_t len
= TYPE_LENGTH (type
);
9056 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9058 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9059 siginfo_data
.get (), 0, len
) != len
)
9061 /* Errors ignored. */
9062 siginfo_data
.reset (nullptr);
9068 m_siginfo_gdbarch
= gdbarch
;
9069 m_siginfo_data
= std::move (siginfo_data
);
9073 /* Return a pointer to the stored register state. */
9075 readonly_detached_regcache
*registers () const
9077 return m_registers
.get ();
9080 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9082 void restore (struct gdbarch
*gdbarch
,
9083 struct thread_info
*tp
,
9084 struct regcache
*regcache
) const
9086 tp
->suspend
= m_thread_suspend
;
9088 if (m_siginfo_gdbarch
== gdbarch
)
9090 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9092 /* Errors ignored. */
9093 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9094 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9097 /* The inferior can be gone if the user types "print exit(0)"
9098 (and perhaps other times). */
9099 if (target_has_execution
)
9100 /* NB: The register write goes through to the target. */
9101 regcache
->restore (registers ());
9105 /* How the current thread stopped before the inferior function call was
9107 struct thread_suspend_state m_thread_suspend
;
9109 /* The registers before the inferior function call was executed. */
9110 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9112 /* Format of SIGINFO_DATA or NULL if it is not present. */
9113 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9115 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9116 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9117 content would be invalid. */
9118 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9121 infcall_suspend_state_up
9122 save_infcall_suspend_state ()
9124 struct thread_info
*tp
= inferior_thread ();
9125 struct regcache
*regcache
= get_current_regcache ();
9126 struct gdbarch
*gdbarch
= regcache
->arch ();
9128 infcall_suspend_state_up inf_state
9129 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9131 /* Having saved the current state, adjust the thread state, discarding
9132 any stop signal information. The stop signal is not useful when
9133 starting an inferior function call, and run_inferior_call will not use
9134 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9135 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9140 /* Restore inferior session state to INF_STATE. */
9143 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9145 struct thread_info
*tp
= inferior_thread ();
9146 struct regcache
*regcache
= get_current_regcache ();
9147 struct gdbarch
*gdbarch
= regcache
->arch ();
9149 inf_state
->restore (gdbarch
, tp
, regcache
);
9150 discard_infcall_suspend_state (inf_state
);
9154 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9159 readonly_detached_regcache
*
9160 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9162 return inf_state
->registers ();
9165 /* infcall_control_state contains state regarding gdb's control of the
9166 inferior itself like stepping control. It also contains session state like
9167 the user's currently selected frame. */
9169 struct infcall_control_state
9171 struct thread_control_state thread_control
;
9172 struct inferior_control_state inferior_control
;
9175 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9176 int stopped_by_random_signal
= 0;
9178 /* ID if the selected frame when the inferior function call was made. */
9179 struct frame_id selected_frame_id
{};
9182 /* Save all of the information associated with the inferior<==>gdb
9185 infcall_control_state_up
9186 save_infcall_control_state ()
9188 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9189 struct thread_info
*tp
= inferior_thread ();
9190 struct inferior
*inf
= current_inferior ();
9192 inf_status
->thread_control
= tp
->control
;
9193 inf_status
->inferior_control
= inf
->control
;
9195 tp
->control
.step_resume_breakpoint
= NULL
;
9196 tp
->control
.exception_resume_breakpoint
= NULL
;
9198 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9199 chain. If caller's caller is walking the chain, they'll be happier if we
9200 hand them back the original chain when restore_infcall_control_state is
9202 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9205 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9206 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9208 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9214 restore_selected_frame (const frame_id
&fid
)
9216 frame_info
*frame
= frame_find_by_id (fid
);
9218 /* If inf_status->selected_frame_id is NULL, there was no previously
9222 warning (_("Unable to restore previously selected frame."));
9226 select_frame (frame
);
9229 /* Restore inferior session state to INF_STATUS. */
9232 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9234 struct thread_info
*tp
= inferior_thread ();
9235 struct inferior
*inf
= current_inferior ();
9237 if (tp
->control
.step_resume_breakpoint
)
9238 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9240 if (tp
->control
.exception_resume_breakpoint
)
9241 tp
->control
.exception_resume_breakpoint
->disposition
9242 = disp_del_at_next_stop
;
9244 /* Handle the bpstat_copy of the chain. */
9245 bpstat_clear (&tp
->control
.stop_bpstat
);
9247 tp
->control
= inf_status
->thread_control
;
9248 inf
->control
= inf_status
->inferior_control
;
9251 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9252 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9254 if (target_has_stack
)
9256 /* The point of the try/catch is that if the stack is clobbered,
9257 walking the stack might encounter a garbage pointer and
9258 error() trying to dereference it. */
9261 restore_selected_frame (inf_status
->selected_frame_id
);
9263 catch (const gdb_exception_error
&ex
)
9265 exception_fprintf (gdb_stderr
, ex
,
9266 "Unable to restore previously selected frame:\n");
9267 /* Error in restoring the selected frame. Select the
9269 select_frame (get_current_frame ());
9277 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9279 if (inf_status
->thread_control
.step_resume_breakpoint
)
9280 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9281 = disp_del_at_next_stop
;
9283 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9284 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9285 = disp_del_at_next_stop
;
9287 /* See save_infcall_control_state for info on stop_bpstat. */
9288 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9296 clear_exit_convenience_vars (void)
9298 clear_internalvar (lookup_internalvar ("_exitsignal"));
9299 clear_internalvar (lookup_internalvar ("_exitcode"));
9303 /* User interface for reverse debugging:
9304 Set exec-direction / show exec-direction commands
9305 (returns error unless target implements to_set_exec_direction method). */
9307 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9308 static const char exec_forward
[] = "forward";
9309 static const char exec_reverse
[] = "reverse";
9310 static const char *exec_direction
= exec_forward
;
9311 static const char *const exec_direction_names
[] = {
9318 set_exec_direction_func (const char *args
, int from_tty
,
9319 struct cmd_list_element
*cmd
)
9321 if (target_can_execute_reverse
)
9323 if (!strcmp (exec_direction
, exec_forward
))
9324 execution_direction
= EXEC_FORWARD
;
9325 else if (!strcmp (exec_direction
, exec_reverse
))
9326 execution_direction
= EXEC_REVERSE
;
9330 exec_direction
= exec_forward
;
9331 error (_("Target does not support this operation."));
9336 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9337 struct cmd_list_element
*cmd
, const char *value
)
9339 switch (execution_direction
) {
9341 fprintf_filtered (out
, _("Forward.\n"));
9344 fprintf_filtered (out
, _("Reverse.\n"));
9347 internal_error (__FILE__
, __LINE__
,
9348 _("bogus execution_direction value: %d"),
9349 (int) execution_direction
);
9354 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9355 struct cmd_list_element
*c
, const char *value
)
9357 fprintf_filtered (file
, _("Resuming the execution of threads "
9358 "of all processes is %s.\n"), value
);
9361 /* Implementation of `siginfo' variable. */
9363 static const struct internalvar_funcs siginfo_funcs
=
9370 /* Callback for infrun's target events source. This is marked when a
9371 thread has a pending status to process. */
9374 infrun_async_inferior_event_handler (gdb_client_data data
)
9376 inferior_event_handler (INF_REG_EVENT
, NULL
);
9379 void _initialize_infrun ();
9381 _initialize_infrun ()
9383 struct cmd_list_element
*c
;
9385 /* Register extra event sources in the event loop. */
9386 infrun_async_inferior_event_token
9387 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9389 add_info ("signals", info_signals_command
, _("\
9390 What debugger does when program gets various signals.\n\
9391 Specify a signal as argument to print info on that signal only."));
9392 add_info_alias ("handle", "signals", 0);
9394 c
= add_com ("handle", class_run
, handle_command
, _("\
9395 Specify how to handle signals.\n\
9396 Usage: handle SIGNAL [ACTIONS]\n\
9397 Args are signals and actions to apply to those signals.\n\
9398 If no actions are specified, the current settings for the specified signals\n\
9399 will be displayed instead.\n\
9401 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9402 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9403 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9404 The special arg \"all\" is recognized to mean all signals except those\n\
9405 used by the debugger, typically SIGTRAP and SIGINT.\n\
9407 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9408 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9409 Stop means reenter debugger if this signal happens (implies print).\n\
9410 Print means print a message if this signal happens.\n\
9411 Pass means let program see this signal; otherwise program doesn't know.\n\
9412 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9413 Pass and Stop may be combined.\n\
9415 Multiple signals may be specified. Signal numbers and signal names\n\
9416 may be interspersed with actions, with the actions being performed for\n\
9417 all signals cumulatively specified."));
9418 set_cmd_completer (c
, handle_completer
);
9421 stop_command
= add_cmd ("stop", class_obscure
,
9422 not_just_help_class_command
, _("\
9423 There is no `stop' command, but you can set a hook on `stop'.\n\
9424 This allows you to set a list of commands to be run each time execution\n\
9425 of the program stops."), &cmdlist
);
9427 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9428 Set inferior debugging."), _("\
9429 Show inferior debugging."), _("\
9430 When non-zero, inferior specific debugging is enabled."),
9433 &setdebuglist
, &showdebuglist
);
9435 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9436 &debug_displaced
, _("\
9437 Set displaced stepping debugging."), _("\
9438 Show displaced stepping debugging."), _("\
9439 When non-zero, displaced stepping specific debugging is enabled."),
9441 show_debug_displaced
,
9442 &setdebuglist
, &showdebuglist
);
9444 add_setshow_boolean_cmd ("non-stop", no_class
,
9446 Set whether gdb controls the inferior in non-stop mode."), _("\
9447 Show whether gdb controls the inferior in non-stop mode."), _("\
9448 When debugging a multi-threaded program and this setting is\n\
9449 off (the default, also called all-stop mode), when one thread stops\n\
9450 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9451 all other threads in the program while you interact with the thread of\n\
9452 interest. When you continue or step a thread, you can allow the other\n\
9453 threads to run, or have them remain stopped, but while you inspect any\n\
9454 thread's state, all threads stop.\n\
9456 In non-stop mode, when one thread stops, other threads can continue\n\
9457 to run freely. You'll be able to step each thread independently,\n\
9458 leave it stopped or free to run as needed."),
9464 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9467 signal_print
[i
] = 1;
9468 signal_program
[i
] = 1;
9469 signal_catch
[i
] = 0;
9472 /* Signals caused by debugger's own actions should not be given to
9473 the program afterwards.
9475 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9476 explicitly specifies that it should be delivered to the target
9477 program. Typically, that would occur when a user is debugging a
9478 target monitor on a simulator: the target monitor sets a
9479 breakpoint; the simulator encounters this breakpoint and halts
9480 the simulation handing control to GDB; GDB, noting that the stop
9481 address doesn't map to any known breakpoint, returns control back
9482 to the simulator; the simulator then delivers the hardware
9483 equivalent of a GDB_SIGNAL_TRAP to the program being
9485 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9486 signal_program
[GDB_SIGNAL_INT
] = 0;
9488 /* Signals that are not errors should not normally enter the debugger. */
9489 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9490 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9491 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9492 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9493 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9494 signal_print
[GDB_SIGNAL_PROF
] = 0;
9495 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9496 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9497 signal_stop
[GDB_SIGNAL_IO
] = 0;
9498 signal_print
[GDB_SIGNAL_IO
] = 0;
9499 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9500 signal_print
[GDB_SIGNAL_POLL
] = 0;
9501 signal_stop
[GDB_SIGNAL_URG
] = 0;
9502 signal_print
[GDB_SIGNAL_URG
] = 0;
9503 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9504 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9505 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9506 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9508 /* These signals are used internally by user-level thread
9509 implementations. (See signal(5) on Solaris.) Like the above
9510 signals, a healthy program receives and handles them as part of
9511 its normal operation. */
9512 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9513 signal_print
[GDB_SIGNAL_LWP
] = 0;
9514 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9515 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9516 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9517 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9518 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9519 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9521 /* Update cached state. */
9522 signal_cache_update (-1);
9524 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9525 &stop_on_solib_events
, _("\
9526 Set stopping for shared library events."), _("\
9527 Show stopping for shared library events."), _("\
9528 If nonzero, gdb will give control to the user when the dynamic linker\n\
9529 notifies gdb of shared library events. The most common event of interest\n\
9530 to the user would be loading/unloading of a new library."),
9531 set_stop_on_solib_events
,
9532 show_stop_on_solib_events
,
9533 &setlist
, &showlist
);
9535 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9536 follow_fork_mode_kind_names
,
9537 &follow_fork_mode_string
, _("\
9538 Set debugger response to a program call of fork or vfork."), _("\
9539 Show debugger response to a program call of fork or vfork."), _("\
9540 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9541 parent - the original process is debugged after a fork\n\
9542 child - the new process is debugged after a fork\n\
9543 The unfollowed process will continue to run.\n\
9544 By default, the debugger will follow the parent process."),
9546 show_follow_fork_mode_string
,
9547 &setlist
, &showlist
);
9549 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9550 follow_exec_mode_names
,
9551 &follow_exec_mode_string
, _("\
9552 Set debugger response to a program call of exec."), _("\
9553 Show debugger response to a program call of exec."), _("\
9554 An exec call replaces the program image of a process.\n\
9556 follow-exec-mode can be:\n\
9558 new - the debugger creates a new inferior and rebinds the process\n\
9559 to this new inferior. The program the process was running before\n\
9560 the exec call can be restarted afterwards by restarting the original\n\
9563 same - the debugger keeps the process bound to the same inferior.\n\
9564 The new executable image replaces the previous executable loaded in\n\
9565 the inferior. Restarting the inferior after the exec call restarts\n\
9566 the executable the process was running after the exec call.\n\
9568 By default, the debugger will use the same inferior."),
9570 show_follow_exec_mode_string
,
9571 &setlist
, &showlist
);
9573 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9574 scheduler_enums
, &scheduler_mode
, _("\
9575 Set mode for locking scheduler during execution."), _("\
9576 Show mode for locking scheduler during execution."), _("\
9577 off == no locking (threads may preempt at any time)\n\
9578 on == full locking (no thread except the current thread may run)\n\
9579 This applies to both normal execution and replay mode.\n\
9580 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9581 In this mode, other threads may run during other commands.\n\
9582 This applies to both normal execution and replay mode.\n\
9583 replay == scheduler locked in replay mode and unlocked during normal execution."),
9584 set_schedlock_func
, /* traps on target vector */
9585 show_scheduler_mode
,
9586 &setlist
, &showlist
);
9588 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9589 Set mode for resuming threads of all processes."), _("\
9590 Show mode for resuming threads of all processes."), _("\
9591 When on, execution commands (such as 'continue' or 'next') resume all\n\
9592 threads of all processes. When off (which is the default), execution\n\
9593 commands only resume the threads of the current process. The set of\n\
9594 threads that are resumed is further refined by the scheduler-locking\n\
9595 mode (see help set scheduler-locking)."),
9597 show_schedule_multiple
,
9598 &setlist
, &showlist
);
9600 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9601 Set mode of the step operation."), _("\
9602 Show mode of the step operation."), _("\
9603 When set, doing a step over a function without debug line information\n\
9604 will stop at the first instruction of that function. Otherwise, the\n\
9605 function is skipped and the step command stops at a different source line."),
9607 show_step_stop_if_no_debug
,
9608 &setlist
, &showlist
);
9610 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9611 &can_use_displaced_stepping
, _("\
9612 Set debugger's willingness to use displaced stepping."), _("\
9613 Show debugger's willingness to use displaced stepping."), _("\
9614 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9615 supported by the target architecture. If off, gdb will not use displaced\n\
9616 stepping to step over breakpoints, even if such is supported by the target\n\
9617 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9618 if the target architecture supports it and non-stop mode is active, but will not\n\
9619 use it in all-stop mode (see help set non-stop)."),
9621 show_can_use_displaced_stepping
,
9622 &setlist
, &showlist
);
9624 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9625 &exec_direction
, _("Set direction of execution.\n\
9626 Options are 'forward' or 'reverse'."),
9627 _("Show direction of execution (forward/reverse)."),
9628 _("Tells gdb whether to execute forward or backward."),
9629 set_exec_direction_func
, show_exec_direction_func
,
9630 &setlist
, &showlist
);
9632 /* Set/show detach-on-fork: user-settable mode. */
9634 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9635 Set whether gdb will detach the child of a fork."), _("\
9636 Show whether gdb will detach the child of a fork."), _("\
9637 Tells gdb whether to detach the child of a fork."),
9638 NULL
, NULL
, &setlist
, &showlist
);
9640 /* Set/show disable address space randomization mode. */
9642 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9643 &disable_randomization
, _("\
9644 Set disabling of debuggee's virtual address space randomization."), _("\
9645 Show disabling of debuggee's virtual address space randomization."), _("\
9646 When this mode is on (which is the default), randomization of the virtual\n\
9647 address space is disabled. Standalone programs run with the randomization\n\
9648 enabled by default on some platforms."),
9649 &set_disable_randomization
,
9650 &show_disable_randomization
,
9651 &setlist
, &showlist
);
9653 /* ptid initializations */
9654 inferior_ptid
= null_ptid
;
9655 target_last_wait_ptid
= minus_one_ptid
;
9657 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9658 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9659 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9660 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9662 /* Explicitly create without lookup, since that tries to create a
9663 value with a void typed value, and when we get here, gdbarch
9664 isn't initialized yet. At this point, we're quite sure there
9665 isn't another convenience variable of the same name. */
9666 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9668 add_setshow_boolean_cmd ("observer", no_class
,
9669 &observer_mode_1
, _("\
9670 Set whether gdb controls the inferior in observer mode."), _("\
9671 Show whether gdb controls the inferior in observer mode."), _("\
9672 In observer mode, GDB can get data from the inferior, but not\n\
9673 affect its execution. Registers and memory may not be changed,\n\
9674 breakpoints may not be set, and the program cannot be interrupted\n\