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 (target_is_non_stop_p ());
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 ())
4747 /* If already stopping, don't request a stop again.
4748 We just haven't seen the notification yet. */
4749 if (!t
->stop_requested
)
4752 fprintf_unfiltered (gdb_stdlog
,
4753 "infrun: %s executing, "
4755 target_pid_to_str (t
->ptid
).c_str ());
4756 switch_to_thread_no_regs (t
);
4757 target_stop (t
->ptid
);
4758 t
->stop_requested
= 1;
4763 fprintf_unfiltered (gdb_stdlog
,
4764 "infrun: %s executing, "
4765 "already stopping\n",
4766 target_pid_to_str (t
->ptid
).c_str ());
4769 if (t
->stop_requested
)
4775 fprintf_unfiltered (gdb_stdlog
,
4776 "infrun: %s not executing\n",
4777 target_pid_to_str (t
->ptid
).c_str ());
4779 /* The thread may be not executing, but still be
4780 resumed with a pending status to process. */
4788 /* If we find new threads on the second iteration, restart
4789 over. We want to see two iterations in a row with all
4794 wait_one_event event
= wait_one ();
4798 fprintf_unfiltered (gdb_stdlog
,
4799 "infrun: stop_all_threads %s %s\n",
4800 target_waitstatus_to_string (&event
.ws
).c_str (),
4801 target_pid_to_str (event
.ptid
).c_str ());
4804 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4805 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4806 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4807 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4809 /* All resumed threads exited
4810 or one thread/process exited/signalled. */
4814 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4816 t
= add_thread (event
.target
, event
.ptid
);
4818 t
->stop_requested
= 0;
4821 t
->control
.may_range_step
= 0;
4823 /* This may be the first time we see the inferior report
4825 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4826 if (inf
->needs_setup
)
4828 switch_to_thread_no_regs (t
);
4832 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4833 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4835 /* We caught the event that we intended to catch, so
4836 there's no event pending. */
4837 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4838 t
->suspend
.waitstatus_pending_p
= 0;
4840 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4842 /* Add it back to the step-over queue. */
4845 fprintf_unfiltered (gdb_stdlog
,
4846 "infrun: displaced-step of %s "
4847 "canceled: adding back to the "
4848 "step-over queue\n",
4849 target_pid_to_str (t
->ptid
).c_str ());
4851 t
->control
.trap_expected
= 0;
4852 thread_step_over_chain_enqueue (t
);
4857 enum gdb_signal sig
;
4858 struct regcache
*regcache
;
4862 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4864 fprintf_unfiltered (gdb_stdlog
,
4865 "infrun: target_wait %s, saving "
4866 "status for %d.%ld.%ld\n",
4873 /* Record for later. */
4874 save_waitstatus (t
, &event
.ws
);
4876 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4877 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4879 if (displaced_step_fixup (t
, sig
) < 0)
4881 /* Add it back to the step-over queue. */
4882 t
->control
.trap_expected
= 0;
4883 thread_step_over_chain_enqueue (t
);
4886 regcache
= get_thread_regcache (t
);
4887 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4891 fprintf_unfiltered (gdb_stdlog
,
4892 "infrun: saved stop_pc=%s for %s "
4893 "(currently_stepping=%d)\n",
4894 paddress (target_gdbarch (),
4895 t
->suspend
.stop_pc
),
4896 target_pid_to_str (t
->ptid
).c_str (),
4897 currently_stepping (t
));
4905 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4908 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4911 handle_no_resumed (struct execution_control_state
*ecs
)
4913 if (target_can_async_p ())
4920 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4928 /* There were no unwaited-for children left in the target, but,
4929 we're not synchronously waiting for events either. Just
4933 fprintf_unfiltered (gdb_stdlog
,
4934 "infrun: TARGET_WAITKIND_NO_RESUMED "
4935 "(ignoring: bg)\n");
4936 prepare_to_wait (ecs
);
4941 /* Otherwise, if we were running a synchronous execution command, we
4942 may need to cancel it and give the user back the terminal.
4944 In non-stop mode, the target can't tell whether we've already
4945 consumed previous stop events, so it can end up sending us a
4946 no-resumed event like so:
4948 #0 - thread 1 is left stopped
4950 #1 - thread 2 is resumed and hits breakpoint
4951 -> TARGET_WAITKIND_STOPPED
4953 #2 - thread 3 is resumed and exits
4954 this is the last resumed thread, so
4955 -> TARGET_WAITKIND_NO_RESUMED
4957 #3 - gdb processes stop for thread 2 and decides to re-resume
4960 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4961 thread 2 is now resumed, so the event should be ignored.
4963 IOW, if the stop for thread 2 doesn't end a foreground command,
4964 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4965 event. But it could be that the event meant that thread 2 itself
4966 (or whatever other thread was the last resumed thread) exited.
4968 To address this we refresh the thread list and check whether we
4969 have resumed threads _now_. In the example above, this removes
4970 thread 3 from the thread list. If thread 2 was re-resumed, we
4971 ignore this event. If we find no thread resumed, then we cancel
4972 the synchronous command show "no unwaited-for " to the user. */
4973 update_thread_list ();
4975 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4977 if (thread
->executing
4978 || thread
->suspend
.waitstatus_pending_p
)
4980 /* There were no unwaited-for children left in the target at
4981 some point, but there are now. Just ignore. */
4983 fprintf_unfiltered (gdb_stdlog
,
4984 "infrun: TARGET_WAITKIND_NO_RESUMED "
4985 "(ignoring: found resumed)\n");
4986 prepare_to_wait (ecs
);
4991 /* Note however that we may find no resumed thread because the whole
4992 process exited meanwhile (thus updating the thread list results
4993 in an empty thread list). In this case we know we'll be getting
4994 a process exit event shortly. */
4995 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
4997 thread_info
*thread
= any_live_thread_of_inferior (inf
);
5001 fprintf_unfiltered (gdb_stdlog
,
5002 "infrun: TARGET_WAITKIND_NO_RESUMED "
5003 "(expect process exit)\n");
5004 prepare_to_wait (ecs
);
5009 /* Go ahead and report the event. */
5013 /* Given an execution control state that has been freshly filled in by
5014 an event from the inferior, figure out what it means and take
5017 The alternatives are:
5019 1) stop_waiting and return; to really stop and return to the
5022 2) keep_going and return; to wait for the next event (set
5023 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5027 handle_inferior_event (struct execution_control_state
*ecs
)
5029 /* Make sure that all temporary struct value objects that were
5030 created during the handling of the event get deleted at the
5032 scoped_value_mark free_values
;
5034 enum stop_kind stop_soon
;
5037 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5038 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5040 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5042 /* We had an event in the inferior, but we are not interested in
5043 handling it at this level. The lower layers have already
5044 done what needs to be done, if anything.
5046 One of the possible circumstances for this is when the
5047 inferior produces output for the console. The inferior has
5048 not stopped, and we are ignoring the event. Another possible
5049 circumstance is any event which the lower level knows will be
5050 reported multiple times without an intervening resume. */
5051 prepare_to_wait (ecs
);
5055 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5057 prepare_to_wait (ecs
);
5061 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5062 && handle_no_resumed (ecs
))
5065 /* Cache the last target/ptid/waitstatus. */
5066 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5068 /* Always clear state belonging to the previous time we stopped. */
5069 stop_stack_dummy
= STOP_NONE
;
5071 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5073 /* No unwaited-for children left. IOW, all resumed children
5075 stop_print_frame
= 0;
5080 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5081 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5083 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5084 /* If it's a new thread, add it to the thread database. */
5085 if (ecs
->event_thread
== NULL
)
5086 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5088 /* Disable range stepping. If the next step request could use a
5089 range, this will be end up re-enabled then. */
5090 ecs
->event_thread
->control
.may_range_step
= 0;
5093 /* Dependent on valid ECS->EVENT_THREAD. */
5094 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5096 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5097 reinit_frame_cache ();
5099 breakpoint_retire_moribund ();
5101 /* First, distinguish signals caused by the debugger from signals
5102 that have to do with the program's own actions. Note that
5103 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5104 on the operating system version. Here we detect when a SIGILL or
5105 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5106 something similar for SIGSEGV, since a SIGSEGV will be generated
5107 when we're trying to execute a breakpoint instruction on a
5108 non-executable stack. This happens for call dummy breakpoints
5109 for architectures like SPARC that place call dummies on the
5111 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5112 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5113 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5114 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5116 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5118 if (breakpoint_inserted_here_p (regcache
->aspace (),
5119 regcache_read_pc (regcache
)))
5122 fprintf_unfiltered (gdb_stdlog
,
5123 "infrun: Treating signal as SIGTRAP\n");
5124 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5128 /* Mark the non-executing threads accordingly. In all-stop, all
5129 threads of all processes are stopped when we get any event
5130 reported. In non-stop mode, only the event thread stops. */
5134 if (!target_is_non_stop_p ())
5135 mark_ptid
= minus_one_ptid
;
5136 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
5137 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5139 /* If we're handling a process exit in non-stop mode, even
5140 though threads haven't been deleted yet, one would think
5141 that there is nothing to do, as threads of the dead process
5142 will be soon deleted, and threads of any other process were
5143 left running. However, on some targets, threads survive a
5144 process exit event. E.g., for the "checkpoint" command,
5145 when the current checkpoint/fork exits, linux-fork.c
5146 automatically switches to another fork from within
5147 target_mourn_inferior, by associating the same
5148 inferior/thread to another fork. We haven't mourned yet at
5149 this point, but we must mark any threads left in the
5150 process as not-executing so that finish_thread_state marks
5151 them stopped (in the user's perspective) if/when we present
5152 the stop to the user. */
5153 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
5156 mark_ptid
= ecs
->ptid
;
5158 set_executing (ecs
->target
, mark_ptid
, false);
5160 /* Likewise the resumed flag. */
5161 set_resumed (ecs
->target
, mark_ptid
, false);
5164 switch (ecs
->ws
.kind
)
5166 case TARGET_WAITKIND_LOADED
:
5167 context_switch (ecs
);
5168 /* Ignore gracefully during startup of the inferior, as it might
5169 be the shell which has just loaded some objects, otherwise
5170 add the symbols for the newly loaded objects. Also ignore at
5171 the beginning of an attach or remote session; we will query
5172 the full list of libraries once the connection is
5175 stop_soon
= get_inferior_stop_soon (ecs
);
5176 if (stop_soon
== NO_STOP_QUIETLY
)
5178 struct regcache
*regcache
;
5180 regcache
= get_thread_regcache (ecs
->event_thread
);
5182 handle_solib_event ();
5184 ecs
->event_thread
->control
.stop_bpstat
5185 = bpstat_stop_status (regcache
->aspace (),
5186 ecs
->event_thread
->suspend
.stop_pc
,
5187 ecs
->event_thread
, &ecs
->ws
);
5189 if (handle_stop_requested (ecs
))
5192 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5194 /* A catchpoint triggered. */
5195 process_event_stop_test (ecs
);
5199 /* If requested, stop when the dynamic linker notifies
5200 gdb of events. This allows the user to get control
5201 and place breakpoints in initializer routines for
5202 dynamically loaded objects (among other things). */
5203 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5204 if (stop_on_solib_events
)
5206 /* Make sure we print "Stopped due to solib-event" in
5208 stop_print_frame
= 1;
5215 /* If we are skipping through a shell, or through shared library
5216 loading that we aren't interested in, resume the program. If
5217 we're running the program normally, also resume. */
5218 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5220 /* Loading of shared libraries might have changed breakpoint
5221 addresses. Make sure new breakpoints are inserted. */
5222 if (stop_soon
== NO_STOP_QUIETLY
)
5223 insert_breakpoints ();
5224 resume (GDB_SIGNAL_0
);
5225 prepare_to_wait (ecs
);
5229 /* But stop if we're attaching or setting up a remote
5231 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5232 || stop_soon
== STOP_QUIETLY_REMOTE
)
5235 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5240 internal_error (__FILE__
, __LINE__
,
5241 _("unhandled stop_soon: %d"), (int) stop_soon
);
5243 case TARGET_WAITKIND_SPURIOUS
:
5244 if (handle_stop_requested (ecs
))
5246 context_switch (ecs
);
5247 resume (GDB_SIGNAL_0
);
5248 prepare_to_wait (ecs
);
5251 case TARGET_WAITKIND_THREAD_CREATED
:
5252 if (handle_stop_requested (ecs
))
5254 context_switch (ecs
);
5255 if (!switch_back_to_stepped_thread (ecs
))
5259 case TARGET_WAITKIND_EXITED
:
5260 case TARGET_WAITKIND_SIGNALLED
:
5261 inferior_ptid
= ecs
->ptid
;
5262 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5263 set_current_program_space (current_inferior ()->pspace
);
5264 handle_vfork_child_exec_or_exit (0);
5265 target_terminal::ours (); /* Must do this before mourn anyway. */
5267 /* Clearing any previous state of convenience variables. */
5268 clear_exit_convenience_vars ();
5270 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5272 /* Record the exit code in the convenience variable $_exitcode, so
5273 that the user can inspect this again later. */
5274 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5275 (LONGEST
) ecs
->ws
.value
.integer
);
5277 /* Also record this in the inferior itself. */
5278 current_inferior ()->has_exit_code
= 1;
5279 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5281 /* Support the --return-child-result option. */
5282 return_child_result_value
= ecs
->ws
.value
.integer
;
5284 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5288 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5290 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5292 /* Set the value of the internal variable $_exitsignal,
5293 which holds the signal uncaught by the inferior. */
5294 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5295 gdbarch_gdb_signal_to_target (gdbarch
,
5296 ecs
->ws
.value
.sig
));
5300 /* We don't have access to the target's method used for
5301 converting between signal numbers (GDB's internal
5302 representation <-> target's representation).
5303 Therefore, we cannot do a good job at displaying this
5304 information to the user. It's better to just warn
5305 her about it (if infrun debugging is enabled), and
5308 fprintf_filtered (gdb_stdlog
, _("\
5309 Cannot fill $_exitsignal with the correct signal number.\n"));
5312 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5315 gdb_flush (gdb_stdout
);
5316 target_mourn_inferior (inferior_ptid
);
5317 stop_print_frame
= 0;
5321 case TARGET_WAITKIND_FORKED
:
5322 case TARGET_WAITKIND_VFORKED
:
5323 /* Check whether the inferior is displaced stepping. */
5325 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5326 struct gdbarch
*gdbarch
= regcache
->arch ();
5328 /* If checking displaced stepping is supported, and thread
5329 ecs->ptid is displaced stepping. */
5330 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5332 struct inferior
*parent_inf
5333 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5334 struct regcache
*child_regcache
;
5335 CORE_ADDR parent_pc
;
5337 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5339 struct displaced_step_inferior_state
*displaced
5340 = get_displaced_stepping_state (parent_inf
);
5342 /* Restore scratch pad for child process. */
5343 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5346 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5347 indicating that the displaced stepping of syscall instruction
5348 has been done. Perform cleanup for parent process here. Note
5349 that this operation also cleans up the child process for vfork,
5350 because their pages are shared. */
5351 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5352 /* Start a new step-over in another thread if there's one
5356 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5357 the child's PC is also within the scratchpad. Set the child's PC
5358 to the parent's PC value, which has already been fixed up.
5359 FIXME: we use the parent's aspace here, although we're touching
5360 the child, because the child hasn't been added to the inferior
5361 list yet at this point. */
5364 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5365 ecs
->ws
.value
.related_pid
,
5367 parent_inf
->aspace
);
5368 /* Read PC value of parent process. */
5369 parent_pc
= regcache_read_pc (regcache
);
5371 if (debug_displaced
)
5372 fprintf_unfiltered (gdb_stdlog
,
5373 "displaced: write child pc from %s to %s\n",
5375 regcache_read_pc (child_regcache
)),
5376 paddress (gdbarch
, parent_pc
));
5378 regcache_write_pc (child_regcache
, parent_pc
);
5382 context_switch (ecs
);
5384 /* Immediately detach breakpoints from the child before there's
5385 any chance of letting the user delete breakpoints from the
5386 breakpoint lists. If we don't do this early, it's easy to
5387 leave left over traps in the child, vis: "break foo; catch
5388 fork; c; <fork>; del; c; <child calls foo>". We only follow
5389 the fork on the last `continue', and by that time the
5390 breakpoint at "foo" is long gone from the breakpoint table.
5391 If we vforked, then we don't need to unpatch here, since both
5392 parent and child are sharing the same memory pages; we'll
5393 need to unpatch at follow/detach time instead to be certain
5394 that new breakpoints added between catchpoint hit time and
5395 vfork follow are detached. */
5396 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5398 /* This won't actually modify the breakpoint list, but will
5399 physically remove the breakpoints from the child. */
5400 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5403 delete_just_stopped_threads_single_step_breakpoints ();
5405 /* In case the event is caught by a catchpoint, remember that
5406 the event is to be followed at the next resume of the thread,
5407 and not immediately. */
5408 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5410 ecs
->event_thread
->suspend
.stop_pc
5411 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5413 ecs
->event_thread
->control
.stop_bpstat
5414 = bpstat_stop_status (get_current_regcache ()->aspace (),
5415 ecs
->event_thread
->suspend
.stop_pc
,
5416 ecs
->event_thread
, &ecs
->ws
);
5418 if (handle_stop_requested (ecs
))
5421 /* If no catchpoint triggered for this, then keep going. Note
5422 that we're interested in knowing the bpstat actually causes a
5423 stop, not just if it may explain the signal. Software
5424 watchpoints, for example, always appear in the bpstat. */
5425 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5428 = (follow_fork_mode_string
== follow_fork_mode_child
);
5430 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5432 process_stratum_target
*targ
5433 = ecs
->event_thread
->inf
->process_target ();
5435 bool should_resume
= follow_fork ();
5437 /* Note that one of these may be an invalid pointer,
5438 depending on detach_fork. */
5439 thread_info
*parent
= ecs
->event_thread
;
5441 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5443 /* At this point, the parent is marked running, and the
5444 child is marked stopped. */
5446 /* If not resuming the parent, mark it stopped. */
5447 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5448 parent
->set_running (false);
5450 /* If resuming the child, mark it running. */
5451 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5452 child
->set_running (true);
5454 /* In non-stop mode, also resume the other branch. */
5455 if (!detach_fork
&& (non_stop
5456 || (sched_multi
&& target_is_non_stop_p ())))
5459 switch_to_thread (parent
);
5461 switch_to_thread (child
);
5463 ecs
->event_thread
= inferior_thread ();
5464 ecs
->ptid
= inferior_ptid
;
5469 switch_to_thread (child
);
5471 switch_to_thread (parent
);
5473 ecs
->event_thread
= inferior_thread ();
5474 ecs
->ptid
= inferior_ptid
;
5482 process_event_stop_test (ecs
);
5485 case TARGET_WAITKIND_VFORK_DONE
:
5486 /* Done with the shared memory region. Re-insert breakpoints in
5487 the parent, and keep going. */
5489 context_switch (ecs
);
5491 current_inferior ()->waiting_for_vfork_done
= 0;
5492 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5494 if (handle_stop_requested (ecs
))
5497 /* This also takes care of reinserting breakpoints in the
5498 previously locked inferior. */
5502 case TARGET_WAITKIND_EXECD
:
5504 /* Note we can't read registers yet (the stop_pc), because we
5505 don't yet know the inferior's post-exec architecture.
5506 'stop_pc' is explicitly read below instead. */
5507 switch_to_thread_no_regs (ecs
->event_thread
);
5509 /* Do whatever is necessary to the parent branch of the vfork. */
5510 handle_vfork_child_exec_or_exit (1);
5512 /* This causes the eventpoints and symbol table to be reset.
5513 Must do this now, before trying to determine whether to
5515 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5517 /* In follow_exec we may have deleted the original thread and
5518 created a new one. Make sure that the event thread is the
5519 execd thread for that case (this is a nop otherwise). */
5520 ecs
->event_thread
= inferior_thread ();
5522 ecs
->event_thread
->suspend
.stop_pc
5523 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5525 ecs
->event_thread
->control
.stop_bpstat
5526 = bpstat_stop_status (get_current_regcache ()->aspace (),
5527 ecs
->event_thread
->suspend
.stop_pc
,
5528 ecs
->event_thread
, &ecs
->ws
);
5530 /* Note that this may be referenced from inside
5531 bpstat_stop_status above, through inferior_has_execd. */
5532 xfree (ecs
->ws
.value
.execd_pathname
);
5533 ecs
->ws
.value
.execd_pathname
= NULL
;
5535 if (handle_stop_requested (ecs
))
5538 /* If no catchpoint triggered for this, then keep going. */
5539 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5541 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5545 process_event_stop_test (ecs
);
5548 /* Be careful not to try to gather much state about a thread
5549 that's in a syscall. It's frequently a losing proposition. */
5550 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5551 /* Getting the current syscall number. */
5552 if (handle_syscall_event (ecs
) == 0)
5553 process_event_stop_test (ecs
);
5556 /* Before examining the threads further, step this thread to
5557 get it entirely out of the syscall. (We get notice of the
5558 event when the thread is just on the verge of exiting a
5559 syscall. Stepping one instruction seems to get it back
5561 case TARGET_WAITKIND_SYSCALL_RETURN
:
5562 if (handle_syscall_event (ecs
) == 0)
5563 process_event_stop_test (ecs
);
5566 case TARGET_WAITKIND_STOPPED
:
5567 handle_signal_stop (ecs
);
5570 case TARGET_WAITKIND_NO_HISTORY
:
5571 /* Reverse execution: target ran out of history info. */
5573 /* Switch to the stopped thread. */
5574 context_switch (ecs
);
5576 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5578 delete_just_stopped_threads_single_step_breakpoints ();
5579 ecs
->event_thread
->suspend
.stop_pc
5580 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5582 if (handle_stop_requested (ecs
))
5585 gdb::observers::no_history
.notify ();
5591 /* Restart threads back to what they were trying to do back when we
5592 paused them for an in-line step-over. The EVENT_THREAD thread is
5596 restart_threads (struct thread_info
*event_thread
)
5598 /* In case the instruction just stepped spawned a new thread. */
5599 update_thread_list ();
5601 for (thread_info
*tp
: all_non_exited_threads ())
5603 switch_to_thread_no_regs (tp
);
5605 if (tp
== event_thread
)
5608 fprintf_unfiltered (gdb_stdlog
,
5609 "infrun: restart threads: "
5610 "[%s] is event thread\n",
5611 target_pid_to_str (tp
->ptid
).c_str ());
5615 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5618 fprintf_unfiltered (gdb_stdlog
,
5619 "infrun: restart threads: "
5620 "[%s] not meant to be running\n",
5621 target_pid_to_str (tp
->ptid
).c_str ());
5628 fprintf_unfiltered (gdb_stdlog
,
5629 "infrun: restart threads: [%s] resumed\n",
5630 target_pid_to_str (tp
->ptid
).c_str ());
5631 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5635 if (thread_is_in_step_over_chain (tp
))
5638 fprintf_unfiltered (gdb_stdlog
,
5639 "infrun: restart threads: "
5640 "[%s] needs step-over\n",
5641 target_pid_to_str (tp
->ptid
).c_str ());
5642 gdb_assert (!tp
->resumed
);
5647 if (tp
->suspend
.waitstatus_pending_p
)
5650 fprintf_unfiltered (gdb_stdlog
,
5651 "infrun: restart threads: "
5652 "[%s] has pending status\n",
5653 target_pid_to_str (tp
->ptid
).c_str ());
5658 gdb_assert (!tp
->stop_requested
);
5660 /* If some thread needs to start a step-over at this point, it
5661 should still be in the step-over queue, and thus skipped
5663 if (thread_still_needs_step_over (tp
))
5665 internal_error (__FILE__
, __LINE__
,
5666 "thread [%s] needs a step-over, but not in "
5667 "step-over queue\n",
5668 target_pid_to_str (tp
->ptid
).c_str ());
5671 if (currently_stepping (tp
))
5674 fprintf_unfiltered (gdb_stdlog
,
5675 "infrun: restart threads: [%s] was stepping\n",
5676 target_pid_to_str (tp
->ptid
).c_str ());
5677 keep_going_stepped_thread (tp
);
5681 struct execution_control_state ecss
;
5682 struct execution_control_state
*ecs
= &ecss
;
5685 fprintf_unfiltered (gdb_stdlog
,
5686 "infrun: restart threads: [%s] continuing\n",
5687 target_pid_to_str (tp
->ptid
).c_str ());
5688 reset_ecs (ecs
, tp
);
5689 switch_to_thread (tp
);
5690 keep_going_pass_signal (ecs
);
5695 /* Callback for iterate_over_threads. Find a resumed thread that has
5696 a pending waitstatus. */
5699 resumed_thread_with_pending_status (struct thread_info
*tp
,
5703 && tp
->suspend
.waitstatus_pending_p
);
5706 /* Called when we get an event that may finish an in-line or
5707 out-of-line (displaced stepping) step-over started previously.
5708 Return true if the event is processed and we should go back to the
5709 event loop; false if the caller should continue processing the
5713 finish_step_over (struct execution_control_state
*ecs
)
5715 int had_step_over_info
;
5717 displaced_step_fixup (ecs
->event_thread
,
5718 ecs
->event_thread
->suspend
.stop_signal
);
5720 had_step_over_info
= step_over_info_valid_p ();
5722 if (had_step_over_info
)
5724 /* If we're stepping over a breakpoint with all threads locked,
5725 then only the thread that was stepped should be reporting
5727 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5729 clear_step_over_info ();
5732 if (!target_is_non_stop_p ())
5735 /* Start a new step-over in another thread if there's one that
5739 /* If we were stepping over a breakpoint before, and haven't started
5740 a new in-line step-over sequence, then restart all other threads
5741 (except the event thread). We can't do this in all-stop, as then
5742 e.g., we wouldn't be able to issue any other remote packet until
5743 these other threads stop. */
5744 if (had_step_over_info
&& !step_over_info_valid_p ())
5746 struct thread_info
*pending
;
5748 /* If we only have threads with pending statuses, the restart
5749 below won't restart any thread and so nothing re-inserts the
5750 breakpoint we just stepped over. But we need it inserted
5751 when we later process the pending events, otherwise if
5752 another thread has a pending event for this breakpoint too,
5753 we'd discard its event (because the breakpoint that
5754 originally caused the event was no longer inserted). */
5755 context_switch (ecs
);
5756 insert_breakpoints ();
5758 restart_threads (ecs
->event_thread
);
5760 /* If we have events pending, go through handle_inferior_event
5761 again, picking up a pending event at random. This avoids
5762 thread starvation. */
5764 /* But not if we just stepped over a watchpoint in order to let
5765 the instruction execute so we can evaluate its expression.
5766 The set of watchpoints that triggered is recorded in the
5767 breakpoint objects themselves (see bp->watchpoint_triggered).
5768 If we processed another event first, that other event could
5769 clobber this info. */
5770 if (ecs
->event_thread
->stepping_over_watchpoint
)
5773 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5775 if (pending
!= NULL
)
5777 struct thread_info
*tp
= ecs
->event_thread
;
5778 struct regcache
*regcache
;
5782 fprintf_unfiltered (gdb_stdlog
,
5783 "infrun: found resumed threads with "
5784 "pending events, saving status\n");
5787 gdb_assert (pending
!= tp
);
5789 /* Record the event thread's event for later. */
5790 save_waitstatus (tp
, &ecs
->ws
);
5791 /* This was cleared early, by handle_inferior_event. Set it
5792 so this pending event is considered by
5796 gdb_assert (!tp
->executing
);
5798 regcache
= get_thread_regcache (tp
);
5799 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5803 fprintf_unfiltered (gdb_stdlog
,
5804 "infrun: saved stop_pc=%s for %s "
5805 "(currently_stepping=%d)\n",
5806 paddress (target_gdbarch (),
5807 tp
->suspend
.stop_pc
),
5808 target_pid_to_str (tp
->ptid
).c_str (),
5809 currently_stepping (tp
));
5812 /* This in-line step-over finished; clear this so we won't
5813 start a new one. This is what handle_signal_stop would
5814 do, if we returned false. */
5815 tp
->stepping_over_breakpoint
= 0;
5817 /* Wake up the event loop again. */
5818 mark_async_event_handler (infrun_async_inferior_event_token
);
5820 prepare_to_wait (ecs
);
5828 /* Come here when the program has stopped with a signal. */
5831 handle_signal_stop (struct execution_control_state
*ecs
)
5833 struct frame_info
*frame
;
5834 struct gdbarch
*gdbarch
;
5835 int stopped_by_watchpoint
;
5836 enum stop_kind stop_soon
;
5839 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5841 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5843 /* Do we need to clean up the state of a thread that has
5844 completed a displaced single-step? (Doing so usually affects
5845 the PC, so do it here, before we set stop_pc.) */
5846 if (finish_step_over (ecs
))
5849 /* If we either finished a single-step or hit a breakpoint, but
5850 the user wanted this thread to be stopped, pretend we got a
5851 SIG0 (generic unsignaled stop). */
5852 if (ecs
->event_thread
->stop_requested
5853 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5854 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5856 ecs
->event_thread
->suspend
.stop_pc
5857 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5861 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5862 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5864 switch_to_thread (ecs
->event_thread
);
5866 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5867 paddress (reg_gdbarch
,
5868 ecs
->event_thread
->suspend
.stop_pc
));
5869 if (target_stopped_by_watchpoint ())
5873 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5875 if (target_stopped_data_address (current_top_target (), &addr
))
5876 fprintf_unfiltered (gdb_stdlog
,
5877 "infrun: stopped data address = %s\n",
5878 paddress (reg_gdbarch
, addr
));
5880 fprintf_unfiltered (gdb_stdlog
,
5881 "infrun: (no data address available)\n");
5885 /* This is originated from start_remote(), start_inferior() and
5886 shared libraries hook functions. */
5887 stop_soon
= get_inferior_stop_soon (ecs
);
5888 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5890 context_switch (ecs
);
5892 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5893 stop_print_frame
= 1;
5898 /* This originates from attach_command(). We need to overwrite
5899 the stop_signal here, because some kernels don't ignore a
5900 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5901 See more comments in inferior.h. On the other hand, if we
5902 get a non-SIGSTOP, report it to the user - assume the backend
5903 will handle the SIGSTOP if it should show up later.
5905 Also consider that the attach is complete when we see a
5906 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5907 target extended-remote report it instead of a SIGSTOP
5908 (e.g. gdbserver). We already rely on SIGTRAP being our
5909 signal, so this is no exception.
5911 Also consider that the attach is complete when we see a
5912 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5913 the target to stop all threads of the inferior, in case the
5914 low level attach operation doesn't stop them implicitly. If
5915 they weren't stopped implicitly, then the stub will report a
5916 GDB_SIGNAL_0, meaning: stopped for no particular reason
5917 other than GDB's request. */
5918 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5919 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5920 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5921 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5923 stop_print_frame
= 1;
5925 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5929 /* See if something interesting happened to the non-current thread. If
5930 so, then switch to that thread. */
5931 if (ecs
->ptid
!= inferior_ptid
)
5934 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5936 context_switch (ecs
);
5938 if (deprecated_context_hook
)
5939 deprecated_context_hook (ecs
->event_thread
->global_num
);
5942 /* At this point, get hold of the now-current thread's frame. */
5943 frame
= get_current_frame ();
5944 gdbarch
= get_frame_arch (frame
);
5946 /* Pull the single step breakpoints out of the target. */
5947 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5949 struct regcache
*regcache
;
5952 regcache
= get_thread_regcache (ecs
->event_thread
);
5953 const address_space
*aspace
= regcache
->aspace ();
5955 pc
= regcache_read_pc (regcache
);
5957 /* However, before doing so, if this single-step breakpoint was
5958 actually for another thread, set this thread up for moving
5960 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5963 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5967 fprintf_unfiltered (gdb_stdlog
,
5968 "infrun: [%s] hit another thread's "
5969 "single-step breakpoint\n",
5970 target_pid_to_str (ecs
->ptid
).c_str ());
5972 ecs
->hit_singlestep_breakpoint
= 1;
5979 fprintf_unfiltered (gdb_stdlog
,
5980 "infrun: [%s] hit its "
5981 "single-step breakpoint\n",
5982 target_pid_to_str (ecs
->ptid
).c_str ());
5986 delete_just_stopped_threads_single_step_breakpoints ();
5988 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5989 && ecs
->event_thread
->control
.trap_expected
5990 && ecs
->event_thread
->stepping_over_watchpoint
)
5991 stopped_by_watchpoint
= 0;
5993 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5995 /* If necessary, step over this watchpoint. We'll be back to display
5997 if (stopped_by_watchpoint
5998 && (target_have_steppable_watchpoint
5999 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6001 /* At this point, we are stopped at an instruction which has
6002 attempted to write to a piece of memory under control of
6003 a watchpoint. The instruction hasn't actually executed
6004 yet. If we were to evaluate the watchpoint expression
6005 now, we would get the old value, and therefore no change
6006 would seem to have occurred.
6008 In order to make watchpoints work `right', we really need
6009 to complete the memory write, and then evaluate the
6010 watchpoint expression. We do this by single-stepping the
6013 It may not be necessary to disable the watchpoint to step over
6014 it. For example, the PA can (with some kernel cooperation)
6015 single step over a watchpoint without disabling the watchpoint.
6017 It is far more common to need to disable a watchpoint to step
6018 the inferior over it. If we have non-steppable watchpoints,
6019 we must disable the current watchpoint; it's simplest to
6020 disable all watchpoints.
6022 Any breakpoint at PC must also be stepped over -- if there's
6023 one, it will have already triggered before the watchpoint
6024 triggered, and we either already reported it to the user, or
6025 it didn't cause a stop and we called keep_going. In either
6026 case, if there was a breakpoint at PC, we must be trying to
6028 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6033 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6034 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6035 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6036 ecs
->event_thread
->control
.stop_step
= 0;
6037 stop_print_frame
= 1;
6038 stopped_by_random_signal
= 0;
6039 bpstat stop_chain
= NULL
;
6041 /* Hide inlined functions starting here, unless we just performed stepi or
6042 nexti. After stepi and nexti, always show the innermost frame (not any
6043 inline function call sites). */
6044 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6046 const address_space
*aspace
6047 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6049 /* skip_inline_frames is expensive, so we avoid it if we can
6050 determine that the address is one where functions cannot have
6051 been inlined. This improves performance with inferiors that
6052 load a lot of shared libraries, because the solib event
6053 breakpoint is defined as the address of a function (i.e. not
6054 inline). Note that we have to check the previous PC as well
6055 as the current one to catch cases when we have just
6056 single-stepped off a breakpoint prior to reinstating it.
6057 Note that we're assuming that the code we single-step to is
6058 not inline, but that's not definitive: there's nothing
6059 preventing the event breakpoint function from containing
6060 inlined code, and the single-step ending up there. If the
6061 user had set a breakpoint on that inlined code, the missing
6062 skip_inline_frames call would break things. Fortunately
6063 that's an extremely unlikely scenario. */
6064 if (!pc_at_non_inline_function (aspace
,
6065 ecs
->event_thread
->suspend
.stop_pc
,
6067 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6068 && ecs
->event_thread
->control
.trap_expected
6069 && pc_at_non_inline_function (aspace
,
6070 ecs
->event_thread
->prev_pc
,
6073 stop_chain
= build_bpstat_chain (aspace
,
6074 ecs
->event_thread
->suspend
.stop_pc
,
6076 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6078 /* Re-fetch current thread's frame in case that invalidated
6080 frame
= get_current_frame ();
6081 gdbarch
= get_frame_arch (frame
);
6085 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6086 && ecs
->event_thread
->control
.trap_expected
6087 && gdbarch_single_step_through_delay_p (gdbarch
)
6088 && currently_stepping (ecs
->event_thread
))
6090 /* We're trying to step off a breakpoint. Turns out that we're
6091 also on an instruction that needs to be stepped multiple
6092 times before it's been fully executing. E.g., architectures
6093 with a delay slot. It needs to be stepped twice, once for
6094 the instruction and once for the delay slot. */
6095 int step_through_delay
6096 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6098 if (debug_infrun
&& step_through_delay
)
6099 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6100 if (ecs
->event_thread
->control
.step_range_end
== 0
6101 && step_through_delay
)
6103 /* The user issued a continue when stopped at a breakpoint.
6104 Set up for another trap and get out of here. */
6105 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6109 else if (step_through_delay
)
6111 /* The user issued a step when stopped at a breakpoint.
6112 Maybe we should stop, maybe we should not - the delay
6113 slot *might* correspond to a line of source. In any
6114 case, don't decide that here, just set
6115 ecs->stepping_over_breakpoint, making sure we
6116 single-step again before breakpoints are re-inserted. */
6117 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6121 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6122 handles this event. */
6123 ecs
->event_thread
->control
.stop_bpstat
6124 = bpstat_stop_status (get_current_regcache ()->aspace (),
6125 ecs
->event_thread
->suspend
.stop_pc
,
6126 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6128 /* Following in case break condition called a
6130 stop_print_frame
= 1;
6132 /* This is where we handle "moribund" watchpoints. Unlike
6133 software breakpoints traps, hardware watchpoint traps are
6134 always distinguishable from random traps. If no high-level
6135 watchpoint is associated with the reported stop data address
6136 anymore, then the bpstat does not explain the signal ---
6137 simply make sure to ignore it if `stopped_by_watchpoint' is
6141 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6142 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6144 && stopped_by_watchpoint
)
6145 fprintf_unfiltered (gdb_stdlog
,
6146 "infrun: no user watchpoint explains "
6147 "watchpoint SIGTRAP, ignoring\n");
6149 /* NOTE: cagney/2003-03-29: These checks for a random signal
6150 at one stage in the past included checks for an inferior
6151 function call's call dummy's return breakpoint. The original
6152 comment, that went with the test, read:
6154 ``End of a stack dummy. Some systems (e.g. Sony news) give
6155 another signal besides SIGTRAP, so check here as well as
6158 If someone ever tries to get call dummys on a
6159 non-executable stack to work (where the target would stop
6160 with something like a SIGSEGV), then those tests might need
6161 to be re-instated. Given, however, that the tests were only
6162 enabled when momentary breakpoints were not being used, I
6163 suspect that it won't be the case.
6165 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6166 be necessary for call dummies on a non-executable stack on
6169 /* See if the breakpoints module can explain the signal. */
6171 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6172 ecs
->event_thread
->suspend
.stop_signal
);
6174 /* Maybe this was a trap for a software breakpoint that has since
6176 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6178 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6179 ecs
->event_thread
->suspend
.stop_pc
))
6181 struct regcache
*regcache
;
6184 /* Re-adjust PC to what the program would see if GDB was not
6186 regcache
= get_thread_regcache (ecs
->event_thread
);
6187 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6190 gdb::optional
<scoped_restore_tmpl
<int>>
6191 restore_operation_disable
;
6193 if (record_full_is_used ())
6194 restore_operation_disable
.emplace
6195 (record_full_gdb_operation_disable_set ());
6197 regcache_write_pc (regcache
,
6198 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6203 /* A delayed software breakpoint event. Ignore the trap. */
6205 fprintf_unfiltered (gdb_stdlog
,
6206 "infrun: delayed software breakpoint "
6207 "trap, ignoring\n");
6212 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6213 has since been removed. */
6214 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6216 /* A delayed hardware breakpoint event. Ignore the trap. */
6218 fprintf_unfiltered (gdb_stdlog
,
6219 "infrun: delayed hardware breakpoint/watchpoint "
6220 "trap, ignoring\n");
6224 /* If not, perhaps stepping/nexting can. */
6226 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6227 && currently_stepping (ecs
->event_thread
));
6229 /* Perhaps the thread hit a single-step breakpoint of _another_
6230 thread. Single-step breakpoints are transparent to the
6231 breakpoints module. */
6233 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6235 /* No? Perhaps we got a moribund watchpoint. */
6237 random_signal
= !stopped_by_watchpoint
;
6239 /* Always stop if the user explicitly requested this thread to
6241 if (ecs
->event_thread
->stop_requested
)
6245 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6248 /* For the program's own signals, act according to
6249 the signal handling tables. */
6253 /* Signal not for debugging purposes. */
6254 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6255 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6258 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6259 gdb_signal_to_symbol_string (stop_signal
));
6261 stopped_by_random_signal
= 1;
6263 /* Always stop on signals if we're either just gaining control
6264 of the program, or the user explicitly requested this thread
6265 to remain stopped. */
6266 if (stop_soon
!= NO_STOP_QUIETLY
6267 || ecs
->event_thread
->stop_requested
6269 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6275 /* Notify observers the signal has "handle print" set. Note we
6276 returned early above if stopping; normal_stop handles the
6277 printing in that case. */
6278 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6280 /* The signal table tells us to print about this signal. */
6281 target_terminal::ours_for_output ();
6282 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6283 target_terminal::inferior ();
6286 /* Clear the signal if it should not be passed. */
6287 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6288 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6290 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6291 && ecs
->event_thread
->control
.trap_expected
6292 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6294 /* We were just starting a new sequence, attempting to
6295 single-step off of a breakpoint and expecting a SIGTRAP.
6296 Instead this signal arrives. This signal will take us out
6297 of the stepping range so GDB needs to remember to, when
6298 the signal handler returns, resume stepping off that
6300 /* To simplify things, "continue" is forced to use the same
6301 code paths as single-step - set a breakpoint at the
6302 signal return address and then, once hit, step off that
6305 fprintf_unfiltered (gdb_stdlog
,
6306 "infrun: signal arrived while stepping over "
6309 insert_hp_step_resume_breakpoint_at_frame (frame
);
6310 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6311 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6312 ecs
->event_thread
->control
.trap_expected
= 0;
6314 /* If we were nexting/stepping some other thread, switch to
6315 it, so that we don't continue it, losing control. */
6316 if (!switch_back_to_stepped_thread (ecs
))
6321 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6322 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6324 || ecs
->event_thread
->control
.step_range_end
== 1)
6325 && frame_id_eq (get_stack_frame_id (frame
),
6326 ecs
->event_thread
->control
.step_stack_frame_id
)
6327 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6329 /* The inferior is about to take a signal that will take it
6330 out of the single step range. Set a breakpoint at the
6331 current PC (which is presumably where the signal handler
6332 will eventually return) and then allow the inferior to
6335 Note that this is only needed for a signal delivered
6336 while in the single-step range. Nested signals aren't a
6337 problem as they eventually all return. */
6339 fprintf_unfiltered (gdb_stdlog
,
6340 "infrun: signal may take us out of "
6341 "single-step range\n");
6343 clear_step_over_info ();
6344 insert_hp_step_resume_breakpoint_at_frame (frame
);
6345 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6346 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6347 ecs
->event_thread
->control
.trap_expected
= 0;
6352 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6353 when either there's a nested signal, or when there's a
6354 pending signal enabled just as the signal handler returns
6355 (leaving the inferior at the step-resume-breakpoint without
6356 actually executing it). Either way continue until the
6357 breakpoint is really hit. */
6359 if (!switch_back_to_stepped_thread (ecs
))
6362 fprintf_unfiltered (gdb_stdlog
,
6363 "infrun: random signal, keep going\n");
6370 process_event_stop_test (ecs
);
6373 /* Come here when we've got some debug event / signal we can explain
6374 (IOW, not a random signal), and test whether it should cause a
6375 stop, or whether we should resume the inferior (transparently).
6376 E.g., could be a breakpoint whose condition evaluates false; we
6377 could be still stepping within the line; etc. */
6380 process_event_stop_test (struct execution_control_state
*ecs
)
6382 struct symtab_and_line stop_pc_sal
;
6383 struct frame_info
*frame
;
6384 struct gdbarch
*gdbarch
;
6385 CORE_ADDR jmp_buf_pc
;
6386 struct bpstat_what what
;
6388 /* Handle cases caused by hitting a breakpoint. */
6390 frame
= get_current_frame ();
6391 gdbarch
= get_frame_arch (frame
);
6393 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6395 if (what
.call_dummy
)
6397 stop_stack_dummy
= what
.call_dummy
;
6400 /* A few breakpoint types have callbacks associated (e.g.,
6401 bp_jit_event). Run them now. */
6402 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6404 /* If we hit an internal event that triggers symbol changes, the
6405 current frame will be invalidated within bpstat_what (e.g., if we
6406 hit an internal solib event). Re-fetch it. */
6407 frame
= get_current_frame ();
6408 gdbarch
= get_frame_arch (frame
);
6410 switch (what
.main_action
)
6412 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6413 /* If we hit the breakpoint at longjmp while stepping, we
6414 install a momentary breakpoint at the target of the
6418 fprintf_unfiltered (gdb_stdlog
,
6419 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6421 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6423 if (what
.is_longjmp
)
6425 struct value
*arg_value
;
6427 /* If we set the longjmp breakpoint via a SystemTap probe,
6428 then use it to extract the arguments. The destination PC
6429 is the third argument to the probe. */
6430 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6433 jmp_buf_pc
= value_as_address (arg_value
);
6434 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6436 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6437 || !gdbarch_get_longjmp_target (gdbarch
,
6438 frame
, &jmp_buf_pc
))
6441 fprintf_unfiltered (gdb_stdlog
,
6442 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6443 "(!gdbarch_get_longjmp_target)\n");
6448 /* Insert a breakpoint at resume address. */
6449 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6452 check_exception_resume (ecs
, frame
);
6456 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6458 struct frame_info
*init_frame
;
6460 /* There are several cases to consider.
6462 1. The initiating frame no longer exists. In this case we
6463 must stop, because the exception or longjmp has gone too
6466 2. The initiating frame exists, and is the same as the
6467 current frame. We stop, because the exception or longjmp
6470 3. The initiating frame exists and is different from the
6471 current frame. This means the exception or longjmp has
6472 been caught beneath the initiating frame, so keep going.
6474 4. longjmp breakpoint has been placed just to protect
6475 against stale dummy frames and user is not interested in
6476 stopping around longjmps. */
6479 fprintf_unfiltered (gdb_stdlog
,
6480 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6482 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6484 delete_exception_resume_breakpoint (ecs
->event_thread
);
6486 if (what
.is_longjmp
)
6488 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6490 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6498 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6502 struct frame_id current_id
6503 = get_frame_id (get_current_frame ());
6504 if (frame_id_eq (current_id
,
6505 ecs
->event_thread
->initiating_frame
))
6507 /* Case 2. Fall through. */
6517 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6519 delete_step_resume_breakpoint (ecs
->event_thread
);
6521 end_stepping_range (ecs
);
6525 case BPSTAT_WHAT_SINGLE
:
6527 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6528 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6529 /* Still need to check other stuff, at least the case where we
6530 are stepping and step out of the right range. */
6533 case BPSTAT_WHAT_STEP_RESUME
:
6535 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6537 delete_step_resume_breakpoint (ecs
->event_thread
);
6538 if (ecs
->event_thread
->control
.proceed_to_finish
6539 && execution_direction
== EXEC_REVERSE
)
6541 struct thread_info
*tp
= ecs
->event_thread
;
6543 /* We are finishing a function in reverse, and just hit the
6544 step-resume breakpoint at the start address of the
6545 function, and we're almost there -- just need to back up
6546 by one more single-step, which should take us back to the
6548 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6552 fill_in_stop_func (gdbarch
, ecs
);
6553 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6554 && execution_direction
== EXEC_REVERSE
)
6556 /* We are stepping over a function call in reverse, and just
6557 hit the step-resume breakpoint at the start address of
6558 the function. Go back to single-stepping, which should
6559 take us back to the function call. */
6560 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6566 case BPSTAT_WHAT_STOP_NOISY
:
6568 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6569 stop_print_frame
= 1;
6571 /* Assume the thread stopped for a breapoint. We'll still check
6572 whether a/the breakpoint is there when the thread is next
6574 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6579 case BPSTAT_WHAT_STOP_SILENT
:
6581 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6582 stop_print_frame
= 0;
6584 /* Assume the thread stopped for a breapoint. We'll still check
6585 whether a/the breakpoint is there when the thread is next
6587 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6591 case BPSTAT_WHAT_HP_STEP_RESUME
:
6593 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6595 delete_step_resume_breakpoint (ecs
->event_thread
);
6596 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6598 /* Back when the step-resume breakpoint was inserted, we
6599 were trying to single-step off a breakpoint. Go back to
6601 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6602 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6608 case BPSTAT_WHAT_KEEP_CHECKING
:
6612 /* If we stepped a permanent breakpoint and we had a high priority
6613 step-resume breakpoint for the address we stepped, but we didn't
6614 hit it, then we must have stepped into the signal handler. The
6615 step-resume was only necessary to catch the case of _not_
6616 stepping into the handler, so delete it, and fall through to
6617 checking whether the step finished. */
6618 if (ecs
->event_thread
->stepped_breakpoint
)
6620 struct breakpoint
*sr_bp
6621 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6624 && sr_bp
->loc
->permanent
6625 && sr_bp
->type
== bp_hp_step_resume
6626 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6629 fprintf_unfiltered (gdb_stdlog
,
6630 "infrun: stepped permanent breakpoint, stopped in "
6632 delete_step_resume_breakpoint (ecs
->event_thread
);
6633 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6637 /* We come here if we hit a breakpoint but should not stop for it.
6638 Possibly we also were stepping and should stop for that. So fall
6639 through and test for stepping. But, if not stepping, do not
6642 /* In all-stop mode, if we're currently stepping but have stopped in
6643 some other thread, we need to switch back to the stepped thread. */
6644 if (switch_back_to_stepped_thread (ecs
))
6647 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6650 fprintf_unfiltered (gdb_stdlog
,
6651 "infrun: step-resume breakpoint is inserted\n");
6653 /* Having a step-resume breakpoint overrides anything
6654 else having to do with stepping commands until
6655 that breakpoint is reached. */
6660 if (ecs
->event_thread
->control
.step_range_end
== 0)
6663 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6664 /* Likewise if we aren't even stepping. */
6669 /* Re-fetch current thread's frame in case the code above caused
6670 the frame cache to be re-initialized, making our FRAME variable
6671 a dangling pointer. */
6672 frame
= get_current_frame ();
6673 gdbarch
= get_frame_arch (frame
);
6674 fill_in_stop_func (gdbarch
, ecs
);
6676 /* If stepping through a line, keep going if still within it.
6678 Note that step_range_end is the address of the first instruction
6679 beyond the step range, and NOT the address of the last instruction
6682 Note also that during reverse execution, we may be stepping
6683 through a function epilogue and therefore must detect when
6684 the current-frame changes in the middle of a line. */
6686 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6688 && (execution_direction
!= EXEC_REVERSE
6689 || frame_id_eq (get_frame_id (frame
),
6690 ecs
->event_thread
->control
.step_frame_id
)))
6694 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6695 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6696 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6698 /* Tentatively re-enable range stepping; `resume' disables it if
6699 necessary (e.g., if we're stepping over a breakpoint or we
6700 have software watchpoints). */
6701 ecs
->event_thread
->control
.may_range_step
= 1;
6703 /* When stepping backward, stop at beginning of line range
6704 (unless it's the function entry point, in which case
6705 keep going back to the call point). */
6706 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6707 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6708 && stop_pc
!= ecs
->stop_func_start
6709 && execution_direction
== EXEC_REVERSE
)
6710 end_stepping_range (ecs
);
6717 /* We stepped out of the stepping range. */
6719 /* If we are stepping at the source level and entered the runtime
6720 loader dynamic symbol resolution code...
6722 EXEC_FORWARD: we keep on single stepping until we exit the run
6723 time loader code and reach the callee's address.
6725 EXEC_REVERSE: we've already executed the callee (backward), and
6726 the runtime loader code is handled just like any other
6727 undebuggable function call. Now we need only keep stepping
6728 backward through the trampoline code, and that's handled further
6729 down, so there is nothing for us to do here. */
6731 if (execution_direction
!= EXEC_REVERSE
6732 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6733 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6735 CORE_ADDR pc_after_resolver
=
6736 gdbarch_skip_solib_resolver (gdbarch
,
6737 ecs
->event_thread
->suspend
.stop_pc
);
6740 fprintf_unfiltered (gdb_stdlog
,
6741 "infrun: stepped into dynsym resolve code\n");
6743 if (pc_after_resolver
)
6745 /* Set up a step-resume breakpoint at the address
6746 indicated by SKIP_SOLIB_RESOLVER. */
6747 symtab_and_line sr_sal
;
6748 sr_sal
.pc
= pc_after_resolver
;
6749 sr_sal
.pspace
= get_frame_program_space (frame
);
6751 insert_step_resume_breakpoint_at_sal (gdbarch
,
6752 sr_sal
, null_frame_id
);
6759 /* Step through an indirect branch thunk. */
6760 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6761 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6762 ecs
->event_thread
->suspend
.stop_pc
))
6765 fprintf_unfiltered (gdb_stdlog
,
6766 "infrun: stepped into indirect branch thunk\n");
6771 if (ecs
->event_thread
->control
.step_range_end
!= 1
6772 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6773 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6774 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6777 fprintf_unfiltered (gdb_stdlog
,
6778 "infrun: stepped into signal trampoline\n");
6779 /* The inferior, while doing a "step" or "next", has ended up in
6780 a signal trampoline (either by a signal being delivered or by
6781 the signal handler returning). Just single-step until the
6782 inferior leaves the trampoline (either by calling the handler
6788 /* If we're in the return path from a shared library trampoline,
6789 we want to proceed through the trampoline when stepping. */
6790 /* macro/2012-04-25: This needs to come before the subroutine
6791 call check below as on some targets return trampolines look
6792 like subroutine calls (MIPS16 return thunks). */
6793 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6794 ecs
->event_thread
->suspend
.stop_pc
,
6795 ecs
->stop_func_name
)
6796 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6798 /* Determine where this trampoline returns. */
6799 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6800 CORE_ADDR real_stop_pc
6801 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6804 fprintf_unfiltered (gdb_stdlog
,
6805 "infrun: stepped into solib return tramp\n");
6807 /* Only proceed through if we know where it's going. */
6810 /* And put the step-breakpoint there and go until there. */
6811 symtab_and_line sr_sal
;
6812 sr_sal
.pc
= real_stop_pc
;
6813 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6814 sr_sal
.pspace
= get_frame_program_space (frame
);
6816 /* Do not specify what the fp should be when we stop since
6817 on some machines the prologue is where the new fp value
6819 insert_step_resume_breakpoint_at_sal (gdbarch
,
6820 sr_sal
, null_frame_id
);
6822 /* Restart without fiddling with the step ranges or
6829 /* Check for subroutine calls. The check for the current frame
6830 equalling the step ID is not necessary - the check of the
6831 previous frame's ID is sufficient - but it is a common case and
6832 cheaper than checking the previous frame's ID.
6834 NOTE: frame_id_eq will never report two invalid frame IDs as
6835 being equal, so to get into this block, both the current and
6836 previous frame must have valid frame IDs. */
6837 /* The outer_frame_id check is a heuristic to detect stepping
6838 through startup code. If we step over an instruction which
6839 sets the stack pointer from an invalid value to a valid value,
6840 we may detect that as a subroutine call from the mythical
6841 "outermost" function. This could be fixed by marking
6842 outermost frames as !stack_p,code_p,special_p. Then the
6843 initial outermost frame, before sp was valid, would
6844 have code_addr == &_start. See the comment in frame_id_eq
6846 if (!frame_id_eq (get_stack_frame_id (frame
),
6847 ecs
->event_thread
->control
.step_stack_frame_id
)
6848 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6849 ecs
->event_thread
->control
.step_stack_frame_id
)
6850 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6852 || (ecs
->event_thread
->control
.step_start_function
6853 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6855 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6856 CORE_ADDR real_stop_pc
;
6859 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6861 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6863 /* I presume that step_over_calls is only 0 when we're
6864 supposed to be stepping at the assembly language level
6865 ("stepi"). Just stop. */
6866 /* And this works the same backward as frontward. MVS */
6867 end_stepping_range (ecs
);
6871 /* Reverse stepping through solib trampolines. */
6873 if (execution_direction
== EXEC_REVERSE
6874 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6875 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6876 || (ecs
->stop_func_start
== 0
6877 && in_solib_dynsym_resolve_code (stop_pc
))))
6879 /* Any solib trampoline code can be handled in reverse
6880 by simply continuing to single-step. We have already
6881 executed the solib function (backwards), and a few
6882 steps will take us back through the trampoline to the
6888 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6890 /* We're doing a "next".
6892 Normal (forward) execution: set a breakpoint at the
6893 callee's return address (the address at which the caller
6896 Reverse (backward) execution. set the step-resume
6897 breakpoint at the start of the function that we just
6898 stepped into (backwards), and continue to there. When we
6899 get there, we'll need to single-step back to the caller. */
6901 if (execution_direction
== EXEC_REVERSE
)
6903 /* If we're already at the start of the function, we've either
6904 just stepped backward into a single instruction function,
6905 or stepped back out of a signal handler to the first instruction
6906 of the function. Just keep going, which will single-step back
6908 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6910 /* Normal function call return (static or dynamic). */
6911 symtab_and_line sr_sal
;
6912 sr_sal
.pc
= ecs
->stop_func_start
;
6913 sr_sal
.pspace
= get_frame_program_space (frame
);
6914 insert_step_resume_breakpoint_at_sal (gdbarch
,
6915 sr_sal
, null_frame_id
);
6919 insert_step_resume_breakpoint_at_caller (frame
);
6925 /* If we are in a function call trampoline (a stub between the
6926 calling routine and the real function), locate the real
6927 function. That's what tells us (a) whether we want to step
6928 into it at all, and (b) what prologue we want to run to the
6929 end of, if we do step into it. */
6930 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6931 if (real_stop_pc
== 0)
6932 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6933 if (real_stop_pc
!= 0)
6934 ecs
->stop_func_start
= real_stop_pc
;
6936 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6938 symtab_and_line sr_sal
;
6939 sr_sal
.pc
= ecs
->stop_func_start
;
6940 sr_sal
.pspace
= get_frame_program_space (frame
);
6942 insert_step_resume_breakpoint_at_sal (gdbarch
,
6943 sr_sal
, null_frame_id
);
6948 /* If we have line number information for the function we are
6949 thinking of stepping into and the function isn't on the skip
6952 If there are several symtabs at that PC (e.g. with include
6953 files), just want to know whether *any* of them have line
6954 numbers. find_pc_line handles this. */
6956 struct symtab_and_line tmp_sal
;
6958 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6959 if (tmp_sal
.line
!= 0
6960 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6962 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6964 if (execution_direction
== EXEC_REVERSE
)
6965 handle_step_into_function_backward (gdbarch
, ecs
);
6967 handle_step_into_function (gdbarch
, ecs
);
6972 /* If we have no line number and the step-stop-if-no-debug is
6973 set, we stop the step so that the user has a chance to switch
6974 in assembly mode. */
6975 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6976 && step_stop_if_no_debug
)
6978 end_stepping_range (ecs
);
6982 if (execution_direction
== EXEC_REVERSE
)
6984 /* If we're already at the start of the function, we've either just
6985 stepped backward into a single instruction function without line
6986 number info, or stepped back out of a signal handler to the first
6987 instruction of the function without line number info. Just keep
6988 going, which will single-step back to the caller. */
6989 if (ecs
->stop_func_start
!= stop_pc
)
6991 /* Set a breakpoint at callee's start address.
6992 From there we can step once and be back in the caller. */
6993 symtab_and_line sr_sal
;
6994 sr_sal
.pc
= ecs
->stop_func_start
;
6995 sr_sal
.pspace
= get_frame_program_space (frame
);
6996 insert_step_resume_breakpoint_at_sal (gdbarch
,
6997 sr_sal
, null_frame_id
);
7001 /* Set a breakpoint at callee's return address (the address
7002 at which the caller will resume). */
7003 insert_step_resume_breakpoint_at_caller (frame
);
7009 /* Reverse stepping through solib trampolines. */
7011 if (execution_direction
== EXEC_REVERSE
7012 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7014 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7016 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7017 || (ecs
->stop_func_start
== 0
7018 && in_solib_dynsym_resolve_code (stop_pc
)))
7020 /* Any solib trampoline code can be handled in reverse
7021 by simply continuing to single-step. We have already
7022 executed the solib function (backwards), and a few
7023 steps will take us back through the trampoline to the
7028 else if (in_solib_dynsym_resolve_code (stop_pc
))
7030 /* Stepped backward into the solib dynsym resolver.
7031 Set a breakpoint at its start and continue, then
7032 one more step will take us out. */
7033 symtab_and_line sr_sal
;
7034 sr_sal
.pc
= ecs
->stop_func_start
;
7035 sr_sal
.pspace
= get_frame_program_space (frame
);
7036 insert_step_resume_breakpoint_at_sal (gdbarch
,
7037 sr_sal
, null_frame_id
);
7043 /* This always returns the sal for the inner-most frame when we are in a
7044 stack of inlined frames, even if GDB actually believes that it is in a
7045 more outer frame. This is checked for below by calls to
7046 inline_skipped_frames. */
7047 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7049 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7050 the trampoline processing logic, however, there are some trampolines
7051 that have no names, so we should do trampoline handling first. */
7052 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7053 && ecs
->stop_func_name
== NULL
7054 && stop_pc_sal
.line
== 0)
7057 fprintf_unfiltered (gdb_stdlog
,
7058 "infrun: stepped into undebuggable function\n");
7060 /* The inferior just stepped into, or returned to, an
7061 undebuggable function (where there is no debugging information
7062 and no line number corresponding to the address where the
7063 inferior stopped). Since we want to skip this kind of code,
7064 we keep going until the inferior returns from this
7065 function - unless the user has asked us not to (via
7066 set step-mode) or we no longer know how to get back
7067 to the call site. */
7068 if (step_stop_if_no_debug
7069 || !frame_id_p (frame_unwind_caller_id (frame
)))
7071 /* If we have no line number and the step-stop-if-no-debug
7072 is set, we stop the step so that the user has a chance to
7073 switch in assembly mode. */
7074 end_stepping_range (ecs
);
7079 /* Set a breakpoint at callee's return address (the address
7080 at which the caller will resume). */
7081 insert_step_resume_breakpoint_at_caller (frame
);
7087 if (ecs
->event_thread
->control
.step_range_end
== 1)
7089 /* It is stepi or nexti. We always want to stop stepping after
7092 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7093 end_stepping_range (ecs
);
7097 if (stop_pc_sal
.line
== 0)
7099 /* We have no line number information. That means to stop
7100 stepping (does this always happen right after one instruction,
7101 when we do "s" in a function with no line numbers,
7102 or can this happen as a result of a return or longjmp?). */
7104 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7105 end_stepping_range (ecs
);
7109 /* Look for "calls" to inlined functions, part one. If the inline
7110 frame machinery detected some skipped call sites, we have entered
7111 a new inline function. */
7113 if (frame_id_eq (get_frame_id (get_current_frame ()),
7114 ecs
->event_thread
->control
.step_frame_id
)
7115 && inline_skipped_frames (ecs
->event_thread
))
7118 fprintf_unfiltered (gdb_stdlog
,
7119 "infrun: stepped into inlined function\n");
7121 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7123 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7125 /* For "step", we're going to stop. But if the call site
7126 for this inlined function is on the same source line as
7127 we were previously stepping, go down into the function
7128 first. Otherwise stop at the call site. */
7130 if (call_sal
.line
== ecs
->event_thread
->current_line
7131 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7133 step_into_inline_frame (ecs
->event_thread
);
7134 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7141 end_stepping_range (ecs
);
7146 /* For "next", we should stop at the call site if it is on a
7147 different source line. Otherwise continue through the
7148 inlined function. */
7149 if (call_sal
.line
== ecs
->event_thread
->current_line
7150 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7153 end_stepping_range (ecs
);
7158 /* Look for "calls" to inlined functions, part two. If we are still
7159 in the same real function we were stepping through, but we have
7160 to go further up to find the exact frame ID, we are stepping
7161 through a more inlined call beyond its call site. */
7163 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7164 && !frame_id_eq (get_frame_id (get_current_frame ()),
7165 ecs
->event_thread
->control
.step_frame_id
)
7166 && stepped_in_from (get_current_frame (),
7167 ecs
->event_thread
->control
.step_frame_id
))
7170 fprintf_unfiltered (gdb_stdlog
,
7171 "infrun: stepping through inlined function\n");
7173 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7174 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7177 end_stepping_range (ecs
);
7181 bool refresh_step_info
= true;
7182 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7183 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7184 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7186 if (stop_pc_sal
.is_stmt
)
7188 /* We are at the start of a different line. So stop. Note that
7189 we don't stop if we step into the middle of a different line.
7190 That is said to make things like for (;;) statements work
7193 fprintf_unfiltered (gdb_stdlog
,
7194 "infrun: stepped to a different line\n");
7195 end_stepping_range (ecs
);
7198 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7199 ecs
->event_thread
->control
.step_frame_id
))
7201 /* We are at the start of a different line, however, this line is
7202 not marked as a statement, and we have not changed frame. We
7203 ignore this line table entry, and continue stepping forward,
7204 looking for a better place to stop. */
7205 refresh_step_info
= false;
7207 fprintf_unfiltered (gdb_stdlog
,
7208 "infrun: stepped to a different line, but "
7209 "it's not the start of a statement\n");
7213 /* We aren't done stepping.
7215 Optimize by setting the stepping range to the line.
7216 (We might not be in the original line, but if we entered a
7217 new line in mid-statement, we continue stepping. This makes
7218 things like for(;;) statements work better.)
7220 If we entered a SAL that indicates a non-statement line table entry,
7221 then we update the stepping range, but we don't update the step info,
7222 which includes things like the line number we are stepping away from.
7223 This means we will stop when we find a line table entry that is marked
7224 as is-statement, even if it matches the non-statement one we just
7227 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7228 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7229 ecs
->event_thread
->control
.may_range_step
= 1;
7230 if (refresh_step_info
)
7231 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7234 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7238 /* In all-stop mode, if we're currently stepping but have stopped in
7239 some other thread, we may need to switch back to the stepped
7240 thread. Returns true we set the inferior running, false if we left
7241 it stopped (and the event needs further processing). */
7244 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7246 if (!target_is_non_stop_p ())
7248 struct thread_info
*stepping_thread
;
7250 /* If any thread is blocked on some internal breakpoint, and we
7251 simply need to step over that breakpoint to get it going
7252 again, do that first. */
7254 /* However, if we see an event for the stepping thread, then we
7255 know all other threads have been moved past their breakpoints
7256 already. Let the caller check whether the step is finished,
7257 etc., before deciding to move it past a breakpoint. */
7258 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7261 /* Check if the current thread is blocked on an incomplete
7262 step-over, interrupted by a random signal. */
7263 if (ecs
->event_thread
->control
.trap_expected
7264 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7268 fprintf_unfiltered (gdb_stdlog
,
7269 "infrun: need to finish step-over of [%s]\n",
7270 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7276 /* Check if the current thread is blocked by a single-step
7277 breakpoint of another thread. */
7278 if (ecs
->hit_singlestep_breakpoint
)
7282 fprintf_unfiltered (gdb_stdlog
,
7283 "infrun: need to step [%s] over single-step "
7285 target_pid_to_str (ecs
->ptid
).c_str ());
7291 /* If this thread needs yet another step-over (e.g., stepping
7292 through a delay slot), do it first before moving on to
7294 if (thread_still_needs_step_over (ecs
->event_thread
))
7298 fprintf_unfiltered (gdb_stdlog
,
7299 "infrun: thread [%s] still needs step-over\n",
7300 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7306 /* If scheduler locking applies even if not stepping, there's no
7307 need to walk over threads. Above we've checked whether the
7308 current thread is stepping. If some other thread not the
7309 event thread is stepping, then it must be that scheduler
7310 locking is not in effect. */
7311 if (schedlock_applies (ecs
->event_thread
))
7314 /* Otherwise, we no longer expect a trap in the current thread.
7315 Clear the trap_expected flag before switching back -- this is
7316 what keep_going does as well, if we call it. */
7317 ecs
->event_thread
->control
.trap_expected
= 0;
7319 /* Likewise, clear the signal if it should not be passed. */
7320 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7321 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7323 /* Do all pending step-overs before actually proceeding with
7325 if (start_step_over ())
7327 prepare_to_wait (ecs
);
7331 /* Look for the stepping/nexting thread. */
7332 stepping_thread
= NULL
;
7334 for (thread_info
*tp
: all_non_exited_threads ())
7336 switch_to_thread_no_regs (tp
);
7338 /* Ignore threads of processes the caller is not
7341 && (tp
->inf
->process_target () != ecs
->target
7342 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7345 /* When stepping over a breakpoint, we lock all threads
7346 except the one that needs to move past the breakpoint.
7347 If a non-event thread has this set, the "incomplete
7348 step-over" check above should have caught it earlier. */
7349 if (tp
->control
.trap_expected
)
7351 internal_error (__FILE__
, __LINE__
,
7352 "[%s] has inconsistent state: "
7353 "trap_expected=%d\n",
7354 target_pid_to_str (tp
->ptid
).c_str (),
7355 tp
->control
.trap_expected
);
7358 /* Did we find the stepping thread? */
7359 if (tp
->control
.step_range_end
)
7361 /* Yep. There should only one though. */
7362 gdb_assert (stepping_thread
== NULL
);
7364 /* The event thread is handled at the top, before we
7366 gdb_assert (tp
!= ecs
->event_thread
);
7368 /* If some thread other than the event thread is
7369 stepping, then scheduler locking can't be in effect,
7370 otherwise we wouldn't have resumed the current event
7371 thread in the first place. */
7372 gdb_assert (!schedlock_applies (tp
));
7374 stepping_thread
= tp
;
7378 if (stepping_thread
!= NULL
)
7381 fprintf_unfiltered (gdb_stdlog
,
7382 "infrun: switching back to stepped thread\n");
7384 if (keep_going_stepped_thread (stepping_thread
))
7386 prepare_to_wait (ecs
);
7391 switch_to_thread (ecs
->event_thread
);
7397 /* Set a previously stepped thread back to stepping. Returns true on
7398 success, false if the resume is not possible (e.g., the thread
7402 keep_going_stepped_thread (struct thread_info
*tp
)
7404 struct frame_info
*frame
;
7405 struct execution_control_state ecss
;
7406 struct execution_control_state
*ecs
= &ecss
;
7408 /* If the stepping thread exited, then don't try to switch back and
7409 resume it, which could fail in several different ways depending
7410 on the target. Instead, just keep going.
7412 We can find a stepping dead thread in the thread list in two
7415 - The target supports thread exit events, and when the target
7416 tries to delete the thread from the thread list, inferior_ptid
7417 pointed at the exiting thread. In such case, calling
7418 delete_thread does not really remove the thread from the list;
7419 instead, the thread is left listed, with 'exited' state.
7421 - The target's debug interface does not support thread exit
7422 events, and so we have no idea whatsoever if the previously
7423 stepping thread is still alive. For that reason, we need to
7424 synchronously query the target now. */
7426 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7429 fprintf_unfiltered (gdb_stdlog
,
7430 "infrun: not resuming previously "
7431 "stepped thread, it has vanished\n");
7438 fprintf_unfiltered (gdb_stdlog
,
7439 "infrun: resuming previously stepped thread\n");
7441 reset_ecs (ecs
, tp
);
7442 switch_to_thread (tp
);
7444 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7445 frame
= get_current_frame ();
7447 /* If the PC of the thread we were trying to single-step has
7448 changed, then that thread has trapped or been signaled, but the
7449 event has not been reported to GDB yet. Re-poll the target
7450 looking for this particular thread's event (i.e. temporarily
7451 enable schedlock) by:
7453 - setting a break at the current PC
7454 - resuming that particular thread, only (by setting trap
7457 This prevents us continuously moving the single-step breakpoint
7458 forward, one instruction at a time, overstepping. */
7460 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7465 fprintf_unfiltered (gdb_stdlog
,
7466 "infrun: expected thread advanced also (%s -> %s)\n",
7467 paddress (target_gdbarch (), tp
->prev_pc
),
7468 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7470 /* Clear the info of the previous step-over, as it's no longer
7471 valid (if the thread was trying to step over a breakpoint, it
7472 has already succeeded). It's what keep_going would do too,
7473 if we called it. Do this before trying to insert the sss
7474 breakpoint, otherwise if we were previously trying to step
7475 over this exact address in another thread, the breakpoint is
7477 clear_step_over_info ();
7478 tp
->control
.trap_expected
= 0;
7480 insert_single_step_breakpoint (get_frame_arch (frame
),
7481 get_frame_address_space (frame
),
7482 tp
->suspend
.stop_pc
);
7485 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7486 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7491 fprintf_unfiltered (gdb_stdlog
,
7492 "infrun: expected thread still hasn't advanced\n");
7494 keep_going_pass_signal (ecs
);
7499 /* Is thread TP in the middle of (software or hardware)
7500 single-stepping? (Note the result of this function must never be
7501 passed directly as target_resume's STEP parameter.) */
7504 currently_stepping (struct thread_info
*tp
)
7506 return ((tp
->control
.step_range_end
7507 && tp
->control
.step_resume_breakpoint
== NULL
)
7508 || tp
->control
.trap_expected
7509 || tp
->stepped_breakpoint
7510 || bpstat_should_step ());
7513 /* Inferior has stepped into a subroutine call with source code that
7514 we should not step over. Do step to the first line of code in
7518 handle_step_into_function (struct gdbarch
*gdbarch
,
7519 struct execution_control_state
*ecs
)
7521 fill_in_stop_func (gdbarch
, ecs
);
7523 compunit_symtab
*cust
7524 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7525 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7526 ecs
->stop_func_start
7527 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7529 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7530 /* Use the step_resume_break to step until the end of the prologue,
7531 even if that involves jumps (as it seems to on the vax under
7533 /* If the prologue ends in the middle of a source line, continue to
7534 the end of that source line (if it is still within the function).
7535 Otherwise, just go to end of prologue. */
7536 if (stop_func_sal
.end
7537 && stop_func_sal
.pc
!= ecs
->stop_func_start
7538 && stop_func_sal
.end
< ecs
->stop_func_end
)
7539 ecs
->stop_func_start
= stop_func_sal
.end
;
7541 /* Architectures which require breakpoint adjustment might not be able
7542 to place a breakpoint at the computed address. If so, the test
7543 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7544 ecs->stop_func_start to an address at which a breakpoint may be
7545 legitimately placed.
7547 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7548 made, GDB will enter an infinite loop when stepping through
7549 optimized code consisting of VLIW instructions which contain
7550 subinstructions corresponding to different source lines. On
7551 FR-V, it's not permitted to place a breakpoint on any but the
7552 first subinstruction of a VLIW instruction. When a breakpoint is
7553 set, GDB will adjust the breakpoint address to the beginning of
7554 the VLIW instruction. Thus, we need to make the corresponding
7555 adjustment here when computing the stop address. */
7557 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7559 ecs
->stop_func_start
7560 = gdbarch_adjust_breakpoint_address (gdbarch
,
7561 ecs
->stop_func_start
);
7564 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7566 /* We are already there: stop now. */
7567 end_stepping_range (ecs
);
7572 /* Put the step-breakpoint there and go until there. */
7573 symtab_and_line sr_sal
;
7574 sr_sal
.pc
= ecs
->stop_func_start
;
7575 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7576 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7578 /* Do not specify what the fp should be when we stop since on
7579 some machines the prologue is where the new fp value is
7581 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7583 /* And make sure stepping stops right away then. */
7584 ecs
->event_thread
->control
.step_range_end
7585 = ecs
->event_thread
->control
.step_range_start
;
7590 /* Inferior has stepped backward into a subroutine call with source
7591 code that we should not step over. Do step to the beginning of the
7592 last line of code in it. */
7595 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7596 struct execution_control_state
*ecs
)
7598 struct compunit_symtab
*cust
;
7599 struct symtab_and_line stop_func_sal
;
7601 fill_in_stop_func (gdbarch
, ecs
);
7603 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7604 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7605 ecs
->stop_func_start
7606 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7608 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7610 /* OK, we're just going to keep stepping here. */
7611 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7613 /* We're there already. Just stop stepping now. */
7614 end_stepping_range (ecs
);
7618 /* Else just reset the step range and keep going.
7619 No step-resume breakpoint, they don't work for
7620 epilogues, which can have multiple entry paths. */
7621 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7622 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7628 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7629 This is used to both functions and to skip over code. */
7632 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7633 struct symtab_and_line sr_sal
,
7634 struct frame_id sr_id
,
7635 enum bptype sr_type
)
7637 /* There should never be more than one step-resume or longjmp-resume
7638 breakpoint per thread, so we should never be setting a new
7639 step_resume_breakpoint when one is already active. */
7640 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7641 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7644 fprintf_unfiltered (gdb_stdlog
,
7645 "infrun: inserting step-resume breakpoint at %s\n",
7646 paddress (gdbarch
, sr_sal
.pc
));
7648 inferior_thread ()->control
.step_resume_breakpoint
7649 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7653 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7654 struct symtab_and_line sr_sal
,
7655 struct frame_id sr_id
)
7657 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7662 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7663 This is used to skip a potential signal handler.
7665 This is called with the interrupted function's frame. The signal
7666 handler, when it returns, will resume the interrupted function at
7670 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7672 gdb_assert (return_frame
!= NULL
);
7674 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7676 symtab_and_line sr_sal
;
7677 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7678 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7679 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7681 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7682 get_stack_frame_id (return_frame
),
7686 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7687 is used to skip a function after stepping into it (for "next" or if
7688 the called function has no debugging information).
7690 The current function has almost always been reached by single
7691 stepping a call or return instruction. NEXT_FRAME belongs to the
7692 current function, and the breakpoint will be set at the caller's
7695 This is a separate function rather than reusing
7696 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7697 get_prev_frame, which may stop prematurely (see the implementation
7698 of frame_unwind_caller_id for an example). */
7701 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7703 /* We shouldn't have gotten here if we don't know where the call site
7705 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7707 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7709 symtab_and_line sr_sal
;
7710 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7711 frame_unwind_caller_pc (next_frame
));
7712 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7713 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7715 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7716 frame_unwind_caller_id (next_frame
));
7719 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7720 new breakpoint at the target of a jmp_buf. The handling of
7721 longjmp-resume uses the same mechanisms used for handling
7722 "step-resume" breakpoints. */
7725 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7727 /* There should never be more than one longjmp-resume breakpoint per
7728 thread, so we should never be setting a new
7729 longjmp_resume_breakpoint when one is already active. */
7730 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7733 fprintf_unfiltered (gdb_stdlog
,
7734 "infrun: inserting longjmp-resume breakpoint at %s\n",
7735 paddress (gdbarch
, pc
));
7737 inferior_thread ()->control
.exception_resume_breakpoint
=
7738 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7741 /* Insert an exception resume breakpoint. TP is the thread throwing
7742 the exception. The block B is the block of the unwinder debug hook
7743 function. FRAME is the frame corresponding to the call to this
7744 function. SYM is the symbol of the function argument holding the
7745 target PC of the exception. */
7748 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7749 const struct block
*b
,
7750 struct frame_info
*frame
,
7755 struct block_symbol vsym
;
7756 struct value
*value
;
7758 struct breakpoint
*bp
;
7760 vsym
= lookup_symbol_search_name (sym
->search_name (),
7762 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7763 /* If the value was optimized out, revert to the old behavior. */
7764 if (! value_optimized_out (value
))
7766 handler
= value_as_address (value
);
7769 fprintf_unfiltered (gdb_stdlog
,
7770 "infrun: exception resume at %lx\n",
7771 (unsigned long) handler
);
7773 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7775 bp_exception_resume
).release ();
7777 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7780 bp
->thread
= tp
->global_num
;
7781 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7784 catch (const gdb_exception_error
&e
)
7786 /* We want to ignore errors here. */
7790 /* A helper for check_exception_resume that sets an
7791 exception-breakpoint based on a SystemTap probe. */
7794 insert_exception_resume_from_probe (struct thread_info
*tp
,
7795 const struct bound_probe
*probe
,
7796 struct frame_info
*frame
)
7798 struct value
*arg_value
;
7800 struct breakpoint
*bp
;
7802 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7806 handler
= value_as_address (arg_value
);
7809 fprintf_unfiltered (gdb_stdlog
,
7810 "infrun: exception resume at %s\n",
7811 paddress (get_objfile_arch (probe
->objfile
),
7814 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7815 handler
, bp_exception_resume
).release ();
7816 bp
->thread
= tp
->global_num
;
7817 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7820 /* This is called when an exception has been intercepted. Check to
7821 see whether the exception's destination is of interest, and if so,
7822 set an exception resume breakpoint there. */
7825 check_exception_resume (struct execution_control_state
*ecs
,
7826 struct frame_info
*frame
)
7828 struct bound_probe probe
;
7829 struct symbol
*func
;
7831 /* First see if this exception unwinding breakpoint was set via a
7832 SystemTap probe point. If so, the probe has two arguments: the
7833 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7834 set a breakpoint there. */
7835 probe
= find_probe_by_pc (get_frame_pc (frame
));
7838 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7842 func
= get_frame_function (frame
);
7848 const struct block
*b
;
7849 struct block_iterator iter
;
7853 /* The exception breakpoint is a thread-specific breakpoint on
7854 the unwinder's debug hook, declared as:
7856 void _Unwind_DebugHook (void *cfa, void *handler);
7858 The CFA argument indicates the frame to which control is
7859 about to be transferred. HANDLER is the destination PC.
7861 We ignore the CFA and set a temporary breakpoint at HANDLER.
7862 This is not extremely efficient but it avoids issues in gdb
7863 with computing the DWARF CFA, and it also works even in weird
7864 cases such as throwing an exception from inside a signal
7867 b
= SYMBOL_BLOCK_VALUE (func
);
7868 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7870 if (!SYMBOL_IS_ARGUMENT (sym
))
7877 insert_exception_resume_breakpoint (ecs
->event_thread
,
7883 catch (const gdb_exception_error
&e
)
7889 stop_waiting (struct execution_control_state
*ecs
)
7892 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7894 /* Let callers know we don't want to wait for the inferior anymore. */
7895 ecs
->wait_some_more
= 0;
7897 /* If all-stop, but the target is always in non-stop mode, stop all
7898 threads now that we're presenting the stop to the user. */
7899 if (!non_stop
&& target_is_non_stop_p ())
7900 stop_all_threads ();
7903 /* Like keep_going, but passes the signal to the inferior, even if the
7904 signal is set to nopass. */
7907 keep_going_pass_signal (struct execution_control_state
*ecs
)
7909 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7910 gdb_assert (!ecs
->event_thread
->resumed
);
7912 /* Save the pc before execution, to compare with pc after stop. */
7913 ecs
->event_thread
->prev_pc
7914 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7916 if (ecs
->event_thread
->control
.trap_expected
)
7918 struct thread_info
*tp
= ecs
->event_thread
;
7921 fprintf_unfiltered (gdb_stdlog
,
7922 "infrun: %s has trap_expected set, "
7923 "resuming to collect trap\n",
7924 target_pid_to_str (tp
->ptid
).c_str ());
7926 /* We haven't yet gotten our trap, and either: intercepted a
7927 non-signal event (e.g., a fork); or took a signal which we
7928 are supposed to pass through to the inferior. Simply
7930 resume (ecs
->event_thread
->suspend
.stop_signal
);
7932 else if (step_over_info_valid_p ())
7934 /* Another thread is stepping over a breakpoint in-line. If
7935 this thread needs a step-over too, queue the request. In
7936 either case, this resume must be deferred for later. */
7937 struct thread_info
*tp
= ecs
->event_thread
;
7939 if (ecs
->hit_singlestep_breakpoint
7940 || thread_still_needs_step_over (tp
))
7943 fprintf_unfiltered (gdb_stdlog
,
7944 "infrun: step-over already in progress: "
7945 "step-over for %s deferred\n",
7946 target_pid_to_str (tp
->ptid
).c_str ());
7947 thread_step_over_chain_enqueue (tp
);
7952 fprintf_unfiltered (gdb_stdlog
,
7953 "infrun: step-over in progress: "
7954 "resume of %s deferred\n",
7955 target_pid_to_str (tp
->ptid
).c_str ());
7960 struct regcache
*regcache
= get_current_regcache ();
7963 step_over_what step_what
;
7965 /* Either the trap was not expected, but we are continuing
7966 anyway (if we got a signal, the user asked it be passed to
7969 We got our expected trap, but decided we should resume from
7972 We're going to run this baby now!
7974 Note that insert_breakpoints won't try to re-insert
7975 already inserted breakpoints. Therefore, we don't
7976 care if breakpoints were already inserted, or not. */
7978 /* If we need to step over a breakpoint, and we're not using
7979 displaced stepping to do so, insert all breakpoints
7980 (watchpoints, etc.) but the one we're stepping over, step one
7981 instruction, and then re-insert the breakpoint when that step
7984 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7986 remove_bp
= (ecs
->hit_singlestep_breakpoint
7987 || (step_what
& STEP_OVER_BREAKPOINT
));
7988 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7990 /* We can't use displaced stepping if we need to step past a
7991 watchpoint. The instruction copied to the scratch pad would
7992 still trigger the watchpoint. */
7994 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7996 set_step_over_info (regcache
->aspace (),
7997 regcache_read_pc (regcache
), remove_wps
,
7998 ecs
->event_thread
->global_num
);
8000 else if (remove_wps
)
8001 set_step_over_info (NULL
, 0, remove_wps
, -1);
8003 /* If we now need to do an in-line step-over, we need to stop
8004 all other threads. Note this must be done before
8005 insert_breakpoints below, because that removes the breakpoint
8006 we're about to step over, otherwise other threads could miss
8008 if (step_over_info_valid_p () && target_is_non_stop_p ())
8009 stop_all_threads ();
8011 /* Stop stepping if inserting breakpoints fails. */
8014 insert_breakpoints ();
8016 catch (const gdb_exception_error
&e
)
8018 exception_print (gdb_stderr
, e
);
8020 clear_step_over_info ();
8024 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8026 resume (ecs
->event_thread
->suspend
.stop_signal
);
8029 prepare_to_wait (ecs
);
8032 /* Called when we should continue running the inferior, because the
8033 current event doesn't cause a user visible stop. This does the
8034 resuming part; waiting for the next event is done elsewhere. */
8037 keep_going (struct execution_control_state
*ecs
)
8039 if (ecs
->event_thread
->control
.trap_expected
8040 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8041 ecs
->event_thread
->control
.trap_expected
= 0;
8043 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8044 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8045 keep_going_pass_signal (ecs
);
8048 /* This function normally comes after a resume, before
8049 handle_inferior_event exits. It takes care of any last bits of
8050 housekeeping, and sets the all-important wait_some_more flag. */
8053 prepare_to_wait (struct execution_control_state
*ecs
)
8056 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
8058 ecs
->wait_some_more
= 1;
8060 if (!target_is_async_p ())
8061 mark_infrun_async_event_handler ();
8064 /* We are done with the step range of a step/next/si/ni command.
8065 Called once for each n of a "step n" operation. */
8068 end_stepping_range (struct execution_control_state
*ecs
)
8070 ecs
->event_thread
->control
.stop_step
= 1;
8074 /* Several print_*_reason functions to print why the inferior has stopped.
8075 We always print something when the inferior exits, or receives a signal.
8076 The rest of the cases are dealt with later on in normal_stop and
8077 print_it_typical. Ideally there should be a call to one of these
8078 print_*_reason functions functions from handle_inferior_event each time
8079 stop_waiting is called.
8081 Note that we don't call these directly, instead we delegate that to
8082 the interpreters, through observers. Interpreters then call these
8083 with whatever uiout is right. */
8086 print_end_stepping_range_reason (struct ui_out
*uiout
)
8088 /* For CLI-like interpreters, print nothing. */
8090 if (uiout
->is_mi_like_p ())
8092 uiout
->field_string ("reason",
8093 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8098 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8100 annotate_signalled ();
8101 if (uiout
->is_mi_like_p ())
8103 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8104 uiout
->text ("\nProgram terminated with signal ");
8105 annotate_signal_name ();
8106 uiout
->field_string ("signal-name",
8107 gdb_signal_to_name (siggnal
));
8108 annotate_signal_name_end ();
8110 annotate_signal_string ();
8111 uiout
->field_string ("signal-meaning",
8112 gdb_signal_to_string (siggnal
));
8113 annotate_signal_string_end ();
8114 uiout
->text (".\n");
8115 uiout
->text ("The program no longer exists.\n");
8119 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8121 struct inferior
*inf
= current_inferior ();
8122 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8124 annotate_exited (exitstatus
);
8127 if (uiout
->is_mi_like_p ())
8128 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8129 std::string exit_code_str
8130 = string_printf ("0%o", (unsigned int) exitstatus
);
8131 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8132 plongest (inf
->num
), pidstr
.c_str (),
8133 string_field ("exit-code", exit_code_str
.c_str ()));
8137 if (uiout
->is_mi_like_p ())
8139 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8140 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8141 plongest (inf
->num
), pidstr
.c_str ());
8145 /* Some targets/architectures can do extra processing/display of
8146 segmentation faults. E.g., Intel MPX boundary faults.
8147 Call the architecture dependent function to handle the fault. */
8150 handle_segmentation_fault (struct ui_out
*uiout
)
8152 struct regcache
*regcache
= get_current_regcache ();
8153 struct gdbarch
*gdbarch
= regcache
->arch ();
8155 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8156 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8160 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8162 struct thread_info
*thr
= inferior_thread ();
8166 if (uiout
->is_mi_like_p ())
8168 else if (show_thread_that_caused_stop ())
8172 uiout
->text ("\nThread ");
8173 uiout
->field_string ("thread-id", print_thread_id (thr
));
8175 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8178 uiout
->text (" \"");
8179 uiout
->field_string ("name", name
);
8184 uiout
->text ("\nProgram");
8186 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8187 uiout
->text (" stopped");
8190 uiout
->text (" received signal ");
8191 annotate_signal_name ();
8192 if (uiout
->is_mi_like_p ())
8194 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8195 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8196 annotate_signal_name_end ();
8198 annotate_signal_string ();
8199 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8201 if (siggnal
== GDB_SIGNAL_SEGV
)
8202 handle_segmentation_fault (uiout
);
8204 annotate_signal_string_end ();
8206 uiout
->text (".\n");
8210 print_no_history_reason (struct ui_out
*uiout
)
8212 uiout
->text ("\nNo more reverse-execution history.\n");
8215 /* Print current location without a level number, if we have changed
8216 functions or hit a breakpoint. Print source line if we have one.
8217 bpstat_print contains the logic deciding in detail what to print,
8218 based on the event(s) that just occurred. */
8221 print_stop_location (struct target_waitstatus
*ws
)
8224 enum print_what source_flag
;
8225 int do_frame_printing
= 1;
8226 struct thread_info
*tp
= inferior_thread ();
8228 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8232 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8233 should) carry around the function and does (or should) use
8234 that when doing a frame comparison. */
8235 if (tp
->control
.stop_step
8236 && frame_id_eq (tp
->control
.step_frame_id
,
8237 get_frame_id (get_current_frame ()))
8238 && (tp
->control
.step_start_function
8239 == find_pc_function (tp
->suspend
.stop_pc
)))
8241 /* Finished step, just print source line. */
8242 source_flag
= SRC_LINE
;
8246 /* Print location and source line. */
8247 source_flag
= SRC_AND_LOC
;
8250 case PRINT_SRC_AND_LOC
:
8251 /* Print location and source line. */
8252 source_flag
= SRC_AND_LOC
;
8254 case PRINT_SRC_ONLY
:
8255 source_flag
= SRC_LINE
;
8258 /* Something bogus. */
8259 source_flag
= SRC_LINE
;
8260 do_frame_printing
= 0;
8263 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8266 /* The behavior of this routine with respect to the source
8268 SRC_LINE: Print only source line
8269 LOCATION: Print only location
8270 SRC_AND_LOC: Print location and source line. */
8271 if (do_frame_printing
)
8272 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8278 print_stop_event (struct ui_out
*uiout
, bool displays
)
8280 struct target_waitstatus last
;
8281 struct thread_info
*tp
;
8283 get_last_target_status (nullptr, nullptr, &last
);
8286 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8288 print_stop_location (&last
);
8290 /* Display the auto-display expressions. */
8295 tp
= inferior_thread ();
8296 if (tp
->thread_fsm
!= NULL
8297 && tp
->thread_fsm
->finished_p ())
8299 struct return_value_info
*rv
;
8301 rv
= tp
->thread_fsm
->return_value ();
8303 print_return_value (uiout
, rv
);
8310 maybe_remove_breakpoints (void)
8312 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8314 if (remove_breakpoints ())
8316 target_terminal::ours_for_output ();
8317 printf_filtered (_("Cannot remove breakpoints because "
8318 "program is no longer writable.\nFurther "
8319 "execution is probably impossible.\n"));
8324 /* The execution context that just caused a normal stop. */
8331 DISABLE_COPY_AND_ASSIGN (stop_context
);
8333 bool changed () const;
8338 /* The event PTID. */
8342 /* If stopp for a thread event, this is the thread that caused the
8344 struct thread_info
*thread
;
8346 /* The inferior that caused the stop. */
8350 /* Initializes a new stop context. If stopped for a thread event, this
8351 takes a strong reference to the thread. */
8353 stop_context::stop_context ()
8355 stop_id
= get_stop_id ();
8356 ptid
= inferior_ptid
;
8357 inf_num
= current_inferior ()->num
;
8359 if (inferior_ptid
!= null_ptid
)
8361 /* Take a strong reference so that the thread can't be deleted
8363 thread
= inferior_thread ();
8370 /* Release a stop context previously created with save_stop_context.
8371 Releases the strong reference to the thread as well. */
8373 stop_context::~stop_context ()
8379 /* Return true if the current context no longer matches the saved stop
8383 stop_context::changed () const
8385 if (ptid
!= inferior_ptid
)
8387 if (inf_num
!= current_inferior ()->num
)
8389 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8391 if (get_stop_id () != stop_id
)
8401 struct target_waitstatus last
;
8403 get_last_target_status (nullptr, nullptr, &last
);
8407 /* If an exception is thrown from this point on, make sure to
8408 propagate GDB's knowledge of the executing state to the
8409 frontend/user running state. A QUIT is an easy exception to see
8410 here, so do this before any filtered output. */
8412 ptid_t finish_ptid
= null_ptid
;
8415 finish_ptid
= minus_one_ptid
;
8416 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8417 || last
.kind
== TARGET_WAITKIND_EXITED
)
8419 /* On some targets, we may still have live threads in the
8420 inferior when we get a process exit event. E.g., for
8421 "checkpoint", when the current checkpoint/fork exits,
8422 linux-fork.c automatically switches to another fork from
8423 within target_mourn_inferior. */
8424 if (inferior_ptid
!= null_ptid
)
8425 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8427 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8428 finish_ptid
= inferior_ptid
;
8430 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8431 if (finish_ptid
!= null_ptid
)
8433 maybe_finish_thread_state
.emplace
8434 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8437 /* As we're presenting a stop, and potentially removing breakpoints,
8438 update the thread list so we can tell whether there are threads
8439 running on the target. With target remote, for example, we can
8440 only learn about new threads when we explicitly update the thread
8441 list. Do this before notifying the interpreters about signal
8442 stops, end of stepping ranges, etc., so that the "new thread"
8443 output is emitted before e.g., "Program received signal FOO",
8444 instead of after. */
8445 update_thread_list ();
8447 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8448 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8450 /* As with the notification of thread events, we want to delay
8451 notifying the user that we've switched thread context until
8452 the inferior actually stops.
8454 There's no point in saying anything if the inferior has exited.
8455 Note that SIGNALLED here means "exited with a signal", not
8456 "received a signal".
8458 Also skip saying anything in non-stop mode. In that mode, as we
8459 don't want GDB to switch threads behind the user's back, to avoid
8460 races where the user is typing a command to apply to thread x,
8461 but GDB switches to thread y before the user finishes entering
8462 the command, fetch_inferior_event installs a cleanup to restore
8463 the current thread back to the thread the user had selected right
8464 after this event is handled, so we're not really switching, only
8465 informing of a stop. */
8467 && previous_inferior_ptid
!= inferior_ptid
8468 && target_has_execution
8469 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8470 && last
.kind
!= TARGET_WAITKIND_EXITED
8471 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8473 SWITCH_THRU_ALL_UIS ()
8475 target_terminal::ours_for_output ();
8476 printf_filtered (_("[Switching to %s]\n"),
8477 target_pid_to_str (inferior_ptid
).c_str ());
8478 annotate_thread_changed ();
8480 previous_inferior_ptid
= inferior_ptid
;
8483 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8485 SWITCH_THRU_ALL_UIS ()
8486 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8488 target_terminal::ours_for_output ();
8489 printf_filtered (_("No unwaited-for children left.\n"));
8493 /* Note: this depends on the update_thread_list call above. */
8494 maybe_remove_breakpoints ();
8496 /* If an auto-display called a function and that got a signal,
8497 delete that auto-display to avoid an infinite recursion. */
8499 if (stopped_by_random_signal
)
8500 disable_current_display ();
8502 SWITCH_THRU_ALL_UIS ()
8504 async_enable_stdin ();
8507 /* Let the user/frontend see the threads as stopped. */
8508 maybe_finish_thread_state
.reset ();
8510 /* Select innermost stack frame - i.e., current frame is frame 0,
8511 and current location is based on that. Handle the case where the
8512 dummy call is returning after being stopped. E.g. the dummy call
8513 previously hit a breakpoint. (If the dummy call returns
8514 normally, we won't reach here.) Do this before the stop hook is
8515 run, so that it doesn't get to see the temporary dummy frame,
8516 which is not where we'll present the stop. */
8517 if (has_stack_frames ())
8519 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8521 /* Pop the empty frame that contains the stack dummy. This
8522 also restores inferior state prior to the call (struct
8523 infcall_suspend_state). */
8524 struct frame_info
*frame
= get_current_frame ();
8526 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8528 /* frame_pop calls reinit_frame_cache as the last thing it
8529 does which means there's now no selected frame. */
8532 select_frame (get_current_frame ());
8534 /* Set the current source location. */
8535 set_current_sal_from_frame (get_current_frame ());
8538 /* Look up the hook_stop and run it (CLI internally handles problem
8539 of stop_command's pre-hook not existing). */
8540 if (stop_command
!= NULL
)
8542 stop_context saved_context
;
8546 execute_cmd_pre_hook (stop_command
);
8548 catch (const gdb_exception
&ex
)
8550 exception_fprintf (gdb_stderr
, ex
,
8551 "Error while running hook_stop:\n");
8554 /* If the stop hook resumes the target, then there's no point in
8555 trying to notify about the previous stop; its context is
8556 gone. Likewise if the command switches thread or inferior --
8557 the observers would print a stop for the wrong
8559 if (saved_context
.changed ())
8563 /* Notify observers about the stop. This is where the interpreters
8564 print the stop event. */
8565 if (inferior_ptid
!= null_ptid
)
8566 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8569 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8571 annotate_stopped ();
8573 if (target_has_execution
)
8575 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8576 && last
.kind
!= TARGET_WAITKIND_EXITED
8577 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8578 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8579 Delete any breakpoint that is to be deleted at the next stop. */
8580 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8583 /* Try to get rid of automatically added inferiors that are no
8584 longer needed. Keeping those around slows down things linearly.
8585 Note that this never removes the current inferior. */
8592 signal_stop_state (int signo
)
8594 return signal_stop
[signo
];
8598 signal_print_state (int signo
)
8600 return signal_print
[signo
];
8604 signal_pass_state (int signo
)
8606 return signal_program
[signo
];
8610 signal_cache_update (int signo
)
8614 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8615 signal_cache_update (signo
);
8620 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8621 && signal_print
[signo
] == 0
8622 && signal_program
[signo
] == 1
8623 && signal_catch
[signo
] == 0);
8627 signal_stop_update (int signo
, int state
)
8629 int ret
= signal_stop
[signo
];
8631 signal_stop
[signo
] = state
;
8632 signal_cache_update (signo
);
8637 signal_print_update (int signo
, int state
)
8639 int ret
= signal_print
[signo
];
8641 signal_print
[signo
] = state
;
8642 signal_cache_update (signo
);
8647 signal_pass_update (int signo
, int state
)
8649 int ret
= signal_program
[signo
];
8651 signal_program
[signo
] = state
;
8652 signal_cache_update (signo
);
8656 /* Update the global 'signal_catch' from INFO and notify the
8660 signal_catch_update (const unsigned int *info
)
8664 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8665 signal_catch
[i
] = info
[i
] > 0;
8666 signal_cache_update (-1);
8667 target_pass_signals (signal_pass
);
8671 sig_print_header (void)
8673 printf_filtered (_("Signal Stop\tPrint\tPass "
8674 "to program\tDescription\n"));
8678 sig_print_info (enum gdb_signal oursig
)
8680 const char *name
= gdb_signal_to_name (oursig
);
8681 int name_padding
= 13 - strlen (name
);
8683 if (name_padding
<= 0)
8686 printf_filtered ("%s", name
);
8687 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8688 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8689 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8690 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8691 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8694 /* Specify how various signals in the inferior should be handled. */
8697 handle_command (const char *args
, int from_tty
)
8699 int digits
, wordlen
;
8700 int sigfirst
, siglast
;
8701 enum gdb_signal oursig
;
8706 error_no_arg (_("signal to handle"));
8709 /* Allocate and zero an array of flags for which signals to handle. */
8711 const size_t nsigs
= GDB_SIGNAL_LAST
;
8712 unsigned char sigs
[nsigs
] {};
8714 /* Break the command line up into args. */
8716 gdb_argv
built_argv (args
);
8718 /* Walk through the args, looking for signal oursigs, signal names, and
8719 actions. Signal numbers and signal names may be interspersed with
8720 actions, with the actions being performed for all signals cumulatively
8721 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8723 for (char *arg
: built_argv
)
8725 wordlen
= strlen (arg
);
8726 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8730 sigfirst
= siglast
= -1;
8732 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8734 /* Apply action to all signals except those used by the
8735 debugger. Silently skip those. */
8738 siglast
= nsigs
- 1;
8740 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8742 SET_SIGS (nsigs
, sigs
, signal_stop
);
8743 SET_SIGS (nsigs
, sigs
, signal_print
);
8745 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8747 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8749 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8751 SET_SIGS (nsigs
, sigs
, signal_print
);
8753 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8755 SET_SIGS (nsigs
, sigs
, signal_program
);
8757 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8759 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8761 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8763 SET_SIGS (nsigs
, sigs
, signal_program
);
8765 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8767 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8768 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8770 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8772 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8774 else if (digits
> 0)
8776 /* It is numeric. The numeric signal refers to our own
8777 internal signal numbering from target.h, not to host/target
8778 signal number. This is a feature; users really should be
8779 using symbolic names anyway, and the common ones like
8780 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8782 sigfirst
= siglast
= (int)
8783 gdb_signal_from_command (atoi (arg
));
8784 if (arg
[digits
] == '-')
8787 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8789 if (sigfirst
> siglast
)
8791 /* Bet he didn't figure we'd think of this case... */
8792 std::swap (sigfirst
, siglast
);
8797 oursig
= gdb_signal_from_name (arg
);
8798 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8800 sigfirst
= siglast
= (int) oursig
;
8804 /* Not a number and not a recognized flag word => complain. */
8805 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8809 /* If any signal numbers or symbol names were found, set flags for
8810 which signals to apply actions to. */
8812 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8814 switch ((enum gdb_signal
) signum
)
8816 case GDB_SIGNAL_TRAP
:
8817 case GDB_SIGNAL_INT
:
8818 if (!allsigs
&& !sigs
[signum
])
8820 if (query (_("%s is used by the debugger.\n\
8821 Are you sure you want to change it? "),
8822 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8827 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8831 case GDB_SIGNAL_DEFAULT
:
8832 case GDB_SIGNAL_UNKNOWN
:
8833 /* Make sure that "all" doesn't print these. */
8842 for (int signum
= 0; signum
< nsigs
; signum
++)
8845 signal_cache_update (-1);
8846 target_pass_signals (signal_pass
);
8847 target_program_signals (signal_program
);
8851 /* Show the results. */
8852 sig_print_header ();
8853 for (; signum
< nsigs
; signum
++)
8855 sig_print_info ((enum gdb_signal
) signum
);
8862 /* Complete the "handle" command. */
8865 handle_completer (struct cmd_list_element
*ignore
,
8866 completion_tracker
&tracker
,
8867 const char *text
, const char *word
)
8869 static const char * const keywords
[] =
8883 signal_completer (ignore
, tracker
, text
, word
);
8884 complete_on_enum (tracker
, keywords
, word
, word
);
8888 gdb_signal_from_command (int num
)
8890 if (num
>= 1 && num
<= 15)
8891 return (enum gdb_signal
) num
;
8892 error (_("Only signals 1-15 are valid as numeric signals.\n\
8893 Use \"info signals\" for a list of symbolic signals."));
8896 /* Print current contents of the tables set by the handle command.
8897 It is possible we should just be printing signals actually used
8898 by the current target (but for things to work right when switching
8899 targets, all signals should be in the signal tables). */
8902 info_signals_command (const char *signum_exp
, int from_tty
)
8904 enum gdb_signal oursig
;
8906 sig_print_header ();
8910 /* First see if this is a symbol name. */
8911 oursig
= gdb_signal_from_name (signum_exp
);
8912 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8914 /* No, try numeric. */
8916 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8918 sig_print_info (oursig
);
8922 printf_filtered ("\n");
8923 /* These ugly casts brought to you by the native VAX compiler. */
8924 for (oursig
= GDB_SIGNAL_FIRST
;
8925 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8926 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8930 if (oursig
!= GDB_SIGNAL_UNKNOWN
8931 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8932 sig_print_info (oursig
);
8935 printf_filtered (_("\nUse the \"handle\" command "
8936 "to change these tables.\n"));
8939 /* The $_siginfo convenience variable is a bit special. We don't know
8940 for sure the type of the value until we actually have a chance to
8941 fetch the data. The type can change depending on gdbarch, so it is
8942 also dependent on which thread you have selected.
8944 1. making $_siginfo be an internalvar that creates a new value on
8947 2. making the value of $_siginfo be an lval_computed value. */
8949 /* This function implements the lval_computed support for reading a
8953 siginfo_value_read (struct value
*v
)
8955 LONGEST transferred
;
8957 /* If we can access registers, so can we access $_siginfo. Likewise
8959 validate_registers_access ();
8962 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8964 value_contents_all_raw (v
),
8966 TYPE_LENGTH (value_type (v
)));
8968 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8969 error (_("Unable to read siginfo"));
8972 /* This function implements the lval_computed support for writing a
8976 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8978 LONGEST transferred
;
8980 /* If we can access registers, so can we access $_siginfo. Likewise
8982 validate_registers_access ();
8984 transferred
= target_write (current_top_target (),
8985 TARGET_OBJECT_SIGNAL_INFO
,
8987 value_contents_all_raw (fromval
),
8989 TYPE_LENGTH (value_type (fromval
)));
8991 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8992 error (_("Unable to write siginfo"));
8995 static const struct lval_funcs siginfo_value_funcs
=
9001 /* Return a new value with the correct type for the siginfo object of
9002 the current thread using architecture GDBARCH. Return a void value
9003 if there's no object available. */
9005 static struct value
*
9006 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9009 if (target_has_stack
9010 && inferior_ptid
!= null_ptid
9011 && gdbarch_get_siginfo_type_p (gdbarch
))
9013 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9015 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9018 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9022 /* infcall_suspend_state contains state about the program itself like its
9023 registers and any signal it received when it last stopped.
9024 This state must be restored regardless of how the inferior function call
9025 ends (either successfully, or after it hits a breakpoint or signal)
9026 if the program is to properly continue where it left off. */
9028 class infcall_suspend_state
9031 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9032 once the inferior function call has finished. */
9033 infcall_suspend_state (struct gdbarch
*gdbarch
,
9034 const struct thread_info
*tp
,
9035 struct regcache
*regcache
)
9036 : m_thread_suspend (tp
->suspend
),
9037 m_registers (new readonly_detached_regcache (*regcache
))
9039 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9041 if (gdbarch_get_siginfo_type_p (gdbarch
))
9043 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9044 size_t len
= TYPE_LENGTH (type
);
9046 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9048 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9049 siginfo_data
.get (), 0, len
) != len
)
9051 /* Errors ignored. */
9052 siginfo_data
.reset (nullptr);
9058 m_siginfo_gdbarch
= gdbarch
;
9059 m_siginfo_data
= std::move (siginfo_data
);
9063 /* Return a pointer to the stored register state. */
9065 readonly_detached_regcache
*registers () const
9067 return m_registers
.get ();
9070 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9072 void restore (struct gdbarch
*gdbarch
,
9073 struct thread_info
*tp
,
9074 struct regcache
*regcache
) const
9076 tp
->suspend
= m_thread_suspend
;
9078 if (m_siginfo_gdbarch
== gdbarch
)
9080 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9082 /* Errors ignored. */
9083 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9084 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9087 /* The inferior can be gone if the user types "print exit(0)"
9088 (and perhaps other times). */
9089 if (target_has_execution
)
9090 /* NB: The register write goes through to the target. */
9091 regcache
->restore (registers ());
9095 /* How the current thread stopped before the inferior function call was
9097 struct thread_suspend_state m_thread_suspend
;
9099 /* The registers before the inferior function call was executed. */
9100 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9102 /* Format of SIGINFO_DATA or NULL if it is not present. */
9103 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9105 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9106 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9107 content would be invalid. */
9108 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9111 infcall_suspend_state_up
9112 save_infcall_suspend_state ()
9114 struct thread_info
*tp
= inferior_thread ();
9115 struct regcache
*regcache
= get_current_regcache ();
9116 struct gdbarch
*gdbarch
= regcache
->arch ();
9118 infcall_suspend_state_up inf_state
9119 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9121 /* Having saved the current state, adjust the thread state, discarding
9122 any stop signal information. The stop signal is not useful when
9123 starting an inferior function call, and run_inferior_call will not use
9124 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9125 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9130 /* Restore inferior session state to INF_STATE. */
9133 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9135 struct thread_info
*tp
= inferior_thread ();
9136 struct regcache
*regcache
= get_current_regcache ();
9137 struct gdbarch
*gdbarch
= regcache
->arch ();
9139 inf_state
->restore (gdbarch
, tp
, regcache
);
9140 discard_infcall_suspend_state (inf_state
);
9144 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9149 readonly_detached_regcache
*
9150 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9152 return inf_state
->registers ();
9155 /* infcall_control_state contains state regarding gdb's control of the
9156 inferior itself like stepping control. It also contains session state like
9157 the user's currently selected frame. */
9159 struct infcall_control_state
9161 struct thread_control_state thread_control
;
9162 struct inferior_control_state inferior_control
;
9165 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9166 int stopped_by_random_signal
= 0;
9168 /* ID if the selected frame when the inferior function call was made. */
9169 struct frame_id selected_frame_id
{};
9172 /* Save all of the information associated with the inferior<==>gdb
9175 infcall_control_state_up
9176 save_infcall_control_state ()
9178 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9179 struct thread_info
*tp
= inferior_thread ();
9180 struct inferior
*inf
= current_inferior ();
9182 inf_status
->thread_control
= tp
->control
;
9183 inf_status
->inferior_control
= inf
->control
;
9185 tp
->control
.step_resume_breakpoint
= NULL
;
9186 tp
->control
.exception_resume_breakpoint
= NULL
;
9188 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9189 chain. If caller's caller is walking the chain, they'll be happier if we
9190 hand them back the original chain when restore_infcall_control_state is
9192 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9195 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9196 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9198 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9204 restore_selected_frame (const frame_id
&fid
)
9206 frame_info
*frame
= frame_find_by_id (fid
);
9208 /* If inf_status->selected_frame_id is NULL, there was no previously
9212 warning (_("Unable to restore previously selected frame."));
9216 select_frame (frame
);
9219 /* Restore inferior session state to INF_STATUS. */
9222 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9224 struct thread_info
*tp
= inferior_thread ();
9225 struct inferior
*inf
= current_inferior ();
9227 if (tp
->control
.step_resume_breakpoint
)
9228 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9230 if (tp
->control
.exception_resume_breakpoint
)
9231 tp
->control
.exception_resume_breakpoint
->disposition
9232 = disp_del_at_next_stop
;
9234 /* Handle the bpstat_copy of the chain. */
9235 bpstat_clear (&tp
->control
.stop_bpstat
);
9237 tp
->control
= inf_status
->thread_control
;
9238 inf
->control
= inf_status
->inferior_control
;
9241 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9242 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9244 if (target_has_stack
)
9246 /* The point of the try/catch is that if the stack is clobbered,
9247 walking the stack might encounter a garbage pointer and
9248 error() trying to dereference it. */
9251 restore_selected_frame (inf_status
->selected_frame_id
);
9253 catch (const gdb_exception_error
&ex
)
9255 exception_fprintf (gdb_stderr
, ex
,
9256 "Unable to restore previously selected frame:\n");
9257 /* Error in restoring the selected frame. Select the
9259 select_frame (get_current_frame ());
9267 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9269 if (inf_status
->thread_control
.step_resume_breakpoint
)
9270 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9271 = disp_del_at_next_stop
;
9273 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9274 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9275 = disp_del_at_next_stop
;
9277 /* See save_infcall_control_state for info on stop_bpstat. */
9278 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9286 clear_exit_convenience_vars (void)
9288 clear_internalvar (lookup_internalvar ("_exitsignal"));
9289 clear_internalvar (lookup_internalvar ("_exitcode"));
9293 /* User interface for reverse debugging:
9294 Set exec-direction / show exec-direction commands
9295 (returns error unless target implements to_set_exec_direction method). */
9297 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9298 static const char exec_forward
[] = "forward";
9299 static const char exec_reverse
[] = "reverse";
9300 static const char *exec_direction
= exec_forward
;
9301 static const char *const exec_direction_names
[] = {
9308 set_exec_direction_func (const char *args
, int from_tty
,
9309 struct cmd_list_element
*cmd
)
9311 if (target_can_execute_reverse
)
9313 if (!strcmp (exec_direction
, exec_forward
))
9314 execution_direction
= EXEC_FORWARD
;
9315 else if (!strcmp (exec_direction
, exec_reverse
))
9316 execution_direction
= EXEC_REVERSE
;
9320 exec_direction
= exec_forward
;
9321 error (_("Target does not support this operation."));
9326 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9327 struct cmd_list_element
*cmd
, const char *value
)
9329 switch (execution_direction
) {
9331 fprintf_filtered (out
, _("Forward.\n"));
9334 fprintf_filtered (out
, _("Reverse.\n"));
9337 internal_error (__FILE__
, __LINE__
,
9338 _("bogus execution_direction value: %d"),
9339 (int) execution_direction
);
9344 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9345 struct cmd_list_element
*c
, const char *value
)
9347 fprintf_filtered (file
, _("Resuming the execution of threads "
9348 "of all processes is %s.\n"), value
);
9351 /* Implementation of `siginfo' variable. */
9353 static const struct internalvar_funcs siginfo_funcs
=
9360 /* Callback for infrun's target events source. This is marked when a
9361 thread has a pending status to process. */
9364 infrun_async_inferior_event_handler (gdb_client_data data
)
9366 inferior_event_handler (INF_REG_EVENT
, NULL
);
9369 void _initialize_infrun ();
9371 _initialize_infrun ()
9373 struct cmd_list_element
*c
;
9375 /* Register extra event sources in the event loop. */
9376 infrun_async_inferior_event_token
9377 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9379 add_info ("signals", info_signals_command
, _("\
9380 What debugger does when program gets various signals.\n\
9381 Specify a signal as argument to print info on that signal only."));
9382 add_info_alias ("handle", "signals", 0);
9384 c
= add_com ("handle", class_run
, handle_command
, _("\
9385 Specify how to handle signals.\n\
9386 Usage: handle SIGNAL [ACTIONS]\n\
9387 Args are signals and actions to apply to those signals.\n\
9388 If no actions are specified, the current settings for the specified signals\n\
9389 will be displayed instead.\n\
9391 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9392 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9393 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9394 The special arg \"all\" is recognized to mean all signals except those\n\
9395 used by the debugger, typically SIGTRAP and SIGINT.\n\
9397 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9398 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9399 Stop means reenter debugger if this signal happens (implies print).\n\
9400 Print means print a message if this signal happens.\n\
9401 Pass means let program see this signal; otherwise program doesn't know.\n\
9402 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9403 Pass and Stop may be combined.\n\
9405 Multiple signals may be specified. Signal numbers and signal names\n\
9406 may be interspersed with actions, with the actions being performed for\n\
9407 all signals cumulatively specified."));
9408 set_cmd_completer (c
, handle_completer
);
9411 stop_command
= add_cmd ("stop", class_obscure
,
9412 not_just_help_class_command
, _("\
9413 There is no `stop' command, but you can set a hook on `stop'.\n\
9414 This allows you to set a list of commands to be run each time execution\n\
9415 of the program stops."), &cmdlist
);
9417 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9418 Set inferior debugging."), _("\
9419 Show inferior debugging."), _("\
9420 When non-zero, inferior specific debugging is enabled."),
9423 &setdebuglist
, &showdebuglist
);
9425 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9426 &debug_displaced
, _("\
9427 Set displaced stepping debugging."), _("\
9428 Show displaced stepping debugging."), _("\
9429 When non-zero, displaced stepping specific debugging is enabled."),
9431 show_debug_displaced
,
9432 &setdebuglist
, &showdebuglist
);
9434 add_setshow_boolean_cmd ("non-stop", no_class
,
9436 Set whether gdb controls the inferior in non-stop mode."), _("\
9437 Show whether gdb controls the inferior in non-stop mode."), _("\
9438 When debugging a multi-threaded program and this setting is\n\
9439 off (the default, also called all-stop mode), when one thread stops\n\
9440 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9441 all other threads in the program while you interact with the thread of\n\
9442 interest. When you continue or step a thread, you can allow the other\n\
9443 threads to run, or have them remain stopped, but while you inspect any\n\
9444 thread's state, all threads stop.\n\
9446 In non-stop mode, when one thread stops, other threads can continue\n\
9447 to run freely. You'll be able to step each thread independently,\n\
9448 leave it stopped or free to run as needed."),
9454 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9457 signal_print
[i
] = 1;
9458 signal_program
[i
] = 1;
9459 signal_catch
[i
] = 0;
9462 /* Signals caused by debugger's own actions should not be given to
9463 the program afterwards.
9465 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9466 explicitly specifies that it should be delivered to the target
9467 program. Typically, that would occur when a user is debugging a
9468 target monitor on a simulator: the target monitor sets a
9469 breakpoint; the simulator encounters this breakpoint and halts
9470 the simulation handing control to GDB; GDB, noting that the stop
9471 address doesn't map to any known breakpoint, returns control back
9472 to the simulator; the simulator then delivers the hardware
9473 equivalent of a GDB_SIGNAL_TRAP to the program being
9475 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9476 signal_program
[GDB_SIGNAL_INT
] = 0;
9478 /* Signals that are not errors should not normally enter the debugger. */
9479 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9480 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9481 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9482 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9483 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9484 signal_print
[GDB_SIGNAL_PROF
] = 0;
9485 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9486 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9487 signal_stop
[GDB_SIGNAL_IO
] = 0;
9488 signal_print
[GDB_SIGNAL_IO
] = 0;
9489 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9490 signal_print
[GDB_SIGNAL_POLL
] = 0;
9491 signal_stop
[GDB_SIGNAL_URG
] = 0;
9492 signal_print
[GDB_SIGNAL_URG
] = 0;
9493 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9494 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9495 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9496 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9498 /* These signals are used internally by user-level thread
9499 implementations. (See signal(5) on Solaris.) Like the above
9500 signals, a healthy program receives and handles them as part of
9501 its normal operation. */
9502 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9503 signal_print
[GDB_SIGNAL_LWP
] = 0;
9504 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9505 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9506 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9507 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9508 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9509 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9511 /* Update cached state. */
9512 signal_cache_update (-1);
9514 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9515 &stop_on_solib_events
, _("\
9516 Set stopping for shared library events."), _("\
9517 Show stopping for shared library events."), _("\
9518 If nonzero, gdb will give control to the user when the dynamic linker\n\
9519 notifies gdb of shared library events. The most common event of interest\n\
9520 to the user would be loading/unloading of a new library."),
9521 set_stop_on_solib_events
,
9522 show_stop_on_solib_events
,
9523 &setlist
, &showlist
);
9525 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9526 follow_fork_mode_kind_names
,
9527 &follow_fork_mode_string
, _("\
9528 Set debugger response to a program call of fork or vfork."), _("\
9529 Show debugger response to a program call of fork or vfork."), _("\
9530 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9531 parent - the original process is debugged after a fork\n\
9532 child - the new process is debugged after a fork\n\
9533 The unfollowed process will continue to run.\n\
9534 By default, the debugger will follow the parent process."),
9536 show_follow_fork_mode_string
,
9537 &setlist
, &showlist
);
9539 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9540 follow_exec_mode_names
,
9541 &follow_exec_mode_string
, _("\
9542 Set debugger response to a program call of exec."), _("\
9543 Show debugger response to a program call of exec."), _("\
9544 An exec call replaces the program image of a process.\n\
9546 follow-exec-mode can be:\n\
9548 new - the debugger creates a new inferior and rebinds the process\n\
9549 to this new inferior. The program the process was running before\n\
9550 the exec call can be restarted afterwards by restarting the original\n\
9553 same - the debugger keeps the process bound to the same inferior.\n\
9554 The new executable image replaces the previous executable loaded in\n\
9555 the inferior. Restarting the inferior after the exec call restarts\n\
9556 the executable the process was running after the exec call.\n\
9558 By default, the debugger will use the same inferior."),
9560 show_follow_exec_mode_string
,
9561 &setlist
, &showlist
);
9563 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9564 scheduler_enums
, &scheduler_mode
, _("\
9565 Set mode for locking scheduler during execution."), _("\
9566 Show mode for locking scheduler during execution."), _("\
9567 off == no locking (threads may preempt at any time)\n\
9568 on == full locking (no thread except the current thread may run)\n\
9569 This applies to both normal execution and replay mode.\n\
9570 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9571 In this mode, other threads may run during other commands.\n\
9572 This applies to both normal execution and replay mode.\n\
9573 replay == scheduler locked in replay mode and unlocked during normal execution."),
9574 set_schedlock_func
, /* traps on target vector */
9575 show_scheduler_mode
,
9576 &setlist
, &showlist
);
9578 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9579 Set mode for resuming threads of all processes."), _("\
9580 Show mode for resuming threads of all processes."), _("\
9581 When on, execution commands (such as 'continue' or 'next') resume all\n\
9582 threads of all processes. When off (which is the default), execution\n\
9583 commands only resume the threads of the current process. The set of\n\
9584 threads that are resumed is further refined by the scheduler-locking\n\
9585 mode (see help set scheduler-locking)."),
9587 show_schedule_multiple
,
9588 &setlist
, &showlist
);
9590 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9591 Set mode of the step operation."), _("\
9592 Show mode of the step operation."), _("\
9593 When set, doing a step over a function without debug line information\n\
9594 will stop at the first instruction of that function. Otherwise, the\n\
9595 function is skipped and the step command stops at a different source line."),
9597 show_step_stop_if_no_debug
,
9598 &setlist
, &showlist
);
9600 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9601 &can_use_displaced_stepping
, _("\
9602 Set debugger's willingness to use displaced stepping."), _("\
9603 Show debugger's willingness to use displaced stepping."), _("\
9604 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9605 supported by the target architecture. If off, gdb will not use displaced\n\
9606 stepping to step over breakpoints, even if such is supported by the target\n\
9607 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9608 if the target architecture supports it and non-stop mode is active, but will not\n\
9609 use it in all-stop mode (see help set non-stop)."),
9611 show_can_use_displaced_stepping
,
9612 &setlist
, &showlist
);
9614 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9615 &exec_direction
, _("Set direction of execution.\n\
9616 Options are 'forward' or 'reverse'."),
9617 _("Show direction of execution (forward/reverse)."),
9618 _("Tells gdb whether to execute forward or backward."),
9619 set_exec_direction_func
, show_exec_direction_func
,
9620 &setlist
, &showlist
);
9622 /* Set/show detach-on-fork: user-settable mode. */
9624 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9625 Set whether gdb will detach the child of a fork."), _("\
9626 Show whether gdb will detach the child of a fork."), _("\
9627 Tells gdb whether to detach the child of a fork."),
9628 NULL
, NULL
, &setlist
, &showlist
);
9630 /* Set/show disable address space randomization mode. */
9632 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9633 &disable_randomization
, _("\
9634 Set disabling of debuggee's virtual address space randomization."), _("\
9635 Show disabling of debuggee's virtual address space randomization."), _("\
9636 When this mode is on (which is the default), randomization of the virtual\n\
9637 address space is disabled. Standalone programs run with the randomization\n\
9638 enabled by default on some platforms."),
9639 &set_disable_randomization
,
9640 &show_disable_randomization
,
9641 &setlist
, &showlist
);
9643 /* ptid initializations */
9644 inferior_ptid
= null_ptid
;
9645 target_last_wait_ptid
= minus_one_ptid
;
9647 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9648 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9649 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9650 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9652 /* Explicitly create without lookup, since that tries to create a
9653 value with a void typed value, and when we get here, gdbarch
9654 isn't initialized yet. At this point, we're quite sure there
9655 isn't another convenience variable of the same name. */
9656 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9658 add_setshow_boolean_cmd ("observer", no_class
,
9659 &observer_mode_1
, _("\
9660 Set whether gdb controls the inferior in observer mode."), _("\
9661 Show whether gdb controls the inferior in observer mode."), _("\
9662 In observer mode, GDB can get data from the inferior, but not\n\
9663 affect its execution. Registers and memory may not be changed,\n\
9664 breakpoints may not be set, and the program cannot be interrupted\n\