1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "target-connection.h"
32 #include "gdbthread.h"
39 #include "observable.h"
44 #include "mi/mi-common.h"
45 #include "event-top.h"
47 #include "record-full.h"
48 #include "inline-frame.h"
50 #include "tracepoint.h"
54 #include "completer.h"
55 #include "target-descriptions.h"
56 #include "target-dcache.h"
59 #include "gdbsupport/event-loop.h"
60 #include "thread-fsm.h"
61 #include "gdbsupport/enum-flags.h"
62 #include "progspace-and-thread.h"
63 #include "gdbsupport/gdb_optional.h"
64 #include "arch-utils.h"
65 #include "gdbsupport/scope-exit.h"
66 #include "gdbsupport/forward-scope-exit.h"
67 #include "gdbsupport/gdb_select.h"
68 #include <unordered_map>
69 #include "async-event.h"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal
);
75 static void sig_print_header (void);
77 static void follow_inferior_reset_breakpoints (void);
79 static int currently_stepping (struct thread_info
*tp
);
81 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
83 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
85 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
87 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
89 static void resume (gdb_signal sig
);
91 static void wait_for_inferior (inferior
*inf
);
93 /* Asynchronous signal handler registered as event loop source for
94 when we have pending events ready to be passed to the core. */
95 static struct async_event_handler
*infrun_async_inferior_event_token
;
97 /* Stores whether infrun_async was previously enabled or disabled.
98 Starts off as -1, indicating "never enabled/disabled". */
99 static int infrun_is_async
= -1;
104 infrun_async (int enable
)
106 if (infrun_is_async
!= enable
)
108 infrun_is_async
= enable
;
111 fprintf_unfiltered (gdb_stdlog
,
112 "infrun: infrun_async(%d)\n",
116 mark_async_event_handler (infrun_async_inferior_event_token
);
118 clear_async_event_handler (infrun_async_inferior_event_token
);
125 mark_infrun_async_event_handler (void)
127 mark_async_event_handler (infrun_async_inferior_event_token
);
130 /* When set, stop the 'step' command if we enter a function which has
131 no line number information. The normal behavior is that we step
132 over such function. */
133 bool step_stop_if_no_debug
= false;
135 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
136 struct cmd_list_element
*c
, const char *value
)
138 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
141 /* proceed and normal_stop use this to notify the user when the
142 inferior stopped in a different thread than it had been running
145 static ptid_t previous_inferior_ptid
;
147 /* If set (default for legacy reasons), when following a fork, GDB
148 will detach from one of the fork branches, child or parent.
149 Exactly which branch is detached depends on 'set follow-fork-mode'
152 static bool detach_fork
= true;
154 bool debug_displaced
= false;
156 show_debug_displaced (struct ui_file
*file
, int from_tty
,
157 struct cmd_list_element
*c
, const char *value
)
159 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
162 unsigned int debug_infrun
= 0;
164 show_debug_infrun (struct ui_file
*file
, int from_tty
,
165 struct cmd_list_element
*c
, const char *value
)
167 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
171 /* Support for disabling address space randomization. */
173 bool disable_randomization
= true;
176 show_disable_randomization (struct ui_file
*file
, int from_tty
,
177 struct cmd_list_element
*c
, const char *value
)
179 if (target_supports_disable_randomization ())
180 fprintf_filtered (file
,
181 _("Disabling randomization of debuggee's "
182 "virtual address space is %s.\n"),
185 fputs_filtered (_("Disabling randomization of debuggee's "
186 "virtual address space is unsupported on\n"
187 "this platform.\n"), file
);
191 set_disable_randomization (const char *args
, int from_tty
,
192 struct cmd_list_element
*c
)
194 if (!target_supports_disable_randomization ())
195 error (_("Disabling randomization of debuggee's "
196 "virtual address space is unsupported on\n"
200 /* User interface for non-stop mode. */
202 bool non_stop
= false;
203 static bool non_stop_1
= false;
206 set_non_stop (const char *args
, int from_tty
,
207 struct cmd_list_element
*c
)
209 if (target_has_execution
)
211 non_stop_1
= non_stop
;
212 error (_("Cannot change this setting while the inferior is running."));
215 non_stop
= non_stop_1
;
219 show_non_stop (struct ui_file
*file
, int from_tty
,
220 struct cmd_list_element
*c
, const char *value
)
222 fprintf_filtered (file
,
223 _("Controlling the inferior in non-stop mode is %s.\n"),
227 /* "Observer mode" is somewhat like a more extreme version of
228 non-stop, in which all GDB operations that might affect the
229 target's execution have been disabled. */
231 bool observer_mode
= false;
232 static bool observer_mode_1
= false;
235 set_observer_mode (const char *args
, int from_tty
,
236 struct cmd_list_element
*c
)
238 if (target_has_execution
)
240 observer_mode_1
= observer_mode
;
241 error (_("Cannot change this setting while the inferior is running."));
244 observer_mode
= observer_mode_1
;
246 may_write_registers
= !observer_mode
;
247 may_write_memory
= !observer_mode
;
248 may_insert_breakpoints
= !observer_mode
;
249 may_insert_tracepoints
= !observer_mode
;
250 /* We can insert fast tracepoints in or out of observer mode,
251 but enable them if we're going into this mode. */
253 may_insert_fast_tracepoints
= true;
254 may_stop
= !observer_mode
;
255 update_target_permissions ();
257 /* Going *into* observer mode we must force non-stop, then
258 going out we leave it that way. */
261 pagination_enabled
= 0;
262 non_stop
= non_stop_1
= true;
266 printf_filtered (_("Observer mode is now %s.\n"),
267 (observer_mode
? "on" : "off"));
271 show_observer_mode (struct ui_file
*file
, int from_tty
,
272 struct cmd_list_element
*c
, const char *value
)
274 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
277 /* This updates the value of observer mode based on changes in
278 permissions. Note that we are deliberately ignoring the values of
279 may-write-registers and may-write-memory, since the user may have
280 reason to enable these during a session, for instance to turn on a
281 debugging-related global. */
284 update_observer_mode (void)
286 bool newval
= (!may_insert_breakpoints
287 && !may_insert_tracepoints
288 && may_insert_fast_tracepoints
292 /* Let the user know if things change. */
293 if (newval
!= observer_mode
)
294 printf_filtered (_("Observer mode is now %s.\n"),
295 (newval
? "on" : "off"));
297 observer_mode
= observer_mode_1
= newval
;
300 /* Tables of how to react to signals; the user sets them. */
302 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
303 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
304 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
306 /* Table of signals that are registered with "catch signal". A
307 non-zero entry indicates that the signal is caught by some "catch
309 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
311 /* Table of signals that the target may silently handle.
312 This is automatically determined from the flags above,
313 and simply cached here. */
314 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
316 #define SET_SIGS(nsigs,sigs,flags) \
318 int signum = (nsigs); \
319 while (signum-- > 0) \
320 if ((sigs)[signum]) \
321 (flags)[signum] = 1; \
324 #define UNSET_SIGS(nsigs,sigs,flags) \
326 int signum = (nsigs); \
327 while (signum-- > 0) \
328 if ((sigs)[signum]) \
329 (flags)[signum] = 0; \
332 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
333 this function is to avoid exporting `signal_program'. */
336 update_signals_program_target (void)
338 target_program_signals (signal_program
);
341 /* Value to pass to target_resume() to cause all threads to resume. */
343 #define RESUME_ALL minus_one_ptid
345 /* Command list pointer for the "stop" placeholder. */
347 static struct cmd_list_element
*stop_command
;
349 /* Nonzero if we want to give control to the user when we're notified
350 of shared library events by the dynamic linker. */
351 int stop_on_solib_events
;
353 /* Enable or disable optional shared library event breakpoints
354 as appropriate when the above flag is changed. */
357 set_stop_on_solib_events (const char *args
,
358 int from_tty
, struct cmd_list_element
*c
)
360 update_solib_breakpoints ();
364 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
365 struct cmd_list_element
*c
, const char *value
)
367 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
371 /* Nonzero after stop if current stack frame should be printed. */
373 static int stop_print_frame
;
375 /* This is a cached copy of the target/ptid/waitstatus of the last
376 event returned by target_wait()/deprecated_target_wait_hook().
377 This information is returned by get_last_target_status(). */
378 static process_stratum_target
*target_last_proc_target
;
379 static ptid_t target_last_wait_ptid
;
380 static struct target_waitstatus target_last_waitstatus
;
382 void init_thread_stepping_state (struct thread_info
*tss
);
384 static const char follow_fork_mode_child
[] = "child";
385 static const char follow_fork_mode_parent
[] = "parent";
387 static const char *const follow_fork_mode_kind_names
[] = {
388 follow_fork_mode_child
,
389 follow_fork_mode_parent
,
393 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
395 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
396 struct cmd_list_element
*c
, const char *value
)
398 fprintf_filtered (file
,
399 _("Debugger response to a program "
400 "call of fork or vfork is \"%s\".\n"),
405 /* Handle changes to the inferior list based on the type of fork,
406 which process is being followed, and whether the other process
407 should be detached. On entry inferior_ptid must be the ptid of
408 the fork parent. At return inferior_ptid is the ptid of the
409 followed inferior. */
412 follow_fork_inferior (bool follow_child
, bool detach_fork
)
415 ptid_t parent_ptid
, child_ptid
;
417 has_vforked
= (inferior_thread ()->pending_follow
.kind
418 == TARGET_WAITKIND_VFORKED
);
419 parent_ptid
= inferior_ptid
;
420 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
423 && !non_stop
/* Non-stop always resumes both branches. */
424 && current_ui
->prompt_state
== PROMPT_BLOCKED
425 && !(follow_child
|| detach_fork
|| sched_multi
))
427 /* The parent stays blocked inside the vfork syscall until the
428 child execs or exits. If we don't let the child run, then
429 the parent stays blocked. If we're telling the parent to run
430 in the foreground, the user will not be able to ctrl-c to get
431 back the terminal, effectively hanging the debug session. */
432 fprintf_filtered (gdb_stderr
, _("\
433 Can not resume the parent process over vfork in the foreground while\n\
434 holding the child stopped. Try \"set detach-on-fork\" or \
435 \"set schedule-multiple\".\n"));
441 /* Detach new forked process? */
444 /* Before detaching from the child, remove all breakpoints
445 from it. If we forked, then this has already been taken
446 care of by infrun.c. If we vforked however, any
447 breakpoint inserted in the parent is visible in the
448 child, even those added while stopped in a vfork
449 catchpoint. This will remove the breakpoints from the
450 parent also, but they'll be reinserted below. */
453 /* Keep breakpoints list in sync. */
454 remove_breakpoints_inf (current_inferior ());
457 if (print_inferior_events
)
459 /* Ensure that we have a process ptid. */
460 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
462 target_terminal::ours_for_output ();
463 fprintf_filtered (gdb_stdlog
,
464 _("[Detaching after %s from child %s]\n"),
465 has_vforked
? "vfork" : "fork",
466 target_pid_to_str (process_ptid
).c_str ());
471 struct inferior
*parent_inf
, *child_inf
;
473 /* Add process to GDB's tables. */
474 child_inf
= add_inferior (child_ptid
.pid ());
476 parent_inf
= current_inferior ();
477 child_inf
->attach_flag
= parent_inf
->attach_flag
;
478 copy_terminal_info (child_inf
, parent_inf
);
479 child_inf
->gdbarch
= parent_inf
->gdbarch
;
480 copy_inferior_target_desc_info (child_inf
, parent_inf
);
482 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
484 set_current_inferior (child_inf
);
485 switch_to_no_thread ();
486 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
487 push_target (parent_inf
->process_target ());
488 add_thread_silent (child_inf
->process_target (), child_ptid
);
489 inferior_ptid
= child_ptid
;
491 /* If this is a vfork child, then the address-space is
492 shared with the parent. */
495 child_inf
->pspace
= parent_inf
->pspace
;
496 child_inf
->aspace
= parent_inf
->aspace
;
500 /* The parent will be frozen until the child is done
501 with the shared region. Keep track of the
503 child_inf
->vfork_parent
= parent_inf
;
504 child_inf
->pending_detach
= 0;
505 parent_inf
->vfork_child
= child_inf
;
506 parent_inf
->pending_detach
= 0;
510 child_inf
->aspace
= new_address_space ();
511 child_inf
->pspace
= new program_space (child_inf
->aspace
);
512 child_inf
->removable
= 1;
513 set_current_program_space (child_inf
->pspace
);
514 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
516 /* Let the shared library layer (e.g., solib-svr4) learn
517 about this new process, relocate the cloned exec, pull
518 in shared libraries, and install the solib event
519 breakpoint. If a "cloned-VM" event was propagated
520 better throughout the core, this wouldn't be
522 solib_create_inferior_hook (0);
528 struct inferior
*parent_inf
;
530 parent_inf
= current_inferior ();
532 /* If we detached from the child, then we have to be careful
533 to not insert breakpoints in the parent until the child
534 is done with the shared memory region. However, if we're
535 staying attached to the child, then we can and should
536 insert breakpoints, so that we can debug it. A
537 subsequent child exec or exit is enough to know when does
538 the child stops using the parent's address space. */
539 parent_inf
->waiting_for_vfork_done
= detach_fork
;
540 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
545 /* Follow the child. */
546 struct inferior
*parent_inf
, *child_inf
;
547 struct program_space
*parent_pspace
;
549 if (print_inferior_events
)
551 std::string parent_pid
= target_pid_to_str (parent_ptid
);
552 std::string child_pid
= target_pid_to_str (child_ptid
);
554 target_terminal::ours_for_output ();
555 fprintf_filtered (gdb_stdlog
,
556 _("[Attaching after %s %s to child %s]\n"),
558 has_vforked
? "vfork" : "fork",
562 /* Add the new inferior first, so that the target_detach below
563 doesn't unpush the target. */
565 child_inf
= add_inferior (child_ptid
.pid ());
567 parent_inf
= current_inferior ();
568 child_inf
->attach_flag
= parent_inf
->attach_flag
;
569 copy_terminal_info (child_inf
, parent_inf
);
570 child_inf
->gdbarch
= parent_inf
->gdbarch
;
571 copy_inferior_target_desc_info (child_inf
, parent_inf
);
573 parent_pspace
= parent_inf
->pspace
;
575 process_stratum_target
*target
= parent_inf
->process_target ();
578 /* Hold a strong reference to the target while (maybe)
579 detaching the parent. Otherwise detaching could close the
581 auto target_ref
= target_ops_ref::new_reference (target
);
583 /* If we're vforking, we want to hold on to the parent until
584 the child exits or execs. At child exec or exit time we
585 can remove the old breakpoints from the parent and detach
586 or resume debugging it. Otherwise, detach the parent now;
587 we'll want to reuse it's program/address spaces, but we
588 can't set them to the child before removing breakpoints
589 from the parent, otherwise, the breakpoints module could
590 decide to remove breakpoints from the wrong process (since
591 they'd be assigned to the same address space). */
595 gdb_assert (child_inf
->vfork_parent
== NULL
);
596 gdb_assert (parent_inf
->vfork_child
== NULL
);
597 child_inf
->vfork_parent
= parent_inf
;
598 child_inf
->pending_detach
= 0;
599 parent_inf
->vfork_child
= child_inf
;
600 parent_inf
->pending_detach
= detach_fork
;
601 parent_inf
->waiting_for_vfork_done
= 0;
603 else if (detach_fork
)
605 if (print_inferior_events
)
607 /* Ensure that we have a process ptid. */
608 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
610 target_terminal::ours_for_output ();
611 fprintf_filtered (gdb_stdlog
,
612 _("[Detaching after fork from "
614 target_pid_to_str (process_ptid
).c_str ());
617 target_detach (parent_inf
, 0);
621 /* Note that the detach above makes PARENT_INF dangling. */
623 /* Add the child thread to the appropriate lists, and switch
624 to this new thread, before cloning the program space, and
625 informing the solib layer about this new process. */
627 set_current_inferior (child_inf
);
628 push_target (target
);
631 add_thread_silent (target
, child_ptid
);
632 inferior_ptid
= child_ptid
;
634 /* If this is a vfork child, then the address-space is shared
635 with the parent. If we detached from the parent, then we can
636 reuse the parent's program/address spaces. */
637 if (has_vforked
|| detach_fork
)
639 child_inf
->pspace
= parent_pspace
;
640 child_inf
->aspace
= child_inf
->pspace
->aspace
;
646 child_inf
->aspace
= new_address_space ();
647 child_inf
->pspace
= new program_space (child_inf
->aspace
);
648 child_inf
->removable
= 1;
649 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
650 set_current_program_space (child_inf
->pspace
);
651 clone_program_space (child_inf
->pspace
, parent_pspace
);
653 /* Let the shared library layer (e.g., solib-svr4) learn
654 about this new process, relocate the cloned exec, pull in
655 shared libraries, and install the solib event breakpoint.
656 If a "cloned-VM" event was propagated better throughout
657 the core, this wouldn't be required. */
658 solib_create_inferior_hook (0);
662 return target_follow_fork (follow_child
, detach_fork
);
665 /* Tell the target to follow the fork we're stopped at. Returns true
666 if the inferior should be resumed; false, if the target for some
667 reason decided it's best not to resume. */
672 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
673 bool should_resume
= true;
674 struct thread_info
*tp
;
676 /* Copy user stepping state to the new inferior thread. FIXME: the
677 followed fork child thread should have a copy of most of the
678 parent thread structure's run control related fields, not just these.
679 Initialized to avoid "may be used uninitialized" warnings from gcc. */
680 struct breakpoint
*step_resume_breakpoint
= NULL
;
681 struct breakpoint
*exception_resume_breakpoint
= NULL
;
682 CORE_ADDR step_range_start
= 0;
683 CORE_ADDR step_range_end
= 0;
684 int current_line
= 0;
685 symtab
*current_symtab
= NULL
;
686 struct frame_id step_frame_id
= { 0 };
687 struct thread_fsm
*thread_fsm
= NULL
;
691 process_stratum_target
*wait_target
;
693 struct target_waitstatus wait_status
;
695 /* Get the last target status returned by target_wait(). */
696 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
698 /* If not stopped at a fork event, then there's nothing else to
700 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
701 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
704 /* Check if we switched over from WAIT_PTID, since the event was
706 if (wait_ptid
!= minus_one_ptid
707 && (current_inferior ()->process_target () != wait_target
708 || inferior_ptid
!= wait_ptid
))
710 /* We did. Switch back to WAIT_PTID thread, to tell the
711 target to follow it (in either direction). We'll
712 afterwards refuse to resume, and inform the user what
714 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
715 switch_to_thread (wait_thread
);
716 should_resume
= false;
720 tp
= inferior_thread ();
722 /* If there were any forks/vforks that were caught and are now to be
723 followed, then do so now. */
724 switch (tp
->pending_follow
.kind
)
726 case TARGET_WAITKIND_FORKED
:
727 case TARGET_WAITKIND_VFORKED
:
729 ptid_t parent
, child
;
731 /* If the user did a next/step, etc, over a fork call,
732 preserve the stepping state in the fork child. */
733 if (follow_child
&& should_resume
)
735 step_resume_breakpoint
= clone_momentary_breakpoint
736 (tp
->control
.step_resume_breakpoint
);
737 step_range_start
= tp
->control
.step_range_start
;
738 step_range_end
= tp
->control
.step_range_end
;
739 current_line
= tp
->current_line
;
740 current_symtab
= tp
->current_symtab
;
741 step_frame_id
= tp
->control
.step_frame_id
;
742 exception_resume_breakpoint
743 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
744 thread_fsm
= tp
->thread_fsm
;
746 /* For now, delete the parent's sr breakpoint, otherwise,
747 parent/child sr breakpoints are considered duplicates,
748 and the child version will not be installed. Remove
749 this when the breakpoints module becomes aware of
750 inferiors and address spaces. */
751 delete_step_resume_breakpoint (tp
);
752 tp
->control
.step_range_start
= 0;
753 tp
->control
.step_range_end
= 0;
754 tp
->control
.step_frame_id
= null_frame_id
;
755 delete_exception_resume_breakpoint (tp
);
756 tp
->thread_fsm
= NULL
;
759 parent
= inferior_ptid
;
760 child
= tp
->pending_follow
.value
.related_pid
;
762 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
763 /* Set up inferior(s) as specified by the caller, and tell the
764 target to do whatever is necessary to follow either parent
766 if (follow_fork_inferior (follow_child
, detach_fork
))
768 /* Target refused to follow, or there's some other reason
769 we shouldn't resume. */
774 /* This pending follow fork event is now handled, one way
775 or another. The previous selected thread may be gone
776 from the lists by now, but if it is still around, need
777 to clear the pending follow request. */
778 tp
= find_thread_ptid (parent_targ
, parent
);
780 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
782 /* This makes sure we don't try to apply the "Switched
783 over from WAIT_PID" logic above. */
784 nullify_last_target_wait_ptid ();
786 /* If we followed the child, switch to it... */
789 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
790 switch_to_thread (child_thr
);
792 /* ... and preserve the stepping state, in case the
793 user was stepping over the fork call. */
796 tp
= inferior_thread ();
797 tp
->control
.step_resume_breakpoint
798 = step_resume_breakpoint
;
799 tp
->control
.step_range_start
= step_range_start
;
800 tp
->control
.step_range_end
= step_range_end
;
801 tp
->current_line
= current_line
;
802 tp
->current_symtab
= current_symtab
;
803 tp
->control
.step_frame_id
= step_frame_id
;
804 tp
->control
.exception_resume_breakpoint
805 = exception_resume_breakpoint
;
806 tp
->thread_fsm
= thread_fsm
;
810 /* If we get here, it was because we're trying to
811 resume from a fork catchpoint, but, the user
812 has switched threads away from the thread that
813 forked. In that case, the resume command
814 issued is most likely not applicable to the
815 child, so just warn, and refuse to resume. */
816 warning (_("Not resuming: switched threads "
817 "before following fork child."));
820 /* Reset breakpoints in the child as appropriate. */
821 follow_inferior_reset_breakpoints ();
826 case TARGET_WAITKIND_SPURIOUS
:
827 /* Nothing to follow. */
830 internal_error (__FILE__
, __LINE__
,
831 "Unexpected pending_follow.kind %d\n",
832 tp
->pending_follow
.kind
);
836 return should_resume
;
840 follow_inferior_reset_breakpoints (void)
842 struct thread_info
*tp
= inferior_thread ();
844 /* Was there a step_resume breakpoint? (There was if the user
845 did a "next" at the fork() call.) If so, explicitly reset its
846 thread number. Cloned step_resume breakpoints are disabled on
847 creation, so enable it here now that it is associated with the
850 step_resumes are a form of bp that are made to be per-thread.
851 Since we created the step_resume bp when the parent process
852 was being debugged, and now are switching to the child process,
853 from the breakpoint package's viewpoint, that's a switch of
854 "threads". We must update the bp's notion of which thread
855 it is for, or it'll be ignored when it triggers. */
857 if (tp
->control
.step_resume_breakpoint
)
859 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
860 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
863 /* Treat exception_resume breakpoints like step_resume breakpoints. */
864 if (tp
->control
.exception_resume_breakpoint
)
866 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
867 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
870 /* Reinsert all breakpoints in the child. The user may have set
871 breakpoints after catching the fork, in which case those
872 were never set in the child, but only in the parent. This makes
873 sure the inserted breakpoints match the breakpoint list. */
875 breakpoint_re_set ();
876 insert_breakpoints ();
879 /* The child has exited or execed: resume threads of the parent the
880 user wanted to be executing. */
883 proceed_after_vfork_done (struct thread_info
*thread
,
886 int pid
= * (int *) arg
;
888 if (thread
->ptid
.pid () == pid
889 && thread
->state
== THREAD_RUNNING
890 && !thread
->executing
891 && !thread
->stop_requested
892 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
895 fprintf_unfiltered (gdb_stdlog
,
896 "infrun: resuming vfork parent thread %s\n",
897 target_pid_to_str (thread
->ptid
).c_str ());
899 switch_to_thread (thread
);
900 clear_proceed_status (0);
901 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
907 /* Save/restore inferior_ptid, current program space and current
908 inferior. Only use this if the current context points at an exited
909 inferior (and therefore there's no current thread to save). */
910 class scoped_restore_exited_inferior
913 scoped_restore_exited_inferior ()
914 : m_saved_ptid (&inferior_ptid
)
918 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
919 scoped_restore_current_program_space m_pspace
;
920 scoped_restore_current_inferior m_inferior
;
923 /* Called whenever we notice an exec or exit event, to handle
924 detaching or resuming a vfork parent. */
927 handle_vfork_child_exec_or_exit (int exec
)
929 struct inferior
*inf
= current_inferior ();
931 if (inf
->vfork_parent
)
933 int resume_parent
= -1;
935 /* This exec or exit marks the end of the shared memory region
936 between the parent and the child. Break the bonds. */
937 inferior
*vfork_parent
= inf
->vfork_parent
;
938 inf
->vfork_parent
->vfork_child
= NULL
;
939 inf
->vfork_parent
= NULL
;
941 /* If the user wanted to detach from the parent, now is the
943 if (vfork_parent
->pending_detach
)
945 struct thread_info
*tp
;
946 struct program_space
*pspace
;
947 struct address_space
*aspace
;
949 /* follow-fork child, detach-on-fork on. */
951 vfork_parent
->pending_detach
= 0;
953 gdb::optional
<scoped_restore_exited_inferior
>
954 maybe_restore_inferior
;
955 gdb::optional
<scoped_restore_current_pspace_and_thread
>
956 maybe_restore_thread
;
958 /* If we're handling a child exit, then inferior_ptid points
959 at the inferior's pid, not to a thread. */
961 maybe_restore_inferior
.emplace ();
963 maybe_restore_thread
.emplace ();
965 /* We're letting loose of the parent. */
966 tp
= any_live_thread_of_inferior (vfork_parent
);
967 switch_to_thread (tp
);
969 /* We're about to detach from the parent, which implicitly
970 removes breakpoints from its address space. There's a
971 catch here: we want to reuse the spaces for the child,
972 but, parent/child are still sharing the pspace at this
973 point, although the exec in reality makes the kernel give
974 the child a fresh set of new pages. The problem here is
975 that the breakpoints module being unaware of this, would
976 likely chose the child process to write to the parent
977 address space. Swapping the child temporarily away from
978 the spaces has the desired effect. Yes, this is "sort
981 pspace
= inf
->pspace
;
982 aspace
= inf
->aspace
;
986 if (print_inferior_events
)
989 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
991 target_terminal::ours_for_output ();
995 fprintf_filtered (gdb_stdlog
,
996 _("[Detaching vfork parent %s "
997 "after child exec]\n"), pidstr
.c_str ());
1001 fprintf_filtered (gdb_stdlog
,
1002 _("[Detaching vfork parent %s "
1003 "after child exit]\n"), pidstr
.c_str ());
1007 target_detach (vfork_parent
, 0);
1010 inf
->pspace
= pspace
;
1011 inf
->aspace
= aspace
;
1015 /* We're staying attached to the parent, so, really give the
1016 child a new address space. */
1017 inf
->pspace
= new program_space (maybe_new_address_space ());
1018 inf
->aspace
= inf
->pspace
->aspace
;
1020 set_current_program_space (inf
->pspace
);
1022 resume_parent
= vfork_parent
->pid
;
1026 /* If this is a vfork child exiting, then the pspace and
1027 aspaces were shared with the parent. Since we're
1028 reporting the process exit, we'll be mourning all that is
1029 found in the address space, and switching to null_ptid,
1030 preparing to start a new inferior. But, since we don't
1031 want to clobber the parent's address/program spaces, we
1032 go ahead and create a new one for this exiting
1035 /* Switch to null_ptid while running clone_program_space, so
1036 that clone_program_space doesn't want to read the
1037 selected frame of a dead process. */
1038 scoped_restore restore_ptid
1039 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1041 inf
->pspace
= new program_space (maybe_new_address_space ());
1042 inf
->aspace
= inf
->pspace
->aspace
;
1043 set_current_program_space (inf
->pspace
);
1045 inf
->symfile_flags
= SYMFILE_NO_READ
;
1046 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1048 resume_parent
= vfork_parent
->pid
;
1051 gdb_assert (current_program_space
== inf
->pspace
);
1053 if (non_stop
&& resume_parent
!= -1)
1055 /* If the user wanted the parent to be running, let it go
1057 scoped_restore_current_thread restore_thread
;
1060 fprintf_unfiltered (gdb_stdlog
,
1061 "infrun: resuming vfork parent process %d\n",
1064 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1069 /* Enum strings for "set|show follow-exec-mode". */
1071 static const char follow_exec_mode_new
[] = "new";
1072 static const char follow_exec_mode_same
[] = "same";
1073 static const char *const follow_exec_mode_names
[] =
1075 follow_exec_mode_new
,
1076 follow_exec_mode_same
,
1080 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1082 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1083 struct cmd_list_element
*c
, const char *value
)
1085 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1088 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1091 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1093 struct inferior
*inf
= current_inferior ();
1094 int pid
= ptid
.pid ();
1095 ptid_t process_ptid
;
1097 /* Switch terminal for any messages produced e.g. by
1098 breakpoint_re_set. */
1099 target_terminal::ours_for_output ();
1101 /* This is an exec event that we actually wish to pay attention to.
1102 Refresh our symbol table to the newly exec'd program, remove any
1103 momentary bp's, etc.
1105 If there are breakpoints, they aren't really inserted now,
1106 since the exec() transformed our inferior into a fresh set
1109 We want to preserve symbolic breakpoints on the list, since
1110 we have hopes that they can be reset after the new a.out's
1111 symbol table is read.
1113 However, any "raw" breakpoints must be removed from the list
1114 (e.g., the solib bp's), since their address is probably invalid
1117 And, we DON'T want to call delete_breakpoints() here, since
1118 that may write the bp's "shadow contents" (the instruction
1119 value that was overwritten with a TRAP instruction). Since
1120 we now have a new a.out, those shadow contents aren't valid. */
1122 mark_breakpoints_out ();
1124 /* The target reports the exec event to the main thread, even if
1125 some other thread does the exec, and even if the main thread was
1126 stopped or already gone. We may still have non-leader threads of
1127 the process on our list. E.g., on targets that don't have thread
1128 exit events (like remote); or on native Linux in non-stop mode if
1129 there were only two threads in the inferior and the non-leader
1130 one is the one that execs (and nothing forces an update of the
1131 thread list up to here). When debugging remotely, it's best to
1132 avoid extra traffic, when possible, so avoid syncing the thread
1133 list with the target, and instead go ahead and delete all threads
1134 of the process but one that reported the event. Note this must
1135 be done before calling update_breakpoints_after_exec, as
1136 otherwise clearing the threads' resources would reference stale
1137 thread breakpoints -- it may have been one of these threads that
1138 stepped across the exec. We could just clear their stepping
1139 states, but as long as we're iterating, might as well delete
1140 them. Deleting them now rather than at the next user-visible
1141 stop provides a nicer sequence of events for user and MI
1143 for (thread_info
*th
: all_threads_safe ())
1144 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1147 /* We also need to clear any left over stale state for the
1148 leader/event thread. E.g., if there was any step-resume
1149 breakpoint or similar, it's gone now. We cannot truly
1150 step-to-next statement through an exec(). */
1151 thread_info
*th
= inferior_thread ();
1152 th
->control
.step_resume_breakpoint
= NULL
;
1153 th
->control
.exception_resume_breakpoint
= NULL
;
1154 th
->control
.single_step_breakpoints
= NULL
;
1155 th
->control
.step_range_start
= 0;
1156 th
->control
.step_range_end
= 0;
1158 /* The user may have had the main thread held stopped in the
1159 previous image (e.g., schedlock on, or non-stop). Release
1161 th
->stop_requested
= 0;
1163 update_breakpoints_after_exec ();
1165 /* What is this a.out's name? */
1166 process_ptid
= ptid_t (pid
);
1167 printf_unfiltered (_("%s is executing new program: %s\n"),
1168 target_pid_to_str (process_ptid
).c_str (),
1171 /* We've followed the inferior through an exec. Therefore, the
1172 inferior has essentially been killed & reborn. */
1174 breakpoint_init_inferior (inf_execd
);
1176 gdb::unique_xmalloc_ptr
<char> exec_file_host
1177 = exec_file_find (exec_file_target
, NULL
);
1179 /* If we were unable to map the executable target pathname onto a host
1180 pathname, tell the user that. Otherwise GDB's subsequent behavior
1181 is confusing. Maybe it would even be better to stop at this point
1182 so that the user can specify a file manually before continuing. */
1183 if (exec_file_host
== NULL
)
1184 warning (_("Could not load symbols for executable %s.\n"
1185 "Do you need \"set sysroot\"?"),
1188 /* Reset the shared library package. This ensures that we get a
1189 shlib event when the child reaches "_start", at which point the
1190 dld will have had a chance to initialize the child. */
1191 /* Also, loading a symbol file below may trigger symbol lookups, and
1192 we don't want those to be satisfied by the libraries of the
1193 previous incarnation of this process. */
1194 no_shared_libraries (NULL
, 0);
1196 if (follow_exec_mode_string
== follow_exec_mode_new
)
1198 /* The user wants to keep the old inferior and program spaces
1199 around. Create a new fresh one, and switch to it. */
1201 /* Do exit processing for the original inferior before setting the new
1202 inferior's pid. Having two inferiors with the same pid would confuse
1203 find_inferior_p(t)id. Transfer the terminal state and info from the
1204 old to the new inferior. */
1205 inf
= add_inferior_with_spaces ();
1206 swap_terminal_info (inf
, current_inferior ());
1207 exit_inferior_silent (current_inferior ());
1210 target_follow_exec (inf
, exec_file_target
);
1212 inferior
*org_inferior
= current_inferior ();
1213 switch_to_inferior_no_thread (inf
);
1214 push_target (org_inferior
->process_target ());
1215 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1216 switch_to_thread (thr
);
1220 /* The old description may no longer be fit for the new image.
1221 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1222 old description; we'll read a new one below. No need to do
1223 this on "follow-exec-mode new", as the old inferior stays
1224 around (its description is later cleared/refetched on
1226 target_clear_description ();
1229 gdb_assert (current_program_space
== inf
->pspace
);
1231 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1232 because the proper displacement for a PIE (Position Independent
1233 Executable) main symbol file will only be computed by
1234 solib_create_inferior_hook below. breakpoint_re_set would fail
1235 to insert the breakpoints with the zero displacement. */
1236 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1238 /* If the target can specify a description, read it. Must do this
1239 after flipping to the new executable (because the target supplied
1240 description must be compatible with the executable's
1241 architecture, and the old executable may e.g., be 32-bit, while
1242 the new one 64-bit), and before anything involving memory or
1244 target_find_description ();
1246 solib_create_inferior_hook (0);
1248 jit_inferior_created_hook ();
1250 breakpoint_re_set ();
1252 /* Reinsert all breakpoints. (Those which were symbolic have
1253 been reset to the proper address in the new a.out, thanks
1254 to symbol_file_command...). */
1255 insert_breakpoints ();
1257 /* The next resume of this inferior should bring it to the shlib
1258 startup breakpoints. (If the user had also set bp's on
1259 "main" from the old (parent) process, then they'll auto-
1260 matically get reset there in the new process.). */
1263 /* The queue of threads that need to do a step-over operation to get
1264 past e.g., a breakpoint. What technique is used to step over the
1265 breakpoint/watchpoint does not matter -- all threads end up in the
1266 same queue, to maintain rough temporal order of execution, in order
1267 to avoid starvation, otherwise, we could e.g., find ourselves
1268 constantly stepping the same couple threads past their breakpoints
1269 over and over, if the single-step finish fast enough. */
1270 struct thread_info
*step_over_queue_head
;
1272 /* Bit flags indicating what the thread needs to step over. */
1274 enum step_over_what_flag
1276 /* Step over a breakpoint. */
1277 STEP_OVER_BREAKPOINT
= 1,
1279 /* Step past a non-continuable watchpoint, in order to let the
1280 instruction execute so we can evaluate the watchpoint
1282 STEP_OVER_WATCHPOINT
= 2
1284 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1286 /* Info about an instruction that is being stepped over. */
1288 struct step_over_info
1290 /* If we're stepping past a breakpoint, this is the address space
1291 and address of the instruction the breakpoint is set at. We'll
1292 skip inserting all breakpoints here. Valid iff ASPACE is
1294 const address_space
*aspace
;
1297 /* The instruction being stepped over triggers a nonsteppable
1298 watchpoint. If true, we'll skip inserting watchpoints. */
1299 int nonsteppable_watchpoint_p
;
1301 /* The thread's global number. */
1305 /* The step-over info of the location that is being stepped over.
1307 Note that with async/breakpoint always-inserted mode, a user might
1308 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1309 being stepped over. As setting a new breakpoint inserts all
1310 breakpoints, we need to make sure the breakpoint being stepped over
1311 isn't inserted then. We do that by only clearing the step-over
1312 info when the step-over is actually finished (or aborted).
1314 Presently GDB can only step over one breakpoint at any given time.
1315 Given threads that can't run code in the same address space as the
1316 breakpoint's can't really miss the breakpoint, GDB could be taught
1317 to step-over at most one breakpoint per address space (so this info
1318 could move to the address space object if/when GDB is extended).
1319 The set of breakpoints being stepped over will normally be much
1320 smaller than the set of all breakpoints, so a flag in the
1321 breakpoint location structure would be wasteful. A separate list
1322 also saves complexity and run-time, as otherwise we'd have to go
1323 through all breakpoint locations clearing their flag whenever we
1324 start a new sequence. Similar considerations weigh against storing
1325 this info in the thread object. Plus, not all step overs actually
1326 have breakpoint locations -- e.g., stepping past a single-step
1327 breakpoint, or stepping to complete a non-continuable
1329 static struct step_over_info step_over_info
;
1331 /* Record the address of the breakpoint/instruction we're currently
1333 N.B. We record the aspace and address now, instead of say just the thread,
1334 because when we need the info later the thread may be running. */
1337 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1338 int nonsteppable_watchpoint_p
,
1341 step_over_info
.aspace
= aspace
;
1342 step_over_info
.address
= address
;
1343 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1344 step_over_info
.thread
= thread
;
1347 /* Called when we're not longer stepping over a breakpoint / an
1348 instruction, so all breakpoints are free to be (re)inserted. */
1351 clear_step_over_info (void)
1354 fprintf_unfiltered (gdb_stdlog
,
1355 "infrun: clear_step_over_info\n");
1356 step_over_info
.aspace
= NULL
;
1357 step_over_info
.address
= 0;
1358 step_over_info
.nonsteppable_watchpoint_p
= 0;
1359 step_over_info
.thread
= -1;
1365 stepping_past_instruction_at (struct address_space
*aspace
,
1368 return (step_over_info
.aspace
!= NULL
1369 && breakpoint_address_match (aspace
, address
,
1370 step_over_info
.aspace
,
1371 step_over_info
.address
));
1377 thread_is_stepping_over_breakpoint (int thread
)
1379 return (step_over_info
.thread
!= -1
1380 && thread
== step_over_info
.thread
);
1386 stepping_past_nonsteppable_watchpoint (void)
1388 return step_over_info
.nonsteppable_watchpoint_p
;
1391 /* Returns true if step-over info is valid. */
1394 step_over_info_valid_p (void)
1396 return (step_over_info
.aspace
!= NULL
1397 || stepping_past_nonsteppable_watchpoint ());
1401 /* Displaced stepping. */
1403 /* In non-stop debugging mode, we must take special care to manage
1404 breakpoints properly; in particular, the traditional strategy for
1405 stepping a thread past a breakpoint it has hit is unsuitable.
1406 'Displaced stepping' is a tactic for stepping one thread past a
1407 breakpoint it has hit while ensuring that other threads running
1408 concurrently will hit the breakpoint as they should.
1410 The traditional way to step a thread T off a breakpoint in a
1411 multi-threaded program in all-stop mode is as follows:
1413 a0) Initially, all threads are stopped, and breakpoints are not
1415 a1) We single-step T, leaving breakpoints uninserted.
1416 a2) We insert breakpoints, and resume all threads.
1418 In non-stop debugging, however, this strategy is unsuitable: we
1419 don't want to have to stop all threads in the system in order to
1420 continue or step T past a breakpoint. Instead, we use displaced
1423 n0) Initially, T is stopped, other threads are running, and
1424 breakpoints are inserted.
1425 n1) We copy the instruction "under" the breakpoint to a separate
1426 location, outside the main code stream, making any adjustments
1427 to the instruction, register, and memory state as directed by
1429 n2) We single-step T over the instruction at its new location.
1430 n3) We adjust the resulting register and memory state as directed
1431 by T's architecture. This includes resetting T's PC to point
1432 back into the main instruction stream.
1435 This approach depends on the following gdbarch methods:
1437 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1438 indicate where to copy the instruction, and how much space must
1439 be reserved there. We use these in step n1.
1441 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1442 address, and makes any necessary adjustments to the instruction,
1443 register contents, and memory. We use this in step n1.
1445 - gdbarch_displaced_step_fixup adjusts registers and memory after
1446 we have successfully single-stepped the instruction, to yield the
1447 same effect the instruction would have had if we had executed it
1448 at its original address. We use this in step n3.
1450 The gdbarch_displaced_step_copy_insn and
1451 gdbarch_displaced_step_fixup functions must be written so that
1452 copying an instruction with gdbarch_displaced_step_copy_insn,
1453 single-stepping across the copied instruction, and then applying
1454 gdbarch_displaced_insn_fixup should have the same effects on the
1455 thread's memory and registers as stepping the instruction in place
1456 would have. Exactly which responsibilities fall to the copy and
1457 which fall to the fixup is up to the author of those functions.
1459 See the comments in gdbarch.sh for details.
1461 Note that displaced stepping and software single-step cannot
1462 currently be used in combination, although with some care I think
1463 they could be made to. Software single-step works by placing
1464 breakpoints on all possible subsequent instructions; if the
1465 displaced instruction is a PC-relative jump, those breakpoints
1466 could fall in very strange places --- on pages that aren't
1467 executable, or at addresses that are not proper instruction
1468 boundaries. (We do generally let other threads run while we wait
1469 to hit the software single-step breakpoint, and they might
1470 encounter such a corrupted instruction.) One way to work around
1471 this would be to have gdbarch_displaced_step_copy_insn fully
1472 simulate the effect of PC-relative instructions (and return NULL)
1473 on architectures that use software single-stepping.
1475 In non-stop mode, we can have independent and simultaneous step
1476 requests, so more than one thread may need to simultaneously step
1477 over a breakpoint. The current implementation assumes there is
1478 only one scratch space per process. In this case, we have to
1479 serialize access to the scratch space. If thread A wants to step
1480 over a breakpoint, but we are currently waiting for some other
1481 thread to complete a displaced step, we leave thread A stopped and
1482 place it in the displaced_step_request_queue. Whenever a displaced
1483 step finishes, we pick the next thread in the queue and start a new
1484 displaced step operation on it. See displaced_step_prepare and
1485 displaced_step_fixup for details. */
1487 /* Default destructor for displaced_step_closure. */
1489 displaced_step_closure::~displaced_step_closure () = default;
1491 /* Get the displaced stepping state of process PID. */
1493 static displaced_step_inferior_state
*
1494 get_displaced_stepping_state (inferior
*inf
)
1496 return &inf
->displaced_step_state
;
1499 /* Returns true if any inferior has a thread doing a displaced
1503 displaced_step_in_progress_any_inferior ()
1505 for (inferior
*i
: all_inferiors ())
1507 if (i
->displaced_step_state
.step_thread
!= nullptr)
1514 /* Return true if thread represented by PTID is doing a displaced
1518 displaced_step_in_progress_thread (thread_info
*thread
)
1520 gdb_assert (thread
!= NULL
);
1522 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1525 /* Return true if process PID has a thread doing a displaced step. */
1528 displaced_step_in_progress (inferior
*inf
)
1530 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1533 /* If inferior is in displaced stepping, and ADDR equals to starting address
1534 of copy area, return corresponding displaced_step_closure. Otherwise,
1537 struct displaced_step_closure
*
1538 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1540 displaced_step_inferior_state
*displaced
1541 = get_displaced_stepping_state (current_inferior ());
1543 /* If checking the mode of displaced instruction in copy area. */
1544 if (displaced
->step_thread
!= nullptr
1545 && displaced
->step_copy
== addr
)
1546 return displaced
->step_closure
.get ();
1552 infrun_inferior_exit (struct inferior
*inf
)
1554 inf
->displaced_step_state
.reset ();
1557 /* If ON, and the architecture supports it, GDB will use displaced
1558 stepping to step over breakpoints. If OFF, or if the architecture
1559 doesn't support it, GDB will instead use the traditional
1560 hold-and-step approach. If AUTO (which is the default), GDB will
1561 decide which technique to use to step over breakpoints depending on
1562 whether the target works in a non-stop way (see use_displaced_stepping). */
1564 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1567 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1568 struct cmd_list_element
*c
,
1571 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1572 fprintf_filtered (file
,
1573 _("Debugger's willingness to use displaced stepping "
1574 "to step over breakpoints is %s (currently %s).\n"),
1575 value
, target_is_non_stop_p () ? "on" : "off");
1577 fprintf_filtered (file
,
1578 _("Debugger's willingness to use displaced stepping "
1579 "to step over breakpoints is %s.\n"), value
);
1582 /* Return true if the gdbarch implements the required methods to use
1583 displaced stepping. */
1586 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1588 /* Only check for the presence of step_copy_insn. Other required methods
1589 are checked by the gdbarch validation. */
1590 return gdbarch_displaced_step_copy_insn_p (arch
);
1593 /* Return non-zero if displaced stepping can/should be used to step
1594 over breakpoints of thread TP. */
1597 use_displaced_stepping (thread_info
*tp
)
1599 /* If the user disabled it explicitly, don't use displaced stepping. */
1600 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1603 /* If "auto", only use displaced stepping if the target operates in a non-stop
1605 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1606 && !target_is_non_stop_p ())
1609 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1611 /* If the architecture doesn't implement displaced stepping, don't use
1613 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1616 /* If recording, don't use displaced stepping. */
1617 if (find_record_target () != nullptr)
1620 displaced_step_inferior_state
*displaced_state
1621 = get_displaced_stepping_state (tp
->inf
);
1623 /* If displaced stepping failed before for this inferior, don't bother trying
1625 if (displaced_state
->failed_before
)
1631 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1634 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1636 displaced
->reset ();
1639 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1640 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1642 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1644 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1646 displaced_step_dump_bytes (struct ui_file
*file
,
1647 const gdb_byte
*buf
,
1652 for (i
= 0; i
< len
; i
++)
1653 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1654 fputs_unfiltered ("\n", file
);
1657 /* Prepare to single-step, using displaced stepping.
1659 Note that we cannot use displaced stepping when we have a signal to
1660 deliver. If we have a signal to deliver and an instruction to step
1661 over, then after the step, there will be no indication from the
1662 target whether the thread entered a signal handler or ignored the
1663 signal and stepped over the instruction successfully --- both cases
1664 result in a simple SIGTRAP. In the first case we mustn't do a
1665 fixup, and in the second case we must --- but we can't tell which.
1666 Comments in the code for 'random signals' in handle_inferior_event
1667 explain how we handle this case instead.
1669 Returns 1 if preparing was successful -- this thread is going to be
1670 stepped now; 0 if displaced stepping this thread got queued; or -1
1671 if this instruction can't be displaced stepped. */
1674 displaced_step_prepare_throw (thread_info
*tp
)
1676 regcache
*regcache
= get_thread_regcache (tp
);
1677 struct gdbarch
*gdbarch
= regcache
->arch ();
1678 const address_space
*aspace
= regcache
->aspace ();
1679 CORE_ADDR original
, copy
;
1683 /* We should never reach this function if the architecture does not
1684 support displaced stepping. */
1685 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1687 /* Nor if the thread isn't meant to step over a breakpoint. */
1688 gdb_assert (tp
->control
.trap_expected
);
1690 /* Disable range stepping while executing in the scratch pad. We
1691 want a single-step even if executing the displaced instruction in
1692 the scratch buffer lands within the stepping range (e.g., a
1694 tp
->control
.may_range_step
= 0;
1696 /* We have to displaced step one thread at a time, as we only have
1697 access to a single scratch space per inferior. */
1699 displaced_step_inferior_state
*displaced
1700 = get_displaced_stepping_state (tp
->inf
);
1702 if (displaced
->step_thread
!= nullptr)
1704 /* Already waiting for a displaced step to finish. Defer this
1705 request and place in queue. */
1707 if (debug_displaced
)
1708 fprintf_unfiltered (gdb_stdlog
,
1709 "displaced: deferring step of %s\n",
1710 target_pid_to_str (tp
->ptid
).c_str ());
1712 thread_step_over_chain_enqueue (tp
);
1717 if (debug_displaced
)
1718 fprintf_unfiltered (gdb_stdlog
,
1719 "displaced: stepping %s now\n",
1720 target_pid_to_str (tp
->ptid
).c_str ());
1723 displaced_step_reset (displaced
);
1725 scoped_restore_current_thread restore_thread
;
1727 switch_to_thread (tp
);
1729 original
= regcache_read_pc (regcache
);
1731 copy
= gdbarch_displaced_step_location (gdbarch
);
1732 len
= gdbarch_max_insn_length (gdbarch
);
1734 if (breakpoint_in_range_p (aspace
, copy
, len
))
1736 /* There's a breakpoint set in the scratch pad location range
1737 (which is usually around the entry point). We'd either
1738 install it before resuming, which would overwrite/corrupt the
1739 scratch pad, or if it was already inserted, this displaced
1740 step would overwrite it. The latter is OK in the sense that
1741 we already assume that no thread is going to execute the code
1742 in the scratch pad range (after initial startup) anyway, but
1743 the former is unacceptable. Simply punt and fallback to
1744 stepping over this breakpoint in-line. */
1745 if (debug_displaced
)
1747 fprintf_unfiltered (gdb_stdlog
,
1748 "displaced: breakpoint set in scratch pad. "
1749 "Stepping over breakpoint in-line instead.\n");
1755 /* Save the original contents of the copy area. */
1756 displaced
->step_saved_copy
.resize (len
);
1757 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1759 throw_error (MEMORY_ERROR
,
1760 _("Error accessing memory address %s (%s) for "
1761 "displaced-stepping scratch space."),
1762 paddress (gdbarch
, copy
), safe_strerror (status
));
1763 if (debug_displaced
)
1765 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1766 paddress (gdbarch
, copy
));
1767 displaced_step_dump_bytes (gdb_stdlog
,
1768 displaced
->step_saved_copy
.data (),
1772 displaced
->step_closure
1773 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1774 if (displaced
->step_closure
== NULL
)
1776 /* The architecture doesn't know how or want to displaced step
1777 this instruction or instruction sequence. Fallback to
1778 stepping over the breakpoint in-line. */
1782 /* Save the information we need to fix things up if the step
1784 displaced
->step_thread
= tp
;
1785 displaced
->step_gdbarch
= gdbarch
;
1786 displaced
->step_original
= original
;
1787 displaced
->step_copy
= copy
;
1790 displaced_step_reset_cleanup
cleanup (displaced
);
1792 /* Resume execution at the copy. */
1793 regcache_write_pc (regcache
, copy
);
1798 if (debug_displaced
)
1799 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1800 paddress (gdbarch
, copy
));
1805 /* Wrapper for displaced_step_prepare_throw that disabled further
1806 attempts at displaced stepping if we get a memory error. */
1809 displaced_step_prepare (thread_info
*thread
)
1815 prepared
= displaced_step_prepare_throw (thread
);
1817 catch (const gdb_exception_error
&ex
)
1819 struct displaced_step_inferior_state
*displaced_state
;
1821 if (ex
.error
!= MEMORY_ERROR
1822 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1827 fprintf_unfiltered (gdb_stdlog
,
1828 "infrun: disabling displaced stepping: %s\n",
1832 /* Be verbose if "set displaced-stepping" is "on", silent if
1834 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1836 warning (_("disabling displaced stepping: %s"),
1840 /* Disable further displaced stepping attempts. */
1842 = get_displaced_stepping_state (thread
->inf
);
1843 displaced_state
->failed_before
= 1;
1850 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1851 const gdb_byte
*myaddr
, int len
)
1853 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1855 inferior_ptid
= ptid
;
1856 write_memory (memaddr
, myaddr
, len
);
1859 /* Restore the contents of the copy area for thread PTID. */
1862 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1865 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1867 write_memory_ptid (ptid
, displaced
->step_copy
,
1868 displaced
->step_saved_copy
.data (), len
);
1869 if (debug_displaced
)
1870 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1871 target_pid_to_str (ptid
).c_str (),
1872 paddress (displaced
->step_gdbarch
,
1873 displaced
->step_copy
));
1876 /* If we displaced stepped an instruction successfully, adjust
1877 registers and memory to yield the same effect the instruction would
1878 have had if we had executed it at its original address, and return
1879 1. If the instruction didn't complete, relocate the PC and return
1880 -1. If the thread wasn't displaced stepping, return 0. */
1883 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1885 struct displaced_step_inferior_state
*displaced
1886 = get_displaced_stepping_state (event_thread
->inf
);
1889 /* Was this event for the thread we displaced? */
1890 if (displaced
->step_thread
!= event_thread
)
1893 /* Fixup may need to read memory/registers. Switch to the thread
1894 that we're fixing up. Also, target_stopped_by_watchpoint checks
1895 the current thread, and displaced_step_restore performs ptid-dependent
1896 memory accesses using current_inferior() and current_top_target(). */
1897 switch_to_thread (event_thread
);
1899 displaced_step_reset_cleanup
cleanup (displaced
);
1901 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1903 /* Did the instruction complete successfully? */
1904 if (signal
== GDB_SIGNAL_TRAP
1905 && !(target_stopped_by_watchpoint ()
1906 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1907 || target_have_steppable_watchpoint
)))
1909 /* Fix up the resulting state. */
1910 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1911 displaced
->step_closure
.get (),
1912 displaced
->step_original
,
1913 displaced
->step_copy
,
1914 get_thread_regcache (displaced
->step_thread
));
1919 /* Since the instruction didn't complete, all we can do is
1921 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1922 CORE_ADDR pc
= regcache_read_pc (regcache
);
1924 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1925 regcache_write_pc (regcache
, pc
);
1932 /* Data to be passed around while handling an event. This data is
1933 discarded between events. */
1934 struct execution_control_state
1936 process_stratum_target
*target
;
1938 /* The thread that got the event, if this was a thread event; NULL
1940 struct thread_info
*event_thread
;
1942 struct target_waitstatus ws
;
1943 int stop_func_filled_in
;
1944 CORE_ADDR stop_func_start
;
1945 CORE_ADDR stop_func_end
;
1946 const char *stop_func_name
;
1949 /* True if the event thread hit the single-step breakpoint of
1950 another thread. Thus the event doesn't cause a stop, the thread
1951 needs to be single-stepped past the single-step breakpoint before
1952 we can switch back to the original stepping thread. */
1953 int hit_singlestep_breakpoint
;
1956 /* Clear ECS and set it to point at TP. */
1959 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1961 memset (ecs
, 0, sizeof (*ecs
));
1962 ecs
->event_thread
= tp
;
1963 ecs
->ptid
= tp
->ptid
;
1966 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1967 static void prepare_to_wait (struct execution_control_state
*ecs
);
1968 static int keep_going_stepped_thread (struct thread_info
*tp
);
1969 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1971 /* Are there any pending step-over requests? If so, run all we can
1972 now and return true. Otherwise, return false. */
1975 start_step_over (void)
1977 struct thread_info
*tp
, *next
;
1979 /* Don't start a new step-over if we already have an in-line
1980 step-over operation ongoing. */
1981 if (step_over_info_valid_p ())
1984 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1986 struct execution_control_state ecss
;
1987 struct execution_control_state
*ecs
= &ecss
;
1988 step_over_what step_what
;
1989 int must_be_in_line
;
1991 gdb_assert (!tp
->stop_requested
);
1993 next
= thread_step_over_chain_next (tp
);
1995 /* If this inferior already has a displaced step in process,
1996 don't start a new one. */
1997 if (displaced_step_in_progress (tp
->inf
))
2000 step_what
= thread_still_needs_step_over (tp
);
2001 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
2002 || ((step_what
& STEP_OVER_BREAKPOINT
)
2003 && !use_displaced_stepping (tp
)));
2005 /* We currently stop all threads of all processes to step-over
2006 in-line. If we need to start a new in-line step-over, let
2007 any pending displaced steps finish first. */
2008 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
2011 thread_step_over_chain_remove (tp
);
2013 if (step_over_queue_head
== NULL
)
2016 fprintf_unfiltered (gdb_stdlog
,
2017 "infrun: step-over queue now empty\n");
2020 if (tp
->control
.trap_expected
2024 internal_error (__FILE__
, __LINE__
,
2025 "[%s] has inconsistent state: "
2026 "trap_expected=%d, resumed=%d, executing=%d\n",
2027 target_pid_to_str (tp
->ptid
).c_str (),
2028 tp
->control
.trap_expected
,
2034 fprintf_unfiltered (gdb_stdlog
,
2035 "infrun: resuming [%s] for step-over\n",
2036 target_pid_to_str (tp
->ptid
).c_str ());
2038 /* keep_going_pass_signal skips the step-over if the breakpoint
2039 is no longer inserted. In all-stop, we want to keep looking
2040 for a thread that needs a step-over instead of resuming TP,
2041 because we wouldn't be able to resume anything else until the
2042 target stops again. In non-stop, the resume always resumes
2043 only TP, so it's OK to let the thread resume freely. */
2044 if (!target_is_non_stop_p () && !step_what
)
2047 switch_to_thread (tp
);
2048 reset_ecs (ecs
, tp
);
2049 keep_going_pass_signal (ecs
);
2051 if (!ecs
->wait_some_more
)
2052 error (_("Command aborted."));
2054 gdb_assert (tp
->resumed
);
2056 /* If we started a new in-line step-over, we're done. */
2057 if (step_over_info_valid_p ())
2059 gdb_assert (tp
->control
.trap_expected
);
2063 if (!target_is_non_stop_p ())
2065 /* On all-stop, shouldn't have resumed unless we needed a
2067 gdb_assert (tp
->control
.trap_expected
2068 || tp
->step_after_step_resume_breakpoint
);
2070 /* With remote targets (at least), in all-stop, we can't
2071 issue any further remote commands until the program stops
2076 /* Either the thread no longer needed a step-over, or a new
2077 displaced stepping sequence started. Even in the latter
2078 case, continue looking. Maybe we can also start another
2079 displaced step on a thread of other process. */
2085 /* Update global variables holding ptids to hold NEW_PTID if they were
2086 holding OLD_PTID. */
2088 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2090 if (inferior_ptid
== old_ptid
)
2091 inferior_ptid
= new_ptid
;
2096 static const char schedlock_off
[] = "off";
2097 static const char schedlock_on
[] = "on";
2098 static const char schedlock_step
[] = "step";
2099 static const char schedlock_replay
[] = "replay";
2100 static const char *const scheduler_enums
[] = {
2107 static const char *scheduler_mode
= schedlock_replay
;
2109 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2110 struct cmd_list_element
*c
, const char *value
)
2112 fprintf_filtered (file
,
2113 _("Mode for locking scheduler "
2114 "during execution is \"%s\".\n"),
2119 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2121 if (!target_can_lock_scheduler
)
2123 scheduler_mode
= schedlock_off
;
2124 error (_("Target '%s' cannot support this command."), target_shortname
);
2128 /* True if execution commands resume all threads of all processes by
2129 default; otherwise, resume only threads of the current inferior
2131 bool sched_multi
= false;
2133 /* Try to setup for software single stepping over the specified location.
2134 Return 1 if target_resume() should use hardware single step.
2136 GDBARCH the current gdbarch.
2137 PC the location to step over. */
2140 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2144 if (execution_direction
== EXEC_FORWARD
2145 && gdbarch_software_single_step_p (gdbarch
))
2146 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2154 user_visible_resume_ptid (int step
)
2160 /* With non-stop mode on, threads are always handled
2162 resume_ptid
= inferior_ptid
;
2164 else if ((scheduler_mode
== schedlock_on
)
2165 || (scheduler_mode
== schedlock_step
&& step
))
2167 /* User-settable 'scheduler' mode requires solo thread
2169 resume_ptid
= inferior_ptid
;
2171 else if ((scheduler_mode
== schedlock_replay
)
2172 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2174 /* User-settable 'scheduler' mode requires solo thread resume in replay
2176 resume_ptid
= inferior_ptid
;
2178 else if (!sched_multi
&& target_supports_multi_process ())
2180 /* Resume all threads of the current process (and none of other
2182 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2186 /* Resume all threads of all processes. */
2187 resume_ptid
= RESUME_ALL
;
2195 process_stratum_target
*
2196 user_visible_resume_target (ptid_t resume_ptid
)
2198 return (resume_ptid
== minus_one_ptid
&& sched_multi
2200 : current_inferior ()->process_target ());
2203 /* Return a ptid representing the set of threads that we will resume,
2204 in the perspective of the target, assuming run control handling
2205 does not require leaving some threads stopped (e.g., stepping past
2206 breakpoint). USER_STEP indicates whether we're about to start the
2207 target for a stepping command. */
2210 internal_resume_ptid (int user_step
)
2212 /* In non-stop, we always control threads individually. Note that
2213 the target may always work in non-stop mode even with "set
2214 non-stop off", in which case user_visible_resume_ptid could
2215 return a wildcard ptid. */
2216 if (target_is_non_stop_p ())
2217 return inferior_ptid
;
2219 return user_visible_resume_ptid (user_step
);
2222 /* Wrapper for target_resume, that handles infrun-specific
2226 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2228 struct thread_info
*tp
= inferior_thread ();
2230 gdb_assert (!tp
->stop_requested
);
2232 /* Install inferior's terminal modes. */
2233 target_terminal::inferior ();
2235 /* Avoid confusing the next resume, if the next stop/resume
2236 happens to apply to another thread. */
2237 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2239 /* Advise target which signals may be handled silently.
2241 If we have removed breakpoints because we are stepping over one
2242 in-line (in any thread), we need to receive all signals to avoid
2243 accidentally skipping a breakpoint during execution of a signal
2246 Likewise if we're displaced stepping, otherwise a trap for a
2247 breakpoint in a signal handler might be confused with the
2248 displaced step finishing. We don't make the displaced_step_fixup
2249 step distinguish the cases instead, because:
2251 - a backtrace while stopped in the signal handler would show the
2252 scratch pad as frame older than the signal handler, instead of
2253 the real mainline code.
2255 - when the thread is later resumed, the signal handler would
2256 return to the scratch pad area, which would no longer be
2258 if (step_over_info_valid_p ()
2259 || displaced_step_in_progress (tp
->inf
))
2260 target_pass_signals ({});
2262 target_pass_signals (signal_pass
);
2264 target_resume (resume_ptid
, step
, sig
);
2266 target_commit_resume ();
2268 if (target_can_async_p ())
2272 /* Resume the inferior. SIG is the signal to give the inferior
2273 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2274 call 'resume', which handles exceptions. */
2277 resume_1 (enum gdb_signal sig
)
2279 struct regcache
*regcache
= get_current_regcache ();
2280 struct gdbarch
*gdbarch
= regcache
->arch ();
2281 struct thread_info
*tp
= inferior_thread ();
2282 const address_space
*aspace
= regcache
->aspace ();
2284 /* This represents the user's step vs continue request. When
2285 deciding whether "set scheduler-locking step" applies, it's the
2286 user's intention that counts. */
2287 const int user_step
= tp
->control
.stepping_command
;
2288 /* This represents what we'll actually request the target to do.
2289 This can decay from a step to a continue, if e.g., we need to
2290 implement single-stepping with breakpoints (software
2294 gdb_assert (!tp
->stop_requested
);
2295 gdb_assert (!thread_is_in_step_over_chain (tp
));
2297 if (tp
->suspend
.waitstatus_pending_p
)
2302 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2304 fprintf_unfiltered (gdb_stdlog
,
2305 "infrun: resume: thread %s has pending wait "
2306 "status %s (currently_stepping=%d).\n",
2307 target_pid_to_str (tp
->ptid
).c_str (),
2309 currently_stepping (tp
));
2312 tp
->inf
->process_target ()->threads_executing
= true;
2315 /* FIXME: What should we do if we are supposed to resume this
2316 thread with a signal? Maybe we should maintain a queue of
2317 pending signals to deliver. */
2318 if (sig
!= GDB_SIGNAL_0
)
2320 warning (_("Couldn't deliver signal %s to %s."),
2321 gdb_signal_to_name (sig
),
2322 target_pid_to_str (tp
->ptid
).c_str ());
2325 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2327 if (target_can_async_p ())
2330 /* Tell the event loop we have an event to process. */
2331 mark_async_event_handler (infrun_async_inferior_event_token
);
2336 tp
->stepped_breakpoint
= 0;
2338 /* Depends on stepped_breakpoint. */
2339 step
= currently_stepping (tp
);
2341 if (current_inferior ()->waiting_for_vfork_done
)
2343 /* Don't try to single-step a vfork parent that is waiting for
2344 the child to get out of the shared memory region (by exec'ing
2345 or exiting). This is particularly important on software
2346 single-step archs, as the child process would trip on the
2347 software single step breakpoint inserted for the parent
2348 process. Since the parent will not actually execute any
2349 instruction until the child is out of the shared region (such
2350 are vfork's semantics), it is safe to simply continue it.
2351 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2352 the parent, and tell it to `keep_going', which automatically
2353 re-sets it stepping. */
2355 fprintf_unfiltered (gdb_stdlog
,
2356 "infrun: resume : clear step\n");
2360 CORE_ADDR pc
= regcache_read_pc (regcache
);
2363 fprintf_unfiltered (gdb_stdlog
,
2364 "infrun: resume (step=%d, signal=%s), "
2365 "trap_expected=%d, current thread [%s] at %s\n",
2366 step
, gdb_signal_to_symbol_string (sig
),
2367 tp
->control
.trap_expected
,
2368 target_pid_to_str (inferior_ptid
).c_str (),
2369 paddress (gdbarch
, pc
));
2371 /* Normally, by the time we reach `resume', the breakpoints are either
2372 removed or inserted, as appropriate. The exception is if we're sitting
2373 at a permanent breakpoint; we need to step over it, but permanent
2374 breakpoints can't be removed. So we have to test for it here. */
2375 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2377 if (sig
!= GDB_SIGNAL_0
)
2379 /* We have a signal to pass to the inferior. The resume
2380 may, or may not take us to the signal handler. If this
2381 is a step, we'll need to stop in the signal handler, if
2382 there's one, (if the target supports stepping into
2383 handlers), or in the next mainline instruction, if
2384 there's no handler. If this is a continue, we need to be
2385 sure to run the handler with all breakpoints inserted.
2386 In all cases, set a breakpoint at the current address
2387 (where the handler returns to), and once that breakpoint
2388 is hit, resume skipping the permanent breakpoint. If
2389 that breakpoint isn't hit, then we've stepped into the
2390 signal handler (or hit some other event). We'll delete
2391 the step-resume breakpoint then. */
2394 fprintf_unfiltered (gdb_stdlog
,
2395 "infrun: resume: skipping permanent breakpoint, "
2396 "deliver signal first\n");
2398 clear_step_over_info ();
2399 tp
->control
.trap_expected
= 0;
2401 if (tp
->control
.step_resume_breakpoint
== NULL
)
2403 /* Set a "high-priority" step-resume, as we don't want
2404 user breakpoints at PC to trigger (again) when this
2406 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2407 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2409 tp
->step_after_step_resume_breakpoint
= step
;
2412 insert_breakpoints ();
2416 /* There's no signal to pass, we can go ahead and skip the
2417 permanent breakpoint manually. */
2419 fprintf_unfiltered (gdb_stdlog
,
2420 "infrun: resume: skipping permanent breakpoint\n");
2421 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2422 /* Update pc to reflect the new address from which we will
2423 execute instructions. */
2424 pc
= regcache_read_pc (regcache
);
2428 /* We've already advanced the PC, so the stepping part
2429 is done. Now we need to arrange for a trap to be
2430 reported to handle_inferior_event. Set a breakpoint
2431 at the current PC, and run to it. Don't update
2432 prev_pc, because if we end in
2433 switch_back_to_stepped_thread, we want the "expected
2434 thread advanced also" branch to be taken. IOW, we
2435 don't want this thread to step further from PC
2437 gdb_assert (!step_over_info_valid_p ());
2438 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2439 insert_breakpoints ();
2441 resume_ptid
= internal_resume_ptid (user_step
);
2442 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2449 /* If we have a breakpoint to step over, make sure to do a single
2450 step only. Same if we have software watchpoints. */
2451 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2452 tp
->control
.may_range_step
= 0;
2454 /* If displaced stepping is enabled, step over breakpoints by executing a
2455 copy of the instruction at a different address.
2457 We can't use displaced stepping when we have a signal to deliver;
2458 the comments for displaced_step_prepare explain why. The
2459 comments in the handle_inferior event for dealing with 'random
2460 signals' explain what we do instead.
2462 We can't use displaced stepping when we are waiting for vfork_done
2463 event, displaced stepping breaks the vfork child similarly as single
2464 step software breakpoint. */
2465 if (tp
->control
.trap_expected
2466 && use_displaced_stepping (tp
)
2467 && !step_over_info_valid_p ()
2468 && sig
== GDB_SIGNAL_0
2469 && !current_inferior ()->waiting_for_vfork_done
)
2471 int prepared
= displaced_step_prepare (tp
);
2476 fprintf_unfiltered (gdb_stdlog
,
2477 "Got placed in step-over queue\n");
2479 tp
->control
.trap_expected
= 0;
2482 else if (prepared
< 0)
2484 /* Fallback to stepping over the breakpoint in-line. */
2486 if (target_is_non_stop_p ())
2487 stop_all_threads ();
2489 set_step_over_info (regcache
->aspace (),
2490 regcache_read_pc (regcache
), 0, tp
->global_num
);
2492 step
= maybe_software_singlestep (gdbarch
, pc
);
2494 insert_breakpoints ();
2496 else if (prepared
> 0)
2498 struct displaced_step_inferior_state
*displaced
;
2500 /* Update pc to reflect the new address from which we will
2501 execute instructions due to displaced stepping. */
2502 pc
= regcache_read_pc (get_thread_regcache (tp
));
2504 displaced
= get_displaced_stepping_state (tp
->inf
);
2505 step
= gdbarch_displaced_step_hw_singlestep
2506 (gdbarch
, displaced
->step_closure
.get ());
2510 /* Do we need to do it the hard way, w/temp breakpoints? */
2512 step
= maybe_software_singlestep (gdbarch
, pc
);
2514 /* Currently, our software single-step implementation leads to different
2515 results than hardware single-stepping in one situation: when stepping
2516 into delivering a signal which has an associated signal handler,
2517 hardware single-step will stop at the first instruction of the handler,
2518 while software single-step will simply skip execution of the handler.
2520 For now, this difference in behavior is accepted since there is no
2521 easy way to actually implement single-stepping into a signal handler
2522 without kernel support.
2524 However, there is one scenario where this difference leads to follow-on
2525 problems: if we're stepping off a breakpoint by removing all breakpoints
2526 and then single-stepping. In this case, the software single-step
2527 behavior means that even if there is a *breakpoint* in the signal
2528 handler, GDB still would not stop.
2530 Fortunately, we can at least fix this particular issue. We detect
2531 here the case where we are about to deliver a signal while software
2532 single-stepping with breakpoints removed. In this situation, we
2533 revert the decisions to remove all breakpoints and insert single-
2534 step breakpoints, and instead we install a step-resume breakpoint
2535 at the current address, deliver the signal without stepping, and
2536 once we arrive back at the step-resume breakpoint, actually step
2537 over the breakpoint we originally wanted to step over. */
2538 if (thread_has_single_step_breakpoints_set (tp
)
2539 && sig
!= GDB_SIGNAL_0
2540 && step_over_info_valid_p ())
2542 /* If we have nested signals or a pending signal is delivered
2543 immediately after a handler returns, might already have
2544 a step-resume breakpoint set on the earlier handler. We cannot
2545 set another step-resume breakpoint; just continue on until the
2546 original breakpoint is hit. */
2547 if (tp
->control
.step_resume_breakpoint
== NULL
)
2549 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2550 tp
->step_after_step_resume_breakpoint
= 1;
2553 delete_single_step_breakpoints (tp
);
2555 clear_step_over_info ();
2556 tp
->control
.trap_expected
= 0;
2558 insert_breakpoints ();
2561 /* If STEP is set, it's a request to use hardware stepping
2562 facilities. But in that case, we should never
2563 use singlestep breakpoint. */
2564 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2566 /* Decide the set of threads to ask the target to resume. */
2567 if (tp
->control
.trap_expected
)
2569 /* We're allowing a thread to run past a breakpoint it has
2570 hit, either by single-stepping the thread with the breakpoint
2571 removed, or by displaced stepping, with the breakpoint inserted.
2572 In the former case, we need to single-step only this thread,
2573 and keep others stopped, as they can miss this breakpoint if
2574 allowed to run. That's not really a problem for displaced
2575 stepping, but, we still keep other threads stopped, in case
2576 another thread is also stopped for a breakpoint waiting for
2577 its turn in the displaced stepping queue. */
2578 resume_ptid
= inferior_ptid
;
2581 resume_ptid
= internal_resume_ptid (user_step
);
2583 if (execution_direction
!= EXEC_REVERSE
2584 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2586 /* There are two cases where we currently need to step a
2587 breakpoint instruction when we have a signal to deliver:
2589 - See handle_signal_stop where we handle random signals that
2590 could take out us out of the stepping range. Normally, in
2591 that case we end up continuing (instead of stepping) over the
2592 signal handler with a breakpoint at PC, but there are cases
2593 where we should _always_ single-step, even if we have a
2594 step-resume breakpoint, like when a software watchpoint is
2595 set. Assuming single-stepping and delivering a signal at the
2596 same time would takes us to the signal handler, then we could
2597 have removed the breakpoint at PC to step over it. However,
2598 some hardware step targets (like e.g., Mac OS) can't step
2599 into signal handlers, and for those, we need to leave the
2600 breakpoint at PC inserted, as otherwise if the handler
2601 recurses and executes PC again, it'll miss the breakpoint.
2602 So we leave the breakpoint inserted anyway, but we need to
2603 record that we tried to step a breakpoint instruction, so
2604 that adjust_pc_after_break doesn't end up confused.
2606 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2607 in one thread after another thread that was stepping had been
2608 momentarily paused for a step-over. When we re-resume the
2609 stepping thread, it may be resumed from that address with a
2610 breakpoint that hasn't trapped yet. Seen with
2611 gdb.threads/non-stop-fair-events.exp, on targets that don't
2612 do displaced stepping. */
2615 fprintf_unfiltered (gdb_stdlog
,
2616 "infrun: resume: [%s] stepped breakpoint\n",
2617 target_pid_to_str (tp
->ptid
).c_str ());
2619 tp
->stepped_breakpoint
= 1;
2621 /* Most targets can step a breakpoint instruction, thus
2622 executing it normally. But if this one cannot, just
2623 continue and we will hit it anyway. */
2624 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2629 && tp
->control
.trap_expected
2630 && use_displaced_stepping (tp
)
2631 && !step_over_info_valid_p ())
2633 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2634 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2635 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2638 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2639 paddress (resume_gdbarch
, actual_pc
));
2640 read_memory (actual_pc
, buf
, sizeof (buf
));
2641 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2644 if (tp
->control
.may_range_step
)
2646 /* If we're resuming a thread with the PC out of the step
2647 range, then we're doing some nested/finer run control
2648 operation, like stepping the thread out of the dynamic
2649 linker or the displaced stepping scratch pad. We
2650 shouldn't have allowed a range step then. */
2651 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2654 do_target_resume (resume_ptid
, step
, sig
);
2658 /* Resume the inferior. SIG is the signal to give the inferior
2659 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2660 rolls back state on error. */
2663 resume (gdb_signal sig
)
2669 catch (const gdb_exception
&ex
)
2671 /* If resuming is being aborted for any reason, delete any
2672 single-step breakpoint resume_1 may have created, to avoid
2673 confusing the following resumption, and to avoid leaving
2674 single-step breakpoints perturbing other threads, in case
2675 we're running in non-stop mode. */
2676 if (inferior_ptid
!= null_ptid
)
2677 delete_single_step_breakpoints (inferior_thread ());
2687 /* Counter that tracks number of user visible stops. This can be used
2688 to tell whether a command has proceeded the inferior past the
2689 current location. This allows e.g., inferior function calls in
2690 breakpoint commands to not interrupt the command list. When the
2691 call finishes successfully, the inferior is standing at the same
2692 breakpoint as if nothing happened (and so we don't call
2694 static ULONGEST current_stop_id
;
2701 return current_stop_id
;
2704 /* Called when we report a user visible stop. */
2712 /* Clear out all variables saying what to do when inferior is continued.
2713 First do this, then set the ones you want, then call `proceed'. */
2716 clear_proceed_status_thread (struct thread_info
*tp
)
2719 fprintf_unfiltered (gdb_stdlog
,
2720 "infrun: clear_proceed_status_thread (%s)\n",
2721 target_pid_to_str (tp
->ptid
).c_str ());
2723 /* If we're starting a new sequence, then the previous finished
2724 single-step is no longer relevant. */
2725 if (tp
->suspend
.waitstatus_pending_p
)
2727 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2730 fprintf_unfiltered (gdb_stdlog
,
2731 "infrun: clear_proceed_status: pending "
2732 "event of %s was a finished step. "
2734 target_pid_to_str (tp
->ptid
).c_str ());
2736 tp
->suspend
.waitstatus_pending_p
= 0;
2737 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2739 else if (debug_infrun
)
2742 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2744 fprintf_unfiltered (gdb_stdlog
,
2745 "infrun: clear_proceed_status_thread: thread %s "
2746 "has pending wait status %s "
2747 "(currently_stepping=%d).\n",
2748 target_pid_to_str (tp
->ptid
).c_str (),
2750 currently_stepping (tp
));
2754 /* If this signal should not be seen by program, give it zero.
2755 Used for debugging signals. */
2756 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2757 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2759 delete tp
->thread_fsm
;
2760 tp
->thread_fsm
= NULL
;
2762 tp
->control
.trap_expected
= 0;
2763 tp
->control
.step_range_start
= 0;
2764 tp
->control
.step_range_end
= 0;
2765 tp
->control
.may_range_step
= 0;
2766 tp
->control
.step_frame_id
= null_frame_id
;
2767 tp
->control
.step_stack_frame_id
= null_frame_id
;
2768 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2769 tp
->control
.step_start_function
= NULL
;
2770 tp
->stop_requested
= 0;
2772 tp
->control
.stop_step
= 0;
2774 tp
->control
.proceed_to_finish
= 0;
2776 tp
->control
.stepping_command
= 0;
2778 /* Discard any remaining commands or status from previous stop. */
2779 bpstat_clear (&tp
->control
.stop_bpstat
);
2783 clear_proceed_status (int step
)
2785 /* With scheduler-locking replay, stop replaying other threads if we're
2786 not replaying the user-visible resume ptid.
2788 This is a convenience feature to not require the user to explicitly
2789 stop replaying the other threads. We're assuming that the user's
2790 intent is to resume tracing the recorded process. */
2791 if (!non_stop
&& scheduler_mode
== schedlock_replay
2792 && target_record_is_replaying (minus_one_ptid
)
2793 && !target_record_will_replay (user_visible_resume_ptid (step
),
2794 execution_direction
))
2795 target_record_stop_replaying ();
2797 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2799 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2800 process_stratum_target
*resume_target
2801 = user_visible_resume_target (resume_ptid
);
2803 /* In all-stop mode, delete the per-thread status of all threads
2804 we're about to resume, implicitly and explicitly. */
2805 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2806 clear_proceed_status_thread (tp
);
2809 if (inferior_ptid
!= null_ptid
)
2811 struct inferior
*inferior
;
2815 /* If in non-stop mode, only delete the per-thread status of
2816 the current thread. */
2817 clear_proceed_status_thread (inferior_thread ());
2820 inferior
= current_inferior ();
2821 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2824 gdb::observers::about_to_proceed
.notify ();
2827 /* Returns true if TP is still stopped at a breakpoint that needs
2828 stepping-over in order to make progress. If the breakpoint is gone
2829 meanwhile, we can skip the whole step-over dance. */
2832 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2834 if (tp
->stepping_over_breakpoint
)
2836 struct regcache
*regcache
= get_thread_regcache (tp
);
2838 if (breakpoint_here_p (regcache
->aspace (),
2839 regcache_read_pc (regcache
))
2840 == ordinary_breakpoint_here
)
2843 tp
->stepping_over_breakpoint
= 0;
2849 /* Check whether thread TP still needs to start a step-over in order
2850 to make progress when resumed. Returns an bitwise or of enum
2851 step_over_what bits, indicating what needs to be stepped over. */
2853 static step_over_what
2854 thread_still_needs_step_over (struct thread_info
*tp
)
2856 step_over_what what
= 0;
2858 if (thread_still_needs_step_over_bp (tp
))
2859 what
|= STEP_OVER_BREAKPOINT
;
2861 if (tp
->stepping_over_watchpoint
2862 && !target_have_steppable_watchpoint
)
2863 what
|= STEP_OVER_WATCHPOINT
;
2868 /* Returns true if scheduler locking applies. STEP indicates whether
2869 we're about to do a step/next-like command to a thread. */
2872 schedlock_applies (struct thread_info
*tp
)
2874 return (scheduler_mode
== schedlock_on
2875 || (scheduler_mode
== schedlock_step
2876 && tp
->control
.stepping_command
)
2877 || (scheduler_mode
== schedlock_replay
2878 && target_record_will_replay (minus_one_ptid
,
2879 execution_direction
)));
2882 /* Calls target_commit_resume on all targets. */
2885 commit_resume_all_targets ()
2887 scoped_restore_current_thread restore_thread
;
2889 /* Map between process_target and a representative inferior. This
2890 is to avoid committing a resume in the same target more than
2891 once. Resumptions must be idempotent, so this is an
2893 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2895 for (inferior
*inf
: all_non_exited_inferiors ())
2896 if (inf
->has_execution ())
2897 conn_inf
[inf
->process_target ()] = inf
;
2899 for (const auto &ci
: conn_inf
)
2901 inferior
*inf
= ci
.second
;
2902 switch_to_inferior_no_thread (inf
);
2903 target_commit_resume ();
2907 /* Check that all the targets we're about to resume are in non-stop
2908 mode. Ideally, we'd only care whether all targets support
2909 target-async, but we're not there yet. E.g., stop_all_threads
2910 doesn't know how to handle all-stop targets. Also, the remote
2911 protocol in all-stop mode is synchronous, irrespective of
2912 target-async, which means that things like a breakpoint re-set
2913 triggered by one target would try to read memory from all targets
2917 check_multi_target_resumption (process_stratum_target
*resume_target
)
2919 if (!non_stop
&& resume_target
== nullptr)
2921 scoped_restore_current_thread restore_thread
;
2923 /* This is used to track whether we're resuming more than one
2925 process_stratum_target
*first_connection
= nullptr;
2927 /* The first inferior we see with a target that does not work in
2928 always-non-stop mode. */
2929 inferior
*first_not_non_stop
= nullptr;
2931 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2933 switch_to_inferior_no_thread (inf
);
2935 if (!target_has_execution
)
2938 process_stratum_target
*proc_target
2939 = current_inferior ()->process_target();
2941 if (!target_is_non_stop_p ())
2942 first_not_non_stop
= inf
;
2944 if (first_connection
== nullptr)
2945 first_connection
= proc_target
;
2946 else if (first_connection
!= proc_target
2947 && first_not_non_stop
!= nullptr)
2949 switch_to_inferior_no_thread (first_not_non_stop
);
2951 proc_target
= current_inferior ()->process_target();
2953 error (_("Connection %d (%s) does not support "
2954 "multi-target resumption."),
2955 proc_target
->connection_number
,
2956 make_target_connection_string (proc_target
).c_str ());
2962 /* Basic routine for continuing the program in various fashions.
2964 ADDR is the address to resume at, or -1 for resume where stopped.
2965 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2966 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2968 You should call clear_proceed_status before calling proceed. */
2971 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2973 struct regcache
*regcache
;
2974 struct gdbarch
*gdbarch
;
2976 struct execution_control_state ecss
;
2977 struct execution_control_state
*ecs
= &ecss
;
2980 /* If we're stopped at a fork/vfork, follow the branch set by the
2981 "set follow-fork-mode" command; otherwise, we'll just proceed
2982 resuming the current thread. */
2983 if (!follow_fork ())
2985 /* The target for some reason decided not to resume. */
2987 if (target_can_async_p ())
2988 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2992 /* We'll update this if & when we switch to a new thread. */
2993 previous_inferior_ptid
= inferior_ptid
;
2995 regcache
= get_current_regcache ();
2996 gdbarch
= regcache
->arch ();
2997 const address_space
*aspace
= regcache
->aspace ();
2999 pc
= regcache_read_pc_protected (regcache
);
3001 thread_info
*cur_thr
= inferior_thread ();
3003 /* Fill in with reasonable starting values. */
3004 init_thread_stepping_state (cur_thr
);
3006 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
3009 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
3010 process_stratum_target
*resume_target
3011 = user_visible_resume_target (resume_ptid
);
3013 check_multi_target_resumption (resume_target
);
3015 if (addr
== (CORE_ADDR
) -1)
3017 if (pc
== cur_thr
->suspend
.stop_pc
3018 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3019 && execution_direction
!= EXEC_REVERSE
)
3020 /* There is a breakpoint at the address we will resume at,
3021 step one instruction before inserting breakpoints so that
3022 we do not stop right away (and report a second hit at this
3025 Note, we don't do this in reverse, because we won't
3026 actually be executing the breakpoint insn anyway.
3027 We'll be (un-)executing the previous instruction. */
3028 cur_thr
->stepping_over_breakpoint
= 1;
3029 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3030 && gdbarch_single_step_through_delay (gdbarch
,
3031 get_current_frame ()))
3032 /* We stepped onto an instruction that needs to be stepped
3033 again before re-inserting the breakpoint, do so. */
3034 cur_thr
->stepping_over_breakpoint
= 1;
3038 regcache_write_pc (regcache
, addr
);
3041 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3042 cur_thr
->suspend
.stop_signal
= siggnal
;
3044 /* If an exception is thrown from this point on, make sure to
3045 propagate GDB's knowledge of the executing state to the
3046 frontend/user running state. */
3047 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3049 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3050 threads (e.g., we might need to set threads stepping over
3051 breakpoints first), from the user/frontend's point of view, all
3052 threads in RESUME_PTID are now running. Unless we're calling an
3053 inferior function, as in that case we pretend the inferior
3054 doesn't run at all. */
3055 if (!cur_thr
->control
.in_infcall
)
3056 set_running (resume_target
, resume_ptid
, true);
3059 fprintf_unfiltered (gdb_stdlog
,
3060 "infrun: proceed (addr=%s, signal=%s)\n",
3061 paddress (gdbarch
, addr
),
3062 gdb_signal_to_symbol_string (siggnal
));
3064 annotate_starting ();
3066 /* Make sure that output from GDB appears before output from the
3068 gdb_flush (gdb_stdout
);
3070 /* Since we've marked the inferior running, give it the terminal. A
3071 QUIT/Ctrl-C from here on is forwarded to the target (which can
3072 still detect attempts to unblock a stuck connection with repeated
3073 Ctrl-C from within target_pass_ctrlc). */
3074 target_terminal::inferior ();
3076 /* In a multi-threaded task we may select another thread and
3077 then continue or step.
3079 But if a thread that we're resuming had stopped at a breakpoint,
3080 it will immediately cause another breakpoint stop without any
3081 execution (i.e. it will report a breakpoint hit incorrectly). So
3082 we must step over it first.
3084 Look for threads other than the current (TP) that reported a
3085 breakpoint hit and haven't been resumed yet since. */
3087 /* If scheduler locking applies, we can avoid iterating over all
3089 if (!non_stop
&& !schedlock_applies (cur_thr
))
3091 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3094 switch_to_thread_no_regs (tp
);
3096 /* Ignore the current thread here. It's handled
3101 if (!thread_still_needs_step_over (tp
))
3104 gdb_assert (!thread_is_in_step_over_chain (tp
));
3107 fprintf_unfiltered (gdb_stdlog
,
3108 "infrun: need to step-over [%s] first\n",
3109 target_pid_to_str (tp
->ptid
).c_str ());
3111 thread_step_over_chain_enqueue (tp
);
3114 switch_to_thread (cur_thr
);
3117 /* Enqueue the current thread last, so that we move all other
3118 threads over their breakpoints first. */
3119 if (cur_thr
->stepping_over_breakpoint
)
3120 thread_step_over_chain_enqueue (cur_thr
);
3122 /* If the thread isn't started, we'll still need to set its prev_pc,
3123 so that switch_back_to_stepped_thread knows the thread hasn't
3124 advanced. Must do this before resuming any thread, as in
3125 all-stop/remote, once we resume we can't send any other packet
3126 until the target stops again. */
3127 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3130 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3132 started
= start_step_over ();
3134 if (step_over_info_valid_p ())
3136 /* Either this thread started a new in-line step over, or some
3137 other thread was already doing one. In either case, don't
3138 resume anything else until the step-over is finished. */
3140 else if (started
&& !target_is_non_stop_p ())
3142 /* A new displaced stepping sequence was started. In all-stop,
3143 we can't talk to the target anymore until it next stops. */
3145 else if (!non_stop
&& target_is_non_stop_p ())
3147 /* In all-stop, but the target is always in non-stop mode.
3148 Start all other threads that are implicitly resumed too. */
3149 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3152 switch_to_thread_no_regs (tp
);
3154 if (!tp
->inf
->has_execution ())
3157 fprintf_unfiltered (gdb_stdlog
,
3158 "infrun: proceed: [%s] target has "
3160 target_pid_to_str (tp
->ptid
).c_str ());
3167 fprintf_unfiltered (gdb_stdlog
,
3168 "infrun: proceed: [%s] resumed\n",
3169 target_pid_to_str (tp
->ptid
).c_str ());
3170 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3174 if (thread_is_in_step_over_chain (tp
))
3177 fprintf_unfiltered (gdb_stdlog
,
3178 "infrun: proceed: [%s] needs step-over\n",
3179 target_pid_to_str (tp
->ptid
).c_str ());
3184 fprintf_unfiltered (gdb_stdlog
,
3185 "infrun: proceed: resuming %s\n",
3186 target_pid_to_str (tp
->ptid
).c_str ());
3188 reset_ecs (ecs
, tp
);
3189 switch_to_thread (tp
);
3190 keep_going_pass_signal (ecs
);
3191 if (!ecs
->wait_some_more
)
3192 error (_("Command aborted."));
3195 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3197 /* The thread wasn't started, and isn't queued, run it now. */
3198 reset_ecs (ecs
, cur_thr
);
3199 switch_to_thread (cur_thr
);
3200 keep_going_pass_signal (ecs
);
3201 if (!ecs
->wait_some_more
)
3202 error (_("Command aborted."));
3206 commit_resume_all_targets ();
3208 finish_state
.release ();
3210 /* If we've switched threads above, switch back to the previously
3211 current thread. We don't want the user to see a different
3213 switch_to_thread (cur_thr
);
3215 /* Tell the event loop to wait for it to stop. If the target
3216 supports asynchronous execution, it'll do this from within
3218 if (!target_can_async_p ())
3219 mark_async_event_handler (infrun_async_inferior_event_token
);
3223 /* Start remote-debugging of a machine over a serial link. */
3226 start_remote (int from_tty
)
3228 inferior
*inf
= current_inferior ();
3229 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3231 /* Always go on waiting for the target, regardless of the mode. */
3232 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3233 indicate to wait_for_inferior that a target should timeout if
3234 nothing is returned (instead of just blocking). Because of this,
3235 targets expecting an immediate response need to, internally, set
3236 things up so that the target_wait() is forced to eventually
3238 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3239 differentiate to its caller what the state of the target is after
3240 the initial open has been performed. Here we're assuming that
3241 the target has stopped. It should be possible to eventually have
3242 target_open() return to the caller an indication that the target
3243 is currently running and GDB state should be set to the same as
3244 for an async run. */
3245 wait_for_inferior (inf
);
3247 /* Now that the inferior has stopped, do any bookkeeping like
3248 loading shared libraries. We want to do this before normal_stop,
3249 so that the displayed frame is up to date. */
3250 post_create_inferior (current_top_target (), from_tty
);
3255 /* Initialize static vars when a new inferior begins. */
3258 init_wait_for_inferior (void)
3260 /* These are meaningless until the first time through wait_for_inferior. */
3262 breakpoint_init_inferior (inf_starting
);
3264 clear_proceed_status (0);
3266 nullify_last_target_wait_ptid ();
3268 previous_inferior_ptid
= inferior_ptid
;
3273 static void handle_inferior_event (struct execution_control_state
*ecs
);
3275 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3276 struct execution_control_state
*ecs
);
3277 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3278 struct execution_control_state
*ecs
);
3279 static void handle_signal_stop (struct execution_control_state
*ecs
);
3280 static void check_exception_resume (struct execution_control_state
*,
3281 struct frame_info
*);
3283 static void end_stepping_range (struct execution_control_state
*ecs
);
3284 static void stop_waiting (struct execution_control_state
*ecs
);
3285 static void keep_going (struct execution_control_state
*ecs
);
3286 static void process_event_stop_test (struct execution_control_state
*ecs
);
3287 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3289 /* This function is attached as a "thread_stop_requested" observer.
3290 Cleanup local state that assumed the PTID was to be resumed, and
3291 report the stop to the frontend. */
3294 infrun_thread_stop_requested (ptid_t ptid
)
3296 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3298 /* PTID was requested to stop. If the thread was already stopped,
3299 but the user/frontend doesn't know about that yet (e.g., the
3300 thread had been temporarily paused for some step-over), set up
3301 for reporting the stop now. */
3302 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3304 if (tp
->state
!= THREAD_RUNNING
)
3309 /* Remove matching threads from the step-over queue, so
3310 start_step_over doesn't try to resume them
3312 if (thread_is_in_step_over_chain (tp
))
3313 thread_step_over_chain_remove (tp
);
3315 /* If the thread is stopped, but the user/frontend doesn't
3316 know about that yet, queue a pending event, as if the
3317 thread had just stopped now. Unless the thread already had
3319 if (!tp
->suspend
.waitstatus_pending_p
)
3321 tp
->suspend
.waitstatus_pending_p
= 1;
3322 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3323 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3326 /* Clear the inline-frame state, since we're re-processing the
3328 clear_inline_frame_state (tp
);
3330 /* If this thread was paused because some other thread was
3331 doing an inline-step over, let that finish first. Once
3332 that happens, we'll restart all threads and consume pending
3333 stop events then. */
3334 if (step_over_info_valid_p ())
3337 /* Otherwise we can process the (new) pending event now. Set
3338 it so this pending event is considered by
3345 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3347 if (target_last_proc_target
== tp
->inf
->process_target ()
3348 && target_last_wait_ptid
== tp
->ptid
)
3349 nullify_last_target_wait_ptid ();
3352 /* Delete the step resume, single-step and longjmp/exception resume
3353 breakpoints of TP. */
3356 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3358 delete_step_resume_breakpoint (tp
);
3359 delete_exception_resume_breakpoint (tp
);
3360 delete_single_step_breakpoints (tp
);
3363 /* If the target still has execution, call FUNC for each thread that
3364 just stopped. In all-stop, that's all the non-exited threads; in
3365 non-stop, that's the current thread, only. */
3367 typedef void (*for_each_just_stopped_thread_callback_func
)
3368 (struct thread_info
*tp
);
3371 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3373 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3376 if (target_is_non_stop_p ())
3378 /* If in non-stop mode, only the current thread stopped. */
3379 func (inferior_thread ());
3383 /* In all-stop mode, all threads have stopped. */
3384 for (thread_info
*tp
: all_non_exited_threads ())
3389 /* Delete the step resume and longjmp/exception resume breakpoints of
3390 the threads that just stopped. */
3393 delete_just_stopped_threads_infrun_breakpoints (void)
3395 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3398 /* Delete the single-step breakpoints of the threads that just
3402 delete_just_stopped_threads_single_step_breakpoints (void)
3404 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3410 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3411 const struct target_waitstatus
*ws
)
3413 std::string status_string
= target_waitstatus_to_string (ws
);
3416 /* The text is split over several lines because it was getting too long.
3417 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3418 output as a unit; we want only one timestamp printed if debug_timestamp
3421 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3424 waiton_ptid
.tid ());
3425 if (waiton_ptid
.pid () != -1)
3426 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3427 stb
.printf (", status) =\n");
3428 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3432 target_pid_to_str (result_ptid
).c_str ());
3433 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3435 /* This uses %s in part to handle %'s in the text, but also to avoid
3436 a gcc error: the format attribute requires a string literal. */
3437 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3440 /* Select a thread at random, out of those which are resumed and have
3443 static struct thread_info
*
3444 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3448 auto has_event
= [&] (thread_info
*tp
)
3450 return (tp
->ptid
.matches (waiton_ptid
)
3452 && tp
->suspend
.waitstatus_pending_p
);
3455 /* First see how many events we have. Count only resumed threads
3456 that have an event pending. */
3457 for (thread_info
*tp
: inf
->non_exited_threads ())
3461 if (num_events
== 0)
3464 /* Now randomly pick a thread out of those that have had events. */
3465 int random_selector
= (int) ((num_events
* (double) rand ())
3466 / (RAND_MAX
+ 1.0));
3468 if (debug_infrun
&& num_events
> 1)
3469 fprintf_unfiltered (gdb_stdlog
,
3470 "infrun: Found %d events, selecting #%d\n",
3471 num_events
, random_selector
);
3473 /* Select the Nth thread that has had an event. */
3474 for (thread_info
*tp
: inf
->non_exited_threads ())
3476 if (random_selector
-- == 0)
3479 gdb_assert_not_reached ("event thread not found");
3482 /* Wrapper for target_wait that first checks whether threads have
3483 pending statuses to report before actually asking the target for
3484 more events. INF is the inferior we're using to call target_wait
3488 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3489 target_waitstatus
*status
, int options
)
3492 struct thread_info
*tp
;
3494 /* We know that we are looking for an event in the target of inferior
3495 INF, but we don't know which thread the event might come from. As
3496 such we want to make sure that INFERIOR_PTID is reset so that none of
3497 the wait code relies on it - doing so is always a mistake. */
3498 switch_to_inferior_no_thread (inf
);
3500 /* First check if there is a resumed thread with a wait status
3502 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3504 tp
= random_pending_event_thread (inf
, ptid
);
3509 fprintf_unfiltered (gdb_stdlog
,
3510 "infrun: Waiting for specific thread %s.\n",
3511 target_pid_to_str (ptid
).c_str ());
3513 /* We have a specific thread to check. */
3514 tp
= find_thread_ptid (inf
, ptid
);
3515 gdb_assert (tp
!= NULL
);
3516 if (!tp
->suspend
.waitstatus_pending_p
)
3521 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3522 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3524 struct regcache
*regcache
= get_thread_regcache (tp
);
3525 struct gdbarch
*gdbarch
= regcache
->arch ();
3529 pc
= regcache_read_pc (regcache
);
3531 if (pc
!= tp
->suspend
.stop_pc
)
3534 fprintf_unfiltered (gdb_stdlog
,
3535 "infrun: PC of %s changed. was=%s, now=%s\n",
3536 target_pid_to_str (tp
->ptid
).c_str (),
3537 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3538 paddress (gdbarch
, pc
));
3541 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3544 fprintf_unfiltered (gdb_stdlog
,
3545 "infrun: previous breakpoint of %s, at %s gone\n",
3546 target_pid_to_str (tp
->ptid
).c_str (),
3547 paddress (gdbarch
, pc
));
3555 fprintf_unfiltered (gdb_stdlog
,
3556 "infrun: pending event of %s cancelled.\n",
3557 target_pid_to_str (tp
->ptid
).c_str ());
3559 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3560 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3569 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3571 fprintf_unfiltered (gdb_stdlog
,
3572 "infrun: Using pending wait status %s for %s.\n",
3574 target_pid_to_str (tp
->ptid
).c_str ());
3577 /* Now that we've selected our final event LWP, un-adjust its PC
3578 if it was a software breakpoint (and the target doesn't
3579 always adjust the PC itself). */
3580 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3581 && !target_supports_stopped_by_sw_breakpoint ())
3583 struct regcache
*regcache
;
3584 struct gdbarch
*gdbarch
;
3587 regcache
= get_thread_regcache (tp
);
3588 gdbarch
= regcache
->arch ();
3590 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3595 pc
= regcache_read_pc (regcache
);
3596 regcache_write_pc (regcache
, pc
+ decr_pc
);
3600 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3601 *status
= tp
->suspend
.waitstatus
;
3602 tp
->suspend
.waitstatus_pending_p
= 0;
3604 /* Wake up the event loop again, until all pending events are
3606 if (target_is_async_p ())
3607 mark_async_event_handler (infrun_async_inferior_event_token
);
3611 /* But if we don't find one, we'll have to wait. */
3613 if (deprecated_target_wait_hook
)
3614 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3616 event_ptid
= target_wait (ptid
, status
, options
);
3621 /* Returns true if INF has any resumed thread with a status
3625 threads_are_resumed_pending_p (inferior
*inf
)
3627 for (thread_info
*tp
: inf
->non_exited_threads ())
3629 && tp
->suspend
.waitstatus_pending_p
)
3635 /* Wrapper for target_wait that first checks whether threads have
3636 pending statuses to report before actually asking the target for
3637 more events. Polls for events from all inferiors/targets. */
3640 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3642 int num_inferiors
= 0;
3643 int random_selector
;
3645 /* For fairness, we pick the first inferior/target to poll at
3646 random, and then continue polling the rest of the inferior list
3647 starting from that one in a circular fashion until the whole list
3650 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3652 return (inf
->process_target () != NULL
3653 && (threads_are_executing (inf
->process_target ())
3654 || threads_are_resumed_pending_p (inf
))
3655 && ptid_t (inf
->pid
).matches (wait_ptid
));
3658 /* First see how many resumed inferiors we have. */
3659 for (inferior
*inf
: all_inferiors ())
3660 if (inferior_matches (inf
))
3663 if (num_inferiors
== 0)
3665 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3669 /* Now randomly pick an inferior out of those that were resumed. */
3670 random_selector
= (int)
3671 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3673 if (debug_infrun
&& num_inferiors
> 1)
3674 fprintf_unfiltered (gdb_stdlog
,
3675 "infrun: Found %d inferiors, starting at #%d\n",
3676 num_inferiors
, random_selector
);
3678 /* Select the Nth inferior that was resumed. */
3680 inferior
*selected
= nullptr;
3682 for (inferior
*inf
: all_inferiors ())
3683 if (inferior_matches (inf
))
3684 if (random_selector
-- == 0)
3690 /* Now poll for events out of each of the resumed inferior's
3691 targets, starting from the selected one. */
3693 auto do_wait
= [&] (inferior
*inf
)
3695 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3696 ecs
->target
= inf
->process_target ();
3697 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3700 /* Needed in all-stop+target-non-stop mode, because we end up here
3701 spuriously after the target is all stopped and we've already
3702 reported the stop to the user, polling for events. */
3703 scoped_restore_current_thread restore_thread
;
3705 int inf_num
= selected
->num
;
3706 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3707 if (inferior_matches (inf
))
3711 for (inferior
*inf
= inferior_list
;
3712 inf
!= NULL
&& inf
->num
< inf_num
;
3714 if (inferior_matches (inf
))
3718 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3722 /* Prepare and stabilize the inferior for detaching it. E.g.,
3723 detaching while a thread is displaced stepping is a recipe for
3724 crashing it, as nothing would readjust the PC out of the scratch
3728 prepare_for_detach (void)
3730 struct inferior
*inf
= current_inferior ();
3731 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3733 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3735 /* Is any thread of this process displaced stepping? If not,
3736 there's nothing else to do. */
3737 if (displaced
->step_thread
== nullptr)
3741 fprintf_unfiltered (gdb_stdlog
,
3742 "displaced-stepping in-process while detaching");
3744 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3746 while (displaced
->step_thread
!= nullptr)
3748 struct execution_control_state ecss
;
3749 struct execution_control_state
*ecs
;
3752 memset (ecs
, 0, sizeof (*ecs
));
3754 overlay_cache_invalid
= 1;
3755 /* Flush target cache before starting to handle each event.
3756 Target was running and cache could be stale. This is just a
3757 heuristic. Running threads may modify target memory, but we
3758 don't get any event. */
3759 target_dcache_invalidate ();
3761 do_target_wait (pid_ptid
, ecs
, 0);
3764 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3766 /* If an error happens while handling the event, propagate GDB's
3767 knowledge of the executing state to the frontend/user running
3769 scoped_finish_thread_state
finish_state (inf
->process_target (),
3772 /* Now figure out what to do with the result of the result. */
3773 handle_inferior_event (ecs
);
3775 /* No error, don't finish the state yet. */
3776 finish_state
.release ();
3778 /* Breakpoints and watchpoints are not installed on the target
3779 at this point, and signals are passed directly to the
3780 inferior, so this must mean the process is gone. */
3781 if (!ecs
->wait_some_more
)
3783 restore_detaching
.release ();
3784 error (_("Program exited while detaching"));
3788 restore_detaching
.release ();
3791 /* Wait for control to return from inferior to debugger.
3793 If inferior gets a signal, we may decide to start it up again
3794 instead of returning. That is why there is a loop in this function.
3795 When this function actually returns it means the inferior
3796 should be left stopped and GDB should read more commands. */
3799 wait_for_inferior (inferior
*inf
)
3803 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3805 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3807 /* If an error happens while handling the event, propagate GDB's
3808 knowledge of the executing state to the frontend/user running
3810 scoped_finish_thread_state finish_state
3811 (inf
->process_target (), minus_one_ptid
);
3815 struct execution_control_state ecss
;
3816 struct execution_control_state
*ecs
= &ecss
;
3818 memset (ecs
, 0, sizeof (*ecs
));
3820 overlay_cache_invalid
= 1;
3822 /* Flush target cache before starting to handle each event.
3823 Target was running and cache could be stale. This is just a
3824 heuristic. Running threads may modify target memory, but we
3825 don't get any event. */
3826 target_dcache_invalidate ();
3828 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3829 ecs
->target
= inf
->process_target ();
3832 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3834 /* Now figure out what to do with the result of the result. */
3835 handle_inferior_event (ecs
);
3837 if (!ecs
->wait_some_more
)
3841 /* No error, don't finish the state yet. */
3842 finish_state
.release ();
3845 /* Cleanup that reinstalls the readline callback handler, if the
3846 target is running in the background. If while handling the target
3847 event something triggered a secondary prompt, like e.g., a
3848 pagination prompt, we'll have removed the callback handler (see
3849 gdb_readline_wrapper_line). Need to do this as we go back to the
3850 event loop, ready to process further input. Note this has no
3851 effect if the handler hasn't actually been removed, because calling
3852 rl_callback_handler_install resets the line buffer, thus losing
3856 reinstall_readline_callback_handler_cleanup ()
3858 struct ui
*ui
= current_ui
;
3862 /* We're not going back to the top level event loop yet. Don't
3863 install the readline callback, as it'd prep the terminal,
3864 readline-style (raw, noecho) (e.g., --batch). We'll install
3865 it the next time the prompt is displayed, when we're ready
3870 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3871 gdb_rl_callback_handler_reinstall ();
3874 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3875 that's just the event thread. In all-stop, that's all threads. */
3878 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3880 if (ecs
->event_thread
!= NULL
3881 && ecs
->event_thread
->thread_fsm
!= NULL
)
3882 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3886 for (thread_info
*thr
: all_non_exited_threads ())
3888 if (thr
->thread_fsm
== NULL
)
3890 if (thr
== ecs
->event_thread
)
3893 switch_to_thread (thr
);
3894 thr
->thread_fsm
->clean_up (thr
);
3897 if (ecs
->event_thread
!= NULL
)
3898 switch_to_thread (ecs
->event_thread
);
3902 /* Helper for all_uis_check_sync_execution_done that works on the
3906 check_curr_ui_sync_execution_done (void)
3908 struct ui
*ui
= current_ui
;
3910 if (ui
->prompt_state
== PROMPT_NEEDED
3912 && !gdb_in_secondary_prompt_p (ui
))
3914 target_terminal::ours ();
3915 gdb::observers::sync_execution_done
.notify ();
3916 ui_register_input_event_handler (ui
);
3923 all_uis_check_sync_execution_done (void)
3925 SWITCH_THRU_ALL_UIS ()
3927 check_curr_ui_sync_execution_done ();
3934 all_uis_on_sync_execution_starting (void)
3936 SWITCH_THRU_ALL_UIS ()
3938 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3939 async_disable_stdin ();
3943 /* Asynchronous version of wait_for_inferior. It is called by the
3944 event loop whenever a change of state is detected on the file
3945 descriptor corresponding to the target. It can be called more than
3946 once to complete a single execution command. In such cases we need
3947 to keep the state in a global variable ECSS. If it is the last time
3948 that this function is called for a single execution command, then
3949 report to the user that the inferior has stopped, and do the
3950 necessary cleanups. */
3953 fetch_inferior_event (void *client_data
)
3955 struct execution_control_state ecss
;
3956 struct execution_control_state
*ecs
= &ecss
;
3959 memset (ecs
, 0, sizeof (*ecs
));
3961 /* Events are always processed with the main UI as current UI. This
3962 way, warnings, debug output, etc. are always consistently sent to
3963 the main console. */
3964 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3966 /* End up with readline processing input, if necessary. */
3968 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3970 /* We're handling a live event, so make sure we're doing live
3971 debugging. If we're looking at traceframes while the target is
3972 running, we're going to need to get back to that mode after
3973 handling the event. */
3974 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3977 maybe_restore_traceframe
.emplace ();
3978 set_current_traceframe (-1);
3981 /* The user/frontend should not notice a thread switch due to
3982 internal events. Make sure we revert to the user selected
3983 thread and frame after handling the event and running any
3984 breakpoint commands. */
3985 scoped_restore_current_thread restore_thread
;
3987 overlay_cache_invalid
= 1;
3988 /* Flush target cache before starting to handle each event. Target
3989 was running and cache could be stale. This is just a heuristic.
3990 Running threads may modify target memory, but we don't get any
3992 target_dcache_invalidate ();
3994 scoped_restore save_exec_dir
3995 = make_scoped_restore (&execution_direction
,
3996 target_execution_direction ());
3998 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
4001 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
4003 /* Switch to the target that generated the event, so we can do
4004 target calls. Any inferior bound to the target will do, so we
4005 just switch to the first we find. */
4006 for (inferior
*inf
: all_inferiors (ecs
->target
))
4008 switch_to_inferior_no_thread (inf
);
4013 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
4015 /* If an error happens while handling the event, propagate GDB's
4016 knowledge of the executing state to the frontend/user running
4018 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
4019 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
4021 /* Get executed before scoped_restore_current_thread above to apply
4022 still for the thread which has thrown the exception. */
4023 auto defer_bpstat_clear
4024 = make_scope_exit (bpstat_clear_actions
);
4025 auto defer_delete_threads
4026 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4028 /* Now figure out what to do with the result of the result. */
4029 handle_inferior_event (ecs
);
4031 if (!ecs
->wait_some_more
)
4033 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4034 int should_stop
= 1;
4035 struct thread_info
*thr
= ecs
->event_thread
;
4037 delete_just_stopped_threads_infrun_breakpoints ();
4041 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4043 if (thread_fsm
!= NULL
)
4044 should_stop
= thread_fsm
->should_stop (thr
);
4053 bool should_notify_stop
= true;
4056 clean_up_just_stopped_threads_fsms (ecs
);
4058 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4059 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4061 if (should_notify_stop
)
4063 /* We may not find an inferior if this was a process exit. */
4064 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4065 proceeded
= normal_stop ();
4070 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4074 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4075 previously selected thread is gone. We have two
4076 choices - switch to no thread selected, or restore the
4077 previously selected thread (now exited). We chose the
4078 later, just because that's what GDB used to do. After
4079 this, "info threads" says "The current thread <Thread
4080 ID 2> has terminated." instead of "No thread
4084 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4085 restore_thread
.dont_restore ();
4089 defer_delete_threads
.release ();
4090 defer_bpstat_clear
.release ();
4092 /* No error, don't finish the thread states yet. */
4093 finish_state
.release ();
4095 /* This scope is used to ensure that readline callbacks are
4096 reinstalled here. */
4099 /* If a UI was in sync execution mode, and now isn't, restore its
4100 prompt (a synchronous execution command has finished, and we're
4101 ready for input). */
4102 all_uis_check_sync_execution_done ();
4105 && exec_done_display_p
4106 && (inferior_ptid
== null_ptid
4107 || inferior_thread ()->state
!= THREAD_RUNNING
))
4108 printf_unfiltered (_("completed.\n"));
4114 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4115 struct symtab_and_line sal
)
4117 /* This can be removed once this function no longer implicitly relies on the
4118 inferior_ptid value. */
4119 gdb_assert (inferior_ptid
== tp
->ptid
);
4121 tp
->control
.step_frame_id
= get_frame_id (frame
);
4122 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4124 tp
->current_symtab
= sal
.symtab
;
4125 tp
->current_line
= sal
.line
;
4128 /* Clear context switchable stepping state. */
4131 init_thread_stepping_state (struct thread_info
*tss
)
4133 tss
->stepped_breakpoint
= 0;
4134 tss
->stepping_over_breakpoint
= 0;
4135 tss
->stepping_over_watchpoint
= 0;
4136 tss
->step_after_step_resume_breakpoint
= 0;
4142 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4143 target_waitstatus status
)
4145 target_last_proc_target
= target
;
4146 target_last_wait_ptid
= ptid
;
4147 target_last_waitstatus
= status
;
4153 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4154 target_waitstatus
*status
)
4156 if (target
!= nullptr)
4157 *target
= target_last_proc_target
;
4158 if (ptid
!= nullptr)
4159 *ptid
= target_last_wait_ptid
;
4160 if (status
!= nullptr)
4161 *status
= target_last_waitstatus
;
4167 nullify_last_target_wait_ptid (void)
4169 target_last_proc_target
= nullptr;
4170 target_last_wait_ptid
= minus_one_ptid
;
4171 target_last_waitstatus
= {};
4174 /* Switch thread contexts. */
4177 context_switch (execution_control_state
*ecs
)
4180 && ecs
->ptid
!= inferior_ptid
4181 && (inferior_ptid
== null_ptid
4182 || ecs
->event_thread
!= inferior_thread ()))
4184 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4185 target_pid_to_str (inferior_ptid
).c_str ());
4186 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4187 target_pid_to_str (ecs
->ptid
).c_str ());
4190 switch_to_thread (ecs
->event_thread
);
4193 /* If the target can't tell whether we've hit breakpoints
4194 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4195 check whether that could have been caused by a breakpoint. If so,
4196 adjust the PC, per gdbarch_decr_pc_after_break. */
4199 adjust_pc_after_break (struct thread_info
*thread
,
4200 struct target_waitstatus
*ws
)
4202 struct regcache
*regcache
;
4203 struct gdbarch
*gdbarch
;
4204 CORE_ADDR breakpoint_pc
, decr_pc
;
4206 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4207 we aren't, just return.
4209 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4210 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4211 implemented by software breakpoints should be handled through the normal
4214 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4215 different signals (SIGILL or SIGEMT for instance), but it is less
4216 clear where the PC is pointing afterwards. It may not match
4217 gdbarch_decr_pc_after_break. I don't know any specific target that
4218 generates these signals at breakpoints (the code has been in GDB since at
4219 least 1992) so I can not guess how to handle them here.
4221 In earlier versions of GDB, a target with
4222 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4223 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4224 target with both of these set in GDB history, and it seems unlikely to be
4225 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4227 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4230 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4233 /* In reverse execution, when a breakpoint is hit, the instruction
4234 under it has already been de-executed. The reported PC always
4235 points at the breakpoint address, so adjusting it further would
4236 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4239 B1 0x08000000 : INSN1
4240 B2 0x08000001 : INSN2
4242 PC -> 0x08000003 : INSN4
4244 Say you're stopped at 0x08000003 as above. Reverse continuing
4245 from that point should hit B2 as below. Reading the PC when the
4246 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4247 been de-executed already.
4249 B1 0x08000000 : INSN1
4250 B2 PC -> 0x08000001 : INSN2
4254 We can't apply the same logic as for forward execution, because
4255 we would wrongly adjust the PC to 0x08000000, since there's a
4256 breakpoint at PC - 1. We'd then report a hit on B1, although
4257 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4259 if (execution_direction
== EXEC_REVERSE
)
4262 /* If the target can tell whether the thread hit a SW breakpoint,
4263 trust it. Targets that can tell also adjust the PC
4265 if (target_supports_stopped_by_sw_breakpoint ())
4268 /* Note that relying on whether a breakpoint is planted in memory to
4269 determine this can fail. E.g,. the breakpoint could have been
4270 removed since. Or the thread could have been told to step an
4271 instruction the size of a breakpoint instruction, and only
4272 _after_ was a breakpoint inserted at its address. */
4274 /* If this target does not decrement the PC after breakpoints, then
4275 we have nothing to do. */
4276 regcache
= get_thread_regcache (thread
);
4277 gdbarch
= regcache
->arch ();
4279 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4283 const address_space
*aspace
= regcache
->aspace ();
4285 /* Find the location where (if we've hit a breakpoint) the
4286 breakpoint would be. */
4287 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4289 /* If the target can't tell whether a software breakpoint triggered,
4290 fallback to figuring it out based on breakpoints we think were
4291 inserted in the target, and on whether the thread was stepped or
4294 /* Check whether there actually is a software breakpoint inserted at
4297 If in non-stop mode, a race condition is possible where we've
4298 removed a breakpoint, but stop events for that breakpoint were
4299 already queued and arrive later. To suppress those spurious
4300 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4301 and retire them after a number of stop events are reported. Note
4302 this is an heuristic and can thus get confused. The real fix is
4303 to get the "stopped by SW BP and needs adjustment" info out of
4304 the target/kernel (and thus never reach here; see above). */
4305 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4306 || (target_is_non_stop_p ()
4307 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4309 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4311 if (record_full_is_used ())
4312 restore_operation_disable
.emplace
4313 (record_full_gdb_operation_disable_set ());
4315 /* When using hardware single-step, a SIGTRAP is reported for both
4316 a completed single-step and a software breakpoint. Need to
4317 differentiate between the two, as the latter needs adjusting
4318 but the former does not.
4320 The SIGTRAP can be due to a completed hardware single-step only if
4321 - we didn't insert software single-step breakpoints
4322 - this thread is currently being stepped
4324 If any of these events did not occur, we must have stopped due
4325 to hitting a software breakpoint, and have to back up to the
4328 As a special case, we could have hardware single-stepped a
4329 software breakpoint. In this case (prev_pc == breakpoint_pc),
4330 we also need to back up to the breakpoint address. */
4332 if (thread_has_single_step_breakpoints_set (thread
)
4333 || !currently_stepping (thread
)
4334 || (thread
->stepped_breakpoint
4335 && thread
->prev_pc
== breakpoint_pc
))
4336 regcache_write_pc (regcache
, breakpoint_pc
);
4341 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4343 for (frame
= get_prev_frame (frame
);
4345 frame
= get_prev_frame (frame
))
4347 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4349 if (get_frame_type (frame
) != INLINE_FRAME
)
4356 /* Look for an inline frame that is marked for skip.
4357 If PREV_FRAME is TRUE start at the previous frame,
4358 otherwise start at the current frame. Stop at the
4359 first non-inline frame, or at the frame where the
4363 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4365 struct frame_info
*frame
= get_current_frame ();
4368 frame
= get_prev_frame (frame
);
4370 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4372 const char *fn
= NULL
;
4373 symtab_and_line sal
;
4376 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4378 if (get_frame_type (frame
) != INLINE_FRAME
)
4381 sal
= find_frame_sal (frame
);
4382 sym
= get_frame_function (frame
);
4385 fn
= sym
->print_name ();
4388 && function_name_is_marked_for_skip (fn
, sal
))
4395 /* If the event thread has the stop requested flag set, pretend it
4396 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4400 handle_stop_requested (struct execution_control_state
*ecs
)
4402 if (ecs
->event_thread
->stop_requested
)
4404 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4405 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4406 handle_signal_stop (ecs
);
4412 /* Auxiliary function that handles syscall entry/return events.
4413 It returns 1 if the inferior should keep going (and GDB
4414 should ignore the event), or 0 if the event deserves to be
4418 handle_syscall_event (struct execution_control_state
*ecs
)
4420 struct regcache
*regcache
;
4423 context_switch (ecs
);
4425 regcache
= get_thread_regcache (ecs
->event_thread
);
4426 syscall_number
= ecs
->ws
.value
.syscall_number
;
4427 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4429 if (catch_syscall_enabled () > 0
4430 && catching_syscall_number (syscall_number
) > 0)
4433 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4436 ecs
->event_thread
->control
.stop_bpstat
4437 = bpstat_stop_status (regcache
->aspace (),
4438 ecs
->event_thread
->suspend
.stop_pc
,
4439 ecs
->event_thread
, &ecs
->ws
);
4441 if (handle_stop_requested (ecs
))
4444 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4446 /* Catchpoint hit. */
4451 if (handle_stop_requested (ecs
))
4454 /* If no catchpoint triggered for this, then keep going. */
4459 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4462 fill_in_stop_func (struct gdbarch
*gdbarch
,
4463 struct execution_control_state
*ecs
)
4465 if (!ecs
->stop_func_filled_in
)
4469 /* Don't care about return value; stop_func_start and stop_func_name
4470 will both be 0 if it doesn't work. */
4471 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4472 &ecs
->stop_func_name
,
4473 &ecs
->stop_func_start
,
4474 &ecs
->stop_func_end
,
4477 /* The call to find_pc_partial_function, above, will set
4478 stop_func_start and stop_func_end to the start and end
4479 of the range containing the stop pc. If this range
4480 contains the entry pc for the block (which is always the
4481 case for contiguous blocks), advance stop_func_start past
4482 the function's start offset and entrypoint. Note that
4483 stop_func_start is NOT advanced when in a range of a
4484 non-contiguous block that does not contain the entry pc. */
4485 if (block
!= nullptr
4486 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4487 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4489 ecs
->stop_func_start
4490 += gdbarch_deprecated_function_start_offset (gdbarch
);
4492 if (gdbarch_skip_entrypoint_p (gdbarch
))
4493 ecs
->stop_func_start
4494 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4497 ecs
->stop_func_filled_in
= 1;
4502 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4504 static enum stop_kind
4505 get_inferior_stop_soon (execution_control_state
*ecs
)
4507 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4509 gdb_assert (inf
!= NULL
);
4510 return inf
->control
.stop_soon
;
4513 /* Poll for one event out of the current target. Store the resulting
4514 waitstatus in WS, and return the event ptid. Does not block. */
4517 poll_one_curr_target (struct target_waitstatus
*ws
)
4521 overlay_cache_invalid
= 1;
4523 /* Flush target cache before starting to handle each event.
4524 Target was running and cache could be stale. This is just a
4525 heuristic. Running threads may modify target memory, but we
4526 don't get any event. */
4527 target_dcache_invalidate ();
4529 if (deprecated_target_wait_hook
)
4530 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4532 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4535 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4540 /* An event reported by wait_one. */
4542 struct wait_one_event
4544 /* The target the event came out of. */
4545 process_stratum_target
*target
;
4547 /* The PTID the event was for. */
4550 /* The waitstatus. */
4551 target_waitstatus ws
;
4554 /* Wait for one event out of any target. */
4556 static wait_one_event
4561 for (inferior
*inf
: all_inferiors ())
4563 process_stratum_target
*target
= inf
->process_target ();
4565 || !target
->is_async_p ()
4566 || !target
->threads_executing
)
4569 switch_to_inferior_no_thread (inf
);
4571 wait_one_event event
;
4572 event
.target
= target
;
4573 event
.ptid
= poll_one_curr_target (&event
.ws
);
4575 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4577 /* If nothing is resumed, remove the target from the
4581 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4585 /* Block waiting for some event. */
4592 for (inferior
*inf
: all_inferiors ())
4594 process_stratum_target
*target
= inf
->process_target ();
4596 || !target
->is_async_p ()
4597 || !target
->threads_executing
)
4600 int fd
= target
->async_wait_fd ();
4601 FD_SET (fd
, &readfds
);
4608 /* No waitable targets left. All must be stopped. */
4609 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4614 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4620 perror_with_name ("interruptible_select");
4625 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4626 instead of the current thread. */
4627 #define THREAD_STOPPED_BY(REASON) \
4629 thread_stopped_by_ ## REASON (ptid_t ptid) \
4631 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4632 inferior_ptid = ptid; \
4634 return target_stopped_by_ ## REASON (); \
4637 /* Generate thread_stopped_by_watchpoint. */
4638 THREAD_STOPPED_BY (watchpoint
)
4639 /* Generate thread_stopped_by_sw_breakpoint. */
4640 THREAD_STOPPED_BY (sw_breakpoint
)
4641 /* Generate thread_stopped_by_hw_breakpoint. */
4642 THREAD_STOPPED_BY (hw_breakpoint
)
4644 /* Save the thread's event and stop reason to process it later. */
4647 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4651 std::string statstr
= target_waitstatus_to_string (ws
);
4653 fprintf_unfiltered (gdb_stdlog
,
4654 "infrun: saving status %s for %d.%ld.%ld\n",
4661 /* Record for later. */
4662 tp
->suspend
.waitstatus
= *ws
;
4663 tp
->suspend
.waitstatus_pending_p
= 1;
4665 struct regcache
*regcache
= get_thread_regcache (tp
);
4666 const address_space
*aspace
= regcache
->aspace ();
4668 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4669 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4671 CORE_ADDR pc
= regcache_read_pc (regcache
);
4673 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4675 if (thread_stopped_by_watchpoint (tp
->ptid
))
4677 tp
->suspend
.stop_reason
4678 = TARGET_STOPPED_BY_WATCHPOINT
;
4680 else if (target_supports_stopped_by_sw_breakpoint ()
4681 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4683 tp
->suspend
.stop_reason
4684 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4686 else if (target_supports_stopped_by_hw_breakpoint ()
4687 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4689 tp
->suspend
.stop_reason
4690 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4692 else if (!target_supports_stopped_by_hw_breakpoint ()
4693 && hardware_breakpoint_inserted_here_p (aspace
,
4696 tp
->suspend
.stop_reason
4697 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4699 else if (!target_supports_stopped_by_sw_breakpoint ()
4700 && software_breakpoint_inserted_here_p (aspace
,
4703 tp
->suspend
.stop_reason
4704 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4706 else if (!thread_has_single_step_breakpoints_set (tp
)
4707 && currently_stepping (tp
))
4709 tp
->suspend
.stop_reason
4710 = TARGET_STOPPED_BY_SINGLE_STEP
;
4715 /* Mark the non-executing threads accordingly. In all-stop, all
4716 threads of all processes are stopped when we get any event
4717 reported. In non-stop mode, only the event thread stops. */
4720 mark_non_executing_threads (process_stratum_target
*target
,
4722 struct target_waitstatus ws
)
4726 if (!target_is_non_stop_p ())
4727 mark_ptid
= minus_one_ptid
;
4728 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4729 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4731 /* If we're handling a process exit in non-stop mode, even
4732 though threads haven't been deleted yet, one would think
4733 that there is nothing to do, as threads of the dead process
4734 will be soon deleted, and threads of any other process were
4735 left running. However, on some targets, threads survive a
4736 process exit event. E.g., for the "checkpoint" command,
4737 when the current checkpoint/fork exits, linux-fork.c
4738 automatically switches to another fork from within
4739 target_mourn_inferior, by associating the same
4740 inferior/thread to another fork. We haven't mourned yet at
4741 this point, but we must mark any threads left in the
4742 process as not-executing so that finish_thread_state marks
4743 them stopped (in the user's perspective) if/when we present
4744 the stop to the user. */
4745 mark_ptid
= ptid_t (event_ptid
.pid ());
4748 mark_ptid
= event_ptid
;
4750 set_executing (target
, mark_ptid
, false);
4752 /* Likewise the resumed flag. */
4753 set_resumed (target
, mark_ptid
, false);
4759 stop_all_threads (void)
4761 /* We may need multiple passes to discover all threads. */
4765 gdb_assert (exists_non_stop_target ());
4768 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4770 scoped_restore_current_thread restore_thread
;
4772 /* Enable thread events of all targets. */
4773 for (auto *target
: all_non_exited_process_targets ())
4775 switch_to_target_no_thread (target
);
4776 target_thread_events (true);
4781 /* Disable thread events of all targets. */
4782 for (auto *target
: all_non_exited_process_targets ())
4784 switch_to_target_no_thread (target
);
4785 target_thread_events (false);
4789 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4792 /* Request threads to stop, and then wait for the stops. Because
4793 threads we already know about can spawn more threads while we're
4794 trying to stop them, and we only learn about new threads when we
4795 update the thread list, do this in a loop, and keep iterating
4796 until two passes find no threads that need to be stopped. */
4797 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4800 fprintf_unfiltered (gdb_stdlog
,
4801 "infrun: stop_all_threads, pass=%d, "
4802 "iterations=%d\n", pass
, iterations
);
4807 update_thread_list ();
4809 /* Go through all threads looking for threads that we need
4810 to tell the target to stop. */
4811 for (thread_info
*t
: all_non_exited_threads ())
4813 /* For a single-target setting with an all-stop target,
4814 we would not even arrive here. For a multi-target
4815 setting, until GDB is able to handle a mixture of
4816 all-stop and non-stop targets, simply skip all-stop
4817 targets' threads. This should be fine due to the
4818 protection of 'check_multi_target_resumption'. */
4820 switch_to_thread_no_regs (t
);
4821 if (!target_is_non_stop_p ())
4826 /* If already stopping, don't request a stop again.
4827 We just haven't seen the notification yet. */
4828 if (!t
->stop_requested
)
4831 fprintf_unfiltered (gdb_stdlog
,
4832 "infrun: %s executing, "
4834 target_pid_to_str (t
->ptid
).c_str ());
4835 target_stop (t
->ptid
);
4836 t
->stop_requested
= 1;
4841 fprintf_unfiltered (gdb_stdlog
,
4842 "infrun: %s executing, "
4843 "already stopping\n",
4844 target_pid_to_str (t
->ptid
).c_str ());
4847 if (t
->stop_requested
)
4853 fprintf_unfiltered (gdb_stdlog
,
4854 "infrun: %s not executing\n",
4855 target_pid_to_str (t
->ptid
).c_str ());
4857 /* The thread may be not executing, but still be
4858 resumed with a pending status to process. */
4866 /* If we find new threads on the second iteration, restart
4867 over. We want to see two iterations in a row with all
4872 wait_one_event event
= wait_one ();
4876 fprintf_unfiltered (gdb_stdlog
,
4877 "infrun: stop_all_threads %s %s\n",
4878 target_waitstatus_to_string (&event
.ws
).c_str (),
4879 target_pid_to_str (event
.ptid
).c_str ());
4882 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4883 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4884 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4885 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4887 /* All resumed threads exited
4888 or one thread/process exited/signalled. */
4892 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4894 t
= add_thread (event
.target
, event
.ptid
);
4896 t
->stop_requested
= 0;
4899 t
->control
.may_range_step
= 0;
4901 /* This may be the first time we see the inferior report
4903 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4904 if (inf
->needs_setup
)
4906 switch_to_thread_no_regs (t
);
4910 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4911 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4913 /* We caught the event that we intended to catch, so
4914 there's no event pending. */
4915 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4916 t
->suspend
.waitstatus_pending_p
= 0;
4918 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4920 /* Add it back to the step-over queue. */
4923 fprintf_unfiltered (gdb_stdlog
,
4924 "infrun: displaced-step of %s "
4925 "canceled: adding back to the "
4926 "step-over queue\n",
4927 target_pid_to_str (t
->ptid
).c_str ());
4929 t
->control
.trap_expected
= 0;
4930 thread_step_over_chain_enqueue (t
);
4935 enum gdb_signal sig
;
4936 struct regcache
*regcache
;
4940 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4942 fprintf_unfiltered (gdb_stdlog
,
4943 "infrun: target_wait %s, saving "
4944 "status for %d.%ld.%ld\n",
4951 /* Record for later. */
4952 save_waitstatus (t
, &event
.ws
);
4954 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4955 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4957 if (displaced_step_fixup (t
, sig
) < 0)
4959 /* Add it back to the step-over queue. */
4960 t
->control
.trap_expected
= 0;
4961 thread_step_over_chain_enqueue (t
);
4964 regcache
= get_thread_regcache (t
);
4965 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4969 fprintf_unfiltered (gdb_stdlog
,
4970 "infrun: saved stop_pc=%s for %s "
4971 "(currently_stepping=%d)\n",
4972 paddress (target_gdbarch (),
4973 t
->suspend
.stop_pc
),
4974 target_pid_to_str (t
->ptid
).c_str (),
4975 currently_stepping (t
));
4983 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4986 handle_no_resumed (struct execution_control_state
*ecs
)
4988 if (target_can_async_p ())
4995 if (ui
->prompt_state
== PROMPT_BLOCKED
)
5003 /* There were no unwaited-for children left in the target, but,
5004 we're not synchronously waiting for events either. Just
5008 fprintf_unfiltered (gdb_stdlog
,
5009 "infrun: TARGET_WAITKIND_NO_RESUMED "
5010 "(ignoring: bg)\n");
5011 prepare_to_wait (ecs
);
5016 /* Otherwise, if we were running a synchronous execution command, we
5017 may need to cancel it and give the user back the terminal.
5019 In non-stop mode, the target can't tell whether we've already
5020 consumed previous stop events, so it can end up sending us a
5021 no-resumed event like so:
5023 #0 - thread 1 is left stopped
5025 #1 - thread 2 is resumed and hits breakpoint
5026 -> TARGET_WAITKIND_STOPPED
5028 #2 - thread 3 is resumed and exits
5029 this is the last resumed thread, so
5030 -> TARGET_WAITKIND_NO_RESUMED
5032 #3 - gdb processes stop for thread 2 and decides to re-resume
5035 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
5036 thread 2 is now resumed, so the event should be ignored.
5038 IOW, if the stop for thread 2 doesn't end a foreground command,
5039 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
5040 event. But it could be that the event meant that thread 2 itself
5041 (or whatever other thread was the last resumed thread) exited.
5043 To address this we refresh the thread list and check whether we
5044 have resumed threads _now_. In the example above, this removes
5045 thread 3 from the thread list. If thread 2 was re-resumed, we
5046 ignore this event. If we find no thread resumed, then we cancel
5047 the synchronous command show "no unwaited-for " to the user. */
5048 update_thread_list ();
5050 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
5052 if (thread
->executing
5053 || thread
->suspend
.waitstatus_pending_p
)
5055 /* There were no unwaited-for children left in the target at
5056 some point, but there are now. Just ignore. */
5058 fprintf_unfiltered (gdb_stdlog
,
5059 "infrun: TARGET_WAITKIND_NO_RESUMED "
5060 "(ignoring: found resumed)\n");
5061 prepare_to_wait (ecs
);
5066 /* Note however that we may find no resumed thread because the whole
5067 process exited meanwhile (thus updating the thread list results
5068 in an empty thread list). In this case we know we'll be getting
5069 a process exit event shortly. */
5070 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
5072 thread_info
*thread
= any_live_thread_of_inferior (inf
);
5076 fprintf_unfiltered (gdb_stdlog
,
5077 "infrun: TARGET_WAITKIND_NO_RESUMED "
5078 "(expect process exit)\n");
5079 prepare_to_wait (ecs
);
5084 /* Go ahead and report the event. */
5088 /* Given an execution control state that has been freshly filled in by
5089 an event from the inferior, figure out what it means and take
5092 The alternatives are:
5094 1) stop_waiting and return; to really stop and return to the
5097 2) keep_going and return; to wait for the next event (set
5098 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5102 handle_inferior_event (struct execution_control_state
*ecs
)
5104 /* Make sure that all temporary struct value objects that were
5105 created during the handling of the event get deleted at the
5107 scoped_value_mark free_values
;
5109 enum stop_kind stop_soon
;
5112 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5113 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5115 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5117 /* We had an event in the inferior, but we are not interested in
5118 handling it at this level. The lower layers have already
5119 done what needs to be done, if anything.
5121 One of the possible circumstances for this is when the
5122 inferior produces output for the console. The inferior has
5123 not stopped, and we are ignoring the event. Another possible
5124 circumstance is any event which the lower level knows will be
5125 reported multiple times without an intervening resume. */
5126 prepare_to_wait (ecs
);
5130 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5132 prepare_to_wait (ecs
);
5136 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5137 && handle_no_resumed (ecs
))
5140 /* Cache the last target/ptid/waitstatus. */
5141 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5143 /* Always clear state belonging to the previous time we stopped. */
5144 stop_stack_dummy
= STOP_NONE
;
5146 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5148 /* No unwaited-for children left. IOW, all resumed children
5150 stop_print_frame
= 0;
5155 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5156 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5158 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5159 /* If it's a new thread, add it to the thread database. */
5160 if (ecs
->event_thread
== NULL
)
5161 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5163 /* Disable range stepping. If the next step request could use a
5164 range, this will be end up re-enabled then. */
5165 ecs
->event_thread
->control
.may_range_step
= 0;
5168 /* Dependent on valid ECS->EVENT_THREAD. */
5169 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5171 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5172 reinit_frame_cache ();
5174 breakpoint_retire_moribund ();
5176 /* First, distinguish signals caused by the debugger from signals
5177 that have to do with the program's own actions. Note that
5178 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5179 on the operating system version. Here we detect when a SIGILL or
5180 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5181 something similar for SIGSEGV, since a SIGSEGV will be generated
5182 when we're trying to execute a breakpoint instruction on a
5183 non-executable stack. This happens for call dummy breakpoints
5184 for architectures like SPARC that place call dummies on the
5186 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5187 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5188 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5189 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5191 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5193 if (breakpoint_inserted_here_p (regcache
->aspace (),
5194 regcache_read_pc (regcache
)))
5197 fprintf_unfiltered (gdb_stdlog
,
5198 "infrun: Treating signal as SIGTRAP\n");
5199 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5203 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5205 switch (ecs
->ws
.kind
)
5207 case TARGET_WAITKIND_LOADED
:
5208 context_switch (ecs
);
5209 /* Ignore gracefully during startup of the inferior, as it might
5210 be the shell which has just loaded some objects, otherwise
5211 add the symbols for the newly loaded objects. Also ignore at
5212 the beginning of an attach or remote session; we will query
5213 the full list of libraries once the connection is
5216 stop_soon
= get_inferior_stop_soon (ecs
);
5217 if (stop_soon
== NO_STOP_QUIETLY
)
5219 struct regcache
*regcache
;
5221 regcache
= get_thread_regcache (ecs
->event_thread
);
5223 handle_solib_event ();
5225 ecs
->event_thread
->control
.stop_bpstat
5226 = bpstat_stop_status (regcache
->aspace (),
5227 ecs
->event_thread
->suspend
.stop_pc
,
5228 ecs
->event_thread
, &ecs
->ws
);
5230 if (handle_stop_requested (ecs
))
5233 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5235 /* A catchpoint triggered. */
5236 process_event_stop_test (ecs
);
5240 /* If requested, stop when the dynamic linker notifies
5241 gdb of events. This allows the user to get control
5242 and place breakpoints in initializer routines for
5243 dynamically loaded objects (among other things). */
5244 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5245 if (stop_on_solib_events
)
5247 /* Make sure we print "Stopped due to solib-event" in
5249 stop_print_frame
= 1;
5256 /* If we are skipping through a shell, or through shared library
5257 loading that we aren't interested in, resume the program. If
5258 we're running the program normally, also resume. */
5259 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5261 /* Loading of shared libraries might have changed breakpoint
5262 addresses. Make sure new breakpoints are inserted. */
5263 if (stop_soon
== NO_STOP_QUIETLY
)
5264 insert_breakpoints ();
5265 resume (GDB_SIGNAL_0
);
5266 prepare_to_wait (ecs
);
5270 /* But stop if we're attaching or setting up a remote
5272 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5273 || stop_soon
== STOP_QUIETLY_REMOTE
)
5276 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5281 internal_error (__FILE__
, __LINE__
,
5282 _("unhandled stop_soon: %d"), (int) stop_soon
);
5284 case TARGET_WAITKIND_SPURIOUS
:
5285 if (handle_stop_requested (ecs
))
5287 context_switch (ecs
);
5288 resume (GDB_SIGNAL_0
);
5289 prepare_to_wait (ecs
);
5292 case TARGET_WAITKIND_THREAD_CREATED
:
5293 if (handle_stop_requested (ecs
))
5295 context_switch (ecs
);
5296 if (!switch_back_to_stepped_thread (ecs
))
5300 case TARGET_WAITKIND_EXITED
:
5301 case TARGET_WAITKIND_SIGNALLED
:
5302 inferior_ptid
= ecs
->ptid
;
5303 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5304 set_current_program_space (current_inferior ()->pspace
);
5305 handle_vfork_child_exec_or_exit (0);
5306 target_terminal::ours (); /* Must do this before mourn anyway. */
5308 /* Clearing any previous state of convenience variables. */
5309 clear_exit_convenience_vars ();
5311 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5313 /* Record the exit code in the convenience variable $_exitcode, so
5314 that the user can inspect this again later. */
5315 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5316 (LONGEST
) ecs
->ws
.value
.integer
);
5318 /* Also record this in the inferior itself. */
5319 current_inferior ()->has_exit_code
= 1;
5320 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5322 /* Support the --return-child-result option. */
5323 return_child_result_value
= ecs
->ws
.value
.integer
;
5325 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5329 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5331 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5333 /* Set the value of the internal variable $_exitsignal,
5334 which holds the signal uncaught by the inferior. */
5335 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5336 gdbarch_gdb_signal_to_target (gdbarch
,
5337 ecs
->ws
.value
.sig
));
5341 /* We don't have access to the target's method used for
5342 converting between signal numbers (GDB's internal
5343 representation <-> target's representation).
5344 Therefore, we cannot do a good job at displaying this
5345 information to the user. It's better to just warn
5346 her about it (if infrun debugging is enabled), and
5349 fprintf_filtered (gdb_stdlog
, _("\
5350 Cannot fill $_exitsignal with the correct signal number.\n"));
5353 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5356 gdb_flush (gdb_stdout
);
5357 target_mourn_inferior (inferior_ptid
);
5358 stop_print_frame
= 0;
5362 case TARGET_WAITKIND_FORKED
:
5363 case TARGET_WAITKIND_VFORKED
:
5364 /* Check whether the inferior is displaced stepping. */
5366 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5367 struct gdbarch
*gdbarch
= regcache
->arch ();
5369 /* If checking displaced stepping is supported, and thread
5370 ecs->ptid is displaced stepping. */
5371 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5373 struct inferior
*parent_inf
5374 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5375 struct regcache
*child_regcache
;
5376 CORE_ADDR parent_pc
;
5378 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5380 struct displaced_step_inferior_state
*displaced
5381 = get_displaced_stepping_state (parent_inf
);
5383 /* Restore scratch pad for child process. */
5384 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5387 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5388 indicating that the displaced stepping of syscall instruction
5389 has been done. Perform cleanup for parent process here. Note
5390 that this operation also cleans up the child process for vfork,
5391 because their pages are shared. */
5392 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5393 /* Start a new step-over in another thread if there's one
5397 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5398 the child's PC is also within the scratchpad. Set the child's PC
5399 to the parent's PC value, which has already been fixed up.
5400 FIXME: we use the parent's aspace here, although we're touching
5401 the child, because the child hasn't been added to the inferior
5402 list yet at this point. */
5405 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5406 ecs
->ws
.value
.related_pid
,
5408 parent_inf
->aspace
);
5409 /* Read PC value of parent process. */
5410 parent_pc
= regcache_read_pc (regcache
);
5412 if (debug_displaced
)
5413 fprintf_unfiltered (gdb_stdlog
,
5414 "displaced: write child pc from %s to %s\n",
5416 regcache_read_pc (child_regcache
)),
5417 paddress (gdbarch
, parent_pc
));
5419 regcache_write_pc (child_regcache
, parent_pc
);
5423 context_switch (ecs
);
5425 /* Immediately detach breakpoints from the child before there's
5426 any chance of letting the user delete breakpoints from the
5427 breakpoint lists. If we don't do this early, it's easy to
5428 leave left over traps in the child, vis: "break foo; catch
5429 fork; c; <fork>; del; c; <child calls foo>". We only follow
5430 the fork on the last `continue', and by that time the
5431 breakpoint at "foo" is long gone from the breakpoint table.
5432 If we vforked, then we don't need to unpatch here, since both
5433 parent and child are sharing the same memory pages; we'll
5434 need to unpatch at follow/detach time instead to be certain
5435 that new breakpoints added between catchpoint hit time and
5436 vfork follow are detached. */
5437 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5439 /* This won't actually modify the breakpoint list, but will
5440 physically remove the breakpoints from the child. */
5441 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5444 delete_just_stopped_threads_single_step_breakpoints ();
5446 /* In case the event is caught by a catchpoint, remember that
5447 the event is to be followed at the next resume of the thread,
5448 and not immediately. */
5449 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5451 ecs
->event_thread
->suspend
.stop_pc
5452 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5454 ecs
->event_thread
->control
.stop_bpstat
5455 = bpstat_stop_status (get_current_regcache ()->aspace (),
5456 ecs
->event_thread
->suspend
.stop_pc
,
5457 ecs
->event_thread
, &ecs
->ws
);
5459 if (handle_stop_requested (ecs
))
5462 /* If no catchpoint triggered for this, then keep going. Note
5463 that we're interested in knowing the bpstat actually causes a
5464 stop, not just if it may explain the signal. Software
5465 watchpoints, for example, always appear in the bpstat. */
5466 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5469 = (follow_fork_mode_string
== follow_fork_mode_child
);
5471 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5473 process_stratum_target
*targ
5474 = ecs
->event_thread
->inf
->process_target ();
5476 bool should_resume
= follow_fork ();
5478 /* Note that one of these may be an invalid pointer,
5479 depending on detach_fork. */
5480 thread_info
*parent
= ecs
->event_thread
;
5482 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5484 /* At this point, the parent is marked running, and the
5485 child is marked stopped. */
5487 /* If not resuming the parent, mark it stopped. */
5488 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5489 parent
->set_running (false);
5491 /* If resuming the child, mark it running. */
5492 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5493 child
->set_running (true);
5495 /* In non-stop mode, also resume the other branch. */
5496 if (!detach_fork
&& (non_stop
5497 || (sched_multi
&& target_is_non_stop_p ())))
5500 switch_to_thread (parent
);
5502 switch_to_thread (child
);
5504 ecs
->event_thread
= inferior_thread ();
5505 ecs
->ptid
= inferior_ptid
;
5510 switch_to_thread (child
);
5512 switch_to_thread (parent
);
5514 ecs
->event_thread
= inferior_thread ();
5515 ecs
->ptid
= inferior_ptid
;
5523 process_event_stop_test (ecs
);
5526 case TARGET_WAITKIND_VFORK_DONE
:
5527 /* Done with the shared memory region. Re-insert breakpoints in
5528 the parent, and keep going. */
5530 context_switch (ecs
);
5532 current_inferior ()->waiting_for_vfork_done
= 0;
5533 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5535 if (handle_stop_requested (ecs
))
5538 /* This also takes care of reinserting breakpoints in the
5539 previously locked inferior. */
5543 case TARGET_WAITKIND_EXECD
:
5545 /* Note we can't read registers yet (the stop_pc), because we
5546 don't yet know the inferior's post-exec architecture.
5547 'stop_pc' is explicitly read below instead. */
5548 switch_to_thread_no_regs (ecs
->event_thread
);
5550 /* Do whatever is necessary to the parent branch of the vfork. */
5551 handle_vfork_child_exec_or_exit (1);
5553 /* This causes the eventpoints and symbol table to be reset.
5554 Must do this now, before trying to determine whether to
5556 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5558 /* In follow_exec we may have deleted the original thread and
5559 created a new one. Make sure that the event thread is the
5560 execd thread for that case (this is a nop otherwise). */
5561 ecs
->event_thread
= inferior_thread ();
5563 ecs
->event_thread
->suspend
.stop_pc
5564 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5566 ecs
->event_thread
->control
.stop_bpstat
5567 = bpstat_stop_status (get_current_regcache ()->aspace (),
5568 ecs
->event_thread
->suspend
.stop_pc
,
5569 ecs
->event_thread
, &ecs
->ws
);
5571 /* Note that this may be referenced from inside
5572 bpstat_stop_status above, through inferior_has_execd. */
5573 xfree (ecs
->ws
.value
.execd_pathname
);
5574 ecs
->ws
.value
.execd_pathname
= NULL
;
5576 if (handle_stop_requested (ecs
))
5579 /* If no catchpoint triggered for this, then keep going. */
5580 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5582 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5586 process_event_stop_test (ecs
);
5589 /* Be careful not to try to gather much state about a thread
5590 that's in a syscall. It's frequently a losing proposition. */
5591 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5592 /* Getting the current syscall number. */
5593 if (handle_syscall_event (ecs
) == 0)
5594 process_event_stop_test (ecs
);
5597 /* Before examining the threads further, step this thread to
5598 get it entirely out of the syscall. (We get notice of the
5599 event when the thread is just on the verge of exiting a
5600 syscall. Stepping one instruction seems to get it back
5602 case TARGET_WAITKIND_SYSCALL_RETURN
:
5603 if (handle_syscall_event (ecs
) == 0)
5604 process_event_stop_test (ecs
);
5607 case TARGET_WAITKIND_STOPPED
:
5608 handle_signal_stop (ecs
);
5611 case TARGET_WAITKIND_NO_HISTORY
:
5612 /* Reverse execution: target ran out of history info. */
5614 /* Switch to the stopped thread. */
5615 context_switch (ecs
);
5617 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5619 delete_just_stopped_threads_single_step_breakpoints ();
5620 ecs
->event_thread
->suspend
.stop_pc
5621 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5623 if (handle_stop_requested (ecs
))
5626 gdb::observers::no_history
.notify ();
5632 /* Restart threads back to what they were trying to do back when we
5633 paused them for an in-line step-over. The EVENT_THREAD thread is
5637 restart_threads (struct thread_info
*event_thread
)
5639 /* In case the instruction just stepped spawned a new thread. */
5640 update_thread_list ();
5642 for (thread_info
*tp
: all_non_exited_threads ())
5644 switch_to_thread_no_regs (tp
);
5646 if (tp
== event_thread
)
5649 fprintf_unfiltered (gdb_stdlog
,
5650 "infrun: restart threads: "
5651 "[%s] is event thread\n",
5652 target_pid_to_str (tp
->ptid
).c_str ());
5656 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5659 fprintf_unfiltered (gdb_stdlog
,
5660 "infrun: restart threads: "
5661 "[%s] not meant to be running\n",
5662 target_pid_to_str (tp
->ptid
).c_str ());
5669 fprintf_unfiltered (gdb_stdlog
,
5670 "infrun: restart threads: [%s] resumed\n",
5671 target_pid_to_str (tp
->ptid
).c_str ());
5672 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5676 if (thread_is_in_step_over_chain (tp
))
5679 fprintf_unfiltered (gdb_stdlog
,
5680 "infrun: restart threads: "
5681 "[%s] needs step-over\n",
5682 target_pid_to_str (tp
->ptid
).c_str ());
5683 gdb_assert (!tp
->resumed
);
5688 if (tp
->suspend
.waitstatus_pending_p
)
5691 fprintf_unfiltered (gdb_stdlog
,
5692 "infrun: restart threads: "
5693 "[%s] has pending status\n",
5694 target_pid_to_str (tp
->ptid
).c_str ());
5699 gdb_assert (!tp
->stop_requested
);
5701 /* If some thread needs to start a step-over at this point, it
5702 should still be in the step-over queue, and thus skipped
5704 if (thread_still_needs_step_over (tp
))
5706 internal_error (__FILE__
, __LINE__
,
5707 "thread [%s] needs a step-over, but not in "
5708 "step-over queue\n",
5709 target_pid_to_str (tp
->ptid
).c_str ());
5712 if (currently_stepping (tp
))
5715 fprintf_unfiltered (gdb_stdlog
,
5716 "infrun: restart threads: [%s] was stepping\n",
5717 target_pid_to_str (tp
->ptid
).c_str ());
5718 keep_going_stepped_thread (tp
);
5722 struct execution_control_state ecss
;
5723 struct execution_control_state
*ecs
= &ecss
;
5726 fprintf_unfiltered (gdb_stdlog
,
5727 "infrun: restart threads: [%s] continuing\n",
5728 target_pid_to_str (tp
->ptid
).c_str ());
5729 reset_ecs (ecs
, tp
);
5730 switch_to_thread (tp
);
5731 keep_going_pass_signal (ecs
);
5736 /* Callback for iterate_over_threads. Find a resumed thread that has
5737 a pending waitstatus. */
5740 resumed_thread_with_pending_status (struct thread_info
*tp
,
5744 && tp
->suspend
.waitstatus_pending_p
);
5747 /* Called when we get an event that may finish an in-line or
5748 out-of-line (displaced stepping) step-over started previously.
5749 Return true if the event is processed and we should go back to the
5750 event loop; false if the caller should continue processing the
5754 finish_step_over (struct execution_control_state
*ecs
)
5756 int had_step_over_info
;
5758 displaced_step_fixup (ecs
->event_thread
,
5759 ecs
->event_thread
->suspend
.stop_signal
);
5761 had_step_over_info
= step_over_info_valid_p ();
5763 if (had_step_over_info
)
5765 /* If we're stepping over a breakpoint with all threads locked,
5766 then only the thread that was stepped should be reporting
5768 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5770 clear_step_over_info ();
5773 if (!target_is_non_stop_p ())
5776 /* Start a new step-over in another thread if there's one that
5780 /* If we were stepping over a breakpoint before, and haven't started
5781 a new in-line step-over sequence, then restart all other threads
5782 (except the event thread). We can't do this in all-stop, as then
5783 e.g., we wouldn't be able to issue any other remote packet until
5784 these other threads stop. */
5785 if (had_step_over_info
&& !step_over_info_valid_p ())
5787 struct thread_info
*pending
;
5789 /* If we only have threads with pending statuses, the restart
5790 below won't restart any thread and so nothing re-inserts the
5791 breakpoint we just stepped over. But we need it inserted
5792 when we later process the pending events, otherwise if
5793 another thread has a pending event for this breakpoint too,
5794 we'd discard its event (because the breakpoint that
5795 originally caused the event was no longer inserted). */
5796 context_switch (ecs
);
5797 insert_breakpoints ();
5799 restart_threads (ecs
->event_thread
);
5801 /* If we have events pending, go through handle_inferior_event
5802 again, picking up a pending event at random. This avoids
5803 thread starvation. */
5805 /* But not if we just stepped over a watchpoint in order to let
5806 the instruction execute so we can evaluate its expression.
5807 The set of watchpoints that triggered is recorded in the
5808 breakpoint objects themselves (see bp->watchpoint_triggered).
5809 If we processed another event first, that other event could
5810 clobber this info. */
5811 if (ecs
->event_thread
->stepping_over_watchpoint
)
5814 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5816 if (pending
!= NULL
)
5818 struct thread_info
*tp
= ecs
->event_thread
;
5819 struct regcache
*regcache
;
5823 fprintf_unfiltered (gdb_stdlog
,
5824 "infrun: found resumed threads with "
5825 "pending events, saving status\n");
5828 gdb_assert (pending
!= tp
);
5830 /* Record the event thread's event for later. */
5831 save_waitstatus (tp
, &ecs
->ws
);
5832 /* This was cleared early, by handle_inferior_event. Set it
5833 so this pending event is considered by
5837 gdb_assert (!tp
->executing
);
5839 regcache
= get_thread_regcache (tp
);
5840 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5844 fprintf_unfiltered (gdb_stdlog
,
5845 "infrun: saved stop_pc=%s for %s "
5846 "(currently_stepping=%d)\n",
5847 paddress (target_gdbarch (),
5848 tp
->suspend
.stop_pc
),
5849 target_pid_to_str (tp
->ptid
).c_str (),
5850 currently_stepping (tp
));
5853 /* This in-line step-over finished; clear this so we won't
5854 start a new one. This is what handle_signal_stop would
5855 do, if we returned false. */
5856 tp
->stepping_over_breakpoint
= 0;
5858 /* Wake up the event loop again. */
5859 mark_async_event_handler (infrun_async_inferior_event_token
);
5861 prepare_to_wait (ecs
);
5869 /* Come here when the program has stopped with a signal. */
5872 handle_signal_stop (struct execution_control_state
*ecs
)
5874 struct frame_info
*frame
;
5875 struct gdbarch
*gdbarch
;
5876 int stopped_by_watchpoint
;
5877 enum stop_kind stop_soon
;
5880 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5882 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5884 /* Do we need to clean up the state of a thread that has
5885 completed a displaced single-step? (Doing so usually affects
5886 the PC, so do it here, before we set stop_pc.) */
5887 if (finish_step_over (ecs
))
5890 /* If we either finished a single-step or hit a breakpoint, but
5891 the user wanted this thread to be stopped, pretend we got a
5892 SIG0 (generic unsignaled stop). */
5893 if (ecs
->event_thread
->stop_requested
5894 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5895 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5897 ecs
->event_thread
->suspend
.stop_pc
5898 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5902 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5903 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5905 switch_to_thread (ecs
->event_thread
);
5907 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5908 paddress (reg_gdbarch
,
5909 ecs
->event_thread
->suspend
.stop_pc
));
5910 if (target_stopped_by_watchpoint ())
5914 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5916 if (target_stopped_data_address (current_top_target (), &addr
))
5917 fprintf_unfiltered (gdb_stdlog
,
5918 "infrun: stopped data address = %s\n",
5919 paddress (reg_gdbarch
, addr
));
5921 fprintf_unfiltered (gdb_stdlog
,
5922 "infrun: (no data address available)\n");
5926 /* This is originated from start_remote(), start_inferior() and
5927 shared libraries hook functions. */
5928 stop_soon
= get_inferior_stop_soon (ecs
);
5929 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5931 context_switch (ecs
);
5933 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5934 stop_print_frame
= 1;
5939 /* This originates from attach_command(). We need to overwrite
5940 the stop_signal here, because some kernels don't ignore a
5941 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5942 See more comments in inferior.h. On the other hand, if we
5943 get a non-SIGSTOP, report it to the user - assume the backend
5944 will handle the SIGSTOP if it should show up later.
5946 Also consider that the attach is complete when we see a
5947 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5948 target extended-remote report it instead of a SIGSTOP
5949 (e.g. gdbserver). We already rely on SIGTRAP being our
5950 signal, so this is no exception.
5952 Also consider that the attach is complete when we see a
5953 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5954 the target to stop all threads of the inferior, in case the
5955 low level attach operation doesn't stop them implicitly. If
5956 they weren't stopped implicitly, then the stub will report a
5957 GDB_SIGNAL_0, meaning: stopped for no particular reason
5958 other than GDB's request. */
5959 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5960 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5961 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5962 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5964 stop_print_frame
= 1;
5966 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5970 /* See if something interesting happened to the non-current thread. If
5971 so, then switch to that thread. */
5972 if (ecs
->ptid
!= inferior_ptid
)
5975 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5977 context_switch (ecs
);
5979 if (deprecated_context_hook
)
5980 deprecated_context_hook (ecs
->event_thread
->global_num
);
5983 /* At this point, get hold of the now-current thread's frame. */
5984 frame
= get_current_frame ();
5985 gdbarch
= get_frame_arch (frame
);
5987 /* Pull the single step breakpoints out of the target. */
5988 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5990 struct regcache
*regcache
;
5993 regcache
= get_thread_regcache (ecs
->event_thread
);
5994 const address_space
*aspace
= regcache
->aspace ();
5996 pc
= regcache_read_pc (regcache
);
5998 /* However, before doing so, if this single-step breakpoint was
5999 actually for another thread, set this thread up for moving
6001 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
6004 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
6008 fprintf_unfiltered (gdb_stdlog
,
6009 "infrun: [%s] hit another thread's "
6010 "single-step breakpoint\n",
6011 target_pid_to_str (ecs
->ptid
).c_str ());
6013 ecs
->hit_singlestep_breakpoint
= 1;
6020 fprintf_unfiltered (gdb_stdlog
,
6021 "infrun: [%s] hit its "
6022 "single-step breakpoint\n",
6023 target_pid_to_str (ecs
->ptid
).c_str ());
6027 delete_just_stopped_threads_single_step_breakpoints ();
6029 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6030 && ecs
->event_thread
->control
.trap_expected
6031 && ecs
->event_thread
->stepping_over_watchpoint
)
6032 stopped_by_watchpoint
= 0;
6034 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
6036 /* If necessary, step over this watchpoint. We'll be back to display
6038 if (stopped_by_watchpoint
6039 && (target_have_steppable_watchpoint
6040 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6042 /* At this point, we are stopped at an instruction which has
6043 attempted to write to a piece of memory under control of
6044 a watchpoint. The instruction hasn't actually executed
6045 yet. If we were to evaluate the watchpoint expression
6046 now, we would get the old value, and therefore no change
6047 would seem to have occurred.
6049 In order to make watchpoints work `right', we really need
6050 to complete the memory write, and then evaluate the
6051 watchpoint expression. We do this by single-stepping the
6054 It may not be necessary to disable the watchpoint to step over
6055 it. For example, the PA can (with some kernel cooperation)
6056 single step over a watchpoint without disabling the watchpoint.
6058 It is far more common to need to disable a watchpoint to step
6059 the inferior over it. If we have non-steppable watchpoints,
6060 we must disable the current watchpoint; it's simplest to
6061 disable all watchpoints.
6063 Any breakpoint at PC must also be stepped over -- if there's
6064 one, it will have already triggered before the watchpoint
6065 triggered, and we either already reported it to the user, or
6066 it didn't cause a stop and we called keep_going. In either
6067 case, if there was a breakpoint at PC, we must be trying to
6069 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6074 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6075 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6076 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6077 ecs
->event_thread
->control
.stop_step
= 0;
6078 stop_print_frame
= 1;
6079 stopped_by_random_signal
= 0;
6080 bpstat stop_chain
= NULL
;
6082 /* Hide inlined functions starting here, unless we just performed stepi or
6083 nexti. After stepi and nexti, always show the innermost frame (not any
6084 inline function call sites). */
6085 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6087 const address_space
*aspace
6088 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6090 /* skip_inline_frames is expensive, so we avoid it if we can
6091 determine that the address is one where functions cannot have
6092 been inlined. This improves performance with inferiors that
6093 load a lot of shared libraries, because the solib event
6094 breakpoint is defined as the address of a function (i.e. not
6095 inline). Note that we have to check the previous PC as well
6096 as the current one to catch cases when we have just
6097 single-stepped off a breakpoint prior to reinstating it.
6098 Note that we're assuming that the code we single-step to is
6099 not inline, but that's not definitive: there's nothing
6100 preventing the event breakpoint function from containing
6101 inlined code, and the single-step ending up there. If the
6102 user had set a breakpoint on that inlined code, the missing
6103 skip_inline_frames call would break things. Fortunately
6104 that's an extremely unlikely scenario. */
6105 if (!pc_at_non_inline_function (aspace
,
6106 ecs
->event_thread
->suspend
.stop_pc
,
6108 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6109 && ecs
->event_thread
->control
.trap_expected
6110 && pc_at_non_inline_function (aspace
,
6111 ecs
->event_thread
->prev_pc
,
6114 stop_chain
= build_bpstat_chain (aspace
,
6115 ecs
->event_thread
->suspend
.stop_pc
,
6117 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6119 /* Re-fetch current thread's frame in case that invalidated
6121 frame
= get_current_frame ();
6122 gdbarch
= get_frame_arch (frame
);
6126 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6127 && ecs
->event_thread
->control
.trap_expected
6128 && gdbarch_single_step_through_delay_p (gdbarch
)
6129 && currently_stepping (ecs
->event_thread
))
6131 /* We're trying to step off a breakpoint. Turns out that we're
6132 also on an instruction that needs to be stepped multiple
6133 times before it's been fully executing. E.g., architectures
6134 with a delay slot. It needs to be stepped twice, once for
6135 the instruction and once for the delay slot. */
6136 int step_through_delay
6137 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6139 if (debug_infrun
&& step_through_delay
)
6140 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6141 if (ecs
->event_thread
->control
.step_range_end
== 0
6142 && step_through_delay
)
6144 /* The user issued a continue when stopped at a breakpoint.
6145 Set up for another trap and get out of here. */
6146 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6150 else if (step_through_delay
)
6152 /* The user issued a step when stopped at a breakpoint.
6153 Maybe we should stop, maybe we should not - the delay
6154 slot *might* correspond to a line of source. In any
6155 case, don't decide that here, just set
6156 ecs->stepping_over_breakpoint, making sure we
6157 single-step again before breakpoints are re-inserted. */
6158 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6162 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6163 handles this event. */
6164 ecs
->event_thread
->control
.stop_bpstat
6165 = bpstat_stop_status (get_current_regcache ()->aspace (),
6166 ecs
->event_thread
->suspend
.stop_pc
,
6167 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6169 /* Following in case break condition called a
6171 stop_print_frame
= 1;
6173 /* This is where we handle "moribund" watchpoints. Unlike
6174 software breakpoints traps, hardware watchpoint traps are
6175 always distinguishable from random traps. If no high-level
6176 watchpoint is associated with the reported stop data address
6177 anymore, then the bpstat does not explain the signal ---
6178 simply make sure to ignore it if `stopped_by_watchpoint' is
6182 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6183 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6185 && stopped_by_watchpoint
)
6186 fprintf_unfiltered (gdb_stdlog
,
6187 "infrun: no user watchpoint explains "
6188 "watchpoint SIGTRAP, ignoring\n");
6190 /* NOTE: cagney/2003-03-29: These checks for a random signal
6191 at one stage in the past included checks for an inferior
6192 function call's call dummy's return breakpoint. The original
6193 comment, that went with the test, read:
6195 ``End of a stack dummy. Some systems (e.g. Sony news) give
6196 another signal besides SIGTRAP, so check here as well as
6199 If someone ever tries to get call dummys on a
6200 non-executable stack to work (where the target would stop
6201 with something like a SIGSEGV), then those tests might need
6202 to be re-instated. Given, however, that the tests were only
6203 enabled when momentary breakpoints were not being used, I
6204 suspect that it won't be the case.
6206 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6207 be necessary for call dummies on a non-executable stack on
6210 /* See if the breakpoints module can explain the signal. */
6212 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6213 ecs
->event_thread
->suspend
.stop_signal
);
6215 /* Maybe this was a trap for a software breakpoint that has since
6217 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6219 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6220 ecs
->event_thread
->suspend
.stop_pc
))
6222 struct regcache
*regcache
;
6225 /* Re-adjust PC to what the program would see if GDB was not
6227 regcache
= get_thread_regcache (ecs
->event_thread
);
6228 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6231 gdb::optional
<scoped_restore_tmpl
<int>>
6232 restore_operation_disable
;
6234 if (record_full_is_used ())
6235 restore_operation_disable
.emplace
6236 (record_full_gdb_operation_disable_set ());
6238 regcache_write_pc (regcache
,
6239 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6244 /* A delayed software breakpoint event. Ignore the trap. */
6246 fprintf_unfiltered (gdb_stdlog
,
6247 "infrun: delayed software breakpoint "
6248 "trap, ignoring\n");
6253 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6254 has since been removed. */
6255 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6257 /* A delayed hardware breakpoint event. Ignore the trap. */
6259 fprintf_unfiltered (gdb_stdlog
,
6260 "infrun: delayed hardware breakpoint/watchpoint "
6261 "trap, ignoring\n");
6265 /* If not, perhaps stepping/nexting can. */
6267 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6268 && currently_stepping (ecs
->event_thread
));
6270 /* Perhaps the thread hit a single-step breakpoint of _another_
6271 thread. Single-step breakpoints are transparent to the
6272 breakpoints module. */
6274 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6276 /* No? Perhaps we got a moribund watchpoint. */
6278 random_signal
= !stopped_by_watchpoint
;
6280 /* Always stop if the user explicitly requested this thread to
6282 if (ecs
->event_thread
->stop_requested
)
6286 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6289 /* For the program's own signals, act according to
6290 the signal handling tables. */
6294 /* Signal not for debugging purposes. */
6295 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6296 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6299 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6300 gdb_signal_to_symbol_string (stop_signal
));
6302 stopped_by_random_signal
= 1;
6304 /* Always stop on signals if we're either just gaining control
6305 of the program, or the user explicitly requested this thread
6306 to remain stopped. */
6307 if (stop_soon
!= NO_STOP_QUIETLY
6308 || ecs
->event_thread
->stop_requested
6310 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6316 /* Notify observers the signal has "handle print" set. Note we
6317 returned early above if stopping; normal_stop handles the
6318 printing in that case. */
6319 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6321 /* The signal table tells us to print about this signal. */
6322 target_terminal::ours_for_output ();
6323 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6324 target_terminal::inferior ();
6327 /* Clear the signal if it should not be passed. */
6328 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6329 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6331 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6332 && ecs
->event_thread
->control
.trap_expected
6333 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6335 /* We were just starting a new sequence, attempting to
6336 single-step off of a breakpoint and expecting a SIGTRAP.
6337 Instead this signal arrives. This signal will take us out
6338 of the stepping range so GDB needs to remember to, when
6339 the signal handler returns, resume stepping off that
6341 /* To simplify things, "continue" is forced to use the same
6342 code paths as single-step - set a breakpoint at the
6343 signal return address and then, once hit, step off that
6346 fprintf_unfiltered (gdb_stdlog
,
6347 "infrun: signal arrived while stepping over "
6350 insert_hp_step_resume_breakpoint_at_frame (frame
);
6351 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6352 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6353 ecs
->event_thread
->control
.trap_expected
= 0;
6355 /* If we were nexting/stepping some other thread, switch to
6356 it, so that we don't continue it, losing control. */
6357 if (!switch_back_to_stepped_thread (ecs
))
6362 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6363 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6365 || ecs
->event_thread
->control
.step_range_end
== 1)
6366 && frame_id_eq (get_stack_frame_id (frame
),
6367 ecs
->event_thread
->control
.step_stack_frame_id
)
6368 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6370 /* The inferior is about to take a signal that will take it
6371 out of the single step range. Set a breakpoint at the
6372 current PC (which is presumably where the signal handler
6373 will eventually return) and then allow the inferior to
6376 Note that this is only needed for a signal delivered
6377 while in the single-step range. Nested signals aren't a
6378 problem as they eventually all return. */
6380 fprintf_unfiltered (gdb_stdlog
,
6381 "infrun: signal may take us out of "
6382 "single-step range\n");
6384 clear_step_over_info ();
6385 insert_hp_step_resume_breakpoint_at_frame (frame
);
6386 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6387 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6388 ecs
->event_thread
->control
.trap_expected
= 0;
6393 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6394 when either there's a nested signal, or when there's a
6395 pending signal enabled just as the signal handler returns
6396 (leaving the inferior at the step-resume-breakpoint without
6397 actually executing it). Either way continue until the
6398 breakpoint is really hit. */
6400 if (!switch_back_to_stepped_thread (ecs
))
6403 fprintf_unfiltered (gdb_stdlog
,
6404 "infrun: random signal, keep going\n");
6411 process_event_stop_test (ecs
);
6414 /* Come here when we've got some debug event / signal we can explain
6415 (IOW, not a random signal), and test whether it should cause a
6416 stop, or whether we should resume the inferior (transparently).
6417 E.g., could be a breakpoint whose condition evaluates false; we
6418 could be still stepping within the line; etc. */
6421 process_event_stop_test (struct execution_control_state
*ecs
)
6423 struct symtab_and_line stop_pc_sal
;
6424 struct frame_info
*frame
;
6425 struct gdbarch
*gdbarch
;
6426 CORE_ADDR jmp_buf_pc
;
6427 struct bpstat_what what
;
6429 /* Handle cases caused by hitting a breakpoint. */
6431 frame
= get_current_frame ();
6432 gdbarch
= get_frame_arch (frame
);
6434 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6436 if (what
.call_dummy
)
6438 stop_stack_dummy
= what
.call_dummy
;
6441 /* A few breakpoint types have callbacks associated (e.g.,
6442 bp_jit_event). Run them now. */
6443 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6445 /* If we hit an internal event that triggers symbol changes, the
6446 current frame will be invalidated within bpstat_what (e.g., if we
6447 hit an internal solib event). Re-fetch it. */
6448 frame
= get_current_frame ();
6449 gdbarch
= get_frame_arch (frame
);
6451 switch (what
.main_action
)
6453 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6454 /* If we hit the breakpoint at longjmp while stepping, we
6455 install a momentary breakpoint at the target of the
6459 fprintf_unfiltered (gdb_stdlog
,
6460 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6462 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6464 if (what
.is_longjmp
)
6466 struct value
*arg_value
;
6468 /* If we set the longjmp breakpoint via a SystemTap probe,
6469 then use it to extract the arguments. The destination PC
6470 is the third argument to the probe. */
6471 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6474 jmp_buf_pc
= value_as_address (arg_value
);
6475 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6477 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6478 || !gdbarch_get_longjmp_target (gdbarch
,
6479 frame
, &jmp_buf_pc
))
6482 fprintf_unfiltered (gdb_stdlog
,
6483 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6484 "(!gdbarch_get_longjmp_target)\n");
6489 /* Insert a breakpoint at resume address. */
6490 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6493 check_exception_resume (ecs
, frame
);
6497 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6499 struct frame_info
*init_frame
;
6501 /* There are several cases to consider.
6503 1. The initiating frame no longer exists. In this case we
6504 must stop, because the exception or longjmp has gone too
6507 2. The initiating frame exists, and is the same as the
6508 current frame. We stop, because the exception or longjmp
6511 3. The initiating frame exists and is different from the
6512 current frame. This means the exception or longjmp has
6513 been caught beneath the initiating frame, so keep going.
6515 4. longjmp breakpoint has been placed just to protect
6516 against stale dummy frames and user is not interested in
6517 stopping around longjmps. */
6520 fprintf_unfiltered (gdb_stdlog
,
6521 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6523 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6525 delete_exception_resume_breakpoint (ecs
->event_thread
);
6527 if (what
.is_longjmp
)
6529 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6531 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6539 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6543 struct frame_id current_id
6544 = get_frame_id (get_current_frame ());
6545 if (frame_id_eq (current_id
,
6546 ecs
->event_thread
->initiating_frame
))
6548 /* Case 2. Fall through. */
6558 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6560 delete_step_resume_breakpoint (ecs
->event_thread
);
6562 end_stepping_range (ecs
);
6566 case BPSTAT_WHAT_SINGLE
:
6568 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6569 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6570 /* Still need to check other stuff, at least the case where we
6571 are stepping and step out of the right range. */
6574 case BPSTAT_WHAT_STEP_RESUME
:
6576 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6578 delete_step_resume_breakpoint (ecs
->event_thread
);
6579 if (ecs
->event_thread
->control
.proceed_to_finish
6580 && execution_direction
== EXEC_REVERSE
)
6582 struct thread_info
*tp
= ecs
->event_thread
;
6584 /* We are finishing a function in reverse, and just hit the
6585 step-resume breakpoint at the start address of the
6586 function, and we're almost there -- just need to back up
6587 by one more single-step, which should take us back to the
6589 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6593 fill_in_stop_func (gdbarch
, ecs
);
6594 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6595 && execution_direction
== EXEC_REVERSE
)
6597 /* We are stepping over a function call in reverse, and just
6598 hit the step-resume breakpoint at the start address of
6599 the function. Go back to single-stepping, which should
6600 take us back to the function call. */
6601 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6607 case BPSTAT_WHAT_STOP_NOISY
:
6609 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6610 stop_print_frame
= 1;
6612 /* Assume the thread stopped for a breapoint. We'll still check
6613 whether a/the breakpoint is there when the thread is next
6615 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6620 case BPSTAT_WHAT_STOP_SILENT
:
6622 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6623 stop_print_frame
= 0;
6625 /* Assume the thread stopped for a breapoint. We'll still check
6626 whether a/the breakpoint is there when the thread is next
6628 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6632 case BPSTAT_WHAT_HP_STEP_RESUME
:
6634 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6636 delete_step_resume_breakpoint (ecs
->event_thread
);
6637 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6639 /* Back when the step-resume breakpoint was inserted, we
6640 were trying to single-step off a breakpoint. Go back to
6642 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6643 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6649 case BPSTAT_WHAT_KEEP_CHECKING
:
6653 /* If we stepped a permanent breakpoint and we had a high priority
6654 step-resume breakpoint for the address we stepped, but we didn't
6655 hit it, then we must have stepped into the signal handler. The
6656 step-resume was only necessary to catch the case of _not_
6657 stepping into the handler, so delete it, and fall through to
6658 checking whether the step finished. */
6659 if (ecs
->event_thread
->stepped_breakpoint
)
6661 struct breakpoint
*sr_bp
6662 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6665 && sr_bp
->loc
->permanent
6666 && sr_bp
->type
== bp_hp_step_resume
6667 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6670 fprintf_unfiltered (gdb_stdlog
,
6671 "infrun: stepped permanent breakpoint, stopped in "
6673 delete_step_resume_breakpoint (ecs
->event_thread
);
6674 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6678 /* We come here if we hit a breakpoint but should not stop for it.
6679 Possibly we also were stepping and should stop for that. So fall
6680 through and test for stepping. But, if not stepping, do not
6683 /* In all-stop mode, if we're currently stepping but have stopped in
6684 some other thread, we need to switch back to the stepped thread. */
6685 if (switch_back_to_stepped_thread (ecs
))
6688 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6691 fprintf_unfiltered (gdb_stdlog
,
6692 "infrun: step-resume breakpoint is inserted\n");
6694 /* Having a step-resume breakpoint overrides anything
6695 else having to do with stepping commands until
6696 that breakpoint is reached. */
6701 if (ecs
->event_thread
->control
.step_range_end
== 0)
6704 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6705 /* Likewise if we aren't even stepping. */
6710 /* Re-fetch current thread's frame in case the code above caused
6711 the frame cache to be re-initialized, making our FRAME variable
6712 a dangling pointer. */
6713 frame
= get_current_frame ();
6714 gdbarch
= get_frame_arch (frame
);
6715 fill_in_stop_func (gdbarch
, ecs
);
6717 /* If stepping through a line, keep going if still within it.
6719 Note that step_range_end is the address of the first instruction
6720 beyond the step range, and NOT the address of the last instruction
6723 Note also that during reverse execution, we may be stepping
6724 through a function epilogue and therefore must detect when
6725 the current-frame changes in the middle of a line. */
6727 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6729 && (execution_direction
!= EXEC_REVERSE
6730 || frame_id_eq (get_frame_id (frame
),
6731 ecs
->event_thread
->control
.step_frame_id
)))
6735 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6736 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6737 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6739 /* Tentatively re-enable range stepping; `resume' disables it if
6740 necessary (e.g., if we're stepping over a breakpoint or we
6741 have software watchpoints). */
6742 ecs
->event_thread
->control
.may_range_step
= 1;
6744 /* When stepping backward, stop at beginning of line range
6745 (unless it's the function entry point, in which case
6746 keep going back to the call point). */
6747 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6748 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6749 && stop_pc
!= ecs
->stop_func_start
6750 && execution_direction
== EXEC_REVERSE
)
6751 end_stepping_range (ecs
);
6758 /* We stepped out of the stepping range. */
6760 /* If we are stepping at the source level and entered the runtime
6761 loader dynamic symbol resolution code...
6763 EXEC_FORWARD: we keep on single stepping until we exit the run
6764 time loader code and reach the callee's address.
6766 EXEC_REVERSE: we've already executed the callee (backward), and
6767 the runtime loader code is handled just like any other
6768 undebuggable function call. Now we need only keep stepping
6769 backward through the trampoline code, and that's handled further
6770 down, so there is nothing for us to do here. */
6772 if (execution_direction
!= EXEC_REVERSE
6773 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6774 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6776 CORE_ADDR pc_after_resolver
=
6777 gdbarch_skip_solib_resolver (gdbarch
,
6778 ecs
->event_thread
->suspend
.stop_pc
);
6781 fprintf_unfiltered (gdb_stdlog
,
6782 "infrun: stepped into dynsym resolve code\n");
6784 if (pc_after_resolver
)
6786 /* Set up a step-resume breakpoint at the address
6787 indicated by SKIP_SOLIB_RESOLVER. */
6788 symtab_and_line sr_sal
;
6789 sr_sal
.pc
= pc_after_resolver
;
6790 sr_sal
.pspace
= get_frame_program_space (frame
);
6792 insert_step_resume_breakpoint_at_sal (gdbarch
,
6793 sr_sal
, null_frame_id
);
6800 /* Step through an indirect branch thunk. */
6801 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6802 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6803 ecs
->event_thread
->suspend
.stop_pc
))
6806 fprintf_unfiltered (gdb_stdlog
,
6807 "infrun: stepped into indirect branch thunk\n");
6812 if (ecs
->event_thread
->control
.step_range_end
!= 1
6813 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6814 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6815 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6818 fprintf_unfiltered (gdb_stdlog
,
6819 "infrun: stepped into signal trampoline\n");
6820 /* The inferior, while doing a "step" or "next", has ended up in
6821 a signal trampoline (either by a signal being delivered or by
6822 the signal handler returning). Just single-step until the
6823 inferior leaves the trampoline (either by calling the handler
6829 /* If we're in the return path from a shared library trampoline,
6830 we want to proceed through the trampoline when stepping. */
6831 /* macro/2012-04-25: This needs to come before the subroutine
6832 call check below as on some targets return trampolines look
6833 like subroutine calls (MIPS16 return thunks). */
6834 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6835 ecs
->event_thread
->suspend
.stop_pc
,
6836 ecs
->stop_func_name
)
6837 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6839 /* Determine where this trampoline returns. */
6840 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6841 CORE_ADDR real_stop_pc
6842 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6845 fprintf_unfiltered (gdb_stdlog
,
6846 "infrun: stepped into solib return tramp\n");
6848 /* Only proceed through if we know where it's going. */
6851 /* And put the step-breakpoint there and go until there. */
6852 symtab_and_line sr_sal
;
6853 sr_sal
.pc
= real_stop_pc
;
6854 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6855 sr_sal
.pspace
= get_frame_program_space (frame
);
6857 /* Do not specify what the fp should be when we stop since
6858 on some machines the prologue is where the new fp value
6860 insert_step_resume_breakpoint_at_sal (gdbarch
,
6861 sr_sal
, null_frame_id
);
6863 /* Restart without fiddling with the step ranges or
6870 /* Check for subroutine calls. The check for the current frame
6871 equalling the step ID is not necessary - the check of the
6872 previous frame's ID is sufficient - but it is a common case and
6873 cheaper than checking the previous frame's ID.
6875 NOTE: frame_id_eq will never report two invalid frame IDs as
6876 being equal, so to get into this block, both the current and
6877 previous frame must have valid frame IDs. */
6878 /* The outer_frame_id check is a heuristic to detect stepping
6879 through startup code. If we step over an instruction which
6880 sets the stack pointer from an invalid value to a valid value,
6881 we may detect that as a subroutine call from the mythical
6882 "outermost" function. This could be fixed by marking
6883 outermost frames as !stack_p,code_p,special_p. Then the
6884 initial outermost frame, before sp was valid, would
6885 have code_addr == &_start. See the comment in frame_id_eq
6887 if (!frame_id_eq (get_stack_frame_id (frame
),
6888 ecs
->event_thread
->control
.step_stack_frame_id
)
6889 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6890 ecs
->event_thread
->control
.step_stack_frame_id
)
6891 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6893 || (ecs
->event_thread
->control
.step_start_function
6894 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6896 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6897 CORE_ADDR real_stop_pc
;
6900 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6902 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6904 /* I presume that step_over_calls is only 0 when we're
6905 supposed to be stepping at the assembly language level
6906 ("stepi"). Just stop. */
6907 /* And this works the same backward as frontward. MVS */
6908 end_stepping_range (ecs
);
6912 /* Reverse stepping through solib trampolines. */
6914 if (execution_direction
== EXEC_REVERSE
6915 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6916 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6917 || (ecs
->stop_func_start
== 0
6918 && in_solib_dynsym_resolve_code (stop_pc
))))
6920 /* Any solib trampoline code can be handled in reverse
6921 by simply continuing to single-step. We have already
6922 executed the solib function (backwards), and a few
6923 steps will take us back through the trampoline to the
6929 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6931 /* We're doing a "next".
6933 Normal (forward) execution: set a breakpoint at the
6934 callee's return address (the address at which the caller
6937 Reverse (backward) execution. set the step-resume
6938 breakpoint at the start of the function that we just
6939 stepped into (backwards), and continue to there. When we
6940 get there, we'll need to single-step back to the caller. */
6942 if (execution_direction
== EXEC_REVERSE
)
6944 /* If we're already at the start of the function, we've either
6945 just stepped backward into a single instruction function,
6946 or stepped back out of a signal handler to the first instruction
6947 of the function. Just keep going, which will single-step back
6949 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6951 /* Normal function call return (static or dynamic). */
6952 symtab_and_line sr_sal
;
6953 sr_sal
.pc
= ecs
->stop_func_start
;
6954 sr_sal
.pspace
= get_frame_program_space (frame
);
6955 insert_step_resume_breakpoint_at_sal (gdbarch
,
6956 sr_sal
, null_frame_id
);
6960 insert_step_resume_breakpoint_at_caller (frame
);
6966 /* If we are in a function call trampoline (a stub between the
6967 calling routine and the real function), locate the real
6968 function. That's what tells us (a) whether we want to step
6969 into it at all, and (b) what prologue we want to run to the
6970 end of, if we do step into it. */
6971 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6972 if (real_stop_pc
== 0)
6973 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6974 if (real_stop_pc
!= 0)
6975 ecs
->stop_func_start
= real_stop_pc
;
6977 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6979 symtab_and_line sr_sal
;
6980 sr_sal
.pc
= ecs
->stop_func_start
;
6981 sr_sal
.pspace
= get_frame_program_space (frame
);
6983 insert_step_resume_breakpoint_at_sal (gdbarch
,
6984 sr_sal
, null_frame_id
);
6989 /* If we have line number information for the function we are
6990 thinking of stepping into and the function isn't on the skip
6993 If there are several symtabs at that PC (e.g. with include
6994 files), just want to know whether *any* of them have line
6995 numbers. find_pc_line handles this. */
6997 struct symtab_and_line tmp_sal
;
6999 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7000 if (tmp_sal
.line
!= 0
7001 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
7003 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
7005 if (execution_direction
== EXEC_REVERSE
)
7006 handle_step_into_function_backward (gdbarch
, ecs
);
7008 handle_step_into_function (gdbarch
, ecs
);
7013 /* If we have no line number and the step-stop-if-no-debug is
7014 set, we stop the step so that the user has a chance to switch
7015 in assembly mode. */
7016 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7017 && step_stop_if_no_debug
)
7019 end_stepping_range (ecs
);
7023 if (execution_direction
== EXEC_REVERSE
)
7025 /* If we're already at the start of the function, we've either just
7026 stepped backward into a single instruction function without line
7027 number info, or stepped back out of a signal handler to the first
7028 instruction of the function without line number info. Just keep
7029 going, which will single-step back to the caller. */
7030 if (ecs
->stop_func_start
!= stop_pc
)
7032 /* Set a breakpoint at callee's start address.
7033 From there we can step once and be back in the caller. */
7034 symtab_and_line sr_sal
;
7035 sr_sal
.pc
= ecs
->stop_func_start
;
7036 sr_sal
.pspace
= get_frame_program_space (frame
);
7037 insert_step_resume_breakpoint_at_sal (gdbarch
,
7038 sr_sal
, null_frame_id
);
7042 /* Set a breakpoint at callee's return address (the address
7043 at which the caller will resume). */
7044 insert_step_resume_breakpoint_at_caller (frame
);
7050 /* Reverse stepping through solib trampolines. */
7052 if (execution_direction
== EXEC_REVERSE
7053 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7055 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7057 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7058 || (ecs
->stop_func_start
== 0
7059 && in_solib_dynsym_resolve_code (stop_pc
)))
7061 /* Any solib trampoline code can be handled in reverse
7062 by simply continuing to single-step. We have already
7063 executed the solib function (backwards), and a few
7064 steps will take us back through the trampoline to the
7069 else if (in_solib_dynsym_resolve_code (stop_pc
))
7071 /* Stepped backward into the solib dynsym resolver.
7072 Set a breakpoint at its start and continue, then
7073 one more step will take us out. */
7074 symtab_and_line sr_sal
;
7075 sr_sal
.pc
= ecs
->stop_func_start
;
7076 sr_sal
.pspace
= get_frame_program_space (frame
);
7077 insert_step_resume_breakpoint_at_sal (gdbarch
,
7078 sr_sal
, null_frame_id
);
7084 /* This always returns the sal for the inner-most frame when we are in a
7085 stack of inlined frames, even if GDB actually believes that it is in a
7086 more outer frame. This is checked for below by calls to
7087 inline_skipped_frames. */
7088 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7090 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7091 the trampoline processing logic, however, there are some trampolines
7092 that have no names, so we should do trampoline handling first. */
7093 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7094 && ecs
->stop_func_name
== NULL
7095 && stop_pc_sal
.line
== 0)
7098 fprintf_unfiltered (gdb_stdlog
,
7099 "infrun: stepped into undebuggable function\n");
7101 /* The inferior just stepped into, or returned to, an
7102 undebuggable function (where there is no debugging information
7103 and no line number corresponding to the address where the
7104 inferior stopped). Since we want to skip this kind of code,
7105 we keep going until the inferior returns from this
7106 function - unless the user has asked us not to (via
7107 set step-mode) or we no longer know how to get back
7108 to the call site. */
7109 if (step_stop_if_no_debug
7110 || !frame_id_p (frame_unwind_caller_id (frame
)))
7112 /* If we have no line number and the step-stop-if-no-debug
7113 is set, we stop the step so that the user has a chance to
7114 switch in assembly mode. */
7115 end_stepping_range (ecs
);
7120 /* Set a breakpoint at callee's return address (the address
7121 at which the caller will resume). */
7122 insert_step_resume_breakpoint_at_caller (frame
);
7128 if (ecs
->event_thread
->control
.step_range_end
== 1)
7130 /* It is stepi or nexti. We always want to stop stepping after
7133 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7134 end_stepping_range (ecs
);
7138 if (stop_pc_sal
.line
== 0)
7140 /* We have no line number information. That means to stop
7141 stepping (does this always happen right after one instruction,
7142 when we do "s" in a function with no line numbers,
7143 or can this happen as a result of a return or longjmp?). */
7145 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7146 end_stepping_range (ecs
);
7150 /* Look for "calls" to inlined functions, part one. If the inline
7151 frame machinery detected some skipped call sites, we have entered
7152 a new inline function. */
7154 if (frame_id_eq (get_frame_id (get_current_frame ()),
7155 ecs
->event_thread
->control
.step_frame_id
)
7156 && inline_skipped_frames (ecs
->event_thread
))
7159 fprintf_unfiltered (gdb_stdlog
,
7160 "infrun: stepped into inlined function\n");
7162 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7164 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7166 /* For "step", we're going to stop. But if the call site
7167 for this inlined function is on the same source line as
7168 we were previously stepping, go down into the function
7169 first. Otherwise stop at the call site. */
7171 if (call_sal
.line
== ecs
->event_thread
->current_line
7172 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7174 step_into_inline_frame (ecs
->event_thread
);
7175 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7182 end_stepping_range (ecs
);
7187 /* For "next", we should stop at the call site if it is on a
7188 different source line. Otherwise continue through the
7189 inlined function. */
7190 if (call_sal
.line
== ecs
->event_thread
->current_line
7191 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7194 end_stepping_range (ecs
);
7199 /* Look for "calls" to inlined functions, part two. If we are still
7200 in the same real function we were stepping through, but we have
7201 to go further up to find the exact frame ID, we are stepping
7202 through a more inlined call beyond its call site. */
7204 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7205 && !frame_id_eq (get_frame_id (get_current_frame ()),
7206 ecs
->event_thread
->control
.step_frame_id
)
7207 && stepped_in_from (get_current_frame (),
7208 ecs
->event_thread
->control
.step_frame_id
))
7211 fprintf_unfiltered (gdb_stdlog
,
7212 "infrun: stepping through inlined function\n");
7214 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7215 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7218 end_stepping_range (ecs
);
7222 bool refresh_step_info
= true;
7223 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7224 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7225 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7227 if (stop_pc_sal
.is_stmt
)
7229 /* We are at the start of a different line. So stop. Note that
7230 we don't stop if we step into the middle of a different line.
7231 That is said to make things like for (;;) statements work
7234 fprintf_unfiltered (gdb_stdlog
,
7235 "infrun: stepped to a different line\n");
7236 end_stepping_range (ecs
);
7239 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7240 ecs
->event_thread
->control
.step_frame_id
))
7242 /* We are at the start of a different line, however, this line is
7243 not marked as a statement, and we have not changed frame. We
7244 ignore this line table entry, and continue stepping forward,
7245 looking for a better place to stop. */
7246 refresh_step_info
= false;
7248 fprintf_unfiltered (gdb_stdlog
,
7249 "infrun: stepped to a different line, but "
7250 "it's not the start of a statement\n");
7254 /* We aren't done stepping.
7256 Optimize by setting the stepping range to the line.
7257 (We might not be in the original line, but if we entered a
7258 new line in mid-statement, we continue stepping. This makes
7259 things like for(;;) statements work better.)
7261 If we entered a SAL that indicates a non-statement line table entry,
7262 then we update the stepping range, but we don't update the step info,
7263 which includes things like the line number we are stepping away from.
7264 This means we will stop when we find a line table entry that is marked
7265 as is-statement, even if it matches the non-statement one we just
7268 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7269 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7270 ecs
->event_thread
->control
.may_range_step
= 1;
7271 if (refresh_step_info
)
7272 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7275 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7279 /* In all-stop mode, if we're currently stepping but have stopped in
7280 some other thread, we may need to switch back to the stepped
7281 thread. Returns true we set the inferior running, false if we left
7282 it stopped (and the event needs further processing). */
7285 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7287 if (!target_is_non_stop_p ())
7289 struct thread_info
*stepping_thread
;
7291 /* If any thread is blocked on some internal breakpoint, and we
7292 simply need to step over that breakpoint to get it going
7293 again, do that first. */
7295 /* However, if we see an event for the stepping thread, then we
7296 know all other threads have been moved past their breakpoints
7297 already. Let the caller check whether the step is finished,
7298 etc., before deciding to move it past a breakpoint. */
7299 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7302 /* Check if the current thread is blocked on an incomplete
7303 step-over, interrupted by a random signal. */
7304 if (ecs
->event_thread
->control
.trap_expected
7305 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7309 fprintf_unfiltered (gdb_stdlog
,
7310 "infrun: need to finish step-over of [%s]\n",
7311 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7317 /* Check if the current thread is blocked by a single-step
7318 breakpoint of another thread. */
7319 if (ecs
->hit_singlestep_breakpoint
)
7323 fprintf_unfiltered (gdb_stdlog
,
7324 "infrun: need to step [%s] over single-step "
7326 target_pid_to_str (ecs
->ptid
).c_str ());
7332 /* If this thread needs yet another step-over (e.g., stepping
7333 through a delay slot), do it first before moving on to
7335 if (thread_still_needs_step_over (ecs
->event_thread
))
7339 fprintf_unfiltered (gdb_stdlog
,
7340 "infrun: thread [%s] still needs step-over\n",
7341 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7347 /* If scheduler locking applies even if not stepping, there's no
7348 need to walk over threads. Above we've checked whether the
7349 current thread is stepping. If some other thread not the
7350 event thread is stepping, then it must be that scheduler
7351 locking is not in effect. */
7352 if (schedlock_applies (ecs
->event_thread
))
7355 /* Otherwise, we no longer expect a trap in the current thread.
7356 Clear the trap_expected flag before switching back -- this is
7357 what keep_going does as well, if we call it. */
7358 ecs
->event_thread
->control
.trap_expected
= 0;
7360 /* Likewise, clear the signal if it should not be passed. */
7361 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7362 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7364 /* Do all pending step-overs before actually proceeding with
7366 if (start_step_over ())
7368 prepare_to_wait (ecs
);
7372 /* Look for the stepping/nexting thread. */
7373 stepping_thread
= NULL
;
7375 for (thread_info
*tp
: all_non_exited_threads ())
7377 switch_to_thread_no_regs (tp
);
7379 /* Ignore threads of processes the caller is not
7382 && (tp
->inf
->process_target () != ecs
->target
7383 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7386 /* When stepping over a breakpoint, we lock all threads
7387 except the one that needs to move past the breakpoint.
7388 If a non-event thread has this set, the "incomplete
7389 step-over" check above should have caught it earlier. */
7390 if (tp
->control
.trap_expected
)
7392 internal_error (__FILE__
, __LINE__
,
7393 "[%s] has inconsistent state: "
7394 "trap_expected=%d\n",
7395 target_pid_to_str (tp
->ptid
).c_str (),
7396 tp
->control
.trap_expected
);
7399 /* Did we find the stepping thread? */
7400 if (tp
->control
.step_range_end
)
7402 /* Yep. There should only one though. */
7403 gdb_assert (stepping_thread
== NULL
);
7405 /* The event thread is handled at the top, before we
7407 gdb_assert (tp
!= ecs
->event_thread
);
7409 /* If some thread other than the event thread is
7410 stepping, then scheduler locking can't be in effect,
7411 otherwise we wouldn't have resumed the current event
7412 thread in the first place. */
7413 gdb_assert (!schedlock_applies (tp
));
7415 stepping_thread
= tp
;
7419 if (stepping_thread
!= NULL
)
7422 fprintf_unfiltered (gdb_stdlog
,
7423 "infrun: switching back to stepped thread\n");
7425 if (keep_going_stepped_thread (stepping_thread
))
7427 prepare_to_wait (ecs
);
7432 switch_to_thread (ecs
->event_thread
);
7438 /* Set a previously stepped thread back to stepping. Returns true on
7439 success, false if the resume is not possible (e.g., the thread
7443 keep_going_stepped_thread (struct thread_info
*tp
)
7445 struct frame_info
*frame
;
7446 struct execution_control_state ecss
;
7447 struct execution_control_state
*ecs
= &ecss
;
7449 /* If the stepping thread exited, then don't try to switch back and
7450 resume it, which could fail in several different ways depending
7451 on the target. Instead, just keep going.
7453 We can find a stepping dead thread in the thread list in two
7456 - The target supports thread exit events, and when the target
7457 tries to delete the thread from the thread list, inferior_ptid
7458 pointed at the exiting thread. In such case, calling
7459 delete_thread does not really remove the thread from the list;
7460 instead, the thread is left listed, with 'exited' state.
7462 - The target's debug interface does not support thread exit
7463 events, and so we have no idea whatsoever if the previously
7464 stepping thread is still alive. For that reason, we need to
7465 synchronously query the target now. */
7467 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7470 fprintf_unfiltered (gdb_stdlog
,
7471 "infrun: not resuming previously "
7472 "stepped thread, it has vanished\n");
7479 fprintf_unfiltered (gdb_stdlog
,
7480 "infrun: resuming previously stepped thread\n");
7482 reset_ecs (ecs
, tp
);
7483 switch_to_thread (tp
);
7485 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7486 frame
= get_current_frame ();
7488 /* If the PC of the thread we were trying to single-step has
7489 changed, then that thread has trapped or been signaled, but the
7490 event has not been reported to GDB yet. Re-poll the target
7491 looking for this particular thread's event (i.e. temporarily
7492 enable schedlock) by:
7494 - setting a break at the current PC
7495 - resuming that particular thread, only (by setting trap
7498 This prevents us continuously moving the single-step breakpoint
7499 forward, one instruction at a time, overstepping. */
7501 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7506 fprintf_unfiltered (gdb_stdlog
,
7507 "infrun: expected thread advanced also (%s -> %s)\n",
7508 paddress (target_gdbarch (), tp
->prev_pc
),
7509 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7511 /* Clear the info of the previous step-over, as it's no longer
7512 valid (if the thread was trying to step over a breakpoint, it
7513 has already succeeded). It's what keep_going would do too,
7514 if we called it. Do this before trying to insert the sss
7515 breakpoint, otherwise if we were previously trying to step
7516 over this exact address in another thread, the breakpoint is
7518 clear_step_over_info ();
7519 tp
->control
.trap_expected
= 0;
7521 insert_single_step_breakpoint (get_frame_arch (frame
),
7522 get_frame_address_space (frame
),
7523 tp
->suspend
.stop_pc
);
7526 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7527 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7532 fprintf_unfiltered (gdb_stdlog
,
7533 "infrun: expected thread still hasn't advanced\n");
7535 keep_going_pass_signal (ecs
);
7540 /* Is thread TP in the middle of (software or hardware)
7541 single-stepping? (Note the result of this function must never be
7542 passed directly as target_resume's STEP parameter.) */
7545 currently_stepping (struct thread_info
*tp
)
7547 return ((tp
->control
.step_range_end
7548 && tp
->control
.step_resume_breakpoint
== NULL
)
7549 || tp
->control
.trap_expected
7550 || tp
->stepped_breakpoint
7551 || bpstat_should_step ());
7554 /* Inferior has stepped into a subroutine call with source code that
7555 we should not step over. Do step to the first line of code in
7559 handle_step_into_function (struct gdbarch
*gdbarch
,
7560 struct execution_control_state
*ecs
)
7562 fill_in_stop_func (gdbarch
, ecs
);
7564 compunit_symtab
*cust
7565 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7566 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7567 ecs
->stop_func_start
7568 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7570 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7571 /* Use the step_resume_break to step until the end of the prologue,
7572 even if that involves jumps (as it seems to on the vax under
7574 /* If the prologue ends in the middle of a source line, continue to
7575 the end of that source line (if it is still within the function).
7576 Otherwise, just go to end of prologue. */
7577 if (stop_func_sal
.end
7578 && stop_func_sal
.pc
!= ecs
->stop_func_start
7579 && stop_func_sal
.end
< ecs
->stop_func_end
)
7580 ecs
->stop_func_start
= stop_func_sal
.end
;
7582 /* Architectures which require breakpoint adjustment might not be able
7583 to place a breakpoint at the computed address. If so, the test
7584 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7585 ecs->stop_func_start to an address at which a breakpoint may be
7586 legitimately placed.
7588 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7589 made, GDB will enter an infinite loop when stepping through
7590 optimized code consisting of VLIW instructions which contain
7591 subinstructions corresponding to different source lines. On
7592 FR-V, it's not permitted to place a breakpoint on any but the
7593 first subinstruction of a VLIW instruction. When a breakpoint is
7594 set, GDB will adjust the breakpoint address to the beginning of
7595 the VLIW instruction. Thus, we need to make the corresponding
7596 adjustment here when computing the stop address. */
7598 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7600 ecs
->stop_func_start
7601 = gdbarch_adjust_breakpoint_address (gdbarch
,
7602 ecs
->stop_func_start
);
7605 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7607 /* We are already there: stop now. */
7608 end_stepping_range (ecs
);
7613 /* Put the step-breakpoint there and go until there. */
7614 symtab_and_line sr_sal
;
7615 sr_sal
.pc
= ecs
->stop_func_start
;
7616 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7617 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7619 /* Do not specify what the fp should be when we stop since on
7620 some machines the prologue is where the new fp value is
7622 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7624 /* And make sure stepping stops right away then. */
7625 ecs
->event_thread
->control
.step_range_end
7626 = ecs
->event_thread
->control
.step_range_start
;
7631 /* Inferior has stepped backward into a subroutine call with source
7632 code that we should not step over. Do step to the beginning of the
7633 last line of code in it. */
7636 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7637 struct execution_control_state
*ecs
)
7639 struct compunit_symtab
*cust
;
7640 struct symtab_and_line stop_func_sal
;
7642 fill_in_stop_func (gdbarch
, ecs
);
7644 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7645 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7646 ecs
->stop_func_start
7647 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7649 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7651 /* OK, we're just going to keep stepping here. */
7652 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7654 /* We're there already. Just stop stepping now. */
7655 end_stepping_range (ecs
);
7659 /* Else just reset the step range and keep going.
7660 No step-resume breakpoint, they don't work for
7661 epilogues, which can have multiple entry paths. */
7662 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7663 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7669 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7670 This is used to both functions and to skip over code. */
7673 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7674 struct symtab_and_line sr_sal
,
7675 struct frame_id sr_id
,
7676 enum bptype sr_type
)
7678 /* There should never be more than one step-resume or longjmp-resume
7679 breakpoint per thread, so we should never be setting a new
7680 step_resume_breakpoint when one is already active. */
7681 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7682 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7685 fprintf_unfiltered (gdb_stdlog
,
7686 "infrun: inserting step-resume breakpoint at %s\n",
7687 paddress (gdbarch
, sr_sal
.pc
));
7689 inferior_thread ()->control
.step_resume_breakpoint
7690 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7694 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7695 struct symtab_and_line sr_sal
,
7696 struct frame_id sr_id
)
7698 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7703 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7704 This is used to skip a potential signal handler.
7706 This is called with the interrupted function's frame. The signal
7707 handler, when it returns, will resume the interrupted function at
7711 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7713 gdb_assert (return_frame
!= NULL
);
7715 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7717 symtab_and_line sr_sal
;
7718 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7719 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7720 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7722 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7723 get_stack_frame_id (return_frame
),
7727 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7728 is used to skip a function after stepping into it (for "next" or if
7729 the called function has no debugging information).
7731 The current function has almost always been reached by single
7732 stepping a call or return instruction. NEXT_FRAME belongs to the
7733 current function, and the breakpoint will be set at the caller's
7736 This is a separate function rather than reusing
7737 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7738 get_prev_frame, which may stop prematurely (see the implementation
7739 of frame_unwind_caller_id for an example). */
7742 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7744 /* We shouldn't have gotten here if we don't know where the call site
7746 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7748 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7750 symtab_and_line sr_sal
;
7751 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7752 frame_unwind_caller_pc (next_frame
));
7753 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7754 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7756 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7757 frame_unwind_caller_id (next_frame
));
7760 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7761 new breakpoint at the target of a jmp_buf. The handling of
7762 longjmp-resume uses the same mechanisms used for handling
7763 "step-resume" breakpoints. */
7766 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7768 /* There should never be more than one longjmp-resume breakpoint per
7769 thread, so we should never be setting a new
7770 longjmp_resume_breakpoint when one is already active. */
7771 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7774 fprintf_unfiltered (gdb_stdlog
,
7775 "infrun: inserting longjmp-resume breakpoint at %s\n",
7776 paddress (gdbarch
, pc
));
7778 inferior_thread ()->control
.exception_resume_breakpoint
=
7779 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7782 /* Insert an exception resume breakpoint. TP is the thread throwing
7783 the exception. The block B is the block of the unwinder debug hook
7784 function. FRAME is the frame corresponding to the call to this
7785 function. SYM is the symbol of the function argument holding the
7786 target PC of the exception. */
7789 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7790 const struct block
*b
,
7791 struct frame_info
*frame
,
7796 struct block_symbol vsym
;
7797 struct value
*value
;
7799 struct breakpoint
*bp
;
7801 vsym
= lookup_symbol_search_name (sym
->search_name (),
7803 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7804 /* If the value was optimized out, revert to the old behavior. */
7805 if (! value_optimized_out (value
))
7807 handler
= value_as_address (value
);
7810 fprintf_unfiltered (gdb_stdlog
,
7811 "infrun: exception resume at %lx\n",
7812 (unsigned long) handler
);
7814 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7816 bp_exception_resume
).release ();
7818 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7821 bp
->thread
= tp
->global_num
;
7822 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7825 catch (const gdb_exception_error
&e
)
7827 /* We want to ignore errors here. */
7831 /* A helper for check_exception_resume that sets an
7832 exception-breakpoint based on a SystemTap probe. */
7835 insert_exception_resume_from_probe (struct thread_info
*tp
,
7836 const struct bound_probe
*probe
,
7837 struct frame_info
*frame
)
7839 struct value
*arg_value
;
7841 struct breakpoint
*bp
;
7843 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7847 handler
= value_as_address (arg_value
);
7850 fprintf_unfiltered (gdb_stdlog
,
7851 "infrun: exception resume at %s\n",
7852 paddress (probe
->objfile
->arch (),
7855 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7856 handler
, bp_exception_resume
).release ();
7857 bp
->thread
= tp
->global_num
;
7858 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7861 /* This is called when an exception has been intercepted. Check to
7862 see whether the exception's destination is of interest, and if so,
7863 set an exception resume breakpoint there. */
7866 check_exception_resume (struct execution_control_state
*ecs
,
7867 struct frame_info
*frame
)
7869 struct bound_probe probe
;
7870 struct symbol
*func
;
7872 /* First see if this exception unwinding breakpoint was set via a
7873 SystemTap probe point. If so, the probe has two arguments: the
7874 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7875 set a breakpoint there. */
7876 probe
= find_probe_by_pc (get_frame_pc (frame
));
7879 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7883 func
= get_frame_function (frame
);
7889 const struct block
*b
;
7890 struct block_iterator iter
;
7894 /* The exception breakpoint is a thread-specific breakpoint on
7895 the unwinder's debug hook, declared as:
7897 void _Unwind_DebugHook (void *cfa, void *handler);
7899 The CFA argument indicates the frame to which control is
7900 about to be transferred. HANDLER is the destination PC.
7902 We ignore the CFA and set a temporary breakpoint at HANDLER.
7903 This is not extremely efficient but it avoids issues in gdb
7904 with computing the DWARF CFA, and it also works even in weird
7905 cases such as throwing an exception from inside a signal
7908 b
= SYMBOL_BLOCK_VALUE (func
);
7909 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7911 if (!SYMBOL_IS_ARGUMENT (sym
))
7918 insert_exception_resume_breakpoint (ecs
->event_thread
,
7924 catch (const gdb_exception_error
&e
)
7930 stop_waiting (struct execution_control_state
*ecs
)
7933 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7935 /* Let callers know we don't want to wait for the inferior anymore. */
7936 ecs
->wait_some_more
= 0;
7938 /* If all-stop, but there exists a non-stop target, stop all
7939 threads now that we're presenting the stop to the user. */
7940 if (!non_stop
&& exists_non_stop_target ())
7941 stop_all_threads ();
7944 /* Like keep_going, but passes the signal to the inferior, even if the
7945 signal is set to nopass. */
7948 keep_going_pass_signal (struct execution_control_state
*ecs
)
7950 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7951 gdb_assert (!ecs
->event_thread
->resumed
);
7953 /* Save the pc before execution, to compare with pc after stop. */
7954 ecs
->event_thread
->prev_pc
7955 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7957 if (ecs
->event_thread
->control
.trap_expected
)
7959 struct thread_info
*tp
= ecs
->event_thread
;
7962 fprintf_unfiltered (gdb_stdlog
,
7963 "infrun: %s has trap_expected set, "
7964 "resuming to collect trap\n",
7965 target_pid_to_str (tp
->ptid
).c_str ());
7967 /* We haven't yet gotten our trap, and either: intercepted a
7968 non-signal event (e.g., a fork); or took a signal which we
7969 are supposed to pass through to the inferior. Simply
7971 resume (ecs
->event_thread
->suspend
.stop_signal
);
7973 else if (step_over_info_valid_p ())
7975 /* Another thread is stepping over a breakpoint in-line. If
7976 this thread needs a step-over too, queue the request. In
7977 either case, this resume must be deferred for later. */
7978 struct thread_info
*tp
= ecs
->event_thread
;
7980 if (ecs
->hit_singlestep_breakpoint
7981 || thread_still_needs_step_over (tp
))
7984 fprintf_unfiltered (gdb_stdlog
,
7985 "infrun: step-over already in progress: "
7986 "step-over for %s deferred\n",
7987 target_pid_to_str (tp
->ptid
).c_str ());
7988 thread_step_over_chain_enqueue (tp
);
7993 fprintf_unfiltered (gdb_stdlog
,
7994 "infrun: step-over in progress: "
7995 "resume of %s deferred\n",
7996 target_pid_to_str (tp
->ptid
).c_str ());
8001 struct regcache
*regcache
= get_current_regcache ();
8004 step_over_what step_what
;
8006 /* Either the trap was not expected, but we are continuing
8007 anyway (if we got a signal, the user asked it be passed to
8010 We got our expected trap, but decided we should resume from
8013 We're going to run this baby now!
8015 Note that insert_breakpoints won't try to re-insert
8016 already inserted breakpoints. Therefore, we don't
8017 care if breakpoints were already inserted, or not. */
8019 /* If we need to step over a breakpoint, and we're not using
8020 displaced stepping to do so, insert all breakpoints
8021 (watchpoints, etc.) but the one we're stepping over, step one
8022 instruction, and then re-insert the breakpoint when that step
8025 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
8027 remove_bp
= (ecs
->hit_singlestep_breakpoint
8028 || (step_what
& STEP_OVER_BREAKPOINT
));
8029 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
8031 /* We can't use displaced stepping if we need to step past a
8032 watchpoint. The instruction copied to the scratch pad would
8033 still trigger the watchpoint. */
8035 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8037 set_step_over_info (regcache
->aspace (),
8038 regcache_read_pc (regcache
), remove_wps
,
8039 ecs
->event_thread
->global_num
);
8041 else if (remove_wps
)
8042 set_step_over_info (NULL
, 0, remove_wps
, -1);
8044 /* If we now need to do an in-line step-over, we need to stop
8045 all other threads. Note this must be done before
8046 insert_breakpoints below, because that removes the breakpoint
8047 we're about to step over, otherwise other threads could miss
8049 if (step_over_info_valid_p () && target_is_non_stop_p ())
8050 stop_all_threads ();
8052 /* Stop stepping if inserting breakpoints fails. */
8055 insert_breakpoints ();
8057 catch (const gdb_exception_error
&e
)
8059 exception_print (gdb_stderr
, e
);
8061 clear_step_over_info ();
8065 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8067 resume (ecs
->event_thread
->suspend
.stop_signal
);
8070 prepare_to_wait (ecs
);
8073 /* Called when we should continue running the inferior, because the
8074 current event doesn't cause a user visible stop. This does the
8075 resuming part; waiting for the next event is done elsewhere. */
8078 keep_going (struct execution_control_state
*ecs
)
8080 if (ecs
->event_thread
->control
.trap_expected
8081 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8082 ecs
->event_thread
->control
.trap_expected
= 0;
8084 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8085 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8086 keep_going_pass_signal (ecs
);
8089 /* This function normally comes after a resume, before
8090 handle_inferior_event exits. It takes care of any last bits of
8091 housekeeping, and sets the all-important wait_some_more flag. */
8094 prepare_to_wait (struct execution_control_state
*ecs
)
8097 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
8099 ecs
->wait_some_more
= 1;
8101 if (!target_is_async_p ())
8102 mark_infrun_async_event_handler ();
8105 /* We are done with the step range of a step/next/si/ni command.
8106 Called once for each n of a "step n" operation. */
8109 end_stepping_range (struct execution_control_state
*ecs
)
8111 ecs
->event_thread
->control
.stop_step
= 1;
8115 /* Several print_*_reason functions to print why the inferior has stopped.
8116 We always print something when the inferior exits, or receives a signal.
8117 The rest of the cases are dealt with later on in normal_stop and
8118 print_it_typical. Ideally there should be a call to one of these
8119 print_*_reason functions functions from handle_inferior_event each time
8120 stop_waiting is called.
8122 Note that we don't call these directly, instead we delegate that to
8123 the interpreters, through observers. Interpreters then call these
8124 with whatever uiout is right. */
8127 print_end_stepping_range_reason (struct ui_out
*uiout
)
8129 /* For CLI-like interpreters, print nothing. */
8131 if (uiout
->is_mi_like_p ())
8133 uiout
->field_string ("reason",
8134 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8139 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8141 annotate_signalled ();
8142 if (uiout
->is_mi_like_p ())
8144 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8145 uiout
->text ("\nProgram terminated with signal ");
8146 annotate_signal_name ();
8147 uiout
->field_string ("signal-name",
8148 gdb_signal_to_name (siggnal
));
8149 annotate_signal_name_end ();
8151 annotate_signal_string ();
8152 uiout
->field_string ("signal-meaning",
8153 gdb_signal_to_string (siggnal
));
8154 annotate_signal_string_end ();
8155 uiout
->text (".\n");
8156 uiout
->text ("The program no longer exists.\n");
8160 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8162 struct inferior
*inf
= current_inferior ();
8163 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8165 annotate_exited (exitstatus
);
8168 if (uiout
->is_mi_like_p ())
8169 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8170 std::string exit_code_str
8171 = string_printf ("0%o", (unsigned int) exitstatus
);
8172 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8173 plongest (inf
->num
), pidstr
.c_str (),
8174 string_field ("exit-code", exit_code_str
.c_str ()));
8178 if (uiout
->is_mi_like_p ())
8180 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8181 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8182 plongest (inf
->num
), pidstr
.c_str ());
8186 /* Some targets/architectures can do extra processing/display of
8187 segmentation faults. E.g., Intel MPX boundary faults.
8188 Call the architecture dependent function to handle the fault. */
8191 handle_segmentation_fault (struct ui_out
*uiout
)
8193 struct regcache
*regcache
= get_current_regcache ();
8194 struct gdbarch
*gdbarch
= regcache
->arch ();
8196 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8197 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8201 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8203 struct thread_info
*thr
= inferior_thread ();
8207 if (uiout
->is_mi_like_p ())
8209 else if (show_thread_that_caused_stop ())
8213 uiout
->text ("\nThread ");
8214 uiout
->field_string ("thread-id", print_thread_id (thr
));
8216 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8219 uiout
->text (" \"");
8220 uiout
->field_string ("name", name
);
8225 uiout
->text ("\nProgram");
8227 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8228 uiout
->text (" stopped");
8231 uiout
->text (" received signal ");
8232 annotate_signal_name ();
8233 if (uiout
->is_mi_like_p ())
8235 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8236 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8237 annotate_signal_name_end ();
8239 annotate_signal_string ();
8240 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8242 if (siggnal
== GDB_SIGNAL_SEGV
)
8243 handle_segmentation_fault (uiout
);
8245 annotate_signal_string_end ();
8247 uiout
->text (".\n");
8251 print_no_history_reason (struct ui_out
*uiout
)
8253 uiout
->text ("\nNo more reverse-execution history.\n");
8256 /* Print current location without a level number, if we have changed
8257 functions or hit a breakpoint. Print source line if we have one.
8258 bpstat_print contains the logic deciding in detail what to print,
8259 based on the event(s) that just occurred. */
8262 print_stop_location (struct target_waitstatus
*ws
)
8265 enum print_what source_flag
;
8266 int do_frame_printing
= 1;
8267 struct thread_info
*tp
= inferior_thread ();
8269 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8273 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8274 should) carry around the function and does (or should) use
8275 that when doing a frame comparison. */
8276 if (tp
->control
.stop_step
8277 && frame_id_eq (tp
->control
.step_frame_id
,
8278 get_frame_id (get_current_frame ()))
8279 && (tp
->control
.step_start_function
8280 == find_pc_function (tp
->suspend
.stop_pc
)))
8282 /* Finished step, just print source line. */
8283 source_flag
= SRC_LINE
;
8287 /* Print location and source line. */
8288 source_flag
= SRC_AND_LOC
;
8291 case PRINT_SRC_AND_LOC
:
8292 /* Print location and source line. */
8293 source_flag
= SRC_AND_LOC
;
8295 case PRINT_SRC_ONLY
:
8296 source_flag
= SRC_LINE
;
8299 /* Something bogus. */
8300 source_flag
= SRC_LINE
;
8301 do_frame_printing
= 0;
8304 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8307 /* The behavior of this routine with respect to the source
8309 SRC_LINE: Print only source line
8310 LOCATION: Print only location
8311 SRC_AND_LOC: Print location and source line. */
8312 if (do_frame_printing
)
8313 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8319 print_stop_event (struct ui_out
*uiout
, bool displays
)
8321 struct target_waitstatus last
;
8322 struct thread_info
*tp
;
8324 get_last_target_status (nullptr, nullptr, &last
);
8327 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8329 print_stop_location (&last
);
8331 /* Display the auto-display expressions. */
8336 tp
= inferior_thread ();
8337 if (tp
->thread_fsm
!= NULL
8338 && tp
->thread_fsm
->finished_p ())
8340 struct return_value_info
*rv
;
8342 rv
= tp
->thread_fsm
->return_value ();
8344 print_return_value (uiout
, rv
);
8351 maybe_remove_breakpoints (void)
8353 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8355 if (remove_breakpoints ())
8357 target_terminal::ours_for_output ();
8358 printf_filtered (_("Cannot remove breakpoints because "
8359 "program is no longer writable.\nFurther "
8360 "execution is probably impossible.\n"));
8365 /* The execution context that just caused a normal stop. */
8372 DISABLE_COPY_AND_ASSIGN (stop_context
);
8374 bool changed () const;
8379 /* The event PTID. */
8383 /* If stopp for a thread event, this is the thread that caused the
8385 struct thread_info
*thread
;
8387 /* The inferior that caused the stop. */
8391 /* Initializes a new stop context. If stopped for a thread event, this
8392 takes a strong reference to the thread. */
8394 stop_context::stop_context ()
8396 stop_id
= get_stop_id ();
8397 ptid
= inferior_ptid
;
8398 inf_num
= current_inferior ()->num
;
8400 if (inferior_ptid
!= null_ptid
)
8402 /* Take a strong reference so that the thread can't be deleted
8404 thread
= inferior_thread ();
8411 /* Release a stop context previously created with save_stop_context.
8412 Releases the strong reference to the thread as well. */
8414 stop_context::~stop_context ()
8420 /* Return true if the current context no longer matches the saved stop
8424 stop_context::changed () const
8426 if (ptid
!= inferior_ptid
)
8428 if (inf_num
!= current_inferior ()->num
)
8430 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8432 if (get_stop_id () != stop_id
)
8442 struct target_waitstatus last
;
8444 get_last_target_status (nullptr, nullptr, &last
);
8448 /* If an exception is thrown from this point on, make sure to
8449 propagate GDB's knowledge of the executing state to the
8450 frontend/user running state. A QUIT is an easy exception to see
8451 here, so do this before any filtered output. */
8453 ptid_t finish_ptid
= null_ptid
;
8456 finish_ptid
= minus_one_ptid
;
8457 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8458 || last
.kind
== TARGET_WAITKIND_EXITED
)
8460 /* On some targets, we may still have live threads in the
8461 inferior when we get a process exit event. E.g., for
8462 "checkpoint", when the current checkpoint/fork exits,
8463 linux-fork.c automatically switches to another fork from
8464 within target_mourn_inferior. */
8465 if (inferior_ptid
!= null_ptid
)
8466 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8468 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8469 finish_ptid
= inferior_ptid
;
8471 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8472 if (finish_ptid
!= null_ptid
)
8474 maybe_finish_thread_state
.emplace
8475 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8478 /* As we're presenting a stop, and potentially removing breakpoints,
8479 update the thread list so we can tell whether there are threads
8480 running on the target. With target remote, for example, we can
8481 only learn about new threads when we explicitly update the thread
8482 list. Do this before notifying the interpreters about signal
8483 stops, end of stepping ranges, etc., so that the "new thread"
8484 output is emitted before e.g., "Program received signal FOO",
8485 instead of after. */
8486 update_thread_list ();
8488 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8489 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8491 /* As with the notification of thread events, we want to delay
8492 notifying the user that we've switched thread context until
8493 the inferior actually stops.
8495 There's no point in saying anything if the inferior has exited.
8496 Note that SIGNALLED here means "exited with a signal", not
8497 "received a signal".
8499 Also skip saying anything in non-stop mode. In that mode, as we
8500 don't want GDB to switch threads behind the user's back, to avoid
8501 races where the user is typing a command to apply to thread x,
8502 but GDB switches to thread y before the user finishes entering
8503 the command, fetch_inferior_event installs a cleanup to restore
8504 the current thread back to the thread the user had selected right
8505 after this event is handled, so we're not really switching, only
8506 informing of a stop. */
8508 && previous_inferior_ptid
!= inferior_ptid
8509 && target_has_execution
8510 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8511 && last
.kind
!= TARGET_WAITKIND_EXITED
8512 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8514 SWITCH_THRU_ALL_UIS ()
8516 target_terminal::ours_for_output ();
8517 printf_filtered (_("[Switching to %s]\n"),
8518 target_pid_to_str (inferior_ptid
).c_str ());
8519 annotate_thread_changed ();
8521 previous_inferior_ptid
= inferior_ptid
;
8524 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8526 SWITCH_THRU_ALL_UIS ()
8527 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8529 target_terminal::ours_for_output ();
8530 printf_filtered (_("No unwaited-for children left.\n"));
8534 /* Note: this depends on the update_thread_list call above. */
8535 maybe_remove_breakpoints ();
8537 /* If an auto-display called a function and that got a signal,
8538 delete that auto-display to avoid an infinite recursion. */
8540 if (stopped_by_random_signal
)
8541 disable_current_display ();
8543 SWITCH_THRU_ALL_UIS ()
8545 async_enable_stdin ();
8548 /* Let the user/frontend see the threads as stopped. */
8549 maybe_finish_thread_state
.reset ();
8551 /* Select innermost stack frame - i.e., current frame is frame 0,
8552 and current location is based on that. Handle the case where the
8553 dummy call is returning after being stopped. E.g. the dummy call
8554 previously hit a breakpoint. (If the dummy call returns
8555 normally, we won't reach here.) Do this before the stop hook is
8556 run, so that it doesn't get to see the temporary dummy frame,
8557 which is not where we'll present the stop. */
8558 if (has_stack_frames ())
8560 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8562 /* Pop the empty frame that contains the stack dummy. This
8563 also restores inferior state prior to the call (struct
8564 infcall_suspend_state). */
8565 struct frame_info
*frame
= get_current_frame ();
8567 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8569 /* frame_pop calls reinit_frame_cache as the last thing it
8570 does which means there's now no selected frame. */
8573 select_frame (get_current_frame ());
8575 /* Set the current source location. */
8576 set_current_sal_from_frame (get_current_frame ());
8579 /* Look up the hook_stop and run it (CLI internally handles problem
8580 of stop_command's pre-hook not existing). */
8581 if (stop_command
!= NULL
)
8583 stop_context saved_context
;
8587 execute_cmd_pre_hook (stop_command
);
8589 catch (const gdb_exception
&ex
)
8591 exception_fprintf (gdb_stderr
, ex
,
8592 "Error while running hook_stop:\n");
8595 /* If the stop hook resumes the target, then there's no point in
8596 trying to notify about the previous stop; its context is
8597 gone. Likewise if the command switches thread or inferior --
8598 the observers would print a stop for the wrong
8600 if (saved_context
.changed ())
8604 /* Notify observers about the stop. This is where the interpreters
8605 print the stop event. */
8606 if (inferior_ptid
!= null_ptid
)
8607 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8610 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8612 annotate_stopped ();
8614 if (target_has_execution
)
8616 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8617 && last
.kind
!= TARGET_WAITKIND_EXITED
8618 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8619 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8620 Delete any breakpoint that is to be deleted at the next stop. */
8621 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8624 /* Try to get rid of automatically added inferiors that are no
8625 longer needed. Keeping those around slows down things linearly.
8626 Note that this never removes the current inferior. */
8633 signal_stop_state (int signo
)
8635 return signal_stop
[signo
];
8639 signal_print_state (int signo
)
8641 return signal_print
[signo
];
8645 signal_pass_state (int signo
)
8647 return signal_program
[signo
];
8651 signal_cache_update (int signo
)
8655 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8656 signal_cache_update (signo
);
8661 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8662 && signal_print
[signo
] == 0
8663 && signal_program
[signo
] == 1
8664 && signal_catch
[signo
] == 0);
8668 signal_stop_update (int signo
, int state
)
8670 int ret
= signal_stop
[signo
];
8672 signal_stop
[signo
] = state
;
8673 signal_cache_update (signo
);
8678 signal_print_update (int signo
, int state
)
8680 int ret
= signal_print
[signo
];
8682 signal_print
[signo
] = state
;
8683 signal_cache_update (signo
);
8688 signal_pass_update (int signo
, int state
)
8690 int ret
= signal_program
[signo
];
8692 signal_program
[signo
] = state
;
8693 signal_cache_update (signo
);
8697 /* Update the global 'signal_catch' from INFO and notify the
8701 signal_catch_update (const unsigned int *info
)
8705 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8706 signal_catch
[i
] = info
[i
] > 0;
8707 signal_cache_update (-1);
8708 target_pass_signals (signal_pass
);
8712 sig_print_header (void)
8714 printf_filtered (_("Signal Stop\tPrint\tPass "
8715 "to program\tDescription\n"));
8719 sig_print_info (enum gdb_signal oursig
)
8721 const char *name
= gdb_signal_to_name (oursig
);
8722 int name_padding
= 13 - strlen (name
);
8724 if (name_padding
<= 0)
8727 printf_filtered ("%s", name
);
8728 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8729 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8730 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8731 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8732 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8735 /* Specify how various signals in the inferior should be handled. */
8738 handle_command (const char *args
, int from_tty
)
8740 int digits
, wordlen
;
8741 int sigfirst
, siglast
;
8742 enum gdb_signal oursig
;
8747 error_no_arg (_("signal to handle"));
8750 /* Allocate and zero an array of flags for which signals to handle. */
8752 const size_t nsigs
= GDB_SIGNAL_LAST
;
8753 unsigned char sigs
[nsigs
] {};
8755 /* Break the command line up into args. */
8757 gdb_argv
built_argv (args
);
8759 /* Walk through the args, looking for signal oursigs, signal names, and
8760 actions. Signal numbers and signal names may be interspersed with
8761 actions, with the actions being performed for all signals cumulatively
8762 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8764 for (char *arg
: built_argv
)
8766 wordlen
= strlen (arg
);
8767 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8771 sigfirst
= siglast
= -1;
8773 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8775 /* Apply action to all signals except those used by the
8776 debugger. Silently skip those. */
8779 siglast
= nsigs
- 1;
8781 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8783 SET_SIGS (nsigs
, sigs
, signal_stop
);
8784 SET_SIGS (nsigs
, sigs
, signal_print
);
8786 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8788 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8790 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8792 SET_SIGS (nsigs
, sigs
, signal_print
);
8794 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8796 SET_SIGS (nsigs
, sigs
, signal_program
);
8798 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8800 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8802 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8804 SET_SIGS (nsigs
, sigs
, signal_program
);
8806 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8808 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8809 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8811 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8813 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8815 else if (digits
> 0)
8817 /* It is numeric. The numeric signal refers to our own
8818 internal signal numbering from target.h, not to host/target
8819 signal number. This is a feature; users really should be
8820 using symbolic names anyway, and the common ones like
8821 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8823 sigfirst
= siglast
= (int)
8824 gdb_signal_from_command (atoi (arg
));
8825 if (arg
[digits
] == '-')
8828 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8830 if (sigfirst
> siglast
)
8832 /* Bet he didn't figure we'd think of this case... */
8833 std::swap (sigfirst
, siglast
);
8838 oursig
= gdb_signal_from_name (arg
);
8839 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8841 sigfirst
= siglast
= (int) oursig
;
8845 /* Not a number and not a recognized flag word => complain. */
8846 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8850 /* If any signal numbers or symbol names were found, set flags for
8851 which signals to apply actions to. */
8853 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8855 switch ((enum gdb_signal
) signum
)
8857 case GDB_SIGNAL_TRAP
:
8858 case GDB_SIGNAL_INT
:
8859 if (!allsigs
&& !sigs
[signum
])
8861 if (query (_("%s is used by the debugger.\n\
8862 Are you sure you want to change it? "),
8863 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8868 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8872 case GDB_SIGNAL_DEFAULT
:
8873 case GDB_SIGNAL_UNKNOWN
:
8874 /* Make sure that "all" doesn't print these. */
8883 for (int signum
= 0; signum
< nsigs
; signum
++)
8886 signal_cache_update (-1);
8887 target_pass_signals (signal_pass
);
8888 target_program_signals (signal_program
);
8892 /* Show the results. */
8893 sig_print_header ();
8894 for (; signum
< nsigs
; signum
++)
8896 sig_print_info ((enum gdb_signal
) signum
);
8903 /* Complete the "handle" command. */
8906 handle_completer (struct cmd_list_element
*ignore
,
8907 completion_tracker
&tracker
,
8908 const char *text
, const char *word
)
8910 static const char * const keywords
[] =
8924 signal_completer (ignore
, tracker
, text
, word
);
8925 complete_on_enum (tracker
, keywords
, word
, word
);
8929 gdb_signal_from_command (int num
)
8931 if (num
>= 1 && num
<= 15)
8932 return (enum gdb_signal
) num
;
8933 error (_("Only signals 1-15 are valid as numeric signals.\n\
8934 Use \"info signals\" for a list of symbolic signals."));
8937 /* Print current contents of the tables set by the handle command.
8938 It is possible we should just be printing signals actually used
8939 by the current target (but for things to work right when switching
8940 targets, all signals should be in the signal tables). */
8943 info_signals_command (const char *signum_exp
, int from_tty
)
8945 enum gdb_signal oursig
;
8947 sig_print_header ();
8951 /* First see if this is a symbol name. */
8952 oursig
= gdb_signal_from_name (signum_exp
);
8953 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8955 /* No, try numeric. */
8957 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8959 sig_print_info (oursig
);
8963 printf_filtered ("\n");
8964 /* These ugly casts brought to you by the native VAX compiler. */
8965 for (oursig
= GDB_SIGNAL_FIRST
;
8966 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8967 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8971 if (oursig
!= GDB_SIGNAL_UNKNOWN
8972 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8973 sig_print_info (oursig
);
8976 printf_filtered (_("\nUse the \"handle\" command "
8977 "to change these tables.\n"));
8980 /* The $_siginfo convenience variable is a bit special. We don't know
8981 for sure the type of the value until we actually have a chance to
8982 fetch the data. The type can change depending on gdbarch, so it is
8983 also dependent on which thread you have selected.
8985 1. making $_siginfo be an internalvar that creates a new value on
8988 2. making the value of $_siginfo be an lval_computed value. */
8990 /* This function implements the lval_computed support for reading a
8994 siginfo_value_read (struct value
*v
)
8996 LONGEST transferred
;
8998 /* If we can access registers, so can we access $_siginfo. Likewise
9000 validate_registers_access ();
9003 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
9005 value_contents_all_raw (v
),
9007 TYPE_LENGTH (value_type (v
)));
9009 if (transferred
!= TYPE_LENGTH (value_type (v
)))
9010 error (_("Unable to read siginfo"));
9013 /* This function implements the lval_computed support for writing a
9017 siginfo_value_write (struct value
*v
, struct value
*fromval
)
9019 LONGEST transferred
;
9021 /* If we can access registers, so can we access $_siginfo. Likewise
9023 validate_registers_access ();
9025 transferred
= target_write (current_top_target (),
9026 TARGET_OBJECT_SIGNAL_INFO
,
9028 value_contents_all_raw (fromval
),
9030 TYPE_LENGTH (value_type (fromval
)));
9032 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
9033 error (_("Unable to write siginfo"));
9036 static const struct lval_funcs siginfo_value_funcs
=
9042 /* Return a new value with the correct type for the siginfo object of
9043 the current thread using architecture GDBARCH. Return a void value
9044 if there's no object available. */
9046 static struct value
*
9047 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9050 if (target_has_stack
9051 && inferior_ptid
!= null_ptid
9052 && gdbarch_get_siginfo_type_p (gdbarch
))
9054 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9056 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9059 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9063 /* infcall_suspend_state contains state about the program itself like its
9064 registers and any signal it received when it last stopped.
9065 This state must be restored regardless of how the inferior function call
9066 ends (either successfully, or after it hits a breakpoint or signal)
9067 if the program is to properly continue where it left off. */
9069 class infcall_suspend_state
9072 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9073 once the inferior function call has finished. */
9074 infcall_suspend_state (struct gdbarch
*gdbarch
,
9075 const struct thread_info
*tp
,
9076 struct regcache
*regcache
)
9077 : m_thread_suspend (tp
->suspend
),
9078 m_registers (new readonly_detached_regcache (*regcache
))
9080 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9082 if (gdbarch_get_siginfo_type_p (gdbarch
))
9084 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9085 size_t len
= TYPE_LENGTH (type
);
9087 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9089 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9090 siginfo_data
.get (), 0, len
) != len
)
9092 /* Errors ignored. */
9093 siginfo_data
.reset (nullptr);
9099 m_siginfo_gdbarch
= gdbarch
;
9100 m_siginfo_data
= std::move (siginfo_data
);
9104 /* Return a pointer to the stored register state. */
9106 readonly_detached_regcache
*registers () const
9108 return m_registers
.get ();
9111 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9113 void restore (struct gdbarch
*gdbarch
,
9114 struct thread_info
*tp
,
9115 struct regcache
*regcache
) const
9117 tp
->suspend
= m_thread_suspend
;
9119 if (m_siginfo_gdbarch
== gdbarch
)
9121 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9123 /* Errors ignored. */
9124 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9125 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9128 /* The inferior can be gone if the user types "print exit(0)"
9129 (and perhaps other times). */
9130 if (target_has_execution
)
9131 /* NB: The register write goes through to the target. */
9132 regcache
->restore (registers ());
9136 /* How the current thread stopped before the inferior function call was
9138 struct thread_suspend_state m_thread_suspend
;
9140 /* The registers before the inferior function call was executed. */
9141 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9143 /* Format of SIGINFO_DATA or NULL if it is not present. */
9144 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9146 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9147 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9148 content would be invalid. */
9149 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9152 infcall_suspend_state_up
9153 save_infcall_suspend_state ()
9155 struct thread_info
*tp
= inferior_thread ();
9156 struct regcache
*regcache
= get_current_regcache ();
9157 struct gdbarch
*gdbarch
= regcache
->arch ();
9159 infcall_suspend_state_up inf_state
9160 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9162 /* Having saved the current state, adjust the thread state, discarding
9163 any stop signal information. The stop signal is not useful when
9164 starting an inferior function call, and run_inferior_call will not use
9165 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9166 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9171 /* Restore inferior session state to INF_STATE. */
9174 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9176 struct thread_info
*tp
= inferior_thread ();
9177 struct regcache
*regcache
= get_current_regcache ();
9178 struct gdbarch
*gdbarch
= regcache
->arch ();
9180 inf_state
->restore (gdbarch
, tp
, regcache
);
9181 discard_infcall_suspend_state (inf_state
);
9185 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9190 readonly_detached_regcache
*
9191 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9193 return inf_state
->registers ();
9196 /* infcall_control_state contains state regarding gdb's control of the
9197 inferior itself like stepping control. It also contains session state like
9198 the user's currently selected frame. */
9200 struct infcall_control_state
9202 struct thread_control_state thread_control
;
9203 struct inferior_control_state inferior_control
;
9206 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9207 int stopped_by_random_signal
= 0;
9209 /* ID if the selected frame when the inferior function call was made. */
9210 struct frame_id selected_frame_id
{};
9213 /* Save all of the information associated with the inferior<==>gdb
9216 infcall_control_state_up
9217 save_infcall_control_state ()
9219 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9220 struct thread_info
*tp
= inferior_thread ();
9221 struct inferior
*inf
= current_inferior ();
9223 inf_status
->thread_control
= tp
->control
;
9224 inf_status
->inferior_control
= inf
->control
;
9226 tp
->control
.step_resume_breakpoint
= NULL
;
9227 tp
->control
.exception_resume_breakpoint
= NULL
;
9229 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9230 chain. If caller's caller is walking the chain, they'll be happier if we
9231 hand them back the original chain when restore_infcall_control_state is
9233 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9236 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9237 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9239 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9245 restore_selected_frame (const frame_id
&fid
)
9247 frame_info
*frame
= frame_find_by_id (fid
);
9249 /* If inf_status->selected_frame_id is NULL, there was no previously
9253 warning (_("Unable to restore previously selected frame."));
9257 select_frame (frame
);
9260 /* Restore inferior session state to INF_STATUS. */
9263 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9265 struct thread_info
*tp
= inferior_thread ();
9266 struct inferior
*inf
= current_inferior ();
9268 if (tp
->control
.step_resume_breakpoint
)
9269 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9271 if (tp
->control
.exception_resume_breakpoint
)
9272 tp
->control
.exception_resume_breakpoint
->disposition
9273 = disp_del_at_next_stop
;
9275 /* Handle the bpstat_copy of the chain. */
9276 bpstat_clear (&tp
->control
.stop_bpstat
);
9278 tp
->control
= inf_status
->thread_control
;
9279 inf
->control
= inf_status
->inferior_control
;
9282 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9283 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9285 if (target_has_stack
)
9287 /* The point of the try/catch is that if the stack is clobbered,
9288 walking the stack might encounter a garbage pointer and
9289 error() trying to dereference it. */
9292 restore_selected_frame (inf_status
->selected_frame_id
);
9294 catch (const gdb_exception_error
&ex
)
9296 exception_fprintf (gdb_stderr
, ex
,
9297 "Unable to restore previously selected frame:\n");
9298 /* Error in restoring the selected frame. Select the
9300 select_frame (get_current_frame ());
9308 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9310 if (inf_status
->thread_control
.step_resume_breakpoint
)
9311 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9312 = disp_del_at_next_stop
;
9314 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9315 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9316 = disp_del_at_next_stop
;
9318 /* See save_infcall_control_state for info on stop_bpstat. */
9319 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9327 clear_exit_convenience_vars (void)
9329 clear_internalvar (lookup_internalvar ("_exitsignal"));
9330 clear_internalvar (lookup_internalvar ("_exitcode"));
9334 /* User interface for reverse debugging:
9335 Set exec-direction / show exec-direction commands
9336 (returns error unless target implements to_set_exec_direction method). */
9338 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9339 static const char exec_forward
[] = "forward";
9340 static const char exec_reverse
[] = "reverse";
9341 static const char *exec_direction
= exec_forward
;
9342 static const char *const exec_direction_names
[] = {
9349 set_exec_direction_func (const char *args
, int from_tty
,
9350 struct cmd_list_element
*cmd
)
9352 if (target_can_execute_reverse
)
9354 if (!strcmp (exec_direction
, exec_forward
))
9355 execution_direction
= EXEC_FORWARD
;
9356 else if (!strcmp (exec_direction
, exec_reverse
))
9357 execution_direction
= EXEC_REVERSE
;
9361 exec_direction
= exec_forward
;
9362 error (_("Target does not support this operation."));
9367 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9368 struct cmd_list_element
*cmd
, const char *value
)
9370 switch (execution_direction
) {
9372 fprintf_filtered (out
, _("Forward.\n"));
9375 fprintf_filtered (out
, _("Reverse.\n"));
9378 internal_error (__FILE__
, __LINE__
,
9379 _("bogus execution_direction value: %d"),
9380 (int) execution_direction
);
9385 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9386 struct cmd_list_element
*c
, const char *value
)
9388 fprintf_filtered (file
, _("Resuming the execution of threads "
9389 "of all processes is %s.\n"), value
);
9392 /* Implementation of `siginfo' variable. */
9394 static const struct internalvar_funcs siginfo_funcs
=
9401 /* Callback for infrun's target events source. This is marked when a
9402 thread has a pending status to process. */
9405 infrun_async_inferior_event_handler (gdb_client_data data
)
9407 inferior_event_handler (INF_REG_EVENT
, NULL
);
9410 void _initialize_infrun ();
9412 _initialize_infrun ()
9414 struct cmd_list_element
*c
;
9416 /* Register extra event sources in the event loop. */
9417 infrun_async_inferior_event_token
9418 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9420 add_info ("signals", info_signals_command
, _("\
9421 What debugger does when program gets various signals.\n\
9422 Specify a signal as argument to print info on that signal only."));
9423 add_info_alias ("handle", "signals", 0);
9425 c
= add_com ("handle", class_run
, handle_command
, _("\
9426 Specify how to handle signals.\n\
9427 Usage: handle SIGNAL [ACTIONS]\n\
9428 Args are signals and actions to apply to those signals.\n\
9429 If no actions are specified, the current settings for the specified signals\n\
9430 will be displayed instead.\n\
9432 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9433 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9434 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9435 The special arg \"all\" is recognized to mean all signals except those\n\
9436 used by the debugger, typically SIGTRAP and SIGINT.\n\
9438 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9439 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9440 Stop means reenter debugger if this signal happens (implies print).\n\
9441 Print means print a message if this signal happens.\n\
9442 Pass means let program see this signal; otherwise program doesn't know.\n\
9443 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9444 Pass and Stop may be combined.\n\
9446 Multiple signals may be specified. Signal numbers and signal names\n\
9447 may be interspersed with actions, with the actions being performed for\n\
9448 all signals cumulatively specified."));
9449 set_cmd_completer (c
, handle_completer
);
9452 stop_command
= add_cmd ("stop", class_obscure
,
9453 not_just_help_class_command
, _("\
9454 There is no `stop' command, but you can set a hook on `stop'.\n\
9455 This allows you to set a list of commands to be run each time execution\n\
9456 of the program stops."), &cmdlist
);
9458 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9459 Set inferior debugging."), _("\
9460 Show inferior debugging."), _("\
9461 When non-zero, inferior specific debugging is enabled."),
9464 &setdebuglist
, &showdebuglist
);
9466 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9467 &debug_displaced
, _("\
9468 Set displaced stepping debugging."), _("\
9469 Show displaced stepping debugging."), _("\
9470 When non-zero, displaced stepping specific debugging is enabled."),
9472 show_debug_displaced
,
9473 &setdebuglist
, &showdebuglist
);
9475 add_setshow_boolean_cmd ("non-stop", no_class
,
9477 Set whether gdb controls the inferior in non-stop mode."), _("\
9478 Show whether gdb controls the inferior in non-stop mode."), _("\
9479 When debugging a multi-threaded program and this setting is\n\
9480 off (the default, also called all-stop mode), when one thread stops\n\
9481 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9482 all other threads in the program while you interact with the thread of\n\
9483 interest. When you continue or step a thread, you can allow the other\n\
9484 threads to run, or have them remain stopped, but while you inspect any\n\
9485 thread's state, all threads stop.\n\
9487 In non-stop mode, when one thread stops, other threads can continue\n\
9488 to run freely. You'll be able to step each thread independently,\n\
9489 leave it stopped or free to run as needed."),
9495 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9498 signal_print
[i
] = 1;
9499 signal_program
[i
] = 1;
9500 signal_catch
[i
] = 0;
9503 /* Signals caused by debugger's own actions should not be given to
9504 the program afterwards.
9506 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9507 explicitly specifies that it should be delivered to the target
9508 program. Typically, that would occur when a user is debugging a
9509 target monitor on a simulator: the target monitor sets a
9510 breakpoint; the simulator encounters this breakpoint and halts
9511 the simulation handing control to GDB; GDB, noting that the stop
9512 address doesn't map to any known breakpoint, returns control back
9513 to the simulator; the simulator then delivers the hardware
9514 equivalent of a GDB_SIGNAL_TRAP to the program being
9516 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9517 signal_program
[GDB_SIGNAL_INT
] = 0;
9519 /* Signals that are not errors should not normally enter the debugger. */
9520 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9521 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9522 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9523 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9524 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9525 signal_print
[GDB_SIGNAL_PROF
] = 0;
9526 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9527 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9528 signal_stop
[GDB_SIGNAL_IO
] = 0;
9529 signal_print
[GDB_SIGNAL_IO
] = 0;
9530 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9531 signal_print
[GDB_SIGNAL_POLL
] = 0;
9532 signal_stop
[GDB_SIGNAL_URG
] = 0;
9533 signal_print
[GDB_SIGNAL_URG
] = 0;
9534 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9535 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9536 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9537 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9539 /* These signals are used internally by user-level thread
9540 implementations. (See signal(5) on Solaris.) Like the above
9541 signals, a healthy program receives and handles them as part of
9542 its normal operation. */
9543 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9544 signal_print
[GDB_SIGNAL_LWP
] = 0;
9545 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9546 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9547 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9548 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9549 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9550 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9552 /* Update cached state. */
9553 signal_cache_update (-1);
9555 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9556 &stop_on_solib_events
, _("\
9557 Set stopping for shared library events."), _("\
9558 Show stopping for shared library events."), _("\
9559 If nonzero, gdb will give control to the user when the dynamic linker\n\
9560 notifies gdb of shared library events. The most common event of interest\n\
9561 to the user would be loading/unloading of a new library."),
9562 set_stop_on_solib_events
,
9563 show_stop_on_solib_events
,
9564 &setlist
, &showlist
);
9566 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9567 follow_fork_mode_kind_names
,
9568 &follow_fork_mode_string
, _("\
9569 Set debugger response to a program call of fork or vfork."), _("\
9570 Show debugger response to a program call of fork or vfork."), _("\
9571 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9572 parent - the original process is debugged after a fork\n\
9573 child - the new process is debugged after a fork\n\
9574 The unfollowed process will continue to run.\n\
9575 By default, the debugger will follow the parent process."),
9577 show_follow_fork_mode_string
,
9578 &setlist
, &showlist
);
9580 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9581 follow_exec_mode_names
,
9582 &follow_exec_mode_string
, _("\
9583 Set debugger response to a program call of exec."), _("\
9584 Show debugger response to a program call of exec."), _("\
9585 An exec call replaces the program image of a process.\n\
9587 follow-exec-mode can be:\n\
9589 new - the debugger creates a new inferior and rebinds the process\n\
9590 to this new inferior. The program the process was running before\n\
9591 the exec call can be restarted afterwards by restarting the original\n\
9594 same - the debugger keeps the process bound to the same inferior.\n\
9595 The new executable image replaces the previous executable loaded in\n\
9596 the inferior. Restarting the inferior after the exec call restarts\n\
9597 the executable the process was running after the exec call.\n\
9599 By default, the debugger will use the same inferior."),
9601 show_follow_exec_mode_string
,
9602 &setlist
, &showlist
);
9604 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9605 scheduler_enums
, &scheduler_mode
, _("\
9606 Set mode for locking scheduler during execution."), _("\
9607 Show mode for locking scheduler during execution."), _("\
9608 off == no locking (threads may preempt at any time)\n\
9609 on == full locking (no thread except the current thread may run)\n\
9610 This applies to both normal execution and replay mode.\n\
9611 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9612 In this mode, other threads may run during other commands.\n\
9613 This applies to both normal execution and replay mode.\n\
9614 replay == scheduler locked in replay mode and unlocked during normal execution."),
9615 set_schedlock_func
, /* traps on target vector */
9616 show_scheduler_mode
,
9617 &setlist
, &showlist
);
9619 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9620 Set mode for resuming threads of all processes."), _("\
9621 Show mode for resuming threads of all processes."), _("\
9622 When on, execution commands (such as 'continue' or 'next') resume all\n\
9623 threads of all processes. When off (which is the default), execution\n\
9624 commands only resume the threads of the current process. The set of\n\
9625 threads that are resumed is further refined by the scheduler-locking\n\
9626 mode (see help set scheduler-locking)."),
9628 show_schedule_multiple
,
9629 &setlist
, &showlist
);
9631 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9632 Set mode of the step operation."), _("\
9633 Show mode of the step operation."), _("\
9634 When set, doing a step over a function without debug line information\n\
9635 will stop at the first instruction of that function. Otherwise, the\n\
9636 function is skipped and the step command stops at a different source line."),
9638 show_step_stop_if_no_debug
,
9639 &setlist
, &showlist
);
9641 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9642 &can_use_displaced_stepping
, _("\
9643 Set debugger's willingness to use displaced stepping."), _("\
9644 Show debugger's willingness to use displaced stepping."), _("\
9645 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9646 supported by the target architecture. If off, gdb will not use displaced\n\
9647 stepping to step over breakpoints, even if such is supported by the target\n\
9648 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9649 if the target architecture supports it and non-stop mode is active, but will not\n\
9650 use it in all-stop mode (see help set non-stop)."),
9652 show_can_use_displaced_stepping
,
9653 &setlist
, &showlist
);
9655 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9656 &exec_direction
, _("Set direction of execution.\n\
9657 Options are 'forward' or 'reverse'."),
9658 _("Show direction of execution (forward/reverse)."),
9659 _("Tells gdb whether to execute forward or backward."),
9660 set_exec_direction_func
, show_exec_direction_func
,
9661 &setlist
, &showlist
);
9663 /* Set/show detach-on-fork: user-settable mode. */
9665 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9666 Set whether gdb will detach the child of a fork."), _("\
9667 Show whether gdb will detach the child of a fork."), _("\
9668 Tells gdb whether to detach the child of a fork."),
9669 NULL
, NULL
, &setlist
, &showlist
);
9671 /* Set/show disable address space randomization mode. */
9673 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9674 &disable_randomization
, _("\
9675 Set disabling of debuggee's virtual address space randomization."), _("\
9676 Show disabling of debuggee's virtual address space randomization."), _("\
9677 When this mode is on (which is the default), randomization of the virtual\n\
9678 address space is disabled. Standalone programs run with the randomization\n\
9679 enabled by default on some platforms."),
9680 &set_disable_randomization
,
9681 &show_disable_randomization
,
9682 &setlist
, &showlist
);
9684 /* ptid initializations */
9685 inferior_ptid
= null_ptid
;
9686 target_last_wait_ptid
= minus_one_ptid
;
9688 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9689 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9690 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9691 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9693 /* Explicitly create without lookup, since that tries to create a
9694 value with a void typed value, and when we get here, gdbarch
9695 isn't initialized yet. At this point, we're quite sure there
9696 isn't another convenience variable of the same name. */
9697 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9699 add_setshow_boolean_cmd ("observer", no_class
,
9700 &observer_mode_1
, _("\
9701 Set whether gdb controls the inferior in observer mode."), _("\
9702 Show whether gdb controls the inferior in observer mode."), _("\
9703 In observer mode, GDB can get data from the inferior, but not\n\
9704 affect its execution. Registers and memory may not be changed,\n\
9705 breakpoints may not be set, and the program cannot be interrupted\n\