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/>. */
22 #include "displaced-stepping.h"
28 #include "breakpoint.h"
32 #include "target-connection.h"
33 #include "gdbthread.h"
40 #include "observable.h"
45 #include "mi/mi-common.h"
46 #include "event-top.h"
48 #include "record-full.h"
49 #include "inline-frame.h"
51 #include "tracepoint.h"
55 #include "completer.h"
56 #include "target-descriptions.h"
57 #include "target-dcache.h"
60 #include "gdbsupport/event-loop.h"
61 #include "thread-fsm.h"
62 #include "gdbsupport/enum-flags.h"
63 #include "progspace-and-thread.h"
64 #include "gdbsupport/gdb_optional.h"
65 #include "arch-utils.h"
66 #include "gdbsupport/scope-exit.h"
67 #include "gdbsupport/forward-scope-exit.h"
68 #include "gdbsupport/gdb_select.h"
69 #include <unordered_map>
70 #include "async-event.h"
71 #include "gdbsupport/selftest.h"
72 #include "scoped-mock-context.h"
73 #include "test-target.h"
74 #include "gdbsupport/common-debug.h"
76 /* Prototypes for local functions */
78 static void sig_print_info (enum gdb_signal
);
80 static void sig_print_header (void);
82 static void follow_inferior_reset_breakpoints (void);
84 static bool currently_stepping (struct thread_info
*tp
);
86 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
88 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
90 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
92 static bool maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
94 static void resume (gdb_signal sig
);
96 static void wait_for_inferior (inferior
*inf
);
98 /* Asynchronous signal handler registered as event loop source for
99 when we have pending events ready to be passed to the core. */
100 static struct async_event_handler
*infrun_async_inferior_event_token
;
102 /* Stores whether infrun_async was previously enabled or disabled.
103 Starts off as -1, indicating "never enabled/disabled". */
104 static int infrun_is_async
= -1;
109 infrun_async (int enable
)
111 if (infrun_is_async
!= enable
)
113 infrun_is_async
= enable
;
115 infrun_debug_printf ("enable=%d", enable
);
118 mark_async_event_handler (infrun_async_inferior_event_token
);
120 clear_async_event_handler (infrun_async_inferior_event_token
);
127 mark_infrun_async_event_handler (void)
129 mark_async_event_handler (infrun_async_inferior_event_token
);
132 /* When set, stop the 'step' command if we enter a function which has
133 no line number information. The normal behavior is that we step
134 over such function. */
135 bool step_stop_if_no_debug
= false;
137 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
138 struct cmd_list_element
*c
, const char *value
)
140 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
143 /* proceed and normal_stop use this to notify the user when the
144 inferior stopped in a different thread than it had been running
147 static ptid_t previous_inferior_ptid
;
149 /* If set (default for legacy reasons), when following a fork, GDB
150 will detach from one of the fork branches, child or parent.
151 Exactly which branch is detached depends on 'set follow-fork-mode'
154 static bool detach_fork
= true;
156 bool debug_displaced
= false;
158 show_debug_displaced (struct ui_file
*file
, int from_tty
,
159 struct cmd_list_element
*c
, const char *value
)
161 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
164 unsigned int debug_infrun
= 0;
166 show_debug_infrun (struct ui_file
*file
, int from_tty
,
167 struct cmd_list_element
*c
, const char *value
)
169 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
172 /* Support for disabling address space randomization. */
174 bool disable_randomization
= true;
177 show_disable_randomization (struct ui_file
*file
, int from_tty
,
178 struct cmd_list_element
*c
, const char *value
)
180 if (target_supports_disable_randomization ())
181 fprintf_filtered (file
,
182 _("Disabling randomization of debuggee's "
183 "virtual address space is %s.\n"),
186 fputs_filtered (_("Disabling randomization of debuggee's "
187 "virtual address space is unsupported on\n"
188 "this platform.\n"), file
);
192 set_disable_randomization (const char *args
, int from_tty
,
193 struct cmd_list_element
*c
)
195 if (!target_supports_disable_randomization ())
196 error (_("Disabling randomization of debuggee's "
197 "virtual address space is unsupported on\n"
201 /* User interface for non-stop mode. */
203 bool non_stop
= false;
204 static bool non_stop_1
= false;
207 set_non_stop (const char *args
, int from_tty
,
208 struct cmd_list_element
*c
)
210 if (target_has_execution ())
212 non_stop_1
= non_stop
;
213 error (_("Cannot change this setting while the inferior is running."));
216 non_stop
= non_stop_1
;
220 show_non_stop (struct ui_file
*file
, int from_tty
,
221 struct cmd_list_element
*c
, const char *value
)
223 fprintf_filtered (file
,
224 _("Controlling the inferior in non-stop mode is %s.\n"),
228 /* "Observer mode" is somewhat like a more extreme version of
229 non-stop, in which all GDB operations that might affect the
230 target's execution have been disabled. */
232 bool observer_mode
= false;
233 static bool observer_mode_1
= false;
236 set_observer_mode (const char *args
, int from_tty
,
237 struct cmd_list_element
*c
)
239 if (target_has_execution ())
241 observer_mode_1
= observer_mode
;
242 error (_("Cannot change this setting while the inferior is running."));
245 observer_mode
= observer_mode_1
;
247 may_write_registers
= !observer_mode
;
248 may_write_memory
= !observer_mode
;
249 may_insert_breakpoints
= !observer_mode
;
250 may_insert_tracepoints
= !observer_mode
;
251 /* We can insert fast tracepoints in or out of observer mode,
252 but enable them if we're going into this mode. */
254 may_insert_fast_tracepoints
= true;
255 may_stop
= !observer_mode
;
256 update_target_permissions ();
258 /* Going *into* observer mode we must force non-stop, then
259 going out we leave it that way. */
262 pagination_enabled
= 0;
263 non_stop
= non_stop_1
= true;
267 printf_filtered (_("Observer mode is now %s.\n"),
268 (observer_mode
? "on" : "off"));
272 show_observer_mode (struct ui_file
*file
, int from_tty
,
273 struct cmd_list_element
*c
, const char *value
)
275 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
278 /* This updates the value of observer mode based on changes in
279 permissions. Note that we are deliberately ignoring the values of
280 may-write-registers and may-write-memory, since the user may have
281 reason to enable these during a session, for instance to turn on a
282 debugging-related global. */
285 update_observer_mode (void)
287 bool newval
= (!may_insert_breakpoints
288 && !may_insert_tracepoints
289 && may_insert_fast_tracepoints
293 /* Let the user know if things change. */
294 if (newval
!= observer_mode
)
295 printf_filtered (_("Observer mode is now %s.\n"),
296 (newval
? "on" : "off"));
298 observer_mode
= observer_mode_1
= newval
;
301 /* Tables of how to react to signals; the user sets them. */
303 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
304 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
305 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
307 /* Table of signals that are registered with "catch signal". A
308 non-zero entry indicates that the signal is caught by some "catch
310 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
312 /* Table of signals that the target may silently handle.
313 This is automatically determined from the flags above,
314 and simply cached here. */
315 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
317 #define SET_SIGS(nsigs,sigs,flags) \
319 int signum = (nsigs); \
320 while (signum-- > 0) \
321 if ((sigs)[signum]) \
322 (flags)[signum] = 1; \
325 #define UNSET_SIGS(nsigs,sigs,flags) \
327 int signum = (nsigs); \
328 while (signum-- > 0) \
329 if ((sigs)[signum]) \
330 (flags)[signum] = 0; \
333 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
334 this function is to avoid exporting `signal_program'. */
337 update_signals_program_target (void)
339 target_program_signals (signal_program
);
342 /* Value to pass to target_resume() to cause all threads to resume. */
344 #define RESUME_ALL minus_one_ptid
346 /* Command list pointer for the "stop" placeholder. */
348 static struct cmd_list_element
*stop_command
;
350 /* Nonzero if we want to give control to the user when we're notified
351 of shared library events by the dynamic linker. */
352 int stop_on_solib_events
;
354 /* Enable or disable optional shared library event breakpoints
355 as appropriate when the above flag is changed. */
358 set_stop_on_solib_events (const char *args
,
359 int from_tty
, struct cmd_list_element
*c
)
361 update_solib_breakpoints ();
365 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
366 struct cmd_list_element
*c
, const char *value
)
368 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
372 /* True after stop if current stack frame should be printed. */
374 static bool stop_print_frame
;
376 /* This is a cached copy of the target/ptid/waitstatus of the last
377 event returned by target_wait()/deprecated_target_wait_hook().
378 This information is returned by get_last_target_status(). */
379 static process_stratum_target
*target_last_proc_target
;
380 static ptid_t target_last_wait_ptid
;
381 static struct target_waitstatus target_last_waitstatus
;
383 void init_thread_stepping_state (struct thread_info
*tss
);
385 static const char follow_fork_mode_child
[] = "child";
386 static const char follow_fork_mode_parent
[] = "parent";
388 static const char *const follow_fork_mode_kind_names
[] = {
389 follow_fork_mode_child
,
390 follow_fork_mode_parent
,
394 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
396 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
397 struct cmd_list_element
*c
, const char *value
)
399 fprintf_filtered (file
,
400 _("Debugger response to a program "
401 "call of fork or vfork is \"%s\".\n"),
406 /* Handle changes to the inferior list based on the type of fork,
407 which process is being followed, and whether the other process
408 should be detached. On entry inferior_ptid must be the ptid of
409 the fork parent. At return inferior_ptid is the ptid of the
410 followed inferior. */
413 follow_fork_inferior (bool follow_child
, bool detach_fork
)
416 ptid_t parent_ptid
, child_ptid
;
418 has_vforked
= (inferior_thread ()->pending_follow
.kind
419 == TARGET_WAITKIND_VFORKED
);
420 parent_ptid
= inferior_ptid
;
421 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
424 && !non_stop
/* Non-stop always resumes both branches. */
425 && current_ui
->prompt_state
== PROMPT_BLOCKED
426 && !(follow_child
|| detach_fork
|| sched_multi
))
428 /* The parent stays blocked inside the vfork syscall until the
429 child execs or exits. If we don't let the child run, then
430 the parent stays blocked. If we're telling the parent to run
431 in the foreground, the user will not be able to ctrl-c to get
432 back the terminal, effectively hanging the debug session. */
433 fprintf_filtered (gdb_stderr
, _("\
434 Can not resume the parent process over vfork in the foreground while\n\
435 holding the child stopped. Try \"set detach-on-fork\" or \
436 \"set schedule-multiple\".\n"));
442 /* Detach new forked process? */
445 /* Before detaching from the child, remove all breakpoints
446 from it. If we forked, then this has already been taken
447 care of by infrun.c. If we vforked however, any
448 breakpoint inserted in the parent is visible in the
449 child, even those added while stopped in a vfork
450 catchpoint. This will remove the breakpoints from the
451 parent also, but they'll be reinserted below. */
454 /* Keep breakpoints list in sync. */
455 remove_breakpoints_inf (current_inferior ());
458 if (print_inferior_events
)
460 /* Ensure that we have a process ptid. */
461 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
463 target_terminal::ours_for_output ();
464 fprintf_filtered (gdb_stdlog
,
465 _("[Detaching after %s from child %s]\n"),
466 has_vforked
? "vfork" : "fork",
467 target_pid_to_str (process_ptid
).c_str ());
472 struct inferior
*parent_inf
, *child_inf
;
474 /* Add process to GDB's tables. */
475 child_inf
= add_inferior (child_ptid
.pid ());
477 parent_inf
= current_inferior ();
478 child_inf
->attach_flag
= parent_inf
->attach_flag
;
479 copy_terminal_info (child_inf
, parent_inf
);
480 child_inf
->gdbarch
= parent_inf
->gdbarch
;
481 copy_inferior_target_desc_info (child_inf
, parent_inf
);
483 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
485 set_current_inferior (child_inf
);
486 switch_to_no_thread ();
487 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
488 push_target (parent_inf
->process_target ());
489 thread_info
*child_thr
490 = add_thread_silent (child_inf
->process_target (), child_ptid
);
492 /* If this is a vfork child, then the address-space is
493 shared with the parent. */
496 child_inf
->pspace
= parent_inf
->pspace
;
497 child_inf
->aspace
= parent_inf
->aspace
;
501 /* The parent will be frozen until the child is done
502 with the shared region. Keep track of the
504 child_inf
->vfork_parent
= parent_inf
;
505 child_inf
->pending_detach
= 0;
506 parent_inf
->vfork_child
= child_inf
;
507 parent_inf
->pending_detach
= 0;
509 /* Now that the inferiors and program spaces are all
510 wired up, we can switch to the child thread (which
511 switches inferior and program space too). */
512 switch_to_thread (child_thr
);
516 child_inf
->aspace
= new_address_space ();
517 child_inf
->pspace
= new program_space (child_inf
->aspace
);
518 child_inf
->removable
= 1;
519 set_current_program_space (child_inf
->pspace
);
520 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
522 /* solib_create_inferior_hook relies on the current
524 switch_to_thread (child_thr
);
526 /* Let the shared library layer (e.g., solib-svr4) learn
527 about this new process, relocate the cloned exec, pull
528 in shared libraries, and install the solib event
529 breakpoint. If a "cloned-VM" event was propagated
530 better throughout the core, this wouldn't be
532 solib_create_inferior_hook (0);
538 struct inferior
*parent_inf
;
540 parent_inf
= current_inferior ();
542 /* If we detached from the child, then we have to be careful
543 to not insert breakpoints in the parent until the child
544 is done with the shared memory region. However, if we're
545 staying attached to the child, then we can and should
546 insert breakpoints, so that we can debug it. A
547 subsequent child exec or exit is enough to know when does
548 the child stops using the parent's address space. */
549 parent_inf
->waiting_for_vfork_done
= detach_fork
;
550 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
555 /* Follow the child. */
556 struct inferior
*parent_inf
, *child_inf
;
557 struct program_space
*parent_pspace
;
559 if (print_inferior_events
)
561 std::string parent_pid
= target_pid_to_str (parent_ptid
);
562 std::string child_pid
= target_pid_to_str (child_ptid
);
564 target_terminal::ours_for_output ();
565 fprintf_filtered (gdb_stdlog
,
566 _("[Attaching after %s %s to child %s]\n"),
568 has_vforked
? "vfork" : "fork",
572 /* Add the new inferior first, so that the target_detach below
573 doesn't unpush the target. */
575 child_inf
= add_inferior (child_ptid
.pid ());
577 parent_inf
= current_inferior ();
578 child_inf
->attach_flag
= parent_inf
->attach_flag
;
579 copy_terminal_info (child_inf
, parent_inf
);
580 child_inf
->gdbarch
= parent_inf
->gdbarch
;
581 copy_inferior_target_desc_info (child_inf
, parent_inf
);
583 parent_pspace
= parent_inf
->pspace
;
585 process_stratum_target
*target
= parent_inf
->process_target ();
588 /* Hold a strong reference to the target while (maybe)
589 detaching the parent. Otherwise detaching could close the
591 auto target_ref
= target_ops_ref::new_reference (target
);
593 /* If we're vforking, we want to hold on to the parent until
594 the child exits or execs. At child exec or exit time we
595 can remove the old breakpoints from the parent and detach
596 or resume debugging it. Otherwise, detach the parent now;
597 we'll want to reuse it's program/address spaces, but we
598 can't set them to the child before removing breakpoints
599 from the parent, otherwise, the breakpoints module could
600 decide to remove breakpoints from the wrong process (since
601 they'd be assigned to the same address space). */
605 gdb_assert (child_inf
->vfork_parent
== NULL
);
606 gdb_assert (parent_inf
->vfork_child
== NULL
);
607 child_inf
->vfork_parent
= parent_inf
;
608 child_inf
->pending_detach
= 0;
609 parent_inf
->vfork_child
= child_inf
;
610 parent_inf
->pending_detach
= detach_fork
;
611 parent_inf
->waiting_for_vfork_done
= 0;
613 else if (detach_fork
)
615 if (print_inferior_events
)
617 /* Ensure that we have a process ptid. */
618 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
620 target_terminal::ours_for_output ();
621 fprintf_filtered (gdb_stdlog
,
622 _("[Detaching after fork from "
624 target_pid_to_str (process_ptid
).c_str ());
627 target_detach (parent_inf
, 0);
631 /* Note that the detach above makes PARENT_INF dangling. */
633 /* Add the child thread to the appropriate lists, and switch
634 to this new thread, before cloning the program space, and
635 informing the solib layer about this new process. */
637 set_current_inferior (child_inf
);
638 push_target (target
);
641 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
643 /* If this is a vfork child, then the address-space is shared
644 with the parent. If we detached from the parent, then we can
645 reuse the parent's program/address spaces. */
646 if (has_vforked
|| detach_fork
)
648 child_inf
->pspace
= parent_pspace
;
649 child_inf
->aspace
= child_inf
->pspace
->aspace
;
655 child_inf
->aspace
= new_address_space ();
656 child_inf
->pspace
= new program_space (child_inf
->aspace
);
657 child_inf
->removable
= 1;
658 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
659 set_current_program_space (child_inf
->pspace
);
660 clone_program_space (child_inf
->pspace
, parent_pspace
);
662 /* Let the shared library layer (e.g., solib-svr4) learn
663 about this new process, relocate the cloned exec, pull in
664 shared libraries, and install the solib event breakpoint.
665 If a "cloned-VM" event was propagated better throughout
666 the core, this wouldn't be required. */
667 solib_create_inferior_hook (0);
670 switch_to_thread (child_thr
);
673 return target_follow_fork (follow_child
, detach_fork
);
676 /* Tell the target to follow the fork we're stopped at. Returns true
677 if the inferior should be resumed; false, if the target for some
678 reason decided it's best not to resume. */
683 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
684 bool should_resume
= true;
685 struct thread_info
*tp
;
687 /* Copy user stepping state to the new inferior thread. FIXME: the
688 followed fork child thread should have a copy of most of the
689 parent thread structure's run control related fields, not just these.
690 Initialized to avoid "may be used uninitialized" warnings from gcc. */
691 struct breakpoint
*step_resume_breakpoint
= NULL
;
692 struct breakpoint
*exception_resume_breakpoint
= NULL
;
693 CORE_ADDR step_range_start
= 0;
694 CORE_ADDR step_range_end
= 0;
695 int current_line
= 0;
696 symtab
*current_symtab
= NULL
;
697 struct frame_id step_frame_id
= { 0 };
698 struct thread_fsm
*thread_fsm
= NULL
;
702 process_stratum_target
*wait_target
;
704 struct target_waitstatus wait_status
;
706 /* Get the last target status returned by target_wait(). */
707 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
709 /* If not stopped at a fork event, then there's nothing else to
711 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
712 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
715 /* Check if we switched over from WAIT_PTID, since the event was
717 if (wait_ptid
!= minus_one_ptid
718 && (current_inferior ()->process_target () != wait_target
719 || inferior_ptid
!= wait_ptid
))
721 /* We did. Switch back to WAIT_PTID thread, to tell the
722 target to follow it (in either direction). We'll
723 afterwards refuse to resume, and inform the user what
725 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
726 switch_to_thread (wait_thread
);
727 should_resume
= false;
731 tp
= inferior_thread ();
733 /* If there were any forks/vforks that were caught and are now to be
734 followed, then do so now. */
735 switch (tp
->pending_follow
.kind
)
737 case TARGET_WAITKIND_FORKED
:
738 case TARGET_WAITKIND_VFORKED
:
740 ptid_t parent
, child
;
742 /* If the user did a next/step, etc, over a fork call,
743 preserve the stepping state in the fork child. */
744 if (follow_child
&& should_resume
)
746 step_resume_breakpoint
= clone_momentary_breakpoint
747 (tp
->control
.step_resume_breakpoint
);
748 step_range_start
= tp
->control
.step_range_start
;
749 step_range_end
= tp
->control
.step_range_end
;
750 current_line
= tp
->current_line
;
751 current_symtab
= tp
->current_symtab
;
752 step_frame_id
= tp
->control
.step_frame_id
;
753 exception_resume_breakpoint
754 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
755 thread_fsm
= tp
->thread_fsm
;
757 /* For now, delete the parent's sr breakpoint, otherwise,
758 parent/child sr breakpoints are considered duplicates,
759 and the child version will not be installed. Remove
760 this when the breakpoints module becomes aware of
761 inferiors and address spaces. */
762 delete_step_resume_breakpoint (tp
);
763 tp
->control
.step_range_start
= 0;
764 tp
->control
.step_range_end
= 0;
765 tp
->control
.step_frame_id
= null_frame_id
;
766 delete_exception_resume_breakpoint (tp
);
767 tp
->thread_fsm
= NULL
;
770 parent
= inferior_ptid
;
771 child
= tp
->pending_follow
.value
.related_pid
;
773 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
774 /* Set up inferior(s) as specified by the caller, and tell the
775 target to do whatever is necessary to follow either parent
777 if (follow_fork_inferior (follow_child
, detach_fork
))
779 /* Target refused to follow, or there's some other reason
780 we shouldn't resume. */
785 /* This pending follow fork event is now handled, one way
786 or another. The previous selected thread may be gone
787 from the lists by now, but if it is still around, need
788 to clear the pending follow request. */
789 tp
= find_thread_ptid (parent_targ
, parent
);
791 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
793 /* This makes sure we don't try to apply the "Switched
794 over from WAIT_PID" logic above. */
795 nullify_last_target_wait_ptid ();
797 /* If we followed the child, switch to it... */
800 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
801 switch_to_thread (child_thr
);
803 /* ... and preserve the stepping state, in case the
804 user was stepping over the fork call. */
807 tp
= inferior_thread ();
808 tp
->control
.step_resume_breakpoint
809 = step_resume_breakpoint
;
810 tp
->control
.step_range_start
= step_range_start
;
811 tp
->control
.step_range_end
= step_range_end
;
812 tp
->current_line
= current_line
;
813 tp
->current_symtab
= current_symtab
;
814 tp
->control
.step_frame_id
= step_frame_id
;
815 tp
->control
.exception_resume_breakpoint
816 = exception_resume_breakpoint
;
817 tp
->thread_fsm
= thread_fsm
;
821 /* If we get here, it was because we're trying to
822 resume from a fork catchpoint, but, the user
823 has switched threads away from the thread that
824 forked. In that case, the resume command
825 issued is most likely not applicable to the
826 child, so just warn, and refuse to resume. */
827 warning (_("Not resuming: switched threads "
828 "before following fork child."));
831 /* Reset breakpoints in the child as appropriate. */
832 follow_inferior_reset_breakpoints ();
837 case TARGET_WAITKIND_SPURIOUS
:
838 /* Nothing to follow. */
841 internal_error (__FILE__
, __LINE__
,
842 "Unexpected pending_follow.kind %d\n",
843 tp
->pending_follow
.kind
);
847 return should_resume
;
851 follow_inferior_reset_breakpoints (void)
853 struct thread_info
*tp
= inferior_thread ();
855 /* Was there a step_resume breakpoint? (There was if the user
856 did a "next" at the fork() call.) If so, explicitly reset its
857 thread number. Cloned step_resume breakpoints are disabled on
858 creation, so enable it here now that it is associated with the
861 step_resumes are a form of bp that are made to be per-thread.
862 Since we created the step_resume bp when the parent process
863 was being debugged, and now are switching to the child process,
864 from the breakpoint package's viewpoint, that's a switch of
865 "threads". We must update the bp's notion of which thread
866 it is for, or it'll be ignored when it triggers. */
868 if (tp
->control
.step_resume_breakpoint
)
870 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
871 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
874 /* Treat exception_resume breakpoints like step_resume breakpoints. */
875 if (tp
->control
.exception_resume_breakpoint
)
877 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
878 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
881 /* Reinsert all breakpoints in the child. The user may have set
882 breakpoints after catching the fork, in which case those
883 were never set in the child, but only in the parent. This makes
884 sure the inserted breakpoints match the breakpoint list. */
886 breakpoint_re_set ();
887 insert_breakpoints ();
890 /* The child has exited or execed: resume threads of the parent the
891 user wanted to be executing. */
894 proceed_after_vfork_done (struct thread_info
*thread
,
897 int pid
= * (int *) arg
;
899 if (thread
->ptid
.pid () == pid
900 && thread
->state
== THREAD_RUNNING
901 && !thread
->executing
902 && !thread
->stop_requested
903 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
905 infrun_debug_printf ("resuming vfork parent thread %s",
906 target_pid_to_str (thread
->ptid
).c_str ());
908 switch_to_thread (thread
);
909 clear_proceed_status (0);
910 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
916 /* Called whenever we notice an exec or exit event, to handle
917 detaching or resuming a vfork parent. */
920 handle_vfork_child_exec_or_exit (int exec
)
922 struct inferior
*inf
= current_inferior ();
924 if (inf
->vfork_parent
)
926 int resume_parent
= -1;
928 /* This exec or exit marks the end of the shared memory region
929 between the parent and the child. Break the bonds. */
930 inferior
*vfork_parent
= inf
->vfork_parent
;
931 inf
->vfork_parent
->vfork_child
= NULL
;
932 inf
->vfork_parent
= NULL
;
934 /* If the user wanted to detach from the parent, now is the
936 if (vfork_parent
->pending_detach
)
938 struct program_space
*pspace
;
939 struct address_space
*aspace
;
941 /* follow-fork child, detach-on-fork on. */
943 vfork_parent
->pending_detach
= 0;
945 scoped_restore_current_pspace_and_thread restore_thread
;
947 /* We're letting loose of the parent. */
948 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
949 switch_to_thread (tp
);
951 /* We're about to detach from the parent, which implicitly
952 removes breakpoints from its address space. There's a
953 catch here: we want to reuse the spaces for the child,
954 but, parent/child are still sharing the pspace at this
955 point, although the exec in reality makes the kernel give
956 the child a fresh set of new pages. The problem here is
957 that the breakpoints module being unaware of this, would
958 likely chose the child process to write to the parent
959 address space. Swapping the child temporarily away from
960 the spaces has the desired effect. Yes, this is "sort
963 pspace
= inf
->pspace
;
964 aspace
= inf
->aspace
;
968 if (print_inferior_events
)
971 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
973 target_terminal::ours_for_output ();
977 fprintf_filtered (gdb_stdlog
,
978 _("[Detaching vfork parent %s "
979 "after child exec]\n"), pidstr
.c_str ());
983 fprintf_filtered (gdb_stdlog
,
984 _("[Detaching vfork parent %s "
985 "after child exit]\n"), pidstr
.c_str ());
989 target_detach (vfork_parent
, 0);
992 inf
->pspace
= pspace
;
993 inf
->aspace
= aspace
;
997 /* We're staying attached to the parent, so, really give the
998 child a new address space. */
999 inf
->pspace
= new program_space (maybe_new_address_space ());
1000 inf
->aspace
= inf
->pspace
->aspace
;
1002 set_current_program_space (inf
->pspace
);
1004 resume_parent
= vfork_parent
->pid
;
1008 /* If this is a vfork child exiting, then the pspace and
1009 aspaces were shared with the parent. Since we're
1010 reporting the process exit, we'll be mourning all that is
1011 found in the address space, and switching to null_ptid,
1012 preparing to start a new inferior. But, since we don't
1013 want to clobber the parent's address/program spaces, we
1014 go ahead and create a new one for this exiting
1017 /* Switch to no-thread while running clone_program_space, so
1018 that clone_program_space doesn't want to read the
1019 selected frame of a dead process. */
1020 scoped_restore_current_thread restore_thread
;
1021 switch_to_no_thread ();
1023 inf
->pspace
= new program_space (maybe_new_address_space ());
1024 inf
->aspace
= inf
->pspace
->aspace
;
1025 set_current_program_space (inf
->pspace
);
1027 inf
->symfile_flags
= SYMFILE_NO_READ
;
1028 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1030 resume_parent
= vfork_parent
->pid
;
1033 gdb_assert (current_program_space
== inf
->pspace
);
1035 if (non_stop
&& resume_parent
!= -1)
1037 /* If the user wanted the parent to be running, let it go
1039 scoped_restore_current_thread restore_thread
;
1041 infrun_debug_printf ("resuming vfork parent process %d",
1044 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1049 /* Enum strings for "set|show follow-exec-mode". */
1051 static const char follow_exec_mode_new
[] = "new";
1052 static const char follow_exec_mode_same
[] = "same";
1053 static const char *const follow_exec_mode_names
[] =
1055 follow_exec_mode_new
,
1056 follow_exec_mode_same
,
1060 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1062 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1063 struct cmd_list_element
*c
, const char *value
)
1065 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1068 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1071 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1073 struct inferior
*inf
= current_inferior ();
1074 int pid
= ptid
.pid ();
1075 ptid_t process_ptid
;
1077 /* Switch terminal for any messages produced e.g. by
1078 breakpoint_re_set. */
1079 target_terminal::ours_for_output ();
1081 /* This is an exec event that we actually wish to pay attention to.
1082 Refresh our symbol table to the newly exec'd program, remove any
1083 momentary bp's, etc.
1085 If there are breakpoints, they aren't really inserted now,
1086 since the exec() transformed our inferior into a fresh set
1089 We want to preserve symbolic breakpoints on the list, since
1090 we have hopes that they can be reset after the new a.out's
1091 symbol table is read.
1093 However, any "raw" breakpoints must be removed from the list
1094 (e.g., the solib bp's), since their address is probably invalid
1097 And, we DON'T want to call delete_breakpoints() here, since
1098 that may write the bp's "shadow contents" (the instruction
1099 value that was overwritten with a TRAP instruction). Since
1100 we now have a new a.out, those shadow contents aren't valid. */
1102 mark_breakpoints_out ();
1104 /* The target reports the exec event to the main thread, even if
1105 some other thread does the exec, and even if the main thread was
1106 stopped or already gone. We may still have non-leader threads of
1107 the process on our list. E.g., on targets that don't have thread
1108 exit events (like remote); or on native Linux in non-stop mode if
1109 there were only two threads in the inferior and the non-leader
1110 one is the one that execs (and nothing forces an update of the
1111 thread list up to here). When debugging remotely, it's best to
1112 avoid extra traffic, when possible, so avoid syncing the thread
1113 list with the target, and instead go ahead and delete all threads
1114 of the process but one that reported the event. Note this must
1115 be done before calling update_breakpoints_after_exec, as
1116 otherwise clearing the threads' resources would reference stale
1117 thread breakpoints -- it may have been one of these threads that
1118 stepped across the exec. We could just clear their stepping
1119 states, but as long as we're iterating, might as well delete
1120 them. Deleting them now rather than at the next user-visible
1121 stop provides a nicer sequence of events for user and MI
1123 for (thread_info
*th
: all_threads_safe ())
1124 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1127 /* We also need to clear any left over stale state for the
1128 leader/event thread. E.g., if there was any step-resume
1129 breakpoint or similar, it's gone now. We cannot truly
1130 step-to-next statement through an exec(). */
1131 thread_info
*th
= inferior_thread ();
1132 th
->control
.step_resume_breakpoint
= NULL
;
1133 th
->control
.exception_resume_breakpoint
= NULL
;
1134 th
->control
.single_step_breakpoints
= NULL
;
1135 th
->control
.step_range_start
= 0;
1136 th
->control
.step_range_end
= 0;
1138 /* The user may have had the main thread held stopped in the
1139 previous image (e.g., schedlock on, or non-stop). Release
1141 th
->stop_requested
= 0;
1143 update_breakpoints_after_exec ();
1145 /* What is this a.out's name? */
1146 process_ptid
= ptid_t (pid
);
1147 printf_unfiltered (_("%s is executing new program: %s\n"),
1148 target_pid_to_str (process_ptid
).c_str (),
1151 /* We've followed the inferior through an exec. Therefore, the
1152 inferior has essentially been killed & reborn. */
1154 breakpoint_init_inferior (inf_execd
);
1156 gdb::unique_xmalloc_ptr
<char> exec_file_host
1157 = exec_file_find (exec_file_target
, NULL
);
1159 /* If we were unable to map the executable target pathname onto a host
1160 pathname, tell the user that. Otherwise GDB's subsequent behavior
1161 is confusing. Maybe it would even be better to stop at this point
1162 so that the user can specify a file manually before continuing. */
1163 if (exec_file_host
== NULL
)
1164 warning (_("Could not load symbols for executable %s.\n"
1165 "Do you need \"set sysroot\"?"),
1168 /* Reset the shared library package. This ensures that we get a
1169 shlib event when the child reaches "_start", at which point the
1170 dld will have had a chance to initialize the child. */
1171 /* Also, loading a symbol file below may trigger symbol lookups, and
1172 we don't want those to be satisfied by the libraries of the
1173 previous incarnation of this process. */
1174 no_shared_libraries (NULL
, 0);
1176 if (follow_exec_mode_string
== follow_exec_mode_new
)
1178 /* The user wants to keep the old inferior and program spaces
1179 around. Create a new fresh one, and switch to it. */
1181 /* Do exit processing for the original inferior before setting the new
1182 inferior's pid. Having two inferiors with the same pid would confuse
1183 find_inferior_p(t)id. Transfer the terminal state and info from the
1184 old to the new inferior. */
1185 inf
= add_inferior_with_spaces ();
1186 swap_terminal_info (inf
, current_inferior ());
1187 exit_inferior_silent (current_inferior ());
1190 target_follow_exec (inf
, exec_file_target
);
1192 inferior
*org_inferior
= current_inferior ();
1193 switch_to_inferior_no_thread (inf
);
1194 push_target (org_inferior
->process_target ());
1195 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1196 switch_to_thread (thr
);
1200 /* The old description may no longer be fit for the new image.
1201 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1202 old description; we'll read a new one below. No need to do
1203 this on "follow-exec-mode new", as the old inferior stays
1204 around (its description is later cleared/refetched on
1206 target_clear_description ();
1209 gdb_assert (current_program_space
== inf
->pspace
);
1211 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1212 because the proper displacement for a PIE (Position Independent
1213 Executable) main symbol file will only be computed by
1214 solib_create_inferior_hook below. breakpoint_re_set would fail
1215 to insert the breakpoints with the zero displacement. */
1216 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1218 /* If the target can specify a description, read it. Must do this
1219 after flipping to the new executable (because the target supplied
1220 description must be compatible with the executable's
1221 architecture, and the old executable may e.g., be 32-bit, while
1222 the new one 64-bit), and before anything involving memory or
1224 target_find_description ();
1226 gdb::observers::inferior_execd
.notify (inf
);
1228 breakpoint_re_set ();
1230 /* Reinsert all breakpoints. (Those which were symbolic have
1231 been reset to the proper address in the new a.out, thanks
1232 to symbol_file_command...). */
1233 insert_breakpoints ();
1235 /* The next resume of this inferior should bring it to the shlib
1236 startup breakpoints. (If the user had also set bp's on
1237 "main" from the old (parent) process, then they'll auto-
1238 matically get reset there in the new process.). */
1241 /* The chain of threads that need to do a step-over operation to get
1242 past e.g., a breakpoint. What technique is used to step over the
1243 breakpoint/watchpoint does not matter -- all threads end up in the
1244 same queue, to maintain rough temporal order of execution, in order
1245 to avoid starvation, otherwise, we could e.g., find ourselves
1246 constantly stepping the same couple threads past their breakpoints
1247 over and over, if the single-step finish fast enough. */
1248 struct thread_info
*global_thread_step_over_chain_head
;
1250 /* Bit flags indicating what the thread needs to step over. */
1252 enum step_over_what_flag
1254 /* Step over a breakpoint. */
1255 STEP_OVER_BREAKPOINT
= 1,
1257 /* Step past a non-continuable watchpoint, in order to let the
1258 instruction execute so we can evaluate the watchpoint
1260 STEP_OVER_WATCHPOINT
= 2
1262 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1264 /* Info about an instruction that is being stepped over. */
1266 struct step_over_info
1268 /* If we're stepping past a breakpoint, this is the address space
1269 and address of the instruction the breakpoint is set at. We'll
1270 skip inserting all breakpoints here. Valid iff ASPACE is
1272 const address_space
*aspace
;
1275 /* The instruction being stepped over triggers a nonsteppable
1276 watchpoint. If true, we'll skip inserting watchpoints. */
1277 int nonsteppable_watchpoint_p
;
1279 /* The thread's global number. */
1283 /* The step-over info of the location that is being stepped over.
1285 Note that with async/breakpoint always-inserted mode, a user might
1286 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1287 being stepped over. As setting a new breakpoint inserts all
1288 breakpoints, we need to make sure the breakpoint being stepped over
1289 isn't inserted then. We do that by only clearing the step-over
1290 info when the step-over is actually finished (or aborted).
1292 Presently GDB can only step over one breakpoint at any given time.
1293 Given threads that can't run code in the same address space as the
1294 breakpoint's can't really miss the breakpoint, GDB could be taught
1295 to step-over at most one breakpoint per address space (so this info
1296 could move to the address space object if/when GDB is extended).
1297 The set of breakpoints being stepped over will normally be much
1298 smaller than the set of all breakpoints, so a flag in the
1299 breakpoint location structure would be wasteful. A separate list
1300 also saves complexity and run-time, as otherwise we'd have to go
1301 through all breakpoint locations clearing their flag whenever we
1302 start a new sequence. Similar considerations weigh against storing
1303 this info in the thread object. Plus, not all step overs actually
1304 have breakpoint locations -- e.g., stepping past a single-step
1305 breakpoint, or stepping to complete a non-continuable
1307 static struct step_over_info step_over_info
;
1309 /* Record the address of the breakpoint/instruction we're currently
1311 N.B. We record the aspace and address now, instead of say just the thread,
1312 because when we need the info later the thread may be running. */
1315 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1316 int nonsteppable_watchpoint_p
,
1319 step_over_info
.aspace
= aspace
;
1320 step_over_info
.address
= address
;
1321 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1322 step_over_info
.thread
= thread
;
1325 /* Called when we're not longer stepping over a breakpoint / an
1326 instruction, so all breakpoints are free to be (re)inserted. */
1329 clear_step_over_info (void)
1331 infrun_debug_printf ("clearing step over info");
1332 step_over_info
.aspace
= NULL
;
1333 step_over_info
.address
= 0;
1334 step_over_info
.nonsteppable_watchpoint_p
= 0;
1335 step_over_info
.thread
= -1;
1341 stepping_past_instruction_at (struct address_space
*aspace
,
1344 return (step_over_info
.aspace
!= NULL
1345 && breakpoint_address_match (aspace
, address
,
1346 step_over_info
.aspace
,
1347 step_over_info
.address
));
1353 thread_is_stepping_over_breakpoint (int thread
)
1355 return (step_over_info
.thread
!= -1
1356 && thread
== step_over_info
.thread
);
1362 stepping_past_nonsteppable_watchpoint (void)
1364 return step_over_info
.nonsteppable_watchpoint_p
;
1367 /* Returns true if step-over info is valid. */
1370 step_over_info_valid_p (void)
1372 return (step_over_info
.aspace
!= NULL
1373 || stepping_past_nonsteppable_watchpoint ());
1377 /* Displaced stepping. */
1379 /* In non-stop debugging mode, we must take special care to manage
1380 breakpoints properly; in particular, the traditional strategy for
1381 stepping a thread past a breakpoint it has hit is unsuitable.
1382 'Displaced stepping' is a tactic for stepping one thread past a
1383 breakpoint it has hit while ensuring that other threads running
1384 concurrently will hit the breakpoint as they should.
1386 The traditional way to step a thread T off a breakpoint in a
1387 multi-threaded program in all-stop mode is as follows:
1389 a0) Initially, all threads are stopped, and breakpoints are not
1391 a1) We single-step T, leaving breakpoints uninserted.
1392 a2) We insert breakpoints, and resume all threads.
1394 In non-stop debugging, however, this strategy is unsuitable: we
1395 don't want to have to stop all threads in the system in order to
1396 continue or step T past a breakpoint. Instead, we use displaced
1399 n0) Initially, T is stopped, other threads are running, and
1400 breakpoints are inserted.
1401 n1) We copy the instruction "under" the breakpoint to a separate
1402 location, outside the main code stream, making any adjustments
1403 to the instruction, register, and memory state as directed by
1405 n2) We single-step T over the instruction at its new location.
1406 n3) We adjust the resulting register and memory state as directed
1407 by T's architecture. This includes resetting T's PC to point
1408 back into the main instruction stream.
1411 This approach depends on the following gdbarch methods:
1413 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1414 indicate where to copy the instruction, and how much space must
1415 be reserved there. We use these in step n1.
1417 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1418 address, and makes any necessary adjustments to the instruction,
1419 register contents, and memory. We use this in step n1.
1421 - gdbarch_displaced_step_fixup adjusts registers and memory after
1422 we have successfully single-stepped the instruction, to yield the
1423 same effect the instruction would have had if we had executed it
1424 at its original address. We use this in step n3.
1426 The gdbarch_displaced_step_copy_insn and
1427 gdbarch_displaced_step_fixup functions must be written so that
1428 copying an instruction with gdbarch_displaced_step_copy_insn,
1429 single-stepping across the copied instruction, and then applying
1430 gdbarch_displaced_insn_fixup should have the same effects on the
1431 thread's memory and registers as stepping the instruction in place
1432 would have. Exactly which responsibilities fall to the copy and
1433 which fall to the fixup is up to the author of those functions.
1435 See the comments in gdbarch.sh for details.
1437 Note that displaced stepping and software single-step cannot
1438 currently be used in combination, although with some care I think
1439 they could be made to. Software single-step works by placing
1440 breakpoints on all possible subsequent instructions; if the
1441 displaced instruction is a PC-relative jump, those breakpoints
1442 could fall in very strange places --- on pages that aren't
1443 executable, or at addresses that are not proper instruction
1444 boundaries. (We do generally let other threads run while we wait
1445 to hit the software single-step breakpoint, and they might
1446 encounter such a corrupted instruction.) One way to work around
1447 this would be to have gdbarch_displaced_step_copy_insn fully
1448 simulate the effect of PC-relative instructions (and return NULL)
1449 on architectures that use software single-stepping.
1451 In non-stop mode, we can have independent and simultaneous step
1452 requests, so more than one thread may need to simultaneously step
1453 over a breakpoint. The current implementation assumes there is
1454 only one scratch space per process. In this case, we have to
1455 serialize access to the scratch space. If thread A wants to step
1456 over a breakpoint, but we are currently waiting for some other
1457 thread to complete a displaced step, we leave thread A stopped and
1458 place it in the displaced_step_request_queue. Whenever a displaced
1459 step finishes, we pick the next thread in the queue and start a new
1460 displaced step operation on it. See displaced_step_prepare and
1461 displaced_step_finish for details. */
1463 /* Default destructor for displaced_step_copy_insn_closure. */
1465 displaced_step_copy_insn_closure::~displaced_step_copy_insn_closure ()
1468 /* Returns true if any inferior has a thread doing a displaced
1472 displaced_step_in_progress_any_inferior ()
1474 for (inferior
*i
: all_inferiors ())
1476 if (i
->displaced_step_state
.step_thread
!= nullptr)
1483 /* Return true if THREAD is doing a displaced step. */
1486 displaced_step_in_progress_thread (thread_info
*thread
)
1488 gdb_assert (thread
!= NULL
);
1490 return thread
->inf
->displaced_step_state
.step_thread
== thread
;
1493 /* Return true if INF has a thread doing a displaced step. */
1496 displaced_step_in_progress (inferior
*inf
)
1498 return inf
->displaced_step_state
.step_thread
!= nullptr;
1501 /* If inferior is in displaced stepping, and ADDR equals to starting address
1502 of copy area, return corresponding displaced_step_copy_insn_closure.
1503 Otherwise, return NULL. */
1505 displaced_step_copy_insn_closure
*
1506 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1508 displaced_step_inferior_state
&displaced
1509 = current_inferior ()->displaced_step_state
;
1511 /* If checking the mode of displaced instruction in copy area. */
1512 if (displaced
.step_thread
!= nullptr
1513 && displaced
.step_copy
== addr
)
1514 return displaced
.step_closure
.get ();
1520 infrun_inferior_exit (struct inferior
*inf
)
1522 inf
->displaced_step_state
.reset ();
1526 infrun_inferior_execd (inferior
*inf
)
1528 /* If a thread was doing a displaced step in this inferior at the moment of
1529 the exec, it no longer exists. Even if the exec'ing thread was the one
1530 doing a displaced step, we don't want to to any fixup nor restore displaced
1531 stepping buffer bytes. */
1532 inf
->displaced_step_state
.reset ();
1534 /* Since an in-line step is done with everything else stopped, if there was
1535 one in progress at the time of the exec, it must have been the exec'ing
1537 clear_step_over_info ();
1540 /* If ON, and the architecture supports it, GDB will use displaced
1541 stepping to step over breakpoints. If OFF, or if the architecture
1542 doesn't support it, GDB will instead use the traditional
1543 hold-and-step approach. If AUTO (which is the default), GDB will
1544 decide which technique to use to step over breakpoints depending on
1545 whether the target works in a non-stop way (see use_displaced_stepping). */
1547 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1550 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1551 struct cmd_list_element
*c
,
1554 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1555 fprintf_filtered (file
,
1556 _("Debugger's willingness to use displaced stepping "
1557 "to step over breakpoints is %s (currently %s).\n"),
1558 value
, target_is_non_stop_p () ? "on" : "off");
1560 fprintf_filtered (file
,
1561 _("Debugger's willingness to use displaced stepping "
1562 "to step over breakpoints is %s.\n"), value
);
1565 /* Return true if the gdbarch implements the required methods to use
1566 displaced stepping. */
1569 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1571 /* Only check for the presence of step_copy_insn. Other required methods
1572 are checked by the gdbarch validation. */
1573 return gdbarch_displaced_step_copy_insn_p (arch
);
1576 /* Return non-zero if displaced stepping can/should be used to step
1577 over breakpoints of thread TP. */
1580 use_displaced_stepping (thread_info
*tp
)
1582 /* If the user disabled it explicitly, don't use displaced stepping. */
1583 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1586 /* If "auto", only use displaced stepping if the target operates in a non-stop
1588 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1589 && !target_is_non_stop_p ())
1592 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1594 /* If the architecture doesn't implement displaced stepping, don't use
1596 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1599 /* If recording, don't use displaced stepping. */
1600 if (find_record_target () != nullptr)
1603 /* If displaced stepping failed before for this inferior, don't bother trying
1605 if (tp
->inf
->displaced_step_state
.failed_before
)
1611 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1614 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1616 displaced
->reset ();
1619 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1620 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1622 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1627 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1631 for (size_t i
= 0; i
< len
; i
++)
1634 ret
+= string_printf ("%02x", buf
[i
]);
1636 ret
+= string_printf (" %02x", buf
[i
]);
1642 /* Prepare to single-step, using displaced stepping.
1644 Note that we cannot use displaced stepping when we have a signal to
1645 deliver. If we have a signal to deliver and an instruction to step
1646 over, then after the step, there will be no indication from the
1647 target whether the thread entered a signal handler or ignored the
1648 signal and stepped over the instruction successfully --- both cases
1649 result in a simple SIGTRAP. In the first case we mustn't do a
1650 fixup, and in the second case we must --- but we can't tell which.
1651 Comments in the code for 'random signals' in handle_inferior_event
1652 explain how we handle this case instead.
1654 Returns DISPLACED_STEP_PREPARE_STATUS_OK if preparing was successful -- this
1655 thread is going to be stepped now; DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
1656 if displaced stepping this thread got queued; or
1657 DISPLACED_STEP_PREPARE_STATUS_CANT if this instruction can't be displaced
1660 static displaced_step_prepare_status
1661 displaced_step_prepare_throw (thread_info
*tp
)
1663 regcache
*regcache
= get_thread_regcache (tp
);
1664 struct gdbarch
*gdbarch
= regcache
->arch ();
1665 const address_space
*aspace
= regcache
->aspace ();
1666 CORE_ADDR original
, copy
;
1670 /* We should never reach this function if the architecture does not
1671 support displaced stepping. */
1672 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1674 /* Nor if the thread isn't meant to step over a breakpoint. */
1675 gdb_assert (tp
->control
.trap_expected
);
1677 /* Disable range stepping while executing in the scratch pad. We
1678 want a single-step even if executing the displaced instruction in
1679 the scratch buffer lands within the stepping range (e.g., a
1681 tp
->control
.may_range_step
= 0;
1683 /* We have to displaced step one thread at a time, as we only have
1684 access to a single scratch space per inferior. */
1686 displaced_step_inferior_state
*displaced
= &tp
->inf
->displaced_step_state
;
1688 if (displaced
->step_thread
!= nullptr)
1690 /* Already waiting for a displaced step to finish. Defer this
1691 request and place in queue. */
1693 displaced_debug_printf ("deferring step of %s",
1694 target_pid_to_str (tp
->ptid
).c_str ());
1696 global_thread_step_over_chain_enqueue (tp
);
1697 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1700 displaced_debug_printf ("stepping %s now",
1701 target_pid_to_str (tp
->ptid
).c_str ());
1703 displaced_step_reset (displaced
);
1705 scoped_restore_current_thread restore_thread
;
1707 switch_to_thread (tp
);
1709 original
= regcache_read_pc (regcache
);
1711 copy
= gdbarch_displaced_step_location (gdbarch
);
1712 len
= gdbarch_max_insn_length (gdbarch
);
1714 if (breakpoint_in_range_p (aspace
, copy
, len
))
1716 /* There's a breakpoint set in the scratch pad location range
1717 (which is usually around the entry point). We'd either
1718 install it before resuming, which would overwrite/corrupt the
1719 scratch pad, or if it was already inserted, this displaced
1720 step would overwrite it. The latter is OK in the sense that
1721 we already assume that no thread is going to execute the code
1722 in the scratch pad range (after initial startup) anyway, but
1723 the former is unacceptable. Simply punt and fallback to
1724 stepping over this breakpoint in-line. */
1725 displaced_debug_printf ("breakpoint set in scratch pad. "
1726 "Stepping over breakpoint in-line instead.");
1728 return DISPLACED_STEP_PREPARE_STATUS_CANT
;
1731 /* Save the original contents of the copy area. */
1732 displaced
->step_saved_copy
.resize (len
);
1733 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1735 throw_error (MEMORY_ERROR
,
1736 _("Error accessing memory address %s (%s) for "
1737 "displaced-stepping scratch space."),
1738 paddress (gdbarch
, copy
), safe_strerror (status
));
1740 displaced_debug_printf ("saved %s: %s",
1741 paddress (gdbarch
, copy
),
1742 displaced_step_dump_bytes
1743 (displaced
->step_saved_copy
.data (), len
).c_str ());
1745 displaced
->step_closure
1746 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1747 if (displaced
->step_closure
== NULL
)
1749 /* The architecture doesn't know how or want to displaced step
1750 this instruction or instruction sequence. Fallback to
1751 stepping over the breakpoint in-line. */
1752 return DISPLACED_STEP_PREPARE_STATUS_CANT
;
1755 /* Save the information we need to fix things up if the step
1757 displaced
->step_thread
= tp
;
1758 displaced
->step_gdbarch
= gdbarch
;
1759 displaced
->step_original
= original
;
1760 displaced
->step_copy
= copy
;
1763 displaced_step_reset_cleanup
cleanup (displaced
);
1765 /* Resume execution at the copy. */
1766 regcache_write_pc (regcache
, copy
);
1771 displaced_debug_printf ("displaced pc to %s", paddress (gdbarch
, copy
));
1773 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1776 /* Wrapper for displaced_step_prepare_throw that disabled further
1777 attempts at displaced stepping if we get a memory error. */
1779 static displaced_step_prepare_status
1780 displaced_step_prepare (thread_info
*thread
)
1782 displaced_step_prepare_status status
1783 = DISPLACED_STEP_PREPARE_STATUS_CANT
;
1787 status
= displaced_step_prepare_throw (thread
);
1789 catch (const gdb_exception_error
&ex
)
1791 if (ex
.error
!= MEMORY_ERROR
1792 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1795 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1798 /* Be verbose if "set displaced-stepping" is "on", silent if
1800 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1802 warning (_("disabling displaced stepping: %s"),
1806 /* Disable further displaced stepping attempts. */
1807 thread
->inf
->displaced_step_state
.failed_before
= 1;
1814 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1815 const gdb_byte
*myaddr
, int len
)
1817 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1819 inferior_ptid
= ptid
;
1820 write_memory (memaddr
, myaddr
, len
);
1823 /* Restore the contents of the copy area for thread PTID. */
1826 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1829 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1831 write_memory_ptid (ptid
, displaced
->step_copy
,
1832 displaced
->step_saved_copy
.data (), len
);
1834 displaced_debug_printf ("restored %s %s",
1835 target_pid_to_str (ptid
).c_str (),
1836 paddress (displaced
->step_gdbarch
,
1837 displaced
->step_copy
));
1840 /* If we displaced stepped an instruction successfully, adjust registers and
1841 memory to yield the same effect the instruction would have had if we had
1842 executed it at its original address, and return
1843 DISPLACED_STEP_FINISH_STATUS_OK. If the instruction didn't complete,
1844 relocate the PC and return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED.
1846 If the thread wasn't displaced stepping, return
1847 DISPLACED_STEP_FINISH_STATUS_OK as well. */
1849 static displaced_step_finish_status
1850 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1852 displaced_step_inferior_state
*displaced
1853 = &event_thread
->inf
->displaced_step_state
;
1855 /* Was this event for the thread we displaced? */
1856 if (displaced
->step_thread
!= event_thread
)
1857 return DISPLACED_STEP_FINISH_STATUS_OK
;
1859 /* Fixup may need to read memory/registers. Switch to the thread
1860 that we're fixing up. Also, target_stopped_by_watchpoint checks
1861 the current thread, and displaced_step_restore performs ptid-dependent
1862 memory accesses using current_inferior() and current_top_target(). */
1863 switch_to_thread (event_thread
);
1865 displaced_step_reset_cleanup
cleanup (displaced
);
1867 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1869 /* Did the instruction complete successfully? */
1870 if (signal
== GDB_SIGNAL_TRAP
1871 && !(target_stopped_by_watchpoint ()
1872 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1873 || target_have_steppable_watchpoint ())))
1875 /* Fix up the resulting state. */
1876 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1877 displaced
->step_closure
.get (),
1878 displaced
->step_original
,
1879 displaced
->step_copy
,
1880 get_thread_regcache (displaced
->step_thread
));
1882 return DISPLACED_STEP_FINISH_STATUS_OK
;
1886 /* Since the instruction didn't complete, all we can do is
1888 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1889 CORE_ADDR pc
= regcache_read_pc (regcache
);
1891 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1892 regcache_write_pc (regcache
, pc
);
1894 return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
;
1898 /* Data to be passed around while handling an event. This data is
1899 discarded between events. */
1900 struct execution_control_state
1902 process_stratum_target
*target
;
1904 /* The thread that got the event, if this was a thread event; NULL
1906 struct thread_info
*event_thread
;
1908 struct target_waitstatus ws
;
1909 int stop_func_filled_in
;
1910 CORE_ADDR stop_func_start
;
1911 CORE_ADDR stop_func_end
;
1912 const char *stop_func_name
;
1915 /* True if the event thread hit the single-step breakpoint of
1916 another thread. Thus the event doesn't cause a stop, the thread
1917 needs to be single-stepped past the single-step breakpoint before
1918 we can switch back to the original stepping thread. */
1919 int hit_singlestep_breakpoint
;
1922 /* Clear ECS and set it to point at TP. */
1925 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1927 memset (ecs
, 0, sizeof (*ecs
));
1928 ecs
->event_thread
= tp
;
1929 ecs
->ptid
= tp
->ptid
;
1932 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1933 static void prepare_to_wait (struct execution_control_state
*ecs
);
1934 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1935 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1937 /* Are there any pending step-over requests? If so, run all we can
1938 now and return true. Otherwise, return false. */
1941 start_step_over (void)
1943 struct thread_info
*tp
, *next
;
1945 /* Don't start a new step-over if we already have an in-line
1946 step-over operation ongoing. */
1947 if (step_over_info_valid_p ())
1950 for (tp
= global_thread_step_over_chain_head
; tp
!= NULL
; tp
= next
)
1952 struct execution_control_state ecss
;
1953 struct execution_control_state
*ecs
= &ecss
;
1954 step_over_what step_what
;
1955 int must_be_in_line
;
1957 gdb_assert (!tp
->stop_requested
);
1959 next
= global_thread_step_over_chain_next (tp
);
1961 /* If this inferior already has a displaced step in process,
1962 don't start a new one. */
1963 if (displaced_step_in_progress (tp
->inf
))
1966 step_what
= thread_still_needs_step_over (tp
);
1967 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1968 || ((step_what
& STEP_OVER_BREAKPOINT
)
1969 && !use_displaced_stepping (tp
)));
1971 /* We currently stop all threads of all processes to step-over
1972 in-line. If we need to start a new in-line step-over, let
1973 any pending displaced steps finish first. */
1974 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1977 global_thread_step_over_chain_remove (tp
);
1979 if (global_thread_step_over_chain_head
== NULL
)
1980 infrun_debug_printf ("step-over queue now empty");
1982 if (tp
->control
.trap_expected
1986 internal_error (__FILE__
, __LINE__
,
1987 "[%s] has inconsistent state: "
1988 "trap_expected=%d, resumed=%d, executing=%d\n",
1989 target_pid_to_str (tp
->ptid
).c_str (),
1990 tp
->control
.trap_expected
,
1995 infrun_debug_printf ("resuming [%s] for step-over",
1996 target_pid_to_str (tp
->ptid
).c_str ());
1998 /* keep_going_pass_signal skips the step-over if the breakpoint
1999 is no longer inserted. In all-stop, we want to keep looking
2000 for a thread that needs a step-over instead of resuming TP,
2001 because we wouldn't be able to resume anything else until the
2002 target stops again. In non-stop, the resume always resumes
2003 only TP, so it's OK to let the thread resume freely. */
2004 if (!target_is_non_stop_p () && !step_what
)
2007 switch_to_thread (tp
);
2008 reset_ecs (ecs
, tp
);
2009 keep_going_pass_signal (ecs
);
2011 if (!ecs
->wait_some_more
)
2012 error (_("Command aborted."));
2014 gdb_assert (tp
->resumed
);
2016 /* If we started a new in-line step-over, we're done. */
2017 if (step_over_info_valid_p ())
2019 gdb_assert (tp
->control
.trap_expected
);
2023 if (!target_is_non_stop_p ())
2025 /* On all-stop, shouldn't have resumed unless we needed a
2027 gdb_assert (tp
->control
.trap_expected
2028 || tp
->step_after_step_resume_breakpoint
);
2030 /* With remote targets (at least), in all-stop, we can't
2031 issue any further remote commands until the program stops
2036 /* Either the thread no longer needed a step-over, or a new
2037 displaced stepping sequence started. Even in the latter
2038 case, continue looking. Maybe we can also start another
2039 displaced step on a thread of other process. */
2045 /* Update global variables holding ptids to hold NEW_PTID if they were
2046 holding OLD_PTID. */
2048 infrun_thread_ptid_changed (process_stratum_target
*target
,
2049 ptid_t old_ptid
, ptid_t new_ptid
)
2051 if (inferior_ptid
== old_ptid
2052 && current_inferior ()->process_target () == target
)
2053 inferior_ptid
= new_ptid
;
2058 static const char schedlock_off
[] = "off";
2059 static const char schedlock_on
[] = "on";
2060 static const char schedlock_step
[] = "step";
2061 static const char schedlock_replay
[] = "replay";
2062 static const char *const scheduler_enums
[] = {
2069 static const char *scheduler_mode
= schedlock_replay
;
2071 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2072 struct cmd_list_element
*c
, const char *value
)
2074 fprintf_filtered (file
,
2075 _("Mode for locking scheduler "
2076 "during execution is \"%s\".\n"),
2081 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2083 if (!target_can_lock_scheduler ())
2085 scheduler_mode
= schedlock_off
;
2086 error (_("Target '%s' cannot support this command."), target_shortname
);
2090 /* True if execution commands resume all threads of all processes by
2091 default; otherwise, resume only threads of the current inferior
2093 bool sched_multi
= false;
2095 /* Try to setup for software single stepping over the specified location.
2096 Return true if target_resume() should use hardware single step.
2098 GDBARCH the current gdbarch.
2099 PC the location to step over. */
2102 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2104 bool hw_step
= true;
2106 if (execution_direction
== EXEC_FORWARD
2107 && gdbarch_software_single_step_p (gdbarch
))
2108 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2116 user_visible_resume_ptid (int step
)
2122 /* With non-stop mode on, threads are always handled
2124 resume_ptid
= inferior_ptid
;
2126 else if ((scheduler_mode
== schedlock_on
)
2127 || (scheduler_mode
== schedlock_step
&& step
))
2129 /* User-settable 'scheduler' mode requires solo thread
2131 resume_ptid
= inferior_ptid
;
2133 else if ((scheduler_mode
== schedlock_replay
)
2134 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2136 /* User-settable 'scheduler' mode requires solo thread resume in replay
2138 resume_ptid
= inferior_ptid
;
2140 else if (!sched_multi
&& target_supports_multi_process ())
2142 /* Resume all threads of the current process (and none of other
2144 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2148 /* Resume all threads of all processes. */
2149 resume_ptid
= RESUME_ALL
;
2157 process_stratum_target
*
2158 user_visible_resume_target (ptid_t resume_ptid
)
2160 return (resume_ptid
== minus_one_ptid
&& sched_multi
2162 : current_inferior ()->process_target ());
2165 /* Return a ptid representing the set of threads that we will resume,
2166 in the perspective of the target, assuming run control handling
2167 does not require leaving some threads stopped (e.g., stepping past
2168 breakpoint). USER_STEP indicates whether we're about to start the
2169 target for a stepping command. */
2172 internal_resume_ptid (int user_step
)
2174 /* In non-stop, we always control threads individually. Note that
2175 the target may always work in non-stop mode even with "set
2176 non-stop off", in which case user_visible_resume_ptid could
2177 return a wildcard ptid. */
2178 if (target_is_non_stop_p ())
2179 return inferior_ptid
;
2181 return user_visible_resume_ptid (user_step
);
2184 /* Wrapper for target_resume, that handles infrun-specific
2188 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2190 struct thread_info
*tp
= inferior_thread ();
2192 gdb_assert (!tp
->stop_requested
);
2194 /* Install inferior's terminal modes. */
2195 target_terminal::inferior ();
2197 /* Avoid confusing the next resume, if the next stop/resume
2198 happens to apply to another thread. */
2199 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2201 /* Advise target which signals may be handled silently.
2203 If we have removed breakpoints because we are stepping over one
2204 in-line (in any thread), we need to receive all signals to avoid
2205 accidentally skipping a breakpoint during execution of a signal
2208 Likewise if we're displaced stepping, otherwise a trap for a
2209 breakpoint in a signal handler might be confused with the
2210 displaced step finishing. We don't make the displaced_step_finish
2211 step distinguish the cases instead, because:
2213 - a backtrace while stopped in the signal handler would show the
2214 scratch pad as frame older than the signal handler, instead of
2215 the real mainline code.
2217 - when the thread is later resumed, the signal handler would
2218 return to the scratch pad area, which would no longer be
2220 if (step_over_info_valid_p ()
2221 || displaced_step_in_progress (tp
->inf
))
2222 target_pass_signals ({});
2224 target_pass_signals (signal_pass
);
2226 target_resume (resume_ptid
, step
, sig
);
2228 target_commit_resume ();
2230 if (target_can_async_p ())
2234 /* Resume the inferior. SIG is the signal to give the inferior
2235 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2236 call 'resume', which handles exceptions. */
2239 resume_1 (enum gdb_signal sig
)
2241 struct regcache
*regcache
= get_current_regcache ();
2242 struct gdbarch
*gdbarch
= regcache
->arch ();
2243 struct thread_info
*tp
= inferior_thread ();
2244 const address_space
*aspace
= regcache
->aspace ();
2246 /* This represents the user's step vs continue request. When
2247 deciding whether "set scheduler-locking step" applies, it's the
2248 user's intention that counts. */
2249 const int user_step
= tp
->control
.stepping_command
;
2250 /* This represents what we'll actually request the target to do.
2251 This can decay from a step to a continue, if e.g., we need to
2252 implement single-stepping with breakpoints (software
2256 gdb_assert (!tp
->stop_requested
);
2257 gdb_assert (!thread_is_in_step_over_chain (tp
));
2259 if (tp
->suspend
.waitstatus_pending_p
)
2262 ("thread %s has pending wait "
2263 "status %s (currently_stepping=%d).",
2264 target_pid_to_str (tp
->ptid
).c_str (),
2265 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2266 currently_stepping (tp
));
2268 tp
->inf
->process_target ()->threads_executing
= true;
2271 /* FIXME: What should we do if we are supposed to resume this
2272 thread with a signal? Maybe we should maintain a queue of
2273 pending signals to deliver. */
2274 if (sig
!= GDB_SIGNAL_0
)
2276 warning (_("Couldn't deliver signal %s to %s."),
2277 gdb_signal_to_name (sig
),
2278 target_pid_to_str (tp
->ptid
).c_str ());
2281 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2283 if (target_can_async_p ())
2286 /* Tell the event loop we have an event to process. */
2287 mark_async_event_handler (infrun_async_inferior_event_token
);
2292 tp
->stepped_breakpoint
= 0;
2294 /* Depends on stepped_breakpoint. */
2295 step
= currently_stepping (tp
);
2297 if (current_inferior ()->waiting_for_vfork_done
)
2299 /* Don't try to single-step a vfork parent that is waiting for
2300 the child to get out of the shared memory region (by exec'ing
2301 or exiting). This is particularly important on software
2302 single-step archs, as the child process would trip on the
2303 software single step breakpoint inserted for the parent
2304 process. Since the parent will not actually execute any
2305 instruction until the child is out of the shared region (such
2306 are vfork's semantics), it is safe to simply continue it.
2307 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2308 the parent, and tell it to `keep_going', which automatically
2309 re-sets it stepping. */
2310 infrun_debug_printf ("resume : clear step");
2314 CORE_ADDR pc
= regcache_read_pc (regcache
);
2316 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2317 "current thread [%s] at %s",
2318 step
, gdb_signal_to_symbol_string (sig
),
2319 tp
->control
.trap_expected
,
2320 target_pid_to_str (inferior_ptid
).c_str (),
2321 paddress (gdbarch
, pc
));
2323 /* Normally, by the time we reach `resume', the breakpoints are either
2324 removed or inserted, as appropriate. The exception is if we're sitting
2325 at a permanent breakpoint; we need to step over it, but permanent
2326 breakpoints can't be removed. So we have to test for it here. */
2327 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2329 if (sig
!= GDB_SIGNAL_0
)
2331 /* We have a signal to pass to the inferior. The resume
2332 may, or may not take us to the signal handler. If this
2333 is a step, we'll need to stop in the signal handler, if
2334 there's one, (if the target supports stepping into
2335 handlers), or in the next mainline instruction, if
2336 there's no handler. If this is a continue, we need to be
2337 sure to run the handler with all breakpoints inserted.
2338 In all cases, set a breakpoint at the current address
2339 (where the handler returns to), and once that breakpoint
2340 is hit, resume skipping the permanent breakpoint. If
2341 that breakpoint isn't hit, then we've stepped into the
2342 signal handler (or hit some other event). We'll delete
2343 the step-resume breakpoint then. */
2345 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2346 "deliver signal first");
2348 clear_step_over_info ();
2349 tp
->control
.trap_expected
= 0;
2351 if (tp
->control
.step_resume_breakpoint
== NULL
)
2353 /* Set a "high-priority" step-resume, as we don't want
2354 user breakpoints at PC to trigger (again) when this
2356 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2357 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2359 tp
->step_after_step_resume_breakpoint
= step
;
2362 insert_breakpoints ();
2366 /* There's no signal to pass, we can go ahead and skip the
2367 permanent breakpoint manually. */
2368 infrun_debug_printf ("skipping permanent breakpoint");
2369 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2370 /* Update pc to reflect the new address from which we will
2371 execute instructions. */
2372 pc
= regcache_read_pc (regcache
);
2376 /* We've already advanced the PC, so the stepping part
2377 is done. Now we need to arrange for a trap to be
2378 reported to handle_inferior_event. Set a breakpoint
2379 at the current PC, and run to it. Don't update
2380 prev_pc, because if we end in
2381 switch_back_to_stepped_thread, we want the "expected
2382 thread advanced also" branch to be taken. IOW, we
2383 don't want this thread to step further from PC
2385 gdb_assert (!step_over_info_valid_p ());
2386 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2387 insert_breakpoints ();
2389 resume_ptid
= internal_resume_ptid (user_step
);
2390 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2397 /* If we have a breakpoint to step over, make sure to do a single
2398 step only. Same if we have software watchpoints. */
2399 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2400 tp
->control
.may_range_step
= 0;
2402 /* If displaced stepping is enabled, step over breakpoints by executing a
2403 copy of the instruction at a different address.
2405 We can't use displaced stepping when we have a signal to deliver;
2406 the comments for displaced_step_prepare explain why. The
2407 comments in the handle_inferior event for dealing with 'random
2408 signals' explain what we do instead.
2410 We can't use displaced stepping when we are waiting for vfork_done
2411 event, displaced stepping breaks the vfork child similarly as single
2412 step software breakpoint. */
2413 if (tp
->control
.trap_expected
2414 && use_displaced_stepping (tp
)
2415 && !step_over_info_valid_p ()
2416 && sig
== GDB_SIGNAL_0
2417 && !current_inferior ()->waiting_for_vfork_done
)
2419 displaced_step_prepare_status prepare_status
2420 = displaced_step_prepare (tp
);
2422 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2424 infrun_debug_printf ("Got placed in step-over queue");
2426 tp
->control
.trap_expected
= 0;
2429 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
2431 /* Fallback to stepping over the breakpoint in-line. */
2433 if (target_is_non_stop_p ())
2434 stop_all_threads ();
2436 set_step_over_info (regcache
->aspace (),
2437 regcache_read_pc (regcache
), 0, tp
->global_num
);
2439 step
= maybe_software_singlestep (gdbarch
, pc
);
2441 insert_breakpoints ();
2443 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2445 /* Update pc to reflect the new address from which we will
2446 execute instructions due to displaced stepping. */
2447 pc
= regcache_read_pc (get_thread_regcache (tp
));
2449 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2452 gdb_assert_not_reached (_("Invalid displaced_step_prepare_status "
2456 /* Do we need to do it the hard way, w/temp breakpoints? */
2458 step
= maybe_software_singlestep (gdbarch
, pc
);
2460 /* Currently, our software single-step implementation leads to different
2461 results than hardware single-stepping in one situation: when stepping
2462 into delivering a signal which has an associated signal handler,
2463 hardware single-step will stop at the first instruction of the handler,
2464 while software single-step will simply skip execution of the handler.
2466 For now, this difference in behavior is accepted since there is no
2467 easy way to actually implement single-stepping into a signal handler
2468 without kernel support.
2470 However, there is one scenario where this difference leads to follow-on
2471 problems: if we're stepping off a breakpoint by removing all breakpoints
2472 and then single-stepping. In this case, the software single-step
2473 behavior means that even if there is a *breakpoint* in the signal
2474 handler, GDB still would not stop.
2476 Fortunately, we can at least fix this particular issue. We detect
2477 here the case where we are about to deliver a signal while software
2478 single-stepping with breakpoints removed. In this situation, we
2479 revert the decisions to remove all breakpoints and insert single-
2480 step breakpoints, and instead we install a step-resume breakpoint
2481 at the current address, deliver the signal without stepping, and
2482 once we arrive back at the step-resume breakpoint, actually step
2483 over the breakpoint we originally wanted to step over. */
2484 if (thread_has_single_step_breakpoints_set (tp
)
2485 && sig
!= GDB_SIGNAL_0
2486 && step_over_info_valid_p ())
2488 /* If we have nested signals or a pending signal is delivered
2489 immediately after a handler returns, might already have
2490 a step-resume breakpoint set on the earlier handler. We cannot
2491 set another step-resume breakpoint; just continue on until the
2492 original breakpoint is hit. */
2493 if (tp
->control
.step_resume_breakpoint
== NULL
)
2495 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2496 tp
->step_after_step_resume_breakpoint
= 1;
2499 delete_single_step_breakpoints (tp
);
2501 clear_step_over_info ();
2502 tp
->control
.trap_expected
= 0;
2504 insert_breakpoints ();
2507 /* If STEP is set, it's a request to use hardware stepping
2508 facilities. But in that case, we should never
2509 use singlestep breakpoint. */
2510 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2512 /* Decide the set of threads to ask the target to resume. */
2513 if (tp
->control
.trap_expected
)
2515 /* We're allowing a thread to run past a breakpoint it has
2516 hit, either by single-stepping the thread with the breakpoint
2517 removed, or by displaced stepping, with the breakpoint inserted.
2518 In the former case, we need to single-step only this thread,
2519 and keep others stopped, as they can miss this breakpoint if
2520 allowed to run. That's not really a problem for displaced
2521 stepping, but, we still keep other threads stopped, in case
2522 another thread is also stopped for a breakpoint waiting for
2523 its turn in the displaced stepping queue. */
2524 resume_ptid
= inferior_ptid
;
2527 resume_ptid
= internal_resume_ptid (user_step
);
2529 if (execution_direction
!= EXEC_REVERSE
2530 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2532 /* There are two cases where we currently need to step a
2533 breakpoint instruction when we have a signal to deliver:
2535 - See handle_signal_stop where we handle random signals that
2536 could take out us out of the stepping range. Normally, in
2537 that case we end up continuing (instead of stepping) over the
2538 signal handler with a breakpoint at PC, but there are cases
2539 where we should _always_ single-step, even if we have a
2540 step-resume breakpoint, like when a software watchpoint is
2541 set. Assuming single-stepping and delivering a signal at the
2542 same time would takes us to the signal handler, then we could
2543 have removed the breakpoint at PC to step over it. However,
2544 some hardware step targets (like e.g., Mac OS) can't step
2545 into signal handlers, and for those, we need to leave the
2546 breakpoint at PC inserted, as otherwise if the handler
2547 recurses and executes PC again, it'll miss the breakpoint.
2548 So we leave the breakpoint inserted anyway, but we need to
2549 record that we tried to step a breakpoint instruction, so
2550 that adjust_pc_after_break doesn't end up confused.
2552 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2553 in one thread after another thread that was stepping had been
2554 momentarily paused for a step-over. When we re-resume the
2555 stepping thread, it may be resumed from that address with a
2556 breakpoint that hasn't trapped yet. Seen with
2557 gdb.threads/non-stop-fair-events.exp, on targets that don't
2558 do displaced stepping. */
2560 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2561 target_pid_to_str (tp
->ptid
).c_str ());
2563 tp
->stepped_breakpoint
= 1;
2565 /* Most targets can step a breakpoint instruction, thus
2566 executing it normally. But if this one cannot, just
2567 continue and we will hit it anyway. */
2568 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2573 && tp
->control
.trap_expected
2574 && use_displaced_stepping (tp
)
2575 && !step_over_info_valid_p ())
2577 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2578 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2579 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2582 read_memory (actual_pc
, buf
, sizeof (buf
));
2583 displaced_debug_printf ("run %s: %s",
2584 paddress (resume_gdbarch
, actual_pc
),
2585 displaced_step_dump_bytes
2586 (buf
, sizeof (buf
)).c_str ());
2589 if (tp
->control
.may_range_step
)
2591 /* If we're resuming a thread with the PC out of the step
2592 range, then we're doing some nested/finer run control
2593 operation, like stepping the thread out of the dynamic
2594 linker or the displaced stepping scratch pad. We
2595 shouldn't have allowed a range step then. */
2596 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2599 do_target_resume (resume_ptid
, step
, sig
);
2603 /* Resume the inferior. SIG is the signal to give the inferior
2604 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2605 rolls back state on error. */
2608 resume (gdb_signal sig
)
2614 catch (const gdb_exception
&ex
)
2616 /* If resuming is being aborted for any reason, delete any
2617 single-step breakpoint resume_1 may have created, to avoid
2618 confusing the following resumption, and to avoid leaving
2619 single-step breakpoints perturbing other threads, in case
2620 we're running in non-stop mode. */
2621 if (inferior_ptid
!= null_ptid
)
2622 delete_single_step_breakpoints (inferior_thread ());
2632 /* Counter that tracks number of user visible stops. This can be used
2633 to tell whether a command has proceeded the inferior past the
2634 current location. This allows e.g., inferior function calls in
2635 breakpoint commands to not interrupt the command list. When the
2636 call finishes successfully, the inferior is standing at the same
2637 breakpoint as if nothing happened (and so we don't call
2639 static ULONGEST current_stop_id
;
2646 return current_stop_id
;
2649 /* Called when we report a user visible stop. */
2657 /* Clear out all variables saying what to do when inferior is continued.
2658 First do this, then set the ones you want, then call `proceed'. */
2661 clear_proceed_status_thread (struct thread_info
*tp
)
2663 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2665 /* If we're starting a new sequence, then the previous finished
2666 single-step is no longer relevant. */
2667 if (tp
->suspend
.waitstatus_pending_p
)
2669 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2671 infrun_debug_printf ("pending event of %s was a finished step. "
2673 target_pid_to_str (tp
->ptid
).c_str ());
2675 tp
->suspend
.waitstatus_pending_p
= 0;
2676 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2681 ("thread %s has pending wait status %s (currently_stepping=%d).",
2682 target_pid_to_str (tp
->ptid
).c_str (),
2683 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2684 currently_stepping (tp
));
2688 /* If this signal should not be seen by program, give it zero.
2689 Used for debugging signals. */
2690 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2691 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2693 delete tp
->thread_fsm
;
2694 tp
->thread_fsm
= NULL
;
2696 tp
->control
.trap_expected
= 0;
2697 tp
->control
.step_range_start
= 0;
2698 tp
->control
.step_range_end
= 0;
2699 tp
->control
.may_range_step
= 0;
2700 tp
->control
.step_frame_id
= null_frame_id
;
2701 tp
->control
.step_stack_frame_id
= null_frame_id
;
2702 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2703 tp
->control
.step_start_function
= NULL
;
2704 tp
->stop_requested
= 0;
2706 tp
->control
.stop_step
= 0;
2708 tp
->control
.proceed_to_finish
= 0;
2710 tp
->control
.stepping_command
= 0;
2712 /* Discard any remaining commands or status from previous stop. */
2713 bpstat_clear (&tp
->control
.stop_bpstat
);
2717 clear_proceed_status (int step
)
2719 /* With scheduler-locking replay, stop replaying other threads if we're
2720 not replaying the user-visible resume ptid.
2722 This is a convenience feature to not require the user to explicitly
2723 stop replaying the other threads. We're assuming that the user's
2724 intent is to resume tracing the recorded process. */
2725 if (!non_stop
&& scheduler_mode
== schedlock_replay
2726 && target_record_is_replaying (minus_one_ptid
)
2727 && !target_record_will_replay (user_visible_resume_ptid (step
),
2728 execution_direction
))
2729 target_record_stop_replaying ();
2731 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2733 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2734 process_stratum_target
*resume_target
2735 = user_visible_resume_target (resume_ptid
);
2737 /* In all-stop mode, delete the per-thread status of all threads
2738 we're about to resume, implicitly and explicitly. */
2739 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2740 clear_proceed_status_thread (tp
);
2743 if (inferior_ptid
!= null_ptid
)
2745 struct inferior
*inferior
;
2749 /* If in non-stop mode, only delete the per-thread status of
2750 the current thread. */
2751 clear_proceed_status_thread (inferior_thread ());
2754 inferior
= current_inferior ();
2755 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2758 gdb::observers::about_to_proceed
.notify ();
2761 /* Returns true if TP is still stopped at a breakpoint that needs
2762 stepping-over in order to make progress. If the breakpoint is gone
2763 meanwhile, we can skip the whole step-over dance. */
2766 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2768 if (tp
->stepping_over_breakpoint
)
2770 struct regcache
*regcache
= get_thread_regcache (tp
);
2772 if (breakpoint_here_p (regcache
->aspace (),
2773 regcache_read_pc (regcache
))
2774 == ordinary_breakpoint_here
)
2777 tp
->stepping_over_breakpoint
= 0;
2783 /* Check whether thread TP still needs to start a step-over in order
2784 to make progress when resumed. Returns an bitwise or of enum
2785 step_over_what bits, indicating what needs to be stepped over. */
2787 static step_over_what
2788 thread_still_needs_step_over (struct thread_info
*tp
)
2790 step_over_what what
= 0;
2792 if (thread_still_needs_step_over_bp (tp
))
2793 what
|= STEP_OVER_BREAKPOINT
;
2795 if (tp
->stepping_over_watchpoint
2796 && !target_have_steppable_watchpoint ())
2797 what
|= STEP_OVER_WATCHPOINT
;
2802 /* Returns true if scheduler locking applies. STEP indicates whether
2803 we're about to do a step/next-like command to a thread. */
2806 schedlock_applies (struct thread_info
*tp
)
2808 return (scheduler_mode
== schedlock_on
2809 || (scheduler_mode
== schedlock_step
2810 && tp
->control
.stepping_command
)
2811 || (scheduler_mode
== schedlock_replay
2812 && target_record_will_replay (minus_one_ptid
,
2813 execution_direction
)));
2816 /* Calls target_commit_resume on all targets. */
2819 commit_resume_all_targets ()
2821 scoped_restore_current_thread restore_thread
;
2823 /* Map between process_target and a representative inferior. This
2824 is to avoid committing a resume in the same target more than
2825 once. Resumptions must be idempotent, so this is an
2827 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2829 for (inferior
*inf
: all_non_exited_inferiors ())
2830 if (inf
->has_execution ())
2831 conn_inf
[inf
->process_target ()] = inf
;
2833 for (const auto &ci
: conn_inf
)
2835 inferior
*inf
= ci
.second
;
2836 switch_to_inferior_no_thread (inf
);
2837 target_commit_resume ();
2841 /* Check that all the targets we're about to resume are in non-stop
2842 mode. Ideally, we'd only care whether all targets support
2843 target-async, but we're not there yet. E.g., stop_all_threads
2844 doesn't know how to handle all-stop targets. Also, the remote
2845 protocol in all-stop mode is synchronous, irrespective of
2846 target-async, which means that things like a breakpoint re-set
2847 triggered by one target would try to read memory from all targets
2851 check_multi_target_resumption (process_stratum_target
*resume_target
)
2853 if (!non_stop
&& resume_target
== nullptr)
2855 scoped_restore_current_thread restore_thread
;
2857 /* This is used to track whether we're resuming more than one
2859 process_stratum_target
*first_connection
= nullptr;
2861 /* The first inferior we see with a target that does not work in
2862 always-non-stop mode. */
2863 inferior
*first_not_non_stop
= nullptr;
2865 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2867 switch_to_inferior_no_thread (inf
);
2869 if (!target_has_execution ())
2872 process_stratum_target
*proc_target
2873 = current_inferior ()->process_target();
2875 if (!target_is_non_stop_p ())
2876 first_not_non_stop
= inf
;
2878 if (first_connection
== nullptr)
2879 first_connection
= proc_target
;
2880 else if (first_connection
!= proc_target
2881 && first_not_non_stop
!= nullptr)
2883 switch_to_inferior_no_thread (first_not_non_stop
);
2885 proc_target
= current_inferior ()->process_target();
2887 error (_("Connection %d (%s) does not support "
2888 "multi-target resumption."),
2889 proc_target
->connection_number
,
2890 make_target_connection_string (proc_target
).c_str ());
2896 /* Basic routine for continuing the program in various fashions.
2898 ADDR is the address to resume at, or -1 for resume where stopped.
2899 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2900 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2902 You should call clear_proceed_status before calling proceed. */
2905 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2907 struct regcache
*regcache
;
2908 struct gdbarch
*gdbarch
;
2910 struct execution_control_state ecss
;
2911 struct execution_control_state
*ecs
= &ecss
;
2914 /* If we're stopped at a fork/vfork, follow the branch set by the
2915 "set follow-fork-mode" command; otherwise, we'll just proceed
2916 resuming the current thread. */
2917 if (!follow_fork ())
2919 /* The target for some reason decided not to resume. */
2921 if (target_can_async_p ())
2922 inferior_event_handler (INF_EXEC_COMPLETE
);
2926 /* We'll update this if & when we switch to a new thread. */
2927 previous_inferior_ptid
= inferior_ptid
;
2929 regcache
= get_current_regcache ();
2930 gdbarch
= regcache
->arch ();
2931 const address_space
*aspace
= regcache
->aspace ();
2933 pc
= regcache_read_pc_protected (regcache
);
2935 thread_info
*cur_thr
= inferior_thread ();
2937 /* Fill in with reasonable starting values. */
2938 init_thread_stepping_state (cur_thr
);
2940 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2943 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2944 process_stratum_target
*resume_target
2945 = user_visible_resume_target (resume_ptid
);
2947 check_multi_target_resumption (resume_target
);
2949 if (addr
== (CORE_ADDR
) -1)
2951 if (pc
== cur_thr
->suspend
.stop_pc
2952 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2953 && execution_direction
!= EXEC_REVERSE
)
2954 /* There is a breakpoint at the address we will resume at,
2955 step one instruction before inserting breakpoints so that
2956 we do not stop right away (and report a second hit at this
2959 Note, we don't do this in reverse, because we won't
2960 actually be executing the breakpoint insn anyway.
2961 We'll be (un-)executing the previous instruction. */
2962 cur_thr
->stepping_over_breakpoint
= 1;
2963 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2964 && gdbarch_single_step_through_delay (gdbarch
,
2965 get_current_frame ()))
2966 /* We stepped onto an instruction that needs to be stepped
2967 again before re-inserting the breakpoint, do so. */
2968 cur_thr
->stepping_over_breakpoint
= 1;
2972 regcache_write_pc (regcache
, addr
);
2975 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2976 cur_thr
->suspend
.stop_signal
= siggnal
;
2978 /* If an exception is thrown from this point on, make sure to
2979 propagate GDB's knowledge of the executing state to the
2980 frontend/user running state. */
2981 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2983 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2984 threads (e.g., we might need to set threads stepping over
2985 breakpoints first), from the user/frontend's point of view, all
2986 threads in RESUME_PTID are now running. Unless we're calling an
2987 inferior function, as in that case we pretend the inferior
2988 doesn't run at all. */
2989 if (!cur_thr
->control
.in_infcall
)
2990 set_running (resume_target
, resume_ptid
, true);
2992 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
2993 gdb_signal_to_symbol_string (siggnal
));
2995 annotate_starting ();
2997 /* Make sure that output from GDB appears before output from the
2999 gdb_flush (gdb_stdout
);
3001 /* Since we've marked the inferior running, give it the terminal. A
3002 QUIT/Ctrl-C from here on is forwarded to the target (which can
3003 still detect attempts to unblock a stuck connection with repeated
3004 Ctrl-C from within target_pass_ctrlc). */
3005 target_terminal::inferior ();
3007 /* In a multi-threaded task we may select another thread and
3008 then continue or step.
3010 But if a thread that we're resuming had stopped at a breakpoint,
3011 it will immediately cause another breakpoint stop without any
3012 execution (i.e. it will report a breakpoint hit incorrectly). So
3013 we must step over it first.
3015 Look for threads other than the current (TP) that reported a
3016 breakpoint hit and haven't been resumed yet since. */
3018 /* If scheduler locking applies, we can avoid iterating over all
3020 if (!non_stop
&& !schedlock_applies (cur_thr
))
3022 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3025 switch_to_thread_no_regs (tp
);
3027 /* Ignore the current thread here. It's handled
3032 if (!thread_still_needs_step_over (tp
))
3035 gdb_assert (!thread_is_in_step_over_chain (tp
));
3037 infrun_debug_printf ("need to step-over [%s] first",
3038 target_pid_to_str (tp
->ptid
).c_str ());
3040 global_thread_step_over_chain_enqueue (tp
);
3043 switch_to_thread (cur_thr
);
3046 /* Enqueue the current thread last, so that we move all other
3047 threads over their breakpoints first. */
3048 if (cur_thr
->stepping_over_breakpoint
)
3049 global_thread_step_over_chain_enqueue (cur_thr
);
3051 /* If the thread isn't started, we'll still need to set its prev_pc,
3052 so that switch_back_to_stepped_thread knows the thread hasn't
3053 advanced. Must do this before resuming any thread, as in
3054 all-stop/remote, once we resume we can't send any other packet
3055 until the target stops again. */
3056 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3059 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3061 started
= start_step_over ();
3063 if (step_over_info_valid_p ())
3065 /* Either this thread started a new in-line step over, or some
3066 other thread was already doing one. In either case, don't
3067 resume anything else until the step-over is finished. */
3069 else if (started
&& !target_is_non_stop_p ())
3071 /* A new displaced stepping sequence was started. In all-stop,
3072 we can't talk to the target anymore until it next stops. */
3074 else if (!non_stop
&& target_is_non_stop_p ())
3076 /* In all-stop, but the target is always in non-stop mode.
3077 Start all other threads that are implicitly resumed too. */
3078 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3081 switch_to_thread_no_regs (tp
);
3083 if (!tp
->inf
->has_execution ())
3085 infrun_debug_printf ("[%s] target has no execution",
3086 target_pid_to_str (tp
->ptid
).c_str ());
3092 infrun_debug_printf ("[%s] resumed",
3093 target_pid_to_str (tp
->ptid
).c_str ());
3094 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3098 if (thread_is_in_step_over_chain (tp
))
3100 infrun_debug_printf ("[%s] needs step-over",
3101 target_pid_to_str (tp
->ptid
).c_str ());
3105 infrun_debug_printf ("resuming %s",
3106 target_pid_to_str (tp
->ptid
).c_str ());
3108 reset_ecs (ecs
, tp
);
3109 switch_to_thread (tp
);
3110 keep_going_pass_signal (ecs
);
3111 if (!ecs
->wait_some_more
)
3112 error (_("Command aborted."));
3115 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3117 /* The thread wasn't started, and isn't queued, run it now. */
3118 reset_ecs (ecs
, cur_thr
);
3119 switch_to_thread (cur_thr
);
3120 keep_going_pass_signal (ecs
);
3121 if (!ecs
->wait_some_more
)
3122 error (_("Command aborted."));
3126 commit_resume_all_targets ();
3128 finish_state
.release ();
3130 /* If we've switched threads above, switch back to the previously
3131 current thread. We don't want the user to see a different
3133 switch_to_thread (cur_thr
);
3135 /* Tell the event loop to wait for it to stop. If the target
3136 supports asynchronous execution, it'll do this from within
3138 if (!target_can_async_p ())
3139 mark_async_event_handler (infrun_async_inferior_event_token
);
3143 /* Start remote-debugging of a machine over a serial link. */
3146 start_remote (int from_tty
)
3148 inferior
*inf
= current_inferior ();
3149 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3151 /* Always go on waiting for the target, regardless of the mode. */
3152 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3153 indicate to wait_for_inferior that a target should timeout if
3154 nothing is returned (instead of just blocking). Because of this,
3155 targets expecting an immediate response need to, internally, set
3156 things up so that the target_wait() is forced to eventually
3158 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3159 differentiate to its caller what the state of the target is after
3160 the initial open has been performed. Here we're assuming that
3161 the target has stopped. It should be possible to eventually have
3162 target_open() return to the caller an indication that the target
3163 is currently running and GDB state should be set to the same as
3164 for an async run. */
3165 wait_for_inferior (inf
);
3167 /* Now that the inferior has stopped, do any bookkeeping like
3168 loading shared libraries. We want to do this before normal_stop,
3169 so that the displayed frame is up to date. */
3170 post_create_inferior (from_tty
);
3175 /* Initialize static vars when a new inferior begins. */
3178 init_wait_for_inferior (void)
3180 /* These are meaningless until the first time through wait_for_inferior. */
3182 breakpoint_init_inferior (inf_starting
);
3184 clear_proceed_status (0);
3186 nullify_last_target_wait_ptid ();
3188 previous_inferior_ptid
= inferior_ptid
;
3193 static void handle_inferior_event (struct execution_control_state
*ecs
);
3195 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3196 struct execution_control_state
*ecs
);
3197 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3198 struct execution_control_state
*ecs
);
3199 static void handle_signal_stop (struct execution_control_state
*ecs
);
3200 static void check_exception_resume (struct execution_control_state
*,
3201 struct frame_info
*);
3203 static void end_stepping_range (struct execution_control_state
*ecs
);
3204 static void stop_waiting (struct execution_control_state
*ecs
);
3205 static void keep_going (struct execution_control_state
*ecs
);
3206 static void process_event_stop_test (struct execution_control_state
*ecs
);
3207 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3209 /* This function is attached as a "thread_stop_requested" observer.
3210 Cleanup local state that assumed the PTID was to be resumed, and
3211 report the stop to the frontend. */
3214 infrun_thread_stop_requested (ptid_t ptid
)
3216 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3218 /* PTID was requested to stop. If the thread was already stopped,
3219 but the user/frontend doesn't know about that yet (e.g., the
3220 thread had been temporarily paused for some step-over), set up
3221 for reporting the stop now. */
3222 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3224 if (tp
->state
!= THREAD_RUNNING
)
3229 /* Remove matching threads from the step-over queue, so
3230 start_step_over doesn't try to resume them
3232 if (thread_is_in_step_over_chain (tp
))
3233 global_thread_step_over_chain_remove (tp
);
3235 /* If the thread is stopped, but the user/frontend doesn't
3236 know about that yet, queue a pending event, as if the
3237 thread had just stopped now. Unless the thread already had
3239 if (!tp
->suspend
.waitstatus_pending_p
)
3241 tp
->suspend
.waitstatus_pending_p
= 1;
3242 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3243 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3246 /* Clear the inline-frame state, since we're re-processing the
3248 clear_inline_frame_state (tp
);
3250 /* If this thread was paused because some other thread was
3251 doing an inline-step over, let that finish first. Once
3252 that happens, we'll restart all threads and consume pending
3253 stop events then. */
3254 if (step_over_info_valid_p ())
3257 /* Otherwise we can process the (new) pending event now. Set
3258 it so this pending event is considered by
3265 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3267 if (target_last_proc_target
== tp
->inf
->process_target ()
3268 && target_last_wait_ptid
== tp
->ptid
)
3269 nullify_last_target_wait_ptid ();
3272 /* Delete the step resume, single-step and longjmp/exception resume
3273 breakpoints of TP. */
3276 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3278 delete_step_resume_breakpoint (tp
);
3279 delete_exception_resume_breakpoint (tp
);
3280 delete_single_step_breakpoints (tp
);
3283 /* If the target still has execution, call FUNC for each thread that
3284 just stopped. In all-stop, that's all the non-exited threads; in
3285 non-stop, that's the current thread, only. */
3287 typedef void (*for_each_just_stopped_thread_callback_func
)
3288 (struct thread_info
*tp
);
3291 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3293 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3296 if (target_is_non_stop_p ())
3298 /* If in non-stop mode, only the current thread stopped. */
3299 func (inferior_thread ());
3303 /* In all-stop mode, all threads have stopped. */
3304 for (thread_info
*tp
: all_non_exited_threads ())
3309 /* Delete the step resume and longjmp/exception resume breakpoints of
3310 the threads that just stopped. */
3313 delete_just_stopped_threads_infrun_breakpoints (void)
3315 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3318 /* Delete the single-step breakpoints of the threads that just
3322 delete_just_stopped_threads_single_step_breakpoints (void)
3324 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3330 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3331 const struct target_waitstatus
*ws
)
3333 std::string status_string
= target_waitstatus_to_string (ws
);
3336 /* The text is split over several lines because it was getting too long.
3337 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3338 output as a unit; we want only one timestamp printed if debug_timestamp
3341 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3344 waiton_ptid
.tid ());
3345 if (waiton_ptid
.pid () != -1)
3346 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3347 stb
.printf (", status) =\n");
3348 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3352 target_pid_to_str (result_ptid
).c_str ());
3353 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3355 /* This uses %s in part to handle %'s in the text, but also to avoid
3356 a gcc error: the format attribute requires a string literal. */
3357 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3360 /* Select a thread at random, out of those which are resumed and have
3363 static struct thread_info
*
3364 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3368 auto has_event
= [&] (thread_info
*tp
)
3370 return (tp
->ptid
.matches (waiton_ptid
)
3372 && tp
->suspend
.waitstatus_pending_p
);
3375 /* First see how many events we have. Count only resumed threads
3376 that have an event pending. */
3377 for (thread_info
*tp
: inf
->non_exited_threads ())
3381 if (num_events
== 0)
3384 /* Now randomly pick a thread out of those that have had events. */
3385 int random_selector
= (int) ((num_events
* (double) rand ())
3386 / (RAND_MAX
+ 1.0));
3389 infrun_debug_printf ("Found %d events, selecting #%d",
3390 num_events
, random_selector
);
3392 /* Select the Nth thread that has had an event. */
3393 for (thread_info
*tp
: inf
->non_exited_threads ())
3395 if (random_selector
-- == 0)
3398 gdb_assert_not_reached ("event thread not found");
3401 /* Wrapper for target_wait that first checks whether threads have
3402 pending statuses to report before actually asking the target for
3403 more events. INF is the inferior we're using to call target_wait
3407 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3408 target_waitstatus
*status
, target_wait_flags options
)
3411 struct thread_info
*tp
;
3413 /* We know that we are looking for an event in the target of inferior
3414 INF, but we don't know which thread the event might come from. As
3415 such we want to make sure that INFERIOR_PTID is reset so that none of
3416 the wait code relies on it - doing so is always a mistake. */
3417 switch_to_inferior_no_thread (inf
);
3419 /* First check if there is a resumed thread with a wait status
3421 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3423 tp
= random_pending_event_thread (inf
, ptid
);
3427 infrun_debug_printf ("Waiting for specific thread %s.",
3428 target_pid_to_str (ptid
).c_str ());
3430 /* We have a specific thread to check. */
3431 tp
= find_thread_ptid (inf
, ptid
);
3432 gdb_assert (tp
!= NULL
);
3433 if (!tp
->suspend
.waitstatus_pending_p
)
3438 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3439 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3441 struct regcache
*regcache
= get_thread_regcache (tp
);
3442 struct gdbarch
*gdbarch
= regcache
->arch ();
3446 pc
= regcache_read_pc (regcache
);
3448 if (pc
!= tp
->suspend
.stop_pc
)
3450 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3451 target_pid_to_str (tp
->ptid
).c_str (),
3452 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3453 paddress (gdbarch
, pc
));
3456 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3458 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3459 target_pid_to_str (tp
->ptid
).c_str (),
3460 paddress (gdbarch
, pc
));
3467 infrun_debug_printf ("pending event of %s cancelled.",
3468 target_pid_to_str (tp
->ptid
).c_str ());
3470 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3471 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3477 infrun_debug_printf ("Using pending wait status %s for %s.",
3478 target_waitstatus_to_string
3479 (&tp
->suspend
.waitstatus
).c_str (),
3480 target_pid_to_str (tp
->ptid
).c_str ());
3482 /* Now that we've selected our final event LWP, un-adjust its PC
3483 if it was a software breakpoint (and the target doesn't
3484 always adjust the PC itself). */
3485 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3486 && !target_supports_stopped_by_sw_breakpoint ())
3488 struct regcache
*regcache
;
3489 struct gdbarch
*gdbarch
;
3492 regcache
= get_thread_regcache (tp
);
3493 gdbarch
= regcache
->arch ();
3495 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3500 pc
= regcache_read_pc (regcache
);
3501 regcache_write_pc (regcache
, pc
+ decr_pc
);
3505 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3506 *status
= tp
->suspend
.waitstatus
;
3507 tp
->suspend
.waitstatus_pending_p
= 0;
3509 /* Wake up the event loop again, until all pending events are
3511 if (target_is_async_p ())
3512 mark_async_event_handler (infrun_async_inferior_event_token
);
3516 /* But if we don't find one, we'll have to wait. */
3518 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3520 if (!target_can_async_p ())
3521 options
&= ~TARGET_WNOHANG
;
3523 if (deprecated_target_wait_hook
)
3524 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3526 event_ptid
= target_wait (ptid
, status
, options
);
3531 /* Wrapper for target_wait that first checks whether threads have
3532 pending statuses to report before actually asking the target for
3533 more events. Polls for events from all inferiors/targets. */
3536 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3537 target_wait_flags options
)
3539 int num_inferiors
= 0;
3540 int random_selector
;
3542 /* For fairness, we pick the first inferior/target to poll at random
3543 out of all inferiors that may report events, and then continue
3544 polling the rest of the inferior list starting from that one in a
3545 circular fashion until the whole list is polled once. */
3547 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3549 return (inf
->process_target () != NULL
3550 && ptid_t (inf
->pid
).matches (wait_ptid
));
3553 /* First see how many matching inferiors we have. */
3554 for (inferior
*inf
: all_inferiors ())
3555 if (inferior_matches (inf
))
3558 if (num_inferiors
== 0)
3560 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3564 /* Now randomly pick an inferior out of those that matched. */
3565 random_selector
= (int)
3566 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3568 if (num_inferiors
> 1)
3569 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3570 num_inferiors
, random_selector
);
3572 /* Select the Nth inferior that matched. */
3574 inferior
*selected
= nullptr;
3576 for (inferior
*inf
: all_inferiors ())
3577 if (inferior_matches (inf
))
3578 if (random_selector
-- == 0)
3584 /* Now poll for events out of each of the matching inferior's
3585 targets, starting from the selected one. */
3587 auto do_wait
= [&] (inferior
*inf
)
3589 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3590 ecs
->target
= inf
->process_target ();
3591 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3594 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3595 here spuriously after the target is all stopped and we've already
3596 reported the stop to the user, polling for events. */
3597 scoped_restore_current_thread restore_thread
;
3599 int inf_num
= selected
->num
;
3600 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3601 if (inferior_matches (inf
))
3605 for (inferior
*inf
= inferior_list
;
3606 inf
!= NULL
&& inf
->num
< inf_num
;
3608 if (inferior_matches (inf
))
3612 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3616 /* Prepare and stabilize the inferior for detaching it. E.g.,
3617 detaching while a thread is displaced stepping is a recipe for
3618 crashing it, as nothing would readjust the PC out of the scratch
3622 prepare_for_detach (void)
3624 struct inferior
*inf
= current_inferior ();
3625 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3627 displaced_step_inferior_state
*displaced
= &inf
->displaced_step_state
;
3629 /* Is any thread of this process displaced stepping? If not,
3630 there's nothing else to do. */
3631 if (displaced
->step_thread
== nullptr)
3634 infrun_debug_printf ("displaced-stepping in-process while detaching");
3636 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3638 while (displaced
->step_thread
!= nullptr)
3640 struct execution_control_state ecss
;
3641 struct execution_control_state
*ecs
;
3644 memset (ecs
, 0, sizeof (*ecs
));
3646 overlay_cache_invalid
= 1;
3647 /* Flush target cache before starting to handle each event.
3648 Target was running and cache could be stale. This is just a
3649 heuristic. Running threads may modify target memory, but we
3650 don't get any event. */
3651 target_dcache_invalidate ();
3653 do_target_wait (pid_ptid
, ecs
, 0);
3656 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3658 /* If an error happens while handling the event, propagate GDB's
3659 knowledge of the executing state to the frontend/user running
3661 scoped_finish_thread_state
finish_state (inf
->process_target (),
3664 /* Now figure out what to do with the result of the result. */
3665 handle_inferior_event (ecs
);
3667 /* No error, don't finish the state yet. */
3668 finish_state
.release ();
3670 /* Breakpoints and watchpoints are not installed on the target
3671 at this point, and signals are passed directly to the
3672 inferior, so this must mean the process is gone. */
3673 if (!ecs
->wait_some_more
)
3675 restore_detaching
.release ();
3676 error (_("Program exited while detaching"));
3680 restore_detaching
.release ();
3683 /* Wait for control to return from inferior to debugger.
3685 If inferior gets a signal, we may decide to start it up again
3686 instead of returning. That is why there is a loop in this function.
3687 When this function actually returns it means the inferior
3688 should be left stopped and GDB should read more commands. */
3691 wait_for_inferior (inferior
*inf
)
3693 infrun_debug_printf ("wait_for_inferior ()");
3695 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3697 /* If an error happens while handling the event, propagate GDB's
3698 knowledge of the executing state to the frontend/user running
3700 scoped_finish_thread_state finish_state
3701 (inf
->process_target (), minus_one_ptid
);
3705 struct execution_control_state ecss
;
3706 struct execution_control_state
*ecs
= &ecss
;
3708 memset (ecs
, 0, sizeof (*ecs
));
3710 overlay_cache_invalid
= 1;
3712 /* Flush target cache before starting to handle each event.
3713 Target was running and cache could be stale. This is just a
3714 heuristic. Running threads may modify target memory, but we
3715 don't get any event. */
3716 target_dcache_invalidate ();
3718 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3719 ecs
->target
= inf
->process_target ();
3722 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3724 /* Now figure out what to do with the result of the result. */
3725 handle_inferior_event (ecs
);
3727 if (!ecs
->wait_some_more
)
3731 /* No error, don't finish the state yet. */
3732 finish_state
.release ();
3735 /* Cleanup that reinstalls the readline callback handler, if the
3736 target is running in the background. If while handling the target
3737 event something triggered a secondary prompt, like e.g., a
3738 pagination prompt, we'll have removed the callback handler (see
3739 gdb_readline_wrapper_line). Need to do this as we go back to the
3740 event loop, ready to process further input. Note this has no
3741 effect if the handler hasn't actually been removed, because calling
3742 rl_callback_handler_install resets the line buffer, thus losing
3746 reinstall_readline_callback_handler_cleanup ()
3748 struct ui
*ui
= current_ui
;
3752 /* We're not going back to the top level event loop yet. Don't
3753 install the readline callback, as it'd prep the terminal,
3754 readline-style (raw, noecho) (e.g., --batch). We'll install
3755 it the next time the prompt is displayed, when we're ready
3760 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3761 gdb_rl_callback_handler_reinstall ();
3764 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3765 that's just the event thread. In all-stop, that's all threads. */
3768 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3770 if (ecs
->event_thread
!= NULL
3771 && ecs
->event_thread
->thread_fsm
!= NULL
)
3772 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3776 for (thread_info
*thr
: all_non_exited_threads ())
3778 if (thr
->thread_fsm
== NULL
)
3780 if (thr
== ecs
->event_thread
)
3783 switch_to_thread (thr
);
3784 thr
->thread_fsm
->clean_up (thr
);
3787 if (ecs
->event_thread
!= NULL
)
3788 switch_to_thread (ecs
->event_thread
);
3792 /* Helper for all_uis_check_sync_execution_done that works on the
3796 check_curr_ui_sync_execution_done (void)
3798 struct ui
*ui
= current_ui
;
3800 if (ui
->prompt_state
== PROMPT_NEEDED
3802 && !gdb_in_secondary_prompt_p (ui
))
3804 target_terminal::ours ();
3805 gdb::observers::sync_execution_done
.notify ();
3806 ui_register_input_event_handler (ui
);
3813 all_uis_check_sync_execution_done (void)
3815 SWITCH_THRU_ALL_UIS ()
3817 check_curr_ui_sync_execution_done ();
3824 all_uis_on_sync_execution_starting (void)
3826 SWITCH_THRU_ALL_UIS ()
3828 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3829 async_disable_stdin ();
3833 /* Asynchronous version of wait_for_inferior. It is called by the
3834 event loop whenever a change of state is detected on the file
3835 descriptor corresponding to the target. It can be called more than
3836 once to complete a single execution command. In such cases we need
3837 to keep the state in a global variable ECSS. If it is the last time
3838 that this function is called for a single execution command, then
3839 report to the user that the inferior has stopped, and do the
3840 necessary cleanups. */
3843 fetch_inferior_event ()
3845 struct execution_control_state ecss
;
3846 struct execution_control_state
*ecs
= &ecss
;
3849 memset (ecs
, 0, sizeof (*ecs
));
3851 /* Events are always processed with the main UI as current UI. This
3852 way, warnings, debug output, etc. are always consistently sent to
3853 the main console. */
3854 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3856 /* Temporarily disable pagination. Otherwise, the user would be
3857 given an option to press 'q' to quit, which would cause an early
3858 exit and could leave GDB in a half-baked state. */
3859 scoped_restore save_pagination
3860 = make_scoped_restore (&pagination_enabled
, false);
3862 /* End up with readline processing input, if necessary. */
3864 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3866 /* We're handling a live event, so make sure we're doing live
3867 debugging. If we're looking at traceframes while the target is
3868 running, we're going to need to get back to that mode after
3869 handling the event. */
3870 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3873 maybe_restore_traceframe
.emplace ();
3874 set_current_traceframe (-1);
3877 /* The user/frontend should not notice a thread switch due to
3878 internal events. Make sure we revert to the user selected
3879 thread and frame after handling the event and running any
3880 breakpoint commands. */
3881 scoped_restore_current_thread restore_thread
;
3883 overlay_cache_invalid
= 1;
3884 /* Flush target cache before starting to handle each event. Target
3885 was running and cache could be stale. This is just a heuristic.
3886 Running threads may modify target memory, but we don't get any
3888 target_dcache_invalidate ();
3890 scoped_restore save_exec_dir
3891 = make_scoped_restore (&execution_direction
,
3892 target_execution_direction ());
3894 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3897 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3899 /* Switch to the target that generated the event, so we can do
3901 switch_to_target_no_thread (ecs
->target
);
3904 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3906 /* If an error happens while handling the event, propagate GDB's
3907 knowledge of the executing state to the frontend/user running
3909 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3910 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3912 /* Get executed before scoped_restore_current_thread above to apply
3913 still for the thread which has thrown the exception. */
3914 auto defer_bpstat_clear
3915 = make_scope_exit (bpstat_clear_actions
);
3916 auto defer_delete_threads
3917 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3919 /* Now figure out what to do with the result of the result. */
3920 handle_inferior_event (ecs
);
3922 if (!ecs
->wait_some_more
)
3924 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3925 bool should_stop
= true;
3926 struct thread_info
*thr
= ecs
->event_thread
;
3928 delete_just_stopped_threads_infrun_breakpoints ();
3932 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3934 if (thread_fsm
!= NULL
)
3935 should_stop
= thread_fsm
->should_stop (thr
);
3944 bool should_notify_stop
= true;
3947 clean_up_just_stopped_threads_fsms (ecs
);
3949 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3950 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3952 if (should_notify_stop
)
3954 /* We may not find an inferior if this was a process exit. */
3955 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3956 proceeded
= normal_stop ();
3961 inferior_event_handler (INF_EXEC_COMPLETE
);
3965 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3966 previously selected thread is gone. We have two
3967 choices - switch to no thread selected, or restore the
3968 previously selected thread (now exited). We chose the
3969 later, just because that's what GDB used to do. After
3970 this, "info threads" says "The current thread <Thread
3971 ID 2> has terminated." instead of "No thread
3975 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3976 restore_thread
.dont_restore ();
3980 defer_delete_threads
.release ();
3981 defer_bpstat_clear
.release ();
3983 /* No error, don't finish the thread states yet. */
3984 finish_state
.release ();
3986 /* This scope is used to ensure that readline callbacks are
3987 reinstalled here. */
3990 /* If a UI was in sync execution mode, and now isn't, restore its
3991 prompt (a synchronous execution command has finished, and we're
3992 ready for input). */
3993 all_uis_check_sync_execution_done ();
3996 && exec_done_display_p
3997 && (inferior_ptid
== null_ptid
3998 || inferior_thread ()->state
!= THREAD_RUNNING
))
3999 printf_unfiltered (_("completed.\n"));
4005 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4006 struct symtab_and_line sal
)
4008 /* This can be removed once this function no longer implicitly relies on the
4009 inferior_ptid value. */
4010 gdb_assert (inferior_ptid
== tp
->ptid
);
4012 tp
->control
.step_frame_id
= get_frame_id (frame
);
4013 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4015 tp
->current_symtab
= sal
.symtab
;
4016 tp
->current_line
= sal
.line
;
4019 /* Clear context switchable stepping state. */
4022 init_thread_stepping_state (struct thread_info
*tss
)
4024 tss
->stepped_breakpoint
= 0;
4025 tss
->stepping_over_breakpoint
= 0;
4026 tss
->stepping_over_watchpoint
= 0;
4027 tss
->step_after_step_resume_breakpoint
= 0;
4033 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4034 target_waitstatus status
)
4036 target_last_proc_target
= target
;
4037 target_last_wait_ptid
= ptid
;
4038 target_last_waitstatus
= status
;
4044 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4045 target_waitstatus
*status
)
4047 if (target
!= nullptr)
4048 *target
= target_last_proc_target
;
4049 if (ptid
!= nullptr)
4050 *ptid
= target_last_wait_ptid
;
4051 if (status
!= nullptr)
4052 *status
= target_last_waitstatus
;
4058 nullify_last_target_wait_ptid (void)
4060 target_last_proc_target
= nullptr;
4061 target_last_wait_ptid
= minus_one_ptid
;
4062 target_last_waitstatus
= {};
4065 /* Switch thread contexts. */
4068 context_switch (execution_control_state
*ecs
)
4070 if (ecs
->ptid
!= inferior_ptid
4071 && (inferior_ptid
== null_ptid
4072 || ecs
->event_thread
!= inferior_thread ()))
4074 infrun_debug_printf ("Switching context from %s to %s",
4075 target_pid_to_str (inferior_ptid
).c_str (),
4076 target_pid_to_str (ecs
->ptid
).c_str ());
4079 switch_to_thread (ecs
->event_thread
);
4082 /* If the target can't tell whether we've hit breakpoints
4083 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4084 check whether that could have been caused by a breakpoint. If so,
4085 adjust the PC, per gdbarch_decr_pc_after_break. */
4088 adjust_pc_after_break (struct thread_info
*thread
,
4089 struct target_waitstatus
*ws
)
4091 struct regcache
*regcache
;
4092 struct gdbarch
*gdbarch
;
4093 CORE_ADDR breakpoint_pc
, decr_pc
;
4095 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4096 we aren't, just return.
4098 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4099 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4100 implemented by software breakpoints should be handled through the normal
4103 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4104 different signals (SIGILL or SIGEMT for instance), but it is less
4105 clear where the PC is pointing afterwards. It may not match
4106 gdbarch_decr_pc_after_break. I don't know any specific target that
4107 generates these signals at breakpoints (the code has been in GDB since at
4108 least 1992) so I can not guess how to handle them here.
4110 In earlier versions of GDB, a target with
4111 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4112 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4113 target with both of these set in GDB history, and it seems unlikely to be
4114 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4116 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4119 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4122 /* In reverse execution, when a breakpoint is hit, the instruction
4123 under it has already been de-executed. The reported PC always
4124 points at the breakpoint address, so adjusting it further would
4125 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4128 B1 0x08000000 : INSN1
4129 B2 0x08000001 : INSN2
4131 PC -> 0x08000003 : INSN4
4133 Say you're stopped at 0x08000003 as above. Reverse continuing
4134 from that point should hit B2 as below. Reading the PC when the
4135 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4136 been de-executed already.
4138 B1 0x08000000 : INSN1
4139 B2 PC -> 0x08000001 : INSN2
4143 We can't apply the same logic as for forward execution, because
4144 we would wrongly adjust the PC to 0x08000000, since there's a
4145 breakpoint at PC - 1. We'd then report a hit on B1, although
4146 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4148 if (execution_direction
== EXEC_REVERSE
)
4151 /* If the target can tell whether the thread hit a SW breakpoint,
4152 trust it. Targets that can tell also adjust the PC
4154 if (target_supports_stopped_by_sw_breakpoint ())
4157 /* Note that relying on whether a breakpoint is planted in memory to
4158 determine this can fail. E.g,. the breakpoint could have been
4159 removed since. Or the thread could have been told to step an
4160 instruction the size of a breakpoint instruction, and only
4161 _after_ was a breakpoint inserted at its address. */
4163 /* If this target does not decrement the PC after breakpoints, then
4164 we have nothing to do. */
4165 regcache
= get_thread_regcache (thread
);
4166 gdbarch
= regcache
->arch ();
4168 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4172 const address_space
*aspace
= regcache
->aspace ();
4174 /* Find the location where (if we've hit a breakpoint) the
4175 breakpoint would be. */
4176 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4178 /* If the target can't tell whether a software breakpoint triggered,
4179 fallback to figuring it out based on breakpoints we think were
4180 inserted in the target, and on whether the thread was stepped or
4183 /* Check whether there actually is a software breakpoint inserted at
4186 If in non-stop mode, a race condition is possible where we've
4187 removed a breakpoint, but stop events for that breakpoint were
4188 already queued and arrive later. To suppress those spurious
4189 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4190 and retire them after a number of stop events are reported. Note
4191 this is an heuristic and can thus get confused. The real fix is
4192 to get the "stopped by SW BP and needs adjustment" info out of
4193 the target/kernel (and thus never reach here; see above). */
4194 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4195 || (target_is_non_stop_p ()
4196 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4198 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4200 if (record_full_is_used ())
4201 restore_operation_disable
.emplace
4202 (record_full_gdb_operation_disable_set ());
4204 /* When using hardware single-step, a SIGTRAP is reported for both
4205 a completed single-step and a software breakpoint. Need to
4206 differentiate between the two, as the latter needs adjusting
4207 but the former does not.
4209 The SIGTRAP can be due to a completed hardware single-step only if
4210 - we didn't insert software single-step breakpoints
4211 - this thread is currently being stepped
4213 If any of these events did not occur, we must have stopped due
4214 to hitting a software breakpoint, and have to back up to the
4217 As a special case, we could have hardware single-stepped a
4218 software breakpoint. In this case (prev_pc == breakpoint_pc),
4219 we also need to back up to the breakpoint address. */
4221 if (thread_has_single_step_breakpoints_set (thread
)
4222 || !currently_stepping (thread
)
4223 || (thread
->stepped_breakpoint
4224 && thread
->prev_pc
== breakpoint_pc
))
4225 regcache_write_pc (regcache
, breakpoint_pc
);
4230 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4232 for (frame
= get_prev_frame (frame
);
4234 frame
= get_prev_frame (frame
))
4236 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4239 if (get_frame_type (frame
) != INLINE_FRAME
)
4246 /* Look for an inline frame that is marked for skip.
4247 If PREV_FRAME is TRUE start at the previous frame,
4248 otherwise start at the current frame. Stop at the
4249 first non-inline frame, or at the frame where the
4253 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4255 struct frame_info
*frame
= get_current_frame ();
4258 frame
= get_prev_frame (frame
);
4260 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4262 const char *fn
= NULL
;
4263 symtab_and_line sal
;
4266 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4268 if (get_frame_type (frame
) != INLINE_FRAME
)
4271 sal
= find_frame_sal (frame
);
4272 sym
= get_frame_function (frame
);
4275 fn
= sym
->print_name ();
4278 && function_name_is_marked_for_skip (fn
, sal
))
4285 /* If the event thread has the stop requested flag set, pretend it
4286 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4290 handle_stop_requested (struct execution_control_state
*ecs
)
4292 if (ecs
->event_thread
->stop_requested
)
4294 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4295 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4296 handle_signal_stop (ecs
);
4302 /* Auxiliary function that handles syscall entry/return events.
4303 It returns true if the inferior should keep going (and GDB
4304 should ignore the event), or false if the event deserves to be
4308 handle_syscall_event (struct execution_control_state
*ecs
)
4310 struct regcache
*regcache
;
4313 context_switch (ecs
);
4315 regcache
= get_thread_regcache (ecs
->event_thread
);
4316 syscall_number
= ecs
->ws
.value
.syscall_number
;
4317 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4319 if (catch_syscall_enabled () > 0
4320 && catching_syscall_number (syscall_number
) > 0)
4322 infrun_debug_printf ("syscall number=%d", syscall_number
);
4324 ecs
->event_thread
->control
.stop_bpstat
4325 = bpstat_stop_status (regcache
->aspace (),
4326 ecs
->event_thread
->suspend
.stop_pc
,
4327 ecs
->event_thread
, &ecs
->ws
);
4329 if (handle_stop_requested (ecs
))
4332 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4334 /* Catchpoint hit. */
4339 if (handle_stop_requested (ecs
))
4342 /* If no catchpoint triggered for this, then keep going. */
4348 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4351 fill_in_stop_func (struct gdbarch
*gdbarch
,
4352 struct execution_control_state
*ecs
)
4354 if (!ecs
->stop_func_filled_in
)
4357 const general_symbol_info
*gsi
;
4359 /* Don't care about return value; stop_func_start and stop_func_name
4360 will both be 0 if it doesn't work. */
4361 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4363 &ecs
->stop_func_start
,
4364 &ecs
->stop_func_end
,
4366 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4368 /* The call to find_pc_partial_function, above, will set
4369 stop_func_start and stop_func_end to the start and end
4370 of the range containing the stop pc. If this range
4371 contains the entry pc for the block (which is always the
4372 case for contiguous blocks), advance stop_func_start past
4373 the function's start offset and entrypoint. Note that
4374 stop_func_start is NOT advanced when in a range of a
4375 non-contiguous block that does not contain the entry pc. */
4376 if (block
!= nullptr
4377 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4378 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4380 ecs
->stop_func_start
4381 += gdbarch_deprecated_function_start_offset (gdbarch
);
4383 if (gdbarch_skip_entrypoint_p (gdbarch
))
4384 ecs
->stop_func_start
4385 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4388 ecs
->stop_func_filled_in
= 1;
4393 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4395 static enum stop_kind
4396 get_inferior_stop_soon (execution_control_state
*ecs
)
4398 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4400 gdb_assert (inf
!= NULL
);
4401 return inf
->control
.stop_soon
;
4404 /* Poll for one event out of the current target. Store the resulting
4405 waitstatus in WS, and return the event ptid. Does not block. */
4408 poll_one_curr_target (struct target_waitstatus
*ws
)
4412 overlay_cache_invalid
= 1;
4414 /* Flush target cache before starting to handle each event.
4415 Target was running and cache could be stale. This is just a
4416 heuristic. Running threads may modify target memory, but we
4417 don't get any event. */
4418 target_dcache_invalidate ();
4420 if (deprecated_target_wait_hook
)
4421 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4423 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4426 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4431 /* An event reported by wait_one. */
4433 struct wait_one_event
4435 /* The target the event came out of. */
4436 process_stratum_target
*target
;
4438 /* The PTID the event was for. */
4441 /* The waitstatus. */
4442 target_waitstatus ws
;
4445 /* Wait for one event out of any target. */
4447 static wait_one_event
4452 for (inferior
*inf
: all_inferiors ())
4454 process_stratum_target
*target
= inf
->process_target ();
4456 || !target
->is_async_p ()
4457 || !target
->threads_executing
)
4460 switch_to_inferior_no_thread (inf
);
4462 wait_one_event event
;
4463 event
.target
= target
;
4464 event
.ptid
= poll_one_curr_target (&event
.ws
);
4466 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4468 /* If nothing is resumed, remove the target from the
4472 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4476 /* Block waiting for some event. */
4483 for (inferior
*inf
: all_inferiors ())
4485 process_stratum_target
*target
= inf
->process_target ();
4487 || !target
->is_async_p ()
4488 || !target
->threads_executing
)
4491 int fd
= target
->async_wait_fd ();
4492 FD_SET (fd
, &readfds
);
4499 /* No waitable targets left. All must be stopped. */
4500 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4505 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4511 perror_with_name ("interruptible_select");
4516 /* Save the thread's event and stop reason to process it later. */
4519 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4521 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4522 target_waitstatus_to_string (ws
).c_str (),
4527 /* Record for later. */
4528 tp
->suspend
.waitstatus
= *ws
;
4529 tp
->suspend
.waitstatus_pending_p
= 1;
4531 struct regcache
*regcache
= get_thread_regcache (tp
);
4532 const address_space
*aspace
= regcache
->aspace ();
4534 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4535 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4537 CORE_ADDR pc
= regcache_read_pc (regcache
);
4539 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4541 scoped_restore_current_thread restore_thread
;
4542 switch_to_thread (tp
);
4544 if (target_stopped_by_watchpoint ())
4546 tp
->suspend
.stop_reason
4547 = TARGET_STOPPED_BY_WATCHPOINT
;
4549 else if (target_supports_stopped_by_sw_breakpoint ()
4550 && target_stopped_by_sw_breakpoint ())
4552 tp
->suspend
.stop_reason
4553 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4555 else if (target_supports_stopped_by_hw_breakpoint ()
4556 && target_stopped_by_hw_breakpoint ())
4558 tp
->suspend
.stop_reason
4559 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4561 else if (!target_supports_stopped_by_hw_breakpoint ()
4562 && hardware_breakpoint_inserted_here_p (aspace
,
4565 tp
->suspend
.stop_reason
4566 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4568 else if (!target_supports_stopped_by_sw_breakpoint ()
4569 && software_breakpoint_inserted_here_p (aspace
,
4572 tp
->suspend
.stop_reason
4573 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4575 else if (!thread_has_single_step_breakpoints_set (tp
)
4576 && currently_stepping (tp
))
4578 tp
->suspend
.stop_reason
4579 = TARGET_STOPPED_BY_SINGLE_STEP
;
4584 /* Mark the non-executing threads accordingly. In all-stop, all
4585 threads of all processes are stopped when we get any event
4586 reported. In non-stop mode, only the event thread stops. */
4589 mark_non_executing_threads (process_stratum_target
*target
,
4591 struct target_waitstatus ws
)
4595 if (!target_is_non_stop_p ())
4596 mark_ptid
= minus_one_ptid
;
4597 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4598 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4600 /* If we're handling a process exit in non-stop mode, even
4601 though threads haven't been deleted yet, one would think
4602 that there is nothing to do, as threads of the dead process
4603 will be soon deleted, and threads of any other process were
4604 left running. However, on some targets, threads survive a
4605 process exit event. E.g., for the "checkpoint" command,
4606 when the current checkpoint/fork exits, linux-fork.c
4607 automatically switches to another fork from within
4608 target_mourn_inferior, by associating the same
4609 inferior/thread to another fork. We haven't mourned yet at
4610 this point, but we must mark any threads left in the
4611 process as not-executing so that finish_thread_state marks
4612 them stopped (in the user's perspective) if/when we present
4613 the stop to the user. */
4614 mark_ptid
= ptid_t (event_ptid
.pid ());
4617 mark_ptid
= event_ptid
;
4619 set_executing (target
, mark_ptid
, false);
4621 /* Likewise the resumed flag. */
4622 set_resumed (target
, mark_ptid
, false);
4628 stop_all_threads (void)
4630 /* We may need multiple passes to discover all threads. */
4634 gdb_assert (exists_non_stop_target ());
4636 infrun_debug_printf ("starting");
4638 scoped_restore_current_thread restore_thread
;
4640 /* Enable thread events of all targets. */
4641 for (auto *target
: all_non_exited_process_targets ())
4643 switch_to_target_no_thread (target
);
4644 target_thread_events (true);
4649 /* Disable thread events of all targets. */
4650 for (auto *target
: all_non_exited_process_targets ())
4652 switch_to_target_no_thread (target
);
4653 target_thread_events (false);
4656 /* Use debug_prefixed_printf directly to get a meaningful function
4659 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4662 /* Request threads to stop, and then wait for the stops. Because
4663 threads we already know about can spawn more threads while we're
4664 trying to stop them, and we only learn about new threads when we
4665 update the thread list, do this in a loop, and keep iterating
4666 until two passes find no threads that need to be stopped. */
4667 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4669 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4672 int waits_needed
= 0;
4674 for (auto *target
: all_non_exited_process_targets ())
4676 switch_to_target_no_thread (target
);
4677 update_thread_list ();
4680 /* Go through all threads looking for threads that we need
4681 to tell the target to stop. */
4682 for (thread_info
*t
: all_non_exited_threads ())
4684 /* For a single-target setting with an all-stop target,
4685 we would not even arrive here. For a multi-target
4686 setting, until GDB is able to handle a mixture of
4687 all-stop and non-stop targets, simply skip all-stop
4688 targets' threads. This should be fine due to the
4689 protection of 'check_multi_target_resumption'. */
4691 switch_to_thread_no_regs (t
);
4692 if (!target_is_non_stop_p ())
4697 /* If already stopping, don't request a stop again.
4698 We just haven't seen the notification yet. */
4699 if (!t
->stop_requested
)
4701 infrun_debug_printf (" %s executing, need stop",
4702 target_pid_to_str (t
->ptid
).c_str ());
4703 target_stop (t
->ptid
);
4704 t
->stop_requested
= 1;
4708 infrun_debug_printf (" %s executing, already stopping",
4709 target_pid_to_str (t
->ptid
).c_str ());
4712 if (t
->stop_requested
)
4717 infrun_debug_printf (" %s not executing",
4718 target_pid_to_str (t
->ptid
).c_str ());
4720 /* The thread may be not executing, but still be
4721 resumed with a pending status to process. */
4726 if (waits_needed
== 0)
4729 /* If we find new threads on the second iteration, restart
4730 over. We want to see two iterations in a row with all
4735 for (int i
= 0; i
< waits_needed
; i
++)
4737 wait_one_event event
= wait_one ();
4740 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4741 target_pid_to_str (event
.ptid
).c_str ());
4743 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4745 /* All resumed threads exited. */
4748 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4749 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4750 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4752 /* One thread/process exited/signalled. */
4754 thread_info
*t
= nullptr;
4756 /* The target may have reported just a pid. If so, try
4757 the first non-exited thread. */
4758 if (event
.ptid
.is_pid ())
4760 int pid
= event
.ptid
.pid ();
4761 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4762 for (thread_info
*tp
: inf
->non_exited_threads ())
4768 /* If there is no available thread, the event would
4769 have to be appended to a per-inferior event list,
4770 which does not exist (and if it did, we'd have
4771 to adjust run control command to be able to
4772 resume such an inferior). We assert here instead
4773 of going into an infinite loop. */
4774 gdb_assert (t
!= nullptr);
4777 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4781 t
= find_thread_ptid (event
.target
, event
.ptid
);
4782 /* Check if this is the first time we see this thread.
4783 Don't bother adding if it individually exited. */
4785 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4786 t
= add_thread (event
.target
, event
.ptid
);
4791 /* Set the threads as non-executing to avoid
4792 another stop attempt on them. */
4793 switch_to_thread_no_regs (t
);
4794 mark_non_executing_threads (event
.target
, event
.ptid
,
4796 save_waitstatus (t
, &event
.ws
);
4797 t
->stop_requested
= false;
4802 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4804 t
= add_thread (event
.target
, event
.ptid
);
4806 t
->stop_requested
= 0;
4809 t
->control
.may_range_step
= 0;
4811 /* This may be the first time we see the inferior report
4813 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4814 if (inf
->needs_setup
)
4816 switch_to_thread_no_regs (t
);
4820 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4821 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4823 /* We caught the event that we intended to catch, so
4824 there's no event pending. */
4825 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4826 t
->suspend
.waitstatus_pending_p
= 0;
4828 if (displaced_step_finish (t
, GDB_SIGNAL_0
)
4829 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4831 /* Add it back to the step-over queue. */
4833 ("displaced-step of %s canceled: adding back to "
4834 "the step-over queue",
4835 target_pid_to_str (t
->ptid
).c_str ());
4837 t
->control
.trap_expected
= 0;
4838 global_thread_step_over_chain_enqueue (t
);
4843 enum gdb_signal sig
;
4844 struct regcache
*regcache
;
4847 ("target_wait %s, saving status for %d.%ld.%ld",
4848 target_waitstatus_to_string (&event
.ws
).c_str (),
4849 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4851 /* Record for later. */
4852 save_waitstatus (t
, &event
.ws
);
4854 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4855 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4857 if (displaced_step_finish (t
, sig
)
4858 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4860 /* Add it back to the step-over queue. */
4861 t
->control
.trap_expected
= 0;
4862 global_thread_step_over_chain_enqueue (t
);
4865 regcache
= get_thread_regcache (t
);
4866 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4868 infrun_debug_printf ("saved stop_pc=%s for %s "
4869 "(currently_stepping=%d)",
4870 paddress (target_gdbarch (),
4871 t
->suspend
.stop_pc
),
4872 target_pid_to_str (t
->ptid
).c_str (),
4873 currently_stepping (t
));
4881 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4884 handle_no_resumed (struct execution_control_state
*ecs
)
4886 if (target_can_async_p ())
4888 bool any_sync
= false;
4890 for (ui
*ui
: all_uis ())
4892 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4900 /* There were no unwaited-for children left in the target, but,
4901 we're not synchronously waiting for events either. Just
4904 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4905 prepare_to_wait (ecs
);
4910 /* Otherwise, if we were running a synchronous execution command, we
4911 may need to cancel it and give the user back the terminal.
4913 In non-stop mode, the target can't tell whether we've already
4914 consumed previous stop events, so it can end up sending us a
4915 no-resumed event like so:
4917 #0 - thread 1 is left stopped
4919 #1 - thread 2 is resumed and hits breakpoint
4920 -> TARGET_WAITKIND_STOPPED
4922 #2 - thread 3 is resumed and exits
4923 this is the last resumed thread, so
4924 -> TARGET_WAITKIND_NO_RESUMED
4926 #3 - gdb processes stop for thread 2 and decides to re-resume
4929 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4930 thread 2 is now resumed, so the event should be ignored.
4932 IOW, if the stop for thread 2 doesn't end a foreground command,
4933 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4934 event. But it could be that the event meant that thread 2 itself
4935 (or whatever other thread was the last resumed thread) exited.
4937 To address this we refresh the thread list and check whether we
4938 have resumed threads _now_. In the example above, this removes
4939 thread 3 from the thread list. If thread 2 was re-resumed, we
4940 ignore this event. If we find no thread resumed, then we cancel
4941 the synchronous command and show "no unwaited-for " to the
4944 inferior
*curr_inf
= current_inferior ();
4946 scoped_restore_current_thread restore_thread
;
4948 for (auto *target
: all_non_exited_process_targets ())
4950 switch_to_target_no_thread (target
);
4951 update_thread_list ();
4956 - the current target has no thread executing, and
4957 - the current inferior is native, and
4958 - the current inferior is the one which has the terminal, and
4961 then a Ctrl-C from this point on would remain stuck in the
4962 kernel, until a thread resumes and dequeues it. That would
4963 result in the GDB CLI not reacting to Ctrl-C, not able to
4964 interrupt the program. To address this, if the current inferior
4965 no longer has any thread executing, we give the terminal to some
4966 other inferior that has at least one thread executing. */
4967 bool swap_terminal
= true;
4969 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4970 whether to report it to the user. */
4971 bool ignore_event
= false;
4973 for (thread_info
*thread
: all_non_exited_threads ())
4975 if (swap_terminal
&& thread
->executing
)
4977 if (thread
->inf
!= curr_inf
)
4979 target_terminal::ours ();
4981 switch_to_thread (thread
);
4982 target_terminal::inferior ();
4984 swap_terminal
= false;
4988 && (thread
->executing
4989 || thread
->suspend
.waitstatus_pending_p
))
4991 /* Either there were no unwaited-for children left in the
4992 target at some point, but there are now, or some target
4993 other than the eventing one has unwaited-for children
4994 left. Just ignore. */
4995 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
4996 "(ignoring: found resumed)");
4998 ignore_event
= true;
5001 if (ignore_event
&& !swap_terminal
)
5007 switch_to_inferior_no_thread (curr_inf
);
5008 prepare_to_wait (ecs
);
5012 /* Go ahead and report the event. */
5016 /* Given an execution control state that has been freshly filled in by
5017 an event from the inferior, figure out what it means and take
5020 The alternatives are:
5022 1) stop_waiting and return; to really stop and return to the
5025 2) keep_going and return; to wait for the next event (set
5026 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5030 handle_inferior_event (struct execution_control_state
*ecs
)
5032 /* Make sure that all temporary struct value objects that were
5033 created during the handling of the event get deleted at the
5035 scoped_value_mark free_values
;
5037 enum stop_kind stop_soon
;
5039 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5041 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5043 /* We had an event in the inferior, but we are not interested in
5044 handling it at this level. The lower layers have already
5045 done what needs to be done, if anything.
5047 One of the possible circumstances for this is when the
5048 inferior produces output for the console. The inferior has
5049 not stopped, and we are ignoring the event. Another possible
5050 circumstance is any event which the lower level knows will be
5051 reported multiple times without an intervening resume. */
5052 prepare_to_wait (ecs
);
5056 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5058 prepare_to_wait (ecs
);
5062 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5063 && handle_no_resumed (ecs
))
5066 /* Cache the last target/ptid/waitstatus. */
5067 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5069 /* Always clear state belonging to the previous time we stopped. */
5070 stop_stack_dummy
= STOP_NONE
;
5072 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5074 /* No unwaited-for children left. IOW, all resumed children
5076 stop_print_frame
= false;
5081 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5082 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5084 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5085 /* If it's a new thread, add it to the thread database. */
5086 if (ecs
->event_thread
== NULL
)
5087 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5089 /* Disable range stepping. If the next step request could use a
5090 range, this will be end up re-enabled then. */
5091 ecs
->event_thread
->control
.may_range_step
= 0;
5094 /* Dependent on valid ECS->EVENT_THREAD. */
5095 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5097 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5098 reinit_frame_cache ();
5100 breakpoint_retire_moribund ();
5102 /* First, distinguish signals caused by the debugger from signals
5103 that have to do with the program's own actions. Note that
5104 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5105 on the operating system version. Here we detect when a SIGILL or
5106 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5107 something similar for SIGSEGV, since a SIGSEGV will be generated
5108 when we're trying to execute a breakpoint instruction on a
5109 non-executable stack. This happens for call dummy breakpoints
5110 for architectures like SPARC that place call dummies on the
5112 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5113 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5114 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5115 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5117 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5119 if (breakpoint_inserted_here_p (regcache
->aspace (),
5120 regcache_read_pc (regcache
)))
5122 infrun_debug_printf ("Treating signal as SIGTRAP");
5123 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5127 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5129 switch (ecs
->ws
.kind
)
5131 case TARGET_WAITKIND_LOADED
:
5132 context_switch (ecs
);
5133 /* Ignore gracefully during startup of the inferior, as it might
5134 be the shell which has just loaded some objects, otherwise
5135 add the symbols for the newly loaded objects. Also ignore at
5136 the beginning of an attach or remote session; we will query
5137 the full list of libraries once the connection is
5140 stop_soon
= get_inferior_stop_soon (ecs
);
5141 if (stop_soon
== NO_STOP_QUIETLY
)
5143 struct regcache
*regcache
;
5145 regcache
= get_thread_regcache (ecs
->event_thread
);
5147 handle_solib_event ();
5149 ecs
->event_thread
->control
.stop_bpstat
5150 = bpstat_stop_status (regcache
->aspace (),
5151 ecs
->event_thread
->suspend
.stop_pc
,
5152 ecs
->event_thread
, &ecs
->ws
);
5154 if (handle_stop_requested (ecs
))
5157 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5159 /* A catchpoint triggered. */
5160 process_event_stop_test (ecs
);
5164 /* If requested, stop when the dynamic linker notifies
5165 gdb of events. This allows the user to get control
5166 and place breakpoints in initializer routines for
5167 dynamically loaded objects (among other things). */
5168 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5169 if (stop_on_solib_events
)
5171 /* Make sure we print "Stopped due to solib-event" in
5173 stop_print_frame
= true;
5180 /* If we are skipping through a shell, or through shared library
5181 loading that we aren't interested in, resume the program. If
5182 we're running the program normally, also resume. */
5183 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5185 /* Loading of shared libraries might have changed breakpoint
5186 addresses. Make sure new breakpoints are inserted. */
5187 if (stop_soon
== NO_STOP_QUIETLY
)
5188 insert_breakpoints ();
5189 resume (GDB_SIGNAL_0
);
5190 prepare_to_wait (ecs
);
5194 /* But stop if we're attaching or setting up a remote
5196 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5197 || stop_soon
== STOP_QUIETLY_REMOTE
)
5199 infrun_debug_printf ("quietly stopped");
5204 internal_error (__FILE__
, __LINE__
,
5205 _("unhandled stop_soon: %d"), (int) stop_soon
);
5207 case TARGET_WAITKIND_SPURIOUS
:
5208 if (handle_stop_requested (ecs
))
5210 context_switch (ecs
);
5211 resume (GDB_SIGNAL_0
);
5212 prepare_to_wait (ecs
);
5215 case TARGET_WAITKIND_THREAD_CREATED
:
5216 if (handle_stop_requested (ecs
))
5218 context_switch (ecs
);
5219 if (!switch_back_to_stepped_thread (ecs
))
5223 case TARGET_WAITKIND_EXITED
:
5224 case TARGET_WAITKIND_SIGNALLED
:
5226 /* Depending on the system, ecs->ptid may point to a thread or
5227 to a process. On some targets, target_mourn_inferior may
5228 need to have access to the just-exited thread. That is the
5229 case of GNU/Linux's "checkpoint" support, for example.
5230 Call the switch_to_xxx routine as appropriate. */
5231 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5233 switch_to_thread (thr
);
5236 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5237 switch_to_inferior_no_thread (inf
);
5240 handle_vfork_child_exec_or_exit (0);
5241 target_terminal::ours (); /* Must do this before mourn anyway. */
5243 /* Clearing any previous state of convenience variables. */
5244 clear_exit_convenience_vars ();
5246 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5248 /* Record the exit code in the convenience variable $_exitcode, so
5249 that the user can inspect this again later. */
5250 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5251 (LONGEST
) ecs
->ws
.value
.integer
);
5253 /* Also record this in the inferior itself. */
5254 current_inferior ()->has_exit_code
= 1;
5255 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5257 /* Support the --return-child-result option. */
5258 return_child_result_value
= ecs
->ws
.value
.integer
;
5260 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5264 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5266 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5268 /* Set the value of the internal variable $_exitsignal,
5269 which holds the signal uncaught by the inferior. */
5270 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5271 gdbarch_gdb_signal_to_target (gdbarch
,
5272 ecs
->ws
.value
.sig
));
5276 /* We don't have access to the target's method used for
5277 converting between signal numbers (GDB's internal
5278 representation <-> target's representation).
5279 Therefore, we cannot do a good job at displaying this
5280 information to the user. It's better to just warn
5281 her about it (if infrun debugging is enabled), and
5283 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5287 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5290 gdb_flush (gdb_stdout
);
5291 target_mourn_inferior (inferior_ptid
);
5292 stop_print_frame
= false;
5296 case TARGET_WAITKIND_FORKED
:
5297 case TARGET_WAITKIND_VFORKED
:
5298 /* Check whether the inferior is displaced stepping. */
5300 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5301 struct gdbarch
*gdbarch
= regcache
->arch ();
5302 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5304 /* If this is a fork (child gets its own address space copy) and the
5305 displaced step buffer was in use at the time of the fork, restore
5306 displaced step buffer bytes in the child process. */
5307 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5309 displaced_step_inferior_state
*displaced
5310 = &parent_inf
->displaced_step_state
;
5312 if (displaced
->step_thread
!= nullptr)
5313 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5316 /* If displaced stepping is supported, and thread ecs->ptid is
5317 displaced stepping. */
5318 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5320 struct regcache
*child_regcache
;
5321 CORE_ADDR parent_pc
;
5323 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5324 indicating that the displaced stepping of syscall instruction
5325 has been done. Perform cleanup for parent process here. Note
5326 that this operation also cleans up the child process for vfork,
5327 because their pages are shared. */
5328 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5329 /* Start a new step-over in another thread if there's one
5333 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5334 the child's PC is also within the scratchpad. Set the child's PC
5335 to the parent's PC value, which has already been fixed up.
5336 FIXME: we use the parent's aspace here, although we're touching
5337 the child, because the child hasn't been added to the inferior
5338 list yet at this point. */
5341 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5342 ecs
->ws
.value
.related_pid
,
5344 parent_inf
->aspace
);
5345 /* Read PC value of parent process. */
5346 parent_pc
= regcache_read_pc (regcache
);
5348 displaced_debug_printf ("write child pc from %s to %s",
5350 regcache_read_pc (child_regcache
)),
5351 paddress (gdbarch
, parent_pc
));
5353 regcache_write_pc (child_regcache
, parent_pc
);
5357 context_switch (ecs
);
5359 /* Immediately detach breakpoints from the child before there's
5360 any chance of letting the user delete breakpoints from the
5361 breakpoint lists. If we don't do this early, it's easy to
5362 leave left over traps in the child, vis: "break foo; catch
5363 fork; c; <fork>; del; c; <child calls foo>". We only follow
5364 the fork on the last `continue', and by that time the
5365 breakpoint at "foo" is long gone from the breakpoint table.
5366 If we vforked, then we don't need to unpatch here, since both
5367 parent and child are sharing the same memory pages; we'll
5368 need to unpatch at follow/detach time instead to be certain
5369 that new breakpoints added between catchpoint hit time and
5370 vfork follow are detached. */
5371 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5373 /* This won't actually modify the breakpoint list, but will
5374 physically remove the breakpoints from the child. */
5375 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5378 delete_just_stopped_threads_single_step_breakpoints ();
5380 /* In case the event is caught by a catchpoint, remember that
5381 the event is to be followed at the next resume of the thread,
5382 and not immediately. */
5383 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5385 ecs
->event_thread
->suspend
.stop_pc
5386 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5388 ecs
->event_thread
->control
.stop_bpstat
5389 = bpstat_stop_status (get_current_regcache ()->aspace (),
5390 ecs
->event_thread
->suspend
.stop_pc
,
5391 ecs
->event_thread
, &ecs
->ws
);
5393 if (handle_stop_requested (ecs
))
5396 /* If no catchpoint triggered for this, then keep going. Note
5397 that we're interested in knowing the bpstat actually causes a
5398 stop, not just if it may explain the signal. Software
5399 watchpoints, for example, always appear in the bpstat. */
5400 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5403 = (follow_fork_mode_string
== follow_fork_mode_child
);
5405 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5407 process_stratum_target
*targ
5408 = ecs
->event_thread
->inf
->process_target ();
5410 bool should_resume
= follow_fork ();
5412 /* Note that one of these may be an invalid pointer,
5413 depending on detach_fork. */
5414 thread_info
*parent
= ecs
->event_thread
;
5416 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5418 /* At this point, the parent is marked running, and the
5419 child is marked stopped. */
5421 /* If not resuming the parent, mark it stopped. */
5422 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5423 parent
->set_running (false);
5425 /* If resuming the child, mark it running. */
5426 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5427 child
->set_running (true);
5429 /* In non-stop mode, also resume the other branch. */
5430 if (!detach_fork
&& (non_stop
5431 || (sched_multi
&& target_is_non_stop_p ())))
5434 switch_to_thread (parent
);
5436 switch_to_thread (child
);
5438 ecs
->event_thread
= inferior_thread ();
5439 ecs
->ptid
= inferior_ptid
;
5444 switch_to_thread (child
);
5446 switch_to_thread (parent
);
5448 ecs
->event_thread
= inferior_thread ();
5449 ecs
->ptid
= inferior_ptid
;
5457 process_event_stop_test (ecs
);
5460 case TARGET_WAITKIND_VFORK_DONE
:
5461 /* Done with the shared memory region. Re-insert breakpoints in
5462 the parent, and keep going. */
5464 context_switch (ecs
);
5466 current_inferior ()->waiting_for_vfork_done
= 0;
5467 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5469 if (handle_stop_requested (ecs
))
5472 /* This also takes care of reinserting breakpoints in the
5473 previously locked inferior. */
5477 case TARGET_WAITKIND_EXECD
:
5479 /* Note we can't read registers yet (the stop_pc), because we
5480 don't yet know the inferior's post-exec architecture.
5481 'stop_pc' is explicitly read below instead. */
5482 switch_to_thread_no_regs (ecs
->event_thread
);
5484 /* Do whatever is necessary to the parent branch of the vfork. */
5485 handle_vfork_child_exec_or_exit (1);
5487 /* This causes the eventpoints and symbol table to be reset.
5488 Must do this now, before trying to determine whether to
5490 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5492 /* In follow_exec we may have deleted the original thread and
5493 created a new one. Make sure that the event thread is the
5494 execd thread for that case (this is a nop otherwise). */
5495 ecs
->event_thread
= inferior_thread ();
5497 ecs
->event_thread
->suspend
.stop_pc
5498 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5500 ecs
->event_thread
->control
.stop_bpstat
5501 = bpstat_stop_status (get_current_regcache ()->aspace (),
5502 ecs
->event_thread
->suspend
.stop_pc
,
5503 ecs
->event_thread
, &ecs
->ws
);
5505 /* Note that this may be referenced from inside
5506 bpstat_stop_status above, through inferior_has_execd. */
5507 xfree (ecs
->ws
.value
.execd_pathname
);
5508 ecs
->ws
.value
.execd_pathname
= NULL
;
5510 if (handle_stop_requested (ecs
))
5513 /* If no catchpoint triggered for this, then keep going. */
5514 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5516 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5520 process_event_stop_test (ecs
);
5523 /* Be careful not to try to gather much state about a thread
5524 that's in a syscall. It's frequently a losing proposition. */
5525 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5526 /* Getting the current syscall number. */
5527 if (handle_syscall_event (ecs
) == 0)
5528 process_event_stop_test (ecs
);
5531 /* Before examining the threads further, step this thread to
5532 get it entirely out of the syscall. (We get notice of the
5533 event when the thread is just on the verge of exiting a
5534 syscall. Stepping one instruction seems to get it back
5536 case TARGET_WAITKIND_SYSCALL_RETURN
:
5537 if (handle_syscall_event (ecs
) == 0)
5538 process_event_stop_test (ecs
);
5541 case TARGET_WAITKIND_STOPPED
:
5542 handle_signal_stop (ecs
);
5545 case TARGET_WAITKIND_NO_HISTORY
:
5546 /* Reverse execution: target ran out of history info. */
5548 /* Switch to the stopped thread. */
5549 context_switch (ecs
);
5550 infrun_debug_printf ("stopped");
5552 delete_just_stopped_threads_single_step_breakpoints ();
5553 ecs
->event_thread
->suspend
.stop_pc
5554 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5556 if (handle_stop_requested (ecs
))
5559 gdb::observers::no_history
.notify ();
5565 /* Restart threads back to what they were trying to do back when we
5566 paused them for an in-line step-over. The EVENT_THREAD thread is
5570 restart_threads (struct thread_info
*event_thread
)
5572 /* In case the instruction just stepped spawned a new thread. */
5573 update_thread_list ();
5575 for (thread_info
*tp
: all_non_exited_threads ())
5577 switch_to_thread_no_regs (tp
);
5579 if (tp
== event_thread
)
5581 infrun_debug_printf ("restart threads: [%s] is event thread",
5582 target_pid_to_str (tp
->ptid
).c_str ());
5586 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5588 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5589 target_pid_to_str (tp
->ptid
).c_str ());
5595 infrun_debug_printf ("restart threads: [%s] resumed",
5596 target_pid_to_str (tp
->ptid
).c_str ());
5597 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5601 if (thread_is_in_step_over_chain (tp
))
5603 infrun_debug_printf ("restart threads: [%s] needs step-over",
5604 target_pid_to_str (tp
->ptid
).c_str ());
5605 gdb_assert (!tp
->resumed
);
5610 if (tp
->suspend
.waitstatus_pending_p
)
5612 infrun_debug_printf ("restart threads: [%s] has pending status",
5613 target_pid_to_str (tp
->ptid
).c_str ());
5618 gdb_assert (!tp
->stop_requested
);
5620 /* If some thread needs to start a step-over at this point, it
5621 should still be in the step-over queue, and thus skipped
5623 if (thread_still_needs_step_over (tp
))
5625 internal_error (__FILE__
, __LINE__
,
5626 "thread [%s] needs a step-over, but not in "
5627 "step-over queue\n",
5628 target_pid_to_str (tp
->ptid
).c_str ());
5631 if (currently_stepping (tp
))
5633 infrun_debug_printf ("restart threads: [%s] was stepping",
5634 target_pid_to_str (tp
->ptid
).c_str ());
5635 keep_going_stepped_thread (tp
);
5639 struct execution_control_state ecss
;
5640 struct execution_control_state
*ecs
= &ecss
;
5642 infrun_debug_printf ("restart threads: [%s] continuing",
5643 target_pid_to_str (tp
->ptid
).c_str ());
5644 reset_ecs (ecs
, tp
);
5645 switch_to_thread (tp
);
5646 keep_going_pass_signal (ecs
);
5651 /* Callback for iterate_over_threads. Find a resumed thread that has
5652 a pending waitstatus. */
5655 resumed_thread_with_pending_status (struct thread_info
*tp
,
5659 && tp
->suspend
.waitstatus_pending_p
);
5662 /* Called when we get an event that may finish an in-line or
5663 out-of-line (displaced stepping) step-over started previously.
5664 Return true if the event is processed and we should go back to the
5665 event loop; false if the caller should continue processing the
5669 finish_step_over (struct execution_control_state
*ecs
)
5671 displaced_step_finish (ecs
->event_thread
,
5672 ecs
->event_thread
->suspend
.stop_signal
);
5674 bool had_step_over_info
= step_over_info_valid_p ();
5676 if (had_step_over_info
)
5678 /* If we're stepping over a breakpoint with all threads locked,
5679 then only the thread that was stepped should be reporting
5681 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5683 clear_step_over_info ();
5686 if (!target_is_non_stop_p ())
5689 /* Start a new step-over in another thread if there's one that
5693 /* If we were stepping over a breakpoint before, and haven't started
5694 a new in-line step-over sequence, then restart all other threads
5695 (except the event thread). We can't do this in all-stop, as then
5696 e.g., we wouldn't be able to issue any other remote packet until
5697 these other threads stop. */
5698 if (had_step_over_info
&& !step_over_info_valid_p ())
5700 struct thread_info
*pending
;
5702 /* If we only have threads with pending statuses, the restart
5703 below won't restart any thread and so nothing re-inserts the
5704 breakpoint we just stepped over. But we need it inserted
5705 when we later process the pending events, otherwise if
5706 another thread has a pending event for this breakpoint too,
5707 we'd discard its event (because the breakpoint that
5708 originally caused the event was no longer inserted). */
5709 context_switch (ecs
);
5710 insert_breakpoints ();
5712 restart_threads (ecs
->event_thread
);
5714 /* If we have events pending, go through handle_inferior_event
5715 again, picking up a pending event at random. This avoids
5716 thread starvation. */
5718 /* But not if we just stepped over a watchpoint in order to let
5719 the instruction execute so we can evaluate its expression.
5720 The set of watchpoints that triggered is recorded in the
5721 breakpoint objects themselves (see bp->watchpoint_triggered).
5722 If we processed another event first, that other event could
5723 clobber this info. */
5724 if (ecs
->event_thread
->stepping_over_watchpoint
)
5727 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5729 if (pending
!= NULL
)
5731 struct thread_info
*tp
= ecs
->event_thread
;
5732 struct regcache
*regcache
;
5734 infrun_debug_printf ("found resumed threads with "
5735 "pending events, saving status");
5737 gdb_assert (pending
!= tp
);
5739 /* Record the event thread's event for later. */
5740 save_waitstatus (tp
, &ecs
->ws
);
5741 /* This was cleared early, by handle_inferior_event. Set it
5742 so this pending event is considered by
5746 gdb_assert (!tp
->executing
);
5748 regcache
= get_thread_regcache (tp
);
5749 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5751 infrun_debug_printf ("saved stop_pc=%s for %s "
5752 "(currently_stepping=%d)",
5753 paddress (target_gdbarch (),
5754 tp
->suspend
.stop_pc
),
5755 target_pid_to_str (tp
->ptid
).c_str (),
5756 currently_stepping (tp
));
5758 /* This in-line step-over finished; clear this so we won't
5759 start a new one. This is what handle_signal_stop would
5760 do, if we returned false. */
5761 tp
->stepping_over_breakpoint
= 0;
5763 /* Wake up the event loop again. */
5764 mark_async_event_handler (infrun_async_inferior_event_token
);
5766 prepare_to_wait (ecs
);
5774 /* Come here when the program has stopped with a signal. */
5777 handle_signal_stop (struct execution_control_state
*ecs
)
5779 struct frame_info
*frame
;
5780 struct gdbarch
*gdbarch
;
5781 int stopped_by_watchpoint
;
5782 enum stop_kind stop_soon
;
5785 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5787 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5789 /* Do we need to clean up the state of a thread that has
5790 completed a displaced single-step? (Doing so usually affects
5791 the PC, so do it here, before we set stop_pc.) */
5792 if (finish_step_over (ecs
))
5795 /* If we either finished a single-step or hit a breakpoint, but
5796 the user wanted this thread to be stopped, pretend we got a
5797 SIG0 (generic unsignaled stop). */
5798 if (ecs
->event_thread
->stop_requested
5799 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5800 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5802 ecs
->event_thread
->suspend
.stop_pc
5803 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5807 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5808 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5810 switch_to_thread (ecs
->event_thread
);
5812 infrun_debug_printf ("stop_pc=%s",
5813 paddress (reg_gdbarch
,
5814 ecs
->event_thread
->suspend
.stop_pc
));
5815 if (target_stopped_by_watchpoint ())
5819 infrun_debug_printf ("stopped by watchpoint");
5821 if (target_stopped_data_address (current_top_target (), &addr
))
5822 infrun_debug_printf ("stopped data address=%s",
5823 paddress (reg_gdbarch
, addr
));
5825 infrun_debug_printf ("(no data address available)");
5829 /* This is originated from start_remote(), start_inferior() and
5830 shared libraries hook functions. */
5831 stop_soon
= get_inferior_stop_soon (ecs
);
5832 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5834 context_switch (ecs
);
5835 infrun_debug_printf ("quietly stopped");
5836 stop_print_frame
= true;
5841 /* This originates from attach_command(). We need to overwrite
5842 the stop_signal here, because some kernels don't ignore a
5843 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5844 See more comments in inferior.h. On the other hand, if we
5845 get a non-SIGSTOP, report it to the user - assume the backend
5846 will handle the SIGSTOP if it should show up later.
5848 Also consider that the attach is complete when we see a
5849 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5850 target extended-remote report it instead of a SIGSTOP
5851 (e.g. gdbserver). We already rely on SIGTRAP being our
5852 signal, so this is no exception.
5854 Also consider that the attach is complete when we see a
5855 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5856 the target to stop all threads of the inferior, in case the
5857 low level attach operation doesn't stop them implicitly. If
5858 they weren't stopped implicitly, then the stub will report a
5859 GDB_SIGNAL_0, meaning: stopped for no particular reason
5860 other than GDB's request. */
5861 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5862 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5863 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5864 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5866 stop_print_frame
= true;
5868 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5872 /* See if something interesting happened to the non-current thread. If
5873 so, then switch to that thread. */
5874 if (ecs
->ptid
!= inferior_ptid
)
5876 infrun_debug_printf ("context switch");
5878 context_switch (ecs
);
5880 if (deprecated_context_hook
)
5881 deprecated_context_hook (ecs
->event_thread
->global_num
);
5884 /* At this point, get hold of the now-current thread's frame. */
5885 frame
= get_current_frame ();
5886 gdbarch
= get_frame_arch (frame
);
5888 /* Pull the single step breakpoints out of the target. */
5889 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5891 struct regcache
*regcache
;
5894 regcache
= get_thread_regcache (ecs
->event_thread
);
5895 const address_space
*aspace
= regcache
->aspace ();
5897 pc
= regcache_read_pc (regcache
);
5899 /* However, before doing so, if this single-step breakpoint was
5900 actually for another thread, set this thread up for moving
5902 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5905 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5907 infrun_debug_printf ("[%s] hit another thread's single-step "
5909 target_pid_to_str (ecs
->ptid
).c_str ());
5910 ecs
->hit_singlestep_breakpoint
= 1;
5915 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5916 target_pid_to_str (ecs
->ptid
).c_str ());
5919 delete_just_stopped_threads_single_step_breakpoints ();
5921 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5922 && ecs
->event_thread
->control
.trap_expected
5923 && ecs
->event_thread
->stepping_over_watchpoint
)
5924 stopped_by_watchpoint
= 0;
5926 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5928 /* If necessary, step over this watchpoint. We'll be back to display
5930 if (stopped_by_watchpoint
5931 && (target_have_steppable_watchpoint ()
5932 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5934 /* At this point, we are stopped at an instruction which has
5935 attempted to write to a piece of memory under control of
5936 a watchpoint. The instruction hasn't actually executed
5937 yet. If we were to evaluate the watchpoint expression
5938 now, we would get the old value, and therefore no change
5939 would seem to have occurred.
5941 In order to make watchpoints work `right', we really need
5942 to complete the memory write, and then evaluate the
5943 watchpoint expression. We do this by single-stepping the
5946 It may not be necessary to disable the watchpoint to step over
5947 it. For example, the PA can (with some kernel cooperation)
5948 single step over a watchpoint without disabling the watchpoint.
5950 It is far more common to need to disable a watchpoint to step
5951 the inferior over it. If we have non-steppable watchpoints,
5952 we must disable the current watchpoint; it's simplest to
5953 disable all watchpoints.
5955 Any breakpoint at PC must also be stepped over -- if there's
5956 one, it will have already triggered before the watchpoint
5957 triggered, and we either already reported it to the user, or
5958 it didn't cause a stop and we called keep_going. In either
5959 case, if there was a breakpoint at PC, we must be trying to
5961 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5966 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5967 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5968 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5969 ecs
->event_thread
->control
.stop_step
= 0;
5970 stop_print_frame
= true;
5971 stopped_by_random_signal
= 0;
5972 bpstat stop_chain
= NULL
;
5974 /* Hide inlined functions starting here, unless we just performed stepi or
5975 nexti. After stepi and nexti, always show the innermost frame (not any
5976 inline function call sites). */
5977 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5979 const address_space
*aspace
5980 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5982 /* skip_inline_frames is expensive, so we avoid it if we can
5983 determine that the address is one where functions cannot have
5984 been inlined. This improves performance with inferiors that
5985 load a lot of shared libraries, because the solib event
5986 breakpoint is defined as the address of a function (i.e. not
5987 inline). Note that we have to check the previous PC as well
5988 as the current one to catch cases when we have just
5989 single-stepped off a breakpoint prior to reinstating it.
5990 Note that we're assuming that the code we single-step to is
5991 not inline, but that's not definitive: there's nothing
5992 preventing the event breakpoint function from containing
5993 inlined code, and the single-step ending up there. If the
5994 user had set a breakpoint on that inlined code, the missing
5995 skip_inline_frames call would break things. Fortunately
5996 that's an extremely unlikely scenario. */
5997 if (!pc_at_non_inline_function (aspace
,
5998 ecs
->event_thread
->suspend
.stop_pc
,
6000 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6001 && ecs
->event_thread
->control
.trap_expected
6002 && pc_at_non_inline_function (aspace
,
6003 ecs
->event_thread
->prev_pc
,
6006 stop_chain
= build_bpstat_chain (aspace
,
6007 ecs
->event_thread
->suspend
.stop_pc
,
6009 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6011 /* Re-fetch current thread's frame in case that invalidated
6013 frame
= get_current_frame ();
6014 gdbarch
= get_frame_arch (frame
);
6018 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6019 && ecs
->event_thread
->control
.trap_expected
6020 && gdbarch_single_step_through_delay_p (gdbarch
)
6021 && currently_stepping (ecs
->event_thread
))
6023 /* We're trying to step off a breakpoint. Turns out that we're
6024 also on an instruction that needs to be stepped multiple
6025 times before it's been fully executing. E.g., architectures
6026 with a delay slot. It needs to be stepped twice, once for
6027 the instruction and once for the delay slot. */
6028 int step_through_delay
6029 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6031 if (step_through_delay
)
6032 infrun_debug_printf ("step through delay");
6034 if (ecs
->event_thread
->control
.step_range_end
== 0
6035 && step_through_delay
)
6037 /* The user issued a continue when stopped at a breakpoint.
6038 Set up for another trap and get out of here. */
6039 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6043 else if (step_through_delay
)
6045 /* The user issued a step when stopped at a breakpoint.
6046 Maybe we should stop, maybe we should not - the delay
6047 slot *might* correspond to a line of source. In any
6048 case, don't decide that here, just set
6049 ecs->stepping_over_breakpoint, making sure we
6050 single-step again before breakpoints are re-inserted. */
6051 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6055 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6056 handles this event. */
6057 ecs
->event_thread
->control
.stop_bpstat
6058 = bpstat_stop_status (get_current_regcache ()->aspace (),
6059 ecs
->event_thread
->suspend
.stop_pc
,
6060 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6062 /* Following in case break condition called a
6064 stop_print_frame
= true;
6066 /* This is where we handle "moribund" watchpoints. Unlike
6067 software breakpoints traps, hardware watchpoint traps are
6068 always distinguishable from random traps. If no high-level
6069 watchpoint is associated with the reported stop data address
6070 anymore, then the bpstat does not explain the signal ---
6071 simply make sure to ignore it if `stopped_by_watchpoint' is
6074 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6075 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6077 && stopped_by_watchpoint
)
6079 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6083 /* NOTE: cagney/2003-03-29: These checks for a random signal
6084 at one stage in the past included checks for an inferior
6085 function call's call dummy's return breakpoint. The original
6086 comment, that went with the test, read:
6088 ``End of a stack dummy. Some systems (e.g. Sony news) give
6089 another signal besides SIGTRAP, so check here as well as
6092 If someone ever tries to get call dummys on a
6093 non-executable stack to work (where the target would stop
6094 with something like a SIGSEGV), then those tests might need
6095 to be re-instated. Given, however, that the tests were only
6096 enabled when momentary breakpoints were not being used, I
6097 suspect that it won't be the case.
6099 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6100 be necessary for call dummies on a non-executable stack on
6103 /* See if the breakpoints module can explain the signal. */
6105 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6106 ecs
->event_thread
->suspend
.stop_signal
);
6108 /* Maybe this was a trap for a software breakpoint that has since
6110 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6112 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6113 ecs
->event_thread
->suspend
.stop_pc
))
6115 struct regcache
*regcache
;
6118 /* Re-adjust PC to what the program would see if GDB was not
6120 regcache
= get_thread_regcache (ecs
->event_thread
);
6121 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6124 gdb::optional
<scoped_restore_tmpl
<int>>
6125 restore_operation_disable
;
6127 if (record_full_is_used ())
6128 restore_operation_disable
.emplace
6129 (record_full_gdb_operation_disable_set ());
6131 regcache_write_pc (regcache
,
6132 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6137 /* A delayed software breakpoint event. Ignore the trap. */
6138 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6143 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6144 has since been removed. */
6145 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6147 /* A delayed hardware breakpoint event. Ignore the trap. */
6148 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6153 /* If not, perhaps stepping/nexting can. */
6155 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6156 && currently_stepping (ecs
->event_thread
));
6158 /* Perhaps the thread hit a single-step breakpoint of _another_
6159 thread. Single-step breakpoints are transparent to the
6160 breakpoints module. */
6162 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6164 /* No? Perhaps we got a moribund watchpoint. */
6166 random_signal
= !stopped_by_watchpoint
;
6168 /* Always stop if the user explicitly requested this thread to
6170 if (ecs
->event_thread
->stop_requested
)
6173 infrun_debug_printf ("user-requested stop");
6176 /* For the program's own signals, act according to
6177 the signal handling tables. */
6181 /* Signal not for debugging purposes. */
6182 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6183 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6185 infrun_debug_printf ("random signal (%s)",
6186 gdb_signal_to_symbol_string (stop_signal
));
6188 stopped_by_random_signal
= 1;
6190 /* Always stop on signals if we're either just gaining control
6191 of the program, or the user explicitly requested this thread
6192 to remain stopped. */
6193 if (stop_soon
!= NO_STOP_QUIETLY
6194 || ecs
->event_thread
->stop_requested
6196 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6202 /* Notify observers the signal has "handle print" set. Note we
6203 returned early above if stopping; normal_stop handles the
6204 printing in that case. */
6205 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6207 /* The signal table tells us to print about this signal. */
6208 target_terminal::ours_for_output ();
6209 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6210 target_terminal::inferior ();
6213 /* Clear the signal if it should not be passed. */
6214 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6215 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6217 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6218 && ecs
->event_thread
->control
.trap_expected
6219 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6221 /* We were just starting a new sequence, attempting to
6222 single-step off of a breakpoint and expecting a SIGTRAP.
6223 Instead this signal arrives. This signal will take us out
6224 of the stepping range so GDB needs to remember to, when
6225 the signal handler returns, resume stepping off that
6227 /* To simplify things, "continue" is forced to use the same
6228 code paths as single-step - set a breakpoint at the
6229 signal return address and then, once hit, step off that
6231 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6233 insert_hp_step_resume_breakpoint_at_frame (frame
);
6234 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6235 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6236 ecs
->event_thread
->control
.trap_expected
= 0;
6238 /* If we were nexting/stepping some other thread, switch to
6239 it, so that we don't continue it, losing control. */
6240 if (!switch_back_to_stepped_thread (ecs
))
6245 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6246 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6248 || ecs
->event_thread
->control
.step_range_end
== 1)
6249 && frame_id_eq (get_stack_frame_id (frame
),
6250 ecs
->event_thread
->control
.step_stack_frame_id
)
6251 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6253 /* The inferior is about to take a signal that will take it
6254 out of the single step range. Set a breakpoint at the
6255 current PC (which is presumably where the signal handler
6256 will eventually return) and then allow the inferior to
6259 Note that this is only needed for a signal delivered
6260 while in the single-step range. Nested signals aren't a
6261 problem as they eventually all return. */
6262 infrun_debug_printf ("signal may take us out of single-step range");
6264 clear_step_over_info ();
6265 insert_hp_step_resume_breakpoint_at_frame (frame
);
6266 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6267 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6268 ecs
->event_thread
->control
.trap_expected
= 0;
6273 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6274 when either there's a nested signal, or when there's a
6275 pending signal enabled just as the signal handler returns
6276 (leaving the inferior at the step-resume-breakpoint without
6277 actually executing it). Either way continue until the
6278 breakpoint is really hit. */
6280 if (!switch_back_to_stepped_thread (ecs
))
6282 infrun_debug_printf ("random signal, keep going");
6289 process_event_stop_test (ecs
);
6292 /* Come here when we've got some debug event / signal we can explain
6293 (IOW, not a random signal), and test whether it should cause a
6294 stop, or whether we should resume the inferior (transparently).
6295 E.g., could be a breakpoint whose condition evaluates false; we
6296 could be still stepping within the line; etc. */
6299 process_event_stop_test (struct execution_control_state
*ecs
)
6301 struct symtab_and_line stop_pc_sal
;
6302 struct frame_info
*frame
;
6303 struct gdbarch
*gdbarch
;
6304 CORE_ADDR jmp_buf_pc
;
6305 struct bpstat_what what
;
6307 /* Handle cases caused by hitting a breakpoint. */
6309 frame
= get_current_frame ();
6310 gdbarch
= get_frame_arch (frame
);
6312 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6314 if (what
.call_dummy
)
6316 stop_stack_dummy
= what
.call_dummy
;
6319 /* A few breakpoint types have callbacks associated (e.g.,
6320 bp_jit_event). Run them now. */
6321 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6323 /* If we hit an internal event that triggers symbol changes, the
6324 current frame will be invalidated within bpstat_what (e.g., if we
6325 hit an internal solib event). Re-fetch it. */
6326 frame
= get_current_frame ();
6327 gdbarch
= get_frame_arch (frame
);
6329 switch (what
.main_action
)
6331 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6332 /* If we hit the breakpoint at longjmp while stepping, we
6333 install a momentary breakpoint at the target of the
6336 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6338 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6340 if (what
.is_longjmp
)
6342 struct value
*arg_value
;
6344 /* If we set the longjmp breakpoint via a SystemTap probe,
6345 then use it to extract the arguments. The destination PC
6346 is the third argument to the probe. */
6347 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6350 jmp_buf_pc
= value_as_address (arg_value
);
6351 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6353 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6354 || !gdbarch_get_longjmp_target (gdbarch
,
6355 frame
, &jmp_buf_pc
))
6357 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6358 "(!gdbarch_get_longjmp_target)");
6363 /* Insert a breakpoint at resume address. */
6364 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6367 check_exception_resume (ecs
, frame
);
6371 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6373 struct frame_info
*init_frame
;
6375 /* There are several cases to consider.
6377 1. The initiating frame no longer exists. In this case we
6378 must stop, because the exception or longjmp has gone too
6381 2. The initiating frame exists, and is the same as the
6382 current frame. We stop, because the exception or longjmp
6385 3. The initiating frame exists and is different from the
6386 current frame. This means the exception or longjmp has
6387 been caught beneath the initiating frame, so keep going.
6389 4. longjmp breakpoint has been placed just to protect
6390 against stale dummy frames and user is not interested in
6391 stopping around longjmps. */
6393 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6395 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6397 delete_exception_resume_breakpoint (ecs
->event_thread
);
6399 if (what
.is_longjmp
)
6401 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6403 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6411 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6415 struct frame_id current_id
6416 = get_frame_id (get_current_frame ());
6417 if (frame_id_eq (current_id
,
6418 ecs
->event_thread
->initiating_frame
))
6420 /* Case 2. Fall through. */
6430 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6432 delete_step_resume_breakpoint (ecs
->event_thread
);
6434 end_stepping_range (ecs
);
6438 case BPSTAT_WHAT_SINGLE
:
6439 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6440 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6441 /* Still need to check other stuff, at least the case where we
6442 are stepping and step out of the right range. */
6445 case BPSTAT_WHAT_STEP_RESUME
:
6446 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6448 delete_step_resume_breakpoint (ecs
->event_thread
);
6449 if (ecs
->event_thread
->control
.proceed_to_finish
6450 && execution_direction
== EXEC_REVERSE
)
6452 struct thread_info
*tp
= ecs
->event_thread
;
6454 /* We are finishing a function in reverse, and just hit the
6455 step-resume breakpoint at the start address of the
6456 function, and we're almost there -- just need to back up
6457 by one more single-step, which should take us back to the
6459 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6463 fill_in_stop_func (gdbarch
, ecs
);
6464 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6465 && execution_direction
== EXEC_REVERSE
)
6467 /* We are stepping over a function call in reverse, and just
6468 hit the step-resume breakpoint at the start address of
6469 the function. Go back to single-stepping, which should
6470 take us back to the function call. */
6471 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6477 case BPSTAT_WHAT_STOP_NOISY
:
6478 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6479 stop_print_frame
= true;
6481 /* Assume the thread stopped for a breakpoint. We'll still check
6482 whether a/the breakpoint is there when the thread is next
6484 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6489 case BPSTAT_WHAT_STOP_SILENT
:
6490 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6491 stop_print_frame
= false;
6493 /* Assume the thread stopped for a breakpoint. We'll still check
6494 whether a/the breakpoint is there when the thread is next
6496 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6500 case BPSTAT_WHAT_HP_STEP_RESUME
:
6501 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6503 delete_step_resume_breakpoint (ecs
->event_thread
);
6504 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6506 /* Back when the step-resume breakpoint was inserted, we
6507 were trying to single-step off a breakpoint. Go back to
6509 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6510 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6516 case BPSTAT_WHAT_KEEP_CHECKING
:
6520 /* If we stepped a permanent breakpoint and we had a high priority
6521 step-resume breakpoint for the address we stepped, but we didn't
6522 hit it, then we must have stepped into the signal handler. The
6523 step-resume was only necessary to catch the case of _not_
6524 stepping into the handler, so delete it, and fall through to
6525 checking whether the step finished. */
6526 if (ecs
->event_thread
->stepped_breakpoint
)
6528 struct breakpoint
*sr_bp
6529 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6532 && sr_bp
->loc
->permanent
6533 && sr_bp
->type
== bp_hp_step_resume
6534 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6536 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6537 delete_step_resume_breakpoint (ecs
->event_thread
);
6538 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6542 /* We come here if we hit a breakpoint but should not stop for it.
6543 Possibly we also were stepping and should stop for that. So fall
6544 through and test for stepping. But, if not stepping, do not
6547 /* In all-stop mode, if we're currently stepping but have stopped in
6548 some other thread, we need to switch back to the stepped thread. */
6549 if (switch_back_to_stepped_thread (ecs
))
6552 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6554 infrun_debug_printf ("step-resume breakpoint is inserted");
6556 /* Having a step-resume breakpoint overrides anything
6557 else having to do with stepping commands until
6558 that breakpoint is reached. */
6563 if (ecs
->event_thread
->control
.step_range_end
== 0)
6565 infrun_debug_printf ("no stepping, continue");
6566 /* Likewise if we aren't even stepping. */
6571 /* Re-fetch current thread's frame in case the code above caused
6572 the frame cache to be re-initialized, making our FRAME variable
6573 a dangling pointer. */
6574 frame
= get_current_frame ();
6575 gdbarch
= get_frame_arch (frame
);
6576 fill_in_stop_func (gdbarch
, ecs
);
6578 /* If stepping through a line, keep going if still within it.
6580 Note that step_range_end is the address of the first instruction
6581 beyond the step range, and NOT the address of the last instruction
6584 Note also that during reverse execution, we may be stepping
6585 through a function epilogue and therefore must detect when
6586 the current-frame changes in the middle of a line. */
6588 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6590 && (execution_direction
!= EXEC_REVERSE
6591 || frame_id_eq (get_frame_id (frame
),
6592 ecs
->event_thread
->control
.step_frame_id
)))
6595 ("stepping inside range [%s-%s]",
6596 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6597 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6599 /* Tentatively re-enable range stepping; `resume' disables it if
6600 necessary (e.g., if we're stepping over a breakpoint or we
6601 have software watchpoints). */
6602 ecs
->event_thread
->control
.may_range_step
= 1;
6604 /* When stepping backward, stop at beginning of line range
6605 (unless it's the function entry point, in which case
6606 keep going back to the call point). */
6607 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6608 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6609 && stop_pc
!= ecs
->stop_func_start
6610 && execution_direction
== EXEC_REVERSE
)
6611 end_stepping_range (ecs
);
6618 /* We stepped out of the stepping range. */
6620 /* If we are stepping at the source level and entered the runtime
6621 loader dynamic symbol resolution code...
6623 EXEC_FORWARD: we keep on single stepping until we exit the run
6624 time loader code and reach the callee's address.
6626 EXEC_REVERSE: we've already executed the callee (backward), and
6627 the runtime loader code is handled just like any other
6628 undebuggable function call. Now we need only keep stepping
6629 backward through the trampoline code, and that's handled further
6630 down, so there is nothing for us to do here. */
6632 if (execution_direction
!= EXEC_REVERSE
6633 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6634 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6636 CORE_ADDR pc_after_resolver
=
6637 gdbarch_skip_solib_resolver (gdbarch
,
6638 ecs
->event_thread
->suspend
.stop_pc
);
6640 infrun_debug_printf ("stepped into dynsym resolve code");
6642 if (pc_after_resolver
)
6644 /* Set up a step-resume breakpoint at the address
6645 indicated by SKIP_SOLIB_RESOLVER. */
6646 symtab_and_line sr_sal
;
6647 sr_sal
.pc
= pc_after_resolver
;
6648 sr_sal
.pspace
= get_frame_program_space (frame
);
6650 insert_step_resume_breakpoint_at_sal (gdbarch
,
6651 sr_sal
, null_frame_id
);
6658 /* Step through an indirect branch thunk. */
6659 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6660 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6661 ecs
->event_thread
->suspend
.stop_pc
))
6663 infrun_debug_printf ("stepped into indirect branch thunk");
6668 if (ecs
->event_thread
->control
.step_range_end
!= 1
6669 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6670 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6671 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6673 infrun_debug_printf ("stepped into signal trampoline");
6674 /* The inferior, while doing a "step" or "next", has ended up in
6675 a signal trampoline (either by a signal being delivered or by
6676 the signal handler returning). Just single-step until the
6677 inferior leaves the trampoline (either by calling the handler
6683 /* If we're in the return path from a shared library trampoline,
6684 we want to proceed through the trampoline when stepping. */
6685 /* macro/2012-04-25: This needs to come before the subroutine
6686 call check below as on some targets return trampolines look
6687 like subroutine calls (MIPS16 return thunks). */
6688 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6689 ecs
->event_thread
->suspend
.stop_pc
,
6690 ecs
->stop_func_name
)
6691 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6693 /* Determine where this trampoline returns. */
6694 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6695 CORE_ADDR real_stop_pc
6696 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6698 infrun_debug_printf ("stepped into solib return tramp");
6700 /* Only proceed through if we know where it's going. */
6703 /* And put the step-breakpoint there and go until there. */
6704 symtab_and_line sr_sal
;
6705 sr_sal
.pc
= real_stop_pc
;
6706 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6707 sr_sal
.pspace
= get_frame_program_space (frame
);
6709 /* Do not specify what the fp should be when we stop since
6710 on some machines the prologue is where the new fp value
6712 insert_step_resume_breakpoint_at_sal (gdbarch
,
6713 sr_sal
, null_frame_id
);
6715 /* Restart without fiddling with the step ranges or
6722 /* Check for subroutine calls. The check for the current frame
6723 equalling the step ID is not necessary - the check of the
6724 previous frame's ID is sufficient - but it is a common case and
6725 cheaper than checking the previous frame's ID.
6727 NOTE: frame_id_eq will never report two invalid frame IDs as
6728 being equal, so to get into this block, both the current and
6729 previous frame must have valid frame IDs. */
6730 /* The outer_frame_id check is a heuristic to detect stepping
6731 through startup code. If we step over an instruction which
6732 sets the stack pointer from an invalid value to a valid value,
6733 we may detect that as a subroutine call from the mythical
6734 "outermost" function. This could be fixed by marking
6735 outermost frames as !stack_p,code_p,special_p. Then the
6736 initial outermost frame, before sp was valid, would
6737 have code_addr == &_start. See the comment in frame_id_eq
6739 if (!frame_id_eq (get_stack_frame_id (frame
),
6740 ecs
->event_thread
->control
.step_stack_frame_id
)
6741 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6742 ecs
->event_thread
->control
.step_stack_frame_id
)
6743 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6745 || (ecs
->event_thread
->control
.step_start_function
6746 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6748 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6749 CORE_ADDR real_stop_pc
;
6751 infrun_debug_printf ("stepped into subroutine");
6753 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6755 /* I presume that step_over_calls is only 0 when we're
6756 supposed to be stepping at the assembly language level
6757 ("stepi"). Just stop. */
6758 /* And this works the same backward as frontward. MVS */
6759 end_stepping_range (ecs
);
6763 /* Reverse stepping through solib trampolines. */
6765 if (execution_direction
== EXEC_REVERSE
6766 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6767 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6768 || (ecs
->stop_func_start
== 0
6769 && in_solib_dynsym_resolve_code (stop_pc
))))
6771 /* Any solib trampoline code can be handled in reverse
6772 by simply continuing to single-step. We have already
6773 executed the solib function (backwards), and a few
6774 steps will take us back through the trampoline to the
6780 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6782 /* We're doing a "next".
6784 Normal (forward) execution: set a breakpoint at the
6785 callee's return address (the address at which the caller
6788 Reverse (backward) execution. set the step-resume
6789 breakpoint at the start of the function that we just
6790 stepped into (backwards), and continue to there. When we
6791 get there, we'll need to single-step back to the caller. */
6793 if (execution_direction
== EXEC_REVERSE
)
6795 /* If we're already at the start of the function, we've either
6796 just stepped backward into a single instruction function,
6797 or stepped back out of a signal handler to the first instruction
6798 of the function. Just keep going, which will single-step back
6800 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6802 /* Normal function call return (static or dynamic). */
6803 symtab_and_line sr_sal
;
6804 sr_sal
.pc
= ecs
->stop_func_start
;
6805 sr_sal
.pspace
= get_frame_program_space (frame
);
6806 insert_step_resume_breakpoint_at_sal (gdbarch
,
6807 sr_sal
, null_frame_id
);
6811 insert_step_resume_breakpoint_at_caller (frame
);
6817 /* If we are in a function call trampoline (a stub between the
6818 calling routine and the real function), locate the real
6819 function. That's what tells us (a) whether we want to step
6820 into it at all, and (b) what prologue we want to run to the
6821 end of, if we do step into it. */
6822 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6823 if (real_stop_pc
== 0)
6824 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6825 if (real_stop_pc
!= 0)
6826 ecs
->stop_func_start
= real_stop_pc
;
6828 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6830 symtab_and_line sr_sal
;
6831 sr_sal
.pc
= ecs
->stop_func_start
;
6832 sr_sal
.pspace
= get_frame_program_space (frame
);
6834 insert_step_resume_breakpoint_at_sal (gdbarch
,
6835 sr_sal
, null_frame_id
);
6840 /* If we have line number information for the function we are
6841 thinking of stepping into and the function isn't on the skip
6844 If there are several symtabs at that PC (e.g. with include
6845 files), just want to know whether *any* of them have line
6846 numbers. find_pc_line handles this. */
6848 struct symtab_and_line tmp_sal
;
6850 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6851 if (tmp_sal
.line
!= 0
6852 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6854 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6856 if (execution_direction
== EXEC_REVERSE
)
6857 handle_step_into_function_backward (gdbarch
, ecs
);
6859 handle_step_into_function (gdbarch
, ecs
);
6864 /* If we have no line number and the step-stop-if-no-debug is
6865 set, we stop the step so that the user has a chance to switch
6866 in assembly mode. */
6867 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6868 && step_stop_if_no_debug
)
6870 end_stepping_range (ecs
);
6874 if (execution_direction
== EXEC_REVERSE
)
6876 /* If we're already at the start of the function, we've either just
6877 stepped backward into a single instruction function without line
6878 number info, or stepped back out of a signal handler to the first
6879 instruction of the function without line number info. Just keep
6880 going, which will single-step back to the caller. */
6881 if (ecs
->stop_func_start
!= stop_pc
)
6883 /* Set a breakpoint at callee's start address.
6884 From there we can step once and be back in the caller. */
6885 symtab_and_line sr_sal
;
6886 sr_sal
.pc
= ecs
->stop_func_start
;
6887 sr_sal
.pspace
= get_frame_program_space (frame
);
6888 insert_step_resume_breakpoint_at_sal (gdbarch
,
6889 sr_sal
, null_frame_id
);
6893 /* Set a breakpoint at callee's return address (the address
6894 at which the caller will resume). */
6895 insert_step_resume_breakpoint_at_caller (frame
);
6901 /* Reverse stepping through solib trampolines. */
6903 if (execution_direction
== EXEC_REVERSE
6904 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6906 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6908 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6909 || (ecs
->stop_func_start
== 0
6910 && in_solib_dynsym_resolve_code (stop_pc
)))
6912 /* Any solib trampoline code can be handled in reverse
6913 by simply continuing to single-step. We have already
6914 executed the solib function (backwards), and a few
6915 steps will take us back through the trampoline to the
6920 else if (in_solib_dynsym_resolve_code (stop_pc
))
6922 /* Stepped backward into the solib dynsym resolver.
6923 Set a breakpoint at its start and continue, then
6924 one more step will take us out. */
6925 symtab_and_line sr_sal
;
6926 sr_sal
.pc
= ecs
->stop_func_start
;
6927 sr_sal
.pspace
= get_frame_program_space (frame
);
6928 insert_step_resume_breakpoint_at_sal (gdbarch
,
6929 sr_sal
, null_frame_id
);
6935 /* This always returns the sal for the inner-most frame when we are in a
6936 stack of inlined frames, even if GDB actually believes that it is in a
6937 more outer frame. This is checked for below by calls to
6938 inline_skipped_frames. */
6939 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6941 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6942 the trampoline processing logic, however, there are some trampolines
6943 that have no names, so we should do trampoline handling first. */
6944 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6945 && ecs
->stop_func_name
== NULL
6946 && stop_pc_sal
.line
== 0)
6948 infrun_debug_printf ("stepped into undebuggable function");
6950 /* The inferior just stepped into, or returned to, an
6951 undebuggable function (where there is no debugging information
6952 and no line number corresponding to the address where the
6953 inferior stopped). Since we want to skip this kind of code,
6954 we keep going until the inferior returns from this
6955 function - unless the user has asked us not to (via
6956 set step-mode) or we no longer know how to get back
6957 to the call site. */
6958 if (step_stop_if_no_debug
6959 || !frame_id_p (frame_unwind_caller_id (frame
)))
6961 /* If we have no line number and the step-stop-if-no-debug
6962 is set, we stop the step so that the user has a chance to
6963 switch in assembly mode. */
6964 end_stepping_range (ecs
);
6969 /* Set a breakpoint at callee's return address (the address
6970 at which the caller will resume). */
6971 insert_step_resume_breakpoint_at_caller (frame
);
6977 if (ecs
->event_thread
->control
.step_range_end
== 1)
6979 /* It is stepi or nexti. We always want to stop stepping after
6981 infrun_debug_printf ("stepi/nexti");
6982 end_stepping_range (ecs
);
6986 if (stop_pc_sal
.line
== 0)
6988 /* We have no line number information. That means to stop
6989 stepping (does this always happen right after one instruction,
6990 when we do "s" in a function with no line numbers,
6991 or can this happen as a result of a return or longjmp?). */
6992 infrun_debug_printf ("line number info");
6993 end_stepping_range (ecs
);
6997 /* Look for "calls" to inlined functions, part one. If the inline
6998 frame machinery detected some skipped call sites, we have entered
6999 a new inline function. */
7001 if (frame_id_eq (get_frame_id (get_current_frame ()),
7002 ecs
->event_thread
->control
.step_frame_id
)
7003 && inline_skipped_frames (ecs
->event_thread
))
7005 infrun_debug_printf ("stepped into inlined function");
7007 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7009 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7011 /* For "step", we're going to stop. But if the call site
7012 for this inlined function is on the same source line as
7013 we were previously stepping, go down into the function
7014 first. Otherwise stop at the call site. */
7016 if (call_sal
.line
== ecs
->event_thread
->current_line
7017 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7019 step_into_inline_frame (ecs
->event_thread
);
7020 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7027 end_stepping_range (ecs
);
7032 /* For "next", we should stop at the call site if it is on a
7033 different source line. Otherwise continue through the
7034 inlined function. */
7035 if (call_sal
.line
== ecs
->event_thread
->current_line
7036 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7039 end_stepping_range (ecs
);
7044 /* Look for "calls" to inlined functions, part two. If we are still
7045 in the same real function we were stepping through, but we have
7046 to go further up to find the exact frame ID, we are stepping
7047 through a more inlined call beyond its call site. */
7049 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7050 && !frame_id_eq (get_frame_id (get_current_frame ()),
7051 ecs
->event_thread
->control
.step_frame_id
)
7052 && stepped_in_from (get_current_frame (),
7053 ecs
->event_thread
->control
.step_frame_id
))
7055 infrun_debug_printf ("stepping through inlined function");
7057 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7058 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7061 end_stepping_range (ecs
);
7065 bool refresh_step_info
= true;
7066 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7067 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7068 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7070 if (stop_pc_sal
.is_stmt
)
7072 /* We are at the start of a different line. So stop. Note that
7073 we don't stop if we step into the middle of a different line.
7074 That is said to make things like for (;;) statements work
7076 infrun_debug_printf ("stepped to a different line");
7077 end_stepping_range (ecs
);
7080 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7081 ecs
->event_thread
->control
.step_frame_id
))
7083 /* We are at the start of a different line, however, this line is
7084 not marked as a statement, and we have not changed frame. We
7085 ignore this line table entry, and continue stepping forward,
7086 looking for a better place to stop. */
7087 refresh_step_info
= false;
7088 infrun_debug_printf ("stepped to a different line, but "
7089 "it's not the start of a statement");
7093 /* We aren't done stepping.
7095 Optimize by setting the stepping range to the line.
7096 (We might not be in the original line, but if we entered a
7097 new line in mid-statement, we continue stepping. This makes
7098 things like for(;;) statements work better.)
7100 If we entered a SAL that indicates a non-statement line table entry,
7101 then we update the stepping range, but we don't update the step info,
7102 which includes things like the line number we are stepping away from.
7103 This means we will stop when we find a line table entry that is marked
7104 as is-statement, even if it matches the non-statement one we just
7107 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7108 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7109 ecs
->event_thread
->control
.may_range_step
= 1;
7110 if (refresh_step_info
)
7111 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7113 infrun_debug_printf ("keep going");
7117 /* In all-stop mode, if we're currently stepping but have stopped in
7118 some other thread, we may need to switch back to the stepped
7119 thread. Returns true we set the inferior running, false if we left
7120 it stopped (and the event needs further processing). */
7123 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7125 if (!target_is_non_stop_p ())
7127 struct thread_info
*stepping_thread
;
7129 /* If any thread is blocked on some internal breakpoint, and we
7130 simply need to step over that breakpoint to get it going
7131 again, do that first. */
7133 /* However, if we see an event for the stepping thread, then we
7134 know all other threads have been moved past their breakpoints
7135 already. Let the caller check whether the step is finished,
7136 etc., before deciding to move it past a breakpoint. */
7137 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7140 /* Check if the current thread is blocked on an incomplete
7141 step-over, interrupted by a random signal. */
7142 if (ecs
->event_thread
->control
.trap_expected
7143 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7146 ("need to finish step-over of [%s]",
7147 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7152 /* Check if the current thread is blocked by a single-step
7153 breakpoint of another thread. */
7154 if (ecs
->hit_singlestep_breakpoint
)
7156 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7157 target_pid_to_str (ecs
->ptid
).c_str ());
7162 /* If this thread needs yet another step-over (e.g., stepping
7163 through a delay slot), do it first before moving on to
7165 if (thread_still_needs_step_over (ecs
->event_thread
))
7168 ("thread [%s] still needs step-over",
7169 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7174 /* If scheduler locking applies even if not stepping, there's no
7175 need to walk over threads. Above we've checked whether the
7176 current thread is stepping. If some other thread not the
7177 event thread is stepping, then it must be that scheduler
7178 locking is not in effect. */
7179 if (schedlock_applies (ecs
->event_thread
))
7182 /* Otherwise, we no longer expect a trap in the current thread.
7183 Clear the trap_expected flag before switching back -- this is
7184 what keep_going does as well, if we call it. */
7185 ecs
->event_thread
->control
.trap_expected
= 0;
7187 /* Likewise, clear the signal if it should not be passed. */
7188 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7189 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7191 /* Do all pending step-overs before actually proceeding with
7193 if (start_step_over ())
7195 prepare_to_wait (ecs
);
7199 /* Look for the stepping/nexting thread. */
7200 stepping_thread
= NULL
;
7202 for (thread_info
*tp
: all_non_exited_threads ())
7204 switch_to_thread_no_regs (tp
);
7206 /* Ignore threads of processes the caller is not
7209 && (tp
->inf
->process_target () != ecs
->target
7210 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7213 /* When stepping over a breakpoint, we lock all threads
7214 except the one that needs to move past the breakpoint.
7215 If a non-event thread has this set, the "incomplete
7216 step-over" check above should have caught it earlier. */
7217 if (tp
->control
.trap_expected
)
7219 internal_error (__FILE__
, __LINE__
,
7220 "[%s] has inconsistent state: "
7221 "trap_expected=%d\n",
7222 target_pid_to_str (tp
->ptid
).c_str (),
7223 tp
->control
.trap_expected
);
7226 /* Did we find the stepping thread? */
7227 if (tp
->control
.step_range_end
)
7229 /* Yep. There should only one though. */
7230 gdb_assert (stepping_thread
== NULL
);
7232 /* The event thread is handled at the top, before we
7234 gdb_assert (tp
!= ecs
->event_thread
);
7236 /* If some thread other than the event thread is
7237 stepping, then scheduler locking can't be in effect,
7238 otherwise we wouldn't have resumed the current event
7239 thread in the first place. */
7240 gdb_assert (!schedlock_applies (tp
));
7242 stepping_thread
= tp
;
7246 if (stepping_thread
!= NULL
)
7248 infrun_debug_printf ("switching back to stepped thread");
7250 if (keep_going_stepped_thread (stepping_thread
))
7252 prepare_to_wait (ecs
);
7257 switch_to_thread (ecs
->event_thread
);
7263 /* Set a previously stepped thread back to stepping. Returns true on
7264 success, false if the resume is not possible (e.g., the thread
7268 keep_going_stepped_thread (struct thread_info
*tp
)
7270 struct frame_info
*frame
;
7271 struct execution_control_state ecss
;
7272 struct execution_control_state
*ecs
= &ecss
;
7274 /* If the stepping thread exited, then don't try to switch back and
7275 resume it, which could fail in several different ways depending
7276 on the target. Instead, just keep going.
7278 We can find a stepping dead thread in the thread list in two
7281 - The target supports thread exit events, and when the target
7282 tries to delete the thread from the thread list, inferior_ptid
7283 pointed at the exiting thread. In such case, calling
7284 delete_thread does not really remove the thread from the list;
7285 instead, the thread is left listed, with 'exited' state.
7287 - The target's debug interface does not support thread exit
7288 events, and so we have no idea whatsoever if the previously
7289 stepping thread is still alive. For that reason, we need to
7290 synchronously query the target now. */
7292 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7294 infrun_debug_printf ("not resuming previously stepped thread, it has "
7301 infrun_debug_printf ("resuming previously stepped thread");
7303 reset_ecs (ecs
, tp
);
7304 switch_to_thread (tp
);
7306 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7307 frame
= get_current_frame ();
7309 /* If the PC of the thread we were trying to single-step has
7310 changed, then that thread has trapped or been signaled, but the
7311 event has not been reported to GDB yet. Re-poll the target
7312 looking for this particular thread's event (i.e. temporarily
7313 enable schedlock) by:
7315 - setting a break at the current PC
7316 - resuming that particular thread, only (by setting trap
7319 This prevents us continuously moving the single-step breakpoint
7320 forward, one instruction at a time, overstepping. */
7322 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7326 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7327 paddress (target_gdbarch (), tp
->prev_pc
),
7328 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7330 /* Clear the info of the previous step-over, as it's no longer
7331 valid (if the thread was trying to step over a breakpoint, it
7332 has already succeeded). It's what keep_going would do too,
7333 if we called it. Do this before trying to insert the sss
7334 breakpoint, otherwise if we were previously trying to step
7335 over this exact address in another thread, the breakpoint is
7337 clear_step_over_info ();
7338 tp
->control
.trap_expected
= 0;
7340 insert_single_step_breakpoint (get_frame_arch (frame
),
7341 get_frame_address_space (frame
),
7342 tp
->suspend
.stop_pc
);
7345 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7346 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7350 infrun_debug_printf ("expected thread still hasn't advanced");
7352 keep_going_pass_signal (ecs
);
7358 /* Is thread TP in the middle of (software or hardware)
7359 single-stepping? (Note the result of this function must never be
7360 passed directly as target_resume's STEP parameter.) */
7363 currently_stepping (struct thread_info
*tp
)
7365 return ((tp
->control
.step_range_end
7366 && tp
->control
.step_resume_breakpoint
== NULL
)
7367 || tp
->control
.trap_expected
7368 || tp
->stepped_breakpoint
7369 || bpstat_should_step ());
7372 /* Inferior has stepped into a subroutine call with source code that
7373 we should not step over. Do step to the first line of code in
7377 handle_step_into_function (struct gdbarch
*gdbarch
,
7378 struct execution_control_state
*ecs
)
7380 fill_in_stop_func (gdbarch
, ecs
);
7382 compunit_symtab
*cust
7383 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7384 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7385 ecs
->stop_func_start
7386 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7388 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7389 /* Use the step_resume_break to step until the end of the prologue,
7390 even if that involves jumps (as it seems to on the vax under
7392 /* If the prologue ends in the middle of a source line, continue to
7393 the end of that source line (if it is still within the function).
7394 Otherwise, just go to end of prologue. */
7395 if (stop_func_sal
.end
7396 && stop_func_sal
.pc
!= ecs
->stop_func_start
7397 && stop_func_sal
.end
< ecs
->stop_func_end
)
7398 ecs
->stop_func_start
= stop_func_sal
.end
;
7400 /* Architectures which require breakpoint adjustment might not be able
7401 to place a breakpoint at the computed address. If so, the test
7402 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7403 ecs->stop_func_start to an address at which a breakpoint may be
7404 legitimately placed.
7406 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7407 made, GDB will enter an infinite loop when stepping through
7408 optimized code consisting of VLIW instructions which contain
7409 subinstructions corresponding to different source lines. On
7410 FR-V, it's not permitted to place a breakpoint on any but the
7411 first subinstruction of a VLIW instruction. When a breakpoint is
7412 set, GDB will adjust the breakpoint address to the beginning of
7413 the VLIW instruction. Thus, we need to make the corresponding
7414 adjustment here when computing the stop address. */
7416 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7418 ecs
->stop_func_start
7419 = gdbarch_adjust_breakpoint_address (gdbarch
,
7420 ecs
->stop_func_start
);
7423 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7425 /* We are already there: stop now. */
7426 end_stepping_range (ecs
);
7431 /* Put the step-breakpoint there and go until there. */
7432 symtab_and_line sr_sal
;
7433 sr_sal
.pc
= ecs
->stop_func_start
;
7434 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7435 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7437 /* Do not specify what the fp should be when we stop since on
7438 some machines the prologue is where the new fp value is
7440 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7442 /* And make sure stepping stops right away then. */
7443 ecs
->event_thread
->control
.step_range_end
7444 = ecs
->event_thread
->control
.step_range_start
;
7449 /* Inferior has stepped backward into a subroutine call with source
7450 code that we should not step over. Do step to the beginning of the
7451 last line of code in it. */
7454 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7455 struct execution_control_state
*ecs
)
7457 struct compunit_symtab
*cust
;
7458 struct symtab_and_line stop_func_sal
;
7460 fill_in_stop_func (gdbarch
, ecs
);
7462 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7463 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7464 ecs
->stop_func_start
7465 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7467 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7469 /* OK, we're just going to keep stepping here. */
7470 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7472 /* We're there already. Just stop stepping now. */
7473 end_stepping_range (ecs
);
7477 /* Else just reset the step range and keep going.
7478 No step-resume breakpoint, they don't work for
7479 epilogues, which can have multiple entry paths. */
7480 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7481 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7487 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7488 This is used to both functions and to skip over code. */
7491 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7492 struct symtab_and_line sr_sal
,
7493 struct frame_id sr_id
,
7494 enum bptype sr_type
)
7496 /* There should never be more than one step-resume or longjmp-resume
7497 breakpoint per thread, so we should never be setting a new
7498 step_resume_breakpoint when one is already active. */
7499 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7500 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7502 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7503 paddress (gdbarch
, sr_sal
.pc
));
7505 inferior_thread ()->control
.step_resume_breakpoint
7506 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7510 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7511 struct symtab_and_line sr_sal
,
7512 struct frame_id sr_id
)
7514 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7519 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7520 This is used to skip a potential signal handler.
7522 This is called with the interrupted function's frame. The signal
7523 handler, when it returns, will resume the interrupted function at
7527 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7529 gdb_assert (return_frame
!= NULL
);
7531 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7533 symtab_and_line sr_sal
;
7534 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7535 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7536 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7538 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7539 get_stack_frame_id (return_frame
),
7543 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7544 is used to skip a function after stepping into it (for "next" or if
7545 the called function has no debugging information).
7547 The current function has almost always been reached by single
7548 stepping a call or return instruction. NEXT_FRAME belongs to the
7549 current function, and the breakpoint will be set at the caller's
7552 This is a separate function rather than reusing
7553 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7554 get_prev_frame, which may stop prematurely (see the implementation
7555 of frame_unwind_caller_id for an example). */
7558 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7560 /* We shouldn't have gotten here if we don't know where the call site
7562 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7564 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7566 symtab_and_line sr_sal
;
7567 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7568 frame_unwind_caller_pc (next_frame
));
7569 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7570 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7572 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7573 frame_unwind_caller_id (next_frame
));
7576 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7577 new breakpoint at the target of a jmp_buf. The handling of
7578 longjmp-resume uses the same mechanisms used for handling
7579 "step-resume" breakpoints. */
7582 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7584 /* There should never be more than one longjmp-resume breakpoint per
7585 thread, so we should never be setting a new
7586 longjmp_resume_breakpoint when one is already active. */
7587 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7589 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7590 paddress (gdbarch
, pc
));
7592 inferior_thread ()->control
.exception_resume_breakpoint
=
7593 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7596 /* Insert an exception resume breakpoint. TP is the thread throwing
7597 the exception. The block B is the block of the unwinder debug hook
7598 function. FRAME is the frame corresponding to the call to this
7599 function. SYM is the symbol of the function argument holding the
7600 target PC of the exception. */
7603 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7604 const struct block
*b
,
7605 struct frame_info
*frame
,
7610 struct block_symbol vsym
;
7611 struct value
*value
;
7613 struct breakpoint
*bp
;
7615 vsym
= lookup_symbol_search_name (sym
->search_name (),
7617 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7618 /* If the value was optimized out, revert to the old behavior. */
7619 if (! value_optimized_out (value
))
7621 handler
= value_as_address (value
);
7623 infrun_debug_printf ("exception resume at %lx",
7624 (unsigned long) handler
);
7626 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7628 bp_exception_resume
).release ();
7630 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7633 bp
->thread
= tp
->global_num
;
7634 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7637 catch (const gdb_exception_error
&e
)
7639 /* We want to ignore errors here. */
7643 /* A helper for check_exception_resume that sets an
7644 exception-breakpoint based on a SystemTap probe. */
7647 insert_exception_resume_from_probe (struct thread_info
*tp
,
7648 const struct bound_probe
*probe
,
7649 struct frame_info
*frame
)
7651 struct value
*arg_value
;
7653 struct breakpoint
*bp
;
7655 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7659 handler
= value_as_address (arg_value
);
7661 infrun_debug_printf ("exception resume at %s",
7662 paddress (probe
->objfile
->arch (), handler
));
7664 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7665 handler
, bp_exception_resume
).release ();
7666 bp
->thread
= tp
->global_num
;
7667 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7670 /* This is called when an exception has been intercepted. Check to
7671 see whether the exception's destination is of interest, and if so,
7672 set an exception resume breakpoint there. */
7675 check_exception_resume (struct execution_control_state
*ecs
,
7676 struct frame_info
*frame
)
7678 struct bound_probe probe
;
7679 struct symbol
*func
;
7681 /* First see if this exception unwinding breakpoint was set via a
7682 SystemTap probe point. If so, the probe has two arguments: the
7683 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7684 set a breakpoint there. */
7685 probe
= find_probe_by_pc (get_frame_pc (frame
));
7688 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7692 func
= get_frame_function (frame
);
7698 const struct block
*b
;
7699 struct block_iterator iter
;
7703 /* The exception breakpoint is a thread-specific breakpoint on
7704 the unwinder's debug hook, declared as:
7706 void _Unwind_DebugHook (void *cfa, void *handler);
7708 The CFA argument indicates the frame to which control is
7709 about to be transferred. HANDLER is the destination PC.
7711 We ignore the CFA and set a temporary breakpoint at HANDLER.
7712 This is not extremely efficient but it avoids issues in gdb
7713 with computing the DWARF CFA, and it also works even in weird
7714 cases such as throwing an exception from inside a signal
7717 b
= SYMBOL_BLOCK_VALUE (func
);
7718 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7720 if (!SYMBOL_IS_ARGUMENT (sym
))
7727 insert_exception_resume_breakpoint (ecs
->event_thread
,
7733 catch (const gdb_exception_error
&e
)
7739 stop_waiting (struct execution_control_state
*ecs
)
7741 infrun_debug_printf ("stop_waiting");
7743 /* Let callers know we don't want to wait for the inferior anymore. */
7744 ecs
->wait_some_more
= 0;
7746 /* If all-stop, but there exists a non-stop target, stop all
7747 threads now that we're presenting the stop to the user. */
7748 if (!non_stop
&& exists_non_stop_target ())
7749 stop_all_threads ();
7752 /* Like keep_going, but passes the signal to the inferior, even if the
7753 signal is set to nopass. */
7756 keep_going_pass_signal (struct execution_control_state
*ecs
)
7758 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7759 gdb_assert (!ecs
->event_thread
->resumed
);
7761 /* Save the pc before execution, to compare with pc after stop. */
7762 ecs
->event_thread
->prev_pc
7763 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7765 if (ecs
->event_thread
->control
.trap_expected
)
7767 struct thread_info
*tp
= ecs
->event_thread
;
7769 infrun_debug_printf ("%s has trap_expected set, "
7770 "resuming to collect trap",
7771 target_pid_to_str (tp
->ptid
).c_str ());
7773 /* We haven't yet gotten our trap, and either: intercepted a
7774 non-signal event (e.g., a fork); or took a signal which we
7775 are supposed to pass through to the inferior. Simply
7777 resume (ecs
->event_thread
->suspend
.stop_signal
);
7779 else if (step_over_info_valid_p ())
7781 /* Another thread is stepping over a breakpoint in-line. If
7782 this thread needs a step-over too, queue the request. In
7783 either case, this resume must be deferred for later. */
7784 struct thread_info
*tp
= ecs
->event_thread
;
7786 if (ecs
->hit_singlestep_breakpoint
7787 || thread_still_needs_step_over (tp
))
7789 infrun_debug_printf ("step-over already in progress: "
7790 "step-over for %s deferred",
7791 target_pid_to_str (tp
->ptid
).c_str ());
7792 global_thread_step_over_chain_enqueue (tp
);
7796 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7797 target_pid_to_str (tp
->ptid
).c_str ());
7802 struct regcache
*regcache
= get_current_regcache ();
7805 step_over_what step_what
;
7807 /* Either the trap was not expected, but we are continuing
7808 anyway (if we got a signal, the user asked it be passed to
7811 We got our expected trap, but decided we should resume from
7814 We're going to run this baby now!
7816 Note that insert_breakpoints won't try to re-insert
7817 already inserted breakpoints. Therefore, we don't
7818 care if breakpoints were already inserted, or not. */
7820 /* If we need to step over a breakpoint, and we're not using
7821 displaced stepping to do so, insert all breakpoints
7822 (watchpoints, etc.) but the one we're stepping over, step one
7823 instruction, and then re-insert the breakpoint when that step
7826 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7828 remove_bp
= (ecs
->hit_singlestep_breakpoint
7829 || (step_what
& STEP_OVER_BREAKPOINT
));
7830 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7832 /* We can't use displaced stepping if we need to step past a
7833 watchpoint. The instruction copied to the scratch pad would
7834 still trigger the watchpoint. */
7836 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7838 set_step_over_info (regcache
->aspace (),
7839 regcache_read_pc (regcache
), remove_wps
,
7840 ecs
->event_thread
->global_num
);
7842 else if (remove_wps
)
7843 set_step_over_info (NULL
, 0, remove_wps
, -1);
7845 /* If we now need to do an in-line step-over, we need to stop
7846 all other threads. Note this must be done before
7847 insert_breakpoints below, because that removes the breakpoint
7848 we're about to step over, otherwise other threads could miss
7850 if (step_over_info_valid_p () && target_is_non_stop_p ())
7851 stop_all_threads ();
7853 /* Stop stepping if inserting breakpoints fails. */
7856 insert_breakpoints ();
7858 catch (const gdb_exception_error
&e
)
7860 exception_print (gdb_stderr
, e
);
7862 clear_step_over_info ();
7866 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7868 resume (ecs
->event_thread
->suspend
.stop_signal
);
7871 prepare_to_wait (ecs
);
7874 /* Called when we should continue running the inferior, because the
7875 current event doesn't cause a user visible stop. This does the
7876 resuming part; waiting for the next event is done elsewhere. */
7879 keep_going (struct execution_control_state
*ecs
)
7881 if (ecs
->event_thread
->control
.trap_expected
7882 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7883 ecs
->event_thread
->control
.trap_expected
= 0;
7885 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7886 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7887 keep_going_pass_signal (ecs
);
7890 /* This function normally comes after a resume, before
7891 handle_inferior_event exits. It takes care of any last bits of
7892 housekeeping, and sets the all-important wait_some_more flag. */
7895 prepare_to_wait (struct execution_control_state
*ecs
)
7897 infrun_debug_printf ("prepare_to_wait");
7899 ecs
->wait_some_more
= 1;
7901 /* If the target can't async, emulate it by marking the infrun event
7902 handler such that as soon as we get back to the event-loop, we
7903 immediately end up in fetch_inferior_event again calling
7905 if (!target_can_async_p ())
7906 mark_infrun_async_event_handler ();
7909 /* We are done with the step range of a step/next/si/ni command.
7910 Called once for each n of a "step n" operation. */
7913 end_stepping_range (struct execution_control_state
*ecs
)
7915 ecs
->event_thread
->control
.stop_step
= 1;
7919 /* Several print_*_reason functions to print why the inferior has stopped.
7920 We always print something when the inferior exits, or receives a signal.
7921 The rest of the cases are dealt with later on in normal_stop and
7922 print_it_typical. Ideally there should be a call to one of these
7923 print_*_reason functions functions from handle_inferior_event each time
7924 stop_waiting is called.
7926 Note that we don't call these directly, instead we delegate that to
7927 the interpreters, through observers. Interpreters then call these
7928 with whatever uiout is right. */
7931 print_end_stepping_range_reason (struct ui_out
*uiout
)
7933 /* For CLI-like interpreters, print nothing. */
7935 if (uiout
->is_mi_like_p ())
7937 uiout
->field_string ("reason",
7938 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7943 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7945 annotate_signalled ();
7946 if (uiout
->is_mi_like_p ())
7948 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7949 uiout
->text ("\nProgram terminated with signal ");
7950 annotate_signal_name ();
7951 uiout
->field_string ("signal-name",
7952 gdb_signal_to_name (siggnal
));
7953 annotate_signal_name_end ();
7955 annotate_signal_string ();
7956 uiout
->field_string ("signal-meaning",
7957 gdb_signal_to_string (siggnal
));
7958 annotate_signal_string_end ();
7959 uiout
->text (".\n");
7960 uiout
->text ("The program no longer exists.\n");
7964 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7966 struct inferior
*inf
= current_inferior ();
7967 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7969 annotate_exited (exitstatus
);
7972 if (uiout
->is_mi_like_p ())
7973 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7974 std::string exit_code_str
7975 = string_printf ("0%o", (unsigned int) exitstatus
);
7976 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7977 plongest (inf
->num
), pidstr
.c_str (),
7978 string_field ("exit-code", exit_code_str
.c_str ()));
7982 if (uiout
->is_mi_like_p ())
7984 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7985 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7986 plongest (inf
->num
), pidstr
.c_str ());
7991 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7993 struct thread_info
*thr
= inferior_thread ();
7997 if (uiout
->is_mi_like_p ())
7999 else if (show_thread_that_caused_stop ())
8003 uiout
->text ("\nThread ");
8004 uiout
->field_string ("thread-id", print_thread_id (thr
));
8006 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8009 uiout
->text (" \"");
8010 uiout
->field_string ("name", name
);
8015 uiout
->text ("\nProgram");
8017 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8018 uiout
->text (" stopped");
8021 uiout
->text (" received signal ");
8022 annotate_signal_name ();
8023 if (uiout
->is_mi_like_p ())
8025 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8026 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8027 annotate_signal_name_end ();
8029 annotate_signal_string ();
8030 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8032 struct regcache
*regcache
= get_current_regcache ();
8033 struct gdbarch
*gdbarch
= regcache
->arch ();
8034 if (gdbarch_report_signal_info_p (gdbarch
))
8035 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8037 annotate_signal_string_end ();
8039 uiout
->text (".\n");
8043 print_no_history_reason (struct ui_out
*uiout
)
8045 uiout
->text ("\nNo more reverse-execution history.\n");
8048 /* Print current location without a level number, if we have changed
8049 functions or hit a breakpoint. Print source line if we have one.
8050 bpstat_print contains the logic deciding in detail what to print,
8051 based on the event(s) that just occurred. */
8054 print_stop_location (struct target_waitstatus
*ws
)
8057 enum print_what source_flag
;
8058 int do_frame_printing
= 1;
8059 struct thread_info
*tp
= inferior_thread ();
8061 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8065 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8066 should) carry around the function and does (or should) use
8067 that when doing a frame comparison. */
8068 if (tp
->control
.stop_step
8069 && frame_id_eq (tp
->control
.step_frame_id
,
8070 get_frame_id (get_current_frame ()))
8071 && (tp
->control
.step_start_function
8072 == find_pc_function (tp
->suspend
.stop_pc
)))
8074 /* Finished step, just print source line. */
8075 source_flag
= SRC_LINE
;
8079 /* Print location and source line. */
8080 source_flag
= SRC_AND_LOC
;
8083 case PRINT_SRC_AND_LOC
:
8084 /* Print location and source line. */
8085 source_flag
= SRC_AND_LOC
;
8087 case PRINT_SRC_ONLY
:
8088 source_flag
= SRC_LINE
;
8091 /* Something bogus. */
8092 source_flag
= SRC_LINE
;
8093 do_frame_printing
= 0;
8096 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8099 /* The behavior of this routine with respect to the source
8101 SRC_LINE: Print only source line
8102 LOCATION: Print only location
8103 SRC_AND_LOC: Print location and source line. */
8104 if (do_frame_printing
)
8105 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8111 print_stop_event (struct ui_out
*uiout
, bool displays
)
8113 struct target_waitstatus last
;
8114 struct thread_info
*tp
;
8116 get_last_target_status (nullptr, nullptr, &last
);
8119 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8121 print_stop_location (&last
);
8123 /* Display the auto-display expressions. */
8128 tp
= inferior_thread ();
8129 if (tp
->thread_fsm
!= NULL
8130 && tp
->thread_fsm
->finished_p ())
8132 struct return_value_info
*rv
;
8134 rv
= tp
->thread_fsm
->return_value ();
8136 print_return_value (uiout
, rv
);
8143 maybe_remove_breakpoints (void)
8145 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8147 if (remove_breakpoints ())
8149 target_terminal::ours_for_output ();
8150 printf_filtered (_("Cannot remove breakpoints because "
8151 "program is no longer writable.\nFurther "
8152 "execution is probably impossible.\n"));
8157 /* The execution context that just caused a normal stop. */
8164 DISABLE_COPY_AND_ASSIGN (stop_context
);
8166 bool changed () const;
8171 /* The event PTID. */
8175 /* If stopp for a thread event, this is the thread that caused the
8177 struct thread_info
*thread
;
8179 /* The inferior that caused the stop. */
8183 /* Initializes a new stop context. If stopped for a thread event, this
8184 takes a strong reference to the thread. */
8186 stop_context::stop_context ()
8188 stop_id
= get_stop_id ();
8189 ptid
= inferior_ptid
;
8190 inf_num
= current_inferior ()->num
;
8192 if (inferior_ptid
!= null_ptid
)
8194 /* Take a strong reference so that the thread can't be deleted
8196 thread
= inferior_thread ();
8203 /* Release a stop context previously created with save_stop_context.
8204 Releases the strong reference to the thread as well. */
8206 stop_context::~stop_context ()
8212 /* Return true if the current context no longer matches the saved stop
8216 stop_context::changed () const
8218 if (ptid
!= inferior_ptid
)
8220 if (inf_num
!= current_inferior ()->num
)
8222 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8224 if (get_stop_id () != stop_id
)
8234 struct target_waitstatus last
;
8236 get_last_target_status (nullptr, nullptr, &last
);
8240 /* If an exception is thrown from this point on, make sure to
8241 propagate GDB's knowledge of the executing state to the
8242 frontend/user running state. A QUIT is an easy exception to see
8243 here, so do this before any filtered output. */
8245 ptid_t finish_ptid
= null_ptid
;
8248 finish_ptid
= minus_one_ptid
;
8249 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8250 || last
.kind
== TARGET_WAITKIND_EXITED
)
8252 /* On some targets, we may still have live threads in the
8253 inferior when we get a process exit event. E.g., for
8254 "checkpoint", when the current checkpoint/fork exits,
8255 linux-fork.c automatically switches to another fork from
8256 within target_mourn_inferior. */
8257 if (inferior_ptid
!= null_ptid
)
8258 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8260 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8261 finish_ptid
= inferior_ptid
;
8263 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8264 if (finish_ptid
!= null_ptid
)
8266 maybe_finish_thread_state
.emplace
8267 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8270 /* As we're presenting a stop, and potentially removing breakpoints,
8271 update the thread list so we can tell whether there are threads
8272 running on the target. With target remote, for example, we can
8273 only learn about new threads when we explicitly update the thread
8274 list. Do this before notifying the interpreters about signal
8275 stops, end of stepping ranges, etc., so that the "new thread"
8276 output is emitted before e.g., "Program received signal FOO",
8277 instead of after. */
8278 update_thread_list ();
8280 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8281 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8283 /* As with the notification of thread events, we want to delay
8284 notifying the user that we've switched thread context until
8285 the inferior actually stops.
8287 There's no point in saying anything if the inferior has exited.
8288 Note that SIGNALLED here means "exited with a signal", not
8289 "received a signal".
8291 Also skip saying anything in non-stop mode. In that mode, as we
8292 don't want GDB to switch threads behind the user's back, to avoid
8293 races where the user is typing a command to apply to thread x,
8294 but GDB switches to thread y before the user finishes entering
8295 the command, fetch_inferior_event installs a cleanup to restore
8296 the current thread back to the thread the user had selected right
8297 after this event is handled, so we're not really switching, only
8298 informing of a stop. */
8300 && previous_inferior_ptid
!= inferior_ptid
8301 && target_has_execution ()
8302 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8303 && last
.kind
!= TARGET_WAITKIND_EXITED
8304 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8306 SWITCH_THRU_ALL_UIS ()
8308 target_terminal::ours_for_output ();
8309 printf_filtered (_("[Switching to %s]\n"),
8310 target_pid_to_str (inferior_ptid
).c_str ());
8311 annotate_thread_changed ();
8313 previous_inferior_ptid
= inferior_ptid
;
8316 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8318 SWITCH_THRU_ALL_UIS ()
8319 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8321 target_terminal::ours_for_output ();
8322 printf_filtered (_("No unwaited-for children left.\n"));
8326 /* Note: this depends on the update_thread_list call above. */
8327 maybe_remove_breakpoints ();
8329 /* If an auto-display called a function and that got a signal,
8330 delete that auto-display to avoid an infinite recursion. */
8332 if (stopped_by_random_signal
)
8333 disable_current_display ();
8335 SWITCH_THRU_ALL_UIS ()
8337 async_enable_stdin ();
8340 /* Let the user/frontend see the threads as stopped. */
8341 maybe_finish_thread_state
.reset ();
8343 /* Select innermost stack frame - i.e., current frame is frame 0,
8344 and current location is based on that. Handle the case where the
8345 dummy call is returning after being stopped. E.g. the dummy call
8346 previously hit a breakpoint. (If the dummy call returns
8347 normally, we won't reach here.) Do this before the stop hook is
8348 run, so that it doesn't get to see the temporary dummy frame,
8349 which is not where we'll present the stop. */
8350 if (has_stack_frames ())
8352 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8354 /* Pop the empty frame that contains the stack dummy. This
8355 also restores inferior state prior to the call (struct
8356 infcall_suspend_state). */
8357 struct frame_info
*frame
= get_current_frame ();
8359 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8361 /* frame_pop calls reinit_frame_cache as the last thing it
8362 does which means there's now no selected frame. */
8365 select_frame (get_current_frame ());
8367 /* Set the current source location. */
8368 set_current_sal_from_frame (get_current_frame ());
8371 /* Look up the hook_stop and run it (CLI internally handles problem
8372 of stop_command's pre-hook not existing). */
8373 if (stop_command
!= NULL
)
8375 stop_context saved_context
;
8379 execute_cmd_pre_hook (stop_command
);
8381 catch (const gdb_exception
&ex
)
8383 exception_fprintf (gdb_stderr
, ex
,
8384 "Error while running hook_stop:\n");
8387 /* If the stop hook resumes the target, then there's no point in
8388 trying to notify about the previous stop; its context is
8389 gone. Likewise if the command switches thread or inferior --
8390 the observers would print a stop for the wrong
8392 if (saved_context
.changed ())
8396 /* Notify observers about the stop. This is where the interpreters
8397 print the stop event. */
8398 if (inferior_ptid
!= null_ptid
)
8399 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8402 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8404 annotate_stopped ();
8406 if (target_has_execution ())
8408 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8409 && last
.kind
!= TARGET_WAITKIND_EXITED
8410 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8411 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8412 Delete any breakpoint that is to be deleted at the next stop. */
8413 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8416 /* Try to get rid of automatically added inferiors that are no
8417 longer needed. Keeping those around slows down things linearly.
8418 Note that this never removes the current inferior. */
8425 signal_stop_state (int signo
)
8427 return signal_stop
[signo
];
8431 signal_print_state (int signo
)
8433 return signal_print
[signo
];
8437 signal_pass_state (int signo
)
8439 return signal_program
[signo
];
8443 signal_cache_update (int signo
)
8447 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8448 signal_cache_update (signo
);
8453 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8454 && signal_print
[signo
] == 0
8455 && signal_program
[signo
] == 1
8456 && signal_catch
[signo
] == 0);
8460 signal_stop_update (int signo
, int state
)
8462 int ret
= signal_stop
[signo
];
8464 signal_stop
[signo
] = state
;
8465 signal_cache_update (signo
);
8470 signal_print_update (int signo
, int state
)
8472 int ret
= signal_print
[signo
];
8474 signal_print
[signo
] = state
;
8475 signal_cache_update (signo
);
8480 signal_pass_update (int signo
, int state
)
8482 int ret
= signal_program
[signo
];
8484 signal_program
[signo
] = state
;
8485 signal_cache_update (signo
);
8489 /* Update the global 'signal_catch' from INFO and notify the
8493 signal_catch_update (const unsigned int *info
)
8497 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8498 signal_catch
[i
] = info
[i
] > 0;
8499 signal_cache_update (-1);
8500 target_pass_signals (signal_pass
);
8504 sig_print_header (void)
8506 printf_filtered (_("Signal Stop\tPrint\tPass "
8507 "to program\tDescription\n"));
8511 sig_print_info (enum gdb_signal oursig
)
8513 const char *name
= gdb_signal_to_name (oursig
);
8514 int name_padding
= 13 - strlen (name
);
8516 if (name_padding
<= 0)
8519 printf_filtered ("%s", name
);
8520 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8521 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8522 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8523 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8524 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8527 /* Specify how various signals in the inferior should be handled. */
8530 handle_command (const char *args
, int from_tty
)
8532 int digits
, wordlen
;
8533 int sigfirst
, siglast
;
8534 enum gdb_signal oursig
;
8539 error_no_arg (_("signal to handle"));
8542 /* Allocate and zero an array of flags for which signals to handle. */
8544 const size_t nsigs
= GDB_SIGNAL_LAST
;
8545 unsigned char sigs
[nsigs
] {};
8547 /* Break the command line up into args. */
8549 gdb_argv
built_argv (args
);
8551 /* Walk through the args, looking for signal oursigs, signal names, and
8552 actions. Signal numbers and signal names may be interspersed with
8553 actions, with the actions being performed for all signals cumulatively
8554 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8556 for (char *arg
: built_argv
)
8558 wordlen
= strlen (arg
);
8559 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8563 sigfirst
= siglast
= -1;
8565 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8567 /* Apply action to all signals except those used by the
8568 debugger. Silently skip those. */
8571 siglast
= nsigs
- 1;
8573 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8575 SET_SIGS (nsigs
, sigs
, signal_stop
);
8576 SET_SIGS (nsigs
, sigs
, signal_print
);
8578 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8580 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8582 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8584 SET_SIGS (nsigs
, sigs
, signal_print
);
8586 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8588 SET_SIGS (nsigs
, sigs
, signal_program
);
8590 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8592 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8594 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8596 SET_SIGS (nsigs
, sigs
, signal_program
);
8598 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8600 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8601 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8603 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8605 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8607 else if (digits
> 0)
8609 /* It is numeric. The numeric signal refers to our own
8610 internal signal numbering from target.h, not to host/target
8611 signal number. This is a feature; users really should be
8612 using symbolic names anyway, and the common ones like
8613 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8615 sigfirst
= siglast
= (int)
8616 gdb_signal_from_command (atoi (arg
));
8617 if (arg
[digits
] == '-')
8620 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8622 if (sigfirst
> siglast
)
8624 /* Bet he didn't figure we'd think of this case... */
8625 std::swap (sigfirst
, siglast
);
8630 oursig
= gdb_signal_from_name (arg
);
8631 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8633 sigfirst
= siglast
= (int) oursig
;
8637 /* Not a number and not a recognized flag word => complain. */
8638 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8642 /* If any signal numbers or symbol names were found, set flags for
8643 which signals to apply actions to. */
8645 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8647 switch ((enum gdb_signal
) signum
)
8649 case GDB_SIGNAL_TRAP
:
8650 case GDB_SIGNAL_INT
:
8651 if (!allsigs
&& !sigs
[signum
])
8653 if (query (_("%s is used by the debugger.\n\
8654 Are you sure you want to change it? "),
8655 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8660 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8664 case GDB_SIGNAL_DEFAULT
:
8665 case GDB_SIGNAL_UNKNOWN
:
8666 /* Make sure that "all" doesn't print these. */
8675 for (int signum
= 0; signum
< nsigs
; signum
++)
8678 signal_cache_update (-1);
8679 target_pass_signals (signal_pass
);
8680 target_program_signals (signal_program
);
8684 /* Show the results. */
8685 sig_print_header ();
8686 for (; signum
< nsigs
; signum
++)
8688 sig_print_info ((enum gdb_signal
) signum
);
8695 /* Complete the "handle" command. */
8698 handle_completer (struct cmd_list_element
*ignore
,
8699 completion_tracker
&tracker
,
8700 const char *text
, const char *word
)
8702 static const char * const keywords
[] =
8716 signal_completer (ignore
, tracker
, text
, word
);
8717 complete_on_enum (tracker
, keywords
, word
, word
);
8721 gdb_signal_from_command (int num
)
8723 if (num
>= 1 && num
<= 15)
8724 return (enum gdb_signal
) num
;
8725 error (_("Only signals 1-15 are valid as numeric signals.\n\
8726 Use \"info signals\" for a list of symbolic signals."));
8729 /* Print current contents of the tables set by the handle command.
8730 It is possible we should just be printing signals actually used
8731 by the current target (but for things to work right when switching
8732 targets, all signals should be in the signal tables). */
8735 info_signals_command (const char *signum_exp
, int from_tty
)
8737 enum gdb_signal oursig
;
8739 sig_print_header ();
8743 /* First see if this is a symbol name. */
8744 oursig
= gdb_signal_from_name (signum_exp
);
8745 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8747 /* No, try numeric. */
8749 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8751 sig_print_info (oursig
);
8755 printf_filtered ("\n");
8756 /* These ugly casts brought to you by the native VAX compiler. */
8757 for (oursig
= GDB_SIGNAL_FIRST
;
8758 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8759 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8763 if (oursig
!= GDB_SIGNAL_UNKNOWN
8764 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8765 sig_print_info (oursig
);
8768 printf_filtered (_("\nUse the \"handle\" command "
8769 "to change these tables.\n"));
8772 /* The $_siginfo convenience variable is a bit special. We don't know
8773 for sure the type of the value until we actually have a chance to
8774 fetch the data. The type can change depending on gdbarch, so it is
8775 also dependent on which thread you have selected.
8777 1. making $_siginfo be an internalvar that creates a new value on
8780 2. making the value of $_siginfo be an lval_computed value. */
8782 /* This function implements the lval_computed support for reading a
8786 siginfo_value_read (struct value
*v
)
8788 LONGEST transferred
;
8790 /* If we can access registers, so can we access $_siginfo. Likewise
8792 validate_registers_access ();
8795 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8797 value_contents_all_raw (v
),
8799 TYPE_LENGTH (value_type (v
)));
8801 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8802 error (_("Unable to read siginfo"));
8805 /* This function implements the lval_computed support for writing a
8809 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8811 LONGEST transferred
;
8813 /* If we can access registers, so can we access $_siginfo. Likewise
8815 validate_registers_access ();
8817 transferred
= target_write (current_top_target (),
8818 TARGET_OBJECT_SIGNAL_INFO
,
8820 value_contents_all_raw (fromval
),
8822 TYPE_LENGTH (value_type (fromval
)));
8824 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8825 error (_("Unable to write siginfo"));
8828 static const struct lval_funcs siginfo_value_funcs
=
8834 /* Return a new value with the correct type for the siginfo object of
8835 the current thread using architecture GDBARCH. Return a void value
8836 if there's no object available. */
8838 static struct value
*
8839 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8842 if (target_has_stack ()
8843 && inferior_ptid
!= null_ptid
8844 && gdbarch_get_siginfo_type_p (gdbarch
))
8846 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8848 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8851 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8855 /* infcall_suspend_state contains state about the program itself like its
8856 registers and any signal it received when it last stopped.
8857 This state must be restored regardless of how the inferior function call
8858 ends (either successfully, or after it hits a breakpoint or signal)
8859 if the program is to properly continue where it left off. */
8861 class infcall_suspend_state
8864 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8865 once the inferior function call has finished. */
8866 infcall_suspend_state (struct gdbarch
*gdbarch
,
8867 const struct thread_info
*tp
,
8868 struct regcache
*regcache
)
8869 : m_thread_suspend (tp
->suspend
),
8870 m_registers (new readonly_detached_regcache (*regcache
))
8872 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8874 if (gdbarch_get_siginfo_type_p (gdbarch
))
8876 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8877 size_t len
= TYPE_LENGTH (type
);
8879 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8881 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8882 siginfo_data
.get (), 0, len
) != len
)
8884 /* Errors ignored. */
8885 siginfo_data
.reset (nullptr);
8891 m_siginfo_gdbarch
= gdbarch
;
8892 m_siginfo_data
= std::move (siginfo_data
);
8896 /* Return a pointer to the stored register state. */
8898 readonly_detached_regcache
*registers () const
8900 return m_registers
.get ();
8903 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8905 void restore (struct gdbarch
*gdbarch
,
8906 struct thread_info
*tp
,
8907 struct regcache
*regcache
) const
8909 tp
->suspend
= m_thread_suspend
;
8911 if (m_siginfo_gdbarch
== gdbarch
)
8913 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8915 /* Errors ignored. */
8916 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8917 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8920 /* The inferior can be gone if the user types "print exit(0)"
8921 (and perhaps other times). */
8922 if (target_has_execution ())
8923 /* NB: The register write goes through to the target. */
8924 regcache
->restore (registers ());
8928 /* How the current thread stopped before the inferior function call was
8930 struct thread_suspend_state m_thread_suspend
;
8932 /* The registers before the inferior function call was executed. */
8933 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8935 /* Format of SIGINFO_DATA or NULL if it is not present. */
8936 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8938 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8939 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8940 content would be invalid. */
8941 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8944 infcall_suspend_state_up
8945 save_infcall_suspend_state ()
8947 struct thread_info
*tp
= inferior_thread ();
8948 struct regcache
*regcache
= get_current_regcache ();
8949 struct gdbarch
*gdbarch
= regcache
->arch ();
8951 infcall_suspend_state_up inf_state
8952 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8954 /* Having saved the current state, adjust the thread state, discarding
8955 any stop signal information. The stop signal is not useful when
8956 starting an inferior function call, and run_inferior_call will not use
8957 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8958 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8963 /* Restore inferior session state to INF_STATE. */
8966 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8968 struct thread_info
*tp
= inferior_thread ();
8969 struct regcache
*regcache
= get_current_regcache ();
8970 struct gdbarch
*gdbarch
= regcache
->arch ();
8972 inf_state
->restore (gdbarch
, tp
, regcache
);
8973 discard_infcall_suspend_state (inf_state
);
8977 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8982 readonly_detached_regcache
*
8983 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8985 return inf_state
->registers ();
8988 /* infcall_control_state contains state regarding gdb's control of the
8989 inferior itself like stepping control. It also contains session state like
8990 the user's currently selected frame. */
8992 struct infcall_control_state
8994 struct thread_control_state thread_control
;
8995 struct inferior_control_state inferior_control
;
8998 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8999 int stopped_by_random_signal
= 0;
9001 /* ID and level of the selected frame when the inferior function
9003 struct frame_id selected_frame_id
{};
9004 int selected_frame_level
= -1;
9007 /* Save all of the information associated with the inferior<==>gdb
9010 infcall_control_state_up
9011 save_infcall_control_state ()
9013 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9014 struct thread_info
*tp
= inferior_thread ();
9015 struct inferior
*inf
= current_inferior ();
9017 inf_status
->thread_control
= tp
->control
;
9018 inf_status
->inferior_control
= inf
->control
;
9020 tp
->control
.step_resume_breakpoint
= NULL
;
9021 tp
->control
.exception_resume_breakpoint
= NULL
;
9023 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9024 chain. If caller's caller is walking the chain, they'll be happier if we
9025 hand them back the original chain when restore_infcall_control_state is
9027 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9030 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9031 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9033 save_selected_frame (&inf_status
->selected_frame_id
,
9034 &inf_status
->selected_frame_level
);
9039 /* Restore inferior session state to INF_STATUS. */
9042 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9044 struct thread_info
*tp
= inferior_thread ();
9045 struct inferior
*inf
= current_inferior ();
9047 if (tp
->control
.step_resume_breakpoint
)
9048 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9050 if (tp
->control
.exception_resume_breakpoint
)
9051 tp
->control
.exception_resume_breakpoint
->disposition
9052 = disp_del_at_next_stop
;
9054 /* Handle the bpstat_copy of the chain. */
9055 bpstat_clear (&tp
->control
.stop_bpstat
);
9057 tp
->control
= inf_status
->thread_control
;
9058 inf
->control
= inf_status
->inferior_control
;
9061 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9062 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9064 if (target_has_stack ())
9066 restore_selected_frame (inf_status
->selected_frame_id
,
9067 inf_status
->selected_frame_level
);
9074 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9076 if (inf_status
->thread_control
.step_resume_breakpoint
)
9077 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9078 = disp_del_at_next_stop
;
9080 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9081 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9082 = disp_del_at_next_stop
;
9084 /* See save_infcall_control_state for info on stop_bpstat. */
9085 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9093 clear_exit_convenience_vars (void)
9095 clear_internalvar (lookup_internalvar ("_exitsignal"));
9096 clear_internalvar (lookup_internalvar ("_exitcode"));
9100 /* User interface for reverse debugging:
9101 Set exec-direction / show exec-direction commands
9102 (returns error unless target implements to_set_exec_direction method). */
9104 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9105 static const char exec_forward
[] = "forward";
9106 static const char exec_reverse
[] = "reverse";
9107 static const char *exec_direction
= exec_forward
;
9108 static const char *const exec_direction_names
[] = {
9115 set_exec_direction_func (const char *args
, int from_tty
,
9116 struct cmd_list_element
*cmd
)
9118 if (target_can_execute_reverse ())
9120 if (!strcmp (exec_direction
, exec_forward
))
9121 execution_direction
= EXEC_FORWARD
;
9122 else if (!strcmp (exec_direction
, exec_reverse
))
9123 execution_direction
= EXEC_REVERSE
;
9127 exec_direction
= exec_forward
;
9128 error (_("Target does not support this operation."));
9133 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9134 struct cmd_list_element
*cmd
, const char *value
)
9136 switch (execution_direction
) {
9138 fprintf_filtered (out
, _("Forward.\n"));
9141 fprintf_filtered (out
, _("Reverse.\n"));
9144 internal_error (__FILE__
, __LINE__
,
9145 _("bogus execution_direction value: %d"),
9146 (int) execution_direction
);
9151 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9152 struct cmd_list_element
*c
, const char *value
)
9154 fprintf_filtered (file
, _("Resuming the execution of threads "
9155 "of all processes is %s.\n"), value
);
9158 /* Implementation of `siginfo' variable. */
9160 static const struct internalvar_funcs siginfo_funcs
=
9167 /* Callback for infrun's target events source. This is marked when a
9168 thread has a pending status to process. */
9171 infrun_async_inferior_event_handler (gdb_client_data data
)
9173 inferior_event_handler (INF_REG_EVENT
);
9180 /* Verify that when two threads with the same ptid exist (from two different
9181 targets) and one of them changes ptid, we only update inferior_ptid if
9182 it is appropriate. */
9185 infrun_thread_ptid_changed ()
9187 gdbarch
*arch
= current_inferior ()->gdbarch
;
9189 /* The thread which inferior_ptid represents changes ptid. */
9191 scoped_restore_current_pspace_and_thread restore
;
9193 scoped_mock_context
<test_target_ops
> target1 (arch
);
9194 scoped_mock_context
<test_target_ops
> target2 (arch
);
9195 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9197 ptid_t
old_ptid (111, 222);
9198 ptid_t
new_ptid (111, 333);
9200 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9201 target1
.mock_thread
.ptid
= old_ptid
;
9202 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9203 target2
.mock_thread
.ptid
= old_ptid
;
9205 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9206 set_current_inferior (&target1
.mock_inferior
);
9208 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9210 gdb_assert (inferior_ptid
== new_ptid
);
9213 /* A thread with the same ptid as inferior_ptid, but from another target,
9216 scoped_restore_current_pspace_and_thread restore
;
9218 scoped_mock_context
<test_target_ops
> target1 (arch
);
9219 scoped_mock_context
<test_target_ops
> target2 (arch
);
9220 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9222 ptid_t
old_ptid (111, 222);
9223 ptid_t
new_ptid (111, 333);
9225 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9226 target1
.mock_thread
.ptid
= old_ptid
;
9227 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9228 target2
.mock_thread
.ptid
= old_ptid
;
9230 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9231 set_current_inferior (&target2
.mock_inferior
);
9233 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9235 gdb_assert (inferior_ptid
== old_ptid
);
9239 } /* namespace selftests */
9241 #endif /* GDB_SELF_TEST */
9243 void _initialize_infrun ();
9245 _initialize_infrun ()
9247 struct cmd_list_element
*c
;
9249 /* Register extra event sources in the event loop. */
9250 infrun_async_inferior_event_token
9251 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9254 add_info ("signals", info_signals_command
, _("\
9255 What debugger does when program gets various signals.\n\
9256 Specify a signal as argument to print info on that signal only."));
9257 add_info_alias ("handle", "signals", 0);
9259 c
= add_com ("handle", class_run
, handle_command
, _("\
9260 Specify how to handle signals.\n\
9261 Usage: handle SIGNAL [ACTIONS]\n\
9262 Args are signals and actions to apply to those signals.\n\
9263 If no actions are specified, the current settings for the specified signals\n\
9264 will be displayed instead.\n\
9266 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9267 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9268 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9269 The special arg \"all\" is recognized to mean all signals except those\n\
9270 used by the debugger, typically SIGTRAP and SIGINT.\n\
9272 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9273 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9274 Stop means reenter debugger if this signal happens (implies print).\n\
9275 Print means print a message if this signal happens.\n\
9276 Pass means let program see this signal; otherwise program doesn't know.\n\
9277 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9278 Pass and Stop may be combined.\n\
9280 Multiple signals may be specified. Signal numbers and signal names\n\
9281 may be interspersed with actions, with the actions being performed for\n\
9282 all signals cumulatively specified."));
9283 set_cmd_completer (c
, handle_completer
);
9286 stop_command
= add_cmd ("stop", class_obscure
,
9287 not_just_help_class_command
, _("\
9288 There is no `stop' command, but you can set a hook on `stop'.\n\
9289 This allows you to set a list of commands to be run each time execution\n\
9290 of the program stops."), &cmdlist
);
9292 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9293 Set inferior debugging."), _("\
9294 Show inferior debugging."), _("\
9295 When non-zero, inferior specific debugging is enabled."),
9298 &setdebuglist
, &showdebuglist
);
9300 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9301 &debug_displaced
, _("\
9302 Set displaced stepping debugging."), _("\
9303 Show displaced stepping debugging."), _("\
9304 When non-zero, displaced stepping specific debugging is enabled."),
9306 show_debug_displaced
,
9307 &setdebuglist
, &showdebuglist
);
9309 add_setshow_boolean_cmd ("non-stop", no_class
,
9311 Set whether gdb controls the inferior in non-stop mode."), _("\
9312 Show whether gdb controls the inferior in non-stop mode."), _("\
9313 When debugging a multi-threaded program and this setting is\n\
9314 off (the default, also called all-stop mode), when one thread stops\n\
9315 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9316 all other threads in the program while you interact with the thread of\n\
9317 interest. When you continue or step a thread, you can allow the other\n\
9318 threads to run, or have them remain stopped, but while you inspect any\n\
9319 thread's state, all threads stop.\n\
9321 In non-stop mode, when one thread stops, other threads can continue\n\
9322 to run freely. You'll be able to step each thread independently,\n\
9323 leave it stopped or free to run as needed."),
9329 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9332 signal_print
[i
] = 1;
9333 signal_program
[i
] = 1;
9334 signal_catch
[i
] = 0;
9337 /* Signals caused by debugger's own actions should not be given to
9338 the program afterwards.
9340 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9341 explicitly specifies that it should be delivered to the target
9342 program. Typically, that would occur when a user is debugging a
9343 target monitor on a simulator: the target monitor sets a
9344 breakpoint; the simulator encounters this breakpoint and halts
9345 the simulation handing control to GDB; GDB, noting that the stop
9346 address doesn't map to any known breakpoint, returns control back
9347 to the simulator; the simulator then delivers the hardware
9348 equivalent of a GDB_SIGNAL_TRAP to the program being
9350 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9351 signal_program
[GDB_SIGNAL_INT
] = 0;
9353 /* Signals that are not errors should not normally enter the debugger. */
9354 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9355 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9356 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9357 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9358 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9359 signal_print
[GDB_SIGNAL_PROF
] = 0;
9360 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9361 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9362 signal_stop
[GDB_SIGNAL_IO
] = 0;
9363 signal_print
[GDB_SIGNAL_IO
] = 0;
9364 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9365 signal_print
[GDB_SIGNAL_POLL
] = 0;
9366 signal_stop
[GDB_SIGNAL_URG
] = 0;
9367 signal_print
[GDB_SIGNAL_URG
] = 0;
9368 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9369 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9370 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9371 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9373 /* These signals are used internally by user-level thread
9374 implementations. (See signal(5) on Solaris.) Like the above
9375 signals, a healthy program receives and handles them as part of
9376 its normal operation. */
9377 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9378 signal_print
[GDB_SIGNAL_LWP
] = 0;
9379 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9380 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9381 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9382 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9383 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9384 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9386 /* Update cached state. */
9387 signal_cache_update (-1);
9389 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9390 &stop_on_solib_events
, _("\
9391 Set stopping for shared library events."), _("\
9392 Show stopping for shared library events."), _("\
9393 If nonzero, gdb will give control to the user when the dynamic linker\n\
9394 notifies gdb of shared library events. The most common event of interest\n\
9395 to the user would be loading/unloading of a new library."),
9396 set_stop_on_solib_events
,
9397 show_stop_on_solib_events
,
9398 &setlist
, &showlist
);
9400 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9401 follow_fork_mode_kind_names
,
9402 &follow_fork_mode_string
, _("\
9403 Set debugger response to a program call of fork or vfork."), _("\
9404 Show debugger response to a program call of fork or vfork."), _("\
9405 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9406 parent - the original process is debugged after a fork\n\
9407 child - the new process is debugged after a fork\n\
9408 The unfollowed process will continue to run.\n\
9409 By default, the debugger will follow the parent process."),
9411 show_follow_fork_mode_string
,
9412 &setlist
, &showlist
);
9414 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9415 follow_exec_mode_names
,
9416 &follow_exec_mode_string
, _("\
9417 Set debugger response to a program call of exec."), _("\
9418 Show debugger response to a program call of exec."), _("\
9419 An exec call replaces the program image of a process.\n\
9421 follow-exec-mode can be:\n\
9423 new - the debugger creates a new inferior and rebinds the process\n\
9424 to this new inferior. The program the process was running before\n\
9425 the exec call can be restarted afterwards by restarting the original\n\
9428 same - the debugger keeps the process bound to the same inferior.\n\
9429 The new executable image replaces the previous executable loaded in\n\
9430 the inferior. Restarting the inferior after the exec call restarts\n\
9431 the executable the process was running after the exec call.\n\
9433 By default, the debugger will use the same inferior."),
9435 show_follow_exec_mode_string
,
9436 &setlist
, &showlist
);
9438 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9439 scheduler_enums
, &scheduler_mode
, _("\
9440 Set mode for locking scheduler during execution."), _("\
9441 Show mode for locking scheduler during execution."), _("\
9442 off == no locking (threads may preempt at any time)\n\
9443 on == full locking (no thread except the current thread may run)\n\
9444 This applies to both normal execution and replay mode.\n\
9445 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9446 In this mode, other threads may run during other commands.\n\
9447 This applies to both normal execution and replay mode.\n\
9448 replay == scheduler locked in replay mode and unlocked during normal execution."),
9449 set_schedlock_func
, /* traps on target vector */
9450 show_scheduler_mode
,
9451 &setlist
, &showlist
);
9453 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9454 Set mode for resuming threads of all processes."), _("\
9455 Show mode for resuming threads of all processes."), _("\
9456 When on, execution commands (such as 'continue' or 'next') resume all\n\
9457 threads of all processes. When off (which is the default), execution\n\
9458 commands only resume the threads of the current process. The set of\n\
9459 threads that are resumed is further refined by the scheduler-locking\n\
9460 mode (see help set scheduler-locking)."),
9462 show_schedule_multiple
,
9463 &setlist
, &showlist
);
9465 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9466 Set mode of the step operation."), _("\
9467 Show mode of the step operation."), _("\
9468 When set, doing a step over a function without debug line information\n\
9469 will stop at the first instruction of that function. Otherwise, the\n\
9470 function is skipped and the step command stops at a different source line."),
9472 show_step_stop_if_no_debug
,
9473 &setlist
, &showlist
);
9475 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9476 &can_use_displaced_stepping
, _("\
9477 Set debugger's willingness to use displaced stepping."), _("\
9478 Show debugger's willingness to use displaced stepping."), _("\
9479 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9480 supported by the target architecture. If off, gdb will not use displaced\n\
9481 stepping to step over breakpoints, even if such is supported by the target\n\
9482 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9483 if the target architecture supports it and non-stop mode is active, but will not\n\
9484 use it in all-stop mode (see help set non-stop)."),
9486 show_can_use_displaced_stepping
,
9487 &setlist
, &showlist
);
9489 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9490 &exec_direction
, _("Set direction of execution.\n\
9491 Options are 'forward' or 'reverse'."),
9492 _("Show direction of execution (forward/reverse)."),
9493 _("Tells gdb whether to execute forward or backward."),
9494 set_exec_direction_func
, show_exec_direction_func
,
9495 &setlist
, &showlist
);
9497 /* Set/show detach-on-fork: user-settable mode. */
9499 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9500 Set whether gdb will detach the child of a fork."), _("\
9501 Show whether gdb will detach the child of a fork."), _("\
9502 Tells gdb whether to detach the child of a fork."),
9503 NULL
, NULL
, &setlist
, &showlist
);
9505 /* Set/show disable address space randomization mode. */
9507 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9508 &disable_randomization
, _("\
9509 Set disabling of debuggee's virtual address space randomization."), _("\
9510 Show disabling of debuggee's virtual address space randomization."), _("\
9511 When this mode is on (which is the default), randomization of the virtual\n\
9512 address space is disabled. Standalone programs run with the randomization\n\
9513 enabled by default on some platforms."),
9514 &set_disable_randomization
,
9515 &show_disable_randomization
,
9516 &setlist
, &showlist
);
9518 /* ptid initializations */
9519 inferior_ptid
= null_ptid
;
9520 target_last_wait_ptid
= minus_one_ptid
;
9522 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9523 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9524 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9525 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9526 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
);
9528 /* Explicitly create without lookup, since that tries to create a
9529 value with a void typed value, and when we get here, gdbarch
9530 isn't initialized yet. At this point, we're quite sure there
9531 isn't another convenience variable of the same name. */
9532 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9534 add_setshow_boolean_cmd ("observer", no_class
,
9535 &observer_mode_1
, _("\
9536 Set whether gdb controls the inferior in observer mode."), _("\
9537 Show whether gdb controls the inferior in observer mode."), _("\
9538 In observer mode, GDB can get data from the inferior, but not\n\
9539 affect its execution. Registers and memory may not be changed,\n\
9540 breakpoints may not be set, and the program cannot be interrupted\n\
9548 selftests::register_test ("infrun_thread_ptid_changed",
9549 selftests::infrun_thread_ptid_changed
);