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"
23 #include "gdbsupport/common-defs.h"
24 #include "gdbsupport/common-utils.h"
30 #include "breakpoint.h"
34 #include "target-connection.h"
35 #include "gdbthread.h"
43 #include "observable.h"
48 #include "mi/mi-common.h"
49 #include "event-top.h"
51 #include "record-full.h"
52 #include "inline-frame.h"
54 #include "tracepoint.h"
58 #include "completer.h"
59 #include "target-descriptions.h"
60 #include "target-dcache.h"
63 #include "gdbsupport/event-loop.h"
64 #include "thread-fsm.h"
65 #include "gdbsupport/enum-flags.h"
66 #include "progspace-and-thread.h"
67 #include "gdbsupport/gdb_optional.h"
68 #include "arch-utils.h"
69 #include "gdbsupport/scope-exit.h"
70 #include "gdbsupport/forward-scope-exit.h"
71 #include "gdbsupport/gdb_select.h"
72 #include <unordered_map>
73 #include "async-event.h"
75 /* Prototypes for local functions */
77 static void sig_print_info (enum gdb_signal
);
79 static void sig_print_header (void);
81 static void follow_inferior_reset_breakpoints (void);
83 static int currently_stepping (struct thread_info
*tp
);
85 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
87 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
89 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
91 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
93 static void resume (gdb_signal sig
);
95 static void wait_for_inferior (inferior
*inf
);
97 /* Asynchronous signal handler registered as event loop source for
98 when we have pending events ready to be passed to the core. */
99 static struct async_event_handler
*infrun_async_inferior_event_token
;
101 /* Stores whether infrun_async was previously enabled or disabled.
102 Starts off as -1, indicating "never enabled/disabled". */
103 static int infrun_is_async
= -1;
105 #define infrun_log_debug(fmt, args...) \
106 infrun_log_debug_1 (__LINE__, __func__, fmt, ##args)
108 static void ATTRIBUTE_PRINTF(3, 4)
109 infrun_log_debug_1 (int line
, const char *func
,
110 const char *fmt
, ...)
115 va_start (args
, fmt
);
116 std::string msg
= string_vprintf (fmt
, args
);
119 fprintf_unfiltered (gdb_stdout
, "infrun: %s: %s\n", func
, msg
.c_str ());
126 infrun_async (int enable
)
128 if (infrun_is_async
!= enable
)
130 infrun_is_async
= enable
;
132 infrun_log_debug ("enable=%d", enable
);
135 mark_async_event_handler (infrun_async_inferior_event_token
);
137 clear_async_event_handler (infrun_async_inferior_event_token
);
144 mark_infrun_async_event_handler (void)
146 mark_async_event_handler (infrun_async_inferior_event_token
);
149 /* When set, stop the 'step' command if we enter a function which has
150 no line number information. The normal behavior is that we step
151 over such function. */
152 bool step_stop_if_no_debug
= false;
154 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
155 struct cmd_list_element
*c
, const char *value
)
157 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
160 /* proceed and normal_stop use this to notify the user when the
161 inferior stopped in a different thread than it had been running
164 static ptid_t previous_inferior_ptid
;
166 /* If set (default for legacy reasons), when following a fork, GDB
167 will detach from one of the fork branches, child or parent.
168 Exactly which branch is detached depends on 'set follow-fork-mode'
171 static bool detach_fork
= true;
173 bool debug_displaced
= false;
175 show_debug_displaced (struct ui_file
*file
, int from_tty
,
176 struct cmd_list_element
*c
, const char *value
)
178 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
181 unsigned int debug_infrun
= 0;
183 show_debug_infrun (struct ui_file
*file
, int from_tty
,
184 struct cmd_list_element
*c
, const char *value
)
186 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
190 /* Support for disabling address space randomization. */
192 bool disable_randomization
= true;
195 show_disable_randomization (struct ui_file
*file
, int from_tty
,
196 struct cmd_list_element
*c
, const char *value
)
198 if (target_supports_disable_randomization ())
199 fprintf_filtered (file
,
200 _("Disabling randomization of debuggee's "
201 "virtual address space is %s.\n"),
204 fputs_filtered (_("Disabling randomization of debuggee's "
205 "virtual address space is unsupported on\n"
206 "this platform.\n"), file
);
210 set_disable_randomization (const char *args
, int from_tty
,
211 struct cmd_list_element
*c
)
213 if (!target_supports_disable_randomization ())
214 error (_("Disabling randomization of debuggee's "
215 "virtual address space is unsupported on\n"
219 /* User interface for non-stop mode. */
221 bool non_stop
= false;
222 static bool non_stop_1
= false;
225 set_non_stop (const char *args
, int from_tty
,
226 struct cmd_list_element
*c
)
228 if (target_has_execution
)
230 non_stop_1
= non_stop
;
231 error (_("Cannot change this setting while the inferior is running."));
234 non_stop
= non_stop_1
;
238 show_non_stop (struct ui_file
*file
, int from_tty
,
239 struct cmd_list_element
*c
, const char *value
)
241 fprintf_filtered (file
,
242 _("Controlling the inferior in non-stop mode is %s.\n"),
246 /* "Observer mode" is somewhat like a more extreme version of
247 non-stop, in which all GDB operations that might affect the
248 target's execution have been disabled. */
250 bool observer_mode
= false;
251 static bool observer_mode_1
= false;
254 set_observer_mode (const char *args
, int from_tty
,
255 struct cmd_list_element
*c
)
257 if (target_has_execution
)
259 observer_mode_1
= observer_mode
;
260 error (_("Cannot change this setting while the inferior is running."));
263 observer_mode
= observer_mode_1
;
265 may_write_registers
= !observer_mode
;
266 may_write_memory
= !observer_mode
;
267 may_insert_breakpoints
= !observer_mode
;
268 may_insert_tracepoints
= !observer_mode
;
269 /* We can insert fast tracepoints in or out of observer mode,
270 but enable them if we're going into this mode. */
272 may_insert_fast_tracepoints
= true;
273 may_stop
= !observer_mode
;
274 update_target_permissions ();
276 /* Going *into* observer mode we must force non-stop, then
277 going out we leave it that way. */
280 pagination_enabled
= 0;
281 non_stop
= non_stop_1
= true;
285 printf_filtered (_("Observer mode is now %s.\n"),
286 (observer_mode
? "on" : "off"));
290 show_observer_mode (struct ui_file
*file
, int from_tty
,
291 struct cmd_list_element
*c
, const char *value
)
293 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
296 /* This updates the value of observer mode based on changes in
297 permissions. Note that we are deliberately ignoring the values of
298 may-write-registers and may-write-memory, since the user may have
299 reason to enable these during a session, for instance to turn on a
300 debugging-related global. */
303 update_observer_mode (void)
305 bool newval
= (!may_insert_breakpoints
306 && !may_insert_tracepoints
307 && may_insert_fast_tracepoints
311 /* Let the user know if things change. */
312 if (newval
!= observer_mode
)
313 printf_filtered (_("Observer mode is now %s.\n"),
314 (newval
? "on" : "off"));
316 observer_mode
= observer_mode_1
= newval
;
319 /* Tables of how to react to signals; the user sets them. */
321 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
322 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
323 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
325 /* Table of signals that are registered with "catch signal". A
326 non-zero entry indicates that the signal is caught by some "catch
328 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
330 /* Table of signals that the target may silently handle.
331 This is automatically determined from the flags above,
332 and simply cached here. */
333 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
335 #define SET_SIGS(nsigs,sigs,flags) \
337 int signum = (nsigs); \
338 while (signum-- > 0) \
339 if ((sigs)[signum]) \
340 (flags)[signum] = 1; \
343 #define UNSET_SIGS(nsigs,sigs,flags) \
345 int signum = (nsigs); \
346 while (signum-- > 0) \
347 if ((sigs)[signum]) \
348 (flags)[signum] = 0; \
351 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
352 this function is to avoid exporting `signal_program'. */
355 update_signals_program_target (void)
357 target_program_signals (signal_program
);
360 /* Value to pass to target_resume() to cause all threads to resume. */
362 #define RESUME_ALL minus_one_ptid
364 /* Command list pointer for the "stop" placeholder. */
366 static struct cmd_list_element
*stop_command
;
368 /* Nonzero if we want to give control to the user when we're notified
369 of shared library events by the dynamic linker. */
370 int stop_on_solib_events
;
372 /* Enable or disable optional shared library event breakpoints
373 as appropriate when the above flag is changed. */
376 set_stop_on_solib_events (const char *args
,
377 int from_tty
, struct cmd_list_element
*c
)
379 update_solib_breakpoints ();
383 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
384 struct cmd_list_element
*c
, const char *value
)
386 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
390 /* Nonzero after stop if current stack frame should be printed. */
392 static int stop_print_frame
;
394 /* This is a cached copy of the target/ptid/waitstatus of the last
395 event returned by target_wait()/deprecated_target_wait_hook().
396 This information is returned by get_last_target_status(). */
397 static process_stratum_target
*target_last_proc_target
;
398 static ptid_t target_last_wait_ptid
;
399 static struct target_waitstatus target_last_waitstatus
;
401 void init_thread_stepping_state (struct thread_info
*tss
);
403 static const char follow_fork_mode_child
[] = "child";
404 static const char follow_fork_mode_parent
[] = "parent";
406 static const char *const follow_fork_mode_kind_names
[] = {
407 follow_fork_mode_child
,
408 follow_fork_mode_parent
,
412 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
414 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
415 struct cmd_list_element
*c
, const char *value
)
417 fprintf_filtered (file
,
418 _("Debugger response to a program "
419 "call of fork or vfork is \"%s\".\n"),
424 /* Handle changes to the inferior list based on the type of fork,
425 which process is being followed, and whether the other process
426 should be detached. On entry inferior_ptid must be the ptid of
427 the fork parent. At return inferior_ptid is the ptid of the
428 followed inferior. */
431 follow_fork_inferior (bool follow_child
, bool detach_fork
)
434 ptid_t parent_ptid
, child_ptid
;
436 has_vforked
= (inferior_thread ()->pending_follow
.kind
437 == TARGET_WAITKIND_VFORKED
);
438 parent_ptid
= inferior_ptid
;
439 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
442 && !non_stop
/* Non-stop always resumes both branches. */
443 && current_ui
->prompt_state
== PROMPT_BLOCKED
444 && !(follow_child
|| detach_fork
|| sched_multi
))
446 /* The parent stays blocked inside the vfork syscall until the
447 child execs or exits. If we don't let the child run, then
448 the parent stays blocked. If we're telling the parent to run
449 in the foreground, the user will not be able to ctrl-c to get
450 back the terminal, effectively hanging the debug session. */
451 fprintf_filtered (gdb_stderr
, _("\
452 Can not resume the parent process over vfork in the foreground while\n\
453 holding the child stopped. Try \"set detach-on-fork\" or \
454 \"set schedule-multiple\".\n"));
460 /* Detach new forked process? */
463 /* Before detaching from the child, remove all breakpoints
464 from it. If we forked, then this has already been taken
465 care of by infrun.c. If we vforked however, any
466 breakpoint inserted in the parent is visible in the
467 child, even those added while stopped in a vfork
468 catchpoint. This will remove the breakpoints from the
469 parent also, but they'll be reinserted below. */
472 /* Keep breakpoints list in sync. */
473 remove_breakpoints_inf (current_inferior ());
476 if (print_inferior_events
)
478 /* Ensure that we have a process ptid. */
479 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
481 target_terminal::ours_for_output ();
482 fprintf_filtered (gdb_stdlog
,
483 _("[Detaching after %s from child %s]\n"),
484 has_vforked
? "vfork" : "fork",
485 target_pid_to_str (process_ptid
).c_str ());
490 struct inferior
*parent_inf
, *child_inf
;
492 /* Add process to GDB's tables. */
493 child_inf
= add_inferior (child_ptid
.pid ());
495 parent_inf
= current_inferior ();
496 child_inf
->attach_flag
= parent_inf
->attach_flag
;
497 copy_terminal_info (child_inf
, parent_inf
);
498 child_inf
->gdbarch
= parent_inf
->gdbarch
;
499 copy_inferior_target_desc_info (child_inf
, parent_inf
);
501 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
503 set_current_inferior (child_inf
);
504 switch_to_no_thread ();
505 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
506 push_target (parent_inf
->process_target ());
507 thread_info
*child_thr
508 = add_thread_silent (child_inf
->process_target (), child_ptid
);
510 /* If this is a vfork child, then the address-space is
511 shared with the parent. */
514 child_inf
->pspace
= parent_inf
->pspace
;
515 child_inf
->aspace
= parent_inf
->aspace
;
519 /* The parent will be frozen until the child is done
520 with the shared region. Keep track of the
522 child_inf
->vfork_parent
= parent_inf
;
523 child_inf
->pending_detach
= 0;
524 parent_inf
->vfork_child
= child_inf
;
525 parent_inf
->pending_detach
= 0;
527 /* Now that the inferiors and program spaces are all
528 wired up, we can switch to the child thread (which
529 switches inferior and program space too). */
530 switch_to_thread (child_thr
);
534 child_inf
->aspace
= new_address_space ();
535 child_inf
->pspace
= new program_space (child_inf
->aspace
);
536 child_inf
->removable
= 1;
537 set_current_program_space (child_inf
->pspace
);
538 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
540 /* solib_create_inferior_hook relies on the current
542 switch_to_thread (child_thr
);
544 /* Let the shared library layer (e.g., solib-svr4) learn
545 about this new process, relocate the cloned exec, pull
546 in shared libraries, and install the solib event
547 breakpoint. If a "cloned-VM" event was propagated
548 better throughout the core, this wouldn't be
550 solib_create_inferior_hook (0);
556 struct inferior
*parent_inf
;
558 parent_inf
= current_inferior ();
560 /* If we detached from the child, then we have to be careful
561 to not insert breakpoints in the parent until the child
562 is done with the shared memory region. However, if we're
563 staying attached to the child, then we can and should
564 insert breakpoints, so that we can debug it. A
565 subsequent child exec or exit is enough to know when does
566 the child stops using the parent's address space. */
567 parent_inf
->waiting_for_vfork_done
= detach_fork
;
568 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
573 /* Follow the child. */
574 struct inferior
*parent_inf
, *child_inf
;
575 struct program_space
*parent_pspace
;
577 if (print_inferior_events
)
579 std::string parent_pid
= target_pid_to_str (parent_ptid
);
580 std::string child_pid
= target_pid_to_str (child_ptid
);
582 target_terminal::ours_for_output ();
583 fprintf_filtered (gdb_stdlog
,
584 _("[Attaching after %s %s to child %s]\n"),
586 has_vforked
? "vfork" : "fork",
590 /* Add the new inferior first, so that the target_detach below
591 doesn't unpush the target. */
593 child_inf
= add_inferior (child_ptid
.pid ());
595 parent_inf
= current_inferior ();
596 child_inf
->attach_flag
= parent_inf
->attach_flag
;
597 copy_terminal_info (child_inf
, parent_inf
);
598 child_inf
->gdbarch
= parent_inf
->gdbarch
;
599 copy_inferior_target_desc_info (child_inf
, parent_inf
);
601 parent_pspace
= parent_inf
->pspace
;
603 process_stratum_target
*target
= parent_inf
->process_target ();
606 /* Hold a strong reference to the target while (maybe)
607 detaching the parent. Otherwise detaching could close the
609 auto target_ref
= target_ops_ref::new_reference (target
);
611 /* If we're vforking, we want to hold on to the parent until
612 the child exits or execs. At child exec or exit time we
613 can remove the old breakpoints from the parent and detach
614 or resume debugging it. Otherwise, detach the parent now;
615 we'll want to reuse it's program/address spaces, but we
616 can't set them to the child before removing breakpoints
617 from the parent, otherwise, the breakpoints module could
618 decide to remove breakpoints from the wrong process (since
619 they'd be assigned to the same address space). */
623 gdb_assert (child_inf
->vfork_parent
== NULL
);
624 gdb_assert (parent_inf
->vfork_child
== NULL
);
625 child_inf
->vfork_parent
= parent_inf
;
626 child_inf
->pending_detach
= 0;
627 parent_inf
->vfork_child
= child_inf
;
628 parent_inf
->pending_detach
= detach_fork
;
629 parent_inf
->waiting_for_vfork_done
= 0;
631 else if (detach_fork
)
633 if (print_inferior_events
)
635 /* Ensure that we have a process ptid. */
636 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
638 target_terminal::ours_for_output ();
639 fprintf_filtered (gdb_stdlog
,
640 _("[Detaching after fork from "
642 target_pid_to_str (process_ptid
).c_str ());
645 target_detach (parent_inf
, 0);
649 /* Note that the detach above makes PARENT_INF dangling. */
651 /* Add the child thread to the appropriate lists, and switch
652 to this new thread, before cloning the program space, and
653 informing the solib layer about this new process. */
655 set_current_inferior (child_inf
);
656 push_target (target
);
659 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
661 /* If this is a vfork child, then the address-space is shared
662 with the parent. If we detached from the parent, then we can
663 reuse the parent's program/address spaces. */
664 if (has_vforked
|| detach_fork
)
666 child_inf
->pspace
= parent_pspace
;
667 child_inf
->aspace
= child_inf
->pspace
->aspace
;
673 child_inf
->aspace
= new_address_space ();
674 child_inf
->pspace
= new program_space (child_inf
->aspace
);
675 child_inf
->removable
= 1;
676 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
677 set_current_program_space (child_inf
->pspace
);
678 clone_program_space (child_inf
->pspace
, parent_pspace
);
680 /* Let the shared library layer (e.g., solib-svr4) learn
681 about this new process, relocate the cloned exec, pull in
682 shared libraries, and install the solib event breakpoint.
683 If a "cloned-VM" event was propagated better throughout
684 the core, this wouldn't be required. */
685 solib_create_inferior_hook (0);
688 switch_to_thread (child_thr
);
691 return target_follow_fork (follow_child
, detach_fork
);
694 /* Tell the target to follow the fork we're stopped at. Returns true
695 if the inferior should be resumed; false, if the target for some
696 reason decided it's best not to resume. */
701 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
702 bool should_resume
= true;
703 struct thread_info
*tp
;
705 /* Copy user stepping state to the new inferior thread. FIXME: the
706 followed fork child thread should have a copy of most of the
707 parent thread structure's run control related fields, not just these.
708 Initialized to avoid "may be used uninitialized" warnings from gcc. */
709 struct breakpoint
*step_resume_breakpoint
= NULL
;
710 struct breakpoint
*exception_resume_breakpoint
= NULL
;
711 CORE_ADDR step_range_start
= 0;
712 CORE_ADDR step_range_end
= 0;
713 int current_line
= 0;
714 symtab
*current_symtab
= NULL
;
715 struct frame_id step_frame_id
= { 0 };
716 struct thread_fsm
*thread_fsm
= NULL
;
720 process_stratum_target
*wait_target
;
722 struct target_waitstatus wait_status
;
724 /* Get the last target status returned by target_wait(). */
725 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
727 /* If not stopped at a fork event, then there's nothing else to
729 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
730 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
733 /* Check if we switched over from WAIT_PTID, since the event was
735 if (wait_ptid
!= minus_one_ptid
736 && (current_inferior ()->process_target () != wait_target
737 || inferior_ptid
!= wait_ptid
))
739 /* We did. Switch back to WAIT_PTID thread, to tell the
740 target to follow it (in either direction). We'll
741 afterwards refuse to resume, and inform the user what
743 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
744 switch_to_thread (wait_thread
);
745 should_resume
= false;
749 tp
= inferior_thread ();
751 /* If there were any forks/vforks that were caught and are now to be
752 followed, then do so now. */
753 switch (tp
->pending_follow
.kind
)
755 case TARGET_WAITKIND_FORKED
:
756 case TARGET_WAITKIND_VFORKED
:
758 ptid_t parent
, child
;
760 /* If the user did a next/step, etc, over a fork call,
761 preserve the stepping state in the fork child. */
762 if (follow_child
&& should_resume
)
764 step_resume_breakpoint
= clone_momentary_breakpoint
765 (tp
->control
.step_resume_breakpoint
);
766 step_range_start
= tp
->control
.step_range_start
;
767 step_range_end
= tp
->control
.step_range_end
;
768 current_line
= tp
->current_line
;
769 current_symtab
= tp
->current_symtab
;
770 step_frame_id
= tp
->control
.step_frame_id
;
771 exception_resume_breakpoint
772 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
773 thread_fsm
= tp
->thread_fsm
;
775 /* For now, delete the parent's sr breakpoint, otherwise,
776 parent/child sr breakpoints are considered duplicates,
777 and the child version will not be installed. Remove
778 this when the breakpoints module becomes aware of
779 inferiors and address spaces. */
780 delete_step_resume_breakpoint (tp
);
781 tp
->control
.step_range_start
= 0;
782 tp
->control
.step_range_end
= 0;
783 tp
->control
.step_frame_id
= null_frame_id
;
784 delete_exception_resume_breakpoint (tp
);
785 tp
->thread_fsm
= NULL
;
788 parent
= inferior_ptid
;
789 child
= tp
->pending_follow
.value
.related_pid
;
791 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
792 /* Set up inferior(s) as specified by the caller, and tell the
793 target to do whatever is necessary to follow either parent
795 if (follow_fork_inferior (follow_child
, detach_fork
))
797 /* Target refused to follow, or there's some other reason
798 we shouldn't resume. */
803 /* This pending follow fork event is now handled, one way
804 or another. The previous selected thread may be gone
805 from the lists by now, but if it is still around, need
806 to clear the pending follow request. */
807 tp
= find_thread_ptid (parent_targ
, parent
);
809 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
811 /* This makes sure we don't try to apply the "Switched
812 over from WAIT_PID" logic above. */
813 nullify_last_target_wait_ptid ();
815 /* If we followed the child, switch to it... */
818 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
819 switch_to_thread (child_thr
);
821 /* ... and preserve the stepping state, in case the
822 user was stepping over the fork call. */
825 tp
= inferior_thread ();
826 tp
->control
.step_resume_breakpoint
827 = step_resume_breakpoint
;
828 tp
->control
.step_range_start
= step_range_start
;
829 tp
->control
.step_range_end
= step_range_end
;
830 tp
->current_line
= current_line
;
831 tp
->current_symtab
= current_symtab
;
832 tp
->control
.step_frame_id
= step_frame_id
;
833 tp
->control
.exception_resume_breakpoint
834 = exception_resume_breakpoint
;
835 tp
->thread_fsm
= thread_fsm
;
839 /* If we get here, it was because we're trying to
840 resume from a fork catchpoint, but, the user
841 has switched threads away from the thread that
842 forked. In that case, the resume command
843 issued is most likely not applicable to the
844 child, so just warn, and refuse to resume. */
845 warning (_("Not resuming: switched threads "
846 "before following fork child."));
849 /* Reset breakpoints in the child as appropriate. */
850 follow_inferior_reset_breakpoints ();
855 case TARGET_WAITKIND_SPURIOUS
:
856 /* Nothing to follow. */
859 internal_error (__FILE__
, __LINE__
,
860 "Unexpected pending_follow.kind %d\n",
861 tp
->pending_follow
.kind
);
865 return should_resume
;
869 follow_inferior_reset_breakpoints (void)
871 struct thread_info
*tp
= inferior_thread ();
873 /* Was there a step_resume breakpoint? (There was if the user
874 did a "next" at the fork() call.) If so, explicitly reset its
875 thread number. Cloned step_resume breakpoints are disabled on
876 creation, so enable it here now that it is associated with the
879 step_resumes are a form of bp that are made to be per-thread.
880 Since we created the step_resume bp when the parent process
881 was being debugged, and now are switching to the child process,
882 from the breakpoint package's viewpoint, that's a switch of
883 "threads". We must update the bp's notion of which thread
884 it is for, or it'll be ignored when it triggers. */
886 if (tp
->control
.step_resume_breakpoint
)
888 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
889 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
892 /* Treat exception_resume breakpoints like step_resume breakpoints. */
893 if (tp
->control
.exception_resume_breakpoint
)
895 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
896 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
899 /* Reinsert all breakpoints in the child. The user may have set
900 breakpoints after catching the fork, in which case those
901 were never set in the child, but only in the parent. This makes
902 sure the inserted breakpoints match the breakpoint list. */
904 breakpoint_re_set ();
905 insert_breakpoints ();
908 /* The child has exited or execed: resume threads of the parent the
909 user wanted to be executing. */
912 proceed_after_vfork_done (struct thread_info
*thread
,
915 int pid
= * (int *) arg
;
917 if (thread
->ptid
.pid () == pid
918 && thread
->state
== THREAD_RUNNING
919 && !thread
->executing
920 && !thread
->stop_requested
921 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
923 infrun_log_debug ("resuming vfork parent thread %s",
924 target_pid_to_str (thread
->ptid
).c_str ());
926 switch_to_thread (thread
);
927 clear_proceed_status (0);
928 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
934 /* Called whenever we notice an exec or exit event, to handle
935 detaching or resuming a vfork parent. */
938 handle_vfork_child_exec_or_exit (int exec
)
940 struct inferior
*inf
= current_inferior ();
942 if (inf
->vfork_parent
)
944 int resume_parent
= -1;
946 /* This exec or exit marks the end of the shared memory region
947 between the parent and the child. Break the bonds. */
948 inferior
*vfork_parent
= inf
->vfork_parent
;
949 inf
->vfork_parent
->vfork_child
= NULL
;
950 inf
->vfork_parent
= NULL
;
952 /* If the user wanted to detach from the parent, now is the
954 if (vfork_parent
->pending_detach
)
956 struct program_space
*pspace
;
957 struct address_space
*aspace
;
959 /* follow-fork child, detach-on-fork on. */
961 vfork_parent
->pending_detach
= 0;
963 scoped_restore_current_pspace_and_thread restore_thread
;
965 /* We're letting loose of the parent. */
966 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
967 switch_to_thread (tp
);
969 /* We're about to detach from the parent, which implicitly
970 removes breakpoints from its address space. There's a
971 catch here: we want to reuse the spaces for the child,
972 but, parent/child are still sharing the pspace at this
973 point, although the exec in reality makes the kernel give
974 the child a fresh set of new pages. The problem here is
975 that the breakpoints module being unaware of this, would
976 likely chose the child process to write to the parent
977 address space. Swapping the child temporarily away from
978 the spaces has the desired effect. Yes, this is "sort
981 pspace
= inf
->pspace
;
982 aspace
= inf
->aspace
;
986 if (print_inferior_events
)
989 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
991 target_terminal::ours_for_output ();
995 fprintf_filtered (gdb_stdlog
,
996 _("[Detaching vfork parent %s "
997 "after child exec]\n"), pidstr
.c_str ());
1001 fprintf_filtered (gdb_stdlog
,
1002 _("[Detaching vfork parent %s "
1003 "after child exit]\n"), pidstr
.c_str ());
1007 target_detach (vfork_parent
, 0);
1010 inf
->pspace
= pspace
;
1011 inf
->aspace
= aspace
;
1015 /* We're staying attached to the parent, so, really give the
1016 child a new address space. */
1017 inf
->pspace
= new program_space (maybe_new_address_space ());
1018 inf
->aspace
= inf
->pspace
->aspace
;
1020 set_current_program_space (inf
->pspace
);
1022 resume_parent
= vfork_parent
->pid
;
1026 /* If this is a vfork child exiting, then the pspace and
1027 aspaces were shared with the parent. Since we're
1028 reporting the process exit, we'll be mourning all that is
1029 found in the address space, and switching to null_ptid,
1030 preparing to start a new inferior. But, since we don't
1031 want to clobber the parent's address/program spaces, we
1032 go ahead and create a new one for this exiting
1035 /* Switch to no-thread while running clone_program_space, so
1036 that clone_program_space doesn't want to read the
1037 selected frame of a dead process. */
1038 scoped_restore_current_thread restore_thread
;
1039 switch_to_no_thread ();
1041 inf
->pspace
= new program_space (maybe_new_address_space ());
1042 inf
->aspace
= inf
->pspace
->aspace
;
1043 set_current_program_space (inf
->pspace
);
1045 inf
->symfile_flags
= SYMFILE_NO_READ
;
1046 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1048 resume_parent
= vfork_parent
->pid
;
1051 gdb_assert (current_program_space
== inf
->pspace
);
1053 if (non_stop
&& resume_parent
!= -1)
1055 /* If the user wanted the parent to be running, let it go
1057 scoped_restore_current_thread restore_thread
;
1059 infrun_log_debug ("resuming vfork parent process %d",
1062 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1067 /* Enum strings for "set|show follow-exec-mode". */
1069 static const char follow_exec_mode_new
[] = "new";
1070 static const char follow_exec_mode_same
[] = "same";
1071 static const char *const follow_exec_mode_names
[] =
1073 follow_exec_mode_new
,
1074 follow_exec_mode_same
,
1078 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1080 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1081 struct cmd_list_element
*c
, const char *value
)
1083 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1086 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1089 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1091 struct inferior
*inf
= current_inferior ();
1092 int pid
= ptid
.pid ();
1093 ptid_t process_ptid
;
1095 /* Switch terminal for any messages produced e.g. by
1096 breakpoint_re_set. */
1097 target_terminal::ours_for_output ();
1099 /* This is an exec event that we actually wish to pay attention to.
1100 Refresh our symbol table to the newly exec'd program, remove any
1101 momentary bp's, etc.
1103 If there are breakpoints, they aren't really inserted now,
1104 since the exec() transformed our inferior into a fresh set
1107 We want to preserve symbolic breakpoints on the list, since
1108 we have hopes that they can be reset after the new a.out's
1109 symbol table is read.
1111 However, any "raw" breakpoints must be removed from the list
1112 (e.g., the solib bp's), since their address is probably invalid
1115 And, we DON'T want to call delete_breakpoints() here, since
1116 that may write the bp's "shadow contents" (the instruction
1117 value that was overwritten with a TRAP instruction). Since
1118 we now have a new a.out, those shadow contents aren't valid. */
1120 mark_breakpoints_out ();
1122 /* The target reports the exec event to the main thread, even if
1123 some other thread does the exec, and even if the main thread was
1124 stopped or already gone. We may still have non-leader threads of
1125 the process on our list. E.g., on targets that don't have thread
1126 exit events (like remote); or on native Linux in non-stop mode if
1127 there were only two threads in the inferior and the non-leader
1128 one is the one that execs (and nothing forces an update of the
1129 thread list up to here). When debugging remotely, it's best to
1130 avoid extra traffic, when possible, so avoid syncing the thread
1131 list with the target, and instead go ahead and delete all threads
1132 of the process but one that reported the event. Note this must
1133 be done before calling update_breakpoints_after_exec, as
1134 otherwise clearing the threads' resources would reference stale
1135 thread breakpoints -- it may have been one of these threads that
1136 stepped across the exec. We could just clear their stepping
1137 states, but as long as we're iterating, might as well delete
1138 them. Deleting them now rather than at the next user-visible
1139 stop provides a nicer sequence of events for user and MI
1141 for (thread_info
*th
: all_threads_safe ())
1142 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1145 /* We also need to clear any left over stale state for the
1146 leader/event thread. E.g., if there was any step-resume
1147 breakpoint or similar, it's gone now. We cannot truly
1148 step-to-next statement through an exec(). */
1149 thread_info
*th
= inferior_thread ();
1150 th
->control
.step_resume_breakpoint
= NULL
;
1151 th
->control
.exception_resume_breakpoint
= NULL
;
1152 th
->control
.single_step_breakpoints
= NULL
;
1153 th
->control
.step_range_start
= 0;
1154 th
->control
.step_range_end
= 0;
1156 /* The user may have had the main thread held stopped in the
1157 previous image (e.g., schedlock on, or non-stop). Release
1159 th
->stop_requested
= 0;
1161 update_breakpoints_after_exec ();
1163 /* What is this a.out's name? */
1164 process_ptid
= ptid_t (pid
);
1165 printf_unfiltered (_("%s is executing new program: %s\n"),
1166 target_pid_to_str (process_ptid
).c_str (),
1169 /* We've followed the inferior through an exec. Therefore, the
1170 inferior has essentially been killed & reborn. */
1172 breakpoint_init_inferior (inf_execd
);
1174 gdb::unique_xmalloc_ptr
<char> exec_file_host
1175 = exec_file_find (exec_file_target
, NULL
);
1177 /* If we were unable to map the executable target pathname onto a host
1178 pathname, tell the user that. Otherwise GDB's subsequent behavior
1179 is confusing. Maybe it would even be better to stop at this point
1180 so that the user can specify a file manually before continuing. */
1181 if (exec_file_host
== NULL
)
1182 warning (_("Could not load symbols for executable %s.\n"
1183 "Do you need \"set sysroot\"?"),
1186 /* Reset the shared library package. This ensures that we get a
1187 shlib event when the child reaches "_start", at which point the
1188 dld will have had a chance to initialize the child. */
1189 /* Also, loading a symbol file below may trigger symbol lookups, and
1190 we don't want those to be satisfied by the libraries of the
1191 previous incarnation of this process. */
1192 no_shared_libraries (NULL
, 0);
1194 if (follow_exec_mode_string
== follow_exec_mode_new
)
1196 /* The user wants to keep the old inferior and program spaces
1197 around. Create a new fresh one, and switch to it. */
1199 /* Do exit processing for the original inferior before setting the new
1200 inferior's pid. Having two inferiors with the same pid would confuse
1201 find_inferior_p(t)id. Transfer the terminal state and info from the
1202 old to the new inferior. */
1203 inf
= add_inferior_with_spaces ();
1204 swap_terminal_info (inf
, current_inferior ());
1205 exit_inferior_silent (current_inferior ());
1208 target_follow_exec (inf
, exec_file_target
);
1210 inferior
*org_inferior
= current_inferior ();
1211 switch_to_inferior_no_thread (inf
);
1212 push_target (org_inferior
->process_target ());
1213 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1214 switch_to_thread (thr
);
1218 /* The old description may no longer be fit for the new image.
1219 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1220 old description; we'll read a new one below. No need to do
1221 this on "follow-exec-mode new", as the old inferior stays
1222 around (its description is later cleared/refetched on
1224 target_clear_description ();
1227 gdb_assert (current_program_space
== inf
->pspace
);
1229 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1230 because the proper displacement for a PIE (Position Independent
1231 Executable) main symbol file will only be computed by
1232 solib_create_inferior_hook below. breakpoint_re_set would fail
1233 to insert the breakpoints with the zero displacement. */
1234 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1236 /* If the target can specify a description, read it. Must do this
1237 after flipping to the new executable (because the target supplied
1238 description must be compatible with the executable's
1239 architecture, and the old executable may e.g., be 32-bit, while
1240 the new one 64-bit), and before anything involving memory or
1242 target_find_description ();
1244 solib_create_inferior_hook (0);
1246 jit_inferior_created_hook ();
1248 breakpoint_re_set ();
1250 /* Reinsert all breakpoints. (Those which were symbolic have
1251 been reset to the proper address in the new a.out, thanks
1252 to symbol_file_command...). */
1253 insert_breakpoints ();
1255 gdb::observers::inferior_execd
.notify (inf
);
1257 /* The next resume of this inferior should bring it to the shlib
1258 startup breakpoints. (If the user had also set bp's on
1259 "main" from the old (parent) process, then they'll auto-
1260 matically get reset there in the new process.). */
1263 /* The queue of threads that need to do a step-over operation to get
1264 past e.g., a breakpoint. What technique is used to step over the
1265 breakpoint/watchpoint does not matter -- all threads end up in the
1266 same queue, to maintain rough temporal order of execution, in order
1267 to avoid starvation, otherwise, we could e.g., find ourselves
1268 constantly stepping the same couple threads past their breakpoints
1269 over and over, if the single-step finish fast enough. */
1270 struct thread_info
*global_thread_step_over_chain_head
;
1272 /* Bit flags indicating what the thread needs to step over. */
1274 enum step_over_what_flag
1276 /* Step over a breakpoint. */
1277 STEP_OVER_BREAKPOINT
= 1,
1279 /* Step past a non-continuable watchpoint, in order to let the
1280 instruction execute so we can evaluate the watchpoint
1282 STEP_OVER_WATCHPOINT
= 2
1284 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1286 /* Info about an instruction that is being stepped over. */
1288 struct step_over_info
1290 /* If we're stepping past a breakpoint, this is the address space
1291 and address of the instruction the breakpoint is set at. We'll
1292 skip inserting all breakpoints here. Valid iff ASPACE is
1294 const address_space
*aspace
;
1297 /* The instruction being stepped over triggers a nonsteppable
1298 watchpoint. If true, we'll skip inserting watchpoints. */
1299 int nonsteppable_watchpoint_p
;
1301 /* The thread's global number. */
1305 /* The step-over info of the location that is being stepped over.
1307 Note that with async/breakpoint always-inserted mode, a user might
1308 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1309 being stepped over. As setting a new breakpoint inserts all
1310 breakpoints, we need to make sure the breakpoint being stepped over
1311 isn't inserted then. We do that by only clearing the step-over
1312 info when the step-over is actually finished (or aborted).
1314 Presently GDB can only step over one breakpoint at any given time.
1315 Given threads that can't run code in the same address space as the
1316 breakpoint's can't really miss the breakpoint, GDB could be taught
1317 to step-over at most one breakpoint per address space (so this info
1318 could move to the address space object if/when GDB is extended).
1319 The set of breakpoints being stepped over will normally be much
1320 smaller than the set of all breakpoints, so a flag in the
1321 breakpoint location structure would be wasteful. A separate list
1322 also saves complexity and run-time, as otherwise we'd have to go
1323 through all breakpoint locations clearing their flag whenever we
1324 start a new sequence. Similar considerations weigh against storing
1325 this info in the thread object. Plus, not all step overs actually
1326 have breakpoint locations -- e.g., stepping past a single-step
1327 breakpoint, or stepping to complete a non-continuable
1329 static struct step_over_info step_over_info
;
1331 /* Record the address of the breakpoint/instruction we're currently
1333 N.B. We record the aspace and address now, instead of say just the thread,
1334 because when we need the info later the thread may be running. */
1337 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1338 int nonsteppable_watchpoint_p
,
1341 step_over_info
.aspace
= aspace
;
1342 step_over_info
.address
= address
;
1343 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1344 step_over_info
.thread
= thread
;
1347 /* Called when we're not longer stepping over a breakpoint / an
1348 instruction, so all breakpoints are free to be (re)inserted. */
1351 clear_step_over_info (void)
1353 infrun_log_debug ("clearing step over info");
1354 step_over_info
.aspace
= NULL
;
1355 step_over_info
.address
= 0;
1356 step_over_info
.nonsteppable_watchpoint_p
= 0;
1357 step_over_info
.thread
= -1;
1363 stepping_past_instruction_at (struct address_space
*aspace
,
1366 return (step_over_info
.aspace
!= NULL
1367 && breakpoint_address_match (aspace
, address
,
1368 step_over_info
.aspace
,
1369 step_over_info
.address
));
1375 thread_is_stepping_over_breakpoint (int thread
)
1377 return (step_over_info
.thread
!= -1
1378 && thread
== step_over_info
.thread
);
1384 stepping_past_nonsteppable_watchpoint (void)
1386 return step_over_info
.nonsteppable_watchpoint_p
;
1389 /* Returns true if step-over info is valid. */
1392 step_over_info_valid_p (void)
1394 return (step_over_info
.aspace
!= NULL
1395 || stepping_past_nonsteppable_watchpoint ());
1399 /* Displaced stepping. */
1401 /* In non-stop debugging mode, we must take special care to manage
1402 breakpoints properly; in particular, the traditional strategy for
1403 stepping a thread past a breakpoint it has hit is unsuitable.
1404 'Displaced stepping' is a tactic for stepping one thread past a
1405 breakpoint it has hit while ensuring that other threads running
1406 concurrently will hit the breakpoint as they should.
1408 The traditional way to step a thread T off a breakpoint in a
1409 multi-threaded program in all-stop mode is as follows:
1411 a0) Initially, all threads are stopped, and breakpoints are not
1413 a1) We single-step T, leaving breakpoints uninserted.
1414 a2) We insert breakpoints, and resume all threads.
1416 In non-stop debugging, however, this strategy is unsuitable: we
1417 don't want to have to stop all threads in the system in order to
1418 continue or step T past a breakpoint. Instead, we use displaced
1421 n0) Initially, T is stopped, other threads are running, and
1422 breakpoints are inserted.
1423 n1) We copy the instruction "under" the breakpoint to a separate
1424 location, outside the main code stream, making any adjustments
1425 to the instruction, register, and memory state as directed by
1427 n2) We single-step T over the instruction at its new location.
1428 n3) We adjust the resulting register and memory state as directed
1429 by T's architecture. This includes resetting T's PC to point
1430 back into the main instruction stream.
1433 This approach depends on the following gdbarch methods:
1435 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1436 indicate where to copy the instruction, and how much space must
1437 be reserved there. We use these in step n1.
1439 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1440 address, and makes any necessary adjustments to the instruction,
1441 register contents, and memory. We use this in step n1.
1443 - gdbarch_displaced_step_fixup adjusts registers and memory after
1444 we have successfully single-stepped the instruction, to yield the
1445 same effect the instruction would have had if we had executed it
1446 at its original address. We use this in step n3.
1448 The gdbarch_displaced_step_copy_insn and
1449 gdbarch_displaced_step_fixup functions must be written so that
1450 copying an instruction with gdbarch_displaced_step_copy_insn,
1451 single-stepping across the copied instruction, and then applying
1452 gdbarch_displaced_insn_fixup should have the same effects on the
1453 thread's memory and registers as stepping the instruction in place
1454 would have. Exactly which responsibilities fall to the copy and
1455 which fall to the fixup is up to the author of those functions.
1457 See the comments in gdbarch.sh for details.
1459 Note that displaced stepping and software single-step cannot
1460 currently be used in combination, although with some care I think
1461 they could be made to. Software single-step works by placing
1462 breakpoints on all possible subsequent instructions; if the
1463 displaced instruction is a PC-relative jump, those breakpoints
1464 could fall in very strange places --- on pages that aren't
1465 executable, or at addresses that are not proper instruction
1466 boundaries. (We do generally let other threads run while we wait
1467 to hit the software single-step breakpoint, and they might
1468 encounter such a corrupted instruction.) One way to work around
1469 this would be to have gdbarch_displaced_step_copy_insn fully
1470 simulate the effect of PC-relative instructions (and return NULL)
1471 on architectures that use software single-stepping.
1473 In non-stop mode, we can have independent and simultaneous step
1474 requests, so more than one thread may need to simultaneously step
1475 over a breakpoint. The current implementation assumes there is
1476 only one scratch space per process. In this case, we have to
1477 serialize access to the scratch space. If thread A wants to step
1478 over a breakpoint, but we are currently waiting for some other
1479 thread to complete a displaced step, we leave thread A stopped and
1480 place it in the displaced_step_request_queue. Whenever a displaced
1481 step finishes, we pick the next thread in the queue and start a new
1482 displaced step operation on it. See displaced_step_prepare and
1483 displaced_step_fixup for details. */
1485 /* Get the displaced stepping state of inferior INF. */
1487 static displaced_step_inferior_state
*
1488 get_displaced_stepping_state (inferior
*inf
)
1490 return &inf
->displaced_step_state
;
1493 /* Get the displaced stepping state of thread THREAD. */
1495 static displaced_step_thread_state
*
1496 get_displaced_stepping_state (thread_info
*thread
)
1498 return &thread
->displaced_step_state
;
1501 /* Return true if the given thread is doing a displaced step. */
1504 displaced_step_in_progress (thread_info
*thread
)
1506 gdb_assert (thread
!= NULL
);
1508 return get_displaced_stepping_state (thread
)->in_progress ();
1511 /* Return true if any thread of this inferior is doing a displaced step. */
1514 displaced_step_in_progress (inferior
*inf
)
1516 for (thread_info
*thread
: inf
->non_exited_threads ())
1518 if (displaced_step_in_progress (thread
))
1525 /* Return true if any thread is doing a displaced step. */
1528 displaced_step_in_progress_any_thread ()
1530 for (thread_info
*thread
: all_non_exited_threads ())
1532 if (displaced_step_in_progress (thread
))
1539 /* If inferior is in displaced stepping, and ADDR equals to starting address
1540 of copy area, return corresponding displaced_step_copy_insn_closure. Otherwise,
1543 struct displaced_step_copy_insn_closure
*
1544 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1546 // FIXME: implement me (only needed on ARM).
1547 // displaced_step_inferior_state *displaced
1548 // = get_displaced_stepping_state (current_inferior ());
1550 // /* If checking the mode of displaced instruction in copy area. */
1551 // if (displaced->step_thread != nullptr
1552 // && displaced->step_copy == addr)
1553 // return displaced->step_closure.get ();
1559 infrun_inferior_exit (struct inferior
*inf
)
1561 inf
->displaced_step_state
.reset ();
1564 /* If ON, and the architecture supports it, GDB will use displaced
1565 stepping to step over breakpoints. If OFF, or if the architecture
1566 doesn't support it, GDB will instead use the traditional
1567 hold-and-step approach. If AUTO (which is the default), GDB will
1568 decide which technique to use to step over breakpoints depending on
1569 whether the target works in a non-stop way (see use_displaced_stepping). */
1571 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1574 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1575 struct cmd_list_element
*c
,
1578 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1579 fprintf_filtered (file
,
1580 _("Debugger's willingness to use displaced stepping "
1581 "to step over breakpoints is %s (currently %s).\n"),
1582 value
, target_is_non_stop_p () ? "on" : "off");
1584 fprintf_filtered (file
,
1585 _("Debugger's willingness to use displaced stepping "
1586 "to step over breakpoints is %s.\n"), value
);
1589 /* Return true if the gdbarch implements the required methods to use
1590 displaced stepping. */
1593 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1595 /* Only check for the presence of copy_insn. Other required methods
1596 are checked by the gdbarch validation to be provided if copy_insn is
1598 return gdbarch_displaced_step_copy_insn_p (arch
);
1601 /* Return non-zero if displaced stepping can/should be used to step
1602 over breakpoints of thread TP. */
1605 use_displaced_stepping (thread_info
*tp
)
1607 /* If the user disabled it explicitly, don't use displaced stepping. */
1608 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1611 /* If "auto", only use displaced stepping if the target operates in a non-stop
1613 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1614 && !target_is_non_stop_p ())
1617 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1619 /* If the architecture doesn't implement displaced stepping, don't use
1621 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1624 /* If recording, don't use displaced stepping. */
1625 if (find_record_target () != nullptr)
1628 displaced_step_inferior_state
*displaced_state
1629 = get_displaced_stepping_state (tp
->inf
);
1631 /* If displaced stepping failed before for this inferior, don't bother trying
1633 if (displaced_state
->failed_before
)
1639 /* Simple function wrapper around displaced_step_thread_state::reset. */
1642 displaced_step_reset (displaced_step_thread_state
*displaced
)
1644 displaced
->reset ();
1647 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1648 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1650 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1652 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1654 displaced_step_dump_bytes (struct ui_file
*file
,
1655 const gdb_byte
*buf
,
1660 for (i
= 0; i
< len
; i
++)
1661 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1662 fputs_unfiltered ("\n", file
);
1665 /* Prepare to single-step, using displaced stepping.
1667 Note that we cannot use displaced stepping when we have a signal to
1668 deliver. If we have a signal to deliver and an instruction to step
1669 over, then after the step, there will be no indication from the
1670 target whether the thread entered a signal handler or ignored the
1671 signal and stepped over the instruction successfully --- both cases
1672 result in a simple SIGTRAP. In the first case we mustn't do a
1673 fixup, and in the second case we must --- but we can't tell which.
1674 Comments in the code for 'random signals' in handle_inferior_event
1675 explain how we handle this case instead.
1677 Returns 1 if preparing was successful -- this thread is going to be
1678 stepped now; 0 if displaced stepping this thread got queued; or -1
1679 if this instruction can't be displaced stepped. */
1681 static displaced_step_prepare_status
1682 displaced_step_prepare_throw (thread_info
*tp
)
1684 regcache
*regcache
= get_thread_regcache (tp
);
1685 struct gdbarch
*gdbarch
= regcache
->arch ();
1686 displaced_step_thread_state
*thread_disp_step_state
1687 = get_displaced_stepping_state (tp
);
1689 /* We should never reach this function if the architecture does not
1690 support displaced stepping. */
1691 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1693 /* Nor if the thread isn't meant to step over a breakpoint. */
1694 gdb_assert (tp
->control
.trap_expected
);
1696 /* Disable range stepping while executing in the scratch pad. We
1697 want a single-step even if executing the displaced instruction in
1698 the scratch buffer lands within the stepping range (e.g., a
1700 tp
->control
.may_range_step
= 0;
1702 /* We are about to start a displaced step for this thread, if one is already
1703 in progress, we goofed up somewhere. */
1704 gdb_assert (!thread_disp_step_state
->in_progress ());
1706 scoped_restore_current_thread restore_thread
;
1708 switch_to_thread (tp
);
1710 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1712 displaced_step_prepare_status status
=
1713 tp
->inf
->top_target ()->displaced_step_prepare (tp
);
1715 if (status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
1717 if (debug_displaced
)
1718 fprintf_unfiltered (gdb_stdlog
,
1719 "displaced: failed to prepare (%s)",
1720 target_pid_to_str (tp
->ptid
).c_str ());
1722 return DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1724 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1726 /* Not enough displaced stepping resources available, defer this
1727 request by placing it the queue. */
1729 if (debug_displaced
)
1730 fprintf_unfiltered (gdb_stdlog
,
1731 "displaced: not enough resources available, "
1732 "deferring step of %s\n",
1733 target_pid_to_str (tp
->ptid
).c_str ());
1735 global_thread_step_over_chain_enqueue (tp
);
1736 tp
->inf
->displaced_step_state
.unavailable
= true;
1738 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1741 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1743 // FIXME: Should probably replicated in the arch implementation now.
1745 // if (breakpoint_in_range_p (aspace, copy, len))
1747 // /* There's a breakpoint set in the scratch pad location range
1748 // (which is usually around the entry point). We'd either
1749 // install it before resuming, which would overwrite/corrupt the
1750 // scratch pad, or if it was already inserted, this displaced
1751 // step would overwrite it. The latter is OK in the sense that
1752 // we already assume that no thread is going to execute the code
1753 // in the scratch pad range (after initial startup) anyway, but
1754 // the former is unacceptable. Simply punt and fallback to
1755 // stepping over this breakpoint in-line. */
1756 // if (debug_displaced)
1758 // fprintf_unfiltered (gdb_stdlog,
1759 // "displaced: breakpoint set in scratch pad. "
1760 // "Stepping over breakpoint in-line instead.\n");
1763 // gdb_assert (false);
1764 // gdbarch_displaced_step_release_location (gdbarch, copy);
1769 /* Save the information we need to fix things up if the step
1771 thread_disp_step_state
->set (gdbarch
);
1773 // FIXME: get it from _prepare?
1774 CORE_ADDR displaced_pc
= 0;
1776 if (debug_displaced
)
1777 fprintf_unfiltered (gdb_stdlog
,
1778 "displaced: prepared successfully thread=%s, "
1779 "original_pc=%s, displaced_pc=%s\n",
1780 target_pid_to_str (tp
->ptid
).c_str (),
1781 paddress (gdbarch
, original_pc
),
1782 paddress (gdbarch
, displaced_pc
));
1784 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1787 /* Wrapper for displaced_step_prepare_throw that disabled further
1788 attempts at displaced stepping if we get a memory error. */
1790 static displaced_step_prepare_status
1791 displaced_step_prepare (thread_info
*thread
)
1793 displaced_step_prepare_status status
1794 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1798 status
= displaced_step_prepare_throw (thread
);
1800 catch (const gdb_exception_error
&ex
)
1802 struct displaced_step_inferior_state
*displaced_state
;
1804 if (ex
.error
!= MEMORY_ERROR
1805 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1808 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1811 /* Be verbose if "set displaced-stepping" is "on", silent if
1813 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1815 warning (_("disabling displaced stepping: %s"),
1819 /* Disable further displaced stepping attempts. */
1821 = get_displaced_stepping_state (thread
->inf
);
1822 displaced_state
->failed_before
= 1;
1828 /* If we displaced stepped an instruction successfully, adjust
1829 registers and memory to yield the same effect the instruction would
1830 have had if we had executed it at its original address, and return
1831 1. If the instruction didn't complete, relocate the PC and return
1832 -1. If the thread wasn't displaced stepping, return 0. */
1835 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1837 displaced_step_thread_state
*displaced
1838 = get_displaced_stepping_state (event_thread
);
1840 /* Was this thread performing a displaced step? */
1841 if (!displaced
->in_progress ())
1844 displaced_step_reset_cleanup
cleanup (displaced
);
1846 /* Fixup may need to read memory/registers. Switch to the thread
1847 that we're fixing up. Also, target_stopped_by_watchpoint checks
1848 the current thread, and displaced_step_restore performs ptid-dependent
1849 memory accesses using current_inferior() and current_top_target(). */
1850 switch_to_thread (event_thread
);
1852 /* Do the fixup, and release the resources acquired to do the displaced
1854 displaced_step_finish_status finish_status
=
1855 event_thread
->inf
->top_target ()->displaced_step_finish (event_thread
,
1858 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1864 /* Data to be passed around while handling an event. This data is
1865 discarded between events. */
1866 struct execution_control_state
1868 process_stratum_target
*target
;
1870 /* The thread that got the event, if this was a thread event; NULL
1872 struct thread_info
*event_thread
;
1874 struct target_waitstatus ws
;
1875 int stop_func_filled_in
;
1876 CORE_ADDR stop_func_start
;
1877 CORE_ADDR stop_func_end
;
1878 const char *stop_func_name
;
1881 /* True if the event thread hit the single-step breakpoint of
1882 another thread. Thus the event doesn't cause a stop, the thread
1883 needs to be single-stepped past the single-step breakpoint before
1884 we can switch back to the original stepping thread. */
1885 int hit_singlestep_breakpoint
;
1888 /* Clear ECS and set it to point at TP. */
1891 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1893 memset (ecs
, 0, sizeof (*ecs
));
1894 ecs
->event_thread
= tp
;
1895 ecs
->ptid
= tp
->ptid
;
1898 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1899 static void prepare_to_wait (struct execution_control_state
*ecs
);
1900 static int keep_going_stepped_thread (struct thread_info
*tp
);
1901 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1903 /* Are there any pending step-over requests? If so, run all we can
1904 now and return true. Otherwise, return false. */
1907 start_step_over (void)
1909 struct thread_info
*tp
, *next
;
1912 /* Don't start a new step-over if we already have an in-line
1913 step-over operation ongoing. */
1914 if (step_over_info_valid_p ())
1917 /* Steal the global thread step over chain. */
1918 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1919 global_thread_step_over_chain_head
= NULL
;
1922 fprintf_unfiltered (gdb_stdlog
,
1923 "infrun: stealing list of %d threads to step from global queue\n",
1924 thread_step_over_chain_length (threads_to_step
));
1926 for (inferior
*inf
: all_inferiors ())
1927 inf
->displaced_step_state
.unavailable
= false;
1929 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1931 struct execution_control_state ecss
;
1932 struct execution_control_state
*ecs
= &ecss
;
1933 step_over_what step_what
;
1934 int must_be_in_line
;
1936 gdb_assert (!tp
->stop_requested
);
1938 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1940 step_what
= thread_still_needs_step_over (tp
);
1941 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1942 || ((step_what
& STEP_OVER_BREAKPOINT
)
1943 && !use_displaced_stepping (tp
)));
1945 /* We currently stop all threads of all processes to step-over
1946 in-line. If we need to start a new in-line step-over, let
1947 any pending displaced steps finish first. */
1948 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1951 thread_step_over_chain_remove (&threads_to_step
, tp
);
1953 if (tp
->control
.trap_expected
1957 internal_error (__FILE__
, __LINE__
,
1958 "[%s] has inconsistent state: "
1959 "trap_expected=%d, resumed=%d, executing=%d\n",
1960 target_pid_to_str (tp
->ptid
).c_str (),
1961 tp
->control
.trap_expected
,
1966 infrun_log_debug ("resuming [%s] for step-over",
1967 target_pid_to_str (tp
->ptid
).c_str ());
1969 /* keep_going_pass_signal skips the step-over if the breakpoint
1970 is no longer inserted. In all-stop, we want to keep looking
1971 for a thread that needs a step-over instead of resuming TP,
1972 because we wouldn't be able to resume anything else until the
1973 target stops again. In non-stop, the resume always resumes
1974 only TP, so it's OK to let the thread resume freely. */
1975 if (!target_is_non_stop_p () && !step_what
)
1978 if (tp
->inf
->displaced_step_state
.unavailable
)
1980 global_thread_step_over_chain_enqueue (tp
);
1984 switch_to_thread (tp
);
1985 reset_ecs (ecs
, tp
);
1986 keep_going_pass_signal (ecs
);
1988 if (!ecs
->wait_some_more
)
1989 error (_("Command aborted."));
1991 /* If the thread's step over could not be initiated, it was re-added
1992 to the global step over chain. */
1995 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
1996 target_pid_to_str (tp
->ptid
).c_str ());
1997 gdb_assert (!thread_is_in_step_over_chain (tp
));
2001 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
2002 target_pid_to_str (tp
->ptid
).c_str ());
2003 gdb_assert (thread_is_in_step_over_chain (tp
));
2007 /* If we started a new in-line step-over, we're done. */
2008 if (step_over_info_valid_p ())
2010 gdb_assert (tp
->control
.trap_expected
);
2015 if (!target_is_non_stop_p ())
2017 /* On all-stop, shouldn't have resumed unless we needed a
2019 gdb_assert (tp
->control
.trap_expected
2020 || tp
->step_after_step_resume_breakpoint
);
2022 /* With remote targets (at least), in all-stop, we can't
2023 issue any further remote commands until the program stops
2029 /* Either the thread no longer needed a step-over, or a new
2030 displaced stepping sequence started. Even in the latter
2031 case, continue looking. Maybe we can also start another
2032 displaced step on a thread of other process. */
2035 /* If there are threads left in the THREADS_TO_STEP list, but we have
2036 detected that we can't start anything more, put back these threads
2037 in the global list. */
2038 if (threads_to_step
== NULL
)
2041 fprintf_unfiltered (gdb_stdlog
,
2042 "infrun: step-over queue now empty\n");
2047 fprintf_unfiltered (gdb_stdlog
,
2048 "infrun: putting back %d threads to step in global queue\n",
2049 thread_step_over_chain_length (threads_to_step
));
2050 while (threads_to_step
!= nullptr)
2052 thread_info
*thread
= threads_to_step
;
2054 /* Remove from that list. */
2055 thread_step_over_chain_remove (&threads_to_step
, thread
);
2057 /* Add to global list. */
2058 global_thread_step_over_chain_enqueue (thread
);
2066 /* Update global variables holding ptids to hold NEW_PTID if they were
2067 holding OLD_PTID. */
2069 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2071 if (inferior_ptid
== old_ptid
)
2072 inferior_ptid
= new_ptid
;
2077 static const char schedlock_off
[] = "off";
2078 static const char schedlock_on
[] = "on";
2079 static const char schedlock_step
[] = "step";
2080 static const char schedlock_replay
[] = "replay";
2081 static const char *const scheduler_enums
[] = {
2088 static const char *scheduler_mode
= schedlock_replay
;
2090 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2091 struct cmd_list_element
*c
, const char *value
)
2093 fprintf_filtered (file
,
2094 _("Mode for locking scheduler "
2095 "during execution is \"%s\".\n"),
2100 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2102 if (!target_can_lock_scheduler
)
2104 scheduler_mode
= schedlock_off
;
2105 error (_("Target '%s' cannot support this command."), target_shortname
);
2109 /* True if execution commands resume all threads of all processes by
2110 default; otherwise, resume only threads of the current inferior
2112 bool sched_multi
= false;
2114 /* Try to setup for software single stepping over the specified location.
2115 Return 1 if target_resume() should use hardware single step.
2117 GDBARCH the current gdbarch.
2118 PC the location to step over. */
2121 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2125 if (execution_direction
== EXEC_FORWARD
2126 && gdbarch_software_single_step_p (gdbarch
))
2127 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2135 user_visible_resume_ptid (int step
)
2141 /* With non-stop mode on, threads are always handled
2143 resume_ptid
= inferior_ptid
;
2145 else if ((scheduler_mode
== schedlock_on
)
2146 || (scheduler_mode
== schedlock_step
&& step
))
2148 /* User-settable 'scheduler' mode requires solo thread
2150 resume_ptid
= inferior_ptid
;
2152 else if ((scheduler_mode
== schedlock_replay
)
2153 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2155 /* User-settable 'scheduler' mode requires solo thread resume in replay
2157 resume_ptid
= inferior_ptid
;
2159 else if (!sched_multi
&& target_supports_multi_process ())
2161 /* Resume all threads of the current process (and none of other
2163 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2167 /* Resume all threads of all processes. */
2168 resume_ptid
= RESUME_ALL
;
2176 process_stratum_target
*
2177 user_visible_resume_target (ptid_t resume_ptid
)
2179 return (resume_ptid
== minus_one_ptid
&& sched_multi
2181 : current_inferior ()->process_target ());
2184 /* Return a ptid representing the set of threads that we will resume,
2185 in the perspective of the target, assuming run control handling
2186 does not require leaving some threads stopped (e.g., stepping past
2187 breakpoint). USER_STEP indicates whether we're about to start the
2188 target for a stepping command. */
2191 internal_resume_ptid (int user_step
)
2193 /* In non-stop, we always control threads individually. Note that
2194 the target may always work in non-stop mode even with "set
2195 non-stop off", in which case user_visible_resume_ptid could
2196 return a wildcard ptid. */
2197 if (target_is_non_stop_p ())
2198 return inferior_ptid
;
2200 return user_visible_resume_ptid (user_step
);
2203 /* Wrapper for target_resume, that handles infrun-specific
2207 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2209 struct thread_info
*tp
= inferior_thread ();
2211 gdb_assert (!tp
->stop_requested
);
2213 /* Install inferior's terminal modes. */
2214 target_terminal::inferior ();
2216 /* Avoid confusing the next resume, if the next stop/resume
2217 happens to apply to another thread. */
2218 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2220 /* Advise target which signals may be handled silently.
2222 If we have removed breakpoints because we are stepping over one
2223 in-line (in any thread), we need to receive all signals to avoid
2224 accidentally skipping a breakpoint during execution of a signal
2227 Likewise if we're displaced stepping, otherwise a trap for a
2228 breakpoint in a signal handler might be confused with the
2229 displaced step finishing. We don't make the displaced_step_fixup
2230 step distinguish the cases instead, because:
2232 - a backtrace while stopped in the signal handler would show the
2233 scratch pad as frame older than the signal handler, instead of
2234 the real mainline code.
2236 - when the thread is later resumed, the signal handler would
2237 return to the scratch pad area, which would no longer be
2239 if (step_over_info_valid_p ()
2240 || displaced_step_in_progress (tp
->inf
))
2241 target_pass_signals ({});
2243 target_pass_signals (signal_pass
);
2245 target_resume (resume_ptid
, step
, sig
);
2247 target_commit_resume ();
2249 if (target_can_async_p ())
2253 /* Resume the inferior. SIG is the signal to give the inferior
2254 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2255 call 'resume', which handles exceptions. */
2258 resume_1 (enum gdb_signal sig
)
2260 struct regcache
*regcache
= get_current_regcache ();
2261 struct gdbarch
*gdbarch
= regcache
->arch ();
2262 struct thread_info
*tp
= inferior_thread ();
2263 const address_space
*aspace
= regcache
->aspace ();
2265 /* This represents the user's step vs continue request. When
2266 deciding whether "set scheduler-locking step" applies, it's the
2267 user's intention that counts. */
2268 const int user_step
= tp
->control
.stepping_command
;
2269 /* This represents what we'll actually request the target to do.
2270 This can decay from a step to a continue, if e.g., we need to
2271 implement single-stepping with breakpoints (software
2275 gdb_assert (!tp
->stop_requested
);
2276 gdb_assert (!thread_is_in_step_over_chain (tp
));
2278 if (tp
->suspend
.waitstatus_pending_p
)
2281 ("thread %s has pending wait "
2282 "status %s (currently_stepping=%d).",
2283 target_pid_to_str (tp
->ptid
).c_str (),
2284 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2285 currently_stepping (tp
));
2287 tp
->inf
->process_target ()->threads_executing
= true;
2290 /* FIXME: What should we do if we are supposed to resume this
2291 thread with a signal? Maybe we should maintain a queue of
2292 pending signals to deliver. */
2293 if (sig
!= GDB_SIGNAL_0
)
2295 warning (_("Couldn't deliver signal %s to %s."),
2296 gdb_signal_to_name (sig
),
2297 target_pid_to_str (tp
->ptid
).c_str ());
2300 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2302 if (target_can_async_p ())
2305 /* Tell the event loop we have an event to process. */
2306 mark_async_event_handler (infrun_async_inferior_event_token
);
2311 tp
->stepped_breakpoint
= 0;
2313 /* Depends on stepped_breakpoint. */
2314 step
= currently_stepping (tp
);
2316 if (current_inferior ()->waiting_for_vfork_done
)
2318 /* Don't try to single-step a vfork parent that is waiting for
2319 the child to get out of the shared memory region (by exec'ing
2320 or exiting). This is particularly important on software
2321 single-step archs, as the child process would trip on the
2322 software single step breakpoint inserted for the parent
2323 process. Since the parent will not actually execute any
2324 instruction until the child is out of the shared region (such
2325 are vfork's semantics), it is safe to simply continue it.
2326 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2327 the parent, and tell it to `keep_going', which automatically
2328 re-sets it stepping. */
2329 infrun_log_debug ("resume : clear step");
2333 CORE_ADDR pc
= regcache_read_pc (regcache
);
2335 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2336 "current thread [%s] at %s",
2337 step
, gdb_signal_to_symbol_string (sig
),
2338 tp
->control
.trap_expected
,
2339 target_pid_to_str (inferior_ptid
).c_str (),
2340 paddress (gdbarch
, pc
));
2342 /* Normally, by the time we reach `resume', the breakpoints are either
2343 removed or inserted, as appropriate. The exception is if we're sitting
2344 at a permanent breakpoint; we need to step over it, but permanent
2345 breakpoints can't be removed. So we have to test for it here. */
2346 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2348 if (sig
!= GDB_SIGNAL_0
)
2350 /* We have a signal to pass to the inferior. The resume
2351 may, or may not take us to the signal handler. If this
2352 is a step, we'll need to stop in the signal handler, if
2353 there's one, (if the target supports stepping into
2354 handlers), or in the next mainline instruction, if
2355 there's no handler. If this is a continue, we need to be
2356 sure to run the handler with all breakpoints inserted.
2357 In all cases, set a breakpoint at the current address
2358 (where the handler returns to), and once that breakpoint
2359 is hit, resume skipping the permanent breakpoint. If
2360 that breakpoint isn't hit, then we've stepped into the
2361 signal handler (or hit some other event). We'll delete
2362 the step-resume breakpoint then. */
2364 infrun_log_debug ("resume: skipping permanent breakpoint, "
2365 "deliver signal first");
2367 clear_step_over_info ();
2368 tp
->control
.trap_expected
= 0;
2370 if (tp
->control
.step_resume_breakpoint
== NULL
)
2372 /* Set a "high-priority" step-resume, as we don't want
2373 user breakpoints at PC to trigger (again) when this
2375 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2376 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2378 tp
->step_after_step_resume_breakpoint
= step
;
2381 insert_breakpoints ();
2385 /* There's no signal to pass, we can go ahead and skip the
2386 permanent breakpoint manually. */
2387 infrun_log_debug ("skipping permanent breakpoint");
2388 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2389 /* Update pc to reflect the new address from which we will
2390 execute instructions. */
2391 pc
= regcache_read_pc (regcache
);
2395 /* We've already advanced the PC, so the stepping part
2396 is done. Now we need to arrange for a trap to be
2397 reported to handle_inferior_event. Set a breakpoint
2398 at the current PC, and run to it. Don't update
2399 prev_pc, because if we end in
2400 switch_back_to_stepped_thread, we want the "expected
2401 thread advanced also" branch to be taken. IOW, we
2402 don't want this thread to step further from PC
2404 gdb_assert (!step_over_info_valid_p ());
2405 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2406 insert_breakpoints ();
2408 resume_ptid
= internal_resume_ptid (user_step
);
2409 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2416 /* If we have a breakpoint to step over, make sure to do a single
2417 step only. Same if we have software watchpoints. */
2418 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2419 tp
->control
.may_range_step
= 0;
2421 /* If displaced stepping is enabled, step over breakpoints by executing a
2422 copy of the instruction at a different address.
2424 We can't use displaced stepping when we have a signal to deliver;
2425 the comments for displaced_step_prepare explain why. The
2426 comments in the handle_inferior event for dealing with 'random
2427 signals' explain what we do instead.
2429 We can't use displaced stepping when we are waiting for vfork_done
2430 event, displaced stepping breaks the vfork child similarly as single
2431 step software breakpoint. */
2432 if (tp
->control
.trap_expected
2433 && use_displaced_stepping (tp
)
2434 && !step_over_info_valid_p ()
2435 && sig
== GDB_SIGNAL_0
2436 && !current_inferior ()->waiting_for_vfork_done
)
2438 displaced_step_prepare_status prepare_status
2439 = displaced_step_prepare (tp
);
2441 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2443 infrun_log_debug ("Got placed in step-over queue");
2445 tp
->control
.trap_expected
= 0;
2448 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2450 /* Fallback to stepping over the breakpoint in-line. */
2452 if (target_is_non_stop_p ())
2453 stop_all_threads ();
2455 set_step_over_info (regcache
->aspace (),
2456 regcache_read_pc (regcache
), 0, tp
->global_num
);
2458 step
= maybe_software_singlestep (gdbarch
, pc
);
2460 insert_breakpoints ();
2462 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2464 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2467 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2470 /* Do we need to do it the hard way, w/temp breakpoints? */
2472 step
= maybe_software_singlestep (gdbarch
, pc
);
2474 /* Currently, our software single-step implementation leads to different
2475 results than hardware single-stepping in one situation: when stepping
2476 into delivering a signal which has an associated signal handler,
2477 hardware single-step will stop at the first instruction of the handler,
2478 while software single-step will simply skip execution of the handler.
2480 For now, this difference in behavior is accepted since there is no
2481 easy way to actually implement single-stepping into a signal handler
2482 without kernel support.
2484 However, there is one scenario where this difference leads to follow-on
2485 problems: if we're stepping off a breakpoint by removing all breakpoints
2486 and then single-stepping. In this case, the software single-step
2487 behavior means that even if there is a *breakpoint* in the signal
2488 handler, GDB still would not stop.
2490 Fortunately, we can at least fix this particular issue. We detect
2491 here the case where we are about to deliver a signal while software
2492 single-stepping with breakpoints removed. In this situation, we
2493 revert the decisions to remove all breakpoints and insert single-
2494 step breakpoints, and instead we install a step-resume breakpoint
2495 at the current address, deliver the signal without stepping, and
2496 once we arrive back at the step-resume breakpoint, actually step
2497 over the breakpoint we originally wanted to step over. */
2498 if (thread_has_single_step_breakpoints_set (tp
)
2499 && sig
!= GDB_SIGNAL_0
2500 && step_over_info_valid_p ())
2502 /* If we have nested signals or a pending signal is delivered
2503 immediately after a handler returns, might already have
2504 a step-resume breakpoint set on the earlier handler. We cannot
2505 set another step-resume breakpoint; just continue on until the
2506 original breakpoint is hit. */
2507 if (tp
->control
.step_resume_breakpoint
== NULL
)
2509 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2510 tp
->step_after_step_resume_breakpoint
= 1;
2513 delete_single_step_breakpoints (tp
);
2515 clear_step_over_info ();
2516 tp
->control
.trap_expected
= 0;
2518 insert_breakpoints ();
2521 /* If STEP is set, it's a request to use hardware stepping
2522 facilities. But in that case, we should never
2523 use singlestep breakpoint. */
2524 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2526 /* Decide the set of threads to ask the target to resume. */
2527 if (tp
->control
.trap_expected
)
2529 /* We're allowing a thread to run past a breakpoint it has
2530 hit, either by single-stepping the thread with the breakpoint
2531 removed, or by displaced stepping, with the breakpoint inserted.
2532 In the former case, we need to single-step only this thread,
2533 and keep others stopped, as they can miss this breakpoint if
2534 allowed to run. That's not really a problem for displaced
2535 stepping, but, we still keep other threads stopped, in case
2536 another thread is also stopped for a breakpoint waiting for
2537 its turn in the displaced stepping queue. */
2538 resume_ptid
= inferior_ptid
;
2541 resume_ptid
= internal_resume_ptid (user_step
);
2543 if (execution_direction
!= EXEC_REVERSE
2544 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2546 /* There are two cases where we currently need to step a
2547 breakpoint instruction when we have a signal to deliver:
2549 - See handle_signal_stop where we handle random signals that
2550 could take out us out of the stepping range. Normally, in
2551 that case we end up continuing (instead of stepping) over the
2552 signal handler with a breakpoint at PC, but there are cases
2553 where we should _always_ single-step, even if we have a
2554 step-resume breakpoint, like when a software watchpoint is
2555 set. Assuming single-stepping and delivering a signal at the
2556 same time would takes us to the signal handler, then we could
2557 have removed the breakpoint at PC to step over it. However,
2558 some hardware step targets (like e.g., Mac OS) can't step
2559 into signal handlers, and for those, we need to leave the
2560 breakpoint at PC inserted, as otherwise if the handler
2561 recurses and executes PC again, it'll miss the breakpoint.
2562 So we leave the breakpoint inserted anyway, but we need to
2563 record that we tried to step a breakpoint instruction, so
2564 that adjust_pc_after_break doesn't end up confused.
2566 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2567 in one thread after another thread that was stepping had been
2568 momentarily paused for a step-over. When we re-resume the
2569 stepping thread, it may be resumed from that address with a
2570 breakpoint that hasn't trapped yet. Seen with
2571 gdb.threads/non-stop-fair-events.exp, on targets that don't
2572 do displaced stepping. */
2574 infrun_log_debug ("resume: [%s] stepped breakpoint",
2575 target_pid_to_str (tp
->ptid
).c_str ());
2577 tp
->stepped_breakpoint
= 1;
2579 /* Most targets can step a breakpoint instruction, thus
2580 executing it normally. But if this one cannot, just
2581 continue and we will hit it anyway. */
2582 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2587 && tp
->control
.trap_expected
2588 && use_displaced_stepping (tp
)
2589 && !step_over_info_valid_p ())
2591 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2592 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2593 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2596 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2597 paddress (resume_gdbarch
, actual_pc
));
2598 read_memory (actual_pc
, buf
, sizeof (buf
));
2599 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2602 if (tp
->control
.may_range_step
)
2604 /* If we're resuming a thread with the PC out of the step
2605 range, then we're doing some nested/finer run control
2606 operation, like stepping the thread out of the dynamic
2607 linker or the displaced stepping scratch pad. We
2608 shouldn't have allowed a range step then. */
2609 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2612 do_target_resume (resume_ptid
, step
, sig
);
2616 /* Resume the inferior. SIG is the signal to give the inferior
2617 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2618 rolls back state on error. */
2621 resume (gdb_signal sig
)
2627 catch (const gdb_exception
&ex
)
2629 /* If resuming is being aborted for any reason, delete any
2630 single-step breakpoint resume_1 may have created, to avoid
2631 confusing the following resumption, and to avoid leaving
2632 single-step breakpoints perturbing other threads, in case
2633 we're running in non-stop mode. */
2634 if (inferior_ptid
!= null_ptid
)
2635 delete_single_step_breakpoints (inferior_thread ());
2645 /* Counter that tracks number of user visible stops. This can be used
2646 to tell whether a command has proceeded the inferior past the
2647 current location. This allows e.g., inferior function calls in
2648 breakpoint commands to not interrupt the command list. When the
2649 call finishes successfully, the inferior is standing at the same
2650 breakpoint as if nothing happened (and so we don't call
2652 static ULONGEST current_stop_id
;
2659 return current_stop_id
;
2662 /* Called when we report a user visible stop. */
2670 /* Clear out all variables saying what to do when inferior is continued.
2671 First do this, then set the ones you want, then call `proceed'. */
2674 clear_proceed_status_thread (struct thread_info
*tp
)
2676 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2678 /* If we're starting a new sequence, then the previous finished
2679 single-step is no longer relevant. */
2680 if (tp
->suspend
.waitstatus_pending_p
)
2682 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2684 infrun_log_debug ("pending event of %s was a finished step. "
2686 target_pid_to_str (tp
->ptid
).c_str ());
2688 tp
->suspend
.waitstatus_pending_p
= 0;
2689 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2694 ("thread %s has pending wait status %s (currently_stepping=%d).",
2695 target_pid_to_str (tp
->ptid
).c_str (),
2696 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2697 currently_stepping (tp
));
2701 /* If this signal should not be seen by program, give it zero.
2702 Used for debugging signals. */
2703 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2704 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2706 delete tp
->thread_fsm
;
2707 tp
->thread_fsm
= NULL
;
2709 tp
->control
.trap_expected
= 0;
2710 tp
->control
.step_range_start
= 0;
2711 tp
->control
.step_range_end
= 0;
2712 tp
->control
.may_range_step
= 0;
2713 tp
->control
.step_frame_id
= null_frame_id
;
2714 tp
->control
.step_stack_frame_id
= null_frame_id
;
2715 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2716 tp
->control
.step_start_function
= NULL
;
2717 tp
->stop_requested
= 0;
2719 tp
->control
.stop_step
= 0;
2721 tp
->control
.proceed_to_finish
= 0;
2723 tp
->control
.stepping_command
= 0;
2725 /* Discard any remaining commands or status from previous stop. */
2726 bpstat_clear (&tp
->control
.stop_bpstat
);
2730 clear_proceed_status (int step
)
2732 /* With scheduler-locking replay, stop replaying other threads if we're
2733 not replaying the user-visible resume ptid.
2735 This is a convenience feature to not require the user to explicitly
2736 stop replaying the other threads. We're assuming that the user's
2737 intent is to resume tracing the recorded process. */
2738 if (!non_stop
&& scheduler_mode
== schedlock_replay
2739 && target_record_is_replaying (minus_one_ptid
)
2740 && !target_record_will_replay (user_visible_resume_ptid (step
),
2741 execution_direction
))
2742 target_record_stop_replaying ();
2744 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2746 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2747 process_stratum_target
*resume_target
2748 = user_visible_resume_target (resume_ptid
);
2750 /* In all-stop mode, delete the per-thread status of all threads
2751 we're about to resume, implicitly and explicitly. */
2752 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2753 clear_proceed_status_thread (tp
);
2756 if (inferior_ptid
!= null_ptid
)
2758 struct inferior
*inferior
;
2762 /* If in non-stop mode, only delete the per-thread status of
2763 the current thread. */
2764 clear_proceed_status_thread (inferior_thread ());
2767 inferior
= current_inferior ();
2768 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2771 gdb::observers::about_to_proceed
.notify ();
2774 /* Returns true if TP is still stopped at a breakpoint that needs
2775 stepping-over in order to make progress. If the breakpoint is gone
2776 meanwhile, we can skip the whole step-over dance. */
2779 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2781 if (tp
->stepping_over_breakpoint
)
2783 struct regcache
*regcache
= get_thread_regcache (tp
);
2785 if (breakpoint_here_p (regcache
->aspace (),
2786 regcache_read_pc (regcache
))
2787 == ordinary_breakpoint_here
)
2790 tp
->stepping_over_breakpoint
= 0;
2796 /* Check whether thread TP still needs to start a step-over in order
2797 to make progress when resumed. Returns an bitwise or of enum
2798 step_over_what bits, indicating what needs to be stepped over. */
2800 static step_over_what
2801 thread_still_needs_step_over (struct thread_info
*tp
)
2803 step_over_what what
= 0;
2805 if (thread_still_needs_step_over_bp (tp
))
2806 what
|= STEP_OVER_BREAKPOINT
;
2808 if (tp
->stepping_over_watchpoint
2809 && !target_have_steppable_watchpoint
)
2810 what
|= STEP_OVER_WATCHPOINT
;
2815 /* Returns true if scheduler locking applies. STEP indicates whether
2816 we're about to do a step/next-like command to a thread. */
2819 schedlock_applies (struct thread_info
*tp
)
2821 return (scheduler_mode
== schedlock_on
2822 || (scheduler_mode
== schedlock_step
2823 && tp
->control
.stepping_command
)
2824 || (scheduler_mode
== schedlock_replay
2825 && target_record_will_replay (minus_one_ptid
,
2826 execution_direction
)));
2829 /* Calls target_commit_resume on all targets. */
2832 commit_resume_all_targets ()
2834 scoped_restore_current_thread restore_thread
;
2836 /* Map between process_target and a representative inferior. This
2837 is to avoid committing a resume in the same target more than
2838 once. Resumptions must be idempotent, so this is an
2840 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2842 for (inferior
*inf
: all_non_exited_inferiors ())
2843 if (inf
->has_execution ())
2844 conn_inf
[inf
->process_target ()] = inf
;
2846 for (const auto &ci
: conn_inf
)
2848 inferior
*inf
= ci
.second
;
2849 switch_to_inferior_no_thread (inf
);
2850 target_commit_resume ();
2854 /* Check that all the targets we're about to resume are in non-stop
2855 mode. Ideally, we'd only care whether all targets support
2856 target-async, but we're not there yet. E.g., stop_all_threads
2857 doesn't know how to handle all-stop targets. Also, the remote
2858 protocol in all-stop mode is synchronous, irrespective of
2859 target-async, which means that things like a breakpoint re-set
2860 triggered by one target would try to read memory from all targets
2864 check_multi_target_resumption (process_stratum_target
*resume_target
)
2866 if (!non_stop
&& resume_target
== nullptr)
2868 scoped_restore_current_thread restore_thread
;
2870 /* This is used to track whether we're resuming more than one
2872 process_stratum_target
*first_connection
= nullptr;
2874 /* The first inferior we see with a target that does not work in
2875 always-non-stop mode. */
2876 inferior
*first_not_non_stop
= nullptr;
2878 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2880 switch_to_inferior_no_thread (inf
);
2882 if (!target_has_execution
)
2885 process_stratum_target
*proc_target
2886 = current_inferior ()->process_target();
2888 if (!target_is_non_stop_p ())
2889 first_not_non_stop
= inf
;
2891 if (first_connection
== nullptr)
2892 first_connection
= proc_target
;
2893 else if (first_connection
!= proc_target
2894 && first_not_non_stop
!= nullptr)
2896 switch_to_inferior_no_thread (first_not_non_stop
);
2898 proc_target
= current_inferior ()->process_target();
2900 error (_("Connection %d (%s) does not support "
2901 "multi-target resumption."),
2902 proc_target
->connection_number
,
2903 make_target_connection_string (proc_target
).c_str ());
2909 /* Basic routine for continuing the program in various fashions.
2911 ADDR is the address to resume at, or -1 for resume where stopped.
2912 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2913 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2915 You should call clear_proceed_status before calling proceed. */
2918 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2920 struct regcache
*regcache
;
2921 struct gdbarch
*gdbarch
;
2923 struct execution_control_state ecss
;
2924 struct execution_control_state
*ecs
= &ecss
;
2927 /* If we're stopped at a fork/vfork, follow the branch set by the
2928 "set follow-fork-mode" command; otherwise, we'll just proceed
2929 resuming the current thread. */
2930 if (!follow_fork ())
2932 /* The target for some reason decided not to resume. */
2934 if (target_can_async_p ())
2935 inferior_event_handler (INF_EXEC_COMPLETE
);
2939 /* We'll update this if & when we switch to a new thread. */
2940 previous_inferior_ptid
= inferior_ptid
;
2942 regcache
= get_current_regcache ();
2943 gdbarch
= regcache
->arch ();
2944 const address_space
*aspace
= regcache
->aspace ();
2946 pc
= regcache_read_pc_protected (regcache
);
2948 thread_info
*cur_thr
= inferior_thread ();
2950 /* Fill in with reasonable starting values. */
2951 init_thread_stepping_state (cur_thr
);
2953 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2956 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2957 process_stratum_target
*resume_target
2958 = user_visible_resume_target (resume_ptid
);
2960 check_multi_target_resumption (resume_target
);
2962 if (addr
== (CORE_ADDR
) -1)
2964 if (pc
== cur_thr
->suspend
.stop_pc
2965 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2966 && execution_direction
!= EXEC_REVERSE
)
2967 /* There is a breakpoint at the address we will resume at,
2968 step one instruction before inserting breakpoints so that
2969 we do not stop right away (and report a second hit at this
2972 Note, we don't do this in reverse, because we won't
2973 actually be executing the breakpoint insn anyway.
2974 We'll be (un-)executing the previous instruction. */
2975 cur_thr
->stepping_over_breakpoint
= 1;
2976 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2977 && gdbarch_single_step_through_delay (gdbarch
,
2978 get_current_frame ()))
2979 /* We stepped onto an instruction that needs to be stepped
2980 again before re-inserting the breakpoint, do so. */
2981 cur_thr
->stepping_over_breakpoint
= 1;
2985 regcache_write_pc (regcache
, addr
);
2988 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2989 cur_thr
->suspend
.stop_signal
= siggnal
;
2991 /* If an exception is thrown from this point on, make sure to
2992 propagate GDB's knowledge of the executing state to the
2993 frontend/user running state. */
2994 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2996 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2997 threads (e.g., we might need to set threads stepping over
2998 breakpoints first), from the user/frontend's point of view, all
2999 threads in RESUME_PTID are now running. Unless we're calling an
3000 inferior function, as in that case we pretend the inferior
3001 doesn't run at all. */
3002 if (!cur_thr
->control
.in_infcall
)
3003 set_running (resume_target
, resume_ptid
, true);
3005 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3006 gdb_signal_to_symbol_string (siggnal
));
3008 annotate_starting ();
3010 /* Make sure that output from GDB appears before output from the
3012 gdb_flush (gdb_stdout
);
3014 /* Since we've marked the inferior running, give it the terminal. A
3015 QUIT/Ctrl-C from here on is forwarded to the target (which can
3016 still detect attempts to unblock a stuck connection with repeated
3017 Ctrl-C from within target_pass_ctrlc). */
3018 target_terminal::inferior ();
3020 /* In a multi-threaded task we may select another thread and
3021 then continue or step.
3023 But if a thread that we're resuming had stopped at a breakpoint,
3024 it will immediately cause another breakpoint stop without any
3025 execution (i.e. it will report a breakpoint hit incorrectly). So
3026 we must step over it first.
3028 Look for threads other than the current (TP) that reported a
3029 breakpoint hit and haven't been resumed yet since. */
3031 /* If scheduler locking applies, we can avoid iterating over all
3033 if (!non_stop
&& !schedlock_applies (cur_thr
))
3035 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3038 switch_to_thread_no_regs (tp
);
3040 /* Ignore the current thread here. It's handled
3045 if (!thread_still_needs_step_over (tp
))
3048 gdb_assert (!thread_is_in_step_over_chain (tp
));
3050 infrun_log_debug ("need to step-over [%s] first",
3051 target_pid_to_str (tp
->ptid
).c_str ());
3053 global_thread_step_over_chain_enqueue (tp
);
3056 switch_to_thread (cur_thr
);
3059 /* Enqueue the current thread last, so that we move all other
3060 threads over their breakpoints first. */
3061 if (cur_thr
->stepping_over_breakpoint
)
3062 global_thread_step_over_chain_enqueue (cur_thr
);
3064 /* If the thread isn't started, we'll still need to set its prev_pc,
3065 so that switch_back_to_stepped_thread knows the thread hasn't
3066 advanced. Must do this before resuming any thread, as in
3067 all-stop/remote, once we resume we can't send any other packet
3068 until the target stops again. */
3069 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3072 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3074 started
= start_step_over ();
3076 if (step_over_info_valid_p ())
3078 /* Either this thread started a new in-line step over, or some
3079 other thread was already doing one. In either case, don't
3080 resume anything else until the step-over is finished. */
3082 else if (started
&& !target_is_non_stop_p ())
3084 /* A new displaced stepping sequence was started. In all-stop,
3085 we can't talk to the target anymore until it next stops. */
3087 else if (!non_stop
&& target_is_non_stop_p ())
3089 /* In all-stop, but the target is always in non-stop mode.
3090 Start all other threads that are implicitly resumed too. */
3091 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3094 switch_to_thread_no_regs (tp
);
3096 if (!tp
->inf
->has_execution ())
3098 infrun_log_debug ("[%s] target has no execution",
3099 target_pid_to_str (tp
->ptid
).c_str ());
3105 infrun_log_debug ("[%s] resumed",
3106 target_pid_to_str (tp
->ptid
).c_str ());
3107 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3111 if (thread_is_in_step_over_chain (tp
))
3113 infrun_log_debug ("[%s] needs step-over",
3114 target_pid_to_str (tp
->ptid
).c_str ());
3118 infrun_log_debug ("resuming %s",
3119 target_pid_to_str (tp
->ptid
).c_str ());
3121 reset_ecs (ecs
, tp
);
3122 switch_to_thread (tp
);
3123 keep_going_pass_signal (ecs
);
3124 if (!ecs
->wait_some_more
)
3125 error (_("Command aborted."));
3128 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3130 /* The thread wasn't started, and isn't queued, run it now. */
3131 reset_ecs (ecs
, cur_thr
);
3132 switch_to_thread (cur_thr
);
3133 keep_going_pass_signal (ecs
);
3134 if (!ecs
->wait_some_more
)
3135 error (_("Command aborted."));
3139 commit_resume_all_targets ();
3141 finish_state
.release ();
3143 /* If we've switched threads above, switch back to the previously
3144 current thread. We don't want the user to see a different
3146 switch_to_thread (cur_thr
);
3148 /* Tell the event loop to wait for it to stop. If the target
3149 supports asynchronous execution, it'll do this from within
3151 if (!target_can_async_p ())
3152 mark_async_event_handler (infrun_async_inferior_event_token
);
3156 /* Start remote-debugging of a machine over a serial link. */
3159 start_remote (int from_tty
)
3161 inferior
*inf
= current_inferior ();
3162 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3164 /* Always go on waiting for the target, regardless of the mode. */
3165 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3166 indicate to wait_for_inferior that a target should timeout if
3167 nothing is returned (instead of just blocking). Because of this,
3168 targets expecting an immediate response need to, internally, set
3169 things up so that the target_wait() is forced to eventually
3171 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3172 differentiate to its caller what the state of the target is after
3173 the initial open has been performed. Here we're assuming that
3174 the target has stopped. It should be possible to eventually have
3175 target_open() return to the caller an indication that the target
3176 is currently running and GDB state should be set to the same as
3177 for an async run. */
3178 wait_for_inferior (inf
);
3180 /* Now that the inferior has stopped, do any bookkeeping like
3181 loading shared libraries. We want to do this before normal_stop,
3182 so that the displayed frame is up to date. */
3183 post_create_inferior (current_top_target (), from_tty
);
3188 /* Initialize static vars when a new inferior begins. */
3191 init_wait_for_inferior (void)
3193 /* These are meaningless until the first time through wait_for_inferior. */
3195 breakpoint_init_inferior (inf_starting
);
3197 clear_proceed_status (0);
3199 nullify_last_target_wait_ptid ();
3201 previous_inferior_ptid
= inferior_ptid
;
3206 static void handle_inferior_event (struct execution_control_state
*ecs
);
3208 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3209 struct execution_control_state
*ecs
);
3210 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3211 struct execution_control_state
*ecs
);
3212 static void handle_signal_stop (struct execution_control_state
*ecs
);
3213 static void check_exception_resume (struct execution_control_state
*,
3214 struct frame_info
*);
3216 static void end_stepping_range (struct execution_control_state
*ecs
);
3217 static void stop_waiting (struct execution_control_state
*ecs
);
3218 static void keep_going (struct execution_control_state
*ecs
);
3219 static void process_event_stop_test (struct execution_control_state
*ecs
);
3220 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3222 /* This function is attached as a "thread_stop_requested" observer.
3223 Cleanup local state that assumed the PTID was to be resumed, and
3224 report the stop to the frontend. */
3227 infrun_thread_stop_requested (ptid_t ptid
)
3229 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3231 /* PTID was requested to stop. If the thread was already stopped,
3232 but the user/frontend doesn't know about that yet (e.g., the
3233 thread had been temporarily paused for some step-over), set up
3234 for reporting the stop now. */
3235 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3237 if (tp
->state
!= THREAD_RUNNING
)
3242 /* Remove matching threads from the step-over queue, so
3243 start_step_over doesn't try to resume them
3245 if (thread_is_in_step_over_chain (tp
))
3246 global_thread_step_over_chain_remove (tp
);
3248 /* If the thread is stopped, but the user/frontend doesn't
3249 know about that yet, queue a pending event, as if the
3250 thread had just stopped now. Unless the thread already had
3252 if (!tp
->suspend
.waitstatus_pending_p
)
3254 tp
->suspend
.waitstatus_pending_p
= 1;
3255 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3256 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3259 /* Clear the inline-frame state, since we're re-processing the
3261 clear_inline_frame_state (tp
);
3263 /* If this thread was paused because some other thread was
3264 doing an inline-step over, let that finish first. Once
3265 that happens, we'll restart all threads and consume pending
3266 stop events then. */
3267 if (step_over_info_valid_p ())
3270 /* Otherwise we can process the (new) pending event now. Set
3271 it so this pending event is considered by
3278 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3280 if (target_last_proc_target
== tp
->inf
->process_target ()
3281 && target_last_wait_ptid
== tp
->ptid
)
3282 nullify_last_target_wait_ptid ();
3285 /* Delete the step resume, single-step and longjmp/exception resume
3286 breakpoints of TP. */
3289 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3291 delete_step_resume_breakpoint (tp
);
3292 delete_exception_resume_breakpoint (tp
);
3293 delete_single_step_breakpoints (tp
);
3296 /* If the target still has execution, call FUNC for each thread that
3297 just stopped. In all-stop, that's all the non-exited threads; in
3298 non-stop, that's the current thread, only. */
3300 typedef void (*for_each_just_stopped_thread_callback_func
)
3301 (struct thread_info
*tp
);
3304 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3306 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3309 if (target_is_non_stop_p ())
3311 /* If in non-stop mode, only the current thread stopped. */
3312 func (inferior_thread ());
3316 /* In all-stop mode, all threads have stopped. */
3317 for (thread_info
*tp
: all_non_exited_threads ())
3322 /* Delete the step resume and longjmp/exception resume breakpoints of
3323 the threads that just stopped. */
3326 delete_just_stopped_threads_infrun_breakpoints (void)
3328 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3331 /* Delete the single-step breakpoints of the threads that just
3335 delete_just_stopped_threads_single_step_breakpoints (void)
3337 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3343 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3344 const struct target_waitstatus
*ws
)
3346 std::string status_string
= target_waitstatus_to_string (ws
);
3349 /* The text is split over several lines because it was getting too long.
3350 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3351 output as a unit; we want only one timestamp printed if debug_timestamp
3354 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3357 waiton_ptid
.tid ());
3358 if (waiton_ptid
.pid () != -1)
3359 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3360 stb
.printf (", status) =\n");
3361 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3365 target_pid_to_str (result_ptid
).c_str ());
3366 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3368 /* This uses %s in part to handle %'s in the text, but also to avoid
3369 a gcc error: the format attribute requires a string literal. */
3370 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3373 /* Select a thread at random, out of those which are resumed and have
3376 static struct thread_info
*
3377 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3381 auto has_event
= [&] (thread_info
*tp
)
3383 return (tp
->ptid
.matches (waiton_ptid
)
3385 && tp
->suspend
.waitstatus_pending_p
);
3388 /* First see how many events we have. Count only resumed threads
3389 that have an event pending. */
3390 for (thread_info
*tp
: inf
->non_exited_threads ())
3394 if (num_events
== 0)
3397 /* Now randomly pick a thread out of those that have had events. */
3398 int random_selector
= (int) ((num_events
* (double) rand ())
3399 / (RAND_MAX
+ 1.0));
3402 infrun_log_debug ("Found %d events, selecting #%d",
3403 num_events
, random_selector
);
3405 /* Select the Nth thread that has had an event. */
3406 for (thread_info
*tp
: inf
->non_exited_threads ())
3408 if (random_selector
-- == 0)
3411 gdb_assert_not_reached ("event thread not found");
3414 /* Wrapper for target_wait that first checks whether threads have
3415 pending statuses to report before actually asking the target for
3416 more events. INF is the inferior we're using to call target_wait
3420 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3421 target_waitstatus
*status
, int options
)
3424 struct thread_info
*tp
;
3426 /* We know that we are looking for an event in the target of inferior
3427 INF, but we don't know which thread the event might come from. As
3428 such we want to make sure that INFERIOR_PTID is reset so that none of
3429 the wait code relies on it - doing so is always a mistake. */
3430 switch_to_inferior_no_thread (inf
);
3432 /* First check if there is a resumed thread with a wait status
3434 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3436 tp
= random_pending_event_thread (inf
, ptid
);
3440 infrun_log_debug ("Waiting for specific thread %s.",
3441 target_pid_to_str (ptid
).c_str ());
3443 /* We have a specific thread to check. */
3444 tp
= find_thread_ptid (inf
, ptid
);
3445 gdb_assert (tp
!= NULL
);
3446 if (!tp
->suspend
.waitstatus_pending_p
)
3451 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3452 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3454 struct regcache
*regcache
= get_thread_regcache (tp
);
3455 struct gdbarch
*gdbarch
= regcache
->arch ();
3459 pc
= regcache_read_pc (regcache
);
3461 if (pc
!= tp
->suspend
.stop_pc
)
3463 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3464 target_pid_to_str (tp
->ptid
).c_str (),
3465 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3466 paddress (gdbarch
, pc
));
3469 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3471 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3472 target_pid_to_str (tp
->ptid
).c_str (),
3473 paddress (gdbarch
, pc
));
3480 infrun_log_debug ("pending event of %s cancelled.",
3481 target_pid_to_str (tp
->ptid
).c_str ());
3483 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3484 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3490 infrun_log_debug ("Using pending wait status %s for %s.",
3491 target_waitstatus_to_string
3492 (&tp
->suspend
.waitstatus
).c_str (),
3493 target_pid_to_str (tp
->ptid
).c_str ());
3495 /* Now that we've selected our final event LWP, un-adjust its PC
3496 if it was a software breakpoint (and the target doesn't
3497 always adjust the PC itself). */
3498 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3499 && !target_supports_stopped_by_sw_breakpoint ())
3501 struct regcache
*regcache
;
3502 struct gdbarch
*gdbarch
;
3505 regcache
= get_thread_regcache (tp
);
3506 gdbarch
= regcache
->arch ();
3508 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3513 pc
= regcache_read_pc (regcache
);
3514 regcache_write_pc (regcache
, pc
+ decr_pc
);
3518 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3519 *status
= tp
->suspend
.waitstatus
;
3520 tp
->suspend
.waitstatus_pending_p
= 0;
3522 /* Wake up the event loop again, until all pending events are
3524 if (target_is_async_p ())
3525 mark_async_event_handler (infrun_async_inferior_event_token
);
3529 /* But if we don't find one, we'll have to wait. */
3531 if (deprecated_target_wait_hook
)
3532 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3534 event_ptid
= target_wait (ptid
, status
, options
);
3539 /* Wrapper for target_wait that first checks whether threads have
3540 pending statuses to report before actually asking the target for
3541 more events. Polls for events from all inferiors/targets. */
3544 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3546 int num_inferiors
= 0;
3547 int random_selector
;
3549 /* For fairness, we pick the first inferior/target to poll at random
3550 out of all inferiors that may report events, and then continue
3551 polling the rest of the inferior list starting from that one in a
3552 circular fashion until the whole list is polled once. */
3554 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3556 return (inf
->process_target () != NULL
3557 && ptid_t (inf
->pid
).matches (wait_ptid
));
3560 /* First see how many matching inferiors we have. */
3561 for (inferior
*inf
: all_inferiors ())
3562 if (inferior_matches (inf
))
3565 if (num_inferiors
== 0)
3567 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3571 /* Now randomly pick an inferior out of those that matched. */
3572 random_selector
= (int)
3573 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3575 if (num_inferiors
> 1)
3576 infrun_log_debug ("Found %d inferiors, starting at #%d",
3577 num_inferiors
, random_selector
);
3579 /* Select the Nth inferior that matched. */
3581 inferior
*selected
= nullptr;
3583 for (inferior
*inf
: all_inferiors ())
3584 if (inferior_matches (inf
))
3585 if (random_selector
-- == 0)
3591 /* Now poll for events out of each of the matching inferior's
3592 targets, starting from the selected one. */
3594 auto do_wait
= [&] (inferior
*inf
)
3596 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3597 ecs
->target
= inf
->process_target ();
3598 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3601 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3602 here spuriously after the target is all stopped and we've already
3603 reported the stop to the user, polling for events. */
3604 scoped_restore_current_thread restore_thread
;
3606 int inf_num
= selected
->num
;
3607 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3608 if (inferior_matches (inf
))
3612 for (inferior
*inf
= inferior_list
;
3613 inf
!= NULL
&& inf
->num
< inf_num
;
3615 if (inferior_matches (inf
))
3619 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3623 /* Prepare and stabilize the inferior for detaching it. E.g.,
3624 detaching while a thread is displaced stepping is a recipe for
3625 crashing it, as nothing would readjust the PC out of the scratch
3629 prepare_for_detach (void)
3631 struct inferior
*inf
= current_inferior ();
3632 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3634 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3636 /* Is any thread of this process displaced stepping? If not,
3637 there's nothing else to do. */
3638 if (displaced_step_in_progress (inf
))
3641 infrun_log_debug ("displaced-stepping in-process while detaching");
3643 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3648 struct execution_control_state ecss
;
3649 struct execution_control_state
*ecs
;
3652 memset (ecs
, 0, sizeof (*ecs
));
3654 overlay_cache_invalid
= 1;
3655 /* Flush target cache before starting to handle each event.
3656 Target was running and cache could be stale. This is just a
3657 heuristic. Running threads may modify target memory, but we
3658 don't get any event. */
3659 target_dcache_invalidate ();
3661 do_target_wait (pid_ptid
, ecs
, 0);
3664 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3666 /* If an error happens while handling the event, propagate GDB's
3667 knowledge of the executing state to the frontend/user running
3669 scoped_finish_thread_state
finish_state (inf
->process_target (),
3672 /* Now figure out what to do with the result of the result. */
3673 handle_inferior_event (ecs
);
3675 /* No error, don't finish the state yet. */
3676 finish_state
.release ();
3678 /* Breakpoints and watchpoints are not installed on the target
3679 at this point, and signals are passed directly to the
3680 inferior, so this must mean the process is gone. */
3681 if (!ecs
->wait_some_more
)
3683 restore_detaching
.release ();
3684 error (_("Program exited while detaching"));
3688 restore_detaching
.release ();
3691 /* Wait for control to return from inferior to debugger.
3693 If inferior gets a signal, we may decide to start it up again
3694 instead of returning. That is why there is a loop in this function.
3695 When this function actually returns it means the inferior
3696 should be left stopped and GDB should read more commands. */
3699 wait_for_inferior (inferior
*inf
)
3701 infrun_log_debug ("wait_for_inferior ()");
3703 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3705 /* If an error happens while handling the event, propagate GDB's
3706 knowledge of the executing state to the frontend/user running
3708 scoped_finish_thread_state finish_state
3709 (inf
->process_target (), minus_one_ptid
);
3713 struct execution_control_state ecss
;
3714 struct execution_control_state
*ecs
= &ecss
;
3716 memset (ecs
, 0, sizeof (*ecs
));
3718 overlay_cache_invalid
= 1;
3720 /* Flush target cache before starting to handle each event.
3721 Target was running and cache could be stale. This is just a
3722 heuristic. Running threads may modify target memory, but we
3723 don't get any event. */
3724 target_dcache_invalidate ();
3726 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3727 ecs
->target
= inf
->process_target ();
3730 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3732 /* Now figure out what to do with the result of the result. */
3733 handle_inferior_event (ecs
);
3735 if (!ecs
->wait_some_more
)
3739 /* No error, don't finish the state yet. */
3740 finish_state
.release ();
3743 /* Cleanup that reinstalls the readline callback handler, if the
3744 target is running in the background. If while handling the target
3745 event something triggered a secondary prompt, like e.g., a
3746 pagination prompt, we'll have removed the callback handler (see
3747 gdb_readline_wrapper_line). Need to do this as we go back to the
3748 event loop, ready to process further input. Note this has no
3749 effect if the handler hasn't actually been removed, because calling
3750 rl_callback_handler_install resets the line buffer, thus losing
3754 reinstall_readline_callback_handler_cleanup ()
3756 struct ui
*ui
= current_ui
;
3760 /* We're not going back to the top level event loop yet. Don't
3761 install the readline callback, as it'd prep the terminal,
3762 readline-style (raw, noecho) (e.g., --batch). We'll install
3763 it the next time the prompt is displayed, when we're ready
3768 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3769 gdb_rl_callback_handler_reinstall ();
3772 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3773 that's just the event thread. In all-stop, that's all threads. */
3776 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3778 if (ecs
->event_thread
!= NULL
3779 && ecs
->event_thread
->thread_fsm
!= NULL
)
3780 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3784 for (thread_info
*thr
: all_non_exited_threads ())
3786 if (thr
->thread_fsm
== NULL
)
3788 if (thr
== ecs
->event_thread
)
3791 switch_to_thread (thr
);
3792 thr
->thread_fsm
->clean_up (thr
);
3795 if (ecs
->event_thread
!= NULL
)
3796 switch_to_thread (ecs
->event_thread
);
3800 /* Helper for all_uis_check_sync_execution_done that works on the
3804 check_curr_ui_sync_execution_done (void)
3806 struct ui
*ui
= current_ui
;
3808 if (ui
->prompt_state
== PROMPT_NEEDED
3810 && !gdb_in_secondary_prompt_p (ui
))
3812 target_terminal::ours ();
3813 gdb::observers::sync_execution_done
.notify ();
3814 ui_register_input_event_handler (ui
);
3821 all_uis_check_sync_execution_done (void)
3823 SWITCH_THRU_ALL_UIS ()
3825 check_curr_ui_sync_execution_done ();
3832 all_uis_on_sync_execution_starting (void)
3834 SWITCH_THRU_ALL_UIS ()
3836 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3837 async_disable_stdin ();
3841 /* Asynchronous version of wait_for_inferior. It is called by the
3842 event loop whenever a change of state is detected on the file
3843 descriptor corresponding to the target. It can be called more than
3844 once to complete a single execution command. In such cases we need
3845 to keep the state in a global variable ECSS. If it is the last time
3846 that this function is called for a single execution command, then
3847 report to the user that the inferior has stopped, and do the
3848 necessary cleanups. */
3851 fetch_inferior_event ()
3853 struct execution_control_state ecss
;
3854 struct execution_control_state
*ecs
= &ecss
;
3857 memset (ecs
, 0, sizeof (*ecs
));
3859 /* Events are always processed with the main UI as current UI. This
3860 way, warnings, debug output, etc. are always consistently sent to
3861 the main console. */
3862 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3864 /* End up with readline processing input, if necessary. */
3866 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3868 /* We're handling a live event, so make sure we're doing live
3869 debugging. If we're looking at traceframes while the target is
3870 running, we're going to need to get back to that mode after
3871 handling the event. */
3872 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3875 maybe_restore_traceframe
.emplace ();
3876 set_current_traceframe (-1);
3879 /* The user/frontend should not notice a thread switch due to
3880 internal events. Make sure we revert to the user selected
3881 thread and frame after handling the event and running any
3882 breakpoint commands. */
3883 scoped_restore_current_thread restore_thread
;
3885 overlay_cache_invalid
= 1;
3886 /* Flush target cache before starting to handle each event. Target
3887 was running and cache could be stale. This is just a heuristic.
3888 Running threads may modify target memory, but we don't get any
3890 target_dcache_invalidate ();
3892 scoped_restore save_exec_dir
3893 = make_scoped_restore (&execution_direction
,
3894 target_execution_direction ());
3896 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3899 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3901 /* Switch to the target that generated the event, so we can do
3902 target calls. Any inferior bound to the target will do, so we
3903 just switch to the first we find. */
3904 for (inferior
*inf
: all_inferiors (ecs
->target
))
3906 switch_to_inferior_no_thread (inf
);
3911 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3913 /* If an error happens while handling the event, propagate GDB's
3914 knowledge of the executing state to the frontend/user running
3916 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3917 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3919 /* Get executed before scoped_restore_current_thread above to apply
3920 still for the thread which has thrown the exception. */
3921 auto defer_bpstat_clear
3922 = make_scope_exit (bpstat_clear_actions
);
3923 auto defer_delete_threads
3924 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3926 /* Now figure out what to do with the result of the result. */
3927 handle_inferior_event (ecs
);
3929 if (!ecs
->wait_some_more
)
3931 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3932 int should_stop
= 1;
3933 struct thread_info
*thr
= ecs
->event_thread
;
3935 delete_just_stopped_threads_infrun_breakpoints ();
3939 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3941 if (thread_fsm
!= NULL
)
3942 should_stop
= thread_fsm
->should_stop (thr
);
3951 bool should_notify_stop
= true;
3954 clean_up_just_stopped_threads_fsms (ecs
);
3956 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3957 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3959 if (should_notify_stop
)
3961 /* We may not find an inferior if this was a process exit. */
3962 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3963 proceeded
= normal_stop ();
3968 inferior_event_handler (INF_EXEC_COMPLETE
);
3972 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3973 previously selected thread is gone. We have two
3974 choices - switch to no thread selected, or restore the
3975 previously selected thread (now exited). We chose the
3976 later, just because that's what GDB used to do. After
3977 this, "info threads" says "The current thread <Thread
3978 ID 2> has terminated." instead of "No thread
3982 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3983 restore_thread
.dont_restore ();
3987 defer_delete_threads
.release ();
3988 defer_bpstat_clear
.release ();
3990 /* No error, don't finish the thread states yet. */
3991 finish_state
.release ();
3993 /* This scope is used to ensure that readline callbacks are
3994 reinstalled here. */
3997 /* If a UI was in sync execution mode, and now isn't, restore its
3998 prompt (a synchronous execution command has finished, and we're
3999 ready for input). */
4000 all_uis_check_sync_execution_done ();
4003 && exec_done_display_p
4004 && (inferior_ptid
== null_ptid
4005 || inferior_thread ()->state
!= THREAD_RUNNING
))
4006 printf_unfiltered (_("completed.\n"));
4012 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4013 struct symtab_and_line sal
)
4015 /* This can be removed once this function no longer implicitly relies on the
4016 inferior_ptid value. */
4017 gdb_assert (inferior_ptid
== tp
->ptid
);
4019 tp
->control
.step_frame_id
= get_frame_id (frame
);
4020 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4022 tp
->current_symtab
= sal
.symtab
;
4023 tp
->current_line
= sal
.line
;
4026 /* Clear context switchable stepping state. */
4029 init_thread_stepping_state (struct thread_info
*tss
)
4031 tss
->stepped_breakpoint
= 0;
4032 tss
->stepping_over_breakpoint
= 0;
4033 tss
->stepping_over_watchpoint
= 0;
4034 tss
->step_after_step_resume_breakpoint
= 0;
4040 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4041 target_waitstatus status
)
4043 target_last_proc_target
= target
;
4044 target_last_wait_ptid
= ptid
;
4045 target_last_waitstatus
= status
;
4051 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4052 target_waitstatus
*status
)
4054 if (target
!= nullptr)
4055 *target
= target_last_proc_target
;
4056 if (ptid
!= nullptr)
4057 *ptid
= target_last_wait_ptid
;
4058 if (status
!= nullptr)
4059 *status
= target_last_waitstatus
;
4065 nullify_last_target_wait_ptid (void)
4067 target_last_proc_target
= nullptr;
4068 target_last_wait_ptid
= minus_one_ptid
;
4069 target_last_waitstatus
= {};
4072 /* Switch thread contexts. */
4075 context_switch (execution_control_state
*ecs
)
4077 if (ecs
->ptid
!= inferior_ptid
4078 && (inferior_ptid
== null_ptid
4079 || ecs
->event_thread
!= inferior_thread ()))
4081 infrun_log_debug ("Switching context from %s to %s",
4082 target_pid_to_str (inferior_ptid
).c_str (),
4083 target_pid_to_str (ecs
->ptid
).c_str ());
4086 switch_to_thread (ecs
->event_thread
);
4089 /* If the target can't tell whether we've hit breakpoints
4090 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4091 check whether that could have been caused by a breakpoint. If so,
4092 adjust the PC, per gdbarch_decr_pc_after_break. */
4095 adjust_pc_after_break (struct thread_info
*thread
,
4096 struct target_waitstatus
*ws
)
4098 struct regcache
*regcache
;
4099 struct gdbarch
*gdbarch
;
4100 CORE_ADDR breakpoint_pc
, decr_pc
;
4102 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4103 we aren't, just return.
4105 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4106 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4107 implemented by software breakpoints should be handled through the normal
4110 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4111 different signals (SIGILL or SIGEMT for instance), but it is less
4112 clear where the PC is pointing afterwards. It may not match
4113 gdbarch_decr_pc_after_break. I don't know any specific target that
4114 generates these signals at breakpoints (the code has been in GDB since at
4115 least 1992) so I can not guess how to handle them here.
4117 In earlier versions of GDB, a target with
4118 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4119 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4120 target with both of these set in GDB history, and it seems unlikely to be
4121 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4123 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4126 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4129 /* In reverse execution, when a breakpoint is hit, the instruction
4130 under it has already been de-executed. The reported PC always
4131 points at the breakpoint address, so adjusting it further would
4132 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4135 B1 0x08000000 : INSN1
4136 B2 0x08000001 : INSN2
4138 PC -> 0x08000003 : INSN4
4140 Say you're stopped at 0x08000003 as above. Reverse continuing
4141 from that point should hit B2 as below. Reading the PC when the
4142 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4143 been de-executed already.
4145 B1 0x08000000 : INSN1
4146 B2 PC -> 0x08000001 : INSN2
4150 We can't apply the same logic as for forward execution, because
4151 we would wrongly adjust the PC to 0x08000000, since there's a
4152 breakpoint at PC - 1. We'd then report a hit on B1, although
4153 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4155 if (execution_direction
== EXEC_REVERSE
)
4158 /* If the target can tell whether the thread hit a SW breakpoint,
4159 trust it. Targets that can tell also adjust the PC
4161 if (target_supports_stopped_by_sw_breakpoint ())
4164 /* Note that relying on whether a breakpoint is planted in memory to
4165 determine this can fail. E.g,. the breakpoint could have been
4166 removed since. Or the thread could have been told to step an
4167 instruction the size of a breakpoint instruction, and only
4168 _after_ was a breakpoint inserted at its address. */
4170 /* If this target does not decrement the PC after breakpoints, then
4171 we have nothing to do. */
4172 regcache
= get_thread_regcache (thread
);
4173 gdbarch
= regcache
->arch ();
4175 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4179 const address_space
*aspace
= regcache
->aspace ();
4181 /* Find the location where (if we've hit a breakpoint) the
4182 breakpoint would be. */
4183 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4185 /* If the target can't tell whether a software breakpoint triggered,
4186 fallback to figuring it out based on breakpoints we think were
4187 inserted in the target, and on whether the thread was stepped or
4190 /* Check whether there actually is a software breakpoint inserted at
4193 If in non-stop mode, a race condition is possible where we've
4194 removed a breakpoint, but stop events for that breakpoint were
4195 already queued and arrive later. To suppress those spurious
4196 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4197 and retire them after a number of stop events are reported. Note
4198 this is an heuristic and can thus get confused. The real fix is
4199 to get the "stopped by SW BP and needs adjustment" info out of
4200 the target/kernel (and thus never reach here; see above). */
4201 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4202 || (target_is_non_stop_p ()
4203 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4205 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4207 if (record_full_is_used ())
4208 restore_operation_disable
.emplace
4209 (record_full_gdb_operation_disable_set ());
4211 /* When using hardware single-step, a SIGTRAP is reported for both
4212 a completed single-step and a software breakpoint. Need to
4213 differentiate between the two, as the latter needs adjusting
4214 but the former does not.
4216 The SIGTRAP can be due to a completed hardware single-step only if
4217 - we didn't insert software single-step breakpoints
4218 - this thread is currently being stepped
4220 If any of these events did not occur, we must have stopped due
4221 to hitting a software breakpoint, and have to back up to the
4224 As a special case, we could have hardware single-stepped a
4225 software breakpoint. In this case (prev_pc == breakpoint_pc),
4226 we also need to back up to the breakpoint address. */
4228 if (thread_has_single_step_breakpoints_set (thread
)
4229 || !currently_stepping (thread
)
4230 || (thread
->stepped_breakpoint
4231 && thread
->prev_pc
== breakpoint_pc
))
4232 regcache_write_pc (regcache
, breakpoint_pc
);
4237 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4239 for (frame
= get_prev_frame (frame
);
4241 frame
= get_prev_frame (frame
))
4243 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4245 if (get_frame_type (frame
) != INLINE_FRAME
)
4252 /* Look for an inline frame that is marked for skip.
4253 If PREV_FRAME is TRUE start at the previous frame,
4254 otherwise start at the current frame. Stop at the
4255 first non-inline frame, or at the frame where the
4259 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4261 struct frame_info
*frame
= get_current_frame ();
4264 frame
= get_prev_frame (frame
);
4266 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4268 const char *fn
= NULL
;
4269 symtab_and_line sal
;
4272 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4274 if (get_frame_type (frame
) != INLINE_FRAME
)
4277 sal
= find_frame_sal (frame
);
4278 sym
= get_frame_function (frame
);
4281 fn
= sym
->print_name ();
4284 && function_name_is_marked_for_skip (fn
, sal
))
4291 /* If the event thread has the stop requested flag set, pretend it
4292 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4296 handle_stop_requested (struct execution_control_state
*ecs
)
4298 if (ecs
->event_thread
->stop_requested
)
4300 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4301 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4302 handle_signal_stop (ecs
);
4308 /* Auxiliary function that handles syscall entry/return events.
4309 It returns 1 if the inferior should keep going (and GDB
4310 should ignore the event), or 0 if the event deserves to be
4314 handle_syscall_event (struct execution_control_state
*ecs
)
4316 struct regcache
*regcache
;
4319 context_switch (ecs
);
4321 regcache
= get_thread_regcache (ecs
->event_thread
);
4322 syscall_number
= ecs
->ws
.value
.syscall_number
;
4323 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4325 if (catch_syscall_enabled () > 0
4326 && catching_syscall_number (syscall_number
) > 0)
4328 infrun_log_debug ("syscall number=%d", syscall_number
);
4330 ecs
->event_thread
->control
.stop_bpstat
4331 = bpstat_stop_status (regcache
->aspace (),
4332 ecs
->event_thread
->suspend
.stop_pc
,
4333 ecs
->event_thread
, &ecs
->ws
);
4335 if (handle_stop_requested (ecs
))
4338 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4340 /* Catchpoint hit. */
4345 if (handle_stop_requested (ecs
))
4348 /* If no catchpoint triggered for this, then keep going. */
4353 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4356 fill_in_stop_func (struct gdbarch
*gdbarch
,
4357 struct execution_control_state
*ecs
)
4359 if (!ecs
->stop_func_filled_in
)
4363 /* Don't care about return value; stop_func_start and stop_func_name
4364 will both be 0 if it doesn't work. */
4365 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4366 &ecs
->stop_func_name
,
4367 &ecs
->stop_func_start
,
4368 &ecs
->stop_func_end
,
4371 /* The call to find_pc_partial_function, above, will set
4372 stop_func_start and stop_func_end to the start and end
4373 of the range containing the stop pc. If this range
4374 contains the entry pc for the block (which is always the
4375 case for contiguous blocks), advance stop_func_start past
4376 the function's start offset and entrypoint. Note that
4377 stop_func_start is NOT advanced when in a range of a
4378 non-contiguous block that does not contain the entry pc. */
4379 if (block
!= nullptr
4380 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4381 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4383 ecs
->stop_func_start
4384 += gdbarch_deprecated_function_start_offset (gdbarch
);
4386 if (gdbarch_skip_entrypoint_p (gdbarch
))
4387 ecs
->stop_func_start
4388 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4391 ecs
->stop_func_filled_in
= 1;
4396 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4398 static enum stop_kind
4399 get_inferior_stop_soon (execution_control_state
*ecs
)
4401 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4403 gdb_assert (inf
!= NULL
);
4404 return inf
->control
.stop_soon
;
4407 /* Poll for one event out of the current target. Store the resulting
4408 waitstatus in WS, and return the event ptid. Does not block. */
4411 poll_one_curr_target (struct target_waitstatus
*ws
)
4415 overlay_cache_invalid
= 1;
4417 /* Flush target cache before starting to handle each event.
4418 Target was running and cache could be stale. This is just a
4419 heuristic. Running threads may modify target memory, but we
4420 don't get any event. */
4421 target_dcache_invalidate ();
4423 if (deprecated_target_wait_hook
)
4424 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4426 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4429 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4434 /* An event reported by wait_one. */
4436 struct wait_one_event
4438 /* The target the event came out of. */
4439 process_stratum_target
*target
;
4441 /* The PTID the event was for. */
4444 /* The waitstatus. */
4445 target_waitstatus ws
;
4448 /* Wait for one event out of any target. */
4450 static wait_one_event
4455 for (inferior
*inf
: all_inferiors ())
4457 process_stratum_target
*target
= inf
->process_target ();
4459 || !target
->is_async_p ()
4460 || !target
->threads_executing
)
4463 switch_to_inferior_no_thread (inf
);
4465 wait_one_event event
;
4466 event
.target
= target
;
4467 event
.ptid
= poll_one_curr_target (&event
.ws
);
4469 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4471 /* If nothing is resumed, remove the target from the
4475 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4479 /* Block waiting for some event. */
4486 for (inferior
*inf
: all_inferiors ())
4488 process_stratum_target
*target
= inf
->process_target ();
4490 || !target
->is_async_p ()
4491 || !target
->threads_executing
)
4494 int fd
= target
->async_wait_fd ();
4495 FD_SET (fd
, &readfds
);
4502 /* No waitable targets left. All must be stopped. */
4503 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4508 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4514 perror_with_name ("interruptible_select");
4519 /* Save the thread's event and stop reason to process it later. */
4522 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4524 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4525 target_waitstatus_to_string (ws
).c_str (),
4530 /* Record for later. */
4531 tp
->suspend
.waitstatus
= *ws
;
4532 tp
->suspend
.waitstatus_pending_p
= 1;
4534 struct regcache
*regcache
= get_thread_regcache (tp
);
4535 const address_space
*aspace
= regcache
->aspace ();
4537 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4538 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4540 CORE_ADDR pc
= regcache_read_pc (regcache
);
4542 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4544 scoped_restore_current_thread restore_thread
;
4545 switch_to_thread (tp
);
4547 if (target_stopped_by_watchpoint ())
4549 tp
->suspend
.stop_reason
4550 = TARGET_STOPPED_BY_WATCHPOINT
;
4552 else if (target_supports_stopped_by_sw_breakpoint ()
4553 && target_stopped_by_sw_breakpoint ())
4555 tp
->suspend
.stop_reason
4556 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4558 else if (target_supports_stopped_by_hw_breakpoint ()
4559 && target_stopped_by_hw_breakpoint ())
4561 tp
->suspend
.stop_reason
4562 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4564 else if (!target_supports_stopped_by_hw_breakpoint ()
4565 && hardware_breakpoint_inserted_here_p (aspace
,
4568 tp
->suspend
.stop_reason
4569 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4571 else if (!target_supports_stopped_by_sw_breakpoint ()
4572 && software_breakpoint_inserted_here_p (aspace
,
4575 tp
->suspend
.stop_reason
4576 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4578 else if (!thread_has_single_step_breakpoints_set (tp
)
4579 && currently_stepping (tp
))
4581 tp
->suspend
.stop_reason
4582 = TARGET_STOPPED_BY_SINGLE_STEP
;
4587 /* Mark the non-executing threads accordingly. In all-stop, all
4588 threads of all processes are stopped when we get any event
4589 reported. In non-stop mode, only the event thread stops. */
4592 mark_non_executing_threads (process_stratum_target
*target
,
4594 struct target_waitstatus ws
)
4598 if (!target_is_non_stop_p ())
4599 mark_ptid
= minus_one_ptid
;
4600 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4601 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4603 /* If we're handling a process exit in non-stop mode, even
4604 though threads haven't been deleted yet, one would think
4605 that there is nothing to do, as threads of the dead process
4606 will be soon deleted, and threads of any other process were
4607 left running. However, on some targets, threads survive a
4608 process exit event. E.g., for the "checkpoint" command,
4609 when the current checkpoint/fork exits, linux-fork.c
4610 automatically switches to another fork from within
4611 target_mourn_inferior, by associating the same
4612 inferior/thread to another fork. We haven't mourned yet at
4613 this point, but we must mark any threads left in the
4614 process as not-executing so that finish_thread_state marks
4615 them stopped (in the user's perspective) if/when we present
4616 the stop to the user. */
4617 mark_ptid
= ptid_t (event_ptid
.pid ());
4620 mark_ptid
= event_ptid
;
4622 set_executing (target
, mark_ptid
, false);
4624 /* Likewise the resumed flag. */
4625 set_resumed (target
, mark_ptid
, false);
4631 stop_all_threads (void)
4633 /* We may need multiple passes to discover all threads. */
4637 gdb_assert (exists_non_stop_target ());
4639 infrun_log_debug ("stop_all_threads");
4641 scoped_restore_current_thread restore_thread
;
4643 /* Enable thread events of all targets. */
4644 for (auto *target
: all_non_exited_process_targets ())
4646 switch_to_target_no_thread (target
);
4647 target_thread_events (true);
4652 /* Disable thread events of all targets. */
4653 for (auto *target
: all_non_exited_process_targets ())
4655 switch_to_target_no_thread (target
);
4656 target_thread_events (false);
4660 infrun_log_debug ("stop_all_threads done");
4663 /* Request threads to stop, and then wait for the stops. Because
4664 threads we already know about can spawn more threads while we're
4665 trying to stop them, and we only learn about new threads when we
4666 update the thread list, do this in a loop, and keep iterating
4667 until two passes find no threads that need to be stopped. */
4668 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4670 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4674 int waits_needed
= 0;
4676 for (auto *target
: all_non_exited_process_targets ())
4678 switch_to_target_no_thread (target
);
4679 update_thread_list ();
4682 /* Go through all threads looking for threads that we need
4683 to tell the target to stop. */
4684 for (thread_info
*t
: all_non_exited_threads ())
4686 /* For a single-target setting with an all-stop target,
4687 we would not even arrive here. For a multi-target
4688 setting, until GDB is able to handle a mixture of
4689 all-stop and non-stop targets, simply skip all-stop
4690 targets' threads. This should be fine due to the
4691 protection of 'check_multi_target_resumption'. */
4693 switch_to_thread_no_regs (t
);
4694 if (!target_is_non_stop_p ())
4699 /* If already stopping, don't request a stop again.
4700 We just haven't seen the notification yet. */
4701 if (!t
->stop_requested
)
4703 infrun_log_debug (" %s executing, need stop",
4704 target_pid_to_str (t
->ptid
).c_str ());
4705 target_stop (t
->ptid
);
4706 t
->stop_requested
= 1;
4710 infrun_log_debug (" %s executing, already stopping",
4711 target_pid_to_str (t
->ptid
).c_str ());
4714 if (t
->stop_requested
)
4719 infrun_log_debug (" %s not executing",
4720 target_pid_to_str (t
->ptid
).c_str ());
4722 /* The thread may be not executing, but still be
4723 resumed with a pending status to process. */
4728 if (waits_needed
== 0)
4731 /* If we find new threads on the second iteration, restart
4732 over. We want to see two iterations in a row with all
4737 for (int i
= 0; i
< waits_needed
; i
++)
4739 wait_one_event event
= wait_one ();
4741 infrun_log_debug ("%s %s\n",
4742 target_waitstatus_to_string (&event
.ws
).c_str (),
4743 target_pid_to_str (event
.ptid
).c_str ());
4745 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4747 /* All resumed threads exited. */
4750 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4751 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4752 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4754 /* One thread/process exited/signalled. */
4756 thread_info
*t
= nullptr;
4758 /* The target may have reported just a pid. If so, try
4759 the first non-exited thread. */
4760 if (event
.ptid
.is_pid ())
4762 int pid
= event
.ptid
.pid ();
4763 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4764 for (thread_info
*tp
: inf
->non_exited_threads ())
4770 /* If there is no available thread, the event would
4771 have to be appended to a per-inferior event list,
4772 which does not exist (and if it did, we'd have
4773 to adjust run control command to be able to
4774 resume such an inferior). We assert here instead
4775 of going into an infinite loop. */
4776 gdb_assert (t
!= nullptr);
4778 infrun_log_debug ("using %s\n",
4779 target_pid_to_str (t
->ptid
).c_str ());
4783 t
= find_thread_ptid (event
.target
, event
.ptid
);
4784 /* Check if this is the first time we see this thread.
4785 Don't bother adding if it individually exited. */
4787 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4788 t
= add_thread (event
.target
, event
.ptid
);
4793 /* Set the threads as non-executing to avoid
4794 another stop attempt on them. */
4795 switch_to_thread_no_regs (t
);
4796 mark_non_executing_threads (event
.target
, event
.ptid
,
4798 save_waitstatus (t
, &event
.ws
);
4799 t
->stop_requested
= false;
4804 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4806 t
= add_thread (event
.target
, event
.ptid
);
4808 t
->stop_requested
= 0;
4811 t
->control
.may_range_step
= 0;
4813 /* This may be the first time we see the inferior report
4815 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4816 if (inf
->needs_setup
)
4818 switch_to_thread_no_regs (t
);
4822 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4823 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4825 /* We caught the event that we intended to catch, so
4826 there's no event pending. */
4827 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4828 t
->suspend
.waitstatus_pending_p
= 0;
4830 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4832 /* Add it back to the step-over queue. */
4833 infrun_log_debug ("displaced-step of %s "
4834 "canceled: adding back to the "
4835 "step-over queue\n",
4836 target_pid_to_str (t
->ptid
).c_str ());
4838 t
->control
.trap_expected
= 0;
4839 global_thread_step_over_chain_enqueue (t
);
4844 enum gdb_signal sig
;
4845 struct regcache
*regcache
;
4849 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4851 infrun_log_debug ("target_wait %s, saving "
4852 "status for %d.%ld.%ld\n",
4859 /* Record for later. */
4860 save_waitstatus (t
, &event
.ws
);
4862 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4863 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4865 if (displaced_step_finish (t
, sig
) < 0)
4867 /* Add it back to the step-over queue. */
4868 t
->control
.trap_expected
= 0;
4869 global_thread_step_over_chain_enqueue (t
);
4872 regcache
= get_thread_regcache (t
);
4873 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4875 infrun_log_debug ("saved stop_pc=%s for %s "
4876 "(currently_stepping=%d)\n",
4877 paddress (target_gdbarch (),
4878 t
->suspend
.stop_pc
),
4879 target_pid_to_str (t
->ptid
).c_str (),
4880 currently_stepping (t
));
4888 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4891 handle_no_resumed (struct execution_control_state
*ecs
)
4893 if (target_can_async_p ())
4897 for (ui
*ui
: all_uis ())
4899 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4907 /* There were no unwaited-for children left in the target, but,
4908 we're not synchronously waiting for events either. Just
4911 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4912 prepare_to_wait (ecs
);
4917 /* Otherwise, if we were running a synchronous execution command, we
4918 may need to cancel it and give the user back the terminal.
4920 In non-stop mode, the target can't tell whether we've already
4921 consumed previous stop events, so it can end up sending us a
4922 no-resumed event like so:
4924 #0 - thread 1 is left stopped
4926 #1 - thread 2 is resumed and hits breakpoint
4927 -> TARGET_WAITKIND_STOPPED
4929 #2 - thread 3 is resumed and exits
4930 this is the last resumed thread, so
4931 -> TARGET_WAITKIND_NO_RESUMED
4933 #3 - gdb processes stop for thread 2 and decides to re-resume
4936 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4937 thread 2 is now resumed, so the event should be ignored.
4939 IOW, if the stop for thread 2 doesn't end a foreground command,
4940 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4941 event. But it could be that the event meant that thread 2 itself
4942 (or whatever other thread was the last resumed thread) exited.
4944 To address this we refresh the thread list and check whether we
4945 have resumed threads _now_. In the example above, this removes
4946 thread 3 from the thread list. If thread 2 was re-resumed, we
4947 ignore this event. If we find no thread resumed, then we cancel
4948 the synchronous command and show "no unwaited-for " to the
4951 inferior
*curr_inf
= current_inferior ();
4953 scoped_restore_current_thread restore_thread
;
4955 for (auto *target
: all_non_exited_process_targets ())
4957 switch_to_target_no_thread (target
);
4958 update_thread_list ();
4963 - the current target has no thread executing, and
4964 - the current inferior is native, and
4965 - the current inferior is the one which has the terminal, and
4968 then a Ctrl-C from this point on would remain stuck in the
4969 kernel, until a thread resumes and dequeues it. That would
4970 result in the GDB CLI not reacting to Ctrl-C, not able to
4971 interrupt the program. To address this, if the current inferior
4972 no longer has any thread executing, we give the terminal to some
4973 other inferior that has at least one thread executing. */
4974 bool swap_terminal
= true;
4976 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4977 whether to report it to the user. */
4978 bool ignore_event
= false;
4980 for (thread_info
*thread
: all_non_exited_threads ())
4982 if (swap_terminal
&& thread
->executing
)
4984 if (thread
->inf
!= curr_inf
)
4986 target_terminal::ours ();
4988 switch_to_thread (thread
);
4989 target_terminal::inferior ();
4991 swap_terminal
= false;
4995 && (thread
->executing
4996 || thread
->suspend
.waitstatus_pending_p
))
4998 /* Either there were no unwaited-for children left in the
4999 target at some point, but there are now, or some target
5000 other than the eventing one has unwaited-for children
5001 left. Just ignore. */
5002 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
5003 "(ignoring: found resumed)\n");
5005 ignore_event
= true;
5008 if (ignore_event
&& !swap_terminal
)
5014 switch_to_inferior_no_thread (curr_inf
);
5015 prepare_to_wait (ecs
);
5019 /* Go ahead and report the event. */
5023 /* Given an execution control state that has been freshly filled in by
5024 an event from the inferior, figure out what it means and take
5027 The alternatives are:
5029 1) stop_waiting and return; to really stop and return to the
5032 2) keep_going and return; to wait for the next event (set
5033 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5037 handle_inferior_event (struct execution_control_state
*ecs
)
5039 /* Make sure that all temporary struct value objects that were
5040 created during the handling of the event get deleted at the
5042 scoped_value_mark free_values
;
5044 enum stop_kind stop_soon
;
5046 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5048 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5050 /* We had an event in the inferior, but we are not interested in
5051 handling it at this level. The lower layers have already
5052 done what needs to be done, if anything.
5054 One of the possible circumstances for this is when the
5055 inferior produces output for the console. The inferior has
5056 not stopped, and we are ignoring the event. Another possible
5057 circumstance is any event which the lower level knows will be
5058 reported multiple times without an intervening resume. */
5059 prepare_to_wait (ecs
);
5063 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5065 prepare_to_wait (ecs
);
5069 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5070 && handle_no_resumed (ecs
))
5073 /* Cache the last target/ptid/waitstatus. */
5074 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5076 /* Always clear state belonging to the previous time we stopped. */
5077 stop_stack_dummy
= STOP_NONE
;
5079 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5081 /* No unwaited-for children left. IOW, all resumed children
5083 stop_print_frame
= 0;
5088 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5089 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5091 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5092 /* If it's a new thread, add it to the thread database. */
5093 if (ecs
->event_thread
== NULL
)
5094 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5096 /* Disable range stepping. If the next step request could use a
5097 range, this will be end up re-enabled then. */
5098 ecs
->event_thread
->control
.may_range_step
= 0;
5101 /* Dependent on valid ECS->EVENT_THREAD. */
5102 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5104 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5105 reinit_frame_cache ();
5107 breakpoint_retire_moribund ();
5109 /* First, distinguish signals caused by the debugger from signals
5110 that have to do with the program's own actions. Note that
5111 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5112 on the operating system version. Here we detect when a SIGILL or
5113 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5114 something similar for SIGSEGV, since a SIGSEGV will be generated
5115 when we're trying to execute a breakpoint instruction on a
5116 non-executable stack. This happens for call dummy breakpoints
5117 for architectures like SPARC that place call dummies on the
5119 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5120 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5121 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5122 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5124 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5126 if (breakpoint_inserted_here_p (regcache
->aspace (),
5127 regcache_read_pc (regcache
)))
5129 infrun_log_debug ("Treating signal as SIGTRAP");
5130 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5134 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5136 switch (ecs
->ws
.kind
)
5138 case TARGET_WAITKIND_LOADED
:
5139 context_switch (ecs
);
5140 /* Ignore gracefully during startup of the inferior, as it might
5141 be the shell which has just loaded some objects, otherwise
5142 add the symbols for the newly loaded objects. Also ignore at
5143 the beginning of an attach or remote session; we will query
5144 the full list of libraries once the connection is
5147 stop_soon
= get_inferior_stop_soon (ecs
);
5148 if (stop_soon
== NO_STOP_QUIETLY
)
5150 struct regcache
*regcache
;
5152 regcache
= get_thread_regcache (ecs
->event_thread
);
5154 handle_solib_event ();
5156 ecs
->event_thread
->control
.stop_bpstat
5157 = bpstat_stop_status (regcache
->aspace (),
5158 ecs
->event_thread
->suspend
.stop_pc
,
5159 ecs
->event_thread
, &ecs
->ws
);
5161 if (handle_stop_requested (ecs
))
5164 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5166 /* A catchpoint triggered. */
5167 process_event_stop_test (ecs
);
5171 /* If requested, stop when the dynamic linker notifies
5172 gdb of events. This allows the user to get control
5173 and place breakpoints in initializer routines for
5174 dynamically loaded objects (among other things). */
5175 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5176 if (stop_on_solib_events
)
5178 /* Make sure we print "Stopped due to solib-event" in
5180 stop_print_frame
= 1;
5187 /* If we are skipping through a shell, or through shared library
5188 loading that we aren't interested in, resume the program. If
5189 we're running the program normally, also resume. */
5190 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5192 /* Loading of shared libraries might have changed breakpoint
5193 addresses. Make sure new breakpoints are inserted. */
5194 if (stop_soon
== NO_STOP_QUIETLY
)
5195 insert_breakpoints ();
5196 resume (GDB_SIGNAL_0
);
5197 prepare_to_wait (ecs
);
5201 /* But stop if we're attaching or setting up a remote
5203 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5204 || stop_soon
== STOP_QUIETLY_REMOTE
)
5206 infrun_log_debug ("quietly stopped");
5211 internal_error (__FILE__
, __LINE__
,
5212 _("unhandled stop_soon: %d"), (int) stop_soon
);
5214 case TARGET_WAITKIND_SPURIOUS
:
5215 if (handle_stop_requested (ecs
))
5217 context_switch (ecs
);
5218 resume (GDB_SIGNAL_0
);
5219 prepare_to_wait (ecs
);
5222 case TARGET_WAITKIND_THREAD_CREATED
:
5223 if (handle_stop_requested (ecs
))
5225 context_switch (ecs
);
5226 if (!switch_back_to_stepped_thread (ecs
))
5230 case TARGET_WAITKIND_EXITED
:
5231 case TARGET_WAITKIND_SIGNALLED
:
5233 /* Depending on the system, ecs->ptid may point to a thread or
5234 to a process. On some targets, target_mourn_inferior may
5235 need to have access to the just-exited thread. That is the
5236 case of GNU/Linux's "checkpoint" support, for example.
5237 Call the switch_to_xxx routine as appropriate. */
5238 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5240 switch_to_thread (thr
);
5243 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5244 switch_to_inferior_no_thread (inf
);
5247 handle_vfork_child_exec_or_exit (0);
5248 target_terminal::ours (); /* Must do this before mourn anyway. */
5250 /* Clearing any previous state of convenience variables. */
5251 clear_exit_convenience_vars ();
5253 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5255 /* Record the exit code in the convenience variable $_exitcode, so
5256 that the user can inspect this again later. */
5257 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5258 (LONGEST
) ecs
->ws
.value
.integer
);
5260 /* Also record this in the inferior itself. */
5261 current_inferior ()->has_exit_code
= 1;
5262 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5264 /* Support the --return-child-result option. */
5265 return_child_result_value
= ecs
->ws
.value
.integer
;
5267 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5271 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5273 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5275 /* Set the value of the internal variable $_exitsignal,
5276 which holds the signal uncaught by the inferior. */
5277 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5278 gdbarch_gdb_signal_to_target (gdbarch
,
5279 ecs
->ws
.value
.sig
));
5283 /* We don't have access to the target's method used for
5284 converting between signal numbers (GDB's internal
5285 representation <-> target's representation).
5286 Therefore, we cannot do a good job at displaying this
5287 information to the user. It's better to just warn
5288 her about it (if infrun debugging is enabled), and
5290 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5294 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5297 gdb_flush (gdb_stdout
);
5298 target_mourn_inferior (inferior_ptid
);
5299 stop_print_frame
= 0;
5303 case TARGET_WAITKIND_FORKED
:
5304 case TARGET_WAITKIND_VFORKED
:
5305 /* Check whether the inferior is displaced stepping. */
5307 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5308 struct gdbarch
*gdbarch
= regcache
->arch ();
5310 /* If checking displaced stepping is supported, and thread
5311 ecs->ptid is displaced stepping. */
5312 if (displaced_step_in_progress (ecs
->event_thread
))
5314 struct inferior
*parent_inf
5315 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5316 struct regcache
*child_regcache
;
5317 CORE_ADDR parent_pc
;
5319 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5321 // struct displaced_step_inferior_state *displaced
5322 // = get_displaced_stepping_state (parent_inf);
5324 /* Restore scratch pad for child process. */
5325 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5326 // FIXME: we should restore all the buffers that were currently in use
5329 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5330 indicating that the displaced stepping of syscall instruction
5331 has been done. Perform cleanup for parent process here. Note
5332 that this operation also cleans up the child process for vfork,
5333 because their pages are shared. */
5334 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5335 /* Start a new step-over in another thread if there's one
5339 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5340 the child's PC is also within the scratchpad. Set the child's PC
5341 to the parent's PC value, which has already been fixed up.
5342 FIXME: we use the parent's aspace here, although we're touching
5343 the child, because the child hasn't been added to the inferior
5344 list yet at this point. */
5347 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5348 ecs
->ws
.value
.related_pid
,
5350 parent_inf
->aspace
);
5351 /* Read PC value of parent process. */
5352 parent_pc
= regcache_read_pc (regcache
);
5354 if (debug_displaced
)
5355 fprintf_unfiltered (gdb_stdlog
,
5356 "displaced: write child pc from %s to %s\n",
5358 regcache_read_pc (child_regcache
)),
5359 paddress (gdbarch
, parent_pc
));
5361 regcache_write_pc (child_regcache
, parent_pc
);
5365 context_switch (ecs
);
5367 /* Immediately detach breakpoints from the child before there's
5368 any chance of letting the user delete breakpoints from the
5369 breakpoint lists. If we don't do this early, it's easy to
5370 leave left over traps in the child, vis: "break foo; catch
5371 fork; c; <fork>; del; c; <child calls foo>". We only follow
5372 the fork on the last `continue', and by that time the
5373 breakpoint at "foo" is long gone from the breakpoint table.
5374 If we vforked, then we don't need to unpatch here, since both
5375 parent and child are sharing the same memory pages; we'll
5376 need to unpatch at follow/detach time instead to be certain
5377 that new breakpoints added between catchpoint hit time and
5378 vfork follow are detached. */
5379 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5381 /* This won't actually modify the breakpoint list, but will
5382 physically remove the breakpoints from the child. */
5383 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5386 delete_just_stopped_threads_single_step_breakpoints ();
5388 /* In case the event is caught by a catchpoint, remember that
5389 the event is to be followed at the next resume of the thread,
5390 and not immediately. */
5391 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5393 ecs
->event_thread
->suspend
.stop_pc
5394 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5396 ecs
->event_thread
->control
.stop_bpstat
5397 = bpstat_stop_status (get_current_regcache ()->aspace (),
5398 ecs
->event_thread
->suspend
.stop_pc
,
5399 ecs
->event_thread
, &ecs
->ws
);
5401 if (handle_stop_requested (ecs
))
5404 /* If no catchpoint triggered for this, then keep going. Note
5405 that we're interested in knowing the bpstat actually causes a
5406 stop, not just if it may explain the signal. Software
5407 watchpoints, for example, always appear in the bpstat. */
5408 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5411 = (follow_fork_mode_string
== follow_fork_mode_child
);
5413 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5415 process_stratum_target
*targ
5416 = ecs
->event_thread
->inf
->process_target ();
5418 bool should_resume
= follow_fork ();
5420 /* Note that one of these may be an invalid pointer,
5421 depending on detach_fork. */
5422 thread_info
*parent
= ecs
->event_thread
;
5424 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5426 /* At this point, the parent is marked running, and the
5427 child is marked stopped. */
5429 /* If not resuming the parent, mark it stopped. */
5430 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5431 parent
->set_running (false);
5433 /* If resuming the child, mark it running. */
5434 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5435 child
->set_running (true);
5437 /* In non-stop mode, also resume the other branch. */
5438 if (!detach_fork
&& (non_stop
5439 || (sched_multi
&& target_is_non_stop_p ())))
5442 switch_to_thread (parent
);
5444 switch_to_thread (child
);
5446 ecs
->event_thread
= inferior_thread ();
5447 ecs
->ptid
= inferior_ptid
;
5452 switch_to_thread (child
);
5454 switch_to_thread (parent
);
5456 ecs
->event_thread
= inferior_thread ();
5457 ecs
->ptid
= inferior_ptid
;
5465 process_event_stop_test (ecs
);
5468 case TARGET_WAITKIND_VFORK_DONE
:
5469 /* Done with the shared memory region. Re-insert breakpoints in
5470 the parent, and keep going. */
5472 context_switch (ecs
);
5474 current_inferior ()->waiting_for_vfork_done
= 0;
5475 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5477 if (handle_stop_requested (ecs
))
5480 /* This also takes care of reinserting breakpoints in the
5481 previously locked inferior. */
5485 case TARGET_WAITKIND_EXECD
:
5487 /* Note we can't read registers yet (the stop_pc), because we
5488 don't yet know the inferior's post-exec architecture.
5489 'stop_pc' is explicitly read below instead. */
5490 switch_to_thread_no_regs (ecs
->event_thread
);
5492 /* Do whatever is necessary to the parent branch of the vfork. */
5493 handle_vfork_child_exec_or_exit (1);
5495 /* This causes the eventpoints and symbol table to be reset.
5496 Must do this now, before trying to determine whether to
5498 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5500 /* In follow_exec we may have deleted the original thread and
5501 created a new one. Make sure that the event thread is the
5502 execd thread for that case (this is a nop otherwise). */
5503 ecs
->event_thread
= inferior_thread ();
5505 ecs
->event_thread
->suspend
.stop_pc
5506 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5508 ecs
->event_thread
->control
.stop_bpstat
5509 = bpstat_stop_status (get_current_regcache ()->aspace (),
5510 ecs
->event_thread
->suspend
.stop_pc
,
5511 ecs
->event_thread
, &ecs
->ws
);
5513 /* Note that this may be referenced from inside
5514 bpstat_stop_status above, through inferior_has_execd. */
5515 xfree (ecs
->ws
.value
.execd_pathname
);
5516 ecs
->ws
.value
.execd_pathname
= NULL
;
5518 if (handle_stop_requested (ecs
))
5521 /* If no catchpoint triggered for this, then keep going. */
5522 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5524 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5528 process_event_stop_test (ecs
);
5531 /* Be careful not to try to gather much state about a thread
5532 that's in a syscall. It's frequently a losing proposition. */
5533 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5534 /* Getting the current syscall number. */
5535 if (handle_syscall_event (ecs
) == 0)
5536 process_event_stop_test (ecs
);
5539 /* Before examining the threads further, step this thread to
5540 get it entirely out of the syscall. (We get notice of the
5541 event when the thread is just on the verge of exiting a
5542 syscall. Stepping one instruction seems to get it back
5544 case TARGET_WAITKIND_SYSCALL_RETURN
:
5545 if (handle_syscall_event (ecs
) == 0)
5546 process_event_stop_test (ecs
);
5549 case TARGET_WAITKIND_STOPPED
:
5550 handle_signal_stop (ecs
);
5553 case TARGET_WAITKIND_NO_HISTORY
:
5554 /* Reverse execution: target ran out of history info. */
5556 /* Switch to the stopped thread. */
5557 context_switch (ecs
);
5558 infrun_log_debug ("stopped");
5560 delete_just_stopped_threads_single_step_breakpoints ();
5561 ecs
->event_thread
->suspend
.stop_pc
5562 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5564 if (handle_stop_requested (ecs
))
5567 gdb::observers::no_history
.notify ();
5573 /* Restart threads back to what they were trying to do back when we
5574 paused them for an in-line step-over. The EVENT_THREAD thread is
5578 restart_threads (struct thread_info
*event_thread
)
5580 /* In case the instruction just stepped spawned a new thread. */
5581 update_thread_list ();
5583 for (thread_info
*tp
: all_non_exited_threads ())
5585 switch_to_thread_no_regs (tp
);
5587 if (tp
== event_thread
)
5589 infrun_log_debug ("restart threads: [%s] is event thread",
5590 target_pid_to_str (tp
->ptid
).c_str ());
5594 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5596 infrun_log_debug ("restart threads: [%s] not meant to be running",
5597 target_pid_to_str (tp
->ptid
).c_str ());
5603 infrun_log_debug ("restart threads: [%s] resumed",
5604 target_pid_to_str (tp
->ptid
).c_str ());
5605 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5609 if (thread_is_in_step_over_chain (tp
))
5611 infrun_log_debug ("restart threads: [%s] needs step-over",
5612 target_pid_to_str (tp
->ptid
).c_str ());
5613 gdb_assert (!tp
->resumed
);
5618 if (tp
->suspend
.waitstatus_pending_p
)
5620 infrun_log_debug ("restart threads: [%s] has pending status",
5621 target_pid_to_str (tp
->ptid
).c_str ());
5626 gdb_assert (!tp
->stop_requested
);
5628 /* If some thread needs to start a step-over at this point, it
5629 should still be in the step-over queue, and thus skipped
5631 if (thread_still_needs_step_over (tp
))
5633 internal_error (__FILE__
, __LINE__
,
5634 "thread [%s] needs a step-over, but not in "
5635 "step-over queue\n",
5636 target_pid_to_str (tp
->ptid
).c_str ());
5639 if (currently_stepping (tp
))
5641 infrun_log_debug ("restart threads: [%s] was stepping",
5642 target_pid_to_str (tp
->ptid
).c_str ());
5643 keep_going_stepped_thread (tp
);
5647 struct execution_control_state ecss
;
5648 struct execution_control_state
*ecs
= &ecss
;
5650 infrun_log_debug ("restart threads: [%s] continuing",
5651 target_pid_to_str (tp
->ptid
).c_str ());
5652 reset_ecs (ecs
, tp
);
5653 switch_to_thread (tp
);
5654 keep_going_pass_signal (ecs
);
5659 /* Callback for iterate_over_threads. Find a resumed thread that has
5660 a pending waitstatus. */
5663 resumed_thread_with_pending_status (struct thread_info
*tp
,
5667 && tp
->suspend
.waitstatus_pending_p
);
5670 /* Called when we get an event that may finish an in-line or
5671 out-of-line (displaced stepping) step-over started previously.
5672 Return true if the event is processed and we should go back to the
5673 event loop; false if the caller should continue processing the
5677 finish_step_over (struct execution_control_state
*ecs
)
5679 int had_step_over_info
;
5681 displaced_step_finish (ecs
->event_thread
,
5682 ecs
->event_thread
->suspend
.stop_signal
);
5684 had_step_over_info
= step_over_info_valid_p ();
5686 if (had_step_over_info
)
5688 /* If we're stepping over a breakpoint with all threads locked,
5689 then only the thread that was stepped should be reporting
5691 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5693 clear_step_over_info ();
5696 if (!target_is_non_stop_p ())
5699 /* Start a new step-over in another thread if there's one that
5703 /* If we were stepping over a breakpoint before, and haven't started
5704 a new in-line step-over sequence, then restart all other threads
5705 (except the event thread). We can't do this in all-stop, as then
5706 e.g., we wouldn't be able to issue any other remote packet until
5707 these other threads stop. */
5708 if (had_step_over_info
&& !step_over_info_valid_p ())
5710 struct thread_info
*pending
;
5712 /* If we only have threads with pending statuses, the restart
5713 below won't restart any thread and so nothing re-inserts the
5714 breakpoint we just stepped over. But we need it inserted
5715 when we later process the pending events, otherwise if
5716 another thread has a pending event for this breakpoint too,
5717 we'd discard its event (because the breakpoint that
5718 originally caused the event was no longer inserted). */
5719 context_switch (ecs
);
5720 insert_breakpoints ();
5722 restart_threads (ecs
->event_thread
);
5724 /* If we have events pending, go through handle_inferior_event
5725 again, picking up a pending event at random. This avoids
5726 thread starvation. */
5728 /* But not if we just stepped over a watchpoint in order to let
5729 the instruction execute so we can evaluate its expression.
5730 The set of watchpoints that triggered is recorded in the
5731 breakpoint objects themselves (see bp->watchpoint_triggered).
5732 If we processed another event first, that other event could
5733 clobber this info. */
5734 if (ecs
->event_thread
->stepping_over_watchpoint
)
5737 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5739 if (pending
!= NULL
)
5741 struct thread_info
*tp
= ecs
->event_thread
;
5742 struct regcache
*regcache
;
5744 infrun_log_debug ("found resumed threads with "
5745 "pending events, saving status");
5747 gdb_assert (pending
!= tp
);
5749 /* Record the event thread's event for later. */
5750 save_waitstatus (tp
, &ecs
->ws
);
5751 /* This was cleared early, by handle_inferior_event. Set it
5752 so this pending event is considered by
5756 gdb_assert (!tp
->executing
);
5758 regcache
= get_thread_regcache (tp
);
5759 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5761 infrun_log_debug ("saved stop_pc=%s for %s "
5762 "(currently_stepping=%d)\n",
5763 paddress (target_gdbarch (),
5764 tp
->suspend
.stop_pc
),
5765 target_pid_to_str (tp
->ptid
).c_str (),
5766 currently_stepping (tp
));
5768 /* This in-line step-over finished; clear this so we won't
5769 start a new one. This is what handle_signal_stop would
5770 do, if we returned false. */
5771 tp
->stepping_over_breakpoint
= 0;
5773 /* Wake up the event loop again. */
5774 mark_async_event_handler (infrun_async_inferior_event_token
);
5776 prepare_to_wait (ecs
);
5784 /* Come here when the program has stopped with a signal. */
5787 handle_signal_stop (struct execution_control_state
*ecs
)
5789 struct frame_info
*frame
;
5790 struct gdbarch
*gdbarch
;
5791 int stopped_by_watchpoint
;
5792 enum stop_kind stop_soon
;
5795 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5797 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5799 /* Do we need to clean up the state of a thread that has
5800 completed a displaced single-step? (Doing so usually affects
5801 the PC, so do it here, before we set stop_pc.) */
5802 if (finish_step_over (ecs
))
5805 /* If we either finished a single-step or hit a breakpoint, but
5806 the user wanted this thread to be stopped, pretend we got a
5807 SIG0 (generic unsignaled stop). */
5808 if (ecs
->event_thread
->stop_requested
5809 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5810 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5812 ecs
->event_thread
->suspend
.stop_pc
5813 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5817 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5818 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5820 switch_to_thread (ecs
->event_thread
);
5822 infrun_log_debug ("stop_pc=%s",
5823 paddress (reg_gdbarch
,
5824 ecs
->event_thread
->suspend
.stop_pc
));
5825 if (target_stopped_by_watchpoint ())
5829 infrun_log_debug ("stopped by watchpoint");
5831 if (target_stopped_data_address (current_top_target (), &addr
))
5832 infrun_log_debug ("stopped data address=%s",
5833 paddress (reg_gdbarch
, addr
));
5835 infrun_log_debug ("(no data address available)");
5839 /* This is originated from start_remote(), start_inferior() and
5840 shared libraries hook functions. */
5841 stop_soon
= get_inferior_stop_soon (ecs
);
5842 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5844 context_switch (ecs
);
5845 infrun_log_debug ("quietly stopped");
5846 stop_print_frame
= 1;
5851 /* This originates from attach_command(). We need to overwrite
5852 the stop_signal here, because some kernels don't ignore a
5853 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5854 See more comments in inferior.h. On the other hand, if we
5855 get a non-SIGSTOP, report it to the user - assume the backend
5856 will handle the SIGSTOP if it should show up later.
5858 Also consider that the attach is complete when we see a
5859 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5860 target extended-remote report it instead of a SIGSTOP
5861 (e.g. gdbserver). We already rely on SIGTRAP being our
5862 signal, so this is no exception.
5864 Also consider that the attach is complete when we see a
5865 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5866 the target to stop all threads of the inferior, in case the
5867 low level attach operation doesn't stop them implicitly. If
5868 they weren't stopped implicitly, then the stub will report a
5869 GDB_SIGNAL_0, meaning: stopped for no particular reason
5870 other than GDB's request. */
5871 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5872 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5873 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5874 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5876 stop_print_frame
= 1;
5878 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5882 /* See if something interesting happened to the non-current thread. If
5883 so, then switch to that thread. */
5884 if (ecs
->ptid
!= inferior_ptid
)
5886 infrun_log_debug ("context switch");
5888 context_switch (ecs
);
5890 if (deprecated_context_hook
)
5891 deprecated_context_hook (ecs
->event_thread
->global_num
);
5894 /* At this point, get hold of the now-current thread's frame. */
5895 frame
= get_current_frame ();
5896 gdbarch
= get_frame_arch (frame
);
5898 /* Pull the single step breakpoints out of the target. */
5899 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5901 struct regcache
*regcache
;
5904 regcache
= get_thread_regcache (ecs
->event_thread
);
5905 const address_space
*aspace
= regcache
->aspace ();
5907 pc
= regcache_read_pc (regcache
);
5909 /* However, before doing so, if this single-step breakpoint was
5910 actually for another thread, set this thread up for moving
5912 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5915 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5917 infrun_log_debug ("[%s] hit another thread's single-step "
5919 target_pid_to_str (ecs
->ptid
).c_str ());
5920 ecs
->hit_singlestep_breakpoint
= 1;
5925 infrun_log_debug ("[%s] hit its single-step breakpoint",
5926 target_pid_to_str (ecs
->ptid
).c_str ());
5929 delete_just_stopped_threads_single_step_breakpoints ();
5931 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5932 && ecs
->event_thread
->control
.trap_expected
5933 && ecs
->event_thread
->stepping_over_watchpoint
)
5934 stopped_by_watchpoint
= 0;
5936 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5938 /* If necessary, step over this watchpoint. We'll be back to display
5940 if (stopped_by_watchpoint
5941 && (target_have_steppable_watchpoint
5942 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5944 /* At this point, we are stopped at an instruction which has
5945 attempted to write to a piece of memory under control of
5946 a watchpoint. The instruction hasn't actually executed
5947 yet. If we were to evaluate the watchpoint expression
5948 now, we would get the old value, and therefore no change
5949 would seem to have occurred.
5951 In order to make watchpoints work `right', we really need
5952 to complete the memory write, and then evaluate the
5953 watchpoint expression. We do this by single-stepping the
5956 It may not be necessary to disable the watchpoint to step over
5957 it. For example, the PA can (with some kernel cooperation)
5958 single step over a watchpoint without disabling the watchpoint.
5960 It is far more common to need to disable a watchpoint to step
5961 the inferior over it. If we have non-steppable watchpoints,
5962 we must disable the current watchpoint; it's simplest to
5963 disable all watchpoints.
5965 Any breakpoint at PC must also be stepped over -- if there's
5966 one, it will have already triggered before the watchpoint
5967 triggered, and we either already reported it to the user, or
5968 it didn't cause a stop and we called keep_going. In either
5969 case, if there was a breakpoint at PC, we must be trying to
5971 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5976 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5977 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5978 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5979 ecs
->event_thread
->control
.stop_step
= 0;
5980 stop_print_frame
= 1;
5981 stopped_by_random_signal
= 0;
5982 bpstat stop_chain
= NULL
;
5984 /* Hide inlined functions starting here, unless we just performed stepi or
5985 nexti. After stepi and nexti, always show the innermost frame (not any
5986 inline function call sites). */
5987 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5989 const address_space
*aspace
5990 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5992 /* skip_inline_frames is expensive, so we avoid it if we can
5993 determine that the address is one where functions cannot have
5994 been inlined. This improves performance with inferiors that
5995 load a lot of shared libraries, because the solib event
5996 breakpoint is defined as the address of a function (i.e. not
5997 inline). Note that we have to check the previous PC as well
5998 as the current one to catch cases when we have just
5999 single-stepped off a breakpoint prior to reinstating it.
6000 Note that we're assuming that the code we single-step to is
6001 not inline, but that's not definitive: there's nothing
6002 preventing the event breakpoint function from containing
6003 inlined code, and the single-step ending up there. If the
6004 user had set a breakpoint on that inlined code, the missing
6005 skip_inline_frames call would break things. Fortunately
6006 that's an extremely unlikely scenario. */
6007 if (!pc_at_non_inline_function (aspace
,
6008 ecs
->event_thread
->suspend
.stop_pc
,
6010 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6011 && ecs
->event_thread
->control
.trap_expected
6012 && pc_at_non_inline_function (aspace
,
6013 ecs
->event_thread
->prev_pc
,
6016 stop_chain
= build_bpstat_chain (aspace
,
6017 ecs
->event_thread
->suspend
.stop_pc
,
6019 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6021 /* Re-fetch current thread's frame in case that invalidated
6023 frame
= get_current_frame ();
6024 gdbarch
= get_frame_arch (frame
);
6028 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6029 && ecs
->event_thread
->control
.trap_expected
6030 && gdbarch_single_step_through_delay_p (gdbarch
)
6031 && currently_stepping (ecs
->event_thread
))
6033 /* We're trying to step off a breakpoint. Turns out that we're
6034 also on an instruction that needs to be stepped multiple
6035 times before it's been fully executing. E.g., architectures
6036 with a delay slot. It needs to be stepped twice, once for
6037 the instruction and once for the delay slot. */
6038 int step_through_delay
6039 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6041 if (step_through_delay
)
6042 infrun_log_debug ("step through delay");
6044 if (ecs
->event_thread
->control
.step_range_end
== 0
6045 && step_through_delay
)
6047 /* The user issued a continue when stopped at a breakpoint.
6048 Set up for another trap and get out of here. */
6049 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6053 else if (step_through_delay
)
6055 /* The user issued a step when stopped at a breakpoint.
6056 Maybe we should stop, maybe we should not - the delay
6057 slot *might* correspond to a line of source. In any
6058 case, don't decide that here, just set
6059 ecs->stepping_over_breakpoint, making sure we
6060 single-step again before breakpoints are re-inserted. */
6061 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6065 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6066 handles this event. */
6067 ecs
->event_thread
->control
.stop_bpstat
6068 = bpstat_stop_status (get_current_regcache ()->aspace (),
6069 ecs
->event_thread
->suspend
.stop_pc
,
6070 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6072 /* Following in case break condition called a
6074 stop_print_frame
= 1;
6076 /* This is where we handle "moribund" watchpoints. Unlike
6077 software breakpoints traps, hardware watchpoint traps are
6078 always distinguishable from random traps. If no high-level
6079 watchpoint is associated with the reported stop data address
6080 anymore, then the bpstat does not explain the signal ---
6081 simply make sure to ignore it if `stopped_by_watchpoint' is
6084 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6085 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6087 && stopped_by_watchpoint
)
6089 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6093 /* NOTE: cagney/2003-03-29: These checks for a random signal
6094 at one stage in the past included checks for an inferior
6095 function call's call dummy's return breakpoint. The original
6096 comment, that went with the test, read:
6098 ``End of a stack dummy. Some systems (e.g. Sony news) give
6099 another signal besides SIGTRAP, so check here as well as
6102 If someone ever tries to get call dummys on a
6103 non-executable stack to work (where the target would stop
6104 with something like a SIGSEGV), then those tests might need
6105 to be re-instated. Given, however, that the tests were only
6106 enabled when momentary breakpoints were not being used, I
6107 suspect that it won't be the case.
6109 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6110 be necessary for call dummies on a non-executable stack on
6113 /* See if the breakpoints module can explain the signal. */
6115 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6116 ecs
->event_thread
->suspend
.stop_signal
);
6118 /* Maybe this was a trap for a software breakpoint that has since
6120 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6122 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6123 ecs
->event_thread
->suspend
.stop_pc
))
6125 struct regcache
*regcache
;
6128 /* Re-adjust PC to what the program would see if GDB was not
6130 regcache
= get_thread_regcache (ecs
->event_thread
);
6131 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6134 gdb::optional
<scoped_restore_tmpl
<int>>
6135 restore_operation_disable
;
6137 if (record_full_is_used ())
6138 restore_operation_disable
.emplace
6139 (record_full_gdb_operation_disable_set ());
6141 regcache_write_pc (regcache
,
6142 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6147 /* A delayed software breakpoint event. Ignore the trap. */
6148 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6153 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6154 has since been removed. */
6155 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6157 /* A delayed hardware breakpoint event. Ignore the trap. */
6158 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6163 /* If not, perhaps stepping/nexting can. */
6165 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6166 && currently_stepping (ecs
->event_thread
));
6168 /* Perhaps the thread hit a single-step breakpoint of _another_
6169 thread. Single-step breakpoints are transparent to the
6170 breakpoints module. */
6172 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6174 /* No? Perhaps we got a moribund watchpoint. */
6176 random_signal
= !stopped_by_watchpoint
;
6178 /* Always stop if the user explicitly requested this thread to
6180 if (ecs
->event_thread
->stop_requested
)
6183 infrun_log_debug ("user-requested stop");
6186 /* For the program's own signals, act according to
6187 the signal handling tables. */
6191 /* Signal not for debugging purposes. */
6192 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6193 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6195 infrun_log_debug ("random signal (%s)",
6196 gdb_signal_to_symbol_string (stop_signal
));
6198 stopped_by_random_signal
= 1;
6200 /* Always stop on signals if we're either just gaining control
6201 of the program, or the user explicitly requested this thread
6202 to remain stopped. */
6203 if (stop_soon
!= NO_STOP_QUIETLY
6204 || ecs
->event_thread
->stop_requested
6206 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6212 /* Notify observers the signal has "handle print" set. Note we
6213 returned early above if stopping; normal_stop handles the
6214 printing in that case. */
6215 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6217 /* The signal table tells us to print about this signal. */
6218 target_terminal::ours_for_output ();
6219 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6220 target_terminal::inferior ();
6223 /* Clear the signal if it should not be passed. */
6224 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6225 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6227 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6228 && ecs
->event_thread
->control
.trap_expected
6229 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6231 /* We were just starting a new sequence, attempting to
6232 single-step off of a breakpoint and expecting a SIGTRAP.
6233 Instead this signal arrives. This signal will take us out
6234 of the stepping range so GDB needs to remember to, when
6235 the signal handler returns, resume stepping off that
6237 /* To simplify things, "continue" is forced to use the same
6238 code paths as single-step - set a breakpoint at the
6239 signal return address and then, once hit, step off that
6241 infrun_log_debug ("signal arrived while stepping over breakpoint");
6243 insert_hp_step_resume_breakpoint_at_frame (frame
);
6244 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6245 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6246 ecs
->event_thread
->control
.trap_expected
= 0;
6248 /* If we were nexting/stepping some other thread, switch to
6249 it, so that we don't continue it, losing control. */
6250 if (!switch_back_to_stepped_thread (ecs
))
6255 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6256 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6258 || ecs
->event_thread
->control
.step_range_end
== 1)
6259 && frame_id_eq (get_stack_frame_id (frame
),
6260 ecs
->event_thread
->control
.step_stack_frame_id
)
6261 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6263 /* The inferior is about to take a signal that will take it
6264 out of the single step range. Set a breakpoint at the
6265 current PC (which is presumably where the signal handler
6266 will eventually return) and then allow the inferior to
6269 Note that this is only needed for a signal delivered
6270 while in the single-step range. Nested signals aren't a
6271 problem as they eventually all return. */
6272 infrun_log_debug ("signal may take us out of single-step range");
6274 clear_step_over_info ();
6275 insert_hp_step_resume_breakpoint_at_frame (frame
);
6276 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6277 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6278 ecs
->event_thread
->control
.trap_expected
= 0;
6283 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6284 when either there's a nested signal, or when there's a
6285 pending signal enabled just as the signal handler returns
6286 (leaving the inferior at the step-resume-breakpoint without
6287 actually executing it). Either way continue until the
6288 breakpoint is really hit. */
6290 if (!switch_back_to_stepped_thread (ecs
))
6292 infrun_log_debug ("random signal, keep going");
6299 process_event_stop_test (ecs
);
6302 /* Come here when we've got some debug event / signal we can explain
6303 (IOW, not a random signal), and test whether it should cause a
6304 stop, or whether we should resume the inferior (transparently).
6305 E.g., could be a breakpoint whose condition evaluates false; we
6306 could be still stepping within the line; etc. */
6309 process_event_stop_test (struct execution_control_state
*ecs
)
6311 struct symtab_and_line stop_pc_sal
;
6312 struct frame_info
*frame
;
6313 struct gdbarch
*gdbarch
;
6314 CORE_ADDR jmp_buf_pc
;
6315 struct bpstat_what what
;
6317 /* Handle cases caused by hitting a breakpoint. */
6319 frame
= get_current_frame ();
6320 gdbarch
= get_frame_arch (frame
);
6322 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6324 if (what
.call_dummy
)
6326 stop_stack_dummy
= what
.call_dummy
;
6329 /* A few breakpoint types have callbacks associated (e.g.,
6330 bp_jit_event). Run them now. */
6331 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6333 /* If we hit an internal event that triggers symbol changes, the
6334 current frame will be invalidated within bpstat_what (e.g., if we
6335 hit an internal solib event). Re-fetch it. */
6336 frame
= get_current_frame ();
6337 gdbarch
= get_frame_arch (frame
);
6339 switch (what
.main_action
)
6341 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6342 /* If we hit the breakpoint at longjmp while stepping, we
6343 install a momentary breakpoint at the target of the
6346 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6348 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6350 if (what
.is_longjmp
)
6352 struct value
*arg_value
;
6354 /* If we set the longjmp breakpoint via a SystemTap probe,
6355 then use it to extract the arguments. The destination PC
6356 is the third argument to the probe. */
6357 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6360 jmp_buf_pc
= value_as_address (arg_value
);
6361 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6363 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6364 || !gdbarch_get_longjmp_target (gdbarch
,
6365 frame
, &jmp_buf_pc
))
6367 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6368 "(!gdbarch_get_longjmp_target)");
6373 /* Insert a breakpoint at resume address. */
6374 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6377 check_exception_resume (ecs
, frame
);
6381 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6383 struct frame_info
*init_frame
;
6385 /* There are several cases to consider.
6387 1. The initiating frame no longer exists. In this case we
6388 must stop, because the exception or longjmp has gone too
6391 2. The initiating frame exists, and is the same as the
6392 current frame. We stop, because the exception or longjmp
6395 3. The initiating frame exists and is different from the
6396 current frame. This means the exception or longjmp has
6397 been caught beneath the initiating frame, so keep going.
6399 4. longjmp breakpoint has been placed just to protect
6400 against stale dummy frames and user is not interested in
6401 stopping around longjmps. */
6403 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6405 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6407 delete_exception_resume_breakpoint (ecs
->event_thread
);
6409 if (what
.is_longjmp
)
6411 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6413 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6421 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6425 struct frame_id current_id
6426 = get_frame_id (get_current_frame ());
6427 if (frame_id_eq (current_id
,
6428 ecs
->event_thread
->initiating_frame
))
6430 /* Case 2. Fall through. */
6440 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6442 delete_step_resume_breakpoint (ecs
->event_thread
);
6444 end_stepping_range (ecs
);
6448 case BPSTAT_WHAT_SINGLE
:
6449 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6450 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6451 /* Still need to check other stuff, at least the case where we
6452 are stepping and step out of the right range. */
6455 case BPSTAT_WHAT_STEP_RESUME
:
6456 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6458 delete_step_resume_breakpoint (ecs
->event_thread
);
6459 if (ecs
->event_thread
->control
.proceed_to_finish
6460 && execution_direction
== EXEC_REVERSE
)
6462 struct thread_info
*tp
= ecs
->event_thread
;
6464 /* We are finishing a function in reverse, and just hit the
6465 step-resume breakpoint at the start address of the
6466 function, and we're almost there -- just need to back up
6467 by one more single-step, which should take us back to the
6469 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6473 fill_in_stop_func (gdbarch
, ecs
);
6474 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6475 && execution_direction
== EXEC_REVERSE
)
6477 /* We are stepping over a function call in reverse, and just
6478 hit the step-resume breakpoint at the start address of
6479 the function. Go back to single-stepping, which should
6480 take us back to the function call. */
6481 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6487 case BPSTAT_WHAT_STOP_NOISY
:
6488 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6489 stop_print_frame
= 1;
6491 /* Assume the thread stopped for a breapoint. We'll still check
6492 whether a/the breakpoint is there when the thread is next
6494 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6499 case BPSTAT_WHAT_STOP_SILENT
:
6500 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6501 stop_print_frame
= 0;
6503 /* Assume the thread stopped for a breapoint. We'll still check
6504 whether a/the breakpoint is there when the thread is next
6506 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6510 case BPSTAT_WHAT_HP_STEP_RESUME
:
6511 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6513 delete_step_resume_breakpoint (ecs
->event_thread
);
6514 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6516 /* Back when the step-resume breakpoint was inserted, we
6517 were trying to single-step off a breakpoint. Go back to
6519 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6520 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6526 case BPSTAT_WHAT_KEEP_CHECKING
:
6530 /* If we stepped a permanent breakpoint and we had a high priority
6531 step-resume breakpoint for the address we stepped, but we didn't
6532 hit it, then we must have stepped into the signal handler. The
6533 step-resume was only necessary to catch the case of _not_
6534 stepping into the handler, so delete it, and fall through to
6535 checking whether the step finished. */
6536 if (ecs
->event_thread
->stepped_breakpoint
)
6538 struct breakpoint
*sr_bp
6539 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6542 && sr_bp
->loc
->permanent
6543 && sr_bp
->type
== bp_hp_step_resume
6544 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6546 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6547 delete_step_resume_breakpoint (ecs
->event_thread
);
6548 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6552 /* We come here if we hit a breakpoint but should not stop for it.
6553 Possibly we also were stepping and should stop for that. So fall
6554 through and test for stepping. But, if not stepping, do not
6557 /* In all-stop mode, if we're currently stepping but have stopped in
6558 some other thread, we need to switch back to the stepped thread. */
6559 if (switch_back_to_stepped_thread (ecs
))
6562 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6564 infrun_log_debug ("step-resume breakpoint is inserted");
6566 /* Having a step-resume breakpoint overrides anything
6567 else having to do with stepping commands until
6568 that breakpoint is reached. */
6573 if (ecs
->event_thread
->control
.step_range_end
== 0)
6575 infrun_log_debug ("no stepping, continue");
6576 /* Likewise if we aren't even stepping. */
6581 /* Re-fetch current thread's frame in case the code above caused
6582 the frame cache to be re-initialized, making our FRAME variable
6583 a dangling pointer. */
6584 frame
= get_current_frame ();
6585 gdbarch
= get_frame_arch (frame
);
6586 fill_in_stop_func (gdbarch
, ecs
);
6588 /* If stepping through a line, keep going if still within it.
6590 Note that step_range_end is the address of the first instruction
6591 beyond the step range, and NOT the address of the last instruction
6594 Note also that during reverse execution, we may be stepping
6595 through a function epilogue and therefore must detect when
6596 the current-frame changes in the middle of a line. */
6598 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6600 && (execution_direction
!= EXEC_REVERSE
6601 || frame_id_eq (get_frame_id (frame
),
6602 ecs
->event_thread
->control
.step_frame_id
)))
6605 ("stepping inside range [%s-%s]",
6606 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6607 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6609 /* Tentatively re-enable range stepping; `resume' disables it if
6610 necessary (e.g., if we're stepping over a breakpoint or we
6611 have software watchpoints). */
6612 ecs
->event_thread
->control
.may_range_step
= 1;
6614 /* When stepping backward, stop at beginning of line range
6615 (unless it's the function entry point, in which case
6616 keep going back to the call point). */
6617 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6618 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6619 && stop_pc
!= ecs
->stop_func_start
6620 && execution_direction
== EXEC_REVERSE
)
6621 end_stepping_range (ecs
);
6628 /* We stepped out of the stepping range. */
6630 /* If we are stepping at the source level and entered the runtime
6631 loader dynamic symbol resolution code...
6633 EXEC_FORWARD: we keep on single stepping until we exit the run
6634 time loader code and reach the callee's address.
6636 EXEC_REVERSE: we've already executed the callee (backward), and
6637 the runtime loader code is handled just like any other
6638 undebuggable function call. Now we need only keep stepping
6639 backward through the trampoline code, and that's handled further
6640 down, so there is nothing for us to do here. */
6642 if (execution_direction
!= EXEC_REVERSE
6643 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6644 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6646 CORE_ADDR pc_after_resolver
=
6647 gdbarch_skip_solib_resolver (gdbarch
,
6648 ecs
->event_thread
->suspend
.stop_pc
);
6650 infrun_log_debug ("stepped into dynsym resolve code");
6652 if (pc_after_resolver
)
6654 /* Set up a step-resume breakpoint at the address
6655 indicated by SKIP_SOLIB_RESOLVER. */
6656 symtab_and_line sr_sal
;
6657 sr_sal
.pc
= pc_after_resolver
;
6658 sr_sal
.pspace
= get_frame_program_space (frame
);
6660 insert_step_resume_breakpoint_at_sal (gdbarch
,
6661 sr_sal
, null_frame_id
);
6668 /* Step through an indirect branch thunk. */
6669 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6670 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6671 ecs
->event_thread
->suspend
.stop_pc
))
6673 infrun_log_debug ("stepped into indirect branch thunk");
6678 if (ecs
->event_thread
->control
.step_range_end
!= 1
6679 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6680 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6681 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6683 infrun_log_debug ("stepped into signal trampoline");
6684 /* The inferior, while doing a "step" or "next", has ended up in
6685 a signal trampoline (either by a signal being delivered or by
6686 the signal handler returning). Just single-step until the
6687 inferior leaves the trampoline (either by calling the handler
6693 /* If we're in the return path from a shared library trampoline,
6694 we want to proceed through the trampoline when stepping. */
6695 /* macro/2012-04-25: This needs to come before the subroutine
6696 call check below as on some targets return trampolines look
6697 like subroutine calls (MIPS16 return thunks). */
6698 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6699 ecs
->event_thread
->suspend
.stop_pc
,
6700 ecs
->stop_func_name
)
6701 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6703 /* Determine where this trampoline returns. */
6704 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6705 CORE_ADDR real_stop_pc
6706 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6708 infrun_log_debug ("stepped into solib return tramp");
6710 /* Only proceed through if we know where it's going. */
6713 /* And put the step-breakpoint there and go until there. */
6714 symtab_and_line sr_sal
;
6715 sr_sal
.pc
= real_stop_pc
;
6716 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6717 sr_sal
.pspace
= get_frame_program_space (frame
);
6719 /* Do not specify what the fp should be when we stop since
6720 on some machines the prologue is where the new fp value
6722 insert_step_resume_breakpoint_at_sal (gdbarch
,
6723 sr_sal
, null_frame_id
);
6725 /* Restart without fiddling with the step ranges or
6732 /* Check for subroutine calls. The check for the current frame
6733 equalling the step ID is not necessary - the check of the
6734 previous frame's ID is sufficient - but it is a common case and
6735 cheaper than checking the previous frame's ID.
6737 NOTE: frame_id_eq will never report two invalid frame IDs as
6738 being equal, so to get into this block, both the current and
6739 previous frame must have valid frame IDs. */
6740 /* The outer_frame_id check is a heuristic to detect stepping
6741 through startup code. If we step over an instruction which
6742 sets the stack pointer from an invalid value to a valid value,
6743 we may detect that as a subroutine call from the mythical
6744 "outermost" function. This could be fixed by marking
6745 outermost frames as !stack_p,code_p,special_p. Then the
6746 initial outermost frame, before sp was valid, would
6747 have code_addr == &_start. See the comment in frame_id_eq
6749 if (!frame_id_eq (get_stack_frame_id (frame
),
6750 ecs
->event_thread
->control
.step_stack_frame_id
)
6751 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6752 ecs
->event_thread
->control
.step_stack_frame_id
)
6753 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6755 || (ecs
->event_thread
->control
.step_start_function
6756 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6758 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6759 CORE_ADDR real_stop_pc
;
6761 infrun_log_debug ("stepped into subroutine");
6763 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6765 /* I presume that step_over_calls is only 0 when we're
6766 supposed to be stepping at the assembly language level
6767 ("stepi"). Just stop. */
6768 /* And this works the same backward as frontward. MVS */
6769 end_stepping_range (ecs
);
6773 /* Reverse stepping through solib trampolines. */
6775 if (execution_direction
== EXEC_REVERSE
6776 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6777 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6778 || (ecs
->stop_func_start
== 0
6779 && in_solib_dynsym_resolve_code (stop_pc
))))
6781 /* Any solib trampoline code can be handled in reverse
6782 by simply continuing to single-step. We have already
6783 executed the solib function (backwards), and a few
6784 steps will take us back through the trampoline to the
6790 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6792 /* We're doing a "next".
6794 Normal (forward) execution: set a breakpoint at the
6795 callee's return address (the address at which the caller
6798 Reverse (backward) execution. set the step-resume
6799 breakpoint at the start of the function that we just
6800 stepped into (backwards), and continue to there. When we
6801 get there, we'll need to single-step back to the caller. */
6803 if (execution_direction
== EXEC_REVERSE
)
6805 /* If we're already at the start of the function, we've either
6806 just stepped backward into a single instruction function,
6807 or stepped back out of a signal handler to the first instruction
6808 of the function. Just keep going, which will single-step back
6810 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6812 /* Normal function call return (static or dynamic). */
6813 symtab_and_line sr_sal
;
6814 sr_sal
.pc
= ecs
->stop_func_start
;
6815 sr_sal
.pspace
= get_frame_program_space (frame
);
6816 insert_step_resume_breakpoint_at_sal (gdbarch
,
6817 sr_sal
, null_frame_id
);
6821 insert_step_resume_breakpoint_at_caller (frame
);
6827 /* If we are in a function call trampoline (a stub between the
6828 calling routine and the real function), locate the real
6829 function. That's what tells us (a) whether we want to step
6830 into it at all, and (b) what prologue we want to run to the
6831 end of, if we do step into it. */
6832 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6833 if (real_stop_pc
== 0)
6834 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6835 if (real_stop_pc
!= 0)
6836 ecs
->stop_func_start
= real_stop_pc
;
6838 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6840 symtab_and_line sr_sal
;
6841 sr_sal
.pc
= ecs
->stop_func_start
;
6842 sr_sal
.pspace
= get_frame_program_space (frame
);
6844 insert_step_resume_breakpoint_at_sal (gdbarch
,
6845 sr_sal
, null_frame_id
);
6850 /* If we have line number information for the function we are
6851 thinking of stepping into and the function isn't on the skip
6854 If there are several symtabs at that PC (e.g. with include
6855 files), just want to know whether *any* of them have line
6856 numbers. find_pc_line handles this. */
6858 struct symtab_and_line tmp_sal
;
6860 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6861 if (tmp_sal
.line
!= 0
6862 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6864 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6866 if (execution_direction
== EXEC_REVERSE
)
6867 handle_step_into_function_backward (gdbarch
, ecs
);
6869 handle_step_into_function (gdbarch
, ecs
);
6874 /* If we have no line number and the step-stop-if-no-debug is
6875 set, we stop the step so that the user has a chance to switch
6876 in assembly mode. */
6877 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6878 && step_stop_if_no_debug
)
6880 end_stepping_range (ecs
);
6884 if (execution_direction
== EXEC_REVERSE
)
6886 /* If we're already at the start of the function, we've either just
6887 stepped backward into a single instruction function without line
6888 number info, or stepped back out of a signal handler to the first
6889 instruction of the function without line number info. Just keep
6890 going, which will single-step back to the caller. */
6891 if (ecs
->stop_func_start
!= stop_pc
)
6893 /* Set a breakpoint at callee's start address.
6894 From there we can step once and be back in the caller. */
6895 symtab_and_line sr_sal
;
6896 sr_sal
.pc
= ecs
->stop_func_start
;
6897 sr_sal
.pspace
= get_frame_program_space (frame
);
6898 insert_step_resume_breakpoint_at_sal (gdbarch
,
6899 sr_sal
, null_frame_id
);
6903 /* Set a breakpoint at callee's return address (the address
6904 at which the caller will resume). */
6905 insert_step_resume_breakpoint_at_caller (frame
);
6911 /* Reverse stepping through solib trampolines. */
6913 if (execution_direction
== EXEC_REVERSE
6914 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6916 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6918 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6919 || (ecs
->stop_func_start
== 0
6920 && in_solib_dynsym_resolve_code (stop_pc
)))
6922 /* Any solib trampoline code can be handled in reverse
6923 by simply continuing to single-step. We have already
6924 executed the solib function (backwards), and a few
6925 steps will take us back through the trampoline to the
6930 else if (in_solib_dynsym_resolve_code (stop_pc
))
6932 /* Stepped backward into the solib dynsym resolver.
6933 Set a breakpoint at its start and continue, then
6934 one more step will take us out. */
6935 symtab_and_line sr_sal
;
6936 sr_sal
.pc
= ecs
->stop_func_start
;
6937 sr_sal
.pspace
= get_frame_program_space (frame
);
6938 insert_step_resume_breakpoint_at_sal (gdbarch
,
6939 sr_sal
, null_frame_id
);
6945 /* This always returns the sal for the inner-most frame when we are in a
6946 stack of inlined frames, even if GDB actually believes that it is in a
6947 more outer frame. This is checked for below by calls to
6948 inline_skipped_frames. */
6949 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6951 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6952 the trampoline processing logic, however, there are some trampolines
6953 that have no names, so we should do trampoline handling first. */
6954 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6955 && ecs
->stop_func_name
== NULL
6956 && stop_pc_sal
.line
== 0)
6958 infrun_log_debug ("stepped into undebuggable function");
6960 /* The inferior just stepped into, or returned to, an
6961 undebuggable function (where there is no debugging information
6962 and no line number corresponding to the address where the
6963 inferior stopped). Since we want to skip this kind of code,
6964 we keep going until the inferior returns from this
6965 function - unless the user has asked us not to (via
6966 set step-mode) or we no longer know how to get back
6967 to the call site. */
6968 if (step_stop_if_no_debug
6969 || !frame_id_p (frame_unwind_caller_id (frame
)))
6971 /* If we have no line number and the step-stop-if-no-debug
6972 is set, we stop the step so that the user has a chance to
6973 switch in assembly mode. */
6974 end_stepping_range (ecs
);
6979 /* Set a breakpoint at callee's return address (the address
6980 at which the caller will resume). */
6981 insert_step_resume_breakpoint_at_caller (frame
);
6987 if (ecs
->event_thread
->control
.step_range_end
== 1)
6989 /* It is stepi or nexti. We always want to stop stepping after
6991 infrun_log_debug ("stepi/nexti");
6992 end_stepping_range (ecs
);
6996 if (stop_pc_sal
.line
== 0)
6998 /* We have no line number information. That means to stop
6999 stepping (does this always happen right after one instruction,
7000 when we do "s" in a function with no line numbers,
7001 or can this happen as a result of a return or longjmp?). */
7002 infrun_log_debug ("line number info");
7003 end_stepping_range (ecs
);
7007 /* Look for "calls" to inlined functions, part one. If the inline
7008 frame machinery detected some skipped call sites, we have entered
7009 a new inline function. */
7011 if (frame_id_eq (get_frame_id (get_current_frame ()),
7012 ecs
->event_thread
->control
.step_frame_id
)
7013 && inline_skipped_frames (ecs
->event_thread
))
7015 infrun_log_debug ("stepped into inlined function");
7017 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7019 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7021 /* For "step", we're going to stop. But if the call site
7022 for this inlined function is on the same source line as
7023 we were previously stepping, go down into the function
7024 first. Otherwise stop at the call site. */
7026 if (call_sal
.line
== ecs
->event_thread
->current_line
7027 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7029 step_into_inline_frame (ecs
->event_thread
);
7030 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7037 end_stepping_range (ecs
);
7042 /* For "next", we should stop at the call site if it is on a
7043 different source line. Otherwise continue through the
7044 inlined function. */
7045 if (call_sal
.line
== ecs
->event_thread
->current_line
7046 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7049 end_stepping_range (ecs
);
7054 /* Look for "calls" to inlined functions, part two. If we are still
7055 in the same real function we were stepping through, but we have
7056 to go further up to find the exact frame ID, we are stepping
7057 through a more inlined call beyond its call site. */
7059 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7060 && !frame_id_eq (get_frame_id (get_current_frame ()),
7061 ecs
->event_thread
->control
.step_frame_id
)
7062 && stepped_in_from (get_current_frame (),
7063 ecs
->event_thread
->control
.step_frame_id
))
7065 infrun_log_debug ("stepping through inlined function");
7067 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7068 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7071 end_stepping_range (ecs
);
7075 bool refresh_step_info
= true;
7076 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7077 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7078 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7080 if (stop_pc_sal
.is_stmt
)
7082 /* We are at the start of a different line. So stop. Note that
7083 we don't stop if we step into the middle of a different line.
7084 That is said to make things like for (;;) statements work
7086 infrun_log_debug ("infrun: stepped to a different line\n");
7087 end_stepping_range (ecs
);
7090 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7091 ecs
->event_thread
->control
.step_frame_id
))
7093 /* We are at the start of a different line, however, this line is
7094 not marked as a statement, and we have not changed frame. We
7095 ignore this line table entry, and continue stepping forward,
7096 looking for a better place to stop. */
7097 refresh_step_info
= false;
7098 infrun_log_debug ("infrun: stepped to a different line, but "
7099 "it's not the start of a statement\n");
7103 /* We aren't done stepping.
7105 Optimize by setting the stepping range to the line.
7106 (We might not be in the original line, but if we entered a
7107 new line in mid-statement, we continue stepping. This makes
7108 things like for(;;) statements work better.)
7110 If we entered a SAL that indicates a non-statement line table entry,
7111 then we update the stepping range, but we don't update the step info,
7112 which includes things like the line number we are stepping away from.
7113 This means we will stop when we find a line table entry that is marked
7114 as is-statement, even if it matches the non-statement one we just
7117 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7118 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7119 ecs
->event_thread
->control
.may_range_step
= 1;
7120 if (refresh_step_info
)
7121 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7123 infrun_log_debug ("keep going");
7127 /* In all-stop mode, if we're currently stepping but have stopped in
7128 some other thread, we may need to switch back to the stepped
7129 thread. Returns true we set the inferior running, false if we left
7130 it stopped (and the event needs further processing). */
7133 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7135 if (!target_is_non_stop_p ())
7137 struct thread_info
*stepping_thread
;
7139 /* If any thread is blocked on some internal breakpoint, and we
7140 simply need to step over that breakpoint to get it going
7141 again, do that first. */
7143 /* However, if we see an event for the stepping thread, then we
7144 know all other threads have been moved past their breakpoints
7145 already. Let the caller check whether the step is finished,
7146 etc., before deciding to move it past a breakpoint. */
7147 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7150 /* Check if the current thread is blocked on an incomplete
7151 step-over, interrupted by a random signal. */
7152 if (ecs
->event_thread
->control
.trap_expected
7153 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7155 infrun_log_debug ("need to finish step-over of [%s]",
7156 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7161 /* Check if the current thread is blocked by a single-step
7162 breakpoint of another thread. */
7163 if (ecs
->hit_singlestep_breakpoint
)
7165 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7166 target_pid_to_str (ecs
->ptid
).c_str ());
7171 /* If this thread needs yet another step-over (e.g., stepping
7172 through a delay slot), do it first before moving on to
7174 if (thread_still_needs_step_over (ecs
->event_thread
))
7177 ("thread [%s] still needs step-over",
7178 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7183 /* If scheduler locking applies even if not stepping, there's no
7184 need to walk over threads. Above we've checked whether the
7185 current thread is stepping. If some other thread not the
7186 event thread is stepping, then it must be that scheduler
7187 locking is not in effect. */
7188 if (schedlock_applies (ecs
->event_thread
))
7191 /* Otherwise, we no longer expect a trap in the current thread.
7192 Clear the trap_expected flag before switching back -- this is
7193 what keep_going does as well, if we call it. */
7194 ecs
->event_thread
->control
.trap_expected
= 0;
7196 /* Likewise, clear the signal if it should not be passed. */
7197 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7198 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7200 /* Do all pending step-overs before actually proceeding with
7202 if (start_step_over ())
7204 prepare_to_wait (ecs
);
7208 /* Look for the stepping/nexting thread. */
7209 stepping_thread
= NULL
;
7211 for (thread_info
*tp
: all_non_exited_threads ())
7213 switch_to_thread_no_regs (tp
);
7215 /* Ignore threads of processes the caller is not
7218 && (tp
->inf
->process_target () != ecs
->target
7219 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7222 /* When stepping over a breakpoint, we lock all threads
7223 except the one that needs to move past the breakpoint.
7224 If a non-event thread has this set, the "incomplete
7225 step-over" check above should have caught it earlier. */
7226 if (tp
->control
.trap_expected
)
7228 internal_error (__FILE__
, __LINE__
,
7229 "[%s] has inconsistent state: "
7230 "trap_expected=%d\n",
7231 target_pid_to_str (tp
->ptid
).c_str (),
7232 tp
->control
.trap_expected
);
7235 /* Did we find the stepping thread? */
7236 if (tp
->control
.step_range_end
)
7238 /* Yep. There should only one though. */
7239 gdb_assert (stepping_thread
== NULL
);
7241 /* The event thread is handled at the top, before we
7243 gdb_assert (tp
!= ecs
->event_thread
);
7245 /* If some thread other than the event thread is
7246 stepping, then scheduler locking can't be in effect,
7247 otherwise we wouldn't have resumed the current event
7248 thread in the first place. */
7249 gdb_assert (!schedlock_applies (tp
));
7251 stepping_thread
= tp
;
7255 if (stepping_thread
!= NULL
)
7257 infrun_log_debug ("switching back to stepped thread");
7259 if (keep_going_stepped_thread (stepping_thread
))
7261 prepare_to_wait (ecs
);
7266 switch_to_thread (ecs
->event_thread
);
7272 /* Set a previously stepped thread back to stepping. Returns true on
7273 success, false if the resume is not possible (e.g., the thread
7277 keep_going_stepped_thread (struct thread_info
*tp
)
7279 struct frame_info
*frame
;
7280 struct execution_control_state ecss
;
7281 struct execution_control_state
*ecs
= &ecss
;
7283 /* If the stepping thread exited, then don't try to switch back and
7284 resume it, which could fail in several different ways depending
7285 on the target. Instead, just keep going.
7287 We can find a stepping dead thread in the thread list in two
7290 - The target supports thread exit events, and when the target
7291 tries to delete the thread from the thread list, inferior_ptid
7292 pointed at the exiting thread. In such case, calling
7293 delete_thread does not really remove the thread from the list;
7294 instead, the thread is left listed, with 'exited' state.
7296 - The target's debug interface does not support thread exit
7297 events, and so we have no idea whatsoever if the previously
7298 stepping thread is still alive. For that reason, we need to
7299 synchronously query the target now. */
7301 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7303 infrun_log_debug ("not resuming previously stepped thread, it has "
7310 infrun_log_debug ("resuming previously stepped thread");
7312 reset_ecs (ecs
, tp
);
7313 switch_to_thread (tp
);
7315 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7316 frame
= get_current_frame ();
7318 /* If the PC of the thread we were trying to single-step has
7319 changed, then that thread has trapped or been signaled, but the
7320 event has not been reported to GDB yet. Re-poll the target
7321 looking for this particular thread's event (i.e. temporarily
7322 enable schedlock) by:
7324 - setting a break at the current PC
7325 - resuming that particular thread, only (by setting trap
7328 This prevents us continuously moving the single-step breakpoint
7329 forward, one instruction at a time, overstepping. */
7331 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7335 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7336 paddress (target_gdbarch (), tp
->prev_pc
),
7337 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7339 /* Clear the info of the previous step-over, as it's no longer
7340 valid (if the thread was trying to step over a breakpoint, it
7341 has already succeeded). It's what keep_going would do too,
7342 if we called it. Do this before trying to insert the sss
7343 breakpoint, otherwise if we were previously trying to step
7344 over this exact address in another thread, the breakpoint is
7346 clear_step_over_info ();
7347 tp
->control
.trap_expected
= 0;
7349 insert_single_step_breakpoint (get_frame_arch (frame
),
7350 get_frame_address_space (frame
),
7351 tp
->suspend
.stop_pc
);
7354 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7355 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7359 infrun_log_debug ("expected thread still hasn't advanced");
7361 keep_going_pass_signal (ecs
);
7366 /* Is thread TP in the middle of (software or hardware)
7367 single-stepping? (Note the result of this function must never be
7368 passed directly as target_resume's STEP parameter.) */
7371 currently_stepping (struct thread_info
*tp
)
7373 return ((tp
->control
.step_range_end
7374 && tp
->control
.step_resume_breakpoint
== NULL
)
7375 || tp
->control
.trap_expected
7376 || tp
->stepped_breakpoint
7377 || bpstat_should_step ());
7380 /* Inferior has stepped into a subroutine call with source code that
7381 we should not step over. Do step to the first line of code in
7385 handle_step_into_function (struct gdbarch
*gdbarch
,
7386 struct execution_control_state
*ecs
)
7388 fill_in_stop_func (gdbarch
, ecs
);
7390 compunit_symtab
*cust
7391 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7392 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7393 ecs
->stop_func_start
7394 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7396 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7397 /* Use the step_resume_break to step until the end of the prologue,
7398 even if that involves jumps (as it seems to on the vax under
7400 /* If the prologue ends in the middle of a source line, continue to
7401 the end of that source line (if it is still within the function).
7402 Otherwise, just go to end of prologue. */
7403 if (stop_func_sal
.end
7404 && stop_func_sal
.pc
!= ecs
->stop_func_start
7405 && stop_func_sal
.end
< ecs
->stop_func_end
)
7406 ecs
->stop_func_start
= stop_func_sal
.end
;
7408 /* Architectures which require breakpoint adjustment might not be able
7409 to place a breakpoint at the computed address. If so, the test
7410 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7411 ecs->stop_func_start to an address at which a breakpoint may be
7412 legitimately placed.
7414 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7415 made, GDB will enter an infinite loop when stepping through
7416 optimized code consisting of VLIW instructions which contain
7417 subinstructions corresponding to different source lines. On
7418 FR-V, it's not permitted to place a breakpoint on any but the
7419 first subinstruction of a VLIW instruction. When a breakpoint is
7420 set, GDB will adjust the breakpoint address to the beginning of
7421 the VLIW instruction. Thus, we need to make the corresponding
7422 adjustment here when computing the stop address. */
7424 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7426 ecs
->stop_func_start
7427 = gdbarch_adjust_breakpoint_address (gdbarch
,
7428 ecs
->stop_func_start
);
7431 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7433 /* We are already there: stop now. */
7434 end_stepping_range (ecs
);
7439 /* Put the step-breakpoint there and go until there. */
7440 symtab_and_line sr_sal
;
7441 sr_sal
.pc
= ecs
->stop_func_start
;
7442 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7443 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7445 /* Do not specify what the fp should be when we stop since on
7446 some machines the prologue is where the new fp value is
7448 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7450 /* And make sure stepping stops right away then. */
7451 ecs
->event_thread
->control
.step_range_end
7452 = ecs
->event_thread
->control
.step_range_start
;
7457 /* Inferior has stepped backward into a subroutine call with source
7458 code that we should not step over. Do step to the beginning of the
7459 last line of code in it. */
7462 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7463 struct execution_control_state
*ecs
)
7465 struct compunit_symtab
*cust
;
7466 struct symtab_and_line stop_func_sal
;
7468 fill_in_stop_func (gdbarch
, ecs
);
7470 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7471 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7472 ecs
->stop_func_start
7473 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7475 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7477 /* OK, we're just going to keep stepping here. */
7478 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7480 /* We're there already. Just stop stepping now. */
7481 end_stepping_range (ecs
);
7485 /* Else just reset the step range and keep going.
7486 No step-resume breakpoint, they don't work for
7487 epilogues, which can have multiple entry paths. */
7488 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7489 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7495 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7496 This is used to both functions and to skip over code. */
7499 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7500 struct symtab_and_line sr_sal
,
7501 struct frame_id sr_id
,
7502 enum bptype sr_type
)
7504 /* There should never be more than one step-resume or longjmp-resume
7505 breakpoint per thread, so we should never be setting a new
7506 step_resume_breakpoint when one is already active. */
7507 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7508 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7510 infrun_log_debug ("inserting step-resume breakpoint at %s",
7511 paddress (gdbarch
, sr_sal
.pc
));
7513 inferior_thread ()->control
.step_resume_breakpoint
7514 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7518 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7519 struct symtab_and_line sr_sal
,
7520 struct frame_id sr_id
)
7522 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7527 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7528 This is used to skip a potential signal handler.
7530 This is called with the interrupted function's frame. The signal
7531 handler, when it returns, will resume the interrupted function at
7535 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7537 gdb_assert (return_frame
!= NULL
);
7539 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7541 symtab_and_line sr_sal
;
7542 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7543 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7544 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7546 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7547 get_stack_frame_id (return_frame
),
7551 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7552 is used to skip a function after stepping into it (for "next" or if
7553 the called function has no debugging information).
7555 The current function has almost always been reached by single
7556 stepping a call or return instruction. NEXT_FRAME belongs to the
7557 current function, and the breakpoint will be set at the caller's
7560 This is a separate function rather than reusing
7561 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7562 get_prev_frame, which may stop prematurely (see the implementation
7563 of frame_unwind_caller_id for an example). */
7566 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7568 /* We shouldn't have gotten here if we don't know where the call site
7570 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7572 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7574 symtab_and_line sr_sal
;
7575 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7576 frame_unwind_caller_pc (next_frame
));
7577 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7578 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7580 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7581 frame_unwind_caller_id (next_frame
));
7584 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7585 new breakpoint at the target of a jmp_buf. The handling of
7586 longjmp-resume uses the same mechanisms used for handling
7587 "step-resume" breakpoints. */
7590 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7592 /* There should never be more than one longjmp-resume breakpoint per
7593 thread, so we should never be setting a new
7594 longjmp_resume_breakpoint when one is already active. */
7595 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7597 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7598 paddress (gdbarch
, pc
));
7600 inferior_thread ()->control
.exception_resume_breakpoint
=
7601 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7604 /* Insert an exception resume breakpoint. TP is the thread throwing
7605 the exception. The block B is the block of the unwinder debug hook
7606 function. FRAME is the frame corresponding to the call to this
7607 function. SYM is the symbol of the function argument holding the
7608 target PC of the exception. */
7611 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7612 const struct block
*b
,
7613 struct frame_info
*frame
,
7618 struct block_symbol vsym
;
7619 struct value
*value
;
7621 struct breakpoint
*bp
;
7623 vsym
= lookup_symbol_search_name (sym
->search_name (),
7625 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7626 /* If the value was optimized out, revert to the old behavior. */
7627 if (! value_optimized_out (value
))
7629 handler
= value_as_address (value
);
7631 infrun_log_debug ("exception resume at %lx",
7632 (unsigned long) handler
);
7634 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7636 bp_exception_resume
).release ();
7638 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7641 bp
->thread
= tp
->global_num
;
7642 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7645 catch (const gdb_exception_error
&e
)
7647 /* We want to ignore errors here. */
7651 /* A helper for check_exception_resume that sets an
7652 exception-breakpoint based on a SystemTap probe. */
7655 insert_exception_resume_from_probe (struct thread_info
*tp
,
7656 const struct bound_probe
*probe
,
7657 struct frame_info
*frame
)
7659 struct value
*arg_value
;
7661 struct breakpoint
*bp
;
7663 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7667 handler
= value_as_address (arg_value
);
7669 infrun_log_debug ("exception resume at %s",
7670 paddress (probe
->objfile
->arch (), handler
));
7672 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7673 handler
, bp_exception_resume
).release ();
7674 bp
->thread
= tp
->global_num
;
7675 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7678 /* This is called when an exception has been intercepted. Check to
7679 see whether the exception's destination is of interest, and if so,
7680 set an exception resume breakpoint there. */
7683 check_exception_resume (struct execution_control_state
*ecs
,
7684 struct frame_info
*frame
)
7686 struct bound_probe probe
;
7687 struct symbol
*func
;
7689 /* First see if this exception unwinding breakpoint was set via a
7690 SystemTap probe point. If so, the probe has two arguments: the
7691 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7692 set a breakpoint there. */
7693 probe
= find_probe_by_pc (get_frame_pc (frame
));
7696 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7700 func
= get_frame_function (frame
);
7706 const struct block
*b
;
7707 struct block_iterator iter
;
7711 /* The exception breakpoint is a thread-specific breakpoint on
7712 the unwinder's debug hook, declared as:
7714 void _Unwind_DebugHook (void *cfa, void *handler);
7716 The CFA argument indicates the frame to which control is
7717 about to be transferred. HANDLER is the destination PC.
7719 We ignore the CFA and set a temporary breakpoint at HANDLER.
7720 This is not extremely efficient but it avoids issues in gdb
7721 with computing the DWARF CFA, and it also works even in weird
7722 cases such as throwing an exception from inside a signal
7725 b
= SYMBOL_BLOCK_VALUE (func
);
7726 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7728 if (!SYMBOL_IS_ARGUMENT (sym
))
7735 insert_exception_resume_breakpoint (ecs
->event_thread
,
7741 catch (const gdb_exception_error
&e
)
7747 stop_waiting (struct execution_control_state
*ecs
)
7749 infrun_log_debug ("stop_waiting");
7751 /* Let callers know we don't want to wait for the inferior anymore. */
7752 ecs
->wait_some_more
= 0;
7754 /* If all-stop, but there exists a non-stop target, stop all
7755 threads now that we're presenting the stop to the user. */
7756 if (!non_stop
&& exists_non_stop_target ())
7757 stop_all_threads ();
7760 /* Like keep_going, but passes the signal to the inferior, even if the
7761 signal is set to nopass. */
7764 keep_going_pass_signal (struct execution_control_state
*ecs
)
7766 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7767 gdb_assert (!ecs
->event_thread
->resumed
);
7769 /* Save the pc before execution, to compare with pc after stop. */
7770 ecs
->event_thread
->prev_pc
7771 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7773 if (ecs
->event_thread
->control
.trap_expected
)
7775 struct thread_info
*tp
= ecs
->event_thread
;
7777 infrun_log_debug ("%s has trap_expected set, "
7778 "resuming to collect trap",
7779 target_pid_to_str (tp
->ptid
).c_str ());
7781 /* We haven't yet gotten our trap, and either: intercepted a
7782 non-signal event (e.g., a fork); or took a signal which we
7783 are supposed to pass through to the inferior. Simply
7785 resume (ecs
->event_thread
->suspend
.stop_signal
);
7787 else if (step_over_info_valid_p ())
7789 /* Another thread is stepping over a breakpoint in-line. If
7790 this thread needs a step-over too, queue the request. In
7791 either case, this resume must be deferred for later. */
7792 struct thread_info
*tp
= ecs
->event_thread
;
7794 if (ecs
->hit_singlestep_breakpoint
7795 || thread_still_needs_step_over (tp
))
7797 infrun_log_debug ("step-over already in progress: "
7798 "step-over for %s deferred",
7799 target_pid_to_str (tp
->ptid
).c_str ());
7800 global_thread_step_over_chain_enqueue (tp
);
7804 infrun_log_debug ("step-over in progress: resume of %s deferred",
7805 target_pid_to_str (tp
->ptid
).c_str ());
7810 struct regcache
*regcache
= get_current_regcache ();
7813 step_over_what step_what
;
7815 /* Either the trap was not expected, but we are continuing
7816 anyway (if we got a signal, the user asked it be passed to
7819 We got our expected trap, but decided we should resume from
7822 We're going to run this baby now!
7824 Note that insert_breakpoints won't try to re-insert
7825 already inserted breakpoints. Therefore, we don't
7826 care if breakpoints were already inserted, or not. */
7828 /* If we need to step over a breakpoint, and we're not using
7829 displaced stepping to do so, insert all breakpoints
7830 (watchpoints, etc.) but the one we're stepping over, step one
7831 instruction, and then re-insert the breakpoint when that step
7834 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7836 remove_bp
= (ecs
->hit_singlestep_breakpoint
7837 || (step_what
& STEP_OVER_BREAKPOINT
));
7838 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7840 /* We can't use displaced stepping if we need to step past a
7841 watchpoint. The instruction copied to the scratch pad would
7842 still trigger the watchpoint. */
7844 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7846 set_step_over_info (regcache
->aspace (),
7847 regcache_read_pc (regcache
), remove_wps
,
7848 ecs
->event_thread
->global_num
);
7850 else if (remove_wps
)
7851 set_step_over_info (NULL
, 0, remove_wps
, -1);
7853 /* If we now need to do an in-line step-over, we need to stop
7854 all other threads. Note this must be done before
7855 insert_breakpoints below, because that removes the breakpoint
7856 we're about to step over, otherwise other threads could miss
7858 if (step_over_info_valid_p () && target_is_non_stop_p ())
7859 stop_all_threads ();
7861 /* Stop stepping if inserting breakpoints fails. */
7864 insert_breakpoints ();
7866 catch (const gdb_exception_error
&e
)
7868 exception_print (gdb_stderr
, e
);
7870 clear_step_over_info ();
7874 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7876 resume (ecs
->event_thread
->suspend
.stop_signal
);
7879 prepare_to_wait (ecs
);
7882 /* Called when we should continue running the inferior, because the
7883 current event doesn't cause a user visible stop. This does the
7884 resuming part; waiting for the next event is done elsewhere. */
7887 keep_going (struct execution_control_state
*ecs
)
7889 if (ecs
->event_thread
->control
.trap_expected
7890 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7891 ecs
->event_thread
->control
.trap_expected
= 0;
7893 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7894 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7895 keep_going_pass_signal (ecs
);
7898 /* This function normally comes after a resume, before
7899 handle_inferior_event exits. It takes care of any last bits of
7900 housekeeping, and sets the all-important wait_some_more flag. */
7903 prepare_to_wait (struct execution_control_state
*ecs
)
7905 infrun_log_debug ("prepare_to_wait");
7907 ecs
->wait_some_more
= 1;
7909 /* If the target can't async, emulate it by marking the infrun event
7910 handler such that as soon as we get back to the event-loop, we
7911 immediately end up in fetch_inferior_event again calling
7913 if (!target_can_async_p ())
7914 mark_infrun_async_event_handler ();
7917 /* We are done with the step range of a step/next/si/ni command.
7918 Called once for each n of a "step n" operation. */
7921 end_stepping_range (struct execution_control_state
*ecs
)
7923 ecs
->event_thread
->control
.stop_step
= 1;
7927 /* Several print_*_reason functions to print why the inferior has stopped.
7928 We always print something when the inferior exits, or receives a signal.
7929 The rest of the cases are dealt with later on in normal_stop and
7930 print_it_typical. Ideally there should be a call to one of these
7931 print_*_reason functions functions from handle_inferior_event each time
7932 stop_waiting is called.
7934 Note that we don't call these directly, instead we delegate that to
7935 the interpreters, through observers. Interpreters then call these
7936 with whatever uiout is right. */
7939 print_end_stepping_range_reason (struct ui_out
*uiout
)
7941 /* For CLI-like interpreters, print nothing. */
7943 if (uiout
->is_mi_like_p ())
7945 uiout
->field_string ("reason",
7946 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7951 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7953 annotate_signalled ();
7954 if (uiout
->is_mi_like_p ())
7956 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7957 uiout
->text ("\nProgram terminated with signal ");
7958 annotate_signal_name ();
7959 uiout
->field_string ("signal-name",
7960 gdb_signal_to_name (siggnal
));
7961 annotate_signal_name_end ();
7963 annotate_signal_string ();
7964 uiout
->field_string ("signal-meaning",
7965 gdb_signal_to_string (siggnal
));
7966 annotate_signal_string_end ();
7967 uiout
->text (".\n");
7968 uiout
->text ("The program no longer exists.\n");
7972 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7974 struct inferior
*inf
= current_inferior ();
7975 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7977 annotate_exited (exitstatus
);
7980 if (uiout
->is_mi_like_p ())
7981 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7982 std::string exit_code_str
7983 = string_printf ("0%o", (unsigned int) exitstatus
);
7984 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7985 plongest (inf
->num
), pidstr
.c_str (),
7986 string_field ("exit-code", exit_code_str
.c_str ()));
7990 if (uiout
->is_mi_like_p ())
7992 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7993 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7994 plongest (inf
->num
), pidstr
.c_str ());
7998 /* Some targets/architectures can do extra processing/display of
7999 segmentation faults. E.g., Intel MPX boundary faults.
8000 Call the architecture dependent function to handle the fault. */
8003 handle_segmentation_fault (struct ui_out
*uiout
)
8005 struct regcache
*regcache
= get_current_regcache ();
8006 struct gdbarch
*gdbarch
= regcache
->arch ();
8008 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8009 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8013 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8015 struct thread_info
*thr
= inferior_thread ();
8019 if (uiout
->is_mi_like_p ())
8021 else if (show_thread_that_caused_stop ())
8025 uiout
->text ("\nThread ");
8026 uiout
->field_string ("thread-id", print_thread_id (thr
));
8028 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8031 uiout
->text (" \"");
8032 uiout
->field_string ("name", name
);
8037 uiout
->text ("\nProgram");
8039 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8040 uiout
->text (" stopped");
8043 uiout
->text (" received signal ");
8044 annotate_signal_name ();
8045 if (uiout
->is_mi_like_p ())
8047 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8048 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8049 annotate_signal_name_end ();
8051 annotate_signal_string ();
8052 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8054 if (siggnal
== GDB_SIGNAL_SEGV
)
8055 handle_segmentation_fault (uiout
);
8057 annotate_signal_string_end ();
8059 uiout
->text (".\n");
8063 print_no_history_reason (struct ui_out
*uiout
)
8065 uiout
->text ("\nNo more reverse-execution history.\n");
8068 /* Print current location without a level number, if we have changed
8069 functions or hit a breakpoint. Print source line if we have one.
8070 bpstat_print contains the logic deciding in detail what to print,
8071 based on the event(s) that just occurred. */
8074 print_stop_location (struct target_waitstatus
*ws
)
8077 enum print_what source_flag
;
8078 int do_frame_printing
= 1;
8079 struct thread_info
*tp
= inferior_thread ();
8081 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8085 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8086 should) carry around the function and does (or should) use
8087 that when doing a frame comparison. */
8088 if (tp
->control
.stop_step
8089 && frame_id_eq (tp
->control
.step_frame_id
,
8090 get_frame_id (get_current_frame ()))
8091 && (tp
->control
.step_start_function
8092 == find_pc_function (tp
->suspend
.stop_pc
)))
8094 /* Finished step, just print source line. */
8095 source_flag
= SRC_LINE
;
8099 /* Print location and source line. */
8100 source_flag
= SRC_AND_LOC
;
8103 case PRINT_SRC_AND_LOC
:
8104 /* Print location and source line. */
8105 source_flag
= SRC_AND_LOC
;
8107 case PRINT_SRC_ONLY
:
8108 source_flag
= SRC_LINE
;
8111 /* Something bogus. */
8112 source_flag
= SRC_LINE
;
8113 do_frame_printing
= 0;
8116 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8119 /* The behavior of this routine with respect to the source
8121 SRC_LINE: Print only source line
8122 LOCATION: Print only location
8123 SRC_AND_LOC: Print location and source line. */
8124 if (do_frame_printing
)
8125 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8131 print_stop_event (struct ui_out
*uiout
, bool displays
)
8133 struct target_waitstatus last
;
8134 struct thread_info
*tp
;
8136 get_last_target_status (nullptr, nullptr, &last
);
8139 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8141 print_stop_location (&last
);
8143 /* Display the auto-display expressions. */
8148 tp
= inferior_thread ();
8149 if (tp
->thread_fsm
!= NULL
8150 && tp
->thread_fsm
->finished_p ())
8152 struct return_value_info
*rv
;
8154 rv
= tp
->thread_fsm
->return_value ();
8156 print_return_value (uiout
, rv
);
8163 maybe_remove_breakpoints (void)
8165 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8167 if (remove_breakpoints ())
8169 target_terminal::ours_for_output ();
8170 printf_filtered (_("Cannot remove breakpoints because "
8171 "program is no longer writable.\nFurther "
8172 "execution is probably impossible.\n"));
8177 /* The execution context that just caused a normal stop. */
8184 DISABLE_COPY_AND_ASSIGN (stop_context
);
8186 bool changed () const;
8191 /* The event PTID. */
8195 /* If stopp for a thread event, this is the thread that caused the
8197 struct thread_info
*thread
;
8199 /* The inferior that caused the stop. */
8203 /* Initializes a new stop context. If stopped for a thread event, this
8204 takes a strong reference to the thread. */
8206 stop_context::stop_context ()
8208 stop_id
= get_stop_id ();
8209 ptid
= inferior_ptid
;
8210 inf_num
= current_inferior ()->num
;
8212 if (inferior_ptid
!= null_ptid
)
8214 /* Take a strong reference so that the thread can't be deleted
8216 thread
= inferior_thread ();
8223 /* Release a stop context previously created with save_stop_context.
8224 Releases the strong reference to the thread as well. */
8226 stop_context::~stop_context ()
8232 /* Return true if the current context no longer matches the saved stop
8236 stop_context::changed () const
8238 if (ptid
!= inferior_ptid
)
8240 if (inf_num
!= current_inferior ()->num
)
8242 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8244 if (get_stop_id () != stop_id
)
8254 struct target_waitstatus last
;
8256 get_last_target_status (nullptr, nullptr, &last
);
8260 /* If an exception is thrown from this point on, make sure to
8261 propagate GDB's knowledge of the executing state to the
8262 frontend/user running state. A QUIT is an easy exception to see
8263 here, so do this before any filtered output. */
8265 ptid_t finish_ptid
= null_ptid
;
8268 finish_ptid
= minus_one_ptid
;
8269 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8270 || last
.kind
== TARGET_WAITKIND_EXITED
)
8272 /* On some targets, we may still have live threads in the
8273 inferior when we get a process exit event. E.g., for
8274 "checkpoint", when the current checkpoint/fork exits,
8275 linux-fork.c automatically switches to another fork from
8276 within target_mourn_inferior. */
8277 if (inferior_ptid
!= null_ptid
)
8278 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8280 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8281 finish_ptid
= inferior_ptid
;
8283 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8284 if (finish_ptid
!= null_ptid
)
8286 maybe_finish_thread_state
.emplace
8287 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8290 /* As we're presenting a stop, and potentially removing breakpoints,
8291 update the thread list so we can tell whether there are threads
8292 running on the target. With target remote, for example, we can
8293 only learn about new threads when we explicitly update the thread
8294 list. Do this before notifying the interpreters about signal
8295 stops, end of stepping ranges, etc., so that the "new thread"
8296 output is emitted before e.g., "Program received signal FOO",
8297 instead of after. */
8298 update_thread_list ();
8300 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8301 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8303 /* As with the notification of thread events, we want to delay
8304 notifying the user that we've switched thread context until
8305 the inferior actually stops.
8307 There's no point in saying anything if the inferior has exited.
8308 Note that SIGNALLED here means "exited with a signal", not
8309 "received a signal".
8311 Also skip saying anything in non-stop mode. In that mode, as we
8312 don't want GDB to switch threads behind the user's back, to avoid
8313 races where the user is typing a command to apply to thread x,
8314 but GDB switches to thread y before the user finishes entering
8315 the command, fetch_inferior_event installs a cleanup to restore
8316 the current thread back to the thread the user had selected right
8317 after this event is handled, so we're not really switching, only
8318 informing of a stop. */
8320 && previous_inferior_ptid
!= inferior_ptid
8321 && target_has_execution
8322 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8323 && last
.kind
!= TARGET_WAITKIND_EXITED
8324 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8326 SWITCH_THRU_ALL_UIS ()
8328 target_terminal::ours_for_output ();
8329 printf_filtered (_("[Switching to %s]\n"),
8330 target_pid_to_str (inferior_ptid
).c_str ());
8331 annotate_thread_changed ();
8333 previous_inferior_ptid
= inferior_ptid
;
8336 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8338 SWITCH_THRU_ALL_UIS ()
8339 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8341 target_terminal::ours_for_output ();
8342 printf_filtered (_("No unwaited-for children left.\n"));
8346 /* Note: this depends on the update_thread_list call above. */
8347 maybe_remove_breakpoints ();
8349 /* If an auto-display called a function and that got a signal,
8350 delete that auto-display to avoid an infinite recursion. */
8352 if (stopped_by_random_signal
)
8353 disable_current_display ();
8355 SWITCH_THRU_ALL_UIS ()
8357 async_enable_stdin ();
8360 /* Let the user/frontend see the threads as stopped. */
8361 maybe_finish_thread_state
.reset ();
8363 /* Select innermost stack frame - i.e., current frame is frame 0,
8364 and current location is based on that. Handle the case where the
8365 dummy call is returning after being stopped. E.g. the dummy call
8366 previously hit a breakpoint. (If the dummy call returns
8367 normally, we won't reach here.) Do this before the stop hook is
8368 run, so that it doesn't get to see the temporary dummy frame,
8369 which is not where we'll present the stop. */
8370 if (has_stack_frames ())
8372 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8374 /* Pop the empty frame that contains the stack dummy. This
8375 also restores inferior state prior to the call (struct
8376 infcall_suspend_state). */
8377 struct frame_info
*frame
= get_current_frame ();
8379 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8381 /* frame_pop calls reinit_frame_cache as the last thing it
8382 does which means there's now no selected frame. */
8385 select_frame (get_current_frame ());
8387 /* Set the current source location. */
8388 set_current_sal_from_frame (get_current_frame ());
8391 /* Look up the hook_stop and run it (CLI internally handles problem
8392 of stop_command's pre-hook not existing). */
8393 if (stop_command
!= NULL
)
8395 stop_context saved_context
;
8399 execute_cmd_pre_hook (stop_command
);
8401 catch (const gdb_exception
&ex
)
8403 exception_fprintf (gdb_stderr
, ex
,
8404 "Error while running hook_stop:\n");
8407 /* If the stop hook resumes the target, then there's no point in
8408 trying to notify about the previous stop; its context is
8409 gone. Likewise if the command switches thread or inferior --
8410 the observers would print a stop for the wrong
8412 if (saved_context
.changed ())
8416 /* Notify observers about the stop. This is where the interpreters
8417 print the stop event. */
8418 if (inferior_ptid
!= null_ptid
)
8419 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8422 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8424 annotate_stopped ();
8426 if (target_has_execution
)
8428 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8429 && last
.kind
!= TARGET_WAITKIND_EXITED
8430 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8431 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8432 Delete any breakpoint that is to be deleted at the next stop. */
8433 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8436 /* Try to get rid of automatically added inferiors that are no
8437 longer needed. Keeping those around slows down things linearly.
8438 Note that this never removes the current inferior. */
8445 signal_stop_state (int signo
)
8447 return signal_stop
[signo
];
8451 signal_print_state (int signo
)
8453 return signal_print
[signo
];
8457 signal_pass_state (int signo
)
8459 return signal_program
[signo
];
8463 signal_cache_update (int signo
)
8467 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8468 signal_cache_update (signo
);
8473 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8474 && signal_print
[signo
] == 0
8475 && signal_program
[signo
] == 1
8476 && signal_catch
[signo
] == 0);
8480 signal_stop_update (int signo
, int state
)
8482 int ret
= signal_stop
[signo
];
8484 signal_stop
[signo
] = state
;
8485 signal_cache_update (signo
);
8490 signal_print_update (int signo
, int state
)
8492 int ret
= signal_print
[signo
];
8494 signal_print
[signo
] = state
;
8495 signal_cache_update (signo
);
8500 signal_pass_update (int signo
, int state
)
8502 int ret
= signal_program
[signo
];
8504 signal_program
[signo
] = state
;
8505 signal_cache_update (signo
);
8509 /* Update the global 'signal_catch' from INFO and notify the
8513 signal_catch_update (const unsigned int *info
)
8517 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8518 signal_catch
[i
] = info
[i
] > 0;
8519 signal_cache_update (-1);
8520 target_pass_signals (signal_pass
);
8524 sig_print_header (void)
8526 printf_filtered (_("Signal Stop\tPrint\tPass "
8527 "to program\tDescription\n"));
8531 sig_print_info (enum gdb_signal oursig
)
8533 const char *name
= gdb_signal_to_name (oursig
);
8534 int name_padding
= 13 - strlen (name
);
8536 if (name_padding
<= 0)
8539 printf_filtered ("%s", name
);
8540 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8541 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8542 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8543 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8544 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8547 /* Specify how various signals in the inferior should be handled. */
8550 handle_command (const char *args
, int from_tty
)
8552 int digits
, wordlen
;
8553 int sigfirst
, siglast
;
8554 enum gdb_signal oursig
;
8559 error_no_arg (_("signal to handle"));
8562 /* Allocate and zero an array of flags for which signals to handle. */
8564 const size_t nsigs
= GDB_SIGNAL_LAST
;
8565 unsigned char sigs
[nsigs
] {};
8567 /* Break the command line up into args. */
8569 gdb_argv
built_argv (args
);
8571 /* Walk through the args, looking for signal oursigs, signal names, and
8572 actions. Signal numbers and signal names may be interspersed with
8573 actions, with the actions being performed for all signals cumulatively
8574 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8576 for (char *arg
: built_argv
)
8578 wordlen
= strlen (arg
);
8579 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8583 sigfirst
= siglast
= -1;
8585 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8587 /* Apply action to all signals except those used by the
8588 debugger. Silently skip those. */
8591 siglast
= nsigs
- 1;
8593 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8595 SET_SIGS (nsigs
, sigs
, signal_stop
);
8596 SET_SIGS (nsigs
, sigs
, signal_print
);
8598 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8600 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8602 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8604 SET_SIGS (nsigs
, sigs
, signal_print
);
8606 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8608 SET_SIGS (nsigs
, sigs
, signal_program
);
8610 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8612 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8614 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8616 SET_SIGS (nsigs
, sigs
, signal_program
);
8618 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8620 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8621 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8623 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8625 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8627 else if (digits
> 0)
8629 /* It is numeric. The numeric signal refers to our own
8630 internal signal numbering from target.h, not to host/target
8631 signal number. This is a feature; users really should be
8632 using symbolic names anyway, and the common ones like
8633 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8635 sigfirst
= siglast
= (int)
8636 gdb_signal_from_command (atoi (arg
));
8637 if (arg
[digits
] == '-')
8640 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8642 if (sigfirst
> siglast
)
8644 /* Bet he didn't figure we'd think of this case... */
8645 std::swap (sigfirst
, siglast
);
8650 oursig
= gdb_signal_from_name (arg
);
8651 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8653 sigfirst
= siglast
= (int) oursig
;
8657 /* Not a number and not a recognized flag word => complain. */
8658 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8662 /* If any signal numbers or symbol names were found, set flags for
8663 which signals to apply actions to. */
8665 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8667 switch ((enum gdb_signal
) signum
)
8669 case GDB_SIGNAL_TRAP
:
8670 case GDB_SIGNAL_INT
:
8671 if (!allsigs
&& !sigs
[signum
])
8673 if (query (_("%s is used by the debugger.\n\
8674 Are you sure you want to change it? "),
8675 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8680 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8684 case GDB_SIGNAL_DEFAULT
:
8685 case GDB_SIGNAL_UNKNOWN
:
8686 /* Make sure that "all" doesn't print these. */
8695 for (int signum
= 0; signum
< nsigs
; signum
++)
8698 signal_cache_update (-1);
8699 target_pass_signals (signal_pass
);
8700 target_program_signals (signal_program
);
8704 /* Show the results. */
8705 sig_print_header ();
8706 for (; signum
< nsigs
; signum
++)
8708 sig_print_info ((enum gdb_signal
) signum
);
8715 /* Complete the "handle" command. */
8718 handle_completer (struct cmd_list_element
*ignore
,
8719 completion_tracker
&tracker
,
8720 const char *text
, const char *word
)
8722 static const char * const keywords
[] =
8736 signal_completer (ignore
, tracker
, text
, word
);
8737 complete_on_enum (tracker
, keywords
, word
, word
);
8741 gdb_signal_from_command (int num
)
8743 if (num
>= 1 && num
<= 15)
8744 return (enum gdb_signal
) num
;
8745 error (_("Only signals 1-15 are valid as numeric signals.\n\
8746 Use \"info signals\" for a list of symbolic signals."));
8749 /* Print current contents of the tables set by the handle command.
8750 It is possible we should just be printing signals actually used
8751 by the current target (but for things to work right when switching
8752 targets, all signals should be in the signal tables). */
8755 info_signals_command (const char *signum_exp
, int from_tty
)
8757 enum gdb_signal oursig
;
8759 sig_print_header ();
8763 /* First see if this is a symbol name. */
8764 oursig
= gdb_signal_from_name (signum_exp
);
8765 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8767 /* No, try numeric. */
8769 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8771 sig_print_info (oursig
);
8775 printf_filtered ("\n");
8776 /* These ugly casts brought to you by the native VAX compiler. */
8777 for (oursig
= GDB_SIGNAL_FIRST
;
8778 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8779 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8783 if (oursig
!= GDB_SIGNAL_UNKNOWN
8784 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8785 sig_print_info (oursig
);
8788 printf_filtered (_("\nUse the \"handle\" command "
8789 "to change these tables.\n"));
8792 /* The $_siginfo convenience variable is a bit special. We don't know
8793 for sure the type of the value until we actually have a chance to
8794 fetch the data. The type can change depending on gdbarch, so it is
8795 also dependent on which thread you have selected.
8797 1. making $_siginfo be an internalvar that creates a new value on
8800 2. making the value of $_siginfo be an lval_computed value. */
8802 /* This function implements the lval_computed support for reading a
8806 siginfo_value_read (struct value
*v
)
8808 LONGEST transferred
;
8810 /* If we can access registers, so can we access $_siginfo. Likewise
8812 validate_registers_access ();
8815 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8817 value_contents_all_raw (v
),
8819 TYPE_LENGTH (value_type (v
)));
8821 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8822 error (_("Unable to read siginfo"));
8825 /* This function implements the lval_computed support for writing a
8829 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8831 LONGEST transferred
;
8833 /* If we can access registers, so can we access $_siginfo. Likewise
8835 validate_registers_access ();
8837 transferred
= target_write (current_top_target (),
8838 TARGET_OBJECT_SIGNAL_INFO
,
8840 value_contents_all_raw (fromval
),
8842 TYPE_LENGTH (value_type (fromval
)));
8844 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8845 error (_("Unable to write siginfo"));
8848 static const struct lval_funcs siginfo_value_funcs
=
8854 /* Return a new value with the correct type for the siginfo object of
8855 the current thread using architecture GDBARCH. Return a void value
8856 if there's no object available. */
8858 static struct value
*
8859 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8862 if (target_has_stack
8863 && inferior_ptid
!= null_ptid
8864 && gdbarch_get_siginfo_type_p (gdbarch
))
8866 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8868 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8871 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8875 /* infcall_suspend_state contains state about the program itself like its
8876 registers and any signal it received when it last stopped.
8877 This state must be restored regardless of how the inferior function call
8878 ends (either successfully, or after it hits a breakpoint or signal)
8879 if the program is to properly continue where it left off. */
8881 class infcall_suspend_state
8884 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8885 once the inferior function call has finished. */
8886 infcall_suspend_state (struct gdbarch
*gdbarch
,
8887 const struct thread_info
*tp
,
8888 struct regcache
*regcache
)
8889 : m_thread_suspend (tp
->suspend
),
8890 m_registers (new readonly_detached_regcache (*regcache
))
8892 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8894 if (gdbarch_get_siginfo_type_p (gdbarch
))
8896 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8897 size_t len
= TYPE_LENGTH (type
);
8899 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8901 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8902 siginfo_data
.get (), 0, len
) != len
)
8904 /* Errors ignored. */
8905 siginfo_data
.reset (nullptr);
8911 m_siginfo_gdbarch
= gdbarch
;
8912 m_siginfo_data
= std::move (siginfo_data
);
8916 /* Return a pointer to the stored register state. */
8918 readonly_detached_regcache
*registers () const
8920 return m_registers
.get ();
8923 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8925 void restore (struct gdbarch
*gdbarch
,
8926 struct thread_info
*tp
,
8927 struct regcache
*regcache
) const
8929 tp
->suspend
= m_thread_suspend
;
8931 if (m_siginfo_gdbarch
== gdbarch
)
8933 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8935 /* Errors ignored. */
8936 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8937 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8940 /* The inferior can be gone if the user types "print exit(0)"
8941 (and perhaps other times). */
8942 if (target_has_execution
)
8943 /* NB: The register write goes through to the target. */
8944 regcache
->restore (registers ());
8948 /* How the current thread stopped before the inferior function call was
8950 struct thread_suspend_state m_thread_suspend
;
8952 /* The registers before the inferior function call was executed. */
8953 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8955 /* Format of SIGINFO_DATA or NULL if it is not present. */
8956 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8958 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8959 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8960 content would be invalid. */
8961 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8964 infcall_suspend_state_up
8965 save_infcall_suspend_state ()
8967 struct thread_info
*tp
= inferior_thread ();
8968 struct regcache
*regcache
= get_current_regcache ();
8969 struct gdbarch
*gdbarch
= regcache
->arch ();
8971 infcall_suspend_state_up inf_state
8972 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8974 /* Having saved the current state, adjust the thread state, discarding
8975 any stop signal information. The stop signal is not useful when
8976 starting an inferior function call, and run_inferior_call will not use
8977 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8978 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8983 /* Restore inferior session state to INF_STATE. */
8986 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8988 struct thread_info
*tp
= inferior_thread ();
8989 struct regcache
*regcache
= get_current_regcache ();
8990 struct gdbarch
*gdbarch
= regcache
->arch ();
8992 inf_state
->restore (gdbarch
, tp
, regcache
);
8993 discard_infcall_suspend_state (inf_state
);
8997 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9002 readonly_detached_regcache
*
9003 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9005 return inf_state
->registers ();
9008 /* infcall_control_state contains state regarding gdb's control of the
9009 inferior itself like stepping control. It also contains session state like
9010 the user's currently selected frame. */
9012 struct infcall_control_state
9014 struct thread_control_state thread_control
;
9015 struct inferior_control_state inferior_control
;
9018 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9019 int stopped_by_random_signal
= 0;
9021 /* ID if the selected frame when the inferior function call was made. */
9022 struct frame_id selected_frame_id
{};
9025 /* Save all of the information associated with the inferior<==>gdb
9028 infcall_control_state_up
9029 save_infcall_control_state ()
9031 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9032 struct thread_info
*tp
= inferior_thread ();
9033 struct inferior
*inf
= current_inferior ();
9035 inf_status
->thread_control
= tp
->control
;
9036 inf_status
->inferior_control
= inf
->control
;
9038 tp
->control
.step_resume_breakpoint
= NULL
;
9039 tp
->control
.exception_resume_breakpoint
= NULL
;
9041 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9042 chain. If caller's caller is walking the chain, they'll be happier if we
9043 hand them back the original chain when restore_infcall_control_state is
9045 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9048 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9049 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9051 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9057 restore_selected_frame (const frame_id
&fid
)
9059 frame_info
*frame
= frame_find_by_id (fid
);
9061 /* If inf_status->selected_frame_id is NULL, there was no previously
9065 warning (_("Unable to restore previously selected frame."));
9069 select_frame (frame
);
9072 /* Restore inferior session state to INF_STATUS. */
9075 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9077 struct thread_info
*tp
= inferior_thread ();
9078 struct inferior
*inf
= current_inferior ();
9080 if (tp
->control
.step_resume_breakpoint
)
9081 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9083 if (tp
->control
.exception_resume_breakpoint
)
9084 tp
->control
.exception_resume_breakpoint
->disposition
9085 = disp_del_at_next_stop
;
9087 /* Handle the bpstat_copy of the chain. */
9088 bpstat_clear (&tp
->control
.stop_bpstat
);
9090 tp
->control
= inf_status
->thread_control
;
9091 inf
->control
= inf_status
->inferior_control
;
9094 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9095 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9097 if (target_has_stack
)
9099 /* The point of the try/catch is that if the stack is clobbered,
9100 walking the stack might encounter a garbage pointer and
9101 error() trying to dereference it. */
9104 restore_selected_frame (inf_status
->selected_frame_id
);
9106 catch (const gdb_exception_error
&ex
)
9108 exception_fprintf (gdb_stderr
, ex
,
9109 "Unable to restore previously selected frame:\n");
9110 /* Error in restoring the selected frame. Select the
9112 select_frame (get_current_frame ());
9120 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9122 if (inf_status
->thread_control
.step_resume_breakpoint
)
9123 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9124 = disp_del_at_next_stop
;
9126 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9127 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9128 = disp_del_at_next_stop
;
9130 /* See save_infcall_control_state for info on stop_bpstat. */
9131 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9139 clear_exit_convenience_vars (void)
9141 clear_internalvar (lookup_internalvar ("_exitsignal"));
9142 clear_internalvar (lookup_internalvar ("_exitcode"));
9146 /* User interface for reverse debugging:
9147 Set exec-direction / show exec-direction commands
9148 (returns error unless target implements to_set_exec_direction method). */
9150 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9151 static const char exec_forward
[] = "forward";
9152 static const char exec_reverse
[] = "reverse";
9153 static const char *exec_direction
= exec_forward
;
9154 static const char *const exec_direction_names
[] = {
9161 set_exec_direction_func (const char *args
, int from_tty
,
9162 struct cmd_list_element
*cmd
)
9164 if (target_can_execute_reverse
)
9166 if (!strcmp (exec_direction
, exec_forward
))
9167 execution_direction
= EXEC_FORWARD
;
9168 else if (!strcmp (exec_direction
, exec_reverse
))
9169 execution_direction
= EXEC_REVERSE
;
9173 exec_direction
= exec_forward
;
9174 error (_("Target does not support this operation."));
9179 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9180 struct cmd_list_element
*cmd
, const char *value
)
9182 switch (execution_direction
) {
9184 fprintf_filtered (out
, _("Forward.\n"));
9187 fprintf_filtered (out
, _("Reverse.\n"));
9190 internal_error (__FILE__
, __LINE__
,
9191 _("bogus execution_direction value: %d"),
9192 (int) execution_direction
);
9197 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9198 struct cmd_list_element
*c
, const char *value
)
9200 fprintf_filtered (file
, _("Resuming the execution of threads "
9201 "of all processes is %s.\n"), value
);
9204 /* Implementation of `siginfo' variable. */
9206 static const struct internalvar_funcs siginfo_funcs
=
9213 /* Callback for infrun's target events source. This is marked when a
9214 thread has a pending status to process. */
9217 infrun_async_inferior_event_handler (gdb_client_data data
)
9219 inferior_event_handler (INF_REG_EVENT
);
9222 void _initialize_infrun ();
9224 _initialize_infrun ()
9226 struct cmd_list_element
*c
;
9228 /* Register extra event sources in the event loop. */
9229 infrun_async_inferior_event_token
9230 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9232 add_info ("signals", info_signals_command
, _("\
9233 What debugger does when program gets various signals.\n\
9234 Specify a signal as argument to print info on that signal only."));
9235 add_info_alias ("handle", "signals", 0);
9237 c
= add_com ("handle", class_run
, handle_command
, _("\
9238 Specify how to handle signals.\n\
9239 Usage: handle SIGNAL [ACTIONS]\n\
9240 Args are signals and actions to apply to those signals.\n\
9241 If no actions are specified, the current settings for the specified signals\n\
9242 will be displayed instead.\n\
9244 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9245 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9246 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9247 The special arg \"all\" is recognized to mean all signals except those\n\
9248 used by the debugger, typically SIGTRAP and SIGINT.\n\
9250 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9251 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9252 Stop means reenter debugger if this signal happens (implies print).\n\
9253 Print means print a message if this signal happens.\n\
9254 Pass means let program see this signal; otherwise program doesn't know.\n\
9255 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9256 Pass and Stop may be combined.\n\
9258 Multiple signals may be specified. Signal numbers and signal names\n\
9259 may be interspersed with actions, with the actions being performed for\n\
9260 all signals cumulatively specified."));
9261 set_cmd_completer (c
, handle_completer
);
9264 stop_command
= add_cmd ("stop", class_obscure
,
9265 not_just_help_class_command
, _("\
9266 There is no `stop' command, but you can set a hook on `stop'.\n\
9267 This allows you to set a list of commands to be run each time execution\n\
9268 of the program stops."), &cmdlist
);
9270 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9271 Set inferior debugging."), _("\
9272 Show inferior debugging."), _("\
9273 When non-zero, inferior specific debugging is enabled."),
9276 &setdebuglist
, &showdebuglist
);
9278 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9279 &debug_displaced
, _("\
9280 Set displaced stepping debugging."), _("\
9281 Show displaced stepping debugging."), _("\
9282 When non-zero, displaced stepping specific debugging is enabled."),
9284 show_debug_displaced
,
9285 &setdebuglist
, &showdebuglist
);
9287 add_setshow_boolean_cmd ("non-stop", no_class
,
9289 Set whether gdb controls the inferior in non-stop mode."), _("\
9290 Show whether gdb controls the inferior in non-stop mode."), _("\
9291 When debugging a multi-threaded program and this setting is\n\
9292 off (the default, also called all-stop mode), when one thread stops\n\
9293 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9294 all other threads in the program while you interact with the thread of\n\
9295 interest. When you continue or step a thread, you can allow the other\n\
9296 threads to run, or have them remain stopped, but while you inspect any\n\
9297 thread's state, all threads stop.\n\
9299 In non-stop mode, when one thread stops, other threads can continue\n\
9300 to run freely. You'll be able to step each thread independently,\n\
9301 leave it stopped or free to run as needed."),
9307 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9310 signal_print
[i
] = 1;
9311 signal_program
[i
] = 1;
9312 signal_catch
[i
] = 0;
9315 /* Signals caused by debugger's own actions should not be given to
9316 the program afterwards.
9318 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9319 explicitly specifies that it should be delivered to the target
9320 program. Typically, that would occur when a user is debugging a
9321 target monitor on a simulator: the target monitor sets a
9322 breakpoint; the simulator encounters this breakpoint and halts
9323 the simulation handing control to GDB; GDB, noting that the stop
9324 address doesn't map to any known breakpoint, returns control back
9325 to the simulator; the simulator then delivers the hardware
9326 equivalent of a GDB_SIGNAL_TRAP to the program being
9328 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9329 signal_program
[GDB_SIGNAL_INT
] = 0;
9331 /* Signals that are not errors should not normally enter the debugger. */
9332 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9333 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9334 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9335 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9336 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9337 signal_print
[GDB_SIGNAL_PROF
] = 0;
9338 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9339 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9340 signal_stop
[GDB_SIGNAL_IO
] = 0;
9341 signal_print
[GDB_SIGNAL_IO
] = 0;
9342 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9343 signal_print
[GDB_SIGNAL_POLL
] = 0;
9344 signal_stop
[GDB_SIGNAL_URG
] = 0;
9345 signal_print
[GDB_SIGNAL_URG
] = 0;
9346 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9347 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9348 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9349 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9351 /* These signals are used internally by user-level thread
9352 implementations. (See signal(5) on Solaris.) Like the above
9353 signals, a healthy program receives and handles them as part of
9354 its normal operation. */
9355 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9356 signal_print
[GDB_SIGNAL_LWP
] = 0;
9357 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9358 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9359 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9360 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9361 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9362 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9364 /* Update cached state. */
9365 signal_cache_update (-1);
9367 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9368 &stop_on_solib_events
, _("\
9369 Set stopping for shared library events."), _("\
9370 Show stopping for shared library events."), _("\
9371 If nonzero, gdb will give control to the user when the dynamic linker\n\
9372 notifies gdb of shared library events. The most common event of interest\n\
9373 to the user would be loading/unloading of a new library."),
9374 set_stop_on_solib_events
,
9375 show_stop_on_solib_events
,
9376 &setlist
, &showlist
);
9378 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9379 follow_fork_mode_kind_names
,
9380 &follow_fork_mode_string
, _("\
9381 Set debugger response to a program call of fork or vfork."), _("\
9382 Show debugger response to a program call of fork or vfork."), _("\
9383 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9384 parent - the original process is debugged after a fork\n\
9385 child - the new process is debugged after a fork\n\
9386 The unfollowed process will continue to run.\n\
9387 By default, the debugger will follow the parent process."),
9389 show_follow_fork_mode_string
,
9390 &setlist
, &showlist
);
9392 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9393 follow_exec_mode_names
,
9394 &follow_exec_mode_string
, _("\
9395 Set debugger response to a program call of exec."), _("\
9396 Show debugger response to a program call of exec."), _("\
9397 An exec call replaces the program image of a process.\n\
9399 follow-exec-mode can be:\n\
9401 new - the debugger creates a new inferior and rebinds the process\n\
9402 to this new inferior. The program the process was running before\n\
9403 the exec call can be restarted afterwards by restarting the original\n\
9406 same - the debugger keeps the process bound to the same inferior.\n\
9407 The new executable image replaces the previous executable loaded in\n\
9408 the inferior. Restarting the inferior after the exec call restarts\n\
9409 the executable the process was running after the exec call.\n\
9411 By default, the debugger will use the same inferior."),
9413 show_follow_exec_mode_string
,
9414 &setlist
, &showlist
);
9416 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9417 scheduler_enums
, &scheduler_mode
, _("\
9418 Set mode for locking scheduler during execution."), _("\
9419 Show mode for locking scheduler during execution."), _("\
9420 off == no locking (threads may preempt at any time)\n\
9421 on == full locking (no thread except the current thread may run)\n\
9422 This applies to both normal execution and replay mode.\n\
9423 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9424 In this mode, other threads may run during other commands.\n\
9425 This applies to both normal execution and replay mode.\n\
9426 replay == scheduler locked in replay mode and unlocked during normal execution."),
9427 set_schedlock_func
, /* traps on target vector */
9428 show_scheduler_mode
,
9429 &setlist
, &showlist
);
9431 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9432 Set mode for resuming threads of all processes."), _("\
9433 Show mode for resuming threads of all processes."), _("\
9434 When on, execution commands (such as 'continue' or 'next') resume all\n\
9435 threads of all processes. When off (which is the default), execution\n\
9436 commands only resume the threads of the current process. The set of\n\
9437 threads that are resumed is further refined by the scheduler-locking\n\
9438 mode (see help set scheduler-locking)."),
9440 show_schedule_multiple
,
9441 &setlist
, &showlist
);
9443 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9444 Set mode of the step operation."), _("\
9445 Show mode of the step operation."), _("\
9446 When set, doing a step over a function without debug line information\n\
9447 will stop at the first instruction of that function. Otherwise, the\n\
9448 function is skipped and the step command stops at a different source line."),
9450 show_step_stop_if_no_debug
,
9451 &setlist
, &showlist
);
9453 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9454 &can_use_displaced_stepping
, _("\
9455 Set debugger's willingness to use displaced stepping."), _("\
9456 Show debugger's willingness to use displaced stepping."), _("\
9457 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9458 supported by the target architecture. If off, gdb will not use displaced\n\
9459 stepping to step over breakpoints, even if such is supported by the target\n\
9460 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9461 if the target architecture supports it and non-stop mode is active, but will not\n\
9462 use it in all-stop mode (see help set non-stop)."),
9464 show_can_use_displaced_stepping
,
9465 &setlist
, &showlist
);
9467 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9468 &exec_direction
, _("Set direction of execution.\n\
9469 Options are 'forward' or 'reverse'."),
9470 _("Show direction of execution (forward/reverse)."),
9471 _("Tells gdb whether to execute forward or backward."),
9472 set_exec_direction_func
, show_exec_direction_func
,
9473 &setlist
, &showlist
);
9475 /* Set/show detach-on-fork: user-settable mode. */
9477 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9478 Set whether gdb will detach the child of a fork."), _("\
9479 Show whether gdb will detach the child of a fork."), _("\
9480 Tells gdb whether to detach the child of a fork."),
9481 NULL
, NULL
, &setlist
, &showlist
);
9483 /* Set/show disable address space randomization mode. */
9485 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9486 &disable_randomization
, _("\
9487 Set disabling of debuggee's virtual address space randomization."), _("\
9488 Show disabling of debuggee's virtual address space randomization."), _("\
9489 When this mode is on (which is the default), randomization of the virtual\n\
9490 address space is disabled. Standalone programs run with the randomization\n\
9491 enabled by default on some platforms."),
9492 &set_disable_randomization
,
9493 &show_disable_randomization
,
9494 &setlist
, &showlist
);
9496 /* ptid initializations */
9497 inferior_ptid
= null_ptid
;
9498 target_last_wait_ptid
= minus_one_ptid
;
9500 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9501 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9502 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9503 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9505 /* Explicitly create without lookup, since that tries to create a
9506 value with a void typed value, and when we get here, gdbarch
9507 isn't initialized yet. At this point, we're quite sure there
9508 isn't another convenience variable of the same name. */
9509 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9511 add_setshow_boolean_cmd ("observer", no_class
,
9512 &observer_mode_1
, _("\
9513 Set whether gdb controls the inferior in observer mode."), _("\
9514 Show whether gdb controls the inferior in observer mode."), _("\
9515 In observer mode, GDB can get data from the inferior, but not\n\
9516 affect its execution. Registers and memory may not be changed,\n\
9517 breakpoints may not be set, and the program cannot be interrupted\n\