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 "gdbsupport/common-defs.h"
23 #include "gdbsupport/common-utils.h"
29 #include "breakpoint.h"
33 #include "target-connection.h"
34 #include "gdbthread.h"
41 #include "observable.h"
46 #include "mi/mi-common.h"
47 #include "event-top.h"
49 #include "record-full.h"
50 #include "inline-frame.h"
52 #include "tracepoint.h"
56 #include "completer.h"
57 #include "target-descriptions.h"
58 #include "target-dcache.h"
61 #include "gdbsupport/event-loop.h"
62 #include "thread-fsm.h"
63 #include "gdbsupport/enum-flags.h"
64 #include "progspace-and-thread.h"
65 #include "gdbsupport/gdb_optional.h"
66 #include "arch-utils.h"
67 #include "gdbsupport/scope-exit.h"
68 #include "gdbsupport/forward-scope-exit.h"
69 #include "gdbsupport/gdb_select.h"
70 #include <unordered_map>
71 #include "async-event.h"
73 /* Prototypes for local functions */
75 static void sig_print_info (enum gdb_signal
);
77 static void sig_print_header (void);
79 static void follow_inferior_reset_breakpoints (void);
81 static int currently_stepping (struct thread_info
*tp
);
83 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
85 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
87 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
89 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
91 static void resume (gdb_signal sig
);
93 static void wait_for_inferior (inferior
*inf
);
95 /* Asynchronous signal handler registered as event loop source for
96 when we have pending events ready to be passed to the core. */
97 static struct async_event_handler
*infrun_async_inferior_event_token
;
99 /* Stores whether infrun_async was previously enabled or disabled.
100 Starts off as -1, indicating "never enabled/disabled". */
101 static int infrun_is_async
= -1;
103 #define infrun_log_debug(fmt, args...) \
104 infrun_log_debug_1 (__LINE__, __func__, fmt, ##args)
106 static void ATTRIBUTE_PRINTF(3, 4)
107 infrun_log_debug_1 (int line
, const char *func
,
108 const char *fmt
, ...)
113 va_start (args
, fmt
);
114 std::string msg
= string_vprintf (fmt
, args
);
117 fprintf_unfiltered (gdb_stdout
, "infrun: %s: %s\n", func
, msg
.c_str ());
124 infrun_async (int enable
)
126 if (infrun_is_async
!= enable
)
128 infrun_is_async
= enable
;
130 infrun_log_debug ("enable=%d", enable
);
133 mark_async_event_handler (infrun_async_inferior_event_token
);
135 clear_async_event_handler (infrun_async_inferior_event_token
);
142 mark_infrun_async_event_handler (void)
144 mark_async_event_handler (infrun_async_inferior_event_token
);
147 /* When set, stop the 'step' command if we enter a function which has
148 no line number information. The normal behavior is that we step
149 over such function. */
150 bool step_stop_if_no_debug
= false;
152 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
153 struct cmd_list_element
*c
, const char *value
)
155 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
158 /* proceed and normal_stop use this to notify the user when the
159 inferior stopped in a different thread than it had been running
162 static ptid_t previous_inferior_ptid
;
164 /* If set (default for legacy reasons), when following a fork, GDB
165 will detach from one of the fork branches, child or parent.
166 Exactly which branch is detached depends on 'set follow-fork-mode'
169 static bool detach_fork
= true;
171 bool debug_displaced
= false;
173 show_debug_displaced (struct ui_file
*file
, int from_tty
,
174 struct cmd_list_element
*c
, const char *value
)
176 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
179 unsigned int debug_infrun
= 0;
181 show_debug_infrun (struct ui_file
*file
, int from_tty
,
182 struct cmd_list_element
*c
, const char *value
)
184 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
188 /* Support for disabling address space randomization. */
190 bool disable_randomization
= true;
193 show_disable_randomization (struct ui_file
*file
, int from_tty
,
194 struct cmd_list_element
*c
, const char *value
)
196 if (target_supports_disable_randomization ())
197 fprintf_filtered (file
,
198 _("Disabling randomization of debuggee's "
199 "virtual address space is %s.\n"),
202 fputs_filtered (_("Disabling randomization of debuggee's "
203 "virtual address space is unsupported on\n"
204 "this platform.\n"), file
);
208 set_disable_randomization (const char *args
, int from_tty
,
209 struct cmd_list_element
*c
)
211 if (!target_supports_disable_randomization ())
212 error (_("Disabling randomization of debuggee's "
213 "virtual address space is unsupported on\n"
217 /* User interface for non-stop mode. */
219 bool non_stop
= false;
220 static bool non_stop_1
= false;
223 set_non_stop (const char *args
, int from_tty
,
224 struct cmd_list_element
*c
)
226 if (target_has_execution
)
228 non_stop_1
= non_stop
;
229 error (_("Cannot change this setting while the inferior is running."));
232 non_stop
= non_stop_1
;
236 show_non_stop (struct ui_file
*file
, int from_tty
,
237 struct cmd_list_element
*c
, const char *value
)
239 fprintf_filtered (file
,
240 _("Controlling the inferior in non-stop mode is %s.\n"),
244 /* "Observer mode" is somewhat like a more extreme version of
245 non-stop, in which all GDB operations that might affect the
246 target's execution have been disabled. */
248 bool observer_mode
= false;
249 static bool observer_mode_1
= false;
252 set_observer_mode (const char *args
, int from_tty
,
253 struct cmd_list_element
*c
)
255 if (target_has_execution
)
257 observer_mode_1
= observer_mode
;
258 error (_("Cannot change this setting while the inferior is running."));
261 observer_mode
= observer_mode_1
;
263 may_write_registers
= !observer_mode
;
264 may_write_memory
= !observer_mode
;
265 may_insert_breakpoints
= !observer_mode
;
266 may_insert_tracepoints
= !observer_mode
;
267 /* We can insert fast tracepoints in or out of observer mode,
268 but enable them if we're going into this mode. */
270 may_insert_fast_tracepoints
= true;
271 may_stop
= !observer_mode
;
272 update_target_permissions ();
274 /* Going *into* observer mode we must force non-stop, then
275 going out we leave it that way. */
278 pagination_enabled
= 0;
279 non_stop
= non_stop_1
= true;
283 printf_filtered (_("Observer mode is now %s.\n"),
284 (observer_mode
? "on" : "off"));
288 show_observer_mode (struct ui_file
*file
, int from_tty
,
289 struct cmd_list_element
*c
, const char *value
)
291 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
294 /* This updates the value of observer mode based on changes in
295 permissions. Note that we are deliberately ignoring the values of
296 may-write-registers and may-write-memory, since the user may have
297 reason to enable these during a session, for instance to turn on a
298 debugging-related global. */
301 update_observer_mode (void)
303 bool newval
= (!may_insert_breakpoints
304 && !may_insert_tracepoints
305 && may_insert_fast_tracepoints
309 /* Let the user know if things change. */
310 if (newval
!= observer_mode
)
311 printf_filtered (_("Observer mode is now %s.\n"),
312 (newval
? "on" : "off"));
314 observer_mode
= observer_mode_1
= newval
;
317 /* Tables of how to react to signals; the user sets them. */
319 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
320 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
321 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
323 /* Table of signals that are registered with "catch signal". A
324 non-zero entry indicates that the signal is caught by some "catch
326 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
328 /* Table of signals that the target may silently handle.
329 This is automatically determined from the flags above,
330 and simply cached here. */
331 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
333 #define SET_SIGS(nsigs,sigs,flags) \
335 int signum = (nsigs); \
336 while (signum-- > 0) \
337 if ((sigs)[signum]) \
338 (flags)[signum] = 1; \
341 #define UNSET_SIGS(nsigs,sigs,flags) \
343 int signum = (nsigs); \
344 while (signum-- > 0) \
345 if ((sigs)[signum]) \
346 (flags)[signum] = 0; \
349 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
350 this function is to avoid exporting `signal_program'. */
353 update_signals_program_target (void)
355 target_program_signals (signal_program
);
358 /* Value to pass to target_resume() to cause all threads to resume. */
360 #define RESUME_ALL minus_one_ptid
362 /* Command list pointer for the "stop" placeholder. */
364 static struct cmd_list_element
*stop_command
;
366 /* Nonzero if we want to give control to the user when we're notified
367 of shared library events by the dynamic linker. */
368 int stop_on_solib_events
;
370 /* Enable or disable optional shared library event breakpoints
371 as appropriate when the above flag is changed. */
374 set_stop_on_solib_events (const char *args
,
375 int from_tty
, struct cmd_list_element
*c
)
377 update_solib_breakpoints ();
381 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
382 struct cmd_list_element
*c
, const char *value
)
384 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
388 /* Nonzero after stop if current stack frame should be printed. */
390 static int stop_print_frame
;
392 /* This is a cached copy of the target/ptid/waitstatus of the last
393 event returned by target_wait()/deprecated_target_wait_hook().
394 This information is returned by get_last_target_status(). */
395 static process_stratum_target
*target_last_proc_target
;
396 static ptid_t target_last_wait_ptid
;
397 static struct target_waitstatus target_last_waitstatus
;
399 void init_thread_stepping_state (struct thread_info
*tss
);
401 static const char follow_fork_mode_child
[] = "child";
402 static const char follow_fork_mode_parent
[] = "parent";
404 static const char *const follow_fork_mode_kind_names
[] = {
405 follow_fork_mode_child
,
406 follow_fork_mode_parent
,
410 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
412 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
413 struct cmd_list_element
*c
, const char *value
)
415 fprintf_filtered (file
,
416 _("Debugger response to a program "
417 "call of fork or vfork is \"%s\".\n"),
422 /* Handle changes to the inferior list based on the type of fork,
423 which process is being followed, and whether the other process
424 should be detached. On entry inferior_ptid must be the ptid of
425 the fork parent. At return inferior_ptid is the ptid of the
426 followed inferior. */
429 follow_fork_inferior (bool follow_child
, bool detach_fork
)
432 ptid_t parent_ptid
, child_ptid
;
434 has_vforked
= (inferior_thread ()->pending_follow
.kind
435 == TARGET_WAITKIND_VFORKED
);
436 parent_ptid
= inferior_ptid
;
437 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
440 && !non_stop
/* Non-stop always resumes both branches. */
441 && current_ui
->prompt_state
== PROMPT_BLOCKED
442 && !(follow_child
|| detach_fork
|| sched_multi
))
444 /* The parent stays blocked inside the vfork syscall until the
445 child execs or exits. If we don't let the child run, then
446 the parent stays blocked. If we're telling the parent to run
447 in the foreground, the user will not be able to ctrl-c to get
448 back the terminal, effectively hanging the debug session. */
449 fprintf_filtered (gdb_stderr
, _("\
450 Can not resume the parent process over vfork in the foreground while\n\
451 holding the child stopped. Try \"set detach-on-fork\" or \
452 \"set schedule-multiple\".\n"));
458 /* Detach new forked process? */
461 /* Before detaching from the child, remove all breakpoints
462 from it. If we forked, then this has already been taken
463 care of by infrun.c. If we vforked however, any
464 breakpoint inserted in the parent is visible in the
465 child, even those added while stopped in a vfork
466 catchpoint. This will remove the breakpoints from the
467 parent also, but they'll be reinserted below. */
470 /* Keep breakpoints list in sync. */
471 remove_breakpoints_inf (current_inferior ());
474 if (print_inferior_events
)
476 /* Ensure that we have a process ptid. */
477 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
479 target_terminal::ours_for_output ();
480 fprintf_filtered (gdb_stdlog
,
481 _("[Detaching after %s from child %s]\n"),
482 has_vforked
? "vfork" : "fork",
483 target_pid_to_str (process_ptid
).c_str ());
488 struct inferior
*parent_inf
, *child_inf
;
490 /* Add process to GDB's tables. */
491 child_inf
= add_inferior (child_ptid
.pid ());
493 parent_inf
= current_inferior ();
494 child_inf
->attach_flag
= parent_inf
->attach_flag
;
495 copy_terminal_info (child_inf
, parent_inf
);
496 child_inf
->gdbarch
= parent_inf
->gdbarch
;
497 copy_inferior_target_desc_info (child_inf
, parent_inf
);
499 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
501 set_current_inferior (child_inf
);
502 switch_to_no_thread ();
503 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
504 push_target (parent_inf
->process_target ());
505 thread_info
*child_thr
506 = add_thread_silent (child_inf
->process_target (), child_ptid
);
508 /* If this is a vfork child, then the address-space is
509 shared with the parent. */
512 child_inf
->pspace
= parent_inf
->pspace
;
513 child_inf
->aspace
= parent_inf
->aspace
;
517 /* The parent will be frozen until the child is done
518 with the shared region. Keep track of the
520 child_inf
->vfork_parent
= parent_inf
;
521 child_inf
->pending_detach
= 0;
522 parent_inf
->vfork_child
= child_inf
;
523 parent_inf
->pending_detach
= 0;
525 /* Now that the inferiors and program spaces are all
526 wired up, we can switch to the child thread (which
527 switches inferior and program space too). */
528 switch_to_thread (child_thr
);
532 child_inf
->aspace
= new_address_space ();
533 child_inf
->pspace
= new program_space (child_inf
->aspace
);
534 child_inf
->removable
= 1;
535 set_current_program_space (child_inf
->pspace
);
536 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
538 /* solib_create_inferior_hook relies on the current
540 switch_to_thread (child_thr
);
542 /* Let the shared library layer (e.g., solib-svr4) learn
543 about this new process, relocate the cloned exec, pull
544 in shared libraries, and install the solib event
545 breakpoint. If a "cloned-VM" event was propagated
546 better throughout the core, this wouldn't be
548 solib_create_inferior_hook (0);
554 struct inferior
*parent_inf
;
556 parent_inf
= current_inferior ();
558 /* If we detached from the child, then we have to be careful
559 to not insert breakpoints in the parent until the child
560 is done with the shared memory region. However, if we're
561 staying attached to the child, then we can and should
562 insert breakpoints, so that we can debug it. A
563 subsequent child exec or exit is enough to know when does
564 the child stops using the parent's address space. */
565 parent_inf
->waiting_for_vfork_done
= detach_fork
;
566 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
571 /* Follow the child. */
572 struct inferior
*parent_inf
, *child_inf
;
573 struct program_space
*parent_pspace
;
575 if (print_inferior_events
)
577 std::string parent_pid
= target_pid_to_str (parent_ptid
);
578 std::string child_pid
= target_pid_to_str (child_ptid
);
580 target_terminal::ours_for_output ();
581 fprintf_filtered (gdb_stdlog
,
582 _("[Attaching after %s %s to child %s]\n"),
584 has_vforked
? "vfork" : "fork",
588 /* Add the new inferior first, so that the target_detach below
589 doesn't unpush the target. */
591 child_inf
= add_inferior (child_ptid
.pid ());
593 parent_inf
= current_inferior ();
594 child_inf
->attach_flag
= parent_inf
->attach_flag
;
595 copy_terminal_info (child_inf
, parent_inf
);
596 child_inf
->gdbarch
= parent_inf
->gdbarch
;
597 copy_inferior_target_desc_info (child_inf
, parent_inf
);
599 parent_pspace
= parent_inf
->pspace
;
601 process_stratum_target
*target
= parent_inf
->process_target ();
604 /* Hold a strong reference to the target while (maybe)
605 detaching the parent. Otherwise detaching could close the
607 auto target_ref
= target_ops_ref::new_reference (target
);
609 /* If we're vforking, we want to hold on to the parent until
610 the child exits or execs. At child exec or exit time we
611 can remove the old breakpoints from the parent and detach
612 or resume debugging it. Otherwise, detach the parent now;
613 we'll want to reuse it's program/address spaces, but we
614 can't set them to the child before removing breakpoints
615 from the parent, otherwise, the breakpoints module could
616 decide to remove breakpoints from the wrong process (since
617 they'd be assigned to the same address space). */
621 gdb_assert (child_inf
->vfork_parent
== NULL
);
622 gdb_assert (parent_inf
->vfork_child
== NULL
);
623 child_inf
->vfork_parent
= parent_inf
;
624 child_inf
->pending_detach
= 0;
625 parent_inf
->vfork_child
= child_inf
;
626 parent_inf
->pending_detach
= detach_fork
;
627 parent_inf
->waiting_for_vfork_done
= 0;
629 else if (detach_fork
)
631 if (print_inferior_events
)
633 /* Ensure that we have a process ptid. */
634 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
636 target_terminal::ours_for_output ();
637 fprintf_filtered (gdb_stdlog
,
638 _("[Detaching after fork from "
640 target_pid_to_str (process_ptid
).c_str ());
643 target_detach (parent_inf
, 0);
647 /* Note that the detach above makes PARENT_INF dangling. */
649 /* Add the child thread to the appropriate lists, and switch
650 to this new thread, before cloning the program space, and
651 informing the solib layer about this new process. */
653 set_current_inferior (child_inf
);
654 push_target (target
);
657 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
659 /* If this is a vfork child, then the address-space is shared
660 with the parent. If we detached from the parent, then we can
661 reuse the parent's program/address spaces. */
662 if (has_vforked
|| detach_fork
)
664 child_inf
->pspace
= parent_pspace
;
665 child_inf
->aspace
= child_inf
->pspace
->aspace
;
671 child_inf
->aspace
= new_address_space ();
672 child_inf
->pspace
= new program_space (child_inf
->aspace
);
673 child_inf
->removable
= 1;
674 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
675 set_current_program_space (child_inf
->pspace
);
676 clone_program_space (child_inf
->pspace
, parent_pspace
);
678 /* Let the shared library layer (e.g., solib-svr4) learn
679 about this new process, relocate the cloned exec, pull in
680 shared libraries, and install the solib event breakpoint.
681 If a "cloned-VM" event was propagated better throughout
682 the core, this wouldn't be required. */
683 solib_create_inferior_hook (0);
686 switch_to_thread (child_thr
);
689 return target_follow_fork (follow_child
, detach_fork
);
692 /* Tell the target to follow the fork we're stopped at. Returns true
693 if the inferior should be resumed; false, if the target for some
694 reason decided it's best not to resume. */
699 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
700 bool should_resume
= true;
701 struct thread_info
*tp
;
703 /* Copy user stepping state to the new inferior thread. FIXME: the
704 followed fork child thread should have a copy of most of the
705 parent thread structure's run control related fields, not just these.
706 Initialized to avoid "may be used uninitialized" warnings from gcc. */
707 struct breakpoint
*step_resume_breakpoint
= NULL
;
708 struct breakpoint
*exception_resume_breakpoint
= NULL
;
709 CORE_ADDR step_range_start
= 0;
710 CORE_ADDR step_range_end
= 0;
711 int current_line
= 0;
712 symtab
*current_symtab
= NULL
;
713 struct frame_id step_frame_id
= { 0 };
714 struct thread_fsm
*thread_fsm
= NULL
;
718 process_stratum_target
*wait_target
;
720 struct target_waitstatus wait_status
;
722 /* Get the last target status returned by target_wait(). */
723 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
725 /* If not stopped at a fork event, then there's nothing else to
727 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
728 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
731 /* Check if we switched over from WAIT_PTID, since the event was
733 if (wait_ptid
!= minus_one_ptid
734 && (current_inferior ()->process_target () != wait_target
735 || inferior_ptid
!= wait_ptid
))
737 /* We did. Switch back to WAIT_PTID thread, to tell the
738 target to follow it (in either direction). We'll
739 afterwards refuse to resume, and inform the user what
741 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
742 switch_to_thread (wait_thread
);
743 should_resume
= false;
747 tp
= inferior_thread ();
749 /* If there were any forks/vforks that were caught and are now to be
750 followed, then do so now. */
751 switch (tp
->pending_follow
.kind
)
753 case TARGET_WAITKIND_FORKED
:
754 case TARGET_WAITKIND_VFORKED
:
756 ptid_t parent
, child
;
758 /* If the user did a next/step, etc, over a fork call,
759 preserve the stepping state in the fork child. */
760 if (follow_child
&& should_resume
)
762 step_resume_breakpoint
= clone_momentary_breakpoint
763 (tp
->control
.step_resume_breakpoint
);
764 step_range_start
= tp
->control
.step_range_start
;
765 step_range_end
= tp
->control
.step_range_end
;
766 current_line
= tp
->current_line
;
767 current_symtab
= tp
->current_symtab
;
768 step_frame_id
= tp
->control
.step_frame_id
;
769 exception_resume_breakpoint
770 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
771 thread_fsm
= tp
->thread_fsm
;
773 /* For now, delete the parent's sr breakpoint, otherwise,
774 parent/child sr breakpoints are considered duplicates,
775 and the child version will not be installed. Remove
776 this when the breakpoints module becomes aware of
777 inferiors and address spaces. */
778 delete_step_resume_breakpoint (tp
);
779 tp
->control
.step_range_start
= 0;
780 tp
->control
.step_range_end
= 0;
781 tp
->control
.step_frame_id
= null_frame_id
;
782 delete_exception_resume_breakpoint (tp
);
783 tp
->thread_fsm
= NULL
;
786 parent
= inferior_ptid
;
787 child
= tp
->pending_follow
.value
.related_pid
;
789 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
790 /* Set up inferior(s) as specified by the caller, and tell the
791 target to do whatever is necessary to follow either parent
793 if (follow_fork_inferior (follow_child
, detach_fork
))
795 /* Target refused to follow, or there's some other reason
796 we shouldn't resume. */
801 /* This pending follow fork event is now handled, one way
802 or another. The previous selected thread may be gone
803 from the lists by now, but if it is still around, need
804 to clear the pending follow request. */
805 tp
= find_thread_ptid (parent_targ
, parent
);
807 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
809 /* This makes sure we don't try to apply the "Switched
810 over from WAIT_PID" logic above. */
811 nullify_last_target_wait_ptid ();
813 /* If we followed the child, switch to it... */
816 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
817 switch_to_thread (child_thr
);
819 /* ... and preserve the stepping state, in case the
820 user was stepping over the fork call. */
823 tp
= inferior_thread ();
824 tp
->control
.step_resume_breakpoint
825 = step_resume_breakpoint
;
826 tp
->control
.step_range_start
= step_range_start
;
827 tp
->control
.step_range_end
= step_range_end
;
828 tp
->current_line
= current_line
;
829 tp
->current_symtab
= current_symtab
;
830 tp
->control
.step_frame_id
= step_frame_id
;
831 tp
->control
.exception_resume_breakpoint
832 = exception_resume_breakpoint
;
833 tp
->thread_fsm
= thread_fsm
;
837 /* If we get here, it was because we're trying to
838 resume from a fork catchpoint, but, the user
839 has switched threads away from the thread that
840 forked. In that case, the resume command
841 issued is most likely not applicable to the
842 child, so just warn, and refuse to resume. */
843 warning (_("Not resuming: switched threads "
844 "before following fork child."));
847 /* Reset breakpoints in the child as appropriate. */
848 follow_inferior_reset_breakpoints ();
853 case TARGET_WAITKIND_SPURIOUS
:
854 /* Nothing to follow. */
857 internal_error (__FILE__
, __LINE__
,
858 "Unexpected pending_follow.kind %d\n",
859 tp
->pending_follow
.kind
);
863 return should_resume
;
867 follow_inferior_reset_breakpoints (void)
869 struct thread_info
*tp
= inferior_thread ();
871 /* Was there a step_resume breakpoint? (There was if the user
872 did a "next" at the fork() call.) If so, explicitly reset its
873 thread number. Cloned step_resume breakpoints are disabled on
874 creation, so enable it here now that it is associated with the
877 step_resumes are a form of bp that are made to be per-thread.
878 Since we created the step_resume bp when the parent process
879 was being debugged, and now are switching to the child process,
880 from the breakpoint package's viewpoint, that's a switch of
881 "threads". We must update the bp's notion of which thread
882 it is for, or it'll be ignored when it triggers. */
884 if (tp
->control
.step_resume_breakpoint
)
886 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
887 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
890 /* Treat exception_resume breakpoints like step_resume breakpoints. */
891 if (tp
->control
.exception_resume_breakpoint
)
893 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
894 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
897 /* Reinsert all breakpoints in the child. The user may have set
898 breakpoints after catching the fork, in which case those
899 were never set in the child, but only in the parent. This makes
900 sure the inserted breakpoints match the breakpoint list. */
902 breakpoint_re_set ();
903 insert_breakpoints ();
906 /* The child has exited or execed: resume threads of the parent the
907 user wanted to be executing. */
910 proceed_after_vfork_done (struct thread_info
*thread
,
913 int pid
= * (int *) arg
;
915 if (thread
->ptid
.pid () == pid
916 && thread
->state
== THREAD_RUNNING
917 && !thread
->executing
918 && !thread
->stop_requested
919 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
921 infrun_log_debug ("resuming vfork parent thread %s",
922 target_pid_to_str (thread
->ptid
).c_str ());
924 switch_to_thread (thread
);
925 clear_proceed_status (0);
926 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
932 /* Called whenever we notice an exec or exit event, to handle
933 detaching or resuming a vfork parent. */
936 handle_vfork_child_exec_or_exit (int exec
)
938 struct inferior
*inf
= current_inferior ();
940 if (inf
->vfork_parent
)
942 int resume_parent
= -1;
944 /* This exec or exit marks the end of the shared memory region
945 between the parent and the child. Break the bonds. */
946 inferior
*vfork_parent
= inf
->vfork_parent
;
947 inf
->vfork_parent
->vfork_child
= NULL
;
948 inf
->vfork_parent
= NULL
;
950 /* If the user wanted to detach from the parent, now is the
952 if (vfork_parent
->pending_detach
)
954 struct program_space
*pspace
;
955 struct address_space
*aspace
;
957 /* follow-fork child, detach-on-fork on. */
959 vfork_parent
->pending_detach
= 0;
961 scoped_restore_current_pspace_and_thread restore_thread
;
963 /* We're letting loose of the parent. */
964 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
965 switch_to_thread (tp
);
967 /* We're about to detach from the parent, which implicitly
968 removes breakpoints from its address space. There's a
969 catch here: we want to reuse the spaces for the child,
970 but, parent/child are still sharing the pspace at this
971 point, although the exec in reality makes the kernel give
972 the child a fresh set of new pages. The problem here is
973 that the breakpoints module being unaware of this, would
974 likely chose the child process to write to the parent
975 address space. Swapping the child temporarily away from
976 the spaces has the desired effect. Yes, this is "sort
979 pspace
= inf
->pspace
;
980 aspace
= inf
->aspace
;
984 if (print_inferior_events
)
987 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
989 target_terminal::ours_for_output ();
993 fprintf_filtered (gdb_stdlog
,
994 _("[Detaching vfork parent %s "
995 "after child exec]\n"), pidstr
.c_str ());
999 fprintf_filtered (gdb_stdlog
,
1000 _("[Detaching vfork parent %s "
1001 "after child exit]\n"), pidstr
.c_str ());
1005 target_detach (vfork_parent
, 0);
1008 inf
->pspace
= pspace
;
1009 inf
->aspace
= aspace
;
1013 /* We're staying attached to the parent, so, really give the
1014 child a new address space. */
1015 inf
->pspace
= new program_space (maybe_new_address_space ());
1016 inf
->aspace
= inf
->pspace
->aspace
;
1018 set_current_program_space (inf
->pspace
);
1020 resume_parent
= vfork_parent
->pid
;
1024 /* If this is a vfork child exiting, then the pspace and
1025 aspaces were shared with the parent. Since we're
1026 reporting the process exit, we'll be mourning all that is
1027 found in the address space, and switching to null_ptid,
1028 preparing to start a new inferior. But, since we don't
1029 want to clobber the parent's address/program spaces, we
1030 go ahead and create a new one for this exiting
1033 /* Switch to no-thread while running clone_program_space, so
1034 that clone_program_space doesn't want to read the
1035 selected frame of a dead process. */
1036 scoped_restore_current_thread restore_thread
;
1037 switch_to_no_thread ();
1039 inf
->pspace
= new program_space (maybe_new_address_space ());
1040 inf
->aspace
= inf
->pspace
->aspace
;
1041 set_current_program_space (inf
->pspace
);
1043 inf
->symfile_flags
= SYMFILE_NO_READ
;
1044 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1046 resume_parent
= vfork_parent
->pid
;
1049 gdb_assert (current_program_space
== inf
->pspace
);
1051 if (non_stop
&& resume_parent
!= -1)
1053 /* If the user wanted the parent to be running, let it go
1055 scoped_restore_current_thread restore_thread
;
1057 infrun_log_debug ("resuming vfork parent process %d",
1060 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1065 /* Enum strings for "set|show follow-exec-mode". */
1067 static const char follow_exec_mode_new
[] = "new";
1068 static const char follow_exec_mode_same
[] = "same";
1069 static const char *const follow_exec_mode_names
[] =
1071 follow_exec_mode_new
,
1072 follow_exec_mode_same
,
1076 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1078 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1079 struct cmd_list_element
*c
, const char *value
)
1081 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1084 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1087 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1089 struct inferior
*inf
= current_inferior ();
1090 int pid
= ptid
.pid ();
1091 ptid_t process_ptid
;
1093 /* Switch terminal for any messages produced e.g. by
1094 breakpoint_re_set. */
1095 target_terminal::ours_for_output ();
1097 /* This is an exec event that we actually wish to pay attention to.
1098 Refresh our symbol table to the newly exec'd program, remove any
1099 momentary bp's, etc.
1101 If there are breakpoints, they aren't really inserted now,
1102 since the exec() transformed our inferior into a fresh set
1105 We want to preserve symbolic breakpoints on the list, since
1106 we have hopes that they can be reset after the new a.out's
1107 symbol table is read.
1109 However, any "raw" breakpoints must be removed from the list
1110 (e.g., the solib bp's), since their address is probably invalid
1113 And, we DON'T want to call delete_breakpoints() here, since
1114 that may write the bp's "shadow contents" (the instruction
1115 value that was overwritten with a TRAP instruction). Since
1116 we now have a new a.out, those shadow contents aren't valid. */
1118 mark_breakpoints_out ();
1120 /* The target reports the exec event to the main thread, even if
1121 some other thread does the exec, and even if the main thread was
1122 stopped or already gone. We may still have non-leader threads of
1123 the process on our list. E.g., on targets that don't have thread
1124 exit events (like remote); or on native Linux in non-stop mode if
1125 there were only two threads in the inferior and the non-leader
1126 one is the one that execs (and nothing forces an update of the
1127 thread list up to here). When debugging remotely, it's best to
1128 avoid extra traffic, when possible, so avoid syncing the thread
1129 list with the target, and instead go ahead and delete all threads
1130 of the process but one that reported the event. Note this must
1131 be done before calling update_breakpoints_after_exec, as
1132 otherwise clearing the threads' resources would reference stale
1133 thread breakpoints -- it may have been one of these threads that
1134 stepped across the exec. We could just clear their stepping
1135 states, but as long as we're iterating, might as well delete
1136 them. Deleting them now rather than at the next user-visible
1137 stop provides a nicer sequence of events for user and MI
1139 for (thread_info
*th
: all_threads_safe ())
1140 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1143 /* We also need to clear any left over stale state for the
1144 leader/event thread. E.g., if there was any step-resume
1145 breakpoint or similar, it's gone now. We cannot truly
1146 step-to-next statement through an exec(). */
1147 thread_info
*th
= inferior_thread ();
1148 th
->control
.step_resume_breakpoint
= NULL
;
1149 th
->control
.exception_resume_breakpoint
= NULL
;
1150 th
->control
.single_step_breakpoints
= NULL
;
1151 th
->control
.step_range_start
= 0;
1152 th
->control
.step_range_end
= 0;
1154 /* The user may have had the main thread held stopped in the
1155 previous image (e.g., schedlock on, or non-stop). Release
1157 th
->stop_requested
= 0;
1159 update_breakpoints_after_exec ();
1161 /* What is this a.out's name? */
1162 process_ptid
= ptid_t (pid
);
1163 printf_unfiltered (_("%s is executing new program: %s\n"),
1164 target_pid_to_str (process_ptid
).c_str (),
1167 /* We've followed the inferior through an exec. Therefore, the
1168 inferior has essentially been killed & reborn. */
1170 breakpoint_init_inferior (inf_execd
);
1172 gdb::unique_xmalloc_ptr
<char> exec_file_host
1173 = exec_file_find (exec_file_target
, NULL
);
1175 /* If we were unable to map the executable target pathname onto a host
1176 pathname, tell the user that. Otherwise GDB's subsequent behavior
1177 is confusing. Maybe it would even be better to stop at this point
1178 so that the user can specify a file manually before continuing. */
1179 if (exec_file_host
== NULL
)
1180 warning (_("Could not load symbols for executable %s.\n"
1181 "Do you need \"set sysroot\"?"),
1184 /* Reset the shared library package. This ensures that we get a
1185 shlib event when the child reaches "_start", at which point the
1186 dld will have had a chance to initialize the child. */
1187 /* Also, loading a symbol file below may trigger symbol lookups, and
1188 we don't want those to be satisfied by the libraries of the
1189 previous incarnation of this process. */
1190 no_shared_libraries (NULL
, 0);
1192 if (follow_exec_mode_string
== follow_exec_mode_new
)
1194 /* The user wants to keep the old inferior and program spaces
1195 around. Create a new fresh one, and switch to it. */
1197 /* Do exit processing for the original inferior before setting the new
1198 inferior's pid. Having two inferiors with the same pid would confuse
1199 find_inferior_p(t)id. Transfer the terminal state and info from the
1200 old to the new inferior. */
1201 inf
= add_inferior_with_spaces ();
1202 swap_terminal_info (inf
, current_inferior ());
1203 exit_inferior_silent (current_inferior ());
1206 target_follow_exec (inf
, exec_file_target
);
1208 inferior
*org_inferior
= current_inferior ();
1209 switch_to_inferior_no_thread (inf
);
1210 push_target (org_inferior
->process_target ());
1211 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1212 switch_to_thread (thr
);
1216 /* The old description may no longer be fit for the new image.
1217 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1218 old description; we'll read a new one below. No need to do
1219 this on "follow-exec-mode new", as the old inferior stays
1220 around (its description is later cleared/refetched on
1222 target_clear_description ();
1225 gdb_assert (current_program_space
== inf
->pspace
);
1227 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1228 because the proper displacement for a PIE (Position Independent
1229 Executable) main symbol file will only be computed by
1230 solib_create_inferior_hook below. breakpoint_re_set would fail
1231 to insert the breakpoints with the zero displacement. */
1232 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1234 /* If the target can specify a description, read it. Must do this
1235 after flipping to the new executable (because the target supplied
1236 description must be compatible with the executable's
1237 architecture, and the old executable may e.g., be 32-bit, while
1238 the new one 64-bit), and before anything involving memory or
1240 target_find_description ();
1242 solib_create_inferior_hook (0);
1244 jit_inferior_created_hook ();
1246 breakpoint_re_set ();
1248 /* Reinsert all breakpoints. (Those which were symbolic have
1249 been reset to the proper address in the new a.out, thanks
1250 to symbol_file_command...). */
1251 insert_breakpoints ();
1253 /* The next resume of this inferior should bring it to the shlib
1254 startup breakpoints. (If the user had also set bp's on
1255 "main" from the old (parent) process, then they'll auto-
1256 matically get reset there in the new process.). */
1259 /* The queue of threads that need to do a step-over operation to get
1260 past e.g., a breakpoint. What technique is used to step over the
1261 breakpoint/watchpoint does not matter -- all threads end up in the
1262 same queue, to maintain rough temporal order of execution, in order
1263 to avoid starvation, otherwise, we could e.g., find ourselves
1264 constantly stepping the same couple threads past their breakpoints
1265 over and over, if the single-step finish fast enough. */
1266 struct thread_info
*global_thread_step_over_chain_head
;
1268 /* Bit flags indicating what the thread needs to step over. */
1270 enum step_over_what_flag
1272 /* Step over a breakpoint. */
1273 STEP_OVER_BREAKPOINT
= 1,
1275 /* Step past a non-continuable watchpoint, in order to let the
1276 instruction execute so we can evaluate the watchpoint
1278 STEP_OVER_WATCHPOINT
= 2
1280 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1282 /* Info about an instruction that is being stepped over. */
1284 struct step_over_info
1286 /* If we're stepping past a breakpoint, this is the address space
1287 and address of the instruction the breakpoint is set at. We'll
1288 skip inserting all breakpoints here. Valid iff ASPACE is
1290 const address_space
*aspace
;
1293 /* The instruction being stepped over triggers a nonsteppable
1294 watchpoint. If true, we'll skip inserting watchpoints. */
1295 int nonsteppable_watchpoint_p
;
1297 /* The thread's global number. */
1301 /* The step-over info of the location that is being stepped over.
1303 Note that with async/breakpoint always-inserted mode, a user might
1304 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1305 being stepped over. As setting a new breakpoint inserts all
1306 breakpoints, we need to make sure the breakpoint being stepped over
1307 isn't inserted then. We do that by only clearing the step-over
1308 info when the step-over is actually finished (or aborted).
1310 Presently GDB can only step over one breakpoint at any given time.
1311 Given threads that can't run code in the same address space as the
1312 breakpoint's can't really miss the breakpoint, GDB could be taught
1313 to step-over at most one breakpoint per address space (so this info
1314 could move to the address space object if/when GDB is extended).
1315 The set of breakpoints being stepped over will normally be much
1316 smaller than the set of all breakpoints, so a flag in the
1317 breakpoint location structure would be wasteful. A separate list
1318 also saves complexity and run-time, as otherwise we'd have to go
1319 through all breakpoint locations clearing their flag whenever we
1320 start a new sequence. Similar considerations weigh against storing
1321 this info in the thread object. Plus, not all step overs actually
1322 have breakpoint locations -- e.g., stepping past a single-step
1323 breakpoint, or stepping to complete a non-continuable
1325 static struct step_over_info step_over_info
;
1327 /* Record the address of the breakpoint/instruction we're currently
1329 N.B. We record the aspace and address now, instead of say just the thread,
1330 because when we need the info later the thread may be running. */
1333 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1334 int nonsteppable_watchpoint_p
,
1337 step_over_info
.aspace
= aspace
;
1338 step_over_info
.address
= address
;
1339 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1340 step_over_info
.thread
= thread
;
1343 /* Called when we're not longer stepping over a breakpoint / an
1344 instruction, so all breakpoints are free to be (re)inserted. */
1347 clear_step_over_info (void)
1349 infrun_log_debug ("clearing step over info");
1350 step_over_info
.aspace
= NULL
;
1351 step_over_info
.address
= 0;
1352 step_over_info
.nonsteppable_watchpoint_p
= 0;
1353 step_over_info
.thread
= -1;
1359 stepping_past_instruction_at (struct address_space
*aspace
,
1362 return (step_over_info
.aspace
!= NULL
1363 && breakpoint_address_match (aspace
, address
,
1364 step_over_info
.aspace
,
1365 step_over_info
.address
));
1371 thread_is_stepping_over_breakpoint (int thread
)
1373 return (step_over_info
.thread
!= -1
1374 && thread
== step_over_info
.thread
);
1380 stepping_past_nonsteppable_watchpoint (void)
1382 return step_over_info
.nonsteppable_watchpoint_p
;
1385 /* Returns true if step-over info is valid. */
1388 step_over_info_valid_p (void)
1390 return (step_over_info
.aspace
!= NULL
1391 || stepping_past_nonsteppable_watchpoint ());
1395 /* Displaced stepping. */
1397 /* In non-stop debugging mode, we must take special care to manage
1398 breakpoints properly; in particular, the traditional strategy for
1399 stepping a thread past a breakpoint it has hit is unsuitable.
1400 'Displaced stepping' is a tactic for stepping one thread past a
1401 breakpoint it has hit while ensuring that other threads running
1402 concurrently will hit the breakpoint as they should.
1404 The traditional way to step a thread T off a breakpoint in a
1405 multi-threaded program in all-stop mode is as follows:
1407 a0) Initially, all threads are stopped, and breakpoints are not
1409 a1) We single-step T, leaving breakpoints uninserted.
1410 a2) We insert breakpoints, and resume all threads.
1412 In non-stop debugging, however, this strategy is unsuitable: we
1413 don't want to have to stop all threads in the system in order to
1414 continue or step T past a breakpoint. Instead, we use displaced
1417 n0) Initially, T is stopped, other threads are running, and
1418 breakpoints are inserted.
1419 n1) We copy the instruction "under" the breakpoint to a separate
1420 location, outside the main code stream, making any adjustments
1421 to the instruction, register, and memory state as directed by
1423 n2) We single-step T over the instruction at its new location.
1424 n3) We adjust the resulting register and memory state as directed
1425 by T's architecture. This includes resetting T's PC to point
1426 back into the main instruction stream.
1429 This approach depends on the following gdbarch methods:
1431 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1432 indicate where to copy the instruction, and how much space must
1433 be reserved there. We use these in step n1.
1435 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1436 address, and makes any necessary adjustments to the instruction,
1437 register contents, and memory. We use this in step n1.
1439 - gdbarch_displaced_step_fixup adjusts registers and memory after
1440 we have successfully single-stepped the instruction, to yield the
1441 same effect the instruction would have had if we had executed it
1442 at its original address. We use this in step n3.
1444 The gdbarch_displaced_step_copy_insn and
1445 gdbarch_displaced_step_fixup functions must be written so that
1446 copying an instruction with gdbarch_displaced_step_copy_insn,
1447 single-stepping across the copied instruction, and then applying
1448 gdbarch_displaced_insn_fixup should have the same effects on the
1449 thread's memory and registers as stepping the instruction in place
1450 would have. Exactly which responsibilities fall to the copy and
1451 which fall to the fixup is up to the author of those functions.
1453 See the comments in gdbarch.sh for details.
1455 Note that displaced stepping and software single-step cannot
1456 currently be used in combination, although with some care I think
1457 they could be made to. Software single-step works by placing
1458 breakpoints on all possible subsequent instructions; if the
1459 displaced instruction is a PC-relative jump, those breakpoints
1460 could fall in very strange places --- on pages that aren't
1461 executable, or at addresses that are not proper instruction
1462 boundaries. (We do generally let other threads run while we wait
1463 to hit the software single-step breakpoint, and they might
1464 encounter such a corrupted instruction.) One way to work around
1465 this would be to have gdbarch_displaced_step_copy_insn fully
1466 simulate the effect of PC-relative instructions (and return NULL)
1467 on architectures that use software single-stepping.
1469 In non-stop mode, we can have independent and simultaneous step
1470 requests, so more than one thread may need to simultaneously step
1471 over a breakpoint. The current implementation assumes there is
1472 only one scratch space per process. In this case, we have to
1473 serialize access to the scratch space. If thread A wants to step
1474 over a breakpoint, but we are currently waiting for some other
1475 thread to complete a displaced step, we leave thread A stopped and
1476 place it in the displaced_step_request_queue. Whenever a displaced
1477 step finishes, we pick the next thread in the queue and start a new
1478 displaced step operation on it. See displaced_step_prepare and
1479 displaced_step_fixup for details. */
1481 /* Default destructor for displaced_step_closure. */
1483 displaced_step_closure::~displaced_step_closure () = default;
1485 /* Get the displaced stepping state of process PID. */
1487 static displaced_step_inferior_state
*
1488 get_displaced_stepping_state (inferior
*inf
)
1490 return &inf
->displaced_step_state
;
1493 /* Returns true if any inferior has a thread doing a displaced
1497 displaced_step_in_progress_any_inferior ()
1499 for (inferior
*i
: all_inferiors ())
1501 if (i
->displaced_step_state
.step_thread
!= nullptr)
1508 /* Return true if thread represented by PTID is doing a displaced
1512 displaced_step_in_progress_thread (thread_info
*thread
)
1514 gdb_assert (thread
!= NULL
);
1516 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1519 /* Return true if process PID has a thread doing a displaced step. */
1522 displaced_step_in_progress (inferior
*inf
)
1524 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1527 /* If inferior is in displaced stepping, and ADDR equals to starting address
1528 of copy area, return corresponding displaced_step_closure. Otherwise,
1531 struct displaced_step_closure
*
1532 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1534 displaced_step_inferior_state
*displaced
1535 = get_displaced_stepping_state (current_inferior ());
1537 /* If checking the mode of displaced instruction in copy area. */
1538 if (displaced
->step_thread
!= nullptr
1539 && displaced
->step_copy
== addr
)
1540 return displaced
->step_closure
.get ();
1546 infrun_inferior_exit (struct inferior
*inf
)
1548 inf
->displaced_step_state
.reset ();
1551 /* If ON, and the architecture supports it, GDB will use displaced
1552 stepping to step over breakpoints. If OFF, or if the architecture
1553 doesn't support it, GDB will instead use the traditional
1554 hold-and-step approach. If AUTO (which is the default), GDB will
1555 decide which technique to use to step over breakpoints depending on
1556 whether the target works in a non-stop way (see use_displaced_stepping). */
1558 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1561 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1562 struct cmd_list_element
*c
,
1565 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1566 fprintf_filtered (file
,
1567 _("Debugger's willingness to use displaced stepping "
1568 "to step over breakpoints is %s (currently %s).\n"),
1569 value
, target_is_non_stop_p () ? "on" : "off");
1571 fprintf_filtered (file
,
1572 _("Debugger's willingness to use displaced stepping "
1573 "to step over breakpoints is %s.\n"), value
);
1576 /* Return true if the gdbarch implements the required methods to use
1577 displaced stepping. */
1580 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1582 /* Only check for the presence of step_copy_insn. Other required methods
1583 are checked by the gdbarch validation. */
1584 return gdbarch_displaced_step_copy_insn_p (arch
);
1587 /* Return non-zero if displaced stepping can/should be used to step
1588 over breakpoints of thread TP. */
1591 use_displaced_stepping (thread_info
*tp
)
1593 /* If the user disabled it explicitly, don't use displaced stepping. */
1594 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1597 /* If "auto", only use displaced stepping if the target operates in a non-stop
1599 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1600 && !target_is_non_stop_p ())
1603 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1605 /* If the architecture doesn't implement displaced stepping, don't use
1607 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1610 /* If recording, don't use displaced stepping. */
1611 if (find_record_target () != nullptr)
1614 displaced_step_inferior_state
*displaced_state
1615 = get_displaced_stepping_state (tp
->inf
);
1617 /* If displaced stepping failed before for this inferior, don't bother trying
1619 if (displaced_state
->failed_before
)
1625 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1628 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1630 displaced
->reset ();
1633 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1634 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1636 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1638 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1640 displaced_step_dump_bytes (struct ui_file
*file
,
1641 const gdb_byte
*buf
,
1646 for (i
= 0; i
< len
; i
++)
1647 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1648 fputs_unfiltered ("\n", file
);
1651 /* Prepare to single-step, using displaced stepping.
1653 Note that we cannot use displaced stepping when we have a signal to
1654 deliver. If we have a signal to deliver and an instruction to step
1655 over, then after the step, there will be no indication from the
1656 target whether the thread entered a signal handler or ignored the
1657 signal and stepped over the instruction successfully --- both cases
1658 result in a simple SIGTRAP. In the first case we mustn't do a
1659 fixup, and in the second case we must --- but we can't tell which.
1660 Comments in the code for 'random signals' in handle_inferior_event
1661 explain how we handle this case instead.
1663 Returns 1 if preparing was successful -- this thread is going to be
1664 stepped now; 0 if displaced stepping this thread got queued; or -1
1665 if this instruction can't be displaced stepped. */
1668 displaced_step_prepare_throw (thread_info
*tp
)
1670 regcache
*regcache
= get_thread_regcache (tp
);
1671 struct gdbarch
*gdbarch
= regcache
->arch ();
1672 const address_space
*aspace
= regcache
->aspace ();
1673 CORE_ADDR original
, copy
;
1677 /* We should never reach this function if the architecture does not
1678 support displaced stepping. */
1679 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1681 /* Nor if the thread isn't meant to step over a breakpoint. */
1682 gdb_assert (tp
->control
.trap_expected
);
1684 /* Disable range stepping while executing in the scratch pad. We
1685 want a single-step even if executing the displaced instruction in
1686 the scratch buffer lands within the stepping range (e.g., a
1688 tp
->control
.may_range_step
= 0;
1690 /* We have to displaced step one thread at a time, as we only have
1691 access to a single scratch space per inferior. */
1693 displaced_step_inferior_state
*displaced
1694 = get_displaced_stepping_state (tp
->inf
);
1696 if (displaced
->step_thread
!= nullptr)
1698 /* Already waiting for a displaced step to finish. Defer this
1699 request and place in queue. */
1701 if (debug_displaced
)
1702 fprintf_unfiltered (gdb_stdlog
,
1703 "displaced: deferring step of %s\n",
1704 target_pid_to_str (tp
->ptid
).c_str ());
1706 global_thread_step_over_chain_enqueue (tp
);
1711 if (debug_displaced
)
1712 fprintf_unfiltered (gdb_stdlog
,
1713 "displaced: stepping %s now\n",
1714 target_pid_to_str (tp
->ptid
).c_str ());
1717 displaced_step_reset (displaced
);
1719 scoped_restore_current_thread restore_thread
;
1721 switch_to_thread (tp
);
1723 original
= regcache_read_pc (regcache
);
1725 copy
= gdbarch_displaced_step_location (gdbarch
);
1726 len
= gdbarch_max_insn_length (gdbarch
);
1728 if (breakpoint_in_range_p (aspace
, copy
, len
))
1730 /* There's a breakpoint set in the scratch pad location range
1731 (which is usually around the entry point). We'd either
1732 install it before resuming, which would overwrite/corrupt the
1733 scratch pad, or if it was already inserted, this displaced
1734 step would overwrite it. The latter is OK in the sense that
1735 we already assume that no thread is going to execute the code
1736 in the scratch pad range (after initial startup) anyway, but
1737 the former is unacceptable. Simply punt and fallback to
1738 stepping over this breakpoint in-line. */
1739 if (debug_displaced
)
1741 fprintf_unfiltered (gdb_stdlog
,
1742 "displaced: breakpoint set in scratch pad. "
1743 "Stepping over breakpoint in-line instead.\n");
1749 /* Save the original contents of the copy area. */
1750 displaced
->step_saved_copy
.resize (len
);
1751 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1753 throw_error (MEMORY_ERROR
,
1754 _("Error accessing memory address %s (%s) for "
1755 "displaced-stepping scratch space."),
1756 paddress (gdbarch
, copy
), safe_strerror (status
));
1757 if (debug_displaced
)
1759 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1760 paddress (gdbarch
, copy
));
1761 displaced_step_dump_bytes (gdb_stdlog
,
1762 displaced
->step_saved_copy
.data (),
1766 displaced
->step_closure
1767 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1768 if (displaced
->step_closure
== NULL
)
1770 /* The architecture doesn't know how or want to displaced step
1771 this instruction or instruction sequence. Fallback to
1772 stepping over the breakpoint in-line. */
1776 /* Save the information we need to fix things up if the step
1778 displaced
->step_thread
= tp
;
1779 displaced
->step_gdbarch
= gdbarch
;
1780 displaced
->step_original
= original
;
1781 displaced
->step_copy
= copy
;
1784 displaced_step_reset_cleanup
cleanup (displaced
);
1786 /* Resume execution at the copy. */
1787 regcache_write_pc (regcache
, copy
);
1792 if (debug_displaced
)
1793 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1794 paddress (gdbarch
, copy
));
1799 /* Wrapper for displaced_step_prepare_throw that disabled further
1800 attempts at displaced stepping if we get a memory error. */
1803 displaced_step_prepare (thread_info
*thread
)
1809 prepared
= displaced_step_prepare_throw (thread
);
1811 catch (const gdb_exception_error
&ex
)
1813 struct displaced_step_inferior_state
*displaced_state
;
1815 if (ex
.error
!= MEMORY_ERROR
1816 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1819 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1822 /* Be verbose if "set displaced-stepping" is "on", silent if
1824 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1826 warning (_("disabling displaced stepping: %s"),
1830 /* Disable further displaced stepping attempts. */
1832 = get_displaced_stepping_state (thread
->inf
);
1833 displaced_state
->failed_before
= 1;
1840 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1841 const gdb_byte
*myaddr
, int len
)
1843 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1845 inferior_ptid
= ptid
;
1846 write_memory (memaddr
, myaddr
, len
);
1849 /* Restore the contents of the copy area for thread PTID. */
1852 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1855 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1857 write_memory_ptid (ptid
, displaced
->step_copy
,
1858 displaced
->step_saved_copy
.data (), len
);
1859 if (debug_displaced
)
1860 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1861 target_pid_to_str (ptid
).c_str (),
1862 paddress (displaced
->step_gdbarch
,
1863 displaced
->step_copy
));
1866 /* If we displaced stepped an instruction successfully, adjust
1867 registers and memory to yield the same effect the instruction would
1868 have had if we had executed it at its original address, and return
1869 1. If the instruction didn't complete, relocate the PC and return
1870 -1. If the thread wasn't displaced stepping, return 0. */
1873 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1875 struct displaced_step_inferior_state
*displaced
1876 = get_displaced_stepping_state (event_thread
->inf
);
1879 /* Was this event for the thread we displaced? */
1880 if (displaced
->step_thread
!= event_thread
)
1883 /* Fixup may need to read memory/registers. Switch to the thread
1884 that we're fixing up. Also, target_stopped_by_watchpoint checks
1885 the current thread, and displaced_step_restore performs ptid-dependent
1886 memory accesses using current_inferior() and current_top_target(). */
1887 switch_to_thread (event_thread
);
1889 displaced_step_reset_cleanup
cleanup (displaced
);
1891 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1893 /* Did the instruction complete successfully? */
1894 if (signal
== GDB_SIGNAL_TRAP
1895 && !(target_stopped_by_watchpoint ()
1896 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1897 || target_have_steppable_watchpoint
)))
1899 /* Fix up the resulting state. */
1900 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1901 displaced
->step_closure
.get (),
1902 displaced
->step_original
,
1903 displaced
->step_copy
,
1904 get_thread_regcache (displaced
->step_thread
));
1909 /* Since the instruction didn't complete, all we can do is
1911 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1912 CORE_ADDR pc
= regcache_read_pc (regcache
);
1914 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1915 regcache_write_pc (regcache
, pc
);
1922 /* Data to be passed around while handling an event. This data is
1923 discarded between events. */
1924 struct execution_control_state
1926 process_stratum_target
*target
;
1928 /* The thread that got the event, if this was a thread event; NULL
1930 struct thread_info
*event_thread
;
1932 struct target_waitstatus ws
;
1933 int stop_func_filled_in
;
1934 CORE_ADDR stop_func_start
;
1935 CORE_ADDR stop_func_end
;
1936 const char *stop_func_name
;
1939 /* True if the event thread hit the single-step breakpoint of
1940 another thread. Thus the event doesn't cause a stop, the thread
1941 needs to be single-stepped past the single-step breakpoint before
1942 we can switch back to the original stepping thread. */
1943 int hit_singlestep_breakpoint
;
1946 /* Clear ECS and set it to point at TP. */
1949 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1951 memset (ecs
, 0, sizeof (*ecs
));
1952 ecs
->event_thread
= tp
;
1953 ecs
->ptid
= tp
->ptid
;
1956 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1957 static void prepare_to_wait (struct execution_control_state
*ecs
);
1958 static int keep_going_stepped_thread (struct thread_info
*tp
);
1959 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1961 /* Are there any pending step-over requests? If so, run all we can
1962 now and return true. Otherwise, return false. */
1965 start_step_over (void)
1967 struct thread_info
*tp
, *next
;
1969 /* Don't start a new step-over if we already have an in-line
1970 step-over operation ongoing. */
1971 if (step_over_info_valid_p ())
1974 for (tp
= global_thread_step_over_chain_head
; tp
!= NULL
; tp
= next
)
1976 struct execution_control_state ecss
;
1977 struct execution_control_state
*ecs
= &ecss
;
1978 step_over_what step_what
;
1979 int must_be_in_line
;
1981 gdb_assert (!tp
->stop_requested
);
1983 next
= global_thread_step_over_chain_next (tp
);
1985 /* If this inferior already has a displaced step in process,
1986 don't start a new one. */
1987 if (displaced_step_in_progress (tp
->inf
))
1990 step_what
= thread_still_needs_step_over (tp
);
1991 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1992 || ((step_what
& STEP_OVER_BREAKPOINT
)
1993 && !use_displaced_stepping (tp
)));
1995 /* We currently stop all threads of all processes to step-over
1996 in-line. If we need to start a new in-line step-over, let
1997 any pending displaced steps finish first. */
1998 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
2001 global_thread_step_over_chain_remove (tp
);
2003 if (global_thread_step_over_chain_head
== NULL
)
2004 infrun_log_debug ("step-over queue now empty");
2006 if (tp
->control
.trap_expected
2010 internal_error (__FILE__
, __LINE__
,
2011 "[%s] has inconsistent state: "
2012 "trap_expected=%d, resumed=%d, executing=%d\n",
2013 target_pid_to_str (tp
->ptid
).c_str (),
2014 tp
->control
.trap_expected
,
2019 infrun_log_debug ("resuming [%s] for step-over",
2020 target_pid_to_str (tp
->ptid
).c_str ());
2022 /* keep_going_pass_signal skips the step-over if the breakpoint
2023 is no longer inserted. In all-stop, we want to keep looking
2024 for a thread that needs a step-over instead of resuming TP,
2025 because we wouldn't be able to resume anything else until the
2026 target stops again. In non-stop, the resume always resumes
2027 only TP, so it's OK to let the thread resume freely. */
2028 if (!target_is_non_stop_p () && !step_what
)
2031 switch_to_thread (tp
);
2032 reset_ecs (ecs
, tp
);
2033 keep_going_pass_signal (ecs
);
2035 if (!ecs
->wait_some_more
)
2036 error (_("Command aborted."));
2038 gdb_assert (tp
->resumed
);
2040 /* If we started a new in-line step-over, we're done. */
2041 if (step_over_info_valid_p ())
2043 gdb_assert (tp
->control
.trap_expected
);
2047 if (!target_is_non_stop_p ())
2049 /* On all-stop, shouldn't have resumed unless we needed a
2051 gdb_assert (tp
->control
.trap_expected
2052 || tp
->step_after_step_resume_breakpoint
);
2054 /* With remote targets (at least), in all-stop, we can't
2055 issue any further remote commands until the program stops
2060 /* Either the thread no longer needed a step-over, or a new
2061 displaced stepping sequence started. Even in the latter
2062 case, continue looking. Maybe we can also start another
2063 displaced step on a thread of other process. */
2069 /* Update global variables holding ptids to hold NEW_PTID if they were
2070 holding OLD_PTID. */
2072 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2074 if (inferior_ptid
== old_ptid
)
2075 inferior_ptid
= new_ptid
;
2080 static const char schedlock_off
[] = "off";
2081 static const char schedlock_on
[] = "on";
2082 static const char schedlock_step
[] = "step";
2083 static const char schedlock_replay
[] = "replay";
2084 static const char *const scheduler_enums
[] = {
2091 static const char *scheduler_mode
= schedlock_replay
;
2093 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2094 struct cmd_list_element
*c
, const char *value
)
2096 fprintf_filtered (file
,
2097 _("Mode for locking scheduler "
2098 "during execution is \"%s\".\n"),
2103 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2105 if (!target_can_lock_scheduler
)
2107 scheduler_mode
= schedlock_off
;
2108 error (_("Target '%s' cannot support this command."), target_shortname
);
2112 /* True if execution commands resume all threads of all processes by
2113 default; otherwise, resume only threads of the current inferior
2115 bool sched_multi
= false;
2117 /* Try to setup for software single stepping over the specified location.
2118 Return 1 if target_resume() should use hardware single step.
2120 GDBARCH the current gdbarch.
2121 PC the location to step over. */
2124 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2128 if (execution_direction
== EXEC_FORWARD
2129 && gdbarch_software_single_step_p (gdbarch
))
2130 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2138 user_visible_resume_ptid (int step
)
2144 /* With non-stop mode on, threads are always handled
2146 resume_ptid
= inferior_ptid
;
2148 else if ((scheduler_mode
== schedlock_on
)
2149 || (scheduler_mode
== schedlock_step
&& step
))
2151 /* User-settable 'scheduler' mode requires solo thread
2153 resume_ptid
= inferior_ptid
;
2155 else if ((scheduler_mode
== schedlock_replay
)
2156 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2158 /* User-settable 'scheduler' mode requires solo thread resume in replay
2160 resume_ptid
= inferior_ptid
;
2162 else if (!sched_multi
&& target_supports_multi_process ())
2164 /* Resume all threads of the current process (and none of other
2166 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2170 /* Resume all threads of all processes. */
2171 resume_ptid
= RESUME_ALL
;
2179 process_stratum_target
*
2180 user_visible_resume_target (ptid_t resume_ptid
)
2182 return (resume_ptid
== minus_one_ptid
&& sched_multi
2184 : current_inferior ()->process_target ());
2187 /* Return a ptid representing the set of threads that we will resume,
2188 in the perspective of the target, assuming run control handling
2189 does not require leaving some threads stopped (e.g., stepping past
2190 breakpoint). USER_STEP indicates whether we're about to start the
2191 target for a stepping command. */
2194 internal_resume_ptid (int user_step
)
2196 /* In non-stop, we always control threads individually. Note that
2197 the target may always work in non-stop mode even with "set
2198 non-stop off", in which case user_visible_resume_ptid could
2199 return a wildcard ptid. */
2200 if (target_is_non_stop_p ())
2201 return inferior_ptid
;
2203 return user_visible_resume_ptid (user_step
);
2206 /* Wrapper for target_resume, that handles infrun-specific
2210 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2212 struct thread_info
*tp
= inferior_thread ();
2214 gdb_assert (!tp
->stop_requested
);
2216 /* Install inferior's terminal modes. */
2217 target_terminal::inferior ();
2219 /* Avoid confusing the next resume, if the next stop/resume
2220 happens to apply to another thread. */
2221 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2223 /* Advise target which signals may be handled silently.
2225 If we have removed breakpoints because we are stepping over one
2226 in-line (in any thread), we need to receive all signals to avoid
2227 accidentally skipping a breakpoint during execution of a signal
2230 Likewise if we're displaced stepping, otherwise a trap for a
2231 breakpoint in a signal handler might be confused with the
2232 displaced step finishing. We don't make the displaced_step_fixup
2233 step distinguish the cases instead, because:
2235 - a backtrace while stopped in the signal handler would show the
2236 scratch pad as frame older than the signal handler, instead of
2237 the real mainline code.
2239 - when the thread is later resumed, the signal handler would
2240 return to the scratch pad area, which would no longer be
2242 if (step_over_info_valid_p ()
2243 || displaced_step_in_progress (tp
->inf
))
2244 target_pass_signals ({});
2246 target_pass_signals (signal_pass
);
2248 target_resume (resume_ptid
, step
, sig
);
2250 target_commit_resume ();
2252 if (target_can_async_p ())
2256 /* Resume the inferior. SIG is the signal to give the inferior
2257 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2258 call 'resume', which handles exceptions. */
2261 resume_1 (enum gdb_signal sig
)
2263 struct regcache
*regcache
= get_current_regcache ();
2264 struct gdbarch
*gdbarch
= regcache
->arch ();
2265 struct thread_info
*tp
= inferior_thread ();
2266 const address_space
*aspace
= regcache
->aspace ();
2268 /* This represents the user's step vs continue request. When
2269 deciding whether "set scheduler-locking step" applies, it's the
2270 user's intention that counts. */
2271 const int user_step
= tp
->control
.stepping_command
;
2272 /* This represents what we'll actually request the target to do.
2273 This can decay from a step to a continue, if e.g., we need to
2274 implement single-stepping with breakpoints (software
2278 gdb_assert (!tp
->stop_requested
);
2279 gdb_assert (!thread_is_in_step_over_chain (tp
));
2281 if (tp
->suspend
.waitstatus_pending_p
)
2284 ("thread %s has pending wait "
2285 "status %s (currently_stepping=%d).",
2286 target_pid_to_str (tp
->ptid
).c_str (),
2287 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2288 currently_stepping (tp
));
2290 tp
->inf
->process_target ()->threads_executing
= true;
2293 /* FIXME: What should we do if we are supposed to resume this
2294 thread with a signal? Maybe we should maintain a queue of
2295 pending signals to deliver. */
2296 if (sig
!= GDB_SIGNAL_0
)
2298 warning (_("Couldn't deliver signal %s to %s."),
2299 gdb_signal_to_name (sig
),
2300 target_pid_to_str (tp
->ptid
).c_str ());
2303 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2305 if (target_can_async_p ())
2308 /* Tell the event loop we have an event to process. */
2309 mark_async_event_handler (infrun_async_inferior_event_token
);
2314 tp
->stepped_breakpoint
= 0;
2316 /* Depends on stepped_breakpoint. */
2317 step
= currently_stepping (tp
);
2319 if (current_inferior ()->waiting_for_vfork_done
)
2321 /* Don't try to single-step a vfork parent that is waiting for
2322 the child to get out of the shared memory region (by exec'ing
2323 or exiting). This is particularly important on software
2324 single-step archs, as the child process would trip on the
2325 software single step breakpoint inserted for the parent
2326 process. Since the parent will not actually execute any
2327 instruction until the child is out of the shared region (such
2328 are vfork's semantics), it is safe to simply continue it.
2329 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2330 the parent, and tell it to `keep_going', which automatically
2331 re-sets it stepping. */
2332 infrun_log_debug ("resume : clear step");
2336 CORE_ADDR pc
= regcache_read_pc (regcache
);
2338 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2339 "current thread [%s] at %s",
2340 step
, gdb_signal_to_symbol_string (sig
),
2341 tp
->control
.trap_expected
,
2342 target_pid_to_str (inferior_ptid
).c_str (),
2343 paddress (gdbarch
, pc
));
2345 /* Normally, by the time we reach `resume', the breakpoints are either
2346 removed or inserted, as appropriate. The exception is if we're sitting
2347 at a permanent breakpoint; we need to step over it, but permanent
2348 breakpoints can't be removed. So we have to test for it here. */
2349 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2351 if (sig
!= GDB_SIGNAL_0
)
2353 /* We have a signal to pass to the inferior. The resume
2354 may, or may not take us to the signal handler. If this
2355 is a step, we'll need to stop in the signal handler, if
2356 there's one, (if the target supports stepping into
2357 handlers), or in the next mainline instruction, if
2358 there's no handler. If this is a continue, we need to be
2359 sure to run the handler with all breakpoints inserted.
2360 In all cases, set a breakpoint at the current address
2361 (where the handler returns to), and once that breakpoint
2362 is hit, resume skipping the permanent breakpoint. If
2363 that breakpoint isn't hit, then we've stepped into the
2364 signal handler (or hit some other event). We'll delete
2365 the step-resume breakpoint then. */
2367 infrun_log_debug ("resume: skipping permanent breakpoint, "
2368 "deliver signal first");
2370 clear_step_over_info ();
2371 tp
->control
.trap_expected
= 0;
2373 if (tp
->control
.step_resume_breakpoint
== NULL
)
2375 /* Set a "high-priority" step-resume, as we don't want
2376 user breakpoints at PC to trigger (again) when this
2378 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2379 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2381 tp
->step_after_step_resume_breakpoint
= step
;
2384 insert_breakpoints ();
2388 /* There's no signal to pass, we can go ahead and skip the
2389 permanent breakpoint manually. */
2390 infrun_log_debug ("skipping permanent breakpoint");
2391 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2392 /* Update pc to reflect the new address from which we will
2393 execute instructions. */
2394 pc
= regcache_read_pc (regcache
);
2398 /* We've already advanced the PC, so the stepping part
2399 is done. Now we need to arrange for a trap to be
2400 reported to handle_inferior_event. Set a breakpoint
2401 at the current PC, and run to it. Don't update
2402 prev_pc, because if we end in
2403 switch_back_to_stepped_thread, we want the "expected
2404 thread advanced also" branch to be taken. IOW, we
2405 don't want this thread to step further from PC
2407 gdb_assert (!step_over_info_valid_p ());
2408 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2409 insert_breakpoints ();
2411 resume_ptid
= internal_resume_ptid (user_step
);
2412 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2419 /* If we have a breakpoint to step over, make sure to do a single
2420 step only. Same if we have software watchpoints. */
2421 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2422 tp
->control
.may_range_step
= 0;
2424 /* If displaced stepping is enabled, step over breakpoints by executing a
2425 copy of the instruction at a different address.
2427 We can't use displaced stepping when we have a signal to deliver;
2428 the comments for displaced_step_prepare explain why. The
2429 comments in the handle_inferior event for dealing with 'random
2430 signals' explain what we do instead.
2432 We can't use displaced stepping when we are waiting for vfork_done
2433 event, displaced stepping breaks the vfork child similarly as single
2434 step software breakpoint. */
2435 if (tp
->control
.trap_expected
2436 && use_displaced_stepping (tp
)
2437 && !step_over_info_valid_p ()
2438 && sig
== GDB_SIGNAL_0
2439 && !current_inferior ()->waiting_for_vfork_done
)
2441 int prepared
= displaced_step_prepare (tp
);
2445 infrun_log_debug ("Got placed in step-over queue");
2447 tp
->control
.trap_expected
= 0;
2450 else if (prepared
< 0)
2452 /* Fallback to stepping over the breakpoint in-line. */
2454 if (target_is_non_stop_p ())
2455 stop_all_threads ();
2457 set_step_over_info (regcache
->aspace (),
2458 regcache_read_pc (regcache
), 0, tp
->global_num
);
2460 step
= maybe_software_singlestep (gdbarch
, pc
);
2462 insert_breakpoints ();
2464 else if (prepared
> 0)
2466 struct displaced_step_inferior_state
*displaced
;
2468 /* Update pc to reflect the new address from which we will
2469 execute instructions due to displaced stepping. */
2470 pc
= regcache_read_pc (get_thread_regcache (tp
));
2472 displaced
= get_displaced_stepping_state (tp
->inf
);
2473 step
= gdbarch_displaced_step_hw_singlestep
2474 (gdbarch
, displaced
->step_closure
.get ());
2478 /* Do we need to do it the hard way, w/temp breakpoints? */
2480 step
= maybe_software_singlestep (gdbarch
, pc
);
2482 /* Currently, our software single-step implementation leads to different
2483 results than hardware single-stepping in one situation: when stepping
2484 into delivering a signal which has an associated signal handler,
2485 hardware single-step will stop at the first instruction of the handler,
2486 while software single-step will simply skip execution of the handler.
2488 For now, this difference in behavior is accepted since there is no
2489 easy way to actually implement single-stepping into a signal handler
2490 without kernel support.
2492 However, there is one scenario where this difference leads to follow-on
2493 problems: if we're stepping off a breakpoint by removing all breakpoints
2494 and then single-stepping. In this case, the software single-step
2495 behavior means that even if there is a *breakpoint* in the signal
2496 handler, GDB still would not stop.
2498 Fortunately, we can at least fix this particular issue. We detect
2499 here the case where we are about to deliver a signal while software
2500 single-stepping with breakpoints removed. In this situation, we
2501 revert the decisions to remove all breakpoints and insert single-
2502 step breakpoints, and instead we install a step-resume breakpoint
2503 at the current address, deliver the signal without stepping, and
2504 once we arrive back at the step-resume breakpoint, actually step
2505 over the breakpoint we originally wanted to step over. */
2506 if (thread_has_single_step_breakpoints_set (tp
)
2507 && sig
!= GDB_SIGNAL_0
2508 && step_over_info_valid_p ())
2510 /* If we have nested signals or a pending signal is delivered
2511 immediately after a handler returns, might already have
2512 a step-resume breakpoint set on the earlier handler. We cannot
2513 set another step-resume breakpoint; just continue on until the
2514 original breakpoint is hit. */
2515 if (tp
->control
.step_resume_breakpoint
== NULL
)
2517 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2518 tp
->step_after_step_resume_breakpoint
= 1;
2521 delete_single_step_breakpoints (tp
);
2523 clear_step_over_info ();
2524 tp
->control
.trap_expected
= 0;
2526 insert_breakpoints ();
2529 /* If STEP is set, it's a request to use hardware stepping
2530 facilities. But in that case, we should never
2531 use singlestep breakpoint. */
2532 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2534 /* Decide the set of threads to ask the target to resume. */
2535 if (tp
->control
.trap_expected
)
2537 /* We're allowing a thread to run past a breakpoint it has
2538 hit, either by single-stepping the thread with the breakpoint
2539 removed, or by displaced stepping, with the breakpoint inserted.
2540 In the former case, we need to single-step only this thread,
2541 and keep others stopped, as they can miss this breakpoint if
2542 allowed to run. That's not really a problem for displaced
2543 stepping, but, we still keep other threads stopped, in case
2544 another thread is also stopped for a breakpoint waiting for
2545 its turn in the displaced stepping queue. */
2546 resume_ptid
= inferior_ptid
;
2549 resume_ptid
= internal_resume_ptid (user_step
);
2551 if (execution_direction
!= EXEC_REVERSE
2552 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2554 /* There are two cases where we currently need to step a
2555 breakpoint instruction when we have a signal to deliver:
2557 - See handle_signal_stop where we handle random signals that
2558 could take out us out of the stepping range. Normally, in
2559 that case we end up continuing (instead of stepping) over the
2560 signal handler with a breakpoint at PC, but there are cases
2561 where we should _always_ single-step, even if we have a
2562 step-resume breakpoint, like when a software watchpoint is
2563 set. Assuming single-stepping and delivering a signal at the
2564 same time would takes us to the signal handler, then we could
2565 have removed the breakpoint at PC to step over it. However,
2566 some hardware step targets (like e.g., Mac OS) can't step
2567 into signal handlers, and for those, we need to leave the
2568 breakpoint at PC inserted, as otherwise if the handler
2569 recurses and executes PC again, it'll miss the breakpoint.
2570 So we leave the breakpoint inserted anyway, but we need to
2571 record that we tried to step a breakpoint instruction, so
2572 that adjust_pc_after_break doesn't end up confused.
2574 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2575 in one thread after another thread that was stepping had been
2576 momentarily paused for a step-over. When we re-resume the
2577 stepping thread, it may be resumed from that address with a
2578 breakpoint that hasn't trapped yet. Seen with
2579 gdb.threads/non-stop-fair-events.exp, on targets that don't
2580 do displaced stepping. */
2582 infrun_log_debug ("resume: [%s] stepped breakpoint",
2583 target_pid_to_str (tp
->ptid
).c_str ());
2585 tp
->stepped_breakpoint
= 1;
2587 /* Most targets can step a breakpoint instruction, thus
2588 executing it normally. But if this one cannot, just
2589 continue and we will hit it anyway. */
2590 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2595 && tp
->control
.trap_expected
2596 && use_displaced_stepping (tp
)
2597 && !step_over_info_valid_p ())
2599 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2600 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2601 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2604 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2605 paddress (resume_gdbarch
, actual_pc
));
2606 read_memory (actual_pc
, buf
, sizeof (buf
));
2607 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2610 if (tp
->control
.may_range_step
)
2612 /* If we're resuming a thread with the PC out of the step
2613 range, then we're doing some nested/finer run control
2614 operation, like stepping the thread out of the dynamic
2615 linker or the displaced stepping scratch pad. We
2616 shouldn't have allowed a range step then. */
2617 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2620 do_target_resume (resume_ptid
, step
, sig
);
2624 /* Resume the inferior. SIG is the signal to give the inferior
2625 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2626 rolls back state on error. */
2629 resume (gdb_signal sig
)
2635 catch (const gdb_exception
&ex
)
2637 /* If resuming is being aborted for any reason, delete any
2638 single-step breakpoint resume_1 may have created, to avoid
2639 confusing the following resumption, and to avoid leaving
2640 single-step breakpoints perturbing other threads, in case
2641 we're running in non-stop mode. */
2642 if (inferior_ptid
!= null_ptid
)
2643 delete_single_step_breakpoints (inferior_thread ());
2653 /* Counter that tracks number of user visible stops. This can be used
2654 to tell whether a command has proceeded the inferior past the
2655 current location. This allows e.g., inferior function calls in
2656 breakpoint commands to not interrupt the command list. When the
2657 call finishes successfully, the inferior is standing at the same
2658 breakpoint as if nothing happened (and so we don't call
2660 static ULONGEST current_stop_id
;
2667 return current_stop_id
;
2670 /* Called when we report a user visible stop. */
2678 /* Clear out all variables saying what to do when inferior is continued.
2679 First do this, then set the ones you want, then call `proceed'. */
2682 clear_proceed_status_thread (struct thread_info
*tp
)
2684 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2686 /* If we're starting a new sequence, then the previous finished
2687 single-step is no longer relevant. */
2688 if (tp
->suspend
.waitstatus_pending_p
)
2690 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2692 infrun_log_debug ("pending event of %s was a finished step. "
2694 target_pid_to_str (tp
->ptid
).c_str ());
2696 tp
->suspend
.waitstatus_pending_p
= 0;
2697 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2702 ("thread %s has pending wait status %s (currently_stepping=%d).",
2703 target_pid_to_str (tp
->ptid
).c_str (),
2704 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2705 currently_stepping (tp
));
2709 /* If this signal should not be seen by program, give it zero.
2710 Used for debugging signals. */
2711 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2712 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2714 delete tp
->thread_fsm
;
2715 tp
->thread_fsm
= NULL
;
2717 tp
->control
.trap_expected
= 0;
2718 tp
->control
.step_range_start
= 0;
2719 tp
->control
.step_range_end
= 0;
2720 tp
->control
.may_range_step
= 0;
2721 tp
->control
.step_frame_id
= null_frame_id
;
2722 tp
->control
.step_stack_frame_id
= null_frame_id
;
2723 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2724 tp
->control
.step_start_function
= NULL
;
2725 tp
->stop_requested
= 0;
2727 tp
->control
.stop_step
= 0;
2729 tp
->control
.proceed_to_finish
= 0;
2731 tp
->control
.stepping_command
= 0;
2733 /* Discard any remaining commands or status from previous stop. */
2734 bpstat_clear (&tp
->control
.stop_bpstat
);
2738 clear_proceed_status (int step
)
2740 /* With scheduler-locking replay, stop replaying other threads if we're
2741 not replaying the user-visible resume ptid.
2743 This is a convenience feature to not require the user to explicitly
2744 stop replaying the other threads. We're assuming that the user's
2745 intent is to resume tracing the recorded process. */
2746 if (!non_stop
&& scheduler_mode
== schedlock_replay
2747 && target_record_is_replaying (minus_one_ptid
)
2748 && !target_record_will_replay (user_visible_resume_ptid (step
),
2749 execution_direction
))
2750 target_record_stop_replaying ();
2752 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2754 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2755 process_stratum_target
*resume_target
2756 = user_visible_resume_target (resume_ptid
);
2758 /* In all-stop mode, delete the per-thread status of all threads
2759 we're about to resume, implicitly and explicitly. */
2760 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2761 clear_proceed_status_thread (tp
);
2764 if (inferior_ptid
!= null_ptid
)
2766 struct inferior
*inferior
;
2770 /* If in non-stop mode, only delete the per-thread status of
2771 the current thread. */
2772 clear_proceed_status_thread (inferior_thread ());
2775 inferior
= current_inferior ();
2776 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2779 gdb::observers::about_to_proceed
.notify ();
2782 /* Returns true if TP is still stopped at a breakpoint that needs
2783 stepping-over in order to make progress. If the breakpoint is gone
2784 meanwhile, we can skip the whole step-over dance. */
2787 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2789 if (tp
->stepping_over_breakpoint
)
2791 struct regcache
*regcache
= get_thread_regcache (tp
);
2793 if (breakpoint_here_p (regcache
->aspace (),
2794 regcache_read_pc (regcache
))
2795 == ordinary_breakpoint_here
)
2798 tp
->stepping_over_breakpoint
= 0;
2804 /* Check whether thread TP still needs to start a step-over in order
2805 to make progress when resumed. Returns an bitwise or of enum
2806 step_over_what bits, indicating what needs to be stepped over. */
2808 static step_over_what
2809 thread_still_needs_step_over (struct thread_info
*tp
)
2811 step_over_what what
= 0;
2813 if (thread_still_needs_step_over_bp (tp
))
2814 what
|= STEP_OVER_BREAKPOINT
;
2816 if (tp
->stepping_over_watchpoint
2817 && !target_have_steppable_watchpoint
)
2818 what
|= STEP_OVER_WATCHPOINT
;
2823 /* Returns true if scheduler locking applies. STEP indicates whether
2824 we're about to do a step/next-like command to a thread. */
2827 schedlock_applies (struct thread_info
*tp
)
2829 return (scheduler_mode
== schedlock_on
2830 || (scheduler_mode
== schedlock_step
2831 && tp
->control
.stepping_command
)
2832 || (scheduler_mode
== schedlock_replay
2833 && target_record_will_replay (minus_one_ptid
,
2834 execution_direction
)));
2837 /* Calls target_commit_resume on all targets. */
2840 commit_resume_all_targets ()
2842 scoped_restore_current_thread restore_thread
;
2844 /* Map between process_target and a representative inferior. This
2845 is to avoid committing a resume in the same target more than
2846 once. Resumptions must be idempotent, so this is an
2848 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2850 for (inferior
*inf
: all_non_exited_inferiors ())
2851 if (inf
->has_execution ())
2852 conn_inf
[inf
->process_target ()] = inf
;
2854 for (const auto &ci
: conn_inf
)
2856 inferior
*inf
= ci
.second
;
2857 switch_to_inferior_no_thread (inf
);
2858 target_commit_resume ();
2862 /* Check that all the targets we're about to resume are in non-stop
2863 mode. Ideally, we'd only care whether all targets support
2864 target-async, but we're not there yet. E.g., stop_all_threads
2865 doesn't know how to handle all-stop targets. Also, the remote
2866 protocol in all-stop mode is synchronous, irrespective of
2867 target-async, which means that things like a breakpoint re-set
2868 triggered by one target would try to read memory from all targets
2872 check_multi_target_resumption (process_stratum_target
*resume_target
)
2874 if (!non_stop
&& resume_target
== nullptr)
2876 scoped_restore_current_thread restore_thread
;
2878 /* This is used to track whether we're resuming more than one
2880 process_stratum_target
*first_connection
= nullptr;
2882 /* The first inferior we see with a target that does not work in
2883 always-non-stop mode. */
2884 inferior
*first_not_non_stop
= nullptr;
2886 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2888 switch_to_inferior_no_thread (inf
);
2890 if (!target_has_execution
)
2893 process_stratum_target
*proc_target
2894 = current_inferior ()->process_target();
2896 if (!target_is_non_stop_p ())
2897 first_not_non_stop
= inf
;
2899 if (first_connection
== nullptr)
2900 first_connection
= proc_target
;
2901 else if (first_connection
!= proc_target
2902 && first_not_non_stop
!= nullptr)
2904 switch_to_inferior_no_thread (first_not_non_stop
);
2906 proc_target
= current_inferior ()->process_target();
2908 error (_("Connection %d (%s) does not support "
2909 "multi-target resumption."),
2910 proc_target
->connection_number
,
2911 make_target_connection_string (proc_target
).c_str ());
2917 /* Basic routine for continuing the program in various fashions.
2919 ADDR is the address to resume at, or -1 for resume where stopped.
2920 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2921 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2923 You should call clear_proceed_status before calling proceed. */
2926 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2928 struct regcache
*regcache
;
2929 struct gdbarch
*gdbarch
;
2931 struct execution_control_state ecss
;
2932 struct execution_control_state
*ecs
= &ecss
;
2935 /* If we're stopped at a fork/vfork, follow the branch set by the
2936 "set follow-fork-mode" command; otherwise, we'll just proceed
2937 resuming the current thread. */
2938 if (!follow_fork ())
2940 /* The target for some reason decided not to resume. */
2942 if (target_can_async_p ())
2943 inferior_event_handler (INF_EXEC_COMPLETE
);
2947 /* We'll update this if & when we switch to a new thread. */
2948 previous_inferior_ptid
= inferior_ptid
;
2950 regcache
= get_current_regcache ();
2951 gdbarch
= regcache
->arch ();
2952 const address_space
*aspace
= regcache
->aspace ();
2954 pc
= regcache_read_pc_protected (regcache
);
2956 thread_info
*cur_thr
= inferior_thread ();
2958 /* Fill in with reasonable starting values. */
2959 init_thread_stepping_state (cur_thr
);
2961 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2964 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2965 process_stratum_target
*resume_target
2966 = user_visible_resume_target (resume_ptid
);
2968 check_multi_target_resumption (resume_target
);
2970 if (addr
== (CORE_ADDR
) -1)
2972 if (pc
== cur_thr
->suspend
.stop_pc
2973 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2974 && execution_direction
!= EXEC_REVERSE
)
2975 /* There is a breakpoint at the address we will resume at,
2976 step one instruction before inserting breakpoints so that
2977 we do not stop right away (and report a second hit at this
2980 Note, we don't do this in reverse, because we won't
2981 actually be executing the breakpoint insn anyway.
2982 We'll be (un-)executing the previous instruction. */
2983 cur_thr
->stepping_over_breakpoint
= 1;
2984 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2985 && gdbarch_single_step_through_delay (gdbarch
,
2986 get_current_frame ()))
2987 /* We stepped onto an instruction that needs to be stepped
2988 again before re-inserting the breakpoint, do so. */
2989 cur_thr
->stepping_over_breakpoint
= 1;
2993 regcache_write_pc (regcache
, addr
);
2996 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2997 cur_thr
->suspend
.stop_signal
= siggnal
;
2999 /* If an exception is thrown from this point on, make sure to
3000 propagate GDB's knowledge of the executing state to the
3001 frontend/user running state. */
3002 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3004 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3005 threads (e.g., we might need to set threads stepping over
3006 breakpoints first), from the user/frontend's point of view, all
3007 threads in RESUME_PTID are now running. Unless we're calling an
3008 inferior function, as in that case we pretend the inferior
3009 doesn't run at all. */
3010 if (!cur_thr
->control
.in_infcall
)
3011 set_running (resume_target
, resume_ptid
, true);
3013 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3014 gdb_signal_to_symbol_string (siggnal
));
3016 annotate_starting ();
3018 /* Make sure that output from GDB appears before output from the
3020 gdb_flush (gdb_stdout
);
3022 /* Since we've marked the inferior running, give it the terminal. A
3023 QUIT/Ctrl-C from here on is forwarded to the target (which can
3024 still detect attempts to unblock a stuck connection with repeated
3025 Ctrl-C from within target_pass_ctrlc). */
3026 target_terminal::inferior ();
3028 /* In a multi-threaded task we may select another thread and
3029 then continue or step.
3031 But if a thread that we're resuming had stopped at a breakpoint,
3032 it will immediately cause another breakpoint stop without any
3033 execution (i.e. it will report a breakpoint hit incorrectly). So
3034 we must step over it first.
3036 Look for threads other than the current (TP) that reported a
3037 breakpoint hit and haven't been resumed yet since. */
3039 /* If scheduler locking applies, we can avoid iterating over all
3041 if (!non_stop
&& !schedlock_applies (cur_thr
))
3043 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3046 switch_to_thread_no_regs (tp
);
3048 /* Ignore the current thread here. It's handled
3053 if (!thread_still_needs_step_over (tp
))
3056 gdb_assert (!thread_is_in_step_over_chain (tp
));
3058 infrun_log_debug ("need to step-over [%s] first",
3059 target_pid_to_str (tp
->ptid
).c_str ());
3061 global_thread_step_over_chain_enqueue (tp
);
3064 switch_to_thread (cur_thr
);
3067 /* Enqueue the current thread last, so that we move all other
3068 threads over their breakpoints first. */
3069 if (cur_thr
->stepping_over_breakpoint
)
3070 global_thread_step_over_chain_enqueue (cur_thr
);
3072 /* If the thread isn't started, we'll still need to set its prev_pc,
3073 so that switch_back_to_stepped_thread knows the thread hasn't
3074 advanced. Must do this before resuming any thread, as in
3075 all-stop/remote, once we resume we can't send any other packet
3076 until the target stops again. */
3077 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3080 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3082 started
= start_step_over ();
3084 if (step_over_info_valid_p ())
3086 /* Either this thread started a new in-line step over, or some
3087 other thread was already doing one. In either case, don't
3088 resume anything else until the step-over is finished. */
3090 else if (started
&& !target_is_non_stop_p ())
3092 /* A new displaced stepping sequence was started. In all-stop,
3093 we can't talk to the target anymore until it next stops. */
3095 else if (!non_stop
&& target_is_non_stop_p ())
3097 /* In all-stop, but the target is always in non-stop mode.
3098 Start all other threads that are implicitly resumed too. */
3099 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3102 switch_to_thread_no_regs (tp
);
3104 if (!tp
->inf
->has_execution ())
3106 infrun_log_debug ("[%s] target has no execution",
3107 target_pid_to_str (tp
->ptid
).c_str ());
3113 infrun_log_debug ("[%s] resumed",
3114 target_pid_to_str (tp
->ptid
).c_str ());
3115 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3119 if (thread_is_in_step_over_chain (tp
))
3121 infrun_log_debug ("[%s] needs step-over",
3122 target_pid_to_str (tp
->ptid
).c_str ());
3126 infrun_log_debug ("resuming %s",
3127 target_pid_to_str (tp
->ptid
).c_str ());
3129 reset_ecs (ecs
, tp
);
3130 switch_to_thread (tp
);
3131 keep_going_pass_signal (ecs
);
3132 if (!ecs
->wait_some_more
)
3133 error (_("Command aborted."));
3136 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3138 /* The thread wasn't started, and isn't queued, run it now. */
3139 reset_ecs (ecs
, cur_thr
);
3140 switch_to_thread (cur_thr
);
3141 keep_going_pass_signal (ecs
);
3142 if (!ecs
->wait_some_more
)
3143 error (_("Command aborted."));
3147 commit_resume_all_targets ();
3149 finish_state
.release ();
3151 /* If we've switched threads above, switch back to the previously
3152 current thread. We don't want the user to see a different
3154 switch_to_thread (cur_thr
);
3156 /* Tell the event loop to wait for it to stop. If the target
3157 supports asynchronous execution, it'll do this from within
3159 if (!target_can_async_p ())
3160 mark_async_event_handler (infrun_async_inferior_event_token
);
3164 /* Start remote-debugging of a machine over a serial link. */
3167 start_remote (int from_tty
)
3169 inferior
*inf
= current_inferior ();
3170 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3172 /* Always go on waiting for the target, regardless of the mode. */
3173 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3174 indicate to wait_for_inferior that a target should timeout if
3175 nothing is returned (instead of just blocking). Because of this,
3176 targets expecting an immediate response need to, internally, set
3177 things up so that the target_wait() is forced to eventually
3179 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3180 differentiate to its caller what the state of the target is after
3181 the initial open has been performed. Here we're assuming that
3182 the target has stopped. It should be possible to eventually have
3183 target_open() return to the caller an indication that the target
3184 is currently running and GDB state should be set to the same as
3185 for an async run. */
3186 wait_for_inferior (inf
);
3188 /* Now that the inferior has stopped, do any bookkeeping like
3189 loading shared libraries. We want to do this before normal_stop,
3190 so that the displayed frame is up to date. */
3191 post_create_inferior (current_top_target (), from_tty
);
3196 /* Initialize static vars when a new inferior begins. */
3199 init_wait_for_inferior (void)
3201 /* These are meaningless until the first time through wait_for_inferior. */
3203 breakpoint_init_inferior (inf_starting
);
3205 clear_proceed_status (0);
3207 nullify_last_target_wait_ptid ();
3209 previous_inferior_ptid
= inferior_ptid
;
3214 static void handle_inferior_event (struct execution_control_state
*ecs
);
3216 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3217 struct execution_control_state
*ecs
);
3218 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3219 struct execution_control_state
*ecs
);
3220 static void handle_signal_stop (struct execution_control_state
*ecs
);
3221 static void check_exception_resume (struct execution_control_state
*,
3222 struct frame_info
*);
3224 static void end_stepping_range (struct execution_control_state
*ecs
);
3225 static void stop_waiting (struct execution_control_state
*ecs
);
3226 static void keep_going (struct execution_control_state
*ecs
);
3227 static void process_event_stop_test (struct execution_control_state
*ecs
);
3228 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3230 /* This function is attached as a "thread_stop_requested" observer.
3231 Cleanup local state that assumed the PTID was to be resumed, and
3232 report the stop to the frontend. */
3235 infrun_thread_stop_requested (ptid_t ptid
)
3237 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3239 /* PTID was requested to stop. If the thread was already stopped,
3240 but the user/frontend doesn't know about that yet (e.g., the
3241 thread had been temporarily paused for some step-over), set up
3242 for reporting the stop now. */
3243 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3245 if (tp
->state
!= THREAD_RUNNING
)
3250 /* Remove matching threads from the step-over queue, so
3251 start_step_over doesn't try to resume them
3253 if (thread_is_in_step_over_chain (tp
))
3254 global_thread_step_over_chain_remove (tp
);
3256 /* If the thread is stopped, but the user/frontend doesn't
3257 know about that yet, queue a pending event, as if the
3258 thread had just stopped now. Unless the thread already had
3260 if (!tp
->suspend
.waitstatus_pending_p
)
3262 tp
->suspend
.waitstatus_pending_p
= 1;
3263 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3264 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3267 /* Clear the inline-frame state, since we're re-processing the
3269 clear_inline_frame_state (tp
);
3271 /* If this thread was paused because some other thread was
3272 doing an inline-step over, let that finish first. Once
3273 that happens, we'll restart all threads and consume pending
3274 stop events then. */
3275 if (step_over_info_valid_p ())
3278 /* Otherwise we can process the (new) pending event now. Set
3279 it so this pending event is considered by
3286 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3288 if (target_last_proc_target
== tp
->inf
->process_target ()
3289 && target_last_wait_ptid
== tp
->ptid
)
3290 nullify_last_target_wait_ptid ();
3293 /* Delete the step resume, single-step and longjmp/exception resume
3294 breakpoints of TP. */
3297 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3299 delete_step_resume_breakpoint (tp
);
3300 delete_exception_resume_breakpoint (tp
);
3301 delete_single_step_breakpoints (tp
);
3304 /* If the target still has execution, call FUNC for each thread that
3305 just stopped. In all-stop, that's all the non-exited threads; in
3306 non-stop, that's the current thread, only. */
3308 typedef void (*for_each_just_stopped_thread_callback_func
)
3309 (struct thread_info
*tp
);
3312 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3314 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3317 if (target_is_non_stop_p ())
3319 /* If in non-stop mode, only the current thread stopped. */
3320 func (inferior_thread ());
3324 /* In all-stop mode, all threads have stopped. */
3325 for (thread_info
*tp
: all_non_exited_threads ())
3330 /* Delete the step resume and longjmp/exception resume breakpoints of
3331 the threads that just stopped. */
3334 delete_just_stopped_threads_infrun_breakpoints (void)
3336 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3339 /* Delete the single-step breakpoints of the threads that just
3343 delete_just_stopped_threads_single_step_breakpoints (void)
3345 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3351 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3352 const struct target_waitstatus
*ws
)
3354 std::string status_string
= target_waitstatus_to_string (ws
);
3357 /* The text is split over several lines because it was getting too long.
3358 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3359 output as a unit; we want only one timestamp printed if debug_timestamp
3362 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3365 waiton_ptid
.tid ());
3366 if (waiton_ptid
.pid () != -1)
3367 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3368 stb
.printf (", status) =\n");
3369 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3373 target_pid_to_str (result_ptid
).c_str ());
3374 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3376 /* This uses %s in part to handle %'s in the text, but also to avoid
3377 a gcc error: the format attribute requires a string literal. */
3378 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3381 /* Select a thread at random, out of those which are resumed and have
3384 static struct thread_info
*
3385 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3389 auto has_event
= [&] (thread_info
*tp
)
3391 return (tp
->ptid
.matches (waiton_ptid
)
3393 && tp
->suspend
.waitstatus_pending_p
);
3396 /* First see how many events we have. Count only resumed threads
3397 that have an event pending. */
3398 for (thread_info
*tp
: inf
->non_exited_threads ())
3402 if (num_events
== 0)
3405 /* Now randomly pick a thread out of those that have had events. */
3406 int random_selector
= (int) ((num_events
* (double) rand ())
3407 / (RAND_MAX
+ 1.0));
3410 infrun_log_debug ("Found %d events, selecting #%d",
3411 num_events
, random_selector
);
3413 /* Select the Nth thread that has had an event. */
3414 for (thread_info
*tp
: inf
->non_exited_threads ())
3416 if (random_selector
-- == 0)
3419 gdb_assert_not_reached ("event thread not found");
3422 /* Wrapper for target_wait that first checks whether threads have
3423 pending statuses to report before actually asking the target for
3424 more events. INF is the inferior we're using to call target_wait
3428 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3429 target_waitstatus
*status
, int options
)
3432 struct thread_info
*tp
;
3434 /* We know that we are looking for an event in the target of inferior
3435 INF, but we don't know which thread the event might come from. As
3436 such we want to make sure that INFERIOR_PTID is reset so that none of
3437 the wait code relies on it - doing so is always a mistake. */
3438 switch_to_inferior_no_thread (inf
);
3440 /* First check if there is a resumed thread with a wait status
3442 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3444 tp
= random_pending_event_thread (inf
, ptid
);
3448 infrun_log_debug ("Waiting for specific thread %s.",
3449 target_pid_to_str (ptid
).c_str ());
3451 /* We have a specific thread to check. */
3452 tp
= find_thread_ptid (inf
, ptid
);
3453 gdb_assert (tp
!= NULL
);
3454 if (!tp
->suspend
.waitstatus_pending_p
)
3459 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3460 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3462 struct regcache
*regcache
= get_thread_regcache (tp
);
3463 struct gdbarch
*gdbarch
= regcache
->arch ();
3467 pc
= regcache_read_pc (regcache
);
3469 if (pc
!= tp
->suspend
.stop_pc
)
3471 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3472 target_pid_to_str (tp
->ptid
).c_str (),
3473 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3474 paddress (gdbarch
, pc
));
3477 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3479 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3480 target_pid_to_str (tp
->ptid
).c_str (),
3481 paddress (gdbarch
, pc
));
3488 infrun_log_debug ("pending event of %s cancelled.",
3489 target_pid_to_str (tp
->ptid
).c_str ());
3491 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3492 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3498 infrun_log_debug ("Using pending wait status %s for %s.",
3499 target_waitstatus_to_string
3500 (&tp
->suspend
.waitstatus
).c_str (),
3501 target_pid_to_str (tp
->ptid
).c_str ());
3503 /* Now that we've selected our final event LWP, un-adjust its PC
3504 if it was a software breakpoint (and the target doesn't
3505 always adjust the PC itself). */
3506 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3507 && !target_supports_stopped_by_sw_breakpoint ())
3509 struct regcache
*regcache
;
3510 struct gdbarch
*gdbarch
;
3513 regcache
= get_thread_regcache (tp
);
3514 gdbarch
= regcache
->arch ();
3516 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3521 pc
= regcache_read_pc (regcache
);
3522 regcache_write_pc (regcache
, pc
+ decr_pc
);
3526 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3527 *status
= tp
->suspend
.waitstatus
;
3528 tp
->suspend
.waitstatus_pending_p
= 0;
3530 /* Wake up the event loop again, until all pending events are
3532 if (target_is_async_p ())
3533 mark_async_event_handler (infrun_async_inferior_event_token
);
3537 /* But if we don't find one, we'll have to wait. */
3539 if (deprecated_target_wait_hook
)
3540 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3542 event_ptid
= target_wait (ptid
, status
, options
);
3547 /* Wrapper for target_wait that first checks whether threads have
3548 pending statuses to report before actually asking the target for
3549 more events. Polls for events from all inferiors/targets. */
3552 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3554 int num_inferiors
= 0;
3555 int random_selector
;
3557 /* For fairness, we pick the first inferior/target to poll at random
3558 out of all inferiors that may report events, and then continue
3559 polling the rest of the inferior list starting from that one in a
3560 circular fashion until the whole list is polled once. */
3562 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3564 return (inf
->process_target () != NULL
3565 && ptid_t (inf
->pid
).matches (wait_ptid
));
3568 /* First see how many matching inferiors we have. */
3569 for (inferior
*inf
: all_inferiors ())
3570 if (inferior_matches (inf
))
3573 if (num_inferiors
== 0)
3575 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3579 /* Now randomly pick an inferior out of those that matched. */
3580 random_selector
= (int)
3581 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3583 if (num_inferiors
> 1)
3584 infrun_log_debug ("Found %d inferiors, starting at #%d",
3585 num_inferiors
, random_selector
);
3587 /* Select the Nth inferior that matched. */
3589 inferior
*selected
= nullptr;
3591 for (inferior
*inf
: all_inferiors ())
3592 if (inferior_matches (inf
))
3593 if (random_selector
-- == 0)
3599 /* Now poll for events out of each of the matching inferior's
3600 targets, starting from the selected one. */
3602 auto do_wait
= [&] (inferior
*inf
)
3604 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3605 ecs
->target
= inf
->process_target ();
3606 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3609 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3610 here spuriously after the target is all stopped and we've already
3611 reported the stop to the user, polling for events. */
3612 scoped_restore_current_thread restore_thread
;
3614 int inf_num
= selected
->num
;
3615 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3616 if (inferior_matches (inf
))
3620 for (inferior
*inf
= inferior_list
;
3621 inf
!= NULL
&& inf
->num
< inf_num
;
3623 if (inferior_matches (inf
))
3627 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3631 /* Prepare and stabilize the inferior for detaching it. E.g.,
3632 detaching while a thread is displaced stepping is a recipe for
3633 crashing it, as nothing would readjust the PC out of the scratch
3637 prepare_for_detach (void)
3639 struct inferior
*inf
= current_inferior ();
3640 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3642 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3644 /* Is any thread of this process displaced stepping? If not,
3645 there's nothing else to do. */
3646 if (displaced
->step_thread
== nullptr)
3649 infrun_log_debug ("displaced-stepping in-process while detaching");
3651 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3653 while (displaced
->step_thread
!= nullptr)
3655 struct execution_control_state ecss
;
3656 struct execution_control_state
*ecs
;
3659 memset (ecs
, 0, sizeof (*ecs
));
3661 overlay_cache_invalid
= 1;
3662 /* Flush target cache before starting to handle each event.
3663 Target was running and cache could be stale. This is just a
3664 heuristic. Running threads may modify target memory, but we
3665 don't get any event. */
3666 target_dcache_invalidate ();
3668 do_target_wait (pid_ptid
, ecs
, 0);
3671 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3673 /* If an error happens while handling the event, propagate GDB's
3674 knowledge of the executing state to the frontend/user running
3676 scoped_finish_thread_state
finish_state (inf
->process_target (),
3679 /* Now figure out what to do with the result of the result. */
3680 handle_inferior_event (ecs
);
3682 /* No error, don't finish the state yet. */
3683 finish_state
.release ();
3685 /* Breakpoints and watchpoints are not installed on the target
3686 at this point, and signals are passed directly to the
3687 inferior, so this must mean the process is gone. */
3688 if (!ecs
->wait_some_more
)
3690 restore_detaching
.release ();
3691 error (_("Program exited while detaching"));
3695 restore_detaching
.release ();
3698 /* Wait for control to return from inferior to debugger.
3700 If inferior gets a signal, we may decide to start it up again
3701 instead of returning. That is why there is a loop in this function.
3702 When this function actually returns it means the inferior
3703 should be left stopped and GDB should read more commands. */
3706 wait_for_inferior (inferior
*inf
)
3708 infrun_log_debug ("wait_for_inferior ()");
3710 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3712 /* If an error happens while handling the event, propagate GDB's
3713 knowledge of the executing state to the frontend/user running
3715 scoped_finish_thread_state finish_state
3716 (inf
->process_target (), minus_one_ptid
);
3720 struct execution_control_state ecss
;
3721 struct execution_control_state
*ecs
= &ecss
;
3723 memset (ecs
, 0, sizeof (*ecs
));
3725 overlay_cache_invalid
= 1;
3727 /* Flush target cache before starting to handle each event.
3728 Target was running and cache could be stale. This is just a
3729 heuristic. Running threads may modify target memory, but we
3730 don't get any event. */
3731 target_dcache_invalidate ();
3733 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3734 ecs
->target
= inf
->process_target ();
3737 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3739 /* Now figure out what to do with the result of the result. */
3740 handle_inferior_event (ecs
);
3742 if (!ecs
->wait_some_more
)
3746 /* No error, don't finish the state yet. */
3747 finish_state
.release ();
3750 /* Cleanup that reinstalls the readline callback handler, if the
3751 target is running in the background. If while handling the target
3752 event something triggered a secondary prompt, like e.g., a
3753 pagination prompt, we'll have removed the callback handler (see
3754 gdb_readline_wrapper_line). Need to do this as we go back to the
3755 event loop, ready to process further input. Note this has no
3756 effect if the handler hasn't actually been removed, because calling
3757 rl_callback_handler_install resets the line buffer, thus losing
3761 reinstall_readline_callback_handler_cleanup ()
3763 struct ui
*ui
= current_ui
;
3767 /* We're not going back to the top level event loop yet. Don't
3768 install the readline callback, as it'd prep the terminal,
3769 readline-style (raw, noecho) (e.g., --batch). We'll install
3770 it the next time the prompt is displayed, when we're ready
3775 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3776 gdb_rl_callback_handler_reinstall ();
3779 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3780 that's just the event thread. In all-stop, that's all threads. */
3783 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3785 if (ecs
->event_thread
!= NULL
3786 && ecs
->event_thread
->thread_fsm
!= NULL
)
3787 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3791 for (thread_info
*thr
: all_non_exited_threads ())
3793 if (thr
->thread_fsm
== NULL
)
3795 if (thr
== ecs
->event_thread
)
3798 switch_to_thread (thr
);
3799 thr
->thread_fsm
->clean_up (thr
);
3802 if (ecs
->event_thread
!= NULL
)
3803 switch_to_thread (ecs
->event_thread
);
3807 /* Helper for all_uis_check_sync_execution_done that works on the
3811 check_curr_ui_sync_execution_done (void)
3813 struct ui
*ui
= current_ui
;
3815 if (ui
->prompt_state
== PROMPT_NEEDED
3817 && !gdb_in_secondary_prompt_p (ui
))
3819 target_terminal::ours ();
3820 gdb::observers::sync_execution_done
.notify ();
3821 ui_register_input_event_handler (ui
);
3828 all_uis_check_sync_execution_done (void)
3830 SWITCH_THRU_ALL_UIS ()
3832 check_curr_ui_sync_execution_done ();
3839 all_uis_on_sync_execution_starting (void)
3841 SWITCH_THRU_ALL_UIS ()
3843 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3844 async_disable_stdin ();
3848 /* Asynchronous version of wait_for_inferior. It is called by the
3849 event loop whenever a change of state is detected on the file
3850 descriptor corresponding to the target. It can be called more than
3851 once to complete a single execution command. In such cases we need
3852 to keep the state in a global variable ECSS. If it is the last time
3853 that this function is called for a single execution command, then
3854 report to the user that the inferior has stopped, and do the
3855 necessary cleanups. */
3858 fetch_inferior_event ()
3860 struct execution_control_state ecss
;
3861 struct execution_control_state
*ecs
= &ecss
;
3864 memset (ecs
, 0, sizeof (*ecs
));
3866 /* Events are always processed with the main UI as current UI. This
3867 way, warnings, debug output, etc. are always consistently sent to
3868 the main console. */
3869 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3871 /* End up with readline processing input, if necessary. */
3873 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3875 /* We're handling a live event, so make sure we're doing live
3876 debugging. If we're looking at traceframes while the target is
3877 running, we're going to need to get back to that mode after
3878 handling the event. */
3879 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3882 maybe_restore_traceframe
.emplace ();
3883 set_current_traceframe (-1);
3886 /* The user/frontend should not notice a thread switch due to
3887 internal events. Make sure we revert to the user selected
3888 thread and frame after handling the event and running any
3889 breakpoint commands. */
3890 scoped_restore_current_thread restore_thread
;
3892 overlay_cache_invalid
= 1;
3893 /* Flush target cache before starting to handle each event. Target
3894 was running and cache could be stale. This is just a heuristic.
3895 Running threads may modify target memory, but we don't get any
3897 target_dcache_invalidate ();
3899 scoped_restore save_exec_dir
3900 = make_scoped_restore (&execution_direction
,
3901 target_execution_direction ());
3903 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3906 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3908 /* Switch to the target that generated the event, so we can do
3909 target calls. Any inferior bound to the target will do, so we
3910 just switch to the first we find. */
3911 for (inferior
*inf
: all_inferiors (ecs
->target
))
3913 switch_to_inferior_no_thread (inf
);
3918 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3920 /* If an error happens while handling the event, propagate GDB's
3921 knowledge of the executing state to the frontend/user running
3923 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3924 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3926 /* Get executed before scoped_restore_current_thread above to apply
3927 still for the thread which has thrown the exception. */
3928 auto defer_bpstat_clear
3929 = make_scope_exit (bpstat_clear_actions
);
3930 auto defer_delete_threads
3931 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3933 /* Now figure out what to do with the result of the result. */
3934 handle_inferior_event (ecs
);
3936 if (!ecs
->wait_some_more
)
3938 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3939 int should_stop
= 1;
3940 struct thread_info
*thr
= ecs
->event_thread
;
3942 delete_just_stopped_threads_infrun_breakpoints ();
3946 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3948 if (thread_fsm
!= NULL
)
3949 should_stop
= thread_fsm
->should_stop (thr
);
3958 bool should_notify_stop
= true;
3961 clean_up_just_stopped_threads_fsms (ecs
);
3963 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3964 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3966 if (should_notify_stop
)
3968 /* We may not find an inferior if this was a process exit. */
3969 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3970 proceeded
= normal_stop ();
3975 inferior_event_handler (INF_EXEC_COMPLETE
);
3979 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3980 previously selected thread is gone. We have two
3981 choices - switch to no thread selected, or restore the
3982 previously selected thread (now exited). We chose the
3983 later, just because that's what GDB used to do. After
3984 this, "info threads" says "The current thread <Thread
3985 ID 2> has terminated." instead of "No thread
3989 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3990 restore_thread
.dont_restore ();
3994 defer_delete_threads
.release ();
3995 defer_bpstat_clear
.release ();
3997 /* No error, don't finish the thread states yet. */
3998 finish_state
.release ();
4000 /* This scope is used to ensure that readline callbacks are
4001 reinstalled here. */
4004 /* If a UI was in sync execution mode, and now isn't, restore its
4005 prompt (a synchronous execution command has finished, and we're
4006 ready for input). */
4007 all_uis_check_sync_execution_done ();
4010 && exec_done_display_p
4011 && (inferior_ptid
== null_ptid
4012 || inferior_thread ()->state
!= THREAD_RUNNING
))
4013 printf_unfiltered (_("completed.\n"));
4019 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4020 struct symtab_and_line sal
)
4022 /* This can be removed once this function no longer implicitly relies on the
4023 inferior_ptid value. */
4024 gdb_assert (inferior_ptid
== tp
->ptid
);
4026 tp
->control
.step_frame_id
= get_frame_id (frame
);
4027 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4029 tp
->current_symtab
= sal
.symtab
;
4030 tp
->current_line
= sal
.line
;
4033 /* Clear context switchable stepping state. */
4036 init_thread_stepping_state (struct thread_info
*tss
)
4038 tss
->stepped_breakpoint
= 0;
4039 tss
->stepping_over_breakpoint
= 0;
4040 tss
->stepping_over_watchpoint
= 0;
4041 tss
->step_after_step_resume_breakpoint
= 0;
4047 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4048 target_waitstatus status
)
4050 target_last_proc_target
= target
;
4051 target_last_wait_ptid
= ptid
;
4052 target_last_waitstatus
= status
;
4058 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4059 target_waitstatus
*status
)
4061 if (target
!= nullptr)
4062 *target
= target_last_proc_target
;
4063 if (ptid
!= nullptr)
4064 *ptid
= target_last_wait_ptid
;
4065 if (status
!= nullptr)
4066 *status
= target_last_waitstatus
;
4072 nullify_last_target_wait_ptid (void)
4074 target_last_proc_target
= nullptr;
4075 target_last_wait_ptid
= minus_one_ptid
;
4076 target_last_waitstatus
= {};
4079 /* Switch thread contexts. */
4082 context_switch (execution_control_state
*ecs
)
4084 if (ecs
->ptid
!= inferior_ptid
4085 && (inferior_ptid
== null_ptid
4086 || ecs
->event_thread
!= inferior_thread ()))
4088 infrun_log_debug ("Switching context from %s to %s",
4089 target_pid_to_str (inferior_ptid
).c_str (),
4090 target_pid_to_str (ecs
->ptid
).c_str ());
4093 switch_to_thread (ecs
->event_thread
);
4096 /* If the target can't tell whether we've hit breakpoints
4097 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4098 check whether that could have been caused by a breakpoint. If so,
4099 adjust the PC, per gdbarch_decr_pc_after_break. */
4102 adjust_pc_after_break (struct thread_info
*thread
,
4103 struct target_waitstatus
*ws
)
4105 struct regcache
*regcache
;
4106 struct gdbarch
*gdbarch
;
4107 CORE_ADDR breakpoint_pc
, decr_pc
;
4109 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4110 we aren't, just return.
4112 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4113 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4114 implemented by software breakpoints should be handled through the normal
4117 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4118 different signals (SIGILL or SIGEMT for instance), but it is less
4119 clear where the PC is pointing afterwards. It may not match
4120 gdbarch_decr_pc_after_break. I don't know any specific target that
4121 generates these signals at breakpoints (the code has been in GDB since at
4122 least 1992) so I can not guess how to handle them here.
4124 In earlier versions of GDB, a target with
4125 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4126 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4127 target with both of these set in GDB history, and it seems unlikely to be
4128 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4130 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4133 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4136 /* In reverse execution, when a breakpoint is hit, the instruction
4137 under it has already been de-executed. The reported PC always
4138 points at the breakpoint address, so adjusting it further would
4139 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4142 B1 0x08000000 : INSN1
4143 B2 0x08000001 : INSN2
4145 PC -> 0x08000003 : INSN4
4147 Say you're stopped at 0x08000003 as above. Reverse continuing
4148 from that point should hit B2 as below. Reading the PC when the
4149 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4150 been de-executed already.
4152 B1 0x08000000 : INSN1
4153 B2 PC -> 0x08000001 : INSN2
4157 We can't apply the same logic as for forward execution, because
4158 we would wrongly adjust the PC to 0x08000000, since there's a
4159 breakpoint at PC - 1. We'd then report a hit on B1, although
4160 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4162 if (execution_direction
== EXEC_REVERSE
)
4165 /* If the target can tell whether the thread hit a SW breakpoint,
4166 trust it. Targets that can tell also adjust the PC
4168 if (target_supports_stopped_by_sw_breakpoint ())
4171 /* Note that relying on whether a breakpoint is planted in memory to
4172 determine this can fail. E.g,. the breakpoint could have been
4173 removed since. Or the thread could have been told to step an
4174 instruction the size of a breakpoint instruction, and only
4175 _after_ was a breakpoint inserted at its address. */
4177 /* If this target does not decrement the PC after breakpoints, then
4178 we have nothing to do. */
4179 regcache
= get_thread_regcache (thread
);
4180 gdbarch
= regcache
->arch ();
4182 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4186 const address_space
*aspace
= regcache
->aspace ();
4188 /* Find the location where (if we've hit a breakpoint) the
4189 breakpoint would be. */
4190 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4192 /* If the target can't tell whether a software breakpoint triggered,
4193 fallback to figuring it out based on breakpoints we think were
4194 inserted in the target, and on whether the thread was stepped or
4197 /* Check whether there actually is a software breakpoint inserted at
4200 If in non-stop mode, a race condition is possible where we've
4201 removed a breakpoint, but stop events for that breakpoint were
4202 already queued and arrive later. To suppress those spurious
4203 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4204 and retire them after a number of stop events are reported. Note
4205 this is an heuristic and can thus get confused. The real fix is
4206 to get the "stopped by SW BP and needs adjustment" info out of
4207 the target/kernel (and thus never reach here; see above). */
4208 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4209 || (target_is_non_stop_p ()
4210 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4212 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4214 if (record_full_is_used ())
4215 restore_operation_disable
.emplace
4216 (record_full_gdb_operation_disable_set ());
4218 /* When using hardware single-step, a SIGTRAP is reported for both
4219 a completed single-step and a software breakpoint. Need to
4220 differentiate between the two, as the latter needs adjusting
4221 but the former does not.
4223 The SIGTRAP can be due to a completed hardware single-step only if
4224 - we didn't insert software single-step breakpoints
4225 - this thread is currently being stepped
4227 If any of these events did not occur, we must have stopped due
4228 to hitting a software breakpoint, and have to back up to the
4231 As a special case, we could have hardware single-stepped a
4232 software breakpoint. In this case (prev_pc == breakpoint_pc),
4233 we also need to back up to the breakpoint address. */
4235 if (thread_has_single_step_breakpoints_set (thread
)
4236 || !currently_stepping (thread
)
4237 || (thread
->stepped_breakpoint
4238 && thread
->prev_pc
== breakpoint_pc
))
4239 regcache_write_pc (regcache
, breakpoint_pc
);
4244 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4246 for (frame
= get_prev_frame (frame
);
4248 frame
= get_prev_frame (frame
))
4250 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4252 if (get_frame_type (frame
) != INLINE_FRAME
)
4259 /* Look for an inline frame that is marked for skip.
4260 If PREV_FRAME is TRUE start at the previous frame,
4261 otherwise start at the current frame. Stop at the
4262 first non-inline frame, or at the frame where the
4266 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4268 struct frame_info
*frame
= get_current_frame ();
4271 frame
= get_prev_frame (frame
);
4273 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4275 const char *fn
= NULL
;
4276 symtab_and_line sal
;
4279 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4281 if (get_frame_type (frame
) != INLINE_FRAME
)
4284 sal
= find_frame_sal (frame
);
4285 sym
= get_frame_function (frame
);
4288 fn
= sym
->print_name ();
4291 && function_name_is_marked_for_skip (fn
, sal
))
4298 /* If the event thread has the stop requested flag set, pretend it
4299 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4303 handle_stop_requested (struct execution_control_state
*ecs
)
4305 if (ecs
->event_thread
->stop_requested
)
4307 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4308 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4309 handle_signal_stop (ecs
);
4315 /* Auxiliary function that handles syscall entry/return events.
4316 It returns 1 if the inferior should keep going (and GDB
4317 should ignore the event), or 0 if the event deserves to be
4321 handle_syscall_event (struct execution_control_state
*ecs
)
4323 struct regcache
*regcache
;
4326 context_switch (ecs
);
4328 regcache
= get_thread_regcache (ecs
->event_thread
);
4329 syscall_number
= ecs
->ws
.value
.syscall_number
;
4330 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4332 if (catch_syscall_enabled () > 0
4333 && catching_syscall_number (syscall_number
) > 0)
4335 infrun_log_debug ("syscall number=%d", syscall_number
);
4337 ecs
->event_thread
->control
.stop_bpstat
4338 = bpstat_stop_status (regcache
->aspace (),
4339 ecs
->event_thread
->suspend
.stop_pc
,
4340 ecs
->event_thread
, &ecs
->ws
);
4342 if (handle_stop_requested (ecs
))
4345 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4347 /* Catchpoint hit. */
4352 if (handle_stop_requested (ecs
))
4355 /* If no catchpoint triggered for this, then keep going. */
4360 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4363 fill_in_stop_func (struct gdbarch
*gdbarch
,
4364 struct execution_control_state
*ecs
)
4366 if (!ecs
->stop_func_filled_in
)
4370 /* Don't care about return value; stop_func_start and stop_func_name
4371 will both be 0 if it doesn't work. */
4372 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4373 &ecs
->stop_func_name
,
4374 &ecs
->stop_func_start
,
4375 &ecs
->stop_func_end
,
4378 /* The call to find_pc_partial_function, above, will set
4379 stop_func_start and stop_func_end to the start and end
4380 of the range containing the stop pc. If this range
4381 contains the entry pc for the block (which is always the
4382 case for contiguous blocks), advance stop_func_start past
4383 the function's start offset and entrypoint. Note that
4384 stop_func_start is NOT advanced when in a range of a
4385 non-contiguous block that does not contain the entry pc. */
4386 if (block
!= nullptr
4387 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4388 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4390 ecs
->stop_func_start
4391 += gdbarch_deprecated_function_start_offset (gdbarch
);
4393 if (gdbarch_skip_entrypoint_p (gdbarch
))
4394 ecs
->stop_func_start
4395 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4398 ecs
->stop_func_filled_in
= 1;
4403 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4405 static enum stop_kind
4406 get_inferior_stop_soon (execution_control_state
*ecs
)
4408 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4410 gdb_assert (inf
!= NULL
);
4411 return inf
->control
.stop_soon
;
4414 /* Poll for one event out of the current target. Store the resulting
4415 waitstatus in WS, and return the event ptid. Does not block. */
4418 poll_one_curr_target (struct target_waitstatus
*ws
)
4422 overlay_cache_invalid
= 1;
4424 /* Flush target cache before starting to handle each event.
4425 Target was running and cache could be stale. This is just a
4426 heuristic. Running threads may modify target memory, but we
4427 don't get any event. */
4428 target_dcache_invalidate ();
4430 if (deprecated_target_wait_hook
)
4431 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4433 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4436 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4441 /* An event reported by wait_one. */
4443 struct wait_one_event
4445 /* The target the event came out of. */
4446 process_stratum_target
*target
;
4448 /* The PTID the event was for. */
4451 /* The waitstatus. */
4452 target_waitstatus ws
;
4455 /* Wait for one event out of any target. */
4457 static wait_one_event
4462 for (inferior
*inf
: all_inferiors ())
4464 process_stratum_target
*target
= inf
->process_target ();
4466 || !target
->is_async_p ()
4467 || !target
->threads_executing
)
4470 switch_to_inferior_no_thread (inf
);
4472 wait_one_event event
;
4473 event
.target
= target
;
4474 event
.ptid
= poll_one_curr_target (&event
.ws
);
4476 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4478 /* If nothing is resumed, remove the target from the
4482 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4486 /* Block waiting for some event. */
4493 for (inferior
*inf
: all_inferiors ())
4495 process_stratum_target
*target
= inf
->process_target ();
4497 || !target
->is_async_p ()
4498 || !target
->threads_executing
)
4501 int fd
= target
->async_wait_fd ();
4502 FD_SET (fd
, &readfds
);
4509 /* No waitable targets left. All must be stopped. */
4510 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4515 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4521 perror_with_name ("interruptible_select");
4526 /* Save the thread's event and stop reason to process it later. */
4529 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4531 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4532 target_waitstatus_to_string (ws
).c_str (),
4537 /* Record for later. */
4538 tp
->suspend
.waitstatus
= *ws
;
4539 tp
->suspend
.waitstatus_pending_p
= 1;
4541 struct regcache
*regcache
= get_thread_regcache (tp
);
4542 const address_space
*aspace
= regcache
->aspace ();
4544 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4545 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4547 CORE_ADDR pc
= regcache_read_pc (regcache
);
4549 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4551 scoped_restore_current_thread restore_thread
;
4552 switch_to_thread (tp
);
4554 if (target_stopped_by_watchpoint ())
4556 tp
->suspend
.stop_reason
4557 = TARGET_STOPPED_BY_WATCHPOINT
;
4559 else if (target_supports_stopped_by_sw_breakpoint ()
4560 && target_stopped_by_sw_breakpoint ())
4562 tp
->suspend
.stop_reason
4563 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4565 else if (target_supports_stopped_by_hw_breakpoint ()
4566 && target_stopped_by_hw_breakpoint ())
4568 tp
->suspend
.stop_reason
4569 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4571 else if (!target_supports_stopped_by_hw_breakpoint ()
4572 && hardware_breakpoint_inserted_here_p (aspace
,
4575 tp
->suspend
.stop_reason
4576 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4578 else if (!target_supports_stopped_by_sw_breakpoint ()
4579 && software_breakpoint_inserted_here_p (aspace
,
4582 tp
->suspend
.stop_reason
4583 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4585 else if (!thread_has_single_step_breakpoints_set (tp
)
4586 && currently_stepping (tp
))
4588 tp
->suspend
.stop_reason
4589 = TARGET_STOPPED_BY_SINGLE_STEP
;
4594 /* Mark the non-executing threads accordingly. In all-stop, all
4595 threads of all processes are stopped when we get any event
4596 reported. In non-stop mode, only the event thread stops. */
4599 mark_non_executing_threads (process_stratum_target
*target
,
4601 struct target_waitstatus ws
)
4605 if (!target_is_non_stop_p ())
4606 mark_ptid
= minus_one_ptid
;
4607 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4608 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4610 /* If we're handling a process exit in non-stop mode, even
4611 though threads haven't been deleted yet, one would think
4612 that there is nothing to do, as threads of the dead process
4613 will be soon deleted, and threads of any other process were
4614 left running. However, on some targets, threads survive a
4615 process exit event. E.g., for the "checkpoint" command,
4616 when the current checkpoint/fork exits, linux-fork.c
4617 automatically switches to another fork from within
4618 target_mourn_inferior, by associating the same
4619 inferior/thread to another fork. We haven't mourned yet at
4620 this point, but we must mark any threads left in the
4621 process as not-executing so that finish_thread_state marks
4622 them stopped (in the user's perspective) if/when we present
4623 the stop to the user. */
4624 mark_ptid
= ptid_t (event_ptid
.pid ());
4627 mark_ptid
= event_ptid
;
4629 set_executing (target
, mark_ptid
, false);
4631 /* Likewise the resumed flag. */
4632 set_resumed (target
, mark_ptid
, false);
4638 stop_all_threads (void)
4640 /* We may need multiple passes to discover all threads. */
4644 gdb_assert (exists_non_stop_target ());
4646 infrun_log_debug ("stop_all_threads");
4648 scoped_restore_current_thread restore_thread
;
4650 /* Enable thread events of all targets. */
4651 for (auto *target
: all_non_exited_process_targets ())
4653 switch_to_target_no_thread (target
);
4654 target_thread_events (true);
4659 /* Disable thread events of all targets. */
4660 for (auto *target
: all_non_exited_process_targets ())
4662 switch_to_target_no_thread (target
);
4663 target_thread_events (false);
4667 infrun_log_debug ("stop_all_threads done");
4670 /* Request threads to stop, and then wait for the stops. Because
4671 threads we already know about can spawn more threads while we're
4672 trying to stop them, and we only learn about new threads when we
4673 update the thread list, do this in a loop, and keep iterating
4674 until two passes find no threads that need to be stopped. */
4675 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4677 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4681 int waits_needed
= 0;
4683 for (auto *target
: all_non_exited_process_targets ())
4685 switch_to_target_no_thread (target
);
4686 update_thread_list ();
4689 /* Go through all threads looking for threads that we need
4690 to tell the target to stop. */
4691 for (thread_info
*t
: all_non_exited_threads ())
4693 /* For a single-target setting with an all-stop target,
4694 we would not even arrive here. For a multi-target
4695 setting, until GDB is able to handle a mixture of
4696 all-stop and non-stop targets, simply skip all-stop
4697 targets' threads. This should be fine due to the
4698 protection of 'check_multi_target_resumption'. */
4700 switch_to_thread_no_regs (t
);
4701 if (!target_is_non_stop_p ())
4706 /* If already stopping, don't request a stop again.
4707 We just haven't seen the notification yet. */
4708 if (!t
->stop_requested
)
4710 infrun_log_debug (" %s executing, need stop",
4711 target_pid_to_str (t
->ptid
).c_str ());
4712 target_stop (t
->ptid
);
4713 t
->stop_requested
= 1;
4717 infrun_log_debug (" %s executing, already stopping",
4718 target_pid_to_str (t
->ptid
).c_str ());
4721 if (t
->stop_requested
)
4726 infrun_log_debug (" %s not executing",
4727 target_pid_to_str (t
->ptid
).c_str ());
4729 /* The thread may be not executing, but still be
4730 resumed with a pending status to process. */
4735 if (waits_needed
== 0)
4738 /* If we find new threads on the second iteration, restart
4739 over. We want to see two iterations in a row with all
4744 for (int i
= 0; i
< waits_needed
; i
++)
4746 wait_one_event event
= wait_one ();
4748 infrun_log_debug ("%s %s\n",
4749 target_waitstatus_to_string (&event
.ws
).c_str (),
4750 target_pid_to_str (event
.ptid
).c_str ());
4752 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4754 /* All resumed threads exited. */
4757 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4758 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4759 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4761 /* One thread/process exited/signalled. */
4763 thread_info
*t
= nullptr;
4765 /* The target may have reported just a pid. If so, try
4766 the first non-exited thread. */
4767 if (event
.ptid
.is_pid ())
4769 int pid
= event
.ptid
.pid ();
4770 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4771 for (thread_info
*tp
: inf
->non_exited_threads ())
4777 /* If there is no available thread, the event would
4778 have to be appended to a per-inferior event list,
4779 which does not exist (and if it did, we'd have
4780 to adjust run control command to be able to
4781 resume such an inferior). We assert here instead
4782 of going into an infinite loop. */
4783 gdb_assert (t
!= nullptr);
4785 infrun_log_debug ("using %s\n",
4786 target_pid_to_str (t
->ptid
).c_str ());
4790 t
= find_thread_ptid (event
.target
, event
.ptid
);
4791 /* Check if this is the first time we see this thread.
4792 Don't bother adding if it individually exited. */
4794 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4795 t
= add_thread (event
.target
, event
.ptid
);
4800 /* Set the threads as non-executing to avoid
4801 another stop attempt on them. */
4802 switch_to_thread_no_regs (t
);
4803 mark_non_executing_threads (event
.target
, event
.ptid
,
4805 save_waitstatus (t
, &event
.ws
);
4806 t
->stop_requested
= false;
4811 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4813 t
= add_thread (event
.target
, event
.ptid
);
4815 t
->stop_requested
= 0;
4818 t
->control
.may_range_step
= 0;
4820 /* This may be the first time we see the inferior report
4822 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4823 if (inf
->needs_setup
)
4825 switch_to_thread_no_regs (t
);
4829 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4830 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4832 /* We caught the event that we intended to catch, so
4833 there's no event pending. */
4834 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4835 t
->suspend
.waitstatus_pending_p
= 0;
4837 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4839 /* Add it back to the step-over queue. */
4840 infrun_log_debug ("displaced-step of %s "
4841 "canceled: adding back to the "
4842 "step-over queue\n",
4843 target_pid_to_str (t
->ptid
).c_str ());
4845 t
->control
.trap_expected
= 0;
4846 global_thread_step_over_chain_enqueue (t
);
4851 enum gdb_signal sig
;
4852 struct regcache
*regcache
;
4856 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4858 infrun_log_debug ("target_wait %s, saving "
4859 "status for %d.%ld.%ld\n",
4866 /* Record for later. */
4867 save_waitstatus (t
, &event
.ws
);
4869 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4870 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4872 if (displaced_step_fixup (t
, sig
) < 0)
4874 /* Add it back to the step-over queue. */
4875 t
->control
.trap_expected
= 0;
4876 global_thread_step_over_chain_enqueue (t
);
4879 regcache
= get_thread_regcache (t
);
4880 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4882 infrun_log_debug ("saved stop_pc=%s for %s "
4883 "(currently_stepping=%d)\n",
4884 paddress (target_gdbarch (),
4885 t
->suspend
.stop_pc
),
4886 target_pid_to_str (t
->ptid
).c_str (),
4887 currently_stepping (t
));
4895 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4898 handle_no_resumed (struct execution_control_state
*ecs
)
4900 if (target_can_async_p ())
4904 for (ui
*ui
: all_uis ())
4906 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4914 /* There were no unwaited-for children left in the target, but,
4915 we're not synchronously waiting for events either. Just
4918 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4919 prepare_to_wait (ecs
);
4924 /* Otherwise, if we were running a synchronous execution command, we
4925 may need to cancel it and give the user back the terminal.
4927 In non-stop mode, the target can't tell whether we've already
4928 consumed previous stop events, so it can end up sending us a
4929 no-resumed event like so:
4931 #0 - thread 1 is left stopped
4933 #1 - thread 2 is resumed and hits breakpoint
4934 -> TARGET_WAITKIND_STOPPED
4936 #2 - thread 3 is resumed and exits
4937 this is the last resumed thread, so
4938 -> TARGET_WAITKIND_NO_RESUMED
4940 #3 - gdb processes stop for thread 2 and decides to re-resume
4943 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4944 thread 2 is now resumed, so the event should be ignored.
4946 IOW, if the stop for thread 2 doesn't end a foreground command,
4947 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4948 event. But it could be that the event meant that thread 2 itself
4949 (or whatever other thread was the last resumed thread) exited.
4951 To address this we refresh the thread list and check whether we
4952 have resumed threads _now_. In the example above, this removes
4953 thread 3 from the thread list. If thread 2 was re-resumed, we
4954 ignore this event. If we find no thread resumed, then we cancel
4955 the synchronous command and show "no unwaited-for " to the
4958 inferior
*curr_inf
= current_inferior ();
4960 scoped_restore_current_thread restore_thread
;
4962 for (auto *target
: all_non_exited_process_targets ())
4964 switch_to_target_no_thread (target
);
4965 update_thread_list ();
4970 - the current target has no thread executing, and
4971 - the current inferior is native, and
4972 - the current inferior is the one which has the terminal, and
4975 then a Ctrl-C from this point on would remain stuck in the
4976 kernel, until a thread resumes and dequeues it. That would
4977 result in the GDB CLI not reacting to Ctrl-C, not able to
4978 interrupt the program. To address this, if the current inferior
4979 no longer has any thread executing, we give the terminal to some
4980 other inferior that has at least one thread executing. */
4981 bool swap_terminal
= true;
4983 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4984 whether to report it to the user. */
4985 bool ignore_event
= false;
4987 for (thread_info
*thread
: all_non_exited_threads ())
4989 if (swap_terminal
&& thread
->executing
)
4991 if (thread
->inf
!= curr_inf
)
4993 target_terminal::ours ();
4995 switch_to_thread (thread
);
4996 target_terminal::inferior ();
4998 swap_terminal
= false;
5002 && (thread
->executing
5003 || thread
->suspend
.waitstatus_pending_p
))
5005 /* Either there were no unwaited-for children left in the
5006 target at some point, but there are now, or some target
5007 other than the eventing one has unwaited-for children
5008 left. Just ignore. */
5009 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
5010 "(ignoring: found resumed)\n");
5012 ignore_event
= true;
5015 if (ignore_event
&& !swap_terminal
)
5021 switch_to_inferior_no_thread (curr_inf
);
5022 prepare_to_wait (ecs
);
5026 /* Go ahead and report the event. */
5030 /* Given an execution control state that has been freshly filled in by
5031 an event from the inferior, figure out what it means and take
5034 The alternatives are:
5036 1) stop_waiting and return; to really stop and return to the
5039 2) keep_going and return; to wait for the next event (set
5040 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5044 handle_inferior_event (struct execution_control_state
*ecs
)
5046 /* Make sure that all temporary struct value objects that were
5047 created during the handling of the event get deleted at the
5049 scoped_value_mark free_values
;
5051 enum stop_kind stop_soon
;
5053 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5055 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5057 /* We had an event in the inferior, but we are not interested in
5058 handling it at this level. The lower layers have already
5059 done what needs to be done, if anything.
5061 One of the possible circumstances for this is when the
5062 inferior produces output for the console. The inferior has
5063 not stopped, and we are ignoring the event. Another possible
5064 circumstance is any event which the lower level knows will be
5065 reported multiple times without an intervening resume. */
5066 prepare_to_wait (ecs
);
5070 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5072 prepare_to_wait (ecs
);
5076 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5077 && handle_no_resumed (ecs
))
5080 /* Cache the last target/ptid/waitstatus. */
5081 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5083 /* Always clear state belonging to the previous time we stopped. */
5084 stop_stack_dummy
= STOP_NONE
;
5086 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5088 /* No unwaited-for children left. IOW, all resumed children
5090 stop_print_frame
= 0;
5095 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5096 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5098 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5099 /* If it's a new thread, add it to the thread database. */
5100 if (ecs
->event_thread
== NULL
)
5101 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5103 /* Disable range stepping. If the next step request could use a
5104 range, this will be end up re-enabled then. */
5105 ecs
->event_thread
->control
.may_range_step
= 0;
5108 /* Dependent on valid ECS->EVENT_THREAD. */
5109 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5111 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5112 reinit_frame_cache ();
5114 breakpoint_retire_moribund ();
5116 /* First, distinguish signals caused by the debugger from signals
5117 that have to do with the program's own actions. Note that
5118 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5119 on the operating system version. Here we detect when a SIGILL or
5120 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5121 something similar for SIGSEGV, since a SIGSEGV will be generated
5122 when we're trying to execute a breakpoint instruction on a
5123 non-executable stack. This happens for call dummy breakpoints
5124 for architectures like SPARC that place call dummies on the
5126 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5127 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5128 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5129 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5131 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5133 if (breakpoint_inserted_here_p (regcache
->aspace (),
5134 regcache_read_pc (regcache
)))
5136 infrun_log_debug ("Treating signal as SIGTRAP");
5137 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5141 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5143 switch (ecs
->ws
.kind
)
5145 case TARGET_WAITKIND_LOADED
:
5146 context_switch (ecs
);
5147 /* Ignore gracefully during startup of the inferior, as it might
5148 be the shell which has just loaded some objects, otherwise
5149 add the symbols for the newly loaded objects. Also ignore at
5150 the beginning of an attach or remote session; we will query
5151 the full list of libraries once the connection is
5154 stop_soon
= get_inferior_stop_soon (ecs
);
5155 if (stop_soon
== NO_STOP_QUIETLY
)
5157 struct regcache
*regcache
;
5159 regcache
= get_thread_regcache (ecs
->event_thread
);
5161 handle_solib_event ();
5163 ecs
->event_thread
->control
.stop_bpstat
5164 = bpstat_stop_status (regcache
->aspace (),
5165 ecs
->event_thread
->suspend
.stop_pc
,
5166 ecs
->event_thread
, &ecs
->ws
);
5168 if (handle_stop_requested (ecs
))
5171 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5173 /* A catchpoint triggered. */
5174 process_event_stop_test (ecs
);
5178 /* If requested, stop when the dynamic linker notifies
5179 gdb of events. This allows the user to get control
5180 and place breakpoints in initializer routines for
5181 dynamically loaded objects (among other things). */
5182 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5183 if (stop_on_solib_events
)
5185 /* Make sure we print "Stopped due to solib-event" in
5187 stop_print_frame
= 1;
5194 /* If we are skipping through a shell, or through shared library
5195 loading that we aren't interested in, resume the program. If
5196 we're running the program normally, also resume. */
5197 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5199 /* Loading of shared libraries might have changed breakpoint
5200 addresses. Make sure new breakpoints are inserted. */
5201 if (stop_soon
== NO_STOP_QUIETLY
)
5202 insert_breakpoints ();
5203 resume (GDB_SIGNAL_0
);
5204 prepare_to_wait (ecs
);
5208 /* But stop if we're attaching or setting up a remote
5210 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5211 || stop_soon
== STOP_QUIETLY_REMOTE
)
5213 infrun_log_debug ("quietly stopped");
5218 internal_error (__FILE__
, __LINE__
,
5219 _("unhandled stop_soon: %d"), (int) stop_soon
);
5221 case TARGET_WAITKIND_SPURIOUS
:
5222 if (handle_stop_requested (ecs
))
5224 context_switch (ecs
);
5225 resume (GDB_SIGNAL_0
);
5226 prepare_to_wait (ecs
);
5229 case TARGET_WAITKIND_THREAD_CREATED
:
5230 if (handle_stop_requested (ecs
))
5232 context_switch (ecs
);
5233 if (!switch_back_to_stepped_thread (ecs
))
5237 case TARGET_WAITKIND_EXITED
:
5238 case TARGET_WAITKIND_SIGNALLED
:
5240 /* Depending on the system, ecs->ptid may point to a thread or
5241 to a process. On some targets, target_mourn_inferior may
5242 need to have access to the just-exited thread. That is the
5243 case of GNU/Linux's "checkpoint" support, for example.
5244 Call the switch_to_xxx routine as appropriate. */
5245 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5247 switch_to_thread (thr
);
5250 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5251 switch_to_inferior_no_thread (inf
);
5254 handle_vfork_child_exec_or_exit (0);
5255 target_terminal::ours (); /* Must do this before mourn anyway. */
5257 /* Clearing any previous state of convenience variables. */
5258 clear_exit_convenience_vars ();
5260 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5262 /* Record the exit code in the convenience variable $_exitcode, so
5263 that the user can inspect this again later. */
5264 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5265 (LONGEST
) ecs
->ws
.value
.integer
);
5267 /* Also record this in the inferior itself. */
5268 current_inferior ()->has_exit_code
= 1;
5269 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5271 /* Support the --return-child-result option. */
5272 return_child_result_value
= ecs
->ws
.value
.integer
;
5274 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5278 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5280 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5282 /* Set the value of the internal variable $_exitsignal,
5283 which holds the signal uncaught by the inferior. */
5284 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5285 gdbarch_gdb_signal_to_target (gdbarch
,
5286 ecs
->ws
.value
.sig
));
5290 /* We don't have access to the target's method used for
5291 converting between signal numbers (GDB's internal
5292 representation <-> target's representation).
5293 Therefore, we cannot do a good job at displaying this
5294 information to the user. It's better to just warn
5295 her about it (if infrun debugging is enabled), and
5297 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5301 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5304 gdb_flush (gdb_stdout
);
5305 target_mourn_inferior (inferior_ptid
);
5306 stop_print_frame
= 0;
5310 case TARGET_WAITKIND_FORKED
:
5311 case TARGET_WAITKIND_VFORKED
:
5312 /* Check whether the inferior is displaced stepping. */
5314 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5315 struct gdbarch
*gdbarch
= regcache
->arch ();
5317 /* If checking displaced stepping is supported, and thread
5318 ecs->ptid is displaced stepping. */
5319 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5321 struct inferior
*parent_inf
5322 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5323 struct regcache
*child_regcache
;
5324 CORE_ADDR parent_pc
;
5326 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5328 struct displaced_step_inferior_state
*displaced
5329 = get_displaced_stepping_state (parent_inf
);
5331 /* Restore scratch pad for child process. */
5332 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5335 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5336 indicating that the displaced stepping of syscall instruction
5337 has been done. Perform cleanup for parent process here. Note
5338 that this operation also cleans up the child process for vfork,
5339 because their pages are shared. */
5340 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5341 /* Start a new step-over in another thread if there's one
5345 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5346 the child's PC is also within the scratchpad. Set the child's PC
5347 to the parent's PC value, which has already been fixed up.
5348 FIXME: we use the parent's aspace here, although we're touching
5349 the child, because the child hasn't been added to the inferior
5350 list yet at this point. */
5353 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5354 ecs
->ws
.value
.related_pid
,
5356 parent_inf
->aspace
);
5357 /* Read PC value of parent process. */
5358 parent_pc
= regcache_read_pc (regcache
);
5360 if (debug_displaced
)
5361 fprintf_unfiltered (gdb_stdlog
,
5362 "displaced: write child pc from %s to %s\n",
5364 regcache_read_pc (child_regcache
)),
5365 paddress (gdbarch
, parent_pc
));
5367 regcache_write_pc (child_regcache
, parent_pc
);
5371 context_switch (ecs
);
5373 /* Immediately detach breakpoints from the child before there's
5374 any chance of letting the user delete breakpoints from the
5375 breakpoint lists. If we don't do this early, it's easy to
5376 leave left over traps in the child, vis: "break foo; catch
5377 fork; c; <fork>; del; c; <child calls foo>". We only follow
5378 the fork on the last `continue', and by that time the
5379 breakpoint at "foo" is long gone from the breakpoint table.
5380 If we vforked, then we don't need to unpatch here, since both
5381 parent and child are sharing the same memory pages; we'll
5382 need to unpatch at follow/detach time instead to be certain
5383 that new breakpoints added between catchpoint hit time and
5384 vfork follow are detached. */
5385 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5387 /* This won't actually modify the breakpoint list, but will
5388 physically remove the breakpoints from the child. */
5389 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5392 delete_just_stopped_threads_single_step_breakpoints ();
5394 /* In case the event is caught by a catchpoint, remember that
5395 the event is to be followed at the next resume of the thread,
5396 and not immediately. */
5397 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5399 ecs
->event_thread
->suspend
.stop_pc
5400 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5402 ecs
->event_thread
->control
.stop_bpstat
5403 = bpstat_stop_status (get_current_regcache ()->aspace (),
5404 ecs
->event_thread
->suspend
.stop_pc
,
5405 ecs
->event_thread
, &ecs
->ws
);
5407 if (handle_stop_requested (ecs
))
5410 /* If no catchpoint triggered for this, then keep going. Note
5411 that we're interested in knowing the bpstat actually causes a
5412 stop, not just if it may explain the signal. Software
5413 watchpoints, for example, always appear in the bpstat. */
5414 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5417 = (follow_fork_mode_string
== follow_fork_mode_child
);
5419 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5421 process_stratum_target
*targ
5422 = ecs
->event_thread
->inf
->process_target ();
5424 bool should_resume
= follow_fork ();
5426 /* Note that one of these may be an invalid pointer,
5427 depending on detach_fork. */
5428 thread_info
*parent
= ecs
->event_thread
;
5430 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5432 /* At this point, the parent is marked running, and the
5433 child is marked stopped. */
5435 /* If not resuming the parent, mark it stopped. */
5436 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5437 parent
->set_running (false);
5439 /* If resuming the child, mark it running. */
5440 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5441 child
->set_running (true);
5443 /* In non-stop mode, also resume the other branch. */
5444 if (!detach_fork
&& (non_stop
5445 || (sched_multi
&& target_is_non_stop_p ())))
5448 switch_to_thread (parent
);
5450 switch_to_thread (child
);
5452 ecs
->event_thread
= inferior_thread ();
5453 ecs
->ptid
= inferior_ptid
;
5458 switch_to_thread (child
);
5460 switch_to_thread (parent
);
5462 ecs
->event_thread
= inferior_thread ();
5463 ecs
->ptid
= inferior_ptid
;
5471 process_event_stop_test (ecs
);
5474 case TARGET_WAITKIND_VFORK_DONE
:
5475 /* Done with the shared memory region. Re-insert breakpoints in
5476 the parent, and keep going. */
5478 context_switch (ecs
);
5480 current_inferior ()->waiting_for_vfork_done
= 0;
5481 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5483 if (handle_stop_requested (ecs
))
5486 /* This also takes care of reinserting breakpoints in the
5487 previously locked inferior. */
5491 case TARGET_WAITKIND_EXECD
:
5493 /* Note we can't read registers yet (the stop_pc), because we
5494 don't yet know the inferior's post-exec architecture.
5495 'stop_pc' is explicitly read below instead. */
5496 switch_to_thread_no_regs (ecs
->event_thread
);
5498 /* Do whatever is necessary to the parent branch of the vfork. */
5499 handle_vfork_child_exec_or_exit (1);
5501 /* This causes the eventpoints and symbol table to be reset.
5502 Must do this now, before trying to determine whether to
5504 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5506 /* In follow_exec we may have deleted the original thread and
5507 created a new one. Make sure that the event thread is the
5508 execd thread for that case (this is a nop otherwise). */
5509 ecs
->event_thread
= inferior_thread ();
5511 ecs
->event_thread
->suspend
.stop_pc
5512 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5514 ecs
->event_thread
->control
.stop_bpstat
5515 = bpstat_stop_status (get_current_regcache ()->aspace (),
5516 ecs
->event_thread
->suspend
.stop_pc
,
5517 ecs
->event_thread
, &ecs
->ws
);
5519 /* Note that this may be referenced from inside
5520 bpstat_stop_status above, through inferior_has_execd. */
5521 xfree (ecs
->ws
.value
.execd_pathname
);
5522 ecs
->ws
.value
.execd_pathname
= NULL
;
5524 if (handle_stop_requested (ecs
))
5527 /* If no catchpoint triggered for this, then keep going. */
5528 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5530 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5534 process_event_stop_test (ecs
);
5537 /* Be careful not to try to gather much state about a thread
5538 that's in a syscall. It's frequently a losing proposition. */
5539 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5540 /* Getting the current syscall number. */
5541 if (handle_syscall_event (ecs
) == 0)
5542 process_event_stop_test (ecs
);
5545 /* Before examining the threads further, step this thread to
5546 get it entirely out of the syscall. (We get notice of the
5547 event when the thread is just on the verge of exiting a
5548 syscall. Stepping one instruction seems to get it back
5550 case TARGET_WAITKIND_SYSCALL_RETURN
:
5551 if (handle_syscall_event (ecs
) == 0)
5552 process_event_stop_test (ecs
);
5555 case TARGET_WAITKIND_STOPPED
:
5556 handle_signal_stop (ecs
);
5559 case TARGET_WAITKIND_NO_HISTORY
:
5560 /* Reverse execution: target ran out of history info. */
5562 /* Switch to the stopped thread. */
5563 context_switch (ecs
);
5564 infrun_log_debug ("stopped");
5566 delete_just_stopped_threads_single_step_breakpoints ();
5567 ecs
->event_thread
->suspend
.stop_pc
5568 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5570 if (handle_stop_requested (ecs
))
5573 gdb::observers::no_history
.notify ();
5579 /* Restart threads back to what they were trying to do back when we
5580 paused them for an in-line step-over. The EVENT_THREAD thread is
5584 restart_threads (struct thread_info
*event_thread
)
5586 /* In case the instruction just stepped spawned a new thread. */
5587 update_thread_list ();
5589 for (thread_info
*tp
: all_non_exited_threads ())
5591 switch_to_thread_no_regs (tp
);
5593 if (tp
== event_thread
)
5595 infrun_log_debug ("restart threads: [%s] is event thread",
5596 target_pid_to_str (tp
->ptid
).c_str ());
5600 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5602 infrun_log_debug ("restart threads: [%s] not meant to be running",
5603 target_pid_to_str (tp
->ptid
).c_str ());
5609 infrun_log_debug ("restart threads: [%s] resumed",
5610 target_pid_to_str (tp
->ptid
).c_str ());
5611 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5615 if (thread_is_in_step_over_chain (tp
))
5617 infrun_log_debug ("restart threads: [%s] needs step-over",
5618 target_pid_to_str (tp
->ptid
).c_str ());
5619 gdb_assert (!tp
->resumed
);
5624 if (tp
->suspend
.waitstatus_pending_p
)
5626 infrun_log_debug ("restart threads: [%s] has pending status",
5627 target_pid_to_str (tp
->ptid
).c_str ());
5632 gdb_assert (!tp
->stop_requested
);
5634 /* If some thread needs to start a step-over at this point, it
5635 should still be in the step-over queue, and thus skipped
5637 if (thread_still_needs_step_over (tp
))
5639 internal_error (__FILE__
, __LINE__
,
5640 "thread [%s] needs a step-over, but not in "
5641 "step-over queue\n",
5642 target_pid_to_str (tp
->ptid
).c_str ());
5645 if (currently_stepping (tp
))
5647 infrun_log_debug ("restart threads: [%s] was stepping",
5648 target_pid_to_str (tp
->ptid
).c_str ());
5649 keep_going_stepped_thread (tp
);
5653 struct execution_control_state ecss
;
5654 struct execution_control_state
*ecs
= &ecss
;
5656 infrun_log_debug ("restart threads: [%s] continuing",
5657 target_pid_to_str (tp
->ptid
).c_str ());
5658 reset_ecs (ecs
, tp
);
5659 switch_to_thread (tp
);
5660 keep_going_pass_signal (ecs
);
5665 /* Callback for iterate_over_threads. Find a resumed thread that has
5666 a pending waitstatus. */
5669 resumed_thread_with_pending_status (struct thread_info
*tp
,
5673 && tp
->suspend
.waitstatus_pending_p
);
5676 /* Called when we get an event that may finish an in-line or
5677 out-of-line (displaced stepping) step-over started previously.
5678 Return true if the event is processed and we should go back to the
5679 event loop; false if the caller should continue processing the
5683 finish_step_over (struct execution_control_state
*ecs
)
5685 int had_step_over_info
;
5687 displaced_step_fixup (ecs
->event_thread
,
5688 ecs
->event_thread
->suspend
.stop_signal
);
5690 had_step_over_info
= step_over_info_valid_p ();
5692 if (had_step_over_info
)
5694 /* If we're stepping over a breakpoint with all threads locked,
5695 then only the thread that was stepped should be reporting
5697 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5699 clear_step_over_info ();
5702 if (!target_is_non_stop_p ())
5705 /* Start a new step-over in another thread if there's one that
5709 /* If we were stepping over a breakpoint before, and haven't started
5710 a new in-line step-over sequence, then restart all other threads
5711 (except the event thread). We can't do this in all-stop, as then
5712 e.g., we wouldn't be able to issue any other remote packet until
5713 these other threads stop. */
5714 if (had_step_over_info
&& !step_over_info_valid_p ())
5716 struct thread_info
*pending
;
5718 /* If we only have threads with pending statuses, the restart
5719 below won't restart any thread and so nothing re-inserts the
5720 breakpoint we just stepped over. But we need it inserted
5721 when we later process the pending events, otherwise if
5722 another thread has a pending event for this breakpoint too,
5723 we'd discard its event (because the breakpoint that
5724 originally caused the event was no longer inserted). */
5725 context_switch (ecs
);
5726 insert_breakpoints ();
5728 restart_threads (ecs
->event_thread
);
5730 /* If we have events pending, go through handle_inferior_event
5731 again, picking up a pending event at random. This avoids
5732 thread starvation. */
5734 /* But not if we just stepped over a watchpoint in order to let
5735 the instruction execute so we can evaluate its expression.
5736 The set of watchpoints that triggered is recorded in the
5737 breakpoint objects themselves (see bp->watchpoint_triggered).
5738 If we processed another event first, that other event could
5739 clobber this info. */
5740 if (ecs
->event_thread
->stepping_over_watchpoint
)
5743 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5745 if (pending
!= NULL
)
5747 struct thread_info
*tp
= ecs
->event_thread
;
5748 struct regcache
*regcache
;
5750 infrun_log_debug ("found resumed threads with "
5751 "pending events, saving status");
5753 gdb_assert (pending
!= tp
);
5755 /* Record the event thread's event for later. */
5756 save_waitstatus (tp
, &ecs
->ws
);
5757 /* This was cleared early, by handle_inferior_event. Set it
5758 so this pending event is considered by
5762 gdb_assert (!tp
->executing
);
5764 regcache
= get_thread_regcache (tp
);
5765 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5767 infrun_log_debug ("saved stop_pc=%s for %s "
5768 "(currently_stepping=%d)\n",
5769 paddress (target_gdbarch (),
5770 tp
->suspend
.stop_pc
),
5771 target_pid_to_str (tp
->ptid
).c_str (),
5772 currently_stepping (tp
));
5774 /* This in-line step-over finished; clear this so we won't
5775 start a new one. This is what handle_signal_stop would
5776 do, if we returned false. */
5777 tp
->stepping_over_breakpoint
= 0;
5779 /* Wake up the event loop again. */
5780 mark_async_event_handler (infrun_async_inferior_event_token
);
5782 prepare_to_wait (ecs
);
5790 /* Come here when the program has stopped with a signal. */
5793 handle_signal_stop (struct execution_control_state
*ecs
)
5795 struct frame_info
*frame
;
5796 struct gdbarch
*gdbarch
;
5797 int stopped_by_watchpoint
;
5798 enum stop_kind stop_soon
;
5801 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5803 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5805 /* Do we need to clean up the state of a thread that has
5806 completed a displaced single-step? (Doing so usually affects
5807 the PC, so do it here, before we set stop_pc.) */
5808 if (finish_step_over (ecs
))
5811 /* If we either finished a single-step or hit a breakpoint, but
5812 the user wanted this thread to be stopped, pretend we got a
5813 SIG0 (generic unsignaled stop). */
5814 if (ecs
->event_thread
->stop_requested
5815 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5816 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5818 ecs
->event_thread
->suspend
.stop_pc
5819 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5823 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5824 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5826 switch_to_thread (ecs
->event_thread
);
5828 infrun_log_debug ("stop_pc=%s",
5829 paddress (reg_gdbarch
,
5830 ecs
->event_thread
->suspend
.stop_pc
));
5831 if (target_stopped_by_watchpoint ())
5835 infrun_log_debug ("stopped by watchpoint");
5837 if (target_stopped_data_address (current_top_target (), &addr
))
5838 infrun_log_debug ("stopped data address=%s",
5839 paddress (reg_gdbarch
, addr
));
5841 infrun_log_debug ("(no data address available)");
5845 /* This is originated from start_remote(), start_inferior() and
5846 shared libraries hook functions. */
5847 stop_soon
= get_inferior_stop_soon (ecs
);
5848 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5850 context_switch (ecs
);
5851 infrun_log_debug ("quietly stopped");
5852 stop_print_frame
= 1;
5857 /* This originates from attach_command(). We need to overwrite
5858 the stop_signal here, because some kernels don't ignore a
5859 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5860 See more comments in inferior.h. On the other hand, if we
5861 get a non-SIGSTOP, report it to the user - assume the backend
5862 will handle the SIGSTOP if it should show up later.
5864 Also consider that the attach is complete when we see a
5865 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5866 target extended-remote report it instead of a SIGSTOP
5867 (e.g. gdbserver). We already rely on SIGTRAP being our
5868 signal, so this is no exception.
5870 Also consider that the attach is complete when we see a
5871 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5872 the target to stop all threads of the inferior, in case the
5873 low level attach operation doesn't stop them implicitly. If
5874 they weren't stopped implicitly, then the stub will report a
5875 GDB_SIGNAL_0, meaning: stopped for no particular reason
5876 other than GDB's request. */
5877 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5878 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5879 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5880 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5882 stop_print_frame
= 1;
5884 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5888 /* See if something interesting happened to the non-current thread. If
5889 so, then switch to that thread. */
5890 if (ecs
->ptid
!= inferior_ptid
)
5892 infrun_log_debug ("context switch");
5894 context_switch (ecs
);
5896 if (deprecated_context_hook
)
5897 deprecated_context_hook (ecs
->event_thread
->global_num
);
5900 /* At this point, get hold of the now-current thread's frame. */
5901 frame
= get_current_frame ();
5902 gdbarch
= get_frame_arch (frame
);
5904 /* Pull the single step breakpoints out of the target. */
5905 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5907 struct regcache
*regcache
;
5910 regcache
= get_thread_regcache (ecs
->event_thread
);
5911 const address_space
*aspace
= regcache
->aspace ();
5913 pc
= regcache_read_pc (regcache
);
5915 /* However, before doing so, if this single-step breakpoint was
5916 actually for another thread, set this thread up for moving
5918 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5921 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5923 infrun_log_debug ("[%s] hit another thread's single-step "
5925 target_pid_to_str (ecs
->ptid
).c_str ());
5926 ecs
->hit_singlestep_breakpoint
= 1;
5931 infrun_log_debug ("[%s] hit its single-step breakpoint",
5932 target_pid_to_str (ecs
->ptid
).c_str ());
5935 delete_just_stopped_threads_single_step_breakpoints ();
5937 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5938 && ecs
->event_thread
->control
.trap_expected
5939 && ecs
->event_thread
->stepping_over_watchpoint
)
5940 stopped_by_watchpoint
= 0;
5942 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5944 /* If necessary, step over this watchpoint. We'll be back to display
5946 if (stopped_by_watchpoint
5947 && (target_have_steppable_watchpoint
5948 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5950 /* At this point, we are stopped at an instruction which has
5951 attempted to write to a piece of memory under control of
5952 a watchpoint. The instruction hasn't actually executed
5953 yet. If we were to evaluate the watchpoint expression
5954 now, we would get the old value, and therefore no change
5955 would seem to have occurred.
5957 In order to make watchpoints work `right', we really need
5958 to complete the memory write, and then evaluate the
5959 watchpoint expression. We do this by single-stepping the
5962 It may not be necessary to disable the watchpoint to step over
5963 it. For example, the PA can (with some kernel cooperation)
5964 single step over a watchpoint without disabling the watchpoint.
5966 It is far more common to need to disable a watchpoint to step
5967 the inferior over it. If we have non-steppable watchpoints,
5968 we must disable the current watchpoint; it's simplest to
5969 disable all watchpoints.
5971 Any breakpoint at PC must also be stepped over -- if there's
5972 one, it will have already triggered before the watchpoint
5973 triggered, and we either already reported it to the user, or
5974 it didn't cause a stop and we called keep_going. In either
5975 case, if there was a breakpoint at PC, we must be trying to
5977 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5982 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5983 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5984 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5985 ecs
->event_thread
->control
.stop_step
= 0;
5986 stop_print_frame
= 1;
5987 stopped_by_random_signal
= 0;
5988 bpstat stop_chain
= NULL
;
5990 /* Hide inlined functions starting here, unless we just performed stepi or
5991 nexti. After stepi and nexti, always show the innermost frame (not any
5992 inline function call sites). */
5993 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5995 const address_space
*aspace
5996 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5998 /* skip_inline_frames is expensive, so we avoid it if we can
5999 determine that the address is one where functions cannot have
6000 been inlined. This improves performance with inferiors that
6001 load a lot of shared libraries, because the solib event
6002 breakpoint is defined as the address of a function (i.e. not
6003 inline). Note that we have to check the previous PC as well
6004 as the current one to catch cases when we have just
6005 single-stepped off a breakpoint prior to reinstating it.
6006 Note that we're assuming that the code we single-step to is
6007 not inline, but that's not definitive: there's nothing
6008 preventing the event breakpoint function from containing
6009 inlined code, and the single-step ending up there. If the
6010 user had set a breakpoint on that inlined code, the missing
6011 skip_inline_frames call would break things. Fortunately
6012 that's an extremely unlikely scenario. */
6013 if (!pc_at_non_inline_function (aspace
,
6014 ecs
->event_thread
->suspend
.stop_pc
,
6016 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6017 && ecs
->event_thread
->control
.trap_expected
6018 && pc_at_non_inline_function (aspace
,
6019 ecs
->event_thread
->prev_pc
,
6022 stop_chain
= build_bpstat_chain (aspace
,
6023 ecs
->event_thread
->suspend
.stop_pc
,
6025 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6027 /* Re-fetch current thread's frame in case that invalidated
6029 frame
= get_current_frame ();
6030 gdbarch
= get_frame_arch (frame
);
6034 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6035 && ecs
->event_thread
->control
.trap_expected
6036 && gdbarch_single_step_through_delay_p (gdbarch
)
6037 && currently_stepping (ecs
->event_thread
))
6039 /* We're trying to step off a breakpoint. Turns out that we're
6040 also on an instruction that needs to be stepped multiple
6041 times before it's been fully executing. E.g., architectures
6042 with a delay slot. It needs to be stepped twice, once for
6043 the instruction and once for the delay slot. */
6044 int step_through_delay
6045 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6047 if (step_through_delay
)
6048 infrun_log_debug ("step through delay");
6050 if (ecs
->event_thread
->control
.step_range_end
== 0
6051 && step_through_delay
)
6053 /* The user issued a continue when stopped at a breakpoint.
6054 Set up for another trap and get out of here. */
6055 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6059 else if (step_through_delay
)
6061 /* The user issued a step when stopped at a breakpoint.
6062 Maybe we should stop, maybe we should not - the delay
6063 slot *might* correspond to a line of source. In any
6064 case, don't decide that here, just set
6065 ecs->stepping_over_breakpoint, making sure we
6066 single-step again before breakpoints are re-inserted. */
6067 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6071 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6072 handles this event. */
6073 ecs
->event_thread
->control
.stop_bpstat
6074 = bpstat_stop_status (get_current_regcache ()->aspace (),
6075 ecs
->event_thread
->suspend
.stop_pc
,
6076 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6078 /* Following in case break condition called a
6080 stop_print_frame
= 1;
6082 /* This is where we handle "moribund" watchpoints. Unlike
6083 software breakpoints traps, hardware watchpoint traps are
6084 always distinguishable from random traps. If no high-level
6085 watchpoint is associated with the reported stop data address
6086 anymore, then the bpstat does not explain the signal ---
6087 simply make sure to ignore it if `stopped_by_watchpoint' is
6090 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6091 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6093 && stopped_by_watchpoint
)
6095 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6099 /* NOTE: cagney/2003-03-29: These checks for a random signal
6100 at one stage in the past included checks for an inferior
6101 function call's call dummy's return breakpoint. The original
6102 comment, that went with the test, read:
6104 ``End of a stack dummy. Some systems (e.g. Sony news) give
6105 another signal besides SIGTRAP, so check here as well as
6108 If someone ever tries to get call dummys on a
6109 non-executable stack to work (where the target would stop
6110 with something like a SIGSEGV), then those tests might need
6111 to be re-instated. Given, however, that the tests were only
6112 enabled when momentary breakpoints were not being used, I
6113 suspect that it won't be the case.
6115 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6116 be necessary for call dummies on a non-executable stack on
6119 /* See if the breakpoints module can explain the signal. */
6121 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6122 ecs
->event_thread
->suspend
.stop_signal
);
6124 /* Maybe this was a trap for a software breakpoint that has since
6126 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6128 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6129 ecs
->event_thread
->suspend
.stop_pc
))
6131 struct regcache
*regcache
;
6134 /* Re-adjust PC to what the program would see if GDB was not
6136 regcache
= get_thread_regcache (ecs
->event_thread
);
6137 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6140 gdb::optional
<scoped_restore_tmpl
<int>>
6141 restore_operation_disable
;
6143 if (record_full_is_used ())
6144 restore_operation_disable
.emplace
6145 (record_full_gdb_operation_disable_set ());
6147 regcache_write_pc (regcache
,
6148 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6153 /* A delayed software breakpoint event. Ignore the trap. */
6154 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6159 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6160 has since been removed. */
6161 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6163 /* A delayed hardware breakpoint event. Ignore the trap. */
6164 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6169 /* If not, perhaps stepping/nexting can. */
6171 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6172 && currently_stepping (ecs
->event_thread
));
6174 /* Perhaps the thread hit a single-step breakpoint of _another_
6175 thread. Single-step breakpoints are transparent to the
6176 breakpoints module. */
6178 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6180 /* No? Perhaps we got a moribund watchpoint. */
6182 random_signal
= !stopped_by_watchpoint
;
6184 /* Always stop if the user explicitly requested this thread to
6186 if (ecs
->event_thread
->stop_requested
)
6189 infrun_log_debug ("user-requested stop");
6192 /* For the program's own signals, act according to
6193 the signal handling tables. */
6197 /* Signal not for debugging purposes. */
6198 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6199 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6201 infrun_log_debug ("random signal (%s)",
6202 gdb_signal_to_symbol_string (stop_signal
));
6204 stopped_by_random_signal
= 1;
6206 /* Always stop on signals if we're either just gaining control
6207 of the program, or the user explicitly requested this thread
6208 to remain stopped. */
6209 if (stop_soon
!= NO_STOP_QUIETLY
6210 || ecs
->event_thread
->stop_requested
6212 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6218 /* Notify observers the signal has "handle print" set. Note we
6219 returned early above if stopping; normal_stop handles the
6220 printing in that case. */
6221 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6223 /* The signal table tells us to print about this signal. */
6224 target_terminal::ours_for_output ();
6225 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6226 target_terminal::inferior ();
6229 /* Clear the signal if it should not be passed. */
6230 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6231 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6233 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6234 && ecs
->event_thread
->control
.trap_expected
6235 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6237 /* We were just starting a new sequence, attempting to
6238 single-step off of a breakpoint and expecting a SIGTRAP.
6239 Instead this signal arrives. This signal will take us out
6240 of the stepping range so GDB needs to remember to, when
6241 the signal handler returns, resume stepping off that
6243 /* To simplify things, "continue" is forced to use the same
6244 code paths as single-step - set a breakpoint at the
6245 signal return address and then, once hit, step off that
6247 infrun_log_debug ("signal arrived while stepping over breakpoint");
6249 insert_hp_step_resume_breakpoint_at_frame (frame
);
6250 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6251 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6252 ecs
->event_thread
->control
.trap_expected
= 0;
6254 /* If we were nexting/stepping some other thread, switch to
6255 it, so that we don't continue it, losing control. */
6256 if (!switch_back_to_stepped_thread (ecs
))
6261 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6262 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6264 || ecs
->event_thread
->control
.step_range_end
== 1)
6265 && frame_id_eq (get_stack_frame_id (frame
),
6266 ecs
->event_thread
->control
.step_stack_frame_id
)
6267 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6269 /* The inferior is about to take a signal that will take it
6270 out of the single step range. Set a breakpoint at the
6271 current PC (which is presumably where the signal handler
6272 will eventually return) and then allow the inferior to
6275 Note that this is only needed for a signal delivered
6276 while in the single-step range. Nested signals aren't a
6277 problem as they eventually all return. */
6278 infrun_log_debug ("signal may take us out of single-step range");
6280 clear_step_over_info ();
6281 insert_hp_step_resume_breakpoint_at_frame (frame
);
6282 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6283 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6284 ecs
->event_thread
->control
.trap_expected
= 0;
6289 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6290 when either there's a nested signal, or when there's a
6291 pending signal enabled just as the signal handler returns
6292 (leaving the inferior at the step-resume-breakpoint without
6293 actually executing it). Either way continue until the
6294 breakpoint is really hit. */
6296 if (!switch_back_to_stepped_thread (ecs
))
6298 infrun_log_debug ("random signal, keep going");
6305 process_event_stop_test (ecs
);
6308 /* Come here when we've got some debug event / signal we can explain
6309 (IOW, not a random signal), and test whether it should cause a
6310 stop, or whether we should resume the inferior (transparently).
6311 E.g., could be a breakpoint whose condition evaluates false; we
6312 could be still stepping within the line; etc. */
6315 process_event_stop_test (struct execution_control_state
*ecs
)
6317 struct symtab_and_line stop_pc_sal
;
6318 struct frame_info
*frame
;
6319 struct gdbarch
*gdbarch
;
6320 CORE_ADDR jmp_buf_pc
;
6321 struct bpstat_what what
;
6323 /* Handle cases caused by hitting a breakpoint. */
6325 frame
= get_current_frame ();
6326 gdbarch
= get_frame_arch (frame
);
6328 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6330 if (what
.call_dummy
)
6332 stop_stack_dummy
= what
.call_dummy
;
6335 /* A few breakpoint types have callbacks associated (e.g.,
6336 bp_jit_event). Run them now. */
6337 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6339 /* If we hit an internal event that triggers symbol changes, the
6340 current frame will be invalidated within bpstat_what (e.g., if we
6341 hit an internal solib event). Re-fetch it. */
6342 frame
= get_current_frame ();
6343 gdbarch
= get_frame_arch (frame
);
6345 switch (what
.main_action
)
6347 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6348 /* If we hit the breakpoint at longjmp while stepping, we
6349 install a momentary breakpoint at the target of the
6352 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6354 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6356 if (what
.is_longjmp
)
6358 struct value
*arg_value
;
6360 /* If we set the longjmp breakpoint via a SystemTap probe,
6361 then use it to extract the arguments. The destination PC
6362 is the third argument to the probe. */
6363 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6366 jmp_buf_pc
= value_as_address (arg_value
);
6367 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6369 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6370 || !gdbarch_get_longjmp_target (gdbarch
,
6371 frame
, &jmp_buf_pc
))
6373 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6374 "(!gdbarch_get_longjmp_target)");
6379 /* Insert a breakpoint at resume address. */
6380 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6383 check_exception_resume (ecs
, frame
);
6387 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6389 struct frame_info
*init_frame
;
6391 /* There are several cases to consider.
6393 1. The initiating frame no longer exists. In this case we
6394 must stop, because the exception or longjmp has gone too
6397 2. The initiating frame exists, and is the same as the
6398 current frame. We stop, because the exception or longjmp
6401 3. The initiating frame exists and is different from the
6402 current frame. This means the exception or longjmp has
6403 been caught beneath the initiating frame, so keep going.
6405 4. longjmp breakpoint has been placed just to protect
6406 against stale dummy frames and user is not interested in
6407 stopping around longjmps. */
6409 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6411 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6413 delete_exception_resume_breakpoint (ecs
->event_thread
);
6415 if (what
.is_longjmp
)
6417 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6419 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6427 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6431 struct frame_id current_id
6432 = get_frame_id (get_current_frame ());
6433 if (frame_id_eq (current_id
,
6434 ecs
->event_thread
->initiating_frame
))
6436 /* Case 2. Fall through. */
6446 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6448 delete_step_resume_breakpoint (ecs
->event_thread
);
6450 end_stepping_range (ecs
);
6454 case BPSTAT_WHAT_SINGLE
:
6455 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6456 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6457 /* Still need to check other stuff, at least the case where we
6458 are stepping and step out of the right range. */
6461 case BPSTAT_WHAT_STEP_RESUME
:
6462 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6464 delete_step_resume_breakpoint (ecs
->event_thread
);
6465 if (ecs
->event_thread
->control
.proceed_to_finish
6466 && execution_direction
== EXEC_REVERSE
)
6468 struct thread_info
*tp
= ecs
->event_thread
;
6470 /* We are finishing a function in reverse, and just hit the
6471 step-resume breakpoint at the start address of the
6472 function, and we're almost there -- just need to back up
6473 by one more single-step, which should take us back to the
6475 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6479 fill_in_stop_func (gdbarch
, ecs
);
6480 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6481 && execution_direction
== EXEC_REVERSE
)
6483 /* We are stepping over a function call in reverse, and just
6484 hit the step-resume breakpoint at the start address of
6485 the function. Go back to single-stepping, which should
6486 take us back to the function call. */
6487 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6493 case BPSTAT_WHAT_STOP_NOISY
:
6494 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6495 stop_print_frame
= 1;
6497 /* Assume the thread stopped for a breapoint. We'll still check
6498 whether a/the breakpoint is there when the thread is next
6500 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6505 case BPSTAT_WHAT_STOP_SILENT
:
6506 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6507 stop_print_frame
= 0;
6509 /* Assume the thread stopped for a breapoint. We'll still check
6510 whether a/the breakpoint is there when the thread is next
6512 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6516 case BPSTAT_WHAT_HP_STEP_RESUME
:
6517 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6519 delete_step_resume_breakpoint (ecs
->event_thread
);
6520 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6522 /* Back when the step-resume breakpoint was inserted, we
6523 were trying to single-step off a breakpoint. Go back to
6525 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6526 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6532 case BPSTAT_WHAT_KEEP_CHECKING
:
6536 /* If we stepped a permanent breakpoint and we had a high priority
6537 step-resume breakpoint for the address we stepped, but we didn't
6538 hit it, then we must have stepped into the signal handler. The
6539 step-resume was only necessary to catch the case of _not_
6540 stepping into the handler, so delete it, and fall through to
6541 checking whether the step finished. */
6542 if (ecs
->event_thread
->stepped_breakpoint
)
6544 struct breakpoint
*sr_bp
6545 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6548 && sr_bp
->loc
->permanent
6549 && sr_bp
->type
== bp_hp_step_resume
6550 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6552 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6553 delete_step_resume_breakpoint (ecs
->event_thread
);
6554 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6558 /* We come here if we hit a breakpoint but should not stop for it.
6559 Possibly we also were stepping and should stop for that. So fall
6560 through and test for stepping. But, if not stepping, do not
6563 /* In all-stop mode, if we're currently stepping but have stopped in
6564 some other thread, we need to switch back to the stepped thread. */
6565 if (switch_back_to_stepped_thread (ecs
))
6568 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6570 infrun_log_debug ("step-resume breakpoint is inserted");
6572 /* Having a step-resume breakpoint overrides anything
6573 else having to do with stepping commands until
6574 that breakpoint is reached. */
6579 if (ecs
->event_thread
->control
.step_range_end
== 0)
6581 infrun_log_debug ("no stepping, continue");
6582 /* Likewise if we aren't even stepping. */
6587 /* Re-fetch current thread's frame in case the code above caused
6588 the frame cache to be re-initialized, making our FRAME variable
6589 a dangling pointer. */
6590 frame
= get_current_frame ();
6591 gdbarch
= get_frame_arch (frame
);
6592 fill_in_stop_func (gdbarch
, ecs
);
6594 /* If stepping through a line, keep going if still within it.
6596 Note that step_range_end is the address of the first instruction
6597 beyond the step range, and NOT the address of the last instruction
6600 Note also that during reverse execution, we may be stepping
6601 through a function epilogue and therefore must detect when
6602 the current-frame changes in the middle of a line. */
6604 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6606 && (execution_direction
!= EXEC_REVERSE
6607 || frame_id_eq (get_frame_id (frame
),
6608 ecs
->event_thread
->control
.step_frame_id
)))
6611 ("stepping inside range [%s-%s]",
6612 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6613 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6615 /* Tentatively re-enable range stepping; `resume' disables it if
6616 necessary (e.g., if we're stepping over a breakpoint or we
6617 have software watchpoints). */
6618 ecs
->event_thread
->control
.may_range_step
= 1;
6620 /* When stepping backward, stop at beginning of line range
6621 (unless it's the function entry point, in which case
6622 keep going back to the call point). */
6623 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6624 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6625 && stop_pc
!= ecs
->stop_func_start
6626 && execution_direction
== EXEC_REVERSE
)
6627 end_stepping_range (ecs
);
6634 /* We stepped out of the stepping range. */
6636 /* If we are stepping at the source level and entered the runtime
6637 loader dynamic symbol resolution code...
6639 EXEC_FORWARD: we keep on single stepping until we exit the run
6640 time loader code and reach the callee's address.
6642 EXEC_REVERSE: we've already executed the callee (backward), and
6643 the runtime loader code is handled just like any other
6644 undebuggable function call. Now we need only keep stepping
6645 backward through the trampoline code, and that's handled further
6646 down, so there is nothing for us to do here. */
6648 if (execution_direction
!= EXEC_REVERSE
6649 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6650 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6652 CORE_ADDR pc_after_resolver
=
6653 gdbarch_skip_solib_resolver (gdbarch
,
6654 ecs
->event_thread
->suspend
.stop_pc
);
6656 infrun_log_debug ("stepped into dynsym resolve code");
6658 if (pc_after_resolver
)
6660 /* Set up a step-resume breakpoint at the address
6661 indicated by SKIP_SOLIB_RESOLVER. */
6662 symtab_and_line sr_sal
;
6663 sr_sal
.pc
= pc_after_resolver
;
6664 sr_sal
.pspace
= get_frame_program_space (frame
);
6666 insert_step_resume_breakpoint_at_sal (gdbarch
,
6667 sr_sal
, null_frame_id
);
6674 /* Step through an indirect branch thunk. */
6675 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6676 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6677 ecs
->event_thread
->suspend
.stop_pc
))
6679 infrun_log_debug ("stepped into indirect branch thunk");
6684 if (ecs
->event_thread
->control
.step_range_end
!= 1
6685 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6686 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6687 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6689 infrun_log_debug ("stepped into signal trampoline");
6690 /* The inferior, while doing a "step" or "next", has ended up in
6691 a signal trampoline (either by a signal being delivered or by
6692 the signal handler returning). Just single-step until the
6693 inferior leaves the trampoline (either by calling the handler
6699 /* If we're in the return path from a shared library trampoline,
6700 we want to proceed through the trampoline when stepping. */
6701 /* macro/2012-04-25: This needs to come before the subroutine
6702 call check below as on some targets return trampolines look
6703 like subroutine calls (MIPS16 return thunks). */
6704 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6705 ecs
->event_thread
->suspend
.stop_pc
,
6706 ecs
->stop_func_name
)
6707 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6709 /* Determine where this trampoline returns. */
6710 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6711 CORE_ADDR real_stop_pc
6712 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6714 infrun_log_debug ("stepped into solib return tramp");
6716 /* Only proceed through if we know where it's going. */
6719 /* And put the step-breakpoint there and go until there. */
6720 symtab_and_line sr_sal
;
6721 sr_sal
.pc
= real_stop_pc
;
6722 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6723 sr_sal
.pspace
= get_frame_program_space (frame
);
6725 /* Do not specify what the fp should be when we stop since
6726 on some machines the prologue is where the new fp value
6728 insert_step_resume_breakpoint_at_sal (gdbarch
,
6729 sr_sal
, null_frame_id
);
6731 /* Restart without fiddling with the step ranges or
6738 /* Check for subroutine calls. The check for the current frame
6739 equalling the step ID is not necessary - the check of the
6740 previous frame's ID is sufficient - but it is a common case and
6741 cheaper than checking the previous frame's ID.
6743 NOTE: frame_id_eq will never report two invalid frame IDs as
6744 being equal, so to get into this block, both the current and
6745 previous frame must have valid frame IDs. */
6746 /* The outer_frame_id check is a heuristic to detect stepping
6747 through startup code. If we step over an instruction which
6748 sets the stack pointer from an invalid value to a valid value,
6749 we may detect that as a subroutine call from the mythical
6750 "outermost" function. This could be fixed by marking
6751 outermost frames as !stack_p,code_p,special_p. Then the
6752 initial outermost frame, before sp was valid, would
6753 have code_addr == &_start. See the comment in frame_id_eq
6755 if (!frame_id_eq (get_stack_frame_id (frame
),
6756 ecs
->event_thread
->control
.step_stack_frame_id
)
6757 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6758 ecs
->event_thread
->control
.step_stack_frame_id
)
6759 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6761 || (ecs
->event_thread
->control
.step_start_function
6762 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6764 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6765 CORE_ADDR real_stop_pc
;
6767 infrun_log_debug ("stepped into subroutine");
6769 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6771 /* I presume that step_over_calls is only 0 when we're
6772 supposed to be stepping at the assembly language level
6773 ("stepi"). Just stop. */
6774 /* And this works the same backward as frontward. MVS */
6775 end_stepping_range (ecs
);
6779 /* Reverse stepping through solib trampolines. */
6781 if (execution_direction
== EXEC_REVERSE
6782 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6783 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6784 || (ecs
->stop_func_start
== 0
6785 && in_solib_dynsym_resolve_code (stop_pc
))))
6787 /* Any solib trampoline code can be handled in reverse
6788 by simply continuing to single-step. We have already
6789 executed the solib function (backwards), and a few
6790 steps will take us back through the trampoline to the
6796 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6798 /* We're doing a "next".
6800 Normal (forward) execution: set a breakpoint at the
6801 callee's return address (the address at which the caller
6804 Reverse (backward) execution. set the step-resume
6805 breakpoint at the start of the function that we just
6806 stepped into (backwards), and continue to there. When we
6807 get there, we'll need to single-step back to the caller. */
6809 if (execution_direction
== EXEC_REVERSE
)
6811 /* If we're already at the start of the function, we've either
6812 just stepped backward into a single instruction function,
6813 or stepped back out of a signal handler to the first instruction
6814 of the function. Just keep going, which will single-step back
6816 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6818 /* Normal function call return (static or dynamic). */
6819 symtab_and_line sr_sal
;
6820 sr_sal
.pc
= ecs
->stop_func_start
;
6821 sr_sal
.pspace
= get_frame_program_space (frame
);
6822 insert_step_resume_breakpoint_at_sal (gdbarch
,
6823 sr_sal
, null_frame_id
);
6827 insert_step_resume_breakpoint_at_caller (frame
);
6833 /* If we are in a function call trampoline (a stub between the
6834 calling routine and the real function), locate the real
6835 function. That's what tells us (a) whether we want to step
6836 into it at all, and (b) what prologue we want to run to the
6837 end of, if we do step into it. */
6838 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6839 if (real_stop_pc
== 0)
6840 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6841 if (real_stop_pc
!= 0)
6842 ecs
->stop_func_start
= real_stop_pc
;
6844 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6846 symtab_and_line sr_sal
;
6847 sr_sal
.pc
= ecs
->stop_func_start
;
6848 sr_sal
.pspace
= get_frame_program_space (frame
);
6850 insert_step_resume_breakpoint_at_sal (gdbarch
,
6851 sr_sal
, null_frame_id
);
6856 /* If we have line number information for the function we are
6857 thinking of stepping into and the function isn't on the skip
6860 If there are several symtabs at that PC (e.g. with include
6861 files), just want to know whether *any* of them have line
6862 numbers. find_pc_line handles this. */
6864 struct symtab_and_line tmp_sal
;
6866 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6867 if (tmp_sal
.line
!= 0
6868 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6870 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6872 if (execution_direction
== EXEC_REVERSE
)
6873 handle_step_into_function_backward (gdbarch
, ecs
);
6875 handle_step_into_function (gdbarch
, ecs
);
6880 /* If we have no line number and the step-stop-if-no-debug is
6881 set, we stop the step so that the user has a chance to switch
6882 in assembly mode. */
6883 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6884 && step_stop_if_no_debug
)
6886 end_stepping_range (ecs
);
6890 if (execution_direction
== EXEC_REVERSE
)
6892 /* If we're already at the start of the function, we've either just
6893 stepped backward into a single instruction function without line
6894 number info, or stepped back out of a signal handler to the first
6895 instruction of the function without line number info. Just keep
6896 going, which will single-step back to the caller. */
6897 if (ecs
->stop_func_start
!= stop_pc
)
6899 /* Set a breakpoint at callee's start address.
6900 From there we can step once and be back in the caller. */
6901 symtab_and_line sr_sal
;
6902 sr_sal
.pc
= ecs
->stop_func_start
;
6903 sr_sal
.pspace
= get_frame_program_space (frame
);
6904 insert_step_resume_breakpoint_at_sal (gdbarch
,
6905 sr_sal
, null_frame_id
);
6909 /* Set a breakpoint at callee's return address (the address
6910 at which the caller will resume). */
6911 insert_step_resume_breakpoint_at_caller (frame
);
6917 /* Reverse stepping through solib trampolines. */
6919 if (execution_direction
== EXEC_REVERSE
6920 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6922 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6924 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6925 || (ecs
->stop_func_start
== 0
6926 && in_solib_dynsym_resolve_code (stop_pc
)))
6928 /* Any solib trampoline code can be handled in reverse
6929 by simply continuing to single-step. We have already
6930 executed the solib function (backwards), and a few
6931 steps will take us back through the trampoline to the
6936 else if (in_solib_dynsym_resolve_code (stop_pc
))
6938 /* Stepped backward into the solib dynsym resolver.
6939 Set a breakpoint at its start and continue, then
6940 one more step will take us out. */
6941 symtab_and_line sr_sal
;
6942 sr_sal
.pc
= ecs
->stop_func_start
;
6943 sr_sal
.pspace
= get_frame_program_space (frame
);
6944 insert_step_resume_breakpoint_at_sal (gdbarch
,
6945 sr_sal
, null_frame_id
);
6951 /* This always returns the sal for the inner-most frame when we are in a
6952 stack of inlined frames, even if GDB actually believes that it is in a
6953 more outer frame. This is checked for below by calls to
6954 inline_skipped_frames. */
6955 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6957 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6958 the trampoline processing logic, however, there are some trampolines
6959 that have no names, so we should do trampoline handling first. */
6960 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6961 && ecs
->stop_func_name
== NULL
6962 && stop_pc_sal
.line
== 0)
6964 infrun_log_debug ("stepped into undebuggable function");
6966 /* The inferior just stepped into, or returned to, an
6967 undebuggable function (where there is no debugging information
6968 and no line number corresponding to the address where the
6969 inferior stopped). Since we want to skip this kind of code,
6970 we keep going until the inferior returns from this
6971 function - unless the user has asked us not to (via
6972 set step-mode) or we no longer know how to get back
6973 to the call site. */
6974 if (step_stop_if_no_debug
6975 || !frame_id_p (frame_unwind_caller_id (frame
)))
6977 /* If we have no line number and the step-stop-if-no-debug
6978 is set, we stop the step so that the user has a chance to
6979 switch in assembly mode. */
6980 end_stepping_range (ecs
);
6985 /* Set a breakpoint at callee's return address (the address
6986 at which the caller will resume). */
6987 insert_step_resume_breakpoint_at_caller (frame
);
6993 if (ecs
->event_thread
->control
.step_range_end
== 1)
6995 /* It is stepi or nexti. We always want to stop stepping after
6997 infrun_log_debug ("stepi/nexti");
6998 end_stepping_range (ecs
);
7002 if (stop_pc_sal
.line
== 0)
7004 /* We have no line number information. That means to stop
7005 stepping (does this always happen right after one instruction,
7006 when we do "s" in a function with no line numbers,
7007 or can this happen as a result of a return or longjmp?). */
7008 infrun_log_debug ("line number info");
7009 end_stepping_range (ecs
);
7013 /* Look for "calls" to inlined functions, part one. If the inline
7014 frame machinery detected some skipped call sites, we have entered
7015 a new inline function. */
7017 if (frame_id_eq (get_frame_id (get_current_frame ()),
7018 ecs
->event_thread
->control
.step_frame_id
)
7019 && inline_skipped_frames (ecs
->event_thread
))
7021 infrun_log_debug ("stepped into inlined function");
7023 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7025 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7027 /* For "step", we're going to stop. But if the call site
7028 for this inlined function is on the same source line as
7029 we were previously stepping, go down into the function
7030 first. Otherwise stop at the call site. */
7032 if (call_sal
.line
== ecs
->event_thread
->current_line
7033 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7035 step_into_inline_frame (ecs
->event_thread
);
7036 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7043 end_stepping_range (ecs
);
7048 /* For "next", we should stop at the call site if it is on a
7049 different source line. Otherwise continue through the
7050 inlined function. */
7051 if (call_sal
.line
== ecs
->event_thread
->current_line
7052 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7055 end_stepping_range (ecs
);
7060 /* Look for "calls" to inlined functions, part two. If we are still
7061 in the same real function we were stepping through, but we have
7062 to go further up to find the exact frame ID, we are stepping
7063 through a more inlined call beyond its call site. */
7065 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7066 && !frame_id_eq (get_frame_id (get_current_frame ()),
7067 ecs
->event_thread
->control
.step_frame_id
)
7068 && stepped_in_from (get_current_frame (),
7069 ecs
->event_thread
->control
.step_frame_id
))
7071 infrun_log_debug ("stepping through inlined function");
7073 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7074 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7077 end_stepping_range (ecs
);
7081 bool refresh_step_info
= true;
7082 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7083 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7084 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7086 if (stop_pc_sal
.is_stmt
)
7088 /* We are at the start of a different line. So stop. Note that
7089 we don't stop if we step into the middle of a different line.
7090 That is said to make things like for (;;) statements work
7092 infrun_log_debug ("infrun: stepped to a different line\n");
7093 end_stepping_range (ecs
);
7096 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7097 ecs
->event_thread
->control
.step_frame_id
))
7099 /* We are at the start of a different line, however, this line is
7100 not marked as a statement, and we have not changed frame. We
7101 ignore this line table entry, and continue stepping forward,
7102 looking for a better place to stop. */
7103 refresh_step_info
= false;
7104 infrun_log_debug ("infrun: stepped to a different line, but "
7105 "it's not the start of a statement\n");
7109 /* We aren't done stepping.
7111 Optimize by setting the stepping range to the line.
7112 (We might not be in the original line, but if we entered a
7113 new line in mid-statement, we continue stepping. This makes
7114 things like for(;;) statements work better.)
7116 If we entered a SAL that indicates a non-statement line table entry,
7117 then we update the stepping range, but we don't update the step info,
7118 which includes things like the line number we are stepping away from.
7119 This means we will stop when we find a line table entry that is marked
7120 as is-statement, even if it matches the non-statement one we just
7123 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7124 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7125 ecs
->event_thread
->control
.may_range_step
= 1;
7126 if (refresh_step_info
)
7127 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7129 infrun_log_debug ("keep going");
7133 /* In all-stop mode, if we're currently stepping but have stopped in
7134 some other thread, we may need to switch back to the stepped
7135 thread. Returns true we set the inferior running, false if we left
7136 it stopped (and the event needs further processing). */
7139 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7141 if (!target_is_non_stop_p ())
7143 struct thread_info
*stepping_thread
;
7145 /* If any thread is blocked on some internal breakpoint, and we
7146 simply need to step over that breakpoint to get it going
7147 again, do that first. */
7149 /* However, if we see an event for the stepping thread, then we
7150 know all other threads have been moved past their breakpoints
7151 already. Let the caller check whether the step is finished,
7152 etc., before deciding to move it past a breakpoint. */
7153 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7156 /* Check if the current thread is blocked on an incomplete
7157 step-over, interrupted by a random signal. */
7158 if (ecs
->event_thread
->control
.trap_expected
7159 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7161 infrun_log_debug ("need to finish step-over of [%s]",
7162 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7167 /* Check if the current thread is blocked by a single-step
7168 breakpoint of another thread. */
7169 if (ecs
->hit_singlestep_breakpoint
)
7171 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7172 target_pid_to_str (ecs
->ptid
).c_str ());
7177 /* If this thread needs yet another step-over (e.g., stepping
7178 through a delay slot), do it first before moving on to
7180 if (thread_still_needs_step_over (ecs
->event_thread
))
7183 ("thread [%s] still needs step-over",
7184 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7189 /* If scheduler locking applies even if not stepping, there's no
7190 need to walk over threads. Above we've checked whether the
7191 current thread is stepping. If some other thread not the
7192 event thread is stepping, then it must be that scheduler
7193 locking is not in effect. */
7194 if (schedlock_applies (ecs
->event_thread
))
7197 /* Otherwise, we no longer expect a trap in the current thread.
7198 Clear the trap_expected flag before switching back -- this is
7199 what keep_going does as well, if we call it. */
7200 ecs
->event_thread
->control
.trap_expected
= 0;
7202 /* Likewise, clear the signal if it should not be passed. */
7203 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7204 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7206 /* Do all pending step-overs before actually proceeding with
7208 if (start_step_over ())
7210 prepare_to_wait (ecs
);
7214 /* Look for the stepping/nexting thread. */
7215 stepping_thread
= NULL
;
7217 for (thread_info
*tp
: all_non_exited_threads ())
7219 switch_to_thread_no_regs (tp
);
7221 /* Ignore threads of processes the caller is not
7224 && (tp
->inf
->process_target () != ecs
->target
7225 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7228 /* When stepping over a breakpoint, we lock all threads
7229 except the one that needs to move past the breakpoint.
7230 If a non-event thread has this set, the "incomplete
7231 step-over" check above should have caught it earlier. */
7232 if (tp
->control
.trap_expected
)
7234 internal_error (__FILE__
, __LINE__
,
7235 "[%s] has inconsistent state: "
7236 "trap_expected=%d\n",
7237 target_pid_to_str (tp
->ptid
).c_str (),
7238 tp
->control
.trap_expected
);
7241 /* Did we find the stepping thread? */
7242 if (tp
->control
.step_range_end
)
7244 /* Yep. There should only one though. */
7245 gdb_assert (stepping_thread
== NULL
);
7247 /* The event thread is handled at the top, before we
7249 gdb_assert (tp
!= ecs
->event_thread
);
7251 /* If some thread other than the event thread is
7252 stepping, then scheduler locking can't be in effect,
7253 otherwise we wouldn't have resumed the current event
7254 thread in the first place. */
7255 gdb_assert (!schedlock_applies (tp
));
7257 stepping_thread
= tp
;
7261 if (stepping_thread
!= NULL
)
7263 infrun_log_debug ("switching back to stepped thread");
7265 if (keep_going_stepped_thread (stepping_thread
))
7267 prepare_to_wait (ecs
);
7272 switch_to_thread (ecs
->event_thread
);
7278 /* Set a previously stepped thread back to stepping. Returns true on
7279 success, false if the resume is not possible (e.g., the thread
7283 keep_going_stepped_thread (struct thread_info
*tp
)
7285 struct frame_info
*frame
;
7286 struct execution_control_state ecss
;
7287 struct execution_control_state
*ecs
= &ecss
;
7289 /* If the stepping thread exited, then don't try to switch back and
7290 resume it, which could fail in several different ways depending
7291 on the target. Instead, just keep going.
7293 We can find a stepping dead thread in the thread list in two
7296 - The target supports thread exit events, and when the target
7297 tries to delete the thread from the thread list, inferior_ptid
7298 pointed at the exiting thread. In such case, calling
7299 delete_thread does not really remove the thread from the list;
7300 instead, the thread is left listed, with 'exited' state.
7302 - The target's debug interface does not support thread exit
7303 events, and so we have no idea whatsoever if the previously
7304 stepping thread is still alive. For that reason, we need to
7305 synchronously query the target now. */
7307 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7309 infrun_log_debug ("not resuming previously stepped thread, it has "
7316 infrun_log_debug ("resuming previously stepped thread");
7318 reset_ecs (ecs
, tp
);
7319 switch_to_thread (tp
);
7321 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7322 frame
= get_current_frame ();
7324 /* If the PC of the thread we were trying to single-step has
7325 changed, then that thread has trapped or been signaled, but the
7326 event has not been reported to GDB yet. Re-poll the target
7327 looking for this particular thread's event (i.e. temporarily
7328 enable schedlock) by:
7330 - setting a break at the current PC
7331 - resuming that particular thread, only (by setting trap
7334 This prevents us continuously moving the single-step breakpoint
7335 forward, one instruction at a time, overstepping. */
7337 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7341 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7342 paddress (target_gdbarch (), tp
->prev_pc
),
7343 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7345 /* Clear the info of the previous step-over, as it's no longer
7346 valid (if the thread was trying to step over a breakpoint, it
7347 has already succeeded). It's what keep_going would do too,
7348 if we called it. Do this before trying to insert the sss
7349 breakpoint, otherwise if we were previously trying to step
7350 over this exact address in another thread, the breakpoint is
7352 clear_step_over_info ();
7353 tp
->control
.trap_expected
= 0;
7355 insert_single_step_breakpoint (get_frame_arch (frame
),
7356 get_frame_address_space (frame
),
7357 tp
->suspend
.stop_pc
);
7360 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7361 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7365 infrun_log_debug ("expected thread still hasn't advanced");
7367 keep_going_pass_signal (ecs
);
7372 /* Is thread TP in the middle of (software or hardware)
7373 single-stepping? (Note the result of this function must never be
7374 passed directly as target_resume's STEP parameter.) */
7377 currently_stepping (struct thread_info
*tp
)
7379 return ((tp
->control
.step_range_end
7380 && tp
->control
.step_resume_breakpoint
== NULL
)
7381 || tp
->control
.trap_expected
7382 || tp
->stepped_breakpoint
7383 || bpstat_should_step ());
7386 /* Inferior has stepped into a subroutine call with source code that
7387 we should not step over. Do step to the first line of code in
7391 handle_step_into_function (struct gdbarch
*gdbarch
,
7392 struct execution_control_state
*ecs
)
7394 fill_in_stop_func (gdbarch
, ecs
);
7396 compunit_symtab
*cust
7397 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7398 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7399 ecs
->stop_func_start
7400 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7402 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7403 /* Use the step_resume_break to step until the end of the prologue,
7404 even if that involves jumps (as it seems to on the vax under
7406 /* If the prologue ends in the middle of a source line, continue to
7407 the end of that source line (if it is still within the function).
7408 Otherwise, just go to end of prologue. */
7409 if (stop_func_sal
.end
7410 && stop_func_sal
.pc
!= ecs
->stop_func_start
7411 && stop_func_sal
.end
< ecs
->stop_func_end
)
7412 ecs
->stop_func_start
= stop_func_sal
.end
;
7414 /* Architectures which require breakpoint adjustment might not be able
7415 to place a breakpoint at the computed address. If so, the test
7416 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7417 ecs->stop_func_start to an address at which a breakpoint may be
7418 legitimately placed.
7420 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7421 made, GDB will enter an infinite loop when stepping through
7422 optimized code consisting of VLIW instructions which contain
7423 subinstructions corresponding to different source lines. On
7424 FR-V, it's not permitted to place a breakpoint on any but the
7425 first subinstruction of a VLIW instruction. When a breakpoint is
7426 set, GDB will adjust the breakpoint address to the beginning of
7427 the VLIW instruction. Thus, we need to make the corresponding
7428 adjustment here when computing the stop address. */
7430 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7432 ecs
->stop_func_start
7433 = gdbarch_adjust_breakpoint_address (gdbarch
,
7434 ecs
->stop_func_start
);
7437 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7439 /* We are already there: stop now. */
7440 end_stepping_range (ecs
);
7445 /* Put the step-breakpoint there and go until there. */
7446 symtab_and_line sr_sal
;
7447 sr_sal
.pc
= ecs
->stop_func_start
;
7448 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7449 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7451 /* Do not specify what the fp should be when we stop since on
7452 some machines the prologue is where the new fp value is
7454 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7456 /* And make sure stepping stops right away then. */
7457 ecs
->event_thread
->control
.step_range_end
7458 = ecs
->event_thread
->control
.step_range_start
;
7463 /* Inferior has stepped backward into a subroutine call with source
7464 code that we should not step over. Do step to the beginning of the
7465 last line of code in it. */
7468 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7469 struct execution_control_state
*ecs
)
7471 struct compunit_symtab
*cust
;
7472 struct symtab_and_line stop_func_sal
;
7474 fill_in_stop_func (gdbarch
, ecs
);
7476 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7477 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7478 ecs
->stop_func_start
7479 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7481 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7483 /* OK, we're just going to keep stepping here. */
7484 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7486 /* We're there already. Just stop stepping now. */
7487 end_stepping_range (ecs
);
7491 /* Else just reset the step range and keep going.
7492 No step-resume breakpoint, they don't work for
7493 epilogues, which can have multiple entry paths. */
7494 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7495 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7501 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7502 This is used to both functions and to skip over code. */
7505 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7506 struct symtab_and_line sr_sal
,
7507 struct frame_id sr_id
,
7508 enum bptype sr_type
)
7510 /* There should never be more than one step-resume or longjmp-resume
7511 breakpoint per thread, so we should never be setting a new
7512 step_resume_breakpoint when one is already active. */
7513 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7514 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7516 infrun_log_debug ("inserting step-resume breakpoint at %s",
7517 paddress (gdbarch
, sr_sal
.pc
));
7519 inferior_thread ()->control
.step_resume_breakpoint
7520 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7524 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7525 struct symtab_and_line sr_sal
,
7526 struct frame_id sr_id
)
7528 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7533 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7534 This is used to skip a potential signal handler.
7536 This is called with the interrupted function's frame. The signal
7537 handler, when it returns, will resume the interrupted function at
7541 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7543 gdb_assert (return_frame
!= NULL
);
7545 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7547 symtab_and_line sr_sal
;
7548 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7549 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7550 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7552 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7553 get_stack_frame_id (return_frame
),
7557 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7558 is used to skip a function after stepping into it (for "next" or if
7559 the called function has no debugging information).
7561 The current function has almost always been reached by single
7562 stepping a call or return instruction. NEXT_FRAME belongs to the
7563 current function, and the breakpoint will be set at the caller's
7566 This is a separate function rather than reusing
7567 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7568 get_prev_frame, which may stop prematurely (see the implementation
7569 of frame_unwind_caller_id for an example). */
7572 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7574 /* We shouldn't have gotten here if we don't know where the call site
7576 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7578 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7580 symtab_and_line sr_sal
;
7581 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7582 frame_unwind_caller_pc (next_frame
));
7583 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7584 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7586 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7587 frame_unwind_caller_id (next_frame
));
7590 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7591 new breakpoint at the target of a jmp_buf. The handling of
7592 longjmp-resume uses the same mechanisms used for handling
7593 "step-resume" breakpoints. */
7596 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7598 /* There should never be more than one longjmp-resume breakpoint per
7599 thread, so we should never be setting a new
7600 longjmp_resume_breakpoint when one is already active. */
7601 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7603 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7604 paddress (gdbarch
, pc
));
7606 inferior_thread ()->control
.exception_resume_breakpoint
=
7607 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7610 /* Insert an exception resume breakpoint. TP is the thread throwing
7611 the exception. The block B is the block of the unwinder debug hook
7612 function. FRAME is the frame corresponding to the call to this
7613 function. SYM is the symbol of the function argument holding the
7614 target PC of the exception. */
7617 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7618 const struct block
*b
,
7619 struct frame_info
*frame
,
7624 struct block_symbol vsym
;
7625 struct value
*value
;
7627 struct breakpoint
*bp
;
7629 vsym
= lookup_symbol_search_name (sym
->search_name (),
7631 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7632 /* If the value was optimized out, revert to the old behavior. */
7633 if (! value_optimized_out (value
))
7635 handler
= value_as_address (value
);
7637 infrun_log_debug ("exception resume at %lx",
7638 (unsigned long) handler
);
7640 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7642 bp_exception_resume
).release ();
7644 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7647 bp
->thread
= tp
->global_num
;
7648 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7651 catch (const gdb_exception_error
&e
)
7653 /* We want to ignore errors here. */
7657 /* A helper for check_exception_resume that sets an
7658 exception-breakpoint based on a SystemTap probe. */
7661 insert_exception_resume_from_probe (struct thread_info
*tp
,
7662 const struct bound_probe
*probe
,
7663 struct frame_info
*frame
)
7665 struct value
*arg_value
;
7667 struct breakpoint
*bp
;
7669 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7673 handler
= value_as_address (arg_value
);
7675 infrun_log_debug ("exception resume at %s",
7676 paddress (probe
->objfile
->arch (), handler
));
7678 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7679 handler
, bp_exception_resume
).release ();
7680 bp
->thread
= tp
->global_num
;
7681 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7684 /* This is called when an exception has been intercepted. Check to
7685 see whether the exception's destination is of interest, and if so,
7686 set an exception resume breakpoint there. */
7689 check_exception_resume (struct execution_control_state
*ecs
,
7690 struct frame_info
*frame
)
7692 struct bound_probe probe
;
7693 struct symbol
*func
;
7695 /* First see if this exception unwinding breakpoint was set via a
7696 SystemTap probe point. If so, the probe has two arguments: the
7697 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7698 set a breakpoint there. */
7699 probe
= find_probe_by_pc (get_frame_pc (frame
));
7702 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7706 func
= get_frame_function (frame
);
7712 const struct block
*b
;
7713 struct block_iterator iter
;
7717 /* The exception breakpoint is a thread-specific breakpoint on
7718 the unwinder's debug hook, declared as:
7720 void _Unwind_DebugHook (void *cfa, void *handler);
7722 The CFA argument indicates the frame to which control is
7723 about to be transferred. HANDLER is the destination PC.
7725 We ignore the CFA and set a temporary breakpoint at HANDLER.
7726 This is not extremely efficient but it avoids issues in gdb
7727 with computing the DWARF CFA, and it also works even in weird
7728 cases such as throwing an exception from inside a signal
7731 b
= SYMBOL_BLOCK_VALUE (func
);
7732 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7734 if (!SYMBOL_IS_ARGUMENT (sym
))
7741 insert_exception_resume_breakpoint (ecs
->event_thread
,
7747 catch (const gdb_exception_error
&e
)
7753 stop_waiting (struct execution_control_state
*ecs
)
7755 infrun_log_debug ("stop_waiting");
7757 /* Let callers know we don't want to wait for the inferior anymore. */
7758 ecs
->wait_some_more
= 0;
7760 /* If all-stop, but there exists a non-stop target, stop all
7761 threads now that we're presenting the stop to the user. */
7762 if (!non_stop
&& exists_non_stop_target ())
7763 stop_all_threads ();
7766 /* Like keep_going, but passes the signal to the inferior, even if the
7767 signal is set to nopass. */
7770 keep_going_pass_signal (struct execution_control_state
*ecs
)
7772 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7773 gdb_assert (!ecs
->event_thread
->resumed
);
7775 /* Save the pc before execution, to compare with pc after stop. */
7776 ecs
->event_thread
->prev_pc
7777 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7779 if (ecs
->event_thread
->control
.trap_expected
)
7781 struct thread_info
*tp
= ecs
->event_thread
;
7783 infrun_log_debug ("%s has trap_expected set, "
7784 "resuming to collect trap",
7785 target_pid_to_str (tp
->ptid
).c_str ());
7787 /* We haven't yet gotten our trap, and either: intercepted a
7788 non-signal event (e.g., a fork); or took a signal which we
7789 are supposed to pass through to the inferior. Simply
7791 resume (ecs
->event_thread
->suspend
.stop_signal
);
7793 else if (step_over_info_valid_p ())
7795 /* Another thread is stepping over a breakpoint in-line. If
7796 this thread needs a step-over too, queue the request. In
7797 either case, this resume must be deferred for later. */
7798 struct thread_info
*tp
= ecs
->event_thread
;
7800 if (ecs
->hit_singlestep_breakpoint
7801 || thread_still_needs_step_over (tp
))
7803 infrun_log_debug ("step-over already in progress: "
7804 "step-over for %s deferred",
7805 target_pid_to_str (tp
->ptid
).c_str ());
7806 global_thread_step_over_chain_enqueue (tp
);
7810 infrun_log_debug ("step-over in progress: resume of %s deferred",
7811 target_pid_to_str (tp
->ptid
).c_str ());
7816 struct regcache
*regcache
= get_current_regcache ();
7819 step_over_what step_what
;
7821 /* Either the trap was not expected, but we are continuing
7822 anyway (if we got a signal, the user asked it be passed to
7825 We got our expected trap, but decided we should resume from
7828 We're going to run this baby now!
7830 Note that insert_breakpoints won't try to re-insert
7831 already inserted breakpoints. Therefore, we don't
7832 care if breakpoints were already inserted, or not. */
7834 /* If we need to step over a breakpoint, and we're not using
7835 displaced stepping to do so, insert all breakpoints
7836 (watchpoints, etc.) but the one we're stepping over, step one
7837 instruction, and then re-insert the breakpoint when that step
7840 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7842 remove_bp
= (ecs
->hit_singlestep_breakpoint
7843 || (step_what
& STEP_OVER_BREAKPOINT
));
7844 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7846 /* We can't use displaced stepping if we need to step past a
7847 watchpoint. The instruction copied to the scratch pad would
7848 still trigger the watchpoint. */
7850 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7852 set_step_over_info (regcache
->aspace (),
7853 regcache_read_pc (regcache
), remove_wps
,
7854 ecs
->event_thread
->global_num
);
7856 else if (remove_wps
)
7857 set_step_over_info (NULL
, 0, remove_wps
, -1);
7859 /* If we now need to do an in-line step-over, we need to stop
7860 all other threads. Note this must be done before
7861 insert_breakpoints below, because that removes the breakpoint
7862 we're about to step over, otherwise other threads could miss
7864 if (step_over_info_valid_p () && target_is_non_stop_p ())
7865 stop_all_threads ();
7867 /* Stop stepping if inserting breakpoints fails. */
7870 insert_breakpoints ();
7872 catch (const gdb_exception_error
&e
)
7874 exception_print (gdb_stderr
, e
);
7876 clear_step_over_info ();
7880 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7882 resume (ecs
->event_thread
->suspend
.stop_signal
);
7885 prepare_to_wait (ecs
);
7888 /* Called when we should continue running the inferior, because the
7889 current event doesn't cause a user visible stop. This does the
7890 resuming part; waiting for the next event is done elsewhere. */
7893 keep_going (struct execution_control_state
*ecs
)
7895 if (ecs
->event_thread
->control
.trap_expected
7896 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7897 ecs
->event_thread
->control
.trap_expected
= 0;
7899 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7900 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7901 keep_going_pass_signal (ecs
);
7904 /* This function normally comes after a resume, before
7905 handle_inferior_event exits. It takes care of any last bits of
7906 housekeeping, and sets the all-important wait_some_more flag. */
7909 prepare_to_wait (struct execution_control_state
*ecs
)
7911 infrun_log_debug ("prepare_to_wait");
7913 ecs
->wait_some_more
= 1;
7915 /* If the target can't async, emulate it by marking the infrun event
7916 handler such that as soon as we get back to the event-loop, we
7917 immediately end up in fetch_inferior_event again calling
7919 if (!target_can_async_p ())
7920 mark_infrun_async_event_handler ();
7923 /* We are done with the step range of a step/next/si/ni command.
7924 Called once for each n of a "step n" operation. */
7927 end_stepping_range (struct execution_control_state
*ecs
)
7929 ecs
->event_thread
->control
.stop_step
= 1;
7933 /* Several print_*_reason functions to print why the inferior has stopped.
7934 We always print something when the inferior exits, or receives a signal.
7935 The rest of the cases are dealt with later on in normal_stop and
7936 print_it_typical. Ideally there should be a call to one of these
7937 print_*_reason functions functions from handle_inferior_event each time
7938 stop_waiting is called.
7940 Note that we don't call these directly, instead we delegate that to
7941 the interpreters, through observers. Interpreters then call these
7942 with whatever uiout is right. */
7945 print_end_stepping_range_reason (struct ui_out
*uiout
)
7947 /* For CLI-like interpreters, print nothing. */
7949 if (uiout
->is_mi_like_p ())
7951 uiout
->field_string ("reason",
7952 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7957 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7959 annotate_signalled ();
7960 if (uiout
->is_mi_like_p ())
7962 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7963 uiout
->text ("\nProgram terminated with signal ");
7964 annotate_signal_name ();
7965 uiout
->field_string ("signal-name",
7966 gdb_signal_to_name (siggnal
));
7967 annotate_signal_name_end ();
7969 annotate_signal_string ();
7970 uiout
->field_string ("signal-meaning",
7971 gdb_signal_to_string (siggnal
));
7972 annotate_signal_string_end ();
7973 uiout
->text (".\n");
7974 uiout
->text ("The program no longer exists.\n");
7978 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7980 struct inferior
*inf
= current_inferior ();
7981 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7983 annotate_exited (exitstatus
);
7986 if (uiout
->is_mi_like_p ())
7987 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7988 std::string exit_code_str
7989 = string_printf ("0%o", (unsigned int) exitstatus
);
7990 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7991 plongest (inf
->num
), pidstr
.c_str (),
7992 string_field ("exit-code", exit_code_str
.c_str ()));
7996 if (uiout
->is_mi_like_p ())
7998 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7999 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8000 plongest (inf
->num
), pidstr
.c_str ());
8004 /* Some targets/architectures can do extra processing/display of
8005 segmentation faults. E.g., Intel MPX boundary faults.
8006 Call the architecture dependent function to handle the fault. */
8009 handle_segmentation_fault (struct ui_out
*uiout
)
8011 struct regcache
*regcache
= get_current_regcache ();
8012 struct gdbarch
*gdbarch
= regcache
->arch ();
8014 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8015 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8019 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8021 struct thread_info
*thr
= inferior_thread ();
8025 if (uiout
->is_mi_like_p ())
8027 else if (show_thread_that_caused_stop ())
8031 uiout
->text ("\nThread ");
8032 uiout
->field_string ("thread-id", print_thread_id (thr
));
8034 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8037 uiout
->text (" \"");
8038 uiout
->field_string ("name", name
);
8043 uiout
->text ("\nProgram");
8045 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8046 uiout
->text (" stopped");
8049 uiout
->text (" received signal ");
8050 annotate_signal_name ();
8051 if (uiout
->is_mi_like_p ())
8053 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8054 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8055 annotate_signal_name_end ();
8057 annotate_signal_string ();
8058 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8060 if (siggnal
== GDB_SIGNAL_SEGV
)
8061 handle_segmentation_fault (uiout
);
8063 annotate_signal_string_end ();
8065 uiout
->text (".\n");
8069 print_no_history_reason (struct ui_out
*uiout
)
8071 uiout
->text ("\nNo more reverse-execution history.\n");
8074 /* Print current location without a level number, if we have changed
8075 functions or hit a breakpoint. Print source line if we have one.
8076 bpstat_print contains the logic deciding in detail what to print,
8077 based on the event(s) that just occurred. */
8080 print_stop_location (struct target_waitstatus
*ws
)
8083 enum print_what source_flag
;
8084 int do_frame_printing
= 1;
8085 struct thread_info
*tp
= inferior_thread ();
8087 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8091 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8092 should) carry around the function and does (or should) use
8093 that when doing a frame comparison. */
8094 if (tp
->control
.stop_step
8095 && frame_id_eq (tp
->control
.step_frame_id
,
8096 get_frame_id (get_current_frame ()))
8097 && (tp
->control
.step_start_function
8098 == find_pc_function (tp
->suspend
.stop_pc
)))
8100 /* Finished step, just print source line. */
8101 source_flag
= SRC_LINE
;
8105 /* Print location and source line. */
8106 source_flag
= SRC_AND_LOC
;
8109 case PRINT_SRC_AND_LOC
:
8110 /* Print location and source line. */
8111 source_flag
= SRC_AND_LOC
;
8113 case PRINT_SRC_ONLY
:
8114 source_flag
= SRC_LINE
;
8117 /* Something bogus. */
8118 source_flag
= SRC_LINE
;
8119 do_frame_printing
= 0;
8122 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8125 /* The behavior of this routine with respect to the source
8127 SRC_LINE: Print only source line
8128 LOCATION: Print only location
8129 SRC_AND_LOC: Print location and source line. */
8130 if (do_frame_printing
)
8131 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8137 print_stop_event (struct ui_out
*uiout
, bool displays
)
8139 struct target_waitstatus last
;
8140 struct thread_info
*tp
;
8142 get_last_target_status (nullptr, nullptr, &last
);
8145 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8147 print_stop_location (&last
);
8149 /* Display the auto-display expressions. */
8154 tp
= inferior_thread ();
8155 if (tp
->thread_fsm
!= NULL
8156 && tp
->thread_fsm
->finished_p ())
8158 struct return_value_info
*rv
;
8160 rv
= tp
->thread_fsm
->return_value ();
8162 print_return_value (uiout
, rv
);
8169 maybe_remove_breakpoints (void)
8171 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8173 if (remove_breakpoints ())
8175 target_terminal::ours_for_output ();
8176 printf_filtered (_("Cannot remove breakpoints because "
8177 "program is no longer writable.\nFurther "
8178 "execution is probably impossible.\n"));
8183 /* The execution context that just caused a normal stop. */
8190 DISABLE_COPY_AND_ASSIGN (stop_context
);
8192 bool changed () const;
8197 /* The event PTID. */
8201 /* If stopp for a thread event, this is the thread that caused the
8203 struct thread_info
*thread
;
8205 /* The inferior that caused the stop. */
8209 /* Initializes a new stop context. If stopped for a thread event, this
8210 takes a strong reference to the thread. */
8212 stop_context::stop_context ()
8214 stop_id
= get_stop_id ();
8215 ptid
= inferior_ptid
;
8216 inf_num
= current_inferior ()->num
;
8218 if (inferior_ptid
!= null_ptid
)
8220 /* Take a strong reference so that the thread can't be deleted
8222 thread
= inferior_thread ();
8229 /* Release a stop context previously created with save_stop_context.
8230 Releases the strong reference to the thread as well. */
8232 stop_context::~stop_context ()
8238 /* Return true if the current context no longer matches the saved stop
8242 stop_context::changed () const
8244 if (ptid
!= inferior_ptid
)
8246 if (inf_num
!= current_inferior ()->num
)
8248 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8250 if (get_stop_id () != stop_id
)
8260 struct target_waitstatus last
;
8262 get_last_target_status (nullptr, nullptr, &last
);
8266 /* If an exception is thrown from this point on, make sure to
8267 propagate GDB's knowledge of the executing state to the
8268 frontend/user running state. A QUIT is an easy exception to see
8269 here, so do this before any filtered output. */
8271 ptid_t finish_ptid
= null_ptid
;
8274 finish_ptid
= minus_one_ptid
;
8275 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8276 || last
.kind
== TARGET_WAITKIND_EXITED
)
8278 /* On some targets, we may still have live threads in the
8279 inferior when we get a process exit event. E.g., for
8280 "checkpoint", when the current checkpoint/fork exits,
8281 linux-fork.c automatically switches to another fork from
8282 within target_mourn_inferior. */
8283 if (inferior_ptid
!= null_ptid
)
8284 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8286 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8287 finish_ptid
= inferior_ptid
;
8289 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8290 if (finish_ptid
!= null_ptid
)
8292 maybe_finish_thread_state
.emplace
8293 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8296 /* As we're presenting a stop, and potentially removing breakpoints,
8297 update the thread list so we can tell whether there are threads
8298 running on the target. With target remote, for example, we can
8299 only learn about new threads when we explicitly update the thread
8300 list. Do this before notifying the interpreters about signal
8301 stops, end of stepping ranges, etc., so that the "new thread"
8302 output is emitted before e.g., "Program received signal FOO",
8303 instead of after. */
8304 update_thread_list ();
8306 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8307 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8309 /* As with the notification of thread events, we want to delay
8310 notifying the user that we've switched thread context until
8311 the inferior actually stops.
8313 There's no point in saying anything if the inferior has exited.
8314 Note that SIGNALLED here means "exited with a signal", not
8315 "received a signal".
8317 Also skip saying anything in non-stop mode. In that mode, as we
8318 don't want GDB to switch threads behind the user's back, to avoid
8319 races where the user is typing a command to apply to thread x,
8320 but GDB switches to thread y before the user finishes entering
8321 the command, fetch_inferior_event installs a cleanup to restore
8322 the current thread back to the thread the user had selected right
8323 after this event is handled, so we're not really switching, only
8324 informing of a stop. */
8326 && previous_inferior_ptid
!= inferior_ptid
8327 && target_has_execution
8328 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8329 && last
.kind
!= TARGET_WAITKIND_EXITED
8330 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8332 SWITCH_THRU_ALL_UIS ()
8334 target_terminal::ours_for_output ();
8335 printf_filtered (_("[Switching to %s]\n"),
8336 target_pid_to_str (inferior_ptid
).c_str ());
8337 annotate_thread_changed ();
8339 previous_inferior_ptid
= inferior_ptid
;
8342 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8344 SWITCH_THRU_ALL_UIS ()
8345 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8347 target_terminal::ours_for_output ();
8348 printf_filtered (_("No unwaited-for children left.\n"));
8352 /* Note: this depends on the update_thread_list call above. */
8353 maybe_remove_breakpoints ();
8355 /* If an auto-display called a function and that got a signal,
8356 delete that auto-display to avoid an infinite recursion. */
8358 if (stopped_by_random_signal
)
8359 disable_current_display ();
8361 SWITCH_THRU_ALL_UIS ()
8363 async_enable_stdin ();
8366 /* Let the user/frontend see the threads as stopped. */
8367 maybe_finish_thread_state
.reset ();
8369 /* Select innermost stack frame - i.e., current frame is frame 0,
8370 and current location is based on that. Handle the case where the
8371 dummy call is returning after being stopped. E.g. the dummy call
8372 previously hit a breakpoint. (If the dummy call returns
8373 normally, we won't reach here.) Do this before the stop hook is
8374 run, so that it doesn't get to see the temporary dummy frame,
8375 which is not where we'll present the stop. */
8376 if (has_stack_frames ())
8378 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8380 /* Pop the empty frame that contains the stack dummy. This
8381 also restores inferior state prior to the call (struct
8382 infcall_suspend_state). */
8383 struct frame_info
*frame
= get_current_frame ();
8385 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8387 /* frame_pop calls reinit_frame_cache as the last thing it
8388 does which means there's now no selected frame. */
8391 select_frame (get_current_frame ());
8393 /* Set the current source location. */
8394 set_current_sal_from_frame (get_current_frame ());
8397 /* Look up the hook_stop and run it (CLI internally handles problem
8398 of stop_command's pre-hook not existing). */
8399 if (stop_command
!= NULL
)
8401 stop_context saved_context
;
8405 execute_cmd_pre_hook (stop_command
);
8407 catch (const gdb_exception
&ex
)
8409 exception_fprintf (gdb_stderr
, ex
,
8410 "Error while running hook_stop:\n");
8413 /* If the stop hook resumes the target, then there's no point in
8414 trying to notify about the previous stop; its context is
8415 gone. Likewise if the command switches thread or inferior --
8416 the observers would print a stop for the wrong
8418 if (saved_context
.changed ())
8422 /* Notify observers about the stop. This is where the interpreters
8423 print the stop event. */
8424 if (inferior_ptid
!= null_ptid
)
8425 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8428 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8430 annotate_stopped ();
8432 if (target_has_execution
)
8434 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8435 && last
.kind
!= TARGET_WAITKIND_EXITED
8436 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8437 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8438 Delete any breakpoint that is to be deleted at the next stop. */
8439 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8442 /* Try to get rid of automatically added inferiors that are no
8443 longer needed. Keeping those around slows down things linearly.
8444 Note that this never removes the current inferior. */
8451 signal_stop_state (int signo
)
8453 return signal_stop
[signo
];
8457 signal_print_state (int signo
)
8459 return signal_print
[signo
];
8463 signal_pass_state (int signo
)
8465 return signal_program
[signo
];
8469 signal_cache_update (int signo
)
8473 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8474 signal_cache_update (signo
);
8479 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8480 && signal_print
[signo
] == 0
8481 && signal_program
[signo
] == 1
8482 && signal_catch
[signo
] == 0);
8486 signal_stop_update (int signo
, int state
)
8488 int ret
= signal_stop
[signo
];
8490 signal_stop
[signo
] = state
;
8491 signal_cache_update (signo
);
8496 signal_print_update (int signo
, int state
)
8498 int ret
= signal_print
[signo
];
8500 signal_print
[signo
] = state
;
8501 signal_cache_update (signo
);
8506 signal_pass_update (int signo
, int state
)
8508 int ret
= signal_program
[signo
];
8510 signal_program
[signo
] = state
;
8511 signal_cache_update (signo
);
8515 /* Update the global 'signal_catch' from INFO and notify the
8519 signal_catch_update (const unsigned int *info
)
8523 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8524 signal_catch
[i
] = info
[i
] > 0;
8525 signal_cache_update (-1);
8526 target_pass_signals (signal_pass
);
8530 sig_print_header (void)
8532 printf_filtered (_("Signal Stop\tPrint\tPass "
8533 "to program\tDescription\n"));
8537 sig_print_info (enum gdb_signal oursig
)
8539 const char *name
= gdb_signal_to_name (oursig
);
8540 int name_padding
= 13 - strlen (name
);
8542 if (name_padding
<= 0)
8545 printf_filtered ("%s", name
);
8546 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8547 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8548 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8549 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8550 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8553 /* Specify how various signals in the inferior should be handled. */
8556 handle_command (const char *args
, int from_tty
)
8558 int digits
, wordlen
;
8559 int sigfirst
, siglast
;
8560 enum gdb_signal oursig
;
8565 error_no_arg (_("signal to handle"));
8568 /* Allocate and zero an array of flags for which signals to handle. */
8570 const size_t nsigs
= GDB_SIGNAL_LAST
;
8571 unsigned char sigs
[nsigs
] {};
8573 /* Break the command line up into args. */
8575 gdb_argv
built_argv (args
);
8577 /* Walk through the args, looking for signal oursigs, signal names, and
8578 actions. Signal numbers and signal names may be interspersed with
8579 actions, with the actions being performed for all signals cumulatively
8580 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8582 for (char *arg
: built_argv
)
8584 wordlen
= strlen (arg
);
8585 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8589 sigfirst
= siglast
= -1;
8591 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8593 /* Apply action to all signals except those used by the
8594 debugger. Silently skip those. */
8597 siglast
= nsigs
- 1;
8599 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8601 SET_SIGS (nsigs
, sigs
, signal_stop
);
8602 SET_SIGS (nsigs
, sigs
, signal_print
);
8604 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8606 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8608 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8610 SET_SIGS (nsigs
, sigs
, signal_print
);
8612 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8614 SET_SIGS (nsigs
, sigs
, signal_program
);
8616 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8618 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8620 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8622 SET_SIGS (nsigs
, sigs
, signal_program
);
8624 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8626 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8627 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8629 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8631 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8633 else if (digits
> 0)
8635 /* It is numeric. The numeric signal refers to our own
8636 internal signal numbering from target.h, not to host/target
8637 signal number. This is a feature; users really should be
8638 using symbolic names anyway, and the common ones like
8639 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8641 sigfirst
= siglast
= (int)
8642 gdb_signal_from_command (atoi (arg
));
8643 if (arg
[digits
] == '-')
8646 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8648 if (sigfirst
> siglast
)
8650 /* Bet he didn't figure we'd think of this case... */
8651 std::swap (sigfirst
, siglast
);
8656 oursig
= gdb_signal_from_name (arg
);
8657 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8659 sigfirst
= siglast
= (int) oursig
;
8663 /* Not a number and not a recognized flag word => complain. */
8664 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8668 /* If any signal numbers or symbol names were found, set flags for
8669 which signals to apply actions to. */
8671 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8673 switch ((enum gdb_signal
) signum
)
8675 case GDB_SIGNAL_TRAP
:
8676 case GDB_SIGNAL_INT
:
8677 if (!allsigs
&& !sigs
[signum
])
8679 if (query (_("%s is used by the debugger.\n\
8680 Are you sure you want to change it? "),
8681 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8686 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8690 case GDB_SIGNAL_DEFAULT
:
8691 case GDB_SIGNAL_UNKNOWN
:
8692 /* Make sure that "all" doesn't print these. */
8701 for (int signum
= 0; signum
< nsigs
; signum
++)
8704 signal_cache_update (-1);
8705 target_pass_signals (signal_pass
);
8706 target_program_signals (signal_program
);
8710 /* Show the results. */
8711 sig_print_header ();
8712 for (; signum
< nsigs
; signum
++)
8714 sig_print_info ((enum gdb_signal
) signum
);
8721 /* Complete the "handle" command. */
8724 handle_completer (struct cmd_list_element
*ignore
,
8725 completion_tracker
&tracker
,
8726 const char *text
, const char *word
)
8728 static const char * const keywords
[] =
8742 signal_completer (ignore
, tracker
, text
, word
);
8743 complete_on_enum (tracker
, keywords
, word
, word
);
8747 gdb_signal_from_command (int num
)
8749 if (num
>= 1 && num
<= 15)
8750 return (enum gdb_signal
) num
;
8751 error (_("Only signals 1-15 are valid as numeric signals.\n\
8752 Use \"info signals\" for a list of symbolic signals."));
8755 /* Print current contents of the tables set by the handle command.
8756 It is possible we should just be printing signals actually used
8757 by the current target (but for things to work right when switching
8758 targets, all signals should be in the signal tables). */
8761 info_signals_command (const char *signum_exp
, int from_tty
)
8763 enum gdb_signal oursig
;
8765 sig_print_header ();
8769 /* First see if this is a symbol name. */
8770 oursig
= gdb_signal_from_name (signum_exp
);
8771 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8773 /* No, try numeric. */
8775 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8777 sig_print_info (oursig
);
8781 printf_filtered ("\n");
8782 /* These ugly casts brought to you by the native VAX compiler. */
8783 for (oursig
= GDB_SIGNAL_FIRST
;
8784 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8785 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8789 if (oursig
!= GDB_SIGNAL_UNKNOWN
8790 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8791 sig_print_info (oursig
);
8794 printf_filtered (_("\nUse the \"handle\" command "
8795 "to change these tables.\n"));
8798 /* The $_siginfo convenience variable is a bit special. We don't know
8799 for sure the type of the value until we actually have a chance to
8800 fetch the data. The type can change depending on gdbarch, so it is
8801 also dependent on which thread you have selected.
8803 1. making $_siginfo be an internalvar that creates a new value on
8806 2. making the value of $_siginfo be an lval_computed value. */
8808 /* This function implements the lval_computed support for reading a
8812 siginfo_value_read (struct value
*v
)
8814 LONGEST transferred
;
8816 /* If we can access registers, so can we access $_siginfo. Likewise
8818 validate_registers_access ();
8821 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8823 value_contents_all_raw (v
),
8825 TYPE_LENGTH (value_type (v
)));
8827 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8828 error (_("Unable to read siginfo"));
8831 /* This function implements the lval_computed support for writing a
8835 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8837 LONGEST transferred
;
8839 /* If we can access registers, so can we access $_siginfo. Likewise
8841 validate_registers_access ();
8843 transferred
= target_write (current_top_target (),
8844 TARGET_OBJECT_SIGNAL_INFO
,
8846 value_contents_all_raw (fromval
),
8848 TYPE_LENGTH (value_type (fromval
)));
8850 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8851 error (_("Unable to write siginfo"));
8854 static const struct lval_funcs siginfo_value_funcs
=
8860 /* Return a new value with the correct type for the siginfo object of
8861 the current thread using architecture GDBARCH. Return a void value
8862 if there's no object available. */
8864 static struct value
*
8865 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8868 if (target_has_stack
8869 && inferior_ptid
!= null_ptid
8870 && gdbarch_get_siginfo_type_p (gdbarch
))
8872 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8874 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8877 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8881 /* infcall_suspend_state contains state about the program itself like its
8882 registers and any signal it received when it last stopped.
8883 This state must be restored regardless of how the inferior function call
8884 ends (either successfully, or after it hits a breakpoint or signal)
8885 if the program is to properly continue where it left off. */
8887 class infcall_suspend_state
8890 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8891 once the inferior function call has finished. */
8892 infcall_suspend_state (struct gdbarch
*gdbarch
,
8893 const struct thread_info
*tp
,
8894 struct regcache
*regcache
)
8895 : m_thread_suspend (tp
->suspend
),
8896 m_registers (new readonly_detached_regcache (*regcache
))
8898 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8900 if (gdbarch_get_siginfo_type_p (gdbarch
))
8902 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8903 size_t len
= TYPE_LENGTH (type
);
8905 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8907 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8908 siginfo_data
.get (), 0, len
) != len
)
8910 /* Errors ignored. */
8911 siginfo_data
.reset (nullptr);
8917 m_siginfo_gdbarch
= gdbarch
;
8918 m_siginfo_data
= std::move (siginfo_data
);
8922 /* Return a pointer to the stored register state. */
8924 readonly_detached_regcache
*registers () const
8926 return m_registers
.get ();
8929 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8931 void restore (struct gdbarch
*gdbarch
,
8932 struct thread_info
*tp
,
8933 struct regcache
*regcache
) const
8935 tp
->suspend
= m_thread_suspend
;
8937 if (m_siginfo_gdbarch
== gdbarch
)
8939 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8941 /* Errors ignored. */
8942 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8943 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8946 /* The inferior can be gone if the user types "print exit(0)"
8947 (and perhaps other times). */
8948 if (target_has_execution
)
8949 /* NB: The register write goes through to the target. */
8950 regcache
->restore (registers ());
8954 /* How the current thread stopped before the inferior function call was
8956 struct thread_suspend_state m_thread_suspend
;
8958 /* The registers before the inferior function call was executed. */
8959 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8961 /* Format of SIGINFO_DATA or NULL if it is not present. */
8962 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8964 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8965 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8966 content would be invalid. */
8967 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8970 infcall_suspend_state_up
8971 save_infcall_suspend_state ()
8973 struct thread_info
*tp
= inferior_thread ();
8974 struct regcache
*regcache
= get_current_regcache ();
8975 struct gdbarch
*gdbarch
= regcache
->arch ();
8977 infcall_suspend_state_up inf_state
8978 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8980 /* Having saved the current state, adjust the thread state, discarding
8981 any stop signal information. The stop signal is not useful when
8982 starting an inferior function call, and run_inferior_call will not use
8983 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8984 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8989 /* Restore inferior session state to INF_STATE. */
8992 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8994 struct thread_info
*tp
= inferior_thread ();
8995 struct regcache
*regcache
= get_current_regcache ();
8996 struct gdbarch
*gdbarch
= regcache
->arch ();
8998 inf_state
->restore (gdbarch
, tp
, regcache
);
8999 discard_infcall_suspend_state (inf_state
);
9003 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9008 readonly_detached_regcache
*
9009 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9011 return inf_state
->registers ();
9014 /* infcall_control_state contains state regarding gdb's control of the
9015 inferior itself like stepping control. It also contains session state like
9016 the user's currently selected frame. */
9018 struct infcall_control_state
9020 struct thread_control_state thread_control
;
9021 struct inferior_control_state inferior_control
;
9024 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9025 int stopped_by_random_signal
= 0;
9027 /* ID if the selected frame when the inferior function call was made. */
9028 struct frame_id selected_frame_id
{};
9031 /* Save all of the information associated with the inferior<==>gdb
9034 infcall_control_state_up
9035 save_infcall_control_state ()
9037 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9038 struct thread_info
*tp
= inferior_thread ();
9039 struct inferior
*inf
= current_inferior ();
9041 inf_status
->thread_control
= tp
->control
;
9042 inf_status
->inferior_control
= inf
->control
;
9044 tp
->control
.step_resume_breakpoint
= NULL
;
9045 tp
->control
.exception_resume_breakpoint
= NULL
;
9047 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9048 chain. If caller's caller is walking the chain, they'll be happier if we
9049 hand them back the original chain when restore_infcall_control_state is
9051 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9054 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9055 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9057 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9063 restore_selected_frame (const frame_id
&fid
)
9065 frame_info
*frame
= frame_find_by_id (fid
);
9067 /* If inf_status->selected_frame_id is NULL, there was no previously
9071 warning (_("Unable to restore previously selected frame."));
9075 select_frame (frame
);
9078 /* Restore inferior session state to INF_STATUS. */
9081 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9083 struct thread_info
*tp
= inferior_thread ();
9084 struct inferior
*inf
= current_inferior ();
9086 if (tp
->control
.step_resume_breakpoint
)
9087 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9089 if (tp
->control
.exception_resume_breakpoint
)
9090 tp
->control
.exception_resume_breakpoint
->disposition
9091 = disp_del_at_next_stop
;
9093 /* Handle the bpstat_copy of the chain. */
9094 bpstat_clear (&tp
->control
.stop_bpstat
);
9096 tp
->control
= inf_status
->thread_control
;
9097 inf
->control
= inf_status
->inferior_control
;
9100 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9101 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9103 if (target_has_stack
)
9105 /* The point of the try/catch is that if the stack is clobbered,
9106 walking the stack might encounter a garbage pointer and
9107 error() trying to dereference it. */
9110 restore_selected_frame (inf_status
->selected_frame_id
);
9112 catch (const gdb_exception_error
&ex
)
9114 exception_fprintf (gdb_stderr
, ex
,
9115 "Unable to restore previously selected frame:\n");
9116 /* Error in restoring the selected frame. Select the
9118 select_frame (get_current_frame ());
9126 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9128 if (inf_status
->thread_control
.step_resume_breakpoint
)
9129 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9130 = disp_del_at_next_stop
;
9132 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9133 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9134 = disp_del_at_next_stop
;
9136 /* See save_infcall_control_state for info on stop_bpstat. */
9137 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9145 clear_exit_convenience_vars (void)
9147 clear_internalvar (lookup_internalvar ("_exitsignal"));
9148 clear_internalvar (lookup_internalvar ("_exitcode"));
9152 /* User interface for reverse debugging:
9153 Set exec-direction / show exec-direction commands
9154 (returns error unless target implements to_set_exec_direction method). */
9156 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9157 static const char exec_forward
[] = "forward";
9158 static const char exec_reverse
[] = "reverse";
9159 static const char *exec_direction
= exec_forward
;
9160 static const char *const exec_direction_names
[] = {
9167 set_exec_direction_func (const char *args
, int from_tty
,
9168 struct cmd_list_element
*cmd
)
9170 if (target_can_execute_reverse
)
9172 if (!strcmp (exec_direction
, exec_forward
))
9173 execution_direction
= EXEC_FORWARD
;
9174 else if (!strcmp (exec_direction
, exec_reverse
))
9175 execution_direction
= EXEC_REVERSE
;
9179 exec_direction
= exec_forward
;
9180 error (_("Target does not support this operation."));
9185 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9186 struct cmd_list_element
*cmd
, const char *value
)
9188 switch (execution_direction
) {
9190 fprintf_filtered (out
, _("Forward.\n"));
9193 fprintf_filtered (out
, _("Reverse.\n"));
9196 internal_error (__FILE__
, __LINE__
,
9197 _("bogus execution_direction value: %d"),
9198 (int) execution_direction
);
9203 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9204 struct cmd_list_element
*c
, const char *value
)
9206 fprintf_filtered (file
, _("Resuming the execution of threads "
9207 "of all processes is %s.\n"), value
);
9210 /* Implementation of `siginfo' variable. */
9212 static const struct internalvar_funcs siginfo_funcs
=
9219 /* Callback for infrun's target events source. This is marked when a
9220 thread has a pending status to process. */
9223 infrun_async_inferior_event_handler (gdb_client_data data
)
9225 inferior_event_handler (INF_REG_EVENT
);
9228 void _initialize_infrun ();
9230 _initialize_infrun ()
9232 struct cmd_list_element
*c
;
9234 /* Register extra event sources in the event loop. */
9235 infrun_async_inferior_event_token
9236 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9238 add_info ("signals", info_signals_command
, _("\
9239 What debugger does when program gets various signals.\n\
9240 Specify a signal as argument to print info on that signal only."));
9241 add_info_alias ("handle", "signals", 0);
9243 c
= add_com ("handle", class_run
, handle_command
, _("\
9244 Specify how to handle signals.\n\
9245 Usage: handle SIGNAL [ACTIONS]\n\
9246 Args are signals and actions to apply to those signals.\n\
9247 If no actions are specified, the current settings for the specified signals\n\
9248 will be displayed instead.\n\
9250 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9251 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9252 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9253 The special arg \"all\" is recognized to mean all signals except those\n\
9254 used by the debugger, typically SIGTRAP and SIGINT.\n\
9256 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9257 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9258 Stop means reenter debugger if this signal happens (implies print).\n\
9259 Print means print a message if this signal happens.\n\
9260 Pass means let program see this signal; otherwise program doesn't know.\n\
9261 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9262 Pass and Stop may be combined.\n\
9264 Multiple signals may be specified. Signal numbers and signal names\n\
9265 may be interspersed with actions, with the actions being performed for\n\
9266 all signals cumulatively specified."));
9267 set_cmd_completer (c
, handle_completer
);
9270 stop_command
= add_cmd ("stop", class_obscure
,
9271 not_just_help_class_command
, _("\
9272 There is no `stop' command, but you can set a hook on `stop'.\n\
9273 This allows you to set a list of commands to be run each time execution\n\
9274 of the program stops."), &cmdlist
);
9276 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9277 Set inferior debugging."), _("\
9278 Show inferior debugging."), _("\
9279 When non-zero, inferior specific debugging is enabled."),
9282 &setdebuglist
, &showdebuglist
);
9284 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9285 &debug_displaced
, _("\
9286 Set displaced stepping debugging."), _("\
9287 Show displaced stepping debugging."), _("\
9288 When non-zero, displaced stepping specific debugging is enabled."),
9290 show_debug_displaced
,
9291 &setdebuglist
, &showdebuglist
);
9293 add_setshow_boolean_cmd ("non-stop", no_class
,
9295 Set whether gdb controls the inferior in non-stop mode."), _("\
9296 Show whether gdb controls the inferior in non-stop mode."), _("\
9297 When debugging a multi-threaded program and this setting is\n\
9298 off (the default, also called all-stop mode), when one thread stops\n\
9299 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9300 all other threads in the program while you interact with the thread of\n\
9301 interest. When you continue or step a thread, you can allow the other\n\
9302 threads to run, or have them remain stopped, but while you inspect any\n\
9303 thread's state, all threads stop.\n\
9305 In non-stop mode, when one thread stops, other threads can continue\n\
9306 to run freely. You'll be able to step each thread independently,\n\
9307 leave it stopped or free to run as needed."),
9313 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9316 signal_print
[i
] = 1;
9317 signal_program
[i
] = 1;
9318 signal_catch
[i
] = 0;
9321 /* Signals caused by debugger's own actions should not be given to
9322 the program afterwards.
9324 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9325 explicitly specifies that it should be delivered to the target
9326 program. Typically, that would occur when a user is debugging a
9327 target monitor on a simulator: the target monitor sets a
9328 breakpoint; the simulator encounters this breakpoint and halts
9329 the simulation handing control to GDB; GDB, noting that the stop
9330 address doesn't map to any known breakpoint, returns control back
9331 to the simulator; the simulator then delivers the hardware
9332 equivalent of a GDB_SIGNAL_TRAP to the program being
9334 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9335 signal_program
[GDB_SIGNAL_INT
] = 0;
9337 /* Signals that are not errors should not normally enter the debugger. */
9338 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9339 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9340 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9341 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9342 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9343 signal_print
[GDB_SIGNAL_PROF
] = 0;
9344 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9345 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9346 signal_stop
[GDB_SIGNAL_IO
] = 0;
9347 signal_print
[GDB_SIGNAL_IO
] = 0;
9348 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9349 signal_print
[GDB_SIGNAL_POLL
] = 0;
9350 signal_stop
[GDB_SIGNAL_URG
] = 0;
9351 signal_print
[GDB_SIGNAL_URG
] = 0;
9352 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9353 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9354 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9355 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9357 /* These signals are used internally by user-level thread
9358 implementations. (See signal(5) on Solaris.) Like the above
9359 signals, a healthy program receives and handles them as part of
9360 its normal operation. */
9361 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9362 signal_print
[GDB_SIGNAL_LWP
] = 0;
9363 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9364 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9365 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9366 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9367 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9368 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9370 /* Update cached state. */
9371 signal_cache_update (-1);
9373 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9374 &stop_on_solib_events
, _("\
9375 Set stopping for shared library events."), _("\
9376 Show stopping for shared library events."), _("\
9377 If nonzero, gdb will give control to the user when the dynamic linker\n\
9378 notifies gdb of shared library events. The most common event of interest\n\
9379 to the user would be loading/unloading of a new library."),
9380 set_stop_on_solib_events
,
9381 show_stop_on_solib_events
,
9382 &setlist
, &showlist
);
9384 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9385 follow_fork_mode_kind_names
,
9386 &follow_fork_mode_string
, _("\
9387 Set debugger response to a program call of fork or vfork."), _("\
9388 Show debugger response to a program call of fork or vfork."), _("\
9389 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9390 parent - the original process is debugged after a fork\n\
9391 child - the new process is debugged after a fork\n\
9392 The unfollowed process will continue to run.\n\
9393 By default, the debugger will follow the parent process."),
9395 show_follow_fork_mode_string
,
9396 &setlist
, &showlist
);
9398 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9399 follow_exec_mode_names
,
9400 &follow_exec_mode_string
, _("\
9401 Set debugger response to a program call of exec."), _("\
9402 Show debugger response to a program call of exec."), _("\
9403 An exec call replaces the program image of a process.\n\
9405 follow-exec-mode can be:\n\
9407 new - the debugger creates a new inferior and rebinds the process\n\
9408 to this new inferior. The program the process was running before\n\
9409 the exec call can be restarted afterwards by restarting the original\n\
9412 same - the debugger keeps the process bound to the same inferior.\n\
9413 The new executable image replaces the previous executable loaded in\n\
9414 the inferior. Restarting the inferior after the exec call restarts\n\
9415 the executable the process was running after the exec call.\n\
9417 By default, the debugger will use the same inferior."),
9419 show_follow_exec_mode_string
,
9420 &setlist
, &showlist
);
9422 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9423 scheduler_enums
, &scheduler_mode
, _("\
9424 Set mode for locking scheduler during execution."), _("\
9425 Show mode for locking scheduler during execution."), _("\
9426 off == no locking (threads may preempt at any time)\n\
9427 on == full locking (no thread except the current thread may run)\n\
9428 This applies to both normal execution and replay mode.\n\
9429 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9430 In this mode, other threads may run during other commands.\n\
9431 This applies to both normal execution and replay mode.\n\
9432 replay == scheduler locked in replay mode and unlocked during normal execution."),
9433 set_schedlock_func
, /* traps on target vector */
9434 show_scheduler_mode
,
9435 &setlist
, &showlist
);
9437 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9438 Set mode for resuming threads of all processes."), _("\
9439 Show mode for resuming threads of all processes."), _("\
9440 When on, execution commands (such as 'continue' or 'next') resume all\n\
9441 threads of all processes. When off (which is the default), execution\n\
9442 commands only resume the threads of the current process. The set of\n\
9443 threads that are resumed is further refined by the scheduler-locking\n\
9444 mode (see help set scheduler-locking)."),
9446 show_schedule_multiple
,
9447 &setlist
, &showlist
);
9449 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9450 Set mode of the step operation."), _("\
9451 Show mode of the step operation."), _("\
9452 When set, doing a step over a function without debug line information\n\
9453 will stop at the first instruction of that function. Otherwise, the\n\
9454 function is skipped and the step command stops at a different source line."),
9456 show_step_stop_if_no_debug
,
9457 &setlist
, &showlist
);
9459 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9460 &can_use_displaced_stepping
, _("\
9461 Set debugger's willingness to use displaced stepping."), _("\
9462 Show debugger's willingness to use displaced stepping."), _("\
9463 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9464 supported by the target architecture. If off, gdb will not use displaced\n\
9465 stepping to step over breakpoints, even if such is supported by the target\n\
9466 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9467 if the target architecture supports it and non-stop mode is active, but will not\n\
9468 use it in all-stop mode (see help set non-stop)."),
9470 show_can_use_displaced_stepping
,
9471 &setlist
, &showlist
);
9473 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9474 &exec_direction
, _("Set direction of execution.\n\
9475 Options are 'forward' or 'reverse'."),
9476 _("Show direction of execution (forward/reverse)."),
9477 _("Tells gdb whether to execute forward or backward."),
9478 set_exec_direction_func
, show_exec_direction_func
,
9479 &setlist
, &showlist
);
9481 /* Set/show detach-on-fork: user-settable mode. */
9483 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9484 Set whether gdb will detach the child of a fork."), _("\
9485 Show whether gdb will detach the child of a fork."), _("\
9486 Tells gdb whether to detach the child of a fork."),
9487 NULL
, NULL
, &setlist
, &showlist
);
9489 /* Set/show disable address space randomization mode. */
9491 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9492 &disable_randomization
, _("\
9493 Set disabling of debuggee's virtual address space randomization."), _("\
9494 Show disabling of debuggee's virtual address space randomization."), _("\
9495 When this mode is on (which is the default), randomization of the virtual\n\
9496 address space is disabled. Standalone programs run with the randomization\n\
9497 enabled by default on some platforms."),
9498 &set_disable_randomization
,
9499 &show_disable_randomization
,
9500 &setlist
, &showlist
);
9502 /* ptid initializations */
9503 inferior_ptid
= null_ptid
;
9504 target_last_wait_ptid
= minus_one_ptid
;
9506 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9507 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9508 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9509 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9511 /* Explicitly create without lookup, since that tries to create a
9512 value with a void typed value, and when we get here, gdbarch
9513 isn't initialized yet. At this point, we're quite sure there
9514 isn't another convenience variable of the same name. */
9515 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9517 add_setshow_boolean_cmd ("observer", no_class
,
9518 &observer_mode_1
, _("\
9519 Set whether gdb controls the inferior in observer mode."), _("\
9520 Show whether gdb controls the inferior in observer mode."), _("\
9521 In observer mode, GDB can get data from the inferior, but not\n\
9522 affect its execution. Registers and memory may not be changed,\n\
9523 breakpoints may not be set, and the program cannot be interrupted\n\