1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2016 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 #include "event-loop.h"
65 #include "thread-fsm.h"
66 #include "common/enum-flags.h"
68 /* Prototypes for local functions */
70 static void signals_info (char *, int);
72 static void handle_command (char *, int);
74 static void sig_print_info (enum gdb_signal
);
76 static void sig_print_header (void);
78 static void resume_cleanups (void *);
80 static int hook_stop_stub (void *);
82 static int restore_selected_frame (void *);
84 static int follow_fork (void);
86 static int follow_fork_inferior (int follow_child
, int detach_fork
);
88 static void follow_inferior_reset_breakpoints (void);
90 static void set_schedlock_func (char *args
, int from_tty
,
91 struct cmd_list_element
*c
);
93 static int currently_stepping (struct thread_info
*tp
);
95 void _initialize_infrun (void);
97 void nullify_last_target_wait_ptid (void);
99 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
101 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
103 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
105 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
107 /* Asynchronous signal handler registered as event loop source for
108 when we have pending events ready to be passed to the core. */
109 static struct async_event_handler
*infrun_async_inferior_event_token
;
111 /* Stores whether infrun_async was previously enabled or disabled.
112 Starts off as -1, indicating "never enabled/disabled". */
113 static int infrun_is_async
= -1;
118 infrun_async (int enable
)
120 if (infrun_is_async
!= enable
)
122 infrun_is_async
= enable
;
125 fprintf_unfiltered (gdb_stdlog
,
126 "infrun: infrun_async(%d)\n",
130 mark_async_event_handler (infrun_async_inferior_event_token
);
132 clear_async_event_handler (infrun_async_inferior_event_token
);
139 mark_infrun_async_event_handler (void)
141 mark_async_event_handler (infrun_async_inferior_event_token
);
144 /* When set, stop the 'step' command if we enter a function which has
145 no line number information. The normal behavior is that we step
146 over such function. */
147 int step_stop_if_no_debug
= 0;
149 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
150 struct cmd_list_element
*c
, const char *value
)
152 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
155 /* In asynchronous mode, but simulating synchronous execution. */
157 int sync_execution
= 0;
159 /* proceed and normal_stop use this to notify the user when the
160 inferior stopped in a different thread than it had been running
163 static ptid_t previous_inferior_ptid
;
165 /* If set (default for legacy reasons), when following a fork, GDB
166 will detach from one of the fork branches, child or parent.
167 Exactly which branch is detached depends on 'set follow-fork-mode'
170 static int detach_fork
= 1;
172 int debug_displaced
= 0;
174 show_debug_displaced (struct ui_file
*file
, int from_tty
,
175 struct cmd_list_element
*c
, const char *value
)
177 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
180 unsigned int debug_infrun
= 0;
182 show_debug_infrun (struct ui_file
*file
, int from_tty
,
183 struct cmd_list_element
*c
, const char *value
)
185 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
189 /* Support for disabling address space randomization. */
191 int disable_randomization
= 1;
194 show_disable_randomization (struct ui_file
*file
, int from_tty
,
195 struct cmd_list_element
*c
, const char *value
)
197 if (target_supports_disable_randomization ())
198 fprintf_filtered (file
,
199 _("Disabling randomization of debuggee's "
200 "virtual address space is %s.\n"),
203 fputs_filtered (_("Disabling randomization of debuggee's "
204 "virtual address space is unsupported on\n"
205 "this platform.\n"), file
);
209 set_disable_randomization (char *args
, int from_tty
,
210 struct cmd_list_element
*c
)
212 if (!target_supports_disable_randomization ())
213 error (_("Disabling randomization of debuggee's "
214 "virtual address space is unsupported on\n"
218 /* User interface for non-stop mode. */
221 static int non_stop_1
= 0;
224 set_non_stop (char *args
, int from_tty
,
225 struct cmd_list_element
*c
)
227 if (target_has_execution
)
229 non_stop_1
= non_stop
;
230 error (_("Cannot change this setting while the inferior is running."));
233 non_stop
= non_stop_1
;
237 show_non_stop (struct ui_file
*file
, int from_tty
,
238 struct cmd_list_element
*c
, const char *value
)
240 fprintf_filtered (file
,
241 _("Controlling the inferior in non-stop mode is %s.\n"),
245 /* "Observer mode" is somewhat like a more extreme version of
246 non-stop, in which all GDB operations that might affect the
247 target's execution have been disabled. */
249 int observer_mode
= 0;
250 static int observer_mode_1
= 0;
253 set_observer_mode (char *args
, int from_tty
,
254 struct cmd_list_element
*c
)
256 if (target_has_execution
)
258 observer_mode_1
= observer_mode
;
259 error (_("Cannot change this setting while the inferior is running."));
262 observer_mode
= observer_mode_1
;
264 may_write_registers
= !observer_mode
;
265 may_write_memory
= !observer_mode
;
266 may_insert_breakpoints
= !observer_mode
;
267 may_insert_tracepoints
= !observer_mode
;
268 /* We can insert fast tracepoints in or out of observer mode,
269 but enable them if we're going into this mode. */
271 may_insert_fast_tracepoints
= 1;
272 may_stop
= !observer_mode
;
273 update_target_permissions ();
275 /* Going *into* observer mode we must force non-stop, then
276 going out we leave it that way. */
279 pagination_enabled
= 0;
280 non_stop
= non_stop_1
= 1;
284 printf_filtered (_("Observer mode is now %s.\n"),
285 (observer_mode
? "on" : "off"));
289 show_observer_mode (struct ui_file
*file
, int from_tty
,
290 struct cmd_list_element
*c
, const char *value
)
292 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
295 /* This updates the value of observer mode based on changes in
296 permissions. Note that we are deliberately ignoring the values of
297 may-write-registers and may-write-memory, since the user may have
298 reason to enable these during a session, for instance to turn on a
299 debugging-related global. */
302 update_observer_mode (void)
306 newval
= (!may_insert_breakpoints
307 && !may_insert_tracepoints
308 && may_insert_fast_tracepoints
312 /* Let the user know if things change. */
313 if (newval
!= observer_mode
)
314 printf_filtered (_("Observer mode is now %s.\n"),
315 (newval
? "on" : "off"));
317 observer_mode
= observer_mode_1
= newval
;
320 /* Tables of how to react to signals; the user sets them. */
322 static unsigned char *signal_stop
;
323 static unsigned char *signal_print
;
324 static unsigned char *signal_program
;
326 /* Table of signals that are registered with "catch signal". A
327 non-zero entry indicates that the signal is caught by some "catch
328 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
330 static unsigned char *signal_catch
;
332 /* Table of signals that the target may silently handle.
333 This is automatically determined from the flags above,
334 and simply cached here. */
335 static unsigned char *signal_pass
;
337 #define SET_SIGS(nsigs,sigs,flags) \
339 int signum = (nsigs); \
340 while (signum-- > 0) \
341 if ((sigs)[signum]) \
342 (flags)[signum] = 1; \
345 #define UNSET_SIGS(nsigs,sigs,flags) \
347 int signum = (nsigs); \
348 while (signum-- > 0) \
349 if ((sigs)[signum]) \
350 (flags)[signum] = 0; \
353 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
354 this function is to avoid exporting `signal_program'. */
357 update_signals_program_target (void)
359 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
362 /* Value to pass to target_resume() to cause all threads to resume. */
364 #define RESUME_ALL minus_one_ptid
366 /* Command list pointer for the "stop" placeholder. */
368 static struct cmd_list_element
*stop_command
;
370 /* Nonzero if we want to give control to the user when we're notified
371 of shared library events by the dynamic linker. */
372 int stop_on_solib_events
;
374 /* Enable or disable optional shared library event breakpoints
375 as appropriate when the above flag is changed. */
378 set_stop_on_solib_events (char *args
, int from_tty
, struct cmd_list_element
*c
)
380 update_solib_breakpoints ();
384 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
385 struct cmd_list_element
*c
, const char *value
)
387 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
391 /* Nonzero after stop if current stack frame should be printed. */
393 static int stop_print_frame
;
395 /* This is a cached copy of the pid/waitstatus of the last event
396 returned by target_wait()/deprecated_target_wait_hook(). This
397 information is returned by get_last_target_status(). */
398 static ptid_t target_last_wait_ptid
;
399 static struct target_waitstatus target_last_waitstatus
;
401 static void context_switch (ptid_t ptid
);
403 void init_thread_stepping_state (struct thread_info
*tss
);
405 static const char follow_fork_mode_child
[] = "child";
406 static const char follow_fork_mode_parent
[] = "parent";
408 static const char *const follow_fork_mode_kind_names
[] = {
409 follow_fork_mode_child
,
410 follow_fork_mode_parent
,
414 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
416 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
417 struct cmd_list_element
*c
, const char *value
)
419 fprintf_filtered (file
,
420 _("Debugger response to a program "
421 "call of fork or vfork is \"%s\".\n"),
426 /* Handle changes to the inferior list based on the type of fork,
427 which process is being followed, and whether the other process
428 should be detached. On entry inferior_ptid must be the ptid of
429 the fork parent. At return inferior_ptid is the ptid of the
430 followed inferior. */
433 follow_fork_inferior (int follow_child
, int detach_fork
)
436 ptid_t parent_ptid
, child_ptid
;
438 has_vforked
= (inferior_thread ()->pending_follow
.kind
439 == TARGET_WAITKIND_VFORKED
);
440 parent_ptid
= inferior_ptid
;
441 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
444 && !non_stop
/* Non-stop always resumes both branches. */
445 && (!target_is_async_p () || sync_execution
)
446 && !(follow_child
|| detach_fork
|| sched_multi
))
448 /* The parent stays blocked inside the vfork syscall until the
449 child execs or exits. If we don't let the child run, then
450 the parent stays blocked. If we're telling the parent to run
451 in the foreground, the user will not be able to ctrl-c to get
452 back the terminal, effectively hanging the debug session. */
453 fprintf_filtered (gdb_stderr
, _("\
454 Can not resume the parent process over vfork in the foreground while\n\
455 holding the child stopped. Try \"set detach-on-fork\" or \
456 \"set schedule-multiple\".\n"));
457 /* FIXME output string > 80 columns. */
463 /* Detach new forked process? */
466 struct cleanup
*old_chain
;
468 /* Before detaching from the child, remove all breakpoints
469 from it. If we forked, then this has already been taken
470 care of by infrun.c. If we vforked however, any
471 breakpoint inserted in the parent is visible in the
472 child, even those added while stopped in a vfork
473 catchpoint. This will remove the breakpoints from the
474 parent also, but they'll be reinserted below. */
477 /* Keep breakpoints list in sync. */
478 remove_breakpoints_pid (ptid_get_pid (inferior_ptid
));
481 if (info_verbose
|| debug_infrun
)
483 /* Ensure that we have a process ptid. */
484 ptid_t process_ptid
= pid_to_ptid (ptid_get_pid (child_ptid
));
486 target_terminal_ours_for_output ();
487 fprintf_filtered (gdb_stdlog
,
488 _("Detaching after %s from child %s.\n"),
489 has_vforked
? "vfork" : "fork",
490 target_pid_to_str (process_ptid
));
495 struct inferior
*parent_inf
, *child_inf
;
496 struct cleanup
*old_chain
;
498 /* Add process to GDB's tables. */
499 child_inf
= add_inferior (ptid_get_pid (child_ptid
));
501 parent_inf
= current_inferior ();
502 child_inf
->attach_flag
= parent_inf
->attach_flag
;
503 copy_terminal_info (child_inf
, parent_inf
);
504 child_inf
->gdbarch
= parent_inf
->gdbarch
;
505 copy_inferior_target_desc_info (child_inf
, parent_inf
);
507 old_chain
= save_inferior_ptid ();
508 save_current_program_space ();
510 inferior_ptid
= child_ptid
;
511 add_thread (inferior_ptid
);
512 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
514 /* If this is a vfork child, then the address-space is
515 shared with the parent. */
518 child_inf
->pspace
= parent_inf
->pspace
;
519 child_inf
->aspace
= parent_inf
->aspace
;
521 /* The parent will be frozen until the child is done
522 with the shared region. Keep track of the
524 child_inf
->vfork_parent
= parent_inf
;
525 child_inf
->pending_detach
= 0;
526 parent_inf
->vfork_child
= child_inf
;
527 parent_inf
->pending_detach
= 0;
531 child_inf
->aspace
= new_address_space ();
532 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
533 child_inf
->removable
= 1;
534 set_current_program_space (child_inf
->pspace
);
535 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
537 /* Let the shared library layer (e.g., solib-svr4) learn
538 about this new process, relocate the cloned exec, pull
539 in shared libraries, and install the solib event
540 breakpoint. If a "cloned-VM" event was propagated
541 better throughout the core, this wouldn't be
543 solib_create_inferior_hook (0);
546 do_cleanups (old_chain
);
551 struct inferior
*parent_inf
;
553 parent_inf
= current_inferior ();
555 /* If we detached from the child, then we have to be careful
556 to not insert breakpoints in the parent until the child
557 is done with the shared memory region. However, if we're
558 staying attached to the child, then we can and should
559 insert breakpoints, so that we can debug it. A
560 subsequent child exec or exit is enough to know when does
561 the child stops using the parent's address space. */
562 parent_inf
->waiting_for_vfork_done
= detach_fork
;
563 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
568 /* Follow the child. */
569 struct inferior
*parent_inf
, *child_inf
;
570 struct program_space
*parent_pspace
;
572 if (info_verbose
|| debug_infrun
)
574 target_terminal_ours_for_output ();
575 fprintf_filtered (gdb_stdlog
,
576 _("Attaching after %s %s to child %s.\n"),
577 target_pid_to_str (parent_ptid
),
578 has_vforked
? "vfork" : "fork",
579 target_pid_to_str (child_ptid
));
582 /* Add the new inferior first, so that the target_detach below
583 doesn't unpush the target. */
585 child_inf
= add_inferior (ptid_get_pid (child_ptid
));
587 parent_inf
= current_inferior ();
588 child_inf
->attach_flag
= parent_inf
->attach_flag
;
589 copy_terminal_info (child_inf
, parent_inf
);
590 child_inf
->gdbarch
= parent_inf
->gdbarch
;
591 copy_inferior_target_desc_info (child_inf
, parent_inf
);
593 parent_pspace
= parent_inf
->pspace
;
595 /* If we're vforking, we want to hold on to the parent until the
596 child exits or execs. At child exec or exit time we can
597 remove the old breakpoints from the parent and detach or
598 resume debugging it. Otherwise, detach the parent now; we'll
599 want to reuse it's program/address spaces, but we can't set
600 them to the child before removing breakpoints from the
601 parent, otherwise, the breakpoints module could decide to
602 remove breakpoints from the wrong process (since they'd be
603 assigned to the same address space). */
607 gdb_assert (child_inf
->vfork_parent
== NULL
);
608 gdb_assert (parent_inf
->vfork_child
== NULL
);
609 child_inf
->vfork_parent
= parent_inf
;
610 child_inf
->pending_detach
= 0;
611 parent_inf
->vfork_child
= child_inf
;
612 parent_inf
->pending_detach
= detach_fork
;
613 parent_inf
->waiting_for_vfork_done
= 0;
615 else if (detach_fork
)
617 if (info_verbose
|| debug_infrun
)
619 /* Ensure that we have a process ptid. */
620 ptid_t process_ptid
= pid_to_ptid (ptid_get_pid (child_ptid
));
622 target_terminal_ours_for_output ();
623 fprintf_filtered (gdb_stdlog
,
624 _("Detaching after fork from "
626 target_pid_to_str (process_ptid
));
629 target_detach (NULL
, 0);
632 /* Note that the detach above makes PARENT_INF dangling. */
634 /* Add the child thread to the appropriate lists, and switch to
635 this new thread, before cloning the program space, and
636 informing the solib layer about this new process. */
638 inferior_ptid
= child_ptid
;
639 add_thread (inferior_ptid
);
641 /* If this is a vfork child, then the address-space is shared
642 with the parent. If we detached from the parent, then we can
643 reuse the parent's program/address spaces. */
644 if (has_vforked
|| detach_fork
)
646 child_inf
->pspace
= parent_pspace
;
647 child_inf
->aspace
= child_inf
->pspace
->aspace
;
651 child_inf
->aspace
= new_address_space ();
652 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
653 child_inf
->removable
= 1;
654 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
655 set_current_program_space (child_inf
->pspace
);
656 clone_program_space (child_inf
->pspace
, parent_pspace
);
658 /* Let the shared library layer (e.g., solib-svr4) learn
659 about this new process, relocate the cloned exec, pull in
660 shared libraries, and install the solib event breakpoint.
661 If a "cloned-VM" event was propagated better throughout
662 the core, this wouldn't be required. */
663 solib_create_inferior_hook (0);
667 return target_follow_fork (follow_child
, detach_fork
);
670 /* Tell the target to follow the fork we're stopped at. Returns true
671 if the inferior should be resumed; false, if the target for some
672 reason decided it's best not to resume. */
677 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
678 int should_resume
= 1;
679 struct thread_info
*tp
;
681 /* Copy user stepping state to the new inferior thread. FIXME: the
682 followed fork child thread should have a copy of most of the
683 parent thread structure's run control related fields, not just these.
684 Initialized to avoid "may be used uninitialized" warnings from gcc. */
685 struct breakpoint
*step_resume_breakpoint
= NULL
;
686 struct breakpoint
*exception_resume_breakpoint
= NULL
;
687 CORE_ADDR step_range_start
= 0;
688 CORE_ADDR step_range_end
= 0;
689 struct frame_id step_frame_id
= { 0 };
690 struct interp
*command_interp
= NULL
;
695 struct target_waitstatus wait_status
;
697 /* Get the last target status returned by target_wait(). */
698 get_last_target_status (&wait_ptid
, &wait_status
);
700 /* If not stopped at a fork event, then there's nothing else to
702 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
703 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
706 /* Check if we switched over from WAIT_PTID, since the event was
708 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
709 && !ptid_equal (inferior_ptid
, wait_ptid
))
711 /* We did. Switch back to WAIT_PTID thread, to tell the
712 target to follow it (in either direction). We'll
713 afterwards refuse to resume, and inform the user what
715 switch_to_thread (wait_ptid
);
720 tp
= inferior_thread ();
722 /* If there were any forks/vforks that were caught and are now to be
723 followed, then do so now. */
724 switch (tp
->pending_follow
.kind
)
726 case TARGET_WAITKIND_FORKED
:
727 case TARGET_WAITKIND_VFORKED
:
729 ptid_t parent
, child
;
731 /* If the user did a next/step, etc, over a fork call,
732 preserve the stepping state in the fork child. */
733 if (follow_child
&& should_resume
)
735 step_resume_breakpoint
= clone_momentary_breakpoint
736 (tp
->control
.step_resume_breakpoint
);
737 step_range_start
= tp
->control
.step_range_start
;
738 step_range_end
= tp
->control
.step_range_end
;
739 step_frame_id
= tp
->control
.step_frame_id
;
740 exception_resume_breakpoint
741 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
742 command_interp
= tp
->control
.command_interp
;
744 /* For now, delete the parent's sr breakpoint, otherwise,
745 parent/child sr breakpoints are considered duplicates,
746 and the child version will not be installed. Remove
747 this when the breakpoints module becomes aware of
748 inferiors and address spaces. */
749 delete_step_resume_breakpoint (tp
);
750 tp
->control
.step_range_start
= 0;
751 tp
->control
.step_range_end
= 0;
752 tp
->control
.step_frame_id
= null_frame_id
;
753 delete_exception_resume_breakpoint (tp
);
754 tp
->control
.command_interp
= NULL
;
757 parent
= inferior_ptid
;
758 child
= tp
->pending_follow
.value
.related_pid
;
760 /* Set up inferior(s) as specified by the caller, and tell the
761 target to do whatever is necessary to follow either parent
763 if (follow_fork_inferior (follow_child
, detach_fork
))
765 /* Target refused to follow, or there's some other reason
766 we shouldn't resume. */
771 /* This pending follow fork event is now handled, one way
772 or another. The previous selected thread may be gone
773 from the lists by now, but if it is still around, need
774 to clear the pending follow request. */
775 tp
= find_thread_ptid (parent
);
777 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
779 /* This makes sure we don't try to apply the "Switched
780 over from WAIT_PID" logic above. */
781 nullify_last_target_wait_ptid ();
783 /* If we followed the child, switch to it... */
786 switch_to_thread (child
);
788 /* ... and preserve the stepping state, in case the
789 user was stepping over the fork call. */
792 tp
= inferior_thread ();
793 tp
->control
.step_resume_breakpoint
794 = step_resume_breakpoint
;
795 tp
->control
.step_range_start
= step_range_start
;
796 tp
->control
.step_range_end
= step_range_end
;
797 tp
->control
.step_frame_id
= step_frame_id
;
798 tp
->control
.exception_resume_breakpoint
799 = exception_resume_breakpoint
;
800 tp
->control
.command_interp
= command_interp
;
804 /* If we get here, it was because we're trying to
805 resume from a fork catchpoint, but, the user
806 has switched threads away from the thread that
807 forked. In that case, the resume command
808 issued is most likely not applicable to the
809 child, so just warn, and refuse to resume. */
810 warning (_("Not resuming: switched threads "
811 "before following fork child."));
814 /* Reset breakpoints in the child as appropriate. */
815 follow_inferior_reset_breakpoints ();
818 switch_to_thread (parent
);
822 case TARGET_WAITKIND_SPURIOUS
:
823 /* Nothing to follow. */
826 internal_error (__FILE__
, __LINE__
,
827 "Unexpected pending_follow.kind %d\n",
828 tp
->pending_follow
.kind
);
832 return should_resume
;
836 follow_inferior_reset_breakpoints (void)
838 struct thread_info
*tp
= inferior_thread ();
840 /* Was there a step_resume breakpoint? (There was if the user
841 did a "next" at the fork() call.) If so, explicitly reset its
842 thread number. Cloned step_resume breakpoints are disabled on
843 creation, so enable it here now that it is associated with the
846 step_resumes are a form of bp that are made to be per-thread.
847 Since we created the step_resume bp when the parent process
848 was being debugged, and now are switching to the child process,
849 from the breakpoint package's viewpoint, that's a switch of
850 "threads". We must update the bp's notion of which thread
851 it is for, or it'll be ignored when it triggers. */
853 if (tp
->control
.step_resume_breakpoint
)
855 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
856 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
859 /* Treat exception_resume breakpoints like step_resume breakpoints. */
860 if (tp
->control
.exception_resume_breakpoint
)
862 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
863 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
866 /* Reinsert all breakpoints in the child. The user may have set
867 breakpoints after catching the fork, in which case those
868 were never set in the child, but only in the parent. This makes
869 sure the inserted breakpoints match the breakpoint list. */
871 breakpoint_re_set ();
872 insert_breakpoints ();
875 /* The child has exited or execed: resume threads of the parent the
876 user wanted to be executing. */
879 proceed_after_vfork_done (struct thread_info
*thread
,
882 int pid
= * (int *) arg
;
884 if (ptid_get_pid (thread
->ptid
) == pid
885 && is_running (thread
->ptid
)
886 && !is_executing (thread
->ptid
)
887 && !thread
->stop_requested
888 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
891 fprintf_unfiltered (gdb_stdlog
,
892 "infrun: resuming vfork parent thread %s\n",
893 target_pid_to_str (thread
->ptid
));
895 switch_to_thread (thread
->ptid
);
896 clear_proceed_status (0);
897 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
903 /* Called whenever we notice an exec or exit event, to handle
904 detaching or resuming a vfork parent. */
907 handle_vfork_child_exec_or_exit (int exec
)
909 struct inferior
*inf
= current_inferior ();
911 if (inf
->vfork_parent
)
913 int resume_parent
= -1;
915 /* This exec or exit marks the end of the shared memory region
916 between the parent and the child. If the user wanted to
917 detach from the parent, now is the time. */
919 if (inf
->vfork_parent
->pending_detach
)
921 struct thread_info
*tp
;
922 struct cleanup
*old_chain
;
923 struct program_space
*pspace
;
924 struct address_space
*aspace
;
926 /* follow-fork child, detach-on-fork on. */
928 inf
->vfork_parent
->pending_detach
= 0;
932 /* If we're handling a child exit, then inferior_ptid
933 points at the inferior's pid, not to a thread. */
934 old_chain
= save_inferior_ptid ();
935 save_current_program_space ();
936 save_current_inferior ();
939 old_chain
= save_current_space_and_thread ();
941 /* We're letting loose of the parent. */
942 tp
= any_live_thread_of_process (inf
->vfork_parent
->pid
);
943 switch_to_thread (tp
->ptid
);
945 /* We're about to detach from the parent, which implicitly
946 removes breakpoints from its address space. There's a
947 catch here: we want to reuse the spaces for the child,
948 but, parent/child are still sharing the pspace at this
949 point, although the exec in reality makes the kernel give
950 the child a fresh set of new pages. The problem here is
951 that the breakpoints module being unaware of this, would
952 likely chose the child process to write to the parent
953 address space. Swapping the child temporarily away from
954 the spaces has the desired effect. Yes, this is "sort
957 pspace
= inf
->pspace
;
958 aspace
= inf
->aspace
;
962 if (debug_infrun
|| info_verbose
)
964 target_terminal_ours_for_output ();
968 fprintf_filtered (gdb_stdlog
,
969 _("Detaching vfork parent process "
970 "%d after child exec.\n"),
971 inf
->vfork_parent
->pid
);
975 fprintf_filtered (gdb_stdlog
,
976 _("Detaching vfork parent process "
977 "%d after child exit.\n"),
978 inf
->vfork_parent
->pid
);
982 target_detach (NULL
, 0);
985 inf
->pspace
= pspace
;
986 inf
->aspace
= aspace
;
988 do_cleanups (old_chain
);
992 /* We're staying attached to the parent, so, really give the
993 child a new address space. */
994 inf
->pspace
= add_program_space (maybe_new_address_space ());
995 inf
->aspace
= inf
->pspace
->aspace
;
997 set_current_program_space (inf
->pspace
);
999 resume_parent
= inf
->vfork_parent
->pid
;
1001 /* Break the bonds. */
1002 inf
->vfork_parent
->vfork_child
= NULL
;
1006 struct cleanup
*old_chain
;
1007 struct program_space
*pspace
;
1009 /* If this is a vfork child exiting, then the pspace and
1010 aspaces were shared with the parent. Since we're
1011 reporting the process exit, we'll be mourning all that is
1012 found in the address space, and switching to null_ptid,
1013 preparing to start a new inferior. But, since we don't
1014 want to clobber the parent's address/program spaces, we
1015 go ahead and create a new one for this exiting
1018 /* Switch to null_ptid, so that clone_program_space doesn't want
1019 to read the selected frame of a dead process. */
1020 old_chain
= save_inferior_ptid ();
1021 inferior_ptid
= null_ptid
;
1023 /* This inferior is dead, so avoid giving the breakpoints
1024 module the option to write through to it (cloning a
1025 program space resets breakpoints). */
1028 pspace
= add_program_space (maybe_new_address_space ());
1029 set_current_program_space (pspace
);
1031 inf
->symfile_flags
= SYMFILE_NO_READ
;
1032 clone_program_space (pspace
, inf
->vfork_parent
->pspace
);
1033 inf
->pspace
= pspace
;
1034 inf
->aspace
= pspace
->aspace
;
1036 /* Put back inferior_ptid. We'll continue mourning this
1038 do_cleanups (old_chain
);
1040 resume_parent
= inf
->vfork_parent
->pid
;
1041 /* Break the bonds. */
1042 inf
->vfork_parent
->vfork_child
= NULL
;
1045 inf
->vfork_parent
= NULL
;
1047 gdb_assert (current_program_space
== inf
->pspace
);
1049 if (non_stop
&& resume_parent
!= -1)
1051 /* If the user wanted the parent to be running, let it go
1053 struct cleanup
*old_chain
= make_cleanup_restore_current_thread ();
1056 fprintf_unfiltered (gdb_stdlog
,
1057 "infrun: resuming vfork parent process %d\n",
1060 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1062 do_cleanups (old_chain
);
1067 /* Enum strings for "set|show follow-exec-mode". */
1069 static const char follow_exec_mode_new
[] = "new";
1070 static const char follow_exec_mode_same
[] = "same";
1071 static const char *const follow_exec_mode_names
[] =
1073 follow_exec_mode_new
,
1074 follow_exec_mode_same
,
1078 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1080 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1081 struct cmd_list_element
*c
, const char *value
)
1083 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1086 /* EXECD_PATHNAME is assumed to be non-NULL. */
1089 follow_exec (ptid_t ptid
, char *execd_pathname
)
1091 struct thread_info
*th
, *tmp
;
1092 struct inferior
*inf
= current_inferior ();
1093 int pid
= ptid_get_pid (ptid
);
1094 ptid_t process_ptid
;
1096 /* This is an exec event that we actually wish to pay attention to.
1097 Refresh our symbol table to the newly exec'd program, remove any
1098 momentary bp's, etc.
1100 If there are breakpoints, they aren't really inserted now,
1101 since the exec() transformed our inferior into a fresh set
1104 We want to preserve symbolic breakpoints on the list, since
1105 we have hopes that they can be reset after the new a.out's
1106 symbol table is read.
1108 However, any "raw" breakpoints must be removed from the list
1109 (e.g., the solib bp's), since their address is probably invalid
1112 And, we DON'T want to call delete_breakpoints() here, since
1113 that may write the bp's "shadow contents" (the instruction
1114 value that was overwritten witha TRAP instruction). Since
1115 we now have a new a.out, those shadow contents aren't valid. */
1117 mark_breakpoints_out ();
1119 /* The target reports the exec event to the main thread, even if
1120 some other thread does the exec, and even if the main thread was
1121 stopped or already gone. We may still have non-leader threads of
1122 the process on our list. E.g., on targets that don't have thread
1123 exit events (like remote); or on native Linux in non-stop mode if
1124 there were only two threads in the inferior and the non-leader
1125 one is the one that execs (and nothing forces an update of the
1126 thread list up to here). When debugging remotely, it's best to
1127 avoid extra traffic, when possible, so avoid syncing the thread
1128 list with the target, and instead go ahead and delete all threads
1129 of the process but one that reported the event. Note this must
1130 be done before calling update_breakpoints_after_exec, as
1131 otherwise clearing the threads' resources would reference stale
1132 thread breakpoints -- it may have been one of these threads that
1133 stepped across the exec. We could just clear their stepping
1134 states, but as long as we're iterating, might as well delete
1135 them. Deleting them now rather than at the next user-visible
1136 stop provides a nicer sequence of events for user and MI
1138 ALL_THREADS_SAFE (th
, tmp
)
1139 if (ptid_get_pid (th
->ptid
) == pid
&& !ptid_equal (th
->ptid
, ptid
))
1140 delete_thread (th
->ptid
);
1142 /* We also need to clear any left over stale state for the
1143 leader/event thread. E.g., if there was any step-resume
1144 breakpoint or similar, it's gone now. We cannot truly
1145 step-to-next statement through an exec(). */
1146 th
= inferior_thread ();
1147 th
->control
.step_resume_breakpoint
= NULL
;
1148 th
->control
.exception_resume_breakpoint
= NULL
;
1149 th
->control
.single_step_breakpoints
= NULL
;
1150 th
->control
.step_range_start
= 0;
1151 th
->control
.step_range_end
= 0;
1153 /* The user may have had the main thread held stopped in the
1154 previous image (e.g., schedlock on, or non-stop). Release
1156 th
->stop_requested
= 0;
1158 update_breakpoints_after_exec ();
1160 /* What is this a.out's name? */
1161 process_ptid
= pid_to_ptid (pid
);
1162 printf_unfiltered (_("%s is executing new program: %s\n"),
1163 target_pid_to_str (process_ptid
),
1166 /* We've followed the inferior through an exec. Therefore, the
1167 inferior has essentially been killed & reborn. */
1169 gdb_flush (gdb_stdout
);
1171 breakpoint_init_inferior (inf_execd
);
1173 if (*gdb_sysroot
!= '\0')
1175 char *name
= exec_file_find (execd_pathname
, NULL
);
1177 execd_pathname
= (char *) alloca (strlen (name
) + 1);
1178 strcpy (execd_pathname
, name
);
1182 /* Reset the shared library package. This ensures that we get a
1183 shlib event when the child reaches "_start", at which point the
1184 dld will have had a chance to initialize the child. */
1185 /* Also, loading a symbol file below may trigger symbol lookups, and
1186 we don't want those to be satisfied by the libraries of the
1187 previous incarnation of this process. */
1188 no_shared_libraries (NULL
, 0);
1190 if (follow_exec_mode_string
== follow_exec_mode_new
)
1192 /* The user wants to keep the old inferior and program spaces
1193 around. Create a new fresh one, and switch to it. */
1195 /* Do exit processing for the original inferior before adding
1196 the new inferior so we don't have two active inferiors with
1197 the same ptid, which can confuse find_inferior_ptid. */
1198 exit_inferior_num_silent (current_inferior ()->num
);
1200 inf
= add_inferior_with_spaces ();
1202 target_follow_exec (inf
, execd_pathname
);
1204 set_current_inferior (inf
);
1205 set_current_program_space (inf
->pspace
);
1210 /* The old description may no longer be fit for the new image.
1211 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1212 old description; we'll read a new one below. No need to do
1213 this on "follow-exec-mode new", as the old inferior stays
1214 around (its description is later cleared/refetched on
1216 target_clear_description ();
1219 gdb_assert (current_program_space
== inf
->pspace
);
1221 /* That a.out is now the one to use. */
1222 exec_file_attach (execd_pathname
, 0);
1224 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
1225 (Position Independent Executable) main symbol file will get applied by
1226 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
1227 the breakpoints with the zero displacement. */
1229 symbol_file_add (execd_pathname
,
1231 | SYMFILE_MAINLINE
| SYMFILE_DEFER_BP_RESET
),
1234 if ((inf
->symfile_flags
& SYMFILE_NO_READ
) == 0)
1235 set_initial_language ();
1237 /* If the target can specify a description, read it. Must do this
1238 after flipping to the new executable (because the target supplied
1239 description must be compatible with the executable's
1240 architecture, and the old executable may e.g., be 32-bit, while
1241 the new one 64-bit), and before anything involving memory or
1243 target_find_description ();
1245 solib_create_inferior_hook (0);
1247 jit_inferior_created_hook ();
1249 breakpoint_re_set ();
1251 /* Reinsert all breakpoints. (Those which were symbolic have
1252 been reset to the proper address in the new a.out, thanks
1253 to symbol_file_command...). */
1254 insert_breakpoints ();
1256 /* The next resume of this inferior should bring it to the shlib
1257 startup breakpoints. (If the user had also set bp's on
1258 "main" from the old (parent) process, then they'll auto-
1259 matically get reset there in the new process.). */
1262 /* The queue of threads that need to do a step-over operation to get
1263 past e.g., a breakpoint. What technique is used to step over the
1264 breakpoint/watchpoint does not matter -- all threads end up in the
1265 same queue, to maintain rough temporal order of execution, in order
1266 to avoid starvation, otherwise, we could e.g., find ourselves
1267 constantly stepping the same couple threads past their breakpoints
1268 over and over, if the single-step finish fast enough. */
1269 struct thread_info
*step_over_queue_head
;
1271 /* Bit flags indicating what the thread needs to step over. */
1273 enum step_over_what_flag
1275 /* Step over a breakpoint. */
1276 STEP_OVER_BREAKPOINT
= 1,
1278 /* Step past a non-continuable watchpoint, in order to let the
1279 instruction execute so we can evaluate the watchpoint
1281 STEP_OVER_WATCHPOINT
= 2
1283 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1285 /* Info about an instruction that is being stepped over. */
1287 struct step_over_info
1289 /* If we're stepping past a breakpoint, this is the address space
1290 and address of the instruction the breakpoint is set at. We'll
1291 skip inserting all breakpoints here. Valid iff ASPACE is
1293 struct address_space
*aspace
;
1296 /* The instruction being stepped over triggers a nonsteppable
1297 watchpoint. If true, we'll skip inserting watchpoints. */
1298 int nonsteppable_watchpoint_p
;
1300 /* The thread's global number. */
1304 /* The step-over info of the location that is being stepped over.
1306 Note that with async/breakpoint always-inserted mode, a user might
1307 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1308 being stepped over. As setting a new breakpoint inserts all
1309 breakpoints, we need to make sure the breakpoint being stepped over
1310 isn't inserted then. We do that by only clearing the step-over
1311 info when the step-over is actually finished (or aborted).
1313 Presently GDB can only step over one breakpoint at any given time.
1314 Given threads that can't run code in the same address space as the
1315 breakpoint's can't really miss the breakpoint, GDB could be taught
1316 to step-over at most one breakpoint per address space (so this info
1317 could move to the address space object if/when GDB is extended).
1318 The set of breakpoints being stepped over will normally be much
1319 smaller than the set of all breakpoints, so a flag in the
1320 breakpoint location structure would be wasteful. A separate list
1321 also saves complexity and run-time, as otherwise we'd have to go
1322 through all breakpoint locations clearing their flag whenever we
1323 start a new sequence. Similar considerations weigh against storing
1324 this info in the thread object. Plus, not all step overs actually
1325 have breakpoint locations -- e.g., stepping past a single-step
1326 breakpoint, or stepping to complete a non-continuable
1328 static struct step_over_info step_over_info
;
1330 /* Record the address of the breakpoint/instruction we're currently
1334 set_step_over_info (struct address_space
*aspace
, CORE_ADDR address
,
1335 int nonsteppable_watchpoint_p
,
1338 step_over_info
.aspace
= aspace
;
1339 step_over_info
.address
= address
;
1340 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1341 step_over_info
.thread
= thread
;
1344 /* Called when we're not longer stepping over a breakpoint / an
1345 instruction, so all breakpoints are free to be (re)inserted. */
1348 clear_step_over_info (void)
1351 fprintf_unfiltered (gdb_stdlog
,
1352 "infrun: clear_step_over_info\n");
1353 step_over_info
.aspace
= NULL
;
1354 step_over_info
.address
= 0;
1355 step_over_info
.nonsteppable_watchpoint_p
= 0;
1356 step_over_info
.thread
= -1;
1362 stepping_past_instruction_at (struct address_space
*aspace
,
1365 return (step_over_info
.aspace
!= NULL
1366 && breakpoint_address_match (aspace
, address
,
1367 step_over_info
.aspace
,
1368 step_over_info
.address
));
1374 thread_is_stepping_over_breakpoint (int thread
)
1376 return (step_over_info
.thread
!= -1
1377 && thread
== step_over_info
.thread
);
1383 stepping_past_nonsteppable_watchpoint (void)
1385 return step_over_info
.nonsteppable_watchpoint_p
;
1388 /* Returns true if step-over info is valid. */
1391 step_over_info_valid_p (void)
1393 return (step_over_info
.aspace
!= NULL
1394 || stepping_past_nonsteppable_watchpoint ());
1398 /* Displaced stepping. */
1400 /* In non-stop debugging mode, we must take special care to manage
1401 breakpoints properly; in particular, the traditional strategy for
1402 stepping a thread past a breakpoint it has hit is unsuitable.
1403 'Displaced stepping' is a tactic for stepping one thread past a
1404 breakpoint it has hit while ensuring that other threads running
1405 concurrently will hit the breakpoint as they should.
1407 The traditional way to step a thread T off a breakpoint in a
1408 multi-threaded program in all-stop mode is as follows:
1410 a0) Initially, all threads are stopped, and breakpoints are not
1412 a1) We single-step T, leaving breakpoints uninserted.
1413 a2) We insert breakpoints, and resume all threads.
1415 In non-stop debugging, however, this strategy is unsuitable: we
1416 don't want to have to stop all threads in the system in order to
1417 continue or step T past a breakpoint. Instead, we use displaced
1420 n0) Initially, T is stopped, other threads are running, and
1421 breakpoints are inserted.
1422 n1) We copy the instruction "under" the breakpoint to a separate
1423 location, outside the main code stream, making any adjustments
1424 to the instruction, register, and memory state as directed by
1426 n2) We single-step T over the instruction at its new location.
1427 n3) We adjust the resulting register and memory state as directed
1428 by T's architecture. This includes resetting T's PC to point
1429 back into the main instruction stream.
1432 This approach depends on the following gdbarch methods:
1434 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1435 indicate where to copy the instruction, and how much space must
1436 be reserved there. We use these in step n1.
1438 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1439 address, and makes any necessary adjustments to the instruction,
1440 register contents, and memory. We use this in step n1.
1442 - gdbarch_displaced_step_fixup adjusts registers and memory after
1443 we have successfuly single-stepped the instruction, to yield the
1444 same effect the instruction would have had if we had executed it
1445 at its original address. We use this in step n3.
1447 - gdbarch_displaced_step_free_closure provides cleanup.
1449 The gdbarch_displaced_step_copy_insn and
1450 gdbarch_displaced_step_fixup functions must be written so that
1451 copying an instruction with gdbarch_displaced_step_copy_insn,
1452 single-stepping across the copied instruction, and then applying
1453 gdbarch_displaced_insn_fixup should have the same effects on the
1454 thread's memory and registers as stepping the instruction in place
1455 would have. Exactly which responsibilities fall to the copy and
1456 which fall to the fixup is up to the author of those functions.
1458 See the comments in gdbarch.sh for details.
1460 Note that displaced stepping and software single-step cannot
1461 currently be used in combination, although with some care I think
1462 they could be made to. Software single-step works by placing
1463 breakpoints on all possible subsequent instructions; if the
1464 displaced instruction is a PC-relative jump, those breakpoints
1465 could fall in very strange places --- on pages that aren't
1466 executable, or at addresses that are not proper instruction
1467 boundaries. (We do generally let other threads run while we wait
1468 to hit the software single-step breakpoint, and they might
1469 encounter such a corrupted instruction.) One way to work around
1470 this would be to have gdbarch_displaced_step_copy_insn fully
1471 simulate the effect of PC-relative instructions (and return NULL)
1472 on architectures that use software single-stepping.
1474 In non-stop mode, we can have independent and simultaneous step
1475 requests, so more than one thread may need to simultaneously step
1476 over a breakpoint. The current implementation assumes there is
1477 only one scratch space per process. In this case, we have to
1478 serialize access to the scratch space. If thread A wants to step
1479 over a breakpoint, but we are currently waiting for some other
1480 thread to complete a displaced step, we leave thread A stopped and
1481 place it in the displaced_step_request_queue. Whenever a displaced
1482 step finishes, we pick the next thread in the queue and start a new
1483 displaced step operation on it. See displaced_step_prepare and
1484 displaced_step_fixup for details. */
1486 /* Per-inferior displaced stepping state. */
1487 struct displaced_step_inferior_state
1489 /* Pointer to next in linked list. */
1490 struct displaced_step_inferior_state
*next
;
1492 /* The process this displaced step state refers to. */
1495 /* True if preparing a displaced step ever failed. If so, we won't
1496 try displaced stepping for this inferior again. */
1499 /* If this is not null_ptid, this is the thread carrying out a
1500 displaced single-step in process PID. This thread's state will
1501 require fixing up once it has completed its step. */
1504 /* The architecture the thread had when we stepped it. */
1505 struct gdbarch
*step_gdbarch
;
1507 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1508 for post-step cleanup. */
1509 struct displaced_step_closure
*step_closure
;
1511 /* The address of the original instruction, and the copy we
1513 CORE_ADDR step_original
, step_copy
;
1515 /* Saved contents of copy area. */
1516 gdb_byte
*step_saved_copy
;
1519 /* The list of states of processes involved in displaced stepping
1521 static struct displaced_step_inferior_state
*displaced_step_inferior_states
;
1523 /* Get the displaced stepping state of process PID. */
1525 static struct displaced_step_inferior_state
*
1526 get_displaced_stepping_state (int pid
)
1528 struct displaced_step_inferior_state
*state
;
1530 for (state
= displaced_step_inferior_states
;
1532 state
= state
->next
)
1533 if (state
->pid
== pid
)
1539 /* Returns true if any inferior has a thread doing a displaced
1543 displaced_step_in_progress_any_inferior (void)
1545 struct displaced_step_inferior_state
*state
;
1547 for (state
= displaced_step_inferior_states
;
1549 state
= state
->next
)
1550 if (!ptid_equal (state
->step_ptid
, null_ptid
))
1556 /* Return true if thread represented by PTID is doing a displaced
1560 displaced_step_in_progress_thread (ptid_t ptid
)
1562 struct displaced_step_inferior_state
*displaced
;
1564 gdb_assert (!ptid_equal (ptid
, null_ptid
));
1566 displaced
= get_displaced_stepping_state (ptid_get_pid (ptid
));
1568 return (displaced
!= NULL
&& ptid_equal (displaced
->step_ptid
, ptid
));
1571 /* Return true if process PID has a thread doing a displaced step. */
1574 displaced_step_in_progress (int pid
)
1576 struct displaced_step_inferior_state
*displaced
;
1578 displaced
= get_displaced_stepping_state (pid
);
1579 if (displaced
!= NULL
&& !ptid_equal (displaced
->step_ptid
, null_ptid
))
1585 /* Add a new displaced stepping state for process PID to the displaced
1586 stepping state list, or return a pointer to an already existing
1587 entry, if it already exists. Never returns NULL. */
1589 static struct displaced_step_inferior_state
*
1590 add_displaced_stepping_state (int pid
)
1592 struct displaced_step_inferior_state
*state
;
1594 for (state
= displaced_step_inferior_states
;
1596 state
= state
->next
)
1597 if (state
->pid
== pid
)
1600 state
= XCNEW (struct displaced_step_inferior_state
);
1602 state
->next
= displaced_step_inferior_states
;
1603 displaced_step_inferior_states
= state
;
1608 /* If inferior is in displaced stepping, and ADDR equals to starting address
1609 of copy area, return corresponding displaced_step_closure. Otherwise,
1612 struct displaced_step_closure
*
1613 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1615 struct displaced_step_inferior_state
*displaced
1616 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
1618 /* If checking the mode of displaced instruction in copy area. */
1619 if (displaced
&& !ptid_equal (displaced
->step_ptid
, null_ptid
)
1620 && (displaced
->step_copy
== addr
))
1621 return displaced
->step_closure
;
1626 /* Remove the displaced stepping state of process PID. */
1629 remove_displaced_stepping_state (int pid
)
1631 struct displaced_step_inferior_state
*it
, **prev_next_p
;
1633 gdb_assert (pid
!= 0);
1635 it
= displaced_step_inferior_states
;
1636 prev_next_p
= &displaced_step_inferior_states
;
1641 *prev_next_p
= it
->next
;
1646 prev_next_p
= &it
->next
;
1652 infrun_inferior_exit (struct inferior
*inf
)
1654 remove_displaced_stepping_state (inf
->pid
);
1657 /* If ON, and the architecture supports it, GDB will use displaced
1658 stepping to step over breakpoints. If OFF, or if the architecture
1659 doesn't support it, GDB will instead use the traditional
1660 hold-and-step approach. If AUTO (which is the default), GDB will
1661 decide which technique to use to step over breakpoints depending on
1662 which of all-stop or non-stop mode is active --- displaced stepping
1663 in non-stop mode; hold-and-step in all-stop mode. */
1665 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1668 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1669 struct cmd_list_element
*c
,
1672 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1673 fprintf_filtered (file
,
1674 _("Debugger's willingness to use displaced stepping "
1675 "to step over breakpoints is %s (currently %s).\n"),
1676 value
, target_is_non_stop_p () ? "on" : "off");
1678 fprintf_filtered (file
,
1679 _("Debugger's willingness to use displaced stepping "
1680 "to step over breakpoints is %s.\n"), value
);
1683 /* Return non-zero if displaced stepping can/should be used to step
1684 over breakpoints of thread TP. */
1687 use_displaced_stepping (struct thread_info
*tp
)
1689 struct regcache
*regcache
= get_thread_regcache (tp
->ptid
);
1690 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1691 struct displaced_step_inferior_state
*displaced_state
;
1693 displaced_state
= get_displaced_stepping_state (ptid_get_pid (tp
->ptid
));
1695 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1696 && target_is_non_stop_p ())
1697 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1698 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1699 && find_record_target () == NULL
1700 && (displaced_state
== NULL
1701 || !displaced_state
->failed_before
));
1704 /* Clean out any stray displaced stepping state. */
1706 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1708 /* Indicate that there is no cleanup pending. */
1709 displaced
->step_ptid
= null_ptid
;
1711 if (displaced
->step_closure
)
1713 gdbarch_displaced_step_free_closure (displaced
->step_gdbarch
,
1714 displaced
->step_closure
);
1715 displaced
->step_closure
= NULL
;
1720 displaced_step_clear_cleanup (void *arg
)
1722 struct displaced_step_inferior_state
*state
1723 = (struct displaced_step_inferior_state
*) arg
;
1725 displaced_step_clear (state
);
1728 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1730 displaced_step_dump_bytes (struct ui_file
*file
,
1731 const gdb_byte
*buf
,
1736 for (i
= 0; i
< len
; i
++)
1737 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1738 fputs_unfiltered ("\n", file
);
1741 /* Prepare to single-step, using displaced stepping.
1743 Note that we cannot use displaced stepping when we have a signal to
1744 deliver. If we have a signal to deliver and an instruction to step
1745 over, then after the step, there will be no indication from the
1746 target whether the thread entered a signal handler or ignored the
1747 signal and stepped over the instruction successfully --- both cases
1748 result in a simple SIGTRAP. In the first case we mustn't do a
1749 fixup, and in the second case we must --- but we can't tell which.
1750 Comments in the code for 'random signals' in handle_inferior_event
1751 explain how we handle this case instead.
1753 Returns 1 if preparing was successful -- this thread is going to be
1754 stepped now; 0 if displaced stepping this thread got queued; or -1
1755 if this instruction can't be displaced stepped. */
1758 displaced_step_prepare_throw (ptid_t ptid
)
1760 struct cleanup
*old_cleanups
, *ignore_cleanups
;
1761 struct thread_info
*tp
= find_thread_ptid (ptid
);
1762 struct regcache
*regcache
= get_thread_regcache (ptid
);
1763 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1764 struct address_space
*aspace
= get_regcache_aspace (regcache
);
1765 CORE_ADDR original
, copy
;
1767 struct displaced_step_closure
*closure
;
1768 struct displaced_step_inferior_state
*displaced
;
1771 /* We should never reach this function if the architecture does not
1772 support displaced stepping. */
1773 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1775 /* Nor if the thread isn't meant to step over a breakpoint. */
1776 gdb_assert (tp
->control
.trap_expected
);
1778 /* Disable range stepping while executing in the scratch pad. We
1779 want a single-step even if executing the displaced instruction in
1780 the scratch buffer lands within the stepping range (e.g., a
1782 tp
->control
.may_range_step
= 0;
1784 /* We have to displaced step one thread at a time, as we only have
1785 access to a single scratch space per inferior. */
1787 displaced
= add_displaced_stepping_state (ptid_get_pid (ptid
));
1789 if (!ptid_equal (displaced
->step_ptid
, null_ptid
))
1791 /* Already waiting for a displaced step to finish. Defer this
1792 request and place in queue. */
1794 if (debug_displaced
)
1795 fprintf_unfiltered (gdb_stdlog
,
1796 "displaced: deferring step of %s\n",
1797 target_pid_to_str (ptid
));
1799 thread_step_over_chain_enqueue (tp
);
1804 if (debug_displaced
)
1805 fprintf_unfiltered (gdb_stdlog
,
1806 "displaced: stepping %s now\n",
1807 target_pid_to_str (ptid
));
1810 displaced_step_clear (displaced
);
1812 old_cleanups
= save_inferior_ptid ();
1813 inferior_ptid
= ptid
;
1815 original
= regcache_read_pc (regcache
);
1817 copy
= gdbarch_displaced_step_location (gdbarch
);
1818 len
= gdbarch_max_insn_length (gdbarch
);
1820 if (breakpoint_in_range_p (aspace
, copy
, len
))
1822 /* There's a breakpoint set in the scratch pad location range
1823 (which is usually around the entry point). We'd either
1824 install it before resuming, which would overwrite/corrupt the
1825 scratch pad, or if it was already inserted, this displaced
1826 step would overwrite it. The latter is OK in the sense that
1827 we already assume that no thread is going to execute the code
1828 in the scratch pad range (after initial startup) anyway, but
1829 the former is unacceptable. Simply punt and fallback to
1830 stepping over this breakpoint in-line. */
1831 if (debug_displaced
)
1833 fprintf_unfiltered (gdb_stdlog
,
1834 "displaced: breakpoint set in scratch pad. "
1835 "Stepping over breakpoint in-line instead.\n");
1838 do_cleanups (old_cleanups
);
1842 /* Save the original contents of the copy area. */
1843 displaced
->step_saved_copy
= (gdb_byte
*) xmalloc (len
);
1844 ignore_cleanups
= make_cleanup (free_current_contents
,
1845 &displaced
->step_saved_copy
);
1846 status
= target_read_memory (copy
, displaced
->step_saved_copy
, len
);
1848 throw_error (MEMORY_ERROR
,
1849 _("Error accessing memory address %s (%s) for "
1850 "displaced-stepping scratch space."),
1851 paddress (gdbarch
, copy
), safe_strerror (status
));
1852 if (debug_displaced
)
1854 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1855 paddress (gdbarch
, copy
));
1856 displaced_step_dump_bytes (gdb_stdlog
,
1857 displaced
->step_saved_copy
,
1861 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1862 original
, copy
, regcache
);
1863 if (closure
== NULL
)
1865 /* The architecture doesn't know how or want to displaced step
1866 this instruction or instruction sequence. Fallback to
1867 stepping over the breakpoint in-line. */
1868 do_cleanups (old_cleanups
);
1872 /* Save the information we need to fix things up if the step
1874 displaced
->step_ptid
= ptid
;
1875 displaced
->step_gdbarch
= gdbarch
;
1876 displaced
->step_closure
= closure
;
1877 displaced
->step_original
= original
;
1878 displaced
->step_copy
= copy
;
1880 make_cleanup (displaced_step_clear_cleanup
, displaced
);
1882 /* Resume execution at the copy. */
1883 regcache_write_pc (regcache
, copy
);
1885 discard_cleanups (ignore_cleanups
);
1887 do_cleanups (old_cleanups
);
1889 if (debug_displaced
)
1890 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1891 paddress (gdbarch
, copy
));
1896 /* Wrapper for displaced_step_prepare_throw that disabled further
1897 attempts at displaced stepping if we get a memory error. */
1900 displaced_step_prepare (ptid_t ptid
)
1906 prepared
= displaced_step_prepare_throw (ptid
);
1908 CATCH (ex
, RETURN_MASK_ERROR
)
1910 struct displaced_step_inferior_state
*displaced_state
;
1912 if (ex
.error
!= MEMORY_ERROR
1913 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1914 throw_exception (ex
);
1918 fprintf_unfiltered (gdb_stdlog
,
1919 "infrun: disabling displaced stepping: %s\n",
1923 /* Be verbose if "set displaced-stepping" is "on", silent if
1925 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1927 warning (_("disabling displaced stepping: %s"),
1931 /* Disable further displaced stepping attempts. */
1933 = get_displaced_stepping_state (ptid_get_pid (ptid
));
1934 displaced_state
->failed_before
= 1;
1942 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1943 const gdb_byte
*myaddr
, int len
)
1945 struct cleanup
*ptid_cleanup
= save_inferior_ptid ();
1947 inferior_ptid
= ptid
;
1948 write_memory (memaddr
, myaddr
, len
);
1949 do_cleanups (ptid_cleanup
);
1952 /* Restore the contents of the copy area for thread PTID. */
1955 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1958 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1960 write_memory_ptid (ptid
, displaced
->step_copy
,
1961 displaced
->step_saved_copy
, len
);
1962 if (debug_displaced
)
1963 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1964 target_pid_to_str (ptid
),
1965 paddress (displaced
->step_gdbarch
,
1966 displaced
->step_copy
));
1969 /* If we displaced stepped an instruction successfully, adjust
1970 registers and memory to yield the same effect the instruction would
1971 have had if we had executed it at its original address, and return
1972 1. If the instruction didn't complete, relocate the PC and return
1973 -1. If the thread wasn't displaced stepping, return 0. */
1976 displaced_step_fixup (ptid_t event_ptid
, enum gdb_signal signal
)
1978 struct cleanup
*old_cleanups
;
1979 struct displaced_step_inferior_state
*displaced
1980 = get_displaced_stepping_state (ptid_get_pid (event_ptid
));
1983 /* Was any thread of this process doing a displaced step? */
1984 if (displaced
== NULL
)
1987 /* Was this event for the pid we displaced? */
1988 if (ptid_equal (displaced
->step_ptid
, null_ptid
)
1989 || ! ptid_equal (displaced
->step_ptid
, event_ptid
))
1992 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, displaced
);
1994 displaced_step_restore (displaced
, displaced
->step_ptid
);
1996 /* Fixup may need to read memory/registers. Switch to the thread
1997 that we're fixing up. Also, target_stopped_by_watchpoint checks
1998 the current thread. */
1999 switch_to_thread (event_ptid
);
2001 /* Did the instruction complete successfully? */
2002 if (signal
== GDB_SIGNAL_TRAP
2003 && !(target_stopped_by_watchpoint ()
2004 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
2005 || target_have_steppable_watchpoint
)))
2007 /* Fix up the resulting state. */
2008 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
2009 displaced
->step_closure
,
2010 displaced
->step_original
,
2011 displaced
->step_copy
,
2012 get_thread_regcache (displaced
->step_ptid
));
2017 /* Since the instruction didn't complete, all we can do is
2019 struct regcache
*regcache
= get_thread_regcache (event_ptid
);
2020 CORE_ADDR pc
= regcache_read_pc (regcache
);
2022 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
2023 regcache_write_pc (regcache
, pc
);
2027 do_cleanups (old_cleanups
);
2029 displaced
->step_ptid
= null_ptid
;
2034 /* Data to be passed around while handling an event. This data is
2035 discarded between events. */
2036 struct execution_control_state
2039 /* The thread that got the event, if this was a thread event; NULL
2041 struct thread_info
*event_thread
;
2043 struct target_waitstatus ws
;
2044 int stop_func_filled_in
;
2045 CORE_ADDR stop_func_start
;
2046 CORE_ADDR stop_func_end
;
2047 const char *stop_func_name
;
2050 /* True if the event thread hit the single-step breakpoint of
2051 another thread. Thus the event doesn't cause a stop, the thread
2052 needs to be single-stepped past the single-step breakpoint before
2053 we can switch back to the original stepping thread. */
2054 int hit_singlestep_breakpoint
;
2057 /* Clear ECS and set it to point at TP. */
2060 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
2062 memset (ecs
, 0, sizeof (*ecs
));
2063 ecs
->event_thread
= tp
;
2064 ecs
->ptid
= tp
->ptid
;
2067 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
2068 static void prepare_to_wait (struct execution_control_state
*ecs
);
2069 static int keep_going_stepped_thread (struct thread_info
*tp
);
2070 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
2072 /* Are there any pending step-over requests? If so, run all we can
2073 now and return true. Otherwise, return false. */
2076 start_step_over (void)
2078 struct thread_info
*tp
, *next
;
2080 /* Don't start a new step-over if we already have an in-line
2081 step-over operation ongoing. */
2082 if (step_over_info_valid_p ())
2085 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
2087 struct execution_control_state ecss
;
2088 struct execution_control_state
*ecs
= &ecss
;
2089 step_over_what step_what
;
2090 int must_be_in_line
;
2092 next
= thread_step_over_chain_next (tp
);
2094 /* If this inferior already has a displaced step in process,
2095 don't start a new one. */
2096 if (displaced_step_in_progress (ptid_get_pid (tp
->ptid
)))
2099 step_what
= thread_still_needs_step_over (tp
);
2100 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
2101 || ((step_what
& STEP_OVER_BREAKPOINT
)
2102 && !use_displaced_stepping (tp
)));
2104 /* We currently stop all threads of all processes to step-over
2105 in-line. If we need to start a new in-line step-over, let
2106 any pending displaced steps finish first. */
2107 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
2110 thread_step_over_chain_remove (tp
);
2112 if (step_over_queue_head
== NULL
)
2115 fprintf_unfiltered (gdb_stdlog
,
2116 "infrun: step-over queue now empty\n");
2119 if (tp
->control
.trap_expected
2123 internal_error (__FILE__
, __LINE__
,
2124 "[%s] has inconsistent state: "
2125 "trap_expected=%d, resumed=%d, executing=%d\n",
2126 target_pid_to_str (tp
->ptid
),
2127 tp
->control
.trap_expected
,
2133 fprintf_unfiltered (gdb_stdlog
,
2134 "infrun: resuming [%s] for step-over\n",
2135 target_pid_to_str (tp
->ptid
));
2137 /* keep_going_pass_signal skips the step-over if the breakpoint
2138 is no longer inserted. In all-stop, we want to keep looking
2139 for a thread that needs a step-over instead of resuming TP,
2140 because we wouldn't be able to resume anything else until the
2141 target stops again. In non-stop, the resume always resumes
2142 only TP, so it's OK to let the thread resume freely. */
2143 if (!target_is_non_stop_p () && !step_what
)
2146 switch_to_thread (tp
->ptid
);
2147 reset_ecs (ecs
, tp
);
2148 keep_going_pass_signal (ecs
);
2150 if (!ecs
->wait_some_more
)
2151 error (_("Command aborted."));
2153 gdb_assert (tp
->resumed
);
2155 /* If we started a new in-line step-over, we're done. */
2156 if (step_over_info_valid_p ())
2158 gdb_assert (tp
->control
.trap_expected
);
2162 if (!target_is_non_stop_p ())
2164 /* On all-stop, shouldn't have resumed unless we needed a
2166 gdb_assert (tp
->control
.trap_expected
2167 || tp
->step_after_step_resume_breakpoint
);
2169 /* With remote targets (at least), in all-stop, we can't
2170 issue any further remote commands until the program stops
2175 /* Either the thread no longer needed a step-over, or a new
2176 displaced stepping sequence started. Even in the latter
2177 case, continue looking. Maybe we can also start another
2178 displaced step on a thread of other process. */
2184 /* Update global variables holding ptids to hold NEW_PTID if they were
2185 holding OLD_PTID. */
2187 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2189 struct displaced_step_request
*it
;
2190 struct displaced_step_inferior_state
*displaced
;
2192 if (ptid_equal (inferior_ptid
, old_ptid
))
2193 inferior_ptid
= new_ptid
;
2195 for (displaced
= displaced_step_inferior_states
;
2197 displaced
= displaced
->next
)
2199 if (ptid_equal (displaced
->step_ptid
, old_ptid
))
2200 displaced
->step_ptid
= new_ptid
;
2207 /* Things to clean up if we QUIT out of resume (). */
2209 resume_cleanups (void *ignore
)
2211 if (!ptid_equal (inferior_ptid
, null_ptid
))
2212 delete_single_step_breakpoints (inferior_thread ());
2217 static const char schedlock_off
[] = "off";
2218 static const char schedlock_on
[] = "on";
2219 static const char schedlock_step
[] = "step";
2220 static const char schedlock_replay
[] = "replay";
2221 static const char *const scheduler_enums
[] = {
2228 static const char *scheduler_mode
= schedlock_replay
;
2230 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2231 struct cmd_list_element
*c
, const char *value
)
2233 fprintf_filtered (file
,
2234 _("Mode for locking scheduler "
2235 "during execution is \"%s\".\n"),
2240 set_schedlock_func (char *args
, int from_tty
, struct cmd_list_element
*c
)
2242 if (!target_can_lock_scheduler
)
2244 scheduler_mode
= schedlock_off
;
2245 error (_("Target '%s' cannot support this command."), target_shortname
);
2249 /* True if execution commands resume all threads of all processes by
2250 default; otherwise, resume only threads of the current inferior
2252 int sched_multi
= 0;
2254 /* Try to setup for software single stepping over the specified location.
2255 Return 1 if target_resume() should use hardware single step.
2257 GDBARCH the current gdbarch.
2258 PC the location to step over. */
2261 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2265 if (execution_direction
== EXEC_FORWARD
2266 && gdbarch_software_single_step_p (gdbarch
)
2267 && gdbarch_software_single_step (gdbarch
, get_current_frame ()))
2277 user_visible_resume_ptid (int step
)
2283 /* With non-stop mode on, threads are always handled
2285 resume_ptid
= inferior_ptid
;
2287 else if ((scheduler_mode
== schedlock_on
)
2288 || (scheduler_mode
== schedlock_step
&& step
))
2290 /* User-settable 'scheduler' mode requires solo thread
2292 resume_ptid
= inferior_ptid
;
2294 else if ((scheduler_mode
== schedlock_replay
)
2295 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2297 /* User-settable 'scheduler' mode requires solo thread resume in replay
2299 resume_ptid
= inferior_ptid
;
2301 else if (!sched_multi
&& target_supports_multi_process ())
2303 /* Resume all threads of the current process (and none of other
2305 resume_ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
2309 /* Resume all threads of all processes. */
2310 resume_ptid
= RESUME_ALL
;
2316 /* Return a ptid representing the set of threads that we will resume,
2317 in the perspective of the target, assuming run control handling
2318 does not require leaving some threads stopped (e.g., stepping past
2319 breakpoint). USER_STEP indicates whether we're about to start the
2320 target for a stepping command. */
2323 internal_resume_ptid (int user_step
)
2325 /* In non-stop, we always control threads individually. Note that
2326 the target may always work in non-stop mode even with "set
2327 non-stop off", in which case user_visible_resume_ptid could
2328 return a wildcard ptid. */
2329 if (target_is_non_stop_p ())
2330 return inferior_ptid
;
2332 return user_visible_resume_ptid (user_step
);
2335 /* Wrapper for target_resume, that handles infrun-specific
2339 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2341 struct thread_info
*tp
= inferior_thread ();
2343 /* Install inferior's terminal modes. */
2344 target_terminal_inferior ();
2346 /* Avoid confusing the next resume, if the next stop/resume
2347 happens to apply to another thread. */
2348 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2350 /* Advise target which signals may be handled silently.
2352 If we have removed breakpoints because we are stepping over one
2353 in-line (in any thread), we need to receive all signals to avoid
2354 accidentally skipping a breakpoint during execution of a signal
2357 Likewise if we're displaced stepping, otherwise a trap for a
2358 breakpoint in a signal handler might be confused with the
2359 displaced step finishing. We don't make the displaced_step_fixup
2360 step distinguish the cases instead, because:
2362 - a backtrace while stopped in the signal handler would show the
2363 scratch pad as frame older than the signal handler, instead of
2364 the real mainline code.
2366 - when the thread is later resumed, the signal handler would
2367 return to the scratch pad area, which would no longer be
2369 if (step_over_info_valid_p ()
2370 || displaced_step_in_progress (ptid_get_pid (tp
->ptid
)))
2371 target_pass_signals (0, NULL
);
2373 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
2375 target_resume (resume_ptid
, step
, sig
);
2378 /* Resume the inferior, but allow a QUIT. This is useful if the user
2379 wants to interrupt some lengthy single-stepping operation
2380 (for child processes, the SIGINT goes to the inferior, and so
2381 we get a SIGINT random_signal, but for remote debugging and perhaps
2382 other targets, that's not true).
2384 SIG is the signal to give the inferior (zero for none). */
2386 resume (enum gdb_signal sig
)
2388 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
2389 struct regcache
*regcache
= get_current_regcache ();
2390 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2391 struct thread_info
*tp
= inferior_thread ();
2392 CORE_ADDR pc
= regcache_read_pc (regcache
);
2393 struct address_space
*aspace
= get_regcache_aspace (regcache
);
2395 /* This represents the user's step vs continue request. When
2396 deciding whether "set scheduler-locking step" applies, it's the
2397 user's intention that counts. */
2398 const int user_step
= tp
->control
.stepping_command
;
2399 /* This represents what we'll actually request the target to do.
2400 This can decay from a step to a continue, if e.g., we need to
2401 implement single-stepping with breakpoints (software
2405 gdb_assert (!thread_is_in_step_over_chain (tp
));
2409 if (tp
->suspend
.waitstatus_pending_p
)
2415 statstr
= target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2416 fprintf_unfiltered (gdb_stdlog
,
2417 "infrun: resume: thread %s has pending wait status %s "
2418 "(currently_stepping=%d).\n",
2419 target_pid_to_str (tp
->ptid
), statstr
,
2420 currently_stepping (tp
));
2426 /* FIXME: What should we do if we are supposed to resume this
2427 thread with a signal? Maybe we should maintain a queue of
2428 pending signals to deliver. */
2429 if (sig
!= GDB_SIGNAL_0
)
2431 warning (_("Couldn't deliver signal %s to %s."),
2432 gdb_signal_to_name (sig
), target_pid_to_str (tp
->ptid
));
2435 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2436 discard_cleanups (old_cleanups
);
2438 if (target_can_async_p ())
2443 tp
->stepped_breakpoint
= 0;
2445 /* Depends on stepped_breakpoint. */
2446 step
= currently_stepping (tp
);
2448 if (current_inferior ()->waiting_for_vfork_done
)
2450 /* Don't try to single-step a vfork parent that is waiting for
2451 the child to get out of the shared memory region (by exec'ing
2452 or exiting). This is particularly important on software
2453 single-step archs, as the child process would trip on the
2454 software single step breakpoint inserted for the parent
2455 process. Since the parent will not actually execute any
2456 instruction until the child is out of the shared region (such
2457 are vfork's semantics), it is safe to simply continue it.
2458 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2459 the parent, and tell it to `keep_going', which automatically
2460 re-sets it stepping. */
2462 fprintf_unfiltered (gdb_stdlog
,
2463 "infrun: resume : clear step\n");
2468 fprintf_unfiltered (gdb_stdlog
,
2469 "infrun: resume (step=%d, signal=%s), "
2470 "trap_expected=%d, current thread [%s] at %s\n",
2471 step
, gdb_signal_to_symbol_string (sig
),
2472 tp
->control
.trap_expected
,
2473 target_pid_to_str (inferior_ptid
),
2474 paddress (gdbarch
, pc
));
2476 /* Normally, by the time we reach `resume', the breakpoints are either
2477 removed or inserted, as appropriate. The exception is if we're sitting
2478 at a permanent breakpoint; we need to step over it, but permanent
2479 breakpoints can't be removed. So we have to test for it here. */
2480 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2482 if (sig
!= GDB_SIGNAL_0
)
2484 /* We have a signal to pass to the inferior. The resume
2485 may, or may not take us to the signal handler. If this
2486 is a step, we'll need to stop in the signal handler, if
2487 there's one, (if the target supports stepping into
2488 handlers), or in the next mainline instruction, if
2489 there's no handler. If this is a continue, we need to be
2490 sure to run the handler with all breakpoints inserted.
2491 In all cases, set a breakpoint at the current address
2492 (where the handler returns to), and once that breakpoint
2493 is hit, resume skipping the permanent breakpoint. If
2494 that breakpoint isn't hit, then we've stepped into the
2495 signal handler (or hit some other event). We'll delete
2496 the step-resume breakpoint then. */
2499 fprintf_unfiltered (gdb_stdlog
,
2500 "infrun: resume: skipping permanent breakpoint, "
2501 "deliver signal first\n");
2503 clear_step_over_info ();
2504 tp
->control
.trap_expected
= 0;
2506 if (tp
->control
.step_resume_breakpoint
== NULL
)
2508 /* Set a "high-priority" step-resume, as we don't want
2509 user breakpoints at PC to trigger (again) when this
2511 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2512 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2514 tp
->step_after_step_resume_breakpoint
= step
;
2517 insert_breakpoints ();
2521 /* There's no signal to pass, we can go ahead and skip the
2522 permanent breakpoint manually. */
2524 fprintf_unfiltered (gdb_stdlog
,
2525 "infrun: resume: skipping permanent breakpoint\n");
2526 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2527 /* Update pc to reflect the new address from which we will
2528 execute instructions. */
2529 pc
= regcache_read_pc (regcache
);
2533 /* We've already advanced the PC, so the stepping part
2534 is done. Now we need to arrange for a trap to be
2535 reported to handle_inferior_event. Set a breakpoint
2536 at the current PC, and run to it. Don't update
2537 prev_pc, because if we end in
2538 switch_back_to_stepped_thread, we want the "expected
2539 thread advanced also" branch to be taken. IOW, we
2540 don't want this thread to step further from PC
2542 gdb_assert (!step_over_info_valid_p ());
2543 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2544 insert_breakpoints ();
2546 resume_ptid
= internal_resume_ptid (user_step
);
2547 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2548 discard_cleanups (old_cleanups
);
2555 /* If we have a breakpoint to step over, make sure to do a single
2556 step only. Same if we have software watchpoints. */
2557 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2558 tp
->control
.may_range_step
= 0;
2560 /* If enabled, step over breakpoints by executing a copy of the
2561 instruction at a different address.
2563 We can't use displaced stepping when we have a signal to deliver;
2564 the comments for displaced_step_prepare explain why. The
2565 comments in the handle_inferior event for dealing with 'random
2566 signals' explain what we do instead.
2568 We can't use displaced stepping when we are waiting for vfork_done
2569 event, displaced stepping breaks the vfork child similarly as single
2570 step software breakpoint. */
2571 if (tp
->control
.trap_expected
2572 && use_displaced_stepping (tp
)
2573 && !step_over_info_valid_p ()
2574 && sig
== GDB_SIGNAL_0
2575 && !current_inferior ()->waiting_for_vfork_done
)
2577 int prepared
= displaced_step_prepare (inferior_ptid
);
2582 fprintf_unfiltered (gdb_stdlog
,
2583 "Got placed in step-over queue\n");
2585 tp
->control
.trap_expected
= 0;
2586 discard_cleanups (old_cleanups
);
2589 else if (prepared
< 0)
2591 /* Fallback to stepping over the breakpoint in-line. */
2593 if (target_is_non_stop_p ())
2594 stop_all_threads ();
2596 set_step_over_info (get_regcache_aspace (regcache
),
2597 regcache_read_pc (regcache
), 0, tp
->global_num
);
2599 step
= maybe_software_singlestep (gdbarch
, pc
);
2601 insert_breakpoints ();
2603 else if (prepared
> 0)
2605 struct displaced_step_inferior_state
*displaced
;
2607 /* Update pc to reflect the new address from which we will
2608 execute instructions due to displaced stepping. */
2609 pc
= regcache_read_pc (get_thread_regcache (inferior_ptid
));
2611 displaced
= get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
2612 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2613 displaced
->step_closure
);
2617 /* Do we need to do it the hard way, w/temp breakpoints? */
2619 step
= maybe_software_singlestep (gdbarch
, pc
);
2621 /* Currently, our software single-step implementation leads to different
2622 results than hardware single-stepping in one situation: when stepping
2623 into delivering a signal which has an associated signal handler,
2624 hardware single-step will stop at the first instruction of the handler,
2625 while software single-step will simply skip execution of the handler.
2627 For now, this difference in behavior is accepted since there is no
2628 easy way to actually implement single-stepping into a signal handler
2629 without kernel support.
2631 However, there is one scenario where this difference leads to follow-on
2632 problems: if we're stepping off a breakpoint by removing all breakpoints
2633 and then single-stepping. In this case, the software single-step
2634 behavior means that even if there is a *breakpoint* in the signal
2635 handler, GDB still would not stop.
2637 Fortunately, we can at least fix this particular issue. We detect
2638 here the case where we are about to deliver a signal while software
2639 single-stepping with breakpoints removed. In this situation, we
2640 revert the decisions to remove all breakpoints and insert single-
2641 step breakpoints, and instead we install a step-resume breakpoint
2642 at the current address, deliver the signal without stepping, and
2643 once we arrive back at the step-resume breakpoint, actually step
2644 over the breakpoint we originally wanted to step over. */
2645 if (thread_has_single_step_breakpoints_set (tp
)
2646 && sig
!= GDB_SIGNAL_0
2647 && step_over_info_valid_p ())
2649 /* If we have nested signals or a pending signal is delivered
2650 immediately after a handler returns, might might already have
2651 a step-resume breakpoint set on the earlier handler. We cannot
2652 set another step-resume breakpoint; just continue on until the
2653 original breakpoint is hit. */
2654 if (tp
->control
.step_resume_breakpoint
== NULL
)
2656 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2657 tp
->step_after_step_resume_breakpoint
= 1;
2660 delete_single_step_breakpoints (tp
);
2662 clear_step_over_info ();
2663 tp
->control
.trap_expected
= 0;
2665 insert_breakpoints ();
2668 /* If STEP is set, it's a request to use hardware stepping
2669 facilities. But in that case, we should never
2670 use singlestep breakpoint. */
2671 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2673 /* Decide the set of threads to ask the target to resume. */
2674 if (tp
->control
.trap_expected
)
2676 /* We're allowing a thread to run past a breakpoint it has
2677 hit, either by single-stepping the thread with the breakpoint
2678 removed, or by displaced stepping, with the breakpoint inserted.
2679 In the former case, we need to single-step only this thread,
2680 and keep others stopped, as they can miss this breakpoint if
2681 allowed to run. That's not really a problem for displaced
2682 stepping, but, we still keep other threads stopped, in case
2683 another thread is also stopped for a breakpoint waiting for
2684 its turn in the displaced stepping queue. */
2685 resume_ptid
= inferior_ptid
;
2688 resume_ptid
= internal_resume_ptid (user_step
);
2690 if (execution_direction
!= EXEC_REVERSE
2691 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2693 /* There are two cases where we currently need to step a
2694 breakpoint instruction when we have a signal to deliver:
2696 - See handle_signal_stop where we handle random signals that
2697 could take out us out of the stepping range. Normally, in
2698 that case we end up continuing (instead of stepping) over the
2699 signal handler with a breakpoint at PC, but there are cases
2700 where we should _always_ single-step, even if we have a
2701 step-resume breakpoint, like when a software watchpoint is
2702 set. Assuming single-stepping and delivering a signal at the
2703 same time would takes us to the signal handler, then we could
2704 have removed the breakpoint at PC to step over it. However,
2705 some hardware step targets (like e.g., Mac OS) can't step
2706 into signal handlers, and for those, we need to leave the
2707 breakpoint at PC inserted, as otherwise if the handler
2708 recurses and executes PC again, it'll miss the breakpoint.
2709 So we leave the breakpoint inserted anyway, but we need to
2710 record that we tried to step a breakpoint instruction, so
2711 that adjust_pc_after_break doesn't end up confused.
2713 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2714 in one thread after another thread that was stepping had been
2715 momentarily paused for a step-over. When we re-resume the
2716 stepping thread, it may be resumed from that address with a
2717 breakpoint that hasn't trapped yet. Seen with
2718 gdb.threads/non-stop-fair-events.exp, on targets that don't
2719 do displaced stepping. */
2722 fprintf_unfiltered (gdb_stdlog
,
2723 "infrun: resume: [%s] stepped breakpoint\n",
2724 target_pid_to_str (tp
->ptid
));
2726 tp
->stepped_breakpoint
= 1;
2728 /* Most targets can step a breakpoint instruction, thus
2729 executing it normally. But if this one cannot, just
2730 continue and we will hit it anyway. */
2731 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2736 && tp
->control
.trap_expected
2737 && use_displaced_stepping (tp
)
2738 && !step_over_info_valid_p ())
2740 struct regcache
*resume_regcache
= get_thread_regcache (tp
->ptid
);
2741 struct gdbarch
*resume_gdbarch
= get_regcache_arch (resume_regcache
);
2742 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2745 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2746 paddress (resume_gdbarch
, actual_pc
));
2747 read_memory (actual_pc
, buf
, sizeof (buf
));
2748 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2751 if (tp
->control
.may_range_step
)
2753 /* If we're resuming a thread with the PC out of the step
2754 range, then we're doing some nested/finer run control
2755 operation, like stepping the thread out of the dynamic
2756 linker or the displaced stepping scratch pad. We
2757 shouldn't have allowed a range step then. */
2758 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2761 do_target_resume (resume_ptid
, step
, sig
);
2763 discard_cleanups (old_cleanups
);
2770 /* Counter that tracks number of user visible stops. This can be used
2771 to tell whether a command has proceeded the inferior past the
2772 current location. This allows e.g., inferior function calls in
2773 breakpoint commands to not interrupt the command list. When the
2774 call finishes successfully, the inferior is standing at the same
2775 breakpoint as if nothing happened (and so we don't call
2777 static ULONGEST current_stop_id
;
2784 return current_stop_id
;
2787 /* Called when we report a user visible stop. */
2795 /* Clear out all variables saying what to do when inferior is continued.
2796 First do this, then set the ones you want, then call `proceed'. */
2799 clear_proceed_status_thread (struct thread_info
*tp
)
2802 fprintf_unfiltered (gdb_stdlog
,
2803 "infrun: clear_proceed_status_thread (%s)\n",
2804 target_pid_to_str (tp
->ptid
));
2806 /* If we're starting a new sequence, then the previous finished
2807 single-step is no longer relevant. */
2808 if (tp
->suspend
.waitstatus_pending_p
)
2810 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2813 fprintf_unfiltered (gdb_stdlog
,
2814 "infrun: clear_proceed_status: pending "
2815 "event of %s was a finished step. "
2817 target_pid_to_str (tp
->ptid
));
2819 tp
->suspend
.waitstatus_pending_p
= 0;
2820 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2822 else if (debug_infrun
)
2826 statstr
= target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2827 fprintf_unfiltered (gdb_stdlog
,
2828 "infrun: clear_proceed_status_thread: thread %s "
2829 "has pending wait status %s "
2830 "(currently_stepping=%d).\n",
2831 target_pid_to_str (tp
->ptid
), statstr
,
2832 currently_stepping (tp
));
2837 /* If this signal should not be seen by program, give it zero.
2838 Used for debugging signals. */
2839 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2840 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2842 thread_fsm_delete (tp
->thread_fsm
);
2843 tp
->thread_fsm
= NULL
;
2845 tp
->control
.trap_expected
= 0;
2846 tp
->control
.step_range_start
= 0;
2847 tp
->control
.step_range_end
= 0;
2848 tp
->control
.may_range_step
= 0;
2849 tp
->control
.step_frame_id
= null_frame_id
;
2850 tp
->control
.step_stack_frame_id
= null_frame_id
;
2851 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2852 tp
->control
.step_start_function
= NULL
;
2853 tp
->stop_requested
= 0;
2855 tp
->control
.stop_step
= 0;
2857 tp
->control
.proceed_to_finish
= 0;
2859 tp
->control
.command_interp
= NULL
;
2860 tp
->control
.stepping_command
= 0;
2862 /* Discard any remaining commands or status from previous stop. */
2863 bpstat_clear (&tp
->control
.stop_bpstat
);
2867 clear_proceed_status (int step
)
2869 /* With scheduler-locking replay, stop replaying other threads if we're
2870 not replaying the user-visible resume ptid.
2872 This is a convenience feature to not require the user to explicitly
2873 stop replaying the other threads. We're assuming that the user's
2874 intent is to resume tracing the recorded process. */
2875 if (!non_stop
&& scheduler_mode
== schedlock_replay
2876 && target_record_is_replaying (minus_one_ptid
)
2877 && !target_record_will_replay (user_visible_resume_ptid (step
),
2878 execution_direction
))
2879 target_record_stop_replaying ();
2883 struct thread_info
*tp
;
2886 resume_ptid
= user_visible_resume_ptid (step
);
2888 /* In all-stop mode, delete the per-thread status of all threads
2889 we're about to resume, implicitly and explicitly. */
2890 ALL_NON_EXITED_THREADS (tp
)
2892 if (!ptid_match (tp
->ptid
, resume_ptid
))
2894 clear_proceed_status_thread (tp
);
2898 if (!ptid_equal (inferior_ptid
, null_ptid
))
2900 struct inferior
*inferior
;
2904 /* If in non-stop mode, only delete the per-thread status of
2905 the current thread. */
2906 clear_proceed_status_thread (inferior_thread ());
2909 inferior
= current_inferior ();
2910 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2913 observer_notify_about_to_proceed ();
2916 /* Returns true if TP is still stopped at a breakpoint that needs
2917 stepping-over in order to make progress. If the breakpoint is gone
2918 meanwhile, we can skip the whole step-over dance. */
2921 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2923 if (tp
->stepping_over_breakpoint
)
2925 struct regcache
*regcache
= get_thread_regcache (tp
->ptid
);
2927 if (breakpoint_here_p (get_regcache_aspace (regcache
),
2928 regcache_read_pc (regcache
))
2929 == ordinary_breakpoint_here
)
2932 tp
->stepping_over_breakpoint
= 0;
2938 /* Check whether thread TP still needs to start a step-over in order
2939 to make progress when resumed. Returns an bitwise or of enum
2940 step_over_what bits, indicating what needs to be stepped over. */
2942 static step_over_what
2943 thread_still_needs_step_over (struct thread_info
*tp
)
2945 struct inferior
*inf
= find_inferior_ptid (tp
->ptid
);
2946 step_over_what what
= 0;
2948 if (thread_still_needs_step_over_bp (tp
))
2949 what
|= STEP_OVER_BREAKPOINT
;
2951 if (tp
->stepping_over_watchpoint
2952 && !target_have_steppable_watchpoint
)
2953 what
|= STEP_OVER_WATCHPOINT
;
2958 /* Returns true if scheduler locking applies. STEP indicates whether
2959 we're about to do a step/next-like command to a thread. */
2962 schedlock_applies (struct thread_info
*tp
)
2964 return (scheduler_mode
== schedlock_on
2965 || (scheduler_mode
== schedlock_step
2966 && tp
->control
.stepping_command
)
2967 || (scheduler_mode
== schedlock_replay
2968 && target_record_will_replay (minus_one_ptid
,
2969 execution_direction
)));
2972 /* Basic routine for continuing the program in various fashions.
2974 ADDR is the address to resume at, or -1 for resume where stopped.
2975 SIGGNAL is the signal to give it, or 0 for none,
2976 or -1 for act according to how it stopped.
2977 STEP is nonzero if should trap after one instruction.
2978 -1 means return after that and print nothing.
2979 You should probably set various step_... variables
2980 before calling here, if you are stepping.
2982 You should call clear_proceed_status before calling proceed. */
2985 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2987 struct regcache
*regcache
;
2988 struct gdbarch
*gdbarch
;
2989 struct thread_info
*tp
;
2991 struct address_space
*aspace
;
2993 struct execution_control_state ecss
;
2994 struct execution_control_state
*ecs
= &ecss
;
2995 struct cleanup
*old_chain
;
2998 /* If we're stopped at a fork/vfork, follow the branch set by the
2999 "set follow-fork-mode" command; otherwise, we'll just proceed
3000 resuming the current thread. */
3001 if (!follow_fork ())
3003 /* The target for some reason decided not to resume. */
3005 if (target_can_async_p ())
3006 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3010 /* We'll update this if & when we switch to a new thread. */
3011 previous_inferior_ptid
= inferior_ptid
;
3013 regcache
= get_current_regcache ();
3014 gdbarch
= get_regcache_arch (regcache
);
3015 aspace
= get_regcache_aspace (regcache
);
3016 pc
= regcache_read_pc (regcache
);
3017 tp
= inferior_thread ();
3019 /* Fill in with reasonable starting values. */
3020 init_thread_stepping_state (tp
);
3022 gdb_assert (!thread_is_in_step_over_chain (tp
));
3024 if (addr
== (CORE_ADDR
) -1)
3027 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3028 && execution_direction
!= EXEC_REVERSE
)
3029 /* There is a breakpoint at the address we will resume at,
3030 step one instruction before inserting breakpoints so that
3031 we do not stop right away (and report a second hit at this
3034 Note, we don't do this in reverse, because we won't
3035 actually be executing the breakpoint insn anyway.
3036 We'll be (un-)executing the previous instruction. */
3037 tp
->stepping_over_breakpoint
= 1;
3038 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3039 && gdbarch_single_step_through_delay (gdbarch
,
3040 get_current_frame ()))
3041 /* We stepped onto an instruction that needs to be stepped
3042 again before re-inserting the breakpoint, do so. */
3043 tp
->stepping_over_breakpoint
= 1;
3047 regcache_write_pc (regcache
, addr
);
3050 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3051 tp
->suspend
.stop_signal
= siggnal
;
3053 /* Record the interpreter that issued the execution command that
3054 caused this thread to resume. If the top level interpreter is
3055 MI/async, and the execution command was a CLI command
3056 (next/step/etc.), we'll want to print stop event output to the MI
3057 console channel (the stepped-to line, etc.), as if the user
3058 entered the execution command on a real GDB console. */
3059 tp
->control
.command_interp
= command_interp ();
3061 resume_ptid
= user_visible_resume_ptid (tp
->control
.stepping_command
);
3063 /* If an exception is thrown from this point on, make sure to
3064 propagate GDB's knowledge of the executing state to the
3065 frontend/user running state. */
3066 old_chain
= make_cleanup (finish_thread_state_cleanup
, &resume_ptid
);
3068 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3069 threads (e.g., we might need to set threads stepping over
3070 breakpoints first), from the user/frontend's point of view, all
3071 threads in RESUME_PTID are now running. Unless we're calling an
3072 inferior function, as in that case we pretend the inferior
3073 doesn't run at all. */
3074 if (!tp
->control
.in_infcall
)
3075 set_running (resume_ptid
, 1);
3078 fprintf_unfiltered (gdb_stdlog
,
3079 "infrun: proceed (addr=%s, signal=%s)\n",
3080 paddress (gdbarch
, addr
),
3081 gdb_signal_to_symbol_string (siggnal
));
3083 annotate_starting ();
3085 /* Make sure that output from GDB appears before output from the
3087 gdb_flush (gdb_stdout
);
3089 /* In a multi-threaded task we may select another thread and
3090 then continue or step.
3092 But if a thread that we're resuming had stopped at a breakpoint,
3093 it will immediately cause another breakpoint stop without any
3094 execution (i.e. it will report a breakpoint hit incorrectly). So
3095 we must step over it first.
3097 Look for threads other than the current (TP) that reported a
3098 breakpoint hit and haven't been resumed yet since. */
3100 /* If scheduler locking applies, we can avoid iterating over all
3102 if (!non_stop
&& !schedlock_applies (tp
))
3104 struct thread_info
*current
= tp
;
3106 ALL_NON_EXITED_THREADS (tp
)
3108 /* Ignore the current thread here. It's handled
3113 /* Ignore threads of processes we're not resuming. */
3114 if (!ptid_match (tp
->ptid
, resume_ptid
))
3117 if (!thread_still_needs_step_over (tp
))
3120 gdb_assert (!thread_is_in_step_over_chain (tp
));
3123 fprintf_unfiltered (gdb_stdlog
,
3124 "infrun: need to step-over [%s] first\n",
3125 target_pid_to_str (tp
->ptid
));
3127 thread_step_over_chain_enqueue (tp
);
3133 /* Enqueue the current thread last, so that we move all other
3134 threads over their breakpoints first. */
3135 if (tp
->stepping_over_breakpoint
)
3136 thread_step_over_chain_enqueue (tp
);
3138 /* If the thread isn't started, we'll still need to set its prev_pc,
3139 so that switch_back_to_stepped_thread knows the thread hasn't
3140 advanced. Must do this before resuming any thread, as in
3141 all-stop/remote, once we resume we can't send any other packet
3142 until the target stops again. */
3143 tp
->prev_pc
= regcache_read_pc (regcache
);
3145 started
= start_step_over ();
3147 if (step_over_info_valid_p ())
3149 /* Either this thread started a new in-line step over, or some
3150 other thread was already doing one. In either case, don't
3151 resume anything else until the step-over is finished. */
3153 else if (started
&& !target_is_non_stop_p ())
3155 /* A new displaced stepping sequence was started. In all-stop,
3156 we can't talk to the target anymore until it next stops. */
3158 else if (!non_stop
&& target_is_non_stop_p ())
3160 /* In all-stop, but the target is always in non-stop mode.
3161 Start all other threads that are implicitly resumed too. */
3162 ALL_NON_EXITED_THREADS (tp
)
3164 /* Ignore threads of processes we're not resuming. */
3165 if (!ptid_match (tp
->ptid
, resume_ptid
))
3171 fprintf_unfiltered (gdb_stdlog
,
3172 "infrun: proceed: [%s] resumed\n",
3173 target_pid_to_str (tp
->ptid
));
3174 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3178 if (thread_is_in_step_over_chain (tp
))
3181 fprintf_unfiltered (gdb_stdlog
,
3182 "infrun: proceed: [%s] needs step-over\n",
3183 target_pid_to_str (tp
->ptid
));
3188 fprintf_unfiltered (gdb_stdlog
,
3189 "infrun: proceed: resuming %s\n",
3190 target_pid_to_str (tp
->ptid
));
3192 reset_ecs (ecs
, tp
);
3193 switch_to_thread (tp
->ptid
);
3194 keep_going_pass_signal (ecs
);
3195 if (!ecs
->wait_some_more
)
3196 error (_("Command aborted."));
3199 else if (!tp
->resumed
&& !thread_is_in_step_over_chain (tp
))
3201 /* The thread wasn't started, and isn't queued, run it now. */
3202 reset_ecs (ecs
, tp
);
3203 switch_to_thread (tp
->ptid
);
3204 keep_going_pass_signal (ecs
);
3205 if (!ecs
->wait_some_more
)
3206 error (_("Command aborted."));
3209 discard_cleanups (old_chain
);
3211 /* Tell the event loop to wait for it to stop. If the target
3212 supports asynchronous execution, it'll do this from within
3214 if (!target_can_async_p ())
3215 mark_async_event_handler (infrun_async_inferior_event_token
);
3219 /* Start remote-debugging of a machine over a serial link. */
3222 start_remote (int from_tty
)
3224 struct inferior
*inferior
;
3226 inferior
= current_inferior ();
3227 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3229 /* Always go on waiting for the target, regardless of the mode. */
3230 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3231 indicate to wait_for_inferior that a target should timeout if
3232 nothing is returned (instead of just blocking). Because of this,
3233 targets expecting an immediate response need to, internally, set
3234 things up so that the target_wait() is forced to eventually
3236 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3237 differentiate to its caller what the state of the target is after
3238 the initial open has been performed. Here we're assuming that
3239 the target has stopped. It should be possible to eventually have
3240 target_open() return to the caller an indication that the target
3241 is currently running and GDB state should be set to the same as
3242 for an async run. */
3243 wait_for_inferior ();
3245 /* Now that the inferior has stopped, do any bookkeeping like
3246 loading shared libraries. We want to do this before normal_stop,
3247 so that the displayed frame is up to date. */
3248 post_create_inferior (¤t_target
, from_tty
);
3253 /* Initialize static vars when a new inferior begins. */
3256 init_wait_for_inferior (void)
3258 /* These are meaningless until the first time through wait_for_inferior. */
3260 breakpoint_init_inferior (inf_starting
);
3262 clear_proceed_status (0);
3264 target_last_wait_ptid
= minus_one_ptid
;
3266 previous_inferior_ptid
= inferior_ptid
;
3268 /* Discard any skipped inlined frames. */
3269 clear_inline_frame_state (minus_one_ptid
);
3274 static void handle_inferior_event (struct execution_control_state
*ecs
);
3276 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3277 struct execution_control_state
*ecs
);
3278 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3279 struct execution_control_state
*ecs
);
3280 static void handle_signal_stop (struct execution_control_state
*ecs
);
3281 static void check_exception_resume (struct execution_control_state
*,
3282 struct frame_info
*);
3284 static void end_stepping_range (struct execution_control_state
*ecs
);
3285 static void stop_waiting (struct execution_control_state
*ecs
);
3286 static void keep_going (struct execution_control_state
*ecs
);
3287 static void process_event_stop_test (struct execution_control_state
*ecs
);
3288 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3290 /* Callback for iterate over threads. If the thread is stopped, but
3291 the user/frontend doesn't know about that yet, go through
3292 normal_stop, as if the thread had just stopped now. ARG points at
3293 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
3294 ptid_is_pid(PTID) is true, applies to all threads of the process
3295 pointed at by PTID. Otherwise, apply only to the thread pointed by
3299 infrun_thread_stop_requested_callback (struct thread_info
*info
, void *arg
)
3301 ptid_t ptid
= * (ptid_t
*) arg
;
3303 if ((ptid_equal (info
->ptid
, ptid
)
3304 || ptid_equal (minus_one_ptid
, ptid
)
3305 || (ptid_is_pid (ptid
)
3306 && ptid_get_pid (ptid
) == ptid_get_pid (info
->ptid
)))
3307 && is_running (info
->ptid
)
3308 && !is_executing (info
->ptid
))
3310 struct cleanup
*old_chain
;
3311 struct execution_control_state ecss
;
3312 struct execution_control_state
*ecs
= &ecss
;
3314 memset (ecs
, 0, sizeof (*ecs
));
3316 old_chain
= make_cleanup_restore_current_thread ();
3318 overlay_cache_invalid
= 1;
3319 /* Flush target cache before starting to handle each event.
3320 Target was running and cache could be stale. This is just a
3321 heuristic. Running threads may modify target memory, but we
3322 don't get any event. */
3323 target_dcache_invalidate ();
3325 /* Go through handle_inferior_event/normal_stop, so we always
3326 have consistent output as if the stop event had been
3328 ecs
->ptid
= info
->ptid
;
3329 ecs
->event_thread
= info
;
3330 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
3331 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
3333 handle_inferior_event (ecs
);
3335 if (!ecs
->wait_some_more
)
3337 /* Cancel any running execution command. */
3338 thread_cancel_execution_command (info
);
3343 do_cleanups (old_chain
);
3349 /* This function is attached as a "thread_stop_requested" observer.
3350 Cleanup local state that assumed the PTID was to be resumed, and
3351 report the stop to the frontend. */
3354 infrun_thread_stop_requested (ptid_t ptid
)
3356 struct thread_info
*tp
;
3358 /* PTID was requested to stop. Remove matching threads from the
3359 step-over queue, so we don't try to resume them
3361 ALL_NON_EXITED_THREADS (tp
)
3362 if (ptid_match (tp
->ptid
, ptid
))
3364 if (thread_is_in_step_over_chain (tp
))
3365 thread_step_over_chain_remove (tp
);
3368 iterate_over_threads (infrun_thread_stop_requested_callback
, &ptid
);
3372 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3374 if (ptid_equal (target_last_wait_ptid
, tp
->ptid
))
3375 nullify_last_target_wait_ptid ();
3378 /* Delete the step resume, single-step and longjmp/exception resume
3379 breakpoints of TP. */
3382 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3384 delete_step_resume_breakpoint (tp
);
3385 delete_exception_resume_breakpoint (tp
);
3386 delete_single_step_breakpoints (tp
);
3389 /* If the target still has execution, call FUNC for each thread that
3390 just stopped. In all-stop, that's all the non-exited threads; in
3391 non-stop, that's the current thread, only. */
3393 typedef void (*for_each_just_stopped_thread_callback_func
)
3394 (struct thread_info
*tp
);
3397 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3399 if (!target_has_execution
|| ptid_equal (inferior_ptid
, null_ptid
))
3402 if (target_is_non_stop_p ())
3404 /* If in non-stop mode, only the current thread stopped. */
3405 func (inferior_thread ());
3409 struct thread_info
*tp
;
3411 /* In all-stop mode, all threads have stopped. */
3412 ALL_NON_EXITED_THREADS (tp
)
3419 /* Delete the step resume and longjmp/exception resume breakpoints of
3420 the threads that just stopped. */
3423 delete_just_stopped_threads_infrun_breakpoints (void)
3425 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3428 /* Delete the single-step breakpoints of the threads that just
3432 delete_just_stopped_threads_single_step_breakpoints (void)
3434 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3437 /* A cleanup wrapper. */
3440 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg
)
3442 delete_just_stopped_threads_infrun_breakpoints ();
3448 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3449 const struct target_waitstatus
*ws
)
3451 char *status_string
= target_waitstatus_to_string (ws
);
3452 struct ui_file
*tmp_stream
= mem_fileopen ();
3455 /* The text is split over several lines because it was getting too long.
3456 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3457 output as a unit; we want only one timestamp printed if debug_timestamp
3460 fprintf_unfiltered (tmp_stream
,
3461 "infrun: target_wait (%d.%ld.%ld",
3462 ptid_get_pid (waiton_ptid
),
3463 ptid_get_lwp (waiton_ptid
),
3464 ptid_get_tid (waiton_ptid
));
3465 if (ptid_get_pid (waiton_ptid
) != -1)
3466 fprintf_unfiltered (tmp_stream
,
3467 " [%s]", target_pid_to_str (waiton_ptid
));
3468 fprintf_unfiltered (tmp_stream
, ", status) =\n");
3469 fprintf_unfiltered (tmp_stream
,
3470 "infrun: %d.%ld.%ld [%s],\n",
3471 ptid_get_pid (result_ptid
),
3472 ptid_get_lwp (result_ptid
),
3473 ptid_get_tid (result_ptid
),
3474 target_pid_to_str (result_ptid
));
3475 fprintf_unfiltered (tmp_stream
,
3479 text
= ui_file_xstrdup (tmp_stream
, NULL
);
3481 /* This uses %s in part to handle %'s in the text, but also to avoid
3482 a gcc error: the format attribute requires a string literal. */
3483 fprintf_unfiltered (gdb_stdlog
, "%s", text
);
3485 xfree (status_string
);
3487 ui_file_delete (tmp_stream
);
3490 /* Select a thread at random, out of those which are resumed and have
3493 static struct thread_info
*
3494 random_pending_event_thread (ptid_t waiton_ptid
)
3496 struct thread_info
*event_tp
;
3498 int random_selector
;
3500 /* First see how many events we have. Count only resumed threads
3501 that have an event pending. */
3502 ALL_NON_EXITED_THREADS (event_tp
)
3503 if (ptid_match (event_tp
->ptid
, waiton_ptid
)
3504 && event_tp
->resumed
3505 && event_tp
->suspend
.waitstatus_pending_p
)
3508 if (num_events
== 0)
3511 /* Now randomly pick a thread out of those that have had events. */
3512 random_selector
= (int)
3513 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
3515 if (debug_infrun
&& num_events
> 1)
3516 fprintf_unfiltered (gdb_stdlog
,
3517 "infrun: Found %d events, selecting #%d\n",
3518 num_events
, random_selector
);
3520 /* Select the Nth thread that has had an event. */
3521 ALL_NON_EXITED_THREADS (event_tp
)
3522 if (ptid_match (event_tp
->ptid
, waiton_ptid
)
3523 && event_tp
->resumed
3524 && event_tp
->suspend
.waitstatus_pending_p
)
3525 if (random_selector
-- == 0)
3531 /* Wrapper for target_wait that first checks whether threads have
3532 pending statuses to report before actually asking the target for
3536 do_target_wait (ptid_t ptid
, struct target_waitstatus
*status
, int options
)
3539 struct thread_info
*tp
;
3541 /* First check if there is a resumed thread with a wait status
3543 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3545 tp
= random_pending_event_thread (ptid
);
3550 fprintf_unfiltered (gdb_stdlog
,
3551 "infrun: Waiting for specific thread %s.\n",
3552 target_pid_to_str (ptid
));
3554 /* We have a specific thread to check. */
3555 tp
= find_thread_ptid (ptid
);
3556 gdb_assert (tp
!= NULL
);
3557 if (!tp
->suspend
.waitstatus_pending_p
)
3562 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3563 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3565 struct regcache
*regcache
= get_thread_regcache (tp
->ptid
);
3566 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3570 pc
= regcache_read_pc (regcache
);
3572 if (pc
!= tp
->suspend
.stop_pc
)
3575 fprintf_unfiltered (gdb_stdlog
,
3576 "infrun: PC of %s changed. was=%s, now=%s\n",
3577 target_pid_to_str (tp
->ptid
),
3578 paddress (gdbarch
, tp
->prev_pc
),
3579 paddress (gdbarch
, pc
));
3582 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3585 fprintf_unfiltered (gdb_stdlog
,
3586 "infrun: previous breakpoint of %s, at %s gone\n",
3587 target_pid_to_str (tp
->ptid
),
3588 paddress (gdbarch
, pc
));
3596 fprintf_unfiltered (gdb_stdlog
,
3597 "infrun: pending event of %s cancelled.\n",
3598 target_pid_to_str (tp
->ptid
));
3600 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3601 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3611 statstr
= target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3612 fprintf_unfiltered (gdb_stdlog
,
3613 "infrun: Using pending wait status %s for %s.\n",
3615 target_pid_to_str (tp
->ptid
));
3619 /* Now that we've selected our final event LWP, un-adjust its PC
3620 if it was a software breakpoint (and the target doesn't
3621 always adjust the PC itself). */
3622 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3623 && !target_supports_stopped_by_sw_breakpoint ())
3625 struct regcache
*regcache
;
3626 struct gdbarch
*gdbarch
;
3629 regcache
= get_thread_regcache (tp
->ptid
);
3630 gdbarch
= get_regcache_arch (regcache
);
3632 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3637 pc
= regcache_read_pc (regcache
);
3638 regcache_write_pc (regcache
, pc
+ decr_pc
);
3642 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3643 *status
= tp
->suspend
.waitstatus
;
3644 tp
->suspend
.waitstatus_pending_p
= 0;
3646 /* Wake up the event loop again, until all pending events are
3648 if (target_is_async_p ())
3649 mark_async_event_handler (infrun_async_inferior_event_token
);
3653 /* But if we don't find one, we'll have to wait. */
3655 if (deprecated_target_wait_hook
)
3656 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3658 event_ptid
= target_wait (ptid
, status
, options
);
3663 /* Prepare and stabilize the inferior for detaching it. E.g.,
3664 detaching while a thread is displaced stepping is a recipe for
3665 crashing it, as nothing would readjust the PC out of the scratch
3669 prepare_for_detach (void)
3671 struct inferior
*inf
= current_inferior ();
3672 ptid_t pid_ptid
= pid_to_ptid (inf
->pid
);
3673 struct cleanup
*old_chain_1
;
3674 struct displaced_step_inferior_state
*displaced
;
3676 displaced
= get_displaced_stepping_state (inf
->pid
);
3678 /* Is any thread of this process displaced stepping? If not,
3679 there's nothing else to do. */
3680 if (displaced
== NULL
|| ptid_equal (displaced
->step_ptid
, null_ptid
))
3684 fprintf_unfiltered (gdb_stdlog
,
3685 "displaced-stepping in-process while detaching");
3687 old_chain_1
= make_cleanup_restore_integer (&inf
->detaching
);
3690 while (!ptid_equal (displaced
->step_ptid
, null_ptid
))
3692 struct cleanup
*old_chain_2
;
3693 struct execution_control_state ecss
;
3694 struct execution_control_state
*ecs
;
3697 memset (ecs
, 0, sizeof (*ecs
));
3699 overlay_cache_invalid
= 1;
3700 /* Flush target cache before starting to handle each event.
3701 Target was running and cache could be stale. This is just a
3702 heuristic. Running threads may modify target memory, but we
3703 don't get any event. */
3704 target_dcache_invalidate ();
3706 ecs
->ptid
= do_target_wait (pid_ptid
, &ecs
->ws
, 0);
3709 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3711 /* If an error happens while handling the event, propagate GDB's
3712 knowledge of the executing state to the frontend/user running
3714 old_chain_2
= make_cleanup (finish_thread_state_cleanup
,
3717 /* Now figure out what to do with the result of the result. */
3718 handle_inferior_event (ecs
);
3720 /* No error, don't finish the state yet. */
3721 discard_cleanups (old_chain_2
);
3723 /* Breakpoints and watchpoints are not installed on the target
3724 at this point, and signals are passed directly to the
3725 inferior, so this must mean the process is gone. */
3726 if (!ecs
->wait_some_more
)
3728 discard_cleanups (old_chain_1
);
3729 error (_("Program exited while detaching"));
3733 discard_cleanups (old_chain_1
);
3736 /* Wait for control to return from inferior to debugger.
3738 If inferior gets a signal, we may decide to start it up again
3739 instead of returning. That is why there is a loop in this function.
3740 When this function actually returns it means the inferior
3741 should be left stopped and GDB should read more commands. */
3744 wait_for_inferior (void)
3746 struct cleanup
*old_cleanups
;
3747 struct cleanup
*thread_state_chain
;
3751 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3754 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
,
3757 /* If an error happens while handling the event, propagate GDB's
3758 knowledge of the executing state to the frontend/user running
3760 thread_state_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
3764 struct execution_control_state ecss
;
3765 struct execution_control_state
*ecs
= &ecss
;
3766 ptid_t waiton_ptid
= minus_one_ptid
;
3768 memset (ecs
, 0, sizeof (*ecs
));
3770 overlay_cache_invalid
= 1;
3772 /* Flush target cache before starting to handle each event.
3773 Target was running and cache could be stale. This is just a
3774 heuristic. Running threads may modify target memory, but we
3775 don't get any event. */
3776 target_dcache_invalidate ();
3778 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
, 0);
3781 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3783 /* Now figure out what to do with the result of the result. */
3784 handle_inferior_event (ecs
);
3786 if (!ecs
->wait_some_more
)
3790 /* No error, don't finish the state yet. */
3791 discard_cleanups (thread_state_chain
);
3793 do_cleanups (old_cleanups
);
3796 /* Cleanup that reinstalls the readline callback handler, if the
3797 target is running in the background. If while handling the target
3798 event something triggered a secondary prompt, like e.g., a
3799 pagination prompt, we'll have removed the callback handler (see
3800 gdb_readline_wrapper_line). Need to do this as we go back to the
3801 event loop, ready to process further input. Note this has no
3802 effect if the handler hasn't actually been removed, because calling
3803 rl_callback_handler_install resets the line buffer, thus losing
3807 reinstall_readline_callback_handler_cleanup (void *arg
)
3809 if (!interpreter_async
)
3811 /* We're not going back to the top level event loop yet. Don't
3812 install the readline callback, as it'd prep the terminal,
3813 readline-style (raw, noecho) (e.g., --batch). We'll install
3814 it the next time the prompt is displayed, when we're ready
3819 if (async_command_editing_p
&& !sync_execution
)
3820 gdb_rl_callback_handler_reinstall ();
3823 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3824 that's just the event thread. In all-stop, that's all threads. */
3827 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3829 struct thread_info
*thr
= ecs
->event_thread
;
3831 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3832 thread_fsm_clean_up (thr
->thread_fsm
);
3836 ALL_NON_EXITED_THREADS (thr
)
3838 if (thr
->thread_fsm
== NULL
)
3840 if (thr
== ecs
->event_thread
)
3843 switch_to_thread (thr
->ptid
);
3844 thread_fsm_clean_up (thr
->thread_fsm
);
3847 if (ecs
->event_thread
!= NULL
)
3848 switch_to_thread (ecs
->event_thread
->ptid
);
3852 /* A cleanup that restores the execution direction to the value saved
3856 restore_execution_direction (void *arg
)
3858 enum exec_direction_kind
*save_exec_dir
= (enum exec_direction_kind
*) arg
;
3860 execution_direction
= *save_exec_dir
;
3863 /* Asynchronous version of wait_for_inferior. It is called by the
3864 event loop whenever a change of state is detected on the file
3865 descriptor corresponding to the target. It can be called more than
3866 once to complete a single execution command. In such cases we need
3867 to keep the state in a global variable ECSS. If it is the last time
3868 that this function is called for a single execution command, then
3869 report to the user that the inferior has stopped, and do the
3870 necessary cleanups. */
3873 fetch_inferior_event (void *client_data
)
3875 struct execution_control_state ecss
;
3876 struct execution_control_state
*ecs
= &ecss
;
3877 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
3878 struct cleanup
*ts_old_chain
;
3879 int was_sync
= sync_execution
;
3880 enum exec_direction_kind save_exec_dir
= execution_direction
;
3882 ptid_t waiton_ptid
= minus_one_ptid
;
3884 memset (ecs
, 0, sizeof (*ecs
));
3886 /* End up with readline processing input, if necessary. */
3887 make_cleanup (reinstall_readline_callback_handler_cleanup
, NULL
);
3889 /* We're handling a live event, so make sure we're doing live
3890 debugging. If we're looking at traceframes while the target is
3891 running, we're going to need to get back to that mode after
3892 handling the event. */
3895 make_cleanup_restore_current_traceframe ();
3896 set_current_traceframe (-1);
3900 /* In non-stop mode, the user/frontend should not notice a thread
3901 switch due to internal events. Make sure we reverse to the
3902 user selected thread and frame after handling the event and
3903 running any breakpoint commands. */
3904 make_cleanup_restore_current_thread ();
3906 overlay_cache_invalid
= 1;
3907 /* Flush target cache before starting to handle each event. Target
3908 was running and cache could be stale. This is just a heuristic.
3909 Running threads may modify target memory, but we don't get any
3911 target_dcache_invalidate ();
3913 make_cleanup (restore_execution_direction
, &save_exec_dir
);
3914 execution_direction
= target_execution_direction ();
3916 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
,
3917 target_can_async_p () ? TARGET_WNOHANG
: 0);
3920 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3922 /* If an error happens while handling the event, propagate GDB's
3923 knowledge of the executing state to the frontend/user running
3925 if (!target_is_non_stop_p ())
3926 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
3928 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &ecs
->ptid
);
3930 /* Get executed before make_cleanup_restore_current_thread above to apply
3931 still for the thread which has thrown the exception. */
3932 make_bpstat_clear_actions_cleanup ();
3934 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
, NULL
);
3936 /* Now figure out what to do with the result of the result. */
3937 handle_inferior_event (ecs
);
3939 if (!ecs
->wait_some_more
)
3941 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3942 int should_stop
= 1;
3943 struct thread_info
*thr
= ecs
->event_thread
;
3944 int should_notify_stop
= 1;
3946 delete_just_stopped_threads_infrun_breakpoints ();
3950 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3952 if (thread_fsm
!= NULL
)
3953 should_stop
= thread_fsm_should_stop (thread_fsm
);
3962 clean_up_just_stopped_threads_fsms (ecs
);
3964 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3967 = thread_fsm_should_notify_stop (thr
->thread_fsm
);
3970 if (should_notify_stop
)
3974 /* We may not find an inferior if this was a process exit. */
3975 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3976 proceeded
= normal_stop ();
3980 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3987 /* No error, don't finish the thread states yet. */
3988 discard_cleanups (ts_old_chain
);
3990 /* Revert thread and frame. */
3991 do_cleanups (old_chain
);
3993 /* If the inferior was in sync execution mode, and now isn't,
3994 restore the prompt (a synchronous execution command has finished,
3995 and we're ready for input). */
3996 if (interpreter_async
&& was_sync
&& !sync_execution
)
3997 observer_notify_sync_execution_done ();
4001 && exec_done_display_p
4002 && (ptid_equal (inferior_ptid
, null_ptid
)
4003 || !is_running (inferior_ptid
)))
4004 printf_unfiltered (_("completed.\n"));
4007 /* Record the frame and location we're currently stepping through. */
4009 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
4011 struct thread_info
*tp
= inferior_thread ();
4013 tp
->control
.step_frame_id
= get_frame_id (frame
);
4014 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4016 tp
->current_symtab
= sal
.symtab
;
4017 tp
->current_line
= sal
.line
;
4020 /* Clear context switchable stepping state. */
4023 init_thread_stepping_state (struct thread_info
*tss
)
4025 tss
->stepped_breakpoint
= 0;
4026 tss
->stepping_over_breakpoint
= 0;
4027 tss
->stepping_over_watchpoint
= 0;
4028 tss
->step_after_step_resume_breakpoint
= 0;
4031 /* Set the cached copy of the last ptid/waitstatus. */
4034 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
4036 target_last_wait_ptid
= ptid
;
4037 target_last_waitstatus
= status
;
4040 /* Return the cached copy of the last pid/waitstatus returned by
4041 target_wait()/deprecated_target_wait_hook(). The data is actually
4042 cached by handle_inferior_event(), which gets called immediately
4043 after target_wait()/deprecated_target_wait_hook(). */
4046 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
4048 *ptidp
= target_last_wait_ptid
;
4049 *status
= target_last_waitstatus
;
4053 nullify_last_target_wait_ptid (void)
4055 target_last_wait_ptid
= minus_one_ptid
;
4058 /* Switch thread contexts. */
4061 context_switch (ptid_t ptid
)
4063 if (debug_infrun
&& !ptid_equal (ptid
, inferior_ptid
))
4065 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4066 target_pid_to_str (inferior_ptid
));
4067 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4068 target_pid_to_str (ptid
));
4071 switch_to_thread (ptid
);
4074 /* If the target can't tell whether we've hit breakpoints
4075 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4076 check whether that could have been caused by a breakpoint. If so,
4077 adjust the PC, per gdbarch_decr_pc_after_break. */
4080 adjust_pc_after_break (struct thread_info
*thread
,
4081 struct target_waitstatus
*ws
)
4083 struct regcache
*regcache
;
4084 struct gdbarch
*gdbarch
;
4085 struct address_space
*aspace
;
4086 CORE_ADDR breakpoint_pc
, decr_pc
;
4088 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4089 we aren't, just return.
4091 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4092 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4093 implemented by software breakpoints should be handled through the normal
4096 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4097 different signals (SIGILL or SIGEMT for instance), but it is less
4098 clear where the PC is pointing afterwards. It may not match
4099 gdbarch_decr_pc_after_break. I don't know any specific target that
4100 generates these signals at breakpoints (the code has been in GDB since at
4101 least 1992) so I can not guess how to handle them here.
4103 In earlier versions of GDB, a target with
4104 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4105 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4106 target with both of these set in GDB history, and it seems unlikely to be
4107 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4109 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4112 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4115 /* In reverse execution, when a breakpoint is hit, the instruction
4116 under it has already been de-executed. The reported PC always
4117 points at the breakpoint address, so adjusting it further would
4118 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4121 B1 0x08000000 : INSN1
4122 B2 0x08000001 : INSN2
4124 PC -> 0x08000003 : INSN4
4126 Say you're stopped at 0x08000003 as above. Reverse continuing
4127 from that point should hit B2 as below. Reading the PC when the
4128 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4129 been de-executed already.
4131 B1 0x08000000 : INSN1
4132 B2 PC -> 0x08000001 : INSN2
4136 We can't apply the same logic as for forward execution, because
4137 we would wrongly adjust the PC to 0x08000000, since there's a
4138 breakpoint at PC - 1. We'd then report a hit on B1, although
4139 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4141 if (execution_direction
== EXEC_REVERSE
)
4144 /* If the target can tell whether the thread hit a SW breakpoint,
4145 trust it. Targets that can tell also adjust the PC
4147 if (target_supports_stopped_by_sw_breakpoint ())
4150 /* Note that relying on whether a breakpoint is planted in memory to
4151 determine this can fail. E.g,. the breakpoint could have been
4152 removed since. Or the thread could have been told to step an
4153 instruction the size of a breakpoint instruction, and only
4154 _after_ was a breakpoint inserted at its address. */
4156 /* If this target does not decrement the PC after breakpoints, then
4157 we have nothing to do. */
4158 regcache
= get_thread_regcache (thread
->ptid
);
4159 gdbarch
= get_regcache_arch (regcache
);
4161 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4165 aspace
= get_regcache_aspace (regcache
);
4167 /* Find the location where (if we've hit a breakpoint) the
4168 breakpoint would be. */
4169 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4171 /* If the target can't tell whether a software breakpoint triggered,
4172 fallback to figuring it out based on breakpoints we think were
4173 inserted in the target, and on whether the thread was stepped or
4176 /* Check whether there actually is a software breakpoint inserted at
4179 If in non-stop mode, a race condition is possible where we've
4180 removed a breakpoint, but stop events for that breakpoint were
4181 already queued and arrive later. To suppress those spurious
4182 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4183 and retire them after a number of stop events are reported. Note
4184 this is an heuristic and can thus get confused. The real fix is
4185 to get the "stopped by SW BP and needs adjustment" info out of
4186 the target/kernel (and thus never reach here; see above). */
4187 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4188 || (target_is_non_stop_p ()
4189 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4191 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, NULL
);
4193 if (record_full_is_used ())
4194 record_full_gdb_operation_disable_set ();
4196 /* When using hardware single-step, a SIGTRAP is reported for both
4197 a completed single-step and a software breakpoint. Need to
4198 differentiate between the two, as the latter needs adjusting
4199 but the former does not.
4201 The SIGTRAP can be due to a completed hardware single-step only if
4202 - we didn't insert software single-step breakpoints
4203 - this thread is currently being stepped
4205 If any of these events did not occur, we must have stopped due
4206 to hitting a software breakpoint, and have to back up to the
4209 As a special case, we could have hardware single-stepped a
4210 software breakpoint. In this case (prev_pc == breakpoint_pc),
4211 we also need to back up to the breakpoint address. */
4213 if (thread_has_single_step_breakpoints_set (thread
)
4214 || !currently_stepping (thread
)
4215 || (thread
->stepped_breakpoint
4216 && thread
->prev_pc
== breakpoint_pc
))
4217 regcache_write_pc (regcache
, breakpoint_pc
);
4219 do_cleanups (old_cleanups
);
4224 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4226 for (frame
= get_prev_frame (frame
);
4228 frame
= get_prev_frame (frame
))
4230 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4232 if (get_frame_type (frame
) != INLINE_FRAME
)
4239 /* Auxiliary function that handles syscall entry/return events.
4240 It returns 1 if the inferior should keep going (and GDB
4241 should ignore the event), or 0 if the event deserves to be
4245 handle_syscall_event (struct execution_control_state
*ecs
)
4247 struct regcache
*regcache
;
4250 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4251 context_switch (ecs
->ptid
);
4253 regcache
= get_thread_regcache (ecs
->ptid
);
4254 syscall_number
= ecs
->ws
.value
.syscall_number
;
4255 stop_pc
= regcache_read_pc (regcache
);
4257 if (catch_syscall_enabled () > 0
4258 && catching_syscall_number (syscall_number
) > 0)
4261 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4264 ecs
->event_thread
->control
.stop_bpstat
4265 = bpstat_stop_status (get_regcache_aspace (regcache
),
4266 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4268 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4270 /* Catchpoint hit. */
4275 /* If no catchpoint triggered for this, then keep going. */
4280 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4283 fill_in_stop_func (struct gdbarch
*gdbarch
,
4284 struct execution_control_state
*ecs
)
4286 if (!ecs
->stop_func_filled_in
)
4288 /* Don't care about return value; stop_func_start and stop_func_name
4289 will both be 0 if it doesn't work. */
4290 find_pc_partial_function (stop_pc
, &ecs
->stop_func_name
,
4291 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
4292 ecs
->stop_func_start
4293 += gdbarch_deprecated_function_start_offset (gdbarch
);
4295 if (gdbarch_skip_entrypoint_p (gdbarch
))
4296 ecs
->stop_func_start
= gdbarch_skip_entrypoint (gdbarch
,
4297 ecs
->stop_func_start
);
4299 ecs
->stop_func_filled_in
= 1;
4304 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4306 static enum stop_kind
4307 get_inferior_stop_soon (ptid_t ptid
)
4309 struct inferior
*inf
= find_inferior_ptid (ptid
);
4311 gdb_assert (inf
!= NULL
);
4312 return inf
->control
.stop_soon
;
4315 /* Wait for one event. Store the resulting waitstatus in WS, and
4316 return the event ptid. */
4319 wait_one (struct target_waitstatus
*ws
)
4322 ptid_t wait_ptid
= minus_one_ptid
;
4324 overlay_cache_invalid
= 1;
4326 /* Flush target cache before starting to handle each event.
4327 Target was running and cache could be stale. This is just a
4328 heuristic. Running threads may modify target memory, but we
4329 don't get any event. */
4330 target_dcache_invalidate ();
4332 if (deprecated_target_wait_hook
)
4333 event_ptid
= deprecated_target_wait_hook (wait_ptid
, ws
, 0);
4335 event_ptid
= target_wait (wait_ptid
, ws
, 0);
4338 print_target_wait_results (wait_ptid
, event_ptid
, ws
);
4343 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4344 instead of the current thread. */
4345 #define THREAD_STOPPED_BY(REASON) \
4347 thread_stopped_by_ ## REASON (ptid_t ptid) \
4349 struct cleanup *old_chain; \
4352 old_chain = save_inferior_ptid (); \
4353 inferior_ptid = ptid; \
4355 res = target_stopped_by_ ## REASON (); \
4357 do_cleanups (old_chain); \
4362 /* Generate thread_stopped_by_watchpoint. */
4363 THREAD_STOPPED_BY (watchpoint
)
4364 /* Generate thread_stopped_by_sw_breakpoint. */
4365 THREAD_STOPPED_BY (sw_breakpoint
)
4366 /* Generate thread_stopped_by_hw_breakpoint. */
4367 THREAD_STOPPED_BY (hw_breakpoint
)
4369 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4372 switch_to_thread_cleanup (void *ptid_p
)
4374 ptid_t ptid
= *(ptid_t
*) ptid_p
;
4376 switch_to_thread (ptid
);
4379 /* Save the thread's event and stop reason to process it later. */
4382 save_waitstatus (struct thread_info
*tp
, struct target_waitstatus
*ws
)
4384 struct regcache
*regcache
;
4385 struct address_space
*aspace
;
4391 statstr
= target_waitstatus_to_string (ws
);
4392 fprintf_unfiltered (gdb_stdlog
,
4393 "infrun: saving status %s for %d.%ld.%ld\n",
4395 ptid_get_pid (tp
->ptid
),
4396 ptid_get_lwp (tp
->ptid
),
4397 ptid_get_tid (tp
->ptid
));
4401 /* Record for later. */
4402 tp
->suspend
.waitstatus
= *ws
;
4403 tp
->suspend
.waitstatus_pending_p
= 1;
4405 regcache
= get_thread_regcache (tp
->ptid
);
4406 aspace
= get_regcache_aspace (regcache
);
4408 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4409 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4411 CORE_ADDR pc
= regcache_read_pc (regcache
);
4413 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4415 if (thread_stopped_by_watchpoint (tp
->ptid
))
4417 tp
->suspend
.stop_reason
4418 = TARGET_STOPPED_BY_WATCHPOINT
;
4420 else if (target_supports_stopped_by_sw_breakpoint ()
4421 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4423 tp
->suspend
.stop_reason
4424 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4426 else if (target_supports_stopped_by_hw_breakpoint ()
4427 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4429 tp
->suspend
.stop_reason
4430 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4432 else if (!target_supports_stopped_by_hw_breakpoint ()
4433 && hardware_breakpoint_inserted_here_p (aspace
,
4436 tp
->suspend
.stop_reason
4437 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4439 else if (!target_supports_stopped_by_sw_breakpoint ()
4440 && software_breakpoint_inserted_here_p (aspace
,
4443 tp
->suspend
.stop_reason
4444 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4446 else if (!thread_has_single_step_breakpoints_set (tp
)
4447 && currently_stepping (tp
))
4449 tp
->suspend
.stop_reason
4450 = TARGET_STOPPED_BY_SINGLE_STEP
;
4455 /* A cleanup that disables thread create/exit events. */
4458 disable_thread_events (void *arg
)
4460 target_thread_events (0);
4466 stop_all_threads (void)
4468 /* We may need multiple passes to discover all threads. */
4472 struct cleanup
*old_chain
;
4474 gdb_assert (target_is_non_stop_p ());
4477 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4479 entry_ptid
= inferior_ptid
;
4480 old_chain
= make_cleanup (switch_to_thread_cleanup
, &entry_ptid
);
4482 target_thread_events (1);
4483 make_cleanup (disable_thread_events
, NULL
);
4485 /* Request threads to stop, and then wait for the stops. Because
4486 threads we already know about can spawn more threads while we're
4487 trying to stop them, and we only learn about new threads when we
4488 update the thread list, do this in a loop, and keep iterating
4489 until two passes find no threads that need to be stopped. */
4490 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4493 fprintf_unfiltered (gdb_stdlog
,
4494 "infrun: stop_all_threads, pass=%d, "
4495 "iterations=%d\n", pass
, iterations
);
4499 struct target_waitstatus ws
;
4501 struct thread_info
*t
;
4503 update_thread_list ();
4505 /* Go through all threads looking for threads that we need
4506 to tell the target to stop. */
4507 ALL_NON_EXITED_THREADS (t
)
4511 /* If already stopping, don't request a stop again.
4512 We just haven't seen the notification yet. */
4513 if (!t
->stop_requested
)
4516 fprintf_unfiltered (gdb_stdlog
,
4517 "infrun: %s executing, "
4519 target_pid_to_str (t
->ptid
));
4520 target_stop (t
->ptid
);
4521 t
->stop_requested
= 1;
4526 fprintf_unfiltered (gdb_stdlog
,
4527 "infrun: %s executing, "
4528 "already stopping\n",
4529 target_pid_to_str (t
->ptid
));
4532 if (t
->stop_requested
)
4538 fprintf_unfiltered (gdb_stdlog
,
4539 "infrun: %s not executing\n",
4540 target_pid_to_str (t
->ptid
));
4542 /* The thread may be not executing, but still be
4543 resumed with a pending status to process. */
4551 /* If we find new threads on the second iteration, restart
4552 over. We want to see two iterations in a row with all
4557 event_ptid
= wait_one (&ws
);
4558 if (ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4560 /* All resumed threads exited. */
4562 else if (ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4563 || ws
.kind
== TARGET_WAITKIND_EXITED
4564 || ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4568 ptid_t ptid
= pid_to_ptid (ws
.value
.integer
);
4570 fprintf_unfiltered (gdb_stdlog
,
4571 "infrun: %s exited while "
4572 "stopping threads\n",
4573 target_pid_to_str (ptid
));
4578 struct inferior
*inf
;
4580 t
= find_thread_ptid (event_ptid
);
4582 t
= add_thread (event_ptid
);
4584 t
->stop_requested
= 0;
4587 t
->control
.may_range_step
= 0;
4589 /* This may be the first time we see the inferior report
4591 inf
= find_inferior_ptid (event_ptid
);
4592 if (inf
->needs_setup
)
4594 switch_to_thread_no_regs (t
);
4598 if (ws
.kind
== TARGET_WAITKIND_STOPPED
4599 && ws
.value
.sig
== GDB_SIGNAL_0
)
4601 /* We caught the event that we intended to catch, so
4602 there's no event pending. */
4603 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4604 t
->suspend
.waitstatus_pending_p
= 0;
4606 if (displaced_step_fixup (t
->ptid
, GDB_SIGNAL_0
) < 0)
4608 /* Add it back to the step-over queue. */
4611 fprintf_unfiltered (gdb_stdlog
,
4612 "infrun: displaced-step of %s "
4613 "canceled: adding back to the "
4614 "step-over queue\n",
4615 target_pid_to_str (t
->ptid
));
4617 t
->control
.trap_expected
= 0;
4618 thread_step_over_chain_enqueue (t
);
4623 enum gdb_signal sig
;
4624 struct regcache
*regcache
;
4625 struct address_space
*aspace
;
4631 statstr
= target_waitstatus_to_string (&ws
);
4632 fprintf_unfiltered (gdb_stdlog
,
4633 "infrun: target_wait %s, saving "
4634 "status for %d.%ld.%ld\n",
4636 ptid_get_pid (t
->ptid
),
4637 ptid_get_lwp (t
->ptid
),
4638 ptid_get_tid (t
->ptid
));
4642 /* Record for later. */
4643 save_waitstatus (t
, &ws
);
4645 sig
= (ws
.kind
== TARGET_WAITKIND_STOPPED
4646 ? ws
.value
.sig
: GDB_SIGNAL_0
);
4648 if (displaced_step_fixup (t
->ptid
, sig
) < 0)
4650 /* Add it back to the step-over queue. */
4651 t
->control
.trap_expected
= 0;
4652 thread_step_over_chain_enqueue (t
);
4655 regcache
= get_thread_regcache (t
->ptid
);
4656 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4660 fprintf_unfiltered (gdb_stdlog
,
4661 "infrun: saved stop_pc=%s for %s "
4662 "(currently_stepping=%d)\n",
4663 paddress (target_gdbarch (),
4664 t
->suspend
.stop_pc
),
4665 target_pid_to_str (t
->ptid
),
4666 currently_stepping (t
));
4673 do_cleanups (old_chain
);
4676 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4679 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4682 handle_no_resumed (struct execution_control_state
*ecs
)
4684 struct inferior
*inf
;
4685 struct thread_info
*thread
;
4687 if (target_can_async_p () && !sync_execution
)
4689 /* There were no unwaited-for children left in the target, but,
4690 we're not synchronously waiting for events either. Just
4694 fprintf_unfiltered (gdb_stdlog
,
4695 "infrun: TARGET_WAITKIND_NO_RESUMED " "(ignoring: bg)\n");
4696 prepare_to_wait (ecs
);
4700 /* Otherwise, if we were running a synchronous execution command, we
4701 may need to cancel it and give the user back the terminal.
4703 In non-stop mode, the target can't tell whether we've already
4704 consumed previous stop events, so it can end up sending us a
4705 no-resumed event like so:
4707 #0 - thread 1 is left stopped
4709 #1 - thread 2 is resumed and hits breakpoint
4710 -> TARGET_WAITKIND_STOPPED
4712 #2 - thread 3 is resumed and exits
4713 this is the last resumed thread, so
4714 -> TARGET_WAITKIND_NO_RESUMED
4716 #3 - gdb processes stop for thread 2 and decides to re-resume
4719 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4720 thread 2 is now resumed, so the event should be ignored.
4722 IOW, if the stop for thread 2 doesn't end a foreground command,
4723 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4724 event. But it could be that the event meant that thread 2 itself
4725 (or whatever other thread was the last resumed thread) exited.
4727 To address this we refresh the thread list and check whether we
4728 have resumed threads _now_. In the example above, this removes
4729 thread 3 from the thread list. If thread 2 was re-resumed, we
4730 ignore this event. If we find no thread resumed, then we cancel
4731 the synchronous command show "no unwaited-for " to the user. */
4732 update_thread_list ();
4734 ALL_NON_EXITED_THREADS (thread
)
4736 if (thread
->executing
4737 || thread
->suspend
.waitstatus_pending_p
)
4739 /* There were no unwaited-for children left in the target at
4740 some point, but there are now. Just ignore. */
4742 fprintf_unfiltered (gdb_stdlog
,
4743 "infrun: TARGET_WAITKIND_NO_RESUMED "
4744 "(ignoring: found resumed)\n");
4745 prepare_to_wait (ecs
);
4750 /* Note however that we may find no resumed thread because the whole
4751 process exited meanwhile (thus updating the thread list results
4752 in an empty thread list). In this case we know we'll be getting
4753 a process exit event shortly. */
4759 thread
= any_live_thread_of_process (inf
->pid
);
4763 fprintf_unfiltered (gdb_stdlog
,
4764 "infrun: TARGET_WAITKIND_NO_RESUMED "
4765 "(expect process exit)\n");
4766 prepare_to_wait (ecs
);
4771 /* Go ahead and report the event. */
4775 /* Given an execution control state that has been freshly filled in by
4776 an event from the inferior, figure out what it means and take
4779 The alternatives are:
4781 1) stop_waiting and return; to really stop and return to the
4784 2) keep_going and return; to wait for the next event (set
4785 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4789 handle_inferior_event_1 (struct execution_control_state
*ecs
)
4791 enum stop_kind stop_soon
;
4793 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4795 /* We had an event in the inferior, but we are not interested in
4796 handling it at this level. The lower layers have already
4797 done what needs to be done, if anything.
4799 One of the possible circumstances for this is when the
4800 inferior produces output for the console. The inferior has
4801 not stopped, and we are ignoring the event. Another possible
4802 circumstance is any event which the lower level knows will be
4803 reported multiple times without an intervening resume. */
4805 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
4806 prepare_to_wait (ecs
);
4810 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4813 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4814 prepare_to_wait (ecs
);
4818 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4819 && handle_no_resumed (ecs
))
4822 /* Cache the last pid/waitstatus. */
4823 set_last_target_status (ecs
->ptid
, ecs
->ws
);
4825 /* Always clear state belonging to the previous time we stopped. */
4826 stop_stack_dummy
= STOP_NONE
;
4828 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4830 /* No unwaited-for children left. IOW, all resumed children
4833 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4835 stop_print_frame
= 0;
4840 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
4841 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
4843 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
4844 /* If it's a new thread, add it to the thread database. */
4845 if (ecs
->event_thread
== NULL
)
4846 ecs
->event_thread
= add_thread (ecs
->ptid
);
4848 /* Disable range stepping. If the next step request could use a
4849 range, this will be end up re-enabled then. */
4850 ecs
->event_thread
->control
.may_range_step
= 0;
4853 /* Dependent on valid ECS->EVENT_THREAD. */
4854 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
4856 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4857 reinit_frame_cache ();
4859 breakpoint_retire_moribund ();
4861 /* First, distinguish signals caused by the debugger from signals
4862 that have to do with the program's own actions. Note that
4863 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4864 on the operating system version. Here we detect when a SIGILL or
4865 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4866 something similar for SIGSEGV, since a SIGSEGV will be generated
4867 when we're trying to execute a breakpoint instruction on a
4868 non-executable stack. This happens for call dummy breakpoints
4869 for architectures like SPARC that place call dummies on the
4871 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
4872 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
4873 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
4874 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
4876 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
4878 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
4879 regcache_read_pc (regcache
)))
4882 fprintf_unfiltered (gdb_stdlog
,
4883 "infrun: Treating signal as SIGTRAP\n");
4884 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
4888 /* Mark the non-executing threads accordingly. In all-stop, all
4889 threads of all processes are stopped when we get any event
4890 reported. In non-stop mode, only the event thread stops. */
4894 if (!target_is_non_stop_p ())
4895 mark_ptid
= minus_one_ptid
;
4896 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
4897 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4899 /* If we're handling a process exit in non-stop mode, even
4900 though threads haven't been deleted yet, one would think
4901 that there is nothing to do, as threads of the dead process
4902 will be soon deleted, and threads of any other process were
4903 left running. However, on some targets, threads survive a
4904 process exit event. E.g., for the "checkpoint" command,
4905 when the current checkpoint/fork exits, linux-fork.c
4906 automatically switches to another fork from within
4907 target_mourn_inferior, by associating the same
4908 inferior/thread to another fork. We haven't mourned yet at
4909 this point, but we must mark any threads left in the
4910 process as not-executing so that finish_thread_state marks
4911 them stopped (in the user's perspective) if/when we present
4912 the stop to the user. */
4913 mark_ptid
= pid_to_ptid (ptid_get_pid (ecs
->ptid
));
4916 mark_ptid
= ecs
->ptid
;
4918 set_executing (mark_ptid
, 0);
4920 /* Likewise the resumed flag. */
4921 set_resumed (mark_ptid
, 0);
4924 switch (ecs
->ws
.kind
)
4926 case TARGET_WAITKIND_LOADED
:
4928 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
4929 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4930 context_switch (ecs
->ptid
);
4931 /* Ignore gracefully during startup of the inferior, as it might
4932 be the shell which has just loaded some objects, otherwise
4933 add the symbols for the newly loaded objects. Also ignore at
4934 the beginning of an attach or remote session; we will query
4935 the full list of libraries once the connection is
4938 stop_soon
= get_inferior_stop_soon (ecs
->ptid
);
4939 if (stop_soon
== NO_STOP_QUIETLY
)
4941 struct regcache
*regcache
;
4943 regcache
= get_thread_regcache (ecs
->ptid
);
4945 handle_solib_event ();
4947 ecs
->event_thread
->control
.stop_bpstat
4948 = bpstat_stop_status (get_regcache_aspace (regcache
),
4949 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4951 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4953 /* A catchpoint triggered. */
4954 process_event_stop_test (ecs
);
4958 /* If requested, stop when the dynamic linker notifies
4959 gdb of events. This allows the user to get control
4960 and place breakpoints in initializer routines for
4961 dynamically loaded objects (among other things). */
4962 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4963 if (stop_on_solib_events
)
4965 /* Make sure we print "Stopped due to solib-event" in
4967 stop_print_frame
= 1;
4974 /* If we are skipping through a shell, or through shared library
4975 loading that we aren't interested in, resume the program. If
4976 we're running the program normally, also resume. */
4977 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
4979 /* Loading of shared libraries might have changed breakpoint
4980 addresses. Make sure new breakpoints are inserted. */
4981 if (stop_soon
== NO_STOP_QUIETLY
)
4982 insert_breakpoints ();
4983 resume (GDB_SIGNAL_0
);
4984 prepare_to_wait (ecs
);
4988 /* But stop if we're attaching or setting up a remote
4990 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4991 || stop_soon
== STOP_QUIETLY_REMOTE
)
4994 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4999 internal_error (__FILE__
, __LINE__
,
5000 _("unhandled stop_soon: %d"), (int) stop_soon
);
5002 case TARGET_WAITKIND_SPURIOUS
:
5004 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5005 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5006 context_switch (ecs
->ptid
);
5007 resume (GDB_SIGNAL_0
);
5008 prepare_to_wait (ecs
);
5011 case TARGET_WAITKIND_THREAD_CREATED
:
5013 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5014 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5015 context_switch (ecs
->ptid
);
5016 if (!switch_back_to_stepped_thread (ecs
))
5020 case TARGET_WAITKIND_EXITED
:
5021 case TARGET_WAITKIND_SIGNALLED
:
5024 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5025 fprintf_unfiltered (gdb_stdlog
,
5026 "infrun: TARGET_WAITKIND_EXITED\n");
5028 fprintf_unfiltered (gdb_stdlog
,
5029 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5032 inferior_ptid
= ecs
->ptid
;
5033 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
5034 set_current_program_space (current_inferior ()->pspace
);
5035 handle_vfork_child_exec_or_exit (0);
5036 target_terminal_ours (); /* Must do this before mourn anyway. */
5038 /* Clearing any previous state of convenience variables. */
5039 clear_exit_convenience_vars ();
5041 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5043 /* Record the exit code in the convenience variable $_exitcode, so
5044 that the user can inspect this again later. */
5045 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5046 (LONGEST
) ecs
->ws
.value
.integer
);
5048 /* Also record this in the inferior itself. */
5049 current_inferior ()->has_exit_code
= 1;
5050 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5052 /* Support the --return-child-result option. */
5053 return_child_result_value
= ecs
->ws
.value
.integer
;
5055 observer_notify_exited (ecs
->ws
.value
.integer
);
5059 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
5060 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
5062 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5064 /* Set the value of the internal variable $_exitsignal,
5065 which holds the signal uncaught by the inferior. */
5066 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5067 gdbarch_gdb_signal_to_target (gdbarch
,
5068 ecs
->ws
.value
.sig
));
5072 /* We don't have access to the target's method used for
5073 converting between signal numbers (GDB's internal
5074 representation <-> target's representation).
5075 Therefore, we cannot do a good job at displaying this
5076 information to the user. It's better to just warn
5077 her about it (if infrun debugging is enabled), and
5080 fprintf_filtered (gdb_stdlog
, _("\
5081 Cannot fill $_exitsignal with the correct signal number.\n"));
5084 observer_notify_signal_exited (ecs
->ws
.value
.sig
);
5087 gdb_flush (gdb_stdout
);
5088 target_mourn_inferior ();
5089 stop_print_frame
= 0;
5093 /* The following are the only cases in which we keep going;
5094 the above cases end in a continue or goto. */
5095 case TARGET_WAITKIND_FORKED
:
5096 case TARGET_WAITKIND_VFORKED
:
5099 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5100 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
5102 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_VFORKED\n");
5105 /* Check whether the inferior is displaced stepping. */
5107 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
5108 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
5110 /* If checking displaced stepping is supported, and thread
5111 ecs->ptid is displaced stepping. */
5112 if (displaced_step_in_progress_thread (ecs
->ptid
))
5114 struct inferior
*parent_inf
5115 = find_inferior_ptid (ecs
->ptid
);
5116 struct regcache
*child_regcache
;
5117 CORE_ADDR parent_pc
;
5119 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5120 indicating that the displaced stepping of syscall instruction
5121 has been done. Perform cleanup for parent process here. Note
5122 that this operation also cleans up the child process for vfork,
5123 because their pages are shared. */
5124 displaced_step_fixup (ecs
->ptid
, GDB_SIGNAL_TRAP
);
5125 /* Start a new step-over in another thread if there's one
5129 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5131 struct displaced_step_inferior_state
*displaced
5132 = get_displaced_stepping_state (ptid_get_pid (ecs
->ptid
));
5134 /* Restore scratch pad for child process. */
5135 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5138 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5139 the child's PC is also within the scratchpad. Set the child's PC
5140 to the parent's PC value, which has already been fixed up.
5141 FIXME: we use the parent's aspace here, although we're touching
5142 the child, because the child hasn't been added to the inferior
5143 list yet at this point. */
5146 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
5148 parent_inf
->aspace
);
5149 /* Read PC value of parent process. */
5150 parent_pc
= regcache_read_pc (regcache
);
5152 if (debug_displaced
)
5153 fprintf_unfiltered (gdb_stdlog
,
5154 "displaced: write child pc from %s to %s\n",
5156 regcache_read_pc (child_regcache
)),
5157 paddress (gdbarch
, parent_pc
));
5159 regcache_write_pc (child_regcache
, parent_pc
);
5163 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5164 context_switch (ecs
->ptid
);
5166 /* Immediately detach breakpoints from the child before there's
5167 any chance of letting the user delete breakpoints from the
5168 breakpoint lists. If we don't do this early, it's easy to
5169 leave left over traps in the child, vis: "break foo; catch
5170 fork; c; <fork>; del; c; <child calls foo>". We only follow
5171 the fork on the last `continue', and by that time the
5172 breakpoint at "foo" is long gone from the breakpoint table.
5173 If we vforked, then we don't need to unpatch here, since both
5174 parent and child are sharing the same memory pages; we'll
5175 need to unpatch at follow/detach time instead to be certain
5176 that new breakpoints added between catchpoint hit time and
5177 vfork follow are detached. */
5178 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5180 /* This won't actually modify the breakpoint list, but will
5181 physically remove the breakpoints from the child. */
5182 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5185 delete_just_stopped_threads_single_step_breakpoints ();
5187 /* In case the event is caught by a catchpoint, remember that
5188 the event is to be followed at the next resume of the thread,
5189 and not immediately. */
5190 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5192 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5194 ecs
->event_thread
->control
.stop_bpstat
5195 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5196 stop_pc
, ecs
->ptid
, &ecs
->ws
);
5198 /* If no catchpoint triggered for this, then keep going. Note
5199 that we're interested in knowing the bpstat actually causes a
5200 stop, not just if it may explain the signal. Software
5201 watchpoints, for example, always appear in the bpstat. */
5202 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5208 = (follow_fork_mode_string
== follow_fork_mode_child
);
5210 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5212 should_resume
= follow_fork ();
5215 child
= ecs
->ws
.value
.related_pid
;
5217 /* At this point, the parent is marked running, and the
5218 child is marked stopped. */
5220 /* If not resuming the parent, mark it stopped. */
5221 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5222 set_running (parent
, 0);
5224 /* If resuming the child, mark it running. */
5225 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5226 set_running (child
, 1);
5228 /* In non-stop mode, also resume the other branch. */
5229 if (!detach_fork
&& (non_stop
5230 || (sched_multi
&& target_is_non_stop_p ())))
5233 switch_to_thread (parent
);
5235 switch_to_thread (child
);
5237 ecs
->event_thread
= inferior_thread ();
5238 ecs
->ptid
= inferior_ptid
;
5243 switch_to_thread (child
);
5245 switch_to_thread (parent
);
5247 ecs
->event_thread
= inferior_thread ();
5248 ecs
->ptid
= inferior_ptid
;
5256 process_event_stop_test (ecs
);
5259 case TARGET_WAITKIND_VFORK_DONE
:
5260 /* Done with the shared memory region. Re-insert breakpoints in
5261 the parent, and keep going. */
5264 fprintf_unfiltered (gdb_stdlog
,
5265 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5267 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5268 context_switch (ecs
->ptid
);
5270 current_inferior ()->waiting_for_vfork_done
= 0;
5271 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5272 /* This also takes care of reinserting breakpoints in the
5273 previously locked inferior. */
5277 case TARGET_WAITKIND_EXECD
:
5279 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
5281 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5282 context_switch (ecs
->ptid
);
5284 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5286 /* Do whatever is necessary to the parent branch of the vfork. */
5287 handle_vfork_child_exec_or_exit (1);
5289 /* This causes the eventpoints and symbol table to be reset.
5290 Must do this now, before trying to determine whether to
5292 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5294 /* In follow_exec we may have deleted the original thread and
5295 created a new one. Make sure that the event thread is the
5296 execd thread for that case (this is a nop otherwise). */
5297 ecs
->event_thread
= inferior_thread ();
5299 ecs
->event_thread
->control
.stop_bpstat
5300 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5301 stop_pc
, ecs
->ptid
, &ecs
->ws
);
5303 /* Note that this may be referenced from inside
5304 bpstat_stop_status above, through inferior_has_execd. */
5305 xfree (ecs
->ws
.value
.execd_pathname
);
5306 ecs
->ws
.value
.execd_pathname
= NULL
;
5308 /* If no catchpoint triggered for this, then keep going. */
5309 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5311 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5315 process_event_stop_test (ecs
);
5318 /* Be careful not to try to gather much state about a thread
5319 that's in a syscall. It's frequently a losing proposition. */
5320 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5322 fprintf_unfiltered (gdb_stdlog
,
5323 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5324 /* Getting the current syscall number. */
5325 if (handle_syscall_event (ecs
) == 0)
5326 process_event_stop_test (ecs
);
5329 /* Before examining the threads further, step this thread to
5330 get it entirely out of the syscall. (We get notice of the
5331 event when the thread is just on the verge of exiting a
5332 syscall. Stepping one instruction seems to get it back
5334 case TARGET_WAITKIND_SYSCALL_RETURN
:
5336 fprintf_unfiltered (gdb_stdlog
,
5337 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5338 if (handle_syscall_event (ecs
) == 0)
5339 process_event_stop_test (ecs
);
5342 case TARGET_WAITKIND_STOPPED
:
5344 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
5345 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5346 handle_signal_stop (ecs
);
5349 case TARGET_WAITKIND_NO_HISTORY
:
5351 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5352 /* Reverse execution: target ran out of history info. */
5354 /* Switch to the stopped thread. */
5355 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5356 context_switch (ecs
->ptid
);
5358 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5360 delete_just_stopped_threads_single_step_breakpoints ();
5361 stop_pc
= regcache_read_pc (get_thread_regcache (inferior_ptid
));
5362 observer_notify_no_history ();
5368 /* A wrapper around handle_inferior_event_1, which also makes sure
5369 that all temporary struct value objects that were created during
5370 the handling of the event get deleted at the end. */
5373 handle_inferior_event (struct execution_control_state
*ecs
)
5375 struct value
*mark
= value_mark ();
5377 handle_inferior_event_1 (ecs
);
5378 /* Purge all temporary values created during the event handling,
5379 as it could be a long time before we return to the command level
5380 where such values would otherwise be purged. */
5381 value_free_to_mark (mark
);
5384 /* Restart threads back to what they were trying to do back when we
5385 paused them for an in-line step-over. The EVENT_THREAD thread is
5389 restart_threads (struct thread_info
*event_thread
)
5391 struct thread_info
*tp
;
5392 struct thread_info
*step_over
= NULL
;
5394 /* In case the instruction just stepped spawned a new thread. */
5395 update_thread_list ();
5397 ALL_NON_EXITED_THREADS (tp
)
5399 if (tp
== event_thread
)
5402 fprintf_unfiltered (gdb_stdlog
,
5403 "infrun: restart threads: "
5404 "[%s] is event thread\n",
5405 target_pid_to_str (tp
->ptid
));
5409 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5412 fprintf_unfiltered (gdb_stdlog
,
5413 "infrun: restart threads: "
5414 "[%s] not meant to be running\n",
5415 target_pid_to_str (tp
->ptid
));
5422 fprintf_unfiltered (gdb_stdlog
,
5423 "infrun: restart threads: [%s] resumed\n",
5424 target_pid_to_str (tp
->ptid
));
5425 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5429 if (thread_is_in_step_over_chain (tp
))
5432 fprintf_unfiltered (gdb_stdlog
,
5433 "infrun: restart threads: "
5434 "[%s] needs step-over\n",
5435 target_pid_to_str (tp
->ptid
));
5436 gdb_assert (!tp
->resumed
);
5441 if (tp
->suspend
.waitstatus_pending_p
)
5444 fprintf_unfiltered (gdb_stdlog
,
5445 "infrun: restart threads: "
5446 "[%s] has pending status\n",
5447 target_pid_to_str (tp
->ptid
));
5452 /* If some thread needs to start a step-over at this point, it
5453 should still be in the step-over queue, and thus skipped
5455 if (thread_still_needs_step_over (tp
))
5457 internal_error (__FILE__
, __LINE__
,
5458 "thread [%s] needs a step-over, but not in "
5459 "step-over queue\n",
5460 target_pid_to_str (tp
->ptid
));
5463 if (currently_stepping (tp
))
5466 fprintf_unfiltered (gdb_stdlog
,
5467 "infrun: restart threads: [%s] was stepping\n",
5468 target_pid_to_str (tp
->ptid
));
5469 keep_going_stepped_thread (tp
);
5473 struct execution_control_state ecss
;
5474 struct execution_control_state
*ecs
= &ecss
;
5477 fprintf_unfiltered (gdb_stdlog
,
5478 "infrun: restart threads: [%s] continuing\n",
5479 target_pid_to_str (tp
->ptid
));
5480 reset_ecs (ecs
, tp
);
5481 switch_to_thread (tp
->ptid
);
5482 keep_going_pass_signal (ecs
);
5487 /* Callback for iterate_over_threads. Find a resumed thread that has
5488 a pending waitstatus. */
5491 resumed_thread_with_pending_status (struct thread_info
*tp
,
5495 && tp
->suspend
.waitstatus_pending_p
);
5498 /* Called when we get an event that may finish an in-line or
5499 out-of-line (displaced stepping) step-over started previously.
5500 Return true if the event is processed and we should go back to the
5501 event loop; false if the caller should continue processing the
5505 finish_step_over (struct execution_control_state
*ecs
)
5507 int had_step_over_info
;
5509 displaced_step_fixup (ecs
->ptid
,
5510 ecs
->event_thread
->suspend
.stop_signal
);
5512 had_step_over_info
= step_over_info_valid_p ();
5514 if (had_step_over_info
)
5516 /* If we're stepping over a breakpoint with all threads locked,
5517 then only the thread that was stepped should be reporting
5519 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5521 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5522 clear_step_over_info ();
5525 if (!target_is_non_stop_p ())
5528 /* Start a new step-over in another thread if there's one that
5532 /* If we were stepping over a breakpoint before, and haven't started
5533 a new in-line step-over sequence, then restart all other threads
5534 (except the event thread). We can't do this in all-stop, as then
5535 e.g., we wouldn't be able to issue any other remote packet until
5536 these other threads stop. */
5537 if (had_step_over_info
&& !step_over_info_valid_p ())
5539 struct thread_info
*pending
;
5541 /* If we only have threads with pending statuses, the restart
5542 below won't restart any thread and so nothing re-inserts the
5543 breakpoint we just stepped over. But we need it inserted
5544 when we later process the pending events, otherwise if
5545 another thread has a pending event for this breakpoint too,
5546 we'd discard its event (because the breakpoint that
5547 originally caused the event was no longer inserted). */
5548 context_switch (ecs
->ptid
);
5549 insert_breakpoints ();
5551 restart_threads (ecs
->event_thread
);
5553 /* If we have events pending, go through handle_inferior_event
5554 again, picking up a pending event at random. This avoids
5555 thread starvation. */
5557 /* But not if we just stepped over a watchpoint in order to let
5558 the instruction execute so we can evaluate its expression.
5559 The set of watchpoints that triggered is recorded in the
5560 breakpoint objects themselves (see bp->watchpoint_triggered).
5561 If we processed another event first, that other event could
5562 clobber this info. */
5563 if (ecs
->event_thread
->stepping_over_watchpoint
)
5566 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5568 if (pending
!= NULL
)
5570 struct thread_info
*tp
= ecs
->event_thread
;
5571 struct regcache
*regcache
;
5575 fprintf_unfiltered (gdb_stdlog
,
5576 "infrun: found resumed threads with "
5577 "pending events, saving status\n");
5580 gdb_assert (pending
!= tp
);
5582 /* Record the event thread's event for later. */
5583 save_waitstatus (tp
, &ecs
->ws
);
5584 /* This was cleared early, by handle_inferior_event. Set it
5585 so this pending event is considered by
5589 gdb_assert (!tp
->executing
);
5591 regcache
= get_thread_regcache (tp
->ptid
);
5592 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5596 fprintf_unfiltered (gdb_stdlog
,
5597 "infrun: saved stop_pc=%s for %s "
5598 "(currently_stepping=%d)\n",
5599 paddress (target_gdbarch (),
5600 tp
->suspend
.stop_pc
),
5601 target_pid_to_str (tp
->ptid
),
5602 currently_stepping (tp
));
5605 /* This in-line step-over finished; clear this so we won't
5606 start a new one. This is what handle_signal_stop would
5607 do, if we returned false. */
5608 tp
->stepping_over_breakpoint
= 0;
5610 /* Wake up the event loop again. */
5611 mark_async_event_handler (infrun_async_inferior_event_token
);
5613 prepare_to_wait (ecs
);
5621 /* Come here when the program has stopped with a signal. */
5624 handle_signal_stop (struct execution_control_state
*ecs
)
5626 struct frame_info
*frame
;
5627 struct gdbarch
*gdbarch
;
5628 int stopped_by_watchpoint
;
5629 enum stop_kind stop_soon
;
5632 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5634 /* Do we need to clean up the state of a thread that has
5635 completed a displaced single-step? (Doing so usually affects
5636 the PC, so do it here, before we set stop_pc.) */
5637 if (finish_step_over (ecs
))
5640 /* If we either finished a single-step or hit a breakpoint, but
5641 the user wanted this thread to be stopped, pretend we got a
5642 SIG0 (generic unsignaled stop). */
5643 if (ecs
->event_thread
->stop_requested
5644 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5645 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5647 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5651 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
5652 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
5653 struct cleanup
*old_chain
= save_inferior_ptid ();
5655 inferior_ptid
= ecs
->ptid
;
5657 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5658 paddress (gdbarch
, stop_pc
));
5659 if (target_stopped_by_watchpoint ())
5663 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5665 if (target_stopped_data_address (¤t_target
, &addr
))
5666 fprintf_unfiltered (gdb_stdlog
,
5667 "infrun: stopped data address = %s\n",
5668 paddress (gdbarch
, addr
));
5670 fprintf_unfiltered (gdb_stdlog
,
5671 "infrun: (no data address available)\n");
5674 do_cleanups (old_chain
);
5677 /* This is originated from start_remote(), start_inferior() and
5678 shared libraries hook functions. */
5679 stop_soon
= get_inferior_stop_soon (ecs
->ptid
);
5680 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5682 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5683 context_switch (ecs
->ptid
);
5685 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5686 stop_print_frame
= 1;
5691 /* This originates from attach_command(). We need to overwrite
5692 the stop_signal here, because some kernels don't ignore a
5693 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5694 See more comments in inferior.h. On the other hand, if we
5695 get a non-SIGSTOP, report it to the user - assume the backend
5696 will handle the SIGSTOP if it should show up later.
5698 Also consider that the attach is complete when we see a
5699 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5700 target extended-remote report it instead of a SIGSTOP
5701 (e.g. gdbserver). We already rely on SIGTRAP being our
5702 signal, so this is no exception.
5704 Also consider that the attach is complete when we see a
5705 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5706 the target to stop all threads of the inferior, in case the
5707 low level attach operation doesn't stop them implicitly. If
5708 they weren't stopped implicitly, then the stub will report a
5709 GDB_SIGNAL_0, meaning: stopped for no particular reason
5710 other than GDB's request. */
5711 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5712 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5713 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5714 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5716 stop_print_frame
= 1;
5718 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5722 /* See if something interesting happened to the non-current thread. If
5723 so, then switch to that thread. */
5724 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5727 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5729 context_switch (ecs
->ptid
);
5731 if (deprecated_context_hook
)
5732 deprecated_context_hook (ptid_to_global_thread_id (ecs
->ptid
));
5735 /* At this point, get hold of the now-current thread's frame. */
5736 frame
= get_current_frame ();
5737 gdbarch
= get_frame_arch (frame
);
5739 /* Pull the single step breakpoints out of the target. */
5740 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5742 struct regcache
*regcache
;
5743 struct address_space
*aspace
;
5746 regcache
= get_thread_regcache (ecs
->ptid
);
5747 aspace
= get_regcache_aspace (regcache
);
5748 pc
= regcache_read_pc (regcache
);
5750 /* However, before doing so, if this single-step breakpoint was
5751 actually for another thread, set this thread up for moving
5753 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5756 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5760 fprintf_unfiltered (gdb_stdlog
,
5761 "infrun: [%s] hit another thread's "
5762 "single-step breakpoint\n",
5763 target_pid_to_str (ecs
->ptid
));
5765 ecs
->hit_singlestep_breakpoint
= 1;
5772 fprintf_unfiltered (gdb_stdlog
,
5773 "infrun: [%s] hit its "
5774 "single-step breakpoint\n",
5775 target_pid_to_str (ecs
->ptid
));
5779 delete_just_stopped_threads_single_step_breakpoints ();
5781 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5782 && ecs
->event_thread
->control
.trap_expected
5783 && ecs
->event_thread
->stepping_over_watchpoint
)
5784 stopped_by_watchpoint
= 0;
5786 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5788 /* If necessary, step over this watchpoint. We'll be back to display
5790 if (stopped_by_watchpoint
5791 && (target_have_steppable_watchpoint
5792 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5794 /* At this point, we are stopped at an instruction which has
5795 attempted to write to a piece of memory under control of
5796 a watchpoint. The instruction hasn't actually executed
5797 yet. If we were to evaluate the watchpoint expression
5798 now, we would get the old value, and therefore no change
5799 would seem to have occurred.
5801 In order to make watchpoints work `right', we really need
5802 to complete the memory write, and then evaluate the
5803 watchpoint expression. We do this by single-stepping the
5806 It may not be necessary to disable the watchpoint to step over
5807 it. For example, the PA can (with some kernel cooperation)
5808 single step over a watchpoint without disabling the watchpoint.
5810 It is far more common to need to disable a watchpoint to step
5811 the inferior over it. If we have non-steppable watchpoints,
5812 we must disable the current watchpoint; it's simplest to
5813 disable all watchpoints.
5815 Any breakpoint at PC must also be stepped over -- if there's
5816 one, it will have already triggered before the watchpoint
5817 triggered, and we either already reported it to the user, or
5818 it didn't cause a stop and we called keep_going. In either
5819 case, if there was a breakpoint at PC, we must be trying to
5821 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5826 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5827 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5828 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5829 ecs
->event_thread
->control
.stop_step
= 0;
5830 stop_print_frame
= 1;
5831 stopped_by_random_signal
= 0;
5833 /* Hide inlined functions starting here, unless we just performed stepi or
5834 nexti. After stepi and nexti, always show the innermost frame (not any
5835 inline function call sites). */
5836 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5838 struct address_space
*aspace
=
5839 get_regcache_aspace (get_thread_regcache (ecs
->ptid
));
5841 /* skip_inline_frames is expensive, so we avoid it if we can
5842 determine that the address is one where functions cannot have
5843 been inlined. This improves performance with inferiors that
5844 load a lot of shared libraries, because the solib event
5845 breakpoint is defined as the address of a function (i.e. not
5846 inline). Note that we have to check the previous PC as well
5847 as the current one to catch cases when we have just
5848 single-stepped off a breakpoint prior to reinstating it.
5849 Note that we're assuming that the code we single-step to is
5850 not inline, but that's not definitive: there's nothing
5851 preventing the event breakpoint function from containing
5852 inlined code, and the single-step ending up there. If the
5853 user had set a breakpoint on that inlined code, the missing
5854 skip_inline_frames call would break things. Fortunately
5855 that's an extremely unlikely scenario. */
5856 if (!pc_at_non_inline_function (aspace
, stop_pc
, &ecs
->ws
)
5857 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5858 && ecs
->event_thread
->control
.trap_expected
5859 && pc_at_non_inline_function (aspace
,
5860 ecs
->event_thread
->prev_pc
,
5863 skip_inline_frames (ecs
->ptid
);
5865 /* Re-fetch current thread's frame in case that invalidated
5867 frame
= get_current_frame ();
5868 gdbarch
= get_frame_arch (frame
);
5872 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5873 && ecs
->event_thread
->control
.trap_expected
5874 && gdbarch_single_step_through_delay_p (gdbarch
)
5875 && currently_stepping (ecs
->event_thread
))
5877 /* We're trying to step off a breakpoint. Turns out that we're
5878 also on an instruction that needs to be stepped multiple
5879 times before it's been fully executing. E.g., architectures
5880 with a delay slot. It needs to be stepped twice, once for
5881 the instruction and once for the delay slot. */
5882 int step_through_delay
5883 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5885 if (debug_infrun
&& step_through_delay
)
5886 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
5887 if (ecs
->event_thread
->control
.step_range_end
== 0
5888 && step_through_delay
)
5890 /* The user issued a continue when stopped at a breakpoint.
5891 Set up for another trap and get out of here. */
5892 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5896 else if (step_through_delay
)
5898 /* The user issued a step when stopped at a breakpoint.
5899 Maybe we should stop, maybe we should not - the delay
5900 slot *might* correspond to a line of source. In any
5901 case, don't decide that here, just set
5902 ecs->stepping_over_breakpoint, making sure we
5903 single-step again before breakpoints are re-inserted. */
5904 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5908 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5909 handles this event. */
5910 ecs
->event_thread
->control
.stop_bpstat
5911 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5912 stop_pc
, ecs
->ptid
, &ecs
->ws
);
5914 /* Following in case break condition called a
5916 stop_print_frame
= 1;
5918 /* This is where we handle "moribund" watchpoints. Unlike
5919 software breakpoints traps, hardware watchpoint traps are
5920 always distinguishable from random traps. If no high-level
5921 watchpoint is associated with the reported stop data address
5922 anymore, then the bpstat does not explain the signal ---
5923 simply make sure to ignore it if `stopped_by_watchpoint' is
5927 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5928 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5930 && stopped_by_watchpoint
)
5931 fprintf_unfiltered (gdb_stdlog
,
5932 "infrun: no user watchpoint explains "
5933 "watchpoint SIGTRAP, ignoring\n");
5935 /* NOTE: cagney/2003-03-29: These checks for a random signal
5936 at one stage in the past included checks for an inferior
5937 function call's call dummy's return breakpoint. The original
5938 comment, that went with the test, read:
5940 ``End of a stack dummy. Some systems (e.g. Sony news) give
5941 another signal besides SIGTRAP, so check here as well as
5944 If someone ever tries to get call dummys on a
5945 non-executable stack to work (where the target would stop
5946 with something like a SIGSEGV), then those tests might need
5947 to be re-instated. Given, however, that the tests were only
5948 enabled when momentary breakpoints were not being used, I
5949 suspect that it won't be the case.
5951 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5952 be necessary for call dummies on a non-executable stack on
5955 /* See if the breakpoints module can explain the signal. */
5957 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5958 ecs
->event_thread
->suspend
.stop_signal
);
5960 /* Maybe this was a trap for a software breakpoint that has since
5962 if (random_signal
&& target_stopped_by_sw_breakpoint ())
5964 if (program_breakpoint_here_p (gdbarch
, stop_pc
))
5966 struct regcache
*regcache
;
5969 /* Re-adjust PC to what the program would see if GDB was not
5971 regcache
= get_thread_regcache (ecs
->event_thread
->ptid
);
5972 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
5975 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, NULL
);
5977 if (record_full_is_used ())
5978 record_full_gdb_operation_disable_set ();
5980 regcache_write_pc (regcache
, stop_pc
+ decr_pc
);
5982 do_cleanups (old_cleanups
);
5987 /* A delayed software breakpoint event. Ignore the trap. */
5989 fprintf_unfiltered (gdb_stdlog
,
5990 "infrun: delayed software breakpoint "
5991 "trap, ignoring\n");
5996 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5997 has since been removed. */
5998 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6000 /* A delayed hardware breakpoint event. Ignore the trap. */
6002 fprintf_unfiltered (gdb_stdlog
,
6003 "infrun: delayed hardware breakpoint/watchpoint "
6004 "trap, ignoring\n");
6008 /* If not, perhaps stepping/nexting can. */
6010 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6011 && currently_stepping (ecs
->event_thread
));
6013 /* Perhaps the thread hit a single-step breakpoint of _another_
6014 thread. Single-step breakpoints are transparent to the
6015 breakpoints module. */
6017 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6019 /* No? Perhaps we got a moribund watchpoint. */
6021 random_signal
= !stopped_by_watchpoint
;
6023 /* For the program's own signals, act according to
6024 the signal handling tables. */
6028 /* Signal not for debugging purposes. */
6029 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
6030 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6033 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6034 gdb_signal_to_symbol_string (stop_signal
));
6036 stopped_by_random_signal
= 1;
6038 /* Always stop on signals if we're either just gaining control
6039 of the program, or the user explicitly requested this thread
6040 to remain stopped. */
6041 if (stop_soon
!= NO_STOP_QUIETLY
6042 || ecs
->event_thread
->stop_requested
6044 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6050 /* Notify observers the signal has "handle print" set. Note we
6051 returned early above if stopping; normal_stop handles the
6052 printing in that case. */
6053 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6055 /* The signal table tells us to print about this signal. */
6056 target_terminal_ours_for_output ();
6057 observer_notify_signal_received (ecs
->event_thread
->suspend
.stop_signal
);
6058 target_terminal_inferior ();
6061 /* Clear the signal if it should not be passed. */
6062 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6063 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6065 if (ecs
->event_thread
->prev_pc
== stop_pc
6066 && ecs
->event_thread
->control
.trap_expected
6067 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6071 /* We were just starting a new sequence, attempting to
6072 single-step off of a breakpoint and expecting a SIGTRAP.
6073 Instead this signal arrives. This signal will take us out
6074 of the stepping range so GDB needs to remember to, when
6075 the signal handler returns, resume stepping off that
6077 /* To simplify things, "continue" is forced to use the same
6078 code paths as single-step - set a breakpoint at the
6079 signal return address and then, once hit, step off that
6082 fprintf_unfiltered (gdb_stdlog
,
6083 "infrun: signal arrived while stepping over "
6086 was_in_line
= step_over_info_valid_p ();
6087 clear_step_over_info ();
6088 insert_hp_step_resume_breakpoint_at_frame (frame
);
6089 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6090 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6091 ecs
->event_thread
->control
.trap_expected
= 0;
6093 if (target_is_non_stop_p ())
6095 /* Either "set non-stop" is "on", or the target is
6096 always in non-stop mode. In this case, we have a bit
6097 more work to do. Resume the current thread, and if
6098 we had paused all threads, restart them while the
6099 signal handler runs. */
6104 restart_threads (ecs
->event_thread
);
6106 else if (debug_infrun
)
6108 fprintf_unfiltered (gdb_stdlog
,
6109 "infrun: no need to restart threads\n");
6114 /* If we were nexting/stepping some other thread, switch to
6115 it, so that we don't continue it, losing control. */
6116 if (!switch_back_to_stepped_thread (ecs
))
6121 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6122 && (pc_in_thread_step_range (stop_pc
, ecs
->event_thread
)
6123 || ecs
->event_thread
->control
.step_range_end
== 1)
6124 && frame_id_eq (get_stack_frame_id (frame
),
6125 ecs
->event_thread
->control
.step_stack_frame_id
)
6126 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6128 /* The inferior is about to take a signal that will take it
6129 out of the single step range. Set a breakpoint at the
6130 current PC (which is presumably where the signal handler
6131 will eventually return) and then allow the inferior to
6134 Note that this is only needed for a signal delivered
6135 while in the single-step range. Nested signals aren't a
6136 problem as they eventually all return. */
6138 fprintf_unfiltered (gdb_stdlog
,
6139 "infrun: signal may take us out of "
6140 "single-step range\n");
6142 clear_step_over_info ();
6143 insert_hp_step_resume_breakpoint_at_frame (frame
);
6144 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6145 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6146 ecs
->event_thread
->control
.trap_expected
= 0;
6151 /* Note: step_resume_breakpoint may be non-NULL. This occures
6152 when either there's a nested signal, or when there's a
6153 pending signal enabled just as the signal handler returns
6154 (leaving the inferior at the step-resume-breakpoint without
6155 actually executing it). Either way continue until the
6156 breakpoint is really hit. */
6158 if (!switch_back_to_stepped_thread (ecs
))
6161 fprintf_unfiltered (gdb_stdlog
,
6162 "infrun: random signal, keep going\n");
6169 process_event_stop_test (ecs
);
6172 /* Come here when we've got some debug event / signal we can explain
6173 (IOW, not a random signal), and test whether it should cause a
6174 stop, or whether we should resume the inferior (transparently).
6175 E.g., could be a breakpoint whose condition evaluates false; we
6176 could be still stepping within the line; etc. */
6179 process_event_stop_test (struct execution_control_state
*ecs
)
6181 struct symtab_and_line stop_pc_sal
;
6182 struct frame_info
*frame
;
6183 struct gdbarch
*gdbarch
;
6184 CORE_ADDR jmp_buf_pc
;
6185 struct bpstat_what what
;
6187 /* Handle cases caused by hitting a breakpoint. */
6189 frame
= get_current_frame ();
6190 gdbarch
= get_frame_arch (frame
);
6192 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6194 if (what
.call_dummy
)
6196 stop_stack_dummy
= what
.call_dummy
;
6199 /* A few breakpoint types have callbacks associated (e.g.,
6200 bp_jit_event). Run them now. */
6201 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6203 /* If we hit an internal event that triggers symbol changes, the
6204 current frame will be invalidated within bpstat_what (e.g., if we
6205 hit an internal solib event). Re-fetch it. */
6206 frame
= get_current_frame ();
6207 gdbarch
= get_frame_arch (frame
);
6209 switch (what
.main_action
)
6211 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6212 /* If we hit the breakpoint at longjmp while stepping, we
6213 install a momentary breakpoint at the target of the
6217 fprintf_unfiltered (gdb_stdlog
,
6218 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6220 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6222 if (what
.is_longjmp
)
6224 struct value
*arg_value
;
6226 /* If we set the longjmp breakpoint via a SystemTap probe,
6227 then use it to extract the arguments. The destination PC
6228 is the third argument to the probe. */
6229 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6232 jmp_buf_pc
= value_as_address (arg_value
);
6233 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6235 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6236 || !gdbarch_get_longjmp_target (gdbarch
,
6237 frame
, &jmp_buf_pc
))
6240 fprintf_unfiltered (gdb_stdlog
,
6241 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6242 "(!gdbarch_get_longjmp_target)\n");
6247 /* Insert a breakpoint at resume address. */
6248 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6251 check_exception_resume (ecs
, frame
);
6255 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6257 struct frame_info
*init_frame
;
6259 /* There are several cases to consider.
6261 1. The initiating frame no longer exists. In this case we
6262 must stop, because the exception or longjmp has gone too
6265 2. The initiating frame exists, and is the same as the
6266 current frame. We stop, because the exception or longjmp
6269 3. The initiating frame exists and is different from the
6270 current frame. This means the exception or longjmp has
6271 been caught beneath the initiating frame, so keep going.
6273 4. longjmp breakpoint has been placed just to protect
6274 against stale dummy frames and user is not interested in
6275 stopping around longjmps. */
6278 fprintf_unfiltered (gdb_stdlog
,
6279 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6281 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6283 delete_exception_resume_breakpoint (ecs
->event_thread
);
6285 if (what
.is_longjmp
)
6287 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6289 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6297 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6301 struct frame_id current_id
6302 = get_frame_id (get_current_frame ());
6303 if (frame_id_eq (current_id
,
6304 ecs
->event_thread
->initiating_frame
))
6306 /* Case 2. Fall through. */
6316 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6318 delete_step_resume_breakpoint (ecs
->event_thread
);
6320 end_stepping_range (ecs
);
6324 case BPSTAT_WHAT_SINGLE
:
6326 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6327 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6328 /* Still need to check other stuff, at least the case where we
6329 are stepping and step out of the right range. */
6332 case BPSTAT_WHAT_STEP_RESUME
:
6334 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6336 delete_step_resume_breakpoint (ecs
->event_thread
);
6337 if (ecs
->event_thread
->control
.proceed_to_finish
6338 && execution_direction
== EXEC_REVERSE
)
6340 struct thread_info
*tp
= ecs
->event_thread
;
6342 /* We are finishing a function in reverse, and just hit the
6343 step-resume breakpoint at the start address of the
6344 function, and we're almost there -- just need to back up
6345 by one more single-step, which should take us back to the
6347 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6351 fill_in_stop_func (gdbarch
, ecs
);
6352 if (stop_pc
== ecs
->stop_func_start
6353 && execution_direction
== EXEC_REVERSE
)
6355 /* We are stepping over a function call in reverse, and just
6356 hit the step-resume breakpoint at the start address of
6357 the function. Go back to single-stepping, which should
6358 take us back to the function call. */
6359 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6365 case BPSTAT_WHAT_STOP_NOISY
:
6367 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6368 stop_print_frame
= 1;
6370 /* Assume the thread stopped for a breapoint. We'll still check
6371 whether a/the breakpoint is there when the thread is next
6373 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6378 case BPSTAT_WHAT_STOP_SILENT
:
6380 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6381 stop_print_frame
= 0;
6383 /* Assume the thread stopped for a breapoint. We'll still check
6384 whether a/the breakpoint is there when the thread is next
6386 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6390 case BPSTAT_WHAT_HP_STEP_RESUME
:
6392 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6394 delete_step_resume_breakpoint (ecs
->event_thread
);
6395 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6397 /* Back when the step-resume breakpoint was inserted, we
6398 were trying to single-step off a breakpoint. Go back to
6400 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6401 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6407 case BPSTAT_WHAT_KEEP_CHECKING
:
6411 /* If we stepped a permanent breakpoint and we had a high priority
6412 step-resume breakpoint for the address we stepped, but we didn't
6413 hit it, then we must have stepped into the signal handler. The
6414 step-resume was only necessary to catch the case of _not_
6415 stepping into the handler, so delete it, and fall through to
6416 checking whether the step finished. */
6417 if (ecs
->event_thread
->stepped_breakpoint
)
6419 struct breakpoint
*sr_bp
6420 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6423 && sr_bp
->loc
->permanent
6424 && sr_bp
->type
== bp_hp_step_resume
6425 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6428 fprintf_unfiltered (gdb_stdlog
,
6429 "infrun: stepped permanent breakpoint, stopped in "
6431 delete_step_resume_breakpoint (ecs
->event_thread
);
6432 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6436 /* We come here if we hit a breakpoint but should not stop for it.
6437 Possibly we also were stepping and should stop for that. So fall
6438 through and test for stepping. But, if not stepping, do not
6441 /* In all-stop mode, if we're currently stepping but have stopped in
6442 some other thread, we need to switch back to the stepped thread. */
6443 if (switch_back_to_stepped_thread (ecs
))
6446 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6449 fprintf_unfiltered (gdb_stdlog
,
6450 "infrun: step-resume breakpoint is inserted\n");
6452 /* Having a step-resume breakpoint overrides anything
6453 else having to do with stepping commands until
6454 that breakpoint is reached. */
6459 if (ecs
->event_thread
->control
.step_range_end
== 0)
6462 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6463 /* Likewise if we aren't even stepping. */
6468 /* Re-fetch current thread's frame in case the code above caused
6469 the frame cache to be re-initialized, making our FRAME variable
6470 a dangling pointer. */
6471 frame
= get_current_frame ();
6472 gdbarch
= get_frame_arch (frame
);
6473 fill_in_stop_func (gdbarch
, ecs
);
6475 /* If stepping through a line, keep going if still within it.
6477 Note that step_range_end is the address of the first instruction
6478 beyond the step range, and NOT the address of the last instruction
6481 Note also that during reverse execution, we may be stepping
6482 through a function epilogue and therefore must detect when
6483 the current-frame changes in the middle of a line. */
6485 if (pc_in_thread_step_range (stop_pc
, ecs
->event_thread
)
6486 && (execution_direction
!= EXEC_REVERSE
6487 || frame_id_eq (get_frame_id (frame
),
6488 ecs
->event_thread
->control
.step_frame_id
)))
6492 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6493 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6494 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6496 /* Tentatively re-enable range stepping; `resume' disables it if
6497 necessary (e.g., if we're stepping over a breakpoint or we
6498 have software watchpoints). */
6499 ecs
->event_thread
->control
.may_range_step
= 1;
6501 /* When stepping backward, stop at beginning of line range
6502 (unless it's the function entry point, in which case
6503 keep going back to the call point). */
6504 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6505 && stop_pc
!= ecs
->stop_func_start
6506 && execution_direction
== EXEC_REVERSE
)
6507 end_stepping_range (ecs
);
6514 /* We stepped out of the stepping range. */
6516 /* If we are stepping at the source level and entered the runtime
6517 loader dynamic symbol resolution code...
6519 EXEC_FORWARD: we keep on single stepping until we exit the run
6520 time loader code and reach the callee's address.
6522 EXEC_REVERSE: we've already executed the callee (backward), and
6523 the runtime loader code is handled just like any other
6524 undebuggable function call. Now we need only keep stepping
6525 backward through the trampoline code, and that's handled further
6526 down, so there is nothing for us to do here. */
6528 if (execution_direction
!= EXEC_REVERSE
6529 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6530 && in_solib_dynsym_resolve_code (stop_pc
))
6532 CORE_ADDR pc_after_resolver
=
6533 gdbarch_skip_solib_resolver (gdbarch
, stop_pc
);
6536 fprintf_unfiltered (gdb_stdlog
,
6537 "infrun: stepped into dynsym resolve code\n");
6539 if (pc_after_resolver
)
6541 /* Set up a step-resume breakpoint at the address
6542 indicated by SKIP_SOLIB_RESOLVER. */
6543 struct symtab_and_line sr_sal
;
6546 sr_sal
.pc
= pc_after_resolver
;
6547 sr_sal
.pspace
= get_frame_program_space (frame
);
6549 insert_step_resume_breakpoint_at_sal (gdbarch
,
6550 sr_sal
, null_frame_id
);
6557 if (ecs
->event_thread
->control
.step_range_end
!= 1
6558 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6559 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6560 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6563 fprintf_unfiltered (gdb_stdlog
,
6564 "infrun: stepped into signal trampoline\n");
6565 /* The inferior, while doing a "step" or "next", has ended up in
6566 a signal trampoline (either by a signal being delivered or by
6567 the signal handler returning). Just single-step until the
6568 inferior leaves the trampoline (either by calling the handler
6574 /* If we're in the return path from a shared library trampoline,
6575 we want to proceed through the trampoline when stepping. */
6576 /* macro/2012-04-25: This needs to come before the subroutine
6577 call check below as on some targets return trampolines look
6578 like subroutine calls (MIPS16 return thunks). */
6579 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6580 stop_pc
, ecs
->stop_func_name
)
6581 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6583 /* Determine where this trampoline returns. */
6584 CORE_ADDR real_stop_pc
;
6586 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6589 fprintf_unfiltered (gdb_stdlog
,
6590 "infrun: stepped into solib return tramp\n");
6592 /* Only proceed through if we know where it's going. */
6595 /* And put the step-breakpoint there and go until there. */
6596 struct symtab_and_line sr_sal
;
6598 init_sal (&sr_sal
); /* initialize to zeroes */
6599 sr_sal
.pc
= real_stop_pc
;
6600 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6601 sr_sal
.pspace
= get_frame_program_space (frame
);
6603 /* Do not specify what the fp should be when we stop since
6604 on some machines the prologue is where the new fp value
6606 insert_step_resume_breakpoint_at_sal (gdbarch
,
6607 sr_sal
, null_frame_id
);
6609 /* Restart without fiddling with the step ranges or
6616 /* Check for subroutine calls. The check for the current frame
6617 equalling the step ID is not necessary - the check of the
6618 previous frame's ID is sufficient - but it is a common case and
6619 cheaper than checking the previous frame's ID.
6621 NOTE: frame_id_eq will never report two invalid frame IDs as
6622 being equal, so to get into this block, both the current and
6623 previous frame must have valid frame IDs. */
6624 /* The outer_frame_id check is a heuristic to detect stepping
6625 through startup code. If we step over an instruction which
6626 sets the stack pointer from an invalid value to a valid value,
6627 we may detect that as a subroutine call from the mythical
6628 "outermost" function. This could be fixed by marking
6629 outermost frames as !stack_p,code_p,special_p. Then the
6630 initial outermost frame, before sp was valid, would
6631 have code_addr == &_start. See the comment in frame_id_eq
6633 if (!frame_id_eq (get_stack_frame_id (frame
),
6634 ecs
->event_thread
->control
.step_stack_frame_id
)
6635 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6636 ecs
->event_thread
->control
.step_stack_frame_id
)
6637 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6639 || (ecs
->event_thread
->control
.step_start_function
6640 != find_pc_function (stop_pc
)))))
6642 CORE_ADDR real_stop_pc
;
6645 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6647 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6649 /* I presume that step_over_calls is only 0 when we're
6650 supposed to be stepping at the assembly language level
6651 ("stepi"). Just stop. */
6652 /* And this works the same backward as frontward. MVS */
6653 end_stepping_range (ecs
);
6657 /* Reverse stepping through solib trampolines. */
6659 if (execution_direction
== EXEC_REVERSE
6660 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6661 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6662 || (ecs
->stop_func_start
== 0
6663 && in_solib_dynsym_resolve_code (stop_pc
))))
6665 /* Any solib trampoline code can be handled in reverse
6666 by simply continuing to single-step. We have already
6667 executed the solib function (backwards), and a few
6668 steps will take us back through the trampoline to the
6674 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6676 /* We're doing a "next".
6678 Normal (forward) execution: set a breakpoint at the
6679 callee's return address (the address at which the caller
6682 Reverse (backward) execution. set the step-resume
6683 breakpoint at the start of the function that we just
6684 stepped into (backwards), and continue to there. When we
6685 get there, we'll need to single-step back to the caller. */
6687 if (execution_direction
== EXEC_REVERSE
)
6689 /* If we're already at the start of the function, we've either
6690 just stepped backward into a single instruction function,
6691 or stepped back out of a signal handler to the first instruction
6692 of the function. Just keep going, which will single-step back
6694 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6696 struct symtab_and_line sr_sal
;
6698 /* Normal function call return (static or dynamic). */
6700 sr_sal
.pc
= ecs
->stop_func_start
;
6701 sr_sal
.pspace
= get_frame_program_space (frame
);
6702 insert_step_resume_breakpoint_at_sal (gdbarch
,
6703 sr_sal
, null_frame_id
);
6707 insert_step_resume_breakpoint_at_caller (frame
);
6713 /* If we are in a function call trampoline (a stub between the
6714 calling routine and the real function), locate the real
6715 function. That's what tells us (a) whether we want to step
6716 into it at all, and (b) what prologue we want to run to the
6717 end of, if we do step into it. */
6718 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6719 if (real_stop_pc
== 0)
6720 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6721 if (real_stop_pc
!= 0)
6722 ecs
->stop_func_start
= real_stop_pc
;
6724 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6726 struct symtab_and_line sr_sal
;
6729 sr_sal
.pc
= ecs
->stop_func_start
;
6730 sr_sal
.pspace
= get_frame_program_space (frame
);
6732 insert_step_resume_breakpoint_at_sal (gdbarch
,
6733 sr_sal
, null_frame_id
);
6738 /* If we have line number information for the function we are
6739 thinking of stepping into and the function isn't on the skip
6742 If there are several symtabs at that PC (e.g. with include
6743 files), just want to know whether *any* of them have line
6744 numbers. find_pc_line handles this. */
6746 struct symtab_and_line tmp_sal
;
6748 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6749 if (tmp_sal
.line
!= 0
6750 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6753 if (execution_direction
== EXEC_REVERSE
)
6754 handle_step_into_function_backward (gdbarch
, ecs
);
6756 handle_step_into_function (gdbarch
, ecs
);
6761 /* If we have no line number and the step-stop-if-no-debug is
6762 set, we stop the step so that the user has a chance to switch
6763 in assembly mode. */
6764 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6765 && step_stop_if_no_debug
)
6767 end_stepping_range (ecs
);
6771 if (execution_direction
== EXEC_REVERSE
)
6773 /* If we're already at the start of the function, we've either just
6774 stepped backward into a single instruction function without line
6775 number info, or stepped back out of a signal handler to the first
6776 instruction of the function without line number info. Just keep
6777 going, which will single-step back to the caller. */
6778 if (ecs
->stop_func_start
!= stop_pc
)
6780 /* Set a breakpoint at callee's start address.
6781 From there we can step once and be back in the caller. */
6782 struct symtab_and_line sr_sal
;
6785 sr_sal
.pc
= ecs
->stop_func_start
;
6786 sr_sal
.pspace
= get_frame_program_space (frame
);
6787 insert_step_resume_breakpoint_at_sal (gdbarch
,
6788 sr_sal
, null_frame_id
);
6792 /* Set a breakpoint at callee's return address (the address
6793 at which the caller will resume). */
6794 insert_step_resume_breakpoint_at_caller (frame
);
6800 /* Reverse stepping through solib trampolines. */
6802 if (execution_direction
== EXEC_REVERSE
6803 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6805 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6806 || (ecs
->stop_func_start
== 0
6807 && in_solib_dynsym_resolve_code (stop_pc
)))
6809 /* Any solib trampoline code can be handled in reverse
6810 by simply continuing to single-step. We have already
6811 executed the solib function (backwards), and a few
6812 steps will take us back through the trampoline to the
6817 else if (in_solib_dynsym_resolve_code (stop_pc
))
6819 /* Stepped backward into the solib dynsym resolver.
6820 Set a breakpoint at its start and continue, then
6821 one more step will take us out. */
6822 struct symtab_and_line sr_sal
;
6825 sr_sal
.pc
= ecs
->stop_func_start
;
6826 sr_sal
.pspace
= get_frame_program_space (frame
);
6827 insert_step_resume_breakpoint_at_sal (gdbarch
,
6828 sr_sal
, null_frame_id
);
6834 stop_pc_sal
= find_pc_line (stop_pc
, 0);
6836 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6837 the trampoline processing logic, however, there are some trampolines
6838 that have no names, so we should do trampoline handling first. */
6839 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6840 && ecs
->stop_func_name
== NULL
6841 && stop_pc_sal
.line
== 0)
6844 fprintf_unfiltered (gdb_stdlog
,
6845 "infrun: stepped into undebuggable function\n");
6847 /* The inferior just stepped into, or returned to, an
6848 undebuggable function (where there is no debugging information
6849 and no line number corresponding to the address where the
6850 inferior stopped). Since we want to skip this kind of code,
6851 we keep going until the inferior returns from this
6852 function - unless the user has asked us not to (via
6853 set step-mode) or we no longer know how to get back
6854 to the call site. */
6855 if (step_stop_if_no_debug
6856 || !frame_id_p (frame_unwind_caller_id (frame
)))
6858 /* If we have no line number and the step-stop-if-no-debug
6859 is set, we stop the step so that the user has a chance to
6860 switch in assembly mode. */
6861 end_stepping_range (ecs
);
6866 /* Set a breakpoint at callee's return address (the address
6867 at which the caller will resume). */
6868 insert_step_resume_breakpoint_at_caller (frame
);
6874 if (ecs
->event_thread
->control
.step_range_end
== 1)
6876 /* It is stepi or nexti. We always want to stop stepping after
6879 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
6880 end_stepping_range (ecs
);
6884 if (stop_pc_sal
.line
== 0)
6886 /* We have no line number information. That means to stop
6887 stepping (does this always happen right after one instruction,
6888 when we do "s" in a function with no line numbers,
6889 or can this happen as a result of a return or longjmp?). */
6891 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
6892 end_stepping_range (ecs
);
6896 /* Look for "calls" to inlined functions, part one. If the inline
6897 frame machinery detected some skipped call sites, we have entered
6898 a new inline function. */
6900 if (frame_id_eq (get_frame_id (get_current_frame ()),
6901 ecs
->event_thread
->control
.step_frame_id
)
6902 && inline_skipped_frames (ecs
->ptid
))
6904 struct symtab_and_line call_sal
;
6907 fprintf_unfiltered (gdb_stdlog
,
6908 "infrun: stepped into inlined function\n");
6910 find_frame_sal (get_current_frame (), &call_sal
);
6912 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6914 /* For "step", we're going to stop. But if the call site
6915 for this inlined function is on the same source line as
6916 we were previously stepping, go down into the function
6917 first. Otherwise stop at the call site. */
6919 if (call_sal
.line
== ecs
->event_thread
->current_line
6920 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6921 step_into_inline_frame (ecs
->ptid
);
6923 end_stepping_range (ecs
);
6928 /* For "next", we should stop at the call site if it is on a
6929 different source line. Otherwise continue through the
6930 inlined function. */
6931 if (call_sal
.line
== ecs
->event_thread
->current_line
6932 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6935 end_stepping_range (ecs
);
6940 /* Look for "calls" to inlined functions, part two. If we are still
6941 in the same real function we were stepping through, but we have
6942 to go further up to find the exact frame ID, we are stepping
6943 through a more inlined call beyond its call site. */
6945 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6946 && !frame_id_eq (get_frame_id (get_current_frame ()),
6947 ecs
->event_thread
->control
.step_frame_id
)
6948 && stepped_in_from (get_current_frame (),
6949 ecs
->event_thread
->control
.step_frame_id
))
6952 fprintf_unfiltered (gdb_stdlog
,
6953 "infrun: stepping through inlined function\n");
6955 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6958 end_stepping_range (ecs
);
6962 if ((stop_pc
== stop_pc_sal
.pc
)
6963 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
6964 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
6966 /* We are at the start of a different line. So stop. Note that
6967 we don't stop if we step into the middle of a different line.
6968 That is said to make things like for (;;) statements work
6971 fprintf_unfiltered (gdb_stdlog
,
6972 "infrun: stepped to a different line\n");
6973 end_stepping_range (ecs
);
6977 /* We aren't done stepping.
6979 Optimize by setting the stepping range to the line.
6980 (We might not be in the original line, but if we entered a
6981 new line in mid-statement, we continue stepping. This makes
6982 things like for(;;) statements work better.) */
6984 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
6985 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
6986 ecs
->event_thread
->control
.may_range_step
= 1;
6987 set_step_info (frame
, stop_pc_sal
);
6990 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
6994 /* In all-stop mode, if we're currently stepping but have stopped in
6995 some other thread, we may need to switch back to the stepped
6996 thread. Returns true we set the inferior running, false if we left
6997 it stopped (and the event needs further processing). */
7000 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7002 if (!target_is_non_stop_p ())
7004 struct thread_info
*tp
;
7005 struct thread_info
*stepping_thread
;
7007 /* If any thread is blocked on some internal breakpoint, and we
7008 simply need to step over that breakpoint to get it going
7009 again, do that first. */
7011 /* However, if we see an event for the stepping thread, then we
7012 know all other threads have been moved past their breakpoints
7013 already. Let the caller check whether the step is finished,
7014 etc., before deciding to move it past a breakpoint. */
7015 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7018 /* Check if the current thread is blocked on an incomplete
7019 step-over, interrupted by a random signal. */
7020 if (ecs
->event_thread
->control
.trap_expected
7021 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7025 fprintf_unfiltered (gdb_stdlog
,
7026 "infrun: need to finish step-over of [%s]\n",
7027 target_pid_to_str (ecs
->event_thread
->ptid
));
7033 /* Check if the current thread is blocked by a single-step
7034 breakpoint of another thread. */
7035 if (ecs
->hit_singlestep_breakpoint
)
7039 fprintf_unfiltered (gdb_stdlog
,
7040 "infrun: need to step [%s] over single-step "
7042 target_pid_to_str (ecs
->ptid
));
7048 /* If this thread needs yet another step-over (e.g., stepping
7049 through a delay slot), do it first before moving on to
7051 if (thread_still_needs_step_over (ecs
->event_thread
))
7055 fprintf_unfiltered (gdb_stdlog
,
7056 "infrun: thread [%s] still needs step-over\n",
7057 target_pid_to_str (ecs
->event_thread
->ptid
));
7063 /* If scheduler locking applies even if not stepping, there's no
7064 need to walk over threads. Above we've checked whether the
7065 current thread is stepping. If some other thread not the
7066 event thread is stepping, then it must be that scheduler
7067 locking is not in effect. */
7068 if (schedlock_applies (ecs
->event_thread
))
7071 /* Otherwise, we no longer expect a trap in the current thread.
7072 Clear the trap_expected flag before switching back -- this is
7073 what keep_going does as well, if we call it. */
7074 ecs
->event_thread
->control
.trap_expected
= 0;
7076 /* Likewise, clear the signal if it should not be passed. */
7077 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7078 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7080 /* Do all pending step-overs before actually proceeding with
7082 if (start_step_over ())
7084 prepare_to_wait (ecs
);
7088 /* Look for the stepping/nexting thread. */
7089 stepping_thread
= NULL
;
7091 ALL_NON_EXITED_THREADS (tp
)
7093 /* Ignore threads of processes the caller is not
7096 && ptid_get_pid (tp
->ptid
) != ptid_get_pid (ecs
->ptid
))
7099 /* When stepping over a breakpoint, we lock all threads
7100 except the one that needs to move past the breakpoint.
7101 If a non-event thread has this set, the "incomplete
7102 step-over" check above should have caught it earlier. */
7103 if (tp
->control
.trap_expected
)
7105 internal_error (__FILE__
, __LINE__
,
7106 "[%s] has inconsistent state: "
7107 "trap_expected=%d\n",
7108 target_pid_to_str (tp
->ptid
),
7109 tp
->control
.trap_expected
);
7112 /* Did we find the stepping thread? */
7113 if (tp
->control
.step_range_end
)
7115 /* Yep. There should only one though. */
7116 gdb_assert (stepping_thread
== NULL
);
7118 /* The event thread is handled at the top, before we
7120 gdb_assert (tp
!= ecs
->event_thread
);
7122 /* If some thread other than the event thread is
7123 stepping, then scheduler locking can't be in effect,
7124 otherwise we wouldn't have resumed the current event
7125 thread in the first place. */
7126 gdb_assert (!schedlock_applies (tp
));
7128 stepping_thread
= tp
;
7132 if (stepping_thread
!= NULL
)
7135 fprintf_unfiltered (gdb_stdlog
,
7136 "infrun: switching back to stepped thread\n");
7138 if (keep_going_stepped_thread (stepping_thread
))
7140 prepare_to_wait (ecs
);
7149 /* Set a previously stepped thread back to stepping. Returns true on
7150 success, false if the resume is not possible (e.g., the thread
7154 keep_going_stepped_thread (struct thread_info
*tp
)
7156 struct frame_info
*frame
;
7157 struct gdbarch
*gdbarch
;
7158 struct execution_control_state ecss
;
7159 struct execution_control_state
*ecs
= &ecss
;
7161 /* If the stepping thread exited, then don't try to switch back and
7162 resume it, which could fail in several different ways depending
7163 on the target. Instead, just keep going.
7165 We can find a stepping dead thread in the thread list in two
7168 - The target supports thread exit events, and when the target
7169 tries to delete the thread from the thread list, inferior_ptid
7170 pointed at the exiting thread. In such case, calling
7171 delete_thread does not really remove the thread from the list;
7172 instead, the thread is left listed, with 'exited' state.
7174 - The target's debug interface does not support thread exit
7175 events, and so we have no idea whatsoever if the previously
7176 stepping thread is still alive. For that reason, we need to
7177 synchronously query the target now. */
7179 if (is_exited (tp
->ptid
)
7180 || !target_thread_alive (tp
->ptid
))
7183 fprintf_unfiltered (gdb_stdlog
,
7184 "infrun: not resuming previously "
7185 "stepped thread, it has vanished\n");
7187 delete_thread (tp
->ptid
);
7192 fprintf_unfiltered (gdb_stdlog
,
7193 "infrun: resuming previously stepped thread\n");
7195 reset_ecs (ecs
, tp
);
7196 switch_to_thread (tp
->ptid
);
7198 stop_pc
= regcache_read_pc (get_thread_regcache (tp
->ptid
));
7199 frame
= get_current_frame ();
7200 gdbarch
= get_frame_arch (frame
);
7202 /* If the PC of the thread we were trying to single-step has
7203 changed, then that thread has trapped or been signaled, but the
7204 event has not been reported to GDB yet. Re-poll the target
7205 looking for this particular thread's event (i.e. temporarily
7206 enable schedlock) by:
7208 - setting a break at the current PC
7209 - resuming that particular thread, only (by setting trap
7212 This prevents us continuously moving the single-step breakpoint
7213 forward, one instruction at a time, overstepping. */
7215 if (stop_pc
!= tp
->prev_pc
)
7220 fprintf_unfiltered (gdb_stdlog
,
7221 "infrun: expected thread advanced also (%s -> %s)\n",
7222 paddress (target_gdbarch (), tp
->prev_pc
),
7223 paddress (target_gdbarch (), stop_pc
));
7225 /* Clear the info of the previous step-over, as it's no longer
7226 valid (if the thread was trying to step over a breakpoint, it
7227 has already succeeded). It's what keep_going would do too,
7228 if we called it. Do this before trying to insert the sss
7229 breakpoint, otherwise if we were previously trying to step
7230 over this exact address in another thread, the breakpoint is
7232 clear_step_over_info ();
7233 tp
->control
.trap_expected
= 0;
7235 insert_single_step_breakpoint (get_frame_arch (frame
),
7236 get_frame_address_space (frame
),
7240 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7241 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7246 fprintf_unfiltered (gdb_stdlog
,
7247 "infrun: expected thread still hasn't advanced\n");
7249 keep_going_pass_signal (ecs
);
7254 /* Is thread TP in the middle of (software or hardware)
7255 single-stepping? (Note the result of this function must never be
7256 passed directly as target_resume's STEP parameter.) */
7259 currently_stepping (struct thread_info
*tp
)
7261 return ((tp
->control
.step_range_end
7262 && tp
->control
.step_resume_breakpoint
== NULL
)
7263 || tp
->control
.trap_expected
7264 || tp
->stepped_breakpoint
7265 || bpstat_should_step ());
7268 /* Inferior has stepped into a subroutine call with source code that
7269 we should not step over. Do step to the first line of code in
7273 handle_step_into_function (struct gdbarch
*gdbarch
,
7274 struct execution_control_state
*ecs
)
7276 struct compunit_symtab
*cust
;
7277 struct symtab_and_line stop_func_sal
, sr_sal
;
7279 fill_in_stop_func (gdbarch
, ecs
);
7281 cust
= find_pc_compunit_symtab (stop_pc
);
7282 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7283 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
7284 ecs
->stop_func_start
);
7286 stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7287 /* Use the step_resume_break to step until the end of the prologue,
7288 even if that involves jumps (as it seems to on the vax under
7290 /* If the prologue ends in the middle of a source line, continue to
7291 the end of that source line (if it is still within the function).
7292 Otherwise, just go to end of prologue. */
7293 if (stop_func_sal
.end
7294 && stop_func_sal
.pc
!= ecs
->stop_func_start
7295 && stop_func_sal
.end
< ecs
->stop_func_end
)
7296 ecs
->stop_func_start
= stop_func_sal
.end
;
7298 /* Architectures which require breakpoint adjustment might not be able
7299 to place a breakpoint at the computed address. If so, the test
7300 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7301 ecs->stop_func_start to an address at which a breakpoint may be
7302 legitimately placed.
7304 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7305 made, GDB will enter an infinite loop when stepping through
7306 optimized code consisting of VLIW instructions which contain
7307 subinstructions corresponding to different source lines. On
7308 FR-V, it's not permitted to place a breakpoint on any but the
7309 first subinstruction of a VLIW instruction. When a breakpoint is
7310 set, GDB will adjust the breakpoint address to the beginning of
7311 the VLIW instruction. Thus, we need to make the corresponding
7312 adjustment here when computing the stop address. */
7314 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7316 ecs
->stop_func_start
7317 = gdbarch_adjust_breakpoint_address (gdbarch
,
7318 ecs
->stop_func_start
);
7321 if (ecs
->stop_func_start
== stop_pc
)
7323 /* We are already there: stop now. */
7324 end_stepping_range (ecs
);
7329 /* Put the step-breakpoint there and go until there. */
7330 init_sal (&sr_sal
); /* initialize to zeroes */
7331 sr_sal
.pc
= ecs
->stop_func_start
;
7332 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7333 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7335 /* Do not specify what the fp should be when we stop since on
7336 some machines the prologue is where the new fp value is
7338 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7340 /* And make sure stepping stops right away then. */
7341 ecs
->event_thread
->control
.step_range_end
7342 = ecs
->event_thread
->control
.step_range_start
;
7347 /* Inferior has stepped backward into a subroutine call with source
7348 code that we should not step over. Do step to the beginning of the
7349 last line of code in it. */
7352 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7353 struct execution_control_state
*ecs
)
7355 struct compunit_symtab
*cust
;
7356 struct symtab_and_line stop_func_sal
;
7358 fill_in_stop_func (gdbarch
, ecs
);
7360 cust
= find_pc_compunit_symtab (stop_pc
);
7361 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7362 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
7363 ecs
->stop_func_start
);
7365 stop_func_sal
= find_pc_line (stop_pc
, 0);
7367 /* OK, we're just going to keep stepping here. */
7368 if (stop_func_sal
.pc
== stop_pc
)
7370 /* We're there already. Just stop stepping now. */
7371 end_stepping_range (ecs
);
7375 /* Else just reset the step range and keep going.
7376 No step-resume breakpoint, they don't work for
7377 epilogues, which can have multiple entry paths. */
7378 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7379 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7385 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7386 This is used to both functions and to skip over code. */
7389 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7390 struct symtab_and_line sr_sal
,
7391 struct frame_id sr_id
,
7392 enum bptype sr_type
)
7394 /* There should never be more than one step-resume or longjmp-resume
7395 breakpoint per thread, so we should never be setting a new
7396 step_resume_breakpoint when one is already active. */
7397 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7398 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7401 fprintf_unfiltered (gdb_stdlog
,
7402 "infrun: inserting step-resume breakpoint at %s\n",
7403 paddress (gdbarch
, sr_sal
.pc
));
7405 inferior_thread ()->control
.step_resume_breakpoint
7406 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
);
7410 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7411 struct symtab_and_line sr_sal
,
7412 struct frame_id sr_id
)
7414 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7419 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7420 This is used to skip a potential signal handler.
7422 This is called with the interrupted function's frame. The signal
7423 handler, when it returns, will resume the interrupted function at
7427 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7429 struct symtab_and_line sr_sal
;
7430 struct gdbarch
*gdbarch
;
7432 gdb_assert (return_frame
!= NULL
);
7433 init_sal (&sr_sal
); /* initialize to zeros */
7435 gdbarch
= get_frame_arch (return_frame
);
7436 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7437 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7438 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7440 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7441 get_stack_frame_id (return_frame
),
7445 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7446 is used to skip a function after stepping into it (for "next" or if
7447 the called function has no debugging information).
7449 The current function has almost always been reached by single
7450 stepping a call or return instruction. NEXT_FRAME belongs to the
7451 current function, and the breakpoint will be set at the caller's
7454 This is a separate function rather than reusing
7455 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7456 get_prev_frame, which may stop prematurely (see the implementation
7457 of frame_unwind_caller_id for an example). */
7460 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7462 struct symtab_and_line sr_sal
;
7463 struct gdbarch
*gdbarch
;
7465 /* We shouldn't have gotten here if we don't know where the call site
7467 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7469 init_sal (&sr_sal
); /* initialize to zeros */
7471 gdbarch
= frame_unwind_caller_arch (next_frame
);
7472 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7473 frame_unwind_caller_pc (next_frame
));
7474 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7475 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7477 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7478 frame_unwind_caller_id (next_frame
));
7481 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7482 new breakpoint at the target of a jmp_buf. The handling of
7483 longjmp-resume uses the same mechanisms used for handling
7484 "step-resume" breakpoints. */
7487 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7489 /* There should never be more than one longjmp-resume breakpoint per
7490 thread, so we should never be setting a new
7491 longjmp_resume_breakpoint when one is already active. */
7492 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7495 fprintf_unfiltered (gdb_stdlog
,
7496 "infrun: inserting longjmp-resume breakpoint at %s\n",
7497 paddress (gdbarch
, pc
));
7499 inferior_thread ()->control
.exception_resume_breakpoint
=
7500 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
);
7503 /* Insert an exception resume breakpoint. TP is the thread throwing
7504 the exception. The block B is the block of the unwinder debug hook
7505 function. FRAME is the frame corresponding to the call to this
7506 function. SYM is the symbol of the function argument holding the
7507 target PC of the exception. */
7510 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7511 const struct block
*b
,
7512 struct frame_info
*frame
,
7517 struct block_symbol vsym
;
7518 struct value
*value
;
7520 struct breakpoint
*bp
;
7522 vsym
= lookup_symbol (SYMBOL_LINKAGE_NAME (sym
), b
, VAR_DOMAIN
, NULL
);
7523 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7524 /* If the value was optimized out, revert to the old behavior. */
7525 if (! value_optimized_out (value
))
7527 handler
= value_as_address (value
);
7530 fprintf_unfiltered (gdb_stdlog
,
7531 "infrun: exception resume at %lx\n",
7532 (unsigned long) handler
);
7534 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7535 handler
, bp_exception_resume
);
7537 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7540 bp
->thread
= tp
->global_num
;
7541 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7544 CATCH (e
, RETURN_MASK_ERROR
)
7546 /* We want to ignore errors here. */
7551 /* A helper for check_exception_resume that sets an
7552 exception-breakpoint based on a SystemTap probe. */
7555 insert_exception_resume_from_probe (struct thread_info
*tp
,
7556 const struct bound_probe
*probe
,
7557 struct frame_info
*frame
)
7559 struct value
*arg_value
;
7561 struct breakpoint
*bp
;
7563 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7567 handler
= value_as_address (arg_value
);
7570 fprintf_unfiltered (gdb_stdlog
,
7571 "infrun: exception resume at %s\n",
7572 paddress (get_objfile_arch (probe
->objfile
),
7575 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7576 handler
, bp_exception_resume
);
7577 bp
->thread
= tp
->global_num
;
7578 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7581 /* This is called when an exception has been intercepted. Check to
7582 see whether the exception's destination is of interest, and if so,
7583 set an exception resume breakpoint there. */
7586 check_exception_resume (struct execution_control_state
*ecs
,
7587 struct frame_info
*frame
)
7589 struct bound_probe probe
;
7590 struct symbol
*func
;
7592 /* First see if this exception unwinding breakpoint was set via a
7593 SystemTap probe point. If so, the probe has two arguments: the
7594 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7595 set a breakpoint there. */
7596 probe
= find_probe_by_pc (get_frame_pc (frame
));
7599 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7603 func
= get_frame_function (frame
);
7609 const struct block
*b
;
7610 struct block_iterator iter
;
7614 /* The exception breakpoint is a thread-specific breakpoint on
7615 the unwinder's debug hook, declared as:
7617 void _Unwind_DebugHook (void *cfa, void *handler);
7619 The CFA argument indicates the frame to which control is
7620 about to be transferred. HANDLER is the destination PC.
7622 We ignore the CFA and set a temporary breakpoint at HANDLER.
7623 This is not extremely efficient but it avoids issues in gdb
7624 with computing the DWARF CFA, and it also works even in weird
7625 cases such as throwing an exception from inside a signal
7628 b
= SYMBOL_BLOCK_VALUE (func
);
7629 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7631 if (!SYMBOL_IS_ARGUMENT (sym
))
7638 insert_exception_resume_breakpoint (ecs
->event_thread
,
7644 CATCH (e
, RETURN_MASK_ERROR
)
7651 stop_waiting (struct execution_control_state
*ecs
)
7654 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7656 clear_step_over_info ();
7658 /* Let callers know we don't want to wait for the inferior anymore. */
7659 ecs
->wait_some_more
= 0;
7661 /* If all-stop, but the target is always in non-stop mode, stop all
7662 threads now that we're presenting the stop to the user. */
7663 if (!non_stop
&& target_is_non_stop_p ())
7664 stop_all_threads ();
7667 /* Like keep_going, but passes the signal to the inferior, even if the
7668 signal is set to nopass. */
7671 keep_going_pass_signal (struct execution_control_state
*ecs
)
7673 /* Make sure normal_stop is called if we get a QUIT handled before
7675 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
7677 gdb_assert (ptid_equal (ecs
->event_thread
->ptid
, inferior_ptid
));
7678 gdb_assert (!ecs
->event_thread
->resumed
);
7680 /* Save the pc before execution, to compare with pc after stop. */
7681 ecs
->event_thread
->prev_pc
7682 = regcache_read_pc (get_thread_regcache (ecs
->ptid
));
7684 if (ecs
->event_thread
->control
.trap_expected
)
7686 struct thread_info
*tp
= ecs
->event_thread
;
7689 fprintf_unfiltered (gdb_stdlog
,
7690 "infrun: %s has trap_expected set, "
7691 "resuming to collect trap\n",
7692 target_pid_to_str (tp
->ptid
));
7694 /* We haven't yet gotten our trap, and either: intercepted a
7695 non-signal event (e.g., a fork); or took a signal which we
7696 are supposed to pass through to the inferior. Simply
7698 discard_cleanups (old_cleanups
);
7699 resume (ecs
->event_thread
->suspend
.stop_signal
);
7701 else if (step_over_info_valid_p ())
7703 /* Another thread is stepping over a breakpoint in-line. If
7704 this thread needs a step-over too, queue the request. In
7705 either case, this resume must be deferred for later. */
7706 struct thread_info
*tp
= ecs
->event_thread
;
7708 if (ecs
->hit_singlestep_breakpoint
7709 || thread_still_needs_step_over (tp
))
7712 fprintf_unfiltered (gdb_stdlog
,
7713 "infrun: step-over already in progress: "
7714 "step-over for %s deferred\n",
7715 target_pid_to_str (tp
->ptid
));
7716 thread_step_over_chain_enqueue (tp
);
7721 fprintf_unfiltered (gdb_stdlog
,
7722 "infrun: step-over in progress: "
7723 "resume of %s deferred\n",
7724 target_pid_to_str (tp
->ptid
));
7727 discard_cleanups (old_cleanups
);
7731 struct regcache
*regcache
= get_current_regcache ();
7734 step_over_what step_what
;
7736 /* Either the trap was not expected, but we are continuing
7737 anyway (if we got a signal, the user asked it be passed to
7740 We got our expected trap, but decided we should resume from
7743 We're going to run this baby now!
7745 Note that insert_breakpoints won't try to re-insert
7746 already inserted breakpoints. Therefore, we don't
7747 care if breakpoints were already inserted, or not. */
7749 /* If we need to step over a breakpoint, and we're not using
7750 displaced stepping to do so, insert all breakpoints
7751 (watchpoints, etc.) but the one we're stepping over, step one
7752 instruction, and then re-insert the breakpoint when that step
7755 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7757 remove_bp
= (ecs
->hit_singlestep_breakpoint
7758 || (step_what
& STEP_OVER_BREAKPOINT
));
7759 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7761 /* We can't use displaced stepping if we need to step past a
7762 watchpoint. The instruction copied to the scratch pad would
7763 still trigger the watchpoint. */
7765 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7767 set_step_over_info (get_regcache_aspace (regcache
),
7768 regcache_read_pc (regcache
), remove_wps
,
7769 ecs
->event_thread
->global_num
);
7771 else if (remove_wps
)
7772 set_step_over_info (NULL
, 0, remove_wps
, -1);
7774 /* If we now need to do an in-line step-over, we need to stop
7775 all other threads. Note this must be done before
7776 insert_breakpoints below, because that removes the breakpoint
7777 we're about to step over, otherwise other threads could miss
7779 if (step_over_info_valid_p () && target_is_non_stop_p ())
7780 stop_all_threads ();
7782 /* Stop stepping if inserting breakpoints fails. */
7785 insert_breakpoints ();
7787 CATCH (e
, RETURN_MASK_ERROR
)
7789 exception_print (gdb_stderr
, e
);
7791 discard_cleanups (old_cleanups
);
7796 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7798 discard_cleanups (old_cleanups
);
7799 resume (ecs
->event_thread
->suspend
.stop_signal
);
7802 prepare_to_wait (ecs
);
7805 /* Called when we should continue running the inferior, because the
7806 current event doesn't cause a user visible stop. This does the
7807 resuming part; waiting for the next event is done elsewhere. */
7810 keep_going (struct execution_control_state
*ecs
)
7812 if (ecs
->event_thread
->control
.trap_expected
7813 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7814 ecs
->event_thread
->control
.trap_expected
= 0;
7816 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7817 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7818 keep_going_pass_signal (ecs
);
7821 /* This function normally comes after a resume, before
7822 handle_inferior_event exits. It takes care of any last bits of
7823 housekeeping, and sets the all-important wait_some_more flag. */
7826 prepare_to_wait (struct execution_control_state
*ecs
)
7829 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7831 ecs
->wait_some_more
= 1;
7833 if (!target_is_async_p ())
7834 mark_infrun_async_event_handler ();
7837 /* We are done with the step range of a step/next/si/ni command.
7838 Called once for each n of a "step n" operation. */
7841 end_stepping_range (struct execution_control_state
*ecs
)
7843 ecs
->event_thread
->control
.stop_step
= 1;
7847 /* Several print_*_reason functions to print why the inferior has stopped.
7848 We always print something when the inferior exits, or receives a signal.
7849 The rest of the cases are dealt with later on in normal_stop and
7850 print_it_typical. Ideally there should be a call to one of these
7851 print_*_reason functions functions from handle_inferior_event each time
7852 stop_waiting is called.
7854 Note that we don't call these directly, instead we delegate that to
7855 the interpreters, through observers. Interpreters then call these
7856 with whatever uiout is right. */
7859 print_end_stepping_range_reason (struct ui_out
*uiout
)
7861 /* For CLI-like interpreters, print nothing. */
7863 if (ui_out_is_mi_like_p (uiout
))
7865 ui_out_field_string (uiout
, "reason",
7866 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7871 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7873 annotate_signalled ();
7874 if (ui_out_is_mi_like_p (uiout
))
7876 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7877 ui_out_text (uiout
, "\nProgram terminated with signal ");
7878 annotate_signal_name ();
7879 ui_out_field_string (uiout
, "signal-name",
7880 gdb_signal_to_name (siggnal
));
7881 annotate_signal_name_end ();
7882 ui_out_text (uiout
, ", ");
7883 annotate_signal_string ();
7884 ui_out_field_string (uiout
, "signal-meaning",
7885 gdb_signal_to_string (siggnal
));
7886 annotate_signal_string_end ();
7887 ui_out_text (uiout
, ".\n");
7888 ui_out_text (uiout
, "The program no longer exists.\n");
7892 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7894 struct inferior
*inf
= current_inferior ();
7895 const char *pidstr
= target_pid_to_str (pid_to_ptid (inf
->pid
));
7897 annotate_exited (exitstatus
);
7900 if (ui_out_is_mi_like_p (uiout
))
7901 ui_out_field_string (uiout
, "reason",
7902 async_reason_lookup (EXEC_ASYNC_EXITED
));
7903 ui_out_text (uiout
, "[Inferior ");
7904 ui_out_text (uiout
, plongest (inf
->num
));
7905 ui_out_text (uiout
, " (");
7906 ui_out_text (uiout
, pidstr
);
7907 ui_out_text (uiout
, ") exited with code ");
7908 ui_out_field_fmt (uiout
, "exit-code", "0%o", (unsigned int) exitstatus
);
7909 ui_out_text (uiout
, "]\n");
7913 if (ui_out_is_mi_like_p (uiout
))
7915 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7916 ui_out_text (uiout
, "[Inferior ");
7917 ui_out_text (uiout
, plongest (inf
->num
));
7918 ui_out_text (uiout
, " (");
7919 ui_out_text (uiout
, pidstr
);
7920 ui_out_text (uiout
, ") exited normally]\n");
7924 /* Some targets/architectures can do extra processing/display of
7925 segmentation faults. E.g., Intel MPX boundary faults.
7926 Call the architecture dependent function to handle the fault. */
7929 handle_segmentation_fault (struct ui_out
*uiout
)
7931 struct regcache
*regcache
= get_current_regcache ();
7932 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
7934 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7935 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7939 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7941 struct thread_info
*thr
= inferior_thread ();
7945 if (ui_out_is_mi_like_p (uiout
))
7947 else if (show_thread_that_caused_stop ())
7951 ui_out_text (uiout
, "\nThread ");
7952 ui_out_field_fmt (uiout
, "thread-id", "%s", print_thread_id (thr
));
7954 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7957 ui_out_text (uiout
, " \"");
7958 ui_out_field_fmt (uiout
, "name", "%s", name
);
7959 ui_out_text (uiout
, "\"");
7963 ui_out_text (uiout
, "\nProgram");
7965 if (siggnal
== GDB_SIGNAL_0
&& !ui_out_is_mi_like_p (uiout
))
7966 ui_out_text (uiout
, " stopped");
7969 ui_out_text (uiout
, " received signal ");
7970 annotate_signal_name ();
7971 if (ui_out_is_mi_like_p (uiout
))
7973 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7974 ui_out_field_string (uiout
, "signal-name",
7975 gdb_signal_to_name (siggnal
));
7976 annotate_signal_name_end ();
7977 ui_out_text (uiout
, ", ");
7978 annotate_signal_string ();
7979 ui_out_field_string (uiout
, "signal-meaning",
7980 gdb_signal_to_string (siggnal
));
7982 if (siggnal
== GDB_SIGNAL_SEGV
)
7983 handle_segmentation_fault (uiout
);
7985 annotate_signal_string_end ();
7987 ui_out_text (uiout
, ".\n");
7991 print_no_history_reason (struct ui_out
*uiout
)
7993 ui_out_text (uiout
, "\nNo more reverse-execution history.\n");
7996 /* Print current location without a level number, if we have changed
7997 functions or hit a breakpoint. Print source line if we have one.
7998 bpstat_print contains the logic deciding in detail what to print,
7999 based on the event(s) that just occurred. */
8002 print_stop_location (struct target_waitstatus
*ws
)
8005 enum print_what source_flag
;
8006 int do_frame_printing
= 1;
8007 struct thread_info
*tp
= inferior_thread ();
8009 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8013 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8014 should) carry around the function and does (or should) use
8015 that when doing a frame comparison. */
8016 if (tp
->control
.stop_step
8017 && frame_id_eq (tp
->control
.step_frame_id
,
8018 get_frame_id (get_current_frame ()))
8019 && tp
->control
.step_start_function
== find_pc_function (stop_pc
))
8021 /* Finished step, just print source line. */
8022 source_flag
= SRC_LINE
;
8026 /* Print location and source line. */
8027 source_flag
= SRC_AND_LOC
;
8030 case PRINT_SRC_AND_LOC
:
8031 /* Print location and source line. */
8032 source_flag
= SRC_AND_LOC
;
8034 case PRINT_SRC_ONLY
:
8035 source_flag
= SRC_LINE
;
8038 /* Something bogus. */
8039 source_flag
= SRC_LINE
;
8040 do_frame_printing
= 0;
8043 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8046 /* The behavior of this routine with respect to the source
8048 SRC_LINE: Print only source line
8049 LOCATION: Print only location
8050 SRC_AND_LOC: Print location and source line. */
8051 if (do_frame_printing
)
8052 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8055 /* Cleanup that restores a previous current uiout. */
8058 restore_current_uiout_cleanup (void *arg
)
8060 struct ui_out
*saved_uiout
= (struct ui_out
*) arg
;
8062 current_uiout
= saved_uiout
;
8068 print_stop_event (struct ui_out
*uiout
)
8070 struct cleanup
*old_chain
;
8071 struct target_waitstatus last
;
8073 struct thread_info
*tp
;
8075 get_last_target_status (&last_ptid
, &last
);
8077 old_chain
= make_cleanup (restore_current_uiout_cleanup
, current_uiout
);
8078 current_uiout
= uiout
;
8080 print_stop_location (&last
);
8082 /* Display the auto-display expressions. */
8085 do_cleanups (old_chain
);
8087 tp
= inferior_thread ();
8088 if (tp
->thread_fsm
!= NULL
8089 && thread_fsm_finished_p (tp
->thread_fsm
))
8091 struct return_value_info
*rv
;
8093 rv
= thread_fsm_return_value (tp
->thread_fsm
);
8095 print_return_value (uiout
, rv
);
8102 maybe_remove_breakpoints (void)
8104 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8106 if (remove_breakpoints ())
8108 target_terminal_ours_for_output ();
8109 printf_filtered (_("Cannot remove breakpoints because "
8110 "program is no longer writable.\nFurther "
8111 "execution is probably impossible.\n"));
8116 /* The execution context that just caused a normal stop. */
8123 /* The event PTID. */
8127 /* If stopp for a thread event, this is the thread that caused the
8129 struct thread_info
*thread
;
8131 /* The inferior that caused the stop. */
8135 /* Returns a new stop context. If stopped for a thread event, this
8136 takes a strong reference to the thread. */
8138 static struct stop_context
*
8139 save_stop_context (void)
8141 struct stop_context
*sc
= XNEW (struct stop_context
);
8143 sc
->stop_id
= get_stop_id ();
8144 sc
->ptid
= inferior_ptid
;
8145 sc
->inf_num
= current_inferior ()->num
;
8147 if (!ptid_equal (inferior_ptid
, null_ptid
))
8149 /* Take a strong reference so that the thread can't be deleted
8151 sc
->thread
= inferior_thread ();
8152 sc
->thread
->refcount
++;
8160 /* Release a stop context previously created with save_stop_context.
8161 Releases the strong reference to the thread as well. */
8164 release_stop_context_cleanup (void *arg
)
8166 struct stop_context
*sc
= (struct stop_context
*) arg
;
8168 if (sc
->thread
!= NULL
)
8169 sc
->thread
->refcount
--;
8173 /* Return true if the current context no longer matches the saved stop
8177 stop_context_changed (struct stop_context
*prev
)
8179 if (!ptid_equal (prev
->ptid
, inferior_ptid
))
8181 if (prev
->inf_num
!= current_inferior ()->num
)
8183 if (prev
->thread
!= NULL
&& prev
->thread
->state
!= THREAD_STOPPED
)
8185 if (get_stop_id () != prev
->stop_id
)
8195 struct target_waitstatus last
;
8197 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
8200 get_last_target_status (&last_ptid
, &last
);
8204 /* If an exception is thrown from this point on, make sure to
8205 propagate GDB's knowledge of the executing state to the
8206 frontend/user running state. A QUIT is an easy exception to see
8207 here, so do this before any filtered output. */
8209 make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
8210 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8211 || last
.kind
== TARGET_WAITKIND_EXITED
)
8213 /* On some targets, we may still have live threads in the
8214 inferior when we get a process exit event. E.g., for
8215 "checkpoint", when the current checkpoint/fork exits,
8216 linux-fork.c automatically switches to another fork from
8217 within target_mourn_inferior. */
8218 if (!ptid_equal (inferior_ptid
, null_ptid
))
8220 pid_ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
8221 make_cleanup (finish_thread_state_cleanup
, &pid_ptid
);
8224 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8225 make_cleanup (finish_thread_state_cleanup
, &inferior_ptid
);
8227 /* As we're presenting a stop, and potentially removing breakpoints,
8228 update the thread list so we can tell whether there are threads
8229 running on the target. With target remote, for example, we can
8230 only learn about new threads when we explicitly update the thread
8231 list. Do this before notifying the interpreters about signal
8232 stops, end of stepping ranges, etc., so that the "new thread"
8233 output is emitted before e.g., "Program received signal FOO",
8234 instead of after. */
8235 update_thread_list ();
8237 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8238 observer_notify_signal_received (inferior_thread ()->suspend
.stop_signal
);
8240 /* As with the notification of thread events, we want to delay
8241 notifying the user that we've switched thread context until
8242 the inferior actually stops.
8244 There's no point in saying anything if the inferior has exited.
8245 Note that SIGNALLED here means "exited with a signal", not
8246 "received a signal".
8248 Also skip saying anything in non-stop mode. In that mode, as we
8249 don't want GDB to switch threads behind the user's back, to avoid
8250 races where the user is typing a command to apply to thread x,
8251 but GDB switches to thread y before the user finishes entering
8252 the command, fetch_inferior_event installs a cleanup to restore
8253 the current thread back to the thread the user had selected right
8254 after this event is handled, so we're not really switching, only
8255 informing of a stop. */
8257 && !ptid_equal (previous_inferior_ptid
, inferior_ptid
)
8258 && target_has_execution
8259 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8260 && last
.kind
!= TARGET_WAITKIND_EXITED
8261 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8263 target_terminal_ours_for_output ();
8264 printf_filtered (_("[Switching to %s]\n"),
8265 target_pid_to_str (inferior_ptid
));
8266 annotate_thread_changed ();
8267 previous_inferior_ptid
= inferior_ptid
;
8270 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8272 gdb_assert (sync_execution
|| !target_can_async_p ());
8274 target_terminal_ours_for_output ();
8275 printf_filtered (_("No unwaited-for children left.\n"));
8278 /* Note: this depends on the update_thread_list call above. */
8279 maybe_remove_breakpoints ();
8281 /* If an auto-display called a function and that got a signal,
8282 delete that auto-display to avoid an infinite recursion. */
8284 if (stopped_by_random_signal
)
8285 disable_current_display ();
8287 target_terminal_ours ();
8288 async_enable_stdin ();
8290 /* Let the user/frontend see the threads as stopped. */
8291 do_cleanups (old_chain
);
8293 /* Select innermost stack frame - i.e., current frame is frame 0,
8294 and current location is based on that. Handle the case where the
8295 dummy call is returning after being stopped. E.g. the dummy call
8296 previously hit a breakpoint. (If the dummy call returns
8297 normally, we won't reach here.) Do this before the stop hook is
8298 run, so that it doesn't get to see the temporary dummy frame,
8299 which is not where we'll present the stop. */
8300 if (has_stack_frames ())
8302 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8304 /* Pop the empty frame that contains the stack dummy. This
8305 also restores inferior state prior to the call (struct
8306 infcall_suspend_state). */
8307 struct frame_info
*frame
= get_current_frame ();
8309 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8311 /* frame_pop calls reinit_frame_cache as the last thing it
8312 does which means there's now no selected frame. */
8315 select_frame (get_current_frame ());
8317 /* Set the current source location. */
8318 set_current_sal_from_frame (get_current_frame ());
8321 /* Look up the hook_stop and run it (CLI internally handles problem
8322 of stop_command's pre-hook not existing). */
8323 if (stop_command
!= NULL
)
8325 struct stop_context
*saved_context
= save_stop_context ();
8326 struct cleanup
*old_chain
8327 = make_cleanup (release_stop_context_cleanup
, saved_context
);
8329 catch_errors (hook_stop_stub
, stop_command
,
8330 "Error while running hook_stop:\n", RETURN_MASK_ALL
);
8332 /* If the stop hook resumes the target, then there's no point in
8333 trying to notify about the previous stop; its context is
8334 gone. Likewise if the command switches thread or inferior --
8335 the observers would print a stop for the wrong
8337 if (stop_context_changed (saved_context
))
8339 do_cleanups (old_chain
);
8342 do_cleanups (old_chain
);
8345 /* Notify observers about the stop. This is where the interpreters
8346 print the stop event. */
8347 if (!ptid_equal (inferior_ptid
, null_ptid
))
8348 observer_notify_normal_stop (inferior_thread ()->control
.stop_bpstat
,
8351 observer_notify_normal_stop (NULL
, stop_print_frame
);
8353 annotate_stopped ();
8355 if (target_has_execution
)
8357 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8358 && last
.kind
!= TARGET_WAITKIND_EXITED
)
8359 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8360 Delete any breakpoint that is to be deleted at the next stop. */
8361 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8364 /* Try to get rid of automatically added inferiors that are no
8365 longer needed. Keeping those around slows down things linearly.
8366 Note that this never removes the current inferior. */
8373 hook_stop_stub (void *cmd
)
8375 execute_cmd_pre_hook ((struct cmd_list_element
*) cmd
);
8380 signal_stop_state (int signo
)
8382 return signal_stop
[signo
];
8386 signal_print_state (int signo
)
8388 return signal_print
[signo
];
8392 signal_pass_state (int signo
)
8394 return signal_program
[signo
];
8398 signal_cache_update (int signo
)
8402 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8403 signal_cache_update (signo
);
8408 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8409 && signal_print
[signo
] == 0
8410 && signal_program
[signo
] == 1
8411 && signal_catch
[signo
] == 0);
8415 signal_stop_update (int signo
, int state
)
8417 int ret
= signal_stop
[signo
];
8419 signal_stop
[signo
] = state
;
8420 signal_cache_update (signo
);
8425 signal_print_update (int signo
, int state
)
8427 int ret
= signal_print
[signo
];
8429 signal_print
[signo
] = state
;
8430 signal_cache_update (signo
);
8435 signal_pass_update (int signo
, int state
)
8437 int ret
= signal_program
[signo
];
8439 signal_program
[signo
] = state
;
8440 signal_cache_update (signo
);
8444 /* Update the global 'signal_catch' from INFO and notify the
8448 signal_catch_update (const unsigned int *info
)
8452 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8453 signal_catch
[i
] = info
[i
] > 0;
8454 signal_cache_update (-1);
8455 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
8459 sig_print_header (void)
8461 printf_filtered (_("Signal Stop\tPrint\tPass "
8462 "to program\tDescription\n"));
8466 sig_print_info (enum gdb_signal oursig
)
8468 const char *name
= gdb_signal_to_name (oursig
);
8469 int name_padding
= 13 - strlen (name
);
8471 if (name_padding
<= 0)
8474 printf_filtered ("%s", name
);
8475 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8476 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8477 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8478 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8479 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8482 /* Specify how various signals in the inferior should be handled. */
8485 handle_command (char *args
, int from_tty
)
8488 int digits
, wordlen
;
8489 int sigfirst
, signum
, siglast
;
8490 enum gdb_signal oursig
;
8493 unsigned char *sigs
;
8494 struct cleanup
*old_chain
;
8498 error_no_arg (_("signal to handle"));
8501 /* Allocate and zero an array of flags for which signals to handle. */
8503 nsigs
= (int) GDB_SIGNAL_LAST
;
8504 sigs
= (unsigned char *) alloca (nsigs
);
8505 memset (sigs
, 0, nsigs
);
8507 /* Break the command line up into args. */
8509 argv
= gdb_buildargv (args
);
8510 old_chain
= make_cleanup_freeargv (argv
);
8512 /* Walk through the args, looking for signal oursigs, signal names, and
8513 actions. Signal numbers and signal names may be interspersed with
8514 actions, with the actions being performed for all signals cumulatively
8515 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8517 while (*argv
!= NULL
)
8519 wordlen
= strlen (*argv
);
8520 for (digits
= 0; isdigit ((*argv
)[digits
]); digits
++)
8524 sigfirst
= siglast
= -1;
8526 if (wordlen
>= 1 && !strncmp (*argv
, "all", wordlen
))
8528 /* Apply action to all signals except those used by the
8529 debugger. Silently skip those. */
8532 siglast
= nsigs
- 1;
8534 else if (wordlen
>= 1 && !strncmp (*argv
, "stop", wordlen
))
8536 SET_SIGS (nsigs
, sigs
, signal_stop
);
8537 SET_SIGS (nsigs
, sigs
, signal_print
);
8539 else if (wordlen
>= 1 && !strncmp (*argv
, "ignore", wordlen
))
8541 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8543 else if (wordlen
>= 2 && !strncmp (*argv
, "print", wordlen
))
8545 SET_SIGS (nsigs
, sigs
, signal_print
);
8547 else if (wordlen
>= 2 && !strncmp (*argv
, "pass", wordlen
))
8549 SET_SIGS (nsigs
, sigs
, signal_program
);
8551 else if (wordlen
>= 3 && !strncmp (*argv
, "nostop", wordlen
))
8553 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8555 else if (wordlen
>= 3 && !strncmp (*argv
, "noignore", wordlen
))
8557 SET_SIGS (nsigs
, sigs
, signal_program
);
8559 else if (wordlen
>= 4 && !strncmp (*argv
, "noprint", wordlen
))
8561 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8562 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8564 else if (wordlen
>= 4 && !strncmp (*argv
, "nopass", wordlen
))
8566 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8568 else if (digits
> 0)
8570 /* It is numeric. The numeric signal refers to our own
8571 internal signal numbering from target.h, not to host/target
8572 signal number. This is a feature; users really should be
8573 using symbolic names anyway, and the common ones like
8574 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8576 sigfirst
= siglast
= (int)
8577 gdb_signal_from_command (atoi (*argv
));
8578 if ((*argv
)[digits
] == '-')
8581 gdb_signal_from_command (atoi ((*argv
) + digits
+ 1));
8583 if (sigfirst
> siglast
)
8585 /* Bet he didn't figure we'd think of this case... */
8593 oursig
= gdb_signal_from_name (*argv
);
8594 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8596 sigfirst
= siglast
= (int) oursig
;
8600 /* Not a number and not a recognized flag word => complain. */
8601 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv
);
8605 /* If any signal numbers or symbol names were found, set flags for
8606 which signals to apply actions to. */
8608 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8610 switch ((enum gdb_signal
) signum
)
8612 case GDB_SIGNAL_TRAP
:
8613 case GDB_SIGNAL_INT
:
8614 if (!allsigs
&& !sigs
[signum
])
8616 if (query (_("%s is used by the debugger.\n\
8617 Are you sure you want to change it? "),
8618 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8624 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8625 gdb_flush (gdb_stdout
);
8630 case GDB_SIGNAL_DEFAULT
:
8631 case GDB_SIGNAL_UNKNOWN
:
8632 /* Make sure that "all" doesn't print these. */
8643 for (signum
= 0; signum
< nsigs
; signum
++)
8646 signal_cache_update (-1);
8647 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
8648 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
8652 /* Show the results. */
8653 sig_print_header ();
8654 for (; signum
< nsigs
; signum
++)
8656 sig_print_info ((enum gdb_signal
) signum
);
8662 do_cleanups (old_chain
);
8665 /* Complete the "handle" command. */
8667 static VEC (char_ptr
) *
8668 handle_completer (struct cmd_list_element
*ignore
,
8669 const char *text
, const char *word
)
8671 VEC (char_ptr
) *vec_signals
, *vec_keywords
, *return_val
;
8672 static const char * const keywords
[] =
8686 vec_signals
= signal_completer (ignore
, text
, word
);
8687 vec_keywords
= complete_on_enum (keywords
, word
, word
);
8689 return_val
= VEC_merge (char_ptr
, vec_signals
, vec_keywords
);
8690 VEC_free (char_ptr
, vec_signals
);
8691 VEC_free (char_ptr
, vec_keywords
);
8696 gdb_signal_from_command (int num
)
8698 if (num
>= 1 && num
<= 15)
8699 return (enum gdb_signal
) num
;
8700 error (_("Only signals 1-15 are valid as numeric signals.\n\
8701 Use \"info signals\" for a list of symbolic signals."));
8704 /* Print current contents of the tables set by the handle command.
8705 It is possible we should just be printing signals actually used
8706 by the current target (but for things to work right when switching
8707 targets, all signals should be in the signal tables). */
8710 signals_info (char *signum_exp
, int from_tty
)
8712 enum gdb_signal oursig
;
8714 sig_print_header ();
8718 /* First see if this is a symbol name. */
8719 oursig
= gdb_signal_from_name (signum_exp
);
8720 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8722 /* No, try numeric. */
8724 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8726 sig_print_info (oursig
);
8730 printf_filtered ("\n");
8731 /* These ugly casts brought to you by the native VAX compiler. */
8732 for (oursig
= GDB_SIGNAL_FIRST
;
8733 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8734 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8738 if (oursig
!= GDB_SIGNAL_UNKNOWN
8739 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8740 sig_print_info (oursig
);
8743 printf_filtered (_("\nUse the \"handle\" command "
8744 "to change these tables.\n"));
8747 /* The $_siginfo convenience variable is a bit special. We don't know
8748 for sure the type of the value until we actually have a chance to
8749 fetch the data. The type can change depending on gdbarch, so it is
8750 also dependent on which thread you have selected.
8752 1. making $_siginfo be an internalvar that creates a new value on
8755 2. making the value of $_siginfo be an lval_computed value. */
8757 /* This function implements the lval_computed support for reading a
8761 siginfo_value_read (struct value
*v
)
8763 LONGEST transferred
;
8765 /* If we can access registers, so can we access $_siginfo. Likewise
8767 validate_registers_access ();
8770 target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
,
8772 value_contents_all_raw (v
),
8774 TYPE_LENGTH (value_type (v
)));
8776 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8777 error (_("Unable to read siginfo"));
8780 /* This function implements the lval_computed support for writing a
8784 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8786 LONGEST transferred
;
8788 /* If we can access registers, so can we access $_siginfo. Likewise
8790 validate_registers_access ();
8792 transferred
= target_write (¤t_target
,
8793 TARGET_OBJECT_SIGNAL_INFO
,
8795 value_contents_all_raw (fromval
),
8797 TYPE_LENGTH (value_type (fromval
)));
8799 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8800 error (_("Unable to write siginfo"));
8803 static const struct lval_funcs siginfo_value_funcs
=
8809 /* Return a new value with the correct type for the siginfo object of
8810 the current thread using architecture GDBARCH. Return a void value
8811 if there's no object available. */
8813 static struct value
*
8814 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8817 if (target_has_stack
8818 && !ptid_equal (inferior_ptid
, null_ptid
)
8819 && gdbarch_get_siginfo_type_p (gdbarch
))
8821 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8823 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8826 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8830 /* infcall_suspend_state contains state about the program itself like its
8831 registers and any signal it received when it last stopped.
8832 This state must be restored regardless of how the inferior function call
8833 ends (either successfully, or after it hits a breakpoint or signal)
8834 if the program is to properly continue where it left off. */
8836 struct infcall_suspend_state
8838 struct thread_suspend_state thread_suspend
;
8842 struct regcache
*registers
;
8844 /* Format of SIGINFO_DATA or NULL if it is not present. */
8845 struct gdbarch
*siginfo_gdbarch
;
8847 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8848 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8849 content would be invalid. */
8850 gdb_byte
*siginfo_data
;
8853 struct infcall_suspend_state
*
8854 save_infcall_suspend_state (void)
8856 struct infcall_suspend_state
*inf_state
;
8857 struct thread_info
*tp
= inferior_thread ();
8858 struct regcache
*regcache
= get_current_regcache ();
8859 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
8860 gdb_byte
*siginfo_data
= NULL
;
8862 if (gdbarch_get_siginfo_type_p (gdbarch
))
8864 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8865 size_t len
= TYPE_LENGTH (type
);
8866 struct cleanup
*back_to
;
8868 siginfo_data
= (gdb_byte
*) xmalloc (len
);
8869 back_to
= make_cleanup (xfree
, siginfo_data
);
8871 if (target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8872 siginfo_data
, 0, len
) == len
)
8873 discard_cleanups (back_to
);
8876 /* Errors ignored. */
8877 do_cleanups (back_to
);
8878 siginfo_data
= NULL
;
8882 inf_state
= XCNEW (struct infcall_suspend_state
);
8886 inf_state
->siginfo_gdbarch
= gdbarch
;
8887 inf_state
->siginfo_data
= siginfo_data
;
8890 inf_state
->thread_suspend
= tp
->suspend
;
8892 /* run_inferior_call will not use the signal due to its `proceed' call with
8893 GDB_SIGNAL_0 anyway. */
8894 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8896 inf_state
->stop_pc
= stop_pc
;
8898 inf_state
->registers
= regcache_dup (regcache
);
8903 /* Restore inferior session state to INF_STATE. */
8906 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8908 struct thread_info
*tp
= inferior_thread ();
8909 struct regcache
*regcache
= get_current_regcache ();
8910 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
8912 tp
->suspend
= inf_state
->thread_suspend
;
8914 stop_pc
= inf_state
->stop_pc
;
8916 if (inf_state
->siginfo_gdbarch
== gdbarch
)
8918 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8920 /* Errors ignored. */
8921 target_write (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8922 inf_state
->siginfo_data
, 0, TYPE_LENGTH (type
));
8925 /* The inferior can be gone if the user types "print exit(0)"
8926 (and perhaps other times). */
8927 if (target_has_execution
)
8928 /* NB: The register write goes through to the target. */
8929 regcache_cpy (regcache
, inf_state
->registers
);
8931 discard_infcall_suspend_state (inf_state
);
8935 do_restore_infcall_suspend_state_cleanup (void *state
)
8937 restore_infcall_suspend_state ((struct infcall_suspend_state
*) state
);
8941 make_cleanup_restore_infcall_suspend_state
8942 (struct infcall_suspend_state
*inf_state
)
8944 return make_cleanup (do_restore_infcall_suspend_state_cleanup
, inf_state
);
8948 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8950 regcache_xfree (inf_state
->registers
);
8951 xfree (inf_state
->siginfo_data
);
8956 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8958 return inf_state
->registers
;
8961 /* infcall_control_state contains state regarding gdb's control of the
8962 inferior itself like stepping control. It also contains session state like
8963 the user's currently selected frame. */
8965 struct infcall_control_state
8967 struct thread_control_state thread_control
;
8968 struct inferior_control_state inferior_control
;
8971 enum stop_stack_kind stop_stack_dummy
;
8972 int stopped_by_random_signal
;
8974 /* ID if the selected frame when the inferior function call was made. */
8975 struct frame_id selected_frame_id
;
8978 /* Save all of the information associated with the inferior<==>gdb
8981 struct infcall_control_state
*
8982 save_infcall_control_state (void)
8984 struct infcall_control_state
*inf_status
=
8985 XNEW (struct infcall_control_state
);
8986 struct thread_info
*tp
= inferior_thread ();
8987 struct inferior
*inf
= current_inferior ();
8989 inf_status
->thread_control
= tp
->control
;
8990 inf_status
->inferior_control
= inf
->control
;
8992 tp
->control
.step_resume_breakpoint
= NULL
;
8993 tp
->control
.exception_resume_breakpoint
= NULL
;
8995 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8996 chain. If caller's caller is walking the chain, they'll be happier if we
8997 hand them back the original chain when restore_infcall_control_state is
8999 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9002 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9003 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9005 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9011 restore_selected_frame (void *args
)
9013 struct frame_id
*fid
= (struct frame_id
*) args
;
9014 struct frame_info
*frame
;
9016 frame
= frame_find_by_id (*fid
);
9018 /* If inf_status->selected_frame_id is NULL, there was no previously
9022 warning (_("Unable to restore previously selected frame."));
9026 select_frame (frame
);
9031 /* Restore inferior session state to INF_STATUS. */
9034 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9036 struct thread_info
*tp
= inferior_thread ();
9037 struct inferior
*inf
= current_inferior ();
9039 if (tp
->control
.step_resume_breakpoint
)
9040 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9042 if (tp
->control
.exception_resume_breakpoint
)
9043 tp
->control
.exception_resume_breakpoint
->disposition
9044 = disp_del_at_next_stop
;
9046 /* Handle the bpstat_copy of the chain. */
9047 bpstat_clear (&tp
->control
.stop_bpstat
);
9049 tp
->control
= inf_status
->thread_control
;
9050 inf
->control
= inf_status
->inferior_control
;
9053 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9054 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9056 if (target_has_stack
)
9058 /* The point of catch_errors is that if the stack is clobbered,
9059 walking the stack might encounter a garbage pointer and
9060 error() trying to dereference it. */
9062 (restore_selected_frame
, &inf_status
->selected_frame_id
,
9063 "Unable to restore previously selected frame:\n",
9064 RETURN_MASK_ERROR
) == 0)
9065 /* Error in restoring the selected frame. Select the innermost
9067 select_frame (get_current_frame ());
9074 do_restore_infcall_control_state_cleanup (void *sts
)
9076 restore_infcall_control_state ((struct infcall_control_state
*) sts
);
9080 make_cleanup_restore_infcall_control_state
9081 (struct infcall_control_state
*inf_status
)
9083 return make_cleanup (do_restore_infcall_control_state_cleanup
, inf_status
);
9087 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9089 if (inf_status
->thread_control
.step_resume_breakpoint
)
9090 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9091 = disp_del_at_next_stop
;
9093 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9094 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9095 = disp_del_at_next_stop
;
9097 /* See save_infcall_control_state for info on stop_bpstat. */
9098 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9103 /* restore_inferior_ptid() will be used by the cleanup machinery
9104 to restore the inferior_ptid value saved in a call to
9105 save_inferior_ptid(). */
9108 restore_inferior_ptid (void *arg
)
9110 ptid_t
*saved_ptid_ptr
= (ptid_t
*) arg
;
9112 inferior_ptid
= *saved_ptid_ptr
;
9116 /* Save the value of inferior_ptid so that it may be restored by a
9117 later call to do_cleanups(). Returns the struct cleanup pointer
9118 needed for later doing the cleanup. */
9121 save_inferior_ptid (void)
9123 ptid_t
*saved_ptid_ptr
= XNEW (ptid_t
);
9125 *saved_ptid_ptr
= inferior_ptid
;
9126 return make_cleanup (restore_inferior_ptid
, saved_ptid_ptr
);
9132 clear_exit_convenience_vars (void)
9134 clear_internalvar (lookup_internalvar ("_exitsignal"));
9135 clear_internalvar (lookup_internalvar ("_exitcode"));
9139 /* User interface for reverse debugging:
9140 Set exec-direction / show exec-direction commands
9141 (returns error unless target implements to_set_exec_direction method). */
9143 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9144 static const char exec_forward
[] = "forward";
9145 static const char exec_reverse
[] = "reverse";
9146 static const char *exec_direction
= exec_forward
;
9147 static const char *const exec_direction_names
[] = {
9154 set_exec_direction_func (char *args
, int from_tty
,
9155 struct cmd_list_element
*cmd
)
9157 if (target_can_execute_reverse
)
9159 if (!strcmp (exec_direction
, exec_forward
))
9160 execution_direction
= EXEC_FORWARD
;
9161 else if (!strcmp (exec_direction
, exec_reverse
))
9162 execution_direction
= EXEC_REVERSE
;
9166 exec_direction
= exec_forward
;
9167 error (_("Target does not support this operation."));
9172 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9173 struct cmd_list_element
*cmd
, const char *value
)
9175 switch (execution_direction
) {
9177 fprintf_filtered (out
, _("Forward.\n"));
9180 fprintf_filtered (out
, _("Reverse.\n"));
9183 internal_error (__FILE__
, __LINE__
,
9184 _("bogus execution_direction value: %d"),
9185 (int) execution_direction
);
9190 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9191 struct cmd_list_element
*c
, const char *value
)
9193 fprintf_filtered (file
, _("Resuming the execution of threads "
9194 "of all processes is %s.\n"), value
);
9197 /* Implementation of `siginfo' variable. */
9199 static const struct internalvar_funcs siginfo_funcs
=
9206 /* Callback for infrun's target events source. This is marked when a
9207 thread has a pending status to process. */
9210 infrun_async_inferior_event_handler (gdb_client_data data
)
9212 inferior_event_handler (INF_REG_EVENT
, NULL
);
9216 _initialize_infrun (void)
9220 struct cmd_list_element
*c
;
9222 /* Register extra event sources in the event loop. */
9223 infrun_async_inferior_event_token
9224 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9226 add_info ("signals", signals_info
, _("\
9227 What debugger does when program gets various signals.\n\
9228 Specify a signal as argument to print info on that signal only."));
9229 add_info_alias ("handle", "signals", 0);
9231 c
= add_com ("handle", class_run
, handle_command
, _("\
9232 Specify how to handle signals.\n\
9233 Usage: handle SIGNAL [ACTIONS]\n\
9234 Args are signals and actions to apply to those signals.\n\
9235 If no actions are specified, the current settings for the specified signals\n\
9236 will be displayed instead.\n\
9238 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9239 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9240 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9241 The special arg \"all\" is recognized to mean all signals except those\n\
9242 used by the debugger, typically SIGTRAP and SIGINT.\n\
9244 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9245 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9246 Stop means reenter debugger if this signal happens (implies print).\n\
9247 Print means print a message if this signal happens.\n\
9248 Pass means let program see this signal; otherwise program doesn't know.\n\
9249 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9250 Pass and Stop may be combined.\n\
9252 Multiple signals may be specified. Signal numbers and signal names\n\
9253 may be interspersed with actions, with the actions being performed for\n\
9254 all signals cumulatively specified."));
9255 set_cmd_completer (c
, handle_completer
);
9258 stop_command
= add_cmd ("stop", class_obscure
,
9259 not_just_help_class_command
, _("\
9260 There is no `stop' command, but you can set a hook on `stop'.\n\
9261 This allows you to set a list of commands to be run each time execution\n\
9262 of the program stops."), &cmdlist
);
9264 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9265 Set inferior debugging."), _("\
9266 Show inferior debugging."), _("\
9267 When non-zero, inferior specific debugging is enabled."),
9270 &setdebuglist
, &showdebuglist
);
9272 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9273 &debug_displaced
, _("\
9274 Set displaced stepping debugging."), _("\
9275 Show displaced stepping debugging."), _("\
9276 When non-zero, displaced stepping specific debugging is enabled."),
9278 show_debug_displaced
,
9279 &setdebuglist
, &showdebuglist
);
9281 add_setshow_boolean_cmd ("non-stop", no_class
,
9283 Set whether gdb controls the inferior in non-stop mode."), _("\
9284 Show whether gdb controls the inferior in non-stop mode."), _("\
9285 When debugging a multi-threaded program and this setting is\n\
9286 off (the default, also called all-stop mode), when one thread stops\n\
9287 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9288 all other threads in the program while you interact with the thread of\n\
9289 interest. When you continue or step a thread, you can allow the other\n\
9290 threads to run, or have them remain stopped, but while you inspect any\n\
9291 thread's state, all threads stop.\n\
9293 In non-stop mode, when one thread stops, other threads can continue\n\
9294 to run freely. You'll be able to step each thread independently,\n\
9295 leave it stopped or free to run as needed."),
9301 numsigs
= (int) GDB_SIGNAL_LAST
;
9302 signal_stop
= XNEWVEC (unsigned char, numsigs
);
9303 signal_print
= XNEWVEC (unsigned char, numsigs
);
9304 signal_program
= XNEWVEC (unsigned char, numsigs
);
9305 signal_catch
= XNEWVEC (unsigned char, numsigs
);
9306 signal_pass
= XNEWVEC (unsigned char, numsigs
);
9307 for (i
= 0; i
< numsigs
; i
++)
9310 signal_print
[i
] = 1;
9311 signal_program
[i
] = 1;
9312 signal_catch
[i
] = 0;
9315 /* Signals caused by debugger's own actions should not be given to
9316 the program afterwards.
9318 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9319 explicitly specifies that it should be delivered to the target
9320 program. Typically, that would occur when a user is debugging a
9321 target monitor on a simulator: the target monitor sets a
9322 breakpoint; the simulator encounters this breakpoint and halts
9323 the simulation handing control to GDB; GDB, noting that the stop
9324 address doesn't map to any known breakpoint, returns control back
9325 to the simulator; the simulator then delivers the hardware
9326 equivalent of a GDB_SIGNAL_TRAP to the program being
9328 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9329 signal_program
[GDB_SIGNAL_INT
] = 0;
9331 /* Signals that are not errors should not normally enter the debugger. */
9332 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9333 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9334 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9335 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9336 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9337 signal_print
[GDB_SIGNAL_PROF
] = 0;
9338 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9339 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9340 signal_stop
[GDB_SIGNAL_IO
] = 0;
9341 signal_print
[GDB_SIGNAL_IO
] = 0;
9342 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9343 signal_print
[GDB_SIGNAL_POLL
] = 0;
9344 signal_stop
[GDB_SIGNAL_URG
] = 0;
9345 signal_print
[GDB_SIGNAL_URG
] = 0;
9346 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9347 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9348 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9349 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9351 /* These signals are used internally by user-level thread
9352 implementations. (See signal(5) on Solaris.) Like the above
9353 signals, a healthy program receives and handles them as part of
9354 its normal operation. */
9355 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9356 signal_print
[GDB_SIGNAL_LWP
] = 0;
9357 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9358 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9359 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9360 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9362 /* Update cached state. */
9363 signal_cache_update (-1);
9365 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9366 &stop_on_solib_events
, _("\
9367 Set stopping for shared library events."), _("\
9368 Show stopping for shared library events."), _("\
9369 If nonzero, gdb will give control to the user when the dynamic linker\n\
9370 notifies gdb of shared library events. The most common event of interest\n\
9371 to the user would be loading/unloading of a new library."),
9372 set_stop_on_solib_events
,
9373 show_stop_on_solib_events
,
9374 &setlist
, &showlist
);
9376 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9377 follow_fork_mode_kind_names
,
9378 &follow_fork_mode_string
, _("\
9379 Set debugger response to a program call of fork or vfork."), _("\
9380 Show debugger response to a program call of fork or vfork."), _("\
9381 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9382 parent - the original process is debugged after a fork\n\
9383 child - the new process is debugged after a fork\n\
9384 The unfollowed process will continue to run.\n\
9385 By default, the debugger will follow the parent process."),
9387 show_follow_fork_mode_string
,
9388 &setlist
, &showlist
);
9390 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9391 follow_exec_mode_names
,
9392 &follow_exec_mode_string
, _("\
9393 Set debugger response to a program call of exec."), _("\
9394 Show debugger response to a program call of exec."), _("\
9395 An exec call replaces the program image of a process.\n\
9397 follow-exec-mode can be:\n\
9399 new - the debugger creates a new inferior and rebinds the process\n\
9400 to this new inferior. The program the process was running before\n\
9401 the exec call can be restarted afterwards by restarting the original\n\
9404 same - the debugger keeps the process bound to the same inferior.\n\
9405 The new executable image replaces the previous executable loaded in\n\
9406 the inferior. Restarting the inferior after the exec call restarts\n\
9407 the executable the process was running after the exec call.\n\
9409 By default, the debugger will use the same inferior."),
9411 show_follow_exec_mode_string
,
9412 &setlist
, &showlist
);
9414 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9415 scheduler_enums
, &scheduler_mode
, _("\
9416 Set mode for locking scheduler during execution."), _("\
9417 Show mode for locking scheduler during execution."), _("\
9418 off == no locking (threads may preempt at any time)\n\
9419 on == full locking (no thread except the current thread may run)\n\
9420 This applies to both normal execution and replay mode.\n\
9421 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9422 In this mode, other threads may run during other commands.\n\
9423 This applies to both normal execution and replay mode.\n\
9424 replay == scheduler locked in replay mode and unlocked during normal execution."),
9425 set_schedlock_func
, /* traps on target vector */
9426 show_scheduler_mode
,
9427 &setlist
, &showlist
);
9429 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9430 Set mode for resuming threads of all processes."), _("\
9431 Show mode for resuming threads of all processes."), _("\
9432 When on, execution commands (such as 'continue' or 'next') resume all\n\
9433 threads of all processes. When off (which is the default), execution\n\
9434 commands only resume the threads of the current process. The set of\n\
9435 threads that are resumed is further refined by the scheduler-locking\n\
9436 mode (see help set scheduler-locking)."),
9438 show_schedule_multiple
,
9439 &setlist
, &showlist
);
9441 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9442 Set mode of the step operation."), _("\
9443 Show mode of the step operation."), _("\
9444 When set, doing a step over a function without debug line information\n\
9445 will stop at the first instruction of that function. Otherwise, the\n\
9446 function is skipped and the step command stops at a different source line."),
9448 show_step_stop_if_no_debug
,
9449 &setlist
, &showlist
);
9451 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9452 &can_use_displaced_stepping
, _("\
9453 Set debugger's willingness to use displaced stepping."), _("\
9454 Show debugger's willingness to use displaced stepping."), _("\
9455 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9456 supported by the target architecture. If off, gdb will not use displaced\n\
9457 stepping to step over breakpoints, even if such is supported by the target\n\
9458 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9459 if the target architecture supports it and non-stop mode is active, but will not\n\
9460 use it in all-stop mode (see help set non-stop)."),
9462 show_can_use_displaced_stepping
,
9463 &setlist
, &showlist
);
9465 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9466 &exec_direction
, _("Set direction of execution.\n\
9467 Options are 'forward' or 'reverse'."),
9468 _("Show direction of execution (forward/reverse)."),
9469 _("Tells gdb whether to execute forward or backward."),
9470 set_exec_direction_func
, show_exec_direction_func
,
9471 &setlist
, &showlist
);
9473 /* Set/show detach-on-fork: user-settable mode. */
9475 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9476 Set whether gdb will detach the child of a fork."), _("\
9477 Show whether gdb will detach the child of a fork."), _("\
9478 Tells gdb whether to detach the child of a fork."),
9479 NULL
, NULL
, &setlist
, &showlist
);
9481 /* Set/show disable address space randomization mode. */
9483 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9484 &disable_randomization
, _("\
9485 Set disabling of debuggee's virtual address space randomization."), _("\
9486 Show disabling of debuggee's virtual address space randomization."), _("\
9487 When this mode is on (which is the default), randomization of the virtual\n\
9488 address space is disabled. Standalone programs run with the randomization\n\
9489 enabled by default on some platforms."),
9490 &set_disable_randomization
,
9491 &show_disable_randomization
,
9492 &setlist
, &showlist
);
9494 /* ptid initializations */
9495 inferior_ptid
= null_ptid
;
9496 target_last_wait_ptid
= minus_one_ptid
;
9498 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed
);
9499 observer_attach_thread_stop_requested (infrun_thread_stop_requested
);
9500 observer_attach_thread_exit (infrun_thread_thread_exit
);
9501 observer_attach_inferior_exit (infrun_inferior_exit
);
9503 /* Explicitly create without lookup, since that tries to create a
9504 value with a void typed value, and when we get here, gdbarch
9505 isn't initialized yet. At this point, we're quite sure there
9506 isn't another convenience variable of the same name. */
9507 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9509 add_setshow_boolean_cmd ("observer", no_class
,
9510 &observer_mode_1
, _("\
9511 Set whether gdb controls the inferior in observer mode."), _("\
9512 Show whether gdb controls the inferior in observer mode."), _("\
9513 In observer mode, GDB can get data from the inferior, but not\n\
9514 affect its execution. Registers and memory may not be changed,\n\
9515 breakpoints may not be set, and the program cannot be interrupted\n\