1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2015 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 /* Prototypes for local functions */
66 static void signals_info (char *, int);
68 static void handle_command (char *, int);
70 static void sig_print_info (enum gdb_signal
);
72 static void sig_print_header (void);
74 static void resume_cleanups (void *);
76 static int hook_stop_stub (void *);
78 static int restore_selected_frame (void *);
80 static int follow_fork (void);
82 static int follow_fork_inferior (int follow_child
, int detach_fork
);
84 static void follow_inferior_reset_breakpoints (void);
86 static void set_schedlock_func (char *args
, int from_tty
,
87 struct cmd_list_element
*c
);
89 static int currently_stepping (struct thread_info
*tp
);
91 static void xdb_handle_command (char *args
, int from_tty
);
93 void _initialize_infrun (void);
95 void nullify_last_target_wait_ptid (void);
97 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
99 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
101 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
103 /* When set, stop the 'step' command if we enter a function which has
104 no line number information. The normal behavior is that we step
105 over such function. */
106 int step_stop_if_no_debug
= 0;
108 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
109 struct cmd_list_element
*c
, const char *value
)
111 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
114 /* In asynchronous mode, but simulating synchronous execution. */
116 int sync_execution
= 0;
118 /* proceed and normal_stop use this to notify the user when the
119 inferior stopped in a different thread than it had been running
122 static ptid_t previous_inferior_ptid
;
124 /* If set (default for legacy reasons), when following a fork, GDB
125 will detach from one of the fork branches, child or parent.
126 Exactly which branch is detached depends on 'set follow-fork-mode'
129 static int detach_fork
= 1;
131 int debug_displaced
= 0;
133 show_debug_displaced (struct ui_file
*file
, int from_tty
,
134 struct cmd_list_element
*c
, const char *value
)
136 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
139 unsigned int debug_infrun
= 0;
141 show_debug_infrun (struct ui_file
*file
, int from_tty
,
142 struct cmd_list_element
*c
, const char *value
)
144 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
148 /* Support for disabling address space randomization. */
150 int disable_randomization
= 1;
153 show_disable_randomization (struct ui_file
*file
, int from_tty
,
154 struct cmd_list_element
*c
, const char *value
)
156 if (target_supports_disable_randomization ())
157 fprintf_filtered (file
,
158 _("Disabling randomization of debuggee's "
159 "virtual address space is %s.\n"),
162 fputs_filtered (_("Disabling randomization of debuggee's "
163 "virtual address space is unsupported on\n"
164 "this platform.\n"), file
);
168 set_disable_randomization (char *args
, int from_tty
,
169 struct cmd_list_element
*c
)
171 if (!target_supports_disable_randomization ())
172 error (_("Disabling randomization of debuggee's "
173 "virtual address space is unsupported on\n"
177 /* User interface for non-stop mode. */
180 static int non_stop_1
= 0;
183 set_non_stop (char *args
, int from_tty
,
184 struct cmd_list_element
*c
)
186 if (target_has_execution
)
188 non_stop_1
= non_stop
;
189 error (_("Cannot change this setting while the inferior is running."));
192 non_stop
= non_stop_1
;
196 show_non_stop (struct ui_file
*file
, int from_tty
,
197 struct cmd_list_element
*c
, const char *value
)
199 fprintf_filtered (file
,
200 _("Controlling the inferior in non-stop mode is %s.\n"),
204 /* "Observer mode" is somewhat like a more extreme version of
205 non-stop, in which all GDB operations that might affect the
206 target's execution have been disabled. */
208 int observer_mode
= 0;
209 static int observer_mode_1
= 0;
212 set_observer_mode (char *args
, int from_tty
,
213 struct cmd_list_element
*c
)
215 if (target_has_execution
)
217 observer_mode_1
= observer_mode
;
218 error (_("Cannot change this setting while the inferior is running."));
221 observer_mode
= observer_mode_1
;
223 may_write_registers
= !observer_mode
;
224 may_write_memory
= !observer_mode
;
225 may_insert_breakpoints
= !observer_mode
;
226 may_insert_tracepoints
= !observer_mode
;
227 /* We can insert fast tracepoints in or out of observer mode,
228 but enable them if we're going into this mode. */
230 may_insert_fast_tracepoints
= 1;
231 may_stop
= !observer_mode
;
232 update_target_permissions ();
234 /* Going *into* observer mode we must force non-stop, then
235 going out we leave it that way. */
238 pagination_enabled
= 0;
239 non_stop
= non_stop_1
= 1;
243 printf_filtered (_("Observer mode is now %s.\n"),
244 (observer_mode
? "on" : "off"));
248 show_observer_mode (struct ui_file
*file
, int from_tty
,
249 struct cmd_list_element
*c
, const char *value
)
251 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
254 /* This updates the value of observer mode based on changes in
255 permissions. Note that we are deliberately ignoring the values of
256 may-write-registers and may-write-memory, since the user may have
257 reason to enable these during a session, for instance to turn on a
258 debugging-related global. */
261 update_observer_mode (void)
265 newval
= (!may_insert_breakpoints
266 && !may_insert_tracepoints
267 && may_insert_fast_tracepoints
271 /* Let the user know if things change. */
272 if (newval
!= observer_mode
)
273 printf_filtered (_("Observer mode is now %s.\n"),
274 (newval
? "on" : "off"));
276 observer_mode
= observer_mode_1
= newval
;
279 /* Tables of how to react to signals; the user sets them. */
281 static unsigned char *signal_stop
;
282 static unsigned char *signal_print
;
283 static unsigned char *signal_program
;
285 /* Table of signals that are registered with "catch signal". A
286 non-zero entry indicates that the signal is caught by some "catch
287 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
289 static unsigned char *signal_catch
;
291 /* Table of signals that the target may silently handle.
292 This is automatically determined from the flags above,
293 and simply cached here. */
294 static unsigned char *signal_pass
;
296 #define SET_SIGS(nsigs,sigs,flags) \
298 int signum = (nsigs); \
299 while (signum-- > 0) \
300 if ((sigs)[signum]) \
301 (flags)[signum] = 1; \
304 #define UNSET_SIGS(nsigs,sigs,flags) \
306 int signum = (nsigs); \
307 while (signum-- > 0) \
308 if ((sigs)[signum]) \
309 (flags)[signum] = 0; \
312 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
313 this function is to avoid exporting `signal_program'. */
316 update_signals_program_target (void)
318 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
321 /* Value to pass to target_resume() to cause all threads to resume. */
323 #define RESUME_ALL minus_one_ptid
325 /* Command list pointer for the "stop" placeholder. */
327 static struct cmd_list_element
*stop_command
;
329 /* Nonzero if we want to give control to the user when we're notified
330 of shared library events by the dynamic linker. */
331 int stop_on_solib_events
;
333 /* Enable or disable optional shared library event breakpoints
334 as appropriate when the above flag is changed. */
337 set_stop_on_solib_events (char *args
, int from_tty
, struct cmd_list_element
*c
)
339 update_solib_breakpoints ();
343 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
344 struct cmd_list_element
*c
, const char *value
)
346 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
350 /* Nonzero means expecting a trace trap
351 and should stop the inferior and return silently when it happens. */
355 /* Save register contents here when executing a "finish" command or are
356 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
357 Thus this contains the return value from the called function (assuming
358 values are returned in a register). */
360 struct regcache
*stop_registers
;
362 /* Nonzero after stop if current stack frame should be printed. */
364 static int stop_print_frame
;
366 /* This is a cached copy of the pid/waitstatus of the last event
367 returned by target_wait()/deprecated_target_wait_hook(). This
368 information is returned by get_last_target_status(). */
369 static ptid_t target_last_wait_ptid
;
370 static struct target_waitstatus target_last_waitstatus
;
372 static void context_switch (ptid_t ptid
);
374 void init_thread_stepping_state (struct thread_info
*tss
);
376 static const char follow_fork_mode_child
[] = "child";
377 static const char follow_fork_mode_parent
[] = "parent";
379 static const char *const follow_fork_mode_kind_names
[] = {
380 follow_fork_mode_child
,
381 follow_fork_mode_parent
,
385 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
387 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
388 struct cmd_list_element
*c
, const char *value
)
390 fprintf_filtered (file
,
391 _("Debugger response to a program "
392 "call of fork or vfork is \"%s\".\n"),
397 /* Handle changes to the inferior list based on the type of fork,
398 which process is being followed, and whether the other process
399 should be detached. On entry inferior_ptid must be the ptid of
400 the fork parent. At return inferior_ptid is the ptid of the
401 followed inferior. */
404 follow_fork_inferior (int follow_child
, int detach_fork
)
407 ptid_t parent_ptid
, child_ptid
;
409 has_vforked
= (inferior_thread ()->pending_follow
.kind
410 == TARGET_WAITKIND_VFORKED
);
411 parent_ptid
= inferior_ptid
;
412 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
415 && !non_stop
/* Non-stop always resumes both branches. */
416 && (!target_is_async_p () || sync_execution
)
417 && !(follow_child
|| detach_fork
|| sched_multi
))
419 /* The parent stays blocked inside the vfork syscall until the
420 child execs or exits. If we don't let the child run, then
421 the parent stays blocked. If we're telling the parent to run
422 in the foreground, the user will not be able to ctrl-c to get
423 back the terminal, effectively hanging the debug session. */
424 fprintf_filtered (gdb_stderr
, _("\
425 Can not resume the parent process over vfork in the foreground while\n\
426 holding the child stopped. Try \"set detach-on-fork\" or \
427 \"set schedule-multiple\".\n"));
428 /* FIXME output string > 80 columns. */
434 /* Detach new forked process? */
437 struct cleanup
*old_chain
;
439 /* Before detaching from the child, remove all breakpoints
440 from it. If we forked, then this has already been taken
441 care of by infrun.c. If we vforked however, any
442 breakpoint inserted in the parent is visible in the
443 child, even those added while stopped in a vfork
444 catchpoint. This will remove the breakpoints from the
445 parent also, but they'll be reinserted below. */
448 /* Keep breakpoints list in sync. */
449 remove_breakpoints_pid (ptid_get_pid (inferior_ptid
));
452 if (info_verbose
|| debug_infrun
)
454 target_terminal_ours_for_output ();
455 fprintf_filtered (gdb_stdlog
,
456 _("Detaching after %s from child %s.\n"),
457 has_vforked
? "vfork" : "fork",
458 target_pid_to_str (child_ptid
));
463 struct inferior
*parent_inf
, *child_inf
;
464 struct cleanup
*old_chain
;
466 /* Add process to GDB's tables. */
467 child_inf
= add_inferior (ptid_get_pid (child_ptid
));
469 parent_inf
= current_inferior ();
470 child_inf
->attach_flag
= parent_inf
->attach_flag
;
471 copy_terminal_info (child_inf
, parent_inf
);
472 child_inf
->gdbarch
= parent_inf
->gdbarch
;
473 copy_inferior_target_desc_info (child_inf
, parent_inf
);
475 old_chain
= save_inferior_ptid ();
476 save_current_program_space ();
478 inferior_ptid
= child_ptid
;
479 add_thread (inferior_ptid
);
480 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
482 /* If this is a vfork child, then the address-space is
483 shared with the parent. */
486 child_inf
->pspace
= parent_inf
->pspace
;
487 child_inf
->aspace
= parent_inf
->aspace
;
489 /* The parent will be frozen until the child is done
490 with the shared region. Keep track of the
492 child_inf
->vfork_parent
= parent_inf
;
493 child_inf
->pending_detach
= 0;
494 parent_inf
->vfork_child
= child_inf
;
495 parent_inf
->pending_detach
= 0;
499 child_inf
->aspace
= new_address_space ();
500 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
501 child_inf
->removable
= 1;
502 set_current_program_space (child_inf
->pspace
);
503 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
505 /* Let the shared library layer (e.g., solib-svr4) learn
506 about this new process, relocate the cloned exec, pull
507 in shared libraries, and install the solib event
508 breakpoint. If a "cloned-VM" event was propagated
509 better throughout the core, this wouldn't be
511 solib_create_inferior_hook (0);
514 do_cleanups (old_chain
);
519 struct inferior
*parent_inf
;
521 parent_inf
= current_inferior ();
523 /* If we detached from the child, then we have to be careful
524 to not insert breakpoints in the parent until the child
525 is done with the shared memory region. However, if we're
526 staying attached to the child, then we can and should
527 insert breakpoints, so that we can debug it. A
528 subsequent child exec or exit is enough to know when does
529 the child stops using the parent's address space. */
530 parent_inf
->waiting_for_vfork_done
= detach_fork
;
531 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
536 /* Follow the child. */
537 struct inferior
*parent_inf
, *child_inf
;
538 struct program_space
*parent_pspace
;
540 if (info_verbose
|| debug_infrun
)
542 target_terminal_ours_for_output ();
543 fprintf_filtered (gdb_stdlog
,
544 _("Attaching after %s %s to child %s.\n"),
545 target_pid_to_str (parent_ptid
),
546 has_vforked
? "vfork" : "fork",
547 target_pid_to_str (child_ptid
));
550 /* Add the new inferior first, so that the target_detach below
551 doesn't unpush the target. */
553 child_inf
= add_inferior (ptid_get_pid (child_ptid
));
555 parent_inf
= current_inferior ();
556 child_inf
->attach_flag
= parent_inf
->attach_flag
;
557 copy_terminal_info (child_inf
, parent_inf
);
558 child_inf
->gdbarch
= parent_inf
->gdbarch
;
559 copy_inferior_target_desc_info (child_inf
, parent_inf
);
561 parent_pspace
= parent_inf
->pspace
;
563 /* If we're vforking, we want to hold on to the parent until the
564 child exits or execs. At child exec or exit time we can
565 remove the old breakpoints from the parent and detach or
566 resume debugging it. Otherwise, detach the parent now; we'll
567 want to reuse it's program/address spaces, but we can't set
568 them to the child before removing breakpoints from the
569 parent, otherwise, the breakpoints module could decide to
570 remove breakpoints from the wrong process (since they'd be
571 assigned to the same address space). */
575 gdb_assert (child_inf
->vfork_parent
== NULL
);
576 gdb_assert (parent_inf
->vfork_child
== NULL
);
577 child_inf
->vfork_parent
= parent_inf
;
578 child_inf
->pending_detach
= 0;
579 parent_inf
->vfork_child
= child_inf
;
580 parent_inf
->pending_detach
= detach_fork
;
581 parent_inf
->waiting_for_vfork_done
= 0;
583 else if (detach_fork
)
585 if (info_verbose
|| debug_infrun
)
587 target_terminal_ours_for_output ();
588 fprintf_filtered (gdb_stdlog
,
589 _("Detaching after fork from "
591 target_pid_to_str (child_ptid
));
594 target_detach (NULL
, 0);
597 /* Note that the detach above makes PARENT_INF dangling. */
599 /* Add the child thread to the appropriate lists, and switch to
600 this new thread, before cloning the program space, and
601 informing the solib layer about this new process. */
603 inferior_ptid
= child_ptid
;
604 add_thread (inferior_ptid
);
606 /* If this is a vfork child, then the address-space is shared
607 with the parent. If we detached from the parent, then we can
608 reuse the parent's program/address spaces. */
609 if (has_vforked
|| detach_fork
)
611 child_inf
->pspace
= parent_pspace
;
612 child_inf
->aspace
= child_inf
->pspace
->aspace
;
616 child_inf
->aspace
= new_address_space ();
617 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
618 child_inf
->removable
= 1;
619 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
620 set_current_program_space (child_inf
->pspace
);
621 clone_program_space (child_inf
->pspace
, parent_pspace
);
623 /* Let the shared library layer (e.g., solib-svr4) learn
624 about this new process, relocate the cloned exec, pull in
625 shared libraries, and install the solib event breakpoint.
626 If a "cloned-VM" event was propagated better throughout
627 the core, this wouldn't be required. */
628 solib_create_inferior_hook (0);
632 return target_follow_fork (follow_child
, detach_fork
);
635 /* Tell the target to follow the fork we're stopped at. Returns true
636 if the inferior should be resumed; false, if the target for some
637 reason decided it's best not to resume. */
642 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
643 int should_resume
= 1;
644 struct thread_info
*tp
;
646 /* Copy user stepping state to the new inferior thread. FIXME: the
647 followed fork child thread should have a copy of most of the
648 parent thread structure's run control related fields, not just these.
649 Initialized to avoid "may be used uninitialized" warnings from gcc. */
650 struct breakpoint
*step_resume_breakpoint
= NULL
;
651 struct breakpoint
*exception_resume_breakpoint
= NULL
;
652 CORE_ADDR step_range_start
= 0;
653 CORE_ADDR step_range_end
= 0;
654 struct frame_id step_frame_id
= { 0 };
655 struct interp
*command_interp
= NULL
;
660 struct target_waitstatus wait_status
;
662 /* Get the last target status returned by target_wait(). */
663 get_last_target_status (&wait_ptid
, &wait_status
);
665 /* If not stopped at a fork event, then there's nothing else to
667 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
668 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
671 /* Check if we switched over from WAIT_PTID, since the event was
673 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
674 && !ptid_equal (inferior_ptid
, wait_ptid
))
676 /* We did. Switch back to WAIT_PTID thread, to tell the
677 target to follow it (in either direction). We'll
678 afterwards refuse to resume, and inform the user what
680 switch_to_thread (wait_ptid
);
685 tp
= inferior_thread ();
687 /* If there were any forks/vforks that were caught and are now to be
688 followed, then do so now. */
689 switch (tp
->pending_follow
.kind
)
691 case TARGET_WAITKIND_FORKED
:
692 case TARGET_WAITKIND_VFORKED
:
694 ptid_t parent
, child
;
696 /* If the user did a next/step, etc, over a fork call,
697 preserve the stepping state in the fork child. */
698 if (follow_child
&& should_resume
)
700 step_resume_breakpoint
= clone_momentary_breakpoint
701 (tp
->control
.step_resume_breakpoint
);
702 step_range_start
= tp
->control
.step_range_start
;
703 step_range_end
= tp
->control
.step_range_end
;
704 step_frame_id
= tp
->control
.step_frame_id
;
705 exception_resume_breakpoint
706 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
707 command_interp
= tp
->control
.command_interp
;
709 /* For now, delete the parent's sr breakpoint, otherwise,
710 parent/child sr breakpoints are considered duplicates,
711 and the child version will not be installed. Remove
712 this when the breakpoints module becomes aware of
713 inferiors and address spaces. */
714 delete_step_resume_breakpoint (tp
);
715 tp
->control
.step_range_start
= 0;
716 tp
->control
.step_range_end
= 0;
717 tp
->control
.step_frame_id
= null_frame_id
;
718 delete_exception_resume_breakpoint (tp
);
719 tp
->control
.command_interp
= NULL
;
722 parent
= inferior_ptid
;
723 child
= tp
->pending_follow
.value
.related_pid
;
725 /* Set up inferior(s) as specified by the caller, and tell the
726 target to do whatever is necessary to follow either parent
728 if (follow_fork_inferior (follow_child
, detach_fork
))
730 /* Target refused to follow, or there's some other reason
731 we shouldn't resume. */
736 /* This pending follow fork event is now handled, one way
737 or another. The previous selected thread may be gone
738 from the lists by now, but if it is still around, need
739 to clear the pending follow request. */
740 tp
= find_thread_ptid (parent
);
742 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
744 /* This makes sure we don't try to apply the "Switched
745 over from WAIT_PID" logic above. */
746 nullify_last_target_wait_ptid ();
748 /* If we followed the child, switch to it... */
751 switch_to_thread (child
);
753 /* ... and preserve the stepping state, in case the
754 user was stepping over the fork call. */
757 tp
= inferior_thread ();
758 tp
->control
.step_resume_breakpoint
759 = step_resume_breakpoint
;
760 tp
->control
.step_range_start
= step_range_start
;
761 tp
->control
.step_range_end
= step_range_end
;
762 tp
->control
.step_frame_id
= step_frame_id
;
763 tp
->control
.exception_resume_breakpoint
764 = exception_resume_breakpoint
;
765 tp
->control
.command_interp
= command_interp
;
769 /* If we get here, it was because we're trying to
770 resume from a fork catchpoint, but, the user
771 has switched threads away from the thread that
772 forked. In that case, the resume command
773 issued is most likely not applicable to the
774 child, so just warn, and refuse to resume. */
775 warning (_("Not resuming: switched threads "
776 "before following fork child.\n"));
779 /* Reset breakpoints in the child as appropriate. */
780 follow_inferior_reset_breakpoints ();
783 switch_to_thread (parent
);
787 case TARGET_WAITKIND_SPURIOUS
:
788 /* Nothing to follow. */
791 internal_error (__FILE__
, __LINE__
,
792 "Unexpected pending_follow.kind %d\n",
793 tp
->pending_follow
.kind
);
797 return should_resume
;
801 follow_inferior_reset_breakpoints (void)
803 struct thread_info
*tp
= inferior_thread ();
805 /* Was there a step_resume breakpoint? (There was if the user
806 did a "next" at the fork() call.) If so, explicitly reset its
807 thread number. Cloned step_resume breakpoints are disabled on
808 creation, so enable it here now that it is associated with the
811 step_resumes are a form of bp that are made to be per-thread.
812 Since we created the step_resume bp when the parent process
813 was being debugged, and now are switching to the child process,
814 from the breakpoint package's viewpoint, that's a switch of
815 "threads". We must update the bp's notion of which thread
816 it is for, or it'll be ignored when it triggers. */
818 if (tp
->control
.step_resume_breakpoint
)
820 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
821 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
824 /* Treat exception_resume breakpoints like step_resume breakpoints. */
825 if (tp
->control
.exception_resume_breakpoint
)
827 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
828 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
831 /* Reinsert all breakpoints in the child. The user may have set
832 breakpoints after catching the fork, in which case those
833 were never set in the child, but only in the parent. This makes
834 sure the inserted breakpoints match the breakpoint list. */
836 breakpoint_re_set ();
837 insert_breakpoints ();
840 /* The child has exited or execed: resume threads of the parent the
841 user wanted to be executing. */
844 proceed_after_vfork_done (struct thread_info
*thread
,
847 int pid
= * (int *) arg
;
849 if (ptid_get_pid (thread
->ptid
) == pid
850 && is_running (thread
->ptid
)
851 && !is_executing (thread
->ptid
)
852 && !thread
->stop_requested
853 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
856 fprintf_unfiltered (gdb_stdlog
,
857 "infrun: resuming vfork parent thread %s\n",
858 target_pid_to_str (thread
->ptid
));
860 switch_to_thread (thread
->ptid
);
861 clear_proceed_status (0);
862 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
, 0);
868 /* Called whenever we notice an exec or exit event, to handle
869 detaching or resuming a vfork parent. */
872 handle_vfork_child_exec_or_exit (int exec
)
874 struct inferior
*inf
= current_inferior ();
876 if (inf
->vfork_parent
)
878 int resume_parent
= -1;
880 /* This exec or exit marks the end of the shared memory region
881 between the parent and the child. If the user wanted to
882 detach from the parent, now is the time. */
884 if (inf
->vfork_parent
->pending_detach
)
886 struct thread_info
*tp
;
887 struct cleanup
*old_chain
;
888 struct program_space
*pspace
;
889 struct address_space
*aspace
;
891 /* follow-fork child, detach-on-fork on. */
893 inf
->vfork_parent
->pending_detach
= 0;
897 /* If we're handling a child exit, then inferior_ptid
898 points at the inferior's pid, not to a thread. */
899 old_chain
= save_inferior_ptid ();
900 save_current_program_space ();
901 save_current_inferior ();
904 old_chain
= save_current_space_and_thread ();
906 /* We're letting loose of the parent. */
907 tp
= any_live_thread_of_process (inf
->vfork_parent
->pid
);
908 switch_to_thread (tp
->ptid
);
910 /* We're about to detach from the parent, which implicitly
911 removes breakpoints from its address space. There's a
912 catch here: we want to reuse the spaces for the child,
913 but, parent/child are still sharing the pspace at this
914 point, although the exec in reality makes the kernel give
915 the child a fresh set of new pages. The problem here is
916 that the breakpoints module being unaware of this, would
917 likely chose the child process to write to the parent
918 address space. Swapping the child temporarily away from
919 the spaces has the desired effect. Yes, this is "sort
922 pspace
= inf
->pspace
;
923 aspace
= inf
->aspace
;
927 if (debug_infrun
|| info_verbose
)
929 target_terminal_ours_for_output ();
933 fprintf_filtered (gdb_stdlog
,
934 _("Detaching vfork parent process "
935 "%d after child exec.\n"),
936 inf
->vfork_parent
->pid
);
940 fprintf_filtered (gdb_stdlog
,
941 _("Detaching vfork parent process "
942 "%d after child exit.\n"),
943 inf
->vfork_parent
->pid
);
947 target_detach (NULL
, 0);
950 inf
->pspace
= pspace
;
951 inf
->aspace
= aspace
;
953 do_cleanups (old_chain
);
957 /* We're staying attached to the parent, so, really give the
958 child a new address space. */
959 inf
->pspace
= add_program_space (maybe_new_address_space ());
960 inf
->aspace
= inf
->pspace
->aspace
;
962 set_current_program_space (inf
->pspace
);
964 resume_parent
= inf
->vfork_parent
->pid
;
966 /* Break the bonds. */
967 inf
->vfork_parent
->vfork_child
= NULL
;
971 struct cleanup
*old_chain
;
972 struct program_space
*pspace
;
974 /* If this is a vfork child exiting, then the pspace and
975 aspaces were shared with the parent. Since we're
976 reporting the process exit, we'll be mourning all that is
977 found in the address space, and switching to null_ptid,
978 preparing to start a new inferior. But, since we don't
979 want to clobber the parent's address/program spaces, we
980 go ahead and create a new one for this exiting
983 /* Switch to null_ptid, so that clone_program_space doesn't want
984 to read the selected frame of a dead process. */
985 old_chain
= save_inferior_ptid ();
986 inferior_ptid
= null_ptid
;
988 /* This inferior is dead, so avoid giving the breakpoints
989 module the option to write through to it (cloning a
990 program space resets breakpoints). */
993 pspace
= add_program_space (maybe_new_address_space ());
994 set_current_program_space (pspace
);
996 inf
->symfile_flags
= SYMFILE_NO_READ
;
997 clone_program_space (pspace
, inf
->vfork_parent
->pspace
);
998 inf
->pspace
= pspace
;
999 inf
->aspace
= pspace
->aspace
;
1001 /* Put back inferior_ptid. We'll continue mourning this
1003 do_cleanups (old_chain
);
1005 resume_parent
= inf
->vfork_parent
->pid
;
1006 /* Break the bonds. */
1007 inf
->vfork_parent
->vfork_child
= NULL
;
1010 inf
->vfork_parent
= NULL
;
1012 gdb_assert (current_program_space
== inf
->pspace
);
1014 if (non_stop
&& resume_parent
!= -1)
1016 /* If the user wanted the parent to be running, let it go
1018 struct cleanup
*old_chain
= make_cleanup_restore_current_thread ();
1021 fprintf_unfiltered (gdb_stdlog
,
1022 "infrun: resuming vfork parent process %d\n",
1025 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1027 do_cleanups (old_chain
);
1032 /* Enum strings for "set|show follow-exec-mode". */
1034 static const char follow_exec_mode_new
[] = "new";
1035 static const char follow_exec_mode_same
[] = "same";
1036 static const char *const follow_exec_mode_names
[] =
1038 follow_exec_mode_new
,
1039 follow_exec_mode_same
,
1043 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1045 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1046 struct cmd_list_element
*c
, const char *value
)
1048 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1051 /* EXECD_PATHNAME is assumed to be non-NULL. */
1054 follow_exec (ptid_t ptid
, char *execd_pathname
)
1056 struct thread_info
*th
, *tmp
;
1057 struct inferior
*inf
= current_inferior ();
1058 int pid
= ptid_get_pid (ptid
);
1060 /* This is an exec event that we actually wish to pay attention to.
1061 Refresh our symbol table to the newly exec'd program, remove any
1062 momentary bp's, etc.
1064 If there are breakpoints, they aren't really inserted now,
1065 since the exec() transformed our inferior into a fresh set
1068 We want to preserve symbolic breakpoints on the list, since
1069 we have hopes that they can be reset after the new a.out's
1070 symbol table is read.
1072 However, any "raw" breakpoints must be removed from the list
1073 (e.g., the solib bp's), since their address is probably invalid
1076 And, we DON'T want to call delete_breakpoints() here, since
1077 that may write the bp's "shadow contents" (the instruction
1078 value that was overwritten witha TRAP instruction). Since
1079 we now have a new a.out, those shadow contents aren't valid. */
1081 mark_breakpoints_out ();
1083 /* The target reports the exec event to the main thread, even if
1084 some other thread does the exec, and even if the main thread was
1085 stopped or already gone. We may still have non-leader threads of
1086 the process on our list. E.g., on targets that don't have thread
1087 exit events (like remote); or on native Linux in non-stop mode if
1088 there were only two threads in the inferior and the non-leader
1089 one is the one that execs (and nothing forces an update of the
1090 thread list up to here). When debugging remotely, it's best to
1091 avoid extra traffic, when possible, so avoid syncing the thread
1092 list with the target, and instead go ahead and delete all threads
1093 of the process but one that reported the event. Note this must
1094 be done before calling update_breakpoints_after_exec, as
1095 otherwise clearing the threads' resources would reference stale
1096 thread breakpoints -- it may have been one of these threads that
1097 stepped across the exec. We could just clear their stepping
1098 states, but as long as we're iterating, might as well delete
1099 them. Deleting them now rather than at the next user-visible
1100 stop provides a nicer sequence of events for user and MI
1102 ALL_NON_EXITED_THREADS_SAFE (th
, tmp
)
1103 if (ptid_get_pid (th
->ptid
) == pid
&& !ptid_equal (th
->ptid
, ptid
))
1104 delete_thread (th
->ptid
);
1106 /* We also need to clear any left over stale state for the
1107 leader/event thread. E.g., if there was any step-resume
1108 breakpoint or similar, it's gone now. We cannot truly
1109 step-to-next statement through an exec(). */
1110 th
= inferior_thread ();
1111 th
->control
.step_resume_breakpoint
= NULL
;
1112 th
->control
.exception_resume_breakpoint
= NULL
;
1113 th
->control
.single_step_breakpoints
= NULL
;
1114 th
->control
.step_range_start
= 0;
1115 th
->control
.step_range_end
= 0;
1117 /* The user may have had the main thread held stopped in the
1118 previous image (e.g., schedlock on, or non-stop). Release
1120 th
->stop_requested
= 0;
1122 update_breakpoints_after_exec ();
1124 /* What is this a.out's name? */
1125 printf_unfiltered (_("%s is executing new program: %s\n"),
1126 target_pid_to_str (inferior_ptid
),
1129 /* We've followed the inferior through an exec. Therefore, the
1130 inferior has essentially been killed & reborn. */
1132 gdb_flush (gdb_stdout
);
1134 breakpoint_init_inferior (inf_execd
);
1136 if (gdb_sysroot
&& *gdb_sysroot
)
1138 char *name
= alloca (strlen (gdb_sysroot
)
1139 + strlen (execd_pathname
)
1142 strcpy (name
, gdb_sysroot
);
1143 strcat (name
, execd_pathname
);
1144 execd_pathname
= name
;
1147 /* Reset the shared library package. This ensures that we get a
1148 shlib event when the child reaches "_start", at which point the
1149 dld will have had a chance to initialize the child. */
1150 /* Also, loading a symbol file below may trigger symbol lookups, and
1151 we don't want those to be satisfied by the libraries of the
1152 previous incarnation of this process. */
1153 no_shared_libraries (NULL
, 0);
1155 if (follow_exec_mode_string
== follow_exec_mode_new
)
1157 struct program_space
*pspace
;
1159 /* The user wants to keep the old inferior and program spaces
1160 around. Create a new fresh one, and switch to it. */
1162 inf
= add_inferior (current_inferior ()->pid
);
1163 pspace
= add_program_space (maybe_new_address_space ());
1164 inf
->pspace
= pspace
;
1165 inf
->aspace
= pspace
->aspace
;
1167 exit_inferior_num_silent (current_inferior ()->num
);
1169 set_current_inferior (inf
);
1170 set_current_program_space (pspace
);
1174 /* The old description may no longer be fit for the new image.
1175 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1176 old description; we'll read a new one below. No need to do
1177 this on "follow-exec-mode new", as the old inferior stays
1178 around (its description is later cleared/refetched on
1180 target_clear_description ();
1183 gdb_assert (current_program_space
== inf
->pspace
);
1185 /* That a.out is now the one to use. */
1186 exec_file_attach (execd_pathname
, 0);
1188 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
1189 (Position Independent Executable) main symbol file will get applied by
1190 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
1191 the breakpoints with the zero displacement. */
1193 symbol_file_add (execd_pathname
,
1195 | SYMFILE_MAINLINE
| SYMFILE_DEFER_BP_RESET
),
1198 if ((inf
->symfile_flags
& SYMFILE_NO_READ
) == 0)
1199 set_initial_language ();
1201 /* If the target can specify a description, read it. Must do this
1202 after flipping to the new executable (because the target supplied
1203 description must be compatible with the executable's
1204 architecture, and the old executable may e.g., be 32-bit, while
1205 the new one 64-bit), and before anything involving memory or
1207 target_find_description ();
1209 solib_create_inferior_hook (0);
1211 jit_inferior_created_hook ();
1213 breakpoint_re_set ();
1215 /* Reinsert all breakpoints. (Those which were symbolic have
1216 been reset to the proper address in the new a.out, thanks
1217 to symbol_file_command...). */
1218 insert_breakpoints ();
1220 /* The next resume of this inferior should bring it to the shlib
1221 startup breakpoints. (If the user had also set bp's on
1222 "main" from the old (parent) process, then they'll auto-
1223 matically get reset there in the new process.). */
1226 /* Info about an instruction that is being stepped over. */
1228 struct step_over_info
1230 /* If we're stepping past a breakpoint, this is the address space
1231 and address of the instruction the breakpoint is set at. We'll
1232 skip inserting all breakpoints here. Valid iff ASPACE is
1234 struct address_space
*aspace
;
1237 /* The instruction being stepped over triggers a nonsteppable
1238 watchpoint. If true, we'll skip inserting watchpoints. */
1239 int nonsteppable_watchpoint_p
;
1242 /* The step-over info of the location that is being stepped over.
1244 Note that with async/breakpoint always-inserted mode, a user might
1245 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1246 being stepped over. As setting a new breakpoint inserts all
1247 breakpoints, we need to make sure the breakpoint being stepped over
1248 isn't inserted then. We do that by only clearing the step-over
1249 info when the step-over is actually finished (or aborted).
1251 Presently GDB can only step over one breakpoint at any given time.
1252 Given threads that can't run code in the same address space as the
1253 breakpoint's can't really miss the breakpoint, GDB could be taught
1254 to step-over at most one breakpoint per address space (so this info
1255 could move to the address space object if/when GDB is extended).
1256 The set of breakpoints being stepped over will normally be much
1257 smaller than the set of all breakpoints, so a flag in the
1258 breakpoint location structure would be wasteful. A separate list
1259 also saves complexity and run-time, as otherwise we'd have to go
1260 through all breakpoint locations clearing their flag whenever we
1261 start a new sequence. Similar considerations weigh against storing
1262 this info in the thread object. Plus, not all step overs actually
1263 have breakpoint locations -- e.g., stepping past a single-step
1264 breakpoint, or stepping to complete a non-continuable
1266 static struct step_over_info step_over_info
;
1268 /* Record the address of the breakpoint/instruction we're currently
1272 set_step_over_info (struct address_space
*aspace
, CORE_ADDR address
,
1273 int nonsteppable_watchpoint_p
)
1275 step_over_info
.aspace
= aspace
;
1276 step_over_info
.address
= address
;
1277 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1280 /* Called when we're not longer stepping over a breakpoint / an
1281 instruction, so all breakpoints are free to be (re)inserted. */
1284 clear_step_over_info (void)
1286 step_over_info
.aspace
= NULL
;
1287 step_over_info
.address
= 0;
1288 step_over_info
.nonsteppable_watchpoint_p
= 0;
1294 stepping_past_instruction_at (struct address_space
*aspace
,
1297 return (step_over_info
.aspace
!= NULL
1298 && breakpoint_address_match (aspace
, address
,
1299 step_over_info
.aspace
,
1300 step_over_info
.address
));
1306 stepping_past_nonsteppable_watchpoint (void)
1308 return step_over_info
.nonsteppable_watchpoint_p
;
1311 /* Returns true if step-over info is valid. */
1314 step_over_info_valid_p (void)
1316 return (step_over_info
.aspace
!= NULL
1317 || stepping_past_nonsteppable_watchpoint ());
1321 /* Displaced stepping. */
1323 /* In non-stop debugging mode, we must take special care to manage
1324 breakpoints properly; in particular, the traditional strategy for
1325 stepping a thread past a breakpoint it has hit is unsuitable.
1326 'Displaced stepping' is a tactic for stepping one thread past a
1327 breakpoint it has hit while ensuring that other threads running
1328 concurrently will hit the breakpoint as they should.
1330 The traditional way to step a thread T off a breakpoint in a
1331 multi-threaded program in all-stop mode is as follows:
1333 a0) Initially, all threads are stopped, and breakpoints are not
1335 a1) We single-step T, leaving breakpoints uninserted.
1336 a2) We insert breakpoints, and resume all threads.
1338 In non-stop debugging, however, this strategy is unsuitable: we
1339 don't want to have to stop all threads in the system in order to
1340 continue or step T past a breakpoint. Instead, we use displaced
1343 n0) Initially, T is stopped, other threads are running, and
1344 breakpoints are inserted.
1345 n1) We copy the instruction "under" the breakpoint to a separate
1346 location, outside the main code stream, making any adjustments
1347 to the instruction, register, and memory state as directed by
1349 n2) We single-step T over the instruction at its new location.
1350 n3) We adjust the resulting register and memory state as directed
1351 by T's architecture. This includes resetting T's PC to point
1352 back into the main instruction stream.
1355 This approach depends on the following gdbarch methods:
1357 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1358 indicate where to copy the instruction, and how much space must
1359 be reserved there. We use these in step n1.
1361 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1362 address, and makes any necessary adjustments to the instruction,
1363 register contents, and memory. We use this in step n1.
1365 - gdbarch_displaced_step_fixup adjusts registers and memory after
1366 we have successfuly single-stepped the instruction, to yield the
1367 same effect the instruction would have had if we had executed it
1368 at its original address. We use this in step n3.
1370 - gdbarch_displaced_step_free_closure provides cleanup.
1372 The gdbarch_displaced_step_copy_insn and
1373 gdbarch_displaced_step_fixup functions must be written so that
1374 copying an instruction with gdbarch_displaced_step_copy_insn,
1375 single-stepping across the copied instruction, and then applying
1376 gdbarch_displaced_insn_fixup should have the same effects on the
1377 thread's memory and registers as stepping the instruction in place
1378 would have. Exactly which responsibilities fall to the copy and
1379 which fall to the fixup is up to the author of those functions.
1381 See the comments in gdbarch.sh for details.
1383 Note that displaced stepping and software single-step cannot
1384 currently be used in combination, although with some care I think
1385 they could be made to. Software single-step works by placing
1386 breakpoints on all possible subsequent instructions; if the
1387 displaced instruction is a PC-relative jump, those breakpoints
1388 could fall in very strange places --- on pages that aren't
1389 executable, or at addresses that are not proper instruction
1390 boundaries. (We do generally let other threads run while we wait
1391 to hit the software single-step breakpoint, and they might
1392 encounter such a corrupted instruction.) One way to work around
1393 this would be to have gdbarch_displaced_step_copy_insn fully
1394 simulate the effect of PC-relative instructions (and return NULL)
1395 on architectures that use software single-stepping.
1397 In non-stop mode, we can have independent and simultaneous step
1398 requests, so more than one thread may need to simultaneously step
1399 over a breakpoint. The current implementation assumes there is
1400 only one scratch space per process. In this case, we have to
1401 serialize access to the scratch space. If thread A wants to step
1402 over a breakpoint, but we are currently waiting for some other
1403 thread to complete a displaced step, we leave thread A stopped and
1404 place it in the displaced_step_request_queue. Whenever a displaced
1405 step finishes, we pick the next thread in the queue and start a new
1406 displaced step operation on it. See displaced_step_prepare and
1407 displaced_step_fixup for details. */
1409 struct displaced_step_request
1412 struct displaced_step_request
*next
;
1415 /* Per-inferior displaced stepping state. */
1416 struct displaced_step_inferior_state
1418 /* Pointer to next in linked list. */
1419 struct displaced_step_inferior_state
*next
;
1421 /* The process this displaced step state refers to. */
1424 /* A queue of pending displaced stepping requests. One entry per
1425 thread that needs to do a displaced step. */
1426 struct displaced_step_request
*step_request_queue
;
1428 /* If this is not null_ptid, this is the thread carrying out a
1429 displaced single-step in process PID. This thread's state will
1430 require fixing up once it has completed its step. */
1433 /* The architecture the thread had when we stepped it. */
1434 struct gdbarch
*step_gdbarch
;
1436 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1437 for post-step cleanup. */
1438 struct displaced_step_closure
*step_closure
;
1440 /* The address of the original instruction, and the copy we
1442 CORE_ADDR step_original
, step_copy
;
1444 /* Saved contents of copy area. */
1445 gdb_byte
*step_saved_copy
;
1448 /* The list of states of processes involved in displaced stepping
1450 static struct displaced_step_inferior_state
*displaced_step_inferior_states
;
1452 /* Get the displaced stepping state of process PID. */
1454 static struct displaced_step_inferior_state
*
1455 get_displaced_stepping_state (int pid
)
1457 struct displaced_step_inferior_state
*state
;
1459 for (state
= displaced_step_inferior_states
;
1461 state
= state
->next
)
1462 if (state
->pid
== pid
)
1468 /* Add a new displaced stepping state for process PID to the displaced
1469 stepping state list, or return a pointer to an already existing
1470 entry, if it already exists. Never returns NULL. */
1472 static struct displaced_step_inferior_state
*
1473 add_displaced_stepping_state (int pid
)
1475 struct displaced_step_inferior_state
*state
;
1477 for (state
= displaced_step_inferior_states
;
1479 state
= state
->next
)
1480 if (state
->pid
== pid
)
1483 state
= xcalloc (1, sizeof (*state
));
1485 state
->next
= displaced_step_inferior_states
;
1486 displaced_step_inferior_states
= state
;
1491 /* If inferior is in displaced stepping, and ADDR equals to starting address
1492 of copy area, return corresponding displaced_step_closure. Otherwise,
1495 struct displaced_step_closure
*
1496 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1498 struct displaced_step_inferior_state
*displaced
1499 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
1501 /* If checking the mode of displaced instruction in copy area. */
1502 if (displaced
&& !ptid_equal (displaced
->step_ptid
, null_ptid
)
1503 && (displaced
->step_copy
== addr
))
1504 return displaced
->step_closure
;
1509 /* Remove the displaced stepping state of process PID. */
1512 remove_displaced_stepping_state (int pid
)
1514 struct displaced_step_inferior_state
*it
, **prev_next_p
;
1516 gdb_assert (pid
!= 0);
1518 it
= displaced_step_inferior_states
;
1519 prev_next_p
= &displaced_step_inferior_states
;
1524 *prev_next_p
= it
->next
;
1529 prev_next_p
= &it
->next
;
1535 infrun_inferior_exit (struct inferior
*inf
)
1537 remove_displaced_stepping_state (inf
->pid
);
1540 /* If ON, and the architecture supports it, GDB will use displaced
1541 stepping to step over breakpoints. If OFF, or if the architecture
1542 doesn't support it, GDB will instead use the traditional
1543 hold-and-step approach. If AUTO (which is the default), GDB will
1544 decide which technique to use to step over breakpoints depending on
1545 which of all-stop or non-stop mode is active --- displaced stepping
1546 in non-stop mode; hold-and-step in all-stop mode. */
1548 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1551 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1552 struct cmd_list_element
*c
,
1555 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1556 fprintf_filtered (file
,
1557 _("Debugger's willingness to use displaced stepping "
1558 "to step over breakpoints is %s (currently %s).\n"),
1559 value
, non_stop
? "on" : "off");
1561 fprintf_filtered (file
,
1562 _("Debugger's willingness to use displaced stepping "
1563 "to step over breakpoints is %s.\n"), value
);
1566 /* Return non-zero if displaced stepping can/should be used to step
1567 over breakpoints. */
1570 use_displaced_stepping (struct gdbarch
*gdbarch
)
1572 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
&& non_stop
)
1573 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1574 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1575 && find_record_target () == NULL
);
1578 /* Clean out any stray displaced stepping state. */
1580 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1582 /* Indicate that there is no cleanup pending. */
1583 displaced
->step_ptid
= null_ptid
;
1585 if (displaced
->step_closure
)
1587 gdbarch_displaced_step_free_closure (displaced
->step_gdbarch
,
1588 displaced
->step_closure
);
1589 displaced
->step_closure
= NULL
;
1594 displaced_step_clear_cleanup (void *arg
)
1596 struct displaced_step_inferior_state
*state
= arg
;
1598 displaced_step_clear (state
);
1601 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1603 displaced_step_dump_bytes (struct ui_file
*file
,
1604 const gdb_byte
*buf
,
1609 for (i
= 0; i
< len
; i
++)
1610 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1611 fputs_unfiltered ("\n", file
);
1614 /* Prepare to single-step, using displaced stepping.
1616 Note that we cannot use displaced stepping when we have a signal to
1617 deliver. If we have a signal to deliver and an instruction to step
1618 over, then after the step, there will be no indication from the
1619 target whether the thread entered a signal handler or ignored the
1620 signal and stepped over the instruction successfully --- both cases
1621 result in a simple SIGTRAP. In the first case we mustn't do a
1622 fixup, and in the second case we must --- but we can't tell which.
1623 Comments in the code for 'random signals' in handle_inferior_event
1624 explain how we handle this case instead.
1626 Returns 1 if preparing was successful -- this thread is going to be
1627 stepped now; or 0 if displaced stepping this thread got queued. */
1629 displaced_step_prepare (ptid_t ptid
)
1631 struct cleanup
*old_cleanups
, *ignore_cleanups
;
1632 struct thread_info
*tp
= find_thread_ptid (ptid
);
1633 struct regcache
*regcache
= get_thread_regcache (ptid
);
1634 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1635 CORE_ADDR original
, copy
;
1637 struct displaced_step_closure
*closure
;
1638 struct displaced_step_inferior_state
*displaced
;
1641 /* We should never reach this function if the architecture does not
1642 support displaced stepping. */
1643 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1645 /* Disable range stepping while executing in the scratch pad. We
1646 want a single-step even if executing the displaced instruction in
1647 the scratch buffer lands within the stepping range (e.g., a
1649 tp
->control
.may_range_step
= 0;
1651 /* We have to displaced step one thread at a time, as we only have
1652 access to a single scratch space per inferior. */
1654 displaced
= add_displaced_stepping_state (ptid_get_pid (ptid
));
1656 if (!ptid_equal (displaced
->step_ptid
, null_ptid
))
1658 /* Already waiting for a displaced step to finish. Defer this
1659 request and place in queue. */
1660 struct displaced_step_request
*req
, *new_req
;
1662 if (debug_displaced
)
1663 fprintf_unfiltered (gdb_stdlog
,
1664 "displaced: defering step of %s\n",
1665 target_pid_to_str (ptid
));
1667 new_req
= xmalloc (sizeof (*new_req
));
1668 new_req
->ptid
= ptid
;
1669 new_req
->next
= NULL
;
1671 if (displaced
->step_request_queue
)
1673 for (req
= displaced
->step_request_queue
;
1677 req
->next
= new_req
;
1680 displaced
->step_request_queue
= new_req
;
1686 if (debug_displaced
)
1687 fprintf_unfiltered (gdb_stdlog
,
1688 "displaced: stepping %s now\n",
1689 target_pid_to_str (ptid
));
1692 displaced_step_clear (displaced
);
1694 old_cleanups
= save_inferior_ptid ();
1695 inferior_ptid
= ptid
;
1697 original
= regcache_read_pc (regcache
);
1699 copy
= gdbarch_displaced_step_location (gdbarch
);
1700 len
= gdbarch_max_insn_length (gdbarch
);
1702 /* Save the original contents of the copy area. */
1703 displaced
->step_saved_copy
= xmalloc (len
);
1704 ignore_cleanups
= make_cleanup (free_current_contents
,
1705 &displaced
->step_saved_copy
);
1706 status
= target_read_memory (copy
, displaced
->step_saved_copy
, len
);
1708 throw_error (MEMORY_ERROR
,
1709 _("Error accessing memory address %s (%s) for "
1710 "displaced-stepping scratch space."),
1711 paddress (gdbarch
, copy
), safe_strerror (status
));
1712 if (debug_displaced
)
1714 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1715 paddress (gdbarch
, copy
));
1716 displaced_step_dump_bytes (gdb_stdlog
,
1717 displaced
->step_saved_copy
,
1721 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1722 original
, copy
, regcache
);
1724 /* We don't support the fully-simulated case at present. */
1725 gdb_assert (closure
);
1727 /* Save the information we need to fix things up if the step
1729 displaced
->step_ptid
= ptid
;
1730 displaced
->step_gdbarch
= gdbarch
;
1731 displaced
->step_closure
= closure
;
1732 displaced
->step_original
= original
;
1733 displaced
->step_copy
= copy
;
1735 make_cleanup (displaced_step_clear_cleanup
, displaced
);
1737 /* Resume execution at the copy. */
1738 regcache_write_pc (regcache
, copy
);
1740 discard_cleanups (ignore_cleanups
);
1742 do_cleanups (old_cleanups
);
1744 if (debug_displaced
)
1745 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1746 paddress (gdbarch
, copy
));
1752 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1753 const gdb_byte
*myaddr
, int len
)
1755 struct cleanup
*ptid_cleanup
= save_inferior_ptid ();
1757 inferior_ptid
= ptid
;
1758 write_memory (memaddr
, myaddr
, len
);
1759 do_cleanups (ptid_cleanup
);
1762 /* Restore the contents of the copy area for thread PTID. */
1765 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1768 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1770 write_memory_ptid (ptid
, displaced
->step_copy
,
1771 displaced
->step_saved_copy
, len
);
1772 if (debug_displaced
)
1773 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1774 target_pid_to_str (ptid
),
1775 paddress (displaced
->step_gdbarch
,
1776 displaced
->step_copy
));
1780 displaced_step_fixup (ptid_t event_ptid
, enum gdb_signal signal
)
1782 struct cleanup
*old_cleanups
;
1783 struct displaced_step_inferior_state
*displaced
1784 = get_displaced_stepping_state (ptid_get_pid (event_ptid
));
1786 /* Was any thread of this process doing a displaced step? */
1787 if (displaced
== NULL
)
1790 /* Was this event for the pid we displaced? */
1791 if (ptid_equal (displaced
->step_ptid
, null_ptid
)
1792 || ! ptid_equal (displaced
->step_ptid
, event_ptid
))
1795 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, displaced
);
1797 displaced_step_restore (displaced
, displaced
->step_ptid
);
1799 /* Did the instruction complete successfully? */
1800 if (signal
== GDB_SIGNAL_TRAP
)
1802 /* Fixup may need to read memory/registers. Switch to the
1803 thread that we're fixing up. */
1804 switch_to_thread (event_ptid
);
1806 /* Fix up the resulting state. */
1807 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1808 displaced
->step_closure
,
1809 displaced
->step_original
,
1810 displaced
->step_copy
,
1811 get_thread_regcache (displaced
->step_ptid
));
1815 /* Since the instruction didn't complete, all we can do is
1817 struct regcache
*regcache
= get_thread_regcache (event_ptid
);
1818 CORE_ADDR pc
= regcache_read_pc (regcache
);
1820 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1821 regcache_write_pc (regcache
, pc
);
1824 do_cleanups (old_cleanups
);
1826 displaced
->step_ptid
= null_ptid
;
1828 /* Are there any pending displaced stepping requests? If so, run
1829 one now. Leave the state object around, since we're likely to
1830 need it again soon. */
1831 while (displaced
->step_request_queue
)
1833 struct displaced_step_request
*head
;
1835 struct regcache
*regcache
;
1836 struct gdbarch
*gdbarch
;
1837 CORE_ADDR actual_pc
;
1838 struct address_space
*aspace
;
1840 head
= displaced
->step_request_queue
;
1842 displaced
->step_request_queue
= head
->next
;
1845 context_switch (ptid
);
1847 regcache
= get_thread_regcache (ptid
);
1848 actual_pc
= regcache_read_pc (regcache
);
1849 aspace
= get_regcache_aspace (regcache
);
1851 if (breakpoint_here_p (aspace
, actual_pc
))
1853 if (debug_displaced
)
1854 fprintf_unfiltered (gdb_stdlog
,
1855 "displaced: stepping queued %s now\n",
1856 target_pid_to_str (ptid
));
1858 displaced_step_prepare (ptid
);
1860 gdbarch
= get_regcache_arch (regcache
);
1862 if (debug_displaced
)
1864 CORE_ADDR actual_pc
= regcache_read_pc (regcache
);
1867 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
1868 paddress (gdbarch
, actual_pc
));
1869 read_memory (actual_pc
, buf
, sizeof (buf
));
1870 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
1873 if (gdbarch_displaced_step_hw_singlestep (gdbarch
,
1874 displaced
->step_closure
))
1875 target_resume (ptid
, 1, GDB_SIGNAL_0
);
1877 target_resume (ptid
, 0, GDB_SIGNAL_0
);
1879 /* Done, we're stepping a thread. */
1885 struct thread_info
*tp
= inferior_thread ();
1887 /* The breakpoint we were sitting under has since been
1889 tp
->control
.trap_expected
= 0;
1891 /* Go back to what we were trying to do. */
1892 step
= currently_stepping (tp
);
1894 if (debug_displaced
)
1895 fprintf_unfiltered (gdb_stdlog
,
1896 "displaced: breakpoint is gone: %s, step(%d)\n",
1897 target_pid_to_str (tp
->ptid
), step
);
1899 target_resume (ptid
, step
, GDB_SIGNAL_0
);
1900 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1902 /* This request was discarded. See if there's any other
1903 thread waiting for its turn. */
1908 /* Update global variables holding ptids to hold NEW_PTID if they were
1909 holding OLD_PTID. */
1911 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
1913 struct displaced_step_request
*it
;
1914 struct displaced_step_inferior_state
*displaced
;
1916 if (ptid_equal (inferior_ptid
, old_ptid
))
1917 inferior_ptid
= new_ptid
;
1919 for (displaced
= displaced_step_inferior_states
;
1921 displaced
= displaced
->next
)
1923 if (ptid_equal (displaced
->step_ptid
, old_ptid
))
1924 displaced
->step_ptid
= new_ptid
;
1926 for (it
= displaced
->step_request_queue
; it
; it
= it
->next
)
1927 if (ptid_equal (it
->ptid
, old_ptid
))
1928 it
->ptid
= new_ptid
;
1935 /* Things to clean up if we QUIT out of resume (). */
1937 resume_cleanups (void *ignore
)
1939 if (!ptid_equal (inferior_ptid
, null_ptid
))
1940 delete_single_step_breakpoints (inferior_thread ());
1945 static const char schedlock_off
[] = "off";
1946 static const char schedlock_on
[] = "on";
1947 static const char schedlock_step
[] = "step";
1948 static const char *const scheduler_enums
[] = {
1954 static const char *scheduler_mode
= schedlock_off
;
1956 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
1957 struct cmd_list_element
*c
, const char *value
)
1959 fprintf_filtered (file
,
1960 _("Mode for locking scheduler "
1961 "during execution is \"%s\".\n"),
1966 set_schedlock_func (char *args
, int from_tty
, struct cmd_list_element
*c
)
1968 if (!target_can_lock_scheduler
)
1970 scheduler_mode
= schedlock_off
;
1971 error (_("Target '%s' cannot support this command."), target_shortname
);
1975 /* True if execution commands resume all threads of all processes by
1976 default; otherwise, resume only threads of the current inferior
1978 int sched_multi
= 0;
1980 /* Try to setup for software single stepping over the specified location.
1981 Return 1 if target_resume() should use hardware single step.
1983 GDBARCH the current gdbarch.
1984 PC the location to step over. */
1987 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
1991 if (execution_direction
== EXEC_FORWARD
1992 && gdbarch_software_single_step_p (gdbarch
)
1993 && gdbarch_software_single_step (gdbarch
, get_current_frame ()))
2001 user_visible_resume_ptid (int step
)
2003 /* By default, resume all threads of all processes. */
2004 ptid_t resume_ptid
= RESUME_ALL
;
2006 /* Maybe resume only all threads of the current process. */
2007 if (!sched_multi
&& target_supports_multi_process ())
2009 resume_ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
2012 /* Maybe resume a single thread after all. */
2015 /* With non-stop mode on, threads are always handled
2017 resume_ptid
= inferior_ptid
;
2019 else if ((scheduler_mode
== schedlock_on
)
2020 || (scheduler_mode
== schedlock_step
&& step
))
2022 /* User-settable 'scheduler' mode requires solo thread resume. */
2023 resume_ptid
= inferior_ptid
;
2026 /* We may actually resume fewer threads at first, e.g., if a thread
2027 is stopped at a breakpoint that needs stepping-off, but that
2028 should not be visible to the user/frontend, and neither should
2029 the frontend/user be allowed to proceed any of the threads that
2030 happen to be stopped for internal run control handling, if a
2031 previous command wanted them resumed. */
2035 /* Resume the inferior, but allow a QUIT. This is useful if the user
2036 wants to interrupt some lengthy single-stepping operation
2037 (for child processes, the SIGINT goes to the inferior, and so
2038 we get a SIGINT random_signal, but for remote debugging and perhaps
2039 other targets, that's not true).
2041 STEP nonzero if we should step (zero to continue instead).
2042 SIG is the signal to give the inferior (zero for none). */
2044 resume (int step
, enum gdb_signal sig
)
2046 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
2047 struct regcache
*regcache
= get_current_regcache ();
2048 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2049 struct thread_info
*tp
= inferior_thread ();
2050 CORE_ADDR pc
= regcache_read_pc (regcache
);
2051 struct address_space
*aspace
= get_regcache_aspace (regcache
);
2053 /* From here on, this represents the caller's step vs continue
2054 request, while STEP represents what we'll actually request the
2055 target to do. STEP can decay from a step to a continue, if e.g.,
2056 we need to implement single-stepping with breakpoints (software
2057 single-step). When deciding whether "set scheduler-locking step"
2058 applies, it's the callers intention that counts. */
2059 const int entry_step
= step
;
2061 tp
->stepped_breakpoint
= 0;
2065 if (current_inferior ()->waiting_for_vfork_done
)
2067 /* Don't try to single-step a vfork parent that is waiting for
2068 the child to get out of the shared memory region (by exec'ing
2069 or exiting). This is particularly important on software
2070 single-step archs, as the child process would trip on the
2071 software single step breakpoint inserted for the parent
2072 process. Since the parent will not actually execute any
2073 instruction until the child is out of the shared region (such
2074 are vfork's semantics), it is safe to simply continue it.
2075 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2076 the parent, and tell it to `keep_going', which automatically
2077 re-sets it stepping. */
2079 fprintf_unfiltered (gdb_stdlog
,
2080 "infrun: resume : clear step\n");
2085 fprintf_unfiltered (gdb_stdlog
,
2086 "infrun: resume (step=%d, signal=%s), "
2087 "trap_expected=%d, current thread [%s] at %s\n",
2088 step
, gdb_signal_to_symbol_string (sig
),
2089 tp
->control
.trap_expected
,
2090 target_pid_to_str (inferior_ptid
),
2091 paddress (gdbarch
, pc
));
2093 /* Normally, by the time we reach `resume', the breakpoints are either
2094 removed or inserted, as appropriate. The exception is if we're sitting
2095 at a permanent breakpoint; we need to step over it, but permanent
2096 breakpoints can't be removed. So we have to test for it here. */
2097 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2099 if (sig
!= GDB_SIGNAL_0
)
2101 /* We have a signal to pass to the inferior. The resume
2102 may, or may not take us to the signal handler. If this
2103 is a step, we'll need to stop in the signal handler, if
2104 there's one, (if the target supports stepping into
2105 handlers), or in the next mainline instruction, if
2106 there's no handler. If this is a continue, we need to be
2107 sure to run the handler with all breakpoints inserted.
2108 In all cases, set a breakpoint at the current address
2109 (where the handler returns to), and once that breakpoint
2110 is hit, resume skipping the permanent breakpoint. If
2111 that breakpoint isn't hit, then we've stepped into the
2112 signal handler (or hit some other event). We'll delete
2113 the step-resume breakpoint then. */
2116 fprintf_unfiltered (gdb_stdlog
,
2117 "infrun: resume: skipping permanent breakpoint, "
2118 "deliver signal first\n");
2120 clear_step_over_info ();
2121 tp
->control
.trap_expected
= 0;
2123 if (tp
->control
.step_resume_breakpoint
== NULL
)
2125 /* Set a "high-priority" step-resume, as we don't want
2126 user breakpoints at PC to trigger (again) when this
2128 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2129 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2131 tp
->step_after_step_resume_breakpoint
= step
;
2134 insert_breakpoints ();
2138 /* There's no signal to pass, we can go ahead and skip the
2139 permanent breakpoint manually. */
2141 fprintf_unfiltered (gdb_stdlog
,
2142 "infrun: resume: skipping permanent breakpoint\n");
2143 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2144 /* Update pc to reflect the new address from which we will
2145 execute instructions. */
2146 pc
= regcache_read_pc (regcache
);
2150 /* We've already advanced the PC, so the stepping part
2151 is done. Now we need to arrange for a trap to be
2152 reported to handle_inferior_event. Set a breakpoint
2153 at the current PC, and run to it. Don't update
2154 prev_pc, because if we end in
2155 switch_back_to_stepping, we want the "expected thread
2156 advanced also" branch to be taken. IOW, we don't
2157 want this thread to step further from PC
2159 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2160 insert_breakpoints ();
2162 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2163 /* We're continuing with all breakpoints inserted. It's
2164 safe to let the target bypass signals. */
2165 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
2166 /* ... and safe to let other threads run, according to
2168 resume_ptid
= user_visible_resume_ptid (entry_step
);
2169 target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2170 discard_cleanups (old_cleanups
);
2176 /* If we have a breakpoint to step over, make sure to do a single
2177 step only. Same if we have software watchpoints. */
2178 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2179 tp
->control
.may_range_step
= 0;
2181 /* If enabled, step over breakpoints by executing a copy of the
2182 instruction at a different address.
2184 We can't use displaced stepping when we have a signal to deliver;
2185 the comments for displaced_step_prepare explain why. The
2186 comments in the handle_inferior event for dealing with 'random
2187 signals' explain what we do instead.
2189 We can't use displaced stepping when we are waiting for vfork_done
2190 event, displaced stepping breaks the vfork child similarly as single
2191 step software breakpoint. */
2192 if (use_displaced_stepping (gdbarch
)
2193 && tp
->control
.trap_expected
2194 && sig
== GDB_SIGNAL_0
2195 && !current_inferior ()->waiting_for_vfork_done
)
2197 struct displaced_step_inferior_state
*displaced
;
2199 if (!displaced_step_prepare (inferior_ptid
))
2201 /* Got placed in displaced stepping queue. Will be resumed
2202 later when all the currently queued displaced stepping
2203 requests finish. The thread is not executing at this
2204 point, and the call to set_executing will be made later.
2205 But we need to call set_running here, since from the
2206 user/frontend's point of view, threads were set running.
2207 Unless we're calling an inferior function, as in that
2208 case we pretend the inferior doesn't run at all. */
2209 if (!tp
->control
.in_infcall
)
2210 set_running (user_visible_resume_ptid (entry_step
), 1);
2211 discard_cleanups (old_cleanups
);
2215 /* Update pc to reflect the new address from which we will execute
2216 instructions due to displaced stepping. */
2217 pc
= regcache_read_pc (get_thread_regcache (inferior_ptid
));
2219 displaced
= get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
2220 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2221 displaced
->step_closure
);
2224 /* Do we need to do it the hard way, w/temp breakpoints? */
2226 step
= maybe_software_singlestep (gdbarch
, pc
);
2228 /* Currently, our software single-step implementation leads to different
2229 results than hardware single-stepping in one situation: when stepping
2230 into delivering a signal which has an associated signal handler,
2231 hardware single-step will stop at the first instruction of the handler,
2232 while software single-step will simply skip execution of the handler.
2234 For now, this difference in behavior is accepted since there is no
2235 easy way to actually implement single-stepping into a signal handler
2236 without kernel support.
2238 However, there is one scenario where this difference leads to follow-on
2239 problems: if we're stepping off a breakpoint by removing all breakpoints
2240 and then single-stepping. In this case, the software single-step
2241 behavior means that even if there is a *breakpoint* in the signal
2242 handler, GDB still would not stop.
2244 Fortunately, we can at least fix this particular issue. We detect
2245 here the case where we are about to deliver a signal while software
2246 single-stepping with breakpoints removed. In this situation, we
2247 revert the decisions to remove all breakpoints and insert single-
2248 step breakpoints, and instead we install a step-resume breakpoint
2249 at the current address, deliver the signal without stepping, and
2250 once we arrive back at the step-resume breakpoint, actually step
2251 over the breakpoint we originally wanted to step over. */
2252 if (thread_has_single_step_breakpoints_set (tp
)
2253 && sig
!= GDB_SIGNAL_0
2254 && step_over_info_valid_p ())
2256 /* If we have nested signals or a pending signal is delivered
2257 immediately after a handler returns, might might already have
2258 a step-resume breakpoint set on the earlier handler. We cannot
2259 set another step-resume breakpoint; just continue on until the
2260 original breakpoint is hit. */
2261 if (tp
->control
.step_resume_breakpoint
== NULL
)
2263 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2264 tp
->step_after_step_resume_breakpoint
= 1;
2267 delete_single_step_breakpoints (tp
);
2269 clear_step_over_info ();
2270 tp
->control
.trap_expected
= 0;
2272 insert_breakpoints ();
2275 /* If STEP is set, it's a request to use hardware stepping
2276 facilities. But in that case, we should never
2277 use singlestep breakpoint. */
2278 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2280 /* Decide the set of threads to ask the target to resume. Start
2281 by assuming everything will be resumed, than narrow the set
2282 by applying increasingly restricting conditions. */
2283 resume_ptid
= user_visible_resume_ptid (entry_step
);
2285 /* Even if RESUME_PTID is a wildcard, and we end up resuming less
2286 (e.g., we might need to step over a breakpoint), from the
2287 user/frontend's point of view, all threads in RESUME_PTID are now
2288 running. Unless we're calling an inferior function, as in that
2289 case pretend we inferior doesn't run at all. */
2290 if (!tp
->control
.in_infcall
)
2291 set_running (resume_ptid
, 1);
2293 /* Maybe resume a single thread after all. */
2294 if ((step
|| thread_has_single_step_breakpoints_set (tp
))
2295 && tp
->control
.trap_expected
)
2297 /* We're allowing a thread to run past a breakpoint it has
2298 hit, by single-stepping the thread with the breakpoint
2299 removed. In which case, we need to single-step only this
2300 thread, and keep others stopped, as they can miss this
2301 breakpoint if allowed to run. */
2302 resume_ptid
= inferior_ptid
;
2305 if (execution_direction
!= EXEC_REVERSE
2306 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2308 /* The only case we currently need to step a breakpoint
2309 instruction is when we have a signal to deliver. See
2310 handle_signal_stop where we handle random signals that could
2311 take out us out of the stepping range. Normally, in that
2312 case we end up continuing (instead of stepping) over the
2313 signal handler with a breakpoint at PC, but there are cases
2314 where we should _always_ single-step, even if we have a
2315 step-resume breakpoint, like when a software watchpoint is
2316 set. Assuming single-stepping and delivering a signal at the
2317 same time would takes us to the signal handler, then we could
2318 have removed the breakpoint at PC to step over it. However,
2319 some hardware step targets (like e.g., Mac OS) can't step
2320 into signal handlers, and for those, we need to leave the
2321 breakpoint at PC inserted, as otherwise if the handler
2322 recurses and executes PC again, it'll miss the breakpoint.
2323 So we leave the breakpoint inserted anyway, but we need to
2324 record that we tried to step a breakpoint instruction, so
2325 that adjust_pc_after_break doesn't end up confused. */
2326 gdb_assert (sig
!= GDB_SIGNAL_0
);
2328 tp
->stepped_breakpoint
= 1;
2330 /* Most targets can step a breakpoint instruction, thus
2331 executing it normally. But if this one cannot, just
2332 continue and we will hit it anyway. */
2333 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2338 && use_displaced_stepping (gdbarch
)
2339 && tp
->control
.trap_expected
)
2341 struct regcache
*resume_regcache
= get_thread_regcache (resume_ptid
);
2342 struct gdbarch
*resume_gdbarch
= get_regcache_arch (resume_regcache
);
2343 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2346 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2347 paddress (resume_gdbarch
, actual_pc
));
2348 read_memory (actual_pc
, buf
, sizeof (buf
));
2349 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2352 if (tp
->control
.may_range_step
)
2354 /* If we're resuming a thread with the PC out of the step
2355 range, then we're doing some nested/finer run control
2356 operation, like stepping the thread out of the dynamic
2357 linker or the displaced stepping scratch pad. We
2358 shouldn't have allowed a range step then. */
2359 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2362 /* Install inferior's terminal modes. */
2363 target_terminal_inferior ();
2365 /* Avoid confusing the next resume, if the next stop/resume
2366 happens to apply to another thread. */
2367 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2369 /* Advise target which signals may be handled silently. If we have
2370 removed breakpoints because we are stepping over one (in any
2371 thread), we need to receive all signals to avoid accidentally
2372 skipping a breakpoint during execution of a signal handler. */
2373 if (step_over_info_valid_p ())
2374 target_pass_signals (0, NULL
);
2376 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
2378 target_resume (resume_ptid
, step
, sig
);
2380 discard_cleanups (old_cleanups
);
2385 /* Clear out all variables saying what to do when inferior is continued.
2386 First do this, then set the ones you want, then call `proceed'. */
2389 clear_proceed_status_thread (struct thread_info
*tp
)
2392 fprintf_unfiltered (gdb_stdlog
,
2393 "infrun: clear_proceed_status_thread (%s)\n",
2394 target_pid_to_str (tp
->ptid
));
2396 /* If this signal should not be seen by program, give it zero.
2397 Used for debugging signals. */
2398 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2399 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2401 tp
->control
.trap_expected
= 0;
2402 tp
->control
.step_range_start
= 0;
2403 tp
->control
.step_range_end
= 0;
2404 tp
->control
.may_range_step
= 0;
2405 tp
->control
.step_frame_id
= null_frame_id
;
2406 tp
->control
.step_stack_frame_id
= null_frame_id
;
2407 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2408 tp
->control
.step_start_function
= NULL
;
2409 tp
->stop_requested
= 0;
2411 tp
->control
.stop_step
= 0;
2413 tp
->control
.proceed_to_finish
= 0;
2415 tp
->control
.command_interp
= NULL
;
2417 /* Discard any remaining commands or status from previous stop. */
2418 bpstat_clear (&tp
->control
.stop_bpstat
);
2422 clear_proceed_status (int step
)
2426 struct thread_info
*tp
;
2429 resume_ptid
= user_visible_resume_ptid (step
);
2431 /* In all-stop mode, delete the per-thread status of all threads
2432 we're about to resume, implicitly and explicitly. */
2433 ALL_NON_EXITED_THREADS (tp
)
2435 if (!ptid_match (tp
->ptid
, resume_ptid
))
2437 clear_proceed_status_thread (tp
);
2441 if (!ptid_equal (inferior_ptid
, null_ptid
))
2443 struct inferior
*inferior
;
2447 /* If in non-stop mode, only delete the per-thread status of
2448 the current thread. */
2449 clear_proceed_status_thread (inferior_thread ());
2452 inferior
= current_inferior ();
2453 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2456 stop_after_trap
= 0;
2458 clear_step_over_info ();
2460 observer_notify_about_to_proceed ();
2464 regcache_xfree (stop_registers
);
2465 stop_registers
= NULL
;
2469 /* Returns true if TP is still stopped at a breakpoint that needs
2470 stepping-over in order to make progress. If the breakpoint is gone
2471 meanwhile, we can skip the whole step-over dance. */
2474 thread_still_needs_step_over (struct thread_info
*tp
)
2476 if (tp
->stepping_over_breakpoint
)
2478 struct regcache
*regcache
= get_thread_regcache (tp
->ptid
);
2480 if (breakpoint_here_p (get_regcache_aspace (regcache
),
2481 regcache_read_pc (regcache
))
2482 == ordinary_breakpoint_here
)
2485 tp
->stepping_over_breakpoint
= 0;
2491 /* Returns true if scheduler locking applies. STEP indicates whether
2492 we're about to do a step/next-like command to a thread. */
2495 schedlock_applies (int step
)
2497 return (scheduler_mode
== schedlock_on
2498 || (scheduler_mode
== schedlock_step
2502 /* Look a thread other than EXCEPT that has previously reported a
2503 breakpoint event, and thus needs a step-over in order to make
2504 progress. Returns NULL is none is found. STEP indicates whether
2505 we're about to step the current thread, in order to decide whether
2506 "set scheduler-locking step" applies. */
2508 static struct thread_info
*
2509 find_thread_needs_step_over (int step
, struct thread_info
*except
)
2511 struct thread_info
*tp
, *current
;
2513 /* With non-stop mode on, threads are always handled individually. */
2514 gdb_assert (! non_stop
);
2516 current
= inferior_thread ();
2518 /* If scheduler locking applies, we can avoid iterating over all
2520 if (schedlock_applies (step
))
2522 if (except
!= current
2523 && thread_still_needs_step_over (current
))
2529 ALL_NON_EXITED_THREADS (tp
)
2531 /* Ignore the EXCEPT thread. */
2534 /* Ignore threads of processes we're not resuming. */
2536 && ptid_get_pid (tp
->ptid
) != ptid_get_pid (inferior_ptid
))
2539 if (thread_still_needs_step_over (tp
))
2546 /* Basic routine for continuing the program in various fashions.
2548 ADDR is the address to resume at, or -1 for resume where stopped.
2549 SIGGNAL is the signal to give it, or 0 for none,
2550 or -1 for act according to how it stopped.
2551 STEP is nonzero if should trap after one instruction.
2552 -1 means return after that and print nothing.
2553 You should probably set various step_... variables
2554 before calling here, if you are stepping.
2556 You should call clear_proceed_status before calling proceed. */
2559 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
, int step
)
2561 struct regcache
*regcache
;
2562 struct gdbarch
*gdbarch
;
2563 struct thread_info
*tp
;
2565 struct address_space
*aspace
;
2567 /* If we're stopped at a fork/vfork, follow the branch set by the
2568 "set follow-fork-mode" command; otherwise, we'll just proceed
2569 resuming the current thread. */
2570 if (!follow_fork ())
2572 /* The target for some reason decided not to resume. */
2574 if (target_can_async_p ())
2575 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2579 /* We'll update this if & when we switch to a new thread. */
2580 previous_inferior_ptid
= inferior_ptid
;
2582 regcache
= get_current_regcache ();
2583 gdbarch
= get_regcache_arch (regcache
);
2584 aspace
= get_regcache_aspace (regcache
);
2585 pc
= regcache_read_pc (regcache
);
2586 tp
= inferior_thread ();
2589 tp
->control
.step_start_function
= find_pc_function (pc
);
2591 /* Fill in with reasonable starting values. */
2592 init_thread_stepping_state (tp
);
2594 if (addr
== (CORE_ADDR
) -1)
2597 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2598 && execution_direction
!= EXEC_REVERSE
)
2599 /* There is a breakpoint at the address we will resume at,
2600 step one instruction before inserting breakpoints so that
2601 we do not stop right away (and report a second hit at this
2604 Note, we don't do this in reverse, because we won't
2605 actually be executing the breakpoint insn anyway.
2606 We'll be (un-)executing the previous instruction. */
2607 tp
->stepping_over_breakpoint
= 1;
2608 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2609 && gdbarch_single_step_through_delay (gdbarch
,
2610 get_current_frame ()))
2611 /* We stepped onto an instruction that needs to be stepped
2612 again before re-inserting the breakpoint, do so. */
2613 tp
->stepping_over_breakpoint
= 1;
2617 regcache_write_pc (regcache
, addr
);
2620 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2621 tp
->suspend
.stop_signal
= siggnal
;
2623 /* Record the interpreter that issued the execution command that
2624 caused this thread to resume. If the top level interpreter is
2625 MI/async, and the execution command was a CLI command
2626 (next/step/etc.), we'll want to print stop event output to the MI
2627 console channel (the stepped-to line, etc.), as if the user
2628 entered the execution command on a real GDB console. */
2629 inferior_thread ()->control
.command_interp
= command_interp ();
2632 fprintf_unfiltered (gdb_stdlog
,
2633 "infrun: proceed (addr=%s, signal=%s, step=%d)\n",
2634 paddress (gdbarch
, addr
),
2635 gdb_signal_to_symbol_string (siggnal
), step
);
2638 /* In non-stop, each thread is handled individually. The context
2639 must already be set to the right thread here. */
2643 struct thread_info
*step_over
;
2645 /* In a multi-threaded task we may select another thread and
2646 then continue or step.
2648 But if the old thread was stopped at a breakpoint, it will
2649 immediately cause another breakpoint stop without any
2650 execution (i.e. it will report a breakpoint hit incorrectly).
2651 So we must step over it first.
2653 Look for a thread other than the current (TP) that reported a
2654 breakpoint hit and hasn't been resumed yet since. */
2655 step_over
= find_thread_needs_step_over (step
, tp
);
2656 if (step_over
!= NULL
)
2659 fprintf_unfiltered (gdb_stdlog
,
2660 "infrun: need to step-over [%s] first\n",
2661 target_pid_to_str (step_over
->ptid
));
2663 /* Store the prev_pc for the stepping thread too, needed by
2664 switch_back_to_stepping thread. */
2665 tp
->prev_pc
= regcache_read_pc (get_current_regcache ());
2666 switch_to_thread (step_over
->ptid
);
2671 /* If we need to step over a breakpoint, and we're not using
2672 displaced stepping to do so, insert all breakpoints (watchpoints,
2673 etc.) but the one we're stepping over, step one instruction, and
2674 then re-insert the breakpoint when that step is finished. */
2675 if (tp
->stepping_over_breakpoint
&& !use_displaced_stepping (gdbarch
))
2677 struct regcache
*regcache
= get_current_regcache ();
2679 set_step_over_info (get_regcache_aspace (regcache
),
2680 regcache_read_pc (regcache
), 0);
2683 clear_step_over_info ();
2685 insert_breakpoints ();
2687 tp
->control
.trap_expected
= tp
->stepping_over_breakpoint
;
2689 annotate_starting ();
2691 /* Make sure that output from GDB appears before output from the
2693 gdb_flush (gdb_stdout
);
2695 /* Refresh prev_pc value just prior to resuming. This used to be
2696 done in stop_waiting, however, setting prev_pc there did not handle
2697 scenarios such as inferior function calls or returning from
2698 a function via the return command. In those cases, the prev_pc
2699 value was not set properly for subsequent commands. The prev_pc value
2700 is used to initialize the starting line number in the ecs. With an
2701 invalid value, the gdb next command ends up stopping at the position
2702 represented by the next line table entry past our start position.
2703 On platforms that generate one line table entry per line, this
2704 is not a problem. However, on the ia64, the compiler generates
2705 extraneous line table entries that do not increase the line number.
2706 When we issue the gdb next command on the ia64 after an inferior call
2707 or a return command, we often end up a few instructions forward, still
2708 within the original line we started.
2710 An attempt was made to refresh the prev_pc at the same time the
2711 execution_control_state is initialized (for instance, just before
2712 waiting for an inferior event). But this approach did not work
2713 because of platforms that use ptrace, where the pc register cannot
2714 be read unless the inferior is stopped. At that point, we are not
2715 guaranteed the inferior is stopped and so the regcache_read_pc() call
2716 can fail. Setting the prev_pc value here ensures the value is updated
2717 correctly when the inferior is stopped. */
2718 tp
->prev_pc
= regcache_read_pc (get_current_regcache ());
2720 /* Resume inferior. */
2721 resume (tp
->control
.trap_expected
|| step
|| bpstat_should_step (),
2722 tp
->suspend
.stop_signal
);
2724 /* Wait for it to stop (if not standalone)
2725 and in any case decode why it stopped, and act accordingly. */
2726 /* Do this only if we are not using the event loop, or if the target
2727 does not support asynchronous execution. */
2728 if (!target_can_async_p ())
2730 wait_for_inferior ();
2736 /* Start remote-debugging of a machine over a serial link. */
2739 start_remote (int from_tty
)
2741 struct inferior
*inferior
;
2743 inferior
= current_inferior ();
2744 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
2746 /* Always go on waiting for the target, regardless of the mode. */
2747 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2748 indicate to wait_for_inferior that a target should timeout if
2749 nothing is returned (instead of just blocking). Because of this,
2750 targets expecting an immediate response need to, internally, set
2751 things up so that the target_wait() is forced to eventually
2753 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2754 differentiate to its caller what the state of the target is after
2755 the initial open has been performed. Here we're assuming that
2756 the target has stopped. It should be possible to eventually have
2757 target_open() return to the caller an indication that the target
2758 is currently running and GDB state should be set to the same as
2759 for an async run. */
2760 wait_for_inferior ();
2762 /* Now that the inferior has stopped, do any bookkeeping like
2763 loading shared libraries. We want to do this before normal_stop,
2764 so that the displayed frame is up to date. */
2765 post_create_inferior (¤t_target
, from_tty
);
2770 /* Initialize static vars when a new inferior begins. */
2773 init_wait_for_inferior (void)
2775 /* These are meaningless until the first time through wait_for_inferior. */
2777 breakpoint_init_inferior (inf_starting
);
2779 clear_proceed_status (0);
2781 target_last_wait_ptid
= minus_one_ptid
;
2783 previous_inferior_ptid
= inferior_ptid
;
2785 /* Discard any skipped inlined frames. */
2786 clear_inline_frame_state (minus_one_ptid
);
2790 /* Data to be passed around while handling an event. This data is
2791 discarded between events. */
2792 struct execution_control_state
2795 /* The thread that got the event, if this was a thread event; NULL
2797 struct thread_info
*event_thread
;
2799 struct target_waitstatus ws
;
2800 int stop_func_filled_in
;
2801 CORE_ADDR stop_func_start
;
2802 CORE_ADDR stop_func_end
;
2803 const char *stop_func_name
;
2806 /* True if the event thread hit the single-step breakpoint of
2807 another thread. Thus the event doesn't cause a stop, the thread
2808 needs to be single-stepped past the single-step breakpoint before
2809 we can switch back to the original stepping thread. */
2810 int hit_singlestep_breakpoint
;
2813 static void handle_inferior_event (struct execution_control_state
*ecs
);
2815 static void handle_step_into_function (struct gdbarch
*gdbarch
,
2816 struct execution_control_state
*ecs
);
2817 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
2818 struct execution_control_state
*ecs
);
2819 static void handle_signal_stop (struct execution_control_state
*ecs
);
2820 static void check_exception_resume (struct execution_control_state
*,
2821 struct frame_info
*);
2823 static void end_stepping_range (struct execution_control_state
*ecs
);
2824 static void stop_waiting (struct execution_control_state
*ecs
);
2825 static void prepare_to_wait (struct execution_control_state
*ecs
);
2826 static void keep_going (struct execution_control_state
*ecs
);
2827 static void process_event_stop_test (struct execution_control_state
*ecs
);
2828 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
2830 /* Callback for iterate over threads. If the thread is stopped, but
2831 the user/frontend doesn't know about that yet, go through
2832 normal_stop, as if the thread had just stopped now. ARG points at
2833 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2834 ptid_is_pid(PTID) is true, applies to all threads of the process
2835 pointed at by PTID. Otherwise, apply only to the thread pointed by
2839 infrun_thread_stop_requested_callback (struct thread_info
*info
, void *arg
)
2841 ptid_t ptid
= * (ptid_t
*) arg
;
2843 if ((ptid_equal (info
->ptid
, ptid
)
2844 || ptid_equal (minus_one_ptid
, ptid
)
2845 || (ptid_is_pid (ptid
)
2846 && ptid_get_pid (ptid
) == ptid_get_pid (info
->ptid
)))
2847 && is_running (info
->ptid
)
2848 && !is_executing (info
->ptid
))
2850 struct cleanup
*old_chain
;
2851 struct execution_control_state ecss
;
2852 struct execution_control_state
*ecs
= &ecss
;
2854 memset (ecs
, 0, sizeof (*ecs
));
2856 old_chain
= make_cleanup_restore_current_thread ();
2858 overlay_cache_invalid
= 1;
2859 /* Flush target cache before starting to handle each event.
2860 Target was running and cache could be stale. This is just a
2861 heuristic. Running threads may modify target memory, but we
2862 don't get any event. */
2863 target_dcache_invalidate ();
2865 /* Go through handle_inferior_event/normal_stop, so we always
2866 have consistent output as if the stop event had been
2868 ecs
->ptid
= info
->ptid
;
2869 ecs
->event_thread
= find_thread_ptid (info
->ptid
);
2870 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
2871 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
2873 handle_inferior_event (ecs
);
2875 if (!ecs
->wait_some_more
)
2877 struct thread_info
*tp
;
2881 /* Finish off the continuations. */
2882 tp
= inferior_thread ();
2883 do_all_intermediate_continuations_thread (tp
, 1);
2884 do_all_continuations_thread (tp
, 1);
2887 do_cleanups (old_chain
);
2893 /* This function is attached as a "thread_stop_requested" observer.
2894 Cleanup local state that assumed the PTID was to be resumed, and
2895 report the stop to the frontend. */
2898 infrun_thread_stop_requested (ptid_t ptid
)
2900 struct displaced_step_inferior_state
*displaced
;
2902 /* PTID was requested to stop. Remove it from the displaced
2903 stepping queue, so we don't try to resume it automatically. */
2905 for (displaced
= displaced_step_inferior_states
;
2907 displaced
= displaced
->next
)
2909 struct displaced_step_request
*it
, **prev_next_p
;
2911 it
= displaced
->step_request_queue
;
2912 prev_next_p
= &displaced
->step_request_queue
;
2915 if (ptid_match (it
->ptid
, ptid
))
2917 *prev_next_p
= it
->next
;
2923 prev_next_p
= &it
->next
;
2930 iterate_over_threads (infrun_thread_stop_requested_callback
, &ptid
);
2934 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
2936 if (ptid_equal (target_last_wait_ptid
, tp
->ptid
))
2937 nullify_last_target_wait_ptid ();
2940 /* Delete the step resume, single-step and longjmp/exception resume
2941 breakpoints of TP. */
2944 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
2946 delete_step_resume_breakpoint (tp
);
2947 delete_exception_resume_breakpoint (tp
);
2948 delete_single_step_breakpoints (tp
);
2951 /* If the target still has execution, call FUNC for each thread that
2952 just stopped. In all-stop, that's all the non-exited threads; in
2953 non-stop, that's the current thread, only. */
2955 typedef void (*for_each_just_stopped_thread_callback_func
)
2956 (struct thread_info
*tp
);
2959 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
2961 if (!target_has_execution
|| ptid_equal (inferior_ptid
, null_ptid
))
2966 /* If in non-stop mode, only the current thread stopped. */
2967 func (inferior_thread ());
2971 struct thread_info
*tp
;
2973 /* In all-stop mode, all threads have stopped. */
2974 ALL_NON_EXITED_THREADS (tp
)
2981 /* Delete the step resume and longjmp/exception resume breakpoints of
2982 the threads that just stopped. */
2985 delete_just_stopped_threads_infrun_breakpoints (void)
2987 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
2990 /* Delete the single-step breakpoints of the threads that just
2994 delete_just_stopped_threads_single_step_breakpoints (void)
2996 for_each_just_stopped_thread (delete_single_step_breakpoints
);
2999 /* A cleanup wrapper. */
3002 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg
)
3004 delete_just_stopped_threads_infrun_breakpoints ();
3007 /* Pretty print the results of target_wait, for debugging purposes. */
3010 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3011 const struct target_waitstatus
*ws
)
3013 char *status_string
= target_waitstatus_to_string (ws
);
3014 struct ui_file
*tmp_stream
= mem_fileopen ();
3017 /* The text is split over several lines because it was getting too long.
3018 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3019 output as a unit; we want only one timestamp printed if debug_timestamp
3022 fprintf_unfiltered (tmp_stream
,
3023 "infrun: target_wait (%d", ptid_get_pid (waiton_ptid
));
3024 if (ptid_get_pid (waiton_ptid
) != -1)
3025 fprintf_unfiltered (tmp_stream
,
3026 " [%s]", target_pid_to_str (waiton_ptid
));
3027 fprintf_unfiltered (tmp_stream
, ", status) =\n");
3028 fprintf_unfiltered (tmp_stream
,
3029 "infrun: %d [%s],\n",
3030 ptid_get_pid (result_ptid
),
3031 target_pid_to_str (result_ptid
));
3032 fprintf_unfiltered (tmp_stream
,
3036 text
= ui_file_xstrdup (tmp_stream
, NULL
);
3038 /* This uses %s in part to handle %'s in the text, but also to avoid
3039 a gcc error: the format attribute requires a string literal. */
3040 fprintf_unfiltered (gdb_stdlog
, "%s", text
);
3042 xfree (status_string
);
3044 ui_file_delete (tmp_stream
);
3047 /* Prepare and stabilize the inferior for detaching it. E.g.,
3048 detaching while a thread is displaced stepping is a recipe for
3049 crashing it, as nothing would readjust the PC out of the scratch
3053 prepare_for_detach (void)
3055 struct inferior
*inf
= current_inferior ();
3056 ptid_t pid_ptid
= pid_to_ptid (inf
->pid
);
3057 struct cleanup
*old_chain_1
;
3058 struct displaced_step_inferior_state
*displaced
;
3060 displaced
= get_displaced_stepping_state (inf
->pid
);
3062 /* Is any thread of this process displaced stepping? If not,
3063 there's nothing else to do. */
3064 if (displaced
== NULL
|| ptid_equal (displaced
->step_ptid
, null_ptid
))
3068 fprintf_unfiltered (gdb_stdlog
,
3069 "displaced-stepping in-process while detaching");
3071 old_chain_1
= make_cleanup_restore_integer (&inf
->detaching
);
3074 while (!ptid_equal (displaced
->step_ptid
, null_ptid
))
3076 struct cleanup
*old_chain_2
;
3077 struct execution_control_state ecss
;
3078 struct execution_control_state
*ecs
;
3081 memset (ecs
, 0, sizeof (*ecs
));
3083 overlay_cache_invalid
= 1;
3084 /* Flush target cache before starting to handle each event.
3085 Target was running and cache could be stale. This is just a
3086 heuristic. Running threads may modify target memory, but we
3087 don't get any event. */
3088 target_dcache_invalidate ();
3090 if (deprecated_target_wait_hook
)
3091 ecs
->ptid
= deprecated_target_wait_hook (pid_ptid
, &ecs
->ws
, 0);
3093 ecs
->ptid
= target_wait (pid_ptid
, &ecs
->ws
, 0);
3096 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3098 /* If an error happens while handling the event, propagate GDB's
3099 knowledge of the executing state to the frontend/user running
3101 old_chain_2
= make_cleanup (finish_thread_state_cleanup
,
3104 /* Now figure out what to do with the result of the result. */
3105 handle_inferior_event (ecs
);
3107 /* No error, don't finish the state yet. */
3108 discard_cleanups (old_chain_2
);
3110 /* Breakpoints and watchpoints are not installed on the target
3111 at this point, and signals are passed directly to the
3112 inferior, so this must mean the process is gone. */
3113 if (!ecs
->wait_some_more
)
3115 discard_cleanups (old_chain_1
);
3116 error (_("Program exited while detaching"));
3120 discard_cleanups (old_chain_1
);
3123 /* Wait for control to return from inferior to debugger.
3125 If inferior gets a signal, we may decide to start it up again
3126 instead of returning. That is why there is a loop in this function.
3127 When this function actually returns it means the inferior
3128 should be left stopped and GDB should read more commands. */
3131 wait_for_inferior (void)
3133 struct cleanup
*old_cleanups
;
3137 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3140 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
,
3145 struct execution_control_state ecss
;
3146 struct execution_control_state
*ecs
= &ecss
;
3147 struct cleanup
*old_chain
;
3148 ptid_t waiton_ptid
= minus_one_ptid
;
3150 memset (ecs
, 0, sizeof (*ecs
));
3152 overlay_cache_invalid
= 1;
3154 /* Flush target cache before starting to handle each event.
3155 Target was running and cache could be stale. This is just a
3156 heuristic. Running threads may modify target memory, but we
3157 don't get any event. */
3158 target_dcache_invalidate ();
3160 if (deprecated_target_wait_hook
)
3161 ecs
->ptid
= deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, 0);
3163 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, 0);
3166 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3168 /* If an error happens while handling the event, propagate GDB's
3169 knowledge of the executing state to the frontend/user running
3171 old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
3173 /* Now figure out what to do with the result of the result. */
3174 handle_inferior_event (ecs
);
3176 /* No error, don't finish the state yet. */
3177 discard_cleanups (old_chain
);
3179 if (!ecs
->wait_some_more
)
3183 do_cleanups (old_cleanups
);
3186 /* Cleanup that reinstalls the readline callback handler, if the
3187 target is running in the background. If while handling the target
3188 event something triggered a secondary prompt, like e.g., a
3189 pagination prompt, we'll have removed the callback handler (see
3190 gdb_readline_wrapper_line). Need to do this as we go back to the
3191 event loop, ready to process further input. Note this has no
3192 effect if the handler hasn't actually been removed, because calling
3193 rl_callback_handler_install resets the line buffer, thus losing
3197 reinstall_readline_callback_handler_cleanup (void *arg
)
3199 if (!interpreter_async
)
3201 /* We're not going back to the top level event loop yet. Don't
3202 install the readline callback, as it'd prep the terminal,
3203 readline-style (raw, noecho) (e.g., --batch). We'll install
3204 it the next time the prompt is displayed, when we're ready
3209 if (async_command_editing_p
&& !sync_execution
)
3210 gdb_rl_callback_handler_reinstall ();
3213 /* Asynchronous version of wait_for_inferior. It is called by the
3214 event loop whenever a change of state is detected on the file
3215 descriptor corresponding to the target. It can be called more than
3216 once to complete a single execution command. In such cases we need
3217 to keep the state in a global variable ECSS. If it is the last time
3218 that this function is called for a single execution command, then
3219 report to the user that the inferior has stopped, and do the
3220 necessary cleanups. */
3223 fetch_inferior_event (void *client_data
)
3225 struct execution_control_state ecss
;
3226 struct execution_control_state
*ecs
= &ecss
;
3227 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
3228 struct cleanup
*ts_old_chain
;
3229 int was_sync
= sync_execution
;
3231 ptid_t waiton_ptid
= minus_one_ptid
;
3233 memset (ecs
, 0, sizeof (*ecs
));
3235 /* End up with readline processing input, if necessary. */
3236 make_cleanup (reinstall_readline_callback_handler_cleanup
, NULL
);
3238 /* We're handling a live event, so make sure we're doing live
3239 debugging. If we're looking at traceframes while the target is
3240 running, we're going to need to get back to that mode after
3241 handling the event. */
3244 make_cleanup_restore_current_traceframe ();
3245 set_current_traceframe (-1);
3249 /* In non-stop mode, the user/frontend should not notice a thread
3250 switch due to internal events. Make sure we reverse to the
3251 user selected thread and frame after handling the event and
3252 running any breakpoint commands. */
3253 make_cleanup_restore_current_thread ();
3255 overlay_cache_invalid
= 1;
3256 /* Flush target cache before starting to handle each event. Target
3257 was running and cache could be stale. This is just a heuristic.
3258 Running threads may modify target memory, but we don't get any
3260 target_dcache_invalidate ();
3262 make_cleanup_restore_integer (&execution_direction
);
3263 execution_direction
= target_execution_direction ();
3265 if (deprecated_target_wait_hook
)
3267 deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
3269 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
3272 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3274 /* If an error happens while handling the event, propagate GDB's
3275 knowledge of the executing state to the frontend/user running
3278 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
3280 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &ecs
->ptid
);
3282 /* Get executed before make_cleanup_restore_current_thread above to apply
3283 still for the thread which has thrown the exception. */
3284 make_bpstat_clear_actions_cleanup ();
3286 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
, NULL
);
3288 /* Now figure out what to do with the result of the result. */
3289 handle_inferior_event (ecs
);
3291 if (!ecs
->wait_some_more
)
3293 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3295 delete_just_stopped_threads_infrun_breakpoints ();
3297 /* We may not find an inferior if this was a process exit. */
3298 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3301 if (target_has_execution
3302 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
3303 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
3304 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
3305 && ecs
->event_thread
->step_multi
3306 && ecs
->event_thread
->control
.stop_step
)
3307 inferior_event_handler (INF_EXEC_CONTINUE
, NULL
);
3310 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3315 /* No error, don't finish the thread states yet. */
3316 discard_cleanups (ts_old_chain
);
3318 /* Revert thread and frame. */
3319 do_cleanups (old_chain
);
3321 /* If the inferior was in sync execution mode, and now isn't,
3322 restore the prompt (a synchronous execution command has finished,
3323 and we're ready for input). */
3324 if (interpreter_async
&& was_sync
&& !sync_execution
)
3325 observer_notify_sync_execution_done ();
3329 && exec_done_display_p
3330 && (ptid_equal (inferior_ptid
, null_ptid
)
3331 || !is_running (inferior_ptid
)))
3332 printf_unfiltered (_("completed.\n"));
3335 /* Record the frame and location we're currently stepping through. */
3337 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3339 struct thread_info
*tp
= inferior_thread ();
3341 tp
->control
.step_frame_id
= get_frame_id (frame
);
3342 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3344 tp
->current_symtab
= sal
.symtab
;
3345 tp
->current_line
= sal
.line
;
3348 /* Clear context switchable stepping state. */
3351 init_thread_stepping_state (struct thread_info
*tss
)
3353 tss
->stepped_breakpoint
= 0;
3354 tss
->stepping_over_breakpoint
= 0;
3355 tss
->stepping_over_watchpoint
= 0;
3356 tss
->step_after_step_resume_breakpoint
= 0;
3359 /* Set the cached copy of the last ptid/waitstatus. */
3362 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
3364 target_last_wait_ptid
= ptid
;
3365 target_last_waitstatus
= status
;
3368 /* Return the cached copy of the last pid/waitstatus returned by
3369 target_wait()/deprecated_target_wait_hook(). The data is actually
3370 cached by handle_inferior_event(), which gets called immediately
3371 after target_wait()/deprecated_target_wait_hook(). */
3374 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
3376 *ptidp
= target_last_wait_ptid
;
3377 *status
= target_last_waitstatus
;
3381 nullify_last_target_wait_ptid (void)
3383 target_last_wait_ptid
= minus_one_ptid
;
3386 /* Switch thread contexts. */
3389 context_switch (ptid_t ptid
)
3391 if (debug_infrun
&& !ptid_equal (ptid
, inferior_ptid
))
3393 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
3394 target_pid_to_str (inferior_ptid
));
3395 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
3396 target_pid_to_str (ptid
));
3399 switch_to_thread (ptid
);
3403 adjust_pc_after_break (struct execution_control_state
*ecs
)
3405 struct regcache
*regcache
;
3406 struct gdbarch
*gdbarch
;
3407 struct address_space
*aspace
;
3408 CORE_ADDR breakpoint_pc
, decr_pc
;
3410 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3411 we aren't, just return.
3413 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3414 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3415 implemented by software breakpoints should be handled through the normal
3418 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3419 different signals (SIGILL or SIGEMT for instance), but it is less
3420 clear where the PC is pointing afterwards. It may not match
3421 gdbarch_decr_pc_after_break. I don't know any specific target that
3422 generates these signals at breakpoints (the code has been in GDB since at
3423 least 1992) so I can not guess how to handle them here.
3425 In earlier versions of GDB, a target with
3426 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3427 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3428 target with both of these set in GDB history, and it seems unlikely to be
3429 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3431 if (ecs
->ws
.kind
!= TARGET_WAITKIND_STOPPED
)
3434 if (ecs
->ws
.value
.sig
!= GDB_SIGNAL_TRAP
)
3437 /* In reverse execution, when a breakpoint is hit, the instruction
3438 under it has already been de-executed. The reported PC always
3439 points at the breakpoint address, so adjusting it further would
3440 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3443 B1 0x08000000 : INSN1
3444 B2 0x08000001 : INSN2
3446 PC -> 0x08000003 : INSN4
3448 Say you're stopped at 0x08000003 as above. Reverse continuing
3449 from that point should hit B2 as below. Reading the PC when the
3450 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3451 been de-executed already.
3453 B1 0x08000000 : INSN1
3454 B2 PC -> 0x08000001 : INSN2
3458 We can't apply the same logic as for forward execution, because
3459 we would wrongly adjust the PC to 0x08000000, since there's a
3460 breakpoint at PC - 1. We'd then report a hit on B1, although
3461 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3463 if (execution_direction
== EXEC_REVERSE
)
3466 /* If the target can tell whether the thread hit a SW breakpoint,
3467 trust it. Targets that can tell also adjust the PC
3469 if (target_supports_stopped_by_sw_breakpoint ())
3472 /* Note that relying on whether a breakpoint is planted in memory to
3473 determine this can fail. E.g,. the breakpoint could have been
3474 removed since. Or the thread could have been told to step an
3475 instruction the size of a breakpoint instruction, and only
3476 _after_ was a breakpoint inserted at its address. */
3478 /* If this target does not decrement the PC after breakpoints, then
3479 we have nothing to do. */
3480 regcache
= get_thread_regcache (ecs
->ptid
);
3481 gdbarch
= get_regcache_arch (regcache
);
3483 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3487 aspace
= get_regcache_aspace (regcache
);
3489 /* Find the location where (if we've hit a breakpoint) the
3490 breakpoint would be. */
3491 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
3493 /* If the target can't tell whether a software breakpoint triggered,
3494 fallback to figuring it out based on breakpoints we think were
3495 inserted in the target, and on whether the thread was stepped or
3498 /* Check whether there actually is a software breakpoint inserted at
3501 If in non-stop mode, a race condition is possible where we've
3502 removed a breakpoint, but stop events for that breakpoint were
3503 already queued and arrive later. To suppress those spurious
3504 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3505 and retire them after a number of stop events are reported. Note
3506 this is an heuristic and can thus get confused. The real fix is
3507 to get the "stopped by SW BP and needs adjustment" info out of
3508 the target/kernel (and thus never reach here; see above). */
3509 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
3510 || (non_stop
&& moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
3512 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, NULL
);
3514 if (record_full_is_used ())
3515 record_full_gdb_operation_disable_set ();
3517 /* When using hardware single-step, a SIGTRAP is reported for both
3518 a completed single-step and a software breakpoint. Need to
3519 differentiate between the two, as the latter needs adjusting
3520 but the former does not.
3522 The SIGTRAP can be due to a completed hardware single-step only if
3523 - we didn't insert software single-step breakpoints
3524 - this thread is currently being stepped
3526 If any of these events did not occur, we must have stopped due
3527 to hitting a software breakpoint, and have to back up to the
3530 As a special case, we could have hardware single-stepped a
3531 software breakpoint. In this case (prev_pc == breakpoint_pc),
3532 we also need to back up to the breakpoint address. */
3534 if (thread_has_single_step_breakpoints_set (ecs
->event_thread
)
3535 || !currently_stepping (ecs
->event_thread
)
3536 || (ecs
->event_thread
->stepped_breakpoint
3537 && ecs
->event_thread
->prev_pc
== breakpoint_pc
))
3538 regcache_write_pc (regcache
, breakpoint_pc
);
3540 do_cleanups (old_cleanups
);
3545 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
3547 for (frame
= get_prev_frame (frame
);
3549 frame
= get_prev_frame (frame
))
3551 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
3553 if (get_frame_type (frame
) != INLINE_FRAME
)
3560 /* Auxiliary function that handles syscall entry/return events.
3561 It returns 1 if the inferior should keep going (and GDB
3562 should ignore the event), or 0 if the event deserves to be
3566 handle_syscall_event (struct execution_control_state
*ecs
)
3568 struct regcache
*regcache
;
3571 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3572 context_switch (ecs
->ptid
);
3574 regcache
= get_thread_regcache (ecs
->ptid
);
3575 syscall_number
= ecs
->ws
.value
.syscall_number
;
3576 stop_pc
= regcache_read_pc (regcache
);
3578 if (catch_syscall_enabled () > 0
3579 && catching_syscall_number (syscall_number
) > 0)
3582 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
3585 ecs
->event_thread
->control
.stop_bpstat
3586 = bpstat_stop_status (get_regcache_aspace (regcache
),
3587 stop_pc
, ecs
->ptid
, &ecs
->ws
);
3589 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
3591 /* Catchpoint hit. */
3596 /* If no catchpoint triggered for this, then keep going. */
3601 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3604 fill_in_stop_func (struct gdbarch
*gdbarch
,
3605 struct execution_control_state
*ecs
)
3607 if (!ecs
->stop_func_filled_in
)
3609 /* Don't care about return value; stop_func_start and stop_func_name
3610 will both be 0 if it doesn't work. */
3611 find_pc_partial_function (stop_pc
, &ecs
->stop_func_name
,
3612 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
3613 ecs
->stop_func_start
3614 += gdbarch_deprecated_function_start_offset (gdbarch
);
3616 if (gdbarch_skip_entrypoint_p (gdbarch
))
3617 ecs
->stop_func_start
= gdbarch_skip_entrypoint (gdbarch
,
3618 ecs
->stop_func_start
);
3620 ecs
->stop_func_filled_in
= 1;
3625 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
3627 static enum stop_kind
3628 get_inferior_stop_soon (ptid_t ptid
)
3630 struct inferior
*inf
= find_inferior_ptid (ptid
);
3632 gdb_assert (inf
!= NULL
);
3633 return inf
->control
.stop_soon
;
3636 /* Given an execution control state that has been freshly filled in by
3637 an event from the inferior, figure out what it means and take
3640 The alternatives are:
3642 1) stop_waiting and return; to really stop and return to the
3645 2) keep_going and return; to wait for the next event (set
3646 ecs->event_thread->stepping_over_breakpoint to 1 to single step
3650 handle_inferior_event (struct execution_control_state
*ecs
)
3652 enum stop_kind stop_soon
;
3654 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
3656 /* We had an event in the inferior, but we are not interested in
3657 handling it at this level. The lower layers have already
3658 done what needs to be done, if anything.
3660 One of the possible circumstances for this is when the
3661 inferior produces output for the console. The inferior has
3662 not stopped, and we are ignoring the event. Another possible
3663 circumstance is any event which the lower level knows will be
3664 reported multiple times without an intervening resume. */
3666 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
3667 prepare_to_wait (ecs
);
3671 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
3672 && target_can_async_p () && !sync_execution
)
3674 /* There were no unwaited-for children left in the target, but,
3675 we're not synchronously waiting for events either. Just
3676 ignore. Otherwise, if we were running a synchronous
3677 execution command, we need to cancel it and give the user
3678 back the terminal. */
3680 fprintf_unfiltered (gdb_stdlog
,
3681 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3682 prepare_to_wait (ecs
);
3686 /* Cache the last pid/waitstatus. */
3687 set_last_target_status (ecs
->ptid
, ecs
->ws
);
3689 /* Always clear state belonging to the previous time we stopped. */
3690 stop_stack_dummy
= STOP_NONE
;
3692 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
3694 /* No unwaited-for children left. IOW, all resumed children
3697 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3699 stop_print_frame
= 0;
3704 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
3705 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
3707 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
3708 /* If it's a new thread, add it to the thread database. */
3709 if (ecs
->event_thread
== NULL
)
3710 ecs
->event_thread
= add_thread (ecs
->ptid
);
3712 /* Disable range stepping. If the next step request could use a
3713 range, this will be end up re-enabled then. */
3714 ecs
->event_thread
->control
.may_range_step
= 0;
3717 /* Dependent on valid ECS->EVENT_THREAD. */
3718 adjust_pc_after_break (ecs
);
3720 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3721 reinit_frame_cache ();
3723 breakpoint_retire_moribund ();
3725 /* First, distinguish signals caused by the debugger from signals
3726 that have to do with the program's own actions. Note that
3727 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3728 on the operating system version. Here we detect when a SIGILL or
3729 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3730 something similar for SIGSEGV, since a SIGSEGV will be generated
3731 when we're trying to execute a breakpoint instruction on a
3732 non-executable stack. This happens for call dummy breakpoints
3733 for architectures like SPARC that place call dummies on the
3735 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
3736 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
3737 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
3738 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
3740 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3742 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
3743 regcache_read_pc (regcache
)))
3746 fprintf_unfiltered (gdb_stdlog
,
3747 "infrun: Treating signal as SIGTRAP\n");
3748 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
3752 /* Mark the non-executing threads accordingly. In all-stop, all
3753 threads of all processes are stopped when we get any event
3754 reported. In non-stop mode, only the event thread stops. If
3755 we're handling a process exit in non-stop mode, there's nothing
3756 to do, as threads of the dead process are gone, and threads of
3757 any other process were left running. */
3759 set_executing (minus_one_ptid
, 0);
3760 else if (ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
3761 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
)
3762 set_executing (ecs
->ptid
, 0);
3764 switch (ecs
->ws
.kind
)
3766 case TARGET_WAITKIND_LOADED
:
3768 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
3769 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3770 context_switch (ecs
->ptid
);
3771 /* Ignore gracefully during startup of the inferior, as it might
3772 be the shell which has just loaded some objects, otherwise
3773 add the symbols for the newly loaded objects. Also ignore at
3774 the beginning of an attach or remote session; we will query
3775 the full list of libraries once the connection is
3778 stop_soon
= get_inferior_stop_soon (ecs
->ptid
);
3779 if (stop_soon
== NO_STOP_QUIETLY
)
3781 struct regcache
*regcache
;
3783 regcache
= get_thread_regcache (ecs
->ptid
);
3785 handle_solib_event ();
3787 ecs
->event_thread
->control
.stop_bpstat
3788 = bpstat_stop_status (get_regcache_aspace (regcache
),
3789 stop_pc
, ecs
->ptid
, &ecs
->ws
);
3791 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
3793 /* A catchpoint triggered. */
3794 process_event_stop_test (ecs
);
3798 /* If requested, stop when the dynamic linker notifies
3799 gdb of events. This allows the user to get control
3800 and place breakpoints in initializer routines for
3801 dynamically loaded objects (among other things). */
3802 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
3803 if (stop_on_solib_events
)
3805 /* Make sure we print "Stopped due to solib-event" in
3807 stop_print_frame
= 1;
3814 /* If we are skipping through a shell, or through shared library
3815 loading that we aren't interested in, resume the program. If
3816 we're running the program normally, also resume. */
3817 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
3819 /* Loading of shared libraries might have changed breakpoint
3820 addresses. Make sure new breakpoints are inserted. */
3821 if (stop_soon
== NO_STOP_QUIETLY
)
3822 insert_breakpoints ();
3823 resume (0, GDB_SIGNAL_0
);
3824 prepare_to_wait (ecs
);
3828 /* But stop if we're attaching or setting up a remote
3830 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
3831 || stop_soon
== STOP_QUIETLY_REMOTE
)
3834 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
3839 internal_error (__FILE__
, __LINE__
,
3840 _("unhandled stop_soon: %d"), (int) stop_soon
);
3842 case TARGET_WAITKIND_SPURIOUS
:
3844 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3845 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3846 context_switch (ecs
->ptid
);
3847 resume (0, GDB_SIGNAL_0
);
3848 prepare_to_wait (ecs
);
3851 case TARGET_WAITKIND_EXITED
:
3852 case TARGET_WAITKIND_SIGNALLED
:
3855 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
3856 fprintf_unfiltered (gdb_stdlog
,
3857 "infrun: TARGET_WAITKIND_EXITED\n");
3859 fprintf_unfiltered (gdb_stdlog
,
3860 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3863 inferior_ptid
= ecs
->ptid
;
3864 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
3865 set_current_program_space (current_inferior ()->pspace
);
3866 handle_vfork_child_exec_or_exit (0);
3867 target_terminal_ours (); /* Must do this before mourn anyway. */
3869 /* Clearing any previous state of convenience variables. */
3870 clear_exit_convenience_vars ();
3872 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
3874 /* Record the exit code in the convenience variable $_exitcode, so
3875 that the user can inspect this again later. */
3876 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3877 (LONGEST
) ecs
->ws
.value
.integer
);
3879 /* Also record this in the inferior itself. */
3880 current_inferior ()->has_exit_code
= 1;
3881 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
3883 /* Support the --return-child-result option. */
3884 return_child_result_value
= ecs
->ws
.value
.integer
;
3886 observer_notify_exited (ecs
->ws
.value
.integer
);
3890 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3891 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3893 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
3895 /* Set the value of the internal variable $_exitsignal,
3896 which holds the signal uncaught by the inferior. */
3897 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
3898 gdbarch_gdb_signal_to_target (gdbarch
,
3899 ecs
->ws
.value
.sig
));
3903 /* We don't have access to the target's method used for
3904 converting between signal numbers (GDB's internal
3905 representation <-> target's representation).
3906 Therefore, we cannot do a good job at displaying this
3907 information to the user. It's better to just warn
3908 her about it (if infrun debugging is enabled), and
3911 fprintf_filtered (gdb_stdlog
, _("\
3912 Cannot fill $_exitsignal with the correct signal number.\n"));
3915 observer_notify_signal_exited (ecs
->ws
.value
.sig
);
3918 gdb_flush (gdb_stdout
);
3919 target_mourn_inferior ();
3920 stop_print_frame
= 0;
3924 /* The following are the only cases in which we keep going;
3925 the above cases end in a continue or goto. */
3926 case TARGET_WAITKIND_FORKED
:
3927 case TARGET_WAITKIND_VFORKED
:
3930 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
3931 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
3933 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_VFORKED\n");
3936 /* Check whether the inferior is displaced stepping. */
3938 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3939 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3940 struct displaced_step_inferior_state
*displaced
3941 = get_displaced_stepping_state (ptid_get_pid (ecs
->ptid
));
3943 /* If checking displaced stepping is supported, and thread
3944 ecs->ptid is displaced stepping. */
3945 if (displaced
&& ptid_equal (displaced
->step_ptid
, ecs
->ptid
))
3947 struct inferior
*parent_inf
3948 = find_inferior_ptid (ecs
->ptid
);
3949 struct regcache
*child_regcache
;
3950 CORE_ADDR parent_pc
;
3952 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3953 indicating that the displaced stepping of syscall instruction
3954 has been done. Perform cleanup for parent process here. Note
3955 that this operation also cleans up the child process for vfork,
3956 because their pages are shared. */
3957 displaced_step_fixup (ecs
->ptid
, GDB_SIGNAL_TRAP
);
3959 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
3961 /* Restore scratch pad for child process. */
3962 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
3965 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3966 the child's PC is also within the scratchpad. Set the child's PC
3967 to the parent's PC value, which has already been fixed up.
3968 FIXME: we use the parent's aspace here, although we're touching
3969 the child, because the child hasn't been added to the inferior
3970 list yet at this point. */
3973 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
3975 parent_inf
->aspace
);
3976 /* Read PC value of parent process. */
3977 parent_pc
= regcache_read_pc (regcache
);
3979 if (debug_displaced
)
3980 fprintf_unfiltered (gdb_stdlog
,
3981 "displaced: write child pc from %s to %s\n",
3983 regcache_read_pc (child_regcache
)),
3984 paddress (gdbarch
, parent_pc
));
3986 regcache_write_pc (child_regcache
, parent_pc
);
3990 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3991 context_switch (ecs
->ptid
);
3993 /* Immediately detach breakpoints from the child before there's
3994 any chance of letting the user delete breakpoints from the
3995 breakpoint lists. If we don't do this early, it's easy to
3996 leave left over traps in the child, vis: "break foo; catch
3997 fork; c; <fork>; del; c; <child calls foo>". We only follow
3998 the fork on the last `continue', and by that time the
3999 breakpoint at "foo" is long gone from the breakpoint table.
4000 If we vforked, then we don't need to unpatch here, since both
4001 parent and child are sharing the same memory pages; we'll
4002 need to unpatch at follow/detach time instead to be certain
4003 that new breakpoints added between catchpoint hit time and
4004 vfork follow are detached. */
4005 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
4007 /* This won't actually modify the breakpoint list, but will
4008 physically remove the breakpoints from the child. */
4009 detach_breakpoints (ecs
->ws
.value
.related_pid
);
4012 delete_just_stopped_threads_single_step_breakpoints ();
4014 /* In case the event is caught by a catchpoint, remember that
4015 the event is to be followed at the next resume of the thread,
4016 and not immediately. */
4017 ecs
->event_thread
->pending_follow
= ecs
->ws
;
4019 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4021 ecs
->event_thread
->control
.stop_bpstat
4022 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4023 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4025 /* If no catchpoint triggered for this, then keep going. Note
4026 that we're interested in knowing the bpstat actually causes a
4027 stop, not just if it may explain the signal. Software
4028 watchpoints, for example, always appear in the bpstat. */
4029 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4035 = (follow_fork_mode_string
== follow_fork_mode_child
);
4037 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4039 should_resume
= follow_fork ();
4042 child
= ecs
->ws
.value
.related_pid
;
4044 /* In non-stop mode, also resume the other branch. */
4045 if (non_stop
&& !detach_fork
)
4048 switch_to_thread (parent
);
4050 switch_to_thread (child
);
4052 ecs
->event_thread
= inferior_thread ();
4053 ecs
->ptid
= inferior_ptid
;
4058 switch_to_thread (child
);
4060 switch_to_thread (parent
);
4062 ecs
->event_thread
= inferior_thread ();
4063 ecs
->ptid
= inferior_ptid
;
4071 process_event_stop_test (ecs
);
4074 case TARGET_WAITKIND_VFORK_DONE
:
4075 /* Done with the shared memory region. Re-insert breakpoints in
4076 the parent, and keep going. */
4079 fprintf_unfiltered (gdb_stdlog
,
4080 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
4082 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4083 context_switch (ecs
->ptid
);
4085 current_inferior ()->waiting_for_vfork_done
= 0;
4086 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
4087 /* This also takes care of reinserting breakpoints in the
4088 previously locked inferior. */
4092 case TARGET_WAITKIND_EXECD
:
4094 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
4096 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4097 context_switch (ecs
->ptid
);
4099 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4101 /* Do whatever is necessary to the parent branch of the vfork. */
4102 handle_vfork_child_exec_or_exit (1);
4104 /* This causes the eventpoints and symbol table to be reset.
4105 Must do this now, before trying to determine whether to
4107 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
4109 ecs
->event_thread
->control
.stop_bpstat
4110 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4111 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4113 /* Note that this may be referenced from inside
4114 bpstat_stop_status above, through inferior_has_execd. */
4115 xfree (ecs
->ws
.value
.execd_pathname
);
4116 ecs
->ws
.value
.execd_pathname
= NULL
;
4118 /* If no catchpoint triggered for this, then keep going. */
4119 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4121 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4125 process_event_stop_test (ecs
);
4128 /* Be careful not to try to gather much state about a thread
4129 that's in a syscall. It's frequently a losing proposition. */
4130 case TARGET_WAITKIND_SYSCALL_ENTRY
:
4132 fprintf_unfiltered (gdb_stdlog
,
4133 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
4134 /* Getting the current syscall number. */
4135 if (handle_syscall_event (ecs
) == 0)
4136 process_event_stop_test (ecs
);
4139 /* Before examining the threads further, step this thread to
4140 get it entirely out of the syscall. (We get notice of the
4141 event when the thread is just on the verge of exiting a
4142 syscall. Stepping one instruction seems to get it back
4144 case TARGET_WAITKIND_SYSCALL_RETURN
:
4146 fprintf_unfiltered (gdb_stdlog
,
4147 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
4148 if (handle_syscall_event (ecs
) == 0)
4149 process_event_stop_test (ecs
);
4152 case TARGET_WAITKIND_STOPPED
:
4154 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
4155 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
4156 handle_signal_stop (ecs
);
4159 case TARGET_WAITKIND_NO_HISTORY
:
4161 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
4162 /* Reverse execution: target ran out of history info. */
4164 delete_just_stopped_threads_single_step_breakpoints ();
4165 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4166 observer_notify_no_history ();
4172 /* Come here when the program has stopped with a signal. */
4175 handle_signal_stop (struct execution_control_state
*ecs
)
4177 struct frame_info
*frame
;
4178 struct gdbarch
*gdbarch
;
4179 int stopped_by_watchpoint
;
4180 enum stop_kind stop_soon
;
4183 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
4185 /* Do we need to clean up the state of a thread that has
4186 completed a displaced single-step? (Doing so usually affects
4187 the PC, so do it here, before we set stop_pc.) */
4188 displaced_step_fixup (ecs
->ptid
,
4189 ecs
->event_thread
->suspend
.stop_signal
);
4191 /* If we either finished a single-step or hit a breakpoint, but
4192 the user wanted this thread to be stopped, pretend we got a
4193 SIG0 (generic unsignaled stop). */
4194 if (ecs
->event_thread
->stop_requested
4195 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
4196 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4198 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4202 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
4203 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
4204 struct cleanup
*old_chain
= save_inferior_ptid ();
4206 inferior_ptid
= ecs
->ptid
;
4208 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
4209 paddress (gdbarch
, stop_pc
));
4210 if (target_stopped_by_watchpoint ())
4214 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
4216 if (target_stopped_data_address (¤t_target
, &addr
))
4217 fprintf_unfiltered (gdb_stdlog
,
4218 "infrun: stopped data address = %s\n",
4219 paddress (gdbarch
, addr
));
4221 fprintf_unfiltered (gdb_stdlog
,
4222 "infrun: (no data address available)\n");
4225 do_cleanups (old_chain
);
4228 /* This is originated from start_remote(), start_inferior() and
4229 shared libraries hook functions. */
4230 stop_soon
= get_inferior_stop_soon (ecs
->ptid
);
4231 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
4233 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4234 context_switch (ecs
->ptid
);
4236 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4237 stop_print_frame
= 1;
4242 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4245 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4246 context_switch (ecs
->ptid
);
4248 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
4249 stop_print_frame
= 0;
4254 /* This originates from attach_command(). We need to overwrite
4255 the stop_signal here, because some kernels don't ignore a
4256 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4257 See more comments in inferior.h. On the other hand, if we
4258 get a non-SIGSTOP, report it to the user - assume the backend
4259 will handle the SIGSTOP if it should show up later.
4261 Also consider that the attach is complete when we see a
4262 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4263 target extended-remote report it instead of a SIGSTOP
4264 (e.g. gdbserver). We already rely on SIGTRAP being our
4265 signal, so this is no exception.
4267 Also consider that the attach is complete when we see a
4268 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4269 the target to stop all threads of the inferior, in case the
4270 low level attach operation doesn't stop them implicitly. If
4271 they weren't stopped implicitly, then the stub will report a
4272 GDB_SIGNAL_0, meaning: stopped for no particular reason
4273 other than GDB's request. */
4274 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4275 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
4276 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4277 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
4279 stop_print_frame
= 1;
4281 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4285 /* See if something interesting happened to the non-current thread. If
4286 so, then switch to that thread. */
4287 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4290 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
4292 context_switch (ecs
->ptid
);
4294 if (deprecated_context_hook
)
4295 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
4298 /* At this point, get hold of the now-current thread's frame. */
4299 frame
= get_current_frame ();
4300 gdbarch
= get_frame_arch (frame
);
4302 /* Pull the single step breakpoints out of the target. */
4303 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
4305 struct regcache
*regcache
;
4306 struct address_space
*aspace
;
4309 regcache
= get_thread_regcache (ecs
->ptid
);
4310 aspace
= get_regcache_aspace (regcache
);
4311 pc
= regcache_read_pc (regcache
);
4313 /* However, before doing so, if this single-step breakpoint was
4314 actually for another thread, set this thread up for moving
4316 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
4319 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
4323 fprintf_unfiltered (gdb_stdlog
,
4324 "infrun: [%s] hit another thread's "
4325 "single-step breakpoint\n",
4326 target_pid_to_str (ecs
->ptid
));
4328 ecs
->hit_singlestep_breakpoint
= 1;
4335 fprintf_unfiltered (gdb_stdlog
,
4336 "infrun: [%s] hit its "
4337 "single-step breakpoint\n",
4338 target_pid_to_str (ecs
->ptid
));
4342 delete_just_stopped_threads_single_step_breakpoints ();
4344 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4345 && ecs
->event_thread
->control
.trap_expected
4346 && ecs
->event_thread
->stepping_over_watchpoint
)
4347 stopped_by_watchpoint
= 0;
4349 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
4351 /* If necessary, step over this watchpoint. We'll be back to display
4353 if (stopped_by_watchpoint
4354 && (target_have_steppable_watchpoint
4355 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
4357 /* At this point, we are stopped at an instruction which has
4358 attempted to write to a piece of memory under control of
4359 a watchpoint. The instruction hasn't actually executed
4360 yet. If we were to evaluate the watchpoint expression
4361 now, we would get the old value, and therefore no change
4362 would seem to have occurred.
4364 In order to make watchpoints work `right', we really need
4365 to complete the memory write, and then evaluate the
4366 watchpoint expression. We do this by single-stepping the
4369 It may not be necessary to disable the watchpoint to step over
4370 it. For example, the PA can (with some kernel cooperation)
4371 single step over a watchpoint without disabling the watchpoint.
4373 It is far more common to need to disable a watchpoint to step
4374 the inferior over it. If we have non-steppable watchpoints,
4375 we must disable the current watchpoint; it's simplest to
4376 disable all watchpoints.
4378 Any breakpoint at PC must also be stepped over -- if there's
4379 one, it will have already triggered before the watchpoint
4380 triggered, and we either already reported it to the user, or
4381 it didn't cause a stop and we called keep_going. In either
4382 case, if there was a breakpoint at PC, we must be trying to
4384 ecs
->event_thread
->stepping_over_watchpoint
= 1;
4389 ecs
->event_thread
->stepping_over_breakpoint
= 0;
4390 ecs
->event_thread
->stepping_over_watchpoint
= 0;
4391 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
4392 ecs
->event_thread
->control
.stop_step
= 0;
4393 stop_print_frame
= 1;
4394 stopped_by_random_signal
= 0;
4396 /* Hide inlined functions starting here, unless we just performed stepi or
4397 nexti. After stepi and nexti, always show the innermost frame (not any
4398 inline function call sites). */
4399 if (ecs
->event_thread
->control
.step_range_end
!= 1)
4401 struct address_space
*aspace
=
4402 get_regcache_aspace (get_thread_regcache (ecs
->ptid
));
4404 /* skip_inline_frames is expensive, so we avoid it if we can
4405 determine that the address is one where functions cannot have
4406 been inlined. This improves performance with inferiors that
4407 load a lot of shared libraries, because the solib event
4408 breakpoint is defined as the address of a function (i.e. not
4409 inline). Note that we have to check the previous PC as well
4410 as the current one to catch cases when we have just
4411 single-stepped off a breakpoint prior to reinstating it.
4412 Note that we're assuming that the code we single-step to is
4413 not inline, but that's not definitive: there's nothing
4414 preventing the event breakpoint function from containing
4415 inlined code, and the single-step ending up there. If the
4416 user had set a breakpoint on that inlined code, the missing
4417 skip_inline_frames call would break things. Fortunately
4418 that's an extremely unlikely scenario. */
4419 if (!pc_at_non_inline_function (aspace
, stop_pc
, &ecs
->ws
)
4420 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4421 && ecs
->event_thread
->control
.trap_expected
4422 && pc_at_non_inline_function (aspace
,
4423 ecs
->event_thread
->prev_pc
,
4426 skip_inline_frames (ecs
->ptid
);
4428 /* Re-fetch current thread's frame in case that invalidated
4430 frame
= get_current_frame ();
4431 gdbarch
= get_frame_arch (frame
);
4435 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4436 && ecs
->event_thread
->control
.trap_expected
4437 && gdbarch_single_step_through_delay_p (gdbarch
)
4438 && currently_stepping (ecs
->event_thread
))
4440 /* We're trying to step off a breakpoint. Turns out that we're
4441 also on an instruction that needs to be stepped multiple
4442 times before it's been fully executing. E.g., architectures
4443 with a delay slot. It needs to be stepped twice, once for
4444 the instruction and once for the delay slot. */
4445 int step_through_delay
4446 = gdbarch_single_step_through_delay (gdbarch
, frame
);
4448 if (debug_infrun
&& step_through_delay
)
4449 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
4450 if (ecs
->event_thread
->control
.step_range_end
== 0
4451 && step_through_delay
)
4453 /* The user issued a continue when stopped at a breakpoint.
4454 Set up for another trap and get out of here. */
4455 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4459 else if (step_through_delay
)
4461 /* The user issued a step when stopped at a breakpoint.
4462 Maybe we should stop, maybe we should not - the delay
4463 slot *might* correspond to a line of source. In any
4464 case, don't decide that here, just set
4465 ecs->stepping_over_breakpoint, making sure we
4466 single-step again before breakpoints are re-inserted. */
4467 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4471 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4472 handles this event. */
4473 ecs
->event_thread
->control
.stop_bpstat
4474 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4475 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4477 /* Following in case break condition called a
4479 stop_print_frame
= 1;
4481 /* This is where we handle "moribund" watchpoints. Unlike
4482 software breakpoints traps, hardware watchpoint traps are
4483 always distinguishable from random traps. If no high-level
4484 watchpoint is associated with the reported stop data address
4485 anymore, then the bpstat does not explain the signal ---
4486 simply make sure to ignore it if `stopped_by_watchpoint' is
4490 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4491 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
4493 && stopped_by_watchpoint
)
4494 fprintf_unfiltered (gdb_stdlog
,
4495 "infrun: no user watchpoint explains "
4496 "watchpoint SIGTRAP, ignoring\n");
4498 /* NOTE: cagney/2003-03-29: These checks for a random signal
4499 at one stage in the past included checks for an inferior
4500 function call's call dummy's return breakpoint. The original
4501 comment, that went with the test, read:
4503 ``End of a stack dummy. Some systems (e.g. Sony news) give
4504 another signal besides SIGTRAP, so check here as well as
4507 If someone ever tries to get call dummys on a
4508 non-executable stack to work (where the target would stop
4509 with something like a SIGSEGV), then those tests might need
4510 to be re-instated. Given, however, that the tests were only
4511 enabled when momentary breakpoints were not being used, I
4512 suspect that it won't be the case.
4514 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4515 be necessary for call dummies on a non-executable stack on
4518 /* See if the breakpoints module can explain the signal. */
4520 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
4521 ecs
->event_thread
->suspend
.stop_signal
);
4523 /* Maybe this was a trap for a software breakpoint that has since
4525 if (random_signal
&& target_stopped_by_sw_breakpoint ())
4527 if (program_breakpoint_here_p (gdbarch
, stop_pc
))
4529 struct regcache
*regcache
;
4532 /* Re-adjust PC to what the program would see if GDB was not
4534 regcache
= get_thread_regcache (ecs
->event_thread
->ptid
);
4535 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4538 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, NULL
);
4540 if (record_full_is_used ())
4541 record_full_gdb_operation_disable_set ();
4543 regcache_write_pc (regcache
, stop_pc
+ decr_pc
);
4545 do_cleanups (old_cleanups
);
4550 /* A delayed software breakpoint event. Ignore the trap. */
4552 fprintf_unfiltered (gdb_stdlog
,
4553 "infrun: delayed software breakpoint "
4554 "trap, ignoring\n");
4559 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
4560 has since been removed. */
4561 if (random_signal
&& target_stopped_by_hw_breakpoint ())
4563 /* A delayed hardware breakpoint event. Ignore the trap. */
4565 fprintf_unfiltered (gdb_stdlog
,
4566 "infrun: delayed hardware breakpoint/watchpoint "
4567 "trap, ignoring\n");
4571 /* If not, perhaps stepping/nexting can. */
4573 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4574 && currently_stepping (ecs
->event_thread
));
4576 /* Perhaps the thread hit a single-step breakpoint of _another_
4577 thread. Single-step breakpoints are transparent to the
4578 breakpoints module. */
4580 random_signal
= !ecs
->hit_singlestep_breakpoint
;
4582 /* No? Perhaps we got a moribund watchpoint. */
4584 random_signal
= !stopped_by_watchpoint
;
4586 /* For the program's own signals, act according to
4587 the signal handling tables. */
4591 /* Signal not for debugging purposes. */
4592 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
4593 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
4596 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
4597 gdb_signal_to_symbol_string (stop_signal
));
4599 stopped_by_random_signal
= 1;
4601 /* Always stop on signals if we're either just gaining control
4602 of the program, or the user explicitly requested this thread
4603 to remain stopped. */
4604 if (stop_soon
!= NO_STOP_QUIETLY
4605 || ecs
->event_thread
->stop_requested
4607 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
4613 /* Notify observers the signal has "handle print" set. Note we
4614 returned early above if stopping; normal_stop handles the
4615 printing in that case. */
4616 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
4618 /* The signal table tells us to print about this signal. */
4619 target_terminal_ours_for_output ();
4620 observer_notify_signal_received (ecs
->event_thread
->suspend
.stop_signal
);
4621 target_terminal_inferior ();
4624 /* Clear the signal if it should not be passed. */
4625 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
4626 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4628 if (ecs
->event_thread
->prev_pc
== stop_pc
4629 && ecs
->event_thread
->control
.trap_expected
4630 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
4632 /* We were just starting a new sequence, attempting to
4633 single-step off of a breakpoint and expecting a SIGTRAP.
4634 Instead this signal arrives. This signal will take us out
4635 of the stepping range so GDB needs to remember to, when
4636 the signal handler returns, resume stepping off that
4638 /* To simplify things, "continue" is forced to use the same
4639 code paths as single-step - set a breakpoint at the
4640 signal return address and then, once hit, step off that
4643 fprintf_unfiltered (gdb_stdlog
,
4644 "infrun: signal arrived while stepping over "
4647 insert_hp_step_resume_breakpoint_at_frame (frame
);
4648 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
4649 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4650 ecs
->event_thread
->control
.trap_expected
= 0;
4652 /* If we were nexting/stepping some other thread, switch to
4653 it, so that we don't continue it, losing control. */
4654 if (!switch_back_to_stepped_thread (ecs
))
4659 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
4660 && (pc_in_thread_step_range (stop_pc
, ecs
->event_thread
)
4661 || ecs
->event_thread
->control
.step_range_end
== 1)
4662 && frame_id_eq (get_stack_frame_id (frame
),
4663 ecs
->event_thread
->control
.step_stack_frame_id
)
4664 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
4666 /* The inferior is about to take a signal that will take it
4667 out of the single step range. Set a breakpoint at the
4668 current PC (which is presumably where the signal handler
4669 will eventually return) and then allow the inferior to
4672 Note that this is only needed for a signal delivered
4673 while in the single-step range. Nested signals aren't a
4674 problem as they eventually all return. */
4676 fprintf_unfiltered (gdb_stdlog
,
4677 "infrun: signal may take us out of "
4678 "single-step range\n");
4680 insert_hp_step_resume_breakpoint_at_frame (frame
);
4681 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
4682 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4683 ecs
->event_thread
->control
.trap_expected
= 0;
4688 /* Note: step_resume_breakpoint may be non-NULL. This occures
4689 when either there's a nested signal, or when there's a
4690 pending signal enabled just as the signal handler returns
4691 (leaving the inferior at the step-resume-breakpoint without
4692 actually executing it). Either way continue until the
4693 breakpoint is really hit. */
4695 if (!switch_back_to_stepped_thread (ecs
))
4698 fprintf_unfiltered (gdb_stdlog
,
4699 "infrun: random signal, keep going\n");
4706 process_event_stop_test (ecs
);
4709 /* Come here when we've got some debug event / signal we can explain
4710 (IOW, not a random signal), and test whether it should cause a
4711 stop, or whether we should resume the inferior (transparently).
4712 E.g., could be a breakpoint whose condition evaluates false; we
4713 could be still stepping within the line; etc. */
4716 process_event_stop_test (struct execution_control_state
*ecs
)
4718 struct symtab_and_line stop_pc_sal
;
4719 struct frame_info
*frame
;
4720 struct gdbarch
*gdbarch
;
4721 CORE_ADDR jmp_buf_pc
;
4722 struct bpstat_what what
;
4724 /* Handle cases caused by hitting a breakpoint. */
4726 frame
= get_current_frame ();
4727 gdbarch
= get_frame_arch (frame
);
4729 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
4731 if (what
.call_dummy
)
4733 stop_stack_dummy
= what
.call_dummy
;
4736 /* If we hit an internal event that triggers symbol changes, the
4737 current frame will be invalidated within bpstat_what (e.g., if we
4738 hit an internal solib event). Re-fetch it. */
4739 frame
= get_current_frame ();
4740 gdbarch
= get_frame_arch (frame
);
4742 switch (what
.main_action
)
4744 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
4745 /* If we hit the breakpoint at longjmp while stepping, we
4746 install a momentary breakpoint at the target of the
4750 fprintf_unfiltered (gdb_stdlog
,
4751 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4753 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4755 if (what
.is_longjmp
)
4757 struct value
*arg_value
;
4759 /* If we set the longjmp breakpoint via a SystemTap probe,
4760 then use it to extract the arguments. The destination PC
4761 is the third argument to the probe. */
4762 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
4765 jmp_buf_pc
= value_as_address (arg_value
);
4766 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
4768 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
4769 || !gdbarch_get_longjmp_target (gdbarch
,
4770 frame
, &jmp_buf_pc
))
4773 fprintf_unfiltered (gdb_stdlog
,
4774 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4775 "(!gdbarch_get_longjmp_target)\n");
4780 /* Insert a breakpoint at resume address. */
4781 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
4784 check_exception_resume (ecs
, frame
);
4788 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
4790 struct frame_info
*init_frame
;
4792 /* There are several cases to consider.
4794 1. The initiating frame no longer exists. In this case we
4795 must stop, because the exception or longjmp has gone too
4798 2. The initiating frame exists, and is the same as the
4799 current frame. We stop, because the exception or longjmp
4802 3. The initiating frame exists and is different from the
4803 current frame. This means the exception or longjmp has
4804 been caught beneath the initiating frame, so keep going.
4806 4. longjmp breakpoint has been placed just to protect
4807 against stale dummy frames and user is not interested in
4808 stopping around longjmps. */
4811 fprintf_unfiltered (gdb_stdlog
,
4812 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4814 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
4816 delete_exception_resume_breakpoint (ecs
->event_thread
);
4818 if (what
.is_longjmp
)
4820 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
4822 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
4830 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
4834 struct frame_id current_id
4835 = get_frame_id (get_current_frame ());
4836 if (frame_id_eq (current_id
,
4837 ecs
->event_thread
->initiating_frame
))
4839 /* Case 2. Fall through. */
4849 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
4851 delete_step_resume_breakpoint (ecs
->event_thread
);
4853 end_stepping_range (ecs
);
4857 case BPSTAT_WHAT_SINGLE
:
4859 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
4860 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4861 /* Still need to check other stuff, at least the case where we
4862 are stepping and step out of the right range. */
4865 case BPSTAT_WHAT_STEP_RESUME
:
4867 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4869 delete_step_resume_breakpoint (ecs
->event_thread
);
4870 if (ecs
->event_thread
->control
.proceed_to_finish
4871 && execution_direction
== EXEC_REVERSE
)
4873 struct thread_info
*tp
= ecs
->event_thread
;
4875 /* We are finishing a function in reverse, and just hit the
4876 step-resume breakpoint at the start address of the
4877 function, and we're almost there -- just need to back up
4878 by one more single-step, which should take us back to the
4880 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
4884 fill_in_stop_func (gdbarch
, ecs
);
4885 if (stop_pc
== ecs
->stop_func_start
4886 && execution_direction
== EXEC_REVERSE
)
4888 /* We are stepping over a function call in reverse, and just
4889 hit the step-resume breakpoint at the start address of
4890 the function. Go back to single-stepping, which should
4891 take us back to the function call. */
4892 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4898 case BPSTAT_WHAT_STOP_NOISY
:
4900 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4901 stop_print_frame
= 1;
4903 /* Assume the thread stopped for a breapoint. We'll still check
4904 whether a/the breakpoint is there when the thread is next
4906 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4911 case BPSTAT_WHAT_STOP_SILENT
:
4913 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4914 stop_print_frame
= 0;
4916 /* Assume the thread stopped for a breapoint. We'll still check
4917 whether a/the breakpoint is there when the thread is next
4919 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4923 case BPSTAT_WHAT_HP_STEP_RESUME
:
4925 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4927 delete_step_resume_breakpoint (ecs
->event_thread
);
4928 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
4930 /* Back when the step-resume breakpoint was inserted, we
4931 were trying to single-step off a breakpoint. Go back to
4933 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
4934 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4940 case BPSTAT_WHAT_KEEP_CHECKING
:
4944 /* If we stepped a permanent breakpoint and we had a high priority
4945 step-resume breakpoint for the address we stepped, but we didn't
4946 hit it, then we must have stepped into the signal handler. The
4947 step-resume was only necessary to catch the case of _not_
4948 stepping into the handler, so delete it, and fall through to
4949 checking whether the step finished. */
4950 if (ecs
->event_thread
->stepped_breakpoint
)
4952 struct breakpoint
*sr_bp
4953 = ecs
->event_thread
->control
.step_resume_breakpoint
;
4955 if (sr_bp
->loc
->permanent
4956 && sr_bp
->type
== bp_hp_step_resume
4957 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
4960 fprintf_unfiltered (gdb_stdlog
,
4961 "infrun: stepped permanent breakpoint, stopped in "
4963 delete_step_resume_breakpoint (ecs
->event_thread
);
4964 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
4968 /* We come here if we hit a breakpoint but should not stop for it.
4969 Possibly we also were stepping and should stop for that. So fall
4970 through and test for stepping. But, if not stepping, do not
4973 /* In all-stop mode, if we're currently stepping but have stopped in
4974 some other thread, we need to switch back to the stepped thread. */
4975 if (switch_back_to_stepped_thread (ecs
))
4978 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
4981 fprintf_unfiltered (gdb_stdlog
,
4982 "infrun: step-resume breakpoint is inserted\n");
4984 /* Having a step-resume breakpoint overrides anything
4985 else having to do with stepping commands until
4986 that breakpoint is reached. */
4991 if (ecs
->event_thread
->control
.step_range_end
== 0)
4994 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
4995 /* Likewise if we aren't even stepping. */
5000 /* Re-fetch current thread's frame in case the code above caused
5001 the frame cache to be re-initialized, making our FRAME variable
5002 a dangling pointer. */
5003 frame
= get_current_frame ();
5004 gdbarch
= get_frame_arch (frame
);
5005 fill_in_stop_func (gdbarch
, ecs
);
5007 /* If stepping through a line, keep going if still within it.
5009 Note that step_range_end is the address of the first instruction
5010 beyond the step range, and NOT the address of the last instruction
5013 Note also that during reverse execution, we may be stepping
5014 through a function epilogue and therefore must detect when
5015 the current-frame changes in the middle of a line. */
5017 if (pc_in_thread_step_range (stop_pc
, ecs
->event_thread
)
5018 && (execution_direction
!= EXEC_REVERSE
5019 || frame_id_eq (get_frame_id (frame
),
5020 ecs
->event_thread
->control
.step_frame_id
)))
5024 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
5025 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
5026 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
5028 /* Tentatively re-enable range stepping; `resume' disables it if
5029 necessary (e.g., if we're stepping over a breakpoint or we
5030 have software watchpoints). */
5031 ecs
->event_thread
->control
.may_range_step
= 1;
5033 /* When stepping backward, stop at beginning of line range
5034 (unless it's the function entry point, in which case
5035 keep going back to the call point). */
5036 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
5037 && stop_pc
!= ecs
->stop_func_start
5038 && execution_direction
== EXEC_REVERSE
)
5039 end_stepping_range (ecs
);
5046 /* We stepped out of the stepping range. */
5048 /* If we are stepping at the source level and entered the runtime
5049 loader dynamic symbol resolution code...
5051 EXEC_FORWARD: we keep on single stepping until we exit the run
5052 time loader code and reach the callee's address.
5054 EXEC_REVERSE: we've already executed the callee (backward), and
5055 the runtime loader code is handled just like any other
5056 undebuggable function call. Now we need only keep stepping
5057 backward through the trampoline code, and that's handled further
5058 down, so there is nothing for us to do here. */
5060 if (execution_direction
!= EXEC_REVERSE
5061 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
5062 && in_solib_dynsym_resolve_code (stop_pc
))
5064 CORE_ADDR pc_after_resolver
=
5065 gdbarch_skip_solib_resolver (gdbarch
, stop_pc
);
5068 fprintf_unfiltered (gdb_stdlog
,
5069 "infrun: stepped into dynsym resolve code\n");
5071 if (pc_after_resolver
)
5073 /* Set up a step-resume breakpoint at the address
5074 indicated by SKIP_SOLIB_RESOLVER. */
5075 struct symtab_and_line sr_sal
;
5078 sr_sal
.pc
= pc_after_resolver
;
5079 sr_sal
.pspace
= get_frame_program_space (frame
);
5081 insert_step_resume_breakpoint_at_sal (gdbarch
,
5082 sr_sal
, null_frame_id
);
5089 if (ecs
->event_thread
->control
.step_range_end
!= 1
5090 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
5091 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
5092 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
5095 fprintf_unfiltered (gdb_stdlog
,
5096 "infrun: stepped into signal trampoline\n");
5097 /* The inferior, while doing a "step" or "next", has ended up in
5098 a signal trampoline (either by a signal being delivered or by
5099 the signal handler returning). Just single-step until the
5100 inferior leaves the trampoline (either by calling the handler
5106 /* If we're in the return path from a shared library trampoline,
5107 we want to proceed through the trampoline when stepping. */
5108 /* macro/2012-04-25: This needs to come before the subroutine
5109 call check below as on some targets return trampolines look
5110 like subroutine calls (MIPS16 return thunks). */
5111 if (gdbarch_in_solib_return_trampoline (gdbarch
,
5112 stop_pc
, ecs
->stop_func_name
)
5113 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
5115 /* Determine where this trampoline returns. */
5116 CORE_ADDR real_stop_pc
;
5118 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
5121 fprintf_unfiltered (gdb_stdlog
,
5122 "infrun: stepped into solib return tramp\n");
5124 /* Only proceed through if we know where it's going. */
5127 /* And put the step-breakpoint there and go until there. */
5128 struct symtab_and_line sr_sal
;
5130 init_sal (&sr_sal
); /* initialize to zeroes */
5131 sr_sal
.pc
= real_stop_pc
;
5132 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
5133 sr_sal
.pspace
= get_frame_program_space (frame
);
5135 /* Do not specify what the fp should be when we stop since
5136 on some machines the prologue is where the new fp value
5138 insert_step_resume_breakpoint_at_sal (gdbarch
,
5139 sr_sal
, null_frame_id
);
5141 /* Restart without fiddling with the step ranges or
5148 /* Check for subroutine calls. The check for the current frame
5149 equalling the step ID is not necessary - the check of the
5150 previous frame's ID is sufficient - but it is a common case and
5151 cheaper than checking the previous frame's ID.
5153 NOTE: frame_id_eq will never report two invalid frame IDs as
5154 being equal, so to get into this block, both the current and
5155 previous frame must have valid frame IDs. */
5156 /* The outer_frame_id check is a heuristic to detect stepping
5157 through startup code. If we step over an instruction which
5158 sets the stack pointer from an invalid value to a valid value,
5159 we may detect that as a subroutine call from the mythical
5160 "outermost" function. This could be fixed by marking
5161 outermost frames as !stack_p,code_p,special_p. Then the
5162 initial outermost frame, before sp was valid, would
5163 have code_addr == &_start. See the comment in frame_id_eq
5165 if (!frame_id_eq (get_stack_frame_id (frame
),
5166 ecs
->event_thread
->control
.step_stack_frame_id
)
5167 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
5168 ecs
->event_thread
->control
.step_stack_frame_id
)
5169 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
5171 || (ecs
->event_thread
->control
.step_start_function
5172 != find_pc_function (stop_pc
)))))
5174 CORE_ADDR real_stop_pc
;
5177 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
5179 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
5181 /* I presume that step_over_calls is only 0 when we're
5182 supposed to be stepping at the assembly language level
5183 ("stepi"). Just stop. */
5184 /* And this works the same backward as frontward. MVS */
5185 end_stepping_range (ecs
);
5189 /* Reverse stepping through solib trampolines. */
5191 if (execution_direction
== EXEC_REVERSE
5192 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
5193 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
5194 || (ecs
->stop_func_start
== 0
5195 && in_solib_dynsym_resolve_code (stop_pc
))))
5197 /* Any solib trampoline code can be handled in reverse
5198 by simply continuing to single-step. We have already
5199 executed the solib function (backwards), and a few
5200 steps will take us back through the trampoline to the
5206 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
5208 /* We're doing a "next".
5210 Normal (forward) execution: set a breakpoint at the
5211 callee's return address (the address at which the caller
5214 Reverse (backward) execution. set the step-resume
5215 breakpoint at the start of the function that we just
5216 stepped into (backwards), and continue to there. When we
5217 get there, we'll need to single-step back to the caller. */
5219 if (execution_direction
== EXEC_REVERSE
)
5221 /* If we're already at the start of the function, we've either
5222 just stepped backward into a single instruction function,
5223 or stepped back out of a signal handler to the first instruction
5224 of the function. Just keep going, which will single-step back
5226 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
5228 struct symtab_and_line sr_sal
;
5230 /* Normal function call return (static or dynamic). */
5232 sr_sal
.pc
= ecs
->stop_func_start
;
5233 sr_sal
.pspace
= get_frame_program_space (frame
);
5234 insert_step_resume_breakpoint_at_sal (gdbarch
,
5235 sr_sal
, null_frame_id
);
5239 insert_step_resume_breakpoint_at_caller (frame
);
5245 /* If we are in a function call trampoline (a stub between the
5246 calling routine and the real function), locate the real
5247 function. That's what tells us (a) whether we want to step
5248 into it at all, and (b) what prologue we want to run to the
5249 end of, if we do step into it. */
5250 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
5251 if (real_stop_pc
== 0)
5252 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
5253 if (real_stop_pc
!= 0)
5254 ecs
->stop_func_start
= real_stop_pc
;
5256 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
5258 struct symtab_and_line sr_sal
;
5261 sr_sal
.pc
= ecs
->stop_func_start
;
5262 sr_sal
.pspace
= get_frame_program_space (frame
);
5264 insert_step_resume_breakpoint_at_sal (gdbarch
,
5265 sr_sal
, null_frame_id
);
5270 /* If we have line number information for the function we are
5271 thinking of stepping into and the function isn't on the skip
5274 If there are several symtabs at that PC (e.g. with include
5275 files), just want to know whether *any* of them have line
5276 numbers. find_pc_line handles this. */
5278 struct symtab_and_line tmp_sal
;
5280 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
5281 if (tmp_sal
.line
!= 0
5282 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
5285 if (execution_direction
== EXEC_REVERSE
)
5286 handle_step_into_function_backward (gdbarch
, ecs
);
5288 handle_step_into_function (gdbarch
, ecs
);
5293 /* If we have no line number and the step-stop-if-no-debug is
5294 set, we stop the step so that the user has a chance to switch
5295 in assembly mode. */
5296 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
5297 && step_stop_if_no_debug
)
5299 end_stepping_range (ecs
);
5303 if (execution_direction
== EXEC_REVERSE
)
5305 /* If we're already at the start of the function, we've either just
5306 stepped backward into a single instruction function without line
5307 number info, or stepped back out of a signal handler to the first
5308 instruction of the function without line number info. Just keep
5309 going, which will single-step back to the caller. */
5310 if (ecs
->stop_func_start
!= stop_pc
)
5312 /* Set a breakpoint at callee's start address.
5313 From there we can step once and be back in the caller. */
5314 struct symtab_and_line sr_sal
;
5317 sr_sal
.pc
= ecs
->stop_func_start
;
5318 sr_sal
.pspace
= get_frame_program_space (frame
);
5319 insert_step_resume_breakpoint_at_sal (gdbarch
,
5320 sr_sal
, null_frame_id
);
5324 /* Set a breakpoint at callee's return address (the address
5325 at which the caller will resume). */
5326 insert_step_resume_breakpoint_at_caller (frame
);
5332 /* Reverse stepping through solib trampolines. */
5334 if (execution_direction
== EXEC_REVERSE
5335 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
5337 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
5338 || (ecs
->stop_func_start
== 0
5339 && in_solib_dynsym_resolve_code (stop_pc
)))
5341 /* Any solib trampoline code can be handled in reverse
5342 by simply continuing to single-step. We have already
5343 executed the solib function (backwards), and a few
5344 steps will take us back through the trampoline to the
5349 else if (in_solib_dynsym_resolve_code (stop_pc
))
5351 /* Stepped backward into the solib dynsym resolver.
5352 Set a breakpoint at its start and continue, then
5353 one more step will take us out. */
5354 struct symtab_and_line sr_sal
;
5357 sr_sal
.pc
= ecs
->stop_func_start
;
5358 sr_sal
.pspace
= get_frame_program_space (frame
);
5359 insert_step_resume_breakpoint_at_sal (gdbarch
,
5360 sr_sal
, null_frame_id
);
5366 stop_pc_sal
= find_pc_line (stop_pc
, 0);
5368 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5369 the trampoline processing logic, however, there are some trampolines
5370 that have no names, so we should do trampoline handling first. */
5371 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
5372 && ecs
->stop_func_name
== NULL
5373 && stop_pc_sal
.line
== 0)
5376 fprintf_unfiltered (gdb_stdlog
,
5377 "infrun: stepped into undebuggable function\n");
5379 /* The inferior just stepped into, or returned to, an
5380 undebuggable function (where there is no debugging information
5381 and no line number corresponding to the address where the
5382 inferior stopped). Since we want to skip this kind of code,
5383 we keep going until the inferior returns from this
5384 function - unless the user has asked us not to (via
5385 set step-mode) or we no longer know how to get back
5386 to the call site. */
5387 if (step_stop_if_no_debug
5388 || !frame_id_p (frame_unwind_caller_id (frame
)))
5390 /* If we have no line number and the step-stop-if-no-debug
5391 is set, we stop the step so that the user has a chance to
5392 switch in assembly mode. */
5393 end_stepping_range (ecs
);
5398 /* Set a breakpoint at callee's return address (the address
5399 at which the caller will resume). */
5400 insert_step_resume_breakpoint_at_caller (frame
);
5406 if (ecs
->event_thread
->control
.step_range_end
== 1)
5408 /* It is stepi or nexti. We always want to stop stepping after
5411 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
5412 end_stepping_range (ecs
);
5416 if (stop_pc_sal
.line
== 0)
5418 /* We have no line number information. That means to stop
5419 stepping (does this always happen right after one instruction,
5420 when we do "s" in a function with no line numbers,
5421 or can this happen as a result of a return or longjmp?). */
5423 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
5424 end_stepping_range (ecs
);
5428 /* Look for "calls" to inlined functions, part one. If the inline
5429 frame machinery detected some skipped call sites, we have entered
5430 a new inline function. */
5432 if (frame_id_eq (get_frame_id (get_current_frame ()),
5433 ecs
->event_thread
->control
.step_frame_id
)
5434 && inline_skipped_frames (ecs
->ptid
))
5436 struct symtab_and_line call_sal
;
5439 fprintf_unfiltered (gdb_stdlog
,
5440 "infrun: stepped into inlined function\n");
5442 find_frame_sal (get_current_frame (), &call_sal
);
5444 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
5446 /* For "step", we're going to stop. But if the call site
5447 for this inlined function is on the same source line as
5448 we were previously stepping, go down into the function
5449 first. Otherwise stop at the call site. */
5451 if (call_sal
.line
== ecs
->event_thread
->current_line
5452 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
5453 step_into_inline_frame (ecs
->ptid
);
5455 end_stepping_range (ecs
);
5460 /* For "next", we should stop at the call site if it is on a
5461 different source line. Otherwise continue through the
5462 inlined function. */
5463 if (call_sal
.line
== ecs
->event_thread
->current_line
5464 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
5467 end_stepping_range (ecs
);
5472 /* Look for "calls" to inlined functions, part two. If we are still
5473 in the same real function we were stepping through, but we have
5474 to go further up to find the exact frame ID, we are stepping
5475 through a more inlined call beyond its call site. */
5477 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5478 && !frame_id_eq (get_frame_id (get_current_frame ()),
5479 ecs
->event_thread
->control
.step_frame_id
)
5480 && stepped_in_from (get_current_frame (),
5481 ecs
->event_thread
->control
.step_frame_id
))
5484 fprintf_unfiltered (gdb_stdlog
,
5485 "infrun: stepping through inlined function\n");
5487 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
5490 end_stepping_range (ecs
);
5494 if ((stop_pc
== stop_pc_sal
.pc
)
5495 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
5496 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
5498 /* We are at the start of a different line. So stop. Note that
5499 we don't stop if we step into the middle of a different line.
5500 That is said to make things like for (;;) statements work
5503 fprintf_unfiltered (gdb_stdlog
,
5504 "infrun: stepped to a different line\n");
5505 end_stepping_range (ecs
);
5509 /* We aren't done stepping.
5511 Optimize by setting the stepping range to the line.
5512 (We might not be in the original line, but if we entered a
5513 new line in mid-statement, we continue stepping. This makes
5514 things like for(;;) statements work better.) */
5516 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
5517 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
5518 ecs
->event_thread
->control
.may_range_step
= 1;
5519 set_step_info (frame
, stop_pc_sal
);
5522 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
5526 /* In all-stop mode, if we're currently stepping but have stopped in
5527 some other thread, we may need to switch back to the stepped
5528 thread. Returns true we set the inferior running, false if we left
5529 it stopped (and the event needs further processing). */
5532 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
5536 struct thread_info
*tp
;
5537 struct thread_info
*stepping_thread
;
5538 struct thread_info
*step_over
;
5540 /* If any thread is blocked on some internal breakpoint, and we
5541 simply need to step over that breakpoint to get it going
5542 again, do that first. */
5544 /* However, if we see an event for the stepping thread, then we
5545 know all other threads have been moved past their breakpoints
5546 already. Let the caller check whether the step is finished,
5547 etc., before deciding to move it past a breakpoint. */
5548 if (ecs
->event_thread
->control
.step_range_end
!= 0)
5551 /* Check if the current thread is blocked on an incomplete
5552 step-over, interrupted by a random signal. */
5553 if (ecs
->event_thread
->control
.trap_expected
5554 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
5558 fprintf_unfiltered (gdb_stdlog
,
5559 "infrun: need to finish step-over of [%s]\n",
5560 target_pid_to_str (ecs
->event_thread
->ptid
));
5566 /* Check if the current thread is blocked by a single-step
5567 breakpoint of another thread. */
5568 if (ecs
->hit_singlestep_breakpoint
)
5572 fprintf_unfiltered (gdb_stdlog
,
5573 "infrun: need to step [%s] over single-step "
5575 target_pid_to_str (ecs
->ptid
));
5581 /* Otherwise, we no longer expect a trap in the current thread.
5582 Clear the trap_expected flag before switching back -- this is
5583 what keep_going does as well, if we call it. */
5584 ecs
->event_thread
->control
.trap_expected
= 0;
5586 /* Likewise, clear the signal if it should not be passed. */
5587 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
5588 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5590 /* If scheduler locking applies even if not stepping, there's no
5591 need to walk over threads. Above we've checked whether the
5592 current thread is stepping. If some other thread not the
5593 event thread is stepping, then it must be that scheduler
5594 locking is not in effect. */
5595 if (schedlock_applies (0))
5598 /* Look for the stepping/nexting thread, and check if any other
5599 thread other than the stepping thread needs to start a
5600 step-over. Do all step-overs before actually proceeding with
5602 stepping_thread
= NULL
;
5604 ALL_NON_EXITED_THREADS (tp
)
5606 /* Ignore threads of processes we're not resuming. */
5608 && ptid_get_pid (tp
->ptid
) != ptid_get_pid (inferior_ptid
))
5611 /* When stepping over a breakpoint, we lock all threads
5612 except the one that needs to move past the breakpoint.
5613 If a non-event thread has this set, the "incomplete
5614 step-over" check above should have caught it earlier. */
5615 gdb_assert (!tp
->control
.trap_expected
);
5617 /* Did we find the stepping thread? */
5618 if (tp
->control
.step_range_end
)
5620 /* Yep. There should only one though. */
5621 gdb_assert (stepping_thread
== NULL
);
5623 /* The event thread is handled at the top, before we
5625 gdb_assert (tp
!= ecs
->event_thread
);
5627 /* If some thread other than the event thread is
5628 stepping, then scheduler locking can't be in effect,
5629 otherwise we wouldn't have resumed the current event
5630 thread in the first place. */
5631 gdb_assert (!schedlock_applies (currently_stepping (tp
)));
5633 stepping_thread
= tp
;
5635 else if (thread_still_needs_step_over (tp
))
5639 /* At the top we've returned early if the event thread
5640 is stepping. If some other thread not the event
5641 thread is stepping, then scheduler locking can't be
5642 in effect, and we can resume this thread. No need to
5643 keep looking for the stepping thread then. */
5648 if (step_over
!= NULL
)
5653 fprintf_unfiltered (gdb_stdlog
,
5654 "infrun: need to step-over [%s]\n",
5655 target_pid_to_str (tp
->ptid
));
5658 /* Only the stepping thread should have this set. */
5659 gdb_assert (tp
->control
.step_range_end
== 0);
5661 ecs
->ptid
= tp
->ptid
;
5662 ecs
->event_thread
= tp
;
5663 switch_to_thread (ecs
->ptid
);
5668 if (stepping_thread
!= NULL
)
5670 struct frame_info
*frame
;
5671 struct gdbarch
*gdbarch
;
5673 tp
= stepping_thread
;
5675 /* If the stepping thread exited, then don't try to switch
5676 back and resume it, which could fail in several different
5677 ways depending on the target. Instead, just keep going.
5679 We can find a stepping dead thread in the thread list in
5682 - The target supports thread exit events, and when the
5683 target tries to delete the thread from the thread list,
5684 inferior_ptid pointed at the exiting thread. In such
5685 case, calling delete_thread does not really remove the
5686 thread from the list; instead, the thread is left listed,
5687 with 'exited' state.
5689 - The target's debug interface does not support thread
5690 exit events, and so we have no idea whatsoever if the
5691 previously stepping thread is still alive. For that
5692 reason, we need to synchronously query the target
5694 if (is_exited (tp
->ptid
)
5695 || !target_thread_alive (tp
->ptid
))
5698 fprintf_unfiltered (gdb_stdlog
,
5699 "infrun: not switching back to "
5700 "stepped thread, it has vanished\n");
5702 delete_thread (tp
->ptid
);
5708 fprintf_unfiltered (gdb_stdlog
,
5709 "infrun: switching back to stepped thread\n");
5711 ecs
->event_thread
= tp
;
5712 ecs
->ptid
= tp
->ptid
;
5713 context_switch (ecs
->ptid
);
5715 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5716 frame
= get_current_frame ();
5717 gdbarch
= get_frame_arch (frame
);
5719 /* If the PC of the thread we were trying to single-step has
5720 changed, then that thread has trapped or been signaled,
5721 but the event has not been reported to GDB yet. Re-poll
5722 the target looking for this particular thread's event
5723 (i.e. temporarily enable schedlock) by:
5725 - setting a break at the current PC
5726 - resuming that particular thread, only (by setting
5729 This prevents us continuously moving the single-step
5730 breakpoint forward, one instruction at a time,
5733 if (stop_pc
!= tp
->prev_pc
)
5736 fprintf_unfiltered (gdb_stdlog
,
5737 "infrun: expected thread advanced also\n");
5739 /* Clear the info of the previous step-over, as it's no
5740 longer valid. It's what keep_going would do too, if
5741 we called it. Must do this before trying to insert
5742 the sss breakpoint, otherwise if we were previously
5743 trying to step over this exact address in another
5744 thread, the breakpoint ends up not installed. */
5745 clear_step_over_info ();
5747 insert_single_step_breakpoint (get_frame_arch (frame
),
5748 get_frame_address_space (frame
),
5750 ecs
->event_thread
->control
.trap_expected
= 1;
5752 resume (0, GDB_SIGNAL_0
);
5753 prepare_to_wait (ecs
);
5758 fprintf_unfiltered (gdb_stdlog
,
5759 "infrun: expected thread still "
5760 "hasn't advanced\n");
5770 /* Is thread TP in the middle of single-stepping? */
5773 currently_stepping (struct thread_info
*tp
)
5775 return ((tp
->control
.step_range_end
5776 && tp
->control
.step_resume_breakpoint
== NULL
)
5777 || tp
->control
.trap_expected
5778 || tp
->stepped_breakpoint
5779 || bpstat_should_step ());
5782 /* Inferior has stepped into a subroutine call with source code that
5783 we should not step over. Do step to the first line of code in
5787 handle_step_into_function (struct gdbarch
*gdbarch
,
5788 struct execution_control_state
*ecs
)
5790 struct compunit_symtab
*cust
;
5791 struct symtab_and_line stop_func_sal
, sr_sal
;
5793 fill_in_stop_func (gdbarch
, ecs
);
5795 cust
= find_pc_compunit_symtab (stop_pc
);
5796 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
5797 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
5798 ecs
->stop_func_start
);
5800 stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
5801 /* Use the step_resume_break to step until the end of the prologue,
5802 even if that involves jumps (as it seems to on the vax under
5804 /* If the prologue ends in the middle of a source line, continue to
5805 the end of that source line (if it is still within the function).
5806 Otherwise, just go to end of prologue. */
5807 if (stop_func_sal
.end
5808 && stop_func_sal
.pc
!= ecs
->stop_func_start
5809 && stop_func_sal
.end
< ecs
->stop_func_end
)
5810 ecs
->stop_func_start
= stop_func_sal
.end
;
5812 /* Architectures which require breakpoint adjustment might not be able
5813 to place a breakpoint at the computed address. If so, the test
5814 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5815 ecs->stop_func_start to an address at which a breakpoint may be
5816 legitimately placed.
5818 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5819 made, GDB will enter an infinite loop when stepping through
5820 optimized code consisting of VLIW instructions which contain
5821 subinstructions corresponding to different source lines. On
5822 FR-V, it's not permitted to place a breakpoint on any but the
5823 first subinstruction of a VLIW instruction. When a breakpoint is
5824 set, GDB will adjust the breakpoint address to the beginning of
5825 the VLIW instruction. Thus, we need to make the corresponding
5826 adjustment here when computing the stop address. */
5828 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
5830 ecs
->stop_func_start
5831 = gdbarch_adjust_breakpoint_address (gdbarch
,
5832 ecs
->stop_func_start
);
5835 if (ecs
->stop_func_start
== stop_pc
)
5837 /* We are already there: stop now. */
5838 end_stepping_range (ecs
);
5843 /* Put the step-breakpoint there and go until there. */
5844 init_sal (&sr_sal
); /* initialize to zeroes */
5845 sr_sal
.pc
= ecs
->stop_func_start
;
5846 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
5847 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
5849 /* Do not specify what the fp should be when we stop since on
5850 some machines the prologue is where the new fp value is
5852 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
5854 /* And make sure stepping stops right away then. */
5855 ecs
->event_thread
->control
.step_range_end
5856 = ecs
->event_thread
->control
.step_range_start
;
5861 /* Inferior has stepped backward into a subroutine call with source
5862 code that we should not step over. Do step to the beginning of the
5863 last line of code in it. */
5866 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
5867 struct execution_control_state
*ecs
)
5869 struct compunit_symtab
*cust
;
5870 struct symtab_and_line stop_func_sal
;
5872 fill_in_stop_func (gdbarch
, ecs
);
5874 cust
= find_pc_compunit_symtab (stop_pc
);
5875 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
5876 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
5877 ecs
->stop_func_start
);
5879 stop_func_sal
= find_pc_line (stop_pc
, 0);
5881 /* OK, we're just going to keep stepping here. */
5882 if (stop_func_sal
.pc
== stop_pc
)
5884 /* We're there already. Just stop stepping now. */
5885 end_stepping_range (ecs
);
5889 /* Else just reset the step range and keep going.
5890 No step-resume breakpoint, they don't work for
5891 epilogues, which can have multiple entry paths. */
5892 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
5893 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
5899 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5900 This is used to both functions and to skip over code. */
5903 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
5904 struct symtab_and_line sr_sal
,
5905 struct frame_id sr_id
,
5906 enum bptype sr_type
)
5908 /* There should never be more than one step-resume or longjmp-resume
5909 breakpoint per thread, so we should never be setting a new
5910 step_resume_breakpoint when one is already active. */
5911 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
5912 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
5915 fprintf_unfiltered (gdb_stdlog
,
5916 "infrun: inserting step-resume breakpoint at %s\n",
5917 paddress (gdbarch
, sr_sal
.pc
));
5919 inferior_thread ()->control
.step_resume_breakpoint
5920 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
);
5924 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
5925 struct symtab_and_line sr_sal
,
5926 struct frame_id sr_id
)
5928 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
5933 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5934 This is used to skip a potential signal handler.
5936 This is called with the interrupted function's frame. The signal
5937 handler, when it returns, will resume the interrupted function at
5941 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
5943 struct symtab_and_line sr_sal
;
5944 struct gdbarch
*gdbarch
;
5946 gdb_assert (return_frame
!= NULL
);
5947 init_sal (&sr_sal
); /* initialize to zeros */
5949 gdbarch
= get_frame_arch (return_frame
);
5950 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
5951 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
5952 sr_sal
.pspace
= get_frame_program_space (return_frame
);
5954 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
5955 get_stack_frame_id (return_frame
),
5959 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5960 is used to skip a function after stepping into it (for "next" or if
5961 the called function has no debugging information).
5963 The current function has almost always been reached by single
5964 stepping a call or return instruction. NEXT_FRAME belongs to the
5965 current function, and the breakpoint will be set at the caller's
5968 This is a separate function rather than reusing
5969 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5970 get_prev_frame, which may stop prematurely (see the implementation
5971 of frame_unwind_caller_id for an example). */
5974 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
5976 struct symtab_and_line sr_sal
;
5977 struct gdbarch
*gdbarch
;
5979 /* We shouldn't have gotten here if we don't know where the call site
5981 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
5983 init_sal (&sr_sal
); /* initialize to zeros */
5985 gdbarch
= frame_unwind_caller_arch (next_frame
);
5986 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
5987 frame_unwind_caller_pc (next_frame
));
5988 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
5989 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
5991 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
5992 frame_unwind_caller_id (next_frame
));
5995 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5996 new breakpoint at the target of a jmp_buf. The handling of
5997 longjmp-resume uses the same mechanisms used for handling
5998 "step-resume" breakpoints. */
6001 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
6003 /* There should never be more than one longjmp-resume breakpoint per
6004 thread, so we should never be setting a new
6005 longjmp_resume_breakpoint when one is already active. */
6006 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
6009 fprintf_unfiltered (gdb_stdlog
,
6010 "infrun: inserting longjmp-resume breakpoint at %s\n",
6011 paddress (gdbarch
, pc
));
6013 inferior_thread ()->control
.exception_resume_breakpoint
=
6014 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
);
6017 /* Insert an exception resume breakpoint. TP is the thread throwing
6018 the exception. The block B is the block of the unwinder debug hook
6019 function. FRAME is the frame corresponding to the call to this
6020 function. SYM is the symbol of the function argument holding the
6021 target PC of the exception. */
6024 insert_exception_resume_breakpoint (struct thread_info
*tp
,
6025 const struct block
*b
,
6026 struct frame_info
*frame
,
6031 struct symbol
*vsym
;
6032 struct value
*value
;
6034 struct breakpoint
*bp
;
6036 vsym
= lookup_symbol (SYMBOL_LINKAGE_NAME (sym
), b
, VAR_DOMAIN
, NULL
);
6037 value
= read_var_value (vsym
, frame
);
6038 /* If the value was optimized out, revert to the old behavior. */
6039 if (! value_optimized_out (value
))
6041 handler
= value_as_address (value
);
6044 fprintf_unfiltered (gdb_stdlog
,
6045 "infrun: exception resume at %lx\n",
6046 (unsigned long) handler
);
6048 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
6049 handler
, bp_exception_resume
);
6051 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
6054 bp
->thread
= tp
->num
;
6055 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
6058 CATCH (e
, RETURN_MASK_ERROR
)
6060 /* We want to ignore errors here. */
6065 /* A helper for check_exception_resume that sets an
6066 exception-breakpoint based on a SystemTap probe. */
6069 insert_exception_resume_from_probe (struct thread_info
*tp
,
6070 const struct bound_probe
*probe
,
6071 struct frame_info
*frame
)
6073 struct value
*arg_value
;
6075 struct breakpoint
*bp
;
6077 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
6081 handler
= value_as_address (arg_value
);
6084 fprintf_unfiltered (gdb_stdlog
,
6085 "infrun: exception resume at %s\n",
6086 paddress (get_objfile_arch (probe
->objfile
),
6089 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
6090 handler
, bp_exception_resume
);
6091 bp
->thread
= tp
->num
;
6092 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
6095 /* This is called when an exception has been intercepted. Check to
6096 see whether the exception's destination is of interest, and if so,
6097 set an exception resume breakpoint there. */
6100 check_exception_resume (struct execution_control_state
*ecs
,
6101 struct frame_info
*frame
)
6103 struct bound_probe probe
;
6104 struct symbol
*func
;
6106 /* First see if this exception unwinding breakpoint was set via a
6107 SystemTap probe point. If so, the probe has two arguments: the
6108 CFA and the HANDLER. We ignore the CFA, extract the handler, and
6109 set a breakpoint there. */
6110 probe
= find_probe_by_pc (get_frame_pc (frame
));
6113 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
6117 func
= get_frame_function (frame
);
6123 const struct block
*b
;
6124 struct block_iterator iter
;
6128 /* The exception breakpoint is a thread-specific breakpoint on
6129 the unwinder's debug hook, declared as:
6131 void _Unwind_DebugHook (void *cfa, void *handler);
6133 The CFA argument indicates the frame to which control is
6134 about to be transferred. HANDLER is the destination PC.
6136 We ignore the CFA and set a temporary breakpoint at HANDLER.
6137 This is not extremely efficient but it avoids issues in gdb
6138 with computing the DWARF CFA, and it also works even in weird
6139 cases such as throwing an exception from inside a signal
6142 b
= SYMBOL_BLOCK_VALUE (func
);
6143 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
6145 if (!SYMBOL_IS_ARGUMENT (sym
))
6152 insert_exception_resume_breakpoint (ecs
->event_thread
,
6158 CATCH (e
, RETURN_MASK_ERROR
)
6165 stop_waiting (struct execution_control_state
*ecs
)
6168 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
6170 clear_step_over_info ();
6172 /* Let callers know we don't want to wait for the inferior anymore. */
6173 ecs
->wait_some_more
= 0;
6176 /* Called when we should continue running the inferior, because the
6177 current event doesn't cause a user visible stop. This does the
6178 resuming part; waiting for the next event is done elsewhere. */
6181 keep_going (struct execution_control_state
*ecs
)
6183 /* Make sure normal_stop is called if we get a QUIT handled before
6185 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
6187 /* Save the pc before execution, to compare with pc after stop. */
6188 ecs
->event_thread
->prev_pc
6189 = regcache_read_pc (get_thread_regcache (ecs
->ptid
));
6191 if (ecs
->event_thread
->control
.trap_expected
6192 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
6194 /* We haven't yet gotten our trap, and either: intercepted a
6195 non-signal event (e.g., a fork); or took a signal which we
6196 are supposed to pass through to the inferior. Simply
6198 discard_cleanups (old_cleanups
);
6199 resume (currently_stepping (ecs
->event_thread
),
6200 ecs
->event_thread
->suspend
.stop_signal
);
6204 struct regcache
*regcache
= get_current_regcache ();
6208 /* Either the trap was not expected, but we are continuing
6209 anyway (if we got a signal, the user asked it be passed to
6212 We got our expected trap, but decided we should resume from
6215 We're going to run this baby now!
6217 Note that insert_breakpoints won't try to re-insert
6218 already inserted breakpoints. Therefore, we don't
6219 care if breakpoints were already inserted, or not. */
6221 /* If we need to step over a breakpoint, and we're not using
6222 displaced stepping to do so, insert all breakpoints
6223 (watchpoints, etc.) but the one we're stepping over, step one
6224 instruction, and then re-insert the breakpoint when that step
6227 remove_bp
= (ecs
->hit_singlestep_breakpoint
6228 || thread_still_needs_step_over (ecs
->event_thread
));
6229 remove_wps
= (ecs
->event_thread
->stepping_over_watchpoint
6230 && !target_have_steppable_watchpoint
);
6232 if (remove_bp
&& !use_displaced_stepping (get_regcache_arch (regcache
)))
6234 set_step_over_info (get_regcache_aspace (regcache
),
6235 regcache_read_pc (regcache
), remove_wps
);
6237 else if (remove_wps
)
6238 set_step_over_info (NULL
, 0, remove_wps
);
6240 clear_step_over_info ();
6242 /* Stop stepping if inserting breakpoints fails. */
6245 insert_breakpoints ();
6247 CATCH (e
, RETURN_MASK_ERROR
)
6249 exception_print (gdb_stderr
, e
);
6255 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
6257 /* Do not deliver GDB_SIGNAL_TRAP (except when the user
6258 explicitly specifies that such a signal should be delivered
6259 to the target program). Typically, that would occur when a
6260 user is debugging a target monitor on a simulator: the target
6261 monitor sets a breakpoint; the simulator encounters this
6262 breakpoint and halts the simulation handing control to GDB;
6263 GDB, noting that the stop address doesn't map to any known
6264 breakpoint, returns control back to the simulator; the
6265 simulator then delivers the hardware equivalent of a
6266 GDB_SIGNAL_TRAP to the program being debugged. */
6267 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6268 && !signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
6269 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6271 discard_cleanups (old_cleanups
);
6272 resume (currently_stepping (ecs
->event_thread
),
6273 ecs
->event_thread
->suspend
.stop_signal
);
6276 prepare_to_wait (ecs
);
6279 /* This function normally comes after a resume, before
6280 handle_inferior_event exits. It takes care of any last bits of
6281 housekeeping, and sets the all-important wait_some_more flag. */
6284 prepare_to_wait (struct execution_control_state
*ecs
)
6287 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
6289 /* This is the old end of the while loop. Let everybody know we
6290 want to wait for the inferior some more and get called again
6292 ecs
->wait_some_more
= 1;
6295 /* We are done with the step range of a step/next/si/ni command.
6296 Called once for each n of a "step n" operation. */
6299 end_stepping_range (struct execution_control_state
*ecs
)
6301 ecs
->event_thread
->control
.stop_step
= 1;
6305 /* Several print_*_reason functions to print why the inferior has stopped.
6306 We always print something when the inferior exits, or receives a signal.
6307 The rest of the cases are dealt with later on in normal_stop and
6308 print_it_typical. Ideally there should be a call to one of these
6309 print_*_reason functions functions from handle_inferior_event each time
6310 stop_waiting is called.
6312 Note that we don't call these directly, instead we delegate that to
6313 the interpreters, through observers. Interpreters then call these
6314 with whatever uiout is right. */
6317 print_end_stepping_range_reason (struct ui_out
*uiout
)
6319 /* For CLI-like interpreters, print nothing. */
6321 if (ui_out_is_mi_like_p (uiout
))
6323 ui_out_field_string (uiout
, "reason",
6324 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
6329 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
6331 annotate_signalled ();
6332 if (ui_out_is_mi_like_p (uiout
))
6334 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
6335 ui_out_text (uiout
, "\nProgram terminated with signal ");
6336 annotate_signal_name ();
6337 ui_out_field_string (uiout
, "signal-name",
6338 gdb_signal_to_name (siggnal
));
6339 annotate_signal_name_end ();
6340 ui_out_text (uiout
, ", ");
6341 annotate_signal_string ();
6342 ui_out_field_string (uiout
, "signal-meaning",
6343 gdb_signal_to_string (siggnal
));
6344 annotate_signal_string_end ();
6345 ui_out_text (uiout
, ".\n");
6346 ui_out_text (uiout
, "The program no longer exists.\n");
6350 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
6352 struct inferior
*inf
= current_inferior ();
6353 const char *pidstr
= target_pid_to_str (pid_to_ptid (inf
->pid
));
6355 annotate_exited (exitstatus
);
6358 if (ui_out_is_mi_like_p (uiout
))
6359 ui_out_field_string (uiout
, "reason",
6360 async_reason_lookup (EXEC_ASYNC_EXITED
));
6361 ui_out_text (uiout
, "[Inferior ");
6362 ui_out_text (uiout
, plongest (inf
->num
));
6363 ui_out_text (uiout
, " (");
6364 ui_out_text (uiout
, pidstr
);
6365 ui_out_text (uiout
, ") exited with code ");
6366 ui_out_field_fmt (uiout
, "exit-code", "0%o", (unsigned int) exitstatus
);
6367 ui_out_text (uiout
, "]\n");
6371 if (ui_out_is_mi_like_p (uiout
))
6373 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
6374 ui_out_text (uiout
, "[Inferior ");
6375 ui_out_text (uiout
, plongest (inf
->num
));
6376 ui_out_text (uiout
, " (");
6377 ui_out_text (uiout
, pidstr
);
6378 ui_out_text (uiout
, ") exited normally]\n");
6383 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
6387 if (siggnal
== GDB_SIGNAL_0
&& !ui_out_is_mi_like_p (uiout
))
6389 struct thread_info
*t
= inferior_thread ();
6391 ui_out_text (uiout
, "\n[");
6392 ui_out_field_string (uiout
, "thread-name",
6393 target_pid_to_str (t
->ptid
));
6394 ui_out_field_fmt (uiout
, "thread-id", "] #%d", t
->num
);
6395 ui_out_text (uiout
, " stopped");
6399 ui_out_text (uiout
, "\nProgram received signal ");
6400 annotate_signal_name ();
6401 if (ui_out_is_mi_like_p (uiout
))
6403 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
6404 ui_out_field_string (uiout
, "signal-name",
6405 gdb_signal_to_name (siggnal
));
6406 annotate_signal_name_end ();
6407 ui_out_text (uiout
, ", ");
6408 annotate_signal_string ();
6409 ui_out_field_string (uiout
, "signal-meaning",
6410 gdb_signal_to_string (siggnal
));
6411 annotate_signal_string_end ();
6413 ui_out_text (uiout
, ".\n");
6417 print_no_history_reason (struct ui_out
*uiout
)
6419 ui_out_text (uiout
, "\nNo more reverse-execution history.\n");
6422 /* Print current location without a level number, if we have changed
6423 functions or hit a breakpoint. Print source line if we have one.
6424 bpstat_print contains the logic deciding in detail what to print,
6425 based on the event(s) that just occurred. */
6428 print_stop_event (struct target_waitstatus
*ws
)
6432 int do_frame_printing
= 1;
6433 struct thread_info
*tp
= inferior_thread ();
6435 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
6439 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
6440 should) carry around the function and does (or should) use
6441 that when doing a frame comparison. */
6442 if (tp
->control
.stop_step
6443 && frame_id_eq (tp
->control
.step_frame_id
,
6444 get_frame_id (get_current_frame ()))
6445 && tp
->control
.step_start_function
== find_pc_function (stop_pc
))
6447 /* Finished step, just print source line. */
6448 source_flag
= SRC_LINE
;
6452 /* Print location and source line. */
6453 source_flag
= SRC_AND_LOC
;
6456 case PRINT_SRC_AND_LOC
:
6457 /* Print location and source line. */
6458 source_flag
= SRC_AND_LOC
;
6460 case PRINT_SRC_ONLY
:
6461 source_flag
= SRC_LINE
;
6464 /* Something bogus. */
6465 source_flag
= SRC_LINE
;
6466 do_frame_printing
= 0;
6469 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
6472 /* The behavior of this routine with respect to the source
6474 SRC_LINE: Print only source line
6475 LOCATION: Print only location
6476 SRC_AND_LOC: Print location and source line. */
6477 if (do_frame_printing
)
6478 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
6480 /* Display the auto-display expressions. */
6484 /* Here to return control to GDB when the inferior stops for real.
6485 Print appropriate messages, remove breakpoints, give terminal our modes.
6487 STOP_PRINT_FRAME nonzero means print the executing frame
6488 (pc, function, args, file, line number and line text).
6489 BREAKPOINTS_FAILED nonzero means stop was due to error
6490 attempting to insert breakpoints. */
6495 struct target_waitstatus last
;
6497 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
6499 get_last_target_status (&last_ptid
, &last
);
6501 /* If an exception is thrown from this point on, make sure to
6502 propagate GDB's knowledge of the executing state to the
6503 frontend/user running state. A QUIT is an easy exception to see
6504 here, so do this before any filtered output. */
6506 make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
6507 else if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
6508 && last
.kind
!= TARGET_WAITKIND_EXITED
6509 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
6510 make_cleanup (finish_thread_state_cleanup
, &inferior_ptid
);
6512 /* As we're presenting a stop, and potentially removing breakpoints,
6513 update the thread list so we can tell whether there are threads
6514 running on the target. With target remote, for example, we can
6515 only learn about new threads when we explicitly update the thread
6516 list. Do this before notifying the interpreters about signal
6517 stops, end of stepping ranges, etc., so that the "new thread"
6518 output is emitted before e.g., "Program received signal FOO",
6519 instead of after. */
6520 update_thread_list ();
6522 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
6523 observer_notify_signal_received (inferior_thread ()->suspend
.stop_signal
);
6525 /* As with the notification of thread events, we want to delay
6526 notifying the user that we've switched thread context until
6527 the inferior actually stops.
6529 There's no point in saying anything if the inferior has exited.
6530 Note that SIGNALLED here means "exited with a signal", not
6531 "received a signal".
6533 Also skip saying anything in non-stop mode. In that mode, as we
6534 don't want GDB to switch threads behind the user's back, to avoid
6535 races where the user is typing a command to apply to thread x,
6536 but GDB switches to thread y before the user finishes entering
6537 the command, fetch_inferior_event installs a cleanup to restore
6538 the current thread back to the thread the user had selected right
6539 after this event is handled, so we're not really switching, only
6540 informing of a stop. */
6542 && !ptid_equal (previous_inferior_ptid
, inferior_ptid
)
6543 && target_has_execution
6544 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
6545 && last
.kind
!= TARGET_WAITKIND_EXITED
6546 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
6548 target_terminal_ours_for_output ();
6549 printf_filtered (_("[Switching to %s]\n"),
6550 target_pid_to_str (inferior_ptid
));
6551 annotate_thread_changed ();
6552 previous_inferior_ptid
= inferior_ptid
;
6555 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
6557 gdb_assert (sync_execution
|| !target_can_async_p ());
6559 target_terminal_ours_for_output ();
6560 printf_filtered (_("No unwaited-for children left.\n"));
6563 /* Note: this depends on the update_thread_list call above. */
6564 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
6566 if (remove_breakpoints ())
6568 target_terminal_ours_for_output ();
6569 printf_filtered (_("Cannot remove breakpoints because "
6570 "program is no longer writable.\nFurther "
6571 "execution is probably impossible.\n"));
6575 /* If an auto-display called a function and that got a signal,
6576 delete that auto-display to avoid an infinite recursion. */
6578 if (stopped_by_random_signal
)
6579 disable_current_display ();
6581 /* Notify observers if we finished a "step"-like command, etc. */
6582 if (target_has_execution
6583 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
6584 && last
.kind
!= TARGET_WAITKIND_EXITED
6585 && inferior_thread ()->control
.stop_step
)
6587 /* But not if in the middle of doing a "step n" operation for
6589 if (inferior_thread ()->step_multi
)
6592 observer_notify_end_stepping_range ();
6595 target_terminal_ours ();
6596 async_enable_stdin ();
6598 /* Set the current source location. This will also happen if we
6599 display the frame below, but the current SAL will be incorrect
6600 during a user hook-stop function. */
6601 if (has_stack_frames () && !stop_stack_dummy
)
6602 set_current_sal_from_frame (get_current_frame ());
6604 /* Let the user/frontend see the threads as stopped, but do nothing
6605 if the thread was running an infcall. We may be e.g., evaluating
6606 a breakpoint condition. In that case, the thread had state
6607 THREAD_RUNNING before the infcall, and shall remain set to
6608 running, all without informing the user/frontend about state
6609 transition changes. If this is actually a call command, then the
6610 thread was originally already stopped, so there's no state to
6612 if (target_has_execution
&& inferior_thread ()->control
.in_infcall
)
6613 discard_cleanups (old_chain
);
6615 do_cleanups (old_chain
);
6617 /* Look up the hook_stop and run it (CLI internally handles problem
6618 of stop_command's pre-hook not existing). */
6620 catch_errors (hook_stop_stub
, stop_command
,
6621 "Error while running hook_stop:\n", RETURN_MASK_ALL
);
6623 if (!has_stack_frames ())
6626 if (last
.kind
== TARGET_WAITKIND_SIGNALLED
6627 || last
.kind
== TARGET_WAITKIND_EXITED
)
6630 /* Select innermost stack frame - i.e., current frame is frame 0,
6631 and current location is based on that.
6632 Don't do this on return from a stack dummy routine,
6633 or if the program has exited. */
6635 if (!stop_stack_dummy
)
6637 select_frame (get_current_frame ());
6639 /* If --batch-silent is enabled then there's no need to print the current
6640 source location, and to try risks causing an error message about
6641 missing source files. */
6642 if (stop_print_frame
&& !batch_silent
)
6643 print_stop_event (&last
);
6646 /* Save the function value return registers, if we care.
6647 We might be about to restore their previous contents. */
6648 if (inferior_thread ()->control
.proceed_to_finish
6649 && execution_direction
!= EXEC_REVERSE
)
6651 /* This should not be necessary. */
6653 regcache_xfree (stop_registers
);
6655 /* NB: The copy goes through to the target picking up the value of
6656 all the registers. */
6657 stop_registers
= regcache_dup (get_current_regcache ());
6660 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
6662 /* Pop the empty frame that contains the stack dummy.
6663 This also restores inferior state prior to the call
6664 (struct infcall_suspend_state). */
6665 struct frame_info
*frame
= get_current_frame ();
6667 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
6669 /* frame_pop() calls reinit_frame_cache as the last thing it
6670 does which means there's currently no selected frame. We
6671 don't need to re-establish a selected frame if the dummy call
6672 returns normally, that will be done by
6673 restore_infcall_control_state. However, we do have to handle
6674 the case where the dummy call is returning after being
6675 stopped (e.g. the dummy call previously hit a breakpoint).
6676 We can't know which case we have so just always re-establish
6677 a selected frame here. */
6678 select_frame (get_current_frame ());
6682 annotate_stopped ();
6684 /* Suppress the stop observer if we're in the middle of:
6686 - a step n (n > 1), as there still more steps to be done.
6688 - a "finish" command, as the observer will be called in
6689 finish_command_continuation, so it can include the inferior
6690 function's return value.
6692 - calling an inferior function, as we pretend we inferior didn't
6693 run at all. The return value of the call is handled by the
6694 expression evaluator, through call_function_by_hand. */
6696 if (!target_has_execution
6697 || last
.kind
== TARGET_WAITKIND_SIGNALLED
6698 || last
.kind
== TARGET_WAITKIND_EXITED
6699 || last
.kind
== TARGET_WAITKIND_NO_RESUMED
6700 || (!(inferior_thread ()->step_multi
6701 && inferior_thread ()->control
.stop_step
)
6702 && !(inferior_thread ()->control
.stop_bpstat
6703 && inferior_thread ()->control
.proceed_to_finish
)
6704 && !inferior_thread ()->control
.in_infcall
))
6706 if (!ptid_equal (inferior_ptid
, null_ptid
))
6707 observer_notify_normal_stop (inferior_thread ()->control
.stop_bpstat
,
6710 observer_notify_normal_stop (NULL
, stop_print_frame
);
6713 if (target_has_execution
)
6715 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
6716 && last
.kind
!= TARGET_WAITKIND_EXITED
)
6717 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6718 Delete any breakpoint that is to be deleted at the next stop. */
6719 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
6722 /* Try to get rid of automatically added inferiors that are no
6723 longer needed. Keeping those around slows down things linearly.
6724 Note that this never removes the current inferior. */
6729 hook_stop_stub (void *cmd
)
6731 execute_cmd_pre_hook ((struct cmd_list_element
*) cmd
);
6736 signal_stop_state (int signo
)
6738 return signal_stop
[signo
];
6742 signal_print_state (int signo
)
6744 return signal_print
[signo
];
6748 signal_pass_state (int signo
)
6750 return signal_program
[signo
];
6754 signal_cache_update (int signo
)
6758 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
6759 signal_cache_update (signo
);
6764 signal_pass
[signo
] = (signal_stop
[signo
] == 0
6765 && signal_print
[signo
] == 0
6766 && signal_program
[signo
] == 1
6767 && signal_catch
[signo
] == 0);
6771 signal_stop_update (int signo
, int state
)
6773 int ret
= signal_stop
[signo
];
6775 signal_stop
[signo
] = state
;
6776 signal_cache_update (signo
);
6781 signal_print_update (int signo
, int state
)
6783 int ret
= signal_print
[signo
];
6785 signal_print
[signo
] = state
;
6786 signal_cache_update (signo
);
6791 signal_pass_update (int signo
, int state
)
6793 int ret
= signal_program
[signo
];
6795 signal_program
[signo
] = state
;
6796 signal_cache_update (signo
);
6800 /* Update the global 'signal_catch' from INFO and notify the
6804 signal_catch_update (const unsigned int *info
)
6808 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
6809 signal_catch
[i
] = info
[i
] > 0;
6810 signal_cache_update (-1);
6811 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
6815 sig_print_header (void)
6817 printf_filtered (_("Signal Stop\tPrint\tPass "
6818 "to program\tDescription\n"));
6822 sig_print_info (enum gdb_signal oursig
)
6824 const char *name
= gdb_signal_to_name (oursig
);
6825 int name_padding
= 13 - strlen (name
);
6827 if (name_padding
<= 0)
6830 printf_filtered ("%s", name
);
6831 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
6832 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
6833 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
6834 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
6835 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
6838 /* Specify how various signals in the inferior should be handled. */
6841 handle_command (char *args
, int from_tty
)
6844 int digits
, wordlen
;
6845 int sigfirst
, signum
, siglast
;
6846 enum gdb_signal oursig
;
6849 unsigned char *sigs
;
6850 struct cleanup
*old_chain
;
6854 error_no_arg (_("signal to handle"));
6857 /* Allocate and zero an array of flags for which signals to handle. */
6859 nsigs
= (int) GDB_SIGNAL_LAST
;
6860 sigs
= (unsigned char *) alloca (nsigs
);
6861 memset (sigs
, 0, nsigs
);
6863 /* Break the command line up into args. */
6865 argv
= gdb_buildargv (args
);
6866 old_chain
= make_cleanup_freeargv (argv
);
6868 /* Walk through the args, looking for signal oursigs, signal names, and
6869 actions. Signal numbers and signal names may be interspersed with
6870 actions, with the actions being performed for all signals cumulatively
6871 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6873 while (*argv
!= NULL
)
6875 wordlen
= strlen (*argv
);
6876 for (digits
= 0; isdigit ((*argv
)[digits
]); digits
++)
6880 sigfirst
= siglast
= -1;
6882 if (wordlen
>= 1 && !strncmp (*argv
, "all", wordlen
))
6884 /* Apply action to all signals except those used by the
6885 debugger. Silently skip those. */
6888 siglast
= nsigs
- 1;
6890 else if (wordlen
>= 1 && !strncmp (*argv
, "stop", wordlen
))
6892 SET_SIGS (nsigs
, sigs
, signal_stop
);
6893 SET_SIGS (nsigs
, sigs
, signal_print
);
6895 else if (wordlen
>= 1 && !strncmp (*argv
, "ignore", wordlen
))
6897 UNSET_SIGS (nsigs
, sigs
, signal_program
);
6899 else if (wordlen
>= 2 && !strncmp (*argv
, "print", wordlen
))
6901 SET_SIGS (nsigs
, sigs
, signal_print
);
6903 else if (wordlen
>= 2 && !strncmp (*argv
, "pass", wordlen
))
6905 SET_SIGS (nsigs
, sigs
, signal_program
);
6907 else if (wordlen
>= 3 && !strncmp (*argv
, "nostop", wordlen
))
6909 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
6911 else if (wordlen
>= 3 && !strncmp (*argv
, "noignore", wordlen
))
6913 SET_SIGS (nsigs
, sigs
, signal_program
);
6915 else if (wordlen
>= 4 && !strncmp (*argv
, "noprint", wordlen
))
6917 UNSET_SIGS (nsigs
, sigs
, signal_print
);
6918 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
6920 else if (wordlen
>= 4 && !strncmp (*argv
, "nopass", wordlen
))
6922 UNSET_SIGS (nsigs
, sigs
, signal_program
);
6924 else if (digits
> 0)
6926 /* It is numeric. The numeric signal refers to our own
6927 internal signal numbering from target.h, not to host/target
6928 signal number. This is a feature; users really should be
6929 using symbolic names anyway, and the common ones like
6930 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6932 sigfirst
= siglast
= (int)
6933 gdb_signal_from_command (atoi (*argv
));
6934 if ((*argv
)[digits
] == '-')
6937 gdb_signal_from_command (atoi ((*argv
) + digits
+ 1));
6939 if (sigfirst
> siglast
)
6941 /* Bet he didn't figure we'd think of this case... */
6949 oursig
= gdb_signal_from_name (*argv
);
6950 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
6952 sigfirst
= siglast
= (int) oursig
;
6956 /* Not a number and not a recognized flag word => complain. */
6957 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv
);
6961 /* If any signal numbers or symbol names were found, set flags for
6962 which signals to apply actions to. */
6964 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
6966 switch ((enum gdb_signal
) signum
)
6968 case GDB_SIGNAL_TRAP
:
6969 case GDB_SIGNAL_INT
:
6970 if (!allsigs
&& !sigs
[signum
])
6972 if (query (_("%s is used by the debugger.\n\
6973 Are you sure you want to change it? "),
6974 gdb_signal_to_name ((enum gdb_signal
) signum
)))
6980 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6981 gdb_flush (gdb_stdout
);
6986 case GDB_SIGNAL_DEFAULT
:
6987 case GDB_SIGNAL_UNKNOWN
:
6988 /* Make sure that "all" doesn't print these. */
6999 for (signum
= 0; signum
< nsigs
; signum
++)
7002 signal_cache_update (-1);
7003 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
7004 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
7008 /* Show the results. */
7009 sig_print_header ();
7010 for (; signum
< nsigs
; signum
++)
7012 sig_print_info (signum
);
7018 do_cleanups (old_chain
);
7021 /* Complete the "handle" command. */
7023 static VEC (char_ptr
) *
7024 handle_completer (struct cmd_list_element
*ignore
,
7025 const char *text
, const char *word
)
7027 VEC (char_ptr
) *vec_signals
, *vec_keywords
, *return_val
;
7028 static const char * const keywords
[] =
7042 vec_signals
= signal_completer (ignore
, text
, word
);
7043 vec_keywords
= complete_on_enum (keywords
, word
, word
);
7045 return_val
= VEC_merge (char_ptr
, vec_signals
, vec_keywords
);
7046 VEC_free (char_ptr
, vec_signals
);
7047 VEC_free (char_ptr
, vec_keywords
);
7052 xdb_handle_command (char *args
, int from_tty
)
7055 struct cleanup
*old_chain
;
7058 error_no_arg (_("xdb command"));
7060 /* Break the command line up into args. */
7062 argv
= gdb_buildargv (args
);
7063 old_chain
= make_cleanup_freeargv (argv
);
7064 if (argv
[1] != (char *) NULL
)
7069 bufLen
= strlen (argv
[0]) + 20;
7070 argBuf
= (char *) xmalloc (bufLen
);
7074 enum gdb_signal oursig
;
7076 oursig
= gdb_signal_from_name (argv
[0]);
7077 memset (argBuf
, 0, bufLen
);
7078 if (strcmp (argv
[1], "Q") == 0)
7079 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
7082 if (strcmp (argv
[1], "s") == 0)
7084 if (!signal_stop
[oursig
])
7085 sprintf (argBuf
, "%s %s", argv
[0], "stop");
7087 sprintf (argBuf
, "%s %s", argv
[0], "nostop");
7089 else if (strcmp (argv
[1], "i") == 0)
7091 if (!signal_program
[oursig
])
7092 sprintf (argBuf
, "%s %s", argv
[0], "pass");
7094 sprintf (argBuf
, "%s %s", argv
[0], "nopass");
7096 else if (strcmp (argv
[1], "r") == 0)
7098 if (!signal_print
[oursig
])
7099 sprintf (argBuf
, "%s %s", argv
[0], "print");
7101 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
7107 handle_command (argBuf
, from_tty
);
7109 printf_filtered (_("Invalid signal handling flag.\n"));
7114 do_cleanups (old_chain
);
7118 gdb_signal_from_command (int num
)
7120 if (num
>= 1 && num
<= 15)
7121 return (enum gdb_signal
) num
;
7122 error (_("Only signals 1-15 are valid as numeric signals.\n\
7123 Use \"info signals\" for a list of symbolic signals."));
7126 /* Print current contents of the tables set by the handle command.
7127 It is possible we should just be printing signals actually used
7128 by the current target (but for things to work right when switching
7129 targets, all signals should be in the signal tables). */
7132 signals_info (char *signum_exp
, int from_tty
)
7134 enum gdb_signal oursig
;
7136 sig_print_header ();
7140 /* First see if this is a symbol name. */
7141 oursig
= gdb_signal_from_name (signum_exp
);
7142 if (oursig
== GDB_SIGNAL_UNKNOWN
)
7144 /* No, try numeric. */
7146 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
7148 sig_print_info (oursig
);
7152 printf_filtered ("\n");
7153 /* These ugly casts brought to you by the native VAX compiler. */
7154 for (oursig
= GDB_SIGNAL_FIRST
;
7155 (int) oursig
< (int) GDB_SIGNAL_LAST
;
7156 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
7160 if (oursig
!= GDB_SIGNAL_UNKNOWN
7161 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
7162 sig_print_info (oursig
);
7165 printf_filtered (_("\nUse the \"handle\" command "
7166 "to change these tables.\n"));
7169 /* Check if it makes sense to read $_siginfo from the current thread
7170 at this point. If not, throw an error. */
7173 validate_siginfo_access (void)
7175 /* No current inferior, no siginfo. */
7176 if (ptid_equal (inferior_ptid
, null_ptid
))
7177 error (_("No thread selected."));
7179 /* Don't try to read from a dead thread. */
7180 if (is_exited (inferior_ptid
))
7181 error (_("The current thread has terminated"));
7183 /* ... or from a spinning thread. */
7184 if (is_running (inferior_ptid
))
7185 error (_("Selected thread is running."));
7188 /* The $_siginfo convenience variable is a bit special. We don't know
7189 for sure the type of the value until we actually have a chance to
7190 fetch the data. The type can change depending on gdbarch, so it is
7191 also dependent on which thread you have selected.
7193 1. making $_siginfo be an internalvar that creates a new value on
7196 2. making the value of $_siginfo be an lval_computed value. */
7198 /* This function implements the lval_computed support for reading a
7202 siginfo_value_read (struct value
*v
)
7204 LONGEST transferred
;
7206 validate_siginfo_access ();
7209 target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
,
7211 value_contents_all_raw (v
),
7213 TYPE_LENGTH (value_type (v
)));
7215 if (transferred
!= TYPE_LENGTH (value_type (v
)))
7216 error (_("Unable to read siginfo"));
7219 /* This function implements the lval_computed support for writing a
7223 siginfo_value_write (struct value
*v
, struct value
*fromval
)
7225 LONGEST transferred
;
7227 validate_siginfo_access ();
7229 transferred
= target_write (¤t_target
,
7230 TARGET_OBJECT_SIGNAL_INFO
,
7232 value_contents_all_raw (fromval
),
7234 TYPE_LENGTH (value_type (fromval
)));
7236 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
7237 error (_("Unable to write siginfo"));
7240 static const struct lval_funcs siginfo_value_funcs
=
7246 /* Return a new value with the correct type for the siginfo object of
7247 the current thread using architecture GDBARCH. Return a void value
7248 if there's no object available. */
7250 static struct value
*
7251 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
7254 if (target_has_stack
7255 && !ptid_equal (inferior_ptid
, null_ptid
)
7256 && gdbarch_get_siginfo_type_p (gdbarch
))
7258 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
7260 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
7263 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
7267 /* infcall_suspend_state contains state about the program itself like its
7268 registers and any signal it received when it last stopped.
7269 This state must be restored regardless of how the inferior function call
7270 ends (either successfully, or after it hits a breakpoint or signal)
7271 if the program is to properly continue where it left off. */
7273 struct infcall_suspend_state
7275 struct thread_suspend_state thread_suspend
;
7276 #if 0 /* Currently unused and empty structures are not valid C. */
7277 struct inferior_suspend_state inferior_suspend
;
7282 struct regcache
*registers
;
7284 /* Format of SIGINFO_DATA or NULL if it is not present. */
7285 struct gdbarch
*siginfo_gdbarch
;
7287 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
7288 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
7289 content would be invalid. */
7290 gdb_byte
*siginfo_data
;
7293 struct infcall_suspend_state
*
7294 save_infcall_suspend_state (void)
7296 struct infcall_suspend_state
*inf_state
;
7297 struct thread_info
*tp
= inferior_thread ();
7299 struct inferior
*inf
= current_inferior ();
7301 struct regcache
*regcache
= get_current_regcache ();
7302 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
7303 gdb_byte
*siginfo_data
= NULL
;
7305 if (gdbarch_get_siginfo_type_p (gdbarch
))
7307 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
7308 size_t len
= TYPE_LENGTH (type
);
7309 struct cleanup
*back_to
;
7311 siginfo_data
= xmalloc (len
);
7312 back_to
= make_cleanup (xfree
, siginfo_data
);
7314 if (target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
7315 siginfo_data
, 0, len
) == len
)
7316 discard_cleanups (back_to
);
7319 /* Errors ignored. */
7320 do_cleanups (back_to
);
7321 siginfo_data
= NULL
;
7325 inf_state
= XCNEW (struct infcall_suspend_state
);
7329 inf_state
->siginfo_gdbarch
= gdbarch
;
7330 inf_state
->siginfo_data
= siginfo_data
;
7333 inf_state
->thread_suspend
= tp
->suspend
;
7334 #if 0 /* Currently unused and empty structures are not valid C. */
7335 inf_state
->inferior_suspend
= inf
->suspend
;
7338 /* run_inferior_call will not use the signal due to its `proceed' call with
7339 GDB_SIGNAL_0 anyway. */
7340 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7342 inf_state
->stop_pc
= stop_pc
;
7344 inf_state
->registers
= regcache_dup (regcache
);
7349 /* Restore inferior session state to INF_STATE. */
7352 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
7354 struct thread_info
*tp
= inferior_thread ();
7356 struct inferior
*inf
= current_inferior ();
7358 struct regcache
*regcache
= get_current_regcache ();
7359 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
7361 tp
->suspend
= inf_state
->thread_suspend
;
7362 #if 0 /* Currently unused and empty structures are not valid C. */
7363 inf
->suspend
= inf_state
->inferior_suspend
;
7366 stop_pc
= inf_state
->stop_pc
;
7368 if (inf_state
->siginfo_gdbarch
== gdbarch
)
7370 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
7372 /* Errors ignored. */
7373 target_write (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
7374 inf_state
->siginfo_data
, 0, TYPE_LENGTH (type
));
7377 /* The inferior can be gone if the user types "print exit(0)"
7378 (and perhaps other times). */
7379 if (target_has_execution
)
7380 /* NB: The register write goes through to the target. */
7381 regcache_cpy (regcache
, inf_state
->registers
);
7383 discard_infcall_suspend_state (inf_state
);
7387 do_restore_infcall_suspend_state_cleanup (void *state
)
7389 restore_infcall_suspend_state (state
);
7393 make_cleanup_restore_infcall_suspend_state
7394 (struct infcall_suspend_state
*inf_state
)
7396 return make_cleanup (do_restore_infcall_suspend_state_cleanup
, inf_state
);
7400 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
7402 regcache_xfree (inf_state
->registers
);
7403 xfree (inf_state
->siginfo_data
);
7408 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
7410 return inf_state
->registers
;
7413 /* infcall_control_state contains state regarding gdb's control of the
7414 inferior itself like stepping control. It also contains session state like
7415 the user's currently selected frame. */
7417 struct infcall_control_state
7419 struct thread_control_state thread_control
;
7420 struct inferior_control_state inferior_control
;
7423 enum stop_stack_kind stop_stack_dummy
;
7424 int stopped_by_random_signal
;
7425 int stop_after_trap
;
7427 /* ID if the selected frame when the inferior function call was made. */
7428 struct frame_id selected_frame_id
;
7431 /* Save all of the information associated with the inferior<==>gdb
7434 struct infcall_control_state
*
7435 save_infcall_control_state (void)
7437 struct infcall_control_state
*inf_status
= xmalloc (sizeof (*inf_status
));
7438 struct thread_info
*tp
= inferior_thread ();
7439 struct inferior
*inf
= current_inferior ();
7441 inf_status
->thread_control
= tp
->control
;
7442 inf_status
->inferior_control
= inf
->control
;
7444 tp
->control
.step_resume_breakpoint
= NULL
;
7445 tp
->control
.exception_resume_breakpoint
= NULL
;
7447 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
7448 chain. If caller's caller is walking the chain, they'll be happier if we
7449 hand them back the original chain when restore_infcall_control_state is
7451 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
7454 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
7455 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
7456 inf_status
->stop_after_trap
= stop_after_trap
;
7458 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
7464 restore_selected_frame (void *args
)
7466 struct frame_id
*fid
= (struct frame_id
*) args
;
7467 struct frame_info
*frame
;
7469 frame
= frame_find_by_id (*fid
);
7471 /* If inf_status->selected_frame_id is NULL, there was no previously
7475 warning (_("Unable to restore previously selected frame."));
7479 select_frame (frame
);
7484 /* Restore inferior session state to INF_STATUS. */
7487 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
7489 struct thread_info
*tp
= inferior_thread ();
7490 struct inferior
*inf
= current_inferior ();
7492 if (tp
->control
.step_resume_breakpoint
)
7493 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
7495 if (tp
->control
.exception_resume_breakpoint
)
7496 tp
->control
.exception_resume_breakpoint
->disposition
7497 = disp_del_at_next_stop
;
7499 /* Handle the bpstat_copy of the chain. */
7500 bpstat_clear (&tp
->control
.stop_bpstat
);
7502 tp
->control
= inf_status
->thread_control
;
7503 inf
->control
= inf_status
->inferior_control
;
7506 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
7507 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
7508 stop_after_trap
= inf_status
->stop_after_trap
;
7510 if (target_has_stack
)
7512 /* The point of catch_errors is that if the stack is clobbered,
7513 walking the stack might encounter a garbage pointer and
7514 error() trying to dereference it. */
7516 (restore_selected_frame
, &inf_status
->selected_frame_id
,
7517 "Unable to restore previously selected frame:\n",
7518 RETURN_MASK_ERROR
) == 0)
7519 /* Error in restoring the selected frame. Select the innermost
7521 select_frame (get_current_frame ());
7528 do_restore_infcall_control_state_cleanup (void *sts
)
7530 restore_infcall_control_state (sts
);
7534 make_cleanup_restore_infcall_control_state
7535 (struct infcall_control_state
*inf_status
)
7537 return make_cleanup (do_restore_infcall_control_state_cleanup
, inf_status
);
7541 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
7543 if (inf_status
->thread_control
.step_resume_breakpoint
)
7544 inf_status
->thread_control
.step_resume_breakpoint
->disposition
7545 = disp_del_at_next_stop
;
7547 if (inf_status
->thread_control
.exception_resume_breakpoint
)
7548 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
7549 = disp_del_at_next_stop
;
7551 /* See save_infcall_control_state for info on stop_bpstat. */
7552 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
7557 /* restore_inferior_ptid() will be used by the cleanup machinery
7558 to restore the inferior_ptid value saved in a call to
7559 save_inferior_ptid(). */
7562 restore_inferior_ptid (void *arg
)
7564 ptid_t
*saved_ptid_ptr
= arg
;
7566 inferior_ptid
= *saved_ptid_ptr
;
7570 /* Save the value of inferior_ptid so that it may be restored by a
7571 later call to do_cleanups(). Returns the struct cleanup pointer
7572 needed for later doing the cleanup. */
7575 save_inferior_ptid (void)
7577 ptid_t
*saved_ptid_ptr
;
7579 saved_ptid_ptr
= xmalloc (sizeof (ptid_t
));
7580 *saved_ptid_ptr
= inferior_ptid
;
7581 return make_cleanup (restore_inferior_ptid
, saved_ptid_ptr
);
7587 clear_exit_convenience_vars (void)
7589 clear_internalvar (lookup_internalvar ("_exitsignal"));
7590 clear_internalvar (lookup_internalvar ("_exitcode"));
7594 /* User interface for reverse debugging:
7595 Set exec-direction / show exec-direction commands
7596 (returns error unless target implements to_set_exec_direction method). */
7598 int execution_direction
= EXEC_FORWARD
;
7599 static const char exec_forward
[] = "forward";
7600 static const char exec_reverse
[] = "reverse";
7601 static const char *exec_direction
= exec_forward
;
7602 static const char *const exec_direction_names
[] = {
7609 set_exec_direction_func (char *args
, int from_tty
,
7610 struct cmd_list_element
*cmd
)
7612 if (target_can_execute_reverse
)
7614 if (!strcmp (exec_direction
, exec_forward
))
7615 execution_direction
= EXEC_FORWARD
;
7616 else if (!strcmp (exec_direction
, exec_reverse
))
7617 execution_direction
= EXEC_REVERSE
;
7621 exec_direction
= exec_forward
;
7622 error (_("Target does not support this operation."));
7627 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
7628 struct cmd_list_element
*cmd
, const char *value
)
7630 switch (execution_direction
) {
7632 fprintf_filtered (out
, _("Forward.\n"));
7635 fprintf_filtered (out
, _("Reverse.\n"));
7638 internal_error (__FILE__
, __LINE__
,
7639 _("bogus execution_direction value: %d"),
7640 (int) execution_direction
);
7645 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
7646 struct cmd_list_element
*c
, const char *value
)
7648 fprintf_filtered (file
, _("Resuming the execution of threads "
7649 "of all processes is %s.\n"), value
);
7652 /* Implementation of `siginfo' variable. */
7654 static const struct internalvar_funcs siginfo_funcs
=
7662 _initialize_infrun (void)
7666 struct cmd_list_element
*c
;
7668 add_info ("signals", signals_info
, _("\
7669 What debugger does when program gets various signals.\n\
7670 Specify a signal as argument to print info on that signal only."));
7671 add_info_alias ("handle", "signals", 0);
7673 c
= add_com ("handle", class_run
, handle_command
, _("\
7674 Specify how to handle signals.\n\
7675 Usage: handle SIGNAL [ACTIONS]\n\
7676 Args are signals and actions to apply to those signals.\n\
7677 If no actions are specified, the current settings for the specified signals\n\
7678 will be displayed instead.\n\
7680 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7681 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7682 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7683 The special arg \"all\" is recognized to mean all signals except those\n\
7684 used by the debugger, typically SIGTRAP and SIGINT.\n\
7686 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7687 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7688 Stop means reenter debugger if this signal happens (implies print).\n\
7689 Print means print a message if this signal happens.\n\
7690 Pass means let program see this signal; otherwise program doesn't know.\n\
7691 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7692 Pass and Stop may be combined.\n\
7694 Multiple signals may be specified. Signal numbers and signal names\n\
7695 may be interspersed with actions, with the actions being performed for\n\
7696 all signals cumulatively specified."));
7697 set_cmd_completer (c
, handle_completer
);
7701 add_com ("lz", class_info
, signals_info
, _("\
7702 What debugger does when program gets various signals.\n\
7703 Specify a signal as argument to print info on that signal only."));
7704 add_com ("z", class_run
, xdb_handle_command
, _("\
7705 Specify how to handle a signal.\n\
7706 Args are signals and actions to apply to those signals.\n\
7707 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7708 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7709 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7710 The special arg \"all\" is recognized to mean all signals except those\n\
7711 used by the debugger, typically SIGTRAP and SIGINT.\n\
7712 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7713 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7714 nopass), \"Q\" (noprint)\n\
7715 Stop means reenter debugger if this signal happens (implies print).\n\
7716 Print means print a message if this signal happens.\n\
7717 Pass means let program see this signal; otherwise program doesn't know.\n\
7718 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7719 Pass and Stop may be combined."));
7723 stop_command
= add_cmd ("stop", class_obscure
,
7724 not_just_help_class_command
, _("\
7725 There is no `stop' command, but you can set a hook on `stop'.\n\
7726 This allows you to set a list of commands to be run each time execution\n\
7727 of the program stops."), &cmdlist
);
7729 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
7730 Set inferior debugging."), _("\
7731 Show inferior debugging."), _("\
7732 When non-zero, inferior specific debugging is enabled."),
7735 &setdebuglist
, &showdebuglist
);
7737 add_setshow_boolean_cmd ("displaced", class_maintenance
,
7738 &debug_displaced
, _("\
7739 Set displaced stepping debugging."), _("\
7740 Show displaced stepping debugging."), _("\
7741 When non-zero, displaced stepping specific debugging is enabled."),
7743 show_debug_displaced
,
7744 &setdebuglist
, &showdebuglist
);
7746 add_setshow_boolean_cmd ("non-stop", no_class
,
7748 Set whether gdb controls the inferior in non-stop mode."), _("\
7749 Show whether gdb controls the inferior in non-stop mode."), _("\
7750 When debugging a multi-threaded program and this setting is\n\
7751 off (the default, also called all-stop mode), when one thread stops\n\
7752 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7753 all other threads in the program while you interact with the thread of\n\
7754 interest. When you continue or step a thread, you can allow the other\n\
7755 threads to run, or have them remain stopped, but while you inspect any\n\
7756 thread's state, all threads stop.\n\
7758 In non-stop mode, when one thread stops, other threads can continue\n\
7759 to run freely. You'll be able to step each thread independently,\n\
7760 leave it stopped or free to run as needed."),
7766 numsigs
= (int) GDB_SIGNAL_LAST
;
7767 signal_stop
= (unsigned char *) xmalloc (sizeof (signal_stop
[0]) * numsigs
);
7768 signal_print
= (unsigned char *)
7769 xmalloc (sizeof (signal_print
[0]) * numsigs
);
7770 signal_program
= (unsigned char *)
7771 xmalloc (sizeof (signal_program
[0]) * numsigs
);
7772 signal_catch
= (unsigned char *)
7773 xmalloc (sizeof (signal_catch
[0]) * numsigs
);
7774 signal_pass
= (unsigned char *)
7775 xmalloc (sizeof (signal_pass
[0]) * numsigs
);
7776 for (i
= 0; i
< numsigs
; i
++)
7779 signal_print
[i
] = 1;
7780 signal_program
[i
] = 1;
7781 signal_catch
[i
] = 0;
7784 /* Signals caused by debugger's own actions
7785 should not be given to the program afterwards. */
7786 signal_program
[GDB_SIGNAL_TRAP
] = 0;
7787 signal_program
[GDB_SIGNAL_INT
] = 0;
7789 /* Signals that are not errors should not normally enter the debugger. */
7790 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
7791 signal_print
[GDB_SIGNAL_ALRM
] = 0;
7792 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
7793 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
7794 signal_stop
[GDB_SIGNAL_PROF
] = 0;
7795 signal_print
[GDB_SIGNAL_PROF
] = 0;
7796 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
7797 signal_print
[GDB_SIGNAL_CHLD
] = 0;
7798 signal_stop
[GDB_SIGNAL_IO
] = 0;
7799 signal_print
[GDB_SIGNAL_IO
] = 0;
7800 signal_stop
[GDB_SIGNAL_POLL
] = 0;
7801 signal_print
[GDB_SIGNAL_POLL
] = 0;
7802 signal_stop
[GDB_SIGNAL_URG
] = 0;
7803 signal_print
[GDB_SIGNAL_URG
] = 0;
7804 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
7805 signal_print
[GDB_SIGNAL_WINCH
] = 0;
7806 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
7807 signal_print
[GDB_SIGNAL_PRIO
] = 0;
7809 /* These signals are used internally by user-level thread
7810 implementations. (See signal(5) on Solaris.) Like the above
7811 signals, a healthy program receives and handles them as part of
7812 its normal operation. */
7813 signal_stop
[GDB_SIGNAL_LWP
] = 0;
7814 signal_print
[GDB_SIGNAL_LWP
] = 0;
7815 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
7816 signal_print
[GDB_SIGNAL_WAITING
] = 0;
7817 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
7818 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
7820 /* Update cached state. */
7821 signal_cache_update (-1);
7823 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
7824 &stop_on_solib_events
, _("\
7825 Set stopping for shared library events."), _("\
7826 Show stopping for shared library events."), _("\
7827 If nonzero, gdb will give control to the user when the dynamic linker\n\
7828 notifies gdb of shared library events. The most common event of interest\n\
7829 to the user would be loading/unloading of a new library."),
7830 set_stop_on_solib_events
,
7831 show_stop_on_solib_events
,
7832 &setlist
, &showlist
);
7834 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
7835 follow_fork_mode_kind_names
,
7836 &follow_fork_mode_string
, _("\
7837 Set debugger response to a program call of fork or vfork."), _("\
7838 Show debugger response to a program call of fork or vfork."), _("\
7839 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7840 parent - the original process is debugged after a fork\n\
7841 child - the new process is debugged after a fork\n\
7842 The unfollowed process will continue to run.\n\
7843 By default, the debugger will follow the parent process."),
7845 show_follow_fork_mode_string
,
7846 &setlist
, &showlist
);
7848 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
7849 follow_exec_mode_names
,
7850 &follow_exec_mode_string
, _("\
7851 Set debugger response to a program call of exec."), _("\
7852 Show debugger response to a program call of exec."), _("\
7853 An exec call replaces the program image of a process.\n\
7855 follow-exec-mode can be:\n\
7857 new - the debugger creates a new inferior and rebinds the process\n\
7858 to this new inferior. The program the process was running before\n\
7859 the exec call can be restarted afterwards by restarting the original\n\
7862 same - the debugger keeps the process bound to the same inferior.\n\
7863 The new executable image replaces the previous executable loaded in\n\
7864 the inferior. Restarting the inferior after the exec call restarts\n\
7865 the executable the process was running after the exec call.\n\
7867 By default, the debugger will use the same inferior."),
7869 show_follow_exec_mode_string
,
7870 &setlist
, &showlist
);
7872 add_setshow_enum_cmd ("scheduler-locking", class_run
,
7873 scheduler_enums
, &scheduler_mode
, _("\
7874 Set mode for locking scheduler during execution."), _("\
7875 Show mode for locking scheduler during execution."), _("\
7876 off == no locking (threads may preempt at any time)\n\
7877 on == full locking (no thread except the current thread may run)\n\
7878 step == scheduler locked during every single-step operation.\n\
7879 In this mode, no other thread may run during a step command.\n\
7880 Other threads may run while stepping over a function call ('next')."),
7881 set_schedlock_func
, /* traps on target vector */
7882 show_scheduler_mode
,
7883 &setlist
, &showlist
);
7885 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
7886 Set mode for resuming threads of all processes."), _("\
7887 Show mode for resuming threads of all processes."), _("\
7888 When on, execution commands (such as 'continue' or 'next') resume all\n\
7889 threads of all processes. When off (which is the default), execution\n\
7890 commands only resume the threads of the current process. The set of\n\
7891 threads that are resumed is further refined by the scheduler-locking\n\
7892 mode (see help set scheduler-locking)."),
7894 show_schedule_multiple
,
7895 &setlist
, &showlist
);
7897 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
7898 Set mode of the step operation."), _("\
7899 Show mode of the step operation."), _("\
7900 When set, doing a step over a function without debug line information\n\
7901 will stop at the first instruction of that function. Otherwise, the\n\
7902 function is skipped and the step command stops at a different source line."),
7904 show_step_stop_if_no_debug
,
7905 &setlist
, &showlist
);
7907 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
7908 &can_use_displaced_stepping
, _("\
7909 Set debugger's willingness to use displaced stepping."), _("\
7910 Show debugger's willingness to use displaced stepping."), _("\
7911 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7912 supported by the target architecture. If off, gdb will not use displaced\n\
7913 stepping to step over breakpoints, even if such is supported by the target\n\
7914 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7915 if the target architecture supports it and non-stop mode is active, but will not\n\
7916 use it in all-stop mode (see help set non-stop)."),
7918 show_can_use_displaced_stepping
,
7919 &setlist
, &showlist
);
7921 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
7922 &exec_direction
, _("Set direction of execution.\n\
7923 Options are 'forward' or 'reverse'."),
7924 _("Show direction of execution (forward/reverse)."),
7925 _("Tells gdb whether to execute forward or backward."),
7926 set_exec_direction_func
, show_exec_direction_func
,
7927 &setlist
, &showlist
);
7929 /* Set/show detach-on-fork: user-settable mode. */
7931 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
7932 Set whether gdb will detach the child of a fork."), _("\
7933 Show whether gdb will detach the child of a fork."), _("\
7934 Tells gdb whether to detach the child of a fork."),
7935 NULL
, NULL
, &setlist
, &showlist
);
7937 /* Set/show disable address space randomization mode. */
7939 add_setshow_boolean_cmd ("disable-randomization", class_support
,
7940 &disable_randomization
, _("\
7941 Set disabling of debuggee's virtual address space randomization."), _("\
7942 Show disabling of debuggee's virtual address space randomization."), _("\
7943 When this mode is on (which is the default), randomization of the virtual\n\
7944 address space is disabled. Standalone programs run with the randomization\n\
7945 enabled by default on some platforms."),
7946 &set_disable_randomization
,
7947 &show_disable_randomization
,
7948 &setlist
, &showlist
);
7950 /* ptid initializations */
7951 inferior_ptid
= null_ptid
;
7952 target_last_wait_ptid
= minus_one_ptid
;
7954 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed
);
7955 observer_attach_thread_stop_requested (infrun_thread_stop_requested
);
7956 observer_attach_thread_exit (infrun_thread_thread_exit
);
7957 observer_attach_inferior_exit (infrun_inferior_exit
);
7959 /* Explicitly create without lookup, since that tries to create a
7960 value with a void typed value, and when we get here, gdbarch
7961 isn't initialized yet. At this point, we're quite sure there
7962 isn't another convenience variable of the same name. */
7963 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
7965 add_setshow_boolean_cmd ("observer", no_class
,
7966 &observer_mode_1
, _("\
7967 Set whether gdb controls the inferior in observer mode."), _("\
7968 Show whether gdb controls the inferior in observer mode."), _("\
7969 In observer mode, GDB can get data from the inferior, but not\n\
7970 affect its execution. Registers and memory may not be changed,\n\
7971 breakpoints may not be set, and the program cannot be interrupted\n\