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 void _initialize_infrun (void);
93 void nullify_last_target_wait_ptid (void);
95 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
97 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
99 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
101 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
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
);
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_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 /* Return true if process PID has a thread doing a displaced step. */
1471 displaced_step_in_progress (int pid
)
1473 struct displaced_step_inferior_state
*displaced
;
1475 displaced
= get_displaced_stepping_state (pid
);
1476 if (displaced
!= NULL
&& !ptid_equal (displaced
->step_ptid
, null_ptid
))
1482 /* Add a new displaced stepping state for process PID to the displaced
1483 stepping state list, or return a pointer to an already existing
1484 entry, if it already exists. Never returns NULL. */
1486 static struct displaced_step_inferior_state
*
1487 add_displaced_stepping_state (int pid
)
1489 struct displaced_step_inferior_state
*state
;
1491 for (state
= displaced_step_inferior_states
;
1493 state
= state
->next
)
1494 if (state
->pid
== pid
)
1497 state
= xcalloc (1, sizeof (*state
));
1499 state
->next
= displaced_step_inferior_states
;
1500 displaced_step_inferior_states
= state
;
1505 /* If inferior is in displaced stepping, and ADDR equals to starting address
1506 of copy area, return corresponding displaced_step_closure. Otherwise,
1509 struct displaced_step_closure
*
1510 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1512 struct displaced_step_inferior_state
*displaced
1513 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
1515 /* If checking the mode of displaced instruction in copy area. */
1516 if (displaced
&& !ptid_equal (displaced
->step_ptid
, null_ptid
)
1517 && (displaced
->step_copy
== addr
))
1518 return displaced
->step_closure
;
1523 /* Remove the displaced stepping state of process PID. */
1526 remove_displaced_stepping_state (int pid
)
1528 struct displaced_step_inferior_state
*it
, **prev_next_p
;
1530 gdb_assert (pid
!= 0);
1532 it
= displaced_step_inferior_states
;
1533 prev_next_p
= &displaced_step_inferior_states
;
1538 *prev_next_p
= it
->next
;
1543 prev_next_p
= &it
->next
;
1549 infrun_inferior_exit (struct inferior
*inf
)
1551 remove_displaced_stepping_state (inf
->pid
);
1554 /* If ON, and the architecture supports it, GDB will use displaced
1555 stepping to step over breakpoints. If OFF, or if the architecture
1556 doesn't support it, GDB will instead use the traditional
1557 hold-and-step approach. If AUTO (which is the default), GDB will
1558 decide which technique to use to step over breakpoints depending on
1559 which of all-stop or non-stop mode is active --- displaced stepping
1560 in non-stop mode; hold-and-step in all-stop mode. */
1562 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1565 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1566 struct cmd_list_element
*c
,
1569 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1570 fprintf_filtered (file
,
1571 _("Debugger's willingness to use displaced stepping "
1572 "to step over breakpoints is %s (currently %s).\n"),
1573 value
, non_stop
? "on" : "off");
1575 fprintf_filtered (file
,
1576 _("Debugger's willingness to use displaced stepping "
1577 "to step over breakpoints is %s.\n"), value
);
1580 /* Return non-zero if displaced stepping can/should be used to step
1581 over breakpoints. */
1584 use_displaced_stepping (struct gdbarch
*gdbarch
)
1586 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
&& non_stop
)
1587 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1588 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1589 && find_record_target () == NULL
);
1592 /* Clean out any stray displaced stepping state. */
1594 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1596 /* Indicate that there is no cleanup pending. */
1597 displaced
->step_ptid
= null_ptid
;
1599 if (displaced
->step_closure
)
1601 gdbarch_displaced_step_free_closure (displaced
->step_gdbarch
,
1602 displaced
->step_closure
);
1603 displaced
->step_closure
= NULL
;
1608 displaced_step_clear_cleanup (void *arg
)
1610 struct displaced_step_inferior_state
*state
= arg
;
1612 displaced_step_clear (state
);
1615 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1617 displaced_step_dump_bytes (struct ui_file
*file
,
1618 const gdb_byte
*buf
,
1623 for (i
= 0; i
< len
; i
++)
1624 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1625 fputs_unfiltered ("\n", file
);
1628 /* Prepare to single-step, using displaced stepping.
1630 Note that we cannot use displaced stepping when we have a signal to
1631 deliver. If we have a signal to deliver and an instruction to step
1632 over, then after the step, there will be no indication from the
1633 target whether the thread entered a signal handler or ignored the
1634 signal and stepped over the instruction successfully --- both cases
1635 result in a simple SIGTRAP. In the first case we mustn't do a
1636 fixup, and in the second case we must --- but we can't tell which.
1637 Comments in the code for 'random signals' in handle_inferior_event
1638 explain how we handle this case instead.
1640 Returns 1 if preparing was successful -- this thread is going to be
1641 stepped now; or 0 if displaced stepping this thread got queued. */
1643 displaced_step_prepare (ptid_t ptid
)
1645 struct cleanup
*old_cleanups
, *ignore_cleanups
;
1646 struct thread_info
*tp
= find_thread_ptid (ptid
);
1647 struct regcache
*regcache
= get_thread_regcache (ptid
);
1648 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1649 CORE_ADDR original
, copy
;
1651 struct displaced_step_closure
*closure
;
1652 struct displaced_step_inferior_state
*displaced
;
1655 /* We should never reach this function if the architecture does not
1656 support displaced stepping. */
1657 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1659 /* Disable range stepping while executing in the scratch pad. We
1660 want a single-step even if executing the displaced instruction in
1661 the scratch buffer lands within the stepping range (e.g., a
1663 tp
->control
.may_range_step
= 0;
1665 /* We have to displaced step one thread at a time, as we only have
1666 access to a single scratch space per inferior. */
1668 displaced
= add_displaced_stepping_state (ptid_get_pid (ptid
));
1670 if (!ptid_equal (displaced
->step_ptid
, null_ptid
))
1672 /* Already waiting for a displaced step to finish. Defer this
1673 request and place in queue. */
1674 struct displaced_step_request
*req
, *new_req
;
1676 if (debug_displaced
)
1677 fprintf_unfiltered (gdb_stdlog
,
1678 "displaced: defering step of %s\n",
1679 target_pid_to_str (ptid
));
1681 new_req
= xmalloc (sizeof (*new_req
));
1682 new_req
->ptid
= ptid
;
1683 new_req
->next
= NULL
;
1685 if (displaced
->step_request_queue
)
1687 for (req
= displaced
->step_request_queue
;
1691 req
->next
= new_req
;
1694 displaced
->step_request_queue
= new_req
;
1700 if (debug_displaced
)
1701 fprintf_unfiltered (gdb_stdlog
,
1702 "displaced: stepping %s now\n",
1703 target_pid_to_str (ptid
));
1706 displaced_step_clear (displaced
);
1708 old_cleanups
= save_inferior_ptid ();
1709 inferior_ptid
= ptid
;
1711 original
= regcache_read_pc (regcache
);
1713 copy
= gdbarch_displaced_step_location (gdbarch
);
1714 len
= gdbarch_max_insn_length (gdbarch
);
1716 /* Save the original contents of the copy area. */
1717 displaced
->step_saved_copy
= xmalloc (len
);
1718 ignore_cleanups
= make_cleanup (free_current_contents
,
1719 &displaced
->step_saved_copy
);
1720 status
= target_read_memory (copy
, displaced
->step_saved_copy
, len
);
1722 throw_error (MEMORY_ERROR
,
1723 _("Error accessing memory address %s (%s) for "
1724 "displaced-stepping scratch space."),
1725 paddress (gdbarch
, copy
), safe_strerror (status
));
1726 if (debug_displaced
)
1728 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1729 paddress (gdbarch
, copy
));
1730 displaced_step_dump_bytes (gdb_stdlog
,
1731 displaced
->step_saved_copy
,
1735 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1736 original
, copy
, regcache
);
1738 /* We don't support the fully-simulated case at present. */
1739 gdb_assert (closure
);
1741 /* Save the information we need to fix things up if the step
1743 displaced
->step_ptid
= ptid
;
1744 displaced
->step_gdbarch
= gdbarch
;
1745 displaced
->step_closure
= closure
;
1746 displaced
->step_original
= original
;
1747 displaced
->step_copy
= copy
;
1749 make_cleanup (displaced_step_clear_cleanup
, displaced
);
1751 /* Resume execution at the copy. */
1752 regcache_write_pc (regcache
, copy
);
1754 discard_cleanups (ignore_cleanups
);
1756 do_cleanups (old_cleanups
);
1758 if (debug_displaced
)
1759 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1760 paddress (gdbarch
, copy
));
1766 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1767 const gdb_byte
*myaddr
, int len
)
1769 struct cleanup
*ptid_cleanup
= save_inferior_ptid ();
1771 inferior_ptid
= ptid
;
1772 write_memory (memaddr
, myaddr
, len
);
1773 do_cleanups (ptid_cleanup
);
1776 /* Restore the contents of the copy area for thread PTID. */
1779 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1782 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1784 write_memory_ptid (ptid
, displaced
->step_copy
,
1785 displaced
->step_saved_copy
, len
);
1786 if (debug_displaced
)
1787 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1788 target_pid_to_str (ptid
),
1789 paddress (displaced
->step_gdbarch
,
1790 displaced
->step_copy
));
1794 displaced_step_fixup (ptid_t event_ptid
, enum gdb_signal signal
)
1796 struct cleanup
*old_cleanups
;
1797 struct displaced_step_inferior_state
*displaced
1798 = get_displaced_stepping_state (ptid_get_pid (event_ptid
));
1800 /* Was any thread of this process doing a displaced step? */
1801 if (displaced
== NULL
)
1804 /* Was this event for the pid we displaced? */
1805 if (ptid_equal (displaced
->step_ptid
, null_ptid
)
1806 || ! ptid_equal (displaced
->step_ptid
, event_ptid
))
1809 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, displaced
);
1811 displaced_step_restore (displaced
, displaced
->step_ptid
);
1813 /* Fixup may need to read memory/registers. Switch to the thread
1814 that we're fixing up. Also, target_stopped_by_watchpoint checks
1815 the current thread. */
1816 switch_to_thread (event_ptid
);
1818 /* Did the instruction complete successfully? */
1819 if (signal
== GDB_SIGNAL_TRAP
1820 && !(target_stopped_by_watchpoint ()
1821 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1822 || target_have_steppable_watchpoint
)))
1824 /* Fix up the resulting state. */
1825 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1826 displaced
->step_closure
,
1827 displaced
->step_original
,
1828 displaced
->step_copy
,
1829 get_thread_regcache (displaced
->step_ptid
));
1833 /* Since the instruction didn't complete, all we can do is
1835 struct regcache
*regcache
= get_thread_regcache (event_ptid
);
1836 CORE_ADDR pc
= regcache_read_pc (regcache
);
1838 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1839 regcache_write_pc (regcache
, pc
);
1842 do_cleanups (old_cleanups
);
1844 displaced
->step_ptid
= null_ptid
;
1846 /* Are there any pending displaced stepping requests? If so, run
1847 one now. Leave the state object around, since we're likely to
1848 need it again soon. */
1849 while (displaced
->step_request_queue
)
1851 struct displaced_step_request
*head
;
1853 struct regcache
*regcache
;
1854 struct gdbarch
*gdbarch
;
1855 CORE_ADDR actual_pc
;
1856 struct address_space
*aspace
;
1858 head
= displaced
->step_request_queue
;
1860 displaced
->step_request_queue
= head
->next
;
1863 context_switch (ptid
);
1865 regcache
= get_thread_regcache (ptid
);
1866 actual_pc
= regcache_read_pc (regcache
);
1867 aspace
= get_regcache_aspace (regcache
);
1868 gdbarch
= get_regcache_arch (regcache
);
1870 if (breakpoint_here_p (aspace
, actual_pc
))
1872 if (debug_displaced
)
1873 fprintf_unfiltered (gdb_stdlog
,
1874 "displaced: stepping queued %s now\n",
1875 target_pid_to_str (ptid
));
1877 displaced_step_prepare (ptid
);
1879 if (debug_displaced
)
1881 CORE_ADDR actual_pc
= regcache_read_pc (regcache
);
1884 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
1885 paddress (gdbarch
, actual_pc
));
1886 read_memory (actual_pc
, buf
, sizeof (buf
));
1887 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
1890 if (gdbarch_displaced_step_hw_singlestep (gdbarch
,
1891 displaced
->step_closure
))
1892 target_resume (ptid
, 1, GDB_SIGNAL_0
);
1894 target_resume (ptid
, 0, GDB_SIGNAL_0
);
1896 /* Done, we're stepping a thread. */
1902 struct thread_info
*tp
= inferior_thread ();
1904 /* The breakpoint we were sitting under has since been
1906 tp
->control
.trap_expected
= 0;
1908 /* Go back to what we were trying to do. */
1909 step
= currently_stepping (tp
);
1912 step
= maybe_software_singlestep (gdbarch
, actual_pc
);
1914 if (debug_displaced
)
1915 fprintf_unfiltered (gdb_stdlog
,
1916 "displaced: breakpoint is gone: %s, step(%d)\n",
1917 target_pid_to_str (tp
->ptid
), step
);
1919 target_resume (ptid
, step
, GDB_SIGNAL_0
);
1920 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1922 /* This request was discarded. See if there's any other
1923 thread waiting for its turn. */
1928 /* Update global variables holding ptids to hold NEW_PTID if they were
1929 holding OLD_PTID. */
1931 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
1933 struct displaced_step_request
*it
;
1934 struct displaced_step_inferior_state
*displaced
;
1936 if (ptid_equal (inferior_ptid
, old_ptid
))
1937 inferior_ptid
= new_ptid
;
1939 for (displaced
= displaced_step_inferior_states
;
1941 displaced
= displaced
->next
)
1943 if (ptid_equal (displaced
->step_ptid
, old_ptid
))
1944 displaced
->step_ptid
= new_ptid
;
1946 for (it
= displaced
->step_request_queue
; it
; it
= it
->next
)
1947 if (ptid_equal (it
->ptid
, old_ptid
))
1948 it
->ptid
= new_ptid
;
1955 /* Things to clean up if we QUIT out of resume (). */
1957 resume_cleanups (void *ignore
)
1959 if (!ptid_equal (inferior_ptid
, null_ptid
))
1960 delete_single_step_breakpoints (inferior_thread ());
1965 static const char schedlock_off
[] = "off";
1966 static const char schedlock_on
[] = "on";
1967 static const char schedlock_step
[] = "step";
1968 static const char *const scheduler_enums
[] = {
1974 static const char *scheduler_mode
= schedlock_off
;
1976 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
1977 struct cmd_list_element
*c
, const char *value
)
1979 fprintf_filtered (file
,
1980 _("Mode for locking scheduler "
1981 "during execution is \"%s\".\n"),
1986 set_schedlock_func (char *args
, int from_tty
, struct cmd_list_element
*c
)
1988 if (!target_can_lock_scheduler
)
1990 scheduler_mode
= schedlock_off
;
1991 error (_("Target '%s' cannot support this command."), target_shortname
);
1995 /* True if execution commands resume all threads of all processes by
1996 default; otherwise, resume only threads of the current inferior
1998 int sched_multi
= 0;
2000 /* Try to setup for software single stepping over the specified location.
2001 Return 1 if target_resume() should use hardware single step.
2003 GDBARCH the current gdbarch.
2004 PC the location to step over. */
2007 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2011 if (execution_direction
== EXEC_FORWARD
2012 && gdbarch_software_single_step_p (gdbarch
)
2013 && gdbarch_software_single_step (gdbarch
, get_current_frame ()))
2023 user_visible_resume_ptid (int step
)
2029 /* With non-stop mode on, threads are always handled
2031 resume_ptid
= inferior_ptid
;
2033 else if ((scheduler_mode
== schedlock_on
)
2034 || (scheduler_mode
== schedlock_step
&& step
))
2036 /* User-settable 'scheduler' mode requires solo thread
2038 resume_ptid
= inferior_ptid
;
2040 else if (!sched_multi
&& target_supports_multi_process ())
2042 /* Resume all threads of the current process (and none of other
2044 resume_ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
2048 /* Resume all threads of all processes. */
2049 resume_ptid
= RESUME_ALL
;
2055 /* Wrapper for target_resume, that handles infrun-specific
2059 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2061 struct thread_info
*tp
= inferior_thread ();
2063 /* Install inferior's terminal modes. */
2064 target_terminal_inferior ();
2066 /* Avoid confusing the next resume, if the next stop/resume
2067 happens to apply to another thread. */
2068 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2070 /* Advise target which signals may be handled silently.
2072 If we have removed breakpoints because we are stepping over one
2073 in-line (in any thread), we need to receive all signals to avoid
2074 accidentally skipping a breakpoint during execution of a signal
2077 Likewise if we're displaced stepping, otherwise a trap for a
2078 breakpoint in a signal handler might be confused with the
2079 displaced step finishing. We don't make the displaced_step_fixup
2080 step distinguish the cases instead, because:
2082 - a backtrace while stopped in the signal handler would show the
2083 scratch pad as frame older than the signal handler, instead of
2084 the real mainline code.
2086 - when the thread is later resumed, the signal handler would
2087 return to the scratch pad area, which would no longer be
2089 if (step_over_info_valid_p ()
2090 || displaced_step_in_progress (ptid_get_pid (tp
->ptid
)))
2091 target_pass_signals (0, NULL
);
2093 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
2095 target_resume (resume_ptid
, step
, sig
);
2098 /* Resume the inferior, but allow a QUIT. This is useful if the user
2099 wants to interrupt some lengthy single-stepping operation
2100 (for child processes, the SIGINT goes to the inferior, and so
2101 we get a SIGINT random_signal, but for remote debugging and perhaps
2102 other targets, that's not true).
2104 SIG is the signal to give the inferior (zero for none). */
2106 resume (enum gdb_signal sig
)
2108 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
2109 struct regcache
*regcache
= get_current_regcache ();
2110 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2111 struct thread_info
*tp
= inferior_thread ();
2112 CORE_ADDR pc
= regcache_read_pc (regcache
);
2113 struct address_space
*aspace
= get_regcache_aspace (regcache
);
2115 /* This represents the user's step vs continue request. When
2116 deciding whether "set scheduler-locking step" applies, it's the
2117 user's intention that counts. */
2118 const int user_step
= tp
->control
.stepping_command
;
2119 /* This represents what we'll actually request the target to do.
2120 This can decay from a step to a continue, if e.g., we need to
2121 implement single-stepping with breakpoints (software
2125 tp
->stepped_breakpoint
= 0;
2129 /* Depends on stepped_breakpoint. */
2130 step
= currently_stepping (tp
);
2132 if (current_inferior ()->waiting_for_vfork_done
)
2134 /* Don't try to single-step a vfork parent that is waiting for
2135 the child to get out of the shared memory region (by exec'ing
2136 or exiting). This is particularly important on software
2137 single-step archs, as the child process would trip on the
2138 software single step breakpoint inserted for the parent
2139 process. Since the parent will not actually execute any
2140 instruction until the child is out of the shared region (such
2141 are vfork's semantics), it is safe to simply continue it.
2142 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2143 the parent, and tell it to `keep_going', which automatically
2144 re-sets it stepping. */
2146 fprintf_unfiltered (gdb_stdlog
,
2147 "infrun: resume : clear step\n");
2152 fprintf_unfiltered (gdb_stdlog
,
2153 "infrun: resume (step=%d, signal=%s), "
2154 "trap_expected=%d, current thread [%s] at %s\n",
2155 step
, gdb_signal_to_symbol_string (sig
),
2156 tp
->control
.trap_expected
,
2157 target_pid_to_str (inferior_ptid
),
2158 paddress (gdbarch
, pc
));
2160 /* Normally, by the time we reach `resume', the breakpoints are either
2161 removed or inserted, as appropriate. The exception is if we're sitting
2162 at a permanent breakpoint; we need to step over it, but permanent
2163 breakpoints can't be removed. So we have to test for it here. */
2164 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2166 if (sig
!= GDB_SIGNAL_0
)
2168 /* We have a signal to pass to the inferior. The resume
2169 may, or may not take us to the signal handler. If this
2170 is a step, we'll need to stop in the signal handler, if
2171 there's one, (if the target supports stepping into
2172 handlers), or in the next mainline instruction, if
2173 there's no handler. If this is a continue, we need to be
2174 sure to run the handler with all breakpoints inserted.
2175 In all cases, set a breakpoint at the current address
2176 (where the handler returns to), and once that breakpoint
2177 is hit, resume skipping the permanent breakpoint. If
2178 that breakpoint isn't hit, then we've stepped into the
2179 signal handler (or hit some other event). We'll delete
2180 the step-resume breakpoint then. */
2183 fprintf_unfiltered (gdb_stdlog
,
2184 "infrun: resume: skipping permanent breakpoint, "
2185 "deliver signal first\n");
2187 clear_step_over_info ();
2188 tp
->control
.trap_expected
= 0;
2190 if (tp
->control
.step_resume_breakpoint
== NULL
)
2192 /* Set a "high-priority" step-resume, as we don't want
2193 user breakpoints at PC to trigger (again) when this
2195 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2196 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2198 tp
->step_after_step_resume_breakpoint
= step
;
2201 insert_breakpoints ();
2205 /* There's no signal to pass, we can go ahead and skip the
2206 permanent breakpoint manually. */
2208 fprintf_unfiltered (gdb_stdlog
,
2209 "infrun: resume: skipping permanent breakpoint\n");
2210 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2211 /* Update pc to reflect the new address from which we will
2212 execute instructions. */
2213 pc
= regcache_read_pc (regcache
);
2217 /* We've already advanced the PC, so the stepping part
2218 is done. Now we need to arrange for a trap to be
2219 reported to handle_inferior_event. Set a breakpoint
2220 at the current PC, and run to it. Don't update
2221 prev_pc, because if we end in
2222 switch_back_to_stepped_thread, we want the "expected
2223 thread advanced also" branch to be taken. IOW, we
2224 don't want this thread to step further from PC
2226 gdb_assert (!step_over_info_valid_p ());
2227 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2228 insert_breakpoints ();
2230 resume_ptid
= user_visible_resume_ptid (user_step
);
2231 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2232 discard_cleanups (old_cleanups
);
2238 /* If we have a breakpoint to step over, make sure to do a single
2239 step only. Same if we have software watchpoints. */
2240 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2241 tp
->control
.may_range_step
= 0;
2243 /* If enabled, step over breakpoints by executing a copy of the
2244 instruction at a different address.
2246 We can't use displaced stepping when we have a signal to deliver;
2247 the comments for displaced_step_prepare explain why. The
2248 comments in the handle_inferior event for dealing with 'random
2249 signals' explain what we do instead.
2251 We can't use displaced stepping when we are waiting for vfork_done
2252 event, displaced stepping breaks the vfork child similarly as single
2253 step software breakpoint. */
2254 if (use_displaced_stepping (gdbarch
)
2255 && tp
->control
.trap_expected
2256 && !step_over_info_valid_p ()
2257 && sig
== GDB_SIGNAL_0
2258 && !current_inferior ()->waiting_for_vfork_done
)
2260 struct displaced_step_inferior_state
*displaced
;
2262 if (!displaced_step_prepare (inferior_ptid
))
2264 /* Got placed in displaced stepping queue. Will be resumed
2265 later when all the currently queued displaced stepping
2266 requests finish. The thread is not executing at this
2267 point, and the call to set_executing will be made later.
2268 But we need to call set_running here, since from the
2269 user/frontend's point of view, threads were set running.
2270 Unless we're calling an inferior function, as in that
2271 case we pretend the inferior doesn't run at all. */
2272 if (!tp
->control
.in_infcall
)
2273 set_running (user_visible_resume_ptid (user_step
), 1);
2274 discard_cleanups (old_cleanups
);
2278 /* Update pc to reflect the new address from which we will execute
2279 instructions due to displaced stepping. */
2280 pc
= regcache_read_pc (get_thread_regcache (inferior_ptid
));
2282 displaced
= get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
2283 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2284 displaced
->step_closure
);
2287 /* Do we need to do it the hard way, w/temp breakpoints? */
2289 step
= maybe_software_singlestep (gdbarch
, pc
);
2291 /* Currently, our software single-step implementation leads to different
2292 results than hardware single-stepping in one situation: when stepping
2293 into delivering a signal which has an associated signal handler,
2294 hardware single-step will stop at the first instruction of the handler,
2295 while software single-step will simply skip execution of the handler.
2297 For now, this difference in behavior is accepted since there is no
2298 easy way to actually implement single-stepping into a signal handler
2299 without kernel support.
2301 However, there is one scenario where this difference leads to follow-on
2302 problems: if we're stepping off a breakpoint by removing all breakpoints
2303 and then single-stepping. In this case, the software single-step
2304 behavior means that even if there is a *breakpoint* in the signal
2305 handler, GDB still would not stop.
2307 Fortunately, we can at least fix this particular issue. We detect
2308 here the case where we are about to deliver a signal while software
2309 single-stepping with breakpoints removed. In this situation, we
2310 revert the decisions to remove all breakpoints and insert single-
2311 step breakpoints, and instead we install a step-resume breakpoint
2312 at the current address, deliver the signal without stepping, and
2313 once we arrive back at the step-resume breakpoint, actually step
2314 over the breakpoint we originally wanted to step over. */
2315 if (thread_has_single_step_breakpoints_set (tp
)
2316 && sig
!= GDB_SIGNAL_0
2317 && step_over_info_valid_p ())
2319 /* If we have nested signals or a pending signal is delivered
2320 immediately after a handler returns, might might already have
2321 a step-resume breakpoint set on the earlier handler. We cannot
2322 set another step-resume breakpoint; just continue on until the
2323 original breakpoint is hit. */
2324 if (tp
->control
.step_resume_breakpoint
== NULL
)
2326 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2327 tp
->step_after_step_resume_breakpoint
= 1;
2330 delete_single_step_breakpoints (tp
);
2332 clear_step_over_info ();
2333 tp
->control
.trap_expected
= 0;
2335 insert_breakpoints ();
2338 /* If STEP is set, it's a request to use hardware stepping
2339 facilities. But in that case, we should never
2340 use singlestep breakpoint. */
2341 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2343 /* Decide the set of threads to ask the target to resume. Start
2344 by assuming everything will be resumed, than narrow the set
2345 by applying increasingly restricting conditions. */
2346 resume_ptid
= user_visible_resume_ptid (user_step
);
2348 /* Even if RESUME_PTID is a wildcard, and we end up resuming less
2349 (e.g., we might need to step over a breakpoint), from the
2350 user/frontend's point of view, all threads in RESUME_PTID are now
2351 running. Unless we're calling an inferior function, as in that
2352 case pretend we inferior doesn't run at all. */
2353 if (!tp
->control
.in_infcall
)
2354 set_running (resume_ptid
, 1);
2356 /* Maybe resume a single thread after all. */
2357 if ((step
|| thread_has_single_step_breakpoints_set (tp
))
2358 && tp
->control
.trap_expected
)
2360 /* We're allowing a thread to run past a breakpoint it has
2361 hit, by single-stepping the thread with the breakpoint
2362 removed. In which case, we need to single-step only this
2363 thread, and keep others stopped, as they can miss this
2364 breakpoint if allowed to run. */
2365 resume_ptid
= inferior_ptid
;
2368 if (execution_direction
!= EXEC_REVERSE
2369 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2371 /* The only case we currently need to step a breakpoint
2372 instruction is when we have a signal to deliver. See
2373 handle_signal_stop where we handle random signals that could
2374 take out us out of the stepping range. Normally, in that
2375 case we end up continuing (instead of stepping) over the
2376 signal handler with a breakpoint at PC, but there are cases
2377 where we should _always_ single-step, even if we have a
2378 step-resume breakpoint, like when a software watchpoint is
2379 set. Assuming single-stepping and delivering a signal at the
2380 same time would takes us to the signal handler, then we could
2381 have removed the breakpoint at PC to step over it. However,
2382 some hardware step targets (like e.g., Mac OS) can't step
2383 into signal handlers, and for those, we need to leave the
2384 breakpoint at PC inserted, as otherwise if the handler
2385 recurses and executes PC again, it'll miss the breakpoint.
2386 So we leave the breakpoint inserted anyway, but we need to
2387 record that we tried to step a breakpoint instruction, so
2388 that adjust_pc_after_break doesn't end up confused. */
2389 gdb_assert (sig
!= GDB_SIGNAL_0
);
2391 tp
->stepped_breakpoint
= 1;
2393 /* Most targets can step a breakpoint instruction, thus
2394 executing it normally. But if this one cannot, just
2395 continue and we will hit it anyway. */
2396 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2401 && use_displaced_stepping (gdbarch
)
2402 && tp
->control
.trap_expected
2403 && !step_over_info_valid_p ())
2405 struct regcache
*resume_regcache
= get_thread_regcache (tp
->ptid
);
2406 struct gdbarch
*resume_gdbarch
= get_regcache_arch (resume_regcache
);
2407 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2410 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2411 paddress (resume_gdbarch
, actual_pc
));
2412 read_memory (actual_pc
, buf
, sizeof (buf
));
2413 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2416 if (tp
->control
.may_range_step
)
2418 /* If we're resuming a thread with the PC out of the step
2419 range, then we're doing some nested/finer run control
2420 operation, like stepping the thread out of the dynamic
2421 linker or the displaced stepping scratch pad. We
2422 shouldn't have allowed a range step then. */
2423 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2426 do_target_resume (resume_ptid
, step
, sig
);
2427 discard_cleanups (old_cleanups
);
2432 /* Clear out all variables saying what to do when inferior is continued.
2433 First do this, then set the ones you want, then call `proceed'. */
2436 clear_proceed_status_thread (struct thread_info
*tp
)
2439 fprintf_unfiltered (gdb_stdlog
,
2440 "infrun: clear_proceed_status_thread (%s)\n",
2441 target_pid_to_str (tp
->ptid
));
2443 /* If this signal should not be seen by program, give it zero.
2444 Used for debugging signals. */
2445 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2446 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2448 tp
->control
.trap_expected
= 0;
2449 tp
->control
.step_range_start
= 0;
2450 tp
->control
.step_range_end
= 0;
2451 tp
->control
.may_range_step
= 0;
2452 tp
->control
.step_frame_id
= null_frame_id
;
2453 tp
->control
.step_stack_frame_id
= null_frame_id
;
2454 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2455 tp
->control
.step_start_function
= NULL
;
2456 tp
->stop_requested
= 0;
2458 tp
->control
.stop_step
= 0;
2460 tp
->control
.proceed_to_finish
= 0;
2462 tp
->control
.command_interp
= NULL
;
2463 tp
->control
.stepping_command
= 0;
2465 /* Discard any remaining commands or status from previous stop. */
2466 bpstat_clear (&tp
->control
.stop_bpstat
);
2470 clear_proceed_status (int step
)
2474 struct thread_info
*tp
;
2477 resume_ptid
= user_visible_resume_ptid (step
);
2479 /* In all-stop mode, delete the per-thread status of all threads
2480 we're about to resume, implicitly and explicitly. */
2481 ALL_NON_EXITED_THREADS (tp
)
2483 if (!ptid_match (tp
->ptid
, resume_ptid
))
2485 clear_proceed_status_thread (tp
);
2489 if (!ptid_equal (inferior_ptid
, null_ptid
))
2491 struct inferior
*inferior
;
2495 /* If in non-stop mode, only delete the per-thread status of
2496 the current thread. */
2497 clear_proceed_status_thread (inferior_thread ());
2500 inferior
= current_inferior ();
2501 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2504 stop_after_trap
= 0;
2506 clear_step_over_info ();
2508 observer_notify_about_to_proceed ();
2512 regcache_xfree (stop_registers
);
2513 stop_registers
= NULL
;
2517 /* Returns true if TP is still stopped at a breakpoint that needs
2518 stepping-over in order to make progress. If the breakpoint is gone
2519 meanwhile, we can skip the whole step-over dance. */
2522 thread_still_needs_step_over (struct thread_info
*tp
)
2524 if (tp
->stepping_over_breakpoint
)
2526 struct regcache
*regcache
= get_thread_regcache (tp
->ptid
);
2528 if (breakpoint_here_p (get_regcache_aspace (regcache
),
2529 regcache_read_pc (regcache
))
2530 == ordinary_breakpoint_here
)
2533 tp
->stepping_over_breakpoint
= 0;
2539 /* Returns true if scheduler locking applies. STEP indicates whether
2540 we're about to do a step/next-like command to a thread. */
2543 schedlock_applies (struct thread_info
*tp
)
2545 return (scheduler_mode
== schedlock_on
2546 || (scheduler_mode
== schedlock_step
2547 && tp
->control
.stepping_command
));
2550 /* Look a thread other than EXCEPT that has previously reported a
2551 breakpoint event, and thus needs a step-over in order to make
2552 progress. Returns NULL is none is found. */
2554 static struct thread_info
*
2555 find_thread_needs_step_over (struct thread_info
*except
)
2557 struct thread_info
*tp
, *current
;
2559 /* With non-stop mode on, threads are always handled individually. */
2560 gdb_assert (! non_stop
);
2562 current
= inferior_thread ();
2564 /* If scheduler locking applies, we can avoid iterating over all
2566 if (schedlock_applies (except
))
2568 if (except
!= current
2569 && thread_still_needs_step_over (current
))
2575 ALL_NON_EXITED_THREADS (tp
)
2577 /* Ignore the EXCEPT thread. */
2580 /* Ignore threads of processes we're not resuming. */
2582 && ptid_get_pid (tp
->ptid
) != ptid_get_pid (inferior_ptid
))
2585 if (thread_still_needs_step_over (tp
))
2592 /* Basic routine for continuing the program in various fashions.
2594 ADDR is the address to resume at, or -1 for resume where stopped.
2595 SIGGNAL is the signal to give it, or 0 for none,
2596 or -1 for act according to how it stopped.
2597 STEP is nonzero if should trap after one instruction.
2598 -1 means return after that and print nothing.
2599 You should probably set various step_... variables
2600 before calling here, if you are stepping.
2602 You should call clear_proceed_status before calling proceed. */
2605 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2607 struct regcache
*regcache
;
2608 struct gdbarch
*gdbarch
;
2609 struct thread_info
*tp
;
2611 struct address_space
*aspace
;
2613 /* If we're stopped at a fork/vfork, follow the branch set by the
2614 "set follow-fork-mode" command; otherwise, we'll just proceed
2615 resuming the current thread. */
2616 if (!follow_fork ())
2618 /* The target for some reason decided not to resume. */
2620 if (target_can_async_p ())
2621 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2625 /* We'll update this if & when we switch to a new thread. */
2626 previous_inferior_ptid
= inferior_ptid
;
2628 regcache
= get_current_regcache ();
2629 gdbarch
= get_regcache_arch (regcache
);
2630 aspace
= get_regcache_aspace (regcache
);
2631 pc
= regcache_read_pc (regcache
);
2632 tp
= inferior_thread ();
2634 /* Fill in with reasonable starting values. */
2635 init_thread_stepping_state (tp
);
2637 if (addr
== (CORE_ADDR
) -1)
2640 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2641 && execution_direction
!= EXEC_REVERSE
)
2642 /* There is a breakpoint at the address we will resume at,
2643 step one instruction before inserting breakpoints so that
2644 we do not stop right away (and report a second hit at this
2647 Note, we don't do this in reverse, because we won't
2648 actually be executing the breakpoint insn anyway.
2649 We'll be (un-)executing the previous instruction. */
2650 tp
->stepping_over_breakpoint
= 1;
2651 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2652 && gdbarch_single_step_through_delay (gdbarch
,
2653 get_current_frame ()))
2654 /* We stepped onto an instruction that needs to be stepped
2655 again before re-inserting the breakpoint, do so. */
2656 tp
->stepping_over_breakpoint
= 1;
2660 regcache_write_pc (regcache
, addr
);
2663 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2664 tp
->suspend
.stop_signal
= siggnal
;
2666 /* Record the interpreter that issued the execution command that
2667 caused this thread to resume. If the top level interpreter is
2668 MI/async, and the execution command was a CLI command
2669 (next/step/etc.), we'll want to print stop event output to the MI
2670 console channel (the stepped-to line, etc.), as if the user
2671 entered the execution command on a real GDB console. */
2672 inferior_thread ()->control
.command_interp
= command_interp ();
2675 fprintf_unfiltered (gdb_stdlog
,
2676 "infrun: proceed (addr=%s, signal=%s)\n",
2677 paddress (gdbarch
, addr
),
2678 gdb_signal_to_symbol_string (siggnal
));
2681 /* In non-stop, each thread is handled individually. The context
2682 must already be set to the right thread here. */
2686 struct thread_info
*step_over
;
2688 /* In a multi-threaded task we may select another thread and
2689 then continue or step.
2691 But if the old thread was stopped at a breakpoint, it will
2692 immediately cause another breakpoint stop without any
2693 execution (i.e. it will report a breakpoint hit incorrectly).
2694 So we must step over it first.
2696 Look for a thread other than the current (TP) that reported a
2697 breakpoint hit and hasn't been resumed yet since. */
2698 step_over
= find_thread_needs_step_over (tp
);
2699 if (step_over
!= NULL
)
2702 fprintf_unfiltered (gdb_stdlog
,
2703 "infrun: need to step-over [%s] first\n",
2704 target_pid_to_str (step_over
->ptid
));
2706 /* Store the prev_pc for the stepping thread too, needed by
2707 switch_back_to_stepped_thread. */
2708 tp
->prev_pc
= regcache_read_pc (get_current_regcache ());
2709 switch_to_thread (step_over
->ptid
);
2714 /* If we need to step over a breakpoint, and we're not using
2715 displaced stepping to do so, insert all breakpoints (watchpoints,
2716 etc.) but the one we're stepping over, step one instruction, and
2717 then re-insert the breakpoint when that step is finished. */
2718 if (tp
->stepping_over_breakpoint
&& !use_displaced_stepping (gdbarch
))
2720 struct regcache
*regcache
= get_current_regcache ();
2722 set_step_over_info (get_regcache_aspace (regcache
),
2723 regcache_read_pc (regcache
), 0);
2726 clear_step_over_info ();
2728 insert_breakpoints ();
2730 tp
->control
.trap_expected
= tp
->stepping_over_breakpoint
;
2732 annotate_starting ();
2734 /* Make sure that output from GDB appears before output from the
2736 gdb_flush (gdb_stdout
);
2738 /* Refresh prev_pc value just prior to resuming. This used to be
2739 done in stop_waiting, however, setting prev_pc there did not handle
2740 scenarios such as inferior function calls or returning from
2741 a function via the return command. In those cases, the prev_pc
2742 value was not set properly for subsequent commands. The prev_pc value
2743 is used to initialize the starting line number in the ecs. With an
2744 invalid value, the gdb next command ends up stopping at the position
2745 represented by the next line table entry past our start position.
2746 On platforms that generate one line table entry per line, this
2747 is not a problem. However, on the ia64, the compiler generates
2748 extraneous line table entries that do not increase the line number.
2749 When we issue the gdb next command on the ia64 after an inferior call
2750 or a return command, we often end up a few instructions forward, still
2751 within the original line we started.
2753 An attempt was made to refresh the prev_pc at the same time the
2754 execution_control_state is initialized (for instance, just before
2755 waiting for an inferior event). But this approach did not work
2756 because of platforms that use ptrace, where the pc register cannot
2757 be read unless the inferior is stopped. At that point, we are not
2758 guaranteed the inferior is stopped and so the regcache_read_pc() call
2759 can fail. Setting the prev_pc value here ensures the value is updated
2760 correctly when the inferior is stopped. */
2761 tp
->prev_pc
= regcache_read_pc (get_current_regcache ());
2763 /* Resume inferior. */
2764 resume (tp
->suspend
.stop_signal
);
2766 /* Wait for it to stop (if not standalone)
2767 and in any case decode why it stopped, and act accordingly. */
2768 /* Do this only if we are not using the event loop, or if the target
2769 does not support asynchronous execution. */
2770 if (!target_can_async_p ())
2772 wait_for_inferior ();
2778 /* Start remote-debugging of a machine over a serial link. */
2781 start_remote (int from_tty
)
2783 struct inferior
*inferior
;
2785 inferior
= current_inferior ();
2786 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
2788 /* Always go on waiting for the target, regardless of the mode. */
2789 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2790 indicate to wait_for_inferior that a target should timeout if
2791 nothing is returned (instead of just blocking). Because of this,
2792 targets expecting an immediate response need to, internally, set
2793 things up so that the target_wait() is forced to eventually
2795 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2796 differentiate to its caller what the state of the target is after
2797 the initial open has been performed. Here we're assuming that
2798 the target has stopped. It should be possible to eventually have
2799 target_open() return to the caller an indication that the target
2800 is currently running and GDB state should be set to the same as
2801 for an async run. */
2802 wait_for_inferior ();
2804 /* Now that the inferior has stopped, do any bookkeeping like
2805 loading shared libraries. We want to do this before normal_stop,
2806 so that the displayed frame is up to date. */
2807 post_create_inferior (¤t_target
, from_tty
);
2812 /* Initialize static vars when a new inferior begins. */
2815 init_wait_for_inferior (void)
2817 /* These are meaningless until the first time through wait_for_inferior. */
2819 breakpoint_init_inferior (inf_starting
);
2821 clear_proceed_status (0);
2823 target_last_wait_ptid
= minus_one_ptid
;
2825 previous_inferior_ptid
= inferior_ptid
;
2827 /* Discard any skipped inlined frames. */
2828 clear_inline_frame_state (minus_one_ptid
);
2832 /* Data to be passed around while handling an event. This data is
2833 discarded between events. */
2834 struct execution_control_state
2837 /* The thread that got the event, if this was a thread event; NULL
2839 struct thread_info
*event_thread
;
2841 struct target_waitstatus ws
;
2842 int stop_func_filled_in
;
2843 CORE_ADDR stop_func_start
;
2844 CORE_ADDR stop_func_end
;
2845 const char *stop_func_name
;
2848 /* True if the event thread hit the single-step breakpoint of
2849 another thread. Thus the event doesn't cause a stop, the thread
2850 needs to be single-stepped past the single-step breakpoint before
2851 we can switch back to the original stepping thread. */
2852 int hit_singlestep_breakpoint
;
2855 static void handle_inferior_event (struct execution_control_state
*ecs
);
2857 static void handle_step_into_function (struct gdbarch
*gdbarch
,
2858 struct execution_control_state
*ecs
);
2859 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
2860 struct execution_control_state
*ecs
);
2861 static void handle_signal_stop (struct execution_control_state
*ecs
);
2862 static void check_exception_resume (struct execution_control_state
*,
2863 struct frame_info
*);
2865 static void end_stepping_range (struct execution_control_state
*ecs
);
2866 static void stop_waiting (struct execution_control_state
*ecs
);
2867 static void prepare_to_wait (struct execution_control_state
*ecs
);
2868 static void keep_going (struct execution_control_state
*ecs
);
2869 static void process_event_stop_test (struct execution_control_state
*ecs
);
2870 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
2872 /* Callback for iterate over threads. If the thread is stopped, but
2873 the user/frontend doesn't know about that yet, go through
2874 normal_stop, as if the thread had just stopped now. ARG points at
2875 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2876 ptid_is_pid(PTID) is true, applies to all threads of the process
2877 pointed at by PTID. Otherwise, apply only to the thread pointed by
2881 infrun_thread_stop_requested_callback (struct thread_info
*info
, void *arg
)
2883 ptid_t ptid
= * (ptid_t
*) arg
;
2885 if ((ptid_equal (info
->ptid
, ptid
)
2886 || ptid_equal (minus_one_ptid
, ptid
)
2887 || (ptid_is_pid (ptid
)
2888 && ptid_get_pid (ptid
) == ptid_get_pid (info
->ptid
)))
2889 && is_running (info
->ptid
)
2890 && !is_executing (info
->ptid
))
2892 struct cleanup
*old_chain
;
2893 struct execution_control_state ecss
;
2894 struct execution_control_state
*ecs
= &ecss
;
2896 memset (ecs
, 0, sizeof (*ecs
));
2898 old_chain
= make_cleanup_restore_current_thread ();
2900 overlay_cache_invalid
= 1;
2901 /* Flush target cache before starting to handle each event.
2902 Target was running and cache could be stale. This is just a
2903 heuristic. Running threads may modify target memory, but we
2904 don't get any event. */
2905 target_dcache_invalidate ();
2907 /* Go through handle_inferior_event/normal_stop, so we always
2908 have consistent output as if the stop event had been
2910 ecs
->ptid
= info
->ptid
;
2911 ecs
->event_thread
= find_thread_ptid (info
->ptid
);
2912 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
2913 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
2915 handle_inferior_event (ecs
);
2917 if (!ecs
->wait_some_more
)
2919 struct thread_info
*tp
;
2923 /* Finish off the continuations. */
2924 tp
= inferior_thread ();
2925 do_all_intermediate_continuations_thread (tp
, 1);
2926 do_all_continuations_thread (tp
, 1);
2929 do_cleanups (old_chain
);
2935 /* This function is attached as a "thread_stop_requested" observer.
2936 Cleanup local state that assumed the PTID was to be resumed, and
2937 report the stop to the frontend. */
2940 infrun_thread_stop_requested (ptid_t ptid
)
2942 struct displaced_step_inferior_state
*displaced
;
2944 /* PTID was requested to stop. Remove it from the displaced
2945 stepping queue, so we don't try to resume it automatically. */
2947 for (displaced
= displaced_step_inferior_states
;
2949 displaced
= displaced
->next
)
2951 struct displaced_step_request
*it
, **prev_next_p
;
2953 it
= displaced
->step_request_queue
;
2954 prev_next_p
= &displaced
->step_request_queue
;
2957 if (ptid_match (it
->ptid
, ptid
))
2959 *prev_next_p
= it
->next
;
2965 prev_next_p
= &it
->next
;
2972 iterate_over_threads (infrun_thread_stop_requested_callback
, &ptid
);
2976 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
2978 if (ptid_equal (target_last_wait_ptid
, tp
->ptid
))
2979 nullify_last_target_wait_ptid ();
2982 /* Delete the step resume, single-step and longjmp/exception resume
2983 breakpoints of TP. */
2986 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
2988 delete_step_resume_breakpoint (tp
);
2989 delete_exception_resume_breakpoint (tp
);
2990 delete_single_step_breakpoints (tp
);
2993 /* If the target still has execution, call FUNC for each thread that
2994 just stopped. In all-stop, that's all the non-exited threads; in
2995 non-stop, that's the current thread, only. */
2997 typedef void (*for_each_just_stopped_thread_callback_func
)
2998 (struct thread_info
*tp
);
3001 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3003 if (!target_has_execution
|| ptid_equal (inferior_ptid
, null_ptid
))
3008 /* If in non-stop mode, only the current thread stopped. */
3009 func (inferior_thread ());
3013 struct thread_info
*tp
;
3015 /* In all-stop mode, all threads have stopped. */
3016 ALL_NON_EXITED_THREADS (tp
)
3023 /* Delete the step resume and longjmp/exception resume breakpoints of
3024 the threads that just stopped. */
3027 delete_just_stopped_threads_infrun_breakpoints (void)
3029 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3032 /* Delete the single-step breakpoints of the threads that just
3036 delete_just_stopped_threads_single_step_breakpoints (void)
3038 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3041 /* A cleanup wrapper. */
3044 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg
)
3046 delete_just_stopped_threads_infrun_breakpoints ();
3049 /* Pretty print the results of target_wait, for debugging purposes. */
3052 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3053 const struct target_waitstatus
*ws
)
3055 char *status_string
= target_waitstatus_to_string (ws
);
3056 struct ui_file
*tmp_stream
= mem_fileopen ();
3059 /* The text is split over several lines because it was getting too long.
3060 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3061 output as a unit; we want only one timestamp printed if debug_timestamp
3064 fprintf_unfiltered (tmp_stream
,
3065 "infrun: target_wait (%d.%ld.%ld",
3066 ptid_get_pid (waiton_ptid
),
3067 ptid_get_lwp (waiton_ptid
),
3068 ptid_get_tid (waiton_ptid
));
3069 if (ptid_get_pid (waiton_ptid
) != -1)
3070 fprintf_unfiltered (tmp_stream
,
3071 " [%s]", target_pid_to_str (waiton_ptid
));
3072 fprintf_unfiltered (tmp_stream
, ", status) =\n");
3073 fprintf_unfiltered (tmp_stream
,
3074 "infrun: %d.%ld.%ld [%s],\n",
3075 ptid_get_pid (result_ptid
),
3076 ptid_get_lwp (result_ptid
),
3077 ptid_get_tid (result_ptid
),
3078 target_pid_to_str (result_ptid
));
3079 fprintf_unfiltered (tmp_stream
,
3083 text
= ui_file_xstrdup (tmp_stream
, NULL
);
3085 /* This uses %s in part to handle %'s in the text, but also to avoid
3086 a gcc error: the format attribute requires a string literal. */
3087 fprintf_unfiltered (gdb_stdlog
, "%s", text
);
3089 xfree (status_string
);
3091 ui_file_delete (tmp_stream
);
3094 /* Prepare and stabilize the inferior for detaching it. E.g.,
3095 detaching while a thread is displaced stepping is a recipe for
3096 crashing it, as nothing would readjust the PC out of the scratch
3100 prepare_for_detach (void)
3102 struct inferior
*inf
= current_inferior ();
3103 ptid_t pid_ptid
= pid_to_ptid (inf
->pid
);
3104 struct cleanup
*old_chain_1
;
3105 struct displaced_step_inferior_state
*displaced
;
3107 displaced
= get_displaced_stepping_state (inf
->pid
);
3109 /* Is any thread of this process displaced stepping? If not,
3110 there's nothing else to do. */
3111 if (displaced
== NULL
|| ptid_equal (displaced
->step_ptid
, null_ptid
))
3115 fprintf_unfiltered (gdb_stdlog
,
3116 "displaced-stepping in-process while detaching");
3118 old_chain_1
= make_cleanup_restore_integer (&inf
->detaching
);
3121 while (!ptid_equal (displaced
->step_ptid
, null_ptid
))
3123 struct cleanup
*old_chain_2
;
3124 struct execution_control_state ecss
;
3125 struct execution_control_state
*ecs
;
3128 memset (ecs
, 0, sizeof (*ecs
));
3130 overlay_cache_invalid
= 1;
3131 /* Flush target cache before starting to handle each event.
3132 Target was running and cache could be stale. This is just a
3133 heuristic. Running threads may modify target memory, but we
3134 don't get any event. */
3135 target_dcache_invalidate ();
3137 if (deprecated_target_wait_hook
)
3138 ecs
->ptid
= deprecated_target_wait_hook (pid_ptid
, &ecs
->ws
, 0);
3140 ecs
->ptid
= target_wait (pid_ptid
, &ecs
->ws
, 0);
3143 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3145 /* If an error happens while handling the event, propagate GDB's
3146 knowledge of the executing state to the frontend/user running
3148 old_chain_2
= make_cleanup (finish_thread_state_cleanup
,
3151 /* Now figure out what to do with the result of the result. */
3152 handle_inferior_event (ecs
);
3154 /* No error, don't finish the state yet. */
3155 discard_cleanups (old_chain_2
);
3157 /* Breakpoints and watchpoints are not installed on the target
3158 at this point, and signals are passed directly to the
3159 inferior, so this must mean the process is gone. */
3160 if (!ecs
->wait_some_more
)
3162 discard_cleanups (old_chain_1
);
3163 error (_("Program exited while detaching"));
3167 discard_cleanups (old_chain_1
);
3170 /* Wait for control to return from inferior to debugger.
3172 If inferior gets a signal, we may decide to start it up again
3173 instead of returning. That is why there is a loop in this function.
3174 When this function actually returns it means the inferior
3175 should be left stopped and GDB should read more commands. */
3178 wait_for_inferior (void)
3180 struct cleanup
*old_cleanups
;
3181 struct cleanup
*thread_state_chain
;
3185 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3188 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
,
3191 /* If an error happens while handling the event, propagate GDB's
3192 knowledge of the executing state to the frontend/user running
3194 thread_state_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
3198 struct execution_control_state ecss
;
3199 struct execution_control_state
*ecs
= &ecss
;
3200 ptid_t waiton_ptid
= minus_one_ptid
;
3202 memset (ecs
, 0, sizeof (*ecs
));
3204 overlay_cache_invalid
= 1;
3206 /* Flush target cache before starting to handle each event.
3207 Target was running and cache could be stale. This is just a
3208 heuristic. Running threads may modify target memory, but we
3209 don't get any event. */
3210 target_dcache_invalidate ();
3212 if (deprecated_target_wait_hook
)
3213 ecs
->ptid
= deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, 0);
3215 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, 0);
3218 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3220 /* Now figure out what to do with the result of the result. */
3221 handle_inferior_event (ecs
);
3223 if (!ecs
->wait_some_more
)
3227 /* No error, don't finish the state yet. */
3228 discard_cleanups (thread_state_chain
);
3230 do_cleanups (old_cleanups
);
3233 /* Cleanup that reinstalls the readline callback handler, if the
3234 target is running in the background. If while handling the target
3235 event something triggered a secondary prompt, like e.g., a
3236 pagination prompt, we'll have removed the callback handler (see
3237 gdb_readline_wrapper_line). Need to do this as we go back to the
3238 event loop, ready to process further input. Note this has no
3239 effect if the handler hasn't actually been removed, because calling
3240 rl_callback_handler_install resets the line buffer, thus losing
3244 reinstall_readline_callback_handler_cleanup (void *arg
)
3246 if (!interpreter_async
)
3248 /* We're not going back to the top level event loop yet. Don't
3249 install the readline callback, as it'd prep the terminal,
3250 readline-style (raw, noecho) (e.g., --batch). We'll install
3251 it the next time the prompt is displayed, when we're ready
3256 if (async_command_editing_p
&& !sync_execution
)
3257 gdb_rl_callback_handler_reinstall ();
3260 /* Asynchronous version of wait_for_inferior. It is called by the
3261 event loop whenever a change of state is detected on the file
3262 descriptor corresponding to the target. It can be called more than
3263 once to complete a single execution command. In such cases we need
3264 to keep the state in a global variable ECSS. If it is the last time
3265 that this function is called for a single execution command, then
3266 report to the user that the inferior has stopped, and do the
3267 necessary cleanups. */
3270 fetch_inferior_event (void *client_data
)
3272 struct execution_control_state ecss
;
3273 struct execution_control_state
*ecs
= &ecss
;
3274 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
3275 struct cleanup
*ts_old_chain
;
3276 int was_sync
= sync_execution
;
3278 ptid_t waiton_ptid
= minus_one_ptid
;
3280 memset (ecs
, 0, sizeof (*ecs
));
3282 /* End up with readline processing input, if necessary. */
3283 make_cleanup (reinstall_readline_callback_handler_cleanup
, NULL
);
3285 /* We're handling a live event, so make sure we're doing live
3286 debugging. If we're looking at traceframes while the target is
3287 running, we're going to need to get back to that mode after
3288 handling the event. */
3291 make_cleanup_restore_current_traceframe ();
3292 set_current_traceframe (-1);
3296 /* In non-stop mode, the user/frontend should not notice a thread
3297 switch due to internal events. Make sure we reverse to the
3298 user selected thread and frame after handling the event and
3299 running any breakpoint commands. */
3300 make_cleanup_restore_current_thread ();
3302 overlay_cache_invalid
= 1;
3303 /* Flush target cache before starting to handle each event. Target
3304 was running and cache could be stale. This is just a heuristic.
3305 Running threads may modify target memory, but we don't get any
3307 target_dcache_invalidate ();
3309 make_cleanup_restore_integer (&execution_direction
);
3310 execution_direction
= target_execution_direction ();
3312 if (deprecated_target_wait_hook
)
3314 deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
3316 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
3319 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3321 /* If an error happens while handling the event, propagate GDB's
3322 knowledge of the executing state to the frontend/user running
3325 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
3327 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &ecs
->ptid
);
3329 /* Get executed before make_cleanup_restore_current_thread above to apply
3330 still for the thread which has thrown the exception. */
3331 make_bpstat_clear_actions_cleanup ();
3333 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
, NULL
);
3335 /* Now figure out what to do with the result of the result. */
3336 handle_inferior_event (ecs
);
3338 if (!ecs
->wait_some_more
)
3340 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3342 delete_just_stopped_threads_infrun_breakpoints ();
3344 /* We may not find an inferior if this was a process exit. */
3345 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3348 if (target_has_execution
3349 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
3350 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
3351 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
3352 && ecs
->event_thread
->step_multi
3353 && ecs
->event_thread
->control
.stop_step
)
3354 inferior_event_handler (INF_EXEC_CONTINUE
, NULL
);
3357 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3362 /* No error, don't finish the thread states yet. */
3363 discard_cleanups (ts_old_chain
);
3365 /* Revert thread and frame. */
3366 do_cleanups (old_chain
);
3368 /* If the inferior was in sync execution mode, and now isn't,
3369 restore the prompt (a synchronous execution command has finished,
3370 and we're ready for input). */
3371 if (interpreter_async
&& was_sync
&& !sync_execution
)
3372 observer_notify_sync_execution_done ();
3376 && exec_done_display_p
3377 && (ptid_equal (inferior_ptid
, null_ptid
)
3378 || !is_running (inferior_ptid
)))
3379 printf_unfiltered (_("completed.\n"));
3382 /* Record the frame and location we're currently stepping through. */
3384 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3386 struct thread_info
*tp
= inferior_thread ();
3388 tp
->control
.step_frame_id
= get_frame_id (frame
);
3389 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3391 tp
->current_symtab
= sal
.symtab
;
3392 tp
->current_line
= sal
.line
;
3395 /* Clear context switchable stepping state. */
3398 init_thread_stepping_state (struct thread_info
*tss
)
3400 tss
->stepped_breakpoint
= 0;
3401 tss
->stepping_over_breakpoint
= 0;
3402 tss
->stepping_over_watchpoint
= 0;
3403 tss
->step_after_step_resume_breakpoint
= 0;
3406 /* Set the cached copy of the last ptid/waitstatus. */
3409 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
3411 target_last_wait_ptid
= ptid
;
3412 target_last_waitstatus
= status
;
3415 /* Return the cached copy of the last pid/waitstatus returned by
3416 target_wait()/deprecated_target_wait_hook(). The data is actually
3417 cached by handle_inferior_event(), which gets called immediately
3418 after target_wait()/deprecated_target_wait_hook(). */
3421 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
3423 *ptidp
= target_last_wait_ptid
;
3424 *status
= target_last_waitstatus
;
3428 nullify_last_target_wait_ptid (void)
3430 target_last_wait_ptid
= minus_one_ptid
;
3433 /* Switch thread contexts. */
3436 context_switch (ptid_t ptid
)
3438 if (debug_infrun
&& !ptid_equal (ptid
, inferior_ptid
))
3440 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
3441 target_pid_to_str (inferior_ptid
));
3442 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
3443 target_pid_to_str (ptid
));
3446 switch_to_thread (ptid
);
3450 adjust_pc_after_break (struct execution_control_state
*ecs
)
3452 struct regcache
*regcache
;
3453 struct gdbarch
*gdbarch
;
3454 struct address_space
*aspace
;
3455 CORE_ADDR breakpoint_pc
, decr_pc
;
3457 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3458 we aren't, just return.
3460 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3461 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3462 implemented by software breakpoints should be handled through the normal
3465 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3466 different signals (SIGILL or SIGEMT for instance), but it is less
3467 clear where the PC is pointing afterwards. It may not match
3468 gdbarch_decr_pc_after_break. I don't know any specific target that
3469 generates these signals at breakpoints (the code has been in GDB since at
3470 least 1992) so I can not guess how to handle them here.
3472 In earlier versions of GDB, a target with
3473 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3474 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3475 target with both of these set in GDB history, and it seems unlikely to be
3476 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3478 if (ecs
->ws
.kind
!= TARGET_WAITKIND_STOPPED
)
3481 if (ecs
->ws
.value
.sig
!= GDB_SIGNAL_TRAP
)
3484 /* In reverse execution, when a breakpoint is hit, the instruction
3485 under it has already been de-executed. The reported PC always
3486 points at the breakpoint address, so adjusting it further would
3487 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3490 B1 0x08000000 : INSN1
3491 B2 0x08000001 : INSN2
3493 PC -> 0x08000003 : INSN4
3495 Say you're stopped at 0x08000003 as above. Reverse continuing
3496 from that point should hit B2 as below. Reading the PC when the
3497 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3498 been de-executed already.
3500 B1 0x08000000 : INSN1
3501 B2 PC -> 0x08000001 : INSN2
3505 We can't apply the same logic as for forward execution, because
3506 we would wrongly adjust the PC to 0x08000000, since there's a
3507 breakpoint at PC - 1. We'd then report a hit on B1, although
3508 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3510 if (execution_direction
== EXEC_REVERSE
)
3513 /* If the target can tell whether the thread hit a SW breakpoint,
3514 trust it. Targets that can tell also adjust the PC
3516 if (target_supports_stopped_by_sw_breakpoint ())
3519 /* Note that relying on whether a breakpoint is planted in memory to
3520 determine this can fail. E.g,. the breakpoint could have been
3521 removed since. Or the thread could have been told to step an
3522 instruction the size of a breakpoint instruction, and only
3523 _after_ was a breakpoint inserted at its address. */
3525 /* If this target does not decrement the PC after breakpoints, then
3526 we have nothing to do. */
3527 regcache
= get_thread_regcache (ecs
->ptid
);
3528 gdbarch
= get_regcache_arch (regcache
);
3530 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3534 aspace
= get_regcache_aspace (regcache
);
3536 /* Find the location where (if we've hit a breakpoint) the
3537 breakpoint would be. */
3538 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
3540 /* If the target can't tell whether a software breakpoint triggered,
3541 fallback to figuring it out based on breakpoints we think were
3542 inserted in the target, and on whether the thread was stepped or
3545 /* Check whether there actually is a software breakpoint inserted at
3548 If in non-stop mode, a race condition is possible where we've
3549 removed a breakpoint, but stop events for that breakpoint were
3550 already queued and arrive later. To suppress those spurious
3551 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3552 and retire them after a number of stop events are reported. Note
3553 this is an heuristic and can thus get confused. The real fix is
3554 to get the "stopped by SW BP and needs adjustment" info out of
3555 the target/kernel (and thus never reach here; see above). */
3556 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
3557 || (non_stop
&& moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
3559 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, NULL
);
3561 if (record_full_is_used ())
3562 record_full_gdb_operation_disable_set ();
3564 /* When using hardware single-step, a SIGTRAP is reported for both
3565 a completed single-step and a software breakpoint. Need to
3566 differentiate between the two, as the latter needs adjusting
3567 but the former does not.
3569 The SIGTRAP can be due to a completed hardware single-step only if
3570 - we didn't insert software single-step breakpoints
3571 - this thread is currently being stepped
3573 If any of these events did not occur, we must have stopped due
3574 to hitting a software breakpoint, and have to back up to the
3577 As a special case, we could have hardware single-stepped a
3578 software breakpoint. In this case (prev_pc == breakpoint_pc),
3579 we also need to back up to the breakpoint address. */
3581 if (thread_has_single_step_breakpoints_set (ecs
->event_thread
)
3582 || !currently_stepping (ecs
->event_thread
)
3583 || (ecs
->event_thread
->stepped_breakpoint
3584 && ecs
->event_thread
->prev_pc
== breakpoint_pc
))
3585 regcache_write_pc (regcache
, breakpoint_pc
);
3587 do_cleanups (old_cleanups
);
3592 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
3594 for (frame
= get_prev_frame (frame
);
3596 frame
= get_prev_frame (frame
))
3598 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
3600 if (get_frame_type (frame
) != INLINE_FRAME
)
3607 /* Auxiliary function that handles syscall entry/return events.
3608 It returns 1 if the inferior should keep going (and GDB
3609 should ignore the event), or 0 if the event deserves to be
3613 handle_syscall_event (struct execution_control_state
*ecs
)
3615 struct regcache
*regcache
;
3618 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3619 context_switch (ecs
->ptid
);
3621 regcache
= get_thread_regcache (ecs
->ptid
);
3622 syscall_number
= ecs
->ws
.value
.syscall_number
;
3623 stop_pc
= regcache_read_pc (regcache
);
3625 if (catch_syscall_enabled () > 0
3626 && catching_syscall_number (syscall_number
) > 0)
3629 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
3632 ecs
->event_thread
->control
.stop_bpstat
3633 = bpstat_stop_status (get_regcache_aspace (regcache
),
3634 stop_pc
, ecs
->ptid
, &ecs
->ws
);
3636 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
3638 /* Catchpoint hit. */
3643 /* If no catchpoint triggered for this, then keep going. */
3648 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3651 fill_in_stop_func (struct gdbarch
*gdbarch
,
3652 struct execution_control_state
*ecs
)
3654 if (!ecs
->stop_func_filled_in
)
3656 /* Don't care about return value; stop_func_start and stop_func_name
3657 will both be 0 if it doesn't work. */
3658 find_pc_partial_function (stop_pc
, &ecs
->stop_func_name
,
3659 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
3660 ecs
->stop_func_start
3661 += gdbarch_deprecated_function_start_offset (gdbarch
);
3663 if (gdbarch_skip_entrypoint_p (gdbarch
))
3664 ecs
->stop_func_start
= gdbarch_skip_entrypoint (gdbarch
,
3665 ecs
->stop_func_start
);
3667 ecs
->stop_func_filled_in
= 1;
3672 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
3674 static enum stop_kind
3675 get_inferior_stop_soon (ptid_t ptid
)
3677 struct inferior
*inf
= find_inferior_ptid (ptid
);
3679 gdb_assert (inf
!= NULL
);
3680 return inf
->control
.stop_soon
;
3683 /* Given an execution control state that has been freshly filled in by
3684 an event from the inferior, figure out what it means and take
3687 The alternatives are:
3689 1) stop_waiting and return; to really stop and return to the
3692 2) keep_going and return; to wait for the next event (set
3693 ecs->event_thread->stepping_over_breakpoint to 1 to single step
3697 handle_inferior_event (struct execution_control_state
*ecs
)
3699 enum stop_kind stop_soon
;
3701 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
3703 /* We had an event in the inferior, but we are not interested in
3704 handling it at this level. The lower layers have already
3705 done what needs to be done, if anything.
3707 One of the possible circumstances for this is when the
3708 inferior produces output for the console. The inferior has
3709 not stopped, and we are ignoring the event. Another possible
3710 circumstance is any event which the lower level knows will be
3711 reported multiple times without an intervening resume. */
3713 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
3714 prepare_to_wait (ecs
);
3718 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
3719 && target_can_async_p () && !sync_execution
)
3721 /* There were no unwaited-for children left in the target, but,
3722 we're not synchronously waiting for events either. Just
3723 ignore. Otherwise, if we were running a synchronous
3724 execution command, we need to cancel it and give the user
3725 back the terminal. */
3727 fprintf_unfiltered (gdb_stdlog
,
3728 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3729 prepare_to_wait (ecs
);
3733 /* Cache the last pid/waitstatus. */
3734 set_last_target_status (ecs
->ptid
, ecs
->ws
);
3736 /* Always clear state belonging to the previous time we stopped. */
3737 stop_stack_dummy
= STOP_NONE
;
3739 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
3741 /* No unwaited-for children left. IOW, all resumed children
3744 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3746 stop_print_frame
= 0;
3751 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
3752 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
3754 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
3755 /* If it's a new thread, add it to the thread database. */
3756 if (ecs
->event_thread
== NULL
)
3757 ecs
->event_thread
= add_thread (ecs
->ptid
);
3759 /* Disable range stepping. If the next step request could use a
3760 range, this will be end up re-enabled then. */
3761 ecs
->event_thread
->control
.may_range_step
= 0;
3764 /* Dependent on valid ECS->EVENT_THREAD. */
3765 adjust_pc_after_break (ecs
);
3767 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3768 reinit_frame_cache ();
3770 breakpoint_retire_moribund ();
3772 /* First, distinguish signals caused by the debugger from signals
3773 that have to do with the program's own actions. Note that
3774 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3775 on the operating system version. Here we detect when a SIGILL or
3776 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3777 something similar for SIGSEGV, since a SIGSEGV will be generated
3778 when we're trying to execute a breakpoint instruction on a
3779 non-executable stack. This happens for call dummy breakpoints
3780 for architectures like SPARC that place call dummies on the
3782 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
3783 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
3784 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
3785 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
3787 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3789 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
3790 regcache_read_pc (regcache
)))
3793 fprintf_unfiltered (gdb_stdlog
,
3794 "infrun: Treating signal as SIGTRAP\n");
3795 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
3799 /* Mark the non-executing threads accordingly. In all-stop, all
3800 threads of all processes are stopped when we get any event
3801 reported. In non-stop mode, only the event thread stops. If
3802 we're handling a process exit in non-stop mode, there's nothing
3803 to do, as threads of the dead process are gone, and threads of
3804 any other process were left running. */
3806 set_executing (minus_one_ptid
, 0);
3807 else if (ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
3808 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
)
3809 set_executing (ecs
->ptid
, 0);
3811 switch (ecs
->ws
.kind
)
3813 case TARGET_WAITKIND_LOADED
:
3815 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
3816 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3817 context_switch (ecs
->ptid
);
3818 /* Ignore gracefully during startup of the inferior, as it might
3819 be the shell which has just loaded some objects, otherwise
3820 add the symbols for the newly loaded objects. Also ignore at
3821 the beginning of an attach or remote session; we will query
3822 the full list of libraries once the connection is
3825 stop_soon
= get_inferior_stop_soon (ecs
->ptid
);
3826 if (stop_soon
== NO_STOP_QUIETLY
)
3828 struct regcache
*regcache
;
3830 regcache
= get_thread_regcache (ecs
->ptid
);
3832 handle_solib_event ();
3834 ecs
->event_thread
->control
.stop_bpstat
3835 = bpstat_stop_status (get_regcache_aspace (regcache
),
3836 stop_pc
, ecs
->ptid
, &ecs
->ws
);
3838 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
3840 /* A catchpoint triggered. */
3841 process_event_stop_test (ecs
);
3845 /* If requested, stop when the dynamic linker notifies
3846 gdb of events. This allows the user to get control
3847 and place breakpoints in initializer routines for
3848 dynamically loaded objects (among other things). */
3849 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
3850 if (stop_on_solib_events
)
3852 /* Make sure we print "Stopped due to solib-event" in
3854 stop_print_frame
= 1;
3861 /* If we are skipping through a shell, or through shared library
3862 loading that we aren't interested in, resume the program. If
3863 we're running the program normally, also resume. */
3864 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
3866 /* Loading of shared libraries might have changed breakpoint
3867 addresses. Make sure new breakpoints are inserted. */
3868 if (stop_soon
== NO_STOP_QUIETLY
)
3869 insert_breakpoints ();
3870 resume (GDB_SIGNAL_0
);
3871 prepare_to_wait (ecs
);
3875 /* But stop if we're attaching or setting up a remote
3877 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
3878 || stop_soon
== STOP_QUIETLY_REMOTE
)
3881 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
3886 internal_error (__FILE__
, __LINE__
,
3887 _("unhandled stop_soon: %d"), (int) stop_soon
);
3889 case TARGET_WAITKIND_SPURIOUS
:
3891 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3892 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3893 context_switch (ecs
->ptid
);
3894 resume (GDB_SIGNAL_0
);
3895 prepare_to_wait (ecs
);
3898 case TARGET_WAITKIND_EXITED
:
3899 case TARGET_WAITKIND_SIGNALLED
:
3902 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
3903 fprintf_unfiltered (gdb_stdlog
,
3904 "infrun: TARGET_WAITKIND_EXITED\n");
3906 fprintf_unfiltered (gdb_stdlog
,
3907 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3910 inferior_ptid
= ecs
->ptid
;
3911 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
3912 set_current_program_space (current_inferior ()->pspace
);
3913 handle_vfork_child_exec_or_exit (0);
3914 target_terminal_ours (); /* Must do this before mourn anyway. */
3916 /* Clearing any previous state of convenience variables. */
3917 clear_exit_convenience_vars ();
3919 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
3921 /* Record the exit code in the convenience variable $_exitcode, so
3922 that the user can inspect this again later. */
3923 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3924 (LONGEST
) ecs
->ws
.value
.integer
);
3926 /* Also record this in the inferior itself. */
3927 current_inferior ()->has_exit_code
= 1;
3928 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
3930 /* Support the --return-child-result option. */
3931 return_child_result_value
= ecs
->ws
.value
.integer
;
3933 observer_notify_exited (ecs
->ws
.value
.integer
);
3937 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3938 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3940 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
3942 /* Set the value of the internal variable $_exitsignal,
3943 which holds the signal uncaught by the inferior. */
3944 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
3945 gdbarch_gdb_signal_to_target (gdbarch
,
3946 ecs
->ws
.value
.sig
));
3950 /* We don't have access to the target's method used for
3951 converting between signal numbers (GDB's internal
3952 representation <-> target's representation).
3953 Therefore, we cannot do a good job at displaying this
3954 information to the user. It's better to just warn
3955 her about it (if infrun debugging is enabled), and
3958 fprintf_filtered (gdb_stdlog
, _("\
3959 Cannot fill $_exitsignal with the correct signal number.\n"));
3962 observer_notify_signal_exited (ecs
->ws
.value
.sig
);
3965 gdb_flush (gdb_stdout
);
3966 target_mourn_inferior ();
3967 stop_print_frame
= 0;
3971 /* The following are the only cases in which we keep going;
3972 the above cases end in a continue or goto. */
3973 case TARGET_WAITKIND_FORKED
:
3974 case TARGET_WAITKIND_VFORKED
:
3977 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
3978 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
3980 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_VFORKED\n");
3983 /* Check whether the inferior is displaced stepping. */
3985 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3986 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3987 struct displaced_step_inferior_state
*displaced
3988 = get_displaced_stepping_state (ptid_get_pid (ecs
->ptid
));
3990 /* If checking displaced stepping is supported, and thread
3991 ecs->ptid is displaced stepping. */
3992 if (displaced
&& ptid_equal (displaced
->step_ptid
, ecs
->ptid
))
3994 struct inferior
*parent_inf
3995 = find_inferior_ptid (ecs
->ptid
);
3996 struct regcache
*child_regcache
;
3997 CORE_ADDR parent_pc
;
3999 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4000 indicating that the displaced stepping of syscall instruction
4001 has been done. Perform cleanup for parent process here. Note
4002 that this operation also cleans up the child process for vfork,
4003 because their pages are shared. */
4004 displaced_step_fixup (ecs
->ptid
, GDB_SIGNAL_TRAP
);
4006 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
4008 /* Restore scratch pad for child process. */
4009 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
4012 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4013 the child's PC is also within the scratchpad. Set the child's PC
4014 to the parent's PC value, which has already been fixed up.
4015 FIXME: we use the parent's aspace here, although we're touching
4016 the child, because the child hasn't been added to the inferior
4017 list yet at this point. */
4020 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
4022 parent_inf
->aspace
);
4023 /* Read PC value of parent process. */
4024 parent_pc
= regcache_read_pc (regcache
);
4026 if (debug_displaced
)
4027 fprintf_unfiltered (gdb_stdlog
,
4028 "displaced: write child pc from %s to %s\n",
4030 regcache_read_pc (child_regcache
)),
4031 paddress (gdbarch
, parent_pc
));
4033 regcache_write_pc (child_regcache
, parent_pc
);
4037 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4038 context_switch (ecs
->ptid
);
4040 /* Immediately detach breakpoints from the child before there's
4041 any chance of letting the user delete breakpoints from the
4042 breakpoint lists. If we don't do this early, it's easy to
4043 leave left over traps in the child, vis: "break foo; catch
4044 fork; c; <fork>; del; c; <child calls foo>". We only follow
4045 the fork on the last `continue', and by that time the
4046 breakpoint at "foo" is long gone from the breakpoint table.
4047 If we vforked, then we don't need to unpatch here, since both
4048 parent and child are sharing the same memory pages; we'll
4049 need to unpatch at follow/detach time instead to be certain
4050 that new breakpoints added between catchpoint hit time and
4051 vfork follow are detached. */
4052 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
4054 /* This won't actually modify the breakpoint list, but will
4055 physically remove the breakpoints from the child. */
4056 detach_breakpoints (ecs
->ws
.value
.related_pid
);
4059 delete_just_stopped_threads_single_step_breakpoints ();
4061 /* In case the event is caught by a catchpoint, remember that
4062 the event is to be followed at the next resume of the thread,
4063 and not immediately. */
4064 ecs
->event_thread
->pending_follow
= ecs
->ws
;
4066 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4068 ecs
->event_thread
->control
.stop_bpstat
4069 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4070 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4072 /* If no catchpoint triggered for this, then keep going. Note
4073 that we're interested in knowing the bpstat actually causes a
4074 stop, not just if it may explain the signal. Software
4075 watchpoints, for example, always appear in the bpstat. */
4076 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4082 = (follow_fork_mode_string
== follow_fork_mode_child
);
4084 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4086 should_resume
= follow_fork ();
4089 child
= ecs
->ws
.value
.related_pid
;
4091 /* In non-stop mode, also resume the other branch. */
4092 if (non_stop
&& !detach_fork
)
4095 switch_to_thread (parent
);
4097 switch_to_thread (child
);
4099 ecs
->event_thread
= inferior_thread ();
4100 ecs
->ptid
= inferior_ptid
;
4105 switch_to_thread (child
);
4107 switch_to_thread (parent
);
4109 ecs
->event_thread
= inferior_thread ();
4110 ecs
->ptid
= inferior_ptid
;
4118 process_event_stop_test (ecs
);
4121 case TARGET_WAITKIND_VFORK_DONE
:
4122 /* Done with the shared memory region. Re-insert breakpoints in
4123 the parent, and keep going. */
4126 fprintf_unfiltered (gdb_stdlog
,
4127 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
4129 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4130 context_switch (ecs
->ptid
);
4132 current_inferior ()->waiting_for_vfork_done
= 0;
4133 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
4134 /* This also takes care of reinserting breakpoints in the
4135 previously locked inferior. */
4139 case TARGET_WAITKIND_EXECD
:
4141 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
4143 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4144 context_switch (ecs
->ptid
);
4146 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4148 /* Do whatever is necessary to the parent branch of the vfork. */
4149 handle_vfork_child_exec_or_exit (1);
4151 /* This causes the eventpoints and symbol table to be reset.
4152 Must do this now, before trying to determine whether to
4154 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
4156 ecs
->event_thread
->control
.stop_bpstat
4157 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4158 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4160 /* Note that this may be referenced from inside
4161 bpstat_stop_status above, through inferior_has_execd. */
4162 xfree (ecs
->ws
.value
.execd_pathname
);
4163 ecs
->ws
.value
.execd_pathname
= NULL
;
4165 /* If no catchpoint triggered for this, then keep going. */
4166 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4168 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4172 process_event_stop_test (ecs
);
4175 /* Be careful not to try to gather much state about a thread
4176 that's in a syscall. It's frequently a losing proposition. */
4177 case TARGET_WAITKIND_SYSCALL_ENTRY
:
4179 fprintf_unfiltered (gdb_stdlog
,
4180 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
4181 /* Getting the current syscall number. */
4182 if (handle_syscall_event (ecs
) == 0)
4183 process_event_stop_test (ecs
);
4186 /* Before examining the threads further, step this thread to
4187 get it entirely out of the syscall. (We get notice of the
4188 event when the thread is just on the verge of exiting a
4189 syscall. Stepping one instruction seems to get it back
4191 case TARGET_WAITKIND_SYSCALL_RETURN
:
4193 fprintf_unfiltered (gdb_stdlog
,
4194 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
4195 if (handle_syscall_event (ecs
) == 0)
4196 process_event_stop_test (ecs
);
4199 case TARGET_WAITKIND_STOPPED
:
4201 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
4202 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
4203 handle_signal_stop (ecs
);
4206 case TARGET_WAITKIND_NO_HISTORY
:
4208 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
4209 /* Reverse execution: target ran out of history info. */
4211 delete_just_stopped_threads_single_step_breakpoints ();
4212 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4213 observer_notify_no_history ();
4219 /* Come here when the program has stopped with a signal. */
4222 handle_signal_stop (struct execution_control_state
*ecs
)
4224 struct frame_info
*frame
;
4225 struct gdbarch
*gdbarch
;
4226 int stopped_by_watchpoint
;
4227 enum stop_kind stop_soon
;
4230 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
4232 /* Do we need to clean up the state of a thread that has
4233 completed a displaced single-step? (Doing so usually affects
4234 the PC, so do it here, before we set stop_pc.) */
4235 displaced_step_fixup (ecs
->ptid
,
4236 ecs
->event_thread
->suspend
.stop_signal
);
4238 /* If we either finished a single-step or hit a breakpoint, but
4239 the user wanted this thread to be stopped, pretend we got a
4240 SIG0 (generic unsignaled stop). */
4241 if (ecs
->event_thread
->stop_requested
4242 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
4243 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4245 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4249 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
4250 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
4251 struct cleanup
*old_chain
= save_inferior_ptid ();
4253 inferior_ptid
= ecs
->ptid
;
4255 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
4256 paddress (gdbarch
, stop_pc
));
4257 if (target_stopped_by_watchpoint ())
4261 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
4263 if (target_stopped_data_address (¤t_target
, &addr
))
4264 fprintf_unfiltered (gdb_stdlog
,
4265 "infrun: stopped data address = %s\n",
4266 paddress (gdbarch
, addr
));
4268 fprintf_unfiltered (gdb_stdlog
,
4269 "infrun: (no data address available)\n");
4272 do_cleanups (old_chain
);
4275 /* This is originated from start_remote(), start_inferior() and
4276 shared libraries hook functions. */
4277 stop_soon
= get_inferior_stop_soon (ecs
->ptid
);
4278 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
4280 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4281 context_switch (ecs
->ptid
);
4283 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4284 stop_print_frame
= 1;
4289 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4292 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4293 context_switch (ecs
->ptid
);
4295 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
4296 stop_print_frame
= 0;
4301 /* This originates from attach_command(). We need to overwrite
4302 the stop_signal here, because some kernels don't ignore a
4303 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4304 See more comments in inferior.h. On the other hand, if we
4305 get a non-SIGSTOP, report it to the user - assume the backend
4306 will handle the SIGSTOP if it should show up later.
4308 Also consider that the attach is complete when we see a
4309 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4310 target extended-remote report it instead of a SIGSTOP
4311 (e.g. gdbserver). We already rely on SIGTRAP being our
4312 signal, so this is no exception.
4314 Also consider that the attach is complete when we see a
4315 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4316 the target to stop all threads of the inferior, in case the
4317 low level attach operation doesn't stop them implicitly. If
4318 they weren't stopped implicitly, then the stub will report a
4319 GDB_SIGNAL_0, meaning: stopped for no particular reason
4320 other than GDB's request. */
4321 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4322 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
4323 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4324 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
4326 stop_print_frame
= 1;
4328 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4332 /* See if something interesting happened to the non-current thread. If
4333 so, then switch to that thread. */
4334 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4337 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
4339 context_switch (ecs
->ptid
);
4341 if (deprecated_context_hook
)
4342 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
4345 /* At this point, get hold of the now-current thread's frame. */
4346 frame
= get_current_frame ();
4347 gdbarch
= get_frame_arch (frame
);
4349 /* Pull the single step breakpoints out of the target. */
4350 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
4352 struct regcache
*regcache
;
4353 struct address_space
*aspace
;
4356 regcache
= get_thread_regcache (ecs
->ptid
);
4357 aspace
= get_regcache_aspace (regcache
);
4358 pc
= regcache_read_pc (regcache
);
4360 /* However, before doing so, if this single-step breakpoint was
4361 actually for another thread, set this thread up for moving
4363 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
4366 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
4370 fprintf_unfiltered (gdb_stdlog
,
4371 "infrun: [%s] hit another thread's "
4372 "single-step breakpoint\n",
4373 target_pid_to_str (ecs
->ptid
));
4375 ecs
->hit_singlestep_breakpoint
= 1;
4382 fprintf_unfiltered (gdb_stdlog
,
4383 "infrun: [%s] hit its "
4384 "single-step breakpoint\n",
4385 target_pid_to_str (ecs
->ptid
));
4389 delete_just_stopped_threads_single_step_breakpoints ();
4391 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4392 && ecs
->event_thread
->control
.trap_expected
4393 && ecs
->event_thread
->stepping_over_watchpoint
)
4394 stopped_by_watchpoint
= 0;
4396 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
4398 /* If necessary, step over this watchpoint. We'll be back to display
4400 if (stopped_by_watchpoint
4401 && (target_have_steppable_watchpoint
4402 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
4404 /* At this point, we are stopped at an instruction which has
4405 attempted to write to a piece of memory under control of
4406 a watchpoint. The instruction hasn't actually executed
4407 yet. If we were to evaluate the watchpoint expression
4408 now, we would get the old value, and therefore no change
4409 would seem to have occurred.
4411 In order to make watchpoints work `right', we really need
4412 to complete the memory write, and then evaluate the
4413 watchpoint expression. We do this by single-stepping the
4416 It may not be necessary to disable the watchpoint to step over
4417 it. For example, the PA can (with some kernel cooperation)
4418 single step over a watchpoint without disabling the watchpoint.
4420 It is far more common to need to disable a watchpoint to step
4421 the inferior over it. If we have non-steppable watchpoints,
4422 we must disable the current watchpoint; it's simplest to
4423 disable all watchpoints.
4425 Any breakpoint at PC must also be stepped over -- if there's
4426 one, it will have already triggered before the watchpoint
4427 triggered, and we either already reported it to the user, or
4428 it didn't cause a stop and we called keep_going. In either
4429 case, if there was a breakpoint at PC, we must be trying to
4431 ecs
->event_thread
->stepping_over_watchpoint
= 1;
4436 ecs
->event_thread
->stepping_over_breakpoint
= 0;
4437 ecs
->event_thread
->stepping_over_watchpoint
= 0;
4438 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
4439 ecs
->event_thread
->control
.stop_step
= 0;
4440 stop_print_frame
= 1;
4441 stopped_by_random_signal
= 0;
4443 /* Hide inlined functions starting here, unless we just performed stepi or
4444 nexti. After stepi and nexti, always show the innermost frame (not any
4445 inline function call sites). */
4446 if (ecs
->event_thread
->control
.step_range_end
!= 1)
4448 struct address_space
*aspace
=
4449 get_regcache_aspace (get_thread_regcache (ecs
->ptid
));
4451 /* skip_inline_frames is expensive, so we avoid it if we can
4452 determine that the address is one where functions cannot have
4453 been inlined. This improves performance with inferiors that
4454 load a lot of shared libraries, because the solib event
4455 breakpoint is defined as the address of a function (i.e. not
4456 inline). Note that we have to check the previous PC as well
4457 as the current one to catch cases when we have just
4458 single-stepped off a breakpoint prior to reinstating it.
4459 Note that we're assuming that the code we single-step to is
4460 not inline, but that's not definitive: there's nothing
4461 preventing the event breakpoint function from containing
4462 inlined code, and the single-step ending up there. If the
4463 user had set a breakpoint on that inlined code, the missing
4464 skip_inline_frames call would break things. Fortunately
4465 that's an extremely unlikely scenario. */
4466 if (!pc_at_non_inline_function (aspace
, stop_pc
, &ecs
->ws
)
4467 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4468 && ecs
->event_thread
->control
.trap_expected
4469 && pc_at_non_inline_function (aspace
,
4470 ecs
->event_thread
->prev_pc
,
4473 skip_inline_frames (ecs
->ptid
);
4475 /* Re-fetch current thread's frame in case that invalidated
4477 frame
= get_current_frame ();
4478 gdbarch
= get_frame_arch (frame
);
4482 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4483 && ecs
->event_thread
->control
.trap_expected
4484 && gdbarch_single_step_through_delay_p (gdbarch
)
4485 && currently_stepping (ecs
->event_thread
))
4487 /* We're trying to step off a breakpoint. Turns out that we're
4488 also on an instruction that needs to be stepped multiple
4489 times before it's been fully executing. E.g., architectures
4490 with a delay slot. It needs to be stepped twice, once for
4491 the instruction and once for the delay slot. */
4492 int step_through_delay
4493 = gdbarch_single_step_through_delay (gdbarch
, frame
);
4495 if (debug_infrun
&& step_through_delay
)
4496 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
4497 if (ecs
->event_thread
->control
.step_range_end
== 0
4498 && step_through_delay
)
4500 /* The user issued a continue when stopped at a breakpoint.
4501 Set up for another trap and get out of here. */
4502 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4506 else if (step_through_delay
)
4508 /* The user issued a step when stopped at a breakpoint.
4509 Maybe we should stop, maybe we should not - the delay
4510 slot *might* correspond to a line of source. In any
4511 case, don't decide that here, just set
4512 ecs->stepping_over_breakpoint, making sure we
4513 single-step again before breakpoints are re-inserted. */
4514 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4518 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4519 handles this event. */
4520 ecs
->event_thread
->control
.stop_bpstat
4521 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4522 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4524 /* Following in case break condition called a
4526 stop_print_frame
= 1;
4528 /* This is where we handle "moribund" watchpoints. Unlike
4529 software breakpoints traps, hardware watchpoint traps are
4530 always distinguishable from random traps. If no high-level
4531 watchpoint is associated with the reported stop data address
4532 anymore, then the bpstat does not explain the signal ---
4533 simply make sure to ignore it if `stopped_by_watchpoint' is
4537 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4538 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
4540 && stopped_by_watchpoint
)
4541 fprintf_unfiltered (gdb_stdlog
,
4542 "infrun: no user watchpoint explains "
4543 "watchpoint SIGTRAP, ignoring\n");
4545 /* NOTE: cagney/2003-03-29: These checks for a random signal
4546 at one stage in the past included checks for an inferior
4547 function call's call dummy's return breakpoint. The original
4548 comment, that went with the test, read:
4550 ``End of a stack dummy. Some systems (e.g. Sony news) give
4551 another signal besides SIGTRAP, so check here as well as
4554 If someone ever tries to get call dummys on a
4555 non-executable stack to work (where the target would stop
4556 with something like a SIGSEGV), then those tests might need
4557 to be re-instated. Given, however, that the tests were only
4558 enabled when momentary breakpoints were not being used, I
4559 suspect that it won't be the case.
4561 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4562 be necessary for call dummies on a non-executable stack on
4565 /* See if the breakpoints module can explain the signal. */
4567 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
4568 ecs
->event_thread
->suspend
.stop_signal
);
4570 /* Maybe this was a trap for a software breakpoint that has since
4572 if (random_signal
&& target_stopped_by_sw_breakpoint ())
4574 if (program_breakpoint_here_p (gdbarch
, stop_pc
))
4576 struct regcache
*regcache
;
4579 /* Re-adjust PC to what the program would see if GDB was not
4581 regcache
= get_thread_regcache (ecs
->event_thread
->ptid
);
4582 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4585 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, NULL
);
4587 if (record_full_is_used ())
4588 record_full_gdb_operation_disable_set ();
4590 regcache_write_pc (regcache
, stop_pc
+ decr_pc
);
4592 do_cleanups (old_cleanups
);
4597 /* A delayed software breakpoint event. Ignore the trap. */
4599 fprintf_unfiltered (gdb_stdlog
,
4600 "infrun: delayed software breakpoint "
4601 "trap, ignoring\n");
4606 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
4607 has since been removed. */
4608 if (random_signal
&& target_stopped_by_hw_breakpoint ())
4610 /* A delayed hardware breakpoint event. Ignore the trap. */
4612 fprintf_unfiltered (gdb_stdlog
,
4613 "infrun: delayed hardware breakpoint/watchpoint "
4614 "trap, ignoring\n");
4618 /* If not, perhaps stepping/nexting can. */
4620 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
4621 && currently_stepping (ecs
->event_thread
));
4623 /* Perhaps the thread hit a single-step breakpoint of _another_
4624 thread. Single-step breakpoints are transparent to the
4625 breakpoints module. */
4627 random_signal
= !ecs
->hit_singlestep_breakpoint
;
4629 /* No? Perhaps we got a moribund watchpoint. */
4631 random_signal
= !stopped_by_watchpoint
;
4633 /* For the program's own signals, act according to
4634 the signal handling tables. */
4638 /* Signal not for debugging purposes. */
4639 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
4640 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
4643 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
4644 gdb_signal_to_symbol_string (stop_signal
));
4646 stopped_by_random_signal
= 1;
4648 /* Always stop on signals if we're either just gaining control
4649 of the program, or the user explicitly requested this thread
4650 to remain stopped. */
4651 if (stop_soon
!= NO_STOP_QUIETLY
4652 || ecs
->event_thread
->stop_requested
4654 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
4660 /* Notify observers the signal has "handle print" set. Note we
4661 returned early above if stopping; normal_stop handles the
4662 printing in that case. */
4663 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
4665 /* The signal table tells us to print about this signal. */
4666 target_terminal_ours_for_output ();
4667 observer_notify_signal_received (ecs
->event_thread
->suspend
.stop_signal
);
4668 target_terminal_inferior ();
4671 /* Clear the signal if it should not be passed. */
4672 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
4673 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4675 if (ecs
->event_thread
->prev_pc
== stop_pc
4676 && ecs
->event_thread
->control
.trap_expected
4677 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
4679 /* We were just starting a new sequence, attempting to
4680 single-step off of a breakpoint and expecting a SIGTRAP.
4681 Instead this signal arrives. This signal will take us out
4682 of the stepping range so GDB needs to remember to, when
4683 the signal handler returns, resume stepping off that
4685 /* To simplify things, "continue" is forced to use the same
4686 code paths as single-step - set a breakpoint at the
4687 signal return address and then, once hit, step off that
4690 fprintf_unfiltered (gdb_stdlog
,
4691 "infrun: signal arrived while stepping over "
4694 insert_hp_step_resume_breakpoint_at_frame (frame
);
4695 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
4696 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4697 ecs
->event_thread
->control
.trap_expected
= 0;
4699 /* If we were nexting/stepping some other thread, switch to
4700 it, so that we don't continue it, losing control. */
4701 if (!switch_back_to_stepped_thread (ecs
))
4706 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
4707 && (pc_in_thread_step_range (stop_pc
, ecs
->event_thread
)
4708 || ecs
->event_thread
->control
.step_range_end
== 1)
4709 && frame_id_eq (get_stack_frame_id (frame
),
4710 ecs
->event_thread
->control
.step_stack_frame_id
)
4711 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
4713 /* The inferior is about to take a signal that will take it
4714 out of the single step range. Set a breakpoint at the
4715 current PC (which is presumably where the signal handler
4716 will eventually return) and then allow the inferior to
4719 Note that this is only needed for a signal delivered
4720 while in the single-step range. Nested signals aren't a
4721 problem as they eventually all return. */
4723 fprintf_unfiltered (gdb_stdlog
,
4724 "infrun: signal may take us out of "
4725 "single-step range\n");
4727 insert_hp_step_resume_breakpoint_at_frame (frame
);
4728 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
4729 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4730 ecs
->event_thread
->control
.trap_expected
= 0;
4735 /* Note: step_resume_breakpoint may be non-NULL. This occures
4736 when either there's a nested signal, or when there's a
4737 pending signal enabled just as the signal handler returns
4738 (leaving the inferior at the step-resume-breakpoint without
4739 actually executing it). Either way continue until the
4740 breakpoint is really hit. */
4742 if (!switch_back_to_stepped_thread (ecs
))
4745 fprintf_unfiltered (gdb_stdlog
,
4746 "infrun: random signal, keep going\n");
4753 process_event_stop_test (ecs
);
4756 /* Come here when we've got some debug event / signal we can explain
4757 (IOW, not a random signal), and test whether it should cause a
4758 stop, or whether we should resume the inferior (transparently).
4759 E.g., could be a breakpoint whose condition evaluates false; we
4760 could be still stepping within the line; etc. */
4763 process_event_stop_test (struct execution_control_state
*ecs
)
4765 struct symtab_and_line stop_pc_sal
;
4766 struct frame_info
*frame
;
4767 struct gdbarch
*gdbarch
;
4768 CORE_ADDR jmp_buf_pc
;
4769 struct bpstat_what what
;
4771 /* Handle cases caused by hitting a breakpoint. */
4773 frame
= get_current_frame ();
4774 gdbarch
= get_frame_arch (frame
);
4776 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
4778 if (what
.call_dummy
)
4780 stop_stack_dummy
= what
.call_dummy
;
4783 /* If we hit an internal event that triggers symbol changes, the
4784 current frame will be invalidated within bpstat_what (e.g., if we
4785 hit an internal solib event). Re-fetch it. */
4786 frame
= get_current_frame ();
4787 gdbarch
= get_frame_arch (frame
);
4789 switch (what
.main_action
)
4791 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
4792 /* If we hit the breakpoint at longjmp while stepping, we
4793 install a momentary breakpoint at the target of the
4797 fprintf_unfiltered (gdb_stdlog
,
4798 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4800 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4802 if (what
.is_longjmp
)
4804 struct value
*arg_value
;
4806 /* If we set the longjmp breakpoint via a SystemTap probe,
4807 then use it to extract the arguments. The destination PC
4808 is the third argument to the probe. */
4809 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
4812 jmp_buf_pc
= value_as_address (arg_value
);
4813 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
4815 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
4816 || !gdbarch_get_longjmp_target (gdbarch
,
4817 frame
, &jmp_buf_pc
))
4820 fprintf_unfiltered (gdb_stdlog
,
4821 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4822 "(!gdbarch_get_longjmp_target)\n");
4827 /* Insert a breakpoint at resume address. */
4828 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
4831 check_exception_resume (ecs
, frame
);
4835 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
4837 struct frame_info
*init_frame
;
4839 /* There are several cases to consider.
4841 1. The initiating frame no longer exists. In this case we
4842 must stop, because the exception or longjmp has gone too
4845 2. The initiating frame exists, and is the same as the
4846 current frame. We stop, because the exception or longjmp
4849 3. The initiating frame exists and is different from the
4850 current frame. This means the exception or longjmp has
4851 been caught beneath the initiating frame, so keep going.
4853 4. longjmp breakpoint has been placed just to protect
4854 against stale dummy frames and user is not interested in
4855 stopping around longjmps. */
4858 fprintf_unfiltered (gdb_stdlog
,
4859 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4861 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
4863 delete_exception_resume_breakpoint (ecs
->event_thread
);
4865 if (what
.is_longjmp
)
4867 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
4869 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
4877 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
4881 struct frame_id current_id
4882 = get_frame_id (get_current_frame ());
4883 if (frame_id_eq (current_id
,
4884 ecs
->event_thread
->initiating_frame
))
4886 /* Case 2. Fall through. */
4896 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
4898 delete_step_resume_breakpoint (ecs
->event_thread
);
4900 end_stepping_range (ecs
);
4904 case BPSTAT_WHAT_SINGLE
:
4906 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
4907 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4908 /* Still need to check other stuff, at least the case where we
4909 are stepping and step out of the right range. */
4912 case BPSTAT_WHAT_STEP_RESUME
:
4914 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4916 delete_step_resume_breakpoint (ecs
->event_thread
);
4917 if (ecs
->event_thread
->control
.proceed_to_finish
4918 && execution_direction
== EXEC_REVERSE
)
4920 struct thread_info
*tp
= ecs
->event_thread
;
4922 /* We are finishing a function in reverse, and just hit the
4923 step-resume breakpoint at the start address of the
4924 function, and we're almost there -- just need to back up
4925 by one more single-step, which should take us back to the
4927 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
4931 fill_in_stop_func (gdbarch
, ecs
);
4932 if (stop_pc
== ecs
->stop_func_start
4933 && execution_direction
== EXEC_REVERSE
)
4935 /* We are stepping over a function call in reverse, and just
4936 hit the step-resume breakpoint at the start address of
4937 the function. Go back to single-stepping, which should
4938 take us back to the function call. */
4939 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4945 case BPSTAT_WHAT_STOP_NOISY
:
4947 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4948 stop_print_frame
= 1;
4950 /* Assume the thread stopped for a breapoint. We'll still check
4951 whether a/the breakpoint is there when the thread is next
4953 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4958 case BPSTAT_WHAT_STOP_SILENT
:
4960 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4961 stop_print_frame
= 0;
4963 /* Assume the thread stopped for a breapoint. We'll still check
4964 whether a/the breakpoint is there when the thread is next
4966 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4970 case BPSTAT_WHAT_HP_STEP_RESUME
:
4972 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4974 delete_step_resume_breakpoint (ecs
->event_thread
);
4975 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
4977 /* Back when the step-resume breakpoint was inserted, we
4978 were trying to single-step off a breakpoint. Go back to
4980 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
4981 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4987 case BPSTAT_WHAT_KEEP_CHECKING
:
4991 /* If we stepped a permanent breakpoint and we had a high priority
4992 step-resume breakpoint for the address we stepped, but we didn't
4993 hit it, then we must have stepped into the signal handler. The
4994 step-resume was only necessary to catch the case of _not_
4995 stepping into the handler, so delete it, and fall through to
4996 checking whether the step finished. */
4997 if (ecs
->event_thread
->stepped_breakpoint
)
4999 struct breakpoint
*sr_bp
5000 = ecs
->event_thread
->control
.step_resume_breakpoint
;
5003 && sr_bp
->loc
->permanent
5004 && sr_bp
->type
== bp_hp_step_resume
5005 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
5008 fprintf_unfiltered (gdb_stdlog
,
5009 "infrun: stepped permanent breakpoint, stopped in "
5011 delete_step_resume_breakpoint (ecs
->event_thread
);
5012 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
5016 /* We come here if we hit a breakpoint but should not stop for it.
5017 Possibly we also were stepping and should stop for that. So fall
5018 through and test for stepping. But, if not stepping, do not
5021 /* In all-stop mode, if we're currently stepping but have stopped in
5022 some other thread, we need to switch back to the stepped thread. */
5023 if (switch_back_to_stepped_thread (ecs
))
5026 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
5029 fprintf_unfiltered (gdb_stdlog
,
5030 "infrun: step-resume breakpoint is inserted\n");
5032 /* Having a step-resume breakpoint overrides anything
5033 else having to do with stepping commands until
5034 that breakpoint is reached. */
5039 if (ecs
->event_thread
->control
.step_range_end
== 0)
5042 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
5043 /* Likewise if we aren't even stepping. */
5048 /* Re-fetch current thread's frame in case the code above caused
5049 the frame cache to be re-initialized, making our FRAME variable
5050 a dangling pointer. */
5051 frame
= get_current_frame ();
5052 gdbarch
= get_frame_arch (frame
);
5053 fill_in_stop_func (gdbarch
, ecs
);
5055 /* If stepping through a line, keep going if still within it.
5057 Note that step_range_end is the address of the first instruction
5058 beyond the step range, and NOT the address of the last instruction
5061 Note also that during reverse execution, we may be stepping
5062 through a function epilogue and therefore must detect when
5063 the current-frame changes in the middle of a line. */
5065 if (pc_in_thread_step_range (stop_pc
, ecs
->event_thread
)
5066 && (execution_direction
!= EXEC_REVERSE
5067 || frame_id_eq (get_frame_id (frame
),
5068 ecs
->event_thread
->control
.step_frame_id
)))
5072 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
5073 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
5074 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
5076 /* Tentatively re-enable range stepping; `resume' disables it if
5077 necessary (e.g., if we're stepping over a breakpoint or we
5078 have software watchpoints). */
5079 ecs
->event_thread
->control
.may_range_step
= 1;
5081 /* When stepping backward, stop at beginning of line range
5082 (unless it's the function entry point, in which case
5083 keep going back to the call point). */
5084 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
5085 && stop_pc
!= ecs
->stop_func_start
5086 && execution_direction
== EXEC_REVERSE
)
5087 end_stepping_range (ecs
);
5094 /* We stepped out of the stepping range. */
5096 /* If we are stepping at the source level and entered the runtime
5097 loader dynamic symbol resolution code...
5099 EXEC_FORWARD: we keep on single stepping until we exit the run
5100 time loader code and reach the callee's address.
5102 EXEC_REVERSE: we've already executed the callee (backward), and
5103 the runtime loader code is handled just like any other
5104 undebuggable function call. Now we need only keep stepping
5105 backward through the trampoline code, and that's handled further
5106 down, so there is nothing for us to do here. */
5108 if (execution_direction
!= EXEC_REVERSE
5109 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
5110 && in_solib_dynsym_resolve_code (stop_pc
))
5112 CORE_ADDR pc_after_resolver
=
5113 gdbarch_skip_solib_resolver (gdbarch
, stop_pc
);
5116 fprintf_unfiltered (gdb_stdlog
,
5117 "infrun: stepped into dynsym resolve code\n");
5119 if (pc_after_resolver
)
5121 /* Set up a step-resume breakpoint at the address
5122 indicated by SKIP_SOLIB_RESOLVER. */
5123 struct symtab_and_line sr_sal
;
5126 sr_sal
.pc
= pc_after_resolver
;
5127 sr_sal
.pspace
= get_frame_program_space (frame
);
5129 insert_step_resume_breakpoint_at_sal (gdbarch
,
5130 sr_sal
, null_frame_id
);
5137 if (ecs
->event_thread
->control
.step_range_end
!= 1
5138 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
5139 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
5140 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
5143 fprintf_unfiltered (gdb_stdlog
,
5144 "infrun: stepped into signal trampoline\n");
5145 /* The inferior, while doing a "step" or "next", has ended up in
5146 a signal trampoline (either by a signal being delivered or by
5147 the signal handler returning). Just single-step until the
5148 inferior leaves the trampoline (either by calling the handler
5154 /* If we're in the return path from a shared library trampoline,
5155 we want to proceed through the trampoline when stepping. */
5156 /* macro/2012-04-25: This needs to come before the subroutine
5157 call check below as on some targets return trampolines look
5158 like subroutine calls (MIPS16 return thunks). */
5159 if (gdbarch_in_solib_return_trampoline (gdbarch
,
5160 stop_pc
, ecs
->stop_func_name
)
5161 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
5163 /* Determine where this trampoline returns. */
5164 CORE_ADDR real_stop_pc
;
5166 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
5169 fprintf_unfiltered (gdb_stdlog
,
5170 "infrun: stepped into solib return tramp\n");
5172 /* Only proceed through if we know where it's going. */
5175 /* And put the step-breakpoint there and go until there. */
5176 struct symtab_and_line sr_sal
;
5178 init_sal (&sr_sal
); /* initialize to zeroes */
5179 sr_sal
.pc
= real_stop_pc
;
5180 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
5181 sr_sal
.pspace
= get_frame_program_space (frame
);
5183 /* Do not specify what the fp should be when we stop since
5184 on some machines the prologue is where the new fp value
5186 insert_step_resume_breakpoint_at_sal (gdbarch
,
5187 sr_sal
, null_frame_id
);
5189 /* Restart without fiddling with the step ranges or
5196 /* Check for subroutine calls. The check for the current frame
5197 equalling the step ID is not necessary - the check of the
5198 previous frame's ID is sufficient - but it is a common case and
5199 cheaper than checking the previous frame's ID.
5201 NOTE: frame_id_eq will never report two invalid frame IDs as
5202 being equal, so to get into this block, both the current and
5203 previous frame must have valid frame IDs. */
5204 /* The outer_frame_id check is a heuristic to detect stepping
5205 through startup code. If we step over an instruction which
5206 sets the stack pointer from an invalid value to a valid value,
5207 we may detect that as a subroutine call from the mythical
5208 "outermost" function. This could be fixed by marking
5209 outermost frames as !stack_p,code_p,special_p. Then the
5210 initial outermost frame, before sp was valid, would
5211 have code_addr == &_start. See the comment in frame_id_eq
5213 if (!frame_id_eq (get_stack_frame_id (frame
),
5214 ecs
->event_thread
->control
.step_stack_frame_id
)
5215 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
5216 ecs
->event_thread
->control
.step_stack_frame_id
)
5217 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
5219 || (ecs
->event_thread
->control
.step_start_function
5220 != find_pc_function (stop_pc
)))))
5222 CORE_ADDR real_stop_pc
;
5225 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
5227 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
5229 /* I presume that step_over_calls is only 0 when we're
5230 supposed to be stepping at the assembly language level
5231 ("stepi"). Just stop. */
5232 /* And this works the same backward as frontward. MVS */
5233 end_stepping_range (ecs
);
5237 /* Reverse stepping through solib trampolines. */
5239 if (execution_direction
== EXEC_REVERSE
5240 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
5241 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
5242 || (ecs
->stop_func_start
== 0
5243 && in_solib_dynsym_resolve_code (stop_pc
))))
5245 /* Any solib trampoline code can be handled in reverse
5246 by simply continuing to single-step. We have already
5247 executed the solib function (backwards), and a few
5248 steps will take us back through the trampoline to the
5254 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
5256 /* We're doing a "next".
5258 Normal (forward) execution: set a breakpoint at the
5259 callee's return address (the address at which the caller
5262 Reverse (backward) execution. set the step-resume
5263 breakpoint at the start of the function that we just
5264 stepped into (backwards), and continue to there. When we
5265 get there, we'll need to single-step back to the caller. */
5267 if (execution_direction
== EXEC_REVERSE
)
5269 /* If we're already at the start of the function, we've either
5270 just stepped backward into a single instruction function,
5271 or stepped back out of a signal handler to the first instruction
5272 of the function. Just keep going, which will single-step back
5274 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
5276 struct symtab_and_line sr_sal
;
5278 /* Normal function call return (static or dynamic). */
5280 sr_sal
.pc
= ecs
->stop_func_start
;
5281 sr_sal
.pspace
= get_frame_program_space (frame
);
5282 insert_step_resume_breakpoint_at_sal (gdbarch
,
5283 sr_sal
, null_frame_id
);
5287 insert_step_resume_breakpoint_at_caller (frame
);
5293 /* If we are in a function call trampoline (a stub between the
5294 calling routine and the real function), locate the real
5295 function. That's what tells us (a) whether we want to step
5296 into it at all, and (b) what prologue we want to run to the
5297 end of, if we do step into it. */
5298 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
5299 if (real_stop_pc
== 0)
5300 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
5301 if (real_stop_pc
!= 0)
5302 ecs
->stop_func_start
= real_stop_pc
;
5304 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
5306 struct symtab_and_line sr_sal
;
5309 sr_sal
.pc
= ecs
->stop_func_start
;
5310 sr_sal
.pspace
= get_frame_program_space (frame
);
5312 insert_step_resume_breakpoint_at_sal (gdbarch
,
5313 sr_sal
, null_frame_id
);
5318 /* If we have line number information for the function we are
5319 thinking of stepping into and the function isn't on the skip
5322 If there are several symtabs at that PC (e.g. with include
5323 files), just want to know whether *any* of them have line
5324 numbers. find_pc_line handles this. */
5326 struct symtab_and_line tmp_sal
;
5328 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
5329 if (tmp_sal
.line
!= 0
5330 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
5333 if (execution_direction
== EXEC_REVERSE
)
5334 handle_step_into_function_backward (gdbarch
, ecs
);
5336 handle_step_into_function (gdbarch
, ecs
);
5341 /* If we have no line number and the step-stop-if-no-debug is
5342 set, we stop the step so that the user has a chance to switch
5343 in assembly mode. */
5344 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
5345 && step_stop_if_no_debug
)
5347 end_stepping_range (ecs
);
5351 if (execution_direction
== EXEC_REVERSE
)
5353 /* If we're already at the start of the function, we've either just
5354 stepped backward into a single instruction function without line
5355 number info, or stepped back out of a signal handler to the first
5356 instruction of the function without line number info. Just keep
5357 going, which will single-step back to the caller. */
5358 if (ecs
->stop_func_start
!= stop_pc
)
5360 /* Set a breakpoint at callee's start address.
5361 From there we can step once and be back in the caller. */
5362 struct symtab_and_line sr_sal
;
5365 sr_sal
.pc
= ecs
->stop_func_start
;
5366 sr_sal
.pspace
= get_frame_program_space (frame
);
5367 insert_step_resume_breakpoint_at_sal (gdbarch
,
5368 sr_sal
, null_frame_id
);
5372 /* Set a breakpoint at callee's return address (the address
5373 at which the caller will resume). */
5374 insert_step_resume_breakpoint_at_caller (frame
);
5380 /* Reverse stepping through solib trampolines. */
5382 if (execution_direction
== EXEC_REVERSE
5383 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
5385 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
5386 || (ecs
->stop_func_start
== 0
5387 && in_solib_dynsym_resolve_code (stop_pc
)))
5389 /* Any solib trampoline code can be handled in reverse
5390 by simply continuing to single-step. We have already
5391 executed the solib function (backwards), and a few
5392 steps will take us back through the trampoline to the
5397 else if (in_solib_dynsym_resolve_code (stop_pc
))
5399 /* Stepped backward into the solib dynsym resolver.
5400 Set a breakpoint at its start and continue, then
5401 one more step will take us out. */
5402 struct symtab_and_line sr_sal
;
5405 sr_sal
.pc
= ecs
->stop_func_start
;
5406 sr_sal
.pspace
= get_frame_program_space (frame
);
5407 insert_step_resume_breakpoint_at_sal (gdbarch
,
5408 sr_sal
, null_frame_id
);
5414 stop_pc_sal
= find_pc_line (stop_pc
, 0);
5416 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5417 the trampoline processing logic, however, there are some trampolines
5418 that have no names, so we should do trampoline handling first. */
5419 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
5420 && ecs
->stop_func_name
== NULL
5421 && stop_pc_sal
.line
== 0)
5424 fprintf_unfiltered (gdb_stdlog
,
5425 "infrun: stepped into undebuggable function\n");
5427 /* The inferior just stepped into, or returned to, an
5428 undebuggable function (where there is no debugging information
5429 and no line number corresponding to the address where the
5430 inferior stopped). Since we want to skip this kind of code,
5431 we keep going until the inferior returns from this
5432 function - unless the user has asked us not to (via
5433 set step-mode) or we no longer know how to get back
5434 to the call site. */
5435 if (step_stop_if_no_debug
5436 || !frame_id_p (frame_unwind_caller_id (frame
)))
5438 /* If we have no line number and the step-stop-if-no-debug
5439 is set, we stop the step so that the user has a chance to
5440 switch in assembly mode. */
5441 end_stepping_range (ecs
);
5446 /* Set a breakpoint at callee's return address (the address
5447 at which the caller will resume). */
5448 insert_step_resume_breakpoint_at_caller (frame
);
5454 if (ecs
->event_thread
->control
.step_range_end
== 1)
5456 /* It is stepi or nexti. We always want to stop stepping after
5459 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
5460 end_stepping_range (ecs
);
5464 if (stop_pc_sal
.line
== 0)
5466 /* We have no line number information. That means to stop
5467 stepping (does this always happen right after one instruction,
5468 when we do "s" in a function with no line numbers,
5469 or can this happen as a result of a return or longjmp?). */
5471 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
5472 end_stepping_range (ecs
);
5476 /* Look for "calls" to inlined functions, part one. If the inline
5477 frame machinery detected some skipped call sites, we have entered
5478 a new inline function. */
5480 if (frame_id_eq (get_frame_id (get_current_frame ()),
5481 ecs
->event_thread
->control
.step_frame_id
)
5482 && inline_skipped_frames (ecs
->ptid
))
5484 struct symtab_and_line call_sal
;
5487 fprintf_unfiltered (gdb_stdlog
,
5488 "infrun: stepped into inlined function\n");
5490 find_frame_sal (get_current_frame (), &call_sal
);
5492 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
5494 /* For "step", we're going to stop. But if the call site
5495 for this inlined function is on the same source line as
5496 we were previously stepping, go down into the function
5497 first. Otherwise stop at the call site. */
5499 if (call_sal
.line
== ecs
->event_thread
->current_line
5500 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
5501 step_into_inline_frame (ecs
->ptid
);
5503 end_stepping_range (ecs
);
5508 /* For "next", we should stop at the call site if it is on a
5509 different source line. Otherwise continue through the
5510 inlined function. */
5511 if (call_sal
.line
== ecs
->event_thread
->current_line
5512 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
5515 end_stepping_range (ecs
);
5520 /* Look for "calls" to inlined functions, part two. If we are still
5521 in the same real function we were stepping through, but we have
5522 to go further up to find the exact frame ID, we are stepping
5523 through a more inlined call beyond its call site. */
5525 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5526 && !frame_id_eq (get_frame_id (get_current_frame ()),
5527 ecs
->event_thread
->control
.step_frame_id
)
5528 && stepped_in_from (get_current_frame (),
5529 ecs
->event_thread
->control
.step_frame_id
))
5532 fprintf_unfiltered (gdb_stdlog
,
5533 "infrun: stepping through inlined function\n");
5535 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
5538 end_stepping_range (ecs
);
5542 if ((stop_pc
== stop_pc_sal
.pc
)
5543 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
5544 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
5546 /* We are at the start of a different line. So stop. Note that
5547 we don't stop if we step into the middle of a different line.
5548 That is said to make things like for (;;) statements work
5551 fprintf_unfiltered (gdb_stdlog
,
5552 "infrun: stepped to a different line\n");
5553 end_stepping_range (ecs
);
5557 /* We aren't done stepping.
5559 Optimize by setting the stepping range to the line.
5560 (We might not be in the original line, but if we entered a
5561 new line in mid-statement, we continue stepping. This makes
5562 things like for(;;) statements work better.) */
5564 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
5565 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
5566 ecs
->event_thread
->control
.may_range_step
= 1;
5567 set_step_info (frame
, stop_pc_sal
);
5570 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
5574 /* In all-stop mode, if we're currently stepping but have stopped in
5575 some other thread, we may need to switch back to the stepped
5576 thread. Returns true we set the inferior running, false if we left
5577 it stopped (and the event needs further processing). */
5580 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
5584 struct thread_info
*tp
;
5585 struct thread_info
*stepping_thread
;
5586 struct thread_info
*step_over
;
5588 /* If any thread is blocked on some internal breakpoint, and we
5589 simply need to step over that breakpoint to get it going
5590 again, do that first. */
5592 /* However, if we see an event for the stepping thread, then we
5593 know all other threads have been moved past their breakpoints
5594 already. Let the caller check whether the step is finished,
5595 etc., before deciding to move it past a breakpoint. */
5596 if (ecs
->event_thread
->control
.step_range_end
!= 0)
5599 /* Check if the current thread is blocked on an incomplete
5600 step-over, interrupted by a random signal. */
5601 if (ecs
->event_thread
->control
.trap_expected
5602 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
5606 fprintf_unfiltered (gdb_stdlog
,
5607 "infrun: need to finish step-over of [%s]\n",
5608 target_pid_to_str (ecs
->event_thread
->ptid
));
5614 /* Check if the current thread is blocked by a single-step
5615 breakpoint of another thread. */
5616 if (ecs
->hit_singlestep_breakpoint
)
5620 fprintf_unfiltered (gdb_stdlog
,
5621 "infrun: need to step [%s] over single-step "
5623 target_pid_to_str (ecs
->ptid
));
5629 /* Otherwise, we no longer expect a trap in the current thread.
5630 Clear the trap_expected flag before switching back -- this is
5631 what keep_going does as well, if we call it. */
5632 ecs
->event_thread
->control
.trap_expected
= 0;
5634 /* Likewise, clear the signal if it should not be passed. */
5635 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
5636 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5638 /* If scheduler locking applies even if not stepping, there's no
5639 need to walk over threads. Above we've checked whether the
5640 current thread is stepping. If some other thread not the
5641 event thread is stepping, then it must be that scheduler
5642 locking is not in effect. */
5643 if (schedlock_applies (ecs
->event_thread
))
5646 /* Look for the stepping/nexting thread, and check if any other
5647 thread other than the stepping thread needs to start a
5648 step-over. Do all step-overs before actually proceeding with
5650 stepping_thread
= NULL
;
5652 ALL_NON_EXITED_THREADS (tp
)
5654 /* Ignore threads of processes we're not resuming. */
5656 && ptid_get_pid (tp
->ptid
) != ptid_get_pid (inferior_ptid
))
5659 /* When stepping over a breakpoint, we lock all threads
5660 except the one that needs to move past the breakpoint.
5661 If a non-event thread has this set, the "incomplete
5662 step-over" check above should have caught it earlier. */
5663 gdb_assert (!tp
->control
.trap_expected
);
5665 /* Did we find the stepping thread? */
5666 if (tp
->control
.step_range_end
)
5668 /* Yep. There should only one though. */
5669 gdb_assert (stepping_thread
== NULL
);
5671 /* The event thread is handled at the top, before we
5673 gdb_assert (tp
!= ecs
->event_thread
);
5675 /* If some thread other than the event thread is
5676 stepping, then scheduler locking can't be in effect,
5677 otherwise we wouldn't have resumed the current event
5678 thread in the first place. */
5679 gdb_assert (!schedlock_applies (tp
));
5681 stepping_thread
= tp
;
5683 else if (thread_still_needs_step_over (tp
))
5687 /* At the top we've returned early if the event thread
5688 is stepping. If some other thread not the event
5689 thread is stepping, then scheduler locking can't be
5690 in effect, and we can resume this thread. No need to
5691 keep looking for the stepping thread then. */
5696 if (step_over
!= NULL
)
5701 fprintf_unfiltered (gdb_stdlog
,
5702 "infrun: need to step-over [%s]\n",
5703 target_pid_to_str (tp
->ptid
));
5706 /* Only the stepping thread should have this set. */
5707 gdb_assert (tp
->control
.step_range_end
== 0);
5709 ecs
->ptid
= tp
->ptid
;
5710 ecs
->event_thread
= tp
;
5711 switch_to_thread (ecs
->ptid
);
5716 if (stepping_thread
!= NULL
)
5718 struct frame_info
*frame
;
5719 struct gdbarch
*gdbarch
;
5721 tp
= stepping_thread
;
5723 /* If the stepping thread exited, then don't try to switch
5724 back and resume it, which could fail in several different
5725 ways depending on the target. Instead, just keep going.
5727 We can find a stepping dead thread in the thread list in
5730 - The target supports thread exit events, and when the
5731 target tries to delete the thread from the thread list,
5732 inferior_ptid pointed at the exiting thread. In such
5733 case, calling delete_thread does not really remove the
5734 thread from the list; instead, the thread is left listed,
5735 with 'exited' state.
5737 - The target's debug interface does not support thread
5738 exit events, and so we have no idea whatsoever if the
5739 previously stepping thread is still alive. For that
5740 reason, we need to synchronously query the target
5742 if (is_exited (tp
->ptid
)
5743 || !target_thread_alive (tp
->ptid
))
5746 fprintf_unfiltered (gdb_stdlog
,
5747 "infrun: not switching back to "
5748 "stepped thread, it has vanished\n");
5750 delete_thread (tp
->ptid
);
5756 fprintf_unfiltered (gdb_stdlog
,
5757 "infrun: switching back to stepped thread\n");
5759 ecs
->event_thread
= tp
;
5760 ecs
->ptid
= tp
->ptid
;
5761 context_switch (ecs
->ptid
);
5763 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5764 frame
= get_current_frame ();
5765 gdbarch
= get_frame_arch (frame
);
5767 /* If the PC of the thread we were trying to single-step has
5768 changed, then that thread has trapped or been signaled,
5769 but the event has not been reported to GDB yet. Re-poll
5770 the target looking for this particular thread's event
5771 (i.e. temporarily enable schedlock) by:
5773 - setting a break at the current PC
5774 - resuming that particular thread, only (by setting
5777 This prevents us continuously moving the single-step
5778 breakpoint forward, one instruction at a time,
5781 if (stop_pc
!= tp
->prev_pc
)
5786 fprintf_unfiltered (gdb_stdlog
,
5787 "infrun: expected thread advanced also\n");
5789 /* Clear the info of the previous step-over, as it's no
5790 longer valid. It's what keep_going would do too, if
5791 we called it. Must do this before trying to insert
5792 the sss breakpoint, otherwise if we were previously
5793 trying to step over this exact address in another
5794 thread, the breakpoint ends up not installed. */
5795 clear_step_over_info ();
5797 insert_single_step_breakpoint (get_frame_arch (frame
),
5798 get_frame_address_space (frame
),
5801 resume_ptid
= user_visible_resume_ptid (tp
->control
.stepping_command
);
5802 do_target_resume (resume_ptid
,
5803 currently_stepping (tp
), GDB_SIGNAL_0
);
5804 prepare_to_wait (ecs
);
5809 fprintf_unfiltered (gdb_stdlog
,
5810 "infrun: expected thread still "
5811 "hasn't advanced\n");
5821 /* Is thread TP in the middle of single-stepping? */
5824 currently_stepping (struct thread_info
*tp
)
5826 return ((tp
->control
.step_range_end
5827 && tp
->control
.step_resume_breakpoint
== NULL
)
5828 || tp
->control
.trap_expected
5829 || tp
->stepped_breakpoint
5830 || bpstat_should_step ());
5833 /* Inferior has stepped into a subroutine call with source code that
5834 we should not step over. Do step to the first line of code in
5838 handle_step_into_function (struct gdbarch
*gdbarch
,
5839 struct execution_control_state
*ecs
)
5841 struct compunit_symtab
*cust
;
5842 struct symtab_and_line stop_func_sal
, sr_sal
;
5844 fill_in_stop_func (gdbarch
, ecs
);
5846 cust
= find_pc_compunit_symtab (stop_pc
);
5847 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
5848 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
5849 ecs
->stop_func_start
);
5851 stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
5852 /* Use the step_resume_break to step until the end of the prologue,
5853 even if that involves jumps (as it seems to on the vax under
5855 /* If the prologue ends in the middle of a source line, continue to
5856 the end of that source line (if it is still within the function).
5857 Otherwise, just go to end of prologue. */
5858 if (stop_func_sal
.end
5859 && stop_func_sal
.pc
!= ecs
->stop_func_start
5860 && stop_func_sal
.end
< ecs
->stop_func_end
)
5861 ecs
->stop_func_start
= stop_func_sal
.end
;
5863 /* Architectures which require breakpoint adjustment might not be able
5864 to place a breakpoint at the computed address. If so, the test
5865 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5866 ecs->stop_func_start to an address at which a breakpoint may be
5867 legitimately placed.
5869 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5870 made, GDB will enter an infinite loop when stepping through
5871 optimized code consisting of VLIW instructions which contain
5872 subinstructions corresponding to different source lines. On
5873 FR-V, it's not permitted to place a breakpoint on any but the
5874 first subinstruction of a VLIW instruction. When a breakpoint is
5875 set, GDB will adjust the breakpoint address to the beginning of
5876 the VLIW instruction. Thus, we need to make the corresponding
5877 adjustment here when computing the stop address. */
5879 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
5881 ecs
->stop_func_start
5882 = gdbarch_adjust_breakpoint_address (gdbarch
,
5883 ecs
->stop_func_start
);
5886 if (ecs
->stop_func_start
== stop_pc
)
5888 /* We are already there: stop now. */
5889 end_stepping_range (ecs
);
5894 /* Put the step-breakpoint there and go until there. */
5895 init_sal (&sr_sal
); /* initialize to zeroes */
5896 sr_sal
.pc
= ecs
->stop_func_start
;
5897 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
5898 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
5900 /* Do not specify what the fp should be when we stop since on
5901 some machines the prologue is where the new fp value is
5903 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
5905 /* And make sure stepping stops right away then. */
5906 ecs
->event_thread
->control
.step_range_end
5907 = ecs
->event_thread
->control
.step_range_start
;
5912 /* Inferior has stepped backward into a subroutine call with source
5913 code that we should not step over. Do step to the beginning of the
5914 last line of code in it. */
5917 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
5918 struct execution_control_state
*ecs
)
5920 struct compunit_symtab
*cust
;
5921 struct symtab_and_line stop_func_sal
;
5923 fill_in_stop_func (gdbarch
, ecs
);
5925 cust
= find_pc_compunit_symtab (stop_pc
);
5926 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
5927 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
5928 ecs
->stop_func_start
);
5930 stop_func_sal
= find_pc_line (stop_pc
, 0);
5932 /* OK, we're just going to keep stepping here. */
5933 if (stop_func_sal
.pc
== stop_pc
)
5935 /* We're there already. Just stop stepping now. */
5936 end_stepping_range (ecs
);
5940 /* Else just reset the step range and keep going.
5941 No step-resume breakpoint, they don't work for
5942 epilogues, which can have multiple entry paths. */
5943 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
5944 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
5950 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5951 This is used to both functions and to skip over code. */
5954 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
5955 struct symtab_and_line sr_sal
,
5956 struct frame_id sr_id
,
5957 enum bptype sr_type
)
5959 /* There should never be more than one step-resume or longjmp-resume
5960 breakpoint per thread, so we should never be setting a new
5961 step_resume_breakpoint when one is already active. */
5962 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
5963 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
5966 fprintf_unfiltered (gdb_stdlog
,
5967 "infrun: inserting step-resume breakpoint at %s\n",
5968 paddress (gdbarch
, sr_sal
.pc
));
5970 inferior_thread ()->control
.step_resume_breakpoint
5971 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
);
5975 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
5976 struct symtab_and_line sr_sal
,
5977 struct frame_id sr_id
)
5979 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
5984 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5985 This is used to skip a potential signal handler.
5987 This is called with the interrupted function's frame. The signal
5988 handler, when it returns, will resume the interrupted function at
5992 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
5994 struct symtab_and_line sr_sal
;
5995 struct gdbarch
*gdbarch
;
5997 gdb_assert (return_frame
!= NULL
);
5998 init_sal (&sr_sal
); /* initialize to zeros */
6000 gdbarch
= get_frame_arch (return_frame
);
6001 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
6002 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6003 sr_sal
.pspace
= get_frame_program_space (return_frame
);
6005 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
6006 get_stack_frame_id (return_frame
),
6010 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
6011 is used to skip a function after stepping into it (for "next" or if
6012 the called function has no debugging information).
6014 The current function has almost always been reached by single
6015 stepping a call or return instruction. NEXT_FRAME belongs to the
6016 current function, and the breakpoint will be set at the caller's
6019 This is a separate function rather than reusing
6020 insert_hp_step_resume_breakpoint_at_frame in order to avoid
6021 get_prev_frame, which may stop prematurely (see the implementation
6022 of frame_unwind_caller_id for an example). */
6025 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
6027 struct symtab_and_line sr_sal
;
6028 struct gdbarch
*gdbarch
;
6030 /* We shouldn't have gotten here if we don't know where the call site
6032 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
6034 init_sal (&sr_sal
); /* initialize to zeros */
6036 gdbarch
= frame_unwind_caller_arch (next_frame
);
6037 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
6038 frame_unwind_caller_pc (next_frame
));
6039 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6040 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
6042 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
6043 frame_unwind_caller_id (next_frame
));
6046 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
6047 new breakpoint at the target of a jmp_buf. The handling of
6048 longjmp-resume uses the same mechanisms used for handling
6049 "step-resume" breakpoints. */
6052 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
6054 /* There should never be more than one longjmp-resume breakpoint per
6055 thread, so we should never be setting a new
6056 longjmp_resume_breakpoint when one is already active. */
6057 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
6060 fprintf_unfiltered (gdb_stdlog
,
6061 "infrun: inserting longjmp-resume breakpoint at %s\n",
6062 paddress (gdbarch
, pc
));
6064 inferior_thread ()->control
.exception_resume_breakpoint
=
6065 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
);
6068 /* Insert an exception resume breakpoint. TP is the thread throwing
6069 the exception. The block B is the block of the unwinder debug hook
6070 function. FRAME is the frame corresponding to the call to this
6071 function. SYM is the symbol of the function argument holding the
6072 target PC of the exception. */
6075 insert_exception_resume_breakpoint (struct thread_info
*tp
,
6076 const struct block
*b
,
6077 struct frame_info
*frame
,
6082 struct symbol
*vsym
;
6083 struct value
*value
;
6085 struct breakpoint
*bp
;
6087 vsym
= lookup_symbol (SYMBOL_LINKAGE_NAME (sym
), b
, VAR_DOMAIN
, NULL
);
6088 value
= read_var_value (vsym
, frame
);
6089 /* If the value was optimized out, revert to the old behavior. */
6090 if (! value_optimized_out (value
))
6092 handler
= value_as_address (value
);
6095 fprintf_unfiltered (gdb_stdlog
,
6096 "infrun: exception resume at %lx\n",
6097 (unsigned long) handler
);
6099 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
6100 handler
, bp_exception_resume
);
6102 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
6105 bp
->thread
= tp
->num
;
6106 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
6109 CATCH (e
, RETURN_MASK_ERROR
)
6111 /* We want to ignore errors here. */
6116 /* A helper for check_exception_resume that sets an
6117 exception-breakpoint based on a SystemTap probe. */
6120 insert_exception_resume_from_probe (struct thread_info
*tp
,
6121 const struct bound_probe
*probe
,
6122 struct frame_info
*frame
)
6124 struct value
*arg_value
;
6126 struct breakpoint
*bp
;
6128 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
6132 handler
= value_as_address (arg_value
);
6135 fprintf_unfiltered (gdb_stdlog
,
6136 "infrun: exception resume at %s\n",
6137 paddress (get_objfile_arch (probe
->objfile
),
6140 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
6141 handler
, bp_exception_resume
);
6142 bp
->thread
= tp
->num
;
6143 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
6146 /* This is called when an exception has been intercepted. Check to
6147 see whether the exception's destination is of interest, and if so,
6148 set an exception resume breakpoint there. */
6151 check_exception_resume (struct execution_control_state
*ecs
,
6152 struct frame_info
*frame
)
6154 struct bound_probe probe
;
6155 struct symbol
*func
;
6157 /* First see if this exception unwinding breakpoint was set via a
6158 SystemTap probe point. If so, the probe has two arguments: the
6159 CFA and the HANDLER. We ignore the CFA, extract the handler, and
6160 set a breakpoint there. */
6161 probe
= find_probe_by_pc (get_frame_pc (frame
));
6164 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
6168 func
= get_frame_function (frame
);
6174 const struct block
*b
;
6175 struct block_iterator iter
;
6179 /* The exception breakpoint is a thread-specific breakpoint on
6180 the unwinder's debug hook, declared as:
6182 void _Unwind_DebugHook (void *cfa, void *handler);
6184 The CFA argument indicates the frame to which control is
6185 about to be transferred. HANDLER is the destination PC.
6187 We ignore the CFA and set a temporary breakpoint at HANDLER.
6188 This is not extremely efficient but it avoids issues in gdb
6189 with computing the DWARF CFA, and it also works even in weird
6190 cases such as throwing an exception from inside a signal
6193 b
= SYMBOL_BLOCK_VALUE (func
);
6194 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
6196 if (!SYMBOL_IS_ARGUMENT (sym
))
6203 insert_exception_resume_breakpoint (ecs
->event_thread
,
6209 CATCH (e
, RETURN_MASK_ERROR
)
6216 stop_waiting (struct execution_control_state
*ecs
)
6219 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
6221 clear_step_over_info ();
6223 /* Let callers know we don't want to wait for the inferior anymore. */
6224 ecs
->wait_some_more
= 0;
6227 /* Called when we should continue running the inferior, because the
6228 current event doesn't cause a user visible stop. This does the
6229 resuming part; waiting for the next event is done elsewhere. */
6232 keep_going (struct execution_control_state
*ecs
)
6234 /* Make sure normal_stop is called if we get a QUIT handled before
6236 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
6238 /* Save the pc before execution, to compare with pc after stop. */
6239 ecs
->event_thread
->prev_pc
6240 = regcache_read_pc (get_thread_regcache (ecs
->ptid
));
6242 if (ecs
->event_thread
->control
.trap_expected
6243 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
6245 /* We haven't yet gotten our trap, and either: intercepted a
6246 non-signal event (e.g., a fork); or took a signal which we
6247 are supposed to pass through to the inferior. Simply
6249 discard_cleanups (old_cleanups
);
6250 resume (ecs
->event_thread
->suspend
.stop_signal
);
6254 struct regcache
*regcache
= get_current_regcache ();
6258 /* Either the trap was not expected, but we are continuing
6259 anyway (if we got a signal, the user asked it be passed to
6262 We got our expected trap, but decided we should resume from
6265 We're going to run this baby now!
6267 Note that insert_breakpoints won't try to re-insert
6268 already inserted breakpoints. Therefore, we don't
6269 care if breakpoints were already inserted, or not. */
6271 /* If we need to step over a breakpoint, and we're not using
6272 displaced stepping to do so, insert all breakpoints
6273 (watchpoints, etc.) but the one we're stepping over, step one
6274 instruction, and then re-insert the breakpoint when that step
6277 remove_bp
= (ecs
->hit_singlestep_breakpoint
6278 || thread_still_needs_step_over (ecs
->event_thread
));
6279 remove_wps
= (ecs
->event_thread
->stepping_over_watchpoint
6280 && !target_have_steppable_watchpoint
);
6282 /* We can't use displaced stepping if we need to step past a
6283 watchpoint. The instruction copied to the scratch pad would
6284 still trigger the watchpoint. */
6287 || !use_displaced_stepping (get_regcache_arch (regcache
))))
6289 set_step_over_info (get_regcache_aspace (regcache
),
6290 regcache_read_pc (regcache
), remove_wps
);
6292 else if (remove_wps
)
6293 set_step_over_info (NULL
, 0, remove_wps
);
6295 clear_step_over_info ();
6297 /* Stop stepping if inserting breakpoints fails. */
6300 insert_breakpoints ();
6302 CATCH (e
, RETURN_MASK_ERROR
)
6304 exception_print (gdb_stderr
, e
);
6306 discard_cleanups (old_cleanups
);
6311 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
6313 /* Do not deliver GDB_SIGNAL_TRAP (except when the user
6314 explicitly specifies that such a signal should be delivered
6315 to the target program). Typically, that would occur when a
6316 user is debugging a target monitor on a simulator: the target
6317 monitor sets a breakpoint; the simulator encounters this
6318 breakpoint and halts the simulation handing control to GDB;
6319 GDB, noting that the stop address doesn't map to any known
6320 breakpoint, returns control back to the simulator; the
6321 simulator then delivers the hardware equivalent of a
6322 GDB_SIGNAL_TRAP to the program being debugged. */
6323 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6324 && !signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
6325 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6327 discard_cleanups (old_cleanups
);
6328 resume (ecs
->event_thread
->suspend
.stop_signal
);
6331 prepare_to_wait (ecs
);
6334 /* This function normally comes after a resume, before
6335 handle_inferior_event exits. It takes care of any last bits of
6336 housekeeping, and sets the all-important wait_some_more flag. */
6339 prepare_to_wait (struct execution_control_state
*ecs
)
6342 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
6344 /* This is the old end of the while loop. Let everybody know we
6345 want to wait for the inferior some more and get called again
6347 ecs
->wait_some_more
= 1;
6350 /* We are done with the step range of a step/next/si/ni command.
6351 Called once for each n of a "step n" operation. */
6354 end_stepping_range (struct execution_control_state
*ecs
)
6356 ecs
->event_thread
->control
.stop_step
= 1;
6360 /* Several print_*_reason functions to print why the inferior has stopped.
6361 We always print something when the inferior exits, or receives a signal.
6362 The rest of the cases are dealt with later on in normal_stop and
6363 print_it_typical. Ideally there should be a call to one of these
6364 print_*_reason functions functions from handle_inferior_event each time
6365 stop_waiting is called.
6367 Note that we don't call these directly, instead we delegate that to
6368 the interpreters, through observers. Interpreters then call these
6369 with whatever uiout is right. */
6372 print_end_stepping_range_reason (struct ui_out
*uiout
)
6374 /* For CLI-like interpreters, print nothing. */
6376 if (ui_out_is_mi_like_p (uiout
))
6378 ui_out_field_string (uiout
, "reason",
6379 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
6384 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
6386 annotate_signalled ();
6387 if (ui_out_is_mi_like_p (uiout
))
6389 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
6390 ui_out_text (uiout
, "\nProgram terminated with signal ");
6391 annotate_signal_name ();
6392 ui_out_field_string (uiout
, "signal-name",
6393 gdb_signal_to_name (siggnal
));
6394 annotate_signal_name_end ();
6395 ui_out_text (uiout
, ", ");
6396 annotate_signal_string ();
6397 ui_out_field_string (uiout
, "signal-meaning",
6398 gdb_signal_to_string (siggnal
));
6399 annotate_signal_string_end ();
6400 ui_out_text (uiout
, ".\n");
6401 ui_out_text (uiout
, "The program no longer exists.\n");
6405 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
6407 struct inferior
*inf
= current_inferior ();
6408 const char *pidstr
= target_pid_to_str (pid_to_ptid (inf
->pid
));
6410 annotate_exited (exitstatus
);
6413 if (ui_out_is_mi_like_p (uiout
))
6414 ui_out_field_string (uiout
, "reason",
6415 async_reason_lookup (EXEC_ASYNC_EXITED
));
6416 ui_out_text (uiout
, "[Inferior ");
6417 ui_out_text (uiout
, plongest (inf
->num
));
6418 ui_out_text (uiout
, " (");
6419 ui_out_text (uiout
, pidstr
);
6420 ui_out_text (uiout
, ") exited with code ");
6421 ui_out_field_fmt (uiout
, "exit-code", "0%o", (unsigned int) exitstatus
);
6422 ui_out_text (uiout
, "]\n");
6426 if (ui_out_is_mi_like_p (uiout
))
6428 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
6429 ui_out_text (uiout
, "[Inferior ");
6430 ui_out_text (uiout
, plongest (inf
->num
));
6431 ui_out_text (uiout
, " (");
6432 ui_out_text (uiout
, pidstr
);
6433 ui_out_text (uiout
, ") exited normally]\n");
6438 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
6442 if (siggnal
== GDB_SIGNAL_0
&& !ui_out_is_mi_like_p (uiout
))
6444 struct thread_info
*t
= inferior_thread ();
6446 ui_out_text (uiout
, "\n[");
6447 ui_out_field_string (uiout
, "thread-name",
6448 target_pid_to_str (t
->ptid
));
6449 ui_out_field_fmt (uiout
, "thread-id", "] #%d", t
->num
);
6450 ui_out_text (uiout
, " stopped");
6454 ui_out_text (uiout
, "\nProgram received signal ");
6455 annotate_signal_name ();
6456 if (ui_out_is_mi_like_p (uiout
))
6458 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
6459 ui_out_field_string (uiout
, "signal-name",
6460 gdb_signal_to_name (siggnal
));
6461 annotate_signal_name_end ();
6462 ui_out_text (uiout
, ", ");
6463 annotate_signal_string ();
6464 ui_out_field_string (uiout
, "signal-meaning",
6465 gdb_signal_to_string (siggnal
));
6466 annotate_signal_string_end ();
6468 ui_out_text (uiout
, ".\n");
6472 print_no_history_reason (struct ui_out
*uiout
)
6474 ui_out_text (uiout
, "\nNo more reverse-execution history.\n");
6477 /* Print current location without a level number, if we have changed
6478 functions or hit a breakpoint. Print source line if we have one.
6479 bpstat_print contains the logic deciding in detail what to print,
6480 based on the event(s) that just occurred. */
6483 print_stop_event (struct target_waitstatus
*ws
)
6487 int do_frame_printing
= 1;
6488 struct thread_info
*tp
= inferior_thread ();
6490 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
6494 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
6495 should) carry around the function and does (or should) use
6496 that when doing a frame comparison. */
6497 if (tp
->control
.stop_step
6498 && frame_id_eq (tp
->control
.step_frame_id
,
6499 get_frame_id (get_current_frame ()))
6500 && tp
->control
.step_start_function
== find_pc_function (stop_pc
))
6502 /* Finished step, just print source line. */
6503 source_flag
= SRC_LINE
;
6507 /* Print location and source line. */
6508 source_flag
= SRC_AND_LOC
;
6511 case PRINT_SRC_AND_LOC
:
6512 /* Print location and source line. */
6513 source_flag
= SRC_AND_LOC
;
6515 case PRINT_SRC_ONLY
:
6516 source_flag
= SRC_LINE
;
6519 /* Something bogus. */
6520 source_flag
= SRC_LINE
;
6521 do_frame_printing
= 0;
6524 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
6527 /* The behavior of this routine with respect to the source
6529 SRC_LINE: Print only source line
6530 LOCATION: Print only location
6531 SRC_AND_LOC: Print location and source line. */
6532 if (do_frame_printing
)
6533 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
6535 /* Display the auto-display expressions. */
6539 /* Here to return control to GDB when the inferior stops for real.
6540 Print appropriate messages, remove breakpoints, give terminal our modes.
6542 STOP_PRINT_FRAME nonzero means print the executing frame
6543 (pc, function, args, file, line number and line text).
6544 BREAKPOINTS_FAILED nonzero means stop was due to error
6545 attempting to insert breakpoints. */
6550 struct target_waitstatus last
;
6552 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
6554 get_last_target_status (&last_ptid
, &last
);
6556 /* If an exception is thrown from this point on, make sure to
6557 propagate GDB's knowledge of the executing state to the
6558 frontend/user running state. A QUIT is an easy exception to see
6559 here, so do this before any filtered output. */
6561 make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
6562 else if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
6563 && last
.kind
!= TARGET_WAITKIND_EXITED
6564 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
6565 make_cleanup (finish_thread_state_cleanup
, &inferior_ptid
);
6567 /* As we're presenting a stop, and potentially removing breakpoints,
6568 update the thread list so we can tell whether there are threads
6569 running on the target. With target remote, for example, we can
6570 only learn about new threads when we explicitly update the thread
6571 list. Do this before notifying the interpreters about signal
6572 stops, end of stepping ranges, etc., so that the "new thread"
6573 output is emitted before e.g., "Program received signal FOO",
6574 instead of after. */
6575 update_thread_list ();
6577 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
6578 observer_notify_signal_received (inferior_thread ()->suspend
.stop_signal
);
6580 /* As with the notification of thread events, we want to delay
6581 notifying the user that we've switched thread context until
6582 the inferior actually stops.
6584 There's no point in saying anything if the inferior has exited.
6585 Note that SIGNALLED here means "exited with a signal", not
6586 "received a signal".
6588 Also skip saying anything in non-stop mode. In that mode, as we
6589 don't want GDB to switch threads behind the user's back, to avoid
6590 races where the user is typing a command to apply to thread x,
6591 but GDB switches to thread y before the user finishes entering
6592 the command, fetch_inferior_event installs a cleanup to restore
6593 the current thread back to the thread the user had selected right
6594 after this event is handled, so we're not really switching, only
6595 informing of a stop. */
6597 && !ptid_equal (previous_inferior_ptid
, inferior_ptid
)
6598 && target_has_execution
6599 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
6600 && last
.kind
!= TARGET_WAITKIND_EXITED
6601 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
6603 target_terminal_ours_for_output ();
6604 printf_filtered (_("[Switching to %s]\n"),
6605 target_pid_to_str (inferior_ptid
));
6606 annotate_thread_changed ();
6607 previous_inferior_ptid
= inferior_ptid
;
6610 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
6612 gdb_assert (sync_execution
|| !target_can_async_p ());
6614 target_terminal_ours_for_output ();
6615 printf_filtered (_("No unwaited-for children left.\n"));
6618 /* Note: this depends on the update_thread_list call above. */
6619 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
6621 if (remove_breakpoints ())
6623 target_terminal_ours_for_output ();
6624 printf_filtered (_("Cannot remove breakpoints because "
6625 "program is no longer writable.\nFurther "
6626 "execution is probably impossible.\n"));
6630 /* If an auto-display called a function and that got a signal,
6631 delete that auto-display to avoid an infinite recursion. */
6633 if (stopped_by_random_signal
)
6634 disable_current_display ();
6636 /* Notify observers if we finished a "step"-like command, etc. */
6637 if (target_has_execution
6638 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
6639 && last
.kind
!= TARGET_WAITKIND_EXITED
6640 && inferior_thread ()->control
.stop_step
)
6642 /* But not if in the middle of doing a "step n" operation for
6644 if (inferior_thread ()->step_multi
)
6647 observer_notify_end_stepping_range ();
6650 target_terminal_ours ();
6651 async_enable_stdin ();
6653 /* Set the current source location. This will also happen if we
6654 display the frame below, but the current SAL will be incorrect
6655 during a user hook-stop function. */
6656 if (has_stack_frames () && !stop_stack_dummy
)
6657 set_current_sal_from_frame (get_current_frame ());
6659 /* Let the user/frontend see the threads as stopped, but do nothing
6660 if the thread was running an infcall. We may be e.g., evaluating
6661 a breakpoint condition. In that case, the thread had state
6662 THREAD_RUNNING before the infcall, and shall remain set to
6663 running, all without informing the user/frontend about state
6664 transition changes. If this is actually a call command, then the
6665 thread was originally already stopped, so there's no state to
6667 if (target_has_execution
&& inferior_thread ()->control
.in_infcall
)
6668 discard_cleanups (old_chain
);
6670 do_cleanups (old_chain
);
6672 /* Look up the hook_stop and run it (CLI internally handles problem
6673 of stop_command's pre-hook not existing). */
6675 catch_errors (hook_stop_stub
, stop_command
,
6676 "Error while running hook_stop:\n", RETURN_MASK_ALL
);
6678 if (!has_stack_frames ())
6681 if (last
.kind
== TARGET_WAITKIND_SIGNALLED
6682 || last
.kind
== TARGET_WAITKIND_EXITED
)
6685 /* Select innermost stack frame - i.e., current frame is frame 0,
6686 and current location is based on that.
6687 Don't do this on return from a stack dummy routine,
6688 or if the program has exited. */
6690 if (!stop_stack_dummy
)
6692 select_frame (get_current_frame ());
6694 /* If --batch-silent is enabled then there's no need to print the current
6695 source location, and to try risks causing an error message about
6696 missing source files. */
6697 if (stop_print_frame
&& !batch_silent
)
6698 print_stop_event (&last
);
6701 /* Save the function value return registers, if we care.
6702 We might be about to restore their previous contents. */
6703 if (inferior_thread ()->control
.proceed_to_finish
6704 && execution_direction
!= EXEC_REVERSE
)
6706 /* This should not be necessary. */
6708 regcache_xfree (stop_registers
);
6710 /* NB: The copy goes through to the target picking up the value of
6711 all the registers. */
6712 stop_registers
= regcache_dup (get_current_regcache ());
6715 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
6717 /* Pop the empty frame that contains the stack dummy.
6718 This also restores inferior state prior to the call
6719 (struct infcall_suspend_state). */
6720 struct frame_info
*frame
= get_current_frame ();
6722 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
6724 /* frame_pop() calls reinit_frame_cache as the last thing it
6725 does which means there's currently no selected frame. We
6726 don't need to re-establish a selected frame if the dummy call
6727 returns normally, that will be done by
6728 restore_infcall_control_state. However, we do have to handle
6729 the case where the dummy call is returning after being
6730 stopped (e.g. the dummy call previously hit a breakpoint).
6731 We can't know which case we have so just always re-establish
6732 a selected frame here. */
6733 select_frame (get_current_frame ());
6737 annotate_stopped ();
6739 /* Suppress the stop observer if we're in the middle of:
6741 - a step n (n > 1), as there still more steps to be done.
6743 - a "finish" command, as the observer will be called in
6744 finish_command_continuation, so it can include the inferior
6745 function's return value.
6747 - calling an inferior function, as we pretend we inferior didn't
6748 run at all. The return value of the call is handled by the
6749 expression evaluator, through call_function_by_hand. */
6751 if (!target_has_execution
6752 || last
.kind
== TARGET_WAITKIND_SIGNALLED
6753 || last
.kind
== TARGET_WAITKIND_EXITED
6754 || last
.kind
== TARGET_WAITKIND_NO_RESUMED
6755 || (!(inferior_thread ()->step_multi
6756 && inferior_thread ()->control
.stop_step
)
6757 && !(inferior_thread ()->control
.stop_bpstat
6758 && inferior_thread ()->control
.proceed_to_finish
)
6759 && !inferior_thread ()->control
.in_infcall
))
6761 if (!ptid_equal (inferior_ptid
, null_ptid
))
6762 observer_notify_normal_stop (inferior_thread ()->control
.stop_bpstat
,
6765 observer_notify_normal_stop (NULL
, stop_print_frame
);
6768 if (target_has_execution
)
6770 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
6771 && last
.kind
!= TARGET_WAITKIND_EXITED
)
6772 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6773 Delete any breakpoint that is to be deleted at the next stop. */
6774 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
6777 /* Try to get rid of automatically added inferiors that are no
6778 longer needed. Keeping those around slows down things linearly.
6779 Note that this never removes the current inferior. */
6784 hook_stop_stub (void *cmd
)
6786 execute_cmd_pre_hook ((struct cmd_list_element
*) cmd
);
6791 signal_stop_state (int signo
)
6793 return signal_stop
[signo
];
6797 signal_print_state (int signo
)
6799 return signal_print
[signo
];
6803 signal_pass_state (int signo
)
6805 return signal_program
[signo
];
6809 signal_cache_update (int signo
)
6813 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
6814 signal_cache_update (signo
);
6819 signal_pass
[signo
] = (signal_stop
[signo
] == 0
6820 && signal_print
[signo
] == 0
6821 && signal_program
[signo
] == 1
6822 && signal_catch
[signo
] == 0);
6826 signal_stop_update (int signo
, int state
)
6828 int ret
= signal_stop
[signo
];
6830 signal_stop
[signo
] = state
;
6831 signal_cache_update (signo
);
6836 signal_print_update (int signo
, int state
)
6838 int ret
= signal_print
[signo
];
6840 signal_print
[signo
] = state
;
6841 signal_cache_update (signo
);
6846 signal_pass_update (int signo
, int state
)
6848 int ret
= signal_program
[signo
];
6850 signal_program
[signo
] = state
;
6851 signal_cache_update (signo
);
6855 /* Update the global 'signal_catch' from INFO and notify the
6859 signal_catch_update (const unsigned int *info
)
6863 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
6864 signal_catch
[i
] = info
[i
] > 0;
6865 signal_cache_update (-1);
6866 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
6870 sig_print_header (void)
6872 printf_filtered (_("Signal Stop\tPrint\tPass "
6873 "to program\tDescription\n"));
6877 sig_print_info (enum gdb_signal oursig
)
6879 const char *name
= gdb_signal_to_name (oursig
);
6880 int name_padding
= 13 - strlen (name
);
6882 if (name_padding
<= 0)
6885 printf_filtered ("%s", name
);
6886 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
6887 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
6888 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
6889 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
6890 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
6893 /* Specify how various signals in the inferior should be handled. */
6896 handle_command (char *args
, int from_tty
)
6899 int digits
, wordlen
;
6900 int sigfirst
, signum
, siglast
;
6901 enum gdb_signal oursig
;
6904 unsigned char *sigs
;
6905 struct cleanup
*old_chain
;
6909 error_no_arg (_("signal to handle"));
6912 /* Allocate and zero an array of flags for which signals to handle. */
6914 nsigs
= (int) GDB_SIGNAL_LAST
;
6915 sigs
= (unsigned char *) alloca (nsigs
);
6916 memset (sigs
, 0, nsigs
);
6918 /* Break the command line up into args. */
6920 argv
= gdb_buildargv (args
);
6921 old_chain
= make_cleanup_freeargv (argv
);
6923 /* Walk through the args, looking for signal oursigs, signal names, and
6924 actions. Signal numbers and signal names may be interspersed with
6925 actions, with the actions being performed for all signals cumulatively
6926 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6928 while (*argv
!= NULL
)
6930 wordlen
= strlen (*argv
);
6931 for (digits
= 0; isdigit ((*argv
)[digits
]); digits
++)
6935 sigfirst
= siglast
= -1;
6937 if (wordlen
>= 1 && !strncmp (*argv
, "all", wordlen
))
6939 /* Apply action to all signals except those used by the
6940 debugger. Silently skip those. */
6943 siglast
= nsigs
- 1;
6945 else if (wordlen
>= 1 && !strncmp (*argv
, "stop", wordlen
))
6947 SET_SIGS (nsigs
, sigs
, signal_stop
);
6948 SET_SIGS (nsigs
, sigs
, signal_print
);
6950 else if (wordlen
>= 1 && !strncmp (*argv
, "ignore", wordlen
))
6952 UNSET_SIGS (nsigs
, sigs
, signal_program
);
6954 else if (wordlen
>= 2 && !strncmp (*argv
, "print", wordlen
))
6956 SET_SIGS (nsigs
, sigs
, signal_print
);
6958 else if (wordlen
>= 2 && !strncmp (*argv
, "pass", wordlen
))
6960 SET_SIGS (nsigs
, sigs
, signal_program
);
6962 else if (wordlen
>= 3 && !strncmp (*argv
, "nostop", wordlen
))
6964 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
6966 else if (wordlen
>= 3 && !strncmp (*argv
, "noignore", wordlen
))
6968 SET_SIGS (nsigs
, sigs
, signal_program
);
6970 else if (wordlen
>= 4 && !strncmp (*argv
, "noprint", wordlen
))
6972 UNSET_SIGS (nsigs
, sigs
, signal_print
);
6973 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
6975 else if (wordlen
>= 4 && !strncmp (*argv
, "nopass", wordlen
))
6977 UNSET_SIGS (nsigs
, sigs
, signal_program
);
6979 else if (digits
> 0)
6981 /* It is numeric. The numeric signal refers to our own
6982 internal signal numbering from target.h, not to host/target
6983 signal number. This is a feature; users really should be
6984 using symbolic names anyway, and the common ones like
6985 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6987 sigfirst
= siglast
= (int)
6988 gdb_signal_from_command (atoi (*argv
));
6989 if ((*argv
)[digits
] == '-')
6992 gdb_signal_from_command (atoi ((*argv
) + digits
+ 1));
6994 if (sigfirst
> siglast
)
6996 /* Bet he didn't figure we'd think of this case... */
7004 oursig
= gdb_signal_from_name (*argv
);
7005 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
7007 sigfirst
= siglast
= (int) oursig
;
7011 /* Not a number and not a recognized flag word => complain. */
7012 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv
);
7016 /* If any signal numbers or symbol names were found, set flags for
7017 which signals to apply actions to. */
7019 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
7021 switch ((enum gdb_signal
) signum
)
7023 case GDB_SIGNAL_TRAP
:
7024 case GDB_SIGNAL_INT
:
7025 if (!allsigs
&& !sigs
[signum
])
7027 if (query (_("%s is used by the debugger.\n\
7028 Are you sure you want to change it? "),
7029 gdb_signal_to_name ((enum gdb_signal
) signum
)))
7035 printf_unfiltered (_("Not confirmed, unchanged.\n"));
7036 gdb_flush (gdb_stdout
);
7041 case GDB_SIGNAL_DEFAULT
:
7042 case GDB_SIGNAL_UNKNOWN
:
7043 /* Make sure that "all" doesn't print these. */
7054 for (signum
= 0; signum
< nsigs
; signum
++)
7057 signal_cache_update (-1);
7058 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
7059 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
7063 /* Show the results. */
7064 sig_print_header ();
7065 for (; signum
< nsigs
; signum
++)
7067 sig_print_info (signum
);
7073 do_cleanups (old_chain
);
7076 /* Complete the "handle" command. */
7078 static VEC (char_ptr
) *
7079 handle_completer (struct cmd_list_element
*ignore
,
7080 const char *text
, const char *word
)
7082 VEC (char_ptr
) *vec_signals
, *vec_keywords
, *return_val
;
7083 static const char * const keywords
[] =
7097 vec_signals
= signal_completer (ignore
, text
, word
);
7098 vec_keywords
= complete_on_enum (keywords
, word
, word
);
7100 return_val
= VEC_merge (char_ptr
, vec_signals
, vec_keywords
);
7101 VEC_free (char_ptr
, vec_signals
);
7102 VEC_free (char_ptr
, vec_keywords
);
7107 gdb_signal_from_command (int num
)
7109 if (num
>= 1 && num
<= 15)
7110 return (enum gdb_signal
) num
;
7111 error (_("Only signals 1-15 are valid as numeric signals.\n\
7112 Use \"info signals\" for a list of symbolic signals."));
7115 /* Print current contents of the tables set by the handle command.
7116 It is possible we should just be printing signals actually used
7117 by the current target (but for things to work right when switching
7118 targets, all signals should be in the signal tables). */
7121 signals_info (char *signum_exp
, int from_tty
)
7123 enum gdb_signal oursig
;
7125 sig_print_header ();
7129 /* First see if this is a symbol name. */
7130 oursig
= gdb_signal_from_name (signum_exp
);
7131 if (oursig
== GDB_SIGNAL_UNKNOWN
)
7133 /* No, try numeric. */
7135 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
7137 sig_print_info (oursig
);
7141 printf_filtered ("\n");
7142 /* These ugly casts brought to you by the native VAX compiler. */
7143 for (oursig
= GDB_SIGNAL_FIRST
;
7144 (int) oursig
< (int) GDB_SIGNAL_LAST
;
7145 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
7149 if (oursig
!= GDB_SIGNAL_UNKNOWN
7150 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
7151 sig_print_info (oursig
);
7154 printf_filtered (_("\nUse the \"handle\" command "
7155 "to change these tables.\n"));
7158 /* Check if it makes sense to read $_siginfo from the current thread
7159 at this point. If not, throw an error. */
7162 validate_siginfo_access (void)
7164 /* No current inferior, no siginfo. */
7165 if (ptid_equal (inferior_ptid
, null_ptid
))
7166 error (_("No thread selected."));
7168 /* Don't try to read from a dead thread. */
7169 if (is_exited (inferior_ptid
))
7170 error (_("The current thread has terminated"));
7172 /* ... or from a spinning thread. */
7173 if (is_running (inferior_ptid
))
7174 error (_("Selected thread is running."));
7177 /* The $_siginfo convenience variable is a bit special. We don't know
7178 for sure the type of the value until we actually have a chance to
7179 fetch the data. The type can change depending on gdbarch, so it is
7180 also dependent on which thread you have selected.
7182 1. making $_siginfo be an internalvar that creates a new value on
7185 2. making the value of $_siginfo be an lval_computed value. */
7187 /* This function implements the lval_computed support for reading a
7191 siginfo_value_read (struct value
*v
)
7193 LONGEST transferred
;
7195 validate_siginfo_access ();
7198 target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
,
7200 value_contents_all_raw (v
),
7202 TYPE_LENGTH (value_type (v
)));
7204 if (transferred
!= TYPE_LENGTH (value_type (v
)))
7205 error (_("Unable to read siginfo"));
7208 /* This function implements the lval_computed support for writing a
7212 siginfo_value_write (struct value
*v
, struct value
*fromval
)
7214 LONGEST transferred
;
7216 validate_siginfo_access ();
7218 transferred
= target_write (¤t_target
,
7219 TARGET_OBJECT_SIGNAL_INFO
,
7221 value_contents_all_raw (fromval
),
7223 TYPE_LENGTH (value_type (fromval
)));
7225 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
7226 error (_("Unable to write siginfo"));
7229 static const struct lval_funcs siginfo_value_funcs
=
7235 /* Return a new value with the correct type for the siginfo object of
7236 the current thread using architecture GDBARCH. Return a void value
7237 if there's no object available. */
7239 static struct value
*
7240 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
7243 if (target_has_stack
7244 && !ptid_equal (inferior_ptid
, null_ptid
)
7245 && gdbarch_get_siginfo_type_p (gdbarch
))
7247 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
7249 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
7252 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
7256 /* infcall_suspend_state contains state about the program itself like its
7257 registers and any signal it received when it last stopped.
7258 This state must be restored regardless of how the inferior function call
7259 ends (either successfully, or after it hits a breakpoint or signal)
7260 if the program is to properly continue where it left off. */
7262 struct infcall_suspend_state
7264 struct thread_suspend_state thread_suspend
;
7265 #if 0 /* Currently unused and empty structures are not valid C. */
7266 struct inferior_suspend_state inferior_suspend
;
7271 struct regcache
*registers
;
7273 /* Format of SIGINFO_DATA or NULL if it is not present. */
7274 struct gdbarch
*siginfo_gdbarch
;
7276 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
7277 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
7278 content would be invalid. */
7279 gdb_byte
*siginfo_data
;
7282 struct infcall_suspend_state
*
7283 save_infcall_suspend_state (void)
7285 struct infcall_suspend_state
*inf_state
;
7286 struct thread_info
*tp
= inferior_thread ();
7288 struct inferior
*inf
= current_inferior ();
7290 struct regcache
*regcache
= get_current_regcache ();
7291 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
7292 gdb_byte
*siginfo_data
= NULL
;
7294 if (gdbarch_get_siginfo_type_p (gdbarch
))
7296 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
7297 size_t len
= TYPE_LENGTH (type
);
7298 struct cleanup
*back_to
;
7300 siginfo_data
= xmalloc (len
);
7301 back_to
= make_cleanup (xfree
, siginfo_data
);
7303 if (target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
7304 siginfo_data
, 0, len
) == len
)
7305 discard_cleanups (back_to
);
7308 /* Errors ignored. */
7309 do_cleanups (back_to
);
7310 siginfo_data
= NULL
;
7314 inf_state
= XCNEW (struct infcall_suspend_state
);
7318 inf_state
->siginfo_gdbarch
= gdbarch
;
7319 inf_state
->siginfo_data
= siginfo_data
;
7322 inf_state
->thread_suspend
= tp
->suspend
;
7323 #if 0 /* Currently unused and empty structures are not valid C. */
7324 inf_state
->inferior_suspend
= inf
->suspend
;
7327 /* run_inferior_call will not use the signal due to its `proceed' call with
7328 GDB_SIGNAL_0 anyway. */
7329 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7331 inf_state
->stop_pc
= stop_pc
;
7333 inf_state
->registers
= regcache_dup (regcache
);
7338 /* Restore inferior session state to INF_STATE. */
7341 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
7343 struct thread_info
*tp
= inferior_thread ();
7345 struct inferior
*inf
= current_inferior ();
7347 struct regcache
*regcache
= get_current_regcache ();
7348 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
7350 tp
->suspend
= inf_state
->thread_suspend
;
7351 #if 0 /* Currently unused and empty structures are not valid C. */
7352 inf
->suspend
= inf_state
->inferior_suspend
;
7355 stop_pc
= inf_state
->stop_pc
;
7357 if (inf_state
->siginfo_gdbarch
== gdbarch
)
7359 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
7361 /* Errors ignored. */
7362 target_write (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
7363 inf_state
->siginfo_data
, 0, TYPE_LENGTH (type
));
7366 /* The inferior can be gone if the user types "print exit(0)"
7367 (and perhaps other times). */
7368 if (target_has_execution
)
7369 /* NB: The register write goes through to the target. */
7370 regcache_cpy (regcache
, inf_state
->registers
);
7372 discard_infcall_suspend_state (inf_state
);
7376 do_restore_infcall_suspend_state_cleanup (void *state
)
7378 restore_infcall_suspend_state (state
);
7382 make_cleanup_restore_infcall_suspend_state
7383 (struct infcall_suspend_state
*inf_state
)
7385 return make_cleanup (do_restore_infcall_suspend_state_cleanup
, inf_state
);
7389 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
7391 regcache_xfree (inf_state
->registers
);
7392 xfree (inf_state
->siginfo_data
);
7397 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
7399 return inf_state
->registers
;
7402 /* infcall_control_state contains state regarding gdb's control of the
7403 inferior itself like stepping control. It also contains session state like
7404 the user's currently selected frame. */
7406 struct infcall_control_state
7408 struct thread_control_state thread_control
;
7409 struct inferior_control_state inferior_control
;
7412 enum stop_stack_kind stop_stack_dummy
;
7413 int stopped_by_random_signal
;
7414 int stop_after_trap
;
7416 /* ID if the selected frame when the inferior function call was made. */
7417 struct frame_id selected_frame_id
;
7420 /* Save all of the information associated with the inferior<==>gdb
7423 struct infcall_control_state
*
7424 save_infcall_control_state (void)
7426 struct infcall_control_state
*inf_status
= xmalloc (sizeof (*inf_status
));
7427 struct thread_info
*tp
= inferior_thread ();
7428 struct inferior
*inf
= current_inferior ();
7430 inf_status
->thread_control
= tp
->control
;
7431 inf_status
->inferior_control
= inf
->control
;
7433 tp
->control
.step_resume_breakpoint
= NULL
;
7434 tp
->control
.exception_resume_breakpoint
= NULL
;
7436 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
7437 chain. If caller's caller is walking the chain, they'll be happier if we
7438 hand them back the original chain when restore_infcall_control_state is
7440 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
7443 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
7444 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
7445 inf_status
->stop_after_trap
= stop_after_trap
;
7447 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
7453 restore_selected_frame (void *args
)
7455 struct frame_id
*fid
= (struct frame_id
*) args
;
7456 struct frame_info
*frame
;
7458 frame
= frame_find_by_id (*fid
);
7460 /* If inf_status->selected_frame_id is NULL, there was no previously
7464 warning (_("Unable to restore previously selected frame."));
7468 select_frame (frame
);
7473 /* Restore inferior session state to INF_STATUS. */
7476 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
7478 struct thread_info
*tp
= inferior_thread ();
7479 struct inferior
*inf
= current_inferior ();
7481 if (tp
->control
.step_resume_breakpoint
)
7482 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
7484 if (tp
->control
.exception_resume_breakpoint
)
7485 tp
->control
.exception_resume_breakpoint
->disposition
7486 = disp_del_at_next_stop
;
7488 /* Handle the bpstat_copy of the chain. */
7489 bpstat_clear (&tp
->control
.stop_bpstat
);
7491 tp
->control
= inf_status
->thread_control
;
7492 inf
->control
= inf_status
->inferior_control
;
7495 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
7496 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
7497 stop_after_trap
= inf_status
->stop_after_trap
;
7499 if (target_has_stack
)
7501 /* The point of catch_errors is that if the stack is clobbered,
7502 walking the stack might encounter a garbage pointer and
7503 error() trying to dereference it. */
7505 (restore_selected_frame
, &inf_status
->selected_frame_id
,
7506 "Unable to restore previously selected frame:\n",
7507 RETURN_MASK_ERROR
) == 0)
7508 /* Error in restoring the selected frame. Select the innermost
7510 select_frame (get_current_frame ());
7517 do_restore_infcall_control_state_cleanup (void *sts
)
7519 restore_infcall_control_state (sts
);
7523 make_cleanup_restore_infcall_control_state
7524 (struct infcall_control_state
*inf_status
)
7526 return make_cleanup (do_restore_infcall_control_state_cleanup
, inf_status
);
7530 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
7532 if (inf_status
->thread_control
.step_resume_breakpoint
)
7533 inf_status
->thread_control
.step_resume_breakpoint
->disposition
7534 = disp_del_at_next_stop
;
7536 if (inf_status
->thread_control
.exception_resume_breakpoint
)
7537 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
7538 = disp_del_at_next_stop
;
7540 /* See save_infcall_control_state for info on stop_bpstat. */
7541 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
7546 /* restore_inferior_ptid() will be used by the cleanup machinery
7547 to restore the inferior_ptid value saved in a call to
7548 save_inferior_ptid(). */
7551 restore_inferior_ptid (void *arg
)
7553 ptid_t
*saved_ptid_ptr
= arg
;
7555 inferior_ptid
= *saved_ptid_ptr
;
7559 /* Save the value of inferior_ptid so that it may be restored by a
7560 later call to do_cleanups(). Returns the struct cleanup pointer
7561 needed for later doing the cleanup. */
7564 save_inferior_ptid (void)
7566 ptid_t
*saved_ptid_ptr
;
7568 saved_ptid_ptr
= xmalloc (sizeof (ptid_t
));
7569 *saved_ptid_ptr
= inferior_ptid
;
7570 return make_cleanup (restore_inferior_ptid
, saved_ptid_ptr
);
7576 clear_exit_convenience_vars (void)
7578 clear_internalvar (lookup_internalvar ("_exitsignal"));
7579 clear_internalvar (lookup_internalvar ("_exitcode"));
7583 /* User interface for reverse debugging:
7584 Set exec-direction / show exec-direction commands
7585 (returns error unless target implements to_set_exec_direction method). */
7587 int execution_direction
= EXEC_FORWARD
;
7588 static const char exec_forward
[] = "forward";
7589 static const char exec_reverse
[] = "reverse";
7590 static const char *exec_direction
= exec_forward
;
7591 static const char *const exec_direction_names
[] = {
7598 set_exec_direction_func (char *args
, int from_tty
,
7599 struct cmd_list_element
*cmd
)
7601 if (target_can_execute_reverse
)
7603 if (!strcmp (exec_direction
, exec_forward
))
7604 execution_direction
= EXEC_FORWARD
;
7605 else if (!strcmp (exec_direction
, exec_reverse
))
7606 execution_direction
= EXEC_REVERSE
;
7610 exec_direction
= exec_forward
;
7611 error (_("Target does not support this operation."));
7616 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
7617 struct cmd_list_element
*cmd
, const char *value
)
7619 switch (execution_direction
) {
7621 fprintf_filtered (out
, _("Forward.\n"));
7624 fprintf_filtered (out
, _("Reverse.\n"));
7627 internal_error (__FILE__
, __LINE__
,
7628 _("bogus execution_direction value: %d"),
7629 (int) execution_direction
);
7634 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
7635 struct cmd_list_element
*c
, const char *value
)
7637 fprintf_filtered (file
, _("Resuming the execution of threads "
7638 "of all processes is %s.\n"), value
);
7641 /* Implementation of `siginfo' variable. */
7643 static const struct internalvar_funcs siginfo_funcs
=
7651 _initialize_infrun (void)
7655 struct cmd_list_element
*c
;
7657 add_info ("signals", signals_info
, _("\
7658 What debugger does when program gets various signals.\n\
7659 Specify a signal as argument to print info on that signal only."));
7660 add_info_alias ("handle", "signals", 0);
7662 c
= add_com ("handle", class_run
, handle_command
, _("\
7663 Specify how to handle signals.\n\
7664 Usage: handle SIGNAL [ACTIONS]\n\
7665 Args are signals and actions to apply to those signals.\n\
7666 If no actions are specified, the current settings for the specified signals\n\
7667 will be displayed instead.\n\
7669 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7670 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7671 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7672 The special arg \"all\" is recognized to mean all signals except those\n\
7673 used by the debugger, typically SIGTRAP and SIGINT.\n\
7675 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7676 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7677 Stop means reenter debugger if this signal happens (implies print).\n\
7678 Print means print a message if this signal happens.\n\
7679 Pass means let program see this signal; otherwise program doesn't know.\n\
7680 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7681 Pass and Stop may be combined.\n\
7683 Multiple signals may be specified. Signal numbers and signal names\n\
7684 may be interspersed with actions, with the actions being performed for\n\
7685 all signals cumulatively specified."));
7686 set_cmd_completer (c
, handle_completer
);
7689 stop_command
= add_cmd ("stop", class_obscure
,
7690 not_just_help_class_command
, _("\
7691 There is no `stop' command, but you can set a hook on `stop'.\n\
7692 This allows you to set a list of commands to be run each time execution\n\
7693 of the program stops."), &cmdlist
);
7695 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
7696 Set inferior debugging."), _("\
7697 Show inferior debugging."), _("\
7698 When non-zero, inferior specific debugging is enabled."),
7701 &setdebuglist
, &showdebuglist
);
7703 add_setshow_boolean_cmd ("displaced", class_maintenance
,
7704 &debug_displaced
, _("\
7705 Set displaced stepping debugging."), _("\
7706 Show displaced stepping debugging."), _("\
7707 When non-zero, displaced stepping specific debugging is enabled."),
7709 show_debug_displaced
,
7710 &setdebuglist
, &showdebuglist
);
7712 add_setshow_boolean_cmd ("non-stop", no_class
,
7714 Set whether gdb controls the inferior in non-stop mode."), _("\
7715 Show whether gdb controls the inferior in non-stop mode."), _("\
7716 When debugging a multi-threaded program and this setting is\n\
7717 off (the default, also called all-stop mode), when one thread stops\n\
7718 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7719 all other threads in the program while you interact with the thread of\n\
7720 interest. When you continue or step a thread, you can allow the other\n\
7721 threads to run, or have them remain stopped, but while you inspect any\n\
7722 thread's state, all threads stop.\n\
7724 In non-stop mode, when one thread stops, other threads can continue\n\
7725 to run freely. You'll be able to step each thread independently,\n\
7726 leave it stopped or free to run as needed."),
7732 numsigs
= (int) GDB_SIGNAL_LAST
;
7733 signal_stop
= (unsigned char *) xmalloc (sizeof (signal_stop
[0]) * numsigs
);
7734 signal_print
= (unsigned char *)
7735 xmalloc (sizeof (signal_print
[0]) * numsigs
);
7736 signal_program
= (unsigned char *)
7737 xmalloc (sizeof (signal_program
[0]) * numsigs
);
7738 signal_catch
= (unsigned char *)
7739 xmalloc (sizeof (signal_catch
[0]) * numsigs
);
7740 signal_pass
= (unsigned char *)
7741 xmalloc (sizeof (signal_pass
[0]) * numsigs
);
7742 for (i
= 0; i
< numsigs
; i
++)
7745 signal_print
[i
] = 1;
7746 signal_program
[i
] = 1;
7747 signal_catch
[i
] = 0;
7750 /* Signals caused by debugger's own actions
7751 should not be given to the program afterwards. */
7752 signal_program
[GDB_SIGNAL_TRAP
] = 0;
7753 signal_program
[GDB_SIGNAL_INT
] = 0;
7755 /* Signals that are not errors should not normally enter the debugger. */
7756 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
7757 signal_print
[GDB_SIGNAL_ALRM
] = 0;
7758 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
7759 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
7760 signal_stop
[GDB_SIGNAL_PROF
] = 0;
7761 signal_print
[GDB_SIGNAL_PROF
] = 0;
7762 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
7763 signal_print
[GDB_SIGNAL_CHLD
] = 0;
7764 signal_stop
[GDB_SIGNAL_IO
] = 0;
7765 signal_print
[GDB_SIGNAL_IO
] = 0;
7766 signal_stop
[GDB_SIGNAL_POLL
] = 0;
7767 signal_print
[GDB_SIGNAL_POLL
] = 0;
7768 signal_stop
[GDB_SIGNAL_URG
] = 0;
7769 signal_print
[GDB_SIGNAL_URG
] = 0;
7770 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
7771 signal_print
[GDB_SIGNAL_WINCH
] = 0;
7772 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
7773 signal_print
[GDB_SIGNAL_PRIO
] = 0;
7775 /* These signals are used internally by user-level thread
7776 implementations. (See signal(5) on Solaris.) Like the above
7777 signals, a healthy program receives and handles them as part of
7778 its normal operation. */
7779 signal_stop
[GDB_SIGNAL_LWP
] = 0;
7780 signal_print
[GDB_SIGNAL_LWP
] = 0;
7781 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
7782 signal_print
[GDB_SIGNAL_WAITING
] = 0;
7783 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
7784 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
7786 /* Update cached state. */
7787 signal_cache_update (-1);
7789 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
7790 &stop_on_solib_events
, _("\
7791 Set stopping for shared library events."), _("\
7792 Show stopping for shared library events."), _("\
7793 If nonzero, gdb will give control to the user when the dynamic linker\n\
7794 notifies gdb of shared library events. The most common event of interest\n\
7795 to the user would be loading/unloading of a new library."),
7796 set_stop_on_solib_events
,
7797 show_stop_on_solib_events
,
7798 &setlist
, &showlist
);
7800 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
7801 follow_fork_mode_kind_names
,
7802 &follow_fork_mode_string
, _("\
7803 Set debugger response to a program call of fork or vfork."), _("\
7804 Show debugger response to a program call of fork or vfork."), _("\
7805 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7806 parent - the original process is debugged after a fork\n\
7807 child - the new process is debugged after a fork\n\
7808 The unfollowed process will continue to run.\n\
7809 By default, the debugger will follow the parent process."),
7811 show_follow_fork_mode_string
,
7812 &setlist
, &showlist
);
7814 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
7815 follow_exec_mode_names
,
7816 &follow_exec_mode_string
, _("\
7817 Set debugger response to a program call of exec."), _("\
7818 Show debugger response to a program call of exec."), _("\
7819 An exec call replaces the program image of a process.\n\
7821 follow-exec-mode can be:\n\
7823 new - the debugger creates a new inferior and rebinds the process\n\
7824 to this new inferior. The program the process was running before\n\
7825 the exec call can be restarted afterwards by restarting the original\n\
7828 same - the debugger keeps the process bound to the same inferior.\n\
7829 The new executable image replaces the previous executable loaded in\n\
7830 the inferior. Restarting the inferior after the exec call restarts\n\
7831 the executable the process was running after the exec call.\n\
7833 By default, the debugger will use the same inferior."),
7835 show_follow_exec_mode_string
,
7836 &setlist
, &showlist
);
7838 add_setshow_enum_cmd ("scheduler-locking", class_run
,
7839 scheduler_enums
, &scheduler_mode
, _("\
7840 Set mode for locking scheduler during execution."), _("\
7841 Show mode for locking scheduler during execution."), _("\
7842 off == no locking (threads may preempt at any time)\n\
7843 on == full locking (no thread except the current thread may run)\n\
7844 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
7845 In this mode, other threads may run during other commands."),
7846 set_schedlock_func
, /* traps on target vector */
7847 show_scheduler_mode
,
7848 &setlist
, &showlist
);
7850 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
7851 Set mode for resuming threads of all processes."), _("\
7852 Show mode for resuming threads of all processes."), _("\
7853 When on, execution commands (such as 'continue' or 'next') resume all\n\
7854 threads of all processes. When off (which is the default), execution\n\
7855 commands only resume the threads of the current process. The set of\n\
7856 threads that are resumed is further refined by the scheduler-locking\n\
7857 mode (see help set scheduler-locking)."),
7859 show_schedule_multiple
,
7860 &setlist
, &showlist
);
7862 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
7863 Set mode of the step operation."), _("\
7864 Show mode of the step operation."), _("\
7865 When set, doing a step over a function without debug line information\n\
7866 will stop at the first instruction of that function. Otherwise, the\n\
7867 function is skipped and the step command stops at a different source line."),
7869 show_step_stop_if_no_debug
,
7870 &setlist
, &showlist
);
7872 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
7873 &can_use_displaced_stepping
, _("\
7874 Set debugger's willingness to use displaced stepping."), _("\
7875 Show debugger's willingness to use displaced stepping."), _("\
7876 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7877 supported by the target architecture. If off, gdb will not use displaced\n\
7878 stepping to step over breakpoints, even if such is supported by the target\n\
7879 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7880 if the target architecture supports it and non-stop mode is active, but will not\n\
7881 use it in all-stop mode (see help set non-stop)."),
7883 show_can_use_displaced_stepping
,
7884 &setlist
, &showlist
);
7886 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
7887 &exec_direction
, _("Set direction of execution.\n\
7888 Options are 'forward' or 'reverse'."),
7889 _("Show direction of execution (forward/reverse)."),
7890 _("Tells gdb whether to execute forward or backward."),
7891 set_exec_direction_func
, show_exec_direction_func
,
7892 &setlist
, &showlist
);
7894 /* Set/show detach-on-fork: user-settable mode. */
7896 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
7897 Set whether gdb will detach the child of a fork."), _("\
7898 Show whether gdb will detach the child of a fork."), _("\
7899 Tells gdb whether to detach the child of a fork."),
7900 NULL
, NULL
, &setlist
, &showlist
);
7902 /* Set/show disable address space randomization mode. */
7904 add_setshow_boolean_cmd ("disable-randomization", class_support
,
7905 &disable_randomization
, _("\
7906 Set disabling of debuggee's virtual address space randomization."), _("\
7907 Show disabling of debuggee's virtual address space randomization."), _("\
7908 When this mode is on (which is the default), randomization of the virtual\n\
7909 address space is disabled. Standalone programs run with the randomization\n\
7910 enabled by default on some platforms."),
7911 &set_disable_randomization
,
7912 &show_disable_randomization
,
7913 &setlist
, &showlist
);
7915 /* ptid initializations */
7916 inferior_ptid
= null_ptid
;
7917 target_last_wait_ptid
= minus_one_ptid
;
7919 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed
);
7920 observer_attach_thread_stop_requested (infrun_thread_stop_requested
);
7921 observer_attach_thread_exit (infrun_thread_thread_exit
);
7922 observer_attach_inferior_exit (infrun_inferior_exit
);
7924 /* Explicitly create without lookup, since that tries to create a
7925 value with a void typed value, and when we get here, gdbarch
7926 isn't initialized yet. At this point, we're quite sure there
7927 isn't another convenience variable of the same name. */
7928 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
7930 add_setshow_boolean_cmd ("observer", no_class
,
7931 &observer_mode_1
, _("\
7932 Set whether gdb controls the inferior in observer mode."), _("\
7933 Show whether gdb controls the inferior in observer mode."), _("\
7934 In observer mode, GDB can get data from the inferior, but not\n\
7935 affect its execution. Registers and memory may not be changed,\n\
7936 breakpoints may not be set, and the program cannot be interrupted\n\