1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2017 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 #include "event-loop.h"
65 #include "thread-fsm.h"
66 #include "common/enum-flags.h"
67 #include "progspace-and-thread.h"
68 #include "common/gdb_optional.h"
69 #include "arch-utils.h"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal
);
75 static void sig_print_header (void);
77 static void resume_cleanups (void *);
79 static int follow_fork (void);
81 static int follow_fork_inferior (int follow_child
, int detach_fork
);
83 static void follow_inferior_reset_breakpoints (void);
85 static int currently_stepping (struct thread_info
*tp
);
87 void nullify_last_target_wait_ptid (void);
89 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
91 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
93 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
95 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
97 /* Asynchronous signal handler registered as event loop source for
98 when we have pending events ready to be passed to the core. */
99 static struct async_event_handler
*infrun_async_inferior_event_token
;
101 /* Stores whether infrun_async was previously enabled or disabled.
102 Starts off as -1, indicating "never enabled/disabled". */
103 static int infrun_is_async
= -1;
108 infrun_async (int enable
)
110 if (infrun_is_async
!= enable
)
112 infrun_is_async
= enable
;
115 fprintf_unfiltered (gdb_stdlog
,
116 "infrun: infrun_async(%d)\n",
120 mark_async_event_handler (infrun_async_inferior_event_token
);
122 clear_async_event_handler (infrun_async_inferior_event_token
);
129 mark_infrun_async_event_handler (void)
131 mark_async_event_handler (infrun_async_inferior_event_token
);
134 /* When set, stop the 'step' command if we enter a function which has
135 no line number information. The normal behavior is that we step
136 over such function. */
137 int step_stop_if_no_debug
= 0;
139 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
140 struct cmd_list_element
*c
, const char *value
)
142 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
145 /* proceed and normal_stop use this to notify the user when the
146 inferior stopped in a different thread than it had been running
149 static ptid_t previous_inferior_ptid
;
151 /* If set (default for legacy reasons), when following a fork, GDB
152 will detach from one of the fork branches, child or parent.
153 Exactly which branch is detached depends on 'set follow-fork-mode'
156 static int detach_fork
= 1;
158 int debug_displaced
= 0;
160 show_debug_displaced (struct ui_file
*file
, int from_tty
,
161 struct cmd_list_element
*c
, const char *value
)
163 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
166 unsigned int debug_infrun
= 0;
168 show_debug_infrun (struct ui_file
*file
, int from_tty
,
169 struct cmd_list_element
*c
, const char *value
)
171 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
175 /* Support for disabling address space randomization. */
177 int disable_randomization
= 1;
180 show_disable_randomization (struct ui_file
*file
, int from_tty
,
181 struct cmd_list_element
*c
, const char *value
)
183 if (target_supports_disable_randomization ())
184 fprintf_filtered (file
,
185 _("Disabling randomization of debuggee's "
186 "virtual address space is %s.\n"),
189 fputs_filtered (_("Disabling randomization of debuggee's "
190 "virtual address space is unsupported on\n"
191 "this platform.\n"), file
);
195 set_disable_randomization (const char *args
, int from_tty
,
196 struct cmd_list_element
*c
)
198 if (!target_supports_disable_randomization ())
199 error (_("Disabling randomization of debuggee's "
200 "virtual address space is unsupported on\n"
204 /* User interface for non-stop mode. */
207 static int non_stop_1
= 0;
210 set_non_stop (const char *args
, int from_tty
,
211 struct cmd_list_element
*c
)
213 if (target_has_execution
)
215 non_stop_1
= non_stop
;
216 error (_("Cannot change this setting while the inferior is running."));
219 non_stop
= non_stop_1
;
223 show_non_stop (struct ui_file
*file
, int from_tty
,
224 struct cmd_list_element
*c
, const char *value
)
226 fprintf_filtered (file
,
227 _("Controlling the inferior in non-stop mode is %s.\n"),
231 /* "Observer mode" is somewhat like a more extreme version of
232 non-stop, in which all GDB operations that might affect the
233 target's execution have been disabled. */
235 int observer_mode
= 0;
236 static int observer_mode_1
= 0;
239 set_observer_mode (const char *args
, int from_tty
,
240 struct cmd_list_element
*c
)
242 if (target_has_execution
)
244 observer_mode_1
= observer_mode
;
245 error (_("Cannot change this setting while the inferior is running."));
248 observer_mode
= observer_mode_1
;
250 may_write_registers
= !observer_mode
;
251 may_write_memory
= !observer_mode
;
252 may_insert_breakpoints
= !observer_mode
;
253 may_insert_tracepoints
= !observer_mode
;
254 /* We can insert fast tracepoints in or out of observer mode,
255 but enable them if we're going into this mode. */
257 may_insert_fast_tracepoints
= 1;
258 may_stop
= !observer_mode
;
259 update_target_permissions ();
261 /* Going *into* observer mode we must force non-stop, then
262 going out we leave it that way. */
265 pagination_enabled
= 0;
266 non_stop
= non_stop_1
= 1;
270 printf_filtered (_("Observer mode is now %s.\n"),
271 (observer_mode
? "on" : "off"));
275 show_observer_mode (struct ui_file
*file
, int from_tty
,
276 struct cmd_list_element
*c
, const char *value
)
278 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
281 /* This updates the value of observer mode based on changes in
282 permissions. Note that we are deliberately ignoring the values of
283 may-write-registers and may-write-memory, since the user may have
284 reason to enable these during a session, for instance to turn on a
285 debugging-related global. */
288 update_observer_mode (void)
292 newval
= (!may_insert_breakpoints
293 && !may_insert_tracepoints
294 && may_insert_fast_tracepoints
298 /* Let the user know if things change. */
299 if (newval
!= observer_mode
)
300 printf_filtered (_("Observer mode is now %s.\n"),
301 (newval
? "on" : "off"));
303 observer_mode
= observer_mode_1
= newval
;
306 /* Tables of how to react to signals; the user sets them. */
308 static unsigned char *signal_stop
;
309 static unsigned char *signal_print
;
310 static unsigned char *signal_program
;
312 /* Table of signals that are registered with "catch signal". A
313 non-zero entry indicates that the signal is caught by some "catch
314 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
316 static unsigned char *signal_catch
;
318 /* Table of signals that the target may silently handle.
319 This is automatically determined from the flags above,
320 and simply cached here. */
321 static unsigned char *signal_pass
;
323 #define SET_SIGS(nsigs,sigs,flags) \
325 int signum = (nsigs); \
326 while (signum-- > 0) \
327 if ((sigs)[signum]) \
328 (flags)[signum] = 1; \
331 #define UNSET_SIGS(nsigs,sigs,flags) \
333 int signum = (nsigs); \
334 while (signum-- > 0) \
335 if ((sigs)[signum]) \
336 (flags)[signum] = 0; \
339 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
340 this function is to avoid exporting `signal_program'. */
343 update_signals_program_target (void)
345 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
348 /* Value to pass to target_resume() to cause all threads to resume. */
350 #define RESUME_ALL minus_one_ptid
352 /* Command list pointer for the "stop" placeholder. */
354 static struct cmd_list_element
*stop_command
;
356 /* Nonzero if we want to give control to the user when we're notified
357 of shared library events by the dynamic linker. */
358 int stop_on_solib_events
;
360 /* Enable or disable optional shared library event breakpoints
361 as appropriate when the above flag is changed. */
364 set_stop_on_solib_events (const char *args
,
365 int from_tty
, struct cmd_list_element
*c
)
367 update_solib_breakpoints ();
371 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
372 struct cmd_list_element
*c
, const char *value
)
374 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
378 /* Nonzero after stop if current stack frame should be printed. */
380 static int stop_print_frame
;
382 /* This is a cached copy of the pid/waitstatus of the last event
383 returned by target_wait()/deprecated_target_wait_hook(). This
384 information is returned by get_last_target_status(). */
385 static ptid_t target_last_wait_ptid
;
386 static struct target_waitstatus target_last_waitstatus
;
388 static void context_switch (ptid_t ptid
);
390 void init_thread_stepping_state (struct thread_info
*tss
);
392 static const char follow_fork_mode_child
[] = "child";
393 static const char follow_fork_mode_parent
[] = "parent";
395 static const char *const follow_fork_mode_kind_names
[] = {
396 follow_fork_mode_child
,
397 follow_fork_mode_parent
,
401 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
403 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
404 struct cmd_list_element
*c
, const char *value
)
406 fprintf_filtered (file
,
407 _("Debugger response to a program "
408 "call of fork or vfork is \"%s\".\n"),
413 /* Handle changes to the inferior list based on the type of fork,
414 which process is being followed, and whether the other process
415 should be detached. On entry inferior_ptid must be the ptid of
416 the fork parent. At return inferior_ptid is the ptid of the
417 followed inferior. */
420 follow_fork_inferior (int follow_child
, int detach_fork
)
423 ptid_t parent_ptid
, child_ptid
;
425 has_vforked
= (inferior_thread ()->pending_follow
.kind
426 == TARGET_WAITKIND_VFORKED
);
427 parent_ptid
= inferior_ptid
;
428 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
431 && !non_stop
/* Non-stop always resumes both branches. */
432 && current_ui
->prompt_state
== PROMPT_BLOCKED
433 && !(follow_child
|| detach_fork
|| sched_multi
))
435 /* The parent stays blocked inside the vfork syscall until the
436 child execs or exits. If we don't let the child run, then
437 the parent stays blocked. If we're telling the parent to run
438 in the foreground, the user will not be able to ctrl-c to get
439 back the terminal, effectively hanging the debug session. */
440 fprintf_filtered (gdb_stderr
, _("\
441 Can not resume the parent process over vfork in the foreground while\n\
442 holding the child stopped. Try \"set detach-on-fork\" or \
443 \"set schedule-multiple\".\n"));
444 /* FIXME output string > 80 columns. */
450 /* Detach new forked process? */
453 /* Before detaching from the child, remove all breakpoints
454 from it. If we forked, then this has already been taken
455 care of by infrun.c. If we vforked however, any
456 breakpoint inserted in the parent is visible in the
457 child, even those added while stopped in a vfork
458 catchpoint. This will remove the breakpoints from the
459 parent also, but they'll be reinserted below. */
462 /* Keep breakpoints list in sync. */
463 remove_breakpoints_pid (ptid_get_pid (inferior_ptid
));
466 if (info_verbose
|| debug_infrun
)
468 /* Ensure that we have a process ptid. */
469 ptid_t process_ptid
= pid_to_ptid (ptid_get_pid (child_ptid
));
471 target_terminal::ours_for_output ();
472 fprintf_filtered (gdb_stdlog
,
473 _("Detaching after %s from child %s.\n"),
474 has_vforked
? "vfork" : "fork",
475 target_pid_to_str (process_ptid
));
480 struct inferior
*parent_inf
, *child_inf
;
482 /* Add process to GDB's tables. */
483 child_inf
= add_inferior (ptid_get_pid (child_ptid
));
485 parent_inf
= current_inferior ();
486 child_inf
->attach_flag
= parent_inf
->attach_flag
;
487 copy_terminal_info (child_inf
, parent_inf
);
488 child_inf
->gdbarch
= parent_inf
->gdbarch
;
489 copy_inferior_target_desc_info (child_inf
, parent_inf
);
491 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
493 inferior_ptid
= child_ptid
;
494 add_thread (inferior_ptid
);
495 set_current_inferior (child_inf
);
496 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
498 /* If this is a vfork child, then the address-space is
499 shared with the parent. */
502 child_inf
->pspace
= parent_inf
->pspace
;
503 child_inf
->aspace
= parent_inf
->aspace
;
505 /* The parent will be frozen until the child is done
506 with the shared region. Keep track of the
508 child_inf
->vfork_parent
= parent_inf
;
509 child_inf
->pending_detach
= 0;
510 parent_inf
->vfork_child
= child_inf
;
511 parent_inf
->pending_detach
= 0;
515 child_inf
->aspace
= new_address_space ();
516 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
517 child_inf
->removable
= 1;
518 set_current_program_space (child_inf
->pspace
);
519 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
521 /* Let the shared library layer (e.g., solib-svr4) learn
522 about this new process, relocate the cloned exec, pull
523 in shared libraries, and install the solib event
524 breakpoint. If a "cloned-VM" event was propagated
525 better throughout the core, this wouldn't be
527 solib_create_inferior_hook (0);
533 struct inferior
*parent_inf
;
535 parent_inf
= current_inferior ();
537 /* If we detached from the child, then we have to be careful
538 to not insert breakpoints in the parent until the child
539 is done with the shared memory region. However, if we're
540 staying attached to the child, then we can and should
541 insert breakpoints, so that we can debug it. A
542 subsequent child exec or exit is enough to know when does
543 the child stops using the parent's address space. */
544 parent_inf
->waiting_for_vfork_done
= detach_fork
;
545 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
550 /* Follow the child. */
551 struct inferior
*parent_inf
, *child_inf
;
552 struct program_space
*parent_pspace
;
554 if (info_verbose
|| debug_infrun
)
556 target_terminal::ours_for_output ();
557 fprintf_filtered (gdb_stdlog
,
558 _("Attaching after %s %s to child %s.\n"),
559 target_pid_to_str (parent_ptid
),
560 has_vforked
? "vfork" : "fork",
561 target_pid_to_str (child_ptid
));
564 /* Add the new inferior first, so that the target_detach below
565 doesn't unpush the target. */
567 child_inf
= add_inferior (ptid_get_pid (child_ptid
));
569 parent_inf
= current_inferior ();
570 child_inf
->attach_flag
= parent_inf
->attach_flag
;
571 copy_terminal_info (child_inf
, parent_inf
);
572 child_inf
->gdbarch
= parent_inf
->gdbarch
;
573 copy_inferior_target_desc_info (child_inf
, parent_inf
);
575 parent_pspace
= parent_inf
->pspace
;
577 /* If we're vforking, we want to hold on to the parent until the
578 child exits or execs. At child exec or exit time we can
579 remove the old breakpoints from the parent and detach or
580 resume debugging it. Otherwise, detach the parent now; we'll
581 want to reuse it's program/address spaces, but we can't set
582 them to the child before removing breakpoints from the
583 parent, otherwise, the breakpoints module could decide to
584 remove breakpoints from the wrong process (since they'd be
585 assigned to the same address space). */
589 gdb_assert (child_inf
->vfork_parent
== NULL
);
590 gdb_assert (parent_inf
->vfork_child
== NULL
);
591 child_inf
->vfork_parent
= parent_inf
;
592 child_inf
->pending_detach
= 0;
593 parent_inf
->vfork_child
= child_inf
;
594 parent_inf
->pending_detach
= detach_fork
;
595 parent_inf
->waiting_for_vfork_done
= 0;
597 else if (detach_fork
)
599 if (info_verbose
|| debug_infrun
)
601 /* Ensure that we have a process ptid. */
602 ptid_t process_ptid
= pid_to_ptid (ptid_get_pid (child_ptid
));
604 target_terminal::ours_for_output ();
605 fprintf_filtered (gdb_stdlog
,
606 _("Detaching after fork from "
608 target_pid_to_str (process_ptid
));
611 target_detach (NULL
, 0);
614 /* Note that the detach above makes PARENT_INF dangling. */
616 /* Add the child thread to the appropriate lists, and switch to
617 this new thread, before cloning the program space, and
618 informing the solib layer about this new process. */
620 inferior_ptid
= child_ptid
;
621 add_thread (inferior_ptid
);
622 set_current_inferior (child_inf
);
624 /* If this is a vfork child, then the address-space is shared
625 with the parent. If we detached from the parent, then we can
626 reuse the parent's program/address spaces. */
627 if (has_vforked
|| detach_fork
)
629 child_inf
->pspace
= parent_pspace
;
630 child_inf
->aspace
= child_inf
->pspace
->aspace
;
634 child_inf
->aspace
= new_address_space ();
635 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
636 child_inf
->removable
= 1;
637 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
638 set_current_program_space (child_inf
->pspace
);
639 clone_program_space (child_inf
->pspace
, parent_pspace
);
641 /* Let the shared library layer (e.g., solib-svr4) learn
642 about this new process, relocate the cloned exec, pull in
643 shared libraries, and install the solib event breakpoint.
644 If a "cloned-VM" event was propagated better throughout
645 the core, this wouldn't be required. */
646 solib_create_inferior_hook (0);
650 return target_follow_fork (follow_child
, detach_fork
);
653 /* Tell the target to follow the fork we're stopped at. Returns true
654 if the inferior should be resumed; false, if the target for some
655 reason decided it's best not to resume. */
660 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
661 int should_resume
= 1;
662 struct thread_info
*tp
;
664 /* Copy user stepping state to the new inferior thread. FIXME: the
665 followed fork child thread should have a copy of most of the
666 parent thread structure's run control related fields, not just these.
667 Initialized to avoid "may be used uninitialized" warnings from gcc. */
668 struct breakpoint
*step_resume_breakpoint
= NULL
;
669 struct breakpoint
*exception_resume_breakpoint
= NULL
;
670 CORE_ADDR step_range_start
= 0;
671 CORE_ADDR step_range_end
= 0;
672 struct frame_id step_frame_id
= { 0 };
673 struct thread_fsm
*thread_fsm
= NULL
;
678 struct target_waitstatus wait_status
;
680 /* Get the last target status returned by target_wait(). */
681 get_last_target_status (&wait_ptid
, &wait_status
);
683 /* If not stopped at a fork event, then there's nothing else to
685 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
686 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
689 /* Check if we switched over from WAIT_PTID, since the event was
691 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
692 && !ptid_equal (inferior_ptid
, wait_ptid
))
694 /* We did. Switch back to WAIT_PTID thread, to tell the
695 target to follow it (in either direction). We'll
696 afterwards refuse to resume, and inform the user what
698 switch_to_thread (wait_ptid
);
703 tp
= inferior_thread ();
705 /* If there were any forks/vforks that were caught and are now to be
706 followed, then do so now. */
707 switch (tp
->pending_follow
.kind
)
709 case TARGET_WAITKIND_FORKED
:
710 case TARGET_WAITKIND_VFORKED
:
712 ptid_t parent
, child
;
714 /* If the user did a next/step, etc, over a fork call,
715 preserve the stepping state in the fork child. */
716 if (follow_child
&& should_resume
)
718 step_resume_breakpoint
= clone_momentary_breakpoint
719 (tp
->control
.step_resume_breakpoint
);
720 step_range_start
= tp
->control
.step_range_start
;
721 step_range_end
= tp
->control
.step_range_end
;
722 step_frame_id
= tp
->control
.step_frame_id
;
723 exception_resume_breakpoint
724 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
725 thread_fsm
= tp
->thread_fsm
;
727 /* For now, delete the parent's sr breakpoint, otherwise,
728 parent/child sr breakpoints are considered duplicates,
729 and the child version will not be installed. Remove
730 this when the breakpoints module becomes aware of
731 inferiors and address spaces. */
732 delete_step_resume_breakpoint (tp
);
733 tp
->control
.step_range_start
= 0;
734 tp
->control
.step_range_end
= 0;
735 tp
->control
.step_frame_id
= null_frame_id
;
736 delete_exception_resume_breakpoint (tp
);
737 tp
->thread_fsm
= NULL
;
740 parent
= inferior_ptid
;
741 child
= tp
->pending_follow
.value
.related_pid
;
743 /* Set up inferior(s) as specified by the caller, and tell the
744 target to do whatever is necessary to follow either parent
746 if (follow_fork_inferior (follow_child
, detach_fork
))
748 /* Target refused to follow, or there's some other reason
749 we shouldn't resume. */
754 /* This pending follow fork event is now handled, one way
755 or another. The previous selected thread may be gone
756 from the lists by now, but if it is still around, need
757 to clear the pending follow request. */
758 tp
= find_thread_ptid (parent
);
760 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
762 /* This makes sure we don't try to apply the "Switched
763 over from WAIT_PID" logic above. */
764 nullify_last_target_wait_ptid ();
766 /* If we followed the child, switch to it... */
769 switch_to_thread (child
);
771 /* ... and preserve the stepping state, in case the
772 user was stepping over the fork call. */
775 tp
= inferior_thread ();
776 tp
->control
.step_resume_breakpoint
777 = step_resume_breakpoint
;
778 tp
->control
.step_range_start
= step_range_start
;
779 tp
->control
.step_range_end
= step_range_end
;
780 tp
->control
.step_frame_id
= step_frame_id
;
781 tp
->control
.exception_resume_breakpoint
782 = exception_resume_breakpoint
;
783 tp
->thread_fsm
= thread_fsm
;
787 /* If we get here, it was because we're trying to
788 resume from a fork catchpoint, but, the user
789 has switched threads away from the thread that
790 forked. In that case, the resume command
791 issued is most likely not applicable to the
792 child, so just warn, and refuse to resume. */
793 warning (_("Not resuming: switched threads "
794 "before following fork child."));
797 /* Reset breakpoints in the child as appropriate. */
798 follow_inferior_reset_breakpoints ();
801 switch_to_thread (parent
);
805 case TARGET_WAITKIND_SPURIOUS
:
806 /* Nothing to follow. */
809 internal_error (__FILE__
, __LINE__
,
810 "Unexpected pending_follow.kind %d\n",
811 tp
->pending_follow
.kind
);
815 return should_resume
;
819 follow_inferior_reset_breakpoints (void)
821 struct thread_info
*tp
= inferior_thread ();
823 /* Was there a step_resume breakpoint? (There was if the user
824 did a "next" at the fork() call.) If so, explicitly reset its
825 thread number. Cloned step_resume breakpoints are disabled on
826 creation, so enable it here now that it is associated with the
829 step_resumes are a form of bp that are made to be per-thread.
830 Since we created the step_resume bp when the parent process
831 was being debugged, and now are switching to the child process,
832 from the breakpoint package's viewpoint, that's a switch of
833 "threads". We must update the bp's notion of which thread
834 it is for, or it'll be ignored when it triggers. */
836 if (tp
->control
.step_resume_breakpoint
)
838 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
839 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
842 /* Treat exception_resume breakpoints like step_resume breakpoints. */
843 if (tp
->control
.exception_resume_breakpoint
)
845 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
846 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
849 /* Reinsert all breakpoints in the child. The user may have set
850 breakpoints after catching the fork, in which case those
851 were never set in the child, but only in the parent. This makes
852 sure the inserted breakpoints match the breakpoint list. */
854 breakpoint_re_set ();
855 insert_breakpoints ();
858 /* The child has exited or execed: resume threads of the parent the
859 user wanted to be executing. */
862 proceed_after_vfork_done (struct thread_info
*thread
,
865 int pid
= * (int *) arg
;
867 if (ptid_get_pid (thread
->ptid
) == pid
868 && is_running (thread
->ptid
)
869 && !is_executing (thread
->ptid
)
870 && !thread
->stop_requested
871 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
874 fprintf_unfiltered (gdb_stdlog
,
875 "infrun: resuming vfork parent thread %s\n",
876 target_pid_to_str (thread
->ptid
));
878 switch_to_thread (thread
->ptid
);
879 clear_proceed_status (0);
880 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
886 /* Save/restore inferior_ptid, current program space and current
887 inferior. Only use this if the current context points at an exited
888 inferior (and therefore there's no current thread to save). */
889 class scoped_restore_exited_inferior
892 scoped_restore_exited_inferior ()
893 : m_saved_ptid (&inferior_ptid
)
897 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
898 scoped_restore_current_program_space m_pspace
;
899 scoped_restore_current_inferior m_inferior
;
902 /* Called whenever we notice an exec or exit event, to handle
903 detaching or resuming a vfork parent. */
906 handle_vfork_child_exec_or_exit (int exec
)
908 struct inferior
*inf
= current_inferior ();
910 if (inf
->vfork_parent
)
912 int resume_parent
= -1;
914 /* This exec or exit marks the end of the shared memory region
915 between the parent and the child. If the user wanted to
916 detach from the parent, now is the time. */
918 if (inf
->vfork_parent
->pending_detach
)
920 struct thread_info
*tp
;
921 struct program_space
*pspace
;
922 struct address_space
*aspace
;
924 /* follow-fork child, detach-on-fork on. */
926 inf
->vfork_parent
->pending_detach
= 0;
928 gdb::optional
<scoped_restore_exited_inferior
>
929 maybe_restore_inferior
;
930 gdb::optional
<scoped_restore_current_pspace_and_thread
>
931 maybe_restore_thread
;
933 /* If we're handling a child exit, then inferior_ptid points
934 at the inferior's pid, not to a thread. */
936 maybe_restore_inferior
.emplace ();
938 maybe_restore_thread
.emplace ();
940 /* We're letting loose of the parent. */
941 tp
= any_live_thread_of_process (inf
->vfork_parent
->pid
);
942 switch_to_thread (tp
->ptid
);
944 /* We're about to detach from the parent, which implicitly
945 removes breakpoints from its address space. There's a
946 catch here: we want to reuse the spaces for the child,
947 but, parent/child are still sharing the pspace at this
948 point, although the exec in reality makes the kernel give
949 the child a fresh set of new pages. The problem here is
950 that the breakpoints module being unaware of this, would
951 likely chose the child process to write to the parent
952 address space. Swapping the child temporarily away from
953 the spaces has the desired effect. Yes, this is "sort
956 pspace
= inf
->pspace
;
957 aspace
= inf
->aspace
;
961 if (debug_infrun
|| info_verbose
)
963 target_terminal::ours_for_output ();
967 fprintf_filtered (gdb_stdlog
,
968 _("Detaching vfork parent process "
969 "%d after child exec.\n"),
970 inf
->vfork_parent
->pid
);
974 fprintf_filtered (gdb_stdlog
,
975 _("Detaching vfork parent process "
976 "%d after child exit.\n"),
977 inf
->vfork_parent
->pid
);
981 target_detach (NULL
, 0);
984 inf
->pspace
= pspace
;
985 inf
->aspace
= aspace
;
989 /* We're staying attached to the parent, so, really give the
990 child a new address space. */
991 inf
->pspace
= add_program_space (maybe_new_address_space ());
992 inf
->aspace
= inf
->pspace
->aspace
;
994 set_current_program_space (inf
->pspace
);
996 resume_parent
= inf
->vfork_parent
->pid
;
998 /* Break the bonds. */
999 inf
->vfork_parent
->vfork_child
= NULL
;
1003 struct program_space
*pspace
;
1005 /* If this is a vfork child exiting, then the pspace and
1006 aspaces were shared with the parent. Since we're
1007 reporting the process exit, we'll be mourning all that is
1008 found in the address space, and switching to null_ptid,
1009 preparing to start a new inferior. But, since we don't
1010 want to clobber the parent's address/program spaces, we
1011 go ahead and create a new one for this exiting
1014 /* Switch to null_ptid while running clone_program_space, so
1015 that clone_program_space doesn't want to read the
1016 selected frame of a dead process. */
1017 scoped_restore restore_ptid
1018 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1020 /* This inferior is dead, so avoid giving the breakpoints
1021 module the option to write through to it (cloning a
1022 program space resets breakpoints). */
1025 pspace
= add_program_space (maybe_new_address_space ());
1026 set_current_program_space (pspace
);
1028 inf
->symfile_flags
= SYMFILE_NO_READ
;
1029 clone_program_space (pspace
, inf
->vfork_parent
->pspace
);
1030 inf
->pspace
= pspace
;
1031 inf
->aspace
= pspace
->aspace
;
1033 resume_parent
= inf
->vfork_parent
->pid
;
1034 /* Break the bonds. */
1035 inf
->vfork_parent
->vfork_child
= NULL
;
1038 inf
->vfork_parent
= NULL
;
1040 gdb_assert (current_program_space
== inf
->pspace
);
1042 if (non_stop
&& resume_parent
!= -1)
1044 /* If the user wanted the parent to be running, let it go
1046 scoped_restore_current_thread restore_thread
;
1049 fprintf_unfiltered (gdb_stdlog
,
1050 "infrun: resuming vfork parent process %d\n",
1053 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1058 /* Enum strings for "set|show follow-exec-mode". */
1060 static const char follow_exec_mode_new
[] = "new";
1061 static const char follow_exec_mode_same
[] = "same";
1062 static const char *const follow_exec_mode_names
[] =
1064 follow_exec_mode_new
,
1065 follow_exec_mode_same
,
1069 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1071 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1072 struct cmd_list_element
*c
, const char *value
)
1074 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1077 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1080 follow_exec (ptid_t ptid
, char *exec_file_target
)
1082 struct thread_info
*th
, *tmp
;
1083 struct inferior
*inf
= current_inferior ();
1084 int pid
= ptid_get_pid (ptid
);
1085 ptid_t process_ptid
;
1086 char *exec_file_host
;
1087 struct cleanup
*old_chain
;
1089 /* This is an exec event that we actually wish to pay attention to.
1090 Refresh our symbol table to the newly exec'd program, remove any
1091 momentary bp's, etc.
1093 If there are breakpoints, they aren't really inserted now,
1094 since the exec() transformed our inferior into a fresh set
1097 We want to preserve symbolic breakpoints on the list, since
1098 we have hopes that they can be reset after the new a.out's
1099 symbol table is read.
1101 However, any "raw" breakpoints must be removed from the list
1102 (e.g., the solib bp's), since their address is probably invalid
1105 And, we DON'T want to call delete_breakpoints() here, since
1106 that may write the bp's "shadow contents" (the instruction
1107 value that was overwritten witha TRAP instruction). Since
1108 we now have a new a.out, those shadow contents aren't valid. */
1110 mark_breakpoints_out ();
1112 /* The target reports the exec event to the main thread, even if
1113 some other thread does the exec, and even if the main thread was
1114 stopped or already gone. We may still have non-leader threads of
1115 the process on our list. E.g., on targets that don't have thread
1116 exit events (like remote); or on native Linux in non-stop mode if
1117 there were only two threads in the inferior and the non-leader
1118 one is the one that execs (and nothing forces an update of the
1119 thread list up to here). When debugging remotely, it's best to
1120 avoid extra traffic, when possible, so avoid syncing the thread
1121 list with the target, and instead go ahead and delete all threads
1122 of the process but one that reported the event. Note this must
1123 be done before calling update_breakpoints_after_exec, as
1124 otherwise clearing the threads' resources would reference stale
1125 thread breakpoints -- it may have been one of these threads that
1126 stepped across the exec. We could just clear their stepping
1127 states, but as long as we're iterating, might as well delete
1128 them. Deleting them now rather than at the next user-visible
1129 stop provides a nicer sequence of events for user and MI
1131 ALL_THREADS_SAFE (th
, tmp
)
1132 if (ptid_get_pid (th
->ptid
) == pid
&& !ptid_equal (th
->ptid
, ptid
))
1133 delete_thread (th
->ptid
);
1135 /* We also need to clear any left over stale state for the
1136 leader/event thread. E.g., if there was any step-resume
1137 breakpoint or similar, it's gone now. We cannot truly
1138 step-to-next statement through an exec(). */
1139 th
= inferior_thread ();
1140 th
->control
.step_resume_breakpoint
= NULL
;
1141 th
->control
.exception_resume_breakpoint
= NULL
;
1142 th
->control
.single_step_breakpoints
= NULL
;
1143 th
->control
.step_range_start
= 0;
1144 th
->control
.step_range_end
= 0;
1146 /* The user may have had the main thread held stopped in the
1147 previous image (e.g., schedlock on, or non-stop). Release
1149 th
->stop_requested
= 0;
1151 update_breakpoints_after_exec ();
1153 /* What is this a.out's name? */
1154 process_ptid
= pid_to_ptid (pid
);
1155 printf_unfiltered (_("%s is executing new program: %s\n"),
1156 target_pid_to_str (process_ptid
),
1159 /* We've followed the inferior through an exec. Therefore, the
1160 inferior has essentially been killed & reborn. */
1162 gdb_flush (gdb_stdout
);
1164 breakpoint_init_inferior (inf_execd
);
1166 exec_file_host
= exec_file_find (exec_file_target
, NULL
);
1167 old_chain
= make_cleanup (xfree
, exec_file_host
);
1169 /* If we were unable to map the executable target pathname onto a host
1170 pathname, tell the user that. Otherwise GDB's subsequent behavior
1171 is confusing. Maybe it would even be better to stop at this point
1172 so that the user can specify a file manually before continuing. */
1173 if (exec_file_host
== NULL
)
1174 warning (_("Could not load symbols for executable %s.\n"
1175 "Do you need \"set sysroot\"?"),
1178 /* Reset the shared library package. This ensures that we get a
1179 shlib event when the child reaches "_start", at which point the
1180 dld will have had a chance to initialize the child. */
1181 /* Also, loading a symbol file below may trigger symbol lookups, and
1182 we don't want those to be satisfied by the libraries of the
1183 previous incarnation of this process. */
1184 no_shared_libraries (NULL
, 0);
1186 if (follow_exec_mode_string
== follow_exec_mode_new
)
1188 /* The user wants to keep the old inferior and program spaces
1189 around. Create a new fresh one, and switch to it. */
1191 /* Do exit processing for the original inferior before adding
1192 the new inferior so we don't have two active inferiors with
1193 the same ptid, which can confuse find_inferior_ptid. */
1194 exit_inferior_num_silent (current_inferior ()->num
);
1196 inf
= add_inferior_with_spaces ();
1198 target_follow_exec (inf
, exec_file_target
);
1200 set_current_inferior (inf
);
1201 set_current_program_space (inf
->pspace
);
1205 /* The old description may no longer be fit for the new image.
1206 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1207 old description; we'll read a new one below. No need to do
1208 this on "follow-exec-mode new", as the old inferior stays
1209 around (its description is later cleared/refetched on
1211 target_clear_description ();
1214 gdb_assert (current_program_space
== inf
->pspace
);
1216 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1217 because the proper displacement for a PIE (Position Independent
1218 Executable) main symbol file will only be computed by
1219 solib_create_inferior_hook below. breakpoint_re_set would fail
1220 to insert the breakpoints with the zero displacement. */
1221 try_open_exec_file (exec_file_host
, inf
, SYMFILE_DEFER_BP_RESET
);
1223 do_cleanups (old_chain
);
1225 /* If the target can specify a description, read it. Must do this
1226 after flipping to the new executable (because the target supplied
1227 description must be compatible with the executable's
1228 architecture, and the old executable may e.g., be 32-bit, while
1229 the new one 64-bit), and before anything involving memory or
1231 target_find_description ();
1233 /* The add_thread call ends up reading registers, so do it after updating the
1234 target description. */
1235 if (follow_exec_mode_string
== follow_exec_mode_new
)
1238 solib_create_inferior_hook (0);
1240 jit_inferior_created_hook ();
1242 breakpoint_re_set ();
1244 /* Reinsert all breakpoints. (Those which were symbolic have
1245 been reset to the proper address in the new a.out, thanks
1246 to symbol_file_command...). */
1247 insert_breakpoints ();
1249 /* The next resume of this inferior should bring it to the shlib
1250 startup breakpoints. (If the user had also set bp's on
1251 "main" from the old (parent) process, then they'll auto-
1252 matically get reset there in the new process.). */
1255 /* The queue of threads that need to do a step-over operation to get
1256 past e.g., a breakpoint. What technique is used to step over the
1257 breakpoint/watchpoint does not matter -- all threads end up in the
1258 same queue, to maintain rough temporal order of execution, in order
1259 to avoid starvation, otherwise, we could e.g., find ourselves
1260 constantly stepping the same couple threads past their breakpoints
1261 over and over, if the single-step finish fast enough. */
1262 struct thread_info
*step_over_queue_head
;
1264 /* Bit flags indicating what the thread needs to step over. */
1266 enum step_over_what_flag
1268 /* Step over a breakpoint. */
1269 STEP_OVER_BREAKPOINT
= 1,
1271 /* Step past a non-continuable watchpoint, in order to let the
1272 instruction execute so we can evaluate the watchpoint
1274 STEP_OVER_WATCHPOINT
= 2
1276 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1278 /* Info about an instruction that is being stepped over. */
1280 struct step_over_info
1282 /* If we're stepping past a breakpoint, this is the address space
1283 and address of the instruction the breakpoint is set at. We'll
1284 skip inserting all breakpoints here. Valid iff ASPACE is
1286 const address_space
*aspace
;
1289 /* The instruction being stepped over triggers a nonsteppable
1290 watchpoint. If true, we'll skip inserting watchpoints. */
1291 int nonsteppable_watchpoint_p
;
1293 /* The thread's global number. */
1297 /* The step-over info of the location that is being stepped over.
1299 Note that with async/breakpoint always-inserted mode, a user might
1300 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1301 being stepped over. As setting a new breakpoint inserts all
1302 breakpoints, we need to make sure the breakpoint being stepped over
1303 isn't inserted then. We do that by only clearing the step-over
1304 info when the step-over is actually finished (or aborted).
1306 Presently GDB can only step over one breakpoint at any given time.
1307 Given threads that can't run code in the same address space as the
1308 breakpoint's can't really miss the breakpoint, GDB could be taught
1309 to step-over at most one breakpoint per address space (so this info
1310 could move to the address space object if/when GDB is extended).
1311 The set of breakpoints being stepped over will normally be much
1312 smaller than the set of all breakpoints, so a flag in the
1313 breakpoint location structure would be wasteful. A separate list
1314 also saves complexity and run-time, as otherwise we'd have to go
1315 through all breakpoint locations clearing their flag whenever we
1316 start a new sequence. Similar considerations weigh against storing
1317 this info in the thread object. Plus, not all step overs actually
1318 have breakpoint locations -- e.g., stepping past a single-step
1319 breakpoint, or stepping to complete a non-continuable
1321 static struct step_over_info step_over_info
;
1323 /* Record the address of the breakpoint/instruction we're currently
1325 N.B. We record the aspace and address now, instead of say just the thread,
1326 because when we need the info later the thread may be running. */
1329 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1330 int nonsteppable_watchpoint_p
,
1333 step_over_info
.aspace
= aspace
;
1334 step_over_info
.address
= address
;
1335 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1336 step_over_info
.thread
= thread
;
1339 /* Called when we're not longer stepping over a breakpoint / an
1340 instruction, so all breakpoints are free to be (re)inserted. */
1343 clear_step_over_info (void)
1346 fprintf_unfiltered (gdb_stdlog
,
1347 "infrun: clear_step_over_info\n");
1348 step_over_info
.aspace
= NULL
;
1349 step_over_info
.address
= 0;
1350 step_over_info
.nonsteppable_watchpoint_p
= 0;
1351 step_over_info
.thread
= -1;
1357 stepping_past_instruction_at (struct address_space
*aspace
,
1360 return (step_over_info
.aspace
!= NULL
1361 && breakpoint_address_match (aspace
, address
,
1362 step_over_info
.aspace
,
1363 step_over_info
.address
));
1369 thread_is_stepping_over_breakpoint (int thread
)
1371 return (step_over_info
.thread
!= -1
1372 && thread
== step_over_info
.thread
);
1378 stepping_past_nonsteppable_watchpoint (void)
1380 return step_over_info
.nonsteppable_watchpoint_p
;
1383 /* Returns true if step-over info is valid. */
1386 step_over_info_valid_p (void)
1388 return (step_over_info
.aspace
!= NULL
1389 || stepping_past_nonsteppable_watchpoint ());
1393 /* Displaced stepping. */
1395 /* In non-stop debugging mode, we must take special care to manage
1396 breakpoints properly; in particular, the traditional strategy for
1397 stepping a thread past a breakpoint it has hit is unsuitable.
1398 'Displaced stepping' is a tactic for stepping one thread past a
1399 breakpoint it has hit while ensuring that other threads running
1400 concurrently will hit the breakpoint as they should.
1402 The traditional way to step a thread T off a breakpoint in a
1403 multi-threaded program in all-stop mode is as follows:
1405 a0) Initially, all threads are stopped, and breakpoints are not
1407 a1) We single-step T, leaving breakpoints uninserted.
1408 a2) We insert breakpoints, and resume all threads.
1410 In non-stop debugging, however, this strategy is unsuitable: we
1411 don't want to have to stop all threads in the system in order to
1412 continue or step T past a breakpoint. Instead, we use displaced
1415 n0) Initially, T is stopped, other threads are running, and
1416 breakpoints are inserted.
1417 n1) We copy the instruction "under" the breakpoint to a separate
1418 location, outside the main code stream, making any adjustments
1419 to the instruction, register, and memory state as directed by
1421 n2) We single-step T over the instruction at its new location.
1422 n3) We adjust the resulting register and memory state as directed
1423 by T's architecture. This includes resetting T's PC to point
1424 back into the main instruction stream.
1427 This approach depends on the following gdbarch methods:
1429 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1430 indicate where to copy the instruction, and how much space must
1431 be reserved there. We use these in step n1.
1433 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1434 address, and makes any necessary adjustments to the instruction,
1435 register contents, and memory. We use this in step n1.
1437 - gdbarch_displaced_step_fixup adjusts registers and memory after
1438 we have successfuly single-stepped the instruction, to yield the
1439 same effect the instruction would have had if we had executed it
1440 at its original address. We use this in step n3.
1442 The gdbarch_displaced_step_copy_insn and
1443 gdbarch_displaced_step_fixup functions must be written so that
1444 copying an instruction with gdbarch_displaced_step_copy_insn,
1445 single-stepping across the copied instruction, and then applying
1446 gdbarch_displaced_insn_fixup should have the same effects on the
1447 thread's memory and registers as stepping the instruction in place
1448 would have. Exactly which responsibilities fall to the copy and
1449 which fall to the fixup is up to the author of those functions.
1451 See the comments in gdbarch.sh for details.
1453 Note that displaced stepping and software single-step cannot
1454 currently be used in combination, although with some care I think
1455 they could be made to. Software single-step works by placing
1456 breakpoints on all possible subsequent instructions; if the
1457 displaced instruction is a PC-relative jump, those breakpoints
1458 could fall in very strange places --- on pages that aren't
1459 executable, or at addresses that are not proper instruction
1460 boundaries. (We do generally let other threads run while we wait
1461 to hit the software single-step breakpoint, and they might
1462 encounter such a corrupted instruction.) One way to work around
1463 this would be to have gdbarch_displaced_step_copy_insn fully
1464 simulate the effect of PC-relative instructions (and return NULL)
1465 on architectures that use software single-stepping.
1467 In non-stop mode, we can have independent and simultaneous step
1468 requests, so more than one thread may need to simultaneously step
1469 over a breakpoint. The current implementation assumes there is
1470 only one scratch space per process. In this case, we have to
1471 serialize access to the scratch space. If thread A wants to step
1472 over a breakpoint, but we are currently waiting for some other
1473 thread to complete a displaced step, we leave thread A stopped and
1474 place it in the displaced_step_request_queue. Whenever a displaced
1475 step finishes, we pick the next thread in the queue and start a new
1476 displaced step operation on it. See displaced_step_prepare and
1477 displaced_step_fixup for details. */
1479 /* Default destructor for displaced_step_closure. */
1481 displaced_step_closure::~displaced_step_closure () = default;
1483 /* Per-inferior displaced stepping state. */
1484 struct displaced_step_inferior_state
1486 /* Pointer to next in linked list. */
1487 struct displaced_step_inferior_state
*next
;
1489 /* The process this displaced step state refers to. */
1492 /* True if preparing a displaced step ever failed. If so, we won't
1493 try displaced stepping for this inferior again. */
1496 /* If this is not null_ptid, this is the thread carrying out a
1497 displaced single-step in process PID. This thread's state will
1498 require fixing up once it has completed its step. */
1501 /* The architecture the thread had when we stepped it. */
1502 struct gdbarch
*step_gdbarch
;
1504 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1505 for post-step cleanup. */
1506 struct displaced_step_closure
*step_closure
;
1508 /* The address of the original instruction, and the copy we
1510 CORE_ADDR step_original
, step_copy
;
1512 /* Saved contents of copy area. */
1513 gdb_byte
*step_saved_copy
;
1516 /* The list of states of processes involved in displaced stepping
1518 static struct displaced_step_inferior_state
*displaced_step_inferior_states
;
1520 /* Get the displaced stepping state of process PID. */
1522 static struct displaced_step_inferior_state
*
1523 get_displaced_stepping_state (int pid
)
1525 struct displaced_step_inferior_state
*state
;
1527 for (state
= displaced_step_inferior_states
;
1529 state
= state
->next
)
1530 if (state
->pid
== pid
)
1536 /* Returns true if any inferior has a thread doing a displaced
1540 displaced_step_in_progress_any_inferior (void)
1542 struct displaced_step_inferior_state
*state
;
1544 for (state
= displaced_step_inferior_states
;
1546 state
= state
->next
)
1547 if (!ptid_equal (state
->step_ptid
, null_ptid
))
1553 /* Return true if thread represented by PTID is doing a displaced
1557 displaced_step_in_progress_thread (ptid_t ptid
)
1559 struct displaced_step_inferior_state
*displaced
;
1561 gdb_assert (!ptid_equal (ptid
, null_ptid
));
1563 displaced
= get_displaced_stepping_state (ptid_get_pid (ptid
));
1565 return (displaced
!= NULL
&& ptid_equal (displaced
->step_ptid
, ptid
));
1568 /* Return true if process PID has a thread doing a displaced step. */
1571 displaced_step_in_progress (int pid
)
1573 struct displaced_step_inferior_state
*displaced
;
1575 displaced
= get_displaced_stepping_state (pid
);
1576 if (displaced
!= NULL
&& !ptid_equal (displaced
->step_ptid
, null_ptid
))
1582 /* Add a new displaced stepping state for process PID to the displaced
1583 stepping state list, or return a pointer to an already existing
1584 entry, if it already exists. Never returns NULL. */
1586 static struct displaced_step_inferior_state
*
1587 add_displaced_stepping_state (int pid
)
1589 struct displaced_step_inferior_state
*state
;
1591 for (state
= displaced_step_inferior_states
;
1593 state
= state
->next
)
1594 if (state
->pid
== pid
)
1597 state
= XCNEW (struct displaced_step_inferior_state
);
1599 state
->next
= displaced_step_inferior_states
;
1600 displaced_step_inferior_states
= state
;
1605 /* If inferior is in displaced stepping, and ADDR equals to starting address
1606 of copy area, return corresponding displaced_step_closure. Otherwise,
1609 struct displaced_step_closure
*
1610 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1612 struct displaced_step_inferior_state
*displaced
1613 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
1615 /* If checking the mode of displaced instruction in copy area. */
1616 if (displaced
&& !ptid_equal (displaced
->step_ptid
, null_ptid
)
1617 && (displaced
->step_copy
== addr
))
1618 return displaced
->step_closure
;
1623 /* Remove the displaced stepping state of process PID. */
1626 remove_displaced_stepping_state (int pid
)
1628 struct displaced_step_inferior_state
*it
, **prev_next_p
;
1630 gdb_assert (pid
!= 0);
1632 it
= displaced_step_inferior_states
;
1633 prev_next_p
= &displaced_step_inferior_states
;
1638 *prev_next_p
= it
->next
;
1643 prev_next_p
= &it
->next
;
1649 infrun_inferior_exit (struct inferior
*inf
)
1651 remove_displaced_stepping_state (inf
->pid
);
1654 /* If ON, and the architecture supports it, GDB will use displaced
1655 stepping to step over breakpoints. If OFF, or if the architecture
1656 doesn't support it, GDB will instead use the traditional
1657 hold-and-step approach. If AUTO (which is the default), GDB will
1658 decide which technique to use to step over breakpoints depending on
1659 which of all-stop or non-stop mode is active --- displaced stepping
1660 in non-stop mode; hold-and-step in all-stop mode. */
1662 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1665 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1666 struct cmd_list_element
*c
,
1669 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1670 fprintf_filtered (file
,
1671 _("Debugger's willingness to use displaced stepping "
1672 "to step over breakpoints is %s (currently %s).\n"),
1673 value
, target_is_non_stop_p () ? "on" : "off");
1675 fprintf_filtered (file
,
1676 _("Debugger's willingness to use displaced stepping "
1677 "to step over breakpoints is %s.\n"), value
);
1680 /* Return non-zero if displaced stepping can/should be used to step
1681 over breakpoints of thread TP. */
1684 use_displaced_stepping (struct thread_info
*tp
)
1686 struct regcache
*regcache
= get_thread_regcache (tp
->ptid
);
1687 struct gdbarch
*gdbarch
= regcache
->arch ();
1688 struct displaced_step_inferior_state
*displaced_state
;
1690 displaced_state
= get_displaced_stepping_state (ptid_get_pid (tp
->ptid
));
1692 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1693 && target_is_non_stop_p ())
1694 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1695 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1696 && find_record_target () == NULL
1697 && (displaced_state
== NULL
1698 || !displaced_state
->failed_before
));
1701 /* Clean out any stray displaced stepping state. */
1703 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1705 /* Indicate that there is no cleanup pending. */
1706 displaced
->step_ptid
= null_ptid
;
1708 delete displaced
->step_closure
;
1709 displaced
->step_closure
= NULL
;
1713 displaced_step_clear_cleanup (void *arg
)
1715 struct displaced_step_inferior_state
*state
1716 = (struct displaced_step_inferior_state
*) arg
;
1718 displaced_step_clear (state
);
1721 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1723 displaced_step_dump_bytes (struct ui_file
*file
,
1724 const gdb_byte
*buf
,
1729 for (i
= 0; i
< len
; i
++)
1730 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1731 fputs_unfiltered ("\n", file
);
1734 /* Prepare to single-step, using displaced stepping.
1736 Note that we cannot use displaced stepping when we have a signal to
1737 deliver. If we have a signal to deliver and an instruction to step
1738 over, then after the step, there will be no indication from the
1739 target whether the thread entered a signal handler or ignored the
1740 signal and stepped over the instruction successfully --- both cases
1741 result in a simple SIGTRAP. In the first case we mustn't do a
1742 fixup, and in the second case we must --- but we can't tell which.
1743 Comments in the code for 'random signals' in handle_inferior_event
1744 explain how we handle this case instead.
1746 Returns 1 if preparing was successful -- this thread is going to be
1747 stepped now; 0 if displaced stepping this thread got queued; or -1
1748 if this instruction can't be displaced stepped. */
1751 displaced_step_prepare_throw (ptid_t ptid
)
1753 struct cleanup
*ignore_cleanups
;
1754 struct thread_info
*tp
= find_thread_ptid (ptid
);
1755 struct regcache
*regcache
= get_thread_regcache (ptid
);
1756 struct gdbarch
*gdbarch
= regcache
->arch ();
1757 const address_space
*aspace
= regcache
->aspace ();
1758 CORE_ADDR original
, copy
;
1760 struct displaced_step_closure
*closure
;
1761 struct displaced_step_inferior_state
*displaced
;
1764 /* We should never reach this function if the architecture does not
1765 support displaced stepping. */
1766 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1768 /* Nor if the thread isn't meant to step over a breakpoint. */
1769 gdb_assert (tp
->control
.trap_expected
);
1771 /* Disable range stepping while executing in the scratch pad. We
1772 want a single-step even if executing the displaced instruction in
1773 the scratch buffer lands within the stepping range (e.g., a
1775 tp
->control
.may_range_step
= 0;
1777 /* We have to displaced step one thread at a time, as we only have
1778 access to a single scratch space per inferior. */
1780 displaced
= add_displaced_stepping_state (ptid_get_pid (ptid
));
1782 if (!ptid_equal (displaced
->step_ptid
, null_ptid
))
1784 /* Already waiting for a displaced step to finish. Defer this
1785 request and place in queue. */
1787 if (debug_displaced
)
1788 fprintf_unfiltered (gdb_stdlog
,
1789 "displaced: deferring step of %s\n",
1790 target_pid_to_str (ptid
));
1792 thread_step_over_chain_enqueue (tp
);
1797 if (debug_displaced
)
1798 fprintf_unfiltered (gdb_stdlog
,
1799 "displaced: stepping %s now\n",
1800 target_pid_to_str (ptid
));
1803 displaced_step_clear (displaced
);
1805 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1806 inferior_ptid
= ptid
;
1808 original
= regcache_read_pc (regcache
);
1810 copy
= gdbarch_displaced_step_location (gdbarch
);
1811 len
= gdbarch_max_insn_length (gdbarch
);
1813 if (breakpoint_in_range_p (aspace
, copy
, len
))
1815 /* There's a breakpoint set in the scratch pad location range
1816 (which is usually around the entry point). We'd either
1817 install it before resuming, which would overwrite/corrupt the
1818 scratch pad, or if it was already inserted, this displaced
1819 step would overwrite it. The latter is OK in the sense that
1820 we already assume that no thread is going to execute the code
1821 in the scratch pad range (after initial startup) anyway, but
1822 the former is unacceptable. Simply punt and fallback to
1823 stepping over this breakpoint in-line. */
1824 if (debug_displaced
)
1826 fprintf_unfiltered (gdb_stdlog
,
1827 "displaced: breakpoint set in scratch pad. "
1828 "Stepping over breakpoint in-line instead.\n");
1834 /* Save the original contents of the copy area. */
1835 displaced
->step_saved_copy
= (gdb_byte
*) xmalloc (len
);
1836 ignore_cleanups
= make_cleanup (free_current_contents
,
1837 &displaced
->step_saved_copy
);
1838 status
= target_read_memory (copy
, displaced
->step_saved_copy
, len
);
1840 throw_error (MEMORY_ERROR
,
1841 _("Error accessing memory address %s (%s) for "
1842 "displaced-stepping scratch space."),
1843 paddress (gdbarch
, copy
), safe_strerror (status
));
1844 if (debug_displaced
)
1846 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1847 paddress (gdbarch
, copy
));
1848 displaced_step_dump_bytes (gdb_stdlog
,
1849 displaced
->step_saved_copy
,
1853 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1854 original
, copy
, regcache
);
1855 if (closure
== NULL
)
1857 /* The architecture doesn't know how or want to displaced step
1858 this instruction or instruction sequence. Fallback to
1859 stepping over the breakpoint in-line. */
1860 do_cleanups (ignore_cleanups
);
1864 /* Save the information we need to fix things up if the step
1866 displaced
->step_ptid
= ptid
;
1867 displaced
->step_gdbarch
= gdbarch
;
1868 displaced
->step_closure
= closure
;
1869 displaced
->step_original
= original
;
1870 displaced
->step_copy
= copy
;
1872 make_cleanup (displaced_step_clear_cleanup
, displaced
);
1874 /* Resume execution at the copy. */
1875 regcache_write_pc (regcache
, copy
);
1877 discard_cleanups (ignore_cleanups
);
1879 if (debug_displaced
)
1880 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1881 paddress (gdbarch
, copy
));
1886 /* Wrapper for displaced_step_prepare_throw that disabled further
1887 attempts at displaced stepping if we get a memory error. */
1890 displaced_step_prepare (ptid_t ptid
)
1896 prepared
= displaced_step_prepare_throw (ptid
);
1898 CATCH (ex
, RETURN_MASK_ERROR
)
1900 struct displaced_step_inferior_state
*displaced_state
;
1902 if (ex
.error
!= MEMORY_ERROR
1903 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1904 throw_exception (ex
);
1908 fprintf_unfiltered (gdb_stdlog
,
1909 "infrun: disabling displaced stepping: %s\n",
1913 /* Be verbose if "set displaced-stepping" is "on", silent if
1915 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1917 warning (_("disabling displaced stepping: %s"),
1921 /* Disable further displaced stepping attempts. */
1923 = get_displaced_stepping_state (ptid_get_pid (ptid
));
1924 displaced_state
->failed_before
= 1;
1932 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1933 const gdb_byte
*myaddr
, int len
)
1935 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1937 inferior_ptid
= ptid
;
1938 write_memory (memaddr
, myaddr
, len
);
1941 /* Restore the contents of the copy area for thread PTID. */
1944 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1947 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1949 write_memory_ptid (ptid
, displaced
->step_copy
,
1950 displaced
->step_saved_copy
, len
);
1951 if (debug_displaced
)
1952 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1953 target_pid_to_str (ptid
),
1954 paddress (displaced
->step_gdbarch
,
1955 displaced
->step_copy
));
1958 /* If we displaced stepped an instruction successfully, adjust
1959 registers and memory to yield the same effect the instruction would
1960 have had if we had executed it at its original address, and return
1961 1. If the instruction didn't complete, relocate the PC and return
1962 -1. If the thread wasn't displaced stepping, return 0. */
1965 displaced_step_fixup (ptid_t event_ptid
, enum gdb_signal signal
)
1967 struct cleanup
*old_cleanups
;
1968 struct displaced_step_inferior_state
*displaced
1969 = get_displaced_stepping_state (ptid_get_pid (event_ptid
));
1972 /* Was any thread of this process doing a displaced step? */
1973 if (displaced
== NULL
)
1976 /* Was this event for the pid we displaced? */
1977 if (ptid_equal (displaced
->step_ptid
, null_ptid
)
1978 || ! ptid_equal (displaced
->step_ptid
, event_ptid
))
1981 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, displaced
);
1983 displaced_step_restore (displaced
, displaced
->step_ptid
);
1985 /* Fixup may need to read memory/registers. Switch to the thread
1986 that we're fixing up. Also, target_stopped_by_watchpoint checks
1987 the current thread. */
1988 switch_to_thread (event_ptid
);
1990 /* Did the instruction complete successfully? */
1991 if (signal
== GDB_SIGNAL_TRAP
1992 && !(target_stopped_by_watchpoint ()
1993 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1994 || target_have_steppable_watchpoint
)))
1996 /* Fix up the resulting state. */
1997 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1998 displaced
->step_closure
,
1999 displaced
->step_original
,
2000 displaced
->step_copy
,
2001 get_thread_regcache (displaced
->step_ptid
));
2006 /* Since the instruction didn't complete, all we can do is
2008 struct regcache
*regcache
= get_thread_regcache (event_ptid
);
2009 CORE_ADDR pc
= regcache_read_pc (regcache
);
2011 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
2012 regcache_write_pc (regcache
, pc
);
2016 do_cleanups (old_cleanups
);
2018 displaced
->step_ptid
= null_ptid
;
2023 /* Data to be passed around while handling an event. This data is
2024 discarded between events. */
2025 struct execution_control_state
2028 /* The thread that got the event, if this was a thread event; NULL
2030 struct thread_info
*event_thread
;
2032 struct target_waitstatus ws
;
2033 int stop_func_filled_in
;
2034 CORE_ADDR stop_func_start
;
2035 CORE_ADDR stop_func_end
;
2036 const char *stop_func_name
;
2039 /* True if the event thread hit the single-step breakpoint of
2040 another thread. Thus the event doesn't cause a stop, the thread
2041 needs to be single-stepped past the single-step breakpoint before
2042 we can switch back to the original stepping thread. */
2043 int hit_singlestep_breakpoint
;
2046 /* Clear ECS and set it to point at TP. */
2049 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
2051 memset (ecs
, 0, sizeof (*ecs
));
2052 ecs
->event_thread
= tp
;
2053 ecs
->ptid
= tp
->ptid
;
2056 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
2057 static void prepare_to_wait (struct execution_control_state
*ecs
);
2058 static int keep_going_stepped_thread (struct thread_info
*tp
);
2059 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
2061 /* Are there any pending step-over requests? If so, run all we can
2062 now and return true. Otherwise, return false. */
2065 start_step_over (void)
2067 struct thread_info
*tp
, *next
;
2069 /* Don't start a new step-over if we already have an in-line
2070 step-over operation ongoing. */
2071 if (step_over_info_valid_p ())
2074 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
2076 struct execution_control_state ecss
;
2077 struct execution_control_state
*ecs
= &ecss
;
2078 step_over_what step_what
;
2079 int must_be_in_line
;
2081 gdb_assert (!tp
->stop_requested
);
2083 next
= thread_step_over_chain_next (tp
);
2085 /* If this inferior already has a displaced step in process,
2086 don't start a new one. */
2087 if (displaced_step_in_progress (ptid_get_pid (tp
->ptid
)))
2090 step_what
= thread_still_needs_step_over (tp
);
2091 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
2092 || ((step_what
& STEP_OVER_BREAKPOINT
)
2093 && !use_displaced_stepping (tp
)));
2095 /* We currently stop all threads of all processes to step-over
2096 in-line. If we need to start a new in-line step-over, let
2097 any pending displaced steps finish first. */
2098 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
2101 thread_step_over_chain_remove (tp
);
2103 if (step_over_queue_head
== NULL
)
2106 fprintf_unfiltered (gdb_stdlog
,
2107 "infrun: step-over queue now empty\n");
2110 if (tp
->control
.trap_expected
2114 internal_error (__FILE__
, __LINE__
,
2115 "[%s] has inconsistent state: "
2116 "trap_expected=%d, resumed=%d, executing=%d\n",
2117 target_pid_to_str (tp
->ptid
),
2118 tp
->control
.trap_expected
,
2124 fprintf_unfiltered (gdb_stdlog
,
2125 "infrun: resuming [%s] for step-over\n",
2126 target_pid_to_str (tp
->ptid
));
2128 /* keep_going_pass_signal skips the step-over if the breakpoint
2129 is no longer inserted. In all-stop, we want to keep looking
2130 for a thread that needs a step-over instead of resuming TP,
2131 because we wouldn't be able to resume anything else until the
2132 target stops again. In non-stop, the resume always resumes
2133 only TP, so it's OK to let the thread resume freely. */
2134 if (!target_is_non_stop_p () && !step_what
)
2137 switch_to_thread (tp
->ptid
);
2138 reset_ecs (ecs
, tp
);
2139 keep_going_pass_signal (ecs
);
2141 if (!ecs
->wait_some_more
)
2142 error (_("Command aborted."));
2144 gdb_assert (tp
->resumed
);
2146 /* If we started a new in-line step-over, we're done. */
2147 if (step_over_info_valid_p ())
2149 gdb_assert (tp
->control
.trap_expected
);
2153 if (!target_is_non_stop_p ())
2155 /* On all-stop, shouldn't have resumed unless we needed a
2157 gdb_assert (tp
->control
.trap_expected
2158 || tp
->step_after_step_resume_breakpoint
);
2160 /* With remote targets (at least), in all-stop, we can't
2161 issue any further remote commands until the program stops
2166 /* Either the thread no longer needed a step-over, or a new
2167 displaced stepping sequence started. Even in the latter
2168 case, continue looking. Maybe we can also start another
2169 displaced step on a thread of other process. */
2175 /* Update global variables holding ptids to hold NEW_PTID if they were
2176 holding OLD_PTID. */
2178 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2180 struct displaced_step_inferior_state
*displaced
;
2182 if (ptid_equal (inferior_ptid
, old_ptid
))
2183 inferior_ptid
= new_ptid
;
2185 for (displaced
= displaced_step_inferior_states
;
2187 displaced
= displaced
->next
)
2189 if (ptid_equal (displaced
->step_ptid
, old_ptid
))
2190 displaced
->step_ptid
= new_ptid
;
2197 /* Things to clean up if we QUIT out of resume (). */
2199 resume_cleanups (void *ignore
)
2201 if (!ptid_equal (inferior_ptid
, null_ptid
))
2202 delete_single_step_breakpoints (inferior_thread ());
2207 static const char schedlock_off
[] = "off";
2208 static const char schedlock_on
[] = "on";
2209 static const char schedlock_step
[] = "step";
2210 static const char schedlock_replay
[] = "replay";
2211 static const char *const scheduler_enums
[] = {
2218 static const char *scheduler_mode
= schedlock_replay
;
2220 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2221 struct cmd_list_element
*c
, const char *value
)
2223 fprintf_filtered (file
,
2224 _("Mode for locking scheduler "
2225 "during execution is \"%s\".\n"),
2230 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2232 if (!target_can_lock_scheduler
)
2234 scheduler_mode
= schedlock_off
;
2235 error (_("Target '%s' cannot support this command."), target_shortname
);
2239 /* True if execution commands resume all threads of all processes by
2240 default; otherwise, resume only threads of the current inferior
2242 int sched_multi
= 0;
2244 /* Try to setup for software single stepping over the specified location.
2245 Return 1 if target_resume() should use hardware single step.
2247 GDBARCH the current gdbarch.
2248 PC the location to step over. */
2251 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2255 if (execution_direction
== EXEC_FORWARD
2256 && gdbarch_software_single_step_p (gdbarch
))
2257 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2265 user_visible_resume_ptid (int step
)
2271 /* With non-stop mode on, threads are always handled
2273 resume_ptid
= inferior_ptid
;
2275 else if ((scheduler_mode
== schedlock_on
)
2276 || (scheduler_mode
== schedlock_step
&& step
))
2278 /* User-settable 'scheduler' mode requires solo thread
2280 resume_ptid
= inferior_ptid
;
2282 else if ((scheduler_mode
== schedlock_replay
)
2283 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2285 /* User-settable 'scheduler' mode requires solo thread resume in replay
2287 resume_ptid
= inferior_ptid
;
2289 else if (!sched_multi
&& target_supports_multi_process ())
2291 /* Resume all threads of the current process (and none of other
2293 resume_ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
2297 /* Resume all threads of all processes. */
2298 resume_ptid
= RESUME_ALL
;
2304 /* Return a ptid representing the set of threads that we will resume,
2305 in the perspective of the target, assuming run control handling
2306 does not require leaving some threads stopped (e.g., stepping past
2307 breakpoint). USER_STEP indicates whether we're about to start the
2308 target for a stepping command. */
2311 internal_resume_ptid (int user_step
)
2313 /* In non-stop, we always control threads individually. Note that
2314 the target may always work in non-stop mode even with "set
2315 non-stop off", in which case user_visible_resume_ptid could
2316 return a wildcard ptid. */
2317 if (target_is_non_stop_p ())
2318 return inferior_ptid
;
2320 return user_visible_resume_ptid (user_step
);
2323 /* Wrapper for target_resume, that handles infrun-specific
2327 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2329 struct thread_info
*tp
= inferior_thread ();
2331 gdb_assert (!tp
->stop_requested
);
2333 /* Install inferior's terminal modes. */
2334 target_terminal::inferior ();
2336 /* Avoid confusing the next resume, if the next stop/resume
2337 happens to apply to another thread. */
2338 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2340 /* Advise target which signals may be handled silently.
2342 If we have removed breakpoints because we are stepping over one
2343 in-line (in any thread), we need to receive all signals to avoid
2344 accidentally skipping a breakpoint during execution of a signal
2347 Likewise if we're displaced stepping, otherwise a trap for a
2348 breakpoint in a signal handler might be confused with the
2349 displaced step finishing. We don't make the displaced_step_fixup
2350 step distinguish the cases instead, because:
2352 - a backtrace while stopped in the signal handler would show the
2353 scratch pad as frame older than the signal handler, instead of
2354 the real mainline code.
2356 - when the thread is later resumed, the signal handler would
2357 return to the scratch pad area, which would no longer be
2359 if (step_over_info_valid_p ()
2360 || displaced_step_in_progress (ptid_get_pid (tp
->ptid
)))
2361 target_pass_signals (0, NULL
);
2363 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
2365 target_resume (resume_ptid
, step
, sig
);
2367 target_commit_resume ();
2370 /* Resume the inferior, but allow a QUIT. This is useful if the user
2371 wants to interrupt some lengthy single-stepping operation
2372 (for child processes, the SIGINT goes to the inferior, and so
2373 we get a SIGINT random_signal, but for remote debugging and perhaps
2374 other targets, that's not true).
2376 SIG is the signal to give the inferior (zero for none). */
2378 resume (enum gdb_signal sig
)
2380 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
2381 struct regcache
*regcache
= get_current_regcache ();
2382 struct gdbarch
*gdbarch
= regcache
->arch ();
2383 struct thread_info
*tp
= inferior_thread ();
2384 CORE_ADDR pc
= regcache_read_pc (regcache
);
2385 const address_space
*aspace
= regcache
->aspace ();
2387 /* This represents the user's step vs continue request. When
2388 deciding whether "set scheduler-locking step" applies, it's the
2389 user's intention that counts. */
2390 const int user_step
= tp
->control
.stepping_command
;
2391 /* This represents what we'll actually request the target to do.
2392 This can decay from a step to a continue, if e.g., we need to
2393 implement single-stepping with breakpoints (software
2397 gdb_assert (!tp
->stop_requested
);
2398 gdb_assert (!thread_is_in_step_over_chain (tp
));
2402 if (tp
->suspend
.waitstatus_pending_p
)
2407 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2409 fprintf_unfiltered (gdb_stdlog
,
2410 "infrun: resume: thread %s has pending wait "
2411 "status %s (currently_stepping=%d).\n",
2412 target_pid_to_str (tp
->ptid
), statstr
.c_str (),
2413 currently_stepping (tp
));
2418 /* FIXME: What should we do if we are supposed to resume this
2419 thread with a signal? Maybe we should maintain a queue of
2420 pending signals to deliver. */
2421 if (sig
!= GDB_SIGNAL_0
)
2423 warning (_("Couldn't deliver signal %s to %s."),
2424 gdb_signal_to_name (sig
), target_pid_to_str (tp
->ptid
));
2427 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2428 discard_cleanups (old_cleanups
);
2430 if (target_can_async_p ())
2435 tp
->stepped_breakpoint
= 0;
2437 /* Depends on stepped_breakpoint. */
2438 step
= currently_stepping (tp
);
2440 if (current_inferior ()->waiting_for_vfork_done
)
2442 /* Don't try to single-step a vfork parent that is waiting for
2443 the child to get out of the shared memory region (by exec'ing
2444 or exiting). This is particularly important on software
2445 single-step archs, as the child process would trip on the
2446 software single step breakpoint inserted for the parent
2447 process. Since the parent will not actually execute any
2448 instruction until the child is out of the shared region (such
2449 are vfork's semantics), it is safe to simply continue it.
2450 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2451 the parent, and tell it to `keep_going', which automatically
2452 re-sets it stepping. */
2454 fprintf_unfiltered (gdb_stdlog
,
2455 "infrun: resume : clear step\n");
2460 fprintf_unfiltered (gdb_stdlog
,
2461 "infrun: resume (step=%d, signal=%s), "
2462 "trap_expected=%d, current thread [%s] at %s\n",
2463 step
, gdb_signal_to_symbol_string (sig
),
2464 tp
->control
.trap_expected
,
2465 target_pid_to_str (inferior_ptid
),
2466 paddress (gdbarch
, pc
));
2468 /* Normally, by the time we reach `resume', the breakpoints are either
2469 removed or inserted, as appropriate. The exception is if we're sitting
2470 at a permanent breakpoint; we need to step over it, but permanent
2471 breakpoints can't be removed. So we have to test for it here. */
2472 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2474 if (sig
!= GDB_SIGNAL_0
)
2476 /* We have a signal to pass to the inferior. The resume
2477 may, or may not take us to the signal handler. If this
2478 is a step, we'll need to stop in the signal handler, if
2479 there's one, (if the target supports stepping into
2480 handlers), or in the next mainline instruction, if
2481 there's no handler. If this is a continue, we need to be
2482 sure to run the handler with all breakpoints inserted.
2483 In all cases, set a breakpoint at the current address
2484 (where the handler returns to), and once that breakpoint
2485 is hit, resume skipping the permanent breakpoint. If
2486 that breakpoint isn't hit, then we've stepped into the
2487 signal handler (or hit some other event). We'll delete
2488 the step-resume breakpoint then. */
2491 fprintf_unfiltered (gdb_stdlog
,
2492 "infrun: resume: skipping permanent breakpoint, "
2493 "deliver signal first\n");
2495 clear_step_over_info ();
2496 tp
->control
.trap_expected
= 0;
2498 if (tp
->control
.step_resume_breakpoint
== NULL
)
2500 /* Set a "high-priority" step-resume, as we don't want
2501 user breakpoints at PC to trigger (again) when this
2503 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2504 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2506 tp
->step_after_step_resume_breakpoint
= step
;
2509 insert_breakpoints ();
2513 /* There's no signal to pass, we can go ahead and skip the
2514 permanent breakpoint manually. */
2516 fprintf_unfiltered (gdb_stdlog
,
2517 "infrun: resume: skipping permanent breakpoint\n");
2518 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2519 /* Update pc to reflect the new address from which we will
2520 execute instructions. */
2521 pc
= regcache_read_pc (regcache
);
2525 /* We've already advanced the PC, so the stepping part
2526 is done. Now we need to arrange for a trap to be
2527 reported to handle_inferior_event. Set a breakpoint
2528 at the current PC, and run to it. Don't update
2529 prev_pc, because if we end in
2530 switch_back_to_stepped_thread, we want the "expected
2531 thread advanced also" branch to be taken. IOW, we
2532 don't want this thread to step further from PC
2534 gdb_assert (!step_over_info_valid_p ());
2535 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2536 insert_breakpoints ();
2538 resume_ptid
= internal_resume_ptid (user_step
);
2539 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2540 discard_cleanups (old_cleanups
);
2547 /* If we have a breakpoint to step over, make sure to do a single
2548 step only. Same if we have software watchpoints. */
2549 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2550 tp
->control
.may_range_step
= 0;
2552 /* If enabled, step over breakpoints by executing a copy of the
2553 instruction at a different address.
2555 We can't use displaced stepping when we have a signal to deliver;
2556 the comments for displaced_step_prepare explain why. The
2557 comments in the handle_inferior event for dealing with 'random
2558 signals' explain what we do instead.
2560 We can't use displaced stepping when we are waiting for vfork_done
2561 event, displaced stepping breaks the vfork child similarly as single
2562 step software breakpoint. */
2563 if (tp
->control
.trap_expected
2564 && use_displaced_stepping (tp
)
2565 && !step_over_info_valid_p ()
2566 && sig
== GDB_SIGNAL_0
2567 && !current_inferior ()->waiting_for_vfork_done
)
2569 int prepared
= displaced_step_prepare (inferior_ptid
);
2574 fprintf_unfiltered (gdb_stdlog
,
2575 "Got placed in step-over queue\n");
2577 tp
->control
.trap_expected
= 0;
2578 discard_cleanups (old_cleanups
);
2581 else if (prepared
< 0)
2583 /* Fallback to stepping over the breakpoint in-line. */
2585 if (target_is_non_stop_p ())
2586 stop_all_threads ();
2588 set_step_over_info (regcache
->aspace (),
2589 regcache_read_pc (regcache
), 0, tp
->global_num
);
2591 step
= maybe_software_singlestep (gdbarch
, pc
);
2593 insert_breakpoints ();
2595 else if (prepared
> 0)
2597 struct displaced_step_inferior_state
*displaced
;
2599 /* Update pc to reflect the new address from which we will
2600 execute instructions due to displaced stepping. */
2601 pc
= regcache_read_pc (get_thread_regcache (inferior_ptid
));
2603 displaced
= get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
2604 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2605 displaced
->step_closure
);
2609 /* Do we need to do it the hard way, w/temp breakpoints? */
2611 step
= maybe_software_singlestep (gdbarch
, pc
);
2613 /* Currently, our software single-step implementation leads to different
2614 results than hardware single-stepping in one situation: when stepping
2615 into delivering a signal which has an associated signal handler,
2616 hardware single-step will stop at the first instruction of the handler,
2617 while software single-step will simply skip execution of the handler.
2619 For now, this difference in behavior is accepted since there is no
2620 easy way to actually implement single-stepping into a signal handler
2621 without kernel support.
2623 However, there is one scenario where this difference leads to follow-on
2624 problems: if we're stepping off a breakpoint by removing all breakpoints
2625 and then single-stepping. In this case, the software single-step
2626 behavior means that even if there is a *breakpoint* in the signal
2627 handler, GDB still would not stop.
2629 Fortunately, we can at least fix this particular issue. We detect
2630 here the case where we are about to deliver a signal while software
2631 single-stepping with breakpoints removed. In this situation, we
2632 revert the decisions to remove all breakpoints and insert single-
2633 step breakpoints, and instead we install a step-resume breakpoint
2634 at the current address, deliver the signal without stepping, and
2635 once we arrive back at the step-resume breakpoint, actually step
2636 over the breakpoint we originally wanted to step over. */
2637 if (thread_has_single_step_breakpoints_set (tp
)
2638 && sig
!= GDB_SIGNAL_0
2639 && step_over_info_valid_p ())
2641 /* If we have nested signals or a pending signal is delivered
2642 immediately after a handler returns, might might already have
2643 a step-resume breakpoint set on the earlier handler. We cannot
2644 set another step-resume breakpoint; just continue on until the
2645 original breakpoint is hit. */
2646 if (tp
->control
.step_resume_breakpoint
== NULL
)
2648 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2649 tp
->step_after_step_resume_breakpoint
= 1;
2652 delete_single_step_breakpoints (tp
);
2654 clear_step_over_info ();
2655 tp
->control
.trap_expected
= 0;
2657 insert_breakpoints ();
2660 /* If STEP is set, it's a request to use hardware stepping
2661 facilities. But in that case, we should never
2662 use singlestep breakpoint. */
2663 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2665 /* Decide the set of threads to ask the target to resume. */
2666 if (tp
->control
.trap_expected
)
2668 /* We're allowing a thread to run past a breakpoint it has
2669 hit, either by single-stepping the thread with the breakpoint
2670 removed, or by displaced stepping, with the breakpoint inserted.
2671 In the former case, we need to single-step only this thread,
2672 and keep others stopped, as they can miss this breakpoint if
2673 allowed to run. That's not really a problem for displaced
2674 stepping, but, we still keep other threads stopped, in case
2675 another thread is also stopped for a breakpoint waiting for
2676 its turn in the displaced stepping queue. */
2677 resume_ptid
= inferior_ptid
;
2680 resume_ptid
= internal_resume_ptid (user_step
);
2682 if (execution_direction
!= EXEC_REVERSE
2683 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2685 /* There are two cases where we currently need to step a
2686 breakpoint instruction when we have a signal to deliver:
2688 - See handle_signal_stop where we handle random signals that
2689 could take out us out of the stepping range. Normally, in
2690 that case we end up continuing (instead of stepping) over the
2691 signal handler with a breakpoint at PC, but there are cases
2692 where we should _always_ single-step, even if we have a
2693 step-resume breakpoint, like when a software watchpoint is
2694 set. Assuming single-stepping and delivering a signal at the
2695 same time would takes us to the signal handler, then we could
2696 have removed the breakpoint at PC to step over it. However,
2697 some hardware step targets (like e.g., Mac OS) can't step
2698 into signal handlers, and for those, we need to leave the
2699 breakpoint at PC inserted, as otherwise if the handler
2700 recurses and executes PC again, it'll miss the breakpoint.
2701 So we leave the breakpoint inserted anyway, but we need to
2702 record that we tried to step a breakpoint instruction, so
2703 that adjust_pc_after_break doesn't end up confused.
2705 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2706 in one thread after another thread that was stepping had been
2707 momentarily paused for a step-over. When we re-resume the
2708 stepping thread, it may be resumed from that address with a
2709 breakpoint that hasn't trapped yet. Seen with
2710 gdb.threads/non-stop-fair-events.exp, on targets that don't
2711 do displaced stepping. */
2714 fprintf_unfiltered (gdb_stdlog
,
2715 "infrun: resume: [%s] stepped breakpoint\n",
2716 target_pid_to_str (tp
->ptid
));
2718 tp
->stepped_breakpoint
= 1;
2720 /* Most targets can step a breakpoint instruction, thus
2721 executing it normally. But if this one cannot, just
2722 continue and we will hit it anyway. */
2723 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2728 && tp
->control
.trap_expected
2729 && use_displaced_stepping (tp
)
2730 && !step_over_info_valid_p ())
2732 struct regcache
*resume_regcache
= get_thread_regcache (tp
->ptid
);
2733 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2734 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2737 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2738 paddress (resume_gdbarch
, actual_pc
));
2739 read_memory (actual_pc
, buf
, sizeof (buf
));
2740 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2743 if (tp
->control
.may_range_step
)
2745 /* If we're resuming a thread with the PC out of the step
2746 range, then we're doing some nested/finer run control
2747 operation, like stepping the thread out of the dynamic
2748 linker or the displaced stepping scratch pad. We
2749 shouldn't have allowed a range step then. */
2750 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2753 do_target_resume (resume_ptid
, step
, sig
);
2755 discard_cleanups (old_cleanups
);
2762 /* Counter that tracks number of user visible stops. This can be used
2763 to tell whether a command has proceeded the inferior past the
2764 current location. This allows e.g., inferior function calls in
2765 breakpoint commands to not interrupt the command list. When the
2766 call finishes successfully, the inferior is standing at the same
2767 breakpoint as if nothing happened (and so we don't call
2769 static ULONGEST current_stop_id
;
2776 return current_stop_id
;
2779 /* Called when we report a user visible stop. */
2787 /* Clear out all variables saying what to do when inferior is continued.
2788 First do this, then set the ones you want, then call `proceed'. */
2791 clear_proceed_status_thread (struct thread_info
*tp
)
2794 fprintf_unfiltered (gdb_stdlog
,
2795 "infrun: clear_proceed_status_thread (%s)\n",
2796 target_pid_to_str (tp
->ptid
));
2798 /* If we're starting a new sequence, then the previous finished
2799 single-step is no longer relevant. */
2800 if (tp
->suspend
.waitstatus_pending_p
)
2802 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2805 fprintf_unfiltered (gdb_stdlog
,
2806 "infrun: clear_proceed_status: pending "
2807 "event of %s was a finished step. "
2809 target_pid_to_str (tp
->ptid
));
2811 tp
->suspend
.waitstatus_pending_p
= 0;
2812 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2814 else if (debug_infrun
)
2817 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2819 fprintf_unfiltered (gdb_stdlog
,
2820 "infrun: clear_proceed_status_thread: thread %s "
2821 "has pending wait status %s "
2822 "(currently_stepping=%d).\n",
2823 target_pid_to_str (tp
->ptid
), statstr
.c_str (),
2824 currently_stepping (tp
));
2828 /* If this signal should not be seen by program, give it zero.
2829 Used for debugging signals. */
2830 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2831 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2833 thread_fsm_delete (tp
->thread_fsm
);
2834 tp
->thread_fsm
= NULL
;
2836 tp
->control
.trap_expected
= 0;
2837 tp
->control
.step_range_start
= 0;
2838 tp
->control
.step_range_end
= 0;
2839 tp
->control
.may_range_step
= 0;
2840 tp
->control
.step_frame_id
= null_frame_id
;
2841 tp
->control
.step_stack_frame_id
= null_frame_id
;
2842 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2843 tp
->control
.step_start_function
= NULL
;
2844 tp
->stop_requested
= 0;
2846 tp
->control
.stop_step
= 0;
2848 tp
->control
.proceed_to_finish
= 0;
2850 tp
->control
.stepping_command
= 0;
2852 /* Discard any remaining commands or status from previous stop. */
2853 bpstat_clear (&tp
->control
.stop_bpstat
);
2857 clear_proceed_status (int step
)
2859 /* With scheduler-locking replay, stop replaying other threads if we're
2860 not replaying the user-visible resume ptid.
2862 This is a convenience feature to not require the user to explicitly
2863 stop replaying the other threads. We're assuming that the user's
2864 intent is to resume tracing the recorded process. */
2865 if (!non_stop
&& scheduler_mode
== schedlock_replay
2866 && target_record_is_replaying (minus_one_ptid
)
2867 && !target_record_will_replay (user_visible_resume_ptid (step
),
2868 execution_direction
))
2869 target_record_stop_replaying ();
2873 struct thread_info
*tp
;
2876 resume_ptid
= user_visible_resume_ptid (step
);
2878 /* In all-stop mode, delete the per-thread status of all threads
2879 we're about to resume, implicitly and explicitly. */
2880 ALL_NON_EXITED_THREADS (tp
)
2882 if (!ptid_match (tp
->ptid
, resume_ptid
))
2884 clear_proceed_status_thread (tp
);
2888 if (!ptid_equal (inferior_ptid
, null_ptid
))
2890 struct inferior
*inferior
;
2894 /* If in non-stop mode, only delete the per-thread status of
2895 the current thread. */
2896 clear_proceed_status_thread (inferior_thread ());
2899 inferior
= current_inferior ();
2900 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2903 observer_notify_about_to_proceed ();
2906 /* Returns true if TP is still stopped at a breakpoint that needs
2907 stepping-over in order to make progress. If the breakpoint is gone
2908 meanwhile, we can skip the whole step-over dance. */
2911 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2913 if (tp
->stepping_over_breakpoint
)
2915 struct regcache
*regcache
= get_thread_regcache (tp
->ptid
);
2917 if (breakpoint_here_p (regcache
->aspace (),
2918 regcache_read_pc (regcache
))
2919 == ordinary_breakpoint_here
)
2922 tp
->stepping_over_breakpoint
= 0;
2928 /* Check whether thread TP still needs to start a step-over in order
2929 to make progress when resumed. Returns an bitwise or of enum
2930 step_over_what bits, indicating what needs to be stepped over. */
2932 static step_over_what
2933 thread_still_needs_step_over (struct thread_info
*tp
)
2935 step_over_what what
= 0;
2937 if (thread_still_needs_step_over_bp (tp
))
2938 what
|= STEP_OVER_BREAKPOINT
;
2940 if (tp
->stepping_over_watchpoint
2941 && !target_have_steppable_watchpoint
)
2942 what
|= STEP_OVER_WATCHPOINT
;
2947 /* Returns true if scheduler locking applies. STEP indicates whether
2948 we're about to do a step/next-like command to a thread. */
2951 schedlock_applies (struct thread_info
*tp
)
2953 return (scheduler_mode
== schedlock_on
2954 || (scheduler_mode
== schedlock_step
2955 && tp
->control
.stepping_command
)
2956 || (scheduler_mode
== schedlock_replay
2957 && target_record_will_replay (minus_one_ptid
,
2958 execution_direction
)));
2961 /* Basic routine for continuing the program in various fashions.
2963 ADDR is the address to resume at, or -1 for resume where stopped.
2964 SIGGNAL is the signal to give it, or 0 for none,
2965 or -1 for act according to how it stopped.
2966 STEP is nonzero if should trap after one instruction.
2967 -1 means return after that and print nothing.
2968 You should probably set various step_... variables
2969 before calling here, if you are stepping.
2971 You should call clear_proceed_status before calling proceed. */
2974 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2976 struct regcache
*regcache
;
2977 struct gdbarch
*gdbarch
;
2978 struct thread_info
*tp
;
2981 struct execution_control_state ecss
;
2982 struct execution_control_state
*ecs
= &ecss
;
2983 struct cleanup
*old_chain
;
2986 /* If we're stopped at a fork/vfork, follow the branch set by the
2987 "set follow-fork-mode" command; otherwise, we'll just proceed
2988 resuming the current thread. */
2989 if (!follow_fork ())
2991 /* The target for some reason decided not to resume. */
2993 if (target_can_async_p ())
2994 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2998 /* We'll update this if & when we switch to a new thread. */
2999 previous_inferior_ptid
= inferior_ptid
;
3001 regcache
= get_current_regcache ();
3002 gdbarch
= regcache
->arch ();
3003 const address_space
*aspace
= regcache
->aspace ();
3005 pc
= regcache_read_pc (regcache
);
3006 tp
= inferior_thread ();
3008 /* Fill in with reasonable starting values. */
3009 init_thread_stepping_state (tp
);
3011 gdb_assert (!thread_is_in_step_over_chain (tp
));
3013 if (addr
== (CORE_ADDR
) -1)
3016 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3017 && execution_direction
!= EXEC_REVERSE
)
3018 /* There is a breakpoint at the address we will resume at,
3019 step one instruction before inserting breakpoints so that
3020 we do not stop right away (and report a second hit at this
3023 Note, we don't do this in reverse, because we won't
3024 actually be executing the breakpoint insn anyway.
3025 We'll be (un-)executing the previous instruction. */
3026 tp
->stepping_over_breakpoint
= 1;
3027 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3028 && gdbarch_single_step_through_delay (gdbarch
,
3029 get_current_frame ()))
3030 /* We stepped onto an instruction that needs to be stepped
3031 again before re-inserting the breakpoint, do so. */
3032 tp
->stepping_over_breakpoint
= 1;
3036 regcache_write_pc (regcache
, addr
);
3039 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3040 tp
->suspend
.stop_signal
= siggnal
;
3042 resume_ptid
= user_visible_resume_ptid (tp
->control
.stepping_command
);
3044 /* If an exception is thrown from this point on, make sure to
3045 propagate GDB's knowledge of the executing state to the
3046 frontend/user running state. */
3047 old_chain
= make_cleanup (finish_thread_state_cleanup
, &resume_ptid
);
3049 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3050 threads (e.g., we might need to set threads stepping over
3051 breakpoints first), from the user/frontend's point of view, all
3052 threads in RESUME_PTID are now running. Unless we're calling an
3053 inferior function, as in that case we pretend the inferior
3054 doesn't run at all. */
3055 if (!tp
->control
.in_infcall
)
3056 set_running (resume_ptid
, 1);
3059 fprintf_unfiltered (gdb_stdlog
,
3060 "infrun: proceed (addr=%s, signal=%s)\n",
3061 paddress (gdbarch
, addr
),
3062 gdb_signal_to_symbol_string (siggnal
));
3064 annotate_starting ();
3066 /* Make sure that output from GDB appears before output from the
3068 gdb_flush (gdb_stdout
);
3070 /* In a multi-threaded task we may select another thread and
3071 then continue or step.
3073 But if a thread that we're resuming had stopped at a breakpoint,
3074 it will immediately cause another breakpoint stop without any
3075 execution (i.e. it will report a breakpoint hit incorrectly). So
3076 we must step over it first.
3078 Look for threads other than the current (TP) that reported a
3079 breakpoint hit and haven't been resumed yet since. */
3081 /* If scheduler locking applies, we can avoid iterating over all
3083 if (!non_stop
&& !schedlock_applies (tp
))
3085 struct thread_info
*current
= tp
;
3087 ALL_NON_EXITED_THREADS (tp
)
3089 /* Ignore the current thread here. It's handled
3094 /* Ignore threads of processes we're not resuming. */
3095 if (!ptid_match (tp
->ptid
, resume_ptid
))
3098 if (!thread_still_needs_step_over (tp
))
3101 gdb_assert (!thread_is_in_step_over_chain (tp
));
3104 fprintf_unfiltered (gdb_stdlog
,
3105 "infrun: need to step-over [%s] first\n",
3106 target_pid_to_str (tp
->ptid
));
3108 thread_step_over_chain_enqueue (tp
);
3114 /* Enqueue the current thread last, so that we move all other
3115 threads over their breakpoints first. */
3116 if (tp
->stepping_over_breakpoint
)
3117 thread_step_over_chain_enqueue (tp
);
3119 /* If the thread isn't started, we'll still need to set its prev_pc,
3120 so that switch_back_to_stepped_thread knows the thread hasn't
3121 advanced. Must do this before resuming any thread, as in
3122 all-stop/remote, once we resume we can't send any other packet
3123 until the target stops again. */
3124 tp
->prev_pc
= regcache_read_pc (regcache
);
3127 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3129 started
= start_step_over ();
3131 if (step_over_info_valid_p ())
3133 /* Either this thread started a new in-line step over, or some
3134 other thread was already doing one. In either case, don't
3135 resume anything else until the step-over is finished. */
3137 else if (started
&& !target_is_non_stop_p ())
3139 /* A new displaced stepping sequence was started. In all-stop,
3140 we can't talk to the target anymore until it next stops. */
3142 else if (!non_stop
&& target_is_non_stop_p ())
3144 /* In all-stop, but the target is always in non-stop mode.
3145 Start all other threads that are implicitly resumed too. */
3146 ALL_NON_EXITED_THREADS (tp
)
3148 /* Ignore threads of processes we're not resuming. */
3149 if (!ptid_match (tp
->ptid
, resume_ptid
))
3155 fprintf_unfiltered (gdb_stdlog
,
3156 "infrun: proceed: [%s] resumed\n",
3157 target_pid_to_str (tp
->ptid
));
3158 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3162 if (thread_is_in_step_over_chain (tp
))
3165 fprintf_unfiltered (gdb_stdlog
,
3166 "infrun: proceed: [%s] needs step-over\n",
3167 target_pid_to_str (tp
->ptid
));
3172 fprintf_unfiltered (gdb_stdlog
,
3173 "infrun: proceed: resuming %s\n",
3174 target_pid_to_str (tp
->ptid
));
3176 reset_ecs (ecs
, tp
);
3177 switch_to_thread (tp
->ptid
);
3178 keep_going_pass_signal (ecs
);
3179 if (!ecs
->wait_some_more
)
3180 error (_("Command aborted."));
3183 else if (!tp
->resumed
&& !thread_is_in_step_over_chain (tp
))
3185 /* The thread wasn't started, and isn't queued, run it now. */
3186 reset_ecs (ecs
, tp
);
3187 switch_to_thread (tp
->ptid
);
3188 keep_going_pass_signal (ecs
);
3189 if (!ecs
->wait_some_more
)
3190 error (_("Command aborted."));
3194 target_commit_resume ();
3196 discard_cleanups (old_chain
);
3198 /* Tell the event loop to wait for it to stop. If the target
3199 supports asynchronous execution, it'll do this from within
3201 if (!target_can_async_p ())
3202 mark_async_event_handler (infrun_async_inferior_event_token
);
3206 /* Start remote-debugging of a machine over a serial link. */
3209 start_remote (int from_tty
)
3211 struct inferior
*inferior
;
3213 inferior
= current_inferior ();
3214 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3216 /* Always go on waiting for the target, regardless of the mode. */
3217 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3218 indicate to wait_for_inferior that a target should timeout if
3219 nothing is returned (instead of just blocking). Because of this,
3220 targets expecting an immediate response need to, internally, set
3221 things up so that the target_wait() is forced to eventually
3223 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3224 differentiate to its caller what the state of the target is after
3225 the initial open has been performed. Here we're assuming that
3226 the target has stopped. It should be possible to eventually have
3227 target_open() return to the caller an indication that the target
3228 is currently running and GDB state should be set to the same as
3229 for an async run. */
3230 wait_for_inferior ();
3232 /* Now that the inferior has stopped, do any bookkeeping like
3233 loading shared libraries. We want to do this before normal_stop,
3234 so that the displayed frame is up to date. */
3235 post_create_inferior (¤t_target
, from_tty
);
3240 /* Initialize static vars when a new inferior begins. */
3243 init_wait_for_inferior (void)
3245 /* These are meaningless until the first time through wait_for_inferior. */
3247 breakpoint_init_inferior (inf_starting
);
3249 clear_proceed_status (0);
3251 target_last_wait_ptid
= minus_one_ptid
;
3253 previous_inferior_ptid
= inferior_ptid
;
3255 /* Discard any skipped inlined frames. */
3256 clear_inline_frame_state (minus_one_ptid
);
3261 static void handle_inferior_event (struct execution_control_state
*ecs
);
3263 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3264 struct execution_control_state
*ecs
);
3265 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3266 struct execution_control_state
*ecs
);
3267 static void handle_signal_stop (struct execution_control_state
*ecs
);
3268 static void check_exception_resume (struct execution_control_state
*,
3269 struct frame_info
*);
3271 static void end_stepping_range (struct execution_control_state
*ecs
);
3272 static void stop_waiting (struct execution_control_state
*ecs
);
3273 static void keep_going (struct execution_control_state
*ecs
);
3274 static void process_event_stop_test (struct execution_control_state
*ecs
);
3275 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3277 /* This function is attached as a "thread_stop_requested" observer.
3278 Cleanup local state that assumed the PTID was to be resumed, and
3279 report the stop to the frontend. */
3282 infrun_thread_stop_requested (ptid_t ptid
)
3284 struct thread_info
*tp
;
3286 /* PTID was requested to stop. If the thread was already stopped,
3287 but the user/frontend doesn't know about that yet (e.g., the
3288 thread had been temporarily paused for some step-over), set up
3289 for reporting the stop now. */
3290 ALL_NON_EXITED_THREADS (tp
)
3291 if (ptid_match (tp
->ptid
, ptid
))
3293 if (tp
->state
!= THREAD_RUNNING
)
3298 /* Remove matching threads from the step-over queue, so
3299 start_step_over doesn't try to resume them
3301 if (thread_is_in_step_over_chain (tp
))
3302 thread_step_over_chain_remove (tp
);
3304 /* If the thread is stopped, but the user/frontend doesn't
3305 know about that yet, queue a pending event, as if the
3306 thread had just stopped now. Unless the thread already had
3308 if (!tp
->suspend
.waitstatus_pending_p
)
3310 tp
->suspend
.waitstatus_pending_p
= 1;
3311 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3312 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3315 /* Clear the inline-frame state, since we're re-processing the
3317 clear_inline_frame_state (tp
->ptid
);
3319 /* If this thread was paused because some other thread was
3320 doing an inline-step over, let that finish first. Once
3321 that happens, we'll restart all threads and consume pending
3322 stop events then. */
3323 if (step_over_info_valid_p ())
3326 /* Otherwise we can process the (new) pending event now. Set
3327 it so this pending event is considered by
3334 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3336 if (ptid_equal (target_last_wait_ptid
, tp
->ptid
))
3337 nullify_last_target_wait_ptid ();
3340 /* Delete the step resume, single-step and longjmp/exception resume
3341 breakpoints of TP. */
3344 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3346 delete_step_resume_breakpoint (tp
);
3347 delete_exception_resume_breakpoint (tp
);
3348 delete_single_step_breakpoints (tp
);
3351 /* If the target still has execution, call FUNC for each thread that
3352 just stopped. In all-stop, that's all the non-exited threads; in
3353 non-stop, that's the current thread, only. */
3355 typedef void (*for_each_just_stopped_thread_callback_func
)
3356 (struct thread_info
*tp
);
3359 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3361 if (!target_has_execution
|| ptid_equal (inferior_ptid
, null_ptid
))
3364 if (target_is_non_stop_p ())
3366 /* If in non-stop mode, only the current thread stopped. */
3367 func (inferior_thread ());
3371 struct thread_info
*tp
;
3373 /* In all-stop mode, all threads have stopped. */
3374 ALL_NON_EXITED_THREADS (tp
)
3381 /* Delete the step resume and longjmp/exception resume breakpoints of
3382 the threads that just stopped. */
3385 delete_just_stopped_threads_infrun_breakpoints (void)
3387 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3390 /* Delete the single-step breakpoints of the threads that just
3394 delete_just_stopped_threads_single_step_breakpoints (void)
3396 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3399 /* A cleanup wrapper. */
3402 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg
)
3404 delete_just_stopped_threads_infrun_breakpoints ();
3410 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3411 const struct target_waitstatus
*ws
)
3413 std::string status_string
= target_waitstatus_to_string (ws
);
3416 /* The text is split over several lines because it was getting too long.
3417 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3418 output as a unit; we want only one timestamp printed if debug_timestamp
3421 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3422 ptid_get_pid (waiton_ptid
),
3423 ptid_get_lwp (waiton_ptid
),
3424 ptid_get_tid (waiton_ptid
));
3425 if (ptid_get_pid (waiton_ptid
) != -1)
3426 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
));
3427 stb
.printf (", status) =\n");
3428 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3429 ptid_get_pid (result_ptid
),
3430 ptid_get_lwp (result_ptid
),
3431 ptid_get_tid (result_ptid
),
3432 target_pid_to_str (result_ptid
));
3433 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3435 /* This uses %s in part to handle %'s in the text, but also to avoid
3436 a gcc error: the format attribute requires a string literal. */
3437 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3440 /* Select a thread at random, out of those which are resumed and have
3443 static struct thread_info
*
3444 random_pending_event_thread (ptid_t waiton_ptid
)
3446 struct thread_info
*event_tp
;
3448 int random_selector
;
3450 /* First see how many events we have. Count only resumed threads
3451 that have an event pending. */
3452 ALL_NON_EXITED_THREADS (event_tp
)
3453 if (ptid_match (event_tp
->ptid
, waiton_ptid
)
3454 && event_tp
->resumed
3455 && event_tp
->suspend
.waitstatus_pending_p
)
3458 if (num_events
== 0)
3461 /* Now randomly pick a thread out of those that have had events. */
3462 random_selector
= (int)
3463 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
3465 if (debug_infrun
&& num_events
> 1)
3466 fprintf_unfiltered (gdb_stdlog
,
3467 "infrun: Found %d events, selecting #%d\n",
3468 num_events
, random_selector
);
3470 /* Select the Nth thread that has had an event. */
3471 ALL_NON_EXITED_THREADS (event_tp
)
3472 if (ptid_match (event_tp
->ptid
, waiton_ptid
)
3473 && event_tp
->resumed
3474 && event_tp
->suspend
.waitstatus_pending_p
)
3475 if (random_selector
-- == 0)
3481 /* Wrapper for target_wait that first checks whether threads have
3482 pending statuses to report before actually asking the target for
3486 do_target_wait (ptid_t ptid
, struct target_waitstatus
*status
, int options
)
3489 struct thread_info
*tp
;
3491 /* First check if there is a resumed thread with a wait status
3493 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3495 tp
= random_pending_event_thread (ptid
);
3500 fprintf_unfiltered (gdb_stdlog
,
3501 "infrun: Waiting for specific thread %s.\n",
3502 target_pid_to_str (ptid
));
3504 /* We have a specific thread to check. */
3505 tp
= find_thread_ptid (ptid
);
3506 gdb_assert (tp
!= NULL
);
3507 if (!tp
->suspend
.waitstatus_pending_p
)
3512 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3513 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3515 struct regcache
*regcache
= get_thread_regcache (tp
->ptid
);
3516 struct gdbarch
*gdbarch
= regcache
->arch ();
3520 pc
= regcache_read_pc (regcache
);
3522 if (pc
!= tp
->suspend
.stop_pc
)
3525 fprintf_unfiltered (gdb_stdlog
,
3526 "infrun: PC of %s changed. was=%s, now=%s\n",
3527 target_pid_to_str (tp
->ptid
),
3528 paddress (gdbarch
, tp
->prev_pc
),
3529 paddress (gdbarch
, pc
));
3532 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3535 fprintf_unfiltered (gdb_stdlog
,
3536 "infrun: previous breakpoint of %s, at %s gone\n",
3537 target_pid_to_str (tp
->ptid
),
3538 paddress (gdbarch
, pc
));
3546 fprintf_unfiltered (gdb_stdlog
,
3547 "infrun: pending event of %s cancelled.\n",
3548 target_pid_to_str (tp
->ptid
));
3550 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3551 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3560 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3562 fprintf_unfiltered (gdb_stdlog
,
3563 "infrun: Using pending wait status %s for %s.\n",
3565 target_pid_to_str (tp
->ptid
));
3568 /* Now that we've selected our final event LWP, un-adjust its PC
3569 if it was a software breakpoint (and the target doesn't
3570 always adjust the PC itself). */
3571 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3572 && !target_supports_stopped_by_sw_breakpoint ())
3574 struct regcache
*regcache
;
3575 struct gdbarch
*gdbarch
;
3578 regcache
= get_thread_regcache (tp
->ptid
);
3579 gdbarch
= regcache
->arch ();
3581 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3586 pc
= regcache_read_pc (regcache
);
3587 regcache_write_pc (regcache
, pc
+ decr_pc
);
3591 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3592 *status
= tp
->suspend
.waitstatus
;
3593 tp
->suspend
.waitstatus_pending_p
= 0;
3595 /* Wake up the event loop again, until all pending events are
3597 if (target_is_async_p ())
3598 mark_async_event_handler (infrun_async_inferior_event_token
);
3602 /* But if we don't find one, we'll have to wait. */
3604 if (deprecated_target_wait_hook
)
3605 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3607 event_ptid
= target_wait (ptid
, status
, options
);
3612 /* Prepare and stabilize the inferior for detaching it. E.g.,
3613 detaching while a thread is displaced stepping is a recipe for
3614 crashing it, as nothing would readjust the PC out of the scratch
3618 prepare_for_detach (void)
3620 struct inferior
*inf
= current_inferior ();
3621 ptid_t pid_ptid
= pid_to_ptid (inf
->pid
);
3622 struct displaced_step_inferior_state
*displaced
;
3624 displaced
= get_displaced_stepping_state (inf
->pid
);
3626 /* Is any thread of this process displaced stepping? If not,
3627 there's nothing else to do. */
3628 if (displaced
== NULL
|| ptid_equal (displaced
->step_ptid
, null_ptid
))
3632 fprintf_unfiltered (gdb_stdlog
,
3633 "displaced-stepping in-process while detaching");
3635 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3637 while (!ptid_equal (displaced
->step_ptid
, null_ptid
))
3639 struct cleanup
*old_chain_2
;
3640 struct execution_control_state ecss
;
3641 struct execution_control_state
*ecs
;
3644 memset (ecs
, 0, sizeof (*ecs
));
3646 overlay_cache_invalid
= 1;
3647 /* Flush target cache before starting to handle each event.
3648 Target was running and cache could be stale. This is just a
3649 heuristic. Running threads may modify target memory, but we
3650 don't get any event. */
3651 target_dcache_invalidate ();
3653 ecs
->ptid
= do_target_wait (pid_ptid
, &ecs
->ws
, 0);
3656 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3658 /* If an error happens while handling the event, propagate GDB's
3659 knowledge of the executing state to the frontend/user running
3661 old_chain_2
= make_cleanup (finish_thread_state_cleanup
,
3664 /* Now figure out what to do with the result of the result. */
3665 handle_inferior_event (ecs
);
3667 /* No error, don't finish the state yet. */
3668 discard_cleanups (old_chain_2
);
3670 /* Breakpoints and watchpoints are not installed on the target
3671 at this point, and signals are passed directly to the
3672 inferior, so this must mean the process is gone. */
3673 if (!ecs
->wait_some_more
)
3675 restore_detaching
.release ();
3676 error (_("Program exited while detaching"));
3680 restore_detaching
.release ();
3683 /* Wait for control to return from inferior to debugger.
3685 If inferior gets a signal, we may decide to start it up again
3686 instead of returning. That is why there is a loop in this function.
3687 When this function actually returns it means the inferior
3688 should be left stopped and GDB should read more commands. */
3691 wait_for_inferior (void)
3693 struct cleanup
*old_cleanups
;
3694 struct cleanup
*thread_state_chain
;
3698 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3701 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
,
3704 /* If an error happens while handling the event, propagate GDB's
3705 knowledge of the executing state to the frontend/user running
3707 thread_state_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
3711 struct execution_control_state ecss
;
3712 struct execution_control_state
*ecs
= &ecss
;
3713 ptid_t waiton_ptid
= minus_one_ptid
;
3715 memset (ecs
, 0, sizeof (*ecs
));
3717 overlay_cache_invalid
= 1;
3719 /* Flush target cache before starting to handle each event.
3720 Target was running and cache could be stale. This is just a
3721 heuristic. Running threads may modify target memory, but we
3722 don't get any event. */
3723 target_dcache_invalidate ();
3725 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
, 0);
3728 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3730 /* Now figure out what to do with the result of the result. */
3731 handle_inferior_event (ecs
);
3733 if (!ecs
->wait_some_more
)
3737 /* No error, don't finish the state yet. */
3738 discard_cleanups (thread_state_chain
);
3740 do_cleanups (old_cleanups
);
3743 /* Cleanup that reinstalls the readline callback handler, if the
3744 target is running in the background. If while handling the target
3745 event something triggered a secondary prompt, like e.g., a
3746 pagination prompt, we'll have removed the callback handler (see
3747 gdb_readline_wrapper_line). Need to do this as we go back to the
3748 event loop, ready to process further input. Note this has no
3749 effect if the handler hasn't actually been removed, because calling
3750 rl_callback_handler_install resets the line buffer, thus losing
3754 reinstall_readline_callback_handler_cleanup (void *arg
)
3756 struct ui
*ui
= current_ui
;
3760 /* We're not going back to the top level event loop yet. Don't
3761 install the readline callback, as it'd prep the terminal,
3762 readline-style (raw, noecho) (e.g., --batch). We'll install
3763 it the next time the prompt is displayed, when we're ready
3768 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3769 gdb_rl_callback_handler_reinstall ();
3772 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3773 that's just the event thread. In all-stop, that's all threads. */
3776 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3778 struct thread_info
*thr
= ecs
->event_thread
;
3780 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3781 thread_fsm_clean_up (thr
->thread_fsm
, thr
);
3785 ALL_NON_EXITED_THREADS (thr
)
3787 if (thr
->thread_fsm
== NULL
)
3789 if (thr
== ecs
->event_thread
)
3792 switch_to_thread (thr
->ptid
);
3793 thread_fsm_clean_up (thr
->thread_fsm
, thr
);
3796 if (ecs
->event_thread
!= NULL
)
3797 switch_to_thread (ecs
->event_thread
->ptid
);
3801 /* Helper for all_uis_check_sync_execution_done that works on the
3805 check_curr_ui_sync_execution_done (void)
3807 struct ui
*ui
= current_ui
;
3809 if (ui
->prompt_state
== PROMPT_NEEDED
3811 && !gdb_in_secondary_prompt_p (ui
))
3813 target_terminal::ours ();
3814 observer_notify_sync_execution_done ();
3815 ui_register_input_event_handler (ui
);
3822 all_uis_check_sync_execution_done (void)
3824 SWITCH_THRU_ALL_UIS ()
3826 check_curr_ui_sync_execution_done ();
3833 all_uis_on_sync_execution_starting (void)
3835 SWITCH_THRU_ALL_UIS ()
3837 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3838 async_disable_stdin ();
3842 /* Asynchronous version of wait_for_inferior. It is called by the
3843 event loop whenever a change of state is detected on the file
3844 descriptor corresponding to the target. It can be called more than
3845 once to complete a single execution command. In such cases we need
3846 to keep the state in a global variable ECSS. If it is the last time
3847 that this function is called for a single execution command, then
3848 report to the user that the inferior has stopped, and do the
3849 necessary cleanups. */
3852 fetch_inferior_event (void *client_data
)
3854 struct execution_control_state ecss
;
3855 struct execution_control_state
*ecs
= &ecss
;
3856 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
3857 struct cleanup
*ts_old_chain
;
3859 ptid_t waiton_ptid
= minus_one_ptid
;
3861 memset (ecs
, 0, sizeof (*ecs
));
3863 /* Events are always processed with the main UI as current UI. This
3864 way, warnings, debug output, etc. are always consistently sent to
3865 the main console. */
3866 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3868 /* End up with readline processing input, if necessary. */
3869 make_cleanup (reinstall_readline_callback_handler_cleanup
, NULL
);
3871 /* We're handling a live event, so make sure we're doing live
3872 debugging. If we're looking at traceframes while the target is
3873 running, we're going to need to get back to that mode after
3874 handling the event. */
3877 make_cleanup_restore_current_traceframe ();
3878 set_current_traceframe (-1);
3881 gdb::optional
<scoped_restore_current_thread
> maybe_restore_thread
;
3884 /* In non-stop mode, the user/frontend should not notice a thread
3885 switch due to internal events. Make sure we reverse to the
3886 user selected thread and frame after handling the event and
3887 running any breakpoint commands. */
3888 maybe_restore_thread
.emplace ();
3890 overlay_cache_invalid
= 1;
3891 /* Flush target cache before starting to handle each event. Target
3892 was running and cache could be stale. This is just a heuristic.
3893 Running threads may modify target memory, but we don't get any
3895 target_dcache_invalidate ();
3897 scoped_restore save_exec_dir
3898 = make_scoped_restore (&execution_direction
, target_execution_direction ());
3900 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
,
3901 target_can_async_p () ? TARGET_WNOHANG
: 0);
3904 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3906 /* If an error happens while handling the event, propagate GDB's
3907 knowledge of the executing state to the frontend/user running
3909 if (!target_is_non_stop_p ())
3910 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
3912 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &ecs
->ptid
);
3914 /* Get executed before make_cleanup_restore_current_thread above to apply
3915 still for the thread which has thrown the exception. */
3916 make_bpstat_clear_actions_cleanup ();
3918 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
, NULL
);
3920 /* Now figure out what to do with the result of the result. */
3921 handle_inferior_event (ecs
);
3923 if (!ecs
->wait_some_more
)
3925 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3926 int should_stop
= 1;
3927 struct thread_info
*thr
= ecs
->event_thread
;
3928 int should_notify_stop
= 1;
3930 delete_just_stopped_threads_infrun_breakpoints ();
3934 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3936 if (thread_fsm
!= NULL
)
3937 should_stop
= thread_fsm_should_stop (thread_fsm
, thr
);
3946 clean_up_just_stopped_threads_fsms (ecs
);
3948 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3951 = thread_fsm_should_notify_stop (thr
->thread_fsm
);
3954 if (should_notify_stop
)
3958 /* We may not find an inferior if this was a process exit. */
3959 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3960 proceeded
= normal_stop ();
3964 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3971 /* No error, don't finish the thread states yet. */
3972 discard_cleanups (ts_old_chain
);
3974 /* Revert thread and frame. */
3975 do_cleanups (old_chain
);
3977 /* If a UI was in sync execution mode, and now isn't, restore its
3978 prompt (a synchronous execution command has finished, and we're
3979 ready for input). */
3980 all_uis_check_sync_execution_done ();
3983 && exec_done_display_p
3984 && (ptid_equal (inferior_ptid
, null_ptid
)
3985 || !is_running (inferior_ptid
)))
3986 printf_unfiltered (_("completed.\n"));
3989 /* Record the frame and location we're currently stepping through. */
3991 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3993 struct thread_info
*tp
= inferior_thread ();
3995 tp
->control
.step_frame_id
= get_frame_id (frame
);
3996 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3998 tp
->current_symtab
= sal
.symtab
;
3999 tp
->current_line
= sal
.line
;
4002 /* Clear context switchable stepping state. */
4005 init_thread_stepping_state (struct thread_info
*tss
)
4007 tss
->stepped_breakpoint
= 0;
4008 tss
->stepping_over_breakpoint
= 0;
4009 tss
->stepping_over_watchpoint
= 0;
4010 tss
->step_after_step_resume_breakpoint
= 0;
4013 /* Set the cached copy of the last ptid/waitstatus. */
4016 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
4018 target_last_wait_ptid
= ptid
;
4019 target_last_waitstatus
= status
;
4022 /* Return the cached copy of the last pid/waitstatus returned by
4023 target_wait()/deprecated_target_wait_hook(). The data is actually
4024 cached by handle_inferior_event(), which gets called immediately
4025 after target_wait()/deprecated_target_wait_hook(). */
4028 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
4030 *ptidp
= target_last_wait_ptid
;
4031 *status
= target_last_waitstatus
;
4035 nullify_last_target_wait_ptid (void)
4037 target_last_wait_ptid
= minus_one_ptid
;
4040 /* Switch thread contexts. */
4043 context_switch (ptid_t ptid
)
4045 if (debug_infrun
&& !ptid_equal (ptid
, inferior_ptid
))
4047 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4048 target_pid_to_str (inferior_ptid
));
4049 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4050 target_pid_to_str (ptid
));
4053 switch_to_thread (ptid
);
4056 /* If the target can't tell whether we've hit breakpoints
4057 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4058 check whether that could have been caused by a breakpoint. If so,
4059 adjust the PC, per gdbarch_decr_pc_after_break. */
4062 adjust_pc_after_break (struct thread_info
*thread
,
4063 struct target_waitstatus
*ws
)
4065 struct regcache
*regcache
;
4066 struct gdbarch
*gdbarch
;
4067 CORE_ADDR breakpoint_pc
, decr_pc
;
4069 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4070 we aren't, just return.
4072 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4073 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4074 implemented by software breakpoints should be handled through the normal
4077 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4078 different signals (SIGILL or SIGEMT for instance), but it is less
4079 clear where the PC is pointing afterwards. It may not match
4080 gdbarch_decr_pc_after_break. I don't know any specific target that
4081 generates these signals at breakpoints (the code has been in GDB since at
4082 least 1992) so I can not guess how to handle them here.
4084 In earlier versions of GDB, a target with
4085 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4086 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4087 target with both of these set in GDB history, and it seems unlikely to be
4088 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4090 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4093 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4096 /* In reverse execution, when a breakpoint is hit, the instruction
4097 under it has already been de-executed. The reported PC always
4098 points at the breakpoint address, so adjusting it further would
4099 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4102 B1 0x08000000 : INSN1
4103 B2 0x08000001 : INSN2
4105 PC -> 0x08000003 : INSN4
4107 Say you're stopped at 0x08000003 as above. Reverse continuing
4108 from that point should hit B2 as below. Reading the PC when the
4109 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4110 been de-executed already.
4112 B1 0x08000000 : INSN1
4113 B2 PC -> 0x08000001 : INSN2
4117 We can't apply the same logic as for forward execution, because
4118 we would wrongly adjust the PC to 0x08000000, since there's a
4119 breakpoint at PC - 1. We'd then report a hit on B1, although
4120 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4122 if (execution_direction
== EXEC_REVERSE
)
4125 /* If the target can tell whether the thread hit a SW breakpoint,
4126 trust it. Targets that can tell also adjust the PC
4128 if (target_supports_stopped_by_sw_breakpoint ())
4131 /* Note that relying on whether a breakpoint is planted in memory to
4132 determine this can fail. E.g,. the breakpoint could have been
4133 removed since. Or the thread could have been told to step an
4134 instruction the size of a breakpoint instruction, and only
4135 _after_ was a breakpoint inserted at its address. */
4137 /* If this target does not decrement the PC after breakpoints, then
4138 we have nothing to do. */
4139 regcache
= get_thread_regcache (thread
->ptid
);
4140 gdbarch
= regcache
->arch ();
4142 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4146 const address_space
*aspace
= regcache
->aspace ();
4148 /* Find the location where (if we've hit a breakpoint) the
4149 breakpoint would be. */
4150 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4152 /* If the target can't tell whether a software breakpoint triggered,
4153 fallback to figuring it out based on breakpoints we think were
4154 inserted in the target, and on whether the thread was stepped or
4157 /* Check whether there actually is a software breakpoint inserted at
4160 If in non-stop mode, a race condition is possible where we've
4161 removed a breakpoint, but stop events for that breakpoint were
4162 already queued and arrive later. To suppress those spurious
4163 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4164 and retire them after a number of stop events are reported. Note
4165 this is an heuristic and can thus get confused. The real fix is
4166 to get the "stopped by SW BP and needs adjustment" info out of
4167 the target/kernel (and thus never reach here; see above). */
4168 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4169 || (target_is_non_stop_p ()
4170 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4172 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4174 if (record_full_is_used ())
4175 restore_operation_disable
.emplace
4176 (record_full_gdb_operation_disable_set ());
4178 /* When using hardware single-step, a SIGTRAP is reported for both
4179 a completed single-step and a software breakpoint. Need to
4180 differentiate between the two, as the latter needs adjusting
4181 but the former does not.
4183 The SIGTRAP can be due to a completed hardware single-step only if
4184 - we didn't insert software single-step breakpoints
4185 - this thread is currently being stepped
4187 If any of these events did not occur, we must have stopped due
4188 to hitting a software breakpoint, and have to back up to the
4191 As a special case, we could have hardware single-stepped a
4192 software breakpoint. In this case (prev_pc == breakpoint_pc),
4193 we also need to back up to the breakpoint address. */
4195 if (thread_has_single_step_breakpoints_set (thread
)
4196 || !currently_stepping (thread
)
4197 || (thread
->stepped_breakpoint
4198 && thread
->prev_pc
== breakpoint_pc
))
4199 regcache_write_pc (regcache
, breakpoint_pc
);
4204 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4206 for (frame
= get_prev_frame (frame
);
4208 frame
= get_prev_frame (frame
))
4210 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4212 if (get_frame_type (frame
) != INLINE_FRAME
)
4219 /* If the event thread has the stop requested flag set, pretend it
4220 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4224 handle_stop_requested (struct execution_control_state
*ecs
)
4226 if (ecs
->event_thread
->stop_requested
)
4228 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4229 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4230 handle_signal_stop (ecs
);
4236 /* Auxiliary function that handles syscall entry/return events.
4237 It returns 1 if the inferior should keep going (and GDB
4238 should ignore the event), or 0 if the event deserves to be
4242 handle_syscall_event (struct execution_control_state
*ecs
)
4244 struct regcache
*regcache
;
4247 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4248 context_switch (ecs
->ptid
);
4250 regcache
= get_thread_regcache (ecs
->ptid
);
4251 syscall_number
= ecs
->ws
.value
.syscall_number
;
4252 stop_pc
= regcache_read_pc (regcache
);
4254 if (catch_syscall_enabled () > 0
4255 && catching_syscall_number (syscall_number
) > 0)
4258 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4261 ecs
->event_thread
->control
.stop_bpstat
4262 = bpstat_stop_status (regcache
->aspace (),
4263 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4265 if (handle_stop_requested (ecs
))
4268 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4270 /* Catchpoint hit. */
4275 if (handle_stop_requested (ecs
))
4278 /* If no catchpoint triggered for this, then keep going. */
4283 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4286 fill_in_stop_func (struct gdbarch
*gdbarch
,
4287 struct execution_control_state
*ecs
)
4289 if (!ecs
->stop_func_filled_in
)
4291 /* Don't care about return value; stop_func_start and stop_func_name
4292 will both be 0 if it doesn't work. */
4293 find_pc_partial_function (stop_pc
, &ecs
->stop_func_name
,
4294 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
4295 ecs
->stop_func_start
4296 += gdbarch_deprecated_function_start_offset (gdbarch
);
4298 if (gdbarch_skip_entrypoint_p (gdbarch
))
4299 ecs
->stop_func_start
= gdbarch_skip_entrypoint (gdbarch
,
4300 ecs
->stop_func_start
);
4302 ecs
->stop_func_filled_in
= 1;
4307 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4309 static enum stop_kind
4310 get_inferior_stop_soon (ptid_t ptid
)
4312 struct inferior
*inf
= find_inferior_ptid (ptid
);
4314 gdb_assert (inf
!= NULL
);
4315 return inf
->control
.stop_soon
;
4318 /* Wait for one event. Store the resulting waitstatus in WS, and
4319 return the event ptid. */
4322 wait_one (struct target_waitstatus
*ws
)
4325 ptid_t wait_ptid
= minus_one_ptid
;
4327 overlay_cache_invalid
= 1;
4329 /* Flush target cache before starting to handle each event.
4330 Target was running and cache could be stale. This is just a
4331 heuristic. Running threads may modify target memory, but we
4332 don't get any event. */
4333 target_dcache_invalidate ();
4335 if (deprecated_target_wait_hook
)
4336 event_ptid
= deprecated_target_wait_hook (wait_ptid
, ws
, 0);
4338 event_ptid
= target_wait (wait_ptid
, ws
, 0);
4341 print_target_wait_results (wait_ptid
, event_ptid
, ws
);
4346 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4347 instead of the current thread. */
4348 #define THREAD_STOPPED_BY(REASON) \
4350 thread_stopped_by_ ## REASON (ptid_t ptid) \
4352 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4353 inferior_ptid = ptid; \
4355 return target_stopped_by_ ## REASON (); \
4358 /* Generate thread_stopped_by_watchpoint. */
4359 THREAD_STOPPED_BY (watchpoint
)
4360 /* Generate thread_stopped_by_sw_breakpoint. */
4361 THREAD_STOPPED_BY (sw_breakpoint
)
4362 /* Generate thread_stopped_by_hw_breakpoint. */
4363 THREAD_STOPPED_BY (hw_breakpoint
)
4365 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4368 switch_to_thread_cleanup (void *ptid_p
)
4370 ptid_t ptid
= *(ptid_t
*) ptid_p
;
4372 switch_to_thread (ptid
);
4375 /* Save the thread's event and stop reason to process it later. */
4378 save_waitstatus (struct thread_info
*tp
, struct target_waitstatus
*ws
)
4380 struct regcache
*regcache
;
4384 std::string statstr
= target_waitstatus_to_string (ws
);
4386 fprintf_unfiltered (gdb_stdlog
,
4387 "infrun: saving status %s for %d.%ld.%ld\n",
4389 ptid_get_pid (tp
->ptid
),
4390 ptid_get_lwp (tp
->ptid
),
4391 ptid_get_tid (tp
->ptid
));
4394 /* Record for later. */
4395 tp
->suspend
.waitstatus
= *ws
;
4396 tp
->suspend
.waitstatus_pending_p
= 1;
4398 regcache
= get_thread_regcache (tp
->ptid
);
4399 const address_space
*aspace
= regcache
->aspace ();
4401 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4402 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4404 CORE_ADDR pc
= regcache_read_pc (regcache
);
4406 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4408 if (thread_stopped_by_watchpoint (tp
->ptid
))
4410 tp
->suspend
.stop_reason
4411 = TARGET_STOPPED_BY_WATCHPOINT
;
4413 else if (target_supports_stopped_by_sw_breakpoint ()
4414 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4416 tp
->suspend
.stop_reason
4417 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4419 else if (target_supports_stopped_by_hw_breakpoint ()
4420 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4422 tp
->suspend
.stop_reason
4423 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4425 else if (!target_supports_stopped_by_hw_breakpoint ()
4426 && hardware_breakpoint_inserted_here_p (aspace
,
4429 tp
->suspend
.stop_reason
4430 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4432 else if (!target_supports_stopped_by_sw_breakpoint ()
4433 && software_breakpoint_inserted_here_p (aspace
,
4436 tp
->suspend
.stop_reason
4437 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4439 else if (!thread_has_single_step_breakpoints_set (tp
)
4440 && currently_stepping (tp
))
4442 tp
->suspend
.stop_reason
4443 = TARGET_STOPPED_BY_SINGLE_STEP
;
4448 /* A cleanup that disables thread create/exit events. */
4451 disable_thread_events (void *arg
)
4453 target_thread_events (0);
4459 stop_all_threads (void)
4461 /* We may need multiple passes to discover all threads. */
4465 struct cleanup
*old_chain
;
4467 gdb_assert (target_is_non_stop_p ());
4470 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4472 entry_ptid
= inferior_ptid
;
4473 old_chain
= make_cleanup (switch_to_thread_cleanup
, &entry_ptid
);
4475 target_thread_events (1);
4476 make_cleanup (disable_thread_events
, NULL
);
4478 /* Request threads to stop, and then wait for the stops. Because
4479 threads we already know about can spawn more threads while we're
4480 trying to stop them, and we only learn about new threads when we
4481 update the thread list, do this in a loop, and keep iterating
4482 until two passes find no threads that need to be stopped. */
4483 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4486 fprintf_unfiltered (gdb_stdlog
,
4487 "infrun: stop_all_threads, pass=%d, "
4488 "iterations=%d\n", pass
, iterations
);
4492 struct target_waitstatus ws
;
4494 struct thread_info
*t
;
4496 update_thread_list ();
4498 /* Go through all threads looking for threads that we need
4499 to tell the target to stop. */
4500 ALL_NON_EXITED_THREADS (t
)
4504 /* If already stopping, don't request a stop again.
4505 We just haven't seen the notification yet. */
4506 if (!t
->stop_requested
)
4509 fprintf_unfiltered (gdb_stdlog
,
4510 "infrun: %s executing, "
4512 target_pid_to_str (t
->ptid
));
4513 target_stop (t
->ptid
);
4514 t
->stop_requested
= 1;
4519 fprintf_unfiltered (gdb_stdlog
,
4520 "infrun: %s executing, "
4521 "already stopping\n",
4522 target_pid_to_str (t
->ptid
));
4525 if (t
->stop_requested
)
4531 fprintf_unfiltered (gdb_stdlog
,
4532 "infrun: %s not executing\n",
4533 target_pid_to_str (t
->ptid
));
4535 /* The thread may be not executing, but still be
4536 resumed with a pending status to process. */
4544 /* If we find new threads on the second iteration, restart
4545 over. We want to see two iterations in a row with all
4550 event_ptid
= wait_one (&ws
);
4551 if (ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4553 /* All resumed threads exited. */
4555 else if (ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4556 || ws
.kind
== TARGET_WAITKIND_EXITED
4557 || ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4561 ptid_t ptid
= pid_to_ptid (ws
.value
.integer
);
4563 fprintf_unfiltered (gdb_stdlog
,
4564 "infrun: %s exited while "
4565 "stopping threads\n",
4566 target_pid_to_str (ptid
));
4571 struct inferior
*inf
;
4573 t
= find_thread_ptid (event_ptid
);
4575 t
= add_thread (event_ptid
);
4577 t
->stop_requested
= 0;
4580 t
->control
.may_range_step
= 0;
4582 /* This may be the first time we see the inferior report
4584 inf
= find_inferior_ptid (event_ptid
);
4585 if (inf
->needs_setup
)
4587 switch_to_thread_no_regs (t
);
4591 if (ws
.kind
== TARGET_WAITKIND_STOPPED
4592 && ws
.value
.sig
== GDB_SIGNAL_0
)
4594 /* We caught the event that we intended to catch, so
4595 there's no event pending. */
4596 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4597 t
->suspend
.waitstatus_pending_p
= 0;
4599 if (displaced_step_fixup (t
->ptid
, GDB_SIGNAL_0
) < 0)
4601 /* Add it back to the step-over queue. */
4604 fprintf_unfiltered (gdb_stdlog
,
4605 "infrun: displaced-step of %s "
4606 "canceled: adding back to the "
4607 "step-over queue\n",
4608 target_pid_to_str (t
->ptid
));
4610 t
->control
.trap_expected
= 0;
4611 thread_step_over_chain_enqueue (t
);
4616 enum gdb_signal sig
;
4617 struct regcache
*regcache
;
4621 std::string statstr
= target_waitstatus_to_string (&ws
);
4623 fprintf_unfiltered (gdb_stdlog
,
4624 "infrun: target_wait %s, saving "
4625 "status for %d.%ld.%ld\n",
4627 ptid_get_pid (t
->ptid
),
4628 ptid_get_lwp (t
->ptid
),
4629 ptid_get_tid (t
->ptid
));
4632 /* Record for later. */
4633 save_waitstatus (t
, &ws
);
4635 sig
= (ws
.kind
== TARGET_WAITKIND_STOPPED
4636 ? ws
.value
.sig
: GDB_SIGNAL_0
);
4638 if (displaced_step_fixup (t
->ptid
, sig
) < 0)
4640 /* Add it back to the step-over queue. */
4641 t
->control
.trap_expected
= 0;
4642 thread_step_over_chain_enqueue (t
);
4645 regcache
= get_thread_regcache (t
->ptid
);
4646 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4650 fprintf_unfiltered (gdb_stdlog
,
4651 "infrun: saved stop_pc=%s for %s "
4652 "(currently_stepping=%d)\n",
4653 paddress (target_gdbarch (),
4654 t
->suspend
.stop_pc
),
4655 target_pid_to_str (t
->ptid
),
4656 currently_stepping (t
));
4663 do_cleanups (old_chain
);
4666 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4669 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4672 handle_no_resumed (struct execution_control_state
*ecs
)
4674 struct inferior
*inf
;
4675 struct thread_info
*thread
;
4677 if (target_can_async_p ())
4684 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4692 /* There were no unwaited-for children left in the target, but,
4693 we're not synchronously waiting for events either. Just
4697 fprintf_unfiltered (gdb_stdlog
,
4698 "infrun: TARGET_WAITKIND_NO_RESUMED "
4699 "(ignoring: bg)\n");
4700 prepare_to_wait (ecs
);
4705 /* Otherwise, if we were running a synchronous execution command, we
4706 may need to cancel it and give the user back the terminal.
4708 In non-stop mode, the target can't tell whether we've already
4709 consumed previous stop events, so it can end up sending us a
4710 no-resumed event like so:
4712 #0 - thread 1 is left stopped
4714 #1 - thread 2 is resumed and hits breakpoint
4715 -> TARGET_WAITKIND_STOPPED
4717 #2 - thread 3 is resumed and exits
4718 this is the last resumed thread, so
4719 -> TARGET_WAITKIND_NO_RESUMED
4721 #3 - gdb processes stop for thread 2 and decides to re-resume
4724 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4725 thread 2 is now resumed, so the event should be ignored.
4727 IOW, if the stop for thread 2 doesn't end a foreground command,
4728 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4729 event. But it could be that the event meant that thread 2 itself
4730 (or whatever other thread was the last resumed thread) exited.
4732 To address this we refresh the thread list and check whether we
4733 have resumed threads _now_. In the example above, this removes
4734 thread 3 from the thread list. If thread 2 was re-resumed, we
4735 ignore this event. If we find no thread resumed, then we cancel
4736 the synchronous command show "no unwaited-for " to the user. */
4737 update_thread_list ();
4739 ALL_NON_EXITED_THREADS (thread
)
4741 if (thread
->executing
4742 || thread
->suspend
.waitstatus_pending_p
)
4744 /* There were no unwaited-for children left in the target at
4745 some point, but there are now. Just ignore. */
4747 fprintf_unfiltered (gdb_stdlog
,
4748 "infrun: TARGET_WAITKIND_NO_RESUMED "
4749 "(ignoring: found resumed)\n");
4750 prepare_to_wait (ecs
);
4755 /* Note however that we may find no resumed thread because the whole
4756 process exited meanwhile (thus updating the thread list results
4757 in an empty thread list). In this case we know we'll be getting
4758 a process exit event shortly. */
4764 thread
= any_live_thread_of_process (inf
->pid
);
4768 fprintf_unfiltered (gdb_stdlog
,
4769 "infrun: TARGET_WAITKIND_NO_RESUMED "
4770 "(expect process exit)\n");
4771 prepare_to_wait (ecs
);
4776 /* Go ahead and report the event. */
4780 /* Given an execution control state that has been freshly filled in by
4781 an event from the inferior, figure out what it means and take
4784 The alternatives are:
4786 1) stop_waiting and return; to really stop and return to the
4789 2) keep_going and return; to wait for the next event (set
4790 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4794 handle_inferior_event_1 (struct execution_control_state
*ecs
)
4796 enum stop_kind stop_soon
;
4798 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4800 /* We had an event in the inferior, but we are not interested in
4801 handling it at this level. The lower layers have already
4802 done what needs to be done, if anything.
4804 One of the possible circumstances for this is when the
4805 inferior produces output for the console. The inferior has
4806 not stopped, and we are ignoring the event. Another possible
4807 circumstance is any event which the lower level knows will be
4808 reported multiple times without an intervening resume. */
4810 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
4811 prepare_to_wait (ecs
);
4815 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4818 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4819 prepare_to_wait (ecs
);
4823 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4824 && handle_no_resumed (ecs
))
4827 /* Cache the last pid/waitstatus. */
4828 set_last_target_status (ecs
->ptid
, ecs
->ws
);
4830 /* Always clear state belonging to the previous time we stopped. */
4831 stop_stack_dummy
= STOP_NONE
;
4833 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4835 /* No unwaited-for children left. IOW, all resumed children
4838 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4840 stop_print_frame
= 0;
4845 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
4846 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
4848 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
4849 /* If it's a new thread, add it to the thread database. */
4850 if (ecs
->event_thread
== NULL
)
4851 ecs
->event_thread
= add_thread (ecs
->ptid
);
4853 /* Disable range stepping. If the next step request could use a
4854 range, this will be end up re-enabled then. */
4855 ecs
->event_thread
->control
.may_range_step
= 0;
4858 /* Dependent on valid ECS->EVENT_THREAD. */
4859 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
4861 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4862 reinit_frame_cache ();
4864 breakpoint_retire_moribund ();
4866 /* First, distinguish signals caused by the debugger from signals
4867 that have to do with the program's own actions. Note that
4868 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4869 on the operating system version. Here we detect when a SIGILL or
4870 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4871 something similar for SIGSEGV, since a SIGSEGV will be generated
4872 when we're trying to execute a breakpoint instruction on a
4873 non-executable stack. This happens for call dummy breakpoints
4874 for architectures like SPARC that place call dummies on the
4876 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
4877 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
4878 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
4879 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
4881 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
4883 if (breakpoint_inserted_here_p (regcache
->aspace (),
4884 regcache_read_pc (regcache
)))
4887 fprintf_unfiltered (gdb_stdlog
,
4888 "infrun: Treating signal as SIGTRAP\n");
4889 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
4893 /* Mark the non-executing threads accordingly. In all-stop, all
4894 threads of all processes are stopped when we get any event
4895 reported. In non-stop mode, only the event thread stops. */
4899 if (!target_is_non_stop_p ())
4900 mark_ptid
= minus_one_ptid
;
4901 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
4902 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4904 /* If we're handling a process exit in non-stop mode, even
4905 though threads haven't been deleted yet, one would think
4906 that there is nothing to do, as threads of the dead process
4907 will be soon deleted, and threads of any other process were
4908 left running. However, on some targets, threads survive a
4909 process exit event. E.g., for the "checkpoint" command,
4910 when the current checkpoint/fork exits, linux-fork.c
4911 automatically switches to another fork from within
4912 target_mourn_inferior, by associating the same
4913 inferior/thread to another fork. We haven't mourned yet at
4914 this point, but we must mark any threads left in the
4915 process as not-executing so that finish_thread_state marks
4916 them stopped (in the user's perspective) if/when we present
4917 the stop to the user. */
4918 mark_ptid
= pid_to_ptid (ptid_get_pid (ecs
->ptid
));
4921 mark_ptid
= ecs
->ptid
;
4923 set_executing (mark_ptid
, 0);
4925 /* Likewise the resumed flag. */
4926 set_resumed (mark_ptid
, 0);
4929 switch (ecs
->ws
.kind
)
4931 case TARGET_WAITKIND_LOADED
:
4933 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
4934 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
4935 context_switch (ecs
->ptid
);
4936 /* Ignore gracefully during startup of the inferior, as it might
4937 be the shell which has just loaded some objects, otherwise
4938 add the symbols for the newly loaded objects. Also ignore at
4939 the beginning of an attach or remote session; we will query
4940 the full list of libraries once the connection is
4943 stop_soon
= get_inferior_stop_soon (ecs
->ptid
);
4944 if (stop_soon
== NO_STOP_QUIETLY
)
4946 struct regcache
*regcache
;
4948 regcache
= get_thread_regcache (ecs
->ptid
);
4950 handle_solib_event ();
4952 ecs
->event_thread
->control
.stop_bpstat
4953 = bpstat_stop_status (regcache
->aspace (),
4954 stop_pc
, ecs
->ptid
, &ecs
->ws
);
4956 if (handle_stop_requested (ecs
))
4959 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4961 /* A catchpoint triggered. */
4962 process_event_stop_test (ecs
);
4966 /* If requested, stop when the dynamic linker notifies
4967 gdb of events. This allows the user to get control
4968 and place breakpoints in initializer routines for
4969 dynamically loaded objects (among other things). */
4970 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4971 if (stop_on_solib_events
)
4973 /* Make sure we print "Stopped due to solib-event" in
4975 stop_print_frame
= 1;
4982 /* If we are skipping through a shell, or through shared library
4983 loading that we aren't interested in, resume the program. If
4984 we're running the program normally, also resume. */
4985 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
4987 /* Loading of shared libraries might have changed breakpoint
4988 addresses. Make sure new breakpoints are inserted. */
4989 if (stop_soon
== NO_STOP_QUIETLY
)
4990 insert_breakpoints ();
4991 resume (GDB_SIGNAL_0
);
4992 prepare_to_wait (ecs
);
4996 /* But stop if we're attaching or setting up a remote
4998 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4999 || stop_soon
== STOP_QUIETLY_REMOTE
)
5002 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5007 internal_error (__FILE__
, __LINE__
,
5008 _("unhandled stop_soon: %d"), (int) stop_soon
);
5010 case TARGET_WAITKIND_SPURIOUS
:
5012 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5013 if (handle_stop_requested (ecs
))
5015 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5016 context_switch (ecs
->ptid
);
5017 resume (GDB_SIGNAL_0
);
5018 prepare_to_wait (ecs
);
5021 case TARGET_WAITKIND_THREAD_CREATED
:
5023 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5024 if (handle_stop_requested (ecs
))
5026 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5027 context_switch (ecs
->ptid
);
5028 if (!switch_back_to_stepped_thread (ecs
))
5032 case TARGET_WAITKIND_EXITED
:
5033 case TARGET_WAITKIND_SIGNALLED
:
5036 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5037 fprintf_unfiltered (gdb_stdlog
,
5038 "infrun: TARGET_WAITKIND_EXITED\n");
5040 fprintf_unfiltered (gdb_stdlog
,
5041 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5044 inferior_ptid
= ecs
->ptid
;
5045 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
5046 set_current_program_space (current_inferior ()->pspace
);
5047 handle_vfork_child_exec_or_exit (0);
5048 target_terminal::ours (); /* Must do this before mourn anyway. */
5050 /* Clearing any previous state of convenience variables. */
5051 clear_exit_convenience_vars ();
5053 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5055 /* Record the exit code in the convenience variable $_exitcode, so
5056 that the user can inspect this again later. */
5057 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5058 (LONGEST
) ecs
->ws
.value
.integer
);
5060 /* Also record this in the inferior itself. */
5061 current_inferior ()->has_exit_code
= 1;
5062 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5064 /* Support the --return-child-result option. */
5065 return_child_result_value
= ecs
->ws
.value
.integer
;
5067 observer_notify_exited (ecs
->ws
.value
.integer
);
5071 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
5072 struct gdbarch
*gdbarch
= regcache
->arch ();
5074 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5076 /* Set the value of the internal variable $_exitsignal,
5077 which holds the signal uncaught by the inferior. */
5078 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5079 gdbarch_gdb_signal_to_target (gdbarch
,
5080 ecs
->ws
.value
.sig
));
5084 /* We don't have access to the target's method used for
5085 converting between signal numbers (GDB's internal
5086 representation <-> target's representation).
5087 Therefore, we cannot do a good job at displaying this
5088 information to the user. It's better to just warn
5089 her about it (if infrun debugging is enabled), and
5092 fprintf_filtered (gdb_stdlog
, _("\
5093 Cannot fill $_exitsignal with the correct signal number.\n"));
5096 observer_notify_signal_exited (ecs
->ws
.value
.sig
);
5099 gdb_flush (gdb_stdout
);
5100 target_mourn_inferior (inferior_ptid
);
5101 stop_print_frame
= 0;
5105 /* The following are the only cases in which we keep going;
5106 the above cases end in a continue or goto. */
5107 case TARGET_WAITKIND_FORKED
:
5108 case TARGET_WAITKIND_VFORKED
:
5111 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5112 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
5114 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_VFORKED\n");
5117 /* Check whether the inferior is displaced stepping. */
5119 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
5120 struct gdbarch
*gdbarch
= regcache
->arch ();
5122 /* If checking displaced stepping is supported, and thread
5123 ecs->ptid is displaced stepping. */
5124 if (displaced_step_in_progress_thread (ecs
->ptid
))
5126 struct inferior
*parent_inf
5127 = find_inferior_ptid (ecs
->ptid
);
5128 struct regcache
*child_regcache
;
5129 CORE_ADDR parent_pc
;
5131 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5132 indicating that the displaced stepping of syscall instruction
5133 has been done. Perform cleanup for parent process here. Note
5134 that this operation also cleans up the child process for vfork,
5135 because their pages are shared. */
5136 displaced_step_fixup (ecs
->ptid
, GDB_SIGNAL_TRAP
);
5137 /* Start a new step-over in another thread if there's one
5141 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5143 struct displaced_step_inferior_state
*displaced
5144 = get_displaced_stepping_state (ptid_get_pid (ecs
->ptid
));
5146 /* Restore scratch pad for child process. */
5147 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5150 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5151 the child's PC is also within the scratchpad. Set the child's PC
5152 to the parent's PC value, which has already been fixed up.
5153 FIXME: we use the parent's aspace here, although we're touching
5154 the child, because the child hasn't been added to the inferior
5155 list yet at this point. */
5158 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
5160 parent_inf
->aspace
);
5161 /* Read PC value of parent process. */
5162 parent_pc
= regcache_read_pc (regcache
);
5164 if (debug_displaced
)
5165 fprintf_unfiltered (gdb_stdlog
,
5166 "displaced: write child pc from %s to %s\n",
5168 regcache_read_pc (child_regcache
)),
5169 paddress (gdbarch
, parent_pc
));
5171 regcache_write_pc (child_regcache
, parent_pc
);
5175 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5176 context_switch (ecs
->ptid
);
5178 /* Immediately detach breakpoints from the child before there's
5179 any chance of letting the user delete breakpoints from the
5180 breakpoint lists. If we don't do this early, it's easy to
5181 leave left over traps in the child, vis: "break foo; catch
5182 fork; c; <fork>; del; c; <child calls foo>". We only follow
5183 the fork on the last `continue', and by that time the
5184 breakpoint at "foo" is long gone from the breakpoint table.
5185 If we vforked, then we don't need to unpatch here, since both
5186 parent and child are sharing the same memory pages; we'll
5187 need to unpatch at follow/detach time instead to be certain
5188 that new breakpoints added between catchpoint hit time and
5189 vfork follow are detached. */
5190 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5192 /* This won't actually modify the breakpoint list, but will
5193 physically remove the breakpoints from the child. */
5194 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5197 delete_just_stopped_threads_single_step_breakpoints ();
5199 /* In case the event is caught by a catchpoint, remember that
5200 the event is to be followed at the next resume of the thread,
5201 and not immediately. */
5202 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5204 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5206 ecs
->event_thread
->control
.stop_bpstat
5207 = bpstat_stop_status (get_current_regcache ()->aspace (),
5208 stop_pc
, ecs
->ptid
, &ecs
->ws
);
5210 if (handle_stop_requested (ecs
))
5213 /* If no catchpoint triggered for this, then keep going. Note
5214 that we're interested in knowing the bpstat actually causes a
5215 stop, not just if it may explain the signal. Software
5216 watchpoints, for example, always appear in the bpstat. */
5217 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5223 = (follow_fork_mode_string
== follow_fork_mode_child
);
5225 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5227 should_resume
= follow_fork ();
5230 child
= ecs
->ws
.value
.related_pid
;
5232 /* At this point, the parent is marked running, and the
5233 child is marked stopped. */
5235 /* If not resuming the parent, mark it stopped. */
5236 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5237 set_running (parent
, 0);
5239 /* If resuming the child, mark it running. */
5240 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5241 set_running (child
, 1);
5243 /* In non-stop mode, also resume the other branch. */
5244 if (!detach_fork
&& (non_stop
5245 || (sched_multi
&& target_is_non_stop_p ())))
5248 switch_to_thread (parent
);
5250 switch_to_thread (child
);
5252 ecs
->event_thread
= inferior_thread ();
5253 ecs
->ptid
= inferior_ptid
;
5258 switch_to_thread (child
);
5260 switch_to_thread (parent
);
5262 ecs
->event_thread
= inferior_thread ();
5263 ecs
->ptid
= inferior_ptid
;
5271 process_event_stop_test (ecs
);
5274 case TARGET_WAITKIND_VFORK_DONE
:
5275 /* Done with the shared memory region. Re-insert breakpoints in
5276 the parent, and keep going. */
5279 fprintf_unfiltered (gdb_stdlog
,
5280 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5282 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5283 context_switch (ecs
->ptid
);
5285 current_inferior ()->waiting_for_vfork_done
= 0;
5286 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5288 if (handle_stop_requested (ecs
))
5291 /* This also takes care of reinserting breakpoints in the
5292 previously locked inferior. */
5296 case TARGET_WAITKIND_EXECD
:
5298 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
5300 /* Note we can't read registers yet (the stop_pc), because we
5301 don't yet know the inferior's post-exec architecture.
5302 'stop_pc' is explicitly read below instead. */
5303 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5304 switch_to_thread_no_regs (ecs
->event_thread
);
5306 /* Do whatever is necessary to the parent branch of the vfork. */
5307 handle_vfork_child_exec_or_exit (1);
5309 /* This causes the eventpoints and symbol table to be reset.
5310 Must do this now, before trying to determine whether to
5312 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5314 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5316 /* In follow_exec we may have deleted the original thread and
5317 created a new one. Make sure that the event thread is the
5318 execd thread for that case (this is a nop otherwise). */
5319 ecs
->event_thread
= inferior_thread ();
5321 ecs
->event_thread
->control
.stop_bpstat
5322 = bpstat_stop_status (get_current_regcache ()->aspace (),
5323 stop_pc
, ecs
->ptid
, &ecs
->ws
);
5325 /* Note that this may be referenced from inside
5326 bpstat_stop_status above, through inferior_has_execd. */
5327 xfree (ecs
->ws
.value
.execd_pathname
);
5328 ecs
->ws
.value
.execd_pathname
= NULL
;
5330 if (handle_stop_requested (ecs
))
5333 /* If no catchpoint triggered for this, then keep going. */
5334 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5336 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5340 process_event_stop_test (ecs
);
5343 /* Be careful not to try to gather much state about a thread
5344 that's in a syscall. It's frequently a losing proposition. */
5345 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5347 fprintf_unfiltered (gdb_stdlog
,
5348 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5349 /* Getting the current syscall number. */
5350 if (handle_syscall_event (ecs
) == 0)
5351 process_event_stop_test (ecs
);
5354 /* Before examining the threads further, step this thread to
5355 get it entirely out of the syscall. (We get notice of the
5356 event when the thread is just on the verge of exiting a
5357 syscall. Stepping one instruction seems to get it back
5359 case TARGET_WAITKIND_SYSCALL_RETURN
:
5361 fprintf_unfiltered (gdb_stdlog
,
5362 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5363 if (handle_syscall_event (ecs
) == 0)
5364 process_event_stop_test (ecs
);
5367 case TARGET_WAITKIND_STOPPED
:
5369 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
5370 handle_signal_stop (ecs
);
5373 case TARGET_WAITKIND_NO_HISTORY
:
5375 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5376 /* Reverse execution: target ran out of history info. */
5378 /* Switch to the stopped thread. */
5379 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5380 context_switch (ecs
->ptid
);
5382 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5384 delete_just_stopped_threads_single_step_breakpoints ();
5385 stop_pc
= regcache_read_pc (get_thread_regcache (inferior_ptid
));
5387 if (handle_stop_requested (ecs
))
5390 observer_notify_no_history ();
5396 /* A wrapper around handle_inferior_event_1, which also makes sure
5397 that all temporary struct value objects that were created during
5398 the handling of the event get deleted at the end. */
5401 handle_inferior_event (struct execution_control_state
*ecs
)
5403 struct value
*mark
= value_mark ();
5405 handle_inferior_event_1 (ecs
);
5406 /* Purge all temporary values created during the event handling,
5407 as it could be a long time before we return to the command level
5408 where such values would otherwise be purged. */
5409 value_free_to_mark (mark
);
5412 /* Restart threads back to what they were trying to do back when we
5413 paused them for an in-line step-over. The EVENT_THREAD thread is
5417 restart_threads (struct thread_info
*event_thread
)
5419 struct thread_info
*tp
;
5421 /* In case the instruction just stepped spawned a new thread. */
5422 update_thread_list ();
5424 ALL_NON_EXITED_THREADS (tp
)
5426 if (tp
== event_thread
)
5429 fprintf_unfiltered (gdb_stdlog
,
5430 "infrun: restart threads: "
5431 "[%s] is event thread\n",
5432 target_pid_to_str (tp
->ptid
));
5436 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5439 fprintf_unfiltered (gdb_stdlog
,
5440 "infrun: restart threads: "
5441 "[%s] not meant to be running\n",
5442 target_pid_to_str (tp
->ptid
));
5449 fprintf_unfiltered (gdb_stdlog
,
5450 "infrun: restart threads: [%s] resumed\n",
5451 target_pid_to_str (tp
->ptid
));
5452 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5456 if (thread_is_in_step_over_chain (tp
))
5459 fprintf_unfiltered (gdb_stdlog
,
5460 "infrun: restart threads: "
5461 "[%s] needs step-over\n",
5462 target_pid_to_str (tp
->ptid
));
5463 gdb_assert (!tp
->resumed
);
5468 if (tp
->suspend
.waitstatus_pending_p
)
5471 fprintf_unfiltered (gdb_stdlog
,
5472 "infrun: restart threads: "
5473 "[%s] has pending status\n",
5474 target_pid_to_str (tp
->ptid
));
5479 gdb_assert (!tp
->stop_requested
);
5481 /* If some thread needs to start a step-over at this point, it
5482 should still be in the step-over queue, and thus skipped
5484 if (thread_still_needs_step_over (tp
))
5486 internal_error (__FILE__
, __LINE__
,
5487 "thread [%s] needs a step-over, but not in "
5488 "step-over queue\n",
5489 target_pid_to_str (tp
->ptid
));
5492 if (currently_stepping (tp
))
5495 fprintf_unfiltered (gdb_stdlog
,
5496 "infrun: restart threads: [%s] was stepping\n",
5497 target_pid_to_str (tp
->ptid
));
5498 keep_going_stepped_thread (tp
);
5502 struct execution_control_state ecss
;
5503 struct execution_control_state
*ecs
= &ecss
;
5506 fprintf_unfiltered (gdb_stdlog
,
5507 "infrun: restart threads: [%s] continuing\n",
5508 target_pid_to_str (tp
->ptid
));
5509 reset_ecs (ecs
, tp
);
5510 switch_to_thread (tp
->ptid
);
5511 keep_going_pass_signal (ecs
);
5516 /* Callback for iterate_over_threads. Find a resumed thread that has
5517 a pending waitstatus. */
5520 resumed_thread_with_pending_status (struct thread_info
*tp
,
5524 && tp
->suspend
.waitstatus_pending_p
);
5527 /* Called when we get an event that may finish an in-line or
5528 out-of-line (displaced stepping) step-over started previously.
5529 Return true if the event is processed and we should go back to the
5530 event loop; false if the caller should continue processing the
5534 finish_step_over (struct execution_control_state
*ecs
)
5536 int had_step_over_info
;
5538 displaced_step_fixup (ecs
->ptid
,
5539 ecs
->event_thread
->suspend
.stop_signal
);
5541 had_step_over_info
= step_over_info_valid_p ();
5543 if (had_step_over_info
)
5545 /* If we're stepping over a breakpoint with all threads locked,
5546 then only the thread that was stepped should be reporting
5548 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5550 clear_step_over_info ();
5553 if (!target_is_non_stop_p ())
5556 /* Start a new step-over in another thread if there's one that
5560 /* If we were stepping over a breakpoint before, and haven't started
5561 a new in-line step-over sequence, then restart all other threads
5562 (except the event thread). We can't do this in all-stop, as then
5563 e.g., we wouldn't be able to issue any other remote packet until
5564 these other threads stop. */
5565 if (had_step_over_info
&& !step_over_info_valid_p ())
5567 struct thread_info
*pending
;
5569 /* If we only have threads with pending statuses, the restart
5570 below won't restart any thread and so nothing re-inserts the
5571 breakpoint we just stepped over. But we need it inserted
5572 when we later process the pending events, otherwise if
5573 another thread has a pending event for this breakpoint too,
5574 we'd discard its event (because the breakpoint that
5575 originally caused the event was no longer inserted). */
5576 context_switch (ecs
->ptid
);
5577 insert_breakpoints ();
5579 restart_threads (ecs
->event_thread
);
5581 /* If we have events pending, go through handle_inferior_event
5582 again, picking up a pending event at random. This avoids
5583 thread starvation. */
5585 /* But not if we just stepped over a watchpoint in order to let
5586 the instruction execute so we can evaluate its expression.
5587 The set of watchpoints that triggered is recorded in the
5588 breakpoint objects themselves (see bp->watchpoint_triggered).
5589 If we processed another event first, that other event could
5590 clobber this info. */
5591 if (ecs
->event_thread
->stepping_over_watchpoint
)
5594 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5596 if (pending
!= NULL
)
5598 struct thread_info
*tp
= ecs
->event_thread
;
5599 struct regcache
*regcache
;
5603 fprintf_unfiltered (gdb_stdlog
,
5604 "infrun: found resumed threads with "
5605 "pending events, saving status\n");
5608 gdb_assert (pending
!= tp
);
5610 /* Record the event thread's event for later. */
5611 save_waitstatus (tp
, &ecs
->ws
);
5612 /* This was cleared early, by handle_inferior_event. Set it
5613 so this pending event is considered by
5617 gdb_assert (!tp
->executing
);
5619 regcache
= get_thread_regcache (tp
->ptid
);
5620 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5624 fprintf_unfiltered (gdb_stdlog
,
5625 "infrun: saved stop_pc=%s for %s "
5626 "(currently_stepping=%d)\n",
5627 paddress (target_gdbarch (),
5628 tp
->suspend
.stop_pc
),
5629 target_pid_to_str (tp
->ptid
),
5630 currently_stepping (tp
));
5633 /* This in-line step-over finished; clear this so we won't
5634 start a new one. This is what handle_signal_stop would
5635 do, if we returned false. */
5636 tp
->stepping_over_breakpoint
= 0;
5638 /* Wake up the event loop again. */
5639 mark_async_event_handler (infrun_async_inferior_event_token
);
5641 prepare_to_wait (ecs
);
5649 /* Come here when the program has stopped with a signal. */
5652 handle_signal_stop (struct execution_control_state
*ecs
)
5654 struct frame_info
*frame
;
5655 struct gdbarch
*gdbarch
;
5656 int stopped_by_watchpoint
;
5657 enum stop_kind stop_soon
;
5660 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5662 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5664 /* Do we need to clean up the state of a thread that has
5665 completed a displaced single-step? (Doing so usually affects
5666 the PC, so do it here, before we set stop_pc.) */
5667 if (finish_step_over (ecs
))
5670 /* If we either finished a single-step or hit a breakpoint, but
5671 the user wanted this thread to be stopped, pretend we got a
5672 SIG0 (generic unsignaled stop). */
5673 if (ecs
->event_thread
->stop_requested
5674 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5675 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5677 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5681 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
5682 struct gdbarch
*gdbarch
= regcache
->arch ();
5683 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
5685 inferior_ptid
= ecs
->ptid
;
5687 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5688 paddress (gdbarch
, stop_pc
));
5689 if (target_stopped_by_watchpoint ())
5693 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5695 if (target_stopped_data_address (¤t_target
, &addr
))
5696 fprintf_unfiltered (gdb_stdlog
,
5697 "infrun: stopped data address = %s\n",
5698 paddress (gdbarch
, addr
));
5700 fprintf_unfiltered (gdb_stdlog
,
5701 "infrun: (no data address available)\n");
5705 /* This is originated from start_remote(), start_inferior() and
5706 shared libraries hook functions. */
5707 stop_soon
= get_inferior_stop_soon (ecs
->ptid
);
5708 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5710 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5711 context_switch (ecs
->ptid
);
5713 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5714 stop_print_frame
= 1;
5719 /* This originates from attach_command(). We need to overwrite
5720 the stop_signal here, because some kernels don't ignore a
5721 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5722 See more comments in inferior.h. On the other hand, if we
5723 get a non-SIGSTOP, report it to the user - assume the backend
5724 will handle the SIGSTOP if it should show up later.
5726 Also consider that the attach is complete when we see a
5727 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5728 target extended-remote report it instead of a SIGSTOP
5729 (e.g. gdbserver). We already rely on SIGTRAP being our
5730 signal, so this is no exception.
5732 Also consider that the attach is complete when we see a
5733 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5734 the target to stop all threads of the inferior, in case the
5735 low level attach operation doesn't stop them implicitly. If
5736 they weren't stopped implicitly, then the stub will report a
5737 GDB_SIGNAL_0, meaning: stopped for no particular reason
5738 other than GDB's request. */
5739 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5740 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5741 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5742 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5744 stop_print_frame
= 1;
5746 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5750 /* See if something interesting happened to the non-current thread. If
5751 so, then switch to that thread. */
5752 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
5755 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5757 context_switch (ecs
->ptid
);
5759 if (deprecated_context_hook
)
5760 deprecated_context_hook (ptid_to_global_thread_id (ecs
->ptid
));
5763 /* At this point, get hold of the now-current thread's frame. */
5764 frame
= get_current_frame ();
5765 gdbarch
= get_frame_arch (frame
);
5767 /* Pull the single step breakpoints out of the target. */
5768 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5770 struct regcache
*regcache
;
5773 regcache
= get_thread_regcache (ecs
->ptid
);
5774 const address_space
*aspace
= regcache
->aspace ();
5776 pc
= regcache_read_pc (regcache
);
5778 /* However, before doing so, if this single-step breakpoint was
5779 actually for another thread, set this thread up for moving
5781 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5784 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5788 fprintf_unfiltered (gdb_stdlog
,
5789 "infrun: [%s] hit another thread's "
5790 "single-step breakpoint\n",
5791 target_pid_to_str (ecs
->ptid
));
5793 ecs
->hit_singlestep_breakpoint
= 1;
5800 fprintf_unfiltered (gdb_stdlog
,
5801 "infrun: [%s] hit its "
5802 "single-step breakpoint\n",
5803 target_pid_to_str (ecs
->ptid
));
5807 delete_just_stopped_threads_single_step_breakpoints ();
5809 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5810 && ecs
->event_thread
->control
.trap_expected
5811 && ecs
->event_thread
->stepping_over_watchpoint
)
5812 stopped_by_watchpoint
= 0;
5814 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5816 /* If necessary, step over this watchpoint. We'll be back to display
5818 if (stopped_by_watchpoint
5819 && (target_have_steppable_watchpoint
5820 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5822 /* At this point, we are stopped at an instruction which has
5823 attempted to write to a piece of memory under control of
5824 a watchpoint. The instruction hasn't actually executed
5825 yet. If we were to evaluate the watchpoint expression
5826 now, we would get the old value, and therefore no change
5827 would seem to have occurred.
5829 In order to make watchpoints work `right', we really need
5830 to complete the memory write, and then evaluate the
5831 watchpoint expression. We do this by single-stepping the
5834 It may not be necessary to disable the watchpoint to step over
5835 it. For example, the PA can (with some kernel cooperation)
5836 single step over a watchpoint without disabling the watchpoint.
5838 It is far more common to need to disable a watchpoint to step
5839 the inferior over it. If we have non-steppable watchpoints,
5840 we must disable the current watchpoint; it's simplest to
5841 disable all watchpoints.
5843 Any breakpoint at PC must also be stepped over -- if there's
5844 one, it will have already triggered before the watchpoint
5845 triggered, and we either already reported it to the user, or
5846 it didn't cause a stop and we called keep_going. In either
5847 case, if there was a breakpoint at PC, we must be trying to
5849 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5854 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5855 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5856 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5857 ecs
->event_thread
->control
.stop_step
= 0;
5858 stop_print_frame
= 1;
5859 stopped_by_random_signal
= 0;
5861 /* Hide inlined functions starting here, unless we just performed stepi or
5862 nexti. After stepi and nexti, always show the innermost frame (not any
5863 inline function call sites). */
5864 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5866 const address_space
*aspace
=
5867 get_thread_regcache (ecs
->ptid
)->aspace ();
5869 /* skip_inline_frames is expensive, so we avoid it if we can
5870 determine that the address is one where functions cannot have
5871 been inlined. This improves performance with inferiors that
5872 load a lot of shared libraries, because the solib event
5873 breakpoint is defined as the address of a function (i.e. not
5874 inline). Note that we have to check the previous PC as well
5875 as the current one to catch cases when we have just
5876 single-stepped off a breakpoint prior to reinstating it.
5877 Note that we're assuming that the code we single-step to is
5878 not inline, but that's not definitive: there's nothing
5879 preventing the event breakpoint function from containing
5880 inlined code, and the single-step ending up there. If the
5881 user had set a breakpoint on that inlined code, the missing
5882 skip_inline_frames call would break things. Fortunately
5883 that's an extremely unlikely scenario. */
5884 if (!pc_at_non_inline_function (aspace
, stop_pc
, &ecs
->ws
)
5885 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5886 && ecs
->event_thread
->control
.trap_expected
5887 && pc_at_non_inline_function (aspace
,
5888 ecs
->event_thread
->prev_pc
,
5891 skip_inline_frames (ecs
->ptid
);
5893 /* Re-fetch current thread's frame in case that invalidated
5895 frame
= get_current_frame ();
5896 gdbarch
= get_frame_arch (frame
);
5900 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5901 && ecs
->event_thread
->control
.trap_expected
5902 && gdbarch_single_step_through_delay_p (gdbarch
)
5903 && currently_stepping (ecs
->event_thread
))
5905 /* We're trying to step off a breakpoint. Turns out that we're
5906 also on an instruction that needs to be stepped multiple
5907 times before it's been fully executing. E.g., architectures
5908 with a delay slot. It needs to be stepped twice, once for
5909 the instruction and once for the delay slot. */
5910 int step_through_delay
5911 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5913 if (debug_infrun
&& step_through_delay
)
5914 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
5915 if (ecs
->event_thread
->control
.step_range_end
== 0
5916 && step_through_delay
)
5918 /* The user issued a continue when stopped at a breakpoint.
5919 Set up for another trap and get out of here. */
5920 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5924 else if (step_through_delay
)
5926 /* The user issued a step when stopped at a breakpoint.
5927 Maybe we should stop, maybe we should not - the delay
5928 slot *might* correspond to a line of source. In any
5929 case, don't decide that here, just set
5930 ecs->stepping_over_breakpoint, making sure we
5931 single-step again before breakpoints are re-inserted. */
5932 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5936 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5937 handles this event. */
5938 ecs
->event_thread
->control
.stop_bpstat
5939 = bpstat_stop_status (get_current_regcache ()->aspace (),
5940 stop_pc
, ecs
->ptid
, &ecs
->ws
);
5942 /* Following in case break condition called a
5944 stop_print_frame
= 1;
5946 /* This is where we handle "moribund" watchpoints. Unlike
5947 software breakpoints traps, hardware watchpoint traps are
5948 always distinguishable from random traps. If no high-level
5949 watchpoint is associated with the reported stop data address
5950 anymore, then the bpstat does not explain the signal ---
5951 simply make sure to ignore it if `stopped_by_watchpoint' is
5955 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5956 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5958 && stopped_by_watchpoint
)
5959 fprintf_unfiltered (gdb_stdlog
,
5960 "infrun: no user watchpoint explains "
5961 "watchpoint SIGTRAP, ignoring\n");
5963 /* NOTE: cagney/2003-03-29: These checks for a random signal
5964 at one stage in the past included checks for an inferior
5965 function call's call dummy's return breakpoint. The original
5966 comment, that went with the test, read:
5968 ``End of a stack dummy. Some systems (e.g. Sony news) give
5969 another signal besides SIGTRAP, so check here as well as
5972 If someone ever tries to get call dummys on a
5973 non-executable stack to work (where the target would stop
5974 with something like a SIGSEGV), then those tests might need
5975 to be re-instated. Given, however, that the tests were only
5976 enabled when momentary breakpoints were not being used, I
5977 suspect that it won't be the case.
5979 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5980 be necessary for call dummies on a non-executable stack on
5983 /* See if the breakpoints module can explain the signal. */
5985 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5986 ecs
->event_thread
->suspend
.stop_signal
);
5988 /* Maybe this was a trap for a software breakpoint that has since
5990 if (random_signal
&& target_stopped_by_sw_breakpoint ())
5992 if (program_breakpoint_here_p (gdbarch
, stop_pc
))
5994 struct regcache
*regcache
;
5997 /* Re-adjust PC to what the program would see if GDB was not
5999 regcache
= get_thread_regcache (ecs
->event_thread
->ptid
);
6000 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6003 gdb::optional
<scoped_restore_tmpl
<int>>
6004 restore_operation_disable
;
6006 if (record_full_is_used ())
6007 restore_operation_disable
.emplace
6008 (record_full_gdb_operation_disable_set ());
6010 regcache_write_pc (regcache
, stop_pc
+ decr_pc
);
6015 /* A delayed software breakpoint event. Ignore the trap. */
6017 fprintf_unfiltered (gdb_stdlog
,
6018 "infrun: delayed software breakpoint "
6019 "trap, ignoring\n");
6024 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6025 has since been removed. */
6026 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6028 /* A delayed hardware breakpoint event. Ignore the trap. */
6030 fprintf_unfiltered (gdb_stdlog
,
6031 "infrun: delayed hardware breakpoint/watchpoint "
6032 "trap, ignoring\n");
6036 /* If not, perhaps stepping/nexting can. */
6038 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6039 && currently_stepping (ecs
->event_thread
));
6041 /* Perhaps the thread hit a single-step breakpoint of _another_
6042 thread. Single-step breakpoints are transparent to the
6043 breakpoints module. */
6045 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6047 /* No? Perhaps we got a moribund watchpoint. */
6049 random_signal
= !stopped_by_watchpoint
;
6051 /* Always stop if the user explicitly requested this thread to
6053 if (ecs
->event_thread
->stop_requested
)
6057 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6060 /* For the program's own signals, act according to
6061 the signal handling tables. */
6065 /* Signal not for debugging purposes. */
6066 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
6067 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6070 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6071 gdb_signal_to_symbol_string (stop_signal
));
6073 stopped_by_random_signal
= 1;
6075 /* Always stop on signals if we're either just gaining control
6076 of the program, or the user explicitly requested this thread
6077 to remain stopped. */
6078 if (stop_soon
!= NO_STOP_QUIETLY
6079 || ecs
->event_thread
->stop_requested
6081 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6087 /* Notify observers the signal has "handle print" set. Note we
6088 returned early above if stopping; normal_stop handles the
6089 printing in that case. */
6090 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6092 /* The signal table tells us to print about this signal. */
6093 target_terminal::ours_for_output ();
6094 observer_notify_signal_received (ecs
->event_thread
->suspend
.stop_signal
);
6095 target_terminal::inferior ();
6098 /* Clear the signal if it should not be passed. */
6099 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6100 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6102 if (ecs
->event_thread
->prev_pc
== stop_pc
6103 && ecs
->event_thread
->control
.trap_expected
6104 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6106 /* We were just starting a new sequence, attempting to
6107 single-step off of a breakpoint and expecting a SIGTRAP.
6108 Instead this signal arrives. This signal will take us out
6109 of the stepping range so GDB needs to remember to, when
6110 the signal handler returns, resume stepping off that
6112 /* To simplify things, "continue" is forced to use the same
6113 code paths as single-step - set a breakpoint at the
6114 signal return address and then, once hit, step off that
6117 fprintf_unfiltered (gdb_stdlog
,
6118 "infrun: signal arrived while stepping over "
6121 insert_hp_step_resume_breakpoint_at_frame (frame
);
6122 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6123 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6124 ecs
->event_thread
->control
.trap_expected
= 0;
6126 /* If we were nexting/stepping some other thread, switch to
6127 it, so that we don't continue it, losing control. */
6128 if (!switch_back_to_stepped_thread (ecs
))
6133 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6134 && (pc_in_thread_step_range (stop_pc
, ecs
->event_thread
)
6135 || ecs
->event_thread
->control
.step_range_end
== 1)
6136 && frame_id_eq (get_stack_frame_id (frame
),
6137 ecs
->event_thread
->control
.step_stack_frame_id
)
6138 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6140 /* The inferior is about to take a signal that will take it
6141 out of the single step range. Set a breakpoint at the
6142 current PC (which is presumably where the signal handler
6143 will eventually return) and then allow the inferior to
6146 Note that this is only needed for a signal delivered
6147 while in the single-step range. Nested signals aren't a
6148 problem as they eventually all return. */
6150 fprintf_unfiltered (gdb_stdlog
,
6151 "infrun: signal may take us out of "
6152 "single-step range\n");
6154 clear_step_over_info ();
6155 insert_hp_step_resume_breakpoint_at_frame (frame
);
6156 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6157 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6158 ecs
->event_thread
->control
.trap_expected
= 0;
6163 /* Note: step_resume_breakpoint may be non-NULL. This occures
6164 when either there's a nested signal, or when there's a
6165 pending signal enabled just as the signal handler returns
6166 (leaving the inferior at the step-resume-breakpoint without
6167 actually executing it). Either way continue until the
6168 breakpoint is really hit. */
6170 if (!switch_back_to_stepped_thread (ecs
))
6173 fprintf_unfiltered (gdb_stdlog
,
6174 "infrun: random signal, keep going\n");
6181 process_event_stop_test (ecs
);
6184 /* Come here when we've got some debug event / signal we can explain
6185 (IOW, not a random signal), and test whether it should cause a
6186 stop, or whether we should resume the inferior (transparently).
6187 E.g., could be a breakpoint whose condition evaluates false; we
6188 could be still stepping within the line; etc. */
6191 process_event_stop_test (struct execution_control_state
*ecs
)
6193 struct symtab_and_line stop_pc_sal
;
6194 struct frame_info
*frame
;
6195 struct gdbarch
*gdbarch
;
6196 CORE_ADDR jmp_buf_pc
;
6197 struct bpstat_what what
;
6199 /* Handle cases caused by hitting a breakpoint. */
6201 frame
= get_current_frame ();
6202 gdbarch
= get_frame_arch (frame
);
6204 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6206 if (what
.call_dummy
)
6208 stop_stack_dummy
= what
.call_dummy
;
6211 /* A few breakpoint types have callbacks associated (e.g.,
6212 bp_jit_event). Run them now. */
6213 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6215 /* If we hit an internal event that triggers symbol changes, the
6216 current frame will be invalidated within bpstat_what (e.g., if we
6217 hit an internal solib event). Re-fetch it. */
6218 frame
= get_current_frame ();
6219 gdbarch
= get_frame_arch (frame
);
6221 switch (what
.main_action
)
6223 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6224 /* If we hit the breakpoint at longjmp while stepping, we
6225 install a momentary breakpoint at the target of the
6229 fprintf_unfiltered (gdb_stdlog
,
6230 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6232 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6234 if (what
.is_longjmp
)
6236 struct value
*arg_value
;
6238 /* If we set the longjmp breakpoint via a SystemTap probe,
6239 then use it to extract the arguments. The destination PC
6240 is the third argument to the probe. */
6241 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6244 jmp_buf_pc
= value_as_address (arg_value
);
6245 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6247 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6248 || !gdbarch_get_longjmp_target (gdbarch
,
6249 frame
, &jmp_buf_pc
))
6252 fprintf_unfiltered (gdb_stdlog
,
6253 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6254 "(!gdbarch_get_longjmp_target)\n");
6259 /* Insert a breakpoint at resume address. */
6260 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6263 check_exception_resume (ecs
, frame
);
6267 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6269 struct frame_info
*init_frame
;
6271 /* There are several cases to consider.
6273 1. The initiating frame no longer exists. In this case we
6274 must stop, because the exception or longjmp has gone too
6277 2. The initiating frame exists, and is the same as the
6278 current frame. We stop, because the exception or longjmp
6281 3. The initiating frame exists and is different from the
6282 current frame. This means the exception or longjmp has
6283 been caught beneath the initiating frame, so keep going.
6285 4. longjmp breakpoint has been placed just to protect
6286 against stale dummy frames and user is not interested in
6287 stopping around longjmps. */
6290 fprintf_unfiltered (gdb_stdlog
,
6291 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6293 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6295 delete_exception_resume_breakpoint (ecs
->event_thread
);
6297 if (what
.is_longjmp
)
6299 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6301 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6309 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6313 struct frame_id current_id
6314 = get_frame_id (get_current_frame ());
6315 if (frame_id_eq (current_id
,
6316 ecs
->event_thread
->initiating_frame
))
6318 /* Case 2. Fall through. */
6328 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6330 delete_step_resume_breakpoint (ecs
->event_thread
);
6332 end_stepping_range (ecs
);
6336 case BPSTAT_WHAT_SINGLE
:
6338 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6339 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6340 /* Still need to check other stuff, at least the case where we
6341 are stepping and step out of the right range. */
6344 case BPSTAT_WHAT_STEP_RESUME
:
6346 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6348 delete_step_resume_breakpoint (ecs
->event_thread
);
6349 if (ecs
->event_thread
->control
.proceed_to_finish
6350 && execution_direction
== EXEC_REVERSE
)
6352 struct thread_info
*tp
= ecs
->event_thread
;
6354 /* We are finishing a function in reverse, and just hit the
6355 step-resume breakpoint at the start address of the
6356 function, and we're almost there -- just need to back up
6357 by one more single-step, which should take us back to the
6359 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6363 fill_in_stop_func (gdbarch
, ecs
);
6364 if (stop_pc
== ecs
->stop_func_start
6365 && execution_direction
== EXEC_REVERSE
)
6367 /* We are stepping over a function call in reverse, and just
6368 hit the step-resume breakpoint at the start address of
6369 the function. Go back to single-stepping, which should
6370 take us back to the function call. */
6371 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6377 case BPSTAT_WHAT_STOP_NOISY
:
6379 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6380 stop_print_frame
= 1;
6382 /* Assume the thread stopped for a breapoint. We'll still check
6383 whether a/the breakpoint is there when the thread is next
6385 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6390 case BPSTAT_WHAT_STOP_SILENT
:
6392 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6393 stop_print_frame
= 0;
6395 /* Assume the thread stopped for a breapoint. We'll still check
6396 whether a/the breakpoint is there when the thread is next
6398 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6402 case BPSTAT_WHAT_HP_STEP_RESUME
:
6404 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6406 delete_step_resume_breakpoint (ecs
->event_thread
);
6407 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6409 /* Back when the step-resume breakpoint was inserted, we
6410 were trying to single-step off a breakpoint. Go back to
6412 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6413 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6419 case BPSTAT_WHAT_KEEP_CHECKING
:
6423 /* If we stepped a permanent breakpoint and we had a high priority
6424 step-resume breakpoint for the address we stepped, but we didn't
6425 hit it, then we must have stepped into the signal handler. The
6426 step-resume was only necessary to catch the case of _not_
6427 stepping into the handler, so delete it, and fall through to
6428 checking whether the step finished. */
6429 if (ecs
->event_thread
->stepped_breakpoint
)
6431 struct breakpoint
*sr_bp
6432 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6435 && sr_bp
->loc
->permanent
6436 && sr_bp
->type
== bp_hp_step_resume
6437 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6440 fprintf_unfiltered (gdb_stdlog
,
6441 "infrun: stepped permanent breakpoint, stopped in "
6443 delete_step_resume_breakpoint (ecs
->event_thread
);
6444 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6448 /* We come here if we hit a breakpoint but should not stop for it.
6449 Possibly we also were stepping and should stop for that. So fall
6450 through and test for stepping. But, if not stepping, do not
6453 /* In all-stop mode, if we're currently stepping but have stopped in
6454 some other thread, we need to switch back to the stepped thread. */
6455 if (switch_back_to_stepped_thread (ecs
))
6458 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6461 fprintf_unfiltered (gdb_stdlog
,
6462 "infrun: step-resume breakpoint is inserted\n");
6464 /* Having a step-resume breakpoint overrides anything
6465 else having to do with stepping commands until
6466 that breakpoint is reached. */
6471 if (ecs
->event_thread
->control
.step_range_end
== 0)
6474 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6475 /* Likewise if we aren't even stepping. */
6480 /* Re-fetch current thread's frame in case the code above caused
6481 the frame cache to be re-initialized, making our FRAME variable
6482 a dangling pointer. */
6483 frame
= get_current_frame ();
6484 gdbarch
= get_frame_arch (frame
);
6485 fill_in_stop_func (gdbarch
, ecs
);
6487 /* If stepping through a line, keep going if still within it.
6489 Note that step_range_end is the address of the first instruction
6490 beyond the step range, and NOT the address of the last instruction
6493 Note also that during reverse execution, we may be stepping
6494 through a function epilogue and therefore must detect when
6495 the current-frame changes in the middle of a line. */
6497 if (pc_in_thread_step_range (stop_pc
, ecs
->event_thread
)
6498 && (execution_direction
!= EXEC_REVERSE
6499 || frame_id_eq (get_frame_id (frame
),
6500 ecs
->event_thread
->control
.step_frame_id
)))
6504 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6505 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6506 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6508 /* Tentatively re-enable range stepping; `resume' disables it if
6509 necessary (e.g., if we're stepping over a breakpoint or we
6510 have software watchpoints). */
6511 ecs
->event_thread
->control
.may_range_step
= 1;
6513 /* When stepping backward, stop at beginning of line range
6514 (unless it's the function entry point, in which case
6515 keep going back to the call point). */
6516 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6517 && stop_pc
!= ecs
->stop_func_start
6518 && execution_direction
== EXEC_REVERSE
)
6519 end_stepping_range (ecs
);
6526 /* We stepped out of the stepping range. */
6528 /* If we are stepping at the source level and entered the runtime
6529 loader dynamic symbol resolution code...
6531 EXEC_FORWARD: we keep on single stepping until we exit the run
6532 time loader code and reach the callee's address.
6534 EXEC_REVERSE: we've already executed the callee (backward), and
6535 the runtime loader code is handled just like any other
6536 undebuggable function call. Now we need only keep stepping
6537 backward through the trampoline code, and that's handled further
6538 down, so there is nothing for us to do here. */
6540 if (execution_direction
!= EXEC_REVERSE
6541 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6542 && in_solib_dynsym_resolve_code (stop_pc
))
6544 CORE_ADDR pc_after_resolver
=
6545 gdbarch_skip_solib_resolver (gdbarch
, stop_pc
);
6548 fprintf_unfiltered (gdb_stdlog
,
6549 "infrun: stepped into dynsym resolve code\n");
6551 if (pc_after_resolver
)
6553 /* Set up a step-resume breakpoint at the address
6554 indicated by SKIP_SOLIB_RESOLVER. */
6555 symtab_and_line sr_sal
;
6556 sr_sal
.pc
= pc_after_resolver
;
6557 sr_sal
.pspace
= get_frame_program_space (frame
);
6559 insert_step_resume_breakpoint_at_sal (gdbarch
,
6560 sr_sal
, null_frame_id
);
6567 if (ecs
->event_thread
->control
.step_range_end
!= 1
6568 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6569 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6570 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6573 fprintf_unfiltered (gdb_stdlog
,
6574 "infrun: stepped into signal trampoline\n");
6575 /* The inferior, while doing a "step" or "next", has ended up in
6576 a signal trampoline (either by a signal being delivered or by
6577 the signal handler returning). Just single-step until the
6578 inferior leaves the trampoline (either by calling the handler
6584 /* If we're in the return path from a shared library trampoline,
6585 we want to proceed through the trampoline when stepping. */
6586 /* macro/2012-04-25: This needs to come before the subroutine
6587 call check below as on some targets return trampolines look
6588 like subroutine calls (MIPS16 return thunks). */
6589 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6590 stop_pc
, ecs
->stop_func_name
)
6591 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6593 /* Determine where this trampoline returns. */
6594 CORE_ADDR real_stop_pc
;
6596 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6599 fprintf_unfiltered (gdb_stdlog
,
6600 "infrun: stepped into solib return tramp\n");
6602 /* Only proceed through if we know where it's going. */
6605 /* And put the step-breakpoint there and go until there. */
6606 symtab_and_line sr_sal
;
6607 sr_sal
.pc
= real_stop_pc
;
6608 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6609 sr_sal
.pspace
= get_frame_program_space (frame
);
6611 /* Do not specify what the fp should be when we stop since
6612 on some machines the prologue is where the new fp value
6614 insert_step_resume_breakpoint_at_sal (gdbarch
,
6615 sr_sal
, null_frame_id
);
6617 /* Restart without fiddling with the step ranges or
6624 /* Check for subroutine calls. The check for the current frame
6625 equalling the step ID is not necessary - the check of the
6626 previous frame's ID is sufficient - but it is a common case and
6627 cheaper than checking the previous frame's ID.
6629 NOTE: frame_id_eq will never report two invalid frame IDs as
6630 being equal, so to get into this block, both the current and
6631 previous frame must have valid frame IDs. */
6632 /* The outer_frame_id check is a heuristic to detect stepping
6633 through startup code. If we step over an instruction which
6634 sets the stack pointer from an invalid value to a valid value,
6635 we may detect that as a subroutine call from the mythical
6636 "outermost" function. This could be fixed by marking
6637 outermost frames as !stack_p,code_p,special_p. Then the
6638 initial outermost frame, before sp was valid, would
6639 have code_addr == &_start. See the comment in frame_id_eq
6641 if (!frame_id_eq (get_stack_frame_id (frame
),
6642 ecs
->event_thread
->control
.step_stack_frame_id
)
6643 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6644 ecs
->event_thread
->control
.step_stack_frame_id
)
6645 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6647 || (ecs
->event_thread
->control
.step_start_function
6648 != find_pc_function (stop_pc
)))))
6650 CORE_ADDR real_stop_pc
;
6653 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6655 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6657 /* I presume that step_over_calls is only 0 when we're
6658 supposed to be stepping at the assembly language level
6659 ("stepi"). Just stop. */
6660 /* And this works the same backward as frontward. MVS */
6661 end_stepping_range (ecs
);
6665 /* Reverse stepping through solib trampolines. */
6667 if (execution_direction
== EXEC_REVERSE
6668 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6669 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6670 || (ecs
->stop_func_start
== 0
6671 && in_solib_dynsym_resolve_code (stop_pc
))))
6673 /* Any solib trampoline code can be handled in reverse
6674 by simply continuing to single-step. We have already
6675 executed the solib function (backwards), and a few
6676 steps will take us back through the trampoline to the
6682 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6684 /* We're doing a "next".
6686 Normal (forward) execution: set a breakpoint at the
6687 callee's return address (the address at which the caller
6690 Reverse (backward) execution. set the step-resume
6691 breakpoint at the start of the function that we just
6692 stepped into (backwards), and continue to there. When we
6693 get there, we'll need to single-step back to the caller. */
6695 if (execution_direction
== EXEC_REVERSE
)
6697 /* If we're already at the start of the function, we've either
6698 just stepped backward into a single instruction function,
6699 or stepped back out of a signal handler to the first instruction
6700 of the function. Just keep going, which will single-step back
6702 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6704 /* Normal function call return (static or dynamic). */
6705 symtab_and_line sr_sal
;
6706 sr_sal
.pc
= ecs
->stop_func_start
;
6707 sr_sal
.pspace
= get_frame_program_space (frame
);
6708 insert_step_resume_breakpoint_at_sal (gdbarch
,
6709 sr_sal
, null_frame_id
);
6713 insert_step_resume_breakpoint_at_caller (frame
);
6719 /* If we are in a function call trampoline (a stub between the
6720 calling routine and the real function), locate the real
6721 function. That's what tells us (a) whether we want to step
6722 into it at all, and (b) what prologue we want to run to the
6723 end of, if we do step into it. */
6724 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6725 if (real_stop_pc
== 0)
6726 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6727 if (real_stop_pc
!= 0)
6728 ecs
->stop_func_start
= real_stop_pc
;
6730 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6732 symtab_and_line sr_sal
;
6733 sr_sal
.pc
= ecs
->stop_func_start
;
6734 sr_sal
.pspace
= get_frame_program_space (frame
);
6736 insert_step_resume_breakpoint_at_sal (gdbarch
,
6737 sr_sal
, null_frame_id
);
6742 /* If we have line number information for the function we are
6743 thinking of stepping into and the function isn't on the skip
6746 If there are several symtabs at that PC (e.g. with include
6747 files), just want to know whether *any* of them have line
6748 numbers. find_pc_line handles this. */
6750 struct symtab_and_line tmp_sal
;
6752 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6753 if (tmp_sal
.line
!= 0
6754 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6757 if (execution_direction
== EXEC_REVERSE
)
6758 handle_step_into_function_backward (gdbarch
, ecs
);
6760 handle_step_into_function (gdbarch
, ecs
);
6765 /* If we have no line number and the step-stop-if-no-debug is
6766 set, we stop the step so that the user has a chance to switch
6767 in assembly mode. */
6768 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6769 && step_stop_if_no_debug
)
6771 end_stepping_range (ecs
);
6775 if (execution_direction
== EXEC_REVERSE
)
6777 /* If we're already at the start of the function, we've either just
6778 stepped backward into a single instruction function without line
6779 number info, or stepped back out of a signal handler to the first
6780 instruction of the function without line number info. Just keep
6781 going, which will single-step back to the caller. */
6782 if (ecs
->stop_func_start
!= stop_pc
)
6784 /* Set a breakpoint at callee's start address.
6785 From there we can step once and be back in the caller. */
6786 symtab_and_line sr_sal
;
6787 sr_sal
.pc
= ecs
->stop_func_start
;
6788 sr_sal
.pspace
= get_frame_program_space (frame
);
6789 insert_step_resume_breakpoint_at_sal (gdbarch
,
6790 sr_sal
, null_frame_id
);
6794 /* Set a breakpoint at callee's return address (the address
6795 at which the caller will resume). */
6796 insert_step_resume_breakpoint_at_caller (frame
);
6802 /* Reverse stepping through solib trampolines. */
6804 if (execution_direction
== EXEC_REVERSE
6805 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6807 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6808 || (ecs
->stop_func_start
== 0
6809 && in_solib_dynsym_resolve_code (stop_pc
)))
6811 /* Any solib trampoline code can be handled in reverse
6812 by simply continuing to single-step. We have already
6813 executed the solib function (backwards), and a few
6814 steps will take us back through the trampoline to the
6819 else if (in_solib_dynsym_resolve_code (stop_pc
))
6821 /* Stepped backward into the solib dynsym resolver.
6822 Set a breakpoint at its start and continue, then
6823 one more step will take us out. */
6824 symtab_and_line sr_sal
;
6825 sr_sal
.pc
= ecs
->stop_func_start
;
6826 sr_sal
.pspace
= get_frame_program_space (frame
);
6827 insert_step_resume_breakpoint_at_sal (gdbarch
,
6828 sr_sal
, null_frame_id
);
6834 stop_pc_sal
= find_pc_line (stop_pc
, 0);
6836 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6837 the trampoline processing logic, however, there are some trampolines
6838 that have no names, so we should do trampoline handling first. */
6839 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6840 && ecs
->stop_func_name
== NULL
6841 && stop_pc_sal
.line
== 0)
6844 fprintf_unfiltered (gdb_stdlog
,
6845 "infrun: stepped into undebuggable function\n");
6847 /* The inferior just stepped into, or returned to, an
6848 undebuggable function (where there is no debugging information
6849 and no line number corresponding to the address where the
6850 inferior stopped). Since we want to skip this kind of code,
6851 we keep going until the inferior returns from this
6852 function - unless the user has asked us not to (via
6853 set step-mode) or we no longer know how to get back
6854 to the call site. */
6855 if (step_stop_if_no_debug
6856 || !frame_id_p (frame_unwind_caller_id (frame
)))
6858 /* If we have no line number and the step-stop-if-no-debug
6859 is set, we stop the step so that the user has a chance to
6860 switch in assembly mode. */
6861 end_stepping_range (ecs
);
6866 /* Set a breakpoint at callee's return address (the address
6867 at which the caller will resume). */
6868 insert_step_resume_breakpoint_at_caller (frame
);
6874 if (ecs
->event_thread
->control
.step_range_end
== 1)
6876 /* It is stepi or nexti. We always want to stop stepping after
6879 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
6880 end_stepping_range (ecs
);
6884 if (stop_pc_sal
.line
== 0)
6886 /* We have no line number information. That means to stop
6887 stepping (does this always happen right after one instruction,
6888 when we do "s" in a function with no line numbers,
6889 or can this happen as a result of a return or longjmp?). */
6891 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
6892 end_stepping_range (ecs
);
6896 /* Look for "calls" to inlined functions, part one. If the inline
6897 frame machinery detected some skipped call sites, we have entered
6898 a new inline function. */
6900 if (frame_id_eq (get_frame_id (get_current_frame ()),
6901 ecs
->event_thread
->control
.step_frame_id
)
6902 && inline_skipped_frames (ecs
->ptid
))
6905 fprintf_unfiltered (gdb_stdlog
,
6906 "infrun: stepped into inlined function\n");
6908 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6910 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6912 /* For "step", we're going to stop. But if the call site
6913 for this inlined function is on the same source line as
6914 we were previously stepping, go down into the function
6915 first. Otherwise stop at the call site. */
6917 if (call_sal
.line
== ecs
->event_thread
->current_line
6918 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6919 step_into_inline_frame (ecs
->ptid
);
6921 end_stepping_range (ecs
);
6926 /* For "next", we should stop at the call site if it is on a
6927 different source line. Otherwise continue through the
6928 inlined function. */
6929 if (call_sal
.line
== ecs
->event_thread
->current_line
6930 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6933 end_stepping_range (ecs
);
6938 /* Look for "calls" to inlined functions, part two. If we are still
6939 in the same real function we were stepping through, but we have
6940 to go further up to find the exact frame ID, we are stepping
6941 through a more inlined call beyond its call site. */
6943 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6944 && !frame_id_eq (get_frame_id (get_current_frame ()),
6945 ecs
->event_thread
->control
.step_frame_id
)
6946 && stepped_in_from (get_current_frame (),
6947 ecs
->event_thread
->control
.step_frame_id
))
6950 fprintf_unfiltered (gdb_stdlog
,
6951 "infrun: stepping through inlined function\n");
6953 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6956 end_stepping_range (ecs
);
6960 if ((stop_pc
== stop_pc_sal
.pc
)
6961 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
6962 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
6964 /* We are at the start of a different line. So stop. Note that
6965 we don't stop if we step into the middle of a different line.
6966 That is said to make things like for (;;) statements work
6969 fprintf_unfiltered (gdb_stdlog
,
6970 "infrun: stepped to a different line\n");
6971 end_stepping_range (ecs
);
6975 /* We aren't done stepping.
6977 Optimize by setting the stepping range to the line.
6978 (We might not be in the original line, but if we entered a
6979 new line in mid-statement, we continue stepping. This makes
6980 things like for(;;) statements work better.) */
6982 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
6983 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
6984 ecs
->event_thread
->control
.may_range_step
= 1;
6985 set_step_info (frame
, stop_pc_sal
);
6988 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
6992 /* In all-stop mode, if we're currently stepping but have stopped in
6993 some other thread, we may need to switch back to the stepped
6994 thread. Returns true we set the inferior running, false if we left
6995 it stopped (and the event needs further processing). */
6998 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7000 if (!target_is_non_stop_p ())
7002 struct thread_info
*tp
;
7003 struct thread_info
*stepping_thread
;
7005 /* If any thread is blocked on some internal breakpoint, and we
7006 simply need to step over that breakpoint to get it going
7007 again, do that first. */
7009 /* However, if we see an event for the stepping thread, then we
7010 know all other threads have been moved past their breakpoints
7011 already. Let the caller check whether the step is finished,
7012 etc., before deciding to move it past a breakpoint. */
7013 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7016 /* Check if the current thread is blocked on an incomplete
7017 step-over, interrupted by a random signal. */
7018 if (ecs
->event_thread
->control
.trap_expected
7019 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7023 fprintf_unfiltered (gdb_stdlog
,
7024 "infrun: need to finish step-over of [%s]\n",
7025 target_pid_to_str (ecs
->event_thread
->ptid
));
7031 /* Check if the current thread is blocked by a single-step
7032 breakpoint of another thread. */
7033 if (ecs
->hit_singlestep_breakpoint
)
7037 fprintf_unfiltered (gdb_stdlog
,
7038 "infrun: need to step [%s] over single-step "
7040 target_pid_to_str (ecs
->ptid
));
7046 /* If this thread needs yet another step-over (e.g., stepping
7047 through a delay slot), do it first before moving on to
7049 if (thread_still_needs_step_over (ecs
->event_thread
))
7053 fprintf_unfiltered (gdb_stdlog
,
7054 "infrun: thread [%s] still needs step-over\n",
7055 target_pid_to_str (ecs
->event_thread
->ptid
));
7061 /* If scheduler locking applies even if not stepping, there's no
7062 need to walk over threads. Above we've checked whether the
7063 current thread is stepping. If some other thread not the
7064 event thread is stepping, then it must be that scheduler
7065 locking is not in effect. */
7066 if (schedlock_applies (ecs
->event_thread
))
7069 /* Otherwise, we no longer expect a trap in the current thread.
7070 Clear the trap_expected flag before switching back -- this is
7071 what keep_going does as well, if we call it. */
7072 ecs
->event_thread
->control
.trap_expected
= 0;
7074 /* Likewise, clear the signal if it should not be passed. */
7075 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7076 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7078 /* Do all pending step-overs before actually proceeding with
7080 if (start_step_over ())
7082 prepare_to_wait (ecs
);
7086 /* Look for the stepping/nexting thread. */
7087 stepping_thread
= NULL
;
7089 ALL_NON_EXITED_THREADS (tp
)
7091 /* Ignore threads of processes the caller is not
7094 && ptid_get_pid (tp
->ptid
) != ptid_get_pid (ecs
->ptid
))
7097 /* When stepping over a breakpoint, we lock all threads
7098 except the one that needs to move past the breakpoint.
7099 If a non-event thread has this set, the "incomplete
7100 step-over" check above should have caught it earlier. */
7101 if (tp
->control
.trap_expected
)
7103 internal_error (__FILE__
, __LINE__
,
7104 "[%s] has inconsistent state: "
7105 "trap_expected=%d\n",
7106 target_pid_to_str (tp
->ptid
),
7107 tp
->control
.trap_expected
);
7110 /* Did we find the stepping thread? */
7111 if (tp
->control
.step_range_end
)
7113 /* Yep. There should only one though. */
7114 gdb_assert (stepping_thread
== NULL
);
7116 /* The event thread is handled at the top, before we
7118 gdb_assert (tp
!= ecs
->event_thread
);
7120 /* If some thread other than the event thread is
7121 stepping, then scheduler locking can't be in effect,
7122 otherwise we wouldn't have resumed the current event
7123 thread in the first place. */
7124 gdb_assert (!schedlock_applies (tp
));
7126 stepping_thread
= tp
;
7130 if (stepping_thread
!= NULL
)
7133 fprintf_unfiltered (gdb_stdlog
,
7134 "infrun: switching back to stepped thread\n");
7136 if (keep_going_stepped_thread (stepping_thread
))
7138 prepare_to_wait (ecs
);
7147 /* Set a previously stepped thread back to stepping. Returns true on
7148 success, false if the resume is not possible (e.g., the thread
7152 keep_going_stepped_thread (struct thread_info
*tp
)
7154 struct frame_info
*frame
;
7155 struct execution_control_state ecss
;
7156 struct execution_control_state
*ecs
= &ecss
;
7158 /* If the stepping thread exited, then don't try to switch back and
7159 resume it, which could fail in several different ways depending
7160 on the target. Instead, just keep going.
7162 We can find a stepping dead thread in the thread list in two
7165 - The target supports thread exit events, and when the target
7166 tries to delete the thread from the thread list, inferior_ptid
7167 pointed at the exiting thread. In such case, calling
7168 delete_thread does not really remove the thread from the list;
7169 instead, the thread is left listed, with 'exited' state.
7171 - The target's debug interface does not support thread exit
7172 events, and so we have no idea whatsoever if the previously
7173 stepping thread is still alive. For that reason, we need to
7174 synchronously query the target now. */
7176 if (is_exited (tp
->ptid
)
7177 || !target_thread_alive (tp
->ptid
))
7180 fprintf_unfiltered (gdb_stdlog
,
7181 "infrun: not resuming previously "
7182 "stepped thread, it has vanished\n");
7184 delete_thread (tp
->ptid
);
7189 fprintf_unfiltered (gdb_stdlog
,
7190 "infrun: resuming previously stepped thread\n");
7192 reset_ecs (ecs
, tp
);
7193 switch_to_thread (tp
->ptid
);
7195 stop_pc
= regcache_read_pc (get_thread_regcache (tp
->ptid
));
7196 frame
= get_current_frame ();
7198 /* If the PC of the thread we were trying to single-step has
7199 changed, then that thread has trapped or been signaled, but the
7200 event has not been reported to GDB yet. Re-poll the target
7201 looking for this particular thread's event (i.e. temporarily
7202 enable schedlock) by:
7204 - setting a break at the current PC
7205 - resuming that particular thread, only (by setting trap
7208 This prevents us continuously moving the single-step breakpoint
7209 forward, one instruction at a time, overstepping. */
7211 if (stop_pc
!= tp
->prev_pc
)
7216 fprintf_unfiltered (gdb_stdlog
,
7217 "infrun: expected thread advanced also (%s -> %s)\n",
7218 paddress (target_gdbarch (), tp
->prev_pc
),
7219 paddress (target_gdbarch (), stop_pc
));
7221 /* Clear the info of the previous step-over, as it's no longer
7222 valid (if the thread was trying to step over a breakpoint, it
7223 has already succeeded). It's what keep_going would do too,
7224 if we called it. Do this before trying to insert the sss
7225 breakpoint, otherwise if we were previously trying to step
7226 over this exact address in another thread, the breakpoint is
7228 clear_step_over_info ();
7229 tp
->control
.trap_expected
= 0;
7231 insert_single_step_breakpoint (get_frame_arch (frame
),
7232 get_frame_address_space (frame
),
7236 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7237 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7242 fprintf_unfiltered (gdb_stdlog
,
7243 "infrun: expected thread still hasn't advanced\n");
7245 keep_going_pass_signal (ecs
);
7250 /* Is thread TP in the middle of (software or hardware)
7251 single-stepping? (Note the result of this function must never be
7252 passed directly as target_resume's STEP parameter.) */
7255 currently_stepping (struct thread_info
*tp
)
7257 return ((tp
->control
.step_range_end
7258 && tp
->control
.step_resume_breakpoint
== NULL
)
7259 || tp
->control
.trap_expected
7260 || tp
->stepped_breakpoint
7261 || bpstat_should_step ());
7264 /* Inferior has stepped into a subroutine call with source code that
7265 we should not step over. Do step to the first line of code in
7269 handle_step_into_function (struct gdbarch
*gdbarch
,
7270 struct execution_control_state
*ecs
)
7272 fill_in_stop_func (gdbarch
, ecs
);
7274 compunit_symtab
*cust
= find_pc_compunit_symtab (stop_pc
);
7275 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7276 ecs
->stop_func_start
7277 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7279 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7280 /* Use the step_resume_break to step until the end of the prologue,
7281 even if that involves jumps (as it seems to on the vax under
7283 /* If the prologue ends in the middle of a source line, continue to
7284 the end of that source line (if it is still within the function).
7285 Otherwise, just go to end of prologue. */
7286 if (stop_func_sal
.end
7287 && stop_func_sal
.pc
!= ecs
->stop_func_start
7288 && stop_func_sal
.end
< ecs
->stop_func_end
)
7289 ecs
->stop_func_start
= stop_func_sal
.end
;
7291 /* Architectures which require breakpoint adjustment might not be able
7292 to place a breakpoint at the computed address. If so, the test
7293 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7294 ecs->stop_func_start to an address at which a breakpoint may be
7295 legitimately placed.
7297 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7298 made, GDB will enter an infinite loop when stepping through
7299 optimized code consisting of VLIW instructions which contain
7300 subinstructions corresponding to different source lines. On
7301 FR-V, it's not permitted to place a breakpoint on any but the
7302 first subinstruction of a VLIW instruction. When a breakpoint is
7303 set, GDB will adjust the breakpoint address to the beginning of
7304 the VLIW instruction. Thus, we need to make the corresponding
7305 adjustment here when computing the stop address. */
7307 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7309 ecs
->stop_func_start
7310 = gdbarch_adjust_breakpoint_address (gdbarch
,
7311 ecs
->stop_func_start
);
7314 if (ecs
->stop_func_start
== stop_pc
)
7316 /* We are already there: stop now. */
7317 end_stepping_range (ecs
);
7322 /* Put the step-breakpoint there and go until there. */
7323 symtab_and_line sr_sal
;
7324 sr_sal
.pc
= ecs
->stop_func_start
;
7325 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7326 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7328 /* Do not specify what the fp should be when we stop since on
7329 some machines the prologue is where the new fp value is
7331 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7333 /* And make sure stepping stops right away then. */
7334 ecs
->event_thread
->control
.step_range_end
7335 = ecs
->event_thread
->control
.step_range_start
;
7340 /* Inferior has stepped backward into a subroutine call with source
7341 code that we should not step over. Do step to the beginning of the
7342 last line of code in it. */
7345 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7346 struct execution_control_state
*ecs
)
7348 struct compunit_symtab
*cust
;
7349 struct symtab_and_line stop_func_sal
;
7351 fill_in_stop_func (gdbarch
, ecs
);
7353 cust
= find_pc_compunit_symtab (stop_pc
);
7354 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7355 ecs
->stop_func_start
7356 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7358 stop_func_sal
= find_pc_line (stop_pc
, 0);
7360 /* OK, we're just going to keep stepping here. */
7361 if (stop_func_sal
.pc
== stop_pc
)
7363 /* We're there already. Just stop stepping now. */
7364 end_stepping_range (ecs
);
7368 /* Else just reset the step range and keep going.
7369 No step-resume breakpoint, they don't work for
7370 epilogues, which can have multiple entry paths. */
7371 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7372 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7378 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7379 This is used to both functions and to skip over code. */
7382 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7383 struct symtab_and_line sr_sal
,
7384 struct frame_id sr_id
,
7385 enum bptype sr_type
)
7387 /* There should never be more than one step-resume or longjmp-resume
7388 breakpoint per thread, so we should never be setting a new
7389 step_resume_breakpoint when one is already active. */
7390 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7391 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7394 fprintf_unfiltered (gdb_stdlog
,
7395 "infrun: inserting step-resume breakpoint at %s\n",
7396 paddress (gdbarch
, sr_sal
.pc
));
7398 inferior_thread ()->control
.step_resume_breakpoint
7399 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7403 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7404 struct symtab_and_line sr_sal
,
7405 struct frame_id sr_id
)
7407 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7412 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7413 This is used to skip a potential signal handler.
7415 This is called with the interrupted function's frame. The signal
7416 handler, when it returns, will resume the interrupted function at
7420 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7422 gdb_assert (return_frame
!= NULL
);
7424 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7426 symtab_and_line sr_sal
;
7427 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7428 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7429 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7431 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7432 get_stack_frame_id (return_frame
),
7436 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7437 is used to skip a function after stepping into it (for "next" or if
7438 the called function has no debugging information).
7440 The current function has almost always been reached by single
7441 stepping a call or return instruction. NEXT_FRAME belongs to the
7442 current function, and the breakpoint will be set at the caller's
7445 This is a separate function rather than reusing
7446 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7447 get_prev_frame, which may stop prematurely (see the implementation
7448 of frame_unwind_caller_id for an example). */
7451 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7453 /* We shouldn't have gotten here if we don't know where the call site
7455 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7457 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7459 symtab_and_line sr_sal
;
7460 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7461 frame_unwind_caller_pc (next_frame
));
7462 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7463 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7465 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7466 frame_unwind_caller_id (next_frame
));
7469 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7470 new breakpoint at the target of a jmp_buf. The handling of
7471 longjmp-resume uses the same mechanisms used for handling
7472 "step-resume" breakpoints. */
7475 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7477 /* There should never be more than one longjmp-resume breakpoint per
7478 thread, so we should never be setting a new
7479 longjmp_resume_breakpoint when one is already active. */
7480 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7483 fprintf_unfiltered (gdb_stdlog
,
7484 "infrun: inserting longjmp-resume breakpoint at %s\n",
7485 paddress (gdbarch
, pc
));
7487 inferior_thread ()->control
.exception_resume_breakpoint
=
7488 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7491 /* Insert an exception resume breakpoint. TP is the thread throwing
7492 the exception. The block B is the block of the unwinder debug hook
7493 function. FRAME is the frame corresponding to the call to this
7494 function. SYM is the symbol of the function argument holding the
7495 target PC of the exception. */
7498 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7499 const struct block
*b
,
7500 struct frame_info
*frame
,
7505 struct block_symbol vsym
;
7506 struct value
*value
;
7508 struct breakpoint
*bp
;
7510 vsym
= lookup_symbol (SYMBOL_LINKAGE_NAME (sym
), b
, VAR_DOMAIN
, NULL
);
7511 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7512 /* If the value was optimized out, revert to the old behavior. */
7513 if (! value_optimized_out (value
))
7515 handler
= value_as_address (value
);
7518 fprintf_unfiltered (gdb_stdlog
,
7519 "infrun: exception resume at %lx\n",
7520 (unsigned long) handler
);
7522 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7524 bp_exception_resume
).release ();
7526 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7529 bp
->thread
= tp
->global_num
;
7530 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7533 CATCH (e
, RETURN_MASK_ERROR
)
7535 /* We want to ignore errors here. */
7540 /* A helper for check_exception_resume that sets an
7541 exception-breakpoint based on a SystemTap probe. */
7544 insert_exception_resume_from_probe (struct thread_info
*tp
,
7545 const struct bound_probe
*probe
,
7546 struct frame_info
*frame
)
7548 struct value
*arg_value
;
7550 struct breakpoint
*bp
;
7552 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7556 handler
= value_as_address (arg_value
);
7559 fprintf_unfiltered (gdb_stdlog
,
7560 "infrun: exception resume at %s\n",
7561 paddress (get_objfile_arch (probe
->objfile
),
7564 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7565 handler
, bp_exception_resume
).release ();
7566 bp
->thread
= tp
->global_num
;
7567 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7570 /* This is called when an exception has been intercepted. Check to
7571 see whether the exception's destination is of interest, and if so,
7572 set an exception resume breakpoint there. */
7575 check_exception_resume (struct execution_control_state
*ecs
,
7576 struct frame_info
*frame
)
7578 struct bound_probe probe
;
7579 struct symbol
*func
;
7581 /* First see if this exception unwinding breakpoint was set via a
7582 SystemTap probe point. If so, the probe has two arguments: the
7583 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7584 set a breakpoint there. */
7585 probe
= find_probe_by_pc (get_frame_pc (frame
));
7588 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7592 func
= get_frame_function (frame
);
7598 const struct block
*b
;
7599 struct block_iterator iter
;
7603 /* The exception breakpoint is a thread-specific breakpoint on
7604 the unwinder's debug hook, declared as:
7606 void _Unwind_DebugHook (void *cfa, void *handler);
7608 The CFA argument indicates the frame to which control is
7609 about to be transferred. HANDLER is the destination PC.
7611 We ignore the CFA and set a temporary breakpoint at HANDLER.
7612 This is not extremely efficient but it avoids issues in gdb
7613 with computing the DWARF CFA, and it also works even in weird
7614 cases such as throwing an exception from inside a signal
7617 b
= SYMBOL_BLOCK_VALUE (func
);
7618 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7620 if (!SYMBOL_IS_ARGUMENT (sym
))
7627 insert_exception_resume_breakpoint (ecs
->event_thread
,
7633 CATCH (e
, RETURN_MASK_ERROR
)
7640 stop_waiting (struct execution_control_state
*ecs
)
7643 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7645 /* Let callers know we don't want to wait for the inferior anymore. */
7646 ecs
->wait_some_more
= 0;
7648 /* If all-stop, but the target is always in non-stop mode, stop all
7649 threads now that we're presenting the stop to the user. */
7650 if (!non_stop
&& target_is_non_stop_p ())
7651 stop_all_threads ();
7654 /* Like keep_going, but passes the signal to the inferior, even if the
7655 signal is set to nopass. */
7658 keep_going_pass_signal (struct execution_control_state
*ecs
)
7660 /* Make sure normal_stop is called if we get a QUIT handled before
7662 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
7664 gdb_assert (ptid_equal (ecs
->event_thread
->ptid
, inferior_ptid
));
7665 gdb_assert (!ecs
->event_thread
->resumed
);
7667 /* Save the pc before execution, to compare with pc after stop. */
7668 ecs
->event_thread
->prev_pc
7669 = regcache_read_pc (get_thread_regcache (ecs
->ptid
));
7671 if (ecs
->event_thread
->control
.trap_expected
)
7673 struct thread_info
*tp
= ecs
->event_thread
;
7676 fprintf_unfiltered (gdb_stdlog
,
7677 "infrun: %s has trap_expected set, "
7678 "resuming to collect trap\n",
7679 target_pid_to_str (tp
->ptid
));
7681 /* We haven't yet gotten our trap, and either: intercepted a
7682 non-signal event (e.g., a fork); or took a signal which we
7683 are supposed to pass through to the inferior. Simply
7685 discard_cleanups (old_cleanups
);
7686 resume (ecs
->event_thread
->suspend
.stop_signal
);
7688 else if (step_over_info_valid_p ())
7690 /* Another thread is stepping over a breakpoint in-line. If
7691 this thread needs a step-over too, queue the request. In
7692 either case, this resume must be deferred for later. */
7693 struct thread_info
*tp
= ecs
->event_thread
;
7695 if (ecs
->hit_singlestep_breakpoint
7696 || thread_still_needs_step_over (tp
))
7699 fprintf_unfiltered (gdb_stdlog
,
7700 "infrun: step-over already in progress: "
7701 "step-over for %s deferred\n",
7702 target_pid_to_str (tp
->ptid
));
7703 thread_step_over_chain_enqueue (tp
);
7708 fprintf_unfiltered (gdb_stdlog
,
7709 "infrun: step-over in progress: "
7710 "resume of %s deferred\n",
7711 target_pid_to_str (tp
->ptid
));
7714 discard_cleanups (old_cleanups
);
7718 struct regcache
*regcache
= get_current_regcache ();
7721 step_over_what step_what
;
7723 /* Either the trap was not expected, but we are continuing
7724 anyway (if we got a signal, the user asked it be passed to
7727 We got our expected trap, but decided we should resume from
7730 We're going to run this baby now!
7732 Note that insert_breakpoints won't try to re-insert
7733 already inserted breakpoints. Therefore, we don't
7734 care if breakpoints were already inserted, or not. */
7736 /* If we need to step over a breakpoint, and we're not using
7737 displaced stepping to do so, insert all breakpoints
7738 (watchpoints, etc.) but the one we're stepping over, step one
7739 instruction, and then re-insert the breakpoint when that step
7742 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7744 remove_bp
= (ecs
->hit_singlestep_breakpoint
7745 || (step_what
& STEP_OVER_BREAKPOINT
));
7746 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7748 /* We can't use displaced stepping if we need to step past a
7749 watchpoint. The instruction copied to the scratch pad would
7750 still trigger the watchpoint. */
7752 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7754 set_step_over_info (regcache
->aspace (),
7755 regcache_read_pc (regcache
), remove_wps
,
7756 ecs
->event_thread
->global_num
);
7758 else if (remove_wps
)
7759 set_step_over_info (NULL
, 0, remove_wps
, -1);
7761 /* If we now need to do an in-line step-over, we need to stop
7762 all other threads. Note this must be done before
7763 insert_breakpoints below, because that removes the breakpoint
7764 we're about to step over, otherwise other threads could miss
7766 if (step_over_info_valid_p () && target_is_non_stop_p ())
7767 stop_all_threads ();
7769 /* Stop stepping if inserting breakpoints fails. */
7772 insert_breakpoints ();
7774 CATCH (e
, RETURN_MASK_ERROR
)
7776 exception_print (gdb_stderr
, e
);
7778 discard_cleanups (old_cleanups
);
7783 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7785 discard_cleanups (old_cleanups
);
7786 resume (ecs
->event_thread
->suspend
.stop_signal
);
7789 prepare_to_wait (ecs
);
7792 /* Called when we should continue running the inferior, because the
7793 current event doesn't cause a user visible stop. This does the
7794 resuming part; waiting for the next event is done elsewhere. */
7797 keep_going (struct execution_control_state
*ecs
)
7799 if (ecs
->event_thread
->control
.trap_expected
7800 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7801 ecs
->event_thread
->control
.trap_expected
= 0;
7803 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7804 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7805 keep_going_pass_signal (ecs
);
7808 /* This function normally comes after a resume, before
7809 handle_inferior_event exits. It takes care of any last bits of
7810 housekeeping, and sets the all-important wait_some_more flag. */
7813 prepare_to_wait (struct execution_control_state
*ecs
)
7816 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7818 ecs
->wait_some_more
= 1;
7820 if (!target_is_async_p ())
7821 mark_infrun_async_event_handler ();
7824 /* We are done with the step range of a step/next/si/ni command.
7825 Called once for each n of a "step n" operation. */
7828 end_stepping_range (struct execution_control_state
*ecs
)
7830 ecs
->event_thread
->control
.stop_step
= 1;
7834 /* Several print_*_reason functions to print why the inferior has stopped.
7835 We always print something when the inferior exits, or receives a signal.
7836 The rest of the cases are dealt with later on in normal_stop and
7837 print_it_typical. Ideally there should be a call to one of these
7838 print_*_reason functions functions from handle_inferior_event each time
7839 stop_waiting is called.
7841 Note that we don't call these directly, instead we delegate that to
7842 the interpreters, through observers. Interpreters then call these
7843 with whatever uiout is right. */
7846 print_end_stepping_range_reason (struct ui_out
*uiout
)
7848 /* For CLI-like interpreters, print nothing. */
7850 if (uiout
->is_mi_like_p ())
7852 uiout
->field_string ("reason",
7853 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7858 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7860 annotate_signalled ();
7861 if (uiout
->is_mi_like_p ())
7863 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7864 uiout
->text ("\nProgram terminated with signal ");
7865 annotate_signal_name ();
7866 uiout
->field_string ("signal-name",
7867 gdb_signal_to_name (siggnal
));
7868 annotate_signal_name_end ();
7870 annotate_signal_string ();
7871 uiout
->field_string ("signal-meaning",
7872 gdb_signal_to_string (siggnal
));
7873 annotate_signal_string_end ();
7874 uiout
->text (".\n");
7875 uiout
->text ("The program no longer exists.\n");
7879 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7881 struct inferior
*inf
= current_inferior ();
7882 const char *pidstr
= target_pid_to_str (pid_to_ptid (inf
->pid
));
7884 annotate_exited (exitstatus
);
7887 if (uiout
->is_mi_like_p ())
7888 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7889 uiout
->text ("[Inferior ");
7890 uiout
->text (plongest (inf
->num
));
7892 uiout
->text (pidstr
);
7893 uiout
->text (") exited with code ");
7894 uiout
->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus
);
7895 uiout
->text ("]\n");
7899 if (uiout
->is_mi_like_p ())
7901 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7902 uiout
->text ("[Inferior ");
7903 uiout
->text (plongest (inf
->num
));
7905 uiout
->text (pidstr
);
7906 uiout
->text (") exited normally]\n");
7910 /* Some targets/architectures can do extra processing/display of
7911 segmentation faults. E.g., Intel MPX boundary faults.
7912 Call the architecture dependent function to handle the fault. */
7915 handle_segmentation_fault (struct ui_out
*uiout
)
7917 struct regcache
*regcache
= get_current_regcache ();
7918 struct gdbarch
*gdbarch
= regcache
->arch ();
7920 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7921 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7925 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7927 struct thread_info
*thr
= inferior_thread ();
7931 if (uiout
->is_mi_like_p ())
7933 else if (show_thread_that_caused_stop ())
7937 uiout
->text ("\nThread ");
7938 uiout
->field_fmt ("thread-id", "%s", print_thread_id (thr
));
7940 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7943 uiout
->text (" \"");
7944 uiout
->field_fmt ("name", "%s", name
);
7949 uiout
->text ("\nProgram");
7951 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7952 uiout
->text (" stopped");
7955 uiout
->text (" received signal ");
7956 annotate_signal_name ();
7957 if (uiout
->is_mi_like_p ())
7959 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7960 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7961 annotate_signal_name_end ();
7963 annotate_signal_string ();
7964 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7966 if (siggnal
== GDB_SIGNAL_SEGV
)
7967 handle_segmentation_fault (uiout
);
7969 annotate_signal_string_end ();
7971 uiout
->text (".\n");
7975 print_no_history_reason (struct ui_out
*uiout
)
7977 uiout
->text ("\nNo more reverse-execution history.\n");
7980 /* Print current location without a level number, if we have changed
7981 functions or hit a breakpoint. Print source line if we have one.
7982 bpstat_print contains the logic deciding in detail what to print,
7983 based on the event(s) that just occurred. */
7986 print_stop_location (struct target_waitstatus
*ws
)
7989 enum print_what source_flag
;
7990 int do_frame_printing
= 1;
7991 struct thread_info
*tp
= inferior_thread ();
7993 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
7997 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7998 should) carry around the function and does (or should) use
7999 that when doing a frame comparison. */
8000 if (tp
->control
.stop_step
8001 && frame_id_eq (tp
->control
.step_frame_id
,
8002 get_frame_id (get_current_frame ()))
8003 && tp
->control
.step_start_function
== find_pc_function (stop_pc
))
8005 /* Finished step, just print source line. */
8006 source_flag
= SRC_LINE
;
8010 /* Print location and source line. */
8011 source_flag
= SRC_AND_LOC
;
8014 case PRINT_SRC_AND_LOC
:
8015 /* Print location and source line. */
8016 source_flag
= SRC_AND_LOC
;
8018 case PRINT_SRC_ONLY
:
8019 source_flag
= SRC_LINE
;
8022 /* Something bogus. */
8023 source_flag
= SRC_LINE
;
8024 do_frame_printing
= 0;
8027 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8030 /* The behavior of this routine with respect to the source
8032 SRC_LINE: Print only source line
8033 LOCATION: Print only location
8034 SRC_AND_LOC: Print location and source line. */
8035 if (do_frame_printing
)
8036 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8042 print_stop_event (struct ui_out
*uiout
)
8044 struct target_waitstatus last
;
8046 struct thread_info
*tp
;
8048 get_last_target_status (&last_ptid
, &last
);
8051 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8053 print_stop_location (&last
);
8055 /* Display the auto-display expressions. */
8059 tp
= inferior_thread ();
8060 if (tp
->thread_fsm
!= NULL
8061 && thread_fsm_finished_p (tp
->thread_fsm
))
8063 struct return_value_info
*rv
;
8065 rv
= thread_fsm_return_value (tp
->thread_fsm
);
8067 print_return_value (uiout
, rv
);
8074 maybe_remove_breakpoints (void)
8076 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8078 if (remove_breakpoints ())
8080 target_terminal::ours_for_output ();
8081 printf_filtered (_("Cannot remove breakpoints because "
8082 "program is no longer writable.\nFurther "
8083 "execution is probably impossible.\n"));
8088 /* The execution context that just caused a normal stop. */
8095 /* The event PTID. */
8099 /* If stopp for a thread event, this is the thread that caused the
8101 struct thread_info
*thread
;
8103 /* The inferior that caused the stop. */
8107 /* Returns a new stop context. If stopped for a thread event, this
8108 takes a strong reference to the thread. */
8110 static struct stop_context
*
8111 save_stop_context (void)
8113 struct stop_context
*sc
= XNEW (struct stop_context
);
8115 sc
->stop_id
= get_stop_id ();
8116 sc
->ptid
= inferior_ptid
;
8117 sc
->inf_num
= current_inferior ()->num
;
8119 if (!ptid_equal (inferior_ptid
, null_ptid
))
8121 /* Take a strong reference so that the thread can't be deleted
8123 sc
->thread
= inferior_thread ();
8124 sc
->thread
->incref ();
8132 /* Release a stop context previously created with save_stop_context.
8133 Releases the strong reference to the thread as well. */
8136 release_stop_context_cleanup (void *arg
)
8138 struct stop_context
*sc
= (struct stop_context
*) arg
;
8140 if (sc
->thread
!= NULL
)
8141 sc
->thread
->decref ();
8145 /* Return true if the current context no longer matches the saved stop
8149 stop_context_changed (struct stop_context
*prev
)
8151 if (!ptid_equal (prev
->ptid
, inferior_ptid
))
8153 if (prev
->inf_num
!= current_inferior ()->num
)
8155 if (prev
->thread
!= NULL
&& prev
->thread
->state
!= THREAD_STOPPED
)
8157 if (get_stop_id () != prev
->stop_id
)
8167 struct target_waitstatus last
;
8169 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
8172 get_last_target_status (&last_ptid
, &last
);
8176 /* If an exception is thrown from this point on, make sure to
8177 propagate GDB's knowledge of the executing state to the
8178 frontend/user running state. A QUIT is an easy exception to see
8179 here, so do this before any filtered output. */
8181 make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
8182 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8183 || last
.kind
== TARGET_WAITKIND_EXITED
)
8185 /* On some targets, we may still have live threads in the
8186 inferior when we get a process exit event. E.g., for
8187 "checkpoint", when the current checkpoint/fork exits,
8188 linux-fork.c automatically switches to another fork from
8189 within target_mourn_inferior. */
8190 if (!ptid_equal (inferior_ptid
, null_ptid
))
8192 pid_ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
8193 make_cleanup (finish_thread_state_cleanup
, &pid_ptid
);
8196 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8197 make_cleanup (finish_thread_state_cleanup
, &inferior_ptid
);
8199 /* As we're presenting a stop, and potentially removing breakpoints,
8200 update the thread list so we can tell whether there are threads
8201 running on the target. With target remote, for example, we can
8202 only learn about new threads when we explicitly update the thread
8203 list. Do this before notifying the interpreters about signal
8204 stops, end of stepping ranges, etc., so that the "new thread"
8205 output is emitted before e.g., "Program received signal FOO",
8206 instead of after. */
8207 update_thread_list ();
8209 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8210 observer_notify_signal_received (inferior_thread ()->suspend
.stop_signal
);
8212 /* As with the notification of thread events, we want to delay
8213 notifying the user that we've switched thread context until
8214 the inferior actually stops.
8216 There's no point in saying anything if the inferior has exited.
8217 Note that SIGNALLED here means "exited with a signal", not
8218 "received a signal".
8220 Also skip saying anything in non-stop mode. In that mode, as we
8221 don't want GDB to switch threads behind the user's back, to avoid
8222 races where the user is typing a command to apply to thread x,
8223 but GDB switches to thread y before the user finishes entering
8224 the command, fetch_inferior_event installs a cleanup to restore
8225 the current thread back to the thread the user had selected right
8226 after this event is handled, so we're not really switching, only
8227 informing of a stop. */
8229 && !ptid_equal (previous_inferior_ptid
, inferior_ptid
)
8230 && target_has_execution
8231 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8232 && last
.kind
!= TARGET_WAITKIND_EXITED
8233 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8235 SWITCH_THRU_ALL_UIS ()
8237 target_terminal::ours_for_output ();
8238 printf_filtered (_("[Switching to %s]\n"),
8239 target_pid_to_str (inferior_ptid
));
8240 annotate_thread_changed ();
8242 previous_inferior_ptid
= inferior_ptid
;
8245 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8247 SWITCH_THRU_ALL_UIS ()
8248 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8250 target_terminal::ours_for_output ();
8251 printf_filtered (_("No unwaited-for children left.\n"));
8255 /* Note: this depends on the update_thread_list call above. */
8256 maybe_remove_breakpoints ();
8258 /* If an auto-display called a function and that got a signal,
8259 delete that auto-display to avoid an infinite recursion. */
8261 if (stopped_by_random_signal
)
8262 disable_current_display ();
8264 SWITCH_THRU_ALL_UIS ()
8266 async_enable_stdin ();
8269 /* Let the user/frontend see the threads as stopped. */
8270 do_cleanups (old_chain
);
8272 /* Select innermost stack frame - i.e., current frame is frame 0,
8273 and current location is based on that. Handle the case where the
8274 dummy call is returning after being stopped. E.g. the dummy call
8275 previously hit a breakpoint. (If the dummy call returns
8276 normally, we won't reach here.) Do this before the stop hook is
8277 run, so that it doesn't get to see the temporary dummy frame,
8278 which is not where we'll present the stop. */
8279 if (has_stack_frames ())
8281 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8283 /* Pop the empty frame that contains the stack dummy. This
8284 also restores inferior state prior to the call (struct
8285 infcall_suspend_state). */
8286 struct frame_info
*frame
= get_current_frame ();
8288 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8290 /* frame_pop calls reinit_frame_cache as the last thing it
8291 does which means there's now no selected frame. */
8294 select_frame (get_current_frame ());
8296 /* Set the current source location. */
8297 set_current_sal_from_frame (get_current_frame ());
8300 /* Look up the hook_stop and run it (CLI internally handles problem
8301 of stop_command's pre-hook not existing). */
8302 if (stop_command
!= NULL
)
8304 struct stop_context
*saved_context
= save_stop_context ();
8305 struct cleanup
*old_chain
8306 = make_cleanup (release_stop_context_cleanup
, saved_context
);
8310 execute_cmd_pre_hook (stop_command
);
8312 CATCH (ex
, RETURN_MASK_ALL
)
8314 exception_fprintf (gdb_stderr
, ex
,
8315 "Error while running hook_stop:\n");
8319 /* If the stop hook resumes the target, then there's no point in
8320 trying to notify about the previous stop; its context is
8321 gone. Likewise if the command switches thread or inferior --
8322 the observers would print a stop for the wrong
8324 if (stop_context_changed (saved_context
))
8326 do_cleanups (old_chain
);
8329 do_cleanups (old_chain
);
8332 /* Notify observers about the stop. This is where the interpreters
8333 print the stop event. */
8334 if (!ptid_equal (inferior_ptid
, null_ptid
))
8335 observer_notify_normal_stop (inferior_thread ()->control
.stop_bpstat
,
8338 observer_notify_normal_stop (NULL
, stop_print_frame
);
8340 annotate_stopped ();
8342 if (target_has_execution
)
8344 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8345 && last
.kind
!= TARGET_WAITKIND_EXITED
)
8346 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8347 Delete any breakpoint that is to be deleted at the next stop. */
8348 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8351 /* Try to get rid of automatically added inferiors that are no
8352 longer needed. Keeping those around slows down things linearly.
8353 Note that this never removes the current inferior. */
8360 signal_stop_state (int signo
)
8362 return signal_stop
[signo
];
8366 signal_print_state (int signo
)
8368 return signal_print
[signo
];
8372 signal_pass_state (int signo
)
8374 return signal_program
[signo
];
8378 signal_cache_update (int signo
)
8382 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8383 signal_cache_update (signo
);
8388 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8389 && signal_print
[signo
] == 0
8390 && signal_program
[signo
] == 1
8391 && signal_catch
[signo
] == 0);
8395 signal_stop_update (int signo
, int state
)
8397 int ret
= signal_stop
[signo
];
8399 signal_stop
[signo
] = state
;
8400 signal_cache_update (signo
);
8405 signal_print_update (int signo
, int state
)
8407 int ret
= signal_print
[signo
];
8409 signal_print
[signo
] = state
;
8410 signal_cache_update (signo
);
8415 signal_pass_update (int signo
, int state
)
8417 int ret
= signal_program
[signo
];
8419 signal_program
[signo
] = state
;
8420 signal_cache_update (signo
);
8424 /* Update the global 'signal_catch' from INFO and notify the
8428 signal_catch_update (const unsigned int *info
)
8432 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8433 signal_catch
[i
] = info
[i
] > 0;
8434 signal_cache_update (-1);
8435 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
8439 sig_print_header (void)
8441 printf_filtered (_("Signal Stop\tPrint\tPass "
8442 "to program\tDescription\n"));
8446 sig_print_info (enum gdb_signal oursig
)
8448 const char *name
= gdb_signal_to_name (oursig
);
8449 int name_padding
= 13 - strlen (name
);
8451 if (name_padding
<= 0)
8454 printf_filtered ("%s", name
);
8455 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8456 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8457 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8458 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8459 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8462 /* Specify how various signals in the inferior should be handled. */
8465 handle_command (const char *args
, int from_tty
)
8467 int digits
, wordlen
;
8468 int sigfirst
, signum
, siglast
;
8469 enum gdb_signal oursig
;
8472 unsigned char *sigs
;
8476 error_no_arg (_("signal to handle"));
8479 /* Allocate and zero an array of flags for which signals to handle. */
8481 nsigs
= (int) GDB_SIGNAL_LAST
;
8482 sigs
= (unsigned char *) alloca (nsigs
);
8483 memset (sigs
, 0, nsigs
);
8485 /* Break the command line up into args. */
8487 gdb_argv
built_argv (args
);
8489 /* Walk through the args, looking for signal oursigs, signal names, and
8490 actions. Signal numbers and signal names may be interspersed with
8491 actions, with the actions being performed for all signals cumulatively
8492 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8494 for (char *arg
: built_argv
)
8496 wordlen
= strlen (arg
);
8497 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8501 sigfirst
= siglast
= -1;
8503 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8505 /* Apply action to all signals except those used by the
8506 debugger. Silently skip those. */
8509 siglast
= nsigs
- 1;
8511 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8513 SET_SIGS (nsigs
, sigs
, signal_stop
);
8514 SET_SIGS (nsigs
, sigs
, signal_print
);
8516 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8518 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8520 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8522 SET_SIGS (nsigs
, sigs
, signal_print
);
8524 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8526 SET_SIGS (nsigs
, sigs
, signal_program
);
8528 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8530 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8532 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8534 SET_SIGS (nsigs
, sigs
, signal_program
);
8536 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8538 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8539 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8541 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8543 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8545 else if (digits
> 0)
8547 /* It is numeric. The numeric signal refers to our own
8548 internal signal numbering from target.h, not to host/target
8549 signal number. This is a feature; users really should be
8550 using symbolic names anyway, and the common ones like
8551 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8553 sigfirst
= siglast
= (int)
8554 gdb_signal_from_command (atoi (arg
));
8555 if (arg
[digits
] == '-')
8558 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8560 if (sigfirst
> siglast
)
8562 /* Bet he didn't figure we'd think of this case... */
8570 oursig
= gdb_signal_from_name (arg
);
8571 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8573 sigfirst
= siglast
= (int) oursig
;
8577 /* Not a number and not a recognized flag word => complain. */
8578 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8582 /* If any signal numbers or symbol names were found, set flags for
8583 which signals to apply actions to. */
8585 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8587 switch ((enum gdb_signal
) signum
)
8589 case GDB_SIGNAL_TRAP
:
8590 case GDB_SIGNAL_INT
:
8591 if (!allsigs
&& !sigs
[signum
])
8593 if (query (_("%s is used by the debugger.\n\
8594 Are you sure you want to change it? "),
8595 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8601 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8602 gdb_flush (gdb_stdout
);
8607 case GDB_SIGNAL_DEFAULT
:
8608 case GDB_SIGNAL_UNKNOWN
:
8609 /* Make sure that "all" doesn't print these. */
8618 for (signum
= 0; signum
< nsigs
; signum
++)
8621 signal_cache_update (-1);
8622 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
8623 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
8627 /* Show the results. */
8628 sig_print_header ();
8629 for (; signum
< nsigs
; signum
++)
8631 sig_print_info ((enum gdb_signal
) signum
);
8638 /* Complete the "handle" command. */
8641 handle_completer (struct cmd_list_element
*ignore
,
8642 completion_tracker
&tracker
,
8643 const char *text
, const char *word
)
8645 static const char * const keywords
[] =
8659 signal_completer (ignore
, tracker
, text
, word
);
8660 complete_on_enum (tracker
, keywords
, word
, word
);
8664 gdb_signal_from_command (int num
)
8666 if (num
>= 1 && num
<= 15)
8667 return (enum gdb_signal
) num
;
8668 error (_("Only signals 1-15 are valid as numeric signals.\n\
8669 Use \"info signals\" for a list of symbolic signals."));
8672 /* Print current contents of the tables set by the handle command.
8673 It is possible we should just be printing signals actually used
8674 by the current target (but for things to work right when switching
8675 targets, all signals should be in the signal tables). */
8678 info_signals_command (const char *signum_exp
, int from_tty
)
8680 enum gdb_signal oursig
;
8682 sig_print_header ();
8686 /* First see if this is a symbol name. */
8687 oursig
= gdb_signal_from_name (signum_exp
);
8688 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8690 /* No, try numeric. */
8692 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8694 sig_print_info (oursig
);
8698 printf_filtered ("\n");
8699 /* These ugly casts brought to you by the native VAX compiler. */
8700 for (oursig
= GDB_SIGNAL_FIRST
;
8701 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8702 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8706 if (oursig
!= GDB_SIGNAL_UNKNOWN
8707 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8708 sig_print_info (oursig
);
8711 printf_filtered (_("\nUse the \"handle\" command "
8712 "to change these tables.\n"));
8715 /* The $_siginfo convenience variable is a bit special. We don't know
8716 for sure the type of the value until we actually have a chance to
8717 fetch the data. The type can change depending on gdbarch, so it is
8718 also dependent on which thread you have selected.
8720 1. making $_siginfo be an internalvar that creates a new value on
8723 2. making the value of $_siginfo be an lval_computed value. */
8725 /* This function implements the lval_computed support for reading a
8729 siginfo_value_read (struct value
*v
)
8731 LONGEST transferred
;
8733 /* If we can access registers, so can we access $_siginfo. Likewise
8735 validate_registers_access ();
8738 target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
,
8740 value_contents_all_raw (v
),
8742 TYPE_LENGTH (value_type (v
)));
8744 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8745 error (_("Unable to read siginfo"));
8748 /* This function implements the lval_computed support for writing a
8752 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8754 LONGEST transferred
;
8756 /* If we can access registers, so can we access $_siginfo. Likewise
8758 validate_registers_access ();
8760 transferred
= target_write (¤t_target
,
8761 TARGET_OBJECT_SIGNAL_INFO
,
8763 value_contents_all_raw (fromval
),
8765 TYPE_LENGTH (value_type (fromval
)));
8767 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8768 error (_("Unable to write siginfo"));
8771 static const struct lval_funcs siginfo_value_funcs
=
8777 /* Return a new value with the correct type for the siginfo object of
8778 the current thread using architecture GDBARCH. Return a void value
8779 if there's no object available. */
8781 static struct value
*
8782 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8785 if (target_has_stack
8786 && !ptid_equal (inferior_ptid
, null_ptid
)
8787 && gdbarch_get_siginfo_type_p (gdbarch
))
8789 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8791 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8794 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8798 /* infcall_suspend_state contains state about the program itself like its
8799 registers and any signal it received when it last stopped.
8800 This state must be restored regardless of how the inferior function call
8801 ends (either successfully, or after it hits a breakpoint or signal)
8802 if the program is to properly continue where it left off. */
8804 struct infcall_suspend_state
8806 struct thread_suspend_state thread_suspend
;
8810 struct regcache
*registers
;
8812 /* Format of SIGINFO_DATA or NULL if it is not present. */
8813 struct gdbarch
*siginfo_gdbarch
;
8815 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8816 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8817 content would be invalid. */
8818 gdb_byte
*siginfo_data
;
8821 struct infcall_suspend_state
*
8822 save_infcall_suspend_state (void)
8824 struct infcall_suspend_state
*inf_state
;
8825 struct thread_info
*tp
= inferior_thread ();
8826 struct regcache
*regcache
= get_current_regcache ();
8827 struct gdbarch
*gdbarch
= regcache
->arch ();
8828 gdb_byte
*siginfo_data
= NULL
;
8830 if (gdbarch_get_siginfo_type_p (gdbarch
))
8832 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8833 size_t len
= TYPE_LENGTH (type
);
8834 struct cleanup
*back_to
;
8836 siginfo_data
= (gdb_byte
*) xmalloc (len
);
8837 back_to
= make_cleanup (xfree
, siginfo_data
);
8839 if (target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8840 siginfo_data
, 0, len
) == len
)
8841 discard_cleanups (back_to
);
8844 /* Errors ignored. */
8845 do_cleanups (back_to
);
8846 siginfo_data
= NULL
;
8850 inf_state
= XCNEW (struct infcall_suspend_state
);
8854 inf_state
->siginfo_gdbarch
= gdbarch
;
8855 inf_state
->siginfo_data
= siginfo_data
;
8858 inf_state
->thread_suspend
= tp
->suspend
;
8860 /* run_inferior_call will not use the signal due to its `proceed' call with
8861 GDB_SIGNAL_0 anyway. */
8862 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8864 inf_state
->stop_pc
= stop_pc
;
8866 inf_state
->registers
= regcache_dup (regcache
);
8871 /* Restore inferior session state to INF_STATE. */
8874 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8876 struct thread_info
*tp
= inferior_thread ();
8877 struct regcache
*regcache
= get_current_regcache ();
8878 struct gdbarch
*gdbarch
= regcache
->arch ();
8880 tp
->suspend
= inf_state
->thread_suspend
;
8882 stop_pc
= inf_state
->stop_pc
;
8884 if (inf_state
->siginfo_gdbarch
== gdbarch
)
8886 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8888 /* Errors ignored. */
8889 target_write (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8890 inf_state
->siginfo_data
, 0, TYPE_LENGTH (type
));
8893 /* The inferior can be gone if the user types "print exit(0)"
8894 (and perhaps other times). */
8895 if (target_has_execution
)
8896 /* NB: The register write goes through to the target. */
8897 regcache_cpy (regcache
, inf_state
->registers
);
8899 discard_infcall_suspend_state (inf_state
);
8903 do_restore_infcall_suspend_state_cleanup (void *state
)
8905 restore_infcall_suspend_state ((struct infcall_suspend_state
*) state
);
8909 make_cleanup_restore_infcall_suspend_state
8910 (struct infcall_suspend_state
*inf_state
)
8912 return make_cleanup (do_restore_infcall_suspend_state_cleanup
, inf_state
);
8916 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8918 delete inf_state
->registers
;
8919 xfree (inf_state
->siginfo_data
);
8924 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8926 return inf_state
->registers
;
8929 /* infcall_control_state contains state regarding gdb's control of the
8930 inferior itself like stepping control. It also contains session state like
8931 the user's currently selected frame. */
8933 struct infcall_control_state
8935 struct thread_control_state thread_control
;
8936 struct inferior_control_state inferior_control
;
8939 enum stop_stack_kind stop_stack_dummy
;
8940 int stopped_by_random_signal
;
8942 /* ID if the selected frame when the inferior function call was made. */
8943 struct frame_id selected_frame_id
;
8946 /* Save all of the information associated with the inferior<==>gdb
8949 struct infcall_control_state
*
8950 save_infcall_control_state (void)
8952 struct infcall_control_state
*inf_status
=
8953 XNEW (struct infcall_control_state
);
8954 struct thread_info
*tp
= inferior_thread ();
8955 struct inferior
*inf
= current_inferior ();
8957 inf_status
->thread_control
= tp
->control
;
8958 inf_status
->inferior_control
= inf
->control
;
8960 tp
->control
.step_resume_breakpoint
= NULL
;
8961 tp
->control
.exception_resume_breakpoint
= NULL
;
8963 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8964 chain. If caller's caller is walking the chain, they'll be happier if we
8965 hand them back the original chain when restore_infcall_control_state is
8967 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8970 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8971 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8973 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
8979 restore_selected_frame (const frame_id
&fid
)
8981 frame_info
*frame
= frame_find_by_id (fid
);
8983 /* If inf_status->selected_frame_id is NULL, there was no previously
8987 warning (_("Unable to restore previously selected frame."));
8991 select_frame (frame
);
8994 /* Restore inferior session state to INF_STATUS. */
8997 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8999 struct thread_info
*tp
= inferior_thread ();
9000 struct inferior
*inf
= current_inferior ();
9002 if (tp
->control
.step_resume_breakpoint
)
9003 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9005 if (tp
->control
.exception_resume_breakpoint
)
9006 tp
->control
.exception_resume_breakpoint
->disposition
9007 = disp_del_at_next_stop
;
9009 /* Handle the bpstat_copy of the chain. */
9010 bpstat_clear (&tp
->control
.stop_bpstat
);
9012 tp
->control
= inf_status
->thread_control
;
9013 inf
->control
= inf_status
->inferior_control
;
9016 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9017 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9019 if (target_has_stack
)
9021 /* The point of the try/catch is that if the stack is clobbered,
9022 walking the stack might encounter a garbage pointer and
9023 error() trying to dereference it. */
9026 restore_selected_frame (inf_status
->selected_frame_id
);
9028 CATCH (ex
, RETURN_MASK_ERROR
)
9030 exception_fprintf (gdb_stderr
, ex
,
9031 "Unable to restore previously selected frame:\n");
9032 /* Error in restoring the selected frame. Select the
9034 select_frame (get_current_frame ());
9043 do_restore_infcall_control_state_cleanup (void *sts
)
9045 restore_infcall_control_state ((struct infcall_control_state
*) sts
);
9049 make_cleanup_restore_infcall_control_state
9050 (struct infcall_control_state
*inf_status
)
9052 return make_cleanup (do_restore_infcall_control_state_cleanup
, inf_status
);
9056 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9058 if (inf_status
->thread_control
.step_resume_breakpoint
)
9059 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9060 = disp_del_at_next_stop
;
9062 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9063 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9064 = disp_del_at_next_stop
;
9066 /* See save_infcall_control_state for info on stop_bpstat. */
9067 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9075 clear_exit_convenience_vars (void)
9077 clear_internalvar (lookup_internalvar ("_exitsignal"));
9078 clear_internalvar (lookup_internalvar ("_exitcode"));
9082 /* User interface for reverse debugging:
9083 Set exec-direction / show exec-direction commands
9084 (returns error unless target implements to_set_exec_direction method). */
9086 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9087 static const char exec_forward
[] = "forward";
9088 static const char exec_reverse
[] = "reverse";
9089 static const char *exec_direction
= exec_forward
;
9090 static const char *const exec_direction_names
[] = {
9097 set_exec_direction_func (const char *args
, int from_tty
,
9098 struct cmd_list_element
*cmd
)
9100 if (target_can_execute_reverse
)
9102 if (!strcmp (exec_direction
, exec_forward
))
9103 execution_direction
= EXEC_FORWARD
;
9104 else if (!strcmp (exec_direction
, exec_reverse
))
9105 execution_direction
= EXEC_REVERSE
;
9109 exec_direction
= exec_forward
;
9110 error (_("Target does not support this operation."));
9115 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9116 struct cmd_list_element
*cmd
, const char *value
)
9118 switch (execution_direction
) {
9120 fprintf_filtered (out
, _("Forward.\n"));
9123 fprintf_filtered (out
, _("Reverse.\n"));
9126 internal_error (__FILE__
, __LINE__
,
9127 _("bogus execution_direction value: %d"),
9128 (int) execution_direction
);
9133 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9134 struct cmd_list_element
*c
, const char *value
)
9136 fprintf_filtered (file
, _("Resuming the execution of threads "
9137 "of all processes is %s.\n"), value
);
9140 /* Implementation of `siginfo' variable. */
9142 static const struct internalvar_funcs siginfo_funcs
=
9149 /* Callback for infrun's target events source. This is marked when a
9150 thread has a pending status to process. */
9153 infrun_async_inferior_event_handler (gdb_client_data data
)
9155 inferior_event_handler (INF_REG_EVENT
, NULL
);
9159 _initialize_infrun (void)
9163 struct cmd_list_element
*c
;
9165 /* Register extra event sources in the event loop. */
9166 infrun_async_inferior_event_token
9167 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9169 add_info ("signals", info_signals_command
, _("\
9170 What debugger does when program gets various signals.\n\
9171 Specify a signal as argument to print info on that signal only."));
9172 add_info_alias ("handle", "signals", 0);
9174 c
= add_com ("handle", class_run
, handle_command
, _("\
9175 Specify how to handle signals.\n\
9176 Usage: handle SIGNAL [ACTIONS]\n\
9177 Args are signals and actions to apply to those signals.\n\
9178 If no actions are specified, the current settings for the specified signals\n\
9179 will be displayed instead.\n\
9181 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9182 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9183 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9184 The special arg \"all\" is recognized to mean all signals except those\n\
9185 used by the debugger, typically SIGTRAP and SIGINT.\n\
9187 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9188 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9189 Stop means reenter debugger if this signal happens (implies print).\n\
9190 Print means print a message if this signal happens.\n\
9191 Pass means let program see this signal; otherwise program doesn't know.\n\
9192 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9193 Pass and Stop may be combined.\n\
9195 Multiple signals may be specified. Signal numbers and signal names\n\
9196 may be interspersed with actions, with the actions being performed for\n\
9197 all signals cumulatively specified."));
9198 set_cmd_completer (c
, handle_completer
);
9201 stop_command
= add_cmd ("stop", class_obscure
,
9202 not_just_help_class_command
, _("\
9203 There is no `stop' command, but you can set a hook on `stop'.\n\
9204 This allows you to set a list of commands to be run each time execution\n\
9205 of the program stops."), &cmdlist
);
9207 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9208 Set inferior debugging."), _("\
9209 Show inferior debugging."), _("\
9210 When non-zero, inferior specific debugging is enabled."),
9213 &setdebuglist
, &showdebuglist
);
9215 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9216 &debug_displaced
, _("\
9217 Set displaced stepping debugging."), _("\
9218 Show displaced stepping debugging."), _("\
9219 When non-zero, displaced stepping specific debugging is enabled."),
9221 show_debug_displaced
,
9222 &setdebuglist
, &showdebuglist
);
9224 add_setshow_boolean_cmd ("non-stop", no_class
,
9226 Set whether gdb controls the inferior in non-stop mode."), _("\
9227 Show whether gdb controls the inferior in non-stop mode."), _("\
9228 When debugging a multi-threaded program and this setting is\n\
9229 off (the default, also called all-stop mode), when one thread stops\n\
9230 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9231 all other threads in the program while you interact with the thread of\n\
9232 interest. When you continue or step a thread, you can allow the other\n\
9233 threads to run, or have them remain stopped, but while you inspect any\n\
9234 thread's state, all threads stop.\n\
9236 In non-stop mode, when one thread stops, other threads can continue\n\
9237 to run freely. You'll be able to step each thread independently,\n\
9238 leave it stopped or free to run as needed."),
9244 numsigs
= (int) GDB_SIGNAL_LAST
;
9245 signal_stop
= XNEWVEC (unsigned char, numsigs
);
9246 signal_print
= XNEWVEC (unsigned char, numsigs
);
9247 signal_program
= XNEWVEC (unsigned char, numsigs
);
9248 signal_catch
= XNEWVEC (unsigned char, numsigs
);
9249 signal_pass
= XNEWVEC (unsigned char, numsigs
);
9250 for (i
= 0; i
< numsigs
; i
++)
9253 signal_print
[i
] = 1;
9254 signal_program
[i
] = 1;
9255 signal_catch
[i
] = 0;
9258 /* Signals caused by debugger's own actions should not be given to
9259 the program afterwards.
9261 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9262 explicitly specifies that it should be delivered to the target
9263 program. Typically, that would occur when a user is debugging a
9264 target monitor on a simulator: the target monitor sets a
9265 breakpoint; the simulator encounters this breakpoint and halts
9266 the simulation handing control to GDB; GDB, noting that the stop
9267 address doesn't map to any known breakpoint, returns control back
9268 to the simulator; the simulator then delivers the hardware
9269 equivalent of a GDB_SIGNAL_TRAP to the program being
9271 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9272 signal_program
[GDB_SIGNAL_INT
] = 0;
9274 /* Signals that are not errors should not normally enter the debugger. */
9275 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9276 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9277 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9278 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9279 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9280 signal_print
[GDB_SIGNAL_PROF
] = 0;
9281 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9282 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9283 signal_stop
[GDB_SIGNAL_IO
] = 0;
9284 signal_print
[GDB_SIGNAL_IO
] = 0;
9285 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9286 signal_print
[GDB_SIGNAL_POLL
] = 0;
9287 signal_stop
[GDB_SIGNAL_URG
] = 0;
9288 signal_print
[GDB_SIGNAL_URG
] = 0;
9289 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9290 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9291 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9292 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9294 /* These signals are used internally by user-level thread
9295 implementations. (See signal(5) on Solaris.) Like the above
9296 signals, a healthy program receives and handles them as part of
9297 its normal operation. */
9298 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9299 signal_print
[GDB_SIGNAL_LWP
] = 0;
9300 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9301 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9302 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9303 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9304 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9305 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9307 /* Update cached state. */
9308 signal_cache_update (-1);
9310 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9311 &stop_on_solib_events
, _("\
9312 Set stopping for shared library events."), _("\
9313 Show stopping for shared library events."), _("\
9314 If nonzero, gdb will give control to the user when the dynamic linker\n\
9315 notifies gdb of shared library events. The most common event of interest\n\
9316 to the user would be loading/unloading of a new library."),
9317 set_stop_on_solib_events
,
9318 show_stop_on_solib_events
,
9319 &setlist
, &showlist
);
9321 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9322 follow_fork_mode_kind_names
,
9323 &follow_fork_mode_string
, _("\
9324 Set debugger response to a program call of fork or vfork."), _("\
9325 Show debugger response to a program call of fork or vfork."), _("\
9326 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9327 parent - the original process is debugged after a fork\n\
9328 child - the new process is debugged after a fork\n\
9329 The unfollowed process will continue to run.\n\
9330 By default, the debugger will follow the parent process."),
9332 show_follow_fork_mode_string
,
9333 &setlist
, &showlist
);
9335 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9336 follow_exec_mode_names
,
9337 &follow_exec_mode_string
, _("\
9338 Set debugger response to a program call of exec."), _("\
9339 Show debugger response to a program call of exec."), _("\
9340 An exec call replaces the program image of a process.\n\
9342 follow-exec-mode can be:\n\
9344 new - the debugger creates a new inferior and rebinds the process\n\
9345 to this new inferior. The program the process was running before\n\
9346 the exec call can be restarted afterwards by restarting the original\n\
9349 same - the debugger keeps the process bound to the same inferior.\n\
9350 The new executable image replaces the previous executable loaded in\n\
9351 the inferior. Restarting the inferior after the exec call restarts\n\
9352 the executable the process was running after the exec call.\n\
9354 By default, the debugger will use the same inferior."),
9356 show_follow_exec_mode_string
,
9357 &setlist
, &showlist
);
9359 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9360 scheduler_enums
, &scheduler_mode
, _("\
9361 Set mode for locking scheduler during execution."), _("\
9362 Show mode for locking scheduler during execution."), _("\
9363 off == no locking (threads may preempt at any time)\n\
9364 on == full locking (no thread except the current thread may run)\n\
9365 This applies to both normal execution and replay mode.\n\
9366 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9367 In this mode, other threads may run during other commands.\n\
9368 This applies to both normal execution and replay mode.\n\
9369 replay == scheduler locked in replay mode and unlocked during normal execution."),
9370 set_schedlock_func
, /* traps on target vector */
9371 show_scheduler_mode
,
9372 &setlist
, &showlist
);
9374 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9375 Set mode for resuming threads of all processes."), _("\
9376 Show mode for resuming threads of all processes."), _("\
9377 When on, execution commands (such as 'continue' or 'next') resume all\n\
9378 threads of all processes. When off (which is the default), execution\n\
9379 commands only resume the threads of the current process. The set of\n\
9380 threads that are resumed is further refined by the scheduler-locking\n\
9381 mode (see help set scheduler-locking)."),
9383 show_schedule_multiple
,
9384 &setlist
, &showlist
);
9386 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9387 Set mode of the step operation."), _("\
9388 Show mode of the step operation."), _("\
9389 When set, doing a step over a function without debug line information\n\
9390 will stop at the first instruction of that function. Otherwise, the\n\
9391 function is skipped and the step command stops at a different source line."),
9393 show_step_stop_if_no_debug
,
9394 &setlist
, &showlist
);
9396 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9397 &can_use_displaced_stepping
, _("\
9398 Set debugger's willingness to use displaced stepping."), _("\
9399 Show debugger's willingness to use displaced stepping."), _("\
9400 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9401 supported by the target architecture. If off, gdb will not use displaced\n\
9402 stepping to step over breakpoints, even if such is supported by the target\n\
9403 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9404 if the target architecture supports it and non-stop mode is active, but will not\n\
9405 use it in all-stop mode (see help set non-stop)."),
9407 show_can_use_displaced_stepping
,
9408 &setlist
, &showlist
);
9410 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9411 &exec_direction
, _("Set direction of execution.\n\
9412 Options are 'forward' or 'reverse'."),
9413 _("Show direction of execution (forward/reverse)."),
9414 _("Tells gdb whether to execute forward or backward."),
9415 set_exec_direction_func
, show_exec_direction_func
,
9416 &setlist
, &showlist
);
9418 /* Set/show detach-on-fork: user-settable mode. */
9420 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9421 Set whether gdb will detach the child of a fork."), _("\
9422 Show whether gdb will detach the child of a fork."), _("\
9423 Tells gdb whether to detach the child of a fork."),
9424 NULL
, NULL
, &setlist
, &showlist
);
9426 /* Set/show disable address space randomization mode. */
9428 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9429 &disable_randomization
, _("\
9430 Set disabling of debuggee's virtual address space randomization."), _("\
9431 Show disabling of debuggee's virtual address space randomization."), _("\
9432 When this mode is on (which is the default), randomization of the virtual\n\
9433 address space is disabled. Standalone programs run with the randomization\n\
9434 enabled by default on some platforms."),
9435 &set_disable_randomization
,
9436 &show_disable_randomization
,
9437 &setlist
, &showlist
);
9439 /* ptid initializations */
9440 inferior_ptid
= null_ptid
;
9441 target_last_wait_ptid
= minus_one_ptid
;
9443 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed
);
9444 observer_attach_thread_stop_requested (infrun_thread_stop_requested
);
9445 observer_attach_thread_exit (infrun_thread_thread_exit
);
9446 observer_attach_inferior_exit (infrun_inferior_exit
);
9448 /* Explicitly create without lookup, since that tries to create a
9449 value with a void typed value, and when we get here, gdbarch
9450 isn't initialized yet. At this point, we're quite sure there
9451 isn't another convenience variable of the same name. */
9452 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9454 add_setshow_boolean_cmd ("observer", no_class
,
9455 &observer_mode_1
, _("\
9456 Set whether gdb controls the inferior in observer mode."), _("\
9457 Show whether gdb controls the inferior in observer mode."), _("\
9458 In observer mode, GDB can get data from the inferior, but not\n\
9459 affect its execution. Registers and memory may not be changed,\n\
9460 breakpoints may not be set, and the program cannot be interrupted\n\