1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
5 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
6 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "gdb_string.h"
29 #include "exceptions.h"
30 #include "breakpoint.h"
34 #include "cli/cli-script.h"
36 #include "gdbthread.h"
48 #include "dictionary.h"
50 #include "gdb_assert.h"
51 #include "mi/mi-common.h"
52 #include "event-top.h"
54 #include "inline-frame.h"
56 #include "tracepoint.h"
57 #include "continuations.h"
59 /* Prototypes for local functions */
61 static void signals_info (char *, int);
63 static void handle_command (char *, int);
65 static void sig_print_info (enum target_signal
);
67 static void sig_print_header (void);
69 static void resume_cleanups (void *);
71 static int hook_stop_stub (void *);
73 static int restore_selected_frame (void *);
75 static int follow_fork (void);
77 static void set_schedlock_func (char *args
, int from_tty
,
78 struct cmd_list_element
*c
);
80 static int currently_stepping (struct thread_info
*tp
);
82 static int currently_stepping_or_nexting_callback (struct thread_info
*tp
,
85 static void xdb_handle_command (char *args
, int from_tty
);
87 static int prepare_to_proceed (int);
89 static void print_exited_reason (int exitstatus
);
91 static void print_signal_exited_reason (enum target_signal siggnal
);
93 static void print_no_history_reason (void);
95 static void print_signal_received_reason (enum target_signal siggnal
);
97 static void print_end_stepping_range_reason (void);
99 void _initialize_infrun (void);
101 void nullify_last_target_wait_ptid (void);
103 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
105 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
107 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
109 /* When set, stop the 'step' command if we enter a function which has
110 no line number information. The normal behavior is that we step
111 over such function. */
112 int step_stop_if_no_debug
= 0;
114 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
115 struct cmd_list_element
*c
, const char *value
)
117 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
120 /* In asynchronous mode, but simulating synchronous execution. */
122 int sync_execution
= 0;
124 /* wait_for_inferior and normal_stop use this to notify the user
125 when the inferior stopped in a different thread than it had been
128 static ptid_t previous_inferior_ptid
;
130 /* Default behavior is to detach newly forked processes (legacy). */
133 int debug_displaced
= 0;
135 show_debug_displaced (struct ui_file
*file
, int from_tty
,
136 struct cmd_list_element
*c
, const char *value
)
138 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
141 int debug_infrun
= 0;
143 show_debug_infrun (struct ui_file
*file
, int from_tty
,
144 struct cmd_list_element
*c
, const char *value
)
146 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
149 /* If the program uses ELF-style shared libraries, then calls to
150 functions in shared libraries go through stubs, which live in a
151 table called the PLT (Procedure Linkage Table). The first time the
152 function is called, the stub sends control to the dynamic linker,
153 which looks up the function's real address, patches the stub so
154 that future calls will go directly to the function, and then passes
155 control to the function.
157 If we are stepping at the source level, we don't want to see any of
158 this --- we just want to skip over the stub and the dynamic linker.
159 The simple approach is to single-step until control leaves the
162 However, on some systems (e.g., Red Hat's 5.2 distribution) the
163 dynamic linker calls functions in the shared C library, so you
164 can't tell from the PC alone whether the dynamic linker is still
165 running. In this case, we use a step-resume breakpoint to get us
166 past the dynamic linker, as if we were using "next" to step over a
169 in_solib_dynsym_resolve_code() says whether we're in the dynamic
170 linker code or not. Normally, this means we single-step. However,
171 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
172 address where we can place a step-resume breakpoint to get past the
173 linker's symbol resolution function.
175 in_solib_dynsym_resolve_code() can generally be implemented in a
176 pretty portable way, by comparing the PC against the address ranges
177 of the dynamic linker's sections.
179 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
180 it depends on internal details of the dynamic linker. It's usually
181 not too hard to figure out where to put a breakpoint, but it
182 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of
183 sanity checking. If it can't figure things out, returning zero and
184 getting the (possibly confusing) stepping behavior is better than
185 signalling an error, which will obscure the change in the
188 /* This function returns TRUE if pc is the address of an instruction
189 that lies within the dynamic linker (such as the event hook, or the
192 This function must be used only when a dynamic linker event has
193 been caught, and the inferior is being stepped out of the hook, or
194 undefined results are guaranteed. */
196 #ifndef SOLIB_IN_DYNAMIC_LINKER
197 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
200 /* "Observer mode" is somewhat like a more extreme version of
201 non-stop, in which all GDB operations that might affect the
202 target's execution have been disabled. */
204 static int non_stop_1
= 0;
206 int observer_mode
= 0;
207 static int observer_mode_1
= 0;
210 set_observer_mode (char *args
, int from_tty
,
211 struct cmd_list_element
*c
)
213 extern int pagination_enabled
;
215 if (target_has_execution
)
217 observer_mode_1
= observer_mode
;
218 error (_("Cannot change this setting while the inferior is running."));
221 observer_mode
= observer_mode_1
;
223 may_write_registers
= !observer_mode
;
224 may_write_memory
= !observer_mode
;
225 may_insert_breakpoints
= !observer_mode
;
226 may_insert_tracepoints
= !observer_mode
;
227 /* We can insert fast tracepoints in or out of observer mode,
228 but enable them if we're going into this mode. */
230 may_insert_fast_tracepoints
= 1;
231 may_stop
= !observer_mode
;
232 update_target_permissions ();
234 /* Going *into* observer mode we must force non-stop, then
235 going out we leave it that way. */
238 target_async_permitted
= 1;
239 pagination_enabled
= 0;
240 non_stop
= non_stop_1
= 1;
244 printf_filtered (_("Observer mode is now %s.\n"),
245 (observer_mode
? "on" : "off"));
249 show_observer_mode (struct ui_file
*file
, int from_tty
,
250 struct cmd_list_element
*c
, const char *value
)
252 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
255 /* This updates the value of observer mode based on changes in
256 permissions. Note that we are deliberately ignoring the values of
257 may-write-registers and may-write-memory, since the user may have
258 reason to enable these during a session, for instance to turn on a
259 debugging-related global. */
262 update_observer_mode (void)
266 newval
= (!may_insert_breakpoints
267 && !may_insert_tracepoints
268 && may_insert_fast_tracepoints
272 /* Let the user know if things change. */
273 if (newval
!= observer_mode
)
274 printf_filtered (_("Observer mode is now %s.\n"),
275 (newval
? "on" : "off"));
277 observer_mode
= observer_mode_1
= newval
;
280 /* Tables of how to react to signals; the user sets them. */
282 static unsigned char *signal_stop
;
283 static unsigned char *signal_print
;
284 static unsigned char *signal_program
;
286 /* Table of signals that the target may silently handle.
287 This is automatically determined from the flags above,
288 and simply cached here. */
289 static unsigned char *signal_pass
;
291 #define SET_SIGS(nsigs,sigs,flags) \
293 int signum = (nsigs); \
294 while (signum-- > 0) \
295 if ((sigs)[signum]) \
296 (flags)[signum] = 1; \
299 #define UNSET_SIGS(nsigs,sigs,flags) \
301 int signum = (nsigs); \
302 while (signum-- > 0) \
303 if ((sigs)[signum]) \
304 (flags)[signum] = 0; \
307 /* Value to pass to target_resume() to cause all threads to resume. */
309 #define RESUME_ALL minus_one_ptid
311 /* Command list pointer for the "stop" placeholder. */
313 static struct cmd_list_element
*stop_command
;
315 /* Function inferior was in as of last step command. */
317 static struct symbol
*step_start_function
;
319 /* Nonzero if we want to give control to the user when we're notified
320 of shared library events by the dynamic linker. */
321 int stop_on_solib_events
;
323 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
324 struct cmd_list_element
*c
, const char *value
)
326 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
330 /* Nonzero means expecting a trace trap
331 and should stop the inferior and return silently when it happens. */
335 /* Save register contents here when executing a "finish" command or are
336 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
337 Thus this contains the return value from the called function (assuming
338 values are returned in a register). */
340 struct regcache
*stop_registers
;
342 /* Nonzero after stop if current stack frame should be printed. */
344 static int stop_print_frame
;
346 /* This is a cached copy of the pid/waitstatus of the last event
347 returned by target_wait()/deprecated_target_wait_hook(). This
348 information is returned by get_last_target_status(). */
349 static ptid_t target_last_wait_ptid
;
350 static struct target_waitstatus target_last_waitstatus
;
352 static void context_switch (ptid_t ptid
);
354 void init_thread_stepping_state (struct thread_info
*tss
);
356 void init_infwait_state (void);
358 static const char follow_fork_mode_child
[] = "child";
359 static const char follow_fork_mode_parent
[] = "parent";
361 static const char *follow_fork_mode_kind_names
[] = {
362 follow_fork_mode_child
,
363 follow_fork_mode_parent
,
367 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
369 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
370 struct cmd_list_element
*c
, const char *value
)
372 fprintf_filtered (file
,
373 _("Debugger response to a program "
374 "call of fork or vfork is \"%s\".\n"),
379 /* Tell the target to follow the fork we're stopped at. Returns true
380 if the inferior should be resumed; false, if the target for some
381 reason decided it's best not to resume. */
386 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
387 int should_resume
= 1;
388 struct thread_info
*tp
;
390 /* Copy user stepping state to the new inferior thread. FIXME: the
391 followed fork child thread should have a copy of most of the
392 parent thread structure's run control related fields, not just these.
393 Initialized to avoid "may be used uninitialized" warnings from gcc. */
394 struct breakpoint
*step_resume_breakpoint
= NULL
;
395 struct breakpoint
*exception_resume_breakpoint
= NULL
;
396 CORE_ADDR step_range_start
= 0;
397 CORE_ADDR step_range_end
= 0;
398 struct frame_id step_frame_id
= { 0 };
403 struct target_waitstatus wait_status
;
405 /* Get the last target status returned by target_wait(). */
406 get_last_target_status (&wait_ptid
, &wait_status
);
408 /* If not stopped at a fork event, then there's nothing else to
410 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
411 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
414 /* Check if we switched over from WAIT_PTID, since the event was
416 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
417 && !ptid_equal (inferior_ptid
, wait_ptid
))
419 /* We did. Switch back to WAIT_PTID thread, to tell the
420 target to follow it (in either direction). We'll
421 afterwards refuse to resume, and inform the user what
423 switch_to_thread (wait_ptid
);
428 tp
= inferior_thread ();
430 /* If there were any forks/vforks that were caught and are now to be
431 followed, then do so now. */
432 switch (tp
->pending_follow
.kind
)
434 case TARGET_WAITKIND_FORKED
:
435 case TARGET_WAITKIND_VFORKED
:
437 ptid_t parent
, child
;
439 /* If the user did a next/step, etc, over a fork call,
440 preserve the stepping state in the fork child. */
441 if (follow_child
&& should_resume
)
443 step_resume_breakpoint
= clone_momentary_breakpoint
444 (tp
->control
.step_resume_breakpoint
);
445 step_range_start
= tp
->control
.step_range_start
;
446 step_range_end
= tp
->control
.step_range_end
;
447 step_frame_id
= tp
->control
.step_frame_id
;
448 exception_resume_breakpoint
449 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
451 /* For now, delete the parent's sr breakpoint, otherwise,
452 parent/child sr breakpoints are considered duplicates,
453 and the child version will not be installed. Remove
454 this when the breakpoints module becomes aware of
455 inferiors and address spaces. */
456 delete_step_resume_breakpoint (tp
);
457 tp
->control
.step_range_start
= 0;
458 tp
->control
.step_range_end
= 0;
459 tp
->control
.step_frame_id
= null_frame_id
;
460 delete_exception_resume_breakpoint (tp
);
463 parent
= inferior_ptid
;
464 child
= tp
->pending_follow
.value
.related_pid
;
466 /* Tell the target to do whatever is necessary to follow
467 either parent or child. */
468 if (target_follow_fork (follow_child
))
470 /* Target refused to follow, or there's some other reason
471 we shouldn't resume. */
476 /* This pending follow fork event is now handled, one way
477 or another. The previous selected thread may be gone
478 from the lists by now, but if it is still around, need
479 to clear the pending follow request. */
480 tp
= find_thread_ptid (parent
);
482 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
484 /* This makes sure we don't try to apply the "Switched
485 over from WAIT_PID" logic above. */
486 nullify_last_target_wait_ptid ();
488 /* If we followed the child, switch to it... */
491 switch_to_thread (child
);
493 /* ... and preserve the stepping state, in case the
494 user was stepping over the fork call. */
497 tp
= inferior_thread ();
498 tp
->control
.step_resume_breakpoint
499 = step_resume_breakpoint
;
500 tp
->control
.step_range_start
= step_range_start
;
501 tp
->control
.step_range_end
= step_range_end
;
502 tp
->control
.step_frame_id
= step_frame_id
;
503 tp
->control
.exception_resume_breakpoint
504 = exception_resume_breakpoint
;
508 /* If we get here, it was because we're trying to
509 resume from a fork catchpoint, but, the user
510 has switched threads away from the thread that
511 forked. In that case, the resume command
512 issued is most likely not applicable to the
513 child, so just warn, and refuse to resume. */
514 warning (_("Not resuming: switched threads "
515 "before following fork child.\n"));
518 /* Reset breakpoints in the child as appropriate. */
519 follow_inferior_reset_breakpoints ();
522 switch_to_thread (parent
);
526 case TARGET_WAITKIND_SPURIOUS
:
527 /* Nothing to follow. */
530 internal_error (__FILE__
, __LINE__
,
531 "Unexpected pending_follow.kind %d\n",
532 tp
->pending_follow
.kind
);
536 return should_resume
;
540 follow_inferior_reset_breakpoints (void)
542 struct thread_info
*tp
= inferior_thread ();
544 /* Was there a step_resume breakpoint? (There was if the user
545 did a "next" at the fork() call.) If so, explicitly reset its
548 step_resumes are a form of bp that are made to be per-thread.
549 Since we created the step_resume bp when the parent process
550 was being debugged, and now are switching to the child process,
551 from the breakpoint package's viewpoint, that's a switch of
552 "threads". We must update the bp's notion of which thread
553 it is for, or it'll be ignored when it triggers. */
555 if (tp
->control
.step_resume_breakpoint
)
556 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
558 if (tp
->control
.exception_resume_breakpoint
)
559 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
561 /* Reinsert all breakpoints in the child. The user may have set
562 breakpoints after catching the fork, in which case those
563 were never set in the child, but only in the parent. This makes
564 sure the inserted breakpoints match the breakpoint list. */
566 breakpoint_re_set ();
567 insert_breakpoints ();
570 /* The child has exited or execed: resume threads of the parent the
571 user wanted to be executing. */
574 proceed_after_vfork_done (struct thread_info
*thread
,
577 int pid
= * (int *) arg
;
579 if (ptid_get_pid (thread
->ptid
) == pid
580 && is_running (thread
->ptid
)
581 && !is_executing (thread
->ptid
)
582 && !thread
->stop_requested
583 && thread
->suspend
.stop_signal
== TARGET_SIGNAL_0
)
586 fprintf_unfiltered (gdb_stdlog
,
587 "infrun: resuming vfork parent thread %s\n",
588 target_pid_to_str (thread
->ptid
));
590 switch_to_thread (thread
->ptid
);
591 clear_proceed_status ();
592 proceed ((CORE_ADDR
) -1, TARGET_SIGNAL_DEFAULT
, 0);
598 /* Called whenever we notice an exec or exit event, to handle
599 detaching or resuming a vfork parent. */
602 handle_vfork_child_exec_or_exit (int exec
)
604 struct inferior
*inf
= current_inferior ();
606 if (inf
->vfork_parent
)
608 int resume_parent
= -1;
610 /* This exec or exit marks the end of the shared memory region
611 between the parent and the child. If the user wanted to
612 detach from the parent, now is the time. */
614 if (inf
->vfork_parent
->pending_detach
)
616 struct thread_info
*tp
;
617 struct cleanup
*old_chain
;
618 struct program_space
*pspace
;
619 struct address_space
*aspace
;
621 /* follow-fork child, detach-on-fork on. */
623 old_chain
= make_cleanup_restore_current_thread ();
625 /* We're letting loose of the parent. */
626 tp
= any_live_thread_of_process (inf
->vfork_parent
->pid
);
627 switch_to_thread (tp
->ptid
);
629 /* We're about to detach from the parent, which implicitly
630 removes breakpoints from its address space. There's a
631 catch here: we want to reuse the spaces for the child,
632 but, parent/child are still sharing the pspace at this
633 point, although the exec in reality makes the kernel give
634 the child a fresh set of new pages. The problem here is
635 that the breakpoints module being unaware of this, would
636 likely chose the child process to write to the parent
637 address space. Swapping the child temporarily away from
638 the spaces has the desired effect. Yes, this is "sort
641 pspace
= inf
->pspace
;
642 aspace
= inf
->aspace
;
646 if (debug_infrun
|| info_verbose
)
648 target_terminal_ours ();
651 fprintf_filtered (gdb_stdlog
,
652 "Detaching vfork parent process "
653 "%d after child exec.\n",
654 inf
->vfork_parent
->pid
);
656 fprintf_filtered (gdb_stdlog
,
657 "Detaching vfork parent process "
658 "%d after child exit.\n",
659 inf
->vfork_parent
->pid
);
662 target_detach (NULL
, 0);
665 inf
->pspace
= pspace
;
666 inf
->aspace
= aspace
;
668 do_cleanups (old_chain
);
672 /* We're staying attached to the parent, so, really give the
673 child a new address space. */
674 inf
->pspace
= add_program_space (maybe_new_address_space ());
675 inf
->aspace
= inf
->pspace
->aspace
;
677 set_current_program_space (inf
->pspace
);
679 resume_parent
= inf
->vfork_parent
->pid
;
681 /* Break the bonds. */
682 inf
->vfork_parent
->vfork_child
= NULL
;
686 struct cleanup
*old_chain
;
687 struct program_space
*pspace
;
689 /* If this is a vfork child exiting, then the pspace and
690 aspaces were shared with the parent. Since we're
691 reporting the process exit, we'll be mourning all that is
692 found in the address space, and switching to null_ptid,
693 preparing to start a new inferior. But, since we don't
694 want to clobber the parent's address/program spaces, we
695 go ahead and create a new one for this exiting
698 /* Switch to null_ptid, so that clone_program_space doesn't want
699 to read the selected frame of a dead process. */
700 old_chain
= save_inferior_ptid ();
701 inferior_ptid
= null_ptid
;
703 /* This inferior is dead, so avoid giving the breakpoints
704 module the option to write through to it (cloning a
705 program space resets breakpoints). */
708 pspace
= add_program_space (maybe_new_address_space ());
709 set_current_program_space (pspace
);
711 clone_program_space (pspace
, inf
->vfork_parent
->pspace
);
712 inf
->pspace
= pspace
;
713 inf
->aspace
= pspace
->aspace
;
715 /* Put back inferior_ptid. We'll continue mourning this
717 do_cleanups (old_chain
);
719 resume_parent
= inf
->vfork_parent
->pid
;
720 /* Break the bonds. */
721 inf
->vfork_parent
->vfork_child
= NULL
;
724 inf
->vfork_parent
= NULL
;
726 gdb_assert (current_program_space
== inf
->pspace
);
728 if (non_stop
&& resume_parent
!= -1)
730 /* If the user wanted the parent to be running, let it go
732 struct cleanup
*old_chain
= make_cleanup_restore_current_thread ();
735 fprintf_unfiltered (gdb_stdlog
,
736 "infrun: resuming vfork parent process %d\n",
739 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
741 do_cleanups (old_chain
);
746 /* Enum strings for "set|show displaced-stepping". */
748 static const char follow_exec_mode_new
[] = "new";
749 static const char follow_exec_mode_same
[] = "same";
750 static const char *follow_exec_mode_names
[] =
752 follow_exec_mode_new
,
753 follow_exec_mode_same
,
757 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
759 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
760 struct cmd_list_element
*c
, const char *value
)
762 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
765 /* EXECD_PATHNAME is assumed to be non-NULL. */
768 follow_exec (ptid_t pid
, char *execd_pathname
)
770 struct thread_info
*th
= inferior_thread ();
771 struct inferior
*inf
= current_inferior ();
773 /* This is an exec event that we actually wish to pay attention to.
774 Refresh our symbol table to the newly exec'd program, remove any
777 If there are breakpoints, they aren't really inserted now,
778 since the exec() transformed our inferior into a fresh set
781 We want to preserve symbolic breakpoints on the list, since
782 we have hopes that they can be reset after the new a.out's
783 symbol table is read.
785 However, any "raw" breakpoints must be removed from the list
786 (e.g., the solib bp's), since their address is probably invalid
789 And, we DON'T want to call delete_breakpoints() here, since
790 that may write the bp's "shadow contents" (the instruction
791 value that was overwritten witha TRAP instruction). Since
792 we now have a new a.out, those shadow contents aren't valid. */
794 mark_breakpoints_out ();
796 update_breakpoints_after_exec ();
798 /* If there was one, it's gone now. We cannot truly step-to-next
799 statement through an exec(). */
800 th
->control
.step_resume_breakpoint
= NULL
;
801 th
->control
.exception_resume_breakpoint
= NULL
;
802 th
->control
.step_range_start
= 0;
803 th
->control
.step_range_end
= 0;
805 /* The target reports the exec event to the main thread, even if
806 some other thread does the exec, and even if the main thread was
807 already stopped --- if debugging in non-stop mode, it's possible
808 the user had the main thread held stopped in the previous image
809 --- release it now. This is the same behavior as step-over-exec
810 with scheduler-locking on in all-stop mode. */
811 th
->stop_requested
= 0;
813 /* What is this a.out's name? */
814 printf_unfiltered (_("%s is executing new program: %s\n"),
815 target_pid_to_str (inferior_ptid
),
818 /* We've followed the inferior through an exec. Therefore, the
819 inferior has essentially been killed & reborn. */
821 gdb_flush (gdb_stdout
);
823 breakpoint_init_inferior (inf_execd
);
825 if (gdb_sysroot
&& *gdb_sysroot
)
827 char *name
= alloca (strlen (gdb_sysroot
)
828 + strlen (execd_pathname
)
831 strcpy (name
, gdb_sysroot
);
832 strcat (name
, execd_pathname
);
833 execd_pathname
= name
;
836 /* Reset the shared library package. This ensures that we get a
837 shlib event when the child reaches "_start", at which point the
838 dld will have had a chance to initialize the child. */
839 /* Also, loading a symbol file below may trigger symbol lookups, and
840 we don't want those to be satisfied by the libraries of the
841 previous incarnation of this process. */
842 no_shared_libraries (NULL
, 0);
844 if (follow_exec_mode_string
== follow_exec_mode_new
)
846 struct program_space
*pspace
;
848 /* The user wants to keep the old inferior and program spaces
849 around. Create a new fresh one, and switch to it. */
851 inf
= add_inferior (current_inferior ()->pid
);
852 pspace
= add_program_space (maybe_new_address_space ());
853 inf
->pspace
= pspace
;
854 inf
->aspace
= pspace
->aspace
;
856 exit_inferior_num_silent (current_inferior ()->num
);
858 set_current_inferior (inf
);
859 set_current_program_space (pspace
);
862 gdb_assert (current_program_space
== inf
->pspace
);
864 /* That a.out is now the one to use. */
865 exec_file_attach (execd_pathname
, 0);
867 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
868 (Position Independent Executable) main symbol file will get applied by
869 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
870 the breakpoints with the zero displacement. */
872 symbol_file_add (execd_pathname
, SYMFILE_MAINLINE
| SYMFILE_DEFER_BP_RESET
,
875 set_initial_language ();
877 #ifdef SOLIB_CREATE_INFERIOR_HOOK
878 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid
));
880 solib_create_inferior_hook (0);
883 jit_inferior_created_hook ();
885 breakpoint_re_set ();
887 /* Reinsert all breakpoints. (Those which were symbolic have
888 been reset to the proper address in the new a.out, thanks
889 to symbol_file_command...). */
890 insert_breakpoints ();
892 /* The next resume of this inferior should bring it to the shlib
893 startup breakpoints. (If the user had also set bp's on
894 "main" from the old (parent) process, then they'll auto-
895 matically get reset there in the new process.). */
898 /* Non-zero if we just simulating a single-step. This is needed
899 because we cannot remove the breakpoints in the inferior process
900 until after the `wait' in `wait_for_inferior'. */
901 static int singlestep_breakpoints_inserted_p
= 0;
903 /* The thread we inserted single-step breakpoints for. */
904 static ptid_t singlestep_ptid
;
906 /* PC when we started this single-step. */
907 static CORE_ADDR singlestep_pc
;
909 /* If another thread hit the singlestep breakpoint, we save the original
910 thread here so that we can resume single-stepping it later. */
911 static ptid_t saved_singlestep_ptid
;
912 static int stepping_past_singlestep_breakpoint
;
914 /* If not equal to null_ptid, this means that after stepping over breakpoint
915 is finished, we need to switch to deferred_step_ptid, and step it.
917 The use case is when one thread has hit a breakpoint, and then the user
918 has switched to another thread and issued 'step'. We need to step over
919 breakpoint in the thread which hit the breakpoint, but then continue
920 stepping the thread user has selected. */
921 static ptid_t deferred_step_ptid
;
923 /* Displaced stepping. */
925 /* In non-stop debugging mode, we must take special care to manage
926 breakpoints properly; in particular, the traditional strategy for
927 stepping a thread past a breakpoint it has hit is unsuitable.
928 'Displaced stepping' is a tactic for stepping one thread past a
929 breakpoint it has hit while ensuring that other threads running
930 concurrently will hit the breakpoint as they should.
932 The traditional way to step a thread T off a breakpoint in a
933 multi-threaded program in all-stop mode is as follows:
935 a0) Initially, all threads are stopped, and breakpoints are not
937 a1) We single-step T, leaving breakpoints uninserted.
938 a2) We insert breakpoints, and resume all threads.
940 In non-stop debugging, however, this strategy is unsuitable: we
941 don't want to have to stop all threads in the system in order to
942 continue or step T past a breakpoint. Instead, we use displaced
945 n0) Initially, T is stopped, other threads are running, and
946 breakpoints are inserted.
947 n1) We copy the instruction "under" the breakpoint to a separate
948 location, outside the main code stream, making any adjustments
949 to the instruction, register, and memory state as directed by
951 n2) We single-step T over the instruction at its new location.
952 n3) We adjust the resulting register and memory state as directed
953 by T's architecture. This includes resetting T's PC to point
954 back into the main instruction stream.
957 This approach depends on the following gdbarch methods:
959 - gdbarch_max_insn_length and gdbarch_displaced_step_location
960 indicate where to copy the instruction, and how much space must
961 be reserved there. We use these in step n1.
963 - gdbarch_displaced_step_copy_insn copies a instruction to a new
964 address, and makes any necessary adjustments to the instruction,
965 register contents, and memory. We use this in step n1.
967 - gdbarch_displaced_step_fixup adjusts registers and memory after
968 we have successfuly single-stepped the instruction, to yield the
969 same effect the instruction would have had if we had executed it
970 at its original address. We use this in step n3.
972 - gdbarch_displaced_step_free_closure provides cleanup.
974 The gdbarch_displaced_step_copy_insn and
975 gdbarch_displaced_step_fixup functions must be written so that
976 copying an instruction with gdbarch_displaced_step_copy_insn,
977 single-stepping across the copied instruction, and then applying
978 gdbarch_displaced_insn_fixup should have the same effects on the
979 thread's memory and registers as stepping the instruction in place
980 would have. Exactly which responsibilities fall to the copy and
981 which fall to the fixup is up to the author of those functions.
983 See the comments in gdbarch.sh for details.
985 Note that displaced stepping and software single-step cannot
986 currently be used in combination, although with some care I think
987 they could be made to. Software single-step works by placing
988 breakpoints on all possible subsequent instructions; if the
989 displaced instruction is a PC-relative jump, those breakpoints
990 could fall in very strange places --- on pages that aren't
991 executable, or at addresses that are not proper instruction
992 boundaries. (We do generally let other threads run while we wait
993 to hit the software single-step breakpoint, and they might
994 encounter such a corrupted instruction.) One way to work around
995 this would be to have gdbarch_displaced_step_copy_insn fully
996 simulate the effect of PC-relative instructions (and return NULL)
997 on architectures that use software single-stepping.
999 In non-stop mode, we can have independent and simultaneous step
1000 requests, so more than one thread may need to simultaneously step
1001 over a breakpoint. The current implementation assumes there is
1002 only one scratch space per process. In this case, we have to
1003 serialize access to the scratch space. If thread A wants to step
1004 over a breakpoint, but we are currently waiting for some other
1005 thread to complete a displaced step, we leave thread A stopped and
1006 place it in the displaced_step_request_queue. Whenever a displaced
1007 step finishes, we pick the next thread in the queue and start a new
1008 displaced step operation on it. See displaced_step_prepare and
1009 displaced_step_fixup for details. */
1011 struct displaced_step_request
1014 struct displaced_step_request
*next
;
1017 /* Per-inferior displaced stepping state. */
1018 struct displaced_step_inferior_state
1020 /* Pointer to next in linked list. */
1021 struct displaced_step_inferior_state
*next
;
1023 /* The process this displaced step state refers to. */
1026 /* A queue of pending displaced stepping requests. One entry per
1027 thread that needs to do a displaced step. */
1028 struct displaced_step_request
*step_request_queue
;
1030 /* If this is not null_ptid, this is the thread carrying out a
1031 displaced single-step in process PID. This thread's state will
1032 require fixing up once it has completed its step. */
1035 /* The architecture the thread had when we stepped it. */
1036 struct gdbarch
*step_gdbarch
;
1038 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1039 for post-step cleanup. */
1040 struct displaced_step_closure
*step_closure
;
1042 /* The address of the original instruction, and the copy we
1044 CORE_ADDR step_original
, step_copy
;
1046 /* Saved contents of copy area. */
1047 gdb_byte
*step_saved_copy
;
1050 /* The list of states of processes involved in displaced stepping
1052 static struct displaced_step_inferior_state
*displaced_step_inferior_states
;
1054 /* Get the displaced stepping state of process PID. */
1056 static struct displaced_step_inferior_state
*
1057 get_displaced_stepping_state (int pid
)
1059 struct displaced_step_inferior_state
*state
;
1061 for (state
= displaced_step_inferior_states
;
1063 state
= state
->next
)
1064 if (state
->pid
== pid
)
1070 /* Add a new displaced stepping state for process PID to the displaced
1071 stepping state list, or return a pointer to an already existing
1072 entry, if it already exists. Never returns NULL. */
1074 static struct displaced_step_inferior_state
*
1075 add_displaced_stepping_state (int pid
)
1077 struct displaced_step_inferior_state
*state
;
1079 for (state
= displaced_step_inferior_states
;
1081 state
= state
->next
)
1082 if (state
->pid
== pid
)
1085 state
= xcalloc (1, sizeof (*state
));
1087 state
->next
= displaced_step_inferior_states
;
1088 displaced_step_inferior_states
= state
;
1093 /* If inferior is in displaced stepping, and ADDR equals to starting address
1094 of copy area, return corresponding displaced_step_closure. Otherwise,
1097 struct displaced_step_closure
*
1098 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1100 struct displaced_step_inferior_state
*displaced
1101 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
1103 /* If checking the mode of displaced instruction in copy area. */
1104 if (displaced
&& !ptid_equal (displaced
->step_ptid
, null_ptid
)
1105 && (displaced
->step_copy
== addr
))
1106 return displaced
->step_closure
;
1111 /* Remove the displaced stepping state of process PID. */
1114 remove_displaced_stepping_state (int pid
)
1116 struct displaced_step_inferior_state
*it
, **prev_next_p
;
1118 gdb_assert (pid
!= 0);
1120 it
= displaced_step_inferior_states
;
1121 prev_next_p
= &displaced_step_inferior_states
;
1126 *prev_next_p
= it
->next
;
1131 prev_next_p
= &it
->next
;
1137 infrun_inferior_exit (struct inferior
*inf
)
1139 remove_displaced_stepping_state (inf
->pid
);
1142 /* Enum strings for "set|show displaced-stepping". */
1144 static const char can_use_displaced_stepping_auto
[] = "auto";
1145 static const char can_use_displaced_stepping_on
[] = "on";
1146 static const char can_use_displaced_stepping_off
[] = "off";
1147 static const char *can_use_displaced_stepping_enum
[] =
1149 can_use_displaced_stepping_auto
,
1150 can_use_displaced_stepping_on
,
1151 can_use_displaced_stepping_off
,
1155 /* If ON, and the architecture supports it, GDB will use displaced
1156 stepping to step over breakpoints. If OFF, or if the architecture
1157 doesn't support it, GDB will instead use the traditional
1158 hold-and-step approach. If AUTO (which is the default), GDB will
1159 decide which technique to use to step over breakpoints depending on
1160 which of all-stop or non-stop mode is active --- displaced stepping
1161 in non-stop mode; hold-and-step in all-stop mode. */
1163 static const char *can_use_displaced_stepping
=
1164 can_use_displaced_stepping_auto
;
1167 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1168 struct cmd_list_element
*c
,
1171 if (can_use_displaced_stepping
== can_use_displaced_stepping_auto
)
1172 fprintf_filtered (file
,
1173 _("Debugger's willingness to use displaced stepping "
1174 "to step over breakpoints is %s (currently %s).\n"),
1175 value
, non_stop
? "on" : "off");
1177 fprintf_filtered (file
,
1178 _("Debugger's willingness to use displaced stepping "
1179 "to step over breakpoints is %s.\n"), value
);
1182 /* Return non-zero if displaced stepping can/should be used to step
1183 over breakpoints. */
1186 use_displaced_stepping (struct gdbarch
*gdbarch
)
1188 return (((can_use_displaced_stepping
== can_use_displaced_stepping_auto
1190 || can_use_displaced_stepping
== can_use_displaced_stepping_on
)
1191 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1192 && !RECORD_IS_USED
);
1195 /* Clean out any stray displaced stepping state. */
1197 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1199 /* Indicate that there is no cleanup pending. */
1200 displaced
->step_ptid
= null_ptid
;
1202 if (displaced
->step_closure
)
1204 gdbarch_displaced_step_free_closure (displaced
->step_gdbarch
,
1205 displaced
->step_closure
);
1206 displaced
->step_closure
= NULL
;
1211 displaced_step_clear_cleanup (void *arg
)
1213 struct displaced_step_inferior_state
*state
= arg
;
1215 displaced_step_clear (state
);
1218 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1220 displaced_step_dump_bytes (struct ui_file
*file
,
1221 const gdb_byte
*buf
,
1226 for (i
= 0; i
< len
; i
++)
1227 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1228 fputs_unfiltered ("\n", file
);
1231 /* Prepare to single-step, using displaced stepping.
1233 Note that we cannot use displaced stepping when we have a signal to
1234 deliver. If we have a signal to deliver and an instruction to step
1235 over, then after the step, there will be no indication from the
1236 target whether the thread entered a signal handler or ignored the
1237 signal and stepped over the instruction successfully --- both cases
1238 result in a simple SIGTRAP. In the first case we mustn't do a
1239 fixup, and in the second case we must --- but we can't tell which.
1240 Comments in the code for 'random signals' in handle_inferior_event
1241 explain how we handle this case instead.
1243 Returns 1 if preparing was successful -- this thread is going to be
1244 stepped now; or 0 if displaced stepping this thread got queued. */
1246 displaced_step_prepare (ptid_t ptid
)
1248 struct cleanup
*old_cleanups
, *ignore_cleanups
;
1249 struct regcache
*regcache
= get_thread_regcache (ptid
);
1250 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1251 CORE_ADDR original
, copy
;
1253 struct displaced_step_closure
*closure
;
1254 struct displaced_step_inferior_state
*displaced
;
1256 /* We should never reach this function if the architecture does not
1257 support displaced stepping. */
1258 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1260 /* We have to displaced step one thread at a time, as we only have
1261 access to a single scratch space per inferior. */
1263 displaced
= add_displaced_stepping_state (ptid_get_pid (ptid
));
1265 if (!ptid_equal (displaced
->step_ptid
, null_ptid
))
1267 /* Already waiting for a displaced step to finish. Defer this
1268 request and place in queue. */
1269 struct displaced_step_request
*req
, *new_req
;
1271 if (debug_displaced
)
1272 fprintf_unfiltered (gdb_stdlog
,
1273 "displaced: defering step of %s\n",
1274 target_pid_to_str (ptid
));
1276 new_req
= xmalloc (sizeof (*new_req
));
1277 new_req
->ptid
= ptid
;
1278 new_req
->next
= NULL
;
1280 if (displaced
->step_request_queue
)
1282 for (req
= displaced
->step_request_queue
;
1286 req
->next
= new_req
;
1289 displaced
->step_request_queue
= new_req
;
1295 if (debug_displaced
)
1296 fprintf_unfiltered (gdb_stdlog
,
1297 "displaced: stepping %s now\n",
1298 target_pid_to_str (ptid
));
1301 displaced_step_clear (displaced
);
1303 old_cleanups
= save_inferior_ptid ();
1304 inferior_ptid
= ptid
;
1306 original
= regcache_read_pc (regcache
);
1308 copy
= gdbarch_displaced_step_location (gdbarch
);
1309 len
= gdbarch_max_insn_length (gdbarch
);
1311 /* Save the original contents of the copy area. */
1312 displaced
->step_saved_copy
= xmalloc (len
);
1313 ignore_cleanups
= make_cleanup (free_current_contents
,
1314 &displaced
->step_saved_copy
);
1315 read_memory (copy
, displaced
->step_saved_copy
, len
);
1316 if (debug_displaced
)
1318 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1319 paddress (gdbarch
, copy
));
1320 displaced_step_dump_bytes (gdb_stdlog
,
1321 displaced
->step_saved_copy
,
1325 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1326 original
, copy
, regcache
);
1328 /* We don't support the fully-simulated case at present. */
1329 gdb_assert (closure
);
1331 /* Save the information we need to fix things up if the step
1333 displaced
->step_ptid
= ptid
;
1334 displaced
->step_gdbarch
= gdbarch
;
1335 displaced
->step_closure
= closure
;
1336 displaced
->step_original
= original
;
1337 displaced
->step_copy
= copy
;
1339 make_cleanup (displaced_step_clear_cleanup
, displaced
);
1341 /* Resume execution at the copy. */
1342 regcache_write_pc (regcache
, copy
);
1344 discard_cleanups (ignore_cleanups
);
1346 do_cleanups (old_cleanups
);
1348 if (debug_displaced
)
1349 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1350 paddress (gdbarch
, copy
));
1356 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1357 const gdb_byte
*myaddr
, int len
)
1359 struct cleanup
*ptid_cleanup
= save_inferior_ptid ();
1361 inferior_ptid
= ptid
;
1362 write_memory (memaddr
, myaddr
, len
);
1363 do_cleanups (ptid_cleanup
);
1367 displaced_step_fixup (ptid_t event_ptid
, enum target_signal signal
)
1369 struct cleanup
*old_cleanups
;
1370 struct displaced_step_inferior_state
*displaced
1371 = get_displaced_stepping_state (ptid_get_pid (event_ptid
));
1373 /* Was any thread of this process doing a displaced step? */
1374 if (displaced
== NULL
)
1377 /* Was this event for the pid we displaced? */
1378 if (ptid_equal (displaced
->step_ptid
, null_ptid
)
1379 || ! ptid_equal (displaced
->step_ptid
, event_ptid
))
1382 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, displaced
);
1384 /* Restore the contents of the copy area. */
1386 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1388 write_memory_ptid (displaced
->step_ptid
, displaced
->step_copy
,
1389 displaced
->step_saved_copy
, len
);
1390 if (debug_displaced
)
1391 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s\n",
1392 paddress (displaced
->step_gdbarch
,
1393 displaced
->step_copy
));
1396 /* Did the instruction complete successfully? */
1397 if (signal
== TARGET_SIGNAL_TRAP
)
1399 /* Fix up the resulting state. */
1400 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1401 displaced
->step_closure
,
1402 displaced
->step_original
,
1403 displaced
->step_copy
,
1404 get_thread_regcache (displaced
->step_ptid
));
1408 /* Since the instruction didn't complete, all we can do is
1410 struct regcache
*regcache
= get_thread_regcache (event_ptid
);
1411 CORE_ADDR pc
= regcache_read_pc (regcache
);
1413 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1414 regcache_write_pc (regcache
, pc
);
1417 do_cleanups (old_cleanups
);
1419 displaced
->step_ptid
= null_ptid
;
1421 /* Are there any pending displaced stepping requests? If so, run
1422 one now. Leave the state object around, since we're likely to
1423 need it again soon. */
1424 while (displaced
->step_request_queue
)
1426 struct displaced_step_request
*head
;
1428 struct regcache
*regcache
;
1429 struct gdbarch
*gdbarch
;
1430 CORE_ADDR actual_pc
;
1431 struct address_space
*aspace
;
1433 head
= displaced
->step_request_queue
;
1435 displaced
->step_request_queue
= head
->next
;
1438 context_switch (ptid
);
1440 regcache
= get_thread_regcache (ptid
);
1441 actual_pc
= regcache_read_pc (regcache
);
1442 aspace
= get_regcache_aspace (regcache
);
1444 if (breakpoint_here_p (aspace
, actual_pc
))
1446 if (debug_displaced
)
1447 fprintf_unfiltered (gdb_stdlog
,
1448 "displaced: stepping queued %s now\n",
1449 target_pid_to_str (ptid
));
1451 displaced_step_prepare (ptid
);
1453 gdbarch
= get_regcache_arch (regcache
);
1455 if (debug_displaced
)
1457 CORE_ADDR actual_pc
= regcache_read_pc (regcache
);
1460 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
1461 paddress (gdbarch
, actual_pc
));
1462 read_memory (actual_pc
, buf
, sizeof (buf
));
1463 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
1466 if (gdbarch_displaced_step_hw_singlestep (gdbarch
,
1467 displaced
->step_closure
))
1468 target_resume (ptid
, 1, TARGET_SIGNAL_0
);
1470 target_resume (ptid
, 0, TARGET_SIGNAL_0
);
1472 /* Done, we're stepping a thread. */
1478 struct thread_info
*tp
= inferior_thread ();
1480 /* The breakpoint we were sitting under has since been
1482 tp
->control
.trap_expected
= 0;
1484 /* Go back to what we were trying to do. */
1485 step
= currently_stepping (tp
);
1487 if (debug_displaced
)
1488 fprintf_unfiltered (gdb_stdlog
,
1489 "breakpoint is gone %s: step(%d)\n",
1490 target_pid_to_str (tp
->ptid
), step
);
1492 target_resume (ptid
, step
, TARGET_SIGNAL_0
);
1493 tp
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
1495 /* This request was discarded. See if there's any other
1496 thread waiting for its turn. */
1501 /* Update global variables holding ptids to hold NEW_PTID if they were
1502 holding OLD_PTID. */
1504 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
1506 struct displaced_step_request
*it
;
1507 struct displaced_step_inferior_state
*displaced
;
1509 if (ptid_equal (inferior_ptid
, old_ptid
))
1510 inferior_ptid
= new_ptid
;
1512 if (ptid_equal (singlestep_ptid
, old_ptid
))
1513 singlestep_ptid
= new_ptid
;
1515 if (ptid_equal (deferred_step_ptid
, old_ptid
))
1516 deferred_step_ptid
= new_ptid
;
1518 for (displaced
= displaced_step_inferior_states
;
1520 displaced
= displaced
->next
)
1522 if (ptid_equal (displaced
->step_ptid
, old_ptid
))
1523 displaced
->step_ptid
= new_ptid
;
1525 for (it
= displaced
->step_request_queue
; it
; it
= it
->next
)
1526 if (ptid_equal (it
->ptid
, old_ptid
))
1527 it
->ptid
= new_ptid
;
1534 /* Things to clean up if we QUIT out of resume (). */
1536 resume_cleanups (void *ignore
)
1541 static const char schedlock_off
[] = "off";
1542 static const char schedlock_on
[] = "on";
1543 static const char schedlock_step
[] = "step";
1544 static const char *scheduler_enums
[] = {
1550 static const char *scheduler_mode
= schedlock_off
;
1552 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
1553 struct cmd_list_element
*c
, const char *value
)
1555 fprintf_filtered (file
,
1556 _("Mode for locking scheduler "
1557 "during execution is \"%s\".\n"),
1562 set_schedlock_func (char *args
, int from_tty
, struct cmd_list_element
*c
)
1564 if (!target_can_lock_scheduler
)
1566 scheduler_mode
= schedlock_off
;
1567 error (_("Target '%s' cannot support this command."), target_shortname
);
1571 /* True if execution commands resume all threads of all processes by
1572 default; otherwise, resume only threads of the current inferior
1574 int sched_multi
= 0;
1576 /* Try to setup for software single stepping over the specified location.
1577 Return 1 if target_resume() should use hardware single step.
1579 GDBARCH the current gdbarch.
1580 PC the location to step over. */
1583 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
1587 if (execution_direction
== EXEC_FORWARD
1588 && gdbarch_software_single_step_p (gdbarch
)
1589 && gdbarch_software_single_step (gdbarch
, get_current_frame ()))
1592 /* Do not pull these breakpoints until after a `wait' in
1593 `wait_for_inferior'. */
1594 singlestep_breakpoints_inserted_p
= 1;
1595 singlestep_ptid
= inferior_ptid
;
1601 /* Return a ptid representing the set of threads that we will proceed,
1602 in the perspective of the user/frontend. We may actually resume
1603 fewer threads at first, e.g., if a thread is stopped at a
1604 breakpoint that needs stepping-off, but that should not be visible
1605 to the user/frontend, and neither should the frontend/user be
1606 allowed to proceed any of the threads that happen to be stopped for
1607 internal run control handling, if a previous command wanted them
1611 user_visible_resume_ptid (int step
)
1613 /* By default, resume all threads of all processes. */
1614 ptid_t resume_ptid
= RESUME_ALL
;
1616 /* Maybe resume only all threads of the current process. */
1617 if (!sched_multi
&& target_supports_multi_process ())
1619 resume_ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
1622 /* Maybe resume a single thread after all. */
1625 /* With non-stop mode on, threads are always handled
1627 resume_ptid
= inferior_ptid
;
1629 else if ((scheduler_mode
== schedlock_on
)
1630 || (scheduler_mode
== schedlock_step
1631 && (step
|| singlestep_breakpoints_inserted_p
)))
1633 /* User-settable 'scheduler' mode requires solo thread resume. */
1634 resume_ptid
= inferior_ptid
;
1640 /* Resume the inferior, but allow a QUIT. This is useful if the user
1641 wants to interrupt some lengthy single-stepping operation
1642 (for child processes, the SIGINT goes to the inferior, and so
1643 we get a SIGINT random_signal, but for remote debugging and perhaps
1644 other targets, that's not true).
1646 STEP nonzero if we should step (zero to continue instead).
1647 SIG is the signal to give the inferior (zero for none). */
1649 resume (int step
, enum target_signal sig
)
1651 int should_resume
= 1;
1652 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
1653 struct regcache
*regcache
= get_current_regcache ();
1654 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1655 struct thread_info
*tp
= inferior_thread ();
1656 CORE_ADDR pc
= regcache_read_pc (regcache
);
1657 struct address_space
*aspace
= get_regcache_aspace (regcache
);
1661 if (current_inferior ()->waiting_for_vfork_done
)
1663 /* Don't try to single-step a vfork parent that is waiting for
1664 the child to get out of the shared memory region (by exec'ing
1665 or exiting). This is particularly important on software
1666 single-step archs, as the child process would trip on the
1667 software single step breakpoint inserted for the parent
1668 process. Since the parent will not actually execute any
1669 instruction until the child is out of the shared region (such
1670 are vfork's semantics), it is safe to simply continue it.
1671 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
1672 the parent, and tell it to `keep_going', which automatically
1673 re-sets it stepping. */
1675 fprintf_unfiltered (gdb_stdlog
,
1676 "infrun: resume : clear step\n");
1681 fprintf_unfiltered (gdb_stdlog
,
1682 "infrun: resume (step=%d, signal=%d), "
1683 "trap_expected=%d, current thread [%s] at %s\n",
1684 step
, sig
, tp
->control
.trap_expected
,
1685 target_pid_to_str (inferior_ptid
),
1686 paddress (gdbarch
, pc
));
1688 /* Normally, by the time we reach `resume', the breakpoints are either
1689 removed or inserted, as appropriate. The exception is if we're sitting
1690 at a permanent breakpoint; we need to step over it, but permanent
1691 breakpoints can't be removed. So we have to test for it here. */
1692 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
1694 if (gdbarch_skip_permanent_breakpoint_p (gdbarch
))
1695 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
1698 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1699 how to step past a permanent breakpoint on this architecture. Try using\n\
1700 a command like `return' or `jump' to continue execution."));
1703 /* If enabled, step over breakpoints by executing a copy of the
1704 instruction at a different address.
1706 We can't use displaced stepping when we have a signal to deliver;
1707 the comments for displaced_step_prepare explain why. The
1708 comments in the handle_inferior event for dealing with 'random
1709 signals' explain what we do instead.
1711 We can't use displaced stepping when we are waiting for vfork_done
1712 event, displaced stepping breaks the vfork child similarly as single
1713 step software breakpoint. */
1714 if (use_displaced_stepping (gdbarch
)
1715 && (tp
->control
.trap_expected
1716 || (step
&& gdbarch_software_single_step_p (gdbarch
)))
1717 && sig
== TARGET_SIGNAL_0
1718 && !current_inferior ()->waiting_for_vfork_done
)
1720 struct displaced_step_inferior_state
*displaced
;
1722 if (!displaced_step_prepare (inferior_ptid
))
1724 /* Got placed in displaced stepping queue. Will be resumed
1725 later when all the currently queued displaced stepping
1726 requests finish. The thread is not executing at this point,
1727 and the call to set_executing will be made later. But we
1728 need to call set_running here, since from frontend point of view,
1729 the thread is running. */
1730 set_running (inferior_ptid
, 1);
1731 discard_cleanups (old_cleanups
);
1735 displaced
= get_displaced_stepping_state (ptid_get_pid (inferior_ptid
));
1736 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
1737 displaced
->step_closure
);
1740 /* Do we need to do it the hard way, w/temp breakpoints? */
1742 step
= maybe_software_singlestep (gdbarch
, pc
);
1744 /* Currently, our software single-step implementation leads to different
1745 results than hardware single-stepping in one situation: when stepping
1746 into delivering a signal which has an associated signal handler,
1747 hardware single-step will stop at the first instruction of the handler,
1748 while software single-step will simply skip execution of the handler.
1750 For now, this difference in behavior is accepted since there is no
1751 easy way to actually implement single-stepping into a signal handler
1752 without kernel support.
1754 However, there is one scenario where this difference leads to follow-on
1755 problems: if we're stepping off a breakpoint by removing all breakpoints
1756 and then single-stepping. In this case, the software single-step
1757 behavior means that even if there is a *breakpoint* in the signal
1758 handler, GDB still would not stop.
1760 Fortunately, we can at least fix this particular issue. We detect
1761 here the case where we are about to deliver a signal while software
1762 single-stepping with breakpoints removed. In this situation, we
1763 revert the decisions to remove all breakpoints and insert single-
1764 step breakpoints, and instead we install a step-resume breakpoint
1765 at the current address, deliver the signal without stepping, and
1766 once we arrive back at the step-resume breakpoint, actually step
1767 over the breakpoint we originally wanted to step over. */
1768 if (singlestep_breakpoints_inserted_p
1769 && tp
->control
.trap_expected
&& sig
!= TARGET_SIGNAL_0
)
1771 /* If we have nested signals or a pending signal is delivered
1772 immediately after a handler returns, might might already have
1773 a step-resume breakpoint set on the earlier handler. We cannot
1774 set another step-resume breakpoint; just continue on until the
1775 original breakpoint is hit. */
1776 if (tp
->control
.step_resume_breakpoint
== NULL
)
1778 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
1779 tp
->step_after_step_resume_breakpoint
= 1;
1782 remove_single_step_breakpoints ();
1783 singlestep_breakpoints_inserted_p
= 0;
1785 insert_breakpoints ();
1786 tp
->control
.trap_expected
= 0;
1793 /* If STEP is set, it's a request to use hardware stepping
1794 facilities. But in that case, we should never
1795 use singlestep breakpoint. */
1796 gdb_assert (!(singlestep_breakpoints_inserted_p
&& step
));
1798 /* Decide the set of threads to ask the target to resume. Start
1799 by assuming everything will be resumed, than narrow the set
1800 by applying increasingly restricting conditions. */
1801 resume_ptid
= user_visible_resume_ptid (step
);
1803 /* Maybe resume a single thread after all. */
1804 if (singlestep_breakpoints_inserted_p
1805 && stepping_past_singlestep_breakpoint
)
1807 /* The situation here is as follows. In thread T1 we wanted to
1808 single-step. Lacking hardware single-stepping we've
1809 set breakpoint at the PC of the next instruction -- call it
1810 P. After resuming, we've hit that breakpoint in thread T2.
1811 Now we've removed original breakpoint, inserted breakpoint
1812 at P+1, and try to step to advance T2 past breakpoint.
1813 We need to step only T2, as if T1 is allowed to freely run,
1814 it can run past P, and if other threads are allowed to run,
1815 they can hit breakpoint at P+1, and nested hits of single-step
1816 breakpoints is not something we'd want -- that's complicated
1817 to support, and has no value. */
1818 resume_ptid
= inferior_ptid
;
1820 else if ((step
|| singlestep_breakpoints_inserted_p
)
1821 && tp
->control
.trap_expected
)
1823 /* We're allowing a thread to run past a breakpoint it has
1824 hit, by single-stepping the thread with the breakpoint
1825 removed. In which case, we need to single-step only this
1826 thread, and keep others stopped, as they can miss this
1827 breakpoint if allowed to run.
1829 The current code actually removes all breakpoints when
1830 doing this, not just the one being stepped over, so if we
1831 let other threads run, we can actually miss any
1832 breakpoint, not just the one at PC. */
1833 resume_ptid
= inferior_ptid
;
1836 if (gdbarch_cannot_step_breakpoint (gdbarch
))
1838 /* Most targets can step a breakpoint instruction, thus
1839 executing it normally. But if this one cannot, just
1840 continue and we will hit it anyway. */
1841 if (step
&& breakpoint_inserted_here_p (aspace
, pc
))
1846 && use_displaced_stepping (gdbarch
)
1847 && tp
->control
.trap_expected
)
1849 struct regcache
*resume_regcache
= get_thread_regcache (resume_ptid
);
1850 struct gdbarch
*resume_gdbarch
= get_regcache_arch (resume_regcache
);
1851 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
1854 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
1855 paddress (resume_gdbarch
, actual_pc
));
1856 read_memory (actual_pc
, buf
, sizeof (buf
));
1857 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
1860 /* Install inferior's terminal modes. */
1861 target_terminal_inferior ();
1863 /* Avoid confusing the next resume, if the next stop/resume
1864 happens to apply to another thread. */
1865 tp
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
1867 /* Advise target which signals may be handled silently. If we have
1868 removed breakpoints because we are stepping over one (which can
1869 happen only if we are not using displaced stepping), we need to
1870 receive all signals to avoid accidentally skipping a breakpoint
1871 during execution of a signal handler. */
1872 if ((step
|| singlestep_breakpoints_inserted_p
)
1873 && tp
->control
.trap_expected
1874 && !use_displaced_stepping (gdbarch
))
1875 target_pass_signals (0, NULL
);
1877 target_pass_signals ((int) TARGET_SIGNAL_LAST
, signal_pass
);
1879 target_resume (resume_ptid
, step
, sig
);
1882 discard_cleanups (old_cleanups
);
1887 /* Clear out all variables saying what to do when inferior is continued.
1888 First do this, then set the ones you want, then call `proceed'. */
1891 clear_proceed_status_thread (struct thread_info
*tp
)
1894 fprintf_unfiltered (gdb_stdlog
,
1895 "infrun: clear_proceed_status_thread (%s)\n",
1896 target_pid_to_str (tp
->ptid
));
1898 tp
->control
.trap_expected
= 0;
1899 tp
->control
.step_range_start
= 0;
1900 tp
->control
.step_range_end
= 0;
1901 tp
->control
.step_frame_id
= null_frame_id
;
1902 tp
->control
.step_stack_frame_id
= null_frame_id
;
1903 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
1904 tp
->stop_requested
= 0;
1906 tp
->control
.stop_step
= 0;
1908 tp
->control
.proceed_to_finish
= 0;
1910 /* Discard any remaining commands or status from previous stop. */
1911 bpstat_clear (&tp
->control
.stop_bpstat
);
1915 clear_proceed_status_callback (struct thread_info
*tp
, void *data
)
1917 if (is_exited (tp
->ptid
))
1920 clear_proceed_status_thread (tp
);
1925 clear_proceed_status (void)
1929 /* In all-stop mode, delete the per-thread status of all
1930 threads, even if inferior_ptid is null_ptid, there may be
1931 threads on the list. E.g., we may be launching a new
1932 process, while selecting the executable. */
1933 iterate_over_threads (clear_proceed_status_callback
, NULL
);
1936 if (!ptid_equal (inferior_ptid
, null_ptid
))
1938 struct inferior
*inferior
;
1942 /* If in non-stop mode, only delete the per-thread status of
1943 the current thread. */
1944 clear_proceed_status_thread (inferior_thread ());
1947 inferior
= current_inferior ();
1948 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
1951 stop_after_trap
= 0;
1953 observer_notify_about_to_proceed ();
1957 regcache_xfree (stop_registers
);
1958 stop_registers
= NULL
;
1962 /* Check the current thread against the thread that reported the most recent
1963 event. If a step-over is required return TRUE and set the current thread
1964 to the old thread. Otherwise return FALSE.
1966 This should be suitable for any targets that support threads. */
1969 prepare_to_proceed (int step
)
1972 struct target_waitstatus wait_status
;
1973 int schedlock_enabled
;
1975 /* With non-stop mode on, threads are always handled individually. */
1976 gdb_assert (! non_stop
);
1978 /* Get the last target status returned by target_wait(). */
1979 get_last_target_status (&wait_ptid
, &wait_status
);
1981 /* Make sure we were stopped at a breakpoint. */
1982 if (wait_status
.kind
!= TARGET_WAITKIND_STOPPED
1983 || (wait_status
.value
.sig
!= TARGET_SIGNAL_TRAP
1984 && wait_status
.value
.sig
!= TARGET_SIGNAL_ILL
1985 && wait_status
.value
.sig
!= TARGET_SIGNAL_SEGV
1986 && wait_status
.value
.sig
!= TARGET_SIGNAL_EMT
))
1991 schedlock_enabled
= (scheduler_mode
== schedlock_on
1992 || (scheduler_mode
== schedlock_step
1995 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
1996 if (schedlock_enabled
)
1999 /* Don't switch over if we're about to resume some other process
2000 other than WAIT_PTID's, and schedule-multiple is off. */
2002 && ptid_get_pid (wait_ptid
) != ptid_get_pid (inferior_ptid
))
2005 /* Switched over from WAIT_PID. */
2006 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
2007 && !ptid_equal (inferior_ptid
, wait_ptid
))
2009 struct regcache
*regcache
= get_thread_regcache (wait_ptid
);
2011 if (breakpoint_here_p (get_regcache_aspace (regcache
),
2012 regcache_read_pc (regcache
)))
2014 /* If stepping, remember current thread to switch back to. */
2016 deferred_step_ptid
= inferior_ptid
;
2018 /* Switch back to WAIT_PID thread. */
2019 switch_to_thread (wait_ptid
);
2022 fprintf_unfiltered (gdb_stdlog
,
2023 "infrun: prepare_to_proceed (step=%d), "
2024 "switched to [%s]\n",
2025 step
, target_pid_to_str (inferior_ptid
));
2027 /* We return 1 to indicate that there is a breakpoint here,
2028 so we need to step over it before continuing to avoid
2029 hitting it straight away. */
2037 /* Basic routine for continuing the program in various fashions.
2039 ADDR is the address to resume at, or -1 for resume where stopped.
2040 SIGGNAL is the signal to give it, or 0 for none,
2041 or -1 for act according to how it stopped.
2042 STEP is nonzero if should trap after one instruction.
2043 -1 means return after that and print nothing.
2044 You should probably set various step_... variables
2045 before calling here, if you are stepping.
2047 You should call clear_proceed_status before calling proceed. */
2050 proceed (CORE_ADDR addr
, enum target_signal siggnal
, int step
)
2052 struct regcache
*regcache
;
2053 struct gdbarch
*gdbarch
;
2054 struct thread_info
*tp
;
2056 struct address_space
*aspace
;
2059 /* If we're stopped at a fork/vfork, follow the branch set by the
2060 "set follow-fork-mode" command; otherwise, we'll just proceed
2061 resuming the current thread. */
2062 if (!follow_fork ())
2064 /* The target for some reason decided not to resume. */
2066 if (target_can_async_p ())
2067 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2071 /* We'll update this if & when we switch to a new thread. */
2072 previous_inferior_ptid
= inferior_ptid
;
2074 regcache
= get_current_regcache ();
2075 gdbarch
= get_regcache_arch (regcache
);
2076 aspace
= get_regcache_aspace (regcache
);
2077 pc
= regcache_read_pc (regcache
);
2080 step_start_function
= find_pc_function (pc
);
2082 stop_after_trap
= 1;
2084 if (addr
== (CORE_ADDR
) -1)
2086 if (pc
== stop_pc
&& breakpoint_here_p (aspace
, pc
)
2087 && execution_direction
!= EXEC_REVERSE
)
2088 /* There is a breakpoint at the address we will resume at,
2089 step one instruction before inserting breakpoints so that
2090 we do not stop right away (and report a second hit at this
2093 Note, we don't do this in reverse, because we won't
2094 actually be executing the breakpoint insn anyway.
2095 We'll be (un-)executing the previous instruction. */
2098 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2099 && gdbarch_single_step_through_delay (gdbarch
,
2100 get_current_frame ()))
2101 /* We stepped onto an instruction that needs to be stepped
2102 again before re-inserting the breakpoint, do so. */
2107 regcache_write_pc (regcache
, addr
);
2111 fprintf_unfiltered (gdb_stdlog
,
2112 "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
2113 paddress (gdbarch
, addr
), siggnal
, step
);
2116 /* In non-stop, each thread is handled individually. The context
2117 must already be set to the right thread here. */
2121 /* In a multi-threaded task we may select another thread and
2122 then continue or step.
2124 But if the old thread was stopped at a breakpoint, it will
2125 immediately cause another breakpoint stop without any
2126 execution (i.e. it will report a breakpoint hit incorrectly).
2127 So we must step over it first.
2129 prepare_to_proceed checks the current thread against the
2130 thread that reported the most recent event. If a step-over
2131 is required it returns TRUE and sets the current thread to
2133 if (prepare_to_proceed (step
))
2137 /* prepare_to_proceed may change the current thread. */
2138 tp
= inferior_thread ();
2142 tp
->control
.trap_expected
= 1;
2143 /* If displaced stepping is enabled, we can step over the
2144 breakpoint without hitting it, so leave all breakpoints
2145 inserted. Otherwise we need to disable all breakpoints, step
2146 one instruction, and then re-add them when that step is
2148 if (!use_displaced_stepping (gdbarch
))
2149 remove_breakpoints ();
2152 /* We can insert breakpoints if we're not trying to step over one,
2153 or if we are stepping over one but we're using displaced stepping
2155 if (! tp
->control
.trap_expected
|| use_displaced_stepping (gdbarch
))
2156 insert_breakpoints ();
2160 /* Pass the last stop signal to the thread we're resuming,
2161 irrespective of whether the current thread is the thread that
2162 got the last event or not. This was historically GDB's
2163 behaviour before keeping a stop_signal per thread. */
2165 struct thread_info
*last_thread
;
2167 struct target_waitstatus last_status
;
2169 get_last_target_status (&last_ptid
, &last_status
);
2170 if (!ptid_equal (inferior_ptid
, last_ptid
)
2171 && !ptid_equal (last_ptid
, null_ptid
)
2172 && !ptid_equal (last_ptid
, minus_one_ptid
))
2174 last_thread
= find_thread_ptid (last_ptid
);
2177 tp
->suspend
.stop_signal
= last_thread
->suspend
.stop_signal
;
2178 last_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
2183 if (siggnal
!= TARGET_SIGNAL_DEFAULT
)
2184 tp
->suspend
.stop_signal
= siggnal
;
2185 /* If this signal should not be seen by program,
2186 give it zero. Used for debugging signals. */
2187 else if (!signal_program
[tp
->suspend
.stop_signal
])
2188 tp
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
2190 annotate_starting ();
2192 /* Make sure that output from GDB appears before output from the
2194 gdb_flush (gdb_stdout
);
2196 /* Refresh prev_pc value just prior to resuming. This used to be
2197 done in stop_stepping, however, setting prev_pc there did not handle
2198 scenarios such as inferior function calls or returning from
2199 a function via the return command. In those cases, the prev_pc
2200 value was not set properly for subsequent commands. The prev_pc value
2201 is used to initialize the starting line number in the ecs. With an
2202 invalid value, the gdb next command ends up stopping at the position
2203 represented by the next line table entry past our start position.
2204 On platforms that generate one line table entry per line, this
2205 is not a problem. However, on the ia64, the compiler generates
2206 extraneous line table entries that do not increase the line number.
2207 When we issue the gdb next command on the ia64 after an inferior call
2208 or a return command, we often end up a few instructions forward, still
2209 within the original line we started.
2211 An attempt was made to refresh the prev_pc at the same time the
2212 execution_control_state is initialized (for instance, just before
2213 waiting for an inferior event). But this approach did not work
2214 because of platforms that use ptrace, where the pc register cannot
2215 be read unless the inferior is stopped. At that point, we are not
2216 guaranteed the inferior is stopped and so the regcache_read_pc() call
2217 can fail. Setting the prev_pc value here ensures the value is updated
2218 correctly when the inferior is stopped. */
2219 tp
->prev_pc
= regcache_read_pc (get_current_regcache ());
2221 /* Fill in with reasonable starting values. */
2222 init_thread_stepping_state (tp
);
2224 /* Reset to normal state. */
2225 init_infwait_state ();
2227 /* Resume inferior. */
2228 resume (oneproc
|| step
|| bpstat_should_step (), tp
->suspend
.stop_signal
);
2230 /* Wait for it to stop (if not standalone)
2231 and in any case decode why it stopped, and act accordingly. */
2232 /* Do this only if we are not using the event loop, or if the target
2233 does not support asynchronous execution. */
2234 if (!target_can_async_p ())
2236 wait_for_inferior ();
2242 /* Start remote-debugging of a machine over a serial link. */
2245 start_remote (int from_tty
)
2247 struct inferior
*inferior
;
2249 init_wait_for_inferior ();
2250 inferior
= current_inferior ();
2251 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
2253 /* Always go on waiting for the target, regardless of the mode. */
2254 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2255 indicate to wait_for_inferior that a target should timeout if
2256 nothing is returned (instead of just blocking). Because of this,
2257 targets expecting an immediate response need to, internally, set
2258 things up so that the target_wait() is forced to eventually
2260 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2261 differentiate to its caller what the state of the target is after
2262 the initial open has been performed. Here we're assuming that
2263 the target has stopped. It should be possible to eventually have
2264 target_open() return to the caller an indication that the target
2265 is currently running and GDB state should be set to the same as
2266 for an async run. */
2267 wait_for_inferior ();
2269 /* Now that the inferior has stopped, do any bookkeeping like
2270 loading shared libraries. We want to do this before normal_stop,
2271 so that the displayed frame is up to date. */
2272 post_create_inferior (¤t_target
, from_tty
);
2277 /* Initialize static vars when a new inferior begins. */
2280 init_wait_for_inferior (void)
2282 /* These are meaningless until the first time through wait_for_inferior. */
2284 breakpoint_init_inferior (inf_starting
);
2286 clear_proceed_status ();
2288 stepping_past_singlestep_breakpoint
= 0;
2289 deferred_step_ptid
= null_ptid
;
2291 target_last_wait_ptid
= minus_one_ptid
;
2293 previous_inferior_ptid
= inferior_ptid
;
2294 init_infwait_state ();
2296 /* Discard any skipped inlined frames. */
2297 clear_inline_frame_state (minus_one_ptid
);
2301 /* This enum encodes possible reasons for doing a target_wait, so that
2302 wfi can call target_wait in one place. (Ultimately the call will be
2303 moved out of the infinite loop entirely.) */
2307 infwait_normal_state
,
2308 infwait_thread_hop_state
,
2309 infwait_step_watch_state
,
2310 infwait_nonstep_watch_state
2313 /* The PTID we'll do a target_wait on.*/
2316 /* Current inferior wait state. */
2317 enum infwait_states infwait_state
;
2319 /* Data to be passed around while handling an event. This data is
2320 discarded between events. */
2321 struct execution_control_state
2324 /* The thread that got the event, if this was a thread event; NULL
2326 struct thread_info
*event_thread
;
2328 struct target_waitstatus ws
;
2330 CORE_ADDR stop_func_start
;
2331 CORE_ADDR stop_func_end
;
2332 char *stop_func_name
;
2333 int new_thread_event
;
2337 static void handle_inferior_event (struct execution_control_state
*ecs
);
2339 static void handle_step_into_function (struct gdbarch
*gdbarch
,
2340 struct execution_control_state
*ecs
);
2341 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
2342 struct execution_control_state
*ecs
);
2343 static void check_exception_resume (struct execution_control_state
*,
2344 struct frame_info
*, struct symbol
*);
2346 static void stop_stepping (struct execution_control_state
*ecs
);
2347 static void prepare_to_wait (struct execution_control_state
*ecs
);
2348 static void keep_going (struct execution_control_state
*ecs
);
2350 /* Callback for iterate over threads. If the thread is stopped, but
2351 the user/frontend doesn't know about that yet, go through
2352 normal_stop, as if the thread had just stopped now. ARG points at
2353 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2354 ptid_is_pid(PTID) is true, applies to all threads of the process
2355 pointed at by PTID. Otherwise, apply only to the thread pointed by
2359 infrun_thread_stop_requested_callback (struct thread_info
*info
, void *arg
)
2361 ptid_t ptid
= * (ptid_t
*) arg
;
2363 if ((ptid_equal (info
->ptid
, ptid
)
2364 || ptid_equal (minus_one_ptid
, ptid
)
2365 || (ptid_is_pid (ptid
)
2366 && ptid_get_pid (ptid
) == ptid_get_pid (info
->ptid
)))
2367 && is_running (info
->ptid
)
2368 && !is_executing (info
->ptid
))
2370 struct cleanup
*old_chain
;
2371 struct execution_control_state ecss
;
2372 struct execution_control_state
*ecs
= &ecss
;
2374 memset (ecs
, 0, sizeof (*ecs
));
2376 old_chain
= make_cleanup_restore_current_thread ();
2378 switch_to_thread (info
->ptid
);
2380 /* Go through handle_inferior_event/normal_stop, so we always
2381 have consistent output as if the stop event had been
2383 ecs
->ptid
= info
->ptid
;
2384 ecs
->event_thread
= find_thread_ptid (info
->ptid
);
2385 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
2386 ecs
->ws
.value
.sig
= TARGET_SIGNAL_0
;
2388 handle_inferior_event (ecs
);
2390 if (!ecs
->wait_some_more
)
2392 struct thread_info
*tp
;
2396 /* Finish off the continuations. */
2397 tp
= inferior_thread ();
2398 do_all_intermediate_continuations_thread (tp
, 1);
2399 do_all_continuations_thread (tp
, 1);
2402 do_cleanups (old_chain
);
2408 /* This function is attached as a "thread_stop_requested" observer.
2409 Cleanup local state that assumed the PTID was to be resumed, and
2410 report the stop to the frontend. */
2413 infrun_thread_stop_requested (ptid_t ptid
)
2415 struct displaced_step_inferior_state
*displaced
;
2417 /* PTID was requested to stop. Remove it from the displaced
2418 stepping queue, so we don't try to resume it automatically. */
2420 for (displaced
= displaced_step_inferior_states
;
2422 displaced
= displaced
->next
)
2424 struct displaced_step_request
*it
, **prev_next_p
;
2426 it
= displaced
->step_request_queue
;
2427 prev_next_p
= &displaced
->step_request_queue
;
2430 if (ptid_match (it
->ptid
, ptid
))
2432 *prev_next_p
= it
->next
;
2438 prev_next_p
= &it
->next
;
2445 iterate_over_threads (infrun_thread_stop_requested_callback
, &ptid
);
2449 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
2451 if (ptid_equal (target_last_wait_ptid
, tp
->ptid
))
2452 nullify_last_target_wait_ptid ();
2455 /* Callback for iterate_over_threads. */
2458 delete_step_resume_breakpoint_callback (struct thread_info
*info
, void *data
)
2460 if (is_exited (info
->ptid
))
2463 delete_step_resume_breakpoint (info
);
2464 delete_exception_resume_breakpoint (info
);
2468 /* In all-stop, delete the step resume breakpoint of any thread that
2469 had one. In non-stop, delete the step resume breakpoint of the
2470 thread that just stopped. */
2473 delete_step_thread_step_resume_breakpoint (void)
2475 if (!target_has_execution
2476 || ptid_equal (inferior_ptid
, null_ptid
))
2477 /* If the inferior has exited, we have already deleted the step
2478 resume breakpoints out of GDB's lists. */
2483 /* If in non-stop mode, only delete the step-resume or
2484 longjmp-resume breakpoint of the thread that just stopped
2486 struct thread_info
*tp
= inferior_thread ();
2488 delete_step_resume_breakpoint (tp
);
2489 delete_exception_resume_breakpoint (tp
);
2492 /* In all-stop mode, delete all step-resume and longjmp-resume
2493 breakpoints of any thread that had them. */
2494 iterate_over_threads (delete_step_resume_breakpoint_callback
, NULL
);
2497 /* A cleanup wrapper. */
2500 delete_step_thread_step_resume_breakpoint_cleanup (void *arg
)
2502 delete_step_thread_step_resume_breakpoint ();
2505 /* Pretty print the results of target_wait, for debugging purposes. */
2508 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
2509 const struct target_waitstatus
*ws
)
2511 char *status_string
= target_waitstatus_to_string (ws
);
2512 struct ui_file
*tmp_stream
= mem_fileopen ();
2515 /* The text is split over several lines because it was getting too long.
2516 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2517 output as a unit; we want only one timestamp printed if debug_timestamp
2520 fprintf_unfiltered (tmp_stream
,
2521 "infrun: target_wait (%d", PIDGET (waiton_ptid
));
2522 if (PIDGET (waiton_ptid
) != -1)
2523 fprintf_unfiltered (tmp_stream
,
2524 " [%s]", target_pid_to_str (waiton_ptid
));
2525 fprintf_unfiltered (tmp_stream
, ", status) =\n");
2526 fprintf_unfiltered (tmp_stream
,
2527 "infrun: %d [%s],\n",
2528 PIDGET (result_ptid
), target_pid_to_str (result_ptid
));
2529 fprintf_unfiltered (tmp_stream
,
2533 text
= ui_file_xstrdup (tmp_stream
, NULL
);
2535 /* This uses %s in part to handle %'s in the text, but also to avoid
2536 a gcc error: the format attribute requires a string literal. */
2537 fprintf_unfiltered (gdb_stdlog
, "%s", text
);
2539 xfree (status_string
);
2541 ui_file_delete (tmp_stream
);
2544 /* Prepare and stabilize the inferior for detaching it. E.g.,
2545 detaching while a thread is displaced stepping is a recipe for
2546 crashing it, as nothing would readjust the PC out of the scratch
2550 prepare_for_detach (void)
2552 struct inferior
*inf
= current_inferior ();
2553 ptid_t pid_ptid
= pid_to_ptid (inf
->pid
);
2554 struct cleanup
*old_chain_1
;
2555 struct displaced_step_inferior_state
*displaced
;
2557 displaced
= get_displaced_stepping_state (inf
->pid
);
2559 /* Is any thread of this process displaced stepping? If not,
2560 there's nothing else to do. */
2561 if (displaced
== NULL
|| ptid_equal (displaced
->step_ptid
, null_ptid
))
2565 fprintf_unfiltered (gdb_stdlog
,
2566 "displaced-stepping in-process while detaching");
2568 old_chain_1
= make_cleanup_restore_integer (&inf
->detaching
);
2571 while (!ptid_equal (displaced
->step_ptid
, null_ptid
))
2573 struct cleanup
*old_chain_2
;
2574 struct execution_control_state ecss
;
2575 struct execution_control_state
*ecs
;
2578 memset (ecs
, 0, sizeof (*ecs
));
2580 overlay_cache_invalid
= 1;
2582 /* We have to invalidate the registers BEFORE calling
2583 target_wait because they can be loaded from the target while
2584 in target_wait. This makes remote debugging a bit more
2585 efficient for those targets that provide critical registers
2586 as part of their normal status mechanism. */
2588 registers_changed ();
2590 if (deprecated_target_wait_hook
)
2591 ecs
->ptid
= deprecated_target_wait_hook (pid_ptid
, &ecs
->ws
, 0);
2593 ecs
->ptid
= target_wait (pid_ptid
, &ecs
->ws
, 0);
2596 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
2598 /* If an error happens while handling the event, propagate GDB's
2599 knowledge of the executing state to the frontend/user running
2601 old_chain_2
= make_cleanup (finish_thread_state_cleanup
,
2604 /* In non-stop mode, each thread is handled individually.
2605 Switch early, so the global state is set correctly for this
2608 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2609 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
2610 context_switch (ecs
->ptid
);
2612 /* Now figure out what to do with the result of the result. */
2613 handle_inferior_event (ecs
);
2615 /* No error, don't finish the state yet. */
2616 discard_cleanups (old_chain_2
);
2618 /* Breakpoints and watchpoints are not installed on the target
2619 at this point, and signals are passed directly to the
2620 inferior, so this must mean the process is gone. */
2621 if (!ecs
->wait_some_more
)
2623 discard_cleanups (old_chain_1
);
2624 error (_("Program exited while detaching"));
2628 discard_cleanups (old_chain_1
);
2631 /* Wait for control to return from inferior to debugger.
2633 If inferior gets a signal, we may decide to start it up again
2634 instead of returning. That is why there is a loop in this function.
2635 When this function actually returns it means the inferior
2636 should be left stopped and GDB should read more commands. */
2639 wait_for_inferior (void)
2641 struct cleanup
*old_cleanups
;
2642 struct execution_control_state ecss
;
2643 struct execution_control_state
*ecs
;
2647 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
2650 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup
, NULL
);
2653 memset (ecs
, 0, sizeof (*ecs
));
2657 struct cleanup
*old_chain
;
2659 /* We have to invalidate the registers BEFORE calling target_wait
2660 because they can be loaded from the target while in target_wait.
2661 This makes remote debugging a bit more efficient for those
2662 targets that provide critical registers as part of their normal
2663 status mechanism. */
2665 overlay_cache_invalid
= 1;
2666 registers_changed ();
2668 if (deprecated_target_wait_hook
)
2669 ecs
->ptid
= deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, 0);
2671 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, 0);
2674 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
2676 /* If an error happens while handling the event, propagate GDB's
2677 knowledge of the executing state to the frontend/user running
2679 old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
2681 if (ecs
->ws
.kind
== TARGET_WAITKIND_SYSCALL_ENTRY
2682 || ecs
->ws
.kind
== TARGET_WAITKIND_SYSCALL_RETURN
)
2683 ecs
->ws
.value
.syscall_number
= UNKNOWN_SYSCALL
;
2685 /* Now figure out what to do with the result of the result. */
2686 handle_inferior_event (ecs
);
2688 /* No error, don't finish the state yet. */
2689 discard_cleanups (old_chain
);
2691 if (!ecs
->wait_some_more
)
2695 do_cleanups (old_cleanups
);
2698 /* Asynchronous version of wait_for_inferior. It is called by the
2699 event loop whenever a change of state is detected on the file
2700 descriptor corresponding to the target. It can be called more than
2701 once to complete a single execution command. In such cases we need
2702 to keep the state in a global variable ECSS. If it is the last time
2703 that this function is called for a single execution command, then
2704 report to the user that the inferior has stopped, and do the
2705 necessary cleanups. */
2708 fetch_inferior_event (void *client_data
)
2710 struct execution_control_state ecss
;
2711 struct execution_control_state
*ecs
= &ecss
;
2712 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
2713 struct cleanup
*ts_old_chain
;
2714 int was_sync
= sync_execution
;
2716 memset (ecs
, 0, sizeof (*ecs
));
2718 /* We're handling a live event, so make sure we're doing live
2719 debugging. If we're looking at traceframes while the target is
2720 running, we're going to need to get back to that mode after
2721 handling the event. */
2724 make_cleanup_restore_current_traceframe ();
2725 set_current_traceframe (-1);
2729 /* In non-stop mode, the user/frontend should not notice a thread
2730 switch due to internal events. Make sure we reverse to the
2731 user selected thread and frame after handling the event and
2732 running any breakpoint commands. */
2733 make_cleanup_restore_current_thread ();
2735 /* We have to invalidate the registers BEFORE calling target_wait
2736 because they can be loaded from the target while in target_wait.
2737 This makes remote debugging a bit more efficient for those
2738 targets that provide critical registers as part of their normal
2739 status mechanism. */
2741 overlay_cache_invalid
= 1;
2743 /* But don't do it if the current thread is already stopped (hence
2744 this is either a delayed event that will result in
2745 TARGET_WAITKIND_IGNORE, or it's an event for another thread (and
2746 we always clear the register and frame caches when the user
2747 switches threads anyway). If we didn't do this, a spurious
2748 delayed event in all-stop mode would make the user lose the
2750 if (non_stop
|| is_executing (inferior_ptid
))
2751 registers_changed ();
2753 make_cleanup_restore_integer (&execution_direction
);
2754 execution_direction
= target_execution_direction ();
2756 if (deprecated_target_wait_hook
)
2758 deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
2760 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
2763 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
2766 && ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
2767 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2768 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
2769 /* In non-stop mode, each thread is handled individually. Switch
2770 early, so the global state is set correctly for this
2772 context_switch (ecs
->ptid
);
2774 /* If an error happens while handling the event, propagate GDB's
2775 knowledge of the executing state to the frontend/user running
2778 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
2780 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &ecs
->ptid
);
2782 /* Now figure out what to do with the result of the result. */
2783 handle_inferior_event (ecs
);
2785 if (!ecs
->wait_some_more
)
2787 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
2789 delete_step_thread_step_resume_breakpoint ();
2791 /* We may not find an inferior if this was a process exit. */
2792 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
2795 if (target_has_execution
2796 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2797 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
2798 && ecs
->event_thread
->step_multi
2799 && ecs
->event_thread
->control
.stop_step
)
2800 inferior_event_handler (INF_EXEC_CONTINUE
, NULL
);
2802 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2805 /* No error, don't finish the thread states yet. */
2806 discard_cleanups (ts_old_chain
);
2808 /* Revert thread and frame. */
2809 do_cleanups (old_chain
);
2811 /* If the inferior was in sync execution mode, and now isn't,
2812 restore the prompt. */
2813 if (was_sync
&& !sync_execution
)
2814 display_gdb_prompt (0);
2817 /* Record the frame and location we're currently stepping through. */
2819 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
2821 struct thread_info
*tp
= inferior_thread ();
2823 tp
->control
.step_frame_id
= get_frame_id (frame
);
2824 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
2826 tp
->current_symtab
= sal
.symtab
;
2827 tp
->current_line
= sal
.line
;
2830 /* Clear context switchable stepping state. */
2833 init_thread_stepping_state (struct thread_info
*tss
)
2835 tss
->stepping_over_breakpoint
= 0;
2836 tss
->step_after_step_resume_breakpoint
= 0;
2837 tss
->stepping_through_solib_after_catch
= 0;
2838 tss
->stepping_through_solib_catchpoints
= NULL
;
2841 /* Return the cached copy of the last pid/waitstatus returned by
2842 target_wait()/deprecated_target_wait_hook(). The data is actually
2843 cached by handle_inferior_event(), which gets called immediately
2844 after target_wait()/deprecated_target_wait_hook(). */
2847 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
2849 *ptidp
= target_last_wait_ptid
;
2850 *status
= target_last_waitstatus
;
2854 nullify_last_target_wait_ptid (void)
2856 target_last_wait_ptid
= minus_one_ptid
;
2859 /* Switch thread contexts. */
2862 context_switch (ptid_t ptid
)
2866 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
2867 target_pid_to_str (inferior_ptid
));
2868 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
2869 target_pid_to_str (ptid
));
2872 switch_to_thread (ptid
);
2876 adjust_pc_after_break (struct execution_control_state
*ecs
)
2878 struct regcache
*regcache
;
2879 struct gdbarch
*gdbarch
;
2880 struct address_space
*aspace
;
2881 CORE_ADDR breakpoint_pc
;
2883 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2884 we aren't, just return.
2886 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2887 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2888 implemented by software breakpoints should be handled through the normal
2891 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2892 different signals (SIGILL or SIGEMT for instance), but it is less
2893 clear where the PC is pointing afterwards. It may not match
2894 gdbarch_decr_pc_after_break. I don't know any specific target that
2895 generates these signals at breakpoints (the code has been in GDB since at
2896 least 1992) so I can not guess how to handle them here.
2898 In earlier versions of GDB, a target with
2899 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2900 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2901 target with both of these set in GDB history, and it seems unlikely to be
2902 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2904 if (ecs
->ws
.kind
!= TARGET_WAITKIND_STOPPED
)
2907 if (ecs
->ws
.value
.sig
!= TARGET_SIGNAL_TRAP
)
2910 /* In reverse execution, when a breakpoint is hit, the instruction
2911 under it has already been de-executed. The reported PC always
2912 points at the breakpoint address, so adjusting it further would
2913 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2916 B1 0x08000000 : INSN1
2917 B2 0x08000001 : INSN2
2919 PC -> 0x08000003 : INSN4
2921 Say you're stopped at 0x08000003 as above. Reverse continuing
2922 from that point should hit B2 as below. Reading the PC when the
2923 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2924 been de-executed already.
2926 B1 0x08000000 : INSN1
2927 B2 PC -> 0x08000001 : INSN2
2931 We can't apply the same logic as for forward execution, because
2932 we would wrongly adjust the PC to 0x08000000, since there's a
2933 breakpoint at PC - 1. We'd then report a hit on B1, although
2934 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2936 if (execution_direction
== EXEC_REVERSE
)
2939 /* If this target does not decrement the PC after breakpoints, then
2940 we have nothing to do. */
2941 regcache
= get_thread_regcache (ecs
->ptid
);
2942 gdbarch
= get_regcache_arch (regcache
);
2943 if (gdbarch_decr_pc_after_break (gdbarch
) == 0)
2946 aspace
= get_regcache_aspace (regcache
);
2948 /* Find the location where (if we've hit a breakpoint) the
2949 breakpoint would be. */
2950 breakpoint_pc
= regcache_read_pc (regcache
)
2951 - gdbarch_decr_pc_after_break (gdbarch
);
2953 /* Check whether there actually is a software breakpoint inserted at
2956 If in non-stop mode, a race condition is possible where we've
2957 removed a breakpoint, but stop events for that breakpoint were
2958 already queued and arrive later. To suppress those spurious
2959 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
2960 and retire them after a number of stop events are reported. */
2961 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
2962 || (non_stop
&& moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
2964 struct cleanup
*old_cleanups
= NULL
;
2967 old_cleanups
= record_gdb_operation_disable_set ();
2969 /* When using hardware single-step, a SIGTRAP is reported for both
2970 a completed single-step and a software breakpoint. Need to
2971 differentiate between the two, as the latter needs adjusting
2972 but the former does not.
2974 The SIGTRAP can be due to a completed hardware single-step only if
2975 - we didn't insert software single-step breakpoints
2976 - the thread to be examined is still the current thread
2977 - this thread is currently being stepped
2979 If any of these events did not occur, we must have stopped due
2980 to hitting a software breakpoint, and have to back up to the
2983 As a special case, we could have hardware single-stepped a
2984 software breakpoint. In this case (prev_pc == breakpoint_pc),
2985 we also need to back up to the breakpoint address. */
2987 if (singlestep_breakpoints_inserted_p
2988 || !ptid_equal (ecs
->ptid
, inferior_ptid
)
2989 || !currently_stepping (ecs
->event_thread
)
2990 || ecs
->event_thread
->prev_pc
== breakpoint_pc
)
2991 regcache_write_pc (regcache
, breakpoint_pc
);
2994 do_cleanups (old_cleanups
);
2999 init_infwait_state (void)
3001 waiton_ptid
= pid_to_ptid (-1);
3002 infwait_state
= infwait_normal_state
;
3006 error_is_running (void)
3008 error (_("Cannot execute this command while "
3009 "the selected thread is running."));
3013 ensure_not_running (void)
3015 if (is_running (inferior_ptid
))
3016 error_is_running ();
3020 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
3022 for (frame
= get_prev_frame (frame
);
3024 frame
= get_prev_frame (frame
))
3026 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
3028 if (get_frame_type (frame
) != INLINE_FRAME
)
3035 /* Auxiliary function that handles syscall entry/return events.
3036 It returns 1 if the inferior should keep going (and GDB
3037 should ignore the event), or 0 if the event deserves to be
3041 handle_syscall_event (struct execution_control_state
*ecs
)
3043 struct regcache
*regcache
;
3044 struct gdbarch
*gdbarch
;
3047 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3048 context_switch (ecs
->ptid
);
3050 regcache
= get_thread_regcache (ecs
->ptid
);
3051 gdbarch
= get_regcache_arch (regcache
);
3052 syscall_number
= gdbarch_get_syscall_number (gdbarch
, ecs
->ptid
);
3053 stop_pc
= regcache_read_pc (regcache
);
3055 target_last_waitstatus
.value
.syscall_number
= syscall_number
;
3057 if (catch_syscall_enabled () > 0
3058 && catching_syscall_number (syscall_number
) > 0)
3061 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
3064 ecs
->event_thread
->control
.stop_bpstat
3065 = bpstat_stop_status (get_regcache_aspace (regcache
),
3066 stop_pc
, ecs
->ptid
);
3068 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
);
3070 if (!ecs
->random_signal
)
3072 /* Catchpoint hit. */
3073 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_TRAP
;
3078 /* If no catchpoint triggered for this, then keep going. */
3079 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3084 /* Given an execution control state that has been freshly filled in
3085 by an event from the inferior, figure out what it means and take
3086 appropriate action. */
3089 handle_inferior_event (struct execution_control_state
*ecs
)
3091 struct frame_info
*frame
;
3092 struct gdbarch
*gdbarch
;
3093 int stopped_by_watchpoint
;
3094 int stepped_after_stopped_by_watchpoint
= 0;
3095 struct symtab_and_line stop_pc_sal
;
3096 enum stop_kind stop_soon
;
3098 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
3100 /* We had an event in the inferior, but we are not interested in
3101 handling it at this level. The lower layers have already
3102 done what needs to be done, if anything.
3104 One of the possible circumstances for this is when the
3105 inferior produces output for the console. The inferior has
3106 not stopped, and we are ignoring the event. Another possible
3107 circumstance is any event which the lower level knows will be
3108 reported multiple times without an intervening resume. */
3110 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
3111 prepare_to_wait (ecs
);
3115 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
3116 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
3118 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
3121 stop_soon
= inf
->control
.stop_soon
;
3124 stop_soon
= NO_STOP_QUIETLY
;
3126 /* Cache the last pid/waitstatus. */
3127 target_last_wait_ptid
= ecs
->ptid
;
3128 target_last_waitstatus
= ecs
->ws
;
3130 /* Always clear state belonging to the previous time we stopped. */
3131 stop_stack_dummy
= STOP_NONE
;
3133 /* If it's a new process, add it to the thread database. */
3135 ecs
->new_thread_event
= (!ptid_equal (ecs
->ptid
, inferior_ptid
)
3136 && !ptid_equal (ecs
->ptid
, minus_one_ptid
)
3137 && !in_thread_list (ecs
->ptid
));
3139 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
3140 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
&& ecs
->new_thread_event
)
3141 add_thread (ecs
->ptid
);
3143 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
3145 /* Dependent on valid ECS->EVENT_THREAD. */
3146 adjust_pc_after_break (ecs
);
3148 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3149 reinit_frame_cache ();
3151 breakpoint_retire_moribund ();
3153 /* First, distinguish signals caused by the debugger from signals
3154 that have to do with the program's own actions. Note that
3155 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3156 on the operating system version. Here we detect when a SIGILL or
3157 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3158 something similar for SIGSEGV, since a SIGSEGV will be generated
3159 when we're trying to execute a breakpoint instruction on a
3160 non-executable stack. This happens for call dummy breakpoints
3161 for architectures like SPARC that place call dummies on the
3163 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
3164 && (ecs
->ws
.value
.sig
== TARGET_SIGNAL_ILL
3165 || ecs
->ws
.value
.sig
== TARGET_SIGNAL_SEGV
3166 || ecs
->ws
.value
.sig
== TARGET_SIGNAL_EMT
))
3168 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3170 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
3171 regcache_read_pc (regcache
)))
3174 fprintf_unfiltered (gdb_stdlog
,
3175 "infrun: Treating signal as SIGTRAP\n");
3176 ecs
->ws
.value
.sig
= TARGET_SIGNAL_TRAP
;
3180 /* Mark the non-executing threads accordingly. In all-stop, all
3181 threads of all processes are stopped when we get any event
3182 reported. In non-stop mode, only the event thread stops. If
3183 we're handling a process exit in non-stop mode, there's nothing
3184 to do, as threads of the dead process are gone, and threads of
3185 any other process were left running. */
3187 set_executing (minus_one_ptid
, 0);
3188 else if (ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
3189 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
)
3190 set_executing (inferior_ptid
, 0);
3192 switch (infwait_state
)
3194 case infwait_thread_hop_state
:
3196 fprintf_unfiltered (gdb_stdlog
, "infrun: infwait_thread_hop_state\n");
3199 case infwait_normal_state
:
3201 fprintf_unfiltered (gdb_stdlog
, "infrun: infwait_normal_state\n");
3204 case infwait_step_watch_state
:
3206 fprintf_unfiltered (gdb_stdlog
,
3207 "infrun: infwait_step_watch_state\n");
3209 stepped_after_stopped_by_watchpoint
= 1;
3212 case infwait_nonstep_watch_state
:
3214 fprintf_unfiltered (gdb_stdlog
,
3215 "infrun: infwait_nonstep_watch_state\n");
3216 insert_breakpoints ();
3218 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3219 handle things like signals arriving and other things happening
3220 in combination correctly? */
3221 stepped_after_stopped_by_watchpoint
= 1;
3225 internal_error (__FILE__
, __LINE__
, _("bad switch"));
3228 infwait_state
= infwait_normal_state
;
3229 waiton_ptid
= pid_to_ptid (-1);
3231 switch (ecs
->ws
.kind
)
3233 case TARGET_WAITKIND_LOADED
:
3235 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
3236 /* Ignore gracefully during startup of the inferior, as it might
3237 be the shell which has just loaded some objects, otherwise
3238 add the symbols for the newly loaded objects. Also ignore at
3239 the beginning of an attach or remote session; we will query
3240 the full list of libraries once the connection is
3242 if (stop_soon
== NO_STOP_QUIETLY
)
3244 /* Check for any newly added shared libraries if we're
3245 supposed to be adding them automatically. Switch
3246 terminal for any messages produced by
3247 breakpoint_re_set. */
3248 target_terminal_ours_for_output ();
3249 /* NOTE: cagney/2003-11-25: Make certain that the target
3250 stack's section table is kept up-to-date. Architectures,
3251 (e.g., PPC64), use the section table to perform
3252 operations such as address => section name and hence
3253 require the table to contain all sections (including
3254 those found in shared libraries). */
3256 SOLIB_ADD (NULL
, 0, ¤t_target
, auto_solib_add
);
3258 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
3260 target_terminal_inferior ();
3262 /* If requested, stop when the dynamic linker notifies
3263 gdb of events. This allows the user to get control
3264 and place breakpoints in initializer routines for
3265 dynamically loaded objects (among other things). */
3266 if (stop_on_solib_events
)
3268 /* Make sure we print "Stopped due to solib-event" in
3270 stop_print_frame
= 1;
3272 stop_stepping (ecs
);
3276 /* NOTE drow/2007-05-11: This might be a good place to check
3277 for "catch load". */
3280 /* If we are skipping through a shell, or through shared library
3281 loading that we aren't interested in, resume the program. If
3282 we're running the program normally, also resume. But stop if
3283 we're attaching or setting up a remote connection. */
3284 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
3286 /* Loading of shared libraries might have changed breakpoint
3287 addresses. Make sure new breakpoints are inserted. */
3288 if (stop_soon
== NO_STOP_QUIETLY
3289 && !breakpoints_always_inserted_mode ())
3290 insert_breakpoints ();
3291 resume (0, TARGET_SIGNAL_0
);
3292 prepare_to_wait (ecs
);
3298 case TARGET_WAITKIND_SPURIOUS
:
3300 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3301 resume (0, TARGET_SIGNAL_0
);
3302 prepare_to_wait (ecs
);
3305 case TARGET_WAITKIND_EXITED
:
3307 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXITED\n");
3308 inferior_ptid
= ecs
->ptid
;
3309 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs
->ptid
)));
3310 set_current_program_space (current_inferior ()->pspace
);
3311 handle_vfork_child_exec_or_exit (0);
3312 target_terminal_ours (); /* Must do this before mourn anyway. */
3313 print_exited_reason (ecs
->ws
.value
.integer
);
3315 /* Record the exit code in the convenience variable $_exitcode, so
3316 that the user can inspect this again later. */
3317 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3318 (LONGEST
) ecs
->ws
.value
.integer
);
3320 /* Also record this in the inferior itself. */
3321 current_inferior ()->has_exit_code
= 1;
3322 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
3324 gdb_flush (gdb_stdout
);
3325 target_mourn_inferior ();
3326 singlestep_breakpoints_inserted_p
= 0;
3327 cancel_single_step_breakpoints ();
3328 stop_print_frame
= 0;
3329 stop_stepping (ecs
);
3332 case TARGET_WAITKIND_SIGNALLED
:
3334 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SIGNALLED\n");
3335 inferior_ptid
= ecs
->ptid
;
3336 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs
->ptid
)));
3337 set_current_program_space (current_inferior ()->pspace
);
3338 handle_vfork_child_exec_or_exit (0);
3339 stop_print_frame
= 0;
3340 target_terminal_ours (); /* Must do this before mourn anyway. */
3342 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't
3343 reach here unless the inferior is dead. However, for years
3344 target_kill() was called here, which hints that fatal signals aren't
3345 really fatal on some systems. If that's true, then some changes
3347 target_mourn_inferior ();
3349 print_signal_exited_reason (ecs
->ws
.value
.sig
);
3350 singlestep_breakpoints_inserted_p
= 0;
3351 cancel_single_step_breakpoints ();
3352 stop_stepping (ecs
);
3355 /* The following are the only cases in which we keep going;
3356 the above cases end in a continue or goto. */
3357 case TARGET_WAITKIND_FORKED
:
3358 case TARGET_WAITKIND_VFORKED
:
3360 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
3362 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3364 context_switch (ecs
->ptid
);
3365 reinit_frame_cache ();
3368 /* Immediately detach breakpoints from the child before there's
3369 any chance of letting the user delete breakpoints from the
3370 breakpoint lists. If we don't do this early, it's easy to
3371 leave left over traps in the child, vis: "break foo; catch
3372 fork; c; <fork>; del; c; <child calls foo>". We only follow
3373 the fork on the last `continue', and by that time the
3374 breakpoint at "foo" is long gone from the breakpoint table.
3375 If we vforked, then we don't need to unpatch here, since both
3376 parent and child are sharing the same memory pages; we'll
3377 need to unpatch at follow/detach time instead to be certain
3378 that new breakpoints added between catchpoint hit time and
3379 vfork follow are detached. */
3380 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
3382 int child_pid
= ptid_get_pid (ecs
->ws
.value
.related_pid
);
3384 /* This won't actually modify the breakpoint list, but will
3385 physically remove the breakpoints from the child. */
3386 detach_breakpoints (child_pid
);
3389 if (singlestep_breakpoints_inserted_p
)
3391 /* Pull the single step breakpoints out of the target. */
3392 remove_single_step_breakpoints ();
3393 singlestep_breakpoints_inserted_p
= 0;
3396 /* In case the event is caught by a catchpoint, remember that
3397 the event is to be followed at the next resume of the thread,
3398 and not immediately. */
3399 ecs
->event_thread
->pending_follow
= ecs
->ws
;
3401 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
3403 ecs
->event_thread
->control
.stop_bpstat
3404 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3405 stop_pc
, ecs
->ptid
);
3407 /* Note that we're interested in knowing the bpstat actually
3408 causes a stop, not just if it may explain the signal.
3409 Software watchpoints, for example, always appear in the
3412 = !bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
);
3414 /* If no catchpoint triggered for this, then keep going. */
3415 if (ecs
->random_signal
)
3421 = (follow_fork_mode_string
== follow_fork_mode_child
);
3423 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3425 should_resume
= follow_fork ();
3428 child
= ecs
->ws
.value
.related_pid
;
3430 /* In non-stop mode, also resume the other branch. */
3431 if (non_stop
&& !detach_fork
)
3434 switch_to_thread (parent
);
3436 switch_to_thread (child
);
3438 ecs
->event_thread
= inferior_thread ();
3439 ecs
->ptid
= inferior_ptid
;
3444 switch_to_thread (child
);
3446 switch_to_thread (parent
);
3448 ecs
->event_thread
= inferior_thread ();
3449 ecs
->ptid
= inferior_ptid
;
3454 stop_stepping (ecs
);
3457 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_TRAP
;
3458 goto process_event_stop_test
;
3460 case TARGET_WAITKIND_VFORK_DONE
:
3461 /* Done with the shared memory region. Re-insert breakpoints in
3462 the parent, and keep going. */
3465 fprintf_unfiltered (gdb_stdlog
,
3466 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3468 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3469 context_switch (ecs
->ptid
);
3471 current_inferior ()->waiting_for_vfork_done
= 0;
3472 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
3473 /* This also takes care of reinserting breakpoints in the
3474 previously locked inferior. */
3478 case TARGET_WAITKIND_EXECD
:
3480 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
3482 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3484 context_switch (ecs
->ptid
);
3485 reinit_frame_cache ();
3488 singlestep_breakpoints_inserted_p
= 0;
3489 cancel_single_step_breakpoints ();
3491 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
3493 /* Do whatever is necessary to the parent branch of the vfork. */
3494 handle_vfork_child_exec_or_exit (1);
3496 /* This causes the eventpoints and symbol table to be reset.
3497 Must do this now, before trying to determine whether to
3499 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
3501 ecs
->event_thread
->control
.stop_bpstat
3502 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3503 stop_pc
, ecs
->ptid
);
3505 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
);
3507 /* Note that this may be referenced from inside
3508 bpstat_stop_status above, through inferior_has_execd. */
3509 xfree (ecs
->ws
.value
.execd_pathname
);
3510 ecs
->ws
.value
.execd_pathname
= NULL
;
3512 /* If no catchpoint triggered for this, then keep going. */
3513 if (ecs
->random_signal
)
3515 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3519 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_TRAP
;
3520 goto process_event_stop_test
;
3522 /* Be careful not to try to gather much state about a thread
3523 that's in a syscall. It's frequently a losing proposition. */
3524 case TARGET_WAITKIND_SYSCALL_ENTRY
:
3526 fprintf_unfiltered (gdb_stdlog
,
3527 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3528 /* Getting the current syscall number. */
3529 if (handle_syscall_event (ecs
) != 0)
3531 goto process_event_stop_test
;
3533 /* Before examining the threads further, step this thread to
3534 get it entirely out of the syscall. (We get notice of the
3535 event when the thread is just on the verge of exiting a
3536 syscall. Stepping one instruction seems to get it back
3538 case TARGET_WAITKIND_SYSCALL_RETURN
:
3540 fprintf_unfiltered (gdb_stdlog
,
3541 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3542 if (handle_syscall_event (ecs
) != 0)
3544 goto process_event_stop_test
;
3546 case TARGET_WAITKIND_STOPPED
:
3548 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
3549 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
3552 case TARGET_WAITKIND_NO_HISTORY
:
3553 /* Reverse execution: target ran out of history info. */
3554 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
3555 print_no_history_reason ();
3556 stop_stepping (ecs
);
3560 if (ecs
->new_thread_event
)
3563 /* Non-stop assumes that the target handles adding new threads
3564 to the thread list. */
3565 internal_error (__FILE__
, __LINE__
,
3566 "targets should add new threads to the thread "
3567 "list themselves in non-stop mode.");
3569 /* We may want to consider not doing a resume here in order to
3570 give the user a chance to play with the new thread. It might
3571 be good to make that a user-settable option. */
3573 /* At this point, all threads are stopped (happens automatically
3574 in either the OS or the native code). Therefore we need to
3575 continue all threads in order to make progress. */
3577 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3578 context_switch (ecs
->ptid
);
3579 target_resume (RESUME_ALL
, 0, TARGET_SIGNAL_0
);
3580 prepare_to_wait (ecs
);
3584 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
)
3586 /* Do we need to clean up the state of a thread that has
3587 completed a displaced single-step? (Doing so usually affects
3588 the PC, so do it here, before we set stop_pc.) */
3589 displaced_step_fixup (ecs
->ptid
,
3590 ecs
->event_thread
->suspend
.stop_signal
);
3592 /* If we either finished a single-step or hit a breakpoint, but
3593 the user wanted this thread to be stopped, pretend we got a
3594 SIG0 (generic unsignaled stop). */
3596 if (ecs
->event_thread
->stop_requested
3597 && ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
3598 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3601 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
3605 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3606 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3607 struct cleanup
*old_chain
= save_inferior_ptid ();
3609 inferior_ptid
= ecs
->ptid
;
3611 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
3612 paddress (gdbarch
, stop_pc
));
3613 if (target_stopped_by_watchpoint ())
3617 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
3619 if (target_stopped_data_address (¤t_target
, &addr
))
3620 fprintf_unfiltered (gdb_stdlog
,
3621 "infrun: stopped data address = %s\n",
3622 paddress (gdbarch
, addr
));
3624 fprintf_unfiltered (gdb_stdlog
,
3625 "infrun: (no data address available)\n");
3628 do_cleanups (old_chain
);
3631 if (stepping_past_singlestep_breakpoint
)
3633 gdb_assert (singlestep_breakpoints_inserted_p
);
3634 gdb_assert (ptid_equal (singlestep_ptid
, ecs
->ptid
));
3635 gdb_assert (!ptid_equal (singlestep_ptid
, saved_singlestep_ptid
));
3637 stepping_past_singlestep_breakpoint
= 0;
3639 /* We've either finished single-stepping past the single-step
3640 breakpoint, or stopped for some other reason. It would be nice if
3641 we could tell, but we can't reliably. */
3642 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
3645 fprintf_unfiltered (gdb_stdlog
,
3646 "infrun: stepping_past_"
3647 "singlestep_breakpoint\n");
3648 /* Pull the single step breakpoints out of the target. */
3649 remove_single_step_breakpoints ();
3650 singlestep_breakpoints_inserted_p
= 0;
3652 ecs
->random_signal
= 0;
3653 ecs
->event_thread
->control
.trap_expected
= 0;
3655 context_switch (saved_singlestep_ptid
);
3656 if (deprecated_context_hook
)
3657 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
3659 resume (1, TARGET_SIGNAL_0
);
3660 prepare_to_wait (ecs
);
3665 if (!ptid_equal (deferred_step_ptid
, null_ptid
))
3667 /* In non-stop mode, there's never a deferred_step_ptid set. */
3668 gdb_assert (!non_stop
);
3670 /* If we stopped for some other reason than single-stepping, ignore
3671 the fact that we were supposed to switch back. */
3672 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
3675 fprintf_unfiltered (gdb_stdlog
,
3676 "infrun: handling deferred step\n");
3678 /* Pull the single step breakpoints out of the target. */
3679 if (singlestep_breakpoints_inserted_p
)
3681 remove_single_step_breakpoints ();
3682 singlestep_breakpoints_inserted_p
= 0;
3685 ecs
->event_thread
->control
.trap_expected
= 0;
3687 /* Note: We do not call context_switch at this point, as the
3688 context is already set up for stepping the original thread. */
3689 switch_to_thread (deferred_step_ptid
);
3690 deferred_step_ptid
= null_ptid
;
3691 /* Suppress spurious "Switching to ..." message. */
3692 previous_inferior_ptid
= inferior_ptid
;
3694 resume (1, TARGET_SIGNAL_0
);
3695 prepare_to_wait (ecs
);
3699 deferred_step_ptid
= null_ptid
;
3702 /* See if a thread hit a thread-specific breakpoint that was meant for
3703 another thread. If so, then step that thread past the breakpoint,
3706 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
3708 int thread_hop_needed
= 0;
3709 struct address_space
*aspace
=
3710 get_regcache_aspace (get_thread_regcache (ecs
->ptid
));
3712 /* Check if a regular breakpoint has been hit before checking
3713 for a potential single step breakpoint. Otherwise, GDB will
3714 not see this breakpoint hit when stepping onto breakpoints. */
3715 if (regular_breakpoint_inserted_here_p (aspace
, stop_pc
))
3717 ecs
->random_signal
= 0;
3718 if (!breakpoint_thread_match (aspace
, stop_pc
, ecs
->ptid
))
3719 thread_hop_needed
= 1;
3721 else if (singlestep_breakpoints_inserted_p
)
3723 /* We have not context switched yet, so this should be true
3724 no matter which thread hit the singlestep breakpoint. */
3725 gdb_assert (ptid_equal (inferior_ptid
, singlestep_ptid
));
3727 fprintf_unfiltered (gdb_stdlog
, "infrun: software single step "
3729 target_pid_to_str (ecs
->ptid
));
3731 ecs
->random_signal
= 0;
3732 /* The call to in_thread_list is necessary because PTIDs sometimes
3733 change when we go from single-threaded to multi-threaded. If
3734 the singlestep_ptid is still in the list, assume that it is
3735 really different from ecs->ptid. */
3736 if (!ptid_equal (singlestep_ptid
, ecs
->ptid
)
3737 && in_thread_list (singlestep_ptid
))
3739 /* If the PC of the thread we were trying to single-step
3740 has changed, discard this event (which we were going
3741 to ignore anyway), and pretend we saw that thread
3742 trap. This prevents us continuously moving the
3743 single-step breakpoint forward, one instruction at a
3744 time. If the PC has changed, then the thread we were
3745 trying to single-step has trapped or been signalled,
3746 but the event has not been reported to GDB yet.
3748 There might be some cases where this loses signal
3749 information, if a signal has arrived at exactly the
3750 same time that the PC changed, but this is the best
3751 we can do with the information available. Perhaps we
3752 should arrange to report all events for all threads
3753 when they stop, or to re-poll the remote looking for
3754 this particular thread (i.e. temporarily enable
3757 CORE_ADDR new_singlestep_pc
3758 = regcache_read_pc (get_thread_regcache (singlestep_ptid
));
3760 if (new_singlestep_pc
!= singlestep_pc
)
3762 enum target_signal stop_signal
;
3765 fprintf_unfiltered (gdb_stdlog
, "infrun: unexpected thread,"
3766 " but expected thread advanced also\n");
3768 /* The current context still belongs to
3769 singlestep_ptid. Don't swap here, since that's
3770 the context we want to use. Just fudge our
3771 state and continue. */
3772 stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
3773 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3774 ecs
->ptid
= singlestep_ptid
;
3775 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
3776 ecs
->event_thread
->suspend
.stop_signal
= stop_signal
;
3777 stop_pc
= new_singlestep_pc
;
3782 fprintf_unfiltered (gdb_stdlog
,
3783 "infrun: unexpected thread\n");
3785 thread_hop_needed
= 1;
3786 stepping_past_singlestep_breakpoint
= 1;
3787 saved_singlestep_ptid
= singlestep_ptid
;
3792 if (thread_hop_needed
)
3794 struct regcache
*thread_regcache
;
3795 int remove_status
= 0;
3798 fprintf_unfiltered (gdb_stdlog
, "infrun: thread_hop_needed\n");
3800 /* Switch context before touching inferior memory, the
3801 previous thread may have exited. */
3802 if (!ptid_equal (inferior_ptid
, ecs
->ptid
))
3803 context_switch (ecs
->ptid
);
3805 /* Saw a breakpoint, but it was hit by the wrong thread.
3808 if (singlestep_breakpoints_inserted_p
)
3810 /* Pull the single step breakpoints out of the target. */
3811 remove_single_step_breakpoints ();
3812 singlestep_breakpoints_inserted_p
= 0;
3815 /* If the arch can displace step, don't remove the
3817 thread_regcache
= get_thread_regcache (ecs
->ptid
);
3818 if (!use_displaced_stepping (get_regcache_arch (thread_regcache
)))
3819 remove_status
= remove_breakpoints ();
3821 /* Did we fail to remove breakpoints? If so, try
3822 to set the PC past the bp. (There's at least
3823 one situation in which we can fail to remove
3824 the bp's: On HP-UX's that use ttrace, we can't
3825 change the address space of a vforking child
3826 process until the child exits (well, okay, not
3827 then either :-) or execs. */
3828 if (remove_status
!= 0)
3829 error (_("Cannot step over breakpoint hit in wrong thread"));
3834 /* Only need to require the next event from this
3835 thread in all-stop mode. */
3836 waiton_ptid
= ecs
->ptid
;
3837 infwait_state
= infwait_thread_hop_state
;
3840 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3845 else if (singlestep_breakpoints_inserted_p
)
3847 ecs
->random_signal
= 0;
3851 ecs
->random_signal
= 1;
3853 /* See if something interesting happened to the non-current thread. If
3854 so, then switch to that thread. */
3855 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3858 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
3860 context_switch (ecs
->ptid
);
3862 if (deprecated_context_hook
)
3863 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
3866 /* At this point, get hold of the now-current thread's frame. */
3867 frame
= get_current_frame ();
3868 gdbarch
= get_frame_arch (frame
);
3870 if (singlestep_breakpoints_inserted_p
)
3872 /* Pull the single step breakpoints out of the target. */
3873 remove_single_step_breakpoints ();
3874 singlestep_breakpoints_inserted_p
= 0;
3877 if (stepped_after_stopped_by_watchpoint
)
3878 stopped_by_watchpoint
= 0;
3880 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
3882 /* If necessary, step over this watchpoint. We'll be back to display
3884 if (stopped_by_watchpoint
3885 && (target_have_steppable_watchpoint
3886 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
3888 /* At this point, we are stopped at an instruction which has
3889 attempted to write to a piece of memory under control of
3890 a watchpoint. The instruction hasn't actually executed
3891 yet. If we were to evaluate the watchpoint expression
3892 now, we would get the old value, and therefore no change
3893 would seem to have occurred.
3895 In order to make watchpoints work `right', we really need
3896 to complete the memory write, and then evaluate the
3897 watchpoint expression. We do this by single-stepping the
3900 It may not be necessary to disable the watchpoint to stop over
3901 it. For example, the PA can (with some kernel cooperation)
3902 single step over a watchpoint without disabling the watchpoint.
3904 It is far more common to need to disable a watchpoint to step
3905 the inferior over it. If we have non-steppable watchpoints,
3906 we must disable the current watchpoint; it's simplest to
3907 disable all watchpoints and breakpoints. */
3910 if (!target_have_steppable_watchpoint
)
3912 remove_breakpoints ();
3913 /* See comment in resume why we need to stop bypassing signals
3914 while breakpoints have been removed. */
3915 target_pass_signals (0, NULL
);
3918 hw_step
= maybe_software_singlestep (gdbarch
, stop_pc
);
3919 target_resume (ecs
->ptid
, hw_step
, TARGET_SIGNAL_0
);
3920 waiton_ptid
= ecs
->ptid
;
3921 if (target_have_steppable_watchpoint
)
3922 infwait_state
= infwait_step_watch_state
;
3924 infwait_state
= infwait_nonstep_watch_state
;
3925 prepare_to_wait (ecs
);
3929 ecs
->stop_func_start
= 0;
3930 ecs
->stop_func_end
= 0;
3931 ecs
->stop_func_name
= 0;
3932 /* Don't care about return value; stop_func_start and stop_func_name
3933 will both be 0 if it doesn't work. */
3934 find_pc_partial_function (stop_pc
, &ecs
->stop_func_name
,
3935 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
3936 ecs
->stop_func_start
3937 += gdbarch_deprecated_function_start_offset (gdbarch
);
3938 ecs
->event_thread
->stepping_over_breakpoint
= 0;
3939 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
3940 ecs
->event_thread
->control
.stop_step
= 0;
3941 stop_print_frame
= 1;
3942 ecs
->random_signal
= 0;
3943 stopped_by_random_signal
= 0;
3945 /* Hide inlined functions starting here, unless we just performed stepi or
3946 nexti. After stepi and nexti, always show the innermost frame (not any
3947 inline function call sites). */
3948 if (ecs
->event_thread
->control
.step_range_end
!= 1)
3949 skip_inline_frames (ecs
->ptid
);
3951 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
3952 && ecs
->event_thread
->control
.trap_expected
3953 && gdbarch_single_step_through_delay_p (gdbarch
)
3954 && currently_stepping (ecs
->event_thread
))
3956 /* We're trying to step off a breakpoint. Turns out that we're
3957 also on an instruction that needs to be stepped multiple
3958 times before it's been fully executing. E.g., architectures
3959 with a delay slot. It needs to be stepped twice, once for
3960 the instruction and once for the delay slot. */
3961 int step_through_delay
3962 = gdbarch_single_step_through_delay (gdbarch
, frame
);
3964 if (debug_infrun
&& step_through_delay
)
3965 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
3966 if (ecs
->event_thread
->control
.step_range_end
== 0
3967 && step_through_delay
)
3969 /* The user issued a continue when stopped at a breakpoint.
3970 Set up for another trap and get out of here. */
3971 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3975 else if (step_through_delay
)
3977 /* The user issued a step when stopped at a breakpoint.
3978 Maybe we should stop, maybe we should not - the delay
3979 slot *might* correspond to a line of source. In any
3980 case, don't decide that here, just set
3981 ecs->stepping_over_breakpoint, making sure we
3982 single-step again before breakpoints are re-inserted. */
3983 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3987 /* Look at the cause of the stop, and decide what to do.
3988 The alternatives are:
3989 1) stop_stepping and return; to really stop and return to the debugger,
3990 2) keep_going and return to start up again
3991 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
3992 3) set ecs->random_signal to 1, and the decision between 1 and 2
3993 will be made according to the signal handling tables. */
3995 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
3996 || stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_NO_SIGSTOP
3997 || stop_soon
== STOP_QUIETLY_REMOTE
)
3999 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
4003 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
4004 stop_print_frame
= 0;
4005 stop_stepping (ecs
);
4009 /* This is originated from start_remote(), start_inferior() and
4010 shared libraries hook functions. */
4011 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
4014 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4015 stop_stepping (ecs
);
4019 /* This originates from attach_command(). We need to overwrite
4020 the stop_signal here, because some kernels don't ignore a
4021 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4022 See more comments in inferior.h. On the other hand, if we
4023 get a non-SIGSTOP, report it to the user - assume the backend
4024 will handle the SIGSTOP if it should show up later.
4026 Also consider that the attach is complete when we see a
4027 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4028 target extended-remote report it instead of a SIGSTOP
4029 (e.g. gdbserver). We already rely on SIGTRAP being our
4030 signal, so this is no exception.
4032 Also consider that the attach is complete when we see a
4033 TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4034 the target to stop all threads of the inferior, in case the
4035 low level attach operation doesn't stop them implicitly. If
4036 they weren't stopped implicitly, then the stub will report a
4037 TARGET_SIGNAL_0, meaning: stopped for no particular reason
4038 other than GDB's request. */
4039 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4040 && (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_STOP
4041 || ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
4042 || ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_0
))
4044 stop_stepping (ecs
);
4045 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
4049 /* See if there is a breakpoint at the current PC. */
4050 ecs
->event_thread
->control
.stop_bpstat
4051 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4052 stop_pc
, ecs
->ptid
);
4054 /* Following in case break condition called a
4056 stop_print_frame
= 1;
4058 /* This is where we handle "moribund" watchpoints. Unlike
4059 software breakpoints traps, hardware watchpoint traps are
4060 always distinguishable from random traps. If no high-level
4061 watchpoint is associated with the reported stop data address
4062 anymore, then the bpstat does not explain the signal ---
4063 simply make sure to ignore it if `stopped_by_watchpoint' is
4067 && ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
4068 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
)
4069 && stopped_by_watchpoint
)
4070 fprintf_unfiltered (gdb_stdlog
,
4071 "infrun: no user watchpoint explains "
4072 "watchpoint SIGTRAP, ignoring\n");
4074 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4075 at one stage in the past included checks for an inferior
4076 function call's call dummy's return breakpoint. The original
4077 comment, that went with the test, read:
4079 ``End of a stack dummy. Some systems (e.g. Sony news) give
4080 another signal besides SIGTRAP, so check here as well as
4083 If someone ever tries to get call dummys on a
4084 non-executable stack to work (where the target would stop
4085 with something like a SIGSEGV), then those tests might need
4086 to be re-instated. Given, however, that the tests were only
4087 enabled when momentary breakpoints were not being used, I
4088 suspect that it won't be the case.
4090 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4091 be necessary for call dummies on a non-executable stack on
4094 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
4096 = !(bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
)
4097 || stopped_by_watchpoint
4098 || ecs
->event_thread
->control
.trap_expected
4099 || (ecs
->event_thread
->control
.step_range_end
4100 && (ecs
->event_thread
->control
.step_resume_breakpoint
4104 ecs
->random_signal
= !bpstat_explains_signal
4105 (ecs
->event_thread
->control
.stop_bpstat
);
4106 if (!ecs
->random_signal
)
4107 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_TRAP
;
4111 /* When we reach this point, we've pretty much decided
4112 that the reason for stopping must've been a random
4113 (unexpected) signal. */
4116 ecs
->random_signal
= 1;
4118 process_event_stop_test
:
4120 /* Re-fetch current thread's frame in case we did a
4121 "goto process_event_stop_test" above. */
4122 frame
= get_current_frame ();
4123 gdbarch
= get_frame_arch (frame
);
4125 /* For the program's own signals, act according to
4126 the signal handling tables. */
4128 if (ecs
->random_signal
)
4130 /* Signal not for debugging purposes. */
4132 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
4135 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal %d\n",
4136 ecs
->event_thread
->suspend
.stop_signal
);
4138 stopped_by_random_signal
= 1;
4140 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
4143 target_terminal_ours_for_output ();
4144 print_signal_received_reason
4145 (ecs
->event_thread
->suspend
.stop_signal
);
4147 /* Always stop on signals if we're either just gaining control
4148 of the program, or the user explicitly requested this thread
4149 to remain stopped. */
4150 if (stop_soon
!= NO_STOP_QUIETLY
4151 || ecs
->event_thread
->stop_requested
4153 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
4155 stop_stepping (ecs
);
4158 /* If not going to stop, give terminal back
4159 if we took it away. */
4161 target_terminal_inferior ();
4163 /* Clear the signal if it should not be passed. */
4164 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
4165 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
4167 if (ecs
->event_thread
->prev_pc
== stop_pc
4168 && ecs
->event_thread
->control
.trap_expected
4169 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
4171 /* We were just starting a new sequence, attempting to
4172 single-step off of a breakpoint and expecting a SIGTRAP.
4173 Instead this signal arrives. This signal will take us out
4174 of the stepping range so GDB needs to remember to, when
4175 the signal handler returns, resume stepping off that
4177 /* To simplify things, "continue" is forced to use the same
4178 code paths as single-step - set a breakpoint at the
4179 signal return address and then, once hit, step off that
4182 fprintf_unfiltered (gdb_stdlog
,
4183 "infrun: signal arrived while stepping over "
4186 insert_hp_step_resume_breakpoint_at_frame (frame
);
4187 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
4188 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4189 ecs
->event_thread
->control
.trap_expected
= 0;
4194 if (ecs
->event_thread
->control
.step_range_end
!= 0
4195 && ecs
->event_thread
->suspend
.stop_signal
!= TARGET_SIGNAL_0
4196 && (ecs
->event_thread
->control
.step_range_start
<= stop_pc
4197 && stop_pc
< ecs
->event_thread
->control
.step_range_end
)
4198 && frame_id_eq (get_stack_frame_id (frame
),
4199 ecs
->event_thread
->control
.step_stack_frame_id
)
4200 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
4202 /* The inferior is about to take a signal that will take it
4203 out of the single step range. Set a breakpoint at the
4204 current PC (which is presumably where the signal handler
4205 will eventually return) and then allow the inferior to
4208 Note that this is only needed for a signal delivered
4209 while in the single-step range. Nested signals aren't a
4210 problem as they eventually all return. */
4212 fprintf_unfiltered (gdb_stdlog
,
4213 "infrun: signal may take us out of "
4214 "single-step range\n");
4216 insert_hp_step_resume_breakpoint_at_frame (frame
);
4217 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4218 ecs
->event_thread
->control
.trap_expected
= 0;
4223 /* Note: step_resume_breakpoint may be non-NULL. This occures
4224 when either there's a nested signal, or when there's a
4225 pending signal enabled just as the signal handler returns
4226 (leaving the inferior at the step-resume-breakpoint without
4227 actually executing it). Either way continue until the
4228 breakpoint is really hit. */
4233 /* Handle cases caused by hitting a breakpoint. */
4235 CORE_ADDR jmp_buf_pc
;
4236 struct bpstat_what what
;
4238 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
4240 if (what
.call_dummy
)
4242 stop_stack_dummy
= what
.call_dummy
;
4245 /* If we hit an internal event that triggers symbol changes, the
4246 current frame will be invalidated within bpstat_what (e.g., if
4247 we hit an internal solib event). Re-fetch it. */
4248 frame
= get_current_frame ();
4249 gdbarch
= get_frame_arch (frame
);
4251 switch (what
.main_action
)
4253 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
4254 /* If we hit the breakpoint at longjmp while stepping, we
4255 install a momentary breakpoint at the target of the
4259 fprintf_unfiltered (gdb_stdlog
,
4260 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4262 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4264 if (what
.is_longjmp
)
4266 if (!gdbarch_get_longjmp_target_p (gdbarch
)
4267 || !gdbarch_get_longjmp_target (gdbarch
,
4268 frame
, &jmp_buf_pc
))
4271 fprintf_unfiltered (gdb_stdlog
,
4272 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4273 "(!gdbarch_get_longjmp_target)\n");
4278 /* We're going to replace the current step-resume breakpoint
4279 with a longjmp-resume breakpoint. */
4280 delete_step_resume_breakpoint (ecs
->event_thread
);
4282 /* Insert a breakpoint at resume address. */
4283 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
4287 struct symbol
*func
= get_frame_function (frame
);
4290 check_exception_resume (ecs
, frame
, func
);
4295 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
4297 fprintf_unfiltered (gdb_stdlog
,
4298 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4300 if (what
.is_longjmp
)
4302 gdb_assert (ecs
->event_thread
->control
.step_resume_breakpoint
4304 delete_step_resume_breakpoint (ecs
->event_thread
);
4308 /* There are several cases to consider.
4310 1. The initiating frame no longer exists. In this case
4311 we must stop, because the exception has gone too far.
4313 2. The initiating frame exists, and is the same as the
4314 current frame. We stop, because the exception has been
4317 3. The initiating frame exists and is different from
4318 the current frame. This means the exception has been
4319 caught beneath the initiating frame, so keep going. */
4320 struct frame_info
*init_frame
4321 = frame_find_by_id (ecs
->event_thread
->initiating_frame
);
4323 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
4325 delete_exception_resume_breakpoint (ecs
->event_thread
);
4329 struct frame_id current_id
4330 = get_frame_id (get_current_frame ());
4331 if (frame_id_eq (current_id
,
4332 ecs
->event_thread
->initiating_frame
))
4334 /* Case 2. Fall through. */
4344 /* For Cases 1 and 2, remove the step-resume breakpoint,
4346 delete_step_resume_breakpoint (ecs
->event_thread
);
4349 ecs
->event_thread
->control
.stop_step
= 1;
4350 print_end_stepping_range_reason ();
4351 stop_stepping (ecs
);
4354 case BPSTAT_WHAT_SINGLE
:
4356 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
4357 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4358 /* Still need to check other stuff, at least the case
4359 where we are stepping and step out of the right range. */
4362 case BPSTAT_WHAT_STEP_RESUME
:
4364 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4366 delete_step_resume_breakpoint (ecs
->event_thread
);
4367 if (ecs
->event_thread
->control
.proceed_to_finish
4368 && execution_direction
== EXEC_REVERSE
)
4370 struct thread_info
*tp
= ecs
->event_thread
;
4372 /* We are finishing a function in reverse, and just hit
4373 the step-resume breakpoint at the start address of the
4374 function, and we're almost there -- just need to back
4375 up by one more single-step, which should take us back
4376 to the function call. */
4377 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
4381 if (stop_pc
== ecs
->stop_func_start
4382 && execution_direction
== EXEC_REVERSE
)
4384 /* We are stepping over a function call in reverse, and
4385 just hit the step-resume breakpoint at the start
4386 address of the function. Go back to single-stepping,
4387 which should take us back to the function call. */
4388 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4394 case BPSTAT_WHAT_STOP_NOISY
:
4396 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4397 stop_print_frame
= 1;
4399 /* We are about to nuke the step_resume_breakpointt via the
4400 cleanup chain, so no need to worry about it here. */
4402 stop_stepping (ecs
);
4405 case BPSTAT_WHAT_STOP_SILENT
:
4407 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4408 stop_print_frame
= 0;
4410 /* We are about to nuke the step_resume_breakpoin via the
4411 cleanup chain, so no need to worry about it here. */
4413 stop_stepping (ecs
);
4416 case BPSTAT_WHAT_HP_STEP_RESUME
:
4418 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4420 delete_step_resume_breakpoint (ecs
->event_thread
);
4421 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
4423 /* Back when the step-resume breakpoint was inserted, we
4424 were trying to single-step off a breakpoint. Go back
4426 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
4427 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4433 case BPSTAT_WHAT_KEEP_CHECKING
:
4438 /* We come here if we hit a breakpoint but should not
4439 stop for it. Possibly we also were stepping
4440 and should stop for that. So fall through and
4441 test for stepping. But, if not stepping,
4444 /* In all-stop mode, if we're currently stepping but have stopped in
4445 some other thread, we need to switch back to the stepped thread. */
4448 struct thread_info
*tp
;
4450 tp
= iterate_over_threads (currently_stepping_or_nexting_callback
,
4454 /* However, if the current thread is blocked on some internal
4455 breakpoint, and we simply need to step over that breakpoint
4456 to get it going again, do that first. */
4457 if ((ecs
->event_thread
->control
.trap_expected
4458 && ecs
->event_thread
->suspend
.stop_signal
!= TARGET_SIGNAL_TRAP
)
4459 || ecs
->event_thread
->stepping_over_breakpoint
)
4465 /* If the stepping thread exited, then don't try to switch
4466 back and resume it, which could fail in several different
4467 ways depending on the target. Instead, just keep going.
4469 We can find a stepping dead thread in the thread list in
4472 - The target supports thread exit events, and when the
4473 target tries to delete the thread from the thread list,
4474 inferior_ptid pointed at the exiting thread. In such
4475 case, calling delete_thread does not really remove the
4476 thread from the list; instead, the thread is left listed,
4477 with 'exited' state.
4479 - The target's debug interface does not support thread
4480 exit events, and so we have no idea whatsoever if the
4481 previously stepping thread is still alive. For that
4482 reason, we need to synchronously query the target
4484 if (is_exited (tp
->ptid
)
4485 || !target_thread_alive (tp
->ptid
))
4488 fprintf_unfiltered (gdb_stdlog
,
4489 "infrun: not switching back to "
4490 "stepped thread, it has vanished\n");
4492 delete_thread (tp
->ptid
);
4497 /* Otherwise, we no longer expect a trap in the current thread.
4498 Clear the trap_expected flag before switching back -- this is
4499 what keep_going would do as well, if we called it. */
4500 ecs
->event_thread
->control
.trap_expected
= 0;
4503 fprintf_unfiltered (gdb_stdlog
,
4504 "infrun: switching back to stepped thread\n");
4506 ecs
->event_thread
= tp
;
4507 ecs
->ptid
= tp
->ptid
;
4508 context_switch (ecs
->ptid
);
4514 /* Are we stepping to get the inferior out of the dynamic linker's
4515 hook (and possibly the dld itself) after catching a shlib
4517 if (ecs
->event_thread
->stepping_through_solib_after_catch
)
4519 #if defined(SOLIB_ADD)
4520 /* Have we reached our destination? If not, keep going. */
4521 if (SOLIB_IN_DYNAMIC_LINKER (PIDGET (ecs
->ptid
), stop_pc
))
4524 fprintf_unfiltered (gdb_stdlog
,
4525 "infrun: stepping in dynamic linker\n");
4526 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4532 fprintf_unfiltered (gdb_stdlog
, "infrun: step past dynamic linker\n");
4533 /* Else, stop and report the catchpoint(s) whose triggering
4534 caused us to begin stepping. */
4535 ecs
->event_thread
->stepping_through_solib_after_catch
= 0;
4536 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
4537 ecs
->event_thread
->control
.stop_bpstat
4538 = bpstat_copy (ecs
->event_thread
->stepping_through_solib_catchpoints
);
4539 bpstat_clear (&ecs
->event_thread
->stepping_through_solib_catchpoints
);
4540 stop_print_frame
= 1;
4541 stop_stepping (ecs
);
4545 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
4548 fprintf_unfiltered (gdb_stdlog
,
4549 "infrun: step-resume breakpoint is inserted\n");
4551 /* Having a step-resume breakpoint overrides anything
4552 else having to do with stepping commands until
4553 that breakpoint is reached. */
4558 if (ecs
->event_thread
->control
.step_range_end
== 0)
4561 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
4562 /* Likewise if we aren't even stepping. */
4567 /* Re-fetch current thread's frame in case the code above caused
4568 the frame cache to be re-initialized, making our FRAME variable
4569 a dangling pointer. */
4570 frame
= get_current_frame ();
4571 gdbarch
= get_frame_arch (frame
);
4573 /* If stepping through a line, keep going if still within it.
4575 Note that step_range_end is the address of the first instruction
4576 beyond the step range, and NOT the address of the last instruction
4579 Note also that during reverse execution, we may be stepping
4580 through a function epilogue and therefore must detect when
4581 the current-frame changes in the middle of a line. */
4583 if (stop_pc
>= ecs
->event_thread
->control
.step_range_start
4584 && stop_pc
< ecs
->event_thread
->control
.step_range_end
4585 && (execution_direction
!= EXEC_REVERSE
4586 || frame_id_eq (get_frame_id (frame
),
4587 ecs
->event_thread
->control
.step_frame_id
)))
4591 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
4592 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
4593 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
4595 /* When stepping backward, stop at beginning of line range
4596 (unless it's the function entry point, in which case
4597 keep going back to the call point). */
4598 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
4599 && stop_pc
!= ecs
->stop_func_start
4600 && execution_direction
== EXEC_REVERSE
)
4602 ecs
->event_thread
->control
.stop_step
= 1;
4603 print_end_stepping_range_reason ();
4604 stop_stepping (ecs
);
4612 /* We stepped out of the stepping range. */
4614 /* If we are stepping at the source level and entered the runtime
4615 loader dynamic symbol resolution code...
4617 EXEC_FORWARD: we keep on single stepping until we exit the run
4618 time loader code and reach the callee's address.
4620 EXEC_REVERSE: we've already executed the callee (backward), and
4621 the runtime loader code is handled just like any other
4622 undebuggable function call. Now we need only keep stepping
4623 backward through the trampoline code, and that's handled further
4624 down, so there is nothing for us to do here. */
4626 if (execution_direction
!= EXEC_REVERSE
4627 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
4628 && in_solib_dynsym_resolve_code (stop_pc
))
4630 CORE_ADDR pc_after_resolver
=
4631 gdbarch_skip_solib_resolver (gdbarch
, stop_pc
);
4634 fprintf_unfiltered (gdb_stdlog
,
4635 "infrun: stepped into dynsym resolve code\n");
4637 if (pc_after_resolver
)
4639 /* Set up a step-resume breakpoint at the address
4640 indicated by SKIP_SOLIB_RESOLVER. */
4641 struct symtab_and_line sr_sal
;
4644 sr_sal
.pc
= pc_after_resolver
;
4645 sr_sal
.pspace
= get_frame_program_space (frame
);
4647 insert_step_resume_breakpoint_at_sal (gdbarch
,
4648 sr_sal
, null_frame_id
);
4655 if (ecs
->event_thread
->control
.step_range_end
!= 1
4656 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
4657 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
4658 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
4661 fprintf_unfiltered (gdb_stdlog
,
4662 "infrun: stepped into signal trampoline\n");
4663 /* The inferior, while doing a "step" or "next", has ended up in
4664 a signal trampoline (either by a signal being delivered or by
4665 the signal handler returning). Just single-step until the
4666 inferior leaves the trampoline (either by calling the handler
4672 /* Check for subroutine calls. The check for the current frame
4673 equalling the step ID is not necessary - the check of the
4674 previous frame's ID is sufficient - but it is a common case and
4675 cheaper than checking the previous frame's ID.
4677 NOTE: frame_id_eq will never report two invalid frame IDs as
4678 being equal, so to get into this block, both the current and
4679 previous frame must have valid frame IDs. */
4680 /* The outer_frame_id check is a heuristic to detect stepping
4681 through startup code. If we step over an instruction which
4682 sets the stack pointer from an invalid value to a valid value,
4683 we may detect that as a subroutine call from the mythical
4684 "outermost" function. This could be fixed by marking
4685 outermost frames as !stack_p,code_p,special_p. Then the
4686 initial outermost frame, before sp was valid, would
4687 have code_addr == &_start. See the comment in frame_id_eq
4689 if (!frame_id_eq (get_stack_frame_id (frame
),
4690 ecs
->event_thread
->control
.step_stack_frame_id
)
4691 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4692 ecs
->event_thread
->control
.step_stack_frame_id
)
4693 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
4695 || step_start_function
!= find_pc_function (stop_pc
))))
4697 CORE_ADDR real_stop_pc
;
4700 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
4702 if ((ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
4703 || ((ecs
->event_thread
->control
.step_range_end
== 1)
4704 && in_prologue (gdbarch
, ecs
->event_thread
->prev_pc
,
4705 ecs
->stop_func_start
)))
4707 /* I presume that step_over_calls is only 0 when we're
4708 supposed to be stepping at the assembly language level
4709 ("stepi"). Just stop. */
4710 /* Also, maybe we just did a "nexti" inside a prolog, so we
4711 thought it was a subroutine call but it was not. Stop as
4713 /* And this works the same backward as frontward. MVS */
4714 ecs
->event_thread
->control
.stop_step
= 1;
4715 print_end_stepping_range_reason ();
4716 stop_stepping (ecs
);
4720 /* Reverse stepping through solib trampolines. */
4722 if (execution_direction
== EXEC_REVERSE
4723 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
4724 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
4725 || (ecs
->stop_func_start
== 0
4726 && in_solib_dynsym_resolve_code (stop_pc
))))
4728 /* Any solib trampoline code can be handled in reverse
4729 by simply continuing to single-step. We have already
4730 executed the solib function (backwards), and a few
4731 steps will take us back through the trampoline to the
4737 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
4739 /* We're doing a "next".
4741 Normal (forward) execution: set a breakpoint at the
4742 callee's return address (the address at which the caller
4745 Reverse (backward) execution. set the step-resume
4746 breakpoint at the start of the function that we just
4747 stepped into (backwards), and continue to there. When we
4748 get there, we'll need to single-step back to the caller. */
4750 if (execution_direction
== EXEC_REVERSE
)
4752 struct symtab_and_line sr_sal
;
4754 /* Normal function call return (static or dynamic). */
4756 sr_sal
.pc
= ecs
->stop_func_start
;
4757 sr_sal
.pspace
= get_frame_program_space (frame
);
4758 insert_step_resume_breakpoint_at_sal (gdbarch
,
4759 sr_sal
, null_frame_id
);
4762 insert_step_resume_breakpoint_at_caller (frame
);
4768 /* If we are in a function call trampoline (a stub between the
4769 calling routine and the real function), locate the real
4770 function. That's what tells us (a) whether we want to step
4771 into it at all, and (b) what prologue we want to run to the
4772 end of, if we do step into it. */
4773 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
4774 if (real_stop_pc
== 0)
4775 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
4776 if (real_stop_pc
!= 0)
4777 ecs
->stop_func_start
= real_stop_pc
;
4779 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
4781 struct symtab_and_line sr_sal
;
4784 sr_sal
.pc
= ecs
->stop_func_start
;
4785 sr_sal
.pspace
= get_frame_program_space (frame
);
4787 insert_step_resume_breakpoint_at_sal (gdbarch
,
4788 sr_sal
, null_frame_id
);
4793 /* If we have line number information for the function we are
4794 thinking of stepping into, step into it.
4796 If there are several symtabs at that PC (e.g. with include
4797 files), just want to know whether *any* of them have line
4798 numbers. find_pc_line handles this. */
4800 struct symtab_and_line tmp_sal
;
4802 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
4803 if (tmp_sal
.line
!= 0)
4805 if (execution_direction
== EXEC_REVERSE
)
4806 handle_step_into_function_backward (gdbarch
, ecs
);
4808 handle_step_into_function (gdbarch
, ecs
);
4813 /* If we have no line number and the step-stop-if-no-debug is
4814 set, we stop the step so that the user has a chance to switch
4815 in assembly mode. */
4816 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
4817 && step_stop_if_no_debug
)
4819 ecs
->event_thread
->control
.stop_step
= 1;
4820 print_end_stepping_range_reason ();
4821 stop_stepping (ecs
);
4825 if (execution_direction
== EXEC_REVERSE
)
4827 /* Set a breakpoint at callee's start address.
4828 From there we can step once and be back in the caller. */
4829 struct symtab_and_line sr_sal
;
4832 sr_sal
.pc
= ecs
->stop_func_start
;
4833 sr_sal
.pspace
= get_frame_program_space (frame
);
4834 insert_step_resume_breakpoint_at_sal (gdbarch
,
4835 sr_sal
, null_frame_id
);
4838 /* Set a breakpoint at callee's return address (the address
4839 at which the caller will resume). */
4840 insert_step_resume_breakpoint_at_caller (frame
);
4846 /* Reverse stepping through solib trampolines. */
4848 if (execution_direction
== EXEC_REVERSE
4849 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
4851 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
4852 || (ecs
->stop_func_start
== 0
4853 && in_solib_dynsym_resolve_code (stop_pc
)))
4855 /* Any solib trampoline code can be handled in reverse
4856 by simply continuing to single-step. We have already
4857 executed the solib function (backwards), and a few
4858 steps will take us back through the trampoline to the
4863 else if (in_solib_dynsym_resolve_code (stop_pc
))
4865 /* Stepped backward into the solib dynsym resolver.
4866 Set a breakpoint at its start and continue, then
4867 one more step will take us out. */
4868 struct symtab_and_line sr_sal
;
4871 sr_sal
.pc
= ecs
->stop_func_start
;
4872 sr_sal
.pspace
= get_frame_program_space (frame
);
4873 insert_step_resume_breakpoint_at_sal (gdbarch
,
4874 sr_sal
, null_frame_id
);
4880 /* If we're in the return path from a shared library trampoline,
4881 we want to proceed through the trampoline when stepping. */
4882 if (gdbarch_in_solib_return_trampoline (gdbarch
,
4883 stop_pc
, ecs
->stop_func_name
))
4885 /* Determine where this trampoline returns. */
4886 CORE_ADDR real_stop_pc
;
4888 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
4891 fprintf_unfiltered (gdb_stdlog
,
4892 "infrun: stepped into solib return tramp\n");
4894 /* Only proceed through if we know where it's going. */
4897 /* And put the step-breakpoint there and go until there. */
4898 struct symtab_and_line sr_sal
;
4900 init_sal (&sr_sal
); /* initialize to zeroes */
4901 sr_sal
.pc
= real_stop_pc
;
4902 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
4903 sr_sal
.pspace
= get_frame_program_space (frame
);
4905 /* Do not specify what the fp should be when we stop since
4906 on some machines the prologue is where the new fp value
4908 insert_step_resume_breakpoint_at_sal (gdbarch
,
4909 sr_sal
, null_frame_id
);
4911 /* Restart without fiddling with the step ranges or
4918 stop_pc_sal
= find_pc_line (stop_pc
, 0);
4920 /* NOTE: tausq/2004-05-24: This if block used to be done before all
4921 the trampoline processing logic, however, there are some trampolines
4922 that have no names, so we should do trampoline handling first. */
4923 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
4924 && ecs
->stop_func_name
== NULL
4925 && stop_pc_sal
.line
== 0)
4928 fprintf_unfiltered (gdb_stdlog
,
4929 "infrun: stepped into undebuggable function\n");
4931 /* The inferior just stepped into, or returned to, an
4932 undebuggable function (where there is no debugging information
4933 and no line number corresponding to the address where the
4934 inferior stopped). Since we want to skip this kind of code,
4935 we keep going until the inferior returns from this
4936 function - unless the user has asked us not to (via
4937 set step-mode) or we no longer know how to get back
4938 to the call site. */
4939 if (step_stop_if_no_debug
4940 || !frame_id_p (frame_unwind_caller_id (frame
)))
4942 /* If we have no line number and the step-stop-if-no-debug
4943 is set, we stop the step so that the user has a chance to
4944 switch in assembly mode. */
4945 ecs
->event_thread
->control
.stop_step
= 1;
4946 print_end_stepping_range_reason ();
4947 stop_stepping (ecs
);
4952 /* Set a breakpoint at callee's return address (the address
4953 at which the caller will resume). */
4954 insert_step_resume_breakpoint_at_caller (frame
);
4960 if (ecs
->event_thread
->control
.step_range_end
== 1)
4962 /* It is stepi or nexti. We always want to stop stepping after
4965 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
4966 ecs
->event_thread
->control
.stop_step
= 1;
4967 print_end_stepping_range_reason ();
4968 stop_stepping (ecs
);
4972 if (stop_pc_sal
.line
== 0)
4974 /* We have no line number information. That means to stop
4975 stepping (does this always happen right after one instruction,
4976 when we do "s" in a function with no line numbers,
4977 or can this happen as a result of a return or longjmp?). */
4979 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
4980 ecs
->event_thread
->control
.stop_step
= 1;
4981 print_end_stepping_range_reason ();
4982 stop_stepping (ecs
);
4986 /* Look for "calls" to inlined functions, part one. If the inline
4987 frame machinery detected some skipped call sites, we have entered
4988 a new inline function. */
4990 if (frame_id_eq (get_frame_id (get_current_frame ()),
4991 ecs
->event_thread
->control
.step_frame_id
)
4992 && inline_skipped_frames (ecs
->ptid
))
4994 struct symtab_and_line call_sal
;
4997 fprintf_unfiltered (gdb_stdlog
,
4998 "infrun: stepped into inlined function\n");
5000 find_frame_sal (get_current_frame (), &call_sal
);
5002 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
5004 /* For "step", we're going to stop. But if the call site
5005 for this inlined function is on the same source line as
5006 we were previously stepping, go down into the function
5007 first. Otherwise stop at the call site. */
5009 if (call_sal
.line
== ecs
->event_thread
->current_line
5010 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
5011 step_into_inline_frame (ecs
->ptid
);
5013 ecs
->event_thread
->control
.stop_step
= 1;
5014 print_end_stepping_range_reason ();
5015 stop_stepping (ecs
);
5020 /* For "next", we should stop at the call site if it is on a
5021 different source line. Otherwise continue through the
5022 inlined function. */
5023 if (call_sal
.line
== ecs
->event_thread
->current_line
5024 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
5028 ecs
->event_thread
->control
.stop_step
= 1;
5029 print_end_stepping_range_reason ();
5030 stop_stepping (ecs
);
5036 /* Look for "calls" to inlined functions, part two. If we are still
5037 in the same real function we were stepping through, but we have
5038 to go further up to find the exact frame ID, we are stepping
5039 through a more inlined call beyond its call site. */
5041 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5042 && !frame_id_eq (get_frame_id (get_current_frame ()),
5043 ecs
->event_thread
->control
.step_frame_id
)
5044 && stepped_in_from (get_current_frame (),
5045 ecs
->event_thread
->control
.step_frame_id
))
5048 fprintf_unfiltered (gdb_stdlog
,
5049 "infrun: stepping through inlined function\n");
5051 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
5055 ecs
->event_thread
->control
.stop_step
= 1;
5056 print_end_stepping_range_reason ();
5057 stop_stepping (ecs
);
5062 if ((stop_pc
== stop_pc_sal
.pc
)
5063 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
5064 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
5066 /* We are at the start of a different line. So stop. Note that
5067 we don't stop if we step into the middle of a different line.
5068 That is said to make things like for (;;) statements work
5071 fprintf_unfiltered (gdb_stdlog
,
5072 "infrun: stepped to a different line\n");
5073 ecs
->event_thread
->control
.stop_step
= 1;
5074 print_end_stepping_range_reason ();
5075 stop_stepping (ecs
);
5079 /* We aren't done stepping.
5081 Optimize by setting the stepping range to the line.
5082 (We might not be in the original line, but if we entered a
5083 new line in mid-statement, we continue stepping. This makes
5084 things like for(;;) statements work better.) */
5086 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
5087 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
5088 set_step_info (frame
, stop_pc_sal
);
5091 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
5095 /* Is thread TP in the middle of single-stepping? */
5098 currently_stepping (struct thread_info
*tp
)
5100 return ((tp
->control
.step_range_end
5101 && tp
->control
.step_resume_breakpoint
== NULL
)
5102 || tp
->control
.trap_expected
5103 || tp
->stepping_through_solib_after_catch
5104 || bpstat_should_step ());
5107 /* Returns true if any thread *but* the one passed in "data" is in the
5108 middle of stepping or of handling a "next". */
5111 currently_stepping_or_nexting_callback (struct thread_info
*tp
, void *data
)
5116 return (tp
->control
.step_range_end
5117 || tp
->control
.trap_expected
5118 || tp
->stepping_through_solib_after_catch
);
5121 /* Inferior has stepped into a subroutine call with source code that
5122 we should not step over. Do step to the first line of code in
5126 handle_step_into_function (struct gdbarch
*gdbarch
,
5127 struct execution_control_state
*ecs
)
5130 struct symtab_and_line stop_func_sal
, sr_sal
;
5132 s
= find_pc_symtab (stop_pc
);
5133 if (s
&& s
->language
!= language_asm
)
5134 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
5135 ecs
->stop_func_start
);
5137 stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
5138 /* Use the step_resume_break to step until the end of the prologue,
5139 even if that involves jumps (as it seems to on the vax under
5141 /* If the prologue ends in the middle of a source line, continue to
5142 the end of that source line (if it is still within the function).
5143 Otherwise, just go to end of prologue. */
5144 if (stop_func_sal
.end
5145 && stop_func_sal
.pc
!= ecs
->stop_func_start
5146 && stop_func_sal
.end
< ecs
->stop_func_end
)
5147 ecs
->stop_func_start
= stop_func_sal
.end
;
5149 /* Architectures which require breakpoint adjustment might not be able
5150 to place a breakpoint at the computed address. If so, the test
5151 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5152 ecs->stop_func_start to an address at which a breakpoint may be
5153 legitimately placed.
5155 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5156 made, GDB will enter an infinite loop when stepping through
5157 optimized code consisting of VLIW instructions which contain
5158 subinstructions corresponding to different source lines. On
5159 FR-V, it's not permitted to place a breakpoint on any but the
5160 first subinstruction of a VLIW instruction. When a breakpoint is
5161 set, GDB will adjust the breakpoint address to the beginning of
5162 the VLIW instruction. Thus, we need to make the corresponding
5163 adjustment here when computing the stop address. */
5165 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
5167 ecs
->stop_func_start
5168 = gdbarch_adjust_breakpoint_address (gdbarch
,
5169 ecs
->stop_func_start
);
5172 if (ecs
->stop_func_start
== stop_pc
)
5174 /* We are already there: stop now. */
5175 ecs
->event_thread
->control
.stop_step
= 1;
5176 print_end_stepping_range_reason ();
5177 stop_stepping (ecs
);
5182 /* Put the step-breakpoint there and go until there. */
5183 init_sal (&sr_sal
); /* initialize to zeroes */
5184 sr_sal
.pc
= ecs
->stop_func_start
;
5185 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
5186 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
5188 /* Do not specify what the fp should be when we stop since on
5189 some machines the prologue is where the new fp value is
5191 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
5193 /* And make sure stepping stops right away then. */
5194 ecs
->event_thread
->control
.step_range_end
5195 = ecs
->event_thread
->control
.step_range_start
;
5200 /* Inferior has stepped backward into a subroutine call with source
5201 code that we should not step over. Do step to the beginning of the
5202 last line of code in it. */
5205 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
5206 struct execution_control_state
*ecs
)
5209 struct symtab_and_line stop_func_sal
;
5211 s
= find_pc_symtab (stop_pc
);
5212 if (s
&& s
->language
!= language_asm
)
5213 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
5214 ecs
->stop_func_start
);
5216 stop_func_sal
= find_pc_line (stop_pc
, 0);
5218 /* OK, we're just going to keep stepping here. */
5219 if (stop_func_sal
.pc
== stop_pc
)
5221 /* We're there already. Just stop stepping now. */
5222 ecs
->event_thread
->control
.stop_step
= 1;
5223 print_end_stepping_range_reason ();
5224 stop_stepping (ecs
);
5228 /* Else just reset the step range and keep going.
5229 No step-resume breakpoint, they don't work for
5230 epilogues, which can have multiple entry paths. */
5231 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
5232 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
5238 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5239 This is used to both functions and to skip over code. */
5242 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
5243 struct symtab_and_line sr_sal
,
5244 struct frame_id sr_id
,
5245 enum bptype sr_type
)
5247 /* There should never be more than one step-resume or longjmp-resume
5248 breakpoint per thread, so we should never be setting a new
5249 step_resume_breakpoint when one is already active. */
5250 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
5251 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
5254 fprintf_unfiltered (gdb_stdlog
,
5255 "infrun: inserting step-resume breakpoint at %s\n",
5256 paddress (gdbarch
, sr_sal
.pc
));
5258 inferior_thread ()->control
.step_resume_breakpoint
5259 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
);
5263 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
5264 struct symtab_and_line sr_sal
,
5265 struct frame_id sr_id
)
5267 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
5272 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5273 This is used to skip a potential signal handler.
5275 This is called with the interrupted function's frame. The signal
5276 handler, when it returns, will resume the interrupted function at
5280 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
5282 struct symtab_and_line sr_sal
;
5283 struct gdbarch
*gdbarch
;
5285 gdb_assert (return_frame
!= NULL
);
5286 init_sal (&sr_sal
); /* initialize to zeros */
5288 gdbarch
= get_frame_arch (return_frame
);
5289 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
5290 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
5291 sr_sal
.pspace
= get_frame_program_space (return_frame
);
5293 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
5294 get_stack_frame_id (return_frame
),
5298 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5299 is used to skip a function after stepping into it (for "next" or if
5300 the called function has no debugging information).
5302 The current function has almost always been reached by single
5303 stepping a call or return instruction. NEXT_FRAME belongs to the
5304 current function, and the breakpoint will be set at the caller's
5307 This is a separate function rather than reusing
5308 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5309 get_prev_frame, which may stop prematurely (see the implementation
5310 of frame_unwind_caller_id for an example). */
5313 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
5315 struct symtab_and_line sr_sal
;
5316 struct gdbarch
*gdbarch
;
5318 /* We shouldn't have gotten here if we don't know where the call site
5320 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
5322 init_sal (&sr_sal
); /* initialize to zeros */
5324 gdbarch
= frame_unwind_caller_arch (next_frame
);
5325 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
5326 frame_unwind_caller_pc (next_frame
));
5327 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
5328 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
5330 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
5331 frame_unwind_caller_id (next_frame
));
5334 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5335 new breakpoint at the target of a jmp_buf. The handling of
5336 longjmp-resume uses the same mechanisms used for handling
5337 "step-resume" breakpoints. */
5340 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
5342 /* There should never be more than one step-resume or longjmp-resume
5343 breakpoint per thread, so we should never be setting a new
5344 longjmp_resume_breakpoint when one is already active. */
5345 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
5348 fprintf_unfiltered (gdb_stdlog
,
5349 "infrun: inserting longjmp-resume breakpoint at %s\n",
5350 paddress (gdbarch
, pc
));
5352 inferior_thread ()->control
.step_resume_breakpoint
=
5353 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
);
5356 /* Insert an exception resume breakpoint. TP is the thread throwing
5357 the exception. The block B is the block of the unwinder debug hook
5358 function. FRAME is the frame corresponding to the call to this
5359 function. SYM is the symbol of the function argument holding the
5360 target PC of the exception. */
5363 insert_exception_resume_breakpoint (struct thread_info
*tp
,
5365 struct frame_info
*frame
,
5368 struct gdb_exception e
;
5370 /* We want to ignore errors here. */
5371 TRY_CATCH (e
, RETURN_MASK_ERROR
)
5373 struct symbol
*vsym
;
5374 struct value
*value
;
5376 struct breakpoint
*bp
;
5378 vsym
= lookup_symbol (SYMBOL_LINKAGE_NAME (sym
), b
, VAR_DOMAIN
, NULL
);
5379 value
= read_var_value (vsym
, frame
);
5380 /* If the value was optimized out, revert to the old behavior. */
5381 if (! value_optimized_out (value
))
5383 handler
= value_as_address (value
);
5386 fprintf_unfiltered (gdb_stdlog
,
5387 "infrun: exception resume at %lx\n",
5388 (unsigned long) handler
);
5390 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
5391 handler
, bp_exception_resume
);
5392 bp
->thread
= tp
->num
;
5393 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
5398 /* This is called when an exception has been intercepted. Check to
5399 see whether the exception's destination is of interest, and if so,
5400 set an exception resume breakpoint there. */
5403 check_exception_resume (struct execution_control_state
*ecs
,
5404 struct frame_info
*frame
, struct symbol
*func
)
5406 struct gdb_exception e
;
5408 TRY_CATCH (e
, RETURN_MASK_ERROR
)
5411 struct dict_iterator iter
;
5415 /* The exception breakpoint is a thread-specific breakpoint on
5416 the unwinder's debug hook, declared as:
5418 void _Unwind_DebugHook (void *cfa, void *handler);
5420 The CFA argument indicates the frame to which control is
5421 about to be transferred. HANDLER is the destination PC.
5423 We ignore the CFA and set a temporary breakpoint at HANDLER.
5424 This is not extremely efficient but it avoids issues in gdb
5425 with computing the DWARF CFA, and it also works even in weird
5426 cases such as throwing an exception from inside a signal
5429 b
= SYMBOL_BLOCK_VALUE (func
);
5430 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
5432 if (!SYMBOL_IS_ARGUMENT (sym
))
5439 insert_exception_resume_breakpoint (ecs
->event_thread
,
5448 stop_stepping (struct execution_control_state
*ecs
)
5451 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_stepping\n");
5453 /* Let callers know we don't want to wait for the inferior anymore. */
5454 ecs
->wait_some_more
= 0;
5457 /* This function handles various cases where we need to continue
5458 waiting for the inferior. */
5459 /* (Used to be the keep_going: label in the old wait_for_inferior). */
5462 keep_going (struct execution_control_state
*ecs
)
5464 /* Make sure normal_stop is called if we get a QUIT handled before
5466 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
5468 /* Save the pc before execution, to compare with pc after stop. */
5469 ecs
->event_thread
->prev_pc
5470 = regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5472 /* If we did not do break;, it means we should keep running the
5473 inferior and not return to debugger. */
5475 if (ecs
->event_thread
->control
.trap_expected
5476 && ecs
->event_thread
->suspend
.stop_signal
!= TARGET_SIGNAL_TRAP
)
5478 /* We took a signal (which we are supposed to pass through to
5479 the inferior, else we'd not get here) and we haven't yet
5480 gotten our trap. Simply continue. */
5482 discard_cleanups (old_cleanups
);
5483 resume (currently_stepping (ecs
->event_thread
),
5484 ecs
->event_thread
->suspend
.stop_signal
);
5488 /* Either the trap was not expected, but we are continuing
5489 anyway (the user asked that this signal be passed to the
5492 The signal was SIGTRAP, e.g. it was our signal, but we
5493 decided we should resume from it.
5495 We're going to run this baby now!
5497 Note that insert_breakpoints won't try to re-insert
5498 already inserted breakpoints. Therefore, we don't
5499 care if breakpoints were already inserted, or not. */
5501 if (ecs
->event_thread
->stepping_over_breakpoint
)
5503 struct regcache
*thread_regcache
= get_thread_regcache (ecs
->ptid
);
5505 if (!use_displaced_stepping (get_regcache_arch (thread_regcache
)))
5506 /* Since we can't do a displaced step, we have to remove
5507 the breakpoint while we step it. To keep things
5508 simple, we remove them all. */
5509 remove_breakpoints ();
5513 struct gdb_exception e
;
5515 /* Stop stepping when inserting breakpoints
5517 TRY_CATCH (e
, RETURN_MASK_ERROR
)
5519 insert_breakpoints ();
5523 exception_print (gdb_stderr
, e
);
5524 stop_stepping (ecs
);
5529 ecs
->event_thread
->control
.trap_expected
5530 = ecs
->event_thread
->stepping_over_breakpoint
;
5532 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5533 specifies that such a signal should be delivered to the
5536 Typically, this would occure when a user is debugging a
5537 target monitor on a simulator: the target monitor sets a
5538 breakpoint; the simulator encounters this break-point and
5539 halts the simulation handing control to GDB; GDB, noteing
5540 that the break-point isn't valid, returns control back to the
5541 simulator; the simulator then delivers the hardware
5542 equivalent of a SIGNAL_TRAP to the program being debugged. */
5544 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
5545 && !signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
5546 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
5548 discard_cleanups (old_cleanups
);
5549 resume (currently_stepping (ecs
->event_thread
),
5550 ecs
->event_thread
->suspend
.stop_signal
);
5553 prepare_to_wait (ecs
);
5556 /* This function normally comes after a resume, before
5557 handle_inferior_event exits. It takes care of any last bits of
5558 housekeeping, and sets the all-important wait_some_more flag. */
5561 prepare_to_wait (struct execution_control_state
*ecs
)
5564 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
5566 /* This is the old end of the while loop. Let everybody know we
5567 want to wait for the inferior some more and get called again
5569 ecs
->wait_some_more
= 1;
5572 /* Several print_*_reason functions to print why the inferior has stopped.
5573 We always print something when the inferior exits, or receives a signal.
5574 The rest of the cases are dealt with later on in normal_stop and
5575 print_it_typical. Ideally there should be a call to one of these
5576 print_*_reason functions functions from handle_inferior_event each time
5577 stop_stepping is called. */
5579 /* Print why the inferior has stopped.
5580 We are done with a step/next/si/ni command, print why the inferior has
5581 stopped. For now print nothing. Print a message only if not in the middle
5582 of doing a "step n" operation for n > 1. */
5585 print_end_stepping_range_reason (void)
5587 if ((!inferior_thread ()->step_multi
5588 || !inferior_thread ()->control
.stop_step
)
5589 && ui_out_is_mi_like_p (uiout
))
5590 ui_out_field_string (uiout
, "reason",
5591 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
5594 /* The inferior was terminated by a signal, print why it stopped. */
5597 print_signal_exited_reason (enum target_signal siggnal
)
5599 annotate_signalled ();
5600 if (ui_out_is_mi_like_p (uiout
))
5602 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
5603 ui_out_text (uiout
, "\nProgram terminated with signal ");
5604 annotate_signal_name ();
5605 ui_out_field_string (uiout
, "signal-name",
5606 target_signal_to_name (siggnal
));
5607 annotate_signal_name_end ();
5608 ui_out_text (uiout
, ", ");
5609 annotate_signal_string ();
5610 ui_out_field_string (uiout
, "signal-meaning",
5611 target_signal_to_string (siggnal
));
5612 annotate_signal_string_end ();
5613 ui_out_text (uiout
, ".\n");
5614 ui_out_text (uiout
, "The program no longer exists.\n");
5617 /* The inferior program is finished, print why it stopped. */
5620 print_exited_reason (int exitstatus
)
5622 struct inferior
*inf
= current_inferior ();
5623 const char *pidstr
= target_pid_to_str (pid_to_ptid (inf
->pid
));
5625 annotate_exited (exitstatus
);
5628 if (ui_out_is_mi_like_p (uiout
))
5629 ui_out_field_string (uiout
, "reason",
5630 async_reason_lookup (EXEC_ASYNC_EXITED
));
5631 ui_out_text (uiout
, "[Inferior ");
5632 ui_out_text (uiout
, plongest (inf
->num
));
5633 ui_out_text (uiout
, " (");
5634 ui_out_text (uiout
, pidstr
);
5635 ui_out_text (uiout
, ") exited with code ");
5636 ui_out_field_fmt (uiout
, "exit-code", "0%o", (unsigned int) exitstatus
);
5637 ui_out_text (uiout
, "]\n");
5641 if (ui_out_is_mi_like_p (uiout
))
5643 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
5644 ui_out_text (uiout
, "[Inferior ");
5645 ui_out_text (uiout
, plongest (inf
->num
));
5646 ui_out_text (uiout
, " (");
5647 ui_out_text (uiout
, pidstr
);
5648 ui_out_text (uiout
, ") exited normally]\n");
5650 /* Support the --return-child-result option. */
5651 return_child_result_value
= exitstatus
;
5654 /* Signal received, print why the inferior has stopped. The signal table
5655 tells us to print about it. */
5658 print_signal_received_reason (enum target_signal siggnal
)
5662 if (siggnal
== TARGET_SIGNAL_0
&& !ui_out_is_mi_like_p (uiout
))
5664 struct thread_info
*t
= inferior_thread ();
5666 ui_out_text (uiout
, "\n[");
5667 ui_out_field_string (uiout
, "thread-name",
5668 target_pid_to_str (t
->ptid
));
5669 ui_out_field_fmt (uiout
, "thread-id", "] #%d", t
->num
);
5670 ui_out_text (uiout
, " stopped");
5674 ui_out_text (uiout
, "\nProgram received signal ");
5675 annotate_signal_name ();
5676 if (ui_out_is_mi_like_p (uiout
))
5678 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
5679 ui_out_field_string (uiout
, "signal-name",
5680 target_signal_to_name (siggnal
));
5681 annotate_signal_name_end ();
5682 ui_out_text (uiout
, ", ");
5683 annotate_signal_string ();
5684 ui_out_field_string (uiout
, "signal-meaning",
5685 target_signal_to_string (siggnal
));
5686 annotate_signal_string_end ();
5688 ui_out_text (uiout
, ".\n");
5691 /* Reverse execution: target ran out of history info, print why the inferior
5695 print_no_history_reason (void)
5697 ui_out_text (uiout
, "\nNo more reverse-execution history.\n");
5700 /* Here to return control to GDB when the inferior stops for real.
5701 Print appropriate messages, remove breakpoints, give terminal our modes.
5703 STOP_PRINT_FRAME nonzero means print the executing frame
5704 (pc, function, args, file, line number and line text).
5705 BREAKPOINTS_FAILED nonzero means stop was due to error
5706 attempting to insert breakpoints. */
5711 struct target_waitstatus last
;
5713 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
5715 get_last_target_status (&last_ptid
, &last
);
5717 /* If an exception is thrown from this point on, make sure to
5718 propagate GDB's knowledge of the executing state to the
5719 frontend/user running state. A QUIT is an easy exception to see
5720 here, so do this before any filtered output. */
5722 make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
5723 else if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
5724 && last
.kind
!= TARGET_WAITKIND_EXITED
)
5725 make_cleanup (finish_thread_state_cleanup
, &inferior_ptid
);
5727 /* In non-stop mode, we don't want GDB to switch threads behind the
5728 user's back, to avoid races where the user is typing a command to
5729 apply to thread x, but GDB switches to thread y before the user
5730 finishes entering the command. */
5732 /* As with the notification of thread events, we want to delay
5733 notifying the user that we've switched thread context until
5734 the inferior actually stops.
5736 There's no point in saying anything if the inferior has exited.
5737 Note that SIGNALLED here means "exited with a signal", not
5738 "received a signal". */
5740 && !ptid_equal (previous_inferior_ptid
, inferior_ptid
)
5741 && target_has_execution
5742 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
5743 && last
.kind
!= TARGET_WAITKIND_EXITED
)
5745 target_terminal_ours_for_output ();
5746 printf_filtered (_("[Switching to %s]\n"),
5747 target_pid_to_str (inferior_ptid
));
5748 annotate_thread_changed ();
5749 previous_inferior_ptid
= inferior_ptid
;
5752 if (!breakpoints_always_inserted_mode () && target_has_execution
)
5754 if (remove_breakpoints ())
5756 target_terminal_ours_for_output ();
5757 printf_filtered (_("Cannot remove breakpoints because "
5758 "program is no longer writable.\nFurther "
5759 "execution is probably impossible.\n"));
5763 /* If an auto-display called a function and that got a signal,
5764 delete that auto-display to avoid an infinite recursion. */
5766 if (stopped_by_random_signal
)
5767 disable_current_display ();
5769 /* Don't print a message if in the middle of doing a "step n"
5770 operation for n > 1 */
5771 if (target_has_execution
5772 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
5773 && last
.kind
!= TARGET_WAITKIND_EXITED
5774 && inferior_thread ()->step_multi
5775 && inferior_thread ()->control
.stop_step
)
5778 target_terminal_ours ();
5780 /* Set the current source location. This will also happen if we
5781 display the frame below, but the current SAL will be incorrect
5782 during a user hook-stop function. */
5783 if (has_stack_frames () && !stop_stack_dummy
)
5784 set_current_sal_from_frame (get_current_frame (), 1);
5786 /* Let the user/frontend see the threads as stopped. */
5787 do_cleanups (old_chain
);
5789 /* Look up the hook_stop and run it (CLI internally handles problem
5790 of stop_command's pre-hook not existing). */
5792 catch_errors (hook_stop_stub
, stop_command
,
5793 "Error while running hook_stop:\n", RETURN_MASK_ALL
);
5795 if (!has_stack_frames ())
5798 if (last
.kind
== TARGET_WAITKIND_SIGNALLED
5799 || last
.kind
== TARGET_WAITKIND_EXITED
)
5802 /* Select innermost stack frame - i.e., current frame is frame 0,
5803 and current location is based on that.
5804 Don't do this on return from a stack dummy routine,
5805 or if the program has exited. */
5807 if (!stop_stack_dummy
)
5809 select_frame (get_current_frame ());
5811 /* Print current location without a level number, if
5812 we have changed functions or hit a breakpoint.
5813 Print source line if we have one.
5814 bpstat_print() contains the logic deciding in detail
5815 what to print, based on the event(s) that just occurred. */
5817 /* If --batch-silent is enabled then there's no need to print the current
5818 source location, and to try risks causing an error message about
5819 missing source files. */
5820 if (stop_print_frame
&& !batch_silent
)
5824 int do_frame_printing
= 1;
5825 struct thread_info
*tp
= inferior_thread ();
5827 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
);
5831 /* If we had hit a shared library event breakpoint,
5832 bpstat_print would print out this message. If we hit
5833 an OS-level shared library event, do the same
5835 if (last
.kind
== TARGET_WAITKIND_LOADED
)
5837 printf_filtered (_("Stopped due to shared library event\n"));
5838 source_flag
= SRC_LINE
; /* something bogus */
5839 do_frame_printing
= 0;
5843 /* FIXME: cagney/2002-12-01: Given that a frame ID does
5844 (or should) carry around the function and does (or
5845 should) use that when doing a frame comparison. */
5846 if (tp
->control
.stop_step
5847 && frame_id_eq (tp
->control
.step_frame_id
,
5848 get_frame_id (get_current_frame ()))
5849 && step_start_function
== find_pc_function (stop_pc
))
5850 source_flag
= SRC_LINE
; /* Finished step, just
5851 print source line. */
5853 source_flag
= SRC_AND_LOC
; /* Print location and
5856 case PRINT_SRC_AND_LOC
:
5857 source_flag
= SRC_AND_LOC
; /* Print location and
5860 case PRINT_SRC_ONLY
:
5861 source_flag
= SRC_LINE
;
5864 source_flag
= SRC_LINE
; /* something bogus */
5865 do_frame_printing
= 0;
5868 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
5871 /* The behavior of this routine with respect to the source
5873 SRC_LINE: Print only source line
5874 LOCATION: Print only location
5875 SRC_AND_LOC: Print location and source line. */
5876 if (do_frame_printing
)
5877 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
);
5879 /* Display the auto-display expressions. */
5884 /* Save the function value return registers, if we care.
5885 We might be about to restore their previous contents. */
5886 if (inferior_thread ()->control
.proceed_to_finish
5887 && execution_direction
!= EXEC_REVERSE
)
5889 /* This should not be necessary. */
5891 regcache_xfree (stop_registers
);
5893 /* NB: The copy goes through to the target picking up the value of
5894 all the registers. */
5895 stop_registers
= regcache_dup (get_current_regcache ());
5898 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
5900 /* Pop the empty frame that contains the stack dummy.
5901 This also restores inferior state prior to the call
5902 (struct infcall_suspend_state). */
5903 struct frame_info
*frame
= get_current_frame ();
5905 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
5907 /* frame_pop() calls reinit_frame_cache as the last thing it
5908 does which means there's currently no selected frame. We
5909 don't need to re-establish a selected frame if the dummy call
5910 returns normally, that will be done by
5911 restore_infcall_control_state. However, we do have to handle
5912 the case where the dummy call is returning after being
5913 stopped (e.g. the dummy call previously hit a breakpoint).
5914 We can't know which case we have so just always re-establish
5915 a selected frame here. */
5916 select_frame (get_current_frame ());
5920 annotate_stopped ();
5922 /* Suppress the stop observer if we're in the middle of:
5924 - a step n (n > 1), as there still more steps to be done.
5926 - a "finish" command, as the observer will be called in
5927 finish_command_continuation, so it can include the inferior
5928 function's return value.
5930 - calling an inferior function, as we pretend we inferior didn't
5931 run at all. The return value of the call is handled by the
5932 expression evaluator, through call_function_by_hand. */
5934 if (!target_has_execution
5935 || last
.kind
== TARGET_WAITKIND_SIGNALLED
5936 || last
.kind
== TARGET_WAITKIND_EXITED
5937 || (!inferior_thread ()->step_multi
5938 && !(inferior_thread ()->control
.stop_bpstat
5939 && inferior_thread ()->control
.proceed_to_finish
)
5940 && !inferior_thread ()->control
.in_infcall
))
5942 if (!ptid_equal (inferior_ptid
, null_ptid
))
5943 observer_notify_normal_stop (inferior_thread ()->control
.stop_bpstat
,
5946 observer_notify_normal_stop (NULL
, stop_print_frame
);
5949 if (target_has_execution
)
5951 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
5952 && last
.kind
!= TARGET_WAITKIND_EXITED
)
5953 /* Delete the breakpoint we stopped at, if it wants to be deleted.
5954 Delete any breakpoint that is to be deleted at the next stop. */
5955 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
5958 /* Try to get rid of automatically added inferiors that are no
5959 longer needed. Keeping those around slows down things linearly.
5960 Note that this never removes the current inferior. */
5965 hook_stop_stub (void *cmd
)
5967 execute_cmd_pre_hook ((struct cmd_list_element
*) cmd
);
5972 signal_stop_state (int signo
)
5974 return signal_stop
[signo
];
5978 signal_print_state (int signo
)
5980 return signal_print
[signo
];
5984 signal_pass_state (int signo
)
5986 return signal_program
[signo
];
5990 signal_cache_update (int signo
)
5994 for (signo
= 0; signo
< (int) TARGET_SIGNAL_LAST
; signo
++)
5995 signal_cache_update (signo
);
6000 signal_pass
[signo
] = (signal_stop
[signo
] == 0
6001 && signal_print
[signo
] == 0
6002 && signal_program
[signo
] == 1);
6006 signal_stop_update (int signo
, int state
)
6008 int ret
= signal_stop
[signo
];
6010 signal_stop
[signo
] = state
;
6011 signal_cache_update (signo
);
6016 signal_print_update (int signo
, int state
)
6018 int ret
= signal_print
[signo
];
6020 signal_print
[signo
] = state
;
6021 signal_cache_update (signo
);
6026 signal_pass_update (int signo
, int state
)
6028 int ret
= signal_program
[signo
];
6030 signal_program
[signo
] = state
;
6031 signal_cache_update (signo
);
6036 sig_print_header (void)
6038 printf_filtered (_("Signal Stop\tPrint\tPass "
6039 "to program\tDescription\n"));
6043 sig_print_info (enum target_signal oursig
)
6045 const char *name
= target_signal_to_name (oursig
);
6046 int name_padding
= 13 - strlen (name
);
6048 if (name_padding
<= 0)
6051 printf_filtered ("%s", name
);
6052 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
6053 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
6054 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
6055 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
6056 printf_filtered ("%s\n", target_signal_to_string (oursig
));
6059 /* Specify how various signals in the inferior should be handled. */
6062 handle_command (char *args
, int from_tty
)
6065 int digits
, wordlen
;
6066 int sigfirst
, signum
, siglast
;
6067 enum target_signal oursig
;
6070 unsigned char *sigs
;
6071 struct cleanup
*old_chain
;
6075 error_no_arg (_("signal to handle"));
6078 /* Allocate and zero an array of flags for which signals to handle. */
6080 nsigs
= (int) TARGET_SIGNAL_LAST
;
6081 sigs
= (unsigned char *) alloca (nsigs
);
6082 memset (sigs
, 0, nsigs
);
6084 /* Break the command line up into args. */
6086 argv
= gdb_buildargv (args
);
6087 old_chain
= make_cleanup_freeargv (argv
);
6089 /* Walk through the args, looking for signal oursigs, signal names, and
6090 actions. Signal numbers and signal names may be interspersed with
6091 actions, with the actions being performed for all signals cumulatively
6092 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6094 while (*argv
!= NULL
)
6096 wordlen
= strlen (*argv
);
6097 for (digits
= 0; isdigit ((*argv
)[digits
]); digits
++)
6101 sigfirst
= siglast
= -1;
6103 if (wordlen
>= 1 && !strncmp (*argv
, "all", wordlen
))
6105 /* Apply action to all signals except those used by the
6106 debugger. Silently skip those. */
6109 siglast
= nsigs
- 1;
6111 else if (wordlen
>= 1 && !strncmp (*argv
, "stop", wordlen
))
6113 SET_SIGS (nsigs
, sigs
, signal_stop
);
6114 SET_SIGS (nsigs
, sigs
, signal_print
);
6116 else if (wordlen
>= 1 && !strncmp (*argv
, "ignore", wordlen
))
6118 UNSET_SIGS (nsigs
, sigs
, signal_program
);
6120 else if (wordlen
>= 2 && !strncmp (*argv
, "print", wordlen
))
6122 SET_SIGS (nsigs
, sigs
, signal_print
);
6124 else if (wordlen
>= 2 && !strncmp (*argv
, "pass", wordlen
))
6126 SET_SIGS (nsigs
, sigs
, signal_program
);
6128 else if (wordlen
>= 3 && !strncmp (*argv
, "nostop", wordlen
))
6130 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
6132 else if (wordlen
>= 3 && !strncmp (*argv
, "noignore", wordlen
))
6134 SET_SIGS (nsigs
, sigs
, signal_program
);
6136 else if (wordlen
>= 4 && !strncmp (*argv
, "noprint", wordlen
))
6138 UNSET_SIGS (nsigs
, sigs
, signal_print
);
6139 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
6141 else if (wordlen
>= 4 && !strncmp (*argv
, "nopass", wordlen
))
6143 UNSET_SIGS (nsigs
, sigs
, signal_program
);
6145 else if (digits
> 0)
6147 /* It is numeric. The numeric signal refers to our own
6148 internal signal numbering from target.h, not to host/target
6149 signal number. This is a feature; users really should be
6150 using symbolic names anyway, and the common ones like
6151 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6153 sigfirst
= siglast
= (int)
6154 target_signal_from_command (atoi (*argv
));
6155 if ((*argv
)[digits
] == '-')
6158 target_signal_from_command (atoi ((*argv
) + digits
+ 1));
6160 if (sigfirst
> siglast
)
6162 /* Bet he didn't figure we'd think of this case... */
6170 oursig
= target_signal_from_name (*argv
);
6171 if (oursig
!= TARGET_SIGNAL_UNKNOWN
)
6173 sigfirst
= siglast
= (int) oursig
;
6177 /* Not a number and not a recognized flag word => complain. */
6178 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv
);
6182 /* If any signal numbers or symbol names were found, set flags for
6183 which signals to apply actions to. */
6185 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
6187 switch ((enum target_signal
) signum
)
6189 case TARGET_SIGNAL_TRAP
:
6190 case TARGET_SIGNAL_INT
:
6191 if (!allsigs
&& !sigs
[signum
])
6193 if (query (_("%s is used by the debugger.\n\
6194 Are you sure you want to change it? "),
6195 target_signal_to_name ((enum target_signal
) signum
)))
6201 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6202 gdb_flush (gdb_stdout
);
6206 case TARGET_SIGNAL_0
:
6207 case TARGET_SIGNAL_DEFAULT
:
6208 case TARGET_SIGNAL_UNKNOWN
:
6209 /* Make sure that "all" doesn't print these. */
6220 for (signum
= 0; signum
< nsigs
; signum
++)
6223 signal_cache_update (-1);
6224 target_pass_signals ((int) TARGET_SIGNAL_LAST
, signal_pass
);
6228 /* Show the results. */
6229 sig_print_header ();
6230 for (; signum
< nsigs
; signum
++)
6232 sig_print_info (signum
);
6238 do_cleanups (old_chain
);
6242 xdb_handle_command (char *args
, int from_tty
)
6245 struct cleanup
*old_chain
;
6248 error_no_arg (_("xdb command"));
6250 /* Break the command line up into args. */
6252 argv
= gdb_buildargv (args
);
6253 old_chain
= make_cleanup_freeargv (argv
);
6254 if (argv
[1] != (char *) NULL
)
6259 bufLen
= strlen (argv
[0]) + 20;
6260 argBuf
= (char *) xmalloc (bufLen
);
6264 enum target_signal oursig
;
6266 oursig
= target_signal_from_name (argv
[0]);
6267 memset (argBuf
, 0, bufLen
);
6268 if (strcmp (argv
[1], "Q") == 0)
6269 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
6272 if (strcmp (argv
[1], "s") == 0)
6274 if (!signal_stop
[oursig
])
6275 sprintf (argBuf
, "%s %s", argv
[0], "stop");
6277 sprintf (argBuf
, "%s %s", argv
[0], "nostop");
6279 else if (strcmp (argv
[1], "i") == 0)
6281 if (!signal_program
[oursig
])
6282 sprintf (argBuf
, "%s %s", argv
[0], "pass");
6284 sprintf (argBuf
, "%s %s", argv
[0], "nopass");
6286 else if (strcmp (argv
[1], "r") == 0)
6288 if (!signal_print
[oursig
])
6289 sprintf (argBuf
, "%s %s", argv
[0], "print");
6291 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
6297 handle_command (argBuf
, from_tty
);
6299 printf_filtered (_("Invalid signal handling flag.\n"));
6304 do_cleanups (old_chain
);
6307 /* Print current contents of the tables set by the handle command.
6308 It is possible we should just be printing signals actually used
6309 by the current target (but for things to work right when switching
6310 targets, all signals should be in the signal tables). */
6313 signals_info (char *signum_exp
, int from_tty
)
6315 enum target_signal oursig
;
6317 sig_print_header ();
6321 /* First see if this is a symbol name. */
6322 oursig
= target_signal_from_name (signum_exp
);
6323 if (oursig
== TARGET_SIGNAL_UNKNOWN
)
6325 /* No, try numeric. */
6327 target_signal_from_command (parse_and_eval_long (signum_exp
));
6329 sig_print_info (oursig
);
6333 printf_filtered ("\n");
6334 /* These ugly casts brought to you by the native VAX compiler. */
6335 for (oursig
= TARGET_SIGNAL_FIRST
;
6336 (int) oursig
< (int) TARGET_SIGNAL_LAST
;
6337 oursig
= (enum target_signal
) ((int) oursig
+ 1))
6341 if (oursig
!= TARGET_SIGNAL_UNKNOWN
6342 && oursig
!= TARGET_SIGNAL_DEFAULT
&& oursig
!= TARGET_SIGNAL_0
)
6343 sig_print_info (oursig
);
6346 printf_filtered (_("\nUse the \"handle\" command "
6347 "to change these tables.\n"));
6350 /* The $_siginfo convenience variable is a bit special. We don't know
6351 for sure the type of the value until we actually have a chance to
6352 fetch the data. The type can change depending on gdbarch, so it is
6353 also dependent on which thread you have selected.
6355 1. making $_siginfo be an internalvar that creates a new value on
6358 2. making the value of $_siginfo be an lval_computed value. */
6360 /* This function implements the lval_computed support for reading a
6364 siginfo_value_read (struct value
*v
)
6366 LONGEST transferred
;
6369 target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
,
6371 value_contents_all_raw (v
),
6373 TYPE_LENGTH (value_type (v
)));
6375 if (transferred
!= TYPE_LENGTH (value_type (v
)))
6376 error (_("Unable to read siginfo"));
6379 /* This function implements the lval_computed support for writing a
6383 siginfo_value_write (struct value
*v
, struct value
*fromval
)
6385 LONGEST transferred
;
6387 transferred
= target_write (¤t_target
,
6388 TARGET_OBJECT_SIGNAL_INFO
,
6390 value_contents_all_raw (fromval
),
6392 TYPE_LENGTH (value_type (fromval
)));
6394 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
6395 error (_("Unable to write siginfo"));
6398 static struct lval_funcs siginfo_value_funcs
=
6404 /* Return a new value with the correct type for the siginfo object of
6405 the current thread using architecture GDBARCH. Return a void value
6406 if there's no object available. */
6408 static struct value
*
6409 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
)
6411 if (target_has_stack
6412 && !ptid_equal (inferior_ptid
, null_ptid
)
6413 && gdbarch_get_siginfo_type_p (gdbarch
))
6415 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
6417 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
6420 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
6424 /* infcall_suspend_state contains state about the program itself like its
6425 registers and any signal it received when it last stopped.
6426 This state must be restored regardless of how the inferior function call
6427 ends (either successfully, or after it hits a breakpoint or signal)
6428 if the program is to properly continue where it left off. */
6430 struct infcall_suspend_state
6432 struct thread_suspend_state thread_suspend
;
6433 struct inferior_suspend_state inferior_suspend
;
6437 struct regcache
*registers
;
6439 /* Format of SIGINFO_DATA or NULL if it is not present. */
6440 struct gdbarch
*siginfo_gdbarch
;
6442 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6443 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6444 content would be invalid. */
6445 gdb_byte
*siginfo_data
;
6448 struct infcall_suspend_state
*
6449 save_infcall_suspend_state (void)
6451 struct infcall_suspend_state
*inf_state
;
6452 struct thread_info
*tp
= inferior_thread ();
6453 struct inferior
*inf
= current_inferior ();
6454 struct regcache
*regcache
= get_current_regcache ();
6455 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
6456 gdb_byte
*siginfo_data
= NULL
;
6458 if (gdbarch_get_siginfo_type_p (gdbarch
))
6460 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
6461 size_t len
= TYPE_LENGTH (type
);
6462 struct cleanup
*back_to
;
6464 siginfo_data
= xmalloc (len
);
6465 back_to
= make_cleanup (xfree
, siginfo_data
);
6467 if (target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
6468 siginfo_data
, 0, len
) == len
)
6469 discard_cleanups (back_to
);
6472 /* Errors ignored. */
6473 do_cleanups (back_to
);
6474 siginfo_data
= NULL
;
6478 inf_state
= XZALLOC (struct infcall_suspend_state
);
6482 inf_state
->siginfo_gdbarch
= gdbarch
;
6483 inf_state
->siginfo_data
= siginfo_data
;
6486 inf_state
->thread_suspend
= tp
->suspend
;
6487 inf_state
->inferior_suspend
= inf
->suspend
;
6489 /* run_inferior_call will not use the signal due to its `proceed' call with
6490 TARGET_SIGNAL_0 anyway. */
6491 tp
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
6493 inf_state
->stop_pc
= stop_pc
;
6495 inf_state
->registers
= regcache_dup (regcache
);
6500 /* Restore inferior session state to INF_STATE. */
6503 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
6505 struct thread_info
*tp
= inferior_thread ();
6506 struct inferior
*inf
= current_inferior ();
6507 struct regcache
*regcache
= get_current_regcache ();
6508 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
6510 tp
->suspend
= inf_state
->thread_suspend
;
6511 inf
->suspend
= inf_state
->inferior_suspend
;
6513 stop_pc
= inf_state
->stop_pc
;
6515 if (inf_state
->siginfo_gdbarch
== gdbarch
)
6517 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
6518 size_t len
= TYPE_LENGTH (type
);
6520 /* Errors ignored. */
6521 target_write (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
6522 inf_state
->siginfo_data
, 0, len
);
6525 /* The inferior can be gone if the user types "print exit(0)"
6526 (and perhaps other times). */
6527 if (target_has_execution
)
6528 /* NB: The register write goes through to the target. */
6529 regcache_cpy (regcache
, inf_state
->registers
);
6531 discard_infcall_suspend_state (inf_state
);
6535 do_restore_infcall_suspend_state_cleanup (void *state
)
6537 restore_infcall_suspend_state (state
);
6541 make_cleanup_restore_infcall_suspend_state
6542 (struct infcall_suspend_state
*inf_state
)
6544 return make_cleanup (do_restore_infcall_suspend_state_cleanup
, inf_state
);
6548 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
6550 regcache_xfree (inf_state
->registers
);
6551 xfree (inf_state
->siginfo_data
);
6556 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
6558 return inf_state
->registers
;
6561 /* infcall_control_state contains state regarding gdb's control of the
6562 inferior itself like stepping control. It also contains session state like
6563 the user's currently selected frame. */
6565 struct infcall_control_state
6567 struct thread_control_state thread_control
;
6568 struct inferior_control_state inferior_control
;
6571 enum stop_stack_kind stop_stack_dummy
;
6572 int stopped_by_random_signal
;
6573 int stop_after_trap
;
6575 /* ID if the selected frame when the inferior function call was made. */
6576 struct frame_id selected_frame_id
;
6579 /* Save all of the information associated with the inferior<==>gdb
6582 struct infcall_control_state
*
6583 save_infcall_control_state (void)
6585 struct infcall_control_state
*inf_status
= xmalloc (sizeof (*inf_status
));
6586 struct thread_info
*tp
= inferior_thread ();
6587 struct inferior
*inf
= current_inferior ();
6589 inf_status
->thread_control
= tp
->control
;
6590 inf_status
->inferior_control
= inf
->control
;
6592 tp
->control
.step_resume_breakpoint
= NULL
;
6593 tp
->control
.exception_resume_breakpoint
= NULL
;
6595 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6596 chain. If caller's caller is walking the chain, they'll be happier if we
6597 hand them back the original chain when restore_infcall_control_state is
6599 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
6602 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
6603 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
6604 inf_status
->stop_after_trap
= stop_after_trap
;
6606 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
6612 restore_selected_frame (void *args
)
6614 struct frame_id
*fid
= (struct frame_id
*) args
;
6615 struct frame_info
*frame
;
6617 frame
= frame_find_by_id (*fid
);
6619 /* If inf_status->selected_frame_id is NULL, there was no previously
6623 warning (_("Unable to restore previously selected frame."));
6627 select_frame (frame
);
6632 /* Restore inferior session state to INF_STATUS. */
6635 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
6637 struct thread_info
*tp
= inferior_thread ();
6638 struct inferior
*inf
= current_inferior ();
6640 if (tp
->control
.step_resume_breakpoint
)
6641 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
6643 if (tp
->control
.exception_resume_breakpoint
)
6644 tp
->control
.exception_resume_breakpoint
->disposition
6645 = disp_del_at_next_stop
;
6647 /* Handle the bpstat_copy of the chain. */
6648 bpstat_clear (&tp
->control
.stop_bpstat
);
6650 tp
->control
= inf_status
->thread_control
;
6651 inf
->control
= inf_status
->inferior_control
;
6654 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
6655 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
6656 stop_after_trap
= inf_status
->stop_after_trap
;
6658 if (target_has_stack
)
6660 /* The point of catch_errors is that if the stack is clobbered,
6661 walking the stack might encounter a garbage pointer and
6662 error() trying to dereference it. */
6664 (restore_selected_frame
, &inf_status
->selected_frame_id
,
6665 "Unable to restore previously selected frame:\n",
6666 RETURN_MASK_ERROR
) == 0)
6667 /* Error in restoring the selected frame. Select the innermost
6669 select_frame (get_current_frame ());
6676 do_restore_infcall_control_state_cleanup (void *sts
)
6678 restore_infcall_control_state (sts
);
6682 make_cleanup_restore_infcall_control_state
6683 (struct infcall_control_state
*inf_status
)
6685 return make_cleanup (do_restore_infcall_control_state_cleanup
, inf_status
);
6689 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
6691 if (inf_status
->thread_control
.step_resume_breakpoint
)
6692 inf_status
->thread_control
.step_resume_breakpoint
->disposition
6693 = disp_del_at_next_stop
;
6695 if (inf_status
->thread_control
.exception_resume_breakpoint
)
6696 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
6697 = disp_del_at_next_stop
;
6699 /* See save_infcall_control_state for info on stop_bpstat. */
6700 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
6706 inferior_has_forked (ptid_t pid
, ptid_t
*child_pid
)
6708 struct target_waitstatus last
;
6711 get_last_target_status (&last_ptid
, &last
);
6713 if (last
.kind
!= TARGET_WAITKIND_FORKED
)
6716 if (!ptid_equal (last_ptid
, pid
))
6719 *child_pid
= last
.value
.related_pid
;
6724 inferior_has_vforked (ptid_t pid
, ptid_t
*child_pid
)
6726 struct target_waitstatus last
;
6729 get_last_target_status (&last_ptid
, &last
);
6731 if (last
.kind
!= TARGET_WAITKIND_VFORKED
)
6734 if (!ptid_equal (last_ptid
, pid
))
6737 *child_pid
= last
.value
.related_pid
;
6742 inferior_has_execd (ptid_t pid
, char **execd_pathname
)
6744 struct target_waitstatus last
;
6747 get_last_target_status (&last_ptid
, &last
);
6749 if (last
.kind
!= TARGET_WAITKIND_EXECD
)
6752 if (!ptid_equal (last_ptid
, pid
))
6755 *execd_pathname
= xstrdup (last
.value
.execd_pathname
);
6760 inferior_has_called_syscall (ptid_t pid
, int *syscall_number
)
6762 struct target_waitstatus last
;
6765 get_last_target_status (&last_ptid
, &last
);
6767 if (last
.kind
!= TARGET_WAITKIND_SYSCALL_ENTRY
&&
6768 last
.kind
!= TARGET_WAITKIND_SYSCALL_RETURN
)
6771 if (!ptid_equal (last_ptid
, pid
))
6774 *syscall_number
= last
.value
.syscall_number
;
6778 /* Oft used ptids */
6780 ptid_t minus_one_ptid
;
6782 /* Create a ptid given the necessary PID, LWP, and TID components. */
6785 ptid_build (int pid
, long lwp
, long tid
)
6795 /* Create a ptid from just a pid. */
6798 pid_to_ptid (int pid
)
6800 return ptid_build (pid
, 0, 0);
6803 /* Fetch the pid (process id) component from a ptid. */
6806 ptid_get_pid (ptid_t ptid
)
6811 /* Fetch the lwp (lightweight process) component from a ptid. */
6814 ptid_get_lwp (ptid_t ptid
)
6819 /* Fetch the tid (thread id) component from a ptid. */
6822 ptid_get_tid (ptid_t ptid
)
6827 /* ptid_equal() is used to test equality of two ptids. */
6830 ptid_equal (ptid_t ptid1
, ptid_t ptid2
)
6832 return (ptid1
.pid
== ptid2
.pid
&& ptid1
.lwp
== ptid2
.lwp
6833 && ptid1
.tid
== ptid2
.tid
);
6836 /* Returns true if PTID represents a process. */
6839 ptid_is_pid (ptid_t ptid
)
6841 if (ptid_equal (minus_one_ptid
, ptid
))
6843 if (ptid_equal (null_ptid
, ptid
))
6846 return (ptid_get_lwp (ptid
) == 0 && ptid_get_tid (ptid
) == 0);
6850 ptid_match (ptid_t ptid
, ptid_t filter
)
6852 if (ptid_equal (filter
, minus_one_ptid
))
6854 if (ptid_is_pid (filter
)
6855 && ptid_get_pid (ptid
) == ptid_get_pid (filter
))
6857 else if (ptid_equal (ptid
, filter
))
6863 /* restore_inferior_ptid() will be used by the cleanup machinery
6864 to restore the inferior_ptid value saved in a call to
6865 save_inferior_ptid(). */
6868 restore_inferior_ptid (void *arg
)
6870 ptid_t
*saved_ptid_ptr
= arg
;
6872 inferior_ptid
= *saved_ptid_ptr
;
6876 /* Save the value of inferior_ptid so that it may be restored by a
6877 later call to do_cleanups(). Returns the struct cleanup pointer
6878 needed for later doing the cleanup. */
6881 save_inferior_ptid (void)
6883 ptid_t
*saved_ptid_ptr
;
6885 saved_ptid_ptr
= xmalloc (sizeof (ptid_t
));
6886 *saved_ptid_ptr
= inferior_ptid
;
6887 return make_cleanup (restore_inferior_ptid
, saved_ptid_ptr
);
6891 /* User interface for reverse debugging:
6892 Set exec-direction / show exec-direction commands
6893 (returns error unless target implements to_set_exec_direction method). */
6895 int execution_direction
= EXEC_FORWARD
;
6896 static const char exec_forward
[] = "forward";
6897 static const char exec_reverse
[] = "reverse";
6898 static const char *exec_direction
= exec_forward
;
6899 static const char *exec_direction_names
[] = {
6906 set_exec_direction_func (char *args
, int from_tty
,
6907 struct cmd_list_element
*cmd
)
6909 if (target_can_execute_reverse
)
6911 if (!strcmp (exec_direction
, exec_forward
))
6912 execution_direction
= EXEC_FORWARD
;
6913 else if (!strcmp (exec_direction
, exec_reverse
))
6914 execution_direction
= EXEC_REVERSE
;
6918 exec_direction
= exec_forward
;
6919 error (_("Target does not support this operation."));
6924 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
6925 struct cmd_list_element
*cmd
, const char *value
)
6927 switch (execution_direction
) {
6929 fprintf_filtered (out
, _("Forward.\n"));
6932 fprintf_filtered (out
, _("Reverse.\n"));
6935 internal_error (__FILE__
, __LINE__
,
6936 _("bogus execution_direction value: %d"),
6937 (int) execution_direction
);
6941 /* User interface for non-stop mode. */
6946 set_non_stop (char *args
, int from_tty
,
6947 struct cmd_list_element
*c
)
6949 if (target_has_execution
)
6951 non_stop_1
= non_stop
;
6952 error (_("Cannot change this setting while the inferior is running."));
6955 non_stop
= non_stop_1
;
6959 show_non_stop (struct ui_file
*file
, int from_tty
,
6960 struct cmd_list_element
*c
, const char *value
)
6962 fprintf_filtered (file
,
6963 _("Controlling the inferior in non-stop mode is %s.\n"),
6968 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
6969 struct cmd_list_element
*c
, const char *value
)
6971 fprintf_filtered (file
, _("Resuming the execution of threads "
6972 "of all processes is %s.\n"), value
);
6976 _initialize_infrun (void)
6981 add_info ("signals", signals_info
, _("\
6982 What debugger does when program gets various signals.\n\
6983 Specify a signal as argument to print info on that signal only."));
6984 add_info_alias ("handle", "signals", 0);
6986 add_com ("handle", class_run
, handle_command
, _("\
6987 Specify how to handle a signal.\n\
6988 Args are signals and actions to apply to those signals.\n\
6989 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
6990 from 1-15 are allowed for compatibility with old versions of GDB.\n\
6991 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
6992 The special arg \"all\" is recognized to mean all signals except those\n\
6993 used by the debugger, typically SIGTRAP and SIGINT.\n\
6994 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
6995 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
6996 Stop means reenter debugger if this signal happens (implies print).\n\
6997 Print means print a message if this signal happens.\n\
6998 Pass means let program see this signal; otherwise program doesn't know.\n\
6999 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7000 Pass and Stop may be combined."));
7003 add_com ("lz", class_info
, signals_info
, _("\
7004 What debugger does when program gets various signals.\n\
7005 Specify a signal as argument to print info on that signal only."));
7006 add_com ("z", class_run
, xdb_handle_command
, _("\
7007 Specify how to handle a signal.\n\
7008 Args are signals and actions to apply to those signals.\n\
7009 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7010 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7011 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7012 The special arg \"all\" is recognized to mean all signals except those\n\
7013 used by the debugger, typically SIGTRAP and SIGINT.\n\
7014 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7015 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7016 nopass), \"Q\" (noprint)\n\
7017 Stop means reenter debugger if this signal happens (implies print).\n\
7018 Print means print a message if this signal happens.\n\
7019 Pass means let program see this signal; otherwise program doesn't know.\n\
7020 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7021 Pass and Stop may be combined."));
7025 stop_command
= add_cmd ("stop", class_obscure
,
7026 not_just_help_class_command
, _("\
7027 There is no `stop' command, but you can set a hook on `stop'.\n\
7028 This allows you to set a list of commands to be run each time execution\n\
7029 of the program stops."), &cmdlist
);
7031 add_setshow_zinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
7032 Set inferior debugging."), _("\
7033 Show inferior debugging."), _("\
7034 When non-zero, inferior specific debugging is enabled."),
7037 &setdebuglist
, &showdebuglist
);
7039 add_setshow_boolean_cmd ("displaced", class_maintenance
,
7040 &debug_displaced
, _("\
7041 Set displaced stepping debugging."), _("\
7042 Show displaced stepping debugging."), _("\
7043 When non-zero, displaced stepping specific debugging is enabled."),
7045 show_debug_displaced
,
7046 &setdebuglist
, &showdebuglist
);
7048 add_setshow_boolean_cmd ("non-stop", no_class
,
7050 Set whether gdb controls the inferior in non-stop mode."), _("\
7051 Show whether gdb controls the inferior in non-stop mode."), _("\
7052 When debugging a multi-threaded program and this setting is\n\
7053 off (the default, also called all-stop mode), when one thread stops\n\
7054 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7055 all other threads in the program while you interact with the thread of\n\
7056 interest. When you continue or step a thread, you can allow the other\n\
7057 threads to run, or have them remain stopped, but while you inspect any\n\
7058 thread's state, all threads stop.\n\
7060 In non-stop mode, when one thread stops, other threads can continue\n\
7061 to run freely. You'll be able to step each thread independently,\n\
7062 leave it stopped or free to run as needed."),
7068 numsigs
= (int) TARGET_SIGNAL_LAST
;
7069 signal_stop
= (unsigned char *) xmalloc (sizeof (signal_stop
[0]) * numsigs
);
7070 signal_print
= (unsigned char *)
7071 xmalloc (sizeof (signal_print
[0]) * numsigs
);
7072 signal_program
= (unsigned char *)
7073 xmalloc (sizeof (signal_program
[0]) * numsigs
);
7074 signal_pass
= (unsigned char *)
7075 xmalloc (sizeof (signal_program
[0]) * numsigs
);
7076 for (i
= 0; i
< numsigs
; i
++)
7079 signal_print
[i
] = 1;
7080 signal_program
[i
] = 1;
7083 /* Signals caused by debugger's own actions
7084 should not be given to the program afterwards. */
7085 signal_program
[TARGET_SIGNAL_TRAP
] = 0;
7086 signal_program
[TARGET_SIGNAL_INT
] = 0;
7088 /* Signals that are not errors should not normally enter the debugger. */
7089 signal_stop
[TARGET_SIGNAL_ALRM
] = 0;
7090 signal_print
[TARGET_SIGNAL_ALRM
] = 0;
7091 signal_stop
[TARGET_SIGNAL_VTALRM
] = 0;
7092 signal_print
[TARGET_SIGNAL_VTALRM
] = 0;
7093 signal_stop
[TARGET_SIGNAL_PROF
] = 0;
7094 signal_print
[TARGET_SIGNAL_PROF
] = 0;
7095 signal_stop
[TARGET_SIGNAL_CHLD
] = 0;
7096 signal_print
[TARGET_SIGNAL_CHLD
] = 0;
7097 signal_stop
[TARGET_SIGNAL_IO
] = 0;
7098 signal_print
[TARGET_SIGNAL_IO
] = 0;
7099 signal_stop
[TARGET_SIGNAL_POLL
] = 0;
7100 signal_print
[TARGET_SIGNAL_POLL
] = 0;
7101 signal_stop
[TARGET_SIGNAL_URG
] = 0;
7102 signal_print
[TARGET_SIGNAL_URG
] = 0;
7103 signal_stop
[TARGET_SIGNAL_WINCH
] = 0;
7104 signal_print
[TARGET_SIGNAL_WINCH
] = 0;
7105 signal_stop
[TARGET_SIGNAL_PRIO
] = 0;
7106 signal_print
[TARGET_SIGNAL_PRIO
] = 0;
7108 /* These signals are used internally by user-level thread
7109 implementations. (See signal(5) on Solaris.) Like the above
7110 signals, a healthy program receives and handles them as part of
7111 its normal operation. */
7112 signal_stop
[TARGET_SIGNAL_LWP
] = 0;
7113 signal_print
[TARGET_SIGNAL_LWP
] = 0;
7114 signal_stop
[TARGET_SIGNAL_WAITING
] = 0;
7115 signal_print
[TARGET_SIGNAL_WAITING
] = 0;
7116 signal_stop
[TARGET_SIGNAL_CANCEL
] = 0;
7117 signal_print
[TARGET_SIGNAL_CANCEL
] = 0;
7119 /* Update cached state. */
7120 signal_cache_update (-1);
7122 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
7123 &stop_on_solib_events
, _("\
7124 Set stopping for shared library events."), _("\
7125 Show stopping for shared library events."), _("\
7126 If nonzero, gdb will give control to the user when the dynamic linker\n\
7127 notifies gdb of shared library events. The most common event of interest\n\
7128 to the user would be loading/unloading of a new library."),
7130 show_stop_on_solib_events
,
7131 &setlist
, &showlist
);
7133 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
7134 follow_fork_mode_kind_names
,
7135 &follow_fork_mode_string
, _("\
7136 Set debugger response to a program call of fork or vfork."), _("\
7137 Show debugger response to a program call of fork or vfork."), _("\
7138 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7139 parent - the original process is debugged after a fork\n\
7140 child - the new process is debugged after a fork\n\
7141 The unfollowed process will continue to run.\n\
7142 By default, the debugger will follow the parent process."),
7144 show_follow_fork_mode_string
,
7145 &setlist
, &showlist
);
7147 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
7148 follow_exec_mode_names
,
7149 &follow_exec_mode_string
, _("\
7150 Set debugger response to a program call of exec."), _("\
7151 Show debugger response to a program call of exec."), _("\
7152 An exec call replaces the program image of a process.\n\
7154 follow-exec-mode can be:\n\
7156 new - the debugger creates a new inferior and rebinds the process\n\
7157 to this new inferior. The program the process was running before\n\
7158 the exec call can be restarted afterwards by restarting the original\n\
7161 same - the debugger keeps the process bound to the same inferior.\n\
7162 The new executable image replaces the previous executable loaded in\n\
7163 the inferior. Restarting the inferior after the exec call restarts\n\
7164 the executable the process was running after the exec call.\n\
7166 By default, the debugger will use the same inferior."),
7168 show_follow_exec_mode_string
,
7169 &setlist
, &showlist
);
7171 add_setshow_enum_cmd ("scheduler-locking", class_run
,
7172 scheduler_enums
, &scheduler_mode
, _("\
7173 Set mode for locking scheduler during execution."), _("\
7174 Show mode for locking scheduler during execution."), _("\
7175 off == no locking (threads may preempt at any time)\n\
7176 on == full locking (no thread except the current thread may run)\n\
7177 step == scheduler locked during every single-step operation.\n\
7178 In this mode, no other thread may run during a step command.\n\
7179 Other threads may run while stepping over a function call ('next')."),
7180 set_schedlock_func
, /* traps on target vector */
7181 show_scheduler_mode
,
7182 &setlist
, &showlist
);
7184 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
7185 Set mode for resuming threads of all processes."), _("\
7186 Show mode for resuming threads of all processes."), _("\
7187 When on, execution commands (such as 'continue' or 'next') resume all\n\
7188 threads of all processes. When off (which is the default), execution\n\
7189 commands only resume the threads of the current process. The set of\n\
7190 threads that are resumed is further refined by the scheduler-locking\n\
7191 mode (see help set scheduler-locking)."),
7193 show_schedule_multiple
,
7194 &setlist
, &showlist
);
7196 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
7197 Set mode of the step operation."), _("\
7198 Show mode of the step operation."), _("\
7199 When set, doing a step over a function without debug line information\n\
7200 will stop at the first instruction of that function. Otherwise, the\n\
7201 function is skipped and the step command stops at a different source line."),
7203 show_step_stop_if_no_debug
,
7204 &setlist
, &showlist
);
7206 add_setshow_enum_cmd ("displaced-stepping", class_run
,
7207 can_use_displaced_stepping_enum
,
7208 &can_use_displaced_stepping
, _("\
7209 Set debugger's willingness to use displaced stepping."), _("\
7210 Show debugger's willingness to use displaced stepping."), _("\
7211 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7212 supported by the target architecture. If off, gdb will not use displaced\n\
7213 stepping to step over breakpoints, even if such is supported by the target\n\
7214 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7215 if the target architecture supports it and non-stop mode is active, but will not\n\
7216 use it in all-stop mode (see help set non-stop)."),
7218 show_can_use_displaced_stepping
,
7219 &setlist
, &showlist
);
7221 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
7222 &exec_direction
, _("Set direction of execution.\n\
7223 Options are 'forward' or 'reverse'."),
7224 _("Show direction of execution (forward/reverse)."),
7225 _("Tells gdb whether to execute forward or backward."),
7226 set_exec_direction_func
, show_exec_direction_func
,
7227 &setlist
, &showlist
);
7229 /* Set/show detach-on-fork: user-settable mode. */
7231 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
7232 Set whether gdb will detach the child of a fork."), _("\
7233 Show whether gdb will detach the child of a fork."), _("\
7234 Tells gdb whether to detach the child of a fork."),
7235 NULL
, NULL
, &setlist
, &showlist
);
7237 /* ptid initializations */
7238 null_ptid
= ptid_build (0, 0, 0);
7239 minus_one_ptid
= ptid_build (-1, 0, 0);
7240 inferior_ptid
= null_ptid
;
7241 target_last_wait_ptid
= minus_one_ptid
;
7243 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed
);
7244 observer_attach_thread_stop_requested (infrun_thread_stop_requested
);
7245 observer_attach_thread_exit (infrun_thread_thread_exit
);
7246 observer_attach_inferior_exit (infrun_inferior_exit
);
7248 /* Explicitly create without lookup, since that tries to create a
7249 value with a void typed value, and when we get here, gdbarch
7250 isn't initialized yet. At this point, we're quite sure there
7251 isn't another convenience variable of the same name. */
7252 create_internalvar_type_lazy ("_siginfo", siginfo_make_value
);
7254 add_setshow_boolean_cmd ("observer", no_class
,
7255 &observer_mode_1
, _("\
7256 Set whether gdb controls the inferior in observer mode."), _("\
7257 Show whether gdb controls the inferior in observer mode."), _("\
7258 In observer mode, GDB can get data from the inferior, but not\n\
7259 affect its execution. Registers and memory may not be changed,\n\
7260 breakpoints may not be set, and the program cannot be interrupted\n\