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. The continations
2397 themselves are responsible for realising the thread
2398 didn't finish what it was supposed to do. */
2399 tp
= inferior_thread ();
2400 do_all_intermediate_continuations_thread (tp
);
2401 do_all_continuations_thread (tp
);
2404 do_cleanups (old_chain
);
2410 /* This function is attached as a "thread_stop_requested" observer.
2411 Cleanup local state that assumed the PTID was to be resumed, and
2412 report the stop to the frontend. */
2415 infrun_thread_stop_requested (ptid_t ptid
)
2417 struct displaced_step_inferior_state
*displaced
;
2419 /* PTID was requested to stop. Remove it from the displaced
2420 stepping queue, so we don't try to resume it automatically. */
2422 for (displaced
= displaced_step_inferior_states
;
2424 displaced
= displaced
->next
)
2426 struct displaced_step_request
*it
, **prev_next_p
;
2428 it
= displaced
->step_request_queue
;
2429 prev_next_p
= &displaced
->step_request_queue
;
2432 if (ptid_match (it
->ptid
, ptid
))
2434 *prev_next_p
= it
->next
;
2440 prev_next_p
= &it
->next
;
2447 iterate_over_threads (infrun_thread_stop_requested_callback
, &ptid
);
2451 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
2453 if (ptid_equal (target_last_wait_ptid
, tp
->ptid
))
2454 nullify_last_target_wait_ptid ();
2457 /* Callback for iterate_over_threads. */
2460 delete_step_resume_breakpoint_callback (struct thread_info
*info
, void *data
)
2462 if (is_exited (info
->ptid
))
2465 delete_step_resume_breakpoint (info
);
2466 delete_exception_resume_breakpoint (info
);
2470 /* In all-stop, delete the step resume breakpoint of any thread that
2471 had one. In non-stop, delete the step resume breakpoint of the
2472 thread that just stopped. */
2475 delete_step_thread_step_resume_breakpoint (void)
2477 if (!target_has_execution
2478 || ptid_equal (inferior_ptid
, null_ptid
))
2479 /* If the inferior has exited, we have already deleted the step
2480 resume breakpoints out of GDB's lists. */
2485 /* If in non-stop mode, only delete the step-resume or
2486 longjmp-resume breakpoint of the thread that just stopped
2488 struct thread_info
*tp
= inferior_thread ();
2490 delete_step_resume_breakpoint (tp
);
2491 delete_exception_resume_breakpoint (tp
);
2494 /* In all-stop mode, delete all step-resume and longjmp-resume
2495 breakpoints of any thread that had them. */
2496 iterate_over_threads (delete_step_resume_breakpoint_callback
, NULL
);
2499 /* A cleanup wrapper. */
2502 delete_step_thread_step_resume_breakpoint_cleanup (void *arg
)
2504 delete_step_thread_step_resume_breakpoint ();
2507 /* Pretty print the results of target_wait, for debugging purposes. */
2510 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
2511 const struct target_waitstatus
*ws
)
2513 char *status_string
= target_waitstatus_to_string (ws
);
2514 struct ui_file
*tmp_stream
= mem_fileopen ();
2517 /* The text is split over several lines because it was getting too long.
2518 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2519 output as a unit; we want only one timestamp printed if debug_timestamp
2522 fprintf_unfiltered (tmp_stream
,
2523 "infrun: target_wait (%d", PIDGET (waiton_ptid
));
2524 if (PIDGET (waiton_ptid
) != -1)
2525 fprintf_unfiltered (tmp_stream
,
2526 " [%s]", target_pid_to_str (waiton_ptid
));
2527 fprintf_unfiltered (tmp_stream
, ", status) =\n");
2528 fprintf_unfiltered (tmp_stream
,
2529 "infrun: %d [%s],\n",
2530 PIDGET (result_ptid
), target_pid_to_str (result_ptid
));
2531 fprintf_unfiltered (tmp_stream
,
2535 text
= ui_file_xstrdup (tmp_stream
, NULL
);
2537 /* This uses %s in part to handle %'s in the text, but also to avoid
2538 a gcc error: the format attribute requires a string literal. */
2539 fprintf_unfiltered (gdb_stdlog
, "%s", text
);
2541 xfree (status_string
);
2543 ui_file_delete (tmp_stream
);
2546 /* Prepare and stabilize the inferior for detaching it. E.g.,
2547 detaching while a thread is displaced stepping is a recipe for
2548 crashing it, as nothing would readjust the PC out of the scratch
2552 prepare_for_detach (void)
2554 struct inferior
*inf
= current_inferior ();
2555 ptid_t pid_ptid
= pid_to_ptid (inf
->pid
);
2556 struct cleanup
*old_chain_1
;
2557 struct displaced_step_inferior_state
*displaced
;
2559 displaced
= get_displaced_stepping_state (inf
->pid
);
2561 /* Is any thread of this process displaced stepping? If not,
2562 there's nothing else to do. */
2563 if (displaced
== NULL
|| ptid_equal (displaced
->step_ptid
, null_ptid
))
2567 fprintf_unfiltered (gdb_stdlog
,
2568 "displaced-stepping in-process while detaching");
2570 old_chain_1
= make_cleanup_restore_integer (&inf
->detaching
);
2573 while (!ptid_equal (displaced
->step_ptid
, null_ptid
))
2575 struct cleanup
*old_chain_2
;
2576 struct execution_control_state ecss
;
2577 struct execution_control_state
*ecs
;
2580 memset (ecs
, 0, sizeof (*ecs
));
2582 overlay_cache_invalid
= 1;
2584 /* We have to invalidate the registers BEFORE calling
2585 target_wait because they can be loaded from the target while
2586 in target_wait. This makes remote debugging a bit more
2587 efficient for those targets that provide critical registers
2588 as part of their normal status mechanism. */
2590 registers_changed ();
2592 if (deprecated_target_wait_hook
)
2593 ecs
->ptid
= deprecated_target_wait_hook (pid_ptid
, &ecs
->ws
, 0);
2595 ecs
->ptid
= target_wait (pid_ptid
, &ecs
->ws
, 0);
2598 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
2600 /* If an error happens while handling the event, propagate GDB's
2601 knowledge of the executing state to the frontend/user running
2603 old_chain_2
= make_cleanup (finish_thread_state_cleanup
,
2606 /* In non-stop mode, each thread is handled individually.
2607 Switch early, so the global state is set correctly for this
2610 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2611 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
2612 context_switch (ecs
->ptid
);
2614 /* Now figure out what to do with the result of the result. */
2615 handle_inferior_event (ecs
);
2617 /* No error, don't finish the state yet. */
2618 discard_cleanups (old_chain_2
);
2620 /* Breakpoints and watchpoints are not installed on the target
2621 at this point, and signals are passed directly to the
2622 inferior, so this must mean the process is gone. */
2623 if (!ecs
->wait_some_more
)
2625 discard_cleanups (old_chain_1
);
2626 error (_("Program exited while detaching"));
2630 discard_cleanups (old_chain_1
);
2633 /* Wait for control to return from inferior to debugger.
2635 If inferior gets a signal, we may decide to start it up again
2636 instead of returning. That is why there is a loop in this function.
2637 When this function actually returns it means the inferior
2638 should be left stopped and GDB should read more commands. */
2641 wait_for_inferior (void)
2643 struct cleanup
*old_cleanups
;
2644 struct execution_control_state ecss
;
2645 struct execution_control_state
*ecs
;
2649 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
2652 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup
, NULL
);
2655 memset (ecs
, 0, sizeof (*ecs
));
2659 struct cleanup
*old_chain
;
2661 /* We have to invalidate the registers BEFORE calling target_wait
2662 because they can be loaded from the target while in target_wait.
2663 This makes remote debugging a bit more efficient for those
2664 targets that provide critical registers as part of their normal
2665 status mechanism. */
2667 overlay_cache_invalid
= 1;
2668 registers_changed ();
2670 if (deprecated_target_wait_hook
)
2671 ecs
->ptid
= deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, 0);
2673 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, 0);
2676 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
2678 /* If an error happens while handling the event, propagate GDB's
2679 knowledge of the executing state to the frontend/user running
2681 old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
2683 if (ecs
->ws
.kind
== TARGET_WAITKIND_SYSCALL_ENTRY
2684 || ecs
->ws
.kind
== TARGET_WAITKIND_SYSCALL_RETURN
)
2685 ecs
->ws
.value
.syscall_number
= UNKNOWN_SYSCALL
;
2687 /* Now figure out what to do with the result of the result. */
2688 handle_inferior_event (ecs
);
2690 /* No error, don't finish the state yet. */
2691 discard_cleanups (old_chain
);
2693 if (!ecs
->wait_some_more
)
2697 do_cleanups (old_cleanups
);
2700 /* Asynchronous version of wait_for_inferior. It is called by the
2701 event loop whenever a change of state is detected on the file
2702 descriptor corresponding to the target. It can be called more than
2703 once to complete a single execution command. In such cases we need
2704 to keep the state in a global variable ECSS. If it is the last time
2705 that this function is called for a single execution command, then
2706 report to the user that the inferior has stopped, and do the
2707 necessary cleanups. */
2710 fetch_inferior_event (void *client_data
)
2712 struct execution_control_state ecss
;
2713 struct execution_control_state
*ecs
= &ecss
;
2714 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
2715 struct cleanup
*ts_old_chain
;
2716 int was_sync
= sync_execution
;
2718 memset (ecs
, 0, sizeof (*ecs
));
2720 /* We're handling a live event, so make sure we're doing live
2721 debugging. If we're looking at traceframes while the target is
2722 running, we're going to need to get back to that mode after
2723 handling the event. */
2726 make_cleanup_restore_current_traceframe ();
2727 set_current_traceframe (-1);
2731 /* In non-stop mode, the user/frontend should not notice a thread
2732 switch due to internal events. Make sure we reverse to the
2733 user selected thread and frame after handling the event and
2734 running any breakpoint commands. */
2735 make_cleanup_restore_current_thread ();
2737 /* We have to invalidate the registers BEFORE calling target_wait
2738 because they can be loaded from the target while in target_wait.
2739 This makes remote debugging a bit more efficient for those
2740 targets that provide critical registers as part of their normal
2741 status mechanism. */
2743 overlay_cache_invalid
= 1;
2744 registers_changed ();
2746 make_cleanup_restore_integer (&execution_direction
);
2747 execution_direction
= target_execution_direction ();
2749 if (deprecated_target_wait_hook
)
2751 deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
2753 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
2756 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
2759 && ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
2760 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2761 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
2762 /* In non-stop mode, each thread is handled individually. Switch
2763 early, so the global state is set correctly for this
2765 context_switch (ecs
->ptid
);
2767 /* If an error happens while handling the event, propagate GDB's
2768 knowledge of the executing state to the frontend/user running
2771 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
2773 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &ecs
->ptid
);
2775 /* Now figure out what to do with the result of the result. */
2776 handle_inferior_event (ecs
);
2778 if (!ecs
->wait_some_more
)
2780 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
2782 delete_step_thread_step_resume_breakpoint ();
2784 /* We may not find an inferior if this was a process exit. */
2785 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
2788 if (target_has_execution
2789 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2790 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
2791 && ecs
->event_thread
->step_multi
2792 && ecs
->event_thread
->control
.stop_step
)
2793 inferior_event_handler (INF_EXEC_CONTINUE
, NULL
);
2795 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2798 /* No error, don't finish the thread states yet. */
2799 discard_cleanups (ts_old_chain
);
2801 /* Revert thread and frame. */
2802 do_cleanups (old_chain
);
2804 /* If the inferior was in sync execution mode, and now isn't,
2805 restore the prompt. */
2806 if (was_sync
&& !sync_execution
)
2807 display_gdb_prompt (0);
2810 /* Record the frame and location we're currently stepping through. */
2812 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
2814 struct thread_info
*tp
= inferior_thread ();
2816 tp
->control
.step_frame_id
= get_frame_id (frame
);
2817 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
2819 tp
->current_symtab
= sal
.symtab
;
2820 tp
->current_line
= sal
.line
;
2823 /* Clear context switchable stepping state. */
2826 init_thread_stepping_state (struct thread_info
*tss
)
2828 tss
->stepping_over_breakpoint
= 0;
2829 tss
->step_after_step_resume_breakpoint
= 0;
2830 tss
->stepping_through_solib_after_catch
= 0;
2831 tss
->stepping_through_solib_catchpoints
= NULL
;
2834 /* Return the cached copy of the last pid/waitstatus returned by
2835 target_wait()/deprecated_target_wait_hook(). The data is actually
2836 cached by handle_inferior_event(), which gets called immediately
2837 after target_wait()/deprecated_target_wait_hook(). */
2840 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
2842 *ptidp
= target_last_wait_ptid
;
2843 *status
= target_last_waitstatus
;
2847 nullify_last_target_wait_ptid (void)
2849 target_last_wait_ptid
= minus_one_ptid
;
2852 /* Switch thread contexts. */
2855 context_switch (ptid_t ptid
)
2859 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
2860 target_pid_to_str (inferior_ptid
));
2861 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
2862 target_pid_to_str (ptid
));
2865 switch_to_thread (ptid
);
2869 adjust_pc_after_break (struct execution_control_state
*ecs
)
2871 struct regcache
*regcache
;
2872 struct gdbarch
*gdbarch
;
2873 struct address_space
*aspace
;
2874 CORE_ADDR breakpoint_pc
;
2876 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2877 we aren't, just return.
2879 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2880 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2881 implemented by software breakpoints should be handled through the normal
2884 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2885 different signals (SIGILL or SIGEMT for instance), but it is less
2886 clear where the PC is pointing afterwards. It may not match
2887 gdbarch_decr_pc_after_break. I don't know any specific target that
2888 generates these signals at breakpoints (the code has been in GDB since at
2889 least 1992) so I can not guess how to handle them here.
2891 In earlier versions of GDB, a target with
2892 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2893 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2894 target with both of these set in GDB history, and it seems unlikely to be
2895 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2897 if (ecs
->ws
.kind
!= TARGET_WAITKIND_STOPPED
)
2900 if (ecs
->ws
.value
.sig
!= TARGET_SIGNAL_TRAP
)
2903 /* In reverse execution, when a breakpoint is hit, the instruction
2904 under it has already been de-executed. The reported PC always
2905 points at the breakpoint address, so adjusting it further would
2906 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2909 B1 0x08000000 : INSN1
2910 B2 0x08000001 : INSN2
2912 PC -> 0x08000003 : INSN4
2914 Say you're stopped at 0x08000003 as above. Reverse continuing
2915 from that point should hit B2 as below. Reading the PC when the
2916 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2917 been de-executed already.
2919 B1 0x08000000 : INSN1
2920 B2 PC -> 0x08000001 : INSN2
2924 We can't apply the same logic as for forward execution, because
2925 we would wrongly adjust the PC to 0x08000000, since there's a
2926 breakpoint at PC - 1. We'd then report a hit on B1, although
2927 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2929 if (execution_direction
== EXEC_REVERSE
)
2932 /* If this target does not decrement the PC after breakpoints, then
2933 we have nothing to do. */
2934 regcache
= get_thread_regcache (ecs
->ptid
);
2935 gdbarch
= get_regcache_arch (regcache
);
2936 if (gdbarch_decr_pc_after_break (gdbarch
) == 0)
2939 aspace
= get_regcache_aspace (regcache
);
2941 /* Find the location where (if we've hit a breakpoint) the
2942 breakpoint would be. */
2943 breakpoint_pc
= regcache_read_pc (regcache
)
2944 - gdbarch_decr_pc_after_break (gdbarch
);
2946 /* Check whether there actually is a software breakpoint inserted at
2949 If in non-stop mode, a race condition is possible where we've
2950 removed a breakpoint, but stop events for that breakpoint were
2951 already queued and arrive later. To suppress those spurious
2952 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
2953 and retire them after a number of stop events are reported. */
2954 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
2955 || (non_stop
&& moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
2957 struct cleanup
*old_cleanups
= NULL
;
2960 old_cleanups
= record_gdb_operation_disable_set ();
2962 /* When using hardware single-step, a SIGTRAP is reported for both
2963 a completed single-step and a software breakpoint. Need to
2964 differentiate between the two, as the latter needs adjusting
2965 but the former does not.
2967 The SIGTRAP can be due to a completed hardware single-step only if
2968 - we didn't insert software single-step breakpoints
2969 - the thread to be examined is still the current thread
2970 - this thread is currently being stepped
2972 If any of these events did not occur, we must have stopped due
2973 to hitting a software breakpoint, and have to back up to the
2976 As a special case, we could have hardware single-stepped a
2977 software breakpoint. In this case (prev_pc == breakpoint_pc),
2978 we also need to back up to the breakpoint address. */
2980 if (singlestep_breakpoints_inserted_p
2981 || !ptid_equal (ecs
->ptid
, inferior_ptid
)
2982 || !currently_stepping (ecs
->event_thread
)
2983 || ecs
->event_thread
->prev_pc
== breakpoint_pc
)
2984 regcache_write_pc (regcache
, breakpoint_pc
);
2987 do_cleanups (old_cleanups
);
2992 init_infwait_state (void)
2994 waiton_ptid
= pid_to_ptid (-1);
2995 infwait_state
= infwait_normal_state
;
2999 error_is_running (void)
3001 error (_("Cannot execute this command while "
3002 "the selected thread is running."));
3006 ensure_not_running (void)
3008 if (is_running (inferior_ptid
))
3009 error_is_running ();
3013 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
3015 for (frame
= get_prev_frame (frame
);
3017 frame
= get_prev_frame (frame
))
3019 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
3021 if (get_frame_type (frame
) != INLINE_FRAME
)
3028 /* Auxiliary function that handles syscall entry/return events.
3029 It returns 1 if the inferior should keep going (and GDB
3030 should ignore the event), or 0 if the event deserves to be
3034 handle_syscall_event (struct execution_control_state
*ecs
)
3036 struct regcache
*regcache
;
3037 struct gdbarch
*gdbarch
;
3040 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3041 context_switch (ecs
->ptid
);
3043 regcache
= get_thread_regcache (ecs
->ptid
);
3044 gdbarch
= get_regcache_arch (regcache
);
3045 syscall_number
= gdbarch_get_syscall_number (gdbarch
, ecs
->ptid
);
3046 stop_pc
= regcache_read_pc (regcache
);
3048 target_last_waitstatus
.value
.syscall_number
= syscall_number
;
3050 if (catch_syscall_enabled () > 0
3051 && catching_syscall_number (syscall_number
) > 0)
3054 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
3057 ecs
->event_thread
->control
.stop_bpstat
3058 = bpstat_stop_status (get_regcache_aspace (regcache
),
3059 stop_pc
, ecs
->ptid
);
3061 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
);
3063 if (!ecs
->random_signal
)
3065 /* Catchpoint hit. */
3066 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_TRAP
;
3071 /* If no catchpoint triggered for this, then keep going. */
3072 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3077 /* Given an execution control state that has been freshly filled in
3078 by an event from the inferior, figure out what it means and take
3079 appropriate action. */
3082 handle_inferior_event (struct execution_control_state
*ecs
)
3084 struct frame_info
*frame
;
3085 struct gdbarch
*gdbarch
;
3086 int sw_single_step_trap_p
= 0;
3087 int stopped_by_watchpoint
;
3088 int stepped_after_stopped_by_watchpoint
= 0;
3089 struct symtab_and_line stop_pc_sal
;
3090 enum stop_kind stop_soon
;
3092 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
3094 /* We had an event in the inferior, but we are not interested in
3095 handling it at this level. The lower layers have already
3096 done what needs to be done, if anything.
3098 One of the possible circumstances for this is when the
3099 inferior produces output for the console. The inferior has
3100 not stopped, and we are ignoring the event. Another possible
3101 circumstance is any event which the lower level knows will be
3102 reported multiple times without an intervening resume. */
3104 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
3105 prepare_to_wait (ecs
);
3109 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
3110 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
3112 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
3115 stop_soon
= inf
->control
.stop_soon
;
3118 stop_soon
= NO_STOP_QUIETLY
;
3120 /* Cache the last pid/waitstatus. */
3121 target_last_wait_ptid
= ecs
->ptid
;
3122 target_last_waitstatus
= ecs
->ws
;
3124 /* Always clear state belonging to the previous time we stopped. */
3125 stop_stack_dummy
= STOP_NONE
;
3127 /* If it's a new process, add it to the thread database. */
3129 ecs
->new_thread_event
= (!ptid_equal (ecs
->ptid
, inferior_ptid
)
3130 && !ptid_equal (ecs
->ptid
, minus_one_ptid
)
3131 && !in_thread_list (ecs
->ptid
));
3133 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
3134 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
&& ecs
->new_thread_event
)
3135 add_thread (ecs
->ptid
);
3137 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
3139 /* Dependent on valid ECS->EVENT_THREAD. */
3140 adjust_pc_after_break (ecs
);
3142 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3143 reinit_frame_cache ();
3145 breakpoint_retire_moribund ();
3147 /* First, distinguish signals caused by the debugger from signals
3148 that have to do with the program's own actions. Note that
3149 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3150 on the operating system version. Here we detect when a SIGILL or
3151 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3152 something similar for SIGSEGV, since a SIGSEGV will be generated
3153 when we're trying to execute a breakpoint instruction on a
3154 non-executable stack. This happens for call dummy breakpoints
3155 for architectures like SPARC that place call dummies on the
3157 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
3158 && (ecs
->ws
.value
.sig
== TARGET_SIGNAL_ILL
3159 || ecs
->ws
.value
.sig
== TARGET_SIGNAL_SEGV
3160 || ecs
->ws
.value
.sig
== TARGET_SIGNAL_EMT
))
3162 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3164 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
3165 regcache_read_pc (regcache
)))
3168 fprintf_unfiltered (gdb_stdlog
,
3169 "infrun: Treating signal as SIGTRAP\n");
3170 ecs
->ws
.value
.sig
= TARGET_SIGNAL_TRAP
;
3174 /* Mark the non-executing threads accordingly. In all-stop, all
3175 threads of all processes are stopped when we get any event
3176 reported. In non-stop mode, only the event thread stops. If
3177 we're handling a process exit in non-stop mode, there's nothing
3178 to do, as threads of the dead process are gone, and threads of
3179 any other process were left running. */
3181 set_executing (minus_one_ptid
, 0);
3182 else if (ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
3183 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
)
3184 set_executing (inferior_ptid
, 0);
3186 switch (infwait_state
)
3188 case infwait_thread_hop_state
:
3190 fprintf_unfiltered (gdb_stdlog
, "infrun: infwait_thread_hop_state\n");
3193 case infwait_normal_state
:
3195 fprintf_unfiltered (gdb_stdlog
, "infrun: infwait_normal_state\n");
3198 case infwait_step_watch_state
:
3200 fprintf_unfiltered (gdb_stdlog
,
3201 "infrun: infwait_step_watch_state\n");
3203 stepped_after_stopped_by_watchpoint
= 1;
3206 case infwait_nonstep_watch_state
:
3208 fprintf_unfiltered (gdb_stdlog
,
3209 "infrun: infwait_nonstep_watch_state\n");
3210 insert_breakpoints ();
3212 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3213 handle things like signals arriving and other things happening
3214 in combination correctly? */
3215 stepped_after_stopped_by_watchpoint
= 1;
3219 internal_error (__FILE__
, __LINE__
, _("bad switch"));
3222 infwait_state
= infwait_normal_state
;
3223 waiton_ptid
= pid_to_ptid (-1);
3225 switch (ecs
->ws
.kind
)
3227 case TARGET_WAITKIND_LOADED
:
3229 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
3230 /* Ignore gracefully during startup of the inferior, as it might
3231 be the shell which has just loaded some objects, otherwise
3232 add the symbols for the newly loaded objects. Also ignore at
3233 the beginning of an attach or remote session; we will query
3234 the full list of libraries once the connection is
3236 if (stop_soon
== NO_STOP_QUIETLY
)
3238 /* Check for any newly added shared libraries if we're
3239 supposed to be adding them automatically. Switch
3240 terminal for any messages produced by
3241 breakpoint_re_set. */
3242 target_terminal_ours_for_output ();
3243 /* NOTE: cagney/2003-11-25: Make certain that the target
3244 stack's section table is kept up-to-date. Architectures,
3245 (e.g., PPC64), use the section table to perform
3246 operations such as address => section name and hence
3247 require the table to contain all sections (including
3248 those found in shared libraries). */
3250 SOLIB_ADD (NULL
, 0, ¤t_target
, auto_solib_add
);
3252 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
3254 target_terminal_inferior ();
3256 /* If requested, stop when the dynamic linker notifies
3257 gdb of events. This allows the user to get control
3258 and place breakpoints in initializer routines for
3259 dynamically loaded objects (among other things). */
3260 if (stop_on_solib_events
)
3262 /* Make sure we print "Stopped due to solib-event" in
3264 stop_print_frame
= 1;
3266 stop_stepping (ecs
);
3270 /* NOTE drow/2007-05-11: This might be a good place to check
3271 for "catch load". */
3274 /* If we are skipping through a shell, or through shared library
3275 loading that we aren't interested in, resume the program. If
3276 we're running the program normally, also resume. But stop if
3277 we're attaching or setting up a remote connection. */
3278 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
3280 /* Loading of shared libraries might have changed breakpoint
3281 addresses. Make sure new breakpoints are inserted. */
3282 if (stop_soon
== NO_STOP_QUIETLY
3283 && !breakpoints_always_inserted_mode ())
3284 insert_breakpoints ();
3285 resume (0, TARGET_SIGNAL_0
);
3286 prepare_to_wait (ecs
);
3292 case TARGET_WAITKIND_SPURIOUS
:
3294 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3295 resume (0, TARGET_SIGNAL_0
);
3296 prepare_to_wait (ecs
);
3299 case TARGET_WAITKIND_EXITED
:
3301 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXITED\n");
3302 inferior_ptid
= ecs
->ptid
;
3303 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs
->ptid
)));
3304 set_current_program_space (current_inferior ()->pspace
);
3305 handle_vfork_child_exec_or_exit (0);
3306 target_terminal_ours (); /* Must do this before mourn anyway. */
3307 print_exited_reason (ecs
->ws
.value
.integer
);
3309 /* Record the exit code in the convenience variable $_exitcode, so
3310 that the user can inspect this again later. */
3311 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3312 (LONGEST
) ecs
->ws
.value
.integer
);
3313 gdb_flush (gdb_stdout
);
3314 target_mourn_inferior ();
3315 singlestep_breakpoints_inserted_p
= 0;
3316 cancel_single_step_breakpoints ();
3317 stop_print_frame
= 0;
3318 stop_stepping (ecs
);
3321 case TARGET_WAITKIND_SIGNALLED
:
3323 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SIGNALLED\n");
3324 inferior_ptid
= ecs
->ptid
;
3325 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs
->ptid
)));
3326 set_current_program_space (current_inferior ()->pspace
);
3327 handle_vfork_child_exec_or_exit (0);
3328 stop_print_frame
= 0;
3329 target_terminal_ours (); /* Must do this before mourn anyway. */
3331 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't
3332 reach here unless the inferior is dead. However, for years
3333 target_kill() was called here, which hints that fatal signals aren't
3334 really fatal on some systems. If that's true, then some changes
3336 target_mourn_inferior ();
3338 print_signal_exited_reason (ecs
->ws
.value
.sig
);
3339 singlestep_breakpoints_inserted_p
= 0;
3340 cancel_single_step_breakpoints ();
3341 stop_stepping (ecs
);
3344 /* The following are the only cases in which we keep going;
3345 the above cases end in a continue or goto. */
3346 case TARGET_WAITKIND_FORKED
:
3347 case TARGET_WAITKIND_VFORKED
:
3349 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
3351 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3353 context_switch (ecs
->ptid
);
3354 reinit_frame_cache ();
3357 /* Immediately detach breakpoints from the child before there's
3358 any chance of letting the user delete breakpoints from the
3359 breakpoint lists. If we don't do this early, it's easy to
3360 leave left over traps in the child, vis: "break foo; catch
3361 fork; c; <fork>; del; c; <child calls foo>". We only follow
3362 the fork on the last `continue', and by that time the
3363 breakpoint at "foo" is long gone from the breakpoint table.
3364 If we vforked, then we don't need to unpatch here, since both
3365 parent and child are sharing the same memory pages; we'll
3366 need to unpatch at follow/detach time instead to be certain
3367 that new breakpoints added between catchpoint hit time and
3368 vfork follow are detached. */
3369 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
3371 int child_pid
= ptid_get_pid (ecs
->ws
.value
.related_pid
);
3373 /* This won't actually modify the breakpoint list, but will
3374 physically remove the breakpoints from the child. */
3375 detach_breakpoints (child_pid
);
3378 if (singlestep_breakpoints_inserted_p
)
3380 /* Pull the single step breakpoints out of the target. */
3381 remove_single_step_breakpoints ();
3382 singlestep_breakpoints_inserted_p
= 0;
3385 /* In case the event is caught by a catchpoint, remember that
3386 the event is to be followed at the next resume of the thread,
3387 and not immediately. */
3388 ecs
->event_thread
->pending_follow
= ecs
->ws
;
3390 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
3392 ecs
->event_thread
->control
.stop_bpstat
3393 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3394 stop_pc
, ecs
->ptid
);
3396 /* Note that we're interested in knowing the bpstat actually
3397 causes a stop, not just if it may explain the signal.
3398 Software watchpoints, for example, always appear in the
3401 = !bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
);
3403 /* If no catchpoint triggered for this, then keep going. */
3404 if (ecs
->random_signal
)
3410 = (follow_fork_mode_string
== follow_fork_mode_child
);
3412 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3414 should_resume
= follow_fork ();
3417 child
= ecs
->ws
.value
.related_pid
;
3419 /* In non-stop mode, also resume the other branch. */
3420 if (non_stop
&& !detach_fork
)
3423 switch_to_thread (parent
);
3425 switch_to_thread (child
);
3427 ecs
->event_thread
= inferior_thread ();
3428 ecs
->ptid
= inferior_ptid
;
3433 switch_to_thread (child
);
3435 switch_to_thread (parent
);
3437 ecs
->event_thread
= inferior_thread ();
3438 ecs
->ptid
= inferior_ptid
;
3443 stop_stepping (ecs
);
3446 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_TRAP
;
3447 goto process_event_stop_test
;
3449 case TARGET_WAITKIND_VFORK_DONE
:
3450 /* Done with the shared memory region. Re-insert breakpoints in
3451 the parent, and keep going. */
3454 fprintf_unfiltered (gdb_stdlog
,
3455 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3457 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3458 context_switch (ecs
->ptid
);
3460 current_inferior ()->waiting_for_vfork_done
= 0;
3461 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
3462 /* This also takes care of reinserting breakpoints in the
3463 previously locked inferior. */
3467 case TARGET_WAITKIND_EXECD
:
3469 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
3471 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3473 context_switch (ecs
->ptid
);
3474 reinit_frame_cache ();
3477 singlestep_breakpoints_inserted_p
= 0;
3478 cancel_single_step_breakpoints ();
3480 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
3482 /* Do whatever is necessary to the parent branch of the vfork. */
3483 handle_vfork_child_exec_or_exit (1);
3485 /* This causes the eventpoints and symbol table to be reset.
3486 Must do this now, before trying to determine whether to
3488 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
3490 ecs
->event_thread
->control
.stop_bpstat
3491 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3492 stop_pc
, ecs
->ptid
);
3494 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
);
3496 /* Note that this may be referenced from inside
3497 bpstat_stop_status above, through inferior_has_execd. */
3498 xfree (ecs
->ws
.value
.execd_pathname
);
3499 ecs
->ws
.value
.execd_pathname
= NULL
;
3501 /* If no catchpoint triggered for this, then keep going. */
3502 if (ecs
->random_signal
)
3504 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3508 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_TRAP
;
3509 goto process_event_stop_test
;
3511 /* Be careful not to try to gather much state about a thread
3512 that's in a syscall. It's frequently a losing proposition. */
3513 case TARGET_WAITKIND_SYSCALL_ENTRY
:
3515 fprintf_unfiltered (gdb_stdlog
,
3516 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3517 /* Getting the current syscall number. */
3518 if (handle_syscall_event (ecs
) != 0)
3520 goto process_event_stop_test
;
3522 /* Before examining the threads further, step this thread to
3523 get it entirely out of the syscall. (We get notice of the
3524 event when the thread is just on the verge of exiting a
3525 syscall. Stepping one instruction seems to get it back
3527 case TARGET_WAITKIND_SYSCALL_RETURN
:
3529 fprintf_unfiltered (gdb_stdlog
,
3530 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3531 if (handle_syscall_event (ecs
) != 0)
3533 goto process_event_stop_test
;
3535 case TARGET_WAITKIND_STOPPED
:
3537 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
3538 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
3541 case TARGET_WAITKIND_NO_HISTORY
:
3542 /* Reverse execution: target ran out of history info. */
3543 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
3544 print_no_history_reason ();
3545 stop_stepping (ecs
);
3549 if (ecs
->new_thread_event
)
3552 /* Non-stop assumes that the target handles adding new threads
3553 to the thread list. */
3554 internal_error (__FILE__
, __LINE__
,
3555 "targets should add new threads to the thread "
3556 "list themselves in non-stop mode.");
3558 /* We may want to consider not doing a resume here in order to
3559 give the user a chance to play with the new thread. It might
3560 be good to make that a user-settable option. */
3562 /* At this point, all threads are stopped (happens automatically
3563 in either the OS or the native code). Therefore we need to
3564 continue all threads in order to make progress. */
3566 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3567 context_switch (ecs
->ptid
);
3568 target_resume (RESUME_ALL
, 0, TARGET_SIGNAL_0
);
3569 prepare_to_wait (ecs
);
3573 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
)
3575 /* Do we need to clean up the state of a thread that has
3576 completed a displaced single-step? (Doing so usually affects
3577 the PC, so do it here, before we set stop_pc.) */
3578 displaced_step_fixup (ecs
->ptid
,
3579 ecs
->event_thread
->suspend
.stop_signal
);
3581 /* If we either finished a single-step or hit a breakpoint, but
3582 the user wanted this thread to be stopped, pretend we got a
3583 SIG0 (generic unsignaled stop). */
3585 if (ecs
->event_thread
->stop_requested
3586 && ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
3587 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3590 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
3594 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
3595 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3596 struct cleanup
*old_chain
= save_inferior_ptid ();
3598 inferior_ptid
= ecs
->ptid
;
3600 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
3601 paddress (gdbarch
, stop_pc
));
3602 if (target_stopped_by_watchpoint ())
3606 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
3608 if (target_stopped_data_address (¤t_target
, &addr
))
3609 fprintf_unfiltered (gdb_stdlog
,
3610 "infrun: stopped data address = %s\n",
3611 paddress (gdbarch
, addr
));
3613 fprintf_unfiltered (gdb_stdlog
,
3614 "infrun: (no data address available)\n");
3617 do_cleanups (old_chain
);
3620 if (stepping_past_singlestep_breakpoint
)
3622 gdb_assert (singlestep_breakpoints_inserted_p
);
3623 gdb_assert (ptid_equal (singlestep_ptid
, ecs
->ptid
));
3624 gdb_assert (!ptid_equal (singlestep_ptid
, saved_singlestep_ptid
));
3626 stepping_past_singlestep_breakpoint
= 0;
3628 /* We've either finished single-stepping past the single-step
3629 breakpoint, or stopped for some other reason. It would be nice if
3630 we could tell, but we can't reliably. */
3631 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
3634 fprintf_unfiltered (gdb_stdlog
,
3635 "infrun: stepping_past_"
3636 "singlestep_breakpoint\n");
3637 /* Pull the single step breakpoints out of the target. */
3638 remove_single_step_breakpoints ();
3639 singlestep_breakpoints_inserted_p
= 0;
3641 ecs
->random_signal
= 0;
3642 ecs
->event_thread
->control
.trap_expected
= 0;
3644 context_switch (saved_singlestep_ptid
);
3645 if (deprecated_context_hook
)
3646 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
3648 resume (1, TARGET_SIGNAL_0
);
3649 prepare_to_wait (ecs
);
3654 if (!ptid_equal (deferred_step_ptid
, null_ptid
))
3656 /* In non-stop mode, there's never a deferred_step_ptid set. */
3657 gdb_assert (!non_stop
);
3659 /* If we stopped for some other reason than single-stepping, ignore
3660 the fact that we were supposed to switch back. */
3661 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
3664 fprintf_unfiltered (gdb_stdlog
,
3665 "infrun: handling deferred step\n");
3667 /* Pull the single step breakpoints out of the target. */
3668 if (singlestep_breakpoints_inserted_p
)
3670 remove_single_step_breakpoints ();
3671 singlestep_breakpoints_inserted_p
= 0;
3674 ecs
->event_thread
->control
.trap_expected
= 0;
3676 /* Note: We do not call context_switch at this point, as the
3677 context is already set up for stepping the original thread. */
3678 switch_to_thread (deferred_step_ptid
);
3679 deferred_step_ptid
= null_ptid
;
3680 /* Suppress spurious "Switching to ..." message. */
3681 previous_inferior_ptid
= inferior_ptid
;
3683 resume (1, TARGET_SIGNAL_0
);
3684 prepare_to_wait (ecs
);
3688 deferred_step_ptid
= null_ptid
;
3691 /* See if a thread hit a thread-specific breakpoint that was meant for
3692 another thread. If so, then step that thread past the breakpoint,
3695 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
3697 int thread_hop_needed
= 0;
3698 struct address_space
*aspace
=
3699 get_regcache_aspace (get_thread_regcache (ecs
->ptid
));
3701 /* Check if a regular breakpoint has been hit before checking
3702 for a potential single step breakpoint. Otherwise, GDB will
3703 not see this breakpoint hit when stepping onto breakpoints. */
3704 if (regular_breakpoint_inserted_here_p (aspace
, stop_pc
))
3706 ecs
->random_signal
= 0;
3707 if (!breakpoint_thread_match (aspace
, stop_pc
, ecs
->ptid
))
3708 thread_hop_needed
= 1;
3710 else if (singlestep_breakpoints_inserted_p
)
3712 /* We have not context switched yet, so this should be true
3713 no matter which thread hit the singlestep breakpoint. */
3714 gdb_assert (ptid_equal (inferior_ptid
, singlestep_ptid
));
3716 fprintf_unfiltered (gdb_stdlog
, "infrun: software single step "
3718 target_pid_to_str (ecs
->ptid
));
3720 ecs
->random_signal
= 0;
3721 /* The call to in_thread_list is necessary because PTIDs sometimes
3722 change when we go from single-threaded to multi-threaded. If
3723 the singlestep_ptid is still in the list, assume that it is
3724 really different from ecs->ptid. */
3725 if (!ptid_equal (singlestep_ptid
, ecs
->ptid
)
3726 && in_thread_list (singlestep_ptid
))
3728 /* If the PC of the thread we were trying to single-step
3729 has changed, discard this event (which we were going
3730 to ignore anyway), and pretend we saw that thread
3731 trap. This prevents us continuously moving the
3732 single-step breakpoint forward, one instruction at a
3733 time. If the PC has changed, then the thread we were
3734 trying to single-step has trapped or been signalled,
3735 but the event has not been reported to GDB yet.
3737 There might be some cases where this loses signal
3738 information, if a signal has arrived at exactly the
3739 same time that the PC changed, but this is the best
3740 we can do with the information available. Perhaps we
3741 should arrange to report all events for all threads
3742 when they stop, or to re-poll the remote looking for
3743 this particular thread (i.e. temporarily enable
3746 CORE_ADDR new_singlestep_pc
3747 = regcache_read_pc (get_thread_regcache (singlestep_ptid
));
3749 if (new_singlestep_pc
!= singlestep_pc
)
3751 enum target_signal stop_signal
;
3754 fprintf_unfiltered (gdb_stdlog
, "infrun: unexpected thread,"
3755 " but expected thread advanced also\n");
3757 /* The current context still belongs to
3758 singlestep_ptid. Don't swap here, since that's
3759 the context we want to use. Just fudge our
3760 state and continue. */
3761 stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
3762 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
3763 ecs
->ptid
= singlestep_ptid
;
3764 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
3765 ecs
->event_thread
->suspend
.stop_signal
= stop_signal
;
3766 stop_pc
= new_singlestep_pc
;
3771 fprintf_unfiltered (gdb_stdlog
,
3772 "infrun: unexpected thread\n");
3774 thread_hop_needed
= 1;
3775 stepping_past_singlestep_breakpoint
= 1;
3776 saved_singlestep_ptid
= singlestep_ptid
;
3781 if (thread_hop_needed
)
3783 struct regcache
*thread_regcache
;
3784 int remove_status
= 0;
3787 fprintf_unfiltered (gdb_stdlog
, "infrun: thread_hop_needed\n");
3789 /* Switch context before touching inferior memory, the
3790 previous thread may have exited. */
3791 if (!ptid_equal (inferior_ptid
, ecs
->ptid
))
3792 context_switch (ecs
->ptid
);
3794 /* Saw a breakpoint, but it was hit by the wrong thread.
3797 if (singlestep_breakpoints_inserted_p
)
3799 /* Pull the single step breakpoints out of the target. */
3800 remove_single_step_breakpoints ();
3801 singlestep_breakpoints_inserted_p
= 0;
3804 /* If the arch can displace step, don't remove the
3806 thread_regcache
= get_thread_regcache (ecs
->ptid
);
3807 if (!use_displaced_stepping (get_regcache_arch (thread_regcache
)))
3808 remove_status
= remove_breakpoints ();
3810 /* Did we fail to remove breakpoints? If so, try
3811 to set the PC past the bp. (There's at least
3812 one situation in which we can fail to remove
3813 the bp's: On HP-UX's that use ttrace, we can't
3814 change the address space of a vforking child
3815 process until the child exits (well, okay, not
3816 then either :-) or execs. */
3817 if (remove_status
!= 0)
3818 error (_("Cannot step over breakpoint hit in wrong thread"));
3823 /* Only need to require the next event from this
3824 thread in all-stop mode. */
3825 waiton_ptid
= ecs
->ptid
;
3826 infwait_state
= infwait_thread_hop_state
;
3829 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3834 else if (singlestep_breakpoints_inserted_p
)
3836 sw_single_step_trap_p
= 1;
3837 ecs
->random_signal
= 0;
3841 ecs
->random_signal
= 1;
3843 /* See if something interesting happened to the non-current thread. If
3844 so, then switch to that thread. */
3845 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3848 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
3850 context_switch (ecs
->ptid
);
3852 if (deprecated_context_hook
)
3853 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
3856 /* At this point, get hold of the now-current thread's frame. */
3857 frame
= get_current_frame ();
3858 gdbarch
= get_frame_arch (frame
);
3860 if (singlestep_breakpoints_inserted_p
)
3862 /* Pull the single step breakpoints out of the target. */
3863 remove_single_step_breakpoints ();
3864 singlestep_breakpoints_inserted_p
= 0;
3867 if (stepped_after_stopped_by_watchpoint
)
3868 stopped_by_watchpoint
= 0;
3870 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
3872 /* If necessary, step over this watchpoint. We'll be back to display
3874 if (stopped_by_watchpoint
3875 && (target_have_steppable_watchpoint
3876 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
3878 /* At this point, we are stopped at an instruction which has
3879 attempted to write to a piece of memory under control of
3880 a watchpoint. The instruction hasn't actually executed
3881 yet. If we were to evaluate the watchpoint expression
3882 now, we would get the old value, and therefore no change
3883 would seem to have occurred.
3885 In order to make watchpoints work `right', we really need
3886 to complete the memory write, and then evaluate the
3887 watchpoint expression. We do this by single-stepping the
3890 It may not be necessary to disable the watchpoint to stop over
3891 it. For example, the PA can (with some kernel cooperation)
3892 single step over a watchpoint without disabling the watchpoint.
3894 It is far more common to need to disable a watchpoint to step
3895 the inferior over it. If we have non-steppable watchpoints,
3896 we must disable the current watchpoint; it's simplest to
3897 disable all watchpoints and breakpoints. */
3900 if (!target_have_steppable_watchpoint
)
3902 remove_breakpoints ();
3903 /* See comment in resume why we need to stop bypassing signals
3904 while breakpoints have been removed. */
3905 target_pass_signals (0, NULL
);
3908 hw_step
= maybe_software_singlestep (gdbarch
, stop_pc
);
3909 target_resume (ecs
->ptid
, hw_step
, TARGET_SIGNAL_0
);
3910 waiton_ptid
= ecs
->ptid
;
3911 if (target_have_steppable_watchpoint
)
3912 infwait_state
= infwait_step_watch_state
;
3914 infwait_state
= infwait_nonstep_watch_state
;
3915 prepare_to_wait (ecs
);
3919 ecs
->stop_func_start
= 0;
3920 ecs
->stop_func_end
= 0;
3921 ecs
->stop_func_name
= 0;
3922 /* Don't care about return value; stop_func_start and stop_func_name
3923 will both be 0 if it doesn't work. */
3924 find_pc_partial_function (stop_pc
, &ecs
->stop_func_name
,
3925 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
3926 ecs
->stop_func_start
3927 += gdbarch_deprecated_function_start_offset (gdbarch
);
3928 ecs
->event_thread
->stepping_over_breakpoint
= 0;
3929 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
3930 ecs
->event_thread
->control
.stop_step
= 0;
3931 stop_print_frame
= 1;
3932 ecs
->random_signal
= 0;
3933 stopped_by_random_signal
= 0;
3935 /* Hide inlined functions starting here, unless we just performed stepi or
3936 nexti. After stepi and nexti, always show the innermost frame (not any
3937 inline function call sites). */
3938 if (ecs
->event_thread
->control
.step_range_end
!= 1)
3939 skip_inline_frames (ecs
->ptid
);
3941 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
3942 && ecs
->event_thread
->control
.trap_expected
3943 && gdbarch_single_step_through_delay_p (gdbarch
)
3944 && currently_stepping (ecs
->event_thread
))
3946 /* We're trying to step off a breakpoint. Turns out that we're
3947 also on an instruction that needs to be stepped multiple
3948 times before it's been fully executing. E.g., architectures
3949 with a delay slot. It needs to be stepped twice, once for
3950 the instruction and once for the delay slot. */
3951 int step_through_delay
3952 = gdbarch_single_step_through_delay (gdbarch
, frame
);
3954 if (debug_infrun
&& step_through_delay
)
3955 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
3956 if (ecs
->event_thread
->control
.step_range_end
== 0
3957 && step_through_delay
)
3959 /* The user issued a continue when stopped at a breakpoint.
3960 Set up for another trap and get out of here. */
3961 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3965 else if (step_through_delay
)
3967 /* The user issued a step when stopped at a breakpoint.
3968 Maybe we should stop, maybe we should not - the delay
3969 slot *might* correspond to a line of source. In any
3970 case, don't decide that here, just set
3971 ecs->stepping_over_breakpoint, making sure we
3972 single-step again before breakpoints are re-inserted. */
3973 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3977 /* Look at the cause of the stop, and decide what to do.
3978 The alternatives are:
3979 1) stop_stepping and return; to really stop and return to the debugger,
3980 2) keep_going and return to start up again
3981 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
3982 3) set ecs->random_signal to 1, and the decision between 1 and 2
3983 will be made according to the signal handling tables. */
3985 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
3986 || stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_NO_SIGSTOP
3987 || stop_soon
== STOP_QUIETLY_REMOTE
)
3989 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
3993 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
3994 stop_print_frame
= 0;
3995 stop_stepping (ecs
);
3999 /* This is originated from start_remote(), start_inferior() and
4000 shared libraries hook functions. */
4001 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
4004 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4005 stop_stepping (ecs
);
4009 /* This originates from attach_command(). We need to overwrite
4010 the stop_signal here, because some kernels don't ignore a
4011 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4012 See more comments in inferior.h. On the other hand, if we
4013 get a non-SIGSTOP, report it to the user - assume the backend
4014 will handle the SIGSTOP if it should show up later.
4016 Also consider that the attach is complete when we see a
4017 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4018 target extended-remote report it instead of a SIGSTOP
4019 (e.g. gdbserver). We already rely on SIGTRAP being our
4020 signal, so this is no exception.
4022 Also consider that the attach is complete when we see a
4023 TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4024 the target to stop all threads of the inferior, in case the
4025 low level attach operation doesn't stop them implicitly. If
4026 they weren't stopped implicitly, then the stub will report a
4027 TARGET_SIGNAL_0, meaning: stopped for no particular reason
4028 other than GDB's request. */
4029 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4030 && (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_STOP
4031 || ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
4032 || ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_0
))
4034 stop_stepping (ecs
);
4035 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
4039 /* See if there is a breakpoint at the current PC. */
4040 ecs
->event_thread
->control
.stop_bpstat
4041 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4042 stop_pc
, ecs
->ptid
);
4044 /* Following in case break condition called a
4046 stop_print_frame
= 1;
4048 /* This is where we handle "moribund" watchpoints. Unlike
4049 software breakpoints traps, hardware watchpoint traps are
4050 always distinguishable from random traps. If no high-level
4051 watchpoint is associated with the reported stop data address
4052 anymore, then the bpstat does not explain the signal ---
4053 simply make sure to ignore it if `stopped_by_watchpoint' is
4057 && ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
4058 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
)
4059 && stopped_by_watchpoint
)
4060 fprintf_unfiltered (gdb_stdlog
,
4061 "infrun: no user watchpoint explains "
4062 "watchpoint SIGTRAP, ignoring\n");
4064 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4065 at one stage in the past included checks for an inferior
4066 function call's call dummy's return breakpoint. The original
4067 comment, that went with the test, read:
4069 ``End of a stack dummy. Some systems (e.g. Sony news) give
4070 another signal besides SIGTRAP, so check here as well as
4073 If someone ever tries to get call dummys on a
4074 non-executable stack to work (where the target would stop
4075 with something like a SIGSEGV), then those tests might need
4076 to be re-instated. Given, however, that the tests were only
4077 enabled when momentary breakpoints were not being used, I
4078 suspect that it won't be the case.
4080 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4081 be necessary for call dummies on a non-executable stack on
4084 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
)
4086 = !(bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
)
4087 || stopped_by_watchpoint
4088 || ecs
->event_thread
->control
.trap_expected
4089 || (ecs
->event_thread
->control
.step_range_end
4090 && (ecs
->event_thread
->control
.step_resume_breakpoint
4094 ecs
->random_signal
= !bpstat_explains_signal
4095 (ecs
->event_thread
->control
.stop_bpstat
);
4096 if (!ecs
->random_signal
)
4097 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_TRAP
;
4101 /* When we reach this point, we've pretty much decided
4102 that the reason for stopping must've been a random
4103 (unexpected) signal. */
4106 ecs
->random_signal
= 1;
4108 process_event_stop_test
:
4110 /* Re-fetch current thread's frame in case we did a
4111 "goto process_event_stop_test" above. */
4112 frame
= get_current_frame ();
4113 gdbarch
= get_frame_arch (frame
);
4115 /* For the program's own signals, act according to
4116 the signal handling tables. */
4118 if (ecs
->random_signal
)
4120 /* Signal not for debugging purposes. */
4122 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
4125 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal %d\n",
4126 ecs
->event_thread
->suspend
.stop_signal
);
4128 stopped_by_random_signal
= 1;
4130 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
4133 target_terminal_ours_for_output ();
4134 print_signal_received_reason
4135 (ecs
->event_thread
->suspend
.stop_signal
);
4137 /* Always stop on signals if we're either just gaining control
4138 of the program, or the user explicitly requested this thread
4139 to remain stopped. */
4140 if (stop_soon
!= NO_STOP_QUIETLY
4141 || ecs
->event_thread
->stop_requested
4143 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
4145 stop_stepping (ecs
);
4148 /* If not going to stop, give terminal back
4149 if we took it away. */
4151 target_terminal_inferior ();
4153 /* Clear the signal if it should not be passed. */
4154 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
4155 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
4157 if (ecs
->event_thread
->prev_pc
== stop_pc
4158 && ecs
->event_thread
->control
.trap_expected
4159 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
4161 /* We were just starting a new sequence, attempting to
4162 single-step off of a breakpoint and expecting a SIGTRAP.
4163 Instead this signal arrives. This signal will take us out
4164 of the stepping range so GDB needs to remember to, when
4165 the signal handler returns, resume stepping off that
4167 /* To simplify things, "continue" is forced to use the same
4168 code paths as single-step - set a breakpoint at the
4169 signal return address and then, once hit, step off that
4172 fprintf_unfiltered (gdb_stdlog
,
4173 "infrun: signal arrived while stepping over "
4176 insert_hp_step_resume_breakpoint_at_frame (frame
);
4177 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
4178 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4179 ecs
->event_thread
->control
.trap_expected
= 0;
4184 if (ecs
->event_thread
->control
.step_range_end
!= 0
4185 && ecs
->event_thread
->suspend
.stop_signal
!= TARGET_SIGNAL_0
4186 && (ecs
->event_thread
->control
.step_range_start
<= stop_pc
4187 && stop_pc
< ecs
->event_thread
->control
.step_range_end
)
4188 && frame_id_eq (get_stack_frame_id (frame
),
4189 ecs
->event_thread
->control
.step_stack_frame_id
)
4190 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
4192 /* The inferior is about to take a signal that will take it
4193 out of the single step range. Set a breakpoint at the
4194 current PC (which is presumably where the signal handler
4195 will eventually return) and then allow the inferior to
4198 Note that this is only needed for a signal delivered
4199 while in the single-step range. Nested signals aren't a
4200 problem as they eventually all return. */
4202 fprintf_unfiltered (gdb_stdlog
,
4203 "infrun: signal may take us out of "
4204 "single-step range\n");
4206 insert_hp_step_resume_breakpoint_at_frame (frame
);
4207 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4208 ecs
->event_thread
->control
.trap_expected
= 0;
4213 /* Note: step_resume_breakpoint may be non-NULL. This occures
4214 when either there's a nested signal, or when there's a
4215 pending signal enabled just as the signal handler returns
4216 (leaving the inferior at the step-resume-breakpoint without
4217 actually executing it). Either way continue until the
4218 breakpoint is really hit. */
4223 /* Handle cases caused by hitting a breakpoint. */
4225 CORE_ADDR jmp_buf_pc
;
4226 struct bpstat_what what
;
4228 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
4230 if (what
.call_dummy
)
4232 stop_stack_dummy
= what
.call_dummy
;
4235 /* If we hit an internal event that triggers symbol changes, the
4236 current frame will be invalidated within bpstat_what (e.g., if
4237 we hit an internal solib event). Re-fetch it. */
4238 frame
= get_current_frame ();
4239 gdbarch
= get_frame_arch (frame
);
4241 switch (what
.main_action
)
4243 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
4244 /* If we hit the breakpoint at longjmp while stepping, we
4245 install a momentary breakpoint at the target of the
4249 fprintf_unfiltered (gdb_stdlog
,
4250 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4252 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4254 if (what
.is_longjmp
)
4256 if (!gdbarch_get_longjmp_target_p (gdbarch
)
4257 || !gdbarch_get_longjmp_target (gdbarch
,
4258 frame
, &jmp_buf_pc
))
4261 fprintf_unfiltered (gdb_stdlog
,
4262 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4263 "(!gdbarch_get_longjmp_target)\n");
4268 /* We're going to replace the current step-resume breakpoint
4269 with a longjmp-resume breakpoint. */
4270 delete_step_resume_breakpoint (ecs
->event_thread
);
4272 /* Insert a breakpoint at resume address. */
4273 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
4277 struct symbol
*func
= get_frame_function (frame
);
4280 check_exception_resume (ecs
, frame
, func
);
4285 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
4287 fprintf_unfiltered (gdb_stdlog
,
4288 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4290 if (what
.is_longjmp
)
4292 gdb_assert (ecs
->event_thread
->control
.step_resume_breakpoint
4294 delete_step_resume_breakpoint (ecs
->event_thread
);
4298 /* There are several cases to consider.
4300 1. The initiating frame no longer exists. In this case
4301 we must stop, because the exception has gone too far.
4303 2. The initiating frame exists, and is the same as the
4304 current frame. We stop, because the exception has been
4307 3. The initiating frame exists and is different from
4308 the current frame. This means the exception has been
4309 caught beneath the initiating frame, so keep going. */
4310 struct frame_info
*init_frame
4311 = frame_find_by_id (ecs
->event_thread
->initiating_frame
);
4313 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
4315 delete_exception_resume_breakpoint (ecs
->event_thread
);
4319 struct frame_id current_id
4320 = get_frame_id (get_current_frame ());
4321 if (frame_id_eq (current_id
,
4322 ecs
->event_thread
->initiating_frame
))
4324 /* Case 2. Fall through. */
4334 /* For Cases 1 and 2, remove the step-resume breakpoint,
4336 delete_step_resume_breakpoint (ecs
->event_thread
);
4339 ecs
->event_thread
->control
.stop_step
= 1;
4340 print_end_stepping_range_reason ();
4341 stop_stepping (ecs
);
4344 case BPSTAT_WHAT_SINGLE
:
4346 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
4347 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4348 /* Still need to check other stuff, at least the case
4349 where we are stepping and step out of the right range. */
4352 case BPSTAT_WHAT_STEP_RESUME
:
4354 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4356 delete_step_resume_breakpoint (ecs
->event_thread
);
4357 if (ecs
->event_thread
->control
.proceed_to_finish
4358 && execution_direction
== EXEC_REVERSE
)
4360 struct thread_info
*tp
= ecs
->event_thread
;
4362 /* We are finishing a function in reverse, and just hit
4363 the step-resume breakpoint at the start address of the
4364 function, and we're almost there -- just need to back
4365 up by one more single-step, which should take us back
4366 to the function call. */
4367 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
4371 if (stop_pc
== ecs
->stop_func_start
4372 && execution_direction
== EXEC_REVERSE
)
4374 /* We are stepping over a function call in reverse, and
4375 just hit the step-resume breakpoint at the start
4376 address of the function. Go back to single-stepping,
4377 which should take us back to the function call. */
4378 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4384 case BPSTAT_WHAT_STOP_NOISY
:
4386 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4387 stop_print_frame
= 1;
4389 /* We are about to nuke the step_resume_breakpointt via the
4390 cleanup chain, so no need to worry about it here. */
4392 stop_stepping (ecs
);
4395 case BPSTAT_WHAT_STOP_SILENT
:
4397 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4398 stop_print_frame
= 0;
4400 /* We are about to nuke the step_resume_breakpoin via the
4401 cleanup chain, so no need to worry about it here. */
4403 stop_stepping (ecs
);
4406 case BPSTAT_WHAT_HP_STEP_RESUME
:
4408 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4410 delete_step_resume_breakpoint (ecs
->event_thread
);
4411 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
4413 /* Back when the step-resume breakpoint was inserted, we
4414 were trying to single-step off a breakpoint. Go back
4416 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
4417 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4423 case BPSTAT_WHAT_KEEP_CHECKING
:
4428 /* We come here if we hit a breakpoint but should not
4429 stop for it. Possibly we also were stepping
4430 and should stop for that. So fall through and
4431 test for stepping. But, if not stepping,
4434 /* In all-stop mode, if we're currently stepping but have stopped in
4435 some other thread, we need to switch back to the stepped thread. */
4438 struct thread_info
*tp
;
4440 tp
= iterate_over_threads (currently_stepping_or_nexting_callback
,
4444 /* However, if the current thread is blocked on some internal
4445 breakpoint, and we simply need to step over that breakpoint
4446 to get it going again, do that first. */
4447 if ((ecs
->event_thread
->control
.trap_expected
4448 && ecs
->event_thread
->suspend
.stop_signal
!= TARGET_SIGNAL_TRAP
)
4449 || ecs
->event_thread
->stepping_over_breakpoint
)
4455 /* If the stepping thread exited, then don't try to switch
4456 back and resume it, which could fail in several different
4457 ways depending on the target. Instead, just keep going.
4459 We can find a stepping dead thread in the thread list in
4462 - The target supports thread exit events, and when the
4463 target tries to delete the thread from the thread list,
4464 inferior_ptid pointed at the exiting thread. In such
4465 case, calling delete_thread does not really remove the
4466 thread from the list; instead, the thread is left listed,
4467 with 'exited' state.
4469 - The target's debug interface does not support thread
4470 exit events, and so we have no idea whatsoever if the
4471 previously stepping thread is still alive. For that
4472 reason, we need to synchronously query the target
4474 if (is_exited (tp
->ptid
)
4475 || !target_thread_alive (tp
->ptid
))
4478 fprintf_unfiltered (gdb_stdlog
,
4479 "infrun: not switching back to "
4480 "stepped thread, it has vanished\n");
4482 delete_thread (tp
->ptid
);
4487 /* Otherwise, we no longer expect a trap in the current thread.
4488 Clear the trap_expected flag before switching back -- this is
4489 what keep_going would do as well, if we called it. */
4490 ecs
->event_thread
->control
.trap_expected
= 0;
4493 fprintf_unfiltered (gdb_stdlog
,
4494 "infrun: switching back to stepped thread\n");
4496 ecs
->event_thread
= tp
;
4497 ecs
->ptid
= tp
->ptid
;
4498 context_switch (ecs
->ptid
);
4504 /* Are we stepping to get the inferior out of the dynamic linker's
4505 hook (and possibly the dld itself) after catching a shlib
4507 if (ecs
->event_thread
->stepping_through_solib_after_catch
)
4509 #if defined(SOLIB_ADD)
4510 /* Have we reached our destination? If not, keep going. */
4511 if (SOLIB_IN_DYNAMIC_LINKER (PIDGET (ecs
->ptid
), stop_pc
))
4514 fprintf_unfiltered (gdb_stdlog
,
4515 "infrun: stepping in dynamic linker\n");
4516 ecs
->event_thread
->stepping_over_breakpoint
= 1;
4522 fprintf_unfiltered (gdb_stdlog
, "infrun: step past dynamic linker\n");
4523 /* Else, stop and report the catchpoint(s) whose triggering
4524 caused us to begin stepping. */
4525 ecs
->event_thread
->stepping_through_solib_after_catch
= 0;
4526 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
4527 ecs
->event_thread
->control
.stop_bpstat
4528 = bpstat_copy (ecs
->event_thread
->stepping_through_solib_catchpoints
);
4529 bpstat_clear (&ecs
->event_thread
->stepping_through_solib_catchpoints
);
4530 stop_print_frame
= 1;
4531 stop_stepping (ecs
);
4535 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
4538 fprintf_unfiltered (gdb_stdlog
,
4539 "infrun: step-resume breakpoint is inserted\n");
4541 /* Having a step-resume breakpoint overrides anything
4542 else having to do with stepping commands until
4543 that breakpoint is reached. */
4548 if (ecs
->event_thread
->control
.step_range_end
== 0)
4551 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
4552 /* Likewise if we aren't even stepping. */
4557 /* Re-fetch current thread's frame in case the code above caused
4558 the frame cache to be re-initialized, making our FRAME variable
4559 a dangling pointer. */
4560 frame
= get_current_frame ();
4561 gdbarch
= get_frame_arch (frame
);
4563 /* If stepping through a line, keep going if still within it.
4565 Note that step_range_end is the address of the first instruction
4566 beyond the step range, and NOT the address of the last instruction
4569 Note also that during reverse execution, we may be stepping
4570 through a function epilogue and therefore must detect when
4571 the current-frame changes in the middle of a line. */
4573 if (stop_pc
>= ecs
->event_thread
->control
.step_range_start
4574 && stop_pc
< ecs
->event_thread
->control
.step_range_end
4575 && (execution_direction
!= EXEC_REVERSE
4576 || frame_id_eq (get_frame_id (frame
),
4577 ecs
->event_thread
->control
.step_frame_id
)))
4581 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
4582 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
4583 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
4585 /* When stepping backward, stop at beginning of line range
4586 (unless it's the function entry point, in which case
4587 keep going back to the call point). */
4588 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
4589 && stop_pc
!= ecs
->stop_func_start
4590 && execution_direction
== EXEC_REVERSE
)
4592 ecs
->event_thread
->control
.stop_step
= 1;
4593 print_end_stepping_range_reason ();
4594 stop_stepping (ecs
);
4602 /* We stepped out of the stepping range. */
4604 /* If we are stepping at the source level and entered the runtime
4605 loader dynamic symbol resolution code...
4607 EXEC_FORWARD: we keep on single stepping until we exit the run
4608 time loader code and reach the callee's address.
4610 EXEC_REVERSE: we've already executed the callee (backward), and
4611 the runtime loader code is handled just like any other
4612 undebuggable function call. Now we need only keep stepping
4613 backward through the trampoline code, and that's handled further
4614 down, so there is nothing for us to do here. */
4616 if (execution_direction
!= EXEC_REVERSE
4617 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
4618 && in_solib_dynsym_resolve_code (stop_pc
))
4620 CORE_ADDR pc_after_resolver
=
4621 gdbarch_skip_solib_resolver (gdbarch
, stop_pc
);
4624 fprintf_unfiltered (gdb_stdlog
,
4625 "infrun: stepped into dynsym resolve code\n");
4627 if (pc_after_resolver
)
4629 /* Set up a step-resume breakpoint at the address
4630 indicated by SKIP_SOLIB_RESOLVER. */
4631 struct symtab_and_line sr_sal
;
4634 sr_sal
.pc
= pc_after_resolver
;
4635 sr_sal
.pspace
= get_frame_program_space (frame
);
4637 insert_step_resume_breakpoint_at_sal (gdbarch
,
4638 sr_sal
, null_frame_id
);
4645 if (ecs
->event_thread
->control
.step_range_end
!= 1
4646 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
4647 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
4648 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
4651 fprintf_unfiltered (gdb_stdlog
,
4652 "infrun: stepped into signal trampoline\n");
4653 /* The inferior, while doing a "step" or "next", has ended up in
4654 a signal trampoline (either by a signal being delivered or by
4655 the signal handler returning). Just single-step until the
4656 inferior leaves the trampoline (either by calling the handler
4662 /* Check for subroutine calls. The check for the current frame
4663 equalling the step ID is not necessary - the check of the
4664 previous frame's ID is sufficient - but it is a common case and
4665 cheaper than checking the previous frame's ID.
4667 NOTE: frame_id_eq will never report two invalid frame IDs as
4668 being equal, so to get into this block, both the current and
4669 previous frame must have valid frame IDs. */
4670 /* The outer_frame_id check is a heuristic to detect stepping
4671 through startup code. If we step over an instruction which
4672 sets the stack pointer from an invalid value to a valid value,
4673 we may detect that as a subroutine call from the mythical
4674 "outermost" function. This could be fixed by marking
4675 outermost frames as !stack_p,code_p,special_p. Then the
4676 initial outermost frame, before sp was valid, would
4677 have code_addr == &_start. See the comment in frame_id_eq
4679 if (!frame_id_eq (get_stack_frame_id (frame
),
4680 ecs
->event_thread
->control
.step_stack_frame_id
)
4681 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4682 ecs
->event_thread
->control
.step_stack_frame_id
)
4683 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
4685 || step_start_function
!= find_pc_function (stop_pc
))))
4687 CORE_ADDR real_stop_pc
;
4690 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
4692 if ((ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
4693 || ((ecs
->event_thread
->control
.step_range_end
== 1)
4694 && in_prologue (gdbarch
, ecs
->event_thread
->prev_pc
,
4695 ecs
->stop_func_start
)))
4697 /* I presume that step_over_calls is only 0 when we're
4698 supposed to be stepping at the assembly language level
4699 ("stepi"). Just stop. */
4700 /* Also, maybe we just did a "nexti" inside a prolog, so we
4701 thought it was a subroutine call but it was not. Stop as
4703 /* And this works the same backward as frontward. MVS */
4704 ecs
->event_thread
->control
.stop_step
= 1;
4705 print_end_stepping_range_reason ();
4706 stop_stepping (ecs
);
4710 /* Reverse stepping through solib trampolines. */
4712 if (execution_direction
== EXEC_REVERSE
4713 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
4714 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
4715 || (ecs
->stop_func_start
== 0
4716 && in_solib_dynsym_resolve_code (stop_pc
))))
4718 /* Any solib trampoline code can be handled in reverse
4719 by simply continuing to single-step. We have already
4720 executed the solib function (backwards), and a few
4721 steps will take us back through the trampoline to the
4727 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
4729 /* We're doing a "next".
4731 Normal (forward) execution: set a breakpoint at the
4732 callee's return address (the address at which the caller
4735 Reverse (backward) execution. set the step-resume
4736 breakpoint at the start of the function that we just
4737 stepped into (backwards), and continue to there. When we
4738 get there, we'll need to single-step back to the caller. */
4740 if (execution_direction
== EXEC_REVERSE
)
4742 struct symtab_and_line sr_sal
;
4744 /* Normal function call return (static or dynamic). */
4746 sr_sal
.pc
= ecs
->stop_func_start
;
4747 sr_sal
.pspace
= get_frame_program_space (frame
);
4748 insert_step_resume_breakpoint_at_sal (gdbarch
,
4749 sr_sal
, null_frame_id
);
4752 insert_step_resume_breakpoint_at_caller (frame
);
4758 /* If we are in a function call trampoline (a stub between the
4759 calling routine and the real function), locate the real
4760 function. That's what tells us (a) whether we want to step
4761 into it at all, and (b) what prologue we want to run to the
4762 end of, if we do step into it. */
4763 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
4764 if (real_stop_pc
== 0)
4765 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
4766 if (real_stop_pc
!= 0)
4767 ecs
->stop_func_start
= real_stop_pc
;
4769 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
4771 struct symtab_and_line sr_sal
;
4774 sr_sal
.pc
= ecs
->stop_func_start
;
4775 sr_sal
.pspace
= get_frame_program_space (frame
);
4777 insert_step_resume_breakpoint_at_sal (gdbarch
,
4778 sr_sal
, null_frame_id
);
4783 /* If we have line number information for the function we are
4784 thinking of stepping into, step into it.
4786 If there are several symtabs at that PC (e.g. with include
4787 files), just want to know whether *any* of them have line
4788 numbers. find_pc_line handles this. */
4790 struct symtab_and_line tmp_sal
;
4792 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
4793 if (tmp_sal
.line
!= 0)
4795 if (execution_direction
== EXEC_REVERSE
)
4796 handle_step_into_function_backward (gdbarch
, ecs
);
4798 handle_step_into_function (gdbarch
, ecs
);
4803 /* If we have no line number and the step-stop-if-no-debug is
4804 set, we stop the step so that the user has a chance to switch
4805 in assembly mode. */
4806 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
4807 && step_stop_if_no_debug
)
4809 ecs
->event_thread
->control
.stop_step
= 1;
4810 print_end_stepping_range_reason ();
4811 stop_stepping (ecs
);
4815 if (execution_direction
== EXEC_REVERSE
)
4817 /* Set a breakpoint at callee's start address.
4818 From there we can step once and be back in the caller. */
4819 struct symtab_and_line sr_sal
;
4822 sr_sal
.pc
= ecs
->stop_func_start
;
4823 sr_sal
.pspace
= get_frame_program_space (frame
);
4824 insert_step_resume_breakpoint_at_sal (gdbarch
,
4825 sr_sal
, null_frame_id
);
4828 /* Set a breakpoint at callee's return address (the address
4829 at which the caller will resume). */
4830 insert_step_resume_breakpoint_at_caller (frame
);
4836 /* Reverse stepping through solib trampolines. */
4838 if (execution_direction
== EXEC_REVERSE
4839 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
4841 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
4842 || (ecs
->stop_func_start
== 0
4843 && in_solib_dynsym_resolve_code (stop_pc
)))
4845 /* Any solib trampoline code can be handled in reverse
4846 by simply continuing to single-step. We have already
4847 executed the solib function (backwards), and a few
4848 steps will take us back through the trampoline to the
4853 else if (in_solib_dynsym_resolve_code (stop_pc
))
4855 /* Stepped backward into the solib dynsym resolver.
4856 Set a breakpoint at its start and continue, then
4857 one more step will take us out. */
4858 struct symtab_and_line sr_sal
;
4861 sr_sal
.pc
= ecs
->stop_func_start
;
4862 sr_sal
.pspace
= get_frame_program_space (frame
);
4863 insert_step_resume_breakpoint_at_sal (gdbarch
,
4864 sr_sal
, null_frame_id
);
4870 /* If we're in the return path from a shared library trampoline,
4871 we want to proceed through the trampoline when stepping. */
4872 if (gdbarch_in_solib_return_trampoline (gdbarch
,
4873 stop_pc
, ecs
->stop_func_name
))
4875 /* Determine where this trampoline returns. */
4876 CORE_ADDR real_stop_pc
;
4878 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
4881 fprintf_unfiltered (gdb_stdlog
,
4882 "infrun: stepped into solib return tramp\n");
4884 /* Only proceed through if we know where it's going. */
4887 /* And put the step-breakpoint there and go until there. */
4888 struct symtab_and_line sr_sal
;
4890 init_sal (&sr_sal
); /* initialize to zeroes */
4891 sr_sal
.pc
= real_stop_pc
;
4892 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
4893 sr_sal
.pspace
= get_frame_program_space (frame
);
4895 /* Do not specify what the fp should be when we stop since
4896 on some machines the prologue is where the new fp value
4898 insert_step_resume_breakpoint_at_sal (gdbarch
,
4899 sr_sal
, null_frame_id
);
4901 /* Restart without fiddling with the step ranges or
4908 stop_pc_sal
= find_pc_line (stop_pc
, 0);
4910 /* NOTE: tausq/2004-05-24: This if block used to be done before all
4911 the trampoline processing logic, however, there are some trampolines
4912 that have no names, so we should do trampoline handling first. */
4913 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
4914 && ecs
->stop_func_name
== NULL
4915 && stop_pc_sal
.line
== 0)
4918 fprintf_unfiltered (gdb_stdlog
,
4919 "infrun: stepped into undebuggable function\n");
4921 /* The inferior just stepped into, or returned to, an
4922 undebuggable function (where there is no debugging information
4923 and no line number corresponding to the address where the
4924 inferior stopped). Since we want to skip this kind of code,
4925 we keep going until the inferior returns from this
4926 function - unless the user has asked us not to (via
4927 set step-mode) or we no longer know how to get back
4928 to the call site. */
4929 if (step_stop_if_no_debug
4930 || !frame_id_p (frame_unwind_caller_id (frame
)))
4932 /* If we have no line number and the step-stop-if-no-debug
4933 is set, we stop the step so that the user has a chance to
4934 switch in assembly mode. */
4935 ecs
->event_thread
->control
.stop_step
= 1;
4936 print_end_stepping_range_reason ();
4937 stop_stepping (ecs
);
4942 /* Set a breakpoint at callee's return address (the address
4943 at which the caller will resume). */
4944 insert_step_resume_breakpoint_at_caller (frame
);
4950 if (ecs
->event_thread
->control
.step_range_end
== 1)
4952 /* It is stepi or nexti. We always want to stop stepping after
4955 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
4956 ecs
->event_thread
->control
.stop_step
= 1;
4957 print_end_stepping_range_reason ();
4958 stop_stepping (ecs
);
4962 if (stop_pc_sal
.line
== 0)
4964 /* We have no line number information. That means to stop
4965 stepping (does this always happen right after one instruction,
4966 when we do "s" in a function with no line numbers,
4967 or can this happen as a result of a return or longjmp?). */
4969 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
4970 ecs
->event_thread
->control
.stop_step
= 1;
4971 print_end_stepping_range_reason ();
4972 stop_stepping (ecs
);
4976 /* Look for "calls" to inlined functions, part one. If the inline
4977 frame machinery detected some skipped call sites, we have entered
4978 a new inline function. */
4980 if (frame_id_eq (get_frame_id (get_current_frame ()),
4981 ecs
->event_thread
->control
.step_frame_id
)
4982 && inline_skipped_frames (ecs
->ptid
))
4984 struct symtab_and_line call_sal
;
4987 fprintf_unfiltered (gdb_stdlog
,
4988 "infrun: stepped into inlined function\n");
4990 find_frame_sal (get_current_frame (), &call_sal
);
4992 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
4994 /* For "step", we're going to stop. But if the call site
4995 for this inlined function is on the same source line as
4996 we were previously stepping, go down into the function
4997 first. Otherwise stop at the call site. */
4999 if (call_sal
.line
== ecs
->event_thread
->current_line
5000 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
5001 step_into_inline_frame (ecs
->ptid
);
5003 ecs
->event_thread
->control
.stop_step
= 1;
5004 print_end_stepping_range_reason ();
5005 stop_stepping (ecs
);
5010 /* For "next", we should stop at the call site if it is on a
5011 different source line. Otherwise continue through the
5012 inlined function. */
5013 if (call_sal
.line
== ecs
->event_thread
->current_line
5014 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
5018 ecs
->event_thread
->control
.stop_step
= 1;
5019 print_end_stepping_range_reason ();
5020 stop_stepping (ecs
);
5026 /* Look for "calls" to inlined functions, part two. If we are still
5027 in the same real function we were stepping through, but we have
5028 to go further up to find the exact frame ID, we are stepping
5029 through a more inlined call beyond its call site. */
5031 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5032 && !frame_id_eq (get_frame_id (get_current_frame ()),
5033 ecs
->event_thread
->control
.step_frame_id
)
5034 && stepped_in_from (get_current_frame (),
5035 ecs
->event_thread
->control
.step_frame_id
))
5038 fprintf_unfiltered (gdb_stdlog
,
5039 "infrun: stepping through inlined function\n");
5041 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
5045 ecs
->event_thread
->control
.stop_step
= 1;
5046 print_end_stepping_range_reason ();
5047 stop_stepping (ecs
);
5052 if ((stop_pc
== stop_pc_sal
.pc
)
5053 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
5054 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
5056 /* We are at the start of a different line. So stop. Note that
5057 we don't stop if we step into the middle of a different line.
5058 That is said to make things like for (;;) statements work
5061 fprintf_unfiltered (gdb_stdlog
,
5062 "infrun: stepped to a different line\n");
5063 ecs
->event_thread
->control
.stop_step
= 1;
5064 print_end_stepping_range_reason ();
5065 stop_stepping (ecs
);
5069 /* We aren't done stepping.
5071 Optimize by setting the stepping range to the line.
5072 (We might not be in the original line, but if we entered a
5073 new line in mid-statement, we continue stepping. This makes
5074 things like for(;;) statements work better.) */
5076 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
5077 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
5078 set_step_info (frame
, stop_pc_sal
);
5081 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
5085 /* Is thread TP in the middle of single-stepping? */
5088 currently_stepping (struct thread_info
*tp
)
5090 return ((tp
->control
.step_range_end
5091 && tp
->control
.step_resume_breakpoint
== NULL
)
5092 || tp
->control
.trap_expected
5093 || tp
->stepping_through_solib_after_catch
5094 || bpstat_should_step ());
5097 /* Returns true if any thread *but* the one passed in "data" is in the
5098 middle of stepping or of handling a "next". */
5101 currently_stepping_or_nexting_callback (struct thread_info
*tp
, void *data
)
5106 return (tp
->control
.step_range_end
5107 || tp
->control
.trap_expected
5108 || tp
->stepping_through_solib_after_catch
);
5111 /* Inferior has stepped into a subroutine call with source code that
5112 we should not step over. Do step to the first line of code in
5116 handle_step_into_function (struct gdbarch
*gdbarch
,
5117 struct execution_control_state
*ecs
)
5120 struct symtab_and_line stop_func_sal
, sr_sal
;
5122 s
= find_pc_symtab (stop_pc
);
5123 if (s
&& s
->language
!= language_asm
)
5124 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
5125 ecs
->stop_func_start
);
5127 stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
5128 /* Use the step_resume_break to step until the end of the prologue,
5129 even if that involves jumps (as it seems to on the vax under
5131 /* If the prologue ends in the middle of a source line, continue to
5132 the end of that source line (if it is still within the function).
5133 Otherwise, just go to end of prologue. */
5134 if (stop_func_sal
.end
5135 && stop_func_sal
.pc
!= ecs
->stop_func_start
5136 && stop_func_sal
.end
< ecs
->stop_func_end
)
5137 ecs
->stop_func_start
= stop_func_sal
.end
;
5139 /* Architectures which require breakpoint adjustment might not be able
5140 to place a breakpoint at the computed address. If so, the test
5141 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5142 ecs->stop_func_start to an address at which a breakpoint may be
5143 legitimately placed.
5145 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5146 made, GDB will enter an infinite loop when stepping through
5147 optimized code consisting of VLIW instructions which contain
5148 subinstructions corresponding to different source lines. On
5149 FR-V, it's not permitted to place a breakpoint on any but the
5150 first subinstruction of a VLIW instruction. When a breakpoint is
5151 set, GDB will adjust the breakpoint address to the beginning of
5152 the VLIW instruction. Thus, we need to make the corresponding
5153 adjustment here when computing the stop address. */
5155 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
5157 ecs
->stop_func_start
5158 = gdbarch_adjust_breakpoint_address (gdbarch
,
5159 ecs
->stop_func_start
);
5162 if (ecs
->stop_func_start
== stop_pc
)
5164 /* We are already there: stop now. */
5165 ecs
->event_thread
->control
.stop_step
= 1;
5166 print_end_stepping_range_reason ();
5167 stop_stepping (ecs
);
5172 /* Put the step-breakpoint there and go until there. */
5173 init_sal (&sr_sal
); /* initialize to zeroes */
5174 sr_sal
.pc
= ecs
->stop_func_start
;
5175 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
5176 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
5178 /* Do not specify what the fp should be when we stop since on
5179 some machines the prologue is where the new fp value is
5181 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
5183 /* And make sure stepping stops right away then. */
5184 ecs
->event_thread
->control
.step_range_end
5185 = ecs
->event_thread
->control
.step_range_start
;
5190 /* Inferior has stepped backward into a subroutine call with source
5191 code that we should not step over. Do step to the beginning of the
5192 last line of code in it. */
5195 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
5196 struct execution_control_state
*ecs
)
5199 struct symtab_and_line stop_func_sal
;
5201 s
= find_pc_symtab (stop_pc
);
5202 if (s
&& s
->language
!= language_asm
)
5203 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
5204 ecs
->stop_func_start
);
5206 stop_func_sal
= find_pc_line (stop_pc
, 0);
5208 /* OK, we're just going to keep stepping here. */
5209 if (stop_func_sal
.pc
== stop_pc
)
5211 /* We're there already. Just stop stepping now. */
5212 ecs
->event_thread
->control
.stop_step
= 1;
5213 print_end_stepping_range_reason ();
5214 stop_stepping (ecs
);
5218 /* Else just reset the step range and keep going.
5219 No step-resume breakpoint, they don't work for
5220 epilogues, which can have multiple entry paths. */
5221 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
5222 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
5228 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5229 This is used to both functions and to skip over code. */
5232 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
5233 struct symtab_and_line sr_sal
,
5234 struct frame_id sr_id
,
5235 enum bptype sr_type
)
5237 /* There should never be more than one step-resume or longjmp-resume
5238 breakpoint per thread, so we should never be setting a new
5239 step_resume_breakpoint when one is already active. */
5240 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
5241 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
5244 fprintf_unfiltered (gdb_stdlog
,
5245 "infrun: inserting step-resume breakpoint at %s\n",
5246 paddress (gdbarch
, sr_sal
.pc
));
5248 inferior_thread ()->control
.step_resume_breakpoint
5249 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
);
5253 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
5254 struct symtab_and_line sr_sal
,
5255 struct frame_id sr_id
)
5257 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
5262 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5263 This is used to skip a potential signal handler.
5265 This is called with the interrupted function's frame. The signal
5266 handler, when it returns, will resume the interrupted function at
5270 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
5272 struct symtab_and_line sr_sal
;
5273 struct gdbarch
*gdbarch
;
5275 gdb_assert (return_frame
!= NULL
);
5276 init_sal (&sr_sal
); /* initialize to zeros */
5278 gdbarch
= get_frame_arch (return_frame
);
5279 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
5280 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
5281 sr_sal
.pspace
= get_frame_program_space (return_frame
);
5283 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
5284 get_stack_frame_id (return_frame
),
5288 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5289 is used to skip a function after stepping into it (for "next" or if
5290 the called function has no debugging information).
5292 The current function has almost always been reached by single
5293 stepping a call or return instruction. NEXT_FRAME belongs to the
5294 current function, and the breakpoint will be set at the caller's
5297 This is a separate function rather than reusing
5298 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5299 get_prev_frame, which may stop prematurely (see the implementation
5300 of frame_unwind_caller_id for an example). */
5303 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
5305 struct symtab_and_line sr_sal
;
5306 struct gdbarch
*gdbarch
;
5308 /* We shouldn't have gotten here if we don't know where the call site
5310 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
5312 init_sal (&sr_sal
); /* initialize to zeros */
5314 gdbarch
= frame_unwind_caller_arch (next_frame
);
5315 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
5316 frame_unwind_caller_pc (next_frame
));
5317 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
5318 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
5320 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
5321 frame_unwind_caller_id (next_frame
));
5324 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5325 new breakpoint at the target of a jmp_buf. The handling of
5326 longjmp-resume uses the same mechanisms used for handling
5327 "step-resume" breakpoints. */
5330 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
5332 /* There should never be more than one step-resume or longjmp-resume
5333 breakpoint per thread, so we should never be setting a new
5334 longjmp_resume_breakpoint when one is already active. */
5335 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
5338 fprintf_unfiltered (gdb_stdlog
,
5339 "infrun: inserting longjmp-resume breakpoint at %s\n",
5340 paddress (gdbarch
, pc
));
5342 inferior_thread ()->control
.step_resume_breakpoint
=
5343 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
);
5346 /* Insert an exception resume breakpoint. TP is the thread throwing
5347 the exception. The block B is the block of the unwinder debug hook
5348 function. FRAME is the frame corresponding to the call to this
5349 function. SYM is the symbol of the function argument holding the
5350 target PC of the exception. */
5353 insert_exception_resume_breakpoint (struct thread_info
*tp
,
5355 struct frame_info
*frame
,
5358 struct gdb_exception e
;
5360 /* We want to ignore errors here. */
5361 TRY_CATCH (e
, RETURN_MASK_ERROR
)
5363 struct symbol
*vsym
;
5364 struct value
*value
;
5366 struct breakpoint
*bp
;
5368 vsym
= lookup_symbol (SYMBOL_LINKAGE_NAME (sym
), b
, VAR_DOMAIN
, NULL
);
5369 value
= read_var_value (vsym
, frame
);
5370 /* If the value was optimized out, revert to the old behavior. */
5371 if (! value_optimized_out (value
))
5373 handler
= value_as_address (value
);
5376 fprintf_unfiltered (gdb_stdlog
,
5377 "infrun: exception resume at %lx\n",
5378 (unsigned long) handler
);
5380 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
5381 handler
, bp_exception_resume
);
5382 bp
->thread
= tp
->num
;
5383 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
5388 /* This is called when an exception has been intercepted. Check to
5389 see whether the exception's destination is of interest, and if so,
5390 set an exception resume breakpoint there. */
5393 check_exception_resume (struct execution_control_state
*ecs
,
5394 struct frame_info
*frame
, struct symbol
*func
)
5396 struct gdb_exception e
;
5398 TRY_CATCH (e
, RETURN_MASK_ERROR
)
5401 struct dict_iterator iter
;
5405 /* The exception breakpoint is a thread-specific breakpoint on
5406 the unwinder's debug hook, declared as:
5408 void _Unwind_DebugHook (void *cfa, void *handler);
5410 The CFA argument indicates the frame to which control is
5411 about to be transferred. HANDLER is the destination PC.
5413 We ignore the CFA and set a temporary breakpoint at HANDLER.
5414 This is not extremely efficient but it avoids issues in gdb
5415 with computing the DWARF CFA, and it also works even in weird
5416 cases such as throwing an exception from inside a signal
5419 b
= SYMBOL_BLOCK_VALUE (func
);
5420 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
5422 if (!SYMBOL_IS_ARGUMENT (sym
))
5429 insert_exception_resume_breakpoint (ecs
->event_thread
,
5438 stop_stepping (struct execution_control_state
*ecs
)
5441 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_stepping\n");
5443 /* Let callers know we don't want to wait for the inferior anymore. */
5444 ecs
->wait_some_more
= 0;
5447 /* This function handles various cases where we need to continue
5448 waiting for the inferior. */
5449 /* (Used to be the keep_going: label in the old wait_for_inferior). */
5452 keep_going (struct execution_control_state
*ecs
)
5454 /* Make sure normal_stop is called if we get a QUIT handled before
5456 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
5458 /* Save the pc before execution, to compare with pc after stop. */
5459 ecs
->event_thread
->prev_pc
5460 = regcache_read_pc (get_thread_regcache (ecs
->ptid
));
5462 /* If we did not do break;, it means we should keep running the
5463 inferior and not return to debugger. */
5465 if (ecs
->event_thread
->control
.trap_expected
5466 && ecs
->event_thread
->suspend
.stop_signal
!= TARGET_SIGNAL_TRAP
)
5468 /* We took a signal (which we are supposed to pass through to
5469 the inferior, else we'd not get here) and we haven't yet
5470 gotten our trap. Simply continue. */
5472 discard_cleanups (old_cleanups
);
5473 resume (currently_stepping (ecs
->event_thread
),
5474 ecs
->event_thread
->suspend
.stop_signal
);
5478 /* Either the trap was not expected, but we are continuing
5479 anyway (the user asked that this signal be passed to the
5482 The signal was SIGTRAP, e.g. it was our signal, but we
5483 decided we should resume from it.
5485 We're going to run this baby now!
5487 Note that insert_breakpoints won't try to re-insert
5488 already inserted breakpoints. Therefore, we don't
5489 care if breakpoints were already inserted, or not. */
5491 if (ecs
->event_thread
->stepping_over_breakpoint
)
5493 struct regcache
*thread_regcache
= get_thread_regcache (ecs
->ptid
);
5495 if (!use_displaced_stepping (get_regcache_arch (thread_regcache
)))
5496 /* Since we can't do a displaced step, we have to remove
5497 the breakpoint while we step it. To keep things
5498 simple, we remove them all. */
5499 remove_breakpoints ();
5503 struct gdb_exception e
;
5505 /* Stop stepping when inserting breakpoints
5507 TRY_CATCH (e
, RETURN_MASK_ERROR
)
5509 insert_breakpoints ();
5513 exception_print (gdb_stderr
, e
);
5514 stop_stepping (ecs
);
5519 ecs
->event_thread
->control
.trap_expected
5520 = ecs
->event_thread
->stepping_over_breakpoint
;
5522 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5523 specifies that such a signal should be delivered to the
5526 Typically, this would occure when a user is debugging a
5527 target monitor on a simulator: the target monitor sets a
5528 breakpoint; the simulator encounters this break-point and
5529 halts the simulation handing control to GDB; GDB, noteing
5530 that the break-point isn't valid, returns control back to the
5531 simulator; the simulator then delivers the hardware
5532 equivalent of a SIGNAL_TRAP to the program being debugged. */
5534 if (ecs
->event_thread
->suspend
.stop_signal
== TARGET_SIGNAL_TRAP
5535 && !signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
5536 ecs
->event_thread
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
5538 discard_cleanups (old_cleanups
);
5539 resume (currently_stepping (ecs
->event_thread
),
5540 ecs
->event_thread
->suspend
.stop_signal
);
5543 prepare_to_wait (ecs
);
5546 /* This function normally comes after a resume, before
5547 handle_inferior_event exits. It takes care of any last bits of
5548 housekeeping, and sets the all-important wait_some_more flag. */
5551 prepare_to_wait (struct execution_control_state
*ecs
)
5554 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
5556 /* This is the old end of the while loop. Let everybody know we
5557 want to wait for the inferior some more and get called again
5559 ecs
->wait_some_more
= 1;
5562 /* Several print_*_reason functions to print why the inferior has stopped.
5563 We always print something when the inferior exits, or receives a signal.
5564 The rest of the cases are dealt with later on in normal_stop and
5565 print_it_typical. Ideally there should be a call to one of these
5566 print_*_reason functions functions from handle_inferior_event each time
5567 stop_stepping is called. */
5569 /* Print why the inferior has stopped.
5570 We are done with a step/next/si/ni command, print why the inferior has
5571 stopped. For now print nothing. Print a message only if not in the middle
5572 of doing a "step n" operation for n > 1. */
5575 print_end_stepping_range_reason (void)
5577 if ((!inferior_thread ()->step_multi
5578 || !inferior_thread ()->control
.stop_step
)
5579 && ui_out_is_mi_like_p (uiout
))
5580 ui_out_field_string (uiout
, "reason",
5581 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
5584 /* The inferior was terminated by a signal, print why it stopped. */
5587 print_signal_exited_reason (enum target_signal siggnal
)
5589 annotate_signalled ();
5590 if (ui_out_is_mi_like_p (uiout
))
5592 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
5593 ui_out_text (uiout
, "\nProgram terminated with signal ");
5594 annotate_signal_name ();
5595 ui_out_field_string (uiout
, "signal-name",
5596 target_signal_to_name (siggnal
));
5597 annotate_signal_name_end ();
5598 ui_out_text (uiout
, ", ");
5599 annotate_signal_string ();
5600 ui_out_field_string (uiout
, "signal-meaning",
5601 target_signal_to_string (siggnal
));
5602 annotate_signal_string_end ();
5603 ui_out_text (uiout
, ".\n");
5604 ui_out_text (uiout
, "The program no longer exists.\n");
5607 /* The inferior program is finished, print why it stopped. */
5610 print_exited_reason (int exitstatus
)
5612 struct inferior
*inf
= current_inferior ();
5613 const char *pidstr
= target_pid_to_str (pid_to_ptid (inf
->pid
));
5615 annotate_exited (exitstatus
);
5618 if (ui_out_is_mi_like_p (uiout
))
5619 ui_out_field_string (uiout
, "reason",
5620 async_reason_lookup (EXEC_ASYNC_EXITED
));
5621 ui_out_text (uiout
, "[Inferior ");
5622 ui_out_text (uiout
, plongest (inf
->num
));
5623 ui_out_text (uiout
, " (");
5624 ui_out_text (uiout
, pidstr
);
5625 ui_out_text (uiout
, ") exited with code ");
5626 ui_out_field_fmt (uiout
, "exit-code", "0%o", (unsigned int) exitstatus
);
5627 ui_out_text (uiout
, "]\n");
5631 if (ui_out_is_mi_like_p (uiout
))
5633 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
5634 ui_out_text (uiout
, "[Inferior ");
5635 ui_out_text (uiout
, plongest (inf
->num
));
5636 ui_out_text (uiout
, " (");
5637 ui_out_text (uiout
, pidstr
);
5638 ui_out_text (uiout
, ") exited normally]\n");
5640 /* Support the --return-child-result option. */
5641 return_child_result_value
= exitstatus
;
5644 /* Signal received, print why the inferior has stopped. The signal table
5645 tells us to print about it. */
5648 print_signal_received_reason (enum target_signal siggnal
)
5652 if (siggnal
== TARGET_SIGNAL_0
&& !ui_out_is_mi_like_p (uiout
))
5654 struct thread_info
*t
= inferior_thread ();
5656 ui_out_text (uiout
, "\n[");
5657 ui_out_field_string (uiout
, "thread-name",
5658 target_pid_to_str (t
->ptid
));
5659 ui_out_field_fmt (uiout
, "thread-id", "] #%d", t
->num
);
5660 ui_out_text (uiout
, " stopped");
5664 ui_out_text (uiout
, "\nProgram received signal ");
5665 annotate_signal_name ();
5666 if (ui_out_is_mi_like_p (uiout
))
5668 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
5669 ui_out_field_string (uiout
, "signal-name",
5670 target_signal_to_name (siggnal
));
5671 annotate_signal_name_end ();
5672 ui_out_text (uiout
, ", ");
5673 annotate_signal_string ();
5674 ui_out_field_string (uiout
, "signal-meaning",
5675 target_signal_to_string (siggnal
));
5676 annotate_signal_string_end ();
5678 ui_out_text (uiout
, ".\n");
5681 /* Reverse execution: target ran out of history info, print why the inferior
5685 print_no_history_reason (void)
5687 ui_out_text (uiout
, "\nNo more reverse-execution history.\n");
5690 /* Here to return control to GDB when the inferior stops for real.
5691 Print appropriate messages, remove breakpoints, give terminal our modes.
5693 STOP_PRINT_FRAME nonzero means print the executing frame
5694 (pc, function, args, file, line number and line text).
5695 BREAKPOINTS_FAILED nonzero means stop was due to error
5696 attempting to insert breakpoints. */
5701 struct target_waitstatus last
;
5703 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
5705 get_last_target_status (&last_ptid
, &last
);
5707 /* If an exception is thrown from this point on, make sure to
5708 propagate GDB's knowledge of the executing state to the
5709 frontend/user running state. A QUIT is an easy exception to see
5710 here, so do this before any filtered output. */
5712 make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
5713 else if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
5714 && last
.kind
!= TARGET_WAITKIND_EXITED
)
5715 make_cleanup (finish_thread_state_cleanup
, &inferior_ptid
);
5717 /* In non-stop mode, we don't want GDB to switch threads behind the
5718 user's back, to avoid races where the user is typing a command to
5719 apply to thread x, but GDB switches to thread y before the user
5720 finishes entering the command. */
5722 /* As with the notification of thread events, we want to delay
5723 notifying the user that we've switched thread context until
5724 the inferior actually stops.
5726 There's no point in saying anything if the inferior has exited.
5727 Note that SIGNALLED here means "exited with a signal", not
5728 "received a signal". */
5730 && !ptid_equal (previous_inferior_ptid
, inferior_ptid
)
5731 && target_has_execution
5732 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
5733 && last
.kind
!= TARGET_WAITKIND_EXITED
)
5735 target_terminal_ours_for_output ();
5736 printf_filtered (_("[Switching to %s]\n"),
5737 target_pid_to_str (inferior_ptid
));
5738 annotate_thread_changed ();
5739 previous_inferior_ptid
= inferior_ptid
;
5742 if (!breakpoints_always_inserted_mode () && target_has_execution
)
5744 if (remove_breakpoints ())
5746 target_terminal_ours_for_output ();
5747 printf_filtered (_("Cannot remove breakpoints because "
5748 "program is no longer writable.\nFurther "
5749 "execution is probably impossible.\n"));
5753 /* If an auto-display called a function and that got a signal,
5754 delete that auto-display to avoid an infinite recursion. */
5756 if (stopped_by_random_signal
)
5757 disable_current_display ();
5759 /* Don't print a message if in the middle of doing a "step n"
5760 operation for n > 1 */
5761 if (target_has_execution
5762 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
5763 && last
.kind
!= TARGET_WAITKIND_EXITED
5764 && inferior_thread ()->step_multi
5765 && inferior_thread ()->control
.stop_step
)
5768 target_terminal_ours ();
5770 /* Set the current source location. This will also happen if we
5771 display the frame below, but the current SAL will be incorrect
5772 during a user hook-stop function. */
5773 if (has_stack_frames () && !stop_stack_dummy
)
5774 set_current_sal_from_frame (get_current_frame (), 1);
5776 /* Let the user/frontend see the threads as stopped. */
5777 do_cleanups (old_chain
);
5779 /* Look up the hook_stop and run it (CLI internally handles problem
5780 of stop_command's pre-hook not existing). */
5782 catch_errors (hook_stop_stub
, stop_command
,
5783 "Error while running hook_stop:\n", RETURN_MASK_ALL
);
5785 if (!has_stack_frames ())
5788 if (last
.kind
== TARGET_WAITKIND_SIGNALLED
5789 || last
.kind
== TARGET_WAITKIND_EXITED
)
5792 /* Select innermost stack frame - i.e., current frame is frame 0,
5793 and current location is based on that.
5794 Don't do this on return from a stack dummy routine,
5795 or if the program has exited. */
5797 if (!stop_stack_dummy
)
5799 select_frame (get_current_frame ());
5801 /* Print current location without a level number, if
5802 we have changed functions or hit a breakpoint.
5803 Print source line if we have one.
5804 bpstat_print() contains the logic deciding in detail
5805 what to print, based on the event(s) that just occurred. */
5807 /* If --batch-silent is enabled then there's no need to print the current
5808 source location, and to try risks causing an error message about
5809 missing source files. */
5810 if (stop_print_frame
&& !batch_silent
)
5814 int do_frame_printing
= 1;
5815 struct thread_info
*tp
= inferior_thread ();
5817 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
);
5821 /* If we had hit a shared library event breakpoint,
5822 bpstat_print would print out this message. If we hit
5823 an OS-level shared library event, do the same
5825 if (last
.kind
== TARGET_WAITKIND_LOADED
)
5827 printf_filtered (_("Stopped due to shared library event\n"));
5828 source_flag
= SRC_LINE
; /* something bogus */
5829 do_frame_printing
= 0;
5833 /* FIXME: cagney/2002-12-01: Given that a frame ID does
5834 (or should) carry around the function and does (or
5835 should) use that when doing a frame comparison. */
5836 if (tp
->control
.stop_step
5837 && frame_id_eq (tp
->control
.step_frame_id
,
5838 get_frame_id (get_current_frame ()))
5839 && step_start_function
== find_pc_function (stop_pc
))
5840 source_flag
= SRC_LINE
; /* Finished step, just
5841 print source line. */
5843 source_flag
= SRC_AND_LOC
; /* Print location and
5846 case PRINT_SRC_AND_LOC
:
5847 source_flag
= SRC_AND_LOC
; /* Print location and
5850 case PRINT_SRC_ONLY
:
5851 source_flag
= SRC_LINE
;
5854 source_flag
= SRC_LINE
; /* something bogus */
5855 do_frame_printing
= 0;
5858 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
5861 /* The behavior of this routine with respect to the source
5863 SRC_LINE: Print only source line
5864 LOCATION: Print only location
5865 SRC_AND_LOC: Print location and source line. */
5866 if (do_frame_printing
)
5867 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
);
5869 /* Display the auto-display expressions. */
5874 /* Save the function value return registers, if we care.
5875 We might be about to restore their previous contents. */
5876 if (inferior_thread ()->control
.proceed_to_finish
5877 && execution_direction
!= EXEC_REVERSE
)
5879 /* This should not be necessary. */
5881 regcache_xfree (stop_registers
);
5883 /* NB: The copy goes through to the target picking up the value of
5884 all the registers. */
5885 stop_registers
= regcache_dup (get_current_regcache ());
5888 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
5890 /* Pop the empty frame that contains the stack dummy.
5891 This also restores inferior state prior to the call
5892 (struct infcall_suspend_state). */
5893 struct frame_info
*frame
= get_current_frame ();
5895 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
5897 /* frame_pop() calls reinit_frame_cache as the last thing it
5898 does which means there's currently no selected frame. We
5899 don't need to re-establish a selected frame if the dummy call
5900 returns normally, that will be done by
5901 restore_infcall_control_state. However, we do have to handle
5902 the case where the dummy call is returning after being
5903 stopped (e.g. the dummy call previously hit a breakpoint).
5904 We can't know which case we have so just always re-establish
5905 a selected frame here. */
5906 select_frame (get_current_frame ());
5910 annotate_stopped ();
5912 /* Suppress the stop observer if we're in the middle of:
5914 - a step n (n > 1), as there still more steps to be done.
5916 - a "finish" command, as the observer will be called in
5917 finish_command_continuation, so it can include the inferior
5918 function's return value.
5920 - calling an inferior function, as we pretend we inferior didn't
5921 run at all. The return value of the call is handled by the
5922 expression evaluator, through call_function_by_hand. */
5924 if (!target_has_execution
5925 || last
.kind
== TARGET_WAITKIND_SIGNALLED
5926 || last
.kind
== TARGET_WAITKIND_EXITED
5927 || (!inferior_thread ()->step_multi
5928 && !(inferior_thread ()->control
.stop_bpstat
5929 && inferior_thread ()->control
.proceed_to_finish
)
5930 && !inferior_thread ()->control
.in_infcall
))
5932 if (!ptid_equal (inferior_ptid
, null_ptid
))
5933 observer_notify_normal_stop (inferior_thread ()->control
.stop_bpstat
,
5936 observer_notify_normal_stop (NULL
, stop_print_frame
);
5939 if (target_has_execution
)
5941 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
5942 && last
.kind
!= TARGET_WAITKIND_EXITED
)
5943 /* Delete the breakpoint we stopped at, if it wants to be deleted.
5944 Delete any breakpoint that is to be deleted at the next stop. */
5945 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
5948 /* Try to get rid of automatically added inferiors that are no
5949 longer needed. Keeping those around slows down things linearly.
5950 Note that this never removes the current inferior. */
5955 hook_stop_stub (void *cmd
)
5957 execute_cmd_pre_hook ((struct cmd_list_element
*) cmd
);
5962 signal_stop_state (int signo
)
5964 return signal_stop
[signo
];
5968 signal_print_state (int signo
)
5970 return signal_print
[signo
];
5974 signal_pass_state (int signo
)
5976 return signal_program
[signo
];
5980 signal_cache_update (int signo
)
5984 for (signo
= 0; signo
< (int) TARGET_SIGNAL_LAST
; signo
++)
5985 signal_cache_update (signo
);
5990 signal_pass
[signo
] = (signal_stop
[signo
] == 0
5991 && signal_print
[signo
] == 0
5992 && signal_program
[signo
] == 1);
5996 signal_stop_update (int signo
, int state
)
5998 int ret
= signal_stop
[signo
];
6000 signal_stop
[signo
] = state
;
6001 signal_cache_update (signo
);
6006 signal_print_update (int signo
, int state
)
6008 int ret
= signal_print
[signo
];
6010 signal_print
[signo
] = state
;
6011 signal_cache_update (signo
);
6016 signal_pass_update (int signo
, int state
)
6018 int ret
= signal_program
[signo
];
6020 signal_program
[signo
] = state
;
6021 signal_cache_update (signo
);
6026 sig_print_header (void)
6028 printf_filtered (_("Signal Stop\tPrint\tPass "
6029 "to program\tDescription\n"));
6033 sig_print_info (enum target_signal oursig
)
6035 const char *name
= target_signal_to_name (oursig
);
6036 int name_padding
= 13 - strlen (name
);
6038 if (name_padding
<= 0)
6041 printf_filtered ("%s", name
);
6042 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
6043 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
6044 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
6045 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
6046 printf_filtered ("%s\n", target_signal_to_string (oursig
));
6049 /* Specify how various signals in the inferior should be handled. */
6052 handle_command (char *args
, int from_tty
)
6055 int digits
, wordlen
;
6056 int sigfirst
, signum
, siglast
;
6057 enum target_signal oursig
;
6060 unsigned char *sigs
;
6061 struct cleanup
*old_chain
;
6065 error_no_arg (_("signal to handle"));
6068 /* Allocate and zero an array of flags for which signals to handle. */
6070 nsigs
= (int) TARGET_SIGNAL_LAST
;
6071 sigs
= (unsigned char *) alloca (nsigs
);
6072 memset (sigs
, 0, nsigs
);
6074 /* Break the command line up into args. */
6076 argv
= gdb_buildargv (args
);
6077 old_chain
= make_cleanup_freeargv (argv
);
6079 /* Walk through the args, looking for signal oursigs, signal names, and
6080 actions. Signal numbers and signal names may be interspersed with
6081 actions, with the actions being performed for all signals cumulatively
6082 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6084 while (*argv
!= NULL
)
6086 wordlen
= strlen (*argv
);
6087 for (digits
= 0; isdigit ((*argv
)[digits
]); digits
++)
6091 sigfirst
= siglast
= -1;
6093 if (wordlen
>= 1 && !strncmp (*argv
, "all", wordlen
))
6095 /* Apply action to all signals except those used by the
6096 debugger. Silently skip those. */
6099 siglast
= nsigs
- 1;
6101 else if (wordlen
>= 1 && !strncmp (*argv
, "stop", wordlen
))
6103 SET_SIGS (nsigs
, sigs
, signal_stop
);
6104 SET_SIGS (nsigs
, sigs
, signal_print
);
6106 else if (wordlen
>= 1 && !strncmp (*argv
, "ignore", wordlen
))
6108 UNSET_SIGS (nsigs
, sigs
, signal_program
);
6110 else if (wordlen
>= 2 && !strncmp (*argv
, "print", wordlen
))
6112 SET_SIGS (nsigs
, sigs
, signal_print
);
6114 else if (wordlen
>= 2 && !strncmp (*argv
, "pass", wordlen
))
6116 SET_SIGS (nsigs
, sigs
, signal_program
);
6118 else if (wordlen
>= 3 && !strncmp (*argv
, "nostop", wordlen
))
6120 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
6122 else if (wordlen
>= 3 && !strncmp (*argv
, "noignore", wordlen
))
6124 SET_SIGS (nsigs
, sigs
, signal_program
);
6126 else if (wordlen
>= 4 && !strncmp (*argv
, "noprint", wordlen
))
6128 UNSET_SIGS (nsigs
, sigs
, signal_print
);
6129 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
6131 else if (wordlen
>= 4 && !strncmp (*argv
, "nopass", wordlen
))
6133 UNSET_SIGS (nsigs
, sigs
, signal_program
);
6135 else if (digits
> 0)
6137 /* It is numeric. The numeric signal refers to our own
6138 internal signal numbering from target.h, not to host/target
6139 signal number. This is a feature; users really should be
6140 using symbolic names anyway, and the common ones like
6141 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6143 sigfirst
= siglast
= (int)
6144 target_signal_from_command (atoi (*argv
));
6145 if ((*argv
)[digits
] == '-')
6148 target_signal_from_command (atoi ((*argv
) + digits
+ 1));
6150 if (sigfirst
> siglast
)
6152 /* Bet he didn't figure we'd think of this case... */
6160 oursig
= target_signal_from_name (*argv
);
6161 if (oursig
!= TARGET_SIGNAL_UNKNOWN
)
6163 sigfirst
= siglast
= (int) oursig
;
6167 /* Not a number and not a recognized flag word => complain. */
6168 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv
);
6172 /* If any signal numbers or symbol names were found, set flags for
6173 which signals to apply actions to. */
6175 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
6177 switch ((enum target_signal
) signum
)
6179 case TARGET_SIGNAL_TRAP
:
6180 case TARGET_SIGNAL_INT
:
6181 if (!allsigs
&& !sigs
[signum
])
6183 if (query (_("%s is used by the debugger.\n\
6184 Are you sure you want to change it? "),
6185 target_signal_to_name ((enum target_signal
) signum
)))
6191 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6192 gdb_flush (gdb_stdout
);
6196 case TARGET_SIGNAL_0
:
6197 case TARGET_SIGNAL_DEFAULT
:
6198 case TARGET_SIGNAL_UNKNOWN
:
6199 /* Make sure that "all" doesn't print these. */
6210 for (signum
= 0; signum
< nsigs
; signum
++)
6213 signal_cache_update (-1);
6214 target_pass_signals ((int) TARGET_SIGNAL_LAST
, signal_pass
);
6218 /* Show the results. */
6219 sig_print_header ();
6220 for (; signum
< nsigs
; signum
++)
6222 sig_print_info (signum
);
6228 do_cleanups (old_chain
);
6232 xdb_handle_command (char *args
, int from_tty
)
6235 struct cleanup
*old_chain
;
6238 error_no_arg (_("xdb command"));
6240 /* Break the command line up into args. */
6242 argv
= gdb_buildargv (args
);
6243 old_chain
= make_cleanup_freeargv (argv
);
6244 if (argv
[1] != (char *) NULL
)
6249 bufLen
= strlen (argv
[0]) + 20;
6250 argBuf
= (char *) xmalloc (bufLen
);
6254 enum target_signal oursig
;
6256 oursig
= target_signal_from_name (argv
[0]);
6257 memset (argBuf
, 0, bufLen
);
6258 if (strcmp (argv
[1], "Q") == 0)
6259 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
6262 if (strcmp (argv
[1], "s") == 0)
6264 if (!signal_stop
[oursig
])
6265 sprintf (argBuf
, "%s %s", argv
[0], "stop");
6267 sprintf (argBuf
, "%s %s", argv
[0], "nostop");
6269 else if (strcmp (argv
[1], "i") == 0)
6271 if (!signal_program
[oursig
])
6272 sprintf (argBuf
, "%s %s", argv
[0], "pass");
6274 sprintf (argBuf
, "%s %s", argv
[0], "nopass");
6276 else if (strcmp (argv
[1], "r") == 0)
6278 if (!signal_print
[oursig
])
6279 sprintf (argBuf
, "%s %s", argv
[0], "print");
6281 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
6287 handle_command (argBuf
, from_tty
);
6289 printf_filtered (_("Invalid signal handling flag.\n"));
6294 do_cleanups (old_chain
);
6297 /* Print current contents of the tables set by the handle command.
6298 It is possible we should just be printing signals actually used
6299 by the current target (but for things to work right when switching
6300 targets, all signals should be in the signal tables). */
6303 signals_info (char *signum_exp
, int from_tty
)
6305 enum target_signal oursig
;
6307 sig_print_header ();
6311 /* First see if this is a symbol name. */
6312 oursig
= target_signal_from_name (signum_exp
);
6313 if (oursig
== TARGET_SIGNAL_UNKNOWN
)
6315 /* No, try numeric. */
6317 target_signal_from_command (parse_and_eval_long (signum_exp
));
6319 sig_print_info (oursig
);
6323 printf_filtered ("\n");
6324 /* These ugly casts brought to you by the native VAX compiler. */
6325 for (oursig
= TARGET_SIGNAL_FIRST
;
6326 (int) oursig
< (int) TARGET_SIGNAL_LAST
;
6327 oursig
= (enum target_signal
) ((int) oursig
+ 1))
6331 if (oursig
!= TARGET_SIGNAL_UNKNOWN
6332 && oursig
!= TARGET_SIGNAL_DEFAULT
&& oursig
!= TARGET_SIGNAL_0
)
6333 sig_print_info (oursig
);
6336 printf_filtered (_("\nUse the \"handle\" command "
6337 "to change these tables.\n"));
6340 /* The $_siginfo convenience variable is a bit special. We don't know
6341 for sure the type of the value until we actually have a chance to
6342 fetch the data. The type can change depending on gdbarch, so it is
6343 also dependent on which thread you have selected.
6345 1. making $_siginfo be an internalvar that creates a new value on
6348 2. making the value of $_siginfo be an lval_computed value. */
6350 /* This function implements the lval_computed support for reading a
6354 siginfo_value_read (struct value
*v
)
6356 LONGEST transferred
;
6359 target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
,
6361 value_contents_all_raw (v
),
6363 TYPE_LENGTH (value_type (v
)));
6365 if (transferred
!= TYPE_LENGTH (value_type (v
)))
6366 error (_("Unable to read siginfo"));
6369 /* This function implements the lval_computed support for writing a
6373 siginfo_value_write (struct value
*v
, struct value
*fromval
)
6375 LONGEST transferred
;
6377 transferred
= target_write (¤t_target
,
6378 TARGET_OBJECT_SIGNAL_INFO
,
6380 value_contents_all_raw (fromval
),
6382 TYPE_LENGTH (value_type (fromval
)));
6384 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
6385 error (_("Unable to write siginfo"));
6388 static struct lval_funcs siginfo_value_funcs
=
6394 /* Return a new value with the correct type for the siginfo object of
6395 the current thread using architecture GDBARCH. Return a void value
6396 if there's no object available. */
6398 static struct value
*
6399 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
)
6401 if (target_has_stack
6402 && !ptid_equal (inferior_ptid
, null_ptid
)
6403 && gdbarch_get_siginfo_type_p (gdbarch
))
6405 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
6407 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
6410 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
6414 /* infcall_suspend_state contains state about the program itself like its
6415 registers and any signal it received when it last stopped.
6416 This state must be restored regardless of how the inferior function call
6417 ends (either successfully, or after it hits a breakpoint or signal)
6418 if the program is to properly continue where it left off. */
6420 struct infcall_suspend_state
6422 struct thread_suspend_state thread_suspend
;
6423 struct inferior_suspend_state inferior_suspend
;
6427 struct regcache
*registers
;
6429 /* Format of SIGINFO_DATA or NULL if it is not present. */
6430 struct gdbarch
*siginfo_gdbarch
;
6432 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6433 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6434 content would be invalid. */
6435 gdb_byte
*siginfo_data
;
6438 struct infcall_suspend_state
*
6439 save_infcall_suspend_state (void)
6441 struct infcall_suspend_state
*inf_state
;
6442 struct thread_info
*tp
= inferior_thread ();
6443 struct inferior
*inf
= current_inferior ();
6444 struct regcache
*regcache
= get_current_regcache ();
6445 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
6446 gdb_byte
*siginfo_data
= NULL
;
6448 if (gdbarch_get_siginfo_type_p (gdbarch
))
6450 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
6451 size_t len
= TYPE_LENGTH (type
);
6452 struct cleanup
*back_to
;
6454 siginfo_data
= xmalloc (len
);
6455 back_to
= make_cleanup (xfree
, siginfo_data
);
6457 if (target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
6458 siginfo_data
, 0, len
) == len
)
6459 discard_cleanups (back_to
);
6462 /* Errors ignored. */
6463 do_cleanups (back_to
);
6464 siginfo_data
= NULL
;
6468 inf_state
= XZALLOC (struct infcall_suspend_state
);
6472 inf_state
->siginfo_gdbarch
= gdbarch
;
6473 inf_state
->siginfo_data
= siginfo_data
;
6476 inf_state
->thread_suspend
= tp
->suspend
;
6477 inf_state
->inferior_suspend
= inf
->suspend
;
6479 /* run_inferior_call will not use the signal due to its `proceed' call with
6480 TARGET_SIGNAL_0 anyway. */
6481 tp
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
6483 inf_state
->stop_pc
= stop_pc
;
6485 inf_state
->registers
= regcache_dup (regcache
);
6490 /* Restore inferior session state to INF_STATE. */
6493 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
6495 struct thread_info
*tp
= inferior_thread ();
6496 struct inferior
*inf
= current_inferior ();
6497 struct regcache
*regcache
= get_current_regcache ();
6498 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
6500 tp
->suspend
= inf_state
->thread_suspend
;
6501 inf
->suspend
= inf_state
->inferior_suspend
;
6503 stop_pc
= inf_state
->stop_pc
;
6505 if (inf_state
->siginfo_gdbarch
== gdbarch
)
6507 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
6508 size_t len
= TYPE_LENGTH (type
);
6510 /* Errors ignored. */
6511 target_write (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
, NULL
,
6512 inf_state
->siginfo_data
, 0, len
);
6515 /* The inferior can be gone if the user types "print exit(0)"
6516 (and perhaps other times). */
6517 if (target_has_execution
)
6518 /* NB: The register write goes through to the target. */
6519 regcache_cpy (regcache
, inf_state
->registers
);
6521 discard_infcall_suspend_state (inf_state
);
6525 do_restore_infcall_suspend_state_cleanup (void *state
)
6527 restore_infcall_suspend_state (state
);
6531 make_cleanup_restore_infcall_suspend_state
6532 (struct infcall_suspend_state
*inf_state
)
6534 return make_cleanup (do_restore_infcall_suspend_state_cleanup
, inf_state
);
6538 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
6540 regcache_xfree (inf_state
->registers
);
6541 xfree (inf_state
->siginfo_data
);
6546 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
6548 return inf_state
->registers
;
6551 /* infcall_control_state contains state regarding gdb's control of the
6552 inferior itself like stepping control. It also contains session state like
6553 the user's currently selected frame. */
6555 struct infcall_control_state
6557 struct thread_control_state thread_control
;
6558 struct inferior_control_state inferior_control
;
6561 enum stop_stack_kind stop_stack_dummy
;
6562 int stopped_by_random_signal
;
6563 int stop_after_trap
;
6565 /* ID if the selected frame when the inferior function call was made. */
6566 struct frame_id selected_frame_id
;
6569 /* Save all of the information associated with the inferior<==>gdb
6572 struct infcall_control_state
*
6573 save_infcall_control_state (void)
6575 struct infcall_control_state
*inf_status
= xmalloc (sizeof (*inf_status
));
6576 struct thread_info
*tp
= inferior_thread ();
6577 struct inferior
*inf
= current_inferior ();
6579 inf_status
->thread_control
= tp
->control
;
6580 inf_status
->inferior_control
= inf
->control
;
6582 tp
->control
.step_resume_breakpoint
= NULL
;
6583 tp
->control
.exception_resume_breakpoint
= NULL
;
6585 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6586 chain. If caller's caller is walking the chain, they'll be happier if we
6587 hand them back the original chain when restore_infcall_control_state is
6589 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
6592 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
6593 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
6594 inf_status
->stop_after_trap
= stop_after_trap
;
6596 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
6602 restore_selected_frame (void *args
)
6604 struct frame_id
*fid
= (struct frame_id
*) args
;
6605 struct frame_info
*frame
;
6607 frame
= frame_find_by_id (*fid
);
6609 /* If inf_status->selected_frame_id is NULL, there was no previously
6613 warning (_("Unable to restore previously selected frame."));
6617 select_frame (frame
);
6622 /* Restore inferior session state to INF_STATUS. */
6625 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
6627 struct thread_info
*tp
= inferior_thread ();
6628 struct inferior
*inf
= current_inferior ();
6630 if (tp
->control
.step_resume_breakpoint
)
6631 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
6633 if (tp
->control
.exception_resume_breakpoint
)
6634 tp
->control
.exception_resume_breakpoint
->disposition
6635 = disp_del_at_next_stop
;
6637 /* Handle the bpstat_copy of the chain. */
6638 bpstat_clear (&tp
->control
.stop_bpstat
);
6640 tp
->control
= inf_status
->thread_control
;
6641 inf
->control
= inf_status
->inferior_control
;
6644 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
6645 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
6646 stop_after_trap
= inf_status
->stop_after_trap
;
6648 if (target_has_stack
)
6650 /* The point of catch_errors is that if the stack is clobbered,
6651 walking the stack might encounter a garbage pointer and
6652 error() trying to dereference it. */
6654 (restore_selected_frame
, &inf_status
->selected_frame_id
,
6655 "Unable to restore previously selected frame:\n",
6656 RETURN_MASK_ERROR
) == 0)
6657 /* Error in restoring the selected frame. Select the innermost
6659 select_frame (get_current_frame ());
6666 do_restore_infcall_control_state_cleanup (void *sts
)
6668 restore_infcall_control_state (sts
);
6672 make_cleanup_restore_infcall_control_state
6673 (struct infcall_control_state
*inf_status
)
6675 return make_cleanup (do_restore_infcall_control_state_cleanup
, inf_status
);
6679 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
6681 if (inf_status
->thread_control
.step_resume_breakpoint
)
6682 inf_status
->thread_control
.step_resume_breakpoint
->disposition
6683 = disp_del_at_next_stop
;
6685 if (inf_status
->thread_control
.exception_resume_breakpoint
)
6686 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
6687 = disp_del_at_next_stop
;
6689 /* See save_infcall_control_state for info on stop_bpstat. */
6690 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
6696 inferior_has_forked (ptid_t pid
, ptid_t
*child_pid
)
6698 struct target_waitstatus last
;
6701 get_last_target_status (&last_ptid
, &last
);
6703 if (last
.kind
!= TARGET_WAITKIND_FORKED
)
6706 if (!ptid_equal (last_ptid
, pid
))
6709 *child_pid
= last
.value
.related_pid
;
6714 inferior_has_vforked (ptid_t pid
, ptid_t
*child_pid
)
6716 struct target_waitstatus last
;
6719 get_last_target_status (&last_ptid
, &last
);
6721 if (last
.kind
!= TARGET_WAITKIND_VFORKED
)
6724 if (!ptid_equal (last_ptid
, pid
))
6727 *child_pid
= last
.value
.related_pid
;
6732 inferior_has_execd (ptid_t pid
, char **execd_pathname
)
6734 struct target_waitstatus last
;
6737 get_last_target_status (&last_ptid
, &last
);
6739 if (last
.kind
!= TARGET_WAITKIND_EXECD
)
6742 if (!ptid_equal (last_ptid
, pid
))
6745 *execd_pathname
= xstrdup (last
.value
.execd_pathname
);
6750 inferior_has_called_syscall (ptid_t pid
, int *syscall_number
)
6752 struct target_waitstatus last
;
6755 get_last_target_status (&last_ptid
, &last
);
6757 if (last
.kind
!= TARGET_WAITKIND_SYSCALL_ENTRY
&&
6758 last
.kind
!= TARGET_WAITKIND_SYSCALL_RETURN
)
6761 if (!ptid_equal (last_ptid
, pid
))
6764 *syscall_number
= last
.value
.syscall_number
;
6768 /* Oft used ptids */
6770 ptid_t minus_one_ptid
;
6772 /* Create a ptid given the necessary PID, LWP, and TID components. */
6775 ptid_build (int pid
, long lwp
, long tid
)
6785 /* Create a ptid from just a pid. */
6788 pid_to_ptid (int pid
)
6790 return ptid_build (pid
, 0, 0);
6793 /* Fetch the pid (process id) component from a ptid. */
6796 ptid_get_pid (ptid_t ptid
)
6801 /* Fetch the lwp (lightweight process) component from a ptid. */
6804 ptid_get_lwp (ptid_t ptid
)
6809 /* Fetch the tid (thread id) component from a ptid. */
6812 ptid_get_tid (ptid_t ptid
)
6817 /* ptid_equal() is used to test equality of two ptids. */
6820 ptid_equal (ptid_t ptid1
, ptid_t ptid2
)
6822 return (ptid1
.pid
== ptid2
.pid
&& ptid1
.lwp
== ptid2
.lwp
6823 && ptid1
.tid
== ptid2
.tid
);
6826 /* Returns true if PTID represents a process. */
6829 ptid_is_pid (ptid_t ptid
)
6831 if (ptid_equal (minus_one_ptid
, ptid
))
6833 if (ptid_equal (null_ptid
, ptid
))
6836 return (ptid_get_lwp (ptid
) == 0 && ptid_get_tid (ptid
) == 0);
6840 ptid_match (ptid_t ptid
, ptid_t filter
)
6842 if (ptid_equal (filter
, minus_one_ptid
))
6844 if (ptid_is_pid (filter
)
6845 && ptid_get_pid (ptid
) == ptid_get_pid (filter
))
6847 else if (ptid_equal (ptid
, filter
))
6853 /* restore_inferior_ptid() will be used by the cleanup machinery
6854 to restore the inferior_ptid value saved in a call to
6855 save_inferior_ptid(). */
6858 restore_inferior_ptid (void *arg
)
6860 ptid_t
*saved_ptid_ptr
= arg
;
6862 inferior_ptid
= *saved_ptid_ptr
;
6866 /* Save the value of inferior_ptid so that it may be restored by a
6867 later call to do_cleanups(). Returns the struct cleanup pointer
6868 needed for later doing the cleanup. */
6871 save_inferior_ptid (void)
6873 ptid_t
*saved_ptid_ptr
;
6875 saved_ptid_ptr
= xmalloc (sizeof (ptid_t
));
6876 *saved_ptid_ptr
= inferior_ptid
;
6877 return make_cleanup (restore_inferior_ptid
, saved_ptid_ptr
);
6881 /* User interface for reverse debugging:
6882 Set exec-direction / show exec-direction commands
6883 (returns error unless target implements to_set_exec_direction method). */
6885 int execution_direction
= EXEC_FORWARD
;
6886 static const char exec_forward
[] = "forward";
6887 static const char exec_reverse
[] = "reverse";
6888 static const char *exec_direction
= exec_forward
;
6889 static const char *exec_direction_names
[] = {
6896 set_exec_direction_func (char *args
, int from_tty
,
6897 struct cmd_list_element
*cmd
)
6899 if (target_can_execute_reverse
)
6901 if (!strcmp (exec_direction
, exec_forward
))
6902 execution_direction
= EXEC_FORWARD
;
6903 else if (!strcmp (exec_direction
, exec_reverse
))
6904 execution_direction
= EXEC_REVERSE
;
6908 exec_direction
= exec_forward
;
6909 error (_("Target does not support this operation."));
6914 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
6915 struct cmd_list_element
*cmd
, const char *value
)
6917 switch (execution_direction
) {
6919 fprintf_filtered (out
, _("Forward.\n"));
6922 fprintf_filtered (out
, _("Reverse.\n"));
6925 internal_error (__FILE__
, __LINE__
,
6926 _("bogus execution_direction value: %d"),
6927 (int) execution_direction
);
6931 /* User interface for non-stop mode. */
6936 set_non_stop (char *args
, int from_tty
,
6937 struct cmd_list_element
*c
)
6939 if (target_has_execution
)
6941 non_stop_1
= non_stop
;
6942 error (_("Cannot change this setting while the inferior is running."));
6945 non_stop
= non_stop_1
;
6949 show_non_stop (struct ui_file
*file
, int from_tty
,
6950 struct cmd_list_element
*c
, const char *value
)
6952 fprintf_filtered (file
,
6953 _("Controlling the inferior in non-stop mode is %s.\n"),
6958 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
6959 struct cmd_list_element
*c
, const char *value
)
6961 fprintf_filtered (file
, _("Resuming the execution of threads "
6962 "of all processes is %s.\n"), value
);
6966 _initialize_infrun (void)
6971 add_info ("signals", signals_info
, _("\
6972 What debugger does when program gets various signals.\n\
6973 Specify a signal as argument to print info on that signal only."));
6974 add_info_alias ("handle", "signals", 0);
6976 add_com ("handle", class_run
, handle_command
, _("\
6977 Specify how to handle a signal.\n\
6978 Args are signals and actions to apply to those signals.\n\
6979 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
6980 from 1-15 are allowed for compatibility with old versions of GDB.\n\
6981 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
6982 The special arg \"all\" is recognized to mean all signals except those\n\
6983 used by the debugger, typically SIGTRAP and SIGINT.\n\
6984 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
6985 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
6986 Stop means reenter debugger if this signal happens (implies print).\n\
6987 Print means print a message if this signal happens.\n\
6988 Pass means let program see this signal; otherwise program doesn't know.\n\
6989 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
6990 Pass and Stop may be combined."));
6993 add_com ("lz", class_info
, signals_info
, _("\
6994 What debugger does when program gets various signals.\n\
6995 Specify a signal as argument to print info on that signal only."));
6996 add_com ("z", class_run
, xdb_handle_command
, _("\
6997 Specify how to handle a signal.\n\
6998 Args are signals and actions to apply to those signals.\n\
6999 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7000 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7001 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7002 The special arg \"all\" is recognized to mean all signals except those\n\
7003 used by the debugger, typically SIGTRAP and SIGINT.\n\
7004 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7005 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7006 nopass), \"Q\" (noprint)\n\
7007 Stop means reenter debugger if this signal happens (implies print).\n\
7008 Print means print a message if this signal happens.\n\
7009 Pass means let program see this signal; otherwise program doesn't know.\n\
7010 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7011 Pass and Stop may be combined."));
7015 stop_command
= add_cmd ("stop", class_obscure
,
7016 not_just_help_class_command
, _("\
7017 There is no `stop' command, but you can set a hook on `stop'.\n\
7018 This allows you to set a list of commands to be run each time execution\n\
7019 of the program stops."), &cmdlist
);
7021 add_setshow_zinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
7022 Set inferior debugging."), _("\
7023 Show inferior debugging."), _("\
7024 When non-zero, inferior specific debugging is enabled."),
7027 &setdebuglist
, &showdebuglist
);
7029 add_setshow_boolean_cmd ("displaced", class_maintenance
,
7030 &debug_displaced
, _("\
7031 Set displaced stepping debugging."), _("\
7032 Show displaced stepping debugging."), _("\
7033 When non-zero, displaced stepping specific debugging is enabled."),
7035 show_debug_displaced
,
7036 &setdebuglist
, &showdebuglist
);
7038 add_setshow_boolean_cmd ("non-stop", no_class
,
7040 Set whether gdb controls the inferior in non-stop mode."), _("\
7041 Show whether gdb controls the inferior in non-stop mode."), _("\
7042 When debugging a multi-threaded program and this setting is\n\
7043 off (the default, also called all-stop mode), when one thread stops\n\
7044 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7045 all other threads in the program while you interact with the thread of\n\
7046 interest. When you continue or step a thread, you can allow the other\n\
7047 threads to run, or have them remain stopped, but while you inspect any\n\
7048 thread's state, all threads stop.\n\
7050 In non-stop mode, when one thread stops, other threads can continue\n\
7051 to run freely. You'll be able to step each thread independently,\n\
7052 leave it stopped or free to run as needed."),
7058 numsigs
= (int) TARGET_SIGNAL_LAST
;
7059 signal_stop
= (unsigned char *) xmalloc (sizeof (signal_stop
[0]) * numsigs
);
7060 signal_print
= (unsigned char *)
7061 xmalloc (sizeof (signal_print
[0]) * numsigs
);
7062 signal_program
= (unsigned char *)
7063 xmalloc (sizeof (signal_program
[0]) * numsigs
);
7064 signal_pass
= (unsigned char *)
7065 xmalloc (sizeof (signal_program
[0]) * numsigs
);
7066 for (i
= 0; i
< numsigs
; i
++)
7069 signal_print
[i
] = 1;
7070 signal_program
[i
] = 1;
7073 /* Signals caused by debugger's own actions
7074 should not be given to the program afterwards. */
7075 signal_program
[TARGET_SIGNAL_TRAP
] = 0;
7076 signal_program
[TARGET_SIGNAL_INT
] = 0;
7078 /* Signals that are not errors should not normally enter the debugger. */
7079 signal_stop
[TARGET_SIGNAL_ALRM
] = 0;
7080 signal_print
[TARGET_SIGNAL_ALRM
] = 0;
7081 signal_stop
[TARGET_SIGNAL_VTALRM
] = 0;
7082 signal_print
[TARGET_SIGNAL_VTALRM
] = 0;
7083 signal_stop
[TARGET_SIGNAL_PROF
] = 0;
7084 signal_print
[TARGET_SIGNAL_PROF
] = 0;
7085 signal_stop
[TARGET_SIGNAL_CHLD
] = 0;
7086 signal_print
[TARGET_SIGNAL_CHLD
] = 0;
7087 signal_stop
[TARGET_SIGNAL_IO
] = 0;
7088 signal_print
[TARGET_SIGNAL_IO
] = 0;
7089 signal_stop
[TARGET_SIGNAL_POLL
] = 0;
7090 signal_print
[TARGET_SIGNAL_POLL
] = 0;
7091 signal_stop
[TARGET_SIGNAL_URG
] = 0;
7092 signal_print
[TARGET_SIGNAL_URG
] = 0;
7093 signal_stop
[TARGET_SIGNAL_WINCH
] = 0;
7094 signal_print
[TARGET_SIGNAL_WINCH
] = 0;
7095 signal_stop
[TARGET_SIGNAL_PRIO
] = 0;
7096 signal_print
[TARGET_SIGNAL_PRIO
] = 0;
7098 /* These signals are used internally by user-level thread
7099 implementations. (See signal(5) on Solaris.) Like the above
7100 signals, a healthy program receives and handles them as part of
7101 its normal operation. */
7102 signal_stop
[TARGET_SIGNAL_LWP
] = 0;
7103 signal_print
[TARGET_SIGNAL_LWP
] = 0;
7104 signal_stop
[TARGET_SIGNAL_WAITING
] = 0;
7105 signal_print
[TARGET_SIGNAL_WAITING
] = 0;
7106 signal_stop
[TARGET_SIGNAL_CANCEL
] = 0;
7107 signal_print
[TARGET_SIGNAL_CANCEL
] = 0;
7109 /* Update cached state. */
7110 signal_cache_update (-1);
7112 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
7113 &stop_on_solib_events
, _("\
7114 Set stopping for shared library events."), _("\
7115 Show stopping for shared library events."), _("\
7116 If nonzero, gdb will give control to the user when the dynamic linker\n\
7117 notifies gdb of shared library events. The most common event of interest\n\
7118 to the user would be loading/unloading of a new library."),
7120 show_stop_on_solib_events
,
7121 &setlist
, &showlist
);
7123 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
7124 follow_fork_mode_kind_names
,
7125 &follow_fork_mode_string
, _("\
7126 Set debugger response to a program call of fork or vfork."), _("\
7127 Show debugger response to a program call of fork or vfork."), _("\
7128 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7129 parent - the original process is debugged after a fork\n\
7130 child - the new process is debugged after a fork\n\
7131 The unfollowed process will continue to run.\n\
7132 By default, the debugger will follow the parent process."),
7134 show_follow_fork_mode_string
,
7135 &setlist
, &showlist
);
7137 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
7138 follow_exec_mode_names
,
7139 &follow_exec_mode_string
, _("\
7140 Set debugger response to a program call of exec."), _("\
7141 Show debugger response to a program call of exec."), _("\
7142 An exec call replaces the program image of a process.\n\
7144 follow-exec-mode can be:\n\
7146 new - the debugger creates a new inferior and rebinds the process\n\
7147 to this new inferior. The program the process was running before\n\
7148 the exec call can be restarted afterwards by restarting the original\n\
7151 same - the debugger keeps the process bound to the same inferior.\n\
7152 The new executable image replaces the previous executable loaded in\n\
7153 the inferior. Restarting the inferior after the exec call restarts\n\
7154 the executable the process was running after the exec call.\n\
7156 By default, the debugger will use the same inferior."),
7158 show_follow_exec_mode_string
,
7159 &setlist
, &showlist
);
7161 add_setshow_enum_cmd ("scheduler-locking", class_run
,
7162 scheduler_enums
, &scheduler_mode
, _("\
7163 Set mode for locking scheduler during execution."), _("\
7164 Show mode for locking scheduler during execution."), _("\
7165 off == no locking (threads may preempt at any time)\n\
7166 on == full locking (no thread except the current thread may run)\n\
7167 step == scheduler locked during every single-step operation.\n\
7168 In this mode, no other thread may run during a step command.\n\
7169 Other threads may run while stepping over a function call ('next')."),
7170 set_schedlock_func
, /* traps on target vector */
7171 show_scheduler_mode
,
7172 &setlist
, &showlist
);
7174 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
7175 Set mode for resuming threads of all processes."), _("\
7176 Show mode for resuming threads of all processes."), _("\
7177 When on, execution commands (such as 'continue' or 'next') resume all\n\
7178 threads of all processes. When off (which is the default), execution\n\
7179 commands only resume the threads of the current process. The set of\n\
7180 threads that are resumed is further refined by the scheduler-locking\n\
7181 mode (see help set scheduler-locking)."),
7183 show_schedule_multiple
,
7184 &setlist
, &showlist
);
7186 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
7187 Set mode of the step operation."), _("\
7188 Show mode of the step operation."), _("\
7189 When set, doing a step over a function without debug line information\n\
7190 will stop at the first instruction of that function. Otherwise, the\n\
7191 function is skipped and the step command stops at a different source line."),
7193 show_step_stop_if_no_debug
,
7194 &setlist
, &showlist
);
7196 add_setshow_enum_cmd ("displaced-stepping", class_run
,
7197 can_use_displaced_stepping_enum
,
7198 &can_use_displaced_stepping
, _("\
7199 Set debugger's willingness to use displaced stepping."), _("\
7200 Show debugger's willingness to use displaced stepping."), _("\
7201 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7202 supported by the target architecture. If off, gdb will not use displaced\n\
7203 stepping to step over breakpoints, even if such is supported by the target\n\
7204 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7205 if the target architecture supports it and non-stop mode is active, but will not\n\
7206 use it in all-stop mode (see help set non-stop)."),
7208 show_can_use_displaced_stepping
,
7209 &setlist
, &showlist
);
7211 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
7212 &exec_direction
, _("Set direction of execution.\n\
7213 Options are 'forward' or 'reverse'."),
7214 _("Show direction of execution (forward/reverse)."),
7215 _("Tells gdb whether to execute forward or backward."),
7216 set_exec_direction_func
, show_exec_direction_func
,
7217 &setlist
, &showlist
);
7219 /* Set/show detach-on-fork: user-settable mode. */
7221 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
7222 Set whether gdb will detach the child of a fork."), _("\
7223 Show whether gdb will detach the child of a fork."), _("\
7224 Tells gdb whether to detach the child of a fork."),
7225 NULL
, NULL
, &setlist
, &showlist
);
7227 /* ptid initializations */
7228 null_ptid
= ptid_build (0, 0, 0);
7229 minus_one_ptid
= ptid_build (-1, 0, 0);
7230 inferior_ptid
= null_ptid
;
7231 target_last_wait_ptid
= minus_one_ptid
;
7233 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed
);
7234 observer_attach_thread_stop_requested (infrun_thread_stop_requested
);
7235 observer_attach_thread_exit (infrun_thread_thread_exit
);
7236 observer_attach_inferior_exit (infrun_inferior_exit
);
7238 /* Explicitly create without lookup, since that tries to create a
7239 value with a void typed value, and when we get here, gdbarch
7240 isn't initialized yet. At this point, we're quite sure there
7241 isn't another convenience variable of the same name. */
7242 create_internalvar_type_lazy ("_siginfo", siginfo_make_value
);
7244 add_setshow_boolean_cmd ("observer", no_class
,
7245 &observer_mode_1
, _("\
7246 Set whether gdb controls the inferior in observer mode."), _("\
7247 Show whether gdb controls the inferior in observer mode."), _("\
7248 In observer mode, GDB can get data from the inferior, but not\n\
7249 affect its execution. Registers and memory may not be changed,\n\
7250 breakpoints may not be set, and the program cannot be interrupted\n\