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 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 "gdb_assert.h"
49 #include "mi/mi-common.h"
50 #include "event-top.h"
53 /* Prototypes for local functions */
55 static void signals_info (char *, int);
57 static void handle_command (char *, int);
59 static void sig_print_info (enum target_signal
);
61 static void sig_print_header (void);
63 static void resume_cleanups (void *);
65 static int hook_stop_stub (void *);
67 static int restore_selected_frame (void *);
69 static void build_infrun (void);
71 static int follow_fork (void);
73 static void set_schedlock_func (char *args
, int from_tty
,
74 struct cmd_list_element
*c
);
76 static int currently_stepping (struct thread_info
*tp
);
78 static int currently_stepping_or_nexting_callback (struct thread_info
*tp
,
81 static void xdb_handle_command (char *args
, int from_tty
);
83 static int prepare_to_proceed (int);
85 void _initialize_infrun (void);
87 void nullify_last_target_wait_ptid (void);
89 /* When set, stop the 'step' command if we enter a function which has
90 no line number information. The normal behavior is that we step
91 over such function. */
92 int step_stop_if_no_debug
= 0;
94 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
95 struct cmd_list_element
*c
, const char *value
)
97 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
100 /* In asynchronous mode, but simulating synchronous execution. */
102 int sync_execution
= 0;
104 /* wait_for_inferior and normal_stop use this to notify the user
105 when the inferior stopped in a different thread than it had been
108 static ptid_t previous_inferior_ptid
;
110 int debug_displaced
= 0;
112 show_debug_displaced (struct ui_file
*file
, int from_tty
,
113 struct cmd_list_element
*c
, const char *value
)
115 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
118 static int debug_infrun
= 0;
120 show_debug_infrun (struct ui_file
*file
, int from_tty
,
121 struct cmd_list_element
*c
, const char *value
)
123 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
126 /* If the program uses ELF-style shared libraries, then calls to
127 functions in shared libraries go through stubs, which live in a
128 table called the PLT (Procedure Linkage Table). The first time the
129 function is called, the stub sends control to the dynamic linker,
130 which looks up the function's real address, patches the stub so
131 that future calls will go directly to the function, and then passes
132 control to the function.
134 If we are stepping at the source level, we don't want to see any of
135 this --- we just want to skip over the stub and the dynamic linker.
136 The simple approach is to single-step until control leaves the
139 However, on some systems (e.g., Red Hat's 5.2 distribution) the
140 dynamic linker calls functions in the shared C library, so you
141 can't tell from the PC alone whether the dynamic linker is still
142 running. In this case, we use a step-resume breakpoint to get us
143 past the dynamic linker, as if we were using "next" to step over a
146 in_solib_dynsym_resolve_code() says whether we're in the dynamic
147 linker code or not. Normally, this means we single-step. However,
148 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
149 address where we can place a step-resume breakpoint to get past the
150 linker's symbol resolution function.
152 in_solib_dynsym_resolve_code() can generally be implemented in a
153 pretty portable way, by comparing the PC against the address ranges
154 of the dynamic linker's sections.
156 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
157 it depends on internal details of the dynamic linker. It's usually
158 not too hard to figure out where to put a breakpoint, but it
159 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of
160 sanity checking. If it can't figure things out, returning zero and
161 getting the (possibly confusing) stepping behavior is better than
162 signalling an error, which will obscure the change in the
165 /* This function returns TRUE if pc is the address of an instruction
166 that lies within the dynamic linker (such as the event hook, or the
169 This function must be used only when a dynamic linker event has
170 been caught, and the inferior is being stepped out of the hook, or
171 undefined results are guaranteed. */
173 #ifndef SOLIB_IN_DYNAMIC_LINKER
174 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
178 /* Convert the #defines into values. This is temporary until wfi control
179 flow is completely sorted out. */
181 #ifndef CANNOT_STEP_HW_WATCHPOINTS
182 #define CANNOT_STEP_HW_WATCHPOINTS 0
184 #undef CANNOT_STEP_HW_WATCHPOINTS
185 #define CANNOT_STEP_HW_WATCHPOINTS 1
188 /* Tables of how to react to signals; the user sets them. */
190 static unsigned char *signal_stop
;
191 static unsigned char *signal_print
;
192 static unsigned char *signal_program
;
194 #define SET_SIGS(nsigs,sigs,flags) \
196 int signum = (nsigs); \
197 while (signum-- > 0) \
198 if ((sigs)[signum]) \
199 (flags)[signum] = 1; \
202 #define UNSET_SIGS(nsigs,sigs,flags) \
204 int signum = (nsigs); \
205 while (signum-- > 0) \
206 if ((sigs)[signum]) \
207 (flags)[signum] = 0; \
210 /* Value to pass to target_resume() to cause all threads to resume */
212 #define RESUME_ALL (pid_to_ptid (-1))
214 /* Command list pointer for the "stop" placeholder. */
216 static struct cmd_list_element
*stop_command
;
218 /* Function inferior was in as of last step command. */
220 static struct symbol
*step_start_function
;
222 /* Nonzero if we want to give control to the user when we're notified
223 of shared library events by the dynamic linker. */
224 static int stop_on_solib_events
;
226 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
227 struct cmd_list_element
*c
, const char *value
)
229 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
233 /* Nonzero means expecting a trace trap
234 and should stop the inferior and return silently when it happens. */
238 /* Save register contents here when executing a "finish" command or are
239 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
240 Thus this contains the return value from the called function (assuming
241 values are returned in a register). */
243 struct regcache
*stop_registers
;
245 /* Nonzero after stop if current stack frame should be printed. */
247 static int stop_print_frame
;
249 /* This is a cached copy of the pid/waitstatus of the last event
250 returned by target_wait()/deprecated_target_wait_hook(). This
251 information is returned by get_last_target_status(). */
252 static ptid_t target_last_wait_ptid
;
253 static struct target_waitstatus target_last_waitstatus
;
255 static void context_switch (ptid_t ptid
);
257 void init_thread_stepping_state (struct thread_info
*tss
);
259 void init_infwait_state (void);
261 static const char follow_fork_mode_child
[] = "child";
262 static const char follow_fork_mode_parent
[] = "parent";
264 static const char *follow_fork_mode_kind_names
[] = {
265 follow_fork_mode_child
,
266 follow_fork_mode_parent
,
270 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
272 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
273 struct cmd_list_element
*c
, const char *value
)
275 fprintf_filtered (file
, _("\
276 Debugger response to a program call of fork or vfork is \"%s\".\n"),
281 /* Tell the target to follow the fork we're stopped at. Returns true
282 if the inferior should be resumed; false, if the target for some
283 reason decided it's best not to resume. */
288 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
289 int should_resume
= 1;
290 struct thread_info
*tp
;
292 /* Copy user stepping state to the new inferior thread. FIXME: the
293 followed fork child thread should have a copy of most of the
294 parent thread structure's run control related fields, not just these.
295 Initialized to avoid "may be used uninitialized" warnings from gcc. */
296 struct breakpoint
*step_resume_breakpoint
= NULL
;
297 CORE_ADDR step_range_start
= 0;
298 CORE_ADDR step_range_end
= 0;
299 struct frame_id step_frame_id
= { 0 };
304 struct target_waitstatus wait_status
;
306 /* Get the last target status returned by target_wait(). */
307 get_last_target_status (&wait_ptid
, &wait_status
);
309 /* If not stopped at a fork event, then there's nothing else to
311 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
312 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
315 /* Check if we switched over from WAIT_PTID, since the event was
317 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
318 && !ptid_equal (inferior_ptid
, wait_ptid
))
320 /* We did. Switch back to WAIT_PTID thread, to tell the
321 target to follow it (in either direction). We'll
322 afterwards refuse to resume, and inform the user what
324 switch_to_thread (wait_ptid
);
329 tp
= inferior_thread ();
331 /* If there were any forks/vforks that were caught and are now to be
332 followed, then do so now. */
333 switch (tp
->pending_follow
.kind
)
335 case TARGET_WAITKIND_FORKED
:
336 case TARGET_WAITKIND_VFORKED
:
338 ptid_t parent
, child
;
340 /* If the user did a next/step, etc, over a fork call,
341 preserve the stepping state in the fork child. */
342 if (follow_child
&& should_resume
)
344 step_resume_breakpoint
345 = clone_momentary_breakpoint (tp
->step_resume_breakpoint
);
346 step_range_start
= tp
->step_range_start
;
347 step_range_end
= tp
->step_range_end
;
348 step_frame_id
= tp
->step_frame_id
;
350 /* For now, delete the parent's sr breakpoint, otherwise,
351 parent/child sr breakpoints are considered duplicates,
352 and the child version will not be installed. Remove
353 this when the breakpoints module becomes aware of
354 inferiors and address spaces. */
355 delete_step_resume_breakpoint (tp
);
356 tp
->step_range_start
= 0;
357 tp
->step_range_end
= 0;
358 tp
->step_frame_id
= null_frame_id
;
361 parent
= inferior_ptid
;
362 child
= tp
->pending_follow
.value
.related_pid
;
364 /* Tell the target to do whatever is necessary to follow
365 either parent or child. */
366 if (target_follow_fork (follow_child
))
368 /* Target refused to follow, or there's some other reason
369 we shouldn't resume. */
374 /* This pending follow fork event is now handled, one way
375 or another. The previous selected thread may be gone
376 from the lists by now, but if it is still around, need
377 to clear the pending follow request. */
378 tp
= find_thread_ptid (parent
);
380 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
382 /* This makes sure we don't try to apply the "Switched
383 over from WAIT_PID" logic above. */
384 nullify_last_target_wait_ptid ();
386 /* If we followed the child, switch to it... */
389 switch_to_thread (child
);
391 /* ... and preserve the stepping state, in case the
392 user was stepping over the fork call. */
395 tp
= inferior_thread ();
396 tp
->step_resume_breakpoint
= step_resume_breakpoint
;
397 tp
->step_range_start
= step_range_start
;
398 tp
->step_range_end
= step_range_end
;
399 tp
->step_frame_id
= step_frame_id
;
403 /* If we get here, it was because we're trying to
404 resume from a fork catchpoint, but, the user
405 has switched threads away from the thread that
406 forked. In that case, the resume command
407 issued is most likely not applicable to the
408 child, so just warn, and refuse to resume. */
410 Not resuming: switched threads before following fork child.\n"));
413 /* Reset breakpoints in the child as appropriate. */
414 follow_inferior_reset_breakpoints ();
417 switch_to_thread (parent
);
421 case TARGET_WAITKIND_SPURIOUS
:
422 /* Nothing to follow. */
425 internal_error (__FILE__
, __LINE__
,
426 "Unexpected pending_follow.kind %d\n",
427 tp
->pending_follow
.kind
);
431 return should_resume
;
435 follow_inferior_reset_breakpoints (void)
437 struct thread_info
*tp
= inferior_thread ();
439 /* Was there a step_resume breakpoint? (There was if the user
440 did a "next" at the fork() call.) If so, explicitly reset its
443 step_resumes are a form of bp that are made to be per-thread.
444 Since we created the step_resume bp when the parent process
445 was being debugged, and now are switching to the child process,
446 from the breakpoint package's viewpoint, that's a switch of
447 "threads". We must update the bp's notion of which thread
448 it is for, or it'll be ignored when it triggers. */
450 if (tp
->step_resume_breakpoint
)
451 breakpoint_re_set_thread (tp
->step_resume_breakpoint
);
453 /* Reinsert all breakpoints in the child. The user may have set
454 breakpoints after catching the fork, in which case those
455 were never set in the child, but only in the parent. This makes
456 sure the inserted breakpoints match the breakpoint list. */
458 breakpoint_re_set ();
459 insert_breakpoints ();
462 /* EXECD_PATHNAME is assumed to be non-NULL. */
465 follow_exec (ptid_t pid
, char *execd_pathname
)
467 struct target_ops
*tgt
;
468 struct thread_info
*th
= inferior_thread ();
470 /* This is an exec event that we actually wish to pay attention to.
471 Refresh our symbol table to the newly exec'd program, remove any
474 If there are breakpoints, they aren't really inserted now,
475 since the exec() transformed our inferior into a fresh set
478 We want to preserve symbolic breakpoints on the list, since
479 we have hopes that they can be reset after the new a.out's
480 symbol table is read.
482 However, any "raw" breakpoints must be removed from the list
483 (e.g., the solib bp's), since their address is probably invalid
486 And, we DON'T want to call delete_breakpoints() here, since
487 that may write the bp's "shadow contents" (the instruction
488 value that was overwritten witha TRAP instruction). Since
489 we now have a new a.out, those shadow contents aren't valid. */
490 update_breakpoints_after_exec ();
492 /* If there was one, it's gone now. We cannot truly step-to-next
493 statement through an exec(). */
494 th
->step_resume_breakpoint
= NULL
;
495 th
->step_range_start
= 0;
496 th
->step_range_end
= 0;
498 /* The target reports the exec event to the main thread, even if
499 some other thread does the exec, and even if the main thread was
500 already stopped --- if debugging in non-stop mode, it's possible
501 the user had the main thread held stopped in the previous image
502 --- release it now. This is the same behavior as step-over-exec
503 with scheduler-locking on in all-stop mode. */
504 th
->stop_requested
= 0;
506 /* What is this a.out's name? */
507 printf_unfiltered (_("Executing new program: %s\n"), execd_pathname
);
509 /* We've followed the inferior through an exec. Therefore, the
510 inferior has essentially been killed & reborn. */
512 gdb_flush (gdb_stdout
);
514 breakpoint_init_inferior (inf_execd
);
516 if (gdb_sysroot
&& *gdb_sysroot
)
518 char *name
= alloca (strlen (gdb_sysroot
)
519 + strlen (execd_pathname
)
521 strcpy (name
, gdb_sysroot
);
522 strcat (name
, execd_pathname
);
523 execd_pathname
= name
;
526 /* That a.out is now the one to use. */
527 exec_file_attach (execd_pathname
, 0);
529 /* Reset the shared library package. This ensures that we get a
530 shlib event when the child reaches "_start", at which point the
531 dld will have had a chance to initialize the child. */
532 /* Also, loading a symbol file below may trigger symbol lookups, and
533 we don't want those to be satisfied by the libraries of the
534 previous incarnation of this process. */
535 no_shared_libraries (NULL
, 0);
537 /* Load the main file's symbols. */
538 symbol_file_add_main (execd_pathname
, 0);
540 #ifdef SOLIB_CREATE_INFERIOR_HOOK
541 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid
));
543 solib_create_inferior_hook ();
546 /* Reinsert all breakpoints. (Those which were symbolic have
547 been reset to the proper address in the new a.out, thanks
548 to symbol_file_command...) */
549 insert_breakpoints ();
551 /* The next resume of this inferior should bring it to the shlib
552 startup breakpoints. (If the user had also set bp's on
553 "main" from the old (parent) process, then they'll auto-
554 matically get reset there in the new process.) */
557 /* Non-zero if we just simulating a single-step. This is needed
558 because we cannot remove the breakpoints in the inferior process
559 until after the `wait' in `wait_for_inferior'. */
560 static int singlestep_breakpoints_inserted_p
= 0;
562 /* The thread we inserted single-step breakpoints for. */
563 static ptid_t singlestep_ptid
;
565 /* PC when we started this single-step. */
566 static CORE_ADDR singlestep_pc
;
568 /* If another thread hit the singlestep breakpoint, we save the original
569 thread here so that we can resume single-stepping it later. */
570 static ptid_t saved_singlestep_ptid
;
571 static int stepping_past_singlestep_breakpoint
;
573 /* If not equal to null_ptid, this means that after stepping over breakpoint
574 is finished, we need to switch to deferred_step_ptid, and step it.
576 The use case is when one thread has hit a breakpoint, and then the user
577 has switched to another thread and issued 'step'. We need to step over
578 breakpoint in the thread which hit the breakpoint, but then continue
579 stepping the thread user has selected. */
580 static ptid_t deferred_step_ptid
;
582 /* Displaced stepping. */
584 /* In non-stop debugging mode, we must take special care to manage
585 breakpoints properly; in particular, the traditional strategy for
586 stepping a thread past a breakpoint it has hit is unsuitable.
587 'Displaced stepping' is a tactic for stepping one thread past a
588 breakpoint it has hit while ensuring that other threads running
589 concurrently will hit the breakpoint as they should.
591 The traditional way to step a thread T off a breakpoint in a
592 multi-threaded program in all-stop mode is as follows:
594 a0) Initially, all threads are stopped, and breakpoints are not
596 a1) We single-step T, leaving breakpoints uninserted.
597 a2) We insert breakpoints, and resume all threads.
599 In non-stop debugging, however, this strategy is unsuitable: we
600 don't want to have to stop all threads in the system in order to
601 continue or step T past a breakpoint. Instead, we use displaced
604 n0) Initially, T is stopped, other threads are running, and
605 breakpoints are inserted.
606 n1) We copy the instruction "under" the breakpoint to a separate
607 location, outside the main code stream, making any adjustments
608 to the instruction, register, and memory state as directed by
610 n2) We single-step T over the instruction at its new location.
611 n3) We adjust the resulting register and memory state as directed
612 by T's architecture. This includes resetting T's PC to point
613 back into the main instruction stream.
616 This approach depends on the following gdbarch methods:
618 - gdbarch_max_insn_length and gdbarch_displaced_step_location
619 indicate where to copy the instruction, and how much space must
620 be reserved there. We use these in step n1.
622 - gdbarch_displaced_step_copy_insn copies a instruction to a new
623 address, and makes any necessary adjustments to the instruction,
624 register contents, and memory. We use this in step n1.
626 - gdbarch_displaced_step_fixup adjusts registers and memory after
627 we have successfuly single-stepped the instruction, to yield the
628 same effect the instruction would have had if we had executed it
629 at its original address. We use this in step n3.
631 - gdbarch_displaced_step_free_closure provides cleanup.
633 The gdbarch_displaced_step_copy_insn and
634 gdbarch_displaced_step_fixup functions must be written so that
635 copying an instruction with gdbarch_displaced_step_copy_insn,
636 single-stepping across the copied instruction, and then applying
637 gdbarch_displaced_insn_fixup should have the same effects on the
638 thread's memory and registers as stepping the instruction in place
639 would have. Exactly which responsibilities fall to the copy and
640 which fall to the fixup is up to the author of those functions.
642 See the comments in gdbarch.sh for details.
644 Note that displaced stepping and software single-step cannot
645 currently be used in combination, although with some care I think
646 they could be made to. Software single-step works by placing
647 breakpoints on all possible subsequent instructions; if the
648 displaced instruction is a PC-relative jump, those breakpoints
649 could fall in very strange places --- on pages that aren't
650 executable, or at addresses that are not proper instruction
651 boundaries. (We do generally let other threads run while we wait
652 to hit the software single-step breakpoint, and they might
653 encounter such a corrupted instruction.) One way to work around
654 this would be to have gdbarch_displaced_step_copy_insn fully
655 simulate the effect of PC-relative instructions (and return NULL)
656 on architectures that use software single-stepping.
658 In non-stop mode, we can have independent and simultaneous step
659 requests, so more than one thread may need to simultaneously step
660 over a breakpoint. The current implementation assumes there is
661 only one scratch space per process. In this case, we have to
662 serialize access to the scratch space. If thread A wants to step
663 over a breakpoint, but we are currently waiting for some other
664 thread to complete a displaced step, we leave thread A stopped and
665 place it in the displaced_step_request_queue. Whenever a displaced
666 step finishes, we pick the next thread in the queue and start a new
667 displaced step operation on it. See displaced_step_prepare and
668 displaced_step_fixup for details. */
670 /* If this is not null_ptid, this is the thread carrying out a
671 displaced single-step. This thread's state will require fixing up
672 once it has completed its step. */
673 static ptid_t displaced_step_ptid
;
675 struct displaced_step_request
678 struct displaced_step_request
*next
;
681 /* A queue of pending displaced stepping requests. */
682 struct displaced_step_request
*displaced_step_request_queue
;
684 /* The architecture the thread had when we stepped it. */
685 static struct gdbarch
*displaced_step_gdbarch
;
687 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
688 for post-step cleanup. */
689 static struct displaced_step_closure
*displaced_step_closure
;
691 /* The address of the original instruction, and the copy we made. */
692 static CORE_ADDR displaced_step_original
, displaced_step_copy
;
694 /* Saved contents of copy area. */
695 static gdb_byte
*displaced_step_saved_copy
;
697 /* Enum strings for "set|show displaced-stepping". */
699 static const char can_use_displaced_stepping_auto
[] = "auto";
700 static const char can_use_displaced_stepping_on
[] = "on";
701 static const char can_use_displaced_stepping_off
[] = "off";
702 static const char *can_use_displaced_stepping_enum
[] =
704 can_use_displaced_stepping_auto
,
705 can_use_displaced_stepping_on
,
706 can_use_displaced_stepping_off
,
710 /* If ON, and the architecture supports it, GDB will use displaced
711 stepping to step over breakpoints. If OFF, or if the architecture
712 doesn't support it, GDB will instead use the traditional
713 hold-and-step approach. If AUTO (which is the default), GDB will
714 decide which technique to use to step over breakpoints depending on
715 which of all-stop or non-stop mode is active --- displaced stepping
716 in non-stop mode; hold-and-step in all-stop mode. */
718 static const char *can_use_displaced_stepping
=
719 can_use_displaced_stepping_auto
;
722 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
723 struct cmd_list_element
*c
,
726 if (can_use_displaced_stepping
== can_use_displaced_stepping_auto
)
727 fprintf_filtered (file
, _("\
728 Debugger's willingness to use displaced stepping to step over \
729 breakpoints is %s (currently %s).\n"),
730 value
, non_stop
? "on" : "off");
732 fprintf_filtered (file
, _("\
733 Debugger's willingness to use displaced stepping to step over \
734 breakpoints is %s.\n"), value
);
737 /* Return non-zero if displaced stepping can/should be used to step
741 use_displaced_stepping (struct gdbarch
*gdbarch
)
743 return (((can_use_displaced_stepping
== can_use_displaced_stepping_auto
745 || can_use_displaced_stepping
== can_use_displaced_stepping_on
)
746 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
750 /* Clean out any stray displaced stepping state. */
752 displaced_step_clear (void)
754 /* Indicate that there is no cleanup pending. */
755 displaced_step_ptid
= null_ptid
;
757 if (displaced_step_closure
)
759 gdbarch_displaced_step_free_closure (displaced_step_gdbarch
,
760 displaced_step_closure
);
761 displaced_step_closure
= NULL
;
766 cleanup_displaced_step_closure (void *ptr
)
768 struct displaced_step_closure
*closure
= ptr
;
770 gdbarch_displaced_step_free_closure (current_gdbarch
, closure
);
773 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
775 displaced_step_dump_bytes (struct ui_file
*file
,
781 for (i
= 0; i
< len
; i
++)
782 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
783 fputs_unfiltered ("\n", file
);
786 /* Prepare to single-step, using displaced stepping.
788 Note that we cannot use displaced stepping when we have a signal to
789 deliver. If we have a signal to deliver and an instruction to step
790 over, then after the step, there will be no indication from the
791 target whether the thread entered a signal handler or ignored the
792 signal and stepped over the instruction successfully --- both cases
793 result in a simple SIGTRAP. In the first case we mustn't do a
794 fixup, and in the second case we must --- but we can't tell which.
795 Comments in the code for 'random signals' in handle_inferior_event
796 explain how we handle this case instead.
798 Returns 1 if preparing was successful -- this thread is going to be
799 stepped now; or 0 if displaced stepping this thread got queued. */
801 displaced_step_prepare (ptid_t ptid
)
803 struct cleanup
*old_cleanups
, *ignore_cleanups
;
804 struct regcache
*regcache
= get_thread_regcache (ptid
);
805 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
806 CORE_ADDR original
, copy
;
808 struct displaced_step_closure
*closure
;
810 /* We should never reach this function if the architecture does not
811 support displaced stepping. */
812 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
814 /* For the first cut, we're displaced stepping one thread at a
817 if (!ptid_equal (displaced_step_ptid
, null_ptid
))
819 /* Already waiting for a displaced step to finish. Defer this
820 request and place in queue. */
821 struct displaced_step_request
*req
, *new_req
;
824 fprintf_unfiltered (gdb_stdlog
,
825 "displaced: defering step of %s\n",
826 target_pid_to_str (ptid
));
828 new_req
= xmalloc (sizeof (*new_req
));
829 new_req
->ptid
= ptid
;
830 new_req
->next
= NULL
;
832 if (displaced_step_request_queue
)
834 for (req
= displaced_step_request_queue
;
841 displaced_step_request_queue
= new_req
;
848 fprintf_unfiltered (gdb_stdlog
,
849 "displaced: stepping %s now\n",
850 target_pid_to_str (ptid
));
853 displaced_step_clear ();
855 old_cleanups
= save_inferior_ptid ();
856 inferior_ptid
= ptid
;
858 original
= regcache_read_pc (regcache
);
860 copy
= gdbarch_displaced_step_location (gdbarch
);
861 len
= gdbarch_max_insn_length (gdbarch
);
863 /* Save the original contents of the copy area. */
864 displaced_step_saved_copy
= xmalloc (len
);
865 ignore_cleanups
= make_cleanup (free_current_contents
,
866 &displaced_step_saved_copy
);
867 read_memory (copy
, displaced_step_saved_copy
, len
);
870 fprintf_unfiltered (gdb_stdlog
, "displaced: saved 0x%s: ",
872 displaced_step_dump_bytes (gdb_stdlog
, displaced_step_saved_copy
, len
);
875 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
876 original
, copy
, regcache
);
878 /* We don't support the fully-simulated case at present. */
879 gdb_assert (closure
);
881 make_cleanup (cleanup_displaced_step_closure
, closure
);
883 /* Resume execution at the copy. */
884 regcache_write_pc (regcache
, copy
);
886 discard_cleanups (ignore_cleanups
);
888 do_cleanups (old_cleanups
);
891 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to 0x%s\n",
894 /* Save the information we need to fix things up if the step
896 displaced_step_ptid
= ptid
;
897 displaced_step_gdbarch
= gdbarch
;
898 displaced_step_closure
= closure
;
899 displaced_step_original
= original
;
900 displaced_step_copy
= copy
;
905 displaced_step_clear_cleanup (void *ignore
)
907 displaced_step_clear ();
911 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
, const gdb_byte
*myaddr
, int len
)
913 struct cleanup
*ptid_cleanup
= save_inferior_ptid ();
914 inferior_ptid
= ptid
;
915 write_memory (memaddr
, myaddr
, len
);
916 do_cleanups (ptid_cleanup
);
920 displaced_step_fixup (ptid_t event_ptid
, enum target_signal signal
)
922 struct cleanup
*old_cleanups
;
924 /* Was this event for the pid we displaced? */
925 if (ptid_equal (displaced_step_ptid
, null_ptid
)
926 || ! ptid_equal (displaced_step_ptid
, event_ptid
))
929 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, 0);
931 /* Restore the contents of the copy area. */
933 ULONGEST len
= gdbarch_max_insn_length (displaced_step_gdbarch
);
934 write_memory_ptid (displaced_step_ptid
, displaced_step_copy
,
935 displaced_step_saved_copy
, len
);
937 fprintf_unfiltered (gdb_stdlog
, "displaced: restored 0x%s\n",
938 paddr_nz (displaced_step_copy
));
941 /* Did the instruction complete successfully? */
942 if (signal
== TARGET_SIGNAL_TRAP
)
944 /* Fix up the resulting state. */
945 gdbarch_displaced_step_fixup (displaced_step_gdbarch
,
946 displaced_step_closure
,
947 displaced_step_original
,
949 get_thread_regcache (displaced_step_ptid
));
953 /* Since the instruction didn't complete, all we can do is
955 struct regcache
*regcache
= get_thread_regcache (event_ptid
);
956 CORE_ADDR pc
= regcache_read_pc (regcache
);
957 pc
= displaced_step_original
+ (pc
- displaced_step_copy
);
958 regcache_write_pc (regcache
, pc
);
961 do_cleanups (old_cleanups
);
963 displaced_step_ptid
= null_ptid
;
965 /* Are there any pending displaced stepping requests? If so, run
967 while (displaced_step_request_queue
)
969 struct displaced_step_request
*head
;
973 head
= displaced_step_request_queue
;
975 displaced_step_request_queue
= head
->next
;
978 context_switch (ptid
);
980 actual_pc
= regcache_read_pc (get_thread_regcache (ptid
));
982 if (breakpoint_here_p (actual_pc
))
985 fprintf_unfiltered (gdb_stdlog
,
986 "displaced: stepping queued %s now\n",
987 target_pid_to_str (ptid
));
989 displaced_step_prepare (ptid
);
995 fprintf_unfiltered (gdb_stdlog
, "displaced: run 0x%s: ",
996 paddr_nz (actual_pc
));
997 read_memory (actual_pc
, buf
, sizeof (buf
));
998 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
1001 target_resume (ptid
, 1, TARGET_SIGNAL_0
);
1003 /* Done, we're stepping a thread. */
1009 struct thread_info
*tp
= inferior_thread ();
1011 /* The breakpoint we were sitting under has since been
1013 tp
->trap_expected
= 0;
1015 /* Go back to what we were trying to do. */
1016 step
= currently_stepping (tp
);
1018 if (debug_displaced
)
1019 fprintf_unfiltered (gdb_stdlog
, "breakpoint is gone %s: step(%d)\n",
1020 target_pid_to_str (tp
->ptid
), step
);
1022 target_resume (ptid
, step
, TARGET_SIGNAL_0
);
1023 tp
->stop_signal
= TARGET_SIGNAL_0
;
1025 /* This request was discarded. See if there's any other
1026 thread waiting for its turn. */
1031 /* Update global variables holding ptids to hold NEW_PTID if they were
1032 holding OLD_PTID. */
1034 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
1036 struct displaced_step_request
*it
;
1038 if (ptid_equal (inferior_ptid
, old_ptid
))
1039 inferior_ptid
= new_ptid
;
1041 if (ptid_equal (singlestep_ptid
, old_ptid
))
1042 singlestep_ptid
= new_ptid
;
1044 if (ptid_equal (displaced_step_ptid
, old_ptid
))
1045 displaced_step_ptid
= new_ptid
;
1047 if (ptid_equal (deferred_step_ptid
, old_ptid
))
1048 deferred_step_ptid
= new_ptid
;
1050 for (it
= displaced_step_request_queue
; it
; it
= it
->next
)
1051 if (ptid_equal (it
->ptid
, old_ptid
))
1052 it
->ptid
= new_ptid
;
1058 /* Things to clean up if we QUIT out of resume (). */
1060 resume_cleanups (void *ignore
)
1065 static const char schedlock_off
[] = "off";
1066 static const char schedlock_on
[] = "on";
1067 static const char schedlock_step
[] = "step";
1068 static const char *scheduler_enums
[] = {
1074 static const char *scheduler_mode
= schedlock_off
;
1076 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
1077 struct cmd_list_element
*c
, const char *value
)
1079 fprintf_filtered (file
, _("\
1080 Mode for locking scheduler during execution is \"%s\".\n"),
1085 set_schedlock_func (char *args
, int from_tty
, struct cmd_list_element
*c
)
1087 if (!target_can_lock_scheduler
)
1089 scheduler_mode
= schedlock_off
;
1090 error (_("Target '%s' cannot support this command."), target_shortname
);
1094 /* Try to setup for software single stepping over the specified location.
1095 Return 1 if target_resume() should use hardware single step.
1097 GDBARCH the current gdbarch.
1098 PC the location to step over. */
1101 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
1105 if (gdbarch_software_single_step_p (gdbarch
)
1106 && gdbarch_software_single_step (gdbarch
, get_current_frame ()))
1109 /* Do not pull these breakpoints until after a `wait' in
1110 `wait_for_inferior' */
1111 singlestep_breakpoints_inserted_p
= 1;
1112 singlestep_ptid
= inferior_ptid
;
1118 /* Resume the inferior, but allow a QUIT. This is useful if the user
1119 wants to interrupt some lengthy single-stepping operation
1120 (for child processes, the SIGINT goes to the inferior, and so
1121 we get a SIGINT random_signal, but for remote debugging and perhaps
1122 other targets, that's not true).
1124 STEP nonzero if we should step (zero to continue instead).
1125 SIG is the signal to give the inferior (zero for none). */
1127 resume (int step
, enum target_signal sig
)
1129 int should_resume
= 1;
1130 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
1131 struct regcache
*regcache
= get_current_regcache ();
1132 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1133 struct thread_info
*tp
= inferior_thread ();
1134 CORE_ADDR pc
= regcache_read_pc (regcache
);
1139 fprintf_unfiltered (gdb_stdlog
,
1140 "infrun: resume (step=%d, signal=%d), "
1141 "trap_expected=%d\n",
1142 step
, sig
, tp
->trap_expected
);
1144 /* Some targets (e.g. Solaris x86) have a kernel bug when stepping
1145 over an instruction that causes a page fault without triggering
1146 a hardware watchpoint. The kernel properly notices that it shouldn't
1147 stop, because the hardware watchpoint is not triggered, but it forgets
1148 the step request and continues the program normally.
1149 Work around the problem by removing hardware watchpoints if a step is
1150 requested, GDB will check for a hardware watchpoint trigger after the
1152 if (CANNOT_STEP_HW_WATCHPOINTS
&& step
)
1153 remove_hw_watchpoints ();
1156 /* Normally, by the time we reach `resume', the breakpoints are either
1157 removed or inserted, as appropriate. The exception is if we're sitting
1158 at a permanent breakpoint; we need to step over it, but permanent
1159 breakpoints can't be removed. So we have to test for it here. */
1160 if (breakpoint_here_p (pc
) == permanent_breakpoint_here
)
1162 if (gdbarch_skip_permanent_breakpoint_p (gdbarch
))
1163 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
1166 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1167 how to step past a permanent breakpoint on this architecture. Try using\n\
1168 a command like `return' or `jump' to continue execution."));
1171 /* If enabled, step over breakpoints by executing a copy of the
1172 instruction at a different address.
1174 We can't use displaced stepping when we have a signal to deliver;
1175 the comments for displaced_step_prepare explain why. The
1176 comments in the handle_inferior event for dealing with 'random
1177 signals' explain what we do instead. */
1178 if (use_displaced_stepping (gdbarch
)
1179 && tp
->trap_expected
1180 && sig
== TARGET_SIGNAL_0
)
1182 if (!displaced_step_prepare (inferior_ptid
))
1184 /* Got placed in displaced stepping queue. Will be resumed
1185 later when all the currently queued displaced stepping
1186 requests finish. The thread is not executing at this point,
1187 and the call to set_executing will be made later. But we
1188 need to call set_running here, since from frontend point of view,
1189 the thread is running. */
1190 set_running (inferior_ptid
, 1);
1191 discard_cleanups (old_cleanups
);
1196 /* Do we need to do it the hard way, w/temp breakpoints? */
1198 step
= maybe_software_singlestep (gdbarch
, pc
);
1204 resume_ptid
= RESUME_ALL
; /* Default */
1206 /* If STEP is set, it's a request to use hardware stepping
1207 facilities. But in that case, we should never
1208 use singlestep breakpoint. */
1209 gdb_assert (!(singlestep_breakpoints_inserted_p
&& step
));
1211 if (singlestep_breakpoints_inserted_p
1212 && stepping_past_singlestep_breakpoint
)
1214 /* The situation here is as follows. In thread T1 we wanted to
1215 single-step. Lacking hardware single-stepping we've
1216 set breakpoint at the PC of the next instruction -- call it
1217 P. After resuming, we've hit that breakpoint in thread T2.
1218 Now we've removed original breakpoint, inserted breakpoint
1219 at P+1, and try to step to advance T2 past breakpoint.
1220 We need to step only T2, as if T1 is allowed to freely run,
1221 it can run past P, and if other threads are allowed to run,
1222 they can hit breakpoint at P+1, and nested hits of single-step
1223 breakpoints is not something we'd want -- that's complicated
1224 to support, and has no value. */
1225 resume_ptid
= inferior_ptid
;
1228 if ((step
|| singlestep_breakpoints_inserted_p
)
1229 && tp
->trap_expected
)
1231 /* We're allowing a thread to run past a breakpoint it has
1232 hit, by single-stepping the thread with the breakpoint
1233 removed. In which case, we need to single-step only this
1234 thread, and keep others stopped, as they can miss this
1235 breakpoint if allowed to run.
1237 The current code actually removes all breakpoints when
1238 doing this, not just the one being stepped over, so if we
1239 let other threads run, we can actually miss any
1240 breakpoint, not just the one at PC. */
1241 resume_ptid
= inferior_ptid
;
1246 /* With non-stop mode on, threads are always handled
1248 resume_ptid
= inferior_ptid
;
1250 else if ((scheduler_mode
== schedlock_on
)
1251 || (scheduler_mode
== schedlock_step
1252 && (step
|| singlestep_breakpoints_inserted_p
)))
1254 /* User-settable 'scheduler' mode requires solo thread resume. */
1255 resume_ptid
= inferior_ptid
;
1258 if (gdbarch_cannot_step_breakpoint (gdbarch
))
1260 /* Most targets can step a breakpoint instruction, thus
1261 executing it normally. But if this one cannot, just
1262 continue and we will hit it anyway. */
1263 if (step
&& breakpoint_inserted_here_p (pc
))
1268 && use_displaced_stepping (gdbarch
)
1269 && tp
->trap_expected
)
1271 struct regcache
*resume_regcache
= get_thread_regcache (resume_ptid
);
1272 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
1275 fprintf_unfiltered (gdb_stdlog
, "displaced: run 0x%s: ",
1276 paddr_nz (actual_pc
));
1277 read_memory (actual_pc
, buf
, sizeof (buf
));
1278 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
1281 /* Install inferior's terminal modes. */
1282 target_terminal_inferior ();
1284 /* Avoid confusing the next resume, if the next stop/resume
1285 happens to apply to another thread. */
1286 tp
->stop_signal
= TARGET_SIGNAL_0
;
1288 target_resume (resume_ptid
, step
, sig
);
1291 discard_cleanups (old_cleanups
);
1296 /* Clear out all variables saying what to do when inferior is continued.
1297 First do this, then set the ones you want, then call `proceed'. */
1300 clear_proceed_status_thread (struct thread_info
*tp
)
1303 fprintf_unfiltered (gdb_stdlog
,
1304 "infrun: clear_proceed_status_thread (%s)\n",
1305 target_pid_to_str (tp
->ptid
));
1307 tp
->trap_expected
= 0;
1308 tp
->step_range_start
= 0;
1309 tp
->step_range_end
= 0;
1310 tp
->step_frame_id
= null_frame_id
;
1311 tp
->step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
1312 tp
->stop_requested
= 0;
1316 tp
->proceed_to_finish
= 0;
1318 /* Discard any remaining commands or status from previous stop. */
1319 bpstat_clear (&tp
->stop_bpstat
);
1323 clear_proceed_status_callback (struct thread_info
*tp
, void *data
)
1325 if (is_exited (tp
->ptid
))
1328 clear_proceed_status_thread (tp
);
1333 clear_proceed_status (void)
1335 if (!ptid_equal (inferior_ptid
, null_ptid
))
1337 struct inferior
*inferior
;
1341 /* If in non-stop mode, only delete the per-thread status
1342 of the current thread. */
1343 clear_proceed_status_thread (inferior_thread ());
1347 /* In all-stop mode, delete the per-thread status of
1349 iterate_over_threads (clear_proceed_status_callback
, NULL
);
1352 inferior
= current_inferior ();
1353 inferior
->stop_soon
= NO_STOP_QUIETLY
;
1356 stop_after_trap
= 0;
1358 observer_notify_about_to_proceed ();
1362 regcache_xfree (stop_registers
);
1363 stop_registers
= NULL
;
1367 /* This should be suitable for any targets that support threads. */
1370 prepare_to_proceed (int step
)
1373 struct target_waitstatus wait_status
;
1375 /* Get the last target status returned by target_wait(). */
1376 get_last_target_status (&wait_ptid
, &wait_status
);
1378 /* Make sure we were stopped at a breakpoint. */
1379 if (wait_status
.kind
!= TARGET_WAITKIND_STOPPED
1380 || wait_status
.value
.sig
!= TARGET_SIGNAL_TRAP
)
1385 /* Switched over from WAIT_PID. */
1386 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
1387 && !ptid_equal (inferior_ptid
, wait_ptid
))
1389 struct regcache
*regcache
= get_thread_regcache (wait_ptid
);
1391 if (breakpoint_here_p (regcache_read_pc (regcache
)))
1393 /* If stepping, remember current thread to switch back to. */
1395 deferred_step_ptid
= inferior_ptid
;
1397 /* Switch back to WAIT_PID thread. */
1398 switch_to_thread (wait_ptid
);
1400 /* We return 1 to indicate that there is a breakpoint here,
1401 so we need to step over it before continuing to avoid
1402 hitting it straight away. */
1410 /* Basic routine for continuing the program in various fashions.
1412 ADDR is the address to resume at, or -1 for resume where stopped.
1413 SIGGNAL is the signal to give it, or 0 for none,
1414 or -1 for act according to how it stopped.
1415 STEP is nonzero if should trap after one instruction.
1416 -1 means return after that and print nothing.
1417 You should probably set various step_... variables
1418 before calling here, if you are stepping.
1420 You should call clear_proceed_status before calling proceed. */
1423 proceed (CORE_ADDR addr
, enum target_signal siggnal
, int step
)
1425 struct regcache
*regcache
;
1426 struct gdbarch
*gdbarch
;
1427 struct thread_info
*tp
;
1431 /* If we're stopped at a fork/vfork, follow the branch set by the
1432 "set follow-fork-mode" command; otherwise, we'll just proceed
1433 resuming the current thread. */
1434 if (!follow_fork ())
1436 /* The target for some reason decided not to resume. */
1441 regcache
= get_current_regcache ();
1442 gdbarch
= get_regcache_arch (regcache
);
1443 pc
= regcache_read_pc (regcache
);
1446 step_start_function
= find_pc_function (pc
);
1448 stop_after_trap
= 1;
1450 if (addr
== (CORE_ADDR
) -1)
1452 if (pc
== stop_pc
&& breakpoint_here_p (pc
)
1453 && execution_direction
!= EXEC_REVERSE
)
1454 /* There is a breakpoint at the address we will resume at,
1455 step one instruction before inserting breakpoints so that
1456 we do not stop right away (and report a second hit at this
1459 Note, we don't do this in reverse, because we won't
1460 actually be executing the breakpoint insn anyway.
1461 We'll be (un-)executing the previous instruction. */
1464 else if (gdbarch_single_step_through_delay_p (gdbarch
)
1465 && gdbarch_single_step_through_delay (gdbarch
,
1466 get_current_frame ()))
1467 /* We stepped onto an instruction that needs to be stepped
1468 again before re-inserting the breakpoint, do so. */
1473 regcache_write_pc (regcache
, addr
);
1477 fprintf_unfiltered (gdb_stdlog
,
1478 "infrun: proceed (addr=0x%s, signal=%d, step=%d)\n",
1479 paddr_nz (addr
), siggnal
, step
);
1482 /* In non-stop, each thread is handled individually. The context
1483 must already be set to the right thread here. */
1487 /* In a multi-threaded task we may select another thread and
1488 then continue or step.
1490 But if the old thread was stopped at a breakpoint, it will
1491 immediately cause another breakpoint stop without any
1492 execution (i.e. it will report a breakpoint hit incorrectly).
1493 So we must step over it first.
1495 prepare_to_proceed checks the current thread against the
1496 thread that reported the most recent event. If a step-over
1497 is required it returns TRUE and sets the current thread to
1499 if (prepare_to_proceed (step
))
1503 /* prepare_to_proceed may change the current thread. */
1504 tp
= inferior_thread ();
1508 tp
->trap_expected
= 1;
1509 /* If displaced stepping is enabled, we can step over the
1510 breakpoint without hitting it, so leave all breakpoints
1511 inserted. Otherwise we need to disable all breakpoints, step
1512 one instruction, and then re-add them when that step is
1514 if (!use_displaced_stepping (gdbarch
))
1515 remove_breakpoints ();
1518 /* We can insert breakpoints if we're not trying to step over one,
1519 or if we are stepping over one but we're using displaced stepping
1521 if (! tp
->trap_expected
|| use_displaced_stepping (gdbarch
))
1522 insert_breakpoints ();
1526 /* Pass the last stop signal to the thread we're resuming,
1527 irrespective of whether the current thread is the thread that
1528 got the last event or not. This was historically GDB's
1529 behaviour before keeping a stop_signal per thread. */
1531 struct thread_info
*last_thread
;
1533 struct target_waitstatus last_status
;
1535 get_last_target_status (&last_ptid
, &last_status
);
1536 if (!ptid_equal (inferior_ptid
, last_ptid
)
1537 && !ptid_equal (last_ptid
, null_ptid
)
1538 && !ptid_equal (last_ptid
, minus_one_ptid
))
1540 last_thread
= find_thread_ptid (last_ptid
);
1543 tp
->stop_signal
= last_thread
->stop_signal
;
1544 last_thread
->stop_signal
= TARGET_SIGNAL_0
;
1549 if (siggnal
!= TARGET_SIGNAL_DEFAULT
)
1550 tp
->stop_signal
= siggnal
;
1551 /* If this signal should not be seen by program,
1552 give it zero. Used for debugging signals. */
1553 else if (!signal_program
[tp
->stop_signal
])
1554 tp
->stop_signal
= TARGET_SIGNAL_0
;
1556 annotate_starting ();
1558 /* Make sure that output from GDB appears before output from the
1560 gdb_flush (gdb_stdout
);
1562 /* Refresh prev_pc value just prior to resuming. This used to be
1563 done in stop_stepping, however, setting prev_pc there did not handle
1564 scenarios such as inferior function calls or returning from
1565 a function via the return command. In those cases, the prev_pc
1566 value was not set properly for subsequent commands. The prev_pc value
1567 is used to initialize the starting line number in the ecs. With an
1568 invalid value, the gdb next command ends up stopping at the position
1569 represented by the next line table entry past our start position.
1570 On platforms that generate one line table entry per line, this
1571 is not a problem. However, on the ia64, the compiler generates
1572 extraneous line table entries that do not increase the line number.
1573 When we issue the gdb next command on the ia64 after an inferior call
1574 or a return command, we often end up a few instructions forward, still
1575 within the original line we started.
1577 An attempt was made to have init_execution_control_state () refresh
1578 the prev_pc value before calculating the line number. This approach
1579 did not work because on platforms that use ptrace, the pc register
1580 cannot be read unless the inferior is stopped. At that point, we
1581 are not guaranteed the inferior is stopped and so the regcache_read_pc ()
1582 call can fail. Setting the prev_pc value here ensures the value is
1583 updated correctly when the inferior is stopped. */
1584 tp
->prev_pc
= regcache_read_pc (get_current_regcache ());
1586 /* Fill in with reasonable starting values. */
1587 init_thread_stepping_state (tp
);
1589 /* Reset to normal state. */
1590 init_infwait_state ();
1592 /* Resume inferior. */
1593 resume (oneproc
|| step
|| bpstat_should_step (), tp
->stop_signal
);
1595 /* Wait for it to stop (if not standalone)
1596 and in any case decode why it stopped, and act accordingly. */
1597 /* Do this only if we are not using the event loop, or if the target
1598 does not support asynchronous execution. */
1599 if (!target_can_async_p ())
1601 wait_for_inferior (0);
1607 /* Start remote-debugging of a machine over a serial link. */
1610 start_remote (int from_tty
)
1612 struct inferior
*inferior
;
1613 init_wait_for_inferior ();
1615 inferior
= current_inferior ();
1616 inferior
->stop_soon
= STOP_QUIETLY_REMOTE
;
1618 /* Always go on waiting for the target, regardless of the mode. */
1619 /* FIXME: cagney/1999-09-23: At present it isn't possible to
1620 indicate to wait_for_inferior that a target should timeout if
1621 nothing is returned (instead of just blocking). Because of this,
1622 targets expecting an immediate response need to, internally, set
1623 things up so that the target_wait() is forced to eventually
1625 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
1626 differentiate to its caller what the state of the target is after
1627 the initial open has been performed. Here we're assuming that
1628 the target has stopped. It should be possible to eventually have
1629 target_open() return to the caller an indication that the target
1630 is currently running and GDB state should be set to the same as
1631 for an async run. */
1632 wait_for_inferior (0);
1634 /* Now that the inferior has stopped, do any bookkeeping like
1635 loading shared libraries. We want to do this before normal_stop,
1636 so that the displayed frame is up to date. */
1637 post_create_inferior (¤t_target
, from_tty
);
1642 /* Initialize static vars when a new inferior begins. */
1645 init_wait_for_inferior (void)
1647 /* These are meaningless until the first time through wait_for_inferior. */
1649 breakpoint_init_inferior (inf_starting
);
1651 clear_proceed_status ();
1653 stepping_past_singlestep_breakpoint
= 0;
1654 deferred_step_ptid
= null_ptid
;
1656 target_last_wait_ptid
= minus_one_ptid
;
1658 previous_inferior_ptid
= null_ptid
;
1659 init_infwait_state ();
1661 displaced_step_clear ();
1665 /* This enum encodes possible reasons for doing a target_wait, so that
1666 wfi can call target_wait in one place. (Ultimately the call will be
1667 moved out of the infinite loop entirely.) */
1671 infwait_normal_state
,
1672 infwait_thread_hop_state
,
1673 infwait_step_watch_state
,
1674 infwait_nonstep_watch_state
1677 /* Why did the inferior stop? Used to print the appropriate messages
1678 to the interface from within handle_inferior_event(). */
1679 enum inferior_stop_reason
1681 /* Step, next, nexti, stepi finished. */
1683 /* Inferior terminated by signal. */
1685 /* Inferior exited. */
1687 /* Inferior received signal, and user asked to be notified. */
1689 /* Reverse execution -- target ran out of history info. */
1693 /* The PTID we'll do a target_wait on.*/
1696 /* Current inferior wait state. */
1697 enum infwait_states infwait_state
;
1699 /* Data to be passed around while handling an event. This data is
1700 discarded between events. */
1701 struct execution_control_state
1704 /* The thread that got the event, if this was a thread event; NULL
1706 struct thread_info
*event_thread
;
1708 struct target_waitstatus ws
;
1710 CORE_ADDR stop_func_start
;
1711 CORE_ADDR stop_func_end
;
1712 char *stop_func_name
;
1713 int new_thread_event
;
1717 void init_execution_control_state (struct execution_control_state
*ecs
);
1719 void handle_inferior_event (struct execution_control_state
*ecs
);
1721 static void handle_step_into_function (struct execution_control_state
*ecs
);
1722 static void handle_step_into_function_backward (struct execution_control_state
*ecs
);
1723 static void insert_step_resume_breakpoint_at_frame (struct frame_info
*step_frame
);
1724 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
1725 static void insert_step_resume_breakpoint_at_sal (struct symtab_and_line sr_sal
,
1726 struct frame_id sr_id
);
1727 static void insert_longjmp_resume_breakpoint (CORE_ADDR
);
1729 static void stop_stepping (struct execution_control_state
*ecs
);
1730 static void prepare_to_wait (struct execution_control_state
*ecs
);
1731 static void keep_going (struct execution_control_state
*ecs
);
1732 static void print_stop_reason (enum inferior_stop_reason stop_reason
,
1735 /* Callback for iterate over threads. If the thread is stopped, but
1736 the user/frontend doesn't know about that yet, go through
1737 normal_stop, as if the thread had just stopped now. ARG points at
1738 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
1739 ptid_is_pid(PTID) is true, applies to all threads of the process
1740 pointed at by PTID. Otherwise, apply only to the thread pointed by
1744 infrun_thread_stop_requested_callback (struct thread_info
*info
, void *arg
)
1746 ptid_t ptid
= * (ptid_t
*) arg
;
1748 if ((ptid_equal (info
->ptid
, ptid
)
1749 || ptid_equal (minus_one_ptid
, ptid
)
1750 || (ptid_is_pid (ptid
)
1751 && ptid_get_pid (ptid
) == ptid_get_pid (info
->ptid
)))
1752 && is_running (info
->ptid
)
1753 && !is_executing (info
->ptid
))
1755 struct cleanup
*old_chain
;
1756 struct execution_control_state ecss
;
1757 struct execution_control_state
*ecs
= &ecss
;
1759 memset (ecs
, 0, sizeof (*ecs
));
1761 old_chain
= make_cleanup_restore_current_thread ();
1763 switch_to_thread (info
->ptid
);
1765 /* Go through handle_inferior_event/normal_stop, so we always
1766 have consistent output as if the stop event had been
1768 ecs
->ptid
= info
->ptid
;
1769 ecs
->event_thread
= find_thread_ptid (info
->ptid
);
1770 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
1771 ecs
->ws
.value
.sig
= TARGET_SIGNAL_0
;
1773 handle_inferior_event (ecs
);
1775 if (!ecs
->wait_some_more
)
1777 struct thread_info
*tp
;
1781 /* Finish off the continuations. The continations
1782 themselves are responsible for realising the thread
1783 didn't finish what it was supposed to do. */
1784 tp
= inferior_thread ();
1785 do_all_intermediate_continuations_thread (tp
);
1786 do_all_continuations_thread (tp
);
1789 do_cleanups (old_chain
);
1795 /* This function is attached as a "thread_stop_requested" observer.
1796 Cleanup local state that assumed the PTID was to be resumed, and
1797 report the stop to the frontend. */
1800 infrun_thread_stop_requested (ptid_t ptid
)
1802 struct displaced_step_request
*it
, *next
, *prev
= NULL
;
1804 /* PTID was requested to stop. Remove it from the displaced
1805 stepping queue, so we don't try to resume it automatically. */
1806 for (it
= displaced_step_request_queue
; it
; it
= next
)
1810 if (ptid_equal (it
->ptid
, ptid
)
1811 || ptid_equal (minus_one_ptid
, ptid
)
1812 || (ptid_is_pid (ptid
)
1813 && ptid_get_pid (ptid
) == ptid_get_pid (it
->ptid
)))
1815 if (displaced_step_request_queue
== it
)
1816 displaced_step_request_queue
= it
->next
;
1818 prev
->next
= it
->next
;
1826 iterate_over_threads (infrun_thread_stop_requested_callback
, &ptid
);
1830 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
1832 if (ptid_equal (target_last_wait_ptid
, tp
->ptid
))
1833 nullify_last_target_wait_ptid ();
1836 /* Callback for iterate_over_threads. */
1839 delete_step_resume_breakpoint_callback (struct thread_info
*info
, void *data
)
1841 if (is_exited (info
->ptid
))
1844 delete_step_resume_breakpoint (info
);
1848 /* In all-stop, delete the step resume breakpoint of any thread that
1849 had one. In non-stop, delete the step resume breakpoint of the
1850 thread that just stopped. */
1853 delete_step_thread_step_resume_breakpoint (void)
1855 if (!target_has_execution
1856 || ptid_equal (inferior_ptid
, null_ptid
))
1857 /* If the inferior has exited, we have already deleted the step
1858 resume breakpoints out of GDB's lists. */
1863 /* If in non-stop mode, only delete the step-resume or
1864 longjmp-resume breakpoint of the thread that just stopped
1866 struct thread_info
*tp
= inferior_thread ();
1867 delete_step_resume_breakpoint (tp
);
1870 /* In all-stop mode, delete all step-resume and longjmp-resume
1871 breakpoints of any thread that had them. */
1872 iterate_over_threads (delete_step_resume_breakpoint_callback
, NULL
);
1875 /* A cleanup wrapper. */
1878 delete_step_thread_step_resume_breakpoint_cleanup (void *arg
)
1880 delete_step_thread_step_resume_breakpoint ();
1883 /* Pretty print the results of target_wait, for debugging purposes. */
1886 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
1887 const struct target_waitstatus
*ws
)
1889 char *status_string
= target_waitstatus_to_string (ws
);
1890 struct ui_file
*tmp_stream
= mem_fileopen ();
1894 /* The text is split over several lines because it was getting too long.
1895 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
1896 output as a unit; we want only one timestamp printed if debug_timestamp
1899 fprintf_unfiltered (tmp_stream
,
1900 "infrun: target_wait (%d", PIDGET (waiton_ptid
));
1901 if (PIDGET (waiton_ptid
) != -1)
1902 fprintf_unfiltered (tmp_stream
,
1903 " [%s]", target_pid_to_str (waiton_ptid
));
1904 fprintf_unfiltered (tmp_stream
, ", status) =\n");
1905 fprintf_unfiltered (tmp_stream
,
1906 "infrun: %d [%s],\n",
1907 PIDGET (result_ptid
), target_pid_to_str (result_ptid
));
1908 fprintf_unfiltered (tmp_stream
,
1912 text
= ui_file_xstrdup (tmp_stream
, &len
);
1914 /* This uses %s in part to handle %'s in the text, but also to avoid
1915 a gcc error: the format attribute requires a string literal. */
1916 fprintf_unfiltered (gdb_stdlog
, "%s", text
);
1918 xfree (status_string
);
1920 ui_file_delete (tmp_stream
);
1923 /* Wait for control to return from inferior to debugger.
1925 If TREAT_EXEC_AS_SIGTRAP is non-zero, then handle EXEC signals
1926 as if they were SIGTRAP signals. This can be useful during
1927 the startup sequence on some targets such as HP/UX, where
1928 we receive an EXEC event instead of the expected SIGTRAP.
1930 If inferior gets a signal, we may decide to start it up again
1931 instead of returning. That is why there is a loop in this function.
1932 When this function actually returns it means the inferior
1933 should be left stopped and GDB should read more commands. */
1936 wait_for_inferior (int treat_exec_as_sigtrap
)
1938 struct cleanup
*old_cleanups
;
1939 struct execution_control_state ecss
;
1940 struct execution_control_state
*ecs
;
1944 (gdb_stdlog
, "infrun: wait_for_inferior (treat_exec_as_sigtrap=%d)\n",
1945 treat_exec_as_sigtrap
);
1948 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup
, NULL
);
1951 memset (ecs
, 0, sizeof (*ecs
));
1953 overlay_cache_invalid
= 1;
1955 /* We'll update this if & when we switch to a new thread. */
1956 previous_inferior_ptid
= inferior_ptid
;
1958 /* We have to invalidate the registers BEFORE calling target_wait
1959 because they can be loaded from the target while in target_wait.
1960 This makes remote debugging a bit more efficient for those
1961 targets that provide critical registers as part of their normal
1962 status mechanism. */
1964 registers_changed ();
1968 struct cleanup
*old_chain
;
1970 if (deprecated_target_wait_hook
)
1971 ecs
->ptid
= deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, 0);
1973 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, 0);
1976 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
1978 if (treat_exec_as_sigtrap
&& ecs
->ws
.kind
== TARGET_WAITKIND_EXECD
)
1980 xfree (ecs
->ws
.value
.execd_pathname
);
1981 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
1982 ecs
->ws
.value
.sig
= TARGET_SIGNAL_TRAP
;
1985 /* If an error happens while handling the event, propagate GDB's
1986 knowledge of the executing state to the frontend/user running
1988 old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
1990 /* Now figure out what to do with the result of the result. */
1991 handle_inferior_event (ecs
);
1993 /* No error, don't finish the state yet. */
1994 discard_cleanups (old_chain
);
1996 if (!ecs
->wait_some_more
)
2000 do_cleanups (old_cleanups
);
2003 /* Asynchronous version of wait_for_inferior. It is called by the
2004 event loop whenever a change of state is detected on the file
2005 descriptor corresponding to the target. It can be called more than
2006 once to complete a single execution command. In such cases we need
2007 to keep the state in a global variable ECSS. If it is the last time
2008 that this function is called for a single execution command, then
2009 report to the user that the inferior has stopped, and do the
2010 necessary cleanups. */
2013 fetch_inferior_event (void *client_data
)
2015 struct execution_control_state ecss
;
2016 struct execution_control_state
*ecs
= &ecss
;
2017 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
2018 struct cleanup
*ts_old_chain
;
2019 int was_sync
= sync_execution
;
2021 memset (ecs
, 0, sizeof (*ecs
));
2023 overlay_cache_invalid
= 1;
2025 /* We can only rely on wait_for_more being correct before handling
2026 the event in all-stop, but previous_inferior_ptid isn't used in
2028 if (!ecs
->wait_some_more
)
2029 /* We'll update this if & when we switch to a new thread. */
2030 previous_inferior_ptid
= inferior_ptid
;
2033 /* In non-stop mode, the user/frontend should not notice a thread
2034 switch due to internal events. Make sure we reverse to the
2035 user selected thread and frame after handling the event and
2036 running any breakpoint commands. */
2037 make_cleanup_restore_current_thread ();
2039 /* We have to invalidate the registers BEFORE calling target_wait
2040 because they can be loaded from the target while in target_wait.
2041 This makes remote debugging a bit more efficient for those
2042 targets that provide critical registers as part of their normal
2043 status mechanism. */
2045 registers_changed ();
2047 if (deprecated_target_wait_hook
)
2049 deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
2051 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
2054 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
2057 && ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
2058 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2059 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
2060 /* In non-stop mode, each thread is handled individually. Switch
2061 early, so the global state is set correctly for this
2063 context_switch (ecs
->ptid
);
2065 /* If an error happens while handling the event, propagate GDB's
2066 knowledge of the executing state to the frontend/user running
2069 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
2071 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &ecs
->ptid
);
2073 /* Now figure out what to do with the result of the result. */
2074 handle_inferior_event (ecs
);
2076 if (!ecs
->wait_some_more
)
2078 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
2080 delete_step_thread_step_resume_breakpoint ();
2082 /* We may not find an inferior if this was a process exit. */
2083 if (inf
== NULL
|| inf
->stop_soon
== NO_STOP_QUIETLY
)
2086 if (target_has_execution
2087 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2088 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
2089 && ecs
->event_thread
->step_multi
2090 && ecs
->event_thread
->stop_step
)
2091 inferior_event_handler (INF_EXEC_CONTINUE
, NULL
);
2093 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2096 /* No error, don't finish the thread states yet. */
2097 discard_cleanups (ts_old_chain
);
2099 /* Revert thread and frame. */
2100 do_cleanups (old_chain
);
2102 /* If the inferior was in sync execution mode, and now isn't,
2103 restore the prompt. */
2104 if (was_sync
&& !sync_execution
)
2105 display_gdb_prompt (0);
2108 /* Prepare an execution control state for looping through a
2109 wait_for_inferior-type loop. */
2112 init_execution_control_state (struct execution_control_state
*ecs
)
2114 ecs
->random_signal
= 0;
2117 /* Clear context switchable stepping state. */
2120 init_thread_stepping_state (struct thread_info
*tss
)
2122 struct symtab_and_line sal
;
2124 tss
->stepping_over_breakpoint
= 0;
2125 tss
->step_after_step_resume_breakpoint
= 0;
2126 tss
->stepping_through_solib_after_catch
= 0;
2127 tss
->stepping_through_solib_catchpoints
= NULL
;
2129 sal
= find_pc_line (tss
->prev_pc
, 0);
2130 tss
->current_line
= sal
.line
;
2131 tss
->current_symtab
= sal
.symtab
;
2134 /* Return the cached copy of the last pid/waitstatus returned by
2135 target_wait()/deprecated_target_wait_hook(). The data is actually
2136 cached by handle_inferior_event(), which gets called immediately
2137 after target_wait()/deprecated_target_wait_hook(). */
2140 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
2142 *ptidp
= target_last_wait_ptid
;
2143 *status
= target_last_waitstatus
;
2147 nullify_last_target_wait_ptid (void)
2149 target_last_wait_ptid
= minus_one_ptid
;
2152 /* Switch thread contexts. */
2155 context_switch (ptid_t ptid
)
2159 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
2160 target_pid_to_str (inferior_ptid
));
2161 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
2162 target_pid_to_str (ptid
));
2165 switch_to_thread (ptid
);
2169 adjust_pc_after_break (struct execution_control_state
*ecs
)
2171 struct regcache
*regcache
;
2172 struct gdbarch
*gdbarch
;
2173 CORE_ADDR breakpoint_pc
;
2175 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2176 we aren't, just return.
2178 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2179 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2180 implemented by software breakpoints should be handled through the normal
2183 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2184 different signals (SIGILL or SIGEMT for instance), but it is less
2185 clear where the PC is pointing afterwards. It may not match
2186 gdbarch_decr_pc_after_break. I don't know any specific target that
2187 generates these signals at breakpoints (the code has been in GDB since at
2188 least 1992) so I can not guess how to handle them here.
2190 In earlier versions of GDB, a target with
2191 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2192 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2193 target with both of these set in GDB history, and it seems unlikely to be
2194 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2196 if (ecs
->ws
.kind
!= TARGET_WAITKIND_STOPPED
)
2199 if (ecs
->ws
.value
.sig
!= TARGET_SIGNAL_TRAP
)
2202 /* In reverse execution, when a breakpoint is hit, the instruction
2203 under it has already been de-executed. The reported PC always
2204 points at the breakpoint address, so adjusting it further would
2205 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2208 B1 0x08000000 : INSN1
2209 B2 0x08000001 : INSN2
2211 PC -> 0x08000003 : INSN4
2213 Say you're stopped at 0x08000003 as above. Reverse continuing
2214 from that point should hit B2 as below. Reading the PC when the
2215 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2216 been de-executed already.
2218 B1 0x08000000 : INSN1
2219 B2 PC -> 0x08000001 : INSN2
2223 We can't apply the same logic as for forward execution, because
2224 we would wrongly adjust the PC to 0x08000000, since there's a
2225 breakpoint at PC - 1. We'd then report a hit on B1, although
2226 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2228 if (execution_direction
== EXEC_REVERSE
)
2231 /* If this target does not decrement the PC after breakpoints, then
2232 we have nothing to do. */
2233 regcache
= get_thread_regcache (ecs
->ptid
);
2234 gdbarch
= get_regcache_arch (regcache
);
2235 if (gdbarch_decr_pc_after_break (gdbarch
) == 0)
2238 /* Find the location where (if we've hit a breakpoint) the
2239 breakpoint would be. */
2240 breakpoint_pc
= regcache_read_pc (regcache
)
2241 - gdbarch_decr_pc_after_break (gdbarch
);
2243 /* Check whether there actually is a software breakpoint inserted at
2246 If in non-stop mode, a race condition is possible where we've
2247 removed a breakpoint, but stop events for that breakpoint were
2248 already queued and arrive later. To suppress those spurious
2249 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
2250 and retire them after a number of stop events are reported. */
2251 if (software_breakpoint_inserted_here_p (breakpoint_pc
)
2252 || (non_stop
&& moribund_breakpoint_here_p (breakpoint_pc
)))
2254 struct cleanup
*old_cleanups
= NULL
;
2256 old_cleanups
= record_gdb_operation_disable_set ();
2258 /* When using hardware single-step, a SIGTRAP is reported for both
2259 a completed single-step and a software breakpoint. Need to
2260 differentiate between the two, as the latter needs adjusting
2261 but the former does not.
2263 The SIGTRAP can be due to a completed hardware single-step only if
2264 - we didn't insert software single-step breakpoints
2265 - the thread to be examined is still the current thread
2266 - this thread is currently being stepped
2268 If any of these events did not occur, we must have stopped due
2269 to hitting a software breakpoint, and have to back up to the
2272 As a special case, we could have hardware single-stepped a
2273 software breakpoint. In this case (prev_pc == breakpoint_pc),
2274 we also need to back up to the breakpoint address. */
2276 if (singlestep_breakpoints_inserted_p
2277 || !ptid_equal (ecs
->ptid
, inferior_ptid
)
2278 || !currently_stepping (ecs
->event_thread
)
2279 || ecs
->event_thread
->prev_pc
== breakpoint_pc
)
2280 regcache_write_pc (regcache
, breakpoint_pc
);
2283 do_cleanups (old_cleanups
);
2288 init_infwait_state (void)
2290 waiton_ptid
= pid_to_ptid (-1);
2291 infwait_state
= infwait_normal_state
;
2295 error_is_running (void)
2298 Cannot execute this command while the selected thread is running."));
2302 ensure_not_running (void)
2304 if (is_running (inferior_ptid
))
2305 error_is_running ();
2308 /* Given an execution control state that has been freshly filled in
2309 by an event from the inferior, figure out what it means and take
2310 appropriate action. */
2313 handle_inferior_event (struct execution_control_state
*ecs
)
2315 int sw_single_step_trap_p
= 0;
2316 int stopped_by_watchpoint
;
2317 int stepped_after_stopped_by_watchpoint
= 0;
2318 struct symtab_and_line stop_pc_sal
;
2319 enum stop_kind stop_soon
;
2321 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2322 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
2323 && ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
)
2325 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
2327 stop_soon
= inf
->stop_soon
;
2330 stop_soon
= NO_STOP_QUIETLY
;
2332 /* Cache the last pid/waitstatus. */
2333 target_last_wait_ptid
= ecs
->ptid
;
2334 target_last_waitstatus
= ecs
->ws
;
2336 /* Always clear state belonging to the previous time we stopped. */
2337 stop_stack_dummy
= 0;
2339 /* If it's a new process, add it to the thread database */
2341 ecs
->new_thread_event
= (!ptid_equal (ecs
->ptid
, inferior_ptid
)
2342 && !ptid_equal (ecs
->ptid
, minus_one_ptid
)
2343 && !in_thread_list (ecs
->ptid
));
2345 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2346 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
&& ecs
->new_thread_event
)
2347 add_thread (ecs
->ptid
);
2349 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
2351 /* Dependent on valid ECS->EVENT_THREAD. */
2352 adjust_pc_after_break (ecs
);
2354 /* Dependent on the current PC value modified by adjust_pc_after_break. */
2355 reinit_frame_cache ();
2357 if (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
)
2359 breakpoint_retire_moribund ();
2361 /* Mark the non-executing threads accordingly. In all-stop, all
2362 threads of all processes are stopped when we get any event
2363 reported. In non-stop mode, only the event thread stops. If
2364 we're handling a process exit in non-stop mode, there's
2365 nothing to do, as threads of the dead process are gone, and
2366 threads of any other process were left running. */
2368 set_executing (minus_one_ptid
, 0);
2369 else if (ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
2370 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
)
2371 set_executing (inferior_ptid
, 0);
2374 switch (infwait_state
)
2376 case infwait_thread_hop_state
:
2378 fprintf_unfiltered (gdb_stdlog
, "infrun: infwait_thread_hop_state\n");
2379 /* Cancel the waiton_ptid. */
2380 waiton_ptid
= pid_to_ptid (-1);
2383 case infwait_normal_state
:
2385 fprintf_unfiltered (gdb_stdlog
, "infrun: infwait_normal_state\n");
2388 case infwait_step_watch_state
:
2390 fprintf_unfiltered (gdb_stdlog
,
2391 "infrun: infwait_step_watch_state\n");
2393 stepped_after_stopped_by_watchpoint
= 1;
2396 case infwait_nonstep_watch_state
:
2398 fprintf_unfiltered (gdb_stdlog
,
2399 "infrun: infwait_nonstep_watch_state\n");
2400 insert_breakpoints ();
2402 /* FIXME-maybe: is this cleaner than setting a flag? Does it
2403 handle things like signals arriving and other things happening
2404 in combination correctly? */
2405 stepped_after_stopped_by_watchpoint
= 1;
2409 internal_error (__FILE__
, __LINE__
, _("bad switch"));
2411 infwait_state
= infwait_normal_state
;
2413 switch (ecs
->ws
.kind
)
2415 case TARGET_WAITKIND_LOADED
:
2417 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
2418 /* Ignore gracefully during startup of the inferior, as it might
2419 be the shell which has just loaded some objects, otherwise
2420 add the symbols for the newly loaded objects. Also ignore at
2421 the beginning of an attach or remote session; we will query
2422 the full list of libraries once the connection is
2424 if (stop_soon
== NO_STOP_QUIETLY
)
2426 /* Check for any newly added shared libraries if we're
2427 supposed to be adding them automatically. Switch
2428 terminal for any messages produced by
2429 breakpoint_re_set. */
2430 target_terminal_ours_for_output ();
2431 /* NOTE: cagney/2003-11-25: Make certain that the target
2432 stack's section table is kept up-to-date. Architectures,
2433 (e.g., PPC64), use the section table to perform
2434 operations such as address => section name and hence
2435 require the table to contain all sections (including
2436 those found in shared libraries). */
2437 /* NOTE: cagney/2003-11-25: Pass current_target and not
2438 exec_ops to SOLIB_ADD. This is because current GDB is
2439 only tooled to propagate section_table changes out from
2440 the "current_target" (see target_resize_to_sections), and
2441 not up from the exec stratum. This, of course, isn't
2442 right. "infrun.c" should only interact with the
2443 exec/process stratum, instead relying on the target stack
2444 to propagate relevant changes (stop, section table
2445 changed, ...) up to other layers. */
2447 SOLIB_ADD (NULL
, 0, ¤t_target
, auto_solib_add
);
2449 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
2451 target_terminal_inferior ();
2453 /* If requested, stop when the dynamic linker notifies
2454 gdb of events. This allows the user to get control
2455 and place breakpoints in initializer routines for
2456 dynamically loaded objects (among other things). */
2457 if (stop_on_solib_events
)
2459 stop_stepping (ecs
);
2463 /* NOTE drow/2007-05-11: This might be a good place to check
2464 for "catch load". */
2467 /* If we are skipping through a shell, or through shared library
2468 loading that we aren't interested in, resume the program. If
2469 we're running the program normally, also resume. But stop if
2470 we're attaching or setting up a remote connection. */
2471 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
2473 /* Loading of shared libraries might have changed breakpoint
2474 addresses. Make sure new breakpoints are inserted. */
2475 if (stop_soon
== NO_STOP_QUIETLY
2476 && !breakpoints_always_inserted_mode ())
2477 insert_breakpoints ();
2478 resume (0, TARGET_SIGNAL_0
);
2479 prepare_to_wait (ecs
);
2485 case TARGET_WAITKIND_SPURIOUS
:
2487 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
2488 resume (0, TARGET_SIGNAL_0
);
2489 prepare_to_wait (ecs
);
2492 case TARGET_WAITKIND_EXITED
:
2494 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXITED\n");
2495 inferior_ptid
= ecs
->ptid
;
2496 target_terminal_ours (); /* Must do this before mourn anyway */
2497 print_stop_reason (EXITED
, ecs
->ws
.value
.integer
);
2499 /* Record the exit code in the convenience variable $_exitcode, so
2500 that the user can inspect this again later. */
2501 set_internalvar (lookup_internalvar ("_exitcode"),
2502 value_from_longest (builtin_type_int32
,
2503 (LONGEST
) ecs
->ws
.value
.integer
));
2504 gdb_flush (gdb_stdout
);
2505 target_mourn_inferior ();
2506 singlestep_breakpoints_inserted_p
= 0;
2507 stop_print_frame
= 0;
2508 stop_stepping (ecs
);
2511 case TARGET_WAITKIND_SIGNALLED
:
2513 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SIGNALLED\n");
2514 inferior_ptid
= ecs
->ptid
;
2515 stop_print_frame
= 0;
2516 target_terminal_ours (); /* Must do this before mourn anyway */
2518 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't
2519 reach here unless the inferior is dead. However, for years
2520 target_kill() was called here, which hints that fatal signals aren't
2521 really fatal on some systems. If that's true, then some changes
2523 target_mourn_inferior ();
2525 print_stop_reason (SIGNAL_EXITED
, ecs
->ws
.value
.sig
);
2526 singlestep_breakpoints_inserted_p
= 0;
2527 stop_stepping (ecs
);
2530 /* The following are the only cases in which we keep going;
2531 the above cases end in a continue or goto. */
2532 case TARGET_WAITKIND_FORKED
:
2533 case TARGET_WAITKIND_VFORKED
:
2535 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
2537 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
2539 context_switch (ecs
->ptid
);
2540 reinit_frame_cache ();
2543 /* Immediately detach breakpoints from the child before there's
2544 any chance of letting the user delete breakpoints from the
2545 breakpoint lists. If we don't do this early, it's easy to
2546 leave left over traps in the child, vis: "break foo; catch
2547 fork; c; <fork>; del; c; <child calls foo>". We only follow
2548 the fork on the last `continue', and by that time the
2549 breakpoint at "foo" is long gone from the breakpoint table.
2550 If we vforked, then we don't need to unpatch here, since both
2551 parent and child are sharing the same memory pages; we'll
2552 need to unpatch at follow/detach time instead to be certain
2553 that new breakpoints added between catchpoint hit time and
2554 vfork follow are detached. */
2555 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
2557 int child_pid
= ptid_get_pid (ecs
->ws
.value
.related_pid
);
2559 /* This won't actually modify the breakpoint list, but will
2560 physically remove the breakpoints from the child. */
2561 detach_breakpoints (child_pid
);
2564 /* In case the event is caught by a catchpoint, remember that
2565 the event is to be followed at the next resume of the thread,
2566 and not immediately. */
2567 ecs
->event_thread
->pending_follow
= ecs
->ws
;
2569 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
2571 ecs
->event_thread
->stop_bpstat
= bpstat_stop_status (stop_pc
, ecs
->ptid
);
2573 ecs
->random_signal
= !bpstat_explains_signal (ecs
->event_thread
->stop_bpstat
);
2575 /* If no catchpoint triggered for this, then keep going. */
2576 if (ecs
->random_signal
)
2580 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
2582 should_resume
= follow_fork ();
2584 ecs
->event_thread
= inferior_thread ();
2585 ecs
->ptid
= inferior_ptid
;
2590 stop_stepping (ecs
);
2593 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_TRAP
;
2594 goto process_event_stop_test
;
2596 case TARGET_WAITKIND_EXECD
:
2598 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
2600 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
2602 context_switch (ecs
->ptid
);
2603 reinit_frame_cache ();
2606 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
2608 /* This causes the eventpoints and symbol table to be reset.
2609 Must do this now, before trying to determine whether to
2611 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
2613 ecs
->event_thread
->stop_bpstat
= bpstat_stop_status (stop_pc
, ecs
->ptid
);
2614 ecs
->random_signal
= !bpstat_explains_signal (ecs
->event_thread
->stop_bpstat
);
2616 /* Note that this may be referenced from inside
2617 bpstat_stop_status above, through inferior_has_execd. */
2618 xfree (ecs
->ws
.value
.execd_pathname
);
2619 ecs
->ws
.value
.execd_pathname
= NULL
;
2621 /* If no catchpoint triggered for this, then keep going. */
2622 if (ecs
->random_signal
)
2624 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
2628 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_TRAP
;
2629 goto process_event_stop_test
;
2631 /* Be careful not to try to gather much state about a thread
2632 that's in a syscall. It's frequently a losing proposition. */
2633 case TARGET_WAITKIND_SYSCALL_ENTRY
:
2635 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
2636 resume (0, TARGET_SIGNAL_0
);
2637 prepare_to_wait (ecs
);
2640 /* Before examining the threads further, step this thread to
2641 get it entirely out of the syscall. (We get notice of the
2642 event when the thread is just on the verge of exiting a
2643 syscall. Stepping one instruction seems to get it back
2645 case TARGET_WAITKIND_SYSCALL_RETURN
:
2647 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
2648 target_resume (ecs
->ptid
, 1, TARGET_SIGNAL_0
);
2649 prepare_to_wait (ecs
);
2652 case TARGET_WAITKIND_STOPPED
:
2654 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
2655 ecs
->event_thread
->stop_signal
= ecs
->ws
.value
.sig
;
2658 case TARGET_WAITKIND_NO_HISTORY
:
2659 /* Reverse execution: target ran out of history info. */
2660 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
2661 print_stop_reason (NO_HISTORY
, 0);
2662 stop_stepping (ecs
);
2665 /* We had an event in the inferior, but we are not interested
2666 in handling it at this level. The lower layers have already
2667 done what needs to be done, if anything.
2669 One of the possible circumstances for this is when the
2670 inferior produces output for the console. The inferior has
2671 not stopped, and we are ignoring the event. Another possible
2672 circumstance is any event which the lower level knows will be
2673 reported multiple times without an intervening resume. */
2674 case TARGET_WAITKIND_IGNORE
:
2676 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
2677 prepare_to_wait (ecs
);
2681 if (ecs
->new_thread_event
)
2684 /* Non-stop assumes that the target handles adding new threads
2685 to the thread list. */
2686 internal_error (__FILE__
, __LINE__
, "\
2687 targets should add new threads to the thread list themselves in non-stop mode.");
2689 /* We may want to consider not doing a resume here in order to
2690 give the user a chance to play with the new thread. It might
2691 be good to make that a user-settable option. */
2693 /* At this point, all threads are stopped (happens automatically
2694 in either the OS or the native code). Therefore we need to
2695 continue all threads in order to make progress. */
2697 target_resume (RESUME_ALL
, 0, TARGET_SIGNAL_0
);
2698 prepare_to_wait (ecs
);
2702 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
)
2704 /* Do we need to clean up the state of a thread that has
2705 completed a displaced single-step? (Doing so usually affects
2706 the PC, so do it here, before we set stop_pc.) */
2707 displaced_step_fixup (ecs
->ptid
, ecs
->event_thread
->stop_signal
);
2709 /* If we either finished a single-step or hit a breakpoint, but
2710 the user wanted this thread to be stopped, pretend we got a
2711 SIG0 (generic unsignaled stop). */
2713 if (ecs
->event_thread
->stop_requested
2714 && ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
2715 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
2718 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
2722 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = 0x%s\n",
2723 paddr_nz (stop_pc
));
2724 if (target_stopped_by_watchpoint ())
2727 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
2729 if (target_stopped_data_address (¤t_target
, &addr
))
2730 fprintf_unfiltered (gdb_stdlog
,
2731 "infrun: stopped data address = 0x%s\n",
2734 fprintf_unfiltered (gdb_stdlog
,
2735 "infrun: (no data address available)\n");
2739 if (stepping_past_singlestep_breakpoint
)
2741 gdb_assert (singlestep_breakpoints_inserted_p
);
2742 gdb_assert (ptid_equal (singlestep_ptid
, ecs
->ptid
));
2743 gdb_assert (!ptid_equal (singlestep_ptid
, saved_singlestep_ptid
));
2745 stepping_past_singlestep_breakpoint
= 0;
2747 /* We've either finished single-stepping past the single-step
2748 breakpoint, or stopped for some other reason. It would be nice if
2749 we could tell, but we can't reliably. */
2750 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
2753 fprintf_unfiltered (gdb_stdlog
, "infrun: stepping_past_singlestep_breakpoint\n");
2754 /* Pull the single step breakpoints out of the target. */
2755 remove_single_step_breakpoints ();
2756 singlestep_breakpoints_inserted_p
= 0;
2758 ecs
->random_signal
= 0;
2760 context_switch (saved_singlestep_ptid
);
2761 if (deprecated_context_hook
)
2762 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
2764 resume (1, TARGET_SIGNAL_0
);
2765 prepare_to_wait (ecs
);
2770 if (!ptid_equal (deferred_step_ptid
, null_ptid
))
2772 /* In non-stop mode, there's never a deferred_step_ptid set. */
2773 gdb_assert (!non_stop
);
2775 /* If we stopped for some other reason than single-stepping, ignore
2776 the fact that we were supposed to switch back. */
2777 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
2780 fprintf_unfiltered (gdb_stdlog
,
2781 "infrun: handling deferred step\n");
2783 /* Pull the single step breakpoints out of the target. */
2784 if (singlestep_breakpoints_inserted_p
)
2786 remove_single_step_breakpoints ();
2787 singlestep_breakpoints_inserted_p
= 0;
2790 /* Note: We do not call context_switch at this point, as the
2791 context is already set up for stepping the original thread. */
2792 switch_to_thread (deferred_step_ptid
);
2793 deferred_step_ptid
= null_ptid
;
2794 /* Suppress spurious "Switching to ..." message. */
2795 previous_inferior_ptid
= inferior_ptid
;
2797 resume (1, TARGET_SIGNAL_0
);
2798 prepare_to_wait (ecs
);
2802 deferred_step_ptid
= null_ptid
;
2805 /* See if a thread hit a thread-specific breakpoint that was meant for
2806 another thread. If so, then step that thread past the breakpoint,
2809 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
2811 int thread_hop_needed
= 0;
2813 /* Check if a regular breakpoint has been hit before checking
2814 for a potential single step breakpoint. Otherwise, GDB will
2815 not see this breakpoint hit when stepping onto breakpoints. */
2816 if (regular_breakpoint_inserted_here_p (stop_pc
))
2818 ecs
->random_signal
= 0;
2819 if (!breakpoint_thread_match (stop_pc
, ecs
->ptid
))
2820 thread_hop_needed
= 1;
2822 else if (singlestep_breakpoints_inserted_p
)
2824 /* We have not context switched yet, so this should be true
2825 no matter which thread hit the singlestep breakpoint. */
2826 gdb_assert (ptid_equal (inferior_ptid
, singlestep_ptid
));
2828 fprintf_unfiltered (gdb_stdlog
, "infrun: software single step "
2830 target_pid_to_str (ecs
->ptid
));
2832 ecs
->random_signal
= 0;
2833 /* The call to in_thread_list is necessary because PTIDs sometimes
2834 change when we go from single-threaded to multi-threaded. If
2835 the singlestep_ptid is still in the list, assume that it is
2836 really different from ecs->ptid. */
2837 if (!ptid_equal (singlestep_ptid
, ecs
->ptid
)
2838 && in_thread_list (singlestep_ptid
))
2840 /* If the PC of the thread we were trying to single-step
2841 has changed, discard this event (which we were going
2842 to ignore anyway), and pretend we saw that thread
2843 trap. This prevents us continuously moving the
2844 single-step breakpoint forward, one instruction at a
2845 time. If the PC has changed, then the thread we were
2846 trying to single-step has trapped or been signalled,
2847 but the event has not been reported to GDB yet.
2849 There might be some cases where this loses signal
2850 information, if a signal has arrived at exactly the
2851 same time that the PC changed, but this is the best
2852 we can do with the information available. Perhaps we
2853 should arrange to report all events for all threads
2854 when they stop, or to re-poll the remote looking for
2855 this particular thread (i.e. temporarily enable
2858 CORE_ADDR new_singlestep_pc
2859 = regcache_read_pc (get_thread_regcache (singlestep_ptid
));
2861 if (new_singlestep_pc
!= singlestep_pc
)
2863 enum target_signal stop_signal
;
2866 fprintf_unfiltered (gdb_stdlog
, "infrun: unexpected thread,"
2867 " but expected thread advanced also\n");
2869 /* The current context still belongs to
2870 singlestep_ptid. Don't swap here, since that's
2871 the context we want to use. Just fudge our
2872 state and continue. */
2873 stop_signal
= ecs
->event_thread
->stop_signal
;
2874 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
2875 ecs
->ptid
= singlestep_ptid
;
2876 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
2877 ecs
->event_thread
->stop_signal
= stop_signal
;
2878 stop_pc
= new_singlestep_pc
;
2883 fprintf_unfiltered (gdb_stdlog
,
2884 "infrun: unexpected thread\n");
2886 thread_hop_needed
= 1;
2887 stepping_past_singlestep_breakpoint
= 1;
2888 saved_singlestep_ptid
= singlestep_ptid
;
2893 if (thread_hop_needed
)
2895 int remove_status
= 0;
2898 fprintf_unfiltered (gdb_stdlog
, "infrun: thread_hop_needed\n");
2900 /* Switch context before touching inferior memory, the
2901 previous thread may have exited. */
2902 if (!ptid_equal (inferior_ptid
, ecs
->ptid
))
2903 context_switch (ecs
->ptid
);
2905 /* Saw a breakpoint, but it was hit by the wrong thread.
2908 if (singlestep_breakpoints_inserted_p
)
2910 /* Pull the single step breakpoints out of the target. */
2911 remove_single_step_breakpoints ();
2912 singlestep_breakpoints_inserted_p
= 0;
2915 /* If the arch can displace step, don't remove the
2917 if (!use_displaced_stepping (current_gdbarch
))
2918 remove_status
= remove_breakpoints ();
2920 /* Did we fail to remove breakpoints? If so, try
2921 to set the PC past the bp. (There's at least
2922 one situation in which we can fail to remove
2923 the bp's: On HP-UX's that use ttrace, we can't
2924 change the address space of a vforking child
2925 process until the child exits (well, okay, not
2926 then either :-) or execs. */
2927 if (remove_status
!= 0)
2928 error (_("Cannot step over breakpoint hit in wrong thread"));
2933 /* Only need to require the next event from this
2934 thread in all-stop mode. */
2935 waiton_ptid
= ecs
->ptid
;
2936 infwait_state
= infwait_thread_hop_state
;
2939 ecs
->event_thread
->stepping_over_breakpoint
= 1;
2941 registers_changed ();
2945 else if (singlestep_breakpoints_inserted_p
)
2947 sw_single_step_trap_p
= 1;
2948 ecs
->random_signal
= 0;
2952 ecs
->random_signal
= 1;
2954 /* See if something interesting happened to the non-current thread. If
2955 so, then switch to that thread. */
2956 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
2959 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
2961 context_switch (ecs
->ptid
);
2963 if (deprecated_context_hook
)
2964 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
2967 if (singlestep_breakpoints_inserted_p
)
2969 /* Pull the single step breakpoints out of the target. */
2970 remove_single_step_breakpoints ();
2971 singlestep_breakpoints_inserted_p
= 0;
2974 if (stepped_after_stopped_by_watchpoint
)
2975 stopped_by_watchpoint
= 0;
2977 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
2979 /* If necessary, step over this watchpoint. We'll be back to display
2981 if (stopped_by_watchpoint
2982 && (target_have_steppable_watchpoint
2983 || gdbarch_have_nonsteppable_watchpoint (current_gdbarch
)))
2985 /* At this point, we are stopped at an instruction which has
2986 attempted to write to a piece of memory under control of
2987 a watchpoint. The instruction hasn't actually executed
2988 yet. If we were to evaluate the watchpoint expression
2989 now, we would get the old value, and therefore no change
2990 would seem to have occurred.
2992 In order to make watchpoints work `right', we really need
2993 to complete the memory write, and then evaluate the
2994 watchpoint expression. We do this by single-stepping the
2997 It may not be necessary to disable the watchpoint to stop over
2998 it. For example, the PA can (with some kernel cooperation)
2999 single step over a watchpoint without disabling the watchpoint.
3001 It is far more common to need to disable a watchpoint to step
3002 the inferior over it. If we have non-steppable watchpoints,
3003 we must disable the current watchpoint; it's simplest to
3004 disable all watchpoints and breakpoints. */
3007 if (!target_have_steppable_watchpoint
)
3008 remove_breakpoints ();
3010 hw_step
= maybe_software_singlestep (current_gdbarch
, stop_pc
);
3011 target_resume (ecs
->ptid
, hw_step
, TARGET_SIGNAL_0
);
3012 registers_changed ();
3013 waiton_ptid
= ecs
->ptid
;
3014 if (target_have_steppable_watchpoint
)
3015 infwait_state
= infwait_step_watch_state
;
3017 infwait_state
= infwait_nonstep_watch_state
;
3018 prepare_to_wait (ecs
);
3022 ecs
->stop_func_start
= 0;
3023 ecs
->stop_func_end
= 0;
3024 ecs
->stop_func_name
= 0;
3025 /* Don't care about return value; stop_func_start and stop_func_name
3026 will both be 0 if it doesn't work. */
3027 find_pc_partial_function (stop_pc
, &ecs
->stop_func_name
,
3028 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
3029 ecs
->stop_func_start
3030 += gdbarch_deprecated_function_start_offset (current_gdbarch
);
3031 ecs
->event_thread
->stepping_over_breakpoint
= 0;
3032 bpstat_clear (&ecs
->event_thread
->stop_bpstat
);
3033 ecs
->event_thread
->stop_step
= 0;
3034 stop_print_frame
= 1;
3035 ecs
->random_signal
= 0;
3036 stopped_by_random_signal
= 0;
3038 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
3039 && ecs
->event_thread
->trap_expected
3040 && gdbarch_single_step_through_delay_p (current_gdbarch
)
3041 && currently_stepping (ecs
->event_thread
))
3043 /* We're trying to step off a breakpoint. Turns out that we're
3044 also on an instruction that needs to be stepped multiple
3045 times before it's been fully executing. E.g., architectures
3046 with a delay slot. It needs to be stepped twice, once for
3047 the instruction and once for the delay slot. */
3048 int step_through_delay
3049 = gdbarch_single_step_through_delay (current_gdbarch
,
3050 get_current_frame ());
3051 if (debug_infrun
&& step_through_delay
)
3052 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
3053 if (ecs
->event_thread
->step_range_end
== 0 && step_through_delay
)
3055 /* The user issued a continue when stopped at a breakpoint.
3056 Set up for another trap and get out of here. */
3057 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3061 else if (step_through_delay
)
3063 /* The user issued a step when stopped at a breakpoint.
3064 Maybe we should stop, maybe we should not - the delay
3065 slot *might* correspond to a line of source. In any
3066 case, don't decide that here, just set
3067 ecs->stepping_over_breakpoint, making sure we
3068 single-step again before breakpoints are re-inserted. */
3069 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3073 /* Look at the cause of the stop, and decide what to do.
3074 The alternatives are:
3075 1) stop_stepping and return; to really stop and return to the debugger,
3076 2) keep_going and return to start up again
3077 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
3078 3) set ecs->random_signal to 1, and the decision between 1 and 2
3079 will be made according to the signal handling tables. */
3081 /* First, distinguish signals caused by the debugger from signals
3082 that have to do with the program's own actions. Note that
3083 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3084 on the operating system version. Here we detect when a SIGILL or
3085 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3086 something similar for SIGSEGV, since a SIGSEGV will be generated
3087 when we're trying to execute a breakpoint instruction on a
3088 non-executable stack. This happens for call dummy breakpoints
3089 for architectures like SPARC that place call dummies on the
3092 If we're doing a displaced step past a breakpoint, then the
3093 breakpoint is always inserted at the original instruction;
3094 non-standard signals can't be explained by the breakpoint. */
3095 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
3096 || (! ecs
->event_thread
->trap_expected
3097 && breakpoint_inserted_here_p (stop_pc
)
3098 && (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_ILL
3099 || ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_SEGV
3100 || ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_EMT
))
3101 || stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_NO_SIGSTOP
3102 || stop_soon
== STOP_QUIETLY_REMOTE
)
3104 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
&& stop_after_trap
)
3107 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
3108 stop_print_frame
= 0;
3109 stop_stepping (ecs
);
3113 /* This is originated from start_remote(), start_inferior() and
3114 shared libraries hook functions. */
3115 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
3118 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
3119 stop_stepping (ecs
);
3123 /* This originates from attach_command(). We need to overwrite
3124 the stop_signal here, because some kernels don't ignore a
3125 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
3126 See more comments in inferior.h. On the other hand, if we
3127 get a non-SIGSTOP, report it to the user - assume the backend
3128 will handle the SIGSTOP if it should show up later.
3130 Also consider that the attach is complete when we see a
3131 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
3132 target extended-remote report it instead of a SIGSTOP
3133 (e.g. gdbserver). We already rely on SIGTRAP being our
3134 signal, so this is no exception.
3136 Also consider that the attach is complete when we see a
3137 TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell
3138 the target to stop all threads of the inferior, in case the
3139 low level attach operation doesn't stop them implicitly. If
3140 they weren't stopped implicitly, then the stub will report a
3141 TARGET_SIGNAL_0, meaning: stopped for no particular reason
3142 other than GDB's request. */
3143 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
3144 && (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_STOP
3145 || ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
3146 || ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_0
))
3148 stop_stepping (ecs
);
3149 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
3153 /* See if there is a breakpoint at the current PC. */
3154 ecs
->event_thread
->stop_bpstat
= bpstat_stop_status (stop_pc
, ecs
->ptid
);
3156 /* Following in case break condition called a
3158 stop_print_frame
= 1;
3160 /* NOTE: cagney/2003-03-29: These two checks for a random signal
3161 at one stage in the past included checks for an inferior
3162 function call's call dummy's return breakpoint. The original
3163 comment, that went with the test, read:
3165 ``End of a stack dummy. Some systems (e.g. Sony news) give
3166 another signal besides SIGTRAP, so check here as well as
3169 If someone ever tries to get call dummys on a
3170 non-executable stack to work (where the target would stop
3171 with something like a SIGSEGV), then those tests might need
3172 to be re-instated. Given, however, that the tests were only
3173 enabled when momentary breakpoints were not being used, I
3174 suspect that it won't be the case.
3176 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
3177 be necessary for call dummies on a non-executable stack on
3180 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
3182 = !(bpstat_explains_signal (ecs
->event_thread
->stop_bpstat
)
3183 || ecs
->event_thread
->trap_expected
3184 || (ecs
->event_thread
->step_range_end
3185 && ecs
->event_thread
->step_resume_breakpoint
== NULL
));
3188 ecs
->random_signal
= !bpstat_explains_signal (ecs
->event_thread
->stop_bpstat
);
3189 if (!ecs
->random_signal
)
3190 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_TRAP
;
3194 /* When we reach this point, we've pretty much decided
3195 that the reason for stopping must've been a random
3196 (unexpected) signal. */
3199 ecs
->random_signal
= 1;
3201 process_event_stop_test
:
3202 /* For the program's own signals, act according to
3203 the signal handling tables. */
3205 if (ecs
->random_signal
)
3207 /* Signal not for debugging purposes. */
3211 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal %d\n",
3212 ecs
->event_thread
->stop_signal
);
3214 stopped_by_random_signal
= 1;
3216 if (signal_print
[ecs
->event_thread
->stop_signal
])
3219 target_terminal_ours_for_output ();
3220 print_stop_reason (SIGNAL_RECEIVED
, ecs
->event_thread
->stop_signal
);
3222 /* Always stop on signals if we're either just gaining control
3223 of the program, or the user explicitly requested this thread
3224 to remain stopped. */
3225 if (stop_soon
!= NO_STOP_QUIETLY
3226 || ecs
->event_thread
->stop_requested
3227 || signal_stop_state (ecs
->event_thread
->stop_signal
))
3229 stop_stepping (ecs
);
3232 /* If not going to stop, give terminal back
3233 if we took it away. */
3235 target_terminal_inferior ();
3237 /* Clear the signal if it should not be passed. */
3238 if (signal_program
[ecs
->event_thread
->stop_signal
] == 0)
3239 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
3241 if (ecs
->event_thread
->prev_pc
== stop_pc
3242 && ecs
->event_thread
->trap_expected
3243 && ecs
->event_thread
->step_resume_breakpoint
== NULL
)
3245 /* We were just starting a new sequence, attempting to
3246 single-step off of a breakpoint and expecting a SIGTRAP.
3247 Instead this signal arrives. This signal will take us out
3248 of the stepping range so GDB needs to remember to, when
3249 the signal handler returns, resume stepping off that
3251 /* To simplify things, "continue" is forced to use the same
3252 code paths as single-step - set a breakpoint at the
3253 signal return address and then, once hit, step off that
3256 fprintf_unfiltered (gdb_stdlog
,
3257 "infrun: signal arrived while stepping over "
3260 insert_step_resume_breakpoint_at_frame (get_current_frame ());
3261 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
3266 if (ecs
->event_thread
->step_range_end
!= 0
3267 && ecs
->event_thread
->stop_signal
!= TARGET_SIGNAL_0
3268 && (ecs
->event_thread
->step_range_start
<= stop_pc
3269 && stop_pc
< ecs
->event_thread
->step_range_end
)
3270 && frame_id_eq (get_frame_id (get_current_frame ()),
3271 ecs
->event_thread
->step_frame_id
)
3272 && ecs
->event_thread
->step_resume_breakpoint
== NULL
)
3274 /* The inferior is about to take a signal that will take it
3275 out of the single step range. Set a breakpoint at the
3276 current PC (which is presumably where the signal handler
3277 will eventually return) and then allow the inferior to
3280 Note that this is only needed for a signal delivered
3281 while in the single-step range. Nested signals aren't a
3282 problem as they eventually all return. */
3284 fprintf_unfiltered (gdb_stdlog
,
3285 "infrun: signal may take us out of "
3286 "single-step range\n");
3288 insert_step_resume_breakpoint_at_frame (get_current_frame ());
3293 /* Note: step_resume_breakpoint may be non-NULL. This occures
3294 when either there's a nested signal, or when there's a
3295 pending signal enabled just as the signal handler returns
3296 (leaving the inferior at the step-resume-breakpoint without
3297 actually executing it). Either way continue until the
3298 breakpoint is really hit. */
3303 /* Handle cases caused by hitting a breakpoint. */
3305 CORE_ADDR jmp_buf_pc
;
3306 struct bpstat_what what
;
3308 what
= bpstat_what (ecs
->event_thread
->stop_bpstat
);
3310 if (what
.call_dummy
)
3312 stop_stack_dummy
= 1;
3315 switch (what
.main_action
)
3317 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
3318 /* If we hit the breakpoint at longjmp while stepping, we
3319 install a momentary breakpoint at the target of the
3323 fprintf_unfiltered (gdb_stdlog
,
3324 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
3326 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3328 if (!gdbarch_get_longjmp_target_p (current_gdbarch
)
3329 || !gdbarch_get_longjmp_target (current_gdbarch
,
3330 get_current_frame (), &jmp_buf_pc
))
3333 fprintf_unfiltered (gdb_stdlog
, "\
3334 infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME (!gdbarch_get_longjmp_target)\n");
3339 /* We're going to replace the current step-resume breakpoint
3340 with a longjmp-resume breakpoint. */
3341 delete_step_resume_breakpoint (ecs
->event_thread
);
3343 /* Insert a breakpoint at resume address. */
3344 insert_longjmp_resume_breakpoint (jmp_buf_pc
);
3349 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
3351 fprintf_unfiltered (gdb_stdlog
,
3352 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
3354 gdb_assert (ecs
->event_thread
->step_resume_breakpoint
!= NULL
);
3355 delete_step_resume_breakpoint (ecs
->event_thread
);
3357 ecs
->event_thread
->stop_step
= 1;
3358 print_stop_reason (END_STEPPING_RANGE
, 0);
3359 stop_stepping (ecs
);
3362 case BPSTAT_WHAT_SINGLE
:
3364 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
3365 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3366 /* Still need to check other stuff, at least the case
3367 where we are stepping and step out of the right range. */
3370 case BPSTAT_WHAT_STOP_NOISY
:
3372 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
3373 stop_print_frame
= 1;
3375 /* We are about to nuke the step_resume_breakpointt via the
3376 cleanup chain, so no need to worry about it here. */
3378 stop_stepping (ecs
);
3381 case BPSTAT_WHAT_STOP_SILENT
:
3383 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
3384 stop_print_frame
= 0;
3386 /* We are about to nuke the step_resume_breakpoin via the
3387 cleanup chain, so no need to worry about it here. */
3389 stop_stepping (ecs
);
3392 case BPSTAT_WHAT_STEP_RESUME
:
3394 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
3396 delete_step_resume_breakpoint (ecs
->event_thread
);
3397 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
3399 /* Back when the step-resume breakpoint was inserted, we
3400 were trying to single-step off a breakpoint. Go back
3402 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
3403 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3407 if (stop_pc
== ecs
->stop_func_start
3408 && execution_direction
== EXEC_REVERSE
)
3410 /* We are stepping over a function call in reverse, and
3411 just hit the step-resume breakpoint at the start
3412 address of the function. Go back to single-stepping,
3413 which should take us back to the function call. */
3414 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3420 case BPSTAT_WHAT_CHECK_SHLIBS
:
3423 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_CHECK_SHLIBS\n");
3425 /* Check for any newly added shared libraries if we're
3426 supposed to be adding them automatically. Switch
3427 terminal for any messages produced by
3428 breakpoint_re_set. */
3429 target_terminal_ours_for_output ();
3430 /* NOTE: cagney/2003-11-25: Make certain that the target
3431 stack's section table is kept up-to-date. Architectures,
3432 (e.g., PPC64), use the section table to perform
3433 operations such as address => section name and hence
3434 require the table to contain all sections (including
3435 those found in shared libraries). */
3436 /* NOTE: cagney/2003-11-25: Pass current_target and not
3437 exec_ops to SOLIB_ADD. This is because current GDB is
3438 only tooled to propagate section_table changes out from
3439 the "current_target" (see target_resize_to_sections), and
3440 not up from the exec stratum. This, of course, isn't
3441 right. "infrun.c" should only interact with the
3442 exec/process stratum, instead relying on the target stack
3443 to propagate relevant changes (stop, section table
3444 changed, ...) up to other layers. */
3446 SOLIB_ADD (NULL
, 0, ¤t_target
, auto_solib_add
);
3448 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
3450 target_terminal_inferior ();
3452 /* If requested, stop when the dynamic linker notifies
3453 gdb of events. This allows the user to get control
3454 and place breakpoints in initializer routines for
3455 dynamically loaded objects (among other things). */
3456 if (stop_on_solib_events
|| stop_stack_dummy
)
3458 stop_stepping (ecs
);
3463 /* We want to step over this breakpoint, then keep going. */
3464 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3470 case BPSTAT_WHAT_LAST
:
3471 /* Not a real code, but listed here to shut up gcc -Wall. */
3473 case BPSTAT_WHAT_KEEP_CHECKING
:
3478 /* We come here if we hit a breakpoint but should not
3479 stop for it. Possibly we also were stepping
3480 and should stop for that. So fall through and
3481 test for stepping. But, if not stepping,
3484 /* In all-stop mode, if we're currently stepping but have stopped in
3485 some other thread, we need to switch back to the stepped thread. */
3488 struct thread_info
*tp
;
3489 tp
= iterate_over_threads (currently_stepping_or_nexting_callback
,
3493 /* However, if the current thread is blocked on some internal
3494 breakpoint, and we simply need to step over that breakpoint
3495 to get it going again, do that first. */
3496 if ((ecs
->event_thread
->trap_expected
3497 && ecs
->event_thread
->stop_signal
!= TARGET_SIGNAL_TRAP
)
3498 || ecs
->event_thread
->stepping_over_breakpoint
)
3504 /* If the stepping thread exited, then don't try reverting
3505 back to it, just keep going. We need to query the target
3506 in case it doesn't support thread exit events. */
3507 if (is_exited (tp
->ptid
)
3508 || !target_thread_alive (tp
->ptid
))
3511 fprintf_unfiltered (gdb_stdlog
, "\
3512 infrun: not switching back to stepped thread, it has vanished\n");
3514 delete_thread (tp
->ptid
);
3519 /* Otherwise, we no longer expect a trap in the current thread.
3520 Clear the trap_expected flag before switching back -- this is
3521 what keep_going would do as well, if we called it. */
3522 ecs
->event_thread
->trap_expected
= 0;
3525 fprintf_unfiltered (gdb_stdlog
,
3526 "infrun: switching back to stepped thread\n");
3528 ecs
->event_thread
= tp
;
3529 ecs
->ptid
= tp
->ptid
;
3530 context_switch (ecs
->ptid
);
3536 /* Are we stepping to get the inferior out of the dynamic linker's
3537 hook (and possibly the dld itself) after catching a shlib
3539 if (ecs
->event_thread
->stepping_through_solib_after_catch
)
3541 #if defined(SOLIB_ADD)
3542 /* Have we reached our destination? If not, keep going. */
3543 if (SOLIB_IN_DYNAMIC_LINKER (PIDGET (ecs
->ptid
), stop_pc
))
3546 fprintf_unfiltered (gdb_stdlog
, "infrun: stepping in dynamic linker\n");
3547 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3553 fprintf_unfiltered (gdb_stdlog
, "infrun: step past dynamic linker\n");
3554 /* Else, stop and report the catchpoint(s) whose triggering
3555 caused us to begin stepping. */
3556 ecs
->event_thread
->stepping_through_solib_after_catch
= 0;
3557 bpstat_clear (&ecs
->event_thread
->stop_bpstat
);
3558 ecs
->event_thread
->stop_bpstat
3559 = bpstat_copy (ecs
->event_thread
->stepping_through_solib_catchpoints
);
3560 bpstat_clear (&ecs
->event_thread
->stepping_through_solib_catchpoints
);
3561 stop_print_frame
= 1;
3562 stop_stepping (ecs
);
3566 if (ecs
->event_thread
->step_resume_breakpoint
)
3569 fprintf_unfiltered (gdb_stdlog
,
3570 "infrun: step-resume breakpoint is inserted\n");
3572 /* Having a step-resume breakpoint overrides anything
3573 else having to do with stepping commands until
3574 that breakpoint is reached. */
3579 if (ecs
->event_thread
->step_range_end
== 0)
3582 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
3583 /* Likewise if we aren't even stepping. */
3588 /* If stepping through a line, keep going if still within it.
3590 Note that step_range_end is the address of the first instruction
3591 beyond the step range, and NOT the address of the last instruction
3593 if (stop_pc
>= ecs
->event_thread
->step_range_start
3594 && stop_pc
< ecs
->event_thread
->step_range_end
)
3597 fprintf_unfiltered (gdb_stdlog
, "infrun: stepping inside range [0x%s-0x%s]\n",
3598 paddr_nz (ecs
->event_thread
->step_range_start
),
3599 paddr_nz (ecs
->event_thread
->step_range_end
));
3601 /* When stepping backward, stop at beginning of line range
3602 (unless it's the function entry point, in which case
3603 keep going back to the call point). */
3604 if (stop_pc
== ecs
->event_thread
->step_range_start
3605 && stop_pc
!= ecs
->stop_func_start
3606 && execution_direction
== EXEC_REVERSE
)
3608 ecs
->event_thread
->stop_step
= 1;
3609 print_stop_reason (END_STEPPING_RANGE
, 0);
3610 stop_stepping (ecs
);
3618 /* We stepped out of the stepping range. */
3620 /* If we are stepping at the source level and entered the runtime
3621 loader dynamic symbol resolution code, we keep on single stepping
3622 until we exit the run time loader code and reach the callee's
3624 if (ecs
->event_thread
->step_over_calls
== STEP_OVER_UNDEBUGGABLE
3625 && in_solib_dynsym_resolve_code (stop_pc
))
3627 CORE_ADDR pc_after_resolver
=
3628 gdbarch_skip_solib_resolver (current_gdbarch
, stop_pc
);
3631 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into dynsym resolve code\n");
3633 if (pc_after_resolver
)
3635 /* Set up a step-resume breakpoint at the address
3636 indicated by SKIP_SOLIB_RESOLVER. */
3637 struct symtab_and_line sr_sal
;
3639 sr_sal
.pc
= pc_after_resolver
;
3641 insert_step_resume_breakpoint_at_sal (sr_sal
, null_frame_id
);
3648 if (ecs
->event_thread
->step_range_end
!= 1
3649 && (ecs
->event_thread
->step_over_calls
== STEP_OVER_UNDEBUGGABLE
3650 || ecs
->event_thread
->step_over_calls
== STEP_OVER_ALL
)
3651 && get_frame_type (get_current_frame ()) == SIGTRAMP_FRAME
)
3654 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into signal trampoline\n");
3655 /* The inferior, while doing a "step" or "next", has ended up in
3656 a signal trampoline (either by a signal being delivered or by
3657 the signal handler returning). Just single-step until the
3658 inferior leaves the trampoline (either by calling the handler
3664 /* Check for subroutine calls. The check for the current frame
3665 equalling the step ID is not necessary - the check of the
3666 previous frame's ID is sufficient - but it is a common case and
3667 cheaper than checking the previous frame's ID.
3669 NOTE: frame_id_eq will never report two invalid frame IDs as
3670 being equal, so to get into this block, both the current and
3671 previous frame must have valid frame IDs. */
3672 if (!frame_id_eq (get_frame_id (get_current_frame ()),
3673 ecs
->event_thread
->step_frame_id
)
3674 && (frame_id_eq (frame_unwind_id (get_current_frame ()),
3675 ecs
->event_thread
->step_frame_id
)
3676 || execution_direction
== EXEC_REVERSE
))
3678 CORE_ADDR real_stop_pc
;
3681 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
3683 if ((ecs
->event_thread
->step_over_calls
== STEP_OVER_NONE
)
3684 || ((ecs
->event_thread
->step_range_end
== 1)
3685 && in_prologue (ecs
->event_thread
->prev_pc
,
3686 ecs
->stop_func_start
)))
3688 /* I presume that step_over_calls is only 0 when we're
3689 supposed to be stepping at the assembly language level
3690 ("stepi"). Just stop. */
3691 /* Also, maybe we just did a "nexti" inside a prolog, so we
3692 thought it was a subroutine call but it was not. Stop as
3694 ecs
->event_thread
->stop_step
= 1;
3695 print_stop_reason (END_STEPPING_RANGE
, 0);
3696 stop_stepping (ecs
);
3700 if (ecs
->event_thread
->step_over_calls
== STEP_OVER_ALL
)
3702 /* We're doing a "next".
3704 Normal (forward) execution: set a breakpoint at the
3705 callee's return address (the address at which the caller
3708 Reverse (backward) execution. set the step-resume
3709 breakpoint at the start of the function that we just
3710 stepped into (backwards), and continue to there. When we
3711 get there, we'll need to single-step back to the caller. */
3713 if (execution_direction
== EXEC_REVERSE
)
3715 struct symtab_and_line sr_sal
;
3717 if (ecs
->stop_func_start
== 0
3718 && in_solib_dynsym_resolve_code (stop_pc
))
3720 /* Stepped into runtime loader dynamic symbol
3721 resolution code. Since we're in reverse,
3722 we have already backed up through the runtime
3723 loader and the dynamic function. This is just
3724 the trampoline (jump table).
3726 Just keep stepping, we'll soon be home.
3731 /* Normal (staticly linked) function call return. */
3733 sr_sal
.pc
= ecs
->stop_func_start
;
3734 insert_step_resume_breakpoint_at_sal (sr_sal
, null_frame_id
);
3737 insert_step_resume_breakpoint_at_caller (get_current_frame ());
3743 /* If we are in a function call trampoline (a stub between the
3744 calling routine and the real function), locate the real
3745 function. That's what tells us (a) whether we want to step
3746 into it at all, and (b) what prologue we want to run to the
3747 end of, if we do step into it. */
3748 real_stop_pc
= skip_language_trampoline (get_current_frame (), stop_pc
);
3749 if (real_stop_pc
== 0)
3750 real_stop_pc
= gdbarch_skip_trampoline_code
3751 (current_gdbarch
, get_current_frame (), stop_pc
);
3752 if (real_stop_pc
!= 0)
3753 ecs
->stop_func_start
= real_stop_pc
;
3755 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
3757 struct symtab_and_line sr_sal
;
3759 sr_sal
.pc
= ecs
->stop_func_start
;
3761 insert_step_resume_breakpoint_at_sal (sr_sal
, null_frame_id
);
3766 /* If we have line number information for the function we are
3767 thinking of stepping into, step into it.
3769 If there are several symtabs at that PC (e.g. with include
3770 files), just want to know whether *any* of them have line
3771 numbers. find_pc_line handles this. */
3773 struct symtab_and_line tmp_sal
;
3775 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
3776 if (tmp_sal
.line
!= 0)
3778 if (execution_direction
== EXEC_REVERSE
)
3779 handle_step_into_function_backward (ecs
);
3781 handle_step_into_function (ecs
);
3786 /* If we have no line number and the step-stop-if-no-debug is
3787 set, we stop the step so that the user has a chance to switch
3788 in assembly mode. */
3789 if (ecs
->event_thread
->step_over_calls
== STEP_OVER_UNDEBUGGABLE
3790 && step_stop_if_no_debug
)
3792 ecs
->event_thread
->stop_step
= 1;
3793 print_stop_reason (END_STEPPING_RANGE
, 0);
3794 stop_stepping (ecs
);
3798 if (execution_direction
== EXEC_REVERSE
)
3800 /* Set a breakpoint at callee's start address.
3801 From there we can step once and be back in the caller. */
3802 struct symtab_and_line sr_sal
;
3804 sr_sal
.pc
= ecs
->stop_func_start
;
3805 insert_step_resume_breakpoint_at_sal (sr_sal
, null_frame_id
);
3808 /* Set a breakpoint at callee's return address (the address
3809 at which the caller will resume). */
3810 insert_step_resume_breakpoint_at_caller (get_current_frame ());
3816 /* If we're in the return path from a shared library trampoline,
3817 we want to proceed through the trampoline when stepping. */
3818 if (gdbarch_in_solib_return_trampoline (current_gdbarch
,
3819 stop_pc
, ecs
->stop_func_name
))
3821 /* Determine where this trampoline returns. */
3822 CORE_ADDR real_stop_pc
;
3823 real_stop_pc
= gdbarch_skip_trampoline_code
3824 (current_gdbarch
, get_current_frame (), stop_pc
);
3827 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into solib return tramp\n");
3829 /* Only proceed through if we know where it's going. */
3832 /* And put the step-breakpoint there and go until there. */
3833 struct symtab_and_line sr_sal
;
3835 init_sal (&sr_sal
); /* initialize to zeroes */
3836 sr_sal
.pc
= real_stop_pc
;
3837 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
3839 /* Do not specify what the fp should be when we stop since
3840 on some machines the prologue is where the new fp value
3842 insert_step_resume_breakpoint_at_sal (sr_sal
, null_frame_id
);
3844 /* Restart without fiddling with the step ranges or
3851 stop_pc_sal
= find_pc_line (stop_pc
, 0);
3853 /* NOTE: tausq/2004-05-24: This if block used to be done before all
3854 the trampoline processing logic, however, there are some trampolines
3855 that have no names, so we should do trampoline handling first. */
3856 if (ecs
->event_thread
->step_over_calls
== STEP_OVER_UNDEBUGGABLE
3857 && ecs
->stop_func_name
== NULL
3858 && stop_pc_sal
.line
== 0)
3861 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into undebuggable function\n");
3863 /* The inferior just stepped into, or returned to, an
3864 undebuggable function (where there is no debugging information
3865 and no line number corresponding to the address where the
3866 inferior stopped). Since we want to skip this kind of code,
3867 we keep going until the inferior returns from this
3868 function - unless the user has asked us not to (via
3869 set step-mode) or we no longer know how to get back
3870 to the call site. */
3871 if (step_stop_if_no_debug
3872 || !frame_id_p (frame_unwind_id (get_current_frame ())))
3874 /* If we have no line number and the step-stop-if-no-debug
3875 is set, we stop the step so that the user has a chance to
3876 switch in assembly mode. */
3877 ecs
->event_thread
->stop_step
= 1;
3878 print_stop_reason (END_STEPPING_RANGE
, 0);
3879 stop_stepping (ecs
);
3884 /* Set a breakpoint at callee's return address (the address
3885 at which the caller will resume). */
3886 insert_step_resume_breakpoint_at_caller (get_current_frame ());
3892 if (ecs
->event_thread
->step_range_end
== 1)
3894 /* It is stepi or nexti. We always want to stop stepping after
3897 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
3898 ecs
->event_thread
->stop_step
= 1;
3899 print_stop_reason (END_STEPPING_RANGE
, 0);
3900 stop_stepping (ecs
);
3904 if (stop_pc_sal
.line
== 0)
3906 /* We have no line number information. That means to stop
3907 stepping (does this always happen right after one instruction,
3908 when we do "s" in a function with no line numbers,
3909 or can this happen as a result of a return or longjmp?). */
3911 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
3912 ecs
->event_thread
->stop_step
= 1;
3913 print_stop_reason (END_STEPPING_RANGE
, 0);
3914 stop_stepping (ecs
);
3918 if ((stop_pc
== stop_pc_sal
.pc
)
3919 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
3920 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
3922 /* We are at the start of a different line. So stop. Note that
3923 we don't stop if we step into the middle of a different line.
3924 That is said to make things like for (;;) statements work
3927 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped to a different line\n");
3928 ecs
->event_thread
->stop_step
= 1;
3929 print_stop_reason (END_STEPPING_RANGE
, 0);
3930 stop_stepping (ecs
);
3934 /* We aren't done stepping.
3936 Optimize by setting the stepping range to the line.
3937 (We might not be in the original line, but if we entered a
3938 new line in mid-statement, we continue stepping. This makes
3939 things like for(;;) statements work better.) */
3941 ecs
->event_thread
->step_range_start
= stop_pc_sal
.pc
;
3942 ecs
->event_thread
->step_range_end
= stop_pc_sal
.end
;
3943 ecs
->event_thread
->step_frame_id
= get_frame_id (get_current_frame ());
3944 ecs
->event_thread
->current_line
= stop_pc_sal
.line
;
3945 ecs
->event_thread
->current_symtab
= stop_pc_sal
.symtab
;
3948 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
3952 /* Is thread TP in the middle of single-stepping? */
3955 currently_stepping (struct thread_info
*tp
)
3957 return ((tp
->step_range_end
&& tp
->step_resume_breakpoint
== NULL
)
3958 || tp
->trap_expected
3959 || tp
->stepping_through_solib_after_catch
3960 || bpstat_should_step ());
3963 /* Returns true if any thread *but* the one passed in "data" is in the
3964 middle of stepping or of handling a "next". */
3967 currently_stepping_or_nexting_callback (struct thread_info
*tp
, void *data
)
3972 return (tp
->step_range_end
3973 || tp
->trap_expected
3974 || tp
->stepping_through_solib_after_catch
);
3977 /* Inferior has stepped into a subroutine call with source code that
3978 we should not step over. Do step to the first line of code in
3982 handle_step_into_function (struct execution_control_state
*ecs
)
3985 struct symtab_and_line stop_func_sal
, sr_sal
;
3987 s
= find_pc_symtab (stop_pc
);
3988 if (s
&& s
->language
!= language_asm
)
3989 ecs
->stop_func_start
= gdbarch_skip_prologue (current_gdbarch
,
3990 ecs
->stop_func_start
);
3992 stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
3993 /* Use the step_resume_break to step until the end of the prologue,
3994 even if that involves jumps (as it seems to on the vax under
3996 /* If the prologue ends in the middle of a source line, continue to
3997 the end of that source line (if it is still within the function).
3998 Otherwise, just go to end of prologue. */
3999 if (stop_func_sal
.end
4000 && stop_func_sal
.pc
!= ecs
->stop_func_start
4001 && stop_func_sal
.end
< ecs
->stop_func_end
)
4002 ecs
->stop_func_start
= stop_func_sal
.end
;
4004 /* Architectures which require breakpoint adjustment might not be able
4005 to place a breakpoint at the computed address. If so, the test
4006 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
4007 ecs->stop_func_start to an address at which a breakpoint may be
4008 legitimately placed.
4010 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
4011 made, GDB will enter an infinite loop when stepping through
4012 optimized code consisting of VLIW instructions which contain
4013 subinstructions corresponding to different source lines. On
4014 FR-V, it's not permitted to place a breakpoint on any but the
4015 first subinstruction of a VLIW instruction. When a breakpoint is
4016 set, GDB will adjust the breakpoint address to the beginning of
4017 the VLIW instruction. Thus, we need to make the corresponding
4018 adjustment here when computing the stop address. */
4020 if (gdbarch_adjust_breakpoint_address_p (current_gdbarch
))
4022 ecs
->stop_func_start
4023 = gdbarch_adjust_breakpoint_address (current_gdbarch
,
4024 ecs
->stop_func_start
);
4027 if (ecs
->stop_func_start
== stop_pc
)
4029 /* We are already there: stop now. */
4030 ecs
->event_thread
->stop_step
= 1;
4031 print_stop_reason (END_STEPPING_RANGE
, 0);
4032 stop_stepping (ecs
);
4037 /* Put the step-breakpoint there and go until there. */
4038 init_sal (&sr_sal
); /* initialize to zeroes */
4039 sr_sal
.pc
= ecs
->stop_func_start
;
4040 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
4042 /* Do not specify what the fp should be when we stop since on
4043 some machines the prologue is where the new fp value is
4045 insert_step_resume_breakpoint_at_sal (sr_sal
, null_frame_id
);
4047 /* And make sure stepping stops right away then. */
4048 ecs
->event_thread
->step_range_end
= ecs
->event_thread
->step_range_start
;
4053 /* Inferior has stepped backward into a subroutine call with source
4054 code that we should not step over. Do step to the beginning of the
4055 last line of code in it. */
4058 handle_step_into_function_backward (struct execution_control_state
*ecs
)
4061 struct symtab_and_line stop_func_sal
, sr_sal
;
4063 s
= find_pc_symtab (stop_pc
);
4064 if (s
&& s
->language
!= language_asm
)
4065 ecs
->stop_func_start
= gdbarch_skip_prologue (current_gdbarch
,
4066 ecs
->stop_func_start
);
4068 stop_func_sal
= find_pc_line (stop_pc
, 0);
4070 /* OK, we're just going to keep stepping here. */
4071 if (stop_func_sal
.pc
== stop_pc
)
4073 /* We're there already. Just stop stepping now. */
4074 ecs
->event_thread
->stop_step
= 1;
4075 print_stop_reason (END_STEPPING_RANGE
, 0);
4076 stop_stepping (ecs
);
4080 /* Else just reset the step range and keep going.
4081 No step-resume breakpoint, they don't work for
4082 epilogues, which can have multiple entry paths. */
4083 ecs
->event_thread
->step_range_start
= stop_func_sal
.pc
;
4084 ecs
->event_thread
->step_range_end
= stop_func_sal
.end
;
4090 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
4091 This is used to both functions and to skip over code. */
4094 insert_step_resume_breakpoint_at_sal (struct symtab_and_line sr_sal
,
4095 struct frame_id sr_id
)
4097 /* There should never be more than one step-resume or longjmp-resume
4098 breakpoint per thread, so we should never be setting a new
4099 step_resume_breakpoint when one is already active. */
4100 gdb_assert (inferior_thread ()->step_resume_breakpoint
== NULL
);
4103 fprintf_unfiltered (gdb_stdlog
,
4104 "infrun: inserting step-resume breakpoint at 0x%s\n",
4105 paddr_nz (sr_sal
.pc
));
4107 inferior_thread ()->step_resume_breakpoint
4108 = set_momentary_breakpoint (sr_sal
, sr_id
, bp_step_resume
);
4111 /* Insert a "step-resume breakpoint" at RETURN_FRAME.pc. This is used
4112 to skip a potential signal handler.
4114 This is called with the interrupted function's frame. The signal
4115 handler, when it returns, will resume the interrupted function at
4119 insert_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
4121 struct symtab_and_line sr_sal
;
4123 gdb_assert (return_frame
!= NULL
);
4124 init_sal (&sr_sal
); /* initialize to zeros */
4126 sr_sal
.pc
= gdbarch_addr_bits_remove
4127 (current_gdbarch
, get_frame_pc (return_frame
));
4128 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
4130 insert_step_resume_breakpoint_at_sal (sr_sal
, get_frame_id (return_frame
));
4133 /* Similar to insert_step_resume_breakpoint_at_frame, except
4134 but a breakpoint at the previous frame's PC. This is used to
4135 skip a function after stepping into it (for "next" or if the called
4136 function has no debugging information).
4138 The current function has almost always been reached by single
4139 stepping a call or return instruction. NEXT_FRAME belongs to the
4140 current function, and the breakpoint will be set at the caller's
4143 This is a separate function rather than reusing
4144 insert_step_resume_breakpoint_at_frame in order to avoid
4145 get_prev_frame, which may stop prematurely (see the implementation
4146 of frame_unwind_id for an example). */
4149 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
4151 struct symtab_and_line sr_sal
;
4153 /* We shouldn't have gotten here if we don't know where the call site
4155 gdb_assert (frame_id_p (frame_unwind_id (next_frame
)));
4157 init_sal (&sr_sal
); /* initialize to zeros */
4159 sr_sal
.pc
= gdbarch_addr_bits_remove
4160 (current_gdbarch
, frame_pc_unwind (next_frame
));
4161 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
4163 insert_step_resume_breakpoint_at_sal (sr_sal
, frame_unwind_id (next_frame
));
4166 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
4167 new breakpoint at the target of a jmp_buf. The handling of
4168 longjmp-resume uses the same mechanisms used for handling
4169 "step-resume" breakpoints. */
4172 insert_longjmp_resume_breakpoint (CORE_ADDR pc
)
4174 /* There should never be more than one step-resume or longjmp-resume
4175 breakpoint per thread, so we should never be setting a new
4176 longjmp_resume_breakpoint when one is already active. */
4177 gdb_assert (inferior_thread ()->step_resume_breakpoint
== NULL
);
4180 fprintf_unfiltered (gdb_stdlog
,
4181 "infrun: inserting longjmp-resume breakpoint at 0x%s\n",
4184 inferior_thread ()->step_resume_breakpoint
=
4185 set_momentary_breakpoint_at_pc (pc
, bp_longjmp_resume
);
4189 stop_stepping (struct execution_control_state
*ecs
)
4192 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_stepping\n");
4194 /* Let callers know we don't want to wait for the inferior anymore. */
4195 ecs
->wait_some_more
= 0;
4198 /* This function handles various cases where we need to continue
4199 waiting for the inferior. */
4200 /* (Used to be the keep_going: label in the old wait_for_inferior) */
4203 keep_going (struct execution_control_state
*ecs
)
4205 /* Save the pc before execution, to compare with pc after stop. */
4206 ecs
->event_thread
->prev_pc
4207 = regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4209 /* If we did not do break;, it means we should keep running the
4210 inferior and not return to debugger. */
4212 if (ecs
->event_thread
->trap_expected
4213 && ecs
->event_thread
->stop_signal
!= TARGET_SIGNAL_TRAP
)
4215 /* We took a signal (which we are supposed to pass through to
4216 the inferior, else we'd not get here) and we haven't yet
4217 gotten our trap. Simply continue. */
4218 resume (currently_stepping (ecs
->event_thread
),
4219 ecs
->event_thread
->stop_signal
);
4223 /* Either the trap was not expected, but we are continuing
4224 anyway (the user asked that this signal be passed to the
4227 The signal was SIGTRAP, e.g. it was our signal, but we
4228 decided we should resume from it.
4230 We're going to run this baby now!
4232 Note that insert_breakpoints won't try to re-insert
4233 already inserted breakpoints. Therefore, we don't
4234 care if breakpoints were already inserted, or not. */
4236 if (ecs
->event_thread
->stepping_over_breakpoint
)
4238 if (! use_displaced_stepping (current_gdbarch
))
4239 /* Since we can't do a displaced step, we have to remove
4240 the breakpoint while we step it. To keep things
4241 simple, we remove them all. */
4242 remove_breakpoints ();
4246 struct gdb_exception e
;
4247 /* Stop stepping when inserting breakpoints
4249 TRY_CATCH (e
, RETURN_MASK_ERROR
)
4251 insert_breakpoints ();
4255 stop_stepping (ecs
);
4260 ecs
->event_thread
->trap_expected
= ecs
->event_thread
->stepping_over_breakpoint
;
4262 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
4263 specifies that such a signal should be delivered to the
4266 Typically, this would occure when a user is debugging a
4267 target monitor on a simulator: the target monitor sets a
4268 breakpoint; the simulator encounters this break-point and
4269 halts the simulation handing control to GDB; GDB, noteing
4270 that the break-point isn't valid, returns control back to the
4271 simulator; the simulator then delivers the hardware
4272 equivalent of a SIGNAL_TRAP to the program being debugged. */
4274 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
4275 && !signal_program
[ecs
->event_thread
->stop_signal
])
4276 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
4278 resume (currently_stepping (ecs
->event_thread
),
4279 ecs
->event_thread
->stop_signal
);
4282 prepare_to_wait (ecs
);
4285 /* This function normally comes after a resume, before
4286 handle_inferior_event exits. It takes care of any last bits of
4287 housekeeping, and sets the all-important wait_some_more flag. */
4290 prepare_to_wait (struct execution_control_state
*ecs
)
4293 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
4294 if (infwait_state
== infwait_normal_state
)
4296 overlay_cache_invalid
= 1;
4298 /* We have to invalidate the registers BEFORE calling
4299 target_wait because they can be loaded from the target while
4300 in target_wait. This makes remote debugging a bit more
4301 efficient for those targets that provide critical registers
4302 as part of their normal status mechanism. */
4304 registers_changed ();
4305 waiton_ptid
= pid_to_ptid (-1);
4307 /* This is the old end of the while loop. Let everybody know we
4308 want to wait for the inferior some more and get called again
4310 ecs
->wait_some_more
= 1;
4313 /* Print why the inferior has stopped. We always print something when
4314 the inferior exits, or receives a signal. The rest of the cases are
4315 dealt with later on in normal_stop() and print_it_typical(). Ideally
4316 there should be a call to this function from handle_inferior_event()
4317 each time stop_stepping() is called.*/
4319 print_stop_reason (enum inferior_stop_reason stop_reason
, int stop_info
)
4321 switch (stop_reason
)
4323 case END_STEPPING_RANGE
:
4324 /* We are done with a step/next/si/ni command. */
4325 /* For now print nothing. */
4326 /* Print a message only if not in the middle of doing a "step n"
4327 operation for n > 1 */
4328 if (!inferior_thread ()->step_multi
4329 || !inferior_thread ()->stop_step
)
4330 if (ui_out_is_mi_like_p (uiout
))
4333 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
4336 /* The inferior was terminated by a signal. */
4337 annotate_signalled ();
4338 if (ui_out_is_mi_like_p (uiout
))
4341 async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
4342 ui_out_text (uiout
, "\nProgram terminated with signal ");
4343 annotate_signal_name ();
4344 ui_out_field_string (uiout
, "signal-name",
4345 target_signal_to_name (stop_info
));
4346 annotate_signal_name_end ();
4347 ui_out_text (uiout
, ", ");
4348 annotate_signal_string ();
4349 ui_out_field_string (uiout
, "signal-meaning",
4350 target_signal_to_string (stop_info
));
4351 annotate_signal_string_end ();
4352 ui_out_text (uiout
, ".\n");
4353 ui_out_text (uiout
, "The program no longer exists.\n");
4356 /* The inferior program is finished. */
4357 annotate_exited (stop_info
);
4360 if (ui_out_is_mi_like_p (uiout
))
4361 ui_out_field_string (uiout
, "reason",
4362 async_reason_lookup (EXEC_ASYNC_EXITED
));
4363 ui_out_text (uiout
, "\nProgram exited with code ");
4364 ui_out_field_fmt (uiout
, "exit-code", "0%o",
4365 (unsigned int) stop_info
);
4366 ui_out_text (uiout
, ".\n");
4370 if (ui_out_is_mi_like_p (uiout
))
4373 async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
4374 ui_out_text (uiout
, "\nProgram exited normally.\n");
4376 /* Support the --return-child-result option. */
4377 return_child_result_value
= stop_info
;
4379 case SIGNAL_RECEIVED
:
4380 /* Signal received. The signal table tells us to print about
4384 if (stop_info
== TARGET_SIGNAL_0
&& !ui_out_is_mi_like_p (uiout
))
4386 struct thread_info
*t
= inferior_thread ();
4388 ui_out_text (uiout
, "\n[");
4389 ui_out_field_string (uiout
, "thread-name",
4390 target_pid_to_str (t
->ptid
));
4391 ui_out_field_fmt (uiout
, "thread-id", "] #%d", t
->num
);
4392 ui_out_text (uiout
, " stopped");
4396 ui_out_text (uiout
, "\nProgram received signal ");
4397 annotate_signal_name ();
4398 if (ui_out_is_mi_like_p (uiout
))
4400 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
4401 ui_out_field_string (uiout
, "signal-name",
4402 target_signal_to_name (stop_info
));
4403 annotate_signal_name_end ();
4404 ui_out_text (uiout
, ", ");
4405 annotate_signal_string ();
4406 ui_out_field_string (uiout
, "signal-meaning",
4407 target_signal_to_string (stop_info
));
4408 annotate_signal_string_end ();
4410 ui_out_text (uiout
, ".\n");
4413 /* Reverse execution: target ran out of history info. */
4414 ui_out_text (uiout
, "\nNo more reverse-execution history.\n");
4417 internal_error (__FILE__
, __LINE__
,
4418 _("print_stop_reason: unrecognized enum value"));
4424 /* Here to return control to GDB when the inferior stops for real.
4425 Print appropriate messages, remove breakpoints, give terminal our modes.
4427 STOP_PRINT_FRAME nonzero means print the executing frame
4428 (pc, function, args, file, line number and line text).
4429 BREAKPOINTS_FAILED nonzero means stop was due to error
4430 attempting to insert breakpoints. */
4435 struct target_waitstatus last
;
4437 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
4439 get_last_target_status (&last_ptid
, &last
);
4441 /* If an exception is thrown from this point on, make sure to
4442 propagate GDB's knowledge of the executing state to the
4443 frontend/user running state. A QUIT is an easy exception to see
4444 here, so do this before any filtered output. */
4445 if (target_has_execution
)
4448 make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
4449 else if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
4450 && last
.kind
!= TARGET_WAITKIND_EXITED
)
4451 make_cleanup (finish_thread_state_cleanup
, &inferior_ptid
);
4454 /* In non-stop mode, we don't want GDB to switch threads behind the
4455 user's back, to avoid races where the user is typing a command to
4456 apply to thread x, but GDB switches to thread y before the user
4457 finishes entering the command. */
4459 /* As with the notification of thread events, we want to delay
4460 notifying the user that we've switched thread context until
4461 the inferior actually stops.
4463 There's no point in saying anything if the inferior has exited.
4464 Note that SIGNALLED here means "exited with a signal", not
4465 "received a signal". */
4467 && !ptid_equal (previous_inferior_ptid
, inferior_ptid
)
4468 && target_has_execution
4469 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
4470 && last
.kind
!= TARGET_WAITKIND_EXITED
)
4472 target_terminal_ours_for_output ();
4473 printf_filtered (_("[Switching to %s]\n"),
4474 target_pid_to_str (inferior_ptid
));
4475 annotate_thread_changed ();
4476 previous_inferior_ptid
= inferior_ptid
;
4479 if (!breakpoints_always_inserted_mode () && target_has_execution
)
4481 if (remove_breakpoints ())
4483 target_terminal_ours_for_output ();
4484 printf_filtered (_("\
4485 Cannot remove breakpoints because program is no longer writable.\n\
4486 Further execution is probably impossible.\n"));
4490 /* If an auto-display called a function and that got a signal,
4491 delete that auto-display to avoid an infinite recursion. */
4493 if (stopped_by_random_signal
)
4494 disable_current_display ();
4496 /* Don't print a message if in the middle of doing a "step n"
4497 operation for n > 1 */
4498 if (target_has_execution
4499 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
4500 && last
.kind
!= TARGET_WAITKIND_EXITED
4501 && inferior_thread ()->step_multi
4502 && inferior_thread ()->stop_step
)
4505 target_terminal_ours ();
4507 /* Set the current source location. This will also happen if we
4508 display the frame below, but the current SAL will be incorrect
4509 during a user hook-stop function. */
4510 if (has_stack_frames () && !stop_stack_dummy
)
4511 set_current_sal_from_frame (get_current_frame (), 1);
4513 /* Let the user/frontend see the threads as stopped. */
4514 do_cleanups (old_chain
);
4516 /* Look up the hook_stop and run it (CLI internally handles problem
4517 of stop_command's pre-hook not existing). */
4519 catch_errors (hook_stop_stub
, stop_command
,
4520 "Error while running hook_stop:\n", RETURN_MASK_ALL
);
4522 if (!has_stack_frames ())
4525 if (last
.kind
== TARGET_WAITKIND_SIGNALLED
4526 || last
.kind
== TARGET_WAITKIND_EXITED
)
4529 /* Select innermost stack frame - i.e., current frame is frame 0,
4530 and current location is based on that.
4531 Don't do this on return from a stack dummy routine,
4532 or if the program has exited. */
4534 if (!stop_stack_dummy
)
4536 select_frame (get_current_frame ());
4538 /* Print current location without a level number, if
4539 we have changed functions or hit a breakpoint.
4540 Print source line if we have one.
4541 bpstat_print() contains the logic deciding in detail
4542 what to print, based on the event(s) that just occurred. */
4544 /* If --batch-silent is enabled then there's no need to print the current
4545 source location, and to try risks causing an error message about
4546 missing source files. */
4547 if (stop_print_frame
&& !batch_silent
)
4551 int do_frame_printing
= 1;
4552 struct thread_info
*tp
= inferior_thread ();
4554 bpstat_ret
= bpstat_print (tp
->stop_bpstat
);
4558 /* If we had hit a shared library event breakpoint,
4559 bpstat_print would print out this message. If we hit
4560 an OS-level shared library event, do the same
4562 if (last
.kind
== TARGET_WAITKIND_LOADED
)
4564 printf_filtered (_("Stopped due to shared library event\n"));
4565 source_flag
= SRC_LINE
; /* something bogus */
4566 do_frame_printing
= 0;
4570 /* FIXME: cagney/2002-12-01: Given that a frame ID does
4571 (or should) carry around the function and does (or
4572 should) use that when doing a frame comparison. */
4574 && frame_id_eq (tp
->step_frame_id
,
4575 get_frame_id (get_current_frame ()))
4576 && step_start_function
== find_pc_function (stop_pc
))
4577 source_flag
= SRC_LINE
; /* finished step, just print source line */
4579 source_flag
= SRC_AND_LOC
; /* print location and source line */
4581 case PRINT_SRC_AND_LOC
:
4582 source_flag
= SRC_AND_LOC
; /* print location and source line */
4584 case PRINT_SRC_ONLY
:
4585 source_flag
= SRC_LINE
;
4588 source_flag
= SRC_LINE
; /* something bogus */
4589 do_frame_printing
= 0;
4592 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
4595 /* The behavior of this routine with respect to the source
4597 SRC_LINE: Print only source line
4598 LOCATION: Print only location
4599 SRC_AND_LOC: Print location and source line */
4600 if (do_frame_printing
)
4601 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
);
4603 /* Display the auto-display expressions. */
4608 /* Save the function value return registers, if we care.
4609 We might be about to restore their previous contents. */
4610 if (inferior_thread ()->proceed_to_finish
)
4612 /* This should not be necessary. */
4614 regcache_xfree (stop_registers
);
4616 /* NB: The copy goes through to the target picking up the value of
4617 all the registers. */
4618 stop_registers
= regcache_dup (get_current_regcache ());
4621 if (stop_stack_dummy
)
4623 /* Pop the empty frame that contains the stack dummy.
4624 This also restores inferior state prior to the call
4625 (struct inferior_thread_state). */
4626 struct frame_info
*frame
= get_current_frame ();
4627 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
4629 /* frame_pop() calls reinit_frame_cache as the last thing it does
4630 which means there's currently no selected frame. We don't need
4631 to re-establish a selected frame if the dummy call returns normally,
4632 that will be done by restore_inferior_status. However, we do have
4633 to handle the case where the dummy call is returning after being
4634 stopped (e.g. the dummy call previously hit a breakpoint). We
4635 can't know which case we have so just always re-establish a
4636 selected frame here. */
4637 select_frame (get_current_frame ());
4641 annotate_stopped ();
4643 /* Suppress the stop observer if we're in the middle of:
4645 - a step n (n > 1), as there still more steps to be done.
4647 - a "finish" command, as the observer will be called in
4648 finish_command_continuation, so it can include the inferior
4649 function's return value.
4651 - calling an inferior function, as we pretend we inferior didn't
4652 run at all. The return value of the call is handled by the
4653 expression evaluator, through call_function_by_hand. */
4655 if (!target_has_execution
4656 || last
.kind
== TARGET_WAITKIND_SIGNALLED
4657 || last
.kind
== TARGET_WAITKIND_EXITED
4658 || (!inferior_thread ()->step_multi
4659 && !(inferior_thread ()->stop_bpstat
4660 && inferior_thread ()->proceed_to_finish
)
4661 && !inferior_thread ()->in_infcall
))
4663 if (!ptid_equal (inferior_ptid
, null_ptid
))
4664 observer_notify_normal_stop (inferior_thread ()->stop_bpstat
,
4667 observer_notify_normal_stop (NULL
, stop_print_frame
);
4670 if (target_has_execution
)
4672 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
4673 && last
.kind
!= TARGET_WAITKIND_EXITED
)
4674 /* Delete the breakpoint we stopped at, if it wants to be deleted.
4675 Delete any breakpoint that is to be deleted at the next stop. */
4676 breakpoint_auto_delete (inferior_thread ()->stop_bpstat
);
4681 hook_stop_stub (void *cmd
)
4683 execute_cmd_pre_hook ((struct cmd_list_element
*) cmd
);
4688 signal_stop_state (int signo
)
4690 return signal_stop
[signo
];
4694 signal_print_state (int signo
)
4696 return signal_print
[signo
];
4700 signal_pass_state (int signo
)
4702 return signal_program
[signo
];
4706 signal_stop_update (int signo
, int state
)
4708 int ret
= signal_stop
[signo
];
4709 signal_stop
[signo
] = state
;
4714 signal_print_update (int signo
, int state
)
4716 int ret
= signal_print
[signo
];
4717 signal_print
[signo
] = state
;
4722 signal_pass_update (int signo
, int state
)
4724 int ret
= signal_program
[signo
];
4725 signal_program
[signo
] = state
;
4730 sig_print_header (void)
4732 printf_filtered (_("\
4733 Signal Stop\tPrint\tPass to program\tDescription\n"));
4737 sig_print_info (enum target_signal oursig
)
4739 const char *name
= target_signal_to_name (oursig
);
4740 int name_padding
= 13 - strlen (name
);
4742 if (name_padding
<= 0)
4745 printf_filtered ("%s", name
);
4746 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
4747 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
4748 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
4749 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
4750 printf_filtered ("%s\n", target_signal_to_string (oursig
));
4753 /* Specify how various signals in the inferior should be handled. */
4756 handle_command (char *args
, int from_tty
)
4759 int digits
, wordlen
;
4760 int sigfirst
, signum
, siglast
;
4761 enum target_signal oursig
;
4764 unsigned char *sigs
;
4765 struct cleanup
*old_chain
;
4769 error_no_arg (_("signal to handle"));
4772 /* Allocate and zero an array of flags for which signals to handle. */
4774 nsigs
= (int) TARGET_SIGNAL_LAST
;
4775 sigs
= (unsigned char *) alloca (nsigs
);
4776 memset (sigs
, 0, nsigs
);
4778 /* Break the command line up into args. */
4780 argv
= gdb_buildargv (args
);
4781 old_chain
= make_cleanup_freeargv (argv
);
4783 /* Walk through the args, looking for signal oursigs, signal names, and
4784 actions. Signal numbers and signal names may be interspersed with
4785 actions, with the actions being performed for all signals cumulatively
4786 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
4788 while (*argv
!= NULL
)
4790 wordlen
= strlen (*argv
);
4791 for (digits
= 0; isdigit ((*argv
)[digits
]); digits
++)
4795 sigfirst
= siglast
= -1;
4797 if (wordlen
>= 1 && !strncmp (*argv
, "all", wordlen
))
4799 /* Apply action to all signals except those used by the
4800 debugger. Silently skip those. */
4803 siglast
= nsigs
- 1;
4805 else if (wordlen
>= 1 && !strncmp (*argv
, "stop", wordlen
))
4807 SET_SIGS (nsigs
, sigs
, signal_stop
);
4808 SET_SIGS (nsigs
, sigs
, signal_print
);
4810 else if (wordlen
>= 1 && !strncmp (*argv
, "ignore", wordlen
))
4812 UNSET_SIGS (nsigs
, sigs
, signal_program
);
4814 else if (wordlen
>= 2 && !strncmp (*argv
, "print", wordlen
))
4816 SET_SIGS (nsigs
, sigs
, signal_print
);
4818 else if (wordlen
>= 2 && !strncmp (*argv
, "pass", wordlen
))
4820 SET_SIGS (nsigs
, sigs
, signal_program
);
4822 else if (wordlen
>= 3 && !strncmp (*argv
, "nostop", wordlen
))
4824 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
4826 else if (wordlen
>= 3 && !strncmp (*argv
, "noignore", wordlen
))
4828 SET_SIGS (nsigs
, sigs
, signal_program
);
4830 else if (wordlen
>= 4 && !strncmp (*argv
, "noprint", wordlen
))
4832 UNSET_SIGS (nsigs
, sigs
, signal_print
);
4833 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
4835 else if (wordlen
>= 4 && !strncmp (*argv
, "nopass", wordlen
))
4837 UNSET_SIGS (nsigs
, sigs
, signal_program
);
4839 else if (digits
> 0)
4841 /* It is numeric. The numeric signal refers to our own
4842 internal signal numbering from target.h, not to host/target
4843 signal number. This is a feature; users really should be
4844 using symbolic names anyway, and the common ones like
4845 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
4847 sigfirst
= siglast
= (int)
4848 target_signal_from_command (atoi (*argv
));
4849 if ((*argv
)[digits
] == '-')
4852 target_signal_from_command (atoi ((*argv
) + digits
+ 1));
4854 if (sigfirst
> siglast
)
4856 /* Bet he didn't figure we'd think of this case... */
4864 oursig
= target_signal_from_name (*argv
);
4865 if (oursig
!= TARGET_SIGNAL_UNKNOWN
)
4867 sigfirst
= siglast
= (int) oursig
;
4871 /* Not a number and not a recognized flag word => complain. */
4872 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv
);
4876 /* If any signal numbers or symbol names were found, set flags for
4877 which signals to apply actions to. */
4879 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
4881 switch ((enum target_signal
) signum
)
4883 case TARGET_SIGNAL_TRAP
:
4884 case TARGET_SIGNAL_INT
:
4885 if (!allsigs
&& !sigs
[signum
])
4887 if (query (_("%s is used by the debugger.\n\
4888 Are you sure you want to change it? "), target_signal_to_name ((enum target_signal
) signum
)))
4894 printf_unfiltered (_("Not confirmed, unchanged.\n"));
4895 gdb_flush (gdb_stdout
);
4899 case TARGET_SIGNAL_0
:
4900 case TARGET_SIGNAL_DEFAULT
:
4901 case TARGET_SIGNAL_UNKNOWN
:
4902 /* Make sure that "all" doesn't print these. */
4913 for (signum
= 0; signum
< nsigs
; signum
++)
4916 target_notice_signals (inferior_ptid
);
4920 /* Show the results. */
4921 sig_print_header ();
4922 for (; signum
< nsigs
; signum
++)
4924 sig_print_info (signum
);
4930 do_cleanups (old_chain
);
4934 xdb_handle_command (char *args
, int from_tty
)
4937 struct cleanup
*old_chain
;
4940 error_no_arg (_("xdb command"));
4942 /* Break the command line up into args. */
4944 argv
= gdb_buildargv (args
);
4945 old_chain
= make_cleanup_freeargv (argv
);
4946 if (argv
[1] != (char *) NULL
)
4951 bufLen
= strlen (argv
[0]) + 20;
4952 argBuf
= (char *) xmalloc (bufLen
);
4956 enum target_signal oursig
;
4958 oursig
= target_signal_from_name (argv
[0]);
4959 memset (argBuf
, 0, bufLen
);
4960 if (strcmp (argv
[1], "Q") == 0)
4961 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
4964 if (strcmp (argv
[1], "s") == 0)
4966 if (!signal_stop
[oursig
])
4967 sprintf (argBuf
, "%s %s", argv
[0], "stop");
4969 sprintf (argBuf
, "%s %s", argv
[0], "nostop");
4971 else if (strcmp (argv
[1], "i") == 0)
4973 if (!signal_program
[oursig
])
4974 sprintf (argBuf
, "%s %s", argv
[0], "pass");
4976 sprintf (argBuf
, "%s %s", argv
[0], "nopass");
4978 else if (strcmp (argv
[1], "r") == 0)
4980 if (!signal_print
[oursig
])
4981 sprintf (argBuf
, "%s %s", argv
[0], "print");
4983 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
4989 handle_command (argBuf
, from_tty
);
4991 printf_filtered (_("Invalid signal handling flag.\n"));
4996 do_cleanups (old_chain
);
4999 /* Print current contents of the tables set by the handle command.
5000 It is possible we should just be printing signals actually used
5001 by the current target (but for things to work right when switching
5002 targets, all signals should be in the signal tables). */
5005 signals_info (char *signum_exp
, int from_tty
)
5007 enum target_signal oursig
;
5008 sig_print_header ();
5012 /* First see if this is a symbol name. */
5013 oursig
= target_signal_from_name (signum_exp
);
5014 if (oursig
== TARGET_SIGNAL_UNKNOWN
)
5016 /* No, try numeric. */
5018 target_signal_from_command (parse_and_eval_long (signum_exp
));
5020 sig_print_info (oursig
);
5024 printf_filtered ("\n");
5025 /* These ugly casts brought to you by the native VAX compiler. */
5026 for (oursig
= TARGET_SIGNAL_FIRST
;
5027 (int) oursig
< (int) TARGET_SIGNAL_LAST
;
5028 oursig
= (enum target_signal
) ((int) oursig
+ 1))
5032 if (oursig
!= TARGET_SIGNAL_UNKNOWN
5033 && oursig
!= TARGET_SIGNAL_DEFAULT
&& oursig
!= TARGET_SIGNAL_0
)
5034 sig_print_info (oursig
);
5037 printf_filtered (_("\nUse the \"handle\" command to change these tables.\n"));
5040 /* The $_siginfo convenience variable is a bit special. We don't know
5041 for sure the type of the value until we actually have a chance to
5042 fetch the data. The type can change depending on gdbarch, so it it
5043 also dependent on which thread you have selected.
5045 1. making $_siginfo be an internalvar that creates a new value on
5048 2. making the value of $_siginfo be an lval_computed value. */
5050 /* This function implements the lval_computed support for reading a
5054 siginfo_value_read (struct value
*v
)
5056 LONGEST transferred
;
5059 target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
,
5061 value_contents_all_raw (v
),
5063 TYPE_LENGTH (value_type (v
)));
5065 if (transferred
!= TYPE_LENGTH (value_type (v
)))
5066 error (_("Unable to read siginfo"));
5069 /* This function implements the lval_computed support for writing a
5073 siginfo_value_write (struct value
*v
, struct value
*fromval
)
5075 LONGEST transferred
;
5077 transferred
= target_write (¤t_target
,
5078 TARGET_OBJECT_SIGNAL_INFO
,
5080 value_contents_all_raw (fromval
),
5082 TYPE_LENGTH (value_type (fromval
)));
5084 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
5085 error (_("Unable to write siginfo"));
5088 static struct lval_funcs siginfo_value_funcs
=
5094 /* Return a new value with the correct type for the siginfo object of
5095 the current thread. Return a void value if there's no object
5098 static struct value
*
5099 siginfo_make_value (struct internalvar
*var
)
5102 struct gdbarch
*gdbarch
;
5104 if (target_has_stack
5105 && !ptid_equal (inferior_ptid
, null_ptid
))
5107 gdbarch
= get_frame_arch (get_current_frame ());
5109 if (gdbarch_get_siginfo_type_p (gdbarch
))
5111 type
= gdbarch_get_siginfo_type (gdbarch
);
5113 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
5117 return allocate_value (builtin_type_void
);
5121 /* Inferior thread state.
5122 These are details related to the inferior itself, and don't include
5123 things like what frame the user had selected or what gdb was doing
5124 with the target at the time.
5125 For inferior function calls these are things we want to restore
5126 regardless of whether the function call successfully completes
5127 or the dummy frame has to be manually popped. */
5129 struct inferior_thread_state
5131 enum target_signal stop_signal
;
5133 struct regcache
*registers
;
5136 struct inferior_thread_state
*
5137 save_inferior_thread_state (void)
5139 struct inferior_thread_state
*inf_state
= XMALLOC (struct inferior_thread_state
);
5140 struct thread_info
*tp
= inferior_thread ();
5142 inf_state
->stop_signal
= tp
->stop_signal
;
5143 inf_state
->stop_pc
= stop_pc
;
5145 inf_state
->registers
= regcache_dup (get_current_regcache ());
5150 /* Restore inferior session state to INF_STATE. */
5153 restore_inferior_thread_state (struct inferior_thread_state
*inf_state
)
5155 struct thread_info
*tp
= inferior_thread ();
5157 tp
->stop_signal
= inf_state
->stop_signal
;
5158 stop_pc
= inf_state
->stop_pc
;
5160 /* The inferior can be gone if the user types "print exit(0)"
5161 (and perhaps other times). */
5162 if (target_has_execution
)
5163 /* NB: The register write goes through to the target. */
5164 regcache_cpy (get_current_regcache (), inf_state
->registers
);
5165 regcache_xfree (inf_state
->registers
);
5170 do_restore_inferior_thread_state_cleanup (void *state
)
5172 restore_inferior_thread_state (state
);
5176 make_cleanup_restore_inferior_thread_state (struct inferior_thread_state
*inf_state
)
5178 return make_cleanup (do_restore_inferior_thread_state_cleanup
, inf_state
);
5182 discard_inferior_thread_state (struct inferior_thread_state
*inf_state
)
5184 regcache_xfree (inf_state
->registers
);
5189 get_inferior_thread_state_regcache (struct inferior_thread_state
*inf_state
)
5191 return inf_state
->registers
;
5194 /* Session related state for inferior function calls.
5195 These are the additional bits of state that need to be restored
5196 when an inferior function call successfully completes. */
5198 struct inferior_status
5202 int stop_stack_dummy
;
5203 int stopped_by_random_signal
;
5204 int stepping_over_breakpoint
;
5205 CORE_ADDR step_range_start
;
5206 CORE_ADDR step_range_end
;
5207 struct frame_id step_frame_id
;
5208 enum step_over_calls_kind step_over_calls
;
5209 CORE_ADDR step_resume_break_address
;
5210 int stop_after_trap
;
5213 /* ID if the selected frame when the inferior function call was made. */
5214 struct frame_id selected_frame_id
;
5216 int proceed_to_finish
;
5220 /* Save all of the information associated with the inferior<==>gdb
5223 struct inferior_status
*
5224 save_inferior_status (void)
5226 struct inferior_status
*inf_status
= XMALLOC (struct inferior_status
);
5227 struct thread_info
*tp
= inferior_thread ();
5228 struct inferior
*inf
= current_inferior ();
5230 inf_status
->stop_step
= tp
->stop_step
;
5231 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
5232 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
5233 inf_status
->stepping_over_breakpoint
= tp
->trap_expected
;
5234 inf_status
->step_range_start
= tp
->step_range_start
;
5235 inf_status
->step_range_end
= tp
->step_range_end
;
5236 inf_status
->step_frame_id
= tp
->step_frame_id
;
5237 inf_status
->step_over_calls
= tp
->step_over_calls
;
5238 inf_status
->stop_after_trap
= stop_after_trap
;
5239 inf_status
->stop_soon
= inf
->stop_soon
;
5240 /* Save original bpstat chain here; replace it with copy of chain.
5241 If caller's caller is walking the chain, they'll be happier if we
5242 hand them back the original chain when restore_inferior_status is
5244 inf_status
->stop_bpstat
= tp
->stop_bpstat
;
5245 tp
->stop_bpstat
= bpstat_copy (tp
->stop_bpstat
);
5246 inf_status
->proceed_to_finish
= tp
->proceed_to_finish
;
5247 inf_status
->in_infcall
= tp
->in_infcall
;
5249 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
5255 restore_selected_frame (void *args
)
5257 struct frame_id
*fid
= (struct frame_id
*) args
;
5258 struct frame_info
*frame
;
5260 frame
= frame_find_by_id (*fid
);
5262 /* If inf_status->selected_frame_id is NULL, there was no previously
5266 warning (_("Unable to restore previously selected frame."));
5270 select_frame (frame
);
5275 /* Restore inferior session state to INF_STATUS. */
5278 restore_inferior_status (struct inferior_status
*inf_status
)
5280 struct thread_info
*tp
= inferior_thread ();
5281 struct inferior
*inf
= current_inferior ();
5283 tp
->stop_step
= inf_status
->stop_step
;
5284 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
5285 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
5286 tp
->trap_expected
= inf_status
->stepping_over_breakpoint
;
5287 tp
->step_range_start
= inf_status
->step_range_start
;
5288 tp
->step_range_end
= inf_status
->step_range_end
;
5289 tp
->step_frame_id
= inf_status
->step_frame_id
;
5290 tp
->step_over_calls
= inf_status
->step_over_calls
;
5291 stop_after_trap
= inf_status
->stop_after_trap
;
5292 inf
->stop_soon
= inf_status
->stop_soon
;
5293 bpstat_clear (&tp
->stop_bpstat
);
5294 tp
->stop_bpstat
= inf_status
->stop_bpstat
;
5295 inf_status
->stop_bpstat
= NULL
;
5296 tp
->proceed_to_finish
= inf_status
->proceed_to_finish
;
5297 tp
->in_infcall
= inf_status
->in_infcall
;
5299 if (target_has_stack
)
5301 /* The point of catch_errors is that if the stack is clobbered,
5302 walking the stack might encounter a garbage pointer and
5303 error() trying to dereference it. */
5305 (restore_selected_frame
, &inf_status
->selected_frame_id
,
5306 "Unable to restore previously selected frame:\n",
5307 RETURN_MASK_ERROR
) == 0)
5308 /* Error in restoring the selected frame. Select the innermost
5310 select_frame (get_current_frame ());
5317 do_restore_inferior_status_cleanup (void *sts
)
5319 restore_inferior_status (sts
);
5323 make_cleanup_restore_inferior_status (struct inferior_status
*inf_status
)
5325 return make_cleanup (do_restore_inferior_status_cleanup
, inf_status
);
5329 discard_inferior_status (struct inferior_status
*inf_status
)
5331 /* See save_inferior_status for info on stop_bpstat. */
5332 bpstat_clear (&inf_status
->stop_bpstat
);
5337 inferior_has_forked (ptid_t pid
, ptid_t
*child_pid
)
5339 struct target_waitstatus last
;
5342 get_last_target_status (&last_ptid
, &last
);
5344 if (last
.kind
!= TARGET_WAITKIND_FORKED
)
5347 if (!ptid_equal (last_ptid
, pid
))
5350 *child_pid
= last
.value
.related_pid
;
5355 inferior_has_vforked (ptid_t pid
, ptid_t
*child_pid
)
5357 struct target_waitstatus last
;
5360 get_last_target_status (&last_ptid
, &last
);
5362 if (last
.kind
!= TARGET_WAITKIND_VFORKED
)
5365 if (!ptid_equal (last_ptid
, pid
))
5368 *child_pid
= last
.value
.related_pid
;
5373 inferior_has_execd (ptid_t pid
, char **execd_pathname
)
5375 struct target_waitstatus last
;
5378 get_last_target_status (&last_ptid
, &last
);
5380 if (last
.kind
!= TARGET_WAITKIND_EXECD
)
5383 if (!ptid_equal (last_ptid
, pid
))
5386 *execd_pathname
= xstrdup (last
.value
.execd_pathname
);
5390 /* Oft used ptids */
5392 ptid_t minus_one_ptid
;
5394 /* Create a ptid given the necessary PID, LWP, and TID components. */
5397 ptid_build (int pid
, long lwp
, long tid
)
5407 /* Create a ptid from just a pid. */
5410 pid_to_ptid (int pid
)
5412 return ptid_build (pid
, 0, 0);
5415 /* Fetch the pid (process id) component from a ptid. */
5418 ptid_get_pid (ptid_t ptid
)
5423 /* Fetch the lwp (lightweight process) component from a ptid. */
5426 ptid_get_lwp (ptid_t ptid
)
5431 /* Fetch the tid (thread id) component from a ptid. */
5434 ptid_get_tid (ptid_t ptid
)
5439 /* ptid_equal() is used to test equality of two ptids. */
5442 ptid_equal (ptid_t ptid1
, ptid_t ptid2
)
5444 return (ptid1
.pid
== ptid2
.pid
&& ptid1
.lwp
== ptid2
.lwp
5445 && ptid1
.tid
== ptid2
.tid
);
5448 /* Returns true if PTID represents a process. */
5451 ptid_is_pid (ptid_t ptid
)
5453 if (ptid_equal (minus_one_ptid
, ptid
))
5455 if (ptid_equal (null_ptid
, ptid
))
5458 return (ptid_get_lwp (ptid
) == 0 && ptid_get_tid (ptid
) == 0);
5461 /* restore_inferior_ptid() will be used by the cleanup machinery
5462 to restore the inferior_ptid value saved in a call to
5463 save_inferior_ptid(). */
5466 restore_inferior_ptid (void *arg
)
5468 ptid_t
*saved_ptid_ptr
= arg
;
5469 inferior_ptid
= *saved_ptid_ptr
;
5473 /* Save the value of inferior_ptid so that it may be restored by a
5474 later call to do_cleanups(). Returns the struct cleanup pointer
5475 needed for later doing the cleanup. */
5478 save_inferior_ptid (void)
5480 ptid_t
*saved_ptid_ptr
;
5482 saved_ptid_ptr
= xmalloc (sizeof (ptid_t
));
5483 *saved_ptid_ptr
= inferior_ptid
;
5484 return make_cleanup (restore_inferior_ptid
, saved_ptid_ptr
);
5488 /* User interface for reverse debugging:
5489 Set exec-direction / show exec-direction commands
5490 (returns error unless target implements to_set_exec_direction method). */
5492 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
5493 static const char exec_forward
[] = "forward";
5494 static const char exec_reverse
[] = "reverse";
5495 static const char *exec_direction
= exec_forward
;
5496 static const char *exec_direction_names
[] = {
5503 set_exec_direction_func (char *args
, int from_tty
,
5504 struct cmd_list_element
*cmd
)
5506 if (target_can_execute_reverse
)
5508 if (!strcmp (exec_direction
, exec_forward
))
5509 execution_direction
= EXEC_FORWARD
;
5510 else if (!strcmp (exec_direction
, exec_reverse
))
5511 execution_direction
= EXEC_REVERSE
;
5516 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
5517 struct cmd_list_element
*cmd
, const char *value
)
5519 switch (execution_direction
) {
5521 fprintf_filtered (out
, _("Forward.\n"));
5524 fprintf_filtered (out
, _("Reverse.\n"));
5528 fprintf_filtered (out
,
5529 _("Forward (target `%s' does not support exec-direction).\n"),
5535 /* User interface for non-stop mode. */
5538 static int non_stop_1
= 0;
5541 set_non_stop (char *args
, int from_tty
,
5542 struct cmd_list_element
*c
)
5544 if (target_has_execution
)
5546 non_stop_1
= non_stop
;
5547 error (_("Cannot change this setting while the inferior is running."));
5550 non_stop
= non_stop_1
;
5554 show_non_stop (struct ui_file
*file
, int from_tty
,
5555 struct cmd_list_element
*c
, const char *value
)
5557 fprintf_filtered (file
,
5558 _("Controlling the inferior in non-stop mode is %s.\n"),
5564 _initialize_infrun (void)
5568 struct cmd_list_element
*c
;
5570 add_info ("signals", signals_info
, _("\
5571 What debugger does when program gets various signals.\n\
5572 Specify a signal as argument to print info on that signal only."));
5573 add_info_alias ("handle", "signals", 0);
5575 add_com ("handle", class_run
, handle_command
, _("\
5576 Specify how to handle a signal.\n\
5577 Args are signals and actions to apply to those signals.\n\
5578 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
5579 from 1-15 are allowed for compatibility with old versions of GDB.\n\
5580 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
5581 The special arg \"all\" is recognized to mean all signals except those\n\
5582 used by the debugger, typically SIGTRAP and SIGINT.\n\
5583 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
5584 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
5585 Stop means reenter debugger if this signal happens (implies print).\n\
5586 Print means print a message if this signal happens.\n\
5587 Pass means let program see this signal; otherwise program doesn't know.\n\
5588 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
5589 Pass and Stop may be combined."));
5592 add_com ("lz", class_info
, signals_info
, _("\
5593 What debugger does when program gets various signals.\n\
5594 Specify a signal as argument to print info on that signal only."));
5595 add_com ("z", class_run
, xdb_handle_command
, _("\
5596 Specify how to handle a signal.\n\
5597 Args are signals and actions to apply to those signals.\n\
5598 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
5599 from 1-15 are allowed for compatibility with old versions of GDB.\n\
5600 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
5601 The special arg \"all\" is recognized to mean all signals except those\n\
5602 used by the debugger, typically SIGTRAP and SIGINT.\n\
5603 Recognized actions include \"s\" (toggles between stop and nostop), \n\
5604 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
5605 nopass), \"Q\" (noprint)\n\
5606 Stop means reenter debugger if this signal happens (implies print).\n\
5607 Print means print a message if this signal happens.\n\
5608 Pass means let program see this signal; otherwise program doesn't know.\n\
5609 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
5610 Pass and Stop may be combined."));
5614 stop_command
= add_cmd ("stop", class_obscure
,
5615 not_just_help_class_command
, _("\
5616 There is no `stop' command, but you can set a hook on `stop'.\n\
5617 This allows you to set a list of commands to be run each time execution\n\
5618 of the program stops."), &cmdlist
);
5620 add_setshow_zinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
5621 Set inferior debugging."), _("\
5622 Show inferior debugging."), _("\
5623 When non-zero, inferior specific debugging is enabled."),
5626 &setdebuglist
, &showdebuglist
);
5628 add_setshow_boolean_cmd ("displaced", class_maintenance
, &debug_displaced
, _("\
5629 Set displaced stepping debugging."), _("\
5630 Show displaced stepping debugging."), _("\
5631 When non-zero, displaced stepping specific debugging is enabled."),
5633 show_debug_displaced
,
5634 &setdebuglist
, &showdebuglist
);
5636 add_setshow_boolean_cmd ("non-stop", no_class
,
5638 Set whether gdb controls the inferior in non-stop mode."), _("\
5639 Show whether gdb controls the inferior in non-stop mode."), _("\
5640 When debugging a multi-threaded program and this setting is\n\
5641 off (the default, also called all-stop mode), when one thread stops\n\
5642 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
5643 all other threads in the program while you interact with the thread of\n\
5644 interest. When you continue or step a thread, you can allow the other\n\
5645 threads to run, or have them remain stopped, but while you inspect any\n\
5646 thread's state, all threads stop.\n\
5648 In non-stop mode, when one thread stops, other threads can continue\n\
5649 to run freely. You'll be able to step each thread independently,\n\
5650 leave it stopped or free to run as needed."),
5656 numsigs
= (int) TARGET_SIGNAL_LAST
;
5657 signal_stop
= (unsigned char *) xmalloc (sizeof (signal_stop
[0]) * numsigs
);
5658 signal_print
= (unsigned char *)
5659 xmalloc (sizeof (signal_print
[0]) * numsigs
);
5660 signal_program
= (unsigned char *)
5661 xmalloc (sizeof (signal_program
[0]) * numsigs
);
5662 for (i
= 0; i
< numsigs
; i
++)
5665 signal_print
[i
] = 1;
5666 signal_program
[i
] = 1;
5669 /* Signals caused by debugger's own actions
5670 should not be given to the program afterwards. */
5671 signal_program
[TARGET_SIGNAL_TRAP
] = 0;
5672 signal_program
[TARGET_SIGNAL_INT
] = 0;
5674 /* Signals that are not errors should not normally enter the debugger. */
5675 signal_stop
[TARGET_SIGNAL_ALRM
] = 0;
5676 signal_print
[TARGET_SIGNAL_ALRM
] = 0;
5677 signal_stop
[TARGET_SIGNAL_VTALRM
] = 0;
5678 signal_print
[TARGET_SIGNAL_VTALRM
] = 0;
5679 signal_stop
[TARGET_SIGNAL_PROF
] = 0;
5680 signal_print
[TARGET_SIGNAL_PROF
] = 0;
5681 signal_stop
[TARGET_SIGNAL_CHLD
] = 0;
5682 signal_print
[TARGET_SIGNAL_CHLD
] = 0;
5683 signal_stop
[TARGET_SIGNAL_IO
] = 0;
5684 signal_print
[TARGET_SIGNAL_IO
] = 0;
5685 signal_stop
[TARGET_SIGNAL_POLL
] = 0;
5686 signal_print
[TARGET_SIGNAL_POLL
] = 0;
5687 signal_stop
[TARGET_SIGNAL_URG
] = 0;
5688 signal_print
[TARGET_SIGNAL_URG
] = 0;
5689 signal_stop
[TARGET_SIGNAL_WINCH
] = 0;
5690 signal_print
[TARGET_SIGNAL_WINCH
] = 0;
5692 /* These signals are used internally by user-level thread
5693 implementations. (See signal(5) on Solaris.) Like the above
5694 signals, a healthy program receives and handles them as part of
5695 its normal operation. */
5696 signal_stop
[TARGET_SIGNAL_LWP
] = 0;
5697 signal_print
[TARGET_SIGNAL_LWP
] = 0;
5698 signal_stop
[TARGET_SIGNAL_WAITING
] = 0;
5699 signal_print
[TARGET_SIGNAL_WAITING
] = 0;
5700 signal_stop
[TARGET_SIGNAL_CANCEL
] = 0;
5701 signal_print
[TARGET_SIGNAL_CANCEL
] = 0;
5703 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
5704 &stop_on_solib_events
, _("\
5705 Set stopping for shared library events."), _("\
5706 Show stopping for shared library events."), _("\
5707 If nonzero, gdb will give control to the user when the dynamic linker\n\
5708 notifies gdb of shared library events. The most common event of interest\n\
5709 to the user would be loading/unloading of a new library."),
5711 show_stop_on_solib_events
,
5712 &setlist
, &showlist
);
5714 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
5715 follow_fork_mode_kind_names
,
5716 &follow_fork_mode_string
, _("\
5717 Set debugger response to a program call of fork or vfork."), _("\
5718 Show debugger response to a program call of fork or vfork."), _("\
5719 A fork or vfork creates a new process. follow-fork-mode can be:\n\
5720 parent - the original process is debugged after a fork\n\
5721 child - the new process is debugged after a fork\n\
5722 The unfollowed process will continue to run.\n\
5723 By default, the debugger will follow the parent process."),
5725 show_follow_fork_mode_string
,
5726 &setlist
, &showlist
);
5728 add_setshow_enum_cmd ("scheduler-locking", class_run
,
5729 scheduler_enums
, &scheduler_mode
, _("\
5730 Set mode for locking scheduler during execution."), _("\
5731 Show mode for locking scheduler during execution."), _("\
5732 off == no locking (threads may preempt at any time)\n\
5733 on == full locking (no thread except the current thread may run)\n\
5734 step == scheduler locked during every single-step operation.\n\
5735 In this mode, no other thread may run during a step command.\n\
5736 Other threads may run while stepping over a function call ('next')."),
5737 set_schedlock_func
, /* traps on target vector */
5738 show_scheduler_mode
,
5739 &setlist
, &showlist
);
5741 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
5742 Set mode of the step operation."), _("\
5743 Show mode of the step operation."), _("\
5744 When set, doing a step over a function without debug line information\n\
5745 will stop at the first instruction of that function. Otherwise, the\n\
5746 function is skipped and the step command stops at a different source line."),
5748 show_step_stop_if_no_debug
,
5749 &setlist
, &showlist
);
5751 add_setshow_enum_cmd ("displaced-stepping", class_run
,
5752 can_use_displaced_stepping_enum
,
5753 &can_use_displaced_stepping
, _("\
5754 Set debugger's willingness to use displaced stepping."), _("\
5755 Show debugger's willingness to use displaced stepping."), _("\
5756 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
5757 supported by the target architecture. If off, gdb will not use displaced\n\
5758 stepping to step over breakpoints, even if such is supported by the target\n\
5759 architecture. If auto (which is the default), gdb will use displaced stepping\n\
5760 if the target architecture supports it and non-stop mode is active, but will not\n\
5761 use it in all-stop mode (see help set non-stop)."),
5763 show_can_use_displaced_stepping
,
5764 &setlist
, &showlist
);
5766 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
5767 &exec_direction
, _("Set direction of execution.\n\
5768 Options are 'forward' or 'reverse'."),
5769 _("Show direction of execution (forward/reverse)."),
5770 _("Tells gdb whether to execute forward or backward."),
5771 set_exec_direction_func
, show_exec_direction_func
,
5772 &setlist
, &showlist
);
5774 /* ptid initializations */
5775 null_ptid
= ptid_build (0, 0, 0);
5776 minus_one_ptid
= ptid_build (-1, 0, 0);
5777 inferior_ptid
= null_ptid
;
5778 target_last_wait_ptid
= minus_one_ptid
;
5779 displaced_step_ptid
= null_ptid
;
5781 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed
);
5782 observer_attach_thread_stop_requested (infrun_thread_stop_requested
);
5783 observer_attach_thread_exit (infrun_thread_thread_exit
);
5785 /* Explicitly create without lookup, since that tries to create a
5786 value with a void typed value, and when we get here, gdbarch
5787 isn't initialized yet. At this point, we're quite sure there
5788 isn't another convenience variable of the same name. */
5789 create_internalvar_type_lazy ("_siginfo", siginfo_make_value
);