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"
52 #include "inline-frame.h"
54 /* Prototypes for local functions */
56 static void signals_info (char *, int);
58 static void handle_command (char *, int);
60 static void sig_print_info (enum target_signal
);
62 static void sig_print_header (void);
64 static void resume_cleanups (void *);
66 static int hook_stop_stub (void *);
68 static int restore_selected_frame (void *);
70 static void build_infrun (void);
72 static int follow_fork (void);
74 static void set_schedlock_func (char *args
, int from_tty
,
75 struct cmd_list_element
*c
);
77 static int currently_stepping (struct thread_info
*tp
);
79 static int currently_stepping_or_nexting_callback (struct thread_info
*tp
,
82 static void xdb_handle_command (char *args
, int from_tty
);
84 static int prepare_to_proceed (int);
86 void _initialize_infrun (void);
88 void nullify_last_target_wait_ptid (void);
90 /* When set, stop the 'step' command if we enter a function which has
91 no line number information. The normal behavior is that we step
92 over such function. */
93 int step_stop_if_no_debug
= 0;
95 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
96 struct cmd_list_element
*c
, const char *value
)
98 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
101 /* In asynchronous mode, but simulating synchronous execution. */
103 int sync_execution
= 0;
105 /* wait_for_inferior and normal_stop use this to notify the user
106 when the inferior stopped in a different thread than it had been
109 static ptid_t previous_inferior_ptid
;
111 int debug_displaced
= 0;
113 show_debug_displaced (struct ui_file
*file
, int from_tty
,
114 struct cmd_list_element
*c
, const char *value
)
116 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
119 static int debug_infrun
= 0;
121 show_debug_infrun (struct ui_file
*file
, int from_tty
,
122 struct cmd_list_element
*c
, const char *value
)
124 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
127 /* If the program uses ELF-style shared libraries, then calls to
128 functions in shared libraries go through stubs, which live in a
129 table called the PLT (Procedure Linkage Table). The first time the
130 function is called, the stub sends control to the dynamic linker,
131 which looks up the function's real address, patches the stub so
132 that future calls will go directly to the function, and then passes
133 control to the function.
135 If we are stepping at the source level, we don't want to see any of
136 this --- we just want to skip over the stub and the dynamic linker.
137 The simple approach is to single-step until control leaves the
140 However, on some systems (e.g., Red Hat's 5.2 distribution) the
141 dynamic linker calls functions in the shared C library, so you
142 can't tell from the PC alone whether the dynamic linker is still
143 running. In this case, we use a step-resume breakpoint to get us
144 past the dynamic linker, as if we were using "next" to step over a
147 in_solib_dynsym_resolve_code() says whether we're in the dynamic
148 linker code or not. Normally, this means we single-step. However,
149 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
150 address where we can place a step-resume breakpoint to get past the
151 linker's symbol resolution function.
153 in_solib_dynsym_resolve_code() can generally be implemented in a
154 pretty portable way, by comparing the PC against the address ranges
155 of the dynamic linker's sections.
157 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
158 it depends on internal details of the dynamic linker. It's usually
159 not too hard to figure out where to put a breakpoint, but it
160 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of
161 sanity checking. If it can't figure things out, returning zero and
162 getting the (possibly confusing) stepping behavior is better than
163 signalling an error, which will obscure the change in the
166 /* This function returns TRUE if pc is the address of an instruction
167 that lies within the dynamic linker (such as the event hook, or the
170 This function must be used only when a dynamic linker event has
171 been caught, and the inferior is being stepped out of the hook, or
172 undefined results are guaranteed. */
174 #ifndef SOLIB_IN_DYNAMIC_LINKER
175 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
179 /* Convert the #defines into values. This is temporary until wfi control
180 flow is completely sorted out. */
182 #ifndef CANNOT_STEP_HW_WATCHPOINTS
183 #define CANNOT_STEP_HW_WATCHPOINTS 0
185 #undef CANNOT_STEP_HW_WATCHPOINTS
186 #define CANNOT_STEP_HW_WATCHPOINTS 1
189 /* Tables of how to react to signals; the user sets them. */
191 static unsigned char *signal_stop
;
192 static unsigned char *signal_print
;
193 static unsigned char *signal_program
;
195 #define SET_SIGS(nsigs,sigs,flags) \
197 int signum = (nsigs); \
198 while (signum-- > 0) \
199 if ((sigs)[signum]) \
200 (flags)[signum] = 1; \
203 #define UNSET_SIGS(nsigs,sigs,flags) \
205 int signum = (nsigs); \
206 while (signum-- > 0) \
207 if ((sigs)[signum]) \
208 (flags)[signum] = 0; \
211 /* Value to pass to target_resume() to cause all threads to resume */
213 #define RESUME_ALL minus_one_ptid
215 /* Command list pointer for the "stop" placeholder. */
217 static struct cmd_list_element
*stop_command
;
219 /* Function inferior was in as of last step command. */
221 static struct symbol
*step_start_function
;
223 /* Nonzero if we want to give control to the user when we're notified
224 of shared library events by the dynamic linker. */
225 static int stop_on_solib_events
;
227 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
228 struct cmd_list_element
*c
, const char *value
)
230 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
234 /* Nonzero means expecting a trace trap
235 and should stop the inferior and return silently when it happens. */
239 /* Save register contents here when executing a "finish" command or are
240 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
241 Thus this contains the return value from the called function (assuming
242 values are returned in a register). */
244 struct regcache
*stop_registers
;
246 /* Nonzero after stop if current stack frame should be printed. */
248 static int stop_print_frame
;
250 /* This is a cached copy of the pid/waitstatus of the last event
251 returned by target_wait()/deprecated_target_wait_hook(). This
252 information is returned by get_last_target_status(). */
253 static ptid_t target_last_wait_ptid
;
254 static struct target_waitstatus target_last_waitstatus
;
256 static void context_switch (ptid_t ptid
);
258 void init_thread_stepping_state (struct thread_info
*tss
);
260 void init_infwait_state (void);
262 static const char follow_fork_mode_child
[] = "child";
263 static const char follow_fork_mode_parent
[] = "parent";
265 static const char *follow_fork_mode_kind_names
[] = {
266 follow_fork_mode_child
,
267 follow_fork_mode_parent
,
271 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
273 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
274 struct cmd_list_element
*c
, const char *value
)
276 fprintf_filtered (file
, _("\
277 Debugger response to a program call of fork or vfork is \"%s\".\n"),
282 /* Tell the target to follow the fork we're stopped at. Returns true
283 if the inferior should be resumed; false, if the target for some
284 reason decided it's best not to resume. */
289 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
290 int should_resume
= 1;
291 struct thread_info
*tp
;
293 /* Copy user stepping state to the new inferior thread. FIXME: the
294 followed fork child thread should have a copy of most of the
295 parent thread structure's run control related fields, not just these.
296 Initialized to avoid "may be used uninitialized" warnings from gcc. */
297 struct breakpoint
*step_resume_breakpoint
= NULL
;
298 CORE_ADDR step_range_start
= 0;
299 CORE_ADDR step_range_end
= 0;
300 struct frame_id step_frame_id
= { 0 };
305 struct target_waitstatus wait_status
;
307 /* Get the last target status returned by target_wait(). */
308 get_last_target_status (&wait_ptid
, &wait_status
);
310 /* If not stopped at a fork event, then there's nothing else to
312 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
313 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
316 /* Check if we switched over from WAIT_PTID, since the event was
318 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
319 && !ptid_equal (inferior_ptid
, wait_ptid
))
321 /* We did. Switch back to WAIT_PTID thread, to tell the
322 target to follow it (in either direction). We'll
323 afterwards refuse to resume, and inform the user what
325 switch_to_thread (wait_ptid
);
330 tp
= inferior_thread ();
332 /* If there were any forks/vforks that were caught and are now to be
333 followed, then do so now. */
334 switch (tp
->pending_follow
.kind
)
336 case TARGET_WAITKIND_FORKED
:
337 case TARGET_WAITKIND_VFORKED
:
339 ptid_t parent
, child
;
341 /* If the user did a next/step, etc, over a fork call,
342 preserve the stepping state in the fork child. */
343 if (follow_child
&& should_resume
)
345 step_resume_breakpoint
346 = clone_momentary_breakpoint (tp
->step_resume_breakpoint
);
347 step_range_start
= tp
->step_range_start
;
348 step_range_end
= tp
->step_range_end
;
349 step_frame_id
= tp
->step_frame_id
;
351 /* For now, delete the parent's sr breakpoint, otherwise,
352 parent/child sr breakpoints are considered duplicates,
353 and the child version will not be installed. Remove
354 this when the breakpoints module becomes aware of
355 inferiors and address spaces. */
356 delete_step_resume_breakpoint (tp
);
357 tp
->step_range_start
= 0;
358 tp
->step_range_end
= 0;
359 tp
->step_frame_id
= null_frame_id
;
362 parent
= inferior_ptid
;
363 child
= tp
->pending_follow
.value
.related_pid
;
365 /* Tell the target to do whatever is necessary to follow
366 either parent or child. */
367 if (target_follow_fork (follow_child
))
369 /* Target refused to follow, or there's some other reason
370 we shouldn't resume. */
375 /* This pending follow fork event is now handled, one way
376 or another. The previous selected thread may be gone
377 from the lists by now, but if it is still around, need
378 to clear the pending follow request. */
379 tp
= find_thread_ptid (parent
);
381 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
383 /* This makes sure we don't try to apply the "Switched
384 over from WAIT_PID" logic above. */
385 nullify_last_target_wait_ptid ();
387 /* If we followed the child, switch to it... */
390 switch_to_thread (child
);
392 /* ... and preserve the stepping state, in case the
393 user was stepping over the fork call. */
396 tp
= inferior_thread ();
397 tp
->step_resume_breakpoint
= step_resume_breakpoint
;
398 tp
->step_range_start
= step_range_start
;
399 tp
->step_range_end
= step_range_end
;
400 tp
->step_frame_id
= step_frame_id
;
404 /* If we get here, it was because we're trying to
405 resume from a fork catchpoint, but, the user
406 has switched threads away from the thread that
407 forked. In that case, the resume command
408 issued is most likely not applicable to the
409 child, so just warn, and refuse to resume. */
411 Not resuming: switched threads before following fork child.\n"));
414 /* Reset breakpoints in the child as appropriate. */
415 follow_inferior_reset_breakpoints ();
418 switch_to_thread (parent
);
422 case TARGET_WAITKIND_SPURIOUS
:
423 /* Nothing to follow. */
426 internal_error (__FILE__
, __LINE__
,
427 "Unexpected pending_follow.kind %d\n",
428 tp
->pending_follow
.kind
);
432 return should_resume
;
436 follow_inferior_reset_breakpoints (void)
438 struct thread_info
*tp
= inferior_thread ();
440 /* Was there a step_resume breakpoint? (There was if the user
441 did a "next" at the fork() call.) If so, explicitly reset its
444 step_resumes are a form of bp that are made to be per-thread.
445 Since we created the step_resume bp when the parent process
446 was being debugged, and now are switching to the child process,
447 from the breakpoint package's viewpoint, that's a switch of
448 "threads". We must update the bp's notion of which thread
449 it is for, or it'll be ignored when it triggers. */
451 if (tp
->step_resume_breakpoint
)
452 breakpoint_re_set_thread (tp
->step_resume_breakpoint
);
454 /* Reinsert all breakpoints in the child. The user may have set
455 breakpoints after catching the fork, in which case those
456 were never set in the child, but only in the parent. This makes
457 sure the inserted breakpoints match the breakpoint list. */
459 breakpoint_re_set ();
460 insert_breakpoints ();
463 /* EXECD_PATHNAME is assumed to be non-NULL. */
466 follow_exec (ptid_t pid
, char *execd_pathname
)
468 struct target_ops
*tgt
;
469 struct thread_info
*th
= inferior_thread ();
471 /* This is an exec event that we actually wish to pay attention to.
472 Refresh our symbol table to the newly exec'd program, remove any
475 If there are breakpoints, they aren't really inserted now,
476 since the exec() transformed our inferior into a fresh set
479 We want to preserve symbolic breakpoints on the list, since
480 we have hopes that they can be reset after the new a.out's
481 symbol table is read.
483 However, any "raw" breakpoints must be removed from the list
484 (e.g., the solib bp's), since their address is probably invalid
487 And, we DON'T want to call delete_breakpoints() here, since
488 that may write the bp's "shadow contents" (the instruction
489 value that was overwritten witha TRAP instruction). Since
490 we now have a new a.out, those shadow contents aren't valid. */
491 update_breakpoints_after_exec ();
493 /* If there was one, it's gone now. We cannot truly step-to-next
494 statement through an exec(). */
495 th
->step_resume_breakpoint
= NULL
;
496 th
->step_range_start
= 0;
497 th
->step_range_end
= 0;
499 /* The target reports the exec event to the main thread, even if
500 some other thread does the exec, and even if the main thread was
501 already stopped --- if debugging in non-stop mode, it's possible
502 the user had the main thread held stopped in the previous image
503 --- release it now. This is the same behavior as step-over-exec
504 with scheduler-locking on in all-stop mode. */
505 th
->stop_requested
= 0;
507 /* What is this a.out's name? */
508 printf_unfiltered (_("Executing new program: %s\n"), execd_pathname
);
510 /* We've followed the inferior through an exec. Therefore, the
511 inferior has essentially been killed & reborn. */
513 gdb_flush (gdb_stdout
);
515 breakpoint_init_inferior (inf_execd
);
517 if (gdb_sysroot
&& *gdb_sysroot
)
519 char *name
= alloca (strlen (gdb_sysroot
)
520 + strlen (execd_pathname
)
522 strcpy (name
, gdb_sysroot
);
523 strcat (name
, execd_pathname
);
524 execd_pathname
= name
;
527 /* That a.out is now the one to use. */
528 exec_file_attach (execd_pathname
, 0);
530 /* Reset the shared library package. This ensures that we get a
531 shlib event when the child reaches "_start", at which point the
532 dld will have had a chance to initialize the child. */
533 /* Also, loading a symbol file below may trigger symbol lookups, and
534 we don't want those to be satisfied by the libraries of the
535 previous incarnation of this process. */
536 no_shared_libraries (NULL
, 0);
538 /* Load the main file's symbols. */
539 symbol_file_add_main (execd_pathname
, 0);
541 #ifdef SOLIB_CREATE_INFERIOR_HOOK
542 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid
));
544 solib_create_inferior_hook ();
547 /* Reinsert all breakpoints. (Those which were symbolic have
548 been reset to the proper address in the new a.out, thanks
549 to symbol_file_command...) */
550 insert_breakpoints ();
552 /* The next resume of this inferior should bring it to the shlib
553 startup breakpoints. (If the user had also set bp's on
554 "main" from the old (parent) process, then they'll auto-
555 matically get reset there in the new process.) */
558 /* Non-zero if we just simulating a single-step. This is needed
559 because we cannot remove the breakpoints in the inferior process
560 until after the `wait' in `wait_for_inferior'. */
561 static int singlestep_breakpoints_inserted_p
= 0;
563 /* The thread we inserted single-step breakpoints for. */
564 static ptid_t singlestep_ptid
;
566 /* PC when we started this single-step. */
567 static CORE_ADDR singlestep_pc
;
569 /* If another thread hit the singlestep breakpoint, we save the original
570 thread here so that we can resume single-stepping it later. */
571 static ptid_t saved_singlestep_ptid
;
572 static int stepping_past_singlestep_breakpoint
;
574 /* If not equal to null_ptid, this means that after stepping over breakpoint
575 is finished, we need to switch to deferred_step_ptid, and step it.
577 The use case is when one thread has hit a breakpoint, and then the user
578 has switched to another thread and issued 'step'. We need to step over
579 breakpoint in the thread which hit the breakpoint, but then continue
580 stepping the thread user has selected. */
581 static ptid_t deferred_step_ptid
;
583 /* Displaced stepping. */
585 /* In non-stop debugging mode, we must take special care to manage
586 breakpoints properly; in particular, the traditional strategy for
587 stepping a thread past a breakpoint it has hit is unsuitable.
588 'Displaced stepping' is a tactic for stepping one thread past a
589 breakpoint it has hit while ensuring that other threads running
590 concurrently will hit the breakpoint as they should.
592 The traditional way to step a thread T off a breakpoint in a
593 multi-threaded program in all-stop mode is as follows:
595 a0) Initially, all threads are stopped, and breakpoints are not
597 a1) We single-step T, leaving breakpoints uninserted.
598 a2) We insert breakpoints, and resume all threads.
600 In non-stop debugging, however, this strategy is unsuitable: we
601 don't want to have to stop all threads in the system in order to
602 continue or step T past a breakpoint. Instead, we use displaced
605 n0) Initially, T is stopped, other threads are running, and
606 breakpoints are inserted.
607 n1) We copy the instruction "under" the breakpoint to a separate
608 location, outside the main code stream, making any adjustments
609 to the instruction, register, and memory state as directed by
611 n2) We single-step T over the instruction at its new location.
612 n3) We adjust the resulting register and memory state as directed
613 by T's architecture. This includes resetting T's PC to point
614 back into the main instruction stream.
617 This approach depends on the following gdbarch methods:
619 - gdbarch_max_insn_length and gdbarch_displaced_step_location
620 indicate where to copy the instruction, and how much space must
621 be reserved there. We use these in step n1.
623 - gdbarch_displaced_step_copy_insn copies a instruction to a new
624 address, and makes any necessary adjustments to the instruction,
625 register contents, and memory. We use this in step n1.
627 - gdbarch_displaced_step_fixup adjusts registers and memory after
628 we have successfuly single-stepped the instruction, to yield the
629 same effect the instruction would have had if we had executed it
630 at its original address. We use this in step n3.
632 - gdbarch_displaced_step_free_closure provides cleanup.
634 The gdbarch_displaced_step_copy_insn and
635 gdbarch_displaced_step_fixup functions must be written so that
636 copying an instruction with gdbarch_displaced_step_copy_insn,
637 single-stepping across the copied instruction, and then applying
638 gdbarch_displaced_insn_fixup should have the same effects on the
639 thread's memory and registers as stepping the instruction in place
640 would have. Exactly which responsibilities fall to the copy and
641 which fall to the fixup is up to the author of those functions.
643 See the comments in gdbarch.sh for details.
645 Note that displaced stepping and software single-step cannot
646 currently be used in combination, although with some care I think
647 they could be made to. Software single-step works by placing
648 breakpoints on all possible subsequent instructions; if the
649 displaced instruction is a PC-relative jump, those breakpoints
650 could fall in very strange places --- on pages that aren't
651 executable, or at addresses that are not proper instruction
652 boundaries. (We do generally let other threads run while we wait
653 to hit the software single-step breakpoint, and they might
654 encounter such a corrupted instruction.) One way to work around
655 this would be to have gdbarch_displaced_step_copy_insn fully
656 simulate the effect of PC-relative instructions (and return NULL)
657 on architectures that use software single-stepping.
659 In non-stop mode, we can have independent and simultaneous step
660 requests, so more than one thread may need to simultaneously step
661 over a breakpoint. The current implementation assumes there is
662 only one scratch space per process. In this case, we have to
663 serialize access to the scratch space. If thread A wants to step
664 over a breakpoint, but we are currently waiting for some other
665 thread to complete a displaced step, we leave thread A stopped and
666 place it in the displaced_step_request_queue. Whenever a displaced
667 step finishes, we pick the next thread in the queue and start a new
668 displaced step operation on it. See displaced_step_prepare and
669 displaced_step_fixup for details. */
671 /* If this is not null_ptid, this is the thread carrying out a
672 displaced single-step. This thread's state will require fixing up
673 once it has completed its step. */
674 static ptid_t displaced_step_ptid
;
676 struct displaced_step_request
679 struct displaced_step_request
*next
;
682 /* A queue of pending displaced stepping requests. */
683 struct displaced_step_request
*displaced_step_request_queue
;
685 /* The architecture the thread had when we stepped it. */
686 static struct gdbarch
*displaced_step_gdbarch
;
688 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
689 for post-step cleanup. */
690 static struct displaced_step_closure
*displaced_step_closure
;
692 /* The address of the original instruction, and the copy we made. */
693 static CORE_ADDR displaced_step_original
, displaced_step_copy
;
695 /* Saved contents of copy area. */
696 static gdb_byte
*displaced_step_saved_copy
;
698 /* Enum strings for "set|show displaced-stepping". */
700 static const char can_use_displaced_stepping_auto
[] = "auto";
701 static const char can_use_displaced_stepping_on
[] = "on";
702 static const char can_use_displaced_stepping_off
[] = "off";
703 static const char *can_use_displaced_stepping_enum
[] =
705 can_use_displaced_stepping_auto
,
706 can_use_displaced_stepping_on
,
707 can_use_displaced_stepping_off
,
711 /* If ON, and the architecture supports it, GDB will use displaced
712 stepping to step over breakpoints. If OFF, or if the architecture
713 doesn't support it, GDB will instead use the traditional
714 hold-and-step approach. If AUTO (which is the default), GDB will
715 decide which technique to use to step over breakpoints depending on
716 which of all-stop or non-stop mode is active --- displaced stepping
717 in non-stop mode; hold-and-step in all-stop mode. */
719 static const char *can_use_displaced_stepping
=
720 can_use_displaced_stepping_auto
;
723 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
724 struct cmd_list_element
*c
,
727 if (can_use_displaced_stepping
== can_use_displaced_stepping_auto
)
728 fprintf_filtered (file
, _("\
729 Debugger's willingness to use displaced stepping to step over \
730 breakpoints is %s (currently %s).\n"),
731 value
, non_stop
? "on" : "off");
733 fprintf_filtered (file
, _("\
734 Debugger's willingness to use displaced stepping to step over \
735 breakpoints is %s.\n"), value
);
738 /* Return non-zero if displaced stepping can/should be used to step
742 use_displaced_stepping (struct gdbarch
*gdbarch
)
744 return (((can_use_displaced_stepping
== can_use_displaced_stepping_auto
746 || can_use_displaced_stepping
== can_use_displaced_stepping_on
)
747 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
751 /* Clean out any stray displaced stepping state. */
753 displaced_step_clear (void)
755 /* Indicate that there is no cleanup pending. */
756 displaced_step_ptid
= null_ptid
;
758 if (displaced_step_closure
)
760 gdbarch_displaced_step_free_closure (displaced_step_gdbarch
,
761 displaced_step_closure
);
762 displaced_step_closure
= NULL
;
767 displaced_step_clear_cleanup (void *ignore
)
769 displaced_step_clear ();
772 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
774 displaced_step_dump_bytes (struct ui_file
*file
,
780 for (i
= 0; i
< len
; i
++)
781 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
782 fputs_unfiltered ("\n", file
);
785 /* Prepare to single-step, using displaced stepping.
787 Note that we cannot use displaced stepping when we have a signal to
788 deliver. If we have a signal to deliver and an instruction to step
789 over, then after the step, there will be no indication from the
790 target whether the thread entered a signal handler or ignored the
791 signal and stepped over the instruction successfully --- both cases
792 result in a simple SIGTRAP. In the first case we mustn't do a
793 fixup, and in the second case we must --- but we can't tell which.
794 Comments in the code for 'random signals' in handle_inferior_event
795 explain how we handle this case instead.
797 Returns 1 if preparing was successful -- this thread is going to be
798 stepped now; or 0 if displaced stepping this thread got queued. */
800 displaced_step_prepare (ptid_t ptid
)
802 struct cleanup
*old_cleanups
, *ignore_cleanups
;
803 struct regcache
*regcache
= get_thread_regcache (ptid
);
804 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
805 CORE_ADDR original
, copy
;
807 struct displaced_step_closure
*closure
;
809 /* We should never reach this function if the architecture does not
810 support displaced stepping. */
811 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
813 /* For the first cut, we're displaced stepping one thread at a
816 if (!ptid_equal (displaced_step_ptid
, null_ptid
))
818 /* Already waiting for a displaced step to finish. Defer this
819 request and place in queue. */
820 struct displaced_step_request
*req
, *new_req
;
823 fprintf_unfiltered (gdb_stdlog
,
824 "displaced: defering step of %s\n",
825 target_pid_to_str (ptid
));
827 new_req
= xmalloc (sizeof (*new_req
));
828 new_req
->ptid
= ptid
;
829 new_req
->next
= NULL
;
831 if (displaced_step_request_queue
)
833 for (req
= displaced_step_request_queue
;
840 displaced_step_request_queue
= new_req
;
847 fprintf_unfiltered (gdb_stdlog
,
848 "displaced: stepping %s now\n",
849 target_pid_to_str (ptid
));
852 displaced_step_clear ();
854 old_cleanups
= save_inferior_ptid ();
855 inferior_ptid
= ptid
;
857 original
= regcache_read_pc (regcache
);
859 copy
= gdbarch_displaced_step_location (gdbarch
);
860 len
= gdbarch_max_insn_length (gdbarch
);
862 /* Save the original contents of the copy area. */
863 displaced_step_saved_copy
= xmalloc (len
);
864 ignore_cleanups
= make_cleanup (free_current_contents
,
865 &displaced_step_saved_copy
);
866 read_memory (copy
, displaced_step_saved_copy
, len
);
869 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
870 paddress (gdbarch
, copy
));
871 displaced_step_dump_bytes (gdb_stdlog
, displaced_step_saved_copy
, len
);
874 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
875 original
, copy
, regcache
);
877 /* We don't support the fully-simulated case at present. */
878 gdb_assert (closure
);
880 /* Save the information we need to fix things up if the step
882 displaced_step_ptid
= ptid
;
883 displaced_step_gdbarch
= gdbarch
;
884 displaced_step_closure
= closure
;
885 displaced_step_original
= original
;
886 displaced_step_copy
= copy
;
888 make_cleanup (displaced_step_clear_cleanup
, 0);
890 /* Resume execution at the copy. */
891 regcache_write_pc (regcache
, copy
);
893 discard_cleanups (ignore_cleanups
);
895 do_cleanups (old_cleanups
);
898 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
899 paddress (gdbarch
, copy
));
905 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
, const gdb_byte
*myaddr
, int len
)
907 struct cleanup
*ptid_cleanup
= save_inferior_ptid ();
908 inferior_ptid
= ptid
;
909 write_memory (memaddr
, myaddr
, len
);
910 do_cleanups (ptid_cleanup
);
914 displaced_step_fixup (ptid_t event_ptid
, enum target_signal signal
)
916 struct cleanup
*old_cleanups
;
918 /* Was this event for the pid we displaced? */
919 if (ptid_equal (displaced_step_ptid
, null_ptid
)
920 || ! ptid_equal (displaced_step_ptid
, event_ptid
))
923 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, 0);
925 /* Restore the contents of the copy area. */
927 ULONGEST len
= gdbarch_max_insn_length (displaced_step_gdbarch
);
928 write_memory_ptid (displaced_step_ptid
, displaced_step_copy
,
929 displaced_step_saved_copy
, len
);
931 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s\n",
932 paddress (displaced_step_gdbarch
,
933 displaced_step_copy
));
936 /* Did the instruction complete successfully? */
937 if (signal
== TARGET_SIGNAL_TRAP
)
939 /* Fix up the resulting state. */
940 gdbarch_displaced_step_fixup (displaced_step_gdbarch
,
941 displaced_step_closure
,
942 displaced_step_original
,
944 get_thread_regcache (displaced_step_ptid
));
948 /* Since the instruction didn't complete, all we can do is
950 struct regcache
*regcache
= get_thread_regcache (event_ptid
);
951 CORE_ADDR pc
= regcache_read_pc (regcache
);
952 pc
= displaced_step_original
+ (pc
- displaced_step_copy
);
953 regcache_write_pc (regcache
, pc
);
956 do_cleanups (old_cleanups
);
958 displaced_step_ptid
= null_ptid
;
960 /* Are there any pending displaced stepping requests? If so, run
962 while (displaced_step_request_queue
)
964 struct displaced_step_request
*head
;
966 struct regcache
*regcache
;
967 struct gdbarch
*gdbarch
;
970 head
= displaced_step_request_queue
;
972 displaced_step_request_queue
= head
->next
;
975 context_switch (ptid
);
977 regcache
= get_thread_regcache (ptid
);
978 actual_pc
= regcache_read_pc (regcache
);
980 if (breakpoint_here_p (actual_pc
))
983 fprintf_unfiltered (gdb_stdlog
,
984 "displaced: stepping queued %s now\n",
985 target_pid_to_str (ptid
));
987 displaced_step_prepare (ptid
);
989 gdbarch
= get_regcache_arch (regcache
);
993 CORE_ADDR actual_pc
= regcache_read_pc (regcache
);
996 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
997 paddress (gdbarch
, actual_pc
));
998 read_memory (actual_pc
, buf
, sizeof (buf
));
999 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
1002 if (gdbarch_software_single_step_p (gdbarch
))
1003 target_resume (ptid
, 0, TARGET_SIGNAL_0
);
1005 target_resume (ptid
, 1, TARGET_SIGNAL_0
);
1007 /* Done, we're stepping a thread. */
1013 struct thread_info
*tp
= inferior_thread ();
1015 /* The breakpoint we were sitting under has since been
1017 tp
->trap_expected
= 0;
1019 /* Go back to what we were trying to do. */
1020 step
= currently_stepping (tp
);
1022 if (debug_displaced
)
1023 fprintf_unfiltered (gdb_stdlog
, "breakpoint is gone %s: step(%d)\n",
1024 target_pid_to_str (tp
->ptid
), step
);
1026 target_resume (ptid
, step
, TARGET_SIGNAL_0
);
1027 tp
->stop_signal
= TARGET_SIGNAL_0
;
1029 /* This request was discarded. See if there's any other
1030 thread waiting for its turn. */
1035 /* Update global variables holding ptids to hold NEW_PTID if they were
1036 holding OLD_PTID. */
1038 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
1040 struct displaced_step_request
*it
;
1042 if (ptid_equal (inferior_ptid
, old_ptid
))
1043 inferior_ptid
= new_ptid
;
1045 if (ptid_equal (singlestep_ptid
, old_ptid
))
1046 singlestep_ptid
= new_ptid
;
1048 if (ptid_equal (displaced_step_ptid
, old_ptid
))
1049 displaced_step_ptid
= new_ptid
;
1051 if (ptid_equal (deferred_step_ptid
, old_ptid
))
1052 deferred_step_ptid
= new_ptid
;
1054 for (it
= displaced_step_request_queue
; it
; it
= it
->next
)
1055 if (ptid_equal (it
->ptid
, old_ptid
))
1056 it
->ptid
= new_ptid
;
1062 /* Things to clean up if we QUIT out of resume (). */
1064 resume_cleanups (void *ignore
)
1069 static const char schedlock_off
[] = "off";
1070 static const char schedlock_on
[] = "on";
1071 static const char schedlock_step
[] = "step";
1072 static const char *scheduler_enums
[] = {
1078 static const char *scheduler_mode
= schedlock_off
;
1080 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
1081 struct cmd_list_element
*c
, const char *value
)
1083 fprintf_filtered (file
, _("\
1084 Mode for locking scheduler during execution is \"%s\".\n"),
1089 set_schedlock_func (char *args
, int from_tty
, struct cmd_list_element
*c
)
1091 if (!target_can_lock_scheduler
)
1093 scheduler_mode
= schedlock_off
;
1094 error (_("Target '%s' cannot support this command."), target_shortname
);
1098 /* True if execution commands resume all threads of all processes by
1099 default; otherwise, resume only threads of the current inferior
1101 int sched_multi
= 0;
1103 /* Try to setup for software single stepping over the specified location.
1104 Return 1 if target_resume() should use hardware single step.
1106 GDBARCH the current gdbarch.
1107 PC the location to step over. */
1110 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
1114 if (gdbarch_software_single_step_p (gdbarch
))
1116 if (use_displaced_stepping (gdbarch
))
1118 else if (gdbarch_software_single_step (gdbarch
, get_current_frame ()))
1121 /* Do not pull these breakpoints until after a `wait' in
1122 `wait_for_inferior' */
1123 singlestep_breakpoints_inserted_p
= 1;
1124 singlestep_ptid
= inferior_ptid
;
1131 /* Resume the inferior, but allow a QUIT. This is useful if the user
1132 wants to interrupt some lengthy single-stepping operation
1133 (for child processes, the SIGINT goes to the inferior, and so
1134 we get a SIGINT random_signal, but for remote debugging and perhaps
1135 other targets, that's not true).
1137 STEP nonzero if we should step (zero to continue instead).
1138 SIG is the signal to give the inferior (zero for none). */
1140 resume (int step
, enum target_signal sig
)
1142 int should_resume
= 1;
1143 struct cleanup
*old_cleanups
= make_cleanup (resume_cleanups
, 0);
1144 struct regcache
*regcache
= get_current_regcache ();
1145 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
1146 struct thread_info
*tp
= inferior_thread ();
1147 CORE_ADDR pc
= regcache_read_pc (regcache
);
1152 fprintf_unfiltered (gdb_stdlog
,
1153 "infrun: resume (step=%d, signal=%d), "
1154 "trap_expected=%d\n",
1155 step
, sig
, tp
->trap_expected
);
1157 /* Some targets (e.g. Solaris x86) have a kernel bug when stepping
1158 over an instruction that causes a page fault without triggering
1159 a hardware watchpoint. The kernel properly notices that it shouldn't
1160 stop, because the hardware watchpoint is not triggered, but it forgets
1161 the step request and continues the program normally.
1162 Work around the problem by removing hardware watchpoints if a step is
1163 requested, GDB will check for a hardware watchpoint trigger after the
1165 if (CANNOT_STEP_HW_WATCHPOINTS
&& step
)
1166 remove_hw_watchpoints ();
1169 /* Normally, by the time we reach `resume', the breakpoints are either
1170 removed or inserted, as appropriate. The exception is if we're sitting
1171 at a permanent breakpoint; we need to step over it, but permanent
1172 breakpoints can't be removed. So we have to test for it here. */
1173 if (breakpoint_here_p (pc
) == permanent_breakpoint_here
)
1175 if (gdbarch_skip_permanent_breakpoint_p (gdbarch
))
1176 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
1179 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1180 how to step past a permanent breakpoint on this architecture. Try using\n\
1181 a command like `return' or `jump' to continue execution."));
1184 /* If enabled, step over breakpoints by executing a copy of the
1185 instruction at a different address.
1187 We can't use displaced stepping when we have a signal to deliver;
1188 the comments for displaced_step_prepare explain why. The
1189 comments in the handle_inferior event for dealing with 'random
1190 signals' explain what we do instead. */
1191 if (use_displaced_stepping (gdbarch
)
1192 && (tp
->trap_expected
1193 || (step
&& gdbarch_software_single_step_p (gdbarch
)))
1194 && sig
== TARGET_SIGNAL_0
)
1196 if (!displaced_step_prepare (inferior_ptid
))
1198 /* Got placed in displaced stepping queue. Will be resumed
1199 later when all the currently queued displaced stepping
1200 requests finish. The thread is not executing at this point,
1201 and the call to set_executing will be made later. But we
1202 need to call set_running here, since from frontend point of view,
1203 the thread is running. */
1204 set_running (inferior_ptid
, 1);
1205 discard_cleanups (old_cleanups
);
1210 /* Do we need to do it the hard way, w/temp breakpoints? */
1212 step
= maybe_software_singlestep (gdbarch
, pc
);
1218 /* If STEP is set, it's a request to use hardware stepping
1219 facilities. But in that case, we should never
1220 use singlestep breakpoint. */
1221 gdb_assert (!(singlestep_breakpoints_inserted_p
&& step
));
1223 /* Decide the set of threads to ask the target to resume. Start
1224 by assuming everything will be resumed, than narrow the set
1225 by applying increasingly restricting conditions. */
1227 /* By default, resume all threads of all processes. */
1228 resume_ptid
= RESUME_ALL
;
1230 /* Maybe resume only all threads of the current process. */
1231 if (!sched_multi
&& target_supports_multi_process ())
1233 resume_ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
1236 /* Maybe resume a single thread after all. */
1237 if (singlestep_breakpoints_inserted_p
1238 && stepping_past_singlestep_breakpoint
)
1240 /* The situation here is as follows. In thread T1 we wanted to
1241 single-step. Lacking hardware single-stepping we've
1242 set breakpoint at the PC of the next instruction -- call it
1243 P. After resuming, we've hit that breakpoint in thread T2.
1244 Now we've removed original breakpoint, inserted breakpoint
1245 at P+1, and try to step to advance T2 past breakpoint.
1246 We need to step only T2, as if T1 is allowed to freely run,
1247 it can run past P, and if other threads are allowed to run,
1248 they can hit breakpoint at P+1, and nested hits of single-step
1249 breakpoints is not something we'd want -- that's complicated
1250 to support, and has no value. */
1251 resume_ptid
= inferior_ptid
;
1253 else if ((step
|| singlestep_breakpoints_inserted_p
)
1254 && tp
->trap_expected
)
1256 /* We're allowing a thread to run past a breakpoint it has
1257 hit, by single-stepping the thread with the breakpoint
1258 removed. In which case, we need to single-step only this
1259 thread, and keep others stopped, as they can miss this
1260 breakpoint if allowed to run.
1262 The current code actually removes all breakpoints when
1263 doing this, not just the one being stepped over, so if we
1264 let other threads run, we can actually miss any
1265 breakpoint, not just the one at PC. */
1266 resume_ptid
= inferior_ptid
;
1270 /* With non-stop mode on, threads are always handled
1272 resume_ptid
= inferior_ptid
;
1274 else if ((scheduler_mode
== schedlock_on
)
1275 || (scheduler_mode
== schedlock_step
1276 && (step
|| singlestep_breakpoints_inserted_p
)))
1278 /* User-settable 'scheduler' mode requires solo thread resume. */
1279 resume_ptid
= inferior_ptid
;
1282 if (gdbarch_cannot_step_breakpoint (gdbarch
))
1284 /* Most targets can step a breakpoint instruction, thus
1285 executing it normally. But if this one cannot, just
1286 continue and we will hit it anyway. */
1287 if (step
&& breakpoint_inserted_here_p (pc
))
1292 && use_displaced_stepping (gdbarch
)
1293 && tp
->trap_expected
)
1295 struct regcache
*resume_regcache
= get_thread_regcache (resume_ptid
);
1296 struct gdbarch
*resume_gdbarch
= get_regcache_arch (resume_regcache
);
1297 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
1300 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
1301 paddress (resume_gdbarch
, actual_pc
));
1302 read_memory (actual_pc
, buf
, sizeof (buf
));
1303 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
1306 /* Install inferior's terminal modes. */
1307 target_terminal_inferior ();
1309 /* Avoid confusing the next resume, if the next stop/resume
1310 happens to apply to another thread. */
1311 tp
->stop_signal
= TARGET_SIGNAL_0
;
1313 target_resume (resume_ptid
, step
, sig
);
1316 discard_cleanups (old_cleanups
);
1321 /* Clear out all variables saying what to do when inferior is continued.
1322 First do this, then set the ones you want, then call `proceed'. */
1325 clear_proceed_status_thread (struct thread_info
*tp
)
1328 fprintf_unfiltered (gdb_stdlog
,
1329 "infrun: clear_proceed_status_thread (%s)\n",
1330 target_pid_to_str (tp
->ptid
));
1332 tp
->trap_expected
= 0;
1333 tp
->step_range_start
= 0;
1334 tp
->step_range_end
= 0;
1335 tp
->step_frame_id
= null_frame_id
;
1336 tp
->step_stack_frame_id
= null_frame_id
;
1337 tp
->step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
1338 tp
->stop_requested
= 0;
1342 tp
->proceed_to_finish
= 0;
1344 /* Discard any remaining commands or status from previous stop. */
1345 bpstat_clear (&tp
->stop_bpstat
);
1349 clear_proceed_status_callback (struct thread_info
*tp
, void *data
)
1351 if (is_exited (tp
->ptid
))
1354 clear_proceed_status_thread (tp
);
1359 clear_proceed_status (void)
1361 if (!ptid_equal (inferior_ptid
, null_ptid
))
1363 struct inferior
*inferior
;
1367 /* If in non-stop mode, only delete the per-thread status
1368 of the current thread. */
1369 clear_proceed_status_thread (inferior_thread ());
1373 /* In all-stop mode, delete the per-thread status of
1375 iterate_over_threads (clear_proceed_status_callback
, NULL
);
1378 inferior
= current_inferior ();
1379 inferior
->stop_soon
= NO_STOP_QUIETLY
;
1382 stop_after_trap
= 0;
1384 observer_notify_about_to_proceed ();
1388 regcache_xfree (stop_registers
);
1389 stop_registers
= NULL
;
1393 /* Check the current thread against the thread that reported the most recent
1394 event. If a step-over is required return TRUE and set the current thread
1395 to the old thread. Otherwise return FALSE.
1397 This should be suitable for any targets that support threads. */
1400 prepare_to_proceed (int step
)
1403 struct target_waitstatus wait_status
;
1404 int schedlock_enabled
;
1406 /* With non-stop mode on, threads are always handled individually. */
1407 gdb_assert (! non_stop
);
1409 /* Get the last target status returned by target_wait(). */
1410 get_last_target_status (&wait_ptid
, &wait_status
);
1412 /* Make sure we were stopped at a breakpoint. */
1413 if (wait_status
.kind
!= TARGET_WAITKIND_STOPPED
1414 || wait_status
.value
.sig
!= TARGET_SIGNAL_TRAP
)
1419 schedlock_enabled
= (scheduler_mode
== schedlock_on
1420 || (scheduler_mode
== schedlock_step
1423 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
1424 if (schedlock_enabled
)
1427 /* Don't switch over if we're about to resume some other process
1428 other than WAIT_PTID's, and schedule-multiple is off. */
1430 && ptid_get_pid (wait_ptid
) != ptid_get_pid (inferior_ptid
))
1433 /* Switched over from WAIT_PID. */
1434 if (!ptid_equal (wait_ptid
, minus_one_ptid
)
1435 && !ptid_equal (inferior_ptid
, wait_ptid
))
1437 struct regcache
*regcache
= get_thread_regcache (wait_ptid
);
1439 if (breakpoint_here_p (regcache_read_pc (regcache
)))
1441 /* If stepping, remember current thread to switch back to. */
1443 deferred_step_ptid
= inferior_ptid
;
1445 /* Switch back to WAIT_PID thread. */
1446 switch_to_thread (wait_ptid
);
1448 /* We return 1 to indicate that there is a breakpoint here,
1449 so we need to step over it before continuing to avoid
1450 hitting it straight away. */
1458 /* Basic routine for continuing the program in various fashions.
1460 ADDR is the address to resume at, or -1 for resume where stopped.
1461 SIGGNAL is the signal to give it, or 0 for none,
1462 or -1 for act according to how it stopped.
1463 STEP is nonzero if should trap after one instruction.
1464 -1 means return after that and print nothing.
1465 You should probably set various step_... variables
1466 before calling here, if you are stepping.
1468 You should call clear_proceed_status before calling proceed. */
1471 proceed (CORE_ADDR addr
, enum target_signal siggnal
, int step
)
1473 struct regcache
*regcache
;
1474 struct gdbarch
*gdbarch
;
1475 struct thread_info
*tp
;
1479 /* If we're stopped at a fork/vfork, follow the branch set by the
1480 "set follow-fork-mode" command; otherwise, we'll just proceed
1481 resuming the current thread. */
1482 if (!follow_fork ())
1484 /* The target for some reason decided not to resume. */
1489 regcache
= get_current_regcache ();
1490 gdbarch
= get_regcache_arch (regcache
);
1491 pc
= regcache_read_pc (regcache
);
1494 step_start_function
= find_pc_function (pc
);
1496 stop_after_trap
= 1;
1498 if (addr
== (CORE_ADDR
) -1)
1500 if (pc
== stop_pc
&& breakpoint_here_p (pc
)
1501 && execution_direction
!= EXEC_REVERSE
)
1502 /* There is a breakpoint at the address we will resume at,
1503 step one instruction before inserting breakpoints so that
1504 we do not stop right away (and report a second hit at this
1507 Note, we don't do this in reverse, because we won't
1508 actually be executing the breakpoint insn anyway.
1509 We'll be (un-)executing the previous instruction. */
1512 else if (gdbarch_single_step_through_delay_p (gdbarch
)
1513 && gdbarch_single_step_through_delay (gdbarch
,
1514 get_current_frame ()))
1515 /* We stepped onto an instruction that needs to be stepped
1516 again before re-inserting the breakpoint, do so. */
1521 regcache_write_pc (regcache
, addr
);
1525 fprintf_unfiltered (gdb_stdlog
,
1526 "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
1527 paddress (gdbarch
, addr
), siggnal
, step
);
1530 /* In non-stop, each thread is handled individually. The context
1531 must already be set to the right thread here. */
1535 /* In a multi-threaded task we may select another thread and
1536 then continue or step.
1538 But if the old thread was stopped at a breakpoint, it will
1539 immediately cause another breakpoint stop without any
1540 execution (i.e. it will report a breakpoint hit incorrectly).
1541 So we must step over it first.
1543 prepare_to_proceed checks the current thread against the
1544 thread that reported the most recent event. If a step-over
1545 is required it returns TRUE and sets the current thread to
1547 if (prepare_to_proceed (step
))
1551 /* prepare_to_proceed may change the current thread. */
1552 tp
= inferior_thread ();
1556 tp
->trap_expected
= 1;
1557 /* If displaced stepping is enabled, we can step over the
1558 breakpoint without hitting it, so leave all breakpoints
1559 inserted. Otherwise we need to disable all breakpoints, step
1560 one instruction, and then re-add them when that step is
1562 if (!use_displaced_stepping (gdbarch
))
1563 remove_breakpoints ();
1566 /* We can insert breakpoints if we're not trying to step over one,
1567 or if we are stepping over one but we're using displaced stepping
1569 if (! tp
->trap_expected
|| use_displaced_stepping (gdbarch
))
1570 insert_breakpoints ();
1574 /* Pass the last stop signal to the thread we're resuming,
1575 irrespective of whether the current thread is the thread that
1576 got the last event or not. This was historically GDB's
1577 behaviour before keeping a stop_signal per thread. */
1579 struct thread_info
*last_thread
;
1581 struct target_waitstatus last_status
;
1583 get_last_target_status (&last_ptid
, &last_status
);
1584 if (!ptid_equal (inferior_ptid
, last_ptid
)
1585 && !ptid_equal (last_ptid
, null_ptid
)
1586 && !ptid_equal (last_ptid
, minus_one_ptid
))
1588 last_thread
= find_thread_ptid (last_ptid
);
1591 tp
->stop_signal
= last_thread
->stop_signal
;
1592 last_thread
->stop_signal
= TARGET_SIGNAL_0
;
1597 if (siggnal
!= TARGET_SIGNAL_DEFAULT
)
1598 tp
->stop_signal
= siggnal
;
1599 /* If this signal should not be seen by program,
1600 give it zero. Used for debugging signals. */
1601 else if (!signal_program
[tp
->stop_signal
])
1602 tp
->stop_signal
= TARGET_SIGNAL_0
;
1604 annotate_starting ();
1606 /* Make sure that output from GDB appears before output from the
1608 gdb_flush (gdb_stdout
);
1610 /* Refresh prev_pc value just prior to resuming. This used to be
1611 done in stop_stepping, however, setting prev_pc there did not handle
1612 scenarios such as inferior function calls or returning from
1613 a function via the return command. In those cases, the prev_pc
1614 value was not set properly for subsequent commands. The prev_pc value
1615 is used to initialize the starting line number in the ecs. With an
1616 invalid value, the gdb next command ends up stopping at the position
1617 represented by the next line table entry past our start position.
1618 On platforms that generate one line table entry per line, this
1619 is not a problem. However, on the ia64, the compiler generates
1620 extraneous line table entries that do not increase the line number.
1621 When we issue the gdb next command on the ia64 after an inferior call
1622 or a return command, we often end up a few instructions forward, still
1623 within the original line we started.
1625 An attempt was made to have init_execution_control_state () refresh
1626 the prev_pc value before calculating the line number. This approach
1627 did not work because on platforms that use ptrace, the pc register
1628 cannot be read unless the inferior is stopped. At that point, we
1629 are not guaranteed the inferior is stopped and so the regcache_read_pc ()
1630 call can fail. Setting the prev_pc value here ensures the value is
1631 updated correctly when the inferior is stopped. */
1632 tp
->prev_pc
= regcache_read_pc (get_current_regcache ());
1634 /* Fill in with reasonable starting values. */
1635 init_thread_stepping_state (tp
);
1637 /* Reset to normal state. */
1638 init_infwait_state ();
1640 /* Resume inferior. */
1641 resume (oneproc
|| step
|| bpstat_should_step (), tp
->stop_signal
);
1643 /* Wait for it to stop (if not standalone)
1644 and in any case decode why it stopped, and act accordingly. */
1645 /* Do this only if we are not using the event loop, or if the target
1646 does not support asynchronous execution. */
1647 if (!target_can_async_p ())
1649 wait_for_inferior (0);
1655 /* Start remote-debugging of a machine over a serial link. */
1658 start_remote (int from_tty
)
1660 struct inferior
*inferior
;
1661 init_wait_for_inferior ();
1663 inferior
= current_inferior ();
1664 inferior
->stop_soon
= STOP_QUIETLY_REMOTE
;
1666 /* Always go on waiting for the target, regardless of the mode. */
1667 /* FIXME: cagney/1999-09-23: At present it isn't possible to
1668 indicate to wait_for_inferior that a target should timeout if
1669 nothing is returned (instead of just blocking). Because of this,
1670 targets expecting an immediate response need to, internally, set
1671 things up so that the target_wait() is forced to eventually
1673 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
1674 differentiate to its caller what the state of the target is after
1675 the initial open has been performed. Here we're assuming that
1676 the target has stopped. It should be possible to eventually have
1677 target_open() return to the caller an indication that the target
1678 is currently running and GDB state should be set to the same as
1679 for an async run. */
1680 wait_for_inferior (0);
1682 /* Now that the inferior has stopped, do any bookkeeping like
1683 loading shared libraries. We want to do this before normal_stop,
1684 so that the displayed frame is up to date. */
1685 post_create_inferior (¤t_target
, from_tty
);
1690 /* Initialize static vars when a new inferior begins. */
1693 init_wait_for_inferior (void)
1695 /* These are meaningless until the first time through wait_for_inferior. */
1697 breakpoint_init_inferior (inf_starting
);
1699 clear_proceed_status ();
1701 stepping_past_singlestep_breakpoint
= 0;
1702 deferred_step_ptid
= null_ptid
;
1704 target_last_wait_ptid
= minus_one_ptid
;
1706 previous_inferior_ptid
= null_ptid
;
1707 init_infwait_state ();
1709 displaced_step_clear ();
1711 /* Discard any skipped inlined frames. */
1712 clear_inline_frame_state (minus_one_ptid
);
1716 /* This enum encodes possible reasons for doing a target_wait, so that
1717 wfi can call target_wait in one place. (Ultimately the call will be
1718 moved out of the infinite loop entirely.) */
1722 infwait_normal_state
,
1723 infwait_thread_hop_state
,
1724 infwait_step_watch_state
,
1725 infwait_nonstep_watch_state
1728 /* Why did the inferior stop? Used to print the appropriate messages
1729 to the interface from within handle_inferior_event(). */
1730 enum inferior_stop_reason
1732 /* Step, next, nexti, stepi finished. */
1734 /* Inferior terminated by signal. */
1736 /* Inferior exited. */
1738 /* Inferior received signal, and user asked to be notified. */
1740 /* Reverse execution -- target ran out of history info. */
1744 /* The PTID we'll do a target_wait on.*/
1747 /* Current inferior wait state. */
1748 enum infwait_states infwait_state
;
1750 /* Data to be passed around while handling an event. This data is
1751 discarded between events. */
1752 struct execution_control_state
1755 /* The thread that got the event, if this was a thread event; NULL
1757 struct thread_info
*event_thread
;
1759 struct target_waitstatus ws
;
1761 CORE_ADDR stop_func_start
;
1762 CORE_ADDR stop_func_end
;
1763 char *stop_func_name
;
1764 int new_thread_event
;
1768 static void init_execution_control_state (struct execution_control_state
*ecs
);
1770 static void handle_inferior_event (struct execution_control_state
*ecs
);
1772 static void handle_step_into_function (struct gdbarch
*gdbarch
,
1773 struct execution_control_state
*ecs
);
1774 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
1775 struct execution_control_state
*ecs
);
1776 static void insert_step_resume_breakpoint_at_frame (struct frame_info
*step_frame
);
1777 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
1778 static void insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
1779 struct symtab_and_line sr_sal
,
1780 struct frame_id sr_id
);
1781 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
1783 static void stop_stepping (struct execution_control_state
*ecs
);
1784 static void prepare_to_wait (struct execution_control_state
*ecs
);
1785 static void keep_going (struct execution_control_state
*ecs
);
1786 static void print_stop_reason (enum inferior_stop_reason stop_reason
,
1789 /* Callback for iterate over threads. If the thread is stopped, but
1790 the user/frontend doesn't know about that yet, go through
1791 normal_stop, as if the thread had just stopped now. ARG points at
1792 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
1793 ptid_is_pid(PTID) is true, applies to all threads of the process
1794 pointed at by PTID. Otherwise, apply only to the thread pointed by
1798 infrun_thread_stop_requested_callback (struct thread_info
*info
, void *arg
)
1800 ptid_t ptid
= * (ptid_t
*) arg
;
1802 if ((ptid_equal (info
->ptid
, ptid
)
1803 || ptid_equal (minus_one_ptid
, ptid
)
1804 || (ptid_is_pid (ptid
)
1805 && ptid_get_pid (ptid
) == ptid_get_pid (info
->ptid
)))
1806 && is_running (info
->ptid
)
1807 && !is_executing (info
->ptid
))
1809 struct cleanup
*old_chain
;
1810 struct execution_control_state ecss
;
1811 struct execution_control_state
*ecs
= &ecss
;
1813 memset (ecs
, 0, sizeof (*ecs
));
1815 old_chain
= make_cleanup_restore_current_thread ();
1817 switch_to_thread (info
->ptid
);
1819 /* Go through handle_inferior_event/normal_stop, so we always
1820 have consistent output as if the stop event had been
1822 ecs
->ptid
= info
->ptid
;
1823 ecs
->event_thread
= find_thread_ptid (info
->ptid
);
1824 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
1825 ecs
->ws
.value
.sig
= TARGET_SIGNAL_0
;
1827 handle_inferior_event (ecs
);
1829 if (!ecs
->wait_some_more
)
1831 struct thread_info
*tp
;
1835 /* Finish off the continuations. The continations
1836 themselves are responsible for realising the thread
1837 didn't finish what it was supposed to do. */
1838 tp
= inferior_thread ();
1839 do_all_intermediate_continuations_thread (tp
);
1840 do_all_continuations_thread (tp
);
1843 do_cleanups (old_chain
);
1849 /* This function is attached as a "thread_stop_requested" observer.
1850 Cleanup local state that assumed the PTID was to be resumed, and
1851 report the stop to the frontend. */
1854 infrun_thread_stop_requested (ptid_t ptid
)
1856 struct displaced_step_request
*it
, *next
, *prev
= NULL
;
1858 /* PTID was requested to stop. Remove it from the displaced
1859 stepping queue, so we don't try to resume it automatically. */
1860 for (it
= displaced_step_request_queue
; it
; it
= next
)
1864 if (ptid_equal (it
->ptid
, ptid
)
1865 || ptid_equal (minus_one_ptid
, ptid
)
1866 || (ptid_is_pid (ptid
)
1867 && ptid_get_pid (ptid
) == ptid_get_pid (it
->ptid
)))
1869 if (displaced_step_request_queue
== it
)
1870 displaced_step_request_queue
= it
->next
;
1872 prev
->next
= it
->next
;
1880 iterate_over_threads (infrun_thread_stop_requested_callback
, &ptid
);
1884 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
1886 if (ptid_equal (target_last_wait_ptid
, tp
->ptid
))
1887 nullify_last_target_wait_ptid ();
1890 /* Callback for iterate_over_threads. */
1893 delete_step_resume_breakpoint_callback (struct thread_info
*info
, void *data
)
1895 if (is_exited (info
->ptid
))
1898 delete_step_resume_breakpoint (info
);
1902 /* In all-stop, delete the step resume breakpoint of any thread that
1903 had one. In non-stop, delete the step resume breakpoint of the
1904 thread that just stopped. */
1907 delete_step_thread_step_resume_breakpoint (void)
1909 if (!target_has_execution
1910 || ptid_equal (inferior_ptid
, null_ptid
))
1911 /* If the inferior has exited, we have already deleted the step
1912 resume breakpoints out of GDB's lists. */
1917 /* If in non-stop mode, only delete the step-resume or
1918 longjmp-resume breakpoint of the thread that just stopped
1920 struct thread_info
*tp
= inferior_thread ();
1921 delete_step_resume_breakpoint (tp
);
1924 /* In all-stop mode, delete all step-resume and longjmp-resume
1925 breakpoints of any thread that had them. */
1926 iterate_over_threads (delete_step_resume_breakpoint_callback
, NULL
);
1929 /* A cleanup wrapper. */
1932 delete_step_thread_step_resume_breakpoint_cleanup (void *arg
)
1934 delete_step_thread_step_resume_breakpoint ();
1937 /* Pretty print the results of target_wait, for debugging purposes. */
1940 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
1941 const struct target_waitstatus
*ws
)
1943 char *status_string
= target_waitstatus_to_string (ws
);
1944 struct ui_file
*tmp_stream
= mem_fileopen ();
1947 /* The text is split over several lines because it was getting too long.
1948 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
1949 output as a unit; we want only one timestamp printed if debug_timestamp
1952 fprintf_unfiltered (tmp_stream
,
1953 "infrun: target_wait (%d", PIDGET (waiton_ptid
));
1954 if (PIDGET (waiton_ptid
) != -1)
1955 fprintf_unfiltered (tmp_stream
,
1956 " [%s]", target_pid_to_str (waiton_ptid
));
1957 fprintf_unfiltered (tmp_stream
, ", status) =\n");
1958 fprintf_unfiltered (tmp_stream
,
1959 "infrun: %d [%s],\n",
1960 PIDGET (result_ptid
), target_pid_to_str (result_ptid
));
1961 fprintf_unfiltered (tmp_stream
,
1965 text
= ui_file_xstrdup (tmp_stream
, NULL
);
1967 /* This uses %s in part to handle %'s in the text, but also to avoid
1968 a gcc error: the format attribute requires a string literal. */
1969 fprintf_unfiltered (gdb_stdlog
, "%s", text
);
1971 xfree (status_string
);
1973 ui_file_delete (tmp_stream
);
1976 /* Wait for control to return from inferior to debugger.
1978 If TREAT_EXEC_AS_SIGTRAP is non-zero, then handle EXEC signals
1979 as if they were SIGTRAP signals. This can be useful during
1980 the startup sequence on some targets such as HP/UX, where
1981 we receive an EXEC event instead of the expected SIGTRAP.
1983 If inferior gets a signal, we may decide to start it up again
1984 instead of returning. That is why there is a loop in this function.
1985 When this function actually returns it means the inferior
1986 should be left stopped and GDB should read more commands. */
1989 wait_for_inferior (int treat_exec_as_sigtrap
)
1991 struct cleanup
*old_cleanups
;
1992 struct execution_control_state ecss
;
1993 struct execution_control_state
*ecs
;
1997 (gdb_stdlog
, "infrun: wait_for_inferior (treat_exec_as_sigtrap=%d)\n",
1998 treat_exec_as_sigtrap
);
2001 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup
, NULL
);
2004 memset (ecs
, 0, sizeof (*ecs
));
2006 /* We'll update this if & when we switch to a new thread. */
2007 previous_inferior_ptid
= inferior_ptid
;
2011 struct cleanup
*old_chain
;
2013 /* We have to invalidate the registers BEFORE calling target_wait
2014 because they can be loaded from the target while in target_wait.
2015 This makes remote debugging a bit more efficient for those
2016 targets that provide critical registers as part of their normal
2017 status mechanism. */
2019 overlay_cache_invalid
= 1;
2020 registers_changed ();
2022 if (deprecated_target_wait_hook
)
2023 ecs
->ptid
= deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, 0);
2025 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, 0);
2028 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
2030 if (treat_exec_as_sigtrap
&& ecs
->ws
.kind
== TARGET_WAITKIND_EXECD
)
2032 xfree (ecs
->ws
.value
.execd_pathname
);
2033 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
2034 ecs
->ws
.value
.sig
= TARGET_SIGNAL_TRAP
;
2037 /* If an error happens while handling the event, propagate GDB's
2038 knowledge of the executing state to the frontend/user running
2040 old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
2042 /* Now figure out what to do with the result of the result. */
2043 handle_inferior_event (ecs
);
2045 /* No error, don't finish the state yet. */
2046 discard_cleanups (old_chain
);
2048 if (!ecs
->wait_some_more
)
2052 do_cleanups (old_cleanups
);
2055 /* Asynchronous version of wait_for_inferior. It is called by the
2056 event loop whenever a change of state is detected on the file
2057 descriptor corresponding to the target. It can be called more than
2058 once to complete a single execution command. In such cases we need
2059 to keep the state in a global variable ECSS. If it is the last time
2060 that this function is called for a single execution command, then
2061 report to the user that the inferior has stopped, and do the
2062 necessary cleanups. */
2065 fetch_inferior_event (void *client_data
)
2067 struct execution_control_state ecss
;
2068 struct execution_control_state
*ecs
= &ecss
;
2069 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
2070 struct cleanup
*ts_old_chain
;
2071 int was_sync
= sync_execution
;
2073 memset (ecs
, 0, sizeof (*ecs
));
2075 /* We'll update this if & when we switch to a new thread. */
2076 previous_inferior_ptid
= inferior_ptid
;
2079 /* In non-stop mode, the user/frontend should not notice a thread
2080 switch due to internal events. Make sure we reverse to the
2081 user selected thread and frame after handling the event and
2082 running any breakpoint commands. */
2083 make_cleanup_restore_current_thread ();
2085 /* We have to invalidate the registers BEFORE calling target_wait
2086 because they can be loaded from the target while in target_wait.
2087 This makes remote debugging a bit more efficient for those
2088 targets that provide critical registers as part of their normal
2089 status mechanism. */
2091 overlay_cache_invalid
= 1;
2092 registers_changed ();
2094 if (deprecated_target_wait_hook
)
2096 deprecated_target_wait_hook (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
2098 ecs
->ptid
= target_wait (waiton_ptid
, &ecs
->ws
, TARGET_WNOHANG
);
2101 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
2104 && ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
2105 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2106 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
2107 /* In non-stop mode, each thread is handled individually. Switch
2108 early, so the global state is set correctly for this
2110 context_switch (ecs
->ptid
);
2112 /* If an error happens while handling the event, propagate GDB's
2113 knowledge of the executing state to the frontend/user running
2116 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
2118 ts_old_chain
= make_cleanup (finish_thread_state_cleanup
, &ecs
->ptid
);
2120 /* Now figure out what to do with the result of the result. */
2121 handle_inferior_event (ecs
);
2123 if (!ecs
->wait_some_more
)
2125 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
2127 delete_step_thread_step_resume_breakpoint ();
2129 /* We may not find an inferior if this was a process exit. */
2130 if (inf
== NULL
|| inf
->stop_soon
== NO_STOP_QUIETLY
)
2133 if (target_has_execution
2134 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2135 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
2136 && ecs
->event_thread
->step_multi
2137 && ecs
->event_thread
->stop_step
)
2138 inferior_event_handler (INF_EXEC_CONTINUE
, NULL
);
2140 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2143 /* No error, don't finish the thread states yet. */
2144 discard_cleanups (ts_old_chain
);
2146 /* Revert thread and frame. */
2147 do_cleanups (old_chain
);
2149 /* If the inferior was in sync execution mode, and now isn't,
2150 restore the prompt. */
2151 if (was_sync
&& !sync_execution
)
2152 display_gdb_prompt (0);
2155 /* Record the frame and location we're currently stepping through. */
2157 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
2159 struct thread_info
*tp
= inferior_thread ();
2161 tp
->step_frame_id
= get_frame_id (frame
);
2162 tp
->step_stack_frame_id
= get_stack_frame_id (frame
);
2164 tp
->current_symtab
= sal
.symtab
;
2165 tp
->current_line
= sal
.line
;
2168 /* Prepare an execution control state for looping through a
2169 wait_for_inferior-type loop. */
2172 init_execution_control_state (struct execution_control_state
*ecs
)
2174 ecs
->random_signal
= 0;
2177 /* Clear context switchable stepping state. */
2180 init_thread_stepping_state (struct thread_info
*tss
)
2182 tss
->stepping_over_breakpoint
= 0;
2183 tss
->step_after_step_resume_breakpoint
= 0;
2184 tss
->stepping_through_solib_after_catch
= 0;
2185 tss
->stepping_through_solib_catchpoints
= NULL
;
2188 /* Return the cached copy of the last pid/waitstatus returned by
2189 target_wait()/deprecated_target_wait_hook(). The data is actually
2190 cached by handle_inferior_event(), which gets called immediately
2191 after target_wait()/deprecated_target_wait_hook(). */
2194 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
2196 *ptidp
= target_last_wait_ptid
;
2197 *status
= target_last_waitstatus
;
2201 nullify_last_target_wait_ptid (void)
2203 target_last_wait_ptid
= minus_one_ptid
;
2206 /* Switch thread contexts. */
2209 context_switch (ptid_t ptid
)
2213 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
2214 target_pid_to_str (inferior_ptid
));
2215 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
2216 target_pid_to_str (ptid
));
2219 switch_to_thread (ptid
);
2223 adjust_pc_after_break (struct execution_control_state
*ecs
)
2225 struct regcache
*regcache
;
2226 struct gdbarch
*gdbarch
;
2227 CORE_ADDR breakpoint_pc
;
2229 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2230 we aren't, just return.
2232 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2233 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2234 implemented by software breakpoints should be handled through the normal
2237 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2238 different signals (SIGILL or SIGEMT for instance), but it is less
2239 clear where the PC is pointing afterwards. It may not match
2240 gdbarch_decr_pc_after_break. I don't know any specific target that
2241 generates these signals at breakpoints (the code has been in GDB since at
2242 least 1992) so I can not guess how to handle them here.
2244 In earlier versions of GDB, a target with
2245 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2246 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2247 target with both of these set in GDB history, and it seems unlikely to be
2248 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2250 if (ecs
->ws
.kind
!= TARGET_WAITKIND_STOPPED
)
2253 if (ecs
->ws
.value
.sig
!= TARGET_SIGNAL_TRAP
)
2256 /* In reverse execution, when a breakpoint is hit, the instruction
2257 under it has already been de-executed. The reported PC always
2258 points at the breakpoint address, so adjusting it further would
2259 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2262 B1 0x08000000 : INSN1
2263 B2 0x08000001 : INSN2
2265 PC -> 0x08000003 : INSN4
2267 Say you're stopped at 0x08000003 as above. Reverse continuing
2268 from that point should hit B2 as below. Reading the PC when the
2269 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2270 been de-executed already.
2272 B1 0x08000000 : INSN1
2273 B2 PC -> 0x08000001 : INSN2
2277 We can't apply the same logic as for forward execution, because
2278 we would wrongly adjust the PC to 0x08000000, since there's a
2279 breakpoint at PC - 1. We'd then report a hit on B1, although
2280 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2282 if (execution_direction
== EXEC_REVERSE
)
2285 /* If this target does not decrement the PC after breakpoints, then
2286 we have nothing to do. */
2287 regcache
= get_thread_regcache (ecs
->ptid
);
2288 gdbarch
= get_regcache_arch (regcache
);
2289 if (gdbarch_decr_pc_after_break (gdbarch
) == 0)
2292 /* Find the location where (if we've hit a breakpoint) the
2293 breakpoint would be. */
2294 breakpoint_pc
= regcache_read_pc (regcache
)
2295 - gdbarch_decr_pc_after_break (gdbarch
);
2297 /* Check whether there actually is a software breakpoint inserted at
2300 If in non-stop mode, a race condition is possible where we've
2301 removed a breakpoint, but stop events for that breakpoint were
2302 already queued and arrive later. To suppress those spurious
2303 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
2304 and retire them after a number of stop events are reported. */
2305 if (software_breakpoint_inserted_here_p (breakpoint_pc
)
2306 || (non_stop
&& moribund_breakpoint_here_p (breakpoint_pc
)))
2308 struct cleanup
*old_cleanups
= NULL
;
2310 old_cleanups
= record_gdb_operation_disable_set ();
2312 /* When using hardware single-step, a SIGTRAP is reported for both
2313 a completed single-step and a software breakpoint. Need to
2314 differentiate between the two, as the latter needs adjusting
2315 but the former does not.
2317 The SIGTRAP can be due to a completed hardware single-step only if
2318 - we didn't insert software single-step breakpoints
2319 - the thread to be examined is still the current thread
2320 - this thread is currently being stepped
2322 If any of these events did not occur, we must have stopped due
2323 to hitting a software breakpoint, and have to back up to the
2326 As a special case, we could have hardware single-stepped a
2327 software breakpoint. In this case (prev_pc == breakpoint_pc),
2328 we also need to back up to the breakpoint address. */
2330 if (singlestep_breakpoints_inserted_p
2331 || !ptid_equal (ecs
->ptid
, inferior_ptid
)
2332 || !currently_stepping (ecs
->event_thread
)
2333 || ecs
->event_thread
->prev_pc
== breakpoint_pc
)
2334 regcache_write_pc (regcache
, breakpoint_pc
);
2337 do_cleanups (old_cleanups
);
2342 init_infwait_state (void)
2344 waiton_ptid
= pid_to_ptid (-1);
2345 infwait_state
= infwait_normal_state
;
2349 error_is_running (void)
2352 Cannot execute this command while the selected thread is running."));
2356 ensure_not_running (void)
2358 if (is_running (inferior_ptid
))
2359 error_is_running ();
2363 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
2365 for (frame
= get_prev_frame (frame
);
2367 frame
= get_prev_frame (frame
))
2369 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
2371 if (get_frame_type (frame
) != INLINE_FRAME
)
2378 /* Given an execution control state that has been freshly filled in
2379 by an event from the inferior, figure out what it means and take
2380 appropriate action. */
2383 handle_inferior_event (struct execution_control_state
*ecs
)
2385 struct frame_info
*frame
;
2386 struct gdbarch
*gdbarch
;
2387 int sw_single_step_trap_p
= 0;
2388 int stopped_by_watchpoint
;
2389 int stepped_after_stopped_by_watchpoint
= 0;
2390 struct symtab_and_line stop_pc_sal
;
2391 enum stop_kind stop_soon
;
2393 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2394 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
2395 && ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
)
2397 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (ecs
->ptid
));
2399 stop_soon
= inf
->stop_soon
;
2402 stop_soon
= NO_STOP_QUIETLY
;
2404 /* Cache the last pid/waitstatus. */
2405 target_last_wait_ptid
= ecs
->ptid
;
2406 target_last_waitstatus
= ecs
->ws
;
2408 /* Always clear state belonging to the previous time we stopped. */
2409 stop_stack_dummy
= 0;
2411 /* If it's a new process, add it to the thread database */
2413 ecs
->new_thread_event
= (!ptid_equal (ecs
->ptid
, inferior_ptid
)
2414 && !ptid_equal (ecs
->ptid
, minus_one_ptid
)
2415 && !in_thread_list (ecs
->ptid
));
2417 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
2418 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
&& ecs
->new_thread_event
)
2419 add_thread (ecs
->ptid
);
2421 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
2423 /* Dependent on valid ECS->EVENT_THREAD. */
2424 adjust_pc_after_break (ecs
);
2426 /* Dependent on the current PC value modified by adjust_pc_after_break. */
2427 reinit_frame_cache ();
2429 if (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
)
2431 breakpoint_retire_moribund ();
2433 /* Mark the non-executing threads accordingly. In all-stop, all
2434 threads of all processes are stopped when we get any event
2435 reported. In non-stop mode, only the event thread stops. If
2436 we're handling a process exit in non-stop mode, there's
2437 nothing to do, as threads of the dead process are gone, and
2438 threads of any other process were left running. */
2440 set_executing (minus_one_ptid
, 0);
2441 else if (ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
2442 && ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
)
2443 set_executing (inferior_ptid
, 0);
2446 switch (infwait_state
)
2448 case infwait_thread_hop_state
:
2450 fprintf_unfiltered (gdb_stdlog
, "infrun: infwait_thread_hop_state\n");
2453 case infwait_normal_state
:
2455 fprintf_unfiltered (gdb_stdlog
, "infrun: infwait_normal_state\n");
2458 case infwait_step_watch_state
:
2460 fprintf_unfiltered (gdb_stdlog
,
2461 "infrun: infwait_step_watch_state\n");
2463 stepped_after_stopped_by_watchpoint
= 1;
2466 case infwait_nonstep_watch_state
:
2468 fprintf_unfiltered (gdb_stdlog
,
2469 "infrun: infwait_nonstep_watch_state\n");
2470 insert_breakpoints ();
2472 /* FIXME-maybe: is this cleaner than setting a flag? Does it
2473 handle things like signals arriving and other things happening
2474 in combination correctly? */
2475 stepped_after_stopped_by_watchpoint
= 1;
2479 internal_error (__FILE__
, __LINE__
, _("bad switch"));
2482 infwait_state
= infwait_normal_state
;
2483 waiton_ptid
= pid_to_ptid (-1);
2485 switch (ecs
->ws
.kind
)
2487 case TARGET_WAITKIND_LOADED
:
2489 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
2490 /* Ignore gracefully during startup of the inferior, as it might
2491 be the shell which has just loaded some objects, otherwise
2492 add the symbols for the newly loaded objects. Also ignore at
2493 the beginning of an attach or remote session; we will query
2494 the full list of libraries once the connection is
2496 if (stop_soon
== NO_STOP_QUIETLY
)
2498 /* Check for any newly added shared libraries if we're
2499 supposed to be adding them automatically. Switch
2500 terminal for any messages produced by
2501 breakpoint_re_set. */
2502 target_terminal_ours_for_output ();
2503 /* NOTE: cagney/2003-11-25: Make certain that the target
2504 stack's section table is kept up-to-date. Architectures,
2505 (e.g., PPC64), use the section table to perform
2506 operations such as address => section name and hence
2507 require the table to contain all sections (including
2508 those found in shared libraries). */
2510 SOLIB_ADD (NULL
, 0, ¤t_target
, auto_solib_add
);
2512 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
2514 target_terminal_inferior ();
2516 /* If requested, stop when the dynamic linker notifies
2517 gdb of events. This allows the user to get control
2518 and place breakpoints in initializer routines for
2519 dynamically loaded objects (among other things). */
2520 if (stop_on_solib_events
)
2522 stop_stepping (ecs
);
2526 /* NOTE drow/2007-05-11: This might be a good place to check
2527 for "catch load". */
2530 /* If we are skipping through a shell, or through shared library
2531 loading that we aren't interested in, resume the program. If
2532 we're running the program normally, also resume. But stop if
2533 we're attaching or setting up a remote connection. */
2534 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
2536 /* Loading of shared libraries might have changed breakpoint
2537 addresses. Make sure new breakpoints are inserted. */
2538 if (stop_soon
== NO_STOP_QUIETLY
2539 && !breakpoints_always_inserted_mode ())
2540 insert_breakpoints ();
2541 resume (0, TARGET_SIGNAL_0
);
2542 prepare_to_wait (ecs
);
2548 case TARGET_WAITKIND_SPURIOUS
:
2550 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
2551 resume (0, TARGET_SIGNAL_0
);
2552 prepare_to_wait (ecs
);
2555 case TARGET_WAITKIND_EXITED
:
2557 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXITED\n");
2558 inferior_ptid
= ecs
->ptid
;
2559 target_terminal_ours (); /* Must do this before mourn anyway */
2560 print_stop_reason (EXITED
, ecs
->ws
.value
.integer
);
2562 /* Record the exit code in the convenience variable $_exitcode, so
2563 that the user can inspect this again later. */
2564 set_internalvar_integer (lookup_internalvar ("_exitcode"),
2565 (LONGEST
) ecs
->ws
.value
.integer
);
2566 gdb_flush (gdb_stdout
);
2567 target_mourn_inferior ();
2568 singlestep_breakpoints_inserted_p
= 0;
2569 stop_print_frame
= 0;
2570 stop_stepping (ecs
);
2573 case TARGET_WAITKIND_SIGNALLED
:
2575 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SIGNALLED\n");
2576 inferior_ptid
= ecs
->ptid
;
2577 stop_print_frame
= 0;
2578 target_terminal_ours (); /* Must do this before mourn anyway */
2580 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't
2581 reach here unless the inferior is dead. However, for years
2582 target_kill() was called here, which hints that fatal signals aren't
2583 really fatal on some systems. If that's true, then some changes
2585 target_mourn_inferior ();
2587 print_stop_reason (SIGNAL_EXITED
, ecs
->ws
.value
.sig
);
2588 singlestep_breakpoints_inserted_p
= 0;
2589 stop_stepping (ecs
);
2592 /* The following are the only cases in which we keep going;
2593 the above cases end in a continue or goto. */
2594 case TARGET_WAITKIND_FORKED
:
2595 case TARGET_WAITKIND_VFORKED
:
2597 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
2599 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
2601 context_switch (ecs
->ptid
);
2602 reinit_frame_cache ();
2605 /* Immediately detach breakpoints from the child before there's
2606 any chance of letting the user delete breakpoints from the
2607 breakpoint lists. If we don't do this early, it's easy to
2608 leave left over traps in the child, vis: "break foo; catch
2609 fork; c; <fork>; del; c; <child calls foo>". We only follow
2610 the fork on the last `continue', and by that time the
2611 breakpoint at "foo" is long gone from the breakpoint table.
2612 If we vforked, then we don't need to unpatch here, since both
2613 parent and child are sharing the same memory pages; we'll
2614 need to unpatch at follow/detach time instead to be certain
2615 that new breakpoints added between catchpoint hit time and
2616 vfork follow are detached. */
2617 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
2619 int child_pid
= ptid_get_pid (ecs
->ws
.value
.related_pid
);
2621 /* This won't actually modify the breakpoint list, but will
2622 physically remove the breakpoints from the child. */
2623 detach_breakpoints (child_pid
);
2626 /* In case the event is caught by a catchpoint, remember that
2627 the event is to be followed at the next resume of the thread,
2628 and not immediately. */
2629 ecs
->event_thread
->pending_follow
= ecs
->ws
;
2631 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
2633 ecs
->event_thread
->stop_bpstat
= bpstat_stop_status (stop_pc
, ecs
->ptid
);
2635 ecs
->random_signal
= !bpstat_explains_signal (ecs
->event_thread
->stop_bpstat
);
2637 /* If no catchpoint triggered for this, then keep going. */
2638 if (ecs
->random_signal
)
2642 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
2644 should_resume
= follow_fork ();
2646 ecs
->event_thread
= inferior_thread ();
2647 ecs
->ptid
= inferior_ptid
;
2652 stop_stepping (ecs
);
2655 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_TRAP
;
2656 goto process_event_stop_test
;
2658 case TARGET_WAITKIND_EXECD
:
2660 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
2662 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
2664 context_switch (ecs
->ptid
);
2665 reinit_frame_cache ();
2668 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
2670 /* This causes the eventpoints and symbol table to be reset.
2671 Must do this now, before trying to determine whether to
2673 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
2675 ecs
->event_thread
->stop_bpstat
= bpstat_stop_status (stop_pc
, ecs
->ptid
);
2676 ecs
->random_signal
= !bpstat_explains_signal (ecs
->event_thread
->stop_bpstat
);
2678 /* Note that this may be referenced from inside
2679 bpstat_stop_status above, through inferior_has_execd. */
2680 xfree (ecs
->ws
.value
.execd_pathname
);
2681 ecs
->ws
.value
.execd_pathname
= NULL
;
2683 /* If no catchpoint triggered for this, then keep going. */
2684 if (ecs
->random_signal
)
2686 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
2690 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_TRAP
;
2691 goto process_event_stop_test
;
2693 /* Be careful not to try to gather much state about a thread
2694 that's in a syscall. It's frequently a losing proposition. */
2695 case TARGET_WAITKIND_SYSCALL_ENTRY
:
2697 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
2698 resume (0, TARGET_SIGNAL_0
);
2699 prepare_to_wait (ecs
);
2702 /* Before examining the threads further, step this thread to
2703 get it entirely out of the syscall. (We get notice of the
2704 event when the thread is just on the verge of exiting a
2705 syscall. Stepping one instruction seems to get it back
2707 case TARGET_WAITKIND_SYSCALL_RETURN
:
2709 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
2710 target_resume (ecs
->ptid
, 1, TARGET_SIGNAL_0
);
2711 prepare_to_wait (ecs
);
2714 case TARGET_WAITKIND_STOPPED
:
2716 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
2717 ecs
->event_thread
->stop_signal
= ecs
->ws
.value
.sig
;
2720 case TARGET_WAITKIND_NO_HISTORY
:
2721 /* Reverse execution: target ran out of history info. */
2722 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
2723 print_stop_reason (NO_HISTORY
, 0);
2724 stop_stepping (ecs
);
2727 /* We had an event in the inferior, but we are not interested
2728 in handling it at this level. The lower layers have already
2729 done what needs to be done, if anything.
2731 One of the possible circumstances for this is when the
2732 inferior produces output for the console. The inferior has
2733 not stopped, and we are ignoring the event. Another possible
2734 circumstance is any event which the lower level knows will be
2735 reported multiple times without an intervening resume. */
2736 case TARGET_WAITKIND_IGNORE
:
2738 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
2739 prepare_to_wait (ecs
);
2743 if (ecs
->new_thread_event
)
2746 /* Non-stop assumes that the target handles adding new threads
2747 to the thread list. */
2748 internal_error (__FILE__
, __LINE__
, "\
2749 targets should add new threads to the thread list themselves in non-stop mode.");
2751 /* We may want to consider not doing a resume here in order to
2752 give the user a chance to play with the new thread. It might
2753 be good to make that a user-settable option. */
2755 /* At this point, all threads are stopped (happens automatically
2756 in either the OS or the native code). Therefore we need to
2757 continue all threads in order to make progress. */
2759 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
2760 context_switch (ecs
->ptid
);
2761 target_resume (RESUME_ALL
, 0, TARGET_SIGNAL_0
);
2762 prepare_to_wait (ecs
);
2766 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
)
2768 /* Do we need to clean up the state of a thread that has
2769 completed a displaced single-step? (Doing so usually affects
2770 the PC, so do it here, before we set stop_pc.) */
2771 displaced_step_fixup (ecs
->ptid
, ecs
->event_thread
->stop_signal
);
2773 /* If we either finished a single-step or hit a breakpoint, but
2774 the user wanted this thread to be stopped, pretend we got a
2775 SIG0 (generic unsignaled stop). */
2777 if (ecs
->event_thread
->stop_requested
2778 && ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
2779 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
2782 stop_pc
= regcache_read_pc (get_thread_regcache (ecs
->ptid
));
2786 struct regcache
*regcache
= get_thread_regcache (ecs
->ptid
);
2787 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2789 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
2790 paddress (gdbarch
, stop_pc
));
2791 if (target_stopped_by_watchpoint ())
2794 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
2796 if (target_stopped_data_address (¤t_target
, &addr
))
2797 fprintf_unfiltered (gdb_stdlog
,
2798 "infrun: stopped data address = %s\n",
2799 paddress (gdbarch
, addr
));
2801 fprintf_unfiltered (gdb_stdlog
,
2802 "infrun: (no data address available)\n");
2806 if (stepping_past_singlestep_breakpoint
)
2808 gdb_assert (singlestep_breakpoints_inserted_p
);
2809 gdb_assert (ptid_equal (singlestep_ptid
, ecs
->ptid
));
2810 gdb_assert (!ptid_equal (singlestep_ptid
, saved_singlestep_ptid
));
2812 stepping_past_singlestep_breakpoint
= 0;
2814 /* We've either finished single-stepping past the single-step
2815 breakpoint, or stopped for some other reason. It would be nice if
2816 we could tell, but we can't reliably. */
2817 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
2820 fprintf_unfiltered (gdb_stdlog
, "infrun: stepping_past_singlestep_breakpoint\n");
2821 /* Pull the single step breakpoints out of the target. */
2822 remove_single_step_breakpoints ();
2823 singlestep_breakpoints_inserted_p
= 0;
2825 ecs
->random_signal
= 0;
2826 ecs
->event_thread
->trap_expected
= 0;
2828 context_switch (saved_singlestep_ptid
);
2829 if (deprecated_context_hook
)
2830 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
2832 resume (1, TARGET_SIGNAL_0
);
2833 prepare_to_wait (ecs
);
2838 if (!ptid_equal (deferred_step_ptid
, null_ptid
))
2840 /* In non-stop mode, there's never a deferred_step_ptid set. */
2841 gdb_assert (!non_stop
);
2843 /* If we stopped for some other reason than single-stepping, ignore
2844 the fact that we were supposed to switch back. */
2845 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
2848 fprintf_unfiltered (gdb_stdlog
,
2849 "infrun: handling deferred step\n");
2851 /* Pull the single step breakpoints out of the target. */
2852 if (singlestep_breakpoints_inserted_p
)
2854 remove_single_step_breakpoints ();
2855 singlestep_breakpoints_inserted_p
= 0;
2858 /* Note: We do not call context_switch at this point, as the
2859 context is already set up for stepping the original thread. */
2860 switch_to_thread (deferred_step_ptid
);
2861 deferred_step_ptid
= null_ptid
;
2862 /* Suppress spurious "Switching to ..." message. */
2863 previous_inferior_ptid
= inferior_ptid
;
2865 resume (1, TARGET_SIGNAL_0
);
2866 prepare_to_wait (ecs
);
2870 deferred_step_ptid
= null_ptid
;
2873 /* See if a thread hit a thread-specific breakpoint that was meant for
2874 another thread. If so, then step that thread past the breakpoint,
2877 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
2879 int thread_hop_needed
= 0;
2881 /* Check if a regular breakpoint has been hit before checking
2882 for a potential single step breakpoint. Otherwise, GDB will
2883 not see this breakpoint hit when stepping onto breakpoints. */
2884 if (regular_breakpoint_inserted_here_p (stop_pc
))
2886 ecs
->random_signal
= 0;
2887 if (!breakpoint_thread_match (stop_pc
, ecs
->ptid
))
2888 thread_hop_needed
= 1;
2890 else if (singlestep_breakpoints_inserted_p
)
2892 /* We have not context switched yet, so this should be true
2893 no matter which thread hit the singlestep breakpoint. */
2894 gdb_assert (ptid_equal (inferior_ptid
, singlestep_ptid
));
2896 fprintf_unfiltered (gdb_stdlog
, "infrun: software single step "
2898 target_pid_to_str (ecs
->ptid
));
2900 ecs
->random_signal
= 0;
2901 /* The call to in_thread_list is necessary because PTIDs sometimes
2902 change when we go from single-threaded to multi-threaded. If
2903 the singlestep_ptid is still in the list, assume that it is
2904 really different from ecs->ptid. */
2905 if (!ptid_equal (singlestep_ptid
, ecs
->ptid
)
2906 && in_thread_list (singlestep_ptid
))
2908 /* If the PC of the thread we were trying to single-step
2909 has changed, discard this event (which we were going
2910 to ignore anyway), and pretend we saw that thread
2911 trap. This prevents us continuously moving the
2912 single-step breakpoint forward, one instruction at a
2913 time. If the PC has changed, then the thread we were
2914 trying to single-step has trapped or been signalled,
2915 but the event has not been reported to GDB yet.
2917 There might be some cases where this loses signal
2918 information, if a signal has arrived at exactly the
2919 same time that the PC changed, but this is the best
2920 we can do with the information available. Perhaps we
2921 should arrange to report all events for all threads
2922 when they stop, or to re-poll the remote looking for
2923 this particular thread (i.e. temporarily enable
2926 CORE_ADDR new_singlestep_pc
2927 = regcache_read_pc (get_thread_regcache (singlestep_ptid
));
2929 if (new_singlestep_pc
!= singlestep_pc
)
2931 enum target_signal stop_signal
;
2934 fprintf_unfiltered (gdb_stdlog
, "infrun: unexpected thread,"
2935 " but expected thread advanced also\n");
2937 /* The current context still belongs to
2938 singlestep_ptid. Don't swap here, since that's
2939 the context we want to use. Just fudge our
2940 state and continue. */
2941 stop_signal
= ecs
->event_thread
->stop_signal
;
2942 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
2943 ecs
->ptid
= singlestep_ptid
;
2944 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
2945 ecs
->event_thread
->stop_signal
= stop_signal
;
2946 stop_pc
= new_singlestep_pc
;
2951 fprintf_unfiltered (gdb_stdlog
,
2952 "infrun: unexpected thread\n");
2954 thread_hop_needed
= 1;
2955 stepping_past_singlestep_breakpoint
= 1;
2956 saved_singlestep_ptid
= singlestep_ptid
;
2961 if (thread_hop_needed
)
2963 struct regcache
*thread_regcache
;
2964 int remove_status
= 0;
2967 fprintf_unfiltered (gdb_stdlog
, "infrun: thread_hop_needed\n");
2969 /* Switch context before touching inferior memory, the
2970 previous thread may have exited. */
2971 if (!ptid_equal (inferior_ptid
, ecs
->ptid
))
2972 context_switch (ecs
->ptid
);
2974 /* Saw a breakpoint, but it was hit by the wrong thread.
2977 if (singlestep_breakpoints_inserted_p
)
2979 /* Pull the single step breakpoints out of the target. */
2980 remove_single_step_breakpoints ();
2981 singlestep_breakpoints_inserted_p
= 0;
2984 /* If the arch can displace step, don't remove the
2986 thread_regcache
= get_thread_regcache (ecs
->ptid
);
2987 if (!use_displaced_stepping (get_regcache_arch (thread_regcache
)))
2988 remove_status
= remove_breakpoints ();
2990 /* Did we fail to remove breakpoints? If so, try
2991 to set the PC past the bp. (There's at least
2992 one situation in which we can fail to remove
2993 the bp's: On HP-UX's that use ttrace, we can't
2994 change the address space of a vforking child
2995 process until the child exits (well, okay, not
2996 then either :-) or execs. */
2997 if (remove_status
!= 0)
2998 error (_("Cannot step over breakpoint hit in wrong thread"));
3003 /* Only need to require the next event from this
3004 thread in all-stop mode. */
3005 waiton_ptid
= ecs
->ptid
;
3006 infwait_state
= infwait_thread_hop_state
;
3009 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3014 else if (singlestep_breakpoints_inserted_p
)
3016 sw_single_step_trap_p
= 1;
3017 ecs
->random_signal
= 0;
3021 ecs
->random_signal
= 1;
3023 /* See if something interesting happened to the non-current thread. If
3024 so, then switch to that thread. */
3025 if (!ptid_equal (ecs
->ptid
, inferior_ptid
))
3028 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
3030 context_switch (ecs
->ptid
);
3032 if (deprecated_context_hook
)
3033 deprecated_context_hook (pid_to_thread_id (ecs
->ptid
));
3036 /* At this point, get hold of the now-current thread's frame. */
3037 frame
= get_current_frame ();
3038 gdbarch
= get_frame_arch (frame
);
3040 if (singlestep_breakpoints_inserted_p
)
3042 /* Pull the single step breakpoints out of the target. */
3043 remove_single_step_breakpoints ();
3044 singlestep_breakpoints_inserted_p
= 0;
3047 if (stepped_after_stopped_by_watchpoint
)
3048 stopped_by_watchpoint
= 0;
3050 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
3052 /* If necessary, step over this watchpoint. We'll be back to display
3054 if (stopped_by_watchpoint
3055 && (target_have_steppable_watchpoint
3056 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
3058 /* At this point, we are stopped at an instruction which has
3059 attempted to write to a piece of memory under control of
3060 a watchpoint. The instruction hasn't actually executed
3061 yet. If we were to evaluate the watchpoint expression
3062 now, we would get the old value, and therefore no change
3063 would seem to have occurred.
3065 In order to make watchpoints work `right', we really need
3066 to complete the memory write, and then evaluate the
3067 watchpoint expression. We do this by single-stepping the
3070 It may not be necessary to disable the watchpoint to stop over
3071 it. For example, the PA can (with some kernel cooperation)
3072 single step over a watchpoint without disabling the watchpoint.
3074 It is far more common to need to disable a watchpoint to step
3075 the inferior over it. If we have non-steppable watchpoints,
3076 we must disable the current watchpoint; it's simplest to
3077 disable all watchpoints and breakpoints. */
3080 if (!target_have_steppable_watchpoint
)
3081 remove_breakpoints ();
3083 hw_step
= maybe_software_singlestep (gdbarch
, stop_pc
);
3084 target_resume (ecs
->ptid
, hw_step
, TARGET_SIGNAL_0
);
3085 waiton_ptid
= ecs
->ptid
;
3086 if (target_have_steppable_watchpoint
)
3087 infwait_state
= infwait_step_watch_state
;
3089 infwait_state
= infwait_nonstep_watch_state
;
3090 prepare_to_wait (ecs
);
3094 ecs
->stop_func_start
= 0;
3095 ecs
->stop_func_end
= 0;
3096 ecs
->stop_func_name
= 0;
3097 /* Don't care about return value; stop_func_start and stop_func_name
3098 will both be 0 if it doesn't work. */
3099 find_pc_partial_function (stop_pc
, &ecs
->stop_func_name
,
3100 &ecs
->stop_func_start
, &ecs
->stop_func_end
);
3101 ecs
->stop_func_start
3102 += gdbarch_deprecated_function_start_offset (gdbarch
);
3103 ecs
->event_thread
->stepping_over_breakpoint
= 0;
3104 bpstat_clear (&ecs
->event_thread
->stop_bpstat
);
3105 ecs
->event_thread
->stop_step
= 0;
3106 stop_print_frame
= 1;
3107 ecs
->random_signal
= 0;
3108 stopped_by_random_signal
= 0;
3110 /* Hide inlined functions starting here, unless we just performed stepi or
3111 nexti. After stepi and nexti, always show the innermost frame (not any
3112 inline function call sites). */
3113 if (ecs
->event_thread
->step_range_end
!= 1)
3114 skip_inline_frames (ecs
->ptid
);
3116 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
3117 && ecs
->event_thread
->trap_expected
3118 && gdbarch_single_step_through_delay_p (gdbarch
)
3119 && currently_stepping (ecs
->event_thread
))
3121 /* We're trying to step off a breakpoint. Turns out that we're
3122 also on an instruction that needs to be stepped multiple
3123 times before it's been fully executing. E.g., architectures
3124 with a delay slot. It needs to be stepped twice, once for
3125 the instruction and once for the delay slot. */
3126 int step_through_delay
3127 = gdbarch_single_step_through_delay (gdbarch
, frame
);
3128 if (debug_infrun
&& step_through_delay
)
3129 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
3130 if (ecs
->event_thread
->step_range_end
== 0 && step_through_delay
)
3132 /* The user issued a continue when stopped at a breakpoint.
3133 Set up for another trap and get out of here. */
3134 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3138 else if (step_through_delay
)
3140 /* The user issued a step when stopped at a breakpoint.
3141 Maybe we should stop, maybe we should not - the delay
3142 slot *might* correspond to a line of source. In any
3143 case, don't decide that here, just set
3144 ecs->stepping_over_breakpoint, making sure we
3145 single-step again before breakpoints are re-inserted. */
3146 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3150 /* Look at the cause of the stop, and decide what to do.
3151 The alternatives are:
3152 1) stop_stepping and return; to really stop and return to the debugger,
3153 2) keep_going and return to start up again
3154 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
3155 3) set ecs->random_signal to 1, and the decision between 1 and 2
3156 will be made according to the signal handling tables. */
3158 /* First, distinguish signals caused by the debugger from signals
3159 that have to do with the program's own actions. Note that
3160 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3161 on the operating system version. Here we detect when a SIGILL or
3162 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3163 something similar for SIGSEGV, since a SIGSEGV will be generated
3164 when we're trying to execute a breakpoint instruction on a
3165 non-executable stack. This happens for call dummy breakpoints
3166 for architectures like SPARC that place call dummies on the
3169 If we're doing a displaced step past a breakpoint, then the
3170 breakpoint is always inserted at the original instruction;
3171 non-standard signals can't be explained by the breakpoint. */
3172 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
3173 || (! ecs
->event_thread
->trap_expected
3174 && breakpoint_inserted_here_p (stop_pc
)
3175 && (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_ILL
3176 || ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_SEGV
3177 || ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_EMT
))
3178 || stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_NO_SIGSTOP
3179 || stop_soon
== STOP_QUIETLY_REMOTE
)
3181 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
&& stop_after_trap
)
3184 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
3185 stop_print_frame
= 0;
3186 stop_stepping (ecs
);
3190 /* This is originated from start_remote(), start_inferior() and
3191 shared libraries hook functions. */
3192 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
3195 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
3196 stop_stepping (ecs
);
3200 /* This originates from attach_command(). We need to overwrite
3201 the stop_signal here, because some kernels don't ignore a
3202 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
3203 See more comments in inferior.h. On the other hand, if we
3204 get a non-SIGSTOP, report it to the user - assume the backend
3205 will handle the SIGSTOP if it should show up later.
3207 Also consider that the attach is complete when we see a
3208 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
3209 target extended-remote report it instead of a SIGSTOP
3210 (e.g. gdbserver). We already rely on SIGTRAP being our
3211 signal, so this is no exception.
3213 Also consider that the attach is complete when we see a
3214 TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell
3215 the target to stop all threads of the inferior, in case the
3216 low level attach operation doesn't stop them implicitly. If
3217 they weren't stopped implicitly, then the stub will report a
3218 TARGET_SIGNAL_0, meaning: stopped for no particular reason
3219 other than GDB's request. */
3220 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
3221 && (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_STOP
3222 || ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
3223 || ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_0
))
3225 stop_stepping (ecs
);
3226 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
3230 /* See if there is a breakpoint at the current PC. */
3231 ecs
->event_thread
->stop_bpstat
= bpstat_stop_status (stop_pc
, ecs
->ptid
);
3233 /* Following in case break condition called a
3235 stop_print_frame
= 1;
3237 /* NOTE: cagney/2003-03-29: These two checks for a random signal
3238 at one stage in the past included checks for an inferior
3239 function call's call dummy's return breakpoint. The original
3240 comment, that went with the test, read:
3242 ``End of a stack dummy. Some systems (e.g. Sony news) give
3243 another signal besides SIGTRAP, so check here as well as
3246 If someone ever tries to get call dummys on a
3247 non-executable stack to work (where the target would stop
3248 with something like a SIGSEGV), then those tests might need
3249 to be re-instated. Given, however, that the tests were only
3250 enabled when momentary breakpoints were not being used, I
3251 suspect that it won't be the case.
3253 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
3254 be necessary for call dummies on a non-executable stack on
3257 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
)
3259 = !(bpstat_explains_signal (ecs
->event_thread
->stop_bpstat
)
3260 || ecs
->event_thread
->trap_expected
3261 || (ecs
->event_thread
->step_range_end
3262 && ecs
->event_thread
->step_resume_breakpoint
== NULL
));
3265 ecs
->random_signal
= !bpstat_explains_signal (ecs
->event_thread
->stop_bpstat
);
3266 if (!ecs
->random_signal
)
3267 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_TRAP
;
3271 /* When we reach this point, we've pretty much decided
3272 that the reason for stopping must've been a random
3273 (unexpected) signal. */
3276 ecs
->random_signal
= 1;
3278 process_event_stop_test
:
3280 /* Re-fetch current thread's frame in case we did a
3281 "goto process_event_stop_test" above. */
3282 frame
= get_current_frame ();
3283 gdbarch
= get_frame_arch (frame
);
3285 /* For the program's own signals, act according to
3286 the signal handling tables. */
3288 if (ecs
->random_signal
)
3290 /* Signal not for debugging purposes. */
3294 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal %d\n",
3295 ecs
->event_thread
->stop_signal
);
3297 stopped_by_random_signal
= 1;
3299 if (signal_print
[ecs
->event_thread
->stop_signal
])
3302 target_terminal_ours_for_output ();
3303 print_stop_reason (SIGNAL_RECEIVED
, ecs
->event_thread
->stop_signal
);
3305 /* Always stop on signals if we're either just gaining control
3306 of the program, or the user explicitly requested this thread
3307 to remain stopped. */
3308 if (stop_soon
!= NO_STOP_QUIETLY
3309 || ecs
->event_thread
->stop_requested
3310 || signal_stop_state (ecs
->event_thread
->stop_signal
))
3312 stop_stepping (ecs
);
3315 /* If not going to stop, give terminal back
3316 if we took it away. */
3318 target_terminal_inferior ();
3320 /* Clear the signal if it should not be passed. */
3321 if (signal_program
[ecs
->event_thread
->stop_signal
] == 0)
3322 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
3324 if (ecs
->event_thread
->prev_pc
== stop_pc
3325 && ecs
->event_thread
->trap_expected
3326 && ecs
->event_thread
->step_resume_breakpoint
== NULL
)
3328 /* We were just starting a new sequence, attempting to
3329 single-step off of a breakpoint and expecting a SIGTRAP.
3330 Instead this signal arrives. This signal will take us out
3331 of the stepping range so GDB needs to remember to, when
3332 the signal handler returns, resume stepping off that
3334 /* To simplify things, "continue" is forced to use the same
3335 code paths as single-step - set a breakpoint at the
3336 signal return address and then, once hit, step off that
3339 fprintf_unfiltered (gdb_stdlog
,
3340 "infrun: signal arrived while stepping over "
3343 insert_step_resume_breakpoint_at_frame (frame
);
3344 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
3349 if (ecs
->event_thread
->step_range_end
!= 0
3350 && ecs
->event_thread
->stop_signal
!= TARGET_SIGNAL_0
3351 && (ecs
->event_thread
->step_range_start
<= stop_pc
3352 && stop_pc
< ecs
->event_thread
->step_range_end
)
3353 && frame_id_eq (get_stack_frame_id (frame
),
3354 ecs
->event_thread
->step_stack_frame_id
)
3355 && ecs
->event_thread
->step_resume_breakpoint
== NULL
)
3357 /* The inferior is about to take a signal that will take it
3358 out of the single step range. Set a breakpoint at the
3359 current PC (which is presumably where the signal handler
3360 will eventually return) and then allow the inferior to
3363 Note that this is only needed for a signal delivered
3364 while in the single-step range. Nested signals aren't a
3365 problem as they eventually all return. */
3367 fprintf_unfiltered (gdb_stdlog
,
3368 "infrun: signal may take us out of "
3369 "single-step range\n");
3371 insert_step_resume_breakpoint_at_frame (frame
);
3376 /* Note: step_resume_breakpoint may be non-NULL. This occures
3377 when either there's a nested signal, or when there's a
3378 pending signal enabled just as the signal handler returns
3379 (leaving the inferior at the step-resume-breakpoint without
3380 actually executing it). Either way continue until the
3381 breakpoint is really hit. */
3386 /* Handle cases caused by hitting a breakpoint. */
3388 CORE_ADDR jmp_buf_pc
;
3389 struct bpstat_what what
;
3391 what
= bpstat_what (ecs
->event_thread
->stop_bpstat
);
3393 if (what
.call_dummy
)
3395 stop_stack_dummy
= 1;
3398 switch (what
.main_action
)
3400 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
3401 /* If we hit the breakpoint at longjmp while stepping, we
3402 install a momentary breakpoint at the target of the
3406 fprintf_unfiltered (gdb_stdlog
,
3407 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
3409 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3411 if (!gdbarch_get_longjmp_target_p (gdbarch
)
3412 || !gdbarch_get_longjmp_target (gdbarch
, frame
, &jmp_buf_pc
))
3415 fprintf_unfiltered (gdb_stdlog
, "\
3416 infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME (!gdbarch_get_longjmp_target)\n");
3421 /* We're going to replace the current step-resume breakpoint
3422 with a longjmp-resume breakpoint. */
3423 delete_step_resume_breakpoint (ecs
->event_thread
);
3425 /* Insert a breakpoint at resume address. */
3426 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
3431 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
3433 fprintf_unfiltered (gdb_stdlog
,
3434 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
3436 gdb_assert (ecs
->event_thread
->step_resume_breakpoint
!= NULL
);
3437 delete_step_resume_breakpoint (ecs
->event_thread
);
3439 ecs
->event_thread
->stop_step
= 1;
3440 print_stop_reason (END_STEPPING_RANGE
, 0);
3441 stop_stepping (ecs
);
3444 case BPSTAT_WHAT_SINGLE
:
3446 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
3447 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3448 /* Still need to check other stuff, at least the case
3449 where we are stepping and step out of the right range. */
3452 case BPSTAT_WHAT_STOP_NOISY
:
3454 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
3455 stop_print_frame
= 1;
3457 /* We are about to nuke the step_resume_breakpointt via the
3458 cleanup chain, so no need to worry about it here. */
3460 stop_stepping (ecs
);
3463 case BPSTAT_WHAT_STOP_SILENT
:
3465 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
3466 stop_print_frame
= 0;
3468 /* We are about to nuke the step_resume_breakpoin via the
3469 cleanup chain, so no need to worry about it here. */
3471 stop_stepping (ecs
);
3474 case BPSTAT_WHAT_STEP_RESUME
:
3476 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
3478 delete_step_resume_breakpoint (ecs
->event_thread
);
3479 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
3481 /* Back when the step-resume breakpoint was inserted, we
3482 were trying to single-step off a breakpoint. Go back
3484 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
3485 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3489 if (stop_pc
== ecs
->stop_func_start
3490 && execution_direction
== EXEC_REVERSE
)
3492 /* We are stepping over a function call in reverse, and
3493 just hit the step-resume breakpoint at the start
3494 address of the function. Go back to single-stepping,
3495 which should take us back to the function call. */
3496 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3502 case BPSTAT_WHAT_CHECK_SHLIBS
:
3505 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_CHECK_SHLIBS\n");
3507 /* Check for any newly added shared libraries if we're
3508 supposed to be adding them automatically. Switch
3509 terminal for any messages produced by
3510 breakpoint_re_set. */
3511 target_terminal_ours_for_output ();
3512 /* NOTE: cagney/2003-11-25: Make certain that the target
3513 stack's section table is kept up-to-date. Architectures,
3514 (e.g., PPC64), use the section table to perform
3515 operations such as address => section name and hence
3516 require the table to contain all sections (including
3517 those found in shared libraries). */
3519 SOLIB_ADD (NULL
, 0, ¤t_target
, auto_solib_add
);
3521 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
3523 target_terminal_inferior ();
3525 /* If requested, stop when the dynamic linker notifies
3526 gdb of events. This allows the user to get control
3527 and place breakpoints in initializer routines for
3528 dynamically loaded objects (among other things). */
3529 if (stop_on_solib_events
|| stop_stack_dummy
)
3531 stop_stepping (ecs
);
3536 /* We want to step over this breakpoint, then keep going. */
3537 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3543 case BPSTAT_WHAT_LAST
:
3544 /* Not a real code, but listed here to shut up gcc -Wall. */
3546 case BPSTAT_WHAT_KEEP_CHECKING
:
3551 /* We come here if we hit a breakpoint but should not
3552 stop for it. Possibly we also were stepping
3553 and should stop for that. So fall through and
3554 test for stepping. But, if not stepping,
3557 /* In all-stop mode, if we're currently stepping but have stopped in
3558 some other thread, we need to switch back to the stepped thread. */
3561 struct thread_info
*tp
;
3562 tp
= iterate_over_threads (currently_stepping_or_nexting_callback
,
3566 /* However, if the current thread is blocked on some internal
3567 breakpoint, and we simply need to step over that breakpoint
3568 to get it going again, do that first. */
3569 if ((ecs
->event_thread
->trap_expected
3570 && ecs
->event_thread
->stop_signal
!= TARGET_SIGNAL_TRAP
)
3571 || ecs
->event_thread
->stepping_over_breakpoint
)
3577 /* If the stepping thread exited, then don't try to switch
3578 back and resume it, which could fail in several different
3579 ways depending on the target. Instead, just keep going.
3581 We can find a stepping dead thread in the thread list in
3584 - The target supports thread exit events, and when the
3585 target tries to delete the thread from the thread list,
3586 inferior_ptid pointed at the exiting thread. In such
3587 case, calling delete_thread does not really remove the
3588 thread from the list; instead, the thread is left listed,
3589 with 'exited' state.
3591 - The target's debug interface does not support thread
3592 exit events, and so we have no idea whatsoever if the
3593 previously stepping thread is still alive. For that
3594 reason, we need to synchronously query the target
3596 if (is_exited (tp
->ptid
)
3597 || !target_thread_alive (tp
->ptid
))
3600 fprintf_unfiltered (gdb_stdlog
, "\
3601 infrun: not switching back to stepped thread, it has vanished\n");
3603 delete_thread (tp
->ptid
);
3608 /* Otherwise, we no longer expect a trap in the current thread.
3609 Clear the trap_expected flag before switching back -- this is
3610 what keep_going would do as well, if we called it. */
3611 ecs
->event_thread
->trap_expected
= 0;
3614 fprintf_unfiltered (gdb_stdlog
,
3615 "infrun: switching back to stepped thread\n");
3617 ecs
->event_thread
= tp
;
3618 ecs
->ptid
= tp
->ptid
;
3619 context_switch (ecs
->ptid
);
3625 /* Are we stepping to get the inferior out of the dynamic linker's
3626 hook (and possibly the dld itself) after catching a shlib
3628 if (ecs
->event_thread
->stepping_through_solib_after_catch
)
3630 #if defined(SOLIB_ADD)
3631 /* Have we reached our destination? If not, keep going. */
3632 if (SOLIB_IN_DYNAMIC_LINKER (PIDGET (ecs
->ptid
), stop_pc
))
3635 fprintf_unfiltered (gdb_stdlog
, "infrun: stepping in dynamic linker\n");
3636 ecs
->event_thread
->stepping_over_breakpoint
= 1;
3642 fprintf_unfiltered (gdb_stdlog
, "infrun: step past dynamic linker\n");
3643 /* Else, stop and report the catchpoint(s) whose triggering
3644 caused us to begin stepping. */
3645 ecs
->event_thread
->stepping_through_solib_after_catch
= 0;
3646 bpstat_clear (&ecs
->event_thread
->stop_bpstat
);
3647 ecs
->event_thread
->stop_bpstat
3648 = bpstat_copy (ecs
->event_thread
->stepping_through_solib_catchpoints
);
3649 bpstat_clear (&ecs
->event_thread
->stepping_through_solib_catchpoints
);
3650 stop_print_frame
= 1;
3651 stop_stepping (ecs
);
3655 if (ecs
->event_thread
->step_resume_breakpoint
)
3658 fprintf_unfiltered (gdb_stdlog
,
3659 "infrun: step-resume breakpoint is inserted\n");
3661 /* Having a step-resume breakpoint overrides anything
3662 else having to do with stepping commands until
3663 that breakpoint is reached. */
3668 if (ecs
->event_thread
->step_range_end
== 0)
3671 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
3672 /* Likewise if we aren't even stepping. */
3677 /* If stepping through a line, keep going if still within it.
3679 Note that step_range_end is the address of the first instruction
3680 beyond the step range, and NOT the address of the last instruction
3683 Note also that during reverse execution, we may be stepping
3684 through a function epilogue and therefore must detect when
3685 the current-frame changes in the middle of a line. */
3687 if (stop_pc
>= ecs
->event_thread
->step_range_start
3688 && stop_pc
< ecs
->event_thread
->step_range_end
3689 && (execution_direction
!= EXEC_REVERSE
3690 || frame_id_eq (get_frame_id (frame
),
3691 ecs
->event_thread
->step_frame_id
)))
3695 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
3696 paddress (gdbarch
, ecs
->event_thread
->step_range_start
),
3697 paddress (gdbarch
, ecs
->event_thread
->step_range_end
));
3699 /* When stepping backward, stop at beginning of line range
3700 (unless it's the function entry point, in which case
3701 keep going back to the call point). */
3702 if (stop_pc
== ecs
->event_thread
->step_range_start
3703 && stop_pc
!= ecs
->stop_func_start
3704 && execution_direction
== EXEC_REVERSE
)
3706 ecs
->event_thread
->stop_step
= 1;
3707 print_stop_reason (END_STEPPING_RANGE
, 0);
3708 stop_stepping (ecs
);
3716 /* We stepped out of the stepping range. */
3718 /* If we are stepping at the source level and entered the runtime
3719 loader dynamic symbol resolution code...
3721 EXEC_FORWARD: we keep on single stepping until we exit the run
3722 time loader code and reach the callee's address.
3724 EXEC_REVERSE: we've already executed the callee (backward), and
3725 the runtime loader code is handled just like any other
3726 undebuggable function call. Now we need only keep stepping
3727 backward through the trampoline code, and that's handled further
3728 down, so there is nothing for us to do here. */
3730 if (execution_direction
!= EXEC_REVERSE
3731 && ecs
->event_thread
->step_over_calls
== STEP_OVER_UNDEBUGGABLE
3732 && in_solib_dynsym_resolve_code (stop_pc
))
3734 CORE_ADDR pc_after_resolver
=
3735 gdbarch_skip_solib_resolver (gdbarch
, stop_pc
);
3738 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into dynsym resolve code\n");
3740 if (pc_after_resolver
)
3742 /* Set up a step-resume breakpoint at the address
3743 indicated by SKIP_SOLIB_RESOLVER. */
3744 struct symtab_and_line sr_sal
;
3746 sr_sal
.pc
= pc_after_resolver
;
3748 insert_step_resume_breakpoint_at_sal (gdbarch
,
3749 sr_sal
, null_frame_id
);
3756 if (ecs
->event_thread
->step_range_end
!= 1
3757 && (ecs
->event_thread
->step_over_calls
== STEP_OVER_UNDEBUGGABLE
3758 || ecs
->event_thread
->step_over_calls
== STEP_OVER_ALL
)
3759 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
3762 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into signal trampoline\n");
3763 /* The inferior, while doing a "step" or "next", has ended up in
3764 a signal trampoline (either by a signal being delivered or by
3765 the signal handler returning). Just single-step until the
3766 inferior leaves the trampoline (either by calling the handler
3772 /* Check for subroutine calls. The check for the current frame
3773 equalling the step ID is not necessary - the check of the
3774 previous frame's ID is sufficient - but it is a common case and
3775 cheaper than checking the previous frame's ID.
3777 NOTE: frame_id_eq will never report two invalid frame IDs as
3778 being equal, so to get into this block, both the current and
3779 previous frame must have valid frame IDs. */
3780 if (!frame_id_eq (get_stack_frame_id (frame
),
3781 ecs
->event_thread
->step_stack_frame_id
)
3782 && frame_id_eq (frame_unwind_caller_id (frame
),
3783 ecs
->event_thread
->step_stack_frame_id
))
3785 CORE_ADDR real_stop_pc
;
3788 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
3790 if ((ecs
->event_thread
->step_over_calls
== STEP_OVER_NONE
)
3791 || ((ecs
->event_thread
->step_range_end
== 1)
3792 && in_prologue (gdbarch
, ecs
->event_thread
->prev_pc
,
3793 ecs
->stop_func_start
)))
3795 /* I presume that step_over_calls is only 0 when we're
3796 supposed to be stepping at the assembly language level
3797 ("stepi"). Just stop. */
3798 /* Also, maybe we just did a "nexti" inside a prolog, so we
3799 thought it was a subroutine call but it was not. Stop as
3801 /* And this works the same backward as frontward. MVS */
3802 ecs
->event_thread
->stop_step
= 1;
3803 print_stop_reason (END_STEPPING_RANGE
, 0);
3804 stop_stepping (ecs
);
3808 /* Reverse stepping through solib trampolines. */
3810 if (execution_direction
== EXEC_REVERSE
3811 && ecs
->event_thread
->step_over_calls
!= STEP_OVER_NONE
3812 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
3813 || (ecs
->stop_func_start
== 0
3814 && in_solib_dynsym_resolve_code (stop_pc
))))
3816 /* Any solib trampoline code can be handled in reverse
3817 by simply continuing to single-step. We have already
3818 executed the solib function (backwards), and a few
3819 steps will take us back through the trampoline to the
3825 if (ecs
->event_thread
->step_over_calls
== STEP_OVER_ALL
)
3827 /* We're doing a "next".
3829 Normal (forward) execution: set a breakpoint at the
3830 callee's return address (the address at which the caller
3833 Reverse (backward) execution. set the step-resume
3834 breakpoint at the start of the function that we just
3835 stepped into (backwards), and continue to there. When we
3836 get there, we'll need to single-step back to the caller. */
3838 if (execution_direction
== EXEC_REVERSE
)
3840 struct symtab_and_line sr_sal
;
3842 /* Normal function call return (static or dynamic). */
3844 sr_sal
.pc
= ecs
->stop_func_start
;
3845 insert_step_resume_breakpoint_at_sal (gdbarch
,
3846 sr_sal
, null_frame_id
);
3849 insert_step_resume_breakpoint_at_caller (frame
);
3855 /* If we are in a function call trampoline (a stub between the
3856 calling routine and the real function), locate the real
3857 function. That's what tells us (a) whether we want to step
3858 into it at all, and (b) what prologue we want to run to the
3859 end of, if we do step into it. */
3860 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
3861 if (real_stop_pc
== 0)
3862 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
3863 if (real_stop_pc
!= 0)
3864 ecs
->stop_func_start
= real_stop_pc
;
3866 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
3868 struct symtab_and_line sr_sal
;
3870 sr_sal
.pc
= ecs
->stop_func_start
;
3872 insert_step_resume_breakpoint_at_sal (gdbarch
,
3873 sr_sal
, null_frame_id
);
3878 /* If we have line number information for the function we are
3879 thinking of stepping into, step into it.
3881 If there are several symtabs at that PC (e.g. with include
3882 files), just want to know whether *any* of them have line
3883 numbers. find_pc_line handles this. */
3885 struct symtab_and_line tmp_sal
;
3887 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
3888 if (tmp_sal
.line
!= 0)
3890 if (execution_direction
== EXEC_REVERSE
)
3891 handle_step_into_function_backward (gdbarch
, ecs
);
3893 handle_step_into_function (gdbarch
, ecs
);
3898 /* If we have no line number and the step-stop-if-no-debug is
3899 set, we stop the step so that the user has a chance to switch
3900 in assembly mode. */
3901 if (ecs
->event_thread
->step_over_calls
== STEP_OVER_UNDEBUGGABLE
3902 && step_stop_if_no_debug
)
3904 ecs
->event_thread
->stop_step
= 1;
3905 print_stop_reason (END_STEPPING_RANGE
, 0);
3906 stop_stepping (ecs
);
3910 if (execution_direction
== EXEC_REVERSE
)
3912 /* Set a breakpoint at callee's start address.
3913 From there we can step once and be back in the caller. */
3914 struct symtab_and_line sr_sal
;
3916 sr_sal
.pc
= ecs
->stop_func_start
;
3917 insert_step_resume_breakpoint_at_sal (gdbarch
,
3918 sr_sal
, null_frame_id
);
3921 /* Set a breakpoint at callee's return address (the address
3922 at which the caller will resume). */
3923 insert_step_resume_breakpoint_at_caller (frame
);
3929 /* Reverse stepping through solib trampolines. */
3931 if (execution_direction
== EXEC_REVERSE
3932 && ecs
->event_thread
->step_over_calls
!= STEP_OVER_NONE
)
3934 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
3935 || (ecs
->stop_func_start
== 0
3936 && in_solib_dynsym_resolve_code (stop_pc
)))
3938 /* Any solib trampoline code can be handled in reverse
3939 by simply continuing to single-step. We have already
3940 executed the solib function (backwards), and a few
3941 steps will take us back through the trampoline to the
3946 else if (in_solib_dynsym_resolve_code (stop_pc
))
3948 /* Stepped backward into the solib dynsym resolver.
3949 Set a breakpoint at its start and continue, then
3950 one more step will take us out. */
3951 struct symtab_and_line sr_sal
;
3953 sr_sal
.pc
= ecs
->stop_func_start
;
3954 insert_step_resume_breakpoint_at_sal (gdbarch
,
3955 sr_sal
, null_frame_id
);
3961 /* If we're in the return path from a shared library trampoline,
3962 we want to proceed through the trampoline when stepping. */
3963 if (gdbarch_in_solib_return_trampoline (gdbarch
,
3964 stop_pc
, ecs
->stop_func_name
))
3966 /* Determine where this trampoline returns. */
3967 CORE_ADDR real_stop_pc
;
3968 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
3971 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into solib return tramp\n");
3973 /* Only proceed through if we know where it's going. */
3976 /* And put the step-breakpoint there and go until there. */
3977 struct symtab_and_line sr_sal
;
3979 init_sal (&sr_sal
); /* initialize to zeroes */
3980 sr_sal
.pc
= real_stop_pc
;
3981 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
3983 /* Do not specify what the fp should be when we stop since
3984 on some machines the prologue is where the new fp value
3986 insert_step_resume_breakpoint_at_sal (gdbarch
,
3987 sr_sal
, null_frame_id
);
3989 /* Restart without fiddling with the step ranges or
3996 stop_pc_sal
= find_pc_line (stop_pc
, 0);
3998 /* NOTE: tausq/2004-05-24: This if block used to be done before all
3999 the trampoline processing logic, however, there are some trampolines
4000 that have no names, so we should do trampoline handling first. */
4001 if (ecs
->event_thread
->step_over_calls
== STEP_OVER_UNDEBUGGABLE
4002 && ecs
->stop_func_name
== NULL
4003 && stop_pc_sal
.line
== 0)
4006 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into undebuggable function\n");
4008 /* The inferior just stepped into, or returned to, an
4009 undebuggable function (where there is no debugging information
4010 and no line number corresponding to the address where the
4011 inferior stopped). Since we want to skip this kind of code,
4012 we keep going until the inferior returns from this
4013 function - unless the user has asked us not to (via
4014 set step-mode) or we no longer know how to get back
4015 to the call site. */
4016 if (step_stop_if_no_debug
4017 || !frame_id_p (frame_unwind_caller_id (frame
)))
4019 /* If we have no line number and the step-stop-if-no-debug
4020 is set, we stop the step so that the user has a chance to
4021 switch in assembly mode. */
4022 ecs
->event_thread
->stop_step
= 1;
4023 print_stop_reason (END_STEPPING_RANGE
, 0);
4024 stop_stepping (ecs
);
4029 /* Set a breakpoint at callee's return address (the address
4030 at which the caller will resume). */
4031 insert_step_resume_breakpoint_at_caller (frame
);
4037 if (ecs
->event_thread
->step_range_end
== 1)
4039 /* It is stepi or nexti. We always want to stop stepping after
4042 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
4043 ecs
->event_thread
->stop_step
= 1;
4044 print_stop_reason (END_STEPPING_RANGE
, 0);
4045 stop_stepping (ecs
);
4049 if (stop_pc_sal
.line
== 0)
4051 /* We have no line number information. That means to stop
4052 stepping (does this always happen right after one instruction,
4053 when we do "s" in a function with no line numbers,
4054 or can this happen as a result of a return or longjmp?). */
4056 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
4057 ecs
->event_thread
->stop_step
= 1;
4058 print_stop_reason (END_STEPPING_RANGE
, 0);
4059 stop_stepping (ecs
);
4063 /* Look for "calls" to inlined functions, part one. If the inline
4064 frame machinery detected some skipped call sites, we have entered
4065 a new inline function. */
4067 if (frame_id_eq (get_frame_id (get_current_frame ()),
4068 ecs
->event_thread
->step_frame_id
)
4069 && inline_skipped_frames (ecs
->ptid
))
4071 struct symtab_and_line call_sal
;
4074 fprintf_unfiltered (gdb_stdlog
,
4075 "infrun: stepped into inlined function\n");
4077 find_frame_sal (get_current_frame (), &call_sal
);
4079 if (ecs
->event_thread
->step_over_calls
!= STEP_OVER_ALL
)
4081 /* For "step", we're going to stop. But if the call site
4082 for this inlined function is on the same source line as
4083 we were previously stepping, go down into the function
4084 first. Otherwise stop at the call site. */
4086 if (call_sal
.line
== ecs
->event_thread
->current_line
4087 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
4088 step_into_inline_frame (ecs
->ptid
);
4090 ecs
->event_thread
->stop_step
= 1;
4091 print_stop_reason (END_STEPPING_RANGE
, 0);
4092 stop_stepping (ecs
);
4097 /* For "next", we should stop at the call site if it is on a
4098 different source line. Otherwise continue through the
4099 inlined function. */
4100 if (call_sal
.line
== ecs
->event_thread
->current_line
4101 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
4105 ecs
->event_thread
->stop_step
= 1;
4106 print_stop_reason (END_STEPPING_RANGE
, 0);
4107 stop_stepping (ecs
);
4113 /* Look for "calls" to inlined functions, part two. If we are still
4114 in the same real function we were stepping through, but we have
4115 to go further up to find the exact frame ID, we are stepping
4116 through a more inlined call beyond its call site. */
4118 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
4119 && !frame_id_eq (get_frame_id (get_current_frame ()),
4120 ecs
->event_thread
->step_frame_id
)
4121 && stepped_in_from (get_current_frame (),
4122 ecs
->event_thread
->step_frame_id
))
4125 fprintf_unfiltered (gdb_stdlog
,
4126 "infrun: stepping through inlined function\n");
4128 if (ecs
->event_thread
->step_over_calls
== STEP_OVER_ALL
)
4132 ecs
->event_thread
->stop_step
= 1;
4133 print_stop_reason (END_STEPPING_RANGE
, 0);
4134 stop_stepping (ecs
);
4139 if ((stop_pc
== stop_pc_sal
.pc
)
4140 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
4141 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
4143 /* We are at the start of a different line. So stop. Note that
4144 we don't stop if we step into the middle of a different line.
4145 That is said to make things like for (;;) statements work
4148 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped to a different line\n");
4149 ecs
->event_thread
->stop_step
= 1;
4150 print_stop_reason (END_STEPPING_RANGE
, 0);
4151 stop_stepping (ecs
);
4155 /* We aren't done stepping.
4157 Optimize by setting the stepping range to the line.
4158 (We might not be in the original line, but if we entered a
4159 new line in mid-statement, we continue stepping. This makes
4160 things like for(;;) statements work better.) */
4162 ecs
->event_thread
->step_range_start
= stop_pc_sal
.pc
;
4163 ecs
->event_thread
->step_range_end
= stop_pc_sal
.end
;
4164 set_step_info (frame
, stop_pc_sal
);
4167 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
4171 /* Is thread TP in the middle of single-stepping? */
4174 currently_stepping (struct thread_info
*tp
)
4176 return ((tp
->step_range_end
&& tp
->step_resume_breakpoint
== NULL
)
4177 || tp
->trap_expected
4178 || tp
->stepping_through_solib_after_catch
4179 || bpstat_should_step ());
4182 /* Returns true if any thread *but* the one passed in "data" is in the
4183 middle of stepping or of handling a "next". */
4186 currently_stepping_or_nexting_callback (struct thread_info
*tp
, void *data
)
4191 return (tp
->step_range_end
4192 || tp
->trap_expected
4193 || tp
->stepping_through_solib_after_catch
);
4196 /* Inferior has stepped into a subroutine call with source code that
4197 we should not step over. Do step to the first line of code in
4201 handle_step_into_function (struct gdbarch
*gdbarch
,
4202 struct execution_control_state
*ecs
)
4205 struct symtab_and_line stop_func_sal
, sr_sal
;
4207 s
= find_pc_symtab (stop_pc
);
4208 if (s
&& s
->language
!= language_asm
)
4209 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
4210 ecs
->stop_func_start
);
4212 stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
4213 /* Use the step_resume_break to step until the end of the prologue,
4214 even if that involves jumps (as it seems to on the vax under
4216 /* If the prologue ends in the middle of a source line, continue to
4217 the end of that source line (if it is still within the function).
4218 Otherwise, just go to end of prologue. */
4219 if (stop_func_sal
.end
4220 && stop_func_sal
.pc
!= ecs
->stop_func_start
4221 && stop_func_sal
.end
< ecs
->stop_func_end
)
4222 ecs
->stop_func_start
= stop_func_sal
.end
;
4224 /* Architectures which require breakpoint adjustment might not be able
4225 to place a breakpoint at the computed address. If so, the test
4226 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
4227 ecs->stop_func_start to an address at which a breakpoint may be
4228 legitimately placed.
4230 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
4231 made, GDB will enter an infinite loop when stepping through
4232 optimized code consisting of VLIW instructions which contain
4233 subinstructions corresponding to different source lines. On
4234 FR-V, it's not permitted to place a breakpoint on any but the
4235 first subinstruction of a VLIW instruction. When a breakpoint is
4236 set, GDB will adjust the breakpoint address to the beginning of
4237 the VLIW instruction. Thus, we need to make the corresponding
4238 adjustment here when computing the stop address. */
4240 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
4242 ecs
->stop_func_start
4243 = gdbarch_adjust_breakpoint_address (gdbarch
,
4244 ecs
->stop_func_start
);
4247 if (ecs
->stop_func_start
== stop_pc
)
4249 /* We are already there: stop now. */
4250 ecs
->event_thread
->stop_step
= 1;
4251 print_stop_reason (END_STEPPING_RANGE
, 0);
4252 stop_stepping (ecs
);
4257 /* Put the step-breakpoint there and go until there. */
4258 init_sal (&sr_sal
); /* initialize to zeroes */
4259 sr_sal
.pc
= ecs
->stop_func_start
;
4260 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
4262 /* Do not specify what the fp should be when we stop since on
4263 some machines the prologue is where the new fp value is
4265 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
4267 /* And make sure stepping stops right away then. */
4268 ecs
->event_thread
->step_range_end
= ecs
->event_thread
->step_range_start
;
4273 /* Inferior has stepped backward into a subroutine call with source
4274 code that we should not step over. Do step to the beginning of the
4275 last line of code in it. */
4278 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
4279 struct execution_control_state
*ecs
)
4282 struct symtab_and_line stop_func_sal
, sr_sal
;
4284 s
= find_pc_symtab (stop_pc
);
4285 if (s
&& s
->language
!= language_asm
)
4286 ecs
->stop_func_start
= gdbarch_skip_prologue (gdbarch
,
4287 ecs
->stop_func_start
);
4289 stop_func_sal
= find_pc_line (stop_pc
, 0);
4291 /* OK, we're just going to keep stepping here. */
4292 if (stop_func_sal
.pc
== stop_pc
)
4294 /* We're there already. Just stop stepping now. */
4295 ecs
->event_thread
->stop_step
= 1;
4296 print_stop_reason (END_STEPPING_RANGE
, 0);
4297 stop_stepping (ecs
);
4301 /* Else just reset the step range and keep going.
4302 No step-resume breakpoint, they don't work for
4303 epilogues, which can have multiple entry paths. */
4304 ecs
->event_thread
->step_range_start
= stop_func_sal
.pc
;
4305 ecs
->event_thread
->step_range_end
= stop_func_sal
.end
;
4311 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
4312 This is used to both functions and to skip over code. */
4315 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
4316 struct symtab_and_line sr_sal
,
4317 struct frame_id sr_id
)
4319 /* There should never be more than one step-resume or longjmp-resume
4320 breakpoint per thread, so we should never be setting a new
4321 step_resume_breakpoint when one is already active. */
4322 gdb_assert (inferior_thread ()->step_resume_breakpoint
== NULL
);
4325 fprintf_unfiltered (gdb_stdlog
,
4326 "infrun: inserting step-resume breakpoint at %s\n",
4327 paddress (gdbarch
, sr_sal
.pc
));
4329 inferior_thread ()->step_resume_breakpoint
4330 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, bp_step_resume
);
4333 /* Insert a "step-resume breakpoint" at RETURN_FRAME.pc. This is used
4334 to skip a potential signal handler.
4336 This is called with the interrupted function's frame. The signal
4337 handler, when it returns, will resume the interrupted function at
4341 insert_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
4343 struct symtab_and_line sr_sal
;
4344 struct gdbarch
*gdbarch
;
4346 gdb_assert (return_frame
!= NULL
);
4347 init_sal (&sr_sal
); /* initialize to zeros */
4349 gdbarch
= get_frame_arch (return_frame
);
4350 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
4351 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
4353 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
4354 get_stack_frame_id (return_frame
));
4357 /* Similar to insert_step_resume_breakpoint_at_frame, except
4358 but a breakpoint at the previous frame's PC. This is used to
4359 skip a function after stepping into it (for "next" or if the called
4360 function has no debugging information).
4362 The current function has almost always been reached by single
4363 stepping a call or return instruction. NEXT_FRAME belongs to the
4364 current function, and the breakpoint will be set at the caller's
4367 This is a separate function rather than reusing
4368 insert_step_resume_breakpoint_at_frame in order to avoid
4369 get_prev_frame, which may stop prematurely (see the implementation
4370 of frame_unwind_caller_id for an example). */
4373 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
4375 struct symtab_and_line sr_sal
;
4376 struct gdbarch
*gdbarch
;
4378 /* We shouldn't have gotten here if we don't know where the call site
4380 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
4382 init_sal (&sr_sal
); /* initialize to zeros */
4384 gdbarch
= frame_unwind_caller_arch (next_frame
);
4385 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
4386 frame_unwind_caller_pc (next_frame
));
4387 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
4389 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
4390 frame_unwind_caller_id (next_frame
));
4393 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
4394 new breakpoint at the target of a jmp_buf. The handling of
4395 longjmp-resume uses the same mechanisms used for handling
4396 "step-resume" breakpoints. */
4399 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
4401 /* There should never be more than one step-resume or longjmp-resume
4402 breakpoint per thread, so we should never be setting a new
4403 longjmp_resume_breakpoint when one is already active. */
4404 gdb_assert (inferior_thread ()->step_resume_breakpoint
== NULL
);
4407 fprintf_unfiltered (gdb_stdlog
,
4408 "infrun: inserting longjmp-resume breakpoint at %s\n",
4409 paddress (gdbarch
, pc
));
4411 inferior_thread ()->step_resume_breakpoint
=
4412 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
);
4416 stop_stepping (struct execution_control_state
*ecs
)
4419 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_stepping\n");
4421 /* Let callers know we don't want to wait for the inferior anymore. */
4422 ecs
->wait_some_more
= 0;
4425 /* This function handles various cases where we need to continue
4426 waiting for the inferior. */
4427 /* (Used to be the keep_going: label in the old wait_for_inferior) */
4430 keep_going (struct execution_control_state
*ecs
)
4432 /* Save the pc before execution, to compare with pc after stop. */
4433 ecs
->event_thread
->prev_pc
4434 = regcache_read_pc (get_thread_regcache (ecs
->ptid
));
4436 /* If we did not do break;, it means we should keep running the
4437 inferior and not return to debugger. */
4439 if (ecs
->event_thread
->trap_expected
4440 && ecs
->event_thread
->stop_signal
!= TARGET_SIGNAL_TRAP
)
4442 /* We took a signal (which we are supposed to pass through to
4443 the inferior, else we'd not get here) and we haven't yet
4444 gotten our trap. Simply continue. */
4445 resume (currently_stepping (ecs
->event_thread
),
4446 ecs
->event_thread
->stop_signal
);
4450 /* Either the trap was not expected, but we are continuing
4451 anyway (the user asked that this signal be passed to the
4454 The signal was SIGTRAP, e.g. it was our signal, but we
4455 decided we should resume from it.
4457 We're going to run this baby now!
4459 Note that insert_breakpoints won't try to re-insert
4460 already inserted breakpoints. Therefore, we don't
4461 care if breakpoints were already inserted, or not. */
4463 if (ecs
->event_thread
->stepping_over_breakpoint
)
4465 struct regcache
*thread_regcache
= get_thread_regcache (ecs
->ptid
);
4466 if (!use_displaced_stepping (get_regcache_arch (thread_regcache
)))
4467 /* Since we can't do a displaced step, we have to remove
4468 the breakpoint while we step it. To keep things
4469 simple, we remove them all. */
4470 remove_breakpoints ();
4474 struct gdb_exception e
;
4475 /* Stop stepping when inserting breakpoints
4477 TRY_CATCH (e
, RETURN_MASK_ERROR
)
4479 insert_breakpoints ();
4483 stop_stepping (ecs
);
4488 ecs
->event_thread
->trap_expected
= ecs
->event_thread
->stepping_over_breakpoint
;
4490 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
4491 specifies that such a signal should be delivered to the
4494 Typically, this would occure when a user is debugging a
4495 target monitor on a simulator: the target monitor sets a
4496 breakpoint; the simulator encounters this break-point and
4497 halts the simulation handing control to GDB; GDB, noteing
4498 that the break-point isn't valid, returns control back to the
4499 simulator; the simulator then delivers the hardware
4500 equivalent of a SIGNAL_TRAP to the program being debugged. */
4502 if (ecs
->event_thread
->stop_signal
== TARGET_SIGNAL_TRAP
4503 && !signal_program
[ecs
->event_thread
->stop_signal
])
4504 ecs
->event_thread
->stop_signal
= TARGET_SIGNAL_0
;
4506 resume (currently_stepping (ecs
->event_thread
),
4507 ecs
->event_thread
->stop_signal
);
4510 prepare_to_wait (ecs
);
4513 /* This function normally comes after a resume, before
4514 handle_inferior_event exits. It takes care of any last bits of
4515 housekeeping, and sets the all-important wait_some_more flag. */
4518 prepare_to_wait (struct execution_control_state
*ecs
)
4521 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
4523 /* This is the old end of the while loop. Let everybody know we
4524 want to wait for the inferior some more and get called again
4526 ecs
->wait_some_more
= 1;
4529 /* Print why the inferior has stopped. We always print something when
4530 the inferior exits, or receives a signal. The rest of the cases are
4531 dealt with later on in normal_stop() and print_it_typical(). Ideally
4532 there should be a call to this function from handle_inferior_event()
4533 each time stop_stepping() is called.*/
4535 print_stop_reason (enum inferior_stop_reason stop_reason
, int stop_info
)
4537 switch (stop_reason
)
4539 case END_STEPPING_RANGE
:
4540 /* We are done with a step/next/si/ni command. */
4541 /* For now print nothing. */
4542 /* Print a message only if not in the middle of doing a "step n"
4543 operation for n > 1 */
4544 if (!inferior_thread ()->step_multi
4545 || !inferior_thread ()->stop_step
)
4546 if (ui_out_is_mi_like_p (uiout
))
4549 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
4552 /* The inferior was terminated by a signal. */
4553 annotate_signalled ();
4554 if (ui_out_is_mi_like_p (uiout
))
4557 async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
4558 ui_out_text (uiout
, "\nProgram terminated with signal ");
4559 annotate_signal_name ();
4560 ui_out_field_string (uiout
, "signal-name",
4561 target_signal_to_name (stop_info
));
4562 annotate_signal_name_end ();
4563 ui_out_text (uiout
, ", ");
4564 annotate_signal_string ();
4565 ui_out_field_string (uiout
, "signal-meaning",
4566 target_signal_to_string (stop_info
));
4567 annotate_signal_string_end ();
4568 ui_out_text (uiout
, ".\n");
4569 ui_out_text (uiout
, "The program no longer exists.\n");
4572 /* The inferior program is finished. */
4573 annotate_exited (stop_info
);
4576 if (ui_out_is_mi_like_p (uiout
))
4577 ui_out_field_string (uiout
, "reason",
4578 async_reason_lookup (EXEC_ASYNC_EXITED
));
4579 ui_out_text (uiout
, "\nProgram exited with code ");
4580 ui_out_field_fmt (uiout
, "exit-code", "0%o",
4581 (unsigned int) stop_info
);
4582 ui_out_text (uiout
, ".\n");
4586 if (ui_out_is_mi_like_p (uiout
))
4589 async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
4590 ui_out_text (uiout
, "\nProgram exited normally.\n");
4592 /* Support the --return-child-result option. */
4593 return_child_result_value
= stop_info
;
4595 case SIGNAL_RECEIVED
:
4596 /* Signal received. The signal table tells us to print about
4600 if (stop_info
== TARGET_SIGNAL_0
&& !ui_out_is_mi_like_p (uiout
))
4602 struct thread_info
*t
= inferior_thread ();
4604 ui_out_text (uiout
, "\n[");
4605 ui_out_field_string (uiout
, "thread-name",
4606 target_pid_to_str (t
->ptid
));
4607 ui_out_field_fmt (uiout
, "thread-id", "] #%d", t
->num
);
4608 ui_out_text (uiout
, " stopped");
4612 ui_out_text (uiout
, "\nProgram received signal ");
4613 annotate_signal_name ();
4614 if (ui_out_is_mi_like_p (uiout
))
4616 (uiout
, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
4617 ui_out_field_string (uiout
, "signal-name",
4618 target_signal_to_name (stop_info
));
4619 annotate_signal_name_end ();
4620 ui_out_text (uiout
, ", ");
4621 annotate_signal_string ();
4622 ui_out_field_string (uiout
, "signal-meaning",
4623 target_signal_to_string (stop_info
));
4624 annotate_signal_string_end ();
4626 ui_out_text (uiout
, ".\n");
4629 /* Reverse execution: target ran out of history info. */
4630 ui_out_text (uiout
, "\nNo more reverse-execution history.\n");
4633 internal_error (__FILE__
, __LINE__
,
4634 _("print_stop_reason: unrecognized enum value"));
4640 /* Here to return control to GDB when the inferior stops for real.
4641 Print appropriate messages, remove breakpoints, give terminal our modes.
4643 STOP_PRINT_FRAME nonzero means print the executing frame
4644 (pc, function, args, file, line number and line text).
4645 BREAKPOINTS_FAILED nonzero means stop was due to error
4646 attempting to insert breakpoints. */
4651 struct target_waitstatus last
;
4653 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
4655 get_last_target_status (&last_ptid
, &last
);
4657 /* If an exception is thrown from this point on, make sure to
4658 propagate GDB's knowledge of the executing state to the
4659 frontend/user running state. A QUIT is an easy exception to see
4660 here, so do this before any filtered output. */
4662 make_cleanup (finish_thread_state_cleanup
, &minus_one_ptid
);
4663 else if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
4664 && last
.kind
!= TARGET_WAITKIND_EXITED
)
4665 make_cleanup (finish_thread_state_cleanup
, &inferior_ptid
);
4667 /* In non-stop mode, we don't want GDB to switch threads behind the
4668 user's back, to avoid races where the user is typing a command to
4669 apply to thread x, but GDB switches to thread y before the user
4670 finishes entering the command. */
4672 /* As with the notification of thread events, we want to delay
4673 notifying the user that we've switched thread context until
4674 the inferior actually stops.
4676 There's no point in saying anything if the inferior has exited.
4677 Note that SIGNALLED here means "exited with a signal", not
4678 "received a signal". */
4680 && !ptid_equal (previous_inferior_ptid
, inferior_ptid
)
4681 && target_has_execution
4682 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
4683 && last
.kind
!= TARGET_WAITKIND_EXITED
)
4685 target_terminal_ours_for_output ();
4686 printf_filtered (_("[Switching to %s]\n"),
4687 target_pid_to_str (inferior_ptid
));
4688 annotate_thread_changed ();
4689 previous_inferior_ptid
= inferior_ptid
;
4692 if (!breakpoints_always_inserted_mode () && target_has_execution
)
4694 if (remove_breakpoints ())
4696 target_terminal_ours_for_output ();
4697 printf_filtered (_("\
4698 Cannot remove breakpoints because program is no longer writable.\n\
4699 Further execution is probably impossible.\n"));
4703 /* If an auto-display called a function and that got a signal,
4704 delete that auto-display to avoid an infinite recursion. */
4706 if (stopped_by_random_signal
)
4707 disable_current_display ();
4709 /* Don't print a message if in the middle of doing a "step n"
4710 operation for n > 1 */
4711 if (target_has_execution
4712 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
4713 && last
.kind
!= TARGET_WAITKIND_EXITED
4714 && inferior_thread ()->step_multi
4715 && inferior_thread ()->stop_step
)
4718 target_terminal_ours ();
4720 /* Set the current source location. This will also happen if we
4721 display the frame below, but the current SAL will be incorrect
4722 during a user hook-stop function. */
4723 if (has_stack_frames () && !stop_stack_dummy
)
4724 set_current_sal_from_frame (get_current_frame (), 1);
4726 /* Let the user/frontend see the threads as stopped. */
4727 do_cleanups (old_chain
);
4729 /* Look up the hook_stop and run it (CLI internally handles problem
4730 of stop_command's pre-hook not existing). */
4732 catch_errors (hook_stop_stub
, stop_command
,
4733 "Error while running hook_stop:\n", RETURN_MASK_ALL
);
4735 if (!has_stack_frames ())
4738 if (last
.kind
== TARGET_WAITKIND_SIGNALLED
4739 || last
.kind
== TARGET_WAITKIND_EXITED
)
4742 /* Select innermost stack frame - i.e., current frame is frame 0,
4743 and current location is based on that.
4744 Don't do this on return from a stack dummy routine,
4745 or if the program has exited. */
4747 if (!stop_stack_dummy
)
4749 select_frame (get_current_frame ());
4751 /* Print current location without a level number, if
4752 we have changed functions or hit a breakpoint.
4753 Print source line if we have one.
4754 bpstat_print() contains the logic deciding in detail
4755 what to print, based on the event(s) that just occurred. */
4757 /* If --batch-silent is enabled then there's no need to print the current
4758 source location, and to try risks causing an error message about
4759 missing source files. */
4760 if (stop_print_frame
&& !batch_silent
)
4764 int do_frame_printing
= 1;
4765 struct thread_info
*tp
= inferior_thread ();
4767 bpstat_ret
= bpstat_print (tp
->stop_bpstat
);
4771 /* If we had hit a shared library event breakpoint,
4772 bpstat_print would print out this message. If we hit
4773 an OS-level shared library event, do the same
4775 if (last
.kind
== TARGET_WAITKIND_LOADED
)
4777 printf_filtered (_("Stopped due to shared library event\n"));
4778 source_flag
= SRC_LINE
; /* something bogus */
4779 do_frame_printing
= 0;
4783 /* FIXME: cagney/2002-12-01: Given that a frame ID does
4784 (or should) carry around the function and does (or
4785 should) use that when doing a frame comparison. */
4787 && frame_id_eq (tp
->step_frame_id
,
4788 get_frame_id (get_current_frame ()))
4789 && step_start_function
== find_pc_function (stop_pc
))
4790 source_flag
= SRC_LINE
; /* finished step, just print source line */
4792 source_flag
= SRC_AND_LOC
; /* print location and source line */
4794 case PRINT_SRC_AND_LOC
:
4795 source_flag
= SRC_AND_LOC
; /* print location and source line */
4797 case PRINT_SRC_ONLY
:
4798 source_flag
= SRC_LINE
;
4801 source_flag
= SRC_LINE
; /* something bogus */
4802 do_frame_printing
= 0;
4805 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
4808 /* The behavior of this routine with respect to the source
4810 SRC_LINE: Print only source line
4811 LOCATION: Print only location
4812 SRC_AND_LOC: Print location and source line */
4813 if (do_frame_printing
)
4814 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
);
4816 /* Display the auto-display expressions. */
4821 /* Save the function value return registers, if we care.
4822 We might be about to restore their previous contents. */
4823 if (inferior_thread ()->proceed_to_finish
)
4825 /* This should not be necessary. */
4827 regcache_xfree (stop_registers
);
4829 /* NB: The copy goes through to the target picking up the value of
4830 all the registers. */
4831 stop_registers
= regcache_dup (get_current_regcache ());
4834 if (stop_stack_dummy
)
4836 /* Pop the empty frame that contains the stack dummy.
4837 This also restores inferior state prior to the call
4838 (struct inferior_thread_state). */
4839 struct frame_info
*frame
= get_current_frame ();
4840 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
4842 /* frame_pop() calls reinit_frame_cache as the last thing it does
4843 which means there's currently no selected frame. We don't need
4844 to re-establish a selected frame if the dummy call returns normally,
4845 that will be done by restore_inferior_status. However, we do have
4846 to handle the case where the dummy call is returning after being
4847 stopped (e.g. the dummy call previously hit a breakpoint). We
4848 can't know which case we have so just always re-establish a
4849 selected frame here. */
4850 select_frame (get_current_frame ());
4854 annotate_stopped ();
4856 /* Suppress the stop observer if we're in the middle of:
4858 - a step n (n > 1), as there still more steps to be done.
4860 - a "finish" command, as the observer will be called in
4861 finish_command_continuation, so it can include the inferior
4862 function's return value.
4864 - calling an inferior function, as we pretend we inferior didn't
4865 run at all. The return value of the call is handled by the
4866 expression evaluator, through call_function_by_hand. */
4868 if (!target_has_execution
4869 || last
.kind
== TARGET_WAITKIND_SIGNALLED
4870 || last
.kind
== TARGET_WAITKIND_EXITED
4871 || (!inferior_thread ()->step_multi
4872 && !(inferior_thread ()->stop_bpstat
4873 && inferior_thread ()->proceed_to_finish
)
4874 && !inferior_thread ()->in_infcall
))
4876 if (!ptid_equal (inferior_ptid
, null_ptid
))
4877 observer_notify_normal_stop (inferior_thread ()->stop_bpstat
,
4880 observer_notify_normal_stop (NULL
, stop_print_frame
);
4883 if (target_has_execution
)
4885 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
4886 && last
.kind
!= TARGET_WAITKIND_EXITED
)
4887 /* Delete the breakpoint we stopped at, if it wants to be deleted.
4888 Delete any breakpoint that is to be deleted at the next stop. */
4889 breakpoint_auto_delete (inferior_thread ()->stop_bpstat
);
4894 hook_stop_stub (void *cmd
)
4896 execute_cmd_pre_hook ((struct cmd_list_element
*) cmd
);
4901 signal_stop_state (int signo
)
4903 return signal_stop
[signo
];
4907 signal_print_state (int signo
)
4909 return signal_print
[signo
];
4913 signal_pass_state (int signo
)
4915 return signal_program
[signo
];
4919 signal_stop_update (int signo
, int state
)
4921 int ret
= signal_stop
[signo
];
4922 signal_stop
[signo
] = state
;
4927 signal_print_update (int signo
, int state
)
4929 int ret
= signal_print
[signo
];
4930 signal_print
[signo
] = state
;
4935 signal_pass_update (int signo
, int state
)
4937 int ret
= signal_program
[signo
];
4938 signal_program
[signo
] = state
;
4943 sig_print_header (void)
4945 printf_filtered (_("\
4946 Signal Stop\tPrint\tPass to program\tDescription\n"));
4950 sig_print_info (enum target_signal oursig
)
4952 const char *name
= target_signal_to_name (oursig
);
4953 int name_padding
= 13 - strlen (name
);
4955 if (name_padding
<= 0)
4958 printf_filtered ("%s", name
);
4959 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
4960 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
4961 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
4962 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
4963 printf_filtered ("%s\n", target_signal_to_string (oursig
));
4966 /* Specify how various signals in the inferior should be handled. */
4969 handle_command (char *args
, int from_tty
)
4972 int digits
, wordlen
;
4973 int sigfirst
, signum
, siglast
;
4974 enum target_signal oursig
;
4977 unsigned char *sigs
;
4978 struct cleanup
*old_chain
;
4982 error_no_arg (_("signal to handle"));
4985 /* Allocate and zero an array of flags for which signals to handle. */
4987 nsigs
= (int) TARGET_SIGNAL_LAST
;
4988 sigs
= (unsigned char *) alloca (nsigs
);
4989 memset (sigs
, 0, nsigs
);
4991 /* Break the command line up into args. */
4993 argv
= gdb_buildargv (args
);
4994 old_chain
= make_cleanup_freeargv (argv
);
4996 /* Walk through the args, looking for signal oursigs, signal names, and
4997 actions. Signal numbers and signal names may be interspersed with
4998 actions, with the actions being performed for all signals cumulatively
4999 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
5001 while (*argv
!= NULL
)
5003 wordlen
= strlen (*argv
);
5004 for (digits
= 0; isdigit ((*argv
)[digits
]); digits
++)
5008 sigfirst
= siglast
= -1;
5010 if (wordlen
>= 1 && !strncmp (*argv
, "all", wordlen
))
5012 /* Apply action to all signals except those used by the
5013 debugger. Silently skip those. */
5016 siglast
= nsigs
- 1;
5018 else if (wordlen
>= 1 && !strncmp (*argv
, "stop", wordlen
))
5020 SET_SIGS (nsigs
, sigs
, signal_stop
);
5021 SET_SIGS (nsigs
, sigs
, signal_print
);
5023 else if (wordlen
>= 1 && !strncmp (*argv
, "ignore", wordlen
))
5025 UNSET_SIGS (nsigs
, sigs
, signal_program
);
5027 else if (wordlen
>= 2 && !strncmp (*argv
, "print", wordlen
))
5029 SET_SIGS (nsigs
, sigs
, signal_print
);
5031 else if (wordlen
>= 2 && !strncmp (*argv
, "pass", wordlen
))
5033 SET_SIGS (nsigs
, sigs
, signal_program
);
5035 else if (wordlen
>= 3 && !strncmp (*argv
, "nostop", wordlen
))
5037 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
5039 else if (wordlen
>= 3 && !strncmp (*argv
, "noignore", wordlen
))
5041 SET_SIGS (nsigs
, sigs
, signal_program
);
5043 else if (wordlen
>= 4 && !strncmp (*argv
, "noprint", wordlen
))
5045 UNSET_SIGS (nsigs
, sigs
, signal_print
);
5046 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
5048 else if (wordlen
>= 4 && !strncmp (*argv
, "nopass", wordlen
))
5050 UNSET_SIGS (nsigs
, sigs
, signal_program
);
5052 else if (digits
> 0)
5054 /* It is numeric. The numeric signal refers to our own
5055 internal signal numbering from target.h, not to host/target
5056 signal number. This is a feature; users really should be
5057 using symbolic names anyway, and the common ones like
5058 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
5060 sigfirst
= siglast
= (int)
5061 target_signal_from_command (atoi (*argv
));
5062 if ((*argv
)[digits
] == '-')
5065 target_signal_from_command (atoi ((*argv
) + digits
+ 1));
5067 if (sigfirst
> siglast
)
5069 /* Bet he didn't figure we'd think of this case... */
5077 oursig
= target_signal_from_name (*argv
);
5078 if (oursig
!= TARGET_SIGNAL_UNKNOWN
)
5080 sigfirst
= siglast
= (int) oursig
;
5084 /* Not a number and not a recognized flag word => complain. */
5085 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv
);
5089 /* If any signal numbers or symbol names were found, set flags for
5090 which signals to apply actions to. */
5092 for (signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
5094 switch ((enum target_signal
) signum
)
5096 case TARGET_SIGNAL_TRAP
:
5097 case TARGET_SIGNAL_INT
:
5098 if (!allsigs
&& !sigs
[signum
])
5100 if (query (_("%s is used by the debugger.\n\
5101 Are you sure you want to change it? "), target_signal_to_name ((enum target_signal
) signum
)))
5107 printf_unfiltered (_("Not confirmed, unchanged.\n"));
5108 gdb_flush (gdb_stdout
);
5112 case TARGET_SIGNAL_0
:
5113 case TARGET_SIGNAL_DEFAULT
:
5114 case TARGET_SIGNAL_UNKNOWN
:
5115 /* Make sure that "all" doesn't print these. */
5126 for (signum
= 0; signum
< nsigs
; signum
++)
5129 target_notice_signals (inferior_ptid
);
5133 /* Show the results. */
5134 sig_print_header ();
5135 for (; signum
< nsigs
; signum
++)
5137 sig_print_info (signum
);
5143 do_cleanups (old_chain
);
5147 xdb_handle_command (char *args
, int from_tty
)
5150 struct cleanup
*old_chain
;
5153 error_no_arg (_("xdb command"));
5155 /* Break the command line up into args. */
5157 argv
= gdb_buildargv (args
);
5158 old_chain
= make_cleanup_freeargv (argv
);
5159 if (argv
[1] != (char *) NULL
)
5164 bufLen
= strlen (argv
[0]) + 20;
5165 argBuf
= (char *) xmalloc (bufLen
);
5169 enum target_signal oursig
;
5171 oursig
= target_signal_from_name (argv
[0]);
5172 memset (argBuf
, 0, bufLen
);
5173 if (strcmp (argv
[1], "Q") == 0)
5174 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
5177 if (strcmp (argv
[1], "s") == 0)
5179 if (!signal_stop
[oursig
])
5180 sprintf (argBuf
, "%s %s", argv
[0], "stop");
5182 sprintf (argBuf
, "%s %s", argv
[0], "nostop");
5184 else if (strcmp (argv
[1], "i") == 0)
5186 if (!signal_program
[oursig
])
5187 sprintf (argBuf
, "%s %s", argv
[0], "pass");
5189 sprintf (argBuf
, "%s %s", argv
[0], "nopass");
5191 else if (strcmp (argv
[1], "r") == 0)
5193 if (!signal_print
[oursig
])
5194 sprintf (argBuf
, "%s %s", argv
[0], "print");
5196 sprintf (argBuf
, "%s %s", argv
[0], "noprint");
5202 handle_command (argBuf
, from_tty
);
5204 printf_filtered (_("Invalid signal handling flag.\n"));
5209 do_cleanups (old_chain
);
5212 /* Print current contents of the tables set by the handle command.
5213 It is possible we should just be printing signals actually used
5214 by the current target (but for things to work right when switching
5215 targets, all signals should be in the signal tables). */
5218 signals_info (char *signum_exp
, int from_tty
)
5220 enum target_signal oursig
;
5221 sig_print_header ();
5225 /* First see if this is a symbol name. */
5226 oursig
= target_signal_from_name (signum_exp
);
5227 if (oursig
== TARGET_SIGNAL_UNKNOWN
)
5229 /* No, try numeric. */
5231 target_signal_from_command (parse_and_eval_long (signum_exp
));
5233 sig_print_info (oursig
);
5237 printf_filtered ("\n");
5238 /* These ugly casts brought to you by the native VAX compiler. */
5239 for (oursig
= TARGET_SIGNAL_FIRST
;
5240 (int) oursig
< (int) TARGET_SIGNAL_LAST
;
5241 oursig
= (enum target_signal
) ((int) oursig
+ 1))
5245 if (oursig
!= TARGET_SIGNAL_UNKNOWN
5246 && oursig
!= TARGET_SIGNAL_DEFAULT
&& oursig
!= TARGET_SIGNAL_0
)
5247 sig_print_info (oursig
);
5250 printf_filtered (_("\nUse the \"handle\" command to change these tables.\n"));
5253 /* The $_siginfo convenience variable is a bit special. We don't know
5254 for sure the type of the value until we actually have a chance to
5255 fetch the data. The type can change depending on gdbarch, so it it
5256 also dependent on which thread you have selected.
5258 1. making $_siginfo be an internalvar that creates a new value on
5261 2. making the value of $_siginfo be an lval_computed value. */
5263 /* This function implements the lval_computed support for reading a
5267 siginfo_value_read (struct value
*v
)
5269 LONGEST transferred
;
5272 target_read (¤t_target
, TARGET_OBJECT_SIGNAL_INFO
,
5274 value_contents_all_raw (v
),
5276 TYPE_LENGTH (value_type (v
)));
5278 if (transferred
!= TYPE_LENGTH (value_type (v
)))
5279 error (_("Unable to read siginfo"));
5282 /* This function implements the lval_computed support for writing a
5286 siginfo_value_write (struct value
*v
, struct value
*fromval
)
5288 LONGEST transferred
;
5290 transferred
= target_write (¤t_target
,
5291 TARGET_OBJECT_SIGNAL_INFO
,
5293 value_contents_all_raw (fromval
),
5295 TYPE_LENGTH (value_type (fromval
)));
5297 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
5298 error (_("Unable to write siginfo"));
5301 static struct lval_funcs siginfo_value_funcs
=
5307 /* Return a new value with the correct type for the siginfo object of
5308 the current thread using architecture GDBARCH. Return a void value
5309 if there's no object available. */
5311 static struct value
*
5312 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
)
5314 if (target_has_stack
5315 && !ptid_equal (inferior_ptid
, null_ptid
)
5316 && gdbarch_get_siginfo_type_p (gdbarch
))
5318 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
5319 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
5322 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
5326 /* Inferior thread state.
5327 These are details related to the inferior itself, and don't include
5328 things like what frame the user had selected or what gdb was doing
5329 with the target at the time.
5330 For inferior function calls these are things we want to restore
5331 regardless of whether the function call successfully completes
5332 or the dummy frame has to be manually popped. */
5334 struct inferior_thread_state
5336 enum target_signal stop_signal
;
5338 struct regcache
*registers
;
5341 struct inferior_thread_state
*
5342 save_inferior_thread_state (void)
5344 struct inferior_thread_state
*inf_state
= XMALLOC (struct inferior_thread_state
);
5345 struct thread_info
*tp
= inferior_thread ();
5347 inf_state
->stop_signal
= tp
->stop_signal
;
5348 inf_state
->stop_pc
= stop_pc
;
5350 inf_state
->registers
= regcache_dup (get_current_regcache ());
5355 /* Restore inferior session state to INF_STATE. */
5358 restore_inferior_thread_state (struct inferior_thread_state
*inf_state
)
5360 struct thread_info
*tp
= inferior_thread ();
5362 tp
->stop_signal
= inf_state
->stop_signal
;
5363 stop_pc
= inf_state
->stop_pc
;
5365 /* The inferior can be gone if the user types "print exit(0)"
5366 (and perhaps other times). */
5367 if (target_has_execution
)
5368 /* NB: The register write goes through to the target. */
5369 regcache_cpy (get_current_regcache (), inf_state
->registers
);
5370 regcache_xfree (inf_state
->registers
);
5375 do_restore_inferior_thread_state_cleanup (void *state
)
5377 restore_inferior_thread_state (state
);
5381 make_cleanup_restore_inferior_thread_state (struct inferior_thread_state
*inf_state
)
5383 return make_cleanup (do_restore_inferior_thread_state_cleanup
, inf_state
);
5387 discard_inferior_thread_state (struct inferior_thread_state
*inf_state
)
5389 regcache_xfree (inf_state
->registers
);
5394 get_inferior_thread_state_regcache (struct inferior_thread_state
*inf_state
)
5396 return inf_state
->registers
;
5399 /* Session related state for inferior function calls.
5400 These are the additional bits of state that need to be restored
5401 when an inferior function call successfully completes. */
5403 struct inferior_status
5407 int stop_stack_dummy
;
5408 int stopped_by_random_signal
;
5409 int stepping_over_breakpoint
;
5410 CORE_ADDR step_range_start
;
5411 CORE_ADDR step_range_end
;
5412 struct frame_id step_frame_id
;
5413 struct frame_id step_stack_frame_id
;
5414 enum step_over_calls_kind step_over_calls
;
5415 CORE_ADDR step_resume_break_address
;
5416 int stop_after_trap
;
5419 /* ID if the selected frame when the inferior function call was made. */
5420 struct frame_id selected_frame_id
;
5422 int proceed_to_finish
;
5426 /* Save all of the information associated with the inferior<==>gdb
5429 struct inferior_status
*
5430 save_inferior_status (void)
5432 struct inferior_status
*inf_status
= XMALLOC (struct inferior_status
);
5433 struct thread_info
*tp
= inferior_thread ();
5434 struct inferior
*inf
= current_inferior ();
5436 inf_status
->stop_step
= tp
->stop_step
;
5437 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
5438 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
5439 inf_status
->stepping_over_breakpoint
= tp
->trap_expected
;
5440 inf_status
->step_range_start
= tp
->step_range_start
;
5441 inf_status
->step_range_end
= tp
->step_range_end
;
5442 inf_status
->step_frame_id
= tp
->step_frame_id
;
5443 inf_status
->step_stack_frame_id
= tp
->step_stack_frame_id
;
5444 inf_status
->step_over_calls
= tp
->step_over_calls
;
5445 inf_status
->stop_after_trap
= stop_after_trap
;
5446 inf_status
->stop_soon
= inf
->stop_soon
;
5447 /* Save original bpstat chain here; replace it with copy of chain.
5448 If caller's caller is walking the chain, they'll be happier if we
5449 hand them back the original chain when restore_inferior_status is
5451 inf_status
->stop_bpstat
= tp
->stop_bpstat
;
5452 tp
->stop_bpstat
= bpstat_copy (tp
->stop_bpstat
);
5453 inf_status
->proceed_to_finish
= tp
->proceed_to_finish
;
5454 inf_status
->in_infcall
= tp
->in_infcall
;
5456 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
5462 restore_selected_frame (void *args
)
5464 struct frame_id
*fid
= (struct frame_id
*) args
;
5465 struct frame_info
*frame
;
5467 frame
= frame_find_by_id (*fid
);
5469 /* If inf_status->selected_frame_id is NULL, there was no previously
5473 warning (_("Unable to restore previously selected frame."));
5477 select_frame (frame
);
5482 /* Restore inferior session state to INF_STATUS. */
5485 restore_inferior_status (struct inferior_status
*inf_status
)
5487 struct thread_info
*tp
= inferior_thread ();
5488 struct inferior
*inf
= current_inferior ();
5490 tp
->stop_step
= inf_status
->stop_step
;
5491 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
5492 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
5493 tp
->trap_expected
= inf_status
->stepping_over_breakpoint
;
5494 tp
->step_range_start
= inf_status
->step_range_start
;
5495 tp
->step_range_end
= inf_status
->step_range_end
;
5496 tp
->step_frame_id
= inf_status
->step_frame_id
;
5497 tp
->step_stack_frame_id
= inf_status
->step_stack_frame_id
;
5498 tp
->step_over_calls
= inf_status
->step_over_calls
;
5499 stop_after_trap
= inf_status
->stop_after_trap
;
5500 inf
->stop_soon
= inf_status
->stop_soon
;
5501 bpstat_clear (&tp
->stop_bpstat
);
5502 tp
->stop_bpstat
= inf_status
->stop_bpstat
;
5503 inf_status
->stop_bpstat
= NULL
;
5504 tp
->proceed_to_finish
= inf_status
->proceed_to_finish
;
5505 tp
->in_infcall
= inf_status
->in_infcall
;
5507 if (target_has_stack
)
5509 /* The point of catch_errors is that if the stack is clobbered,
5510 walking the stack might encounter a garbage pointer and
5511 error() trying to dereference it. */
5513 (restore_selected_frame
, &inf_status
->selected_frame_id
,
5514 "Unable to restore previously selected frame:\n",
5515 RETURN_MASK_ERROR
) == 0)
5516 /* Error in restoring the selected frame. Select the innermost
5518 select_frame (get_current_frame ());
5525 do_restore_inferior_status_cleanup (void *sts
)
5527 restore_inferior_status (sts
);
5531 make_cleanup_restore_inferior_status (struct inferior_status
*inf_status
)
5533 return make_cleanup (do_restore_inferior_status_cleanup
, inf_status
);
5537 discard_inferior_status (struct inferior_status
*inf_status
)
5539 /* See save_inferior_status for info on stop_bpstat. */
5540 bpstat_clear (&inf_status
->stop_bpstat
);
5545 inferior_has_forked (ptid_t pid
, ptid_t
*child_pid
)
5547 struct target_waitstatus last
;
5550 get_last_target_status (&last_ptid
, &last
);
5552 if (last
.kind
!= TARGET_WAITKIND_FORKED
)
5555 if (!ptid_equal (last_ptid
, pid
))
5558 *child_pid
= last
.value
.related_pid
;
5563 inferior_has_vforked (ptid_t pid
, ptid_t
*child_pid
)
5565 struct target_waitstatus last
;
5568 get_last_target_status (&last_ptid
, &last
);
5570 if (last
.kind
!= TARGET_WAITKIND_VFORKED
)
5573 if (!ptid_equal (last_ptid
, pid
))
5576 *child_pid
= last
.value
.related_pid
;
5581 inferior_has_execd (ptid_t pid
, char **execd_pathname
)
5583 struct target_waitstatus last
;
5586 get_last_target_status (&last_ptid
, &last
);
5588 if (last
.kind
!= TARGET_WAITKIND_EXECD
)
5591 if (!ptid_equal (last_ptid
, pid
))
5594 *execd_pathname
= xstrdup (last
.value
.execd_pathname
);
5598 /* Oft used ptids */
5600 ptid_t minus_one_ptid
;
5602 /* Create a ptid given the necessary PID, LWP, and TID components. */
5605 ptid_build (int pid
, long lwp
, long tid
)
5615 /* Create a ptid from just a pid. */
5618 pid_to_ptid (int pid
)
5620 return ptid_build (pid
, 0, 0);
5623 /* Fetch the pid (process id) component from a ptid. */
5626 ptid_get_pid (ptid_t ptid
)
5631 /* Fetch the lwp (lightweight process) component from a ptid. */
5634 ptid_get_lwp (ptid_t ptid
)
5639 /* Fetch the tid (thread id) component from a ptid. */
5642 ptid_get_tid (ptid_t ptid
)
5647 /* ptid_equal() is used to test equality of two ptids. */
5650 ptid_equal (ptid_t ptid1
, ptid_t ptid2
)
5652 return (ptid1
.pid
== ptid2
.pid
&& ptid1
.lwp
== ptid2
.lwp
5653 && ptid1
.tid
== ptid2
.tid
);
5656 /* Returns true if PTID represents a process. */
5659 ptid_is_pid (ptid_t ptid
)
5661 if (ptid_equal (minus_one_ptid
, ptid
))
5663 if (ptid_equal (null_ptid
, ptid
))
5666 return (ptid_get_lwp (ptid
) == 0 && ptid_get_tid (ptid
) == 0);
5669 /* restore_inferior_ptid() will be used by the cleanup machinery
5670 to restore the inferior_ptid value saved in a call to
5671 save_inferior_ptid(). */
5674 restore_inferior_ptid (void *arg
)
5676 ptid_t
*saved_ptid_ptr
= arg
;
5677 inferior_ptid
= *saved_ptid_ptr
;
5681 /* Save the value of inferior_ptid so that it may be restored by a
5682 later call to do_cleanups(). Returns the struct cleanup pointer
5683 needed for later doing the cleanup. */
5686 save_inferior_ptid (void)
5688 ptid_t
*saved_ptid_ptr
;
5690 saved_ptid_ptr
= xmalloc (sizeof (ptid_t
));
5691 *saved_ptid_ptr
= inferior_ptid
;
5692 return make_cleanup (restore_inferior_ptid
, saved_ptid_ptr
);
5696 /* User interface for reverse debugging:
5697 Set exec-direction / show exec-direction commands
5698 (returns error unless target implements to_set_exec_direction method). */
5700 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
5701 static const char exec_forward
[] = "forward";
5702 static const char exec_reverse
[] = "reverse";
5703 static const char *exec_direction
= exec_forward
;
5704 static const char *exec_direction_names
[] = {
5711 set_exec_direction_func (char *args
, int from_tty
,
5712 struct cmd_list_element
*cmd
)
5714 if (target_can_execute_reverse
)
5716 if (!strcmp (exec_direction
, exec_forward
))
5717 execution_direction
= EXEC_FORWARD
;
5718 else if (!strcmp (exec_direction
, exec_reverse
))
5719 execution_direction
= EXEC_REVERSE
;
5724 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
5725 struct cmd_list_element
*cmd
, const char *value
)
5727 switch (execution_direction
) {
5729 fprintf_filtered (out
, _("Forward.\n"));
5732 fprintf_filtered (out
, _("Reverse.\n"));
5736 fprintf_filtered (out
,
5737 _("Forward (target `%s' does not support exec-direction).\n"),
5743 /* User interface for non-stop mode. */
5746 static int non_stop_1
= 0;
5749 set_non_stop (char *args
, int from_tty
,
5750 struct cmd_list_element
*c
)
5752 if (target_has_execution
)
5754 non_stop_1
= non_stop
;
5755 error (_("Cannot change this setting while the inferior is running."));
5758 non_stop
= non_stop_1
;
5762 show_non_stop (struct ui_file
*file
, int from_tty
,
5763 struct cmd_list_element
*c
, const char *value
)
5765 fprintf_filtered (file
,
5766 _("Controlling the inferior in non-stop mode is %s.\n"),
5771 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
5772 struct cmd_list_element
*c
, const char *value
)
5774 fprintf_filtered (file
, _("\
5775 Resuming the execution of threads of all processes is %s.\n"), value
);
5779 _initialize_infrun (void)
5783 struct cmd_list_element
*c
;
5785 add_info ("signals", signals_info
, _("\
5786 What debugger does when program gets various signals.\n\
5787 Specify a signal as argument to print info on that signal only."));
5788 add_info_alias ("handle", "signals", 0);
5790 add_com ("handle", class_run
, handle_command
, _("\
5791 Specify how to handle a signal.\n\
5792 Args are signals and actions to apply to those signals.\n\
5793 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
5794 from 1-15 are allowed for compatibility with old versions of GDB.\n\
5795 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
5796 The special arg \"all\" is recognized to mean all signals except those\n\
5797 used by the debugger, typically SIGTRAP and SIGINT.\n\
5798 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
5799 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
5800 Stop means reenter debugger if this signal happens (implies print).\n\
5801 Print means print a message if this signal happens.\n\
5802 Pass means let program see this signal; otherwise program doesn't know.\n\
5803 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
5804 Pass and Stop may be combined."));
5807 add_com ("lz", class_info
, signals_info
, _("\
5808 What debugger does when program gets various signals.\n\
5809 Specify a signal as argument to print info on that signal only."));
5810 add_com ("z", class_run
, xdb_handle_command
, _("\
5811 Specify how to handle a signal.\n\
5812 Args are signals and actions to apply to those signals.\n\
5813 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
5814 from 1-15 are allowed for compatibility with old versions of GDB.\n\
5815 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
5816 The special arg \"all\" is recognized to mean all signals except those\n\
5817 used by the debugger, typically SIGTRAP and SIGINT.\n\
5818 Recognized actions include \"s\" (toggles between stop and nostop), \n\
5819 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
5820 nopass), \"Q\" (noprint)\n\
5821 Stop means reenter debugger if this signal happens (implies print).\n\
5822 Print means print a message if this signal happens.\n\
5823 Pass means let program see this signal; otherwise program doesn't know.\n\
5824 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
5825 Pass and Stop may be combined."));
5829 stop_command
= add_cmd ("stop", class_obscure
,
5830 not_just_help_class_command
, _("\
5831 There is no `stop' command, but you can set a hook on `stop'.\n\
5832 This allows you to set a list of commands to be run each time execution\n\
5833 of the program stops."), &cmdlist
);
5835 add_setshow_zinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
5836 Set inferior debugging."), _("\
5837 Show inferior debugging."), _("\
5838 When non-zero, inferior specific debugging is enabled."),
5841 &setdebuglist
, &showdebuglist
);
5843 add_setshow_boolean_cmd ("displaced", class_maintenance
, &debug_displaced
, _("\
5844 Set displaced stepping debugging."), _("\
5845 Show displaced stepping debugging."), _("\
5846 When non-zero, displaced stepping specific debugging is enabled."),
5848 show_debug_displaced
,
5849 &setdebuglist
, &showdebuglist
);
5851 add_setshow_boolean_cmd ("non-stop", no_class
,
5853 Set whether gdb controls the inferior in non-stop mode."), _("\
5854 Show whether gdb controls the inferior in non-stop mode."), _("\
5855 When debugging a multi-threaded program and this setting is\n\
5856 off (the default, also called all-stop mode), when one thread stops\n\
5857 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
5858 all other threads in the program while you interact with the thread of\n\
5859 interest. When you continue or step a thread, you can allow the other\n\
5860 threads to run, or have them remain stopped, but while you inspect any\n\
5861 thread's state, all threads stop.\n\
5863 In non-stop mode, when one thread stops, other threads can continue\n\
5864 to run freely. You'll be able to step each thread independently,\n\
5865 leave it stopped or free to run as needed."),
5871 numsigs
= (int) TARGET_SIGNAL_LAST
;
5872 signal_stop
= (unsigned char *) xmalloc (sizeof (signal_stop
[0]) * numsigs
);
5873 signal_print
= (unsigned char *)
5874 xmalloc (sizeof (signal_print
[0]) * numsigs
);
5875 signal_program
= (unsigned char *)
5876 xmalloc (sizeof (signal_program
[0]) * numsigs
);
5877 for (i
= 0; i
< numsigs
; i
++)
5880 signal_print
[i
] = 1;
5881 signal_program
[i
] = 1;
5884 /* Signals caused by debugger's own actions
5885 should not be given to the program afterwards. */
5886 signal_program
[TARGET_SIGNAL_TRAP
] = 0;
5887 signal_program
[TARGET_SIGNAL_INT
] = 0;
5889 /* Signals that are not errors should not normally enter the debugger. */
5890 signal_stop
[TARGET_SIGNAL_ALRM
] = 0;
5891 signal_print
[TARGET_SIGNAL_ALRM
] = 0;
5892 signal_stop
[TARGET_SIGNAL_VTALRM
] = 0;
5893 signal_print
[TARGET_SIGNAL_VTALRM
] = 0;
5894 signal_stop
[TARGET_SIGNAL_PROF
] = 0;
5895 signal_print
[TARGET_SIGNAL_PROF
] = 0;
5896 signal_stop
[TARGET_SIGNAL_CHLD
] = 0;
5897 signal_print
[TARGET_SIGNAL_CHLD
] = 0;
5898 signal_stop
[TARGET_SIGNAL_IO
] = 0;
5899 signal_print
[TARGET_SIGNAL_IO
] = 0;
5900 signal_stop
[TARGET_SIGNAL_POLL
] = 0;
5901 signal_print
[TARGET_SIGNAL_POLL
] = 0;
5902 signal_stop
[TARGET_SIGNAL_URG
] = 0;
5903 signal_print
[TARGET_SIGNAL_URG
] = 0;
5904 signal_stop
[TARGET_SIGNAL_WINCH
] = 0;
5905 signal_print
[TARGET_SIGNAL_WINCH
] = 0;
5907 /* These signals are used internally by user-level thread
5908 implementations. (See signal(5) on Solaris.) Like the above
5909 signals, a healthy program receives and handles them as part of
5910 its normal operation. */
5911 signal_stop
[TARGET_SIGNAL_LWP
] = 0;
5912 signal_print
[TARGET_SIGNAL_LWP
] = 0;
5913 signal_stop
[TARGET_SIGNAL_WAITING
] = 0;
5914 signal_print
[TARGET_SIGNAL_WAITING
] = 0;
5915 signal_stop
[TARGET_SIGNAL_CANCEL
] = 0;
5916 signal_print
[TARGET_SIGNAL_CANCEL
] = 0;
5918 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
5919 &stop_on_solib_events
, _("\
5920 Set stopping for shared library events."), _("\
5921 Show stopping for shared library events."), _("\
5922 If nonzero, gdb will give control to the user when the dynamic linker\n\
5923 notifies gdb of shared library events. The most common event of interest\n\
5924 to the user would be loading/unloading of a new library."),
5926 show_stop_on_solib_events
,
5927 &setlist
, &showlist
);
5929 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
5930 follow_fork_mode_kind_names
,
5931 &follow_fork_mode_string
, _("\
5932 Set debugger response to a program call of fork or vfork."), _("\
5933 Show debugger response to a program call of fork or vfork."), _("\
5934 A fork or vfork creates a new process. follow-fork-mode can be:\n\
5935 parent - the original process is debugged after a fork\n\
5936 child - the new process is debugged after a fork\n\
5937 The unfollowed process will continue to run.\n\
5938 By default, the debugger will follow the parent process."),
5940 show_follow_fork_mode_string
,
5941 &setlist
, &showlist
);
5943 add_setshow_enum_cmd ("scheduler-locking", class_run
,
5944 scheduler_enums
, &scheduler_mode
, _("\
5945 Set mode for locking scheduler during execution."), _("\
5946 Show mode for locking scheduler during execution."), _("\
5947 off == no locking (threads may preempt at any time)\n\
5948 on == full locking (no thread except the current thread may run)\n\
5949 step == scheduler locked during every single-step operation.\n\
5950 In this mode, no other thread may run during a step command.\n\
5951 Other threads may run while stepping over a function call ('next')."),
5952 set_schedlock_func
, /* traps on target vector */
5953 show_scheduler_mode
,
5954 &setlist
, &showlist
);
5956 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
5957 Set mode for resuming threads of all processes."), _("\
5958 Show mode for resuming threads of all processes."), _("\
5959 When on, execution commands (such as 'continue' or 'next') resume all\n\
5960 threads of all processes. When off (which is the default), execution\n\
5961 commands only resume the threads of the current process. The set of\n\
5962 threads that are resumed is further refined by the scheduler-locking\n\
5963 mode (see help set scheduler-locking)."),
5965 show_schedule_multiple
,
5966 &setlist
, &showlist
);
5968 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
5969 Set mode of the step operation."), _("\
5970 Show mode of the step operation."), _("\
5971 When set, doing a step over a function without debug line information\n\
5972 will stop at the first instruction of that function. Otherwise, the\n\
5973 function is skipped and the step command stops at a different source line."),
5975 show_step_stop_if_no_debug
,
5976 &setlist
, &showlist
);
5978 add_setshow_enum_cmd ("displaced-stepping", class_run
,
5979 can_use_displaced_stepping_enum
,
5980 &can_use_displaced_stepping
, _("\
5981 Set debugger's willingness to use displaced stepping."), _("\
5982 Show debugger's willingness to use displaced stepping."), _("\
5983 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
5984 supported by the target architecture. If off, gdb will not use displaced\n\
5985 stepping to step over breakpoints, even if such is supported by the target\n\
5986 architecture. If auto (which is the default), gdb will use displaced stepping\n\
5987 if the target architecture supports it and non-stop mode is active, but will not\n\
5988 use it in all-stop mode (see help set non-stop)."),
5990 show_can_use_displaced_stepping
,
5991 &setlist
, &showlist
);
5993 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
5994 &exec_direction
, _("Set direction of execution.\n\
5995 Options are 'forward' or 'reverse'."),
5996 _("Show direction of execution (forward/reverse)."),
5997 _("Tells gdb whether to execute forward or backward."),
5998 set_exec_direction_func
, show_exec_direction_func
,
5999 &setlist
, &showlist
);
6001 /* ptid initializations */
6002 null_ptid
= ptid_build (0, 0, 0);
6003 minus_one_ptid
= ptid_build (-1, 0, 0);
6004 inferior_ptid
= null_ptid
;
6005 target_last_wait_ptid
= minus_one_ptid
;
6006 displaced_step_ptid
= null_ptid
;
6008 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed
);
6009 observer_attach_thread_stop_requested (infrun_thread_stop_requested
);
6010 observer_attach_thread_exit (infrun_thread_thread_exit
);
6012 /* Explicitly create without lookup, since that tries to create a
6013 value with a void typed value, and when we get here, gdbarch
6014 isn't initialized yet. At this point, we're quite sure there
6015 isn't another convenience variable of the same name. */
6016 create_internalvar_type_lazy ("_siginfo", siginfo_make_value
);