1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2013 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "gdb_string.h"
27 #include "exceptions.h"
28 #include "breakpoint.h"
32 #include "cli/cli-script.h"
34 #include "gdbthread.h"
46 #include "dictionary.h"
48 #include "gdb_assert.h"
49 #include "mi/mi-common.h"
50 #include "event-top.h"
52 #include "record-full.h"
53 #include "inline-frame.h"
55 #include "tracepoint.h"
56 #include "continuations.h"
61 #include "completer.h"
62 #include "target-descriptions.h"
64 /* Prototypes for local functions */
66 static void signals_info (char *, int);
68 static void handle_command (char *, int);
70 static void sig_print_info (enum gdb_signal);
72 static void sig_print_header (void);
74 static void resume_cleanups (void *);
76 static int hook_stop_stub (void *);
78 static int restore_selected_frame (void *);
80 static int follow_fork (void);
82 static void set_schedlock_func (char *args, int from_tty,
83 struct cmd_list_element *c);
85 static int currently_stepping (struct thread_info *tp);
87 static int currently_stepping_or_nexting_callback (struct thread_info *tp,
90 static void xdb_handle_command (char *args, int from_tty);
92 static int prepare_to_proceed (int);
94 static void print_exited_reason (int exitstatus);
96 static void print_signal_exited_reason (enum gdb_signal siggnal);
98 static void print_no_history_reason (void);
100 static void print_signal_received_reason (enum gdb_signal siggnal);
102 static void print_end_stepping_range_reason (void);
104 void _initialize_infrun (void);
106 void nullify_last_target_wait_ptid (void);
108 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
110 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
112 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
114 /* When set, stop the 'step' command if we enter a function which has
115 no line number information. The normal behavior is that we step
116 over such function. */
117 int step_stop_if_no_debug = 0;
119 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
120 struct cmd_list_element *c, const char *value)
122 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
125 /* In asynchronous mode, but simulating synchronous execution. */
127 int sync_execution = 0;
129 /* wait_for_inferior and normal_stop use this to notify the user
130 when the inferior stopped in a different thread than it had been
133 static ptid_t previous_inferior_ptid;
135 /* If set (default for legacy reasons), when following a fork, GDB
136 will detach from one of the fork branches, child or parent.
137 Exactly which branch is detached depends on 'set follow-fork-mode'
140 static int detach_fork = 1;
142 int debug_displaced = 0;
144 show_debug_displaced (struct ui_file *file, int from_tty,
145 struct cmd_list_element *c, const char *value)
147 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
150 unsigned int debug_infrun = 0;
152 show_debug_infrun (struct ui_file *file, int from_tty,
153 struct cmd_list_element *c, const char *value)
155 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
159 /* Support for disabling address space randomization. */
161 int disable_randomization = 1;
164 show_disable_randomization (struct ui_file *file, int from_tty,
165 struct cmd_list_element *c, const char *value)
167 if (target_supports_disable_randomization ())
168 fprintf_filtered (file,
169 _("Disabling randomization of debuggee's "
170 "virtual address space is %s.\n"),
173 fputs_filtered (_("Disabling randomization of debuggee's "
174 "virtual address space is unsupported on\n"
175 "this platform.\n"), file);
179 set_disable_randomization (char *args, int from_tty,
180 struct cmd_list_element *c)
182 if (!target_supports_disable_randomization ())
183 error (_("Disabling randomization of debuggee's "
184 "virtual address space is unsupported on\n"
188 /* User interface for non-stop mode. */
191 static int non_stop_1 = 0;
194 set_non_stop (char *args, int from_tty,
195 struct cmd_list_element *c)
197 if (target_has_execution)
199 non_stop_1 = non_stop;
200 error (_("Cannot change this setting while the inferior is running."));
203 non_stop = non_stop_1;
207 show_non_stop (struct ui_file *file, int from_tty,
208 struct cmd_list_element *c, const char *value)
210 fprintf_filtered (file,
211 _("Controlling the inferior in non-stop mode is %s.\n"),
215 /* "Observer mode" is somewhat like a more extreme version of
216 non-stop, in which all GDB operations that might affect the
217 target's execution have been disabled. */
219 int observer_mode = 0;
220 static int observer_mode_1 = 0;
223 set_observer_mode (char *args, int from_tty,
224 struct cmd_list_element *c)
226 if (target_has_execution)
228 observer_mode_1 = observer_mode;
229 error (_("Cannot change this setting while the inferior is running."));
232 observer_mode = observer_mode_1;
234 may_write_registers = !observer_mode;
235 may_write_memory = !observer_mode;
236 may_insert_breakpoints = !observer_mode;
237 may_insert_tracepoints = !observer_mode;
238 /* We can insert fast tracepoints in or out of observer mode,
239 but enable them if we're going into this mode. */
241 may_insert_fast_tracepoints = 1;
242 may_stop = !observer_mode;
243 update_target_permissions ();
245 /* Going *into* observer mode we must force non-stop, then
246 going out we leave it that way. */
249 target_async_permitted = 1;
250 pagination_enabled = 0;
251 non_stop = non_stop_1 = 1;
255 printf_filtered (_("Observer mode is now %s.\n"),
256 (observer_mode ? "on" : "off"));
260 show_observer_mode (struct ui_file *file, int from_tty,
261 struct cmd_list_element *c, const char *value)
263 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
266 /* This updates the value of observer mode based on changes in
267 permissions. Note that we are deliberately ignoring the values of
268 may-write-registers and may-write-memory, since the user may have
269 reason to enable these during a session, for instance to turn on a
270 debugging-related global. */
273 update_observer_mode (void)
277 newval = (!may_insert_breakpoints
278 && !may_insert_tracepoints
279 && may_insert_fast_tracepoints
283 /* Let the user know if things change. */
284 if (newval != observer_mode)
285 printf_filtered (_("Observer mode is now %s.\n"),
286 (newval ? "on" : "off"));
288 observer_mode = observer_mode_1 = newval;
291 /* Tables of how to react to signals; the user sets them. */
293 static unsigned char *signal_stop;
294 static unsigned char *signal_print;
295 static unsigned char *signal_program;
297 /* Table of signals that are registered with "catch signal". A
298 non-zero entry indicates that the signal is caught by some "catch
299 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
301 static unsigned char *signal_catch;
303 /* Table of signals that the target may silently handle.
304 This is automatically determined from the flags above,
305 and simply cached here. */
306 static unsigned char *signal_pass;
308 #define SET_SIGS(nsigs,sigs,flags) \
310 int signum = (nsigs); \
311 while (signum-- > 0) \
312 if ((sigs)[signum]) \
313 (flags)[signum] = 1; \
316 #define UNSET_SIGS(nsigs,sigs,flags) \
318 int signum = (nsigs); \
319 while (signum-- > 0) \
320 if ((sigs)[signum]) \
321 (flags)[signum] = 0; \
324 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
325 this function is to avoid exporting `signal_program'. */
328 update_signals_program_target (void)
330 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
333 /* Value to pass to target_resume() to cause all threads to resume. */
335 #define RESUME_ALL minus_one_ptid
337 /* Command list pointer for the "stop" placeholder. */
339 static struct cmd_list_element *stop_command;
341 /* Function inferior was in as of last step command. */
343 static struct symbol *step_start_function;
345 /* Nonzero if we want to give control to the user when we're notified
346 of shared library events by the dynamic linker. */
347 int stop_on_solib_events;
349 /* Enable or disable optional shared library event breakpoints
350 as appropriate when the above flag is changed. */
353 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
355 update_solib_breakpoints ();
359 show_stop_on_solib_events (struct ui_file *file, int from_tty,
360 struct cmd_list_element *c, const char *value)
362 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
366 /* Nonzero means expecting a trace trap
367 and should stop the inferior and return silently when it happens. */
371 /* Save register contents here when executing a "finish" command or are
372 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
373 Thus this contains the return value from the called function (assuming
374 values are returned in a register). */
376 struct regcache *stop_registers;
378 /* Nonzero after stop if current stack frame should be printed. */
380 static int stop_print_frame;
382 /* This is a cached copy of the pid/waitstatus of the last event
383 returned by target_wait()/deprecated_target_wait_hook(). This
384 information is returned by get_last_target_status(). */
385 static ptid_t target_last_wait_ptid;
386 static struct target_waitstatus target_last_waitstatus;
388 static void context_switch (ptid_t ptid);
390 void init_thread_stepping_state (struct thread_info *tss);
392 static void init_infwait_state (void);
394 static const char follow_fork_mode_child[] = "child";
395 static const char follow_fork_mode_parent[] = "parent";
397 static const char *const follow_fork_mode_kind_names[] = {
398 follow_fork_mode_child,
399 follow_fork_mode_parent,
403 static const char *follow_fork_mode_string = follow_fork_mode_parent;
405 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
406 struct cmd_list_element *c, const char *value)
408 fprintf_filtered (file,
409 _("Debugger response to a program "
410 "call of fork or vfork is \"%s\".\n"),
415 /* Tell the target to follow the fork we're stopped at. Returns true
416 if the inferior should be resumed; false, if the target for some
417 reason decided it's best not to resume. */
422 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
423 int should_resume = 1;
424 struct thread_info *tp;
426 /* Copy user stepping state to the new inferior thread. FIXME: the
427 followed fork child thread should have a copy of most of the
428 parent thread structure's run control related fields, not just these.
429 Initialized to avoid "may be used uninitialized" warnings from gcc. */
430 struct breakpoint *step_resume_breakpoint = NULL;
431 struct breakpoint *exception_resume_breakpoint = NULL;
432 CORE_ADDR step_range_start = 0;
433 CORE_ADDR step_range_end = 0;
434 struct frame_id step_frame_id = { 0 };
439 struct target_waitstatus wait_status;
441 /* Get the last target status returned by target_wait(). */
442 get_last_target_status (&wait_ptid, &wait_status);
444 /* If not stopped at a fork event, then there's nothing else to
446 if (wait_status.kind != TARGET_WAITKIND_FORKED
447 && wait_status.kind != TARGET_WAITKIND_VFORKED)
450 /* Check if we switched over from WAIT_PTID, since the event was
452 if (!ptid_equal (wait_ptid, minus_one_ptid)
453 && !ptid_equal (inferior_ptid, wait_ptid))
455 /* We did. Switch back to WAIT_PTID thread, to tell the
456 target to follow it (in either direction). We'll
457 afterwards refuse to resume, and inform the user what
459 switch_to_thread (wait_ptid);
464 tp = inferior_thread ();
466 /* If there were any forks/vforks that were caught and are now to be
467 followed, then do so now. */
468 switch (tp->pending_follow.kind)
470 case TARGET_WAITKIND_FORKED:
471 case TARGET_WAITKIND_VFORKED:
473 ptid_t parent, child;
475 /* If the user did a next/step, etc, over a fork call,
476 preserve the stepping state in the fork child. */
477 if (follow_child && should_resume)
479 step_resume_breakpoint = clone_momentary_breakpoint
480 (tp->control.step_resume_breakpoint);
481 step_range_start = tp->control.step_range_start;
482 step_range_end = tp->control.step_range_end;
483 step_frame_id = tp->control.step_frame_id;
484 exception_resume_breakpoint
485 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
487 /* For now, delete the parent's sr breakpoint, otherwise,
488 parent/child sr breakpoints are considered duplicates,
489 and the child version will not be installed. Remove
490 this when the breakpoints module becomes aware of
491 inferiors and address spaces. */
492 delete_step_resume_breakpoint (tp);
493 tp->control.step_range_start = 0;
494 tp->control.step_range_end = 0;
495 tp->control.step_frame_id = null_frame_id;
496 delete_exception_resume_breakpoint (tp);
499 parent = inferior_ptid;
500 child = tp->pending_follow.value.related_pid;
502 /* Tell the target to do whatever is necessary to follow
503 either parent or child. */
504 if (target_follow_fork (follow_child, detach_fork))
506 /* Target refused to follow, or there's some other reason
507 we shouldn't resume. */
512 /* This pending follow fork event is now handled, one way
513 or another. The previous selected thread may be gone
514 from the lists by now, but if it is still around, need
515 to clear the pending follow request. */
516 tp = find_thread_ptid (parent);
518 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
520 /* This makes sure we don't try to apply the "Switched
521 over from WAIT_PID" logic above. */
522 nullify_last_target_wait_ptid ();
524 /* If we followed the child, switch to it... */
527 switch_to_thread (child);
529 /* ... and preserve the stepping state, in case the
530 user was stepping over the fork call. */
533 tp = inferior_thread ();
534 tp->control.step_resume_breakpoint
535 = step_resume_breakpoint;
536 tp->control.step_range_start = step_range_start;
537 tp->control.step_range_end = step_range_end;
538 tp->control.step_frame_id = step_frame_id;
539 tp->control.exception_resume_breakpoint
540 = exception_resume_breakpoint;
544 /* If we get here, it was because we're trying to
545 resume from a fork catchpoint, but, the user
546 has switched threads away from the thread that
547 forked. In that case, the resume command
548 issued is most likely not applicable to the
549 child, so just warn, and refuse to resume. */
550 warning (_("Not resuming: switched threads "
551 "before following fork child.\n"));
554 /* Reset breakpoints in the child as appropriate. */
555 follow_inferior_reset_breakpoints ();
558 switch_to_thread (parent);
562 case TARGET_WAITKIND_SPURIOUS:
563 /* Nothing to follow. */
566 internal_error (__FILE__, __LINE__,
567 "Unexpected pending_follow.kind %d\n",
568 tp->pending_follow.kind);
572 return should_resume;
576 follow_inferior_reset_breakpoints (void)
578 struct thread_info *tp = inferior_thread ();
580 /* Was there a step_resume breakpoint? (There was if the user
581 did a "next" at the fork() call.) If so, explicitly reset its
584 step_resumes are a form of bp that are made to be per-thread.
585 Since we created the step_resume bp when the parent process
586 was being debugged, and now are switching to the child process,
587 from the breakpoint package's viewpoint, that's a switch of
588 "threads". We must update the bp's notion of which thread
589 it is for, or it'll be ignored when it triggers. */
591 if (tp->control.step_resume_breakpoint)
592 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
594 if (tp->control.exception_resume_breakpoint)
595 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
597 /* Reinsert all breakpoints in the child. The user may have set
598 breakpoints after catching the fork, in which case those
599 were never set in the child, but only in the parent. This makes
600 sure the inserted breakpoints match the breakpoint list. */
602 breakpoint_re_set ();
603 insert_breakpoints ();
606 /* The child has exited or execed: resume threads of the parent the
607 user wanted to be executing. */
610 proceed_after_vfork_done (struct thread_info *thread,
613 int pid = * (int *) arg;
615 if (ptid_get_pid (thread->ptid) == pid
616 && is_running (thread->ptid)
617 && !is_executing (thread->ptid)
618 && !thread->stop_requested
619 && thread->suspend.stop_signal == GDB_SIGNAL_0)
622 fprintf_unfiltered (gdb_stdlog,
623 "infrun: resuming vfork parent thread %s\n",
624 target_pid_to_str (thread->ptid));
626 switch_to_thread (thread->ptid);
627 clear_proceed_status ();
628 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0);
634 /* Called whenever we notice an exec or exit event, to handle
635 detaching or resuming a vfork parent. */
638 handle_vfork_child_exec_or_exit (int exec)
640 struct inferior *inf = current_inferior ();
642 if (inf->vfork_parent)
644 int resume_parent = -1;
646 /* This exec or exit marks the end of the shared memory region
647 between the parent and the child. If the user wanted to
648 detach from the parent, now is the time. */
650 if (inf->vfork_parent->pending_detach)
652 struct thread_info *tp;
653 struct cleanup *old_chain;
654 struct program_space *pspace;
655 struct address_space *aspace;
657 /* follow-fork child, detach-on-fork on. */
659 inf->vfork_parent->pending_detach = 0;
663 /* If we're handling a child exit, then inferior_ptid
664 points at the inferior's pid, not to a thread. */
665 old_chain = save_inferior_ptid ();
666 save_current_program_space ();
667 save_current_inferior ();
670 old_chain = save_current_space_and_thread ();
672 /* We're letting loose of the parent. */
673 tp = any_live_thread_of_process (inf->vfork_parent->pid);
674 switch_to_thread (tp->ptid);
676 /* We're about to detach from the parent, which implicitly
677 removes breakpoints from its address space. There's a
678 catch here: we want to reuse the spaces for the child,
679 but, parent/child are still sharing the pspace at this
680 point, although the exec in reality makes the kernel give
681 the child a fresh set of new pages. The problem here is
682 that the breakpoints module being unaware of this, would
683 likely chose the child process to write to the parent
684 address space. Swapping the child temporarily away from
685 the spaces has the desired effect. Yes, this is "sort
688 pspace = inf->pspace;
689 aspace = inf->aspace;
693 if (debug_infrun || info_verbose)
695 target_terminal_ours ();
698 fprintf_filtered (gdb_stdlog,
699 "Detaching vfork parent process "
700 "%d after child exec.\n",
701 inf->vfork_parent->pid);
703 fprintf_filtered (gdb_stdlog,
704 "Detaching vfork parent process "
705 "%d after child exit.\n",
706 inf->vfork_parent->pid);
709 target_detach (NULL, 0);
712 inf->pspace = pspace;
713 inf->aspace = aspace;
715 do_cleanups (old_chain);
719 /* We're staying attached to the parent, so, really give the
720 child a new address space. */
721 inf->pspace = add_program_space (maybe_new_address_space ());
722 inf->aspace = inf->pspace->aspace;
724 set_current_program_space (inf->pspace);
726 resume_parent = inf->vfork_parent->pid;
728 /* Break the bonds. */
729 inf->vfork_parent->vfork_child = NULL;
733 struct cleanup *old_chain;
734 struct program_space *pspace;
736 /* If this is a vfork child exiting, then the pspace and
737 aspaces were shared with the parent. Since we're
738 reporting the process exit, we'll be mourning all that is
739 found in the address space, and switching to null_ptid,
740 preparing to start a new inferior. But, since we don't
741 want to clobber the parent's address/program spaces, we
742 go ahead and create a new one for this exiting
745 /* Switch to null_ptid, so that clone_program_space doesn't want
746 to read the selected frame of a dead process. */
747 old_chain = save_inferior_ptid ();
748 inferior_ptid = null_ptid;
750 /* This inferior is dead, so avoid giving the breakpoints
751 module the option to write through to it (cloning a
752 program space resets breakpoints). */
755 pspace = add_program_space (maybe_new_address_space ());
756 set_current_program_space (pspace);
758 inf->symfile_flags = SYMFILE_NO_READ;
759 clone_program_space (pspace, inf->vfork_parent->pspace);
760 inf->pspace = pspace;
761 inf->aspace = pspace->aspace;
763 /* Put back inferior_ptid. We'll continue mourning this
765 do_cleanups (old_chain);
767 resume_parent = inf->vfork_parent->pid;
768 /* Break the bonds. */
769 inf->vfork_parent->vfork_child = NULL;
772 inf->vfork_parent = NULL;
774 gdb_assert (current_program_space == inf->pspace);
776 if (non_stop && resume_parent != -1)
778 /* If the user wanted the parent to be running, let it go
780 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
783 fprintf_unfiltered (gdb_stdlog,
784 "infrun: resuming vfork parent process %d\n",
787 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
789 do_cleanups (old_chain);
794 /* Enum strings for "set|show follow-exec-mode". */
796 static const char follow_exec_mode_new[] = "new";
797 static const char follow_exec_mode_same[] = "same";
798 static const char *const follow_exec_mode_names[] =
800 follow_exec_mode_new,
801 follow_exec_mode_same,
805 static const char *follow_exec_mode_string = follow_exec_mode_same;
807 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
808 struct cmd_list_element *c, const char *value)
810 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
813 /* EXECD_PATHNAME is assumed to be non-NULL. */
816 follow_exec (ptid_t pid, char *execd_pathname)
818 struct thread_info *th = inferior_thread ();
819 struct inferior *inf = current_inferior ();
821 /* This is an exec event that we actually wish to pay attention to.
822 Refresh our symbol table to the newly exec'd program, remove any
825 If there are breakpoints, they aren't really inserted now,
826 since the exec() transformed our inferior into a fresh set
829 We want to preserve symbolic breakpoints on the list, since
830 we have hopes that they can be reset after the new a.out's
831 symbol table is read.
833 However, any "raw" breakpoints must be removed from the list
834 (e.g., the solib bp's), since their address is probably invalid
837 And, we DON'T want to call delete_breakpoints() here, since
838 that may write the bp's "shadow contents" (the instruction
839 value that was overwritten witha TRAP instruction). Since
840 we now have a new a.out, those shadow contents aren't valid. */
842 mark_breakpoints_out ();
844 update_breakpoints_after_exec ();
846 /* If there was one, it's gone now. We cannot truly step-to-next
847 statement through an exec(). */
848 th->control.step_resume_breakpoint = NULL;
849 th->control.exception_resume_breakpoint = NULL;
850 th->control.step_range_start = 0;
851 th->control.step_range_end = 0;
853 /* The target reports the exec event to the main thread, even if
854 some other thread does the exec, and even if the main thread was
855 already stopped --- if debugging in non-stop mode, it's possible
856 the user had the main thread held stopped in the previous image
857 --- release it now. This is the same behavior as step-over-exec
858 with scheduler-locking on in all-stop mode. */
859 th->stop_requested = 0;
861 /* What is this a.out's name? */
862 printf_unfiltered (_("%s is executing new program: %s\n"),
863 target_pid_to_str (inferior_ptid),
866 /* We've followed the inferior through an exec. Therefore, the
867 inferior has essentially been killed & reborn. */
869 gdb_flush (gdb_stdout);
871 breakpoint_init_inferior (inf_execd);
873 if (gdb_sysroot && *gdb_sysroot)
875 char *name = alloca (strlen (gdb_sysroot)
876 + strlen (execd_pathname)
879 strcpy (name, gdb_sysroot);
880 strcat (name, execd_pathname);
881 execd_pathname = name;
884 /* Reset the shared library package. This ensures that we get a
885 shlib event when the child reaches "_start", at which point the
886 dld will have had a chance to initialize the child. */
887 /* Also, loading a symbol file below may trigger symbol lookups, and
888 we don't want those to be satisfied by the libraries of the
889 previous incarnation of this process. */
890 no_shared_libraries (NULL, 0);
892 if (follow_exec_mode_string == follow_exec_mode_new)
894 struct program_space *pspace;
896 /* The user wants to keep the old inferior and program spaces
897 around. Create a new fresh one, and switch to it. */
899 inf = add_inferior (current_inferior ()->pid);
900 pspace = add_program_space (maybe_new_address_space ());
901 inf->pspace = pspace;
902 inf->aspace = pspace->aspace;
904 exit_inferior_num_silent (current_inferior ()->num);
906 set_current_inferior (inf);
907 set_current_program_space (pspace);
911 /* The old description may no longer be fit for the new image.
912 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
913 old description; we'll read a new one below. No need to do
914 this on "follow-exec-mode new", as the old inferior stays
915 around (its description is later cleared/refetched on
917 target_clear_description ();
920 gdb_assert (current_program_space == inf->pspace);
922 /* That a.out is now the one to use. */
923 exec_file_attach (execd_pathname, 0);
925 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
926 (Position Independent Executable) main symbol file will get applied by
927 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
928 the breakpoints with the zero displacement. */
930 symbol_file_add (execd_pathname,
932 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
935 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
936 set_initial_language ();
938 /* If the target can specify a description, read it. Must do this
939 after flipping to the new executable (because the target supplied
940 description must be compatible with the executable's
941 architecture, and the old executable may e.g., be 32-bit, while
942 the new one 64-bit), and before anything involving memory or
944 target_find_description ();
946 solib_create_inferior_hook (0);
948 jit_inferior_created_hook ();
950 breakpoint_re_set ();
952 /* Reinsert all breakpoints. (Those which were symbolic have
953 been reset to the proper address in the new a.out, thanks
954 to symbol_file_command...). */
955 insert_breakpoints ();
957 /* The next resume of this inferior should bring it to the shlib
958 startup breakpoints. (If the user had also set bp's on
959 "main" from the old (parent) process, then they'll auto-
960 matically get reset there in the new process.). */
963 /* Non-zero if we just simulating a single-step. This is needed
964 because we cannot remove the breakpoints in the inferior process
965 until after the `wait' in `wait_for_inferior'. */
966 static int singlestep_breakpoints_inserted_p = 0;
968 /* The thread we inserted single-step breakpoints for. */
969 static ptid_t singlestep_ptid;
971 /* PC when we started this single-step. */
972 static CORE_ADDR singlestep_pc;
974 /* If another thread hit the singlestep breakpoint, we save the original
975 thread here so that we can resume single-stepping it later. */
976 static ptid_t saved_singlestep_ptid;
977 static int stepping_past_singlestep_breakpoint;
979 /* If not equal to null_ptid, this means that after stepping over breakpoint
980 is finished, we need to switch to deferred_step_ptid, and step it.
982 The use case is when one thread has hit a breakpoint, and then the user
983 has switched to another thread and issued 'step'. We need to step over
984 breakpoint in the thread which hit the breakpoint, but then continue
985 stepping the thread user has selected. */
986 static ptid_t deferred_step_ptid;
988 /* Displaced stepping. */
990 /* In non-stop debugging mode, we must take special care to manage
991 breakpoints properly; in particular, the traditional strategy for
992 stepping a thread past a breakpoint it has hit is unsuitable.
993 'Displaced stepping' is a tactic for stepping one thread past a
994 breakpoint it has hit while ensuring that other threads running
995 concurrently will hit the breakpoint as they should.
997 The traditional way to step a thread T off a breakpoint in a
998 multi-threaded program in all-stop mode is as follows:
1000 a0) Initially, all threads are stopped, and breakpoints are not
1002 a1) We single-step T, leaving breakpoints uninserted.
1003 a2) We insert breakpoints, and resume all threads.
1005 In non-stop debugging, however, this strategy is unsuitable: we
1006 don't want to have to stop all threads in the system in order to
1007 continue or step T past a breakpoint. Instead, we use displaced
1010 n0) Initially, T is stopped, other threads are running, and
1011 breakpoints are inserted.
1012 n1) We copy the instruction "under" the breakpoint to a separate
1013 location, outside the main code stream, making any adjustments
1014 to the instruction, register, and memory state as directed by
1016 n2) We single-step T over the instruction at its new location.
1017 n3) We adjust the resulting register and memory state as directed
1018 by T's architecture. This includes resetting T's PC to point
1019 back into the main instruction stream.
1022 This approach depends on the following gdbarch methods:
1024 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1025 indicate where to copy the instruction, and how much space must
1026 be reserved there. We use these in step n1.
1028 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1029 address, and makes any necessary adjustments to the instruction,
1030 register contents, and memory. We use this in step n1.
1032 - gdbarch_displaced_step_fixup adjusts registers and memory after
1033 we have successfuly single-stepped the instruction, to yield the
1034 same effect the instruction would have had if we had executed it
1035 at its original address. We use this in step n3.
1037 - gdbarch_displaced_step_free_closure provides cleanup.
1039 The gdbarch_displaced_step_copy_insn and
1040 gdbarch_displaced_step_fixup functions must be written so that
1041 copying an instruction with gdbarch_displaced_step_copy_insn,
1042 single-stepping across the copied instruction, and then applying
1043 gdbarch_displaced_insn_fixup should have the same effects on the
1044 thread's memory and registers as stepping the instruction in place
1045 would have. Exactly which responsibilities fall to the copy and
1046 which fall to the fixup is up to the author of those functions.
1048 See the comments in gdbarch.sh for details.
1050 Note that displaced stepping and software single-step cannot
1051 currently be used in combination, although with some care I think
1052 they could be made to. Software single-step works by placing
1053 breakpoints on all possible subsequent instructions; if the
1054 displaced instruction is a PC-relative jump, those breakpoints
1055 could fall in very strange places --- on pages that aren't
1056 executable, or at addresses that are not proper instruction
1057 boundaries. (We do generally let other threads run while we wait
1058 to hit the software single-step breakpoint, and they might
1059 encounter such a corrupted instruction.) One way to work around
1060 this would be to have gdbarch_displaced_step_copy_insn fully
1061 simulate the effect of PC-relative instructions (and return NULL)
1062 on architectures that use software single-stepping.
1064 In non-stop mode, we can have independent and simultaneous step
1065 requests, so more than one thread may need to simultaneously step
1066 over a breakpoint. The current implementation assumes there is
1067 only one scratch space per process. In this case, we have to
1068 serialize access to the scratch space. If thread A wants to step
1069 over a breakpoint, but we are currently waiting for some other
1070 thread to complete a displaced step, we leave thread A stopped and
1071 place it in the displaced_step_request_queue. Whenever a displaced
1072 step finishes, we pick the next thread in the queue and start a new
1073 displaced step operation on it. See displaced_step_prepare and
1074 displaced_step_fixup for details. */
1076 struct displaced_step_request
1079 struct displaced_step_request *next;
1082 /* Per-inferior displaced stepping state. */
1083 struct displaced_step_inferior_state
1085 /* Pointer to next in linked list. */
1086 struct displaced_step_inferior_state *next;
1088 /* The process this displaced step state refers to. */
1091 /* A queue of pending displaced stepping requests. One entry per
1092 thread that needs to do a displaced step. */
1093 struct displaced_step_request *step_request_queue;
1095 /* If this is not null_ptid, this is the thread carrying out a
1096 displaced single-step in process PID. This thread's state will
1097 require fixing up once it has completed its step. */
1100 /* The architecture the thread had when we stepped it. */
1101 struct gdbarch *step_gdbarch;
1103 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1104 for post-step cleanup. */
1105 struct displaced_step_closure *step_closure;
1107 /* The address of the original instruction, and the copy we
1109 CORE_ADDR step_original, step_copy;
1111 /* Saved contents of copy area. */
1112 gdb_byte *step_saved_copy;
1115 /* The list of states of processes involved in displaced stepping
1117 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1119 /* Get the displaced stepping state of process PID. */
1121 static struct displaced_step_inferior_state *
1122 get_displaced_stepping_state (int pid)
1124 struct displaced_step_inferior_state *state;
1126 for (state = displaced_step_inferior_states;
1128 state = state->next)
1129 if (state->pid == pid)
1135 /* Add a new displaced stepping state for process PID to the displaced
1136 stepping state list, or return a pointer to an already existing
1137 entry, if it already exists. Never returns NULL. */
1139 static struct displaced_step_inferior_state *
1140 add_displaced_stepping_state (int pid)
1142 struct displaced_step_inferior_state *state;
1144 for (state = displaced_step_inferior_states;
1146 state = state->next)
1147 if (state->pid == pid)
1150 state = xcalloc (1, sizeof (*state));
1152 state->next = displaced_step_inferior_states;
1153 displaced_step_inferior_states = state;
1158 /* If inferior is in displaced stepping, and ADDR equals to starting address
1159 of copy area, return corresponding displaced_step_closure. Otherwise,
1162 struct displaced_step_closure*
1163 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1165 struct displaced_step_inferior_state *displaced
1166 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1168 /* If checking the mode of displaced instruction in copy area. */
1169 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1170 && (displaced->step_copy == addr))
1171 return displaced->step_closure;
1176 /* Remove the displaced stepping state of process PID. */
1179 remove_displaced_stepping_state (int pid)
1181 struct displaced_step_inferior_state *it, **prev_next_p;
1183 gdb_assert (pid != 0);
1185 it = displaced_step_inferior_states;
1186 prev_next_p = &displaced_step_inferior_states;
1191 *prev_next_p = it->next;
1196 prev_next_p = &it->next;
1202 infrun_inferior_exit (struct inferior *inf)
1204 remove_displaced_stepping_state (inf->pid);
1207 /* If ON, and the architecture supports it, GDB will use displaced
1208 stepping to step over breakpoints. If OFF, or if the architecture
1209 doesn't support it, GDB will instead use the traditional
1210 hold-and-step approach. If AUTO (which is the default), GDB will
1211 decide which technique to use to step over breakpoints depending on
1212 which of all-stop or non-stop mode is active --- displaced stepping
1213 in non-stop mode; hold-and-step in all-stop mode. */
1215 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1218 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1219 struct cmd_list_element *c,
1222 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1223 fprintf_filtered (file,
1224 _("Debugger's willingness to use displaced stepping "
1225 "to step over breakpoints is %s (currently %s).\n"),
1226 value, non_stop ? "on" : "off");
1228 fprintf_filtered (file,
1229 _("Debugger's willingness to use displaced stepping "
1230 "to step over breakpoints is %s.\n"), value);
1233 /* Return non-zero if displaced stepping can/should be used to step
1234 over breakpoints. */
1237 use_displaced_stepping (struct gdbarch *gdbarch)
1239 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1240 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1241 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1242 && !RECORD_IS_USED);
1245 /* Clean out any stray displaced stepping state. */
1247 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1249 /* Indicate that there is no cleanup pending. */
1250 displaced->step_ptid = null_ptid;
1252 if (displaced->step_closure)
1254 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1255 displaced->step_closure);
1256 displaced->step_closure = NULL;
1261 displaced_step_clear_cleanup (void *arg)
1263 struct displaced_step_inferior_state *state = arg;
1265 displaced_step_clear (state);
1268 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1270 displaced_step_dump_bytes (struct ui_file *file,
1271 const gdb_byte *buf,
1276 for (i = 0; i < len; i++)
1277 fprintf_unfiltered (file, "%02x ", buf[i]);
1278 fputs_unfiltered ("\n", file);
1281 /* Prepare to single-step, using displaced stepping.
1283 Note that we cannot use displaced stepping when we have a signal to
1284 deliver. If we have a signal to deliver and an instruction to step
1285 over, then after the step, there will be no indication from the
1286 target whether the thread entered a signal handler or ignored the
1287 signal and stepped over the instruction successfully --- both cases
1288 result in a simple SIGTRAP. In the first case we mustn't do a
1289 fixup, and in the second case we must --- but we can't tell which.
1290 Comments in the code for 'random signals' in handle_inferior_event
1291 explain how we handle this case instead.
1293 Returns 1 if preparing was successful -- this thread is going to be
1294 stepped now; or 0 if displaced stepping this thread got queued. */
1296 displaced_step_prepare (ptid_t ptid)
1298 struct cleanup *old_cleanups, *ignore_cleanups;
1299 struct thread_info *tp = find_thread_ptid (ptid);
1300 struct regcache *regcache = get_thread_regcache (ptid);
1301 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1302 CORE_ADDR original, copy;
1304 struct displaced_step_closure *closure;
1305 struct displaced_step_inferior_state *displaced;
1308 /* We should never reach this function if the architecture does not
1309 support displaced stepping. */
1310 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1312 /* Disable range stepping while executing in the scratch pad. We
1313 want a single-step even if executing the displaced instruction in
1314 the scratch buffer lands within the stepping range (e.g., a
1316 tp->control.may_range_step = 0;
1318 /* We have to displaced step one thread at a time, as we only have
1319 access to a single scratch space per inferior. */
1321 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1323 if (!ptid_equal (displaced->step_ptid, null_ptid))
1325 /* Already waiting for a displaced step to finish. Defer this
1326 request and place in queue. */
1327 struct displaced_step_request *req, *new_req;
1329 if (debug_displaced)
1330 fprintf_unfiltered (gdb_stdlog,
1331 "displaced: defering step of %s\n",
1332 target_pid_to_str (ptid));
1334 new_req = xmalloc (sizeof (*new_req));
1335 new_req->ptid = ptid;
1336 new_req->next = NULL;
1338 if (displaced->step_request_queue)
1340 for (req = displaced->step_request_queue;
1344 req->next = new_req;
1347 displaced->step_request_queue = new_req;
1353 if (debug_displaced)
1354 fprintf_unfiltered (gdb_stdlog,
1355 "displaced: stepping %s now\n",
1356 target_pid_to_str (ptid));
1359 displaced_step_clear (displaced);
1361 old_cleanups = save_inferior_ptid ();
1362 inferior_ptid = ptid;
1364 original = regcache_read_pc (regcache);
1366 copy = gdbarch_displaced_step_location (gdbarch);
1367 len = gdbarch_max_insn_length (gdbarch);
1369 /* Save the original contents of the copy area. */
1370 displaced->step_saved_copy = xmalloc (len);
1371 ignore_cleanups = make_cleanup (free_current_contents,
1372 &displaced->step_saved_copy);
1373 status = target_read_memory (copy, displaced->step_saved_copy, len);
1375 throw_error (MEMORY_ERROR,
1376 _("Error accessing memory address %s (%s) for "
1377 "displaced-stepping scratch space."),
1378 paddress (gdbarch, copy), safe_strerror (status));
1379 if (debug_displaced)
1381 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1382 paddress (gdbarch, copy));
1383 displaced_step_dump_bytes (gdb_stdlog,
1384 displaced->step_saved_copy,
1388 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1389 original, copy, regcache);
1391 /* We don't support the fully-simulated case at present. */
1392 gdb_assert (closure);
1394 /* Save the information we need to fix things up if the step
1396 displaced->step_ptid = ptid;
1397 displaced->step_gdbarch = gdbarch;
1398 displaced->step_closure = closure;
1399 displaced->step_original = original;
1400 displaced->step_copy = copy;
1402 make_cleanup (displaced_step_clear_cleanup, displaced);
1404 /* Resume execution at the copy. */
1405 regcache_write_pc (regcache, copy);
1407 discard_cleanups (ignore_cleanups);
1409 do_cleanups (old_cleanups);
1411 if (debug_displaced)
1412 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1413 paddress (gdbarch, copy));
1419 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1420 const gdb_byte *myaddr, int len)
1422 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1424 inferior_ptid = ptid;
1425 write_memory (memaddr, myaddr, len);
1426 do_cleanups (ptid_cleanup);
1429 /* Restore the contents of the copy area for thread PTID. */
1432 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1435 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1437 write_memory_ptid (ptid, displaced->step_copy,
1438 displaced->step_saved_copy, len);
1439 if (debug_displaced)
1440 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1441 target_pid_to_str (ptid),
1442 paddress (displaced->step_gdbarch,
1443 displaced->step_copy));
1447 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1449 struct cleanup *old_cleanups;
1450 struct displaced_step_inferior_state *displaced
1451 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1453 /* Was any thread of this process doing a displaced step? */
1454 if (displaced == NULL)
1457 /* Was this event for the pid we displaced? */
1458 if (ptid_equal (displaced->step_ptid, null_ptid)
1459 || ! ptid_equal (displaced->step_ptid, event_ptid))
1462 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1464 displaced_step_restore (displaced, displaced->step_ptid);
1466 /* Did the instruction complete successfully? */
1467 if (signal == GDB_SIGNAL_TRAP)
1469 /* Fix up the resulting state. */
1470 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1471 displaced->step_closure,
1472 displaced->step_original,
1473 displaced->step_copy,
1474 get_thread_regcache (displaced->step_ptid));
1478 /* Since the instruction didn't complete, all we can do is
1480 struct regcache *regcache = get_thread_regcache (event_ptid);
1481 CORE_ADDR pc = regcache_read_pc (regcache);
1483 pc = displaced->step_original + (pc - displaced->step_copy);
1484 regcache_write_pc (regcache, pc);
1487 do_cleanups (old_cleanups);
1489 displaced->step_ptid = null_ptid;
1491 /* Are there any pending displaced stepping requests? If so, run
1492 one now. Leave the state object around, since we're likely to
1493 need it again soon. */
1494 while (displaced->step_request_queue)
1496 struct displaced_step_request *head;
1498 struct regcache *regcache;
1499 struct gdbarch *gdbarch;
1500 CORE_ADDR actual_pc;
1501 struct address_space *aspace;
1503 head = displaced->step_request_queue;
1505 displaced->step_request_queue = head->next;
1508 context_switch (ptid);
1510 regcache = get_thread_regcache (ptid);
1511 actual_pc = regcache_read_pc (regcache);
1512 aspace = get_regcache_aspace (regcache);
1514 if (breakpoint_here_p (aspace, actual_pc))
1516 if (debug_displaced)
1517 fprintf_unfiltered (gdb_stdlog,
1518 "displaced: stepping queued %s now\n",
1519 target_pid_to_str (ptid));
1521 displaced_step_prepare (ptid);
1523 gdbarch = get_regcache_arch (regcache);
1525 if (debug_displaced)
1527 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1530 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1531 paddress (gdbarch, actual_pc));
1532 read_memory (actual_pc, buf, sizeof (buf));
1533 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1536 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1537 displaced->step_closure))
1538 target_resume (ptid, 1, GDB_SIGNAL_0);
1540 target_resume (ptid, 0, GDB_SIGNAL_0);
1542 /* Done, we're stepping a thread. */
1548 struct thread_info *tp = inferior_thread ();
1550 /* The breakpoint we were sitting under has since been
1552 tp->control.trap_expected = 0;
1554 /* Go back to what we were trying to do. */
1555 step = currently_stepping (tp);
1557 if (debug_displaced)
1558 fprintf_unfiltered (gdb_stdlog,
1559 "displaced: breakpoint is gone: %s, step(%d)\n",
1560 target_pid_to_str (tp->ptid), step);
1562 target_resume (ptid, step, GDB_SIGNAL_0);
1563 tp->suspend.stop_signal = GDB_SIGNAL_0;
1565 /* This request was discarded. See if there's any other
1566 thread waiting for its turn. */
1571 /* Update global variables holding ptids to hold NEW_PTID if they were
1572 holding OLD_PTID. */
1574 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1576 struct displaced_step_request *it;
1577 struct displaced_step_inferior_state *displaced;
1579 if (ptid_equal (inferior_ptid, old_ptid))
1580 inferior_ptid = new_ptid;
1582 if (ptid_equal (singlestep_ptid, old_ptid))
1583 singlestep_ptid = new_ptid;
1585 if (ptid_equal (deferred_step_ptid, old_ptid))
1586 deferred_step_ptid = new_ptid;
1588 for (displaced = displaced_step_inferior_states;
1590 displaced = displaced->next)
1592 if (ptid_equal (displaced->step_ptid, old_ptid))
1593 displaced->step_ptid = new_ptid;
1595 for (it = displaced->step_request_queue; it; it = it->next)
1596 if (ptid_equal (it->ptid, old_ptid))
1597 it->ptid = new_ptid;
1604 /* Things to clean up if we QUIT out of resume (). */
1606 resume_cleanups (void *ignore)
1611 static const char schedlock_off[] = "off";
1612 static const char schedlock_on[] = "on";
1613 static const char schedlock_step[] = "step";
1614 static const char *const scheduler_enums[] = {
1620 static const char *scheduler_mode = schedlock_off;
1622 show_scheduler_mode (struct ui_file *file, int from_tty,
1623 struct cmd_list_element *c, const char *value)
1625 fprintf_filtered (file,
1626 _("Mode for locking scheduler "
1627 "during execution is \"%s\".\n"),
1632 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1634 if (!target_can_lock_scheduler)
1636 scheduler_mode = schedlock_off;
1637 error (_("Target '%s' cannot support this command."), target_shortname);
1641 /* True if execution commands resume all threads of all processes by
1642 default; otherwise, resume only threads of the current inferior
1644 int sched_multi = 0;
1646 /* Try to setup for software single stepping over the specified location.
1647 Return 1 if target_resume() should use hardware single step.
1649 GDBARCH the current gdbarch.
1650 PC the location to step over. */
1653 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1657 if (execution_direction == EXEC_FORWARD
1658 && gdbarch_software_single_step_p (gdbarch)
1659 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1662 /* Do not pull these breakpoints until after a `wait' in
1663 `wait_for_inferior'. */
1664 singlestep_breakpoints_inserted_p = 1;
1665 singlestep_ptid = inferior_ptid;
1671 /* Return a ptid representing the set of threads that we will proceed,
1672 in the perspective of the user/frontend. We may actually resume
1673 fewer threads at first, e.g., if a thread is stopped at a
1674 breakpoint that needs stepping-off, but that should not be visible
1675 to the user/frontend, and neither should the frontend/user be
1676 allowed to proceed any of the threads that happen to be stopped for
1677 internal run control handling, if a previous command wanted them
1681 user_visible_resume_ptid (int step)
1683 /* By default, resume all threads of all processes. */
1684 ptid_t resume_ptid = RESUME_ALL;
1686 /* Maybe resume only all threads of the current process. */
1687 if (!sched_multi && target_supports_multi_process ())
1689 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1692 /* Maybe resume a single thread after all. */
1695 /* With non-stop mode on, threads are always handled
1697 resume_ptid = inferior_ptid;
1699 else if ((scheduler_mode == schedlock_on)
1700 || (scheduler_mode == schedlock_step
1701 && (step || singlestep_breakpoints_inserted_p)))
1703 /* User-settable 'scheduler' mode requires solo thread resume. */
1704 resume_ptid = inferior_ptid;
1710 /* Resume the inferior, but allow a QUIT. This is useful if the user
1711 wants to interrupt some lengthy single-stepping operation
1712 (for child processes, the SIGINT goes to the inferior, and so
1713 we get a SIGINT random_signal, but for remote debugging and perhaps
1714 other targets, that's not true).
1716 STEP nonzero if we should step (zero to continue instead).
1717 SIG is the signal to give the inferior (zero for none). */
1719 resume (int step, enum gdb_signal sig)
1721 int should_resume = 1;
1722 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
1723 struct regcache *regcache = get_current_regcache ();
1724 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1725 struct thread_info *tp = inferior_thread ();
1726 CORE_ADDR pc = regcache_read_pc (regcache);
1727 struct address_space *aspace = get_regcache_aspace (regcache);
1731 if (current_inferior ()->waiting_for_vfork_done)
1733 /* Don't try to single-step a vfork parent that is waiting for
1734 the child to get out of the shared memory region (by exec'ing
1735 or exiting). This is particularly important on software
1736 single-step archs, as the child process would trip on the
1737 software single step breakpoint inserted for the parent
1738 process. Since the parent will not actually execute any
1739 instruction until the child is out of the shared region (such
1740 are vfork's semantics), it is safe to simply continue it.
1741 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
1742 the parent, and tell it to `keep_going', which automatically
1743 re-sets it stepping. */
1745 fprintf_unfiltered (gdb_stdlog,
1746 "infrun: resume : clear step\n");
1751 fprintf_unfiltered (gdb_stdlog,
1752 "infrun: resume (step=%d, signal=%d), "
1753 "trap_expected=%d, current thread [%s] at %s\n",
1754 step, sig, tp->control.trap_expected,
1755 target_pid_to_str (inferior_ptid),
1756 paddress (gdbarch, pc));
1758 /* Normally, by the time we reach `resume', the breakpoints are either
1759 removed or inserted, as appropriate. The exception is if we're sitting
1760 at a permanent breakpoint; we need to step over it, but permanent
1761 breakpoints can't be removed. So we have to test for it here. */
1762 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1764 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1765 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1768 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1769 how to step past a permanent breakpoint on this architecture. Try using\n\
1770 a command like `return' or `jump' to continue execution."));
1773 /* If we have a breakpoint to step over, make sure to do a single
1774 step only. Same if we have software watchpoints. */
1775 if (tp->control.trap_expected || bpstat_should_step ())
1776 tp->control.may_range_step = 0;
1778 /* If enabled, step over breakpoints by executing a copy of the
1779 instruction at a different address.
1781 We can't use displaced stepping when we have a signal to deliver;
1782 the comments for displaced_step_prepare explain why. The
1783 comments in the handle_inferior event for dealing with 'random
1784 signals' explain what we do instead.
1786 We can't use displaced stepping when we are waiting for vfork_done
1787 event, displaced stepping breaks the vfork child similarly as single
1788 step software breakpoint. */
1789 if (use_displaced_stepping (gdbarch)
1790 && (tp->control.trap_expected
1791 || (step && gdbarch_software_single_step_p (gdbarch)))
1792 && sig == GDB_SIGNAL_0
1793 && !current_inferior ()->waiting_for_vfork_done)
1795 struct displaced_step_inferior_state *displaced;
1797 if (!displaced_step_prepare (inferior_ptid))
1799 /* Got placed in displaced stepping queue. Will be resumed
1800 later when all the currently queued displaced stepping
1801 requests finish. The thread is not executing at this point,
1802 and the call to set_executing will be made later. But we
1803 need to call set_running here, since from frontend point of view,
1804 the thread is running. */
1805 set_running (inferior_ptid, 1);
1806 discard_cleanups (old_cleanups);
1810 /* Update pc to reflect the new address from which we will execute
1811 instructions due to displaced stepping. */
1812 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
1814 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1815 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
1816 displaced->step_closure);
1819 /* Do we need to do it the hard way, w/temp breakpoints? */
1821 step = maybe_software_singlestep (gdbarch, pc);
1823 /* Currently, our software single-step implementation leads to different
1824 results than hardware single-stepping in one situation: when stepping
1825 into delivering a signal which has an associated signal handler,
1826 hardware single-step will stop at the first instruction of the handler,
1827 while software single-step will simply skip execution of the handler.
1829 For now, this difference in behavior is accepted since there is no
1830 easy way to actually implement single-stepping into a signal handler
1831 without kernel support.
1833 However, there is one scenario where this difference leads to follow-on
1834 problems: if we're stepping off a breakpoint by removing all breakpoints
1835 and then single-stepping. In this case, the software single-step
1836 behavior means that even if there is a *breakpoint* in the signal
1837 handler, GDB still would not stop.
1839 Fortunately, we can at least fix this particular issue. We detect
1840 here the case where we are about to deliver a signal while software
1841 single-stepping with breakpoints removed. In this situation, we
1842 revert the decisions to remove all breakpoints and insert single-
1843 step breakpoints, and instead we install a step-resume breakpoint
1844 at the current address, deliver the signal without stepping, and
1845 once we arrive back at the step-resume breakpoint, actually step
1846 over the breakpoint we originally wanted to step over. */
1847 if (singlestep_breakpoints_inserted_p
1848 && tp->control.trap_expected && sig != GDB_SIGNAL_0)
1850 /* If we have nested signals or a pending signal is delivered
1851 immediately after a handler returns, might might already have
1852 a step-resume breakpoint set on the earlier handler. We cannot
1853 set another step-resume breakpoint; just continue on until the
1854 original breakpoint is hit. */
1855 if (tp->control.step_resume_breakpoint == NULL)
1857 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
1858 tp->step_after_step_resume_breakpoint = 1;
1861 remove_single_step_breakpoints ();
1862 singlestep_breakpoints_inserted_p = 0;
1864 insert_breakpoints ();
1865 tp->control.trap_expected = 0;
1872 /* If STEP is set, it's a request to use hardware stepping
1873 facilities. But in that case, we should never
1874 use singlestep breakpoint. */
1875 gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1877 /* Decide the set of threads to ask the target to resume. Start
1878 by assuming everything will be resumed, than narrow the set
1879 by applying increasingly restricting conditions. */
1880 resume_ptid = user_visible_resume_ptid (step);
1882 /* Maybe resume a single thread after all. */
1883 if (singlestep_breakpoints_inserted_p
1884 && stepping_past_singlestep_breakpoint)
1886 /* The situation here is as follows. In thread T1 we wanted to
1887 single-step. Lacking hardware single-stepping we've
1888 set breakpoint at the PC of the next instruction -- call it
1889 P. After resuming, we've hit that breakpoint in thread T2.
1890 Now we've removed original breakpoint, inserted breakpoint
1891 at P+1, and try to step to advance T2 past breakpoint.
1892 We need to step only T2, as if T1 is allowed to freely run,
1893 it can run past P, and if other threads are allowed to run,
1894 they can hit breakpoint at P+1, and nested hits of single-step
1895 breakpoints is not something we'd want -- that's complicated
1896 to support, and has no value. */
1897 resume_ptid = inferior_ptid;
1899 else if ((step || singlestep_breakpoints_inserted_p)
1900 && tp->control.trap_expected)
1902 /* We're allowing a thread to run past a breakpoint it has
1903 hit, by single-stepping the thread with the breakpoint
1904 removed. In which case, we need to single-step only this
1905 thread, and keep others stopped, as they can miss this
1906 breakpoint if allowed to run.
1908 The current code actually removes all breakpoints when
1909 doing this, not just the one being stepped over, so if we
1910 let other threads run, we can actually miss any
1911 breakpoint, not just the one at PC. */
1912 resume_ptid = inferior_ptid;
1915 if (gdbarch_cannot_step_breakpoint (gdbarch))
1917 /* Most targets can step a breakpoint instruction, thus
1918 executing it normally. But if this one cannot, just
1919 continue and we will hit it anyway. */
1920 if (step && breakpoint_inserted_here_p (aspace, pc))
1925 && use_displaced_stepping (gdbarch)
1926 && tp->control.trap_expected)
1928 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1929 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1930 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1933 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1934 paddress (resume_gdbarch, actual_pc));
1935 read_memory (actual_pc, buf, sizeof (buf));
1936 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1939 if (tp->control.may_range_step)
1941 /* If we're resuming a thread with the PC out of the step
1942 range, then we're doing some nested/finer run control
1943 operation, like stepping the thread out of the dynamic
1944 linker or the displaced stepping scratch pad. We
1945 shouldn't have allowed a range step then. */
1946 gdb_assert (pc_in_thread_step_range (pc, tp));
1949 /* Install inferior's terminal modes. */
1950 target_terminal_inferior ();
1952 /* Avoid confusing the next resume, if the next stop/resume
1953 happens to apply to another thread. */
1954 tp->suspend.stop_signal = GDB_SIGNAL_0;
1956 /* Advise target which signals may be handled silently. If we have
1957 removed breakpoints because we are stepping over one (which can
1958 happen only if we are not using displaced stepping), we need to
1959 receive all signals to avoid accidentally skipping a breakpoint
1960 during execution of a signal handler. */
1961 if ((step || singlestep_breakpoints_inserted_p)
1962 && tp->control.trap_expected
1963 && !use_displaced_stepping (gdbarch))
1964 target_pass_signals (0, NULL);
1966 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
1968 target_resume (resume_ptid, step, sig);
1971 discard_cleanups (old_cleanups);
1976 /* Clear out all variables saying what to do when inferior is continued.
1977 First do this, then set the ones you want, then call `proceed'. */
1980 clear_proceed_status_thread (struct thread_info *tp)
1983 fprintf_unfiltered (gdb_stdlog,
1984 "infrun: clear_proceed_status_thread (%s)\n",
1985 target_pid_to_str (tp->ptid));
1987 tp->control.trap_expected = 0;
1988 tp->control.step_range_start = 0;
1989 tp->control.step_range_end = 0;
1990 tp->control.may_range_step = 0;
1991 tp->control.step_frame_id = null_frame_id;
1992 tp->control.step_stack_frame_id = null_frame_id;
1993 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
1994 tp->stop_requested = 0;
1996 tp->control.stop_step = 0;
1998 tp->control.proceed_to_finish = 0;
2000 /* Discard any remaining commands or status from previous stop. */
2001 bpstat_clear (&tp->control.stop_bpstat);
2005 clear_proceed_status_callback (struct thread_info *tp, void *data)
2007 if (is_exited (tp->ptid))
2010 clear_proceed_status_thread (tp);
2015 clear_proceed_status (void)
2019 /* In all-stop mode, delete the per-thread status of all
2020 threads, even if inferior_ptid is null_ptid, there may be
2021 threads on the list. E.g., we may be launching a new
2022 process, while selecting the executable. */
2023 iterate_over_threads (clear_proceed_status_callback, NULL);
2026 if (!ptid_equal (inferior_ptid, null_ptid))
2028 struct inferior *inferior;
2032 /* If in non-stop mode, only delete the per-thread status of
2033 the current thread. */
2034 clear_proceed_status_thread (inferior_thread ());
2037 inferior = current_inferior ();
2038 inferior->control.stop_soon = NO_STOP_QUIETLY;
2041 stop_after_trap = 0;
2043 observer_notify_about_to_proceed ();
2047 regcache_xfree (stop_registers);
2048 stop_registers = NULL;
2052 /* Check the current thread against the thread that reported the most recent
2053 event. If a step-over is required return TRUE and set the current thread
2054 to the old thread. Otherwise return FALSE.
2056 This should be suitable for any targets that support threads. */
2059 prepare_to_proceed (int step)
2062 struct target_waitstatus wait_status;
2063 int schedlock_enabled;
2065 /* With non-stop mode on, threads are always handled individually. */
2066 gdb_assert (! non_stop);
2068 /* Get the last target status returned by target_wait(). */
2069 get_last_target_status (&wait_ptid, &wait_status);
2071 /* Make sure we were stopped at a breakpoint. */
2072 if (wait_status.kind != TARGET_WAITKIND_STOPPED
2073 || (wait_status.value.sig != GDB_SIGNAL_TRAP
2074 && wait_status.value.sig != GDB_SIGNAL_ILL
2075 && wait_status.value.sig != GDB_SIGNAL_SEGV
2076 && wait_status.value.sig != GDB_SIGNAL_EMT))
2081 schedlock_enabled = (scheduler_mode == schedlock_on
2082 || (scheduler_mode == schedlock_step
2085 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
2086 if (schedlock_enabled)
2089 /* Don't switch over if we're about to resume some other process
2090 other than WAIT_PTID's, and schedule-multiple is off. */
2092 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
2095 /* Switched over from WAIT_PID. */
2096 if (!ptid_equal (wait_ptid, minus_one_ptid)
2097 && !ptid_equal (inferior_ptid, wait_ptid))
2099 struct regcache *regcache = get_thread_regcache (wait_ptid);
2101 if (breakpoint_here_p (get_regcache_aspace (regcache),
2102 regcache_read_pc (regcache)))
2104 /* If stepping, remember current thread to switch back to. */
2106 deferred_step_ptid = inferior_ptid;
2108 /* Switch back to WAIT_PID thread. */
2109 switch_to_thread (wait_ptid);
2112 fprintf_unfiltered (gdb_stdlog,
2113 "infrun: prepare_to_proceed (step=%d), "
2114 "switched to [%s]\n",
2115 step, target_pid_to_str (inferior_ptid));
2117 /* We return 1 to indicate that there is a breakpoint here,
2118 so we need to step over it before continuing to avoid
2119 hitting it straight away. */
2127 /* Basic routine for continuing the program in various fashions.
2129 ADDR is the address to resume at, or -1 for resume where stopped.
2130 SIGGNAL is the signal to give it, or 0 for none,
2131 or -1 for act according to how it stopped.
2132 STEP is nonzero if should trap after one instruction.
2133 -1 means return after that and print nothing.
2134 You should probably set various step_... variables
2135 before calling here, if you are stepping.
2137 You should call clear_proceed_status before calling proceed. */
2140 proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
2142 struct regcache *regcache;
2143 struct gdbarch *gdbarch;
2144 struct thread_info *tp;
2146 struct address_space *aspace;
2147 /* GDB may force the inferior to step due to various reasons. */
2150 /* If we're stopped at a fork/vfork, follow the branch set by the
2151 "set follow-fork-mode" command; otherwise, we'll just proceed
2152 resuming the current thread. */
2153 if (!follow_fork ())
2155 /* The target for some reason decided not to resume. */
2157 if (target_can_async_p ())
2158 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2162 /* We'll update this if & when we switch to a new thread. */
2163 previous_inferior_ptid = inferior_ptid;
2165 regcache = get_current_regcache ();
2166 gdbarch = get_regcache_arch (regcache);
2167 aspace = get_regcache_aspace (regcache);
2168 pc = regcache_read_pc (regcache);
2171 step_start_function = find_pc_function (pc);
2173 stop_after_trap = 1;
2175 if (addr == (CORE_ADDR) -1)
2177 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
2178 && execution_direction != EXEC_REVERSE)
2179 /* There is a breakpoint at the address we will resume at,
2180 step one instruction before inserting breakpoints so that
2181 we do not stop right away (and report a second hit at this
2184 Note, we don't do this in reverse, because we won't
2185 actually be executing the breakpoint insn anyway.
2186 We'll be (un-)executing the previous instruction. */
2189 else if (gdbarch_single_step_through_delay_p (gdbarch)
2190 && gdbarch_single_step_through_delay (gdbarch,
2191 get_current_frame ()))
2192 /* We stepped onto an instruction that needs to be stepped
2193 again before re-inserting the breakpoint, do so. */
2198 regcache_write_pc (regcache, addr);
2202 fprintf_unfiltered (gdb_stdlog,
2203 "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
2204 paddress (gdbarch, addr), siggnal, step);
2207 /* In non-stop, each thread is handled individually. The context
2208 must already be set to the right thread here. */
2212 /* In a multi-threaded task we may select another thread and
2213 then continue or step.
2215 But if the old thread was stopped at a breakpoint, it will
2216 immediately cause another breakpoint stop without any
2217 execution (i.e. it will report a breakpoint hit incorrectly).
2218 So we must step over it first.
2220 prepare_to_proceed checks the current thread against the
2221 thread that reported the most recent event. If a step-over
2222 is required it returns TRUE and sets the current thread to
2224 if (prepare_to_proceed (step))
2228 /* prepare_to_proceed may change the current thread. */
2229 tp = inferior_thread ();
2233 tp->control.trap_expected = 1;
2234 /* If displaced stepping is enabled, we can step over the
2235 breakpoint without hitting it, so leave all breakpoints
2236 inserted. Otherwise we need to disable all breakpoints, step
2237 one instruction, and then re-add them when that step is
2239 if (!use_displaced_stepping (gdbarch))
2240 remove_breakpoints ();
2243 /* We can insert breakpoints if we're not trying to step over one,
2244 or if we are stepping over one but we're using displaced stepping
2246 if (! tp->control.trap_expected || use_displaced_stepping (gdbarch))
2247 insert_breakpoints ();
2251 /* Pass the last stop signal to the thread we're resuming,
2252 irrespective of whether the current thread is the thread that
2253 got the last event or not. This was historically GDB's
2254 behaviour before keeping a stop_signal per thread. */
2256 struct thread_info *last_thread;
2258 struct target_waitstatus last_status;
2260 get_last_target_status (&last_ptid, &last_status);
2261 if (!ptid_equal (inferior_ptid, last_ptid)
2262 && !ptid_equal (last_ptid, null_ptid)
2263 && !ptid_equal (last_ptid, minus_one_ptid))
2265 last_thread = find_thread_ptid (last_ptid);
2268 tp->suspend.stop_signal = last_thread->suspend.stop_signal;
2269 last_thread->suspend.stop_signal = GDB_SIGNAL_0;
2274 if (siggnal != GDB_SIGNAL_DEFAULT)
2275 tp->suspend.stop_signal = siggnal;
2276 /* If this signal should not be seen by program,
2277 give it zero. Used for debugging signals. */
2278 else if (!signal_program[tp->suspend.stop_signal])
2279 tp->suspend.stop_signal = GDB_SIGNAL_0;
2281 annotate_starting ();
2283 /* Make sure that output from GDB appears before output from the
2285 gdb_flush (gdb_stdout);
2287 /* Refresh prev_pc value just prior to resuming. This used to be
2288 done in stop_stepping, however, setting prev_pc there did not handle
2289 scenarios such as inferior function calls or returning from
2290 a function via the return command. In those cases, the prev_pc
2291 value was not set properly for subsequent commands. The prev_pc value
2292 is used to initialize the starting line number in the ecs. With an
2293 invalid value, the gdb next command ends up stopping at the position
2294 represented by the next line table entry past our start position.
2295 On platforms that generate one line table entry per line, this
2296 is not a problem. However, on the ia64, the compiler generates
2297 extraneous line table entries that do not increase the line number.
2298 When we issue the gdb next command on the ia64 after an inferior call
2299 or a return command, we often end up a few instructions forward, still
2300 within the original line we started.
2302 An attempt was made to refresh the prev_pc at the same time the
2303 execution_control_state is initialized (for instance, just before
2304 waiting for an inferior event). But this approach did not work
2305 because of platforms that use ptrace, where the pc register cannot
2306 be read unless the inferior is stopped. At that point, we are not
2307 guaranteed the inferior is stopped and so the regcache_read_pc() call
2308 can fail. Setting the prev_pc value here ensures the value is updated
2309 correctly when the inferior is stopped. */
2310 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2312 /* Fill in with reasonable starting values. */
2313 init_thread_stepping_state (tp);
2315 /* Reset to normal state. */
2316 init_infwait_state ();
2318 /* Resume inferior. */
2319 resume (force_step || step || bpstat_should_step (),
2320 tp->suspend.stop_signal);
2322 /* Wait for it to stop (if not standalone)
2323 and in any case decode why it stopped, and act accordingly. */
2324 /* Do this only if we are not using the event loop, or if the target
2325 does not support asynchronous execution. */
2326 if (!target_can_async_p ())
2328 wait_for_inferior ();
2334 /* Start remote-debugging of a machine over a serial link. */
2337 start_remote (int from_tty)
2339 struct inferior *inferior;
2341 inferior = current_inferior ();
2342 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2344 /* Always go on waiting for the target, regardless of the mode. */
2345 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2346 indicate to wait_for_inferior that a target should timeout if
2347 nothing is returned (instead of just blocking). Because of this,
2348 targets expecting an immediate response need to, internally, set
2349 things up so that the target_wait() is forced to eventually
2351 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2352 differentiate to its caller what the state of the target is after
2353 the initial open has been performed. Here we're assuming that
2354 the target has stopped. It should be possible to eventually have
2355 target_open() return to the caller an indication that the target
2356 is currently running and GDB state should be set to the same as
2357 for an async run. */
2358 wait_for_inferior ();
2360 /* Now that the inferior has stopped, do any bookkeeping like
2361 loading shared libraries. We want to do this before normal_stop,
2362 so that the displayed frame is up to date. */
2363 post_create_inferior (¤t_target, from_tty);
2368 /* Initialize static vars when a new inferior begins. */
2371 init_wait_for_inferior (void)
2373 /* These are meaningless until the first time through wait_for_inferior. */
2375 breakpoint_init_inferior (inf_starting);
2377 clear_proceed_status ();
2379 stepping_past_singlestep_breakpoint = 0;
2380 deferred_step_ptid = null_ptid;
2382 target_last_wait_ptid = minus_one_ptid;
2384 previous_inferior_ptid = inferior_ptid;
2385 init_infwait_state ();
2387 /* Discard any skipped inlined frames. */
2388 clear_inline_frame_state (minus_one_ptid);
2392 /* This enum encodes possible reasons for doing a target_wait, so that
2393 wfi can call target_wait in one place. (Ultimately the call will be
2394 moved out of the infinite loop entirely.) */
2398 infwait_normal_state,
2399 infwait_thread_hop_state,
2400 infwait_step_watch_state,
2401 infwait_nonstep_watch_state
2404 /* The PTID we'll do a target_wait on.*/
2407 /* Current inferior wait state. */
2408 static enum infwait_states infwait_state;
2410 /* Data to be passed around while handling an event. This data is
2411 discarded between events. */
2412 struct execution_control_state
2415 /* The thread that got the event, if this was a thread event; NULL
2417 struct thread_info *event_thread;
2419 struct target_waitstatus ws;
2421 int stop_func_filled_in;
2422 CORE_ADDR stop_func_start;
2423 CORE_ADDR stop_func_end;
2424 const char *stop_func_name;
2428 static void handle_inferior_event (struct execution_control_state *ecs);
2430 static void handle_step_into_function (struct gdbarch *gdbarch,
2431 struct execution_control_state *ecs);
2432 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2433 struct execution_control_state *ecs);
2434 static void check_exception_resume (struct execution_control_state *,
2435 struct frame_info *);
2437 static void stop_stepping (struct execution_control_state *ecs);
2438 static void prepare_to_wait (struct execution_control_state *ecs);
2439 static void keep_going (struct execution_control_state *ecs);
2441 /* Callback for iterate over threads. If the thread is stopped, but
2442 the user/frontend doesn't know about that yet, go through
2443 normal_stop, as if the thread had just stopped now. ARG points at
2444 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2445 ptid_is_pid(PTID) is true, applies to all threads of the process
2446 pointed at by PTID. Otherwise, apply only to the thread pointed by
2450 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2452 ptid_t ptid = * (ptid_t *) arg;
2454 if ((ptid_equal (info->ptid, ptid)
2455 || ptid_equal (minus_one_ptid, ptid)
2456 || (ptid_is_pid (ptid)
2457 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2458 && is_running (info->ptid)
2459 && !is_executing (info->ptid))
2461 struct cleanup *old_chain;
2462 struct execution_control_state ecss;
2463 struct execution_control_state *ecs = &ecss;
2465 memset (ecs, 0, sizeof (*ecs));
2467 old_chain = make_cleanup_restore_current_thread ();
2469 /* Go through handle_inferior_event/normal_stop, so we always
2470 have consistent output as if the stop event had been
2472 ecs->ptid = info->ptid;
2473 ecs->event_thread = find_thread_ptid (info->ptid);
2474 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2475 ecs->ws.value.sig = GDB_SIGNAL_0;
2477 handle_inferior_event (ecs);
2479 if (!ecs->wait_some_more)
2481 struct thread_info *tp;
2485 /* Finish off the continuations. */
2486 tp = inferior_thread ();
2487 do_all_intermediate_continuations_thread (tp, 1);
2488 do_all_continuations_thread (tp, 1);
2491 do_cleanups (old_chain);
2497 /* This function is attached as a "thread_stop_requested" observer.
2498 Cleanup local state that assumed the PTID was to be resumed, and
2499 report the stop to the frontend. */
2502 infrun_thread_stop_requested (ptid_t ptid)
2504 struct displaced_step_inferior_state *displaced;
2506 /* PTID was requested to stop. Remove it from the displaced
2507 stepping queue, so we don't try to resume it automatically. */
2509 for (displaced = displaced_step_inferior_states;
2511 displaced = displaced->next)
2513 struct displaced_step_request *it, **prev_next_p;
2515 it = displaced->step_request_queue;
2516 prev_next_p = &displaced->step_request_queue;
2519 if (ptid_match (it->ptid, ptid))
2521 *prev_next_p = it->next;
2527 prev_next_p = &it->next;
2534 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2538 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2540 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2541 nullify_last_target_wait_ptid ();
2544 /* Callback for iterate_over_threads. */
2547 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2549 if (is_exited (info->ptid))
2552 delete_step_resume_breakpoint (info);
2553 delete_exception_resume_breakpoint (info);
2557 /* In all-stop, delete the step resume breakpoint of any thread that
2558 had one. In non-stop, delete the step resume breakpoint of the
2559 thread that just stopped. */
2562 delete_step_thread_step_resume_breakpoint (void)
2564 if (!target_has_execution
2565 || ptid_equal (inferior_ptid, null_ptid))
2566 /* If the inferior has exited, we have already deleted the step
2567 resume breakpoints out of GDB's lists. */
2572 /* If in non-stop mode, only delete the step-resume or
2573 longjmp-resume breakpoint of the thread that just stopped
2575 struct thread_info *tp = inferior_thread ();
2577 delete_step_resume_breakpoint (tp);
2578 delete_exception_resume_breakpoint (tp);
2581 /* In all-stop mode, delete all step-resume and longjmp-resume
2582 breakpoints of any thread that had them. */
2583 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2586 /* A cleanup wrapper. */
2589 delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2591 delete_step_thread_step_resume_breakpoint ();
2594 /* Pretty print the results of target_wait, for debugging purposes. */
2597 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2598 const struct target_waitstatus *ws)
2600 char *status_string = target_waitstatus_to_string (ws);
2601 struct ui_file *tmp_stream = mem_fileopen ();
2604 /* The text is split over several lines because it was getting too long.
2605 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2606 output as a unit; we want only one timestamp printed if debug_timestamp
2609 fprintf_unfiltered (tmp_stream,
2610 "infrun: target_wait (%d", ptid_get_pid (waiton_ptid));
2611 if (ptid_get_pid (waiton_ptid) != -1)
2612 fprintf_unfiltered (tmp_stream,
2613 " [%s]", target_pid_to_str (waiton_ptid));
2614 fprintf_unfiltered (tmp_stream, ", status) =\n");
2615 fprintf_unfiltered (tmp_stream,
2616 "infrun: %d [%s],\n",
2617 ptid_get_pid (result_ptid),
2618 target_pid_to_str (result_ptid));
2619 fprintf_unfiltered (tmp_stream,
2623 text = ui_file_xstrdup (tmp_stream, NULL);
2625 /* This uses %s in part to handle %'s in the text, but also to avoid
2626 a gcc error: the format attribute requires a string literal. */
2627 fprintf_unfiltered (gdb_stdlog, "%s", text);
2629 xfree (status_string);
2631 ui_file_delete (tmp_stream);
2634 /* Prepare and stabilize the inferior for detaching it. E.g.,
2635 detaching while a thread is displaced stepping is a recipe for
2636 crashing it, as nothing would readjust the PC out of the scratch
2640 prepare_for_detach (void)
2642 struct inferior *inf = current_inferior ();
2643 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2644 struct cleanup *old_chain_1;
2645 struct displaced_step_inferior_state *displaced;
2647 displaced = get_displaced_stepping_state (inf->pid);
2649 /* Is any thread of this process displaced stepping? If not,
2650 there's nothing else to do. */
2651 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2655 fprintf_unfiltered (gdb_stdlog,
2656 "displaced-stepping in-process while detaching");
2658 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2661 while (!ptid_equal (displaced->step_ptid, null_ptid))
2663 struct cleanup *old_chain_2;
2664 struct execution_control_state ecss;
2665 struct execution_control_state *ecs;
2668 memset (ecs, 0, sizeof (*ecs));
2670 overlay_cache_invalid = 1;
2672 if (deprecated_target_wait_hook)
2673 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
2675 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
2678 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
2680 /* If an error happens while handling the event, propagate GDB's
2681 knowledge of the executing state to the frontend/user running
2683 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
2686 /* Now figure out what to do with the result of the result. */
2687 handle_inferior_event (ecs);
2689 /* No error, don't finish the state yet. */
2690 discard_cleanups (old_chain_2);
2692 /* Breakpoints and watchpoints are not installed on the target
2693 at this point, and signals are passed directly to the
2694 inferior, so this must mean the process is gone. */
2695 if (!ecs->wait_some_more)
2697 discard_cleanups (old_chain_1);
2698 error (_("Program exited while detaching"));
2702 discard_cleanups (old_chain_1);
2705 /* Wait for control to return from inferior to debugger.
2707 If inferior gets a signal, we may decide to start it up again
2708 instead of returning. That is why there is a loop in this function.
2709 When this function actually returns it means the inferior
2710 should be left stopped and GDB should read more commands. */
2713 wait_for_inferior (void)
2715 struct cleanup *old_cleanups;
2719 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
2722 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2726 struct execution_control_state ecss;
2727 struct execution_control_state *ecs = &ecss;
2728 struct cleanup *old_chain;
2730 memset (ecs, 0, sizeof (*ecs));
2732 overlay_cache_invalid = 1;
2734 if (deprecated_target_wait_hook)
2735 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2737 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2740 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2742 /* If an error happens while handling the event, propagate GDB's
2743 knowledge of the executing state to the frontend/user running
2745 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2747 /* Now figure out what to do with the result of the result. */
2748 handle_inferior_event (ecs);
2750 /* No error, don't finish the state yet. */
2751 discard_cleanups (old_chain);
2753 if (!ecs->wait_some_more)
2757 do_cleanups (old_cleanups);
2760 /* Asynchronous version of wait_for_inferior. It is called by the
2761 event loop whenever a change of state is detected on the file
2762 descriptor corresponding to the target. It can be called more than
2763 once to complete a single execution command. In such cases we need
2764 to keep the state in a global variable ECSS. If it is the last time
2765 that this function is called for a single execution command, then
2766 report to the user that the inferior has stopped, and do the
2767 necessary cleanups. */
2770 fetch_inferior_event (void *client_data)
2772 struct execution_control_state ecss;
2773 struct execution_control_state *ecs = &ecss;
2774 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2775 struct cleanup *ts_old_chain;
2776 int was_sync = sync_execution;
2779 memset (ecs, 0, sizeof (*ecs));
2781 /* We're handling a live event, so make sure we're doing live
2782 debugging. If we're looking at traceframes while the target is
2783 running, we're going to need to get back to that mode after
2784 handling the event. */
2787 make_cleanup_restore_current_traceframe ();
2788 set_current_traceframe (-1);
2792 /* In non-stop mode, the user/frontend should not notice a thread
2793 switch due to internal events. Make sure we reverse to the
2794 user selected thread and frame after handling the event and
2795 running any breakpoint commands. */
2796 make_cleanup_restore_current_thread ();
2798 overlay_cache_invalid = 1;
2800 make_cleanup_restore_integer (&execution_direction);
2801 execution_direction = target_execution_direction ();
2803 if (deprecated_target_wait_hook)
2805 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2807 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2810 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2812 /* If an error happens while handling the event, propagate GDB's
2813 knowledge of the executing state to the frontend/user running
2816 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2818 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2820 /* Get executed before make_cleanup_restore_current_thread above to apply
2821 still for the thread which has thrown the exception. */
2822 make_bpstat_clear_actions_cleanup ();
2824 /* Now figure out what to do with the result of the result. */
2825 handle_inferior_event (ecs);
2827 if (!ecs->wait_some_more)
2829 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2831 delete_step_thread_step_resume_breakpoint ();
2833 /* We may not find an inferior if this was a process exit. */
2834 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
2837 if (target_has_execution
2838 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
2839 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2840 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2841 && ecs->event_thread->step_multi
2842 && ecs->event_thread->control.stop_step)
2843 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2846 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2851 /* No error, don't finish the thread states yet. */
2852 discard_cleanups (ts_old_chain);
2854 /* Revert thread and frame. */
2855 do_cleanups (old_chain);
2857 /* If the inferior was in sync execution mode, and now isn't,
2858 restore the prompt (a synchronous execution command has finished,
2859 and we're ready for input). */
2860 if (interpreter_async && was_sync && !sync_execution)
2861 display_gdb_prompt (0);
2865 && exec_done_display_p
2866 && (ptid_equal (inferior_ptid, null_ptid)
2867 || !is_running (inferior_ptid)))
2868 printf_unfiltered (_("completed.\n"));
2871 /* Record the frame and location we're currently stepping through. */
2873 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2875 struct thread_info *tp = inferior_thread ();
2877 tp->control.step_frame_id = get_frame_id (frame);
2878 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
2880 tp->current_symtab = sal.symtab;
2881 tp->current_line = sal.line;
2884 /* Clear context switchable stepping state. */
2887 init_thread_stepping_state (struct thread_info *tss)
2889 tss->stepping_over_breakpoint = 0;
2890 tss->step_after_step_resume_breakpoint = 0;
2893 /* Return the cached copy of the last pid/waitstatus returned by
2894 target_wait()/deprecated_target_wait_hook(). The data is actually
2895 cached by handle_inferior_event(), which gets called immediately
2896 after target_wait()/deprecated_target_wait_hook(). */
2899 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2901 *ptidp = target_last_wait_ptid;
2902 *status = target_last_waitstatus;
2906 nullify_last_target_wait_ptid (void)
2908 target_last_wait_ptid = minus_one_ptid;
2911 /* Switch thread contexts. */
2914 context_switch (ptid_t ptid)
2916 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
2918 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2919 target_pid_to_str (inferior_ptid));
2920 fprintf_unfiltered (gdb_stdlog, "to %s\n",
2921 target_pid_to_str (ptid));
2924 switch_to_thread (ptid);
2928 adjust_pc_after_break (struct execution_control_state *ecs)
2930 struct regcache *regcache;
2931 struct gdbarch *gdbarch;
2932 struct address_space *aspace;
2933 CORE_ADDR breakpoint_pc;
2935 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2936 we aren't, just return.
2938 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2939 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2940 implemented by software breakpoints should be handled through the normal
2943 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2944 different signals (SIGILL or SIGEMT for instance), but it is less
2945 clear where the PC is pointing afterwards. It may not match
2946 gdbarch_decr_pc_after_break. I don't know any specific target that
2947 generates these signals at breakpoints (the code has been in GDB since at
2948 least 1992) so I can not guess how to handle them here.
2950 In earlier versions of GDB, a target with
2951 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2952 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2953 target with both of these set in GDB history, and it seems unlikely to be
2954 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2956 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2959 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
2962 /* In reverse execution, when a breakpoint is hit, the instruction
2963 under it has already been de-executed. The reported PC always
2964 points at the breakpoint address, so adjusting it further would
2965 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2968 B1 0x08000000 : INSN1
2969 B2 0x08000001 : INSN2
2971 PC -> 0x08000003 : INSN4
2973 Say you're stopped at 0x08000003 as above. Reverse continuing
2974 from that point should hit B2 as below. Reading the PC when the
2975 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2976 been de-executed already.
2978 B1 0x08000000 : INSN1
2979 B2 PC -> 0x08000001 : INSN2
2983 We can't apply the same logic as for forward execution, because
2984 we would wrongly adjust the PC to 0x08000000, since there's a
2985 breakpoint at PC - 1. We'd then report a hit on B1, although
2986 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2988 if (execution_direction == EXEC_REVERSE)
2991 /* If this target does not decrement the PC after breakpoints, then
2992 we have nothing to do. */
2993 regcache = get_thread_regcache (ecs->ptid);
2994 gdbarch = get_regcache_arch (regcache);
2995 if (gdbarch_decr_pc_after_break (gdbarch) == 0)
2998 aspace = get_regcache_aspace (regcache);
3000 /* Find the location where (if we've hit a breakpoint) the
3001 breakpoint would be. */
3002 breakpoint_pc = regcache_read_pc (regcache)
3003 - gdbarch_decr_pc_after_break (gdbarch);
3005 /* Check whether there actually is a software breakpoint inserted at
3008 If in non-stop mode, a race condition is possible where we've
3009 removed a breakpoint, but stop events for that breakpoint were
3010 already queued and arrive later. To suppress those spurious
3011 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3012 and retire them after a number of stop events are reported. */
3013 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3014 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3016 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
3019 record_full_gdb_operation_disable_set ();
3021 /* When using hardware single-step, a SIGTRAP is reported for both
3022 a completed single-step and a software breakpoint. Need to
3023 differentiate between the two, as the latter needs adjusting
3024 but the former does not.
3026 The SIGTRAP can be due to a completed hardware single-step only if
3027 - we didn't insert software single-step breakpoints
3028 - the thread to be examined is still the current thread
3029 - this thread is currently being stepped
3031 If any of these events did not occur, we must have stopped due
3032 to hitting a software breakpoint, and have to back up to the
3035 As a special case, we could have hardware single-stepped a
3036 software breakpoint. In this case (prev_pc == breakpoint_pc),
3037 we also need to back up to the breakpoint address. */
3039 if (singlestep_breakpoints_inserted_p
3040 || !ptid_equal (ecs->ptid, inferior_ptid)
3041 || !currently_stepping (ecs->event_thread)
3042 || ecs->event_thread->prev_pc == breakpoint_pc)
3043 regcache_write_pc (regcache, breakpoint_pc);
3045 do_cleanups (old_cleanups);
3050 init_infwait_state (void)
3052 waiton_ptid = pid_to_ptid (-1);
3053 infwait_state = infwait_normal_state;
3057 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3059 for (frame = get_prev_frame (frame);
3061 frame = get_prev_frame (frame))
3063 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3065 if (get_frame_type (frame) != INLINE_FRAME)
3072 /* Auxiliary function that handles syscall entry/return events.
3073 It returns 1 if the inferior should keep going (and GDB
3074 should ignore the event), or 0 if the event deserves to be
3078 handle_syscall_event (struct execution_control_state *ecs)
3080 struct regcache *regcache;
3083 if (!ptid_equal (ecs->ptid, inferior_ptid))
3084 context_switch (ecs->ptid);
3086 regcache = get_thread_regcache (ecs->ptid);
3087 syscall_number = ecs->ws.value.syscall_number;
3088 stop_pc = regcache_read_pc (regcache);
3090 if (catch_syscall_enabled () > 0
3091 && catching_syscall_number (syscall_number) > 0)
3093 enum bpstat_signal_value sval;
3096 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3099 ecs->event_thread->control.stop_bpstat
3100 = bpstat_stop_status (get_regcache_aspace (regcache),
3101 stop_pc, ecs->ptid, &ecs->ws);
3103 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3105 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3107 if (!ecs->random_signal)
3109 /* Catchpoint hit. */
3110 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3115 /* If no catchpoint triggered for this, then keep going. */
3116 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3121 /* Clear the supplied execution_control_state's stop_func_* fields. */
3124 clear_stop_func (struct execution_control_state *ecs)
3126 ecs->stop_func_filled_in = 0;
3127 ecs->stop_func_start = 0;
3128 ecs->stop_func_end = 0;
3129 ecs->stop_func_name = NULL;
3132 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3135 fill_in_stop_func (struct gdbarch *gdbarch,
3136 struct execution_control_state *ecs)
3138 if (!ecs->stop_func_filled_in)
3140 /* Don't care about return value; stop_func_start and stop_func_name
3141 will both be 0 if it doesn't work. */
3142 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3143 &ecs->stop_func_start, &ecs->stop_func_end);
3144 ecs->stop_func_start
3145 += gdbarch_deprecated_function_start_offset (gdbarch);
3147 ecs->stop_func_filled_in = 1;
3151 /* Given an execution control state that has been freshly filled in
3152 by an event from the inferior, figure out what it means and take
3153 appropriate action. */
3156 handle_inferior_event (struct execution_control_state *ecs)
3158 struct frame_info *frame;
3159 struct gdbarch *gdbarch;
3160 int stopped_by_watchpoint;
3161 int stepped_after_stopped_by_watchpoint = 0;
3162 struct symtab_and_line stop_pc_sal;
3163 enum stop_kind stop_soon;
3165 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3167 /* We had an event in the inferior, but we are not interested in
3168 handling it at this level. The lower layers have already
3169 done what needs to be done, if anything.
3171 One of the possible circumstances for this is when the
3172 inferior produces output for the console. The inferior has
3173 not stopped, and we are ignoring the event. Another possible
3174 circumstance is any event which the lower level knows will be
3175 reported multiple times without an intervening resume. */
3177 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3178 prepare_to_wait (ecs);
3182 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3183 && target_can_async_p () && !sync_execution)
3185 /* There were no unwaited-for children left in the target, but,
3186 we're not synchronously waiting for events either. Just
3187 ignore. Otherwise, if we were running a synchronous
3188 execution command, we need to cancel it and give the user
3189 back the terminal. */
3191 fprintf_unfiltered (gdb_stdlog,
3192 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3193 prepare_to_wait (ecs);
3197 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3198 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3199 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED)
3201 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
3204 stop_soon = inf->control.stop_soon;
3207 stop_soon = NO_STOP_QUIETLY;
3209 /* Cache the last pid/waitstatus. */
3210 target_last_wait_ptid = ecs->ptid;
3211 target_last_waitstatus = ecs->ws;
3213 /* Always clear state belonging to the previous time we stopped. */
3214 stop_stack_dummy = STOP_NONE;
3216 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3218 /* No unwaited-for children left. IOW, all resumed children
3221 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3223 stop_print_frame = 0;
3224 stop_stepping (ecs);
3228 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3229 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3231 ecs->event_thread = find_thread_ptid (ecs->ptid);
3232 /* If it's a new thread, add it to the thread database. */
3233 if (ecs->event_thread == NULL)
3234 ecs->event_thread = add_thread (ecs->ptid);
3236 /* Disable range stepping. If the next step request could use a
3237 range, this will be end up re-enabled then. */
3238 ecs->event_thread->control.may_range_step = 0;
3241 /* Dependent on valid ECS->EVENT_THREAD. */
3242 adjust_pc_after_break (ecs);
3244 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3245 reinit_frame_cache ();
3247 breakpoint_retire_moribund ();
3249 /* First, distinguish signals caused by the debugger from signals
3250 that have to do with the program's own actions. Note that
3251 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3252 on the operating system version. Here we detect when a SIGILL or
3253 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3254 something similar for SIGSEGV, since a SIGSEGV will be generated
3255 when we're trying to execute a breakpoint instruction on a
3256 non-executable stack. This happens for call dummy breakpoints
3257 for architectures like SPARC that place call dummies on the
3259 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3260 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3261 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3262 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3264 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3266 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3267 regcache_read_pc (regcache)))
3270 fprintf_unfiltered (gdb_stdlog,
3271 "infrun: Treating signal as SIGTRAP\n");
3272 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3276 /* Mark the non-executing threads accordingly. In all-stop, all
3277 threads of all processes are stopped when we get any event
3278 reported. In non-stop mode, only the event thread stops. If
3279 we're handling a process exit in non-stop mode, there's nothing
3280 to do, as threads of the dead process are gone, and threads of
3281 any other process were left running. */
3283 set_executing (minus_one_ptid, 0);
3284 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3285 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3286 set_executing (ecs->ptid, 0);
3288 switch (infwait_state)
3290 case infwait_thread_hop_state:
3292 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
3295 case infwait_normal_state:
3297 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
3300 case infwait_step_watch_state:
3302 fprintf_unfiltered (gdb_stdlog,
3303 "infrun: infwait_step_watch_state\n");
3305 stepped_after_stopped_by_watchpoint = 1;
3308 case infwait_nonstep_watch_state:
3310 fprintf_unfiltered (gdb_stdlog,
3311 "infrun: infwait_nonstep_watch_state\n");
3312 insert_breakpoints ();
3314 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3315 handle things like signals arriving and other things happening
3316 in combination correctly? */
3317 stepped_after_stopped_by_watchpoint = 1;
3321 internal_error (__FILE__, __LINE__, _("bad switch"));
3324 infwait_state = infwait_normal_state;
3325 waiton_ptid = pid_to_ptid (-1);
3327 switch (ecs->ws.kind)
3329 case TARGET_WAITKIND_LOADED:
3331 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3332 /* Ignore gracefully during startup of the inferior, as it might
3333 be the shell which has just loaded some objects, otherwise
3334 add the symbols for the newly loaded objects. Also ignore at
3335 the beginning of an attach or remote session; we will query
3336 the full list of libraries once the connection is
3338 if (stop_soon == NO_STOP_QUIETLY)
3340 struct regcache *regcache;
3341 enum bpstat_signal_value sval;
3343 if (!ptid_equal (ecs->ptid, inferior_ptid))
3344 context_switch (ecs->ptid);
3345 regcache = get_thread_regcache (ecs->ptid);
3347 handle_solib_event ();
3349 ecs->event_thread->control.stop_bpstat
3350 = bpstat_stop_status (get_regcache_aspace (regcache),
3351 stop_pc, ecs->ptid, &ecs->ws);
3354 = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3356 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3358 if (!ecs->random_signal)
3360 /* A catchpoint triggered. */
3361 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3362 goto process_event_stop_test;
3365 /* If requested, stop when the dynamic linker notifies
3366 gdb of events. This allows the user to get control
3367 and place breakpoints in initializer routines for
3368 dynamically loaded objects (among other things). */
3369 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3370 if (stop_on_solib_events)
3372 /* Make sure we print "Stopped due to solib-event" in
3374 stop_print_frame = 1;
3376 stop_stepping (ecs);
3381 /* If we are skipping through a shell, or through shared library
3382 loading that we aren't interested in, resume the program. If
3383 we're running the program normally, also resume. But stop if
3384 we're attaching or setting up a remote connection. */
3385 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3387 if (!ptid_equal (ecs->ptid, inferior_ptid))
3388 context_switch (ecs->ptid);
3390 /* Loading of shared libraries might have changed breakpoint
3391 addresses. Make sure new breakpoints are inserted. */
3392 if (stop_soon == NO_STOP_QUIETLY
3393 && !breakpoints_always_inserted_mode ())
3394 insert_breakpoints ();
3395 resume (0, GDB_SIGNAL_0);
3396 prepare_to_wait (ecs);
3402 case TARGET_WAITKIND_SPURIOUS:
3404 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3405 if (!ptid_equal (ecs->ptid, inferior_ptid))
3406 context_switch (ecs->ptid);
3407 resume (0, GDB_SIGNAL_0);
3408 prepare_to_wait (ecs);
3411 case TARGET_WAITKIND_EXITED:
3412 case TARGET_WAITKIND_SIGNALLED:
3415 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3416 fprintf_unfiltered (gdb_stdlog,
3417 "infrun: TARGET_WAITKIND_EXITED\n");
3419 fprintf_unfiltered (gdb_stdlog,
3420 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3423 inferior_ptid = ecs->ptid;
3424 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3425 set_current_program_space (current_inferior ()->pspace);
3426 handle_vfork_child_exec_or_exit (0);
3427 target_terminal_ours (); /* Must do this before mourn anyway. */
3429 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3431 /* Record the exit code in the convenience variable $_exitcode, so
3432 that the user can inspect this again later. */
3433 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3434 (LONGEST) ecs->ws.value.integer);
3436 /* Also record this in the inferior itself. */
3437 current_inferior ()->has_exit_code = 1;
3438 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3440 print_exited_reason (ecs->ws.value.integer);
3443 print_signal_exited_reason (ecs->ws.value.sig);
3445 gdb_flush (gdb_stdout);
3446 target_mourn_inferior ();
3447 singlestep_breakpoints_inserted_p = 0;
3448 cancel_single_step_breakpoints ();
3449 stop_print_frame = 0;
3450 stop_stepping (ecs);
3453 /* The following are the only cases in which we keep going;
3454 the above cases end in a continue or goto. */
3455 case TARGET_WAITKIND_FORKED:
3456 case TARGET_WAITKIND_VFORKED:
3459 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3460 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3462 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3465 /* Check whether the inferior is displaced stepping. */
3467 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3468 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3469 struct displaced_step_inferior_state *displaced
3470 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3472 /* If checking displaced stepping is supported, and thread
3473 ecs->ptid is displaced stepping. */
3474 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3476 struct inferior *parent_inf
3477 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3478 struct regcache *child_regcache;
3479 CORE_ADDR parent_pc;
3481 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3482 indicating that the displaced stepping of syscall instruction
3483 has been done. Perform cleanup for parent process here. Note
3484 that this operation also cleans up the child process for vfork,
3485 because their pages are shared. */
3486 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3488 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3490 /* Restore scratch pad for child process. */
3491 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3494 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3495 the child's PC is also within the scratchpad. Set the child's PC
3496 to the parent's PC value, which has already been fixed up.
3497 FIXME: we use the parent's aspace here, although we're touching
3498 the child, because the child hasn't been added to the inferior
3499 list yet at this point. */
3502 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3504 parent_inf->aspace);
3505 /* Read PC value of parent process. */
3506 parent_pc = regcache_read_pc (regcache);
3508 if (debug_displaced)
3509 fprintf_unfiltered (gdb_stdlog,
3510 "displaced: write child pc from %s to %s\n",
3512 regcache_read_pc (child_regcache)),
3513 paddress (gdbarch, parent_pc));
3515 regcache_write_pc (child_regcache, parent_pc);
3519 if (!ptid_equal (ecs->ptid, inferior_ptid))
3520 context_switch (ecs->ptid);
3522 /* Immediately detach breakpoints from the child before there's
3523 any chance of letting the user delete breakpoints from the
3524 breakpoint lists. If we don't do this early, it's easy to
3525 leave left over traps in the child, vis: "break foo; catch
3526 fork; c; <fork>; del; c; <child calls foo>". We only follow
3527 the fork on the last `continue', and by that time the
3528 breakpoint at "foo" is long gone from the breakpoint table.
3529 If we vforked, then we don't need to unpatch here, since both
3530 parent and child are sharing the same memory pages; we'll
3531 need to unpatch at follow/detach time instead to be certain
3532 that new breakpoints added between catchpoint hit time and
3533 vfork follow are detached. */
3534 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3536 /* This won't actually modify the breakpoint list, but will
3537 physically remove the breakpoints from the child. */
3538 detach_breakpoints (ecs->ws.value.related_pid);
3541 if (singlestep_breakpoints_inserted_p)
3543 /* Pull the single step breakpoints out of the target. */
3544 remove_single_step_breakpoints ();
3545 singlestep_breakpoints_inserted_p = 0;
3548 /* In case the event is caught by a catchpoint, remember that
3549 the event is to be followed at the next resume of the thread,
3550 and not immediately. */
3551 ecs->event_thread->pending_follow = ecs->ws;
3553 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3555 ecs->event_thread->control.stop_bpstat
3556 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3557 stop_pc, ecs->ptid, &ecs->ws);
3559 /* Note that we're interested in knowing the bpstat actually
3560 causes a stop, not just if it may explain the signal.
3561 Software watchpoints, for example, always appear in the
3564 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat);
3566 /* If no catchpoint triggered for this, then keep going. */
3567 if (ecs->random_signal)
3573 = (follow_fork_mode_string == follow_fork_mode_child);
3575 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3577 should_resume = follow_fork ();
3580 child = ecs->ws.value.related_pid;
3582 /* In non-stop mode, also resume the other branch. */
3583 if (non_stop && !detach_fork)
3586 switch_to_thread (parent);
3588 switch_to_thread (child);
3590 ecs->event_thread = inferior_thread ();
3591 ecs->ptid = inferior_ptid;
3596 switch_to_thread (child);
3598 switch_to_thread (parent);
3600 ecs->event_thread = inferior_thread ();
3601 ecs->ptid = inferior_ptid;
3606 stop_stepping (ecs);
3609 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3610 goto process_event_stop_test;
3612 case TARGET_WAITKIND_VFORK_DONE:
3613 /* Done with the shared memory region. Re-insert breakpoints in
3614 the parent, and keep going. */
3617 fprintf_unfiltered (gdb_stdlog,
3618 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3620 if (!ptid_equal (ecs->ptid, inferior_ptid))
3621 context_switch (ecs->ptid);
3623 current_inferior ()->waiting_for_vfork_done = 0;
3624 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3625 /* This also takes care of reinserting breakpoints in the
3626 previously locked inferior. */
3630 case TARGET_WAITKIND_EXECD:
3632 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3634 if (!ptid_equal (ecs->ptid, inferior_ptid))
3635 context_switch (ecs->ptid);
3637 singlestep_breakpoints_inserted_p = 0;
3638 cancel_single_step_breakpoints ();
3640 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3642 /* Do whatever is necessary to the parent branch of the vfork. */
3643 handle_vfork_child_exec_or_exit (1);
3645 /* This causes the eventpoints and symbol table to be reset.
3646 Must do this now, before trying to determine whether to
3648 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3650 ecs->event_thread->control.stop_bpstat
3651 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3652 stop_pc, ecs->ptid, &ecs->ws);
3654 = (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3656 == BPSTAT_SIGNAL_NO);
3658 /* Note that this may be referenced from inside
3659 bpstat_stop_status above, through inferior_has_execd. */
3660 xfree (ecs->ws.value.execd_pathname);
3661 ecs->ws.value.execd_pathname = NULL;
3663 /* If no catchpoint triggered for this, then keep going. */
3664 if (ecs->random_signal)
3666 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3670 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3671 goto process_event_stop_test;
3673 /* Be careful not to try to gather much state about a thread
3674 that's in a syscall. It's frequently a losing proposition. */
3675 case TARGET_WAITKIND_SYSCALL_ENTRY:
3677 fprintf_unfiltered (gdb_stdlog,
3678 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3679 /* Getting the current syscall number. */
3680 if (handle_syscall_event (ecs) != 0)
3682 goto process_event_stop_test;
3684 /* Before examining the threads further, step this thread to
3685 get it entirely out of the syscall. (We get notice of the
3686 event when the thread is just on the verge of exiting a
3687 syscall. Stepping one instruction seems to get it back
3689 case TARGET_WAITKIND_SYSCALL_RETURN:
3691 fprintf_unfiltered (gdb_stdlog,
3692 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3693 if (handle_syscall_event (ecs) != 0)
3695 goto process_event_stop_test;
3697 case TARGET_WAITKIND_STOPPED:
3699 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3700 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
3703 case TARGET_WAITKIND_NO_HISTORY:
3705 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
3706 /* Reverse execution: target ran out of history info. */
3708 /* Pull the single step breakpoints out of the target. */
3709 if (singlestep_breakpoints_inserted_p)
3711 if (!ptid_equal (ecs->ptid, inferior_ptid))
3712 context_switch (ecs->ptid);
3713 remove_single_step_breakpoints ();
3714 singlestep_breakpoints_inserted_p = 0;
3716 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3717 print_no_history_reason ();
3718 stop_stepping (ecs);
3722 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3724 /* Do we need to clean up the state of a thread that has
3725 completed a displaced single-step? (Doing so usually affects
3726 the PC, so do it here, before we set stop_pc.) */
3727 displaced_step_fixup (ecs->ptid,
3728 ecs->event_thread->suspend.stop_signal);
3730 /* If we either finished a single-step or hit a breakpoint, but
3731 the user wanted this thread to be stopped, pretend we got a
3732 SIG0 (generic unsignaled stop). */
3734 if (ecs->event_thread->stop_requested
3735 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3736 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3739 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3743 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3744 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3745 struct cleanup *old_chain = save_inferior_ptid ();
3747 inferior_ptid = ecs->ptid;
3749 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3750 paddress (gdbarch, stop_pc));
3751 if (target_stopped_by_watchpoint ())
3755 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3757 if (target_stopped_data_address (¤t_target, &addr))
3758 fprintf_unfiltered (gdb_stdlog,
3759 "infrun: stopped data address = %s\n",
3760 paddress (gdbarch, addr));
3762 fprintf_unfiltered (gdb_stdlog,
3763 "infrun: (no data address available)\n");
3766 do_cleanups (old_chain);
3769 if (stepping_past_singlestep_breakpoint)
3771 gdb_assert (singlestep_breakpoints_inserted_p);
3772 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3773 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3775 stepping_past_singlestep_breakpoint = 0;
3777 /* We've either finished single-stepping past the single-step
3778 breakpoint, or stopped for some other reason. It would be nice if
3779 we could tell, but we can't reliably. */
3780 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3783 fprintf_unfiltered (gdb_stdlog,
3784 "infrun: stepping_past_"
3785 "singlestep_breakpoint\n");
3786 /* Pull the single step breakpoints out of the target. */
3787 if (!ptid_equal (ecs->ptid, inferior_ptid))
3788 context_switch (ecs->ptid);
3789 remove_single_step_breakpoints ();
3790 singlestep_breakpoints_inserted_p = 0;
3792 ecs->random_signal = 0;
3793 ecs->event_thread->control.trap_expected = 0;
3795 context_switch (saved_singlestep_ptid);
3796 if (deprecated_context_hook)
3797 deprecated_context_hook (pid_to_thread_id (saved_singlestep_ptid));
3799 resume (1, GDB_SIGNAL_0);
3800 prepare_to_wait (ecs);
3805 if (!ptid_equal (deferred_step_ptid, null_ptid))
3807 /* In non-stop mode, there's never a deferred_step_ptid set. */
3808 gdb_assert (!non_stop);
3810 /* If we stopped for some other reason than single-stepping, ignore
3811 the fact that we were supposed to switch back. */
3812 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3815 fprintf_unfiltered (gdb_stdlog,
3816 "infrun: handling deferred step\n");
3818 /* Pull the single step breakpoints out of the target. */
3819 if (singlestep_breakpoints_inserted_p)
3821 if (!ptid_equal (ecs->ptid, inferior_ptid))
3822 context_switch (ecs->ptid);
3823 remove_single_step_breakpoints ();
3824 singlestep_breakpoints_inserted_p = 0;
3827 ecs->event_thread->control.trap_expected = 0;
3829 context_switch (deferred_step_ptid);
3830 deferred_step_ptid = null_ptid;
3831 /* Suppress spurious "Switching to ..." message. */
3832 previous_inferior_ptid = inferior_ptid;
3834 resume (1, GDB_SIGNAL_0);
3835 prepare_to_wait (ecs);
3839 deferred_step_ptid = null_ptid;
3842 /* See if a thread hit a thread-specific breakpoint that was meant for
3843 another thread. If so, then step that thread past the breakpoint,
3846 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3848 int thread_hop_needed = 0;
3849 struct address_space *aspace =
3850 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3852 /* Check if a regular breakpoint has been hit before checking
3853 for a potential single step breakpoint. Otherwise, GDB will
3854 not see this breakpoint hit when stepping onto breakpoints. */
3855 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3857 ecs->random_signal = 0;
3858 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3859 thread_hop_needed = 1;
3861 else if (singlestep_breakpoints_inserted_p)
3863 /* We have not context switched yet, so this should be true
3864 no matter which thread hit the singlestep breakpoint. */
3865 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3867 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3869 target_pid_to_str (ecs->ptid));
3871 ecs->random_signal = 0;
3872 /* The call to in_thread_list is necessary because PTIDs sometimes
3873 change when we go from single-threaded to multi-threaded. If
3874 the singlestep_ptid is still in the list, assume that it is
3875 really different from ecs->ptid. */
3876 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3877 && in_thread_list (singlestep_ptid))
3879 /* If the PC of the thread we were trying to single-step
3880 has changed, discard this event (which we were going
3881 to ignore anyway), and pretend we saw that thread
3882 trap. This prevents us continuously moving the
3883 single-step breakpoint forward, one instruction at a
3884 time. If the PC has changed, then the thread we were
3885 trying to single-step has trapped or been signalled,
3886 but the event has not been reported to GDB yet.
3888 There might be some cases where this loses signal
3889 information, if a signal has arrived at exactly the
3890 same time that the PC changed, but this is the best
3891 we can do with the information available. Perhaps we
3892 should arrange to report all events for all threads
3893 when they stop, or to re-poll the remote looking for
3894 this particular thread (i.e. temporarily enable
3897 CORE_ADDR new_singlestep_pc
3898 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3900 if (new_singlestep_pc != singlestep_pc)
3902 enum gdb_signal stop_signal;
3905 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3906 " but expected thread advanced also\n");
3908 /* The current context still belongs to
3909 singlestep_ptid. Don't swap here, since that's
3910 the context we want to use. Just fudge our
3911 state and continue. */
3912 stop_signal = ecs->event_thread->suspend.stop_signal;
3913 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3914 ecs->ptid = singlestep_ptid;
3915 ecs->event_thread = find_thread_ptid (ecs->ptid);
3916 ecs->event_thread->suspend.stop_signal = stop_signal;
3917 stop_pc = new_singlestep_pc;
3922 fprintf_unfiltered (gdb_stdlog,
3923 "infrun: unexpected thread\n");
3925 thread_hop_needed = 1;
3926 stepping_past_singlestep_breakpoint = 1;
3927 saved_singlestep_ptid = singlestep_ptid;
3932 if (thread_hop_needed)
3934 struct regcache *thread_regcache;
3935 int remove_status = 0;
3938 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3940 /* Switch context before touching inferior memory, the
3941 previous thread may have exited. */
3942 if (!ptid_equal (inferior_ptid, ecs->ptid))
3943 context_switch (ecs->ptid);
3945 /* Saw a breakpoint, but it was hit by the wrong thread.
3948 if (singlestep_breakpoints_inserted_p)
3950 /* Pull the single step breakpoints out of the target. */
3951 remove_single_step_breakpoints ();
3952 singlestep_breakpoints_inserted_p = 0;
3955 /* If the arch can displace step, don't remove the
3957 thread_regcache = get_thread_regcache (ecs->ptid);
3958 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3959 remove_status = remove_breakpoints ();
3961 /* Did we fail to remove breakpoints? If so, try
3962 to set the PC past the bp. (There's at least
3963 one situation in which we can fail to remove
3964 the bp's: On HP-UX's that use ttrace, we can't
3965 change the address space of a vforking child
3966 process until the child exits (well, okay, not
3967 then either :-) or execs. */
3968 if (remove_status != 0)
3969 error (_("Cannot step over breakpoint hit in wrong thread"));
3974 /* Only need to require the next event from this
3975 thread in all-stop mode. */
3976 waiton_ptid = ecs->ptid;
3977 infwait_state = infwait_thread_hop_state;
3980 ecs->event_thread->stepping_over_breakpoint = 1;
3985 else if (singlestep_breakpoints_inserted_p)
3987 ecs->random_signal = 0;
3991 ecs->random_signal = 1;
3993 /* See if something interesting happened to the non-current thread. If
3994 so, then switch to that thread. */
3995 if (!ptid_equal (ecs->ptid, inferior_ptid))
3998 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
4000 context_switch (ecs->ptid);
4002 if (deprecated_context_hook)
4003 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
4006 /* At this point, get hold of the now-current thread's frame. */
4007 frame = get_current_frame ();
4008 gdbarch = get_frame_arch (frame);
4010 if (singlestep_breakpoints_inserted_p)
4012 /* Pull the single step breakpoints out of the target. */
4013 remove_single_step_breakpoints ();
4014 singlestep_breakpoints_inserted_p = 0;
4017 if (stepped_after_stopped_by_watchpoint)
4018 stopped_by_watchpoint = 0;
4020 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4022 /* If necessary, step over this watchpoint. We'll be back to display
4024 if (stopped_by_watchpoint
4025 && (target_have_steppable_watchpoint
4026 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4028 /* At this point, we are stopped at an instruction which has
4029 attempted to write to a piece of memory under control of
4030 a watchpoint. The instruction hasn't actually executed
4031 yet. If we were to evaluate the watchpoint expression
4032 now, we would get the old value, and therefore no change
4033 would seem to have occurred.
4035 In order to make watchpoints work `right', we really need
4036 to complete the memory write, and then evaluate the
4037 watchpoint expression. We do this by single-stepping the
4040 It may not be necessary to disable the watchpoint to stop over
4041 it. For example, the PA can (with some kernel cooperation)
4042 single step over a watchpoint without disabling the watchpoint.
4044 It is far more common to need to disable a watchpoint to step
4045 the inferior over it. If we have non-steppable watchpoints,
4046 we must disable the current watchpoint; it's simplest to
4047 disable all watchpoints and breakpoints. */
4050 if (!target_have_steppable_watchpoint)
4052 remove_breakpoints ();
4053 /* See comment in resume why we need to stop bypassing signals
4054 while breakpoints have been removed. */
4055 target_pass_signals (0, NULL);
4058 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
4059 target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0);
4060 waiton_ptid = ecs->ptid;
4061 if (target_have_steppable_watchpoint)
4062 infwait_state = infwait_step_watch_state;
4064 infwait_state = infwait_nonstep_watch_state;
4065 prepare_to_wait (ecs);
4069 clear_stop_func (ecs);
4070 ecs->event_thread->stepping_over_breakpoint = 0;
4071 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4072 ecs->event_thread->control.stop_step = 0;
4073 stop_print_frame = 1;
4074 ecs->random_signal = 0;
4075 stopped_by_random_signal = 0;
4077 /* Hide inlined functions starting here, unless we just performed stepi or
4078 nexti. After stepi and nexti, always show the innermost frame (not any
4079 inline function call sites). */
4080 if (ecs->event_thread->control.step_range_end != 1)
4082 struct address_space *aspace =
4083 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4085 /* skip_inline_frames is expensive, so we avoid it if we can
4086 determine that the address is one where functions cannot have
4087 been inlined. This improves performance with inferiors that
4088 load a lot of shared libraries, because the solib event
4089 breakpoint is defined as the address of a function (i.e. not
4090 inline). Note that we have to check the previous PC as well
4091 as the current one to catch cases when we have just
4092 single-stepped off a breakpoint prior to reinstating it.
4093 Note that we're assuming that the code we single-step to is
4094 not inline, but that's not definitive: there's nothing
4095 preventing the event breakpoint function from containing
4096 inlined code, and the single-step ending up there. If the
4097 user had set a breakpoint on that inlined code, the missing
4098 skip_inline_frames call would break things. Fortunately
4099 that's an extremely unlikely scenario. */
4100 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4101 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4102 && ecs->event_thread->control.trap_expected
4103 && pc_at_non_inline_function (aspace,
4104 ecs->event_thread->prev_pc,
4107 skip_inline_frames (ecs->ptid);
4109 /* Re-fetch current thread's frame in case that invalidated
4111 frame = get_current_frame ();
4112 gdbarch = get_frame_arch (frame);
4116 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4117 && ecs->event_thread->control.trap_expected
4118 && gdbarch_single_step_through_delay_p (gdbarch)
4119 && currently_stepping (ecs->event_thread))
4121 /* We're trying to step off a breakpoint. Turns out that we're
4122 also on an instruction that needs to be stepped multiple
4123 times before it's been fully executing. E.g., architectures
4124 with a delay slot. It needs to be stepped twice, once for
4125 the instruction and once for the delay slot. */
4126 int step_through_delay
4127 = gdbarch_single_step_through_delay (gdbarch, frame);
4129 if (debug_infrun && step_through_delay)
4130 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4131 if (ecs->event_thread->control.step_range_end == 0
4132 && step_through_delay)
4134 /* The user issued a continue when stopped at a breakpoint.
4135 Set up for another trap and get out of here. */
4136 ecs->event_thread->stepping_over_breakpoint = 1;
4140 else if (step_through_delay)
4142 /* The user issued a step when stopped at a breakpoint.
4143 Maybe we should stop, maybe we should not - the delay
4144 slot *might* correspond to a line of source. In any
4145 case, don't decide that here, just set
4146 ecs->stepping_over_breakpoint, making sure we
4147 single-step again before breakpoints are re-inserted. */
4148 ecs->event_thread->stepping_over_breakpoint = 1;
4152 /* Look at the cause of the stop, and decide what to do.
4153 The alternatives are:
4154 1) stop_stepping and return; to really stop and return to the debugger,
4155 2) keep_going and return to start up again
4156 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
4157 3) set ecs->random_signal to 1, and the decision between 1 and 2
4158 will be made according to the signal handling tables. */
4160 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4164 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4165 stop_print_frame = 0;
4166 stop_stepping (ecs);
4170 /* This is originated from start_remote(), start_inferior() and
4171 shared libraries hook functions. */
4172 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4175 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4176 stop_stepping (ecs);
4180 /* This originates from attach_command(). We need to overwrite
4181 the stop_signal here, because some kernels don't ignore a
4182 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4183 See more comments in inferior.h. On the other hand, if we
4184 get a non-SIGSTOP, report it to the user - assume the backend
4185 will handle the SIGSTOP if it should show up later.
4187 Also consider that the attach is complete when we see a
4188 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4189 target extended-remote report it instead of a SIGSTOP
4190 (e.g. gdbserver). We already rely on SIGTRAP being our
4191 signal, so this is no exception.
4193 Also consider that the attach is complete when we see a
4194 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4195 the target to stop all threads of the inferior, in case the
4196 low level attach operation doesn't stop them implicitly. If
4197 they weren't stopped implicitly, then the stub will report a
4198 GDB_SIGNAL_0, meaning: stopped for no particular reason
4199 other than GDB's request. */
4200 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4201 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4202 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4203 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4205 stop_stepping (ecs);
4206 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4210 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4211 handles this event. */
4212 ecs->event_thread->control.stop_bpstat
4213 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4214 stop_pc, ecs->ptid, &ecs->ws);
4216 /* Following in case break condition called a
4218 stop_print_frame = 1;
4220 /* This is where we handle "moribund" watchpoints. Unlike
4221 software breakpoints traps, hardware watchpoint traps are
4222 always distinguishable from random traps. If no high-level
4223 watchpoint is associated with the reported stop data address
4224 anymore, then the bpstat does not explain the signal ---
4225 simply make sure to ignore it if `stopped_by_watchpoint' is
4229 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4230 && (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4232 == BPSTAT_SIGNAL_NO)
4233 && stopped_by_watchpoint)
4234 fprintf_unfiltered (gdb_stdlog,
4235 "infrun: no user watchpoint explains "
4236 "watchpoint SIGTRAP, ignoring\n");
4238 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4239 at one stage in the past included checks for an inferior
4240 function call's call dummy's return breakpoint. The original
4241 comment, that went with the test, read:
4243 ``End of a stack dummy. Some systems (e.g. Sony news) give
4244 another signal besides SIGTRAP, so check here as well as
4247 If someone ever tries to get call dummys on a
4248 non-executable stack to work (where the target would stop
4249 with something like a SIGSEGV), then those tests might need
4250 to be re-instated. Given, however, that the tests were only
4251 enabled when momentary breakpoints were not being used, I
4252 suspect that it won't be the case.
4254 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4255 be necessary for call dummies on a non-executable stack on
4258 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4260 = !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4262 != BPSTAT_SIGNAL_NO)
4263 || stopped_by_watchpoint
4264 || ecs->event_thread->control.trap_expected
4265 || (ecs->event_thread->control.step_range_end
4266 && (ecs->event_thread->control.step_resume_breakpoint
4270 enum bpstat_signal_value sval;
4272 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4273 ecs->event_thread->suspend.stop_signal);
4274 ecs->random_signal = (sval == BPSTAT_SIGNAL_NO);
4276 if (sval == BPSTAT_SIGNAL_HIDE)
4277 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
4280 process_event_stop_test:
4282 /* Re-fetch current thread's frame in case we did a
4283 "goto process_event_stop_test" above. */
4284 frame = get_current_frame ();
4285 gdbarch = get_frame_arch (frame);
4287 /* For the program's own signals, act according to
4288 the signal handling tables. */
4290 if (ecs->random_signal)
4292 /* Signal not for debugging purposes. */
4294 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4297 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
4298 ecs->event_thread->suspend.stop_signal);
4300 stopped_by_random_signal = 1;
4302 if (signal_print[ecs->event_thread->suspend.stop_signal])
4305 target_terminal_ours_for_output ();
4306 print_signal_received_reason
4307 (ecs->event_thread->suspend.stop_signal);
4309 /* Always stop on signals if we're either just gaining control
4310 of the program, or the user explicitly requested this thread
4311 to remain stopped. */
4312 if (stop_soon != NO_STOP_QUIETLY
4313 || ecs->event_thread->stop_requested
4315 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4317 stop_stepping (ecs);
4320 /* If not going to stop, give terminal back
4321 if we took it away. */
4323 target_terminal_inferior ();
4325 /* Clear the signal if it should not be passed. */
4326 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4327 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4329 if (ecs->event_thread->prev_pc == stop_pc
4330 && ecs->event_thread->control.trap_expected
4331 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4333 /* We were just starting a new sequence, attempting to
4334 single-step off of a breakpoint and expecting a SIGTRAP.
4335 Instead this signal arrives. This signal will take us out
4336 of the stepping range so GDB needs to remember to, when
4337 the signal handler returns, resume stepping off that
4339 /* To simplify things, "continue" is forced to use the same
4340 code paths as single-step - set a breakpoint at the
4341 signal return address and then, once hit, step off that
4344 fprintf_unfiltered (gdb_stdlog,
4345 "infrun: signal arrived while stepping over "
4348 insert_hp_step_resume_breakpoint_at_frame (frame);
4349 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4350 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4351 ecs->event_thread->control.trap_expected = 0;
4356 if (ecs->event_thread->control.step_range_end != 0
4357 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4358 && pc_in_thread_step_range (stop_pc, ecs->event_thread)
4359 && frame_id_eq (get_stack_frame_id (frame),
4360 ecs->event_thread->control.step_stack_frame_id)
4361 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4363 /* The inferior is about to take a signal that will take it
4364 out of the single step range. Set a breakpoint at the
4365 current PC (which is presumably where the signal handler
4366 will eventually return) and then allow the inferior to
4369 Note that this is only needed for a signal delivered
4370 while in the single-step range. Nested signals aren't a
4371 problem as they eventually all return. */
4373 fprintf_unfiltered (gdb_stdlog,
4374 "infrun: signal may take us out of "
4375 "single-step range\n");
4377 insert_hp_step_resume_breakpoint_at_frame (frame);
4378 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4379 ecs->event_thread->control.trap_expected = 0;
4384 /* Note: step_resume_breakpoint may be non-NULL. This occures
4385 when either there's a nested signal, or when there's a
4386 pending signal enabled just as the signal handler returns
4387 (leaving the inferior at the step-resume-breakpoint without
4388 actually executing it). Either way continue until the
4389 breakpoint is really hit. */
4393 /* Handle cases caused by hitting a breakpoint. */
4395 CORE_ADDR jmp_buf_pc;
4396 struct bpstat_what what;
4398 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4400 if (what.call_dummy)
4402 stop_stack_dummy = what.call_dummy;
4405 /* If we hit an internal event that triggers symbol changes, the
4406 current frame will be invalidated within bpstat_what (e.g.,
4407 if we hit an internal solib event). Re-fetch it. */
4408 frame = get_current_frame ();
4409 gdbarch = get_frame_arch (frame);
4411 switch (what.main_action)
4413 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4414 /* If we hit the breakpoint at longjmp while stepping, we
4415 install a momentary breakpoint at the target of the
4419 fprintf_unfiltered (gdb_stdlog,
4420 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4422 ecs->event_thread->stepping_over_breakpoint = 1;
4424 if (what.is_longjmp)
4426 struct value *arg_value;
4428 /* If we set the longjmp breakpoint via a SystemTap
4429 probe, then use it to extract the arguments. The
4430 destination PC is the third argument to the
4432 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4434 jmp_buf_pc = value_as_address (arg_value);
4435 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4436 || !gdbarch_get_longjmp_target (gdbarch,
4437 frame, &jmp_buf_pc))
4440 fprintf_unfiltered (gdb_stdlog,
4441 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4442 "(!gdbarch_get_longjmp_target)\n");
4447 /* Insert a breakpoint at resume address. */
4448 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4451 check_exception_resume (ecs, frame);
4455 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4457 struct frame_info *init_frame;
4459 /* There are several cases to consider.
4461 1. The initiating frame no longer exists. In this case
4462 we must stop, because the exception or longjmp has gone
4465 2. The initiating frame exists, and is the same as the
4466 current frame. We stop, because the exception or
4467 longjmp has been caught.
4469 3. The initiating frame exists and is different from
4470 the current frame. This means the exception or longjmp
4471 has been caught beneath the initiating frame, so keep
4474 4. longjmp breakpoint has been placed just to protect
4475 against stale dummy frames and user is not interested
4476 in stopping around longjmps. */
4479 fprintf_unfiltered (gdb_stdlog,
4480 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4482 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4484 delete_exception_resume_breakpoint (ecs->event_thread);
4486 if (what.is_longjmp)
4488 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
4490 if (!frame_id_p (ecs->event_thread->initiating_frame))
4498 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4502 struct frame_id current_id
4503 = get_frame_id (get_current_frame ());
4504 if (frame_id_eq (current_id,
4505 ecs->event_thread->initiating_frame))
4507 /* Case 2. Fall through. */
4517 /* For Cases 1 and 2, remove the step-resume breakpoint,
4519 delete_step_resume_breakpoint (ecs->event_thread);
4521 ecs->event_thread->control.stop_step = 1;
4522 print_end_stepping_range_reason ();
4523 stop_stepping (ecs);
4527 case BPSTAT_WHAT_SINGLE:
4529 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4530 ecs->event_thread->stepping_over_breakpoint = 1;
4531 /* Still need to check other stuff, at least the case where
4532 we are stepping and step out of the right range. */
4535 case BPSTAT_WHAT_STEP_RESUME:
4537 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4539 delete_step_resume_breakpoint (ecs->event_thread);
4540 if (ecs->event_thread->control.proceed_to_finish
4541 && execution_direction == EXEC_REVERSE)
4543 struct thread_info *tp = ecs->event_thread;
4545 /* We are finishing a function in reverse, and just hit
4546 the step-resume breakpoint at the start address of
4547 the function, and we're almost there -- just need to
4548 back up by one more single-step, which should take us
4549 back to the function call. */
4550 tp->control.step_range_start = tp->control.step_range_end = 1;
4554 fill_in_stop_func (gdbarch, ecs);
4555 if (stop_pc == ecs->stop_func_start
4556 && execution_direction == EXEC_REVERSE)
4558 /* We are stepping over a function call in reverse, and
4559 just hit the step-resume breakpoint at the start
4560 address of the function. Go back to single-stepping,
4561 which should take us back to the function call. */
4562 ecs->event_thread->stepping_over_breakpoint = 1;
4568 case BPSTAT_WHAT_STOP_NOISY:
4570 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4571 stop_print_frame = 1;
4573 /* We are about to nuke the step_resume_breakpointt via the
4574 cleanup chain, so no need to worry about it here. */
4576 stop_stepping (ecs);
4579 case BPSTAT_WHAT_STOP_SILENT:
4581 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4582 stop_print_frame = 0;
4584 /* We are about to nuke the step_resume_breakpoin via the
4585 cleanup chain, so no need to worry about it here. */
4587 stop_stepping (ecs);
4590 case BPSTAT_WHAT_HP_STEP_RESUME:
4592 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4594 delete_step_resume_breakpoint (ecs->event_thread);
4595 if (ecs->event_thread->step_after_step_resume_breakpoint)
4597 /* Back when the step-resume breakpoint was inserted, we
4598 were trying to single-step off a breakpoint. Go back
4600 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4601 ecs->event_thread->stepping_over_breakpoint = 1;
4607 case BPSTAT_WHAT_KEEP_CHECKING:
4612 /* We come here if we hit a breakpoint but should not
4613 stop for it. Possibly we also were stepping
4614 and should stop for that. So fall through and
4615 test for stepping. But, if not stepping,
4618 /* In all-stop mode, if we're currently stepping but have stopped in
4619 some other thread, we need to switch back to the stepped thread. */
4622 struct thread_info *tp;
4624 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
4628 /* However, if the current thread is blocked on some internal
4629 breakpoint, and we simply need to step over that breakpoint
4630 to get it going again, do that first. */
4631 if ((ecs->event_thread->control.trap_expected
4632 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
4633 || ecs->event_thread->stepping_over_breakpoint)
4639 /* If the stepping thread exited, then don't try to switch
4640 back and resume it, which could fail in several different
4641 ways depending on the target. Instead, just keep going.
4643 We can find a stepping dead thread in the thread list in
4646 - The target supports thread exit events, and when the
4647 target tries to delete the thread from the thread list,
4648 inferior_ptid pointed at the exiting thread. In such
4649 case, calling delete_thread does not really remove the
4650 thread from the list; instead, the thread is left listed,
4651 with 'exited' state.
4653 - The target's debug interface does not support thread
4654 exit events, and so we have no idea whatsoever if the
4655 previously stepping thread is still alive. For that
4656 reason, we need to synchronously query the target
4658 if (is_exited (tp->ptid)
4659 || !target_thread_alive (tp->ptid))
4662 fprintf_unfiltered (gdb_stdlog,
4663 "infrun: not switching back to "
4664 "stepped thread, it has vanished\n");
4666 delete_thread (tp->ptid);
4671 /* Otherwise, we no longer expect a trap in the current thread.
4672 Clear the trap_expected flag before switching back -- this is
4673 what keep_going would do as well, if we called it. */
4674 ecs->event_thread->control.trap_expected = 0;
4677 fprintf_unfiltered (gdb_stdlog,
4678 "infrun: switching back to stepped thread\n");
4680 ecs->event_thread = tp;
4681 ecs->ptid = tp->ptid;
4682 context_switch (ecs->ptid);
4688 if (ecs->event_thread->control.step_resume_breakpoint)
4691 fprintf_unfiltered (gdb_stdlog,
4692 "infrun: step-resume breakpoint is inserted\n");
4694 /* Having a step-resume breakpoint overrides anything
4695 else having to do with stepping commands until
4696 that breakpoint is reached. */
4701 if (ecs->event_thread->control.step_range_end == 0)
4704 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4705 /* Likewise if we aren't even stepping. */
4710 /* Re-fetch current thread's frame in case the code above caused
4711 the frame cache to be re-initialized, making our FRAME variable
4712 a dangling pointer. */
4713 frame = get_current_frame ();
4714 gdbarch = get_frame_arch (frame);
4715 fill_in_stop_func (gdbarch, ecs);
4717 /* If stepping through a line, keep going if still within it.
4719 Note that step_range_end is the address of the first instruction
4720 beyond the step range, and NOT the address of the last instruction
4723 Note also that during reverse execution, we may be stepping
4724 through a function epilogue and therefore must detect when
4725 the current-frame changes in the middle of a line. */
4727 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
4728 && (execution_direction != EXEC_REVERSE
4729 || frame_id_eq (get_frame_id (frame),
4730 ecs->event_thread->control.step_frame_id)))
4734 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4735 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4736 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4738 /* Tentatively re-enable range stepping; `resume' disables it if
4739 necessary (e.g., if we're stepping over a breakpoint or we
4740 have software watchpoints). */
4741 ecs->event_thread->control.may_range_step = 1;
4743 /* When stepping backward, stop at beginning of line range
4744 (unless it's the function entry point, in which case
4745 keep going back to the call point). */
4746 if (stop_pc == ecs->event_thread->control.step_range_start
4747 && stop_pc != ecs->stop_func_start
4748 && execution_direction == EXEC_REVERSE)
4750 ecs->event_thread->control.stop_step = 1;
4751 print_end_stepping_range_reason ();
4752 stop_stepping (ecs);
4760 /* We stepped out of the stepping range. */
4762 /* If we are stepping at the source level and entered the runtime
4763 loader dynamic symbol resolution code...
4765 EXEC_FORWARD: we keep on single stepping until we exit the run
4766 time loader code and reach the callee's address.
4768 EXEC_REVERSE: we've already executed the callee (backward), and
4769 the runtime loader code is handled just like any other
4770 undebuggable function call. Now we need only keep stepping
4771 backward through the trampoline code, and that's handled further
4772 down, so there is nothing for us to do here. */
4774 if (execution_direction != EXEC_REVERSE
4775 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4776 && in_solib_dynsym_resolve_code (stop_pc))
4778 CORE_ADDR pc_after_resolver =
4779 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4782 fprintf_unfiltered (gdb_stdlog,
4783 "infrun: stepped into dynsym resolve code\n");
4785 if (pc_after_resolver)
4787 /* Set up a step-resume breakpoint at the address
4788 indicated by SKIP_SOLIB_RESOLVER. */
4789 struct symtab_and_line sr_sal;
4792 sr_sal.pc = pc_after_resolver;
4793 sr_sal.pspace = get_frame_program_space (frame);
4795 insert_step_resume_breakpoint_at_sal (gdbarch,
4796 sr_sal, null_frame_id);
4803 if (ecs->event_thread->control.step_range_end != 1
4804 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4805 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4806 && get_frame_type (frame) == SIGTRAMP_FRAME)
4809 fprintf_unfiltered (gdb_stdlog,
4810 "infrun: stepped into signal trampoline\n");
4811 /* The inferior, while doing a "step" or "next", has ended up in
4812 a signal trampoline (either by a signal being delivered or by
4813 the signal handler returning). Just single-step until the
4814 inferior leaves the trampoline (either by calling the handler
4820 /* If we're in the return path from a shared library trampoline,
4821 we want to proceed through the trampoline when stepping. */
4822 /* macro/2012-04-25: This needs to come before the subroutine
4823 call check below as on some targets return trampolines look
4824 like subroutine calls (MIPS16 return thunks). */
4825 if (gdbarch_in_solib_return_trampoline (gdbarch,
4826 stop_pc, ecs->stop_func_name)
4827 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4829 /* Determine where this trampoline returns. */
4830 CORE_ADDR real_stop_pc;
4832 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4835 fprintf_unfiltered (gdb_stdlog,
4836 "infrun: stepped into solib return tramp\n");
4838 /* Only proceed through if we know where it's going. */
4841 /* And put the step-breakpoint there and go until there. */
4842 struct symtab_and_line sr_sal;
4844 init_sal (&sr_sal); /* initialize to zeroes */
4845 sr_sal.pc = real_stop_pc;
4846 sr_sal.section = find_pc_overlay (sr_sal.pc);
4847 sr_sal.pspace = get_frame_program_space (frame);
4849 /* Do not specify what the fp should be when we stop since
4850 on some machines the prologue is where the new fp value
4852 insert_step_resume_breakpoint_at_sal (gdbarch,
4853 sr_sal, null_frame_id);
4855 /* Restart without fiddling with the step ranges or
4862 /* Check for subroutine calls. The check for the current frame
4863 equalling the step ID is not necessary - the check of the
4864 previous frame's ID is sufficient - but it is a common case and
4865 cheaper than checking the previous frame's ID.
4867 NOTE: frame_id_eq will never report two invalid frame IDs as
4868 being equal, so to get into this block, both the current and
4869 previous frame must have valid frame IDs. */
4870 /* The outer_frame_id check is a heuristic to detect stepping
4871 through startup code. If we step over an instruction which
4872 sets the stack pointer from an invalid value to a valid value,
4873 we may detect that as a subroutine call from the mythical
4874 "outermost" function. This could be fixed by marking
4875 outermost frames as !stack_p,code_p,special_p. Then the
4876 initial outermost frame, before sp was valid, would
4877 have code_addr == &_start. See the comment in frame_id_eq
4879 if (!frame_id_eq (get_stack_frame_id (frame),
4880 ecs->event_thread->control.step_stack_frame_id)
4881 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4882 ecs->event_thread->control.step_stack_frame_id)
4883 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
4885 || step_start_function != find_pc_function (stop_pc))))
4887 CORE_ADDR real_stop_pc;
4890 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4892 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
4893 || ((ecs->event_thread->control.step_range_end == 1)
4894 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4895 ecs->stop_func_start)))
4897 /* I presume that step_over_calls is only 0 when we're
4898 supposed to be stepping at the assembly language level
4899 ("stepi"). Just stop. */
4900 /* Also, maybe we just did a "nexti" inside a prolog, so we
4901 thought it was a subroutine call but it was not. Stop as
4903 /* And this works the same backward as frontward. MVS */
4904 ecs->event_thread->control.stop_step = 1;
4905 print_end_stepping_range_reason ();
4906 stop_stepping (ecs);
4910 /* Reverse stepping through solib trampolines. */
4912 if (execution_direction == EXEC_REVERSE
4913 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
4914 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4915 || (ecs->stop_func_start == 0
4916 && in_solib_dynsym_resolve_code (stop_pc))))
4918 /* Any solib trampoline code can be handled in reverse
4919 by simply continuing to single-step. We have already
4920 executed the solib function (backwards), and a few
4921 steps will take us back through the trampoline to the
4927 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4929 /* We're doing a "next".
4931 Normal (forward) execution: set a breakpoint at the
4932 callee's return address (the address at which the caller
4935 Reverse (backward) execution. set the step-resume
4936 breakpoint at the start of the function that we just
4937 stepped into (backwards), and continue to there. When we
4938 get there, we'll need to single-step back to the caller. */
4940 if (execution_direction == EXEC_REVERSE)
4942 /* If we're already at the start of the function, we've either
4943 just stepped backward into a single instruction function,
4944 or stepped back out of a signal handler to the first instruction
4945 of the function. Just keep going, which will single-step back
4947 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
4949 struct symtab_and_line sr_sal;
4951 /* Normal function call return (static or dynamic). */
4953 sr_sal.pc = ecs->stop_func_start;
4954 sr_sal.pspace = get_frame_program_space (frame);
4955 insert_step_resume_breakpoint_at_sal (gdbarch,
4956 sr_sal, null_frame_id);
4960 insert_step_resume_breakpoint_at_caller (frame);
4966 /* If we are in a function call trampoline (a stub between the
4967 calling routine and the real function), locate the real
4968 function. That's what tells us (a) whether we want to step
4969 into it at all, and (b) what prologue we want to run to the
4970 end of, if we do step into it. */
4971 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4972 if (real_stop_pc == 0)
4973 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4974 if (real_stop_pc != 0)
4975 ecs->stop_func_start = real_stop_pc;
4977 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4979 struct symtab_and_line sr_sal;
4982 sr_sal.pc = ecs->stop_func_start;
4983 sr_sal.pspace = get_frame_program_space (frame);
4985 insert_step_resume_breakpoint_at_sal (gdbarch,
4986 sr_sal, null_frame_id);
4991 /* If we have line number information for the function we are
4992 thinking of stepping into and the function isn't on the skip
4995 If there are several symtabs at that PC (e.g. with include
4996 files), just want to know whether *any* of them have line
4997 numbers. find_pc_line handles this. */
4999 struct symtab_and_line tmp_sal;
5001 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
5002 if (tmp_sal.line != 0
5003 && !function_name_is_marked_for_skip (ecs->stop_func_name,
5006 if (execution_direction == EXEC_REVERSE)
5007 handle_step_into_function_backward (gdbarch, ecs);
5009 handle_step_into_function (gdbarch, ecs);
5014 /* If we have no line number and the step-stop-if-no-debug is
5015 set, we stop the step so that the user has a chance to switch
5016 in assembly mode. */
5017 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5018 && step_stop_if_no_debug)
5020 ecs->event_thread->control.stop_step = 1;
5021 print_end_stepping_range_reason ();
5022 stop_stepping (ecs);
5026 if (execution_direction == EXEC_REVERSE)
5028 /* If we're already at the start of the function, we've either just
5029 stepped backward into a single instruction function without line
5030 number info, or stepped back out of a signal handler to the first
5031 instruction of the function without line number info. Just keep
5032 going, which will single-step back to the caller. */
5033 if (ecs->stop_func_start != stop_pc)
5035 /* Set a breakpoint at callee's start address.
5036 From there we can step once and be back in the caller. */
5037 struct symtab_and_line sr_sal;
5040 sr_sal.pc = ecs->stop_func_start;
5041 sr_sal.pspace = get_frame_program_space (frame);
5042 insert_step_resume_breakpoint_at_sal (gdbarch,
5043 sr_sal, null_frame_id);
5047 /* Set a breakpoint at callee's return address (the address
5048 at which the caller will resume). */
5049 insert_step_resume_breakpoint_at_caller (frame);
5055 /* Reverse stepping through solib trampolines. */
5057 if (execution_direction == EXEC_REVERSE
5058 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5060 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5061 || (ecs->stop_func_start == 0
5062 && in_solib_dynsym_resolve_code (stop_pc)))
5064 /* Any solib trampoline code can be handled in reverse
5065 by simply continuing to single-step. We have already
5066 executed the solib function (backwards), and a few
5067 steps will take us back through the trampoline to the
5072 else if (in_solib_dynsym_resolve_code (stop_pc))
5074 /* Stepped backward into the solib dynsym resolver.
5075 Set a breakpoint at its start and continue, then
5076 one more step will take us out. */
5077 struct symtab_and_line sr_sal;
5080 sr_sal.pc = ecs->stop_func_start;
5081 sr_sal.pspace = get_frame_program_space (frame);
5082 insert_step_resume_breakpoint_at_sal (gdbarch,
5083 sr_sal, null_frame_id);
5089 stop_pc_sal = find_pc_line (stop_pc, 0);
5091 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5092 the trampoline processing logic, however, there are some trampolines
5093 that have no names, so we should do trampoline handling first. */
5094 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5095 && ecs->stop_func_name == NULL
5096 && stop_pc_sal.line == 0)
5099 fprintf_unfiltered (gdb_stdlog,
5100 "infrun: stepped into undebuggable function\n");
5102 /* The inferior just stepped into, or returned to, an
5103 undebuggable function (where there is no debugging information
5104 and no line number corresponding to the address where the
5105 inferior stopped). Since we want to skip this kind of code,
5106 we keep going until the inferior returns from this
5107 function - unless the user has asked us not to (via
5108 set step-mode) or we no longer know how to get back
5109 to the call site. */
5110 if (step_stop_if_no_debug
5111 || !frame_id_p (frame_unwind_caller_id (frame)))
5113 /* If we have no line number and the step-stop-if-no-debug
5114 is set, we stop the step so that the user has a chance to
5115 switch in assembly mode. */
5116 ecs->event_thread->control.stop_step = 1;
5117 print_end_stepping_range_reason ();
5118 stop_stepping (ecs);
5123 /* Set a breakpoint at callee's return address (the address
5124 at which the caller will resume). */
5125 insert_step_resume_breakpoint_at_caller (frame);
5131 if (ecs->event_thread->control.step_range_end == 1)
5133 /* It is stepi or nexti. We always want to stop stepping after
5136 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5137 ecs->event_thread->control.stop_step = 1;
5138 print_end_stepping_range_reason ();
5139 stop_stepping (ecs);
5143 if (stop_pc_sal.line == 0)
5145 /* We have no line number information. That means to stop
5146 stepping (does this always happen right after one instruction,
5147 when we do "s" in a function with no line numbers,
5148 or can this happen as a result of a return or longjmp?). */
5150 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5151 ecs->event_thread->control.stop_step = 1;
5152 print_end_stepping_range_reason ();
5153 stop_stepping (ecs);
5157 /* Look for "calls" to inlined functions, part one. If the inline
5158 frame machinery detected some skipped call sites, we have entered
5159 a new inline function. */
5161 if (frame_id_eq (get_frame_id (get_current_frame ()),
5162 ecs->event_thread->control.step_frame_id)
5163 && inline_skipped_frames (ecs->ptid))
5165 struct symtab_and_line call_sal;
5168 fprintf_unfiltered (gdb_stdlog,
5169 "infrun: stepped into inlined function\n");
5171 find_frame_sal (get_current_frame (), &call_sal);
5173 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5175 /* For "step", we're going to stop. But if the call site
5176 for this inlined function is on the same source line as
5177 we were previously stepping, go down into the function
5178 first. Otherwise stop at the call site. */
5180 if (call_sal.line == ecs->event_thread->current_line
5181 && call_sal.symtab == ecs->event_thread->current_symtab)
5182 step_into_inline_frame (ecs->ptid);
5184 ecs->event_thread->control.stop_step = 1;
5185 print_end_stepping_range_reason ();
5186 stop_stepping (ecs);
5191 /* For "next", we should stop at the call site if it is on a
5192 different source line. Otherwise continue through the
5193 inlined function. */
5194 if (call_sal.line == ecs->event_thread->current_line
5195 && call_sal.symtab == ecs->event_thread->current_symtab)
5199 ecs->event_thread->control.stop_step = 1;
5200 print_end_stepping_range_reason ();
5201 stop_stepping (ecs);
5207 /* Look for "calls" to inlined functions, part two. If we are still
5208 in the same real function we were stepping through, but we have
5209 to go further up to find the exact frame ID, we are stepping
5210 through a more inlined call beyond its call site. */
5212 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5213 && !frame_id_eq (get_frame_id (get_current_frame ()),
5214 ecs->event_thread->control.step_frame_id)
5215 && stepped_in_from (get_current_frame (),
5216 ecs->event_thread->control.step_frame_id))
5219 fprintf_unfiltered (gdb_stdlog,
5220 "infrun: stepping through inlined function\n");
5222 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5226 ecs->event_thread->control.stop_step = 1;
5227 print_end_stepping_range_reason ();
5228 stop_stepping (ecs);
5233 if ((stop_pc == stop_pc_sal.pc)
5234 && (ecs->event_thread->current_line != stop_pc_sal.line
5235 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5237 /* We are at the start of a different line. So stop. Note that
5238 we don't stop if we step into the middle of a different line.
5239 That is said to make things like for (;;) statements work
5242 fprintf_unfiltered (gdb_stdlog,
5243 "infrun: stepped to a different line\n");
5244 ecs->event_thread->control.stop_step = 1;
5245 print_end_stepping_range_reason ();
5246 stop_stepping (ecs);
5250 /* We aren't done stepping.
5252 Optimize by setting the stepping range to the line.
5253 (We might not be in the original line, but if we entered a
5254 new line in mid-statement, we continue stepping. This makes
5255 things like for(;;) statements work better.) */
5257 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5258 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5259 ecs->event_thread->control.may_range_step = 1;
5260 set_step_info (frame, stop_pc_sal);
5263 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5267 /* Is thread TP in the middle of single-stepping? */
5270 currently_stepping (struct thread_info *tp)
5272 return ((tp->control.step_range_end
5273 && tp->control.step_resume_breakpoint == NULL)
5274 || tp->control.trap_expected
5275 || bpstat_should_step ());
5278 /* Returns true if any thread *but* the one passed in "data" is in the
5279 middle of stepping or of handling a "next". */
5282 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
5287 return (tp->control.step_range_end
5288 || tp->control.trap_expected);
5291 /* Inferior has stepped into a subroutine call with source code that
5292 we should not step over. Do step to the first line of code in
5296 handle_step_into_function (struct gdbarch *gdbarch,
5297 struct execution_control_state *ecs)
5300 struct symtab_and_line stop_func_sal, sr_sal;
5302 fill_in_stop_func (gdbarch, ecs);
5304 s = find_pc_symtab (stop_pc);
5305 if (s && s->language != language_asm)
5306 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5307 ecs->stop_func_start);
5309 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5310 /* Use the step_resume_break to step until the end of the prologue,
5311 even if that involves jumps (as it seems to on the vax under
5313 /* If the prologue ends in the middle of a source line, continue to
5314 the end of that source line (if it is still within the function).
5315 Otherwise, just go to end of prologue. */
5316 if (stop_func_sal.end
5317 && stop_func_sal.pc != ecs->stop_func_start
5318 && stop_func_sal.end < ecs->stop_func_end)
5319 ecs->stop_func_start = stop_func_sal.end;
5321 /* Architectures which require breakpoint adjustment might not be able
5322 to place a breakpoint at the computed address. If so, the test
5323 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5324 ecs->stop_func_start to an address at which a breakpoint may be
5325 legitimately placed.
5327 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5328 made, GDB will enter an infinite loop when stepping through
5329 optimized code consisting of VLIW instructions which contain
5330 subinstructions corresponding to different source lines. On
5331 FR-V, it's not permitted to place a breakpoint on any but the
5332 first subinstruction of a VLIW instruction. When a breakpoint is
5333 set, GDB will adjust the breakpoint address to the beginning of
5334 the VLIW instruction. Thus, we need to make the corresponding
5335 adjustment here when computing the stop address. */
5337 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5339 ecs->stop_func_start
5340 = gdbarch_adjust_breakpoint_address (gdbarch,
5341 ecs->stop_func_start);
5344 if (ecs->stop_func_start == stop_pc)
5346 /* We are already there: stop now. */
5347 ecs->event_thread->control.stop_step = 1;
5348 print_end_stepping_range_reason ();
5349 stop_stepping (ecs);
5354 /* Put the step-breakpoint there and go until there. */
5355 init_sal (&sr_sal); /* initialize to zeroes */
5356 sr_sal.pc = ecs->stop_func_start;
5357 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5358 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5360 /* Do not specify what the fp should be when we stop since on
5361 some machines the prologue is where the new fp value is
5363 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5365 /* And make sure stepping stops right away then. */
5366 ecs->event_thread->control.step_range_end
5367 = ecs->event_thread->control.step_range_start;
5372 /* Inferior has stepped backward into a subroutine call with source
5373 code that we should not step over. Do step to the beginning of the
5374 last line of code in it. */
5377 handle_step_into_function_backward (struct gdbarch *gdbarch,
5378 struct execution_control_state *ecs)
5381 struct symtab_and_line stop_func_sal;
5383 fill_in_stop_func (gdbarch, ecs);
5385 s = find_pc_symtab (stop_pc);
5386 if (s && s->language != language_asm)
5387 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5388 ecs->stop_func_start);
5390 stop_func_sal = find_pc_line (stop_pc, 0);
5392 /* OK, we're just going to keep stepping here. */
5393 if (stop_func_sal.pc == stop_pc)
5395 /* We're there already. Just stop stepping now. */
5396 ecs->event_thread->control.stop_step = 1;
5397 print_end_stepping_range_reason ();
5398 stop_stepping (ecs);
5402 /* Else just reset the step range and keep going.
5403 No step-resume breakpoint, they don't work for
5404 epilogues, which can have multiple entry paths. */
5405 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5406 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5412 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5413 This is used to both functions and to skip over code. */
5416 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5417 struct symtab_and_line sr_sal,
5418 struct frame_id sr_id,
5419 enum bptype sr_type)
5421 /* There should never be more than one step-resume or longjmp-resume
5422 breakpoint per thread, so we should never be setting a new
5423 step_resume_breakpoint when one is already active. */
5424 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5425 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5428 fprintf_unfiltered (gdb_stdlog,
5429 "infrun: inserting step-resume breakpoint at %s\n",
5430 paddress (gdbarch, sr_sal.pc));
5432 inferior_thread ()->control.step_resume_breakpoint
5433 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5437 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5438 struct symtab_and_line sr_sal,
5439 struct frame_id sr_id)
5441 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5446 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5447 This is used to skip a potential signal handler.
5449 This is called with the interrupted function's frame. The signal
5450 handler, when it returns, will resume the interrupted function at
5454 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5456 struct symtab_and_line sr_sal;
5457 struct gdbarch *gdbarch;
5459 gdb_assert (return_frame != NULL);
5460 init_sal (&sr_sal); /* initialize to zeros */
5462 gdbarch = get_frame_arch (return_frame);
5463 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5464 sr_sal.section = find_pc_overlay (sr_sal.pc);
5465 sr_sal.pspace = get_frame_program_space (return_frame);
5467 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5468 get_stack_frame_id (return_frame),
5472 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5473 is used to skip a function after stepping into it (for "next" or if
5474 the called function has no debugging information).
5476 The current function has almost always been reached by single
5477 stepping a call or return instruction. NEXT_FRAME belongs to the
5478 current function, and the breakpoint will be set at the caller's
5481 This is a separate function rather than reusing
5482 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5483 get_prev_frame, which may stop prematurely (see the implementation
5484 of frame_unwind_caller_id for an example). */
5487 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5489 struct symtab_and_line sr_sal;
5490 struct gdbarch *gdbarch;
5492 /* We shouldn't have gotten here if we don't know where the call site
5494 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5496 init_sal (&sr_sal); /* initialize to zeros */
5498 gdbarch = frame_unwind_caller_arch (next_frame);
5499 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5500 frame_unwind_caller_pc (next_frame));
5501 sr_sal.section = find_pc_overlay (sr_sal.pc);
5502 sr_sal.pspace = frame_unwind_program_space (next_frame);
5504 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5505 frame_unwind_caller_id (next_frame));
5508 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5509 new breakpoint at the target of a jmp_buf. The handling of
5510 longjmp-resume uses the same mechanisms used for handling
5511 "step-resume" breakpoints. */
5514 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5516 /* There should never be more than one longjmp-resume breakpoint per
5517 thread, so we should never be setting a new
5518 longjmp_resume_breakpoint when one is already active. */
5519 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
5522 fprintf_unfiltered (gdb_stdlog,
5523 "infrun: inserting longjmp-resume breakpoint at %s\n",
5524 paddress (gdbarch, pc));
5526 inferior_thread ()->control.exception_resume_breakpoint =
5527 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5530 /* Insert an exception resume breakpoint. TP is the thread throwing
5531 the exception. The block B is the block of the unwinder debug hook
5532 function. FRAME is the frame corresponding to the call to this
5533 function. SYM is the symbol of the function argument holding the
5534 target PC of the exception. */
5537 insert_exception_resume_breakpoint (struct thread_info *tp,
5539 struct frame_info *frame,
5542 volatile struct gdb_exception e;
5544 /* We want to ignore errors here. */
5545 TRY_CATCH (e, RETURN_MASK_ERROR)
5547 struct symbol *vsym;
5548 struct value *value;
5550 struct breakpoint *bp;
5552 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5553 value = read_var_value (vsym, frame);
5554 /* If the value was optimized out, revert to the old behavior. */
5555 if (! value_optimized_out (value))
5557 handler = value_as_address (value);
5560 fprintf_unfiltered (gdb_stdlog,
5561 "infrun: exception resume at %lx\n",
5562 (unsigned long) handler);
5564 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5565 handler, bp_exception_resume);
5567 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
5570 bp->thread = tp->num;
5571 inferior_thread ()->control.exception_resume_breakpoint = bp;
5576 /* A helper for check_exception_resume that sets an
5577 exception-breakpoint based on a SystemTap probe. */
5580 insert_exception_resume_from_probe (struct thread_info *tp,
5581 const struct probe *probe,
5582 struct frame_info *frame)
5584 struct value *arg_value;
5586 struct breakpoint *bp;
5588 arg_value = probe_safe_evaluate_at_pc (frame, 1);
5592 handler = value_as_address (arg_value);
5595 fprintf_unfiltered (gdb_stdlog,
5596 "infrun: exception resume at %s\n",
5597 paddress (get_objfile_arch (probe->objfile),
5600 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5601 handler, bp_exception_resume);
5602 bp->thread = tp->num;
5603 inferior_thread ()->control.exception_resume_breakpoint = bp;
5606 /* This is called when an exception has been intercepted. Check to
5607 see whether the exception's destination is of interest, and if so,
5608 set an exception resume breakpoint there. */
5611 check_exception_resume (struct execution_control_state *ecs,
5612 struct frame_info *frame)
5614 volatile struct gdb_exception e;
5615 const struct probe *probe;
5616 struct symbol *func;
5618 /* First see if this exception unwinding breakpoint was set via a
5619 SystemTap probe point. If so, the probe has two arguments: the
5620 CFA and the HANDLER. We ignore the CFA, extract the handler, and
5621 set a breakpoint there. */
5622 probe = find_probe_by_pc (get_frame_pc (frame));
5625 insert_exception_resume_from_probe (ecs->event_thread, probe, frame);
5629 func = get_frame_function (frame);
5633 TRY_CATCH (e, RETURN_MASK_ERROR)
5636 struct block_iterator iter;
5640 /* The exception breakpoint is a thread-specific breakpoint on
5641 the unwinder's debug hook, declared as:
5643 void _Unwind_DebugHook (void *cfa, void *handler);
5645 The CFA argument indicates the frame to which control is
5646 about to be transferred. HANDLER is the destination PC.
5648 We ignore the CFA and set a temporary breakpoint at HANDLER.
5649 This is not extremely efficient but it avoids issues in gdb
5650 with computing the DWARF CFA, and it also works even in weird
5651 cases such as throwing an exception from inside a signal
5654 b = SYMBOL_BLOCK_VALUE (func);
5655 ALL_BLOCK_SYMBOLS (b, iter, sym)
5657 if (!SYMBOL_IS_ARGUMENT (sym))
5664 insert_exception_resume_breakpoint (ecs->event_thread,
5673 stop_stepping (struct execution_control_state *ecs)
5676 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5678 /* Let callers know we don't want to wait for the inferior anymore. */
5679 ecs->wait_some_more = 0;
5682 /* This function handles various cases where we need to continue
5683 waiting for the inferior. */
5684 /* (Used to be the keep_going: label in the old wait_for_inferior). */
5687 keep_going (struct execution_control_state *ecs)
5689 /* Make sure normal_stop is called if we get a QUIT handled before
5691 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5693 /* Save the pc before execution, to compare with pc after stop. */
5694 ecs->event_thread->prev_pc
5695 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5697 /* If we did not do break;, it means we should keep running the
5698 inferior and not return to debugger. */
5700 if (ecs->event_thread->control.trap_expected
5701 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5703 /* We took a signal (which we are supposed to pass through to
5704 the inferior, else we'd not get here) and we haven't yet
5705 gotten our trap. Simply continue. */
5707 discard_cleanups (old_cleanups);
5708 resume (currently_stepping (ecs->event_thread),
5709 ecs->event_thread->suspend.stop_signal);
5713 /* Either the trap was not expected, but we are continuing
5714 anyway (the user asked that this signal be passed to the
5717 The signal was SIGTRAP, e.g. it was our signal, but we
5718 decided we should resume from it.
5720 We're going to run this baby now!
5722 Note that insert_breakpoints won't try to re-insert
5723 already inserted breakpoints. Therefore, we don't
5724 care if breakpoints were already inserted, or not. */
5726 if (ecs->event_thread->stepping_over_breakpoint)
5728 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5730 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5731 /* Since we can't do a displaced step, we have to remove
5732 the breakpoint while we step it. To keep things
5733 simple, we remove them all. */
5734 remove_breakpoints ();
5738 volatile struct gdb_exception e;
5740 /* Stop stepping when inserting breakpoints
5742 TRY_CATCH (e, RETURN_MASK_ERROR)
5744 insert_breakpoints ();
5748 exception_print (gdb_stderr, e);
5749 stop_stepping (ecs);
5754 ecs->event_thread->control.trap_expected
5755 = ecs->event_thread->stepping_over_breakpoint;
5757 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5758 specifies that such a signal should be delivered to the
5761 Typically, this would occure when a user is debugging a
5762 target monitor on a simulator: the target monitor sets a
5763 breakpoint; the simulator encounters this break-point and
5764 halts the simulation handing control to GDB; GDB, noteing
5765 that the break-point isn't valid, returns control back to the
5766 simulator; the simulator then delivers the hardware
5767 equivalent of a SIGNAL_TRAP to the program being debugged. */
5769 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5770 && !signal_program[ecs->event_thread->suspend.stop_signal])
5771 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5773 discard_cleanups (old_cleanups);
5774 resume (currently_stepping (ecs->event_thread),
5775 ecs->event_thread->suspend.stop_signal);
5778 prepare_to_wait (ecs);
5781 /* This function normally comes after a resume, before
5782 handle_inferior_event exits. It takes care of any last bits of
5783 housekeeping, and sets the all-important wait_some_more flag. */
5786 prepare_to_wait (struct execution_control_state *ecs)
5789 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5791 /* This is the old end of the while loop. Let everybody know we
5792 want to wait for the inferior some more and get called again
5794 ecs->wait_some_more = 1;
5797 /* Several print_*_reason functions to print why the inferior has stopped.
5798 We always print something when the inferior exits, or receives a signal.
5799 The rest of the cases are dealt with later on in normal_stop and
5800 print_it_typical. Ideally there should be a call to one of these
5801 print_*_reason functions functions from handle_inferior_event each time
5802 stop_stepping is called. */
5804 /* Print why the inferior has stopped.
5805 We are done with a step/next/si/ni command, print why the inferior has
5806 stopped. For now print nothing. Print a message only if not in the middle
5807 of doing a "step n" operation for n > 1. */
5810 print_end_stepping_range_reason (void)
5812 if ((!inferior_thread ()->step_multi
5813 || !inferior_thread ()->control.stop_step)
5814 && ui_out_is_mi_like_p (current_uiout))
5815 ui_out_field_string (current_uiout, "reason",
5816 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5819 /* The inferior was terminated by a signal, print why it stopped. */
5822 print_signal_exited_reason (enum gdb_signal siggnal)
5824 struct ui_out *uiout = current_uiout;
5826 annotate_signalled ();
5827 if (ui_out_is_mi_like_p (uiout))
5829 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5830 ui_out_text (uiout, "\nProgram terminated with signal ");
5831 annotate_signal_name ();
5832 ui_out_field_string (uiout, "signal-name",
5833 gdb_signal_to_name (siggnal));
5834 annotate_signal_name_end ();
5835 ui_out_text (uiout, ", ");
5836 annotate_signal_string ();
5837 ui_out_field_string (uiout, "signal-meaning",
5838 gdb_signal_to_string (siggnal));
5839 annotate_signal_string_end ();
5840 ui_out_text (uiout, ".\n");
5841 ui_out_text (uiout, "The program no longer exists.\n");
5844 /* The inferior program is finished, print why it stopped. */
5847 print_exited_reason (int exitstatus)
5849 struct inferior *inf = current_inferior ();
5850 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
5851 struct ui_out *uiout = current_uiout;
5853 annotate_exited (exitstatus);
5856 if (ui_out_is_mi_like_p (uiout))
5857 ui_out_field_string (uiout, "reason",
5858 async_reason_lookup (EXEC_ASYNC_EXITED));
5859 ui_out_text (uiout, "[Inferior ");
5860 ui_out_text (uiout, plongest (inf->num));
5861 ui_out_text (uiout, " (");
5862 ui_out_text (uiout, pidstr);
5863 ui_out_text (uiout, ") exited with code ");
5864 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
5865 ui_out_text (uiout, "]\n");
5869 if (ui_out_is_mi_like_p (uiout))
5871 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5872 ui_out_text (uiout, "[Inferior ");
5873 ui_out_text (uiout, plongest (inf->num));
5874 ui_out_text (uiout, " (");
5875 ui_out_text (uiout, pidstr);
5876 ui_out_text (uiout, ") exited normally]\n");
5878 /* Support the --return-child-result option. */
5879 return_child_result_value = exitstatus;
5882 /* Signal received, print why the inferior has stopped. The signal table
5883 tells us to print about it. */
5886 print_signal_received_reason (enum gdb_signal siggnal)
5888 struct ui_out *uiout = current_uiout;
5892 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5894 struct thread_info *t = inferior_thread ();
5896 ui_out_text (uiout, "\n[");
5897 ui_out_field_string (uiout, "thread-name",
5898 target_pid_to_str (t->ptid));
5899 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5900 ui_out_text (uiout, " stopped");
5904 ui_out_text (uiout, "\nProgram received signal ");
5905 annotate_signal_name ();
5906 if (ui_out_is_mi_like_p (uiout))
5908 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5909 ui_out_field_string (uiout, "signal-name",
5910 gdb_signal_to_name (siggnal));
5911 annotate_signal_name_end ();
5912 ui_out_text (uiout, ", ");
5913 annotate_signal_string ();
5914 ui_out_field_string (uiout, "signal-meaning",
5915 gdb_signal_to_string (siggnal));
5916 annotate_signal_string_end ();
5918 ui_out_text (uiout, ".\n");
5921 /* Reverse execution: target ran out of history info, print why the inferior
5925 print_no_history_reason (void)
5927 ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
5930 /* Here to return control to GDB when the inferior stops for real.
5931 Print appropriate messages, remove breakpoints, give terminal our modes.
5933 STOP_PRINT_FRAME nonzero means print the executing frame
5934 (pc, function, args, file, line number and line text).
5935 BREAKPOINTS_FAILED nonzero means stop was due to error
5936 attempting to insert breakpoints. */
5941 struct target_waitstatus last;
5943 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5945 get_last_target_status (&last_ptid, &last);
5947 /* If an exception is thrown from this point on, make sure to
5948 propagate GDB's knowledge of the executing state to the
5949 frontend/user running state. A QUIT is an easy exception to see
5950 here, so do this before any filtered output. */
5952 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5953 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5954 && last.kind != TARGET_WAITKIND_EXITED
5955 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5956 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5958 /* In non-stop mode, we don't want GDB to switch threads behind the
5959 user's back, to avoid races where the user is typing a command to
5960 apply to thread x, but GDB switches to thread y before the user
5961 finishes entering the command. */
5963 /* As with the notification of thread events, we want to delay
5964 notifying the user that we've switched thread context until
5965 the inferior actually stops.
5967 There's no point in saying anything if the inferior has exited.
5968 Note that SIGNALLED here means "exited with a signal", not
5969 "received a signal". */
5971 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
5972 && target_has_execution
5973 && last.kind != TARGET_WAITKIND_SIGNALLED
5974 && last.kind != TARGET_WAITKIND_EXITED
5975 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5977 target_terminal_ours_for_output ();
5978 printf_filtered (_("[Switching to %s]\n"),
5979 target_pid_to_str (inferior_ptid));
5980 annotate_thread_changed ();
5981 previous_inferior_ptid = inferior_ptid;
5984 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
5986 gdb_assert (sync_execution || !target_can_async_p ());
5988 target_terminal_ours_for_output ();
5989 printf_filtered (_("No unwaited-for children left.\n"));
5992 if (!breakpoints_always_inserted_mode () && target_has_execution)
5994 if (remove_breakpoints ())
5996 target_terminal_ours_for_output ();
5997 printf_filtered (_("Cannot remove breakpoints because "
5998 "program is no longer writable.\nFurther "
5999 "execution is probably impossible.\n"));
6003 /* If an auto-display called a function and that got a signal,
6004 delete that auto-display to avoid an infinite recursion. */
6006 if (stopped_by_random_signal)
6007 disable_current_display ();
6009 /* Don't print a message if in the middle of doing a "step n"
6010 operation for n > 1 */
6011 if (target_has_execution
6012 && last.kind != TARGET_WAITKIND_SIGNALLED
6013 && last.kind != TARGET_WAITKIND_EXITED
6014 && inferior_thread ()->step_multi
6015 && inferior_thread ()->control.stop_step)
6018 target_terminal_ours ();
6019 async_enable_stdin ();
6021 /* Set the current source location. This will also happen if we
6022 display the frame below, but the current SAL will be incorrect
6023 during a user hook-stop function. */
6024 if (has_stack_frames () && !stop_stack_dummy)
6025 set_current_sal_from_frame (get_current_frame (), 1);
6027 /* Let the user/frontend see the threads as stopped. */
6028 do_cleanups (old_chain);
6030 /* Look up the hook_stop and run it (CLI internally handles problem
6031 of stop_command's pre-hook not existing). */
6033 catch_errors (hook_stop_stub, stop_command,
6034 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6036 if (!has_stack_frames ())
6039 if (last.kind == TARGET_WAITKIND_SIGNALLED
6040 || last.kind == TARGET_WAITKIND_EXITED)
6043 /* Select innermost stack frame - i.e., current frame is frame 0,
6044 and current location is based on that.
6045 Don't do this on return from a stack dummy routine,
6046 or if the program has exited. */
6048 if (!stop_stack_dummy)
6050 select_frame (get_current_frame ());
6052 /* Print current location without a level number, if
6053 we have changed functions or hit a breakpoint.
6054 Print source line if we have one.
6055 bpstat_print() contains the logic deciding in detail
6056 what to print, based on the event(s) that just occurred. */
6058 /* If --batch-silent is enabled then there's no need to print the current
6059 source location, and to try risks causing an error message about
6060 missing source files. */
6061 if (stop_print_frame && !batch_silent)
6065 int do_frame_printing = 1;
6066 struct thread_info *tp = inferior_thread ();
6068 bpstat_ret = bpstat_print (tp->control.stop_bpstat, last.kind);
6072 /* FIXME: cagney/2002-12-01: Given that a frame ID does
6073 (or should) carry around the function and does (or
6074 should) use that when doing a frame comparison. */
6075 if (tp->control.stop_step
6076 && frame_id_eq (tp->control.step_frame_id,
6077 get_frame_id (get_current_frame ()))
6078 && step_start_function == find_pc_function (stop_pc))
6079 source_flag = SRC_LINE; /* Finished step, just
6080 print source line. */
6082 source_flag = SRC_AND_LOC; /* Print location and
6085 case PRINT_SRC_AND_LOC:
6086 source_flag = SRC_AND_LOC; /* Print location and
6089 case PRINT_SRC_ONLY:
6090 source_flag = SRC_LINE;
6093 source_flag = SRC_LINE; /* something bogus */
6094 do_frame_printing = 0;
6097 internal_error (__FILE__, __LINE__, _("Unknown value."));
6100 /* The behavior of this routine with respect to the source
6102 SRC_LINE: Print only source line
6103 LOCATION: Print only location
6104 SRC_AND_LOC: Print location and source line. */
6105 if (do_frame_printing)
6106 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
6108 /* Display the auto-display expressions. */
6113 /* Save the function value return registers, if we care.
6114 We might be about to restore their previous contents. */
6115 if (inferior_thread ()->control.proceed_to_finish
6116 && execution_direction != EXEC_REVERSE)
6118 /* This should not be necessary. */
6120 regcache_xfree (stop_registers);
6122 /* NB: The copy goes through to the target picking up the value of
6123 all the registers. */
6124 stop_registers = regcache_dup (get_current_regcache ());
6127 if (stop_stack_dummy == STOP_STACK_DUMMY)
6129 /* Pop the empty frame that contains the stack dummy.
6130 This also restores inferior state prior to the call
6131 (struct infcall_suspend_state). */
6132 struct frame_info *frame = get_current_frame ();
6134 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6136 /* frame_pop() calls reinit_frame_cache as the last thing it
6137 does which means there's currently no selected frame. We
6138 don't need to re-establish a selected frame if the dummy call
6139 returns normally, that will be done by
6140 restore_infcall_control_state. However, we do have to handle
6141 the case where the dummy call is returning after being
6142 stopped (e.g. the dummy call previously hit a breakpoint).
6143 We can't know which case we have so just always re-establish
6144 a selected frame here. */
6145 select_frame (get_current_frame ());
6149 annotate_stopped ();
6151 /* Suppress the stop observer if we're in the middle of:
6153 - a step n (n > 1), as there still more steps to be done.
6155 - a "finish" command, as the observer will be called in
6156 finish_command_continuation, so it can include the inferior
6157 function's return value.
6159 - calling an inferior function, as we pretend we inferior didn't
6160 run at all. The return value of the call is handled by the
6161 expression evaluator, through call_function_by_hand. */
6163 if (!target_has_execution
6164 || last.kind == TARGET_WAITKIND_SIGNALLED
6165 || last.kind == TARGET_WAITKIND_EXITED
6166 || last.kind == TARGET_WAITKIND_NO_RESUMED
6167 || (!(inferior_thread ()->step_multi
6168 && inferior_thread ()->control.stop_step)
6169 && !(inferior_thread ()->control.stop_bpstat
6170 && inferior_thread ()->control.proceed_to_finish)
6171 && !inferior_thread ()->control.in_infcall))
6173 if (!ptid_equal (inferior_ptid, null_ptid))
6174 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6177 observer_notify_normal_stop (NULL, stop_print_frame);
6180 if (target_has_execution)
6182 if (last.kind != TARGET_WAITKIND_SIGNALLED
6183 && last.kind != TARGET_WAITKIND_EXITED)
6184 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6185 Delete any breakpoint that is to be deleted at the next stop. */
6186 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6189 /* Try to get rid of automatically added inferiors that are no
6190 longer needed. Keeping those around slows down things linearly.
6191 Note that this never removes the current inferior. */
6196 hook_stop_stub (void *cmd)
6198 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6203 signal_stop_state (int signo)
6205 return signal_stop[signo];
6209 signal_print_state (int signo)
6211 return signal_print[signo];
6215 signal_pass_state (int signo)
6217 return signal_program[signo];
6221 signal_cache_update (int signo)
6225 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6226 signal_cache_update (signo);
6231 signal_pass[signo] = (signal_stop[signo] == 0
6232 && signal_print[signo] == 0
6233 && signal_program[signo] == 1
6234 && signal_catch[signo] == 0);
6238 signal_stop_update (int signo, int state)
6240 int ret = signal_stop[signo];
6242 signal_stop[signo] = state;
6243 signal_cache_update (signo);
6248 signal_print_update (int signo, int state)
6250 int ret = signal_print[signo];
6252 signal_print[signo] = state;
6253 signal_cache_update (signo);
6258 signal_pass_update (int signo, int state)
6260 int ret = signal_program[signo];
6262 signal_program[signo] = state;
6263 signal_cache_update (signo);
6267 /* Update the global 'signal_catch' from INFO and notify the
6271 signal_catch_update (const unsigned int *info)
6275 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6276 signal_catch[i] = info[i] > 0;
6277 signal_cache_update (-1);
6278 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6282 sig_print_header (void)
6284 printf_filtered (_("Signal Stop\tPrint\tPass "
6285 "to program\tDescription\n"));
6289 sig_print_info (enum gdb_signal oursig)
6291 const char *name = gdb_signal_to_name (oursig);
6292 int name_padding = 13 - strlen (name);
6294 if (name_padding <= 0)
6297 printf_filtered ("%s", name);
6298 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6299 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6300 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6301 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6302 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6305 /* Specify how various signals in the inferior should be handled. */
6308 handle_command (char *args, int from_tty)
6311 int digits, wordlen;
6312 int sigfirst, signum, siglast;
6313 enum gdb_signal oursig;
6316 unsigned char *sigs;
6317 struct cleanup *old_chain;
6321 error_no_arg (_("signal to handle"));
6324 /* Allocate and zero an array of flags for which signals to handle. */
6326 nsigs = (int) GDB_SIGNAL_LAST;
6327 sigs = (unsigned char *) alloca (nsigs);
6328 memset (sigs, 0, nsigs);
6330 /* Break the command line up into args. */
6332 argv = gdb_buildargv (args);
6333 old_chain = make_cleanup_freeargv (argv);
6335 /* Walk through the args, looking for signal oursigs, signal names, and
6336 actions. Signal numbers and signal names may be interspersed with
6337 actions, with the actions being performed for all signals cumulatively
6338 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6340 while (*argv != NULL)
6342 wordlen = strlen (*argv);
6343 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6347 sigfirst = siglast = -1;
6349 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6351 /* Apply action to all signals except those used by the
6352 debugger. Silently skip those. */
6355 siglast = nsigs - 1;
6357 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6359 SET_SIGS (nsigs, sigs, signal_stop);
6360 SET_SIGS (nsigs, sigs, signal_print);
6362 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6364 UNSET_SIGS (nsigs, sigs, signal_program);
6366 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6368 SET_SIGS (nsigs, sigs, signal_print);
6370 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6372 SET_SIGS (nsigs, sigs, signal_program);
6374 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6376 UNSET_SIGS (nsigs, sigs, signal_stop);
6378 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6380 SET_SIGS (nsigs, sigs, signal_program);
6382 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6384 UNSET_SIGS (nsigs, sigs, signal_print);
6385 UNSET_SIGS (nsigs, sigs, signal_stop);
6387 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6389 UNSET_SIGS (nsigs, sigs, signal_program);
6391 else if (digits > 0)
6393 /* It is numeric. The numeric signal refers to our own
6394 internal signal numbering from target.h, not to host/target
6395 signal number. This is a feature; users really should be
6396 using symbolic names anyway, and the common ones like
6397 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6399 sigfirst = siglast = (int)
6400 gdb_signal_from_command (atoi (*argv));
6401 if ((*argv)[digits] == '-')
6404 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6406 if (sigfirst > siglast)
6408 /* Bet he didn't figure we'd think of this case... */
6416 oursig = gdb_signal_from_name (*argv);
6417 if (oursig != GDB_SIGNAL_UNKNOWN)
6419 sigfirst = siglast = (int) oursig;
6423 /* Not a number and not a recognized flag word => complain. */
6424 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6428 /* If any signal numbers or symbol names were found, set flags for
6429 which signals to apply actions to. */
6431 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6433 switch ((enum gdb_signal) signum)
6435 case GDB_SIGNAL_TRAP:
6436 case GDB_SIGNAL_INT:
6437 if (!allsigs && !sigs[signum])
6439 if (query (_("%s is used by the debugger.\n\
6440 Are you sure you want to change it? "),
6441 gdb_signal_to_name ((enum gdb_signal) signum)))
6447 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6448 gdb_flush (gdb_stdout);
6453 case GDB_SIGNAL_DEFAULT:
6454 case GDB_SIGNAL_UNKNOWN:
6455 /* Make sure that "all" doesn't print these. */
6466 for (signum = 0; signum < nsigs; signum++)
6469 signal_cache_update (-1);
6470 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6471 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
6475 /* Show the results. */
6476 sig_print_header ();
6477 for (; signum < nsigs; signum++)
6479 sig_print_info (signum);
6485 do_cleanups (old_chain);
6488 /* Complete the "handle" command. */
6490 static VEC (char_ptr) *
6491 handle_completer (struct cmd_list_element *ignore,
6492 const char *text, const char *word)
6494 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
6495 static const char * const keywords[] =
6509 vec_signals = signal_completer (ignore, text, word);
6510 vec_keywords = complete_on_enum (keywords, word, word);
6512 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
6513 VEC_free (char_ptr, vec_signals);
6514 VEC_free (char_ptr, vec_keywords);
6519 xdb_handle_command (char *args, int from_tty)
6522 struct cleanup *old_chain;
6525 error_no_arg (_("xdb command"));
6527 /* Break the command line up into args. */
6529 argv = gdb_buildargv (args);
6530 old_chain = make_cleanup_freeargv (argv);
6531 if (argv[1] != (char *) NULL)
6536 bufLen = strlen (argv[0]) + 20;
6537 argBuf = (char *) xmalloc (bufLen);
6541 enum gdb_signal oursig;
6543 oursig = gdb_signal_from_name (argv[0]);
6544 memset (argBuf, 0, bufLen);
6545 if (strcmp (argv[1], "Q") == 0)
6546 sprintf (argBuf, "%s %s", argv[0], "noprint");
6549 if (strcmp (argv[1], "s") == 0)
6551 if (!signal_stop[oursig])
6552 sprintf (argBuf, "%s %s", argv[0], "stop");
6554 sprintf (argBuf, "%s %s", argv[0], "nostop");
6556 else if (strcmp (argv[1], "i") == 0)
6558 if (!signal_program[oursig])
6559 sprintf (argBuf, "%s %s", argv[0], "pass");
6561 sprintf (argBuf, "%s %s", argv[0], "nopass");
6563 else if (strcmp (argv[1], "r") == 0)
6565 if (!signal_print[oursig])
6566 sprintf (argBuf, "%s %s", argv[0], "print");
6568 sprintf (argBuf, "%s %s", argv[0], "noprint");
6574 handle_command (argBuf, from_tty);
6576 printf_filtered (_("Invalid signal handling flag.\n"));
6581 do_cleanups (old_chain);
6585 gdb_signal_from_command (int num)
6587 if (num >= 1 && num <= 15)
6588 return (enum gdb_signal) num;
6589 error (_("Only signals 1-15 are valid as numeric signals.\n\
6590 Use \"info signals\" for a list of symbolic signals."));
6593 /* Print current contents of the tables set by the handle command.
6594 It is possible we should just be printing signals actually used
6595 by the current target (but for things to work right when switching
6596 targets, all signals should be in the signal tables). */
6599 signals_info (char *signum_exp, int from_tty)
6601 enum gdb_signal oursig;
6603 sig_print_header ();
6607 /* First see if this is a symbol name. */
6608 oursig = gdb_signal_from_name (signum_exp);
6609 if (oursig == GDB_SIGNAL_UNKNOWN)
6611 /* No, try numeric. */
6613 gdb_signal_from_command (parse_and_eval_long (signum_exp));
6615 sig_print_info (oursig);
6619 printf_filtered ("\n");
6620 /* These ugly casts brought to you by the native VAX compiler. */
6621 for (oursig = GDB_SIGNAL_FIRST;
6622 (int) oursig < (int) GDB_SIGNAL_LAST;
6623 oursig = (enum gdb_signal) ((int) oursig + 1))
6627 if (oursig != GDB_SIGNAL_UNKNOWN
6628 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
6629 sig_print_info (oursig);
6632 printf_filtered (_("\nUse the \"handle\" command "
6633 "to change these tables.\n"));
6636 /* Check if it makes sense to read $_siginfo from the current thread
6637 at this point. If not, throw an error. */
6640 validate_siginfo_access (void)
6642 /* No current inferior, no siginfo. */
6643 if (ptid_equal (inferior_ptid, null_ptid))
6644 error (_("No thread selected."));
6646 /* Don't try to read from a dead thread. */
6647 if (is_exited (inferior_ptid))
6648 error (_("The current thread has terminated"));
6650 /* ... or from a spinning thread. */
6651 if (is_running (inferior_ptid))
6652 error (_("Selected thread is running."));
6655 /* The $_siginfo convenience variable is a bit special. We don't know
6656 for sure the type of the value until we actually have a chance to
6657 fetch the data. The type can change depending on gdbarch, so it is
6658 also dependent on which thread you have selected.
6660 1. making $_siginfo be an internalvar that creates a new value on
6663 2. making the value of $_siginfo be an lval_computed value. */
6665 /* This function implements the lval_computed support for reading a
6669 siginfo_value_read (struct value *v)
6671 LONGEST transferred;
6673 validate_siginfo_access ();
6676 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
6678 value_contents_all_raw (v),
6680 TYPE_LENGTH (value_type (v)));
6682 if (transferred != TYPE_LENGTH (value_type (v)))
6683 error (_("Unable to read siginfo"));
6686 /* This function implements the lval_computed support for writing a
6690 siginfo_value_write (struct value *v, struct value *fromval)
6692 LONGEST transferred;
6694 validate_siginfo_access ();
6696 transferred = target_write (¤t_target,
6697 TARGET_OBJECT_SIGNAL_INFO,
6699 value_contents_all_raw (fromval),
6701 TYPE_LENGTH (value_type (fromval)));
6703 if (transferred != TYPE_LENGTH (value_type (fromval)))
6704 error (_("Unable to write siginfo"));
6707 static const struct lval_funcs siginfo_value_funcs =
6713 /* Return a new value with the correct type for the siginfo object of
6714 the current thread using architecture GDBARCH. Return a void value
6715 if there's no object available. */
6717 static struct value *
6718 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
6721 if (target_has_stack
6722 && !ptid_equal (inferior_ptid, null_ptid)
6723 && gdbarch_get_siginfo_type_p (gdbarch))
6725 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6727 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
6730 return allocate_value (builtin_type (gdbarch)->builtin_void);
6734 /* infcall_suspend_state contains state about the program itself like its
6735 registers and any signal it received when it last stopped.
6736 This state must be restored regardless of how the inferior function call
6737 ends (either successfully, or after it hits a breakpoint or signal)
6738 if the program is to properly continue where it left off. */
6740 struct infcall_suspend_state
6742 struct thread_suspend_state thread_suspend;
6743 #if 0 /* Currently unused and empty structures are not valid C. */
6744 struct inferior_suspend_state inferior_suspend;
6749 struct regcache *registers;
6751 /* Format of SIGINFO_DATA or NULL if it is not present. */
6752 struct gdbarch *siginfo_gdbarch;
6754 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6755 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6756 content would be invalid. */
6757 gdb_byte *siginfo_data;
6760 struct infcall_suspend_state *
6761 save_infcall_suspend_state (void)
6763 struct infcall_suspend_state *inf_state;
6764 struct thread_info *tp = inferior_thread ();
6766 struct inferior *inf = current_inferior ();
6768 struct regcache *regcache = get_current_regcache ();
6769 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6770 gdb_byte *siginfo_data = NULL;
6772 if (gdbarch_get_siginfo_type_p (gdbarch))
6774 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6775 size_t len = TYPE_LENGTH (type);
6776 struct cleanup *back_to;
6778 siginfo_data = xmalloc (len);
6779 back_to = make_cleanup (xfree, siginfo_data);
6781 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6782 siginfo_data, 0, len) == len)
6783 discard_cleanups (back_to);
6786 /* Errors ignored. */
6787 do_cleanups (back_to);
6788 siginfo_data = NULL;
6792 inf_state = XZALLOC (struct infcall_suspend_state);
6796 inf_state->siginfo_gdbarch = gdbarch;
6797 inf_state->siginfo_data = siginfo_data;
6800 inf_state->thread_suspend = tp->suspend;
6801 #if 0 /* Currently unused and empty structures are not valid C. */
6802 inf_state->inferior_suspend = inf->suspend;
6805 /* run_inferior_call will not use the signal due to its `proceed' call with
6806 GDB_SIGNAL_0 anyway. */
6807 tp->suspend.stop_signal = GDB_SIGNAL_0;
6809 inf_state->stop_pc = stop_pc;
6811 inf_state->registers = regcache_dup (regcache);
6816 /* Restore inferior session state to INF_STATE. */
6819 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6821 struct thread_info *tp = inferior_thread ();
6823 struct inferior *inf = current_inferior ();
6825 struct regcache *regcache = get_current_regcache ();
6826 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6828 tp->suspend = inf_state->thread_suspend;
6829 #if 0 /* Currently unused and empty structures are not valid C. */
6830 inf->suspend = inf_state->inferior_suspend;
6833 stop_pc = inf_state->stop_pc;
6835 if (inf_state->siginfo_gdbarch == gdbarch)
6837 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6839 /* Errors ignored. */
6840 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6841 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
6844 /* The inferior can be gone if the user types "print exit(0)"
6845 (and perhaps other times). */
6846 if (target_has_execution)
6847 /* NB: The register write goes through to the target. */
6848 regcache_cpy (regcache, inf_state->registers);
6850 discard_infcall_suspend_state (inf_state);
6854 do_restore_infcall_suspend_state_cleanup (void *state)
6856 restore_infcall_suspend_state (state);
6860 make_cleanup_restore_infcall_suspend_state
6861 (struct infcall_suspend_state *inf_state)
6863 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
6867 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6869 regcache_xfree (inf_state->registers);
6870 xfree (inf_state->siginfo_data);
6875 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
6877 return inf_state->registers;
6880 /* infcall_control_state contains state regarding gdb's control of the
6881 inferior itself like stepping control. It also contains session state like
6882 the user's currently selected frame. */
6884 struct infcall_control_state
6886 struct thread_control_state thread_control;
6887 struct inferior_control_state inferior_control;
6890 enum stop_stack_kind stop_stack_dummy;
6891 int stopped_by_random_signal;
6892 int stop_after_trap;
6894 /* ID if the selected frame when the inferior function call was made. */
6895 struct frame_id selected_frame_id;
6898 /* Save all of the information associated with the inferior<==>gdb
6901 struct infcall_control_state *
6902 save_infcall_control_state (void)
6904 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
6905 struct thread_info *tp = inferior_thread ();
6906 struct inferior *inf = current_inferior ();
6908 inf_status->thread_control = tp->control;
6909 inf_status->inferior_control = inf->control;
6911 tp->control.step_resume_breakpoint = NULL;
6912 tp->control.exception_resume_breakpoint = NULL;
6914 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6915 chain. If caller's caller is walking the chain, they'll be happier if we
6916 hand them back the original chain when restore_infcall_control_state is
6918 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
6921 inf_status->stop_stack_dummy = stop_stack_dummy;
6922 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6923 inf_status->stop_after_trap = stop_after_trap;
6925 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6931 restore_selected_frame (void *args)
6933 struct frame_id *fid = (struct frame_id *) args;
6934 struct frame_info *frame;
6936 frame = frame_find_by_id (*fid);
6938 /* If inf_status->selected_frame_id is NULL, there was no previously
6942 warning (_("Unable to restore previously selected frame."));
6946 select_frame (frame);
6951 /* Restore inferior session state to INF_STATUS. */
6954 restore_infcall_control_state (struct infcall_control_state *inf_status)
6956 struct thread_info *tp = inferior_thread ();
6957 struct inferior *inf = current_inferior ();
6959 if (tp->control.step_resume_breakpoint)
6960 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
6962 if (tp->control.exception_resume_breakpoint)
6963 tp->control.exception_resume_breakpoint->disposition
6964 = disp_del_at_next_stop;
6966 /* Handle the bpstat_copy of the chain. */
6967 bpstat_clear (&tp->control.stop_bpstat);
6969 tp->control = inf_status->thread_control;
6970 inf->control = inf_status->inferior_control;
6973 stop_stack_dummy = inf_status->stop_stack_dummy;
6974 stopped_by_random_signal = inf_status->stopped_by_random_signal;
6975 stop_after_trap = inf_status->stop_after_trap;
6977 if (target_has_stack)
6979 /* The point of catch_errors is that if the stack is clobbered,
6980 walking the stack might encounter a garbage pointer and
6981 error() trying to dereference it. */
6983 (restore_selected_frame, &inf_status->selected_frame_id,
6984 "Unable to restore previously selected frame:\n",
6985 RETURN_MASK_ERROR) == 0)
6986 /* Error in restoring the selected frame. Select the innermost
6988 select_frame (get_current_frame ());
6995 do_restore_infcall_control_state_cleanup (void *sts)
6997 restore_infcall_control_state (sts);
7001 make_cleanup_restore_infcall_control_state
7002 (struct infcall_control_state *inf_status)
7004 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
7008 discard_infcall_control_state (struct infcall_control_state *inf_status)
7010 if (inf_status->thread_control.step_resume_breakpoint)
7011 inf_status->thread_control.step_resume_breakpoint->disposition
7012 = disp_del_at_next_stop;
7014 if (inf_status->thread_control.exception_resume_breakpoint)
7015 inf_status->thread_control.exception_resume_breakpoint->disposition
7016 = disp_del_at_next_stop;
7018 /* See save_infcall_control_state for info on stop_bpstat. */
7019 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7025 ptid_match (ptid_t ptid, ptid_t filter)
7027 if (ptid_equal (filter, minus_one_ptid))
7029 if (ptid_is_pid (filter)
7030 && ptid_get_pid (ptid) == ptid_get_pid (filter))
7032 else if (ptid_equal (ptid, filter))
7038 /* restore_inferior_ptid() will be used by the cleanup machinery
7039 to restore the inferior_ptid value saved in a call to
7040 save_inferior_ptid(). */
7043 restore_inferior_ptid (void *arg)
7045 ptid_t *saved_ptid_ptr = arg;
7047 inferior_ptid = *saved_ptid_ptr;
7051 /* Save the value of inferior_ptid so that it may be restored by a
7052 later call to do_cleanups(). Returns the struct cleanup pointer
7053 needed for later doing the cleanup. */
7056 save_inferior_ptid (void)
7058 ptid_t *saved_ptid_ptr;
7060 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7061 *saved_ptid_ptr = inferior_ptid;
7062 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7066 /* User interface for reverse debugging:
7067 Set exec-direction / show exec-direction commands
7068 (returns error unless target implements to_set_exec_direction method). */
7070 int execution_direction = EXEC_FORWARD;
7071 static const char exec_forward[] = "forward";
7072 static const char exec_reverse[] = "reverse";
7073 static const char *exec_direction = exec_forward;
7074 static const char *const exec_direction_names[] = {
7081 set_exec_direction_func (char *args, int from_tty,
7082 struct cmd_list_element *cmd)
7084 if (target_can_execute_reverse)
7086 if (!strcmp (exec_direction, exec_forward))
7087 execution_direction = EXEC_FORWARD;
7088 else if (!strcmp (exec_direction, exec_reverse))
7089 execution_direction = EXEC_REVERSE;
7093 exec_direction = exec_forward;
7094 error (_("Target does not support this operation."));
7099 show_exec_direction_func (struct ui_file *out, int from_tty,
7100 struct cmd_list_element *cmd, const char *value)
7102 switch (execution_direction) {
7104 fprintf_filtered (out, _("Forward.\n"));
7107 fprintf_filtered (out, _("Reverse.\n"));
7110 internal_error (__FILE__, __LINE__,
7111 _("bogus execution_direction value: %d"),
7112 (int) execution_direction);
7117 show_schedule_multiple (struct ui_file *file, int from_tty,
7118 struct cmd_list_element *c, const char *value)
7120 fprintf_filtered (file, _("Resuming the execution of threads "
7121 "of all processes is %s.\n"), value);
7124 /* Implementation of `siginfo' variable. */
7126 static const struct internalvar_funcs siginfo_funcs =
7134 _initialize_infrun (void)
7138 struct cmd_list_element *c;
7140 add_info ("signals", signals_info, _("\
7141 What debugger does when program gets various signals.\n\
7142 Specify a signal as argument to print info on that signal only."));
7143 add_info_alias ("handle", "signals", 0);
7145 c = add_com ("handle", class_run, handle_command, _("\
7146 Specify how to handle signals.\n\
7147 Usage: handle SIGNAL [ACTIONS]\n\
7148 Args are signals and actions to apply to those signals.\n\
7149 If no actions are specified, the current settings for the specified signals\n\
7150 will be displayed instead.\n\
7152 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7153 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7154 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7155 The special arg \"all\" is recognized to mean all signals except those\n\
7156 used by the debugger, typically SIGTRAP and SIGINT.\n\
7158 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7159 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7160 Stop means reenter debugger if this signal happens (implies print).\n\
7161 Print means print a message if this signal happens.\n\
7162 Pass means let program see this signal; otherwise program doesn't know.\n\
7163 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7164 Pass and Stop may be combined.\n\
7166 Multiple signals may be specified. Signal numbers and signal names\n\
7167 may be interspersed with actions, with the actions being performed for\n\
7168 all signals cumulatively specified."));
7169 set_cmd_completer (c, handle_completer);
7173 add_com ("lz", class_info, signals_info, _("\
7174 What debugger does when program gets various signals.\n\
7175 Specify a signal as argument to print info on that signal only."));
7176 add_com ("z", class_run, xdb_handle_command, _("\
7177 Specify how to handle a signal.\n\
7178 Args are signals and actions to apply to those signals.\n\
7179 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7180 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7181 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7182 The special arg \"all\" is recognized to mean all signals except those\n\
7183 used by the debugger, typically SIGTRAP and SIGINT.\n\
7184 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7185 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7186 nopass), \"Q\" (noprint)\n\
7187 Stop means reenter debugger if this signal happens (implies print).\n\
7188 Print means print a message if this signal happens.\n\
7189 Pass means let program see this signal; otherwise program doesn't know.\n\
7190 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7191 Pass and Stop may be combined."));
7195 stop_command = add_cmd ("stop", class_obscure,
7196 not_just_help_class_command, _("\
7197 There is no `stop' command, but you can set a hook on `stop'.\n\
7198 This allows you to set a list of commands to be run each time execution\n\
7199 of the program stops."), &cmdlist);
7201 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7202 Set inferior debugging."), _("\
7203 Show inferior debugging."), _("\
7204 When non-zero, inferior specific debugging is enabled."),
7207 &setdebuglist, &showdebuglist);
7209 add_setshow_boolean_cmd ("displaced", class_maintenance,
7210 &debug_displaced, _("\
7211 Set displaced stepping debugging."), _("\
7212 Show displaced stepping debugging."), _("\
7213 When non-zero, displaced stepping specific debugging is enabled."),
7215 show_debug_displaced,
7216 &setdebuglist, &showdebuglist);
7218 add_setshow_boolean_cmd ("non-stop", no_class,
7220 Set whether gdb controls the inferior in non-stop mode."), _("\
7221 Show whether gdb controls the inferior in non-stop mode."), _("\
7222 When debugging a multi-threaded program and this setting is\n\
7223 off (the default, also called all-stop mode), when one thread stops\n\
7224 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7225 all other threads in the program while you interact with the thread of\n\
7226 interest. When you continue or step a thread, you can allow the other\n\
7227 threads to run, or have them remain stopped, but while you inspect any\n\
7228 thread's state, all threads stop.\n\
7230 In non-stop mode, when one thread stops, other threads can continue\n\
7231 to run freely. You'll be able to step each thread independently,\n\
7232 leave it stopped or free to run as needed."),
7238 numsigs = (int) GDB_SIGNAL_LAST;
7239 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7240 signal_print = (unsigned char *)
7241 xmalloc (sizeof (signal_print[0]) * numsigs);
7242 signal_program = (unsigned char *)
7243 xmalloc (sizeof (signal_program[0]) * numsigs);
7244 signal_catch = (unsigned char *)
7245 xmalloc (sizeof (signal_catch[0]) * numsigs);
7246 signal_pass = (unsigned char *)
7247 xmalloc (sizeof (signal_program[0]) * numsigs);
7248 for (i = 0; i < numsigs; i++)
7251 signal_print[i] = 1;
7252 signal_program[i] = 1;
7253 signal_catch[i] = 0;
7256 /* Signals caused by debugger's own actions
7257 should not be given to the program afterwards. */
7258 signal_program[GDB_SIGNAL_TRAP] = 0;
7259 signal_program[GDB_SIGNAL_INT] = 0;
7261 /* Signals that are not errors should not normally enter the debugger. */
7262 signal_stop[GDB_SIGNAL_ALRM] = 0;
7263 signal_print[GDB_SIGNAL_ALRM] = 0;
7264 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7265 signal_print[GDB_SIGNAL_VTALRM] = 0;
7266 signal_stop[GDB_SIGNAL_PROF] = 0;
7267 signal_print[GDB_SIGNAL_PROF] = 0;
7268 signal_stop[GDB_SIGNAL_CHLD] = 0;
7269 signal_print[GDB_SIGNAL_CHLD] = 0;
7270 signal_stop[GDB_SIGNAL_IO] = 0;
7271 signal_print[GDB_SIGNAL_IO] = 0;
7272 signal_stop[GDB_SIGNAL_POLL] = 0;
7273 signal_print[GDB_SIGNAL_POLL] = 0;
7274 signal_stop[GDB_SIGNAL_URG] = 0;
7275 signal_print[GDB_SIGNAL_URG] = 0;
7276 signal_stop[GDB_SIGNAL_WINCH] = 0;
7277 signal_print[GDB_SIGNAL_WINCH] = 0;
7278 signal_stop[GDB_SIGNAL_PRIO] = 0;
7279 signal_print[GDB_SIGNAL_PRIO] = 0;
7281 /* These signals are used internally by user-level thread
7282 implementations. (See signal(5) on Solaris.) Like the above
7283 signals, a healthy program receives and handles them as part of
7284 its normal operation. */
7285 signal_stop[GDB_SIGNAL_LWP] = 0;
7286 signal_print[GDB_SIGNAL_LWP] = 0;
7287 signal_stop[GDB_SIGNAL_WAITING] = 0;
7288 signal_print[GDB_SIGNAL_WAITING] = 0;
7289 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7290 signal_print[GDB_SIGNAL_CANCEL] = 0;
7292 /* Update cached state. */
7293 signal_cache_update (-1);
7295 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7296 &stop_on_solib_events, _("\
7297 Set stopping for shared library events."), _("\
7298 Show stopping for shared library events."), _("\
7299 If nonzero, gdb will give control to the user when the dynamic linker\n\
7300 notifies gdb of shared library events. The most common event of interest\n\
7301 to the user would be loading/unloading of a new library."),
7302 set_stop_on_solib_events,
7303 show_stop_on_solib_events,
7304 &setlist, &showlist);
7306 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7307 follow_fork_mode_kind_names,
7308 &follow_fork_mode_string, _("\
7309 Set debugger response to a program call of fork or vfork."), _("\
7310 Show debugger response to a program call of fork or vfork."), _("\
7311 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7312 parent - the original process is debugged after a fork\n\
7313 child - the new process is debugged after a fork\n\
7314 The unfollowed process will continue to run.\n\
7315 By default, the debugger will follow the parent process."),
7317 show_follow_fork_mode_string,
7318 &setlist, &showlist);
7320 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7321 follow_exec_mode_names,
7322 &follow_exec_mode_string, _("\
7323 Set debugger response to a program call of exec."), _("\
7324 Show debugger response to a program call of exec."), _("\
7325 An exec call replaces the program image of a process.\n\
7327 follow-exec-mode can be:\n\
7329 new - the debugger creates a new inferior and rebinds the process\n\
7330 to this new inferior. The program the process was running before\n\
7331 the exec call can be restarted afterwards by restarting the original\n\
7334 same - the debugger keeps the process bound to the same inferior.\n\
7335 The new executable image replaces the previous executable loaded in\n\
7336 the inferior. Restarting the inferior after the exec call restarts\n\
7337 the executable the process was running after the exec call.\n\
7339 By default, the debugger will use the same inferior."),
7341 show_follow_exec_mode_string,
7342 &setlist, &showlist);
7344 add_setshow_enum_cmd ("scheduler-locking", class_run,
7345 scheduler_enums, &scheduler_mode, _("\
7346 Set mode for locking scheduler during execution."), _("\
7347 Show mode for locking scheduler during execution."), _("\
7348 off == no locking (threads may preempt at any time)\n\
7349 on == full locking (no thread except the current thread may run)\n\
7350 step == scheduler locked during every single-step operation.\n\
7351 In this mode, no other thread may run during a step command.\n\
7352 Other threads may run while stepping over a function call ('next')."),
7353 set_schedlock_func, /* traps on target vector */
7354 show_scheduler_mode,
7355 &setlist, &showlist);
7357 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7358 Set mode for resuming threads of all processes."), _("\
7359 Show mode for resuming threads of all processes."), _("\
7360 When on, execution commands (such as 'continue' or 'next') resume all\n\
7361 threads of all processes. When off (which is the default), execution\n\
7362 commands only resume the threads of the current process. The set of\n\
7363 threads that are resumed is further refined by the scheduler-locking\n\
7364 mode (see help set scheduler-locking)."),
7366 show_schedule_multiple,
7367 &setlist, &showlist);
7369 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7370 Set mode of the step operation."), _("\
7371 Show mode of the step operation."), _("\
7372 When set, doing a step over a function without debug line information\n\
7373 will stop at the first instruction of that function. Otherwise, the\n\
7374 function is skipped and the step command stops at a different source line."),
7376 show_step_stop_if_no_debug,
7377 &setlist, &showlist);
7379 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7380 &can_use_displaced_stepping, _("\
7381 Set debugger's willingness to use displaced stepping."), _("\
7382 Show debugger's willingness to use displaced stepping."), _("\
7383 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7384 supported by the target architecture. If off, gdb will not use displaced\n\
7385 stepping to step over breakpoints, even if such is supported by the target\n\
7386 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7387 if the target architecture supports it and non-stop mode is active, but will not\n\
7388 use it in all-stop mode (see help set non-stop)."),
7390 show_can_use_displaced_stepping,
7391 &setlist, &showlist);
7393 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7394 &exec_direction, _("Set direction of execution.\n\
7395 Options are 'forward' or 'reverse'."),
7396 _("Show direction of execution (forward/reverse)."),
7397 _("Tells gdb whether to execute forward or backward."),
7398 set_exec_direction_func, show_exec_direction_func,
7399 &setlist, &showlist);
7401 /* Set/show detach-on-fork: user-settable mode. */
7403 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7404 Set whether gdb will detach the child of a fork."), _("\
7405 Show whether gdb will detach the child of a fork."), _("\
7406 Tells gdb whether to detach the child of a fork."),
7407 NULL, NULL, &setlist, &showlist);
7409 /* Set/show disable address space randomization mode. */
7411 add_setshow_boolean_cmd ("disable-randomization", class_support,
7412 &disable_randomization, _("\
7413 Set disabling of debuggee's virtual address space randomization."), _("\
7414 Show disabling of debuggee's virtual address space randomization."), _("\
7415 When this mode is on (which is the default), randomization of the virtual\n\
7416 address space is disabled. Standalone programs run with the randomization\n\
7417 enabled by default on some platforms."),
7418 &set_disable_randomization,
7419 &show_disable_randomization,
7420 &setlist, &showlist);
7422 /* ptid initializations */
7423 inferior_ptid = null_ptid;
7424 target_last_wait_ptid = minus_one_ptid;
7426 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7427 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7428 observer_attach_thread_exit (infrun_thread_thread_exit);
7429 observer_attach_inferior_exit (infrun_inferior_exit);
7431 /* Explicitly create without lookup, since that tries to create a
7432 value with a void typed value, and when we get here, gdbarch
7433 isn't initialized yet. At this point, we're quite sure there
7434 isn't another convenience variable of the same name. */
7435 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7437 add_setshow_boolean_cmd ("observer", no_class,
7438 &observer_mode_1, _("\
7439 Set whether gdb controls the inferior in observer mode."), _("\
7440 Show whether gdb controls the inferior in observer mode."), _("\
7441 In observer mode, GDB can get data from the inferior, but not\n\
7442 affect its execution. Registers and memory may not be changed,\n\
7443 breakpoints may not be set, and the program cannot be interrupted\n\