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=%s), "
1753 "trap_expected=%d, current thread [%s] at %s\n",
1754 step, gdb_signal_to_symbol_string (sig),
1755 tp->control.trap_expected,
1756 target_pid_to_str (inferior_ptid),
1757 paddress (gdbarch, pc));
1759 /* Normally, by the time we reach `resume', the breakpoints are either
1760 removed or inserted, as appropriate. The exception is if we're sitting
1761 at a permanent breakpoint; we need to step over it, but permanent
1762 breakpoints can't be removed. So we have to test for it here. */
1763 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1765 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1766 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1769 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1770 how to step past a permanent breakpoint on this architecture. Try using\n\
1771 a command like `return' or `jump' to continue execution."));
1774 /* If we have a breakpoint to step over, make sure to do a single
1775 step only. Same if we have software watchpoints. */
1776 if (tp->control.trap_expected || bpstat_should_step ())
1777 tp->control.may_range_step = 0;
1779 /* If enabled, step over breakpoints by executing a copy of the
1780 instruction at a different address.
1782 We can't use displaced stepping when we have a signal to deliver;
1783 the comments for displaced_step_prepare explain why. The
1784 comments in the handle_inferior event for dealing with 'random
1785 signals' explain what we do instead.
1787 We can't use displaced stepping when we are waiting for vfork_done
1788 event, displaced stepping breaks the vfork child similarly as single
1789 step software breakpoint. */
1790 if (use_displaced_stepping (gdbarch)
1791 && (tp->control.trap_expected
1792 || (step && gdbarch_software_single_step_p (gdbarch)))
1793 && sig == GDB_SIGNAL_0
1794 && !current_inferior ()->waiting_for_vfork_done)
1796 struct displaced_step_inferior_state *displaced;
1798 if (!displaced_step_prepare (inferior_ptid))
1800 /* Got placed in displaced stepping queue. Will be resumed
1801 later when all the currently queued displaced stepping
1802 requests finish. The thread is not executing at this point,
1803 and the call to set_executing will be made later. But we
1804 need to call set_running here, since from frontend point of view,
1805 the thread is running. */
1806 set_running (inferior_ptid, 1);
1807 discard_cleanups (old_cleanups);
1811 /* Update pc to reflect the new address from which we will execute
1812 instructions due to displaced stepping. */
1813 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
1815 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1816 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
1817 displaced->step_closure);
1820 /* Do we need to do it the hard way, w/temp breakpoints? */
1822 step = maybe_software_singlestep (gdbarch, pc);
1824 /* Currently, our software single-step implementation leads to different
1825 results than hardware single-stepping in one situation: when stepping
1826 into delivering a signal which has an associated signal handler,
1827 hardware single-step will stop at the first instruction of the handler,
1828 while software single-step will simply skip execution of the handler.
1830 For now, this difference in behavior is accepted since there is no
1831 easy way to actually implement single-stepping into a signal handler
1832 without kernel support.
1834 However, there is one scenario where this difference leads to follow-on
1835 problems: if we're stepping off a breakpoint by removing all breakpoints
1836 and then single-stepping. In this case, the software single-step
1837 behavior means that even if there is a *breakpoint* in the signal
1838 handler, GDB still would not stop.
1840 Fortunately, we can at least fix this particular issue. We detect
1841 here the case where we are about to deliver a signal while software
1842 single-stepping with breakpoints removed. In this situation, we
1843 revert the decisions to remove all breakpoints and insert single-
1844 step breakpoints, and instead we install a step-resume breakpoint
1845 at the current address, deliver the signal without stepping, and
1846 once we arrive back at the step-resume breakpoint, actually step
1847 over the breakpoint we originally wanted to step over. */
1848 if (singlestep_breakpoints_inserted_p
1849 && tp->control.trap_expected && sig != GDB_SIGNAL_0)
1851 /* If we have nested signals or a pending signal is delivered
1852 immediately after a handler returns, might might already have
1853 a step-resume breakpoint set on the earlier handler. We cannot
1854 set another step-resume breakpoint; just continue on until the
1855 original breakpoint is hit. */
1856 if (tp->control.step_resume_breakpoint == NULL)
1858 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
1859 tp->step_after_step_resume_breakpoint = 1;
1862 remove_single_step_breakpoints ();
1863 singlestep_breakpoints_inserted_p = 0;
1865 insert_breakpoints ();
1866 tp->control.trap_expected = 0;
1873 /* If STEP is set, it's a request to use hardware stepping
1874 facilities. But in that case, we should never
1875 use singlestep breakpoint. */
1876 gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1878 /* Decide the set of threads to ask the target to resume. Start
1879 by assuming everything will be resumed, than narrow the set
1880 by applying increasingly restricting conditions. */
1881 resume_ptid = user_visible_resume_ptid (step);
1883 /* Maybe resume a single thread after all. */
1884 if (singlestep_breakpoints_inserted_p
1885 && stepping_past_singlestep_breakpoint)
1887 /* The situation here is as follows. In thread T1 we wanted to
1888 single-step. Lacking hardware single-stepping we've
1889 set breakpoint at the PC of the next instruction -- call it
1890 P. After resuming, we've hit that breakpoint in thread T2.
1891 Now we've removed original breakpoint, inserted breakpoint
1892 at P+1, and try to step to advance T2 past breakpoint.
1893 We need to step only T2, as if T1 is allowed to freely run,
1894 it can run past P, and if other threads are allowed to run,
1895 they can hit breakpoint at P+1, and nested hits of single-step
1896 breakpoints is not something we'd want -- that's complicated
1897 to support, and has no value. */
1898 resume_ptid = inferior_ptid;
1900 else if ((step || singlestep_breakpoints_inserted_p)
1901 && tp->control.trap_expected)
1903 /* We're allowing a thread to run past a breakpoint it has
1904 hit, by single-stepping the thread with the breakpoint
1905 removed. In which case, we need to single-step only this
1906 thread, and keep others stopped, as they can miss this
1907 breakpoint if allowed to run.
1909 The current code actually removes all breakpoints when
1910 doing this, not just the one being stepped over, so if we
1911 let other threads run, we can actually miss any
1912 breakpoint, not just the one at PC. */
1913 resume_ptid = inferior_ptid;
1916 if (gdbarch_cannot_step_breakpoint (gdbarch))
1918 /* Most targets can step a breakpoint instruction, thus
1919 executing it normally. But if this one cannot, just
1920 continue and we will hit it anyway. */
1921 if (step && breakpoint_inserted_here_p (aspace, pc))
1926 && use_displaced_stepping (gdbarch)
1927 && tp->control.trap_expected)
1929 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1930 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1931 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1934 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1935 paddress (resume_gdbarch, actual_pc));
1936 read_memory (actual_pc, buf, sizeof (buf));
1937 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1940 if (tp->control.may_range_step)
1942 /* If we're resuming a thread with the PC out of the step
1943 range, then we're doing some nested/finer run control
1944 operation, like stepping the thread out of the dynamic
1945 linker or the displaced stepping scratch pad. We
1946 shouldn't have allowed a range step then. */
1947 gdb_assert (pc_in_thread_step_range (pc, tp));
1950 /* Install inferior's terminal modes. */
1951 target_terminal_inferior ();
1953 /* Avoid confusing the next resume, if the next stop/resume
1954 happens to apply to another thread. */
1955 tp->suspend.stop_signal = GDB_SIGNAL_0;
1957 /* Advise target which signals may be handled silently. If we have
1958 removed breakpoints because we are stepping over one (which can
1959 happen only if we are not using displaced stepping), we need to
1960 receive all signals to avoid accidentally skipping a breakpoint
1961 during execution of a signal handler. */
1962 if ((step || singlestep_breakpoints_inserted_p)
1963 && tp->control.trap_expected
1964 && !use_displaced_stepping (gdbarch))
1965 target_pass_signals (0, NULL);
1967 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
1969 target_resume (resume_ptid, step, sig);
1972 discard_cleanups (old_cleanups);
1977 /* Clear out all variables saying what to do when inferior is continued.
1978 First do this, then set the ones you want, then call `proceed'. */
1981 clear_proceed_status_thread (struct thread_info *tp)
1984 fprintf_unfiltered (gdb_stdlog,
1985 "infrun: clear_proceed_status_thread (%s)\n",
1986 target_pid_to_str (tp->ptid));
1988 tp->control.trap_expected = 0;
1989 tp->control.step_range_start = 0;
1990 tp->control.step_range_end = 0;
1991 tp->control.may_range_step = 0;
1992 tp->control.step_frame_id = null_frame_id;
1993 tp->control.step_stack_frame_id = null_frame_id;
1994 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
1995 tp->stop_requested = 0;
1997 tp->control.stop_step = 0;
1999 tp->control.proceed_to_finish = 0;
2001 /* Discard any remaining commands or status from previous stop. */
2002 bpstat_clear (&tp->control.stop_bpstat);
2006 clear_proceed_status_callback (struct thread_info *tp, void *data)
2008 if (is_exited (tp->ptid))
2011 clear_proceed_status_thread (tp);
2016 clear_proceed_status (void)
2020 /* In all-stop mode, delete the per-thread status of all
2021 threads, even if inferior_ptid is null_ptid, there may be
2022 threads on the list. E.g., we may be launching a new
2023 process, while selecting the executable. */
2024 iterate_over_threads (clear_proceed_status_callback, NULL);
2027 if (!ptid_equal (inferior_ptid, null_ptid))
2029 struct inferior *inferior;
2033 /* If in non-stop mode, only delete the per-thread status of
2034 the current thread. */
2035 clear_proceed_status_thread (inferior_thread ());
2038 inferior = current_inferior ();
2039 inferior->control.stop_soon = NO_STOP_QUIETLY;
2042 stop_after_trap = 0;
2044 observer_notify_about_to_proceed ();
2048 regcache_xfree (stop_registers);
2049 stop_registers = NULL;
2053 /* Check the current thread against the thread that reported the most recent
2054 event. If a step-over is required return TRUE and set the current thread
2055 to the old thread. Otherwise return FALSE.
2057 This should be suitable for any targets that support threads. */
2060 prepare_to_proceed (int step)
2063 struct target_waitstatus wait_status;
2064 int schedlock_enabled;
2066 /* With non-stop mode on, threads are always handled individually. */
2067 gdb_assert (! non_stop);
2069 /* Get the last target status returned by target_wait(). */
2070 get_last_target_status (&wait_ptid, &wait_status);
2072 /* Make sure we were stopped at a breakpoint. */
2073 if (wait_status.kind != TARGET_WAITKIND_STOPPED
2074 || (wait_status.value.sig != GDB_SIGNAL_TRAP
2075 && wait_status.value.sig != GDB_SIGNAL_ILL
2076 && wait_status.value.sig != GDB_SIGNAL_SEGV
2077 && wait_status.value.sig != GDB_SIGNAL_EMT))
2082 schedlock_enabled = (scheduler_mode == schedlock_on
2083 || (scheduler_mode == schedlock_step
2086 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
2087 if (schedlock_enabled)
2090 /* Don't switch over if we're about to resume some other process
2091 other than WAIT_PTID's, and schedule-multiple is off. */
2093 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
2096 /* Switched over from WAIT_PID. */
2097 if (!ptid_equal (wait_ptid, minus_one_ptid)
2098 && !ptid_equal (inferior_ptid, wait_ptid))
2100 struct regcache *regcache = get_thread_regcache (wait_ptid);
2102 if (breakpoint_here_p (get_regcache_aspace (regcache),
2103 regcache_read_pc (regcache)))
2105 /* If stepping, remember current thread to switch back to. */
2107 deferred_step_ptid = inferior_ptid;
2109 /* Switch back to WAIT_PID thread. */
2110 switch_to_thread (wait_ptid);
2113 fprintf_unfiltered (gdb_stdlog,
2114 "infrun: prepare_to_proceed (step=%d), "
2115 "switched to [%s]\n",
2116 step, target_pid_to_str (inferior_ptid));
2118 /* We return 1 to indicate that there is a breakpoint here,
2119 so we need to step over it before continuing to avoid
2120 hitting it straight away. */
2128 /* Basic routine for continuing the program in various fashions.
2130 ADDR is the address to resume at, or -1 for resume where stopped.
2131 SIGGNAL is the signal to give it, or 0 for none,
2132 or -1 for act according to how it stopped.
2133 STEP is nonzero if should trap after one instruction.
2134 -1 means return after that and print nothing.
2135 You should probably set various step_... variables
2136 before calling here, if you are stepping.
2138 You should call clear_proceed_status before calling proceed. */
2141 proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
2143 struct regcache *regcache;
2144 struct gdbarch *gdbarch;
2145 struct thread_info *tp;
2147 struct address_space *aspace;
2148 /* GDB may force the inferior to step due to various reasons. */
2151 /* If we're stopped at a fork/vfork, follow the branch set by the
2152 "set follow-fork-mode" command; otherwise, we'll just proceed
2153 resuming the current thread. */
2154 if (!follow_fork ())
2156 /* The target for some reason decided not to resume. */
2158 if (target_can_async_p ())
2159 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2163 /* We'll update this if & when we switch to a new thread. */
2164 previous_inferior_ptid = inferior_ptid;
2166 regcache = get_current_regcache ();
2167 gdbarch = get_regcache_arch (regcache);
2168 aspace = get_regcache_aspace (regcache);
2169 pc = regcache_read_pc (regcache);
2172 step_start_function = find_pc_function (pc);
2174 stop_after_trap = 1;
2176 if (addr == (CORE_ADDR) -1)
2178 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
2179 && execution_direction != EXEC_REVERSE)
2180 /* There is a breakpoint at the address we will resume at,
2181 step one instruction before inserting breakpoints so that
2182 we do not stop right away (and report a second hit at this
2185 Note, we don't do this in reverse, because we won't
2186 actually be executing the breakpoint insn anyway.
2187 We'll be (un-)executing the previous instruction. */
2190 else if (gdbarch_single_step_through_delay_p (gdbarch)
2191 && gdbarch_single_step_through_delay (gdbarch,
2192 get_current_frame ()))
2193 /* We stepped onto an instruction that needs to be stepped
2194 again before re-inserting the breakpoint, do so. */
2199 regcache_write_pc (regcache, addr);
2203 fprintf_unfiltered (gdb_stdlog,
2204 "infrun: proceed (addr=%s, signal=%s, step=%d)\n",
2205 paddress (gdbarch, addr),
2206 gdb_signal_to_symbol_string (siggnal), step);
2209 /* In non-stop, each thread is handled individually. The context
2210 must already be set to the right thread here. */
2214 /* In a multi-threaded task we may select another thread and
2215 then continue or step.
2217 But if the old thread was stopped at a breakpoint, it will
2218 immediately cause another breakpoint stop without any
2219 execution (i.e. it will report a breakpoint hit incorrectly).
2220 So we must step over it first.
2222 prepare_to_proceed checks the current thread against the
2223 thread that reported the most recent event. If a step-over
2224 is required it returns TRUE and sets the current thread to
2226 if (prepare_to_proceed (step))
2230 /* prepare_to_proceed may change the current thread. */
2231 tp = inferior_thread ();
2235 tp->control.trap_expected = 1;
2236 /* If displaced stepping is enabled, we can step over the
2237 breakpoint without hitting it, so leave all breakpoints
2238 inserted. Otherwise we need to disable all breakpoints, step
2239 one instruction, and then re-add them when that step is
2241 if (!use_displaced_stepping (gdbarch))
2242 remove_breakpoints ();
2245 /* We can insert breakpoints if we're not trying to step over one,
2246 or if we are stepping over one but we're using displaced stepping
2248 if (! tp->control.trap_expected || use_displaced_stepping (gdbarch))
2249 insert_breakpoints ();
2253 /* Pass the last stop signal to the thread we're resuming,
2254 irrespective of whether the current thread is the thread that
2255 got the last event or not. This was historically GDB's
2256 behaviour before keeping a stop_signal per thread. */
2258 struct thread_info *last_thread;
2260 struct target_waitstatus last_status;
2262 get_last_target_status (&last_ptid, &last_status);
2263 if (!ptid_equal (inferior_ptid, last_ptid)
2264 && !ptid_equal (last_ptid, null_ptid)
2265 && !ptid_equal (last_ptid, minus_one_ptid))
2267 last_thread = find_thread_ptid (last_ptid);
2270 tp->suspend.stop_signal = last_thread->suspend.stop_signal;
2271 last_thread->suspend.stop_signal = GDB_SIGNAL_0;
2276 if (siggnal != GDB_SIGNAL_DEFAULT)
2277 tp->suspend.stop_signal = siggnal;
2278 /* If this signal should not be seen by program,
2279 give it zero. Used for debugging signals. */
2280 else if (!signal_program[tp->suspend.stop_signal])
2281 tp->suspend.stop_signal = GDB_SIGNAL_0;
2283 annotate_starting ();
2285 /* Make sure that output from GDB appears before output from the
2287 gdb_flush (gdb_stdout);
2289 /* Refresh prev_pc value just prior to resuming. This used to be
2290 done in stop_stepping, however, setting prev_pc there did not handle
2291 scenarios such as inferior function calls or returning from
2292 a function via the return command. In those cases, the prev_pc
2293 value was not set properly for subsequent commands. The prev_pc value
2294 is used to initialize the starting line number in the ecs. With an
2295 invalid value, the gdb next command ends up stopping at the position
2296 represented by the next line table entry past our start position.
2297 On platforms that generate one line table entry per line, this
2298 is not a problem. However, on the ia64, the compiler generates
2299 extraneous line table entries that do not increase the line number.
2300 When we issue the gdb next command on the ia64 after an inferior call
2301 or a return command, we often end up a few instructions forward, still
2302 within the original line we started.
2304 An attempt was made to refresh the prev_pc at the same time the
2305 execution_control_state is initialized (for instance, just before
2306 waiting for an inferior event). But this approach did not work
2307 because of platforms that use ptrace, where the pc register cannot
2308 be read unless the inferior is stopped. At that point, we are not
2309 guaranteed the inferior is stopped and so the regcache_read_pc() call
2310 can fail. Setting the prev_pc value here ensures the value is updated
2311 correctly when the inferior is stopped. */
2312 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2314 /* Fill in with reasonable starting values. */
2315 init_thread_stepping_state (tp);
2317 /* Reset to normal state. */
2318 init_infwait_state ();
2320 /* Resume inferior. */
2321 resume (force_step || step || bpstat_should_step (),
2322 tp->suspend.stop_signal);
2324 /* Wait for it to stop (if not standalone)
2325 and in any case decode why it stopped, and act accordingly. */
2326 /* Do this only if we are not using the event loop, or if the target
2327 does not support asynchronous execution. */
2328 if (!target_can_async_p ())
2330 wait_for_inferior ();
2336 /* Start remote-debugging of a machine over a serial link. */
2339 start_remote (int from_tty)
2341 struct inferior *inferior;
2343 inferior = current_inferior ();
2344 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2346 /* Always go on waiting for the target, regardless of the mode. */
2347 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2348 indicate to wait_for_inferior that a target should timeout if
2349 nothing is returned (instead of just blocking). Because of this,
2350 targets expecting an immediate response need to, internally, set
2351 things up so that the target_wait() is forced to eventually
2353 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2354 differentiate to its caller what the state of the target is after
2355 the initial open has been performed. Here we're assuming that
2356 the target has stopped. It should be possible to eventually have
2357 target_open() return to the caller an indication that the target
2358 is currently running and GDB state should be set to the same as
2359 for an async run. */
2360 wait_for_inferior ();
2362 /* Now that the inferior has stopped, do any bookkeeping like
2363 loading shared libraries. We want to do this before normal_stop,
2364 so that the displayed frame is up to date. */
2365 post_create_inferior (¤t_target, from_tty);
2370 /* Initialize static vars when a new inferior begins. */
2373 init_wait_for_inferior (void)
2375 /* These are meaningless until the first time through wait_for_inferior. */
2377 breakpoint_init_inferior (inf_starting);
2379 clear_proceed_status ();
2381 stepping_past_singlestep_breakpoint = 0;
2382 deferred_step_ptid = null_ptid;
2384 target_last_wait_ptid = minus_one_ptid;
2386 previous_inferior_ptid = inferior_ptid;
2387 init_infwait_state ();
2389 /* Discard any skipped inlined frames. */
2390 clear_inline_frame_state (minus_one_ptid);
2394 /* This enum encodes possible reasons for doing a target_wait, so that
2395 wfi can call target_wait in one place. (Ultimately the call will be
2396 moved out of the infinite loop entirely.) */
2400 infwait_normal_state,
2401 infwait_thread_hop_state,
2402 infwait_step_watch_state,
2403 infwait_nonstep_watch_state
2406 /* The PTID we'll do a target_wait on.*/
2409 /* Current inferior wait state. */
2410 static enum infwait_states infwait_state;
2412 /* Data to be passed around while handling an event. This data is
2413 discarded between events. */
2414 struct execution_control_state
2417 /* The thread that got the event, if this was a thread event; NULL
2419 struct thread_info *event_thread;
2421 struct target_waitstatus ws;
2423 int stop_func_filled_in;
2424 CORE_ADDR stop_func_start;
2425 CORE_ADDR stop_func_end;
2426 const char *stop_func_name;
2430 static void handle_inferior_event (struct execution_control_state *ecs);
2432 static void handle_step_into_function (struct gdbarch *gdbarch,
2433 struct execution_control_state *ecs);
2434 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2435 struct execution_control_state *ecs);
2436 static void check_exception_resume (struct execution_control_state *,
2437 struct frame_info *);
2439 static void stop_stepping (struct execution_control_state *ecs);
2440 static void prepare_to_wait (struct execution_control_state *ecs);
2441 static void keep_going (struct execution_control_state *ecs);
2442 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
2444 /* Callback for iterate over threads. If the thread is stopped, but
2445 the user/frontend doesn't know about that yet, go through
2446 normal_stop, as if the thread had just stopped now. ARG points at
2447 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2448 ptid_is_pid(PTID) is true, applies to all threads of the process
2449 pointed at by PTID. Otherwise, apply only to the thread pointed by
2453 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2455 ptid_t ptid = * (ptid_t *) arg;
2457 if ((ptid_equal (info->ptid, ptid)
2458 || ptid_equal (minus_one_ptid, ptid)
2459 || (ptid_is_pid (ptid)
2460 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2461 && is_running (info->ptid)
2462 && !is_executing (info->ptid))
2464 struct cleanup *old_chain;
2465 struct execution_control_state ecss;
2466 struct execution_control_state *ecs = &ecss;
2468 memset (ecs, 0, sizeof (*ecs));
2470 old_chain = make_cleanup_restore_current_thread ();
2472 /* Go through handle_inferior_event/normal_stop, so we always
2473 have consistent output as if the stop event had been
2475 ecs->ptid = info->ptid;
2476 ecs->event_thread = find_thread_ptid (info->ptid);
2477 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2478 ecs->ws.value.sig = GDB_SIGNAL_0;
2480 handle_inferior_event (ecs);
2482 if (!ecs->wait_some_more)
2484 struct thread_info *tp;
2488 /* Finish off the continuations. */
2489 tp = inferior_thread ();
2490 do_all_intermediate_continuations_thread (tp, 1);
2491 do_all_continuations_thread (tp, 1);
2494 do_cleanups (old_chain);
2500 /* This function is attached as a "thread_stop_requested" observer.
2501 Cleanup local state that assumed the PTID was to be resumed, and
2502 report the stop to the frontend. */
2505 infrun_thread_stop_requested (ptid_t ptid)
2507 struct displaced_step_inferior_state *displaced;
2509 /* PTID was requested to stop. Remove it from the displaced
2510 stepping queue, so we don't try to resume it automatically. */
2512 for (displaced = displaced_step_inferior_states;
2514 displaced = displaced->next)
2516 struct displaced_step_request *it, **prev_next_p;
2518 it = displaced->step_request_queue;
2519 prev_next_p = &displaced->step_request_queue;
2522 if (ptid_match (it->ptid, ptid))
2524 *prev_next_p = it->next;
2530 prev_next_p = &it->next;
2537 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2541 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2543 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2544 nullify_last_target_wait_ptid ();
2547 /* Callback for iterate_over_threads. */
2550 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2552 if (is_exited (info->ptid))
2555 delete_step_resume_breakpoint (info);
2556 delete_exception_resume_breakpoint (info);
2560 /* In all-stop, delete the step resume breakpoint of any thread that
2561 had one. In non-stop, delete the step resume breakpoint of the
2562 thread that just stopped. */
2565 delete_step_thread_step_resume_breakpoint (void)
2567 if (!target_has_execution
2568 || ptid_equal (inferior_ptid, null_ptid))
2569 /* If the inferior has exited, we have already deleted the step
2570 resume breakpoints out of GDB's lists. */
2575 /* If in non-stop mode, only delete the step-resume or
2576 longjmp-resume breakpoint of the thread that just stopped
2578 struct thread_info *tp = inferior_thread ();
2580 delete_step_resume_breakpoint (tp);
2581 delete_exception_resume_breakpoint (tp);
2584 /* In all-stop mode, delete all step-resume and longjmp-resume
2585 breakpoints of any thread that had them. */
2586 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2589 /* A cleanup wrapper. */
2592 delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2594 delete_step_thread_step_resume_breakpoint ();
2597 /* Pretty print the results of target_wait, for debugging purposes. */
2600 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2601 const struct target_waitstatus *ws)
2603 char *status_string = target_waitstatus_to_string (ws);
2604 struct ui_file *tmp_stream = mem_fileopen ();
2607 /* The text is split over several lines because it was getting too long.
2608 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2609 output as a unit; we want only one timestamp printed if debug_timestamp
2612 fprintf_unfiltered (tmp_stream,
2613 "infrun: target_wait (%d", ptid_get_pid (waiton_ptid));
2614 if (ptid_get_pid (waiton_ptid) != -1)
2615 fprintf_unfiltered (tmp_stream,
2616 " [%s]", target_pid_to_str (waiton_ptid));
2617 fprintf_unfiltered (tmp_stream, ", status) =\n");
2618 fprintf_unfiltered (tmp_stream,
2619 "infrun: %d [%s],\n",
2620 ptid_get_pid (result_ptid),
2621 target_pid_to_str (result_ptid));
2622 fprintf_unfiltered (tmp_stream,
2626 text = ui_file_xstrdup (tmp_stream, NULL);
2628 /* This uses %s in part to handle %'s in the text, but also to avoid
2629 a gcc error: the format attribute requires a string literal. */
2630 fprintf_unfiltered (gdb_stdlog, "%s", text);
2632 xfree (status_string);
2634 ui_file_delete (tmp_stream);
2637 /* Prepare and stabilize the inferior for detaching it. E.g.,
2638 detaching while a thread is displaced stepping is a recipe for
2639 crashing it, as nothing would readjust the PC out of the scratch
2643 prepare_for_detach (void)
2645 struct inferior *inf = current_inferior ();
2646 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2647 struct cleanup *old_chain_1;
2648 struct displaced_step_inferior_state *displaced;
2650 displaced = get_displaced_stepping_state (inf->pid);
2652 /* Is any thread of this process displaced stepping? If not,
2653 there's nothing else to do. */
2654 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2658 fprintf_unfiltered (gdb_stdlog,
2659 "displaced-stepping in-process while detaching");
2661 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2664 while (!ptid_equal (displaced->step_ptid, null_ptid))
2666 struct cleanup *old_chain_2;
2667 struct execution_control_state ecss;
2668 struct execution_control_state *ecs;
2671 memset (ecs, 0, sizeof (*ecs));
2673 overlay_cache_invalid = 1;
2675 if (deprecated_target_wait_hook)
2676 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
2678 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
2681 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
2683 /* If an error happens while handling the event, propagate GDB's
2684 knowledge of the executing state to the frontend/user running
2686 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
2689 /* Now figure out what to do with the result of the result. */
2690 handle_inferior_event (ecs);
2692 /* No error, don't finish the state yet. */
2693 discard_cleanups (old_chain_2);
2695 /* Breakpoints and watchpoints are not installed on the target
2696 at this point, and signals are passed directly to the
2697 inferior, so this must mean the process is gone. */
2698 if (!ecs->wait_some_more)
2700 discard_cleanups (old_chain_1);
2701 error (_("Program exited while detaching"));
2705 discard_cleanups (old_chain_1);
2708 /* Wait for control to return from inferior to debugger.
2710 If inferior gets a signal, we may decide to start it up again
2711 instead of returning. That is why there is a loop in this function.
2712 When this function actually returns it means the inferior
2713 should be left stopped and GDB should read more commands. */
2716 wait_for_inferior (void)
2718 struct cleanup *old_cleanups;
2722 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
2725 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2729 struct execution_control_state ecss;
2730 struct execution_control_state *ecs = &ecss;
2731 struct cleanup *old_chain;
2733 memset (ecs, 0, sizeof (*ecs));
2735 overlay_cache_invalid = 1;
2737 if (deprecated_target_wait_hook)
2738 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2740 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2743 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2745 /* If an error happens while handling the event, propagate GDB's
2746 knowledge of the executing state to the frontend/user running
2748 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2750 /* Now figure out what to do with the result of the result. */
2751 handle_inferior_event (ecs);
2753 /* No error, don't finish the state yet. */
2754 discard_cleanups (old_chain);
2756 if (!ecs->wait_some_more)
2760 do_cleanups (old_cleanups);
2763 /* Asynchronous version of wait_for_inferior. It is called by the
2764 event loop whenever a change of state is detected on the file
2765 descriptor corresponding to the target. It can be called more than
2766 once to complete a single execution command. In such cases we need
2767 to keep the state in a global variable ECSS. If it is the last time
2768 that this function is called for a single execution command, then
2769 report to the user that the inferior has stopped, and do the
2770 necessary cleanups. */
2773 fetch_inferior_event (void *client_data)
2775 struct execution_control_state ecss;
2776 struct execution_control_state *ecs = &ecss;
2777 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2778 struct cleanup *ts_old_chain;
2779 int was_sync = sync_execution;
2782 memset (ecs, 0, sizeof (*ecs));
2784 /* We're handling a live event, so make sure we're doing live
2785 debugging. If we're looking at traceframes while the target is
2786 running, we're going to need to get back to that mode after
2787 handling the event. */
2790 make_cleanup_restore_current_traceframe ();
2791 set_current_traceframe (-1);
2795 /* In non-stop mode, the user/frontend should not notice a thread
2796 switch due to internal events. Make sure we reverse to the
2797 user selected thread and frame after handling the event and
2798 running any breakpoint commands. */
2799 make_cleanup_restore_current_thread ();
2801 overlay_cache_invalid = 1;
2803 make_cleanup_restore_integer (&execution_direction);
2804 execution_direction = target_execution_direction ();
2806 if (deprecated_target_wait_hook)
2808 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2810 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2813 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2815 /* If an error happens while handling the event, propagate GDB's
2816 knowledge of the executing state to the frontend/user running
2819 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2821 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2823 /* Get executed before make_cleanup_restore_current_thread above to apply
2824 still for the thread which has thrown the exception. */
2825 make_bpstat_clear_actions_cleanup ();
2827 /* Now figure out what to do with the result of the result. */
2828 handle_inferior_event (ecs);
2830 if (!ecs->wait_some_more)
2832 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2834 delete_step_thread_step_resume_breakpoint ();
2836 /* We may not find an inferior if this was a process exit. */
2837 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
2840 if (target_has_execution
2841 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
2842 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2843 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2844 && ecs->event_thread->step_multi
2845 && ecs->event_thread->control.stop_step)
2846 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2849 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2854 /* No error, don't finish the thread states yet. */
2855 discard_cleanups (ts_old_chain);
2857 /* Revert thread and frame. */
2858 do_cleanups (old_chain);
2860 /* If the inferior was in sync execution mode, and now isn't,
2861 restore the prompt (a synchronous execution command has finished,
2862 and we're ready for input). */
2863 if (interpreter_async && was_sync && !sync_execution)
2864 display_gdb_prompt (0);
2868 && exec_done_display_p
2869 && (ptid_equal (inferior_ptid, null_ptid)
2870 || !is_running (inferior_ptid)))
2871 printf_unfiltered (_("completed.\n"));
2874 /* Record the frame and location we're currently stepping through. */
2876 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2878 struct thread_info *tp = inferior_thread ();
2880 tp->control.step_frame_id = get_frame_id (frame);
2881 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
2883 tp->current_symtab = sal.symtab;
2884 tp->current_line = sal.line;
2887 /* Clear context switchable stepping state. */
2890 init_thread_stepping_state (struct thread_info *tss)
2892 tss->stepping_over_breakpoint = 0;
2893 tss->step_after_step_resume_breakpoint = 0;
2896 /* Return the cached copy of the last pid/waitstatus returned by
2897 target_wait()/deprecated_target_wait_hook(). The data is actually
2898 cached by handle_inferior_event(), which gets called immediately
2899 after target_wait()/deprecated_target_wait_hook(). */
2902 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2904 *ptidp = target_last_wait_ptid;
2905 *status = target_last_waitstatus;
2909 nullify_last_target_wait_ptid (void)
2911 target_last_wait_ptid = minus_one_ptid;
2914 /* Switch thread contexts. */
2917 context_switch (ptid_t ptid)
2919 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
2921 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2922 target_pid_to_str (inferior_ptid));
2923 fprintf_unfiltered (gdb_stdlog, "to %s\n",
2924 target_pid_to_str (ptid));
2927 switch_to_thread (ptid);
2931 adjust_pc_after_break (struct execution_control_state *ecs)
2933 struct regcache *regcache;
2934 struct gdbarch *gdbarch;
2935 struct address_space *aspace;
2936 CORE_ADDR breakpoint_pc;
2938 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2939 we aren't, just return.
2941 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2942 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2943 implemented by software breakpoints should be handled through the normal
2946 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2947 different signals (SIGILL or SIGEMT for instance), but it is less
2948 clear where the PC is pointing afterwards. It may not match
2949 gdbarch_decr_pc_after_break. I don't know any specific target that
2950 generates these signals at breakpoints (the code has been in GDB since at
2951 least 1992) so I can not guess how to handle them here.
2953 In earlier versions of GDB, a target with
2954 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2955 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2956 target with both of these set in GDB history, and it seems unlikely to be
2957 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2959 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2962 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
2965 /* In reverse execution, when a breakpoint is hit, the instruction
2966 under it has already been de-executed. The reported PC always
2967 points at the breakpoint address, so adjusting it further would
2968 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2971 B1 0x08000000 : INSN1
2972 B2 0x08000001 : INSN2
2974 PC -> 0x08000003 : INSN4
2976 Say you're stopped at 0x08000003 as above. Reverse continuing
2977 from that point should hit B2 as below. Reading the PC when the
2978 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2979 been de-executed already.
2981 B1 0x08000000 : INSN1
2982 B2 PC -> 0x08000001 : INSN2
2986 We can't apply the same logic as for forward execution, because
2987 we would wrongly adjust the PC to 0x08000000, since there's a
2988 breakpoint at PC - 1. We'd then report a hit on B1, although
2989 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2991 if (execution_direction == EXEC_REVERSE)
2994 /* If this target does not decrement the PC after breakpoints, then
2995 we have nothing to do. */
2996 regcache = get_thread_regcache (ecs->ptid);
2997 gdbarch = get_regcache_arch (regcache);
2998 if (gdbarch_decr_pc_after_break (gdbarch) == 0)
3001 aspace = get_regcache_aspace (regcache);
3003 /* Find the location where (if we've hit a breakpoint) the
3004 breakpoint would be. */
3005 breakpoint_pc = regcache_read_pc (regcache)
3006 - gdbarch_decr_pc_after_break (gdbarch);
3008 /* Check whether there actually is a software breakpoint inserted at
3011 If in non-stop mode, a race condition is possible where we've
3012 removed a breakpoint, but stop events for that breakpoint were
3013 already queued and arrive later. To suppress those spurious
3014 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3015 and retire them after a number of stop events are reported. */
3016 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3017 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3019 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
3022 record_full_gdb_operation_disable_set ();
3024 /* When using hardware single-step, a SIGTRAP is reported for both
3025 a completed single-step and a software breakpoint. Need to
3026 differentiate between the two, as the latter needs adjusting
3027 but the former does not.
3029 The SIGTRAP can be due to a completed hardware single-step only if
3030 - we didn't insert software single-step breakpoints
3031 - the thread to be examined is still the current thread
3032 - this thread is currently being stepped
3034 If any of these events did not occur, we must have stopped due
3035 to hitting a software breakpoint, and have to back up to the
3038 As a special case, we could have hardware single-stepped a
3039 software breakpoint. In this case (prev_pc == breakpoint_pc),
3040 we also need to back up to the breakpoint address. */
3042 if (singlestep_breakpoints_inserted_p
3043 || !ptid_equal (ecs->ptid, inferior_ptid)
3044 || !currently_stepping (ecs->event_thread)
3045 || ecs->event_thread->prev_pc == breakpoint_pc)
3046 regcache_write_pc (regcache, breakpoint_pc);
3048 do_cleanups (old_cleanups);
3053 init_infwait_state (void)
3055 waiton_ptid = pid_to_ptid (-1);
3056 infwait_state = infwait_normal_state;
3060 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3062 for (frame = get_prev_frame (frame);
3064 frame = get_prev_frame (frame))
3066 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3068 if (get_frame_type (frame) != INLINE_FRAME)
3075 /* Auxiliary function that handles syscall entry/return events.
3076 It returns 1 if the inferior should keep going (and GDB
3077 should ignore the event), or 0 if the event deserves to be
3081 handle_syscall_event (struct execution_control_state *ecs)
3083 struct regcache *regcache;
3086 if (!ptid_equal (ecs->ptid, inferior_ptid))
3087 context_switch (ecs->ptid);
3089 regcache = get_thread_regcache (ecs->ptid);
3090 syscall_number = ecs->ws.value.syscall_number;
3091 stop_pc = regcache_read_pc (regcache);
3093 if (catch_syscall_enabled () > 0
3094 && catching_syscall_number (syscall_number) > 0)
3096 enum bpstat_signal_value sval;
3099 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3102 ecs->event_thread->control.stop_bpstat
3103 = bpstat_stop_status (get_regcache_aspace (regcache),
3104 stop_pc, ecs->ptid, &ecs->ws);
3106 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3108 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3110 if (!ecs->random_signal)
3112 /* Catchpoint hit. */
3113 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3118 /* If no catchpoint triggered for this, then keep going. */
3119 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3124 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3127 fill_in_stop_func (struct gdbarch *gdbarch,
3128 struct execution_control_state *ecs)
3130 if (!ecs->stop_func_filled_in)
3132 /* Don't care about return value; stop_func_start and stop_func_name
3133 will both be 0 if it doesn't work. */
3134 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3135 &ecs->stop_func_start, &ecs->stop_func_end);
3136 ecs->stop_func_start
3137 += gdbarch_deprecated_function_start_offset (gdbarch);
3139 ecs->stop_func_filled_in = 1;
3143 /* Given an execution control state that has been freshly filled in
3144 by an event from the inferior, figure out what it means and take
3145 appropriate action. */
3148 handle_inferior_event (struct execution_control_state *ecs)
3150 struct frame_info *frame;
3151 struct gdbarch *gdbarch;
3152 int stopped_by_watchpoint;
3153 int stepped_after_stopped_by_watchpoint = 0;
3154 struct symtab_and_line stop_pc_sal;
3155 enum stop_kind stop_soon;
3157 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3159 /* We had an event in the inferior, but we are not interested in
3160 handling it at this level. The lower layers have already
3161 done what needs to be done, if anything.
3163 One of the possible circumstances for this is when the
3164 inferior produces output for the console. The inferior has
3165 not stopped, and we are ignoring the event. Another possible
3166 circumstance is any event which the lower level knows will be
3167 reported multiple times without an intervening resume. */
3169 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3170 prepare_to_wait (ecs);
3174 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3175 && target_can_async_p () && !sync_execution)
3177 /* There were no unwaited-for children left in the target, but,
3178 we're not synchronously waiting for events either. Just
3179 ignore. Otherwise, if we were running a synchronous
3180 execution command, we need to cancel it and give the user
3181 back the terminal. */
3183 fprintf_unfiltered (gdb_stdlog,
3184 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3185 prepare_to_wait (ecs);
3189 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3190 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3191 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED)
3193 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
3196 stop_soon = inf->control.stop_soon;
3199 stop_soon = NO_STOP_QUIETLY;
3201 /* Cache the last pid/waitstatus. */
3202 target_last_wait_ptid = ecs->ptid;
3203 target_last_waitstatus = ecs->ws;
3205 /* Always clear state belonging to the previous time we stopped. */
3206 stop_stack_dummy = STOP_NONE;
3208 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3210 /* No unwaited-for children left. IOW, all resumed children
3213 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3215 stop_print_frame = 0;
3216 stop_stepping (ecs);
3220 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3221 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3223 ecs->event_thread = find_thread_ptid (ecs->ptid);
3224 /* If it's a new thread, add it to the thread database. */
3225 if (ecs->event_thread == NULL)
3226 ecs->event_thread = add_thread (ecs->ptid);
3228 /* Disable range stepping. If the next step request could use a
3229 range, this will be end up re-enabled then. */
3230 ecs->event_thread->control.may_range_step = 0;
3233 /* Dependent on valid ECS->EVENT_THREAD. */
3234 adjust_pc_after_break (ecs);
3236 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3237 reinit_frame_cache ();
3239 breakpoint_retire_moribund ();
3241 /* First, distinguish signals caused by the debugger from signals
3242 that have to do with the program's own actions. Note that
3243 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3244 on the operating system version. Here we detect when a SIGILL or
3245 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3246 something similar for SIGSEGV, since a SIGSEGV will be generated
3247 when we're trying to execute a breakpoint instruction on a
3248 non-executable stack. This happens for call dummy breakpoints
3249 for architectures like SPARC that place call dummies on the
3251 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3252 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3253 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3254 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3256 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3258 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3259 regcache_read_pc (regcache)))
3262 fprintf_unfiltered (gdb_stdlog,
3263 "infrun: Treating signal as SIGTRAP\n");
3264 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3268 /* Mark the non-executing threads accordingly. In all-stop, all
3269 threads of all processes are stopped when we get any event
3270 reported. In non-stop mode, only the event thread stops. If
3271 we're handling a process exit in non-stop mode, there's nothing
3272 to do, as threads of the dead process are gone, and threads of
3273 any other process were left running. */
3275 set_executing (minus_one_ptid, 0);
3276 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3277 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3278 set_executing (ecs->ptid, 0);
3280 switch (infwait_state)
3282 case infwait_thread_hop_state:
3284 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
3287 case infwait_normal_state:
3289 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
3292 case infwait_step_watch_state:
3294 fprintf_unfiltered (gdb_stdlog,
3295 "infrun: infwait_step_watch_state\n");
3297 stepped_after_stopped_by_watchpoint = 1;
3300 case infwait_nonstep_watch_state:
3302 fprintf_unfiltered (gdb_stdlog,
3303 "infrun: infwait_nonstep_watch_state\n");
3304 insert_breakpoints ();
3306 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3307 handle things like signals arriving and other things happening
3308 in combination correctly? */
3309 stepped_after_stopped_by_watchpoint = 1;
3313 internal_error (__FILE__, __LINE__, _("bad switch"));
3316 infwait_state = infwait_normal_state;
3317 waiton_ptid = pid_to_ptid (-1);
3319 switch (ecs->ws.kind)
3321 case TARGET_WAITKIND_LOADED:
3323 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3324 /* Ignore gracefully during startup of the inferior, as it might
3325 be the shell which has just loaded some objects, otherwise
3326 add the symbols for the newly loaded objects. Also ignore at
3327 the beginning of an attach or remote session; we will query
3328 the full list of libraries once the connection is
3330 if (stop_soon == NO_STOP_QUIETLY)
3332 struct regcache *regcache;
3333 enum bpstat_signal_value sval;
3335 if (!ptid_equal (ecs->ptid, inferior_ptid))
3336 context_switch (ecs->ptid);
3337 regcache = get_thread_regcache (ecs->ptid);
3339 handle_solib_event ();
3341 ecs->event_thread->control.stop_bpstat
3342 = bpstat_stop_status (get_regcache_aspace (regcache),
3343 stop_pc, ecs->ptid, &ecs->ws);
3346 = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3348 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3350 if (!ecs->random_signal)
3352 /* A catchpoint triggered. */
3353 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3354 goto process_event_stop_test;
3357 /* If requested, stop when the dynamic linker notifies
3358 gdb of events. This allows the user to get control
3359 and place breakpoints in initializer routines for
3360 dynamically loaded objects (among other things). */
3361 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3362 if (stop_on_solib_events)
3364 /* Make sure we print "Stopped due to solib-event" in
3366 stop_print_frame = 1;
3368 stop_stepping (ecs);
3373 /* If we are skipping through a shell, or through shared library
3374 loading that we aren't interested in, resume the program. If
3375 we're running the program normally, also resume. But stop if
3376 we're attaching or setting up a remote connection. */
3377 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3379 if (!ptid_equal (ecs->ptid, inferior_ptid))
3380 context_switch (ecs->ptid);
3382 /* Loading of shared libraries might have changed breakpoint
3383 addresses. Make sure new breakpoints are inserted. */
3384 if (stop_soon == NO_STOP_QUIETLY
3385 && !breakpoints_always_inserted_mode ())
3386 insert_breakpoints ();
3387 resume (0, GDB_SIGNAL_0);
3388 prepare_to_wait (ecs);
3394 case TARGET_WAITKIND_SPURIOUS:
3396 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3397 if (!ptid_equal (ecs->ptid, inferior_ptid))
3398 context_switch (ecs->ptid);
3399 resume (0, GDB_SIGNAL_0);
3400 prepare_to_wait (ecs);
3403 case TARGET_WAITKIND_EXITED:
3404 case TARGET_WAITKIND_SIGNALLED:
3407 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3408 fprintf_unfiltered (gdb_stdlog,
3409 "infrun: TARGET_WAITKIND_EXITED\n");
3411 fprintf_unfiltered (gdb_stdlog,
3412 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3415 inferior_ptid = ecs->ptid;
3416 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3417 set_current_program_space (current_inferior ()->pspace);
3418 handle_vfork_child_exec_or_exit (0);
3419 target_terminal_ours (); /* Must do this before mourn anyway. */
3421 /* Clearing any previous state of convenience variables. */
3422 clear_exit_convenience_vars ();
3424 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3426 /* Record the exit code in the convenience variable $_exitcode, so
3427 that the user can inspect this again later. */
3428 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3429 (LONGEST) ecs->ws.value.integer);
3431 /* Also record this in the inferior itself. */
3432 current_inferior ()->has_exit_code = 1;
3433 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3435 print_exited_reason (ecs->ws.value.integer);
3439 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3440 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3442 if (gdbarch_gdb_signal_to_target_p (gdbarch))
3444 /* Set the value of the internal variable $_exitsignal,
3445 which holds the signal uncaught by the inferior. */
3446 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
3447 gdbarch_gdb_signal_to_target (gdbarch,
3448 ecs->ws.value.sig));
3452 /* We don't have access to the target's method used for
3453 converting between signal numbers (GDB's internal
3454 representation <-> target's representation).
3455 Therefore, we cannot do a good job at displaying this
3456 information to the user. It's better to just warn
3457 her about it (if infrun debugging is enabled), and
3460 fprintf_filtered (gdb_stdlog, _("\
3461 Cannot fill $_exitsignal with the correct signal number.\n"));
3464 print_signal_exited_reason (ecs->ws.value.sig);
3467 gdb_flush (gdb_stdout);
3468 target_mourn_inferior ();
3469 singlestep_breakpoints_inserted_p = 0;
3470 cancel_single_step_breakpoints ();
3471 stop_print_frame = 0;
3472 stop_stepping (ecs);
3475 /* The following are the only cases in which we keep going;
3476 the above cases end in a continue or goto. */
3477 case TARGET_WAITKIND_FORKED:
3478 case TARGET_WAITKIND_VFORKED:
3481 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3482 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3484 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3487 /* Check whether the inferior is displaced stepping. */
3489 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3490 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3491 struct displaced_step_inferior_state *displaced
3492 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3494 /* If checking displaced stepping is supported, and thread
3495 ecs->ptid is displaced stepping. */
3496 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3498 struct inferior *parent_inf
3499 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3500 struct regcache *child_regcache;
3501 CORE_ADDR parent_pc;
3503 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3504 indicating that the displaced stepping of syscall instruction
3505 has been done. Perform cleanup for parent process here. Note
3506 that this operation also cleans up the child process for vfork,
3507 because their pages are shared. */
3508 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3510 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3512 /* Restore scratch pad for child process. */
3513 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3516 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3517 the child's PC is also within the scratchpad. Set the child's PC
3518 to the parent's PC value, which has already been fixed up.
3519 FIXME: we use the parent's aspace here, although we're touching
3520 the child, because the child hasn't been added to the inferior
3521 list yet at this point. */
3524 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3526 parent_inf->aspace);
3527 /* Read PC value of parent process. */
3528 parent_pc = regcache_read_pc (regcache);
3530 if (debug_displaced)
3531 fprintf_unfiltered (gdb_stdlog,
3532 "displaced: write child pc from %s to %s\n",
3534 regcache_read_pc (child_regcache)),
3535 paddress (gdbarch, parent_pc));
3537 regcache_write_pc (child_regcache, parent_pc);
3541 if (!ptid_equal (ecs->ptid, inferior_ptid))
3542 context_switch (ecs->ptid);
3544 /* Immediately detach breakpoints from the child before there's
3545 any chance of letting the user delete breakpoints from the
3546 breakpoint lists. If we don't do this early, it's easy to
3547 leave left over traps in the child, vis: "break foo; catch
3548 fork; c; <fork>; del; c; <child calls foo>". We only follow
3549 the fork on the last `continue', and by that time the
3550 breakpoint at "foo" is long gone from the breakpoint table.
3551 If we vforked, then we don't need to unpatch here, since both
3552 parent and child are sharing the same memory pages; we'll
3553 need to unpatch at follow/detach time instead to be certain
3554 that new breakpoints added between catchpoint hit time and
3555 vfork follow are detached. */
3556 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3558 /* This won't actually modify the breakpoint list, but will
3559 physically remove the breakpoints from the child. */
3560 detach_breakpoints (ecs->ws.value.related_pid);
3563 if (singlestep_breakpoints_inserted_p)
3565 /* Pull the single step breakpoints out of the target. */
3566 remove_single_step_breakpoints ();
3567 singlestep_breakpoints_inserted_p = 0;
3570 /* In case the event is caught by a catchpoint, remember that
3571 the event is to be followed at the next resume of the thread,
3572 and not immediately. */
3573 ecs->event_thread->pending_follow = ecs->ws;
3575 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3577 ecs->event_thread->control.stop_bpstat
3578 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3579 stop_pc, ecs->ptid, &ecs->ws);
3581 /* Note that we're interested in knowing the bpstat actually
3582 causes a stop, not just if it may explain the signal.
3583 Software watchpoints, for example, always appear in the
3586 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat);
3588 /* If no catchpoint triggered for this, then keep going. */
3589 if (ecs->random_signal)
3595 = (follow_fork_mode_string == follow_fork_mode_child);
3597 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3599 should_resume = follow_fork ();
3602 child = ecs->ws.value.related_pid;
3604 /* In non-stop mode, also resume the other branch. */
3605 if (non_stop && !detach_fork)
3608 switch_to_thread (parent);
3610 switch_to_thread (child);
3612 ecs->event_thread = inferior_thread ();
3613 ecs->ptid = inferior_ptid;
3618 switch_to_thread (child);
3620 switch_to_thread (parent);
3622 ecs->event_thread = inferior_thread ();
3623 ecs->ptid = inferior_ptid;
3628 stop_stepping (ecs);
3631 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3632 goto process_event_stop_test;
3634 case TARGET_WAITKIND_VFORK_DONE:
3635 /* Done with the shared memory region. Re-insert breakpoints in
3636 the parent, and keep going. */
3639 fprintf_unfiltered (gdb_stdlog,
3640 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3642 if (!ptid_equal (ecs->ptid, inferior_ptid))
3643 context_switch (ecs->ptid);
3645 current_inferior ()->waiting_for_vfork_done = 0;
3646 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3647 /* This also takes care of reinserting breakpoints in the
3648 previously locked inferior. */
3652 case TARGET_WAITKIND_EXECD:
3654 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3656 if (!ptid_equal (ecs->ptid, inferior_ptid))
3657 context_switch (ecs->ptid);
3659 singlestep_breakpoints_inserted_p = 0;
3660 cancel_single_step_breakpoints ();
3662 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3664 /* Do whatever is necessary to the parent branch of the vfork. */
3665 handle_vfork_child_exec_or_exit (1);
3667 /* This causes the eventpoints and symbol table to be reset.
3668 Must do this now, before trying to determine whether to
3670 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3672 ecs->event_thread->control.stop_bpstat
3673 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3674 stop_pc, ecs->ptid, &ecs->ws);
3676 = (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
3678 == BPSTAT_SIGNAL_NO);
3680 /* Note that this may be referenced from inside
3681 bpstat_stop_status above, through inferior_has_execd. */
3682 xfree (ecs->ws.value.execd_pathname);
3683 ecs->ws.value.execd_pathname = NULL;
3685 /* If no catchpoint triggered for this, then keep going. */
3686 if (ecs->random_signal)
3688 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3692 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3693 goto process_event_stop_test;
3695 /* Be careful not to try to gather much state about a thread
3696 that's in a syscall. It's frequently a losing proposition. */
3697 case TARGET_WAITKIND_SYSCALL_ENTRY:
3699 fprintf_unfiltered (gdb_stdlog,
3700 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3701 /* Getting the current syscall number. */
3702 if (handle_syscall_event (ecs) != 0)
3704 goto process_event_stop_test;
3706 /* Before examining the threads further, step this thread to
3707 get it entirely out of the syscall. (We get notice of the
3708 event when the thread is just on the verge of exiting a
3709 syscall. Stepping one instruction seems to get it back
3711 case TARGET_WAITKIND_SYSCALL_RETURN:
3713 fprintf_unfiltered (gdb_stdlog,
3714 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3715 if (handle_syscall_event (ecs) != 0)
3717 goto process_event_stop_test;
3719 case TARGET_WAITKIND_STOPPED:
3721 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3722 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
3725 case TARGET_WAITKIND_NO_HISTORY:
3727 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
3728 /* Reverse execution: target ran out of history info. */
3730 /* Pull the single step breakpoints out of the target. */
3731 if (singlestep_breakpoints_inserted_p)
3733 if (!ptid_equal (ecs->ptid, inferior_ptid))
3734 context_switch (ecs->ptid);
3735 remove_single_step_breakpoints ();
3736 singlestep_breakpoints_inserted_p = 0;
3738 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3739 print_no_history_reason ();
3740 stop_stepping (ecs);
3744 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3746 /* Do we need to clean up the state of a thread that has
3747 completed a displaced single-step? (Doing so usually affects
3748 the PC, so do it here, before we set stop_pc.) */
3749 displaced_step_fixup (ecs->ptid,
3750 ecs->event_thread->suspend.stop_signal);
3752 /* If we either finished a single-step or hit a breakpoint, but
3753 the user wanted this thread to be stopped, pretend we got a
3754 SIG0 (generic unsignaled stop). */
3756 if (ecs->event_thread->stop_requested
3757 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3758 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3761 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3765 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3766 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3767 struct cleanup *old_chain = save_inferior_ptid ();
3769 inferior_ptid = ecs->ptid;
3771 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3772 paddress (gdbarch, stop_pc));
3773 if (target_stopped_by_watchpoint ())
3777 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3779 if (target_stopped_data_address (¤t_target, &addr))
3780 fprintf_unfiltered (gdb_stdlog,
3781 "infrun: stopped data address = %s\n",
3782 paddress (gdbarch, addr));
3784 fprintf_unfiltered (gdb_stdlog,
3785 "infrun: (no data address available)\n");
3788 do_cleanups (old_chain);
3791 if (stepping_past_singlestep_breakpoint)
3793 gdb_assert (singlestep_breakpoints_inserted_p);
3794 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3795 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3797 stepping_past_singlestep_breakpoint = 0;
3799 /* We've either finished single-stepping past the single-step
3800 breakpoint, or stopped for some other reason. It would be nice if
3801 we could tell, but we can't reliably. */
3802 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3805 fprintf_unfiltered (gdb_stdlog,
3806 "infrun: stepping_past_"
3807 "singlestep_breakpoint\n");
3808 /* Pull the single step breakpoints out of the target. */
3809 if (!ptid_equal (ecs->ptid, inferior_ptid))
3810 context_switch (ecs->ptid);
3811 remove_single_step_breakpoints ();
3812 singlestep_breakpoints_inserted_p = 0;
3814 ecs->event_thread->control.trap_expected = 0;
3816 context_switch (saved_singlestep_ptid);
3817 if (deprecated_context_hook)
3818 deprecated_context_hook (pid_to_thread_id (saved_singlestep_ptid));
3820 resume (1, GDB_SIGNAL_0);
3821 prepare_to_wait (ecs);
3826 if (!ptid_equal (deferred_step_ptid, null_ptid))
3828 /* In non-stop mode, there's never a deferred_step_ptid set. */
3829 gdb_assert (!non_stop);
3831 /* If we stopped for some other reason than single-stepping, ignore
3832 the fact that we were supposed to switch back. */
3833 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3836 fprintf_unfiltered (gdb_stdlog,
3837 "infrun: handling deferred step\n");
3839 /* Pull the single step breakpoints out of the target. */
3840 if (singlestep_breakpoints_inserted_p)
3842 if (!ptid_equal (ecs->ptid, inferior_ptid))
3843 context_switch (ecs->ptid);
3844 remove_single_step_breakpoints ();
3845 singlestep_breakpoints_inserted_p = 0;
3848 ecs->event_thread->control.trap_expected = 0;
3850 context_switch (deferred_step_ptid);
3851 deferred_step_ptid = null_ptid;
3852 /* Suppress spurious "Switching to ..." message. */
3853 previous_inferior_ptid = inferior_ptid;
3855 resume (1, GDB_SIGNAL_0);
3856 prepare_to_wait (ecs);
3860 deferred_step_ptid = null_ptid;
3863 /* See if a thread hit a thread-specific breakpoint that was meant for
3864 another thread. If so, then step that thread past the breakpoint,
3867 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3869 int thread_hop_needed = 0;
3870 struct address_space *aspace =
3871 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3873 /* Check if a regular breakpoint has been hit before checking
3874 for a potential single step breakpoint. Otherwise, GDB will
3875 not see this breakpoint hit when stepping onto breakpoints. */
3876 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3878 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3879 thread_hop_needed = 1;
3881 else if (singlestep_breakpoints_inserted_p)
3883 /* We have not context switched yet, so this should be true
3884 no matter which thread hit the singlestep breakpoint. */
3885 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3887 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3889 target_pid_to_str (ecs->ptid));
3891 /* The call to in_thread_list is necessary because PTIDs sometimes
3892 change when we go from single-threaded to multi-threaded. If
3893 the singlestep_ptid is still in the list, assume that it is
3894 really different from ecs->ptid. */
3895 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3896 && in_thread_list (singlestep_ptid))
3898 /* If the PC of the thread we were trying to single-step
3899 has changed, discard this event (which we were going
3900 to ignore anyway), and pretend we saw that thread
3901 trap. This prevents us continuously moving the
3902 single-step breakpoint forward, one instruction at a
3903 time. If the PC has changed, then the thread we were
3904 trying to single-step has trapped or been signalled,
3905 but the event has not been reported to GDB yet.
3907 There might be some cases where this loses signal
3908 information, if a signal has arrived at exactly the
3909 same time that the PC changed, but this is the best
3910 we can do with the information available. Perhaps we
3911 should arrange to report all events for all threads
3912 when they stop, or to re-poll the remote looking for
3913 this particular thread (i.e. temporarily enable
3916 CORE_ADDR new_singlestep_pc
3917 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3919 if (new_singlestep_pc != singlestep_pc)
3921 enum gdb_signal stop_signal;
3924 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3925 " but expected thread advanced also\n");
3927 /* The current context still belongs to
3928 singlestep_ptid. Don't swap here, since that's
3929 the context we want to use. Just fudge our
3930 state and continue. */
3931 stop_signal = ecs->event_thread->suspend.stop_signal;
3932 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3933 ecs->ptid = singlestep_ptid;
3934 ecs->event_thread = find_thread_ptid (ecs->ptid);
3935 ecs->event_thread->suspend.stop_signal = stop_signal;
3936 stop_pc = new_singlestep_pc;
3941 fprintf_unfiltered (gdb_stdlog,
3942 "infrun: unexpected thread\n");
3944 thread_hop_needed = 1;
3945 stepping_past_singlestep_breakpoint = 1;
3946 saved_singlestep_ptid = singlestep_ptid;
3951 if (thread_hop_needed)
3953 struct regcache *thread_regcache;
3954 int remove_status = 0;
3957 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3959 /* Switch context before touching inferior memory, the
3960 previous thread may have exited. */
3961 if (!ptid_equal (inferior_ptid, ecs->ptid))
3962 context_switch (ecs->ptid);
3964 /* Saw a breakpoint, but it was hit by the wrong thread.
3967 if (singlestep_breakpoints_inserted_p)
3969 /* Pull the single step breakpoints out of the target. */
3970 remove_single_step_breakpoints ();
3971 singlestep_breakpoints_inserted_p = 0;
3974 /* If the arch can displace step, don't remove the
3976 thread_regcache = get_thread_regcache (ecs->ptid);
3977 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3978 remove_status = remove_breakpoints ();
3980 /* Did we fail to remove breakpoints? If so, try
3981 to set the PC past the bp. (There's at least
3982 one situation in which we can fail to remove
3983 the bp's: On HP-UX's that use ttrace, we can't
3984 change the address space of a vforking child
3985 process until the child exits (well, okay, not
3986 then either :-) or execs. */
3987 if (remove_status != 0)
3988 error (_("Cannot step over breakpoint hit in wrong thread"));
3993 /* Only need to require the next event from this
3994 thread in all-stop mode. */
3995 waiton_ptid = ecs->ptid;
3996 infwait_state = infwait_thread_hop_state;
3999 ecs->event_thread->stepping_over_breakpoint = 1;
4006 /* See if something interesting happened to the non-current thread. If
4007 so, then switch to that thread. */
4008 if (!ptid_equal (ecs->ptid, inferior_ptid))
4011 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
4013 context_switch (ecs->ptid);
4015 if (deprecated_context_hook)
4016 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
4019 /* At this point, get hold of the now-current thread's frame. */
4020 frame = get_current_frame ();
4021 gdbarch = get_frame_arch (frame);
4023 if (singlestep_breakpoints_inserted_p)
4025 /* Pull the single step breakpoints out of the target. */
4026 remove_single_step_breakpoints ();
4027 singlestep_breakpoints_inserted_p = 0;
4030 if (stepped_after_stopped_by_watchpoint)
4031 stopped_by_watchpoint = 0;
4033 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4035 /* If necessary, step over this watchpoint. We'll be back to display
4037 if (stopped_by_watchpoint
4038 && (target_have_steppable_watchpoint
4039 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4041 /* At this point, we are stopped at an instruction which has
4042 attempted to write to a piece of memory under control of
4043 a watchpoint. The instruction hasn't actually executed
4044 yet. If we were to evaluate the watchpoint expression
4045 now, we would get the old value, and therefore no change
4046 would seem to have occurred.
4048 In order to make watchpoints work `right', we really need
4049 to complete the memory write, and then evaluate the
4050 watchpoint expression. We do this by single-stepping the
4053 It may not be necessary to disable the watchpoint to stop over
4054 it. For example, the PA can (with some kernel cooperation)
4055 single step over a watchpoint without disabling the watchpoint.
4057 It is far more common to need to disable a watchpoint to step
4058 the inferior over it. If we have non-steppable watchpoints,
4059 we must disable the current watchpoint; it's simplest to
4060 disable all watchpoints and breakpoints. */
4063 if (!target_have_steppable_watchpoint)
4065 remove_breakpoints ();
4066 /* See comment in resume why we need to stop bypassing signals
4067 while breakpoints have been removed. */
4068 target_pass_signals (0, NULL);
4071 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
4072 target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0);
4073 waiton_ptid = ecs->ptid;
4074 if (target_have_steppable_watchpoint)
4075 infwait_state = infwait_step_watch_state;
4077 infwait_state = infwait_nonstep_watch_state;
4078 prepare_to_wait (ecs);
4082 ecs->event_thread->stepping_over_breakpoint = 0;
4083 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4084 ecs->event_thread->control.stop_step = 0;
4085 stop_print_frame = 1;
4086 stopped_by_random_signal = 0;
4088 /* Hide inlined functions starting here, unless we just performed stepi or
4089 nexti. After stepi and nexti, always show the innermost frame (not any
4090 inline function call sites). */
4091 if (ecs->event_thread->control.step_range_end != 1)
4093 struct address_space *aspace =
4094 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4096 /* skip_inline_frames is expensive, so we avoid it if we can
4097 determine that the address is one where functions cannot have
4098 been inlined. This improves performance with inferiors that
4099 load a lot of shared libraries, because the solib event
4100 breakpoint is defined as the address of a function (i.e. not
4101 inline). Note that we have to check the previous PC as well
4102 as the current one to catch cases when we have just
4103 single-stepped off a breakpoint prior to reinstating it.
4104 Note that we're assuming that the code we single-step to is
4105 not inline, but that's not definitive: there's nothing
4106 preventing the event breakpoint function from containing
4107 inlined code, and the single-step ending up there. If the
4108 user had set a breakpoint on that inlined code, the missing
4109 skip_inline_frames call would break things. Fortunately
4110 that's an extremely unlikely scenario. */
4111 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4112 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4113 && ecs->event_thread->control.trap_expected
4114 && pc_at_non_inline_function (aspace,
4115 ecs->event_thread->prev_pc,
4118 skip_inline_frames (ecs->ptid);
4120 /* Re-fetch current thread's frame in case that invalidated
4122 frame = get_current_frame ();
4123 gdbarch = get_frame_arch (frame);
4127 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4128 && ecs->event_thread->control.trap_expected
4129 && gdbarch_single_step_through_delay_p (gdbarch)
4130 && currently_stepping (ecs->event_thread))
4132 /* We're trying to step off a breakpoint. Turns out that we're
4133 also on an instruction that needs to be stepped multiple
4134 times before it's been fully executing. E.g., architectures
4135 with a delay slot. It needs to be stepped twice, once for
4136 the instruction and once for the delay slot. */
4137 int step_through_delay
4138 = gdbarch_single_step_through_delay (gdbarch, frame);
4140 if (debug_infrun && step_through_delay)
4141 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4142 if (ecs->event_thread->control.step_range_end == 0
4143 && step_through_delay)
4145 /* The user issued a continue when stopped at a breakpoint.
4146 Set up for another trap and get out of here. */
4147 ecs->event_thread->stepping_over_breakpoint = 1;
4151 else if (step_through_delay)
4153 /* The user issued a step when stopped at a breakpoint.
4154 Maybe we should stop, maybe we should not - the delay
4155 slot *might* correspond to a line of source. In any
4156 case, don't decide that here, just set
4157 ecs->stepping_over_breakpoint, making sure we
4158 single-step again before breakpoints are re-inserted. */
4159 ecs->event_thread->stepping_over_breakpoint = 1;
4163 /* Look at the cause of the stop, and decide what to do.
4164 The alternatives are:
4165 1) stop_stepping and return; to really stop and return to the debugger,
4166 2) keep_going and return to start up again
4167 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
4168 3) set ecs->random_signal to 1, and the decision between 1 and 2
4169 will be made according to the signal handling tables. */
4171 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4175 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4176 stop_print_frame = 0;
4177 stop_stepping (ecs);
4181 /* This is originated from start_remote(), start_inferior() and
4182 shared libraries hook functions. */
4183 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4186 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4187 stop_stepping (ecs);
4191 /* This originates from attach_command(). We need to overwrite
4192 the stop_signal here, because some kernels don't ignore a
4193 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4194 See more comments in inferior.h. On the other hand, if we
4195 get a non-SIGSTOP, report it to the user - assume the backend
4196 will handle the SIGSTOP if it should show up later.
4198 Also consider that the attach is complete when we see a
4199 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4200 target extended-remote report it instead of a SIGSTOP
4201 (e.g. gdbserver). We already rely on SIGTRAP being our
4202 signal, so this is no exception.
4204 Also consider that the attach is complete when we see a
4205 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4206 the target to stop all threads of the inferior, in case the
4207 low level attach operation doesn't stop them implicitly. If
4208 they weren't stopped implicitly, then the stub will report a
4209 GDB_SIGNAL_0, meaning: stopped for no particular reason
4210 other than GDB's request. */
4211 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4212 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4213 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4214 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4216 stop_stepping (ecs);
4217 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4221 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4222 handles this event. */
4223 ecs->event_thread->control.stop_bpstat
4224 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4225 stop_pc, ecs->ptid, &ecs->ws);
4227 /* Following in case break condition called a
4229 stop_print_frame = 1;
4231 /* This is where we handle "moribund" watchpoints. Unlike
4232 software breakpoints traps, hardware watchpoint traps are
4233 always distinguishable from random traps. If no high-level
4234 watchpoint is associated with the reported stop data address
4235 anymore, then the bpstat does not explain the signal ---
4236 simply make sure to ignore it if `stopped_by_watchpoint' is
4240 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4241 && (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4243 == BPSTAT_SIGNAL_NO)
4244 && stopped_by_watchpoint)
4245 fprintf_unfiltered (gdb_stdlog,
4246 "infrun: no user watchpoint explains "
4247 "watchpoint SIGTRAP, ignoring\n");
4249 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4250 at one stage in the past included checks for an inferior
4251 function call's call dummy's return breakpoint. The original
4252 comment, that went with the test, read:
4254 ``End of a stack dummy. Some systems (e.g. Sony news) give
4255 another signal besides SIGTRAP, so check here as well as
4258 If someone ever tries to get call dummys on a
4259 non-executable stack to work (where the target would stop
4260 with something like a SIGSEGV), then those tests might need
4261 to be re-instated. Given, however, that the tests were only
4262 enabled when momentary breakpoints were not being used, I
4263 suspect that it won't be the case.
4265 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4266 be necessary for call dummies on a non-executable stack on
4269 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4271 = !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4273 != BPSTAT_SIGNAL_NO)
4274 || stopped_by_watchpoint
4275 || ecs->event_thread->control.trap_expected
4276 || (ecs->event_thread->control.step_range_end
4277 && (ecs->event_thread->control.step_resume_breakpoint
4281 enum bpstat_signal_value sval;
4283 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4284 ecs->event_thread->suspend.stop_signal);
4285 ecs->random_signal = (sval == BPSTAT_SIGNAL_NO);
4287 if (sval == BPSTAT_SIGNAL_HIDE)
4288 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
4291 /* For the program's own signals, act according to
4292 the signal handling tables. */
4294 if (ecs->random_signal)
4296 /* Signal not for debugging purposes. */
4298 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4299 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
4302 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
4303 gdb_signal_to_symbol_string (stop_signal));
4305 stopped_by_random_signal = 1;
4307 if (signal_print[ecs->event_thread->suspend.stop_signal])
4310 target_terminal_ours_for_output ();
4311 print_signal_received_reason
4312 (ecs->event_thread->suspend.stop_signal);
4314 /* Always stop on signals if we're either just gaining control
4315 of the program, or the user explicitly requested this thread
4316 to remain stopped. */
4317 if (stop_soon != NO_STOP_QUIETLY
4318 || ecs->event_thread->stop_requested
4320 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4322 stop_stepping (ecs);
4325 /* If not going to stop, give terminal back
4326 if we took it away. */
4328 target_terminal_inferior ();
4330 /* Clear the signal if it should not be passed. */
4331 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4332 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4334 if (ecs->event_thread->prev_pc == stop_pc
4335 && ecs->event_thread->control.trap_expected
4336 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4338 /* We were just starting a new sequence, attempting to
4339 single-step off of a breakpoint and expecting a SIGTRAP.
4340 Instead this signal arrives. This signal will take us out
4341 of the stepping range so GDB needs to remember to, when
4342 the signal handler returns, resume stepping off that
4344 /* To simplify things, "continue" is forced to use the same
4345 code paths as single-step - set a breakpoint at the
4346 signal return address and then, once hit, step off that
4349 fprintf_unfiltered (gdb_stdlog,
4350 "infrun: signal arrived while stepping over "
4353 insert_hp_step_resume_breakpoint_at_frame (frame);
4354 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4355 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4356 ecs->event_thread->control.trap_expected = 0;
4361 if (ecs->event_thread->control.step_range_end != 0
4362 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4363 && pc_in_thread_step_range (stop_pc, ecs->event_thread)
4364 && frame_id_eq (get_stack_frame_id (frame),
4365 ecs->event_thread->control.step_stack_frame_id)
4366 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4368 /* The inferior is about to take a signal that will take it
4369 out of the single step range. Set a breakpoint at the
4370 current PC (which is presumably where the signal handler
4371 will eventually return) and then allow the inferior to
4374 Note that this is only needed for a signal delivered
4375 while in the single-step range. Nested signals aren't a
4376 problem as they eventually all return. */
4378 fprintf_unfiltered (gdb_stdlog,
4379 "infrun: signal may take us out of "
4380 "single-step range\n");
4382 insert_hp_step_resume_breakpoint_at_frame (frame);
4383 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4384 ecs->event_thread->control.trap_expected = 0;
4389 /* Note: step_resume_breakpoint may be non-NULL. This occures
4390 when either there's a nested signal, or when there's a
4391 pending signal enabled just as the signal handler returns
4392 (leaving the inferior at the step-resume-breakpoint without
4393 actually executing it). Either way continue until the
4394 breakpoint is really hit. */
4396 if (!switch_back_to_stepped_thread (ecs))
4399 fprintf_unfiltered (gdb_stdlog,
4400 "infrun: random signal, keep going\n");
4408 /* Handle cases caused by hitting a breakpoint. */
4410 CORE_ADDR jmp_buf_pc;
4411 struct bpstat_what what;
4413 process_event_stop_test:
4415 /* Re-fetch current thread's frame in case we did a
4416 "goto process_event_stop_test" above. */
4417 frame = get_current_frame ();
4418 gdbarch = get_frame_arch (frame);
4420 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4422 if (what.call_dummy)
4424 stop_stack_dummy = what.call_dummy;
4427 /* If we hit an internal event that triggers symbol changes, the
4428 current frame will be invalidated within bpstat_what (e.g.,
4429 if we hit an internal solib event). Re-fetch it. */
4430 frame = get_current_frame ();
4431 gdbarch = get_frame_arch (frame);
4433 switch (what.main_action)
4435 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4436 /* If we hit the breakpoint at longjmp while stepping, we
4437 install a momentary breakpoint at the target of the
4441 fprintf_unfiltered (gdb_stdlog,
4442 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4444 ecs->event_thread->stepping_over_breakpoint = 1;
4446 if (what.is_longjmp)
4448 struct value *arg_value;
4450 /* If we set the longjmp breakpoint via a SystemTap
4451 probe, then use it to extract the arguments. The
4452 destination PC is the third argument to the
4454 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4456 jmp_buf_pc = value_as_address (arg_value);
4457 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4458 || !gdbarch_get_longjmp_target (gdbarch,
4459 frame, &jmp_buf_pc))
4462 fprintf_unfiltered (gdb_stdlog,
4463 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4464 "(!gdbarch_get_longjmp_target)\n");
4469 /* Insert a breakpoint at resume address. */
4470 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4473 check_exception_resume (ecs, frame);
4477 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4479 struct frame_info *init_frame;
4481 /* There are several cases to consider.
4483 1. The initiating frame no longer exists. In this case
4484 we must stop, because the exception or longjmp has gone
4487 2. The initiating frame exists, and is the same as the
4488 current frame. We stop, because the exception or
4489 longjmp has been caught.
4491 3. The initiating frame exists and is different from
4492 the current frame. This means the exception or longjmp
4493 has been caught beneath the initiating frame, so keep
4496 4. longjmp breakpoint has been placed just to protect
4497 against stale dummy frames and user is not interested
4498 in stopping around longjmps. */
4501 fprintf_unfiltered (gdb_stdlog,
4502 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4504 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4506 delete_exception_resume_breakpoint (ecs->event_thread);
4508 if (what.is_longjmp)
4510 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
4512 if (!frame_id_p (ecs->event_thread->initiating_frame))
4520 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4524 struct frame_id current_id
4525 = get_frame_id (get_current_frame ());
4526 if (frame_id_eq (current_id,
4527 ecs->event_thread->initiating_frame))
4529 /* Case 2. Fall through. */
4539 /* For Cases 1 and 2, remove the step-resume breakpoint,
4541 delete_step_resume_breakpoint (ecs->event_thread);
4543 ecs->event_thread->control.stop_step = 1;
4544 print_end_stepping_range_reason ();
4545 stop_stepping (ecs);
4549 case BPSTAT_WHAT_SINGLE:
4551 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4552 ecs->event_thread->stepping_over_breakpoint = 1;
4553 /* Still need to check other stuff, at least the case where
4554 we are stepping and step out of the right range. */
4557 case BPSTAT_WHAT_STEP_RESUME:
4559 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4561 delete_step_resume_breakpoint (ecs->event_thread);
4562 if (ecs->event_thread->control.proceed_to_finish
4563 && execution_direction == EXEC_REVERSE)
4565 struct thread_info *tp = ecs->event_thread;
4567 /* We are finishing a function in reverse, and just hit
4568 the step-resume breakpoint at the start address of
4569 the function, and we're almost there -- just need to
4570 back up by one more single-step, which should take us
4571 back to the function call. */
4572 tp->control.step_range_start = tp->control.step_range_end = 1;
4576 fill_in_stop_func (gdbarch, ecs);
4577 if (stop_pc == ecs->stop_func_start
4578 && execution_direction == EXEC_REVERSE)
4580 /* We are stepping over a function call in reverse, and
4581 just hit the step-resume breakpoint at the start
4582 address of the function. Go back to single-stepping,
4583 which should take us back to the function call. */
4584 ecs->event_thread->stepping_over_breakpoint = 1;
4590 case BPSTAT_WHAT_STOP_NOISY:
4592 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4593 stop_print_frame = 1;
4595 /* We are about to nuke the step_resume_breakpointt via the
4596 cleanup chain, so no need to worry about it here. */
4598 stop_stepping (ecs);
4601 case BPSTAT_WHAT_STOP_SILENT:
4603 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4604 stop_print_frame = 0;
4606 /* We are about to nuke the step_resume_breakpoin via the
4607 cleanup chain, so no need to worry about it here. */
4609 stop_stepping (ecs);
4612 case BPSTAT_WHAT_HP_STEP_RESUME:
4614 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4616 delete_step_resume_breakpoint (ecs->event_thread);
4617 if (ecs->event_thread->step_after_step_resume_breakpoint)
4619 /* Back when the step-resume breakpoint was inserted, we
4620 were trying to single-step off a breakpoint. Go back
4622 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4623 ecs->event_thread->stepping_over_breakpoint = 1;
4629 case BPSTAT_WHAT_KEEP_CHECKING:
4634 /* We come here if we hit a breakpoint but should not
4635 stop for it. Possibly we also were stepping
4636 and should stop for that. So fall through and
4637 test for stepping. But, if not stepping,
4640 /* In all-stop mode, if we're currently stepping but have stopped in
4641 some other thread, we need to switch back to the stepped thread. */
4642 if (switch_back_to_stepped_thread (ecs))
4645 if (ecs->event_thread->control.step_resume_breakpoint)
4648 fprintf_unfiltered (gdb_stdlog,
4649 "infrun: step-resume breakpoint is inserted\n");
4651 /* Having a step-resume breakpoint overrides anything
4652 else having to do with stepping commands until
4653 that breakpoint is reached. */
4658 if (ecs->event_thread->control.step_range_end == 0)
4661 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4662 /* Likewise if we aren't even stepping. */
4667 /* Re-fetch current thread's frame in case the code above caused
4668 the frame cache to be re-initialized, making our FRAME variable
4669 a dangling pointer. */
4670 frame = get_current_frame ();
4671 gdbarch = get_frame_arch (frame);
4672 fill_in_stop_func (gdbarch, ecs);
4674 /* If stepping through a line, keep going if still within it.
4676 Note that step_range_end is the address of the first instruction
4677 beyond the step range, and NOT the address of the last instruction
4680 Note also that during reverse execution, we may be stepping
4681 through a function epilogue and therefore must detect when
4682 the current-frame changes in the middle of a line. */
4684 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
4685 && (execution_direction != EXEC_REVERSE
4686 || frame_id_eq (get_frame_id (frame),
4687 ecs->event_thread->control.step_frame_id)))
4691 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4692 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4693 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4695 /* Tentatively re-enable range stepping; `resume' disables it if
4696 necessary (e.g., if we're stepping over a breakpoint or we
4697 have software watchpoints). */
4698 ecs->event_thread->control.may_range_step = 1;
4700 /* When stepping backward, stop at beginning of line range
4701 (unless it's the function entry point, in which case
4702 keep going back to the call point). */
4703 if (stop_pc == ecs->event_thread->control.step_range_start
4704 && stop_pc != ecs->stop_func_start
4705 && execution_direction == EXEC_REVERSE)
4707 ecs->event_thread->control.stop_step = 1;
4708 print_end_stepping_range_reason ();
4709 stop_stepping (ecs);
4717 /* We stepped out of the stepping range. */
4719 /* If we are stepping at the source level and entered the runtime
4720 loader dynamic symbol resolution code...
4722 EXEC_FORWARD: we keep on single stepping until we exit the run
4723 time loader code and reach the callee's address.
4725 EXEC_REVERSE: we've already executed the callee (backward), and
4726 the runtime loader code is handled just like any other
4727 undebuggable function call. Now we need only keep stepping
4728 backward through the trampoline code, and that's handled further
4729 down, so there is nothing for us to do here. */
4731 if (execution_direction != EXEC_REVERSE
4732 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4733 && in_solib_dynsym_resolve_code (stop_pc))
4735 CORE_ADDR pc_after_resolver =
4736 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4739 fprintf_unfiltered (gdb_stdlog,
4740 "infrun: stepped into dynsym resolve code\n");
4742 if (pc_after_resolver)
4744 /* Set up a step-resume breakpoint at the address
4745 indicated by SKIP_SOLIB_RESOLVER. */
4746 struct symtab_and_line sr_sal;
4749 sr_sal.pc = pc_after_resolver;
4750 sr_sal.pspace = get_frame_program_space (frame);
4752 insert_step_resume_breakpoint_at_sal (gdbarch,
4753 sr_sal, null_frame_id);
4760 if (ecs->event_thread->control.step_range_end != 1
4761 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4762 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4763 && get_frame_type (frame) == SIGTRAMP_FRAME)
4766 fprintf_unfiltered (gdb_stdlog,
4767 "infrun: stepped into signal trampoline\n");
4768 /* The inferior, while doing a "step" or "next", has ended up in
4769 a signal trampoline (either by a signal being delivered or by
4770 the signal handler returning). Just single-step until the
4771 inferior leaves the trampoline (either by calling the handler
4777 /* If we're in the return path from a shared library trampoline,
4778 we want to proceed through the trampoline when stepping. */
4779 /* macro/2012-04-25: This needs to come before the subroutine
4780 call check below as on some targets return trampolines look
4781 like subroutine calls (MIPS16 return thunks). */
4782 if (gdbarch_in_solib_return_trampoline (gdbarch,
4783 stop_pc, ecs->stop_func_name)
4784 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4786 /* Determine where this trampoline returns. */
4787 CORE_ADDR real_stop_pc;
4789 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4792 fprintf_unfiltered (gdb_stdlog,
4793 "infrun: stepped into solib return tramp\n");
4795 /* Only proceed through if we know where it's going. */
4798 /* And put the step-breakpoint there and go until there. */
4799 struct symtab_and_line sr_sal;
4801 init_sal (&sr_sal); /* initialize to zeroes */
4802 sr_sal.pc = real_stop_pc;
4803 sr_sal.section = find_pc_overlay (sr_sal.pc);
4804 sr_sal.pspace = get_frame_program_space (frame);
4806 /* Do not specify what the fp should be when we stop since
4807 on some machines the prologue is where the new fp value
4809 insert_step_resume_breakpoint_at_sal (gdbarch,
4810 sr_sal, null_frame_id);
4812 /* Restart without fiddling with the step ranges or
4819 /* Check for subroutine calls. The check for the current frame
4820 equalling the step ID is not necessary - the check of the
4821 previous frame's ID is sufficient - but it is a common case and
4822 cheaper than checking the previous frame's ID.
4824 NOTE: frame_id_eq will never report two invalid frame IDs as
4825 being equal, so to get into this block, both the current and
4826 previous frame must have valid frame IDs. */
4827 /* The outer_frame_id check is a heuristic to detect stepping
4828 through startup code. If we step over an instruction which
4829 sets the stack pointer from an invalid value to a valid value,
4830 we may detect that as a subroutine call from the mythical
4831 "outermost" function. This could be fixed by marking
4832 outermost frames as !stack_p,code_p,special_p. Then the
4833 initial outermost frame, before sp was valid, would
4834 have code_addr == &_start. See the comment in frame_id_eq
4836 if (!frame_id_eq (get_stack_frame_id (frame),
4837 ecs->event_thread->control.step_stack_frame_id)
4838 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4839 ecs->event_thread->control.step_stack_frame_id)
4840 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
4842 || step_start_function != find_pc_function (stop_pc))))
4844 CORE_ADDR real_stop_pc;
4847 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4849 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
4850 || ((ecs->event_thread->control.step_range_end == 1)
4851 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4852 ecs->stop_func_start)))
4854 /* I presume that step_over_calls is only 0 when we're
4855 supposed to be stepping at the assembly language level
4856 ("stepi"). Just stop. */
4857 /* Also, maybe we just did a "nexti" inside a prolog, so we
4858 thought it was a subroutine call but it was not. Stop as
4860 /* And this works the same backward as frontward. MVS */
4861 ecs->event_thread->control.stop_step = 1;
4862 print_end_stepping_range_reason ();
4863 stop_stepping (ecs);
4867 /* Reverse stepping through solib trampolines. */
4869 if (execution_direction == EXEC_REVERSE
4870 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
4871 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4872 || (ecs->stop_func_start == 0
4873 && in_solib_dynsym_resolve_code (stop_pc))))
4875 /* Any solib trampoline code can be handled in reverse
4876 by simply continuing to single-step. We have already
4877 executed the solib function (backwards), and a few
4878 steps will take us back through the trampoline to the
4884 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4886 /* We're doing a "next".
4888 Normal (forward) execution: set a breakpoint at the
4889 callee's return address (the address at which the caller
4892 Reverse (backward) execution. set the step-resume
4893 breakpoint at the start of the function that we just
4894 stepped into (backwards), and continue to there. When we
4895 get there, we'll need to single-step back to the caller. */
4897 if (execution_direction == EXEC_REVERSE)
4899 /* If we're already at the start of the function, we've either
4900 just stepped backward into a single instruction function,
4901 or stepped back out of a signal handler to the first instruction
4902 of the function. Just keep going, which will single-step back
4904 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
4906 struct symtab_and_line sr_sal;
4908 /* Normal function call return (static or dynamic). */
4910 sr_sal.pc = ecs->stop_func_start;
4911 sr_sal.pspace = get_frame_program_space (frame);
4912 insert_step_resume_breakpoint_at_sal (gdbarch,
4913 sr_sal, null_frame_id);
4917 insert_step_resume_breakpoint_at_caller (frame);
4923 /* If we are in a function call trampoline (a stub between the
4924 calling routine and the real function), locate the real
4925 function. That's what tells us (a) whether we want to step
4926 into it at all, and (b) what prologue we want to run to the
4927 end of, if we do step into it. */
4928 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4929 if (real_stop_pc == 0)
4930 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4931 if (real_stop_pc != 0)
4932 ecs->stop_func_start = real_stop_pc;
4934 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4936 struct symtab_and_line sr_sal;
4939 sr_sal.pc = ecs->stop_func_start;
4940 sr_sal.pspace = get_frame_program_space (frame);
4942 insert_step_resume_breakpoint_at_sal (gdbarch,
4943 sr_sal, null_frame_id);
4948 /* If we have line number information for the function we are
4949 thinking of stepping into and the function isn't on the skip
4952 If there are several symtabs at that PC (e.g. with include
4953 files), just want to know whether *any* of them have line
4954 numbers. find_pc_line handles this. */
4956 struct symtab_and_line tmp_sal;
4958 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4959 if (tmp_sal.line != 0
4960 && !function_name_is_marked_for_skip (ecs->stop_func_name,
4963 if (execution_direction == EXEC_REVERSE)
4964 handle_step_into_function_backward (gdbarch, ecs);
4966 handle_step_into_function (gdbarch, ecs);
4971 /* If we have no line number and the step-stop-if-no-debug is
4972 set, we stop the step so that the user has a chance to switch
4973 in assembly mode. */
4974 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4975 && step_stop_if_no_debug)
4977 ecs->event_thread->control.stop_step = 1;
4978 print_end_stepping_range_reason ();
4979 stop_stepping (ecs);
4983 if (execution_direction == EXEC_REVERSE)
4985 /* If we're already at the start of the function, we've either just
4986 stepped backward into a single instruction function without line
4987 number info, or stepped back out of a signal handler to the first
4988 instruction of the function without line number info. Just keep
4989 going, which will single-step back to the caller. */
4990 if (ecs->stop_func_start != stop_pc)
4992 /* Set a breakpoint at callee's start address.
4993 From there we can step once and be back in the caller. */
4994 struct symtab_and_line sr_sal;
4997 sr_sal.pc = ecs->stop_func_start;
4998 sr_sal.pspace = get_frame_program_space (frame);
4999 insert_step_resume_breakpoint_at_sal (gdbarch,
5000 sr_sal, null_frame_id);
5004 /* Set a breakpoint at callee's return address (the address
5005 at which the caller will resume). */
5006 insert_step_resume_breakpoint_at_caller (frame);
5012 /* Reverse stepping through solib trampolines. */
5014 if (execution_direction == EXEC_REVERSE
5015 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5017 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5018 || (ecs->stop_func_start == 0
5019 && in_solib_dynsym_resolve_code (stop_pc)))
5021 /* Any solib trampoline code can be handled in reverse
5022 by simply continuing to single-step. We have already
5023 executed the solib function (backwards), and a few
5024 steps will take us back through the trampoline to the
5029 else if (in_solib_dynsym_resolve_code (stop_pc))
5031 /* Stepped backward into the solib dynsym resolver.
5032 Set a breakpoint at its start and continue, then
5033 one more step will take us out. */
5034 struct symtab_and_line sr_sal;
5037 sr_sal.pc = ecs->stop_func_start;
5038 sr_sal.pspace = get_frame_program_space (frame);
5039 insert_step_resume_breakpoint_at_sal (gdbarch,
5040 sr_sal, null_frame_id);
5046 stop_pc_sal = find_pc_line (stop_pc, 0);
5048 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5049 the trampoline processing logic, however, there are some trampolines
5050 that have no names, so we should do trampoline handling first. */
5051 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5052 && ecs->stop_func_name == NULL
5053 && stop_pc_sal.line == 0)
5056 fprintf_unfiltered (gdb_stdlog,
5057 "infrun: stepped into undebuggable function\n");
5059 /* The inferior just stepped into, or returned to, an
5060 undebuggable function (where there is no debugging information
5061 and no line number corresponding to the address where the
5062 inferior stopped). Since we want to skip this kind of code,
5063 we keep going until the inferior returns from this
5064 function - unless the user has asked us not to (via
5065 set step-mode) or we no longer know how to get back
5066 to the call site. */
5067 if (step_stop_if_no_debug
5068 || !frame_id_p (frame_unwind_caller_id (frame)))
5070 /* If we have no line number and the step-stop-if-no-debug
5071 is set, we stop the step so that the user has a chance to
5072 switch in assembly mode. */
5073 ecs->event_thread->control.stop_step = 1;
5074 print_end_stepping_range_reason ();
5075 stop_stepping (ecs);
5080 /* Set a breakpoint at callee's return address (the address
5081 at which the caller will resume). */
5082 insert_step_resume_breakpoint_at_caller (frame);
5088 if (ecs->event_thread->control.step_range_end == 1)
5090 /* It is stepi or nexti. We always want to stop stepping after
5093 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5094 ecs->event_thread->control.stop_step = 1;
5095 print_end_stepping_range_reason ();
5096 stop_stepping (ecs);
5100 if (stop_pc_sal.line == 0)
5102 /* We have no line number information. That means to stop
5103 stepping (does this always happen right after one instruction,
5104 when we do "s" in a function with no line numbers,
5105 or can this happen as a result of a return or longjmp?). */
5107 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5108 ecs->event_thread->control.stop_step = 1;
5109 print_end_stepping_range_reason ();
5110 stop_stepping (ecs);
5114 /* Look for "calls" to inlined functions, part one. If the inline
5115 frame machinery detected some skipped call sites, we have entered
5116 a new inline function. */
5118 if (frame_id_eq (get_frame_id (get_current_frame ()),
5119 ecs->event_thread->control.step_frame_id)
5120 && inline_skipped_frames (ecs->ptid))
5122 struct symtab_and_line call_sal;
5125 fprintf_unfiltered (gdb_stdlog,
5126 "infrun: stepped into inlined function\n");
5128 find_frame_sal (get_current_frame (), &call_sal);
5130 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5132 /* For "step", we're going to stop. But if the call site
5133 for this inlined function is on the same source line as
5134 we were previously stepping, go down into the function
5135 first. Otherwise stop at the call site. */
5137 if (call_sal.line == ecs->event_thread->current_line
5138 && call_sal.symtab == ecs->event_thread->current_symtab)
5139 step_into_inline_frame (ecs->ptid);
5141 ecs->event_thread->control.stop_step = 1;
5142 print_end_stepping_range_reason ();
5143 stop_stepping (ecs);
5148 /* For "next", we should stop at the call site if it is on a
5149 different source line. Otherwise continue through the
5150 inlined function. */
5151 if (call_sal.line == ecs->event_thread->current_line
5152 && call_sal.symtab == ecs->event_thread->current_symtab)
5156 ecs->event_thread->control.stop_step = 1;
5157 print_end_stepping_range_reason ();
5158 stop_stepping (ecs);
5164 /* Look for "calls" to inlined functions, part two. If we are still
5165 in the same real function we were stepping through, but we have
5166 to go further up to find the exact frame ID, we are stepping
5167 through a more inlined call beyond its call site. */
5169 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5170 && !frame_id_eq (get_frame_id (get_current_frame ()),
5171 ecs->event_thread->control.step_frame_id)
5172 && stepped_in_from (get_current_frame (),
5173 ecs->event_thread->control.step_frame_id))
5176 fprintf_unfiltered (gdb_stdlog,
5177 "infrun: stepping through inlined function\n");
5179 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5183 ecs->event_thread->control.stop_step = 1;
5184 print_end_stepping_range_reason ();
5185 stop_stepping (ecs);
5190 if ((stop_pc == stop_pc_sal.pc)
5191 && (ecs->event_thread->current_line != stop_pc_sal.line
5192 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5194 /* We are at the start of a different line. So stop. Note that
5195 we don't stop if we step into the middle of a different line.
5196 That is said to make things like for (;;) statements work
5199 fprintf_unfiltered (gdb_stdlog,
5200 "infrun: stepped to a different line\n");
5201 ecs->event_thread->control.stop_step = 1;
5202 print_end_stepping_range_reason ();
5203 stop_stepping (ecs);
5207 /* We aren't done stepping.
5209 Optimize by setting the stepping range to the line.
5210 (We might not be in the original line, but if we entered a
5211 new line in mid-statement, we continue stepping. This makes
5212 things like for(;;) statements work better.) */
5214 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5215 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5216 ecs->event_thread->control.may_range_step = 1;
5217 set_step_info (frame, stop_pc_sal);
5220 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5224 /* In all-stop mode, if we're currently stepping but have stopped in
5225 some other thread, we may need to switch back to the stepped
5226 thread. Returns true we set the inferior running, false if we left
5227 it stopped (and the event needs further processing). */
5230 switch_back_to_stepped_thread (struct execution_control_state *ecs)
5234 struct thread_info *tp;
5236 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
5240 /* However, if the current thread is blocked on some internal
5241 breakpoint, and we simply need to step over that breakpoint
5242 to get it going again, do that first. */
5243 if ((ecs->event_thread->control.trap_expected
5244 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5245 || ecs->event_thread->stepping_over_breakpoint)
5251 /* If the stepping thread exited, then don't try to switch
5252 back and resume it, which could fail in several different
5253 ways depending on the target. Instead, just keep going.
5255 We can find a stepping dead thread in the thread list in
5258 - The target supports thread exit events, and when the
5259 target tries to delete the thread from the thread list,
5260 inferior_ptid pointed at the exiting thread. In such
5261 case, calling delete_thread does not really remove the
5262 thread from the list; instead, the thread is left listed,
5263 with 'exited' state.
5265 - The target's debug interface does not support thread
5266 exit events, and so we have no idea whatsoever if the
5267 previously stepping thread is still alive. For that
5268 reason, we need to synchronously query the target
5270 if (is_exited (tp->ptid)
5271 || !target_thread_alive (tp->ptid))
5274 fprintf_unfiltered (gdb_stdlog,
5275 "infrun: not switching back to "
5276 "stepped thread, it has vanished\n");
5278 delete_thread (tp->ptid);
5283 /* Otherwise, we no longer expect a trap in the current thread.
5284 Clear the trap_expected flag before switching back -- this is
5285 what keep_going would do as well, if we called it. */
5286 ecs->event_thread->control.trap_expected = 0;
5289 fprintf_unfiltered (gdb_stdlog,
5290 "infrun: switching back to stepped thread\n");
5292 ecs->event_thread = tp;
5293 ecs->ptid = tp->ptid;
5294 context_switch (ecs->ptid);
5302 /* Is thread TP in the middle of single-stepping? */
5305 currently_stepping (struct thread_info *tp)
5307 return ((tp->control.step_range_end
5308 && tp->control.step_resume_breakpoint == NULL)
5309 || tp->control.trap_expected
5310 || bpstat_should_step ());
5313 /* Returns true if any thread *but* the one passed in "data" is in the
5314 middle of stepping or of handling a "next". */
5317 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
5322 return (tp->control.step_range_end
5323 || tp->control.trap_expected);
5326 /* Inferior has stepped into a subroutine call with source code that
5327 we should not step over. Do step to the first line of code in
5331 handle_step_into_function (struct gdbarch *gdbarch,
5332 struct execution_control_state *ecs)
5335 struct symtab_and_line stop_func_sal, sr_sal;
5337 fill_in_stop_func (gdbarch, ecs);
5339 s = find_pc_symtab (stop_pc);
5340 if (s && s->language != language_asm)
5341 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5342 ecs->stop_func_start);
5344 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5345 /* Use the step_resume_break to step until the end of the prologue,
5346 even if that involves jumps (as it seems to on the vax under
5348 /* If the prologue ends in the middle of a source line, continue to
5349 the end of that source line (if it is still within the function).
5350 Otherwise, just go to end of prologue. */
5351 if (stop_func_sal.end
5352 && stop_func_sal.pc != ecs->stop_func_start
5353 && stop_func_sal.end < ecs->stop_func_end)
5354 ecs->stop_func_start = stop_func_sal.end;
5356 /* Architectures which require breakpoint adjustment might not be able
5357 to place a breakpoint at the computed address. If so, the test
5358 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5359 ecs->stop_func_start to an address at which a breakpoint may be
5360 legitimately placed.
5362 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5363 made, GDB will enter an infinite loop when stepping through
5364 optimized code consisting of VLIW instructions which contain
5365 subinstructions corresponding to different source lines. On
5366 FR-V, it's not permitted to place a breakpoint on any but the
5367 first subinstruction of a VLIW instruction. When a breakpoint is
5368 set, GDB will adjust the breakpoint address to the beginning of
5369 the VLIW instruction. Thus, we need to make the corresponding
5370 adjustment here when computing the stop address. */
5372 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5374 ecs->stop_func_start
5375 = gdbarch_adjust_breakpoint_address (gdbarch,
5376 ecs->stop_func_start);
5379 if (ecs->stop_func_start == stop_pc)
5381 /* We are already there: stop now. */
5382 ecs->event_thread->control.stop_step = 1;
5383 print_end_stepping_range_reason ();
5384 stop_stepping (ecs);
5389 /* Put the step-breakpoint there and go until there. */
5390 init_sal (&sr_sal); /* initialize to zeroes */
5391 sr_sal.pc = ecs->stop_func_start;
5392 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5393 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5395 /* Do not specify what the fp should be when we stop since on
5396 some machines the prologue is where the new fp value is
5398 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5400 /* And make sure stepping stops right away then. */
5401 ecs->event_thread->control.step_range_end
5402 = ecs->event_thread->control.step_range_start;
5407 /* Inferior has stepped backward into a subroutine call with source
5408 code that we should not step over. Do step to the beginning of the
5409 last line of code in it. */
5412 handle_step_into_function_backward (struct gdbarch *gdbarch,
5413 struct execution_control_state *ecs)
5416 struct symtab_and_line stop_func_sal;
5418 fill_in_stop_func (gdbarch, ecs);
5420 s = find_pc_symtab (stop_pc);
5421 if (s && s->language != language_asm)
5422 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5423 ecs->stop_func_start);
5425 stop_func_sal = find_pc_line (stop_pc, 0);
5427 /* OK, we're just going to keep stepping here. */
5428 if (stop_func_sal.pc == stop_pc)
5430 /* We're there already. Just stop stepping now. */
5431 ecs->event_thread->control.stop_step = 1;
5432 print_end_stepping_range_reason ();
5433 stop_stepping (ecs);
5437 /* Else just reset the step range and keep going.
5438 No step-resume breakpoint, they don't work for
5439 epilogues, which can have multiple entry paths. */
5440 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5441 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5447 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5448 This is used to both functions and to skip over code. */
5451 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5452 struct symtab_and_line sr_sal,
5453 struct frame_id sr_id,
5454 enum bptype sr_type)
5456 /* There should never be more than one step-resume or longjmp-resume
5457 breakpoint per thread, so we should never be setting a new
5458 step_resume_breakpoint when one is already active. */
5459 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5460 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5463 fprintf_unfiltered (gdb_stdlog,
5464 "infrun: inserting step-resume breakpoint at %s\n",
5465 paddress (gdbarch, sr_sal.pc));
5467 inferior_thread ()->control.step_resume_breakpoint
5468 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5472 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5473 struct symtab_and_line sr_sal,
5474 struct frame_id sr_id)
5476 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5481 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5482 This is used to skip a potential signal handler.
5484 This is called with the interrupted function's frame. The signal
5485 handler, when it returns, will resume the interrupted function at
5489 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5491 struct symtab_and_line sr_sal;
5492 struct gdbarch *gdbarch;
5494 gdb_assert (return_frame != NULL);
5495 init_sal (&sr_sal); /* initialize to zeros */
5497 gdbarch = get_frame_arch (return_frame);
5498 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5499 sr_sal.section = find_pc_overlay (sr_sal.pc);
5500 sr_sal.pspace = get_frame_program_space (return_frame);
5502 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5503 get_stack_frame_id (return_frame),
5507 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5508 is used to skip a function after stepping into it (for "next" or if
5509 the called function has no debugging information).
5511 The current function has almost always been reached by single
5512 stepping a call or return instruction. NEXT_FRAME belongs to the
5513 current function, and the breakpoint will be set at the caller's
5516 This is a separate function rather than reusing
5517 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5518 get_prev_frame, which may stop prematurely (see the implementation
5519 of frame_unwind_caller_id for an example). */
5522 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5524 struct symtab_and_line sr_sal;
5525 struct gdbarch *gdbarch;
5527 /* We shouldn't have gotten here if we don't know where the call site
5529 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5531 init_sal (&sr_sal); /* initialize to zeros */
5533 gdbarch = frame_unwind_caller_arch (next_frame);
5534 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5535 frame_unwind_caller_pc (next_frame));
5536 sr_sal.section = find_pc_overlay (sr_sal.pc);
5537 sr_sal.pspace = frame_unwind_program_space (next_frame);
5539 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5540 frame_unwind_caller_id (next_frame));
5543 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5544 new breakpoint at the target of a jmp_buf. The handling of
5545 longjmp-resume uses the same mechanisms used for handling
5546 "step-resume" breakpoints. */
5549 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5551 /* There should never be more than one longjmp-resume breakpoint per
5552 thread, so we should never be setting a new
5553 longjmp_resume_breakpoint when one is already active. */
5554 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
5557 fprintf_unfiltered (gdb_stdlog,
5558 "infrun: inserting longjmp-resume breakpoint at %s\n",
5559 paddress (gdbarch, pc));
5561 inferior_thread ()->control.exception_resume_breakpoint =
5562 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5565 /* Insert an exception resume breakpoint. TP is the thread throwing
5566 the exception. The block B is the block of the unwinder debug hook
5567 function. FRAME is the frame corresponding to the call to this
5568 function. SYM is the symbol of the function argument holding the
5569 target PC of the exception. */
5572 insert_exception_resume_breakpoint (struct thread_info *tp,
5574 struct frame_info *frame,
5577 volatile struct gdb_exception e;
5579 /* We want to ignore errors here. */
5580 TRY_CATCH (e, RETURN_MASK_ERROR)
5582 struct symbol *vsym;
5583 struct value *value;
5585 struct breakpoint *bp;
5587 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5588 value = read_var_value (vsym, frame);
5589 /* If the value was optimized out, revert to the old behavior. */
5590 if (! value_optimized_out (value))
5592 handler = value_as_address (value);
5595 fprintf_unfiltered (gdb_stdlog,
5596 "infrun: exception resume at %lx\n",
5597 (unsigned long) handler);
5599 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5600 handler, bp_exception_resume);
5602 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
5605 bp->thread = tp->num;
5606 inferior_thread ()->control.exception_resume_breakpoint = bp;
5611 /* A helper for check_exception_resume that sets an
5612 exception-breakpoint based on a SystemTap probe. */
5615 insert_exception_resume_from_probe (struct thread_info *tp,
5616 const struct probe *probe,
5617 struct frame_info *frame)
5619 struct value *arg_value;
5621 struct breakpoint *bp;
5623 arg_value = probe_safe_evaluate_at_pc (frame, 1);
5627 handler = value_as_address (arg_value);
5630 fprintf_unfiltered (gdb_stdlog,
5631 "infrun: exception resume at %s\n",
5632 paddress (get_objfile_arch (probe->objfile),
5635 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5636 handler, bp_exception_resume);
5637 bp->thread = tp->num;
5638 inferior_thread ()->control.exception_resume_breakpoint = bp;
5641 /* This is called when an exception has been intercepted. Check to
5642 see whether the exception's destination is of interest, and if so,
5643 set an exception resume breakpoint there. */
5646 check_exception_resume (struct execution_control_state *ecs,
5647 struct frame_info *frame)
5649 volatile struct gdb_exception e;
5650 const struct probe *probe;
5651 struct symbol *func;
5653 /* First see if this exception unwinding breakpoint was set via a
5654 SystemTap probe point. If so, the probe has two arguments: the
5655 CFA and the HANDLER. We ignore the CFA, extract the handler, and
5656 set a breakpoint there. */
5657 probe = find_probe_by_pc (get_frame_pc (frame));
5660 insert_exception_resume_from_probe (ecs->event_thread, probe, frame);
5664 func = get_frame_function (frame);
5668 TRY_CATCH (e, RETURN_MASK_ERROR)
5671 struct block_iterator iter;
5675 /* The exception breakpoint is a thread-specific breakpoint on
5676 the unwinder's debug hook, declared as:
5678 void _Unwind_DebugHook (void *cfa, void *handler);
5680 The CFA argument indicates the frame to which control is
5681 about to be transferred. HANDLER is the destination PC.
5683 We ignore the CFA and set a temporary breakpoint at HANDLER.
5684 This is not extremely efficient but it avoids issues in gdb
5685 with computing the DWARF CFA, and it also works even in weird
5686 cases such as throwing an exception from inside a signal
5689 b = SYMBOL_BLOCK_VALUE (func);
5690 ALL_BLOCK_SYMBOLS (b, iter, sym)
5692 if (!SYMBOL_IS_ARGUMENT (sym))
5699 insert_exception_resume_breakpoint (ecs->event_thread,
5708 stop_stepping (struct execution_control_state *ecs)
5711 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5713 /* Let callers know we don't want to wait for the inferior anymore. */
5714 ecs->wait_some_more = 0;
5717 /* Called when we should continue running the inferior, because the
5718 current event doesn't cause a user visible stop. This does the
5719 resuming part; waiting for the next event is done elsewhere. */
5722 keep_going (struct execution_control_state *ecs)
5724 /* Make sure normal_stop is called if we get a QUIT handled before
5726 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5728 /* Save the pc before execution, to compare with pc after stop. */
5729 ecs->event_thread->prev_pc
5730 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5732 if (ecs->event_thread->control.trap_expected
5733 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5735 /* We haven't yet gotten our trap, and either: intercepted a
5736 non-signal event (e.g., a fork); or took a signal which we
5737 are supposed to pass through to the inferior. Simply
5739 discard_cleanups (old_cleanups);
5740 resume (currently_stepping (ecs->event_thread),
5741 ecs->event_thread->suspend.stop_signal);
5745 /* Either the trap was not expected, but we are continuing
5746 anyway (if we got a signal, the user asked it be passed to
5749 We got our expected trap, but decided we should resume from
5752 We're going to run this baby now!
5754 Note that insert_breakpoints won't try to re-insert
5755 already inserted breakpoints. Therefore, we don't
5756 care if breakpoints were already inserted, or not. */
5758 if (ecs->event_thread->stepping_over_breakpoint)
5760 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5762 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5764 /* Since we can't do a displaced step, we have to remove
5765 the breakpoint while we step it. To keep things
5766 simple, we remove them all. */
5767 remove_breakpoints ();
5772 volatile struct gdb_exception e;
5774 /* Stop stepping if inserting breakpoints fails. */
5775 TRY_CATCH (e, RETURN_MASK_ERROR)
5777 insert_breakpoints ();
5781 exception_print (gdb_stderr, e);
5782 stop_stepping (ecs);
5787 ecs->event_thread->control.trap_expected
5788 = ecs->event_thread->stepping_over_breakpoint;
5790 /* Do not deliver GDB_SIGNAL_TRAP (except when the user
5791 explicitly specifies that such a signal should be delivered
5792 to the target program). Typically, that would occur when a
5793 user is debugging a target monitor on a simulator: the target
5794 monitor sets a breakpoint; the simulator encounters this
5795 breakpoint and halts the simulation handing control to GDB;
5796 GDB, noting that the stop address doesn't map to any known
5797 breakpoint, returns control back to the simulator; the
5798 simulator then delivers the hardware equivalent of a
5799 GDB_SIGNAL_TRAP to the program being debugged. */
5800 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5801 && !signal_program[ecs->event_thread->suspend.stop_signal])
5802 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5804 discard_cleanups (old_cleanups);
5805 resume (currently_stepping (ecs->event_thread),
5806 ecs->event_thread->suspend.stop_signal);
5809 prepare_to_wait (ecs);
5812 /* This function normally comes after a resume, before
5813 handle_inferior_event exits. It takes care of any last bits of
5814 housekeeping, and sets the all-important wait_some_more flag. */
5817 prepare_to_wait (struct execution_control_state *ecs)
5820 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5822 /* This is the old end of the while loop. Let everybody know we
5823 want to wait for the inferior some more and get called again
5825 ecs->wait_some_more = 1;
5828 /* Several print_*_reason functions to print why the inferior has stopped.
5829 We always print something when the inferior exits, or receives a signal.
5830 The rest of the cases are dealt with later on in normal_stop and
5831 print_it_typical. Ideally there should be a call to one of these
5832 print_*_reason functions functions from handle_inferior_event each time
5833 stop_stepping is called. */
5835 /* Print why the inferior has stopped.
5836 We are done with a step/next/si/ni command, print why the inferior has
5837 stopped. For now print nothing. Print a message only if not in the middle
5838 of doing a "step n" operation for n > 1. */
5841 print_end_stepping_range_reason (void)
5843 if ((!inferior_thread ()->step_multi
5844 || !inferior_thread ()->control.stop_step)
5845 && ui_out_is_mi_like_p (current_uiout))
5846 ui_out_field_string (current_uiout, "reason",
5847 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5850 /* The inferior was terminated by a signal, print why it stopped. */
5853 print_signal_exited_reason (enum gdb_signal siggnal)
5855 struct ui_out *uiout = current_uiout;
5857 annotate_signalled ();
5858 if (ui_out_is_mi_like_p (uiout))
5860 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5861 ui_out_text (uiout, "\nProgram terminated with signal ");
5862 annotate_signal_name ();
5863 ui_out_field_string (uiout, "signal-name",
5864 gdb_signal_to_name (siggnal));
5865 annotate_signal_name_end ();
5866 ui_out_text (uiout, ", ");
5867 annotate_signal_string ();
5868 ui_out_field_string (uiout, "signal-meaning",
5869 gdb_signal_to_string (siggnal));
5870 annotate_signal_string_end ();
5871 ui_out_text (uiout, ".\n");
5872 ui_out_text (uiout, "The program no longer exists.\n");
5875 /* The inferior program is finished, print why it stopped. */
5878 print_exited_reason (int exitstatus)
5880 struct inferior *inf = current_inferior ();
5881 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
5882 struct ui_out *uiout = current_uiout;
5884 annotate_exited (exitstatus);
5887 if (ui_out_is_mi_like_p (uiout))
5888 ui_out_field_string (uiout, "reason",
5889 async_reason_lookup (EXEC_ASYNC_EXITED));
5890 ui_out_text (uiout, "[Inferior ");
5891 ui_out_text (uiout, plongest (inf->num));
5892 ui_out_text (uiout, " (");
5893 ui_out_text (uiout, pidstr);
5894 ui_out_text (uiout, ") exited with code ");
5895 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
5896 ui_out_text (uiout, "]\n");
5900 if (ui_out_is_mi_like_p (uiout))
5902 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5903 ui_out_text (uiout, "[Inferior ");
5904 ui_out_text (uiout, plongest (inf->num));
5905 ui_out_text (uiout, " (");
5906 ui_out_text (uiout, pidstr);
5907 ui_out_text (uiout, ") exited normally]\n");
5909 /* Support the --return-child-result option. */
5910 return_child_result_value = exitstatus;
5913 /* Signal received, print why the inferior has stopped. The signal table
5914 tells us to print about it. */
5917 print_signal_received_reason (enum gdb_signal siggnal)
5919 struct ui_out *uiout = current_uiout;
5923 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5925 struct thread_info *t = inferior_thread ();
5927 ui_out_text (uiout, "\n[");
5928 ui_out_field_string (uiout, "thread-name",
5929 target_pid_to_str (t->ptid));
5930 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5931 ui_out_text (uiout, " stopped");
5935 ui_out_text (uiout, "\nProgram received signal ");
5936 annotate_signal_name ();
5937 if (ui_out_is_mi_like_p (uiout))
5939 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5940 ui_out_field_string (uiout, "signal-name",
5941 gdb_signal_to_name (siggnal));
5942 annotate_signal_name_end ();
5943 ui_out_text (uiout, ", ");
5944 annotate_signal_string ();
5945 ui_out_field_string (uiout, "signal-meaning",
5946 gdb_signal_to_string (siggnal));
5947 annotate_signal_string_end ();
5949 ui_out_text (uiout, ".\n");
5952 /* Reverse execution: target ran out of history info, print why the inferior
5956 print_no_history_reason (void)
5958 ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
5961 /* Here to return control to GDB when the inferior stops for real.
5962 Print appropriate messages, remove breakpoints, give terminal our modes.
5964 STOP_PRINT_FRAME nonzero means print the executing frame
5965 (pc, function, args, file, line number and line text).
5966 BREAKPOINTS_FAILED nonzero means stop was due to error
5967 attempting to insert breakpoints. */
5972 struct target_waitstatus last;
5974 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5976 get_last_target_status (&last_ptid, &last);
5978 /* If an exception is thrown from this point on, make sure to
5979 propagate GDB's knowledge of the executing state to the
5980 frontend/user running state. A QUIT is an easy exception to see
5981 here, so do this before any filtered output. */
5983 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5984 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5985 && last.kind != TARGET_WAITKIND_EXITED
5986 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5987 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5989 /* In non-stop mode, we don't want GDB to switch threads behind the
5990 user's back, to avoid races where the user is typing a command to
5991 apply to thread x, but GDB switches to thread y before the user
5992 finishes entering the command. */
5994 /* As with the notification of thread events, we want to delay
5995 notifying the user that we've switched thread context until
5996 the inferior actually stops.
5998 There's no point in saying anything if the inferior has exited.
5999 Note that SIGNALLED here means "exited with a signal", not
6000 "received a signal". */
6002 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
6003 && target_has_execution
6004 && last.kind != TARGET_WAITKIND_SIGNALLED
6005 && last.kind != TARGET_WAITKIND_EXITED
6006 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6008 target_terminal_ours_for_output ();
6009 printf_filtered (_("[Switching to %s]\n"),
6010 target_pid_to_str (inferior_ptid));
6011 annotate_thread_changed ();
6012 previous_inferior_ptid = inferior_ptid;
6015 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
6017 gdb_assert (sync_execution || !target_can_async_p ());
6019 target_terminal_ours_for_output ();
6020 printf_filtered (_("No unwaited-for children left.\n"));
6023 if (!breakpoints_always_inserted_mode () && target_has_execution)
6025 if (remove_breakpoints ())
6027 target_terminal_ours_for_output ();
6028 printf_filtered (_("Cannot remove breakpoints because "
6029 "program is no longer writable.\nFurther "
6030 "execution is probably impossible.\n"));
6034 /* If an auto-display called a function and that got a signal,
6035 delete that auto-display to avoid an infinite recursion. */
6037 if (stopped_by_random_signal)
6038 disable_current_display ();
6040 /* Don't print a message if in the middle of doing a "step n"
6041 operation for n > 1 */
6042 if (target_has_execution
6043 && last.kind != TARGET_WAITKIND_SIGNALLED
6044 && last.kind != TARGET_WAITKIND_EXITED
6045 && inferior_thread ()->step_multi
6046 && inferior_thread ()->control.stop_step)
6049 target_terminal_ours ();
6050 async_enable_stdin ();
6052 /* Set the current source location. This will also happen if we
6053 display the frame below, but the current SAL will be incorrect
6054 during a user hook-stop function. */
6055 if (has_stack_frames () && !stop_stack_dummy)
6056 set_current_sal_from_frame (get_current_frame (), 1);
6058 /* Let the user/frontend see the threads as stopped. */
6059 do_cleanups (old_chain);
6061 /* Look up the hook_stop and run it (CLI internally handles problem
6062 of stop_command's pre-hook not existing). */
6064 catch_errors (hook_stop_stub, stop_command,
6065 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6067 if (!has_stack_frames ())
6070 if (last.kind == TARGET_WAITKIND_SIGNALLED
6071 || last.kind == TARGET_WAITKIND_EXITED)
6074 /* Select innermost stack frame - i.e., current frame is frame 0,
6075 and current location is based on that.
6076 Don't do this on return from a stack dummy routine,
6077 or if the program has exited. */
6079 if (!stop_stack_dummy)
6081 select_frame (get_current_frame ());
6083 /* Print current location without a level number, if
6084 we have changed functions or hit a breakpoint.
6085 Print source line if we have one.
6086 bpstat_print() contains the logic deciding in detail
6087 what to print, based on the event(s) that just occurred. */
6089 /* If --batch-silent is enabled then there's no need to print the current
6090 source location, and to try risks causing an error message about
6091 missing source files. */
6092 if (stop_print_frame && !batch_silent)
6096 int do_frame_printing = 1;
6097 struct thread_info *tp = inferior_thread ();
6099 bpstat_ret = bpstat_print (tp->control.stop_bpstat, last.kind);
6103 /* FIXME: cagney/2002-12-01: Given that a frame ID does
6104 (or should) carry around the function and does (or
6105 should) use that when doing a frame comparison. */
6106 if (tp->control.stop_step
6107 && frame_id_eq (tp->control.step_frame_id,
6108 get_frame_id (get_current_frame ()))
6109 && step_start_function == find_pc_function (stop_pc))
6110 source_flag = SRC_LINE; /* Finished step, just
6111 print source line. */
6113 source_flag = SRC_AND_LOC; /* Print location and
6116 case PRINT_SRC_AND_LOC:
6117 source_flag = SRC_AND_LOC; /* Print location and
6120 case PRINT_SRC_ONLY:
6121 source_flag = SRC_LINE;
6124 source_flag = SRC_LINE; /* something bogus */
6125 do_frame_printing = 0;
6128 internal_error (__FILE__, __LINE__, _("Unknown value."));
6131 /* The behavior of this routine with respect to the source
6133 SRC_LINE: Print only source line
6134 LOCATION: Print only location
6135 SRC_AND_LOC: Print location and source line. */
6136 if (do_frame_printing)
6137 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
6139 /* Display the auto-display expressions. */
6144 /* Save the function value return registers, if we care.
6145 We might be about to restore their previous contents. */
6146 if (inferior_thread ()->control.proceed_to_finish
6147 && execution_direction != EXEC_REVERSE)
6149 /* This should not be necessary. */
6151 regcache_xfree (stop_registers);
6153 /* NB: The copy goes through to the target picking up the value of
6154 all the registers. */
6155 stop_registers = regcache_dup (get_current_regcache ());
6158 if (stop_stack_dummy == STOP_STACK_DUMMY)
6160 /* Pop the empty frame that contains the stack dummy.
6161 This also restores inferior state prior to the call
6162 (struct infcall_suspend_state). */
6163 struct frame_info *frame = get_current_frame ();
6165 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6167 /* frame_pop() calls reinit_frame_cache as the last thing it
6168 does which means there's currently no selected frame. We
6169 don't need to re-establish a selected frame if the dummy call
6170 returns normally, that will be done by
6171 restore_infcall_control_state. However, we do have to handle
6172 the case where the dummy call is returning after being
6173 stopped (e.g. the dummy call previously hit a breakpoint).
6174 We can't know which case we have so just always re-establish
6175 a selected frame here. */
6176 select_frame (get_current_frame ());
6180 annotate_stopped ();
6182 /* Suppress the stop observer if we're in the middle of:
6184 - a step n (n > 1), as there still more steps to be done.
6186 - a "finish" command, as the observer will be called in
6187 finish_command_continuation, so it can include the inferior
6188 function's return value.
6190 - calling an inferior function, as we pretend we inferior didn't
6191 run at all. The return value of the call is handled by the
6192 expression evaluator, through call_function_by_hand. */
6194 if (!target_has_execution
6195 || last.kind == TARGET_WAITKIND_SIGNALLED
6196 || last.kind == TARGET_WAITKIND_EXITED
6197 || last.kind == TARGET_WAITKIND_NO_RESUMED
6198 || (!(inferior_thread ()->step_multi
6199 && inferior_thread ()->control.stop_step)
6200 && !(inferior_thread ()->control.stop_bpstat
6201 && inferior_thread ()->control.proceed_to_finish)
6202 && !inferior_thread ()->control.in_infcall))
6204 if (!ptid_equal (inferior_ptid, null_ptid))
6205 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6208 observer_notify_normal_stop (NULL, stop_print_frame);
6211 if (target_has_execution)
6213 if (last.kind != TARGET_WAITKIND_SIGNALLED
6214 && last.kind != TARGET_WAITKIND_EXITED)
6215 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6216 Delete any breakpoint that is to be deleted at the next stop. */
6217 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6220 /* Try to get rid of automatically added inferiors that are no
6221 longer needed. Keeping those around slows down things linearly.
6222 Note that this never removes the current inferior. */
6227 hook_stop_stub (void *cmd)
6229 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6234 signal_stop_state (int signo)
6236 return signal_stop[signo];
6240 signal_print_state (int signo)
6242 return signal_print[signo];
6246 signal_pass_state (int signo)
6248 return signal_program[signo];
6252 signal_cache_update (int signo)
6256 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6257 signal_cache_update (signo);
6262 signal_pass[signo] = (signal_stop[signo] == 0
6263 && signal_print[signo] == 0
6264 && signal_program[signo] == 1
6265 && signal_catch[signo] == 0);
6269 signal_stop_update (int signo, int state)
6271 int ret = signal_stop[signo];
6273 signal_stop[signo] = state;
6274 signal_cache_update (signo);
6279 signal_print_update (int signo, int state)
6281 int ret = signal_print[signo];
6283 signal_print[signo] = state;
6284 signal_cache_update (signo);
6289 signal_pass_update (int signo, int state)
6291 int ret = signal_program[signo];
6293 signal_program[signo] = state;
6294 signal_cache_update (signo);
6298 /* Update the global 'signal_catch' from INFO and notify the
6302 signal_catch_update (const unsigned int *info)
6306 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6307 signal_catch[i] = info[i] > 0;
6308 signal_cache_update (-1);
6309 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6313 sig_print_header (void)
6315 printf_filtered (_("Signal Stop\tPrint\tPass "
6316 "to program\tDescription\n"));
6320 sig_print_info (enum gdb_signal oursig)
6322 const char *name = gdb_signal_to_name (oursig);
6323 int name_padding = 13 - strlen (name);
6325 if (name_padding <= 0)
6328 printf_filtered ("%s", name);
6329 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6330 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6331 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6332 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6333 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6336 /* Specify how various signals in the inferior should be handled. */
6339 handle_command (char *args, int from_tty)
6342 int digits, wordlen;
6343 int sigfirst, signum, siglast;
6344 enum gdb_signal oursig;
6347 unsigned char *sigs;
6348 struct cleanup *old_chain;
6352 error_no_arg (_("signal to handle"));
6355 /* Allocate and zero an array of flags for which signals to handle. */
6357 nsigs = (int) GDB_SIGNAL_LAST;
6358 sigs = (unsigned char *) alloca (nsigs);
6359 memset (sigs, 0, nsigs);
6361 /* Break the command line up into args. */
6363 argv = gdb_buildargv (args);
6364 old_chain = make_cleanup_freeargv (argv);
6366 /* Walk through the args, looking for signal oursigs, signal names, and
6367 actions. Signal numbers and signal names may be interspersed with
6368 actions, with the actions being performed for all signals cumulatively
6369 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6371 while (*argv != NULL)
6373 wordlen = strlen (*argv);
6374 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6378 sigfirst = siglast = -1;
6380 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6382 /* Apply action to all signals except those used by the
6383 debugger. Silently skip those. */
6386 siglast = nsigs - 1;
6388 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6390 SET_SIGS (nsigs, sigs, signal_stop);
6391 SET_SIGS (nsigs, sigs, signal_print);
6393 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6395 UNSET_SIGS (nsigs, sigs, signal_program);
6397 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6399 SET_SIGS (nsigs, sigs, signal_print);
6401 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6403 SET_SIGS (nsigs, sigs, signal_program);
6405 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6407 UNSET_SIGS (nsigs, sigs, signal_stop);
6409 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6411 SET_SIGS (nsigs, sigs, signal_program);
6413 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6415 UNSET_SIGS (nsigs, sigs, signal_print);
6416 UNSET_SIGS (nsigs, sigs, signal_stop);
6418 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6420 UNSET_SIGS (nsigs, sigs, signal_program);
6422 else if (digits > 0)
6424 /* It is numeric. The numeric signal refers to our own
6425 internal signal numbering from target.h, not to host/target
6426 signal number. This is a feature; users really should be
6427 using symbolic names anyway, and the common ones like
6428 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6430 sigfirst = siglast = (int)
6431 gdb_signal_from_command (atoi (*argv));
6432 if ((*argv)[digits] == '-')
6435 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6437 if (sigfirst > siglast)
6439 /* Bet he didn't figure we'd think of this case... */
6447 oursig = gdb_signal_from_name (*argv);
6448 if (oursig != GDB_SIGNAL_UNKNOWN)
6450 sigfirst = siglast = (int) oursig;
6454 /* Not a number and not a recognized flag word => complain. */
6455 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6459 /* If any signal numbers or symbol names were found, set flags for
6460 which signals to apply actions to. */
6462 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6464 switch ((enum gdb_signal) signum)
6466 case GDB_SIGNAL_TRAP:
6467 case GDB_SIGNAL_INT:
6468 if (!allsigs && !sigs[signum])
6470 if (query (_("%s is used by the debugger.\n\
6471 Are you sure you want to change it? "),
6472 gdb_signal_to_name ((enum gdb_signal) signum)))
6478 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6479 gdb_flush (gdb_stdout);
6484 case GDB_SIGNAL_DEFAULT:
6485 case GDB_SIGNAL_UNKNOWN:
6486 /* Make sure that "all" doesn't print these. */
6497 for (signum = 0; signum < nsigs; signum++)
6500 signal_cache_update (-1);
6501 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6502 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
6506 /* Show the results. */
6507 sig_print_header ();
6508 for (; signum < nsigs; signum++)
6510 sig_print_info (signum);
6516 do_cleanups (old_chain);
6519 /* Complete the "handle" command. */
6521 static VEC (char_ptr) *
6522 handle_completer (struct cmd_list_element *ignore,
6523 const char *text, const char *word)
6525 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
6526 static const char * const keywords[] =
6540 vec_signals = signal_completer (ignore, text, word);
6541 vec_keywords = complete_on_enum (keywords, word, word);
6543 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
6544 VEC_free (char_ptr, vec_signals);
6545 VEC_free (char_ptr, vec_keywords);
6550 xdb_handle_command (char *args, int from_tty)
6553 struct cleanup *old_chain;
6556 error_no_arg (_("xdb command"));
6558 /* Break the command line up into args. */
6560 argv = gdb_buildargv (args);
6561 old_chain = make_cleanup_freeargv (argv);
6562 if (argv[1] != (char *) NULL)
6567 bufLen = strlen (argv[0]) + 20;
6568 argBuf = (char *) xmalloc (bufLen);
6572 enum gdb_signal oursig;
6574 oursig = gdb_signal_from_name (argv[0]);
6575 memset (argBuf, 0, bufLen);
6576 if (strcmp (argv[1], "Q") == 0)
6577 sprintf (argBuf, "%s %s", argv[0], "noprint");
6580 if (strcmp (argv[1], "s") == 0)
6582 if (!signal_stop[oursig])
6583 sprintf (argBuf, "%s %s", argv[0], "stop");
6585 sprintf (argBuf, "%s %s", argv[0], "nostop");
6587 else if (strcmp (argv[1], "i") == 0)
6589 if (!signal_program[oursig])
6590 sprintf (argBuf, "%s %s", argv[0], "pass");
6592 sprintf (argBuf, "%s %s", argv[0], "nopass");
6594 else if (strcmp (argv[1], "r") == 0)
6596 if (!signal_print[oursig])
6597 sprintf (argBuf, "%s %s", argv[0], "print");
6599 sprintf (argBuf, "%s %s", argv[0], "noprint");
6605 handle_command (argBuf, from_tty);
6607 printf_filtered (_("Invalid signal handling flag.\n"));
6612 do_cleanups (old_chain);
6616 gdb_signal_from_command (int num)
6618 if (num >= 1 && num <= 15)
6619 return (enum gdb_signal) num;
6620 error (_("Only signals 1-15 are valid as numeric signals.\n\
6621 Use \"info signals\" for a list of symbolic signals."));
6624 /* Print current contents of the tables set by the handle command.
6625 It is possible we should just be printing signals actually used
6626 by the current target (but for things to work right when switching
6627 targets, all signals should be in the signal tables). */
6630 signals_info (char *signum_exp, int from_tty)
6632 enum gdb_signal oursig;
6634 sig_print_header ();
6638 /* First see if this is a symbol name. */
6639 oursig = gdb_signal_from_name (signum_exp);
6640 if (oursig == GDB_SIGNAL_UNKNOWN)
6642 /* No, try numeric. */
6644 gdb_signal_from_command (parse_and_eval_long (signum_exp));
6646 sig_print_info (oursig);
6650 printf_filtered ("\n");
6651 /* These ugly casts brought to you by the native VAX compiler. */
6652 for (oursig = GDB_SIGNAL_FIRST;
6653 (int) oursig < (int) GDB_SIGNAL_LAST;
6654 oursig = (enum gdb_signal) ((int) oursig + 1))
6658 if (oursig != GDB_SIGNAL_UNKNOWN
6659 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
6660 sig_print_info (oursig);
6663 printf_filtered (_("\nUse the \"handle\" command "
6664 "to change these tables.\n"));
6667 /* Check if it makes sense to read $_siginfo from the current thread
6668 at this point. If not, throw an error. */
6671 validate_siginfo_access (void)
6673 /* No current inferior, no siginfo. */
6674 if (ptid_equal (inferior_ptid, null_ptid))
6675 error (_("No thread selected."));
6677 /* Don't try to read from a dead thread. */
6678 if (is_exited (inferior_ptid))
6679 error (_("The current thread has terminated"));
6681 /* ... or from a spinning thread. */
6682 if (is_running (inferior_ptid))
6683 error (_("Selected thread is running."));
6686 /* The $_siginfo convenience variable is a bit special. We don't know
6687 for sure the type of the value until we actually have a chance to
6688 fetch the data. The type can change depending on gdbarch, so it is
6689 also dependent on which thread you have selected.
6691 1. making $_siginfo be an internalvar that creates a new value on
6694 2. making the value of $_siginfo be an lval_computed value. */
6696 /* This function implements the lval_computed support for reading a
6700 siginfo_value_read (struct value *v)
6702 LONGEST transferred;
6704 validate_siginfo_access ();
6707 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
6709 value_contents_all_raw (v),
6711 TYPE_LENGTH (value_type (v)));
6713 if (transferred != TYPE_LENGTH (value_type (v)))
6714 error (_("Unable to read siginfo"));
6717 /* This function implements the lval_computed support for writing a
6721 siginfo_value_write (struct value *v, struct value *fromval)
6723 LONGEST transferred;
6725 validate_siginfo_access ();
6727 transferred = target_write (¤t_target,
6728 TARGET_OBJECT_SIGNAL_INFO,
6730 value_contents_all_raw (fromval),
6732 TYPE_LENGTH (value_type (fromval)));
6734 if (transferred != TYPE_LENGTH (value_type (fromval)))
6735 error (_("Unable to write siginfo"));
6738 static const struct lval_funcs siginfo_value_funcs =
6744 /* Return a new value with the correct type for the siginfo object of
6745 the current thread using architecture GDBARCH. Return a void value
6746 if there's no object available. */
6748 static struct value *
6749 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
6752 if (target_has_stack
6753 && !ptid_equal (inferior_ptid, null_ptid)
6754 && gdbarch_get_siginfo_type_p (gdbarch))
6756 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6758 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
6761 return allocate_value (builtin_type (gdbarch)->builtin_void);
6765 /* infcall_suspend_state contains state about the program itself like its
6766 registers and any signal it received when it last stopped.
6767 This state must be restored regardless of how the inferior function call
6768 ends (either successfully, or after it hits a breakpoint or signal)
6769 if the program is to properly continue where it left off. */
6771 struct infcall_suspend_state
6773 struct thread_suspend_state thread_suspend;
6774 #if 0 /* Currently unused and empty structures are not valid C. */
6775 struct inferior_suspend_state inferior_suspend;
6780 struct regcache *registers;
6782 /* Format of SIGINFO_DATA or NULL if it is not present. */
6783 struct gdbarch *siginfo_gdbarch;
6785 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6786 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6787 content would be invalid. */
6788 gdb_byte *siginfo_data;
6791 struct infcall_suspend_state *
6792 save_infcall_suspend_state (void)
6794 struct infcall_suspend_state *inf_state;
6795 struct thread_info *tp = inferior_thread ();
6797 struct inferior *inf = current_inferior ();
6799 struct regcache *regcache = get_current_regcache ();
6800 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6801 gdb_byte *siginfo_data = NULL;
6803 if (gdbarch_get_siginfo_type_p (gdbarch))
6805 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6806 size_t len = TYPE_LENGTH (type);
6807 struct cleanup *back_to;
6809 siginfo_data = xmalloc (len);
6810 back_to = make_cleanup (xfree, siginfo_data);
6812 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6813 siginfo_data, 0, len) == len)
6814 discard_cleanups (back_to);
6817 /* Errors ignored. */
6818 do_cleanups (back_to);
6819 siginfo_data = NULL;
6823 inf_state = XZALLOC (struct infcall_suspend_state);
6827 inf_state->siginfo_gdbarch = gdbarch;
6828 inf_state->siginfo_data = siginfo_data;
6831 inf_state->thread_suspend = tp->suspend;
6832 #if 0 /* Currently unused and empty structures are not valid C. */
6833 inf_state->inferior_suspend = inf->suspend;
6836 /* run_inferior_call will not use the signal due to its `proceed' call with
6837 GDB_SIGNAL_0 anyway. */
6838 tp->suspend.stop_signal = GDB_SIGNAL_0;
6840 inf_state->stop_pc = stop_pc;
6842 inf_state->registers = regcache_dup (regcache);
6847 /* Restore inferior session state to INF_STATE. */
6850 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6852 struct thread_info *tp = inferior_thread ();
6854 struct inferior *inf = current_inferior ();
6856 struct regcache *regcache = get_current_regcache ();
6857 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6859 tp->suspend = inf_state->thread_suspend;
6860 #if 0 /* Currently unused and empty structures are not valid C. */
6861 inf->suspend = inf_state->inferior_suspend;
6864 stop_pc = inf_state->stop_pc;
6866 if (inf_state->siginfo_gdbarch == gdbarch)
6868 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6870 /* Errors ignored. */
6871 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6872 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
6875 /* The inferior can be gone if the user types "print exit(0)"
6876 (and perhaps other times). */
6877 if (target_has_execution)
6878 /* NB: The register write goes through to the target. */
6879 regcache_cpy (regcache, inf_state->registers);
6881 discard_infcall_suspend_state (inf_state);
6885 do_restore_infcall_suspend_state_cleanup (void *state)
6887 restore_infcall_suspend_state (state);
6891 make_cleanup_restore_infcall_suspend_state
6892 (struct infcall_suspend_state *inf_state)
6894 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
6898 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6900 regcache_xfree (inf_state->registers);
6901 xfree (inf_state->siginfo_data);
6906 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
6908 return inf_state->registers;
6911 /* infcall_control_state contains state regarding gdb's control of the
6912 inferior itself like stepping control. It also contains session state like
6913 the user's currently selected frame. */
6915 struct infcall_control_state
6917 struct thread_control_state thread_control;
6918 struct inferior_control_state inferior_control;
6921 enum stop_stack_kind stop_stack_dummy;
6922 int stopped_by_random_signal;
6923 int stop_after_trap;
6925 /* ID if the selected frame when the inferior function call was made. */
6926 struct frame_id selected_frame_id;
6929 /* Save all of the information associated with the inferior<==>gdb
6932 struct infcall_control_state *
6933 save_infcall_control_state (void)
6935 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
6936 struct thread_info *tp = inferior_thread ();
6937 struct inferior *inf = current_inferior ();
6939 inf_status->thread_control = tp->control;
6940 inf_status->inferior_control = inf->control;
6942 tp->control.step_resume_breakpoint = NULL;
6943 tp->control.exception_resume_breakpoint = NULL;
6945 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6946 chain. If caller's caller is walking the chain, they'll be happier if we
6947 hand them back the original chain when restore_infcall_control_state is
6949 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
6952 inf_status->stop_stack_dummy = stop_stack_dummy;
6953 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6954 inf_status->stop_after_trap = stop_after_trap;
6956 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6962 restore_selected_frame (void *args)
6964 struct frame_id *fid = (struct frame_id *) args;
6965 struct frame_info *frame;
6967 frame = frame_find_by_id (*fid);
6969 /* If inf_status->selected_frame_id is NULL, there was no previously
6973 warning (_("Unable to restore previously selected frame."));
6977 select_frame (frame);
6982 /* Restore inferior session state to INF_STATUS. */
6985 restore_infcall_control_state (struct infcall_control_state *inf_status)
6987 struct thread_info *tp = inferior_thread ();
6988 struct inferior *inf = current_inferior ();
6990 if (tp->control.step_resume_breakpoint)
6991 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
6993 if (tp->control.exception_resume_breakpoint)
6994 tp->control.exception_resume_breakpoint->disposition
6995 = disp_del_at_next_stop;
6997 /* Handle the bpstat_copy of the chain. */
6998 bpstat_clear (&tp->control.stop_bpstat);
7000 tp->control = inf_status->thread_control;
7001 inf->control = inf_status->inferior_control;
7004 stop_stack_dummy = inf_status->stop_stack_dummy;
7005 stopped_by_random_signal = inf_status->stopped_by_random_signal;
7006 stop_after_trap = inf_status->stop_after_trap;
7008 if (target_has_stack)
7010 /* The point of catch_errors is that if the stack is clobbered,
7011 walking the stack might encounter a garbage pointer and
7012 error() trying to dereference it. */
7014 (restore_selected_frame, &inf_status->selected_frame_id,
7015 "Unable to restore previously selected frame:\n",
7016 RETURN_MASK_ERROR) == 0)
7017 /* Error in restoring the selected frame. Select the innermost
7019 select_frame (get_current_frame ());
7026 do_restore_infcall_control_state_cleanup (void *sts)
7028 restore_infcall_control_state (sts);
7032 make_cleanup_restore_infcall_control_state
7033 (struct infcall_control_state *inf_status)
7035 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
7039 discard_infcall_control_state (struct infcall_control_state *inf_status)
7041 if (inf_status->thread_control.step_resume_breakpoint)
7042 inf_status->thread_control.step_resume_breakpoint->disposition
7043 = disp_del_at_next_stop;
7045 if (inf_status->thread_control.exception_resume_breakpoint)
7046 inf_status->thread_control.exception_resume_breakpoint->disposition
7047 = disp_del_at_next_stop;
7049 /* See save_infcall_control_state for info on stop_bpstat. */
7050 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7056 ptid_match (ptid_t ptid, ptid_t filter)
7058 if (ptid_equal (filter, minus_one_ptid))
7060 if (ptid_is_pid (filter)
7061 && ptid_get_pid (ptid) == ptid_get_pid (filter))
7063 else if (ptid_equal (ptid, filter))
7069 /* restore_inferior_ptid() will be used by the cleanup machinery
7070 to restore the inferior_ptid value saved in a call to
7071 save_inferior_ptid(). */
7074 restore_inferior_ptid (void *arg)
7076 ptid_t *saved_ptid_ptr = arg;
7078 inferior_ptid = *saved_ptid_ptr;
7082 /* Save the value of inferior_ptid so that it may be restored by a
7083 later call to do_cleanups(). Returns the struct cleanup pointer
7084 needed for later doing the cleanup. */
7087 save_inferior_ptid (void)
7089 ptid_t *saved_ptid_ptr;
7091 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7092 *saved_ptid_ptr = inferior_ptid;
7093 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7096 /* See inferior.h. */
7099 clear_exit_convenience_vars (void)
7101 clear_internalvar (lookup_internalvar ("_exitsignal"));
7102 clear_internalvar (lookup_internalvar ("_exitcode"));
7106 /* User interface for reverse debugging:
7107 Set exec-direction / show exec-direction commands
7108 (returns error unless target implements to_set_exec_direction method). */
7110 int execution_direction = EXEC_FORWARD;
7111 static const char exec_forward[] = "forward";
7112 static const char exec_reverse[] = "reverse";
7113 static const char *exec_direction = exec_forward;
7114 static const char *const exec_direction_names[] = {
7121 set_exec_direction_func (char *args, int from_tty,
7122 struct cmd_list_element *cmd)
7124 if (target_can_execute_reverse)
7126 if (!strcmp (exec_direction, exec_forward))
7127 execution_direction = EXEC_FORWARD;
7128 else if (!strcmp (exec_direction, exec_reverse))
7129 execution_direction = EXEC_REVERSE;
7133 exec_direction = exec_forward;
7134 error (_("Target does not support this operation."));
7139 show_exec_direction_func (struct ui_file *out, int from_tty,
7140 struct cmd_list_element *cmd, const char *value)
7142 switch (execution_direction) {
7144 fprintf_filtered (out, _("Forward.\n"));
7147 fprintf_filtered (out, _("Reverse.\n"));
7150 internal_error (__FILE__, __LINE__,
7151 _("bogus execution_direction value: %d"),
7152 (int) execution_direction);
7157 show_schedule_multiple (struct ui_file *file, int from_tty,
7158 struct cmd_list_element *c, const char *value)
7160 fprintf_filtered (file, _("Resuming the execution of threads "
7161 "of all processes is %s.\n"), value);
7164 /* Implementation of `siginfo' variable. */
7166 static const struct internalvar_funcs siginfo_funcs =
7174 _initialize_infrun (void)
7178 struct cmd_list_element *c;
7180 add_info ("signals", signals_info, _("\
7181 What debugger does when program gets various signals.\n\
7182 Specify a signal as argument to print info on that signal only."));
7183 add_info_alias ("handle", "signals", 0);
7185 c = add_com ("handle", class_run, handle_command, _("\
7186 Specify how to handle signals.\n\
7187 Usage: handle SIGNAL [ACTIONS]\n\
7188 Args are signals and actions to apply to those signals.\n\
7189 If no actions are specified, the current settings for the specified signals\n\
7190 will be displayed instead.\n\
7192 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7193 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7194 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7195 The special arg \"all\" is recognized to mean all signals except those\n\
7196 used by the debugger, typically SIGTRAP and SIGINT.\n\
7198 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7199 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7200 Stop means reenter debugger if this signal happens (implies print).\n\
7201 Print means print a message if this signal happens.\n\
7202 Pass means let program see this signal; otherwise program doesn't know.\n\
7203 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7204 Pass and Stop may be combined.\n\
7206 Multiple signals may be specified. Signal numbers and signal names\n\
7207 may be interspersed with actions, with the actions being performed for\n\
7208 all signals cumulatively specified."));
7209 set_cmd_completer (c, handle_completer);
7213 add_com ("lz", class_info, signals_info, _("\
7214 What debugger does when program gets various signals.\n\
7215 Specify a signal as argument to print info on that signal only."));
7216 add_com ("z", class_run, xdb_handle_command, _("\
7217 Specify how to handle a signal.\n\
7218 Args are signals and actions to apply to those signals.\n\
7219 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7220 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7221 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7222 The special arg \"all\" is recognized to mean all signals except those\n\
7223 used by the debugger, typically SIGTRAP and SIGINT.\n\
7224 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7225 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7226 nopass), \"Q\" (noprint)\n\
7227 Stop means reenter debugger if this signal happens (implies print).\n\
7228 Print means print a message if this signal happens.\n\
7229 Pass means let program see this signal; otherwise program doesn't know.\n\
7230 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7231 Pass and Stop may be combined."));
7235 stop_command = add_cmd ("stop", class_obscure,
7236 not_just_help_class_command, _("\
7237 There is no `stop' command, but you can set a hook on `stop'.\n\
7238 This allows you to set a list of commands to be run each time execution\n\
7239 of the program stops."), &cmdlist);
7241 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7242 Set inferior debugging."), _("\
7243 Show inferior debugging."), _("\
7244 When non-zero, inferior specific debugging is enabled."),
7247 &setdebuglist, &showdebuglist);
7249 add_setshow_boolean_cmd ("displaced", class_maintenance,
7250 &debug_displaced, _("\
7251 Set displaced stepping debugging."), _("\
7252 Show displaced stepping debugging."), _("\
7253 When non-zero, displaced stepping specific debugging is enabled."),
7255 show_debug_displaced,
7256 &setdebuglist, &showdebuglist);
7258 add_setshow_boolean_cmd ("non-stop", no_class,
7260 Set whether gdb controls the inferior in non-stop mode."), _("\
7261 Show whether gdb controls the inferior in non-stop mode."), _("\
7262 When debugging a multi-threaded program and this setting is\n\
7263 off (the default, also called all-stop mode), when one thread stops\n\
7264 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7265 all other threads in the program while you interact with the thread of\n\
7266 interest. When you continue or step a thread, you can allow the other\n\
7267 threads to run, or have them remain stopped, but while you inspect any\n\
7268 thread's state, all threads stop.\n\
7270 In non-stop mode, when one thread stops, other threads can continue\n\
7271 to run freely. You'll be able to step each thread independently,\n\
7272 leave it stopped or free to run as needed."),
7278 numsigs = (int) GDB_SIGNAL_LAST;
7279 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7280 signal_print = (unsigned char *)
7281 xmalloc (sizeof (signal_print[0]) * numsigs);
7282 signal_program = (unsigned char *)
7283 xmalloc (sizeof (signal_program[0]) * numsigs);
7284 signal_catch = (unsigned char *)
7285 xmalloc (sizeof (signal_catch[0]) * numsigs);
7286 signal_pass = (unsigned char *)
7287 xmalloc (sizeof (signal_program[0]) * numsigs);
7288 for (i = 0; i < numsigs; i++)
7291 signal_print[i] = 1;
7292 signal_program[i] = 1;
7293 signal_catch[i] = 0;
7296 /* Signals caused by debugger's own actions
7297 should not be given to the program afterwards. */
7298 signal_program[GDB_SIGNAL_TRAP] = 0;
7299 signal_program[GDB_SIGNAL_INT] = 0;
7301 /* Signals that are not errors should not normally enter the debugger. */
7302 signal_stop[GDB_SIGNAL_ALRM] = 0;
7303 signal_print[GDB_SIGNAL_ALRM] = 0;
7304 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7305 signal_print[GDB_SIGNAL_VTALRM] = 0;
7306 signal_stop[GDB_SIGNAL_PROF] = 0;
7307 signal_print[GDB_SIGNAL_PROF] = 0;
7308 signal_stop[GDB_SIGNAL_CHLD] = 0;
7309 signal_print[GDB_SIGNAL_CHLD] = 0;
7310 signal_stop[GDB_SIGNAL_IO] = 0;
7311 signal_print[GDB_SIGNAL_IO] = 0;
7312 signal_stop[GDB_SIGNAL_POLL] = 0;
7313 signal_print[GDB_SIGNAL_POLL] = 0;
7314 signal_stop[GDB_SIGNAL_URG] = 0;
7315 signal_print[GDB_SIGNAL_URG] = 0;
7316 signal_stop[GDB_SIGNAL_WINCH] = 0;
7317 signal_print[GDB_SIGNAL_WINCH] = 0;
7318 signal_stop[GDB_SIGNAL_PRIO] = 0;
7319 signal_print[GDB_SIGNAL_PRIO] = 0;
7321 /* These signals are used internally by user-level thread
7322 implementations. (See signal(5) on Solaris.) Like the above
7323 signals, a healthy program receives and handles them as part of
7324 its normal operation. */
7325 signal_stop[GDB_SIGNAL_LWP] = 0;
7326 signal_print[GDB_SIGNAL_LWP] = 0;
7327 signal_stop[GDB_SIGNAL_WAITING] = 0;
7328 signal_print[GDB_SIGNAL_WAITING] = 0;
7329 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7330 signal_print[GDB_SIGNAL_CANCEL] = 0;
7332 /* Update cached state. */
7333 signal_cache_update (-1);
7335 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7336 &stop_on_solib_events, _("\
7337 Set stopping for shared library events."), _("\
7338 Show stopping for shared library events."), _("\
7339 If nonzero, gdb will give control to the user when the dynamic linker\n\
7340 notifies gdb of shared library events. The most common event of interest\n\
7341 to the user would be loading/unloading of a new library."),
7342 set_stop_on_solib_events,
7343 show_stop_on_solib_events,
7344 &setlist, &showlist);
7346 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7347 follow_fork_mode_kind_names,
7348 &follow_fork_mode_string, _("\
7349 Set debugger response to a program call of fork or vfork."), _("\
7350 Show debugger response to a program call of fork or vfork."), _("\
7351 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7352 parent - the original process is debugged after a fork\n\
7353 child - the new process is debugged after a fork\n\
7354 The unfollowed process will continue to run.\n\
7355 By default, the debugger will follow the parent process."),
7357 show_follow_fork_mode_string,
7358 &setlist, &showlist);
7360 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7361 follow_exec_mode_names,
7362 &follow_exec_mode_string, _("\
7363 Set debugger response to a program call of exec."), _("\
7364 Show debugger response to a program call of exec."), _("\
7365 An exec call replaces the program image of a process.\n\
7367 follow-exec-mode can be:\n\
7369 new - the debugger creates a new inferior and rebinds the process\n\
7370 to this new inferior. The program the process was running before\n\
7371 the exec call can be restarted afterwards by restarting the original\n\
7374 same - the debugger keeps the process bound to the same inferior.\n\
7375 The new executable image replaces the previous executable loaded in\n\
7376 the inferior. Restarting the inferior after the exec call restarts\n\
7377 the executable the process was running after the exec call.\n\
7379 By default, the debugger will use the same inferior."),
7381 show_follow_exec_mode_string,
7382 &setlist, &showlist);
7384 add_setshow_enum_cmd ("scheduler-locking", class_run,
7385 scheduler_enums, &scheduler_mode, _("\
7386 Set mode for locking scheduler during execution."), _("\
7387 Show mode for locking scheduler during execution."), _("\
7388 off == no locking (threads may preempt at any time)\n\
7389 on == full locking (no thread except the current thread may run)\n\
7390 step == scheduler locked during every single-step operation.\n\
7391 In this mode, no other thread may run during a step command.\n\
7392 Other threads may run while stepping over a function call ('next')."),
7393 set_schedlock_func, /* traps on target vector */
7394 show_scheduler_mode,
7395 &setlist, &showlist);
7397 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7398 Set mode for resuming threads of all processes."), _("\
7399 Show mode for resuming threads of all processes."), _("\
7400 When on, execution commands (such as 'continue' or 'next') resume all\n\
7401 threads of all processes. When off (which is the default), execution\n\
7402 commands only resume the threads of the current process. The set of\n\
7403 threads that are resumed is further refined by the scheduler-locking\n\
7404 mode (see help set scheduler-locking)."),
7406 show_schedule_multiple,
7407 &setlist, &showlist);
7409 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7410 Set mode of the step operation."), _("\
7411 Show mode of the step operation."), _("\
7412 When set, doing a step over a function without debug line information\n\
7413 will stop at the first instruction of that function. Otherwise, the\n\
7414 function is skipped and the step command stops at a different source line."),
7416 show_step_stop_if_no_debug,
7417 &setlist, &showlist);
7419 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7420 &can_use_displaced_stepping, _("\
7421 Set debugger's willingness to use displaced stepping."), _("\
7422 Show debugger's willingness to use displaced stepping."), _("\
7423 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7424 supported by the target architecture. If off, gdb will not use displaced\n\
7425 stepping to step over breakpoints, even if such is supported by the target\n\
7426 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7427 if the target architecture supports it and non-stop mode is active, but will not\n\
7428 use it in all-stop mode (see help set non-stop)."),
7430 show_can_use_displaced_stepping,
7431 &setlist, &showlist);
7433 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7434 &exec_direction, _("Set direction of execution.\n\
7435 Options are 'forward' or 'reverse'."),
7436 _("Show direction of execution (forward/reverse)."),
7437 _("Tells gdb whether to execute forward or backward."),
7438 set_exec_direction_func, show_exec_direction_func,
7439 &setlist, &showlist);
7441 /* Set/show detach-on-fork: user-settable mode. */
7443 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7444 Set whether gdb will detach the child of a fork."), _("\
7445 Show whether gdb will detach the child of a fork."), _("\
7446 Tells gdb whether to detach the child of a fork."),
7447 NULL, NULL, &setlist, &showlist);
7449 /* Set/show disable address space randomization mode. */
7451 add_setshow_boolean_cmd ("disable-randomization", class_support,
7452 &disable_randomization, _("\
7453 Set disabling of debuggee's virtual address space randomization."), _("\
7454 Show disabling of debuggee's virtual address space randomization."), _("\
7455 When this mode is on (which is the default), randomization of the virtual\n\
7456 address space is disabled. Standalone programs run with the randomization\n\
7457 enabled by default on some platforms."),
7458 &set_disable_randomization,
7459 &show_disable_randomization,
7460 &setlist, &showlist);
7462 /* ptid initializations */
7463 inferior_ptid = null_ptid;
7464 target_last_wait_ptid = minus_one_ptid;
7466 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7467 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7468 observer_attach_thread_exit (infrun_thread_thread_exit);
7469 observer_attach_inferior_exit (infrun_inferior_exit);
7471 /* Explicitly create without lookup, since that tries to create a
7472 value with a void typed value, and when we get here, gdbarch
7473 isn't initialized yet. At this point, we're quite sure there
7474 isn't another convenience variable of the same name. */
7475 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7477 add_setshow_boolean_cmd ("observer", no_class,
7478 &observer_mode_1, _("\
7479 Set whether gdb controls the inferior in observer mode."), _("\
7480 Show whether gdb controls the inferior in observer mode."), _("\
7481 In observer mode, GDB can get data from the inferior, but not\n\
7482 affect its execution. Registers and memory may not be changed,\n\
7483 breakpoints may not be set, and the program cannot be interrupted\n\