1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2015 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/>. */
27 #include "breakpoint.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 #include "event-loop.h"
65 #include "thread-fsm.h"
67 /* Prototypes for local functions */
69 static void signals_info (char *, int);
71 static void handle_command (char *, int);
73 static void sig_print_info (enum gdb_signal);
75 static void sig_print_header (void);
77 static void resume_cleanups (void *);
79 static int hook_stop_stub (void *);
81 static int restore_selected_frame (void *);
83 static int follow_fork (void);
85 static int follow_fork_inferior (int follow_child, int detach_fork);
87 static void follow_inferior_reset_breakpoints (void);
89 static void set_schedlock_func (char *args, int from_tty,
90 struct cmd_list_element *c);
92 static int currently_stepping (struct thread_info *tp);
94 void _initialize_infrun (void);
96 void nullify_last_target_wait_ptid (void);
98 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
100 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
102 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
104 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
106 /* Asynchronous signal handler registered as event loop source for
107 when we have pending events ready to be passed to the core. */
108 static struct async_event_handler *infrun_async_inferior_event_token;
110 /* Stores whether infrun_async was previously enabled or disabled.
111 Starts off as -1, indicating "never enabled/disabled". */
112 static int infrun_is_async = -1;
117 infrun_async (int enable)
119 if (infrun_is_async != enable)
121 infrun_is_async = enable;
124 fprintf_unfiltered (gdb_stdlog,
125 "infrun: infrun_async(%d)\n",
129 mark_async_event_handler (infrun_async_inferior_event_token);
131 clear_async_event_handler (infrun_async_inferior_event_token);
138 mark_infrun_async_event_handler (void)
140 mark_async_event_handler (infrun_async_inferior_event_token);
143 /* When set, stop the 'step' command if we enter a function which has
144 no line number information. The normal behavior is that we step
145 over such function. */
146 int step_stop_if_no_debug = 0;
148 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
149 struct cmd_list_element *c, const char *value)
151 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
154 /* In asynchronous mode, but simulating synchronous execution. */
156 int sync_execution = 0;
158 /* proceed and normal_stop use this to notify the user when the
159 inferior stopped in a different thread than it had been running
162 static ptid_t previous_inferior_ptid;
164 /* If set (default for legacy reasons), when following a fork, GDB
165 will detach from one of the fork branches, child or parent.
166 Exactly which branch is detached depends on 'set follow-fork-mode'
169 static int detach_fork = 1;
171 int debug_displaced = 0;
173 show_debug_displaced (struct ui_file *file, int from_tty,
174 struct cmd_list_element *c, const char *value)
176 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
179 unsigned int debug_infrun = 0;
181 show_debug_infrun (struct ui_file *file, int from_tty,
182 struct cmd_list_element *c, const char *value)
184 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
188 /* Support for disabling address space randomization. */
190 int disable_randomization = 1;
193 show_disable_randomization (struct ui_file *file, int from_tty,
194 struct cmd_list_element *c, const char *value)
196 if (target_supports_disable_randomization ())
197 fprintf_filtered (file,
198 _("Disabling randomization of debuggee's "
199 "virtual address space is %s.\n"),
202 fputs_filtered (_("Disabling randomization of debuggee's "
203 "virtual address space is unsupported on\n"
204 "this platform.\n"), file);
208 set_disable_randomization (char *args, int from_tty,
209 struct cmd_list_element *c)
211 if (!target_supports_disable_randomization ())
212 error (_("Disabling randomization of debuggee's "
213 "virtual address space is unsupported on\n"
217 /* User interface for non-stop mode. */
220 static int non_stop_1 = 0;
223 set_non_stop (char *args, int from_tty,
224 struct cmd_list_element *c)
226 if (target_has_execution)
228 non_stop_1 = non_stop;
229 error (_("Cannot change this setting while the inferior is running."));
232 non_stop = non_stop_1;
236 show_non_stop (struct ui_file *file, int from_tty,
237 struct cmd_list_element *c, const char *value)
239 fprintf_filtered (file,
240 _("Controlling the inferior in non-stop mode is %s.\n"),
244 /* "Observer mode" is somewhat like a more extreme version of
245 non-stop, in which all GDB operations that might affect the
246 target's execution have been disabled. */
248 int observer_mode = 0;
249 static int observer_mode_1 = 0;
252 set_observer_mode (char *args, int from_tty,
253 struct cmd_list_element *c)
255 if (target_has_execution)
257 observer_mode_1 = observer_mode;
258 error (_("Cannot change this setting while the inferior is running."));
261 observer_mode = observer_mode_1;
263 may_write_registers = !observer_mode;
264 may_write_memory = !observer_mode;
265 may_insert_breakpoints = !observer_mode;
266 may_insert_tracepoints = !observer_mode;
267 /* We can insert fast tracepoints in or out of observer mode,
268 but enable them if we're going into this mode. */
270 may_insert_fast_tracepoints = 1;
271 may_stop = !observer_mode;
272 update_target_permissions ();
274 /* Going *into* observer mode we must force non-stop, then
275 going out we leave it that way. */
278 pagination_enabled = 0;
279 non_stop = non_stop_1 = 1;
283 printf_filtered (_("Observer mode is now %s.\n"),
284 (observer_mode ? "on" : "off"));
288 show_observer_mode (struct ui_file *file, int from_tty,
289 struct cmd_list_element *c, const char *value)
291 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
294 /* This updates the value of observer mode based on changes in
295 permissions. Note that we are deliberately ignoring the values of
296 may-write-registers and may-write-memory, since the user may have
297 reason to enable these during a session, for instance to turn on a
298 debugging-related global. */
301 update_observer_mode (void)
305 newval = (!may_insert_breakpoints
306 && !may_insert_tracepoints
307 && may_insert_fast_tracepoints
311 /* Let the user know if things change. */
312 if (newval != observer_mode)
313 printf_filtered (_("Observer mode is now %s.\n"),
314 (newval ? "on" : "off"));
316 observer_mode = observer_mode_1 = newval;
319 /* Tables of how to react to signals; the user sets them. */
321 static unsigned char *signal_stop;
322 static unsigned char *signal_print;
323 static unsigned char *signal_program;
325 /* Table of signals that are registered with "catch signal". A
326 non-zero entry indicates that the signal is caught by some "catch
327 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
329 static unsigned char *signal_catch;
331 /* Table of signals that the target may silently handle.
332 This is automatically determined from the flags above,
333 and simply cached here. */
334 static unsigned char *signal_pass;
336 #define SET_SIGS(nsigs,sigs,flags) \
338 int signum = (nsigs); \
339 while (signum-- > 0) \
340 if ((sigs)[signum]) \
341 (flags)[signum] = 1; \
344 #define UNSET_SIGS(nsigs,sigs,flags) \
346 int signum = (nsigs); \
347 while (signum-- > 0) \
348 if ((sigs)[signum]) \
349 (flags)[signum] = 0; \
352 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
353 this function is to avoid exporting `signal_program'. */
356 update_signals_program_target (void)
358 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
361 /* Value to pass to target_resume() to cause all threads to resume. */
363 #define RESUME_ALL minus_one_ptid
365 /* Command list pointer for the "stop" placeholder. */
367 static struct cmd_list_element *stop_command;
369 /* Nonzero if we want to give control to the user when we're notified
370 of shared library events by the dynamic linker. */
371 int stop_on_solib_events;
373 /* Enable or disable optional shared library event breakpoints
374 as appropriate when the above flag is changed. */
377 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
379 update_solib_breakpoints ();
383 show_stop_on_solib_events (struct ui_file *file, int from_tty,
384 struct cmd_list_element *c, const char *value)
386 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
390 /* Nonzero means expecting a trace trap
391 and should stop the inferior and return silently when it happens. */
395 /* Nonzero after stop if current stack frame should be printed. */
397 static int stop_print_frame;
399 /* This is a cached copy of the pid/waitstatus of the last event
400 returned by target_wait()/deprecated_target_wait_hook(). This
401 information is returned by get_last_target_status(). */
402 static ptid_t target_last_wait_ptid;
403 static struct target_waitstatus target_last_waitstatus;
405 static void context_switch (ptid_t ptid);
407 void init_thread_stepping_state (struct thread_info *tss);
409 static const char follow_fork_mode_child[] = "child";
410 static const char follow_fork_mode_parent[] = "parent";
412 static const char *const follow_fork_mode_kind_names[] = {
413 follow_fork_mode_child,
414 follow_fork_mode_parent,
418 static const char *follow_fork_mode_string = follow_fork_mode_parent;
420 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
421 struct cmd_list_element *c, const char *value)
423 fprintf_filtered (file,
424 _("Debugger response to a program "
425 "call of fork or vfork is \"%s\".\n"),
430 /* Handle changes to the inferior list based on the type of fork,
431 which process is being followed, and whether the other process
432 should be detached. On entry inferior_ptid must be the ptid of
433 the fork parent. At return inferior_ptid is the ptid of the
434 followed inferior. */
437 follow_fork_inferior (int follow_child, int detach_fork)
440 ptid_t parent_ptid, child_ptid;
442 has_vforked = (inferior_thread ()->pending_follow.kind
443 == TARGET_WAITKIND_VFORKED);
444 parent_ptid = inferior_ptid;
445 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
448 && !non_stop /* Non-stop always resumes both branches. */
449 && (!target_is_async_p () || sync_execution)
450 && !(follow_child || detach_fork || sched_multi))
452 /* The parent stays blocked inside the vfork syscall until the
453 child execs or exits. If we don't let the child run, then
454 the parent stays blocked. If we're telling the parent to run
455 in the foreground, the user will not be able to ctrl-c to get
456 back the terminal, effectively hanging the debug session. */
457 fprintf_filtered (gdb_stderr, _("\
458 Can not resume the parent process over vfork in the foreground while\n\
459 holding the child stopped. Try \"set detach-on-fork\" or \
460 \"set schedule-multiple\".\n"));
461 /* FIXME output string > 80 columns. */
467 /* Detach new forked process? */
470 struct cleanup *old_chain;
472 /* Before detaching from the child, remove all breakpoints
473 from it. If we forked, then this has already been taken
474 care of by infrun.c. If we vforked however, any
475 breakpoint inserted in the parent is visible in the
476 child, even those added while stopped in a vfork
477 catchpoint. This will remove the breakpoints from the
478 parent also, but they'll be reinserted below. */
481 /* Keep breakpoints list in sync. */
482 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
485 if (info_verbose || debug_infrun)
487 /* Ensure that we have a process ptid. */
488 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
490 target_terminal_ours_for_output ();
491 fprintf_filtered (gdb_stdlog,
492 _("Detaching after %s from child %s.\n"),
493 has_vforked ? "vfork" : "fork",
494 target_pid_to_str (process_ptid));
499 struct inferior *parent_inf, *child_inf;
500 struct cleanup *old_chain;
502 /* Add process to GDB's tables. */
503 child_inf = add_inferior (ptid_get_pid (child_ptid));
505 parent_inf = current_inferior ();
506 child_inf->attach_flag = parent_inf->attach_flag;
507 copy_terminal_info (child_inf, parent_inf);
508 child_inf->gdbarch = parent_inf->gdbarch;
509 copy_inferior_target_desc_info (child_inf, parent_inf);
511 old_chain = save_inferior_ptid ();
512 save_current_program_space ();
514 inferior_ptid = child_ptid;
515 add_thread (inferior_ptid);
516 child_inf->symfile_flags = SYMFILE_NO_READ;
518 /* If this is a vfork child, then the address-space is
519 shared with the parent. */
522 child_inf->pspace = parent_inf->pspace;
523 child_inf->aspace = parent_inf->aspace;
525 /* The parent will be frozen until the child is done
526 with the shared region. Keep track of the
528 child_inf->vfork_parent = parent_inf;
529 child_inf->pending_detach = 0;
530 parent_inf->vfork_child = child_inf;
531 parent_inf->pending_detach = 0;
535 child_inf->aspace = new_address_space ();
536 child_inf->pspace = add_program_space (child_inf->aspace);
537 child_inf->removable = 1;
538 set_current_program_space (child_inf->pspace);
539 clone_program_space (child_inf->pspace, parent_inf->pspace);
541 /* Let the shared library layer (e.g., solib-svr4) learn
542 about this new process, relocate the cloned exec, pull
543 in shared libraries, and install the solib event
544 breakpoint. If a "cloned-VM" event was propagated
545 better throughout the core, this wouldn't be
547 solib_create_inferior_hook (0);
550 do_cleanups (old_chain);
555 struct inferior *parent_inf;
557 parent_inf = current_inferior ();
559 /* If we detached from the child, then we have to be careful
560 to not insert breakpoints in the parent until the child
561 is done with the shared memory region. However, if we're
562 staying attached to the child, then we can and should
563 insert breakpoints, so that we can debug it. A
564 subsequent child exec or exit is enough to know when does
565 the child stops using the parent's address space. */
566 parent_inf->waiting_for_vfork_done = detach_fork;
567 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
572 /* Follow the child. */
573 struct inferior *parent_inf, *child_inf;
574 struct program_space *parent_pspace;
576 if (info_verbose || debug_infrun)
578 target_terminal_ours_for_output ();
579 fprintf_filtered (gdb_stdlog,
580 _("Attaching after %s %s to child %s.\n"),
581 target_pid_to_str (parent_ptid),
582 has_vforked ? "vfork" : "fork",
583 target_pid_to_str (child_ptid));
586 /* Add the new inferior first, so that the target_detach below
587 doesn't unpush the target. */
589 child_inf = add_inferior (ptid_get_pid (child_ptid));
591 parent_inf = current_inferior ();
592 child_inf->attach_flag = parent_inf->attach_flag;
593 copy_terminal_info (child_inf, parent_inf);
594 child_inf->gdbarch = parent_inf->gdbarch;
595 copy_inferior_target_desc_info (child_inf, parent_inf);
597 parent_pspace = parent_inf->pspace;
599 /* If we're vforking, we want to hold on to the parent until the
600 child exits or execs. At child exec or exit time we can
601 remove the old breakpoints from the parent and detach or
602 resume debugging it. Otherwise, detach the parent now; we'll
603 want to reuse it's program/address spaces, but we can't set
604 them to the child before removing breakpoints from the
605 parent, otherwise, the breakpoints module could decide to
606 remove breakpoints from the wrong process (since they'd be
607 assigned to the same address space). */
611 gdb_assert (child_inf->vfork_parent == NULL);
612 gdb_assert (parent_inf->vfork_child == NULL);
613 child_inf->vfork_parent = parent_inf;
614 child_inf->pending_detach = 0;
615 parent_inf->vfork_child = child_inf;
616 parent_inf->pending_detach = detach_fork;
617 parent_inf->waiting_for_vfork_done = 0;
619 else if (detach_fork)
621 if (info_verbose || debug_infrun)
623 /* Ensure that we have a process ptid. */
624 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
626 target_terminal_ours_for_output ();
627 fprintf_filtered (gdb_stdlog,
628 _("Detaching after fork from "
630 target_pid_to_str (process_ptid));
633 target_detach (NULL, 0);
636 /* Note that the detach above makes PARENT_INF dangling. */
638 /* Add the child thread to the appropriate lists, and switch to
639 this new thread, before cloning the program space, and
640 informing the solib layer about this new process. */
642 inferior_ptid = child_ptid;
643 add_thread (inferior_ptid);
645 /* If this is a vfork child, then the address-space is shared
646 with the parent. If we detached from the parent, then we can
647 reuse the parent's program/address spaces. */
648 if (has_vforked || detach_fork)
650 child_inf->pspace = parent_pspace;
651 child_inf->aspace = child_inf->pspace->aspace;
655 child_inf->aspace = new_address_space ();
656 child_inf->pspace = add_program_space (child_inf->aspace);
657 child_inf->removable = 1;
658 child_inf->symfile_flags = SYMFILE_NO_READ;
659 set_current_program_space (child_inf->pspace);
660 clone_program_space (child_inf->pspace, parent_pspace);
662 /* Let the shared library layer (e.g., solib-svr4) learn
663 about this new process, relocate the cloned exec, pull in
664 shared libraries, and install the solib event breakpoint.
665 If a "cloned-VM" event was propagated better throughout
666 the core, this wouldn't be required. */
667 solib_create_inferior_hook (0);
671 return target_follow_fork (follow_child, detach_fork);
674 /* Tell the target to follow the fork we're stopped at. Returns true
675 if the inferior should be resumed; false, if the target for some
676 reason decided it's best not to resume. */
681 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
682 int should_resume = 1;
683 struct thread_info *tp;
685 /* Copy user stepping state to the new inferior thread. FIXME: the
686 followed fork child thread should have a copy of most of the
687 parent thread structure's run control related fields, not just these.
688 Initialized to avoid "may be used uninitialized" warnings from gcc. */
689 struct breakpoint *step_resume_breakpoint = NULL;
690 struct breakpoint *exception_resume_breakpoint = NULL;
691 CORE_ADDR step_range_start = 0;
692 CORE_ADDR step_range_end = 0;
693 struct frame_id step_frame_id = { 0 };
694 struct interp *command_interp = NULL;
699 struct target_waitstatus wait_status;
701 /* Get the last target status returned by target_wait(). */
702 get_last_target_status (&wait_ptid, &wait_status);
704 /* If not stopped at a fork event, then there's nothing else to
706 if (wait_status.kind != TARGET_WAITKIND_FORKED
707 && wait_status.kind != TARGET_WAITKIND_VFORKED)
710 /* Check if we switched over from WAIT_PTID, since the event was
712 if (!ptid_equal (wait_ptid, minus_one_ptid)
713 && !ptid_equal (inferior_ptid, wait_ptid))
715 /* We did. Switch back to WAIT_PTID thread, to tell the
716 target to follow it (in either direction). We'll
717 afterwards refuse to resume, and inform the user what
719 switch_to_thread (wait_ptid);
724 tp = inferior_thread ();
726 /* If there were any forks/vforks that were caught and are now to be
727 followed, then do so now. */
728 switch (tp->pending_follow.kind)
730 case TARGET_WAITKIND_FORKED:
731 case TARGET_WAITKIND_VFORKED:
733 ptid_t parent, child;
735 /* If the user did a next/step, etc, over a fork call,
736 preserve the stepping state in the fork child. */
737 if (follow_child && should_resume)
739 step_resume_breakpoint = clone_momentary_breakpoint
740 (tp->control.step_resume_breakpoint);
741 step_range_start = tp->control.step_range_start;
742 step_range_end = tp->control.step_range_end;
743 step_frame_id = tp->control.step_frame_id;
744 exception_resume_breakpoint
745 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
746 command_interp = tp->control.command_interp;
748 /* For now, delete the parent's sr breakpoint, otherwise,
749 parent/child sr breakpoints are considered duplicates,
750 and the child version will not be installed. Remove
751 this when the breakpoints module becomes aware of
752 inferiors and address spaces. */
753 delete_step_resume_breakpoint (tp);
754 tp->control.step_range_start = 0;
755 tp->control.step_range_end = 0;
756 tp->control.step_frame_id = null_frame_id;
757 delete_exception_resume_breakpoint (tp);
758 tp->control.command_interp = NULL;
761 parent = inferior_ptid;
762 child = tp->pending_follow.value.related_pid;
764 /* Set up inferior(s) as specified by the caller, and tell the
765 target to do whatever is necessary to follow either parent
767 if (follow_fork_inferior (follow_child, detach_fork))
769 /* Target refused to follow, or there's some other reason
770 we shouldn't resume. */
775 /* This pending follow fork event is now handled, one way
776 or another. The previous selected thread may be gone
777 from the lists by now, but if it is still around, need
778 to clear the pending follow request. */
779 tp = find_thread_ptid (parent);
781 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
783 /* This makes sure we don't try to apply the "Switched
784 over from WAIT_PID" logic above. */
785 nullify_last_target_wait_ptid ();
787 /* If we followed the child, switch to it... */
790 switch_to_thread (child);
792 /* ... and preserve the stepping state, in case the
793 user was stepping over the fork call. */
796 tp = inferior_thread ();
797 tp->control.step_resume_breakpoint
798 = step_resume_breakpoint;
799 tp->control.step_range_start = step_range_start;
800 tp->control.step_range_end = step_range_end;
801 tp->control.step_frame_id = step_frame_id;
802 tp->control.exception_resume_breakpoint
803 = exception_resume_breakpoint;
804 tp->control.command_interp = command_interp;
808 /* If we get here, it was because we're trying to
809 resume from a fork catchpoint, but, the user
810 has switched threads away from the thread that
811 forked. In that case, the resume command
812 issued is most likely not applicable to the
813 child, so just warn, and refuse to resume. */
814 warning (_("Not resuming: switched threads "
815 "before following fork child."));
818 /* Reset breakpoints in the child as appropriate. */
819 follow_inferior_reset_breakpoints ();
822 switch_to_thread (parent);
826 case TARGET_WAITKIND_SPURIOUS:
827 /* Nothing to follow. */
830 internal_error (__FILE__, __LINE__,
831 "Unexpected pending_follow.kind %d\n",
832 tp->pending_follow.kind);
836 return should_resume;
840 follow_inferior_reset_breakpoints (void)
842 struct thread_info *tp = inferior_thread ();
844 /* Was there a step_resume breakpoint? (There was if the user
845 did a "next" at the fork() call.) If so, explicitly reset its
846 thread number. Cloned step_resume breakpoints are disabled on
847 creation, so enable it here now that it is associated with the
850 step_resumes are a form of bp that are made to be per-thread.
851 Since we created the step_resume bp when the parent process
852 was being debugged, and now are switching to the child process,
853 from the breakpoint package's viewpoint, that's a switch of
854 "threads". We must update the bp's notion of which thread
855 it is for, or it'll be ignored when it triggers. */
857 if (tp->control.step_resume_breakpoint)
859 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
860 tp->control.step_resume_breakpoint->loc->enabled = 1;
863 /* Treat exception_resume breakpoints like step_resume breakpoints. */
864 if (tp->control.exception_resume_breakpoint)
866 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
867 tp->control.exception_resume_breakpoint->loc->enabled = 1;
870 /* Reinsert all breakpoints in the child. The user may have set
871 breakpoints after catching the fork, in which case those
872 were never set in the child, but only in the parent. This makes
873 sure the inserted breakpoints match the breakpoint list. */
875 breakpoint_re_set ();
876 insert_breakpoints ();
879 /* The child has exited or execed: resume threads of the parent the
880 user wanted to be executing. */
883 proceed_after_vfork_done (struct thread_info *thread,
886 int pid = * (int *) arg;
888 if (ptid_get_pid (thread->ptid) == pid
889 && is_running (thread->ptid)
890 && !is_executing (thread->ptid)
891 && !thread->stop_requested
892 && thread->suspend.stop_signal == GDB_SIGNAL_0)
895 fprintf_unfiltered (gdb_stdlog,
896 "infrun: resuming vfork parent thread %s\n",
897 target_pid_to_str (thread->ptid));
899 switch_to_thread (thread->ptid);
900 clear_proceed_status (0);
901 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
907 /* Called whenever we notice an exec or exit event, to handle
908 detaching or resuming a vfork parent. */
911 handle_vfork_child_exec_or_exit (int exec)
913 struct inferior *inf = current_inferior ();
915 if (inf->vfork_parent)
917 int resume_parent = -1;
919 /* This exec or exit marks the end of the shared memory region
920 between the parent and the child. If the user wanted to
921 detach from the parent, now is the time. */
923 if (inf->vfork_parent->pending_detach)
925 struct thread_info *tp;
926 struct cleanup *old_chain;
927 struct program_space *pspace;
928 struct address_space *aspace;
930 /* follow-fork child, detach-on-fork on. */
932 inf->vfork_parent->pending_detach = 0;
936 /* If we're handling a child exit, then inferior_ptid
937 points at the inferior's pid, not to a thread. */
938 old_chain = save_inferior_ptid ();
939 save_current_program_space ();
940 save_current_inferior ();
943 old_chain = save_current_space_and_thread ();
945 /* We're letting loose of the parent. */
946 tp = any_live_thread_of_process (inf->vfork_parent->pid);
947 switch_to_thread (tp->ptid);
949 /* We're about to detach from the parent, which implicitly
950 removes breakpoints from its address space. There's a
951 catch here: we want to reuse the spaces for the child,
952 but, parent/child are still sharing the pspace at this
953 point, although the exec in reality makes the kernel give
954 the child a fresh set of new pages. The problem here is
955 that the breakpoints module being unaware of this, would
956 likely chose the child process to write to the parent
957 address space. Swapping the child temporarily away from
958 the spaces has the desired effect. Yes, this is "sort
961 pspace = inf->pspace;
962 aspace = inf->aspace;
966 if (debug_infrun || info_verbose)
968 target_terminal_ours_for_output ();
972 fprintf_filtered (gdb_stdlog,
973 _("Detaching vfork parent process "
974 "%d after child exec.\n"),
975 inf->vfork_parent->pid);
979 fprintf_filtered (gdb_stdlog,
980 _("Detaching vfork parent process "
981 "%d after child exit.\n"),
982 inf->vfork_parent->pid);
986 target_detach (NULL, 0);
989 inf->pspace = pspace;
990 inf->aspace = aspace;
992 do_cleanups (old_chain);
996 /* We're staying attached to the parent, so, really give the
997 child a new address space. */
998 inf->pspace = add_program_space (maybe_new_address_space ());
999 inf->aspace = inf->pspace->aspace;
1001 set_current_program_space (inf->pspace);
1003 resume_parent = inf->vfork_parent->pid;
1005 /* Break the bonds. */
1006 inf->vfork_parent->vfork_child = NULL;
1010 struct cleanup *old_chain;
1011 struct program_space *pspace;
1013 /* If this is a vfork child exiting, then the pspace and
1014 aspaces were shared with the parent. Since we're
1015 reporting the process exit, we'll be mourning all that is
1016 found in the address space, and switching to null_ptid,
1017 preparing to start a new inferior. But, since we don't
1018 want to clobber the parent's address/program spaces, we
1019 go ahead and create a new one for this exiting
1022 /* Switch to null_ptid, so that clone_program_space doesn't want
1023 to read the selected frame of a dead process. */
1024 old_chain = save_inferior_ptid ();
1025 inferior_ptid = null_ptid;
1027 /* This inferior is dead, so avoid giving the breakpoints
1028 module the option to write through to it (cloning a
1029 program space resets breakpoints). */
1032 pspace = add_program_space (maybe_new_address_space ());
1033 set_current_program_space (pspace);
1035 inf->symfile_flags = SYMFILE_NO_READ;
1036 clone_program_space (pspace, inf->vfork_parent->pspace);
1037 inf->pspace = pspace;
1038 inf->aspace = pspace->aspace;
1040 /* Put back inferior_ptid. We'll continue mourning this
1042 do_cleanups (old_chain);
1044 resume_parent = inf->vfork_parent->pid;
1045 /* Break the bonds. */
1046 inf->vfork_parent->vfork_child = NULL;
1049 inf->vfork_parent = NULL;
1051 gdb_assert (current_program_space == inf->pspace);
1053 if (non_stop && resume_parent != -1)
1055 /* If the user wanted the parent to be running, let it go
1057 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
1060 fprintf_unfiltered (gdb_stdlog,
1061 "infrun: resuming vfork parent process %d\n",
1064 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1066 do_cleanups (old_chain);
1071 /* Enum strings for "set|show follow-exec-mode". */
1073 static const char follow_exec_mode_new[] = "new";
1074 static const char follow_exec_mode_same[] = "same";
1075 static const char *const follow_exec_mode_names[] =
1077 follow_exec_mode_new,
1078 follow_exec_mode_same,
1082 static const char *follow_exec_mode_string = follow_exec_mode_same;
1084 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1085 struct cmd_list_element *c, const char *value)
1087 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1090 /* EXECD_PATHNAME is assumed to be non-NULL. */
1093 follow_exec (ptid_t ptid, char *execd_pathname)
1095 struct thread_info *th, *tmp;
1096 struct inferior *inf = current_inferior ();
1097 int pid = ptid_get_pid (ptid);
1098 ptid_t process_ptid;
1100 /* This is an exec event that we actually wish to pay attention to.
1101 Refresh our symbol table to the newly exec'd program, remove any
1102 momentary bp's, etc.
1104 If there are breakpoints, they aren't really inserted now,
1105 since the exec() transformed our inferior into a fresh set
1108 We want to preserve symbolic breakpoints on the list, since
1109 we have hopes that they can be reset after the new a.out's
1110 symbol table is read.
1112 However, any "raw" breakpoints must be removed from the list
1113 (e.g., the solib bp's), since their address is probably invalid
1116 And, we DON'T want to call delete_breakpoints() here, since
1117 that may write the bp's "shadow contents" (the instruction
1118 value that was overwritten witha TRAP instruction). Since
1119 we now have a new a.out, those shadow contents aren't valid. */
1121 mark_breakpoints_out ();
1123 /* The target reports the exec event to the main thread, even if
1124 some other thread does the exec, and even if the main thread was
1125 stopped or already gone. We may still have non-leader threads of
1126 the process on our list. E.g., on targets that don't have thread
1127 exit events (like remote); or on native Linux in non-stop mode if
1128 there were only two threads in the inferior and the non-leader
1129 one is the one that execs (and nothing forces an update of the
1130 thread list up to here). When debugging remotely, it's best to
1131 avoid extra traffic, when possible, so avoid syncing the thread
1132 list with the target, and instead go ahead and delete all threads
1133 of the process but one that reported the event. Note this must
1134 be done before calling update_breakpoints_after_exec, as
1135 otherwise clearing the threads' resources would reference stale
1136 thread breakpoints -- it may have been one of these threads that
1137 stepped across the exec. We could just clear their stepping
1138 states, but as long as we're iterating, might as well delete
1139 them. Deleting them now rather than at the next user-visible
1140 stop provides a nicer sequence of events for user and MI
1142 ALL_THREADS_SAFE (th, tmp)
1143 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1144 delete_thread (th->ptid);
1146 /* We also need to clear any left over stale state for the
1147 leader/event thread. E.g., if there was any step-resume
1148 breakpoint or similar, it's gone now. We cannot truly
1149 step-to-next statement through an exec(). */
1150 th = inferior_thread ();
1151 th->control.step_resume_breakpoint = NULL;
1152 th->control.exception_resume_breakpoint = NULL;
1153 th->control.single_step_breakpoints = NULL;
1154 th->control.step_range_start = 0;
1155 th->control.step_range_end = 0;
1157 /* The user may have had the main thread held stopped in the
1158 previous image (e.g., schedlock on, or non-stop). Release
1160 th->stop_requested = 0;
1162 update_breakpoints_after_exec ();
1164 /* What is this a.out's name? */
1165 process_ptid = pid_to_ptid (pid);
1166 printf_unfiltered (_("%s is executing new program: %s\n"),
1167 target_pid_to_str (process_ptid),
1170 /* We've followed the inferior through an exec. Therefore, the
1171 inferior has essentially been killed & reborn. */
1173 gdb_flush (gdb_stdout);
1175 breakpoint_init_inferior (inf_execd);
1177 if (*gdb_sysroot != '\0')
1179 char *name = exec_file_find (execd_pathname, NULL);
1181 execd_pathname = alloca (strlen (name) + 1);
1182 strcpy (execd_pathname, name);
1186 /* Reset the shared library package. This ensures that we get a
1187 shlib event when the child reaches "_start", at which point the
1188 dld will have had a chance to initialize the child. */
1189 /* Also, loading a symbol file below may trigger symbol lookups, and
1190 we don't want those to be satisfied by the libraries of the
1191 previous incarnation of this process. */
1192 no_shared_libraries (NULL, 0);
1194 if (follow_exec_mode_string == follow_exec_mode_new)
1196 /* The user wants to keep the old inferior and program spaces
1197 around. Create a new fresh one, and switch to it. */
1199 /* Do exit processing for the original inferior before adding
1200 the new inferior so we don't have two active inferiors with
1201 the same ptid, which can confuse find_inferior_ptid. */
1202 exit_inferior_num_silent (current_inferior ()->num);
1204 inf = add_inferior_with_spaces ();
1206 target_follow_exec (inf, execd_pathname);
1208 set_current_inferior (inf);
1209 set_current_program_space (inf->pspace);
1214 /* The old description may no longer be fit for the new image.
1215 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1216 old description; we'll read a new one below. No need to do
1217 this on "follow-exec-mode new", as the old inferior stays
1218 around (its description is later cleared/refetched on
1220 target_clear_description ();
1223 gdb_assert (current_program_space == inf->pspace);
1225 /* That a.out is now the one to use. */
1226 exec_file_attach (execd_pathname, 0);
1228 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
1229 (Position Independent Executable) main symbol file will get applied by
1230 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
1231 the breakpoints with the zero displacement. */
1233 symbol_file_add (execd_pathname,
1235 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
1238 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
1239 set_initial_language ();
1241 /* If the target can specify a description, read it. Must do this
1242 after flipping to the new executable (because the target supplied
1243 description must be compatible with the executable's
1244 architecture, and the old executable may e.g., be 32-bit, while
1245 the new one 64-bit), and before anything involving memory or
1247 target_find_description ();
1249 solib_create_inferior_hook (0);
1251 jit_inferior_created_hook ();
1253 breakpoint_re_set ();
1255 /* Reinsert all breakpoints. (Those which were symbolic have
1256 been reset to the proper address in the new a.out, thanks
1257 to symbol_file_command...). */
1258 insert_breakpoints ();
1260 /* The next resume of this inferior should bring it to the shlib
1261 startup breakpoints. (If the user had also set bp's on
1262 "main" from the old (parent) process, then they'll auto-
1263 matically get reset there in the new process.). */
1266 /* The queue of threads that need to do a step-over operation to get
1267 past e.g., a breakpoint. What technique is used to step over the
1268 breakpoint/watchpoint does not matter -- all threads end up in the
1269 same queue, to maintain rough temporal order of execution, in order
1270 to avoid starvation, otherwise, we could e.g., find ourselves
1271 constantly stepping the same couple threads past their breakpoints
1272 over and over, if the single-step finish fast enough. */
1273 struct thread_info *step_over_queue_head;
1275 /* Bit flags indicating what the thread needs to step over. */
1279 /* Step over a breakpoint. */
1280 STEP_OVER_BREAKPOINT = 1,
1282 /* Step past a non-continuable watchpoint, in order to let the
1283 instruction execute so we can evaluate the watchpoint
1285 STEP_OVER_WATCHPOINT = 2
1288 /* Info about an instruction that is being stepped over. */
1290 struct step_over_info
1292 /* If we're stepping past a breakpoint, this is the address space
1293 and address of the instruction the breakpoint is set at. We'll
1294 skip inserting all breakpoints here. Valid iff ASPACE is
1296 struct address_space *aspace;
1299 /* The instruction being stepped over triggers a nonsteppable
1300 watchpoint. If true, we'll skip inserting watchpoints. */
1301 int nonsteppable_watchpoint_p;
1304 /* The step-over info of the location that is being stepped over.
1306 Note that with async/breakpoint always-inserted mode, a user might
1307 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1308 being stepped over. As setting a new breakpoint inserts all
1309 breakpoints, we need to make sure the breakpoint being stepped over
1310 isn't inserted then. We do that by only clearing the step-over
1311 info when the step-over is actually finished (or aborted).
1313 Presently GDB can only step over one breakpoint at any given time.
1314 Given threads that can't run code in the same address space as the
1315 breakpoint's can't really miss the breakpoint, GDB could be taught
1316 to step-over at most one breakpoint per address space (so this info
1317 could move to the address space object if/when GDB is extended).
1318 The set of breakpoints being stepped over will normally be much
1319 smaller than the set of all breakpoints, so a flag in the
1320 breakpoint location structure would be wasteful. A separate list
1321 also saves complexity and run-time, as otherwise we'd have to go
1322 through all breakpoint locations clearing their flag whenever we
1323 start a new sequence. Similar considerations weigh against storing
1324 this info in the thread object. Plus, not all step overs actually
1325 have breakpoint locations -- e.g., stepping past a single-step
1326 breakpoint, or stepping to complete a non-continuable
1328 static struct step_over_info step_over_info;
1330 /* Record the address of the breakpoint/instruction we're currently
1334 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1335 int nonsteppable_watchpoint_p)
1337 step_over_info.aspace = aspace;
1338 step_over_info.address = address;
1339 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1342 /* Called when we're not longer stepping over a breakpoint / an
1343 instruction, so all breakpoints are free to be (re)inserted. */
1346 clear_step_over_info (void)
1349 fprintf_unfiltered (gdb_stdlog,
1350 "infrun: clear_step_over_info\n");
1351 step_over_info.aspace = NULL;
1352 step_over_info.address = 0;
1353 step_over_info.nonsteppable_watchpoint_p = 0;
1359 stepping_past_instruction_at (struct address_space *aspace,
1362 return (step_over_info.aspace != NULL
1363 && breakpoint_address_match (aspace, address,
1364 step_over_info.aspace,
1365 step_over_info.address));
1371 stepping_past_nonsteppable_watchpoint (void)
1373 return step_over_info.nonsteppable_watchpoint_p;
1376 /* Returns true if step-over info is valid. */
1379 step_over_info_valid_p (void)
1381 return (step_over_info.aspace != NULL
1382 || stepping_past_nonsteppable_watchpoint ());
1386 /* Displaced stepping. */
1388 /* In non-stop debugging mode, we must take special care to manage
1389 breakpoints properly; in particular, the traditional strategy for
1390 stepping a thread past a breakpoint it has hit is unsuitable.
1391 'Displaced stepping' is a tactic for stepping one thread past a
1392 breakpoint it has hit while ensuring that other threads running
1393 concurrently will hit the breakpoint as they should.
1395 The traditional way to step a thread T off a breakpoint in a
1396 multi-threaded program in all-stop mode is as follows:
1398 a0) Initially, all threads are stopped, and breakpoints are not
1400 a1) We single-step T, leaving breakpoints uninserted.
1401 a2) We insert breakpoints, and resume all threads.
1403 In non-stop debugging, however, this strategy is unsuitable: we
1404 don't want to have to stop all threads in the system in order to
1405 continue or step T past a breakpoint. Instead, we use displaced
1408 n0) Initially, T is stopped, other threads are running, and
1409 breakpoints are inserted.
1410 n1) We copy the instruction "under" the breakpoint to a separate
1411 location, outside the main code stream, making any adjustments
1412 to the instruction, register, and memory state as directed by
1414 n2) We single-step T over the instruction at its new location.
1415 n3) We adjust the resulting register and memory state as directed
1416 by T's architecture. This includes resetting T's PC to point
1417 back into the main instruction stream.
1420 This approach depends on the following gdbarch methods:
1422 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1423 indicate where to copy the instruction, and how much space must
1424 be reserved there. We use these in step n1.
1426 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1427 address, and makes any necessary adjustments to the instruction,
1428 register contents, and memory. We use this in step n1.
1430 - gdbarch_displaced_step_fixup adjusts registers and memory after
1431 we have successfuly single-stepped the instruction, to yield the
1432 same effect the instruction would have had if we had executed it
1433 at its original address. We use this in step n3.
1435 - gdbarch_displaced_step_free_closure provides cleanup.
1437 The gdbarch_displaced_step_copy_insn and
1438 gdbarch_displaced_step_fixup functions must be written so that
1439 copying an instruction with gdbarch_displaced_step_copy_insn,
1440 single-stepping across the copied instruction, and then applying
1441 gdbarch_displaced_insn_fixup should have the same effects on the
1442 thread's memory and registers as stepping the instruction in place
1443 would have. Exactly which responsibilities fall to the copy and
1444 which fall to the fixup is up to the author of those functions.
1446 See the comments in gdbarch.sh for details.
1448 Note that displaced stepping and software single-step cannot
1449 currently be used in combination, although with some care I think
1450 they could be made to. Software single-step works by placing
1451 breakpoints on all possible subsequent instructions; if the
1452 displaced instruction is a PC-relative jump, those breakpoints
1453 could fall in very strange places --- on pages that aren't
1454 executable, or at addresses that are not proper instruction
1455 boundaries. (We do generally let other threads run while we wait
1456 to hit the software single-step breakpoint, and they might
1457 encounter such a corrupted instruction.) One way to work around
1458 this would be to have gdbarch_displaced_step_copy_insn fully
1459 simulate the effect of PC-relative instructions (and return NULL)
1460 on architectures that use software single-stepping.
1462 In non-stop mode, we can have independent and simultaneous step
1463 requests, so more than one thread may need to simultaneously step
1464 over a breakpoint. The current implementation assumes there is
1465 only one scratch space per process. In this case, we have to
1466 serialize access to the scratch space. If thread A wants to step
1467 over a breakpoint, but we are currently waiting for some other
1468 thread to complete a displaced step, we leave thread A stopped and
1469 place it in the displaced_step_request_queue. Whenever a displaced
1470 step finishes, we pick the next thread in the queue and start a new
1471 displaced step operation on it. See displaced_step_prepare and
1472 displaced_step_fixup for details. */
1474 /* Per-inferior displaced stepping state. */
1475 struct displaced_step_inferior_state
1477 /* Pointer to next in linked list. */
1478 struct displaced_step_inferior_state *next;
1480 /* The process this displaced step state refers to. */
1483 /* True if preparing a displaced step ever failed. If so, we won't
1484 try displaced stepping for this inferior again. */
1487 /* If this is not null_ptid, this is the thread carrying out a
1488 displaced single-step in process PID. This thread's state will
1489 require fixing up once it has completed its step. */
1492 /* The architecture the thread had when we stepped it. */
1493 struct gdbarch *step_gdbarch;
1495 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1496 for post-step cleanup. */
1497 struct displaced_step_closure *step_closure;
1499 /* The address of the original instruction, and the copy we
1501 CORE_ADDR step_original, step_copy;
1503 /* Saved contents of copy area. */
1504 gdb_byte *step_saved_copy;
1507 /* The list of states of processes involved in displaced stepping
1509 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1511 /* Get the displaced stepping state of process PID. */
1513 static struct displaced_step_inferior_state *
1514 get_displaced_stepping_state (int pid)
1516 struct displaced_step_inferior_state *state;
1518 for (state = displaced_step_inferior_states;
1520 state = state->next)
1521 if (state->pid == pid)
1527 /* Returns true if any inferior has a thread doing a displaced
1531 displaced_step_in_progress_any_inferior (void)
1533 struct displaced_step_inferior_state *state;
1535 for (state = displaced_step_inferior_states;
1537 state = state->next)
1538 if (!ptid_equal (state->step_ptid, null_ptid))
1544 /* Return true if process PID has a thread doing a displaced step. */
1547 displaced_step_in_progress (int pid)
1549 struct displaced_step_inferior_state *displaced;
1551 displaced = get_displaced_stepping_state (pid);
1552 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1558 /* Add a new displaced stepping state for process PID to the displaced
1559 stepping state list, or return a pointer to an already existing
1560 entry, if it already exists. Never returns NULL. */
1562 static struct displaced_step_inferior_state *
1563 add_displaced_stepping_state (int pid)
1565 struct displaced_step_inferior_state *state;
1567 for (state = displaced_step_inferior_states;
1569 state = state->next)
1570 if (state->pid == pid)
1573 state = XCNEW (struct displaced_step_inferior_state);
1575 state->next = displaced_step_inferior_states;
1576 displaced_step_inferior_states = state;
1581 /* If inferior is in displaced stepping, and ADDR equals to starting address
1582 of copy area, return corresponding displaced_step_closure. Otherwise,
1585 struct displaced_step_closure*
1586 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1588 struct displaced_step_inferior_state *displaced
1589 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1591 /* If checking the mode of displaced instruction in copy area. */
1592 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1593 && (displaced->step_copy == addr))
1594 return displaced->step_closure;
1599 /* Remove the displaced stepping state of process PID. */
1602 remove_displaced_stepping_state (int pid)
1604 struct displaced_step_inferior_state *it, **prev_next_p;
1606 gdb_assert (pid != 0);
1608 it = displaced_step_inferior_states;
1609 prev_next_p = &displaced_step_inferior_states;
1614 *prev_next_p = it->next;
1619 prev_next_p = &it->next;
1625 infrun_inferior_exit (struct inferior *inf)
1627 remove_displaced_stepping_state (inf->pid);
1630 /* If ON, and the architecture supports it, GDB will use displaced
1631 stepping to step over breakpoints. If OFF, or if the architecture
1632 doesn't support it, GDB will instead use the traditional
1633 hold-and-step approach. If AUTO (which is the default), GDB will
1634 decide which technique to use to step over breakpoints depending on
1635 which of all-stop or non-stop mode is active --- displaced stepping
1636 in non-stop mode; hold-and-step in all-stop mode. */
1638 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1641 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1642 struct cmd_list_element *c,
1645 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1646 fprintf_filtered (file,
1647 _("Debugger's willingness to use displaced stepping "
1648 "to step over breakpoints is %s (currently %s).\n"),
1649 value, target_is_non_stop_p () ? "on" : "off");
1651 fprintf_filtered (file,
1652 _("Debugger's willingness to use displaced stepping "
1653 "to step over breakpoints is %s.\n"), value);
1656 /* Return non-zero if displaced stepping can/should be used to step
1657 over breakpoints of thread TP. */
1660 use_displaced_stepping (struct thread_info *tp)
1662 struct regcache *regcache = get_thread_regcache (tp->ptid);
1663 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1664 struct displaced_step_inferior_state *displaced_state;
1666 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
1668 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1669 && target_is_non_stop_p ())
1670 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1671 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1672 && find_record_target () == NULL
1673 && (displaced_state == NULL
1674 || !displaced_state->failed_before));
1677 /* Clean out any stray displaced stepping state. */
1679 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1681 /* Indicate that there is no cleanup pending. */
1682 displaced->step_ptid = null_ptid;
1684 if (displaced->step_closure)
1686 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1687 displaced->step_closure);
1688 displaced->step_closure = NULL;
1693 displaced_step_clear_cleanup (void *arg)
1695 struct displaced_step_inferior_state *state = arg;
1697 displaced_step_clear (state);
1700 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1702 displaced_step_dump_bytes (struct ui_file *file,
1703 const gdb_byte *buf,
1708 for (i = 0; i < len; i++)
1709 fprintf_unfiltered (file, "%02x ", buf[i]);
1710 fputs_unfiltered ("\n", file);
1713 /* Prepare to single-step, using displaced stepping.
1715 Note that we cannot use displaced stepping when we have a signal to
1716 deliver. If we have a signal to deliver and an instruction to step
1717 over, then after the step, there will be no indication from the
1718 target whether the thread entered a signal handler or ignored the
1719 signal and stepped over the instruction successfully --- both cases
1720 result in a simple SIGTRAP. In the first case we mustn't do a
1721 fixup, and in the second case we must --- but we can't tell which.
1722 Comments in the code for 'random signals' in handle_inferior_event
1723 explain how we handle this case instead.
1725 Returns 1 if preparing was successful -- this thread is going to be
1726 stepped now; 0 if displaced stepping this thread got queued; or -1
1727 if this instruction can't be displaced stepped. */
1730 displaced_step_prepare_throw (ptid_t ptid)
1732 struct cleanup *old_cleanups, *ignore_cleanups;
1733 struct thread_info *tp = find_thread_ptid (ptid);
1734 struct regcache *regcache = get_thread_regcache (ptid);
1735 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1736 CORE_ADDR original, copy;
1738 struct displaced_step_closure *closure;
1739 struct displaced_step_inferior_state *displaced;
1742 /* We should never reach this function if the architecture does not
1743 support displaced stepping. */
1744 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1746 /* Nor if the thread isn't meant to step over a breakpoint. */
1747 gdb_assert (tp->control.trap_expected);
1749 /* Disable range stepping while executing in the scratch pad. We
1750 want a single-step even if executing the displaced instruction in
1751 the scratch buffer lands within the stepping range (e.g., a
1753 tp->control.may_range_step = 0;
1755 /* We have to displaced step one thread at a time, as we only have
1756 access to a single scratch space per inferior. */
1758 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1760 if (!ptid_equal (displaced->step_ptid, null_ptid))
1762 /* Already waiting for a displaced step to finish. Defer this
1763 request and place in queue. */
1765 if (debug_displaced)
1766 fprintf_unfiltered (gdb_stdlog,
1767 "displaced: deferring step of %s\n",
1768 target_pid_to_str (ptid));
1770 thread_step_over_chain_enqueue (tp);
1775 if (debug_displaced)
1776 fprintf_unfiltered (gdb_stdlog,
1777 "displaced: stepping %s now\n",
1778 target_pid_to_str (ptid));
1781 displaced_step_clear (displaced);
1783 old_cleanups = save_inferior_ptid ();
1784 inferior_ptid = ptid;
1786 original = regcache_read_pc (regcache);
1788 copy = gdbarch_displaced_step_location (gdbarch);
1789 len = gdbarch_max_insn_length (gdbarch);
1791 /* Save the original contents of the copy area. */
1792 displaced->step_saved_copy = xmalloc (len);
1793 ignore_cleanups = make_cleanup (free_current_contents,
1794 &displaced->step_saved_copy);
1795 status = target_read_memory (copy, displaced->step_saved_copy, len);
1797 throw_error (MEMORY_ERROR,
1798 _("Error accessing memory address %s (%s) for "
1799 "displaced-stepping scratch space."),
1800 paddress (gdbarch, copy), safe_strerror (status));
1801 if (debug_displaced)
1803 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1804 paddress (gdbarch, copy));
1805 displaced_step_dump_bytes (gdb_stdlog,
1806 displaced->step_saved_copy,
1810 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1811 original, copy, regcache);
1812 if (closure == NULL)
1814 /* The architecture doesn't know how or want to displaced step
1815 this instruction or instruction sequence. Fallback to
1816 stepping over the breakpoint in-line. */
1817 do_cleanups (old_cleanups);
1821 /* Save the information we need to fix things up if the step
1823 displaced->step_ptid = ptid;
1824 displaced->step_gdbarch = gdbarch;
1825 displaced->step_closure = closure;
1826 displaced->step_original = original;
1827 displaced->step_copy = copy;
1829 make_cleanup (displaced_step_clear_cleanup, displaced);
1831 /* Resume execution at the copy. */
1832 regcache_write_pc (regcache, copy);
1834 discard_cleanups (ignore_cleanups);
1836 do_cleanups (old_cleanups);
1838 if (debug_displaced)
1839 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1840 paddress (gdbarch, copy));
1845 /* Wrapper for displaced_step_prepare_throw that disabled further
1846 attempts at displaced stepping if we get a memory error. */
1849 displaced_step_prepare (ptid_t ptid)
1855 prepared = displaced_step_prepare_throw (ptid);
1857 CATCH (ex, RETURN_MASK_ERROR)
1859 struct displaced_step_inferior_state *displaced_state;
1861 if (ex.error != MEMORY_ERROR)
1862 throw_exception (ex);
1866 fprintf_unfiltered (gdb_stdlog,
1867 "infrun: disabling displaced stepping: %s\n",
1871 /* Be verbose if "set displaced-stepping" is "on", silent if
1873 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1875 warning (_("disabling displaced stepping: %s"),
1879 /* Disable further displaced stepping attempts. */
1881 = get_displaced_stepping_state (ptid_get_pid (ptid));
1882 displaced_state->failed_before = 1;
1890 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1891 const gdb_byte *myaddr, int len)
1893 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1895 inferior_ptid = ptid;
1896 write_memory (memaddr, myaddr, len);
1897 do_cleanups (ptid_cleanup);
1900 /* Restore the contents of the copy area for thread PTID. */
1903 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1906 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1908 write_memory_ptid (ptid, displaced->step_copy,
1909 displaced->step_saved_copy, len);
1910 if (debug_displaced)
1911 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1912 target_pid_to_str (ptid),
1913 paddress (displaced->step_gdbarch,
1914 displaced->step_copy));
1917 /* If we displaced stepped an instruction successfully, adjust
1918 registers and memory to yield the same effect the instruction would
1919 have had if we had executed it at its original address, and return
1920 1. If the instruction didn't complete, relocate the PC and return
1921 -1. If the thread wasn't displaced stepping, return 0. */
1924 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1926 struct cleanup *old_cleanups;
1927 struct displaced_step_inferior_state *displaced
1928 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1931 /* Was any thread of this process doing a displaced step? */
1932 if (displaced == NULL)
1935 /* Was this event for the pid we displaced? */
1936 if (ptid_equal (displaced->step_ptid, null_ptid)
1937 || ! ptid_equal (displaced->step_ptid, event_ptid))
1940 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1942 displaced_step_restore (displaced, displaced->step_ptid);
1944 /* Fixup may need to read memory/registers. Switch to the thread
1945 that we're fixing up. Also, target_stopped_by_watchpoint checks
1946 the current thread. */
1947 switch_to_thread (event_ptid);
1949 /* Did the instruction complete successfully? */
1950 if (signal == GDB_SIGNAL_TRAP
1951 && !(target_stopped_by_watchpoint ()
1952 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1953 || target_have_steppable_watchpoint)))
1955 /* Fix up the resulting state. */
1956 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1957 displaced->step_closure,
1958 displaced->step_original,
1959 displaced->step_copy,
1960 get_thread_regcache (displaced->step_ptid));
1965 /* Since the instruction didn't complete, all we can do is
1967 struct regcache *regcache = get_thread_regcache (event_ptid);
1968 CORE_ADDR pc = regcache_read_pc (regcache);
1970 pc = displaced->step_original + (pc - displaced->step_copy);
1971 regcache_write_pc (regcache, pc);
1975 do_cleanups (old_cleanups);
1977 displaced->step_ptid = null_ptid;
1982 /* Data to be passed around while handling an event. This data is
1983 discarded between events. */
1984 struct execution_control_state
1987 /* The thread that got the event, if this was a thread event; NULL
1989 struct thread_info *event_thread;
1991 struct target_waitstatus ws;
1992 int stop_func_filled_in;
1993 CORE_ADDR stop_func_start;
1994 CORE_ADDR stop_func_end;
1995 const char *stop_func_name;
1998 /* True if the event thread hit the single-step breakpoint of
1999 another thread. Thus the event doesn't cause a stop, the thread
2000 needs to be single-stepped past the single-step breakpoint before
2001 we can switch back to the original stepping thread. */
2002 int hit_singlestep_breakpoint;
2005 /* Clear ECS and set it to point at TP. */
2008 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2010 memset (ecs, 0, sizeof (*ecs));
2011 ecs->event_thread = tp;
2012 ecs->ptid = tp->ptid;
2015 static void keep_going_pass_signal (struct execution_control_state *ecs);
2016 static void prepare_to_wait (struct execution_control_state *ecs);
2017 static int keep_going_stepped_thread (struct thread_info *tp);
2018 static int thread_still_needs_step_over (struct thread_info *tp);
2019 static void stop_all_threads (void);
2021 /* Are there any pending step-over requests? If so, run all we can
2022 now and return true. Otherwise, return false. */
2025 start_step_over (void)
2027 struct thread_info *tp, *next;
2029 /* Don't start a new step-over if we already have an in-line
2030 step-over operation ongoing. */
2031 if (step_over_info_valid_p ())
2034 for (tp = step_over_queue_head; tp != NULL; tp = next)
2036 struct execution_control_state ecss;
2037 struct execution_control_state *ecs = &ecss;
2038 enum step_over_what step_what;
2039 int must_be_in_line;
2041 next = thread_step_over_chain_next (tp);
2043 /* If this inferior already has a displaced step in process,
2044 don't start a new one. */
2045 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2048 step_what = thread_still_needs_step_over (tp);
2049 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2050 || ((step_what & STEP_OVER_BREAKPOINT)
2051 && !use_displaced_stepping (tp)));
2053 /* We currently stop all threads of all processes to step-over
2054 in-line. If we need to start a new in-line step-over, let
2055 any pending displaced steps finish first. */
2056 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2059 thread_step_over_chain_remove (tp);
2061 if (step_over_queue_head == NULL)
2064 fprintf_unfiltered (gdb_stdlog,
2065 "infrun: step-over queue now empty\n");
2068 if (tp->control.trap_expected
2072 internal_error (__FILE__, __LINE__,
2073 "[%s] has inconsistent state: "
2074 "trap_expected=%d, resumed=%d, executing=%d\n",
2075 target_pid_to_str (tp->ptid),
2076 tp->control.trap_expected,
2082 fprintf_unfiltered (gdb_stdlog,
2083 "infrun: resuming [%s] for step-over\n",
2084 target_pid_to_str (tp->ptid));
2086 /* keep_going_pass_signal skips the step-over if the breakpoint
2087 is no longer inserted. In all-stop, we want to keep looking
2088 for a thread that needs a step-over instead of resuming TP,
2089 because we wouldn't be able to resume anything else until the
2090 target stops again. In non-stop, the resume always resumes
2091 only TP, so it's OK to let the thread resume freely. */
2092 if (!target_is_non_stop_p () && !step_what)
2095 switch_to_thread (tp->ptid);
2096 reset_ecs (ecs, tp);
2097 keep_going_pass_signal (ecs);
2099 if (!ecs->wait_some_more)
2100 error (_("Command aborted."));
2102 gdb_assert (tp->resumed);
2104 /* If we started a new in-line step-over, we're done. */
2105 if (step_over_info_valid_p ())
2107 gdb_assert (tp->control.trap_expected);
2111 if (!target_is_non_stop_p ())
2113 /* On all-stop, shouldn't have resumed unless we needed a
2115 gdb_assert (tp->control.trap_expected
2116 || tp->step_after_step_resume_breakpoint);
2118 /* With remote targets (at least), in all-stop, we can't
2119 issue any further remote commands until the program stops
2124 /* Either the thread no longer needed a step-over, or a new
2125 displaced stepping sequence started. Even in the latter
2126 case, continue looking. Maybe we can also start another
2127 displaced step on a thread of other process. */
2133 /* Update global variables holding ptids to hold NEW_PTID if they were
2134 holding OLD_PTID. */
2136 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2138 struct displaced_step_request *it;
2139 struct displaced_step_inferior_state *displaced;
2141 if (ptid_equal (inferior_ptid, old_ptid))
2142 inferior_ptid = new_ptid;
2144 for (displaced = displaced_step_inferior_states;
2146 displaced = displaced->next)
2148 if (ptid_equal (displaced->step_ptid, old_ptid))
2149 displaced->step_ptid = new_ptid;
2156 /* Things to clean up if we QUIT out of resume (). */
2158 resume_cleanups (void *ignore)
2160 if (!ptid_equal (inferior_ptid, null_ptid))
2161 delete_single_step_breakpoints (inferior_thread ());
2166 static const char schedlock_off[] = "off";
2167 static const char schedlock_on[] = "on";
2168 static const char schedlock_step[] = "step";
2169 static const char *const scheduler_enums[] = {
2175 static const char *scheduler_mode = schedlock_off;
2177 show_scheduler_mode (struct ui_file *file, int from_tty,
2178 struct cmd_list_element *c, const char *value)
2180 fprintf_filtered (file,
2181 _("Mode for locking scheduler "
2182 "during execution is \"%s\".\n"),
2187 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2189 if (!target_can_lock_scheduler)
2191 scheduler_mode = schedlock_off;
2192 error (_("Target '%s' cannot support this command."), target_shortname);
2196 /* True if execution commands resume all threads of all processes by
2197 default; otherwise, resume only threads of the current inferior
2199 int sched_multi = 0;
2201 /* Try to setup for software single stepping over the specified location.
2202 Return 1 if target_resume() should use hardware single step.
2204 GDBARCH the current gdbarch.
2205 PC the location to step over. */
2208 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2212 if (execution_direction == EXEC_FORWARD
2213 && gdbarch_software_single_step_p (gdbarch)
2214 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
2224 user_visible_resume_ptid (int step)
2230 /* With non-stop mode on, threads are always handled
2232 resume_ptid = inferior_ptid;
2234 else if ((scheduler_mode == schedlock_on)
2235 || (scheduler_mode == schedlock_step && step))
2237 /* User-settable 'scheduler' mode requires solo thread
2239 resume_ptid = inferior_ptid;
2241 else if (!sched_multi && target_supports_multi_process ())
2243 /* Resume all threads of the current process (and none of other
2245 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2249 /* Resume all threads of all processes. */
2250 resume_ptid = RESUME_ALL;
2256 /* Return a ptid representing the set of threads that we will resume,
2257 in the perspective of the target, assuming run control handling
2258 does not require leaving some threads stopped (e.g., stepping past
2259 breakpoint). USER_STEP indicates whether we're about to start the
2260 target for a stepping command. */
2263 internal_resume_ptid (int user_step)
2265 /* In non-stop, we always control threads individually. Note that
2266 the target may always work in non-stop mode even with "set
2267 non-stop off", in which case user_visible_resume_ptid could
2268 return a wildcard ptid. */
2269 if (target_is_non_stop_p ())
2270 return inferior_ptid;
2272 return user_visible_resume_ptid (user_step);
2275 /* Wrapper for target_resume, that handles infrun-specific
2279 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2281 struct thread_info *tp = inferior_thread ();
2283 /* Install inferior's terminal modes. */
2284 target_terminal_inferior ();
2286 /* Avoid confusing the next resume, if the next stop/resume
2287 happens to apply to another thread. */
2288 tp->suspend.stop_signal = GDB_SIGNAL_0;
2290 /* Advise target which signals may be handled silently.
2292 If we have removed breakpoints because we are stepping over one
2293 in-line (in any thread), we need to receive all signals to avoid
2294 accidentally skipping a breakpoint during execution of a signal
2297 Likewise if we're displaced stepping, otherwise a trap for a
2298 breakpoint in a signal handler might be confused with the
2299 displaced step finishing. We don't make the displaced_step_fixup
2300 step distinguish the cases instead, because:
2302 - a backtrace while stopped in the signal handler would show the
2303 scratch pad as frame older than the signal handler, instead of
2304 the real mainline code.
2306 - when the thread is later resumed, the signal handler would
2307 return to the scratch pad area, which would no longer be
2309 if (step_over_info_valid_p ()
2310 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2311 target_pass_signals (0, NULL);
2313 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2315 target_resume (resume_ptid, step, sig);
2318 /* Resume the inferior, but allow a QUIT. This is useful if the user
2319 wants to interrupt some lengthy single-stepping operation
2320 (for child processes, the SIGINT goes to the inferior, and so
2321 we get a SIGINT random_signal, but for remote debugging and perhaps
2322 other targets, that's not true).
2324 SIG is the signal to give the inferior (zero for none). */
2326 resume (enum gdb_signal sig)
2328 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2329 struct regcache *regcache = get_current_regcache ();
2330 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2331 struct thread_info *tp = inferior_thread ();
2332 CORE_ADDR pc = regcache_read_pc (regcache);
2333 struct address_space *aspace = get_regcache_aspace (regcache);
2335 /* This represents the user's step vs continue request. When
2336 deciding whether "set scheduler-locking step" applies, it's the
2337 user's intention that counts. */
2338 const int user_step = tp->control.stepping_command;
2339 /* This represents what we'll actually request the target to do.
2340 This can decay from a step to a continue, if e.g., we need to
2341 implement single-stepping with breakpoints (software
2345 gdb_assert (!thread_is_in_step_over_chain (tp));
2349 if (tp->suspend.waitstatus_pending_p)
2355 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2356 fprintf_unfiltered (gdb_stdlog,
2357 "infrun: resume: thread %s has pending wait status %s "
2358 "(currently_stepping=%d).\n",
2359 target_pid_to_str (tp->ptid), statstr,
2360 currently_stepping (tp));
2366 /* FIXME: What should we do if we are supposed to resume this
2367 thread with a signal? Maybe we should maintain a queue of
2368 pending signals to deliver. */
2369 if (sig != GDB_SIGNAL_0)
2371 warning (_("Couldn't deliver signal %s to %s."),
2372 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2375 tp->suspend.stop_signal = GDB_SIGNAL_0;
2376 discard_cleanups (old_cleanups);
2378 if (target_can_async_p ())
2383 tp->stepped_breakpoint = 0;
2385 /* Depends on stepped_breakpoint. */
2386 step = currently_stepping (tp);
2388 if (current_inferior ()->waiting_for_vfork_done)
2390 /* Don't try to single-step a vfork parent that is waiting for
2391 the child to get out of the shared memory region (by exec'ing
2392 or exiting). This is particularly important on software
2393 single-step archs, as the child process would trip on the
2394 software single step breakpoint inserted for the parent
2395 process. Since the parent will not actually execute any
2396 instruction until the child is out of the shared region (such
2397 are vfork's semantics), it is safe to simply continue it.
2398 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2399 the parent, and tell it to `keep_going', which automatically
2400 re-sets it stepping. */
2402 fprintf_unfiltered (gdb_stdlog,
2403 "infrun: resume : clear step\n");
2408 fprintf_unfiltered (gdb_stdlog,
2409 "infrun: resume (step=%d, signal=%s), "
2410 "trap_expected=%d, current thread [%s] at %s\n",
2411 step, gdb_signal_to_symbol_string (sig),
2412 tp->control.trap_expected,
2413 target_pid_to_str (inferior_ptid),
2414 paddress (gdbarch, pc));
2416 /* Normally, by the time we reach `resume', the breakpoints are either
2417 removed or inserted, as appropriate. The exception is if we're sitting
2418 at a permanent breakpoint; we need to step over it, but permanent
2419 breakpoints can't be removed. So we have to test for it here. */
2420 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2422 if (sig != GDB_SIGNAL_0)
2424 /* We have a signal to pass to the inferior. The resume
2425 may, or may not take us to the signal handler. If this
2426 is a step, we'll need to stop in the signal handler, if
2427 there's one, (if the target supports stepping into
2428 handlers), or in the next mainline instruction, if
2429 there's no handler. If this is a continue, we need to be
2430 sure to run the handler with all breakpoints inserted.
2431 In all cases, set a breakpoint at the current address
2432 (where the handler returns to), and once that breakpoint
2433 is hit, resume skipping the permanent breakpoint. If
2434 that breakpoint isn't hit, then we've stepped into the
2435 signal handler (or hit some other event). We'll delete
2436 the step-resume breakpoint then. */
2439 fprintf_unfiltered (gdb_stdlog,
2440 "infrun: resume: skipping permanent breakpoint, "
2441 "deliver signal first\n");
2443 clear_step_over_info ();
2444 tp->control.trap_expected = 0;
2446 if (tp->control.step_resume_breakpoint == NULL)
2448 /* Set a "high-priority" step-resume, as we don't want
2449 user breakpoints at PC to trigger (again) when this
2451 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2452 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2454 tp->step_after_step_resume_breakpoint = step;
2457 insert_breakpoints ();
2461 /* There's no signal to pass, we can go ahead and skip the
2462 permanent breakpoint manually. */
2464 fprintf_unfiltered (gdb_stdlog,
2465 "infrun: resume: skipping permanent breakpoint\n");
2466 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2467 /* Update pc to reflect the new address from which we will
2468 execute instructions. */
2469 pc = regcache_read_pc (regcache);
2473 /* We've already advanced the PC, so the stepping part
2474 is done. Now we need to arrange for a trap to be
2475 reported to handle_inferior_event. Set a breakpoint
2476 at the current PC, and run to it. Don't update
2477 prev_pc, because if we end in
2478 switch_back_to_stepped_thread, we want the "expected
2479 thread advanced also" branch to be taken. IOW, we
2480 don't want this thread to step further from PC
2482 gdb_assert (!step_over_info_valid_p ());
2483 insert_single_step_breakpoint (gdbarch, aspace, pc);
2484 insert_breakpoints ();
2486 resume_ptid = internal_resume_ptid (user_step);
2487 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2488 discard_cleanups (old_cleanups);
2495 /* If we have a breakpoint to step over, make sure to do a single
2496 step only. Same if we have software watchpoints. */
2497 if (tp->control.trap_expected || bpstat_should_step ())
2498 tp->control.may_range_step = 0;
2500 /* If enabled, step over breakpoints by executing a copy of the
2501 instruction at a different address.
2503 We can't use displaced stepping when we have a signal to deliver;
2504 the comments for displaced_step_prepare explain why. The
2505 comments in the handle_inferior event for dealing with 'random
2506 signals' explain what we do instead.
2508 We can't use displaced stepping when we are waiting for vfork_done
2509 event, displaced stepping breaks the vfork child similarly as single
2510 step software breakpoint. */
2511 if (tp->control.trap_expected
2512 && use_displaced_stepping (tp)
2513 && !step_over_info_valid_p ()
2514 && sig == GDB_SIGNAL_0
2515 && !current_inferior ()->waiting_for_vfork_done)
2517 int prepared = displaced_step_prepare (inferior_ptid);
2522 fprintf_unfiltered (gdb_stdlog,
2523 "Got placed in step-over queue\n");
2525 tp->control.trap_expected = 0;
2526 discard_cleanups (old_cleanups);
2529 else if (prepared < 0)
2531 /* Fallback to stepping over the breakpoint in-line. */
2533 if (target_is_non_stop_p ())
2534 stop_all_threads ();
2536 set_step_over_info (get_regcache_aspace (regcache),
2537 regcache_read_pc (regcache), 0);
2539 step = maybe_software_singlestep (gdbarch, pc);
2541 insert_breakpoints ();
2543 else if (prepared > 0)
2545 struct displaced_step_inferior_state *displaced;
2547 /* Update pc to reflect the new address from which we will
2548 execute instructions due to displaced stepping. */
2549 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2551 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2552 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2553 displaced->step_closure);
2557 /* Do we need to do it the hard way, w/temp breakpoints? */
2559 step = maybe_software_singlestep (gdbarch, pc);
2561 /* Currently, our software single-step implementation leads to different
2562 results than hardware single-stepping in one situation: when stepping
2563 into delivering a signal which has an associated signal handler,
2564 hardware single-step will stop at the first instruction of the handler,
2565 while software single-step will simply skip execution of the handler.
2567 For now, this difference in behavior is accepted since there is no
2568 easy way to actually implement single-stepping into a signal handler
2569 without kernel support.
2571 However, there is one scenario where this difference leads to follow-on
2572 problems: if we're stepping off a breakpoint by removing all breakpoints
2573 and then single-stepping. In this case, the software single-step
2574 behavior means that even if there is a *breakpoint* in the signal
2575 handler, GDB still would not stop.
2577 Fortunately, we can at least fix this particular issue. We detect
2578 here the case where we are about to deliver a signal while software
2579 single-stepping with breakpoints removed. In this situation, we
2580 revert the decisions to remove all breakpoints and insert single-
2581 step breakpoints, and instead we install a step-resume breakpoint
2582 at the current address, deliver the signal without stepping, and
2583 once we arrive back at the step-resume breakpoint, actually step
2584 over the breakpoint we originally wanted to step over. */
2585 if (thread_has_single_step_breakpoints_set (tp)
2586 && sig != GDB_SIGNAL_0
2587 && step_over_info_valid_p ())
2589 /* If we have nested signals or a pending signal is delivered
2590 immediately after a handler returns, might might already have
2591 a step-resume breakpoint set on the earlier handler. We cannot
2592 set another step-resume breakpoint; just continue on until the
2593 original breakpoint is hit. */
2594 if (tp->control.step_resume_breakpoint == NULL)
2596 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2597 tp->step_after_step_resume_breakpoint = 1;
2600 delete_single_step_breakpoints (tp);
2602 clear_step_over_info ();
2603 tp->control.trap_expected = 0;
2605 insert_breakpoints ();
2608 /* If STEP is set, it's a request to use hardware stepping
2609 facilities. But in that case, we should never
2610 use singlestep breakpoint. */
2611 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2613 /* Decide the set of threads to ask the target to resume. */
2614 if ((step || thread_has_single_step_breakpoints_set (tp))
2615 && tp->control.trap_expected)
2617 /* We're allowing a thread to run past a breakpoint it has
2618 hit, by single-stepping the thread with the breakpoint
2619 removed. In which case, we need to single-step only this
2620 thread, and keep others stopped, as they can miss this
2621 breakpoint if allowed to run. */
2622 resume_ptid = inferior_ptid;
2625 resume_ptid = internal_resume_ptid (user_step);
2627 if (execution_direction != EXEC_REVERSE
2628 && step && breakpoint_inserted_here_p (aspace, pc))
2630 /* There are two cases where we currently need to step a
2631 breakpoint instruction when we have a signal to deliver:
2633 - See handle_signal_stop where we handle random signals that
2634 could take out us out of the stepping range. Normally, in
2635 that case we end up continuing (instead of stepping) over the
2636 signal handler with a breakpoint at PC, but there are cases
2637 where we should _always_ single-step, even if we have a
2638 step-resume breakpoint, like when a software watchpoint is
2639 set. Assuming single-stepping and delivering a signal at the
2640 same time would takes us to the signal handler, then we could
2641 have removed the breakpoint at PC to step over it. However,
2642 some hardware step targets (like e.g., Mac OS) can't step
2643 into signal handlers, and for those, we need to leave the
2644 breakpoint at PC inserted, as otherwise if the handler
2645 recurses and executes PC again, it'll miss the breakpoint.
2646 So we leave the breakpoint inserted anyway, but we need to
2647 record that we tried to step a breakpoint instruction, so
2648 that adjust_pc_after_break doesn't end up confused.
2650 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2651 in one thread after another thread that was stepping had been
2652 momentarily paused for a step-over. When we re-resume the
2653 stepping thread, it may be resumed from that address with a
2654 breakpoint that hasn't trapped yet. Seen with
2655 gdb.threads/non-stop-fair-events.exp, on targets that don't
2656 do displaced stepping. */
2659 fprintf_unfiltered (gdb_stdlog,
2660 "infrun: resume: [%s] stepped breakpoint\n",
2661 target_pid_to_str (tp->ptid));
2663 tp->stepped_breakpoint = 1;
2665 /* Most targets can step a breakpoint instruction, thus
2666 executing it normally. But if this one cannot, just
2667 continue and we will hit it anyway. */
2668 if (gdbarch_cannot_step_breakpoint (gdbarch))
2673 && tp->control.trap_expected
2674 && use_displaced_stepping (tp)
2675 && !step_over_info_valid_p ())
2677 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2678 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2679 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2682 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2683 paddress (resume_gdbarch, actual_pc));
2684 read_memory (actual_pc, buf, sizeof (buf));
2685 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2688 if (tp->control.may_range_step)
2690 /* If we're resuming a thread with the PC out of the step
2691 range, then we're doing some nested/finer run control
2692 operation, like stepping the thread out of the dynamic
2693 linker or the displaced stepping scratch pad. We
2694 shouldn't have allowed a range step then. */
2695 gdb_assert (pc_in_thread_step_range (pc, tp));
2698 do_target_resume (resume_ptid, step, sig);
2700 discard_cleanups (old_cleanups);
2705 /* Clear out all variables saying what to do when inferior is continued.
2706 First do this, then set the ones you want, then call `proceed'. */
2709 clear_proceed_status_thread (struct thread_info *tp)
2712 fprintf_unfiltered (gdb_stdlog,
2713 "infrun: clear_proceed_status_thread (%s)\n",
2714 target_pid_to_str (tp->ptid));
2716 /* If we're starting a new sequence, then the previous finished
2717 single-step is no longer relevant. */
2718 if (tp->suspend.waitstatus_pending_p)
2720 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2723 fprintf_unfiltered (gdb_stdlog,
2724 "infrun: clear_proceed_status: pending "
2725 "event of %s was a finished step. "
2727 target_pid_to_str (tp->ptid));
2729 tp->suspend.waitstatus_pending_p = 0;
2730 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2732 else if (debug_infrun)
2736 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2737 fprintf_unfiltered (gdb_stdlog,
2738 "infrun: clear_proceed_status_thread: thread %s "
2739 "has pending wait status %s "
2740 "(currently_stepping=%d).\n",
2741 target_pid_to_str (tp->ptid), statstr,
2742 currently_stepping (tp));
2747 /* If this signal should not be seen by program, give it zero.
2748 Used for debugging signals. */
2749 if (!signal_pass_state (tp->suspend.stop_signal))
2750 tp->suspend.stop_signal = GDB_SIGNAL_0;
2752 thread_fsm_delete (tp->thread_fsm);
2753 tp->thread_fsm = NULL;
2755 tp->control.trap_expected = 0;
2756 tp->control.step_range_start = 0;
2757 tp->control.step_range_end = 0;
2758 tp->control.may_range_step = 0;
2759 tp->control.step_frame_id = null_frame_id;
2760 tp->control.step_stack_frame_id = null_frame_id;
2761 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2762 tp->control.step_start_function = NULL;
2763 tp->stop_requested = 0;
2765 tp->control.stop_step = 0;
2767 tp->control.proceed_to_finish = 0;
2769 tp->control.command_interp = NULL;
2770 tp->control.stepping_command = 0;
2772 /* Discard any remaining commands or status from previous stop. */
2773 bpstat_clear (&tp->control.stop_bpstat);
2777 clear_proceed_status (int step)
2781 struct thread_info *tp;
2784 resume_ptid = user_visible_resume_ptid (step);
2786 /* In all-stop mode, delete the per-thread status of all threads
2787 we're about to resume, implicitly and explicitly. */
2788 ALL_NON_EXITED_THREADS (tp)
2790 if (!ptid_match (tp->ptid, resume_ptid))
2792 clear_proceed_status_thread (tp);
2796 if (!ptid_equal (inferior_ptid, null_ptid))
2798 struct inferior *inferior;
2802 /* If in non-stop mode, only delete the per-thread status of
2803 the current thread. */
2804 clear_proceed_status_thread (inferior_thread ());
2807 inferior = current_inferior ();
2808 inferior->control.stop_soon = NO_STOP_QUIETLY;
2811 stop_after_trap = 0;
2813 observer_notify_about_to_proceed ();
2816 /* Returns true if TP is still stopped at a breakpoint that needs
2817 stepping-over in order to make progress. If the breakpoint is gone
2818 meanwhile, we can skip the whole step-over dance. */
2821 thread_still_needs_step_over_bp (struct thread_info *tp)
2823 if (tp->stepping_over_breakpoint)
2825 struct regcache *regcache = get_thread_regcache (tp->ptid);
2827 if (breakpoint_here_p (get_regcache_aspace (regcache),
2828 regcache_read_pc (regcache))
2829 == ordinary_breakpoint_here)
2832 tp->stepping_over_breakpoint = 0;
2838 /* Check whether thread TP still needs to start a step-over in order
2839 to make progress when resumed. Returns an bitwise or of enum
2840 step_over_what bits, indicating what needs to be stepped over. */
2843 thread_still_needs_step_over (struct thread_info *tp)
2845 struct inferior *inf = find_inferior_ptid (tp->ptid);
2848 if (thread_still_needs_step_over_bp (tp))
2849 what |= STEP_OVER_BREAKPOINT;
2851 if (tp->stepping_over_watchpoint
2852 && !target_have_steppable_watchpoint)
2853 what |= STEP_OVER_WATCHPOINT;
2858 /* Returns true if scheduler locking applies. STEP indicates whether
2859 we're about to do a step/next-like command to a thread. */
2862 schedlock_applies (struct thread_info *tp)
2864 return (scheduler_mode == schedlock_on
2865 || (scheduler_mode == schedlock_step
2866 && tp->control.stepping_command));
2869 /* Basic routine for continuing the program in various fashions.
2871 ADDR is the address to resume at, or -1 for resume where stopped.
2872 SIGGNAL is the signal to give it, or 0 for none,
2873 or -1 for act according to how it stopped.
2874 STEP is nonzero if should trap after one instruction.
2875 -1 means return after that and print nothing.
2876 You should probably set various step_... variables
2877 before calling here, if you are stepping.
2879 You should call clear_proceed_status before calling proceed. */
2882 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2884 struct regcache *regcache;
2885 struct gdbarch *gdbarch;
2886 struct thread_info *tp;
2888 struct address_space *aspace;
2890 struct execution_control_state ecss;
2891 struct execution_control_state *ecs = &ecss;
2892 struct cleanup *old_chain;
2895 /* If we're stopped at a fork/vfork, follow the branch set by the
2896 "set follow-fork-mode" command; otherwise, we'll just proceed
2897 resuming the current thread. */
2898 if (!follow_fork ())
2900 /* The target for some reason decided not to resume. */
2902 if (target_can_async_p ())
2903 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2907 /* We'll update this if & when we switch to a new thread. */
2908 previous_inferior_ptid = inferior_ptid;
2910 regcache = get_current_regcache ();
2911 gdbarch = get_regcache_arch (regcache);
2912 aspace = get_regcache_aspace (regcache);
2913 pc = regcache_read_pc (regcache);
2914 tp = inferior_thread ();
2916 /* Fill in with reasonable starting values. */
2917 init_thread_stepping_state (tp);
2919 gdb_assert (!thread_is_in_step_over_chain (tp));
2921 if (addr == (CORE_ADDR) -1)
2924 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2925 && execution_direction != EXEC_REVERSE)
2926 /* There is a breakpoint at the address we will resume at,
2927 step one instruction before inserting breakpoints so that
2928 we do not stop right away (and report a second hit at this
2931 Note, we don't do this in reverse, because we won't
2932 actually be executing the breakpoint insn anyway.
2933 We'll be (un-)executing the previous instruction. */
2934 tp->stepping_over_breakpoint = 1;
2935 else if (gdbarch_single_step_through_delay_p (gdbarch)
2936 && gdbarch_single_step_through_delay (gdbarch,
2937 get_current_frame ()))
2938 /* We stepped onto an instruction that needs to be stepped
2939 again before re-inserting the breakpoint, do so. */
2940 tp->stepping_over_breakpoint = 1;
2944 regcache_write_pc (regcache, addr);
2947 if (siggnal != GDB_SIGNAL_DEFAULT)
2948 tp->suspend.stop_signal = siggnal;
2950 /* Record the interpreter that issued the execution command that
2951 caused this thread to resume. If the top level interpreter is
2952 MI/async, and the execution command was a CLI command
2953 (next/step/etc.), we'll want to print stop event output to the MI
2954 console channel (the stepped-to line, etc.), as if the user
2955 entered the execution command on a real GDB console. */
2956 tp->control.command_interp = command_interp ();
2958 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
2960 /* If an exception is thrown from this point on, make sure to
2961 propagate GDB's knowledge of the executing state to the
2962 frontend/user running state. */
2963 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
2965 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2966 threads (e.g., we might need to set threads stepping over
2967 breakpoints first), from the user/frontend's point of view, all
2968 threads in RESUME_PTID are now running. Unless we're calling an
2969 inferior function, as in that case we pretend the inferior
2970 doesn't run at all. */
2971 if (!tp->control.in_infcall)
2972 set_running (resume_ptid, 1);
2975 fprintf_unfiltered (gdb_stdlog,
2976 "infrun: proceed (addr=%s, signal=%s)\n",
2977 paddress (gdbarch, addr),
2978 gdb_signal_to_symbol_string (siggnal));
2980 annotate_starting ();
2982 /* Make sure that output from GDB appears before output from the
2984 gdb_flush (gdb_stdout);
2986 /* In a multi-threaded task we may select another thread and
2987 then continue or step.
2989 But if a thread that we're resuming had stopped at a breakpoint,
2990 it will immediately cause another breakpoint stop without any
2991 execution (i.e. it will report a breakpoint hit incorrectly). So
2992 we must step over it first.
2994 Look for threads other than the current (TP) that reported a
2995 breakpoint hit and haven't been resumed yet since. */
2997 /* If scheduler locking applies, we can avoid iterating over all
2999 if (!non_stop && !schedlock_applies (tp))
3001 struct thread_info *current = tp;
3003 ALL_NON_EXITED_THREADS (tp)
3005 /* Ignore the current thread here. It's handled
3010 /* Ignore threads of processes we're not resuming. */
3011 if (!ptid_match (tp->ptid, resume_ptid))
3014 if (!thread_still_needs_step_over (tp))
3017 gdb_assert (!thread_is_in_step_over_chain (tp));
3020 fprintf_unfiltered (gdb_stdlog,
3021 "infrun: need to step-over [%s] first\n",
3022 target_pid_to_str (tp->ptid));
3024 thread_step_over_chain_enqueue (tp);
3030 /* Enqueue the current thread last, so that we move all other
3031 threads over their breakpoints first. */
3032 if (tp->stepping_over_breakpoint)
3033 thread_step_over_chain_enqueue (tp);
3035 /* If the thread isn't started, we'll still need to set its prev_pc,
3036 so that switch_back_to_stepped_thread knows the thread hasn't
3037 advanced. Must do this before resuming any thread, as in
3038 all-stop/remote, once we resume we can't send any other packet
3039 until the target stops again. */
3040 tp->prev_pc = regcache_read_pc (regcache);
3042 started = start_step_over ();
3044 if (step_over_info_valid_p ())
3046 /* Either this thread started a new in-line step over, or some
3047 other thread was already doing one. In either case, don't
3048 resume anything else until the step-over is finished. */
3050 else if (started && !target_is_non_stop_p ())
3052 /* A new displaced stepping sequence was started. In all-stop,
3053 we can't talk to the target anymore until it next stops. */
3055 else if (!non_stop && target_is_non_stop_p ())
3057 /* In all-stop, but the target is always in non-stop mode.
3058 Start all other threads that are implicitly resumed too. */
3059 ALL_NON_EXITED_THREADS (tp)
3061 /* Ignore threads of processes we're not resuming. */
3062 if (!ptid_match (tp->ptid, resume_ptid))
3068 fprintf_unfiltered (gdb_stdlog,
3069 "infrun: proceed: [%s] resumed\n",
3070 target_pid_to_str (tp->ptid));
3071 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3075 if (thread_is_in_step_over_chain (tp))
3078 fprintf_unfiltered (gdb_stdlog,
3079 "infrun: proceed: [%s] needs step-over\n",
3080 target_pid_to_str (tp->ptid));
3085 fprintf_unfiltered (gdb_stdlog,
3086 "infrun: proceed: resuming %s\n",
3087 target_pid_to_str (tp->ptid));
3089 reset_ecs (ecs, tp);
3090 switch_to_thread (tp->ptid);
3091 keep_going_pass_signal (ecs);
3092 if (!ecs->wait_some_more)
3093 error (_("Command aborted."));
3096 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3098 /* The thread wasn't started, and isn't queued, run it now. */
3099 reset_ecs (ecs, tp);
3100 switch_to_thread (tp->ptid);
3101 keep_going_pass_signal (ecs);
3102 if (!ecs->wait_some_more)
3103 error (_("Command aborted."));
3106 discard_cleanups (old_chain);
3108 /* Tell the event loop to wait for it to stop. If the target
3109 supports asynchronous execution, it'll do this from within
3111 if (!target_can_async_p ())
3112 mark_async_event_handler (infrun_async_inferior_event_token);
3116 /* Start remote-debugging of a machine over a serial link. */
3119 start_remote (int from_tty)
3121 struct inferior *inferior;
3123 inferior = current_inferior ();
3124 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3126 /* Always go on waiting for the target, regardless of the mode. */
3127 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3128 indicate to wait_for_inferior that a target should timeout if
3129 nothing is returned (instead of just blocking). Because of this,
3130 targets expecting an immediate response need to, internally, set
3131 things up so that the target_wait() is forced to eventually
3133 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3134 differentiate to its caller what the state of the target is after
3135 the initial open has been performed. Here we're assuming that
3136 the target has stopped. It should be possible to eventually have
3137 target_open() return to the caller an indication that the target
3138 is currently running and GDB state should be set to the same as
3139 for an async run. */
3140 wait_for_inferior ();
3142 /* Now that the inferior has stopped, do any bookkeeping like
3143 loading shared libraries. We want to do this before normal_stop,
3144 so that the displayed frame is up to date. */
3145 post_create_inferior (¤t_target, from_tty);
3150 /* Initialize static vars when a new inferior begins. */
3153 init_wait_for_inferior (void)
3155 /* These are meaningless until the first time through wait_for_inferior. */
3157 breakpoint_init_inferior (inf_starting);
3159 clear_proceed_status (0);
3161 target_last_wait_ptid = minus_one_ptid;
3163 previous_inferior_ptid = inferior_ptid;
3165 /* Discard any skipped inlined frames. */
3166 clear_inline_frame_state (minus_one_ptid);
3171 static void handle_inferior_event (struct execution_control_state *ecs);
3173 static void handle_step_into_function (struct gdbarch *gdbarch,
3174 struct execution_control_state *ecs);
3175 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3176 struct execution_control_state *ecs);
3177 static void handle_signal_stop (struct execution_control_state *ecs);
3178 static void check_exception_resume (struct execution_control_state *,
3179 struct frame_info *);
3181 static void end_stepping_range (struct execution_control_state *ecs);
3182 static void stop_waiting (struct execution_control_state *ecs);
3183 static void keep_going (struct execution_control_state *ecs);
3184 static void process_event_stop_test (struct execution_control_state *ecs);
3185 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3187 /* Callback for iterate over threads. If the thread is stopped, but
3188 the user/frontend doesn't know about that yet, go through
3189 normal_stop, as if the thread had just stopped now. ARG points at
3190 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
3191 ptid_is_pid(PTID) is true, applies to all threads of the process
3192 pointed at by PTID. Otherwise, apply only to the thread pointed by
3196 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
3198 ptid_t ptid = * (ptid_t *) arg;
3200 if ((ptid_equal (info->ptid, ptid)
3201 || ptid_equal (minus_one_ptid, ptid)
3202 || (ptid_is_pid (ptid)
3203 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
3204 && is_running (info->ptid)
3205 && !is_executing (info->ptid))
3207 struct cleanup *old_chain;
3208 struct execution_control_state ecss;
3209 struct execution_control_state *ecs = &ecss;
3211 memset (ecs, 0, sizeof (*ecs));
3213 old_chain = make_cleanup_restore_current_thread ();
3215 overlay_cache_invalid = 1;
3216 /* Flush target cache before starting to handle each event.
3217 Target was running and cache could be stale. This is just a
3218 heuristic. Running threads may modify target memory, but we
3219 don't get any event. */
3220 target_dcache_invalidate ();
3222 /* Go through handle_inferior_event/normal_stop, so we always
3223 have consistent output as if the stop event had been
3225 ecs->ptid = info->ptid;
3226 ecs->event_thread = info;
3227 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
3228 ecs->ws.value.sig = GDB_SIGNAL_0;
3230 handle_inferior_event (ecs);
3232 if (!ecs->wait_some_more)
3234 /* Cancel any running execution command. */
3235 thread_cancel_execution_command (info);
3240 do_cleanups (old_chain);
3246 /* This function is attached as a "thread_stop_requested" observer.
3247 Cleanup local state that assumed the PTID was to be resumed, and
3248 report the stop to the frontend. */
3251 infrun_thread_stop_requested (ptid_t ptid)
3253 struct thread_info *tp;
3255 /* PTID was requested to stop. Remove matching threads from the
3256 step-over queue, so we don't try to resume them
3258 ALL_NON_EXITED_THREADS (tp)
3259 if (ptid_match (tp->ptid, ptid))
3261 if (thread_is_in_step_over_chain (tp))
3262 thread_step_over_chain_remove (tp);
3265 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
3269 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3271 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3272 nullify_last_target_wait_ptid ();
3275 /* Delete the step resume, single-step and longjmp/exception resume
3276 breakpoints of TP. */
3279 delete_thread_infrun_breakpoints (struct thread_info *tp)
3281 delete_step_resume_breakpoint (tp);
3282 delete_exception_resume_breakpoint (tp);
3283 delete_single_step_breakpoints (tp);
3286 /* If the target still has execution, call FUNC for each thread that
3287 just stopped. In all-stop, that's all the non-exited threads; in
3288 non-stop, that's the current thread, only. */
3290 typedef void (*for_each_just_stopped_thread_callback_func)
3291 (struct thread_info *tp);
3294 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3296 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3299 if (target_is_non_stop_p ())
3301 /* If in non-stop mode, only the current thread stopped. */
3302 func (inferior_thread ());
3306 struct thread_info *tp;
3308 /* In all-stop mode, all threads have stopped. */
3309 ALL_NON_EXITED_THREADS (tp)
3316 /* Delete the step resume and longjmp/exception resume breakpoints of
3317 the threads that just stopped. */
3320 delete_just_stopped_threads_infrun_breakpoints (void)
3322 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3325 /* Delete the single-step breakpoints of the threads that just
3329 delete_just_stopped_threads_single_step_breakpoints (void)
3331 for_each_just_stopped_thread (delete_single_step_breakpoints);
3334 /* A cleanup wrapper. */
3337 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3339 delete_just_stopped_threads_infrun_breakpoints ();
3345 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3346 const struct target_waitstatus *ws)
3348 char *status_string = target_waitstatus_to_string (ws);
3349 struct ui_file *tmp_stream = mem_fileopen ();
3352 /* The text is split over several lines because it was getting too long.
3353 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3354 output as a unit; we want only one timestamp printed if debug_timestamp
3357 fprintf_unfiltered (tmp_stream,
3358 "infrun: target_wait (%d.%ld.%ld",
3359 ptid_get_pid (waiton_ptid),
3360 ptid_get_lwp (waiton_ptid),
3361 ptid_get_tid (waiton_ptid));
3362 if (ptid_get_pid (waiton_ptid) != -1)
3363 fprintf_unfiltered (tmp_stream,
3364 " [%s]", target_pid_to_str (waiton_ptid));
3365 fprintf_unfiltered (tmp_stream, ", status) =\n");
3366 fprintf_unfiltered (tmp_stream,
3367 "infrun: %d.%ld.%ld [%s],\n",
3368 ptid_get_pid (result_ptid),
3369 ptid_get_lwp (result_ptid),
3370 ptid_get_tid (result_ptid),
3371 target_pid_to_str (result_ptid));
3372 fprintf_unfiltered (tmp_stream,
3376 text = ui_file_xstrdup (tmp_stream, NULL);
3378 /* This uses %s in part to handle %'s in the text, but also to avoid
3379 a gcc error: the format attribute requires a string literal. */
3380 fprintf_unfiltered (gdb_stdlog, "%s", text);
3382 xfree (status_string);
3384 ui_file_delete (tmp_stream);
3387 /* Select a thread at random, out of those which are resumed and have
3390 static struct thread_info *
3391 random_pending_event_thread (ptid_t waiton_ptid)
3393 struct thread_info *event_tp;
3395 int random_selector;
3397 /* First see how many events we have. Count only resumed threads
3398 that have an event pending. */
3399 ALL_NON_EXITED_THREADS (event_tp)
3400 if (ptid_match (event_tp->ptid, waiton_ptid)
3401 && event_tp->resumed
3402 && event_tp->suspend.waitstatus_pending_p)
3405 if (num_events == 0)
3408 /* Now randomly pick a thread out of those that have had events. */
3409 random_selector = (int)
3410 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3412 if (debug_infrun && num_events > 1)
3413 fprintf_unfiltered (gdb_stdlog,
3414 "infrun: Found %d events, selecting #%d\n",
3415 num_events, random_selector);
3417 /* Select the Nth thread that has had an event. */
3418 ALL_NON_EXITED_THREADS (event_tp)
3419 if (ptid_match (event_tp->ptid, waiton_ptid)
3420 && event_tp->resumed
3421 && event_tp->suspend.waitstatus_pending_p)
3422 if (random_selector-- == 0)
3428 /* Wrapper for target_wait that first checks whether threads have
3429 pending statuses to report before actually asking the target for
3433 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3436 struct thread_info *tp;
3438 /* First check if there is a resumed thread with a wait status
3440 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3442 tp = random_pending_event_thread (ptid);
3447 fprintf_unfiltered (gdb_stdlog,
3448 "infrun: Waiting for specific thread %s.\n",
3449 target_pid_to_str (ptid));
3451 /* We have a specific thread to check. */
3452 tp = find_thread_ptid (ptid);
3453 gdb_assert (tp != NULL);
3454 if (!tp->suspend.waitstatus_pending_p)
3459 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3460 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3462 struct regcache *regcache = get_thread_regcache (tp->ptid);
3463 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3467 pc = regcache_read_pc (regcache);
3469 if (pc != tp->suspend.stop_pc)
3472 fprintf_unfiltered (gdb_stdlog,
3473 "infrun: PC of %s changed. was=%s, now=%s\n",
3474 target_pid_to_str (tp->ptid),
3475 paddress (gdbarch, tp->prev_pc),
3476 paddress (gdbarch, pc));
3479 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3482 fprintf_unfiltered (gdb_stdlog,
3483 "infrun: previous breakpoint of %s, at %s gone\n",
3484 target_pid_to_str (tp->ptid),
3485 paddress (gdbarch, pc));
3493 fprintf_unfiltered (gdb_stdlog,
3494 "infrun: pending event of %s cancelled.\n",
3495 target_pid_to_str (tp->ptid));
3497 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3498 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3508 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
3509 fprintf_unfiltered (gdb_stdlog,
3510 "infrun: Using pending wait status %s for %s.\n",
3512 target_pid_to_str (tp->ptid));
3516 /* Now that we've selected our final event LWP, un-adjust its PC
3517 if it was a software breakpoint (and the target doesn't
3518 always adjust the PC itself). */
3519 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3520 && !target_supports_stopped_by_sw_breakpoint ())
3522 struct regcache *regcache;
3523 struct gdbarch *gdbarch;
3526 regcache = get_thread_regcache (tp->ptid);
3527 gdbarch = get_regcache_arch (regcache);
3529 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3534 pc = regcache_read_pc (regcache);
3535 regcache_write_pc (regcache, pc + decr_pc);
3539 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3540 *status = tp->suspend.waitstatus;
3541 tp->suspend.waitstatus_pending_p = 0;
3543 /* Wake up the event loop again, until all pending events are
3545 if (target_is_async_p ())
3546 mark_async_event_handler (infrun_async_inferior_event_token);
3550 /* But if we don't find one, we'll have to wait. */
3552 if (deprecated_target_wait_hook)
3553 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3555 event_ptid = target_wait (ptid, status, options);
3560 /* Prepare and stabilize the inferior for detaching it. E.g.,
3561 detaching while a thread is displaced stepping is a recipe for
3562 crashing it, as nothing would readjust the PC out of the scratch
3566 prepare_for_detach (void)
3568 struct inferior *inf = current_inferior ();
3569 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3570 struct cleanup *old_chain_1;
3571 struct displaced_step_inferior_state *displaced;
3573 displaced = get_displaced_stepping_state (inf->pid);
3575 /* Is any thread of this process displaced stepping? If not,
3576 there's nothing else to do. */
3577 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3581 fprintf_unfiltered (gdb_stdlog,
3582 "displaced-stepping in-process while detaching");
3584 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3587 while (!ptid_equal (displaced->step_ptid, null_ptid))
3589 struct cleanup *old_chain_2;
3590 struct execution_control_state ecss;
3591 struct execution_control_state *ecs;
3594 memset (ecs, 0, sizeof (*ecs));
3596 overlay_cache_invalid = 1;
3597 /* Flush target cache before starting to handle each event.
3598 Target was running and cache could be stale. This is just a
3599 heuristic. Running threads may modify target memory, but we
3600 don't get any event. */
3601 target_dcache_invalidate ();
3603 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3606 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3608 /* If an error happens while handling the event, propagate GDB's
3609 knowledge of the executing state to the frontend/user running
3611 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3614 /* Now figure out what to do with the result of the result. */
3615 handle_inferior_event (ecs);
3617 /* No error, don't finish the state yet. */
3618 discard_cleanups (old_chain_2);
3620 /* Breakpoints and watchpoints are not installed on the target
3621 at this point, and signals are passed directly to the
3622 inferior, so this must mean the process is gone. */
3623 if (!ecs->wait_some_more)
3625 discard_cleanups (old_chain_1);
3626 error (_("Program exited while detaching"));
3630 discard_cleanups (old_chain_1);
3633 /* Wait for control to return from inferior to debugger.
3635 If inferior gets a signal, we may decide to start it up again
3636 instead of returning. That is why there is a loop in this function.
3637 When this function actually returns it means the inferior
3638 should be left stopped and GDB should read more commands. */
3641 wait_for_inferior (void)
3643 struct cleanup *old_cleanups;
3644 struct cleanup *thread_state_chain;
3648 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3651 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3654 /* If an error happens while handling the event, propagate GDB's
3655 knowledge of the executing state to the frontend/user running
3657 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3661 struct execution_control_state ecss;
3662 struct execution_control_state *ecs = &ecss;
3663 ptid_t waiton_ptid = minus_one_ptid;
3665 memset (ecs, 0, sizeof (*ecs));
3667 overlay_cache_invalid = 1;
3669 /* Flush target cache before starting to handle each event.
3670 Target was running and cache could be stale. This is just a
3671 heuristic. Running threads may modify target memory, but we
3672 don't get any event. */
3673 target_dcache_invalidate ();
3675 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3678 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3680 /* Now figure out what to do with the result of the result. */
3681 handle_inferior_event (ecs);
3683 if (!ecs->wait_some_more)
3687 /* No error, don't finish the state yet. */
3688 discard_cleanups (thread_state_chain);
3690 do_cleanups (old_cleanups);
3693 /* Cleanup that reinstalls the readline callback handler, if the
3694 target is running in the background. If while handling the target
3695 event something triggered a secondary prompt, like e.g., a
3696 pagination prompt, we'll have removed the callback handler (see
3697 gdb_readline_wrapper_line). Need to do this as we go back to the
3698 event loop, ready to process further input. Note this has no
3699 effect if the handler hasn't actually been removed, because calling
3700 rl_callback_handler_install resets the line buffer, thus losing
3704 reinstall_readline_callback_handler_cleanup (void *arg)
3706 if (!interpreter_async)
3708 /* We're not going back to the top level event loop yet. Don't
3709 install the readline callback, as it'd prep the terminal,
3710 readline-style (raw, noecho) (e.g., --batch). We'll install
3711 it the next time the prompt is displayed, when we're ready
3716 if (async_command_editing_p && !sync_execution)
3717 gdb_rl_callback_handler_reinstall ();
3720 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3721 that's just the event thread. In all-stop, that's all threads. */
3724 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3726 struct thread_info *thr = ecs->event_thread;
3728 if (thr != NULL && thr->thread_fsm != NULL)
3729 thread_fsm_clean_up (thr->thread_fsm);
3733 ALL_NON_EXITED_THREADS (thr)
3735 if (thr->thread_fsm == NULL)
3737 if (thr == ecs->event_thread)
3740 switch_to_thread (thr->ptid);
3741 thread_fsm_clean_up (thr->thread_fsm);
3744 if (ecs->event_thread != NULL)
3745 switch_to_thread (ecs->event_thread->ptid);
3749 /* Asynchronous version of wait_for_inferior. It is called by the
3750 event loop whenever a change of state is detected on the file
3751 descriptor corresponding to the target. It can be called more than
3752 once to complete a single execution command. In such cases we need
3753 to keep the state in a global variable ECSS. If it is the last time
3754 that this function is called for a single execution command, then
3755 report to the user that the inferior has stopped, and do the
3756 necessary cleanups. */
3759 fetch_inferior_event (void *client_data)
3761 struct execution_control_state ecss;
3762 struct execution_control_state *ecs = &ecss;
3763 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3764 struct cleanup *ts_old_chain;
3765 int was_sync = sync_execution;
3767 ptid_t waiton_ptid = minus_one_ptid;
3769 memset (ecs, 0, sizeof (*ecs));
3771 /* End up with readline processing input, if necessary. */
3772 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3774 /* We're handling a live event, so make sure we're doing live
3775 debugging. If we're looking at traceframes while the target is
3776 running, we're going to need to get back to that mode after
3777 handling the event. */
3780 make_cleanup_restore_current_traceframe ();
3781 set_current_traceframe (-1);
3785 /* In non-stop mode, the user/frontend should not notice a thread
3786 switch due to internal events. Make sure we reverse to the
3787 user selected thread and frame after handling the event and
3788 running any breakpoint commands. */
3789 make_cleanup_restore_current_thread ();
3791 overlay_cache_invalid = 1;
3792 /* Flush target cache before starting to handle each event. Target
3793 was running and cache could be stale. This is just a heuristic.
3794 Running threads may modify target memory, but we don't get any
3796 target_dcache_invalidate ();
3798 make_cleanup_restore_integer (&execution_direction);
3799 execution_direction = target_execution_direction ();
3801 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3802 target_can_async_p () ? TARGET_WNOHANG : 0);
3805 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3807 /* If an error happens while handling the event, propagate GDB's
3808 knowledge of the executing state to the frontend/user running
3810 if (!target_is_non_stop_p ())
3811 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3813 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3815 /* Get executed before make_cleanup_restore_current_thread above to apply
3816 still for the thread which has thrown the exception. */
3817 make_bpstat_clear_actions_cleanup ();
3819 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3821 /* Now figure out what to do with the result of the result. */
3822 handle_inferior_event (ecs);
3824 if (!ecs->wait_some_more)
3826 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3827 int should_stop = 1;
3828 struct thread_info *thr = ecs->event_thread;
3829 int should_notify_stop = 1;
3831 delete_just_stopped_threads_infrun_breakpoints ();
3835 struct thread_fsm *thread_fsm = thr->thread_fsm;
3837 if (thread_fsm != NULL)
3838 should_stop = thread_fsm_should_stop (thread_fsm);
3847 clean_up_just_stopped_threads_fsms (ecs);
3849 if (thr != NULL && thr->thread_fsm != NULL)
3852 = thread_fsm_should_notify_stop (thr->thread_fsm);
3855 if (should_notify_stop)
3857 /* We may not find an inferior if this was a process exit. */
3858 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3861 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3867 /* No error, don't finish the thread states yet. */
3868 discard_cleanups (ts_old_chain);
3870 /* Revert thread and frame. */
3871 do_cleanups (old_chain);
3873 /* If the inferior was in sync execution mode, and now isn't,
3874 restore the prompt (a synchronous execution command has finished,
3875 and we're ready for input). */
3876 if (interpreter_async && was_sync && !sync_execution)
3877 observer_notify_sync_execution_done ();
3881 && exec_done_display_p
3882 && (ptid_equal (inferior_ptid, null_ptid)
3883 || !is_running (inferior_ptid)))
3884 printf_unfiltered (_("completed.\n"));
3887 /* Record the frame and location we're currently stepping through. */
3889 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3891 struct thread_info *tp = inferior_thread ();
3893 tp->control.step_frame_id = get_frame_id (frame);
3894 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3896 tp->current_symtab = sal.symtab;
3897 tp->current_line = sal.line;
3900 /* Clear context switchable stepping state. */
3903 init_thread_stepping_state (struct thread_info *tss)
3905 tss->stepped_breakpoint = 0;
3906 tss->stepping_over_breakpoint = 0;
3907 tss->stepping_over_watchpoint = 0;
3908 tss->step_after_step_resume_breakpoint = 0;
3911 /* Set the cached copy of the last ptid/waitstatus. */
3914 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3916 target_last_wait_ptid = ptid;
3917 target_last_waitstatus = status;
3920 /* Return the cached copy of the last pid/waitstatus returned by
3921 target_wait()/deprecated_target_wait_hook(). The data is actually
3922 cached by handle_inferior_event(), which gets called immediately
3923 after target_wait()/deprecated_target_wait_hook(). */
3926 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3928 *ptidp = target_last_wait_ptid;
3929 *status = target_last_waitstatus;
3933 nullify_last_target_wait_ptid (void)
3935 target_last_wait_ptid = minus_one_ptid;
3938 /* Switch thread contexts. */
3941 context_switch (ptid_t ptid)
3943 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
3945 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3946 target_pid_to_str (inferior_ptid));
3947 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3948 target_pid_to_str (ptid));
3951 switch_to_thread (ptid);
3954 /* If the target can't tell whether we've hit breakpoints
3955 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3956 check whether that could have been caused by a breakpoint. If so,
3957 adjust the PC, per gdbarch_decr_pc_after_break. */
3960 adjust_pc_after_break (struct thread_info *thread,
3961 struct target_waitstatus *ws)
3963 struct regcache *regcache;
3964 struct gdbarch *gdbarch;
3965 struct address_space *aspace;
3966 CORE_ADDR breakpoint_pc, decr_pc;
3968 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3969 we aren't, just return.
3971 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3972 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3973 implemented by software breakpoints should be handled through the normal
3976 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3977 different signals (SIGILL or SIGEMT for instance), but it is less
3978 clear where the PC is pointing afterwards. It may not match
3979 gdbarch_decr_pc_after_break. I don't know any specific target that
3980 generates these signals at breakpoints (the code has been in GDB since at
3981 least 1992) so I can not guess how to handle them here.
3983 In earlier versions of GDB, a target with
3984 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3985 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3986 target with both of these set in GDB history, and it seems unlikely to be
3987 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3989 if (ws->kind != TARGET_WAITKIND_STOPPED)
3992 if (ws->value.sig != GDB_SIGNAL_TRAP)
3995 /* In reverse execution, when a breakpoint is hit, the instruction
3996 under it has already been de-executed. The reported PC always
3997 points at the breakpoint address, so adjusting it further would
3998 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4001 B1 0x08000000 : INSN1
4002 B2 0x08000001 : INSN2
4004 PC -> 0x08000003 : INSN4
4006 Say you're stopped at 0x08000003 as above. Reverse continuing
4007 from that point should hit B2 as below. Reading the PC when the
4008 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4009 been de-executed already.
4011 B1 0x08000000 : INSN1
4012 B2 PC -> 0x08000001 : INSN2
4016 We can't apply the same logic as for forward execution, because
4017 we would wrongly adjust the PC to 0x08000000, since there's a
4018 breakpoint at PC - 1. We'd then report a hit on B1, although
4019 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4021 if (execution_direction == EXEC_REVERSE)
4024 /* If the target can tell whether the thread hit a SW breakpoint,
4025 trust it. Targets that can tell also adjust the PC
4027 if (target_supports_stopped_by_sw_breakpoint ())
4030 /* Note that relying on whether a breakpoint is planted in memory to
4031 determine this can fail. E.g,. the breakpoint could have been
4032 removed since. Or the thread could have been told to step an
4033 instruction the size of a breakpoint instruction, and only
4034 _after_ was a breakpoint inserted at its address. */
4036 /* If this target does not decrement the PC after breakpoints, then
4037 we have nothing to do. */
4038 regcache = get_thread_regcache (thread->ptid);
4039 gdbarch = get_regcache_arch (regcache);
4041 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4045 aspace = get_regcache_aspace (regcache);
4047 /* Find the location where (if we've hit a breakpoint) the
4048 breakpoint would be. */
4049 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4051 /* If the target can't tell whether a software breakpoint triggered,
4052 fallback to figuring it out based on breakpoints we think were
4053 inserted in the target, and on whether the thread was stepped or
4056 /* Check whether there actually is a software breakpoint inserted at
4059 If in non-stop mode, a race condition is possible where we've
4060 removed a breakpoint, but stop events for that breakpoint were
4061 already queued and arrive later. To suppress those spurious
4062 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4063 and retire them after a number of stop events are reported. Note
4064 this is an heuristic and can thus get confused. The real fix is
4065 to get the "stopped by SW BP and needs adjustment" info out of
4066 the target/kernel (and thus never reach here; see above). */
4067 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4068 || (target_is_non_stop_p ()
4069 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4071 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4073 if (record_full_is_used ())
4074 record_full_gdb_operation_disable_set ();
4076 /* When using hardware single-step, a SIGTRAP is reported for both
4077 a completed single-step and a software breakpoint. Need to
4078 differentiate between the two, as the latter needs adjusting
4079 but the former does not.
4081 The SIGTRAP can be due to a completed hardware single-step only if
4082 - we didn't insert software single-step breakpoints
4083 - this thread is currently being stepped
4085 If any of these events did not occur, we must have stopped due
4086 to hitting a software breakpoint, and have to back up to the
4089 As a special case, we could have hardware single-stepped a
4090 software breakpoint. In this case (prev_pc == breakpoint_pc),
4091 we also need to back up to the breakpoint address. */
4093 if (thread_has_single_step_breakpoints_set (thread)
4094 || !currently_stepping (thread)
4095 || (thread->stepped_breakpoint
4096 && thread->prev_pc == breakpoint_pc))
4097 regcache_write_pc (regcache, breakpoint_pc);
4099 do_cleanups (old_cleanups);
4104 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4106 for (frame = get_prev_frame (frame);
4108 frame = get_prev_frame (frame))
4110 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4112 if (get_frame_type (frame) != INLINE_FRAME)
4119 /* Auxiliary function that handles syscall entry/return events.
4120 It returns 1 if the inferior should keep going (and GDB
4121 should ignore the event), or 0 if the event deserves to be
4125 handle_syscall_event (struct execution_control_state *ecs)
4127 struct regcache *regcache;
4130 if (!ptid_equal (ecs->ptid, inferior_ptid))
4131 context_switch (ecs->ptid);
4133 regcache = get_thread_regcache (ecs->ptid);
4134 syscall_number = ecs->ws.value.syscall_number;
4135 stop_pc = regcache_read_pc (regcache);
4137 if (catch_syscall_enabled () > 0
4138 && catching_syscall_number (syscall_number) > 0)
4141 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4144 ecs->event_thread->control.stop_bpstat
4145 = bpstat_stop_status (get_regcache_aspace (regcache),
4146 stop_pc, ecs->ptid, &ecs->ws);
4148 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4150 /* Catchpoint hit. */
4155 /* If no catchpoint triggered for this, then keep going. */
4160 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4163 fill_in_stop_func (struct gdbarch *gdbarch,
4164 struct execution_control_state *ecs)
4166 if (!ecs->stop_func_filled_in)
4168 /* Don't care about return value; stop_func_start and stop_func_name
4169 will both be 0 if it doesn't work. */
4170 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4171 &ecs->stop_func_start, &ecs->stop_func_end);
4172 ecs->stop_func_start
4173 += gdbarch_deprecated_function_start_offset (gdbarch);
4175 if (gdbarch_skip_entrypoint_p (gdbarch))
4176 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4177 ecs->stop_func_start);
4179 ecs->stop_func_filled_in = 1;
4184 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4186 static enum stop_kind
4187 get_inferior_stop_soon (ptid_t ptid)
4189 struct inferior *inf = find_inferior_ptid (ptid);
4191 gdb_assert (inf != NULL);
4192 return inf->control.stop_soon;
4195 /* Wait for one event. Store the resulting waitstatus in WS, and
4196 return the event ptid. */
4199 wait_one (struct target_waitstatus *ws)
4202 ptid_t wait_ptid = minus_one_ptid;
4204 overlay_cache_invalid = 1;
4206 /* Flush target cache before starting to handle each event.
4207 Target was running and cache could be stale. This is just a
4208 heuristic. Running threads may modify target memory, but we
4209 don't get any event. */
4210 target_dcache_invalidate ();
4212 if (deprecated_target_wait_hook)
4213 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4215 event_ptid = target_wait (wait_ptid, ws, 0);
4218 print_target_wait_results (wait_ptid, event_ptid, ws);
4223 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4224 instead of the current thread. */
4225 #define THREAD_STOPPED_BY(REASON) \
4227 thread_stopped_by_ ## REASON (ptid_t ptid) \
4229 struct cleanup *old_chain; \
4232 old_chain = save_inferior_ptid (); \
4233 inferior_ptid = ptid; \
4235 res = target_stopped_by_ ## REASON (); \
4237 do_cleanups (old_chain); \
4242 /* Generate thread_stopped_by_watchpoint. */
4243 THREAD_STOPPED_BY (watchpoint)
4244 /* Generate thread_stopped_by_sw_breakpoint. */
4245 THREAD_STOPPED_BY (sw_breakpoint)
4246 /* Generate thread_stopped_by_hw_breakpoint. */
4247 THREAD_STOPPED_BY (hw_breakpoint)
4249 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4252 switch_to_thread_cleanup (void *ptid_p)
4254 ptid_t ptid = *(ptid_t *) ptid_p;
4256 switch_to_thread (ptid);
4259 /* Save the thread's event and stop reason to process it later. */
4262 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4264 struct regcache *regcache;
4265 struct address_space *aspace;
4271 statstr = target_waitstatus_to_string (ws);
4272 fprintf_unfiltered (gdb_stdlog,
4273 "infrun: saving status %s for %d.%ld.%ld\n",
4275 ptid_get_pid (tp->ptid),
4276 ptid_get_lwp (tp->ptid),
4277 ptid_get_tid (tp->ptid));
4281 /* Record for later. */
4282 tp->suspend.waitstatus = *ws;
4283 tp->suspend.waitstatus_pending_p = 1;
4285 regcache = get_thread_regcache (tp->ptid);
4286 aspace = get_regcache_aspace (regcache);
4288 if (ws->kind == TARGET_WAITKIND_STOPPED
4289 && ws->value.sig == GDB_SIGNAL_TRAP)
4291 CORE_ADDR pc = regcache_read_pc (regcache);
4293 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4295 if (thread_stopped_by_watchpoint (tp->ptid))
4297 tp->suspend.stop_reason
4298 = TARGET_STOPPED_BY_WATCHPOINT;
4300 else if (target_supports_stopped_by_sw_breakpoint ()
4301 && thread_stopped_by_sw_breakpoint (tp->ptid))
4303 tp->suspend.stop_reason
4304 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4306 else if (target_supports_stopped_by_hw_breakpoint ()
4307 && thread_stopped_by_hw_breakpoint (tp->ptid))
4309 tp->suspend.stop_reason
4310 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4312 else if (!target_supports_stopped_by_hw_breakpoint ()
4313 && hardware_breakpoint_inserted_here_p (aspace,
4316 tp->suspend.stop_reason
4317 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4319 else if (!target_supports_stopped_by_sw_breakpoint ()
4320 && software_breakpoint_inserted_here_p (aspace,
4323 tp->suspend.stop_reason
4324 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4326 else if (!thread_has_single_step_breakpoints_set (tp)
4327 && currently_stepping (tp))
4329 tp->suspend.stop_reason
4330 = TARGET_STOPPED_BY_SINGLE_STEP;
4335 /* Stop all threads. */
4338 stop_all_threads (void)
4340 /* We may need multiple passes to discover all threads. */
4344 struct cleanup *old_chain;
4346 gdb_assert (target_is_non_stop_p ());
4349 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4351 entry_ptid = inferior_ptid;
4352 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4354 /* Request threads to stop, and then wait for the stops. Because
4355 threads we already know about can spawn more threads while we're
4356 trying to stop them, and we only learn about new threads when we
4357 update the thread list, do this in a loop, and keep iterating
4358 until two passes find no threads that need to be stopped. */
4359 for (pass = 0; pass < 2; pass++, iterations++)
4362 fprintf_unfiltered (gdb_stdlog,
4363 "infrun: stop_all_threads, pass=%d, "
4364 "iterations=%d\n", pass, iterations);
4368 struct target_waitstatus ws;
4370 struct thread_info *t;
4372 update_thread_list ();
4374 /* Go through all threads looking for threads that we need
4375 to tell the target to stop. */
4376 ALL_NON_EXITED_THREADS (t)
4380 /* If already stopping, don't request a stop again.
4381 We just haven't seen the notification yet. */
4382 if (!t->stop_requested)
4385 fprintf_unfiltered (gdb_stdlog,
4386 "infrun: %s executing, "
4388 target_pid_to_str (t->ptid));
4389 target_stop (t->ptid);
4390 t->stop_requested = 1;
4395 fprintf_unfiltered (gdb_stdlog,
4396 "infrun: %s executing, "
4397 "already stopping\n",
4398 target_pid_to_str (t->ptid));
4401 if (t->stop_requested)
4407 fprintf_unfiltered (gdb_stdlog,
4408 "infrun: %s not executing\n",
4409 target_pid_to_str (t->ptid));
4411 /* The thread may be not executing, but still be
4412 resumed with a pending status to process. */
4420 /* If we find new threads on the second iteration, restart
4421 over. We want to see two iterations in a row with all
4426 event_ptid = wait_one (&ws);
4427 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4429 /* All resumed threads exited. */
4431 else if (ws.kind == TARGET_WAITKIND_EXITED
4432 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4436 ptid_t ptid = pid_to_ptid (ws.value.integer);
4438 fprintf_unfiltered (gdb_stdlog,
4439 "infrun: %s exited while "
4440 "stopping threads\n",
4441 target_pid_to_str (ptid));
4446 t = find_thread_ptid (event_ptid);
4448 t = add_thread (event_ptid);
4450 t->stop_requested = 0;
4453 t->control.may_range_step = 0;
4455 if (ws.kind == TARGET_WAITKIND_STOPPED
4456 && ws.value.sig == GDB_SIGNAL_0)
4458 /* We caught the event that we intended to catch, so
4459 there's no event pending. */
4460 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4461 t->suspend.waitstatus_pending_p = 0;
4463 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4465 /* Add it back to the step-over queue. */
4468 fprintf_unfiltered (gdb_stdlog,
4469 "infrun: displaced-step of %s "
4470 "canceled: adding back to the "
4471 "step-over queue\n",
4472 target_pid_to_str (t->ptid));
4474 t->control.trap_expected = 0;
4475 thread_step_over_chain_enqueue (t);
4480 enum gdb_signal sig;
4481 struct regcache *regcache;
4482 struct address_space *aspace;
4488 statstr = target_waitstatus_to_string (&ws);
4489 fprintf_unfiltered (gdb_stdlog,
4490 "infrun: target_wait %s, saving "
4491 "status for %d.%ld.%ld\n",
4493 ptid_get_pid (t->ptid),
4494 ptid_get_lwp (t->ptid),
4495 ptid_get_tid (t->ptid));
4499 /* Record for later. */
4500 save_waitstatus (t, &ws);
4502 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4503 ? ws.value.sig : GDB_SIGNAL_0);
4505 if (displaced_step_fixup (t->ptid, sig) < 0)
4507 /* Add it back to the step-over queue. */
4508 t->control.trap_expected = 0;
4509 thread_step_over_chain_enqueue (t);
4512 regcache = get_thread_regcache (t->ptid);
4513 t->suspend.stop_pc = regcache_read_pc (regcache);
4517 fprintf_unfiltered (gdb_stdlog,
4518 "infrun: saved stop_pc=%s for %s "
4519 "(currently_stepping=%d)\n",
4520 paddress (target_gdbarch (),
4521 t->suspend.stop_pc),
4522 target_pid_to_str (t->ptid),
4523 currently_stepping (t));
4530 do_cleanups (old_chain);
4533 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4536 /* Given an execution control state that has been freshly filled in by
4537 an event from the inferior, figure out what it means and take
4540 The alternatives are:
4542 1) stop_waiting and return; to really stop and return to the
4545 2) keep_going and return; to wait for the next event (set
4546 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4550 handle_inferior_event_1 (struct execution_control_state *ecs)
4552 enum stop_kind stop_soon;
4554 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4556 /* We had an event in the inferior, but we are not interested in
4557 handling it at this level. The lower layers have already
4558 done what needs to be done, if anything.
4560 One of the possible circumstances for this is when the
4561 inferior produces output for the console. The inferior has
4562 not stopped, and we are ignoring the event. Another possible
4563 circumstance is any event which the lower level knows will be
4564 reported multiple times without an intervening resume. */
4566 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4567 prepare_to_wait (ecs);
4571 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4572 && target_can_async_p () && !sync_execution)
4574 /* There were no unwaited-for children left in the target, but,
4575 we're not synchronously waiting for events either. Just
4576 ignore. Otherwise, if we were running a synchronous
4577 execution command, we need to cancel it and give the user
4578 back the terminal. */
4580 fprintf_unfiltered (gdb_stdlog,
4581 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
4582 prepare_to_wait (ecs);
4586 /* Cache the last pid/waitstatus. */
4587 set_last_target_status (ecs->ptid, ecs->ws);
4589 /* Always clear state belonging to the previous time we stopped. */
4590 stop_stack_dummy = STOP_NONE;
4592 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4594 /* No unwaited-for children left. IOW, all resumed children
4597 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4599 stop_print_frame = 0;
4604 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4605 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4607 ecs->event_thread = find_thread_ptid (ecs->ptid);
4608 /* If it's a new thread, add it to the thread database. */
4609 if (ecs->event_thread == NULL)
4610 ecs->event_thread = add_thread (ecs->ptid);
4612 /* Disable range stepping. If the next step request could use a
4613 range, this will be end up re-enabled then. */
4614 ecs->event_thread->control.may_range_step = 0;
4617 /* Dependent on valid ECS->EVENT_THREAD. */
4618 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4620 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4621 reinit_frame_cache ();
4623 breakpoint_retire_moribund ();
4625 /* First, distinguish signals caused by the debugger from signals
4626 that have to do with the program's own actions. Note that
4627 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4628 on the operating system version. Here we detect when a SIGILL or
4629 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4630 something similar for SIGSEGV, since a SIGSEGV will be generated
4631 when we're trying to execute a breakpoint instruction on a
4632 non-executable stack. This happens for call dummy breakpoints
4633 for architectures like SPARC that place call dummies on the
4635 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4636 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4637 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4638 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4640 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4642 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
4643 regcache_read_pc (regcache)))
4646 fprintf_unfiltered (gdb_stdlog,
4647 "infrun: Treating signal as SIGTRAP\n");
4648 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4652 /* Mark the non-executing threads accordingly. In all-stop, all
4653 threads of all processes are stopped when we get any event
4654 reported. In non-stop mode, only the event thread stops. */
4658 if (!target_is_non_stop_p ())
4659 mark_ptid = minus_one_ptid;
4660 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4661 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4663 /* If we're handling a process exit in non-stop mode, even
4664 though threads haven't been deleted yet, one would think
4665 that there is nothing to do, as threads of the dead process
4666 will be soon deleted, and threads of any other process were
4667 left running. However, on some targets, threads survive a
4668 process exit event. E.g., for the "checkpoint" command,
4669 when the current checkpoint/fork exits, linux-fork.c
4670 automatically switches to another fork from within
4671 target_mourn_inferior, by associating the same
4672 inferior/thread to another fork. We haven't mourned yet at
4673 this point, but we must mark any threads left in the
4674 process as not-executing so that finish_thread_state marks
4675 them stopped (in the user's perspective) if/when we present
4676 the stop to the user. */
4677 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4680 mark_ptid = ecs->ptid;
4682 set_executing (mark_ptid, 0);
4684 /* Likewise the resumed flag. */
4685 set_resumed (mark_ptid, 0);
4688 switch (ecs->ws.kind)
4690 case TARGET_WAITKIND_LOADED:
4692 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4693 if (!ptid_equal (ecs->ptid, inferior_ptid))
4694 context_switch (ecs->ptid);
4695 /* Ignore gracefully during startup of the inferior, as it might
4696 be the shell which has just loaded some objects, otherwise
4697 add the symbols for the newly loaded objects. Also ignore at
4698 the beginning of an attach or remote session; we will query
4699 the full list of libraries once the connection is
4702 stop_soon = get_inferior_stop_soon (ecs->ptid);
4703 if (stop_soon == NO_STOP_QUIETLY)
4705 struct regcache *regcache;
4707 regcache = get_thread_regcache (ecs->ptid);
4709 handle_solib_event ();
4711 ecs->event_thread->control.stop_bpstat
4712 = bpstat_stop_status (get_regcache_aspace (regcache),
4713 stop_pc, ecs->ptid, &ecs->ws);
4715 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4717 /* A catchpoint triggered. */
4718 process_event_stop_test (ecs);
4722 /* If requested, stop when the dynamic linker notifies
4723 gdb of events. This allows the user to get control
4724 and place breakpoints in initializer routines for
4725 dynamically loaded objects (among other things). */
4726 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4727 if (stop_on_solib_events)
4729 /* Make sure we print "Stopped due to solib-event" in
4731 stop_print_frame = 1;
4738 /* If we are skipping through a shell, or through shared library
4739 loading that we aren't interested in, resume the program. If
4740 we're running the program normally, also resume. */
4741 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4743 /* Loading of shared libraries might have changed breakpoint
4744 addresses. Make sure new breakpoints are inserted. */
4745 if (stop_soon == NO_STOP_QUIETLY)
4746 insert_breakpoints ();
4747 resume (GDB_SIGNAL_0);
4748 prepare_to_wait (ecs);
4752 /* But stop if we're attaching or setting up a remote
4754 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4755 || stop_soon == STOP_QUIETLY_REMOTE)
4758 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4763 internal_error (__FILE__, __LINE__,
4764 _("unhandled stop_soon: %d"), (int) stop_soon);
4766 case TARGET_WAITKIND_SPURIOUS:
4768 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4769 if (!ptid_equal (ecs->ptid, inferior_ptid))
4770 context_switch (ecs->ptid);
4771 resume (GDB_SIGNAL_0);
4772 prepare_to_wait (ecs);
4775 case TARGET_WAITKIND_EXITED:
4776 case TARGET_WAITKIND_SIGNALLED:
4779 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4780 fprintf_unfiltered (gdb_stdlog,
4781 "infrun: TARGET_WAITKIND_EXITED\n");
4783 fprintf_unfiltered (gdb_stdlog,
4784 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4787 inferior_ptid = ecs->ptid;
4788 set_current_inferior (find_inferior_ptid (ecs->ptid));
4789 set_current_program_space (current_inferior ()->pspace);
4790 handle_vfork_child_exec_or_exit (0);
4791 target_terminal_ours (); /* Must do this before mourn anyway. */
4793 /* Clearing any previous state of convenience variables. */
4794 clear_exit_convenience_vars ();
4796 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4798 /* Record the exit code in the convenience variable $_exitcode, so
4799 that the user can inspect this again later. */
4800 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4801 (LONGEST) ecs->ws.value.integer);
4803 /* Also record this in the inferior itself. */
4804 current_inferior ()->has_exit_code = 1;
4805 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4807 /* Support the --return-child-result option. */
4808 return_child_result_value = ecs->ws.value.integer;
4810 observer_notify_exited (ecs->ws.value.integer);
4814 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4815 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4817 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4819 /* Set the value of the internal variable $_exitsignal,
4820 which holds the signal uncaught by the inferior. */
4821 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4822 gdbarch_gdb_signal_to_target (gdbarch,
4823 ecs->ws.value.sig));
4827 /* We don't have access to the target's method used for
4828 converting between signal numbers (GDB's internal
4829 representation <-> target's representation).
4830 Therefore, we cannot do a good job at displaying this
4831 information to the user. It's better to just warn
4832 her about it (if infrun debugging is enabled), and
4835 fprintf_filtered (gdb_stdlog, _("\
4836 Cannot fill $_exitsignal with the correct signal number.\n"));
4839 observer_notify_signal_exited (ecs->ws.value.sig);
4842 gdb_flush (gdb_stdout);
4843 target_mourn_inferior ();
4844 stop_print_frame = 0;
4848 /* The following are the only cases in which we keep going;
4849 the above cases end in a continue or goto. */
4850 case TARGET_WAITKIND_FORKED:
4851 case TARGET_WAITKIND_VFORKED:
4854 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4855 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4857 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4860 /* Check whether the inferior is displaced stepping. */
4862 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4863 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4864 struct displaced_step_inferior_state *displaced
4865 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
4867 /* If checking displaced stepping is supported, and thread
4868 ecs->ptid is displaced stepping. */
4869 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
4871 struct inferior *parent_inf
4872 = find_inferior_ptid (ecs->ptid);
4873 struct regcache *child_regcache;
4874 CORE_ADDR parent_pc;
4876 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4877 indicating that the displaced stepping of syscall instruction
4878 has been done. Perform cleanup for parent process here. Note
4879 that this operation also cleans up the child process for vfork,
4880 because their pages are shared. */
4881 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
4882 /* Start a new step-over in another thread if there's one
4886 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4888 /* Restore scratch pad for child process. */
4889 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4892 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4893 the child's PC is also within the scratchpad. Set the child's PC
4894 to the parent's PC value, which has already been fixed up.
4895 FIXME: we use the parent's aspace here, although we're touching
4896 the child, because the child hasn't been added to the inferior
4897 list yet at this point. */
4900 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4902 parent_inf->aspace);
4903 /* Read PC value of parent process. */
4904 parent_pc = regcache_read_pc (regcache);
4906 if (debug_displaced)
4907 fprintf_unfiltered (gdb_stdlog,
4908 "displaced: write child pc from %s to %s\n",
4910 regcache_read_pc (child_regcache)),
4911 paddress (gdbarch, parent_pc));
4913 regcache_write_pc (child_regcache, parent_pc);
4917 if (!ptid_equal (ecs->ptid, inferior_ptid))
4918 context_switch (ecs->ptid);
4920 /* Immediately detach breakpoints from the child before there's
4921 any chance of letting the user delete breakpoints from the
4922 breakpoint lists. If we don't do this early, it's easy to
4923 leave left over traps in the child, vis: "break foo; catch
4924 fork; c; <fork>; del; c; <child calls foo>". We only follow
4925 the fork on the last `continue', and by that time the
4926 breakpoint at "foo" is long gone from the breakpoint table.
4927 If we vforked, then we don't need to unpatch here, since both
4928 parent and child are sharing the same memory pages; we'll
4929 need to unpatch at follow/detach time instead to be certain
4930 that new breakpoints added between catchpoint hit time and
4931 vfork follow are detached. */
4932 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4934 /* This won't actually modify the breakpoint list, but will
4935 physically remove the breakpoints from the child. */
4936 detach_breakpoints (ecs->ws.value.related_pid);
4939 delete_just_stopped_threads_single_step_breakpoints ();
4941 /* In case the event is caught by a catchpoint, remember that
4942 the event is to be followed at the next resume of the thread,
4943 and not immediately. */
4944 ecs->event_thread->pending_follow = ecs->ws;
4946 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4948 ecs->event_thread->control.stop_bpstat
4949 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4950 stop_pc, ecs->ptid, &ecs->ws);
4952 /* If no catchpoint triggered for this, then keep going. Note
4953 that we're interested in knowing the bpstat actually causes a
4954 stop, not just if it may explain the signal. Software
4955 watchpoints, for example, always appear in the bpstat. */
4956 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4962 = (follow_fork_mode_string == follow_fork_mode_child);
4964 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4966 should_resume = follow_fork ();
4969 child = ecs->ws.value.related_pid;
4971 /* In non-stop mode, also resume the other branch. */
4972 if (!detach_fork && (non_stop
4973 || (sched_multi && target_is_non_stop_p ())))
4976 switch_to_thread (parent);
4978 switch_to_thread (child);
4980 ecs->event_thread = inferior_thread ();
4981 ecs->ptid = inferior_ptid;
4986 switch_to_thread (child);
4988 switch_to_thread (parent);
4990 ecs->event_thread = inferior_thread ();
4991 ecs->ptid = inferior_ptid;
4999 process_event_stop_test (ecs);
5002 case TARGET_WAITKIND_VFORK_DONE:
5003 /* Done with the shared memory region. Re-insert breakpoints in
5004 the parent, and keep going. */
5007 fprintf_unfiltered (gdb_stdlog,
5008 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5010 if (!ptid_equal (ecs->ptid, inferior_ptid))
5011 context_switch (ecs->ptid);
5013 current_inferior ()->waiting_for_vfork_done = 0;
5014 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5015 /* This also takes care of reinserting breakpoints in the
5016 previously locked inferior. */
5020 case TARGET_WAITKIND_EXECD:
5022 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5024 if (!ptid_equal (ecs->ptid, inferior_ptid))
5025 context_switch (ecs->ptid);
5027 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5029 /* Do whatever is necessary to the parent branch of the vfork. */
5030 handle_vfork_child_exec_or_exit (1);
5032 /* This causes the eventpoints and symbol table to be reset.
5033 Must do this now, before trying to determine whether to
5035 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5037 /* In follow_exec we may have deleted the original thread and
5038 created a new one. Make sure that the event thread is the
5039 execd thread for that case (this is a nop otherwise). */
5040 ecs->event_thread = inferior_thread ();
5042 ecs->event_thread->control.stop_bpstat
5043 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5044 stop_pc, ecs->ptid, &ecs->ws);
5046 /* Note that this may be referenced from inside
5047 bpstat_stop_status above, through inferior_has_execd. */
5048 xfree (ecs->ws.value.execd_pathname);
5049 ecs->ws.value.execd_pathname = NULL;
5051 /* If no catchpoint triggered for this, then keep going. */
5052 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5054 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5058 process_event_stop_test (ecs);
5061 /* Be careful not to try to gather much state about a thread
5062 that's in a syscall. It's frequently a losing proposition. */
5063 case TARGET_WAITKIND_SYSCALL_ENTRY:
5065 fprintf_unfiltered (gdb_stdlog,
5066 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5067 /* Getting the current syscall number. */
5068 if (handle_syscall_event (ecs) == 0)
5069 process_event_stop_test (ecs);
5072 /* Before examining the threads further, step this thread to
5073 get it entirely out of the syscall. (We get notice of the
5074 event when the thread is just on the verge of exiting a
5075 syscall. Stepping one instruction seems to get it back
5077 case TARGET_WAITKIND_SYSCALL_RETURN:
5079 fprintf_unfiltered (gdb_stdlog,
5080 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5081 if (handle_syscall_event (ecs) == 0)
5082 process_event_stop_test (ecs);
5085 case TARGET_WAITKIND_STOPPED:
5087 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5088 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5089 handle_signal_stop (ecs);
5092 case TARGET_WAITKIND_NO_HISTORY:
5094 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5095 /* Reverse execution: target ran out of history info. */
5097 delete_just_stopped_threads_single_step_breakpoints ();
5098 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5099 observer_notify_no_history ();
5105 /* A wrapper around handle_inferior_event_1, which also makes sure
5106 that all temporary struct value objects that were created during
5107 the handling of the event get deleted at the end. */
5110 handle_inferior_event (struct execution_control_state *ecs)
5112 struct value *mark = value_mark ();
5114 handle_inferior_event_1 (ecs);
5115 /* Purge all temporary values created during the event handling,
5116 as it could be a long time before we return to the command level
5117 where such values would otherwise be purged. */
5118 value_free_to_mark (mark);
5121 /* Restart threads back to what they were trying to do back when we
5122 paused them for an in-line step-over. The EVENT_THREAD thread is
5126 restart_threads (struct thread_info *event_thread)
5128 struct thread_info *tp;
5129 struct thread_info *step_over = NULL;
5131 /* In case the instruction just stepped spawned a new thread. */
5132 update_thread_list ();
5134 ALL_NON_EXITED_THREADS (tp)
5136 if (tp == event_thread)
5139 fprintf_unfiltered (gdb_stdlog,
5140 "infrun: restart threads: "
5141 "[%s] is event thread\n",
5142 target_pid_to_str (tp->ptid));
5146 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5149 fprintf_unfiltered (gdb_stdlog,
5150 "infrun: restart threads: "
5151 "[%s] not meant to be running\n",
5152 target_pid_to_str (tp->ptid));
5159 fprintf_unfiltered (gdb_stdlog,
5160 "infrun: restart threads: [%s] resumed\n",
5161 target_pid_to_str (tp->ptid));
5162 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5166 if (thread_is_in_step_over_chain (tp))
5169 fprintf_unfiltered (gdb_stdlog,
5170 "infrun: restart threads: "
5171 "[%s] needs step-over\n",
5172 target_pid_to_str (tp->ptid));
5173 gdb_assert (!tp->resumed);
5178 if (tp->suspend.waitstatus_pending_p)
5181 fprintf_unfiltered (gdb_stdlog,
5182 "infrun: restart threads: "
5183 "[%s] has pending status\n",
5184 target_pid_to_str (tp->ptid));
5189 /* If some thread needs to start a step-over at this point, it
5190 should still be in the step-over queue, and thus skipped
5192 if (thread_still_needs_step_over (tp))
5194 internal_error (__FILE__, __LINE__,
5195 "thread [%s] needs a step-over, but not in "
5196 "step-over queue\n",
5197 target_pid_to_str (tp->ptid));
5200 if (currently_stepping (tp))
5203 fprintf_unfiltered (gdb_stdlog,
5204 "infrun: restart threads: [%s] was stepping\n",
5205 target_pid_to_str (tp->ptid));
5206 keep_going_stepped_thread (tp);
5210 struct execution_control_state ecss;
5211 struct execution_control_state *ecs = &ecss;
5214 fprintf_unfiltered (gdb_stdlog,
5215 "infrun: restart threads: [%s] continuing\n",
5216 target_pid_to_str (tp->ptid));
5217 reset_ecs (ecs, tp);
5218 switch_to_thread (tp->ptid);
5219 keep_going_pass_signal (ecs);
5224 /* Callback for iterate_over_threads. Find a resumed thread that has
5225 a pending waitstatus. */
5228 resumed_thread_with_pending_status (struct thread_info *tp,
5232 && tp->suspend.waitstatus_pending_p);
5235 /* Called when we get an event that may finish an in-line or
5236 out-of-line (displaced stepping) step-over started previously.
5237 Return true if the event is processed and we should go back to the
5238 event loop; false if the caller should continue processing the
5242 finish_step_over (struct execution_control_state *ecs)
5244 int had_step_over_info;
5246 displaced_step_fixup (ecs->ptid,
5247 ecs->event_thread->suspend.stop_signal);
5249 had_step_over_info = step_over_info_valid_p ();
5251 if (had_step_over_info)
5253 /* If we're stepping over a breakpoint with all threads locked,
5254 then only the thread that was stepped should be reporting
5256 gdb_assert (ecs->event_thread->control.trap_expected);
5258 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5259 clear_step_over_info ();
5262 if (!target_is_non_stop_p ())
5265 /* Start a new step-over in another thread if there's one that
5269 /* If we were stepping over a breakpoint before, and haven't started
5270 a new in-line step-over sequence, then restart all other threads
5271 (except the event thread). We can't do this in all-stop, as then
5272 e.g., we wouldn't be able to issue any other remote packet until
5273 these other threads stop. */
5274 if (had_step_over_info && !step_over_info_valid_p ())
5276 struct thread_info *pending;
5278 /* If we only have threads with pending statuses, the restart
5279 below won't restart any thread and so nothing re-inserts the
5280 breakpoint we just stepped over. But we need it inserted
5281 when we later process the pending events, otherwise if
5282 another thread has a pending event for this breakpoint too,
5283 we'd discard its event (because the breakpoint that
5284 originally caused the event was no longer inserted). */
5285 context_switch (ecs->ptid);
5286 insert_breakpoints ();
5288 restart_threads (ecs->event_thread);
5290 /* If we have events pending, go through handle_inferior_event
5291 again, picking up a pending event at random. This avoids
5292 thread starvation. */
5294 /* But not if we just stepped over a watchpoint in order to let
5295 the instruction execute so we can evaluate its expression.
5296 The set of watchpoints that triggered is recorded in the
5297 breakpoint objects themselves (see bp->watchpoint_triggered).
5298 If we processed another event first, that other event could
5299 clobber this info. */
5300 if (ecs->event_thread->stepping_over_watchpoint)
5303 pending = iterate_over_threads (resumed_thread_with_pending_status,
5305 if (pending != NULL)
5307 struct thread_info *tp = ecs->event_thread;
5308 struct regcache *regcache;
5312 fprintf_unfiltered (gdb_stdlog,
5313 "infrun: found resumed threads with "
5314 "pending events, saving status\n");
5317 gdb_assert (pending != tp);
5319 /* Record the event thread's event for later. */
5320 save_waitstatus (tp, &ecs->ws);
5321 /* This was cleared early, by handle_inferior_event. Set it
5322 so this pending event is considered by
5326 gdb_assert (!tp->executing);
5328 regcache = get_thread_regcache (tp->ptid);
5329 tp->suspend.stop_pc = regcache_read_pc (regcache);
5333 fprintf_unfiltered (gdb_stdlog,
5334 "infrun: saved stop_pc=%s for %s "
5335 "(currently_stepping=%d)\n",
5336 paddress (target_gdbarch (),
5337 tp->suspend.stop_pc),
5338 target_pid_to_str (tp->ptid),
5339 currently_stepping (tp));
5342 /* This in-line step-over finished; clear this so we won't
5343 start a new one. This is what handle_signal_stop would
5344 do, if we returned false. */
5345 tp->stepping_over_breakpoint = 0;
5347 /* Wake up the event loop again. */
5348 mark_async_event_handler (infrun_async_inferior_event_token);
5350 prepare_to_wait (ecs);
5358 /* Come here when the program has stopped with a signal. */
5361 handle_signal_stop (struct execution_control_state *ecs)
5363 struct frame_info *frame;
5364 struct gdbarch *gdbarch;
5365 int stopped_by_watchpoint;
5366 enum stop_kind stop_soon;
5369 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5371 /* Do we need to clean up the state of a thread that has
5372 completed a displaced single-step? (Doing so usually affects
5373 the PC, so do it here, before we set stop_pc.) */
5374 if (finish_step_over (ecs))
5377 /* If we either finished a single-step or hit a breakpoint, but
5378 the user wanted this thread to be stopped, pretend we got a
5379 SIG0 (generic unsignaled stop). */
5380 if (ecs->event_thread->stop_requested
5381 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5382 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5384 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5388 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5389 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5390 struct cleanup *old_chain = save_inferior_ptid ();
5392 inferior_ptid = ecs->ptid;
5394 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5395 paddress (gdbarch, stop_pc));
5396 if (target_stopped_by_watchpoint ())
5400 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5402 if (target_stopped_data_address (¤t_target, &addr))
5403 fprintf_unfiltered (gdb_stdlog,
5404 "infrun: stopped data address = %s\n",
5405 paddress (gdbarch, addr));
5407 fprintf_unfiltered (gdb_stdlog,
5408 "infrun: (no data address available)\n");
5411 do_cleanups (old_chain);
5414 /* This is originated from start_remote(), start_inferior() and
5415 shared libraries hook functions. */
5416 stop_soon = get_inferior_stop_soon (ecs->ptid);
5417 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5419 if (!ptid_equal (ecs->ptid, inferior_ptid))
5420 context_switch (ecs->ptid);
5422 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5423 stop_print_frame = 1;
5428 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5431 if (!ptid_equal (ecs->ptid, inferior_ptid))
5432 context_switch (ecs->ptid);
5434 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5435 stop_print_frame = 0;
5440 /* This originates from attach_command(). We need to overwrite
5441 the stop_signal here, because some kernels don't ignore a
5442 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5443 See more comments in inferior.h. On the other hand, if we
5444 get a non-SIGSTOP, report it to the user - assume the backend
5445 will handle the SIGSTOP if it should show up later.
5447 Also consider that the attach is complete when we see a
5448 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5449 target extended-remote report it instead of a SIGSTOP
5450 (e.g. gdbserver). We already rely on SIGTRAP being our
5451 signal, so this is no exception.
5453 Also consider that the attach is complete when we see a
5454 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5455 the target to stop all threads of the inferior, in case the
5456 low level attach operation doesn't stop them implicitly. If
5457 they weren't stopped implicitly, then the stub will report a
5458 GDB_SIGNAL_0, meaning: stopped for no particular reason
5459 other than GDB's request. */
5460 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5461 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5462 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5463 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5465 stop_print_frame = 1;
5467 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5471 /* See if something interesting happened to the non-current thread. If
5472 so, then switch to that thread. */
5473 if (!ptid_equal (ecs->ptid, inferior_ptid))
5476 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5478 context_switch (ecs->ptid);
5480 if (deprecated_context_hook)
5481 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
5484 /* At this point, get hold of the now-current thread's frame. */
5485 frame = get_current_frame ();
5486 gdbarch = get_frame_arch (frame);
5488 /* Pull the single step breakpoints out of the target. */
5489 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5491 struct regcache *regcache;
5492 struct address_space *aspace;
5495 regcache = get_thread_regcache (ecs->ptid);
5496 aspace = get_regcache_aspace (regcache);
5497 pc = regcache_read_pc (regcache);
5499 /* However, before doing so, if this single-step breakpoint was
5500 actually for another thread, set this thread up for moving
5502 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5505 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5509 fprintf_unfiltered (gdb_stdlog,
5510 "infrun: [%s] hit another thread's "
5511 "single-step breakpoint\n",
5512 target_pid_to_str (ecs->ptid));
5514 ecs->hit_singlestep_breakpoint = 1;
5521 fprintf_unfiltered (gdb_stdlog,
5522 "infrun: [%s] hit its "
5523 "single-step breakpoint\n",
5524 target_pid_to_str (ecs->ptid));
5528 delete_just_stopped_threads_single_step_breakpoints ();
5530 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5531 && ecs->event_thread->control.trap_expected
5532 && ecs->event_thread->stepping_over_watchpoint)
5533 stopped_by_watchpoint = 0;
5535 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5537 /* If necessary, step over this watchpoint. We'll be back to display
5539 if (stopped_by_watchpoint
5540 && (target_have_steppable_watchpoint
5541 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5543 /* At this point, we are stopped at an instruction which has
5544 attempted to write to a piece of memory under control of
5545 a watchpoint. The instruction hasn't actually executed
5546 yet. If we were to evaluate the watchpoint expression
5547 now, we would get the old value, and therefore no change
5548 would seem to have occurred.
5550 In order to make watchpoints work `right', we really need
5551 to complete the memory write, and then evaluate the
5552 watchpoint expression. We do this by single-stepping the
5555 It may not be necessary to disable the watchpoint to step over
5556 it. For example, the PA can (with some kernel cooperation)
5557 single step over a watchpoint without disabling the watchpoint.
5559 It is far more common to need to disable a watchpoint to step
5560 the inferior over it. If we have non-steppable watchpoints,
5561 we must disable the current watchpoint; it's simplest to
5562 disable all watchpoints.
5564 Any breakpoint at PC must also be stepped over -- if there's
5565 one, it will have already triggered before the watchpoint
5566 triggered, and we either already reported it to the user, or
5567 it didn't cause a stop and we called keep_going. In either
5568 case, if there was a breakpoint at PC, we must be trying to
5570 ecs->event_thread->stepping_over_watchpoint = 1;
5575 ecs->event_thread->stepping_over_breakpoint = 0;
5576 ecs->event_thread->stepping_over_watchpoint = 0;
5577 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5578 ecs->event_thread->control.stop_step = 0;
5579 stop_print_frame = 1;
5580 stopped_by_random_signal = 0;
5582 /* Hide inlined functions starting here, unless we just performed stepi or
5583 nexti. After stepi and nexti, always show the innermost frame (not any
5584 inline function call sites). */
5585 if (ecs->event_thread->control.step_range_end != 1)
5587 struct address_space *aspace =
5588 get_regcache_aspace (get_thread_regcache (ecs->ptid));
5590 /* skip_inline_frames is expensive, so we avoid it if we can
5591 determine that the address is one where functions cannot have
5592 been inlined. This improves performance with inferiors that
5593 load a lot of shared libraries, because the solib event
5594 breakpoint is defined as the address of a function (i.e. not
5595 inline). Note that we have to check the previous PC as well
5596 as the current one to catch cases when we have just
5597 single-stepped off a breakpoint prior to reinstating it.
5598 Note that we're assuming that the code we single-step to is
5599 not inline, but that's not definitive: there's nothing
5600 preventing the event breakpoint function from containing
5601 inlined code, and the single-step ending up there. If the
5602 user had set a breakpoint on that inlined code, the missing
5603 skip_inline_frames call would break things. Fortunately
5604 that's an extremely unlikely scenario. */
5605 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5606 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5607 && ecs->event_thread->control.trap_expected
5608 && pc_at_non_inline_function (aspace,
5609 ecs->event_thread->prev_pc,
5612 skip_inline_frames (ecs->ptid);
5614 /* Re-fetch current thread's frame in case that invalidated
5616 frame = get_current_frame ();
5617 gdbarch = get_frame_arch (frame);
5621 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5622 && ecs->event_thread->control.trap_expected
5623 && gdbarch_single_step_through_delay_p (gdbarch)
5624 && currently_stepping (ecs->event_thread))
5626 /* We're trying to step off a breakpoint. Turns out that we're
5627 also on an instruction that needs to be stepped multiple
5628 times before it's been fully executing. E.g., architectures
5629 with a delay slot. It needs to be stepped twice, once for
5630 the instruction and once for the delay slot. */
5631 int step_through_delay
5632 = gdbarch_single_step_through_delay (gdbarch, frame);
5634 if (debug_infrun && step_through_delay)
5635 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5636 if (ecs->event_thread->control.step_range_end == 0
5637 && step_through_delay)
5639 /* The user issued a continue when stopped at a breakpoint.
5640 Set up for another trap and get out of here. */
5641 ecs->event_thread->stepping_over_breakpoint = 1;
5645 else if (step_through_delay)
5647 /* The user issued a step when stopped at a breakpoint.
5648 Maybe we should stop, maybe we should not - the delay
5649 slot *might* correspond to a line of source. In any
5650 case, don't decide that here, just set
5651 ecs->stepping_over_breakpoint, making sure we
5652 single-step again before breakpoints are re-inserted. */
5653 ecs->event_thread->stepping_over_breakpoint = 1;
5657 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5658 handles this event. */
5659 ecs->event_thread->control.stop_bpstat
5660 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5661 stop_pc, ecs->ptid, &ecs->ws);
5663 /* Following in case break condition called a
5665 stop_print_frame = 1;
5667 /* This is where we handle "moribund" watchpoints. Unlike
5668 software breakpoints traps, hardware watchpoint traps are
5669 always distinguishable from random traps. If no high-level
5670 watchpoint is associated with the reported stop data address
5671 anymore, then the bpstat does not explain the signal ---
5672 simply make sure to ignore it if `stopped_by_watchpoint' is
5676 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5677 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5679 && stopped_by_watchpoint)
5680 fprintf_unfiltered (gdb_stdlog,
5681 "infrun: no user watchpoint explains "
5682 "watchpoint SIGTRAP, ignoring\n");
5684 /* NOTE: cagney/2003-03-29: These checks for a random signal
5685 at one stage in the past included checks for an inferior
5686 function call's call dummy's return breakpoint. The original
5687 comment, that went with the test, read:
5689 ``End of a stack dummy. Some systems (e.g. Sony news) give
5690 another signal besides SIGTRAP, so check here as well as
5693 If someone ever tries to get call dummys on a
5694 non-executable stack to work (where the target would stop
5695 with something like a SIGSEGV), then those tests might need
5696 to be re-instated. Given, however, that the tests were only
5697 enabled when momentary breakpoints were not being used, I
5698 suspect that it won't be the case.
5700 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5701 be necessary for call dummies on a non-executable stack on
5704 /* See if the breakpoints module can explain the signal. */
5706 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5707 ecs->event_thread->suspend.stop_signal);
5709 /* Maybe this was a trap for a software breakpoint that has since
5711 if (random_signal && target_stopped_by_sw_breakpoint ())
5713 if (program_breakpoint_here_p (gdbarch, stop_pc))
5715 struct regcache *regcache;
5718 /* Re-adjust PC to what the program would see if GDB was not
5720 regcache = get_thread_regcache (ecs->event_thread->ptid);
5721 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5724 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
5726 if (record_full_is_used ())
5727 record_full_gdb_operation_disable_set ();
5729 regcache_write_pc (regcache, stop_pc + decr_pc);
5731 do_cleanups (old_cleanups);
5736 /* A delayed software breakpoint event. Ignore the trap. */
5738 fprintf_unfiltered (gdb_stdlog,
5739 "infrun: delayed software breakpoint "
5740 "trap, ignoring\n");
5745 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5746 has since been removed. */
5747 if (random_signal && target_stopped_by_hw_breakpoint ())
5749 /* A delayed hardware breakpoint event. Ignore the trap. */
5751 fprintf_unfiltered (gdb_stdlog,
5752 "infrun: delayed hardware breakpoint/watchpoint "
5753 "trap, ignoring\n");
5757 /* If not, perhaps stepping/nexting can. */
5759 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5760 && currently_stepping (ecs->event_thread));
5762 /* Perhaps the thread hit a single-step breakpoint of _another_
5763 thread. Single-step breakpoints are transparent to the
5764 breakpoints module. */
5766 random_signal = !ecs->hit_singlestep_breakpoint;
5768 /* No? Perhaps we got a moribund watchpoint. */
5770 random_signal = !stopped_by_watchpoint;
5772 /* For the program's own signals, act according to
5773 the signal handling tables. */
5777 /* Signal not for debugging purposes. */
5778 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5779 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5782 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5783 gdb_signal_to_symbol_string (stop_signal));
5785 stopped_by_random_signal = 1;
5787 /* Always stop on signals if we're either just gaining control
5788 of the program, or the user explicitly requested this thread
5789 to remain stopped. */
5790 if (stop_soon != NO_STOP_QUIETLY
5791 || ecs->event_thread->stop_requested
5793 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5799 /* Notify observers the signal has "handle print" set. Note we
5800 returned early above if stopping; normal_stop handles the
5801 printing in that case. */
5802 if (signal_print[ecs->event_thread->suspend.stop_signal])
5804 /* The signal table tells us to print about this signal. */
5805 target_terminal_ours_for_output ();
5806 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
5807 target_terminal_inferior ();
5810 /* Clear the signal if it should not be passed. */
5811 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5812 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5814 if (ecs->event_thread->prev_pc == stop_pc
5815 && ecs->event_thread->control.trap_expected
5816 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5820 /* We were just starting a new sequence, attempting to
5821 single-step off of a breakpoint and expecting a SIGTRAP.
5822 Instead this signal arrives. This signal will take us out
5823 of the stepping range so GDB needs to remember to, when
5824 the signal handler returns, resume stepping off that
5826 /* To simplify things, "continue" is forced to use the same
5827 code paths as single-step - set a breakpoint at the
5828 signal return address and then, once hit, step off that
5831 fprintf_unfiltered (gdb_stdlog,
5832 "infrun: signal arrived while stepping over "
5835 was_in_line = step_over_info_valid_p ();
5836 clear_step_over_info ();
5837 insert_hp_step_resume_breakpoint_at_frame (frame);
5838 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5839 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5840 ecs->event_thread->control.trap_expected = 0;
5842 if (target_is_non_stop_p ())
5844 /* Either "set non-stop" is "on", or the target is
5845 always in non-stop mode. In this case, we have a bit
5846 more work to do. Resume the current thread, and if
5847 we had paused all threads, restart them while the
5848 signal handler runs. */
5853 restart_threads (ecs->event_thread);
5855 else if (debug_infrun)
5857 fprintf_unfiltered (gdb_stdlog,
5858 "infrun: no need to restart threads\n");
5863 /* If we were nexting/stepping some other thread, switch to
5864 it, so that we don't continue it, losing control. */
5865 if (!switch_back_to_stepped_thread (ecs))
5870 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5871 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
5872 || ecs->event_thread->control.step_range_end == 1)
5873 && frame_id_eq (get_stack_frame_id (frame),
5874 ecs->event_thread->control.step_stack_frame_id)
5875 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5877 /* The inferior is about to take a signal that will take it
5878 out of the single step range. Set a breakpoint at the
5879 current PC (which is presumably where the signal handler
5880 will eventually return) and then allow the inferior to
5883 Note that this is only needed for a signal delivered
5884 while in the single-step range. Nested signals aren't a
5885 problem as they eventually all return. */
5887 fprintf_unfiltered (gdb_stdlog,
5888 "infrun: signal may take us out of "
5889 "single-step range\n");
5891 clear_step_over_info ();
5892 insert_hp_step_resume_breakpoint_at_frame (frame);
5893 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5894 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5895 ecs->event_thread->control.trap_expected = 0;
5900 /* Note: step_resume_breakpoint may be non-NULL. This occures
5901 when either there's a nested signal, or when there's a
5902 pending signal enabled just as the signal handler returns
5903 (leaving the inferior at the step-resume-breakpoint without
5904 actually executing it). Either way continue until the
5905 breakpoint is really hit. */
5907 if (!switch_back_to_stepped_thread (ecs))
5910 fprintf_unfiltered (gdb_stdlog,
5911 "infrun: random signal, keep going\n");
5918 process_event_stop_test (ecs);
5921 /* Come here when we've got some debug event / signal we can explain
5922 (IOW, not a random signal), and test whether it should cause a
5923 stop, or whether we should resume the inferior (transparently).
5924 E.g., could be a breakpoint whose condition evaluates false; we
5925 could be still stepping within the line; etc. */
5928 process_event_stop_test (struct execution_control_state *ecs)
5930 struct symtab_and_line stop_pc_sal;
5931 struct frame_info *frame;
5932 struct gdbarch *gdbarch;
5933 CORE_ADDR jmp_buf_pc;
5934 struct bpstat_what what;
5936 /* Handle cases caused by hitting a breakpoint. */
5938 frame = get_current_frame ();
5939 gdbarch = get_frame_arch (frame);
5941 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
5943 if (what.call_dummy)
5945 stop_stack_dummy = what.call_dummy;
5948 /* A few breakpoint types have callbacks associated (e.g.,
5949 bp_jit_event). Run them now. */
5950 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
5952 /* If we hit an internal event that triggers symbol changes, the
5953 current frame will be invalidated within bpstat_what (e.g., if we
5954 hit an internal solib event). Re-fetch it. */
5955 frame = get_current_frame ();
5956 gdbarch = get_frame_arch (frame);
5958 switch (what.main_action)
5960 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
5961 /* If we hit the breakpoint at longjmp while stepping, we
5962 install a momentary breakpoint at the target of the
5966 fprintf_unfiltered (gdb_stdlog,
5967 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
5969 ecs->event_thread->stepping_over_breakpoint = 1;
5971 if (what.is_longjmp)
5973 struct value *arg_value;
5975 /* If we set the longjmp breakpoint via a SystemTap probe,
5976 then use it to extract the arguments. The destination PC
5977 is the third argument to the probe. */
5978 arg_value = probe_safe_evaluate_at_pc (frame, 2);
5981 jmp_buf_pc = value_as_address (arg_value);
5982 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
5984 else if (!gdbarch_get_longjmp_target_p (gdbarch)
5985 || !gdbarch_get_longjmp_target (gdbarch,
5986 frame, &jmp_buf_pc))
5989 fprintf_unfiltered (gdb_stdlog,
5990 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
5991 "(!gdbarch_get_longjmp_target)\n");
5996 /* Insert a breakpoint at resume address. */
5997 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6000 check_exception_resume (ecs, frame);
6004 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6006 struct frame_info *init_frame;
6008 /* There are several cases to consider.
6010 1. The initiating frame no longer exists. In this case we
6011 must stop, because the exception or longjmp has gone too
6014 2. The initiating frame exists, and is the same as the
6015 current frame. We stop, because the exception or longjmp
6018 3. The initiating frame exists and is different from the
6019 current frame. This means the exception or longjmp has
6020 been caught beneath the initiating frame, so keep going.
6022 4. longjmp breakpoint has been placed just to protect
6023 against stale dummy frames and user is not interested in
6024 stopping around longjmps. */
6027 fprintf_unfiltered (gdb_stdlog,
6028 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6030 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6032 delete_exception_resume_breakpoint (ecs->event_thread);
6034 if (what.is_longjmp)
6036 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6038 if (!frame_id_p (ecs->event_thread->initiating_frame))
6046 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6050 struct frame_id current_id
6051 = get_frame_id (get_current_frame ());
6052 if (frame_id_eq (current_id,
6053 ecs->event_thread->initiating_frame))
6055 /* Case 2. Fall through. */
6065 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6067 delete_step_resume_breakpoint (ecs->event_thread);
6069 end_stepping_range (ecs);
6073 case BPSTAT_WHAT_SINGLE:
6075 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6076 ecs->event_thread->stepping_over_breakpoint = 1;
6077 /* Still need to check other stuff, at least the case where we
6078 are stepping and step out of the right range. */
6081 case BPSTAT_WHAT_STEP_RESUME:
6083 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6085 delete_step_resume_breakpoint (ecs->event_thread);
6086 if (ecs->event_thread->control.proceed_to_finish
6087 && execution_direction == EXEC_REVERSE)
6089 struct thread_info *tp = ecs->event_thread;
6091 /* We are finishing a function in reverse, and just hit the
6092 step-resume breakpoint at the start address of the
6093 function, and we're almost there -- just need to back up
6094 by one more single-step, which should take us back to the
6096 tp->control.step_range_start = tp->control.step_range_end = 1;
6100 fill_in_stop_func (gdbarch, ecs);
6101 if (stop_pc == ecs->stop_func_start
6102 && execution_direction == EXEC_REVERSE)
6104 /* We are stepping over a function call in reverse, and just
6105 hit the step-resume breakpoint at the start address of
6106 the function. Go back to single-stepping, which should
6107 take us back to the function call. */
6108 ecs->event_thread->stepping_over_breakpoint = 1;
6114 case BPSTAT_WHAT_STOP_NOISY:
6116 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6117 stop_print_frame = 1;
6119 /* Assume the thread stopped for a breapoint. We'll still check
6120 whether a/the breakpoint is there when the thread is next
6122 ecs->event_thread->stepping_over_breakpoint = 1;
6127 case BPSTAT_WHAT_STOP_SILENT:
6129 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6130 stop_print_frame = 0;
6132 /* Assume the thread stopped for a breapoint. We'll still check
6133 whether a/the breakpoint is there when the thread is next
6135 ecs->event_thread->stepping_over_breakpoint = 1;
6139 case BPSTAT_WHAT_HP_STEP_RESUME:
6141 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6143 delete_step_resume_breakpoint (ecs->event_thread);
6144 if (ecs->event_thread->step_after_step_resume_breakpoint)
6146 /* Back when the step-resume breakpoint was inserted, we
6147 were trying to single-step off a breakpoint. Go back to
6149 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6150 ecs->event_thread->stepping_over_breakpoint = 1;
6156 case BPSTAT_WHAT_KEEP_CHECKING:
6160 /* If we stepped a permanent breakpoint and we had a high priority
6161 step-resume breakpoint for the address we stepped, but we didn't
6162 hit it, then we must have stepped into the signal handler. The
6163 step-resume was only necessary to catch the case of _not_
6164 stepping into the handler, so delete it, and fall through to
6165 checking whether the step finished. */
6166 if (ecs->event_thread->stepped_breakpoint)
6168 struct breakpoint *sr_bp
6169 = ecs->event_thread->control.step_resume_breakpoint;
6172 && sr_bp->loc->permanent
6173 && sr_bp->type == bp_hp_step_resume
6174 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6177 fprintf_unfiltered (gdb_stdlog,
6178 "infrun: stepped permanent breakpoint, stopped in "
6180 delete_step_resume_breakpoint (ecs->event_thread);
6181 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6185 /* We come here if we hit a breakpoint but should not stop for it.
6186 Possibly we also were stepping and should stop for that. So fall
6187 through and test for stepping. But, if not stepping, do not
6190 /* In all-stop mode, if we're currently stepping but have stopped in
6191 some other thread, we need to switch back to the stepped thread. */
6192 if (switch_back_to_stepped_thread (ecs))
6195 if (ecs->event_thread->control.step_resume_breakpoint)
6198 fprintf_unfiltered (gdb_stdlog,
6199 "infrun: step-resume breakpoint is inserted\n");
6201 /* Having a step-resume breakpoint overrides anything
6202 else having to do with stepping commands until
6203 that breakpoint is reached. */
6208 if (ecs->event_thread->control.step_range_end == 0)
6211 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6212 /* Likewise if we aren't even stepping. */
6217 /* Re-fetch current thread's frame in case the code above caused
6218 the frame cache to be re-initialized, making our FRAME variable
6219 a dangling pointer. */
6220 frame = get_current_frame ();
6221 gdbarch = get_frame_arch (frame);
6222 fill_in_stop_func (gdbarch, ecs);
6224 /* If stepping through a line, keep going if still within it.
6226 Note that step_range_end is the address of the first instruction
6227 beyond the step range, and NOT the address of the last instruction
6230 Note also that during reverse execution, we may be stepping
6231 through a function epilogue and therefore must detect when
6232 the current-frame changes in the middle of a line. */
6234 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6235 && (execution_direction != EXEC_REVERSE
6236 || frame_id_eq (get_frame_id (frame),
6237 ecs->event_thread->control.step_frame_id)))
6241 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6242 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6243 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6245 /* Tentatively re-enable range stepping; `resume' disables it if
6246 necessary (e.g., if we're stepping over a breakpoint or we
6247 have software watchpoints). */
6248 ecs->event_thread->control.may_range_step = 1;
6250 /* When stepping backward, stop at beginning of line range
6251 (unless it's the function entry point, in which case
6252 keep going back to the call point). */
6253 if (stop_pc == ecs->event_thread->control.step_range_start
6254 && stop_pc != ecs->stop_func_start
6255 && execution_direction == EXEC_REVERSE)
6256 end_stepping_range (ecs);
6263 /* We stepped out of the stepping range. */
6265 /* If we are stepping at the source level and entered the runtime
6266 loader dynamic symbol resolution code...
6268 EXEC_FORWARD: we keep on single stepping until we exit the run
6269 time loader code and reach the callee's address.
6271 EXEC_REVERSE: we've already executed the callee (backward), and
6272 the runtime loader code is handled just like any other
6273 undebuggable function call. Now we need only keep stepping
6274 backward through the trampoline code, and that's handled further
6275 down, so there is nothing for us to do here. */
6277 if (execution_direction != EXEC_REVERSE
6278 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6279 && in_solib_dynsym_resolve_code (stop_pc))
6281 CORE_ADDR pc_after_resolver =
6282 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6285 fprintf_unfiltered (gdb_stdlog,
6286 "infrun: stepped into dynsym resolve code\n");
6288 if (pc_after_resolver)
6290 /* Set up a step-resume breakpoint at the address
6291 indicated by SKIP_SOLIB_RESOLVER. */
6292 struct symtab_and_line sr_sal;
6295 sr_sal.pc = pc_after_resolver;
6296 sr_sal.pspace = get_frame_program_space (frame);
6298 insert_step_resume_breakpoint_at_sal (gdbarch,
6299 sr_sal, null_frame_id);
6306 if (ecs->event_thread->control.step_range_end != 1
6307 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6308 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6309 && get_frame_type (frame) == SIGTRAMP_FRAME)
6312 fprintf_unfiltered (gdb_stdlog,
6313 "infrun: stepped into signal trampoline\n");
6314 /* The inferior, while doing a "step" or "next", has ended up in
6315 a signal trampoline (either by a signal being delivered or by
6316 the signal handler returning). Just single-step until the
6317 inferior leaves the trampoline (either by calling the handler
6323 /* If we're in the return path from a shared library trampoline,
6324 we want to proceed through the trampoline when stepping. */
6325 /* macro/2012-04-25: This needs to come before the subroutine
6326 call check below as on some targets return trampolines look
6327 like subroutine calls (MIPS16 return thunks). */
6328 if (gdbarch_in_solib_return_trampoline (gdbarch,
6329 stop_pc, ecs->stop_func_name)
6330 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6332 /* Determine where this trampoline returns. */
6333 CORE_ADDR real_stop_pc;
6335 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6338 fprintf_unfiltered (gdb_stdlog,
6339 "infrun: stepped into solib return tramp\n");
6341 /* Only proceed through if we know where it's going. */
6344 /* And put the step-breakpoint there and go until there. */
6345 struct symtab_and_line sr_sal;
6347 init_sal (&sr_sal); /* initialize to zeroes */
6348 sr_sal.pc = real_stop_pc;
6349 sr_sal.section = find_pc_overlay (sr_sal.pc);
6350 sr_sal.pspace = get_frame_program_space (frame);
6352 /* Do not specify what the fp should be when we stop since
6353 on some machines the prologue is where the new fp value
6355 insert_step_resume_breakpoint_at_sal (gdbarch,
6356 sr_sal, null_frame_id);
6358 /* Restart without fiddling with the step ranges or
6365 /* Check for subroutine calls. The check for the current frame
6366 equalling the step ID is not necessary - the check of the
6367 previous frame's ID is sufficient - but it is a common case and
6368 cheaper than checking the previous frame's ID.
6370 NOTE: frame_id_eq will never report two invalid frame IDs as
6371 being equal, so to get into this block, both the current and
6372 previous frame must have valid frame IDs. */
6373 /* The outer_frame_id check is a heuristic to detect stepping
6374 through startup code. If we step over an instruction which
6375 sets the stack pointer from an invalid value to a valid value,
6376 we may detect that as a subroutine call from the mythical
6377 "outermost" function. This could be fixed by marking
6378 outermost frames as !stack_p,code_p,special_p. Then the
6379 initial outermost frame, before sp was valid, would
6380 have code_addr == &_start. See the comment in frame_id_eq
6382 if (!frame_id_eq (get_stack_frame_id (frame),
6383 ecs->event_thread->control.step_stack_frame_id)
6384 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6385 ecs->event_thread->control.step_stack_frame_id)
6386 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6388 || (ecs->event_thread->control.step_start_function
6389 != find_pc_function (stop_pc)))))
6391 CORE_ADDR real_stop_pc;
6394 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6396 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6398 /* I presume that step_over_calls is only 0 when we're
6399 supposed to be stepping at the assembly language level
6400 ("stepi"). Just stop. */
6401 /* And this works the same backward as frontward. MVS */
6402 end_stepping_range (ecs);
6406 /* Reverse stepping through solib trampolines. */
6408 if (execution_direction == EXEC_REVERSE
6409 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6410 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6411 || (ecs->stop_func_start == 0
6412 && in_solib_dynsym_resolve_code (stop_pc))))
6414 /* Any solib trampoline code can be handled in reverse
6415 by simply continuing to single-step. We have already
6416 executed the solib function (backwards), and a few
6417 steps will take us back through the trampoline to the
6423 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6425 /* We're doing a "next".
6427 Normal (forward) execution: set a breakpoint at the
6428 callee's return address (the address at which the caller
6431 Reverse (backward) execution. set the step-resume
6432 breakpoint at the start of the function that we just
6433 stepped into (backwards), and continue to there. When we
6434 get there, we'll need to single-step back to the caller. */
6436 if (execution_direction == EXEC_REVERSE)
6438 /* If we're already at the start of the function, we've either
6439 just stepped backward into a single instruction function,
6440 or stepped back out of a signal handler to the first instruction
6441 of the function. Just keep going, which will single-step back
6443 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6445 struct symtab_and_line sr_sal;
6447 /* Normal function call return (static or dynamic). */
6449 sr_sal.pc = ecs->stop_func_start;
6450 sr_sal.pspace = get_frame_program_space (frame);
6451 insert_step_resume_breakpoint_at_sal (gdbarch,
6452 sr_sal, null_frame_id);
6456 insert_step_resume_breakpoint_at_caller (frame);
6462 /* If we are in a function call trampoline (a stub between the
6463 calling routine and the real function), locate the real
6464 function. That's what tells us (a) whether we want to step
6465 into it at all, and (b) what prologue we want to run to the
6466 end of, if we do step into it. */
6467 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6468 if (real_stop_pc == 0)
6469 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6470 if (real_stop_pc != 0)
6471 ecs->stop_func_start = real_stop_pc;
6473 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6475 struct symtab_and_line sr_sal;
6478 sr_sal.pc = ecs->stop_func_start;
6479 sr_sal.pspace = get_frame_program_space (frame);
6481 insert_step_resume_breakpoint_at_sal (gdbarch,
6482 sr_sal, null_frame_id);
6487 /* If we have line number information for the function we are
6488 thinking of stepping into and the function isn't on the skip
6491 If there are several symtabs at that PC (e.g. with include
6492 files), just want to know whether *any* of them have line
6493 numbers. find_pc_line handles this. */
6495 struct symtab_and_line tmp_sal;
6497 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6498 if (tmp_sal.line != 0
6499 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6502 if (execution_direction == EXEC_REVERSE)
6503 handle_step_into_function_backward (gdbarch, ecs);
6505 handle_step_into_function (gdbarch, ecs);
6510 /* If we have no line number and the step-stop-if-no-debug is
6511 set, we stop the step so that the user has a chance to switch
6512 in assembly mode. */
6513 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6514 && step_stop_if_no_debug)
6516 end_stepping_range (ecs);
6520 if (execution_direction == EXEC_REVERSE)
6522 /* If we're already at the start of the function, we've either just
6523 stepped backward into a single instruction function without line
6524 number info, or stepped back out of a signal handler to the first
6525 instruction of the function without line number info. Just keep
6526 going, which will single-step back to the caller. */
6527 if (ecs->stop_func_start != stop_pc)
6529 /* Set a breakpoint at callee's start address.
6530 From there we can step once and be back in the caller. */
6531 struct symtab_and_line sr_sal;
6534 sr_sal.pc = ecs->stop_func_start;
6535 sr_sal.pspace = get_frame_program_space (frame);
6536 insert_step_resume_breakpoint_at_sal (gdbarch,
6537 sr_sal, null_frame_id);
6541 /* Set a breakpoint at callee's return address (the address
6542 at which the caller will resume). */
6543 insert_step_resume_breakpoint_at_caller (frame);
6549 /* Reverse stepping through solib trampolines. */
6551 if (execution_direction == EXEC_REVERSE
6552 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6554 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6555 || (ecs->stop_func_start == 0
6556 && in_solib_dynsym_resolve_code (stop_pc)))
6558 /* Any solib trampoline code can be handled in reverse
6559 by simply continuing to single-step. We have already
6560 executed the solib function (backwards), and a few
6561 steps will take us back through the trampoline to the
6566 else if (in_solib_dynsym_resolve_code (stop_pc))
6568 /* Stepped backward into the solib dynsym resolver.
6569 Set a breakpoint at its start and continue, then
6570 one more step will take us out. */
6571 struct symtab_and_line sr_sal;
6574 sr_sal.pc = ecs->stop_func_start;
6575 sr_sal.pspace = get_frame_program_space (frame);
6576 insert_step_resume_breakpoint_at_sal (gdbarch,
6577 sr_sal, null_frame_id);
6583 stop_pc_sal = find_pc_line (stop_pc, 0);
6585 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6586 the trampoline processing logic, however, there are some trampolines
6587 that have no names, so we should do trampoline handling first. */
6588 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6589 && ecs->stop_func_name == NULL
6590 && stop_pc_sal.line == 0)
6593 fprintf_unfiltered (gdb_stdlog,
6594 "infrun: stepped into undebuggable function\n");
6596 /* The inferior just stepped into, or returned to, an
6597 undebuggable function (where there is no debugging information
6598 and no line number corresponding to the address where the
6599 inferior stopped). Since we want to skip this kind of code,
6600 we keep going until the inferior returns from this
6601 function - unless the user has asked us not to (via
6602 set step-mode) or we no longer know how to get back
6603 to the call site. */
6604 if (step_stop_if_no_debug
6605 || !frame_id_p (frame_unwind_caller_id (frame)))
6607 /* If we have no line number and the step-stop-if-no-debug
6608 is set, we stop the step so that the user has a chance to
6609 switch in assembly mode. */
6610 end_stepping_range (ecs);
6615 /* Set a breakpoint at callee's return address (the address
6616 at which the caller will resume). */
6617 insert_step_resume_breakpoint_at_caller (frame);
6623 if (ecs->event_thread->control.step_range_end == 1)
6625 /* It is stepi or nexti. We always want to stop stepping after
6628 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6629 end_stepping_range (ecs);
6633 if (stop_pc_sal.line == 0)
6635 /* We have no line number information. That means to stop
6636 stepping (does this always happen right after one instruction,
6637 when we do "s" in a function with no line numbers,
6638 or can this happen as a result of a return or longjmp?). */
6640 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6641 end_stepping_range (ecs);
6645 /* Look for "calls" to inlined functions, part one. If the inline
6646 frame machinery detected some skipped call sites, we have entered
6647 a new inline function. */
6649 if (frame_id_eq (get_frame_id (get_current_frame ()),
6650 ecs->event_thread->control.step_frame_id)
6651 && inline_skipped_frames (ecs->ptid))
6653 struct symtab_and_line call_sal;
6656 fprintf_unfiltered (gdb_stdlog,
6657 "infrun: stepped into inlined function\n");
6659 find_frame_sal (get_current_frame (), &call_sal);
6661 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6663 /* For "step", we're going to stop. But if the call site
6664 for this inlined function is on the same source line as
6665 we were previously stepping, go down into the function
6666 first. Otherwise stop at the call site. */
6668 if (call_sal.line == ecs->event_thread->current_line
6669 && call_sal.symtab == ecs->event_thread->current_symtab)
6670 step_into_inline_frame (ecs->ptid);
6672 end_stepping_range (ecs);
6677 /* For "next", we should stop at the call site if it is on a
6678 different source line. Otherwise continue through the
6679 inlined function. */
6680 if (call_sal.line == ecs->event_thread->current_line
6681 && call_sal.symtab == ecs->event_thread->current_symtab)
6684 end_stepping_range (ecs);
6689 /* Look for "calls" to inlined functions, part two. If we are still
6690 in the same real function we were stepping through, but we have
6691 to go further up to find the exact frame ID, we are stepping
6692 through a more inlined call beyond its call site. */
6694 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6695 && !frame_id_eq (get_frame_id (get_current_frame ()),
6696 ecs->event_thread->control.step_frame_id)
6697 && stepped_in_from (get_current_frame (),
6698 ecs->event_thread->control.step_frame_id))
6701 fprintf_unfiltered (gdb_stdlog,
6702 "infrun: stepping through inlined function\n");
6704 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6707 end_stepping_range (ecs);
6711 if ((stop_pc == stop_pc_sal.pc)
6712 && (ecs->event_thread->current_line != stop_pc_sal.line
6713 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6715 /* We are at the start of a different line. So stop. Note that
6716 we don't stop if we step into the middle of a different line.
6717 That is said to make things like for (;;) statements work
6720 fprintf_unfiltered (gdb_stdlog,
6721 "infrun: stepped to a different line\n");
6722 end_stepping_range (ecs);
6726 /* We aren't done stepping.
6728 Optimize by setting the stepping range to the line.
6729 (We might not be in the original line, but if we entered a
6730 new line in mid-statement, we continue stepping. This makes
6731 things like for(;;) statements work better.) */
6733 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6734 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6735 ecs->event_thread->control.may_range_step = 1;
6736 set_step_info (frame, stop_pc_sal);
6739 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6743 /* In all-stop mode, if we're currently stepping but have stopped in
6744 some other thread, we may need to switch back to the stepped
6745 thread. Returns true we set the inferior running, false if we left
6746 it stopped (and the event needs further processing). */
6749 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6751 if (!target_is_non_stop_p ())
6753 struct thread_info *tp;
6754 struct thread_info *stepping_thread;
6756 /* If any thread is blocked on some internal breakpoint, and we
6757 simply need to step over that breakpoint to get it going
6758 again, do that first. */
6760 /* However, if we see an event for the stepping thread, then we
6761 know all other threads have been moved past their breakpoints
6762 already. Let the caller check whether the step is finished,
6763 etc., before deciding to move it past a breakpoint. */
6764 if (ecs->event_thread->control.step_range_end != 0)
6767 /* Check if the current thread is blocked on an incomplete
6768 step-over, interrupted by a random signal. */
6769 if (ecs->event_thread->control.trap_expected
6770 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6774 fprintf_unfiltered (gdb_stdlog,
6775 "infrun: need to finish step-over of [%s]\n",
6776 target_pid_to_str (ecs->event_thread->ptid));
6782 /* Check if the current thread is blocked by a single-step
6783 breakpoint of another thread. */
6784 if (ecs->hit_singlestep_breakpoint)
6788 fprintf_unfiltered (gdb_stdlog,
6789 "infrun: need to step [%s] over single-step "
6791 target_pid_to_str (ecs->ptid));
6797 /* If this thread needs yet another step-over (e.g., stepping
6798 through a delay slot), do it first before moving on to
6800 if (thread_still_needs_step_over (ecs->event_thread))
6804 fprintf_unfiltered (gdb_stdlog,
6805 "infrun: thread [%s] still needs step-over\n",
6806 target_pid_to_str (ecs->event_thread->ptid));
6812 /* If scheduler locking applies even if not stepping, there's no
6813 need to walk over threads. Above we've checked whether the
6814 current thread is stepping. If some other thread not the
6815 event thread is stepping, then it must be that scheduler
6816 locking is not in effect. */
6817 if (schedlock_applies (ecs->event_thread))
6820 /* Otherwise, we no longer expect a trap in the current thread.
6821 Clear the trap_expected flag before switching back -- this is
6822 what keep_going does as well, if we call it. */
6823 ecs->event_thread->control.trap_expected = 0;
6825 /* Likewise, clear the signal if it should not be passed. */
6826 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6827 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6829 /* Do all pending step-overs before actually proceeding with
6831 if (start_step_over ())
6833 prepare_to_wait (ecs);
6837 /* Look for the stepping/nexting thread. */
6838 stepping_thread = NULL;
6840 ALL_NON_EXITED_THREADS (tp)
6842 /* Ignore threads of processes the caller is not
6845 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
6848 /* When stepping over a breakpoint, we lock all threads
6849 except the one that needs to move past the breakpoint.
6850 If a non-event thread has this set, the "incomplete
6851 step-over" check above should have caught it earlier. */
6852 if (tp->control.trap_expected)
6854 internal_error (__FILE__, __LINE__,
6855 "[%s] has inconsistent state: "
6856 "trap_expected=%d\n",
6857 target_pid_to_str (tp->ptid),
6858 tp->control.trap_expected);
6861 /* Did we find the stepping thread? */
6862 if (tp->control.step_range_end)
6864 /* Yep. There should only one though. */
6865 gdb_assert (stepping_thread == NULL);
6867 /* The event thread is handled at the top, before we
6869 gdb_assert (tp != ecs->event_thread);
6871 /* If some thread other than the event thread is
6872 stepping, then scheduler locking can't be in effect,
6873 otherwise we wouldn't have resumed the current event
6874 thread in the first place. */
6875 gdb_assert (!schedlock_applies (tp));
6877 stepping_thread = tp;
6881 if (stepping_thread != NULL)
6884 fprintf_unfiltered (gdb_stdlog,
6885 "infrun: switching back to stepped thread\n");
6887 if (keep_going_stepped_thread (stepping_thread))
6889 prepare_to_wait (ecs);
6898 /* Set a previously stepped thread back to stepping. Returns true on
6899 success, false if the resume is not possible (e.g., the thread
6903 keep_going_stepped_thread (struct thread_info *tp)
6905 struct frame_info *frame;
6906 struct gdbarch *gdbarch;
6907 struct execution_control_state ecss;
6908 struct execution_control_state *ecs = &ecss;
6910 /* If the stepping thread exited, then don't try to switch back and
6911 resume it, which could fail in several different ways depending
6912 on the target. Instead, just keep going.
6914 We can find a stepping dead thread in the thread list in two
6917 - The target supports thread exit events, and when the target
6918 tries to delete the thread from the thread list, inferior_ptid
6919 pointed at the exiting thread. In such case, calling
6920 delete_thread does not really remove the thread from the list;
6921 instead, the thread is left listed, with 'exited' state.
6923 - The target's debug interface does not support thread exit
6924 events, and so we have no idea whatsoever if the previously
6925 stepping thread is still alive. For that reason, we need to
6926 synchronously query the target now. */
6928 if (is_exited (tp->ptid)
6929 || !target_thread_alive (tp->ptid))
6932 fprintf_unfiltered (gdb_stdlog,
6933 "infrun: not resuming previously "
6934 "stepped thread, it has vanished\n");
6936 delete_thread (tp->ptid);
6941 fprintf_unfiltered (gdb_stdlog,
6942 "infrun: resuming previously stepped thread\n");
6944 reset_ecs (ecs, tp);
6945 switch_to_thread (tp->ptid);
6947 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
6948 frame = get_current_frame ();
6949 gdbarch = get_frame_arch (frame);
6951 /* If the PC of the thread we were trying to single-step has
6952 changed, then that thread has trapped or been signaled, but the
6953 event has not been reported to GDB yet. Re-poll the target
6954 looking for this particular thread's event (i.e. temporarily
6955 enable schedlock) by:
6957 - setting a break at the current PC
6958 - resuming that particular thread, only (by setting trap
6961 This prevents us continuously moving the single-step breakpoint
6962 forward, one instruction at a time, overstepping. */
6964 if (stop_pc != tp->prev_pc)
6969 fprintf_unfiltered (gdb_stdlog,
6970 "infrun: expected thread advanced also (%s -> %s)\n",
6971 paddress (target_gdbarch (), tp->prev_pc),
6972 paddress (target_gdbarch (), stop_pc));
6974 /* Clear the info of the previous step-over, as it's no longer
6975 valid (if the thread was trying to step over a breakpoint, it
6976 has already succeeded). It's what keep_going would do too,
6977 if we called it. Do this before trying to insert the sss
6978 breakpoint, otherwise if we were previously trying to step
6979 over this exact address in another thread, the breakpoint is
6981 clear_step_over_info ();
6982 tp->control.trap_expected = 0;
6984 insert_single_step_breakpoint (get_frame_arch (frame),
6985 get_frame_address_space (frame),
6989 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
6990 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
6995 fprintf_unfiltered (gdb_stdlog,
6996 "infrun: expected thread still hasn't advanced\n");
6998 keep_going_pass_signal (ecs);
7003 /* Is thread TP in the middle of (software or hardware)
7004 single-stepping? (Note the result of this function must never be
7005 passed directly as target_resume's STEP parameter.) */
7008 currently_stepping (struct thread_info *tp)
7010 return ((tp->control.step_range_end
7011 && tp->control.step_resume_breakpoint == NULL)
7012 || tp->control.trap_expected
7013 || tp->stepped_breakpoint
7014 || bpstat_should_step ());
7017 /* Inferior has stepped into a subroutine call with source code that
7018 we should not step over. Do step to the first line of code in
7022 handle_step_into_function (struct gdbarch *gdbarch,
7023 struct execution_control_state *ecs)
7025 struct compunit_symtab *cust;
7026 struct symtab_and_line stop_func_sal, sr_sal;
7028 fill_in_stop_func (gdbarch, ecs);
7030 cust = find_pc_compunit_symtab (stop_pc);
7031 if (cust != NULL && compunit_language (cust) != language_asm)
7032 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7033 ecs->stop_func_start);
7035 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7036 /* Use the step_resume_break to step until the end of the prologue,
7037 even if that involves jumps (as it seems to on the vax under
7039 /* If the prologue ends in the middle of a source line, continue to
7040 the end of that source line (if it is still within the function).
7041 Otherwise, just go to end of prologue. */
7042 if (stop_func_sal.end
7043 && stop_func_sal.pc != ecs->stop_func_start
7044 && stop_func_sal.end < ecs->stop_func_end)
7045 ecs->stop_func_start = stop_func_sal.end;
7047 /* Architectures which require breakpoint adjustment might not be able
7048 to place a breakpoint at the computed address. If so, the test
7049 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7050 ecs->stop_func_start to an address at which a breakpoint may be
7051 legitimately placed.
7053 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7054 made, GDB will enter an infinite loop when stepping through
7055 optimized code consisting of VLIW instructions which contain
7056 subinstructions corresponding to different source lines. On
7057 FR-V, it's not permitted to place a breakpoint on any but the
7058 first subinstruction of a VLIW instruction. When a breakpoint is
7059 set, GDB will adjust the breakpoint address to the beginning of
7060 the VLIW instruction. Thus, we need to make the corresponding
7061 adjustment here when computing the stop address. */
7063 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7065 ecs->stop_func_start
7066 = gdbarch_adjust_breakpoint_address (gdbarch,
7067 ecs->stop_func_start);
7070 if (ecs->stop_func_start == stop_pc)
7072 /* We are already there: stop now. */
7073 end_stepping_range (ecs);
7078 /* Put the step-breakpoint there and go until there. */
7079 init_sal (&sr_sal); /* initialize to zeroes */
7080 sr_sal.pc = ecs->stop_func_start;
7081 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7082 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7084 /* Do not specify what the fp should be when we stop since on
7085 some machines the prologue is where the new fp value is
7087 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7089 /* And make sure stepping stops right away then. */
7090 ecs->event_thread->control.step_range_end
7091 = ecs->event_thread->control.step_range_start;
7096 /* Inferior has stepped backward into a subroutine call with source
7097 code that we should not step over. Do step to the beginning of the
7098 last line of code in it. */
7101 handle_step_into_function_backward (struct gdbarch *gdbarch,
7102 struct execution_control_state *ecs)
7104 struct compunit_symtab *cust;
7105 struct symtab_and_line stop_func_sal;
7107 fill_in_stop_func (gdbarch, ecs);
7109 cust = find_pc_compunit_symtab (stop_pc);
7110 if (cust != NULL && compunit_language (cust) != language_asm)
7111 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7112 ecs->stop_func_start);
7114 stop_func_sal = find_pc_line (stop_pc, 0);
7116 /* OK, we're just going to keep stepping here. */
7117 if (stop_func_sal.pc == stop_pc)
7119 /* We're there already. Just stop stepping now. */
7120 end_stepping_range (ecs);
7124 /* Else just reset the step range and keep going.
7125 No step-resume breakpoint, they don't work for
7126 epilogues, which can have multiple entry paths. */
7127 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7128 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7134 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7135 This is used to both functions and to skip over code. */
7138 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7139 struct symtab_and_line sr_sal,
7140 struct frame_id sr_id,
7141 enum bptype sr_type)
7143 /* There should never be more than one step-resume or longjmp-resume
7144 breakpoint per thread, so we should never be setting a new
7145 step_resume_breakpoint when one is already active. */
7146 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7147 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7150 fprintf_unfiltered (gdb_stdlog,
7151 "infrun: inserting step-resume breakpoint at %s\n",
7152 paddress (gdbarch, sr_sal.pc));
7154 inferior_thread ()->control.step_resume_breakpoint
7155 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7159 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7160 struct symtab_and_line sr_sal,
7161 struct frame_id sr_id)
7163 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7168 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7169 This is used to skip a potential signal handler.
7171 This is called with the interrupted function's frame. The signal
7172 handler, when it returns, will resume the interrupted function at
7176 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7178 struct symtab_and_line sr_sal;
7179 struct gdbarch *gdbarch;
7181 gdb_assert (return_frame != NULL);
7182 init_sal (&sr_sal); /* initialize to zeros */
7184 gdbarch = get_frame_arch (return_frame);
7185 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7186 sr_sal.section = find_pc_overlay (sr_sal.pc);
7187 sr_sal.pspace = get_frame_program_space (return_frame);
7189 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7190 get_stack_frame_id (return_frame),
7194 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7195 is used to skip a function after stepping into it (for "next" or if
7196 the called function has no debugging information).
7198 The current function has almost always been reached by single
7199 stepping a call or return instruction. NEXT_FRAME belongs to the
7200 current function, and the breakpoint will be set at the caller's
7203 This is a separate function rather than reusing
7204 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7205 get_prev_frame, which may stop prematurely (see the implementation
7206 of frame_unwind_caller_id for an example). */
7209 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7211 struct symtab_and_line sr_sal;
7212 struct gdbarch *gdbarch;
7214 /* We shouldn't have gotten here if we don't know where the call site
7216 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7218 init_sal (&sr_sal); /* initialize to zeros */
7220 gdbarch = frame_unwind_caller_arch (next_frame);
7221 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7222 frame_unwind_caller_pc (next_frame));
7223 sr_sal.section = find_pc_overlay (sr_sal.pc);
7224 sr_sal.pspace = frame_unwind_program_space (next_frame);
7226 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7227 frame_unwind_caller_id (next_frame));
7230 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7231 new breakpoint at the target of a jmp_buf. The handling of
7232 longjmp-resume uses the same mechanisms used for handling
7233 "step-resume" breakpoints. */
7236 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7238 /* There should never be more than one longjmp-resume breakpoint per
7239 thread, so we should never be setting a new
7240 longjmp_resume_breakpoint when one is already active. */
7241 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7244 fprintf_unfiltered (gdb_stdlog,
7245 "infrun: inserting longjmp-resume breakpoint at %s\n",
7246 paddress (gdbarch, pc));
7248 inferior_thread ()->control.exception_resume_breakpoint =
7249 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7252 /* Insert an exception resume breakpoint. TP is the thread throwing
7253 the exception. The block B is the block of the unwinder debug hook
7254 function. FRAME is the frame corresponding to the call to this
7255 function. SYM is the symbol of the function argument holding the
7256 target PC of the exception. */
7259 insert_exception_resume_breakpoint (struct thread_info *tp,
7260 const struct block *b,
7261 struct frame_info *frame,
7266 struct block_symbol vsym;
7267 struct value *value;
7269 struct breakpoint *bp;
7271 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7272 value = read_var_value (vsym.symbol, vsym.block, frame);
7273 /* If the value was optimized out, revert to the old behavior. */
7274 if (! value_optimized_out (value))
7276 handler = value_as_address (value);
7279 fprintf_unfiltered (gdb_stdlog,
7280 "infrun: exception resume at %lx\n",
7281 (unsigned long) handler);
7283 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7284 handler, bp_exception_resume);
7286 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7289 bp->thread = tp->num;
7290 inferior_thread ()->control.exception_resume_breakpoint = bp;
7293 CATCH (e, RETURN_MASK_ERROR)
7295 /* We want to ignore errors here. */
7300 /* A helper for check_exception_resume that sets an
7301 exception-breakpoint based on a SystemTap probe. */
7304 insert_exception_resume_from_probe (struct thread_info *tp,
7305 const struct bound_probe *probe,
7306 struct frame_info *frame)
7308 struct value *arg_value;
7310 struct breakpoint *bp;
7312 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7316 handler = value_as_address (arg_value);
7319 fprintf_unfiltered (gdb_stdlog,
7320 "infrun: exception resume at %s\n",
7321 paddress (get_objfile_arch (probe->objfile),
7324 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7325 handler, bp_exception_resume);
7326 bp->thread = tp->num;
7327 inferior_thread ()->control.exception_resume_breakpoint = bp;
7330 /* This is called when an exception has been intercepted. Check to
7331 see whether the exception's destination is of interest, and if so,
7332 set an exception resume breakpoint there. */
7335 check_exception_resume (struct execution_control_state *ecs,
7336 struct frame_info *frame)
7338 struct bound_probe probe;
7339 struct symbol *func;
7341 /* First see if this exception unwinding breakpoint was set via a
7342 SystemTap probe point. If so, the probe has two arguments: the
7343 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7344 set a breakpoint there. */
7345 probe = find_probe_by_pc (get_frame_pc (frame));
7348 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7352 func = get_frame_function (frame);
7358 const struct block *b;
7359 struct block_iterator iter;
7363 /* The exception breakpoint is a thread-specific breakpoint on
7364 the unwinder's debug hook, declared as:
7366 void _Unwind_DebugHook (void *cfa, void *handler);
7368 The CFA argument indicates the frame to which control is
7369 about to be transferred. HANDLER is the destination PC.
7371 We ignore the CFA and set a temporary breakpoint at HANDLER.
7372 This is not extremely efficient but it avoids issues in gdb
7373 with computing the DWARF CFA, and it also works even in weird
7374 cases such as throwing an exception from inside a signal
7377 b = SYMBOL_BLOCK_VALUE (func);
7378 ALL_BLOCK_SYMBOLS (b, iter, sym)
7380 if (!SYMBOL_IS_ARGUMENT (sym))
7387 insert_exception_resume_breakpoint (ecs->event_thread,
7393 CATCH (e, RETURN_MASK_ERROR)
7400 stop_waiting (struct execution_control_state *ecs)
7403 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7405 clear_step_over_info ();
7407 /* Let callers know we don't want to wait for the inferior anymore. */
7408 ecs->wait_some_more = 0;
7410 /* If all-stop, but the target is always in non-stop mode, stop all
7411 threads now that we're presenting the stop to the user. */
7412 if (!non_stop && target_is_non_stop_p ())
7413 stop_all_threads ();
7416 /* Like keep_going, but passes the signal to the inferior, even if the
7417 signal is set to nopass. */
7420 keep_going_pass_signal (struct execution_control_state *ecs)
7422 /* Make sure normal_stop is called if we get a QUIT handled before
7424 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7426 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7427 gdb_assert (!ecs->event_thread->resumed);
7429 /* Save the pc before execution, to compare with pc after stop. */
7430 ecs->event_thread->prev_pc
7431 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7433 if (ecs->event_thread->control.trap_expected)
7435 struct thread_info *tp = ecs->event_thread;
7438 fprintf_unfiltered (gdb_stdlog,
7439 "infrun: %s has trap_expected set, "
7440 "resuming to collect trap\n",
7441 target_pid_to_str (tp->ptid));
7443 /* We haven't yet gotten our trap, and either: intercepted a
7444 non-signal event (e.g., a fork); or took a signal which we
7445 are supposed to pass through to the inferior. Simply
7447 discard_cleanups (old_cleanups);
7448 resume (ecs->event_thread->suspend.stop_signal);
7450 else if (step_over_info_valid_p ())
7452 /* Another thread is stepping over a breakpoint in-line. If
7453 this thread needs a step-over too, queue the request. In
7454 either case, this resume must be deferred for later. */
7455 struct thread_info *tp = ecs->event_thread;
7457 if (ecs->hit_singlestep_breakpoint
7458 || thread_still_needs_step_over (tp))
7461 fprintf_unfiltered (gdb_stdlog,
7462 "infrun: step-over already in progress: "
7463 "step-over for %s deferred\n",
7464 target_pid_to_str (tp->ptid));
7465 thread_step_over_chain_enqueue (tp);
7470 fprintf_unfiltered (gdb_stdlog,
7471 "infrun: step-over in progress: "
7472 "resume of %s deferred\n",
7473 target_pid_to_str (tp->ptid));
7476 discard_cleanups (old_cleanups);
7480 struct regcache *regcache = get_current_regcache ();
7483 enum step_over_what step_what;
7485 /* Either the trap was not expected, but we are continuing
7486 anyway (if we got a signal, the user asked it be passed to
7489 We got our expected trap, but decided we should resume from
7492 We're going to run this baby now!
7494 Note that insert_breakpoints won't try to re-insert
7495 already inserted breakpoints. Therefore, we don't
7496 care if breakpoints were already inserted, or not. */
7498 /* If we need to step over a breakpoint, and we're not using
7499 displaced stepping to do so, insert all breakpoints
7500 (watchpoints, etc.) but the one we're stepping over, step one
7501 instruction, and then re-insert the breakpoint when that step
7504 step_what = thread_still_needs_step_over (ecs->event_thread);
7506 remove_bp = (ecs->hit_singlestep_breakpoint
7507 || (step_what & STEP_OVER_BREAKPOINT));
7508 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7510 /* We can't use displaced stepping if we need to step past a
7511 watchpoint. The instruction copied to the scratch pad would
7512 still trigger the watchpoint. */
7514 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7516 set_step_over_info (get_regcache_aspace (regcache),
7517 regcache_read_pc (regcache), remove_wps);
7519 else if (remove_wps)
7520 set_step_over_info (NULL, 0, remove_wps);
7522 /* If we now need to do an in-line step-over, we need to stop
7523 all other threads. Note this must be done before
7524 insert_breakpoints below, because that removes the breakpoint
7525 we're about to step over, otherwise other threads could miss
7527 if (step_over_info_valid_p () && target_is_non_stop_p ())
7528 stop_all_threads ();
7530 /* Stop stepping if inserting breakpoints fails. */
7533 insert_breakpoints ();
7535 CATCH (e, RETURN_MASK_ERROR)
7537 exception_print (gdb_stderr, e);
7539 discard_cleanups (old_cleanups);
7544 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7546 discard_cleanups (old_cleanups);
7547 resume (ecs->event_thread->suspend.stop_signal);
7550 prepare_to_wait (ecs);
7553 /* Called when we should continue running the inferior, because the
7554 current event doesn't cause a user visible stop. This does the
7555 resuming part; waiting for the next event is done elsewhere. */
7558 keep_going (struct execution_control_state *ecs)
7560 if (ecs->event_thread->control.trap_expected
7561 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7562 ecs->event_thread->control.trap_expected = 0;
7564 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7565 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7566 keep_going_pass_signal (ecs);
7569 /* This function normally comes after a resume, before
7570 handle_inferior_event exits. It takes care of any last bits of
7571 housekeeping, and sets the all-important wait_some_more flag. */
7574 prepare_to_wait (struct execution_control_state *ecs)
7577 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7579 ecs->wait_some_more = 1;
7581 if (!target_is_async_p ())
7582 mark_infrun_async_event_handler ();
7585 /* We are done with the step range of a step/next/si/ni command.
7586 Called once for each n of a "step n" operation. */
7589 end_stepping_range (struct execution_control_state *ecs)
7591 ecs->event_thread->control.stop_step = 1;
7595 /* Several print_*_reason functions to print why the inferior has stopped.
7596 We always print something when the inferior exits, or receives a signal.
7597 The rest of the cases are dealt with later on in normal_stop and
7598 print_it_typical. Ideally there should be a call to one of these
7599 print_*_reason functions functions from handle_inferior_event each time
7600 stop_waiting is called.
7602 Note that we don't call these directly, instead we delegate that to
7603 the interpreters, through observers. Interpreters then call these
7604 with whatever uiout is right. */
7607 print_end_stepping_range_reason (struct ui_out *uiout)
7609 /* For CLI-like interpreters, print nothing. */
7611 if (ui_out_is_mi_like_p (uiout))
7613 ui_out_field_string (uiout, "reason",
7614 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7619 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7621 annotate_signalled ();
7622 if (ui_out_is_mi_like_p (uiout))
7624 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7625 ui_out_text (uiout, "\nProgram terminated with signal ");
7626 annotate_signal_name ();
7627 ui_out_field_string (uiout, "signal-name",
7628 gdb_signal_to_name (siggnal));
7629 annotate_signal_name_end ();
7630 ui_out_text (uiout, ", ");
7631 annotate_signal_string ();
7632 ui_out_field_string (uiout, "signal-meaning",
7633 gdb_signal_to_string (siggnal));
7634 annotate_signal_string_end ();
7635 ui_out_text (uiout, ".\n");
7636 ui_out_text (uiout, "The program no longer exists.\n");
7640 print_exited_reason (struct ui_out *uiout, int exitstatus)
7642 struct inferior *inf = current_inferior ();
7643 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7645 annotate_exited (exitstatus);
7648 if (ui_out_is_mi_like_p (uiout))
7649 ui_out_field_string (uiout, "reason",
7650 async_reason_lookup (EXEC_ASYNC_EXITED));
7651 ui_out_text (uiout, "[Inferior ");
7652 ui_out_text (uiout, plongest (inf->num));
7653 ui_out_text (uiout, " (");
7654 ui_out_text (uiout, pidstr);
7655 ui_out_text (uiout, ") exited with code ");
7656 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
7657 ui_out_text (uiout, "]\n");
7661 if (ui_out_is_mi_like_p (uiout))
7663 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7664 ui_out_text (uiout, "[Inferior ");
7665 ui_out_text (uiout, plongest (inf->num));
7666 ui_out_text (uiout, " (");
7667 ui_out_text (uiout, pidstr);
7668 ui_out_text (uiout, ") exited normally]\n");
7673 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7677 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
7679 struct thread_info *t = inferior_thread ();
7681 ui_out_text (uiout, "\n[");
7682 ui_out_field_string (uiout, "thread-name",
7683 target_pid_to_str (t->ptid));
7684 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
7685 ui_out_text (uiout, " stopped");
7689 ui_out_text (uiout, "\nProgram received signal ");
7690 annotate_signal_name ();
7691 if (ui_out_is_mi_like_p (uiout))
7693 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7694 ui_out_field_string (uiout, "signal-name",
7695 gdb_signal_to_name (siggnal));
7696 annotate_signal_name_end ();
7697 ui_out_text (uiout, ", ");
7698 annotate_signal_string ();
7699 ui_out_field_string (uiout, "signal-meaning",
7700 gdb_signal_to_string (siggnal));
7701 annotate_signal_string_end ();
7703 ui_out_text (uiout, ".\n");
7707 print_no_history_reason (struct ui_out *uiout)
7709 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
7712 /* Print current location without a level number, if we have changed
7713 functions or hit a breakpoint. Print source line if we have one.
7714 bpstat_print contains the logic deciding in detail what to print,
7715 based on the event(s) that just occurred. */
7718 print_stop_location (struct target_waitstatus *ws)
7721 enum print_what source_flag;
7722 int do_frame_printing = 1;
7723 struct thread_info *tp = inferior_thread ();
7725 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7729 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7730 should) carry around the function and does (or should) use
7731 that when doing a frame comparison. */
7732 if (tp->control.stop_step
7733 && frame_id_eq (tp->control.step_frame_id,
7734 get_frame_id (get_current_frame ()))
7735 && tp->control.step_start_function == find_pc_function (stop_pc))
7737 /* Finished step, just print source line. */
7738 source_flag = SRC_LINE;
7742 /* Print location and source line. */
7743 source_flag = SRC_AND_LOC;
7746 case PRINT_SRC_AND_LOC:
7747 /* Print location and source line. */
7748 source_flag = SRC_AND_LOC;
7750 case PRINT_SRC_ONLY:
7751 source_flag = SRC_LINE;
7754 /* Something bogus. */
7755 source_flag = SRC_LINE;
7756 do_frame_printing = 0;
7759 internal_error (__FILE__, __LINE__, _("Unknown value."));
7762 /* The behavior of this routine with respect to the source
7764 SRC_LINE: Print only source line
7765 LOCATION: Print only location
7766 SRC_AND_LOC: Print location and source line. */
7767 if (do_frame_printing)
7768 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7771 /* Cleanup that restores a previous current uiout. */
7774 restore_current_uiout_cleanup (void *arg)
7776 struct ui_out *saved_uiout = arg;
7778 current_uiout = saved_uiout;
7784 print_stop_event (struct ui_out *uiout)
7786 struct cleanup *old_chain;
7787 struct target_waitstatus last;
7789 struct thread_info *tp;
7791 get_last_target_status (&last_ptid, &last);
7793 old_chain = make_cleanup (restore_current_uiout_cleanup, current_uiout);
7794 current_uiout = uiout;
7796 print_stop_location (&last);
7798 /* Display the auto-display expressions. */
7801 do_cleanups (old_chain);
7803 tp = inferior_thread ();
7804 if (tp->thread_fsm != NULL
7805 && thread_fsm_finished_p (tp->thread_fsm))
7807 struct return_value_info *rv;
7809 rv = thread_fsm_return_value (tp->thread_fsm);
7811 print_return_value (uiout, rv);
7818 maybe_remove_breakpoints (void)
7820 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7822 if (remove_breakpoints ())
7824 target_terminal_ours_for_output ();
7825 printf_filtered (_("Cannot remove breakpoints because "
7826 "program is no longer writable.\nFurther "
7827 "execution is probably impossible.\n"));
7832 /* Here to return control to GDB when the inferior stops for real.
7833 Print appropriate messages, remove breakpoints, give terminal our modes.
7835 STOP_PRINT_FRAME nonzero means print the executing frame
7836 (pc, function, args, file, line number and line text).
7837 BREAKPOINTS_FAILED nonzero means stop was due to error
7838 attempting to insert breakpoints. */
7843 struct target_waitstatus last;
7845 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
7848 get_last_target_status (&last_ptid, &last);
7850 /* If an exception is thrown from this point on, make sure to
7851 propagate GDB's knowledge of the executing state to the
7852 frontend/user running state. A QUIT is an easy exception to see
7853 here, so do this before any filtered output. */
7855 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
7856 else if (last.kind == TARGET_WAITKIND_SIGNALLED
7857 || last.kind == TARGET_WAITKIND_EXITED)
7859 /* On some targets, we may still have live threads in the
7860 inferior when we get a process exit event. E.g., for
7861 "checkpoint", when the current checkpoint/fork exits,
7862 linux-fork.c automatically switches to another fork from
7863 within target_mourn_inferior. */
7864 if (!ptid_equal (inferior_ptid, null_ptid))
7866 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
7867 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
7870 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
7871 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
7873 /* As we're presenting a stop, and potentially removing breakpoints,
7874 update the thread list so we can tell whether there are threads
7875 running on the target. With target remote, for example, we can
7876 only learn about new threads when we explicitly update the thread
7877 list. Do this before notifying the interpreters about signal
7878 stops, end of stepping ranges, etc., so that the "new thread"
7879 output is emitted before e.g., "Program received signal FOO",
7880 instead of after. */
7881 update_thread_list ();
7883 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
7884 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
7886 /* As with the notification of thread events, we want to delay
7887 notifying the user that we've switched thread context until
7888 the inferior actually stops.
7890 There's no point in saying anything if the inferior has exited.
7891 Note that SIGNALLED here means "exited with a signal", not
7892 "received a signal".
7894 Also skip saying anything in non-stop mode. In that mode, as we
7895 don't want GDB to switch threads behind the user's back, to avoid
7896 races where the user is typing a command to apply to thread x,
7897 but GDB switches to thread y before the user finishes entering
7898 the command, fetch_inferior_event installs a cleanup to restore
7899 the current thread back to the thread the user had selected right
7900 after this event is handled, so we're not really switching, only
7901 informing of a stop. */
7903 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
7904 && target_has_execution
7905 && last.kind != TARGET_WAITKIND_SIGNALLED
7906 && last.kind != TARGET_WAITKIND_EXITED
7907 && last.kind != TARGET_WAITKIND_NO_RESUMED)
7909 target_terminal_ours_for_output ();
7910 printf_filtered (_("[Switching to %s]\n"),
7911 target_pid_to_str (inferior_ptid));
7912 annotate_thread_changed ();
7913 previous_inferior_ptid = inferior_ptid;
7916 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
7918 gdb_assert (sync_execution || !target_can_async_p ());
7920 target_terminal_ours_for_output ();
7921 printf_filtered (_("No unwaited-for children left.\n"));
7924 /* Note: this depends on the update_thread_list call above. */
7925 maybe_remove_breakpoints ();
7927 /* If an auto-display called a function and that got a signal,
7928 delete that auto-display to avoid an infinite recursion. */
7930 if (stopped_by_random_signal)
7931 disable_current_display ();
7933 target_terminal_ours ();
7934 async_enable_stdin ();
7936 /* Let the user/frontend see the threads as stopped. */
7937 do_cleanups (old_chain);
7939 /* Select innermost stack frame - i.e., current frame is frame 0,
7940 and current location is based on that. Handle the case where the
7941 dummy call is returning after being stopped. E.g. the dummy call
7942 previously hit a breakpoint. (If the dummy call returns
7943 normally, we won't reach here.) Do this before the stop hook is
7944 run, so that it doesn't get to see the temporary dummy frame,
7945 which is not where we'll present the stop. */
7946 if (has_stack_frames ())
7948 if (stop_stack_dummy == STOP_STACK_DUMMY)
7950 /* Pop the empty frame that contains the stack dummy. This
7951 also restores inferior state prior to the call (struct
7952 infcall_suspend_state). */
7953 struct frame_info *frame = get_current_frame ();
7955 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
7957 /* frame_pop calls reinit_frame_cache as the last thing it
7958 does which means there's now no selected frame. */
7961 select_frame (get_current_frame ());
7963 /* Set the current source location. */
7964 set_current_sal_from_frame (get_current_frame ());
7967 /* Look up the hook_stop and run it (CLI internally handles problem
7968 of stop_command's pre-hook not existing). */
7970 catch_errors (hook_stop_stub, stop_command,
7971 "Error while running hook_stop:\n", RETURN_MASK_ALL);
7973 /* Notify observers about the stop. This is where the interpreters
7974 print the stop event. */
7975 if (!ptid_equal (inferior_ptid, null_ptid))
7976 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
7979 observer_notify_normal_stop (NULL, stop_print_frame);
7981 annotate_stopped ();
7983 if (target_has_execution)
7985 if (last.kind != TARGET_WAITKIND_SIGNALLED
7986 && last.kind != TARGET_WAITKIND_EXITED)
7987 /* Delete the breakpoint we stopped at, if it wants to be deleted.
7988 Delete any breakpoint that is to be deleted at the next stop. */
7989 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
7992 /* Try to get rid of automatically added inferiors that are no
7993 longer needed. Keeping those around slows down things linearly.
7994 Note that this never removes the current inferior. */
7999 hook_stop_stub (void *cmd)
8001 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
8006 signal_stop_state (int signo)
8008 return signal_stop[signo];
8012 signal_print_state (int signo)
8014 return signal_print[signo];
8018 signal_pass_state (int signo)
8020 return signal_program[signo];
8024 signal_cache_update (int signo)
8028 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8029 signal_cache_update (signo);
8034 signal_pass[signo] = (signal_stop[signo] == 0
8035 && signal_print[signo] == 0
8036 && signal_program[signo] == 1
8037 && signal_catch[signo] == 0);
8041 signal_stop_update (int signo, int state)
8043 int ret = signal_stop[signo];
8045 signal_stop[signo] = state;
8046 signal_cache_update (signo);
8051 signal_print_update (int signo, int state)
8053 int ret = signal_print[signo];
8055 signal_print[signo] = state;
8056 signal_cache_update (signo);
8061 signal_pass_update (int signo, int state)
8063 int ret = signal_program[signo];
8065 signal_program[signo] = state;
8066 signal_cache_update (signo);
8070 /* Update the global 'signal_catch' from INFO and notify the
8074 signal_catch_update (const unsigned int *info)
8078 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8079 signal_catch[i] = info[i] > 0;
8080 signal_cache_update (-1);
8081 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8085 sig_print_header (void)
8087 printf_filtered (_("Signal Stop\tPrint\tPass "
8088 "to program\tDescription\n"));
8092 sig_print_info (enum gdb_signal oursig)
8094 const char *name = gdb_signal_to_name (oursig);
8095 int name_padding = 13 - strlen (name);
8097 if (name_padding <= 0)
8100 printf_filtered ("%s", name);
8101 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8102 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8103 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8104 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8105 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8108 /* Specify how various signals in the inferior should be handled. */
8111 handle_command (char *args, int from_tty)
8114 int digits, wordlen;
8115 int sigfirst, signum, siglast;
8116 enum gdb_signal oursig;
8119 unsigned char *sigs;
8120 struct cleanup *old_chain;
8124 error_no_arg (_("signal to handle"));
8127 /* Allocate and zero an array of flags for which signals to handle. */
8129 nsigs = (int) GDB_SIGNAL_LAST;
8130 sigs = (unsigned char *) alloca (nsigs);
8131 memset (sigs, 0, nsigs);
8133 /* Break the command line up into args. */
8135 argv = gdb_buildargv (args);
8136 old_chain = make_cleanup_freeargv (argv);
8138 /* Walk through the args, looking for signal oursigs, signal names, and
8139 actions. Signal numbers and signal names may be interspersed with
8140 actions, with the actions being performed for all signals cumulatively
8141 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8143 while (*argv != NULL)
8145 wordlen = strlen (*argv);
8146 for (digits = 0; isdigit ((*argv)[digits]); digits++)
8150 sigfirst = siglast = -1;
8152 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
8154 /* Apply action to all signals except those used by the
8155 debugger. Silently skip those. */
8158 siglast = nsigs - 1;
8160 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
8162 SET_SIGS (nsigs, sigs, signal_stop);
8163 SET_SIGS (nsigs, sigs, signal_print);
8165 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
8167 UNSET_SIGS (nsigs, sigs, signal_program);
8169 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
8171 SET_SIGS (nsigs, sigs, signal_print);
8173 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
8175 SET_SIGS (nsigs, sigs, signal_program);
8177 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
8179 UNSET_SIGS (nsigs, sigs, signal_stop);
8181 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
8183 SET_SIGS (nsigs, sigs, signal_program);
8185 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
8187 UNSET_SIGS (nsigs, sigs, signal_print);
8188 UNSET_SIGS (nsigs, sigs, signal_stop);
8190 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
8192 UNSET_SIGS (nsigs, sigs, signal_program);
8194 else if (digits > 0)
8196 /* It is numeric. The numeric signal refers to our own
8197 internal signal numbering from target.h, not to host/target
8198 signal number. This is a feature; users really should be
8199 using symbolic names anyway, and the common ones like
8200 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8202 sigfirst = siglast = (int)
8203 gdb_signal_from_command (atoi (*argv));
8204 if ((*argv)[digits] == '-')
8207 gdb_signal_from_command (atoi ((*argv) + digits + 1));
8209 if (sigfirst > siglast)
8211 /* Bet he didn't figure we'd think of this case... */
8219 oursig = gdb_signal_from_name (*argv);
8220 if (oursig != GDB_SIGNAL_UNKNOWN)
8222 sigfirst = siglast = (int) oursig;
8226 /* Not a number and not a recognized flag word => complain. */
8227 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
8231 /* If any signal numbers or symbol names were found, set flags for
8232 which signals to apply actions to. */
8234 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8236 switch ((enum gdb_signal) signum)
8238 case GDB_SIGNAL_TRAP:
8239 case GDB_SIGNAL_INT:
8240 if (!allsigs && !sigs[signum])
8242 if (query (_("%s is used by the debugger.\n\
8243 Are you sure you want to change it? "),
8244 gdb_signal_to_name ((enum gdb_signal) signum)))
8250 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8251 gdb_flush (gdb_stdout);
8256 case GDB_SIGNAL_DEFAULT:
8257 case GDB_SIGNAL_UNKNOWN:
8258 /* Make sure that "all" doesn't print these. */
8269 for (signum = 0; signum < nsigs; signum++)
8272 signal_cache_update (-1);
8273 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8274 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8278 /* Show the results. */
8279 sig_print_header ();
8280 for (; signum < nsigs; signum++)
8282 sig_print_info ((enum gdb_signal) signum);
8288 do_cleanups (old_chain);
8291 /* Complete the "handle" command. */
8293 static VEC (char_ptr) *
8294 handle_completer (struct cmd_list_element *ignore,
8295 const char *text, const char *word)
8297 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
8298 static const char * const keywords[] =
8312 vec_signals = signal_completer (ignore, text, word);
8313 vec_keywords = complete_on_enum (keywords, word, word);
8315 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
8316 VEC_free (char_ptr, vec_signals);
8317 VEC_free (char_ptr, vec_keywords);
8322 gdb_signal_from_command (int num)
8324 if (num >= 1 && num <= 15)
8325 return (enum gdb_signal) num;
8326 error (_("Only signals 1-15 are valid as numeric signals.\n\
8327 Use \"info signals\" for a list of symbolic signals."));
8330 /* Print current contents of the tables set by the handle command.
8331 It is possible we should just be printing signals actually used
8332 by the current target (but for things to work right when switching
8333 targets, all signals should be in the signal tables). */
8336 signals_info (char *signum_exp, int from_tty)
8338 enum gdb_signal oursig;
8340 sig_print_header ();
8344 /* First see if this is a symbol name. */
8345 oursig = gdb_signal_from_name (signum_exp);
8346 if (oursig == GDB_SIGNAL_UNKNOWN)
8348 /* No, try numeric. */
8350 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8352 sig_print_info (oursig);
8356 printf_filtered ("\n");
8357 /* These ugly casts brought to you by the native VAX compiler. */
8358 for (oursig = GDB_SIGNAL_FIRST;
8359 (int) oursig < (int) GDB_SIGNAL_LAST;
8360 oursig = (enum gdb_signal) ((int) oursig + 1))
8364 if (oursig != GDB_SIGNAL_UNKNOWN
8365 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8366 sig_print_info (oursig);
8369 printf_filtered (_("\nUse the \"handle\" command "
8370 "to change these tables.\n"));
8373 /* Check if it makes sense to read $_siginfo from the current thread
8374 at this point. If not, throw an error. */
8377 validate_siginfo_access (void)
8379 /* No current inferior, no siginfo. */
8380 if (ptid_equal (inferior_ptid, null_ptid))
8381 error (_("No thread selected."));
8383 /* Don't try to read from a dead thread. */
8384 if (is_exited (inferior_ptid))
8385 error (_("The current thread has terminated"));
8387 /* ... or from a spinning thread. */
8388 if (is_running (inferior_ptid))
8389 error (_("Selected thread is running."));
8392 /* The $_siginfo convenience variable is a bit special. We don't know
8393 for sure the type of the value until we actually have a chance to
8394 fetch the data. The type can change depending on gdbarch, so it is
8395 also dependent on which thread you have selected.
8397 1. making $_siginfo be an internalvar that creates a new value on
8400 2. making the value of $_siginfo be an lval_computed value. */
8402 /* This function implements the lval_computed support for reading a
8406 siginfo_value_read (struct value *v)
8408 LONGEST transferred;
8410 validate_siginfo_access ();
8413 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8415 value_contents_all_raw (v),
8417 TYPE_LENGTH (value_type (v)));
8419 if (transferred != TYPE_LENGTH (value_type (v)))
8420 error (_("Unable to read siginfo"));
8423 /* This function implements the lval_computed support for writing a
8427 siginfo_value_write (struct value *v, struct value *fromval)
8429 LONGEST transferred;
8431 validate_siginfo_access ();
8433 transferred = target_write (¤t_target,
8434 TARGET_OBJECT_SIGNAL_INFO,
8436 value_contents_all_raw (fromval),
8438 TYPE_LENGTH (value_type (fromval)));
8440 if (transferred != TYPE_LENGTH (value_type (fromval)))
8441 error (_("Unable to write siginfo"));
8444 static const struct lval_funcs siginfo_value_funcs =
8450 /* Return a new value with the correct type for the siginfo object of
8451 the current thread using architecture GDBARCH. Return a void value
8452 if there's no object available. */
8454 static struct value *
8455 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8458 if (target_has_stack
8459 && !ptid_equal (inferior_ptid, null_ptid)
8460 && gdbarch_get_siginfo_type_p (gdbarch))
8462 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8464 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8467 return allocate_value (builtin_type (gdbarch)->builtin_void);
8471 /* infcall_suspend_state contains state about the program itself like its
8472 registers and any signal it received when it last stopped.
8473 This state must be restored regardless of how the inferior function call
8474 ends (either successfully, or after it hits a breakpoint or signal)
8475 if the program is to properly continue where it left off. */
8477 struct infcall_suspend_state
8479 struct thread_suspend_state thread_suspend;
8483 struct regcache *registers;
8485 /* Format of SIGINFO_DATA or NULL if it is not present. */
8486 struct gdbarch *siginfo_gdbarch;
8488 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8489 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8490 content would be invalid. */
8491 gdb_byte *siginfo_data;
8494 struct infcall_suspend_state *
8495 save_infcall_suspend_state (void)
8497 struct infcall_suspend_state *inf_state;
8498 struct thread_info *tp = inferior_thread ();
8499 struct regcache *regcache = get_current_regcache ();
8500 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8501 gdb_byte *siginfo_data = NULL;
8503 if (gdbarch_get_siginfo_type_p (gdbarch))
8505 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8506 size_t len = TYPE_LENGTH (type);
8507 struct cleanup *back_to;
8509 siginfo_data = xmalloc (len);
8510 back_to = make_cleanup (xfree, siginfo_data);
8512 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8513 siginfo_data, 0, len) == len)
8514 discard_cleanups (back_to);
8517 /* Errors ignored. */
8518 do_cleanups (back_to);
8519 siginfo_data = NULL;
8523 inf_state = XCNEW (struct infcall_suspend_state);
8527 inf_state->siginfo_gdbarch = gdbarch;
8528 inf_state->siginfo_data = siginfo_data;
8531 inf_state->thread_suspend = tp->suspend;
8533 /* run_inferior_call will not use the signal due to its `proceed' call with
8534 GDB_SIGNAL_0 anyway. */
8535 tp->suspend.stop_signal = GDB_SIGNAL_0;
8537 inf_state->stop_pc = stop_pc;
8539 inf_state->registers = regcache_dup (regcache);
8544 /* Restore inferior session state to INF_STATE. */
8547 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8549 struct thread_info *tp = inferior_thread ();
8550 struct regcache *regcache = get_current_regcache ();
8551 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8553 tp->suspend = inf_state->thread_suspend;
8555 stop_pc = inf_state->stop_pc;
8557 if (inf_state->siginfo_gdbarch == gdbarch)
8559 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8561 /* Errors ignored. */
8562 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8563 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8566 /* The inferior can be gone if the user types "print exit(0)"
8567 (and perhaps other times). */
8568 if (target_has_execution)
8569 /* NB: The register write goes through to the target. */
8570 regcache_cpy (regcache, inf_state->registers);
8572 discard_infcall_suspend_state (inf_state);
8576 do_restore_infcall_suspend_state_cleanup (void *state)
8578 restore_infcall_suspend_state (state);
8582 make_cleanup_restore_infcall_suspend_state
8583 (struct infcall_suspend_state *inf_state)
8585 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8589 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8591 regcache_xfree (inf_state->registers);
8592 xfree (inf_state->siginfo_data);
8597 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8599 return inf_state->registers;
8602 /* infcall_control_state contains state regarding gdb's control of the
8603 inferior itself like stepping control. It also contains session state like
8604 the user's currently selected frame. */
8606 struct infcall_control_state
8608 struct thread_control_state thread_control;
8609 struct inferior_control_state inferior_control;
8612 enum stop_stack_kind stop_stack_dummy;
8613 int stopped_by_random_signal;
8614 int stop_after_trap;
8616 /* ID if the selected frame when the inferior function call was made. */
8617 struct frame_id selected_frame_id;
8620 /* Save all of the information associated with the inferior<==>gdb
8623 struct infcall_control_state *
8624 save_infcall_control_state (void)
8626 struct infcall_control_state *inf_status =
8627 XNEW (struct infcall_control_state);
8628 struct thread_info *tp = inferior_thread ();
8629 struct inferior *inf = current_inferior ();
8631 inf_status->thread_control = tp->control;
8632 inf_status->inferior_control = inf->control;
8634 tp->control.step_resume_breakpoint = NULL;
8635 tp->control.exception_resume_breakpoint = NULL;
8637 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8638 chain. If caller's caller is walking the chain, they'll be happier if we
8639 hand them back the original chain when restore_infcall_control_state is
8641 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8644 inf_status->stop_stack_dummy = stop_stack_dummy;
8645 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8646 inf_status->stop_after_trap = stop_after_trap;
8648 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8654 restore_selected_frame (void *args)
8656 struct frame_id *fid = (struct frame_id *) args;
8657 struct frame_info *frame;
8659 frame = frame_find_by_id (*fid);
8661 /* If inf_status->selected_frame_id is NULL, there was no previously
8665 warning (_("Unable to restore previously selected frame."));
8669 select_frame (frame);
8674 /* Restore inferior session state to INF_STATUS. */
8677 restore_infcall_control_state (struct infcall_control_state *inf_status)
8679 struct thread_info *tp = inferior_thread ();
8680 struct inferior *inf = current_inferior ();
8682 if (tp->control.step_resume_breakpoint)
8683 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8685 if (tp->control.exception_resume_breakpoint)
8686 tp->control.exception_resume_breakpoint->disposition
8687 = disp_del_at_next_stop;
8689 /* Handle the bpstat_copy of the chain. */
8690 bpstat_clear (&tp->control.stop_bpstat);
8692 tp->control = inf_status->thread_control;
8693 inf->control = inf_status->inferior_control;
8696 stop_stack_dummy = inf_status->stop_stack_dummy;
8697 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8698 stop_after_trap = inf_status->stop_after_trap;
8700 if (target_has_stack)
8702 /* The point of catch_errors is that if the stack is clobbered,
8703 walking the stack might encounter a garbage pointer and
8704 error() trying to dereference it. */
8706 (restore_selected_frame, &inf_status->selected_frame_id,
8707 "Unable to restore previously selected frame:\n",
8708 RETURN_MASK_ERROR) == 0)
8709 /* Error in restoring the selected frame. Select the innermost
8711 select_frame (get_current_frame ());
8718 do_restore_infcall_control_state_cleanup (void *sts)
8720 restore_infcall_control_state (sts);
8724 make_cleanup_restore_infcall_control_state
8725 (struct infcall_control_state *inf_status)
8727 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
8731 discard_infcall_control_state (struct infcall_control_state *inf_status)
8733 if (inf_status->thread_control.step_resume_breakpoint)
8734 inf_status->thread_control.step_resume_breakpoint->disposition
8735 = disp_del_at_next_stop;
8737 if (inf_status->thread_control.exception_resume_breakpoint)
8738 inf_status->thread_control.exception_resume_breakpoint->disposition
8739 = disp_del_at_next_stop;
8741 /* See save_infcall_control_state for info on stop_bpstat. */
8742 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8747 /* restore_inferior_ptid() will be used by the cleanup machinery
8748 to restore the inferior_ptid value saved in a call to
8749 save_inferior_ptid(). */
8752 restore_inferior_ptid (void *arg)
8754 ptid_t *saved_ptid_ptr = arg;
8756 inferior_ptid = *saved_ptid_ptr;
8760 /* Save the value of inferior_ptid so that it may be restored by a
8761 later call to do_cleanups(). Returns the struct cleanup pointer
8762 needed for later doing the cleanup. */
8765 save_inferior_ptid (void)
8767 ptid_t *saved_ptid_ptr = XNEW (ptid_t);
8769 *saved_ptid_ptr = inferior_ptid;
8770 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
8776 clear_exit_convenience_vars (void)
8778 clear_internalvar (lookup_internalvar ("_exitsignal"));
8779 clear_internalvar (lookup_internalvar ("_exitcode"));
8783 /* User interface for reverse debugging:
8784 Set exec-direction / show exec-direction commands
8785 (returns error unless target implements to_set_exec_direction method). */
8787 int execution_direction = EXEC_FORWARD;
8788 static const char exec_forward[] = "forward";
8789 static const char exec_reverse[] = "reverse";
8790 static const char *exec_direction = exec_forward;
8791 static const char *const exec_direction_names[] = {
8798 set_exec_direction_func (char *args, int from_tty,
8799 struct cmd_list_element *cmd)
8801 if (target_can_execute_reverse)
8803 if (!strcmp (exec_direction, exec_forward))
8804 execution_direction = EXEC_FORWARD;
8805 else if (!strcmp (exec_direction, exec_reverse))
8806 execution_direction = EXEC_REVERSE;
8810 exec_direction = exec_forward;
8811 error (_("Target does not support this operation."));
8816 show_exec_direction_func (struct ui_file *out, int from_tty,
8817 struct cmd_list_element *cmd, const char *value)
8819 switch (execution_direction) {
8821 fprintf_filtered (out, _("Forward.\n"));
8824 fprintf_filtered (out, _("Reverse.\n"));
8827 internal_error (__FILE__, __LINE__,
8828 _("bogus execution_direction value: %d"),
8829 (int) execution_direction);
8834 show_schedule_multiple (struct ui_file *file, int from_tty,
8835 struct cmd_list_element *c, const char *value)
8837 fprintf_filtered (file, _("Resuming the execution of threads "
8838 "of all processes is %s.\n"), value);
8841 /* Implementation of `siginfo' variable. */
8843 static const struct internalvar_funcs siginfo_funcs =
8850 /* Callback for infrun's target events source. This is marked when a
8851 thread has a pending status to process. */
8854 infrun_async_inferior_event_handler (gdb_client_data data)
8856 inferior_event_handler (INF_REG_EVENT, NULL);
8860 _initialize_infrun (void)
8864 struct cmd_list_element *c;
8866 /* Register extra event sources in the event loop. */
8867 infrun_async_inferior_event_token
8868 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
8870 add_info ("signals", signals_info, _("\
8871 What debugger does when program gets various signals.\n\
8872 Specify a signal as argument to print info on that signal only."));
8873 add_info_alias ("handle", "signals", 0);
8875 c = add_com ("handle", class_run, handle_command, _("\
8876 Specify how to handle signals.\n\
8877 Usage: handle SIGNAL [ACTIONS]\n\
8878 Args are signals and actions to apply to those signals.\n\
8879 If no actions are specified, the current settings for the specified signals\n\
8880 will be displayed instead.\n\
8882 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8883 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8884 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8885 The special arg \"all\" is recognized to mean all signals except those\n\
8886 used by the debugger, typically SIGTRAP and SIGINT.\n\
8888 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8889 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8890 Stop means reenter debugger if this signal happens (implies print).\n\
8891 Print means print a message if this signal happens.\n\
8892 Pass means let program see this signal; otherwise program doesn't know.\n\
8893 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8894 Pass and Stop may be combined.\n\
8896 Multiple signals may be specified. Signal numbers and signal names\n\
8897 may be interspersed with actions, with the actions being performed for\n\
8898 all signals cumulatively specified."));
8899 set_cmd_completer (c, handle_completer);
8902 stop_command = add_cmd ("stop", class_obscure,
8903 not_just_help_class_command, _("\
8904 There is no `stop' command, but you can set a hook on `stop'.\n\
8905 This allows you to set a list of commands to be run each time execution\n\
8906 of the program stops."), &cmdlist);
8908 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
8909 Set inferior debugging."), _("\
8910 Show inferior debugging."), _("\
8911 When non-zero, inferior specific debugging is enabled."),
8914 &setdebuglist, &showdebuglist);
8916 add_setshow_boolean_cmd ("displaced", class_maintenance,
8917 &debug_displaced, _("\
8918 Set displaced stepping debugging."), _("\
8919 Show displaced stepping debugging."), _("\
8920 When non-zero, displaced stepping specific debugging is enabled."),
8922 show_debug_displaced,
8923 &setdebuglist, &showdebuglist);
8925 add_setshow_boolean_cmd ("non-stop", no_class,
8927 Set whether gdb controls the inferior in non-stop mode."), _("\
8928 Show whether gdb controls the inferior in non-stop mode."), _("\
8929 When debugging a multi-threaded program and this setting is\n\
8930 off (the default, also called all-stop mode), when one thread stops\n\
8931 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
8932 all other threads in the program while you interact with the thread of\n\
8933 interest. When you continue or step a thread, you can allow the other\n\
8934 threads to run, or have them remain stopped, but while you inspect any\n\
8935 thread's state, all threads stop.\n\
8937 In non-stop mode, when one thread stops, other threads can continue\n\
8938 to run freely. You'll be able to step each thread independently,\n\
8939 leave it stopped or free to run as needed."),
8945 numsigs = (int) GDB_SIGNAL_LAST;
8946 signal_stop = XNEWVEC (unsigned char, numsigs);
8947 signal_print = XNEWVEC (unsigned char, numsigs);
8948 signal_program = XNEWVEC (unsigned char, numsigs);
8949 signal_catch = XNEWVEC (unsigned char, numsigs);
8950 signal_pass = XNEWVEC (unsigned char, numsigs);
8951 for (i = 0; i < numsigs; i++)
8954 signal_print[i] = 1;
8955 signal_program[i] = 1;
8956 signal_catch[i] = 0;
8959 /* Signals caused by debugger's own actions should not be given to
8960 the program afterwards.
8962 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
8963 explicitly specifies that it should be delivered to the target
8964 program. Typically, that would occur when a user is debugging a
8965 target monitor on a simulator: the target monitor sets a
8966 breakpoint; the simulator encounters this breakpoint and halts
8967 the simulation handing control to GDB; GDB, noting that the stop
8968 address doesn't map to any known breakpoint, returns control back
8969 to the simulator; the simulator then delivers the hardware
8970 equivalent of a GDB_SIGNAL_TRAP to the program being
8972 signal_program[GDB_SIGNAL_TRAP] = 0;
8973 signal_program[GDB_SIGNAL_INT] = 0;
8975 /* Signals that are not errors should not normally enter the debugger. */
8976 signal_stop[GDB_SIGNAL_ALRM] = 0;
8977 signal_print[GDB_SIGNAL_ALRM] = 0;
8978 signal_stop[GDB_SIGNAL_VTALRM] = 0;
8979 signal_print[GDB_SIGNAL_VTALRM] = 0;
8980 signal_stop[GDB_SIGNAL_PROF] = 0;
8981 signal_print[GDB_SIGNAL_PROF] = 0;
8982 signal_stop[GDB_SIGNAL_CHLD] = 0;
8983 signal_print[GDB_SIGNAL_CHLD] = 0;
8984 signal_stop[GDB_SIGNAL_IO] = 0;
8985 signal_print[GDB_SIGNAL_IO] = 0;
8986 signal_stop[GDB_SIGNAL_POLL] = 0;
8987 signal_print[GDB_SIGNAL_POLL] = 0;
8988 signal_stop[GDB_SIGNAL_URG] = 0;
8989 signal_print[GDB_SIGNAL_URG] = 0;
8990 signal_stop[GDB_SIGNAL_WINCH] = 0;
8991 signal_print[GDB_SIGNAL_WINCH] = 0;
8992 signal_stop[GDB_SIGNAL_PRIO] = 0;
8993 signal_print[GDB_SIGNAL_PRIO] = 0;
8995 /* These signals are used internally by user-level thread
8996 implementations. (See signal(5) on Solaris.) Like the above
8997 signals, a healthy program receives and handles them as part of
8998 its normal operation. */
8999 signal_stop[GDB_SIGNAL_LWP] = 0;
9000 signal_print[GDB_SIGNAL_LWP] = 0;
9001 signal_stop[GDB_SIGNAL_WAITING] = 0;
9002 signal_print[GDB_SIGNAL_WAITING] = 0;
9003 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9004 signal_print[GDB_SIGNAL_CANCEL] = 0;
9006 /* Update cached state. */
9007 signal_cache_update (-1);
9009 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9010 &stop_on_solib_events, _("\
9011 Set stopping for shared library events."), _("\
9012 Show stopping for shared library events."), _("\
9013 If nonzero, gdb will give control to the user when the dynamic linker\n\
9014 notifies gdb of shared library events. The most common event of interest\n\
9015 to the user would be loading/unloading of a new library."),
9016 set_stop_on_solib_events,
9017 show_stop_on_solib_events,
9018 &setlist, &showlist);
9020 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9021 follow_fork_mode_kind_names,
9022 &follow_fork_mode_string, _("\
9023 Set debugger response to a program call of fork or vfork."), _("\
9024 Show debugger response to a program call of fork or vfork."), _("\
9025 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9026 parent - the original process is debugged after a fork\n\
9027 child - the new process is debugged after a fork\n\
9028 The unfollowed process will continue to run.\n\
9029 By default, the debugger will follow the parent process."),
9031 show_follow_fork_mode_string,
9032 &setlist, &showlist);
9034 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9035 follow_exec_mode_names,
9036 &follow_exec_mode_string, _("\
9037 Set debugger response to a program call of exec."), _("\
9038 Show debugger response to a program call of exec."), _("\
9039 An exec call replaces the program image of a process.\n\
9041 follow-exec-mode can be:\n\
9043 new - the debugger creates a new inferior and rebinds the process\n\
9044 to this new inferior. The program the process was running before\n\
9045 the exec call can be restarted afterwards by restarting the original\n\
9048 same - the debugger keeps the process bound to the same inferior.\n\
9049 The new executable image replaces the previous executable loaded in\n\
9050 the inferior. Restarting the inferior after the exec call restarts\n\
9051 the executable the process was running after the exec call.\n\
9053 By default, the debugger will use the same inferior."),
9055 show_follow_exec_mode_string,
9056 &setlist, &showlist);
9058 add_setshow_enum_cmd ("scheduler-locking", class_run,
9059 scheduler_enums, &scheduler_mode, _("\
9060 Set mode for locking scheduler during execution."), _("\
9061 Show mode for locking scheduler during execution."), _("\
9062 off == no locking (threads may preempt at any time)\n\
9063 on == full locking (no thread except the current thread may run)\n\
9064 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9065 In this mode, other threads may run during other commands."),
9066 set_schedlock_func, /* traps on target vector */
9067 show_scheduler_mode,
9068 &setlist, &showlist);
9070 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9071 Set mode for resuming threads of all processes."), _("\
9072 Show mode for resuming threads of all processes."), _("\
9073 When on, execution commands (such as 'continue' or 'next') resume all\n\
9074 threads of all processes. When off (which is the default), execution\n\
9075 commands only resume the threads of the current process. The set of\n\
9076 threads that are resumed is further refined by the scheduler-locking\n\
9077 mode (see help set scheduler-locking)."),
9079 show_schedule_multiple,
9080 &setlist, &showlist);
9082 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9083 Set mode of the step operation."), _("\
9084 Show mode of the step operation."), _("\
9085 When set, doing a step over a function without debug line information\n\
9086 will stop at the first instruction of that function. Otherwise, the\n\
9087 function is skipped and the step command stops at a different source line."),
9089 show_step_stop_if_no_debug,
9090 &setlist, &showlist);
9092 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9093 &can_use_displaced_stepping, _("\
9094 Set debugger's willingness to use displaced stepping."), _("\
9095 Show debugger's willingness to use displaced stepping."), _("\
9096 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9097 supported by the target architecture. If off, gdb will not use displaced\n\
9098 stepping to step over breakpoints, even if such is supported by the target\n\
9099 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9100 if the target architecture supports it and non-stop mode is active, but will not\n\
9101 use it in all-stop mode (see help set non-stop)."),
9103 show_can_use_displaced_stepping,
9104 &setlist, &showlist);
9106 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9107 &exec_direction, _("Set direction of execution.\n\
9108 Options are 'forward' or 'reverse'."),
9109 _("Show direction of execution (forward/reverse)."),
9110 _("Tells gdb whether to execute forward or backward."),
9111 set_exec_direction_func, show_exec_direction_func,
9112 &setlist, &showlist);
9114 /* Set/show detach-on-fork: user-settable mode. */
9116 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9117 Set whether gdb will detach the child of a fork."), _("\
9118 Show whether gdb will detach the child of a fork."), _("\
9119 Tells gdb whether to detach the child of a fork."),
9120 NULL, NULL, &setlist, &showlist);
9122 /* Set/show disable address space randomization mode. */
9124 add_setshow_boolean_cmd ("disable-randomization", class_support,
9125 &disable_randomization, _("\
9126 Set disabling of debuggee's virtual address space randomization."), _("\
9127 Show disabling of debuggee's virtual address space randomization."), _("\
9128 When this mode is on (which is the default), randomization of the virtual\n\
9129 address space is disabled. Standalone programs run with the randomization\n\
9130 enabled by default on some platforms."),
9131 &set_disable_randomization,
9132 &show_disable_randomization,
9133 &setlist, &showlist);
9135 /* ptid initializations */
9136 inferior_ptid = null_ptid;
9137 target_last_wait_ptid = minus_one_ptid;
9139 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9140 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9141 observer_attach_thread_exit (infrun_thread_thread_exit);
9142 observer_attach_inferior_exit (infrun_inferior_exit);
9144 /* Explicitly create without lookup, since that tries to create a
9145 value with a void typed value, and when we get here, gdbarch
9146 isn't initialized yet. At this point, we're quite sure there
9147 isn't another convenience variable of the same name. */
9148 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9150 add_setshow_boolean_cmd ("observer", no_class,
9151 &observer_mode_1, _("\
9152 Set whether gdb controls the inferior in observer mode."), _("\
9153 Show whether gdb controls the inferior in observer mode."), _("\
9154 In observer mode, GDB can get data from the inferior, but not\n\
9155 affect its execution. Registers and memory may not be changed,\n\
9156 breakpoints may not be set, and the program cannot be interrupted\n\