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);
2707 /* Counter that tracks number of user visible stops. This can be used
2708 to tell whether a command has proceeded the inferior past the
2709 current location. This allows e.g., inferior function calls in
2710 breakpoint commands to not interrupt the command list. When the
2711 call finishes successfully, the inferior is standing at the same
2712 breakpoint as if nothing happened (and so we don't call
2714 static ULONGEST current_stop_id;
2721 return current_stop_id;
2724 /* Called when we report a user visible stop. */
2732 /* Clear out all variables saying what to do when inferior is continued.
2733 First do this, then set the ones you want, then call `proceed'. */
2736 clear_proceed_status_thread (struct thread_info *tp)
2739 fprintf_unfiltered (gdb_stdlog,
2740 "infrun: clear_proceed_status_thread (%s)\n",
2741 target_pid_to_str (tp->ptid));
2743 /* If we're starting a new sequence, then the previous finished
2744 single-step is no longer relevant. */
2745 if (tp->suspend.waitstatus_pending_p)
2747 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2750 fprintf_unfiltered (gdb_stdlog,
2751 "infrun: clear_proceed_status: pending "
2752 "event of %s was a finished step. "
2754 target_pid_to_str (tp->ptid));
2756 tp->suspend.waitstatus_pending_p = 0;
2757 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2759 else if (debug_infrun)
2763 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2764 fprintf_unfiltered (gdb_stdlog,
2765 "infrun: clear_proceed_status_thread: thread %s "
2766 "has pending wait status %s "
2767 "(currently_stepping=%d).\n",
2768 target_pid_to_str (tp->ptid), statstr,
2769 currently_stepping (tp));
2774 /* If this signal should not be seen by program, give it zero.
2775 Used for debugging signals. */
2776 if (!signal_pass_state (tp->suspend.stop_signal))
2777 tp->suspend.stop_signal = GDB_SIGNAL_0;
2779 thread_fsm_delete (tp->thread_fsm);
2780 tp->thread_fsm = NULL;
2782 tp->control.trap_expected = 0;
2783 tp->control.step_range_start = 0;
2784 tp->control.step_range_end = 0;
2785 tp->control.may_range_step = 0;
2786 tp->control.step_frame_id = null_frame_id;
2787 tp->control.step_stack_frame_id = null_frame_id;
2788 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2789 tp->control.step_start_function = NULL;
2790 tp->stop_requested = 0;
2792 tp->control.stop_step = 0;
2794 tp->control.proceed_to_finish = 0;
2796 tp->control.command_interp = NULL;
2797 tp->control.stepping_command = 0;
2799 /* Discard any remaining commands or status from previous stop. */
2800 bpstat_clear (&tp->control.stop_bpstat);
2804 clear_proceed_status (int step)
2808 struct thread_info *tp;
2811 resume_ptid = user_visible_resume_ptid (step);
2813 /* In all-stop mode, delete the per-thread status of all threads
2814 we're about to resume, implicitly and explicitly. */
2815 ALL_NON_EXITED_THREADS (tp)
2817 if (!ptid_match (tp->ptid, resume_ptid))
2819 clear_proceed_status_thread (tp);
2823 if (!ptid_equal (inferior_ptid, null_ptid))
2825 struct inferior *inferior;
2829 /* If in non-stop mode, only delete the per-thread status of
2830 the current thread. */
2831 clear_proceed_status_thread (inferior_thread ());
2834 inferior = current_inferior ();
2835 inferior->control.stop_soon = NO_STOP_QUIETLY;
2838 stop_after_trap = 0;
2840 observer_notify_about_to_proceed ();
2843 /* Returns true if TP is still stopped at a breakpoint that needs
2844 stepping-over in order to make progress. If the breakpoint is gone
2845 meanwhile, we can skip the whole step-over dance. */
2848 thread_still_needs_step_over_bp (struct thread_info *tp)
2850 if (tp->stepping_over_breakpoint)
2852 struct regcache *regcache = get_thread_regcache (tp->ptid);
2854 if (breakpoint_here_p (get_regcache_aspace (regcache),
2855 regcache_read_pc (regcache))
2856 == ordinary_breakpoint_here)
2859 tp->stepping_over_breakpoint = 0;
2865 /* Check whether thread TP still needs to start a step-over in order
2866 to make progress when resumed. Returns an bitwise or of enum
2867 step_over_what bits, indicating what needs to be stepped over. */
2870 thread_still_needs_step_over (struct thread_info *tp)
2872 struct inferior *inf = find_inferior_ptid (tp->ptid);
2875 if (thread_still_needs_step_over_bp (tp))
2876 what |= STEP_OVER_BREAKPOINT;
2878 if (tp->stepping_over_watchpoint
2879 && !target_have_steppable_watchpoint)
2880 what |= STEP_OVER_WATCHPOINT;
2885 /* Returns true if scheduler locking applies. STEP indicates whether
2886 we're about to do a step/next-like command to a thread. */
2889 schedlock_applies (struct thread_info *tp)
2891 return (scheduler_mode == schedlock_on
2892 || (scheduler_mode == schedlock_step
2893 && tp->control.stepping_command));
2896 /* Basic routine for continuing the program in various fashions.
2898 ADDR is the address to resume at, or -1 for resume where stopped.
2899 SIGGNAL is the signal to give it, or 0 for none,
2900 or -1 for act according to how it stopped.
2901 STEP is nonzero if should trap after one instruction.
2902 -1 means return after that and print nothing.
2903 You should probably set various step_... variables
2904 before calling here, if you are stepping.
2906 You should call clear_proceed_status before calling proceed. */
2909 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2911 struct regcache *regcache;
2912 struct gdbarch *gdbarch;
2913 struct thread_info *tp;
2915 struct address_space *aspace;
2917 struct execution_control_state ecss;
2918 struct execution_control_state *ecs = &ecss;
2919 struct cleanup *old_chain;
2922 /* If we're stopped at a fork/vfork, follow the branch set by the
2923 "set follow-fork-mode" command; otherwise, we'll just proceed
2924 resuming the current thread. */
2925 if (!follow_fork ())
2927 /* The target for some reason decided not to resume. */
2929 if (target_can_async_p ())
2930 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2934 /* We'll update this if & when we switch to a new thread. */
2935 previous_inferior_ptid = inferior_ptid;
2937 regcache = get_current_regcache ();
2938 gdbarch = get_regcache_arch (regcache);
2939 aspace = get_regcache_aspace (regcache);
2940 pc = regcache_read_pc (regcache);
2941 tp = inferior_thread ();
2943 /* Fill in with reasonable starting values. */
2944 init_thread_stepping_state (tp);
2946 gdb_assert (!thread_is_in_step_over_chain (tp));
2948 if (addr == (CORE_ADDR) -1)
2951 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2952 && execution_direction != EXEC_REVERSE)
2953 /* There is a breakpoint at the address we will resume at,
2954 step one instruction before inserting breakpoints so that
2955 we do not stop right away (and report a second hit at this
2958 Note, we don't do this in reverse, because we won't
2959 actually be executing the breakpoint insn anyway.
2960 We'll be (un-)executing the previous instruction. */
2961 tp->stepping_over_breakpoint = 1;
2962 else if (gdbarch_single_step_through_delay_p (gdbarch)
2963 && gdbarch_single_step_through_delay (gdbarch,
2964 get_current_frame ()))
2965 /* We stepped onto an instruction that needs to be stepped
2966 again before re-inserting the breakpoint, do so. */
2967 tp->stepping_over_breakpoint = 1;
2971 regcache_write_pc (regcache, addr);
2974 if (siggnal != GDB_SIGNAL_DEFAULT)
2975 tp->suspend.stop_signal = siggnal;
2977 /* Record the interpreter that issued the execution command that
2978 caused this thread to resume. If the top level interpreter is
2979 MI/async, and the execution command was a CLI command
2980 (next/step/etc.), we'll want to print stop event output to the MI
2981 console channel (the stepped-to line, etc.), as if the user
2982 entered the execution command on a real GDB console. */
2983 tp->control.command_interp = command_interp ();
2985 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
2987 /* If an exception is thrown from this point on, make sure to
2988 propagate GDB's knowledge of the executing state to the
2989 frontend/user running state. */
2990 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
2992 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2993 threads (e.g., we might need to set threads stepping over
2994 breakpoints first), from the user/frontend's point of view, all
2995 threads in RESUME_PTID are now running. Unless we're calling an
2996 inferior function, as in that case we pretend the inferior
2997 doesn't run at all. */
2998 if (!tp->control.in_infcall)
2999 set_running (resume_ptid, 1);
3002 fprintf_unfiltered (gdb_stdlog,
3003 "infrun: proceed (addr=%s, signal=%s)\n",
3004 paddress (gdbarch, addr),
3005 gdb_signal_to_symbol_string (siggnal));
3007 annotate_starting ();
3009 /* Make sure that output from GDB appears before output from the
3011 gdb_flush (gdb_stdout);
3013 /* In a multi-threaded task we may select another thread and
3014 then continue or step.
3016 But if a thread that we're resuming had stopped at a breakpoint,
3017 it will immediately cause another breakpoint stop without any
3018 execution (i.e. it will report a breakpoint hit incorrectly). So
3019 we must step over it first.
3021 Look for threads other than the current (TP) that reported a
3022 breakpoint hit and haven't been resumed yet since. */
3024 /* If scheduler locking applies, we can avoid iterating over all
3026 if (!non_stop && !schedlock_applies (tp))
3028 struct thread_info *current = tp;
3030 ALL_NON_EXITED_THREADS (tp)
3032 /* Ignore the current thread here. It's handled
3037 /* Ignore threads of processes we're not resuming. */
3038 if (!ptid_match (tp->ptid, resume_ptid))
3041 if (!thread_still_needs_step_over (tp))
3044 gdb_assert (!thread_is_in_step_over_chain (tp));
3047 fprintf_unfiltered (gdb_stdlog,
3048 "infrun: need to step-over [%s] first\n",
3049 target_pid_to_str (tp->ptid));
3051 thread_step_over_chain_enqueue (tp);
3057 /* Enqueue the current thread last, so that we move all other
3058 threads over their breakpoints first. */
3059 if (tp->stepping_over_breakpoint)
3060 thread_step_over_chain_enqueue (tp);
3062 /* If the thread isn't started, we'll still need to set its prev_pc,
3063 so that switch_back_to_stepped_thread knows the thread hasn't
3064 advanced. Must do this before resuming any thread, as in
3065 all-stop/remote, once we resume we can't send any other packet
3066 until the target stops again. */
3067 tp->prev_pc = regcache_read_pc (regcache);
3069 started = start_step_over ();
3071 if (step_over_info_valid_p ())
3073 /* Either this thread started a new in-line step over, or some
3074 other thread was already doing one. In either case, don't
3075 resume anything else until the step-over is finished. */
3077 else if (started && !target_is_non_stop_p ())
3079 /* A new displaced stepping sequence was started. In all-stop,
3080 we can't talk to the target anymore until it next stops. */
3082 else if (!non_stop && target_is_non_stop_p ())
3084 /* In all-stop, but the target is always in non-stop mode.
3085 Start all other threads that are implicitly resumed too. */
3086 ALL_NON_EXITED_THREADS (tp)
3088 /* Ignore threads of processes we're not resuming. */
3089 if (!ptid_match (tp->ptid, resume_ptid))
3095 fprintf_unfiltered (gdb_stdlog,
3096 "infrun: proceed: [%s] resumed\n",
3097 target_pid_to_str (tp->ptid));
3098 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3102 if (thread_is_in_step_over_chain (tp))
3105 fprintf_unfiltered (gdb_stdlog,
3106 "infrun: proceed: [%s] needs step-over\n",
3107 target_pid_to_str (tp->ptid));
3112 fprintf_unfiltered (gdb_stdlog,
3113 "infrun: proceed: resuming %s\n",
3114 target_pid_to_str (tp->ptid));
3116 reset_ecs (ecs, tp);
3117 switch_to_thread (tp->ptid);
3118 keep_going_pass_signal (ecs);
3119 if (!ecs->wait_some_more)
3120 error (_("Command aborted."));
3123 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3125 /* The thread wasn't started, and isn't queued, run it now. */
3126 reset_ecs (ecs, tp);
3127 switch_to_thread (tp->ptid);
3128 keep_going_pass_signal (ecs);
3129 if (!ecs->wait_some_more)
3130 error (_("Command aborted."));
3133 discard_cleanups (old_chain);
3135 /* Tell the event loop to wait for it to stop. If the target
3136 supports asynchronous execution, it'll do this from within
3138 if (!target_can_async_p ())
3139 mark_async_event_handler (infrun_async_inferior_event_token);
3143 /* Start remote-debugging of a machine over a serial link. */
3146 start_remote (int from_tty)
3148 struct inferior *inferior;
3150 inferior = current_inferior ();
3151 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3153 /* Always go on waiting for the target, regardless of the mode. */
3154 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3155 indicate to wait_for_inferior that a target should timeout if
3156 nothing is returned (instead of just blocking). Because of this,
3157 targets expecting an immediate response need to, internally, set
3158 things up so that the target_wait() is forced to eventually
3160 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3161 differentiate to its caller what the state of the target is after
3162 the initial open has been performed. Here we're assuming that
3163 the target has stopped. It should be possible to eventually have
3164 target_open() return to the caller an indication that the target
3165 is currently running and GDB state should be set to the same as
3166 for an async run. */
3167 wait_for_inferior ();
3169 /* Now that the inferior has stopped, do any bookkeeping like
3170 loading shared libraries. We want to do this before normal_stop,
3171 so that the displayed frame is up to date. */
3172 post_create_inferior (¤t_target, from_tty);
3177 /* Initialize static vars when a new inferior begins. */
3180 init_wait_for_inferior (void)
3182 /* These are meaningless until the first time through wait_for_inferior. */
3184 breakpoint_init_inferior (inf_starting);
3186 clear_proceed_status (0);
3188 target_last_wait_ptid = minus_one_ptid;
3190 previous_inferior_ptid = inferior_ptid;
3192 /* Discard any skipped inlined frames. */
3193 clear_inline_frame_state (minus_one_ptid);
3198 static void handle_inferior_event (struct execution_control_state *ecs);
3200 static void handle_step_into_function (struct gdbarch *gdbarch,
3201 struct execution_control_state *ecs);
3202 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3203 struct execution_control_state *ecs);
3204 static void handle_signal_stop (struct execution_control_state *ecs);
3205 static void check_exception_resume (struct execution_control_state *,
3206 struct frame_info *);
3208 static void end_stepping_range (struct execution_control_state *ecs);
3209 static void stop_waiting (struct execution_control_state *ecs);
3210 static void keep_going (struct execution_control_state *ecs);
3211 static void process_event_stop_test (struct execution_control_state *ecs);
3212 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3214 /* Callback for iterate over threads. If the thread is stopped, but
3215 the user/frontend doesn't know about that yet, go through
3216 normal_stop, as if the thread had just stopped now. ARG points at
3217 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
3218 ptid_is_pid(PTID) is true, applies to all threads of the process
3219 pointed at by PTID. Otherwise, apply only to the thread pointed by
3223 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
3225 ptid_t ptid = * (ptid_t *) arg;
3227 if ((ptid_equal (info->ptid, ptid)
3228 || ptid_equal (minus_one_ptid, ptid)
3229 || (ptid_is_pid (ptid)
3230 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
3231 && is_running (info->ptid)
3232 && !is_executing (info->ptid))
3234 struct cleanup *old_chain;
3235 struct execution_control_state ecss;
3236 struct execution_control_state *ecs = &ecss;
3238 memset (ecs, 0, sizeof (*ecs));
3240 old_chain = make_cleanup_restore_current_thread ();
3242 overlay_cache_invalid = 1;
3243 /* Flush target cache before starting to handle each event.
3244 Target was running and cache could be stale. This is just a
3245 heuristic. Running threads may modify target memory, but we
3246 don't get any event. */
3247 target_dcache_invalidate ();
3249 /* Go through handle_inferior_event/normal_stop, so we always
3250 have consistent output as if the stop event had been
3252 ecs->ptid = info->ptid;
3253 ecs->event_thread = info;
3254 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
3255 ecs->ws.value.sig = GDB_SIGNAL_0;
3257 handle_inferior_event (ecs);
3259 if (!ecs->wait_some_more)
3261 /* Cancel any running execution command. */
3262 thread_cancel_execution_command (info);
3267 do_cleanups (old_chain);
3273 /* This function is attached as a "thread_stop_requested" observer.
3274 Cleanup local state that assumed the PTID was to be resumed, and
3275 report the stop to the frontend. */
3278 infrun_thread_stop_requested (ptid_t ptid)
3280 struct thread_info *tp;
3282 /* PTID was requested to stop. Remove matching threads from the
3283 step-over queue, so we don't try to resume them
3285 ALL_NON_EXITED_THREADS (tp)
3286 if (ptid_match (tp->ptid, ptid))
3288 if (thread_is_in_step_over_chain (tp))
3289 thread_step_over_chain_remove (tp);
3292 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
3296 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3298 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3299 nullify_last_target_wait_ptid ();
3302 /* Delete the step resume, single-step and longjmp/exception resume
3303 breakpoints of TP. */
3306 delete_thread_infrun_breakpoints (struct thread_info *tp)
3308 delete_step_resume_breakpoint (tp);
3309 delete_exception_resume_breakpoint (tp);
3310 delete_single_step_breakpoints (tp);
3313 /* If the target still has execution, call FUNC for each thread that
3314 just stopped. In all-stop, that's all the non-exited threads; in
3315 non-stop, that's the current thread, only. */
3317 typedef void (*for_each_just_stopped_thread_callback_func)
3318 (struct thread_info *tp);
3321 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3323 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3326 if (target_is_non_stop_p ())
3328 /* If in non-stop mode, only the current thread stopped. */
3329 func (inferior_thread ());
3333 struct thread_info *tp;
3335 /* In all-stop mode, all threads have stopped. */
3336 ALL_NON_EXITED_THREADS (tp)
3343 /* Delete the step resume and longjmp/exception resume breakpoints of
3344 the threads that just stopped. */
3347 delete_just_stopped_threads_infrun_breakpoints (void)
3349 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3352 /* Delete the single-step breakpoints of the threads that just
3356 delete_just_stopped_threads_single_step_breakpoints (void)
3358 for_each_just_stopped_thread (delete_single_step_breakpoints);
3361 /* A cleanup wrapper. */
3364 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3366 delete_just_stopped_threads_infrun_breakpoints ();
3372 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3373 const struct target_waitstatus *ws)
3375 char *status_string = target_waitstatus_to_string (ws);
3376 struct ui_file *tmp_stream = mem_fileopen ();
3379 /* The text is split over several lines because it was getting too long.
3380 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3381 output as a unit; we want only one timestamp printed if debug_timestamp
3384 fprintf_unfiltered (tmp_stream,
3385 "infrun: target_wait (%d.%ld.%ld",
3386 ptid_get_pid (waiton_ptid),
3387 ptid_get_lwp (waiton_ptid),
3388 ptid_get_tid (waiton_ptid));
3389 if (ptid_get_pid (waiton_ptid) != -1)
3390 fprintf_unfiltered (tmp_stream,
3391 " [%s]", target_pid_to_str (waiton_ptid));
3392 fprintf_unfiltered (tmp_stream, ", status) =\n");
3393 fprintf_unfiltered (tmp_stream,
3394 "infrun: %d.%ld.%ld [%s],\n",
3395 ptid_get_pid (result_ptid),
3396 ptid_get_lwp (result_ptid),
3397 ptid_get_tid (result_ptid),
3398 target_pid_to_str (result_ptid));
3399 fprintf_unfiltered (tmp_stream,
3403 text = ui_file_xstrdup (tmp_stream, NULL);
3405 /* This uses %s in part to handle %'s in the text, but also to avoid
3406 a gcc error: the format attribute requires a string literal. */
3407 fprintf_unfiltered (gdb_stdlog, "%s", text);
3409 xfree (status_string);
3411 ui_file_delete (tmp_stream);
3414 /* Select a thread at random, out of those which are resumed and have
3417 static struct thread_info *
3418 random_pending_event_thread (ptid_t waiton_ptid)
3420 struct thread_info *event_tp;
3422 int random_selector;
3424 /* First see how many events we have. Count only resumed threads
3425 that have an event pending. */
3426 ALL_NON_EXITED_THREADS (event_tp)
3427 if (ptid_match (event_tp->ptid, waiton_ptid)
3428 && event_tp->resumed
3429 && event_tp->suspend.waitstatus_pending_p)
3432 if (num_events == 0)
3435 /* Now randomly pick a thread out of those that have had events. */
3436 random_selector = (int)
3437 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3439 if (debug_infrun && num_events > 1)
3440 fprintf_unfiltered (gdb_stdlog,
3441 "infrun: Found %d events, selecting #%d\n",
3442 num_events, random_selector);
3444 /* Select the Nth thread that has had an event. */
3445 ALL_NON_EXITED_THREADS (event_tp)
3446 if (ptid_match (event_tp->ptid, waiton_ptid)
3447 && event_tp->resumed
3448 && event_tp->suspend.waitstatus_pending_p)
3449 if (random_selector-- == 0)
3455 /* Wrapper for target_wait that first checks whether threads have
3456 pending statuses to report before actually asking the target for
3460 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3463 struct thread_info *tp;
3465 /* First check if there is a resumed thread with a wait status
3467 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3469 tp = random_pending_event_thread (ptid);
3474 fprintf_unfiltered (gdb_stdlog,
3475 "infrun: Waiting for specific thread %s.\n",
3476 target_pid_to_str (ptid));
3478 /* We have a specific thread to check. */
3479 tp = find_thread_ptid (ptid);
3480 gdb_assert (tp != NULL);
3481 if (!tp->suspend.waitstatus_pending_p)
3486 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3487 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3489 struct regcache *regcache = get_thread_regcache (tp->ptid);
3490 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3494 pc = regcache_read_pc (regcache);
3496 if (pc != tp->suspend.stop_pc)
3499 fprintf_unfiltered (gdb_stdlog,
3500 "infrun: PC of %s changed. was=%s, now=%s\n",
3501 target_pid_to_str (tp->ptid),
3502 paddress (gdbarch, tp->prev_pc),
3503 paddress (gdbarch, pc));
3506 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3509 fprintf_unfiltered (gdb_stdlog,
3510 "infrun: previous breakpoint of %s, at %s gone\n",
3511 target_pid_to_str (tp->ptid),
3512 paddress (gdbarch, pc));
3520 fprintf_unfiltered (gdb_stdlog,
3521 "infrun: pending event of %s cancelled.\n",
3522 target_pid_to_str (tp->ptid));
3524 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3525 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3535 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
3536 fprintf_unfiltered (gdb_stdlog,
3537 "infrun: Using pending wait status %s for %s.\n",
3539 target_pid_to_str (tp->ptid));
3543 /* Now that we've selected our final event LWP, un-adjust its PC
3544 if it was a software breakpoint (and the target doesn't
3545 always adjust the PC itself). */
3546 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3547 && !target_supports_stopped_by_sw_breakpoint ())
3549 struct regcache *regcache;
3550 struct gdbarch *gdbarch;
3553 regcache = get_thread_regcache (tp->ptid);
3554 gdbarch = get_regcache_arch (regcache);
3556 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3561 pc = regcache_read_pc (regcache);
3562 regcache_write_pc (regcache, pc + decr_pc);
3566 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3567 *status = tp->suspend.waitstatus;
3568 tp->suspend.waitstatus_pending_p = 0;
3570 /* Wake up the event loop again, until all pending events are
3572 if (target_is_async_p ())
3573 mark_async_event_handler (infrun_async_inferior_event_token);
3577 /* But if we don't find one, we'll have to wait. */
3579 if (deprecated_target_wait_hook)
3580 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3582 event_ptid = target_wait (ptid, status, options);
3587 /* Prepare and stabilize the inferior for detaching it. E.g.,
3588 detaching while a thread is displaced stepping is a recipe for
3589 crashing it, as nothing would readjust the PC out of the scratch
3593 prepare_for_detach (void)
3595 struct inferior *inf = current_inferior ();
3596 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3597 struct cleanup *old_chain_1;
3598 struct displaced_step_inferior_state *displaced;
3600 displaced = get_displaced_stepping_state (inf->pid);
3602 /* Is any thread of this process displaced stepping? If not,
3603 there's nothing else to do. */
3604 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3608 fprintf_unfiltered (gdb_stdlog,
3609 "displaced-stepping in-process while detaching");
3611 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3614 while (!ptid_equal (displaced->step_ptid, null_ptid))
3616 struct cleanup *old_chain_2;
3617 struct execution_control_state ecss;
3618 struct execution_control_state *ecs;
3621 memset (ecs, 0, sizeof (*ecs));
3623 overlay_cache_invalid = 1;
3624 /* Flush target cache before starting to handle each event.
3625 Target was running and cache could be stale. This is just a
3626 heuristic. Running threads may modify target memory, but we
3627 don't get any event. */
3628 target_dcache_invalidate ();
3630 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3633 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3635 /* If an error happens while handling the event, propagate GDB's
3636 knowledge of the executing state to the frontend/user running
3638 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3641 /* Now figure out what to do with the result of the result. */
3642 handle_inferior_event (ecs);
3644 /* No error, don't finish the state yet. */
3645 discard_cleanups (old_chain_2);
3647 /* Breakpoints and watchpoints are not installed on the target
3648 at this point, and signals are passed directly to the
3649 inferior, so this must mean the process is gone. */
3650 if (!ecs->wait_some_more)
3652 discard_cleanups (old_chain_1);
3653 error (_("Program exited while detaching"));
3657 discard_cleanups (old_chain_1);
3660 /* Wait for control to return from inferior to debugger.
3662 If inferior gets a signal, we may decide to start it up again
3663 instead of returning. That is why there is a loop in this function.
3664 When this function actually returns it means the inferior
3665 should be left stopped and GDB should read more commands. */
3668 wait_for_inferior (void)
3670 struct cleanup *old_cleanups;
3671 struct cleanup *thread_state_chain;
3675 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3678 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3681 /* If an error happens while handling the event, propagate GDB's
3682 knowledge of the executing state to the frontend/user running
3684 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3688 struct execution_control_state ecss;
3689 struct execution_control_state *ecs = &ecss;
3690 ptid_t waiton_ptid = minus_one_ptid;
3692 memset (ecs, 0, sizeof (*ecs));
3694 overlay_cache_invalid = 1;
3696 /* Flush target cache before starting to handle each event.
3697 Target was running and cache could be stale. This is just a
3698 heuristic. Running threads may modify target memory, but we
3699 don't get any event. */
3700 target_dcache_invalidate ();
3702 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3705 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3707 /* Now figure out what to do with the result of the result. */
3708 handle_inferior_event (ecs);
3710 if (!ecs->wait_some_more)
3714 /* No error, don't finish the state yet. */
3715 discard_cleanups (thread_state_chain);
3717 do_cleanups (old_cleanups);
3720 /* Cleanup that reinstalls the readline callback handler, if the
3721 target is running in the background. If while handling the target
3722 event something triggered a secondary prompt, like e.g., a
3723 pagination prompt, we'll have removed the callback handler (see
3724 gdb_readline_wrapper_line). Need to do this as we go back to the
3725 event loop, ready to process further input. Note this has no
3726 effect if the handler hasn't actually been removed, because calling
3727 rl_callback_handler_install resets the line buffer, thus losing
3731 reinstall_readline_callback_handler_cleanup (void *arg)
3733 if (!interpreter_async)
3735 /* We're not going back to the top level event loop yet. Don't
3736 install the readline callback, as it'd prep the terminal,
3737 readline-style (raw, noecho) (e.g., --batch). We'll install
3738 it the next time the prompt is displayed, when we're ready
3743 if (async_command_editing_p && !sync_execution)
3744 gdb_rl_callback_handler_reinstall ();
3747 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3748 that's just the event thread. In all-stop, that's all threads. */
3751 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3753 struct thread_info *thr = ecs->event_thread;
3755 if (thr != NULL && thr->thread_fsm != NULL)
3756 thread_fsm_clean_up (thr->thread_fsm);
3760 ALL_NON_EXITED_THREADS (thr)
3762 if (thr->thread_fsm == NULL)
3764 if (thr == ecs->event_thread)
3767 switch_to_thread (thr->ptid);
3768 thread_fsm_clean_up (thr->thread_fsm);
3771 if (ecs->event_thread != NULL)
3772 switch_to_thread (ecs->event_thread->ptid);
3776 /* Asynchronous version of wait_for_inferior. It is called by the
3777 event loop whenever a change of state is detected on the file
3778 descriptor corresponding to the target. It can be called more than
3779 once to complete a single execution command. In such cases we need
3780 to keep the state in a global variable ECSS. If it is the last time
3781 that this function is called for a single execution command, then
3782 report to the user that the inferior has stopped, and do the
3783 necessary cleanups. */
3786 fetch_inferior_event (void *client_data)
3788 struct execution_control_state ecss;
3789 struct execution_control_state *ecs = &ecss;
3790 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3791 struct cleanup *ts_old_chain;
3792 int was_sync = sync_execution;
3794 ptid_t waiton_ptid = minus_one_ptid;
3796 memset (ecs, 0, sizeof (*ecs));
3798 /* End up with readline processing input, if necessary. */
3799 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3801 /* We're handling a live event, so make sure we're doing live
3802 debugging. If we're looking at traceframes while the target is
3803 running, we're going to need to get back to that mode after
3804 handling the event. */
3807 make_cleanup_restore_current_traceframe ();
3808 set_current_traceframe (-1);
3812 /* In non-stop mode, the user/frontend should not notice a thread
3813 switch due to internal events. Make sure we reverse to the
3814 user selected thread and frame after handling the event and
3815 running any breakpoint commands. */
3816 make_cleanup_restore_current_thread ();
3818 overlay_cache_invalid = 1;
3819 /* Flush target cache before starting to handle each event. Target
3820 was running and cache could be stale. This is just a heuristic.
3821 Running threads may modify target memory, but we don't get any
3823 target_dcache_invalidate ();
3825 make_cleanup_restore_integer (&execution_direction);
3826 execution_direction = target_execution_direction ();
3828 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3829 target_can_async_p () ? TARGET_WNOHANG : 0);
3832 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3834 /* If an error happens while handling the event, propagate GDB's
3835 knowledge of the executing state to the frontend/user running
3837 if (!target_is_non_stop_p ())
3838 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3840 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3842 /* Get executed before make_cleanup_restore_current_thread above to apply
3843 still for the thread which has thrown the exception. */
3844 make_bpstat_clear_actions_cleanup ();
3846 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3848 /* Now figure out what to do with the result of the result. */
3849 handle_inferior_event (ecs);
3851 if (!ecs->wait_some_more)
3853 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3854 int should_stop = 1;
3855 struct thread_info *thr = ecs->event_thread;
3856 int should_notify_stop = 1;
3858 delete_just_stopped_threads_infrun_breakpoints ();
3862 struct thread_fsm *thread_fsm = thr->thread_fsm;
3864 if (thread_fsm != NULL)
3865 should_stop = thread_fsm_should_stop (thread_fsm);
3874 clean_up_just_stopped_threads_fsms (ecs);
3876 if (thr != NULL && thr->thread_fsm != NULL)
3879 = thread_fsm_should_notify_stop (thr->thread_fsm);
3882 if (should_notify_stop)
3886 /* We may not find an inferior if this was a process exit. */
3887 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3888 proceeded = normal_stop ();
3892 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3899 /* No error, don't finish the thread states yet. */
3900 discard_cleanups (ts_old_chain);
3902 /* Revert thread and frame. */
3903 do_cleanups (old_chain);
3905 /* If the inferior was in sync execution mode, and now isn't,
3906 restore the prompt (a synchronous execution command has finished,
3907 and we're ready for input). */
3908 if (interpreter_async && was_sync && !sync_execution)
3909 observer_notify_sync_execution_done ();
3913 && exec_done_display_p
3914 && (ptid_equal (inferior_ptid, null_ptid)
3915 || !is_running (inferior_ptid)))
3916 printf_unfiltered (_("completed.\n"));
3919 /* Record the frame and location we're currently stepping through. */
3921 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3923 struct thread_info *tp = inferior_thread ();
3925 tp->control.step_frame_id = get_frame_id (frame);
3926 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3928 tp->current_symtab = sal.symtab;
3929 tp->current_line = sal.line;
3932 /* Clear context switchable stepping state. */
3935 init_thread_stepping_state (struct thread_info *tss)
3937 tss->stepped_breakpoint = 0;
3938 tss->stepping_over_breakpoint = 0;
3939 tss->stepping_over_watchpoint = 0;
3940 tss->step_after_step_resume_breakpoint = 0;
3943 /* Set the cached copy of the last ptid/waitstatus. */
3946 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3948 target_last_wait_ptid = ptid;
3949 target_last_waitstatus = status;
3952 /* Return the cached copy of the last pid/waitstatus returned by
3953 target_wait()/deprecated_target_wait_hook(). The data is actually
3954 cached by handle_inferior_event(), which gets called immediately
3955 after target_wait()/deprecated_target_wait_hook(). */
3958 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3960 *ptidp = target_last_wait_ptid;
3961 *status = target_last_waitstatus;
3965 nullify_last_target_wait_ptid (void)
3967 target_last_wait_ptid = minus_one_ptid;
3970 /* Switch thread contexts. */
3973 context_switch (ptid_t ptid)
3975 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
3977 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3978 target_pid_to_str (inferior_ptid));
3979 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3980 target_pid_to_str (ptid));
3983 switch_to_thread (ptid);
3986 /* If the target can't tell whether we've hit breakpoints
3987 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3988 check whether that could have been caused by a breakpoint. If so,
3989 adjust the PC, per gdbarch_decr_pc_after_break. */
3992 adjust_pc_after_break (struct thread_info *thread,
3993 struct target_waitstatus *ws)
3995 struct regcache *regcache;
3996 struct gdbarch *gdbarch;
3997 struct address_space *aspace;
3998 CORE_ADDR breakpoint_pc, decr_pc;
4000 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4001 we aren't, just return.
4003 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4004 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4005 implemented by software breakpoints should be handled through the normal
4008 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4009 different signals (SIGILL or SIGEMT for instance), but it is less
4010 clear where the PC is pointing afterwards. It may not match
4011 gdbarch_decr_pc_after_break. I don't know any specific target that
4012 generates these signals at breakpoints (the code has been in GDB since at
4013 least 1992) so I can not guess how to handle them here.
4015 In earlier versions of GDB, a target with
4016 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4017 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4018 target with both of these set in GDB history, and it seems unlikely to be
4019 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4021 if (ws->kind != TARGET_WAITKIND_STOPPED)
4024 if (ws->value.sig != GDB_SIGNAL_TRAP)
4027 /* In reverse execution, when a breakpoint is hit, the instruction
4028 under it has already been de-executed. The reported PC always
4029 points at the breakpoint address, so adjusting it further would
4030 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4033 B1 0x08000000 : INSN1
4034 B2 0x08000001 : INSN2
4036 PC -> 0x08000003 : INSN4
4038 Say you're stopped at 0x08000003 as above. Reverse continuing
4039 from that point should hit B2 as below. Reading the PC when the
4040 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4041 been de-executed already.
4043 B1 0x08000000 : INSN1
4044 B2 PC -> 0x08000001 : INSN2
4048 We can't apply the same logic as for forward execution, because
4049 we would wrongly adjust the PC to 0x08000000, since there's a
4050 breakpoint at PC - 1. We'd then report a hit on B1, although
4051 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4053 if (execution_direction == EXEC_REVERSE)
4056 /* If the target can tell whether the thread hit a SW breakpoint,
4057 trust it. Targets that can tell also adjust the PC
4059 if (target_supports_stopped_by_sw_breakpoint ())
4062 /* Note that relying on whether a breakpoint is planted in memory to
4063 determine this can fail. E.g,. the breakpoint could have been
4064 removed since. Or the thread could have been told to step an
4065 instruction the size of a breakpoint instruction, and only
4066 _after_ was a breakpoint inserted at its address. */
4068 /* If this target does not decrement the PC after breakpoints, then
4069 we have nothing to do. */
4070 regcache = get_thread_regcache (thread->ptid);
4071 gdbarch = get_regcache_arch (regcache);
4073 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4077 aspace = get_regcache_aspace (regcache);
4079 /* Find the location where (if we've hit a breakpoint) the
4080 breakpoint would be. */
4081 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4083 /* If the target can't tell whether a software breakpoint triggered,
4084 fallback to figuring it out based on breakpoints we think were
4085 inserted in the target, and on whether the thread was stepped or
4088 /* Check whether there actually is a software breakpoint inserted at
4091 If in non-stop mode, a race condition is possible where we've
4092 removed a breakpoint, but stop events for that breakpoint were
4093 already queued and arrive later. To suppress those spurious
4094 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4095 and retire them after a number of stop events are reported. Note
4096 this is an heuristic and can thus get confused. The real fix is
4097 to get the "stopped by SW BP and needs adjustment" info out of
4098 the target/kernel (and thus never reach here; see above). */
4099 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4100 || (target_is_non_stop_p ()
4101 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4103 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4105 if (record_full_is_used ())
4106 record_full_gdb_operation_disable_set ();
4108 /* When using hardware single-step, a SIGTRAP is reported for both
4109 a completed single-step and a software breakpoint. Need to
4110 differentiate between the two, as the latter needs adjusting
4111 but the former does not.
4113 The SIGTRAP can be due to a completed hardware single-step only if
4114 - we didn't insert software single-step breakpoints
4115 - this thread is currently being stepped
4117 If any of these events did not occur, we must have stopped due
4118 to hitting a software breakpoint, and have to back up to the
4121 As a special case, we could have hardware single-stepped a
4122 software breakpoint. In this case (prev_pc == breakpoint_pc),
4123 we also need to back up to the breakpoint address. */
4125 if (thread_has_single_step_breakpoints_set (thread)
4126 || !currently_stepping (thread)
4127 || (thread->stepped_breakpoint
4128 && thread->prev_pc == breakpoint_pc))
4129 regcache_write_pc (regcache, breakpoint_pc);
4131 do_cleanups (old_cleanups);
4136 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4138 for (frame = get_prev_frame (frame);
4140 frame = get_prev_frame (frame))
4142 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4144 if (get_frame_type (frame) != INLINE_FRAME)
4151 /* Auxiliary function that handles syscall entry/return events.
4152 It returns 1 if the inferior should keep going (and GDB
4153 should ignore the event), or 0 if the event deserves to be
4157 handle_syscall_event (struct execution_control_state *ecs)
4159 struct regcache *regcache;
4162 if (!ptid_equal (ecs->ptid, inferior_ptid))
4163 context_switch (ecs->ptid);
4165 regcache = get_thread_regcache (ecs->ptid);
4166 syscall_number = ecs->ws.value.syscall_number;
4167 stop_pc = regcache_read_pc (regcache);
4169 if (catch_syscall_enabled () > 0
4170 && catching_syscall_number (syscall_number) > 0)
4173 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4176 ecs->event_thread->control.stop_bpstat
4177 = bpstat_stop_status (get_regcache_aspace (regcache),
4178 stop_pc, ecs->ptid, &ecs->ws);
4180 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4182 /* Catchpoint hit. */
4187 /* If no catchpoint triggered for this, then keep going. */
4192 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4195 fill_in_stop_func (struct gdbarch *gdbarch,
4196 struct execution_control_state *ecs)
4198 if (!ecs->stop_func_filled_in)
4200 /* Don't care about return value; stop_func_start and stop_func_name
4201 will both be 0 if it doesn't work. */
4202 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4203 &ecs->stop_func_start, &ecs->stop_func_end);
4204 ecs->stop_func_start
4205 += gdbarch_deprecated_function_start_offset (gdbarch);
4207 if (gdbarch_skip_entrypoint_p (gdbarch))
4208 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4209 ecs->stop_func_start);
4211 ecs->stop_func_filled_in = 1;
4216 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4218 static enum stop_kind
4219 get_inferior_stop_soon (ptid_t ptid)
4221 struct inferior *inf = find_inferior_ptid (ptid);
4223 gdb_assert (inf != NULL);
4224 return inf->control.stop_soon;
4227 /* Wait for one event. Store the resulting waitstatus in WS, and
4228 return the event ptid. */
4231 wait_one (struct target_waitstatus *ws)
4234 ptid_t wait_ptid = minus_one_ptid;
4236 overlay_cache_invalid = 1;
4238 /* Flush target cache before starting to handle each event.
4239 Target was running and cache could be stale. This is just a
4240 heuristic. Running threads may modify target memory, but we
4241 don't get any event. */
4242 target_dcache_invalidate ();
4244 if (deprecated_target_wait_hook)
4245 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4247 event_ptid = target_wait (wait_ptid, ws, 0);
4250 print_target_wait_results (wait_ptid, event_ptid, ws);
4255 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4256 instead of the current thread. */
4257 #define THREAD_STOPPED_BY(REASON) \
4259 thread_stopped_by_ ## REASON (ptid_t ptid) \
4261 struct cleanup *old_chain; \
4264 old_chain = save_inferior_ptid (); \
4265 inferior_ptid = ptid; \
4267 res = target_stopped_by_ ## REASON (); \
4269 do_cleanups (old_chain); \
4274 /* Generate thread_stopped_by_watchpoint. */
4275 THREAD_STOPPED_BY (watchpoint)
4276 /* Generate thread_stopped_by_sw_breakpoint. */
4277 THREAD_STOPPED_BY (sw_breakpoint)
4278 /* Generate thread_stopped_by_hw_breakpoint. */
4279 THREAD_STOPPED_BY (hw_breakpoint)
4281 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4284 switch_to_thread_cleanup (void *ptid_p)
4286 ptid_t ptid = *(ptid_t *) ptid_p;
4288 switch_to_thread (ptid);
4291 /* Save the thread's event and stop reason to process it later. */
4294 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4296 struct regcache *regcache;
4297 struct address_space *aspace;
4303 statstr = target_waitstatus_to_string (ws);
4304 fprintf_unfiltered (gdb_stdlog,
4305 "infrun: saving status %s for %d.%ld.%ld\n",
4307 ptid_get_pid (tp->ptid),
4308 ptid_get_lwp (tp->ptid),
4309 ptid_get_tid (tp->ptid));
4313 /* Record for later. */
4314 tp->suspend.waitstatus = *ws;
4315 tp->suspend.waitstatus_pending_p = 1;
4317 regcache = get_thread_regcache (tp->ptid);
4318 aspace = get_regcache_aspace (regcache);
4320 if (ws->kind == TARGET_WAITKIND_STOPPED
4321 && ws->value.sig == GDB_SIGNAL_TRAP)
4323 CORE_ADDR pc = regcache_read_pc (regcache);
4325 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4327 if (thread_stopped_by_watchpoint (tp->ptid))
4329 tp->suspend.stop_reason
4330 = TARGET_STOPPED_BY_WATCHPOINT;
4332 else if (target_supports_stopped_by_sw_breakpoint ()
4333 && thread_stopped_by_sw_breakpoint (tp->ptid))
4335 tp->suspend.stop_reason
4336 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4338 else if (target_supports_stopped_by_hw_breakpoint ()
4339 && thread_stopped_by_hw_breakpoint (tp->ptid))
4341 tp->suspend.stop_reason
4342 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4344 else if (!target_supports_stopped_by_hw_breakpoint ()
4345 && hardware_breakpoint_inserted_here_p (aspace,
4348 tp->suspend.stop_reason
4349 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4351 else if (!target_supports_stopped_by_sw_breakpoint ()
4352 && software_breakpoint_inserted_here_p (aspace,
4355 tp->suspend.stop_reason
4356 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4358 else if (!thread_has_single_step_breakpoints_set (tp)
4359 && currently_stepping (tp))
4361 tp->suspend.stop_reason
4362 = TARGET_STOPPED_BY_SINGLE_STEP;
4367 /* Stop all threads. */
4370 stop_all_threads (void)
4372 /* We may need multiple passes to discover all threads. */
4376 struct cleanup *old_chain;
4378 gdb_assert (target_is_non_stop_p ());
4381 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4383 entry_ptid = inferior_ptid;
4384 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4386 /* Request threads to stop, and then wait for the stops. Because
4387 threads we already know about can spawn more threads while we're
4388 trying to stop them, and we only learn about new threads when we
4389 update the thread list, do this in a loop, and keep iterating
4390 until two passes find no threads that need to be stopped. */
4391 for (pass = 0; pass < 2; pass++, iterations++)
4394 fprintf_unfiltered (gdb_stdlog,
4395 "infrun: stop_all_threads, pass=%d, "
4396 "iterations=%d\n", pass, iterations);
4400 struct target_waitstatus ws;
4402 struct thread_info *t;
4404 update_thread_list ();
4406 /* Go through all threads looking for threads that we need
4407 to tell the target to stop. */
4408 ALL_NON_EXITED_THREADS (t)
4412 /* If already stopping, don't request a stop again.
4413 We just haven't seen the notification yet. */
4414 if (!t->stop_requested)
4417 fprintf_unfiltered (gdb_stdlog,
4418 "infrun: %s executing, "
4420 target_pid_to_str (t->ptid));
4421 target_stop (t->ptid);
4422 t->stop_requested = 1;
4427 fprintf_unfiltered (gdb_stdlog,
4428 "infrun: %s executing, "
4429 "already stopping\n",
4430 target_pid_to_str (t->ptid));
4433 if (t->stop_requested)
4439 fprintf_unfiltered (gdb_stdlog,
4440 "infrun: %s not executing\n",
4441 target_pid_to_str (t->ptid));
4443 /* The thread may be not executing, but still be
4444 resumed with a pending status to process. */
4452 /* If we find new threads on the second iteration, restart
4453 over. We want to see two iterations in a row with all
4458 event_ptid = wait_one (&ws);
4459 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4461 /* All resumed threads exited. */
4463 else if (ws.kind == TARGET_WAITKIND_EXITED
4464 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4468 ptid_t ptid = pid_to_ptid (ws.value.integer);
4470 fprintf_unfiltered (gdb_stdlog,
4471 "infrun: %s exited while "
4472 "stopping threads\n",
4473 target_pid_to_str (ptid));
4478 t = find_thread_ptid (event_ptid);
4480 t = add_thread (event_ptid);
4482 t->stop_requested = 0;
4485 t->control.may_range_step = 0;
4487 if (ws.kind == TARGET_WAITKIND_STOPPED
4488 && ws.value.sig == GDB_SIGNAL_0)
4490 /* We caught the event that we intended to catch, so
4491 there's no event pending. */
4492 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4493 t->suspend.waitstatus_pending_p = 0;
4495 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4497 /* Add it back to the step-over queue. */
4500 fprintf_unfiltered (gdb_stdlog,
4501 "infrun: displaced-step of %s "
4502 "canceled: adding back to the "
4503 "step-over queue\n",
4504 target_pid_to_str (t->ptid));
4506 t->control.trap_expected = 0;
4507 thread_step_over_chain_enqueue (t);
4512 enum gdb_signal sig;
4513 struct regcache *regcache;
4514 struct address_space *aspace;
4520 statstr = target_waitstatus_to_string (&ws);
4521 fprintf_unfiltered (gdb_stdlog,
4522 "infrun: target_wait %s, saving "
4523 "status for %d.%ld.%ld\n",
4525 ptid_get_pid (t->ptid),
4526 ptid_get_lwp (t->ptid),
4527 ptid_get_tid (t->ptid));
4531 /* Record for later. */
4532 save_waitstatus (t, &ws);
4534 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4535 ? ws.value.sig : GDB_SIGNAL_0);
4537 if (displaced_step_fixup (t->ptid, sig) < 0)
4539 /* Add it back to the step-over queue. */
4540 t->control.trap_expected = 0;
4541 thread_step_over_chain_enqueue (t);
4544 regcache = get_thread_regcache (t->ptid);
4545 t->suspend.stop_pc = regcache_read_pc (regcache);
4549 fprintf_unfiltered (gdb_stdlog,
4550 "infrun: saved stop_pc=%s for %s "
4551 "(currently_stepping=%d)\n",
4552 paddress (target_gdbarch (),
4553 t->suspend.stop_pc),
4554 target_pid_to_str (t->ptid),
4555 currently_stepping (t));
4562 do_cleanups (old_chain);
4565 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4568 /* Given an execution control state that has been freshly filled in by
4569 an event from the inferior, figure out what it means and take
4572 The alternatives are:
4574 1) stop_waiting and return; to really stop and return to the
4577 2) keep_going and return; to wait for the next event (set
4578 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4582 handle_inferior_event_1 (struct execution_control_state *ecs)
4584 enum stop_kind stop_soon;
4586 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4588 /* We had an event in the inferior, but we are not interested in
4589 handling it at this level. The lower layers have already
4590 done what needs to be done, if anything.
4592 One of the possible circumstances for this is when the
4593 inferior produces output for the console. The inferior has
4594 not stopped, and we are ignoring the event. Another possible
4595 circumstance is any event which the lower level knows will be
4596 reported multiple times without an intervening resume. */
4598 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4599 prepare_to_wait (ecs);
4603 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4604 && target_can_async_p () && !sync_execution)
4606 /* There were no unwaited-for children left in the target, but,
4607 we're not synchronously waiting for events either. Just
4608 ignore. Otherwise, if we were running a synchronous
4609 execution command, we need to cancel it and give the user
4610 back the terminal. */
4612 fprintf_unfiltered (gdb_stdlog,
4613 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
4614 prepare_to_wait (ecs);
4618 /* Cache the last pid/waitstatus. */
4619 set_last_target_status (ecs->ptid, ecs->ws);
4621 /* Always clear state belonging to the previous time we stopped. */
4622 stop_stack_dummy = STOP_NONE;
4624 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4626 /* No unwaited-for children left. IOW, all resumed children
4629 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4631 stop_print_frame = 0;
4636 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4637 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4639 ecs->event_thread = find_thread_ptid (ecs->ptid);
4640 /* If it's a new thread, add it to the thread database. */
4641 if (ecs->event_thread == NULL)
4642 ecs->event_thread = add_thread (ecs->ptid);
4644 /* Disable range stepping. If the next step request could use a
4645 range, this will be end up re-enabled then. */
4646 ecs->event_thread->control.may_range_step = 0;
4649 /* Dependent on valid ECS->EVENT_THREAD. */
4650 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4652 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4653 reinit_frame_cache ();
4655 breakpoint_retire_moribund ();
4657 /* First, distinguish signals caused by the debugger from signals
4658 that have to do with the program's own actions. Note that
4659 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4660 on the operating system version. Here we detect when a SIGILL or
4661 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4662 something similar for SIGSEGV, since a SIGSEGV will be generated
4663 when we're trying to execute a breakpoint instruction on a
4664 non-executable stack. This happens for call dummy breakpoints
4665 for architectures like SPARC that place call dummies on the
4667 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4668 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4669 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4670 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4672 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4674 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
4675 regcache_read_pc (regcache)))
4678 fprintf_unfiltered (gdb_stdlog,
4679 "infrun: Treating signal as SIGTRAP\n");
4680 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4684 /* Mark the non-executing threads accordingly. In all-stop, all
4685 threads of all processes are stopped when we get any event
4686 reported. In non-stop mode, only the event thread stops. */
4690 if (!target_is_non_stop_p ())
4691 mark_ptid = minus_one_ptid;
4692 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4693 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4695 /* If we're handling a process exit in non-stop mode, even
4696 though threads haven't been deleted yet, one would think
4697 that there is nothing to do, as threads of the dead process
4698 will be soon deleted, and threads of any other process were
4699 left running. However, on some targets, threads survive a
4700 process exit event. E.g., for the "checkpoint" command,
4701 when the current checkpoint/fork exits, linux-fork.c
4702 automatically switches to another fork from within
4703 target_mourn_inferior, by associating the same
4704 inferior/thread to another fork. We haven't mourned yet at
4705 this point, but we must mark any threads left in the
4706 process as not-executing so that finish_thread_state marks
4707 them stopped (in the user's perspective) if/when we present
4708 the stop to the user. */
4709 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4712 mark_ptid = ecs->ptid;
4714 set_executing (mark_ptid, 0);
4716 /* Likewise the resumed flag. */
4717 set_resumed (mark_ptid, 0);
4720 switch (ecs->ws.kind)
4722 case TARGET_WAITKIND_LOADED:
4724 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4725 if (!ptid_equal (ecs->ptid, inferior_ptid))
4726 context_switch (ecs->ptid);
4727 /* Ignore gracefully during startup of the inferior, as it might
4728 be the shell which has just loaded some objects, otherwise
4729 add the symbols for the newly loaded objects. Also ignore at
4730 the beginning of an attach or remote session; we will query
4731 the full list of libraries once the connection is
4734 stop_soon = get_inferior_stop_soon (ecs->ptid);
4735 if (stop_soon == NO_STOP_QUIETLY)
4737 struct regcache *regcache;
4739 regcache = get_thread_regcache (ecs->ptid);
4741 handle_solib_event ();
4743 ecs->event_thread->control.stop_bpstat
4744 = bpstat_stop_status (get_regcache_aspace (regcache),
4745 stop_pc, ecs->ptid, &ecs->ws);
4747 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4749 /* A catchpoint triggered. */
4750 process_event_stop_test (ecs);
4754 /* If requested, stop when the dynamic linker notifies
4755 gdb of events. This allows the user to get control
4756 and place breakpoints in initializer routines for
4757 dynamically loaded objects (among other things). */
4758 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4759 if (stop_on_solib_events)
4761 /* Make sure we print "Stopped due to solib-event" in
4763 stop_print_frame = 1;
4770 /* If we are skipping through a shell, or through shared library
4771 loading that we aren't interested in, resume the program. If
4772 we're running the program normally, also resume. */
4773 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4775 /* Loading of shared libraries might have changed breakpoint
4776 addresses. Make sure new breakpoints are inserted. */
4777 if (stop_soon == NO_STOP_QUIETLY)
4778 insert_breakpoints ();
4779 resume (GDB_SIGNAL_0);
4780 prepare_to_wait (ecs);
4784 /* But stop if we're attaching or setting up a remote
4786 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4787 || stop_soon == STOP_QUIETLY_REMOTE)
4790 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4795 internal_error (__FILE__, __LINE__,
4796 _("unhandled stop_soon: %d"), (int) stop_soon);
4798 case TARGET_WAITKIND_SPURIOUS:
4800 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4801 if (!ptid_equal (ecs->ptid, inferior_ptid))
4802 context_switch (ecs->ptid);
4803 resume (GDB_SIGNAL_0);
4804 prepare_to_wait (ecs);
4807 case TARGET_WAITKIND_EXITED:
4808 case TARGET_WAITKIND_SIGNALLED:
4811 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4812 fprintf_unfiltered (gdb_stdlog,
4813 "infrun: TARGET_WAITKIND_EXITED\n");
4815 fprintf_unfiltered (gdb_stdlog,
4816 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4819 inferior_ptid = ecs->ptid;
4820 set_current_inferior (find_inferior_ptid (ecs->ptid));
4821 set_current_program_space (current_inferior ()->pspace);
4822 handle_vfork_child_exec_or_exit (0);
4823 target_terminal_ours (); /* Must do this before mourn anyway. */
4825 /* Clearing any previous state of convenience variables. */
4826 clear_exit_convenience_vars ();
4828 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4830 /* Record the exit code in the convenience variable $_exitcode, so
4831 that the user can inspect this again later. */
4832 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4833 (LONGEST) ecs->ws.value.integer);
4835 /* Also record this in the inferior itself. */
4836 current_inferior ()->has_exit_code = 1;
4837 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4839 /* Support the --return-child-result option. */
4840 return_child_result_value = ecs->ws.value.integer;
4842 observer_notify_exited (ecs->ws.value.integer);
4846 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4847 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4849 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4851 /* Set the value of the internal variable $_exitsignal,
4852 which holds the signal uncaught by the inferior. */
4853 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4854 gdbarch_gdb_signal_to_target (gdbarch,
4855 ecs->ws.value.sig));
4859 /* We don't have access to the target's method used for
4860 converting between signal numbers (GDB's internal
4861 representation <-> target's representation).
4862 Therefore, we cannot do a good job at displaying this
4863 information to the user. It's better to just warn
4864 her about it (if infrun debugging is enabled), and
4867 fprintf_filtered (gdb_stdlog, _("\
4868 Cannot fill $_exitsignal with the correct signal number.\n"));
4871 observer_notify_signal_exited (ecs->ws.value.sig);
4874 gdb_flush (gdb_stdout);
4875 target_mourn_inferior ();
4876 stop_print_frame = 0;
4880 /* The following are the only cases in which we keep going;
4881 the above cases end in a continue or goto. */
4882 case TARGET_WAITKIND_FORKED:
4883 case TARGET_WAITKIND_VFORKED:
4886 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4887 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4889 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4892 /* Check whether the inferior is displaced stepping. */
4894 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4895 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4896 struct displaced_step_inferior_state *displaced
4897 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
4899 /* If checking displaced stepping is supported, and thread
4900 ecs->ptid is displaced stepping. */
4901 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
4903 struct inferior *parent_inf
4904 = find_inferior_ptid (ecs->ptid);
4905 struct regcache *child_regcache;
4906 CORE_ADDR parent_pc;
4908 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4909 indicating that the displaced stepping of syscall instruction
4910 has been done. Perform cleanup for parent process here. Note
4911 that this operation also cleans up the child process for vfork,
4912 because their pages are shared. */
4913 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
4914 /* Start a new step-over in another thread if there's one
4918 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4920 /* Restore scratch pad for child process. */
4921 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4924 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4925 the child's PC is also within the scratchpad. Set the child's PC
4926 to the parent's PC value, which has already been fixed up.
4927 FIXME: we use the parent's aspace here, although we're touching
4928 the child, because the child hasn't been added to the inferior
4929 list yet at this point. */
4932 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4934 parent_inf->aspace);
4935 /* Read PC value of parent process. */
4936 parent_pc = regcache_read_pc (regcache);
4938 if (debug_displaced)
4939 fprintf_unfiltered (gdb_stdlog,
4940 "displaced: write child pc from %s to %s\n",
4942 regcache_read_pc (child_regcache)),
4943 paddress (gdbarch, parent_pc));
4945 regcache_write_pc (child_regcache, parent_pc);
4949 if (!ptid_equal (ecs->ptid, inferior_ptid))
4950 context_switch (ecs->ptid);
4952 /* Immediately detach breakpoints from the child before there's
4953 any chance of letting the user delete breakpoints from the
4954 breakpoint lists. If we don't do this early, it's easy to
4955 leave left over traps in the child, vis: "break foo; catch
4956 fork; c; <fork>; del; c; <child calls foo>". We only follow
4957 the fork on the last `continue', and by that time the
4958 breakpoint at "foo" is long gone from the breakpoint table.
4959 If we vforked, then we don't need to unpatch here, since both
4960 parent and child are sharing the same memory pages; we'll
4961 need to unpatch at follow/detach time instead to be certain
4962 that new breakpoints added between catchpoint hit time and
4963 vfork follow are detached. */
4964 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4966 /* This won't actually modify the breakpoint list, but will
4967 physically remove the breakpoints from the child. */
4968 detach_breakpoints (ecs->ws.value.related_pid);
4971 delete_just_stopped_threads_single_step_breakpoints ();
4973 /* In case the event is caught by a catchpoint, remember that
4974 the event is to be followed at the next resume of the thread,
4975 and not immediately. */
4976 ecs->event_thread->pending_follow = ecs->ws;
4978 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4980 ecs->event_thread->control.stop_bpstat
4981 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4982 stop_pc, ecs->ptid, &ecs->ws);
4984 /* If no catchpoint triggered for this, then keep going. Note
4985 that we're interested in knowing the bpstat actually causes a
4986 stop, not just if it may explain the signal. Software
4987 watchpoints, for example, always appear in the bpstat. */
4988 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4994 = (follow_fork_mode_string == follow_fork_mode_child);
4996 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4998 should_resume = follow_fork ();
5001 child = ecs->ws.value.related_pid;
5003 /* In non-stop mode, also resume the other branch. */
5004 if (!detach_fork && (non_stop
5005 || (sched_multi && target_is_non_stop_p ())))
5008 switch_to_thread (parent);
5010 switch_to_thread (child);
5012 ecs->event_thread = inferior_thread ();
5013 ecs->ptid = inferior_ptid;
5018 switch_to_thread (child);
5020 switch_to_thread (parent);
5022 ecs->event_thread = inferior_thread ();
5023 ecs->ptid = inferior_ptid;
5031 process_event_stop_test (ecs);
5034 case TARGET_WAITKIND_VFORK_DONE:
5035 /* Done with the shared memory region. Re-insert breakpoints in
5036 the parent, and keep going. */
5039 fprintf_unfiltered (gdb_stdlog,
5040 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5042 if (!ptid_equal (ecs->ptid, inferior_ptid))
5043 context_switch (ecs->ptid);
5045 current_inferior ()->waiting_for_vfork_done = 0;
5046 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5047 /* This also takes care of reinserting breakpoints in the
5048 previously locked inferior. */
5052 case TARGET_WAITKIND_EXECD:
5054 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5056 if (!ptid_equal (ecs->ptid, inferior_ptid))
5057 context_switch (ecs->ptid);
5059 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5061 /* Do whatever is necessary to the parent branch of the vfork. */
5062 handle_vfork_child_exec_or_exit (1);
5064 /* This causes the eventpoints and symbol table to be reset.
5065 Must do this now, before trying to determine whether to
5067 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5069 /* In follow_exec we may have deleted the original thread and
5070 created a new one. Make sure that the event thread is the
5071 execd thread for that case (this is a nop otherwise). */
5072 ecs->event_thread = inferior_thread ();
5074 ecs->event_thread->control.stop_bpstat
5075 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5076 stop_pc, ecs->ptid, &ecs->ws);
5078 /* Note that this may be referenced from inside
5079 bpstat_stop_status above, through inferior_has_execd. */
5080 xfree (ecs->ws.value.execd_pathname);
5081 ecs->ws.value.execd_pathname = NULL;
5083 /* If no catchpoint triggered for this, then keep going. */
5084 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5086 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5090 process_event_stop_test (ecs);
5093 /* Be careful not to try to gather much state about a thread
5094 that's in a syscall. It's frequently a losing proposition. */
5095 case TARGET_WAITKIND_SYSCALL_ENTRY:
5097 fprintf_unfiltered (gdb_stdlog,
5098 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5099 /* Getting the current syscall number. */
5100 if (handle_syscall_event (ecs) == 0)
5101 process_event_stop_test (ecs);
5104 /* Before examining the threads further, step this thread to
5105 get it entirely out of the syscall. (We get notice of the
5106 event when the thread is just on the verge of exiting a
5107 syscall. Stepping one instruction seems to get it back
5109 case TARGET_WAITKIND_SYSCALL_RETURN:
5111 fprintf_unfiltered (gdb_stdlog,
5112 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5113 if (handle_syscall_event (ecs) == 0)
5114 process_event_stop_test (ecs);
5117 case TARGET_WAITKIND_STOPPED:
5119 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5120 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5121 handle_signal_stop (ecs);
5124 case TARGET_WAITKIND_NO_HISTORY:
5126 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5127 /* Reverse execution: target ran out of history info. */
5129 delete_just_stopped_threads_single_step_breakpoints ();
5130 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5131 observer_notify_no_history ();
5137 /* A wrapper around handle_inferior_event_1, which also makes sure
5138 that all temporary struct value objects that were created during
5139 the handling of the event get deleted at the end. */
5142 handle_inferior_event (struct execution_control_state *ecs)
5144 struct value *mark = value_mark ();
5146 handle_inferior_event_1 (ecs);
5147 /* Purge all temporary values created during the event handling,
5148 as it could be a long time before we return to the command level
5149 where such values would otherwise be purged. */
5150 value_free_to_mark (mark);
5153 /* Restart threads back to what they were trying to do back when we
5154 paused them for an in-line step-over. The EVENT_THREAD thread is
5158 restart_threads (struct thread_info *event_thread)
5160 struct thread_info *tp;
5161 struct thread_info *step_over = NULL;
5163 /* In case the instruction just stepped spawned a new thread. */
5164 update_thread_list ();
5166 ALL_NON_EXITED_THREADS (tp)
5168 if (tp == event_thread)
5171 fprintf_unfiltered (gdb_stdlog,
5172 "infrun: restart threads: "
5173 "[%s] is event thread\n",
5174 target_pid_to_str (tp->ptid));
5178 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5181 fprintf_unfiltered (gdb_stdlog,
5182 "infrun: restart threads: "
5183 "[%s] not meant to be running\n",
5184 target_pid_to_str (tp->ptid));
5191 fprintf_unfiltered (gdb_stdlog,
5192 "infrun: restart threads: [%s] resumed\n",
5193 target_pid_to_str (tp->ptid));
5194 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5198 if (thread_is_in_step_over_chain (tp))
5201 fprintf_unfiltered (gdb_stdlog,
5202 "infrun: restart threads: "
5203 "[%s] needs step-over\n",
5204 target_pid_to_str (tp->ptid));
5205 gdb_assert (!tp->resumed);
5210 if (tp->suspend.waitstatus_pending_p)
5213 fprintf_unfiltered (gdb_stdlog,
5214 "infrun: restart threads: "
5215 "[%s] has pending status\n",
5216 target_pid_to_str (tp->ptid));
5221 /* If some thread needs to start a step-over at this point, it
5222 should still be in the step-over queue, and thus skipped
5224 if (thread_still_needs_step_over (tp))
5226 internal_error (__FILE__, __LINE__,
5227 "thread [%s] needs a step-over, but not in "
5228 "step-over queue\n",
5229 target_pid_to_str (tp->ptid));
5232 if (currently_stepping (tp))
5235 fprintf_unfiltered (gdb_stdlog,
5236 "infrun: restart threads: [%s] was stepping\n",
5237 target_pid_to_str (tp->ptid));
5238 keep_going_stepped_thread (tp);
5242 struct execution_control_state ecss;
5243 struct execution_control_state *ecs = &ecss;
5246 fprintf_unfiltered (gdb_stdlog,
5247 "infrun: restart threads: [%s] continuing\n",
5248 target_pid_to_str (tp->ptid));
5249 reset_ecs (ecs, tp);
5250 switch_to_thread (tp->ptid);
5251 keep_going_pass_signal (ecs);
5256 /* Callback for iterate_over_threads. Find a resumed thread that has
5257 a pending waitstatus. */
5260 resumed_thread_with_pending_status (struct thread_info *tp,
5264 && tp->suspend.waitstatus_pending_p);
5267 /* Called when we get an event that may finish an in-line or
5268 out-of-line (displaced stepping) step-over started previously.
5269 Return true if the event is processed and we should go back to the
5270 event loop; false if the caller should continue processing the
5274 finish_step_over (struct execution_control_state *ecs)
5276 int had_step_over_info;
5278 displaced_step_fixup (ecs->ptid,
5279 ecs->event_thread->suspend.stop_signal);
5281 had_step_over_info = step_over_info_valid_p ();
5283 if (had_step_over_info)
5285 /* If we're stepping over a breakpoint with all threads locked,
5286 then only the thread that was stepped should be reporting
5288 gdb_assert (ecs->event_thread->control.trap_expected);
5290 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5291 clear_step_over_info ();
5294 if (!target_is_non_stop_p ())
5297 /* Start a new step-over in another thread if there's one that
5301 /* If we were stepping over a breakpoint before, and haven't started
5302 a new in-line step-over sequence, then restart all other threads
5303 (except the event thread). We can't do this in all-stop, as then
5304 e.g., we wouldn't be able to issue any other remote packet until
5305 these other threads stop. */
5306 if (had_step_over_info && !step_over_info_valid_p ())
5308 struct thread_info *pending;
5310 /* If we only have threads with pending statuses, the restart
5311 below won't restart any thread and so nothing re-inserts the
5312 breakpoint we just stepped over. But we need it inserted
5313 when we later process the pending events, otherwise if
5314 another thread has a pending event for this breakpoint too,
5315 we'd discard its event (because the breakpoint that
5316 originally caused the event was no longer inserted). */
5317 context_switch (ecs->ptid);
5318 insert_breakpoints ();
5320 restart_threads (ecs->event_thread);
5322 /* If we have events pending, go through handle_inferior_event
5323 again, picking up a pending event at random. This avoids
5324 thread starvation. */
5326 /* But not if we just stepped over a watchpoint in order to let
5327 the instruction execute so we can evaluate its expression.
5328 The set of watchpoints that triggered is recorded in the
5329 breakpoint objects themselves (see bp->watchpoint_triggered).
5330 If we processed another event first, that other event could
5331 clobber this info. */
5332 if (ecs->event_thread->stepping_over_watchpoint)
5335 pending = iterate_over_threads (resumed_thread_with_pending_status,
5337 if (pending != NULL)
5339 struct thread_info *tp = ecs->event_thread;
5340 struct regcache *regcache;
5344 fprintf_unfiltered (gdb_stdlog,
5345 "infrun: found resumed threads with "
5346 "pending events, saving status\n");
5349 gdb_assert (pending != tp);
5351 /* Record the event thread's event for later. */
5352 save_waitstatus (tp, &ecs->ws);
5353 /* This was cleared early, by handle_inferior_event. Set it
5354 so this pending event is considered by
5358 gdb_assert (!tp->executing);
5360 regcache = get_thread_regcache (tp->ptid);
5361 tp->suspend.stop_pc = regcache_read_pc (regcache);
5365 fprintf_unfiltered (gdb_stdlog,
5366 "infrun: saved stop_pc=%s for %s "
5367 "(currently_stepping=%d)\n",
5368 paddress (target_gdbarch (),
5369 tp->suspend.stop_pc),
5370 target_pid_to_str (tp->ptid),
5371 currently_stepping (tp));
5374 /* This in-line step-over finished; clear this so we won't
5375 start a new one. This is what handle_signal_stop would
5376 do, if we returned false. */
5377 tp->stepping_over_breakpoint = 0;
5379 /* Wake up the event loop again. */
5380 mark_async_event_handler (infrun_async_inferior_event_token);
5382 prepare_to_wait (ecs);
5390 /* Come here when the program has stopped with a signal. */
5393 handle_signal_stop (struct execution_control_state *ecs)
5395 struct frame_info *frame;
5396 struct gdbarch *gdbarch;
5397 int stopped_by_watchpoint;
5398 enum stop_kind stop_soon;
5401 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5403 /* Do we need to clean up the state of a thread that has
5404 completed a displaced single-step? (Doing so usually affects
5405 the PC, so do it here, before we set stop_pc.) */
5406 if (finish_step_over (ecs))
5409 /* If we either finished a single-step or hit a breakpoint, but
5410 the user wanted this thread to be stopped, pretend we got a
5411 SIG0 (generic unsignaled stop). */
5412 if (ecs->event_thread->stop_requested
5413 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5414 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5416 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5420 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5421 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5422 struct cleanup *old_chain = save_inferior_ptid ();
5424 inferior_ptid = ecs->ptid;
5426 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5427 paddress (gdbarch, stop_pc));
5428 if (target_stopped_by_watchpoint ())
5432 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5434 if (target_stopped_data_address (¤t_target, &addr))
5435 fprintf_unfiltered (gdb_stdlog,
5436 "infrun: stopped data address = %s\n",
5437 paddress (gdbarch, addr));
5439 fprintf_unfiltered (gdb_stdlog,
5440 "infrun: (no data address available)\n");
5443 do_cleanups (old_chain);
5446 /* This is originated from start_remote(), start_inferior() and
5447 shared libraries hook functions. */
5448 stop_soon = get_inferior_stop_soon (ecs->ptid);
5449 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5451 if (!ptid_equal (ecs->ptid, inferior_ptid))
5452 context_switch (ecs->ptid);
5454 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5455 stop_print_frame = 1;
5460 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5463 if (!ptid_equal (ecs->ptid, inferior_ptid))
5464 context_switch (ecs->ptid);
5466 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5467 stop_print_frame = 0;
5472 /* This originates from attach_command(). We need to overwrite
5473 the stop_signal here, because some kernels don't ignore a
5474 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5475 See more comments in inferior.h. On the other hand, if we
5476 get a non-SIGSTOP, report it to the user - assume the backend
5477 will handle the SIGSTOP if it should show up later.
5479 Also consider that the attach is complete when we see a
5480 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5481 target extended-remote report it instead of a SIGSTOP
5482 (e.g. gdbserver). We already rely on SIGTRAP being our
5483 signal, so this is no exception.
5485 Also consider that the attach is complete when we see a
5486 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5487 the target to stop all threads of the inferior, in case the
5488 low level attach operation doesn't stop them implicitly. If
5489 they weren't stopped implicitly, then the stub will report a
5490 GDB_SIGNAL_0, meaning: stopped for no particular reason
5491 other than GDB's request. */
5492 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5493 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5494 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5495 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5497 stop_print_frame = 1;
5499 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5503 /* See if something interesting happened to the non-current thread. If
5504 so, then switch to that thread. */
5505 if (!ptid_equal (ecs->ptid, inferior_ptid))
5508 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5510 context_switch (ecs->ptid);
5512 if (deprecated_context_hook)
5513 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
5516 /* At this point, get hold of the now-current thread's frame. */
5517 frame = get_current_frame ();
5518 gdbarch = get_frame_arch (frame);
5520 /* Pull the single step breakpoints out of the target. */
5521 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5523 struct regcache *regcache;
5524 struct address_space *aspace;
5527 regcache = get_thread_regcache (ecs->ptid);
5528 aspace = get_regcache_aspace (regcache);
5529 pc = regcache_read_pc (regcache);
5531 /* However, before doing so, if this single-step breakpoint was
5532 actually for another thread, set this thread up for moving
5534 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5537 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5541 fprintf_unfiltered (gdb_stdlog,
5542 "infrun: [%s] hit another thread's "
5543 "single-step breakpoint\n",
5544 target_pid_to_str (ecs->ptid));
5546 ecs->hit_singlestep_breakpoint = 1;
5553 fprintf_unfiltered (gdb_stdlog,
5554 "infrun: [%s] hit its "
5555 "single-step breakpoint\n",
5556 target_pid_to_str (ecs->ptid));
5560 delete_just_stopped_threads_single_step_breakpoints ();
5562 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5563 && ecs->event_thread->control.trap_expected
5564 && ecs->event_thread->stepping_over_watchpoint)
5565 stopped_by_watchpoint = 0;
5567 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5569 /* If necessary, step over this watchpoint. We'll be back to display
5571 if (stopped_by_watchpoint
5572 && (target_have_steppable_watchpoint
5573 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5575 /* At this point, we are stopped at an instruction which has
5576 attempted to write to a piece of memory under control of
5577 a watchpoint. The instruction hasn't actually executed
5578 yet. If we were to evaluate the watchpoint expression
5579 now, we would get the old value, and therefore no change
5580 would seem to have occurred.
5582 In order to make watchpoints work `right', we really need
5583 to complete the memory write, and then evaluate the
5584 watchpoint expression. We do this by single-stepping the
5587 It may not be necessary to disable the watchpoint to step over
5588 it. For example, the PA can (with some kernel cooperation)
5589 single step over a watchpoint without disabling the watchpoint.
5591 It is far more common to need to disable a watchpoint to step
5592 the inferior over it. If we have non-steppable watchpoints,
5593 we must disable the current watchpoint; it's simplest to
5594 disable all watchpoints.
5596 Any breakpoint at PC must also be stepped over -- if there's
5597 one, it will have already triggered before the watchpoint
5598 triggered, and we either already reported it to the user, or
5599 it didn't cause a stop and we called keep_going. In either
5600 case, if there was a breakpoint at PC, we must be trying to
5602 ecs->event_thread->stepping_over_watchpoint = 1;
5607 ecs->event_thread->stepping_over_breakpoint = 0;
5608 ecs->event_thread->stepping_over_watchpoint = 0;
5609 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5610 ecs->event_thread->control.stop_step = 0;
5611 stop_print_frame = 1;
5612 stopped_by_random_signal = 0;
5614 /* Hide inlined functions starting here, unless we just performed stepi or
5615 nexti. After stepi and nexti, always show the innermost frame (not any
5616 inline function call sites). */
5617 if (ecs->event_thread->control.step_range_end != 1)
5619 struct address_space *aspace =
5620 get_regcache_aspace (get_thread_regcache (ecs->ptid));
5622 /* skip_inline_frames is expensive, so we avoid it if we can
5623 determine that the address is one where functions cannot have
5624 been inlined. This improves performance with inferiors that
5625 load a lot of shared libraries, because the solib event
5626 breakpoint is defined as the address of a function (i.e. not
5627 inline). Note that we have to check the previous PC as well
5628 as the current one to catch cases when we have just
5629 single-stepped off a breakpoint prior to reinstating it.
5630 Note that we're assuming that the code we single-step to is
5631 not inline, but that's not definitive: there's nothing
5632 preventing the event breakpoint function from containing
5633 inlined code, and the single-step ending up there. If the
5634 user had set a breakpoint on that inlined code, the missing
5635 skip_inline_frames call would break things. Fortunately
5636 that's an extremely unlikely scenario. */
5637 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5638 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5639 && ecs->event_thread->control.trap_expected
5640 && pc_at_non_inline_function (aspace,
5641 ecs->event_thread->prev_pc,
5644 skip_inline_frames (ecs->ptid);
5646 /* Re-fetch current thread's frame in case that invalidated
5648 frame = get_current_frame ();
5649 gdbarch = get_frame_arch (frame);
5653 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5654 && ecs->event_thread->control.trap_expected
5655 && gdbarch_single_step_through_delay_p (gdbarch)
5656 && currently_stepping (ecs->event_thread))
5658 /* We're trying to step off a breakpoint. Turns out that we're
5659 also on an instruction that needs to be stepped multiple
5660 times before it's been fully executing. E.g., architectures
5661 with a delay slot. It needs to be stepped twice, once for
5662 the instruction and once for the delay slot. */
5663 int step_through_delay
5664 = gdbarch_single_step_through_delay (gdbarch, frame);
5666 if (debug_infrun && step_through_delay)
5667 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5668 if (ecs->event_thread->control.step_range_end == 0
5669 && step_through_delay)
5671 /* The user issued a continue when stopped at a breakpoint.
5672 Set up for another trap and get out of here. */
5673 ecs->event_thread->stepping_over_breakpoint = 1;
5677 else if (step_through_delay)
5679 /* The user issued a step when stopped at a breakpoint.
5680 Maybe we should stop, maybe we should not - the delay
5681 slot *might* correspond to a line of source. In any
5682 case, don't decide that here, just set
5683 ecs->stepping_over_breakpoint, making sure we
5684 single-step again before breakpoints are re-inserted. */
5685 ecs->event_thread->stepping_over_breakpoint = 1;
5689 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5690 handles this event. */
5691 ecs->event_thread->control.stop_bpstat
5692 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5693 stop_pc, ecs->ptid, &ecs->ws);
5695 /* Following in case break condition called a
5697 stop_print_frame = 1;
5699 /* This is where we handle "moribund" watchpoints. Unlike
5700 software breakpoints traps, hardware watchpoint traps are
5701 always distinguishable from random traps. If no high-level
5702 watchpoint is associated with the reported stop data address
5703 anymore, then the bpstat does not explain the signal ---
5704 simply make sure to ignore it if `stopped_by_watchpoint' is
5708 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5709 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5711 && stopped_by_watchpoint)
5712 fprintf_unfiltered (gdb_stdlog,
5713 "infrun: no user watchpoint explains "
5714 "watchpoint SIGTRAP, ignoring\n");
5716 /* NOTE: cagney/2003-03-29: These checks for a random signal
5717 at one stage in the past included checks for an inferior
5718 function call's call dummy's return breakpoint. The original
5719 comment, that went with the test, read:
5721 ``End of a stack dummy. Some systems (e.g. Sony news) give
5722 another signal besides SIGTRAP, so check here as well as
5725 If someone ever tries to get call dummys on a
5726 non-executable stack to work (where the target would stop
5727 with something like a SIGSEGV), then those tests might need
5728 to be re-instated. Given, however, that the tests were only
5729 enabled when momentary breakpoints were not being used, I
5730 suspect that it won't be the case.
5732 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5733 be necessary for call dummies on a non-executable stack on
5736 /* See if the breakpoints module can explain the signal. */
5738 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5739 ecs->event_thread->suspend.stop_signal);
5741 /* Maybe this was a trap for a software breakpoint that has since
5743 if (random_signal && target_stopped_by_sw_breakpoint ())
5745 if (program_breakpoint_here_p (gdbarch, stop_pc))
5747 struct regcache *regcache;
5750 /* Re-adjust PC to what the program would see if GDB was not
5752 regcache = get_thread_regcache (ecs->event_thread->ptid);
5753 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5756 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
5758 if (record_full_is_used ())
5759 record_full_gdb_operation_disable_set ();
5761 regcache_write_pc (regcache, stop_pc + decr_pc);
5763 do_cleanups (old_cleanups);
5768 /* A delayed software breakpoint event. Ignore the trap. */
5770 fprintf_unfiltered (gdb_stdlog,
5771 "infrun: delayed software breakpoint "
5772 "trap, ignoring\n");
5777 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5778 has since been removed. */
5779 if (random_signal && target_stopped_by_hw_breakpoint ())
5781 /* A delayed hardware breakpoint event. Ignore the trap. */
5783 fprintf_unfiltered (gdb_stdlog,
5784 "infrun: delayed hardware breakpoint/watchpoint "
5785 "trap, ignoring\n");
5789 /* If not, perhaps stepping/nexting can. */
5791 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5792 && currently_stepping (ecs->event_thread));
5794 /* Perhaps the thread hit a single-step breakpoint of _another_
5795 thread. Single-step breakpoints are transparent to the
5796 breakpoints module. */
5798 random_signal = !ecs->hit_singlestep_breakpoint;
5800 /* No? Perhaps we got a moribund watchpoint. */
5802 random_signal = !stopped_by_watchpoint;
5804 /* For the program's own signals, act according to
5805 the signal handling tables. */
5809 /* Signal not for debugging purposes. */
5810 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5811 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5814 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5815 gdb_signal_to_symbol_string (stop_signal));
5817 stopped_by_random_signal = 1;
5819 /* Always stop on signals if we're either just gaining control
5820 of the program, or the user explicitly requested this thread
5821 to remain stopped. */
5822 if (stop_soon != NO_STOP_QUIETLY
5823 || ecs->event_thread->stop_requested
5825 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5831 /* Notify observers the signal has "handle print" set. Note we
5832 returned early above if stopping; normal_stop handles the
5833 printing in that case. */
5834 if (signal_print[ecs->event_thread->suspend.stop_signal])
5836 /* The signal table tells us to print about this signal. */
5837 target_terminal_ours_for_output ();
5838 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
5839 target_terminal_inferior ();
5842 /* Clear the signal if it should not be passed. */
5843 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5844 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5846 if (ecs->event_thread->prev_pc == stop_pc
5847 && ecs->event_thread->control.trap_expected
5848 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5852 /* We were just starting a new sequence, attempting to
5853 single-step off of a breakpoint and expecting a SIGTRAP.
5854 Instead this signal arrives. This signal will take us out
5855 of the stepping range so GDB needs to remember to, when
5856 the signal handler returns, resume stepping off that
5858 /* To simplify things, "continue" is forced to use the same
5859 code paths as single-step - set a breakpoint at the
5860 signal return address and then, once hit, step off that
5863 fprintf_unfiltered (gdb_stdlog,
5864 "infrun: signal arrived while stepping over "
5867 was_in_line = step_over_info_valid_p ();
5868 clear_step_over_info ();
5869 insert_hp_step_resume_breakpoint_at_frame (frame);
5870 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5871 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5872 ecs->event_thread->control.trap_expected = 0;
5874 if (target_is_non_stop_p ())
5876 /* Either "set non-stop" is "on", or the target is
5877 always in non-stop mode. In this case, we have a bit
5878 more work to do. Resume the current thread, and if
5879 we had paused all threads, restart them while the
5880 signal handler runs. */
5885 restart_threads (ecs->event_thread);
5887 else if (debug_infrun)
5889 fprintf_unfiltered (gdb_stdlog,
5890 "infrun: no need to restart threads\n");
5895 /* If we were nexting/stepping some other thread, switch to
5896 it, so that we don't continue it, losing control. */
5897 if (!switch_back_to_stepped_thread (ecs))
5902 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5903 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
5904 || ecs->event_thread->control.step_range_end == 1)
5905 && frame_id_eq (get_stack_frame_id (frame),
5906 ecs->event_thread->control.step_stack_frame_id)
5907 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5909 /* The inferior is about to take a signal that will take it
5910 out of the single step range. Set a breakpoint at the
5911 current PC (which is presumably where the signal handler
5912 will eventually return) and then allow the inferior to
5915 Note that this is only needed for a signal delivered
5916 while in the single-step range. Nested signals aren't a
5917 problem as they eventually all return. */
5919 fprintf_unfiltered (gdb_stdlog,
5920 "infrun: signal may take us out of "
5921 "single-step range\n");
5923 clear_step_over_info ();
5924 insert_hp_step_resume_breakpoint_at_frame (frame);
5925 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5926 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5927 ecs->event_thread->control.trap_expected = 0;
5932 /* Note: step_resume_breakpoint may be non-NULL. This occures
5933 when either there's a nested signal, or when there's a
5934 pending signal enabled just as the signal handler returns
5935 (leaving the inferior at the step-resume-breakpoint without
5936 actually executing it). Either way continue until the
5937 breakpoint is really hit. */
5939 if (!switch_back_to_stepped_thread (ecs))
5942 fprintf_unfiltered (gdb_stdlog,
5943 "infrun: random signal, keep going\n");
5950 process_event_stop_test (ecs);
5953 /* Come here when we've got some debug event / signal we can explain
5954 (IOW, not a random signal), and test whether it should cause a
5955 stop, or whether we should resume the inferior (transparently).
5956 E.g., could be a breakpoint whose condition evaluates false; we
5957 could be still stepping within the line; etc. */
5960 process_event_stop_test (struct execution_control_state *ecs)
5962 struct symtab_and_line stop_pc_sal;
5963 struct frame_info *frame;
5964 struct gdbarch *gdbarch;
5965 CORE_ADDR jmp_buf_pc;
5966 struct bpstat_what what;
5968 /* Handle cases caused by hitting a breakpoint. */
5970 frame = get_current_frame ();
5971 gdbarch = get_frame_arch (frame);
5973 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
5975 if (what.call_dummy)
5977 stop_stack_dummy = what.call_dummy;
5980 /* A few breakpoint types have callbacks associated (e.g.,
5981 bp_jit_event). Run them now. */
5982 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
5984 /* If we hit an internal event that triggers symbol changes, the
5985 current frame will be invalidated within bpstat_what (e.g., if we
5986 hit an internal solib event). Re-fetch it. */
5987 frame = get_current_frame ();
5988 gdbarch = get_frame_arch (frame);
5990 switch (what.main_action)
5992 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
5993 /* If we hit the breakpoint at longjmp while stepping, we
5994 install a momentary breakpoint at the target of the
5998 fprintf_unfiltered (gdb_stdlog,
5999 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6001 ecs->event_thread->stepping_over_breakpoint = 1;
6003 if (what.is_longjmp)
6005 struct value *arg_value;
6007 /* If we set the longjmp breakpoint via a SystemTap probe,
6008 then use it to extract the arguments. The destination PC
6009 is the third argument to the probe. */
6010 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6013 jmp_buf_pc = value_as_address (arg_value);
6014 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6016 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6017 || !gdbarch_get_longjmp_target (gdbarch,
6018 frame, &jmp_buf_pc))
6021 fprintf_unfiltered (gdb_stdlog,
6022 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6023 "(!gdbarch_get_longjmp_target)\n");
6028 /* Insert a breakpoint at resume address. */
6029 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6032 check_exception_resume (ecs, frame);
6036 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6038 struct frame_info *init_frame;
6040 /* There are several cases to consider.
6042 1. The initiating frame no longer exists. In this case we
6043 must stop, because the exception or longjmp has gone too
6046 2. The initiating frame exists, and is the same as the
6047 current frame. We stop, because the exception or longjmp
6050 3. The initiating frame exists and is different from the
6051 current frame. This means the exception or longjmp has
6052 been caught beneath the initiating frame, so keep going.
6054 4. longjmp breakpoint has been placed just to protect
6055 against stale dummy frames and user is not interested in
6056 stopping around longjmps. */
6059 fprintf_unfiltered (gdb_stdlog,
6060 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6062 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6064 delete_exception_resume_breakpoint (ecs->event_thread);
6066 if (what.is_longjmp)
6068 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6070 if (!frame_id_p (ecs->event_thread->initiating_frame))
6078 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6082 struct frame_id current_id
6083 = get_frame_id (get_current_frame ());
6084 if (frame_id_eq (current_id,
6085 ecs->event_thread->initiating_frame))
6087 /* Case 2. Fall through. */
6097 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6099 delete_step_resume_breakpoint (ecs->event_thread);
6101 end_stepping_range (ecs);
6105 case BPSTAT_WHAT_SINGLE:
6107 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6108 ecs->event_thread->stepping_over_breakpoint = 1;
6109 /* Still need to check other stuff, at least the case where we
6110 are stepping and step out of the right range. */
6113 case BPSTAT_WHAT_STEP_RESUME:
6115 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6117 delete_step_resume_breakpoint (ecs->event_thread);
6118 if (ecs->event_thread->control.proceed_to_finish
6119 && execution_direction == EXEC_REVERSE)
6121 struct thread_info *tp = ecs->event_thread;
6123 /* We are finishing a function in reverse, and just hit the
6124 step-resume breakpoint at the start address of the
6125 function, and we're almost there -- just need to back up
6126 by one more single-step, which should take us back to the
6128 tp->control.step_range_start = tp->control.step_range_end = 1;
6132 fill_in_stop_func (gdbarch, ecs);
6133 if (stop_pc == ecs->stop_func_start
6134 && execution_direction == EXEC_REVERSE)
6136 /* We are stepping over a function call in reverse, and just
6137 hit the step-resume breakpoint at the start address of
6138 the function. Go back to single-stepping, which should
6139 take us back to the function call. */
6140 ecs->event_thread->stepping_over_breakpoint = 1;
6146 case BPSTAT_WHAT_STOP_NOISY:
6148 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6149 stop_print_frame = 1;
6151 /* Assume the thread stopped for a breapoint. We'll still check
6152 whether a/the breakpoint is there when the thread is next
6154 ecs->event_thread->stepping_over_breakpoint = 1;
6159 case BPSTAT_WHAT_STOP_SILENT:
6161 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6162 stop_print_frame = 0;
6164 /* Assume the thread stopped for a breapoint. We'll still check
6165 whether a/the breakpoint is there when the thread is next
6167 ecs->event_thread->stepping_over_breakpoint = 1;
6171 case BPSTAT_WHAT_HP_STEP_RESUME:
6173 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6175 delete_step_resume_breakpoint (ecs->event_thread);
6176 if (ecs->event_thread->step_after_step_resume_breakpoint)
6178 /* Back when the step-resume breakpoint was inserted, we
6179 were trying to single-step off a breakpoint. Go back to
6181 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6182 ecs->event_thread->stepping_over_breakpoint = 1;
6188 case BPSTAT_WHAT_KEEP_CHECKING:
6192 /* If we stepped a permanent breakpoint and we had a high priority
6193 step-resume breakpoint for the address we stepped, but we didn't
6194 hit it, then we must have stepped into the signal handler. The
6195 step-resume was only necessary to catch the case of _not_
6196 stepping into the handler, so delete it, and fall through to
6197 checking whether the step finished. */
6198 if (ecs->event_thread->stepped_breakpoint)
6200 struct breakpoint *sr_bp
6201 = ecs->event_thread->control.step_resume_breakpoint;
6204 && sr_bp->loc->permanent
6205 && sr_bp->type == bp_hp_step_resume
6206 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6209 fprintf_unfiltered (gdb_stdlog,
6210 "infrun: stepped permanent breakpoint, stopped in "
6212 delete_step_resume_breakpoint (ecs->event_thread);
6213 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6217 /* We come here if we hit a breakpoint but should not stop for it.
6218 Possibly we also were stepping and should stop for that. So fall
6219 through and test for stepping. But, if not stepping, do not
6222 /* In all-stop mode, if we're currently stepping but have stopped in
6223 some other thread, we need to switch back to the stepped thread. */
6224 if (switch_back_to_stepped_thread (ecs))
6227 if (ecs->event_thread->control.step_resume_breakpoint)
6230 fprintf_unfiltered (gdb_stdlog,
6231 "infrun: step-resume breakpoint is inserted\n");
6233 /* Having a step-resume breakpoint overrides anything
6234 else having to do with stepping commands until
6235 that breakpoint is reached. */
6240 if (ecs->event_thread->control.step_range_end == 0)
6243 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6244 /* Likewise if we aren't even stepping. */
6249 /* Re-fetch current thread's frame in case the code above caused
6250 the frame cache to be re-initialized, making our FRAME variable
6251 a dangling pointer. */
6252 frame = get_current_frame ();
6253 gdbarch = get_frame_arch (frame);
6254 fill_in_stop_func (gdbarch, ecs);
6256 /* If stepping through a line, keep going if still within it.
6258 Note that step_range_end is the address of the first instruction
6259 beyond the step range, and NOT the address of the last instruction
6262 Note also that during reverse execution, we may be stepping
6263 through a function epilogue and therefore must detect when
6264 the current-frame changes in the middle of a line. */
6266 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6267 && (execution_direction != EXEC_REVERSE
6268 || frame_id_eq (get_frame_id (frame),
6269 ecs->event_thread->control.step_frame_id)))
6273 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6274 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6275 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6277 /* Tentatively re-enable range stepping; `resume' disables it if
6278 necessary (e.g., if we're stepping over a breakpoint or we
6279 have software watchpoints). */
6280 ecs->event_thread->control.may_range_step = 1;
6282 /* When stepping backward, stop at beginning of line range
6283 (unless it's the function entry point, in which case
6284 keep going back to the call point). */
6285 if (stop_pc == ecs->event_thread->control.step_range_start
6286 && stop_pc != ecs->stop_func_start
6287 && execution_direction == EXEC_REVERSE)
6288 end_stepping_range (ecs);
6295 /* We stepped out of the stepping range. */
6297 /* If we are stepping at the source level and entered the runtime
6298 loader dynamic symbol resolution code...
6300 EXEC_FORWARD: we keep on single stepping until we exit the run
6301 time loader code and reach the callee's address.
6303 EXEC_REVERSE: we've already executed the callee (backward), and
6304 the runtime loader code is handled just like any other
6305 undebuggable function call. Now we need only keep stepping
6306 backward through the trampoline code, and that's handled further
6307 down, so there is nothing for us to do here. */
6309 if (execution_direction != EXEC_REVERSE
6310 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6311 && in_solib_dynsym_resolve_code (stop_pc))
6313 CORE_ADDR pc_after_resolver =
6314 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6317 fprintf_unfiltered (gdb_stdlog,
6318 "infrun: stepped into dynsym resolve code\n");
6320 if (pc_after_resolver)
6322 /* Set up a step-resume breakpoint at the address
6323 indicated by SKIP_SOLIB_RESOLVER. */
6324 struct symtab_and_line sr_sal;
6327 sr_sal.pc = pc_after_resolver;
6328 sr_sal.pspace = get_frame_program_space (frame);
6330 insert_step_resume_breakpoint_at_sal (gdbarch,
6331 sr_sal, null_frame_id);
6338 if (ecs->event_thread->control.step_range_end != 1
6339 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6340 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6341 && get_frame_type (frame) == SIGTRAMP_FRAME)
6344 fprintf_unfiltered (gdb_stdlog,
6345 "infrun: stepped into signal trampoline\n");
6346 /* The inferior, while doing a "step" or "next", has ended up in
6347 a signal trampoline (either by a signal being delivered or by
6348 the signal handler returning). Just single-step until the
6349 inferior leaves the trampoline (either by calling the handler
6355 /* If we're in the return path from a shared library trampoline,
6356 we want to proceed through the trampoline when stepping. */
6357 /* macro/2012-04-25: This needs to come before the subroutine
6358 call check below as on some targets return trampolines look
6359 like subroutine calls (MIPS16 return thunks). */
6360 if (gdbarch_in_solib_return_trampoline (gdbarch,
6361 stop_pc, ecs->stop_func_name)
6362 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6364 /* Determine where this trampoline returns. */
6365 CORE_ADDR real_stop_pc;
6367 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6370 fprintf_unfiltered (gdb_stdlog,
6371 "infrun: stepped into solib return tramp\n");
6373 /* Only proceed through if we know where it's going. */
6376 /* And put the step-breakpoint there and go until there. */
6377 struct symtab_and_line sr_sal;
6379 init_sal (&sr_sal); /* initialize to zeroes */
6380 sr_sal.pc = real_stop_pc;
6381 sr_sal.section = find_pc_overlay (sr_sal.pc);
6382 sr_sal.pspace = get_frame_program_space (frame);
6384 /* Do not specify what the fp should be when we stop since
6385 on some machines the prologue is where the new fp value
6387 insert_step_resume_breakpoint_at_sal (gdbarch,
6388 sr_sal, null_frame_id);
6390 /* Restart without fiddling with the step ranges or
6397 /* Check for subroutine calls. The check for the current frame
6398 equalling the step ID is not necessary - the check of the
6399 previous frame's ID is sufficient - but it is a common case and
6400 cheaper than checking the previous frame's ID.
6402 NOTE: frame_id_eq will never report two invalid frame IDs as
6403 being equal, so to get into this block, both the current and
6404 previous frame must have valid frame IDs. */
6405 /* The outer_frame_id check is a heuristic to detect stepping
6406 through startup code. If we step over an instruction which
6407 sets the stack pointer from an invalid value to a valid value,
6408 we may detect that as a subroutine call from the mythical
6409 "outermost" function. This could be fixed by marking
6410 outermost frames as !stack_p,code_p,special_p. Then the
6411 initial outermost frame, before sp was valid, would
6412 have code_addr == &_start. See the comment in frame_id_eq
6414 if (!frame_id_eq (get_stack_frame_id (frame),
6415 ecs->event_thread->control.step_stack_frame_id)
6416 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6417 ecs->event_thread->control.step_stack_frame_id)
6418 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6420 || (ecs->event_thread->control.step_start_function
6421 != find_pc_function (stop_pc)))))
6423 CORE_ADDR real_stop_pc;
6426 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6428 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6430 /* I presume that step_over_calls is only 0 when we're
6431 supposed to be stepping at the assembly language level
6432 ("stepi"). Just stop. */
6433 /* And this works the same backward as frontward. MVS */
6434 end_stepping_range (ecs);
6438 /* Reverse stepping through solib trampolines. */
6440 if (execution_direction == EXEC_REVERSE
6441 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6442 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6443 || (ecs->stop_func_start == 0
6444 && in_solib_dynsym_resolve_code (stop_pc))))
6446 /* Any solib trampoline code can be handled in reverse
6447 by simply continuing to single-step. We have already
6448 executed the solib function (backwards), and a few
6449 steps will take us back through the trampoline to the
6455 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6457 /* We're doing a "next".
6459 Normal (forward) execution: set a breakpoint at the
6460 callee's return address (the address at which the caller
6463 Reverse (backward) execution. set the step-resume
6464 breakpoint at the start of the function that we just
6465 stepped into (backwards), and continue to there. When we
6466 get there, we'll need to single-step back to the caller. */
6468 if (execution_direction == EXEC_REVERSE)
6470 /* If we're already at the start of the function, we've either
6471 just stepped backward into a single instruction function,
6472 or stepped back out of a signal handler to the first instruction
6473 of the function. Just keep going, which will single-step back
6475 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6477 struct symtab_and_line sr_sal;
6479 /* Normal function call return (static or dynamic). */
6481 sr_sal.pc = ecs->stop_func_start;
6482 sr_sal.pspace = get_frame_program_space (frame);
6483 insert_step_resume_breakpoint_at_sal (gdbarch,
6484 sr_sal, null_frame_id);
6488 insert_step_resume_breakpoint_at_caller (frame);
6494 /* If we are in a function call trampoline (a stub between the
6495 calling routine and the real function), locate the real
6496 function. That's what tells us (a) whether we want to step
6497 into it at all, and (b) what prologue we want to run to the
6498 end of, if we do step into it. */
6499 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6500 if (real_stop_pc == 0)
6501 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6502 if (real_stop_pc != 0)
6503 ecs->stop_func_start = real_stop_pc;
6505 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6507 struct symtab_and_line sr_sal;
6510 sr_sal.pc = ecs->stop_func_start;
6511 sr_sal.pspace = get_frame_program_space (frame);
6513 insert_step_resume_breakpoint_at_sal (gdbarch,
6514 sr_sal, null_frame_id);
6519 /* If we have line number information for the function we are
6520 thinking of stepping into and the function isn't on the skip
6523 If there are several symtabs at that PC (e.g. with include
6524 files), just want to know whether *any* of them have line
6525 numbers. find_pc_line handles this. */
6527 struct symtab_and_line tmp_sal;
6529 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6530 if (tmp_sal.line != 0
6531 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6534 if (execution_direction == EXEC_REVERSE)
6535 handle_step_into_function_backward (gdbarch, ecs);
6537 handle_step_into_function (gdbarch, ecs);
6542 /* If we have no line number and the step-stop-if-no-debug is
6543 set, we stop the step so that the user has a chance to switch
6544 in assembly mode. */
6545 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6546 && step_stop_if_no_debug)
6548 end_stepping_range (ecs);
6552 if (execution_direction == EXEC_REVERSE)
6554 /* If we're already at the start of the function, we've either just
6555 stepped backward into a single instruction function without line
6556 number info, or stepped back out of a signal handler to the first
6557 instruction of the function without line number info. Just keep
6558 going, which will single-step back to the caller. */
6559 if (ecs->stop_func_start != stop_pc)
6561 /* Set a breakpoint at callee's start address.
6562 From there we can step once and be back in the caller. */
6563 struct symtab_and_line sr_sal;
6566 sr_sal.pc = ecs->stop_func_start;
6567 sr_sal.pspace = get_frame_program_space (frame);
6568 insert_step_resume_breakpoint_at_sal (gdbarch,
6569 sr_sal, null_frame_id);
6573 /* Set a breakpoint at callee's return address (the address
6574 at which the caller will resume). */
6575 insert_step_resume_breakpoint_at_caller (frame);
6581 /* Reverse stepping through solib trampolines. */
6583 if (execution_direction == EXEC_REVERSE
6584 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6586 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6587 || (ecs->stop_func_start == 0
6588 && in_solib_dynsym_resolve_code (stop_pc)))
6590 /* Any solib trampoline code can be handled in reverse
6591 by simply continuing to single-step. We have already
6592 executed the solib function (backwards), and a few
6593 steps will take us back through the trampoline to the
6598 else if (in_solib_dynsym_resolve_code (stop_pc))
6600 /* Stepped backward into the solib dynsym resolver.
6601 Set a breakpoint at its start and continue, then
6602 one more step will take us out. */
6603 struct symtab_and_line sr_sal;
6606 sr_sal.pc = ecs->stop_func_start;
6607 sr_sal.pspace = get_frame_program_space (frame);
6608 insert_step_resume_breakpoint_at_sal (gdbarch,
6609 sr_sal, null_frame_id);
6615 stop_pc_sal = find_pc_line (stop_pc, 0);
6617 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6618 the trampoline processing logic, however, there are some trampolines
6619 that have no names, so we should do trampoline handling first. */
6620 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6621 && ecs->stop_func_name == NULL
6622 && stop_pc_sal.line == 0)
6625 fprintf_unfiltered (gdb_stdlog,
6626 "infrun: stepped into undebuggable function\n");
6628 /* The inferior just stepped into, or returned to, an
6629 undebuggable function (where there is no debugging information
6630 and no line number corresponding to the address where the
6631 inferior stopped). Since we want to skip this kind of code,
6632 we keep going until the inferior returns from this
6633 function - unless the user has asked us not to (via
6634 set step-mode) or we no longer know how to get back
6635 to the call site. */
6636 if (step_stop_if_no_debug
6637 || !frame_id_p (frame_unwind_caller_id (frame)))
6639 /* If we have no line number and the step-stop-if-no-debug
6640 is set, we stop the step so that the user has a chance to
6641 switch in assembly mode. */
6642 end_stepping_range (ecs);
6647 /* Set a breakpoint at callee's return address (the address
6648 at which the caller will resume). */
6649 insert_step_resume_breakpoint_at_caller (frame);
6655 if (ecs->event_thread->control.step_range_end == 1)
6657 /* It is stepi or nexti. We always want to stop stepping after
6660 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6661 end_stepping_range (ecs);
6665 if (stop_pc_sal.line == 0)
6667 /* We have no line number information. That means to stop
6668 stepping (does this always happen right after one instruction,
6669 when we do "s" in a function with no line numbers,
6670 or can this happen as a result of a return or longjmp?). */
6672 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6673 end_stepping_range (ecs);
6677 /* Look for "calls" to inlined functions, part one. If the inline
6678 frame machinery detected some skipped call sites, we have entered
6679 a new inline function. */
6681 if (frame_id_eq (get_frame_id (get_current_frame ()),
6682 ecs->event_thread->control.step_frame_id)
6683 && inline_skipped_frames (ecs->ptid))
6685 struct symtab_and_line call_sal;
6688 fprintf_unfiltered (gdb_stdlog,
6689 "infrun: stepped into inlined function\n");
6691 find_frame_sal (get_current_frame (), &call_sal);
6693 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6695 /* For "step", we're going to stop. But if the call site
6696 for this inlined function is on the same source line as
6697 we were previously stepping, go down into the function
6698 first. Otherwise stop at the call site. */
6700 if (call_sal.line == ecs->event_thread->current_line
6701 && call_sal.symtab == ecs->event_thread->current_symtab)
6702 step_into_inline_frame (ecs->ptid);
6704 end_stepping_range (ecs);
6709 /* For "next", we should stop at the call site if it is on a
6710 different source line. Otherwise continue through the
6711 inlined function. */
6712 if (call_sal.line == ecs->event_thread->current_line
6713 && call_sal.symtab == ecs->event_thread->current_symtab)
6716 end_stepping_range (ecs);
6721 /* Look for "calls" to inlined functions, part two. If we are still
6722 in the same real function we were stepping through, but we have
6723 to go further up to find the exact frame ID, we are stepping
6724 through a more inlined call beyond its call site. */
6726 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6727 && !frame_id_eq (get_frame_id (get_current_frame ()),
6728 ecs->event_thread->control.step_frame_id)
6729 && stepped_in_from (get_current_frame (),
6730 ecs->event_thread->control.step_frame_id))
6733 fprintf_unfiltered (gdb_stdlog,
6734 "infrun: stepping through inlined function\n");
6736 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6739 end_stepping_range (ecs);
6743 if ((stop_pc == stop_pc_sal.pc)
6744 && (ecs->event_thread->current_line != stop_pc_sal.line
6745 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6747 /* We are at the start of a different line. So stop. Note that
6748 we don't stop if we step into the middle of a different line.
6749 That is said to make things like for (;;) statements work
6752 fprintf_unfiltered (gdb_stdlog,
6753 "infrun: stepped to a different line\n");
6754 end_stepping_range (ecs);
6758 /* We aren't done stepping.
6760 Optimize by setting the stepping range to the line.
6761 (We might not be in the original line, but if we entered a
6762 new line in mid-statement, we continue stepping. This makes
6763 things like for(;;) statements work better.) */
6765 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6766 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6767 ecs->event_thread->control.may_range_step = 1;
6768 set_step_info (frame, stop_pc_sal);
6771 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6775 /* In all-stop mode, if we're currently stepping but have stopped in
6776 some other thread, we may need to switch back to the stepped
6777 thread. Returns true we set the inferior running, false if we left
6778 it stopped (and the event needs further processing). */
6781 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6783 if (!target_is_non_stop_p ())
6785 struct thread_info *tp;
6786 struct thread_info *stepping_thread;
6788 /* If any thread is blocked on some internal breakpoint, and we
6789 simply need to step over that breakpoint to get it going
6790 again, do that first. */
6792 /* However, if we see an event for the stepping thread, then we
6793 know all other threads have been moved past their breakpoints
6794 already. Let the caller check whether the step is finished,
6795 etc., before deciding to move it past a breakpoint. */
6796 if (ecs->event_thread->control.step_range_end != 0)
6799 /* Check if the current thread is blocked on an incomplete
6800 step-over, interrupted by a random signal. */
6801 if (ecs->event_thread->control.trap_expected
6802 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6806 fprintf_unfiltered (gdb_stdlog,
6807 "infrun: need to finish step-over of [%s]\n",
6808 target_pid_to_str (ecs->event_thread->ptid));
6814 /* Check if the current thread is blocked by a single-step
6815 breakpoint of another thread. */
6816 if (ecs->hit_singlestep_breakpoint)
6820 fprintf_unfiltered (gdb_stdlog,
6821 "infrun: need to step [%s] over single-step "
6823 target_pid_to_str (ecs->ptid));
6829 /* If this thread needs yet another step-over (e.g., stepping
6830 through a delay slot), do it first before moving on to
6832 if (thread_still_needs_step_over (ecs->event_thread))
6836 fprintf_unfiltered (gdb_stdlog,
6837 "infrun: thread [%s] still needs step-over\n",
6838 target_pid_to_str (ecs->event_thread->ptid));
6844 /* If scheduler locking applies even if not stepping, there's no
6845 need to walk over threads. Above we've checked whether the
6846 current thread is stepping. If some other thread not the
6847 event thread is stepping, then it must be that scheduler
6848 locking is not in effect. */
6849 if (schedlock_applies (ecs->event_thread))
6852 /* Otherwise, we no longer expect a trap in the current thread.
6853 Clear the trap_expected flag before switching back -- this is
6854 what keep_going does as well, if we call it. */
6855 ecs->event_thread->control.trap_expected = 0;
6857 /* Likewise, clear the signal if it should not be passed. */
6858 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6859 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6861 /* Do all pending step-overs before actually proceeding with
6863 if (start_step_over ())
6865 prepare_to_wait (ecs);
6869 /* Look for the stepping/nexting thread. */
6870 stepping_thread = NULL;
6872 ALL_NON_EXITED_THREADS (tp)
6874 /* Ignore threads of processes the caller is not
6877 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
6880 /* When stepping over a breakpoint, we lock all threads
6881 except the one that needs to move past the breakpoint.
6882 If a non-event thread has this set, the "incomplete
6883 step-over" check above should have caught it earlier. */
6884 if (tp->control.trap_expected)
6886 internal_error (__FILE__, __LINE__,
6887 "[%s] has inconsistent state: "
6888 "trap_expected=%d\n",
6889 target_pid_to_str (tp->ptid),
6890 tp->control.trap_expected);
6893 /* Did we find the stepping thread? */
6894 if (tp->control.step_range_end)
6896 /* Yep. There should only one though. */
6897 gdb_assert (stepping_thread == NULL);
6899 /* The event thread is handled at the top, before we
6901 gdb_assert (tp != ecs->event_thread);
6903 /* If some thread other than the event thread is
6904 stepping, then scheduler locking can't be in effect,
6905 otherwise we wouldn't have resumed the current event
6906 thread in the first place. */
6907 gdb_assert (!schedlock_applies (tp));
6909 stepping_thread = tp;
6913 if (stepping_thread != NULL)
6916 fprintf_unfiltered (gdb_stdlog,
6917 "infrun: switching back to stepped thread\n");
6919 if (keep_going_stepped_thread (stepping_thread))
6921 prepare_to_wait (ecs);
6930 /* Set a previously stepped thread back to stepping. Returns true on
6931 success, false if the resume is not possible (e.g., the thread
6935 keep_going_stepped_thread (struct thread_info *tp)
6937 struct frame_info *frame;
6938 struct gdbarch *gdbarch;
6939 struct execution_control_state ecss;
6940 struct execution_control_state *ecs = &ecss;
6942 /* If the stepping thread exited, then don't try to switch back and
6943 resume it, which could fail in several different ways depending
6944 on the target. Instead, just keep going.
6946 We can find a stepping dead thread in the thread list in two
6949 - The target supports thread exit events, and when the target
6950 tries to delete the thread from the thread list, inferior_ptid
6951 pointed at the exiting thread. In such case, calling
6952 delete_thread does not really remove the thread from the list;
6953 instead, the thread is left listed, with 'exited' state.
6955 - The target's debug interface does not support thread exit
6956 events, and so we have no idea whatsoever if the previously
6957 stepping thread is still alive. For that reason, we need to
6958 synchronously query the target now. */
6960 if (is_exited (tp->ptid)
6961 || !target_thread_alive (tp->ptid))
6964 fprintf_unfiltered (gdb_stdlog,
6965 "infrun: not resuming previously "
6966 "stepped thread, it has vanished\n");
6968 delete_thread (tp->ptid);
6973 fprintf_unfiltered (gdb_stdlog,
6974 "infrun: resuming previously stepped thread\n");
6976 reset_ecs (ecs, tp);
6977 switch_to_thread (tp->ptid);
6979 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
6980 frame = get_current_frame ();
6981 gdbarch = get_frame_arch (frame);
6983 /* If the PC of the thread we were trying to single-step has
6984 changed, then that thread has trapped or been signaled, but the
6985 event has not been reported to GDB yet. Re-poll the target
6986 looking for this particular thread's event (i.e. temporarily
6987 enable schedlock) by:
6989 - setting a break at the current PC
6990 - resuming that particular thread, only (by setting trap
6993 This prevents us continuously moving the single-step breakpoint
6994 forward, one instruction at a time, overstepping. */
6996 if (stop_pc != tp->prev_pc)
7001 fprintf_unfiltered (gdb_stdlog,
7002 "infrun: expected thread advanced also (%s -> %s)\n",
7003 paddress (target_gdbarch (), tp->prev_pc),
7004 paddress (target_gdbarch (), stop_pc));
7006 /* Clear the info of the previous step-over, as it's no longer
7007 valid (if the thread was trying to step over a breakpoint, it
7008 has already succeeded). It's what keep_going would do too,
7009 if we called it. Do this before trying to insert the sss
7010 breakpoint, otherwise if we were previously trying to step
7011 over this exact address in another thread, the breakpoint is
7013 clear_step_over_info ();
7014 tp->control.trap_expected = 0;
7016 insert_single_step_breakpoint (get_frame_arch (frame),
7017 get_frame_address_space (frame),
7021 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7022 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7027 fprintf_unfiltered (gdb_stdlog,
7028 "infrun: expected thread still hasn't advanced\n");
7030 keep_going_pass_signal (ecs);
7035 /* Is thread TP in the middle of (software or hardware)
7036 single-stepping? (Note the result of this function must never be
7037 passed directly as target_resume's STEP parameter.) */
7040 currently_stepping (struct thread_info *tp)
7042 return ((tp->control.step_range_end
7043 && tp->control.step_resume_breakpoint == NULL)
7044 || tp->control.trap_expected
7045 || tp->stepped_breakpoint
7046 || bpstat_should_step ());
7049 /* Inferior has stepped into a subroutine call with source code that
7050 we should not step over. Do step to the first line of code in
7054 handle_step_into_function (struct gdbarch *gdbarch,
7055 struct execution_control_state *ecs)
7057 struct compunit_symtab *cust;
7058 struct symtab_and_line stop_func_sal, sr_sal;
7060 fill_in_stop_func (gdbarch, ecs);
7062 cust = find_pc_compunit_symtab (stop_pc);
7063 if (cust != NULL && compunit_language (cust) != language_asm)
7064 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7065 ecs->stop_func_start);
7067 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7068 /* Use the step_resume_break to step until the end of the prologue,
7069 even if that involves jumps (as it seems to on the vax under
7071 /* If the prologue ends in the middle of a source line, continue to
7072 the end of that source line (if it is still within the function).
7073 Otherwise, just go to end of prologue. */
7074 if (stop_func_sal.end
7075 && stop_func_sal.pc != ecs->stop_func_start
7076 && stop_func_sal.end < ecs->stop_func_end)
7077 ecs->stop_func_start = stop_func_sal.end;
7079 /* Architectures which require breakpoint adjustment might not be able
7080 to place a breakpoint at the computed address. If so, the test
7081 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7082 ecs->stop_func_start to an address at which a breakpoint may be
7083 legitimately placed.
7085 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7086 made, GDB will enter an infinite loop when stepping through
7087 optimized code consisting of VLIW instructions which contain
7088 subinstructions corresponding to different source lines. On
7089 FR-V, it's not permitted to place a breakpoint on any but the
7090 first subinstruction of a VLIW instruction. When a breakpoint is
7091 set, GDB will adjust the breakpoint address to the beginning of
7092 the VLIW instruction. Thus, we need to make the corresponding
7093 adjustment here when computing the stop address. */
7095 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7097 ecs->stop_func_start
7098 = gdbarch_adjust_breakpoint_address (gdbarch,
7099 ecs->stop_func_start);
7102 if (ecs->stop_func_start == stop_pc)
7104 /* We are already there: stop now. */
7105 end_stepping_range (ecs);
7110 /* Put the step-breakpoint there and go until there. */
7111 init_sal (&sr_sal); /* initialize to zeroes */
7112 sr_sal.pc = ecs->stop_func_start;
7113 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7114 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7116 /* Do not specify what the fp should be when we stop since on
7117 some machines the prologue is where the new fp value is
7119 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7121 /* And make sure stepping stops right away then. */
7122 ecs->event_thread->control.step_range_end
7123 = ecs->event_thread->control.step_range_start;
7128 /* Inferior has stepped backward into a subroutine call with source
7129 code that we should not step over. Do step to the beginning of the
7130 last line of code in it. */
7133 handle_step_into_function_backward (struct gdbarch *gdbarch,
7134 struct execution_control_state *ecs)
7136 struct compunit_symtab *cust;
7137 struct symtab_and_line stop_func_sal;
7139 fill_in_stop_func (gdbarch, ecs);
7141 cust = find_pc_compunit_symtab (stop_pc);
7142 if (cust != NULL && compunit_language (cust) != language_asm)
7143 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7144 ecs->stop_func_start);
7146 stop_func_sal = find_pc_line (stop_pc, 0);
7148 /* OK, we're just going to keep stepping here. */
7149 if (stop_func_sal.pc == stop_pc)
7151 /* We're there already. Just stop stepping now. */
7152 end_stepping_range (ecs);
7156 /* Else just reset the step range and keep going.
7157 No step-resume breakpoint, they don't work for
7158 epilogues, which can have multiple entry paths. */
7159 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7160 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7166 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7167 This is used to both functions and to skip over code. */
7170 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7171 struct symtab_and_line sr_sal,
7172 struct frame_id sr_id,
7173 enum bptype sr_type)
7175 /* There should never be more than one step-resume or longjmp-resume
7176 breakpoint per thread, so we should never be setting a new
7177 step_resume_breakpoint when one is already active. */
7178 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7179 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7182 fprintf_unfiltered (gdb_stdlog,
7183 "infrun: inserting step-resume breakpoint at %s\n",
7184 paddress (gdbarch, sr_sal.pc));
7186 inferior_thread ()->control.step_resume_breakpoint
7187 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7191 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7192 struct symtab_and_line sr_sal,
7193 struct frame_id sr_id)
7195 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7200 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7201 This is used to skip a potential signal handler.
7203 This is called with the interrupted function's frame. The signal
7204 handler, when it returns, will resume the interrupted function at
7208 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7210 struct symtab_and_line sr_sal;
7211 struct gdbarch *gdbarch;
7213 gdb_assert (return_frame != NULL);
7214 init_sal (&sr_sal); /* initialize to zeros */
7216 gdbarch = get_frame_arch (return_frame);
7217 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7218 sr_sal.section = find_pc_overlay (sr_sal.pc);
7219 sr_sal.pspace = get_frame_program_space (return_frame);
7221 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7222 get_stack_frame_id (return_frame),
7226 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7227 is used to skip a function after stepping into it (for "next" or if
7228 the called function has no debugging information).
7230 The current function has almost always been reached by single
7231 stepping a call or return instruction. NEXT_FRAME belongs to the
7232 current function, and the breakpoint will be set at the caller's
7235 This is a separate function rather than reusing
7236 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7237 get_prev_frame, which may stop prematurely (see the implementation
7238 of frame_unwind_caller_id for an example). */
7241 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7243 struct symtab_and_line sr_sal;
7244 struct gdbarch *gdbarch;
7246 /* We shouldn't have gotten here if we don't know where the call site
7248 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7250 init_sal (&sr_sal); /* initialize to zeros */
7252 gdbarch = frame_unwind_caller_arch (next_frame);
7253 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7254 frame_unwind_caller_pc (next_frame));
7255 sr_sal.section = find_pc_overlay (sr_sal.pc);
7256 sr_sal.pspace = frame_unwind_program_space (next_frame);
7258 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7259 frame_unwind_caller_id (next_frame));
7262 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7263 new breakpoint at the target of a jmp_buf. The handling of
7264 longjmp-resume uses the same mechanisms used for handling
7265 "step-resume" breakpoints. */
7268 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7270 /* There should never be more than one longjmp-resume breakpoint per
7271 thread, so we should never be setting a new
7272 longjmp_resume_breakpoint when one is already active. */
7273 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7276 fprintf_unfiltered (gdb_stdlog,
7277 "infrun: inserting longjmp-resume breakpoint at %s\n",
7278 paddress (gdbarch, pc));
7280 inferior_thread ()->control.exception_resume_breakpoint =
7281 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7284 /* Insert an exception resume breakpoint. TP is the thread throwing
7285 the exception. The block B is the block of the unwinder debug hook
7286 function. FRAME is the frame corresponding to the call to this
7287 function. SYM is the symbol of the function argument holding the
7288 target PC of the exception. */
7291 insert_exception_resume_breakpoint (struct thread_info *tp,
7292 const struct block *b,
7293 struct frame_info *frame,
7298 struct block_symbol vsym;
7299 struct value *value;
7301 struct breakpoint *bp;
7303 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7304 value = read_var_value (vsym.symbol, vsym.block, frame);
7305 /* If the value was optimized out, revert to the old behavior. */
7306 if (! value_optimized_out (value))
7308 handler = value_as_address (value);
7311 fprintf_unfiltered (gdb_stdlog,
7312 "infrun: exception resume at %lx\n",
7313 (unsigned long) handler);
7315 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7316 handler, bp_exception_resume);
7318 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7321 bp->thread = tp->num;
7322 inferior_thread ()->control.exception_resume_breakpoint = bp;
7325 CATCH (e, RETURN_MASK_ERROR)
7327 /* We want to ignore errors here. */
7332 /* A helper for check_exception_resume that sets an
7333 exception-breakpoint based on a SystemTap probe. */
7336 insert_exception_resume_from_probe (struct thread_info *tp,
7337 const struct bound_probe *probe,
7338 struct frame_info *frame)
7340 struct value *arg_value;
7342 struct breakpoint *bp;
7344 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7348 handler = value_as_address (arg_value);
7351 fprintf_unfiltered (gdb_stdlog,
7352 "infrun: exception resume at %s\n",
7353 paddress (get_objfile_arch (probe->objfile),
7356 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7357 handler, bp_exception_resume);
7358 bp->thread = tp->num;
7359 inferior_thread ()->control.exception_resume_breakpoint = bp;
7362 /* This is called when an exception has been intercepted. Check to
7363 see whether the exception's destination is of interest, and if so,
7364 set an exception resume breakpoint there. */
7367 check_exception_resume (struct execution_control_state *ecs,
7368 struct frame_info *frame)
7370 struct bound_probe probe;
7371 struct symbol *func;
7373 /* First see if this exception unwinding breakpoint was set via a
7374 SystemTap probe point. If so, the probe has two arguments: the
7375 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7376 set a breakpoint there. */
7377 probe = find_probe_by_pc (get_frame_pc (frame));
7380 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7384 func = get_frame_function (frame);
7390 const struct block *b;
7391 struct block_iterator iter;
7395 /* The exception breakpoint is a thread-specific breakpoint on
7396 the unwinder's debug hook, declared as:
7398 void _Unwind_DebugHook (void *cfa, void *handler);
7400 The CFA argument indicates the frame to which control is
7401 about to be transferred. HANDLER is the destination PC.
7403 We ignore the CFA and set a temporary breakpoint at HANDLER.
7404 This is not extremely efficient but it avoids issues in gdb
7405 with computing the DWARF CFA, and it also works even in weird
7406 cases such as throwing an exception from inside a signal
7409 b = SYMBOL_BLOCK_VALUE (func);
7410 ALL_BLOCK_SYMBOLS (b, iter, sym)
7412 if (!SYMBOL_IS_ARGUMENT (sym))
7419 insert_exception_resume_breakpoint (ecs->event_thread,
7425 CATCH (e, RETURN_MASK_ERROR)
7432 stop_waiting (struct execution_control_state *ecs)
7435 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7437 clear_step_over_info ();
7439 /* Let callers know we don't want to wait for the inferior anymore. */
7440 ecs->wait_some_more = 0;
7442 /* If all-stop, but the target is always in non-stop mode, stop all
7443 threads now that we're presenting the stop to the user. */
7444 if (!non_stop && target_is_non_stop_p ())
7445 stop_all_threads ();
7448 /* Like keep_going, but passes the signal to the inferior, even if the
7449 signal is set to nopass. */
7452 keep_going_pass_signal (struct execution_control_state *ecs)
7454 /* Make sure normal_stop is called if we get a QUIT handled before
7456 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7458 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7459 gdb_assert (!ecs->event_thread->resumed);
7461 /* Save the pc before execution, to compare with pc after stop. */
7462 ecs->event_thread->prev_pc
7463 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7465 if (ecs->event_thread->control.trap_expected)
7467 struct thread_info *tp = ecs->event_thread;
7470 fprintf_unfiltered (gdb_stdlog,
7471 "infrun: %s has trap_expected set, "
7472 "resuming to collect trap\n",
7473 target_pid_to_str (tp->ptid));
7475 /* We haven't yet gotten our trap, and either: intercepted a
7476 non-signal event (e.g., a fork); or took a signal which we
7477 are supposed to pass through to the inferior. Simply
7479 discard_cleanups (old_cleanups);
7480 resume (ecs->event_thread->suspend.stop_signal);
7482 else if (step_over_info_valid_p ())
7484 /* Another thread is stepping over a breakpoint in-line. If
7485 this thread needs a step-over too, queue the request. In
7486 either case, this resume must be deferred for later. */
7487 struct thread_info *tp = ecs->event_thread;
7489 if (ecs->hit_singlestep_breakpoint
7490 || thread_still_needs_step_over (tp))
7493 fprintf_unfiltered (gdb_stdlog,
7494 "infrun: step-over already in progress: "
7495 "step-over for %s deferred\n",
7496 target_pid_to_str (tp->ptid));
7497 thread_step_over_chain_enqueue (tp);
7502 fprintf_unfiltered (gdb_stdlog,
7503 "infrun: step-over in progress: "
7504 "resume of %s deferred\n",
7505 target_pid_to_str (tp->ptid));
7508 discard_cleanups (old_cleanups);
7512 struct regcache *regcache = get_current_regcache ();
7515 enum step_over_what step_what;
7517 /* Either the trap was not expected, but we are continuing
7518 anyway (if we got a signal, the user asked it be passed to
7521 We got our expected trap, but decided we should resume from
7524 We're going to run this baby now!
7526 Note that insert_breakpoints won't try to re-insert
7527 already inserted breakpoints. Therefore, we don't
7528 care if breakpoints were already inserted, or not. */
7530 /* If we need to step over a breakpoint, and we're not using
7531 displaced stepping to do so, insert all breakpoints
7532 (watchpoints, etc.) but the one we're stepping over, step one
7533 instruction, and then re-insert the breakpoint when that step
7536 step_what = thread_still_needs_step_over (ecs->event_thread);
7538 remove_bp = (ecs->hit_singlestep_breakpoint
7539 || (step_what & STEP_OVER_BREAKPOINT));
7540 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7542 /* We can't use displaced stepping if we need to step past a
7543 watchpoint. The instruction copied to the scratch pad would
7544 still trigger the watchpoint. */
7546 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7548 set_step_over_info (get_regcache_aspace (regcache),
7549 regcache_read_pc (regcache), remove_wps);
7551 else if (remove_wps)
7552 set_step_over_info (NULL, 0, remove_wps);
7554 /* If we now need to do an in-line step-over, we need to stop
7555 all other threads. Note this must be done before
7556 insert_breakpoints below, because that removes the breakpoint
7557 we're about to step over, otherwise other threads could miss
7559 if (step_over_info_valid_p () && target_is_non_stop_p ())
7560 stop_all_threads ();
7562 /* Stop stepping if inserting breakpoints fails. */
7565 insert_breakpoints ();
7567 CATCH (e, RETURN_MASK_ERROR)
7569 exception_print (gdb_stderr, e);
7571 discard_cleanups (old_cleanups);
7576 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7578 discard_cleanups (old_cleanups);
7579 resume (ecs->event_thread->suspend.stop_signal);
7582 prepare_to_wait (ecs);
7585 /* Called when we should continue running the inferior, because the
7586 current event doesn't cause a user visible stop. This does the
7587 resuming part; waiting for the next event is done elsewhere. */
7590 keep_going (struct execution_control_state *ecs)
7592 if (ecs->event_thread->control.trap_expected
7593 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7594 ecs->event_thread->control.trap_expected = 0;
7596 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7597 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7598 keep_going_pass_signal (ecs);
7601 /* This function normally comes after a resume, before
7602 handle_inferior_event exits. It takes care of any last bits of
7603 housekeeping, and sets the all-important wait_some_more flag. */
7606 prepare_to_wait (struct execution_control_state *ecs)
7609 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7611 ecs->wait_some_more = 1;
7613 if (!target_is_async_p ())
7614 mark_infrun_async_event_handler ();
7617 /* We are done with the step range of a step/next/si/ni command.
7618 Called once for each n of a "step n" operation. */
7621 end_stepping_range (struct execution_control_state *ecs)
7623 ecs->event_thread->control.stop_step = 1;
7627 /* Several print_*_reason functions to print why the inferior has stopped.
7628 We always print something when the inferior exits, or receives a signal.
7629 The rest of the cases are dealt with later on in normal_stop and
7630 print_it_typical. Ideally there should be a call to one of these
7631 print_*_reason functions functions from handle_inferior_event each time
7632 stop_waiting is called.
7634 Note that we don't call these directly, instead we delegate that to
7635 the interpreters, through observers. Interpreters then call these
7636 with whatever uiout is right. */
7639 print_end_stepping_range_reason (struct ui_out *uiout)
7641 /* For CLI-like interpreters, print nothing. */
7643 if (ui_out_is_mi_like_p (uiout))
7645 ui_out_field_string (uiout, "reason",
7646 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7651 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7653 annotate_signalled ();
7654 if (ui_out_is_mi_like_p (uiout))
7656 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7657 ui_out_text (uiout, "\nProgram terminated with signal ");
7658 annotate_signal_name ();
7659 ui_out_field_string (uiout, "signal-name",
7660 gdb_signal_to_name (siggnal));
7661 annotate_signal_name_end ();
7662 ui_out_text (uiout, ", ");
7663 annotate_signal_string ();
7664 ui_out_field_string (uiout, "signal-meaning",
7665 gdb_signal_to_string (siggnal));
7666 annotate_signal_string_end ();
7667 ui_out_text (uiout, ".\n");
7668 ui_out_text (uiout, "The program no longer exists.\n");
7672 print_exited_reason (struct ui_out *uiout, int exitstatus)
7674 struct inferior *inf = current_inferior ();
7675 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7677 annotate_exited (exitstatus);
7680 if (ui_out_is_mi_like_p (uiout))
7681 ui_out_field_string (uiout, "reason",
7682 async_reason_lookup (EXEC_ASYNC_EXITED));
7683 ui_out_text (uiout, "[Inferior ");
7684 ui_out_text (uiout, plongest (inf->num));
7685 ui_out_text (uiout, " (");
7686 ui_out_text (uiout, pidstr);
7687 ui_out_text (uiout, ") exited with code ");
7688 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
7689 ui_out_text (uiout, "]\n");
7693 if (ui_out_is_mi_like_p (uiout))
7695 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7696 ui_out_text (uiout, "[Inferior ");
7697 ui_out_text (uiout, plongest (inf->num));
7698 ui_out_text (uiout, " (");
7699 ui_out_text (uiout, pidstr);
7700 ui_out_text (uiout, ") exited normally]\n");
7705 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7709 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
7711 struct thread_info *t = inferior_thread ();
7713 ui_out_text (uiout, "\n[");
7714 ui_out_field_string (uiout, "thread-name",
7715 target_pid_to_str (t->ptid));
7716 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
7717 ui_out_text (uiout, " stopped");
7721 ui_out_text (uiout, "\nProgram received signal ");
7722 annotate_signal_name ();
7723 if (ui_out_is_mi_like_p (uiout))
7725 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7726 ui_out_field_string (uiout, "signal-name",
7727 gdb_signal_to_name (siggnal));
7728 annotate_signal_name_end ();
7729 ui_out_text (uiout, ", ");
7730 annotate_signal_string ();
7731 ui_out_field_string (uiout, "signal-meaning",
7732 gdb_signal_to_string (siggnal));
7733 annotate_signal_string_end ();
7735 ui_out_text (uiout, ".\n");
7739 print_no_history_reason (struct ui_out *uiout)
7741 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
7744 /* Print current location without a level number, if we have changed
7745 functions or hit a breakpoint. Print source line if we have one.
7746 bpstat_print contains the logic deciding in detail what to print,
7747 based on the event(s) that just occurred. */
7750 print_stop_location (struct target_waitstatus *ws)
7753 enum print_what source_flag;
7754 int do_frame_printing = 1;
7755 struct thread_info *tp = inferior_thread ();
7757 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7761 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7762 should) carry around the function and does (or should) use
7763 that when doing a frame comparison. */
7764 if (tp->control.stop_step
7765 && frame_id_eq (tp->control.step_frame_id,
7766 get_frame_id (get_current_frame ()))
7767 && tp->control.step_start_function == find_pc_function (stop_pc))
7769 /* Finished step, just print source line. */
7770 source_flag = SRC_LINE;
7774 /* Print location and source line. */
7775 source_flag = SRC_AND_LOC;
7778 case PRINT_SRC_AND_LOC:
7779 /* Print location and source line. */
7780 source_flag = SRC_AND_LOC;
7782 case PRINT_SRC_ONLY:
7783 source_flag = SRC_LINE;
7786 /* Something bogus. */
7787 source_flag = SRC_LINE;
7788 do_frame_printing = 0;
7791 internal_error (__FILE__, __LINE__, _("Unknown value."));
7794 /* The behavior of this routine with respect to the source
7796 SRC_LINE: Print only source line
7797 LOCATION: Print only location
7798 SRC_AND_LOC: Print location and source line. */
7799 if (do_frame_printing)
7800 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7803 /* Cleanup that restores a previous current uiout. */
7806 restore_current_uiout_cleanup (void *arg)
7808 struct ui_out *saved_uiout = arg;
7810 current_uiout = saved_uiout;
7816 print_stop_event (struct ui_out *uiout)
7818 struct cleanup *old_chain;
7819 struct target_waitstatus last;
7821 struct thread_info *tp;
7823 get_last_target_status (&last_ptid, &last);
7825 old_chain = make_cleanup (restore_current_uiout_cleanup, current_uiout);
7826 current_uiout = uiout;
7828 print_stop_location (&last);
7830 /* Display the auto-display expressions. */
7833 do_cleanups (old_chain);
7835 tp = inferior_thread ();
7836 if (tp->thread_fsm != NULL
7837 && thread_fsm_finished_p (tp->thread_fsm))
7839 struct return_value_info *rv;
7841 rv = thread_fsm_return_value (tp->thread_fsm);
7843 print_return_value (uiout, rv);
7850 maybe_remove_breakpoints (void)
7852 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7854 if (remove_breakpoints ())
7856 target_terminal_ours_for_output ();
7857 printf_filtered (_("Cannot remove breakpoints because "
7858 "program is no longer writable.\nFurther "
7859 "execution is probably impossible.\n"));
7864 /* The execution context that just caused a normal stop. */
7871 /* The event PTID. */
7875 /* If stopp for a thread event, this is the thread that caused the
7877 struct thread_info *thread;
7879 /* The inferior that caused the stop. */
7883 /* Returns a new stop context. If stopped for a thread event, this
7884 takes a strong reference to the thread. */
7886 static struct stop_context *
7887 save_stop_context (void)
7889 struct stop_context *sc = xmalloc (sizeof (struct stop_context));
7891 sc->stop_id = get_stop_id ();
7892 sc->ptid = inferior_ptid;
7893 sc->inf_num = current_inferior ()->num;
7895 if (!ptid_equal (inferior_ptid, null_ptid))
7897 /* Take a strong reference so that the thread can't be deleted
7899 sc->thread = inferior_thread ();
7900 sc->thread->refcount++;
7908 /* Release a stop context previously created with save_stop_context.
7909 Releases the strong reference to the thread as well. */
7912 release_stop_context_cleanup (void *arg)
7914 struct stop_context *sc = arg;
7916 if (sc->thread != NULL)
7917 sc->thread->refcount--;
7921 /* Return true if the current context no longer matches the saved stop
7925 stop_context_changed (struct stop_context *prev)
7927 if (!ptid_equal (prev->ptid, inferior_ptid))
7929 if (prev->inf_num != current_inferior ()->num)
7931 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
7933 if (get_stop_id () != prev->stop_id)
7943 struct target_waitstatus last;
7945 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
7948 get_last_target_status (&last_ptid, &last);
7952 /* If an exception is thrown from this point on, make sure to
7953 propagate GDB's knowledge of the executing state to the
7954 frontend/user running state. A QUIT is an easy exception to see
7955 here, so do this before any filtered output. */
7957 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
7958 else if (last.kind == TARGET_WAITKIND_SIGNALLED
7959 || last.kind == TARGET_WAITKIND_EXITED)
7961 /* On some targets, we may still have live threads in the
7962 inferior when we get a process exit event. E.g., for
7963 "checkpoint", when the current checkpoint/fork exits,
7964 linux-fork.c automatically switches to another fork from
7965 within target_mourn_inferior. */
7966 if (!ptid_equal (inferior_ptid, null_ptid))
7968 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
7969 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
7972 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
7973 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
7975 /* As we're presenting a stop, and potentially removing breakpoints,
7976 update the thread list so we can tell whether there are threads
7977 running on the target. With target remote, for example, we can
7978 only learn about new threads when we explicitly update the thread
7979 list. Do this before notifying the interpreters about signal
7980 stops, end of stepping ranges, etc., so that the "new thread"
7981 output is emitted before e.g., "Program received signal FOO",
7982 instead of after. */
7983 update_thread_list ();
7985 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
7986 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
7988 /* As with the notification of thread events, we want to delay
7989 notifying the user that we've switched thread context until
7990 the inferior actually stops.
7992 There's no point in saying anything if the inferior has exited.
7993 Note that SIGNALLED here means "exited with a signal", not
7994 "received a signal".
7996 Also skip saying anything in non-stop mode. In that mode, as we
7997 don't want GDB to switch threads behind the user's back, to avoid
7998 races where the user is typing a command to apply to thread x,
7999 but GDB switches to thread y before the user finishes entering
8000 the command, fetch_inferior_event installs a cleanup to restore
8001 the current thread back to the thread the user had selected right
8002 after this event is handled, so we're not really switching, only
8003 informing of a stop. */
8005 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8006 && target_has_execution
8007 && last.kind != TARGET_WAITKIND_SIGNALLED
8008 && last.kind != TARGET_WAITKIND_EXITED
8009 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8011 target_terminal_ours_for_output ();
8012 printf_filtered (_("[Switching to %s]\n"),
8013 target_pid_to_str (inferior_ptid));
8014 annotate_thread_changed ();
8015 previous_inferior_ptid = inferior_ptid;
8018 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8020 gdb_assert (sync_execution || !target_can_async_p ());
8022 target_terminal_ours_for_output ();
8023 printf_filtered (_("No unwaited-for children left.\n"));
8026 /* Note: this depends on the update_thread_list call above. */
8027 maybe_remove_breakpoints ();
8029 /* If an auto-display called a function and that got a signal,
8030 delete that auto-display to avoid an infinite recursion. */
8032 if (stopped_by_random_signal)
8033 disable_current_display ();
8035 target_terminal_ours ();
8036 async_enable_stdin ();
8038 /* Let the user/frontend see the threads as stopped. */
8039 do_cleanups (old_chain);
8041 /* Select innermost stack frame - i.e., current frame is frame 0,
8042 and current location is based on that. Handle the case where the
8043 dummy call is returning after being stopped. E.g. the dummy call
8044 previously hit a breakpoint. (If the dummy call returns
8045 normally, we won't reach here.) Do this before the stop hook is
8046 run, so that it doesn't get to see the temporary dummy frame,
8047 which is not where we'll present the stop. */
8048 if (has_stack_frames ())
8050 if (stop_stack_dummy == STOP_STACK_DUMMY)
8052 /* Pop the empty frame that contains the stack dummy. This
8053 also restores inferior state prior to the call (struct
8054 infcall_suspend_state). */
8055 struct frame_info *frame = get_current_frame ();
8057 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8059 /* frame_pop calls reinit_frame_cache as the last thing it
8060 does which means there's now no selected frame. */
8063 select_frame (get_current_frame ());
8065 /* Set the current source location. */
8066 set_current_sal_from_frame (get_current_frame ());
8069 /* Look up the hook_stop and run it (CLI internally handles problem
8070 of stop_command's pre-hook not existing). */
8071 if (stop_command != NULL)
8073 struct stop_context *saved_context = save_stop_context ();
8074 struct cleanup *old_chain
8075 = make_cleanup (release_stop_context_cleanup, saved_context);
8077 catch_errors (hook_stop_stub, stop_command,
8078 "Error while running hook_stop:\n", RETURN_MASK_ALL);
8080 /* If the stop hook resumes the target, then there's no point in
8081 trying to notify about the previous stop; its context is
8082 gone. Likewise if the command switches thread or inferior --
8083 the observers would print a stop for the wrong
8085 if (stop_context_changed (saved_context))
8087 do_cleanups (old_chain);
8090 do_cleanups (old_chain);
8093 /* Notify observers about the stop. This is where the interpreters
8094 print the stop event. */
8095 if (!ptid_equal (inferior_ptid, null_ptid))
8096 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8099 observer_notify_normal_stop (NULL, stop_print_frame);
8101 annotate_stopped ();
8103 if (target_has_execution)
8105 if (last.kind != TARGET_WAITKIND_SIGNALLED
8106 && last.kind != TARGET_WAITKIND_EXITED)
8107 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8108 Delete any breakpoint that is to be deleted at the next stop. */
8109 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8112 /* Try to get rid of automatically added inferiors that are no
8113 longer needed. Keeping those around slows down things linearly.
8114 Note that this never removes the current inferior. */
8121 hook_stop_stub (void *cmd)
8123 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
8128 signal_stop_state (int signo)
8130 return signal_stop[signo];
8134 signal_print_state (int signo)
8136 return signal_print[signo];
8140 signal_pass_state (int signo)
8142 return signal_program[signo];
8146 signal_cache_update (int signo)
8150 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8151 signal_cache_update (signo);
8156 signal_pass[signo] = (signal_stop[signo] == 0
8157 && signal_print[signo] == 0
8158 && signal_program[signo] == 1
8159 && signal_catch[signo] == 0);
8163 signal_stop_update (int signo, int state)
8165 int ret = signal_stop[signo];
8167 signal_stop[signo] = state;
8168 signal_cache_update (signo);
8173 signal_print_update (int signo, int state)
8175 int ret = signal_print[signo];
8177 signal_print[signo] = state;
8178 signal_cache_update (signo);
8183 signal_pass_update (int signo, int state)
8185 int ret = signal_program[signo];
8187 signal_program[signo] = state;
8188 signal_cache_update (signo);
8192 /* Update the global 'signal_catch' from INFO and notify the
8196 signal_catch_update (const unsigned int *info)
8200 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8201 signal_catch[i] = info[i] > 0;
8202 signal_cache_update (-1);
8203 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8207 sig_print_header (void)
8209 printf_filtered (_("Signal Stop\tPrint\tPass "
8210 "to program\tDescription\n"));
8214 sig_print_info (enum gdb_signal oursig)
8216 const char *name = gdb_signal_to_name (oursig);
8217 int name_padding = 13 - strlen (name);
8219 if (name_padding <= 0)
8222 printf_filtered ("%s", name);
8223 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8224 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8225 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8226 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8227 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8230 /* Specify how various signals in the inferior should be handled. */
8233 handle_command (char *args, int from_tty)
8236 int digits, wordlen;
8237 int sigfirst, signum, siglast;
8238 enum gdb_signal oursig;
8241 unsigned char *sigs;
8242 struct cleanup *old_chain;
8246 error_no_arg (_("signal to handle"));
8249 /* Allocate and zero an array of flags for which signals to handle. */
8251 nsigs = (int) GDB_SIGNAL_LAST;
8252 sigs = (unsigned char *) alloca (nsigs);
8253 memset (sigs, 0, nsigs);
8255 /* Break the command line up into args. */
8257 argv = gdb_buildargv (args);
8258 old_chain = make_cleanup_freeargv (argv);
8260 /* Walk through the args, looking for signal oursigs, signal names, and
8261 actions. Signal numbers and signal names may be interspersed with
8262 actions, with the actions being performed for all signals cumulatively
8263 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8265 while (*argv != NULL)
8267 wordlen = strlen (*argv);
8268 for (digits = 0; isdigit ((*argv)[digits]); digits++)
8272 sigfirst = siglast = -1;
8274 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
8276 /* Apply action to all signals except those used by the
8277 debugger. Silently skip those. */
8280 siglast = nsigs - 1;
8282 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
8284 SET_SIGS (nsigs, sigs, signal_stop);
8285 SET_SIGS (nsigs, sigs, signal_print);
8287 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
8289 UNSET_SIGS (nsigs, sigs, signal_program);
8291 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
8293 SET_SIGS (nsigs, sigs, signal_print);
8295 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
8297 SET_SIGS (nsigs, sigs, signal_program);
8299 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
8301 UNSET_SIGS (nsigs, sigs, signal_stop);
8303 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
8305 SET_SIGS (nsigs, sigs, signal_program);
8307 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
8309 UNSET_SIGS (nsigs, sigs, signal_print);
8310 UNSET_SIGS (nsigs, sigs, signal_stop);
8312 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
8314 UNSET_SIGS (nsigs, sigs, signal_program);
8316 else if (digits > 0)
8318 /* It is numeric. The numeric signal refers to our own
8319 internal signal numbering from target.h, not to host/target
8320 signal number. This is a feature; users really should be
8321 using symbolic names anyway, and the common ones like
8322 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8324 sigfirst = siglast = (int)
8325 gdb_signal_from_command (atoi (*argv));
8326 if ((*argv)[digits] == '-')
8329 gdb_signal_from_command (atoi ((*argv) + digits + 1));
8331 if (sigfirst > siglast)
8333 /* Bet he didn't figure we'd think of this case... */
8341 oursig = gdb_signal_from_name (*argv);
8342 if (oursig != GDB_SIGNAL_UNKNOWN)
8344 sigfirst = siglast = (int) oursig;
8348 /* Not a number and not a recognized flag word => complain. */
8349 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
8353 /* If any signal numbers or symbol names were found, set flags for
8354 which signals to apply actions to. */
8356 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8358 switch ((enum gdb_signal) signum)
8360 case GDB_SIGNAL_TRAP:
8361 case GDB_SIGNAL_INT:
8362 if (!allsigs && !sigs[signum])
8364 if (query (_("%s is used by the debugger.\n\
8365 Are you sure you want to change it? "),
8366 gdb_signal_to_name ((enum gdb_signal) signum)))
8372 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8373 gdb_flush (gdb_stdout);
8378 case GDB_SIGNAL_DEFAULT:
8379 case GDB_SIGNAL_UNKNOWN:
8380 /* Make sure that "all" doesn't print these. */
8391 for (signum = 0; signum < nsigs; signum++)
8394 signal_cache_update (-1);
8395 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8396 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8400 /* Show the results. */
8401 sig_print_header ();
8402 for (; signum < nsigs; signum++)
8404 sig_print_info ((enum gdb_signal) signum);
8410 do_cleanups (old_chain);
8413 /* Complete the "handle" command. */
8415 static VEC (char_ptr) *
8416 handle_completer (struct cmd_list_element *ignore,
8417 const char *text, const char *word)
8419 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
8420 static const char * const keywords[] =
8434 vec_signals = signal_completer (ignore, text, word);
8435 vec_keywords = complete_on_enum (keywords, word, word);
8437 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
8438 VEC_free (char_ptr, vec_signals);
8439 VEC_free (char_ptr, vec_keywords);
8444 gdb_signal_from_command (int num)
8446 if (num >= 1 && num <= 15)
8447 return (enum gdb_signal) num;
8448 error (_("Only signals 1-15 are valid as numeric signals.\n\
8449 Use \"info signals\" for a list of symbolic signals."));
8452 /* Print current contents of the tables set by the handle command.
8453 It is possible we should just be printing signals actually used
8454 by the current target (but for things to work right when switching
8455 targets, all signals should be in the signal tables). */
8458 signals_info (char *signum_exp, int from_tty)
8460 enum gdb_signal oursig;
8462 sig_print_header ();
8466 /* First see if this is a symbol name. */
8467 oursig = gdb_signal_from_name (signum_exp);
8468 if (oursig == GDB_SIGNAL_UNKNOWN)
8470 /* No, try numeric. */
8472 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8474 sig_print_info (oursig);
8478 printf_filtered ("\n");
8479 /* These ugly casts brought to you by the native VAX compiler. */
8480 for (oursig = GDB_SIGNAL_FIRST;
8481 (int) oursig < (int) GDB_SIGNAL_LAST;
8482 oursig = (enum gdb_signal) ((int) oursig + 1))
8486 if (oursig != GDB_SIGNAL_UNKNOWN
8487 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8488 sig_print_info (oursig);
8491 printf_filtered (_("\nUse the \"handle\" command "
8492 "to change these tables.\n"));
8495 /* Check if it makes sense to read $_siginfo from the current thread
8496 at this point. If not, throw an error. */
8499 validate_siginfo_access (void)
8501 /* No current inferior, no siginfo. */
8502 if (ptid_equal (inferior_ptid, null_ptid))
8503 error (_("No thread selected."));
8505 /* Don't try to read from a dead thread. */
8506 if (is_exited (inferior_ptid))
8507 error (_("The current thread has terminated"));
8509 /* ... or from a spinning thread. */
8510 if (is_running (inferior_ptid))
8511 error (_("Selected thread is running."));
8514 /* The $_siginfo convenience variable is a bit special. We don't know
8515 for sure the type of the value until we actually have a chance to
8516 fetch the data. The type can change depending on gdbarch, so it is
8517 also dependent on which thread you have selected.
8519 1. making $_siginfo be an internalvar that creates a new value on
8522 2. making the value of $_siginfo be an lval_computed value. */
8524 /* This function implements the lval_computed support for reading a
8528 siginfo_value_read (struct value *v)
8530 LONGEST transferred;
8532 validate_siginfo_access ();
8535 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8537 value_contents_all_raw (v),
8539 TYPE_LENGTH (value_type (v)));
8541 if (transferred != TYPE_LENGTH (value_type (v)))
8542 error (_("Unable to read siginfo"));
8545 /* This function implements the lval_computed support for writing a
8549 siginfo_value_write (struct value *v, struct value *fromval)
8551 LONGEST transferred;
8553 validate_siginfo_access ();
8555 transferred = target_write (¤t_target,
8556 TARGET_OBJECT_SIGNAL_INFO,
8558 value_contents_all_raw (fromval),
8560 TYPE_LENGTH (value_type (fromval)));
8562 if (transferred != TYPE_LENGTH (value_type (fromval)))
8563 error (_("Unable to write siginfo"));
8566 static const struct lval_funcs siginfo_value_funcs =
8572 /* Return a new value with the correct type for the siginfo object of
8573 the current thread using architecture GDBARCH. Return a void value
8574 if there's no object available. */
8576 static struct value *
8577 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8580 if (target_has_stack
8581 && !ptid_equal (inferior_ptid, null_ptid)
8582 && gdbarch_get_siginfo_type_p (gdbarch))
8584 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8586 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8589 return allocate_value (builtin_type (gdbarch)->builtin_void);
8593 /* infcall_suspend_state contains state about the program itself like its
8594 registers and any signal it received when it last stopped.
8595 This state must be restored regardless of how the inferior function call
8596 ends (either successfully, or after it hits a breakpoint or signal)
8597 if the program is to properly continue where it left off. */
8599 struct infcall_suspend_state
8601 struct thread_suspend_state thread_suspend;
8605 struct regcache *registers;
8607 /* Format of SIGINFO_DATA or NULL if it is not present. */
8608 struct gdbarch *siginfo_gdbarch;
8610 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8611 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8612 content would be invalid. */
8613 gdb_byte *siginfo_data;
8616 struct infcall_suspend_state *
8617 save_infcall_suspend_state (void)
8619 struct infcall_suspend_state *inf_state;
8620 struct thread_info *tp = inferior_thread ();
8621 struct regcache *regcache = get_current_regcache ();
8622 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8623 gdb_byte *siginfo_data = NULL;
8625 if (gdbarch_get_siginfo_type_p (gdbarch))
8627 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8628 size_t len = TYPE_LENGTH (type);
8629 struct cleanup *back_to;
8631 siginfo_data = xmalloc (len);
8632 back_to = make_cleanup (xfree, siginfo_data);
8634 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8635 siginfo_data, 0, len) == len)
8636 discard_cleanups (back_to);
8639 /* Errors ignored. */
8640 do_cleanups (back_to);
8641 siginfo_data = NULL;
8645 inf_state = XCNEW (struct infcall_suspend_state);
8649 inf_state->siginfo_gdbarch = gdbarch;
8650 inf_state->siginfo_data = siginfo_data;
8653 inf_state->thread_suspend = tp->suspend;
8655 /* run_inferior_call will not use the signal due to its `proceed' call with
8656 GDB_SIGNAL_0 anyway. */
8657 tp->suspend.stop_signal = GDB_SIGNAL_0;
8659 inf_state->stop_pc = stop_pc;
8661 inf_state->registers = regcache_dup (regcache);
8666 /* Restore inferior session state to INF_STATE. */
8669 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8671 struct thread_info *tp = inferior_thread ();
8672 struct regcache *regcache = get_current_regcache ();
8673 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8675 tp->suspend = inf_state->thread_suspend;
8677 stop_pc = inf_state->stop_pc;
8679 if (inf_state->siginfo_gdbarch == gdbarch)
8681 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8683 /* Errors ignored. */
8684 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8685 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8688 /* The inferior can be gone if the user types "print exit(0)"
8689 (and perhaps other times). */
8690 if (target_has_execution)
8691 /* NB: The register write goes through to the target. */
8692 regcache_cpy (regcache, inf_state->registers);
8694 discard_infcall_suspend_state (inf_state);
8698 do_restore_infcall_suspend_state_cleanup (void *state)
8700 restore_infcall_suspend_state (state);
8704 make_cleanup_restore_infcall_suspend_state
8705 (struct infcall_suspend_state *inf_state)
8707 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8711 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8713 regcache_xfree (inf_state->registers);
8714 xfree (inf_state->siginfo_data);
8719 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8721 return inf_state->registers;
8724 /* infcall_control_state contains state regarding gdb's control of the
8725 inferior itself like stepping control. It also contains session state like
8726 the user's currently selected frame. */
8728 struct infcall_control_state
8730 struct thread_control_state thread_control;
8731 struct inferior_control_state inferior_control;
8734 enum stop_stack_kind stop_stack_dummy;
8735 int stopped_by_random_signal;
8736 int stop_after_trap;
8738 /* ID if the selected frame when the inferior function call was made. */
8739 struct frame_id selected_frame_id;
8742 /* Save all of the information associated with the inferior<==>gdb
8745 struct infcall_control_state *
8746 save_infcall_control_state (void)
8748 struct infcall_control_state *inf_status =
8749 XNEW (struct infcall_control_state);
8750 struct thread_info *tp = inferior_thread ();
8751 struct inferior *inf = current_inferior ();
8753 inf_status->thread_control = tp->control;
8754 inf_status->inferior_control = inf->control;
8756 tp->control.step_resume_breakpoint = NULL;
8757 tp->control.exception_resume_breakpoint = NULL;
8759 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8760 chain. If caller's caller is walking the chain, they'll be happier if we
8761 hand them back the original chain when restore_infcall_control_state is
8763 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8766 inf_status->stop_stack_dummy = stop_stack_dummy;
8767 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8768 inf_status->stop_after_trap = stop_after_trap;
8770 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8776 restore_selected_frame (void *args)
8778 struct frame_id *fid = (struct frame_id *) args;
8779 struct frame_info *frame;
8781 frame = frame_find_by_id (*fid);
8783 /* If inf_status->selected_frame_id is NULL, there was no previously
8787 warning (_("Unable to restore previously selected frame."));
8791 select_frame (frame);
8796 /* Restore inferior session state to INF_STATUS. */
8799 restore_infcall_control_state (struct infcall_control_state *inf_status)
8801 struct thread_info *tp = inferior_thread ();
8802 struct inferior *inf = current_inferior ();
8804 if (tp->control.step_resume_breakpoint)
8805 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8807 if (tp->control.exception_resume_breakpoint)
8808 tp->control.exception_resume_breakpoint->disposition
8809 = disp_del_at_next_stop;
8811 /* Handle the bpstat_copy of the chain. */
8812 bpstat_clear (&tp->control.stop_bpstat);
8814 tp->control = inf_status->thread_control;
8815 inf->control = inf_status->inferior_control;
8818 stop_stack_dummy = inf_status->stop_stack_dummy;
8819 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8820 stop_after_trap = inf_status->stop_after_trap;
8822 if (target_has_stack)
8824 /* The point of catch_errors is that if the stack is clobbered,
8825 walking the stack might encounter a garbage pointer and
8826 error() trying to dereference it. */
8828 (restore_selected_frame, &inf_status->selected_frame_id,
8829 "Unable to restore previously selected frame:\n",
8830 RETURN_MASK_ERROR) == 0)
8831 /* Error in restoring the selected frame. Select the innermost
8833 select_frame (get_current_frame ());
8840 do_restore_infcall_control_state_cleanup (void *sts)
8842 restore_infcall_control_state (sts);
8846 make_cleanup_restore_infcall_control_state
8847 (struct infcall_control_state *inf_status)
8849 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
8853 discard_infcall_control_state (struct infcall_control_state *inf_status)
8855 if (inf_status->thread_control.step_resume_breakpoint)
8856 inf_status->thread_control.step_resume_breakpoint->disposition
8857 = disp_del_at_next_stop;
8859 if (inf_status->thread_control.exception_resume_breakpoint)
8860 inf_status->thread_control.exception_resume_breakpoint->disposition
8861 = disp_del_at_next_stop;
8863 /* See save_infcall_control_state for info on stop_bpstat. */
8864 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8869 /* restore_inferior_ptid() will be used by the cleanup machinery
8870 to restore the inferior_ptid value saved in a call to
8871 save_inferior_ptid(). */
8874 restore_inferior_ptid (void *arg)
8876 ptid_t *saved_ptid_ptr = arg;
8878 inferior_ptid = *saved_ptid_ptr;
8882 /* Save the value of inferior_ptid so that it may be restored by a
8883 later call to do_cleanups(). Returns the struct cleanup pointer
8884 needed for later doing the cleanup. */
8887 save_inferior_ptid (void)
8889 ptid_t *saved_ptid_ptr = XNEW (ptid_t);
8891 *saved_ptid_ptr = inferior_ptid;
8892 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
8898 clear_exit_convenience_vars (void)
8900 clear_internalvar (lookup_internalvar ("_exitsignal"));
8901 clear_internalvar (lookup_internalvar ("_exitcode"));
8905 /* User interface for reverse debugging:
8906 Set exec-direction / show exec-direction commands
8907 (returns error unless target implements to_set_exec_direction method). */
8909 int execution_direction = EXEC_FORWARD;
8910 static const char exec_forward[] = "forward";
8911 static const char exec_reverse[] = "reverse";
8912 static const char *exec_direction = exec_forward;
8913 static const char *const exec_direction_names[] = {
8920 set_exec_direction_func (char *args, int from_tty,
8921 struct cmd_list_element *cmd)
8923 if (target_can_execute_reverse)
8925 if (!strcmp (exec_direction, exec_forward))
8926 execution_direction = EXEC_FORWARD;
8927 else if (!strcmp (exec_direction, exec_reverse))
8928 execution_direction = EXEC_REVERSE;
8932 exec_direction = exec_forward;
8933 error (_("Target does not support this operation."));
8938 show_exec_direction_func (struct ui_file *out, int from_tty,
8939 struct cmd_list_element *cmd, const char *value)
8941 switch (execution_direction) {
8943 fprintf_filtered (out, _("Forward.\n"));
8946 fprintf_filtered (out, _("Reverse.\n"));
8949 internal_error (__FILE__, __LINE__,
8950 _("bogus execution_direction value: %d"),
8951 (int) execution_direction);
8956 show_schedule_multiple (struct ui_file *file, int from_tty,
8957 struct cmd_list_element *c, const char *value)
8959 fprintf_filtered (file, _("Resuming the execution of threads "
8960 "of all processes is %s.\n"), value);
8963 /* Implementation of `siginfo' variable. */
8965 static const struct internalvar_funcs siginfo_funcs =
8972 /* Callback for infrun's target events source. This is marked when a
8973 thread has a pending status to process. */
8976 infrun_async_inferior_event_handler (gdb_client_data data)
8978 inferior_event_handler (INF_REG_EVENT, NULL);
8982 _initialize_infrun (void)
8986 struct cmd_list_element *c;
8988 /* Register extra event sources in the event loop. */
8989 infrun_async_inferior_event_token
8990 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
8992 add_info ("signals", signals_info, _("\
8993 What debugger does when program gets various signals.\n\
8994 Specify a signal as argument to print info on that signal only."));
8995 add_info_alias ("handle", "signals", 0);
8997 c = add_com ("handle", class_run, handle_command, _("\
8998 Specify how to handle signals.\n\
8999 Usage: handle SIGNAL [ACTIONS]\n\
9000 Args are signals and actions to apply to those signals.\n\
9001 If no actions are specified, the current settings for the specified signals\n\
9002 will be displayed instead.\n\
9004 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9005 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9006 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9007 The special arg \"all\" is recognized to mean all signals except those\n\
9008 used by the debugger, typically SIGTRAP and SIGINT.\n\
9010 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9011 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9012 Stop means reenter debugger if this signal happens (implies print).\n\
9013 Print means print a message if this signal happens.\n\
9014 Pass means let program see this signal; otherwise program doesn't know.\n\
9015 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9016 Pass and Stop may be combined.\n\
9018 Multiple signals may be specified. Signal numbers and signal names\n\
9019 may be interspersed with actions, with the actions being performed for\n\
9020 all signals cumulatively specified."));
9021 set_cmd_completer (c, handle_completer);
9024 stop_command = add_cmd ("stop", class_obscure,
9025 not_just_help_class_command, _("\
9026 There is no `stop' command, but you can set a hook on `stop'.\n\
9027 This allows you to set a list of commands to be run each time execution\n\
9028 of the program stops."), &cmdlist);
9030 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9031 Set inferior debugging."), _("\
9032 Show inferior debugging."), _("\
9033 When non-zero, inferior specific debugging is enabled."),
9036 &setdebuglist, &showdebuglist);
9038 add_setshow_boolean_cmd ("displaced", class_maintenance,
9039 &debug_displaced, _("\
9040 Set displaced stepping debugging."), _("\
9041 Show displaced stepping debugging."), _("\
9042 When non-zero, displaced stepping specific debugging is enabled."),
9044 show_debug_displaced,
9045 &setdebuglist, &showdebuglist);
9047 add_setshow_boolean_cmd ("non-stop", no_class,
9049 Set whether gdb controls the inferior in non-stop mode."), _("\
9050 Show whether gdb controls the inferior in non-stop mode."), _("\
9051 When debugging a multi-threaded program and this setting is\n\
9052 off (the default, also called all-stop mode), when one thread stops\n\
9053 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9054 all other threads in the program while you interact with the thread of\n\
9055 interest. When you continue or step a thread, you can allow the other\n\
9056 threads to run, or have them remain stopped, but while you inspect any\n\
9057 thread's state, all threads stop.\n\
9059 In non-stop mode, when one thread stops, other threads can continue\n\
9060 to run freely. You'll be able to step each thread independently,\n\
9061 leave it stopped or free to run as needed."),
9067 numsigs = (int) GDB_SIGNAL_LAST;
9068 signal_stop = XNEWVEC (unsigned char, numsigs);
9069 signal_print = XNEWVEC (unsigned char, numsigs);
9070 signal_program = XNEWVEC (unsigned char, numsigs);
9071 signal_catch = XNEWVEC (unsigned char, numsigs);
9072 signal_pass = XNEWVEC (unsigned char, numsigs);
9073 for (i = 0; i < numsigs; i++)
9076 signal_print[i] = 1;
9077 signal_program[i] = 1;
9078 signal_catch[i] = 0;
9081 /* Signals caused by debugger's own actions should not be given to
9082 the program afterwards.
9084 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9085 explicitly specifies that it should be delivered to the target
9086 program. Typically, that would occur when a user is debugging a
9087 target monitor on a simulator: the target monitor sets a
9088 breakpoint; the simulator encounters this breakpoint and halts
9089 the simulation handing control to GDB; GDB, noting that the stop
9090 address doesn't map to any known breakpoint, returns control back
9091 to the simulator; the simulator then delivers the hardware
9092 equivalent of a GDB_SIGNAL_TRAP to the program being
9094 signal_program[GDB_SIGNAL_TRAP] = 0;
9095 signal_program[GDB_SIGNAL_INT] = 0;
9097 /* Signals that are not errors should not normally enter the debugger. */
9098 signal_stop[GDB_SIGNAL_ALRM] = 0;
9099 signal_print[GDB_SIGNAL_ALRM] = 0;
9100 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9101 signal_print[GDB_SIGNAL_VTALRM] = 0;
9102 signal_stop[GDB_SIGNAL_PROF] = 0;
9103 signal_print[GDB_SIGNAL_PROF] = 0;
9104 signal_stop[GDB_SIGNAL_CHLD] = 0;
9105 signal_print[GDB_SIGNAL_CHLD] = 0;
9106 signal_stop[GDB_SIGNAL_IO] = 0;
9107 signal_print[GDB_SIGNAL_IO] = 0;
9108 signal_stop[GDB_SIGNAL_POLL] = 0;
9109 signal_print[GDB_SIGNAL_POLL] = 0;
9110 signal_stop[GDB_SIGNAL_URG] = 0;
9111 signal_print[GDB_SIGNAL_URG] = 0;
9112 signal_stop[GDB_SIGNAL_WINCH] = 0;
9113 signal_print[GDB_SIGNAL_WINCH] = 0;
9114 signal_stop[GDB_SIGNAL_PRIO] = 0;
9115 signal_print[GDB_SIGNAL_PRIO] = 0;
9117 /* These signals are used internally by user-level thread
9118 implementations. (See signal(5) on Solaris.) Like the above
9119 signals, a healthy program receives and handles them as part of
9120 its normal operation. */
9121 signal_stop[GDB_SIGNAL_LWP] = 0;
9122 signal_print[GDB_SIGNAL_LWP] = 0;
9123 signal_stop[GDB_SIGNAL_WAITING] = 0;
9124 signal_print[GDB_SIGNAL_WAITING] = 0;
9125 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9126 signal_print[GDB_SIGNAL_CANCEL] = 0;
9128 /* Update cached state. */
9129 signal_cache_update (-1);
9131 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9132 &stop_on_solib_events, _("\
9133 Set stopping for shared library events."), _("\
9134 Show stopping for shared library events."), _("\
9135 If nonzero, gdb will give control to the user when the dynamic linker\n\
9136 notifies gdb of shared library events. The most common event of interest\n\
9137 to the user would be loading/unloading of a new library."),
9138 set_stop_on_solib_events,
9139 show_stop_on_solib_events,
9140 &setlist, &showlist);
9142 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9143 follow_fork_mode_kind_names,
9144 &follow_fork_mode_string, _("\
9145 Set debugger response to a program call of fork or vfork."), _("\
9146 Show debugger response to a program call of fork or vfork."), _("\
9147 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9148 parent - the original process is debugged after a fork\n\
9149 child - the new process is debugged after a fork\n\
9150 The unfollowed process will continue to run.\n\
9151 By default, the debugger will follow the parent process."),
9153 show_follow_fork_mode_string,
9154 &setlist, &showlist);
9156 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9157 follow_exec_mode_names,
9158 &follow_exec_mode_string, _("\
9159 Set debugger response to a program call of exec."), _("\
9160 Show debugger response to a program call of exec."), _("\
9161 An exec call replaces the program image of a process.\n\
9163 follow-exec-mode can be:\n\
9165 new - the debugger creates a new inferior and rebinds the process\n\
9166 to this new inferior. The program the process was running before\n\
9167 the exec call can be restarted afterwards by restarting the original\n\
9170 same - the debugger keeps the process bound to the same inferior.\n\
9171 The new executable image replaces the previous executable loaded in\n\
9172 the inferior. Restarting the inferior after the exec call restarts\n\
9173 the executable the process was running after the exec call.\n\
9175 By default, the debugger will use the same inferior."),
9177 show_follow_exec_mode_string,
9178 &setlist, &showlist);
9180 add_setshow_enum_cmd ("scheduler-locking", class_run,
9181 scheduler_enums, &scheduler_mode, _("\
9182 Set mode for locking scheduler during execution."), _("\
9183 Show mode for locking scheduler during execution."), _("\
9184 off == no locking (threads may preempt at any time)\n\
9185 on == full locking (no thread except the current thread may run)\n\
9186 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9187 In this mode, other threads may run during other commands."),
9188 set_schedlock_func, /* traps on target vector */
9189 show_scheduler_mode,
9190 &setlist, &showlist);
9192 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9193 Set mode for resuming threads of all processes."), _("\
9194 Show mode for resuming threads of all processes."), _("\
9195 When on, execution commands (such as 'continue' or 'next') resume all\n\
9196 threads of all processes. When off (which is the default), execution\n\
9197 commands only resume the threads of the current process. The set of\n\
9198 threads that are resumed is further refined by the scheduler-locking\n\
9199 mode (see help set scheduler-locking)."),
9201 show_schedule_multiple,
9202 &setlist, &showlist);
9204 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9205 Set mode of the step operation."), _("\
9206 Show mode of the step operation."), _("\
9207 When set, doing a step over a function without debug line information\n\
9208 will stop at the first instruction of that function. Otherwise, the\n\
9209 function is skipped and the step command stops at a different source line."),
9211 show_step_stop_if_no_debug,
9212 &setlist, &showlist);
9214 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9215 &can_use_displaced_stepping, _("\
9216 Set debugger's willingness to use displaced stepping."), _("\
9217 Show debugger's willingness to use displaced stepping."), _("\
9218 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9219 supported by the target architecture. If off, gdb will not use displaced\n\
9220 stepping to step over breakpoints, even if such is supported by the target\n\
9221 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9222 if the target architecture supports it and non-stop mode is active, but will not\n\
9223 use it in all-stop mode (see help set non-stop)."),
9225 show_can_use_displaced_stepping,
9226 &setlist, &showlist);
9228 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9229 &exec_direction, _("Set direction of execution.\n\
9230 Options are 'forward' or 'reverse'."),
9231 _("Show direction of execution (forward/reverse)."),
9232 _("Tells gdb whether to execute forward or backward."),
9233 set_exec_direction_func, show_exec_direction_func,
9234 &setlist, &showlist);
9236 /* Set/show detach-on-fork: user-settable mode. */
9238 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9239 Set whether gdb will detach the child of a fork."), _("\
9240 Show whether gdb will detach the child of a fork."), _("\
9241 Tells gdb whether to detach the child of a fork."),
9242 NULL, NULL, &setlist, &showlist);
9244 /* Set/show disable address space randomization mode. */
9246 add_setshow_boolean_cmd ("disable-randomization", class_support,
9247 &disable_randomization, _("\
9248 Set disabling of debuggee's virtual address space randomization."), _("\
9249 Show disabling of debuggee's virtual address space randomization."), _("\
9250 When this mode is on (which is the default), randomization of the virtual\n\
9251 address space is disabled. Standalone programs run with the randomization\n\
9252 enabled by default on some platforms."),
9253 &set_disable_randomization,
9254 &show_disable_randomization,
9255 &setlist, &showlist);
9257 /* ptid initializations */
9258 inferior_ptid = null_ptid;
9259 target_last_wait_ptid = minus_one_ptid;
9261 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9262 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9263 observer_attach_thread_exit (infrun_thread_thread_exit);
9264 observer_attach_inferior_exit (infrun_inferior_exit);
9266 /* Explicitly create without lookup, since that tries to create a
9267 value with a void typed value, and when we get here, gdbarch
9268 isn't initialized yet. At this point, we're quite sure there
9269 isn't another convenience variable of the same name. */
9270 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9272 add_setshow_boolean_cmd ("observer", no_class,
9273 &observer_mode_1, _("\
9274 Set whether gdb controls the inferior in observer mode."), _("\
9275 Show whether gdb controls the inferior in observer mode."), _("\
9276 In observer mode, GDB can get data from the inferior, but not\n\
9277 affect its execution. Registers and memory may not be changed,\n\
9278 breakpoints may not be set, and the program cannot be interrupted\n\