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 schedlock_replay[] = "replay";
2170 static const char *const scheduler_enums[] = {
2177 static const char *scheduler_mode = schedlock_replay;
2179 show_scheduler_mode (struct ui_file *file, int from_tty,
2180 struct cmd_list_element *c, const char *value)
2182 fprintf_filtered (file,
2183 _("Mode for locking scheduler "
2184 "during execution is \"%s\".\n"),
2189 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2191 if (!target_can_lock_scheduler)
2193 scheduler_mode = schedlock_off;
2194 error (_("Target '%s' cannot support this command."), target_shortname);
2198 /* True if execution commands resume all threads of all processes by
2199 default; otherwise, resume only threads of the current inferior
2201 int sched_multi = 0;
2203 /* Try to setup for software single stepping over the specified location.
2204 Return 1 if target_resume() should use hardware single step.
2206 GDBARCH the current gdbarch.
2207 PC the location to step over. */
2210 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2214 if (execution_direction == EXEC_FORWARD
2215 && gdbarch_software_single_step_p (gdbarch)
2216 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
2226 user_visible_resume_ptid (int step)
2232 /* With non-stop mode on, threads are always handled
2234 resume_ptid = inferior_ptid;
2236 else if ((scheduler_mode == schedlock_on)
2237 || (scheduler_mode == schedlock_step && step))
2239 /* User-settable 'scheduler' mode requires solo thread
2241 resume_ptid = inferior_ptid;
2243 else if ((scheduler_mode == schedlock_replay)
2244 && target_record_will_replay (minus_one_ptid, execution_direction))
2246 /* User-settable 'scheduler' mode requires solo thread resume in replay
2248 resume_ptid = inferior_ptid;
2250 else if (!sched_multi && target_supports_multi_process ())
2252 /* Resume all threads of the current process (and none of other
2254 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2258 /* Resume all threads of all processes. */
2259 resume_ptid = RESUME_ALL;
2265 /* Return a ptid representing the set of threads that we will resume,
2266 in the perspective of the target, assuming run control handling
2267 does not require leaving some threads stopped (e.g., stepping past
2268 breakpoint). USER_STEP indicates whether we're about to start the
2269 target for a stepping command. */
2272 internal_resume_ptid (int user_step)
2274 /* In non-stop, we always control threads individually. Note that
2275 the target may always work in non-stop mode even with "set
2276 non-stop off", in which case user_visible_resume_ptid could
2277 return a wildcard ptid. */
2278 if (target_is_non_stop_p ())
2279 return inferior_ptid;
2281 return user_visible_resume_ptid (user_step);
2284 /* Wrapper for target_resume, that handles infrun-specific
2288 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2290 struct thread_info *tp = inferior_thread ();
2292 /* Install inferior's terminal modes. */
2293 target_terminal_inferior ();
2295 /* Avoid confusing the next resume, if the next stop/resume
2296 happens to apply to another thread. */
2297 tp->suspend.stop_signal = GDB_SIGNAL_0;
2299 /* Advise target which signals may be handled silently.
2301 If we have removed breakpoints because we are stepping over one
2302 in-line (in any thread), we need to receive all signals to avoid
2303 accidentally skipping a breakpoint during execution of a signal
2306 Likewise if we're displaced stepping, otherwise a trap for a
2307 breakpoint in a signal handler might be confused with the
2308 displaced step finishing. We don't make the displaced_step_fixup
2309 step distinguish the cases instead, because:
2311 - a backtrace while stopped in the signal handler would show the
2312 scratch pad as frame older than the signal handler, instead of
2313 the real mainline code.
2315 - when the thread is later resumed, the signal handler would
2316 return to the scratch pad area, which would no longer be
2318 if (step_over_info_valid_p ()
2319 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2320 target_pass_signals (0, NULL);
2322 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2324 target_resume (resume_ptid, step, sig);
2327 /* Resume the inferior, but allow a QUIT. This is useful if the user
2328 wants to interrupt some lengthy single-stepping operation
2329 (for child processes, the SIGINT goes to the inferior, and so
2330 we get a SIGINT random_signal, but for remote debugging and perhaps
2331 other targets, that's not true).
2333 SIG is the signal to give the inferior (zero for none). */
2335 resume (enum gdb_signal sig)
2337 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2338 struct regcache *regcache = get_current_regcache ();
2339 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2340 struct thread_info *tp = inferior_thread ();
2341 CORE_ADDR pc = regcache_read_pc (regcache);
2342 struct address_space *aspace = get_regcache_aspace (regcache);
2344 /* This represents the user's step vs continue request. When
2345 deciding whether "set scheduler-locking step" applies, it's the
2346 user's intention that counts. */
2347 const int user_step = tp->control.stepping_command;
2348 /* This represents what we'll actually request the target to do.
2349 This can decay from a step to a continue, if e.g., we need to
2350 implement single-stepping with breakpoints (software
2354 gdb_assert (!thread_is_in_step_over_chain (tp));
2358 if (tp->suspend.waitstatus_pending_p)
2364 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2365 fprintf_unfiltered (gdb_stdlog,
2366 "infrun: resume: thread %s has pending wait status %s "
2367 "(currently_stepping=%d).\n",
2368 target_pid_to_str (tp->ptid), statstr,
2369 currently_stepping (tp));
2375 /* FIXME: What should we do if we are supposed to resume this
2376 thread with a signal? Maybe we should maintain a queue of
2377 pending signals to deliver. */
2378 if (sig != GDB_SIGNAL_0)
2380 warning (_("Couldn't deliver signal %s to %s."),
2381 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2384 tp->suspend.stop_signal = GDB_SIGNAL_0;
2385 discard_cleanups (old_cleanups);
2387 if (target_can_async_p ())
2392 tp->stepped_breakpoint = 0;
2394 /* Depends on stepped_breakpoint. */
2395 step = currently_stepping (tp);
2397 if (current_inferior ()->waiting_for_vfork_done)
2399 /* Don't try to single-step a vfork parent that is waiting for
2400 the child to get out of the shared memory region (by exec'ing
2401 or exiting). This is particularly important on software
2402 single-step archs, as the child process would trip on the
2403 software single step breakpoint inserted for the parent
2404 process. Since the parent will not actually execute any
2405 instruction until the child is out of the shared region (such
2406 are vfork's semantics), it is safe to simply continue it.
2407 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2408 the parent, and tell it to `keep_going', which automatically
2409 re-sets it stepping. */
2411 fprintf_unfiltered (gdb_stdlog,
2412 "infrun: resume : clear step\n");
2417 fprintf_unfiltered (gdb_stdlog,
2418 "infrun: resume (step=%d, signal=%s), "
2419 "trap_expected=%d, current thread [%s] at %s\n",
2420 step, gdb_signal_to_symbol_string (sig),
2421 tp->control.trap_expected,
2422 target_pid_to_str (inferior_ptid),
2423 paddress (gdbarch, pc));
2425 /* Normally, by the time we reach `resume', the breakpoints are either
2426 removed or inserted, as appropriate. The exception is if we're sitting
2427 at a permanent breakpoint; we need to step over it, but permanent
2428 breakpoints can't be removed. So we have to test for it here. */
2429 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2431 if (sig != GDB_SIGNAL_0)
2433 /* We have a signal to pass to the inferior. The resume
2434 may, or may not take us to the signal handler. If this
2435 is a step, we'll need to stop in the signal handler, if
2436 there's one, (if the target supports stepping into
2437 handlers), or in the next mainline instruction, if
2438 there's no handler. If this is a continue, we need to be
2439 sure to run the handler with all breakpoints inserted.
2440 In all cases, set a breakpoint at the current address
2441 (where the handler returns to), and once that breakpoint
2442 is hit, resume skipping the permanent breakpoint. If
2443 that breakpoint isn't hit, then we've stepped into the
2444 signal handler (or hit some other event). We'll delete
2445 the step-resume breakpoint then. */
2448 fprintf_unfiltered (gdb_stdlog,
2449 "infrun: resume: skipping permanent breakpoint, "
2450 "deliver signal first\n");
2452 clear_step_over_info ();
2453 tp->control.trap_expected = 0;
2455 if (tp->control.step_resume_breakpoint == NULL)
2457 /* Set a "high-priority" step-resume, as we don't want
2458 user breakpoints at PC to trigger (again) when this
2460 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2461 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2463 tp->step_after_step_resume_breakpoint = step;
2466 insert_breakpoints ();
2470 /* There's no signal to pass, we can go ahead and skip the
2471 permanent breakpoint manually. */
2473 fprintf_unfiltered (gdb_stdlog,
2474 "infrun: resume: skipping permanent breakpoint\n");
2475 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2476 /* Update pc to reflect the new address from which we will
2477 execute instructions. */
2478 pc = regcache_read_pc (regcache);
2482 /* We've already advanced the PC, so the stepping part
2483 is done. Now we need to arrange for a trap to be
2484 reported to handle_inferior_event. Set a breakpoint
2485 at the current PC, and run to it. Don't update
2486 prev_pc, because if we end in
2487 switch_back_to_stepped_thread, we want the "expected
2488 thread advanced also" branch to be taken. IOW, we
2489 don't want this thread to step further from PC
2491 gdb_assert (!step_over_info_valid_p ());
2492 insert_single_step_breakpoint (gdbarch, aspace, pc);
2493 insert_breakpoints ();
2495 resume_ptid = internal_resume_ptid (user_step);
2496 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2497 discard_cleanups (old_cleanups);
2504 /* If we have a breakpoint to step over, make sure to do a single
2505 step only. Same if we have software watchpoints. */
2506 if (tp->control.trap_expected || bpstat_should_step ())
2507 tp->control.may_range_step = 0;
2509 /* If enabled, step over breakpoints by executing a copy of the
2510 instruction at a different address.
2512 We can't use displaced stepping when we have a signal to deliver;
2513 the comments for displaced_step_prepare explain why. The
2514 comments in the handle_inferior event for dealing with 'random
2515 signals' explain what we do instead.
2517 We can't use displaced stepping when we are waiting for vfork_done
2518 event, displaced stepping breaks the vfork child similarly as single
2519 step software breakpoint. */
2520 if (tp->control.trap_expected
2521 && use_displaced_stepping (tp)
2522 && !step_over_info_valid_p ()
2523 && sig == GDB_SIGNAL_0
2524 && !current_inferior ()->waiting_for_vfork_done)
2526 int prepared = displaced_step_prepare (inferior_ptid);
2531 fprintf_unfiltered (gdb_stdlog,
2532 "Got placed in step-over queue\n");
2534 tp->control.trap_expected = 0;
2535 discard_cleanups (old_cleanups);
2538 else if (prepared < 0)
2540 /* Fallback to stepping over the breakpoint in-line. */
2542 if (target_is_non_stop_p ())
2543 stop_all_threads ();
2545 set_step_over_info (get_regcache_aspace (regcache),
2546 regcache_read_pc (regcache), 0);
2548 step = maybe_software_singlestep (gdbarch, pc);
2550 insert_breakpoints ();
2552 else if (prepared > 0)
2554 struct displaced_step_inferior_state *displaced;
2556 /* Update pc to reflect the new address from which we will
2557 execute instructions due to displaced stepping. */
2558 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2560 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2561 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2562 displaced->step_closure);
2566 /* Do we need to do it the hard way, w/temp breakpoints? */
2568 step = maybe_software_singlestep (gdbarch, pc);
2570 /* Currently, our software single-step implementation leads to different
2571 results than hardware single-stepping in one situation: when stepping
2572 into delivering a signal which has an associated signal handler,
2573 hardware single-step will stop at the first instruction of the handler,
2574 while software single-step will simply skip execution of the handler.
2576 For now, this difference in behavior is accepted since there is no
2577 easy way to actually implement single-stepping into a signal handler
2578 without kernel support.
2580 However, there is one scenario where this difference leads to follow-on
2581 problems: if we're stepping off a breakpoint by removing all breakpoints
2582 and then single-stepping. In this case, the software single-step
2583 behavior means that even if there is a *breakpoint* in the signal
2584 handler, GDB still would not stop.
2586 Fortunately, we can at least fix this particular issue. We detect
2587 here the case where we are about to deliver a signal while software
2588 single-stepping with breakpoints removed. In this situation, we
2589 revert the decisions to remove all breakpoints and insert single-
2590 step breakpoints, and instead we install a step-resume breakpoint
2591 at the current address, deliver the signal without stepping, and
2592 once we arrive back at the step-resume breakpoint, actually step
2593 over the breakpoint we originally wanted to step over. */
2594 if (thread_has_single_step_breakpoints_set (tp)
2595 && sig != GDB_SIGNAL_0
2596 && step_over_info_valid_p ())
2598 /* If we have nested signals or a pending signal is delivered
2599 immediately after a handler returns, might might already have
2600 a step-resume breakpoint set on the earlier handler. We cannot
2601 set another step-resume breakpoint; just continue on until the
2602 original breakpoint is hit. */
2603 if (tp->control.step_resume_breakpoint == NULL)
2605 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2606 tp->step_after_step_resume_breakpoint = 1;
2609 delete_single_step_breakpoints (tp);
2611 clear_step_over_info ();
2612 tp->control.trap_expected = 0;
2614 insert_breakpoints ();
2617 /* If STEP is set, it's a request to use hardware stepping
2618 facilities. But in that case, we should never
2619 use singlestep breakpoint. */
2620 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2622 /* Decide the set of threads to ask the target to resume. */
2623 if ((step || thread_has_single_step_breakpoints_set (tp))
2624 && tp->control.trap_expected)
2626 /* We're allowing a thread to run past a breakpoint it has
2627 hit, by single-stepping the thread with the breakpoint
2628 removed. In which case, we need to single-step only this
2629 thread, and keep others stopped, as they can miss this
2630 breakpoint if allowed to run. */
2631 resume_ptid = inferior_ptid;
2634 resume_ptid = internal_resume_ptid (user_step);
2636 if (execution_direction != EXEC_REVERSE
2637 && step && breakpoint_inserted_here_p (aspace, pc))
2639 /* There are two cases where we currently need to step a
2640 breakpoint instruction when we have a signal to deliver:
2642 - See handle_signal_stop where we handle random signals that
2643 could take out us out of the stepping range. Normally, in
2644 that case we end up continuing (instead of stepping) over the
2645 signal handler with a breakpoint at PC, but there are cases
2646 where we should _always_ single-step, even if we have a
2647 step-resume breakpoint, like when a software watchpoint is
2648 set. Assuming single-stepping and delivering a signal at the
2649 same time would takes us to the signal handler, then we could
2650 have removed the breakpoint at PC to step over it. However,
2651 some hardware step targets (like e.g., Mac OS) can't step
2652 into signal handlers, and for those, we need to leave the
2653 breakpoint at PC inserted, as otherwise if the handler
2654 recurses and executes PC again, it'll miss the breakpoint.
2655 So we leave the breakpoint inserted anyway, but we need to
2656 record that we tried to step a breakpoint instruction, so
2657 that adjust_pc_after_break doesn't end up confused.
2659 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2660 in one thread after another thread that was stepping had been
2661 momentarily paused for a step-over. When we re-resume the
2662 stepping thread, it may be resumed from that address with a
2663 breakpoint that hasn't trapped yet. Seen with
2664 gdb.threads/non-stop-fair-events.exp, on targets that don't
2665 do displaced stepping. */
2668 fprintf_unfiltered (gdb_stdlog,
2669 "infrun: resume: [%s] stepped breakpoint\n",
2670 target_pid_to_str (tp->ptid));
2672 tp->stepped_breakpoint = 1;
2674 /* Most targets can step a breakpoint instruction, thus
2675 executing it normally. But if this one cannot, just
2676 continue and we will hit it anyway. */
2677 if (gdbarch_cannot_step_breakpoint (gdbarch))
2682 && tp->control.trap_expected
2683 && use_displaced_stepping (tp)
2684 && !step_over_info_valid_p ())
2686 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2687 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2688 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2691 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2692 paddress (resume_gdbarch, actual_pc));
2693 read_memory (actual_pc, buf, sizeof (buf));
2694 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2697 if (tp->control.may_range_step)
2699 /* If we're resuming a thread with the PC out of the step
2700 range, then we're doing some nested/finer run control
2701 operation, like stepping the thread out of the dynamic
2702 linker or the displaced stepping scratch pad. We
2703 shouldn't have allowed a range step then. */
2704 gdb_assert (pc_in_thread_step_range (pc, tp));
2707 do_target_resume (resume_ptid, step, sig);
2709 discard_cleanups (old_cleanups);
2716 /* Counter that tracks number of user visible stops. This can be used
2717 to tell whether a command has proceeded the inferior past the
2718 current location. This allows e.g., inferior function calls in
2719 breakpoint commands to not interrupt the command list. When the
2720 call finishes successfully, the inferior is standing at the same
2721 breakpoint as if nothing happened (and so we don't call
2723 static ULONGEST current_stop_id;
2730 return current_stop_id;
2733 /* Called when we report a user visible stop. */
2741 /* Clear out all variables saying what to do when inferior is continued.
2742 First do this, then set the ones you want, then call `proceed'. */
2745 clear_proceed_status_thread (struct thread_info *tp)
2748 fprintf_unfiltered (gdb_stdlog,
2749 "infrun: clear_proceed_status_thread (%s)\n",
2750 target_pid_to_str (tp->ptid));
2752 /* If we're starting a new sequence, then the previous finished
2753 single-step is no longer relevant. */
2754 if (tp->suspend.waitstatus_pending_p)
2756 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2759 fprintf_unfiltered (gdb_stdlog,
2760 "infrun: clear_proceed_status: pending "
2761 "event of %s was a finished step. "
2763 target_pid_to_str (tp->ptid));
2765 tp->suspend.waitstatus_pending_p = 0;
2766 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2768 else if (debug_infrun)
2772 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2773 fprintf_unfiltered (gdb_stdlog,
2774 "infrun: clear_proceed_status_thread: thread %s "
2775 "has pending wait status %s "
2776 "(currently_stepping=%d).\n",
2777 target_pid_to_str (tp->ptid), statstr,
2778 currently_stepping (tp));
2783 /* If this signal should not be seen by program, give it zero.
2784 Used for debugging signals. */
2785 if (!signal_pass_state (tp->suspend.stop_signal))
2786 tp->suspend.stop_signal = GDB_SIGNAL_0;
2788 thread_fsm_delete (tp->thread_fsm);
2789 tp->thread_fsm = NULL;
2791 tp->control.trap_expected = 0;
2792 tp->control.step_range_start = 0;
2793 tp->control.step_range_end = 0;
2794 tp->control.may_range_step = 0;
2795 tp->control.step_frame_id = null_frame_id;
2796 tp->control.step_stack_frame_id = null_frame_id;
2797 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2798 tp->control.step_start_function = NULL;
2799 tp->stop_requested = 0;
2801 tp->control.stop_step = 0;
2803 tp->control.proceed_to_finish = 0;
2805 tp->control.command_interp = NULL;
2806 tp->control.stepping_command = 0;
2808 /* Discard any remaining commands or status from previous stop. */
2809 bpstat_clear (&tp->control.stop_bpstat);
2813 clear_proceed_status (int step)
2815 /* With scheduler-locking replay, stop replaying other threads if we're
2816 not replaying the user-visible resume ptid.
2818 This is a convenience feature to not require the user to explicitly
2819 stop replaying the other threads. We're assuming that the user's
2820 intent is to resume tracing the recorded process. */
2821 if (!non_stop && scheduler_mode == schedlock_replay
2822 && target_record_is_replaying (minus_one_ptid)
2823 && !target_record_will_replay (user_visible_resume_ptid (step),
2824 execution_direction))
2825 target_record_stop_replaying ();
2829 struct thread_info *tp;
2832 resume_ptid = user_visible_resume_ptid (step);
2834 /* In all-stop mode, delete the per-thread status of all threads
2835 we're about to resume, implicitly and explicitly. */
2836 ALL_NON_EXITED_THREADS (tp)
2838 if (!ptid_match (tp->ptid, resume_ptid))
2840 clear_proceed_status_thread (tp);
2844 if (!ptid_equal (inferior_ptid, null_ptid))
2846 struct inferior *inferior;
2850 /* If in non-stop mode, only delete the per-thread status of
2851 the current thread. */
2852 clear_proceed_status_thread (inferior_thread ());
2855 inferior = current_inferior ();
2856 inferior->control.stop_soon = NO_STOP_QUIETLY;
2859 stop_after_trap = 0;
2861 observer_notify_about_to_proceed ();
2864 /* Returns true if TP is still stopped at a breakpoint that needs
2865 stepping-over in order to make progress. If the breakpoint is gone
2866 meanwhile, we can skip the whole step-over dance. */
2869 thread_still_needs_step_over_bp (struct thread_info *tp)
2871 if (tp->stepping_over_breakpoint)
2873 struct regcache *regcache = get_thread_regcache (tp->ptid);
2875 if (breakpoint_here_p (get_regcache_aspace (regcache),
2876 regcache_read_pc (regcache))
2877 == ordinary_breakpoint_here)
2880 tp->stepping_over_breakpoint = 0;
2886 /* Check whether thread TP still needs to start a step-over in order
2887 to make progress when resumed. Returns an bitwise or of enum
2888 step_over_what bits, indicating what needs to be stepped over. */
2891 thread_still_needs_step_over (struct thread_info *tp)
2893 struct inferior *inf = find_inferior_ptid (tp->ptid);
2896 if (thread_still_needs_step_over_bp (tp))
2897 what |= STEP_OVER_BREAKPOINT;
2899 if (tp->stepping_over_watchpoint
2900 && !target_have_steppable_watchpoint)
2901 what |= STEP_OVER_WATCHPOINT;
2906 /* Returns true if scheduler locking applies. STEP indicates whether
2907 we're about to do a step/next-like command to a thread. */
2910 schedlock_applies (struct thread_info *tp)
2912 return (scheduler_mode == schedlock_on
2913 || (scheduler_mode == schedlock_step
2914 && tp->control.stepping_command)
2915 || (scheduler_mode == schedlock_replay
2916 && target_record_will_replay (minus_one_ptid,
2917 execution_direction)));
2920 /* Basic routine for continuing the program in various fashions.
2922 ADDR is the address to resume at, or -1 for resume where stopped.
2923 SIGGNAL is the signal to give it, or 0 for none,
2924 or -1 for act according to how it stopped.
2925 STEP is nonzero if should trap after one instruction.
2926 -1 means return after that and print nothing.
2927 You should probably set various step_... variables
2928 before calling here, if you are stepping.
2930 You should call clear_proceed_status before calling proceed. */
2933 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2935 struct regcache *regcache;
2936 struct gdbarch *gdbarch;
2937 struct thread_info *tp;
2939 struct address_space *aspace;
2941 struct execution_control_state ecss;
2942 struct execution_control_state *ecs = &ecss;
2943 struct cleanup *old_chain;
2946 /* If we're stopped at a fork/vfork, follow the branch set by the
2947 "set follow-fork-mode" command; otherwise, we'll just proceed
2948 resuming the current thread. */
2949 if (!follow_fork ())
2951 /* The target for some reason decided not to resume. */
2953 if (target_can_async_p ())
2954 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2958 /* We'll update this if & when we switch to a new thread. */
2959 previous_inferior_ptid = inferior_ptid;
2961 regcache = get_current_regcache ();
2962 gdbarch = get_regcache_arch (regcache);
2963 aspace = get_regcache_aspace (regcache);
2964 pc = regcache_read_pc (regcache);
2965 tp = inferior_thread ();
2967 /* Fill in with reasonable starting values. */
2968 init_thread_stepping_state (tp);
2970 gdb_assert (!thread_is_in_step_over_chain (tp));
2972 if (addr == (CORE_ADDR) -1)
2975 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2976 && execution_direction != EXEC_REVERSE)
2977 /* There is a breakpoint at the address we will resume at,
2978 step one instruction before inserting breakpoints so that
2979 we do not stop right away (and report a second hit at this
2982 Note, we don't do this in reverse, because we won't
2983 actually be executing the breakpoint insn anyway.
2984 We'll be (un-)executing the previous instruction. */
2985 tp->stepping_over_breakpoint = 1;
2986 else if (gdbarch_single_step_through_delay_p (gdbarch)
2987 && gdbarch_single_step_through_delay (gdbarch,
2988 get_current_frame ()))
2989 /* We stepped onto an instruction that needs to be stepped
2990 again before re-inserting the breakpoint, do so. */
2991 tp->stepping_over_breakpoint = 1;
2995 regcache_write_pc (regcache, addr);
2998 if (siggnal != GDB_SIGNAL_DEFAULT)
2999 tp->suspend.stop_signal = siggnal;
3001 /* Record the interpreter that issued the execution command that
3002 caused this thread to resume. If the top level interpreter is
3003 MI/async, and the execution command was a CLI command
3004 (next/step/etc.), we'll want to print stop event output to the MI
3005 console channel (the stepped-to line, etc.), as if the user
3006 entered the execution command on a real GDB console. */
3007 tp->control.command_interp = command_interp ();
3009 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3011 /* If an exception is thrown from this point on, make sure to
3012 propagate GDB's knowledge of the executing state to the
3013 frontend/user running state. */
3014 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
3016 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3017 threads (e.g., we might need to set threads stepping over
3018 breakpoints first), from the user/frontend's point of view, all
3019 threads in RESUME_PTID are now running. Unless we're calling an
3020 inferior function, as in that case we pretend the inferior
3021 doesn't run at all. */
3022 if (!tp->control.in_infcall)
3023 set_running (resume_ptid, 1);
3026 fprintf_unfiltered (gdb_stdlog,
3027 "infrun: proceed (addr=%s, signal=%s)\n",
3028 paddress (gdbarch, addr),
3029 gdb_signal_to_symbol_string (siggnal));
3031 annotate_starting ();
3033 /* Make sure that output from GDB appears before output from the
3035 gdb_flush (gdb_stdout);
3037 /* In a multi-threaded task we may select another thread and
3038 then continue or step.
3040 But if a thread that we're resuming had stopped at a breakpoint,
3041 it will immediately cause another breakpoint stop without any
3042 execution (i.e. it will report a breakpoint hit incorrectly). So
3043 we must step over it first.
3045 Look for threads other than the current (TP) that reported a
3046 breakpoint hit and haven't been resumed yet since. */
3048 /* If scheduler locking applies, we can avoid iterating over all
3050 if (!non_stop && !schedlock_applies (tp))
3052 struct thread_info *current = tp;
3054 ALL_NON_EXITED_THREADS (tp)
3056 /* Ignore the current thread here. It's handled
3061 /* Ignore threads of processes we're not resuming. */
3062 if (!ptid_match (tp->ptid, resume_ptid))
3065 if (!thread_still_needs_step_over (tp))
3068 gdb_assert (!thread_is_in_step_over_chain (tp));
3071 fprintf_unfiltered (gdb_stdlog,
3072 "infrun: need to step-over [%s] first\n",
3073 target_pid_to_str (tp->ptid));
3075 thread_step_over_chain_enqueue (tp);
3081 /* Enqueue the current thread last, so that we move all other
3082 threads over their breakpoints first. */
3083 if (tp->stepping_over_breakpoint)
3084 thread_step_over_chain_enqueue (tp);
3086 /* If the thread isn't started, we'll still need to set its prev_pc,
3087 so that switch_back_to_stepped_thread knows the thread hasn't
3088 advanced. Must do this before resuming any thread, as in
3089 all-stop/remote, once we resume we can't send any other packet
3090 until the target stops again. */
3091 tp->prev_pc = regcache_read_pc (regcache);
3093 started = start_step_over ();
3095 if (step_over_info_valid_p ())
3097 /* Either this thread started a new in-line step over, or some
3098 other thread was already doing one. In either case, don't
3099 resume anything else until the step-over is finished. */
3101 else if (started && !target_is_non_stop_p ())
3103 /* A new displaced stepping sequence was started. In all-stop,
3104 we can't talk to the target anymore until it next stops. */
3106 else if (!non_stop && target_is_non_stop_p ())
3108 /* In all-stop, but the target is always in non-stop mode.
3109 Start all other threads that are implicitly resumed too. */
3110 ALL_NON_EXITED_THREADS (tp)
3112 /* Ignore threads of processes we're not resuming. */
3113 if (!ptid_match (tp->ptid, resume_ptid))
3119 fprintf_unfiltered (gdb_stdlog,
3120 "infrun: proceed: [%s] resumed\n",
3121 target_pid_to_str (tp->ptid));
3122 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3126 if (thread_is_in_step_over_chain (tp))
3129 fprintf_unfiltered (gdb_stdlog,
3130 "infrun: proceed: [%s] needs step-over\n",
3131 target_pid_to_str (tp->ptid));
3136 fprintf_unfiltered (gdb_stdlog,
3137 "infrun: proceed: resuming %s\n",
3138 target_pid_to_str (tp->ptid));
3140 reset_ecs (ecs, tp);
3141 switch_to_thread (tp->ptid);
3142 keep_going_pass_signal (ecs);
3143 if (!ecs->wait_some_more)
3144 error (_("Command aborted."));
3147 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3149 /* The thread wasn't started, and isn't queued, run it now. */
3150 reset_ecs (ecs, tp);
3151 switch_to_thread (tp->ptid);
3152 keep_going_pass_signal (ecs);
3153 if (!ecs->wait_some_more)
3154 error (_("Command aborted."));
3157 discard_cleanups (old_chain);
3159 /* Tell the event loop to wait for it to stop. If the target
3160 supports asynchronous execution, it'll do this from within
3162 if (!target_can_async_p ())
3163 mark_async_event_handler (infrun_async_inferior_event_token);
3167 /* Start remote-debugging of a machine over a serial link. */
3170 start_remote (int from_tty)
3172 struct inferior *inferior;
3174 inferior = current_inferior ();
3175 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3177 /* Always go on waiting for the target, regardless of the mode. */
3178 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3179 indicate to wait_for_inferior that a target should timeout if
3180 nothing is returned (instead of just blocking). Because of this,
3181 targets expecting an immediate response need to, internally, set
3182 things up so that the target_wait() is forced to eventually
3184 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3185 differentiate to its caller what the state of the target is after
3186 the initial open has been performed. Here we're assuming that
3187 the target has stopped. It should be possible to eventually have
3188 target_open() return to the caller an indication that the target
3189 is currently running and GDB state should be set to the same as
3190 for an async run. */
3191 wait_for_inferior ();
3193 /* Now that the inferior has stopped, do any bookkeeping like
3194 loading shared libraries. We want to do this before normal_stop,
3195 so that the displayed frame is up to date. */
3196 post_create_inferior (¤t_target, from_tty);
3201 /* Initialize static vars when a new inferior begins. */
3204 init_wait_for_inferior (void)
3206 /* These are meaningless until the first time through wait_for_inferior. */
3208 breakpoint_init_inferior (inf_starting);
3210 clear_proceed_status (0);
3212 target_last_wait_ptid = minus_one_ptid;
3214 previous_inferior_ptid = inferior_ptid;
3216 /* Discard any skipped inlined frames. */
3217 clear_inline_frame_state (minus_one_ptid);
3222 static void handle_inferior_event (struct execution_control_state *ecs);
3224 static void handle_step_into_function (struct gdbarch *gdbarch,
3225 struct execution_control_state *ecs);
3226 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3227 struct execution_control_state *ecs);
3228 static void handle_signal_stop (struct execution_control_state *ecs);
3229 static void check_exception_resume (struct execution_control_state *,
3230 struct frame_info *);
3232 static void end_stepping_range (struct execution_control_state *ecs);
3233 static void stop_waiting (struct execution_control_state *ecs);
3234 static void keep_going (struct execution_control_state *ecs);
3235 static void process_event_stop_test (struct execution_control_state *ecs);
3236 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3238 /* Callback for iterate over threads. If the thread is stopped, but
3239 the user/frontend doesn't know about that yet, go through
3240 normal_stop, as if the thread had just stopped now. ARG points at
3241 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
3242 ptid_is_pid(PTID) is true, applies to all threads of the process
3243 pointed at by PTID. Otherwise, apply only to the thread pointed by
3247 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
3249 ptid_t ptid = * (ptid_t *) arg;
3251 if ((ptid_equal (info->ptid, ptid)
3252 || ptid_equal (minus_one_ptid, ptid)
3253 || (ptid_is_pid (ptid)
3254 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
3255 && is_running (info->ptid)
3256 && !is_executing (info->ptid))
3258 struct cleanup *old_chain;
3259 struct execution_control_state ecss;
3260 struct execution_control_state *ecs = &ecss;
3262 memset (ecs, 0, sizeof (*ecs));
3264 old_chain = make_cleanup_restore_current_thread ();
3266 overlay_cache_invalid = 1;
3267 /* Flush target cache before starting to handle each event.
3268 Target was running and cache could be stale. This is just a
3269 heuristic. Running threads may modify target memory, but we
3270 don't get any event. */
3271 target_dcache_invalidate ();
3273 /* Go through handle_inferior_event/normal_stop, so we always
3274 have consistent output as if the stop event had been
3276 ecs->ptid = info->ptid;
3277 ecs->event_thread = info;
3278 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
3279 ecs->ws.value.sig = GDB_SIGNAL_0;
3281 handle_inferior_event (ecs);
3283 if (!ecs->wait_some_more)
3285 /* Cancel any running execution command. */
3286 thread_cancel_execution_command (info);
3291 do_cleanups (old_chain);
3297 /* This function is attached as a "thread_stop_requested" observer.
3298 Cleanup local state that assumed the PTID was to be resumed, and
3299 report the stop to the frontend. */
3302 infrun_thread_stop_requested (ptid_t ptid)
3304 struct thread_info *tp;
3306 /* PTID was requested to stop. Remove matching threads from the
3307 step-over queue, so we don't try to resume them
3309 ALL_NON_EXITED_THREADS (tp)
3310 if (ptid_match (tp->ptid, ptid))
3312 if (thread_is_in_step_over_chain (tp))
3313 thread_step_over_chain_remove (tp);
3316 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
3320 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3322 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3323 nullify_last_target_wait_ptid ();
3326 /* Delete the step resume, single-step and longjmp/exception resume
3327 breakpoints of TP. */
3330 delete_thread_infrun_breakpoints (struct thread_info *tp)
3332 delete_step_resume_breakpoint (tp);
3333 delete_exception_resume_breakpoint (tp);
3334 delete_single_step_breakpoints (tp);
3337 /* If the target still has execution, call FUNC for each thread that
3338 just stopped. In all-stop, that's all the non-exited threads; in
3339 non-stop, that's the current thread, only. */
3341 typedef void (*for_each_just_stopped_thread_callback_func)
3342 (struct thread_info *tp);
3345 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3347 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3350 if (target_is_non_stop_p ())
3352 /* If in non-stop mode, only the current thread stopped. */
3353 func (inferior_thread ());
3357 struct thread_info *tp;
3359 /* In all-stop mode, all threads have stopped. */
3360 ALL_NON_EXITED_THREADS (tp)
3367 /* Delete the step resume and longjmp/exception resume breakpoints of
3368 the threads that just stopped. */
3371 delete_just_stopped_threads_infrun_breakpoints (void)
3373 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3376 /* Delete the single-step breakpoints of the threads that just
3380 delete_just_stopped_threads_single_step_breakpoints (void)
3382 for_each_just_stopped_thread (delete_single_step_breakpoints);
3385 /* A cleanup wrapper. */
3388 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3390 delete_just_stopped_threads_infrun_breakpoints ();
3396 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3397 const struct target_waitstatus *ws)
3399 char *status_string = target_waitstatus_to_string (ws);
3400 struct ui_file *tmp_stream = mem_fileopen ();
3403 /* The text is split over several lines because it was getting too long.
3404 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3405 output as a unit; we want only one timestamp printed if debug_timestamp
3408 fprintf_unfiltered (tmp_stream,
3409 "infrun: target_wait (%d.%ld.%ld",
3410 ptid_get_pid (waiton_ptid),
3411 ptid_get_lwp (waiton_ptid),
3412 ptid_get_tid (waiton_ptid));
3413 if (ptid_get_pid (waiton_ptid) != -1)
3414 fprintf_unfiltered (tmp_stream,
3415 " [%s]", target_pid_to_str (waiton_ptid));
3416 fprintf_unfiltered (tmp_stream, ", status) =\n");
3417 fprintf_unfiltered (tmp_stream,
3418 "infrun: %d.%ld.%ld [%s],\n",
3419 ptid_get_pid (result_ptid),
3420 ptid_get_lwp (result_ptid),
3421 ptid_get_tid (result_ptid),
3422 target_pid_to_str (result_ptid));
3423 fprintf_unfiltered (tmp_stream,
3427 text = ui_file_xstrdup (tmp_stream, NULL);
3429 /* This uses %s in part to handle %'s in the text, but also to avoid
3430 a gcc error: the format attribute requires a string literal. */
3431 fprintf_unfiltered (gdb_stdlog, "%s", text);
3433 xfree (status_string);
3435 ui_file_delete (tmp_stream);
3438 /* Select a thread at random, out of those which are resumed and have
3441 static struct thread_info *
3442 random_pending_event_thread (ptid_t waiton_ptid)
3444 struct thread_info *event_tp;
3446 int random_selector;
3448 /* First see how many events we have. Count only resumed threads
3449 that have an event pending. */
3450 ALL_NON_EXITED_THREADS (event_tp)
3451 if (ptid_match (event_tp->ptid, waiton_ptid)
3452 && event_tp->resumed
3453 && event_tp->suspend.waitstatus_pending_p)
3456 if (num_events == 0)
3459 /* Now randomly pick a thread out of those that have had events. */
3460 random_selector = (int)
3461 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3463 if (debug_infrun && num_events > 1)
3464 fprintf_unfiltered (gdb_stdlog,
3465 "infrun: Found %d events, selecting #%d\n",
3466 num_events, random_selector);
3468 /* Select the Nth thread that has had an event. */
3469 ALL_NON_EXITED_THREADS (event_tp)
3470 if (ptid_match (event_tp->ptid, waiton_ptid)
3471 && event_tp->resumed
3472 && event_tp->suspend.waitstatus_pending_p)
3473 if (random_selector-- == 0)
3479 /* Wrapper for target_wait that first checks whether threads have
3480 pending statuses to report before actually asking the target for
3484 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3487 struct thread_info *tp;
3489 /* First check if there is a resumed thread with a wait status
3491 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3493 tp = random_pending_event_thread (ptid);
3498 fprintf_unfiltered (gdb_stdlog,
3499 "infrun: Waiting for specific thread %s.\n",
3500 target_pid_to_str (ptid));
3502 /* We have a specific thread to check. */
3503 tp = find_thread_ptid (ptid);
3504 gdb_assert (tp != NULL);
3505 if (!tp->suspend.waitstatus_pending_p)
3510 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3511 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3513 struct regcache *regcache = get_thread_regcache (tp->ptid);
3514 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3518 pc = regcache_read_pc (regcache);
3520 if (pc != tp->suspend.stop_pc)
3523 fprintf_unfiltered (gdb_stdlog,
3524 "infrun: PC of %s changed. was=%s, now=%s\n",
3525 target_pid_to_str (tp->ptid),
3526 paddress (gdbarch, tp->prev_pc),
3527 paddress (gdbarch, pc));
3530 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3533 fprintf_unfiltered (gdb_stdlog,
3534 "infrun: previous breakpoint of %s, at %s gone\n",
3535 target_pid_to_str (tp->ptid),
3536 paddress (gdbarch, pc));
3544 fprintf_unfiltered (gdb_stdlog,
3545 "infrun: pending event of %s cancelled.\n",
3546 target_pid_to_str (tp->ptid));
3548 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3549 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3559 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
3560 fprintf_unfiltered (gdb_stdlog,
3561 "infrun: Using pending wait status %s for %s.\n",
3563 target_pid_to_str (tp->ptid));
3567 /* Now that we've selected our final event LWP, un-adjust its PC
3568 if it was a software breakpoint (and the target doesn't
3569 always adjust the PC itself). */
3570 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3571 && !target_supports_stopped_by_sw_breakpoint ())
3573 struct regcache *regcache;
3574 struct gdbarch *gdbarch;
3577 regcache = get_thread_regcache (tp->ptid);
3578 gdbarch = get_regcache_arch (regcache);
3580 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3585 pc = regcache_read_pc (regcache);
3586 regcache_write_pc (regcache, pc + decr_pc);
3590 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3591 *status = tp->suspend.waitstatus;
3592 tp->suspend.waitstatus_pending_p = 0;
3594 /* Wake up the event loop again, until all pending events are
3596 if (target_is_async_p ())
3597 mark_async_event_handler (infrun_async_inferior_event_token);
3601 /* But if we don't find one, we'll have to wait. */
3603 if (deprecated_target_wait_hook)
3604 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3606 event_ptid = target_wait (ptid, status, options);
3611 /* Prepare and stabilize the inferior for detaching it. E.g.,
3612 detaching while a thread is displaced stepping is a recipe for
3613 crashing it, as nothing would readjust the PC out of the scratch
3617 prepare_for_detach (void)
3619 struct inferior *inf = current_inferior ();
3620 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3621 struct cleanup *old_chain_1;
3622 struct displaced_step_inferior_state *displaced;
3624 displaced = get_displaced_stepping_state (inf->pid);
3626 /* Is any thread of this process displaced stepping? If not,
3627 there's nothing else to do. */
3628 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3632 fprintf_unfiltered (gdb_stdlog,
3633 "displaced-stepping in-process while detaching");
3635 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3638 while (!ptid_equal (displaced->step_ptid, null_ptid))
3640 struct cleanup *old_chain_2;
3641 struct execution_control_state ecss;
3642 struct execution_control_state *ecs;
3645 memset (ecs, 0, sizeof (*ecs));
3647 overlay_cache_invalid = 1;
3648 /* Flush target cache before starting to handle each event.
3649 Target was running and cache could be stale. This is just a
3650 heuristic. Running threads may modify target memory, but we
3651 don't get any event. */
3652 target_dcache_invalidate ();
3654 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3657 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3659 /* If an error happens while handling the event, propagate GDB's
3660 knowledge of the executing state to the frontend/user running
3662 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3665 /* Now figure out what to do with the result of the result. */
3666 handle_inferior_event (ecs);
3668 /* No error, don't finish the state yet. */
3669 discard_cleanups (old_chain_2);
3671 /* Breakpoints and watchpoints are not installed on the target
3672 at this point, and signals are passed directly to the
3673 inferior, so this must mean the process is gone. */
3674 if (!ecs->wait_some_more)
3676 discard_cleanups (old_chain_1);
3677 error (_("Program exited while detaching"));
3681 discard_cleanups (old_chain_1);
3684 /* Wait for control to return from inferior to debugger.
3686 If inferior gets a signal, we may decide to start it up again
3687 instead of returning. That is why there is a loop in this function.
3688 When this function actually returns it means the inferior
3689 should be left stopped and GDB should read more commands. */
3692 wait_for_inferior (void)
3694 struct cleanup *old_cleanups;
3695 struct cleanup *thread_state_chain;
3699 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3702 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3705 /* If an error happens while handling the event, propagate GDB's
3706 knowledge of the executing state to the frontend/user running
3708 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3712 struct execution_control_state ecss;
3713 struct execution_control_state *ecs = &ecss;
3714 ptid_t waiton_ptid = minus_one_ptid;
3716 memset (ecs, 0, sizeof (*ecs));
3718 overlay_cache_invalid = 1;
3720 /* Flush target cache before starting to handle each event.
3721 Target was running and cache could be stale. This is just a
3722 heuristic. Running threads may modify target memory, but we
3723 don't get any event. */
3724 target_dcache_invalidate ();
3726 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3729 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3731 /* Now figure out what to do with the result of the result. */
3732 handle_inferior_event (ecs);
3734 if (!ecs->wait_some_more)
3738 /* No error, don't finish the state yet. */
3739 discard_cleanups (thread_state_chain);
3741 do_cleanups (old_cleanups);
3744 /* Cleanup that reinstalls the readline callback handler, if the
3745 target is running in the background. If while handling the target
3746 event something triggered a secondary prompt, like e.g., a
3747 pagination prompt, we'll have removed the callback handler (see
3748 gdb_readline_wrapper_line). Need to do this as we go back to the
3749 event loop, ready to process further input. Note this has no
3750 effect if the handler hasn't actually been removed, because calling
3751 rl_callback_handler_install resets the line buffer, thus losing
3755 reinstall_readline_callback_handler_cleanup (void *arg)
3757 if (!interpreter_async)
3759 /* We're not going back to the top level event loop yet. Don't
3760 install the readline callback, as it'd prep the terminal,
3761 readline-style (raw, noecho) (e.g., --batch). We'll install
3762 it the next time the prompt is displayed, when we're ready
3767 if (async_command_editing_p && !sync_execution)
3768 gdb_rl_callback_handler_reinstall ();
3771 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3772 that's just the event thread. In all-stop, that's all threads. */
3775 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3777 struct thread_info *thr = ecs->event_thread;
3779 if (thr != NULL && thr->thread_fsm != NULL)
3780 thread_fsm_clean_up (thr->thread_fsm);
3784 ALL_NON_EXITED_THREADS (thr)
3786 if (thr->thread_fsm == NULL)
3788 if (thr == ecs->event_thread)
3791 switch_to_thread (thr->ptid);
3792 thread_fsm_clean_up (thr->thread_fsm);
3795 if (ecs->event_thread != NULL)
3796 switch_to_thread (ecs->event_thread->ptid);
3800 /* Asynchronous version of wait_for_inferior. It is called by the
3801 event loop whenever a change of state is detected on the file
3802 descriptor corresponding to the target. It can be called more than
3803 once to complete a single execution command. In such cases we need
3804 to keep the state in a global variable ECSS. If it is the last time
3805 that this function is called for a single execution command, then
3806 report to the user that the inferior has stopped, and do the
3807 necessary cleanups. */
3810 fetch_inferior_event (void *client_data)
3812 struct execution_control_state ecss;
3813 struct execution_control_state *ecs = &ecss;
3814 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3815 struct cleanup *ts_old_chain;
3816 int was_sync = sync_execution;
3818 ptid_t waiton_ptid = minus_one_ptid;
3820 memset (ecs, 0, sizeof (*ecs));
3822 /* End up with readline processing input, if necessary. */
3823 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3825 /* We're handling a live event, so make sure we're doing live
3826 debugging. If we're looking at traceframes while the target is
3827 running, we're going to need to get back to that mode after
3828 handling the event. */
3831 make_cleanup_restore_current_traceframe ();
3832 set_current_traceframe (-1);
3836 /* In non-stop mode, the user/frontend should not notice a thread
3837 switch due to internal events. Make sure we reverse to the
3838 user selected thread and frame after handling the event and
3839 running any breakpoint commands. */
3840 make_cleanup_restore_current_thread ();
3842 overlay_cache_invalid = 1;
3843 /* Flush target cache before starting to handle each event. Target
3844 was running and cache could be stale. This is just a heuristic.
3845 Running threads may modify target memory, but we don't get any
3847 target_dcache_invalidate ();
3849 make_cleanup_restore_integer (&execution_direction);
3850 execution_direction = target_execution_direction ();
3852 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3853 target_can_async_p () ? TARGET_WNOHANG : 0);
3856 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3858 /* If an error happens while handling the event, propagate GDB's
3859 knowledge of the executing state to the frontend/user running
3861 if (!target_is_non_stop_p ())
3862 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3864 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3866 /* Get executed before make_cleanup_restore_current_thread above to apply
3867 still for the thread which has thrown the exception. */
3868 make_bpstat_clear_actions_cleanup ();
3870 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3872 /* Now figure out what to do with the result of the result. */
3873 handle_inferior_event (ecs);
3875 if (!ecs->wait_some_more)
3877 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3878 int should_stop = 1;
3879 struct thread_info *thr = ecs->event_thread;
3880 int should_notify_stop = 1;
3882 delete_just_stopped_threads_infrun_breakpoints ();
3886 struct thread_fsm *thread_fsm = thr->thread_fsm;
3888 if (thread_fsm != NULL)
3889 should_stop = thread_fsm_should_stop (thread_fsm);
3898 clean_up_just_stopped_threads_fsms (ecs);
3900 if (thr != NULL && thr->thread_fsm != NULL)
3903 = thread_fsm_should_notify_stop (thr->thread_fsm);
3906 if (should_notify_stop)
3910 /* We may not find an inferior if this was a process exit. */
3911 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3912 proceeded = normal_stop ();
3916 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3923 /* No error, don't finish the thread states yet. */
3924 discard_cleanups (ts_old_chain);
3926 /* Revert thread and frame. */
3927 do_cleanups (old_chain);
3929 /* If the inferior was in sync execution mode, and now isn't,
3930 restore the prompt (a synchronous execution command has finished,
3931 and we're ready for input). */
3932 if (interpreter_async && was_sync && !sync_execution)
3933 observer_notify_sync_execution_done ();
3937 && exec_done_display_p
3938 && (ptid_equal (inferior_ptid, null_ptid)
3939 || !is_running (inferior_ptid)))
3940 printf_unfiltered (_("completed.\n"));
3943 /* Record the frame and location we're currently stepping through. */
3945 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3947 struct thread_info *tp = inferior_thread ();
3949 tp->control.step_frame_id = get_frame_id (frame);
3950 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3952 tp->current_symtab = sal.symtab;
3953 tp->current_line = sal.line;
3956 /* Clear context switchable stepping state. */
3959 init_thread_stepping_state (struct thread_info *tss)
3961 tss->stepped_breakpoint = 0;
3962 tss->stepping_over_breakpoint = 0;
3963 tss->stepping_over_watchpoint = 0;
3964 tss->step_after_step_resume_breakpoint = 0;
3967 /* Set the cached copy of the last ptid/waitstatus. */
3970 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3972 target_last_wait_ptid = ptid;
3973 target_last_waitstatus = status;
3976 /* Return the cached copy of the last pid/waitstatus returned by
3977 target_wait()/deprecated_target_wait_hook(). The data is actually
3978 cached by handle_inferior_event(), which gets called immediately
3979 after target_wait()/deprecated_target_wait_hook(). */
3982 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3984 *ptidp = target_last_wait_ptid;
3985 *status = target_last_waitstatus;
3989 nullify_last_target_wait_ptid (void)
3991 target_last_wait_ptid = minus_one_ptid;
3994 /* Switch thread contexts. */
3997 context_switch (ptid_t ptid)
3999 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4001 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4002 target_pid_to_str (inferior_ptid));
4003 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4004 target_pid_to_str (ptid));
4007 switch_to_thread (ptid);
4010 /* If the target can't tell whether we've hit breakpoints
4011 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4012 check whether that could have been caused by a breakpoint. If so,
4013 adjust the PC, per gdbarch_decr_pc_after_break. */
4016 adjust_pc_after_break (struct thread_info *thread,
4017 struct target_waitstatus *ws)
4019 struct regcache *regcache;
4020 struct gdbarch *gdbarch;
4021 struct address_space *aspace;
4022 CORE_ADDR breakpoint_pc, decr_pc;
4024 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4025 we aren't, just return.
4027 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4028 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4029 implemented by software breakpoints should be handled through the normal
4032 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4033 different signals (SIGILL or SIGEMT for instance), but it is less
4034 clear where the PC is pointing afterwards. It may not match
4035 gdbarch_decr_pc_after_break. I don't know any specific target that
4036 generates these signals at breakpoints (the code has been in GDB since at
4037 least 1992) so I can not guess how to handle them here.
4039 In earlier versions of GDB, a target with
4040 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4041 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4042 target with both of these set in GDB history, and it seems unlikely to be
4043 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4045 if (ws->kind != TARGET_WAITKIND_STOPPED)
4048 if (ws->value.sig != GDB_SIGNAL_TRAP)
4051 /* In reverse execution, when a breakpoint is hit, the instruction
4052 under it has already been de-executed. The reported PC always
4053 points at the breakpoint address, so adjusting it further would
4054 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4057 B1 0x08000000 : INSN1
4058 B2 0x08000001 : INSN2
4060 PC -> 0x08000003 : INSN4
4062 Say you're stopped at 0x08000003 as above. Reverse continuing
4063 from that point should hit B2 as below. Reading the PC when the
4064 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4065 been de-executed already.
4067 B1 0x08000000 : INSN1
4068 B2 PC -> 0x08000001 : INSN2
4072 We can't apply the same logic as for forward execution, because
4073 we would wrongly adjust the PC to 0x08000000, since there's a
4074 breakpoint at PC - 1. We'd then report a hit on B1, although
4075 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4077 if (execution_direction == EXEC_REVERSE)
4080 /* If the target can tell whether the thread hit a SW breakpoint,
4081 trust it. Targets that can tell also adjust the PC
4083 if (target_supports_stopped_by_sw_breakpoint ())
4086 /* Note that relying on whether a breakpoint is planted in memory to
4087 determine this can fail. E.g,. the breakpoint could have been
4088 removed since. Or the thread could have been told to step an
4089 instruction the size of a breakpoint instruction, and only
4090 _after_ was a breakpoint inserted at its address. */
4092 /* If this target does not decrement the PC after breakpoints, then
4093 we have nothing to do. */
4094 regcache = get_thread_regcache (thread->ptid);
4095 gdbarch = get_regcache_arch (regcache);
4097 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4101 aspace = get_regcache_aspace (regcache);
4103 /* Find the location where (if we've hit a breakpoint) the
4104 breakpoint would be. */
4105 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4107 /* If the target can't tell whether a software breakpoint triggered,
4108 fallback to figuring it out based on breakpoints we think were
4109 inserted in the target, and on whether the thread was stepped or
4112 /* Check whether there actually is a software breakpoint inserted at
4115 If in non-stop mode, a race condition is possible where we've
4116 removed a breakpoint, but stop events for that breakpoint were
4117 already queued and arrive later. To suppress those spurious
4118 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4119 and retire them after a number of stop events are reported. Note
4120 this is an heuristic and can thus get confused. The real fix is
4121 to get the "stopped by SW BP and needs adjustment" info out of
4122 the target/kernel (and thus never reach here; see above). */
4123 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4124 || (target_is_non_stop_p ()
4125 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4127 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4129 if (record_full_is_used ())
4130 record_full_gdb_operation_disable_set ();
4132 /* When using hardware single-step, a SIGTRAP is reported for both
4133 a completed single-step and a software breakpoint. Need to
4134 differentiate between the two, as the latter needs adjusting
4135 but the former does not.
4137 The SIGTRAP can be due to a completed hardware single-step only if
4138 - we didn't insert software single-step breakpoints
4139 - this thread is currently being stepped
4141 If any of these events did not occur, we must have stopped due
4142 to hitting a software breakpoint, and have to back up to the
4145 As a special case, we could have hardware single-stepped a
4146 software breakpoint. In this case (prev_pc == breakpoint_pc),
4147 we also need to back up to the breakpoint address. */
4149 if (thread_has_single_step_breakpoints_set (thread)
4150 || !currently_stepping (thread)
4151 || (thread->stepped_breakpoint
4152 && thread->prev_pc == breakpoint_pc))
4153 regcache_write_pc (regcache, breakpoint_pc);
4155 do_cleanups (old_cleanups);
4160 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4162 for (frame = get_prev_frame (frame);
4164 frame = get_prev_frame (frame))
4166 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4168 if (get_frame_type (frame) != INLINE_FRAME)
4175 /* Auxiliary function that handles syscall entry/return events.
4176 It returns 1 if the inferior should keep going (and GDB
4177 should ignore the event), or 0 if the event deserves to be
4181 handle_syscall_event (struct execution_control_state *ecs)
4183 struct regcache *regcache;
4186 if (!ptid_equal (ecs->ptid, inferior_ptid))
4187 context_switch (ecs->ptid);
4189 regcache = get_thread_regcache (ecs->ptid);
4190 syscall_number = ecs->ws.value.syscall_number;
4191 stop_pc = regcache_read_pc (regcache);
4193 if (catch_syscall_enabled () > 0
4194 && catching_syscall_number (syscall_number) > 0)
4197 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4200 ecs->event_thread->control.stop_bpstat
4201 = bpstat_stop_status (get_regcache_aspace (regcache),
4202 stop_pc, ecs->ptid, &ecs->ws);
4204 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4206 /* Catchpoint hit. */
4211 /* If no catchpoint triggered for this, then keep going. */
4216 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4219 fill_in_stop_func (struct gdbarch *gdbarch,
4220 struct execution_control_state *ecs)
4222 if (!ecs->stop_func_filled_in)
4224 /* Don't care about return value; stop_func_start and stop_func_name
4225 will both be 0 if it doesn't work. */
4226 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4227 &ecs->stop_func_start, &ecs->stop_func_end);
4228 ecs->stop_func_start
4229 += gdbarch_deprecated_function_start_offset (gdbarch);
4231 if (gdbarch_skip_entrypoint_p (gdbarch))
4232 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4233 ecs->stop_func_start);
4235 ecs->stop_func_filled_in = 1;
4240 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4242 static enum stop_kind
4243 get_inferior_stop_soon (ptid_t ptid)
4245 struct inferior *inf = find_inferior_ptid (ptid);
4247 gdb_assert (inf != NULL);
4248 return inf->control.stop_soon;
4251 /* Wait for one event. Store the resulting waitstatus in WS, and
4252 return the event ptid. */
4255 wait_one (struct target_waitstatus *ws)
4258 ptid_t wait_ptid = minus_one_ptid;
4260 overlay_cache_invalid = 1;
4262 /* Flush target cache before starting to handle each event.
4263 Target was running and cache could be stale. This is just a
4264 heuristic. Running threads may modify target memory, but we
4265 don't get any event. */
4266 target_dcache_invalidate ();
4268 if (deprecated_target_wait_hook)
4269 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4271 event_ptid = target_wait (wait_ptid, ws, 0);
4274 print_target_wait_results (wait_ptid, event_ptid, ws);
4279 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4280 instead of the current thread. */
4281 #define THREAD_STOPPED_BY(REASON) \
4283 thread_stopped_by_ ## REASON (ptid_t ptid) \
4285 struct cleanup *old_chain; \
4288 old_chain = save_inferior_ptid (); \
4289 inferior_ptid = ptid; \
4291 res = target_stopped_by_ ## REASON (); \
4293 do_cleanups (old_chain); \
4298 /* Generate thread_stopped_by_watchpoint. */
4299 THREAD_STOPPED_BY (watchpoint)
4300 /* Generate thread_stopped_by_sw_breakpoint. */
4301 THREAD_STOPPED_BY (sw_breakpoint)
4302 /* Generate thread_stopped_by_hw_breakpoint. */
4303 THREAD_STOPPED_BY (hw_breakpoint)
4305 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4308 switch_to_thread_cleanup (void *ptid_p)
4310 ptid_t ptid = *(ptid_t *) ptid_p;
4312 switch_to_thread (ptid);
4315 /* Save the thread's event and stop reason to process it later. */
4318 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4320 struct regcache *regcache;
4321 struct address_space *aspace;
4327 statstr = target_waitstatus_to_string (ws);
4328 fprintf_unfiltered (gdb_stdlog,
4329 "infrun: saving status %s for %d.%ld.%ld\n",
4331 ptid_get_pid (tp->ptid),
4332 ptid_get_lwp (tp->ptid),
4333 ptid_get_tid (tp->ptid));
4337 /* Record for later. */
4338 tp->suspend.waitstatus = *ws;
4339 tp->suspend.waitstatus_pending_p = 1;
4341 regcache = get_thread_regcache (tp->ptid);
4342 aspace = get_regcache_aspace (regcache);
4344 if (ws->kind == TARGET_WAITKIND_STOPPED
4345 && ws->value.sig == GDB_SIGNAL_TRAP)
4347 CORE_ADDR pc = regcache_read_pc (regcache);
4349 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4351 if (thread_stopped_by_watchpoint (tp->ptid))
4353 tp->suspend.stop_reason
4354 = TARGET_STOPPED_BY_WATCHPOINT;
4356 else if (target_supports_stopped_by_sw_breakpoint ()
4357 && thread_stopped_by_sw_breakpoint (tp->ptid))
4359 tp->suspend.stop_reason
4360 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4362 else if (target_supports_stopped_by_hw_breakpoint ()
4363 && thread_stopped_by_hw_breakpoint (tp->ptid))
4365 tp->suspend.stop_reason
4366 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4368 else if (!target_supports_stopped_by_hw_breakpoint ()
4369 && hardware_breakpoint_inserted_here_p (aspace,
4372 tp->suspend.stop_reason
4373 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4375 else if (!target_supports_stopped_by_sw_breakpoint ()
4376 && software_breakpoint_inserted_here_p (aspace,
4379 tp->suspend.stop_reason
4380 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4382 else if (!thread_has_single_step_breakpoints_set (tp)
4383 && currently_stepping (tp))
4385 tp->suspend.stop_reason
4386 = TARGET_STOPPED_BY_SINGLE_STEP;
4391 /* Stop all threads. */
4394 stop_all_threads (void)
4396 /* We may need multiple passes to discover all threads. */
4400 struct cleanup *old_chain;
4402 gdb_assert (target_is_non_stop_p ());
4405 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4407 entry_ptid = inferior_ptid;
4408 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4410 /* Request threads to stop, and then wait for the stops. Because
4411 threads we already know about can spawn more threads while we're
4412 trying to stop them, and we only learn about new threads when we
4413 update the thread list, do this in a loop, and keep iterating
4414 until two passes find no threads that need to be stopped. */
4415 for (pass = 0; pass < 2; pass++, iterations++)
4418 fprintf_unfiltered (gdb_stdlog,
4419 "infrun: stop_all_threads, pass=%d, "
4420 "iterations=%d\n", pass, iterations);
4424 struct target_waitstatus ws;
4426 struct thread_info *t;
4428 update_thread_list ();
4430 /* Go through all threads looking for threads that we need
4431 to tell the target to stop. */
4432 ALL_NON_EXITED_THREADS (t)
4436 /* If already stopping, don't request a stop again.
4437 We just haven't seen the notification yet. */
4438 if (!t->stop_requested)
4441 fprintf_unfiltered (gdb_stdlog,
4442 "infrun: %s executing, "
4444 target_pid_to_str (t->ptid));
4445 target_stop (t->ptid);
4446 t->stop_requested = 1;
4451 fprintf_unfiltered (gdb_stdlog,
4452 "infrun: %s executing, "
4453 "already stopping\n",
4454 target_pid_to_str (t->ptid));
4457 if (t->stop_requested)
4463 fprintf_unfiltered (gdb_stdlog,
4464 "infrun: %s not executing\n",
4465 target_pid_to_str (t->ptid));
4467 /* The thread may be not executing, but still be
4468 resumed with a pending status to process. */
4476 /* If we find new threads on the second iteration, restart
4477 over. We want to see two iterations in a row with all
4482 event_ptid = wait_one (&ws);
4483 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4485 /* All resumed threads exited. */
4487 else if (ws.kind == TARGET_WAITKIND_EXITED
4488 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4492 ptid_t ptid = pid_to_ptid (ws.value.integer);
4494 fprintf_unfiltered (gdb_stdlog,
4495 "infrun: %s exited while "
4496 "stopping threads\n",
4497 target_pid_to_str (ptid));
4502 t = find_thread_ptid (event_ptid);
4504 t = add_thread (event_ptid);
4506 t->stop_requested = 0;
4509 t->control.may_range_step = 0;
4511 if (ws.kind == TARGET_WAITKIND_STOPPED
4512 && ws.value.sig == GDB_SIGNAL_0)
4514 /* We caught the event that we intended to catch, so
4515 there's no event pending. */
4516 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4517 t->suspend.waitstatus_pending_p = 0;
4519 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4521 /* Add it back to the step-over queue. */
4524 fprintf_unfiltered (gdb_stdlog,
4525 "infrun: displaced-step of %s "
4526 "canceled: adding back to the "
4527 "step-over queue\n",
4528 target_pid_to_str (t->ptid));
4530 t->control.trap_expected = 0;
4531 thread_step_over_chain_enqueue (t);
4536 enum gdb_signal sig;
4537 struct regcache *regcache;
4538 struct address_space *aspace;
4544 statstr = target_waitstatus_to_string (&ws);
4545 fprintf_unfiltered (gdb_stdlog,
4546 "infrun: target_wait %s, saving "
4547 "status for %d.%ld.%ld\n",
4549 ptid_get_pid (t->ptid),
4550 ptid_get_lwp (t->ptid),
4551 ptid_get_tid (t->ptid));
4555 /* Record for later. */
4556 save_waitstatus (t, &ws);
4558 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4559 ? ws.value.sig : GDB_SIGNAL_0);
4561 if (displaced_step_fixup (t->ptid, sig) < 0)
4563 /* Add it back to the step-over queue. */
4564 t->control.trap_expected = 0;
4565 thread_step_over_chain_enqueue (t);
4568 regcache = get_thread_regcache (t->ptid);
4569 t->suspend.stop_pc = regcache_read_pc (regcache);
4573 fprintf_unfiltered (gdb_stdlog,
4574 "infrun: saved stop_pc=%s for %s "
4575 "(currently_stepping=%d)\n",
4576 paddress (target_gdbarch (),
4577 t->suspend.stop_pc),
4578 target_pid_to_str (t->ptid),
4579 currently_stepping (t));
4586 do_cleanups (old_chain);
4589 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4592 /* Given an execution control state that has been freshly filled in by
4593 an event from the inferior, figure out what it means and take
4596 The alternatives are:
4598 1) stop_waiting and return; to really stop and return to the
4601 2) keep_going and return; to wait for the next event (set
4602 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4606 handle_inferior_event_1 (struct execution_control_state *ecs)
4608 enum stop_kind stop_soon;
4610 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4612 /* We had an event in the inferior, but we are not interested in
4613 handling it at this level. The lower layers have already
4614 done what needs to be done, if anything.
4616 One of the possible circumstances for this is when the
4617 inferior produces output for the console. The inferior has
4618 not stopped, and we are ignoring the event. Another possible
4619 circumstance is any event which the lower level knows will be
4620 reported multiple times without an intervening resume. */
4622 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4623 prepare_to_wait (ecs);
4627 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4628 && target_can_async_p () && !sync_execution)
4630 /* There were no unwaited-for children left in the target, but,
4631 we're not synchronously waiting for events either. Just
4632 ignore. Otherwise, if we were running a synchronous
4633 execution command, we need to cancel it and give the user
4634 back the terminal. */
4636 fprintf_unfiltered (gdb_stdlog,
4637 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
4638 prepare_to_wait (ecs);
4642 /* Cache the last pid/waitstatus. */
4643 set_last_target_status (ecs->ptid, ecs->ws);
4645 /* Always clear state belonging to the previous time we stopped. */
4646 stop_stack_dummy = STOP_NONE;
4648 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4650 /* No unwaited-for children left. IOW, all resumed children
4653 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4655 stop_print_frame = 0;
4660 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4661 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4663 ecs->event_thread = find_thread_ptid (ecs->ptid);
4664 /* If it's a new thread, add it to the thread database. */
4665 if (ecs->event_thread == NULL)
4666 ecs->event_thread = add_thread (ecs->ptid);
4668 /* Disable range stepping. If the next step request could use a
4669 range, this will be end up re-enabled then. */
4670 ecs->event_thread->control.may_range_step = 0;
4673 /* Dependent on valid ECS->EVENT_THREAD. */
4674 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4676 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4677 reinit_frame_cache ();
4679 breakpoint_retire_moribund ();
4681 /* First, distinguish signals caused by the debugger from signals
4682 that have to do with the program's own actions. Note that
4683 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4684 on the operating system version. Here we detect when a SIGILL or
4685 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4686 something similar for SIGSEGV, since a SIGSEGV will be generated
4687 when we're trying to execute a breakpoint instruction on a
4688 non-executable stack. This happens for call dummy breakpoints
4689 for architectures like SPARC that place call dummies on the
4691 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4692 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4693 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4694 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4696 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4698 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
4699 regcache_read_pc (regcache)))
4702 fprintf_unfiltered (gdb_stdlog,
4703 "infrun: Treating signal as SIGTRAP\n");
4704 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4708 /* Mark the non-executing threads accordingly. In all-stop, all
4709 threads of all processes are stopped when we get any event
4710 reported. In non-stop mode, only the event thread stops. */
4714 if (!target_is_non_stop_p ())
4715 mark_ptid = minus_one_ptid;
4716 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4717 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4719 /* If we're handling a process exit in non-stop mode, even
4720 though threads haven't been deleted yet, one would think
4721 that there is nothing to do, as threads of the dead process
4722 will be soon deleted, and threads of any other process were
4723 left running. However, on some targets, threads survive a
4724 process exit event. E.g., for the "checkpoint" command,
4725 when the current checkpoint/fork exits, linux-fork.c
4726 automatically switches to another fork from within
4727 target_mourn_inferior, by associating the same
4728 inferior/thread to another fork. We haven't mourned yet at
4729 this point, but we must mark any threads left in the
4730 process as not-executing so that finish_thread_state marks
4731 them stopped (in the user's perspective) if/when we present
4732 the stop to the user. */
4733 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4736 mark_ptid = ecs->ptid;
4738 set_executing (mark_ptid, 0);
4740 /* Likewise the resumed flag. */
4741 set_resumed (mark_ptid, 0);
4744 switch (ecs->ws.kind)
4746 case TARGET_WAITKIND_LOADED:
4748 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4749 if (!ptid_equal (ecs->ptid, inferior_ptid))
4750 context_switch (ecs->ptid);
4751 /* Ignore gracefully during startup of the inferior, as it might
4752 be the shell which has just loaded some objects, otherwise
4753 add the symbols for the newly loaded objects. Also ignore at
4754 the beginning of an attach or remote session; we will query
4755 the full list of libraries once the connection is
4758 stop_soon = get_inferior_stop_soon (ecs->ptid);
4759 if (stop_soon == NO_STOP_QUIETLY)
4761 struct regcache *regcache;
4763 regcache = get_thread_regcache (ecs->ptid);
4765 handle_solib_event ();
4767 ecs->event_thread->control.stop_bpstat
4768 = bpstat_stop_status (get_regcache_aspace (regcache),
4769 stop_pc, ecs->ptid, &ecs->ws);
4771 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4773 /* A catchpoint triggered. */
4774 process_event_stop_test (ecs);
4778 /* If requested, stop when the dynamic linker notifies
4779 gdb of events. This allows the user to get control
4780 and place breakpoints in initializer routines for
4781 dynamically loaded objects (among other things). */
4782 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4783 if (stop_on_solib_events)
4785 /* Make sure we print "Stopped due to solib-event" in
4787 stop_print_frame = 1;
4794 /* If we are skipping through a shell, or through shared library
4795 loading that we aren't interested in, resume the program. If
4796 we're running the program normally, also resume. */
4797 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4799 /* Loading of shared libraries might have changed breakpoint
4800 addresses. Make sure new breakpoints are inserted. */
4801 if (stop_soon == NO_STOP_QUIETLY)
4802 insert_breakpoints ();
4803 resume (GDB_SIGNAL_0);
4804 prepare_to_wait (ecs);
4808 /* But stop if we're attaching or setting up a remote
4810 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4811 || stop_soon == STOP_QUIETLY_REMOTE)
4814 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4819 internal_error (__FILE__, __LINE__,
4820 _("unhandled stop_soon: %d"), (int) stop_soon);
4822 case TARGET_WAITKIND_SPURIOUS:
4824 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4825 if (!ptid_equal (ecs->ptid, inferior_ptid))
4826 context_switch (ecs->ptid);
4827 resume (GDB_SIGNAL_0);
4828 prepare_to_wait (ecs);
4831 case TARGET_WAITKIND_EXITED:
4832 case TARGET_WAITKIND_SIGNALLED:
4835 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4836 fprintf_unfiltered (gdb_stdlog,
4837 "infrun: TARGET_WAITKIND_EXITED\n");
4839 fprintf_unfiltered (gdb_stdlog,
4840 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4843 inferior_ptid = ecs->ptid;
4844 set_current_inferior (find_inferior_ptid (ecs->ptid));
4845 set_current_program_space (current_inferior ()->pspace);
4846 handle_vfork_child_exec_or_exit (0);
4847 target_terminal_ours (); /* Must do this before mourn anyway. */
4849 /* Clearing any previous state of convenience variables. */
4850 clear_exit_convenience_vars ();
4852 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4854 /* Record the exit code in the convenience variable $_exitcode, so
4855 that the user can inspect this again later. */
4856 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4857 (LONGEST) ecs->ws.value.integer);
4859 /* Also record this in the inferior itself. */
4860 current_inferior ()->has_exit_code = 1;
4861 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4863 /* Support the --return-child-result option. */
4864 return_child_result_value = ecs->ws.value.integer;
4866 observer_notify_exited (ecs->ws.value.integer);
4870 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4871 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4873 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4875 /* Set the value of the internal variable $_exitsignal,
4876 which holds the signal uncaught by the inferior. */
4877 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4878 gdbarch_gdb_signal_to_target (gdbarch,
4879 ecs->ws.value.sig));
4883 /* We don't have access to the target's method used for
4884 converting between signal numbers (GDB's internal
4885 representation <-> target's representation).
4886 Therefore, we cannot do a good job at displaying this
4887 information to the user. It's better to just warn
4888 her about it (if infrun debugging is enabled), and
4891 fprintf_filtered (gdb_stdlog, _("\
4892 Cannot fill $_exitsignal with the correct signal number.\n"));
4895 observer_notify_signal_exited (ecs->ws.value.sig);
4898 gdb_flush (gdb_stdout);
4899 target_mourn_inferior ();
4900 stop_print_frame = 0;
4904 /* The following are the only cases in which we keep going;
4905 the above cases end in a continue or goto. */
4906 case TARGET_WAITKIND_FORKED:
4907 case TARGET_WAITKIND_VFORKED:
4910 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4911 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4913 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4916 /* Check whether the inferior is displaced stepping. */
4918 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4919 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4920 struct displaced_step_inferior_state *displaced
4921 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
4923 /* If checking displaced stepping is supported, and thread
4924 ecs->ptid is displaced stepping. */
4925 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
4927 struct inferior *parent_inf
4928 = find_inferior_ptid (ecs->ptid);
4929 struct regcache *child_regcache;
4930 CORE_ADDR parent_pc;
4932 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4933 indicating that the displaced stepping of syscall instruction
4934 has been done. Perform cleanup for parent process here. Note
4935 that this operation also cleans up the child process for vfork,
4936 because their pages are shared. */
4937 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
4938 /* Start a new step-over in another thread if there's one
4942 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4944 /* Restore scratch pad for child process. */
4945 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4948 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4949 the child's PC is also within the scratchpad. Set the child's PC
4950 to the parent's PC value, which has already been fixed up.
4951 FIXME: we use the parent's aspace here, although we're touching
4952 the child, because the child hasn't been added to the inferior
4953 list yet at this point. */
4956 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4958 parent_inf->aspace);
4959 /* Read PC value of parent process. */
4960 parent_pc = regcache_read_pc (regcache);
4962 if (debug_displaced)
4963 fprintf_unfiltered (gdb_stdlog,
4964 "displaced: write child pc from %s to %s\n",
4966 regcache_read_pc (child_regcache)),
4967 paddress (gdbarch, parent_pc));
4969 regcache_write_pc (child_regcache, parent_pc);
4973 if (!ptid_equal (ecs->ptid, inferior_ptid))
4974 context_switch (ecs->ptid);
4976 /* Immediately detach breakpoints from the child before there's
4977 any chance of letting the user delete breakpoints from the
4978 breakpoint lists. If we don't do this early, it's easy to
4979 leave left over traps in the child, vis: "break foo; catch
4980 fork; c; <fork>; del; c; <child calls foo>". We only follow
4981 the fork on the last `continue', and by that time the
4982 breakpoint at "foo" is long gone from the breakpoint table.
4983 If we vforked, then we don't need to unpatch here, since both
4984 parent and child are sharing the same memory pages; we'll
4985 need to unpatch at follow/detach time instead to be certain
4986 that new breakpoints added between catchpoint hit time and
4987 vfork follow are detached. */
4988 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4990 /* This won't actually modify the breakpoint list, but will
4991 physically remove the breakpoints from the child. */
4992 detach_breakpoints (ecs->ws.value.related_pid);
4995 delete_just_stopped_threads_single_step_breakpoints ();
4997 /* In case the event is caught by a catchpoint, remember that
4998 the event is to be followed at the next resume of the thread,
4999 and not immediately. */
5000 ecs->event_thread->pending_follow = ecs->ws;
5002 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5004 ecs->event_thread->control.stop_bpstat
5005 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5006 stop_pc, ecs->ptid, &ecs->ws);
5008 /* If no catchpoint triggered for this, then keep going. Note
5009 that we're interested in knowing the bpstat actually causes a
5010 stop, not just if it may explain the signal. Software
5011 watchpoints, for example, always appear in the bpstat. */
5012 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5018 = (follow_fork_mode_string == follow_fork_mode_child);
5020 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5022 should_resume = follow_fork ();
5025 child = ecs->ws.value.related_pid;
5027 /* In non-stop mode, also resume the other branch. */
5028 if (!detach_fork && (non_stop
5029 || (sched_multi && target_is_non_stop_p ())))
5032 switch_to_thread (parent);
5034 switch_to_thread (child);
5036 ecs->event_thread = inferior_thread ();
5037 ecs->ptid = inferior_ptid;
5042 switch_to_thread (child);
5044 switch_to_thread (parent);
5046 ecs->event_thread = inferior_thread ();
5047 ecs->ptid = inferior_ptid;
5055 process_event_stop_test (ecs);
5058 case TARGET_WAITKIND_VFORK_DONE:
5059 /* Done with the shared memory region. Re-insert breakpoints in
5060 the parent, and keep going. */
5063 fprintf_unfiltered (gdb_stdlog,
5064 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5066 if (!ptid_equal (ecs->ptid, inferior_ptid))
5067 context_switch (ecs->ptid);
5069 current_inferior ()->waiting_for_vfork_done = 0;
5070 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5071 /* This also takes care of reinserting breakpoints in the
5072 previously locked inferior. */
5076 case TARGET_WAITKIND_EXECD:
5078 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5080 if (!ptid_equal (ecs->ptid, inferior_ptid))
5081 context_switch (ecs->ptid);
5083 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5085 /* Do whatever is necessary to the parent branch of the vfork. */
5086 handle_vfork_child_exec_or_exit (1);
5088 /* This causes the eventpoints and symbol table to be reset.
5089 Must do this now, before trying to determine whether to
5091 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5093 /* In follow_exec we may have deleted the original thread and
5094 created a new one. Make sure that the event thread is the
5095 execd thread for that case (this is a nop otherwise). */
5096 ecs->event_thread = inferior_thread ();
5098 ecs->event_thread->control.stop_bpstat
5099 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5100 stop_pc, ecs->ptid, &ecs->ws);
5102 /* Note that this may be referenced from inside
5103 bpstat_stop_status above, through inferior_has_execd. */
5104 xfree (ecs->ws.value.execd_pathname);
5105 ecs->ws.value.execd_pathname = NULL;
5107 /* If no catchpoint triggered for this, then keep going. */
5108 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5110 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5114 process_event_stop_test (ecs);
5117 /* Be careful not to try to gather much state about a thread
5118 that's in a syscall. It's frequently a losing proposition. */
5119 case TARGET_WAITKIND_SYSCALL_ENTRY:
5121 fprintf_unfiltered (gdb_stdlog,
5122 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5123 /* Getting the current syscall number. */
5124 if (handle_syscall_event (ecs) == 0)
5125 process_event_stop_test (ecs);
5128 /* Before examining the threads further, step this thread to
5129 get it entirely out of the syscall. (We get notice of the
5130 event when the thread is just on the verge of exiting a
5131 syscall. Stepping one instruction seems to get it back
5133 case TARGET_WAITKIND_SYSCALL_RETURN:
5135 fprintf_unfiltered (gdb_stdlog,
5136 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5137 if (handle_syscall_event (ecs) == 0)
5138 process_event_stop_test (ecs);
5141 case TARGET_WAITKIND_STOPPED:
5143 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5144 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5145 handle_signal_stop (ecs);
5148 case TARGET_WAITKIND_NO_HISTORY:
5150 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5151 /* Reverse execution: target ran out of history info. */
5153 /* Switch to the stopped thread. */
5154 if (!ptid_equal (ecs->ptid, inferior_ptid))
5155 context_switch (ecs->ptid);
5157 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5159 delete_just_stopped_threads_single_step_breakpoints ();
5160 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5161 observer_notify_no_history ();
5167 /* A wrapper around handle_inferior_event_1, which also makes sure
5168 that all temporary struct value objects that were created during
5169 the handling of the event get deleted at the end. */
5172 handle_inferior_event (struct execution_control_state *ecs)
5174 struct value *mark = value_mark ();
5176 handle_inferior_event_1 (ecs);
5177 /* Purge all temporary values created during the event handling,
5178 as it could be a long time before we return to the command level
5179 where such values would otherwise be purged. */
5180 value_free_to_mark (mark);
5183 /* Restart threads back to what they were trying to do back when we
5184 paused them for an in-line step-over. The EVENT_THREAD thread is
5188 restart_threads (struct thread_info *event_thread)
5190 struct thread_info *tp;
5191 struct thread_info *step_over = NULL;
5193 /* In case the instruction just stepped spawned a new thread. */
5194 update_thread_list ();
5196 ALL_NON_EXITED_THREADS (tp)
5198 if (tp == event_thread)
5201 fprintf_unfiltered (gdb_stdlog,
5202 "infrun: restart threads: "
5203 "[%s] is event thread\n",
5204 target_pid_to_str (tp->ptid));
5208 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5211 fprintf_unfiltered (gdb_stdlog,
5212 "infrun: restart threads: "
5213 "[%s] not meant to be running\n",
5214 target_pid_to_str (tp->ptid));
5221 fprintf_unfiltered (gdb_stdlog,
5222 "infrun: restart threads: [%s] resumed\n",
5223 target_pid_to_str (tp->ptid));
5224 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5228 if (thread_is_in_step_over_chain (tp))
5231 fprintf_unfiltered (gdb_stdlog,
5232 "infrun: restart threads: "
5233 "[%s] needs step-over\n",
5234 target_pid_to_str (tp->ptid));
5235 gdb_assert (!tp->resumed);
5240 if (tp->suspend.waitstatus_pending_p)
5243 fprintf_unfiltered (gdb_stdlog,
5244 "infrun: restart threads: "
5245 "[%s] has pending status\n",
5246 target_pid_to_str (tp->ptid));
5251 /* If some thread needs to start a step-over at this point, it
5252 should still be in the step-over queue, and thus skipped
5254 if (thread_still_needs_step_over (tp))
5256 internal_error (__FILE__, __LINE__,
5257 "thread [%s] needs a step-over, but not in "
5258 "step-over queue\n",
5259 target_pid_to_str (tp->ptid));
5262 if (currently_stepping (tp))
5265 fprintf_unfiltered (gdb_stdlog,
5266 "infrun: restart threads: [%s] was stepping\n",
5267 target_pid_to_str (tp->ptid));
5268 keep_going_stepped_thread (tp);
5272 struct execution_control_state ecss;
5273 struct execution_control_state *ecs = &ecss;
5276 fprintf_unfiltered (gdb_stdlog,
5277 "infrun: restart threads: [%s] continuing\n",
5278 target_pid_to_str (tp->ptid));
5279 reset_ecs (ecs, tp);
5280 switch_to_thread (tp->ptid);
5281 keep_going_pass_signal (ecs);
5286 /* Callback for iterate_over_threads. Find a resumed thread that has
5287 a pending waitstatus. */
5290 resumed_thread_with_pending_status (struct thread_info *tp,
5294 && tp->suspend.waitstatus_pending_p);
5297 /* Called when we get an event that may finish an in-line or
5298 out-of-line (displaced stepping) step-over started previously.
5299 Return true if the event is processed and we should go back to the
5300 event loop; false if the caller should continue processing the
5304 finish_step_over (struct execution_control_state *ecs)
5306 int had_step_over_info;
5308 displaced_step_fixup (ecs->ptid,
5309 ecs->event_thread->suspend.stop_signal);
5311 had_step_over_info = step_over_info_valid_p ();
5313 if (had_step_over_info)
5315 /* If we're stepping over a breakpoint with all threads locked,
5316 then only the thread that was stepped should be reporting
5318 gdb_assert (ecs->event_thread->control.trap_expected);
5320 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5321 clear_step_over_info ();
5324 if (!target_is_non_stop_p ())
5327 /* Start a new step-over in another thread if there's one that
5331 /* If we were stepping over a breakpoint before, and haven't started
5332 a new in-line step-over sequence, then restart all other threads
5333 (except the event thread). We can't do this in all-stop, as then
5334 e.g., we wouldn't be able to issue any other remote packet until
5335 these other threads stop. */
5336 if (had_step_over_info && !step_over_info_valid_p ())
5338 struct thread_info *pending;
5340 /* If we only have threads with pending statuses, the restart
5341 below won't restart any thread and so nothing re-inserts the
5342 breakpoint we just stepped over. But we need it inserted
5343 when we later process the pending events, otherwise if
5344 another thread has a pending event for this breakpoint too,
5345 we'd discard its event (because the breakpoint that
5346 originally caused the event was no longer inserted). */
5347 context_switch (ecs->ptid);
5348 insert_breakpoints ();
5350 restart_threads (ecs->event_thread);
5352 /* If we have events pending, go through handle_inferior_event
5353 again, picking up a pending event at random. This avoids
5354 thread starvation. */
5356 /* But not if we just stepped over a watchpoint in order to let
5357 the instruction execute so we can evaluate its expression.
5358 The set of watchpoints that triggered is recorded in the
5359 breakpoint objects themselves (see bp->watchpoint_triggered).
5360 If we processed another event first, that other event could
5361 clobber this info. */
5362 if (ecs->event_thread->stepping_over_watchpoint)
5365 pending = iterate_over_threads (resumed_thread_with_pending_status,
5367 if (pending != NULL)
5369 struct thread_info *tp = ecs->event_thread;
5370 struct regcache *regcache;
5374 fprintf_unfiltered (gdb_stdlog,
5375 "infrun: found resumed threads with "
5376 "pending events, saving status\n");
5379 gdb_assert (pending != tp);
5381 /* Record the event thread's event for later. */
5382 save_waitstatus (tp, &ecs->ws);
5383 /* This was cleared early, by handle_inferior_event. Set it
5384 so this pending event is considered by
5388 gdb_assert (!tp->executing);
5390 regcache = get_thread_regcache (tp->ptid);
5391 tp->suspend.stop_pc = regcache_read_pc (regcache);
5395 fprintf_unfiltered (gdb_stdlog,
5396 "infrun: saved stop_pc=%s for %s "
5397 "(currently_stepping=%d)\n",
5398 paddress (target_gdbarch (),
5399 tp->suspend.stop_pc),
5400 target_pid_to_str (tp->ptid),
5401 currently_stepping (tp));
5404 /* This in-line step-over finished; clear this so we won't
5405 start a new one. This is what handle_signal_stop would
5406 do, if we returned false. */
5407 tp->stepping_over_breakpoint = 0;
5409 /* Wake up the event loop again. */
5410 mark_async_event_handler (infrun_async_inferior_event_token);
5412 prepare_to_wait (ecs);
5420 /* Come here when the program has stopped with a signal. */
5423 handle_signal_stop (struct execution_control_state *ecs)
5425 struct frame_info *frame;
5426 struct gdbarch *gdbarch;
5427 int stopped_by_watchpoint;
5428 enum stop_kind stop_soon;
5431 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5433 /* Do we need to clean up the state of a thread that has
5434 completed a displaced single-step? (Doing so usually affects
5435 the PC, so do it here, before we set stop_pc.) */
5436 if (finish_step_over (ecs))
5439 /* If we either finished a single-step or hit a breakpoint, but
5440 the user wanted this thread to be stopped, pretend we got a
5441 SIG0 (generic unsignaled stop). */
5442 if (ecs->event_thread->stop_requested
5443 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5444 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5446 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5450 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5451 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5452 struct cleanup *old_chain = save_inferior_ptid ();
5454 inferior_ptid = ecs->ptid;
5456 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5457 paddress (gdbarch, stop_pc));
5458 if (target_stopped_by_watchpoint ())
5462 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5464 if (target_stopped_data_address (¤t_target, &addr))
5465 fprintf_unfiltered (gdb_stdlog,
5466 "infrun: stopped data address = %s\n",
5467 paddress (gdbarch, addr));
5469 fprintf_unfiltered (gdb_stdlog,
5470 "infrun: (no data address available)\n");
5473 do_cleanups (old_chain);
5476 /* This is originated from start_remote(), start_inferior() and
5477 shared libraries hook functions. */
5478 stop_soon = get_inferior_stop_soon (ecs->ptid);
5479 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5481 if (!ptid_equal (ecs->ptid, inferior_ptid))
5482 context_switch (ecs->ptid);
5484 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5485 stop_print_frame = 1;
5490 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5493 if (!ptid_equal (ecs->ptid, inferior_ptid))
5494 context_switch (ecs->ptid);
5496 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5497 stop_print_frame = 0;
5502 /* This originates from attach_command(). We need to overwrite
5503 the stop_signal here, because some kernels don't ignore a
5504 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5505 See more comments in inferior.h. On the other hand, if we
5506 get a non-SIGSTOP, report it to the user - assume the backend
5507 will handle the SIGSTOP if it should show up later.
5509 Also consider that the attach is complete when we see a
5510 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5511 target extended-remote report it instead of a SIGSTOP
5512 (e.g. gdbserver). We already rely on SIGTRAP being our
5513 signal, so this is no exception.
5515 Also consider that the attach is complete when we see a
5516 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5517 the target to stop all threads of the inferior, in case the
5518 low level attach operation doesn't stop them implicitly. If
5519 they weren't stopped implicitly, then the stub will report a
5520 GDB_SIGNAL_0, meaning: stopped for no particular reason
5521 other than GDB's request. */
5522 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5523 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5524 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5525 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5527 stop_print_frame = 1;
5529 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5533 /* See if something interesting happened to the non-current thread. If
5534 so, then switch to that thread. */
5535 if (!ptid_equal (ecs->ptid, inferior_ptid))
5538 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5540 context_switch (ecs->ptid);
5542 if (deprecated_context_hook)
5543 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
5546 /* At this point, get hold of the now-current thread's frame. */
5547 frame = get_current_frame ();
5548 gdbarch = get_frame_arch (frame);
5550 /* Pull the single step breakpoints out of the target. */
5551 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5553 struct regcache *regcache;
5554 struct address_space *aspace;
5557 regcache = get_thread_regcache (ecs->ptid);
5558 aspace = get_regcache_aspace (regcache);
5559 pc = regcache_read_pc (regcache);
5561 /* However, before doing so, if this single-step breakpoint was
5562 actually for another thread, set this thread up for moving
5564 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5567 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5571 fprintf_unfiltered (gdb_stdlog,
5572 "infrun: [%s] hit another thread's "
5573 "single-step breakpoint\n",
5574 target_pid_to_str (ecs->ptid));
5576 ecs->hit_singlestep_breakpoint = 1;
5583 fprintf_unfiltered (gdb_stdlog,
5584 "infrun: [%s] hit its "
5585 "single-step breakpoint\n",
5586 target_pid_to_str (ecs->ptid));
5590 delete_just_stopped_threads_single_step_breakpoints ();
5592 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5593 && ecs->event_thread->control.trap_expected
5594 && ecs->event_thread->stepping_over_watchpoint)
5595 stopped_by_watchpoint = 0;
5597 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5599 /* If necessary, step over this watchpoint. We'll be back to display
5601 if (stopped_by_watchpoint
5602 && (target_have_steppable_watchpoint
5603 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5605 /* At this point, we are stopped at an instruction which has
5606 attempted to write to a piece of memory under control of
5607 a watchpoint. The instruction hasn't actually executed
5608 yet. If we were to evaluate the watchpoint expression
5609 now, we would get the old value, and therefore no change
5610 would seem to have occurred.
5612 In order to make watchpoints work `right', we really need
5613 to complete the memory write, and then evaluate the
5614 watchpoint expression. We do this by single-stepping the
5617 It may not be necessary to disable the watchpoint to step over
5618 it. For example, the PA can (with some kernel cooperation)
5619 single step over a watchpoint without disabling the watchpoint.
5621 It is far more common to need to disable a watchpoint to step
5622 the inferior over it. If we have non-steppable watchpoints,
5623 we must disable the current watchpoint; it's simplest to
5624 disable all watchpoints.
5626 Any breakpoint at PC must also be stepped over -- if there's
5627 one, it will have already triggered before the watchpoint
5628 triggered, and we either already reported it to the user, or
5629 it didn't cause a stop and we called keep_going. In either
5630 case, if there was a breakpoint at PC, we must be trying to
5632 ecs->event_thread->stepping_over_watchpoint = 1;
5637 ecs->event_thread->stepping_over_breakpoint = 0;
5638 ecs->event_thread->stepping_over_watchpoint = 0;
5639 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5640 ecs->event_thread->control.stop_step = 0;
5641 stop_print_frame = 1;
5642 stopped_by_random_signal = 0;
5644 /* Hide inlined functions starting here, unless we just performed stepi or
5645 nexti. After stepi and nexti, always show the innermost frame (not any
5646 inline function call sites). */
5647 if (ecs->event_thread->control.step_range_end != 1)
5649 struct address_space *aspace =
5650 get_regcache_aspace (get_thread_regcache (ecs->ptid));
5652 /* skip_inline_frames is expensive, so we avoid it if we can
5653 determine that the address is one where functions cannot have
5654 been inlined. This improves performance with inferiors that
5655 load a lot of shared libraries, because the solib event
5656 breakpoint is defined as the address of a function (i.e. not
5657 inline). Note that we have to check the previous PC as well
5658 as the current one to catch cases when we have just
5659 single-stepped off a breakpoint prior to reinstating it.
5660 Note that we're assuming that the code we single-step to is
5661 not inline, but that's not definitive: there's nothing
5662 preventing the event breakpoint function from containing
5663 inlined code, and the single-step ending up there. If the
5664 user had set a breakpoint on that inlined code, the missing
5665 skip_inline_frames call would break things. Fortunately
5666 that's an extremely unlikely scenario. */
5667 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5668 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5669 && ecs->event_thread->control.trap_expected
5670 && pc_at_non_inline_function (aspace,
5671 ecs->event_thread->prev_pc,
5674 skip_inline_frames (ecs->ptid);
5676 /* Re-fetch current thread's frame in case that invalidated
5678 frame = get_current_frame ();
5679 gdbarch = get_frame_arch (frame);
5683 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5684 && ecs->event_thread->control.trap_expected
5685 && gdbarch_single_step_through_delay_p (gdbarch)
5686 && currently_stepping (ecs->event_thread))
5688 /* We're trying to step off a breakpoint. Turns out that we're
5689 also on an instruction that needs to be stepped multiple
5690 times before it's been fully executing. E.g., architectures
5691 with a delay slot. It needs to be stepped twice, once for
5692 the instruction and once for the delay slot. */
5693 int step_through_delay
5694 = gdbarch_single_step_through_delay (gdbarch, frame);
5696 if (debug_infrun && step_through_delay)
5697 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5698 if (ecs->event_thread->control.step_range_end == 0
5699 && step_through_delay)
5701 /* The user issued a continue when stopped at a breakpoint.
5702 Set up for another trap and get out of here. */
5703 ecs->event_thread->stepping_over_breakpoint = 1;
5707 else if (step_through_delay)
5709 /* The user issued a step when stopped at a breakpoint.
5710 Maybe we should stop, maybe we should not - the delay
5711 slot *might* correspond to a line of source. In any
5712 case, don't decide that here, just set
5713 ecs->stepping_over_breakpoint, making sure we
5714 single-step again before breakpoints are re-inserted. */
5715 ecs->event_thread->stepping_over_breakpoint = 1;
5719 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5720 handles this event. */
5721 ecs->event_thread->control.stop_bpstat
5722 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5723 stop_pc, ecs->ptid, &ecs->ws);
5725 /* Following in case break condition called a
5727 stop_print_frame = 1;
5729 /* This is where we handle "moribund" watchpoints. Unlike
5730 software breakpoints traps, hardware watchpoint traps are
5731 always distinguishable from random traps. If no high-level
5732 watchpoint is associated with the reported stop data address
5733 anymore, then the bpstat does not explain the signal ---
5734 simply make sure to ignore it if `stopped_by_watchpoint' is
5738 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5739 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5741 && stopped_by_watchpoint)
5742 fprintf_unfiltered (gdb_stdlog,
5743 "infrun: no user watchpoint explains "
5744 "watchpoint SIGTRAP, ignoring\n");
5746 /* NOTE: cagney/2003-03-29: These checks for a random signal
5747 at one stage in the past included checks for an inferior
5748 function call's call dummy's return breakpoint. The original
5749 comment, that went with the test, read:
5751 ``End of a stack dummy. Some systems (e.g. Sony news) give
5752 another signal besides SIGTRAP, so check here as well as
5755 If someone ever tries to get call dummys on a
5756 non-executable stack to work (where the target would stop
5757 with something like a SIGSEGV), then those tests might need
5758 to be re-instated. Given, however, that the tests were only
5759 enabled when momentary breakpoints were not being used, I
5760 suspect that it won't be the case.
5762 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5763 be necessary for call dummies on a non-executable stack on
5766 /* See if the breakpoints module can explain the signal. */
5768 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5769 ecs->event_thread->suspend.stop_signal);
5771 /* Maybe this was a trap for a software breakpoint that has since
5773 if (random_signal && target_stopped_by_sw_breakpoint ())
5775 if (program_breakpoint_here_p (gdbarch, stop_pc))
5777 struct regcache *regcache;
5780 /* Re-adjust PC to what the program would see if GDB was not
5782 regcache = get_thread_regcache (ecs->event_thread->ptid);
5783 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5786 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
5788 if (record_full_is_used ())
5789 record_full_gdb_operation_disable_set ();
5791 regcache_write_pc (regcache, stop_pc + decr_pc);
5793 do_cleanups (old_cleanups);
5798 /* A delayed software breakpoint event. Ignore the trap. */
5800 fprintf_unfiltered (gdb_stdlog,
5801 "infrun: delayed software breakpoint "
5802 "trap, ignoring\n");
5807 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5808 has since been removed. */
5809 if (random_signal && target_stopped_by_hw_breakpoint ())
5811 /* A delayed hardware breakpoint event. Ignore the trap. */
5813 fprintf_unfiltered (gdb_stdlog,
5814 "infrun: delayed hardware breakpoint/watchpoint "
5815 "trap, ignoring\n");
5819 /* If not, perhaps stepping/nexting can. */
5821 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5822 && currently_stepping (ecs->event_thread));
5824 /* Perhaps the thread hit a single-step breakpoint of _another_
5825 thread. Single-step breakpoints are transparent to the
5826 breakpoints module. */
5828 random_signal = !ecs->hit_singlestep_breakpoint;
5830 /* No? Perhaps we got a moribund watchpoint. */
5832 random_signal = !stopped_by_watchpoint;
5834 /* For the program's own signals, act according to
5835 the signal handling tables. */
5839 /* Signal not for debugging purposes. */
5840 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5841 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5844 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5845 gdb_signal_to_symbol_string (stop_signal));
5847 stopped_by_random_signal = 1;
5849 /* Always stop on signals if we're either just gaining control
5850 of the program, or the user explicitly requested this thread
5851 to remain stopped. */
5852 if (stop_soon != NO_STOP_QUIETLY
5853 || ecs->event_thread->stop_requested
5855 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5861 /* Notify observers the signal has "handle print" set. Note we
5862 returned early above if stopping; normal_stop handles the
5863 printing in that case. */
5864 if (signal_print[ecs->event_thread->suspend.stop_signal])
5866 /* The signal table tells us to print about this signal. */
5867 target_terminal_ours_for_output ();
5868 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
5869 target_terminal_inferior ();
5872 /* Clear the signal if it should not be passed. */
5873 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5874 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5876 if (ecs->event_thread->prev_pc == stop_pc
5877 && ecs->event_thread->control.trap_expected
5878 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5882 /* We were just starting a new sequence, attempting to
5883 single-step off of a breakpoint and expecting a SIGTRAP.
5884 Instead this signal arrives. This signal will take us out
5885 of the stepping range so GDB needs to remember to, when
5886 the signal handler returns, resume stepping off that
5888 /* To simplify things, "continue" is forced to use the same
5889 code paths as single-step - set a breakpoint at the
5890 signal return address and then, once hit, step off that
5893 fprintf_unfiltered (gdb_stdlog,
5894 "infrun: signal arrived while stepping over "
5897 was_in_line = step_over_info_valid_p ();
5898 clear_step_over_info ();
5899 insert_hp_step_resume_breakpoint_at_frame (frame);
5900 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5901 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5902 ecs->event_thread->control.trap_expected = 0;
5904 if (target_is_non_stop_p ())
5906 /* Either "set non-stop" is "on", or the target is
5907 always in non-stop mode. In this case, we have a bit
5908 more work to do. Resume the current thread, and if
5909 we had paused all threads, restart them while the
5910 signal handler runs. */
5915 restart_threads (ecs->event_thread);
5917 else if (debug_infrun)
5919 fprintf_unfiltered (gdb_stdlog,
5920 "infrun: no need to restart threads\n");
5925 /* If we were nexting/stepping some other thread, switch to
5926 it, so that we don't continue it, losing control. */
5927 if (!switch_back_to_stepped_thread (ecs))
5932 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5933 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
5934 || ecs->event_thread->control.step_range_end == 1)
5935 && frame_id_eq (get_stack_frame_id (frame),
5936 ecs->event_thread->control.step_stack_frame_id)
5937 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5939 /* The inferior is about to take a signal that will take it
5940 out of the single step range. Set a breakpoint at the
5941 current PC (which is presumably where the signal handler
5942 will eventually return) and then allow the inferior to
5945 Note that this is only needed for a signal delivered
5946 while in the single-step range. Nested signals aren't a
5947 problem as they eventually all return. */
5949 fprintf_unfiltered (gdb_stdlog,
5950 "infrun: signal may take us out of "
5951 "single-step range\n");
5953 clear_step_over_info ();
5954 insert_hp_step_resume_breakpoint_at_frame (frame);
5955 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5956 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5957 ecs->event_thread->control.trap_expected = 0;
5962 /* Note: step_resume_breakpoint may be non-NULL. This occures
5963 when either there's a nested signal, or when there's a
5964 pending signal enabled just as the signal handler returns
5965 (leaving the inferior at the step-resume-breakpoint without
5966 actually executing it). Either way continue until the
5967 breakpoint is really hit. */
5969 if (!switch_back_to_stepped_thread (ecs))
5972 fprintf_unfiltered (gdb_stdlog,
5973 "infrun: random signal, keep going\n");
5980 process_event_stop_test (ecs);
5983 /* Come here when we've got some debug event / signal we can explain
5984 (IOW, not a random signal), and test whether it should cause a
5985 stop, or whether we should resume the inferior (transparently).
5986 E.g., could be a breakpoint whose condition evaluates false; we
5987 could be still stepping within the line; etc. */
5990 process_event_stop_test (struct execution_control_state *ecs)
5992 struct symtab_and_line stop_pc_sal;
5993 struct frame_info *frame;
5994 struct gdbarch *gdbarch;
5995 CORE_ADDR jmp_buf_pc;
5996 struct bpstat_what what;
5998 /* Handle cases caused by hitting a breakpoint. */
6000 frame = get_current_frame ();
6001 gdbarch = get_frame_arch (frame);
6003 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6005 if (what.call_dummy)
6007 stop_stack_dummy = what.call_dummy;
6010 /* A few breakpoint types have callbacks associated (e.g.,
6011 bp_jit_event). Run them now. */
6012 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6014 /* If we hit an internal event that triggers symbol changes, the
6015 current frame will be invalidated within bpstat_what (e.g., if we
6016 hit an internal solib event). Re-fetch it. */
6017 frame = get_current_frame ();
6018 gdbarch = get_frame_arch (frame);
6020 switch (what.main_action)
6022 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6023 /* If we hit the breakpoint at longjmp while stepping, we
6024 install a momentary breakpoint at the target of the
6028 fprintf_unfiltered (gdb_stdlog,
6029 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6031 ecs->event_thread->stepping_over_breakpoint = 1;
6033 if (what.is_longjmp)
6035 struct value *arg_value;
6037 /* If we set the longjmp breakpoint via a SystemTap probe,
6038 then use it to extract the arguments. The destination PC
6039 is the third argument to the probe. */
6040 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6043 jmp_buf_pc = value_as_address (arg_value);
6044 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6046 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6047 || !gdbarch_get_longjmp_target (gdbarch,
6048 frame, &jmp_buf_pc))
6051 fprintf_unfiltered (gdb_stdlog,
6052 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6053 "(!gdbarch_get_longjmp_target)\n");
6058 /* Insert a breakpoint at resume address. */
6059 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6062 check_exception_resume (ecs, frame);
6066 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6068 struct frame_info *init_frame;
6070 /* There are several cases to consider.
6072 1. The initiating frame no longer exists. In this case we
6073 must stop, because the exception or longjmp has gone too
6076 2. The initiating frame exists, and is the same as the
6077 current frame. We stop, because the exception or longjmp
6080 3. The initiating frame exists and is different from the
6081 current frame. This means the exception or longjmp has
6082 been caught beneath the initiating frame, so keep going.
6084 4. longjmp breakpoint has been placed just to protect
6085 against stale dummy frames and user is not interested in
6086 stopping around longjmps. */
6089 fprintf_unfiltered (gdb_stdlog,
6090 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6092 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6094 delete_exception_resume_breakpoint (ecs->event_thread);
6096 if (what.is_longjmp)
6098 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6100 if (!frame_id_p (ecs->event_thread->initiating_frame))
6108 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6112 struct frame_id current_id
6113 = get_frame_id (get_current_frame ());
6114 if (frame_id_eq (current_id,
6115 ecs->event_thread->initiating_frame))
6117 /* Case 2. Fall through. */
6127 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6129 delete_step_resume_breakpoint (ecs->event_thread);
6131 end_stepping_range (ecs);
6135 case BPSTAT_WHAT_SINGLE:
6137 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6138 ecs->event_thread->stepping_over_breakpoint = 1;
6139 /* Still need to check other stuff, at least the case where we
6140 are stepping and step out of the right range. */
6143 case BPSTAT_WHAT_STEP_RESUME:
6145 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6147 delete_step_resume_breakpoint (ecs->event_thread);
6148 if (ecs->event_thread->control.proceed_to_finish
6149 && execution_direction == EXEC_REVERSE)
6151 struct thread_info *tp = ecs->event_thread;
6153 /* We are finishing a function in reverse, and just hit the
6154 step-resume breakpoint at the start address of the
6155 function, and we're almost there -- just need to back up
6156 by one more single-step, which should take us back to the
6158 tp->control.step_range_start = tp->control.step_range_end = 1;
6162 fill_in_stop_func (gdbarch, ecs);
6163 if (stop_pc == ecs->stop_func_start
6164 && execution_direction == EXEC_REVERSE)
6166 /* We are stepping over a function call in reverse, and just
6167 hit the step-resume breakpoint at the start address of
6168 the function. Go back to single-stepping, which should
6169 take us back to the function call. */
6170 ecs->event_thread->stepping_over_breakpoint = 1;
6176 case BPSTAT_WHAT_STOP_NOISY:
6178 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6179 stop_print_frame = 1;
6181 /* Assume the thread stopped for a breapoint. We'll still check
6182 whether a/the breakpoint is there when the thread is next
6184 ecs->event_thread->stepping_over_breakpoint = 1;
6189 case BPSTAT_WHAT_STOP_SILENT:
6191 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6192 stop_print_frame = 0;
6194 /* Assume the thread stopped for a breapoint. We'll still check
6195 whether a/the breakpoint is there when the thread is next
6197 ecs->event_thread->stepping_over_breakpoint = 1;
6201 case BPSTAT_WHAT_HP_STEP_RESUME:
6203 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6205 delete_step_resume_breakpoint (ecs->event_thread);
6206 if (ecs->event_thread->step_after_step_resume_breakpoint)
6208 /* Back when the step-resume breakpoint was inserted, we
6209 were trying to single-step off a breakpoint. Go back to
6211 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6212 ecs->event_thread->stepping_over_breakpoint = 1;
6218 case BPSTAT_WHAT_KEEP_CHECKING:
6222 /* If we stepped a permanent breakpoint and we had a high priority
6223 step-resume breakpoint for the address we stepped, but we didn't
6224 hit it, then we must have stepped into the signal handler. The
6225 step-resume was only necessary to catch the case of _not_
6226 stepping into the handler, so delete it, and fall through to
6227 checking whether the step finished. */
6228 if (ecs->event_thread->stepped_breakpoint)
6230 struct breakpoint *sr_bp
6231 = ecs->event_thread->control.step_resume_breakpoint;
6234 && sr_bp->loc->permanent
6235 && sr_bp->type == bp_hp_step_resume
6236 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6239 fprintf_unfiltered (gdb_stdlog,
6240 "infrun: stepped permanent breakpoint, stopped in "
6242 delete_step_resume_breakpoint (ecs->event_thread);
6243 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6247 /* We come here if we hit a breakpoint but should not stop for it.
6248 Possibly we also were stepping and should stop for that. So fall
6249 through and test for stepping. But, if not stepping, do not
6252 /* In all-stop mode, if we're currently stepping but have stopped in
6253 some other thread, we need to switch back to the stepped thread. */
6254 if (switch_back_to_stepped_thread (ecs))
6257 if (ecs->event_thread->control.step_resume_breakpoint)
6260 fprintf_unfiltered (gdb_stdlog,
6261 "infrun: step-resume breakpoint is inserted\n");
6263 /* Having a step-resume breakpoint overrides anything
6264 else having to do with stepping commands until
6265 that breakpoint is reached. */
6270 if (ecs->event_thread->control.step_range_end == 0)
6273 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6274 /* Likewise if we aren't even stepping. */
6279 /* Re-fetch current thread's frame in case the code above caused
6280 the frame cache to be re-initialized, making our FRAME variable
6281 a dangling pointer. */
6282 frame = get_current_frame ();
6283 gdbarch = get_frame_arch (frame);
6284 fill_in_stop_func (gdbarch, ecs);
6286 /* If stepping through a line, keep going if still within it.
6288 Note that step_range_end is the address of the first instruction
6289 beyond the step range, and NOT the address of the last instruction
6292 Note also that during reverse execution, we may be stepping
6293 through a function epilogue and therefore must detect when
6294 the current-frame changes in the middle of a line. */
6296 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6297 && (execution_direction != EXEC_REVERSE
6298 || frame_id_eq (get_frame_id (frame),
6299 ecs->event_thread->control.step_frame_id)))
6303 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6304 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6305 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6307 /* Tentatively re-enable range stepping; `resume' disables it if
6308 necessary (e.g., if we're stepping over a breakpoint or we
6309 have software watchpoints). */
6310 ecs->event_thread->control.may_range_step = 1;
6312 /* When stepping backward, stop at beginning of line range
6313 (unless it's the function entry point, in which case
6314 keep going back to the call point). */
6315 if (stop_pc == ecs->event_thread->control.step_range_start
6316 && stop_pc != ecs->stop_func_start
6317 && execution_direction == EXEC_REVERSE)
6318 end_stepping_range (ecs);
6325 /* We stepped out of the stepping range. */
6327 /* If we are stepping at the source level and entered the runtime
6328 loader dynamic symbol resolution code...
6330 EXEC_FORWARD: we keep on single stepping until we exit the run
6331 time loader code and reach the callee's address.
6333 EXEC_REVERSE: we've already executed the callee (backward), and
6334 the runtime loader code is handled just like any other
6335 undebuggable function call. Now we need only keep stepping
6336 backward through the trampoline code, and that's handled further
6337 down, so there is nothing for us to do here. */
6339 if (execution_direction != EXEC_REVERSE
6340 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6341 && in_solib_dynsym_resolve_code (stop_pc))
6343 CORE_ADDR pc_after_resolver =
6344 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6347 fprintf_unfiltered (gdb_stdlog,
6348 "infrun: stepped into dynsym resolve code\n");
6350 if (pc_after_resolver)
6352 /* Set up a step-resume breakpoint at the address
6353 indicated by SKIP_SOLIB_RESOLVER. */
6354 struct symtab_and_line sr_sal;
6357 sr_sal.pc = pc_after_resolver;
6358 sr_sal.pspace = get_frame_program_space (frame);
6360 insert_step_resume_breakpoint_at_sal (gdbarch,
6361 sr_sal, null_frame_id);
6368 if (ecs->event_thread->control.step_range_end != 1
6369 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6370 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6371 && get_frame_type (frame) == SIGTRAMP_FRAME)
6374 fprintf_unfiltered (gdb_stdlog,
6375 "infrun: stepped into signal trampoline\n");
6376 /* The inferior, while doing a "step" or "next", has ended up in
6377 a signal trampoline (either by a signal being delivered or by
6378 the signal handler returning). Just single-step until the
6379 inferior leaves the trampoline (either by calling the handler
6385 /* If we're in the return path from a shared library trampoline,
6386 we want to proceed through the trampoline when stepping. */
6387 /* macro/2012-04-25: This needs to come before the subroutine
6388 call check below as on some targets return trampolines look
6389 like subroutine calls (MIPS16 return thunks). */
6390 if (gdbarch_in_solib_return_trampoline (gdbarch,
6391 stop_pc, ecs->stop_func_name)
6392 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6394 /* Determine where this trampoline returns. */
6395 CORE_ADDR real_stop_pc;
6397 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6400 fprintf_unfiltered (gdb_stdlog,
6401 "infrun: stepped into solib return tramp\n");
6403 /* Only proceed through if we know where it's going. */
6406 /* And put the step-breakpoint there and go until there. */
6407 struct symtab_and_line sr_sal;
6409 init_sal (&sr_sal); /* initialize to zeroes */
6410 sr_sal.pc = real_stop_pc;
6411 sr_sal.section = find_pc_overlay (sr_sal.pc);
6412 sr_sal.pspace = get_frame_program_space (frame);
6414 /* Do not specify what the fp should be when we stop since
6415 on some machines the prologue is where the new fp value
6417 insert_step_resume_breakpoint_at_sal (gdbarch,
6418 sr_sal, null_frame_id);
6420 /* Restart without fiddling with the step ranges or
6427 /* Check for subroutine calls. The check for the current frame
6428 equalling the step ID is not necessary - the check of the
6429 previous frame's ID is sufficient - but it is a common case and
6430 cheaper than checking the previous frame's ID.
6432 NOTE: frame_id_eq will never report two invalid frame IDs as
6433 being equal, so to get into this block, both the current and
6434 previous frame must have valid frame IDs. */
6435 /* The outer_frame_id check is a heuristic to detect stepping
6436 through startup code. If we step over an instruction which
6437 sets the stack pointer from an invalid value to a valid value,
6438 we may detect that as a subroutine call from the mythical
6439 "outermost" function. This could be fixed by marking
6440 outermost frames as !stack_p,code_p,special_p. Then the
6441 initial outermost frame, before sp was valid, would
6442 have code_addr == &_start. See the comment in frame_id_eq
6444 if (!frame_id_eq (get_stack_frame_id (frame),
6445 ecs->event_thread->control.step_stack_frame_id)
6446 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6447 ecs->event_thread->control.step_stack_frame_id)
6448 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6450 || (ecs->event_thread->control.step_start_function
6451 != find_pc_function (stop_pc)))))
6453 CORE_ADDR real_stop_pc;
6456 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6458 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6460 /* I presume that step_over_calls is only 0 when we're
6461 supposed to be stepping at the assembly language level
6462 ("stepi"). Just stop. */
6463 /* And this works the same backward as frontward. MVS */
6464 end_stepping_range (ecs);
6468 /* Reverse stepping through solib trampolines. */
6470 if (execution_direction == EXEC_REVERSE
6471 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6472 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6473 || (ecs->stop_func_start == 0
6474 && in_solib_dynsym_resolve_code (stop_pc))))
6476 /* Any solib trampoline code can be handled in reverse
6477 by simply continuing to single-step. We have already
6478 executed the solib function (backwards), and a few
6479 steps will take us back through the trampoline to the
6485 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6487 /* We're doing a "next".
6489 Normal (forward) execution: set a breakpoint at the
6490 callee's return address (the address at which the caller
6493 Reverse (backward) execution. set the step-resume
6494 breakpoint at the start of the function that we just
6495 stepped into (backwards), and continue to there. When we
6496 get there, we'll need to single-step back to the caller. */
6498 if (execution_direction == EXEC_REVERSE)
6500 /* If we're already at the start of the function, we've either
6501 just stepped backward into a single instruction function,
6502 or stepped back out of a signal handler to the first instruction
6503 of the function. Just keep going, which will single-step back
6505 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6507 struct symtab_and_line sr_sal;
6509 /* Normal function call return (static or dynamic). */
6511 sr_sal.pc = ecs->stop_func_start;
6512 sr_sal.pspace = get_frame_program_space (frame);
6513 insert_step_resume_breakpoint_at_sal (gdbarch,
6514 sr_sal, null_frame_id);
6518 insert_step_resume_breakpoint_at_caller (frame);
6524 /* If we are in a function call trampoline (a stub between the
6525 calling routine and the real function), locate the real
6526 function. That's what tells us (a) whether we want to step
6527 into it at all, and (b) what prologue we want to run to the
6528 end of, if we do step into it. */
6529 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6530 if (real_stop_pc == 0)
6531 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6532 if (real_stop_pc != 0)
6533 ecs->stop_func_start = real_stop_pc;
6535 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6537 struct symtab_and_line sr_sal;
6540 sr_sal.pc = ecs->stop_func_start;
6541 sr_sal.pspace = get_frame_program_space (frame);
6543 insert_step_resume_breakpoint_at_sal (gdbarch,
6544 sr_sal, null_frame_id);
6549 /* If we have line number information for the function we are
6550 thinking of stepping into and the function isn't on the skip
6553 If there are several symtabs at that PC (e.g. with include
6554 files), just want to know whether *any* of them have line
6555 numbers. find_pc_line handles this. */
6557 struct symtab_and_line tmp_sal;
6559 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6560 if (tmp_sal.line != 0
6561 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6564 if (execution_direction == EXEC_REVERSE)
6565 handle_step_into_function_backward (gdbarch, ecs);
6567 handle_step_into_function (gdbarch, ecs);
6572 /* If we have no line number and the step-stop-if-no-debug is
6573 set, we stop the step so that the user has a chance to switch
6574 in assembly mode. */
6575 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6576 && step_stop_if_no_debug)
6578 end_stepping_range (ecs);
6582 if (execution_direction == EXEC_REVERSE)
6584 /* If we're already at the start of the function, we've either just
6585 stepped backward into a single instruction function without line
6586 number info, or stepped back out of a signal handler to the first
6587 instruction of the function without line number info. Just keep
6588 going, which will single-step back to the caller. */
6589 if (ecs->stop_func_start != stop_pc)
6591 /* Set a breakpoint at callee's start address.
6592 From there we can step once and be back in the caller. */
6593 struct symtab_and_line sr_sal;
6596 sr_sal.pc = ecs->stop_func_start;
6597 sr_sal.pspace = get_frame_program_space (frame);
6598 insert_step_resume_breakpoint_at_sal (gdbarch,
6599 sr_sal, null_frame_id);
6603 /* Set a breakpoint at callee's return address (the address
6604 at which the caller will resume). */
6605 insert_step_resume_breakpoint_at_caller (frame);
6611 /* Reverse stepping through solib trampolines. */
6613 if (execution_direction == EXEC_REVERSE
6614 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6616 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6617 || (ecs->stop_func_start == 0
6618 && in_solib_dynsym_resolve_code (stop_pc)))
6620 /* Any solib trampoline code can be handled in reverse
6621 by simply continuing to single-step. We have already
6622 executed the solib function (backwards), and a few
6623 steps will take us back through the trampoline to the
6628 else if (in_solib_dynsym_resolve_code (stop_pc))
6630 /* Stepped backward into the solib dynsym resolver.
6631 Set a breakpoint at its start and continue, then
6632 one more step will take us out. */
6633 struct symtab_and_line sr_sal;
6636 sr_sal.pc = ecs->stop_func_start;
6637 sr_sal.pspace = get_frame_program_space (frame);
6638 insert_step_resume_breakpoint_at_sal (gdbarch,
6639 sr_sal, null_frame_id);
6645 stop_pc_sal = find_pc_line (stop_pc, 0);
6647 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6648 the trampoline processing logic, however, there are some trampolines
6649 that have no names, so we should do trampoline handling first. */
6650 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6651 && ecs->stop_func_name == NULL
6652 && stop_pc_sal.line == 0)
6655 fprintf_unfiltered (gdb_stdlog,
6656 "infrun: stepped into undebuggable function\n");
6658 /* The inferior just stepped into, or returned to, an
6659 undebuggable function (where there is no debugging information
6660 and no line number corresponding to the address where the
6661 inferior stopped). Since we want to skip this kind of code,
6662 we keep going until the inferior returns from this
6663 function - unless the user has asked us not to (via
6664 set step-mode) or we no longer know how to get back
6665 to the call site. */
6666 if (step_stop_if_no_debug
6667 || !frame_id_p (frame_unwind_caller_id (frame)))
6669 /* If we have no line number and the step-stop-if-no-debug
6670 is set, we stop the step so that the user has a chance to
6671 switch in assembly mode. */
6672 end_stepping_range (ecs);
6677 /* Set a breakpoint at callee's return address (the address
6678 at which the caller will resume). */
6679 insert_step_resume_breakpoint_at_caller (frame);
6685 if (ecs->event_thread->control.step_range_end == 1)
6687 /* It is stepi or nexti. We always want to stop stepping after
6690 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6691 end_stepping_range (ecs);
6695 if (stop_pc_sal.line == 0)
6697 /* We have no line number information. That means to stop
6698 stepping (does this always happen right after one instruction,
6699 when we do "s" in a function with no line numbers,
6700 or can this happen as a result of a return or longjmp?). */
6702 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6703 end_stepping_range (ecs);
6707 /* Look for "calls" to inlined functions, part one. If the inline
6708 frame machinery detected some skipped call sites, we have entered
6709 a new inline function. */
6711 if (frame_id_eq (get_frame_id (get_current_frame ()),
6712 ecs->event_thread->control.step_frame_id)
6713 && inline_skipped_frames (ecs->ptid))
6715 struct symtab_and_line call_sal;
6718 fprintf_unfiltered (gdb_stdlog,
6719 "infrun: stepped into inlined function\n");
6721 find_frame_sal (get_current_frame (), &call_sal);
6723 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6725 /* For "step", we're going to stop. But if the call site
6726 for this inlined function is on the same source line as
6727 we were previously stepping, go down into the function
6728 first. Otherwise stop at the call site. */
6730 if (call_sal.line == ecs->event_thread->current_line
6731 && call_sal.symtab == ecs->event_thread->current_symtab)
6732 step_into_inline_frame (ecs->ptid);
6734 end_stepping_range (ecs);
6739 /* For "next", we should stop at the call site if it is on a
6740 different source line. Otherwise continue through the
6741 inlined function. */
6742 if (call_sal.line == ecs->event_thread->current_line
6743 && call_sal.symtab == ecs->event_thread->current_symtab)
6746 end_stepping_range (ecs);
6751 /* Look for "calls" to inlined functions, part two. If we are still
6752 in the same real function we were stepping through, but we have
6753 to go further up to find the exact frame ID, we are stepping
6754 through a more inlined call beyond its call site. */
6756 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6757 && !frame_id_eq (get_frame_id (get_current_frame ()),
6758 ecs->event_thread->control.step_frame_id)
6759 && stepped_in_from (get_current_frame (),
6760 ecs->event_thread->control.step_frame_id))
6763 fprintf_unfiltered (gdb_stdlog,
6764 "infrun: stepping through inlined function\n");
6766 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6769 end_stepping_range (ecs);
6773 if ((stop_pc == stop_pc_sal.pc)
6774 && (ecs->event_thread->current_line != stop_pc_sal.line
6775 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6777 /* We are at the start of a different line. So stop. Note that
6778 we don't stop if we step into the middle of a different line.
6779 That is said to make things like for (;;) statements work
6782 fprintf_unfiltered (gdb_stdlog,
6783 "infrun: stepped to a different line\n");
6784 end_stepping_range (ecs);
6788 /* We aren't done stepping.
6790 Optimize by setting the stepping range to the line.
6791 (We might not be in the original line, but if we entered a
6792 new line in mid-statement, we continue stepping. This makes
6793 things like for(;;) statements work better.) */
6795 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6796 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6797 ecs->event_thread->control.may_range_step = 1;
6798 set_step_info (frame, stop_pc_sal);
6801 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6805 /* In all-stop mode, if we're currently stepping but have stopped in
6806 some other thread, we may need to switch back to the stepped
6807 thread. Returns true we set the inferior running, false if we left
6808 it stopped (and the event needs further processing). */
6811 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6813 if (!target_is_non_stop_p ())
6815 struct thread_info *tp;
6816 struct thread_info *stepping_thread;
6818 /* If any thread is blocked on some internal breakpoint, and we
6819 simply need to step over that breakpoint to get it going
6820 again, do that first. */
6822 /* However, if we see an event for the stepping thread, then we
6823 know all other threads have been moved past their breakpoints
6824 already. Let the caller check whether the step is finished,
6825 etc., before deciding to move it past a breakpoint. */
6826 if (ecs->event_thread->control.step_range_end != 0)
6829 /* Check if the current thread is blocked on an incomplete
6830 step-over, interrupted by a random signal. */
6831 if (ecs->event_thread->control.trap_expected
6832 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6836 fprintf_unfiltered (gdb_stdlog,
6837 "infrun: need to finish step-over of [%s]\n",
6838 target_pid_to_str (ecs->event_thread->ptid));
6844 /* Check if the current thread is blocked by a single-step
6845 breakpoint of another thread. */
6846 if (ecs->hit_singlestep_breakpoint)
6850 fprintf_unfiltered (gdb_stdlog,
6851 "infrun: need to step [%s] over single-step "
6853 target_pid_to_str (ecs->ptid));
6859 /* If this thread needs yet another step-over (e.g., stepping
6860 through a delay slot), do it first before moving on to
6862 if (thread_still_needs_step_over (ecs->event_thread))
6866 fprintf_unfiltered (gdb_stdlog,
6867 "infrun: thread [%s] still needs step-over\n",
6868 target_pid_to_str (ecs->event_thread->ptid));
6874 /* If scheduler locking applies even if not stepping, there's no
6875 need to walk over threads. Above we've checked whether the
6876 current thread is stepping. If some other thread not the
6877 event thread is stepping, then it must be that scheduler
6878 locking is not in effect. */
6879 if (schedlock_applies (ecs->event_thread))
6882 /* Otherwise, we no longer expect a trap in the current thread.
6883 Clear the trap_expected flag before switching back -- this is
6884 what keep_going does as well, if we call it. */
6885 ecs->event_thread->control.trap_expected = 0;
6887 /* Likewise, clear the signal if it should not be passed. */
6888 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6889 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6891 /* Do all pending step-overs before actually proceeding with
6893 if (start_step_over ())
6895 prepare_to_wait (ecs);
6899 /* Look for the stepping/nexting thread. */
6900 stepping_thread = NULL;
6902 ALL_NON_EXITED_THREADS (tp)
6904 /* Ignore threads of processes the caller is not
6907 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
6910 /* When stepping over a breakpoint, we lock all threads
6911 except the one that needs to move past the breakpoint.
6912 If a non-event thread has this set, the "incomplete
6913 step-over" check above should have caught it earlier. */
6914 if (tp->control.trap_expected)
6916 internal_error (__FILE__, __LINE__,
6917 "[%s] has inconsistent state: "
6918 "trap_expected=%d\n",
6919 target_pid_to_str (tp->ptid),
6920 tp->control.trap_expected);
6923 /* Did we find the stepping thread? */
6924 if (tp->control.step_range_end)
6926 /* Yep. There should only one though. */
6927 gdb_assert (stepping_thread == NULL);
6929 /* The event thread is handled at the top, before we
6931 gdb_assert (tp != ecs->event_thread);
6933 /* If some thread other than the event thread is
6934 stepping, then scheduler locking can't be in effect,
6935 otherwise we wouldn't have resumed the current event
6936 thread in the first place. */
6937 gdb_assert (!schedlock_applies (tp));
6939 stepping_thread = tp;
6943 if (stepping_thread != NULL)
6946 fprintf_unfiltered (gdb_stdlog,
6947 "infrun: switching back to stepped thread\n");
6949 if (keep_going_stepped_thread (stepping_thread))
6951 prepare_to_wait (ecs);
6960 /* Set a previously stepped thread back to stepping. Returns true on
6961 success, false if the resume is not possible (e.g., the thread
6965 keep_going_stepped_thread (struct thread_info *tp)
6967 struct frame_info *frame;
6968 struct gdbarch *gdbarch;
6969 struct execution_control_state ecss;
6970 struct execution_control_state *ecs = &ecss;
6972 /* If the stepping thread exited, then don't try to switch back and
6973 resume it, which could fail in several different ways depending
6974 on the target. Instead, just keep going.
6976 We can find a stepping dead thread in the thread list in two
6979 - The target supports thread exit events, and when the target
6980 tries to delete the thread from the thread list, inferior_ptid
6981 pointed at the exiting thread. In such case, calling
6982 delete_thread does not really remove the thread from the list;
6983 instead, the thread is left listed, with 'exited' state.
6985 - The target's debug interface does not support thread exit
6986 events, and so we have no idea whatsoever if the previously
6987 stepping thread is still alive. For that reason, we need to
6988 synchronously query the target now. */
6990 if (is_exited (tp->ptid)
6991 || !target_thread_alive (tp->ptid))
6994 fprintf_unfiltered (gdb_stdlog,
6995 "infrun: not resuming previously "
6996 "stepped thread, it has vanished\n");
6998 delete_thread (tp->ptid);
7003 fprintf_unfiltered (gdb_stdlog,
7004 "infrun: resuming previously stepped thread\n");
7006 reset_ecs (ecs, tp);
7007 switch_to_thread (tp->ptid);
7009 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7010 frame = get_current_frame ();
7011 gdbarch = get_frame_arch (frame);
7013 /* If the PC of the thread we were trying to single-step has
7014 changed, then that thread has trapped or been signaled, but the
7015 event has not been reported to GDB yet. Re-poll the target
7016 looking for this particular thread's event (i.e. temporarily
7017 enable schedlock) by:
7019 - setting a break at the current PC
7020 - resuming that particular thread, only (by setting trap
7023 This prevents us continuously moving the single-step breakpoint
7024 forward, one instruction at a time, overstepping. */
7026 if (stop_pc != tp->prev_pc)
7031 fprintf_unfiltered (gdb_stdlog,
7032 "infrun: expected thread advanced also (%s -> %s)\n",
7033 paddress (target_gdbarch (), tp->prev_pc),
7034 paddress (target_gdbarch (), stop_pc));
7036 /* Clear the info of the previous step-over, as it's no longer
7037 valid (if the thread was trying to step over a breakpoint, it
7038 has already succeeded). It's what keep_going would do too,
7039 if we called it. Do this before trying to insert the sss
7040 breakpoint, otherwise if we were previously trying to step
7041 over this exact address in another thread, the breakpoint is
7043 clear_step_over_info ();
7044 tp->control.trap_expected = 0;
7046 insert_single_step_breakpoint (get_frame_arch (frame),
7047 get_frame_address_space (frame),
7051 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7052 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7057 fprintf_unfiltered (gdb_stdlog,
7058 "infrun: expected thread still hasn't advanced\n");
7060 keep_going_pass_signal (ecs);
7065 /* Is thread TP in the middle of (software or hardware)
7066 single-stepping? (Note the result of this function must never be
7067 passed directly as target_resume's STEP parameter.) */
7070 currently_stepping (struct thread_info *tp)
7072 return ((tp->control.step_range_end
7073 && tp->control.step_resume_breakpoint == NULL)
7074 || tp->control.trap_expected
7075 || tp->stepped_breakpoint
7076 || bpstat_should_step ());
7079 /* Inferior has stepped into a subroutine call with source code that
7080 we should not step over. Do step to the first line of code in
7084 handle_step_into_function (struct gdbarch *gdbarch,
7085 struct execution_control_state *ecs)
7087 struct compunit_symtab *cust;
7088 struct symtab_and_line stop_func_sal, sr_sal;
7090 fill_in_stop_func (gdbarch, ecs);
7092 cust = find_pc_compunit_symtab (stop_pc);
7093 if (cust != NULL && compunit_language (cust) != language_asm)
7094 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7095 ecs->stop_func_start);
7097 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7098 /* Use the step_resume_break to step until the end of the prologue,
7099 even if that involves jumps (as it seems to on the vax under
7101 /* If the prologue ends in the middle of a source line, continue to
7102 the end of that source line (if it is still within the function).
7103 Otherwise, just go to end of prologue. */
7104 if (stop_func_sal.end
7105 && stop_func_sal.pc != ecs->stop_func_start
7106 && stop_func_sal.end < ecs->stop_func_end)
7107 ecs->stop_func_start = stop_func_sal.end;
7109 /* Architectures which require breakpoint adjustment might not be able
7110 to place a breakpoint at the computed address. If so, the test
7111 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7112 ecs->stop_func_start to an address at which a breakpoint may be
7113 legitimately placed.
7115 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7116 made, GDB will enter an infinite loop when stepping through
7117 optimized code consisting of VLIW instructions which contain
7118 subinstructions corresponding to different source lines. On
7119 FR-V, it's not permitted to place a breakpoint on any but the
7120 first subinstruction of a VLIW instruction. When a breakpoint is
7121 set, GDB will adjust the breakpoint address to the beginning of
7122 the VLIW instruction. Thus, we need to make the corresponding
7123 adjustment here when computing the stop address. */
7125 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7127 ecs->stop_func_start
7128 = gdbarch_adjust_breakpoint_address (gdbarch,
7129 ecs->stop_func_start);
7132 if (ecs->stop_func_start == stop_pc)
7134 /* We are already there: stop now. */
7135 end_stepping_range (ecs);
7140 /* Put the step-breakpoint there and go until there. */
7141 init_sal (&sr_sal); /* initialize to zeroes */
7142 sr_sal.pc = ecs->stop_func_start;
7143 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7144 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7146 /* Do not specify what the fp should be when we stop since on
7147 some machines the prologue is where the new fp value is
7149 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7151 /* And make sure stepping stops right away then. */
7152 ecs->event_thread->control.step_range_end
7153 = ecs->event_thread->control.step_range_start;
7158 /* Inferior has stepped backward into a subroutine call with source
7159 code that we should not step over. Do step to the beginning of the
7160 last line of code in it. */
7163 handle_step_into_function_backward (struct gdbarch *gdbarch,
7164 struct execution_control_state *ecs)
7166 struct compunit_symtab *cust;
7167 struct symtab_and_line stop_func_sal;
7169 fill_in_stop_func (gdbarch, ecs);
7171 cust = find_pc_compunit_symtab (stop_pc);
7172 if (cust != NULL && compunit_language (cust) != language_asm)
7173 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7174 ecs->stop_func_start);
7176 stop_func_sal = find_pc_line (stop_pc, 0);
7178 /* OK, we're just going to keep stepping here. */
7179 if (stop_func_sal.pc == stop_pc)
7181 /* We're there already. Just stop stepping now. */
7182 end_stepping_range (ecs);
7186 /* Else just reset the step range and keep going.
7187 No step-resume breakpoint, they don't work for
7188 epilogues, which can have multiple entry paths. */
7189 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7190 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7196 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7197 This is used to both functions and to skip over code. */
7200 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7201 struct symtab_and_line sr_sal,
7202 struct frame_id sr_id,
7203 enum bptype sr_type)
7205 /* There should never be more than one step-resume or longjmp-resume
7206 breakpoint per thread, so we should never be setting a new
7207 step_resume_breakpoint when one is already active. */
7208 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7209 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7212 fprintf_unfiltered (gdb_stdlog,
7213 "infrun: inserting step-resume breakpoint at %s\n",
7214 paddress (gdbarch, sr_sal.pc));
7216 inferior_thread ()->control.step_resume_breakpoint
7217 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7221 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7222 struct symtab_and_line sr_sal,
7223 struct frame_id sr_id)
7225 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7230 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7231 This is used to skip a potential signal handler.
7233 This is called with the interrupted function's frame. The signal
7234 handler, when it returns, will resume the interrupted function at
7238 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7240 struct symtab_and_line sr_sal;
7241 struct gdbarch *gdbarch;
7243 gdb_assert (return_frame != NULL);
7244 init_sal (&sr_sal); /* initialize to zeros */
7246 gdbarch = get_frame_arch (return_frame);
7247 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7248 sr_sal.section = find_pc_overlay (sr_sal.pc);
7249 sr_sal.pspace = get_frame_program_space (return_frame);
7251 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7252 get_stack_frame_id (return_frame),
7256 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7257 is used to skip a function after stepping into it (for "next" or if
7258 the called function has no debugging information).
7260 The current function has almost always been reached by single
7261 stepping a call or return instruction. NEXT_FRAME belongs to the
7262 current function, and the breakpoint will be set at the caller's
7265 This is a separate function rather than reusing
7266 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7267 get_prev_frame, which may stop prematurely (see the implementation
7268 of frame_unwind_caller_id for an example). */
7271 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7273 struct symtab_and_line sr_sal;
7274 struct gdbarch *gdbarch;
7276 /* We shouldn't have gotten here if we don't know where the call site
7278 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7280 init_sal (&sr_sal); /* initialize to zeros */
7282 gdbarch = frame_unwind_caller_arch (next_frame);
7283 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7284 frame_unwind_caller_pc (next_frame));
7285 sr_sal.section = find_pc_overlay (sr_sal.pc);
7286 sr_sal.pspace = frame_unwind_program_space (next_frame);
7288 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7289 frame_unwind_caller_id (next_frame));
7292 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7293 new breakpoint at the target of a jmp_buf. The handling of
7294 longjmp-resume uses the same mechanisms used for handling
7295 "step-resume" breakpoints. */
7298 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7300 /* There should never be more than one longjmp-resume breakpoint per
7301 thread, so we should never be setting a new
7302 longjmp_resume_breakpoint when one is already active. */
7303 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7306 fprintf_unfiltered (gdb_stdlog,
7307 "infrun: inserting longjmp-resume breakpoint at %s\n",
7308 paddress (gdbarch, pc));
7310 inferior_thread ()->control.exception_resume_breakpoint =
7311 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7314 /* Insert an exception resume breakpoint. TP is the thread throwing
7315 the exception. The block B is the block of the unwinder debug hook
7316 function. FRAME is the frame corresponding to the call to this
7317 function. SYM is the symbol of the function argument holding the
7318 target PC of the exception. */
7321 insert_exception_resume_breakpoint (struct thread_info *tp,
7322 const struct block *b,
7323 struct frame_info *frame,
7328 struct block_symbol vsym;
7329 struct value *value;
7331 struct breakpoint *bp;
7333 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7334 value = read_var_value (vsym.symbol, vsym.block, frame);
7335 /* If the value was optimized out, revert to the old behavior. */
7336 if (! value_optimized_out (value))
7338 handler = value_as_address (value);
7341 fprintf_unfiltered (gdb_stdlog,
7342 "infrun: exception resume at %lx\n",
7343 (unsigned long) handler);
7345 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7346 handler, bp_exception_resume);
7348 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7351 bp->thread = tp->num;
7352 inferior_thread ()->control.exception_resume_breakpoint = bp;
7355 CATCH (e, RETURN_MASK_ERROR)
7357 /* We want to ignore errors here. */
7362 /* A helper for check_exception_resume that sets an
7363 exception-breakpoint based on a SystemTap probe. */
7366 insert_exception_resume_from_probe (struct thread_info *tp,
7367 const struct bound_probe *probe,
7368 struct frame_info *frame)
7370 struct value *arg_value;
7372 struct breakpoint *bp;
7374 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7378 handler = value_as_address (arg_value);
7381 fprintf_unfiltered (gdb_stdlog,
7382 "infrun: exception resume at %s\n",
7383 paddress (get_objfile_arch (probe->objfile),
7386 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7387 handler, bp_exception_resume);
7388 bp->thread = tp->num;
7389 inferior_thread ()->control.exception_resume_breakpoint = bp;
7392 /* This is called when an exception has been intercepted. Check to
7393 see whether the exception's destination is of interest, and if so,
7394 set an exception resume breakpoint there. */
7397 check_exception_resume (struct execution_control_state *ecs,
7398 struct frame_info *frame)
7400 struct bound_probe probe;
7401 struct symbol *func;
7403 /* First see if this exception unwinding breakpoint was set via a
7404 SystemTap probe point. If so, the probe has two arguments: the
7405 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7406 set a breakpoint there. */
7407 probe = find_probe_by_pc (get_frame_pc (frame));
7410 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7414 func = get_frame_function (frame);
7420 const struct block *b;
7421 struct block_iterator iter;
7425 /* The exception breakpoint is a thread-specific breakpoint on
7426 the unwinder's debug hook, declared as:
7428 void _Unwind_DebugHook (void *cfa, void *handler);
7430 The CFA argument indicates the frame to which control is
7431 about to be transferred. HANDLER is the destination PC.
7433 We ignore the CFA and set a temporary breakpoint at HANDLER.
7434 This is not extremely efficient but it avoids issues in gdb
7435 with computing the DWARF CFA, and it also works even in weird
7436 cases such as throwing an exception from inside a signal
7439 b = SYMBOL_BLOCK_VALUE (func);
7440 ALL_BLOCK_SYMBOLS (b, iter, sym)
7442 if (!SYMBOL_IS_ARGUMENT (sym))
7449 insert_exception_resume_breakpoint (ecs->event_thread,
7455 CATCH (e, RETURN_MASK_ERROR)
7462 stop_waiting (struct execution_control_state *ecs)
7465 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7467 clear_step_over_info ();
7469 /* Let callers know we don't want to wait for the inferior anymore. */
7470 ecs->wait_some_more = 0;
7472 /* If all-stop, but the target is always in non-stop mode, stop all
7473 threads now that we're presenting the stop to the user. */
7474 if (!non_stop && target_is_non_stop_p ())
7475 stop_all_threads ();
7478 /* Like keep_going, but passes the signal to the inferior, even if the
7479 signal is set to nopass. */
7482 keep_going_pass_signal (struct execution_control_state *ecs)
7484 /* Make sure normal_stop is called if we get a QUIT handled before
7486 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7488 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7489 gdb_assert (!ecs->event_thread->resumed);
7491 /* Save the pc before execution, to compare with pc after stop. */
7492 ecs->event_thread->prev_pc
7493 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7495 if (ecs->event_thread->control.trap_expected)
7497 struct thread_info *tp = ecs->event_thread;
7500 fprintf_unfiltered (gdb_stdlog,
7501 "infrun: %s has trap_expected set, "
7502 "resuming to collect trap\n",
7503 target_pid_to_str (tp->ptid));
7505 /* We haven't yet gotten our trap, and either: intercepted a
7506 non-signal event (e.g., a fork); or took a signal which we
7507 are supposed to pass through to the inferior. Simply
7509 discard_cleanups (old_cleanups);
7510 resume (ecs->event_thread->suspend.stop_signal);
7512 else if (step_over_info_valid_p ())
7514 /* Another thread is stepping over a breakpoint in-line. If
7515 this thread needs a step-over too, queue the request. In
7516 either case, this resume must be deferred for later. */
7517 struct thread_info *tp = ecs->event_thread;
7519 if (ecs->hit_singlestep_breakpoint
7520 || thread_still_needs_step_over (tp))
7523 fprintf_unfiltered (gdb_stdlog,
7524 "infrun: step-over already in progress: "
7525 "step-over for %s deferred\n",
7526 target_pid_to_str (tp->ptid));
7527 thread_step_over_chain_enqueue (tp);
7532 fprintf_unfiltered (gdb_stdlog,
7533 "infrun: step-over in progress: "
7534 "resume of %s deferred\n",
7535 target_pid_to_str (tp->ptid));
7538 discard_cleanups (old_cleanups);
7542 struct regcache *regcache = get_current_regcache ();
7545 enum step_over_what step_what;
7547 /* Either the trap was not expected, but we are continuing
7548 anyway (if we got a signal, the user asked it be passed to
7551 We got our expected trap, but decided we should resume from
7554 We're going to run this baby now!
7556 Note that insert_breakpoints won't try to re-insert
7557 already inserted breakpoints. Therefore, we don't
7558 care if breakpoints were already inserted, or not. */
7560 /* If we need to step over a breakpoint, and we're not using
7561 displaced stepping to do so, insert all breakpoints
7562 (watchpoints, etc.) but the one we're stepping over, step one
7563 instruction, and then re-insert the breakpoint when that step
7566 step_what = thread_still_needs_step_over (ecs->event_thread);
7568 remove_bp = (ecs->hit_singlestep_breakpoint
7569 || (step_what & STEP_OVER_BREAKPOINT));
7570 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7572 /* We can't use displaced stepping if we need to step past a
7573 watchpoint. The instruction copied to the scratch pad would
7574 still trigger the watchpoint. */
7576 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7578 set_step_over_info (get_regcache_aspace (regcache),
7579 regcache_read_pc (regcache), remove_wps);
7581 else if (remove_wps)
7582 set_step_over_info (NULL, 0, remove_wps);
7584 /* If we now need to do an in-line step-over, we need to stop
7585 all other threads. Note this must be done before
7586 insert_breakpoints below, because that removes the breakpoint
7587 we're about to step over, otherwise other threads could miss
7589 if (step_over_info_valid_p () && target_is_non_stop_p ())
7590 stop_all_threads ();
7592 /* Stop stepping if inserting breakpoints fails. */
7595 insert_breakpoints ();
7597 CATCH (e, RETURN_MASK_ERROR)
7599 exception_print (gdb_stderr, e);
7601 discard_cleanups (old_cleanups);
7606 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7608 discard_cleanups (old_cleanups);
7609 resume (ecs->event_thread->suspend.stop_signal);
7612 prepare_to_wait (ecs);
7615 /* Called when we should continue running the inferior, because the
7616 current event doesn't cause a user visible stop. This does the
7617 resuming part; waiting for the next event is done elsewhere. */
7620 keep_going (struct execution_control_state *ecs)
7622 if (ecs->event_thread->control.trap_expected
7623 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7624 ecs->event_thread->control.trap_expected = 0;
7626 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7627 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7628 keep_going_pass_signal (ecs);
7631 /* This function normally comes after a resume, before
7632 handle_inferior_event exits. It takes care of any last bits of
7633 housekeeping, and sets the all-important wait_some_more flag. */
7636 prepare_to_wait (struct execution_control_state *ecs)
7639 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7641 ecs->wait_some_more = 1;
7643 if (!target_is_async_p ())
7644 mark_infrun_async_event_handler ();
7647 /* We are done with the step range of a step/next/si/ni command.
7648 Called once for each n of a "step n" operation. */
7651 end_stepping_range (struct execution_control_state *ecs)
7653 ecs->event_thread->control.stop_step = 1;
7657 /* Several print_*_reason functions to print why the inferior has stopped.
7658 We always print something when the inferior exits, or receives a signal.
7659 The rest of the cases are dealt with later on in normal_stop and
7660 print_it_typical. Ideally there should be a call to one of these
7661 print_*_reason functions functions from handle_inferior_event each time
7662 stop_waiting is called.
7664 Note that we don't call these directly, instead we delegate that to
7665 the interpreters, through observers. Interpreters then call these
7666 with whatever uiout is right. */
7669 print_end_stepping_range_reason (struct ui_out *uiout)
7671 /* For CLI-like interpreters, print nothing. */
7673 if (ui_out_is_mi_like_p (uiout))
7675 ui_out_field_string (uiout, "reason",
7676 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7681 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7683 annotate_signalled ();
7684 if (ui_out_is_mi_like_p (uiout))
7686 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7687 ui_out_text (uiout, "\nProgram terminated with signal ");
7688 annotate_signal_name ();
7689 ui_out_field_string (uiout, "signal-name",
7690 gdb_signal_to_name (siggnal));
7691 annotate_signal_name_end ();
7692 ui_out_text (uiout, ", ");
7693 annotate_signal_string ();
7694 ui_out_field_string (uiout, "signal-meaning",
7695 gdb_signal_to_string (siggnal));
7696 annotate_signal_string_end ();
7697 ui_out_text (uiout, ".\n");
7698 ui_out_text (uiout, "The program no longer exists.\n");
7702 print_exited_reason (struct ui_out *uiout, int exitstatus)
7704 struct inferior *inf = current_inferior ();
7705 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7707 annotate_exited (exitstatus);
7710 if (ui_out_is_mi_like_p (uiout))
7711 ui_out_field_string (uiout, "reason",
7712 async_reason_lookup (EXEC_ASYNC_EXITED));
7713 ui_out_text (uiout, "[Inferior ");
7714 ui_out_text (uiout, plongest (inf->num));
7715 ui_out_text (uiout, " (");
7716 ui_out_text (uiout, pidstr);
7717 ui_out_text (uiout, ") exited with code ");
7718 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
7719 ui_out_text (uiout, "]\n");
7723 if (ui_out_is_mi_like_p (uiout))
7725 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7726 ui_out_text (uiout, "[Inferior ");
7727 ui_out_text (uiout, plongest (inf->num));
7728 ui_out_text (uiout, " (");
7729 ui_out_text (uiout, pidstr);
7730 ui_out_text (uiout, ") exited normally]\n");
7735 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7739 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
7741 struct thread_info *t = inferior_thread ();
7743 ui_out_text (uiout, "\n[");
7744 ui_out_field_string (uiout, "thread-name",
7745 target_pid_to_str (t->ptid));
7746 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
7747 ui_out_text (uiout, " stopped");
7751 ui_out_text (uiout, "\nProgram received signal ");
7752 annotate_signal_name ();
7753 if (ui_out_is_mi_like_p (uiout))
7755 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7756 ui_out_field_string (uiout, "signal-name",
7757 gdb_signal_to_name (siggnal));
7758 annotate_signal_name_end ();
7759 ui_out_text (uiout, ", ");
7760 annotate_signal_string ();
7761 ui_out_field_string (uiout, "signal-meaning",
7762 gdb_signal_to_string (siggnal));
7763 annotate_signal_string_end ();
7765 ui_out_text (uiout, ".\n");
7769 print_no_history_reason (struct ui_out *uiout)
7771 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
7774 /* Print current location without a level number, if we have changed
7775 functions or hit a breakpoint. Print source line if we have one.
7776 bpstat_print contains the logic deciding in detail what to print,
7777 based on the event(s) that just occurred. */
7780 print_stop_location (struct target_waitstatus *ws)
7783 enum print_what source_flag;
7784 int do_frame_printing = 1;
7785 struct thread_info *tp = inferior_thread ();
7787 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7791 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7792 should) carry around the function and does (or should) use
7793 that when doing a frame comparison. */
7794 if (tp->control.stop_step
7795 && frame_id_eq (tp->control.step_frame_id,
7796 get_frame_id (get_current_frame ()))
7797 && tp->control.step_start_function == find_pc_function (stop_pc))
7799 /* Finished step, just print source line. */
7800 source_flag = SRC_LINE;
7804 /* Print location and source line. */
7805 source_flag = SRC_AND_LOC;
7808 case PRINT_SRC_AND_LOC:
7809 /* Print location and source line. */
7810 source_flag = SRC_AND_LOC;
7812 case PRINT_SRC_ONLY:
7813 source_flag = SRC_LINE;
7816 /* Something bogus. */
7817 source_flag = SRC_LINE;
7818 do_frame_printing = 0;
7821 internal_error (__FILE__, __LINE__, _("Unknown value."));
7824 /* The behavior of this routine with respect to the source
7826 SRC_LINE: Print only source line
7827 LOCATION: Print only location
7828 SRC_AND_LOC: Print location and source line. */
7829 if (do_frame_printing)
7830 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7833 /* Cleanup that restores a previous current uiout. */
7836 restore_current_uiout_cleanup (void *arg)
7838 struct ui_out *saved_uiout = arg;
7840 current_uiout = saved_uiout;
7846 print_stop_event (struct ui_out *uiout)
7848 struct cleanup *old_chain;
7849 struct target_waitstatus last;
7851 struct thread_info *tp;
7853 get_last_target_status (&last_ptid, &last);
7855 old_chain = make_cleanup (restore_current_uiout_cleanup, current_uiout);
7856 current_uiout = uiout;
7858 print_stop_location (&last);
7860 /* Display the auto-display expressions. */
7863 do_cleanups (old_chain);
7865 tp = inferior_thread ();
7866 if (tp->thread_fsm != NULL
7867 && thread_fsm_finished_p (tp->thread_fsm))
7869 struct return_value_info *rv;
7871 rv = thread_fsm_return_value (tp->thread_fsm);
7873 print_return_value (uiout, rv);
7880 maybe_remove_breakpoints (void)
7882 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7884 if (remove_breakpoints ())
7886 target_terminal_ours_for_output ();
7887 printf_filtered (_("Cannot remove breakpoints because "
7888 "program is no longer writable.\nFurther "
7889 "execution is probably impossible.\n"));
7894 /* The execution context that just caused a normal stop. */
7901 /* The event PTID. */
7905 /* If stopp for a thread event, this is the thread that caused the
7907 struct thread_info *thread;
7909 /* The inferior that caused the stop. */
7913 /* Returns a new stop context. If stopped for a thread event, this
7914 takes a strong reference to the thread. */
7916 static struct stop_context *
7917 save_stop_context (void)
7919 struct stop_context *sc = xmalloc (sizeof (struct stop_context));
7921 sc->stop_id = get_stop_id ();
7922 sc->ptid = inferior_ptid;
7923 sc->inf_num = current_inferior ()->num;
7925 if (!ptid_equal (inferior_ptid, null_ptid))
7927 /* Take a strong reference so that the thread can't be deleted
7929 sc->thread = inferior_thread ();
7930 sc->thread->refcount++;
7938 /* Release a stop context previously created with save_stop_context.
7939 Releases the strong reference to the thread as well. */
7942 release_stop_context_cleanup (void *arg)
7944 struct stop_context *sc = arg;
7946 if (sc->thread != NULL)
7947 sc->thread->refcount--;
7951 /* Return true if the current context no longer matches the saved stop
7955 stop_context_changed (struct stop_context *prev)
7957 if (!ptid_equal (prev->ptid, inferior_ptid))
7959 if (prev->inf_num != current_inferior ()->num)
7961 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
7963 if (get_stop_id () != prev->stop_id)
7973 struct target_waitstatus last;
7975 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
7978 get_last_target_status (&last_ptid, &last);
7982 /* If an exception is thrown from this point on, make sure to
7983 propagate GDB's knowledge of the executing state to the
7984 frontend/user running state. A QUIT is an easy exception to see
7985 here, so do this before any filtered output. */
7987 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
7988 else if (last.kind == TARGET_WAITKIND_SIGNALLED
7989 || last.kind == TARGET_WAITKIND_EXITED)
7991 /* On some targets, we may still have live threads in the
7992 inferior when we get a process exit event. E.g., for
7993 "checkpoint", when the current checkpoint/fork exits,
7994 linux-fork.c automatically switches to another fork from
7995 within target_mourn_inferior. */
7996 if (!ptid_equal (inferior_ptid, null_ptid))
7998 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
7999 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
8002 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8003 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
8005 /* As we're presenting a stop, and potentially removing breakpoints,
8006 update the thread list so we can tell whether there are threads
8007 running on the target. With target remote, for example, we can
8008 only learn about new threads when we explicitly update the thread
8009 list. Do this before notifying the interpreters about signal
8010 stops, end of stepping ranges, etc., so that the "new thread"
8011 output is emitted before e.g., "Program received signal FOO",
8012 instead of after. */
8013 update_thread_list ();
8015 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8016 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
8018 /* As with the notification of thread events, we want to delay
8019 notifying the user that we've switched thread context until
8020 the inferior actually stops.
8022 There's no point in saying anything if the inferior has exited.
8023 Note that SIGNALLED here means "exited with a signal", not
8024 "received a signal".
8026 Also skip saying anything in non-stop mode. In that mode, as we
8027 don't want GDB to switch threads behind the user's back, to avoid
8028 races where the user is typing a command to apply to thread x,
8029 but GDB switches to thread y before the user finishes entering
8030 the command, fetch_inferior_event installs a cleanup to restore
8031 the current thread back to the thread the user had selected right
8032 after this event is handled, so we're not really switching, only
8033 informing of a stop. */
8035 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8036 && target_has_execution
8037 && last.kind != TARGET_WAITKIND_SIGNALLED
8038 && last.kind != TARGET_WAITKIND_EXITED
8039 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8041 target_terminal_ours_for_output ();
8042 printf_filtered (_("[Switching to %s]\n"),
8043 target_pid_to_str (inferior_ptid));
8044 annotate_thread_changed ();
8045 previous_inferior_ptid = inferior_ptid;
8048 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8050 gdb_assert (sync_execution || !target_can_async_p ());
8052 target_terminal_ours_for_output ();
8053 printf_filtered (_("No unwaited-for children left.\n"));
8056 /* Note: this depends on the update_thread_list call above. */
8057 maybe_remove_breakpoints ();
8059 /* If an auto-display called a function and that got a signal,
8060 delete that auto-display to avoid an infinite recursion. */
8062 if (stopped_by_random_signal)
8063 disable_current_display ();
8065 target_terminal_ours ();
8066 async_enable_stdin ();
8068 /* Let the user/frontend see the threads as stopped. */
8069 do_cleanups (old_chain);
8071 /* Select innermost stack frame - i.e., current frame is frame 0,
8072 and current location is based on that. Handle the case where the
8073 dummy call is returning after being stopped. E.g. the dummy call
8074 previously hit a breakpoint. (If the dummy call returns
8075 normally, we won't reach here.) Do this before the stop hook is
8076 run, so that it doesn't get to see the temporary dummy frame,
8077 which is not where we'll present the stop. */
8078 if (has_stack_frames ())
8080 if (stop_stack_dummy == STOP_STACK_DUMMY)
8082 /* Pop the empty frame that contains the stack dummy. This
8083 also restores inferior state prior to the call (struct
8084 infcall_suspend_state). */
8085 struct frame_info *frame = get_current_frame ();
8087 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8089 /* frame_pop calls reinit_frame_cache as the last thing it
8090 does which means there's now no selected frame. */
8093 select_frame (get_current_frame ());
8095 /* Set the current source location. */
8096 set_current_sal_from_frame (get_current_frame ());
8099 /* Look up the hook_stop and run it (CLI internally handles problem
8100 of stop_command's pre-hook not existing). */
8101 if (stop_command != NULL)
8103 struct stop_context *saved_context = save_stop_context ();
8104 struct cleanup *old_chain
8105 = make_cleanup (release_stop_context_cleanup, saved_context);
8107 catch_errors (hook_stop_stub, stop_command,
8108 "Error while running hook_stop:\n", RETURN_MASK_ALL);
8110 /* If the stop hook resumes the target, then there's no point in
8111 trying to notify about the previous stop; its context is
8112 gone. Likewise if the command switches thread or inferior --
8113 the observers would print a stop for the wrong
8115 if (stop_context_changed (saved_context))
8117 do_cleanups (old_chain);
8120 do_cleanups (old_chain);
8123 /* Notify observers about the stop. This is where the interpreters
8124 print the stop event. */
8125 if (!ptid_equal (inferior_ptid, null_ptid))
8126 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8129 observer_notify_normal_stop (NULL, stop_print_frame);
8131 annotate_stopped ();
8133 if (target_has_execution)
8135 if (last.kind != TARGET_WAITKIND_SIGNALLED
8136 && last.kind != TARGET_WAITKIND_EXITED)
8137 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8138 Delete any breakpoint that is to be deleted at the next stop. */
8139 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8142 /* Try to get rid of automatically added inferiors that are no
8143 longer needed. Keeping those around slows down things linearly.
8144 Note that this never removes the current inferior. */
8151 hook_stop_stub (void *cmd)
8153 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
8158 signal_stop_state (int signo)
8160 return signal_stop[signo];
8164 signal_print_state (int signo)
8166 return signal_print[signo];
8170 signal_pass_state (int signo)
8172 return signal_program[signo];
8176 signal_cache_update (int signo)
8180 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8181 signal_cache_update (signo);
8186 signal_pass[signo] = (signal_stop[signo] == 0
8187 && signal_print[signo] == 0
8188 && signal_program[signo] == 1
8189 && signal_catch[signo] == 0);
8193 signal_stop_update (int signo, int state)
8195 int ret = signal_stop[signo];
8197 signal_stop[signo] = state;
8198 signal_cache_update (signo);
8203 signal_print_update (int signo, int state)
8205 int ret = signal_print[signo];
8207 signal_print[signo] = state;
8208 signal_cache_update (signo);
8213 signal_pass_update (int signo, int state)
8215 int ret = signal_program[signo];
8217 signal_program[signo] = state;
8218 signal_cache_update (signo);
8222 /* Update the global 'signal_catch' from INFO and notify the
8226 signal_catch_update (const unsigned int *info)
8230 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8231 signal_catch[i] = info[i] > 0;
8232 signal_cache_update (-1);
8233 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8237 sig_print_header (void)
8239 printf_filtered (_("Signal Stop\tPrint\tPass "
8240 "to program\tDescription\n"));
8244 sig_print_info (enum gdb_signal oursig)
8246 const char *name = gdb_signal_to_name (oursig);
8247 int name_padding = 13 - strlen (name);
8249 if (name_padding <= 0)
8252 printf_filtered ("%s", name);
8253 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8254 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8255 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8256 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8257 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8260 /* Specify how various signals in the inferior should be handled. */
8263 handle_command (char *args, int from_tty)
8266 int digits, wordlen;
8267 int sigfirst, signum, siglast;
8268 enum gdb_signal oursig;
8271 unsigned char *sigs;
8272 struct cleanup *old_chain;
8276 error_no_arg (_("signal to handle"));
8279 /* Allocate and zero an array of flags for which signals to handle. */
8281 nsigs = (int) GDB_SIGNAL_LAST;
8282 sigs = (unsigned char *) alloca (nsigs);
8283 memset (sigs, 0, nsigs);
8285 /* Break the command line up into args. */
8287 argv = gdb_buildargv (args);
8288 old_chain = make_cleanup_freeargv (argv);
8290 /* Walk through the args, looking for signal oursigs, signal names, and
8291 actions. Signal numbers and signal names may be interspersed with
8292 actions, with the actions being performed for all signals cumulatively
8293 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8295 while (*argv != NULL)
8297 wordlen = strlen (*argv);
8298 for (digits = 0; isdigit ((*argv)[digits]); digits++)
8302 sigfirst = siglast = -1;
8304 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
8306 /* Apply action to all signals except those used by the
8307 debugger. Silently skip those. */
8310 siglast = nsigs - 1;
8312 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
8314 SET_SIGS (nsigs, sigs, signal_stop);
8315 SET_SIGS (nsigs, sigs, signal_print);
8317 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
8319 UNSET_SIGS (nsigs, sigs, signal_program);
8321 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
8323 SET_SIGS (nsigs, sigs, signal_print);
8325 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
8327 SET_SIGS (nsigs, sigs, signal_program);
8329 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
8331 UNSET_SIGS (nsigs, sigs, signal_stop);
8333 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
8335 SET_SIGS (nsigs, sigs, signal_program);
8337 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
8339 UNSET_SIGS (nsigs, sigs, signal_print);
8340 UNSET_SIGS (nsigs, sigs, signal_stop);
8342 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
8344 UNSET_SIGS (nsigs, sigs, signal_program);
8346 else if (digits > 0)
8348 /* It is numeric. The numeric signal refers to our own
8349 internal signal numbering from target.h, not to host/target
8350 signal number. This is a feature; users really should be
8351 using symbolic names anyway, and the common ones like
8352 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8354 sigfirst = siglast = (int)
8355 gdb_signal_from_command (atoi (*argv));
8356 if ((*argv)[digits] == '-')
8359 gdb_signal_from_command (atoi ((*argv) + digits + 1));
8361 if (sigfirst > siglast)
8363 /* Bet he didn't figure we'd think of this case... */
8371 oursig = gdb_signal_from_name (*argv);
8372 if (oursig != GDB_SIGNAL_UNKNOWN)
8374 sigfirst = siglast = (int) oursig;
8378 /* Not a number and not a recognized flag word => complain. */
8379 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
8383 /* If any signal numbers or symbol names were found, set flags for
8384 which signals to apply actions to. */
8386 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8388 switch ((enum gdb_signal) signum)
8390 case GDB_SIGNAL_TRAP:
8391 case GDB_SIGNAL_INT:
8392 if (!allsigs && !sigs[signum])
8394 if (query (_("%s is used by the debugger.\n\
8395 Are you sure you want to change it? "),
8396 gdb_signal_to_name ((enum gdb_signal) signum)))
8402 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8403 gdb_flush (gdb_stdout);
8408 case GDB_SIGNAL_DEFAULT:
8409 case GDB_SIGNAL_UNKNOWN:
8410 /* Make sure that "all" doesn't print these. */
8421 for (signum = 0; signum < nsigs; signum++)
8424 signal_cache_update (-1);
8425 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8426 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8430 /* Show the results. */
8431 sig_print_header ();
8432 for (; signum < nsigs; signum++)
8434 sig_print_info ((enum gdb_signal) signum);
8440 do_cleanups (old_chain);
8443 /* Complete the "handle" command. */
8445 static VEC (char_ptr) *
8446 handle_completer (struct cmd_list_element *ignore,
8447 const char *text, const char *word)
8449 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
8450 static const char * const keywords[] =
8464 vec_signals = signal_completer (ignore, text, word);
8465 vec_keywords = complete_on_enum (keywords, word, word);
8467 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
8468 VEC_free (char_ptr, vec_signals);
8469 VEC_free (char_ptr, vec_keywords);
8474 gdb_signal_from_command (int num)
8476 if (num >= 1 && num <= 15)
8477 return (enum gdb_signal) num;
8478 error (_("Only signals 1-15 are valid as numeric signals.\n\
8479 Use \"info signals\" for a list of symbolic signals."));
8482 /* Print current contents of the tables set by the handle command.
8483 It is possible we should just be printing signals actually used
8484 by the current target (but for things to work right when switching
8485 targets, all signals should be in the signal tables). */
8488 signals_info (char *signum_exp, int from_tty)
8490 enum gdb_signal oursig;
8492 sig_print_header ();
8496 /* First see if this is a symbol name. */
8497 oursig = gdb_signal_from_name (signum_exp);
8498 if (oursig == GDB_SIGNAL_UNKNOWN)
8500 /* No, try numeric. */
8502 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8504 sig_print_info (oursig);
8508 printf_filtered ("\n");
8509 /* These ugly casts brought to you by the native VAX compiler. */
8510 for (oursig = GDB_SIGNAL_FIRST;
8511 (int) oursig < (int) GDB_SIGNAL_LAST;
8512 oursig = (enum gdb_signal) ((int) oursig + 1))
8516 if (oursig != GDB_SIGNAL_UNKNOWN
8517 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8518 sig_print_info (oursig);
8521 printf_filtered (_("\nUse the \"handle\" command "
8522 "to change these tables.\n"));
8525 /* Check if it makes sense to read $_siginfo from the current thread
8526 at this point. If not, throw an error. */
8529 validate_siginfo_access (void)
8531 /* No current inferior, no siginfo. */
8532 if (ptid_equal (inferior_ptid, null_ptid))
8533 error (_("No thread selected."));
8535 /* Don't try to read from a dead thread. */
8536 if (is_exited (inferior_ptid))
8537 error (_("The current thread has terminated"));
8539 /* ... or from a spinning thread. */
8540 if (is_running (inferior_ptid))
8541 error (_("Selected thread is running."));
8544 /* The $_siginfo convenience variable is a bit special. We don't know
8545 for sure the type of the value until we actually have a chance to
8546 fetch the data. The type can change depending on gdbarch, so it is
8547 also dependent on which thread you have selected.
8549 1. making $_siginfo be an internalvar that creates a new value on
8552 2. making the value of $_siginfo be an lval_computed value. */
8554 /* This function implements the lval_computed support for reading a
8558 siginfo_value_read (struct value *v)
8560 LONGEST transferred;
8562 validate_siginfo_access ();
8565 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8567 value_contents_all_raw (v),
8569 TYPE_LENGTH (value_type (v)));
8571 if (transferred != TYPE_LENGTH (value_type (v)))
8572 error (_("Unable to read siginfo"));
8575 /* This function implements the lval_computed support for writing a
8579 siginfo_value_write (struct value *v, struct value *fromval)
8581 LONGEST transferred;
8583 validate_siginfo_access ();
8585 transferred = target_write (¤t_target,
8586 TARGET_OBJECT_SIGNAL_INFO,
8588 value_contents_all_raw (fromval),
8590 TYPE_LENGTH (value_type (fromval)));
8592 if (transferred != TYPE_LENGTH (value_type (fromval)))
8593 error (_("Unable to write siginfo"));
8596 static const struct lval_funcs siginfo_value_funcs =
8602 /* Return a new value with the correct type for the siginfo object of
8603 the current thread using architecture GDBARCH. Return a void value
8604 if there's no object available. */
8606 static struct value *
8607 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8610 if (target_has_stack
8611 && !ptid_equal (inferior_ptid, null_ptid)
8612 && gdbarch_get_siginfo_type_p (gdbarch))
8614 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8616 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8619 return allocate_value (builtin_type (gdbarch)->builtin_void);
8623 /* infcall_suspend_state contains state about the program itself like its
8624 registers and any signal it received when it last stopped.
8625 This state must be restored regardless of how the inferior function call
8626 ends (either successfully, or after it hits a breakpoint or signal)
8627 if the program is to properly continue where it left off. */
8629 struct infcall_suspend_state
8631 struct thread_suspend_state thread_suspend;
8635 struct regcache *registers;
8637 /* Format of SIGINFO_DATA or NULL if it is not present. */
8638 struct gdbarch *siginfo_gdbarch;
8640 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8641 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8642 content would be invalid. */
8643 gdb_byte *siginfo_data;
8646 struct infcall_suspend_state *
8647 save_infcall_suspend_state (void)
8649 struct infcall_suspend_state *inf_state;
8650 struct thread_info *tp = inferior_thread ();
8651 struct regcache *regcache = get_current_regcache ();
8652 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8653 gdb_byte *siginfo_data = NULL;
8655 if (gdbarch_get_siginfo_type_p (gdbarch))
8657 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8658 size_t len = TYPE_LENGTH (type);
8659 struct cleanup *back_to;
8661 siginfo_data = xmalloc (len);
8662 back_to = make_cleanup (xfree, siginfo_data);
8664 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8665 siginfo_data, 0, len) == len)
8666 discard_cleanups (back_to);
8669 /* Errors ignored. */
8670 do_cleanups (back_to);
8671 siginfo_data = NULL;
8675 inf_state = XCNEW (struct infcall_suspend_state);
8679 inf_state->siginfo_gdbarch = gdbarch;
8680 inf_state->siginfo_data = siginfo_data;
8683 inf_state->thread_suspend = tp->suspend;
8685 /* run_inferior_call will not use the signal due to its `proceed' call with
8686 GDB_SIGNAL_0 anyway. */
8687 tp->suspend.stop_signal = GDB_SIGNAL_0;
8689 inf_state->stop_pc = stop_pc;
8691 inf_state->registers = regcache_dup (regcache);
8696 /* Restore inferior session state to INF_STATE. */
8699 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8701 struct thread_info *tp = inferior_thread ();
8702 struct regcache *regcache = get_current_regcache ();
8703 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8705 tp->suspend = inf_state->thread_suspend;
8707 stop_pc = inf_state->stop_pc;
8709 if (inf_state->siginfo_gdbarch == gdbarch)
8711 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8713 /* Errors ignored. */
8714 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8715 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8718 /* The inferior can be gone if the user types "print exit(0)"
8719 (and perhaps other times). */
8720 if (target_has_execution)
8721 /* NB: The register write goes through to the target. */
8722 regcache_cpy (regcache, inf_state->registers);
8724 discard_infcall_suspend_state (inf_state);
8728 do_restore_infcall_suspend_state_cleanup (void *state)
8730 restore_infcall_suspend_state (state);
8734 make_cleanup_restore_infcall_suspend_state
8735 (struct infcall_suspend_state *inf_state)
8737 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8741 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8743 regcache_xfree (inf_state->registers);
8744 xfree (inf_state->siginfo_data);
8749 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8751 return inf_state->registers;
8754 /* infcall_control_state contains state regarding gdb's control of the
8755 inferior itself like stepping control. It also contains session state like
8756 the user's currently selected frame. */
8758 struct infcall_control_state
8760 struct thread_control_state thread_control;
8761 struct inferior_control_state inferior_control;
8764 enum stop_stack_kind stop_stack_dummy;
8765 int stopped_by_random_signal;
8766 int stop_after_trap;
8768 /* ID if the selected frame when the inferior function call was made. */
8769 struct frame_id selected_frame_id;
8772 /* Save all of the information associated with the inferior<==>gdb
8775 struct infcall_control_state *
8776 save_infcall_control_state (void)
8778 struct infcall_control_state *inf_status =
8779 XNEW (struct infcall_control_state);
8780 struct thread_info *tp = inferior_thread ();
8781 struct inferior *inf = current_inferior ();
8783 inf_status->thread_control = tp->control;
8784 inf_status->inferior_control = inf->control;
8786 tp->control.step_resume_breakpoint = NULL;
8787 tp->control.exception_resume_breakpoint = NULL;
8789 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8790 chain. If caller's caller is walking the chain, they'll be happier if we
8791 hand them back the original chain when restore_infcall_control_state is
8793 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8796 inf_status->stop_stack_dummy = stop_stack_dummy;
8797 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8798 inf_status->stop_after_trap = stop_after_trap;
8800 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8806 restore_selected_frame (void *args)
8808 struct frame_id *fid = (struct frame_id *) args;
8809 struct frame_info *frame;
8811 frame = frame_find_by_id (*fid);
8813 /* If inf_status->selected_frame_id is NULL, there was no previously
8817 warning (_("Unable to restore previously selected frame."));
8821 select_frame (frame);
8826 /* Restore inferior session state to INF_STATUS. */
8829 restore_infcall_control_state (struct infcall_control_state *inf_status)
8831 struct thread_info *tp = inferior_thread ();
8832 struct inferior *inf = current_inferior ();
8834 if (tp->control.step_resume_breakpoint)
8835 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8837 if (tp->control.exception_resume_breakpoint)
8838 tp->control.exception_resume_breakpoint->disposition
8839 = disp_del_at_next_stop;
8841 /* Handle the bpstat_copy of the chain. */
8842 bpstat_clear (&tp->control.stop_bpstat);
8844 tp->control = inf_status->thread_control;
8845 inf->control = inf_status->inferior_control;
8848 stop_stack_dummy = inf_status->stop_stack_dummy;
8849 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8850 stop_after_trap = inf_status->stop_after_trap;
8852 if (target_has_stack)
8854 /* The point of catch_errors is that if the stack is clobbered,
8855 walking the stack might encounter a garbage pointer and
8856 error() trying to dereference it. */
8858 (restore_selected_frame, &inf_status->selected_frame_id,
8859 "Unable to restore previously selected frame:\n",
8860 RETURN_MASK_ERROR) == 0)
8861 /* Error in restoring the selected frame. Select the innermost
8863 select_frame (get_current_frame ());
8870 do_restore_infcall_control_state_cleanup (void *sts)
8872 restore_infcall_control_state (sts);
8876 make_cleanup_restore_infcall_control_state
8877 (struct infcall_control_state *inf_status)
8879 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
8883 discard_infcall_control_state (struct infcall_control_state *inf_status)
8885 if (inf_status->thread_control.step_resume_breakpoint)
8886 inf_status->thread_control.step_resume_breakpoint->disposition
8887 = disp_del_at_next_stop;
8889 if (inf_status->thread_control.exception_resume_breakpoint)
8890 inf_status->thread_control.exception_resume_breakpoint->disposition
8891 = disp_del_at_next_stop;
8893 /* See save_infcall_control_state for info on stop_bpstat. */
8894 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8899 /* restore_inferior_ptid() will be used by the cleanup machinery
8900 to restore the inferior_ptid value saved in a call to
8901 save_inferior_ptid(). */
8904 restore_inferior_ptid (void *arg)
8906 ptid_t *saved_ptid_ptr = arg;
8908 inferior_ptid = *saved_ptid_ptr;
8912 /* Save the value of inferior_ptid so that it may be restored by a
8913 later call to do_cleanups(). Returns the struct cleanup pointer
8914 needed for later doing the cleanup. */
8917 save_inferior_ptid (void)
8919 ptid_t *saved_ptid_ptr = XNEW (ptid_t);
8921 *saved_ptid_ptr = inferior_ptid;
8922 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
8928 clear_exit_convenience_vars (void)
8930 clear_internalvar (lookup_internalvar ("_exitsignal"));
8931 clear_internalvar (lookup_internalvar ("_exitcode"));
8935 /* User interface for reverse debugging:
8936 Set exec-direction / show exec-direction commands
8937 (returns error unless target implements to_set_exec_direction method). */
8939 int execution_direction = EXEC_FORWARD;
8940 static const char exec_forward[] = "forward";
8941 static const char exec_reverse[] = "reverse";
8942 static const char *exec_direction = exec_forward;
8943 static const char *const exec_direction_names[] = {
8950 set_exec_direction_func (char *args, int from_tty,
8951 struct cmd_list_element *cmd)
8953 if (target_can_execute_reverse)
8955 if (!strcmp (exec_direction, exec_forward))
8956 execution_direction = EXEC_FORWARD;
8957 else if (!strcmp (exec_direction, exec_reverse))
8958 execution_direction = EXEC_REVERSE;
8962 exec_direction = exec_forward;
8963 error (_("Target does not support this operation."));
8968 show_exec_direction_func (struct ui_file *out, int from_tty,
8969 struct cmd_list_element *cmd, const char *value)
8971 switch (execution_direction) {
8973 fprintf_filtered (out, _("Forward.\n"));
8976 fprintf_filtered (out, _("Reverse.\n"));
8979 internal_error (__FILE__, __LINE__,
8980 _("bogus execution_direction value: %d"),
8981 (int) execution_direction);
8986 show_schedule_multiple (struct ui_file *file, int from_tty,
8987 struct cmd_list_element *c, const char *value)
8989 fprintf_filtered (file, _("Resuming the execution of threads "
8990 "of all processes is %s.\n"), value);
8993 /* Implementation of `siginfo' variable. */
8995 static const struct internalvar_funcs siginfo_funcs =
9002 /* Callback for infrun's target events source. This is marked when a
9003 thread has a pending status to process. */
9006 infrun_async_inferior_event_handler (gdb_client_data data)
9008 inferior_event_handler (INF_REG_EVENT, NULL);
9012 _initialize_infrun (void)
9016 struct cmd_list_element *c;
9018 /* Register extra event sources in the event loop. */
9019 infrun_async_inferior_event_token
9020 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9022 add_info ("signals", signals_info, _("\
9023 What debugger does when program gets various signals.\n\
9024 Specify a signal as argument to print info on that signal only."));
9025 add_info_alias ("handle", "signals", 0);
9027 c = add_com ("handle", class_run, handle_command, _("\
9028 Specify how to handle signals.\n\
9029 Usage: handle SIGNAL [ACTIONS]\n\
9030 Args are signals and actions to apply to those signals.\n\
9031 If no actions are specified, the current settings for the specified signals\n\
9032 will be displayed instead.\n\
9034 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9035 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9036 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9037 The special arg \"all\" is recognized to mean all signals except those\n\
9038 used by the debugger, typically SIGTRAP and SIGINT.\n\
9040 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9041 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9042 Stop means reenter debugger if this signal happens (implies print).\n\
9043 Print means print a message if this signal happens.\n\
9044 Pass means let program see this signal; otherwise program doesn't know.\n\
9045 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9046 Pass and Stop may be combined.\n\
9048 Multiple signals may be specified. Signal numbers and signal names\n\
9049 may be interspersed with actions, with the actions being performed for\n\
9050 all signals cumulatively specified."));
9051 set_cmd_completer (c, handle_completer);
9054 stop_command = add_cmd ("stop", class_obscure,
9055 not_just_help_class_command, _("\
9056 There is no `stop' command, but you can set a hook on `stop'.\n\
9057 This allows you to set a list of commands to be run each time execution\n\
9058 of the program stops."), &cmdlist);
9060 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9061 Set inferior debugging."), _("\
9062 Show inferior debugging."), _("\
9063 When non-zero, inferior specific debugging is enabled."),
9066 &setdebuglist, &showdebuglist);
9068 add_setshow_boolean_cmd ("displaced", class_maintenance,
9069 &debug_displaced, _("\
9070 Set displaced stepping debugging."), _("\
9071 Show displaced stepping debugging."), _("\
9072 When non-zero, displaced stepping specific debugging is enabled."),
9074 show_debug_displaced,
9075 &setdebuglist, &showdebuglist);
9077 add_setshow_boolean_cmd ("non-stop", no_class,
9079 Set whether gdb controls the inferior in non-stop mode."), _("\
9080 Show whether gdb controls the inferior in non-stop mode."), _("\
9081 When debugging a multi-threaded program and this setting is\n\
9082 off (the default, also called all-stop mode), when one thread stops\n\
9083 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9084 all other threads in the program while you interact with the thread of\n\
9085 interest. When you continue or step a thread, you can allow the other\n\
9086 threads to run, or have them remain stopped, but while you inspect any\n\
9087 thread's state, all threads stop.\n\
9089 In non-stop mode, when one thread stops, other threads can continue\n\
9090 to run freely. You'll be able to step each thread independently,\n\
9091 leave it stopped or free to run as needed."),
9097 numsigs = (int) GDB_SIGNAL_LAST;
9098 signal_stop = XNEWVEC (unsigned char, numsigs);
9099 signal_print = XNEWVEC (unsigned char, numsigs);
9100 signal_program = XNEWVEC (unsigned char, numsigs);
9101 signal_catch = XNEWVEC (unsigned char, numsigs);
9102 signal_pass = XNEWVEC (unsigned char, numsigs);
9103 for (i = 0; i < numsigs; i++)
9106 signal_print[i] = 1;
9107 signal_program[i] = 1;
9108 signal_catch[i] = 0;
9111 /* Signals caused by debugger's own actions should not be given to
9112 the program afterwards.
9114 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9115 explicitly specifies that it should be delivered to the target
9116 program. Typically, that would occur when a user is debugging a
9117 target monitor on a simulator: the target monitor sets a
9118 breakpoint; the simulator encounters this breakpoint and halts
9119 the simulation handing control to GDB; GDB, noting that the stop
9120 address doesn't map to any known breakpoint, returns control back
9121 to the simulator; the simulator then delivers the hardware
9122 equivalent of a GDB_SIGNAL_TRAP to the program being
9124 signal_program[GDB_SIGNAL_TRAP] = 0;
9125 signal_program[GDB_SIGNAL_INT] = 0;
9127 /* Signals that are not errors should not normally enter the debugger. */
9128 signal_stop[GDB_SIGNAL_ALRM] = 0;
9129 signal_print[GDB_SIGNAL_ALRM] = 0;
9130 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9131 signal_print[GDB_SIGNAL_VTALRM] = 0;
9132 signal_stop[GDB_SIGNAL_PROF] = 0;
9133 signal_print[GDB_SIGNAL_PROF] = 0;
9134 signal_stop[GDB_SIGNAL_CHLD] = 0;
9135 signal_print[GDB_SIGNAL_CHLD] = 0;
9136 signal_stop[GDB_SIGNAL_IO] = 0;
9137 signal_print[GDB_SIGNAL_IO] = 0;
9138 signal_stop[GDB_SIGNAL_POLL] = 0;
9139 signal_print[GDB_SIGNAL_POLL] = 0;
9140 signal_stop[GDB_SIGNAL_URG] = 0;
9141 signal_print[GDB_SIGNAL_URG] = 0;
9142 signal_stop[GDB_SIGNAL_WINCH] = 0;
9143 signal_print[GDB_SIGNAL_WINCH] = 0;
9144 signal_stop[GDB_SIGNAL_PRIO] = 0;
9145 signal_print[GDB_SIGNAL_PRIO] = 0;
9147 /* These signals are used internally by user-level thread
9148 implementations. (See signal(5) on Solaris.) Like the above
9149 signals, a healthy program receives and handles them as part of
9150 its normal operation. */
9151 signal_stop[GDB_SIGNAL_LWP] = 0;
9152 signal_print[GDB_SIGNAL_LWP] = 0;
9153 signal_stop[GDB_SIGNAL_WAITING] = 0;
9154 signal_print[GDB_SIGNAL_WAITING] = 0;
9155 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9156 signal_print[GDB_SIGNAL_CANCEL] = 0;
9158 /* Update cached state. */
9159 signal_cache_update (-1);
9161 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9162 &stop_on_solib_events, _("\
9163 Set stopping for shared library events."), _("\
9164 Show stopping for shared library events."), _("\
9165 If nonzero, gdb will give control to the user when the dynamic linker\n\
9166 notifies gdb of shared library events. The most common event of interest\n\
9167 to the user would be loading/unloading of a new library."),
9168 set_stop_on_solib_events,
9169 show_stop_on_solib_events,
9170 &setlist, &showlist);
9172 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9173 follow_fork_mode_kind_names,
9174 &follow_fork_mode_string, _("\
9175 Set debugger response to a program call of fork or vfork."), _("\
9176 Show debugger response to a program call of fork or vfork."), _("\
9177 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9178 parent - the original process is debugged after a fork\n\
9179 child - the new process is debugged after a fork\n\
9180 The unfollowed process will continue to run.\n\
9181 By default, the debugger will follow the parent process."),
9183 show_follow_fork_mode_string,
9184 &setlist, &showlist);
9186 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9187 follow_exec_mode_names,
9188 &follow_exec_mode_string, _("\
9189 Set debugger response to a program call of exec."), _("\
9190 Show debugger response to a program call of exec."), _("\
9191 An exec call replaces the program image of a process.\n\
9193 follow-exec-mode can be:\n\
9195 new - the debugger creates a new inferior and rebinds the process\n\
9196 to this new inferior. The program the process was running before\n\
9197 the exec call can be restarted afterwards by restarting the original\n\
9200 same - the debugger keeps the process bound to the same inferior.\n\
9201 The new executable image replaces the previous executable loaded in\n\
9202 the inferior. Restarting the inferior after the exec call restarts\n\
9203 the executable the process was running after the exec call.\n\
9205 By default, the debugger will use the same inferior."),
9207 show_follow_exec_mode_string,
9208 &setlist, &showlist);
9210 add_setshow_enum_cmd ("scheduler-locking", class_run,
9211 scheduler_enums, &scheduler_mode, _("\
9212 Set mode for locking scheduler during execution."), _("\
9213 Show mode for locking scheduler during execution."), _("\
9214 off == no locking (threads may preempt at any time)\n\
9215 on == full locking (no thread except the current thread may run)\n\
9216 This applies to both normal execution and replay mode.\n\
9217 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9218 In this mode, other threads may run during other commands.\n\
9219 This applies to both normal execution and replay mode.\n\
9220 replay == scheduler locked in replay mode and unlocked during normal execution."),
9221 set_schedlock_func, /* traps on target vector */
9222 show_scheduler_mode,
9223 &setlist, &showlist);
9225 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9226 Set mode for resuming threads of all processes."), _("\
9227 Show mode for resuming threads of all processes."), _("\
9228 When on, execution commands (such as 'continue' or 'next') resume all\n\
9229 threads of all processes. When off (which is the default), execution\n\
9230 commands only resume the threads of the current process. The set of\n\
9231 threads that are resumed is further refined by the scheduler-locking\n\
9232 mode (see help set scheduler-locking)."),
9234 show_schedule_multiple,
9235 &setlist, &showlist);
9237 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9238 Set mode of the step operation."), _("\
9239 Show mode of the step operation."), _("\
9240 When set, doing a step over a function without debug line information\n\
9241 will stop at the first instruction of that function. Otherwise, the\n\
9242 function is skipped and the step command stops at a different source line."),
9244 show_step_stop_if_no_debug,
9245 &setlist, &showlist);
9247 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9248 &can_use_displaced_stepping, _("\
9249 Set debugger's willingness to use displaced stepping."), _("\
9250 Show debugger's willingness to use displaced stepping."), _("\
9251 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9252 supported by the target architecture. If off, gdb will not use displaced\n\
9253 stepping to step over breakpoints, even if such is supported by the target\n\
9254 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9255 if the target architecture supports it and non-stop mode is active, but will not\n\
9256 use it in all-stop mode (see help set non-stop)."),
9258 show_can_use_displaced_stepping,
9259 &setlist, &showlist);
9261 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9262 &exec_direction, _("Set direction of execution.\n\
9263 Options are 'forward' or 'reverse'."),
9264 _("Show direction of execution (forward/reverse)."),
9265 _("Tells gdb whether to execute forward or backward."),
9266 set_exec_direction_func, show_exec_direction_func,
9267 &setlist, &showlist);
9269 /* Set/show detach-on-fork: user-settable mode. */
9271 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9272 Set whether gdb will detach the child of a fork."), _("\
9273 Show whether gdb will detach the child of a fork."), _("\
9274 Tells gdb whether to detach the child of a fork."),
9275 NULL, NULL, &setlist, &showlist);
9277 /* Set/show disable address space randomization mode. */
9279 add_setshow_boolean_cmd ("disable-randomization", class_support,
9280 &disable_randomization, _("\
9281 Set disabling of debuggee's virtual address space randomization."), _("\
9282 Show disabling of debuggee's virtual address space randomization."), _("\
9283 When this mode is on (which is the default), randomization of the virtual\n\
9284 address space is disabled. Standalone programs run with the randomization\n\
9285 enabled by default on some platforms."),
9286 &set_disable_randomization,
9287 &show_disable_randomization,
9288 &setlist, &showlist);
9290 /* ptid initializations */
9291 inferior_ptid = null_ptid;
9292 target_last_wait_ptid = minus_one_ptid;
9294 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9295 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9296 observer_attach_thread_exit (infrun_thread_thread_exit);
9297 observer_attach_inferior_exit (infrun_inferior_exit);
9299 /* Explicitly create without lookup, since that tries to create a
9300 value with a void typed value, and when we get here, gdbarch
9301 isn't initialized yet. At this point, we're quite sure there
9302 isn't another convenience variable of the same name. */
9303 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9305 add_setshow_boolean_cmd ("observer", no_class,
9306 &observer_mode_1, _("\
9307 Set whether gdb controls the inferior in observer mode."), _("\
9308 Show whether gdb controls the inferior in observer mode."), _("\
9309 In observer mode, GDB can get data from the inferior, but not\n\
9310 affect its execution. Registers and memory may not be changed,\n\
9311 breakpoints may not be set, and the program cannot be interrupted\n\