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 = (char *) 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
1696 = (struct displaced_step_inferior_state *) arg;
1698 displaced_step_clear (state);
1701 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1703 displaced_step_dump_bytes (struct ui_file *file,
1704 const gdb_byte *buf,
1709 for (i = 0; i < len; i++)
1710 fprintf_unfiltered (file, "%02x ", buf[i]);
1711 fputs_unfiltered ("\n", file);
1714 /* Prepare to single-step, using displaced stepping.
1716 Note that we cannot use displaced stepping when we have a signal to
1717 deliver. If we have a signal to deliver and an instruction to step
1718 over, then after the step, there will be no indication from the
1719 target whether the thread entered a signal handler or ignored the
1720 signal and stepped over the instruction successfully --- both cases
1721 result in a simple SIGTRAP. In the first case we mustn't do a
1722 fixup, and in the second case we must --- but we can't tell which.
1723 Comments in the code for 'random signals' in handle_inferior_event
1724 explain how we handle this case instead.
1726 Returns 1 if preparing was successful -- this thread is going to be
1727 stepped now; 0 if displaced stepping this thread got queued; or -1
1728 if this instruction can't be displaced stepped. */
1731 displaced_step_prepare_throw (ptid_t ptid)
1733 struct cleanup *old_cleanups, *ignore_cleanups;
1734 struct thread_info *tp = find_thread_ptid (ptid);
1735 struct regcache *regcache = get_thread_regcache (ptid);
1736 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1737 CORE_ADDR original, copy;
1739 struct displaced_step_closure *closure;
1740 struct displaced_step_inferior_state *displaced;
1743 /* We should never reach this function if the architecture does not
1744 support displaced stepping. */
1745 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1747 /* Nor if the thread isn't meant to step over a breakpoint. */
1748 gdb_assert (tp->control.trap_expected);
1750 /* Disable range stepping while executing in the scratch pad. We
1751 want a single-step even if executing the displaced instruction in
1752 the scratch buffer lands within the stepping range (e.g., a
1754 tp->control.may_range_step = 0;
1756 /* We have to displaced step one thread at a time, as we only have
1757 access to a single scratch space per inferior. */
1759 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1761 if (!ptid_equal (displaced->step_ptid, null_ptid))
1763 /* Already waiting for a displaced step to finish. Defer this
1764 request and place in queue. */
1766 if (debug_displaced)
1767 fprintf_unfiltered (gdb_stdlog,
1768 "displaced: deferring step of %s\n",
1769 target_pid_to_str (ptid));
1771 thread_step_over_chain_enqueue (tp);
1776 if (debug_displaced)
1777 fprintf_unfiltered (gdb_stdlog,
1778 "displaced: stepping %s now\n",
1779 target_pid_to_str (ptid));
1782 displaced_step_clear (displaced);
1784 old_cleanups = save_inferior_ptid ();
1785 inferior_ptid = ptid;
1787 original = regcache_read_pc (regcache);
1789 copy = gdbarch_displaced_step_location (gdbarch);
1790 len = gdbarch_max_insn_length (gdbarch);
1792 /* Save the original contents of the copy area. */
1793 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1794 ignore_cleanups = make_cleanup (free_current_contents,
1795 &displaced->step_saved_copy);
1796 status = target_read_memory (copy, displaced->step_saved_copy, len);
1798 throw_error (MEMORY_ERROR,
1799 _("Error accessing memory address %s (%s) for "
1800 "displaced-stepping scratch space."),
1801 paddress (gdbarch, copy), safe_strerror (status));
1802 if (debug_displaced)
1804 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1805 paddress (gdbarch, copy));
1806 displaced_step_dump_bytes (gdb_stdlog,
1807 displaced->step_saved_copy,
1811 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1812 original, copy, regcache);
1813 if (closure == NULL)
1815 /* The architecture doesn't know how or want to displaced step
1816 this instruction or instruction sequence. Fallback to
1817 stepping over the breakpoint in-line. */
1818 do_cleanups (old_cleanups);
1822 /* Save the information we need to fix things up if the step
1824 displaced->step_ptid = ptid;
1825 displaced->step_gdbarch = gdbarch;
1826 displaced->step_closure = closure;
1827 displaced->step_original = original;
1828 displaced->step_copy = copy;
1830 make_cleanup (displaced_step_clear_cleanup, displaced);
1832 /* Resume execution at the copy. */
1833 regcache_write_pc (regcache, copy);
1835 discard_cleanups (ignore_cleanups);
1837 do_cleanups (old_cleanups);
1839 if (debug_displaced)
1840 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1841 paddress (gdbarch, copy));
1846 /* Wrapper for displaced_step_prepare_throw that disabled further
1847 attempts at displaced stepping if we get a memory error. */
1850 displaced_step_prepare (ptid_t ptid)
1856 prepared = displaced_step_prepare_throw (ptid);
1858 CATCH (ex, RETURN_MASK_ERROR)
1860 struct displaced_step_inferior_state *displaced_state;
1862 if (ex.error != MEMORY_ERROR)
1863 throw_exception (ex);
1867 fprintf_unfiltered (gdb_stdlog,
1868 "infrun: disabling displaced stepping: %s\n",
1872 /* Be verbose if "set displaced-stepping" is "on", silent if
1874 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1876 warning (_("disabling displaced stepping: %s"),
1880 /* Disable further displaced stepping attempts. */
1882 = get_displaced_stepping_state (ptid_get_pid (ptid));
1883 displaced_state->failed_before = 1;
1891 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1892 const gdb_byte *myaddr, int len)
1894 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1896 inferior_ptid = ptid;
1897 write_memory (memaddr, myaddr, len);
1898 do_cleanups (ptid_cleanup);
1901 /* Restore the contents of the copy area for thread PTID. */
1904 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1907 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1909 write_memory_ptid (ptid, displaced->step_copy,
1910 displaced->step_saved_copy, len);
1911 if (debug_displaced)
1912 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1913 target_pid_to_str (ptid),
1914 paddress (displaced->step_gdbarch,
1915 displaced->step_copy));
1918 /* If we displaced stepped an instruction successfully, adjust
1919 registers and memory to yield the same effect the instruction would
1920 have had if we had executed it at its original address, and return
1921 1. If the instruction didn't complete, relocate the PC and return
1922 -1. If the thread wasn't displaced stepping, return 0. */
1925 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1927 struct cleanup *old_cleanups;
1928 struct displaced_step_inferior_state *displaced
1929 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1932 /* Was any thread of this process doing a displaced step? */
1933 if (displaced == NULL)
1936 /* Was this event for the pid we displaced? */
1937 if (ptid_equal (displaced->step_ptid, null_ptid)
1938 || ! ptid_equal (displaced->step_ptid, event_ptid))
1941 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1943 displaced_step_restore (displaced, displaced->step_ptid);
1945 /* Fixup may need to read memory/registers. Switch to the thread
1946 that we're fixing up. Also, target_stopped_by_watchpoint checks
1947 the current thread. */
1948 switch_to_thread (event_ptid);
1950 /* Did the instruction complete successfully? */
1951 if (signal == GDB_SIGNAL_TRAP
1952 && !(target_stopped_by_watchpoint ()
1953 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1954 || target_have_steppable_watchpoint)))
1956 /* Fix up the resulting state. */
1957 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1958 displaced->step_closure,
1959 displaced->step_original,
1960 displaced->step_copy,
1961 get_thread_regcache (displaced->step_ptid));
1966 /* Since the instruction didn't complete, all we can do is
1968 struct regcache *regcache = get_thread_regcache (event_ptid);
1969 CORE_ADDR pc = regcache_read_pc (regcache);
1971 pc = displaced->step_original + (pc - displaced->step_copy);
1972 regcache_write_pc (regcache, pc);
1976 do_cleanups (old_cleanups);
1978 displaced->step_ptid = null_ptid;
1983 /* Data to be passed around while handling an event. This data is
1984 discarded between events. */
1985 struct execution_control_state
1988 /* The thread that got the event, if this was a thread event; NULL
1990 struct thread_info *event_thread;
1992 struct target_waitstatus ws;
1993 int stop_func_filled_in;
1994 CORE_ADDR stop_func_start;
1995 CORE_ADDR stop_func_end;
1996 const char *stop_func_name;
1999 /* True if the event thread hit the single-step breakpoint of
2000 another thread. Thus the event doesn't cause a stop, the thread
2001 needs to be single-stepped past the single-step breakpoint before
2002 we can switch back to the original stepping thread. */
2003 int hit_singlestep_breakpoint;
2006 /* Clear ECS and set it to point at TP. */
2009 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2011 memset (ecs, 0, sizeof (*ecs));
2012 ecs->event_thread = tp;
2013 ecs->ptid = tp->ptid;
2016 static void keep_going_pass_signal (struct execution_control_state *ecs);
2017 static void prepare_to_wait (struct execution_control_state *ecs);
2018 static int keep_going_stepped_thread (struct thread_info *tp);
2019 static int thread_still_needs_step_over (struct thread_info *tp);
2020 static void stop_all_threads (void);
2022 /* Are there any pending step-over requests? If so, run all we can
2023 now and return true. Otherwise, return false. */
2026 start_step_over (void)
2028 struct thread_info *tp, *next;
2030 /* Don't start a new step-over if we already have an in-line
2031 step-over operation ongoing. */
2032 if (step_over_info_valid_p ())
2035 for (tp = step_over_queue_head; tp != NULL; tp = next)
2037 struct execution_control_state ecss;
2038 struct execution_control_state *ecs = &ecss;
2039 enum step_over_what step_what;
2040 int must_be_in_line;
2042 next = thread_step_over_chain_next (tp);
2044 /* If this inferior already has a displaced step in process,
2045 don't start a new one. */
2046 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2049 step_what = thread_still_needs_step_over (tp);
2050 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2051 || ((step_what & STEP_OVER_BREAKPOINT)
2052 && !use_displaced_stepping (tp)));
2054 /* We currently stop all threads of all processes to step-over
2055 in-line. If we need to start a new in-line step-over, let
2056 any pending displaced steps finish first. */
2057 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2060 thread_step_over_chain_remove (tp);
2062 if (step_over_queue_head == NULL)
2065 fprintf_unfiltered (gdb_stdlog,
2066 "infrun: step-over queue now empty\n");
2069 if (tp->control.trap_expected
2073 internal_error (__FILE__, __LINE__,
2074 "[%s] has inconsistent state: "
2075 "trap_expected=%d, resumed=%d, executing=%d\n",
2076 target_pid_to_str (tp->ptid),
2077 tp->control.trap_expected,
2083 fprintf_unfiltered (gdb_stdlog,
2084 "infrun: resuming [%s] for step-over\n",
2085 target_pid_to_str (tp->ptid));
2087 /* keep_going_pass_signal skips the step-over if the breakpoint
2088 is no longer inserted. In all-stop, we want to keep looking
2089 for a thread that needs a step-over instead of resuming TP,
2090 because we wouldn't be able to resume anything else until the
2091 target stops again. In non-stop, the resume always resumes
2092 only TP, so it's OK to let the thread resume freely. */
2093 if (!target_is_non_stop_p () && !step_what)
2096 switch_to_thread (tp->ptid);
2097 reset_ecs (ecs, tp);
2098 keep_going_pass_signal (ecs);
2100 if (!ecs->wait_some_more)
2101 error (_("Command aborted."));
2103 gdb_assert (tp->resumed);
2105 /* If we started a new in-line step-over, we're done. */
2106 if (step_over_info_valid_p ())
2108 gdb_assert (tp->control.trap_expected);
2112 if (!target_is_non_stop_p ())
2114 /* On all-stop, shouldn't have resumed unless we needed a
2116 gdb_assert (tp->control.trap_expected
2117 || tp->step_after_step_resume_breakpoint);
2119 /* With remote targets (at least), in all-stop, we can't
2120 issue any further remote commands until the program stops
2125 /* Either the thread no longer needed a step-over, or a new
2126 displaced stepping sequence started. Even in the latter
2127 case, continue looking. Maybe we can also start another
2128 displaced step on a thread of other process. */
2134 /* Update global variables holding ptids to hold NEW_PTID if they were
2135 holding OLD_PTID. */
2137 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2139 struct displaced_step_request *it;
2140 struct displaced_step_inferior_state *displaced;
2142 if (ptid_equal (inferior_ptid, old_ptid))
2143 inferior_ptid = new_ptid;
2145 for (displaced = displaced_step_inferior_states;
2147 displaced = displaced->next)
2149 if (ptid_equal (displaced->step_ptid, old_ptid))
2150 displaced->step_ptid = new_ptid;
2157 /* Things to clean up if we QUIT out of resume (). */
2159 resume_cleanups (void *ignore)
2161 if (!ptid_equal (inferior_ptid, null_ptid))
2162 delete_single_step_breakpoints (inferior_thread ());
2167 static const char schedlock_off[] = "off";
2168 static const char schedlock_on[] = "on";
2169 static const char schedlock_step[] = "step";
2170 static const char schedlock_replay[] = "replay";
2171 static const char *const scheduler_enums[] = {
2178 static const char *scheduler_mode = schedlock_replay;
2180 show_scheduler_mode (struct ui_file *file, int from_tty,
2181 struct cmd_list_element *c, const char *value)
2183 fprintf_filtered (file,
2184 _("Mode for locking scheduler "
2185 "during execution is \"%s\".\n"),
2190 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2192 if (!target_can_lock_scheduler)
2194 scheduler_mode = schedlock_off;
2195 error (_("Target '%s' cannot support this command."), target_shortname);
2199 /* True if execution commands resume all threads of all processes by
2200 default; otherwise, resume only threads of the current inferior
2202 int sched_multi = 0;
2204 /* Try to setup for software single stepping over the specified location.
2205 Return 1 if target_resume() should use hardware single step.
2207 GDBARCH the current gdbarch.
2208 PC the location to step over. */
2211 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2215 if (execution_direction == EXEC_FORWARD
2216 && gdbarch_software_single_step_p (gdbarch)
2217 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
2227 user_visible_resume_ptid (int step)
2233 /* With non-stop mode on, threads are always handled
2235 resume_ptid = inferior_ptid;
2237 else if ((scheduler_mode == schedlock_on)
2238 || (scheduler_mode == schedlock_step && step))
2240 /* User-settable 'scheduler' mode requires solo thread
2242 resume_ptid = inferior_ptid;
2244 else if ((scheduler_mode == schedlock_replay)
2245 && target_record_will_replay (minus_one_ptid, execution_direction))
2247 /* User-settable 'scheduler' mode requires solo thread resume in replay
2249 resume_ptid = inferior_ptid;
2251 else if (!sched_multi && target_supports_multi_process ())
2253 /* Resume all threads of the current process (and none of other
2255 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2259 /* Resume all threads of all processes. */
2260 resume_ptid = RESUME_ALL;
2266 /* Return a ptid representing the set of threads that we will resume,
2267 in the perspective of the target, assuming run control handling
2268 does not require leaving some threads stopped (e.g., stepping past
2269 breakpoint). USER_STEP indicates whether we're about to start the
2270 target for a stepping command. */
2273 internal_resume_ptid (int user_step)
2275 /* In non-stop, we always control threads individually. Note that
2276 the target may always work in non-stop mode even with "set
2277 non-stop off", in which case user_visible_resume_ptid could
2278 return a wildcard ptid. */
2279 if (target_is_non_stop_p ())
2280 return inferior_ptid;
2282 return user_visible_resume_ptid (user_step);
2285 /* Wrapper for target_resume, that handles infrun-specific
2289 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2291 struct thread_info *tp = inferior_thread ();
2293 /* Install inferior's terminal modes. */
2294 target_terminal_inferior ();
2296 /* Avoid confusing the next resume, if the next stop/resume
2297 happens to apply to another thread. */
2298 tp->suspend.stop_signal = GDB_SIGNAL_0;
2300 /* Advise target which signals may be handled silently.
2302 If we have removed breakpoints because we are stepping over one
2303 in-line (in any thread), we need to receive all signals to avoid
2304 accidentally skipping a breakpoint during execution of a signal
2307 Likewise if we're displaced stepping, otherwise a trap for a
2308 breakpoint in a signal handler might be confused with the
2309 displaced step finishing. We don't make the displaced_step_fixup
2310 step distinguish the cases instead, because:
2312 - a backtrace while stopped in the signal handler would show the
2313 scratch pad as frame older than the signal handler, instead of
2314 the real mainline code.
2316 - when the thread is later resumed, the signal handler would
2317 return to the scratch pad area, which would no longer be
2319 if (step_over_info_valid_p ()
2320 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2321 target_pass_signals (0, NULL);
2323 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2325 target_resume (resume_ptid, step, sig);
2328 /* Resume the inferior, but allow a QUIT. This is useful if the user
2329 wants to interrupt some lengthy single-stepping operation
2330 (for child processes, the SIGINT goes to the inferior, and so
2331 we get a SIGINT random_signal, but for remote debugging and perhaps
2332 other targets, that's not true).
2334 SIG is the signal to give the inferior (zero for none). */
2336 resume (enum gdb_signal sig)
2338 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2339 struct regcache *regcache = get_current_regcache ();
2340 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2341 struct thread_info *tp = inferior_thread ();
2342 CORE_ADDR pc = regcache_read_pc (regcache);
2343 struct address_space *aspace = get_regcache_aspace (regcache);
2345 /* This represents the user's step vs continue request. When
2346 deciding whether "set scheduler-locking step" applies, it's the
2347 user's intention that counts. */
2348 const int user_step = tp->control.stepping_command;
2349 /* This represents what we'll actually request the target to do.
2350 This can decay from a step to a continue, if e.g., we need to
2351 implement single-stepping with breakpoints (software
2355 gdb_assert (!thread_is_in_step_over_chain (tp));
2359 if (tp->suspend.waitstatus_pending_p)
2365 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2366 fprintf_unfiltered (gdb_stdlog,
2367 "infrun: resume: thread %s has pending wait status %s "
2368 "(currently_stepping=%d).\n",
2369 target_pid_to_str (tp->ptid), statstr,
2370 currently_stepping (tp));
2376 /* FIXME: What should we do if we are supposed to resume this
2377 thread with a signal? Maybe we should maintain a queue of
2378 pending signals to deliver. */
2379 if (sig != GDB_SIGNAL_0)
2381 warning (_("Couldn't deliver signal %s to %s."),
2382 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2385 tp->suspend.stop_signal = GDB_SIGNAL_0;
2386 discard_cleanups (old_cleanups);
2388 if (target_can_async_p ())
2393 tp->stepped_breakpoint = 0;
2395 /* Depends on stepped_breakpoint. */
2396 step = currently_stepping (tp);
2398 if (current_inferior ()->waiting_for_vfork_done)
2400 /* Don't try to single-step a vfork parent that is waiting for
2401 the child to get out of the shared memory region (by exec'ing
2402 or exiting). This is particularly important on software
2403 single-step archs, as the child process would trip on the
2404 software single step breakpoint inserted for the parent
2405 process. Since the parent will not actually execute any
2406 instruction until the child is out of the shared region (such
2407 are vfork's semantics), it is safe to simply continue it.
2408 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2409 the parent, and tell it to `keep_going', which automatically
2410 re-sets it stepping. */
2412 fprintf_unfiltered (gdb_stdlog,
2413 "infrun: resume : clear step\n");
2418 fprintf_unfiltered (gdb_stdlog,
2419 "infrun: resume (step=%d, signal=%s), "
2420 "trap_expected=%d, current thread [%s] at %s\n",
2421 step, gdb_signal_to_symbol_string (sig),
2422 tp->control.trap_expected,
2423 target_pid_to_str (inferior_ptid),
2424 paddress (gdbarch, pc));
2426 /* Normally, by the time we reach `resume', the breakpoints are either
2427 removed or inserted, as appropriate. The exception is if we're sitting
2428 at a permanent breakpoint; we need to step over it, but permanent
2429 breakpoints can't be removed. So we have to test for it here. */
2430 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2432 if (sig != GDB_SIGNAL_0)
2434 /* We have a signal to pass to the inferior. The resume
2435 may, or may not take us to the signal handler. If this
2436 is a step, we'll need to stop in the signal handler, if
2437 there's one, (if the target supports stepping into
2438 handlers), or in the next mainline instruction, if
2439 there's no handler. If this is a continue, we need to be
2440 sure to run the handler with all breakpoints inserted.
2441 In all cases, set a breakpoint at the current address
2442 (where the handler returns to), and once that breakpoint
2443 is hit, resume skipping the permanent breakpoint. If
2444 that breakpoint isn't hit, then we've stepped into the
2445 signal handler (or hit some other event). We'll delete
2446 the step-resume breakpoint then. */
2449 fprintf_unfiltered (gdb_stdlog,
2450 "infrun: resume: skipping permanent breakpoint, "
2451 "deliver signal first\n");
2453 clear_step_over_info ();
2454 tp->control.trap_expected = 0;
2456 if (tp->control.step_resume_breakpoint == NULL)
2458 /* Set a "high-priority" step-resume, as we don't want
2459 user breakpoints at PC to trigger (again) when this
2461 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2462 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2464 tp->step_after_step_resume_breakpoint = step;
2467 insert_breakpoints ();
2471 /* There's no signal to pass, we can go ahead and skip the
2472 permanent breakpoint manually. */
2474 fprintf_unfiltered (gdb_stdlog,
2475 "infrun: resume: skipping permanent breakpoint\n");
2476 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2477 /* Update pc to reflect the new address from which we will
2478 execute instructions. */
2479 pc = regcache_read_pc (regcache);
2483 /* We've already advanced the PC, so the stepping part
2484 is done. Now we need to arrange for a trap to be
2485 reported to handle_inferior_event. Set a breakpoint
2486 at the current PC, and run to it. Don't update
2487 prev_pc, because if we end in
2488 switch_back_to_stepped_thread, we want the "expected
2489 thread advanced also" branch to be taken. IOW, we
2490 don't want this thread to step further from PC
2492 gdb_assert (!step_over_info_valid_p ());
2493 insert_single_step_breakpoint (gdbarch, aspace, pc);
2494 insert_breakpoints ();
2496 resume_ptid = internal_resume_ptid (user_step);
2497 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2498 discard_cleanups (old_cleanups);
2505 /* If we have a breakpoint to step over, make sure to do a single
2506 step only. Same if we have software watchpoints. */
2507 if (tp->control.trap_expected || bpstat_should_step ())
2508 tp->control.may_range_step = 0;
2510 /* If enabled, step over breakpoints by executing a copy of the
2511 instruction at a different address.
2513 We can't use displaced stepping when we have a signal to deliver;
2514 the comments for displaced_step_prepare explain why. The
2515 comments in the handle_inferior event for dealing with 'random
2516 signals' explain what we do instead.
2518 We can't use displaced stepping when we are waiting for vfork_done
2519 event, displaced stepping breaks the vfork child similarly as single
2520 step software breakpoint. */
2521 if (tp->control.trap_expected
2522 && use_displaced_stepping (tp)
2523 && !step_over_info_valid_p ()
2524 && sig == GDB_SIGNAL_0
2525 && !current_inferior ()->waiting_for_vfork_done)
2527 int prepared = displaced_step_prepare (inferior_ptid);
2532 fprintf_unfiltered (gdb_stdlog,
2533 "Got placed in step-over queue\n");
2535 tp->control.trap_expected = 0;
2536 discard_cleanups (old_cleanups);
2539 else if (prepared < 0)
2541 /* Fallback to stepping over the breakpoint in-line. */
2543 if (target_is_non_stop_p ())
2544 stop_all_threads ();
2546 set_step_over_info (get_regcache_aspace (regcache),
2547 regcache_read_pc (regcache), 0);
2549 step = maybe_software_singlestep (gdbarch, pc);
2551 insert_breakpoints ();
2553 else if (prepared > 0)
2555 struct displaced_step_inferior_state *displaced;
2557 /* Update pc to reflect the new address from which we will
2558 execute instructions due to displaced stepping. */
2559 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2561 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2562 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2563 displaced->step_closure);
2567 /* Do we need to do it the hard way, w/temp breakpoints? */
2569 step = maybe_software_singlestep (gdbarch, pc);
2571 /* Currently, our software single-step implementation leads to different
2572 results than hardware single-stepping in one situation: when stepping
2573 into delivering a signal which has an associated signal handler,
2574 hardware single-step will stop at the first instruction of the handler,
2575 while software single-step will simply skip execution of the handler.
2577 For now, this difference in behavior is accepted since there is no
2578 easy way to actually implement single-stepping into a signal handler
2579 without kernel support.
2581 However, there is one scenario where this difference leads to follow-on
2582 problems: if we're stepping off a breakpoint by removing all breakpoints
2583 and then single-stepping. In this case, the software single-step
2584 behavior means that even if there is a *breakpoint* in the signal
2585 handler, GDB still would not stop.
2587 Fortunately, we can at least fix this particular issue. We detect
2588 here the case where we are about to deliver a signal while software
2589 single-stepping with breakpoints removed. In this situation, we
2590 revert the decisions to remove all breakpoints and insert single-
2591 step breakpoints, and instead we install a step-resume breakpoint
2592 at the current address, deliver the signal without stepping, and
2593 once we arrive back at the step-resume breakpoint, actually step
2594 over the breakpoint we originally wanted to step over. */
2595 if (thread_has_single_step_breakpoints_set (tp)
2596 && sig != GDB_SIGNAL_0
2597 && step_over_info_valid_p ())
2599 /* If we have nested signals or a pending signal is delivered
2600 immediately after a handler returns, might might already have
2601 a step-resume breakpoint set on the earlier handler. We cannot
2602 set another step-resume breakpoint; just continue on until the
2603 original breakpoint is hit. */
2604 if (tp->control.step_resume_breakpoint == NULL)
2606 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2607 tp->step_after_step_resume_breakpoint = 1;
2610 delete_single_step_breakpoints (tp);
2612 clear_step_over_info ();
2613 tp->control.trap_expected = 0;
2615 insert_breakpoints ();
2618 /* If STEP is set, it's a request to use hardware stepping
2619 facilities. But in that case, we should never
2620 use singlestep breakpoint. */
2621 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2623 /* Decide the set of threads to ask the target to resume. */
2624 if ((step || thread_has_single_step_breakpoints_set (tp))
2625 && tp->control.trap_expected)
2627 /* We're allowing a thread to run past a breakpoint it has
2628 hit, by single-stepping the thread with the breakpoint
2629 removed. In which case, we need to single-step only this
2630 thread, and keep others stopped, as they can miss this
2631 breakpoint if allowed to run. */
2632 resume_ptid = inferior_ptid;
2635 resume_ptid = internal_resume_ptid (user_step);
2637 if (execution_direction != EXEC_REVERSE
2638 && step && breakpoint_inserted_here_p (aspace, pc))
2640 /* There are two cases where we currently need to step a
2641 breakpoint instruction when we have a signal to deliver:
2643 - See handle_signal_stop where we handle random signals that
2644 could take out us out of the stepping range. Normally, in
2645 that case we end up continuing (instead of stepping) over the
2646 signal handler with a breakpoint at PC, but there are cases
2647 where we should _always_ single-step, even if we have a
2648 step-resume breakpoint, like when a software watchpoint is
2649 set. Assuming single-stepping and delivering a signal at the
2650 same time would takes us to the signal handler, then we could
2651 have removed the breakpoint at PC to step over it. However,
2652 some hardware step targets (like e.g., Mac OS) can't step
2653 into signal handlers, and for those, we need to leave the
2654 breakpoint at PC inserted, as otherwise if the handler
2655 recurses and executes PC again, it'll miss the breakpoint.
2656 So we leave the breakpoint inserted anyway, but we need to
2657 record that we tried to step a breakpoint instruction, so
2658 that adjust_pc_after_break doesn't end up confused.
2660 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2661 in one thread after another thread that was stepping had been
2662 momentarily paused for a step-over. When we re-resume the
2663 stepping thread, it may be resumed from that address with a
2664 breakpoint that hasn't trapped yet. Seen with
2665 gdb.threads/non-stop-fair-events.exp, on targets that don't
2666 do displaced stepping. */
2669 fprintf_unfiltered (gdb_stdlog,
2670 "infrun: resume: [%s] stepped breakpoint\n",
2671 target_pid_to_str (tp->ptid));
2673 tp->stepped_breakpoint = 1;
2675 /* Most targets can step a breakpoint instruction, thus
2676 executing it normally. But if this one cannot, just
2677 continue and we will hit it anyway. */
2678 if (gdbarch_cannot_step_breakpoint (gdbarch))
2683 && tp->control.trap_expected
2684 && use_displaced_stepping (tp)
2685 && !step_over_info_valid_p ())
2687 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2688 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2689 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2692 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2693 paddress (resume_gdbarch, actual_pc));
2694 read_memory (actual_pc, buf, sizeof (buf));
2695 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2698 if (tp->control.may_range_step)
2700 /* If we're resuming a thread with the PC out of the step
2701 range, then we're doing some nested/finer run control
2702 operation, like stepping the thread out of the dynamic
2703 linker or the displaced stepping scratch pad. We
2704 shouldn't have allowed a range step then. */
2705 gdb_assert (pc_in_thread_step_range (pc, tp));
2708 do_target_resume (resume_ptid, step, sig);
2710 discard_cleanups (old_cleanups);
2717 /* Counter that tracks number of user visible stops. This can be used
2718 to tell whether a command has proceeded the inferior past the
2719 current location. This allows e.g., inferior function calls in
2720 breakpoint commands to not interrupt the command list. When the
2721 call finishes successfully, the inferior is standing at the same
2722 breakpoint as if nothing happened (and so we don't call
2724 static ULONGEST current_stop_id;
2731 return current_stop_id;
2734 /* Called when we report a user visible stop. */
2742 /* Clear out all variables saying what to do when inferior is continued.
2743 First do this, then set the ones you want, then call `proceed'. */
2746 clear_proceed_status_thread (struct thread_info *tp)
2749 fprintf_unfiltered (gdb_stdlog,
2750 "infrun: clear_proceed_status_thread (%s)\n",
2751 target_pid_to_str (tp->ptid));
2753 /* If we're starting a new sequence, then the previous finished
2754 single-step is no longer relevant. */
2755 if (tp->suspend.waitstatus_pending_p)
2757 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2760 fprintf_unfiltered (gdb_stdlog,
2761 "infrun: clear_proceed_status: pending "
2762 "event of %s was a finished step. "
2764 target_pid_to_str (tp->ptid));
2766 tp->suspend.waitstatus_pending_p = 0;
2767 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2769 else if (debug_infrun)
2773 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2774 fprintf_unfiltered (gdb_stdlog,
2775 "infrun: clear_proceed_status_thread: thread %s "
2776 "has pending wait status %s "
2777 "(currently_stepping=%d).\n",
2778 target_pid_to_str (tp->ptid), statstr,
2779 currently_stepping (tp));
2784 /* If this signal should not be seen by program, give it zero.
2785 Used for debugging signals. */
2786 if (!signal_pass_state (tp->suspend.stop_signal))
2787 tp->suspend.stop_signal = GDB_SIGNAL_0;
2789 thread_fsm_delete (tp->thread_fsm);
2790 tp->thread_fsm = NULL;
2792 tp->control.trap_expected = 0;
2793 tp->control.step_range_start = 0;
2794 tp->control.step_range_end = 0;
2795 tp->control.may_range_step = 0;
2796 tp->control.step_frame_id = null_frame_id;
2797 tp->control.step_stack_frame_id = null_frame_id;
2798 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2799 tp->control.step_start_function = NULL;
2800 tp->stop_requested = 0;
2802 tp->control.stop_step = 0;
2804 tp->control.proceed_to_finish = 0;
2806 tp->control.command_interp = NULL;
2807 tp->control.stepping_command = 0;
2809 /* Discard any remaining commands or status from previous stop. */
2810 bpstat_clear (&tp->control.stop_bpstat);
2814 clear_proceed_status (int step)
2816 /* With scheduler-locking replay, stop replaying other threads if we're
2817 not replaying the user-visible resume ptid.
2819 This is a convenience feature to not require the user to explicitly
2820 stop replaying the other threads. We're assuming that the user's
2821 intent is to resume tracing the recorded process. */
2822 if (!non_stop && scheduler_mode == schedlock_replay
2823 && target_record_is_replaying (minus_one_ptid)
2824 && !target_record_will_replay (user_visible_resume_ptid (step),
2825 execution_direction))
2826 target_record_stop_replaying ();
2830 struct thread_info *tp;
2833 resume_ptid = user_visible_resume_ptid (step);
2835 /* In all-stop mode, delete the per-thread status of all threads
2836 we're about to resume, implicitly and explicitly. */
2837 ALL_NON_EXITED_THREADS (tp)
2839 if (!ptid_match (tp->ptid, resume_ptid))
2841 clear_proceed_status_thread (tp);
2845 if (!ptid_equal (inferior_ptid, null_ptid))
2847 struct inferior *inferior;
2851 /* If in non-stop mode, only delete the per-thread status of
2852 the current thread. */
2853 clear_proceed_status_thread (inferior_thread ());
2856 inferior = current_inferior ();
2857 inferior->control.stop_soon = NO_STOP_QUIETLY;
2860 stop_after_trap = 0;
2862 observer_notify_about_to_proceed ();
2865 /* Returns true if TP is still stopped at a breakpoint that needs
2866 stepping-over in order to make progress. If the breakpoint is gone
2867 meanwhile, we can skip the whole step-over dance. */
2870 thread_still_needs_step_over_bp (struct thread_info *tp)
2872 if (tp->stepping_over_breakpoint)
2874 struct regcache *regcache = get_thread_regcache (tp->ptid);
2876 if (breakpoint_here_p (get_regcache_aspace (regcache),
2877 regcache_read_pc (regcache))
2878 == ordinary_breakpoint_here)
2881 tp->stepping_over_breakpoint = 0;
2887 /* Check whether thread TP still needs to start a step-over in order
2888 to make progress when resumed. Returns an bitwise or of enum
2889 step_over_what bits, indicating what needs to be stepped over. */
2892 thread_still_needs_step_over (struct thread_info *tp)
2894 struct inferior *inf = find_inferior_ptid (tp->ptid);
2897 if (thread_still_needs_step_over_bp (tp))
2898 what |= STEP_OVER_BREAKPOINT;
2900 if (tp->stepping_over_watchpoint
2901 && !target_have_steppable_watchpoint)
2902 what |= STEP_OVER_WATCHPOINT;
2907 /* Returns true if scheduler locking applies. STEP indicates whether
2908 we're about to do a step/next-like command to a thread. */
2911 schedlock_applies (struct thread_info *tp)
2913 return (scheduler_mode == schedlock_on
2914 || (scheduler_mode == schedlock_step
2915 && tp->control.stepping_command)
2916 || (scheduler_mode == schedlock_replay
2917 && target_record_will_replay (minus_one_ptid,
2918 execution_direction)));
2921 /* Basic routine for continuing the program in various fashions.
2923 ADDR is the address to resume at, or -1 for resume where stopped.
2924 SIGGNAL is the signal to give it, or 0 for none,
2925 or -1 for act according to how it stopped.
2926 STEP is nonzero if should trap after one instruction.
2927 -1 means return after that and print nothing.
2928 You should probably set various step_... variables
2929 before calling here, if you are stepping.
2931 You should call clear_proceed_status before calling proceed. */
2934 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2936 struct regcache *regcache;
2937 struct gdbarch *gdbarch;
2938 struct thread_info *tp;
2940 struct address_space *aspace;
2942 struct execution_control_state ecss;
2943 struct execution_control_state *ecs = &ecss;
2944 struct cleanup *old_chain;
2947 /* If we're stopped at a fork/vfork, follow the branch set by the
2948 "set follow-fork-mode" command; otherwise, we'll just proceed
2949 resuming the current thread. */
2950 if (!follow_fork ())
2952 /* The target for some reason decided not to resume. */
2954 if (target_can_async_p ())
2955 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2959 /* We'll update this if & when we switch to a new thread. */
2960 previous_inferior_ptid = inferior_ptid;
2962 regcache = get_current_regcache ();
2963 gdbarch = get_regcache_arch (regcache);
2964 aspace = get_regcache_aspace (regcache);
2965 pc = regcache_read_pc (regcache);
2966 tp = inferior_thread ();
2968 /* Fill in with reasonable starting values. */
2969 init_thread_stepping_state (tp);
2971 gdb_assert (!thread_is_in_step_over_chain (tp));
2973 if (addr == (CORE_ADDR) -1)
2976 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2977 && execution_direction != EXEC_REVERSE)
2978 /* There is a breakpoint at the address we will resume at,
2979 step one instruction before inserting breakpoints so that
2980 we do not stop right away (and report a second hit at this
2983 Note, we don't do this in reverse, because we won't
2984 actually be executing the breakpoint insn anyway.
2985 We'll be (un-)executing the previous instruction. */
2986 tp->stepping_over_breakpoint = 1;
2987 else if (gdbarch_single_step_through_delay_p (gdbarch)
2988 && gdbarch_single_step_through_delay (gdbarch,
2989 get_current_frame ()))
2990 /* We stepped onto an instruction that needs to be stepped
2991 again before re-inserting the breakpoint, do so. */
2992 tp->stepping_over_breakpoint = 1;
2996 regcache_write_pc (regcache, addr);
2999 if (siggnal != GDB_SIGNAL_DEFAULT)
3000 tp->suspend.stop_signal = siggnal;
3002 /* Record the interpreter that issued the execution command that
3003 caused this thread to resume. If the top level interpreter is
3004 MI/async, and the execution command was a CLI command
3005 (next/step/etc.), we'll want to print stop event output to the MI
3006 console channel (the stepped-to line, etc.), as if the user
3007 entered the execution command on a real GDB console. */
3008 tp->control.command_interp = command_interp ();
3010 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3012 /* If an exception is thrown from this point on, make sure to
3013 propagate GDB's knowledge of the executing state to the
3014 frontend/user running state. */
3015 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
3017 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3018 threads (e.g., we might need to set threads stepping over
3019 breakpoints first), from the user/frontend's point of view, all
3020 threads in RESUME_PTID are now running. Unless we're calling an
3021 inferior function, as in that case we pretend the inferior
3022 doesn't run at all. */
3023 if (!tp->control.in_infcall)
3024 set_running (resume_ptid, 1);
3027 fprintf_unfiltered (gdb_stdlog,
3028 "infrun: proceed (addr=%s, signal=%s)\n",
3029 paddress (gdbarch, addr),
3030 gdb_signal_to_symbol_string (siggnal));
3032 annotate_starting ();
3034 /* Make sure that output from GDB appears before output from the
3036 gdb_flush (gdb_stdout);
3038 /* In a multi-threaded task we may select another thread and
3039 then continue or step.
3041 But if a thread that we're resuming had stopped at a breakpoint,
3042 it will immediately cause another breakpoint stop without any
3043 execution (i.e. it will report a breakpoint hit incorrectly). So
3044 we must step over it first.
3046 Look for threads other than the current (TP) that reported a
3047 breakpoint hit and haven't been resumed yet since. */
3049 /* If scheduler locking applies, we can avoid iterating over all
3051 if (!non_stop && !schedlock_applies (tp))
3053 struct thread_info *current = tp;
3055 ALL_NON_EXITED_THREADS (tp)
3057 /* Ignore the current thread here. It's handled
3062 /* Ignore threads of processes we're not resuming. */
3063 if (!ptid_match (tp->ptid, resume_ptid))
3066 if (!thread_still_needs_step_over (tp))
3069 gdb_assert (!thread_is_in_step_over_chain (tp));
3072 fprintf_unfiltered (gdb_stdlog,
3073 "infrun: need to step-over [%s] first\n",
3074 target_pid_to_str (tp->ptid));
3076 thread_step_over_chain_enqueue (tp);
3082 /* Enqueue the current thread last, so that we move all other
3083 threads over their breakpoints first. */
3084 if (tp->stepping_over_breakpoint)
3085 thread_step_over_chain_enqueue (tp);
3087 /* If the thread isn't started, we'll still need to set its prev_pc,
3088 so that switch_back_to_stepped_thread knows the thread hasn't
3089 advanced. Must do this before resuming any thread, as in
3090 all-stop/remote, once we resume we can't send any other packet
3091 until the target stops again. */
3092 tp->prev_pc = regcache_read_pc (regcache);
3094 started = start_step_over ();
3096 if (step_over_info_valid_p ())
3098 /* Either this thread started a new in-line step over, or some
3099 other thread was already doing one. In either case, don't
3100 resume anything else until the step-over is finished. */
3102 else if (started && !target_is_non_stop_p ())
3104 /* A new displaced stepping sequence was started. In all-stop,
3105 we can't talk to the target anymore until it next stops. */
3107 else if (!non_stop && target_is_non_stop_p ())
3109 /* In all-stop, but the target is always in non-stop mode.
3110 Start all other threads that are implicitly resumed too. */
3111 ALL_NON_EXITED_THREADS (tp)
3113 /* Ignore threads of processes we're not resuming. */
3114 if (!ptid_match (tp->ptid, resume_ptid))
3120 fprintf_unfiltered (gdb_stdlog,
3121 "infrun: proceed: [%s] resumed\n",
3122 target_pid_to_str (tp->ptid));
3123 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3127 if (thread_is_in_step_over_chain (tp))
3130 fprintf_unfiltered (gdb_stdlog,
3131 "infrun: proceed: [%s] needs step-over\n",
3132 target_pid_to_str (tp->ptid));
3137 fprintf_unfiltered (gdb_stdlog,
3138 "infrun: proceed: resuming %s\n",
3139 target_pid_to_str (tp->ptid));
3141 reset_ecs (ecs, tp);
3142 switch_to_thread (tp->ptid);
3143 keep_going_pass_signal (ecs);
3144 if (!ecs->wait_some_more)
3145 error (_("Command aborted."));
3148 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3150 /* The thread wasn't started, and isn't queued, run it now. */
3151 reset_ecs (ecs, tp);
3152 switch_to_thread (tp->ptid);
3153 keep_going_pass_signal (ecs);
3154 if (!ecs->wait_some_more)
3155 error (_("Command aborted."));
3158 discard_cleanups (old_chain);
3160 /* Tell the event loop to wait for it to stop. If the target
3161 supports asynchronous execution, it'll do this from within
3163 if (!target_can_async_p ())
3164 mark_async_event_handler (infrun_async_inferior_event_token);
3168 /* Start remote-debugging of a machine over a serial link. */
3171 start_remote (int from_tty)
3173 struct inferior *inferior;
3175 inferior = current_inferior ();
3176 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3178 /* Always go on waiting for the target, regardless of the mode. */
3179 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3180 indicate to wait_for_inferior that a target should timeout if
3181 nothing is returned (instead of just blocking). Because of this,
3182 targets expecting an immediate response need to, internally, set
3183 things up so that the target_wait() is forced to eventually
3185 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3186 differentiate to its caller what the state of the target is after
3187 the initial open has been performed. Here we're assuming that
3188 the target has stopped. It should be possible to eventually have
3189 target_open() return to the caller an indication that the target
3190 is currently running and GDB state should be set to the same as
3191 for an async run. */
3192 wait_for_inferior ();
3194 /* Now that the inferior has stopped, do any bookkeeping like
3195 loading shared libraries. We want to do this before normal_stop,
3196 so that the displayed frame is up to date. */
3197 post_create_inferior (¤t_target, from_tty);
3202 /* Initialize static vars when a new inferior begins. */
3205 init_wait_for_inferior (void)
3207 /* These are meaningless until the first time through wait_for_inferior. */
3209 breakpoint_init_inferior (inf_starting);
3211 clear_proceed_status (0);
3213 target_last_wait_ptid = minus_one_ptid;
3215 previous_inferior_ptid = inferior_ptid;
3217 /* Discard any skipped inlined frames. */
3218 clear_inline_frame_state (minus_one_ptid);
3223 static void handle_inferior_event (struct execution_control_state *ecs);
3225 static void handle_step_into_function (struct gdbarch *gdbarch,
3226 struct execution_control_state *ecs);
3227 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3228 struct execution_control_state *ecs);
3229 static void handle_signal_stop (struct execution_control_state *ecs);
3230 static void check_exception_resume (struct execution_control_state *,
3231 struct frame_info *);
3233 static void end_stepping_range (struct execution_control_state *ecs);
3234 static void stop_waiting (struct execution_control_state *ecs);
3235 static void keep_going (struct execution_control_state *ecs);
3236 static void process_event_stop_test (struct execution_control_state *ecs);
3237 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3239 /* Callback for iterate over threads. If the thread is stopped, but
3240 the user/frontend doesn't know about that yet, go through
3241 normal_stop, as if the thread had just stopped now. ARG points at
3242 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
3243 ptid_is_pid(PTID) is true, applies to all threads of the process
3244 pointed at by PTID. Otherwise, apply only to the thread pointed by
3248 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
3250 ptid_t ptid = * (ptid_t *) arg;
3252 if ((ptid_equal (info->ptid, ptid)
3253 || ptid_equal (minus_one_ptid, ptid)
3254 || (ptid_is_pid (ptid)
3255 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
3256 && is_running (info->ptid)
3257 && !is_executing (info->ptid))
3259 struct cleanup *old_chain;
3260 struct execution_control_state ecss;
3261 struct execution_control_state *ecs = &ecss;
3263 memset (ecs, 0, sizeof (*ecs));
3265 old_chain = make_cleanup_restore_current_thread ();
3267 overlay_cache_invalid = 1;
3268 /* Flush target cache before starting to handle each event.
3269 Target was running and cache could be stale. This is just a
3270 heuristic. Running threads may modify target memory, but we
3271 don't get any event. */
3272 target_dcache_invalidate ();
3274 /* Go through handle_inferior_event/normal_stop, so we always
3275 have consistent output as if the stop event had been
3277 ecs->ptid = info->ptid;
3278 ecs->event_thread = info;
3279 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
3280 ecs->ws.value.sig = GDB_SIGNAL_0;
3282 handle_inferior_event (ecs);
3284 if (!ecs->wait_some_more)
3286 /* Cancel any running execution command. */
3287 thread_cancel_execution_command (info);
3292 do_cleanups (old_chain);
3298 /* This function is attached as a "thread_stop_requested" observer.
3299 Cleanup local state that assumed the PTID was to be resumed, and
3300 report the stop to the frontend. */
3303 infrun_thread_stop_requested (ptid_t ptid)
3305 struct thread_info *tp;
3307 /* PTID was requested to stop. Remove matching threads from the
3308 step-over queue, so we don't try to resume them
3310 ALL_NON_EXITED_THREADS (tp)
3311 if (ptid_match (tp->ptid, ptid))
3313 if (thread_is_in_step_over_chain (tp))
3314 thread_step_over_chain_remove (tp);
3317 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
3321 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3323 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3324 nullify_last_target_wait_ptid ();
3327 /* Delete the step resume, single-step and longjmp/exception resume
3328 breakpoints of TP. */
3331 delete_thread_infrun_breakpoints (struct thread_info *tp)
3333 delete_step_resume_breakpoint (tp);
3334 delete_exception_resume_breakpoint (tp);
3335 delete_single_step_breakpoints (tp);
3338 /* If the target still has execution, call FUNC for each thread that
3339 just stopped. In all-stop, that's all the non-exited threads; in
3340 non-stop, that's the current thread, only. */
3342 typedef void (*for_each_just_stopped_thread_callback_func)
3343 (struct thread_info *tp);
3346 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3348 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3351 if (target_is_non_stop_p ())
3353 /* If in non-stop mode, only the current thread stopped. */
3354 func (inferior_thread ());
3358 struct thread_info *tp;
3360 /* In all-stop mode, all threads have stopped. */
3361 ALL_NON_EXITED_THREADS (tp)
3368 /* Delete the step resume and longjmp/exception resume breakpoints of
3369 the threads that just stopped. */
3372 delete_just_stopped_threads_infrun_breakpoints (void)
3374 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3377 /* Delete the single-step breakpoints of the threads that just
3381 delete_just_stopped_threads_single_step_breakpoints (void)
3383 for_each_just_stopped_thread (delete_single_step_breakpoints);
3386 /* A cleanup wrapper. */
3389 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3391 delete_just_stopped_threads_infrun_breakpoints ();
3397 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3398 const struct target_waitstatus *ws)
3400 char *status_string = target_waitstatus_to_string (ws);
3401 struct ui_file *tmp_stream = mem_fileopen ();
3404 /* The text is split over several lines because it was getting too long.
3405 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3406 output as a unit; we want only one timestamp printed if debug_timestamp
3409 fprintf_unfiltered (tmp_stream,
3410 "infrun: target_wait (%d.%ld.%ld",
3411 ptid_get_pid (waiton_ptid),
3412 ptid_get_lwp (waiton_ptid),
3413 ptid_get_tid (waiton_ptid));
3414 if (ptid_get_pid (waiton_ptid) != -1)
3415 fprintf_unfiltered (tmp_stream,
3416 " [%s]", target_pid_to_str (waiton_ptid));
3417 fprintf_unfiltered (tmp_stream, ", status) =\n");
3418 fprintf_unfiltered (tmp_stream,
3419 "infrun: %d.%ld.%ld [%s],\n",
3420 ptid_get_pid (result_ptid),
3421 ptid_get_lwp (result_ptid),
3422 ptid_get_tid (result_ptid),
3423 target_pid_to_str (result_ptid));
3424 fprintf_unfiltered (tmp_stream,
3428 text = ui_file_xstrdup (tmp_stream, NULL);
3430 /* This uses %s in part to handle %'s in the text, but also to avoid
3431 a gcc error: the format attribute requires a string literal. */
3432 fprintf_unfiltered (gdb_stdlog, "%s", text);
3434 xfree (status_string);
3436 ui_file_delete (tmp_stream);
3439 /* Select a thread at random, out of those which are resumed and have
3442 static struct thread_info *
3443 random_pending_event_thread (ptid_t waiton_ptid)
3445 struct thread_info *event_tp;
3447 int random_selector;
3449 /* First see how many events we have. Count only resumed threads
3450 that have an event pending. */
3451 ALL_NON_EXITED_THREADS (event_tp)
3452 if (ptid_match (event_tp->ptid, waiton_ptid)
3453 && event_tp->resumed
3454 && event_tp->suspend.waitstatus_pending_p)
3457 if (num_events == 0)
3460 /* Now randomly pick a thread out of those that have had events. */
3461 random_selector = (int)
3462 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3464 if (debug_infrun && num_events > 1)
3465 fprintf_unfiltered (gdb_stdlog,
3466 "infrun: Found %d events, selecting #%d\n",
3467 num_events, random_selector);
3469 /* Select the Nth thread that has had an event. */
3470 ALL_NON_EXITED_THREADS (event_tp)
3471 if (ptid_match (event_tp->ptid, waiton_ptid)
3472 && event_tp->resumed
3473 && event_tp->suspend.waitstatus_pending_p)
3474 if (random_selector-- == 0)
3480 /* Wrapper for target_wait that first checks whether threads have
3481 pending statuses to report before actually asking the target for
3485 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3488 struct thread_info *tp;
3490 /* First check if there is a resumed thread with a wait status
3492 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3494 tp = random_pending_event_thread (ptid);
3499 fprintf_unfiltered (gdb_stdlog,
3500 "infrun: Waiting for specific thread %s.\n",
3501 target_pid_to_str (ptid));
3503 /* We have a specific thread to check. */
3504 tp = find_thread_ptid (ptid);
3505 gdb_assert (tp != NULL);
3506 if (!tp->suspend.waitstatus_pending_p)
3511 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3512 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3514 struct regcache *regcache = get_thread_regcache (tp->ptid);
3515 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3519 pc = regcache_read_pc (regcache);
3521 if (pc != tp->suspend.stop_pc)
3524 fprintf_unfiltered (gdb_stdlog,
3525 "infrun: PC of %s changed. was=%s, now=%s\n",
3526 target_pid_to_str (tp->ptid),
3527 paddress (gdbarch, tp->prev_pc),
3528 paddress (gdbarch, pc));
3531 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3534 fprintf_unfiltered (gdb_stdlog,
3535 "infrun: previous breakpoint of %s, at %s gone\n",
3536 target_pid_to_str (tp->ptid),
3537 paddress (gdbarch, pc));
3545 fprintf_unfiltered (gdb_stdlog,
3546 "infrun: pending event of %s cancelled.\n",
3547 target_pid_to_str (tp->ptid));
3549 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3550 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3560 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
3561 fprintf_unfiltered (gdb_stdlog,
3562 "infrun: Using pending wait status %s for %s.\n",
3564 target_pid_to_str (tp->ptid));
3568 /* Now that we've selected our final event LWP, un-adjust its PC
3569 if it was a software breakpoint (and the target doesn't
3570 always adjust the PC itself). */
3571 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3572 && !target_supports_stopped_by_sw_breakpoint ())
3574 struct regcache *regcache;
3575 struct gdbarch *gdbarch;
3578 regcache = get_thread_regcache (tp->ptid);
3579 gdbarch = get_regcache_arch (regcache);
3581 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3586 pc = regcache_read_pc (regcache);
3587 regcache_write_pc (regcache, pc + decr_pc);
3591 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3592 *status = tp->suspend.waitstatus;
3593 tp->suspend.waitstatus_pending_p = 0;
3595 /* Wake up the event loop again, until all pending events are
3597 if (target_is_async_p ())
3598 mark_async_event_handler (infrun_async_inferior_event_token);
3602 /* But if we don't find one, we'll have to wait. */
3604 if (deprecated_target_wait_hook)
3605 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3607 event_ptid = target_wait (ptid, status, options);
3612 /* Prepare and stabilize the inferior for detaching it. E.g.,
3613 detaching while a thread is displaced stepping is a recipe for
3614 crashing it, as nothing would readjust the PC out of the scratch
3618 prepare_for_detach (void)
3620 struct inferior *inf = current_inferior ();
3621 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3622 struct cleanup *old_chain_1;
3623 struct displaced_step_inferior_state *displaced;
3625 displaced = get_displaced_stepping_state (inf->pid);
3627 /* Is any thread of this process displaced stepping? If not,
3628 there's nothing else to do. */
3629 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3633 fprintf_unfiltered (gdb_stdlog,
3634 "displaced-stepping in-process while detaching");
3636 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3639 while (!ptid_equal (displaced->step_ptid, null_ptid))
3641 struct cleanup *old_chain_2;
3642 struct execution_control_state ecss;
3643 struct execution_control_state *ecs;
3646 memset (ecs, 0, sizeof (*ecs));
3648 overlay_cache_invalid = 1;
3649 /* Flush target cache before starting to handle each event.
3650 Target was running and cache could be stale. This is just a
3651 heuristic. Running threads may modify target memory, but we
3652 don't get any event. */
3653 target_dcache_invalidate ();
3655 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3658 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3660 /* If an error happens while handling the event, propagate GDB's
3661 knowledge of the executing state to the frontend/user running
3663 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3666 /* Now figure out what to do with the result of the result. */
3667 handle_inferior_event (ecs);
3669 /* No error, don't finish the state yet. */
3670 discard_cleanups (old_chain_2);
3672 /* Breakpoints and watchpoints are not installed on the target
3673 at this point, and signals are passed directly to the
3674 inferior, so this must mean the process is gone. */
3675 if (!ecs->wait_some_more)
3677 discard_cleanups (old_chain_1);
3678 error (_("Program exited while detaching"));
3682 discard_cleanups (old_chain_1);
3685 /* Wait for control to return from inferior to debugger.
3687 If inferior gets a signal, we may decide to start it up again
3688 instead of returning. That is why there is a loop in this function.
3689 When this function actually returns it means the inferior
3690 should be left stopped and GDB should read more commands. */
3693 wait_for_inferior (void)
3695 struct cleanup *old_cleanups;
3696 struct cleanup *thread_state_chain;
3700 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3703 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3706 /* If an error happens while handling the event, propagate GDB's
3707 knowledge of the executing state to the frontend/user running
3709 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3713 struct execution_control_state ecss;
3714 struct execution_control_state *ecs = &ecss;
3715 ptid_t waiton_ptid = minus_one_ptid;
3717 memset (ecs, 0, sizeof (*ecs));
3719 overlay_cache_invalid = 1;
3721 /* Flush target cache before starting to handle each event.
3722 Target was running and cache could be stale. This is just a
3723 heuristic. Running threads may modify target memory, but we
3724 don't get any event. */
3725 target_dcache_invalidate ();
3727 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3730 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3732 /* Now figure out what to do with the result of the result. */
3733 handle_inferior_event (ecs);
3735 if (!ecs->wait_some_more)
3739 /* No error, don't finish the state yet. */
3740 discard_cleanups (thread_state_chain);
3742 do_cleanups (old_cleanups);
3745 /* Cleanup that reinstalls the readline callback handler, if the
3746 target is running in the background. If while handling the target
3747 event something triggered a secondary prompt, like e.g., a
3748 pagination prompt, we'll have removed the callback handler (see
3749 gdb_readline_wrapper_line). Need to do this as we go back to the
3750 event loop, ready to process further input. Note this has no
3751 effect if the handler hasn't actually been removed, because calling
3752 rl_callback_handler_install resets the line buffer, thus losing
3756 reinstall_readline_callback_handler_cleanup (void *arg)
3758 if (!interpreter_async)
3760 /* We're not going back to the top level event loop yet. Don't
3761 install the readline callback, as it'd prep the terminal,
3762 readline-style (raw, noecho) (e.g., --batch). We'll install
3763 it the next time the prompt is displayed, when we're ready
3768 if (async_command_editing_p && !sync_execution)
3769 gdb_rl_callback_handler_reinstall ();
3772 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3773 that's just the event thread. In all-stop, that's all threads. */
3776 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3778 struct thread_info *thr = ecs->event_thread;
3780 if (thr != NULL && thr->thread_fsm != NULL)
3781 thread_fsm_clean_up (thr->thread_fsm);
3785 ALL_NON_EXITED_THREADS (thr)
3787 if (thr->thread_fsm == NULL)
3789 if (thr == ecs->event_thread)
3792 switch_to_thread (thr->ptid);
3793 thread_fsm_clean_up (thr->thread_fsm);
3796 if (ecs->event_thread != NULL)
3797 switch_to_thread (ecs->event_thread->ptid);
3801 /* A cleanup that restores the execution direction to the value saved
3805 restore_execution_direction (void *arg)
3807 enum exec_direction_kind *save_exec_dir = (enum exec_direction_kind *) arg;
3809 execution_direction = *save_exec_dir;
3812 /* Asynchronous version of wait_for_inferior. It is called by the
3813 event loop whenever a change of state is detected on the file
3814 descriptor corresponding to the target. It can be called more than
3815 once to complete a single execution command. In such cases we need
3816 to keep the state in a global variable ECSS. If it is the last time
3817 that this function is called for a single execution command, then
3818 report to the user that the inferior has stopped, and do the
3819 necessary cleanups. */
3822 fetch_inferior_event (void *client_data)
3824 struct execution_control_state ecss;
3825 struct execution_control_state *ecs = &ecss;
3826 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3827 struct cleanup *ts_old_chain;
3828 int was_sync = sync_execution;
3829 enum exec_direction_kind save_exec_dir = execution_direction;
3831 ptid_t waiton_ptid = minus_one_ptid;
3833 memset (ecs, 0, sizeof (*ecs));
3835 /* End up with readline processing input, if necessary. */
3836 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3838 /* We're handling a live event, so make sure we're doing live
3839 debugging. If we're looking at traceframes while the target is
3840 running, we're going to need to get back to that mode after
3841 handling the event. */
3844 make_cleanup_restore_current_traceframe ();
3845 set_current_traceframe (-1);
3849 /* In non-stop mode, the user/frontend should not notice a thread
3850 switch due to internal events. Make sure we reverse to the
3851 user selected thread and frame after handling the event and
3852 running any breakpoint commands. */
3853 make_cleanup_restore_current_thread ();
3855 overlay_cache_invalid = 1;
3856 /* Flush target cache before starting to handle each event. Target
3857 was running and cache could be stale. This is just a heuristic.
3858 Running threads may modify target memory, but we don't get any
3860 target_dcache_invalidate ();
3862 make_cleanup (restore_execution_direction, &save_exec_dir);
3863 execution_direction = target_execution_direction ();
3865 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3866 target_can_async_p () ? TARGET_WNOHANG : 0);
3869 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3871 /* If an error happens while handling the event, propagate GDB's
3872 knowledge of the executing state to the frontend/user running
3874 if (!target_is_non_stop_p ())
3875 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3877 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3879 /* Get executed before make_cleanup_restore_current_thread above to apply
3880 still for the thread which has thrown the exception. */
3881 make_bpstat_clear_actions_cleanup ();
3883 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3885 /* Now figure out what to do with the result of the result. */
3886 handle_inferior_event (ecs);
3888 if (!ecs->wait_some_more)
3890 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3891 int should_stop = 1;
3892 struct thread_info *thr = ecs->event_thread;
3893 int should_notify_stop = 1;
3895 delete_just_stopped_threads_infrun_breakpoints ();
3899 struct thread_fsm *thread_fsm = thr->thread_fsm;
3901 if (thread_fsm != NULL)
3902 should_stop = thread_fsm_should_stop (thread_fsm);
3911 clean_up_just_stopped_threads_fsms (ecs);
3913 if (thr != NULL && thr->thread_fsm != NULL)
3916 = thread_fsm_should_notify_stop (thr->thread_fsm);
3919 if (should_notify_stop)
3923 /* We may not find an inferior if this was a process exit. */
3924 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3925 proceeded = normal_stop ();
3929 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3936 /* No error, don't finish the thread states yet. */
3937 discard_cleanups (ts_old_chain);
3939 /* Revert thread and frame. */
3940 do_cleanups (old_chain);
3942 /* If the inferior was in sync execution mode, and now isn't,
3943 restore the prompt (a synchronous execution command has finished,
3944 and we're ready for input). */
3945 if (interpreter_async && was_sync && !sync_execution)
3946 observer_notify_sync_execution_done ();
3950 && exec_done_display_p
3951 && (ptid_equal (inferior_ptid, null_ptid)
3952 || !is_running (inferior_ptid)))
3953 printf_unfiltered (_("completed.\n"));
3956 /* Record the frame and location we're currently stepping through. */
3958 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3960 struct thread_info *tp = inferior_thread ();
3962 tp->control.step_frame_id = get_frame_id (frame);
3963 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3965 tp->current_symtab = sal.symtab;
3966 tp->current_line = sal.line;
3969 /* Clear context switchable stepping state. */
3972 init_thread_stepping_state (struct thread_info *tss)
3974 tss->stepped_breakpoint = 0;
3975 tss->stepping_over_breakpoint = 0;
3976 tss->stepping_over_watchpoint = 0;
3977 tss->step_after_step_resume_breakpoint = 0;
3980 /* Set the cached copy of the last ptid/waitstatus. */
3983 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3985 target_last_wait_ptid = ptid;
3986 target_last_waitstatus = status;
3989 /* Return the cached copy of the last pid/waitstatus returned by
3990 target_wait()/deprecated_target_wait_hook(). The data is actually
3991 cached by handle_inferior_event(), which gets called immediately
3992 after target_wait()/deprecated_target_wait_hook(). */
3995 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3997 *ptidp = target_last_wait_ptid;
3998 *status = target_last_waitstatus;
4002 nullify_last_target_wait_ptid (void)
4004 target_last_wait_ptid = minus_one_ptid;
4007 /* Switch thread contexts. */
4010 context_switch (ptid_t ptid)
4012 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4014 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4015 target_pid_to_str (inferior_ptid));
4016 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4017 target_pid_to_str (ptid));
4020 switch_to_thread (ptid);
4023 /* If the target can't tell whether we've hit breakpoints
4024 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4025 check whether that could have been caused by a breakpoint. If so,
4026 adjust the PC, per gdbarch_decr_pc_after_break. */
4029 adjust_pc_after_break (struct thread_info *thread,
4030 struct target_waitstatus *ws)
4032 struct regcache *regcache;
4033 struct gdbarch *gdbarch;
4034 struct address_space *aspace;
4035 CORE_ADDR breakpoint_pc, decr_pc;
4037 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4038 we aren't, just return.
4040 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4041 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4042 implemented by software breakpoints should be handled through the normal
4045 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4046 different signals (SIGILL or SIGEMT for instance), but it is less
4047 clear where the PC is pointing afterwards. It may not match
4048 gdbarch_decr_pc_after_break. I don't know any specific target that
4049 generates these signals at breakpoints (the code has been in GDB since at
4050 least 1992) so I can not guess how to handle them here.
4052 In earlier versions of GDB, a target with
4053 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4054 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4055 target with both of these set in GDB history, and it seems unlikely to be
4056 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4058 if (ws->kind != TARGET_WAITKIND_STOPPED)
4061 if (ws->value.sig != GDB_SIGNAL_TRAP)
4064 /* In reverse execution, when a breakpoint is hit, the instruction
4065 under it has already been de-executed. The reported PC always
4066 points at the breakpoint address, so adjusting it further would
4067 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4070 B1 0x08000000 : INSN1
4071 B2 0x08000001 : INSN2
4073 PC -> 0x08000003 : INSN4
4075 Say you're stopped at 0x08000003 as above. Reverse continuing
4076 from that point should hit B2 as below. Reading the PC when the
4077 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4078 been de-executed already.
4080 B1 0x08000000 : INSN1
4081 B2 PC -> 0x08000001 : INSN2
4085 We can't apply the same logic as for forward execution, because
4086 we would wrongly adjust the PC to 0x08000000, since there's a
4087 breakpoint at PC - 1. We'd then report a hit on B1, although
4088 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4090 if (execution_direction == EXEC_REVERSE)
4093 /* If the target can tell whether the thread hit a SW breakpoint,
4094 trust it. Targets that can tell also adjust the PC
4096 if (target_supports_stopped_by_sw_breakpoint ())
4099 /* Note that relying on whether a breakpoint is planted in memory to
4100 determine this can fail. E.g,. the breakpoint could have been
4101 removed since. Or the thread could have been told to step an
4102 instruction the size of a breakpoint instruction, and only
4103 _after_ was a breakpoint inserted at its address. */
4105 /* If this target does not decrement the PC after breakpoints, then
4106 we have nothing to do. */
4107 regcache = get_thread_regcache (thread->ptid);
4108 gdbarch = get_regcache_arch (regcache);
4110 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4114 aspace = get_regcache_aspace (regcache);
4116 /* Find the location where (if we've hit a breakpoint) the
4117 breakpoint would be. */
4118 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4120 /* If the target can't tell whether a software breakpoint triggered,
4121 fallback to figuring it out based on breakpoints we think were
4122 inserted in the target, and on whether the thread was stepped or
4125 /* Check whether there actually is a software breakpoint inserted at
4128 If in non-stop mode, a race condition is possible where we've
4129 removed a breakpoint, but stop events for that breakpoint were
4130 already queued and arrive later. To suppress those spurious
4131 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4132 and retire them after a number of stop events are reported. Note
4133 this is an heuristic and can thus get confused. The real fix is
4134 to get the "stopped by SW BP and needs adjustment" info out of
4135 the target/kernel (and thus never reach here; see above). */
4136 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4137 || (target_is_non_stop_p ()
4138 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4140 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4142 if (record_full_is_used ())
4143 record_full_gdb_operation_disable_set ();
4145 /* When using hardware single-step, a SIGTRAP is reported for both
4146 a completed single-step and a software breakpoint. Need to
4147 differentiate between the two, as the latter needs adjusting
4148 but the former does not.
4150 The SIGTRAP can be due to a completed hardware single-step only if
4151 - we didn't insert software single-step breakpoints
4152 - this thread is currently being stepped
4154 If any of these events did not occur, we must have stopped due
4155 to hitting a software breakpoint, and have to back up to the
4158 As a special case, we could have hardware single-stepped a
4159 software breakpoint. In this case (prev_pc == breakpoint_pc),
4160 we also need to back up to the breakpoint address. */
4162 if (thread_has_single_step_breakpoints_set (thread)
4163 || !currently_stepping (thread)
4164 || (thread->stepped_breakpoint
4165 && thread->prev_pc == breakpoint_pc))
4166 regcache_write_pc (regcache, breakpoint_pc);
4168 do_cleanups (old_cleanups);
4173 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4175 for (frame = get_prev_frame (frame);
4177 frame = get_prev_frame (frame))
4179 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4181 if (get_frame_type (frame) != INLINE_FRAME)
4188 /* Auxiliary function that handles syscall entry/return events.
4189 It returns 1 if the inferior should keep going (and GDB
4190 should ignore the event), or 0 if the event deserves to be
4194 handle_syscall_event (struct execution_control_state *ecs)
4196 struct regcache *regcache;
4199 if (!ptid_equal (ecs->ptid, inferior_ptid))
4200 context_switch (ecs->ptid);
4202 regcache = get_thread_regcache (ecs->ptid);
4203 syscall_number = ecs->ws.value.syscall_number;
4204 stop_pc = regcache_read_pc (regcache);
4206 if (catch_syscall_enabled () > 0
4207 && catching_syscall_number (syscall_number) > 0)
4210 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4213 ecs->event_thread->control.stop_bpstat
4214 = bpstat_stop_status (get_regcache_aspace (regcache),
4215 stop_pc, ecs->ptid, &ecs->ws);
4217 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4219 /* Catchpoint hit. */
4224 /* If no catchpoint triggered for this, then keep going. */
4229 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4232 fill_in_stop_func (struct gdbarch *gdbarch,
4233 struct execution_control_state *ecs)
4235 if (!ecs->stop_func_filled_in)
4237 /* Don't care about return value; stop_func_start and stop_func_name
4238 will both be 0 if it doesn't work. */
4239 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4240 &ecs->stop_func_start, &ecs->stop_func_end);
4241 ecs->stop_func_start
4242 += gdbarch_deprecated_function_start_offset (gdbarch);
4244 if (gdbarch_skip_entrypoint_p (gdbarch))
4245 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4246 ecs->stop_func_start);
4248 ecs->stop_func_filled_in = 1;
4253 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4255 static enum stop_kind
4256 get_inferior_stop_soon (ptid_t ptid)
4258 struct inferior *inf = find_inferior_ptid (ptid);
4260 gdb_assert (inf != NULL);
4261 return inf->control.stop_soon;
4264 /* Wait for one event. Store the resulting waitstatus in WS, and
4265 return the event ptid. */
4268 wait_one (struct target_waitstatus *ws)
4271 ptid_t wait_ptid = minus_one_ptid;
4273 overlay_cache_invalid = 1;
4275 /* Flush target cache before starting to handle each event.
4276 Target was running and cache could be stale. This is just a
4277 heuristic. Running threads may modify target memory, but we
4278 don't get any event. */
4279 target_dcache_invalidate ();
4281 if (deprecated_target_wait_hook)
4282 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4284 event_ptid = target_wait (wait_ptid, ws, 0);
4287 print_target_wait_results (wait_ptid, event_ptid, ws);
4292 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4293 instead of the current thread. */
4294 #define THREAD_STOPPED_BY(REASON) \
4296 thread_stopped_by_ ## REASON (ptid_t ptid) \
4298 struct cleanup *old_chain; \
4301 old_chain = save_inferior_ptid (); \
4302 inferior_ptid = ptid; \
4304 res = target_stopped_by_ ## REASON (); \
4306 do_cleanups (old_chain); \
4311 /* Generate thread_stopped_by_watchpoint. */
4312 THREAD_STOPPED_BY (watchpoint)
4313 /* Generate thread_stopped_by_sw_breakpoint. */
4314 THREAD_STOPPED_BY (sw_breakpoint)
4315 /* Generate thread_stopped_by_hw_breakpoint. */
4316 THREAD_STOPPED_BY (hw_breakpoint)
4318 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4321 switch_to_thread_cleanup (void *ptid_p)
4323 ptid_t ptid = *(ptid_t *) ptid_p;
4325 switch_to_thread (ptid);
4328 /* Save the thread's event and stop reason to process it later. */
4331 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4333 struct regcache *regcache;
4334 struct address_space *aspace;
4340 statstr = target_waitstatus_to_string (ws);
4341 fprintf_unfiltered (gdb_stdlog,
4342 "infrun: saving status %s for %d.%ld.%ld\n",
4344 ptid_get_pid (tp->ptid),
4345 ptid_get_lwp (tp->ptid),
4346 ptid_get_tid (tp->ptid));
4350 /* Record for later. */
4351 tp->suspend.waitstatus = *ws;
4352 tp->suspend.waitstatus_pending_p = 1;
4354 regcache = get_thread_regcache (tp->ptid);
4355 aspace = get_regcache_aspace (regcache);
4357 if (ws->kind == TARGET_WAITKIND_STOPPED
4358 && ws->value.sig == GDB_SIGNAL_TRAP)
4360 CORE_ADDR pc = regcache_read_pc (regcache);
4362 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4364 if (thread_stopped_by_watchpoint (tp->ptid))
4366 tp->suspend.stop_reason
4367 = TARGET_STOPPED_BY_WATCHPOINT;
4369 else if (target_supports_stopped_by_sw_breakpoint ()
4370 && thread_stopped_by_sw_breakpoint (tp->ptid))
4372 tp->suspend.stop_reason
4373 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4375 else if (target_supports_stopped_by_hw_breakpoint ()
4376 && thread_stopped_by_hw_breakpoint (tp->ptid))
4378 tp->suspend.stop_reason
4379 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4381 else if (!target_supports_stopped_by_hw_breakpoint ()
4382 && hardware_breakpoint_inserted_here_p (aspace,
4385 tp->suspend.stop_reason
4386 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4388 else if (!target_supports_stopped_by_sw_breakpoint ()
4389 && software_breakpoint_inserted_here_p (aspace,
4392 tp->suspend.stop_reason
4393 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4395 else if (!thread_has_single_step_breakpoints_set (tp)
4396 && currently_stepping (tp))
4398 tp->suspend.stop_reason
4399 = TARGET_STOPPED_BY_SINGLE_STEP;
4404 /* Stop all threads. */
4407 stop_all_threads (void)
4409 /* We may need multiple passes to discover all threads. */
4413 struct cleanup *old_chain;
4415 gdb_assert (target_is_non_stop_p ());
4418 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4420 entry_ptid = inferior_ptid;
4421 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4423 /* Request threads to stop, and then wait for the stops. Because
4424 threads we already know about can spawn more threads while we're
4425 trying to stop them, and we only learn about new threads when we
4426 update the thread list, do this in a loop, and keep iterating
4427 until two passes find no threads that need to be stopped. */
4428 for (pass = 0; pass < 2; pass++, iterations++)
4431 fprintf_unfiltered (gdb_stdlog,
4432 "infrun: stop_all_threads, pass=%d, "
4433 "iterations=%d\n", pass, iterations);
4437 struct target_waitstatus ws;
4439 struct thread_info *t;
4441 update_thread_list ();
4443 /* Go through all threads looking for threads that we need
4444 to tell the target to stop. */
4445 ALL_NON_EXITED_THREADS (t)
4449 /* If already stopping, don't request a stop again.
4450 We just haven't seen the notification yet. */
4451 if (!t->stop_requested)
4454 fprintf_unfiltered (gdb_stdlog,
4455 "infrun: %s executing, "
4457 target_pid_to_str (t->ptid));
4458 target_stop (t->ptid);
4459 t->stop_requested = 1;
4464 fprintf_unfiltered (gdb_stdlog,
4465 "infrun: %s executing, "
4466 "already stopping\n",
4467 target_pid_to_str (t->ptid));
4470 if (t->stop_requested)
4476 fprintf_unfiltered (gdb_stdlog,
4477 "infrun: %s not executing\n",
4478 target_pid_to_str (t->ptid));
4480 /* The thread may be not executing, but still be
4481 resumed with a pending status to process. */
4489 /* If we find new threads on the second iteration, restart
4490 over. We want to see two iterations in a row with all
4495 event_ptid = wait_one (&ws);
4496 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4498 /* All resumed threads exited. */
4500 else if (ws.kind == TARGET_WAITKIND_EXITED
4501 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4505 ptid_t ptid = pid_to_ptid (ws.value.integer);
4507 fprintf_unfiltered (gdb_stdlog,
4508 "infrun: %s exited while "
4509 "stopping threads\n",
4510 target_pid_to_str (ptid));
4515 t = find_thread_ptid (event_ptid);
4517 t = add_thread (event_ptid);
4519 t->stop_requested = 0;
4522 t->control.may_range_step = 0;
4524 if (ws.kind == TARGET_WAITKIND_STOPPED
4525 && ws.value.sig == GDB_SIGNAL_0)
4527 /* We caught the event that we intended to catch, so
4528 there's no event pending. */
4529 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4530 t->suspend.waitstatus_pending_p = 0;
4532 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4534 /* Add it back to the step-over queue. */
4537 fprintf_unfiltered (gdb_stdlog,
4538 "infrun: displaced-step of %s "
4539 "canceled: adding back to the "
4540 "step-over queue\n",
4541 target_pid_to_str (t->ptid));
4543 t->control.trap_expected = 0;
4544 thread_step_over_chain_enqueue (t);
4549 enum gdb_signal sig;
4550 struct regcache *regcache;
4551 struct address_space *aspace;
4557 statstr = target_waitstatus_to_string (&ws);
4558 fprintf_unfiltered (gdb_stdlog,
4559 "infrun: target_wait %s, saving "
4560 "status for %d.%ld.%ld\n",
4562 ptid_get_pid (t->ptid),
4563 ptid_get_lwp (t->ptid),
4564 ptid_get_tid (t->ptid));
4568 /* Record for later. */
4569 save_waitstatus (t, &ws);
4571 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4572 ? ws.value.sig : GDB_SIGNAL_0);
4574 if (displaced_step_fixup (t->ptid, sig) < 0)
4576 /* Add it back to the step-over queue. */
4577 t->control.trap_expected = 0;
4578 thread_step_over_chain_enqueue (t);
4581 regcache = get_thread_regcache (t->ptid);
4582 t->suspend.stop_pc = regcache_read_pc (regcache);
4586 fprintf_unfiltered (gdb_stdlog,
4587 "infrun: saved stop_pc=%s for %s "
4588 "(currently_stepping=%d)\n",
4589 paddress (target_gdbarch (),
4590 t->suspend.stop_pc),
4591 target_pid_to_str (t->ptid),
4592 currently_stepping (t));
4599 do_cleanups (old_chain);
4602 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4605 /* Given an execution control state that has been freshly filled in by
4606 an event from the inferior, figure out what it means and take
4609 The alternatives are:
4611 1) stop_waiting and return; to really stop and return to the
4614 2) keep_going and return; to wait for the next event (set
4615 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4619 handle_inferior_event_1 (struct execution_control_state *ecs)
4621 enum stop_kind stop_soon;
4623 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4625 /* We had an event in the inferior, but we are not interested in
4626 handling it at this level. The lower layers have already
4627 done what needs to be done, if anything.
4629 One of the possible circumstances for this is when the
4630 inferior produces output for the console. The inferior has
4631 not stopped, and we are ignoring the event. Another possible
4632 circumstance is any event which the lower level knows will be
4633 reported multiple times without an intervening resume. */
4635 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4636 prepare_to_wait (ecs);
4640 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4641 && target_can_async_p () && !sync_execution)
4643 /* There were no unwaited-for children left in the target, but,
4644 we're not synchronously waiting for events either. Just
4645 ignore. Otherwise, if we were running a synchronous
4646 execution command, we need to cancel it and give the user
4647 back the terminal. */
4649 fprintf_unfiltered (gdb_stdlog,
4650 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
4651 prepare_to_wait (ecs);
4655 /* Cache the last pid/waitstatus. */
4656 set_last_target_status (ecs->ptid, ecs->ws);
4658 /* Always clear state belonging to the previous time we stopped. */
4659 stop_stack_dummy = STOP_NONE;
4661 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4663 /* No unwaited-for children left. IOW, all resumed children
4666 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4668 stop_print_frame = 0;
4673 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4674 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4676 ecs->event_thread = find_thread_ptid (ecs->ptid);
4677 /* If it's a new thread, add it to the thread database. */
4678 if (ecs->event_thread == NULL)
4679 ecs->event_thread = add_thread (ecs->ptid);
4681 /* Disable range stepping. If the next step request could use a
4682 range, this will be end up re-enabled then. */
4683 ecs->event_thread->control.may_range_step = 0;
4686 /* Dependent on valid ECS->EVENT_THREAD. */
4687 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4689 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4690 reinit_frame_cache ();
4692 breakpoint_retire_moribund ();
4694 /* First, distinguish signals caused by the debugger from signals
4695 that have to do with the program's own actions. Note that
4696 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4697 on the operating system version. Here we detect when a SIGILL or
4698 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4699 something similar for SIGSEGV, since a SIGSEGV will be generated
4700 when we're trying to execute a breakpoint instruction on a
4701 non-executable stack. This happens for call dummy breakpoints
4702 for architectures like SPARC that place call dummies on the
4704 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4705 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4706 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4707 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4709 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4711 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
4712 regcache_read_pc (regcache)))
4715 fprintf_unfiltered (gdb_stdlog,
4716 "infrun: Treating signal as SIGTRAP\n");
4717 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4721 /* Mark the non-executing threads accordingly. In all-stop, all
4722 threads of all processes are stopped when we get any event
4723 reported. In non-stop mode, only the event thread stops. */
4727 if (!target_is_non_stop_p ())
4728 mark_ptid = minus_one_ptid;
4729 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4730 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4732 /* If we're handling a process exit in non-stop mode, even
4733 though threads haven't been deleted yet, one would think
4734 that there is nothing to do, as threads of the dead process
4735 will be soon deleted, and threads of any other process were
4736 left running. However, on some targets, threads survive a
4737 process exit event. E.g., for the "checkpoint" command,
4738 when the current checkpoint/fork exits, linux-fork.c
4739 automatically switches to another fork from within
4740 target_mourn_inferior, by associating the same
4741 inferior/thread to another fork. We haven't mourned yet at
4742 this point, but we must mark any threads left in the
4743 process as not-executing so that finish_thread_state marks
4744 them stopped (in the user's perspective) if/when we present
4745 the stop to the user. */
4746 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4749 mark_ptid = ecs->ptid;
4751 set_executing (mark_ptid, 0);
4753 /* Likewise the resumed flag. */
4754 set_resumed (mark_ptid, 0);
4757 switch (ecs->ws.kind)
4759 case TARGET_WAITKIND_LOADED:
4761 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4762 if (!ptid_equal (ecs->ptid, inferior_ptid))
4763 context_switch (ecs->ptid);
4764 /* Ignore gracefully during startup of the inferior, as it might
4765 be the shell which has just loaded some objects, otherwise
4766 add the symbols for the newly loaded objects. Also ignore at
4767 the beginning of an attach or remote session; we will query
4768 the full list of libraries once the connection is
4771 stop_soon = get_inferior_stop_soon (ecs->ptid);
4772 if (stop_soon == NO_STOP_QUIETLY)
4774 struct regcache *regcache;
4776 regcache = get_thread_regcache (ecs->ptid);
4778 handle_solib_event ();
4780 ecs->event_thread->control.stop_bpstat
4781 = bpstat_stop_status (get_regcache_aspace (regcache),
4782 stop_pc, ecs->ptid, &ecs->ws);
4784 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4786 /* A catchpoint triggered. */
4787 process_event_stop_test (ecs);
4791 /* If requested, stop when the dynamic linker notifies
4792 gdb of events. This allows the user to get control
4793 and place breakpoints in initializer routines for
4794 dynamically loaded objects (among other things). */
4795 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4796 if (stop_on_solib_events)
4798 /* Make sure we print "Stopped due to solib-event" in
4800 stop_print_frame = 1;
4807 /* If we are skipping through a shell, or through shared library
4808 loading that we aren't interested in, resume the program. If
4809 we're running the program normally, also resume. */
4810 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4812 /* Loading of shared libraries might have changed breakpoint
4813 addresses. Make sure new breakpoints are inserted. */
4814 if (stop_soon == NO_STOP_QUIETLY)
4815 insert_breakpoints ();
4816 resume (GDB_SIGNAL_0);
4817 prepare_to_wait (ecs);
4821 /* But stop if we're attaching or setting up a remote
4823 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4824 || stop_soon == STOP_QUIETLY_REMOTE)
4827 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4832 internal_error (__FILE__, __LINE__,
4833 _("unhandled stop_soon: %d"), (int) stop_soon);
4835 case TARGET_WAITKIND_SPURIOUS:
4837 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4838 if (!ptid_equal (ecs->ptid, inferior_ptid))
4839 context_switch (ecs->ptid);
4840 resume (GDB_SIGNAL_0);
4841 prepare_to_wait (ecs);
4844 case TARGET_WAITKIND_EXITED:
4845 case TARGET_WAITKIND_SIGNALLED:
4848 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4849 fprintf_unfiltered (gdb_stdlog,
4850 "infrun: TARGET_WAITKIND_EXITED\n");
4852 fprintf_unfiltered (gdb_stdlog,
4853 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4856 inferior_ptid = ecs->ptid;
4857 set_current_inferior (find_inferior_ptid (ecs->ptid));
4858 set_current_program_space (current_inferior ()->pspace);
4859 handle_vfork_child_exec_or_exit (0);
4860 target_terminal_ours (); /* Must do this before mourn anyway. */
4862 /* Clearing any previous state of convenience variables. */
4863 clear_exit_convenience_vars ();
4865 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4867 /* Record the exit code in the convenience variable $_exitcode, so
4868 that the user can inspect this again later. */
4869 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4870 (LONGEST) ecs->ws.value.integer);
4872 /* Also record this in the inferior itself. */
4873 current_inferior ()->has_exit_code = 1;
4874 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4876 /* Support the --return-child-result option. */
4877 return_child_result_value = ecs->ws.value.integer;
4879 observer_notify_exited (ecs->ws.value.integer);
4883 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4884 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4886 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4888 /* Set the value of the internal variable $_exitsignal,
4889 which holds the signal uncaught by the inferior. */
4890 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4891 gdbarch_gdb_signal_to_target (gdbarch,
4892 ecs->ws.value.sig));
4896 /* We don't have access to the target's method used for
4897 converting between signal numbers (GDB's internal
4898 representation <-> target's representation).
4899 Therefore, we cannot do a good job at displaying this
4900 information to the user. It's better to just warn
4901 her about it (if infrun debugging is enabled), and
4904 fprintf_filtered (gdb_stdlog, _("\
4905 Cannot fill $_exitsignal with the correct signal number.\n"));
4908 observer_notify_signal_exited (ecs->ws.value.sig);
4911 gdb_flush (gdb_stdout);
4912 target_mourn_inferior ();
4913 stop_print_frame = 0;
4917 /* The following are the only cases in which we keep going;
4918 the above cases end in a continue or goto. */
4919 case TARGET_WAITKIND_FORKED:
4920 case TARGET_WAITKIND_VFORKED:
4923 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4924 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4926 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4929 /* Check whether the inferior is displaced stepping. */
4931 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4932 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4933 struct displaced_step_inferior_state *displaced
4934 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
4936 /* If checking displaced stepping is supported, and thread
4937 ecs->ptid is displaced stepping. */
4938 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
4940 struct inferior *parent_inf
4941 = find_inferior_ptid (ecs->ptid);
4942 struct regcache *child_regcache;
4943 CORE_ADDR parent_pc;
4945 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4946 indicating that the displaced stepping of syscall instruction
4947 has been done. Perform cleanup for parent process here. Note
4948 that this operation also cleans up the child process for vfork,
4949 because their pages are shared. */
4950 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
4951 /* Start a new step-over in another thread if there's one
4955 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4957 /* Restore scratch pad for child process. */
4958 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4961 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4962 the child's PC is also within the scratchpad. Set the child's PC
4963 to the parent's PC value, which has already been fixed up.
4964 FIXME: we use the parent's aspace here, although we're touching
4965 the child, because the child hasn't been added to the inferior
4966 list yet at this point. */
4969 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4971 parent_inf->aspace);
4972 /* Read PC value of parent process. */
4973 parent_pc = regcache_read_pc (regcache);
4975 if (debug_displaced)
4976 fprintf_unfiltered (gdb_stdlog,
4977 "displaced: write child pc from %s to %s\n",
4979 regcache_read_pc (child_regcache)),
4980 paddress (gdbarch, parent_pc));
4982 regcache_write_pc (child_regcache, parent_pc);
4986 if (!ptid_equal (ecs->ptid, inferior_ptid))
4987 context_switch (ecs->ptid);
4989 /* Immediately detach breakpoints from the child before there's
4990 any chance of letting the user delete breakpoints from the
4991 breakpoint lists. If we don't do this early, it's easy to
4992 leave left over traps in the child, vis: "break foo; catch
4993 fork; c; <fork>; del; c; <child calls foo>". We only follow
4994 the fork on the last `continue', and by that time the
4995 breakpoint at "foo" is long gone from the breakpoint table.
4996 If we vforked, then we don't need to unpatch here, since both
4997 parent and child are sharing the same memory pages; we'll
4998 need to unpatch at follow/detach time instead to be certain
4999 that new breakpoints added between catchpoint hit time and
5000 vfork follow are detached. */
5001 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5003 /* This won't actually modify the breakpoint list, but will
5004 physically remove the breakpoints from the child. */
5005 detach_breakpoints (ecs->ws.value.related_pid);
5008 delete_just_stopped_threads_single_step_breakpoints ();
5010 /* In case the event is caught by a catchpoint, remember that
5011 the event is to be followed at the next resume of the thread,
5012 and not immediately. */
5013 ecs->event_thread->pending_follow = ecs->ws;
5015 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5017 ecs->event_thread->control.stop_bpstat
5018 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5019 stop_pc, ecs->ptid, &ecs->ws);
5021 /* If no catchpoint triggered for this, then keep going. Note
5022 that we're interested in knowing the bpstat actually causes a
5023 stop, not just if it may explain the signal. Software
5024 watchpoints, for example, always appear in the bpstat. */
5025 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5031 = (follow_fork_mode_string == follow_fork_mode_child);
5033 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5035 should_resume = follow_fork ();
5038 child = ecs->ws.value.related_pid;
5040 /* In non-stop mode, also resume the other branch. */
5041 if (!detach_fork && (non_stop
5042 || (sched_multi && target_is_non_stop_p ())))
5045 switch_to_thread (parent);
5047 switch_to_thread (child);
5049 ecs->event_thread = inferior_thread ();
5050 ecs->ptid = inferior_ptid;
5055 switch_to_thread (child);
5057 switch_to_thread (parent);
5059 ecs->event_thread = inferior_thread ();
5060 ecs->ptid = inferior_ptid;
5068 process_event_stop_test (ecs);
5071 case TARGET_WAITKIND_VFORK_DONE:
5072 /* Done with the shared memory region. Re-insert breakpoints in
5073 the parent, and keep going. */
5076 fprintf_unfiltered (gdb_stdlog,
5077 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5079 if (!ptid_equal (ecs->ptid, inferior_ptid))
5080 context_switch (ecs->ptid);
5082 current_inferior ()->waiting_for_vfork_done = 0;
5083 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5084 /* This also takes care of reinserting breakpoints in the
5085 previously locked inferior. */
5089 case TARGET_WAITKIND_EXECD:
5091 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5093 if (!ptid_equal (ecs->ptid, inferior_ptid))
5094 context_switch (ecs->ptid);
5096 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5098 /* Do whatever is necessary to the parent branch of the vfork. */
5099 handle_vfork_child_exec_or_exit (1);
5101 /* This causes the eventpoints and symbol table to be reset.
5102 Must do this now, before trying to determine whether to
5104 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5106 /* In follow_exec we may have deleted the original thread and
5107 created a new one. Make sure that the event thread is the
5108 execd thread for that case (this is a nop otherwise). */
5109 ecs->event_thread = inferior_thread ();
5111 ecs->event_thread->control.stop_bpstat
5112 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5113 stop_pc, ecs->ptid, &ecs->ws);
5115 /* Note that this may be referenced from inside
5116 bpstat_stop_status above, through inferior_has_execd. */
5117 xfree (ecs->ws.value.execd_pathname);
5118 ecs->ws.value.execd_pathname = NULL;
5120 /* If no catchpoint triggered for this, then keep going. */
5121 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5123 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5127 process_event_stop_test (ecs);
5130 /* Be careful not to try to gather much state about a thread
5131 that's in a syscall. It's frequently a losing proposition. */
5132 case TARGET_WAITKIND_SYSCALL_ENTRY:
5134 fprintf_unfiltered (gdb_stdlog,
5135 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5136 /* Getting the current syscall number. */
5137 if (handle_syscall_event (ecs) == 0)
5138 process_event_stop_test (ecs);
5141 /* Before examining the threads further, step this thread to
5142 get it entirely out of the syscall. (We get notice of the
5143 event when the thread is just on the verge of exiting a
5144 syscall. Stepping one instruction seems to get it back
5146 case TARGET_WAITKIND_SYSCALL_RETURN:
5148 fprintf_unfiltered (gdb_stdlog,
5149 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5150 if (handle_syscall_event (ecs) == 0)
5151 process_event_stop_test (ecs);
5154 case TARGET_WAITKIND_STOPPED:
5156 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5157 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5158 handle_signal_stop (ecs);
5161 case TARGET_WAITKIND_NO_HISTORY:
5163 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5164 /* Reverse execution: target ran out of history info. */
5166 /* Switch to the stopped thread. */
5167 if (!ptid_equal (ecs->ptid, inferior_ptid))
5168 context_switch (ecs->ptid);
5170 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5172 delete_just_stopped_threads_single_step_breakpoints ();
5173 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5174 observer_notify_no_history ();
5180 /* A wrapper around handle_inferior_event_1, which also makes sure
5181 that all temporary struct value objects that were created during
5182 the handling of the event get deleted at the end. */
5185 handle_inferior_event (struct execution_control_state *ecs)
5187 struct value *mark = value_mark ();
5189 handle_inferior_event_1 (ecs);
5190 /* Purge all temporary values created during the event handling,
5191 as it could be a long time before we return to the command level
5192 where such values would otherwise be purged. */
5193 value_free_to_mark (mark);
5196 /* Restart threads back to what they were trying to do back when we
5197 paused them for an in-line step-over. The EVENT_THREAD thread is
5201 restart_threads (struct thread_info *event_thread)
5203 struct thread_info *tp;
5204 struct thread_info *step_over = NULL;
5206 /* In case the instruction just stepped spawned a new thread. */
5207 update_thread_list ();
5209 ALL_NON_EXITED_THREADS (tp)
5211 if (tp == event_thread)
5214 fprintf_unfiltered (gdb_stdlog,
5215 "infrun: restart threads: "
5216 "[%s] is event thread\n",
5217 target_pid_to_str (tp->ptid));
5221 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5224 fprintf_unfiltered (gdb_stdlog,
5225 "infrun: restart threads: "
5226 "[%s] not meant to be running\n",
5227 target_pid_to_str (tp->ptid));
5234 fprintf_unfiltered (gdb_stdlog,
5235 "infrun: restart threads: [%s] resumed\n",
5236 target_pid_to_str (tp->ptid));
5237 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5241 if (thread_is_in_step_over_chain (tp))
5244 fprintf_unfiltered (gdb_stdlog,
5245 "infrun: restart threads: "
5246 "[%s] needs step-over\n",
5247 target_pid_to_str (tp->ptid));
5248 gdb_assert (!tp->resumed);
5253 if (tp->suspend.waitstatus_pending_p)
5256 fprintf_unfiltered (gdb_stdlog,
5257 "infrun: restart threads: "
5258 "[%s] has pending status\n",
5259 target_pid_to_str (tp->ptid));
5264 /* If some thread needs to start a step-over at this point, it
5265 should still be in the step-over queue, and thus skipped
5267 if (thread_still_needs_step_over (tp))
5269 internal_error (__FILE__, __LINE__,
5270 "thread [%s] needs a step-over, but not in "
5271 "step-over queue\n",
5272 target_pid_to_str (tp->ptid));
5275 if (currently_stepping (tp))
5278 fprintf_unfiltered (gdb_stdlog,
5279 "infrun: restart threads: [%s] was stepping\n",
5280 target_pid_to_str (tp->ptid));
5281 keep_going_stepped_thread (tp);
5285 struct execution_control_state ecss;
5286 struct execution_control_state *ecs = &ecss;
5289 fprintf_unfiltered (gdb_stdlog,
5290 "infrun: restart threads: [%s] continuing\n",
5291 target_pid_to_str (tp->ptid));
5292 reset_ecs (ecs, tp);
5293 switch_to_thread (tp->ptid);
5294 keep_going_pass_signal (ecs);
5299 /* Callback for iterate_over_threads. Find a resumed thread that has
5300 a pending waitstatus. */
5303 resumed_thread_with_pending_status (struct thread_info *tp,
5307 && tp->suspend.waitstatus_pending_p);
5310 /* Called when we get an event that may finish an in-line or
5311 out-of-line (displaced stepping) step-over started previously.
5312 Return true if the event is processed and we should go back to the
5313 event loop; false if the caller should continue processing the
5317 finish_step_over (struct execution_control_state *ecs)
5319 int had_step_over_info;
5321 displaced_step_fixup (ecs->ptid,
5322 ecs->event_thread->suspend.stop_signal);
5324 had_step_over_info = step_over_info_valid_p ();
5326 if (had_step_over_info)
5328 /* If we're stepping over a breakpoint with all threads locked,
5329 then only the thread that was stepped should be reporting
5331 gdb_assert (ecs->event_thread->control.trap_expected);
5333 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5334 clear_step_over_info ();
5337 if (!target_is_non_stop_p ())
5340 /* Start a new step-over in another thread if there's one that
5344 /* If we were stepping over a breakpoint before, and haven't started
5345 a new in-line step-over sequence, then restart all other threads
5346 (except the event thread). We can't do this in all-stop, as then
5347 e.g., we wouldn't be able to issue any other remote packet until
5348 these other threads stop. */
5349 if (had_step_over_info && !step_over_info_valid_p ())
5351 struct thread_info *pending;
5353 /* If we only have threads with pending statuses, the restart
5354 below won't restart any thread and so nothing re-inserts the
5355 breakpoint we just stepped over. But we need it inserted
5356 when we later process the pending events, otherwise if
5357 another thread has a pending event for this breakpoint too,
5358 we'd discard its event (because the breakpoint that
5359 originally caused the event was no longer inserted). */
5360 context_switch (ecs->ptid);
5361 insert_breakpoints ();
5363 restart_threads (ecs->event_thread);
5365 /* If we have events pending, go through handle_inferior_event
5366 again, picking up a pending event at random. This avoids
5367 thread starvation. */
5369 /* But not if we just stepped over a watchpoint in order to let
5370 the instruction execute so we can evaluate its expression.
5371 The set of watchpoints that triggered is recorded in the
5372 breakpoint objects themselves (see bp->watchpoint_triggered).
5373 If we processed another event first, that other event could
5374 clobber this info. */
5375 if (ecs->event_thread->stepping_over_watchpoint)
5378 pending = iterate_over_threads (resumed_thread_with_pending_status,
5380 if (pending != NULL)
5382 struct thread_info *tp = ecs->event_thread;
5383 struct regcache *regcache;
5387 fprintf_unfiltered (gdb_stdlog,
5388 "infrun: found resumed threads with "
5389 "pending events, saving status\n");
5392 gdb_assert (pending != tp);
5394 /* Record the event thread's event for later. */
5395 save_waitstatus (tp, &ecs->ws);
5396 /* This was cleared early, by handle_inferior_event. Set it
5397 so this pending event is considered by
5401 gdb_assert (!tp->executing);
5403 regcache = get_thread_regcache (tp->ptid);
5404 tp->suspend.stop_pc = regcache_read_pc (regcache);
5408 fprintf_unfiltered (gdb_stdlog,
5409 "infrun: saved stop_pc=%s for %s "
5410 "(currently_stepping=%d)\n",
5411 paddress (target_gdbarch (),
5412 tp->suspend.stop_pc),
5413 target_pid_to_str (tp->ptid),
5414 currently_stepping (tp));
5417 /* This in-line step-over finished; clear this so we won't
5418 start a new one. This is what handle_signal_stop would
5419 do, if we returned false. */
5420 tp->stepping_over_breakpoint = 0;
5422 /* Wake up the event loop again. */
5423 mark_async_event_handler (infrun_async_inferior_event_token);
5425 prepare_to_wait (ecs);
5433 /* Come here when the program has stopped with a signal. */
5436 handle_signal_stop (struct execution_control_state *ecs)
5438 struct frame_info *frame;
5439 struct gdbarch *gdbarch;
5440 int stopped_by_watchpoint;
5441 enum stop_kind stop_soon;
5444 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5446 /* Do we need to clean up the state of a thread that has
5447 completed a displaced single-step? (Doing so usually affects
5448 the PC, so do it here, before we set stop_pc.) */
5449 if (finish_step_over (ecs))
5452 /* If we either finished a single-step or hit a breakpoint, but
5453 the user wanted this thread to be stopped, pretend we got a
5454 SIG0 (generic unsignaled stop). */
5455 if (ecs->event_thread->stop_requested
5456 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5457 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5459 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5463 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5464 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5465 struct cleanup *old_chain = save_inferior_ptid ();
5467 inferior_ptid = ecs->ptid;
5469 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5470 paddress (gdbarch, stop_pc));
5471 if (target_stopped_by_watchpoint ())
5475 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5477 if (target_stopped_data_address (¤t_target, &addr))
5478 fprintf_unfiltered (gdb_stdlog,
5479 "infrun: stopped data address = %s\n",
5480 paddress (gdbarch, addr));
5482 fprintf_unfiltered (gdb_stdlog,
5483 "infrun: (no data address available)\n");
5486 do_cleanups (old_chain);
5489 /* This is originated from start_remote(), start_inferior() and
5490 shared libraries hook functions. */
5491 stop_soon = get_inferior_stop_soon (ecs->ptid);
5492 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5494 if (!ptid_equal (ecs->ptid, inferior_ptid))
5495 context_switch (ecs->ptid);
5497 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5498 stop_print_frame = 1;
5503 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5506 if (!ptid_equal (ecs->ptid, inferior_ptid))
5507 context_switch (ecs->ptid);
5509 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5510 stop_print_frame = 0;
5515 /* This originates from attach_command(). We need to overwrite
5516 the stop_signal here, because some kernels don't ignore a
5517 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5518 See more comments in inferior.h. On the other hand, if we
5519 get a non-SIGSTOP, report it to the user - assume the backend
5520 will handle the SIGSTOP if it should show up later.
5522 Also consider that the attach is complete when we see a
5523 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5524 target extended-remote report it instead of a SIGSTOP
5525 (e.g. gdbserver). We already rely on SIGTRAP being our
5526 signal, so this is no exception.
5528 Also consider that the attach is complete when we see a
5529 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5530 the target to stop all threads of the inferior, in case the
5531 low level attach operation doesn't stop them implicitly. If
5532 they weren't stopped implicitly, then the stub will report a
5533 GDB_SIGNAL_0, meaning: stopped for no particular reason
5534 other than GDB's request. */
5535 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5536 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5537 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5538 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5540 stop_print_frame = 1;
5542 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5546 /* See if something interesting happened to the non-current thread. If
5547 so, then switch to that thread. */
5548 if (!ptid_equal (ecs->ptid, inferior_ptid))
5551 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5553 context_switch (ecs->ptid);
5555 if (deprecated_context_hook)
5556 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
5559 /* At this point, get hold of the now-current thread's frame. */
5560 frame = get_current_frame ();
5561 gdbarch = get_frame_arch (frame);
5563 /* Pull the single step breakpoints out of the target. */
5564 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5566 struct regcache *regcache;
5567 struct address_space *aspace;
5570 regcache = get_thread_regcache (ecs->ptid);
5571 aspace = get_regcache_aspace (regcache);
5572 pc = regcache_read_pc (regcache);
5574 /* However, before doing so, if this single-step breakpoint was
5575 actually for another thread, set this thread up for moving
5577 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5580 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5584 fprintf_unfiltered (gdb_stdlog,
5585 "infrun: [%s] hit another thread's "
5586 "single-step breakpoint\n",
5587 target_pid_to_str (ecs->ptid));
5589 ecs->hit_singlestep_breakpoint = 1;
5596 fprintf_unfiltered (gdb_stdlog,
5597 "infrun: [%s] hit its "
5598 "single-step breakpoint\n",
5599 target_pid_to_str (ecs->ptid));
5603 delete_just_stopped_threads_single_step_breakpoints ();
5605 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5606 && ecs->event_thread->control.trap_expected
5607 && ecs->event_thread->stepping_over_watchpoint)
5608 stopped_by_watchpoint = 0;
5610 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5612 /* If necessary, step over this watchpoint. We'll be back to display
5614 if (stopped_by_watchpoint
5615 && (target_have_steppable_watchpoint
5616 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5618 /* At this point, we are stopped at an instruction which has
5619 attempted to write to a piece of memory under control of
5620 a watchpoint. The instruction hasn't actually executed
5621 yet. If we were to evaluate the watchpoint expression
5622 now, we would get the old value, and therefore no change
5623 would seem to have occurred.
5625 In order to make watchpoints work `right', we really need
5626 to complete the memory write, and then evaluate the
5627 watchpoint expression. We do this by single-stepping the
5630 It may not be necessary to disable the watchpoint to step over
5631 it. For example, the PA can (with some kernel cooperation)
5632 single step over a watchpoint without disabling the watchpoint.
5634 It is far more common to need to disable a watchpoint to step
5635 the inferior over it. If we have non-steppable watchpoints,
5636 we must disable the current watchpoint; it's simplest to
5637 disable all watchpoints.
5639 Any breakpoint at PC must also be stepped over -- if there's
5640 one, it will have already triggered before the watchpoint
5641 triggered, and we either already reported it to the user, or
5642 it didn't cause a stop and we called keep_going. In either
5643 case, if there was a breakpoint at PC, we must be trying to
5645 ecs->event_thread->stepping_over_watchpoint = 1;
5650 ecs->event_thread->stepping_over_breakpoint = 0;
5651 ecs->event_thread->stepping_over_watchpoint = 0;
5652 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5653 ecs->event_thread->control.stop_step = 0;
5654 stop_print_frame = 1;
5655 stopped_by_random_signal = 0;
5657 /* Hide inlined functions starting here, unless we just performed stepi or
5658 nexti. After stepi and nexti, always show the innermost frame (not any
5659 inline function call sites). */
5660 if (ecs->event_thread->control.step_range_end != 1)
5662 struct address_space *aspace =
5663 get_regcache_aspace (get_thread_regcache (ecs->ptid));
5665 /* skip_inline_frames is expensive, so we avoid it if we can
5666 determine that the address is one where functions cannot have
5667 been inlined. This improves performance with inferiors that
5668 load a lot of shared libraries, because the solib event
5669 breakpoint is defined as the address of a function (i.e. not
5670 inline). Note that we have to check the previous PC as well
5671 as the current one to catch cases when we have just
5672 single-stepped off a breakpoint prior to reinstating it.
5673 Note that we're assuming that the code we single-step to is
5674 not inline, but that's not definitive: there's nothing
5675 preventing the event breakpoint function from containing
5676 inlined code, and the single-step ending up there. If the
5677 user had set a breakpoint on that inlined code, the missing
5678 skip_inline_frames call would break things. Fortunately
5679 that's an extremely unlikely scenario. */
5680 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5681 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5682 && ecs->event_thread->control.trap_expected
5683 && pc_at_non_inline_function (aspace,
5684 ecs->event_thread->prev_pc,
5687 skip_inline_frames (ecs->ptid);
5689 /* Re-fetch current thread's frame in case that invalidated
5691 frame = get_current_frame ();
5692 gdbarch = get_frame_arch (frame);
5696 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5697 && ecs->event_thread->control.trap_expected
5698 && gdbarch_single_step_through_delay_p (gdbarch)
5699 && currently_stepping (ecs->event_thread))
5701 /* We're trying to step off a breakpoint. Turns out that we're
5702 also on an instruction that needs to be stepped multiple
5703 times before it's been fully executing. E.g., architectures
5704 with a delay slot. It needs to be stepped twice, once for
5705 the instruction and once for the delay slot. */
5706 int step_through_delay
5707 = gdbarch_single_step_through_delay (gdbarch, frame);
5709 if (debug_infrun && step_through_delay)
5710 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5711 if (ecs->event_thread->control.step_range_end == 0
5712 && step_through_delay)
5714 /* The user issued a continue when stopped at a breakpoint.
5715 Set up for another trap and get out of here. */
5716 ecs->event_thread->stepping_over_breakpoint = 1;
5720 else if (step_through_delay)
5722 /* The user issued a step when stopped at a breakpoint.
5723 Maybe we should stop, maybe we should not - the delay
5724 slot *might* correspond to a line of source. In any
5725 case, don't decide that here, just set
5726 ecs->stepping_over_breakpoint, making sure we
5727 single-step again before breakpoints are re-inserted. */
5728 ecs->event_thread->stepping_over_breakpoint = 1;
5732 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5733 handles this event. */
5734 ecs->event_thread->control.stop_bpstat
5735 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5736 stop_pc, ecs->ptid, &ecs->ws);
5738 /* Following in case break condition called a
5740 stop_print_frame = 1;
5742 /* This is where we handle "moribund" watchpoints. Unlike
5743 software breakpoints traps, hardware watchpoint traps are
5744 always distinguishable from random traps. If no high-level
5745 watchpoint is associated with the reported stop data address
5746 anymore, then the bpstat does not explain the signal ---
5747 simply make sure to ignore it if `stopped_by_watchpoint' is
5751 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5752 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5754 && stopped_by_watchpoint)
5755 fprintf_unfiltered (gdb_stdlog,
5756 "infrun: no user watchpoint explains "
5757 "watchpoint SIGTRAP, ignoring\n");
5759 /* NOTE: cagney/2003-03-29: These checks for a random signal
5760 at one stage in the past included checks for an inferior
5761 function call's call dummy's return breakpoint. The original
5762 comment, that went with the test, read:
5764 ``End of a stack dummy. Some systems (e.g. Sony news) give
5765 another signal besides SIGTRAP, so check here as well as
5768 If someone ever tries to get call dummys on a
5769 non-executable stack to work (where the target would stop
5770 with something like a SIGSEGV), then those tests might need
5771 to be re-instated. Given, however, that the tests were only
5772 enabled when momentary breakpoints were not being used, I
5773 suspect that it won't be the case.
5775 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5776 be necessary for call dummies on a non-executable stack on
5779 /* See if the breakpoints module can explain the signal. */
5781 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5782 ecs->event_thread->suspend.stop_signal);
5784 /* Maybe this was a trap for a software breakpoint that has since
5786 if (random_signal && target_stopped_by_sw_breakpoint ())
5788 if (program_breakpoint_here_p (gdbarch, stop_pc))
5790 struct regcache *regcache;
5793 /* Re-adjust PC to what the program would see if GDB was not
5795 regcache = get_thread_regcache (ecs->event_thread->ptid);
5796 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5799 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
5801 if (record_full_is_used ())
5802 record_full_gdb_operation_disable_set ();
5804 regcache_write_pc (regcache, stop_pc + decr_pc);
5806 do_cleanups (old_cleanups);
5811 /* A delayed software breakpoint event. Ignore the trap. */
5813 fprintf_unfiltered (gdb_stdlog,
5814 "infrun: delayed software breakpoint "
5815 "trap, ignoring\n");
5820 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5821 has since been removed. */
5822 if (random_signal && target_stopped_by_hw_breakpoint ())
5824 /* A delayed hardware breakpoint event. Ignore the trap. */
5826 fprintf_unfiltered (gdb_stdlog,
5827 "infrun: delayed hardware breakpoint/watchpoint "
5828 "trap, ignoring\n");
5832 /* If not, perhaps stepping/nexting can. */
5834 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5835 && currently_stepping (ecs->event_thread));
5837 /* Perhaps the thread hit a single-step breakpoint of _another_
5838 thread. Single-step breakpoints are transparent to the
5839 breakpoints module. */
5841 random_signal = !ecs->hit_singlestep_breakpoint;
5843 /* No? Perhaps we got a moribund watchpoint. */
5845 random_signal = !stopped_by_watchpoint;
5847 /* For the program's own signals, act according to
5848 the signal handling tables. */
5852 /* Signal not for debugging purposes. */
5853 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5854 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5857 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5858 gdb_signal_to_symbol_string (stop_signal));
5860 stopped_by_random_signal = 1;
5862 /* Always stop on signals if we're either just gaining control
5863 of the program, or the user explicitly requested this thread
5864 to remain stopped. */
5865 if (stop_soon != NO_STOP_QUIETLY
5866 || ecs->event_thread->stop_requested
5868 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5874 /* Notify observers the signal has "handle print" set. Note we
5875 returned early above if stopping; normal_stop handles the
5876 printing in that case. */
5877 if (signal_print[ecs->event_thread->suspend.stop_signal])
5879 /* The signal table tells us to print about this signal. */
5880 target_terminal_ours_for_output ();
5881 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
5882 target_terminal_inferior ();
5885 /* Clear the signal if it should not be passed. */
5886 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5887 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5889 if (ecs->event_thread->prev_pc == stop_pc
5890 && ecs->event_thread->control.trap_expected
5891 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5895 /* We were just starting a new sequence, attempting to
5896 single-step off of a breakpoint and expecting a SIGTRAP.
5897 Instead this signal arrives. This signal will take us out
5898 of the stepping range so GDB needs to remember to, when
5899 the signal handler returns, resume stepping off that
5901 /* To simplify things, "continue" is forced to use the same
5902 code paths as single-step - set a breakpoint at the
5903 signal return address and then, once hit, step off that
5906 fprintf_unfiltered (gdb_stdlog,
5907 "infrun: signal arrived while stepping over "
5910 was_in_line = step_over_info_valid_p ();
5911 clear_step_over_info ();
5912 insert_hp_step_resume_breakpoint_at_frame (frame);
5913 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5914 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5915 ecs->event_thread->control.trap_expected = 0;
5917 if (target_is_non_stop_p ())
5919 /* Either "set non-stop" is "on", or the target is
5920 always in non-stop mode. In this case, we have a bit
5921 more work to do. Resume the current thread, and if
5922 we had paused all threads, restart them while the
5923 signal handler runs. */
5928 restart_threads (ecs->event_thread);
5930 else if (debug_infrun)
5932 fprintf_unfiltered (gdb_stdlog,
5933 "infrun: no need to restart threads\n");
5938 /* If we were nexting/stepping some other thread, switch to
5939 it, so that we don't continue it, losing control. */
5940 if (!switch_back_to_stepped_thread (ecs))
5945 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5946 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
5947 || ecs->event_thread->control.step_range_end == 1)
5948 && frame_id_eq (get_stack_frame_id (frame),
5949 ecs->event_thread->control.step_stack_frame_id)
5950 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5952 /* The inferior is about to take a signal that will take it
5953 out of the single step range. Set a breakpoint at the
5954 current PC (which is presumably where the signal handler
5955 will eventually return) and then allow the inferior to
5958 Note that this is only needed for a signal delivered
5959 while in the single-step range. Nested signals aren't a
5960 problem as they eventually all return. */
5962 fprintf_unfiltered (gdb_stdlog,
5963 "infrun: signal may take us out of "
5964 "single-step range\n");
5966 clear_step_over_info ();
5967 insert_hp_step_resume_breakpoint_at_frame (frame);
5968 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5969 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5970 ecs->event_thread->control.trap_expected = 0;
5975 /* Note: step_resume_breakpoint may be non-NULL. This occures
5976 when either there's a nested signal, or when there's a
5977 pending signal enabled just as the signal handler returns
5978 (leaving the inferior at the step-resume-breakpoint without
5979 actually executing it). Either way continue until the
5980 breakpoint is really hit. */
5982 if (!switch_back_to_stepped_thread (ecs))
5985 fprintf_unfiltered (gdb_stdlog,
5986 "infrun: random signal, keep going\n");
5993 process_event_stop_test (ecs);
5996 /* Come here when we've got some debug event / signal we can explain
5997 (IOW, not a random signal), and test whether it should cause a
5998 stop, or whether we should resume the inferior (transparently).
5999 E.g., could be a breakpoint whose condition evaluates false; we
6000 could be still stepping within the line; etc. */
6003 process_event_stop_test (struct execution_control_state *ecs)
6005 struct symtab_and_line stop_pc_sal;
6006 struct frame_info *frame;
6007 struct gdbarch *gdbarch;
6008 CORE_ADDR jmp_buf_pc;
6009 struct bpstat_what what;
6011 /* Handle cases caused by hitting a breakpoint. */
6013 frame = get_current_frame ();
6014 gdbarch = get_frame_arch (frame);
6016 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6018 if (what.call_dummy)
6020 stop_stack_dummy = what.call_dummy;
6023 /* A few breakpoint types have callbacks associated (e.g.,
6024 bp_jit_event). Run them now. */
6025 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6027 /* If we hit an internal event that triggers symbol changes, the
6028 current frame will be invalidated within bpstat_what (e.g., if we
6029 hit an internal solib event). Re-fetch it. */
6030 frame = get_current_frame ();
6031 gdbarch = get_frame_arch (frame);
6033 switch (what.main_action)
6035 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6036 /* If we hit the breakpoint at longjmp while stepping, we
6037 install a momentary breakpoint at the target of the
6041 fprintf_unfiltered (gdb_stdlog,
6042 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6044 ecs->event_thread->stepping_over_breakpoint = 1;
6046 if (what.is_longjmp)
6048 struct value *arg_value;
6050 /* If we set the longjmp breakpoint via a SystemTap probe,
6051 then use it to extract the arguments. The destination PC
6052 is the third argument to the probe. */
6053 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6056 jmp_buf_pc = value_as_address (arg_value);
6057 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6059 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6060 || !gdbarch_get_longjmp_target (gdbarch,
6061 frame, &jmp_buf_pc))
6064 fprintf_unfiltered (gdb_stdlog,
6065 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6066 "(!gdbarch_get_longjmp_target)\n");
6071 /* Insert a breakpoint at resume address. */
6072 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6075 check_exception_resume (ecs, frame);
6079 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6081 struct frame_info *init_frame;
6083 /* There are several cases to consider.
6085 1. The initiating frame no longer exists. In this case we
6086 must stop, because the exception or longjmp has gone too
6089 2. The initiating frame exists, and is the same as the
6090 current frame. We stop, because the exception or longjmp
6093 3. The initiating frame exists and is different from the
6094 current frame. This means the exception or longjmp has
6095 been caught beneath the initiating frame, so keep going.
6097 4. longjmp breakpoint has been placed just to protect
6098 against stale dummy frames and user is not interested in
6099 stopping around longjmps. */
6102 fprintf_unfiltered (gdb_stdlog,
6103 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6105 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6107 delete_exception_resume_breakpoint (ecs->event_thread);
6109 if (what.is_longjmp)
6111 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6113 if (!frame_id_p (ecs->event_thread->initiating_frame))
6121 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6125 struct frame_id current_id
6126 = get_frame_id (get_current_frame ());
6127 if (frame_id_eq (current_id,
6128 ecs->event_thread->initiating_frame))
6130 /* Case 2. Fall through. */
6140 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6142 delete_step_resume_breakpoint (ecs->event_thread);
6144 end_stepping_range (ecs);
6148 case BPSTAT_WHAT_SINGLE:
6150 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6151 ecs->event_thread->stepping_over_breakpoint = 1;
6152 /* Still need to check other stuff, at least the case where we
6153 are stepping and step out of the right range. */
6156 case BPSTAT_WHAT_STEP_RESUME:
6158 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6160 delete_step_resume_breakpoint (ecs->event_thread);
6161 if (ecs->event_thread->control.proceed_to_finish
6162 && execution_direction == EXEC_REVERSE)
6164 struct thread_info *tp = ecs->event_thread;
6166 /* We are finishing a function in reverse, and just hit the
6167 step-resume breakpoint at the start address of the
6168 function, and we're almost there -- just need to back up
6169 by one more single-step, which should take us back to the
6171 tp->control.step_range_start = tp->control.step_range_end = 1;
6175 fill_in_stop_func (gdbarch, ecs);
6176 if (stop_pc == ecs->stop_func_start
6177 && execution_direction == EXEC_REVERSE)
6179 /* We are stepping over a function call in reverse, and just
6180 hit the step-resume breakpoint at the start address of
6181 the function. Go back to single-stepping, which should
6182 take us back to the function call. */
6183 ecs->event_thread->stepping_over_breakpoint = 1;
6189 case BPSTAT_WHAT_STOP_NOISY:
6191 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6192 stop_print_frame = 1;
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;
6202 case BPSTAT_WHAT_STOP_SILENT:
6204 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6205 stop_print_frame = 0;
6207 /* Assume the thread stopped for a breapoint. We'll still check
6208 whether a/the breakpoint is there when the thread is next
6210 ecs->event_thread->stepping_over_breakpoint = 1;
6214 case BPSTAT_WHAT_HP_STEP_RESUME:
6216 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6218 delete_step_resume_breakpoint (ecs->event_thread);
6219 if (ecs->event_thread->step_after_step_resume_breakpoint)
6221 /* Back when the step-resume breakpoint was inserted, we
6222 were trying to single-step off a breakpoint. Go back to
6224 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6225 ecs->event_thread->stepping_over_breakpoint = 1;
6231 case BPSTAT_WHAT_KEEP_CHECKING:
6235 /* If we stepped a permanent breakpoint and we had a high priority
6236 step-resume breakpoint for the address we stepped, but we didn't
6237 hit it, then we must have stepped into the signal handler. The
6238 step-resume was only necessary to catch the case of _not_
6239 stepping into the handler, so delete it, and fall through to
6240 checking whether the step finished. */
6241 if (ecs->event_thread->stepped_breakpoint)
6243 struct breakpoint *sr_bp
6244 = ecs->event_thread->control.step_resume_breakpoint;
6247 && sr_bp->loc->permanent
6248 && sr_bp->type == bp_hp_step_resume
6249 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6252 fprintf_unfiltered (gdb_stdlog,
6253 "infrun: stepped permanent breakpoint, stopped in "
6255 delete_step_resume_breakpoint (ecs->event_thread);
6256 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6260 /* We come here if we hit a breakpoint but should not stop for it.
6261 Possibly we also were stepping and should stop for that. So fall
6262 through and test for stepping. But, if not stepping, do not
6265 /* In all-stop mode, if we're currently stepping but have stopped in
6266 some other thread, we need to switch back to the stepped thread. */
6267 if (switch_back_to_stepped_thread (ecs))
6270 if (ecs->event_thread->control.step_resume_breakpoint)
6273 fprintf_unfiltered (gdb_stdlog,
6274 "infrun: step-resume breakpoint is inserted\n");
6276 /* Having a step-resume breakpoint overrides anything
6277 else having to do with stepping commands until
6278 that breakpoint is reached. */
6283 if (ecs->event_thread->control.step_range_end == 0)
6286 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6287 /* Likewise if we aren't even stepping. */
6292 /* Re-fetch current thread's frame in case the code above caused
6293 the frame cache to be re-initialized, making our FRAME variable
6294 a dangling pointer. */
6295 frame = get_current_frame ();
6296 gdbarch = get_frame_arch (frame);
6297 fill_in_stop_func (gdbarch, ecs);
6299 /* If stepping through a line, keep going if still within it.
6301 Note that step_range_end is the address of the first instruction
6302 beyond the step range, and NOT the address of the last instruction
6305 Note also that during reverse execution, we may be stepping
6306 through a function epilogue and therefore must detect when
6307 the current-frame changes in the middle of a line. */
6309 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6310 && (execution_direction != EXEC_REVERSE
6311 || frame_id_eq (get_frame_id (frame),
6312 ecs->event_thread->control.step_frame_id)))
6316 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6317 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6318 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6320 /* Tentatively re-enable range stepping; `resume' disables it if
6321 necessary (e.g., if we're stepping over a breakpoint or we
6322 have software watchpoints). */
6323 ecs->event_thread->control.may_range_step = 1;
6325 /* When stepping backward, stop at beginning of line range
6326 (unless it's the function entry point, in which case
6327 keep going back to the call point). */
6328 if (stop_pc == ecs->event_thread->control.step_range_start
6329 && stop_pc != ecs->stop_func_start
6330 && execution_direction == EXEC_REVERSE)
6331 end_stepping_range (ecs);
6338 /* We stepped out of the stepping range. */
6340 /* If we are stepping at the source level and entered the runtime
6341 loader dynamic symbol resolution code...
6343 EXEC_FORWARD: we keep on single stepping until we exit the run
6344 time loader code and reach the callee's address.
6346 EXEC_REVERSE: we've already executed the callee (backward), and
6347 the runtime loader code is handled just like any other
6348 undebuggable function call. Now we need only keep stepping
6349 backward through the trampoline code, and that's handled further
6350 down, so there is nothing for us to do here. */
6352 if (execution_direction != EXEC_REVERSE
6353 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6354 && in_solib_dynsym_resolve_code (stop_pc))
6356 CORE_ADDR pc_after_resolver =
6357 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6360 fprintf_unfiltered (gdb_stdlog,
6361 "infrun: stepped into dynsym resolve code\n");
6363 if (pc_after_resolver)
6365 /* Set up a step-resume breakpoint at the address
6366 indicated by SKIP_SOLIB_RESOLVER. */
6367 struct symtab_and_line sr_sal;
6370 sr_sal.pc = pc_after_resolver;
6371 sr_sal.pspace = get_frame_program_space (frame);
6373 insert_step_resume_breakpoint_at_sal (gdbarch,
6374 sr_sal, null_frame_id);
6381 if (ecs->event_thread->control.step_range_end != 1
6382 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6383 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6384 && get_frame_type (frame) == SIGTRAMP_FRAME)
6387 fprintf_unfiltered (gdb_stdlog,
6388 "infrun: stepped into signal trampoline\n");
6389 /* The inferior, while doing a "step" or "next", has ended up in
6390 a signal trampoline (either by a signal being delivered or by
6391 the signal handler returning). Just single-step until the
6392 inferior leaves the trampoline (either by calling the handler
6398 /* If we're in the return path from a shared library trampoline,
6399 we want to proceed through the trampoline when stepping. */
6400 /* macro/2012-04-25: This needs to come before the subroutine
6401 call check below as on some targets return trampolines look
6402 like subroutine calls (MIPS16 return thunks). */
6403 if (gdbarch_in_solib_return_trampoline (gdbarch,
6404 stop_pc, ecs->stop_func_name)
6405 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6407 /* Determine where this trampoline returns. */
6408 CORE_ADDR real_stop_pc;
6410 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6413 fprintf_unfiltered (gdb_stdlog,
6414 "infrun: stepped into solib return tramp\n");
6416 /* Only proceed through if we know where it's going. */
6419 /* And put the step-breakpoint there and go until there. */
6420 struct symtab_and_line sr_sal;
6422 init_sal (&sr_sal); /* initialize to zeroes */
6423 sr_sal.pc = real_stop_pc;
6424 sr_sal.section = find_pc_overlay (sr_sal.pc);
6425 sr_sal.pspace = get_frame_program_space (frame);
6427 /* Do not specify what the fp should be when we stop since
6428 on some machines the prologue is where the new fp value
6430 insert_step_resume_breakpoint_at_sal (gdbarch,
6431 sr_sal, null_frame_id);
6433 /* Restart without fiddling with the step ranges or
6440 /* Check for subroutine calls. The check for the current frame
6441 equalling the step ID is not necessary - the check of the
6442 previous frame's ID is sufficient - but it is a common case and
6443 cheaper than checking the previous frame's ID.
6445 NOTE: frame_id_eq will never report two invalid frame IDs as
6446 being equal, so to get into this block, both the current and
6447 previous frame must have valid frame IDs. */
6448 /* The outer_frame_id check is a heuristic to detect stepping
6449 through startup code. If we step over an instruction which
6450 sets the stack pointer from an invalid value to a valid value,
6451 we may detect that as a subroutine call from the mythical
6452 "outermost" function. This could be fixed by marking
6453 outermost frames as !stack_p,code_p,special_p. Then the
6454 initial outermost frame, before sp was valid, would
6455 have code_addr == &_start. See the comment in frame_id_eq
6457 if (!frame_id_eq (get_stack_frame_id (frame),
6458 ecs->event_thread->control.step_stack_frame_id)
6459 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6460 ecs->event_thread->control.step_stack_frame_id)
6461 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6463 || (ecs->event_thread->control.step_start_function
6464 != find_pc_function (stop_pc)))))
6466 CORE_ADDR real_stop_pc;
6469 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6471 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6473 /* I presume that step_over_calls is only 0 when we're
6474 supposed to be stepping at the assembly language level
6475 ("stepi"). Just stop. */
6476 /* And this works the same backward as frontward. MVS */
6477 end_stepping_range (ecs);
6481 /* Reverse stepping through solib trampolines. */
6483 if (execution_direction == EXEC_REVERSE
6484 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6485 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6486 || (ecs->stop_func_start == 0
6487 && in_solib_dynsym_resolve_code (stop_pc))))
6489 /* Any solib trampoline code can be handled in reverse
6490 by simply continuing to single-step. We have already
6491 executed the solib function (backwards), and a few
6492 steps will take us back through the trampoline to the
6498 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6500 /* We're doing a "next".
6502 Normal (forward) execution: set a breakpoint at the
6503 callee's return address (the address at which the caller
6506 Reverse (backward) execution. set the step-resume
6507 breakpoint at the start of the function that we just
6508 stepped into (backwards), and continue to there. When we
6509 get there, we'll need to single-step back to the caller. */
6511 if (execution_direction == EXEC_REVERSE)
6513 /* If we're already at the start of the function, we've either
6514 just stepped backward into a single instruction function,
6515 or stepped back out of a signal handler to the first instruction
6516 of the function. Just keep going, which will single-step back
6518 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6520 struct symtab_and_line sr_sal;
6522 /* Normal function call return (static or dynamic). */
6524 sr_sal.pc = ecs->stop_func_start;
6525 sr_sal.pspace = get_frame_program_space (frame);
6526 insert_step_resume_breakpoint_at_sal (gdbarch,
6527 sr_sal, null_frame_id);
6531 insert_step_resume_breakpoint_at_caller (frame);
6537 /* If we are in a function call trampoline (a stub between the
6538 calling routine and the real function), locate the real
6539 function. That's what tells us (a) whether we want to step
6540 into it at all, and (b) what prologue we want to run to the
6541 end of, if we do step into it. */
6542 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6543 if (real_stop_pc == 0)
6544 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6545 if (real_stop_pc != 0)
6546 ecs->stop_func_start = real_stop_pc;
6548 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6550 struct symtab_and_line sr_sal;
6553 sr_sal.pc = ecs->stop_func_start;
6554 sr_sal.pspace = get_frame_program_space (frame);
6556 insert_step_resume_breakpoint_at_sal (gdbarch,
6557 sr_sal, null_frame_id);
6562 /* If we have line number information for the function we are
6563 thinking of stepping into and the function isn't on the skip
6566 If there are several symtabs at that PC (e.g. with include
6567 files), just want to know whether *any* of them have line
6568 numbers. find_pc_line handles this. */
6570 struct symtab_and_line tmp_sal;
6572 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6573 if (tmp_sal.line != 0
6574 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6577 if (execution_direction == EXEC_REVERSE)
6578 handle_step_into_function_backward (gdbarch, ecs);
6580 handle_step_into_function (gdbarch, ecs);
6585 /* If we have no line number and the step-stop-if-no-debug is
6586 set, we stop the step so that the user has a chance to switch
6587 in assembly mode. */
6588 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6589 && step_stop_if_no_debug)
6591 end_stepping_range (ecs);
6595 if (execution_direction == EXEC_REVERSE)
6597 /* If we're already at the start of the function, we've either just
6598 stepped backward into a single instruction function without line
6599 number info, or stepped back out of a signal handler to the first
6600 instruction of the function without line number info. Just keep
6601 going, which will single-step back to the caller. */
6602 if (ecs->stop_func_start != stop_pc)
6604 /* Set a breakpoint at callee's start address.
6605 From there we can step once and be back in the caller. */
6606 struct symtab_and_line sr_sal;
6609 sr_sal.pc = ecs->stop_func_start;
6610 sr_sal.pspace = get_frame_program_space (frame);
6611 insert_step_resume_breakpoint_at_sal (gdbarch,
6612 sr_sal, null_frame_id);
6616 /* Set a breakpoint at callee's return address (the address
6617 at which the caller will resume). */
6618 insert_step_resume_breakpoint_at_caller (frame);
6624 /* Reverse stepping through solib trampolines. */
6626 if (execution_direction == EXEC_REVERSE
6627 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6629 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6630 || (ecs->stop_func_start == 0
6631 && in_solib_dynsym_resolve_code (stop_pc)))
6633 /* Any solib trampoline code can be handled in reverse
6634 by simply continuing to single-step. We have already
6635 executed the solib function (backwards), and a few
6636 steps will take us back through the trampoline to the
6641 else if (in_solib_dynsym_resolve_code (stop_pc))
6643 /* Stepped backward into the solib dynsym resolver.
6644 Set a breakpoint at its start and continue, then
6645 one more step will take us out. */
6646 struct symtab_and_line sr_sal;
6649 sr_sal.pc = ecs->stop_func_start;
6650 sr_sal.pspace = get_frame_program_space (frame);
6651 insert_step_resume_breakpoint_at_sal (gdbarch,
6652 sr_sal, null_frame_id);
6658 stop_pc_sal = find_pc_line (stop_pc, 0);
6660 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6661 the trampoline processing logic, however, there are some trampolines
6662 that have no names, so we should do trampoline handling first. */
6663 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6664 && ecs->stop_func_name == NULL
6665 && stop_pc_sal.line == 0)
6668 fprintf_unfiltered (gdb_stdlog,
6669 "infrun: stepped into undebuggable function\n");
6671 /* The inferior just stepped into, or returned to, an
6672 undebuggable function (where there is no debugging information
6673 and no line number corresponding to the address where the
6674 inferior stopped). Since we want to skip this kind of code,
6675 we keep going until the inferior returns from this
6676 function - unless the user has asked us not to (via
6677 set step-mode) or we no longer know how to get back
6678 to the call site. */
6679 if (step_stop_if_no_debug
6680 || !frame_id_p (frame_unwind_caller_id (frame)))
6682 /* If we have no line number and the step-stop-if-no-debug
6683 is set, we stop the step so that the user has a chance to
6684 switch in assembly mode. */
6685 end_stepping_range (ecs);
6690 /* Set a breakpoint at callee's return address (the address
6691 at which the caller will resume). */
6692 insert_step_resume_breakpoint_at_caller (frame);
6698 if (ecs->event_thread->control.step_range_end == 1)
6700 /* It is stepi or nexti. We always want to stop stepping after
6703 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6704 end_stepping_range (ecs);
6708 if (stop_pc_sal.line == 0)
6710 /* We have no line number information. That means to stop
6711 stepping (does this always happen right after one instruction,
6712 when we do "s" in a function with no line numbers,
6713 or can this happen as a result of a return or longjmp?). */
6715 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6716 end_stepping_range (ecs);
6720 /* Look for "calls" to inlined functions, part one. If the inline
6721 frame machinery detected some skipped call sites, we have entered
6722 a new inline function. */
6724 if (frame_id_eq (get_frame_id (get_current_frame ()),
6725 ecs->event_thread->control.step_frame_id)
6726 && inline_skipped_frames (ecs->ptid))
6728 struct symtab_and_line call_sal;
6731 fprintf_unfiltered (gdb_stdlog,
6732 "infrun: stepped into inlined function\n");
6734 find_frame_sal (get_current_frame (), &call_sal);
6736 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6738 /* For "step", we're going to stop. But if the call site
6739 for this inlined function is on the same source line as
6740 we were previously stepping, go down into the function
6741 first. Otherwise stop at the call site. */
6743 if (call_sal.line == ecs->event_thread->current_line
6744 && call_sal.symtab == ecs->event_thread->current_symtab)
6745 step_into_inline_frame (ecs->ptid);
6747 end_stepping_range (ecs);
6752 /* For "next", we should stop at the call site if it is on a
6753 different source line. Otherwise continue through the
6754 inlined function. */
6755 if (call_sal.line == ecs->event_thread->current_line
6756 && call_sal.symtab == ecs->event_thread->current_symtab)
6759 end_stepping_range (ecs);
6764 /* Look for "calls" to inlined functions, part two. If we are still
6765 in the same real function we were stepping through, but we have
6766 to go further up to find the exact frame ID, we are stepping
6767 through a more inlined call beyond its call site. */
6769 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6770 && !frame_id_eq (get_frame_id (get_current_frame ()),
6771 ecs->event_thread->control.step_frame_id)
6772 && stepped_in_from (get_current_frame (),
6773 ecs->event_thread->control.step_frame_id))
6776 fprintf_unfiltered (gdb_stdlog,
6777 "infrun: stepping through inlined function\n");
6779 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6782 end_stepping_range (ecs);
6786 if ((stop_pc == stop_pc_sal.pc)
6787 && (ecs->event_thread->current_line != stop_pc_sal.line
6788 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6790 /* We are at the start of a different line. So stop. Note that
6791 we don't stop if we step into the middle of a different line.
6792 That is said to make things like for (;;) statements work
6795 fprintf_unfiltered (gdb_stdlog,
6796 "infrun: stepped to a different line\n");
6797 end_stepping_range (ecs);
6801 /* We aren't done stepping.
6803 Optimize by setting the stepping range to the line.
6804 (We might not be in the original line, but if we entered a
6805 new line in mid-statement, we continue stepping. This makes
6806 things like for(;;) statements work better.) */
6808 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6809 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6810 ecs->event_thread->control.may_range_step = 1;
6811 set_step_info (frame, stop_pc_sal);
6814 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6818 /* In all-stop mode, if we're currently stepping but have stopped in
6819 some other thread, we may need to switch back to the stepped
6820 thread. Returns true we set the inferior running, false if we left
6821 it stopped (and the event needs further processing). */
6824 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6826 if (!target_is_non_stop_p ())
6828 struct thread_info *tp;
6829 struct thread_info *stepping_thread;
6831 /* If any thread is blocked on some internal breakpoint, and we
6832 simply need to step over that breakpoint to get it going
6833 again, do that first. */
6835 /* However, if we see an event for the stepping thread, then we
6836 know all other threads have been moved past their breakpoints
6837 already. Let the caller check whether the step is finished,
6838 etc., before deciding to move it past a breakpoint. */
6839 if (ecs->event_thread->control.step_range_end != 0)
6842 /* Check if the current thread is blocked on an incomplete
6843 step-over, interrupted by a random signal. */
6844 if (ecs->event_thread->control.trap_expected
6845 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6849 fprintf_unfiltered (gdb_stdlog,
6850 "infrun: need to finish step-over of [%s]\n",
6851 target_pid_to_str (ecs->event_thread->ptid));
6857 /* Check if the current thread is blocked by a single-step
6858 breakpoint of another thread. */
6859 if (ecs->hit_singlestep_breakpoint)
6863 fprintf_unfiltered (gdb_stdlog,
6864 "infrun: need to step [%s] over single-step "
6866 target_pid_to_str (ecs->ptid));
6872 /* If this thread needs yet another step-over (e.g., stepping
6873 through a delay slot), do it first before moving on to
6875 if (thread_still_needs_step_over (ecs->event_thread))
6879 fprintf_unfiltered (gdb_stdlog,
6880 "infrun: thread [%s] still needs step-over\n",
6881 target_pid_to_str (ecs->event_thread->ptid));
6887 /* If scheduler locking applies even if not stepping, there's no
6888 need to walk over threads. Above we've checked whether the
6889 current thread is stepping. If some other thread not the
6890 event thread is stepping, then it must be that scheduler
6891 locking is not in effect. */
6892 if (schedlock_applies (ecs->event_thread))
6895 /* Otherwise, we no longer expect a trap in the current thread.
6896 Clear the trap_expected flag before switching back -- this is
6897 what keep_going does as well, if we call it. */
6898 ecs->event_thread->control.trap_expected = 0;
6900 /* Likewise, clear the signal if it should not be passed. */
6901 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6902 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6904 /* Do all pending step-overs before actually proceeding with
6906 if (start_step_over ())
6908 prepare_to_wait (ecs);
6912 /* Look for the stepping/nexting thread. */
6913 stepping_thread = NULL;
6915 ALL_NON_EXITED_THREADS (tp)
6917 /* Ignore threads of processes the caller is not
6920 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
6923 /* When stepping over a breakpoint, we lock all threads
6924 except the one that needs to move past the breakpoint.
6925 If a non-event thread has this set, the "incomplete
6926 step-over" check above should have caught it earlier. */
6927 if (tp->control.trap_expected)
6929 internal_error (__FILE__, __LINE__,
6930 "[%s] has inconsistent state: "
6931 "trap_expected=%d\n",
6932 target_pid_to_str (tp->ptid),
6933 tp->control.trap_expected);
6936 /* Did we find the stepping thread? */
6937 if (tp->control.step_range_end)
6939 /* Yep. There should only one though. */
6940 gdb_assert (stepping_thread == NULL);
6942 /* The event thread is handled at the top, before we
6944 gdb_assert (tp != ecs->event_thread);
6946 /* If some thread other than the event thread is
6947 stepping, then scheduler locking can't be in effect,
6948 otherwise we wouldn't have resumed the current event
6949 thread in the first place. */
6950 gdb_assert (!schedlock_applies (tp));
6952 stepping_thread = tp;
6956 if (stepping_thread != NULL)
6959 fprintf_unfiltered (gdb_stdlog,
6960 "infrun: switching back to stepped thread\n");
6962 if (keep_going_stepped_thread (stepping_thread))
6964 prepare_to_wait (ecs);
6973 /* Set a previously stepped thread back to stepping. Returns true on
6974 success, false if the resume is not possible (e.g., the thread
6978 keep_going_stepped_thread (struct thread_info *tp)
6980 struct frame_info *frame;
6981 struct gdbarch *gdbarch;
6982 struct execution_control_state ecss;
6983 struct execution_control_state *ecs = &ecss;
6985 /* If the stepping thread exited, then don't try to switch back and
6986 resume it, which could fail in several different ways depending
6987 on the target. Instead, just keep going.
6989 We can find a stepping dead thread in the thread list in two
6992 - The target supports thread exit events, and when the target
6993 tries to delete the thread from the thread list, inferior_ptid
6994 pointed at the exiting thread. In such case, calling
6995 delete_thread does not really remove the thread from the list;
6996 instead, the thread is left listed, with 'exited' state.
6998 - The target's debug interface does not support thread exit
6999 events, and so we have no idea whatsoever if the previously
7000 stepping thread is still alive. For that reason, we need to
7001 synchronously query the target now. */
7003 if (is_exited (tp->ptid)
7004 || !target_thread_alive (tp->ptid))
7007 fprintf_unfiltered (gdb_stdlog,
7008 "infrun: not resuming previously "
7009 "stepped thread, it has vanished\n");
7011 delete_thread (tp->ptid);
7016 fprintf_unfiltered (gdb_stdlog,
7017 "infrun: resuming previously stepped thread\n");
7019 reset_ecs (ecs, tp);
7020 switch_to_thread (tp->ptid);
7022 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7023 frame = get_current_frame ();
7024 gdbarch = get_frame_arch (frame);
7026 /* If the PC of the thread we were trying to single-step has
7027 changed, then that thread has trapped or been signaled, but the
7028 event has not been reported to GDB yet. Re-poll the target
7029 looking for this particular thread's event (i.e. temporarily
7030 enable schedlock) by:
7032 - setting a break at the current PC
7033 - resuming that particular thread, only (by setting trap
7036 This prevents us continuously moving the single-step breakpoint
7037 forward, one instruction at a time, overstepping. */
7039 if (stop_pc != tp->prev_pc)
7044 fprintf_unfiltered (gdb_stdlog,
7045 "infrun: expected thread advanced also (%s -> %s)\n",
7046 paddress (target_gdbarch (), tp->prev_pc),
7047 paddress (target_gdbarch (), stop_pc));
7049 /* Clear the info of the previous step-over, as it's no longer
7050 valid (if the thread was trying to step over a breakpoint, it
7051 has already succeeded). It's what keep_going would do too,
7052 if we called it. Do this before trying to insert the sss
7053 breakpoint, otherwise if we were previously trying to step
7054 over this exact address in another thread, the breakpoint is
7056 clear_step_over_info ();
7057 tp->control.trap_expected = 0;
7059 insert_single_step_breakpoint (get_frame_arch (frame),
7060 get_frame_address_space (frame),
7064 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7065 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7070 fprintf_unfiltered (gdb_stdlog,
7071 "infrun: expected thread still hasn't advanced\n");
7073 keep_going_pass_signal (ecs);
7078 /* Is thread TP in the middle of (software or hardware)
7079 single-stepping? (Note the result of this function must never be
7080 passed directly as target_resume's STEP parameter.) */
7083 currently_stepping (struct thread_info *tp)
7085 return ((tp->control.step_range_end
7086 && tp->control.step_resume_breakpoint == NULL)
7087 || tp->control.trap_expected
7088 || tp->stepped_breakpoint
7089 || bpstat_should_step ());
7092 /* Inferior has stepped into a subroutine call with source code that
7093 we should not step over. Do step to the first line of code in
7097 handle_step_into_function (struct gdbarch *gdbarch,
7098 struct execution_control_state *ecs)
7100 struct compunit_symtab *cust;
7101 struct symtab_and_line stop_func_sal, sr_sal;
7103 fill_in_stop_func (gdbarch, ecs);
7105 cust = find_pc_compunit_symtab (stop_pc);
7106 if (cust != NULL && compunit_language (cust) != language_asm)
7107 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7108 ecs->stop_func_start);
7110 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7111 /* Use the step_resume_break to step until the end of the prologue,
7112 even if that involves jumps (as it seems to on the vax under
7114 /* If the prologue ends in the middle of a source line, continue to
7115 the end of that source line (if it is still within the function).
7116 Otherwise, just go to end of prologue. */
7117 if (stop_func_sal.end
7118 && stop_func_sal.pc != ecs->stop_func_start
7119 && stop_func_sal.end < ecs->stop_func_end)
7120 ecs->stop_func_start = stop_func_sal.end;
7122 /* Architectures which require breakpoint adjustment might not be able
7123 to place a breakpoint at the computed address. If so, the test
7124 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7125 ecs->stop_func_start to an address at which a breakpoint may be
7126 legitimately placed.
7128 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7129 made, GDB will enter an infinite loop when stepping through
7130 optimized code consisting of VLIW instructions which contain
7131 subinstructions corresponding to different source lines. On
7132 FR-V, it's not permitted to place a breakpoint on any but the
7133 first subinstruction of a VLIW instruction. When a breakpoint is
7134 set, GDB will adjust the breakpoint address to the beginning of
7135 the VLIW instruction. Thus, we need to make the corresponding
7136 adjustment here when computing the stop address. */
7138 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7140 ecs->stop_func_start
7141 = gdbarch_adjust_breakpoint_address (gdbarch,
7142 ecs->stop_func_start);
7145 if (ecs->stop_func_start == stop_pc)
7147 /* We are already there: stop now. */
7148 end_stepping_range (ecs);
7153 /* Put the step-breakpoint there and go until there. */
7154 init_sal (&sr_sal); /* initialize to zeroes */
7155 sr_sal.pc = ecs->stop_func_start;
7156 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7157 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7159 /* Do not specify what the fp should be when we stop since on
7160 some machines the prologue is where the new fp value is
7162 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7164 /* And make sure stepping stops right away then. */
7165 ecs->event_thread->control.step_range_end
7166 = ecs->event_thread->control.step_range_start;
7171 /* Inferior has stepped backward into a subroutine call with source
7172 code that we should not step over. Do step to the beginning of the
7173 last line of code in it. */
7176 handle_step_into_function_backward (struct gdbarch *gdbarch,
7177 struct execution_control_state *ecs)
7179 struct compunit_symtab *cust;
7180 struct symtab_and_line stop_func_sal;
7182 fill_in_stop_func (gdbarch, ecs);
7184 cust = find_pc_compunit_symtab (stop_pc);
7185 if (cust != NULL && compunit_language (cust) != language_asm)
7186 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7187 ecs->stop_func_start);
7189 stop_func_sal = find_pc_line (stop_pc, 0);
7191 /* OK, we're just going to keep stepping here. */
7192 if (stop_func_sal.pc == stop_pc)
7194 /* We're there already. Just stop stepping now. */
7195 end_stepping_range (ecs);
7199 /* Else just reset the step range and keep going.
7200 No step-resume breakpoint, they don't work for
7201 epilogues, which can have multiple entry paths. */
7202 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7203 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7209 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7210 This is used to both functions and to skip over code. */
7213 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7214 struct symtab_and_line sr_sal,
7215 struct frame_id sr_id,
7216 enum bptype sr_type)
7218 /* There should never be more than one step-resume or longjmp-resume
7219 breakpoint per thread, so we should never be setting a new
7220 step_resume_breakpoint when one is already active. */
7221 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7222 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7225 fprintf_unfiltered (gdb_stdlog,
7226 "infrun: inserting step-resume breakpoint at %s\n",
7227 paddress (gdbarch, sr_sal.pc));
7229 inferior_thread ()->control.step_resume_breakpoint
7230 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7234 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7235 struct symtab_and_line sr_sal,
7236 struct frame_id sr_id)
7238 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7243 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7244 This is used to skip a potential signal handler.
7246 This is called with the interrupted function's frame. The signal
7247 handler, when it returns, will resume the interrupted function at
7251 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7253 struct symtab_and_line sr_sal;
7254 struct gdbarch *gdbarch;
7256 gdb_assert (return_frame != NULL);
7257 init_sal (&sr_sal); /* initialize to zeros */
7259 gdbarch = get_frame_arch (return_frame);
7260 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7261 sr_sal.section = find_pc_overlay (sr_sal.pc);
7262 sr_sal.pspace = get_frame_program_space (return_frame);
7264 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7265 get_stack_frame_id (return_frame),
7269 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7270 is used to skip a function after stepping into it (for "next" or if
7271 the called function has no debugging information).
7273 The current function has almost always been reached by single
7274 stepping a call or return instruction. NEXT_FRAME belongs to the
7275 current function, and the breakpoint will be set at the caller's
7278 This is a separate function rather than reusing
7279 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7280 get_prev_frame, which may stop prematurely (see the implementation
7281 of frame_unwind_caller_id for an example). */
7284 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7286 struct symtab_and_line sr_sal;
7287 struct gdbarch *gdbarch;
7289 /* We shouldn't have gotten here if we don't know where the call site
7291 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7293 init_sal (&sr_sal); /* initialize to zeros */
7295 gdbarch = frame_unwind_caller_arch (next_frame);
7296 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7297 frame_unwind_caller_pc (next_frame));
7298 sr_sal.section = find_pc_overlay (sr_sal.pc);
7299 sr_sal.pspace = frame_unwind_program_space (next_frame);
7301 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7302 frame_unwind_caller_id (next_frame));
7305 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7306 new breakpoint at the target of a jmp_buf. The handling of
7307 longjmp-resume uses the same mechanisms used for handling
7308 "step-resume" breakpoints. */
7311 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7313 /* There should never be more than one longjmp-resume breakpoint per
7314 thread, so we should never be setting a new
7315 longjmp_resume_breakpoint when one is already active. */
7316 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7319 fprintf_unfiltered (gdb_stdlog,
7320 "infrun: inserting longjmp-resume breakpoint at %s\n",
7321 paddress (gdbarch, pc));
7323 inferior_thread ()->control.exception_resume_breakpoint =
7324 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7327 /* Insert an exception resume breakpoint. TP is the thread throwing
7328 the exception. The block B is the block of the unwinder debug hook
7329 function. FRAME is the frame corresponding to the call to this
7330 function. SYM is the symbol of the function argument holding the
7331 target PC of the exception. */
7334 insert_exception_resume_breakpoint (struct thread_info *tp,
7335 const struct block *b,
7336 struct frame_info *frame,
7341 struct block_symbol vsym;
7342 struct value *value;
7344 struct breakpoint *bp;
7346 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7347 value = read_var_value (vsym.symbol, vsym.block, frame);
7348 /* If the value was optimized out, revert to the old behavior. */
7349 if (! value_optimized_out (value))
7351 handler = value_as_address (value);
7354 fprintf_unfiltered (gdb_stdlog,
7355 "infrun: exception resume at %lx\n",
7356 (unsigned long) handler);
7358 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7359 handler, bp_exception_resume);
7361 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7364 bp->thread = tp->num;
7365 inferior_thread ()->control.exception_resume_breakpoint = bp;
7368 CATCH (e, RETURN_MASK_ERROR)
7370 /* We want to ignore errors here. */
7375 /* A helper for check_exception_resume that sets an
7376 exception-breakpoint based on a SystemTap probe. */
7379 insert_exception_resume_from_probe (struct thread_info *tp,
7380 const struct bound_probe *probe,
7381 struct frame_info *frame)
7383 struct value *arg_value;
7385 struct breakpoint *bp;
7387 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7391 handler = value_as_address (arg_value);
7394 fprintf_unfiltered (gdb_stdlog,
7395 "infrun: exception resume at %s\n",
7396 paddress (get_objfile_arch (probe->objfile),
7399 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7400 handler, bp_exception_resume);
7401 bp->thread = tp->num;
7402 inferior_thread ()->control.exception_resume_breakpoint = bp;
7405 /* This is called when an exception has been intercepted. Check to
7406 see whether the exception's destination is of interest, and if so,
7407 set an exception resume breakpoint there. */
7410 check_exception_resume (struct execution_control_state *ecs,
7411 struct frame_info *frame)
7413 struct bound_probe probe;
7414 struct symbol *func;
7416 /* First see if this exception unwinding breakpoint was set via a
7417 SystemTap probe point. If so, the probe has two arguments: the
7418 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7419 set a breakpoint there. */
7420 probe = find_probe_by_pc (get_frame_pc (frame));
7423 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7427 func = get_frame_function (frame);
7433 const struct block *b;
7434 struct block_iterator iter;
7438 /* The exception breakpoint is a thread-specific breakpoint on
7439 the unwinder's debug hook, declared as:
7441 void _Unwind_DebugHook (void *cfa, void *handler);
7443 The CFA argument indicates the frame to which control is
7444 about to be transferred. HANDLER is the destination PC.
7446 We ignore the CFA and set a temporary breakpoint at HANDLER.
7447 This is not extremely efficient but it avoids issues in gdb
7448 with computing the DWARF CFA, and it also works even in weird
7449 cases such as throwing an exception from inside a signal
7452 b = SYMBOL_BLOCK_VALUE (func);
7453 ALL_BLOCK_SYMBOLS (b, iter, sym)
7455 if (!SYMBOL_IS_ARGUMENT (sym))
7462 insert_exception_resume_breakpoint (ecs->event_thread,
7468 CATCH (e, RETURN_MASK_ERROR)
7475 stop_waiting (struct execution_control_state *ecs)
7478 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7480 clear_step_over_info ();
7482 /* Let callers know we don't want to wait for the inferior anymore. */
7483 ecs->wait_some_more = 0;
7485 /* If all-stop, but the target is always in non-stop mode, stop all
7486 threads now that we're presenting the stop to the user. */
7487 if (!non_stop && target_is_non_stop_p ())
7488 stop_all_threads ();
7491 /* Like keep_going, but passes the signal to the inferior, even if the
7492 signal is set to nopass. */
7495 keep_going_pass_signal (struct execution_control_state *ecs)
7497 /* Make sure normal_stop is called if we get a QUIT handled before
7499 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7501 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7502 gdb_assert (!ecs->event_thread->resumed);
7504 /* Save the pc before execution, to compare with pc after stop. */
7505 ecs->event_thread->prev_pc
7506 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7508 if (ecs->event_thread->control.trap_expected)
7510 struct thread_info *tp = ecs->event_thread;
7513 fprintf_unfiltered (gdb_stdlog,
7514 "infrun: %s has trap_expected set, "
7515 "resuming to collect trap\n",
7516 target_pid_to_str (tp->ptid));
7518 /* We haven't yet gotten our trap, and either: intercepted a
7519 non-signal event (e.g., a fork); or took a signal which we
7520 are supposed to pass through to the inferior. Simply
7522 discard_cleanups (old_cleanups);
7523 resume (ecs->event_thread->suspend.stop_signal);
7525 else if (step_over_info_valid_p ())
7527 /* Another thread is stepping over a breakpoint in-line. If
7528 this thread needs a step-over too, queue the request. In
7529 either case, this resume must be deferred for later. */
7530 struct thread_info *tp = ecs->event_thread;
7532 if (ecs->hit_singlestep_breakpoint
7533 || thread_still_needs_step_over (tp))
7536 fprintf_unfiltered (gdb_stdlog,
7537 "infrun: step-over already in progress: "
7538 "step-over for %s deferred\n",
7539 target_pid_to_str (tp->ptid));
7540 thread_step_over_chain_enqueue (tp);
7545 fprintf_unfiltered (gdb_stdlog,
7546 "infrun: step-over in progress: "
7547 "resume of %s deferred\n",
7548 target_pid_to_str (tp->ptid));
7551 discard_cleanups (old_cleanups);
7555 struct regcache *regcache = get_current_regcache ();
7558 enum step_over_what step_what;
7560 /* Either the trap was not expected, but we are continuing
7561 anyway (if we got a signal, the user asked it be passed to
7564 We got our expected trap, but decided we should resume from
7567 We're going to run this baby now!
7569 Note that insert_breakpoints won't try to re-insert
7570 already inserted breakpoints. Therefore, we don't
7571 care if breakpoints were already inserted, or not. */
7573 /* If we need to step over a breakpoint, and we're not using
7574 displaced stepping to do so, insert all breakpoints
7575 (watchpoints, etc.) but the one we're stepping over, step one
7576 instruction, and then re-insert the breakpoint when that step
7579 step_what = thread_still_needs_step_over (ecs->event_thread);
7581 remove_bp = (ecs->hit_singlestep_breakpoint
7582 || (step_what & STEP_OVER_BREAKPOINT));
7583 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7585 /* We can't use displaced stepping if we need to step past a
7586 watchpoint. The instruction copied to the scratch pad would
7587 still trigger the watchpoint. */
7589 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7591 set_step_over_info (get_regcache_aspace (regcache),
7592 regcache_read_pc (regcache), remove_wps);
7594 else if (remove_wps)
7595 set_step_over_info (NULL, 0, remove_wps);
7597 /* If we now need to do an in-line step-over, we need to stop
7598 all other threads. Note this must be done before
7599 insert_breakpoints below, because that removes the breakpoint
7600 we're about to step over, otherwise other threads could miss
7602 if (step_over_info_valid_p () && target_is_non_stop_p ())
7603 stop_all_threads ();
7605 /* Stop stepping if inserting breakpoints fails. */
7608 insert_breakpoints ();
7610 CATCH (e, RETURN_MASK_ERROR)
7612 exception_print (gdb_stderr, e);
7614 discard_cleanups (old_cleanups);
7619 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7621 discard_cleanups (old_cleanups);
7622 resume (ecs->event_thread->suspend.stop_signal);
7625 prepare_to_wait (ecs);
7628 /* Called when we should continue running the inferior, because the
7629 current event doesn't cause a user visible stop. This does the
7630 resuming part; waiting for the next event is done elsewhere. */
7633 keep_going (struct execution_control_state *ecs)
7635 if (ecs->event_thread->control.trap_expected
7636 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7637 ecs->event_thread->control.trap_expected = 0;
7639 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7640 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7641 keep_going_pass_signal (ecs);
7644 /* This function normally comes after a resume, before
7645 handle_inferior_event exits. It takes care of any last bits of
7646 housekeeping, and sets the all-important wait_some_more flag. */
7649 prepare_to_wait (struct execution_control_state *ecs)
7652 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7654 ecs->wait_some_more = 1;
7656 if (!target_is_async_p ())
7657 mark_infrun_async_event_handler ();
7660 /* We are done with the step range of a step/next/si/ni command.
7661 Called once for each n of a "step n" operation. */
7664 end_stepping_range (struct execution_control_state *ecs)
7666 ecs->event_thread->control.stop_step = 1;
7670 /* Several print_*_reason functions to print why the inferior has stopped.
7671 We always print something when the inferior exits, or receives a signal.
7672 The rest of the cases are dealt with later on in normal_stop and
7673 print_it_typical. Ideally there should be a call to one of these
7674 print_*_reason functions functions from handle_inferior_event each time
7675 stop_waiting is called.
7677 Note that we don't call these directly, instead we delegate that to
7678 the interpreters, through observers. Interpreters then call these
7679 with whatever uiout is right. */
7682 print_end_stepping_range_reason (struct ui_out *uiout)
7684 /* For CLI-like interpreters, print nothing. */
7686 if (ui_out_is_mi_like_p (uiout))
7688 ui_out_field_string (uiout, "reason",
7689 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7694 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7696 annotate_signalled ();
7697 if (ui_out_is_mi_like_p (uiout))
7699 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7700 ui_out_text (uiout, "\nProgram terminated with signal ");
7701 annotate_signal_name ();
7702 ui_out_field_string (uiout, "signal-name",
7703 gdb_signal_to_name (siggnal));
7704 annotate_signal_name_end ();
7705 ui_out_text (uiout, ", ");
7706 annotate_signal_string ();
7707 ui_out_field_string (uiout, "signal-meaning",
7708 gdb_signal_to_string (siggnal));
7709 annotate_signal_string_end ();
7710 ui_out_text (uiout, ".\n");
7711 ui_out_text (uiout, "The program no longer exists.\n");
7715 print_exited_reason (struct ui_out *uiout, int exitstatus)
7717 struct inferior *inf = current_inferior ();
7718 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7720 annotate_exited (exitstatus);
7723 if (ui_out_is_mi_like_p (uiout))
7724 ui_out_field_string (uiout, "reason",
7725 async_reason_lookup (EXEC_ASYNC_EXITED));
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 with code ");
7731 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
7732 ui_out_text (uiout, "]\n");
7736 if (ui_out_is_mi_like_p (uiout))
7738 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7739 ui_out_text (uiout, "[Inferior ");
7740 ui_out_text (uiout, plongest (inf->num));
7741 ui_out_text (uiout, " (");
7742 ui_out_text (uiout, pidstr);
7743 ui_out_text (uiout, ") exited normally]\n");
7748 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7752 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
7754 struct thread_info *t = inferior_thread ();
7756 ui_out_text (uiout, "\n[");
7757 ui_out_field_string (uiout, "thread-name",
7758 target_pid_to_str (t->ptid));
7759 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
7760 ui_out_text (uiout, " stopped");
7764 ui_out_text (uiout, "\nProgram received signal ");
7765 annotate_signal_name ();
7766 if (ui_out_is_mi_like_p (uiout))
7768 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7769 ui_out_field_string (uiout, "signal-name",
7770 gdb_signal_to_name (siggnal));
7771 annotate_signal_name_end ();
7772 ui_out_text (uiout, ", ");
7773 annotate_signal_string ();
7774 ui_out_field_string (uiout, "signal-meaning",
7775 gdb_signal_to_string (siggnal));
7776 annotate_signal_string_end ();
7778 ui_out_text (uiout, ".\n");
7782 print_no_history_reason (struct ui_out *uiout)
7784 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
7787 /* Print current location without a level number, if we have changed
7788 functions or hit a breakpoint. Print source line if we have one.
7789 bpstat_print contains the logic deciding in detail what to print,
7790 based on the event(s) that just occurred. */
7793 print_stop_location (struct target_waitstatus *ws)
7796 enum print_what source_flag;
7797 int do_frame_printing = 1;
7798 struct thread_info *tp = inferior_thread ();
7800 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7804 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7805 should) carry around the function and does (or should) use
7806 that when doing a frame comparison. */
7807 if (tp->control.stop_step
7808 && frame_id_eq (tp->control.step_frame_id,
7809 get_frame_id (get_current_frame ()))
7810 && tp->control.step_start_function == find_pc_function (stop_pc))
7812 /* Finished step, just print source line. */
7813 source_flag = SRC_LINE;
7817 /* Print location and source line. */
7818 source_flag = SRC_AND_LOC;
7821 case PRINT_SRC_AND_LOC:
7822 /* Print location and source line. */
7823 source_flag = SRC_AND_LOC;
7825 case PRINT_SRC_ONLY:
7826 source_flag = SRC_LINE;
7829 /* Something bogus. */
7830 source_flag = SRC_LINE;
7831 do_frame_printing = 0;
7834 internal_error (__FILE__, __LINE__, _("Unknown value."));
7837 /* The behavior of this routine with respect to the source
7839 SRC_LINE: Print only source line
7840 LOCATION: Print only location
7841 SRC_AND_LOC: Print location and source line. */
7842 if (do_frame_printing)
7843 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7846 /* Cleanup that restores a previous current uiout. */
7849 restore_current_uiout_cleanup (void *arg)
7851 struct ui_out *saved_uiout = (struct ui_out *) arg;
7853 current_uiout = saved_uiout;
7859 print_stop_event (struct ui_out *uiout)
7861 struct cleanup *old_chain;
7862 struct target_waitstatus last;
7864 struct thread_info *tp;
7866 get_last_target_status (&last_ptid, &last);
7868 old_chain = make_cleanup (restore_current_uiout_cleanup, current_uiout);
7869 current_uiout = uiout;
7871 print_stop_location (&last);
7873 /* Display the auto-display expressions. */
7876 do_cleanups (old_chain);
7878 tp = inferior_thread ();
7879 if (tp->thread_fsm != NULL
7880 && thread_fsm_finished_p (tp->thread_fsm))
7882 struct return_value_info *rv;
7884 rv = thread_fsm_return_value (tp->thread_fsm);
7886 print_return_value (uiout, rv);
7893 maybe_remove_breakpoints (void)
7895 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7897 if (remove_breakpoints ())
7899 target_terminal_ours_for_output ();
7900 printf_filtered (_("Cannot remove breakpoints because "
7901 "program is no longer writable.\nFurther "
7902 "execution is probably impossible.\n"));
7907 /* The execution context that just caused a normal stop. */
7914 /* The event PTID. */
7918 /* If stopp for a thread event, this is the thread that caused the
7920 struct thread_info *thread;
7922 /* The inferior that caused the stop. */
7926 /* Returns a new stop context. If stopped for a thread event, this
7927 takes a strong reference to the thread. */
7929 static struct stop_context *
7930 save_stop_context (void)
7932 struct stop_context *sc = XNEW (struct stop_context);
7934 sc->stop_id = get_stop_id ();
7935 sc->ptid = inferior_ptid;
7936 sc->inf_num = current_inferior ()->num;
7938 if (!ptid_equal (inferior_ptid, null_ptid))
7940 /* Take a strong reference so that the thread can't be deleted
7942 sc->thread = inferior_thread ();
7943 sc->thread->refcount++;
7951 /* Release a stop context previously created with save_stop_context.
7952 Releases the strong reference to the thread as well. */
7955 release_stop_context_cleanup (void *arg)
7957 struct stop_context *sc = (struct stop_context *) arg;
7959 if (sc->thread != NULL)
7960 sc->thread->refcount--;
7964 /* Return true if the current context no longer matches the saved stop
7968 stop_context_changed (struct stop_context *prev)
7970 if (!ptid_equal (prev->ptid, inferior_ptid))
7972 if (prev->inf_num != current_inferior ()->num)
7974 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
7976 if (get_stop_id () != prev->stop_id)
7986 struct target_waitstatus last;
7988 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
7991 get_last_target_status (&last_ptid, &last);
7995 /* If an exception is thrown from this point on, make sure to
7996 propagate GDB's knowledge of the executing state to the
7997 frontend/user running state. A QUIT is an easy exception to see
7998 here, so do this before any filtered output. */
8000 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
8001 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8002 || last.kind == TARGET_WAITKIND_EXITED)
8004 /* On some targets, we may still have live threads in the
8005 inferior when we get a process exit event. E.g., for
8006 "checkpoint", when the current checkpoint/fork exits,
8007 linux-fork.c automatically switches to another fork from
8008 within target_mourn_inferior. */
8009 if (!ptid_equal (inferior_ptid, null_ptid))
8011 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
8012 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
8015 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8016 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
8018 /* As we're presenting a stop, and potentially removing breakpoints,
8019 update the thread list so we can tell whether there are threads
8020 running on the target. With target remote, for example, we can
8021 only learn about new threads when we explicitly update the thread
8022 list. Do this before notifying the interpreters about signal
8023 stops, end of stepping ranges, etc., so that the "new thread"
8024 output is emitted before e.g., "Program received signal FOO",
8025 instead of after. */
8026 update_thread_list ();
8028 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8029 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
8031 /* As with the notification of thread events, we want to delay
8032 notifying the user that we've switched thread context until
8033 the inferior actually stops.
8035 There's no point in saying anything if the inferior has exited.
8036 Note that SIGNALLED here means "exited with a signal", not
8037 "received a signal".
8039 Also skip saying anything in non-stop mode. In that mode, as we
8040 don't want GDB to switch threads behind the user's back, to avoid
8041 races where the user is typing a command to apply to thread x,
8042 but GDB switches to thread y before the user finishes entering
8043 the command, fetch_inferior_event installs a cleanup to restore
8044 the current thread back to the thread the user had selected right
8045 after this event is handled, so we're not really switching, only
8046 informing of a stop. */
8048 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8049 && target_has_execution
8050 && last.kind != TARGET_WAITKIND_SIGNALLED
8051 && last.kind != TARGET_WAITKIND_EXITED
8052 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8054 target_terminal_ours_for_output ();
8055 printf_filtered (_("[Switching to %s]\n"),
8056 target_pid_to_str (inferior_ptid));
8057 annotate_thread_changed ();
8058 previous_inferior_ptid = inferior_ptid;
8061 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8063 gdb_assert (sync_execution || !target_can_async_p ());
8065 target_terminal_ours_for_output ();
8066 printf_filtered (_("No unwaited-for children left.\n"));
8069 /* Note: this depends on the update_thread_list call above. */
8070 maybe_remove_breakpoints ();
8072 /* If an auto-display called a function and that got a signal,
8073 delete that auto-display to avoid an infinite recursion. */
8075 if (stopped_by_random_signal)
8076 disable_current_display ();
8078 target_terminal_ours ();
8079 async_enable_stdin ();
8081 /* Let the user/frontend see the threads as stopped. */
8082 do_cleanups (old_chain);
8084 /* Select innermost stack frame - i.e., current frame is frame 0,
8085 and current location is based on that. Handle the case where the
8086 dummy call is returning after being stopped. E.g. the dummy call
8087 previously hit a breakpoint. (If the dummy call returns
8088 normally, we won't reach here.) Do this before the stop hook is
8089 run, so that it doesn't get to see the temporary dummy frame,
8090 which is not where we'll present the stop. */
8091 if (has_stack_frames ())
8093 if (stop_stack_dummy == STOP_STACK_DUMMY)
8095 /* Pop the empty frame that contains the stack dummy. This
8096 also restores inferior state prior to the call (struct
8097 infcall_suspend_state). */
8098 struct frame_info *frame = get_current_frame ();
8100 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8102 /* frame_pop calls reinit_frame_cache as the last thing it
8103 does which means there's now no selected frame. */
8106 select_frame (get_current_frame ());
8108 /* Set the current source location. */
8109 set_current_sal_from_frame (get_current_frame ());
8112 /* Look up the hook_stop and run it (CLI internally handles problem
8113 of stop_command's pre-hook not existing). */
8114 if (stop_command != NULL)
8116 struct stop_context *saved_context = save_stop_context ();
8117 struct cleanup *old_chain
8118 = make_cleanup (release_stop_context_cleanup, saved_context);
8120 catch_errors (hook_stop_stub, stop_command,
8121 "Error while running hook_stop:\n", RETURN_MASK_ALL);
8123 /* If the stop hook resumes the target, then there's no point in
8124 trying to notify about the previous stop; its context is
8125 gone. Likewise if the command switches thread or inferior --
8126 the observers would print a stop for the wrong
8128 if (stop_context_changed (saved_context))
8130 do_cleanups (old_chain);
8133 do_cleanups (old_chain);
8136 /* Notify observers about the stop. This is where the interpreters
8137 print the stop event. */
8138 if (!ptid_equal (inferior_ptid, null_ptid))
8139 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8142 observer_notify_normal_stop (NULL, stop_print_frame);
8144 annotate_stopped ();
8146 if (target_has_execution)
8148 if (last.kind != TARGET_WAITKIND_SIGNALLED
8149 && last.kind != TARGET_WAITKIND_EXITED)
8150 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8151 Delete any breakpoint that is to be deleted at the next stop. */
8152 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8155 /* Try to get rid of automatically added inferiors that are no
8156 longer needed. Keeping those around slows down things linearly.
8157 Note that this never removes the current inferior. */
8164 hook_stop_stub (void *cmd)
8166 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
8171 signal_stop_state (int signo)
8173 return signal_stop[signo];
8177 signal_print_state (int signo)
8179 return signal_print[signo];
8183 signal_pass_state (int signo)
8185 return signal_program[signo];
8189 signal_cache_update (int signo)
8193 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8194 signal_cache_update (signo);
8199 signal_pass[signo] = (signal_stop[signo] == 0
8200 && signal_print[signo] == 0
8201 && signal_program[signo] == 1
8202 && signal_catch[signo] == 0);
8206 signal_stop_update (int signo, int state)
8208 int ret = signal_stop[signo];
8210 signal_stop[signo] = state;
8211 signal_cache_update (signo);
8216 signal_print_update (int signo, int state)
8218 int ret = signal_print[signo];
8220 signal_print[signo] = state;
8221 signal_cache_update (signo);
8226 signal_pass_update (int signo, int state)
8228 int ret = signal_program[signo];
8230 signal_program[signo] = state;
8231 signal_cache_update (signo);
8235 /* Update the global 'signal_catch' from INFO and notify the
8239 signal_catch_update (const unsigned int *info)
8243 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8244 signal_catch[i] = info[i] > 0;
8245 signal_cache_update (-1);
8246 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8250 sig_print_header (void)
8252 printf_filtered (_("Signal Stop\tPrint\tPass "
8253 "to program\tDescription\n"));
8257 sig_print_info (enum gdb_signal oursig)
8259 const char *name = gdb_signal_to_name (oursig);
8260 int name_padding = 13 - strlen (name);
8262 if (name_padding <= 0)
8265 printf_filtered ("%s", name);
8266 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8267 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8268 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8269 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8270 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8273 /* Specify how various signals in the inferior should be handled. */
8276 handle_command (char *args, int from_tty)
8279 int digits, wordlen;
8280 int sigfirst, signum, siglast;
8281 enum gdb_signal oursig;
8284 unsigned char *sigs;
8285 struct cleanup *old_chain;
8289 error_no_arg (_("signal to handle"));
8292 /* Allocate and zero an array of flags for which signals to handle. */
8294 nsigs = (int) GDB_SIGNAL_LAST;
8295 sigs = (unsigned char *) alloca (nsigs);
8296 memset (sigs, 0, nsigs);
8298 /* Break the command line up into args. */
8300 argv = gdb_buildargv (args);
8301 old_chain = make_cleanup_freeargv (argv);
8303 /* Walk through the args, looking for signal oursigs, signal names, and
8304 actions. Signal numbers and signal names may be interspersed with
8305 actions, with the actions being performed for all signals cumulatively
8306 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8308 while (*argv != NULL)
8310 wordlen = strlen (*argv);
8311 for (digits = 0; isdigit ((*argv)[digits]); digits++)
8315 sigfirst = siglast = -1;
8317 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
8319 /* Apply action to all signals except those used by the
8320 debugger. Silently skip those. */
8323 siglast = nsigs - 1;
8325 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
8327 SET_SIGS (nsigs, sigs, signal_stop);
8328 SET_SIGS (nsigs, sigs, signal_print);
8330 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
8332 UNSET_SIGS (nsigs, sigs, signal_program);
8334 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
8336 SET_SIGS (nsigs, sigs, signal_print);
8338 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
8340 SET_SIGS (nsigs, sigs, signal_program);
8342 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
8344 UNSET_SIGS (nsigs, sigs, signal_stop);
8346 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
8348 SET_SIGS (nsigs, sigs, signal_program);
8350 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
8352 UNSET_SIGS (nsigs, sigs, signal_print);
8353 UNSET_SIGS (nsigs, sigs, signal_stop);
8355 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
8357 UNSET_SIGS (nsigs, sigs, signal_program);
8359 else if (digits > 0)
8361 /* It is numeric. The numeric signal refers to our own
8362 internal signal numbering from target.h, not to host/target
8363 signal number. This is a feature; users really should be
8364 using symbolic names anyway, and the common ones like
8365 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8367 sigfirst = siglast = (int)
8368 gdb_signal_from_command (atoi (*argv));
8369 if ((*argv)[digits] == '-')
8372 gdb_signal_from_command (atoi ((*argv) + digits + 1));
8374 if (sigfirst > siglast)
8376 /* Bet he didn't figure we'd think of this case... */
8384 oursig = gdb_signal_from_name (*argv);
8385 if (oursig != GDB_SIGNAL_UNKNOWN)
8387 sigfirst = siglast = (int) oursig;
8391 /* Not a number and not a recognized flag word => complain. */
8392 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
8396 /* If any signal numbers or symbol names were found, set flags for
8397 which signals to apply actions to. */
8399 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8401 switch ((enum gdb_signal) signum)
8403 case GDB_SIGNAL_TRAP:
8404 case GDB_SIGNAL_INT:
8405 if (!allsigs && !sigs[signum])
8407 if (query (_("%s is used by the debugger.\n\
8408 Are you sure you want to change it? "),
8409 gdb_signal_to_name ((enum gdb_signal) signum)))
8415 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8416 gdb_flush (gdb_stdout);
8421 case GDB_SIGNAL_DEFAULT:
8422 case GDB_SIGNAL_UNKNOWN:
8423 /* Make sure that "all" doesn't print these. */
8434 for (signum = 0; signum < nsigs; signum++)
8437 signal_cache_update (-1);
8438 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8439 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8443 /* Show the results. */
8444 sig_print_header ();
8445 for (; signum < nsigs; signum++)
8447 sig_print_info ((enum gdb_signal) signum);
8453 do_cleanups (old_chain);
8456 /* Complete the "handle" command. */
8458 static VEC (char_ptr) *
8459 handle_completer (struct cmd_list_element *ignore,
8460 const char *text, const char *word)
8462 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
8463 static const char * const keywords[] =
8477 vec_signals = signal_completer (ignore, text, word);
8478 vec_keywords = complete_on_enum (keywords, word, word);
8480 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
8481 VEC_free (char_ptr, vec_signals);
8482 VEC_free (char_ptr, vec_keywords);
8487 gdb_signal_from_command (int num)
8489 if (num >= 1 && num <= 15)
8490 return (enum gdb_signal) num;
8491 error (_("Only signals 1-15 are valid as numeric signals.\n\
8492 Use \"info signals\" for a list of symbolic signals."));
8495 /* Print current contents of the tables set by the handle command.
8496 It is possible we should just be printing signals actually used
8497 by the current target (but for things to work right when switching
8498 targets, all signals should be in the signal tables). */
8501 signals_info (char *signum_exp, int from_tty)
8503 enum gdb_signal oursig;
8505 sig_print_header ();
8509 /* First see if this is a symbol name. */
8510 oursig = gdb_signal_from_name (signum_exp);
8511 if (oursig == GDB_SIGNAL_UNKNOWN)
8513 /* No, try numeric. */
8515 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8517 sig_print_info (oursig);
8521 printf_filtered ("\n");
8522 /* These ugly casts brought to you by the native VAX compiler. */
8523 for (oursig = GDB_SIGNAL_FIRST;
8524 (int) oursig < (int) GDB_SIGNAL_LAST;
8525 oursig = (enum gdb_signal) ((int) oursig + 1))
8529 if (oursig != GDB_SIGNAL_UNKNOWN
8530 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8531 sig_print_info (oursig);
8534 printf_filtered (_("\nUse the \"handle\" command "
8535 "to change these tables.\n"));
8538 /* Check if it makes sense to read $_siginfo from the current thread
8539 at this point. If not, throw an error. */
8542 validate_siginfo_access (void)
8544 /* No current inferior, no siginfo. */
8545 if (ptid_equal (inferior_ptid, null_ptid))
8546 error (_("No thread selected."));
8548 /* Don't try to read from a dead thread. */
8549 if (is_exited (inferior_ptid))
8550 error (_("The current thread has terminated"));
8552 /* ... or from a spinning thread. */
8553 if (is_running (inferior_ptid))
8554 error (_("Selected thread is running."));
8557 /* The $_siginfo convenience variable is a bit special. We don't know
8558 for sure the type of the value until we actually have a chance to
8559 fetch the data. The type can change depending on gdbarch, so it is
8560 also dependent on which thread you have selected.
8562 1. making $_siginfo be an internalvar that creates a new value on
8565 2. making the value of $_siginfo be an lval_computed value. */
8567 /* This function implements the lval_computed support for reading a
8571 siginfo_value_read (struct value *v)
8573 LONGEST transferred;
8575 validate_siginfo_access ();
8578 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8580 value_contents_all_raw (v),
8582 TYPE_LENGTH (value_type (v)));
8584 if (transferred != TYPE_LENGTH (value_type (v)))
8585 error (_("Unable to read siginfo"));
8588 /* This function implements the lval_computed support for writing a
8592 siginfo_value_write (struct value *v, struct value *fromval)
8594 LONGEST transferred;
8596 validate_siginfo_access ();
8598 transferred = target_write (¤t_target,
8599 TARGET_OBJECT_SIGNAL_INFO,
8601 value_contents_all_raw (fromval),
8603 TYPE_LENGTH (value_type (fromval)));
8605 if (transferred != TYPE_LENGTH (value_type (fromval)))
8606 error (_("Unable to write siginfo"));
8609 static const struct lval_funcs siginfo_value_funcs =
8615 /* Return a new value with the correct type for the siginfo object of
8616 the current thread using architecture GDBARCH. Return a void value
8617 if there's no object available. */
8619 static struct value *
8620 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8623 if (target_has_stack
8624 && !ptid_equal (inferior_ptid, null_ptid)
8625 && gdbarch_get_siginfo_type_p (gdbarch))
8627 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8629 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8632 return allocate_value (builtin_type (gdbarch)->builtin_void);
8636 /* infcall_suspend_state contains state about the program itself like its
8637 registers and any signal it received when it last stopped.
8638 This state must be restored regardless of how the inferior function call
8639 ends (either successfully, or after it hits a breakpoint or signal)
8640 if the program is to properly continue where it left off. */
8642 struct infcall_suspend_state
8644 struct thread_suspend_state thread_suspend;
8648 struct regcache *registers;
8650 /* Format of SIGINFO_DATA or NULL if it is not present. */
8651 struct gdbarch *siginfo_gdbarch;
8653 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8654 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8655 content would be invalid. */
8656 gdb_byte *siginfo_data;
8659 struct infcall_suspend_state *
8660 save_infcall_suspend_state (void)
8662 struct infcall_suspend_state *inf_state;
8663 struct thread_info *tp = inferior_thread ();
8664 struct regcache *regcache = get_current_regcache ();
8665 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8666 gdb_byte *siginfo_data = NULL;
8668 if (gdbarch_get_siginfo_type_p (gdbarch))
8670 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8671 size_t len = TYPE_LENGTH (type);
8672 struct cleanup *back_to;
8674 siginfo_data = (gdb_byte *) xmalloc (len);
8675 back_to = make_cleanup (xfree, siginfo_data);
8677 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8678 siginfo_data, 0, len) == len)
8679 discard_cleanups (back_to);
8682 /* Errors ignored. */
8683 do_cleanups (back_to);
8684 siginfo_data = NULL;
8688 inf_state = XCNEW (struct infcall_suspend_state);
8692 inf_state->siginfo_gdbarch = gdbarch;
8693 inf_state->siginfo_data = siginfo_data;
8696 inf_state->thread_suspend = tp->suspend;
8698 /* run_inferior_call will not use the signal due to its `proceed' call with
8699 GDB_SIGNAL_0 anyway. */
8700 tp->suspend.stop_signal = GDB_SIGNAL_0;
8702 inf_state->stop_pc = stop_pc;
8704 inf_state->registers = regcache_dup (regcache);
8709 /* Restore inferior session state to INF_STATE. */
8712 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8714 struct thread_info *tp = inferior_thread ();
8715 struct regcache *regcache = get_current_regcache ();
8716 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8718 tp->suspend = inf_state->thread_suspend;
8720 stop_pc = inf_state->stop_pc;
8722 if (inf_state->siginfo_gdbarch == gdbarch)
8724 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8726 /* Errors ignored. */
8727 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8728 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8731 /* The inferior can be gone if the user types "print exit(0)"
8732 (and perhaps other times). */
8733 if (target_has_execution)
8734 /* NB: The register write goes through to the target. */
8735 regcache_cpy (regcache, inf_state->registers);
8737 discard_infcall_suspend_state (inf_state);
8741 do_restore_infcall_suspend_state_cleanup (void *state)
8743 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8747 make_cleanup_restore_infcall_suspend_state
8748 (struct infcall_suspend_state *inf_state)
8750 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8754 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8756 regcache_xfree (inf_state->registers);
8757 xfree (inf_state->siginfo_data);
8762 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8764 return inf_state->registers;
8767 /* infcall_control_state contains state regarding gdb's control of the
8768 inferior itself like stepping control. It also contains session state like
8769 the user's currently selected frame. */
8771 struct infcall_control_state
8773 struct thread_control_state thread_control;
8774 struct inferior_control_state inferior_control;
8777 enum stop_stack_kind stop_stack_dummy;
8778 int stopped_by_random_signal;
8779 int stop_after_trap;
8781 /* ID if the selected frame when the inferior function call was made. */
8782 struct frame_id selected_frame_id;
8785 /* Save all of the information associated with the inferior<==>gdb
8788 struct infcall_control_state *
8789 save_infcall_control_state (void)
8791 struct infcall_control_state *inf_status =
8792 XNEW (struct infcall_control_state);
8793 struct thread_info *tp = inferior_thread ();
8794 struct inferior *inf = current_inferior ();
8796 inf_status->thread_control = tp->control;
8797 inf_status->inferior_control = inf->control;
8799 tp->control.step_resume_breakpoint = NULL;
8800 tp->control.exception_resume_breakpoint = NULL;
8802 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8803 chain. If caller's caller is walking the chain, they'll be happier if we
8804 hand them back the original chain when restore_infcall_control_state is
8806 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8809 inf_status->stop_stack_dummy = stop_stack_dummy;
8810 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8811 inf_status->stop_after_trap = stop_after_trap;
8813 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8819 restore_selected_frame (void *args)
8821 struct frame_id *fid = (struct frame_id *) args;
8822 struct frame_info *frame;
8824 frame = frame_find_by_id (*fid);
8826 /* If inf_status->selected_frame_id is NULL, there was no previously
8830 warning (_("Unable to restore previously selected frame."));
8834 select_frame (frame);
8839 /* Restore inferior session state to INF_STATUS. */
8842 restore_infcall_control_state (struct infcall_control_state *inf_status)
8844 struct thread_info *tp = inferior_thread ();
8845 struct inferior *inf = current_inferior ();
8847 if (tp->control.step_resume_breakpoint)
8848 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8850 if (tp->control.exception_resume_breakpoint)
8851 tp->control.exception_resume_breakpoint->disposition
8852 = disp_del_at_next_stop;
8854 /* Handle the bpstat_copy of the chain. */
8855 bpstat_clear (&tp->control.stop_bpstat);
8857 tp->control = inf_status->thread_control;
8858 inf->control = inf_status->inferior_control;
8861 stop_stack_dummy = inf_status->stop_stack_dummy;
8862 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8863 stop_after_trap = inf_status->stop_after_trap;
8865 if (target_has_stack)
8867 /* The point of catch_errors is that if the stack is clobbered,
8868 walking the stack might encounter a garbage pointer and
8869 error() trying to dereference it. */
8871 (restore_selected_frame, &inf_status->selected_frame_id,
8872 "Unable to restore previously selected frame:\n",
8873 RETURN_MASK_ERROR) == 0)
8874 /* Error in restoring the selected frame. Select the innermost
8876 select_frame (get_current_frame ());
8883 do_restore_infcall_control_state_cleanup (void *sts)
8885 restore_infcall_control_state ((struct infcall_control_state *) sts);
8889 make_cleanup_restore_infcall_control_state
8890 (struct infcall_control_state *inf_status)
8892 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
8896 discard_infcall_control_state (struct infcall_control_state *inf_status)
8898 if (inf_status->thread_control.step_resume_breakpoint)
8899 inf_status->thread_control.step_resume_breakpoint->disposition
8900 = disp_del_at_next_stop;
8902 if (inf_status->thread_control.exception_resume_breakpoint)
8903 inf_status->thread_control.exception_resume_breakpoint->disposition
8904 = disp_del_at_next_stop;
8906 /* See save_infcall_control_state for info on stop_bpstat. */
8907 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8912 /* restore_inferior_ptid() will be used by the cleanup machinery
8913 to restore the inferior_ptid value saved in a call to
8914 save_inferior_ptid(). */
8917 restore_inferior_ptid (void *arg)
8919 ptid_t *saved_ptid_ptr = (ptid_t *) arg;
8921 inferior_ptid = *saved_ptid_ptr;
8925 /* Save the value of inferior_ptid so that it may be restored by a
8926 later call to do_cleanups(). Returns the struct cleanup pointer
8927 needed for later doing the cleanup. */
8930 save_inferior_ptid (void)
8932 ptid_t *saved_ptid_ptr = XNEW (ptid_t);
8934 *saved_ptid_ptr = inferior_ptid;
8935 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
8941 clear_exit_convenience_vars (void)
8943 clear_internalvar (lookup_internalvar ("_exitsignal"));
8944 clear_internalvar (lookup_internalvar ("_exitcode"));
8948 /* User interface for reverse debugging:
8949 Set exec-direction / show exec-direction commands
8950 (returns error unless target implements to_set_exec_direction method). */
8952 enum exec_direction_kind execution_direction = EXEC_FORWARD;
8953 static const char exec_forward[] = "forward";
8954 static const char exec_reverse[] = "reverse";
8955 static const char *exec_direction = exec_forward;
8956 static const char *const exec_direction_names[] = {
8963 set_exec_direction_func (char *args, int from_tty,
8964 struct cmd_list_element *cmd)
8966 if (target_can_execute_reverse)
8968 if (!strcmp (exec_direction, exec_forward))
8969 execution_direction = EXEC_FORWARD;
8970 else if (!strcmp (exec_direction, exec_reverse))
8971 execution_direction = EXEC_REVERSE;
8975 exec_direction = exec_forward;
8976 error (_("Target does not support this operation."));
8981 show_exec_direction_func (struct ui_file *out, int from_tty,
8982 struct cmd_list_element *cmd, const char *value)
8984 switch (execution_direction) {
8986 fprintf_filtered (out, _("Forward.\n"));
8989 fprintf_filtered (out, _("Reverse.\n"));
8992 internal_error (__FILE__, __LINE__,
8993 _("bogus execution_direction value: %d"),
8994 (int) execution_direction);
8999 show_schedule_multiple (struct ui_file *file, int from_tty,
9000 struct cmd_list_element *c, const char *value)
9002 fprintf_filtered (file, _("Resuming the execution of threads "
9003 "of all processes is %s.\n"), value);
9006 /* Implementation of `siginfo' variable. */
9008 static const struct internalvar_funcs siginfo_funcs =
9015 /* Callback for infrun's target events source. This is marked when a
9016 thread has a pending status to process. */
9019 infrun_async_inferior_event_handler (gdb_client_data data)
9021 inferior_event_handler (INF_REG_EVENT, NULL);
9025 _initialize_infrun (void)
9029 struct cmd_list_element *c;
9031 /* Register extra event sources in the event loop. */
9032 infrun_async_inferior_event_token
9033 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9035 add_info ("signals", signals_info, _("\
9036 What debugger does when program gets various signals.\n\
9037 Specify a signal as argument to print info on that signal only."));
9038 add_info_alias ("handle", "signals", 0);
9040 c = add_com ("handle", class_run, handle_command, _("\
9041 Specify how to handle signals.\n\
9042 Usage: handle SIGNAL [ACTIONS]\n\
9043 Args are signals and actions to apply to those signals.\n\
9044 If no actions are specified, the current settings for the specified signals\n\
9045 will be displayed instead.\n\
9047 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9048 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9049 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9050 The special arg \"all\" is recognized to mean all signals except those\n\
9051 used by the debugger, typically SIGTRAP and SIGINT.\n\
9053 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9054 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9055 Stop means reenter debugger if this signal happens (implies print).\n\
9056 Print means print a message if this signal happens.\n\
9057 Pass means let program see this signal; otherwise program doesn't know.\n\
9058 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9059 Pass and Stop may be combined.\n\
9061 Multiple signals may be specified. Signal numbers and signal names\n\
9062 may be interspersed with actions, with the actions being performed for\n\
9063 all signals cumulatively specified."));
9064 set_cmd_completer (c, handle_completer);
9067 stop_command = add_cmd ("stop", class_obscure,
9068 not_just_help_class_command, _("\
9069 There is no `stop' command, but you can set a hook on `stop'.\n\
9070 This allows you to set a list of commands to be run each time execution\n\
9071 of the program stops."), &cmdlist);
9073 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9074 Set inferior debugging."), _("\
9075 Show inferior debugging."), _("\
9076 When non-zero, inferior specific debugging is enabled."),
9079 &setdebuglist, &showdebuglist);
9081 add_setshow_boolean_cmd ("displaced", class_maintenance,
9082 &debug_displaced, _("\
9083 Set displaced stepping debugging."), _("\
9084 Show displaced stepping debugging."), _("\
9085 When non-zero, displaced stepping specific debugging is enabled."),
9087 show_debug_displaced,
9088 &setdebuglist, &showdebuglist);
9090 add_setshow_boolean_cmd ("non-stop", no_class,
9092 Set whether gdb controls the inferior in non-stop mode."), _("\
9093 Show whether gdb controls the inferior in non-stop mode."), _("\
9094 When debugging a multi-threaded program and this setting is\n\
9095 off (the default, also called all-stop mode), when one thread stops\n\
9096 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9097 all other threads in the program while you interact with the thread of\n\
9098 interest. When you continue or step a thread, you can allow the other\n\
9099 threads to run, or have them remain stopped, but while you inspect any\n\
9100 thread's state, all threads stop.\n\
9102 In non-stop mode, when one thread stops, other threads can continue\n\
9103 to run freely. You'll be able to step each thread independently,\n\
9104 leave it stopped or free to run as needed."),
9110 numsigs = (int) GDB_SIGNAL_LAST;
9111 signal_stop = XNEWVEC (unsigned char, numsigs);
9112 signal_print = XNEWVEC (unsigned char, numsigs);
9113 signal_program = XNEWVEC (unsigned char, numsigs);
9114 signal_catch = XNEWVEC (unsigned char, numsigs);
9115 signal_pass = XNEWVEC (unsigned char, numsigs);
9116 for (i = 0; i < numsigs; i++)
9119 signal_print[i] = 1;
9120 signal_program[i] = 1;
9121 signal_catch[i] = 0;
9124 /* Signals caused by debugger's own actions should not be given to
9125 the program afterwards.
9127 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9128 explicitly specifies that it should be delivered to the target
9129 program. Typically, that would occur when a user is debugging a
9130 target monitor on a simulator: the target monitor sets a
9131 breakpoint; the simulator encounters this breakpoint and halts
9132 the simulation handing control to GDB; GDB, noting that the stop
9133 address doesn't map to any known breakpoint, returns control back
9134 to the simulator; the simulator then delivers the hardware
9135 equivalent of a GDB_SIGNAL_TRAP to the program being
9137 signal_program[GDB_SIGNAL_TRAP] = 0;
9138 signal_program[GDB_SIGNAL_INT] = 0;
9140 /* Signals that are not errors should not normally enter the debugger. */
9141 signal_stop[GDB_SIGNAL_ALRM] = 0;
9142 signal_print[GDB_SIGNAL_ALRM] = 0;
9143 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9144 signal_print[GDB_SIGNAL_VTALRM] = 0;
9145 signal_stop[GDB_SIGNAL_PROF] = 0;
9146 signal_print[GDB_SIGNAL_PROF] = 0;
9147 signal_stop[GDB_SIGNAL_CHLD] = 0;
9148 signal_print[GDB_SIGNAL_CHLD] = 0;
9149 signal_stop[GDB_SIGNAL_IO] = 0;
9150 signal_print[GDB_SIGNAL_IO] = 0;
9151 signal_stop[GDB_SIGNAL_POLL] = 0;
9152 signal_print[GDB_SIGNAL_POLL] = 0;
9153 signal_stop[GDB_SIGNAL_URG] = 0;
9154 signal_print[GDB_SIGNAL_URG] = 0;
9155 signal_stop[GDB_SIGNAL_WINCH] = 0;
9156 signal_print[GDB_SIGNAL_WINCH] = 0;
9157 signal_stop[GDB_SIGNAL_PRIO] = 0;
9158 signal_print[GDB_SIGNAL_PRIO] = 0;
9160 /* These signals are used internally by user-level thread
9161 implementations. (See signal(5) on Solaris.) Like the above
9162 signals, a healthy program receives and handles them as part of
9163 its normal operation. */
9164 signal_stop[GDB_SIGNAL_LWP] = 0;
9165 signal_print[GDB_SIGNAL_LWP] = 0;
9166 signal_stop[GDB_SIGNAL_WAITING] = 0;
9167 signal_print[GDB_SIGNAL_WAITING] = 0;
9168 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9169 signal_print[GDB_SIGNAL_CANCEL] = 0;
9171 /* Update cached state. */
9172 signal_cache_update (-1);
9174 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9175 &stop_on_solib_events, _("\
9176 Set stopping for shared library events."), _("\
9177 Show stopping for shared library events."), _("\
9178 If nonzero, gdb will give control to the user when the dynamic linker\n\
9179 notifies gdb of shared library events. The most common event of interest\n\
9180 to the user would be loading/unloading of a new library."),
9181 set_stop_on_solib_events,
9182 show_stop_on_solib_events,
9183 &setlist, &showlist);
9185 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9186 follow_fork_mode_kind_names,
9187 &follow_fork_mode_string, _("\
9188 Set debugger response to a program call of fork or vfork."), _("\
9189 Show debugger response to a program call of fork or vfork."), _("\
9190 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9191 parent - the original process is debugged after a fork\n\
9192 child - the new process is debugged after a fork\n\
9193 The unfollowed process will continue to run.\n\
9194 By default, the debugger will follow the parent process."),
9196 show_follow_fork_mode_string,
9197 &setlist, &showlist);
9199 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9200 follow_exec_mode_names,
9201 &follow_exec_mode_string, _("\
9202 Set debugger response to a program call of exec."), _("\
9203 Show debugger response to a program call of exec."), _("\
9204 An exec call replaces the program image of a process.\n\
9206 follow-exec-mode can be:\n\
9208 new - the debugger creates a new inferior and rebinds the process\n\
9209 to this new inferior. The program the process was running before\n\
9210 the exec call can be restarted afterwards by restarting the original\n\
9213 same - the debugger keeps the process bound to the same inferior.\n\
9214 The new executable image replaces the previous executable loaded in\n\
9215 the inferior. Restarting the inferior after the exec call restarts\n\
9216 the executable the process was running after the exec call.\n\
9218 By default, the debugger will use the same inferior."),
9220 show_follow_exec_mode_string,
9221 &setlist, &showlist);
9223 add_setshow_enum_cmd ("scheduler-locking", class_run,
9224 scheduler_enums, &scheduler_mode, _("\
9225 Set mode for locking scheduler during execution."), _("\
9226 Show mode for locking scheduler during execution."), _("\
9227 off == no locking (threads may preempt at any time)\n\
9228 on == full locking (no thread except the current thread may run)\n\
9229 This applies to both normal execution and replay mode.\n\
9230 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9231 In this mode, other threads may run during other commands.\n\
9232 This applies to both normal execution and replay mode.\n\
9233 replay == scheduler locked in replay mode and unlocked during normal execution."),
9234 set_schedlock_func, /* traps on target vector */
9235 show_scheduler_mode,
9236 &setlist, &showlist);
9238 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9239 Set mode for resuming threads of all processes."), _("\
9240 Show mode for resuming threads of all processes."), _("\
9241 When on, execution commands (such as 'continue' or 'next') resume all\n\
9242 threads of all processes. When off (which is the default), execution\n\
9243 commands only resume the threads of the current process. The set of\n\
9244 threads that are resumed is further refined by the scheduler-locking\n\
9245 mode (see help set scheduler-locking)."),
9247 show_schedule_multiple,
9248 &setlist, &showlist);
9250 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9251 Set mode of the step operation."), _("\
9252 Show mode of the step operation."), _("\
9253 When set, doing a step over a function without debug line information\n\
9254 will stop at the first instruction of that function. Otherwise, the\n\
9255 function is skipped and the step command stops at a different source line."),
9257 show_step_stop_if_no_debug,
9258 &setlist, &showlist);
9260 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9261 &can_use_displaced_stepping, _("\
9262 Set debugger's willingness to use displaced stepping."), _("\
9263 Show debugger's willingness to use displaced stepping."), _("\
9264 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9265 supported by the target architecture. If off, gdb will not use displaced\n\
9266 stepping to step over breakpoints, even if such is supported by the target\n\
9267 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9268 if the target architecture supports it and non-stop mode is active, but will not\n\
9269 use it in all-stop mode (see help set non-stop)."),
9271 show_can_use_displaced_stepping,
9272 &setlist, &showlist);
9274 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9275 &exec_direction, _("Set direction of execution.\n\
9276 Options are 'forward' or 'reverse'."),
9277 _("Show direction of execution (forward/reverse)."),
9278 _("Tells gdb whether to execute forward or backward."),
9279 set_exec_direction_func, show_exec_direction_func,
9280 &setlist, &showlist);
9282 /* Set/show detach-on-fork: user-settable mode. */
9284 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9285 Set whether gdb will detach the child of a fork."), _("\
9286 Show whether gdb will detach the child of a fork."), _("\
9287 Tells gdb whether to detach the child of a fork."),
9288 NULL, NULL, &setlist, &showlist);
9290 /* Set/show disable address space randomization mode. */
9292 add_setshow_boolean_cmd ("disable-randomization", class_support,
9293 &disable_randomization, _("\
9294 Set disabling of debuggee's virtual address space randomization."), _("\
9295 Show disabling of debuggee's virtual address space randomization."), _("\
9296 When this mode is on (which is the default), randomization of the virtual\n\
9297 address space is disabled. Standalone programs run with the randomization\n\
9298 enabled by default on some platforms."),
9299 &set_disable_randomization,
9300 &show_disable_randomization,
9301 &setlist, &showlist);
9303 /* ptid initializations */
9304 inferior_ptid = null_ptid;
9305 target_last_wait_ptid = minus_one_ptid;
9307 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9308 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9309 observer_attach_thread_exit (infrun_thread_thread_exit);
9310 observer_attach_inferior_exit (infrun_inferior_exit);
9312 /* Explicitly create without lookup, since that tries to create a
9313 value with a void typed value, and when we get here, gdbarch
9314 isn't initialized yet. At this point, we're quite sure there
9315 isn't another convenience variable of the same name. */
9316 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9318 add_setshow_boolean_cmd ("observer", no_class,
9319 &observer_mode_1, _("\
9320 Set whether gdb controls the inferior in observer mode."), _("\
9321 Show whether gdb controls the inferior in observer mode."), _("\
9322 In observer mode, GDB can get data from the inferior, but not\n\
9323 affect its execution. Registers and memory may not be changed,\n\
9324 breakpoints may not be set, and the program cannot be interrupted\n\