1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2017 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"
66 #include "common/enum-flags.h"
67 #include "progspace-and-thread.h"
68 #include "common/gdb_optional.h"
69 #include "arch-utils.h"
71 /* Prototypes for local functions */
73 static void info_signals_command (char *, int);
75 static void handle_command (char *, int);
77 static void sig_print_info (enum gdb_signal);
79 static void sig_print_header (void);
81 static void resume_cleanups (void *);
83 static int hook_stop_stub (void *);
85 static int restore_selected_frame (void *);
87 static int follow_fork (void);
89 static int follow_fork_inferior (int follow_child, int detach_fork);
91 static void follow_inferior_reset_breakpoints (void);
93 static void set_schedlock_func (char *args, int from_tty,
94 struct cmd_list_element *c);
96 static int currently_stepping (struct thread_info *tp);
98 void _initialize_infrun (void);
100 void nullify_last_target_wait_ptid (void);
102 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
104 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
106 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
108 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
110 /* Asynchronous signal handler registered as event loop source for
111 when we have pending events ready to be passed to the core. */
112 static struct async_event_handler *infrun_async_inferior_event_token;
114 /* Stores whether infrun_async was previously enabled or disabled.
115 Starts off as -1, indicating "never enabled/disabled". */
116 static int infrun_is_async = -1;
121 infrun_async (int enable)
123 if (infrun_is_async != enable)
125 infrun_is_async = enable;
128 fprintf_unfiltered (gdb_stdlog,
129 "infrun: infrun_async(%d)\n",
133 mark_async_event_handler (infrun_async_inferior_event_token);
135 clear_async_event_handler (infrun_async_inferior_event_token);
142 mark_infrun_async_event_handler (void)
144 mark_async_event_handler (infrun_async_inferior_event_token);
147 /* When set, stop the 'step' command if we enter a function which has
148 no line number information. The normal behavior is that we step
149 over such function. */
150 int step_stop_if_no_debug = 0;
152 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
153 struct cmd_list_element *c, const char *value)
155 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
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 after stop if current stack frame should be printed. */
392 static int stop_print_frame;
394 /* This is a cached copy of the pid/waitstatus of the last event
395 returned by target_wait()/deprecated_target_wait_hook(). This
396 information is returned by get_last_target_status(). */
397 static ptid_t target_last_wait_ptid;
398 static struct target_waitstatus target_last_waitstatus;
400 static void context_switch (ptid_t ptid);
402 void init_thread_stepping_state (struct thread_info *tss);
404 static const char follow_fork_mode_child[] = "child";
405 static const char follow_fork_mode_parent[] = "parent";
407 static const char *const follow_fork_mode_kind_names[] = {
408 follow_fork_mode_child,
409 follow_fork_mode_parent,
413 static const char *follow_fork_mode_string = follow_fork_mode_parent;
415 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
416 struct cmd_list_element *c, const char *value)
418 fprintf_filtered (file,
419 _("Debugger response to a program "
420 "call of fork or vfork is \"%s\".\n"),
425 /* Handle changes to the inferior list based on the type of fork,
426 which process is being followed, and whether the other process
427 should be detached. On entry inferior_ptid must be the ptid of
428 the fork parent. At return inferior_ptid is the ptid of the
429 followed inferior. */
432 follow_fork_inferior (int follow_child, int detach_fork)
435 ptid_t parent_ptid, child_ptid;
437 has_vforked = (inferior_thread ()->pending_follow.kind
438 == TARGET_WAITKIND_VFORKED);
439 parent_ptid = inferior_ptid;
440 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
443 && !non_stop /* Non-stop always resumes both branches. */
444 && current_ui->prompt_state == PROMPT_BLOCKED
445 && !(follow_child || detach_fork || sched_multi))
447 /* The parent stays blocked inside the vfork syscall until the
448 child execs or exits. If we don't let the child run, then
449 the parent stays blocked. If we're telling the parent to run
450 in the foreground, the user will not be able to ctrl-c to get
451 back the terminal, effectively hanging the debug session. */
452 fprintf_filtered (gdb_stderr, _("\
453 Can not resume the parent process over vfork in the foreground while\n\
454 holding the child stopped. Try \"set detach-on-fork\" or \
455 \"set schedule-multiple\".\n"));
456 /* FIXME output string > 80 columns. */
462 /* Detach new forked process? */
465 /* Before detaching from the child, remove all breakpoints
466 from it. If we forked, then this has already been taken
467 care of by infrun.c. If we vforked however, any
468 breakpoint inserted in the parent is visible in the
469 child, even those added while stopped in a vfork
470 catchpoint. This will remove the breakpoints from the
471 parent also, but they'll be reinserted below. */
474 /* Keep breakpoints list in sync. */
475 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
478 if (info_verbose || debug_infrun)
480 /* Ensure that we have a process ptid. */
481 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
483 target_terminal_ours_for_output ();
484 fprintf_filtered (gdb_stdlog,
485 _("Detaching after %s from child %s.\n"),
486 has_vforked ? "vfork" : "fork",
487 target_pid_to_str (process_ptid));
492 struct inferior *parent_inf, *child_inf;
494 /* Add process to GDB's tables. */
495 child_inf = add_inferior (ptid_get_pid (child_ptid));
497 parent_inf = current_inferior ();
498 child_inf->attach_flag = parent_inf->attach_flag;
499 copy_terminal_info (child_inf, parent_inf);
500 child_inf->gdbarch = parent_inf->gdbarch;
501 copy_inferior_target_desc_info (child_inf, parent_inf);
503 scoped_restore_current_pspace_and_thread restore_pspace_thread;
505 inferior_ptid = child_ptid;
506 add_thread (inferior_ptid);
507 set_current_inferior (child_inf);
508 child_inf->symfile_flags = SYMFILE_NO_READ;
510 /* If this is a vfork child, then the address-space is
511 shared with the parent. */
514 child_inf->pspace = parent_inf->pspace;
515 child_inf->aspace = parent_inf->aspace;
517 /* The parent will be frozen until the child is done
518 with the shared region. Keep track of the
520 child_inf->vfork_parent = parent_inf;
521 child_inf->pending_detach = 0;
522 parent_inf->vfork_child = child_inf;
523 parent_inf->pending_detach = 0;
527 child_inf->aspace = new_address_space ();
528 child_inf->pspace = add_program_space (child_inf->aspace);
529 child_inf->removable = 1;
530 set_current_program_space (child_inf->pspace);
531 clone_program_space (child_inf->pspace, parent_inf->pspace);
533 /* Let the shared library layer (e.g., solib-svr4) learn
534 about this new process, relocate the cloned exec, pull
535 in shared libraries, and install the solib event
536 breakpoint. If a "cloned-VM" event was propagated
537 better throughout the core, this wouldn't be
539 solib_create_inferior_hook (0);
545 struct inferior *parent_inf;
547 parent_inf = current_inferior ();
549 /* If we detached from the child, then we have to be careful
550 to not insert breakpoints in the parent until the child
551 is done with the shared memory region. However, if we're
552 staying attached to the child, then we can and should
553 insert breakpoints, so that we can debug it. A
554 subsequent child exec or exit is enough to know when does
555 the child stops using the parent's address space. */
556 parent_inf->waiting_for_vfork_done = detach_fork;
557 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
562 /* Follow the child. */
563 struct inferior *parent_inf, *child_inf;
564 struct program_space *parent_pspace;
566 if (info_verbose || debug_infrun)
568 target_terminal_ours_for_output ();
569 fprintf_filtered (gdb_stdlog,
570 _("Attaching after %s %s to child %s.\n"),
571 target_pid_to_str (parent_ptid),
572 has_vforked ? "vfork" : "fork",
573 target_pid_to_str (child_ptid));
576 /* Add the new inferior first, so that the target_detach below
577 doesn't unpush the target. */
579 child_inf = add_inferior (ptid_get_pid (child_ptid));
581 parent_inf = current_inferior ();
582 child_inf->attach_flag = parent_inf->attach_flag;
583 copy_terminal_info (child_inf, parent_inf);
584 child_inf->gdbarch = parent_inf->gdbarch;
585 copy_inferior_target_desc_info (child_inf, parent_inf);
587 parent_pspace = parent_inf->pspace;
589 /* If we're vforking, we want to hold on to the parent until the
590 child exits or execs. At child exec or exit time we can
591 remove the old breakpoints from the parent and detach or
592 resume debugging it. Otherwise, detach the parent now; we'll
593 want to reuse it's program/address spaces, but we can't set
594 them to the child before removing breakpoints from the
595 parent, otherwise, the breakpoints module could decide to
596 remove breakpoints from the wrong process (since they'd be
597 assigned to the same address space). */
601 gdb_assert (child_inf->vfork_parent == NULL);
602 gdb_assert (parent_inf->vfork_child == NULL);
603 child_inf->vfork_parent = parent_inf;
604 child_inf->pending_detach = 0;
605 parent_inf->vfork_child = child_inf;
606 parent_inf->pending_detach = detach_fork;
607 parent_inf->waiting_for_vfork_done = 0;
609 else if (detach_fork)
611 if (info_verbose || debug_infrun)
613 /* Ensure that we have a process ptid. */
614 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
616 target_terminal_ours_for_output ();
617 fprintf_filtered (gdb_stdlog,
618 _("Detaching after fork from "
620 target_pid_to_str (process_ptid));
623 target_detach (NULL, 0);
626 /* Note that the detach above makes PARENT_INF dangling. */
628 /* Add the child thread to the appropriate lists, and switch to
629 this new thread, before cloning the program space, and
630 informing the solib layer about this new process. */
632 inferior_ptid = child_ptid;
633 add_thread (inferior_ptid);
634 set_current_inferior (child_inf);
636 /* If this is a vfork child, then the address-space is shared
637 with the parent. If we detached from the parent, then we can
638 reuse the parent's program/address spaces. */
639 if (has_vforked || detach_fork)
641 child_inf->pspace = parent_pspace;
642 child_inf->aspace = child_inf->pspace->aspace;
646 child_inf->aspace = new_address_space ();
647 child_inf->pspace = add_program_space (child_inf->aspace);
648 child_inf->removable = 1;
649 child_inf->symfile_flags = SYMFILE_NO_READ;
650 set_current_program_space (child_inf->pspace);
651 clone_program_space (child_inf->pspace, parent_pspace);
653 /* Let the shared library layer (e.g., solib-svr4) learn
654 about this new process, relocate the cloned exec, pull in
655 shared libraries, and install the solib event breakpoint.
656 If a "cloned-VM" event was propagated better throughout
657 the core, this wouldn't be required. */
658 solib_create_inferior_hook (0);
662 return target_follow_fork (follow_child, detach_fork);
665 /* Tell the target to follow the fork we're stopped at. Returns true
666 if the inferior should be resumed; false, if the target for some
667 reason decided it's best not to resume. */
672 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
673 int should_resume = 1;
674 struct thread_info *tp;
676 /* Copy user stepping state to the new inferior thread. FIXME: the
677 followed fork child thread should have a copy of most of the
678 parent thread structure's run control related fields, not just these.
679 Initialized to avoid "may be used uninitialized" warnings from gcc. */
680 struct breakpoint *step_resume_breakpoint = NULL;
681 struct breakpoint *exception_resume_breakpoint = NULL;
682 CORE_ADDR step_range_start = 0;
683 CORE_ADDR step_range_end = 0;
684 struct frame_id step_frame_id = { 0 };
685 struct thread_fsm *thread_fsm = NULL;
690 struct target_waitstatus wait_status;
692 /* Get the last target status returned by target_wait(). */
693 get_last_target_status (&wait_ptid, &wait_status);
695 /* If not stopped at a fork event, then there's nothing else to
697 if (wait_status.kind != TARGET_WAITKIND_FORKED
698 && wait_status.kind != TARGET_WAITKIND_VFORKED)
701 /* Check if we switched over from WAIT_PTID, since the event was
703 if (!ptid_equal (wait_ptid, minus_one_ptid)
704 && !ptid_equal (inferior_ptid, wait_ptid))
706 /* We did. Switch back to WAIT_PTID thread, to tell the
707 target to follow it (in either direction). We'll
708 afterwards refuse to resume, and inform the user what
710 switch_to_thread (wait_ptid);
715 tp = inferior_thread ();
717 /* If there were any forks/vforks that were caught and are now to be
718 followed, then do so now. */
719 switch (tp->pending_follow.kind)
721 case TARGET_WAITKIND_FORKED:
722 case TARGET_WAITKIND_VFORKED:
724 ptid_t parent, child;
726 /* If the user did a next/step, etc, over a fork call,
727 preserve the stepping state in the fork child. */
728 if (follow_child && should_resume)
730 step_resume_breakpoint = clone_momentary_breakpoint
731 (tp->control.step_resume_breakpoint);
732 step_range_start = tp->control.step_range_start;
733 step_range_end = tp->control.step_range_end;
734 step_frame_id = tp->control.step_frame_id;
735 exception_resume_breakpoint
736 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
737 thread_fsm = tp->thread_fsm;
739 /* For now, delete the parent's sr breakpoint, otherwise,
740 parent/child sr breakpoints are considered duplicates,
741 and the child version will not be installed. Remove
742 this when the breakpoints module becomes aware of
743 inferiors and address spaces. */
744 delete_step_resume_breakpoint (tp);
745 tp->control.step_range_start = 0;
746 tp->control.step_range_end = 0;
747 tp->control.step_frame_id = null_frame_id;
748 delete_exception_resume_breakpoint (tp);
749 tp->thread_fsm = NULL;
752 parent = inferior_ptid;
753 child = tp->pending_follow.value.related_pid;
755 /* Set up inferior(s) as specified by the caller, and tell the
756 target to do whatever is necessary to follow either parent
758 if (follow_fork_inferior (follow_child, detach_fork))
760 /* Target refused to follow, or there's some other reason
761 we shouldn't resume. */
766 /* This pending follow fork event is now handled, one way
767 or another. The previous selected thread may be gone
768 from the lists by now, but if it is still around, need
769 to clear the pending follow request. */
770 tp = find_thread_ptid (parent);
772 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
774 /* This makes sure we don't try to apply the "Switched
775 over from WAIT_PID" logic above. */
776 nullify_last_target_wait_ptid ();
778 /* If we followed the child, switch to it... */
781 switch_to_thread (child);
783 /* ... and preserve the stepping state, in case the
784 user was stepping over the fork call. */
787 tp = inferior_thread ();
788 tp->control.step_resume_breakpoint
789 = step_resume_breakpoint;
790 tp->control.step_range_start = step_range_start;
791 tp->control.step_range_end = step_range_end;
792 tp->control.step_frame_id = step_frame_id;
793 tp->control.exception_resume_breakpoint
794 = exception_resume_breakpoint;
795 tp->thread_fsm = thread_fsm;
799 /* If we get here, it was because we're trying to
800 resume from a fork catchpoint, but, the user
801 has switched threads away from the thread that
802 forked. In that case, the resume command
803 issued is most likely not applicable to the
804 child, so just warn, and refuse to resume. */
805 warning (_("Not resuming: switched threads "
806 "before following fork child."));
809 /* Reset breakpoints in the child as appropriate. */
810 follow_inferior_reset_breakpoints ();
813 switch_to_thread (parent);
817 case TARGET_WAITKIND_SPURIOUS:
818 /* Nothing to follow. */
821 internal_error (__FILE__, __LINE__,
822 "Unexpected pending_follow.kind %d\n",
823 tp->pending_follow.kind);
827 return should_resume;
831 follow_inferior_reset_breakpoints (void)
833 struct thread_info *tp = inferior_thread ();
835 /* Was there a step_resume breakpoint? (There was if the user
836 did a "next" at the fork() call.) If so, explicitly reset its
837 thread number. Cloned step_resume breakpoints are disabled on
838 creation, so enable it here now that it is associated with the
841 step_resumes are a form of bp that are made to be per-thread.
842 Since we created the step_resume bp when the parent process
843 was being debugged, and now are switching to the child process,
844 from the breakpoint package's viewpoint, that's a switch of
845 "threads". We must update the bp's notion of which thread
846 it is for, or it'll be ignored when it triggers. */
848 if (tp->control.step_resume_breakpoint)
850 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
851 tp->control.step_resume_breakpoint->loc->enabled = 1;
854 /* Treat exception_resume breakpoints like step_resume breakpoints. */
855 if (tp->control.exception_resume_breakpoint)
857 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
858 tp->control.exception_resume_breakpoint->loc->enabled = 1;
861 /* Reinsert all breakpoints in the child. The user may have set
862 breakpoints after catching the fork, in which case those
863 were never set in the child, but only in the parent. This makes
864 sure the inserted breakpoints match the breakpoint list. */
866 breakpoint_re_set ();
867 insert_breakpoints ();
870 /* The child has exited or execed: resume threads of the parent the
871 user wanted to be executing. */
874 proceed_after_vfork_done (struct thread_info *thread,
877 int pid = * (int *) arg;
879 if (ptid_get_pid (thread->ptid) == pid
880 && is_running (thread->ptid)
881 && !is_executing (thread->ptid)
882 && !thread->stop_requested
883 && thread->suspend.stop_signal == GDB_SIGNAL_0)
886 fprintf_unfiltered (gdb_stdlog,
887 "infrun: resuming vfork parent thread %s\n",
888 target_pid_to_str (thread->ptid));
890 switch_to_thread (thread->ptid);
891 clear_proceed_status (0);
892 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
898 /* Save/restore inferior_ptid, current program space and current
899 inferior. Only use this if the current context points at an exited
900 inferior (and therefore there's no current thread to save). */
901 class scoped_restore_exited_inferior
904 scoped_restore_exited_inferior ()
905 : m_saved_ptid (&inferior_ptid)
909 scoped_restore_tmpl<ptid_t> m_saved_ptid;
910 scoped_restore_current_program_space m_pspace;
911 scoped_restore_current_inferior m_inferior;
914 /* Called whenever we notice an exec or exit event, to handle
915 detaching or resuming a vfork parent. */
918 handle_vfork_child_exec_or_exit (int exec)
920 struct inferior *inf = current_inferior ();
922 if (inf->vfork_parent)
924 int resume_parent = -1;
926 /* This exec or exit marks the end of the shared memory region
927 between the parent and the child. If the user wanted to
928 detach from the parent, now is the time. */
930 if (inf->vfork_parent->pending_detach)
932 struct thread_info *tp;
933 struct program_space *pspace;
934 struct address_space *aspace;
936 /* follow-fork child, detach-on-fork on. */
938 inf->vfork_parent->pending_detach = 0;
940 gdb::optional<scoped_restore_exited_inferior>
941 maybe_restore_inferior;
942 gdb::optional<scoped_restore_current_pspace_and_thread>
943 maybe_restore_thread;
945 /* If we're handling a child exit, then inferior_ptid points
946 at the inferior's pid, not to a thread. */
948 maybe_restore_inferior.emplace ();
950 maybe_restore_thread.emplace ();
952 /* We're letting loose of the parent. */
953 tp = any_live_thread_of_process (inf->vfork_parent->pid);
954 switch_to_thread (tp->ptid);
956 /* We're about to detach from the parent, which implicitly
957 removes breakpoints from its address space. There's a
958 catch here: we want to reuse the spaces for the child,
959 but, parent/child are still sharing the pspace at this
960 point, although the exec in reality makes the kernel give
961 the child a fresh set of new pages. The problem here is
962 that the breakpoints module being unaware of this, would
963 likely chose the child process to write to the parent
964 address space. Swapping the child temporarily away from
965 the spaces has the desired effect. Yes, this is "sort
968 pspace = inf->pspace;
969 aspace = inf->aspace;
973 if (debug_infrun || info_verbose)
975 target_terminal_ours_for_output ();
979 fprintf_filtered (gdb_stdlog,
980 _("Detaching vfork parent process "
981 "%d after child exec.\n"),
982 inf->vfork_parent->pid);
986 fprintf_filtered (gdb_stdlog,
987 _("Detaching vfork parent process "
988 "%d after child exit.\n"),
989 inf->vfork_parent->pid);
993 target_detach (NULL, 0);
996 inf->pspace = pspace;
997 inf->aspace = aspace;
1001 /* We're staying attached to the parent, so, really give the
1002 child a new address space. */
1003 inf->pspace = add_program_space (maybe_new_address_space ());
1004 inf->aspace = inf->pspace->aspace;
1006 set_current_program_space (inf->pspace);
1008 resume_parent = inf->vfork_parent->pid;
1010 /* Break the bonds. */
1011 inf->vfork_parent->vfork_child = NULL;
1015 struct program_space *pspace;
1017 /* If this is a vfork child exiting, then the pspace and
1018 aspaces were shared with the parent. Since we're
1019 reporting the process exit, we'll be mourning all that is
1020 found in the address space, and switching to null_ptid,
1021 preparing to start a new inferior. But, since we don't
1022 want to clobber the parent's address/program spaces, we
1023 go ahead and create a new one for this exiting
1026 /* Switch to null_ptid while running clone_program_space, so
1027 that clone_program_space doesn't want to read the
1028 selected frame of a dead process. */
1029 scoped_restore restore_ptid
1030 = make_scoped_restore (&inferior_ptid, null_ptid);
1032 /* This inferior is dead, so avoid giving the breakpoints
1033 module the option to write through to it (cloning a
1034 program space resets breakpoints). */
1037 pspace = add_program_space (maybe_new_address_space ());
1038 set_current_program_space (pspace);
1040 inf->symfile_flags = SYMFILE_NO_READ;
1041 clone_program_space (pspace, inf->vfork_parent->pspace);
1042 inf->pspace = pspace;
1043 inf->aspace = pspace->aspace;
1045 resume_parent = inf->vfork_parent->pid;
1046 /* Break the bonds. */
1047 inf->vfork_parent->vfork_child = NULL;
1050 inf->vfork_parent = NULL;
1052 gdb_assert (current_program_space == inf->pspace);
1054 if (non_stop && resume_parent != -1)
1056 /* If the user wanted the parent to be running, let it go
1058 scoped_restore_current_thread restore_thread;
1061 fprintf_unfiltered (gdb_stdlog,
1062 "infrun: resuming vfork parent process %d\n",
1065 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1070 /* Enum strings for "set|show follow-exec-mode". */
1072 static const char follow_exec_mode_new[] = "new";
1073 static const char follow_exec_mode_same[] = "same";
1074 static const char *const follow_exec_mode_names[] =
1076 follow_exec_mode_new,
1077 follow_exec_mode_same,
1081 static const char *follow_exec_mode_string = follow_exec_mode_same;
1083 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1084 struct cmd_list_element *c, const char *value)
1086 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1089 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1092 follow_exec (ptid_t ptid, char *exec_file_target)
1094 struct thread_info *th, *tmp;
1095 struct inferior *inf = current_inferior ();
1096 int pid = ptid_get_pid (ptid);
1097 ptid_t process_ptid;
1098 char *exec_file_host;
1099 struct cleanup *old_chain;
1101 /* This is an exec event that we actually wish to pay attention to.
1102 Refresh our symbol table to the newly exec'd program, remove any
1103 momentary bp's, etc.
1105 If there are breakpoints, they aren't really inserted now,
1106 since the exec() transformed our inferior into a fresh set
1109 We want to preserve symbolic breakpoints on the list, since
1110 we have hopes that they can be reset after the new a.out's
1111 symbol table is read.
1113 However, any "raw" breakpoints must be removed from the list
1114 (e.g., the solib bp's), since their address is probably invalid
1117 And, we DON'T want to call delete_breakpoints() here, since
1118 that may write the bp's "shadow contents" (the instruction
1119 value that was overwritten witha TRAP instruction). Since
1120 we now have a new a.out, those shadow contents aren't valid. */
1122 mark_breakpoints_out ();
1124 /* The target reports the exec event to the main thread, even if
1125 some other thread does the exec, and even if the main thread was
1126 stopped or already gone. We may still have non-leader threads of
1127 the process on our list. E.g., on targets that don't have thread
1128 exit events (like remote); or on native Linux in non-stop mode if
1129 there were only two threads in the inferior and the non-leader
1130 one is the one that execs (and nothing forces an update of the
1131 thread list up to here). When debugging remotely, it's best to
1132 avoid extra traffic, when possible, so avoid syncing the thread
1133 list with the target, and instead go ahead and delete all threads
1134 of the process but one that reported the event. Note this must
1135 be done before calling update_breakpoints_after_exec, as
1136 otherwise clearing the threads' resources would reference stale
1137 thread breakpoints -- it may have been one of these threads that
1138 stepped across the exec. We could just clear their stepping
1139 states, but as long as we're iterating, might as well delete
1140 them. Deleting them now rather than at the next user-visible
1141 stop provides a nicer sequence of events for user and MI
1143 ALL_THREADS_SAFE (th, tmp)
1144 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1145 delete_thread (th->ptid);
1147 /* We also need to clear any left over stale state for the
1148 leader/event thread. E.g., if there was any step-resume
1149 breakpoint or similar, it's gone now. We cannot truly
1150 step-to-next statement through an exec(). */
1151 th = inferior_thread ();
1152 th->control.step_resume_breakpoint = NULL;
1153 th->control.exception_resume_breakpoint = NULL;
1154 th->control.single_step_breakpoints = NULL;
1155 th->control.step_range_start = 0;
1156 th->control.step_range_end = 0;
1158 /* The user may have had the main thread held stopped in the
1159 previous image (e.g., schedlock on, or non-stop). Release
1161 th->stop_requested = 0;
1163 update_breakpoints_after_exec ();
1165 /* What is this a.out's name? */
1166 process_ptid = pid_to_ptid (pid);
1167 printf_unfiltered (_("%s is executing new program: %s\n"),
1168 target_pid_to_str (process_ptid),
1171 /* We've followed the inferior through an exec. Therefore, the
1172 inferior has essentially been killed & reborn. */
1174 gdb_flush (gdb_stdout);
1176 breakpoint_init_inferior (inf_execd);
1178 exec_file_host = exec_file_find (exec_file_target, NULL);
1179 old_chain = make_cleanup (xfree, exec_file_host);
1181 /* If we were unable to map the executable target pathname onto a host
1182 pathname, tell the user that. Otherwise GDB's subsequent behavior
1183 is confusing. Maybe it would even be better to stop at this point
1184 so that the user can specify a file manually before continuing. */
1185 if (exec_file_host == NULL)
1186 warning (_("Could not load symbols for executable %s.\n"
1187 "Do you need \"set sysroot\"?"),
1190 /* Reset the shared library package. This ensures that we get a
1191 shlib event when the child reaches "_start", at which point the
1192 dld will have had a chance to initialize the child. */
1193 /* Also, loading a symbol file below may trigger symbol lookups, and
1194 we don't want those to be satisfied by the libraries of the
1195 previous incarnation of this process. */
1196 no_shared_libraries (NULL, 0);
1198 if (follow_exec_mode_string == follow_exec_mode_new)
1200 /* The user wants to keep the old inferior and program spaces
1201 around. Create a new fresh one, and switch to it. */
1203 /* Do exit processing for the original inferior before adding
1204 the new inferior so we don't have two active inferiors with
1205 the same ptid, which can confuse find_inferior_ptid. */
1206 exit_inferior_num_silent (current_inferior ()->num);
1208 inf = add_inferior_with_spaces ();
1210 target_follow_exec (inf, exec_file_target);
1212 set_current_inferior (inf);
1213 set_current_program_space (inf->pspace);
1218 /* The old description may no longer be fit for the new image.
1219 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1220 old description; we'll read a new one below. No need to do
1221 this on "follow-exec-mode new", as the old inferior stays
1222 around (its description is later cleared/refetched on
1224 target_clear_description ();
1227 gdb_assert (current_program_space == inf->pspace);
1229 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1230 because the proper displacement for a PIE (Position Independent
1231 Executable) main symbol file will only be computed by
1232 solib_create_inferior_hook below. breakpoint_re_set would fail
1233 to insert the breakpoints with the zero displacement. */
1234 try_open_exec_file (exec_file_host, inf, SYMFILE_DEFER_BP_RESET);
1236 do_cleanups (old_chain);
1238 /* If the target can specify a description, read it. Must do this
1239 after flipping to the new executable (because the target supplied
1240 description must be compatible with the executable's
1241 architecture, and the old executable may e.g., be 32-bit, while
1242 the new one 64-bit), and before anything involving memory or
1244 target_find_description ();
1246 solib_create_inferior_hook (0);
1248 jit_inferior_created_hook ();
1250 breakpoint_re_set ();
1252 /* Reinsert all breakpoints. (Those which were symbolic have
1253 been reset to the proper address in the new a.out, thanks
1254 to symbol_file_command...). */
1255 insert_breakpoints ();
1257 /* The next resume of this inferior should bring it to the shlib
1258 startup breakpoints. (If the user had also set bp's on
1259 "main" from the old (parent) process, then they'll auto-
1260 matically get reset there in the new process.). */
1263 /* The queue of threads that need to do a step-over operation to get
1264 past e.g., a breakpoint. What technique is used to step over the
1265 breakpoint/watchpoint does not matter -- all threads end up in the
1266 same queue, to maintain rough temporal order of execution, in order
1267 to avoid starvation, otherwise, we could e.g., find ourselves
1268 constantly stepping the same couple threads past their breakpoints
1269 over and over, if the single-step finish fast enough. */
1270 struct thread_info *step_over_queue_head;
1272 /* Bit flags indicating what the thread needs to step over. */
1274 enum step_over_what_flag
1276 /* Step over a breakpoint. */
1277 STEP_OVER_BREAKPOINT = 1,
1279 /* Step past a non-continuable watchpoint, in order to let the
1280 instruction execute so we can evaluate the watchpoint
1282 STEP_OVER_WATCHPOINT = 2
1284 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1286 /* Info about an instruction that is being stepped over. */
1288 struct step_over_info
1290 /* If we're stepping past a breakpoint, this is the address space
1291 and address of the instruction the breakpoint is set at. We'll
1292 skip inserting all breakpoints here. Valid iff ASPACE is
1294 struct address_space *aspace;
1297 /* The instruction being stepped over triggers a nonsteppable
1298 watchpoint. If true, we'll skip inserting watchpoints. */
1299 int nonsteppable_watchpoint_p;
1301 /* The thread's global number. */
1305 /* The step-over info of the location that is being stepped over.
1307 Note that with async/breakpoint always-inserted mode, a user might
1308 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1309 being stepped over. As setting a new breakpoint inserts all
1310 breakpoints, we need to make sure the breakpoint being stepped over
1311 isn't inserted then. We do that by only clearing the step-over
1312 info when the step-over is actually finished (or aborted).
1314 Presently GDB can only step over one breakpoint at any given time.
1315 Given threads that can't run code in the same address space as the
1316 breakpoint's can't really miss the breakpoint, GDB could be taught
1317 to step-over at most one breakpoint per address space (so this info
1318 could move to the address space object if/when GDB is extended).
1319 The set of breakpoints being stepped over will normally be much
1320 smaller than the set of all breakpoints, so a flag in the
1321 breakpoint location structure would be wasteful. A separate list
1322 also saves complexity and run-time, as otherwise we'd have to go
1323 through all breakpoint locations clearing their flag whenever we
1324 start a new sequence. Similar considerations weigh against storing
1325 this info in the thread object. Plus, not all step overs actually
1326 have breakpoint locations -- e.g., stepping past a single-step
1327 breakpoint, or stepping to complete a non-continuable
1329 static struct step_over_info step_over_info;
1331 /* Record the address of the breakpoint/instruction we're currently
1333 N.B. We record the aspace and address now, instead of say just the thread,
1334 because when we need the info later the thread may be running. */
1337 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1338 int nonsteppable_watchpoint_p,
1341 step_over_info.aspace = aspace;
1342 step_over_info.address = address;
1343 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1344 step_over_info.thread = thread;
1347 /* Called when we're not longer stepping over a breakpoint / an
1348 instruction, so all breakpoints are free to be (re)inserted. */
1351 clear_step_over_info (void)
1354 fprintf_unfiltered (gdb_stdlog,
1355 "infrun: clear_step_over_info\n");
1356 step_over_info.aspace = NULL;
1357 step_over_info.address = 0;
1358 step_over_info.nonsteppable_watchpoint_p = 0;
1359 step_over_info.thread = -1;
1365 stepping_past_instruction_at (struct address_space *aspace,
1368 return (step_over_info.aspace != NULL
1369 && breakpoint_address_match (aspace, address,
1370 step_over_info.aspace,
1371 step_over_info.address));
1377 thread_is_stepping_over_breakpoint (int thread)
1379 return (step_over_info.thread != -1
1380 && thread == step_over_info.thread);
1386 stepping_past_nonsteppable_watchpoint (void)
1388 return step_over_info.nonsteppable_watchpoint_p;
1391 /* Returns true if step-over info is valid. */
1394 step_over_info_valid_p (void)
1396 return (step_over_info.aspace != NULL
1397 || stepping_past_nonsteppable_watchpoint ());
1401 /* Displaced stepping. */
1403 /* In non-stop debugging mode, we must take special care to manage
1404 breakpoints properly; in particular, the traditional strategy for
1405 stepping a thread past a breakpoint it has hit is unsuitable.
1406 'Displaced stepping' is a tactic for stepping one thread past a
1407 breakpoint it has hit while ensuring that other threads running
1408 concurrently will hit the breakpoint as they should.
1410 The traditional way to step a thread T off a breakpoint in a
1411 multi-threaded program in all-stop mode is as follows:
1413 a0) Initially, all threads are stopped, and breakpoints are not
1415 a1) We single-step T, leaving breakpoints uninserted.
1416 a2) We insert breakpoints, and resume all threads.
1418 In non-stop debugging, however, this strategy is unsuitable: we
1419 don't want to have to stop all threads in the system in order to
1420 continue or step T past a breakpoint. Instead, we use displaced
1423 n0) Initially, T is stopped, other threads are running, and
1424 breakpoints are inserted.
1425 n1) We copy the instruction "under" the breakpoint to a separate
1426 location, outside the main code stream, making any adjustments
1427 to the instruction, register, and memory state as directed by
1429 n2) We single-step T over the instruction at its new location.
1430 n3) We adjust the resulting register and memory state as directed
1431 by T's architecture. This includes resetting T's PC to point
1432 back into the main instruction stream.
1435 This approach depends on the following gdbarch methods:
1437 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1438 indicate where to copy the instruction, and how much space must
1439 be reserved there. We use these in step n1.
1441 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1442 address, and makes any necessary adjustments to the instruction,
1443 register contents, and memory. We use this in step n1.
1445 - gdbarch_displaced_step_fixup adjusts registers and memory after
1446 we have successfuly single-stepped the instruction, to yield the
1447 same effect the instruction would have had if we had executed it
1448 at its original address. We use this in step n3.
1450 - gdbarch_displaced_step_free_closure provides cleanup.
1452 The gdbarch_displaced_step_copy_insn and
1453 gdbarch_displaced_step_fixup functions must be written so that
1454 copying an instruction with gdbarch_displaced_step_copy_insn,
1455 single-stepping across the copied instruction, and then applying
1456 gdbarch_displaced_insn_fixup should have the same effects on the
1457 thread's memory and registers as stepping the instruction in place
1458 would have. Exactly which responsibilities fall to the copy and
1459 which fall to the fixup is up to the author of those functions.
1461 See the comments in gdbarch.sh for details.
1463 Note that displaced stepping and software single-step cannot
1464 currently be used in combination, although with some care I think
1465 they could be made to. Software single-step works by placing
1466 breakpoints on all possible subsequent instructions; if the
1467 displaced instruction is a PC-relative jump, those breakpoints
1468 could fall in very strange places --- on pages that aren't
1469 executable, or at addresses that are not proper instruction
1470 boundaries. (We do generally let other threads run while we wait
1471 to hit the software single-step breakpoint, and they might
1472 encounter such a corrupted instruction.) One way to work around
1473 this would be to have gdbarch_displaced_step_copy_insn fully
1474 simulate the effect of PC-relative instructions (and return NULL)
1475 on architectures that use software single-stepping.
1477 In non-stop mode, we can have independent and simultaneous step
1478 requests, so more than one thread may need to simultaneously step
1479 over a breakpoint. The current implementation assumes there is
1480 only one scratch space per process. In this case, we have to
1481 serialize access to the scratch space. If thread A wants to step
1482 over a breakpoint, but we are currently waiting for some other
1483 thread to complete a displaced step, we leave thread A stopped and
1484 place it in the displaced_step_request_queue. Whenever a displaced
1485 step finishes, we pick the next thread in the queue and start a new
1486 displaced step operation on it. See displaced_step_prepare and
1487 displaced_step_fixup for details. */
1489 /* Per-inferior displaced stepping state. */
1490 struct displaced_step_inferior_state
1492 /* Pointer to next in linked list. */
1493 struct displaced_step_inferior_state *next;
1495 /* The process this displaced step state refers to. */
1498 /* True if preparing a displaced step ever failed. If so, we won't
1499 try displaced stepping for this inferior again. */
1502 /* If this is not null_ptid, this is the thread carrying out a
1503 displaced single-step in process PID. This thread's state will
1504 require fixing up once it has completed its step. */
1507 /* The architecture the thread had when we stepped it. */
1508 struct gdbarch *step_gdbarch;
1510 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1511 for post-step cleanup. */
1512 struct displaced_step_closure *step_closure;
1514 /* The address of the original instruction, and the copy we
1516 CORE_ADDR step_original, step_copy;
1518 /* Saved contents of copy area. */
1519 gdb_byte *step_saved_copy;
1522 /* The list of states of processes involved in displaced stepping
1524 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1526 /* Get the displaced stepping state of process PID. */
1528 static struct displaced_step_inferior_state *
1529 get_displaced_stepping_state (int pid)
1531 struct displaced_step_inferior_state *state;
1533 for (state = displaced_step_inferior_states;
1535 state = state->next)
1536 if (state->pid == pid)
1542 /* Returns true if any inferior has a thread doing a displaced
1546 displaced_step_in_progress_any_inferior (void)
1548 struct displaced_step_inferior_state *state;
1550 for (state = displaced_step_inferior_states;
1552 state = state->next)
1553 if (!ptid_equal (state->step_ptid, null_ptid))
1559 /* Return true if thread represented by PTID is doing a displaced
1563 displaced_step_in_progress_thread (ptid_t ptid)
1565 struct displaced_step_inferior_state *displaced;
1567 gdb_assert (!ptid_equal (ptid, null_ptid));
1569 displaced = get_displaced_stepping_state (ptid_get_pid (ptid));
1571 return (displaced != NULL && ptid_equal (displaced->step_ptid, ptid));
1574 /* Return true if process PID has a thread doing a displaced step. */
1577 displaced_step_in_progress (int pid)
1579 struct displaced_step_inferior_state *displaced;
1581 displaced = get_displaced_stepping_state (pid);
1582 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1588 /* Add a new displaced stepping state for process PID to the displaced
1589 stepping state list, or return a pointer to an already existing
1590 entry, if it already exists. Never returns NULL. */
1592 static struct displaced_step_inferior_state *
1593 add_displaced_stepping_state (int pid)
1595 struct displaced_step_inferior_state *state;
1597 for (state = displaced_step_inferior_states;
1599 state = state->next)
1600 if (state->pid == pid)
1603 state = XCNEW (struct displaced_step_inferior_state);
1605 state->next = displaced_step_inferior_states;
1606 displaced_step_inferior_states = state;
1611 /* If inferior is in displaced stepping, and ADDR equals to starting address
1612 of copy area, return corresponding displaced_step_closure. Otherwise,
1615 struct displaced_step_closure*
1616 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1618 struct displaced_step_inferior_state *displaced
1619 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1621 /* If checking the mode of displaced instruction in copy area. */
1622 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1623 && (displaced->step_copy == addr))
1624 return displaced->step_closure;
1629 /* Remove the displaced stepping state of process PID. */
1632 remove_displaced_stepping_state (int pid)
1634 struct displaced_step_inferior_state *it, **prev_next_p;
1636 gdb_assert (pid != 0);
1638 it = displaced_step_inferior_states;
1639 prev_next_p = &displaced_step_inferior_states;
1644 *prev_next_p = it->next;
1649 prev_next_p = &it->next;
1655 infrun_inferior_exit (struct inferior *inf)
1657 remove_displaced_stepping_state (inf->pid);
1660 /* If ON, and the architecture supports it, GDB will use displaced
1661 stepping to step over breakpoints. If OFF, or if the architecture
1662 doesn't support it, GDB will instead use the traditional
1663 hold-and-step approach. If AUTO (which is the default), GDB will
1664 decide which technique to use to step over breakpoints depending on
1665 which of all-stop or non-stop mode is active --- displaced stepping
1666 in non-stop mode; hold-and-step in all-stop mode. */
1668 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1671 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1672 struct cmd_list_element *c,
1675 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1676 fprintf_filtered (file,
1677 _("Debugger's willingness to use displaced stepping "
1678 "to step over breakpoints is %s (currently %s).\n"),
1679 value, target_is_non_stop_p () ? "on" : "off");
1681 fprintf_filtered (file,
1682 _("Debugger's willingness to use displaced stepping "
1683 "to step over breakpoints is %s.\n"), value);
1686 /* Return non-zero if displaced stepping can/should be used to step
1687 over breakpoints of thread TP. */
1690 use_displaced_stepping (struct thread_info *tp)
1692 struct regcache *regcache = get_thread_regcache (tp->ptid);
1693 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1694 struct displaced_step_inferior_state *displaced_state;
1696 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
1698 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1699 && target_is_non_stop_p ())
1700 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1701 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1702 && find_record_target () == NULL
1703 && (displaced_state == NULL
1704 || !displaced_state->failed_before));
1707 /* Clean out any stray displaced stepping state. */
1709 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1711 /* Indicate that there is no cleanup pending. */
1712 displaced->step_ptid = null_ptid;
1714 xfree (displaced->step_closure);
1715 displaced->step_closure = NULL;
1719 displaced_step_clear_cleanup (void *arg)
1721 struct displaced_step_inferior_state *state
1722 = (struct displaced_step_inferior_state *) arg;
1724 displaced_step_clear (state);
1727 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1729 displaced_step_dump_bytes (struct ui_file *file,
1730 const gdb_byte *buf,
1735 for (i = 0; i < len; i++)
1736 fprintf_unfiltered (file, "%02x ", buf[i]);
1737 fputs_unfiltered ("\n", file);
1740 /* Prepare to single-step, using displaced stepping.
1742 Note that we cannot use displaced stepping when we have a signal to
1743 deliver. If we have a signal to deliver and an instruction to step
1744 over, then after the step, there will be no indication from the
1745 target whether the thread entered a signal handler or ignored the
1746 signal and stepped over the instruction successfully --- both cases
1747 result in a simple SIGTRAP. In the first case we mustn't do a
1748 fixup, and in the second case we must --- but we can't tell which.
1749 Comments in the code for 'random signals' in handle_inferior_event
1750 explain how we handle this case instead.
1752 Returns 1 if preparing was successful -- this thread is going to be
1753 stepped now; 0 if displaced stepping this thread got queued; or -1
1754 if this instruction can't be displaced stepped. */
1757 displaced_step_prepare_throw (ptid_t ptid)
1759 struct cleanup *ignore_cleanups;
1760 struct thread_info *tp = find_thread_ptid (ptid);
1761 struct regcache *regcache = get_thread_regcache (ptid);
1762 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1763 struct address_space *aspace = get_regcache_aspace (regcache);
1764 CORE_ADDR original, copy;
1766 struct displaced_step_closure *closure;
1767 struct displaced_step_inferior_state *displaced;
1770 /* We should never reach this function if the architecture does not
1771 support displaced stepping. */
1772 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1774 /* Nor if the thread isn't meant to step over a breakpoint. */
1775 gdb_assert (tp->control.trap_expected);
1777 /* Disable range stepping while executing in the scratch pad. We
1778 want a single-step even if executing the displaced instruction in
1779 the scratch buffer lands within the stepping range (e.g., a
1781 tp->control.may_range_step = 0;
1783 /* We have to displaced step one thread at a time, as we only have
1784 access to a single scratch space per inferior. */
1786 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1788 if (!ptid_equal (displaced->step_ptid, null_ptid))
1790 /* Already waiting for a displaced step to finish. Defer this
1791 request and place in queue. */
1793 if (debug_displaced)
1794 fprintf_unfiltered (gdb_stdlog,
1795 "displaced: deferring step of %s\n",
1796 target_pid_to_str (ptid));
1798 thread_step_over_chain_enqueue (tp);
1803 if (debug_displaced)
1804 fprintf_unfiltered (gdb_stdlog,
1805 "displaced: stepping %s now\n",
1806 target_pid_to_str (ptid));
1809 displaced_step_clear (displaced);
1811 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1812 inferior_ptid = ptid;
1814 original = regcache_read_pc (regcache);
1816 copy = gdbarch_displaced_step_location (gdbarch);
1817 len = gdbarch_max_insn_length (gdbarch);
1819 if (breakpoint_in_range_p (aspace, copy, len))
1821 /* There's a breakpoint set in the scratch pad location range
1822 (which is usually around the entry point). We'd either
1823 install it before resuming, which would overwrite/corrupt the
1824 scratch pad, or if it was already inserted, this displaced
1825 step would overwrite it. The latter is OK in the sense that
1826 we already assume that no thread is going to execute the code
1827 in the scratch pad range (after initial startup) anyway, but
1828 the former is unacceptable. Simply punt and fallback to
1829 stepping over this breakpoint in-line. */
1830 if (debug_displaced)
1832 fprintf_unfiltered (gdb_stdlog,
1833 "displaced: breakpoint set in scratch pad. "
1834 "Stepping over breakpoint in-line instead.\n");
1840 /* Save the original contents of the copy area. */
1841 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1842 ignore_cleanups = make_cleanup (free_current_contents,
1843 &displaced->step_saved_copy);
1844 status = target_read_memory (copy, displaced->step_saved_copy, len);
1846 throw_error (MEMORY_ERROR,
1847 _("Error accessing memory address %s (%s) for "
1848 "displaced-stepping scratch space."),
1849 paddress (gdbarch, copy), safe_strerror (status));
1850 if (debug_displaced)
1852 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1853 paddress (gdbarch, copy));
1854 displaced_step_dump_bytes (gdb_stdlog,
1855 displaced->step_saved_copy,
1859 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1860 original, copy, regcache);
1861 if (closure == NULL)
1863 /* The architecture doesn't know how or want to displaced step
1864 this instruction or instruction sequence. Fallback to
1865 stepping over the breakpoint in-line. */
1866 do_cleanups (ignore_cleanups);
1870 /* Save the information we need to fix things up if the step
1872 displaced->step_ptid = ptid;
1873 displaced->step_gdbarch = gdbarch;
1874 displaced->step_closure = closure;
1875 displaced->step_original = original;
1876 displaced->step_copy = copy;
1878 make_cleanup (displaced_step_clear_cleanup, displaced);
1880 /* Resume execution at the copy. */
1881 regcache_write_pc (regcache, copy);
1883 discard_cleanups (ignore_cleanups);
1885 if (debug_displaced)
1886 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1887 paddress (gdbarch, copy));
1892 /* Wrapper for displaced_step_prepare_throw that disabled further
1893 attempts at displaced stepping if we get a memory error. */
1896 displaced_step_prepare (ptid_t ptid)
1902 prepared = displaced_step_prepare_throw (ptid);
1904 CATCH (ex, RETURN_MASK_ERROR)
1906 struct displaced_step_inferior_state *displaced_state;
1908 if (ex.error != MEMORY_ERROR
1909 && ex.error != NOT_SUPPORTED_ERROR)
1910 throw_exception (ex);
1914 fprintf_unfiltered (gdb_stdlog,
1915 "infrun: disabling displaced stepping: %s\n",
1919 /* Be verbose if "set displaced-stepping" is "on", silent if
1921 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1923 warning (_("disabling displaced stepping: %s"),
1927 /* Disable further displaced stepping attempts. */
1929 = get_displaced_stepping_state (ptid_get_pid (ptid));
1930 displaced_state->failed_before = 1;
1938 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1939 const gdb_byte *myaddr, int len)
1941 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1943 inferior_ptid = ptid;
1944 write_memory (memaddr, myaddr, len);
1947 /* Restore the contents of the copy area for thread PTID. */
1950 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1953 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1955 write_memory_ptid (ptid, displaced->step_copy,
1956 displaced->step_saved_copy, len);
1957 if (debug_displaced)
1958 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1959 target_pid_to_str (ptid),
1960 paddress (displaced->step_gdbarch,
1961 displaced->step_copy));
1964 /* If we displaced stepped an instruction successfully, adjust
1965 registers and memory to yield the same effect the instruction would
1966 have had if we had executed it at its original address, and return
1967 1. If the instruction didn't complete, relocate the PC and return
1968 -1. If the thread wasn't displaced stepping, return 0. */
1971 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1973 struct cleanup *old_cleanups;
1974 struct displaced_step_inferior_state *displaced
1975 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1978 /* Was any thread of this process doing a displaced step? */
1979 if (displaced == NULL)
1982 /* Was this event for the pid we displaced? */
1983 if (ptid_equal (displaced->step_ptid, null_ptid)
1984 || ! ptid_equal (displaced->step_ptid, event_ptid))
1987 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1989 displaced_step_restore (displaced, displaced->step_ptid);
1991 /* Fixup may need to read memory/registers. Switch to the thread
1992 that we're fixing up. Also, target_stopped_by_watchpoint checks
1993 the current thread. */
1994 switch_to_thread (event_ptid);
1996 /* Did the instruction complete successfully? */
1997 if (signal == GDB_SIGNAL_TRAP
1998 && !(target_stopped_by_watchpoint ()
1999 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
2000 || target_have_steppable_watchpoint)))
2002 /* Fix up the resulting state. */
2003 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
2004 displaced->step_closure,
2005 displaced->step_original,
2006 displaced->step_copy,
2007 get_thread_regcache (displaced->step_ptid));
2012 /* Since the instruction didn't complete, all we can do is
2014 struct regcache *regcache = get_thread_regcache (event_ptid);
2015 CORE_ADDR pc = regcache_read_pc (regcache);
2017 pc = displaced->step_original + (pc - displaced->step_copy);
2018 regcache_write_pc (regcache, pc);
2022 do_cleanups (old_cleanups);
2024 displaced->step_ptid = null_ptid;
2029 /* Data to be passed around while handling an event. This data is
2030 discarded between events. */
2031 struct execution_control_state
2034 /* The thread that got the event, if this was a thread event; NULL
2036 struct thread_info *event_thread;
2038 struct target_waitstatus ws;
2039 int stop_func_filled_in;
2040 CORE_ADDR stop_func_start;
2041 CORE_ADDR stop_func_end;
2042 const char *stop_func_name;
2045 /* True if the event thread hit the single-step breakpoint of
2046 another thread. Thus the event doesn't cause a stop, the thread
2047 needs to be single-stepped past the single-step breakpoint before
2048 we can switch back to the original stepping thread. */
2049 int hit_singlestep_breakpoint;
2052 /* Clear ECS and set it to point at TP. */
2055 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2057 memset (ecs, 0, sizeof (*ecs));
2058 ecs->event_thread = tp;
2059 ecs->ptid = tp->ptid;
2062 static void keep_going_pass_signal (struct execution_control_state *ecs);
2063 static void prepare_to_wait (struct execution_control_state *ecs);
2064 static int keep_going_stepped_thread (struct thread_info *tp);
2065 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2067 /* Are there any pending step-over requests? If so, run all we can
2068 now and return true. Otherwise, return false. */
2071 start_step_over (void)
2073 struct thread_info *tp, *next;
2075 /* Don't start a new step-over if we already have an in-line
2076 step-over operation ongoing. */
2077 if (step_over_info_valid_p ())
2080 for (tp = step_over_queue_head; tp != NULL; tp = next)
2082 struct execution_control_state ecss;
2083 struct execution_control_state *ecs = &ecss;
2084 step_over_what step_what;
2085 int must_be_in_line;
2087 gdb_assert (!tp->stop_requested);
2089 next = thread_step_over_chain_next (tp);
2091 /* If this inferior already has a displaced step in process,
2092 don't start a new one. */
2093 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2096 step_what = thread_still_needs_step_over (tp);
2097 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2098 || ((step_what & STEP_OVER_BREAKPOINT)
2099 && !use_displaced_stepping (tp)));
2101 /* We currently stop all threads of all processes to step-over
2102 in-line. If we need to start a new in-line step-over, let
2103 any pending displaced steps finish first. */
2104 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2107 thread_step_over_chain_remove (tp);
2109 if (step_over_queue_head == NULL)
2112 fprintf_unfiltered (gdb_stdlog,
2113 "infrun: step-over queue now empty\n");
2116 if (tp->control.trap_expected
2120 internal_error (__FILE__, __LINE__,
2121 "[%s] has inconsistent state: "
2122 "trap_expected=%d, resumed=%d, executing=%d\n",
2123 target_pid_to_str (tp->ptid),
2124 tp->control.trap_expected,
2130 fprintf_unfiltered (gdb_stdlog,
2131 "infrun: resuming [%s] for step-over\n",
2132 target_pid_to_str (tp->ptid));
2134 /* keep_going_pass_signal skips the step-over if the breakpoint
2135 is no longer inserted. In all-stop, we want to keep looking
2136 for a thread that needs a step-over instead of resuming TP,
2137 because we wouldn't be able to resume anything else until the
2138 target stops again. In non-stop, the resume always resumes
2139 only TP, so it's OK to let the thread resume freely. */
2140 if (!target_is_non_stop_p () && !step_what)
2143 switch_to_thread (tp->ptid);
2144 reset_ecs (ecs, tp);
2145 keep_going_pass_signal (ecs);
2147 if (!ecs->wait_some_more)
2148 error (_("Command aborted."));
2150 gdb_assert (tp->resumed);
2152 /* If we started a new in-line step-over, we're done. */
2153 if (step_over_info_valid_p ())
2155 gdb_assert (tp->control.trap_expected);
2159 if (!target_is_non_stop_p ())
2161 /* On all-stop, shouldn't have resumed unless we needed a
2163 gdb_assert (tp->control.trap_expected
2164 || tp->step_after_step_resume_breakpoint);
2166 /* With remote targets (at least), in all-stop, we can't
2167 issue any further remote commands until the program stops
2172 /* Either the thread no longer needed a step-over, or a new
2173 displaced stepping sequence started. Even in the latter
2174 case, continue looking. Maybe we can also start another
2175 displaced step on a thread of other process. */
2181 /* Update global variables holding ptids to hold NEW_PTID if they were
2182 holding OLD_PTID. */
2184 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2186 struct displaced_step_inferior_state *displaced;
2188 if (ptid_equal (inferior_ptid, old_ptid))
2189 inferior_ptid = new_ptid;
2191 for (displaced = displaced_step_inferior_states;
2193 displaced = displaced->next)
2195 if (ptid_equal (displaced->step_ptid, old_ptid))
2196 displaced->step_ptid = new_ptid;
2203 /* Things to clean up if we QUIT out of resume (). */
2205 resume_cleanups (void *ignore)
2207 if (!ptid_equal (inferior_ptid, null_ptid))
2208 delete_single_step_breakpoints (inferior_thread ());
2213 static const char schedlock_off[] = "off";
2214 static const char schedlock_on[] = "on";
2215 static const char schedlock_step[] = "step";
2216 static const char schedlock_replay[] = "replay";
2217 static const char *const scheduler_enums[] = {
2224 static const char *scheduler_mode = schedlock_replay;
2226 show_scheduler_mode (struct ui_file *file, int from_tty,
2227 struct cmd_list_element *c, const char *value)
2229 fprintf_filtered (file,
2230 _("Mode for locking scheduler "
2231 "during execution is \"%s\".\n"),
2236 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2238 if (!target_can_lock_scheduler)
2240 scheduler_mode = schedlock_off;
2241 error (_("Target '%s' cannot support this command."), target_shortname);
2245 /* True if execution commands resume all threads of all processes by
2246 default; otherwise, resume only threads of the current inferior
2248 int sched_multi = 0;
2250 /* Try to setup for software single stepping over the specified location.
2251 Return 1 if target_resume() should use hardware single step.
2253 GDBARCH the current gdbarch.
2254 PC the location to step over. */
2257 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2261 if (execution_direction == EXEC_FORWARD
2262 && gdbarch_software_single_step_p (gdbarch))
2263 hw_step = !insert_single_step_breakpoints (gdbarch);
2271 user_visible_resume_ptid (int step)
2277 /* With non-stop mode on, threads are always handled
2279 resume_ptid = inferior_ptid;
2281 else if ((scheduler_mode == schedlock_on)
2282 || (scheduler_mode == schedlock_step && step))
2284 /* User-settable 'scheduler' mode requires solo thread
2286 resume_ptid = inferior_ptid;
2288 else if ((scheduler_mode == schedlock_replay)
2289 && target_record_will_replay (minus_one_ptid, execution_direction))
2291 /* User-settable 'scheduler' mode requires solo thread resume in replay
2293 resume_ptid = inferior_ptid;
2295 else if (!sched_multi && target_supports_multi_process ())
2297 /* Resume all threads of the current process (and none of other
2299 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2303 /* Resume all threads of all processes. */
2304 resume_ptid = RESUME_ALL;
2310 /* Return a ptid representing the set of threads that we will resume,
2311 in the perspective of the target, assuming run control handling
2312 does not require leaving some threads stopped (e.g., stepping past
2313 breakpoint). USER_STEP indicates whether we're about to start the
2314 target for a stepping command. */
2317 internal_resume_ptid (int user_step)
2319 /* In non-stop, we always control threads individually. Note that
2320 the target may always work in non-stop mode even with "set
2321 non-stop off", in which case user_visible_resume_ptid could
2322 return a wildcard ptid. */
2323 if (target_is_non_stop_p ())
2324 return inferior_ptid;
2326 return user_visible_resume_ptid (user_step);
2329 /* Wrapper for target_resume, that handles infrun-specific
2333 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2335 struct thread_info *tp = inferior_thread ();
2337 gdb_assert (!tp->stop_requested);
2339 /* Install inferior's terminal modes. */
2340 target_terminal_inferior ();
2342 /* Avoid confusing the next resume, if the next stop/resume
2343 happens to apply to another thread. */
2344 tp->suspend.stop_signal = GDB_SIGNAL_0;
2346 /* Advise target which signals may be handled silently.
2348 If we have removed breakpoints because we are stepping over one
2349 in-line (in any thread), we need to receive all signals to avoid
2350 accidentally skipping a breakpoint during execution of a signal
2353 Likewise if we're displaced stepping, otherwise a trap for a
2354 breakpoint in a signal handler might be confused with the
2355 displaced step finishing. We don't make the displaced_step_fixup
2356 step distinguish the cases instead, because:
2358 - a backtrace while stopped in the signal handler would show the
2359 scratch pad as frame older than the signal handler, instead of
2360 the real mainline code.
2362 - when the thread is later resumed, the signal handler would
2363 return to the scratch pad area, which would no longer be
2365 if (step_over_info_valid_p ()
2366 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2367 target_pass_signals (0, NULL);
2369 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2371 target_resume (resume_ptid, step, sig);
2373 target_commit_resume ();
2376 /* Resume the inferior, but allow a QUIT. This is useful if the user
2377 wants to interrupt some lengthy single-stepping operation
2378 (for child processes, the SIGINT goes to the inferior, and so
2379 we get a SIGINT random_signal, but for remote debugging and perhaps
2380 other targets, that's not true).
2382 SIG is the signal to give the inferior (zero for none). */
2384 resume (enum gdb_signal sig)
2386 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2387 struct regcache *regcache = get_current_regcache ();
2388 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2389 struct thread_info *tp = inferior_thread ();
2390 CORE_ADDR pc = regcache_read_pc (regcache);
2391 struct address_space *aspace = get_regcache_aspace (regcache);
2393 /* This represents the user's step vs continue request. When
2394 deciding whether "set scheduler-locking step" applies, it's the
2395 user's intention that counts. */
2396 const int user_step = tp->control.stepping_command;
2397 /* This represents what we'll actually request the target to do.
2398 This can decay from a step to a continue, if e.g., we need to
2399 implement single-stepping with breakpoints (software
2403 gdb_assert (!tp->stop_requested);
2404 gdb_assert (!thread_is_in_step_over_chain (tp));
2408 if (tp->suspend.waitstatus_pending_p)
2413 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2415 fprintf_unfiltered (gdb_stdlog,
2416 "infrun: resume: thread %s has pending wait "
2417 "status %s (currently_stepping=%d).\n",
2418 target_pid_to_str (tp->ptid), statstr.c_str (),
2419 currently_stepping (tp));
2424 /* FIXME: What should we do if we are supposed to resume this
2425 thread with a signal? Maybe we should maintain a queue of
2426 pending signals to deliver. */
2427 if (sig != GDB_SIGNAL_0)
2429 warning (_("Couldn't deliver signal %s to %s."),
2430 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2433 tp->suspend.stop_signal = GDB_SIGNAL_0;
2434 discard_cleanups (old_cleanups);
2436 if (target_can_async_p ())
2441 tp->stepped_breakpoint = 0;
2443 /* Depends on stepped_breakpoint. */
2444 step = currently_stepping (tp);
2446 if (current_inferior ()->waiting_for_vfork_done)
2448 /* Don't try to single-step a vfork parent that is waiting for
2449 the child to get out of the shared memory region (by exec'ing
2450 or exiting). This is particularly important on software
2451 single-step archs, as the child process would trip on the
2452 software single step breakpoint inserted for the parent
2453 process. Since the parent will not actually execute any
2454 instruction until the child is out of the shared region (such
2455 are vfork's semantics), it is safe to simply continue it.
2456 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2457 the parent, and tell it to `keep_going', which automatically
2458 re-sets it stepping. */
2460 fprintf_unfiltered (gdb_stdlog,
2461 "infrun: resume : clear step\n");
2466 fprintf_unfiltered (gdb_stdlog,
2467 "infrun: resume (step=%d, signal=%s), "
2468 "trap_expected=%d, current thread [%s] at %s\n",
2469 step, gdb_signal_to_symbol_string (sig),
2470 tp->control.trap_expected,
2471 target_pid_to_str (inferior_ptid),
2472 paddress (gdbarch, pc));
2474 /* Normally, by the time we reach `resume', the breakpoints are either
2475 removed or inserted, as appropriate. The exception is if we're sitting
2476 at a permanent breakpoint; we need to step over it, but permanent
2477 breakpoints can't be removed. So we have to test for it here. */
2478 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2480 if (sig != GDB_SIGNAL_0)
2482 /* We have a signal to pass to the inferior. The resume
2483 may, or may not take us to the signal handler. If this
2484 is a step, we'll need to stop in the signal handler, if
2485 there's one, (if the target supports stepping into
2486 handlers), or in the next mainline instruction, if
2487 there's no handler. If this is a continue, we need to be
2488 sure to run the handler with all breakpoints inserted.
2489 In all cases, set a breakpoint at the current address
2490 (where the handler returns to), and once that breakpoint
2491 is hit, resume skipping the permanent breakpoint. If
2492 that breakpoint isn't hit, then we've stepped into the
2493 signal handler (or hit some other event). We'll delete
2494 the step-resume breakpoint then. */
2497 fprintf_unfiltered (gdb_stdlog,
2498 "infrun: resume: skipping permanent breakpoint, "
2499 "deliver signal first\n");
2501 clear_step_over_info ();
2502 tp->control.trap_expected = 0;
2504 if (tp->control.step_resume_breakpoint == NULL)
2506 /* Set a "high-priority" step-resume, as we don't want
2507 user breakpoints at PC to trigger (again) when this
2509 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2510 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2512 tp->step_after_step_resume_breakpoint = step;
2515 insert_breakpoints ();
2519 /* There's no signal to pass, we can go ahead and skip the
2520 permanent breakpoint manually. */
2522 fprintf_unfiltered (gdb_stdlog,
2523 "infrun: resume: skipping permanent breakpoint\n");
2524 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2525 /* Update pc to reflect the new address from which we will
2526 execute instructions. */
2527 pc = regcache_read_pc (regcache);
2531 /* We've already advanced the PC, so the stepping part
2532 is done. Now we need to arrange for a trap to be
2533 reported to handle_inferior_event. Set a breakpoint
2534 at the current PC, and run to it. Don't update
2535 prev_pc, because if we end in
2536 switch_back_to_stepped_thread, we want the "expected
2537 thread advanced also" branch to be taken. IOW, we
2538 don't want this thread to step further from PC
2540 gdb_assert (!step_over_info_valid_p ());
2541 insert_single_step_breakpoint (gdbarch, aspace, pc);
2542 insert_breakpoints ();
2544 resume_ptid = internal_resume_ptid (user_step);
2545 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2546 discard_cleanups (old_cleanups);
2553 /* If we have a breakpoint to step over, make sure to do a single
2554 step only. Same if we have software watchpoints. */
2555 if (tp->control.trap_expected || bpstat_should_step ())
2556 tp->control.may_range_step = 0;
2558 /* If enabled, step over breakpoints by executing a copy of the
2559 instruction at a different address.
2561 We can't use displaced stepping when we have a signal to deliver;
2562 the comments for displaced_step_prepare explain why. The
2563 comments in the handle_inferior event for dealing with 'random
2564 signals' explain what we do instead.
2566 We can't use displaced stepping when we are waiting for vfork_done
2567 event, displaced stepping breaks the vfork child similarly as single
2568 step software breakpoint. */
2569 if (tp->control.trap_expected
2570 && use_displaced_stepping (tp)
2571 && !step_over_info_valid_p ()
2572 && sig == GDB_SIGNAL_0
2573 && !current_inferior ()->waiting_for_vfork_done)
2575 int prepared = displaced_step_prepare (inferior_ptid);
2580 fprintf_unfiltered (gdb_stdlog,
2581 "Got placed in step-over queue\n");
2583 tp->control.trap_expected = 0;
2584 discard_cleanups (old_cleanups);
2587 else if (prepared < 0)
2589 /* Fallback to stepping over the breakpoint in-line. */
2591 if (target_is_non_stop_p ())
2592 stop_all_threads ();
2594 set_step_over_info (get_regcache_aspace (regcache),
2595 regcache_read_pc (regcache), 0, tp->global_num);
2597 step = maybe_software_singlestep (gdbarch, pc);
2599 insert_breakpoints ();
2601 else if (prepared > 0)
2603 struct displaced_step_inferior_state *displaced;
2605 /* Update pc to reflect the new address from which we will
2606 execute instructions due to displaced stepping. */
2607 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2609 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2610 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2611 displaced->step_closure);
2615 /* Do we need to do it the hard way, w/temp breakpoints? */
2617 step = maybe_software_singlestep (gdbarch, pc);
2619 /* Currently, our software single-step implementation leads to different
2620 results than hardware single-stepping in one situation: when stepping
2621 into delivering a signal which has an associated signal handler,
2622 hardware single-step will stop at the first instruction of the handler,
2623 while software single-step will simply skip execution of the handler.
2625 For now, this difference in behavior is accepted since there is no
2626 easy way to actually implement single-stepping into a signal handler
2627 without kernel support.
2629 However, there is one scenario where this difference leads to follow-on
2630 problems: if we're stepping off a breakpoint by removing all breakpoints
2631 and then single-stepping. In this case, the software single-step
2632 behavior means that even if there is a *breakpoint* in the signal
2633 handler, GDB still would not stop.
2635 Fortunately, we can at least fix this particular issue. We detect
2636 here the case where we are about to deliver a signal while software
2637 single-stepping with breakpoints removed. In this situation, we
2638 revert the decisions to remove all breakpoints and insert single-
2639 step breakpoints, and instead we install a step-resume breakpoint
2640 at the current address, deliver the signal without stepping, and
2641 once we arrive back at the step-resume breakpoint, actually step
2642 over the breakpoint we originally wanted to step over. */
2643 if (thread_has_single_step_breakpoints_set (tp)
2644 && sig != GDB_SIGNAL_0
2645 && step_over_info_valid_p ())
2647 /* If we have nested signals or a pending signal is delivered
2648 immediately after a handler returns, might might already have
2649 a step-resume breakpoint set on the earlier handler. We cannot
2650 set another step-resume breakpoint; just continue on until the
2651 original breakpoint is hit. */
2652 if (tp->control.step_resume_breakpoint == NULL)
2654 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2655 tp->step_after_step_resume_breakpoint = 1;
2658 delete_single_step_breakpoints (tp);
2660 clear_step_over_info ();
2661 tp->control.trap_expected = 0;
2663 insert_breakpoints ();
2666 /* If STEP is set, it's a request to use hardware stepping
2667 facilities. But in that case, we should never
2668 use singlestep breakpoint. */
2669 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2671 /* Decide the set of threads to ask the target to resume. */
2672 if (tp->control.trap_expected)
2674 /* We're allowing a thread to run past a breakpoint it has
2675 hit, either by single-stepping the thread with the breakpoint
2676 removed, or by displaced stepping, with the breakpoint inserted.
2677 In the former case, we need to single-step only this thread,
2678 and keep others stopped, as they can miss this breakpoint if
2679 allowed to run. That's not really a problem for displaced
2680 stepping, but, we still keep other threads stopped, in case
2681 another thread is also stopped for a breakpoint waiting for
2682 its turn in the displaced stepping queue. */
2683 resume_ptid = inferior_ptid;
2686 resume_ptid = internal_resume_ptid (user_step);
2688 if (execution_direction != EXEC_REVERSE
2689 && step && breakpoint_inserted_here_p (aspace, pc))
2691 /* There are two cases where we currently need to step a
2692 breakpoint instruction when we have a signal to deliver:
2694 - See handle_signal_stop where we handle random signals that
2695 could take out us out of the stepping range. Normally, in
2696 that case we end up continuing (instead of stepping) over the
2697 signal handler with a breakpoint at PC, but there are cases
2698 where we should _always_ single-step, even if we have a
2699 step-resume breakpoint, like when a software watchpoint is
2700 set. Assuming single-stepping and delivering a signal at the
2701 same time would takes us to the signal handler, then we could
2702 have removed the breakpoint at PC to step over it. However,
2703 some hardware step targets (like e.g., Mac OS) can't step
2704 into signal handlers, and for those, we need to leave the
2705 breakpoint at PC inserted, as otherwise if the handler
2706 recurses and executes PC again, it'll miss the breakpoint.
2707 So we leave the breakpoint inserted anyway, but we need to
2708 record that we tried to step a breakpoint instruction, so
2709 that adjust_pc_after_break doesn't end up confused.
2711 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2712 in one thread after another thread that was stepping had been
2713 momentarily paused for a step-over. When we re-resume the
2714 stepping thread, it may be resumed from that address with a
2715 breakpoint that hasn't trapped yet. Seen with
2716 gdb.threads/non-stop-fair-events.exp, on targets that don't
2717 do displaced stepping. */
2720 fprintf_unfiltered (gdb_stdlog,
2721 "infrun: resume: [%s] stepped breakpoint\n",
2722 target_pid_to_str (tp->ptid));
2724 tp->stepped_breakpoint = 1;
2726 /* Most targets can step a breakpoint instruction, thus
2727 executing it normally. But if this one cannot, just
2728 continue and we will hit it anyway. */
2729 if (gdbarch_cannot_step_breakpoint (gdbarch))
2734 && tp->control.trap_expected
2735 && use_displaced_stepping (tp)
2736 && !step_over_info_valid_p ())
2738 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2739 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2740 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2743 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2744 paddress (resume_gdbarch, actual_pc));
2745 read_memory (actual_pc, buf, sizeof (buf));
2746 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2749 if (tp->control.may_range_step)
2751 /* If we're resuming a thread with the PC out of the step
2752 range, then we're doing some nested/finer run control
2753 operation, like stepping the thread out of the dynamic
2754 linker or the displaced stepping scratch pad. We
2755 shouldn't have allowed a range step then. */
2756 gdb_assert (pc_in_thread_step_range (pc, tp));
2759 do_target_resume (resume_ptid, step, sig);
2761 discard_cleanups (old_cleanups);
2768 /* Counter that tracks number of user visible stops. This can be used
2769 to tell whether a command has proceeded the inferior past the
2770 current location. This allows e.g., inferior function calls in
2771 breakpoint commands to not interrupt the command list. When the
2772 call finishes successfully, the inferior is standing at the same
2773 breakpoint as if nothing happened (and so we don't call
2775 static ULONGEST current_stop_id;
2782 return current_stop_id;
2785 /* Called when we report a user visible stop. */
2793 /* Clear out all variables saying what to do when inferior is continued.
2794 First do this, then set the ones you want, then call `proceed'. */
2797 clear_proceed_status_thread (struct thread_info *tp)
2800 fprintf_unfiltered (gdb_stdlog,
2801 "infrun: clear_proceed_status_thread (%s)\n",
2802 target_pid_to_str (tp->ptid));
2804 /* If we're starting a new sequence, then the previous finished
2805 single-step is no longer relevant. */
2806 if (tp->suspend.waitstatus_pending_p)
2808 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2811 fprintf_unfiltered (gdb_stdlog,
2812 "infrun: clear_proceed_status: pending "
2813 "event of %s was a finished step. "
2815 target_pid_to_str (tp->ptid));
2817 tp->suspend.waitstatus_pending_p = 0;
2818 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2820 else if (debug_infrun)
2823 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2825 fprintf_unfiltered (gdb_stdlog,
2826 "infrun: clear_proceed_status_thread: thread %s "
2827 "has pending wait status %s "
2828 "(currently_stepping=%d).\n",
2829 target_pid_to_str (tp->ptid), statstr.c_str (),
2830 currently_stepping (tp));
2834 /* If this signal should not be seen by program, give it zero.
2835 Used for debugging signals. */
2836 if (!signal_pass_state (tp->suspend.stop_signal))
2837 tp->suspend.stop_signal = GDB_SIGNAL_0;
2839 thread_fsm_delete (tp->thread_fsm);
2840 tp->thread_fsm = NULL;
2842 tp->control.trap_expected = 0;
2843 tp->control.step_range_start = 0;
2844 tp->control.step_range_end = 0;
2845 tp->control.may_range_step = 0;
2846 tp->control.step_frame_id = null_frame_id;
2847 tp->control.step_stack_frame_id = null_frame_id;
2848 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2849 tp->control.step_start_function = NULL;
2850 tp->stop_requested = 0;
2852 tp->control.stop_step = 0;
2854 tp->control.proceed_to_finish = 0;
2856 tp->control.stepping_command = 0;
2858 /* Discard any remaining commands or status from previous stop. */
2859 bpstat_clear (&tp->control.stop_bpstat);
2863 clear_proceed_status (int step)
2865 /* With scheduler-locking replay, stop replaying other threads if we're
2866 not replaying the user-visible resume ptid.
2868 This is a convenience feature to not require the user to explicitly
2869 stop replaying the other threads. We're assuming that the user's
2870 intent is to resume tracing the recorded process. */
2871 if (!non_stop && scheduler_mode == schedlock_replay
2872 && target_record_is_replaying (minus_one_ptid)
2873 && !target_record_will_replay (user_visible_resume_ptid (step),
2874 execution_direction))
2875 target_record_stop_replaying ();
2879 struct thread_info *tp;
2882 resume_ptid = user_visible_resume_ptid (step);
2884 /* In all-stop mode, delete the per-thread status of all threads
2885 we're about to resume, implicitly and explicitly. */
2886 ALL_NON_EXITED_THREADS (tp)
2888 if (!ptid_match (tp->ptid, resume_ptid))
2890 clear_proceed_status_thread (tp);
2894 if (!ptid_equal (inferior_ptid, null_ptid))
2896 struct inferior *inferior;
2900 /* If in non-stop mode, only delete the per-thread status of
2901 the current thread. */
2902 clear_proceed_status_thread (inferior_thread ());
2905 inferior = current_inferior ();
2906 inferior->control.stop_soon = NO_STOP_QUIETLY;
2909 observer_notify_about_to_proceed ();
2912 /* Returns true if TP is still stopped at a breakpoint that needs
2913 stepping-over in order to make progress. If the breakpoint is gone
2914 meanwhile, we can skip the whole step-over dance. */
2917 thread_still_needs_step_over_bp (struct thread_info *tp)
2919 if (tp->stepping_over_breakpoint)
2921 struct regcache *regcache = get_thread_regcache (tp->ptid);
2923 if (breakpoint_here_p (get_regcache_aspace (regcache),
2924 regcache_read_pc (regcache))
2925 == ordinary_breakpoint_here)
2928 tp->stepping_over_breakpoint = 0;
2934 /* Check whether thread TP still needs to start a step-over in order
2935 to make progress when resumed. Returns an bitwise or of enum
2936 step_over_what bits, indicating what needs to be stepped over. */
2938 static step_over_what
2939 thread_still_needs_step_over (struct thread_info *tp)
2941 step_over_what what = 0;
2943 if (thread_still_needs_step_over_bp (tp))
2944 what |= STEP_OVER_BREAKPOINT;
2946 if (tp->stepping_over_watchpoint
2947 && !target_have_steppable_watchpoint)
2948 what |= STEP_OVER_WATCHPOINT;
2953 /* Returns true if scheduler locking applies. STEP indicates whether
2954 we're about to do a step/next-like command to a thread. */
2957 schedlock_applies (struct thread_info *tp)
2959 return (scheduler_mode == schedlock_on
2960 || (scheduler_mode == schedlock_step
2961 && tp->control.stepping_command)
2962 || (scheduler_mode == schedlock_replay
2963 && target_record_will_replay (minus_one_ptid,
2964 execution_direction)));
2967 /* Basic routine for continuing the program in various fashions.
2969 ADDR is the address to resume at, or -1 for resume where stopped.
2970 SIGGNAL is the signal to give it, or 0 for none,
2971 or -1 for act according to how it stopped.
2972 STEP is nonzero if should trap after one instruction.
2973 -1 means return after that and print nothing.
2974 You should probably set various step_... variables
2975 before calling here, if you are stepping.
2977 You should call clear_proceed_status before calling proceed. */
2980 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2982 struct regcache *regcache;
2983 struct gdbarch *gdbarch;
2984 struct thread_info *tp;
2986 struct address_space *aspace;
2988 struct execution_control_state ecss;
2989 struct execution_control_state *ecs = &ecss;
2990 struct cleanup *old_chain;
2991 struct cleanup *defer_resume_cleanup;
2994 /* If we're stopped at a fork/vfork, follow the branch set by the
2995 "set follow-fork-mode" command; otherwise, we'll just proceed
2996 resuming the current thread. */
2997 if (!follow_fork ())
2999 /* The target for some reason decided not to resume. */
3001 if (target_can_async_p ())
3002 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3006 /* We'll update this if & when we switch to a new thread. */
3007 previous_inferior_ptid = inferior_ptid;
3009 regcache = get_current_regcache ();
3010 gdbarch = get_regcache_arch (regcache);
3011 aspace = get_regcache_aspace (regcache);
3012 pc = regcache_read_pc (regcache);
3013 tp = inferior_thread ();
3015 /* Fill in with reasonable starting values. */
3016 init_thread_stepping_state (tp);
3018 gdb_assert (!thread_is_in_step_over_chain (tp));
3020 if (addr == (CORE_ADDR) -1)
3023 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
3024 && execution_direction != EXEC_REVERSE)
3025 /* There is a breakpoint at the address we will resume at,
3026 step one instruction before inserting breakpoints so that
3027 we do not stop right away (and report a second hit at this
3030 Note, we don't do this in reverse, because we won't
3031 actually be executing the breakpoint insn anyway.
3032 We'll be (un-)executing the previous instruction. */
3033 tp->stepping_over_breakpoint = 1;
3034 else if (gdbarch_single_step_through_delay_p (gdbarch)
3035 && gdbarch_single_step_through_delay (gdbarch,
3036 get_current_frame ()))
3037 /* We stepped onto an instruction that needs to be stepped
3038 again before re-inserting the breakpoint, do so. */
3039 tp->stepping_over_breakpoint = 1;
3043 regcache_write_pc (regcache, addr);
3046 if (siggnal != GDB_SIGNAL_DEFAULT)
3047 tp->suspend.stop_signal = siggnal;
3049 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3051 /* If an exception is thrown from this point on, make sure to
3052 propagate GDB's knowledge of the executing state to the
3053 frontend/user running state. */
3054 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
3056 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3057 threads (e.g., we might need to set threads stepping over
3058 breakpoints first), from the user/frontend's point of view, all
3059 threads in RESUME_PTID are now running. Unless we're calling an
3060 inferior function, as in that case we pretend the inferior
3061 doesn't run at all. */
3062 if (!tp->control.in_infcall)
3063 set_running (resume_ptid, 1);
3066 fprintf_unfiltered (gdb_stdlog,
3067 "infrun: proceed (addr=%s, signal=%s)\n",
3068 paddress (gdbarch, addr),
3069 gdb_signal_to_symbol_string (siggnal));
3071 annotate_starting ();
3073 /* Make sure that output from GDB appears before output from the
3075 gdb_flush (gdb_stdout);
3077 /* In a multi-threaded task we may select another thread and
3078 then continue or step.
3080 But if a thread that we're resuming had stopped at a breakpoint,
3081 it will immediately cause another breakpoint stop without any
3082 execution (i.e. it will report a breakpoint hit incorrectly). So
3083 we must step over it first.
3085 Look for threads other than the current (TP) that reported a
3086 breakpoint hit and haven't been resumed yet since. */
3088 /* If scheduler locking applies, we can avoid iterating over all
3090 if (!non_stop && !schedlock_applies (tp))
3092 struct thread_info *current = tp;
3094 ALL_NON_EXITED_THREADS (tp)
3096 /* Ignore the current thread here. It's handled
3101 /* Ignore threads of processes we're not resuming. */
3102 if (!ptid_match (tp->ptid, resume_ptid))
3105 if (!thread_still_needs_step_over (tp))
3108 gdb_assert (!thread_is_in_step_over_chain (tp));
3111 fprintf_unfiltered (gdb_stdlog,
3112 "infrun: need to step-over [%s] first\n",
3113 target_pid_to_str (tp->ptid));
3115 thread_step_over_chain_enqueue (tp);
3121 /* Enqueue the current thread last, so that we move all other
3122 threads over their breakpoints first. */
3123 if (tp->stepping_over_breakpoint)
3124 thread_step_over_chain_enqueue (tp);
3126 /* If the thread isn't started, we'll still need to set its prev_pc,
3127 so that switch_back_to_stepped_thread knows the thread hasn't
3128 advanced. Must do this before resuming any thread, as in
3129 all-stop/remote, once we resume we can't send any other packet
3130 until the target stops again. */
3131 tp->prev_pc = regcache_read_pc (regcache);
3133 defer_resume_cleanup = make_cleanup_defer_target_commit_resume ();
3135 started = start_step_over ();
3137 if (step_over_info_valid_p ())
3139 /* Either this thread started a new in-line step over, or some
3140 other thread was already doing one. In either case, don't
3141 resume anything else until the step-over is finished. */
3143 else if (started && !target_is_non_stop_p ())
3145 /* A new displaced stepping sequence was started. In all-stop,
3146 we can't talk to the target anymore until it next stops. */
3148 else if (!non_stop && target_is_non_stop_p ())
3150 /* In all-stop, but the target is always in non-stop mode.
3151 Start all other threads that are implicitly resumed too. */
3152 ALL_NON_EXITED_THREADS (tp)
3154 /* Ignore threads of processes we're not resuming. */
3155 if (!ptid_match (tp->ptid, resume_ptid))
3161 fprintf_unfiltered (gdb_stdlog,
3162 "infrun: proceed: [%s] resumed\n",
3163 target_pid_to_str (tp->ptid));
3164 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3168 if (thread_is_in_step_over_chain (tp))
3171 fprintf_unfiltered (gdb_stdlog,
3172 "infrun: proceed: [%s] needs step-over\n",
3173 target_pid_to_str (tp->ptid));
3178 fprintf_unfiltered (gdb_stdlog,
3179 "infrun: proceed: resuming %s\n",
3180 target_pid_to_str (tp->ptid));
3182 reset_ecs (ecs, tp);
3183 switch_to_thread (tp->ptid);
3184 keep_going_pass_signal (ecs);
3185 if (!ecs->wait_some_more)
3186 error (_("Command aborted."));
3189 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3191 /* The thread wasn't started, and isn't queued, run it now. */
3192 reset_ecs (ecs, tp);
3193 switch_to_thread (tp->ptid);
3194 keep_going_pass_signal (ecs);
3195 if (!ecs->wait_some_more)
3196 error (_("Command aborted."));
3199 do_cleanups (defer_resume_cleanup);
3200 target_commit_resume ();
3202 discard_cleanups (old_chain);
3204 /* Tell the event loop to wait for it to stop. If the target
3205 supports asynchronous execution, it'll do this from within
3207 if (!target_can_async_p ())
3208 mark_async_event_handler (infrun_async_inferior_event_token);
3212 /* Start remote-debugging of a machine over a serial link. */
3215 start_remote (int from_tty)
3217 struct inferior *inferior;
3219 inferior = current_inferior ();
3220 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3222 /* Always go on waiting for the target, regardless of the mode. */
3223 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3224 indicate to wait_for_inferior that a target should timeout if
3225 nothing is returned (instead of just blocking). Because of this,
3226 targets expecting an immediate response need to, internally, set
3227 things up so that the target_wait() is forced to eventually
3229 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3230 differentiate to its caller what the state of the target is after
3231 the initial open has been performed. Here we're assuming that
3232 the target has stopped. It should be possible to eventually have
3233 target_open() return to the caller an indication that the target
3234 is currently running and GDB state should be set to the same as
3235 for an async run. */
3236 wait_for_inferior ();
3238 /* Now that the inferior has stopped, do any bookkeeping like
3239 loading shared libraries. We want to do this before normal_stop,
3240 so that the displayed frame is up to date. */
3241 post_create_inferior (¤t_target, from_tty);
3246 /* Initialize static vars when a new inferior begins. */
3249 init_wait_for_inferior (void)
3251 /* These are meaningless until the first time through wait_for_inferior. */
3253 breakpoint_init_inferior (inf_starting);
3255 clear_proceed_status (0);
3257 target_last_wait_ptid = minus_one_ptid;
3259 previous_inferior_ptid = inferior_ptid;
3261 /* Discard any skipped inlined frames. */
3262 clear_inline_frame_state (minus_one_ptid);
3267 static void handle_inferior_event (struct execution_control_state *ecs);
3269 static void handle_step_into_function (struct gdbarch *gdbarch,
3270 struct execution_control_state *ecs);
3271 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3272 struct execution_control_state *ecs);
3273 static void handle_signal_stop (struct execution_control_state *ecs);
3274 static void check_exception_resume (struct execution_control_state *,
3275 struct frame_info *);
3277 static void end_stepping_range (struct execution_control_state *ecs);
3278 static void stop_waiting (struct execution_control_state *ecs);
3279 static void keep_going (struct execution_control_state *ecs);
3280 static void process_event_stop_test (struct execution_control_state *ecs);
3281 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3283 /* This function is attached as a "thread_stop_requested" observer.
3284 Cleanup local state that assumed the PTID was to be resumed, and
3285 report the stop to the frontend. */
3288 infrun_thread_stop_requested (ptid_t ptid)
3290 struct thread_info *tp;
3292 /* PTID was requested to stop. If the thread was already stopped,
3293 but the user/frontend doesn't know about that yet (e.g., the
3294 thread had been temporarily paused for some step-over), set up
3295 for reporting the stop now. */
3296 ALL_NON_EXITED_THREADS (tp)
3297 if (ptid_match (tp->ptid, ptid))
3299 if (tp->state != THREAD_RUNNING)
3304 /* Remove matching threads from the step-over queue, so
3305 start_step_over doesn't try to resume them
3307 if (thread_is_in_step_over_chain (tp))
3308 thread_step_over_chain_remove (tp);
3310 /* If the thread is stopped, but the user/frontend doesn't
3311 know about that yet, queue a pending event, as if the
3312 thread had just stopped now. Unless the thread already had
3314 if (!tp->suspend.waitstatus_pending_p)
3316 tp->suspend.waitstatus_pending_p = 1;
3317 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3318 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3321 /* Clear the inline-frame state, since we're re-processing the
3323 clear_inline_frame_state (tp->ptid);
3325 /* If this thread was paused because some other thread was
3326 doing an inline-step over, let that finish first. Once
3327 that happens, we'll restart all threads and consume pending
3328 stop events then. */
3329 if (step_over_info_valid_p ())
3332 /* Otherwise we can process the (new) pending event now. Set
3333 it so this pending event is considered by
3340 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3342 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3343 nullify_last_target_wait_ptid ();
3346 /* Delete the step resume, single-step and longjmp/exception resume
3347 breakpoints of TP. */
3350 delete_thread_infrun_breakpoints (struct thread_info *tp)
3352 delete_step_resume_breakpoint (tp);
3353 delete_exception_resume_breakpoint (tp);
3354 delete_single_step_breakpoints (tp);
3357 /* If the target still has execution, call FUNC for each thread that
3358 just stopped. In all-stop, that's all the non-exited threads; in
3359 non-stop, that's the current thread, only. */
3361 typedef void (*for_each_just_stopped_thread_callback_func)
3362 (struct thread_info *tp);
3365 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3367 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3370 if (target_is_non_stop_p ())
3372 /* If in non-stop mode, only the current thread stopped. */
3373 func (inferior_thread ());
3377 struct thread_info *tp;
3379 /* In all-stop mode, all threads have stopped. */
3380 ALL_NON_EXITED_THREADS (tp)
3387 /* Delete the step resume and longjmp/exception resume breakpoints of
3388 the threads that just stopped. */
3391 delete_just_stopped_threads_infrun_breakpoints (void)
3393 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3396 /* Delete the single-step breakpoints of the threads that just
3400 delete_just_stopped_threads_single_step_breakpoints (void)
3402 for_each_just_stopped_thread (delete_single_step_breakpoints);
3405 /* A cleanup wrapper. */
3408 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3410 delete_just_stopped_threads_infrun_breakpoints ();
3416 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3417 const struct target_waitstatus *ws)
3419 std::string status_string = target_waitstatus_to_string (ws);
3422 /* The text is split over several lines because it was getting too long.
3423 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3424 output as a unit; we want only one timestamp printed if debug_timestamp
3427 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3428 ptid_get_pid (waiton_ptid),
3429 ptid_get_lwp (waiton_ptid),
3430 ptid_get_tid (waiton_ptid));
3431 if (ptid_get_pid (waiton_ptid) != -1)
3432 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3433 stb.printf (", status) =\n");
3434 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3435 ptid_get_pid (result_ptid),
3436 ptid_get_lwp (result_ptid),
3437 ptid_get_tid (result_ptid),
3438 target_pid_to_str (result_ptid));
3439 stb.printf ("infrun: %s\n", status_string.c_str ());
3441 /* This uses %s in part to handle %'s in the text, but also to avoid
3442 a gcc error: the format attribute requires a string literal. */
3443 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3446 /* Select a thread at random, out of those which are resumed and have
3449 static struct thread_info *
3450 random_pending_event_thread (ptid_t waiton_ptid)
3452 struct thread_info *event_tp;
3454 int random_selector;
3456 /* First see how many events we have. Count only resumed threads
3457 that have an event pending. */
3458 ALL_NON_EXITED_THREADS (event_tp)
3459 if (ptid_match (event_tp->ptid, waiton_ptid)
3460 && event_tp->resumed
3461 && event_tp->suspend.waitstatus_pending_p)
3464 if (num_events == 0)
3467 /* Now randomly pick a thread out of those that have had events. */
3468 random_selector = (int)
3469 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3471 if (debug_infrun && num_events > 1)
3472 fprintf_unfiltered (gdb_stdlog,
3473 "infrun: Found %d events, selecting #%d\n",
3474 num_events, random_selector);
3476 /* Select the Nth thread that has had an event. */
3477 ALL_NON_EXITED_THREADS (event_tp)
3478 if (ptid_match (event_tp->ptid, waiton_ptid)
3479 && event_tp->resumed
3480 && event_tp->suspend.waitstatus_pending_p)
3481 if (random_selector-- == 0)
3487 /* Wrapper for target_wait that first checks whether threads have
3488 pending statuses to report before actually asking the target for
3492 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3495 struct thread_info *tp;
3497 /* First check if there is a resumed thread with a wait status
3499 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3501 tp = random_pending_event_thread (ptid);
3506 fprintf_unfiltered (gdb_stdlog,
3507 "infrun: Waiting for specific thread %s.\n",
3508 target_pid_to_str (ptid));
3510 /* We have a specific thread to check. */
3511 tp = find_thread_ptid (ptid);
3512 gdb_assert (tp != NULL);
3513 if (!tp->suspend.waitstatus_pending_p)
3518 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3519 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3521 struct regcache *regcache = get_thread_regcache (tp->ptid);
3522 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3526 pc = regcache_read_pc (regcache);
3528 if (pc != tp->suspend.stop_pc)
3531 fprintf_unfiltered (gdb_stdlog,
3532 "infrun: PC of %s changed. was=%s, now=%s\n",
3533 target_pid_to_str (tp->ptid),
3534 paddress (gdbarch, tp->prev_pc),
3535 paddress (gdbarch, pc));
3538 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3541 fprintf_unfiltered (gdb_stdlog,
3542 "infrun: previous breakpoint of %s, at %s gone\n",
3543 target_pid_to_str (tp->ptid),
3544 paddress (gdbarch, pc));
3552 fprintf_unfiltered (gdb_stdlog,
3553 "infrun: pending event of %s cancelled.\n",
3554 target_pid_to_str (tp->ptid));
3556 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3557 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3566 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3568 fprintf_unfiltered (gdb_stdlog,
3569 "infrun: Using pending wait status %s for %s.\n",
3571 target_pid_to_str (tp->ptid));
3574 /* Now that we've selected our final event LWP, un-adjust its PC
3575 if it was a software breakpoint (and the target doesn't
3576 always adjust the PC itself). */
3577 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3578 && !target_supports_stopped_by_sw_breakpoint ())
3580 struct regcache *regcache;
3581 struct gdbarch *gdbarch;
3584 regcache = get_thread_regcache (tp->ptid);
3585 gdbarch = get_regcache_arch (regcache);
3587 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3592 pc = regcache_read_pc (regcache);
3593 regcache_write_pc (regcache, pc + decr_pc);
3597 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3598 *status = tp->suspend.waitstatus;
3599 tp->suspend.waitstatus_pending_p = 0;
3601 /* Wake up the event loop again, until all pending events are
3603 if (target_is_async_p ())
3604 mark_async_event_handler (infrun_async_inferior_event_token);
3608 /* But if we don't find one, we'll have to wait. */
3610 if (deprecated_target_wait_hook)
3611 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3613 event_ptid = target_wait (ptid, status, options);
3618 /* Prepare and stabilize the inferior for detaching it. E.g.,
3619 detaching while a thread is displaced stepping is a recipe for
3620 crashing it, as nothing would readjust the PC out of the scratch
3624 prepare_for_detach (void)
3626 struct inferior *inf = current_inferior ();
3627 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3628 struct displaced_step_inferior_state *displaced;
3630 displaced = get_displaced_stepping_state (inf->pid);
3632 /* Is any thread of this process displaced stepping? If not,
3633 there's nothing else to do. */
3634 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3638 fprintf_unfiltered (gdb_stdlog,
3639 "displaced-stepping in-process while detaching");
3641 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3643 while (!ptid_equal (displaced->step_ptid, null_ptid))
3645 struct cleanup *old_chain_2;
3646 struct execution_control_state ecss;
3647 struct execution_control_state *ecs;
3650 memset (ecs, 0, sizeof (*ecs));
3652 overlay_cache_invalid = 1;
3653 /* Flush target cache before starting to handle each event.
3654 Target was running and cache could be stale. This is just a
3655 heuristic. Running threads may modify target memory, but we
3656 don't get any event. */
3657 target_dcache_invalidate ();
3659 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3662 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3664 /* If an error happens while handling the event, propagate GDB's
3665 knowledge of the executing state to the frontend/user running
3667 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3670 /* Now figure out what to do with the result of the result. */
3671 handle_inferior_event (ecs);
3673 /* No error, don't finish the state yet. */
3674 discard_cleanups (old_chain_2);
3676 /* Breakpoints and watchpoints are not installed on the target
3677 at this point, and signals are passed directly to the
3678 inferior, so this must mean the process is gone. */
3679 if (!ecs->wait_some_more)
3681 restore_detaching.release ();
3682 error (_("Program exited while detaching"));
3686 restore_detaching.release ();
3689 /* Wait for control to return from inferior to debugger.
3691 If inferior gets a signal, we may decide to start it up again
3692 instead of returning. That is why there is a loop in this function.
3693 When this function actually returns it means the inferior
3694 should be left stopped and GDB should read more commands. */
3697 wait_for_inferior (void)
3699 struct cleanup *old_cleanups;
3700 struct cleanup *thread_state_chain;
3704 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3707 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3710 /* If an error happens while handling the event, propagate GDB's
3711 knowledge of the executing state to the frontend/user running
3713 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3717 struct execution_control_state ecss;
3718 struct execution_control_state *ecs = &ecss;
3719 ptid_t waiton_ptid = minus_one_ptid;
3721 memset (ecs, 0, sizeof (*ecs));
3723 overlay_cache_invalid = 1;
3725 /* Flush target cache before starting to handle each event.
3726 Target was running and cache could be stale. This is just a
3727 heuristic. Running threads may modify target memory, but we
3728 don't get any event. */
3729 target_dcache_invalidate ();
3731 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3734 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3736 /* Now figure out what to do with the result of the result. */
3737 handle_inferior_event (ecs);
3739 if (!ecs->wait_some_more)
3743 /* No error, don't finish the state yet. */
3744 discard_cleanups (thread_state_chain);
3746 do_cleanups (old_cleanups);
3749 /* Cleanup that reinstalls the readline callback handler, if the
3750 target is running in the background. If while handling the target
3751 event something triggered a secondary prompt, like e.g., a
3752 pagination prompt, we'll have removed the callback handler (see
3753 gdb_readline_wrapper_line). Need to do this as we go back to the
3754 event loop, ready to process further input. Note this has no
3755 effect if the handler hasn't actually been removed, because calling
3756 rl_callback_handler_install resets the line buffer, thus losing
3760 reinstall_readline_callback_handler_cleanup (void *arg)
3762 struct ui *ui = current_ui;
3766 /* We're not going back to the top level event loop yet. Don't
3767 install the readline callback, as it'd prep the terminal,
3768 readline-style (raw, noecho) (e.g., --batch). We'll install
3769 it the next time the prompt is displayed, when we're ready
3774 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3775 gdb_rl_callback_handler_reinstall ();
3778 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3779 that's just the event thread. In all-stop, that's all threads. */
3782 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3784 struct thread_info *thr = ecs->event_thread;
3786 if (thr != NULL && thr->thread_fsm != NULL)
3787 thread_fsm_clean_up (thr->thread_fsm, thr);
3791 ALL_NON_EXITED_THREADS (thr)
3793 if (thr->thread_fsm == NULL)
3795 if (thr == ecs->event_thread)
3798 switch_to_thread (thr->ptid);
3799 thread_fsm_clean_up (thr->thread_fsm, thr);
3802 if (ecs->event_thread != NULL)
3803 switch_to_thread (ecs->event_thread->ptid);
3807 /* Helper for all_uis_check_sync_execution_done that works on the
3811 check_curr_ui_sync_execution_done (void)
3813 struct ui *ui = current_ui;
3815 if (ui->prompt_state == PROMPT_NEEDED
3817 && !gdb_in_secondary_prompt_p (ui))
3819 target_terminal_ours ();
3820 observer_notify_sync_execution_done ();
3821 ui_register_input_event_handler (ui);
3828 all_uis_check_sync_execution_done (void)
3830 SWITCH_THRU_ALL_UIS ()
3832 check_curr_ui_sync_execution_done ();
3839 all_uis_on_sync_execution_starting (void)
3841 SWITCH_THRU_ALL_UIS ()
3843 if (current_ui->prompt_state == PROMPT_NEEDED)
3844 async_disable_stdin ();
3848 /* Asynchronous version of wait_for_inferior. It is called by the
3849 event loop whenever a change of state is detected on the file
3850 descriptor corresponding to the target. It can be called more than
3851 once to complete a single execution command. In such cases we need
3852 to keep the state in a global variable ECSS. If it is the last time
3853 that this function is called for a single execution command, then
3854 report to the user that the inferior has stopped, and do the
3855 necessary cleanups. */
3858 fetch_inferior_event (void *client_data)
3860 struct execution_control_state ecss;
3861 struct execution_control_state *ecs = &ecss;
3862 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3863 struct cleanup *ts_old_chain;
3865 ptid_t waiton_ptid = minus_one_ptid;
3867 memset (ecs, 0, sizeof (*ecs));
3869 /* Events are always processed with the main UI as current UI. This
3870 way, warnings, debug output, etc. are always consistently sent to
3871 the main console. */
3872 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3874 /* End up with readline processing input, if necessary. */
3875 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3877 /* We're handling a live event, so make sure we're doing live
3878 debugging. If we're looking at traceframes while the target is
3879 running, we're going to need to get back to that mode after
3880 handling the event. */
3883 make_cleanup_restore_current_traceframe ();
3884 set_current_traceframe (-1);
3887 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3890 /* In non-stop mode, the user/frontend should not notice a thread
3891 switch due to internal events. Make sure we reverse to the
3892 user selected thread and frame after handling the event and
3893 running any breakpoint commands. */
3894 maybe_restore_thread.emplace ();
3896 overlay_cache_invalid = 1;
3897 /* Flush target cache before starting to handle each event. Target
3898 was running and cache could be stale. This is just a heuristic.
3899 Running threads may modify target memory, but we don't get any
3901 target_dcache_invalidate ();
3903 scoped_restore save_exec_dir
3904 = make_scoped_restore (&execution_direction, target_execution_direction ());
3906 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3907 target_can_async_p () ? TARGET_WNOHANG : 0);
3910 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3912 /* If an error happens while handling the event, propagate GDB's
3913 knowledge of the executing state to the frontend/user running
3915 if (!target_is_non_stop_p ())
3916 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3918 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3920 /* Get executed before make_cleanup_restore_current_thread above to apply
3921 still for the thread which has thrown the exception. */
3922 make_bpstat_clear_actions_cleanup ();
3924 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3926 /* Now figure out what to do with the result of the result. */
3927 handle_inferior_event (ecs);
3929 if (!ecs->wait_some_more)
3931 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3932 int should_stop = 1;
3933 struct thread_info *thr = ecs->event_thread;
3934 int should_notify_stop = 1;
3936 delete_just_stopped_threads_infrun_breakpoints ();
3940 struct thread_fsm *thread_fsm = thr->thread_fsm;
3942 if (thread_fsm != NULL)
3943 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3952 clean_up_just_stopped_threads_fsms (ecs);
3954 if (thr != NULL && thr->thread_fsm != NULL)
3957 = thread_fsm_should_notify_stop (thr->thread_fsm);
3960 if (should_notify_stop)
3964 /* We may not find an inferior if this was a process exit. */
3965 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3966 proceeded = normal_stop ();
3970 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3977 /* No error, don't finish the thread states yet. */
3978 discard_cleanups (ts_old_chain);
3980 /* Revert thread and frame. */
3981 do_cleanups (old_chain);
3983 /* If a UI was in sync execution mode, and now isn't, restore its
3984 prompt (a synchronous execution command has finished, and we're
3985 ready for input). */
3986 all_uis_check_sync_execution_done ();
3989 && exec_done_display_p
3990 && (ptid_equal (inferior_ptid, null_ptid)
3991 || !is_running (inferior_ptid)))
3992 printf_unfiltered (_("completed.\n"));
3995 /* Record the frame and location we're currently stepping through. */
3997 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3999 struct thread_info *tp = inferior_thread ();
4001 tp->control.step_frame_id = get_frame_id (frame);
4002 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
4004 tp->current_symtab = sal.symtab;
4005 tp->current_line = sal.line;
4008 /* Clear context switchable stepping state. */
4011 init_thread_stepping_state (struct thread_info *tss)
4013 tss->stepped_breakpoint = 0;
4014 tss->stepping_over_breakpoint = 0;
4015 tss->stepping_over_watchpoint = 0;
4016 tss->step_after_step_resume_breakpoint = 0;
4019 /* Set the cached copy of the last ptid/waitstatus. */
4022 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4024 target_last_wait_ptid = ptid;
4025 target_last_waitstatus = status;
4028 /* Return the cached copy of the last pid/waitstatus returned by
4029 target_wait()/deprecated_target_wait_hook(). The data is actually
4030 cached by handle_inferior_event(), which gets called immediately
4031 after target_wait()/deprecated_target_wait_hook(). */
4034 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4036 *ptidp = target_last_wait_ptid;
4037 *status = target_last_waitstatus;
4041 nullify_last_target_wait_ptid (void)
4043 target_last_wait_ptid = minus_one_ptid;
4046 /* Switch thread contexts. */
4049 context_switch (ptid_t ptid)
4051 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4053 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4054 target_pid_to_str (inferior_ptid));
4055 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4056 target_pid_to_str (ptid));
4059 switch_to_thread (ptid);
4062 /* If the target can't tell whether we've hit breakpoints
4063 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4064 check whether that could have been caused by a breakpoint. If so,
4065 adjust the PC, per gdbarch_decr_pc_after_break. */
4068 adjust_pc_after_break (struct thread_info *thread,
4069 struct target_waitstatus *ws)
4071 struct regcache *regcache;
4072 struct gdbarch *gdbarch;
4073 struct address_space *aspace;
4074 CORE_ADDR breakpoint_pc, decr_pc;
4076 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4077 we aren't, just return.
4079 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4080 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4081 implemented by software breakpoints should be handled through the normal
4084 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4085 different signals (SIGILL or SIGEMT for instance), but it is less
4086 clear where the PC is pointing afterwards. It may not match
4087 gdbarch_decr_pc_after_break. I don't know any specific target that
4088 generates these signals at breakpoints (the code has been in GDB since at
4089 least 1992) so I can not guess how to handle them here.
4091 In earlier versions of GDB, a target with
4092 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4093 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4094 target with both of these set in GDB history, and it seems unlikely to be
4095 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4097 if (ws->kind != TARGET_WAITKIND_STOPPED)
4100 if (ws->value.sig != GDB_SIGNAL_TRAP)
4103 /* In reverse execution, when a breakpoint is hit, the instruction
4104 under it has already been de-executed. The reported PC always
4105 points at the breakpoint address, so adjusting it further would
4106 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4109 B1 0x08000000 : INSN1
4110 B2 0x08000001 : INSN2
4112 PC -> 0x08000003 : INSN4
4114 Say you're stopped at 0x08000003 as above. Reverse continuing
4115 from that point should hit B2 as below. Reading the PC when the
4116 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4117 been de-executed already.
4119 B1 0x08000000 : INSN1
4120 B2 PC -> 0x08000001 : INSN2
4124 We can't apply the same logic as for forward execution, because
4125 we would wrongly adjust the PC to 0x08000000, since there's a
4126 breakpoint at PC - 1. We'd then report a hit on B1, although
4127 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4129 if (execution_direction == EXEC_REVERSE)
4132 /* If the target can tell whether the thread hit a SW breakpoint,
4133 trust it. Targets that can tell also adjust the PC
4135 if (target_supports_stopped_by_sw_breakpoint ())
4138 /* Note that relying on whether a breakpoint is planted in memory to
4139 determine this can fail. E.g,. the breakpoint could have been
4140 removed since. Or the thread could have been told to step an
4141 instruction the size of a breakpoint instruction, and only
4142 _after_ was a breakpoint inserted at its address. */
4144 /* If this target does not decrement the PC after breakpoints, then
4145 we have nothing to do. */
4146 regcache = get_thread_regcache (thread->ptid);
4147 gdbarch = get_regcache_arch (regcache);
4149 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4153 aspace = get_regcache_aspace (regcache);
4155 /* Find the location where (if we've hit a breakpoint) the
4156 breakpoint would be. */
4157 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4159 /* If the target can't tell whether a software breakpoint triggered,
4160 fallback to figuring it out based on breakpoints we think were
4161 inserted in the target, and on whether the thread was stepped or
4164 /* Check whether there actually is a software breakpoint inserted at
4167 If in non-stop mode, a race condition is possible where we've
4168 removed a breakpoint, but stop events for that breakpoint were
4169 already queued and arrive later. To suppress those spurious
4170 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4171 and retire them after a number of stop events are reported. Note
4172 this is an heuristic and can thus get confused. The real fix is
4173 to get the "stopped by SW BP and needs adjustment" info out of
4174 the target/kernel (and thus never reach here; see above). */
4175 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4176 || (target_is_non_stop_p ()
4177 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4179 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4181 if (record_full_is_used ())
4182 record_full_gdb_operation_disable_set ();
4184 /* When using hardware single-step, a SIGTRAP is reported for both
4185 a completed single-step and a software breakpoint. Need to
4186 differentiate between the two, as the latter needs adjusting
4187 but the former does not.
4189 The SIGTRAP can be due to a completed hardware single-step only if
4190 - we didn't insert software single-step breakpoints
4191 - this thread is currently being stepped
4193 If any of these events did not occur, we must have stopped due
4194 to hitting a software breakpoint, and have to back up to the
4197 As a special case, we could have hardware single-stepped a
4198 software breakpoint. In this case (prev_pc == breakpoint_pc),
4199 we also need to back up to the breakpoint address. */
4201 if (thread_has_single_step_breakpoints_set (thread)
4202 || !currently_stepping (thread)
4203 || (thread->stepped_breakpoint
4204 && thread->prev_pc == breakpoint_pc))
4205 regcache_write_pc (regcache, breakpoint_pc);
4207 do_cleanups (old_cleanups);
4212 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4214 for (frame = get_prev_frame (frame);
4216 frame = get_prev_frame (frame))
4218 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4220 if (get_frame_type (frame) != INLINE_FRAME)
4227 /* If the event thread has the stop requested flag set, pretend it
4228 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4232 handle_stop_requested (struct execution_control_state *ecs)
4234 if (ecs->event_thread->stop_requested)
4236 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4237 ecs->ws.value.sig = GDB_SIGNAL_0;
4238 handle_signal_stop (ecs);
4244 /* Auxiliary function that handles syscall entry/return events.
4245 It returns 1 if the inferior should keep going (and GDB
4246 should ignore the event), or 0 if the event deserves to be
4250 handle_syscall_event (struct execution_control_state *ecs)
4252 struct regcache *regcache;
4255 if (!ptid_equal (ecs->ptid, inferior_ptid))
4256 context_switch (ecs->ptid);
4258 regcache = get_thread_regcache (ecs->ptid);
4259 syscall_number = ecs->ws.value.syscall_number;
4260 stop_pc = regcache_read_pc (regcache);
4262 if (catch_syscall_enabled () > 0
4263 && catching_syscall_number (syscall_number) > 0)
4266 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4269 ecs->event_thread->control.stop_bpstat
4270 = bpstat_stop_status (get_regcache_aspace (regcache),
4271 stop_pc, ecs->ptid, &ecs->ws);
4273 if (handle_stop_requested (ecs))
4276 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4278 /* Catchpoint hit. */
4283 if (handle_stop_requested (ecs))
4286 /* If no catchpoint triggered for this, then keep going. */
4291 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4294 fill_in_stop_func (struct gdbarch *gdbarch,
4295 struct execution_control_state *ecs)
4297 if (!ecs->stop_func_filled_in)
4299 /* Don't care about return value; stop_func_start and stop_func_name
4300 will both be 0 if it doesn't work. */
4301 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4302 &ecs->stop_func_start, &ecs->stop_func_end);
4303 ecs->stop_func_start
4304 += gdbarch_deprecated_function_start_offset (gdbarch);
4306 if (gdbarch_skip_entrypoint_p (gdbarch))
4307 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4308 ecs->stop_func_start);
4310 ecs->stop_func_filled_in = 1;
4315 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4317 static enum stop_kind
4318 get_inferior_stop_soon (ptid_t ptid)
4320 struct inferior *inf = find_inferior_ptid (ptid);
4322 gdb_assert (inf != NULL);
4323 return inf->control.stop_soon;
4326 /* Wait for one event. Store the resulting waitstatus in WS, and
4327 return the event ptid. */
4330 wait_one (struct target_waitstatus *ws)
4333 ptid_t wait_ptid = minus_one_ptid;
4335 overlay_cache_invalid = 1;
4337 /* Flush target cache before starting to handle each event.
4338 Target was running and cache could be stale. This is just a
4339 heuristic. Running threads may modify target memory, but we
4340 don't get any event. */
4341 target_dcache_invalidate ();
4343 if (deprecated_target_wait_hook)
4344 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4346 event_ptid = target_wait (wait_ptid, ws, 0);
4349 print_target_wait_results (wait_ptid, event_ptid, ws);
4354 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4355 instead of the current thread. */
4356 #define THREAD_STOPPED_BY(REASON) \
4358 thread_stopped_by_ ## REASON (ptid_t ptid) \
4360 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4361 inferior_ptid = ptid; \
4363 return target_stopped_by_ ## REASON (); \
4366 /* Generate thread_stopped_by_watchpoint. */
4367 THREAD_STOPPED_BY (watchpoint)
4368 /* Generate thread_stopped_by_sw_breakpoint. */
4369 THREAD_STOPPED_BY (sw_breakpoint)
4370 /* Generate thread_stopped_by_hw_breakpoint. */
4371 THREAD_STOPPED_BY (hw_breakpoint)
4373 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4376 switch_to_thread_cleanup (void *ptid_p)
4378 ptid_t ptid = *(ptid_t *) ptid_p;
4380 switch_to_thread (ptid);
4383 /* Save the thread's event and stop reason to process it later. */
4386 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4388 struct regcache *regcache;
4389 struct address_space *aspace;
4393 std::string statstr = target_waitstatus_to_string (ws);
4395 fprintf_unfiltered (gdb_stdlog,
4396 "infrun: saving status %s for %d.%ld.%ld\n",
4398 ptid_get_pid (tp->ptid),
4399 ptid_get_lwp (tp->ptid),
4400 ptid_get_tid (tp->ptid));
4403 /* Record for later. */
4404 tp->suspend.waitstatus = *ws;
4405 tp->suspend.waitstatus_pending_p = 1;
4407 regcache = get_thread_regcache (tp->ptid);
4408 aspace = get_regcache_aspace (regcache);
4410 if (ws->kind == TARGET_WAITKIND_STOPPED
4411 && ws->value.sig == GDB_SIGNAL_TRAP)
4413 CORE_ADDR pc = regcache_read_pc (regcache);
4415 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4417 if (thread_stopped_by_watchpoint (tp->ptid))
4419 tp->suspend.stop_reason
4420 = TARGET_STOPPED_BY_WATCHPOINT;
4422 else if (target_supports_stopped_by_sw_breakpoint ()
4423 && thread_stopped_by_sw_breakpoint (tp->ptid))
4425 tp->suspend.stop_reason
4426 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4428 else if (target_supports_stopped_by_hw_breakpoint ()
4429 && thread_stopped_by_hw_breakpoint (tp->ptid))
4431 tp->suspend.stop_reason
4432 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4434 else if (!target_supports_stopped_by_hw_breakpoint ()
4435 && hardware_breakpoint_inserted_here_p (aspace,
4438 tp->suspend.stop_reason
4439 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4441 else if (!target_supports_stopped_by_sw_breakpoint ()
4442 && software_breakpoint_inserted_here_p (aspace,
4445 tp->suspend.stop_reason
4446 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4448 else if (!thread_has_single_step_breakpoints_set (tp)
4449 && currently_stepping (tp))
4451 tp->suspend.stop_reason
4452 = TARGET_STOPPED_BY_SINGLE_STEP;
4457 /* A cleanup that disables thread create/exit events. */
4460 disable_thread_events (void *arg)
4462 target_thread_events (0);
4468 stop_all_threads (void)
4470 /* We may need multiple passes to discover all threads. */
4474 struct cleanup *old_chain;
4476 gdb_assert (target_is_non_stop_p ());
4479 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4481 entry_ptid = inferior_ptid;
4482 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4484 target_thread_events (1);
4485 make_cleanup (disable_thread_events, NULL);
4487 /* Request threads to stop, and then wait for the stops. Because
4488 threads we already know about can spawn more threads while we're
4489 trying to stop them, and we only learn about new threads when we
4490 update the thread list, do this in a loop, and keep iterating
4491 until two passes find no threads that need to be stopped. */
4492 for (pass = 0; pass < 2; pass++, iterations++)
4495 fprintf_unfiltered (gdb_stdlog,
4496 "infrun: stop_all_threads, pass=%d, "
4497 "iterations=%d\n", pass, iterations);
4501 struct target_waitstatus ws;
4503 struct thread_info *t;
4505 update_thread_list ();
4507 /* Go through all threads looking for threads that we need
4508 to tell the target to stop. */
4509 ALL_NON_EXITED_THREADS (t)
4513 /* If already stopping, don't request a stop again.
4514 We just haven't seen the notification yet. */
4515 if (!t->stop_requested)
4518 fprintf_unfiltered (gdb_stdlog,
4519 "infrun: %s executing, "
4521 target_pid_to_str (t->ptid));
4522 target_stop (t->ptid);
4523 t->stop_requested = 1;
4528 fprintf_unfiltered (gdb_stdlog,
4529 "infrun: %s executing, "
4530 "already stopping\n",
4531 target_pid_to_str (t->ptid));
4534 if (t->stop_requested)
4540 fprintf_unfiltered (gdb_stdlog,
4541 "infrun: %s not executing\n",
4542 target_pid_to_str (t->ptid));
4544 /* The thread may be not executing, but still be
4545 resumed with a pending status to process. */
4553 /* If we find new threads on the second iteration, restart
4554 over. We want to see two iterations in a row with all
4559 event_ptid = wait_one (&ws);
4560 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4562 /* All resumed threads exited. */
4564 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4565 || ws.kind == TARGET_WAITKIND_EXITED
4566 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4570 ptid_t ptid = pid_to_ptid (ws.value.integer);
4572 fprintf_unfiltered (gdb_stdlog,
4573 "infrun: %s exited while "
4574 "stopping threads\n",
4575 target_pid_to_str (ptid));
4580 struct inferior *inf;
4582 t = find_thread_ptid (event_ptid);
4584 t = add_thread (event_ptid);
4586 t->stop_requested = 0;
4589 t->control.may_range_step = 0;
4591 /* This may be the first time we see the inferior report
4593 inf = find_inferior_ptid (event_ptid);
4594 if (inf->needs_setup)
4596 switch_to_thread_no_regs (t);
4600 if (ws.kind == TARGET_WAITKIND_STOPPED
4601 && ws.value.sig == GDB_SIGNAL_0)
4603 /* We caught the event that we intended to catch, so
4604 there's no event pending. */
4605 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4606 t->suspend.waitstatus_pending_p = 0;
4608 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4610 /* Add it back to the step-over queue. */
4613 fprintf_unfiltered (gdb_stdlog,
4614 "infrun: displaced-step of %s "
4615 "canceled: adding back to the "
4616 "step-over queue\n",
4617 target_pid_to_str (t->ptid));
4619 t->control.trap_expected = 0;
4620 thread_step_over_chain_enqueue (t);
4625 enum gdb_signal sig;
4626 struct regcache *regcache;
4630 std::string statstr = target_waitstatus_to_string (&ws);
4632 fprintf_unfiltered (gdb_stdlog,
4633 "infrun: target_wait %s, saving "
4634 "status for %d.%ld.%ld\n",
4636 ptid_get_pid (t->ptid),
4637 ptid_get_lwp (t->ptid),
4638 ptid_get_tid (t->ptid));
4641 /* Record for later. */
4642 save_waitstatus (t, &ws);
4644 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4645 ? ws.value.sig : GDB_SIGNAL_0);
4647 if (displaced_step_fixup (t->ptid, sig) < 0)
4649 /* Add it back to the step-over queue. */
4650 t->control.trap_expected = 0;
4651 thread_step_over_chain_enqueue (t);
4654 regcache = get_thread_regcache (t->ptid);
4655 t->suspend.stop_pc = regcache_read_pc (regcache);
4659 fprintf_unfiltered (gdb_stdlog,
4660 "infrun: saved stop_pc=%s for %s "
4661 "(currently_stepping=%d)\n",
4662 paddress (target_gdbarch (),
4663 t->suspend.stop_pc),
4664 target_pid_to_str (t->ptid),
4665 currently_stepping (t));
4672 do_cleanups (old_chain);
4675 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4678 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4681 handle_no_resumed (struct execution_control_state *ecs)
4683 struct inferior *inf;
4684 struct thread_info *thread;
4686 if (target_can_async_p ())
4693 if (ui->prompt_state == PROMPT_BLOCKED)
4701 /* There were no unwaited-for children left in the target, but,
4702 we're not synchronously waiting for events either. Just
4706 fprintf_unfiltered (gdb_stdlog,
4707 "infrun: TARGET_WAITKIND_NO_RESUMED "
4708 "(ignoring: bg)\n");
4709 prepare_to_wait (ecs);
4714 /* Otherwise, if we were running a synchronous execution command, we
4715 may need to cancel it and give the user back the terminal.
4717 In non-stop mode, the target can't tell whether we've already
4718 consumed previous stop events, so it can end up sending us a
4719 no-resumed event like so:
4721 #0 - thread 1 is left stopped
4723 #1 - thread 2 is resumed and hits breakpoint
4724 -> TARGET_WAITKIND_STOPPED
4726 #2 - thread 3 is resumed and exits
4727 this is the last resumed thread, so
4728 -> TARGET_WAITKIND_NO_RESUMED
4730 #3 - gdb processes stop for thread 2 and decides to re-resume
4733 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4734 thread 2 is now resumed, so the event should be ignored.
4736 IOW, if the stop for thread 2 doesn't end a foreground command,
4737 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4738 event. But it could be that the event meant that thread 2 itself
4739 (or whatever other thread was the last resumed thread) exited.
4741 To address this we refresh the thread list and check whether we
4742 have resumed threads _now_. In the example above, this removes
4743 thread 3 from the thread list. If thread 2 was re-resumed, we
4744 ignore this event. If we find no thread resumed, then we cancel
4745 the synchronous command show "no unwaited-for " to the user. */
4746 update_thread_list ();
4748 ALL_NON_EXITED_THREADS (thread)
4750 if (thread->executing
4751 || thread->suspend.waitstatus_pending_p)
4753 /* There were no unwaited-for children left in the target at
4754 some point, but there are now. Just ignore. */
4756 fprintf_unfiltered (gdb_stdlog,
4757 "infrun: TARGET_WAITKIND_NO_RESUMED "
4758 "(ignoring: found resumed)\n");
4759 prepare_to_wait (ecs);
4764 /* Note however that we may find no resumed thread because the whole
4765 process exited meanwhile (thus updating the thread list results
4766 in an empty thread list). In this case we know we'll be getting
4767 a process exit event shortly. */
4773 thread = any_live_thread_of_process (inf->pid);
4777 fprintf_unfiltered (gdb_stdlog,
4778 "infrun: TARGET_WAITKIND_NO_RESUMED "
4779 "(expect process exit)\n");
4780 prepare_to_wait (ecs);
4785 /* Go ahead and report the event. */
4789 /* Given an execution control state that has been freshly filled in by
4790 an event from the inferior, figure out what it means and take
4793 The alternatives are:
4795 1) stop_waiting and return; to really stop and return to the
4798 2) keep_going and return; to wait for the next event (set
4799 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4803 handle_inferior_event_1 (struct execution_control_state *ecs)
4805 enum stop_kind stop_soon;
4807 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4809 /* We had an event in the inferior, but we are not interested in
4810 handling it at this level. The lower layers have already
4811 done what needs to be done, if anything.
4813 One of the possible circumstances for this is when the
4814 inferior produces output for the console. The inferior has
4815 not stopped, and we are ignoring the event. Another possible
4816 circumstance is any event which the lower level knows will be
4817 reported multiple times without an intervening resume. */
4819 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4820 prepare_to_wait (ecs);
4824 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4827 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4828 prepare_to_wait (ecs);
4832 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4833 && handle_no_resumed (ecs))
4836 /* Cache the last pid/waitstatus. */
4837 set_last_target_status (ecs->ptid, ecs->ws);
4839 /* Always clear state belonging to the previous time we stopped. */
4840 stop_stack_dummy = STOP_NONE;
4842 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4844 /* No unwaited-for children left. IOW, all resumed children
4847 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4849 stop_print_frame = 0;
4854 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4855 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4857 ecs->event_thread = find_thread_ptid (ecs->ptid);
4858 /* If it's a new thread, add it to the thread database. */
4859 if (ecs->event_thread == NULL)
4860 ecs->event_thread = add_thread (ecs->ptid);
4862 /* Disable range stepping. If the next step request could use a
4863 range, this will be end up re-enabled then. */
4864 ecs->event_thread->control.may_range_step = 0;
4867 /* Dependent on valid ECS->EVENT_THREAD. */
4868 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4870 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4871 reinit_frame_cache ();
4873 breakpoint_retire_moribund ();
4875 /* First, distinguish signals caused by the debugger from signals
4876 that have to do with the program's own actions. Note that
4877 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4878 on the operating system version. Here we detect when a SIGILL or
4879 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4880 something similar for SIGSEGV, since a SIGSEGV will be generated
4881 when we're trying to execute a breakpoint instruction on a
4882 non-executable stack. This happens for call dummy breakpoints
4883 for architectures like SPARC that place call dummies on the
4885 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4886 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4887 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4888 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4890 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4892 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
4893 regcache_read_pc (regcache)))
4896 fprintf_unfiltered (gdb_stdlog,
4897 "infrun: Treating signal as SIGTRAP\n");
4898 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4902 /* Mark the non-executing threads accordingly. In all-stop, all
4903 threads of all processes are stopped when we get any event
4904 reported. In non-stop mode, only the event thread stops. */
4908 if (!target_is_non_stop_p ())
4909 mark_ptid = minus_one_ptid;
4910 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4911 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4913 /* If we're handling a process exit in non-stop mode, even
4914 though threads haven't been deleted yet, one would think
4915 that there is nothing to do, as threads of the dead process
4916 will be soon deleted, and threads of any other process were
4917 left running. However, on some targets, threads survive a
4918 process exit event. E.g., for the "checkpoint" command,
4919 when the current checkpoint/fork exits, linux-fork.c
4920 automatically switches to another fork from within
4921 target_mourn_inferior, by associating the same
4922 inferior/thread to another fork. We haven't mourned yet at
4923 this point, but we must mark any threads left in the
4924 process as not-executing so that finish_thread_state marks
4925 them stopped (in the user's perspective) if/when we present
4926 the stop to the user. */
4927 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4930 mark_ptid = ecs->ptid;
4932 set_executing (mark_ptid, 0);
4934 /* Likewise the resumed flag. */
4935 set_resumed (mark_ptid, 0);
4938 switch (ecs->ws.kind)
4940 case TARGET_WAITKIND_LOADED:
4942 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4943 if (!ptid_equal (ecs->ptid, inferior_ptid))
4944 context_switch (ecs->ptid);
4945 /* Ignore gracefully during startup of the inferior, as it might
4946 be the shell which has just loaded some objects, otherwise
4947 add the symbols for the newly loaded objects. Also ignore at
4948 the beginning of an attach or remote session; we will query
4949 the full list of libraries once the connection is
4952 stop_soon = get_inferior_stop_soon (ecs->ptid);
4953 if (stop_soon == NO_STOP_QUIETLY)
4955 struct regcache *regcache;
4957 regcache = get_thread_regcache (ecs->ptid);
4959 handle_solib_event ();
4961 ecs->event_thread->control.stop_bpstat
4962 = bpstat_stop_status (get_regcache_aspace (regcache),
4963 stop_pc, ecs->ptid, &ecs->ws);
4965 if (handle_stop_requested (ecs))
4968 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4970 /* A catchpoint triggered. */
4971 process_event_stop_test (ecs);
4975 /* If requested, stop when the dynamic linker notifies
4976 gdb of events. This allows the user to get control
4977 and place breakpoints in initializer routines for
4978 dynamically loaded objects (among other things). */
4979 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4980 if (stop_on_solib_events)
4982 /* Make sure we print "Stopped due to solib-event" in
4984 stop_print_frame = 1;
4991 /* If we are skipping through a shell, or through shared library
4992 loading that we aren't interested in, resume the program. If
4993 we're running the program normally, also resume. */
4994 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4996 /* Loading of shared libraries might have changed breakpoint
4997 addresses. Make sure new breakpoints are inserted. */
4998 if (stop_soon == NO_STOP_QUIETLY)
4999 insert_breakpoints ();
5000 resume (GDB_SIGNAL_0);
5001 prepare_to_wait (ecs);
5005 /* But stop if we're attaching or setting up a remote
5007 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5008 || stop_soon == STOP_QUIETLY_REMOTE)
5011 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5016 internal_error (__FILE__, __LINE__,
5017 _("unhandled stop_soon: %d"), (int) stop_soon);
5019 case TARGET_WAITKIND_SPURIOUS:
5021 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5022 if (handle_stop_requested (ecs))
5024 if (!ptid_equal (ecs->ptid, inferior_ptid))
5025 context_switch (ecs->ptid);
5026 resume (GDB_SIGNAL_0);
5027 prepare_to_wait (ecs);
5030 case TARGET_WAITKIND_THREAD_CREATED:
5032 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5033 if (handle_stop_requested (ecs))
5035 if (!ptid_equal (ecs->ptid, inferior_ptid))
5036 context_switch (ecs->ptid);
5037 if (!switch_back_to_stepped_thread (ecs))
5041 case TARGET_WAITKIND_EXITED:
5042 case TARGET_WAITKIND_SIGNALLED:
5045 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5046 fprintf_unfiltered (gdb_stdlog,
5047 "infrun: TARGET_WAITKIND_EXITED\n");
5049 fprintf_unfiltered (gdb_stdlog,
5050 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5053 inferior_ptid = ecs->ptid;
5054 set_current_inferior (find_inferior_ptid (ecs->ptid));
5055 set_current_program_space (current_inferior ()->pspace);
5056 handle_vfork_child_exec_or_exit (0);
5057 target_terminal_ours (); /* Must do this before mourn anyway. */
5059 /* Clearing any previous state of convenience variables. */
5060 clear_exit_convenience_vars ();
5062 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5064 /* Record the exit code in the convenience variable $_exitcode, so
5065 that the user can inspect this again later. */
5066 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5067 (LONGEST) ecs->ws.value.integer);
5069 /* Also record this in the inferior itself. */
5070 current_inferior ()->has_exit_code = 1;
5071 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5073 /* Support the --return-child-result option. */
5074 return_child_result_value = ecs->ws.value.integer;
5076 observer_notify_exited (ecs->ws.value.integer);
5080 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5081 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5083 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5085 /* Set the value of the internal variable $_exitsignal,
5086 which holds the signal uncaught by the inferior. */
5087 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5088 gdbarch_gdb_signal_to_target (gdbarch,
5089 ecs->ws.value.sig));
5093 /* We don't have access to the target's method used for
5094 converting between signal numbers (GDB's internal
5095 representation <-> target's representation).
5096 Therefore, we cannot do a good job at displaying this
5097 information to the user. It's better to just warn
5098 her about it (if infrun debugging is enabled), and
5101 fprintf_filtered (gdb_stdlog, _("\
5102 Cannot fill $_exitsignal with the correct signal number.\n"));
5105 observer_notify_signal_exited (ecs->ws.value.sig);
5108 gdb_flush (gdb_stdout);
5109 target_mourn_inferior (inferior_ptid);
5110 stop_print_frame = 0;
5114 /* The following are the only cases in which we keep going;
5115 the above cases end in a continue or goto. */
5116 case TARGET_WAITKIND_FORKED:
5117 case TARGET_WAITKIND_VFORKED:
5120 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5121 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5123 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5126 /* Check whether the inferior is displaced stepping. */
5128 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5129 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5131 /* If checking displaced stepping is supported, and thread
5132 ecs->ptid is displaced stepping. */
5133 if (displaced_step_in_progress_thread (ecs->ptid))
5135 struct inferior *parent_inf
5136 = find_inferior_ptid (ecs->ptid);
5137 struct regcache *child_regcache;
5138 CORE_ADDR parent_pc;
5140 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5141 indicating that the displaced stepping of syscall instruction
5142 has been done. Perform cleanup for parent process here. Note
5143 that this operation also cleans up the child process for vfork,
5144 because their pages are shared. */
5145 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
5146 /* Start a new step-over in another thread if there's one
5150 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5152 struct displaced_step_inferior_state *displaced
5153 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
5155 /* Restore scratch pad for child process. */
5156 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5159 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5160 the child's PC is also within the scratchpad. Set the child's PC
5161 to the parent's PC value, which has already been fixed up.
5162 FIXME: we use the parent's aspace here, although we're touching
5163 the child, because the child hasn't been added to the inferior
5164 list yet at this point. */
5167 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5169 parent_inf->aspace);
5170 /* Read PC value of parent process. */
5171 parent_pc = regcache_read_pc (regcache);
5173 if (debug_displaced)
5174 fprintf_unfiltered (gdb_stdlog,
5175 "displaced: write child pc from %s to %s\n",
5177 regcache_read_pc (child_regcache)),
5178 paddress (gdbarch, parent_pc));
5180 regcache_write_pc (child_regcache, parent_pc);
5184 if (!ptid_equal (ecs->ptid, inferior_ptid))
5185 context_switch (ecs->ptid);
5187 /* Immediately detach breakpoints from the child before there's
5188 any chance of letting the user delete breakpoints from the
5189 breakpoint lists. If we don't do this early, it's easy to
5190 leave left over traps in the child, vis: "break foo; catch
5191 fork; c; <fork>; del; c; <child calls foo>". We only follow
5192 the fork on the last `continue', and by that time the
5193 breakpoint at "foo" is long gone from the breakpoint table.
5194 If we vforked, then we don't need to unpatch here, since both
5195 parent and child are sharing the same memory pages; we'll
5196 need to unpatch at follow/detach time instead to be certain
5197 that new breakpoints added between catchpoint hit time and
5198 vfork follow are detached. */
5199 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5201 /* This won't actually modify the breakpoint list, but will
5202 physically remove the breakpoints from the child. */
5203 detach_breakpoints (ecs->ws.value.related_pid);
5206 delete_just_stopped_threads_single_step_breakpoints ();
5208 /* In case the event is caught by a catchpoint, remember that
5209 the event is to be followed at the next resume of the thread,
5210 and not immediately. */
5211 ecs->event_thread->pending_follow = ecs->ws;
5213 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5215 ecs->event_thread->control.stop_bpstat
5216 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5217 stop_pc, ecs->ptid, &ecs->ws);
5219 if (handle_stop_requested (ecs))
5222 /* If no catchpoint triggered for this, then keep going. Note
5223 that we're interested in knowing the bpstat actually causes a
5224 stop, not just if it may explain the signal. Software
5225 watchpoints, for example, always appear in the bpstat. */
5226 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5232 = (follow_fork_mode_string == follow_fork_mode_child);
5234 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5236 should_resume = follow_fork ();
5239 child = ecs->ws.value.related_pid;
5241 /* At this point, the parent is marked running, and the
5242 child is marked stopped. */
5244 /* If not resuming the parent, mark it stopped. */
5245 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5246 set_running (parent, 0);
5248 /* If resuming the child, mark it running. */
5249 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5250 set_running (child, 1);
5252 /* In non-stop mode, also resume the other branch. */
5253 if (!detach_fork && (non_stop
5254 || (sched_multi && target_is_non_stop_p ())))
5257 switch_to_thread (parent);
5259 switch_to_thread (child);
5261 ecs->event_thread = inferior_thread ();
5262 ecs->ptid = inferior_ptid;
5267 switch_to_thread (child);
5269 switch_to_thread (parent);
5271 ecs->event_thread = inferior_thread ();
5272 ecs->ptid = inferior_ptid;
5280 process_event_stop_test (ecs);
5283 case TARGET_WAITKIND_VFORK_DONE:
5284 /* Done with the shared memory region. Re-insert breakpoints in
5285 the parent, and keep going. */
5288 fprintf_unfiltered (gdb_stdlog,
5289 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5291 if (!ptid_equal (ecs->ptid, inferior_ptid))
5292 context_switch (ecs->ptid);
5294 current_inferior ()->waiting_for_vfork_done = 0;
5295 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5297 if (handle_stop_requested (ecs))
5300 /* This also takes care of reinserting breakpoints in the
5301 previously locked inferior. */
5305 case TARGET_WAITKIND_EXECD:
5307 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5309 if (!ptid_equal (ecs->ptid, inferior_ptid))
5310 context_switch (ecs->ptid);
5312 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5314 /* Do whatever is necessary to the parent branch of the vfork. */
5315 handle_vfork_child_exec_or_exit (1);
5317 /* This causes the eventpoints and symbol table to be reset.
5318 Must do this now, before trying to determine whether to
5320 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5322 /* In follow_exec we may have deleted the original thread and
5323 created a new one. Make sure that the event thread is the
5324 execd thread for that case (this is a nop otherwise). */
5325 ecs->event_thread = inferior_thread ();
5327 ecs->event_thread->control.stop_bpstat
5328 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5329 stop_pc, ecs->ptid, &ecs->ws);
5331 /* Note that this may be referenced from inside
5332 bpstat_stop_status above, through inferior_has_execd. */
5333 xfree (ecs->ws.value.execd_pathname);
5334 ecs->ws.value.execd_pathname = NULL;
5336 if (handle_stop_requested (ecs))
5339 /* If no catchpoint triggered for this, then keep going. */
5340 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5342 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5346 process_event_stop_test (ecs);
5349 /* Be careful not to try to gather much state about a thread
5350 that's in a syscall. It's frequently a losing proposition. */
5351 case TARGET_WAITKIND_SYSCALL_ENTRY:
5353 fprintf_unfiltered (gdb_stdlog,
5354 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5355 /* Getting the current syscall number. */
5356 if (handle_syscall_event (ecs) == 0)
5357 process_event_stop_test (ecs);
5360 /* Before examining the threads further, step this thread to
5361 get it entirely out of the syscall. (We get notice of the
5362 event when the thread is just on the verge of exiting a
5363 syscall. Stepping one instruction seems to get it back
5365 case TARGET_WAITKIND_SYSCALL_RETURN:
5367 fprintf_unfiltered (gdb_stdlog,
5368 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5369 if (handle_syscall_event (ecs) == 0)
5370 process_event_stop_test (ecs);
5373 case TARGET_WAITKIND_STOPPED:
5375 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5376 handle_signal_stop (ecs);
5379 case TARGET_WAITKIND_NO_HISTORY:
5381 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5382 /* Reverse execution: target ran out of history info. */
5384 /* Switch to the stopped thread. */
5385 if (!ptid_equal (ecs->ptid, inferior_ptid))
5386 context_switch (ecs->ptid);
5388 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5390 delete_just_stopped_threads_single_step_breakpoints ();
5391 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5393 if (handle_stop_requested (ecs))
5396 observer_notify_no_history ();
5402 /* A wrapper around handle_inferior_event_1, which also makes sure
5403 that all temporary struct value objects that were created during
5404 the handling of the event get deleted at the end. */
5407 handle_inferior_event (struct execution_control_state *ecs)
5409 struct value *mark = value_mark ();
5411 handle_inferior_event_1 (ecs);
5412 /* Purge all temporary values created during the event handling,
5413 as it could be a long time before we return to the command level
5414 where such values would otherwise be purged. */
5415 value_free_to_mark (mark);
5418 /* Restart threads back to what they were trying to do back when we
5419 paused them for an in-line step-over. The EVENT_THREAD thread is
5423 restart_threads (struct thread_info *event_thread)
5425 struct thread_info *tp;
5427 /* In case the instruction just stepped spawned a new thread. */
5428 update_thread_list ();
5430 ALL_NON_EXITED_THREADS (tp)
5432 if (tp == event_thread)
5435 fprintf_unfiltered (gdb_stdlog,
5436 "infrun: restart threads: "
5437 "[%s] is event thread\n",
5438 target_pid_to_str (tp->ptid));
5442 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5445 fprintf_unfiltered (gdb_stdlog,
5446 "infrun: restart threads: "
5447 "[%s] not meant to be running\n",
5448 target_pid_to_str (tp->ptid));
5455 fprintf_unfiltered (gdb_stdlog,
5456 "infrun: restart threads: [%s] resumed\n",
5457 target_pid_to_str (tp->ptid));
5458 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5462 if (thread_is_in_step_over_chain (tp))
5465 fprintf_unfiltered (gdb_stdlog,
5466 "infrun: restart threads: "
5467 "[%s] needs step-over\n",
5468 target_pid_to_str (tp->ptid));
5469 gdb_assert (!tp->resumed);
5474 if (tp->suspend.waitstatus_pending_p)
5477 fprintf_unfiltered (gdb_stdlog,
5478 "infrun: restart threads: "
5479 "[%s] has pending status\n",
5480 target_pid_to_str (tp->ptid));
5485 gdb_assert (!tp->stop_requested);
5487 /* If some thread needs to start a step-over at this point, it
5488 should still be in the step-over queue, and thus skipped
5490 if (thread_still_needs_step_over (tp))
5492 internal_error (__FILE__, __LINE__,
5493 "thread [%s] needs a step-over, but not in "
5494 "step-over queue\n",
5495 target_pid_to_str (tp->ptid));
5498 if (currently_stepping (tp))
5501 fprintf_unfiltered (gdb_stdlog,
5502 "infrun: restart threads: [%s] was stepping\n",
5503 target_pid_to_str (tp->ptid));
5504 keep_going_stepped_thread (tp);
5508 struct execution_control_state ecss;
5509 struct execution_control_state *ecs = &ecss;
5512 fprintf_unfiltered (gdb_stdlog,
5513 "infrun: restart threads: [%s] continuing\n",
5514 target_pid_to_str (tp->ptid));
5515 reset_ecs (ecs, tp);
5516 switch_to_thread (tp->ptid);
5517 keep_going_pass_signal (ecs);
5522 /* Callback for iterate_over_threads. Find a resumed thread that has
5523 a pending waitstatus. */
5526 resumed_thread_with_pending_status (struct thread_info *tp,
5530 && tp->suspend.waitstatus_pending_p);
5533 /* Called when we get an event that may finish an in-line or
5534 out-of-line (displaced stepping) step-over started previously.
5535 Return true if the event is processed and we should go back to the
5536 event loop; false if the caller should continue processing the
5540 finish_step_over (struct execution_control_state *ecs)
5542 int had_step_over_info;
5544 displaced_step_fixup (ecs->ptid,
5545 ecs->event_thread->suspend.stop_signal);
5547 had_step_over_info = step_over_info_valid_p ();
5549 if (had_step_over_info)
5551 /* If we're stepping over a breakpoint with all threads locked,
5552 then only the thread that was stepped should be reporting
5554 gdb_assert (ecs->event_thread->control.trap_expected);
5556 clear_step_over_info ();
5559 if (!target_is_non_stop_p ())
5562 /* Start a new step-over in another thread if there's one that
5566 /* If we were stepping over a breakpoint before, and haven't started
5567 a new in-line step-over sequence, then restart all other threads
5568 (except the event thread). We can't do this in all-stop, as then
5569 e.g., we wouldn't be able to issue any other remote packet until
5570 these other threads stop. */
5571 if (had_step_over_info && !step_over_info_valid_p ())
5573 struct thread_info *pending;
5575 /* If we only have threads with pending statuses, the restart
5576 below won't restart any thread and so nothing re-inserts the
5577 breakpoint we just stepped over. But we need it inserted
5578 when we later process the pending events, otherwise if
5579 another thread has a pending event for this breakpoint too,
5580 we'd discard its event (because the breakpoint that
5581 originally caused the event was no longer inserted). */
5582 context_switch (ecs->ptid);
5583 insert_breakpoints ();
5585 restart_threads (ecs->event_thread);
5587 /* If we have events pending, go through handle_inferior_event
5588 again, picking up a pending event at random. This avoids
5589 thread starvation. */
5591 /* But not if we just stepped over a watchpoint in order to let
5592 the instruction execute so we can evaluate its expression.
5593 The set of watchpoints that triggered is recorded in the
5594 breakpoint objects themselves (see bp->watchpoint_triggered).
5595 If we processed another event first, that other event could
5596 clobber this info. */
5597 if (ecs->event_thread->stepping_over_watchpoint)
5600 pending = iterate_over_threads (resumed_thread_with_pending_status,
5602 if (pending != NULL)
5604 struct thread_info *tp = ecs->event_thread;
5605 struct regcache *regcache;
5609 fprintf_unfiltered (gdb_stdlog,
5610 "infrun: found resumed threads with "
5611 "pending events, saving status\n");
5614 gdb_assert (pending != tp);
5616 /* Record the event thread's event for later. */
5617 save_waitstatus (tp, &ecs->ws);
5618 /* This was cleared early, by handle_inferior_event. Set it
5619 so this pending event is considered by
5623 gdb_assert (!tp->executing);
5625 regcache = get_thread_regcache (tp->ptid);
5626 tp->suspend.stop_pc = regcache_read_pc (regcache);
5630 fprintf_unfiltered (gdb_stdlog,
5631 "infrun: saved stop_pc=%s for %s "
5632 "(currently_stepping=%d)\n",
5633 paddress (target_gdbarch (),
5634 tp->suspend.stop_pc),
5635 target_pid_to_str (tp->ptid),
5636 currently_stepping (tp));
5639 /* This in-line step-over finished; clear this so we won't
5640 start a new one. This is what handle_signal_stop would
5641 do, if we returned false. */
5642 tp->stepping_over_breakpoint = 0;
5644 /* Wake up the event loop again. */
5645 mark_async_event_handler (infrun_async_inferior_event_token);
5647 prepare_to_wait (ecs);
5655 /* Come here when the program has stopped with a signal. */
5658 handle_signal_stop (struct execution_control_state *ecs)
5660 struct frame_info *frame;
5661 struct gdbarch *gdbarch;
5662 int stopped_by_watchpoint;
5663 enum stop_kind stop_soon;
5666 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5668 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5670 /* Do we need to clean up the state of a thread that has
5671 completed a displaced single-step? (Doing so usually affects
5672 the PC, so do it here, before we set stop_pc.) */
5673 if (finish_step_over (ecs))
5676 /* If we either finished a single-step or hit a breakpoint, but
5677 the user wanted this thread to be stopped, pretend we got a
5678 SIG0 (generic unsignaled stop). */
5679 if (ecs->event_thread->stop_requested
5680 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5681 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5683 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5687 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5688 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5689 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5691 inferior_ptid = ecs->ptid;
5693 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5694 paddress (gdbarch, stop_pc));
5695 if (target_stopped_by_watchpoint ())
5699 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5701 if (target_stopped_data_address (¤t_target, &addr))
5702 fprintf_unfiltered (gdb_stdlog,
5703 "infrun: stopped data address = %s\n",
5704 paddress (gdbarch, addr));
5706 fprintf_unfiltered (gdb_stdlog,
5707 "infrun: (no data address available)\n");
5711 /* This is originated from start_remote(), start_inferior() and
5712 shared libraries hook functions. */
5713 stop_soon = get_inferior_stop_soon (ecs->ptid);
5714 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5716 if (!ptid_equal (ecs->ptid, inferior_ptid))
5717 context_switch (ecs->ptid);
5719 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5720 stop_print_frame = 1;
5725 /* This originates from attach_command(). We need to overwrite
5726 the stop_signal here, because some kernels don't ignore a
5727 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5728 See more comments in inferior.h. On the other hand, if we
5729 get a non-SIGSTOP, report it to the user - assume the backend
5730 will handle the SIGSTOP if it should show up later.
5732 Also consider that the attach is complete when we see a
5733 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5734 target extended-remote report it instead of a SIGSTOP
5735 (e.g. gdbserver). We already rely on SIGTRAP being our
5736 signal, so this is no exception.
5738 Also consider that the attach is complete when we see a
5739 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5740 the target to stop all threads of the inferior, in case the
5741 low level attach operation doesn't stop them implicitly. If
5742 they weren't stopped implicitly, then the stub will report a
5743 GDB_SIGNAL_0, meaning: stopped for no particular reason
5744 other than GDB's request. */
5745 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5746 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5747 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5748 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5750 stop_print_frame = 1;
5752 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5756 /* See if something interesting happened to the non-current thread. If
5757 so, then switch to that thread. */
5758 if (!ptid_equal (ecs->ptid, inferior_ptid))
5761 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5763 context_switch (ecs->ptid);
5765 if (deprecated_context_hook)
5766 deprecated_context_hook (ptid_to_global_thread_id (ecs->ptid));
5769 /* At this point, get hold of the now-current thread's frame. */
5770 frame = get_current_frame ();
5771 gdbarch = get_frame_arch (frame);
5773 /* Pull the single step breakpoints out of the target. */
5774 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5776 struct regcache *regcache;
5777 struct address_space *aspace;
5780 regcache = get_thread_regcache (ecs->ptid);
5781 aspace = get_regcache_aspace (regcache);
5782 pc = regcache_read_pc (regcache);
5784 /* However, before doing so, if this single-step breakpoint was
5785 actually for another thread, set this thread up for moving
5787 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5790 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5794 fprintf_unfiltered (gdb_stdlog,
5795 "infrun: [%s] hit another thread's "
5796 "single-step breakpoint\n",
5797 target_pid_to_str (ecs->ptid));
5799 ecs->hit_singlestep_breakpoint = 1;
5806 fprintf_unfiltered (gdb_stdlog,
5807 "infrun: [%s] hit its "
5808 "single-step breakpoint\n",
5809 target_pid_to_str (ecs->ptid));
5813 delete_just_stopped_threads_single_step_breakpoints ();
5815 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5816 && ecs->event_thread->control.trap_expected
5817 && ecs->event_thread->stepping_over_watchpoint)
5818 stopped_by_watchpoint = 0;
5820 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5822 /* If necessary, step over this watchpoint. We'll be back to display
5824 if (stopped_by_watchpoint
5825 && (target_have_steppable_watchpoint
5826 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5828 /* At this point, we are stopped at an instruction which has
5829 attempted to write to a piece of memory under control of
5830 a watchpoint. The instruction hasn't actually executed
5831 yet. If we were to evaluate the watchpoint expression
5832 now, we would get the old value, and therefore no change
5833 would seem to have occurred.
5835 In order to make watchpoints work `right', we really need
5836 to complete the memory write, and then evaluate the
5837 watchpoint expression. We do this by single-stepping the
5840 It may not be necessary to disable the watchpoint to step over
5841 it. For example, the PA can (with some kernel cooperation)
5842 single step over a watchpoint without disabling the watchpoint.
5844 It is far more common to need to disable a watchpoint to step
5845 the inferior over it. If we have non-steppable watchpoints,
5846 we must disable the current watchpoint; it's simplest to
5847 disable all watchpoints.
5849 Any breakpoint at PC must also be stepped over -- if there's
5850 one, it will have already triggered before the watchpoint
5851 triggered, and we either already reported it to the user, or
5852 it didn't cause a stop and we called keep_going. In either
5853 case, if there was a breakpoint at PC, we must be trying to
5855 ecs->event_thread->stepping_over_watchpoint = 1;
5860 ecs->event_thread->stepping_over_breakpoint = 0;
5861 ecs->event_thread->stepping_over_watchpoint = 0;
5862 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5863 ecs->event_thread->control.stop_step = 0;
5864 stop_print_frame = 1;
5865 stopped_by_random_signal = 0;
5867 /* Hide inlined functions starting here, unless we just performed stepi or
5868 nexti. After stepi and nexti, always show the innermost frame (not any
5869 inline function call sites). */
5870 if (ecs->event_thread->control.step_range_end != 1)
5872 struct address_space *aspace =
5873 get_regcache_aspace (get_thread_regcache (ecs->ptid));
5875 /* skip_inline_frames is expensive, so we avoid it if we can
5876 determine that the address is one where functions cannot have
5877 been inlined. This improves performance with inferiors that
5878 load a lot of shared libraries, because the solib event
5879 breakpoint is defined as the address of a function (i.e. not
5880 inline). Note that we have to check the previous PC as well
5881 as the current one to catch cases when we have just
5882 single-stepped off a breakpoint prior to reinstating it.
5883 Note that we're assuming that the code we single-step to is
5884 not inline, but that's not definitive: there's nothing
5885 preventing the event breakpoint function from containing
5886 inlined code, and the single-step ending up there. If the
5887 user had set a breakpoint on that inlined code, the missing
5888 skip_inline_frames call would break things. Fortunately
5889 that's an extremely unlikely scenario. */
5890 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5891 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5892 && ecs->event_thread->control.trap_expected
5893 && pc_at_non_inline_function (aspace,
5894 ecs->event_thread->prev_pc,
5897 skip_inline_frames (ecs->ptid);
5899 /* Re-fetch current thread's frame in case that invalidated
5901 frame = get_current_frame ();
5902 gdbarch = get_frame_arch (frame);
5906 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5907 && ecs->event_thread->control.trap_expected
5908 && gdbarch_single_step_through_delay_p (gdbarch)
5909 && currently_stepping (ecs->event_thread))
5911 /* We're trying to step off a breakpoint. Turns out that we're
5912 also on an instruction that needs to be stepped multiple
5913 times before it's been fully executing. E.g., architectures
5914 with a delay slot. It needs to be stepped twice, once for
5915 the instruction and once for the delay slot. */
5916 int step_through_delay
5917 = gdbarch_single_step_through_delay (gdbarch, frame);
5919 if (debug_infrun && step_through_delay)
5920 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5921 if (ecs->event_thread->control.step_range_end == 0
5922 && step_through_delay)
5924 /* The user issued a continue when stopped at a breakpoint.
5925 Set up for another trap and get out of here. */
5926 ecs->event_thread->stepping_over_breakpoint = 1;
5930 else if (step_through_delay)
5932 /* The user issued a step when stopped at a breakpoint.
5933 Maybe we should stop, maybe we should not - the delay
5934 slot *might* correspond to a line of source. In any
5935 case, don't decide that here, just set
5936 ecs->stepping_over_breakpoint, making sure we
5937 single-step again before breakpoints are re-inserted. */
5938 ecs->event_thread->stepping_over_breakpoint = 1;
5942 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5943 handles this event. */
5944 ecs->event_thread->control.stop_bpstat
5945 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5946 stop_pc, ecs->ptid, &ecs->ws);
5948 /* Following in case break condition called a
5950 stop_print_frame = 1;
5952 /* This is where we handle "moribund" watchpoints. Unlike
5953 software breakpoints traps, hardware watchpoint traps are
5954 always distinguishable from random traps. If no high-level
5955 watchpoint is associated with the reported stop data address
5956 anymore, then the bpstat does not explain the signal ---
5957 simply make sure to ignore it if `stopped_by_watchpoint' is
5961 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5962 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5964 && stopped_by_watchpoint)
5965 fprintf_unfiltered (gdb_stdlog,
5966 "infrun: no user watchpoint explains "
5967 "watchpoint SIGTRAP, ignoring\n");
5969 /* NOTE: cagney/2003-03-29: These checks for a random signal
5970 at one stage in the past included checks for an inferior
5971 function call's call dummy's return breakpoint. The original
5972 comment, that went with the test, read:
5974 ``End of a stack dummy. Some systems (e.g. Sony news) give
5975 another signal besides SIGTRAP, so check here as well as
5978 If someone ever tries to get call dummys on a
5979 non-executable stack to work (where the target would stop
5980 with something like a SIGSEGV), then those tests might need
5981 to be re-instated. Given, however, that the tests were only
5982 enabled when momentary breakpoints were not being used, I
5983 suspect that it won't be the case.
5985 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5986 be necessary for call dummies on a non-executable stack on
5989 /* See if the breakpoints module can explain the signal. */
5991 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5992 ecs->event_thread->suspend.stop_signal);
5994 /* Maybe this was a trap for a software breakpoint that has since
5996 if (random_signal && target_stopped_by_sw_breakpoint ())
5998 if (program_breakpoint_here_p (gdbarch, stop_pc))
6000 struct regcache *regcache;
6003 /* Re-adjust PC to what the program would see if GDB was not
6005 regcache = get_thread_regcache (ecs->event_thread->ptid);
6006 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
6009 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
6011 if (record_full_is_used ())
6012 record_full_gdb_operation_disable_set ();
6014 regcache_write_pc (regcache, stop_pc + decr_pc);
6016 do_cleanups (old_cleanups);
6021 /* A delayed software breakpoint event. Ignore the trap. */
6023 fprintf_unfiltered (gdb_stdlog,
6024 "infrun: delayed software breakpoint "
6025 "trap, ignoring\n");
6030 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6031 has since been removed. */
6032 if (random_signal && target_stopped_by_hw_breakpoint ())
6034 /* A delayed hardware breakpoint event. Ignore the trap. */
6036 fprintf_unfiltered (gdb_stdlog,
6037 "infrun: delayed hardware breakpoint/watchpoint "
6038 "trap, ignoring\n");
6042 /* If not, perhaps stepping/nexting can. */
6044 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6045 && currently_stepping (ecs->event_thread));
6047 /* Perhaps the thread hit a single-step breakpoint of _another_
6048 thread. Single-step breakpoints are transparent to the
6049 breakpoints module. */
6051 random_signal = !ecs->hit_singlestep_breakpoint;
6053 /* No? Perhaps we got a moribund watchpoint. */
6055 random_signal = !stopped_by_watchpoint;
6057 /* Always stop if the user explicitly requested this thread to
6059 if (ecs->event_thread->stop_requested)
6063 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6066 /* For the program's own signals, act according to
6067 the signal handling tables. */
6071 /* Signal not for debugging purposes. */
6072 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6073 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6076 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6077 gdb_signal_to_symbol_string (stop_signal));
6079 stopped_by_random_signal = 1;
6081 /* Always stop on signals if we're either just gaining control
6082 of the program, or the user explicitly requested this thread
6083 to remain stopped. */
6084 if (stop_soon != NO_STOP_QUIETLY
6085 || ecs->event_thread->stop_requested
6087 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6093 /* Notify observers the signal has "handle print" set. Note we
6094 returned early above if stopping; normal_stop handles the
6095 printing in that case. */
6096 if (signal_print[ecs->event_thread->suspend.stop_signal])
6098 /* The signal table tells us to print about this signal. */
6099 target_terminal_ours_for_output ();
6100 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
6101 target_terminal_inferior ();
6104 /* Clear the signal if it should not be passed. */
6105 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6106 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6108 if (ecs->event_thread->prev_pc == stop_pc
6109 && ecs->event_thread->control.trap_expected
6110 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6112 /* We were just starting a new sequence, attempting to
6113 single-step off of a breakpoint and expecting a SIGTRAP.
6114 Instead this signal arrives. This signal will take us out
6115 of the stepping range so GDB needs to remember to, when
6116 the signal handler returns, resume stepping off that
6118 /* To simplify things, "continue" is forced to use the same
6119 code paths as single-step - set a breakpoint at the
6120 signal return address and then, once hit, step off that
6123 fprintf_unfiltered (gdb_stdlog,
6124 "infrun: signal arrived while stepping over "
6127 insert_hp_step_resume_breakpoint_at_frame (frame);
6128 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6129 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6130 ecs->event_thread->control.trap_expected = 0;
6132 /* If we were nexting/stepping some other thread, switch to
6133 it, so that we don't continue it, losing control. */
6134 if (!switch_back_to_stepped_thread (ecs))
6139 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6140 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6141 || ecs->event_thread->control.step_range_end == 1)
6142 && frame_id_eq (get_stack_frame_id (frame),
6143 ecs->event_thread->control.step_stack_frame_id)
6144 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6146 /* The inferior is about to take a signal that will take it
6147 out of the single step range. Set a breakpoint at the
6148 current PC (which is presumably where the signal handler
6149 will eventually return) and then allow the inferior to
6152 Note that this is only needed for a signal delivered
6153 while in the single-step range. Nested signals aren't a
6154 problem as they eventually all return. */
6156 fprintf_unfiltered (gdb_stdlog,
6157 "infrun: signal may take us out of "
6158 "single-step range\n");
6160 clear_step_over_info ();
6161 insert_hp_step_resume_breakpoint_at_frame (frame);
6162 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6163 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6164 ecs->event_thread->control.trap_expected = 0;
6169 /* Note: step_resume_breakpoint may be non-NULL. This occures
6170 when either there's a nested signal, or when there's a
6171 pending signal enabled just as the signal handler returns
6172 (leaving the inferior at the step-resume-breakpoint without
6173 actually executing it). Either way continue until the
6174 breakpoint is really hit. */
6176 if (!switch_back_to_stepped_thread (ecs))
6179 fprintf_unfiltered (gdb_stdlog,
6180 "infrun: random signal, keep going\n");
6187 process_event_stop_test (ecs);
6190 /* Come here when we've got some debug event / signal we can explain
6191 (IOW, not a random signal), and test whether it should cause a
6192 stop, or whether we should resume the inferior (transparently).
6193 E.g., could be a breakpoint whose condition evaluates false; we
6194 could be still stepping within the line; etc. */
6197 process_event_stop_test (struct execution_control_state *ecs)
6199 struct symtab_and_line stop_pc_sal;
6200 struct frame_info *frame;
6201 struct gdbarch *gdbarch;
6202 CORE_ADDR jmp_buf_pc;
6203 struct bpstat_what what;
6205 /* Handle cases caused by hitting a breakpoint. */
6207 frame = get_current_frame ();
6208 gdbarch = get_frame_arch (frame);
6210 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6212 if (what.call_dummy)
6214 stop_stack_dummy = what.call_dummy;
6217 /* A few breakpoint types have callbacks associated (e.g.,
6218 bp_jit_event). Run them now. */
6219 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6221 /* If we hit an internal event that triggers symbol changes, the
6222 current frame will be invalidated within bpstat_what (e.g., if we
6223 hit an internal solib event). Re-fetch it. */
6224 frame = get_current_frame ();
6225 gdbarch = get_frame_arch (frame);
6227 switch (what.main_action)
6229 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6230 /* If we hit the breakpoint at longjmp while stepping, we
6231 install a momentary breakpoint at the target of the
6235 fprintf_unfiltered (gdb_stdlog,
6236 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6238 ecs->event_thread->stepping_over_breakpoint = 1;
6240 if (what.is_longjmp)
6242 struct value *arg_value;
6244 /* If we set the longjmp breakpoint via a SystemTap probe,
6245 then use it to extract the arguments. The destination PC
6246 is the third argument to the probe. */
6247 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6250 jmp_buf_pc = value_as_address (arg_value);
6251 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6253 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6254 || !gdbarch_get_longjmp_target (gdbarch,
6255 frame, &jmp_buf_pc))
6258 fprintf_unfiltered (gdb_stdlog,
6259 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6260 "(!gdbarch_get_longjmp_target)\n");
6265 /* Insert a breakpoint at resume address. */
6266 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6269 check_exception_resume (ecs, frame);
6273 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6275 struct frame_info *init_frame;
6277 /* There are several cases to consider.
6279 1. The initiating frame no longer exists. In this case we
6280 must stop, because the exception or longjmp has gone too
6283 2. The initiating frame exists, and is the same as the
6284 current frame. We stop, because the exception or longjmp
6287 3. The initiating frame exists and is different from the
6288 current frame. This means the exception or longjmp has
6289 been caught beneath the initiating frame, so keep going.
6291 4. longjmp breakpoint has been placed just to protect
6292 against stale dummy frames and user is not interested in
6293 stopping around longjmps. */
6296 fprintf_unfiltered (gdb_stdlog,
6297 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6299 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6301 delete_exception_resume_breakpoint (ecs->event_thread);
6303 if (what.is_longjmp)
6305 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6307 if (!frame_id_p (ecs->event_thread->initiating_frame))
6315 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6319 struct frame_id current_id
6320 = get_frame_id (get_current_frame ());
6321 if (frame_id_eq (current_id,
6322 ecs->event_thread->initiating_frame))
6324 /* Case 2. Fall through. */
6334 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6336 delete_step_resume_breakpoint (ecs->event_thread);
6338 end_stepping_range (ecs);
6342 case BPSTAT_WHAT_SINGLE:
6344 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6345 ecs->event_thread->stepping_over_breakpoint = 1;
6346 /* Still need to check other stuff, at least the case where we
6347 are stepping and step out of the right range. */
6350 case BPSTAT_WHAT_STEP_RESUME:
6352 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6354 delete_step_resume_breakpoint (ecs->event_thread);
6355 if (ecs->event_thread->control.proceed_to_finish
6356 && execution_direction == EXEC_REVERSE)
6358 struct thread_info *tp = ecs->event_thread;
6360 /* We are finishing a function in reverse, and just hit the
6361 step-resume breakpoint at the start address of the
6362 function, and we're almost there -- just need to back up
6363 by one more single-step, which should take us back to the
6365 tp->control.step_range_start = tp->control.step_range_end = 1;
6369 fill_in_stop_func (gdbarch, ecs);
6370 if (stop_pc == ecs->stop_func_start
6371 && execution_direction == EXEC_REVERSE)
6373 /* We are stepping over a function call in reverse, and just
6374 hit the step-resume breakpoint at the start address of
6375 the function. Go back to single-stepping, which should
6376 take us back to the function call. */
6377 ecs->event_thread->stepping_over_breakpoint = 1;
6383 case BPSTAT_WHAT_STOP_NOISY:
6385 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6386 stop_print_frame = 1;
6388 /* Assume the thread stopped for a breapoint. We'll still check
6389 whether a/the breakpoint is there when the thread is next
6391 ecs->event_thread->stepping_over_breakpoint = 1;
6396 case BPSTAT_WHAT_STOP_SILENT:
6398 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6399 stop_print_frame = 0;
6401 /* Assume the thread stopped for a breapoint. We'll still check
6402 whether a/the breakpoint is there when the thread is next
6404 ecs->event_thread->stepping_over_breakpoint = 1;
6408 case BPSTAT_WHAT_HP_STEP_RESUME:
6410 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6412 delete_step_resume_breakpoint (ecs->event_thread);
6413 if (ecs->event_thread->step_after_step_resume_breakpoint)
6415 /* Back when the step-resume breakpoint was inserted, we
6416 were trying to single-step off a breakpoint. Go back to
6418 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6419 ecs->event_thread->stepping_over_breakpoint = 1;
6425 case BPSTAT_WHAT_KEEP_CHECKING:
6429 /* If we stepped a permanent breakpoint and we had a high priority
6430 step-resume breakpoint for the address we stepped, but we didn't
6431 hit it, then we must have stepped into the signal handler. The
6432 step-resume was only necessary to catch the case of _not_
6433 stepping into the handler, so delete it, and fall through to
6434 checking whether the step finished. */
6435 if (ecs->event_thread->stepped_breakpoint)
6437 struct breakpoint *sr_bp
6438 = ecs->event_thread->control.step_resume_breakpoint;
6441 && sr_bp->loc->permanent
6442 && sr_bp->type == bp_hp_step_resume
6443 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6446 fprintf_unfiltered (gdb_stdlog,
6447 "infrun: stepped permanent breakpoint, stopped in "
6449 delete_step_resume_breakpoint (ecs->event_thread);
6450 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6454 /* We come here if we hit a breakpoint but should not stop for it.
6455 Possibly we also were stepping and should stop for that. So fall
6456 through and test for stepping. But, if not stepping, do not
6459 /* In all-stop mode, if we're currently stepping but have stopped in
6460 some other thread, we need to switch back to the stepped thread. */
6461 if (switch_back_to_stepped_thread (ecs))
6464 if (ecs->event_thread->control.step_resume_breakpoint)
6467 fprintf_unfiltered (gdb_stdlog,
6468 "infrun: step-resume breakpoint is inserted\n");
6470 /* Having a step-resume breakpoint overrides anything
6471 else having to do with stepping commands until
6472 that breakpoint is reached. */
6477 if (ecs->event_thread->control.step_range_end == 0)
6480 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6481 /* Likewise if we aren't even stepping. */
6486 /* Re-fetch current thread's frame in case the code above caused
6487 the frame cache to be re-initialized, making our FRAME variable
6488 a dangling pointer. */
6489 frame = get_current_frame ();
6490 gdbarch = get_frame_arch (frame);
6491 fill_in_stop_func (gdbarch, ecs);
6493 /* If stepping through a line, keep going if still within it.
6495 Note that step_range_end is the address of the first instruction
6496 beyond the step range, and NOT the address of the last instruction
6499 Note also that during reverse execution, we may be stepping
6500 through a function epilogue and therefore must detect when
6501 the current-frame changes in the middle of a line. */
6503 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6504 && (execution_direction != EXEC_REVERSE
6505 || frame_id_eq (get_frame_id (frame),
6506 ecs->event_thread->control.step_frame_id)))
6510 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6511 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6512 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6514 /* Tentatively re-enable range stepping; `resume' disables it if
6515 necessary (e.g., if we're stepping over a breakpoint or we
6516 have software watchpoints). */
6517 ecs->event_thread->control.may_range_step = 1;
6519 /* When stepping backward, stop at beginning of line range
6520 (unless it's the function entry point, in which case
6521 keep going back to the call point). */
6522 if (stop_pc == ecs->event_thread->control.step_range_start
6523 && stop_pc != ecs->stop_func_start
6524 && execution_direction == EXEC_REVERSE)
6525 end_stepping_range (ecs);
6532 /* We stepped out of the stepping range. */
6534 /* If we are stepping at the source level and entered the runtime
6535 loader dynamic symbol resolution code...
6537 EXEC_FORWARD: we keep on single stepping until we exit the run
6538 time loader code and reach the callee's address.
6540 EXEC_REVERSE: we've already executed the callee (backward), and
6541 the runtime loader code is handled just like any other
6542 undebuggable function call. Now we need only keep stepping
6543 backward through the trampoline code, and that's handled further
6544 down, so there is nothing for us to do here. */
6546 if (execution_direction != EXEC_REVERSE
6547 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6548 && in_solib_dynsym_resolve_code (stop_pc))
6550 CORE_ADDR pc_after_resolver =
6551 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6554 fprintf_unfiltered (gdb_stdlog,
6555 "infrun: stepped into dynsym resolve code\n");
6557 if (pc_after_resolver)
6559 /* Set up a step-resume breakpoint at the address
6560 indicated by SKIP_SOLIB_RESOLVER. */
6561 struct symtab_and_line sr_sal;
6564 sr_sal.pc = pc_after_resolver;
6565 sr_sal.pspace = get_frame_program_space (frame);
6567 insert_step_resume_breakpoint_at_sal (gdbarch,
6568 sr_sal, null_frame_id);
6575 if (ecs->event_thread->control.step_range_end != 1
6576 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6577 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6578 && get_frame_type (frame) == SIGTRAMP_FRAME)
6581 fprintf_unfiltered (gdb_stdlog,
6582 "infrun: stepped into signal trampoline\n");
6583 /* The inferior, while doing a "step" or "next", has ended up in
6584 a signal trampoline (either by a signal being delivered or by
6585 the signal handler returning). Just single-step until the
6586 inferior leaves the trampoline (either by calling the handler
6592 /* If we're in the return path from a shared library trampoline,
6593 we want to proceed through the trampoline when stepping. */
6594 /* macro/2012-04-25: This needs to come before the subroutine
6595 call check below as on some targets return trampolines look
6596 like subroutine calls (MIPS16 return thunks). */
6597 if (gdbarch_in_solib_return_trampoline (gdbarch,
6598 stop_pc, ecs->stop_func_name)
6599 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6601 /* Determine where this trampoline returns. */
6602 CORE_ADDR real_stop_pc;
6604 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6607 fprintf_unfiltered (gdb_stdlog,
6608 "infrun: stepped into solib return tramp\n");
6610 /* Only proceed through if we know where it's going. */
6613 /* And put the step-breakpoint there and go until there. */
6614 struct symtab_and_line sr_sal;
6616 init_sal (&sr_sal); /* initialize to zeroes */
6617 sr_sal.pc = real_stop_pc;
6618 sr_sal.section = find_pc_overlay (sr_sal.pc);
6619 sr_sal.pspace = get_frame_program_space (frame);
6621 /* Do not specify what the fp should be when we stop since
6622 on some machines the prologue is where the new fp value
6624 insert_step_resume_breakpoint_at_sal (gdbarch,
6625 sr_sal, null_frame_id);
6627 /* Restart without fiddling with the step ranges or
6634 /* Check for subroutine calls. The check for the current frame
6635 equalling the step ID is not necessary - the check of the
6636 previous frame's ID is sufficient - but it is a common case and
6637 cheaper than checking the previous frame's ID.
6639 NOTE: frame_id_eq will never report two invalid frame IDs as
6640 being equal, so to get into this block, both the current and
6641 previous frame must have valid frame IDs. */
6642 /* The outer_frame_id check is a heuristic to detect stepping
6643 through startup code. If we step over an instruction which
6644 sets the stack pointer from an invalid value to a valid value,
6645 we may detect that as a subroutine call from the mythical
6646 "outermost" function. This could be fixed by marking
6647 outermost frames as !stack_p,code_p,special_p. Then the
6648 initial outermost frame, before sp was valid, would
6649 have code_addr == &_start. See the comment in frame_id_eq
6651 if (!frame_id_eq (get_stack_frame_id (frame),
6652 ecs->event_thread->control.step_stack_frame_id)
6653 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6654 ecs->event_thread->control.step_stack_frame_id)
6655 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6657 || (ecs->event_thread->control.step_start_function
6658 != find_pc_function (stop_pc)))))
6660 CORE_ADDR real_stop_pc;
6663 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6665 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6667 /* I presume that step_over_calls is only 0 when we're
6668 supposed to be stepping at the assembly language level
6669 ("stepi"). Just stop. */
6670 /* And this works the same backward as frontward. MVS */
6671 end_stepping_range (ecs);
6675 /* Reverse stepping through solib trampolines. */
6677 if (execution_direction == EXEC_REVERSE
6678 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6679 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6680 || (ecs->stop_func_start == 0
6681 && in_solib_dynsym_resolve_code (stop_pc))))
6683 /* Any solib trampoline code can be handled in reverse
6684 by simply continuing to single-step. We have already
6685 executed the solib function (backwards), and a few
6686 steps will take us back through the trampoline to the
6692 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6694 /* We're doing a "next".
6696 Normal (forward) execution: set a breakpoint at the
6697 callee's return address (the address at which the caller
6700 Reverse (backward) execution. set the step-resume
6701 breakpoint at the start of the function that we just
6702 stepped into (backwards), and continue to there. When we
6703 get there, we'll need to single-step back to the caller. */
6705 if (execution_direction == EXEC_REVERSE)
6707 /* If we're already at the start of the function, we've either
6708 just stepped backward into a single instruction function,
6709 or stepped back out of a signal handler to the first instruction
6710 of the function. Just keep going, which will single-step back
6712 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6714 struct symtab_and_line sr_sal;
6716 /* Normal function call return (static or dynamic). */
6718 sr_sal.pc = ecs->stop_func_start;
6719 sr_sal.pspace = get_frame_program_space (frame);
6720 insert_step_resume_breakpoint_at_sal (gdbarch,
6721 sr_sal, null_frame_id);
6725 insert_step_resume_breakpoint_at_caller (frame);
6731 /* If we are in a function call trampoline (a stub between the
6732 calling routine and the real function), locate the real
6733 function. That's what tells us (a) whether we want to step
6734 into it at all, and (b) what prologue we want to run to the
6735 end of, if we do step into it. */
6736 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6737 if (real_stop_pc == 0)
6738 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6739 if (real_stop_pc != 0)
6740 ecs->stop_func_start = real_stop_pc;
6742 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6744 struct symtab_and_line sr_sal;
6747 sr_sal.pc = ecs->stop_func_start;
6748 sr_sal.pspace = get_frame_program_space (frame);
6750 insert_step_resume_breakpoint_at_sal (gdbarch,
6751 sr_sal, null_frame_id);
6756 /* If we have line number information for the function we are
6757 thinking of stepping into and the function isn't on the skip
6760 If there are several symtabs at that PC (e.g. with include
6761 files), just want to know whether *any* of them have line
6762 numbers. find_pc_line handles this. */
6764 struct symtab_and_line tmp_sal;
6766 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6767 if (tmp_sal.line != 0
6768 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6771 if (execution_direction == EXEC_REVERSE)
6772 handle_step_into_function_backward (gdbarch, ecs);
6774 handle_step_into_function (gdbarch, ecs);
6779 /* If we have no line number and the step-stop-if-no-debug is
6780 set, we stop the step so that the user has a chance to switch
6781 in assembly mode. */
6782 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6783 && step_stop_if_no_debug)
6785 end_stepping_range (ecs);
6789 if (execution_direction == EXEC_REVERSE)
6791 /* If we're already at the start of the function, we've either just
6792 stepped backward into a single instruction function without line
6793 number info, or stepped back out of a signal handler to the first
6794 instruction of the function without line number info. Just keep
6795 going, which will single-step back to the caller. */
6796 if (ecs->stop_func_start != stop_pc)
6798 /* Set a breakpoint at callee's start address.
6799 From there we can step once and be back in the caller. */
6800 struct symtab_and_line sr_sal;
6803 sr_sal.pc = ecs->stop_func_start;
6804 sr_sal.pspace = get_frame_program_space (frame);
6805 insert_step_resume_breakpoint_at_sal (gdbarch,
6806 sr_sal, null_frame_id);
6810 /* Set a breakpoint at callee's return address (the address
6811 at which the caller will resume). */
6812 insert_step_resume_breakpoint_at_caller (frame);
6818 /* Reverse stepping through solib trampolines. */
6820 if (execution_direction == EXEC_REVERSE
6821 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6823 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6824 || (ecs->stop_func_start == 0
6825 && in_solib_dynsym_resolve_code (stop_pc)))
6827 /* Any solib trampoline code can be handled in reverse
6828 by simply continuing to single-step. We have already
6829 executed the solib function (backwards), and a few
6830 steps will take us back through the trampoline to the
6835 else if (in_solib_dynsym_resolve_code (stop_pc))
6837 /* Stepped backward into the solib dynsym resolver.
6838 Set a breakpoint at its start and continue, then
6839 one more step will take us out. */
6840 struct symtab_and_line sr_sal;
6843 sr_sal.pc = ecs->stop_func_start;
6844 sr_sal.pspace = get_frame_program_space (frame);
6845 insert_step_resume_breakpoint_at_sal (gdbarch,
6846 sr_sal, null_frame_id);
6852 stop_pc_sal = find_pc_line (stop_pc, 0);
6854 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6855 the trampoline processing logic, however, there are some trampolines
6856 that have no names, so we should do trampoline handling first. */
6857 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6858 && ecs->stop_func_name == NULL
6859 && stop_pc_sal.line == 0)
6862 fprintf_unfiltered (gdb_stdlog,
6863 "infrun: stepped into undebuggable function\n");
6865 /* The inferior just stepped into, or returned to, an
6866 undebuggable function (where there is no debugging information
6867 and no line number corresponding to the address where the
6868 inferior stopped). Since we want to skip this kind of code,
6869 we keep going until the inferior returns from this
6870 function - unless the user has asked us not to (via
6871 set step-mode) or we no longer know how to get back
6872 to the call site. */
6873 if (step_stop_if_no_debug
6874 || !frame_id_p (frame_unwind_caller_id (frame)))
6876 /* If we have no line number and the step-stop-if-no-debug
6877 is set, we stop the step so that the user has a chance to
6878 switch in assembly mode. */
6879 end_stepping_range (ecs);
6884 /* Set a breakpoint at callee's return address (the address
6885 at which the caller will resume). */
6886 insert_step_resume_breakpoint_at_caller (frame);
6892 if (ecs->event_thread->control.step_range_end == 1)
6894 /* It is stepi or nexti. We always want to stop stepping after
6897 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6898 end_stepping_range (ecs);
6902 if (stop_pc_sal.line == 0)
6904 /* We have no line number information. That means to stop
6905 stepping (does this always happen right after one instruction,
6906 when we do "s" in a function with no line numbers,
6907 or can this happen as a result of a return or longjmp?). */
6909 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6910 end_stepping_range (ecs);
6914 /* Look for "calls" to inlined functions, part one. If the inline
6915 frame machinery detected some skipped call sites, we have entered
6916 a new inline function. */
6918 if (frame_id_eq (get_frame_id (get_current_frame ()),
6919 ecs->event_thread->control.step_frame_id)
6920 && inline_skipped_frames (ecs->ptid))
6922 struct symtab_and_line call_sal;
6925 fprintf_unfiltered (gdb_stdlog,
6926 "infrun: stepped into inlined function\n");
6928 find_frame_sal (get_current_frame (), &call_sal);
6930 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6932 /* For "step", we're going to stop. But if the call site
6933 for this inlined function is on the same source line as
6934 we were previously stepping, go down into the function
6935 first. Otherwise stop at the call site. */
6937 if (call_sal.line == ecs->event_thread->current_line
6938 && call_sal.symtab == ecs->event_thread->current_symtab)
6939 step_into_inline_frame (ecs->ptid);
6941 end_stepping_range (ecs);
6946 /* For "next", we should stop at the call site if it is on a
6947 different source line. Otherwise continue through the
6948 inlined function. */
6949 if (call_sal.line == ecs->event_thread->current_line
6950 && call_sal.symtab == ecs->event_thread->current_symtab)
6953 end_stepping_range (ecs);
6958 /* Look for "calls" to inlined functions, part two. If we are still
6959 in the same real function we were stepping through, but we have
6960 to go further up to find the exact frame ID, we are stepping
6961 through a more inlined call beyond its call site. */
6963 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6964 && !frame_id_eq (get_frame_id (get_current_frame ()),
6965 ecs->event_thread->control.step_frame_id)
6966 && stepped_in_from (get_current_frame (),
6967 ecs->event_thread->control.step_frame_id))
6970 fprintf_unfiltered (gdb_stdlog,
6971 "infrun: stepping through inlined function\n");
6973 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6976 end_stepping_range (ecs);
6980 if ((stop_pc == stop_pc_sal.pc)
6981 && (ecs->event_thread->current_line != stop_pc_sal.line
6982 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6984 /* We are at the start of a different line. So stop. Note that
6985 we don't stop if we step into the middle of a different line.
6986 That is said to make things like for (;;) statements work
6989 fprintf_unfiltered (gdb_stdlog,
6990 "infrun: stepped to a different line\n");
6991 end_stepping_range (ecs);
6995 /* We aren't done stepping.
6997 Optimize by setting the stepping range to the line.
6998 (We might not be in the original line, but if we entered a
6999 new line in mid-statement, we continue stepping. This makes
7000 things like for(;;) statements work better.) */
7002 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
7003 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
7004 ecs->event_thread->control.may_range_step = 1;
7005 set_step_info (frame, stop_pc_sal);
7008 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
7012 /* In all-stop mode, if we're currently stepping but have stopped in
7013 some other thread, we may need to switch back to the stepped
7014 thread. Returns true we set the inferior running, false if we left
7015 it stopped (and the event needs further processing). */
7018 switch_back_to_stepped_thread (struct execution_control_state *ecs)
7020 if (!target_is_non_stop_p ())
7022 struct thread_info *tp;
7023 struct thread_info *stepping_thread;
7025 /* If any thread is blocked on some internal breakpoint, and we
7026 simply need to step over that breakpoint to get it going
7027 again, do that first. */
7029 /* However, if we see an event for the stepping thread, then we
7030 know all other threads have been moved past their breakpoints
7031 already. Let the caller check whether the step is finished,
7032 etc., before deciding to move it past a breakpoint. */
7033 if (ecs->event_thread->control.step_range_end != 0)
7036 /* Check if the current thread is blocked on an incomplete
7037 step-over, interrupted by a random signal. */
7038 if (ecs->event_thread->control.trap_expected
7039 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7043 fprintf_unfiltered (gdb_stdlog,
7044 "infrun: need to finish step-over of [%s]\n",
7045 target_pid_to_str (ecs->event_thread->ptid));
7051 /* Check if the current thread is blocked by a single-step
7052 breakpoint of another thread. */
7053 if (ecs->hit_singlestep_breakpoint)
7057 fprintf_unfiltered (gdb_stdlog,
7058 "infrun: need to step [%s] over single-step "
7060 target_pid_to_str (ecs->ptid));
7066 /* If this thread needs yet another step-over (e.g., stepping
7067 through a delay slot), do it first before moving on to
7069 if (thread_still_needs_step_over (ecs->event_thread))
7073 fprintf_unfiltered (gdb_stdlog,
7074 "infrun: thread [%s] still needs step-over\n",
7075 target_pid_to_str (ecs->event_thread->ptid));
7081 /* If scheduler locking applies even if not stepping, there's no
7082 need to walk over threads. Above we've checked whether the
7083 current thread is stepping. If some other thread not the
7084 event thread is stepping, then it must be that scheduler
7085 locking is not in effect. */
7086 if (schedlock_applies (ecs->event_thread))
7089 /* Otherwise, we no longer expect a trap in the current thread.
7090 Clear the trap_expected flag before switching back -- this is
7091 what keep_going does as well, if we call it. */
7092 ecs->event_thread->control.trap_expected = 0;
7094 /* Likewise, clear the signal if it should not be passed. */
7095 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7096 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7098 /* Do all pending step-overs before actually proceeding with
7100 if (start_step_over ())
7102 prepare_to_wait (ecs);
7106 /* Look for the stepping/nexting thread. */
7107 stepping_thread = NULL;
7109 ALL_NON_EXITED_THREADS (tp)
7111 /* Ignore threads of processes the caller is not
7114 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
7117 /* When stepping over a breakpoint, we lock all threads
7118 except the one that needs to move past the breakpoint.
7119 If a non-event thread has this set, the "incomplete
7120 step-over" check above should have caught it earlier. */
7121 if (tp->control.trap_expected)
7123 internal_error (__FILE__, __LINE__,
7124 "[%s] has inconsistent state: "
7125 "trap_expected=%d\n",
7126 target_pid_to_str (tp->ptid),
7127 tp->control.trap_expected);
7130 /* Did we find the stepping thread? */
7131 if (tp->control.step_range_end)
7133 /* Yep. There should only one though. */
7134 gdb_assert (stepping_thread == NULL);
7136 /* The event thread is handled at the top, before we
7138 gdb_assert (tp != ecs->event_thread);
7140 /* If some thread other than the event thread is
7141 stepping, then scheduler locking can't be in effect,
7142 otherwise we wouldn't have resumed the current event
7143 thread in the first place. */
7144 gdb_assert (!schedlock_applies (tp));
7146 stepping_thread = tp;
7150 if (stepping_thread != NULL)
7153 fprintf_unfiltered (gdb_stdlog,
7154 "infrun: switching back to stepped thread\n");
7156 if (keep_going_stepped_thread (stepping_thread))
7158 prepare_to_wait (ecs);
7167 /* Set a previously stepped thread back to stepping. Returns true on
7168 success, false if the resume is not possible (e.g., the thread
7172 keep_going_stepped_thread (struct thread_info *tp)
7174 struct frame_info *frame;
7175 struct execution_control_state ecss;
7176 struct execution_control_state *ecs = &ecss;
7178 /* If the stepping thread exited, then don't try to switch back and
7179 resume it, which could fail in several different ways depending
7180 on the target. Instead, just keep going.
7182 We can find a stepping dead thread in the thread list in two
7185 - The target supports thread exit events, and when the target
7186 tries to delete the thread from the thread list, inferior_ptid
7187 pointed at the exiting thread. In such case, calling
7188 delete_thread does not really remove the thread from the list;
7189 instead, the thread is left listed, with 'exited' state.
7191 - The target's debug interface does not support thread exit
7192 events, and so we have no idea whatsoever if the previously
7193 stepping thread is still alive. For that reason, we need to
7194 synchronously query the target now. */
7196 if (is_exited (tp->ptid)
7197 || !target_thread_alive (tp->ptid))
7200 fprintf_unfiltered (gdb_stdlog,
7201 "infrun: not resuming previously "
7202 "stepped thread, it has vanished\n");
7204 delete_thread (tp->ptid);
7209 fprintf_unfiltered (gdb_stdlog,
7210 "infrun: resuming previously stepped thread\n");
7212 reset_ecs (ecs, tp);
7213 switch_to_thread (tp->ptid);
7215 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7216 frame = get_current_frame ();
7218 /* If the PC of the thread we were trying to single-step has
7219 changed, then that thread has trapped or been signaled, but the
7220 event has not been reported to GDB yet. Re-poll the target
7221 looking for this particular thread's event (i.e. temporarily
7222 enable schedlock) by:
7224 - setting a break at the current PC
7225 - resuming that particular thread, only (by setting trap
7228 This prevents us continuously moving the single-step breakpoint
7229 forward, one instruction at a time, overstepping. */
7231 if (stop_pc != tp->prev_pc)
7236 fprintf_unfiltered (gdb_stdlog,
7237 "infrun: expected thread advanced also (%s -> %s)\n",
7238 paddress (target_gdbarch (), tp->prev_pc),
7239 paddress (target_gdbarch (), stop_pc));
7241 /* Clear the info of the previous step-over, as it's no longer
7242 valid (if the thread was trying to step over a breakpoint, it
7243 has already succeeded). It's what keep_going would do too,
7244 if we called it. Do this before trying to insert the sss
7245 breakpoint, otherwise if we were previously trying to step
7246 over this exact address in another thread, the breakpoint is
7248 clear_step_over_info ();
7249 tp->control.trap_expected = 0;
7251 insert_single_step_breakpoint (get_frame_arch (frame),
7252 get_frame_address_space (frame),
7256 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7257 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7262 fprintf_unfiltered (gdb_stdlog,
7263 "infrun: expected thread still hasn't advanced\n");
7265 keep_going_pass_signal (ecs);
7270 /* Is thread TP in the middle of (software or hardware)
7271 single-stepping? (Note the result of this function must never be
7272 passed directly as target_resume's STEP parameter.) */
7275 currently_stepping (struct thread_info *tp)
7277 return ((tp->control.step_range_end
7278 && tp->control.step_resume_breakpoint == NULL)
7279 || tp->control.trap_expected
7280 || tp->stepped_breakpoint
7281 || bpstat_should_step ());
7284 /* Inferior has stepped into a subroutine call with source code that
7285 we should not step over. Do step to the first line of code in
7289 handle_step_into_function (struct gdbarch *gdbarch,
7290 struct execution_control_state *ecs)
7292 struct compunit_symtab *cust;
7293 struct symtab_and_line stop_func_sal, sr_sal;
7295 fill_in_stop_func (gdbarch, ecs);
7297 cust = find_pc_compunit_symtab (stop_pc);
7298 if (cust != NULL && compunit_language (cust) != language_asm)
7299 ecs->stop_func_start
7300 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7302 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7303 /* Use the step_resume_break to step until the end of the prologue,
7304 even if that involves jumps (as it seems to on the vax under
7306 /* If the prologue ends in the middle of a source line, continue to
7307 the end of that source line (if it is still within the function).
7308 Otherwise, just go to end of prologue. */
7309 if (stop_func_sal.end
7310 && stop_func_sal.pc != ecs->stop_func_start
7311 && stop_func_sal.end < ecs->stop_func_end)
7312 ecs->stop_func_start = stop_func_sal.end;
7314 /* Architectures which require breakpoint adjustment might not be able
7315 to place a breakpoint at the computed address. If so, the test
7316 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7317 ecs->stop_func_start to an address at which a breakpoint may be
7318 legitimately placed.
7320 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7321 made, GDB will enter an infinite loop when stepping through
7322 optimized code consisting of VLIW instructions which contain
7323 subinstructions corresponding to different source lines. On
7324 FR-V, it's not permitted to place a breakpoint on any but the
7325 first subinstruction of a VLIW instruction. When a breakpoint is
7326 set, GDB will adjust the breakpoint address to the beginning of
7327 the VLIW instruction. Thus, we need to make the corresponding
7328 adjustment here when computing the stop address. */
7330 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7332 ecs->stop_func_start
7333 = gdbarch_adjust_breakpoint_address (gdbarch,
7334 ecs->stop_func_start);
7337 if (ecs->stop_func_start == stop_pc)
7339 /* We are already there: stop now. */
7340 end_stepping_range (ecs);
7345 /* Put the step-breakpoint there and go until there. */
7346 init_sal (&sr_sal); /* initialize to zeroes */
7347 sr_sal.pc = ecs->stop_func_start;
7348 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7349 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7351 /* Do not specify what the fp should be when we stop since on
7352 some machines the prologue is where the new fp value is
7354 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7356 /* And make sure stepping stops right away then. */
7357 ecs->event_thread->control.step_range_end
7358 = ecs->event_thread->control.step_range_start;
7363 /* Inferior has stepped backward into a subroutine call with source
7364 code that we should not step over. Do step to the beginning of the
7365 last line of code in it. */
7368 handle_step_into_function_backward (struct gdbarch *gdbarch,
7369 struct execution_control_state *ecs)
7371 struct compunit_symtab *cust;
7372 struct symtab_and_line stop_func_sal;
7374 fill_in_stop_func (gdbarch, ecs);
7376 cust = find_pc_compunit_symtab (stop_pc);
7377 if (cust != NULL && compunit_language (cust) != language_asm)
7378 ecs->stop_func_start
7379 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7381 stop_func_sal = find_pc_line (stop_pc, 0);
7383 /* OK, we're just going to keep stepping here. */
7384 if (stop_func_sal.pc == stop_pc)
7386 /* We're there already. Just stop stepping now. */
7387 end_stepping_range (ecs);
7391 /* Else just reset the step range and keep going.
7392 No step-resume breakpoint, they don't work for
7393 epilogues, which can have multiple entry paths. */
7394 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7395 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7401 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7402 This is used to both functions and to skip over code. */
7405 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7406 struct symtab_and_line sr_sal,
7407 struct frame_id sr_id,
7408 enum bptype sr_type)
7410 /* There should never be more than one step-resume or longjmp-resume
7411 breakpoint per thread, so we should never be setting a new
7412 step_resume_breakpoint when one is already active. */
7413 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7414 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7417 fprintf_unfiltered (gdb_stdlog,
7418 "infrun: inserting step-resume breakpoint at %s\n",
7419 paddress (gdbarch, sr_sal.pc));
7421 inferior_thread ()->control.step_resume_breakpoint
7422 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7426 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7427 struct symtab_and_line sr_sal,
7428 struct frame_id sr_id)
7430 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7435 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7436 This is used to skip a potential signal handler.
7438 This is called with the interrupted function's frame. The signal
7439 handler, when it returns, will resume the interrupted function at
7443 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7445 struct symtab_and_line sr_sal;
7446 struct gdbarch *gdbarch;
7448 gdb_assert (return_frame != NULL);
7449 init_sal (&sr_sal); /* initialize to zeros */
7451 gdbarch = get_frame_arch (return_frame);
7452 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7453 sr_sal.section = find_pc_overlay (sr_sal.pc);
7454 sr_sal.pspace = get_frame_program_space (return_frame);
7456 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7457 get_stack_frame_id (return_frame),
7461 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7462 is used to skip a function after stepping into it (for "next" or if
7463 the called function has no debugging information).
7465 The current function has almost always been reached by single
7466 stepping a call or return instruction. NEXT_FRAME belongs to the
7467 current function, and the breakpoint will be set at the caller's
7470 This is a separate function rather than reusing
7471 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7472 get_prev_frame, which may stop prematurely (see the implementation
7473 of frame_unwind_caller_id for an example). */
7476 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7478 struct symtab_and_line sr_sal;
7479 struct gdbarch *gdbarch;
7481 /* We shouldn't have gotten here if we don't know where the call site
7483 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7485 init_sal (&sr_sal); /* initialize to zeros */
7487 gdbarch = frame_unwind_caller_arch (next_frame);
7488 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7489 frame_unwind_caller_pc (next_frame));
7490 sr_sal.section = find_pc_overlay (sr_sal.pc);
7491 sr_sal.pspace = frame_unwind_program_space (next_frame);
7493 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7494 frame_unwind_caller_id (next_frame));
7497 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7498 new breakpoint at the target of a jmp_buf. The handling of
7499 longjmp-resume uses the same mechanisms used for handling
7500 "step-resume" breakpoints. */
7503 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7505 /* There should never be more than one longjmp-resume breakpoint per
7506 thread, so we should never be setting a new
7507 longjmp_resume_breakpoint when one is already active. */
7508 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7511 fprintf_unfiltered (gdb_stdlog,
7512 "infrun: inserting longjmp-resume breakpoint at %s\n",
7513 paddress (gdbarch, pc));
7515 inferior_thread ()->control.exception_resume_breakpoint =
7516 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7519 /* Insert an exception resume breakpoint. TP is the thread throwing
7520 the exception. The block B is the block of the unwinder debug hook
7521 function. FRAME is the frame corresponding to the call to this
7522 function. SYM is the symbol of the function argument holding the
7523 target PC of the exception. */
7526 insert_exception_resume_breakpoint (struct thread_info *tp,
7527 const struct block *b,
7528 struct frame_info *frame,
7533 struct block_symbol vsym;
7534 struct value *value;
7536 struct breakpoint *bp;
7538 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7539 value = read_var_value (vsym.symbol, vsym.block, frame);
7540 /* If the value was optimized out, revert to the old behavior. */
7541 if (! value_optimized_out (value))
7543 handler = value_as_address (value);
7546 fprintf_unfiltered (gdb_stdlog,
7547 "infrun: exception resume at %lx\n",
7548 (unsigned long) handler);
7550 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7551 handler, bp_exception_resume);
7553 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7556 bp->thread = tp->global_num;
7557 inferior_thread ()->control.exception_resume_breakpoint = bp;
7560 CATCH (e, RETURN_MASK_ERROR)
7562 /* We want to ignore errors here. */
7567 /* A helper for check_exception_resume that sets an
7568 exception-breakpoint based on a SystemTap probe. */
7571 insert_exception_resume_from_probe (struct thread_info *tp,
7572 const struct bound_probe *probe,
7573 struct frame_info *frame)
7575 struct value *arg_value;
7577 struct breakpoint *bp;
7579 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7583 handler = value_as_address (arg_value);
7586 fprintf_unfiltered (gdb_stdlog,
7587 "infrun: exception resume at %s\n",
7588 paddress (get_objfile_arch (probe->objfile),
7591 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7592 handler, bp_exception_resume);
7593 bp->thread = tp->global_num;
7594 inferior_thread ()->control.exception_resume_breakpoint = bp;
7597 /* This is called when an exception has been intercepted. Check to
7598 see whether the exception's destination is of interest, and if so,
7599 set an exception resume breakpoint there. */
7602 check_exception_resume (struct execution_control_state *ecs,
7603 struct frame_info *frame)
7605 struct bound_probe probe;
7606 struct symbol *func;
7608 /* First see if this exception unwinding breakpoint was set via a
7609 SystemTap probe point. If so, the probe has two arguments: the
7610 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7611 set a breakpoint there. */
7612 probe = find_probe_by_pc (get_frame_pc (frame));
7615 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7619 func = get_frame_function (frame);
7625 const struct block *b;
7626 struct block_iterator iter;
7630 /* The exception breakpoint is a thread-specific breakpoint on
7631 the unwinder's debug hook, declared as:
7633 void _Unwind_DebugHook (void *cfa, void *handler);
7635 The CFA argument indicates the frame to which control is
7636 about to be transferred. HANDLER is the destination PC.
7638 We ignore the CFA and set a temporary breakpoint at HANDLER.
7639 This is not extremely efficient but it avoids issues in gdb
7640 with computing the DWARF CFA, and it also works even in weird
7641 cases such as throwing an exception from inside a signal
7644 b = SYMBOL_BLOCK_VALUE (func);
7645 ALL_BLOCK_SYMBOLS (b, iter, sym)
7647 if (!SYMBOL_IS_ARGUMENT (sym))
7654 insert_exception_resume_breakpoint (ecs->event_thread,
7660 CATCH (e, RETURN_MASK_ERROR)
7667 stop_waiting (struct execution_control_state *ecs)
7670 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7672 /* Let callers know we don't want to wait for the inferior anymore. */
7673 ecs->wait_some_more = 0;
7675 /* If all-stop, but the target is always in non-stop mode, stop all
7676 threads now that we're presenting the stop to the user. */
7677 if (!non_stop && target_is_non_stop_p ())
7678 stop_all_threads ();
7681 /* Like keep_going, but passes the signal to the inferior, even if the
7682 signal is set to nopass. */
7685 keep_going_pass_signal (struct execution_control_state *ecs)
7687 /* Make sure normal_stop is called if we get a QUIT handled before
7689 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7691 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7692 gdb_assert (!ecs->event_thread->resumed);
7694 /* Save the pc before execution, to compare with pc after stop. */
7695 ecs->event_thread->prev_pc
7696 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7698 if (ecs->event_thread->control.trap_expected)
7700 struct thread_info *tp = ecs->event_thread;
7703 fprintf_unfiltered (gdb_stdlog,
7704 "infrun: %s has trap_expected set, "
7705 "resuming to collect trap\n",
7706 target_pid_to_str (tp->ptid));
7708 /* We haven't yet gotten our trap, and either: intercepted a
7709 non-signal event (e.g., a fork); or took a signal which we
7710 are supposed to pass through to the inferior. Simply
7712 discard_cleanups (old_cleanups);
7713 resume (ecs->event_thread->suspend.stop_signal);
7715 else if (step_over_info_valid_p ())
7717 /* Another thread is stepping over a breakpoint in-line. If
7718 this thread needs a step-over too, queue the request. In
7719 either case, this resume must be deferred for later. */
7720 struct thread_info *tp = ecs->event_thread;
7722 if (ecs->hit_singlestep_breakpoint
7723 || thread_still_needs_step_over (tp))
7726 fprintf_unfiltered (gdb_stdlog,
7727 "infrun: step-over already in progress: "
7728 "step-over for %s deferred\n",
7729 target_pid_to_str (tp->ptid));
7730 thread_step_over_chain_enqueue (tp);
7735 fprintf_unfiltered (gdb_stdlog,
7736 "infrun: step-over in progress: "
7737 "resume of %s deferred\n",
7738 target_pid_to_str (tp->ptid));
7741 discard_cleanups (old_cleanups);
7745 struct regcache *regcache = get_current_regcache ();
7748 step_over_what step_what;
7750 /* Either the trap was not expected, but we are continuing
7751 anyway (if we got a signal, the user asked it be passed to
7754 We got our expected trap, but decided we should resume from
7757 We're going to run this baby now!
7759 Note that insert_breakpoints won't try to re-insert
7760 already inserted breakpoints. Therefore, we don't
7761 care if breakpoints were already inserted, or not. */
7763 /* If we need to step over a breakpoint, and we're not using
7764 displaced stepping to do so, insert all breakpoints
7765 (watchpoints, etc.) but the one we're stepping over, step one
7766 instruction, and then re-insert the breakpoint when that step
7769 step_what = thread_still_needs_step_over (ecs->event_thread);
7771 remove_bp = (ecs->hit_singlestep_breakpoint
7772 || (step_what & STEP_OVER_BREAKPOINT));
7773 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7775 /* We can't use displaced stepping if we need to step past a
7776 watchpoint. The instruction copied to the scratch pad would
7777 still trigger the watchpoint. */
7779 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7781 set_step_over_info (get_regcache_aspace (regcache),
7782 regcache_read_pc (regcache), remove_wps,
7783 ecs->event_thread->global_num);
7785 else if (remove_wps)
7786 set_step_over_info (NULL, 0, remove_wps, -1);
7788 /* If we now need to do an in-line step-over, we need to stop
7789 all other threads. Note this must be done before
7790 insert_breakpoints below, because that removes the breakpoint
7791 we're about to step over, otherwise other threads could miss
7793 if (step_over_info_valid_p () && target_is_non_stop_p ())
7794 stop_all_threads ();
7796 /* Stop stepping if inserting breakpoints fails. */
7799 insert_breakpoints ();
7801 CATCH (e, RETURN_MASK_ERROR)
7803 exception_print (gdb_stderr, e);
7805 discard_cleanups (old_cleanups);
7810 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7812 discard_cleanups (old_cleanups);
7813 resume (ecs->event_thread->suspend.stop_signal);
7816 prepare_to_wait (ecs);
7819 /* Called when we should continue running the inferior, because the
7820 current event doesn't cause a user visible stop. This does the
7821 resuming part; waiting for the next event is done elsewhere. */
7824 keep_going (struct execution_control_state *ecs)
7826 if (ecs->event_thread->control.trap_expected
7827 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7828 ecs->event_thread->control.trap_expected = 0;
7830 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7831 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7832 keep_going_pass_signal (ecs);
7835 /* This function normally comes after a resume, before
7836 handle_inferior_event exits. It takes care of any last bits of
7837 housekeeping, and sets the all-important wait_some_more flag. */
7840 prepare_to_wait (struct execution_control_state *ecs)
7843 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7845 ecs->wait_some_more = 1;
7847 if (!target_is_async_p ())
7848 mark_infrun_async_event_handler ();
7851 /* We are done with the step range of a step/next/si/ni command.
7852 Called once for each n of a "step n" operation. */
7855 end_stepping_range (struct execution_control_state *ecs)
7857 ecs->event_thread->control.stop_step = 1;
7861 /* Several print_*_reason functions to print why the inferior has stopped.
7862 We always print something when the inferior exits, or receives a signal.
7863 The rest of the cases are dealt with later on in normal_stop and
7864 print_it_typical. Ideally there should be a call to one of these
7865 print_*_reason functions functions from handle_inferior_event each time
7866 stop_waiting is called.
7868 Note that we don't call these directly, instead we delegate that to
7869 the interpreters, through observers. Interpreters then call these
7870 with whatever uiout is right. */
7873 print_end_stepping_range_reason (struct ui_out *uiout)
7875 /* For CLI-like interpreters, print nothing. */
7877 if (uiout->is_mi_like_p ())
7879 uiout->field_string ("reason",
7880 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7885 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7887 annotate_signalled ();
7888 if (uiout->is_mi_like_p ())
7890 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7891 uiout->text ("\nProgram terminated with signal ");
7892 annotate_signal_name ();
7893 uiout->field_string ("signal-name",
7894 gdb_signal_to_name (siggnal));
7895 annotate_signal_name_end ();
7897 annotate_signal_string ();
7898 uiout->field_string ("signal-meaning",
7899 gdb_signal_to_string (siggnal));
7900 annotate_signal_string_end ();
7901 uiout->text (".\n");
7902 uiout->text ("The program no longer exists.\n");
7906 print_exited_reason (struct ui_out *uiout, int exitstatus)
7908 struct inferior *inf = current_inferior ();
7909 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7911 annotate_exited (exitstatus);
7914 if (uiout->is_mi_like_p ())
7915 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7916 uiout->text ("[Inferior ");
7917 uiout->text (plongest (inf->num));
7919 uiout->text (pidstr);
7920 uiout->text (") exited with code ");
7921 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7922 uiout->text ("]\n");
7926 if (uiout->is_mi_like_p ())
7928 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7929 uiout->text ("[Inferior ");
7930 uiout->text (plongest (inf->num));
7932 uiout->text (pidstr);
7933 uiout->text (") exited normally]\n");
7937 /* Some targets/architectures can do extra processing/display of
7938 segmentation faults. E.g., Intel MPX boundary faults.
7939 Call the architecture dependent function to handle the fault. */
7942 handle_segmentation_fault (struct ui_out *uiout)
7944 struct regcache *regcache = get_current_regcache ();
7945 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7947 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7948 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7952 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7954 struct thread_info *thr = inferior_thread ();
7958 if (uiout->is_mi_like_p ())
7960 else if (show_thread_that_caused_stop ())
7964 uiout->text ("\nThread ");
7965 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7967 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7970 uiout->text (" \"");
7971 uiout->field_fmt ("name", "%s", name);
7976 uiout->text ("\nProgram");
7978 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7979 uiout->text (" stopped");
7982 uiout->text (" received signal ");
7983 annotate_signal_name ();
7984 if (uiout->is_mi_like_p ())
7986 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7987 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7988 annotate_signal_name_end ();
7990 annotate_signal_string ();
7991 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7993 if (siggnal == GDB_SIGNAL_SEGV)
7994 handle_segmentation_fault (uiout);
7996 annotate_signal_string_end ();
7998 uiout->text (".\n");
8002 print_no_history_reason (struct ui_out *uiout)
8004 uiout->text ("\nNo more reverse-execution history.\n");
8007 /* Print current location without a level number, if we have changed
8008 functions or hit a breakpoint. Print source line if we have one.
8009 bpstat_print contains the logic deciding in detail what to print,
8010 based on the event(s) that just occurred. */
8013 print_stop_location (struct target_waitstatus *ws)
8016 enum print_what source_flag;
8017 int do_frame_printing = 1;
8018 struct thread_info *tp = inferior_thread ();
8020 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
8024 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8025 should) carry around the function and does (or should) use
8026 that when doing a frame comparison. */
8027 if (tp->control.stop_step
8028 && frame_id_eq (tp->control.step_frame_id,
8029 get_frame_id (get_current_frame ()))
8030 && tp->control.step_start_function == find_pc_function (stop_pc))
8032 /* Finished step, just print source line. */
8033 source_flag = SRC_LINE;
8037 /* Print location and source line. */
8038 source_flag = SRC_AND_LOC;
8041 case PRINT_SRC_AND_LOC:
8042 /* Print location and source line. */
8043 source_flag = SRC_AND_LOC;
8045 case PRINT_SRC_ONLY:
8046 source_flag = SRC_LINE;
8049 /* Something bogus. */
8050 source_flag = SRC_LINE;
8051 do_frame_printing = 0;
8054 internal_error (__FILE__, __LINE__, _("Unknown value."));
8057 /* The behavior of this routine with respect to the source
8059 SRC_LINE: Print only source line
8060 LOCATION: Print only location
8061 SRC_AND_LOC: Print location and source line. */
8062 if (do_frame_printing)
8063 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8069 print_stop_event (struct ui_out *uiout)
8071 struct target_waitstatus last;
8073 struct thread_info *tp;
8075 get_last_target_status (&last_ptid, &last);
8078 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8080 print_stop_location (&last);
8082 /* Display the auto-display expressions. */
8086 tp = inferior_thread ();
8087 if (tp->thread_fsm != NULL
8088 && thread_fsm_finished_p (tp->thread_fsm))
8090 struct return_value_info *rv;
8092 rv = thread_fsm_return_value (tp->thread_fsm);
8094 print_return_value (uiout, rv);
8101 maybe_remove_breakpoints (void)
8103 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8105 if (remove_breakpoints ())
8107 target_terminal_ours_for_output ();
8108 printf_filtered (_("Cannot remove breakpoints because "
8109 "program is no longer writable.\nFurther "
8110 "execution is probably impossible.\n"));
8115 /* The execution context that just caused a normal stop. */
8122 /* The event PTID. */
8126 /* If stopp for a thread event, this is the thread that caused the
8128 struct thread_info *thread;
8130 /* The inferior that caused the stop. */
8134 /* Returns a new stop context. If stopped for a thread event, this
8135 takes a strong reference to the thread. */
8137 static struct stop_context *
8138 save_stop_context (void)
8140 struct stop_context *sc = XNEW (struct stop_context);
8142 sc->stop_id = get_stop_id ();
8143 sc->ptid = inferior_ptid;
8144 sc->inf_num = current_inferior ()->num;
8146 if (!ptid_equal (inferior_ptid, null_ptid))
8148 /* Take a strong reference so that the thread can't be deleted
8150 sc->thread = inferior_thread ();
8151 sc->thread->incref ();
8159 /* Release a stop context previously created with save_stop_context.
8160 Releases the strong reference to the thread as well. */
8163 release_stop_context_cleanup (void *arg)
8165 struct stop_context *sc = (struct stop_context *) arg;
8167 if (sc->thread != NULL)
8168 sc->thread->decref ();
8172 /* Return true if the current context no longer matches the saved stop
8176 stop_context_changed (struct stop_context *prev)
8178 if (!ptid_equal (prev->ptid, inferior_ptid))
8180 if (prev->inf_num != current_inferior ()->num)
8182 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8184 if (get_stop_id () != prev->stop_id)
8194 struct target_waitstatus last;
8196 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
8199 get_last_target_status (&last_ptid, &last);
8203 /* If an exception is thrown from this point on, make sure to
8204 propagate GDB's knowledge of the executing state to the
8205 frontend/user running state. A QUIT is an easy exception to see
8206 here, so do this before any filtered output. */
8208 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
8209 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8210 || last.kind == TARGET_WAITKIND_EXITED)
8212 /* On some targets, we may still have live threads in the
8213 inferior when we get a process exit event. E.g., for
8214 "checkpoint", when the current checkpoint/fork exits,
8215 linux-fork.c automatically switches to another fork from
8216 within target_mourn_inferior. */
8217 if (!ptid_equal (inferior_ptid, null_ptid))
8219 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
8220 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
8223 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8224 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
8226 /* As we're presenting a stop, and potentially removing breakpoints,
8227 update the thread list so we can tell whether there are threads
8228 running on the target. With target remote, for example, we can
8229 only learn about new threads when we explicitly update the thread
8230 list. Do this before notifying the interpreters about signal
8231 stops, end of stepping ranges, etc., so that the "new thread"
8232 output is emitted before e.g., "Program received signal FOO",
8233 instead of after. */
8234 update_thread_list ();
8236 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8237 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
8239 /* As with the notification of thread events, we want to delay
8240 notifying the user that we've switched thread context until
8241 the inferior actually stops.
8243 There's no point in saying anything if the inferior has exited.
8244 Note that SIGNALLED here means "exited with a signal", not
8245 "received a signal".
8247 Also skip saying anything in non-stop mode. In that mode, as we
8248 don't want GDB to switch threads behind the user's back, to avoid
8249 races where the user is typing a command to apply to thread x,
8250 but GDB switches to thread y before the user finishes entering
8251 the command, fetch_inferior_event installs a cleanup to restore
8252 the current thread back to the thread the user had selected right
8253 after this event is handled, so we're not really switching, only
8254 informing of a stop. */
8256 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8257 && target_has_execution
8258 && last.kind != TARGET_WAITKIND_SIGNALLED
8259 && last.kind != TARGET_WAITKIND_EXITED
8260 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8262 SWITCH_THRU_ALL_UIS ()
8264 target_terminal_ours_for_output ();
8265 printf_filtered (_("[Switching to %s]\n"),
8266 target_pid_to_str (inferior_ptid));
8267 annotate_thread_changed ();
8269 previous_inferior_ptid = inferior_ptid;
8272 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8274 SWITCH_THRU_ALL_UIS ()
8275 if (current_ui->prompt_state == PROMPT_BLOCKED)
8277 target_terminal_ours_for_output ();
8278 printf_filtered (_("No unwaited-for children left.\n"));
8282 /* Note: this depends on the update_thread_list call above. */
8283 maybe_remove_breakpoints ();
8285 /* If an auto-display called a function and that got a signal,
8286 delete that auto-display to avoid an infinite recursion. */
8288 if (stopped_by_random_signal)
8289 disable_current_display ();
8291 SWITCH_THRU_ALL_UIS ()
8293 async_enable_stdin ();
8296 /* Let the user/frontend see the threads as stopped. */
8297 do_cleanups (old_chain);
8299 /* Select innermost stack frame - i.e., current frame is frame 0,
8300 and current location is based on that. Handle the case where the
8301 dummy call is returning after being stopped. E.g. the dummy call
8302 previously hit a breakpoint. (If the dummy call returns
8303 normally, we won't reach here.) Do this before the stop hook is
8304 run, so that it doesn't get to see the temporary dummy frame,
8305 which is not where we'll present the stop. */
8306 if (has_stack_frames ())
8308 if (stop_stack_dummy == STOP_STACK_DUMMY)
8310 /* Pop the empty frame that contains the stack dummy. This
8311 also restores inferior state prior to the call (struct
8312 infcall_suspend_state). */
8313 struct frame_info *frame = get_current_frame ();
8315 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8317 /* frame_pop calls reinit_frame_cache as the last thing it
8318 does which means there's now no selected frame. */
8321 select_frame (get_current_frame ());
8323 /* Set the current source location. */
8324 set_current_sal_from_frame (get_current_frame ());
8327 /* Look up the hook_stop and run it (CLI internally handles problem
8328 of stop_command's pre-hook not existing). */
8329 if (stop_command != NULL)
8331 struct stop_context *saved_context = save_stop_context ();
8332 struct cleanup *old_chain
8333 = make_cleanup (release_stop_context_cleanup, saved_context);
8335 catch_errors (hook_stop_stub, stop_command,
8336 "Error while running hook_stop:\n", RETURN_MASK_ALL);
8338 /* If the stop hook resumes the target, then there's no point in
8339 trying to notify about the previous stop; its context is
8340 gone. Likewise if the command switches thread or inferior --
8341 the observers would print a stop for the wrong
8343 if (stop_context_changed (saved_context))
8345 do_cleanups (old_chain);
8348 do_cleanups (old_chain);
8351 /* Notify observers about the stop. This is where the interpreters
8352 print the stop event. */
8353 if (!ptid_equal (inferior_ptid, null_ptid))
8354 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8357 observer_notify_normal_stop (NULL, stop_print_frame);
8359 annotate_stopped ();
8361 if (target_has_execution)
8363 if (last.kind != TARGET_WAITKIND_SIGNALLED
8364 && last.kind != TARGET_WAITKIND_EXITED)
8365 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8366 Delete any breakpoint that is to be deleted at the next stop. */
8367 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8370 /* Try to get rid of automatically added inferiors that are no
8371 longer needed. Keeping those around slows down things linearly.
8372 Note that this never removes the current inferior. */
8379 hook_stop_stub (void *cmd)
8381 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
8386 signal_stop_state (int signo)
8388 return signal_stop[signo];
8392 signal_print_state (int signo)
8394 return signal_print[signo];
8398 signal_pass_state (int signo)
8400 return signal_program[signo];
8404 signal_cache_update (int signo)
8408 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8409 signal_cache_update (signo);
8414 signal_pass[signo] = (signal_stop[signo] == 0
8415 && signal_print[signo] == 0
8416 && signal_program[signo] == 1
8417 && signal_catch[signo] == 0);
8421 signal_stop_update (int signo, int state)
8423 int ret = signal_stop[signo];
8425 signal_stop[signo] = state;
8426 signal_cache_update (signo);
8431 signal_print_update (int signo, int state)
8433 int ret = signal_print[signo];
8435 signal_print[signo] = state;
8436 signal_cache_update (signo);
8441 signal_pass_update (int signo, int state)
8443 int ret = signal_program[signo];
8445 signal_program[signo] = state;
8446 signal_cache_update (signo);
8450 /* Update the global 'signal_catch' from INFO and notify the
8454 signal_catch_update (const unsigned int *info)
8458 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8459 signal_catch[i] = info[i] > 0;
8460 signal_cache_update (-1);
8461 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8465 sig_print_header (void)
8467 printf_filtered (_("Signal Stop\tPrint\tPass "
8468 "to program\tDescription\n"));
8472 sig_print_info (enum gdb_signal oursig)
8474 const char *name = gdb_signal_to_name (oursig);
8475 int name_padding = 13 - strlen (name);
8477 if (name_padding <= 0)
8480 printf_filtered ("%s", name);
8481 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8482 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8483 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8484 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8485 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8488 /* Specify how various signals in the inferior should be handled. */
8491 handle_command (char *args, int from_tty)
8493 int digits, wordlen;
8494 int sigfirst, signum, siglast;
8495 enum gdb_signal oursig;
8498 unsigned char *sigs;
8502 error_no_arg (_("signal to handle"));
8505 /* Allocate and zero an array of flags for which signals to handle. */
8507 nsigs = (int) GDB_SIGNAL_LAST;
8508 sigs = (unsigned char *) alloca (nsigs);
8509 memset (sigs, 0, nsigs);
8511 /* Break the command line up into args. */
8513 gdb_argv built_argv (args);
8515 /* Walk through the args, looking for signal oursigs, signal names, and
8516 actions. Signal numbers and signal names may be interspersed with
8517 actions, with the actions being performed for all signals cumulatively
8518 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8520 for (char *arg : built_argv)
8522 wordlen = strlen (arg);
8523 for (digits = 0; isdigit (arg[digits]); digits++)
8527 sigfirst = siglast = -1;
8529 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8531 /* Apply action to all signals except those used by the
8532 debugger. Silently skip those. */
8535 siglast = nsigs - 1;
8537 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8539 SET_SIGS (nsigs, sigs, signal_stop);
8540 SET_SIGS (nsigs, sigs, signal_print);
8542 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8544 UNSET_SIGS (nsigs, sigs, signal_program);
8546 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8548 SET_SIGS (nsigs, sigs, signal_print);
8550 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8552 SET_SIGS (nsigs, sigs, signal_program);
8554 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8556 UNSET_SIGS (nsigs, sigs, signal_stop);
8558 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8560 SET_SIGS (nsigs, sigs, signal_program);
8562 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8564 UNSET_SIGS (nsigs, sigs, signal_print);
8565 UNSET_SIGS (nsigs, sigs, signal_stop);
8567 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8569 UNSET_SIGS (nsigs, sigs, signal_program);
8571 else if (digits > 0)
8573 /* It is numeric. The numeric signal refers to our own
8574 internal signal numbering from target.h, not to host/target
8575 signal number. This is a feature; users really should be
8576 using symbolic names anyway, and the common ones like
8577 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8579 sigfirst = siglast = (int)
8580 gdb_signal_from_command (atoi (arg));
8581 if (arg[digits] == '-')
8584 gdb_signal_from_command (atoi (arg + digits + 1));
8586 if (sigfirst > siglast)
8588 /* Bet he didn't figure we'd think of this case... */
8596 oursig = gdb_signal_from_name (arg);
8597 if (oursig != GDB_SIGNAL_UNKNOWN)
8599 sigfirst = siglast = (int) oursig;
8603 /* Not a number and not a recognized flag word => complain. */
8604 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8608 /* If any signal numbers or symbol names were found, set flags for
8609 which signals to apply actions to. */
8611 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8613 switch ((enum gdb_signal) signum)
8615 case GDB_SIGNAL_TRAP:
8616 case GDB_SIGNAL_INT:
8617 if (!allsigs && !sigs[signum])
8619 if (query (_("%s is used by the debugger.\n\
8620 Are you sure you want to change it? "),
8621 gdb_signal_to_name ((enum gdb_signal) signum)))
8627 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8628 gdb_flush (gdb_stdout);
8633 case GDB_SIGNAL_DEFAULT:
8634 case GDB_SIGNAL_UNKNOWN:
8635 /* Make sure that "all" doesn't print these. */
8644 for (signum = 0; signum < nsigs; signum++)
8647 signal_cache_update (-1);
8648 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8649 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8653 /* Show the results. */
8654 sig_print_header ();
8655 for (; signum < nsigs; signum++)
8657 sig_print_info ((enum gdb_signal) signum);
8664 /* Complete the "handle" command. */
8667 handle_completer (struct cmd_list_element *ignore,
8668 completion_tracker &tracker,
8669 const char *text, const char *word)
8671 static const char * const keywords[] =
8685 signal_completer (ignore, tracker, text, word);
8686 complete_on_enum (tracker, keywords, word, word);
8690 gdb_signal_from_command (int num)
8692 if (num >= 1 && num <= 15)
8693 return (enum gdb_signal) num;
8694 error (_("Only signals 1-15 are valid as numeric signals.\n\
8695 Use \"info signals\" for a list of symbolic signals."));
8698 /* Print current contents of the tables set by the handle command.
8699 It is possible we should just be printing signals actually used
8700 by the current target (but for things to work right when switching
8701 targets, all signals should be in the signal tables). */
8704 info_signals_command (char *signum_exp, int from_tty)
8706 enum gdb_signal oursig;
8708 sig_print_header ();
8712 /* First see if this is a symbol name. */
8713 oursig = gdb_signal_from_name (signum_exp);
8714 if (oursig == GDB_SIGNAL_UNKNOWN)
8716 /* No, try numeric. */
8718 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8720 sig_print_info (oursig);
8724 printf_filtered ("\n");
8725 /* These ugly casts brought to you by the native VAX compiler. */
8726 for (oursig = GDB_SIGNAL_FIRST;
8727 (int) oursig < (int) GDB_SIGNAL_LAST;
8728 oursig = (enum gdb_signal) ((int) oursig + 1))
8732 if (oursig != GDB_SIGNAL_UNKNOWN
8733 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8734 sig_print_info (oursig);
8737 printf_filtered (_("\nUse the \"handle\" command "
8738 "to change these tables.\n"));
8741 /* The $_siginfo convenience variable is a bit special. We don't know
8742 for sure the type of the value until we actually have a chance to
8743 fetch the data. The type can change depending on gdbarch, so it is
8744 also dependent on which thread you have selected.
8746 1. making $_siginfo be an internalvar that creates a new value on
8749 2. making the value of $_siginfo be an lval_computed value. */
8751 /* This function implements the lval_computed support for reading a
8755 siginfo_value_read (struct value *v)
8757 LONGEST transferred;
8759 /* If we can access registers, so can we access $_siginfo. Likewise
8761 validate_registers_access ();
8764 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8766 value_contents_all_raw (v),
8768 TYPE_LENGTH (value_type (v)));
8770 if (transferred != TYPE_LENGTH (value_type (v)))
8771 error (_("Unable to read siginfo"));
8774 /* This function implements the lval_computed support for writing a
8778 siginfo_value_write (struct value *v, struct value *fromval)
8780 LONGEST transferred;
8782 /* If we can access registers, so can we access $_siginfo. Likewise
8784 validate_registers_access ();
8786 transferred = target_write (¤t_target,
8787 TARGET_OBJECT_SIGNAL_INFO,
8789 value_contents_all_raw (fromval),
8791 TYPE_LENGTH (value_type (fromval)));
8793 if (transferred != TYPE_LENGTH (value_type (fromval)))
8794 error (_("Unable to write siginfo"));
8797 static const struct lval_funcs siginfo_value_funcs =
8803 /* Return a new value with the correct type for the siginfo object of
8804 the current thread using architecture GDBARCH. Return a void value
8805 if there's no object available. */
8807 static struct value *
8808 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8811 if (target_has_stack
8812 && !ptid_equal (inferior_ptid, null_ptid)
8813 && gdbarch_get_siginfo_type_p (gdbarch))
8815 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8817 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8820 return allocate_value (builtin_type (gdbarch)->builtin_void);
8824 /* infcall_suspend_state contains state about the program itself like its
8825 registers and any signal it received when it last stopped.
8826 This state must be restored regardless of how the inferior function call
8827 ends (either successfully, or after it hits a breakpoint or signal)
8828 if the program is to properly continue where it left off. */
8830 struct infcall_suspend_state
8832 struct thread_suspend_state thread_suspend;
8836 struct regcache *registers;
8838 /* Format of SIGINFO_DATA or NULL if it is not present. */
8839 struct gdbarch *siginfo_gdbarch;
8841 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8842 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8843 content would be invalid. */
8844 gdb_byte *siginfo_data;
8847 struct infcall_suspend_state *
8848 save_infcall_suspend_state (void)
8850 struct infcall_suspend_state *inf_state;
8851 struct thread_info *tp = inferior_thread ();
8852 struct regcache *regcache = get_current_regcache ();
8853 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8854 gdb_byte *siginfo_data = NULL;
8856 if (gdbarch_get_siginfo_type_p (gdbarch))
8858 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8859 size_t len = TYPE_LENGTH (type);
8860 struct cleanup *back_to;
8862 siginfo_data = (gdb_byte *) xmalloc (len);
8863 back_to = make_cleanup (xfree, siginfo_data);
8865 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8866 siginfo_data, 0, len) == len)
8867 discard_cleanups (back_to);
8870 /* Errors ignored. */
8871 do_cleanups (back_to);
8872 siginfo_data = NULL;
8876 inf_state = XCNEW (struct infcall_suspend_state);
8880 inf_state->siginfo_gdbarch = gdbarch;
8881 inf_state->siginfo_data = siginfo_data;
8884 inf_state->thread_suspend = tp->suspend;
8886 /* run_inferior_call will not use the signal due to its `proceed' call with
8887 GDB_SIGNAL_0 anyway. */
8888 tp->suspend.stop_signal = GDB_SIGNAL_0;
8890 inf_state->stop_pc = stop_pc;
8892 inf_state->registers = regcache_dup (regcache);
8897 /* Restore inferior session state to INF_STATE. */
8900 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8902 struct thread_info *tp = inferior_thread ();
8903 struct regcache *regcache = get_current_regcache ();
8904 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8906 tp->suspend = inf_state->thread_suspend;
8908 stop_pc = inf_state->stop_pc;
8910 if (inf_state->siginfo_gdbarch == gdbarch)
8912 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8914 /* Errors ignored. */
8915 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8916 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8919 /* The inferior can be gone if the user types "print exit(0)"
8920 (and perhaps other times). */
8921 if (target_has_execution)
8922 /* NB: The register write goes through to the target. */
8923 regcache_cpy (regcache, inf_state->registers);
8925 discard_infcall_suspend_state (inf_state);
8929 do_restore_infcall_suspend_state_cleanup (void *state)
8931 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8935 make_cleanup_restore_infcall_suspend_state
8936 (struct infcall_suspend_state *inf_state)
8938 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8942 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8944 regcache_xfree (inf_state->registers);
8945 xfree (inf_state->siginfo_data);
8950 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8952 return inf_state->registers;
8955 /* infcall_control_state contains state regarding gdb's control of the
8956 inferior itself like stepping control. It also contains session state like
8957 the user's currently selected frame. */
8959 struct infcall_control_state
8961 struct thread_control_state thread_control;
8962 struct inferior_control_state inferior_control;
8965 enum stop_stack_kind stop_stack_dummy;
8966 int stopped_by_random_signal;
8968 /* ID if the selected frame when the inferior function call was made. */
8969 struct frame_id selected_frame_id;
8972 /* Save all of the information associated with the inferior<==>gdb
8975 struct infcall_control_state *
8976 save_infcall_control_state (void)
8978 struct infcall_control_state *inf_status =
8979 XNEW (struct infcall_control_state);
8980 struct thread_info *tp = inferior_thread ();
8981 struct inferior *inf = current_inferior ();
8983 inf_status->thread_control = tp->control;
8984 inf_status->inferior_control = inf->control;
8986 tp->control.step_resume_breakpoint = NULL;
8987 tp->control.exception_resume_breakpoint = NULL;
8989 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8990 chain. If caller's caller is walking the chain, they'll be happier if we
8991 hand them back the original chain when restore_infcall_control_state is
8993 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8996 inf_status->stop_stack_dummy = stop_stack_dummy;
8997 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8999 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
9005 restore_selected_frame (void *args)
9007 struct frame_id *fid = (struct frame_id *) args;
9008 struct frame_info *frame;
9010 frame = frame_find_by_id (*fid);
9012 /* If inf_status->selected_frame_id is NULL, there was no previously
9016 warning (_("Unable to restore previously selected frame."));
9020 select_frame (frame);
9025 /* Restore inferior session state to INF_STATUS. */
9028 restore_infcall_control_state (struct infcall_control_state *inf_status)
9030 struct thread_info *tp = inferior_thread ();
9031 struct inferior *inf = current_inferior ();
9033 if (tp->control.step_resume_breakpoint)
9034 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
9036 if (tp->control.exception_resume_breakpoint)
9037 tp->control.exception_resume_breakpoint->disposition
9038 = disp_del_at_next_stop;
9040 /* Handle the bpstat_copy of the chain. */
9041 bpstat_clear (&tp->control.stop_bpstat);
9043 tp->control = inf_status->thread_control;
9044 inf->control = inf_status->inferior_control;
9047 stop_stack_dummy = inf_status->stop_stack_dummy;
9048 stopped_by_random_signal = inf_status->stopped_by_random_signal;
9050 if (target_has_stack)
9052 /* The point of catch_errors is that if the stack is clobbered,
9053 walking the stack might encounter a garbage pointer and
9054 error() trying to dereference it. */
9056 (restore_selected_frame, &inf_status->selected_frame_id,
9057 "Unable to restore previously selected frame:\n",
9058 RETURN_MASK_ERROR) == 0)
9059 /* Error in restoring the selected frame. Select the innermost
9061 select_frame (get_current_frame ());
9068 do_restore_infcall_control_state_cleanup (void *sts)
9070 restore_infcall_control_state ((struct infcall_control_state *) sts);
9074 make_cleanup_restore_infcall_control_state
9075 (struct infcall_control_state *inf_status)
9077 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9081 discard_infcall_control_state (struct infcall_control_state *inf_status)
9083 if (inf_status->thread_control.step_resume_breakpoint)
9084 inf_status->thread_control.step_resume_breakpoint->disposition
9085 = disp_del_at_next_stop;
9087 if (inf_status->thread_control.exception_resume_breakpoint)
9088 inf_status->thread_control.exception_resume_breakpoint->disposition
9089 = disp_del_at_next_stop;
9091 /* See save_infcall_control_state for info on stop_bpstat. */
9092 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9100 clear_exit_convenience_vars (void)
9102 clear_internalvar (lookup_internalvar ("_exitsignal"));
9103 clear_internalvar (lookup_internalvar ("_exitcode"));
9107 /* User interface for reverse debugging:
9108 Set exec-direction / show exec-direction commands
9109 (returns error unless target implements to_set_exec_direction method). */
9111 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9112 static const char exec_forward[] = "forward";
9113 static const char exec_reverse[] = "reverse";
9114 static const char *exec_direction = exec_forward;
9115 static const char *const exec_direction_names[] = {
9122 set_exec_direction_func (char *args, int from_tty,
9123 struct cmd_list_element *cmd)
9125 if (target_can_execute_reverse)
9127 if (!strcmp (exec_direction, exec_forward))
9128 execution_direction = EXEC_FORWARD;
9129 else if (!strcmp (exec_direction, exec_reverse))
9130 execution_direction = EXEC_REVERSE;
9134 exec_direction = exec_forward;
9135 error (_("Target does not support this operation."));
9140 show_exec_direction_func (struct ui_file *out, int from_tty,
9141 struct cmd_list_element *cmd, const char *value)
9143 switch (execution_direction) {
9145 fprintf_filtered (out, _("Forward.\n"));
9148 fprintf_filtered (out, _("Reverse.\n"));
9151 internal_error (__FILE__, __LINE__,
9152 _("bogus execution_direction value: %d"),
9153 (int) execution_direction);
9158 show_schedule_multiple (struct ui_file *file, int from_tty,
9159 struct cmd_list_element *c, const char *value)
9161 fprintf_filtered (file, _("Resuming the execution of threads "
9162 "of all processes is %s.\n"), value);
9165 /* Implementation of `siginfo' variable. */
9167 static const struct internalvar_funcs siginfo_funcs =
9174 /* Callback for infrun's target events source. This is marked when a
9175 thread has a pending status to process. */
9178 infrun_async_inferior_event_handler (gdb_client_data data)
9180 inferior_event_handler (INF_REG_EVENT, NULL);
9184 _initialize_infrun (void)
9188 struct cmd_list_element *c;
9190 /* Register extra event sources in the event loop. */
9191 infrun_async_inferior_event_token
9192 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9194 add_info ("signals", info_signals_command, _("\
9195 What debugger does when program gets various signals.\n\
9196 Specify a signal as argument to print info on that signal only."));
9197 add_info_alias ("handle", "signals", 0);
9199 c = add_com ("handle", class_run, handle_command, _("\
9200 Specify how to handle signals.\n\
9201 Usage: handle SIGNAL [ACTIONS]\n\
9202 Args are signals and actions to apply to those signals.\n\
9203 If no actions are specified, the current settings for the specified signals\n\
9204 will be displayed instead.\n\
9206 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9207 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9208 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9209 The special arg \"all\" is recognized to mean all signals except those\n\
9210 used by the debugger, typically SIGTRAP and SIGINT.\n\
9212 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9213 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9214 Stop means reenter debugger if this signal happens (implies print).\n\
9215 Print means print a message if this signal happens.\n\
9216 Pass means let program see this signal; otherwise program doesn't know.\n\
9217 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9218 Pass and Stop may be combined.\n\
9220 Multiple signals may be specified. Signal numbers and signal names\n\
9221 may be interspersed with actions, with the actions being performed for\n\
9222 all signals cumulatively specified."));
9223 set_cmd_completer (c, handle_completer);
9226 stop_command = add_cmd ("stop", class_obscure,
9227 not_just_help_class_command, _("\
9228 There is no `stop' command, but you can set a hook on `stop'.\n\
9229 This allows you to set a list of commands to be run each time execution\n\
9230 of the program stops."), &cmdlist);
9232 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9233 Set inferior debugging."), _("\
9234 Show inferior debugging."), _("\
9235 When non-zero, inferior specific debugging is enabled."),
9238 &setdebuglist, &showdebuglist);
9240 add_setshow_boolean_cmd ("displaced", class_maintenance,
9241 &debug_displaced, _("\
9242 Set displaced stepping debugging."), _("\
9243 Show displaced stepping debugging."), _("\
9244 When non-zero, displaced stepping specific debugging is enabled."),
9246 show_debug_displaced,
9247 &setdebuglist, &showdebuglist);
9249 add_setshow_boolean_cmd ("non-stop", no_class,
9251 Set whether gdb controls the inferior in non-stop mode."), _("\
9252 Show whether gdb controls the inferior in non-stop mode."), _("\
9253 When debugging a multi-threaded program and this setting is\n\
9254 off (the default, also called all-stop mode), when one thread stops\n\
9255 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9256 all other threads in the program while you interact with the thread of\n\
9257 interest. When you continue or step a thread, you can allow the other\n\
9258 threads to run, or have them remain stopped, but while you inspect any\n\
9259 thread's state, all threads stop.\n\
9261 In non-stop mode, when one thread stops, other threads can continue\n\
9262 to run freely. You'll be able to step each thread independently,\n\
9263 leave it stopped or free to run as needed."),
9269 numsigs = (int) GDB_SIGNAL_LAST;
9270 signal_stop = XNEWVEC (unsigned char, numsigs);
9271 signal_print = XNEWVEC (unsigned char, numsigs);
9272 signal_program = XNEWVEC (unsigned char, numsigs);
9273 signal_catch = XNEWVEC (unsigned char, numsigs);
9274 signal_pass = XNEWVEC (unsigned char, numsigs);
9275 for (i = 0; i < numsigs; i++)
9278 signal_print[i] = 1;
9279 signal_program[i] = 1;
9280 signal_catch[i] = 0;
9283 /* Signals caused by debugger's own actions should not be given to
9284 the program afterwards.
9286 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9287 explicitly specifies that it should be delivered to the target
9288 program. Typically, that would occur when a user is debugging a
9289 target monitor on a simulator: the target monitor sets a
9290 breakpoint; the simulator encounters this breakpoint and halts
9291 the simulation handing control to GDB; GDB, noting that the stop
9292 address doesn't map to any known breakpoint, returns control back
9293 to the simulator; the simulator then delivers the hardware
9294 equivalent of a GDB_SIGNAL_TRAP to the program being
9296 signal_program[GDB_SIGNAL_TRAP] = 0;
9297 signal_program[GDB_SIGNAL_INT] = 0;
9299 /* Signals that are not errors should not normally enter the debugger. */
9300 signal_stop[GDB_SIGNAL_ALRM] = 0;
9301 signal_print[GDB_SIGNAL_ALRM] = 0;
9302 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9303 signal_print[GDB_SIGNAL_VTALRM] = 0;
9304 signal_stop[GDB_SIGNAL_PROF] = 0;
9305 signal_print[GDB_SIGNAL_PROF] = 0;
9306 signal_stop[GDB_SIGNAL_CHLD] = 0;
9307 signal_print[GDB_SIGNAL_CHLD] = 0;
9308 signal_stop[GDB_SIGNAL_IO] = 0;
9309 signal_print[GDB_SIGNAL_IO] = 0;
9310 signal_stop[GDB_SIGNAL_POLL] = 0;
9311 signal_print[GDB_SIGNAL_POLL] = 0;
9312 signal_stop[GDB_SIGNAL_URG] = 0;
9313 signal_print[GDB_SIGNAL_URG] = 0;
9314 signal_stop[GDB_SIGNAL_WINCH] = 0;
9315 signal_print[GDB_SIGNAL_WINCH] = 0;
9316 signal_stop[GDB_SIGNAL_PRIO] = 0;
9317 signal_print[GDB_SIGNAL_PRIO] = 0;
9319 /* These signals are used internally by user-level thread
9320 implementations. (See signal(5) on Solaris.) Like the above
9321 signals, a healthy program receives and handles them as part of
9322 its normal operation. */
9323 signal_stop[GDB_SIGNAL_LWP] = 0;
9324 signal_print[GDB_SIGNAL_LWP] = 0;
9325 signal_stop[GDB_SIGNAL_WAITING] = 0;
9326 signal_print[GDB_SIGNAL_WAITING] = 0;
9327 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9328 signal_print[GDB_SIGNAL_CANCEL] = 0;
9329 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9330 signal_print[GDB_SIGNAL_LIBRT] = 0;
9332 /* Update cached state. */
9333 signal_cache_update (-1);
9335 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9336 &stop_on_solib_events, _("\
9337 Set stopping for shared library events."), _("\
9338 Show stopping for shared library events."), _("\
9339 If nonzero, gdb will give control to the user when the dynamic linker\n\
9340 notifies gdb of shared library events. The most common event of interest\n\
9341 to the user would be loading/unloading of a new library."),
9342 set_stop_on_solib_events,
9343 show_stop_on_solib_events,
9344 &setlist, &showlist);
9346 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9347 follow_fork_mode_kind_names,
9348 &follow_fork_mode_string, _("\
9349 Set debugger response to a program call of fork or vfork."), _("\
9350 Show debugger response to a program call of fork or vfork."), _("\
9351 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9352 parent - the original process is debugged after a fork\n\
9353 child - the new process is debugged after a fork\n\
9354 The unfollowed process will continue to run.\n\
9355 By default, the debugger will follow the parent process."),
9357 show_follow_fork_mode_string,
9358 &setlist, &showlist);
9360 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9361 follow_exec_mode_names,
9362 &follow_exec_mode_string, _("\
9363 Set debugger response to a program call of exec."), _("\
9364 Show debugger response to a program call of exec."), _("\
9365 An exec call replaces the program image of a process.\n\
9367 follow-exec-mode can be:\n\
9369 new - the debugger creates a new inferior and rebinds the process\n\
9370 to this new inferior. The program the process was running before\n\
9371 the exec call can be restarted afterwards by restarting the original\n\
9374 same - the debugger keeps the process bound to the same inferior.\n\
9375 The new executable image replaces the previous executable loaded in\n\
9376 the inferior. Restarting the inferior after the exec call restarts\n\
9377 the executable the process was running after the exec call.\n\
9379 By default, the debugger will use the same inferior."),
9381 show_follow_exec_mode_string,
9382 &setlist, &showlist);
9384 add_setshow_enum_cmd ("scheduler-locking", class_run,
9385 scheduler_enums, &scheduler_mode, _("\
9386 Set mode for locking scheduler during execution."), _("\
9387 Show mode for locking scheduler during execution."), _("\
9388 off == no locking (threads may preempt at any time)\n\
9389 on == full locking (no thread except the current thread may run)\n\
9390 This applies to both normal execution and replay mode.\n\
9391 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9392 In this mode, other threads may run during other commands.\n\
9393 This applies to both normal execution and replay mode.\n\
9394 replay == scheduler locked in replay mode and unlocked during normal execution."),
9395 set_schedlock_func, /* traps on target vector */
9396 show_scheduler_mode,
9397 &setlist, &showlist);
9399 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9400 Set mode for resuming threads of all processes."), _("\
9401 Show mode for resuming threads of all processes."), _("\
9402 When on, execution commands (such as 'continue' or 'next') resume all\n\
9403 threads of all processes. When off (which is the default), execution\n\
9404 commands only resume the threads of the current process. The set of\n\
9405 threads that are resumed is further refined by the scheduler-locking\n\
9406 mode (see help set scheduler-locking)."),
9408 show_schedule_multiple,
9409 &setlist, &showlist);
9411 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9412 Set mode of the step operation."), _("\
9413 Show mode of the step operation."), _("\
9414 When set, doing a step over a function without debug line information\n\
9415 will stop at the first instruction of that function. Otherwise, the\n\
9416 function is skipped and the step command stops at a different source line."),
9418 show_step_stop_if_no_debug,
9419 &setlist, &showlist);
9421 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9422 &can_use_displaced_stepping, _("\
9423 Set debugger's willingness to use displaced stepping."), _("\
9424 Show debugger's willingness to use displaced stepping."), _("\
9425 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9426 supported by the target architecture. If off, gdb will not use displaced\n\
9427 stepping to step over breakpoints, even if such is supported by the target\n\
9428 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9429 if the target architecture supports it and non-stop mode is active, but will not\n\
9430 use it in all-stop mode (see help set non-stop)."),
9432 show_can_use_displaced_stepping,
9433 &setlist, &showlist);
9435 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9436 &exec_direction, _("Set direction of execution.\n\
9437 Options are 'forward' or 'reverse'."),
9438 _("Show direction of execution (forward/reverse)."),
9439 _("Tells gdb whether to execute forward or backward."),
9440 set_exec_direction_func, show_exec_direction_func,
9441 &setlist, &showlist);
9443 /* Set/show detach-on-fork: user-settable mode. */
9445 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9446 Set whether gdb will detach the child of a fork."), _("\
9447 Show whether gdb will detach the child of a fork."), _("\
9448 Tells gdb whether to detach the child of a fork."),
9449 NULL, NULL, &setlist, &showlist);
9451 /* Set/show disable address space randomization mode. */
9453 add_setshow_boolean_cmd ("disable-randomization", class_support,
9454 &disable_randomization, _("\
9455 Set disabling of debuggee's virtual address space randomization."), _("\
9456 Show disabling of debuggee's virtual address space randomization."), _("\
9457 When this mode is on (which is the default), randomization of the virtual\n\
9458 address space is disabled. Standalone programs run with the randomization\n\
9459 enabled by default on some platforms."),
9460 &set_disable_randomization,
9461 &show_disable_randomization,
9462 &setlist, &showlist);
9464 /* ptid initializations */
9465 inferior_ptid = null_ptid;
9466 target_last_wait_ptid = minus_one_ptid;
9468 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9469 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9470 observer_attach_thread_exit (infrun_thread_thread_exit);
9471 observer_attach_inferior_exit (infrun_inferior_exit);
9473 /* Explicitly create without lookup, since that tries to create a
9474 value with a void typed value, and when we get here, gdbarch
9475 isn't initialized yet. At this point, we're quite sure there
9476 isn't another convenience variable of the same name. */
9477 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9479 add_setshow_boolean_cmd ("observer", no_class,
9480 &observer_mode_1, _("\
9481 Set whether gdb controls the inferior in observer mode."), _("\
9482 Show whether gdb controls the inferior in observer mode."), _("\
9483 In observer mode, GDB can get data from the inferior, but not\n\
9484 affect its execution. Registers and memory may not be changed,\n\
9485 breakpoints may not be set, and the program cannot be interrupted\n\