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 nullify_last_target_wait_ptid (void);
100 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
102 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
104 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
106 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
108 /* Asynchronous signal handler registered as event loop source for
109 when we have pending events ready to be passed to the core. */
110 static struct async_event_handler *infrun_async_inferior_event_token;
112 /* Stores whether infrun_async was previously enabled or disabled.
113 Starts off as -1, indicating "never enabled/disabled". */
114 static int infrun_is_async = -1;
119 infrun_async (int enable)
121 if (infrun_is_async != enable)
123 infrun_is_async = enable;
126 fprintf_unfiltered (gdb_stdlog,
127 "infrun: infrun_async(%d)\n",
131 mark_async_event_handler (infrun_async_inferior_event_token);
133 clear_async_event_handler (infrun_async_inferior_event_token);
140 mark_infrun_async_event_handler (void)
142 mark_async_event_handler (infrun_async_inferior_event_token);
145 /* When set, stop the 'step' command if we enter a function which has
146 no line number information. The normal behavior is that we step
147 over such function. */
148 int step_stop_if_no_debug = 0;
150 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
151 struct cmd_list_element *c, const char *value)
153 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
156 /* proceed and normal_stop use this to notify the user when the
157 inferior stopped in a different thread than it had been running
160 static ptid_t previous_inferior_ptid;
162 /* If set (default for legacy reasons), when following a fork, GDB
163 will detach from one of the fork branches, child or parent.
164 Exactly which branch is detached depends on 'set follow-fork-mode'
167 static int detach_fork = 1;
169 int debug_displaced = 0;
171 show_debug_displaced (struct ui_file *file, int from_tty,
172 struct cmd_list_element *c, const char *value)
174 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
177 unsigned int debug_infrun = 0;
179 show_debug_infrun (struct ui_file *file, int from_tty,
180 struct cmd_list_element *c, const char *value)
182 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
186 /* Support for disabling address space randomization. */
188 int disable_randomization = 1;
191 show_disable_randomization (struct ui_file *file, int from_tty,
192 struct cmd_list_element *c, const char *value)
194 if (target_supports_disable_randomization ())
195 fprintf_filtered (file,
196 _("Disabling randomization of debuggee's "
197 "virtual address space is %s.\n"),
200 fputs_filtered (_("Disabling randomization of debuggee's "
201 "virtual address space is unsupported on\n"
202 "this platform.\n"), file);
206 set_disable_randomization (char *args, int from_tty,
207 struct cmd_list_element *c)
209 if (!target_supports_disable_randomization ())
210 error (_("Disabling randomization of debuggee's "
211 "virtual address space is unsupported on\n"
215 /* User interface for non-stop mode. */
218 static int non_stop_1 = 0;
221 set_non_stop (char *args, int from_tty,
222 struct cmd_list_element *c)
224 if (target_has_execution)
226 non_stop_1 = non_stop;
227 error (_("Cannot change this setting while the inferior is running."));
230 non_stop = non_stop_1;
234 show_non_stop (struct ui_file *file, int from_tty,
235 struct cmd_list_element *c, const char *value)
237 fprintf_filtered (file,
238 _("Controlling the inferior in non-stop mode is %s.\n"),
242 /* "Observer mode" is somewhat like a more extreme version of
243 non-stop, in which all GDB operations that might affect the
244 target's execution have been disabled. */
246 int observer_mode = 0;
247 static int observer_mode_1 = 0;
250 set_observer_mode (char *args, int from_tty,
251 struct cmd_list_element *c)
253 if (target_has_execution)
255 observer_mode_1 = observer_mode;
256 error (_("Cannot change this setting while the inferior is running."));
259 observer_mode = observer_mode_1;
261 may_write_registers = !observer_mode;
262 may_write_memory = !observer_mode;
263 may_insert_breakpoints = !observer_mode;
264 may_insert_tracepoints = !observer_mode;
265 /* We can insert fast tracepoints in or out of observer mode,
266 but enable them if we're going into this mode. */
268 may_insert_fast_tracepoints = 1;
269 may_stop = !observer_mode;
270 update_target_permissions ();
272 /* Going *into* observer mode we must force non-stop, then
273 going out we leave it that way. */
276 pagination_enabled = 0;
277 non_stop = non_stop_1 = 1;
281 printf_filtered (_("Observer mode is now %s.\n"),
282 (observer_mode ? "on" : "off"));
286 show_observer_mode (struct ui_file *file, int from_tty,
287 struct cmd_list_element *c, const char *value)
289 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
292 /* This updates the value of observer mode based on changes in
293 permissions. Note that we are deliberately ignoring the values of
294 may-write-registers and may-write-memory, since the user may have
295 reason to enable these during a session, for instance to turn on a
296 debugging-related global. */
299 update_observer_mode (void)
303 newval = (!may_insert_breakpoints
304 && !may_insert_tracepoints
305 && may_insert_fast_tracepoints
309 /* Let the user know if things change. */
310 if (newval != observer_mode)
311 printf_filtered (_("Observer mode is now %s.\n"),
312 (newval ? "on" : "off"));
314 observer_mode = observer_mode_1 = newval;
317 /* Tables of how to react to signals; the user sets them. */
319 static unsigned char *signal_stop;
320 static unsigned char *signal_print;
321 static unsigned char *signal_program;
323 /* Table of signals that are registered with "catch signal". A
324 non-zero entry indicates that the signal is caught by some "catch
325 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
327 static unsigned char *signal_catch;
329 /* Table of signals that the target may silently handle.
330 This is automatically determined from the flags above,
331 and simply cached here. */
332 static unsigned char *signal_pass;
334 #define SET_SIGS(nsigs,sigs,flags) \
336 int signum = (nsigs); \
337 while (signum-- > 0) \
338 if ((sigs)[signum]) \
339 (flags)[signum] = 1; \
342 #define UNSET_SIGS(nsigs,sigs,flags) \
344 int signum = (nsigs); \
345 while (signum-- > 0) \
346 if ((sigs)[signum]) \
347 (flags)[signum] = 0; \
350 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
351 this function is to avoid exporting `signal_program'. */
354 update_signals_program_target (void)
356 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
359 /* Value to pass to target_resume() to cause all threads to resume. */
361 #define RESUME_ALL minus_one_ptid
363 /* Command list pointer for the "stop" placeholder. */
365 static struct cmd_list_element *stop_command;
367 /* Nonzero if we want to give control to the user when we're notified
368 of shared library events by the dynamic linker. */
369 int stop_on_solib_events;
371 /* Enable or disable optional shared library event breakpoints
372 as appropriate when the above flag is changed. */
375 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
377 update_solib_breakpoints ();
381 show_stop_on_solib_events (struct ui_file *file, int from_tty,
382 struct cmd_list_element *c, const char *value)
384 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
388 /* Nonzero after stop if current stack frame should be printed. */
390 static int stop_print_frame;
392 /* This is a cached copy of the pid/waitstatus of the last event
393 returned by target_wait()/deprecated_target_wait_hook(). This
394 information is returned by get_last_target_status(). */
395 static ptid_t target_last_wait_ptid;
396 static struct target_waitstatus target_last_waitstatus;
398 static void context_switch (ptid_t ptid);
400 void init_thread_stepping_state (struct thread_info *tss);
402 static const char follow_fork_mode_child[] = "child";
403 static const char follow_fork_mode_parent[] = "parent";
405 static const char *const follow_fork_mode_kind_names[] = {
406 follow_fork_mode_child,
407 follow_fork_mode_parent,
411 static const char *follow_fork_mode_string = follow_fork_mode_parent;
413 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
414 struct cmd_list_element *c, const char *value)
416 fprintf_filtered (file,
417 _("Debugger response to a program "
418 "call of fork or vfork is \"%s\".\n"),
423 /* Handle changes to the inferior list based on the type of fork,
424 which process is being followed, and whether the other process
425 should be detached. On entry inferior_ptid must be the ptid of
426 the fork parent. At return inferior_ptid is the ptid of the
427 followed inferior. */
430 follow_fork_inferior (int follow_child, int detach_fork)
433 ptid_t parent_ptid, child_ptid;
435 has_vforked = (inferior_thread ()->pending_follow.kind
436 == TARGET_WAITKIND_VFORKED);
437 parent_ptid = inferior_ptid;
438 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
441 && !non_stop /* Non-stop always resumes both branches. */
442 && current_ui->prompt_state == PROMPT_BLOCKED
443 && !(follow_child || detach_fork || sched_multi))
445 /* The parent stays blocked inside the vfork syscall until the
446 child execs or exits. If we don't let the child run, then
447 the parent stays blocked. If we're telling the parent to run
448 in the foreground, the user will not be able to ctrl-c to get
449 back the terminal, effectively hanging the debug session. */
450 fprintf_filtered (gdb_stderr, _("\
451 Can not resume the parent process over vfork in the foreground while\n\
452 holding the child stopped. Try \"set detach-on-fork\" or \
453 \"set schedule-multiple\".\n"));
454 /* FIXME output string > 80 columns. */
460 /* Detach new forked process? */
463 /* Before detaching from the child, remove all breakpoints
464 from it. If we forked, then this has already been taken
465 care of by infrun.c. If we vforked however, any
466 breakpoint inserted in the parent is visible in the
467 child, even those added while stopped in a vfork
468 catchpoint. This will remove the breakpoints from the
469 parent also, but they'll be reinserted below. */
472 /* Keep breakpoints list in sync. */
473 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
476 if (info_verbose || debug_infrun)
478 /* Ensure that we have a process ptid. */
479 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
481 target_terminal::ours_for_output ();
482 fprintf_filtered (gdb_stdlog,
483 _("Detaching after %s from child %s.\n"),
484 has_vforked ? "vfork" : "fork",
485 target_pid_to_str (process_ptid));
490 struct inferior *parent_inf, *child_inf;
492 /* Add process to GDB's tables. */
493 child_inf = add_inferior (ptid_get_pid (child_ptid));
495 parent_inf = current_inferior ();
496 child_inf->attach_flag = parent_inf->attach_flag;
497 copy_terminal_info (child_inf, parent_inf);
498 child_inf->gdbarch = parent_inf->gdbarch;
499 copy_inferior_target_desc_info (child_inf, parent_inf);
501 scoped_restore_current_pspace_and_thread restore_pspace_thread;
503 inferior_ptid = child_ptid;
504 add_thread (inferior_ptid);
505 set_current_inferior (child_inf);
506 child_inf->symfile_flags = SYMFILE_NO_READ;
508 /* If this is a vfork child, then the address-space is
509 shared with the parent. */
512 child_inf->pspace = parent_inf->pspace;
513 child_inf->aspace = parent_inf->aspace;
515 /* The parent will be frozen until the child is done
516 with the shared region. Keep track of the
518 child_inf->vfork_parent = parent_inf;
519 child_inf->pending_detach = 0;
520 parent_inf->vfork_child = child_inf;
521 parent_inf->pending_detach = 0;
525 child_inf->aspace = new_address_space ();
526 child_inf->pspace = add_program_space (child_inf->aspace);
527 child_inf->removable = 1;
528 set_current_program_space (child_inf->pspace);
529 clone_program_space (child_inf->pspace, parent_inf->pspace);
531 /* Let the shared library layer (e.g., solib-svr4) learn
532 about this new process, relocate the cloned exec, pull
533 in shared libraries, and install the solib event
534 breakpoint. If a "cloned-VM" event was propagated
535 better throughout the core, this wouldn't be
537 solib_create_inferior_hook (0);
543 struct inferior *parent_inf;
545 parent_inf = current_inferior ();
547 /* If we detached from the child, then we have to be careful
548 to not insert breakpoints in the parent until the child
549 is done with the shared memory region. However, if we're
550 staying attached to the child, then we can and should
551 insert breakpoints, so that we can debug it. A
552 subsequent child exec or exit is enough to know when does
553 the child stops using the parent's address space. */
554 parent_inf->waiting_for_vfork_done = detach_fork;
555 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
560 /* Follow the child. */
561 struct inferior *parent_inf, *child_inf;
562 struct program_space *parent_pspace;
564 if (info_verbose || debug_infrun)
566 target_terminal::ours_for_output ();
567 fprintf_filtered (gdb_stdlog,
568 _("Attaching after %s %s to child %s.\n"),
569 target_pid_to_str (parent_ptid),
570 has_vforked ? "vfork" : "fork",
571 target_pid_to_str (child_ptid));
574 /* Add the new inferior first, so that the target_detach below
575 doesn't unpush the target. */
577 child_inf = add_inferior (ptid_get_pid (child_ptid));
579 parent_inf = current_inferior ();
580 child_inf->attach_flag = parent_inf->attach_flag;
581 copy_terminal_info (child_inf, parent_inf);
582 child_inf->gdbarch = parent_inf->gdbarch;
583 copy_inferior_target_desc_info (child_inf, parent_inf);
585 parent_pspace = parent_inf->pspace;
587 /* If we're vforking, we want to hold on to the parent until the
588 child exits or execs. At child exec or exit time we can
589 remove the old breakpoints from the parent and detach or
590 resume debugging it. Otherwise, detach the parent now; we'll
591 want to reuse it's program/address spaces, but we can't set
592 them to the child before removing breakpoints from the
593 parent, otherwise, the breakpoints module could decide to
594 remove breakpoints from the wrong process (since they'd be
595 assigned to the same address space). */
599 gdb_assert (child_inf->vfork_parent == NULL);
600 gdb_assert (parent_inf->vfork_child == NULL);
601 child_inf->vfork_parent = parent_inf;
602 child_inf->pending_detach = 0;
603 parent_inf->vfork_child = child_inf;
604 parent_inf->pending_detach = detach_fork;
605 parent_inf->waiting_for_vfork_done = 0;
607 else if (detach_fork)
609 if (info_verbose || debug_infrun)
611 /* Ensure that we have a process ptid. */
612 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
614 target_terminal::ours_for_output ();
615 fprintf_filtered (gdb_stdlog,
616 _("Detaching after fork from "
618 target_pid_to_str (process_ptid));
621 target_detach (NULL, 0);
624 /* Note that the detach above makes PARENT_INF dangling. */
626 /* Add the child thread to the appropriate lists, and switch to
627 this new thread, before cloning the program space, and
628 informing the solib layer about this new process. */
630 inferior_ptid = child_ptid;
631 add_thread (inferior_ptid);
632 set_current_inferior (child_inf);
634 /* If this is a vfork child, then the address-space is shared
635 with the parent. If we detached from the parent, then we can
636 reuse the parent's program/address spaces. */
637 if (has_vforked || detach_fork)
639 child_inf->pspace = parent_pspace;
640 child_inf->aspace = child_inf->pspace->aspace;
644 child_inf->aspace = new_address_space ();
645 child_inf->pspace = add_program_space (child_inf->aspace);
646 child_inf->removable = 1;
647 child_inf->symfile_flags = SYMFILE_NO_READ;
648 set_current_program_space (child_inf->pspace);
649 clone_program_space (child_inf->pspace, parent_pspace);
651 /* Let the shared library layer (e.g., solib-svr4) learn
652 about this new process, relocate the cloned exec, pull in
653 shared libraries, and install the solib event breakpoint.
654 If a "cloned-VM" event was propagated better throughout
655 the core, this wouldn't be required. */
656 solib_create_inferior_hook (0);
660 return target_follow_fork (follow_child, detach_fork);
663 /* Tell the target to follow the fork we're stopped at. Returns true
664 if the inferior should be resumed; false, if the target for some
665 reason decided it's best not to resume. */
670 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
671 int should_resume = 1;
672 struct thread_info *tp;
674 /* Copy user stepping state to the new inferior thread. FIXME: the
675 followed fork child thread should have a copy of most of the
676 parent thread structure's run control related fields, not just these.
677 Initialized to avoid "may be used uninitialized" warnings from gcc. */
678 struct breakpoint *step_resume_breakpoint = NULL;
679 struct breakpoint *exception_resume_breakpoint = NULL;
680 CORE_ADDR step_range_start = 0;
681 CORE_ADDR step_range_end = 0;
682 struct frame_id step_frame_id = { 0 };
683 struct thread_fsm *thread_fsm = NULL;
688 struct target_waitstatus wait_status;
690 /* Get the last target status returned by target_wait(). */
691 get_last_target_status (&wait_ptid, &wait_status);
693 /* If not stopped at a fork event, then there's nothing else to
695 if (wait_status.kind != TARGET_WAITKIND_FORKED
696 && wait_status.kind != TARGET_WAITKIND_VFORKED)
699 /* Check if we switched over from WAIT_PTID, since the event was
701 if (!ptid_equal (wait_ptid, minus_one_ptid)
702 && !ptid_equal (inferior_ptid, wait_ptid))
704 /* We did. Switch back to WAIT_PTID thread, to tell the
705 target to follow it (in either direction). We'll
706 afterwards refuse to resume, and inform the user what
708 switch_to_thread (wait_ptid);
713 tp = inferior_thread ();
715 /* If there were any forks/vforks that were caught and are now to be
716 followed, then do so now. */
717 switch (tp->pending_follow.kind)
719 case TARGET_WAITKIND_FORKED:
720 case TARGET_WAITKIND_VFORKED:
722 ptid_t parent, child;
724 /* If the user did a next/step, etc, over a fork call,
725 preserve the stepping state in the fork child. */
726 if (follow_child && should_resume)
728 step_resume_breakpoint = clone_momentary_breakpoint
729 (tp->control.step_resume_breakpoint);
730 step_range_start = tp->control.step_range_start;
731 step_range_end = tp->control.step_range_end;
732 step_frame_id = tp->control.step_frame_id;
733 exception_resume_breakpoint
734 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
735 thread_fsm = tp->thread_fsm;
737 /* For now, delete the parent's sr breakpoint, otherwise,
738 parent/child sr breakpoints are considered duplicates,
739 and the child version will not be installed. Remove
740 this when the breakpoints module becomes aware of
741 inferiors and address spaces. */
742 delete_step_resume_breakpoint (tp);
743 tp->control.step_range_start = 0;
744 tp->control.step_range_end = 0;
745 tp->control.step_frame_id = null_frame_id;
746 delete_exception_resume_breakpoint (tp);
747 tp->thread_fsm = NULL;
750 parent = inferior_ptid;
751 child = tp->pending_follow.value.related_pid;
753 /* Set up inferior(s) as specified by the caller, and tell the
754 target to do whatever is necessary to follow either parent
756 if (follow_fork_inferior (follow_child, detach_fork))
758 /* Target refused to follow, or there's some other reason
759 we shouldn't resume. */
764 /* This pending follow fork event is now handled, one way
765 or another. The previous selected thread may be gone
766 from the lists by now, but if it is still around, need
767 to clear the pending follow request. */
768 tp = find_thread_ptid (parent);
770 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
772 /* This makes sure we don't try to apply the "Switched
773 over from WAIT_PID" logic above. */
774 nullify_last_target_wait_ptid ();
776 /* If we followed the child, switch to it... */
779 switch_to_thread (child);
781 /* ... and preserve the stepping state, in case the
782 user was stepping over the fork call. */
785 tp = inferior_thread ();
786 tp->control.step_resume_breakpoint
787 = step_resume_breakpoint;
788 tp->control.step_range_start = step_range_start;
789 tp->control.step_range_end = step_range_end;
790 tp->control.step_frame_id = step_frame_id;
791 tp->control.exception_resume_breakpoint
792 = exception_resume_breakpoint;
793 tp->thread_fsm = thread_fsm;
797 /* If we get here, it was because we're trying to
798 resume from a fork catchpoint, but, the user
799 has switched threads away from the thread that
800 forked. In that case, the resume command
801 issued is most likely not applicable to the
802 child, so just warn, and refuse to resume. */
803 warning (_("Not resuming: switched threads "
804 "before following fork child."));
807 /* Reset breakpoints in the child as appropriate. */
808 follow_inferior_reset_breakpoints ();
811 switch_to_thread (parent);
815 case TARGET_WAITKIND_SPURIOUS:
816 /* Nothing to follow. */
819 internal_error (__FILE__, __LINE__,
820 "Unexpected pending_follow.kind %d\n",
821 tp->pending_follow.kind);
825 return should_resume;
829 follow_inferior_reset_breakpoints (void)
831 struct thread_info *tp = inferior_thread ();
833 /* Was there a step_resume breakpoint? (There was if the user
834 did a "next" at the fork() call.) If so, explicitly reset its
835 thread number. Cloned step_resume breakpoints are disabled on
836 creation, so enable it here now that it is associated with the
839 step_resumes are a form of bp that are made to be per-thread.
840 Since we created the step_resume bp when the parent process
841 was being debugged, and now are switching to the child process,
842 from the breakpoint package's viewpoint, that's a switch of
843 "threads". We must update the bp's notion of which thread
844 it is for, or it'll be ignored when it triggers. */
846 if (tp->control.step_resume_breakpoint)
848 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
849 tp->control.step_resume_breakpoint->loc->enabled = 1;
852 /* Treat exception_resume breakpoints like step_resume breakpoints. */
853 if (tp->control.exception_resume_breakpoint)
855 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
856 tp->control.exception_resume_breakpoint->loc->enabled = 1;
859 /* Reinsert all breakpoints in the child. The user may have set
860 breakpoints after catching the fork, in which case those
861 were never set in the child, but only in the parent. This makes
862 sure the inserted breakpoints match the breakpoint list. */
864 breakpoint_re_set ();
865 insert_breakpoints ();
868 /* The child has exited or execed: resume threads of the parent the
869 user wanted to be executing. */
872 proceed_after_vfork_done (struct thread_info *thread,
875 int pid = * (int *) arg;
877 if (ptid_get_pid (thread->ptid) == pid
878 && is_running (thread->ptid)
879 && !is_executing (thread->ptid)
880 && !thread->stop_requested
881 && thread->suspend.stop_signal == GDB_SIGNAL_0)
884 fprintf_unfiltered (gdb_stdlog,
885 "infrun: resuming vfork parent thread %s\n",
886 target_pid_to_str (thread->ptid));
888 switch_to_thread (thread->ptid);
889 clear_proceed_status (0);
890 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
896 /* Save/restore inferior_ptid, current program space and current
897 inferior. Only use this if the current context points at an exited
898 inferior (and therefore there's no current thread to save). */
899 class scoped_restore_exited_inferior
902 scoped_restore_exited_inferior ()
903 : m_saved_ptid (&inferior_ptid)
907 scoped_restore_tmpl<ptid_t> m_saved_ptid;
908 scoped_restore_current_program_space m_pspace;
909 scoped_restore_current_inferior m_inferior;
912 /* Called whenever we notice an exec or exit event, to handle
913 detaching or resuming a vfork parent. */
916 handle_vfork_child_exec_or_exit (int exec)
918 struct inferior *inf = current_inferior ();
920 if (inf->vfork_parent)
922 int resume_parent = -1;
924 /* This exec or exit marks the end of the shared memory region
925 between the parent and the child. If the user wanted to
926 detach from the parent, now is the time. */
928 if (inf->vfork_parent->pending_detach)
930 struct thread_info *tp;
931 struct program_space *pspace;
932 struct address_space *aspace;
934 /* follow-fork child, detach-on-fork on. */
936 inf->vfork_parent->pending_detach = 0;
938 gdb::optional<scoped_restore_exited_inferior>
939 maybe_restore_inferior;
940 gdb::optional<scoped_restore_current_pspace_and_thread>
941 maybe_restore_thread;
943 /* If we're handling a child exit, then inferior_ptid points
944 at the inferior's pid, not to a thread. */
946 maybe_restore_inferior.emplace ();
948 maybe_restore_thread.emplace ();
950 /* We're letting loose of the parent. */
951 tp = any_live_thread_of_process (inf->vfork_parent->pid);
952 switch_to_thread (tp->ptid);
954 /* We're about to detach from the parent, which implicitly
955 removes breakpoints from its address space. There's a
956 catch here: we want to reuse the spaces for the child,
957 but, parent/child are still sharing the pspace at this
958 point, although the exec in reality makes the kernel give
959 the child a fresh set of new pages. The problem here is
960 that the breakpoints module being unaware of this, would
961 likely chose the child process to write to the parent
962 address space. Swapping the child temporarily away from
963 the spaces has the desired effect. Yes, this is "sort
966 pspace = inf->pspace;
967 aspace = inf->aspace;
971 if (debug_infrun || info_verbose)
973 target_terminal::ours_for_output ();
977 fprintf_filtered (gdb_stdlog,
978 _("Detaching vfork parent process "
979 "%d after child exec.\n"),
980 inf->vfork_parent->pid);
984 fprintf_filtered (gdb_stdlog,
985 _("Detaching vfork parent process "
986 "%d after child exit.\n"),
987 inf->vfork_parent->pid);
991 target_detach (NULL, 0);
994 inf->pspace = pspace;
995 inf->aspace = aspace;
999 /* We're staying attached to the parent, so, really give the
1000 child a new address space. */
1001 inf->pspace = add_program_space (maybe_new_address_space ());
1002 inf->aspace = inf->pspace->aspace;
1004 set_current_program_space (inf->pspace);
1006 resume_parent = inf->vfork_parent->pid;
1008 /* Break the bonds. */
1009 inf->vfork_parent->vfork_child = NULL;
1013 struct program_space *pspace;
1015 /* If this is a vfork child exiting, then the pspace and
1016 aspaces were shared with the parent. Since we're
1017 reporting the process exit, we'll be mourning all that is
1018 found in the address space, and switching to null_ptid,
1019 preparing to start a new inferior. But, since we don't
1020 want to clobber the parent's address/program spaces, we
1021 go ahead and create a new one for this exiting
1024 /* Switch to null_ptid while running clone_program_space, so
1025 that clone_program_space doesn't want to read the
1026 selected frame of a dead process. */
1027 scoped_restore restore_ptid
1028 = make_scoped_restore (&inferior_ptid, null_ptid);
1030 /* This inferior is dead, so avoid giving the breakpoints
1031 module the option to write through to it (cloning a
1032 program space resets breakpoints). */
1035 pspace = add_program_space (maybe_new_address_space ());
1036 set_current_program_space (pspace);
1038 inf->symfile_flags = SYMFILE_NO_READ;
1039 clone_program_space (pspace, inf->vfork_parent->pspace);
1040 inf->pspace = pspace;
1041 inf->aspace = pspace->aspace;
1043 resume_parent = inf->vfork_parent->pid;
1044 /* Break the bonds. */
1045 inf->vfork_parent->vfork_child = NULL;
1048 inf->vfork_parent = NULL;
1050 gdb_assert (current_program_space == inf->pspace);
1052 if (non_stop && resume_parent != -1)
1054 /* If the user wanted the parent to be running, let it go
1056 scoped_restore_current_thread restore_thread;
1059 fprintf_unfiltered (gdb_stdlog,
1060 "infrun: resuming vfork parent process %d\n",
1063 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1068 /* Enum strings for "set|show follow-exec-mode". */
1070 static const char follow_exec_mode_new[] = "new";
1071 static const char follow_exec_mode_same[] = "same";
1072 static const char *const follow_exec_mode_names[] =
1074 follow_exec_mode_new,
1075 follow_exec_mode_same,
1079 static const char *follow_exec_mode_string = follow_exec_mode_same;
1081 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1082 struct cmd_list_element *c, const char *value)
1084 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1087 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1090 follow_exec (ptid_t ptid, char *exec_file_target)
1092 struct thread_info *th, *tmp;
1093 struct inferior *inf = current_inferior ();
1094 int pid = ptid_get_pid (ptid);
1095 ptid_t process_ptid;
1096 char *exec_file_host;
1097 struct cleanup *old_chain;
1099 /* This is an exec event that we actually wish to pay attention to.
1100 Refresh our symbol table to the newly exec'd program, remove any
1101 momentary bp's, etc.
1103 If there are breakpoints, they aren't really inserted now,
1104 since the exec() transformed our inferior into a fresh set
1107 We want to preserve symbolic breakpoints on the list, since
1108 we have hopes that they can be reset after the new a.out's
1109 symbol table is read.
1111 However, any "raw" breakpoints must be removed from the list
1112 (e.g., the solib bp's), since their address is probably invalid
1115 And, we DON'T want to call delete_breakpoints() here, since
1116 that may write the bp's "shadow contents" (the instruction
1117 value that was overwritten witha TRAP instruction). Since
1118 we now have a new a.out, those shadow contents aren't valid. */
1120 mark_breakpoints_out ();
1122 /* The target reports the exec event to the main thread, even if
1123 some other thread does the exec, and even if the main thread was
1124 stopped or already gone. We may still have non-leader threads of
1125 the process on our list. E.g., on targets that don't have thread
1126 exit events (like remote); or on native Linux in non-stop mode if
1127 there were only two threads in the inferior and the non-leader
1128 one is the one that execs (and nothing forces an update of the
1129 thread list up to here). When debugging remotely, it's best to
1130 avoid extra traffic, when possible, so avoid syncing the thread
1131 list with the target, and instead go ahead and delete all threads
1132 of the process but one that reported the event. Note this must
1133 be done before calling update_breakpoints_after_exec, as
1134 otherwise clearing the threads' resources would reference stale
1135 thread breakpoints -- it may have been one of these threads that
1136 stepped across the exec. We could just clear their stepping
1137 states, but as long as we're iterating, might as well delete
1138 them. Deleting them now rather than at the next user-visible
1139 stop provides a nicer sequence of events for user and MI
1141 ALL_THREADS_SAFE (th, tmp)
1142 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1143 delete_thread (th->ptid);
1145 /* We also need to clear any left over stale state for the
1146 leader/event thread. E.g., if there was any step-resume
1147 breakpoint or similar, it's gone now. We cannot truly
1148 step-to-next statement through an exec(). */
1149 th = inferior_thread ();
1150 th->control.step_resume_breakpoint = NULL;
1151 th->control.exception_resume_breakpoint = NULL;
1152 th->control.single_step_breakpoints = NULL;
1153 th->control.step_range_start = 0;
1154 th->control.step_range_end = 0;
1156 /* The user may have had the main thread held stopped in the
1157 previous image (e.g., schedlock on, or non-stop). Release
1159 th->stop_requested = 0;
1161 update_breakpoints_after_exec ();
1163 /* What is this a.out's name? */
1164 process_ptid = pid_to_ptid (pid);
1165 printf_unfiltered (_("%s is executing new program: %s\n"),
1166 target_pid_to_str (process_ptid),
1169 /* We've followed the inferior through an exec. Therefore, the
1170 inferior has essentially been killed & reborn. */
1172 gdb_flush (gdb_stdout);
1174 breakpoint_init_inferior (inf_execd);
1176 exec_file_host = exec_file_find (exec_file_target, NULL);
1177 old_chain = make_cleanup (xfree, exec_file_host);
1179 /* If we were unable to map the executable target pathname onto a host
1180 pathname, tell the user that. Otherwise GDB's subsequent behavior
1181 is confusing. Maybe it would even be better to stop at this point
1182 so that the user can specify a file manually before continuing. */
1183 if (exec_file_host == NULL)
1184 warning (_("Could not load symbols for executable %s.\n"
1185 "Do you need \"set sysroot\"?"),
1188 /* Reset the shared library package. This ensures that we get a
1189 shlib event when the child reaches "_start", at which point the
1190 dld will have had a chance to initialize the child. */
1191 /* Also, loading a symbol file below may trigger symbol lookups, and
1192 we don't want those to be satisfied by the libraries of the
1193 previous incarnation of this process. */
1194 no_shared_libraries (NULL, 0);
1196 if (follow_exec_mode_string == follow_exec_mode_new)
1198 /* The user wants to keep the old inferior and program spaces
1199 around. Create a new fresh one, and switch to it. */
1201 /* Do exit processing for the original inferior before adding
1202 the new inferior so we don't have two active inferiors with
1203 the same ptid, which can confuse find_inferior_ptid. */
1204 exit_inferior_num_silent (current_inferior ()->num);
1206 inf = add_inferior_with_spaces ();
1208 target_follow_exec (inf, exec_file_target);
1210 set_current_inferior (inf);
1211 set_current_program_space (inf->pspace);
1215 /* The old description may no longer be fit for the new image.
1216 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1217 old description; we'll read a new one below. No need to do
1218 this on "follow-exec-mode new", as the old inferior stays
1219 around (its description is later cleared/refetched on
1221 target_clear_description ();
1224 gdb_assert (current_program_space == inf->pspace);
1226 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1227 because the proper displacement for a PIE (Position Independent
1228 Executable) main symbol file will only be computed by
1229 solib_create_inferior_hook below. breakpoint_re_set would fail
1230 to insert the breakpoints with the zero displacement. */
1231 try_open_exec_file (exec_file_host, inf, SYMFILE_DEFER_BP_RESET);
1233 do_cleanups (old_chain);
1235 /* If the target can specify a description, read it. Must do this
1236 after flipping to the new executable (because the target supplied
1237 description must be compatible with the executable's
1238 architecture, and the old executable may e.g., be 32-bit, while
1239 the new one 64-bit), and before anything involving memory or
1241 target_find_description ();
1243 /* The add_thread call ends up reading registers, so do it after updating the
1244 target description. */
1245 if (follow_exec_mode_string == follow_exec_mode_new)
1248 solib_create_inferior_hook (0);
1250 jit_inferior_created_hook ();
1252 breakpoint_re_set ();
1254 /* Reinsert all breakpoints. (Those which were symbolic have
1255 been reset to the proper address in the new a.out, thanks
1256 to symbol_file_command...). */
1257 insert_breakpoints ();
1259 /* The next resume of this inferior should bring it to the shlib
1260 startup breakpoints. (If the user had also set bp's on
1261 "main" from the old (parent) process, then they'll auto-
1262 matically get reset there in the new process.). */
1265 /* The queue of threads that need to do a step-over operation to get
1266 past e.g., a breakpoint. What technique is used to step over the
1267 breakpoint/watchpoint does not matter -- all threads end up in the
1268 same queue, to maintain rough temporal order of execution, in order
1269 to avoid starvation, otherwise, we could e.g., find ourselves
1270 constantly stepping the same couple threads past their breakpoints
1271 over and over, if the single-step finish fast enough. */
1272 struct thread_info *step_over_queue_head;
1274 /* Bit flags indicating what the thread needs to step over. */
1276 enum step_over_what_flag
1278 /* Step over a breakpoint. */
1279 STEP_OVER_BREAKPOINT = 1,
1281 /* Step past a non-continuable watchpoint, in order to let the
1282 instruction execute so we can evaluate the watchpoint
1284 STEP_OVER_WATCHPOINT = 2
1286 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1288 /* Info about an instruction that is being stepped over. */
1290 struct step_over_info
1292 /* If we're stepping past a breakpoint, this is the address space
1293 and address of the instruction the breakpoint is set at. We'll
1294 skip inserting all breakpoints here. Valid iff ASPACE is
1296 struct address_space *aspace;
1299 /* The instruction being stepped over triggers a nonsteppable
1300 watchpoint. If true, we'll skip inserting watchpoints. */
1301 int nonsteppable_watchpoint_p;
1303 /* The thread's global number. */
1307 /* The step-over info of the location that is being stepped over.
1309 Note that with async/breakpoint always-inserted mode, a user might
1310 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1311 being stepped over. As setting a new breakpoint inserts all
1312 breakpoints, we need to make sure the breakpoint being stepped over
1313 isn't inserted then. We do that by only clearing the step-over
1314 info when the step-over is actually finished (or aborted).
1316 Presently GDB can only step over one breakpoint at any given time.
1317 Given threads that can't run code in the same address space as the
1318 breakpoint's can't really miss the breakpoint, GDB could be taught
1319 to step-over at most one breakpoint per address space (so this info
1320 could move to the address space object if/when GDB is extended).
1321 The set of breakpoints being stepped over will normally be much
1322 smaller than the set of all breakpoints, so a flag in the
1323 breakpoint location structure would be wasteful. A separate list
1324 also saves complexity and run-time, as otherwise we'd have to go
1325 through all breakpoint locations clearing their flag whenever we
1326 start a new sequence. Similar considerations weigh against storing
1327 this info in the thread object. Plus, not all step overs actually
1328 have breakpoint locations -- e.g., stepping past a single-step
1329 breakpoint, or stepping to complete a non-continuable
1331 static struct step_over_info step_over_info;
1333 /* Record the address of the breakpoint/instruction we're currently
1335 N.B. We record the aspace and address now, instead of say just the thread,
1336 because when we need the info later the thread may be running. */
1339 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1340 int nonsteppable_watchpoint_p,
1343 step_over_info.aspace = aspace;
1344 step_over_info.address = address;
1345 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1346 step_over_info.thread = thread;
1349 /* Called when we're not longer stepping over a breakpoint / an
1350 instruction, so all breakpoints are free to be (re)inserted. */
1353 clear_step_over_info (void)
1356 fprintf_unfiltered (gdb_stdlog,
1357 "infrun: clear_step_over_info\n");
1358 step_over_info.aspace = NULL;
1359 step_over_info.address = 0;
1360 step_over_info.nonsteppable_watchpoint_p = 0;
1361 step_over_info.thread = -1;
1367 stepping_past_instruction_at (struct address_space *aspace,
1370 return (step_over_info.aspace != NULL
1371 && breakpoint_address_match (aspace, address,
1372 step_over_info.aspace,
1373 step_over_info.address));
1379 thread_is_stepping_over_breakpoint (int thread)
1381 return (step_over_info.thread != -1
1382 && thread == step_over_info.thread);
1388 stepping_past_nonsteppable_watchpoint (void)
1390 return step_over_info.nonsteppable_watchpoint_p;
1393 /* Returns true if step-over info is valid. */
1396 step_over_info_valid_p (void)
1398 return (step_over_info.aspace != NULL
1399 || stepping_past_nonsteppable_watchpoint ());
1403 /* Displaced stepping. */
1405 /* In non-stop debugging mode, we must take special care to manage
1406 breakpoints properly; in particular, the traditional strategy for
1407 stepping a thread past a breakpoint it has hit is unsuitable.
1408 'Displaced stepping' is a tactic for stepping one thread past a
1409 breakpoint it has hit while ensuring that other threads running
1410 concurrently will hit the breakpoint as they should.
1412 The traditional way to step a thread T off a breakpoint in a
1413 multi-threaded program in all-stop mode is as follows:
1415 a0) Initially, all threads are stopped, and breakpoints are not
1417 a1) We single-step T, leaving breakpoints uninserted.
1418 a2) We insert breakpoints, and resume all threads.
1420 In non-stop debugging, however, this strategy is unsuitable: we
1421 don't want to have to stop all threads in the system in order to
1422 continue or step T past a breakpoint. Instead, we use displaced
1425 n0) Initially, T is stopped, other threads are running, and
1426 breakpoints are inserted.
1427 n1) We copy the instruction "under" the breakpoint to a separate
1428 location, outside the main code stream, making any adjustments
1429 to the instruction, register, and memory state as directed by
1431 n2) We single-step T over the instruction at its new location.
1432 n3) We adjust the resulting register and memory state as directed
1433 by T's architecture. This includes resetting T's PC to point
1434 back into the main instruction stream.
1437 This approach depends on the following gdbarch methods:
1439 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1440 indicate where to copy the instruction, and how much space must
1441 be reserved there. We use these in step n1.
1443 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1444 address, and makes any necessary adjustments to the instruction,
1445 register contents, and memory. We use this in step n1.
1447 - gdbarch_displaced_step_fixup adjusts registers and memory after
1448 we have successfuly single-stepped the instruction, to yield the
1449 same effect the instruction would have had if we had executed it
1450 at its original address. We use this in step n3.
1452 - gdbarch_displaced_step_free_closure provides cleanup.
1454 The gdbarch_displaced_step_copy_insn and
1455 gdbarch_displaced_step_fixup functions must be written so that
1456 copying an instruction with gdbarch_displaced_step_copy_insn,
1457 single-stepping across the copied instruction, and then applying
1458 gdbarch_displaced_insn_fixup should have the same effects on the
1459 thread's memory and registers as stepping the instruction in place
1460 would have. Exactly which responsibilities fall to the copy and
1461 which fall to the fixup is up to the author of those functions.
1463 See the comments in gdbarch.sh for details.
1465 Note that displaced stepping and software single-step cannot
1466 currently be used in combination, although with some care I think
1467 they could be made to. Software single-step works by placing
1468 breakpoints on all possible subsequent instructions; if the
1469 displaced instruction is a PC-relative jump, those breakpoints
1470 could fall in very strange places --- on pages that aren't
1471 executable, or at addresses that are not proper instruction
1472 boundaries. (We do generally let other threads run while we wait
1473 to hit the software single-step breakpoint, and they might
1474 encounter such a corrupted instruction.) One way to work around
1475 this would be to have gdbarch_displaced_step_copy_insn fully
1476 simulate the effect of PC-relative instructions (and return NULL)
1477 on architectures that use software single-stepping.
1479 In non-stop mode, we can have independent and simultaneous step
1480 requests, so more than one thread may need to simultaneously step
1481 over a breakpoint. The current implementation assumes there is
1482 only one scratch space per process. In this case, we have to
1483 serialize access to the scratch space. If thread A wants to step
1484 over a breakpoint, but we are currently waiting for some other
1485 thread to complete a displaced step, we leave thread A stopped and
1486 place it in the displaced_step_request_queue. Whenever a displaced
1487 step finishes, we pick the next thread in the queue and start a new
1488 displaced step operation on it. See displaced_step_prepare and
1489 displaced_step_fixup for details. */
1491 /* Per-inferior displaced stepping state. */
1492 struct displaced_step_inferior_state
1494 /* Pointer to next in linked list. */
1495 struct displaced_step_inferior_state *next;
1497 /* The process this displaced step state refers to. */
1500 /* True if preparing a displaced step ever failed. If so, we won't
1501 try displaced stepping for this inferior again. */
1504 /* If this is not null_ptid, this is the thread carrying out a
1505 displaced single-step in process PID. This thread's state will
1506 require fixing up once it has completed its step. */
1509 /* The architecture the thread had when we stepped it. */
1510 struct gdbarch *step_gdbarch;
1512 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1513 for post-step cleanup. */
1514 struct displaced_step_closure *step_closure;
1516 /* The address of the original instruction, and the copy we
1518 CORE_ADDR step_original, step_copy;
1520 /* Saved contents of copy area. */
1521 gdb_byte *step_saved_copy;
1524 /* The list of states of processes involved in displaced stepping
1526 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1528 /* Get the displaced stepping state of process PID. */
1530 static struct displaced_step_inferior_state *
1531 get_displaced_stepping_state (int pid)
1533 struct displaced_step_inferior_state *state;
1535 for (state = displaced_step_inferior_states;
1537 state = state->next)
1538 if (state->pid == pid)
1544 /* Returns true if any inferior has a thread doing a displaced
1548 displaced_step_in_progress_any_inferior (void)
1550 struct displaced_step_inferior_state *state;
1552 for (state = displaced_step_inferior_states;
1554 state = state->next)
1555 if (!ptid_equal (state->step_ptid, null_ptid))
1561 /* Return true if thread represented by PTID is doing a displaced
1565 displaced_step_in_progress_thread (ptid_t ptid)
1567 struct displaced_step_inferior_state *displaced;
1569 gdb_assert (!ptid_equal (ptid, null_ptid));
1571 displaced = get_displaced_stepping_state (ptid_get_pid (ptid));
1573 return (displaced != NULL && ptid_equal (displaced->step_ptid, ptid));
1576 /* Return true if process PID has a thread doing a displaced step. */
1579 displaced_step_in_progress (int pid)
1581 struct displaced_step_inferior_state *displaced;
1583 displaced = get_displaced_stepping_state (pid);
1584 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1590 /* Add a new displaced stepping state for process PID to the displaced
1591 stepping state list, or return a pointer to an already existing
1592 entry, if it already exists. Never returns NULL. */
1594 static struct displaced_step_inferior_state *
1595 add_displaced_stepping_state (int pid)
1597 struct displaced_step_inferior_state *state;
1599 for (state = displaced_step_inferior_states;
1601 state = state->next)
1602 if (state->pid == pid)
1605 state = XCNEW (struct displaced_step_inferior_state);
1607 state->next = displaced_step_inferior_states;
1608 displaced_step_inferior_states = state;
1613 /* If inferior is in displaced stepping, and ADDR equals to starting address
1614 of copy area, return corresponding displaced_step_closure. Otherwise,
1617 struct displaced_step_closure*
1618 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1620 struct displaced_step_inferior_state *displaced
1621 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1623 /* If checking the mode of displaced instruction in copy area. */
1624 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1625 && (displaced->step_copy == addr))
1626 return displaced->step_closure;
1631 /* Remove the displaced stepping state of process PID. */
1634 remove_displaced_stepping_state (int pid)
1636 struct displaced_step_inferior_state *it, **prev_next_p;
1638 gdb_assert (pid != 0);
1640 it = displaced_step_inferior_states;
1641 prev_next_p = &displaced_step_inferior_states;
1646 *prev_next_p = it->next;
1651 prev_next_p = &it->next;
1657 infrun_inferior_exit (struct inferior *inf)
1659 remove_displaced_stepping_state (inf->pid);
1662 /* If ON, and the architecture supports it, GDB will use displaced
1663 stepping to step over breakpoints. If OFF, or if the architecture
1664 doesn't support it, GDB will instead use the traditional
1665 hold-and-step approach. If AUTO (which is the default), GDB will
1666 decide which technique to use to step over breakpoints depending on
1667 which of all-stop or non-stop mode is active --- displaced stepping
1668 in non-stop mode; hold-and-step in all-stop mode. */
1670 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1673 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1674 struct cmd_list_element *c,
1677 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1678 fprintf_filtered (file,
1679 _("Debugger's willingness to use displaced stepping "
1680 "to step over breakpoints is %s (currently %s).\n"),
1681 value, target_is_non_stop_p () ? "on" : "off");
1683 fprintf_filtered (file,
1684 _("Debugger's willingness to use displaced stepping "
1685 "to step over breakpoints is %s.\n"), value);
1688 /* Return non-zero if displaced stepping can/should be used to step
1689 over breakpoints of thread TP. */
1692 use_displaced_stepping (struct thread_info *tp)
1694 struct regcache *regcache = get_thread_regcache (tp->ptid);
1695 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1696 struct displaced_step_inferior_state *displaced_state;
1698 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
1700 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1701 && target_is_non_stop_p ())
1702 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1703 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1704 && find_record_target () == NULL
1705 && (displaced_state == NULL
1706 || !displaced_state->failed_before));
1709 /* Clean out any stray displaced stepping state. */
1711 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1713 /* Indicate that there is no cleanup pending. */
1714 displaced->step_ptid = null_ptid;
1716 xfree (displaced->step_closure);
1717 displaced->step_closure = NULL;
1721 displaced_step_clear_cleanup (void *arg)
1723 struct displaced_step_inferior_state *state
1724 = (struct displaced_step_inferior_state *) arg;
1726 displaced_step_clear (state);
1729 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1731 displaced_step_dump_bytes (struct ui_file *file,
1732 const gdb_byte *buf,
1737 for (i = 0; i < len; i++)
1738 fprintf_unfiltered (file, "%02x ", buf[i]);
1739 fputs_unfiltered ("\n", file);
1742 /* Prepare to single-step, using displaced stepping.
1744 Note that we cannot use displaced stepping when we have a signal to
1745 deliver. If we have a signal to deliver and an instruction to step
1746 over, then after the step, there will be no indication from the
1747 target whether the thread entered a signal handler or ignored the
1748 signal and stepped over the instruction successfully --- both cases
1749 result in a simple SIGTRAP. In the first case we mustn't do a
1750 fixup, and in the second case we must --- but we can't tell which.
1751 Comments in the code for 'random signals' in handle_inferior_event
1752 explain how we handle this case instead.
1754 Returns 1 if preparing was successful -- this thread is going to be
1755 stepped now; 0 if displaced stepping this thread got queued; or -1
1756 if this instruction can't be displaced stepped. */
1759 displaced_step_prepare_throw (ptid_t ptid)
1761 struct cleanup *ignore_cleanups;
1762 struct thread_info *tp = find_thread_ptid (ptid);
1763 struct regcache *regcache = get_thread_regcache (ptid);
1764 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1765 struct address_space *aspace = get_regcache_aspace (regcache);
1766 CORE_ADDR original, copy;
1768 struct displaced_step_closure *closure;
1769 struct displaced_step_inferior_state *displaced;
1772 /* We should never reach this function if the architecture does not
1773 support displaced stepping. */
1774 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1776 /* Nor if the thread isn't meant to step over a breakpoint. */
1777 gdb_assert (tp->control.trap_expected);
1779 /* Disable range stepping while executing in the scratch pad. We
1780 want a single-step even if executing the displaced instruction in
1781 the scratch buffer lands within the stepping range (e.g., a
1783 tp->control.may_range_step = 0;
1785 /* We have to displaced step one thread at a time, as we only have
1786 access to a single scratch space per inferior. */
1788 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1790 if (!ptid_equal (displaced->step_ptid, null_ptid))
1792 /* Already waiting for a displaced step to finish. Defer this
1793 request and place in queue. */
1795 if (debug_displaced)
1796 fprintf_unfiltered (gdb_stdlog,
1797 "displaced: deferring step of %s\n",
1798 target_pid_to_str (ptid));
1800 thread_step_over_chain_enqueue (tp);
1805 if (debug_displaced)
1806 fprintf_unfiltered (gdb_stdlog,
1807 "displaced: stepping %s now\n",
1808 target_pid_to_str (ptid));
1811 displaced_step_clear (displaced);
1813 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1814 inferior_ptid = ptid;
1816 original = regcache_read_pc (regcache);
1818 copy = gdbarch_displaced_step_location (gdbarch);
1819 len = gdbarch_max_insn_length (gdbarch);
1821 if (breakpoint_in_range_p (aspace, copy, len))
1823 /* There's a breakpoint set in the scratch pad location range
1824 (which is usually around the entry point). We'd either
1825 install it before resuming, which would overwrite/corrupt the
1826 scratch pad, or if it was already inserted, this displaced
1827 step would overwrite it. The latter is OK in the sense that
1828 we already assume that no thread is going to execute the code
1829 in the scratch pad range (after initial startup) anyway, but
1830 the former is unacceptable. Simply punt and fallback to
1831 stepping over this breakpoint in-line. */
1832 if (debug_displaced)
1834 fprintf_unfiltered (gdb_stdlog,
1835 "displaced: breakpoint set in scratch pad. "
1836 "Stepping over breakpoint in-line instead.\n");
1842 /* Save the original contents of the copy area. */
1843 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1844 ignore_cleanups = make_cleanup (free_current_contents,
1845 &displaced->step_saved_copy);
1846 status = target_read_memory (copy, displaced->step_saved_copy, len);
1848 throw_error (MEMORY_ERROR,
1849 _("Error accessing memory address %s (%s) for "
1850 "displaced-stepping scratch space."),
1851 paddress (gdbarch, copy), safe_strerror (status));
1852 if (debug_displaced)
1854 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1855 paddress (gdbarch, copy));
1856 displaced_step_dump_bytes (gdb_stdlog,
1857 displaced->step_saved_copy,
1861 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1862 original, copy, regcache);
1863 if (closure == NULL)
1865 /* The architecture doesn't know how or want to displaced step
1866 this instruction or instruction sequence. Fallback to
1867 stepping over the breakpoint in-line. */
1868 do_cleanups (ignore_cleanups);
1872 /* Save the information we need to fix things up if the step
1874 displaced->step_ptid = ptid;
1875 displaced->step_gdbarch = gdbarch;
1876 displaced->step_closure = closure;
1877 displaced->step_original = original;
1878 displaced->step_copy = copy;
1880 make_cleanup (displaced_step_clear_cleanup, displaced);
1882 /* Resume execution at the copy. */
1883 regcache_write_pc (regcache, copy);
1885 discard_cleanups (ignore_cleanups);
1887 if (debug_displaced)
1888 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1889 paddress (gdbarch, copy));
1894 /* Wrapper for displaced_step_prepare_throw that disabled further
1895 attempts at displaced stepping if we get a memory error. */
1898 displaced_step_prepare (ptid_t ptid)
1904 prepared = displaced_step_prepare_throw (ptid);
1906 CATCH (ex, RETURN_MASK_ERROR)
1908 struct displaced_step_inferior_state *displaced_state;
1910 if (ex.error != MEMORY_ERROR
1911 && ex.error != NOT_SUPPORTED_ERROR)
1912 throw_exception (ex);
1916 fprintf_unfiltered (gdb_stdlog,
1917 "infrun: disabling displaced stepping: %s\n",
1921 /* Be verbose if "set displaced-stepping" is "on", silent if
1923 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1925 warning (_("disabling displaced stepping: %s"),
1929 /* Disable further displaced stepping attempts. */
1931 = get_displaced_stepping_state (ptid_get_pid (ptid));
1932 displaced_state->failed_before = 1;
1940 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1941 const gdb_byte *myaddr, int len)
1943 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1945 inferior_ptid = ptid;
1946 write_memory (memaddr, myaddr, len);
1949 /* Restore the contents of the copy area for thread PTID. */
1952 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1955 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1957 write_memory_ptid (ptid, displaced->step_copy,
1958 displaced->step_saved_copy, len);
1959 if (debug_displaced)
1960 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1961 target_pid_to_str (ptid),
1962 paddress (displaced->step_gdbarch,
1963 displaced->step_copy));
1966 /* If we displaced stepped an instruction successfully, adjust
1967 registers and memory to yield the same effect the instruction would
1968 have had if we had executed it at its original address, and return
1969 1. If the instruction didn't complete, relocate the PC and return
1970 -1. If the thread wasn't displaced stepping, return 0. */
1973 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1975 struct cleanup *old_cleanups;
1976 struct displaced_step_inferior_state *displaced
1977 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1980 /* Was any thread of this process doing a displaced step? */
1981 if (displaced == NULL)
1984 /* Was this event for the pid we displaced? */
1985 if (ptid_equal (displaced->step_ptid, null_ptid)
1986 || ! ptid_equal (displaced->step_ptid, event_ptid))
1989 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1991 displaced_step_restore (displaced, displaced->step_ptid);
1993 /* Fixup may need to read memory/registers. Switch to the thread
1994 that we're fixing up. Also, target_stopped_by_watchpoint checks
1995 the current thread. */
1996 switch_to_thread (event_ptid);
1998 /* Did the instruction complete successfully? */
1999 if (signal == GDB_SIGNAL_TRAP
2000 && !(target_stopped_by_watchpoint ()
2001 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
2002 || target_have_steppable_watchpoint)))
2004 /* Fix up the resulting state. */
2005 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
2006 displaced->step_closure,
2007 displaced->step_original,
2008 displaced->step_copy,
2009 get_thread_regcache (displaced->step_ptid));
2014 /* Since the instruction didn't complete, all we can do is
2016 struct regcache *regcache = get_thread_regcache (event_ptid);
2017 CORE_ADDR pc = regcache_read_pc (regcache);
2019 pc = displaced->step_original + (pc - displaced->step_copy);
2020 regcache_write_pc (regcache, pc);
2024 do_cleanups (old_cleanups);
2026 displaced->step_ptid = null_ptid;
2031 /* Data to be passed around while handling an event. This data is
2032 discarded between events. */
2033 struct execution_control_state
2036 /* The thread that got the event, if this was a thread event; NULL
2038 struct thread_info *event_thread;
2040 struct target_waitstatus ws;
2041 int stop_func_filled_in;
2042 CORE_ADDR stop_func_start;
2043 CORE_ADDR stop_func_end;
2044 const char *stop_func_name;
2047 /* True if the event thread hit the single-step breakpoint of
2048 another thread. Thus the event doesn't cause a stop, the thread
2049 needs to be single-stepped past the single-step breakpoint before
2050 we can switch back to the original stepping thread. */
2051 int hit_singlestep_breakpoint;
2054 /* Clear ECS and set it to point at TP. */
2057 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2059 memset (ecs, 0, sizeof (*ecs));
2060 ecs->event_thread = tp;
2061 ecs->ptid = tp->ptid;
2064 static void keep_going_pass_signal (struct execution_control_state *ecs);
2065 static void prepare_to_wait (struct execution_control_state *ecs);
2066 static int keep_going_stepped_thread (struct thread_info *tp);
2067 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2069 /* Are there any pending step-over requests? If so, run all we can
2070 now and return true. Otherwise, return false. */
2073 start_step_over (void)
2075 struct thread_info *tp, *next;
2077 /* Don't start a new step-over if we already have an in-line
2078 step-over operation ongoing. */
2079 if (step_over_info_valid_p ())
2082 for (tp = step_over_queue_head; tp != NULL; tp = next)
2084 struct execution_control_state ecss;
2085 struct execution_control_state *ecs = &ecss;
2086 step_over_what step_what;
2087 int must_be_in_line;
2089 gdb_assert (!tp->stop_requested);
2091 next = thread_step_over_chain_next (tp);
2093 /* If this inferior already has a displaced step in process,
2094 don't start a new one. */
2095 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2098 step_what = thread_still_needs_step_over (tp);
2099 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2100 || ((step_what & STEP_OVER_BREAKPOINT)
2101 && !use_displaced_stepping (tp)));
2103 /* We currently stop all threads of all processes to step-over
2104 in-line. If we need to start a new in-line step-over, let
2105 any pending displaced steps finish first. */
2106 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2109 thread_step_over_chain_remove (tp);
2111 if (step_over_queue_head == NULL)
2114 fprintf_unfiltered (gdb_stdlog,
2115 "infrun: step-over queue now empty\n");
2118 if (tp->control.trap_expected
2122 internal_error (__FILE__, __LINE__,
2123 "[%s] has inconsistent state: "
2124 "trap_expected=%d, resumed=%d, executing=%d\n",
2125 target_pid_to_str (tp->ptid),
2126 tp->control.trap_expected,
2132 fprintf_unfiltered (gdb_stdlog,
2133 "infrun: resuming [%s] for step-over\n",
2134 target_pid_to_str (tp->ptid));
2136 /* keep_going_pass_signal skips the step-over if the breakpoint
2137 is no longer inserted. In all-stop, we want to keep looking
2138 for a thread that needs a step-over instead of resuming TP,
2139 because we wouldn't be able to resume anything else until the
2140 target stops again. In non-stop, the resume always resumes
2141 only TP, so it's OK to let the thread resume freely. */
2142 if (!target_is_non_stop_p () && !step_what)
2145 switch_to_thread (tp->ptid);
2146 reset_ecs (ecs, tp);
2147 keep_going_pass_signal (ecs);
2149 if (!ecs->wait_some_more)
2150 error (_("Command aborted."));
2152 gdb_assert (tp->resumed);
2154 /* If we started a new in-line step-over, we're done. */
2155 if (step_over_info_valid_p ())
2157 gdb_assert (tp->control.trap_expected);
2161 if (!target_is_non_stop_p ())
2163 /* On all-stop, shouldn't have resumed unless we needed a
2165 gdb_assert (tp->control.trap_expected
2166 || tp->step_after_step_resume_breakpoint);
2168 /* With remote targets (at least), in all-stop, we can't
2169 issue any further remote commands until the program stops
2174 /* Either the thread no longer needed a step-over, or a new
2175 displaced stepping sequence started. Even in the latter
2176 case, continue looking. Maybe we can also start another
2177 displaced step on a thread of other process. */
2183 /* Update global variables holding ptids to hold NEW_PTID if they were
2184 holding OLD_PTID. */
2186 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2188 struct displaced_step_inferior_state *displaced;
2190 if (ptid_equal (inferior_ptid, old_ptid))
2191 inferior_ptid = new_ptid;
2193 for (displaced = displaced_step_inferior_states;
2195 displaced = displaced->next)
2197 if (ptid_equal (displaced->step_ptid, old_ptid))
2198 displaced->step_ptid = new_ptid;
2205 /* Things to clean up if we QUIT out of resume (). */
2207 resume_cleanups (void *ignore)
2209 if (!ptid_equal (inferior_ptid, null_ptid))
2210 delete_single_step_breakpoints (inferior_thread ());
2215 static const char schedlock_off[] = "off";
2216 static const char schedlock_on[] = "on";
2217 static const char schedlock_step[] = "step";
2218 static const char schedlock_replay[] = "replay";
2219 static const char *const scheduler_enums[] = {
2226 static const char *scheduler_mode = schedlock_replay;
2228 show_scheduler_mode (struct ui_file *file, int from_tty,
2229 struct cmd_list_element *c, const char *value)
2231 fprintf_filtered (file,
2232 _("Mode for locking scheduler "
2233 "during execution is \"%s\".\n"),
2238 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2240 if (!target_can_lock_scheduler)
2242 scheduler_mode = schedlock_off;
2243 error (_("Target '%s' cannot support this command."), target_shortname);
2247 /* True if execution commands resume all threads of all processes by
2248 default; otherwise, resume only threads of the current inferior
2250 int sched_multi = 0;
2252 /* Try to setup for software single stepping over the specified location.
2253 Return 1 if target_resume() should use hardware single step.
2255 GDBARCH the current gdbarch.
2256 PC the location to step over. */
2259 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2263 if (execution_direction == EXEC_FORWARD
2264 && gdbarch_software_single_step_p (gdbarch))
2265 hw_step = !insert_single_step_breakpoints (gdbarch);
2273 user_visible_resume_ptid (int step)
2279 /* With non-stop mode on, threads are always handled
2281 resume_ptid = inferior_ptid;
2283 else if ((scheduler_mode == schedlock_on)
2284 || (scheduler_mode == schedlock_step && step))
2286 /* User-settable 'scheduler' mode requires solo thread
2288 resume_ptid = inferior_ptid;
2290 else if ((scheduler_mode == schedlock_replay)
2291 && target_record_will_replay (minus_one_ptid, execution_direction))
2293 /* User-settable 'scheduler' mode requires solo thread resume in replay
2295 resume_ptid = inferior_ptid;
2297 else if (!sched_multi && target_supports_multi_process ())
2299 /* Resume all threads of the current process (and none of other
2301 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2305 /* Resume all threads of all processes. */
2306 resume_ptid = RESUME_ALL;
2312 /* Return a ptid representing the set of threads that we will resume,
2313 in the perspective of the target, assuming run control handling
2314 does not require leaving some threads stopped (e.g., stepping past
2315 breakpoint). USER_STEP indicates whether we're about to start the
2316 target for a stepping command. */
2319 internal_resume_ptid (int user_step)
2321 /* In non-stop, we always control threads individually. Note that
2322 the target may always work in non-stop mode even with "set
2323 non-stop off", in which case user_visible_resume_ptid could
2324 return a wildcard ptid. */
2325 if (target_is_non_stop_p ())
2326 return inferior_ptid;
2328 return user_visible_resume_ptid (user_step);
2331 /* Wrapper for target_resume, that handles infrun-specific
2335 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2337 struct thread_info *tp = inferior_thread ();
2339 gdb_assert (!tp->stop_requested);
2341 /* Install inferior's terminal modes. */
2342 target_terminal::inferior ();
2344 /* Avoid confusing the next resume, if the next stop/resume
2345 happens to apply to another thread. */
2346 tp->suspend.stop_signal = GDB_SIGNAL_0;
2348 /* Advise target which signals may be handled silently.
2350 If we have removed breakpoints because we are stepping over one
2351 in-line (in any thread), we need to receive all signals to avoid
2352 accidentally skipping a breakpoint during execution of a signal
2355 Likewise if we're displaced stepping, otherwise a trap for a
2356 breakpoint in a signal handler might be confused with the
2357 displaced step finishing. We don't make the displaced_step_fixup
2358 step distinguish the cases instead, because:
2360 - a backtrace while stopped in the signal handler would show the
2361 scratch pad as frame older than the signal handler, instead of
2362 the real mainline code.
2364 - when the thread is later resumed, the signal handler would
2365 return to the scratch pad area, which would no longer be
2367 if (step_over_info_valid_p ()
2368 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2369 target_pass_signals (0, NULL);
2371 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2373 target_resume (resume_ptid, step, sig);
2375 target_commit_resume ();
2378 /* Resume the inferior, but allow a QUIT. This is useful if the user
2379 wants to interrupt some lengthy single-stepping operation
2380 (for child processes, the SIGINT goes to the inferior, and so
2381 we get a SIGINT random_signal, but for remote debugging and perhaps
2382 other targets, that's not true).
2384 SIG is the signal to give the inferior (zero for none). */
2386 resume (enum gdb_signal sig)
2388 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2389 struct regcache *regcache = get_current_regcache ();
2390 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2391 struct thread_info *tp = inferior_thread ();
2392 CORE_ADDR pc = regcache_read_pc (regcache);
2393 struct address_space *aspace = get_regcache_aspace (regcache);
2395 /* This represents the user's step vs continue request. When
2396 deciding whether "set scheduler-locking step" applies, it's the
2397 user's intention that counts. */
2398 const int user_step = tp->control.stepping_command;
2399 /* This represents what we'll actually request the target to do.
2400 This can decay from a step to a continue, if e.g., we need to
2401 implement single-stepping with breakpoints (software
2405 gdb_assert (!tp->stop_requested);
2406 gdb_assert (!thread_is_in_step_over_chain (tp));
2410 if (tp->suspend.waitstatus_pending_p)
2415 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2417 fprintf_unfiltered (gdb_stdlog,
2418 "infrun: resume: thread %s has pending wait "
2419 "status %s (currently_stepping=%d).\n",
2420 target_pid_to_str (tp->ptid), statstr.c_str (),
2421 currently_stepping (tp));
2426 /* FIXME: What should we do if we are supposed to resume this
2427 thread with a signal? Maybe we should maintain a queue of
2428 pending signals to deliver. */
2429 if (sig != GDB_SIGNAL_0)
2431 warning (_("Couldn't deliver signal %s to %s."),
2432 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2435 tp->suspend.stop_signal = GDB_SIGNAL_0;
2436 discard_cleanups (old_cleanups);
2438 if (target_can_async_p ())
2443 tp->stepped_breakpoint = 0;
2445 /* Depends on stepped_breakpoint. */
2446 step = currently_stepping (tp);
2448 if (current_inferior ()->waiting_for_vfork_done)
2450 /* Don't try to single-step a vfork parent that is waiting for
2451 the child to get out of the shared memory region (by exec'ing
2452 or exiting). This is particularly important on software
2453 single-step archs, as the child process would trip on the
2454 software single step breakpoint inserted for the parent
2455 process. Since the parent will not actually execute any
2456 instruction until the child is out of the shared region (such
2457 are vfork's semantics), it is safe to simply continue it.
2458 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2459 the parent, and tell it to `keep_going', which automatically
2460 re-sets it stepping. */
2462 fprintf_unfiltered (gdb_stdlog,
2463 "infrun: resume : clear step\n");
2468 fprintf_unfiltered (gdb_stdlog,
2469 "infrun: resume (step=%d, signal=%s), "
2470 "trap_expected=%d, current thread [%s] at %s\n",
2471 step, gdb_signal_to_symbol_string (sig),
2472 tp->control.trap_expected,
2473 target_pid_to_str (inferior_ptid),
2474 paddress (gdbarch, pc));
2476 /* Normally, by the time we reach `resume', the breakpoints are either
2477 removed or inserted, as appropriate. The exception is if we're sitting
2478 at a permanent breakpoint; we need to step over it, but permanent
2479 breakpoints can't be removed. So we have to test for it here. */
2480 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2482 if (sig != GDB_SIGNAL_0)
2484 /* We have a signal to pass to the inferior. The resume
2485 may, or may not take us to the signal handler. If this
2486 is a step, we'll need to stop in the signal handler, if
2487 there's one, (if the target supports stepping into
2488 handlers), or in the next mainline instruction, if
2489 there's no handler. If this is a continue, we need to be
2490 sure to run the handler with all breakpoints inserted.
2491 In all cases, set a breakpoint at the current address
2492 (where the handler returns to), and once that breakpoint
2493 is hit, resume skipping the permanent breakpoint. If
2494 that breakpoint isn't hit, then we've stepped into the
2495 signal handler (or hit some other event). We'll delete
2496 the step-resume breakpoint then. */
2499 fprintf_unfiltered (gdb_stdlog,
2500 "infrun: resume: skipping permanent breakpoint, "
2501 "deliver signal first\n");
2503 clear_step_over_info ();
2504 tp->control.trap_expected = 0;
2506 if (tp->control.step_resume_breakpoint == NULL)
2508 /* Set a "high-priority" step-resume, as we don't want
2509 user breakpoints at PC to trigger (again) when this
2511 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2512 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2514 tp->step_after_step_resume_breakpoint = step;
2517 insert_breakpoints ();
2521 /* There's no signal to pass, we can go ahead and skip the
2522 permanent breakpoint manually. */
2524 fprintf_unfiltered (gdb_stdlog,
2525 "infrun: resume: skipping permanent breakpoint\n");
2526 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2527 /* Update pc to reflect the new address from which we will
2528 execute instructions. */
2529 pc = regcache_read_pc (regcache);
2533 /* We've already advanced the PC, so the stepping part
2534 is done. Now we need to arrange for a trap to be
2535 reported to handle_inferior_event. Set a breakpoint
2536 at the current PC, and run to it. Don't update
2537 prev_pc, because if we end in
2538 switch_back_to_stepped_thread, we want the "expected
2539 thread advanced also" branch to be taken. IOW, we
2540 don't want this thread to step further from PC
2542 gdb_assert (!step_over_info_valid_p ());
2543 insert_single_step_breakpoint (gdbarch, aspace, pc);
2544 insert_breakpoints ();
2546 resume_ptid = internal_resume_ptid (user_step);
2547 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2548 discard_cleanups (old_cleanups);
2555 /* If we have a breakpoint to step over, make sure to do a single
2556 step only. Same if we have software watchpoints. */
2557 if (tp->control.trap_expected || bpstat_should_step ())
2558 tp->control.may_range_step = 0;
2560 /* If enabled, step over breakpoints by executing a copy of the
2561 instruction at a different address.
2563 We can't use displaced stepping when we have a signal to deliver;
2564 the comments for displaced_step_prepare explain why. The
2565 comments in the handle_inferior event for dealing with 'random
2566 signals' explain what we do instead.
2568 We can't use displaced stepping when we are waiting for vfork_done
2569 event, displaced stepping breaks the vfork child similarly as single
2570 step software breakpoint. */
2571 if (tp->control.trap_expected
2572 && use_displaced_stepping (tp)
2573 && !step_over_info_valid_p ()
2574 && sig == GDB_SIGNAL_0
2575 && !current_inferior ()->waiting_for_vfork_done)
2577 int prepared = displaced_step_prepare (inferior_ptid);
2582 fprintf_unfiltered (gdb_stdlog,
2583 "Got placed in step-over queue\n");
2585 tp->control.trap_expected = 0;
2586 discard_cleanups (old_cleanups);
2589 else if (prepared < 0)
2591 /* Fallback to stepping over the breakpoint in-line. */
2593 if (target_is_non_stop_p ())
2594 stop_all_threads ();
2596 set_step_over_info (get_regcache_aspace (regcache),
2597 regcache_read_pc (regcache), 0, tp->global_num);
2599 step = maybe_software_singlestep (gdbarch, pc);
2601 insert_breakpoints ();
2603 else if (prepared > 0)
2605 struct displaced_step_inferior_state *displaced;
2607 /* Update pc to reflect the new address from which we will
2608 execute instructions due to displaced stepping. */
2609 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2611 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2612 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2613 displaced->step_closure);
2617 /* Do we need to do it the hard way, w/temp breakpoints? */
2619 step = maybe_software_singlestep (gdbarch, pc);
2621 /* Currently, our software single-step implementation leads to different
2622 results than hardware single-stepping in one situation: when stepping
2623 into delivering a signal which has an associated signal handler,
2624 hardware single-step will stop at the first instruction of the handler,
2625 while software single-step will simply skip execution of the handler.
2627 For now, this difference in behavior is accepted since there is no
2628 easy way to actually implement single-stepping into a signal handler
2629 without kernel support.
2631 However, there is one scenario where this difference leads to follow-on
2632 problems: if we're stepping off a breakpoint by removing all breakpoints
2633 and then single-stepping. In this case, the software single-step
2634 behavior means that even if there is a *breakpoint* in the signal
2635 handler, GDB still would not stop.
2637 Fortunately, we can at least fix this particular issue. We detect
2638 here the case where we are about to deliver a signal while software
2639 single-stepping with breakpoints removed. In this situation, we
2640 revert the decisions to remove all breakpoints and insert single-
2641 step breakpoints, and instead we install a step-resume breakpoint
2642 at the current address, deliver the signal without stepping, and
2643 once we arrive back at the step-resume breakpoint, actually step
2644 over the breakpoint we originally wanted to step over. */
2645 if (thread_has_single_step_breakpoints_set (tp)
2646 && sig != GDB_SIGNAL_0
2647 && step_over_info_valid_p ())
2649 /* If we have nested signals or a pending signal is delivered
2650 immediately after a handler returns, might might already have
2651 a step-resume breakpoint set on the earlier handler. We cannot
2652 set another step-resume breakpoint; just continue on until the
2653 original breakpoint is hit. */
2654 if (tp->control.step_resume_breakpoint == NULL)
2656 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2657 tp->step_after_step_resume_breakpoint = 1;
2660 delete_single_step_breakpoints (tp);
2662 clear_step_over_info ();
2663 tp->control.trap_expected = 0;
2665 insert_breakpoints ();
2668 /* If STEP is set, it's a request to use hardware stepping
2669 facilities. But in that case, we should never
2670 use singlestep breakpoint. */
2671 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2673 /* Decide the set of threads to ask the target to resume. */
2674 if (tp->control.trap_expected)
2676 /* We're allowing a thread to run past a breakpoint it has
2677 hit, either by single-stepping the thread with the breakpoint
2678 removed, or by displaced stepping, with the breakpoint inserted.
2679 In the former case, we need to single-step only this thread,
2680 and keep others stopped, as they can miss this breakpoint if
2681 allowed to run. That's not really a problem for displaced
2682 stepping, but, we still keep other threads stopped, in case
2683 another thread is also stopped for a breakpoint waiting for
2684 its turn in the displaced stepping queue. */
2685 resume_ptid = inferior_ptid;
2688 resume_ptid = internal_resume_ptid (user_step);
2690 if (execution_direction != EXEC_REVERSE
2691 && step && breakpoint_inserted_here_p (aspace, pc))
2693 /* There are two cases where we currently need to step a
2694 breakpoint instruction when we have a signal to deliver:
2696 - See handle_signal_stop where we handle random signals that
2697 could take out us out of the stepping range. Normally, in
2698 that case we end up continuing (instead of stepping) over the
2699 signal handler with a breakpoint at PC, but there are cases
2700 where we should _always_ single-step, even if we have a
2701 step-resume breakpoint, like when a software watchpoint is
2702 set. Assuming single-stepping and delivering a signal at the
2703 same time would takes us to the signal handler, then we could
2704 have removed the breakpoint at PC to step over it. However,
2705 some hardware step targets (like e.g., Mac OS) can't step
2706 into signal handlers, and for those, we need to leave the
2707 breakpoint at PC inserted, as otherwise if the handler
2708 recurses and executes PC again, it'll miss the breakpoint.
2709 So we leave the breakpoint inserted anyway, but we need to
2710 record that we tried to step a breakpoint instruction, so
2711 that adjust_pc_after_break doesn't end up confused.
2713 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2714 in one thread after another thread that was stepping had been
2715 momentarily paused for a step-over. When we re-resume the
2716 stepping thread, it may be resumed from that address with a
2717 breakpoint that hasn't trapped yet. Seen with
2718 gdb.threads/non-stop-fair-events.exp, on targets that don't
2719 do displaced stepping. */
2722 fprintf_unfiltered (gdb_stdlog,
2723 "infrun: resume: [%s] stepped breakpoint\n",
2724 target_pid_to_str (tp->ptid));
2726 tp->stepped_breakpoint = 1;
2728 /* Most targets can step a breakpoint instruction, thus
2729 executing it normally. But if this one cannot, just
2730 continue and we will hit it anyway. */
2731 if (gdbarch_cannot_step_breakpoint (gdbarch))
2736 && tp->control.trap_expected
2737 && use_displaced_stepping (tp)
2738 && !step_over_info_valid_p ())
2740 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2741 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2742 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2745 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2746 paddress (resume_gdbarch, actual_pc));
2747 read_memory (actual_pc, buf, sizeof (buf));
2748 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2751 if (tp->control.may_range_step)
2753 /* If we're resuming a thread with the PC out of the step
2754 range, then we're doing some nested/finer run control
2755 operation, like stepping the thread out of the dynamic
2756 linker or the displaced stepping scratch pad. We
2757 shouldn't have allowed a range step then. */
2758 gdb_assert (pc_in_thread_step_range (pc, tp));
2761 do_target_resume (resume_ptid, step, sig);
2763 discard_cleanups (old_cleanups);
2770 /* Counter that tracks number of user visible stops. This can be used
2771 to tell whether a command has proceeded the inferior past the
2772 current location. This allows e.g., inferior function calls in
2773 breakpoint commands to not interrupt the command list. When the
2774 call finishes successfully, the inferior is standing at the same
2775 breakpoint as if nothing happened (and so we don't call
2777 static ULONGEST current_stop_id;
2784 return current_stop_id;
2787 /* Called when we report a user visible stop. */
2795 /* Clear out all variables saying what to do when inferior is continued.
2796 First do this, then set the ones you want, then call `proceed'. */
2799 clear_proceed_status_thread (struct thread_info *tp)
2802 fprintf_unfiltered (gdb_stdlog,
2803 "infrun: clear_proceed_status_thread (%s)\n",
2804 target_pid_to_str (tp->ptid));
2806 /* If we're starting a new sequence, then the previous finished
2807 single-step is no longer relevant. */
2808 if (tp->suspend.waitstatus_pending_p)
2810 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2813 fprintf_unfiltered (gdb_stdlog,
2814 "infrun: clear_proceed_status: pending "
2815 "event of %s was a finished step. "
2817 target_pid_to_str (tp->ptid));
2819 tp->suspend.waitstatus_pending_p = 0;
2820 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2822 else if (debug_infrun)
2825 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2827 fprintf_unfiltered (gdb_stdlog,
2828 "infrun: clear_proceed_status_thread: thread %s "
2829 "has pending wait status %s "
2830 "(currently_stepping=%d).\n",
2831 target_pid_to_str (tp->ptid), statstr.c_str (),
2832 currently_stepping (tp));
2836 /* If this signal should not be seen by program, give it zero.
2837 Used for debugging signals. */
2838 if (!signal_pass_state (tp->suspend.stop_signal))
2839 tp->suspend.stop_signal = GDB_SIGNAL_0;
2841 thread_fsm_delete (tp->thread_fsm);
2842 tp->thread_fsm = NULL;
2844 tp->control.trap_expected = 0;
2845 tp->control.step_range_start = 0;
2846 tp->control.step_range_end = 0;
2847 tp->control.may_range_step = 0;
2848 tp->control.step_frame_id = null_frame_id;
2849 tp->control.step_stack_frame_id = null_frame_id;
2850 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2851 tp->control.step_start_function = NULL;
2852 tp->stop_requested = 0;
2854 tp->control.stop_step = 0;
2856 tp->control.proceed_to_finish = 0;
2858 tp->control.stepping_command = 0;
2860 /* Discard any remaining commands or status from previous stop. */
2861 bpstat_clear (&tp->control.stop_bpstat);
2865 clear_proceed_status (int step)
2867 /* With scheduler-locking replay, stop replaying other threads if we're
2868 not replaying the user-visible resume ptid.
2870 This is a convenience feature to not require the user to explicitly
2871 stop replaying the other threads. We're assuming that the user's
2872 intent is to resume tracing the recorded process. */
2873 if (!non_stop && scheduler_mode == schedlock_replay
2874 && target_record_is_replaying (minus_one_ptid)
2875 && !target_record_will_replay (user_visible_resume_ptid (step),
2876 execution_direction))
2877 target_record_stop_replaying ();
2881 struct thread_info *tp;
2884 resume_ptid = user_visible_resume_ptid (step);
2886 /* In all-stop mode, delete the per-thread status of all threads
2887 we're about to resume, implicitly and explicitly. */
2888 ALL_NON_EXITED_THREADS (tp)
2890 if (!ptid_match (tp->ptid, resume_ptid))
2892 clear_proceed_status_thread (tp);
2896 if (!ptid_equal (inferior_ptid, null_ptid))
2898 struct inferior *inferior;
2902 /* If in non-stop mode, only delete the per-thread status of
2903 the current thread. */
2904 clear_proceed_status_thread (inferior_thread ());
2907 inferior = current_inferior ();
2908 inferior->control.stop_soon = NO_STOP_QUIETLY;
2911 observer_notify_about_to_proceed ();
2914 /* Returns true if TP is still stopped at a breakpoint that needs
2915 stepping-over in order to make progress. If the breakpoint is gone
2916 meanwhile, we can skip the whole step-over dance. */
2919 thread_still_needs_step_over_bp (struct thread_info *tp)
2921 if (tp->stepping_over_breakpoint)
2923 struct regcache *regcache = get_thread_regcache (tp->ptid);
2925 if (breakpoint_here_p (get_regcache_aspace (regcache),
2926 regcache_read_pc (regcache))
2927 == ordinary_breakpoint_here)
2930 tp->stepping_over_breakpoint = 0;
2936 /* Check whether thread TP still needs to start a step-over in order
2937 to make progress when resumed. Returns an bitwise or of enum
2938 step_over_what bits, indicating what needs to be stepped over. */
2940 static step_over_what
2941 thread_still_needs_step_over (struct thread_info *tp)
2943 step_over_what what = 0;
2945 if (thread_still_needs_step_over_bp (tp))
2946 what |= STEP_OVER_BREAKPOINT;
2948 if (tp->stepping_over_watchpoint
2949 && !target_have_steppable_watchpoint)
2950 what |= STEP_OVER_WATCHPOINT;
2955 /* Returns true if scheduler locking applies. STEP indicates whether
2956 we're about to do a step/next-like command to a thread. */
2959 schedlock_applies (struct thread_info *tp)
2961 return (scheduler_mode == schedlock_on
2962 || (scheduler_mode == schedlock_step
2963 && tp->control.stepping_command)
2964 || (scheduler_mode == schedlock_replay
2965 && target_record_will_replay (minus_one_ptid,
2966 execution_direction)));
2969 /* Basic routine for continuing the program in various fashions.
2971 ADDR is the address to resume at, or -1 for resume where stopped.
2972 SIGGNAL is the signal to give it, or 0 for none,
2973 or -1 for act according to how it stopped.
2974 STEP is nonzero if should trap after one instruction.
2975 -1 means return after that and print nothing.
2976 You should probably set various step_... variables
2977 before calling here, if you are stepping.
2979 You should call clear_proceed_status before calling proceed. */
2982 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2984 struct regcache *regcache;
2985 struct gdbarch *gdbarch;
2986 struct thread_info *tp;
2988 struct address_space *aspace;
2990 struct execution_control_state ecss;
2991 struct execution_control_state *ecs = &ecss;
2992 struct cleanup *old_chain;
2995 /* If we're stopped at a fork/vfork, follow the branch set by the
2996 "set follow-fork-mode" command; otherwise, we'll just proceed
2997 resuming the current thread. */
2998 if (!follow_fork ())
3000 /* The target for some reason decided not to resume. */
3002 if (target_can_async_p ())
3003 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3007 /* We'll update this if & when we switch to a new thread. */
3008 previous_inferior_ptid = inferior_ptid;
3010 regcache = get_current_regcache ();
3011 gdbarch = get_regcache_arch (regcache);
3012 aspace = get_regcache_aspace (regcache);
3013 pc = regcache_read_pc (regcache);
3014 tp = inferior_thread ();
3016 /* Fill in with reasonable starting values. */
3017 init_thread_stepping_state (tp);
3019 gdb_assert (!thread_is_in_step_over_chain (tp));
3021 if (addr == (CORE_ADDR) -1)
3024 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
3025 && execution_direction != EXEC_REVERSE)
3026 /* There is a breakpoint at the address we will resume at,
3027 step one instruction before inserting breakpoints so that
3028 we do not stop right away (and report a second hit at this
3031 Note, we don't do this in reverse, because we won't
3032 actually be executing the breakpoint insn anyway.
3033 We'll be (un-)executing the previous instruction. */
3034 tp->stepping_over_breakpoint = 1;
3035 else if (gdbarch_single_step_through_delay_p (gdbarch)
3036 && gdbarch_single_step_through_delay (gdbarch,
3037 get_current_frame ()))
3038 /* We stepped onto an instruction that needs to be stepped
3039 again before re-inserting the breakpoint, do so. */
3040 tp->stepping_over_breakpoint = 1;
3044 regcache_write_pc (regcache, addr);
3047 if (siggnal != GDB_SIGNAL_DEFAULT)
3048 tp->suspend.stop_signal = siggnal;
3050 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3052 /* If an exception is thrown from this point on, make sure to
3053 propagate GDB's knowledge of the executing state to the
3054 frontend/user running state. */
3055 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
3057 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3058 threads (e.g., we might need to set threads stepping over
3059 breakpoints first), from the user/frontend's point of view, all
3060 threads in RESUME_PTID are now running. Unless we're calling an
3061 inferior function, as in that case we pretend the inferior
3062 doesn't run at all. */
3063 if (!tp->control.in_infcall)
3064 set_running (resume_ptid, 1);
3067 fprintf_unfiltered (gdb_stdlog,
3068 "infrun: proceed (addr=%s, signal=%s)\n",
3069 paddress (gdbarch, addr),
3070 gdb_signal_to_symbol_string (siggnal));
3072 annotate_starting ();
3074 /* Make sure that output from GDB appears before output from the
3076 gdb_flush (gdb_stdout);
3078 /* In a multi-threaded task we may select another thread and
3079 then continue or step.
3081 But if a thread that we're resuming had stopped at a breakpoint,
3082 it will immediately cause another breakpoint stop without any
3083 execution (i.e. it will report a breakpoint hit incorrectly). So
3084 we must step over it first.
3086 Look for threads other than the current (TP) that reported a
3087 breakpoint hit and haven't been resumed yet since. */
3089 /* If scheduler locking applies, we can avoid iterating over all
3091 if (!non_stop && !schedlock_applies (tp))
3093 struct thread_info *current = tp;
3095 ALL_NON_EXITED_THREADS (tp)
3097 /* Ignore the current thread here. It's handled
3102 /* Ignore threads of processes we're not resuming. */
3103 if (!ptid_match (tp->ptid, resume_ptid))
3106 if (!thread_still_needs_step_over (tp))
3109 gdb_assert (!thread_is_in_step_over_chain (tp));
3112 fprintf_unfiltered (gdb_stdlog,
3113 "infrun: need to step-over [%s] first\n",
3114 target_pid_to_str (tp->ptid));
3116 thread_step_over_chain_enqueue (tp);
3122 /* Enqueue the current thread last, so that we move all other
3123 threads over their breakpoints first. */
3124 if (tp->stepping_over_breakpoint)
3125 thread_step_over_chain_enqueue (tp);
3127 /* If the thread isn't started, we'll still need to set its prev_pc,
3128 so that switch_back_to_stepped_thread knows the thread hasn't
3129 advanced. Must do this before resuming any thread, as in
3130 all-stop/remote, once we resume we can't send any other packet
3131 until the target stops again. */
3132 tp->prev_pc = regcache_read_pc (regcache);
3135 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
3137 started = start_step_over ();
3139 if (step_over_info_valid_p ())
3141 /* Either this thread started a new in-line step over, or some
3142 other thread was already doing one. In either case, don't
3143 resume anything else until the step-over is finished. */
3145 else if (started && !target_is_non_stop_p ())
3147 /* A new displaced stepping sequence was started. In all-stop,
3148 we can't talk to the target anymore until it next stops. */
3150 else if (!non_stop && target_is_non_stop_p ())
3152 /* In all-stop, but the target is always in non-stop mode.
3153 Start all other threads that are implicitly resumed too. */
3154 ALL_NON_EXITED_THREADS (tp)
3156 /* Ignore threads of processes we're not resuming. */
3157 if (!ptid_match (tp->ptid, resume_ptid))
3163 fprintf_unfiltered (gdb_stdlog,
3164 "infrun: proceed: [%s] resumed\n",
3165 target_pid_to_str (tp->ptid));
3166 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3170 if (thread_is_in_step_over_chain (tp))
3173 fprintf_unfiltered (gdb_stdlog,
3174 "infrun: proceed: [%s] needs step-over\n",
3175 target_pid_to_str (tp->ptid));
3180 fprintf_unfiltered (gdb_stdlog,
3181 "infrun: proceed: resuming %s\n",
3182 target_pid_to_str (tp->ptid));
3184 reset_ecs (ecs, tp);
3185 switch_to_thread (tp->ptid);
3186 keep_going_pass_signal (ecs);
3187 if (!ecs->wait_some_more)
3188 error (_("Command aborted."));
3191 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3193 /* The thread wasn't started, and isn't queued, run it now. */
3194 reset_ecs (ecs, tp);
3195 switch_to_thread (tp->ptid);
3196 keep_going_pass_signal (ecs);
3197 if (!ecs->wait_some_more)
3198 error (_("Command aborted."));
3202 target_commit_resume ();
3204 discard_cleanups (old_chain);
3206 /* Tell the event loop to wait for it to stop. If the target
3207 supports asynchronous execution, it'll do this from within
3209 if (!target_can_async_p ())
3210 mark_async_event_handler (infrun_async_inferior_event_token);
3214 /* Start remote-debugging of a machine over a serial link. */
3217 start_remote (int from_tty)
3219 struct inferior *inferior;
3221 inferior = current_inferior ();
3222 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3224 /* Always go on waiting for the target, regardless of the mode. */
3225 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3226 indicate to wait_for_inferior that a target should timeout if
3227 nothing is returned (instead of just blocking). Because of this,
3228 targets expecting an immediate response need to, internally, set
3229 things up so that the target_wait() is forced to eventually
3231 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3232 differentiate to its caller what the state of the target is after
3233 the initial open has been performed. Here we're assuming that
3234 the target has stopped. It should be possible to eventually have
3235 target_open() return to the caller an indication that the target
3236 is currently running and GDB state should be set to the same as
3237 for an async run. */
3238 wait_for_inferior ();
3240 /* Now that the inferior has stopped, do any bookkeeping like
3241 loading shared libraries. We want to do this before normal_stop,
3242 so that the displayed frame is up to date. */
3243 post_create_inferior (¤t_target, from_tty);
3248 /* Initialize static vars when a new inferior begins. */
3251 init_wait_for_inferior (void)
3253 /* These are meaningless until the first time through wait_for_inferior. */
3255 breakpoint_init_inferior (inf_starting);
3257 clear_proceed_status (0);
3259 target_last_wait_ptid = minus_one_ptid;
3261 previous_inferior_ptid = inferior_ptid;
3263 /* Discard any skipped inlined frames. */
3264 clear_inline_frame_state (minus_one_ptid);
3269 static void handle_inferior_event (struct execution_control_state *ecs);
3271 static void handle_step_into_function (struct gdbarch *gdbarch,
3272 struct execution_control_state *ecs);
3273 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3274 struct execution_control_state *ecs);
3275 static void handle_signal_stop (struct execution_control_state *ecs);
3276 static void check_exception_resume (struct execution_control_state *,
3277 struct frame_info *);
3279 static void end_stepping_range (struct execution_control_state *ecs);
3280 static void stop_waiting (struct execution_control_state *ecs);
3281 static void keep_going (struct execution_control_state *ecs);
3282 static void process_event_stop_test (struct execution_control_state *ecs);
3283 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3285 /* This function is attached as a "thread_stop_requested" observer.
3286 Cleanup local state that assumed the PTID was to be resumed, and
3287 report the stop to the frontend. */
3290 infrun_thread_stop_requested (ptid_t ptid)
3292 struct thread_info *tp;
3294 /* PTID was requested to stop. If the thread was already stopped,
3295 but the user/frontend doesn't know about that yet (e.g., the
3296 thread had been temporarily paused for some step-over), set up
3297 for reporting the stop now. */
3298 ALL_NON_EXITED_THREADS (tp)
3299 if (ptid_match (tp->ptid, ptid))
3301 if (tp->state != THREAD_RUNNING)
3306 /* Remove matching threads from the step-over queue, so
3307 start_step_over doesn't try to resume them
3309 if (thread_is_in_step_over_chain (tp))
3310 thread_step_over_chain_remove (tp);
3312 /* If the thread is stopped, but the user/frontend doesn't
3313 know about that yet, queue a pending event, as if the
3314 thread had just stopped now. Unless the thread already had
3316 if (!tp->suspend.waitstatus_pending_p)
3318 tp->suspend.waitstatus_pending_p = 1;
3319 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3320 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3323 /* Clear the inline-frame state, since we're re-processing the
3325 clear_inline_frame_state (tp->ptid);
3327 /* If this thread was paused because some other thread was
3328 doing an inline-step over, let that finish first. Once
3329 that happens, we'll restart all threads and consume pending
3330 stop events then. */
3331 if (step_over_info_valid_p ())
3334 /* Otherwise we can process the (new) pending event now. Set
3335 it so this pending event is considered by
3342 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3344 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3345 nullify_last_target_wait_ptid ();
3348 /* Delete the step resume, single-step and longjmp/exception resume
3349 breakpoints of TP. */
3352 delete_thread_infrun_breakpoints (struct thread_info *tp)
3354 delete_step_resume_breakpoint (tp);
3355 delete_exception_resume_breakpoint (tp);
3356 delete_single_step_breakpoints (tp);
3359 /* If the target still has execution, call FUNC for each thread that
3360 just stopped. In all-stop, that's all the non-exited threads; in
3361 non-stop, that's the current thread, only. */
3363 typedef void (*for_each_just_stopped_thread_callback_func)
3364 (struct thread_info *tp);
3367 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3369 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3372 if (target_is_non_stop_p ())
3374 /* If in non-stop mode, only the current thread stopped. */
3375 func (inferior_thread ());
3379 struct thread_info *tp;
3381 /* In all-stop mode, all threads have stopped. */
3382 ALL_NON_EXITED_THREADS (tp)
3389 /* Delete the step resume and longjmp/exception resume breakpoints of
3390 the threads that just stopped. */
3393 delete_just_stopped_threads_infrun_breakpoints (void)
3395 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3398 /* Delete the single-step breakpoints of the threads that just
3402 delete_just_stopped_threads_single_step_breakpoints (void)
3404 for_each_just_stopped_thread (delete_single_step_breakpoints);
3407 /* A cleanup wrapper. */
3410 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3412 delete_just_stopped_threads_infrun_breakpoints ();
3418 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3419 const struct target_waitstatus *ws)
3421 std::string status_string = target_waitstatus_to_string (ws);
3424 /* The text is split over several lines because it was getting too long.
3425 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3426 output as a unit; we want only one timestamp printed if debug_timestamp
3429 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3430 ptid_get_pid (waiton_ptid),
3431 ptid_get_lwp (waiton_ptid),
3432 ptid_get_tid (waiton_ptid));
3433 if (ptid_get_pid (waiton_ptid) != -1)
3434 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3435 stb.printf (", status) =\n");
3436 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3437 ptid_get_pid (result_ptid),
3438 ptid_get_lwp (result_ptid),
3439 ptid_get_tid (result_ptid),
3440 target_pid_to_str (result_ptid));
3441 stb.printf ("infrun: %s\n", status_string.c_str ());
3443 /* This uses %s in part to handle %'s in the text, but also to avoid
3444 a gcc error: the format attribute requires a string literal. */
3445 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3448 /* Select a thread at random, out of those which are resumed and have
3451 static struct thread_info *
3452 random_pending_event_thread (ptid_t waiton_ptid)
3454 struct thread_info *event_tp;
3456 int random_selector;
3458 /* First see how many events we have. Count only resumed threads
3459 that have an event pending. */
3460 ALL_NON_EXITED_THREADS (event_tp)
3461 if (ptid_match (event_tp->ptid, waiton_ptid)
3462 && event_tp->resumed
3463 && event_tp->suspend.waitstatus_pending_p)
3466 if (num_events == 0)
3469 /* Now randomly pick a thread out of those that have had events. */
3470 random_selector = (int)
3471 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3473 if (debug_infrun && num_events > 1)
3474 fprintf_unfiltered (gdb_stdlog,
3475 "infrun: Found %d events, selecting #%d\n",
3476 num_events, random_selector);
3478 /* Select the Nth thread that has had an event. */
3479 ALL_NON_EXITED_THREADS (event_tp)
3480 if (ptid_match (event_tp->ptid, waiton_ptid)
3481 && event_tp->resumed
3482 && event_tp->suspend.waitstatus_pending_p)
3483 if (random_selector-- == 0)
3489 /* Wrapper for target_wait that first checks whether threads have
3490 pending statuses to report before actually asking the target for
3494 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3497 struct thread_info *tp;
3499 /* First check if there is a resumed thread with a wait status
3501 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3503 tp = random_pending_event_thread (ptid);
3508 fprintf_unfiltered (gdb_stdlog,
3509 "infrun: Waiting for specific thread %s.\n",
3510 target_pid_to_str (ptid));
3512 /* We have a specific thread to check. */
3513 tp = find_thread_ptid (ptid);
3514 gdb_assert (tp != NULL);
3515 if (!tp->suspend.waitstatus_pending_p)
3520 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3521 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3523 struct regcache *regcache = get_thread_regcache (tp->ptid);
3524 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3528 pc = regcache_read_pc (regcache);
3530 if (pc != tp->suspend.stop_pc)
3533 fprintf_unfiltered (gdb_stdlog,
3534 "infrun: PC of %s changed. was=%s, now=%s\n",
3535 target_pid_to_str (tp->ptid),
3536 paddress (gdbarch, tp->prev_pc),
3537 paddress (gdbarch, pc));
3540 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3543 fprintf_unfiltered (gdb_stdlog,
3544 "infrun: previous breakpoint of %s, at %s gone\n",
3545 target_pid_to_str (tp->ptid),
3546 paddress (gdbarch, pc));
3554 fprintf_unfiltered (gdb_stdlog,
3555 "infrun: pending event of %s cancelled.\n",
3556 target_pid_to_str (tp->ptid));
3558 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3559 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3568 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3570 fprintf_unfiltered (gdb_stdlog,
3571 "infrun: Using pending wait status %s for %s.\n",
3573 target_pid_to_str (tp->ptid));
3576 /* Now that we've selected our final event LWP, un-adjust its PC
3577 if it was a software breakpoint (and the target doesn't
3578 always adjust the PC itself). */
3579 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3580 && !target_supports_stopped_by_sw_breakpoint ())
3582 struct regcache *regcache;
3583 struct gdbarch *gdbarch;
3586 regcache = get_thread_regcache (tp->ptid);
3587 gdbarch = get_regcache_arch (regcache);
3589 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3594 pc = regcache_read_pc (regcache);
3595 regcache_write_pc (regcache, pc + decr_pc);
3599 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3600 *status = tp->suspend.waitstatus;
3601 tp->suspend.waitstatus_pending_p = 0;
3603 /* Wake up the event loop again, until all pending events are
3605 if (target_is_async_p ())
3606 mark_async_event_handler (infrun_async_inferior_event_token);
3610 /* But if we don't find one, we'll have to wait. */
3612 if (deprecated_target_wait_hook)
3613 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3615 event_ptid = target_wait (ptid, status, options);
3620 /* Prepare and stabilize the inferior for detaching it. E.g.,
3621 detaching while a thread is displaced stepping is a recipe for
3622 crashing it, as nothing would readjust the PC out of the scratch
3626 prepare_for_detach (void)
3628 struct inferior *inf = current_inferior ();
3629 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3630 struct displaced_step_inferior_state *displaced;
3632 displaced = get_displaced_stepping_state (inf->pid);
3634 /* Is any thread of this process displaced stepping? If not,
3635 there's nothing else to do. */
3636 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3640 fprintf_unfiltered (gdb_stdlog,
3641 "displaced-stepping in-process while detaching");
3643 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3645 while (!ptid_equal (displaced->step_ptid, null_ptid))
3647 struct cleanup *old_chain_2;
3648 struct execution_control_state ecss;
3649 struct execution_control_state *ecs;
3652 memset (ecs, 0, sizeof (*ecs));
3654 overlay_cache_invalid = 1;
3655 /* Flush target cache before starting to handle each event.
3656 Target was running and cache could be stale. This is just a
3657 heuristic. Running threads may modify target memory, but we
3658 don't get any event. */
3659 target_dcache_invalidate ();
3661 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3664 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3666 /* If an error happens while handling the event, propagate GDB's
3667 knowledge of the executing state to the frontend/user running
3669 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3672 /* Now figure out what to do with the result of the result. */
3673 handle_inferior_event (ecs);
3675 /* No error, don't finish the state yet. */
3676 discard_cleanups (old_chain_2);
3678 /* Breakpoints and watchpoints are not installed on the target
3679 at this point, and signals are passed directly to the
3680 inferior, so this must mean the process is gone. */
3681 if (!ecs->wait_some_more)
3683 restore_detaching.release ();
3684 error (_("Program exited while detaching"));
3688 restore_detaching.release ();
3691 /* Wait for control to return from inferior to debugger.
3693 If inferior gets a signal, we may decide to start it up again
3694 instead of returning. That is why there is a loop in this function.
3695 When this function actually returns it means the inferior
3696 should be left stopped and GDB should read more commands. */
3699 wait_for_inferior (void)
3701 struct cleanup *old_cleanups;
3702 struct cleanup *thread_state_chain;
3706 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3709 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3712 /* If an error happens while handling the event, propagate GDB's
3713 knowledge of the executing state to the frontend/user running
3715 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3719 struct execution_control_state ecss;
3720 struct execution_control_state *ecs = &ecss;
3721 ptid_t waiton_ptid = minus_one_ptid;
3723 memset (ecs, 0, sizeof (*ecs));
3725 overlay_cache_invalid = 1;
3727 /* Flush target cache before starting to handle each event.
3728 Target was running and cache could be stale. This is just a
3729 heuristic. Running threads may modify target memory, but we
3730 don't get any event. */
3731 target_dcache_invalidate ();
3733 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3736 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3738 /* Now figure out what to do with the result of the result. */
3739 handle_inferior_event (ecs);
3741 if (!ecs->wait_some_more)
3745 /* No error, don't finish the state yet. */
3746 discard_cleanups (thread_state_chain);
3748 do_cleanups (old_cleanups);
3751 /* Cleanup that reinstalls the readline callback handler, if the
3752 target is running in the background. If while handling the target
3753 event something triggered a secondary prompt, like e.g., a
3754 pagination prompt, we'll have removed the callback handler (see
3755 gdb_readline_wrapper_line). Need to do this as we go back to the
3756 event loop, ready to process further input. Note this has no
3757 effect if the handler hasn't actually been removed, because calling
3758 rl_callback_handler_install resets the line buffer, thus losing
3762 reinstall_readline_callback_handler_cleanup (void *arg)
3764 struct ui *ui = current_ui;
3768 /* We're not going back to the top level event loop yet. Don't
3769 install the readline callback, as it'd prep the terminal,
3770 readline-style (raw, noecho) (e.g., --batch). We'll install
3771 it the next time the prompt is displayed, when we're ready
3776 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3777 gdb_rl_callback_handler_reinstall ();
3780 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3781 that's just the event thread. In all-stop, that's all threads. */
3784 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3786 struct thread_info *thr = ecs->event_thread;
3788 if (thr != NULL && thr->thread_fsm != NULL)
3789 thread_fsm_clean_up (thr->thread_fsm, thr);
3793 ALL_NON_EXITED_THREADS (thr)
3795 if (thr->thread_fsm == NULL)
3797 if (thr == ecs->event_thread)
3800 switch_to_thread (thr->ptid);
3801 thread_fsm_clean_up (thr->thread_fsm, thr);
3804 if (ecs->event_thread != NULL)
3805 switch_to_thread (ecs->event_thread->ptid);
3809 /* Helper for all_uis_check_sync_execution_done that works on the
3813 check_curr_ui_sync_execution_done (void)
3815 struct ui *ui = current_ui;
3817 if (ui->prompt_state == PROMPT_NEEDED
3819 && !gdb_in_secondary_prompt_p (ui))
3821 target_terminal::ours ();
3822 observer_notify_sync_execution_done ();
3823 ui_register_input_event_handler (ui);
3830 all_uis_check_sync_execution_done (void)
3832 SWITCH_THRU_ALL_UIS ()
3834 check_curr_ui_sync_execution_done ();
3841 all_uis_on_sync_execution_starting (void)
3843 SWITCH_THRU_ALL_UIS ()
3845 if (current_ui->prompt_state == PROMPT_NEEDED)
3846 async_disable_stdin ();
3850 /* Asynchronous version of wait_for_inferior. It is called by the
3851 event loop whenever a change of state is detected on the file
3852 descriptor corresponding to the target. It can be called more than
3853 once to complete a single execution command. In such cases we need
3854 to keep the state in a global variable ECSS. If it is the last time
3855 that this function is called for a single execution command, then
3856 report to the user that the inferior has stopped, and do the
3857 necessary cleanups. */
3860 fetch_inferior_event (void *client_data)
3862 struct execution_control_state ecss;
3863 struct execution_control_state *ecs = &ecss;
3864 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3865 struct cleanup *ts_old_chain;
3867 ptid_t waiton_ptid = minus_one_ptid;
3869 memset (ecs, 0, sizeof (*ecs));
3871 /* Events are always processed with the main UI as current UI. This
3872 way, warnings, debug output, etc. are always consistently sent to
3873 the main console. */
3874 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3876 /* End up with readline processing input, if necessary. */
3877 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3879 /* We're handling a live event, so make sure we're doing live
3880 debugging. If we're looking at traceframes while the target is
3881 running, we're going to need to get back to that mode after
3882 handling the event. */
3885 make_cleanup_restore_current_traceframe ();
3886 set_current_traceframe (-1);
3889 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3892 /* In non-stop mode, the user/frontend should not notice a thread
3893 switch due to internal events. Make sure we reverse to the
3894 user selected thread and frame after handling the event and
3895 running any breakpoint commands. */
3896 maybe_restore_thread.emplace ();
3898 overlay_cache_invalid = 1;
3899 /* Flush target cache before starting to handle each event. Target
3900 was running and cache could be stale. This is just a heuristic.
3901 Running threads may modify target memory, but we don't get any
3903 target_dcache_invalidate ();
3905 scoped_restore save_exec_dir
3906 = make_scoped_restore (&execution_direction, target_execution_direction ());
3908 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3909 target_can_async_p () ? TARGET_WNOHANG : 0);
3912 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3914 /* If an error happens while handling the event, propagate GDB's
3915 knowledge of the executing state to the frontend/user running
3917 if (!target_is_non_stop_p ())
3918 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3920 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3922 /* Get executed before make_cleanup_restore_current_thread above to apply
3923 still for the thread which has thrown the exception. */
3924 make_bpstat_clear_actions_cleanup ();
3926 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3928 /* Now figure out what to do with the result of the result. */
3929 handle_inferior_event (ecs);
3931 if (!ecs->wait_some_more)
3933 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3934 int should_stop = 1;
3935 struct thread_info *thr = ecs->event_thread;
3936 int should_notify_stop = 1;
3938 delete_just_stopped_threads_infrun_breakpoints ();
3942 struct thread_fsm *thread_fsm = thr->thread_fsm;
3944 if (thread_fsm != NULL)
3945 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3954 clean_up_just_stopped_threads_fsms (ecs);
3956 if (thr != NULL && thr->thread_fsm != NULL)
3959 = thread_fsm_should_notify_stop (thr->thread_fsm);
3962 if (should_notify_stop)
3966 /* We may not find an inferior if this was a process exit. */
3967 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3968 proceeded = normal_stop ();
3972 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3979 /* No error, don't finish the thread states yet. */
3980 discard_cleanups (ts_old_chain);
3982 /* Revert thread and frame. */
3983 do_cleanups (old_chain);
3985 /* If a UI was in sync execution mode, and now isn't, restore its
3986 prompt (a synchronous execution command has finished, and we're
3987 ready for input). */
3988 all_uis_check_sync_execution_done ();
3991 && exec_done_display_p
3992 && (ptid_equal (inferior_ptid, null_ptid)
3993 || !is_running (inferior_ptid)))
3994 printf_unfiltered (_("completed.\n"));
3997 /* Record the frame and location we're currently stepping through. */
3999 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
4001 struct thread_info *tp = inferior_thread ();
4003 tp->control.step_frame_id = get_frame_id (frame);
4004 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
4006 tp->current_symtab = sal.symtab;
4007 tp->current_line = sal.line;
4010 /* Clear context switchable stepping state. */
4013 init_thread_stepping_state (struct thread_info *tss)
4015 tss->stepped_breakpoint = 0;
4016 tss->stepping_over_breakpoint = 0;
4017 tss->stepping_over_watchpoint = 0;
4018 tss->step_after_step_resume_breakpoint = 0;
4021 /* Set the cached copy of the last ptid/waitstatus. */
4024 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4026 target_last_wait_ptid = ptid;
4027 target_last_waitstatus = status;
4030 /* Return the cached copy of the last pid/waitstatus returned by
4031 target_wait()/deprecated_target_wait_hook(). The data is actually
4032 cached by handle_inferior_event(), which gets called immediately
4033 after target_wait()/deprecated_target_wait_hook(). */
4036 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4038 *ptidp = target_last_wait_ptid;
4039 *status = target_last_waitstatus;
4043 nullify_last_target_wait_ptid (void)
4045 target_last_wait_ptid = minus_one_ptid;
4048 /* Switch thread contexts. */
4051 context_switch (ptid_t ptid)
4053 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4055 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4056 target_pid_to_str (inferior_ptid));
4057 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4058 target_pid_to_str (ptid));
4061 switch_to_thread (ptid);
4064 /* If the target can't tell whether we've hit breakpoints
4065 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4066 check whether that could have been caused by a breakpoint. If so,
4067 adjust the PC, per gdbarch_decr_pc_after_break. */
4070 adjust_pc_after_break (struct thread_info *thread,
4071 struct target_waitstatus *ws)
4073 struct regcache *regcache;
4074 struct gdbarch *gdbarch;
4075 struct address_space *aspace;
4076 CORE_ADDR breakpoint_pc, decr_pc;
4078 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4079 we aren't, just return.
4081 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4082 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4083 implemented by software breakpoints should be handled through the normal
4086 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4087 different signals (SIGILL or SIGEMT for instance), but it is less
4088 clear where the PC is pointing afterwards. It may not match
4089 gdbarch_decr_pc_after_break. I don't know any specific target that
4090 generates these signals at breakpoints (the code has been in GDB since at
4091 least 1992) so I can not guess how to handle them here.
4093 In earlier versions of GDB, a target with
4094 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4095 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4096 target with both of these set in GDB history, and it seems unlikely to be
4097 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4099 if (ws->kind != TARGET_WAITKIND_STOPPED)
4102 if (ws->value.sig != GDB_SIGNAL_TRAP)
4105 /* In reverse execution, when a breakpoint is hit, the instruction
4106 under it has already been de-executed. The reported PC always
4107 points at the breakpoint address, so adjusting it further would
4108 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4111 B1 0x08000000 : INSN1
4112 B2 0x08000001 : INSN2
4114 PC -> 0x08000003 : INSN4
4116 Say you're stopped at 0x08000003 as above. Reverse continuing
4117 from that point should hit B2 as below. Reading the PC when the
4118 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4119 been de-executed already.
4121 B1 0x08000000 : INSN1
4122 B2 PC -> 0x08000001 : INSN2
4126 We can't apply the same logic as for forward execution, because
4127 we would wrongly adjust the PC to 0x08000000, since there's a
4128 breakpoint at PC - 1. We'd then report a hit on B1, although
4129 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4131 if (execution_direction == EXEC_REVERSE)
4134 /* If the target can tell whether the thread hit a SW breakpoint,
4135 trust it. Targets that can tell also adjust the PC
4137 if (target_supports_stopped_by_sw_breakpoint ())
4140 /* Note that relying on whether a breakpoint is planted in memory to
4141 determine this can fail. E.g,. the breakpoint could have been
4142 removed since. Or the thread could have been told to step an
4143 instruction the size of a breakpoint instruction, and only
4144 _after_ was a breakpoint inserted at its address. */
4146 /* If this target does not decrement the PC after breakpoints, then
4147 we have nothing to do. */
4148 regcache = get_thread_regcache (thread->ptid);
4149 gdbarch = get_regcache_arch (regcache);
4151 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4155 aspace = get_regcache_aspace (regcache);
4157 /* Find the location where (if we've hit a breakpoint) the
4158 breakpoint would be. */
4159 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4161 /* If the target can't tell whether a software breakpoint triggered,
4162 fallback to figuring it out based on breakpoints we think were
4163 inserted in the target, and on whether the thread was stepped or
4166 /* Check whether there actually is a software breakpoint inserted at
4169 If in non-stop mode, a race condition is possible where we've
4170 removed a breakpoint, but stop events for that breakpoint were
4171 already queued and arrive later. To suppress those spurious
4172 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4173 and retire them after a number of stop events are reported. Note
4174 this is an heuristic and can thus get confused. The real fix is
4175 to get the "stopped by SW BP and needs adjustment" info out of
4176 the target/kernel (and thus never reach here; see above). */
4177 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4178 || (target_is_non_stop_p ()
4179 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4181 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4183 if (record_full_is_used ())
4184 restore_operation_disable.emplace
4185 (record_full_gdb_operation_disable_set ());
4187 /* When using hardware single-step, a SIGTRAP is reported for both
4188 a completed single-step and a software breakpoint. Need to
4189 differentiate between the two, as the latter needs adjusting
4190 but the former does not.
4192 The SIGTRAP can be due to a completed hardware single-step only if
4193 - we didn't insert software single-step breakpoints
4194 - this thread is currently being stepped
4196 If any of these events did not occur, we must have stopped due
4197 to hitting a software breakpoint, and have to back up to the
4200 As a special case, we could have hardware single-stepped a
4201 software breakpoint. In this case (prev_pc == breakpoint_pc),
4202 we also need to back up to the breakpoint address. */
4204 if (thread_has_single_step_breakpoints_set (thread)
4205 || !currently_stepping (thread)
4206 || (thread->stepped_breakpoint
4207 && thread->prev_pc == breakpoint_pc))
4208 regcache_write_pc (regcache, breakpoint_pc);
4213 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4215 for (frame = get_prev_frame (frame);
4217 frame = get_prev_frame (frame))
4219 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4221 if (get_frame_type (frame) != INLINE_FRAME)
4228 /* If the event thread has the stop requested flag set, pretend it
4229 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4233 handle_stop_requested (struct execution_control_state *ecs)
4235 if (ecs->event_thread->stop_requested)
4237 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4238 ecs->ws.value.sig = GDB_SIGNAL_0;
4239 handle_signal_stop (ecs);
4245 /* Auxiliary function that handles syscall entry/return events.
4246 It returns 1 if the inferior should keep going (and GDB
4247 should ignore the event), or 0 if the event deserves to be
4251 handle_syscall_event (struct execution_control_state *ecs)
4253 struct regcache *regcache;
4256 if (!ptid_equal (ecs->ptid, inferior_ptid))
4257 context_switch (ecs->ptid);
4259 regcache = get_thread_regcache (ecs->ptid);
4260 syscall_number = ecs->ws.value.syscall_number;
4261 stop_pc = regcache_read_pc (regcache);
4263 if (catch_syscall_enabled () > 0
4264 && catching_syscall_number (syscall_number) > 0)
4267 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4270 ecs->event_thread->control.stop_bpstat
4271 = bpstat_stop_status (get_regcache_aspace (regcache),
4272 stop_pc, ecs->ptid, &ecs->ws);
4274 if (handle_stop_requested (ecs))
4277 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4279 /* Catchpoint hit. */
4284 if (handle_stop_requested (ecs))
4287 /* If no catchpoint triggered for this, then keep going. */
4292 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4295 fill_in_stop_func (struct gdbarch *gdbarch,
4296 struct execution_control_state *ecs)
4298 if (!ecs->stop_func_filled_in)
4300 /* Don't care about return value; stop_func_start and stop_func_name
4301 will both be 0 if it doesn't work. */
4302 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4303 &ecs->stop_func_start, &ecs->stop_func_end);
4304 ecs->stop_func_start
4305 += gdbarch_deprecated_function_start_offset (gdbarch);
4307 if (gdbarch_skip_entrypoint_p (gdbarch))
4308 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4309 ecs->stop_func_start);
4311 ecs->stop_func_filled_in = 1;
4316 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4318 static enum stop_kind
4319 get_inferior_stop_soon (ptid_t ptid)
4321 struct inferior *inf = find_inferior_ptid (ptid);
4323 gdb_assert (inf != NULL);
4324 return inf->control.stop_soon;
4327 /* Wait for one event. Store the resulting waitstatus in WS, and
4328 return the event ptid. */
4331 wait_one (struct target_waitstatus *ws)
4334 ptid_t wait_ptid = minus_one_ptid;
4336 overlay_cache_invalid = 1;
4338 /* Flush target cache before starting to handle each event.
4339 Target was running and cache could be stale. This is just a
4340 heuristic. Running threads may modify target memory, but we
4341 don't get any event. */
4342 target_dcache_invalidate ();
4344 if (deprecated_target_wait_hook)
4345 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4347 event_ptid = target_wait (wait_ptid, ws, 0);
4350 print_target_wait_results (wait_ptid, event_ptid, ws);
4355 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4356 instead of the current thread. */
4357 #define THREAD_STOPPED_BY(REASON) \
4359 thread_stopped_by_ ## REASON (ptid_t ptid) \
4361 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4362 inferior_ptid = ptid; \
4364 return target_stopped_by_ ## REASON (); \
4367 /* Generate thread_stopped_by_watchpoint. */
4368 THREAD_STOPPED_BY (watchpoint)
4369 /* Generate thread_stopped_by_sw_breakpoint. */
4370 THREAD_STOPPED_BY (sw_breakpoint)
4371 /* Generate thread_stopped_by_hw_breakpoint. */
4372 THREAD_STOPPED_BY (hw_breakpoint)
4374 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4377 switch_to_thread_cleanup (void *ptid_p)
4379 ptid_t ptid = *(ptid_t *) ptid_p;
4381 switch_to_thread (ptid);
4384 /* Save the thread's event and stop reason to process it later. */
4387 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4389 struct regcache *regcache;
4390 struct address_space *aspace;
4394 std::string statstr = target_waitstatus_to_string (ws);
4396 fprintf_unfiltered (gdb_stdlog,
4397 "infrun: saving status %s for %d.%ld.%ld\n",
4399 ptid_get_pid (tp->ptid),
4400 ptid_get_lwp (tp->ptid),
4401 ptid_get_tid (tp->ptid));
4404 /* Record for later. */
4405 tp->suspend.waitstatus = *ws;
4406 tp->suspend.waitstatus_pending_p = 1;
4408 regcache = get_thread_regcache (tp->ptid);
4409 aspace = get_regcache_aspace (regcache);
4411 if (ws->kind == TARGET_WAITKIND_STOPPED
4412 && ws->value.sig == GDB_SIGNAL_TRAP)
4414 CORE_ADDR pc = regcache_read_pc (regcache);
4416 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4418 if (thread_stopped_by_watchpoint (tp->ptid))
4420 tp->suspend.stop_reason
4421 = TARGET_STOPPED_BY_WATCHPOINT;
4423 else if (target_supports_stopped_by_sw_breakpoint ()
4424 && thread_stopped_by_sw_breakpoint (tp->ptid))
4426 tp->suspend.stop_reason
4427 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4429 else if (target_supports_stopped_by_hw_breakpoint ()
4430 && thread_stopped_by_hw_breakpoint (tp->ptid))
4432 tp->suspend.stop_reason
4433 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4435 else if (!target_supports_stopped_by_hw_breakpoint ()
4436 && hardware_breakpoint_inserted_here_p (aspace,
4439 tp->suspend.stop_reason
4440 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4442 else if (!target_supports_stopped_by_sw_breakpoint ()
4443 && software_breakpoint_inserted_here_p (aspace,
4446 tp->suspend.stop_reason
4447 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4449 else if (!thread_has_single_step_breakpoints_set (tp)
4450 && currently_stepping (tp))
4452 tp->suspend.stop_reason
4453 = TARGET_STOPPED_BY_SINGLE_STEP;
4458 /* A cleanup that disables thread create/exit events. */
4461 disable_thread_events (void *arg)
4463 target_thread_events (0);
4469 stop_all_threads (void)
4471 /* We may need multiple passes to discover all threads. */
4475 struct cleanup *old_chain;
4477 gdb_assert (target_is_non_stop_p ());
4480 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4482 entry_ptid = inferior_ptid;
4483 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4485 target_thread_events (1);
4486 make_cleanup (disable_thread_events, NULL);
4488 /* Request threads to stop, and then wait for the stops. Because
4489 threads we already know about can spawn more threads while we're
4490 trying to stop them, and we only learn about new threads when we
4491 update the thread list, do this in a loop, and keep iterating
4492 until two passes find no threads that need to be stopped. */
4493 for (pass = 0; pass < 2; pass++, iterations++)
4496 fprintf_unfiltered (gdb_stdlog,
4497 "infrun: stop_all_threads, pass=%d, "
4498 "iterations=%d\n", pass, iterations);
4502 struct target_waitstatus ws;
4504 struct thread_info *t;
4506 update_thread_list ();
4508 /* Go through all threads looking for threads that we need
4509 to tell the target to stop. */
4510 ALL_NON_EXITED_THREADS (t)
4514 /* If already stopping, don't request a stop again.
4515 We just haven't seen the notification yet. */
4516 if (!t->stop_requested)
4519 fprintf_unfiltered (gdb_stdlog,
4520 "infrun: %s executing, "
4522 target_pid_to_str (t->ptid));
4523 target_stop (t->ptid);
4524 t->stop_requested = 1;
4529 fprintf_unfiltered (gdb_stdlog,
4530 "infrun: %s executing, "
4531 "already stopping\n",
4532 target_pid_to_str (t->ptid));
4535 if (t->stop_requested)
4541 fprintf_unfiltered (gdb_stdlog,
4542 "infrun: %s not executing\n",
4543 target_pid_to_str (t->ptid));
4545 /* The thread may be not executing, but still be
4546 resumed with a pending status to process. */
4554 /* If we find new threads on the second iteration, restart
4555 over. We want to see two iterations in a row with all
4560 event_ptid = wait_one (&ws);
4561 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4563 /* All resumed threads exited. */
4565 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4566 || ws.kind == TARGET_WAITKIND_EXITED
4567 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4571 ptid_t ptid = pid_to_ptid (ws.value.integer);
4573 fprintf_unfiltered (gdb_stdlog,
4574 "infrun: %s exited while "
4575 "stopping threads\n",
4576 target_pid_to_str (ptid));
4581 struct inferior *inf;
4583 t = find_thread_ptid (event_ptid);
4585 t = add_thread (event_ptid);
4587 t->stop_requested = 0;
4590 t->control.may_range_step = 0;
4592 /* This may be the first time we see the inferior report
4594 inf = find_inferior_ptid (event_ptid);
4595 if (inf->needs_setup)
4597 switch_to_thread_no_regs (t);
4601 if (ws.kind == TARGET_WAITKIND_STOPPED
4602 && ws.value.sig == GDB_SIGNAL_0)
4604 /* We caught the event that we intended to catch, so
4605 there's no event pending. */
4606 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4607 t->suspend.waitstatus_pending_p = 0;
4609 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4611 /* Add it back to the step-over queue. */
4614 fprintf_unfiltered (gdb_stdlog,
4615 "infrun: displaced-step of %s "
4616 "canceled: adding back to the "
4617 "step-over queue\n",
4618 target_pid_to_str (t->ptid));
4620 t->control.trap_expected = 0;
4621 thread_step_over_chain_enqueue (t);
4626 enum gdb_signal sig;
4627 struct regcache *regcache;
4631 std::string statstr = target_waitstatus_to_string (&ws);
4633 fprintf_unfiltered (gdb_stdlog,
4634 "infrun: target_wait %s, saving "
4635 "status for %d.%ld.%ld\n",
4637 ptid_get_pid (t->ptid),
4638 ptid_get_lwp (t->ptid),
4639 ptid_get_tid (t->ptid));
4642 /* Record for later. */
4643 save_waitstatus (t, &ws);
4645 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4646 ? ws.value.sig : GDB_SIGNAL_0);
4648 if (displaced_step_fixup (t->ptid, sig) < 0)
4650 /* Add it back to the step-over queue. */
4651 t->control.trap_expected = 0;
4652 thread_step_over_chain_enqueue (t);
4655 regcache = get_thread_regcache (t->ptid);
4656 t->suspend.stop_pc = regcache_read_pc (regcache);
4660 fprintf_unfiltered (gdb_stdlog,
4661 "infrun: saved stop_pc=%s for %s "
4662 "(currently_stepping=%d)\n",
4663 paddress (target_gdbarch (),
4664 t->suspend.stop_pc),
4665 target_pid_to_str (t->ptid),
4666 currently_stepping (t));
4673 do_cleanups (old_chain);
4676 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4679 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4682 handle_no_resumed (struct execution_control_state *ecs)
4684 struct inferior *inf;
4685 struct thread_info *thread;
4687 if (target_can_async_p ())
4694 if (ui->prompt_state == PROMPT_BLOCKED)
4702 /* There were no unwaited-for children left in the target, but,
4703 we're not synchronously waiting for events either. Just
4707 fprintf_unfiltered (gdb_stdlog,
4708 "infrun: TARGET_WAITKIND_NO_RESUMED "
4709 "(ignoring: bg)\n");
4710 prepare_to_wait (ecs);
4715 /* Otherwise, if we were running a synchronous execution command, we
4716 may need to cancel it and give the user back the terminal.
4718 In non-stop mode, the target can't tell whether we've already
4719 consumed previous stop events, so it can end up sending us a
4720 no-resumed event like so:
4722 #0 - thread 1 is left stopped
4724 #1 - thread 2 is resumed and hits breakpoint
4725 -> TARGET_WAITKIND_STOPPED
4727 #2 - thread 3 is resumed and exits
4728 this is the last resumed thread, so
4729 -> TARGET_WAITKIND_NO_RESUMED
4731 #3 - gdb processes stop for thread 2 and decides to re-resume
4734 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4735 thread 2 is now resumed, so the event should be ignored.
4737 IOW, if the stop for thread 2 doesn't end a foreground command,
4738 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4739 event. But it could be that the event meant that thread 2 itself
4740 (or whatever other thread was the last resumed thread) exited.
4742 To address this we refresh the thread list and check whether we
4743 have resumed threads _now_. In the example above, this removes
4744 thread 3 from the thread list. If thread 2 was re-resumed, we
4745 ignore this event. If we find no thread resumed, then we cancel
4746 the synchronous command show "no unwaited-for " to the user. */
4747 update_thread_list ();
4749 ALL_NON_EXITED_THREADS (thread)
4751 if (thread->executing
4752 || thread->suspend.waitstatus_pending_p)
4754 /* There were no unwaited-for children left in the target at
4755 some point, but there are now. Just ignore. */
4757 fprintf_unfiltered (gdb_stdlog,
4758 "infrun: TARGET_WAITKIND_NO_RESUMED "
4759 "(ignoring: found resumed)\n");
4760 prepare_to_wait (ecs);
4765 /* Note however that we may find no resumed thread because the whole
4766 process exited meanwhile (thus updating the thread list results
4767 in an empty thread list). In this case we know we'll be getting
4768 a process exit event shortly. */
4774 thread = any_live_thread_of_process (inf->pid);
4778 fprintf_unfiltered (gdb_stdlog,
4779 "infrun: TARGET_WAITKIND_NO_RESUMED "
4780 "(expect process exit)\n");
4781 prepare_to_wait (ecs);
4786 /* Go ahead and report the event. */
4790 /* Given an execution control state that has been freshly filled in by
4791 an event from the inferior, figure out what it means and take
4794 The alternatives are:
4796 1) stop_waiting and return; to really stop and return to the
4799 2) keep_going and return; to wait for the next event (set
4800 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4804 handle_inferior_event_1 (struct execution_control_state *ecs)
4806 enum stop_kind stop_soon;
4808 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4810 /* We had an event in the inferior, but we are not interested in
4811 handling it at this level. The lower layers have already
4812 done what needs to be done, if anything.
4814 One of the possible circumstances for this is when the
4815 inferior produces output for the console. The inferior has
4816 not stopped, and we are ignoring the event. Another possible
4817 circumstance is any event which the lower level knows will be
4818 reported multiple times without an intervening resume. */
4820 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4821 prepare_to_wait (ecs);
4825 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4828 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4829 prepare_to_wait (ecs);
4833 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4834 && handle_no_resumed (ecs))
4837 /* Cache the last pid/waitstatus. */
4838 set_last_target_status (ecs->ptid, ecs->ws);
4840 /* Always clear state belonging to the previous time we stopped. */
4841 stop_stack_dummy = STOP_NONE;
4843 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4845 /* No unwaited-for children left. IOW, all resumed children
4848 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4850 stop_print_frame = 0;
4855 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4856 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4858 ecs->event_thread = find_thread_ptid (ecs->ptid);
4859 /* If it's a new thread, add it to the thread database. */
4860 if (ecs->event_thread == NULL)
4861 ecs->event_thread = add_thread (ecs->ptid);
4863 /* Disable range stepping. If the next step request could use a
4864 range, this will be end up re-enabled then. */
4865 ecs->event_thread->control.may_range_step = 0;
4868 /* Dependent on valid ECS->EVENT_THREAD. */
4869 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4871 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4872 reinit_frame_cache ();
4874 breakpoint_retire_moribund ();
4876 /* First, distinguish signals caused by the debugger from signals
4877 that have to do with the program's own actions. Note that
4878 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4879 on the operating system version. Here we detect when a SIGILL or
4880 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4881 something similar for SIGSEGV, since a SIGSEGV will be generated
4882 when we're trying to execute a breakpoint instruction on a
4883 non-executable stack. This happens for call dummy breakpoints
4884 for architectures like SPARC that place call dummies on the
4886 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4887 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4888 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4889 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4891 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4893 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
4894 regcache_read_pc (regcache)))
4897 fprintf_unfiltered (gdb_stdlog,
4898 "infrun: Treating signal as SIGTRAP\n");
4899 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4903 /* Mark the non-executing threads accordingly. In all-stop, all
4904 threads of all processes are stopped when we get any event
4905 reported. In non-stop mode, only the event thread stops. */
4909 if (!target_is_non_stop_p ())
4910 mark_ptid = minus_one_ptid;
4911 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4912 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4914 /* If we're handling a process exit in non-stop mode, even
4915 though threads haven't been deleted yet, one would think
4916 that there is nothing to do, as threads of the dead process
4917 will be soon deleted, and threads of any other process were
4918 left running. However, on some targets, threads survive a
4919 process exit event. E.g., for the "checkpoint" command,
4920 when the current checkpoint/fork exits, linux-fork.c
4921 automatically switches to another fork from within
4922 target_mourn_inferior, by associating the same
4923 inferior/thread to another fork. We haven't mourned yet at
4924 this point, but we must mark any threads left in the
4925 process as not-executing so that finish_thread_state marks
4926 them stopped (in the user's perspective) if/when we present
4927 the stop to the user. */
4928 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4931 mark_ptid = ecs->ptid;
4933 set_executing (mark_ptid, 0);
4935 /* Likewise the resumed flag. */
4936 set_resumed (mark_ptid, 0);
4939 switch (ecs->ws.kind)
4941 case TARGET_WAITKIND_LOADED:
4943 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4944 if (!ptid_equal (ecs->ptid, inferior_ptid))
4945 context_switch (ecs->ptid);
4946 /* Ignore gracefully during startup of the inferior, as it might
4947 be the shell which has just loaded some objects, otherwise
4948 add the symbols for the newly loaded objects. Also ignore at
4949 the beginning of an attach or remote session; we will query
4950 the full list of libraries once the connection is
4953 stop_soon = get_inferior_stop_soon (ecs->ptid);
4954 if (stop_soon == NO_STOP_QUIETLY)
4956 struct regcache *regcache;
4958 regcache = get_thread_regcache (ecs->ptid);
4960 handle_solib_event ();
4962 ecs->event_thread->control.stop_bpstat
4963 = bpstat_stop_status (get_regcache_aspace (regcache),
4964 stop_pc, ecs->ptid, &ecs->ws);
4966 if (handle_stop_requested (ecs))
4969 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4971 /* A catchpoint triggered. */
4972 process_event_stop_test (ecs);
4976 /* If requested, stop when the dynamic linker notifies
4977 gdb of events. This allows the user to get control
4978 and place breakpoints in initializer routines for
4979 dynamically loaded objects (among other things). */
4980 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4981 if (stop_on_solib_events)
4983 /* Make sure we print "Stopped due to solib-event" in
4985 stop_print_frame = 1;
4992 /* If we are skipping through a shell, or through shared library
4993 loading that we aren't interested in, resume the program. If
4994 we're running the program normally, also resume. */
4995 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4997 /* Loading of shared libraries might have changed breakpoint
4998 addresses. Make sure new breakpoints are inserted. */
4999 if (stop_soon == NO_STOP_QUIETLY)
5000 insert_breakpoints ();
5001 resume (GDB_SIGNAL_0);
5002 prepare_to_wait (ecs);
5006 /* But stop if we're attaching or setting up a remote
5008 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5009 || stop_soon == STOP_QUIETLY_REMOTE)
5012 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5017 internal_error (__FILE__, __LINE__,
5018 _("unhandled stop_soon: %d"), (int) stop_soon);
5020 case TARGET_WAITKIND_SPURIOUS:
5022 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5023 if (handle_stop_requested (ecs))
5025 if (!ptid_equal (ecs->ptid, inferior_ptid))
5026 context_switch (ecs->ptid);
5027 resume (GDB_SIGNAL_0);
5028 prepare_to_wait (ecs);
5031 case TARGET_WAITKIND_THREAD_CREATED:
5033 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5034 if (handle_stop_requested (ecs))
5036 if (!ptid_equal (ecs->ptid, inferior_ptid))
5037 context_switch (ecs->ptid);
5038 if (!switch_back_to_stepped_thread (ecs))
5042 case TARGET_WAITKIND_EXITED:
5043 case TARGET_WAITKIND_SIGNALLED:
5046 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5047 fprintf_unfiltered (gdb_stdlog,
5048 "infrun: TARGET_WAITKIND_EXITED\n");
5050 fprintf_unfiltered (gdb_stdlog,
5051 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5054 inferior_ptid = ecs->ptid;
5055 set_current_inferior (find_inferior_ptid (ecs->ptid));
5056 set_current_program_space (current_inferior ()->pspace);
5057 handle_vfork_child_exec_or_exit (0);
5058 target_terminal::ours (); /* Must do this before mourn anyway. */
5060 /* Clearing any previous state of convenience variables. */
5061 clear_exit_convenience_vars ();
5063 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5065 /* Record the exit code in the convenience variable $_exitcode, so
5066 that the user can inspect this again later. */
5067 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5068 (LONGEST) ecs->ws.value.integer);
5070 /* Also record this in the inferior itself. */
5071 current_inferior ()->has_exit_code = 1;
5072 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5074 /* Support the --return-child-result option. */
5075 return_child_result_value = ecs->ws.value.integer;
5077 observer_notify_exited (ecs->ws.value.integer);
5081 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5082 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5084 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5086 /* Set the value of the internal variable $_exitsignal,
5087 which holds the signal uncaught by the inferior. */
5088 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5089 gdbarch_gdb_signal_to_target (gdbarch,
5090 ecs->ws.value.sig));
5094 /* We don't have access to the target's method used for
5095 converting between signal numbers (GDB's internal
5096 representation <-> target's representation).
5097 Therefore, we cannot do a good job at displaying this
5098 information to the user. It's better to just warn
5099 her about it (if infrun debugging is enabled), and
5102 fprintf_filtered (gdb_stdlog, _("\
5103 Cannot fill $_exitsignal with the correct signal number.\n"));
5106 observer_notify_signal_exited (ecs->ws.value.sig);
5109 gdb_flush (gdb_stdout);
5110 target_mourn_inferior (inferior_ptid);
5111 stop_print_frame = 0;
5115 /* The following are the only cases in which we keep going;
5116 the above cases end in a continue or goto. */
5117 case TARGET_WAITKIND_FORKED:
5118 case TARGET_WAITKIND_VFORKED:
5121 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5122 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5124 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5127 /* Check whether the inferior is displaced stepping. */
5129 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5130 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5132 /* If checking displaced stepping is supported, and thread
5133 ecs->ptid is displaced stepping. */
5134 if (displaced_step_in_progress_thread (ecs->ptid))
5136 struct inferior *parent_inf
5137 = find_inferior_ptid (ecs->ptid);
5138 struct regcache *child_regcache;
5139 CORE_ADDR parent_pc;
5141 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5142 indicating that the displaced stepping of syscall instruction
5143 has been done. Perform cleanup for parent process here. Note
5144 that this operation also cleans up the child process for vfork,
5145 because their pages are shared. */
5146 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
5147 /* Start a new step-over in another thread if there's one
5151 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5153 struct displaced_step_inferior_state *displaced
5154 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
5156 /* Restore scratch pad for child process. */
5157 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5160 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5161 the child's PC is also within the scratchpad. Set the child's PC
5162 to the parent's PC value, which has already been fixed up.
5163 FIXME: we use the parent's aspace here, although we're touching
5164 the child, because the child hasn't been added to the inferior
5165 list yet at this point. */
5168 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5170 parent_inf->aspace);
5171 /* Read PC value of parent process. */
5172 parent_pc = regcache_read_pc (regcache);
5174 if (debug_displaced)
5175 fprintf_unfiltered (gdb_stdlog,
5176 "displaced: write child pc from %s to %s\n",
5178 regcache_read_pc (child_regcache)),
5179 paddress (gdbarch, parent_pc));
5181 regcache_write_pc (child_regcache, parent_pc);
5185 if (!ptid_equal (ecs->ptid, inferior_ptid))
5186 context_switch (ecs->ptid);
5188 /* Immediately detach breakpoints from the child before there's
5189 any chance of letting the user delete breakpoints from the
5190 breakpoint lists. If we don't do this early, it's easy to
5191 leave left over traps in the child, vis: "break foo; catch
5192 fork; c; <fork>; del; c; <child calls foo>". We only follow
5193 the fork on the last `continue', and by that time the
5194 breakpoint at "foo" is long gone from the breakpoint table.
5195 If we vforked, then we don't need to unpatch here, since both
5196 parent and child are sharing the same memory pages; we'll
5197 need to unpatch at follow/detach time instead to be certain
5198 that new breakpoints added between catchpoint hit time and
5199 vfork follow are detached. */
5200 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5202 /* This won't actually modify the breakpoint list, but will
5203 physically remove the breakpoints from the child. */
5204 detach_breakpoints (ecs->ws.value.related_pid);
5207 delete_just_stopped_threads_single_step_breakpoints ();
5209 /* In case the event is caught by a catchpoint, remember that
5210 the event is to be followed at the next resume of the thread,
5211 and not immediately. */
5212 ecs->event_thread->pending_follow = ecs->ws;
5214 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5216 ecs->event_thread->control.stop_bpstat
5217 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5218 stop_pc, ecs->ptid, &ecs->ws);
5220 if (handle_stop_requested (ecs))
5223 /* If no catchpoint triggered for this, then keep going. Note
5224 that we're interested in knowing the bpstat actually causes a
5225 stop, not just if it may explain the signal. Software
5226 watchpoints, for example, always appear in the bpstat. */
5227 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5233 = (follow_fork_mode_string == follow_fork_mode_child);
5235 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5237 should_resume = follow_fork ();
5240 child = ecs->ws.value.related_pid;
5242 /* At this point, the parent is marked running, and the
5243 child is marked stopped. */
5245 /* If not resuming the parent, mark it stopped. */
5246 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5247 set_running (parent, 0);
5249 /* If resuming the child, mark it running. */
5250 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5251 set_running (child, 1);
5253 /* In non-stop mode, also resume the other branch. */
5254 if (!detach_fork && (non_stop
5255 || (sched_multi && target_is_non_stop_p ())))
5258 switch_to_thread (parent);
5260 switch_to_thread (child);
5262 ecs->event_thread = inferior_thread ();
5263 ecs->ptid = inferior_ptid;
5268 switch_to_thread (child);
5270 switch_to_thread (parent);
5272 ecs->event_thread = inferior_thread ();
5273 ecs->ptid = inferior_ptid;
5281 process_event_stop_test (ecs);
5284 case TARGET_WAITKIND_VFORK_DONE:
5285 /* Done with the shared memory region. Re-insert breakpoints in
5286 the parent, and keep going. */
5289 fprintf_unfiltered (gdb_stdlog,
5290 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5292 if (!ptid_equal (ecs->ptid, inferior_ptid))
5293 context_switch (ecs->ptid);
5295 current_inferior ()->waiting_for_vfork_done = 0;
5296 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5298 if (handle_stop_requested (ecs))
5301 /* This also takes care of reinserting breakpoints in the
5302 previously locked inferior. */
5306 case TARGET_WAITKIND_EXECD:
5308 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5310 /* Note we can't read registers yet (the stop_pc), because we
5311 don't yet know the inferior's post-exec architecture.
5312 'stop_pc' is explicitly read below instead. */
5313 if (!ptid_equal (ecs->ptid, inferior_ptid))
5314 switch_to_thread_no_regs (ecs->event_thread);
5316 /* Do whatever is necessary to the parent branch of the vfork. */
5317 handle_vfork_child_exec_or_exit (1);
5319 /* This causes the eventpoints and symbol table to be reset.
5320 Must do this now, before trying to determine whether to
5322 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5324 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5326 /* In follow_exec we may have deleted the original thread and
5327 created a new one. Make sure that the event thread is the
5328 execd thread for that case (this is a nop otherwise). */
5329 ecs->event_thread = inferior_thread ();
5331 ecs->event_thread->control.stop_bpstat
5332 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5333 stop_pc, ecs->ptid, &ecs->ws);
5335 /* Note that this may be referenced from inside
5336 bpstat_stop_status above, through inferior_has_execd. */
5337 xfree (ecs->ws.value.execd_pathname);
5338 ecs->ws.value.execd_pathname = NULL;
5340 if (handle_stop_requested (ecs))
5343 /* If no catchpoint triggered for this, then keep going. */
5344 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5346 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5350 process_event_stop_test (ecs);
5353 /* Be careful not to try to gather much state about a thread
5354 that's in a syscall. It's frequently a losing proposition. */
5355 case TARGET_WAITKIND_SYSCALL_ENTRY:
5357 fprintf_unfiltered (gdb_stdlog,
5358 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5359 /* Getting the current syscall number. */
5360 if (handle_syscall_event (ecs) == 0)
5361 process_event_stop_test (ecs);
5364 /* Before examining the threads further, step this thread to
5365 get it entirely out of the syscall. (We get notice of the
5366 event when the thread is just on the verge of exiting a
5367 syscall. Stepping one instruction seems to get it back
5369 case TARGET_WAITKIND_SYSCALL_RETURN:
5371 fprintf_unfiltered (gdb_stdlog,
5372 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5373 if (handle_syscall_event (ecs) == 0)
5374 process_event_stop_test (ecs);
5377 case TARGET_WAITKIND_STOPPED:
5379 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5380 handle_signal_stop (ecs);
5383 case TARGET_WAITKIND_NO_HISTORY:
5385 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5386 /* Reverse execution: target ran out of history info. */
5388 /* Switch to the stopped thread. */
5389 if (!ptid_equal (ecs->ptid, inferior_ptid))
5390 context_switch (ecs->ptid);
5392 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5394 delete_just_stopped_threads_single_step_breakpoints ();
5395 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5397 if (handle_stop_requested (ecs))
5400 observer_notify_no_history ();
5406 /* A wrapper around handle_inferior_event_1, which also makes sure
5407 that all temporary struct value objects that were created during
5408 the handling of the event get deleted at the end. */
5411 handle_inferior_event (struct execution_control_state *ecs)
5413 struct value *mark = value_mark ();
5415 handle_inferior_event_1 (ecs);
5416 /* Purge all temporary values created during the event handling,
5417 as it could be a long time before we return to the command level
5418 where such values would otherwise be purged. */
5419 value_free_to_mark (mark);
5422 /* Restart threads back to what they were trying to do back when we
5423 paused them for an in-line step-over. The EVENT_THREAD thread is
5427 restart_threads (struct thread_info *event_thread)
5429 struct thread_info *tp;
5431 /* In case the instruction just stepped spawned a new thread. */
5432 update_thread_list ();
5434 ALL_NON_EXITED_THREADS (tp)
5436 if (tp == event_thread)
5439 fprintf_unfiltered (gdb_stdlog,
5440 "infrun: restart threads: "
5441 "[%s] is event thread\n",
5442 target_pid_to_str (tp->ptid));
5446 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5449 fprintf_unfiltered (gdb_stdlog,
5450 "infrun: restart threads: "
5451 "[%s] not meant to be running\n",
5452 target_pid_to_str (tp->ptid));
5459 fprintf_unfiltered (gdb_stdlog,
5460 "infrun: restart threads: [%s] resumed\n",
5461 target_pid_to_str (tp->ptid));
5462 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5466 if (thread_is_in_step_over_chain (tp))
5469 fprintf_unfiltered (gdb_stdlog,
5470 "infrun: restart threads: "
5471 "[%s] needs step-over\n",
5472 target_pid_to_str (tp->ptid));
5473 gdb_assert (!tp->resumed);
5478 if (tp->suspend.waitstatus_pending_p)
5481 fprintf_unfiltered (gdb_stdlog,
5482 "infrun: restart threads: "
5483 "[%s] has pending status\n",
5484 target_pid_to_str (tp->ptid));
5489 gdb_assert (!tp->stop_requested);
5491 /* If some thread needs to start a step-over at this point, it
5492 should still be in the step-over queue, and thus skipped
5494 if (thread_still_needs_step_over (tp))
5496 internal_error (__FILE__, __LINE__,
5497 "thread [%s] needs a step-over, but not in "
5498 "step-over queue\n",
5499 target_pid_to_str (tp->ptid));
5502 if (currently_stepping (tp))
5505 fprintf_unfiltered (gdb_stdlog,
5506 "infrun: restart threads: [%s] was stepping\n",
5507 target_pid_to_str (tp->ptid));
5508 keep_going_stepped_thread (tp);
5512 struct execution_control_state ecss;
5513 struct execution_control_state *ecs = &ecss;
5516 fprintf_unfiltered (gdb_stdlog,
5517 "infrun: restart threads: [%s] continuing\n",
5518 target_pid_to_str (tp->ptid));
5519 reset_ecs (ecs, tp);
5520 switch_to_thread (tp->ptid);
5521 keep_going_pass_signal (ecs);
5526 /* Callback for iterate_over_threads. Find a resumed thread that has
5527 a pending waitstatus. */
5530 resumed_thread_with_pending_status (struct thread_info *tp,
5534 && tp->suspend.waitstatus_pending_p);
5537 /* Called when we get an event that may finish an in-line or
5538 out-of-line (displaced stepping) step-over started previously.
5539 Return true if the event is processed and we should go back to the
5540 event loop; false if the caller should continue processing the
5544 finish_step_over (struct execution_control_state *ecs)
5546 int had_step_over_info;
5548 displaced_step_fixup (ecs->ptid,
5549 ecs->event_thread->suspend.stop_signal);
5551 had_step_over_info = step_over_info_valid_p ();
5553 if (had_step_over_info)
5555 /* If we're stepping over a breakpoint with all threads locked,
5556 then only the thread that was stepped should be reporting
5558 gdb_assert (ecs->event_thread->control.trap_expected);
5560 clear_step_over_info ();
5563 if (!target_is_non_stop_p ())
5566 /* Start a new step-over in another thread if there's one that
5570 /* If we were stepping over a breakpoint before, and haven't started
5571 a new in-line step-over sequence, then restart all other threads
5572 (except the event thread). We can't do this in all-stop, as then
5573 e.g., we wouldn't be able to issue any other remote packet until
5574 these other threads stop. */
5575 if (had_step_over_info && !step_over_info_valid_p ())
5577 struct thread_info *pending;
5579 /* If we only have threads with pending statuses, the restart
5580 below won't restart any thread and so nothing re-inserts the
5581 breakpoint we just stepped over. But we need it inserted
5582 when we later process the pending events, otherwise if
5583 another thread has a pending event for this breakpoint too,
5584 we'd discard its event (because the breakpoint that
5585 originally caused the event was no longer inserted). */
5586 context_switch (ecs->ptid);
5587 insert_breakpoints ();
5589 restart_threads (ecs->event_thread);
5591 /* If we have events pending, go through handle_inferior_event
5592 again, picking up a pending event at random. This avoids
5593 thread starvation. */
5595 /* But not if we just stepped over a watchpoint in order to let
5596 the instruction execute so we can evaluate its expression.
5597 The set of watchpoints that triggered is recorded in the
5598 breakpoint objects themselves (see bp->watchpoint_triggered).
5599 If we processed another event first, that other event could
5600 clobber this info. */
5601 if (ecs->event_thread->stepping_over_watchpoint)
5604 pending = iterate_over_threads (resumed_thread_with_pending_status,
5606 if (pending != NULL)
5608 struct thread_info *tp = ecs->event_thread;
5609 struct regcache *regcache;
5613 fprintf_unfiltered (gdb_stdlog,
5614 "infrun: found resumed threads with "
5615 "pending events, saving status\n");
5618 gdb_assert (pending != tp);
5620 /* Record the event thread's event for later. */
5621 save_waitstatus (tp, &ecs->ws);
5622 /* This was cleared early, by handle_inferior_event. Set it
5623 so this pending event is considered by
5627 gdb_assert (!tp->executing);
5629 regcache = get_thread_regcache (tp->ptid);
5630 tp->suspend.stop_pc = regcache_read_pc (regcache);
5634 fprintf_unfiltered (gdb_stdlog,
5635 "infrun: saved stop_pc=%s for %s "
5636 "(currently_stepping=%d)\n",
5637 paddress (target_gdbarch (),
5638 tp->suspend.stop_pc),
5639 target_pid_to_str (tp->ptid),
5640 currently_stepping (tp));
5643 /* This in-line step-over finished; clear this so we won't
5644 start a new one. This is what handle_signal_stop would
5645 do, if we returned false. */
5646 tp->stepping_over_breakpoint = 0;
5648 /* Wake up the event loop again. */
5649 mark_async_event_handler (infrun_async_inferior_event_token);
5651 prepare_to_wait (ecs);
5659 /* Come here when the program has stopped with a signal. */
5662 handle_signal_stop (struct execution_control_state *ecs)
5664 struct frame_info *frame;
5665 struct gdbarch *gdbarch;
5666 int stopped_by_watchpoint;
5667 enum stop_kind stop_soon;
5670 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5672 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5674 /* Do we need to clean up the state of a thread that has
5675 completed a displaced single-step? (Doing so usually affects
5676 the PC, so do it here, before we set stop_pc.) */
5677 if (finish_step_over (ecs))
5680 /* If we either finished a single-step or hit a breakpoint, but
5681 the user wanted this thread to be stopped, pretend we got a
5682 SIG0 (generic unsignaled stop). */
5683 if (ecs->event_thread->stop_requested
5684 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5685 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5687 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5691 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5692 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5693 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5695 inferior_ptid = ecs->ptid;
5697 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5698 paddress (gdbarch, stop_pc));
5699 if (target_stopped_by_watchpoint ())
5703 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5705 if (target_stopped_data_address (¤t_target, &addr))
5706 fprintf_unfiltered (gdb_stdlog,
5707 "infrun: stopped data address = %s\n",
5708 paddress (gdbarch, addr));
5710 fprintf_unfiltered (gdb_stdlog,
5711 "infrun: (no data address available)\n");
5715 /* This is originated from start_remote(), start_inferior() and
5716 shared libraries hook functions. */
5717 stop_soon = get_inferior_stop_soon (ecs->ptid);
5718 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5720 if (!ptid_equal (ecs->ptid, inferior_ptid))
5721 context_switch (ecs->ptid);
5723 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5724 stop_print_frame = 1;
5729 /* This originates from attach_command(). We need to overwrite
5730 the stop_signal here, because some kernels don't ignore a
5731 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5732 See more comments in inferior.h. On the other hand, if we
5733 get a non-SIGSTOP, report it to the user - assume the backend
5734 will handle the SIGSTOP if it should show up later.
5736 Also consider that the attach is complete when we see a
5737 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5738 target extended-remote report it instead of a SIGSTOP
5739 (e.g. gdbserver). We already rely on SIGTRAP being our
5740 signal, so this is no exception.
5742 Also consider that the attach is complete when we see a
5743 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5744 the target to stop all threads of the inferior, in case the
5745 low level attach operation doesn't stop them implicitly. If
5746 they weren't stopped implicitly, then the stub will report a
5747 GDB_SIGNAL_0, meaning: stopped for no particular reason
5748 other than GDB's request. */
5749 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5750 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5751 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5752 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5754 stop_print_frame = 1;
5756 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5760 /* See if something interesting happened to the non-current thread. If
5761 so, then switch to that thread. */
5762 if (!ptid_equal (ecs->ptid, inferior_ptid))
5765 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5767 context_switch (ecs->ptid);
5769 if (deprecated_context_hook)
5770 deprecated_context_hook (ptid_to_global_thread_id (ecs->ptid));
5773 /* At this point, get hold of the now-current thread's frame. */
5774 frame = get_current_frame ();
5775 gdbarch = get_frame_arch (frame);
5777 /* Pull the single step breakpoints out of the target. */
5778 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5780 struct regcache *regcache;
5781 struct address_space *aspace;
5784 regcache = get_thread_regcache (ecs->ptid);
5785 aspace = get_regcache_aspace (regcache);
5786 pc = regcache_read_pc (regcache);
5788 /* However, before doing so, if this single-step breakpoint was
5789 actually for another thread, set this thread up for moving
5791 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5794 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5798 fprintf_unfiltered (gdb_stdlog,
5799 "infrun: [%s] hit another thread's "
5800 "single-step breakpoint\n",
5801 target_pid_to_str (ecs->ptid));
5803 ecs->hit_singlestep_breakpoint = 1;
5810 fprintf_unfiltered (gdb_stdlog,
5811 "infrun: [%s] hit its "
5812 "single-step breakpoint\n",
5813 target_pid_to_str (ecs->ptid));
5817 delete_just_stopped_threads_single_step_breakpoints ();
5819 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5820 && ecs->event_thread->control.trap_expected
5821 && ecs->event_thread->stepping_over_watchpoint)
5822 stopped_by_watchpoint = 0;
5824 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5826 /* If necessary, step over this watchpoint. We'll be back to display
5828 if (stopped_by_watchpoint
5829 && (target_have_steppable_watchpoint
5830 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5832 /* At this point, we are stopped at an instruction which has
5833 attempted to write to a piece of memory under control of
5834 a watchpoint. The instruction hasn't actually executed
5835 yet. If we were to evaluate the watchpoint expression
5836 now, we would get the old value, and therefore no change
5837 would seem to have occurred.
5839 In order to make watchpoints work `right', we really need
5840 to complete the memory write, and then evaluate the
5841 watchpoint expression. We do this by single-stepping the
5844 It may not be necessary to disable the watchpoint to step over
5845 it. For example, the PA can (with some kernel cooperation)
5846 single step over a watchpoint without disabling the watchpoint.
5848 It is far more common to need to disable a watchpoint to step
5849 the inferior over it. If we have non-steppable watchpoints,
5850 we must disable the current watchpoint; it's simplest to
5851 disable all watchpoints.
5853 Any breakpoint at PC must also be stepped over -- if there's
5854 one, it will have already triggered before the watchpoint
5855 triggered, and we either already reported it to the user, or
5856 it didn't cause a stop and we called keep_going. In either
5857 case, if there was a breakpoint at PC, we must be trying to
5859 ecs->event_thread->stepping_over_watchpoint = 1;
5864 ecs->event_thread->stepping_over_breakpoint = 0;
5865 ecs->event_thread->stepping_over_watchpoint = 0;
5866 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5867 ecs->event_thread->control.stop_step = 0;
5868 stop_print_frame = 1;
5869 stopped_by_random_signal = 0;
5871 /* Hide inlined functions starting here, unless we just performed stepi or
5872 nexti. After stepi and nexti, always show the innermost frame (not any
5873 inline function call sites). */
5874 if (ecs->event_thread->control.step_range_end != 1)
5876 struct address_space *aspace =
5877 get_regcache_aspace (get_thread_regcache (ecs->ptid));
5879 /* skip_inline_frames is expensive, so we avoid it if we can
5880 determine that the address is one where functions cannot have
5881 been inlined. This improves performance with inferiors that
5882 load a lot of shared libraries, because the solib event
5883 breakpoint is defined as the address of a function (i.e. not
5884 inline). Note that we have to check the previous PC as well
5885 as the current one to catch cases when we have just
5886 single-stepped off a breakpoint prior to reinstating it.
5887 Note that we're assuming that the code we single-step to is
5888 not inline, but that's not definitive: there's nothing
5889 preventing the event breakpoint function from containing
5890 inlined code, and the single-step ending up there. If the
5891 user had set a breakpoint on that inlined code, the missing
5892 skip_inline_frames call would break things. Fortunately
5893 that's an extremely unlikely scenario. */
5894 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5895 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5896 && ecs->event_thread->control.trap_expected
5897 && pc_at_non_inline_function (aspace,
5898 ecs->event_thread->prev_pc,
5901 skip_inline_frames (ecs->ptid);
5903 /* Re-fetch current thread's frame in case that invalidated
5905 frame = get_current_frame ();
5906 gdbarch = get_frame_arch (frame);
5910 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5911 && ecs->event_thread->control.trap_expected
5912 && gdbarch_single_step_through_delay_p (gdbarch)
5913 && currently_stepping (ecs->event_thread))
5915 /* We're trying to step off a breakpoint. Turns out that we're
5916 also on an instruction that needs to be stepped multiple
5917 times before it's been fully executing. E.g., architectures
5918 with a delay slot. It needs to be stepped twice, once for
5919 the instruction and once for the delay slot. */
5920 int step_through_delay
5921 = gdbarch_single_step_through_delay (gdbarch, frame);
5923 if (debug_infrun && step_through_delay)
5924 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5925 if (ecs->event_thread->control.step_range_end == 0
5926 && step_through_delay)
5928 /* The user issued a continue when stopped at a breakpoint.
5929 Set up for another trap and get out of here. */
5930 ecs->event_thread->stepping_over_breakpoint = 1;
5934 else if (step_through_delay)
5936 /* The user issued a step when stopped at a breakpoint.
5937 Maybe we should stop, maybe we should not - the delay
5938 slot *might* correspond to a line of source. In any
5939 case, don't decide that here, just set
5940 ecs->stepping_over_breakpoint, making sure we
5941 single-step again before breakpoints are re-inserted. */
5942 ecs->event_thread->stepping_over_breakpoint = 1;
5946 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5947 handles this event. */
5948 ecs->event_thread->control.stop_bpstat
5949 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5950 stop_pc, ecs->ptid, &ecs->ws);
5952 /* Following in case break condition called a
5954 stop_print_frame = 1;
5956 /* This is where we handle "moribund" watchpoints. Unlike
5957 software breakpoints traps, hardware watchpoint traps are
5958 always distinguishable from random traps. If no high-level
5959 watchpoint is associated with the reported stop data address
5960 anymore, then the bpstat does not explain the signal ---
5961 simply make sure to ignore it if `stopped_by_watchpoint' is
5965 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5966 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5968 && stopped_by_watchpoint)
5969 fprintf_unfiltered (gdb_stdlog,
5970 "infrun: no user watchpoint explains "
5971 "watchpoint SIGTRAP, ignoring\n");
5973 /* NOTE: cagney/2003-03-29: These checks for a random signal
5974 at one stage in the past included checks for an inferior
5975 function call's call dummy's return breakpoint. The original
5976 comment, that went with the test, read:
5978 ``End of a stack dummy. Some systems (e.g. Sony news) give
5979 another signal besides SIGTRAP, so check here as well as
5982 If someone ever tries to get call dummys on a
5983 non-executable stack to work (where the target would stop
5984 with something like a SIGSEGV), then those tests might need
5985 to be re-instated. Given, however, that the tests were only
5986 enabled when momentary breakpoints were not being used, I
5987 suspect that it won't be the case.
5989 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5990 be necessary for call dummies on a non-executable stack on
5993 /* See if the breakpoints module can explain the signal. */
5995 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5996 ecs->event_thread->suspend.stop_signal);
5998 /* Maybe this was a trap for a software breakpoint that has since
6000 if (random_signal && target_stopped_by_sw_breakpoint ())
6002 if (program_breakpoint_here_p (gdbarch, stop_pc))
6004 struct regcache *regcache;
6007 /* Re-adjust PC to what the program would see if GDB was not
6009 regcache = get_thread_regcache (ecs->event_thread->ptid);
6010 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
6013 gdb::optional<scoped_restore_tmpl<int>>
6014 restore_operation_disable;
6016 if (record_full_is_used ())
6017 restore_operation_disable.emplace
6018 (record_full_gdb_operation_disable_set ());
6020 regcache_write_pc (regcache, stop_pc + decr_pc);
6025 /* A delayed software breakpoint event. Ignore the trap. */
6027 fprintf_unfiltered (gdb_stdlog,
6028 "infrun: delayed software breakpoint "
6029 "trap, ignoring\n");
6034 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6035 has since been removed. */
6036 if (random_signal && target_stopped_by_hw_breakpoint ())
6038 /* A delayed hardware breakpoint event. Ignore the trap. */
6040 fprintf_unfiltered (gdb_stdlog,
6041 "infrun: delayed hardware breakpoint/watchpoint "
6042 "trap, ignoring\n");
6046 /* If not, perhaps stepping/nexting can. */
6048 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6049 && currently_stepping (ecs->event_thread));
6051 /* Perhaps the thread hit a single-step breakpoint of _another_
6052 thread. Single-step breakpoints are transparent to the
6053 breakpoints module. */
6055 random_signal = !ecs->hit_singlestep_breakpoint;
6057 /* No? Perhaps we got a moribund watchpoint. */
6059 random_signal = !stopped_by_watchpoint;
6061 /* Always stop if the user explicitly requested this thread to
6063 if (ecs->event_thread->stop_requested)
6067 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6070 /* For the program's own signals, act according to
6071 the signal handling tables. */
6075 /* Signal not for debugging purposes. */
6076 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6077 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6080 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6081 gdb_signal_to_symbol_string (stop_signal));
6083 stopped_by_random_signal = 1;
6085 /* Always stop on signals if we're either just gaining control
6086 of the program, or the user explicitly requested this thread
6087 to remain stopped. */
6088 if (stop_soon != NO_STOP_QUIETLY
6089 || ecs->event_thread->stop_requested
6091 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6097 /* Notify observers the signal has "handle print" set. Note we
6098 returned early above if stopping; normal_stop handles the
6099 printing in that case. */
6100 if (signal_print[ecs->event_thread->suspend.stop_signal])
6102 /* The signal table tells us to print about this signal. */
6103 target_terminal::ours_for_output ();
6104 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
6105 target_terminal::inferior ();
6108 /* Clear the signal if it should not be passed. */
6109 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6110 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6112 if (ecs->event_thread->prev_pc == stop_pc
6113 && ecs->event_thread->control.trap_expected
6114 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6116 /* We were just starting a new sequence, attempting to
6117 single-step off of a breakpoint and expecting a SIGTRAP.
6118 Instead this signal arrives. This signal will take us out
6119 of the stepping range so GDB needs to remember to, when
6120 the signal handler returns, resume stepping off that
6122 /* To simplify things, "continue" is forced to use the same
6123 code paths as single-step - set a breakpoint at the
6124 signal return address and then, once hit, step off that
6127 fprintf_unfiltered (gdb_stdlog,
6128 "infrun: signal arrived while stepping over "
6131 insert_hp_step_resume_breakpoint_at_frame (frame);
6132 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6133 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6134 ecs->event_thread->control.trap_expected = 0;
6136 /* If we were nexting/stepping some other thread, switch to
6137 it, so that we don't continue it, losing control. */
6138 if (!switch_back_to_stepped_thread (ecs))
6143 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6144 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6145 || ecs->event_thread->control.step_range_end == 1)
6146 && frame_id_eq (get_stack_frame_id (frame),
6147 ecs->event_thread->control.step_stack_frame_id)
6148 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6150 /* The inferior is about to take a signal that will take it
6151 out of the single step range. Set a breakpoint at the
6152 current PC (which is presumably where the signal handler
6153 will eventually return) and then allow the inferior to
6156 Note that this is only needed for a signal delivered
6157 while in the single-step range. Nested signals aren't a
6158 problem as they eventually all return. */
6160 fprintf_unfiltered (gdb_stdlog,
6161 "infrun: signal may take us out of "
6162 "single-step range\n");
6164 clear_step_over_info ();
6165 insert_hp_step_resume_breakpoint_at_frame (frame);
6166 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6167 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6168 ecs->event_thread->control.trap_expected = 0;
6173 /* Note: step_resume_breakpoint may be non-NULL. This occures
6174 when either there's a nested signal, or when there's a
6175 pending signal enabled just as the signal handler returns
6176 (leaving the inferior at the step-resume-breakpoint without
6177 actually executing it). Either way continue until the
6178 breakpoint is really hit. */
6180 if (!switch_back_to_stepped_thread (ecs))
6183 fprintf_unfiltered (gdb_stdlog,
6184 "infrun: random signal, keep going\n");
6191 process_event_stop_test (ecs);
6194 /* Come here when we've got some debug event / signal we can explain
6195 (IOW, not a random signal), and test whether it should cause a
6196 stop, or whether we should resume the inferior (transparently).
6197 E.g., could be a breakpoint whose condition evaluates false; we
6198 could be still stepping within the line; etc. */
6201 process_event_stop_test (struct execution_control_state *ecs)
6203 struct symtab_and_line stop_pc_sal;
6204 struct frame_info *frame;
6205 struct gdbarch *gdbarch;
6206 CORE_ADDR jmp_buf_pc;
6207 struct bpstat_what what;
6209 /* Handle cases caused by hitting a breakpoint. */
6211 frame = get_current_frame ();
6212 gdbarch = get_frame_arch (frame);
6214 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6216 if (what.call_dummy)
6218 stop_stack_dummy = what.call_dummy;
6221 /* A few breakpoint types have callbacks associated (e.g.,
6222 bp_jit_event). Run them now. */
6223 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6225 /* If we hit an internal event that triggers symbol changes, the
6226 current frame will be invalidated within bpstat_what (e.g., if we
6227 hit an internal solib event). Re-fetch it. */
6228 frame = get_current_frame ();
6229 gdbarch = get_frame_arch (frame);
6231 switch (what.main_action)
6233 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6234 /* If we hit the breakpoint at longjmp while stepping, we
6235 install a momentary breakpoint at the target of the
6239 fprintf_unfiltered (gdb_stdlog,
6240 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6242 ecs->event_thread->stepping_over_breakpoint = 1;
6244 if (what.is_longjmp)
6246 struct value *arg_value;
6248 /* If we set the longjmp breakpoint via a SystemTap probe,
6249 then use it to extract the arguments. The destination PC
6250 is the third argument to the probe. */
6251 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6254 jmp_buf_pc = value_as_address (arg_value);
6255 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6257 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6258 || !gdbarch_get_longjmp_target (gdbarch,
6259 frame, &jmp_buf_pc))
6262 fprintf_unfiltered (gdb_stdlog,
6263 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6264 "(!gdbarch_get_longjmp_target)\n");
6269 /* Insert a breakpoint at resume address. */
6270 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6273 check_exception_resume (ecs, frame);
6277 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6279 struct frame_info *init_frame;
6281 /* There are several cases to consider.
6283 1. The initiating frame no longer exists. In this case we
6284 must stop, because the exception or longjmp has gone too
6287 2. The initiating frame exists, and is the same as the
6288 current frame. We stop, because the exception or longjmp
6291 3. The initiating frame exists and is different from the
6292 current frame. This means the exception or longjmp has
6293 been caught beneath the initiating frame, so keep going.
6295 4. longjmp breakpoint has been placed just to protect
6296 against stale dummy frames and user is not interested in
6297 stopping around longjmps. */
6300 fprintf_unfiltered (gdb_stdlog,
6301 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6303 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6305 delete_exception_resume_breakpoint (ecs->event_thread);
6307 if (what.is_longjmp)
6309 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6311 if (!frame_id_p (ecs->event_thread->initiating_frame))
6319 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6323 struct frame_id current_id
6324 = get_frame_id (get_current_frame ());
6325 if (frame_id_eq (current_id,
6326 ecs->event_thread->initiating_frame))
6328 /* Case 2. Fall through. */
6338 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6340 delete_step_resume_breakpoint (ecs->event_thread);
6342 end_stepping_range (ecs);
6346 case BPSTAT_WHAT_SINGLE:
6348 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6349 ecs->event_thread->stepping_over_breakpoint = 1;
6350 /* Still need to check other stuff, at least the case where we
6351 are stepping and step out of the right range. */
6354 case BPSTAT_WHAT_STEP_RESUME:
6356 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6358 delete_step_resume_breakpoint (ecs->event_thread);
6359 if (ecs->event_thread->control.proceed_to_finish
6360 && execution_direction == EXEC_REVERSE)
6362 struct thread_info *tp = ecs->event_thread;
6364 /* We are finishing a function in reverse, and just hit the
6365 step-resume breakpoint at the start address of the
6366 function, and we're almost there -- just need to back up
6367 by one more single-step, which should take us back to the
6369 tp->control.step_range_start = tp->control.step_range_end = 1;
6373 fill_in_stop_func (gdbarch, ecs);
6374 if (stop_pc == ecs->stop_func_start
6375 && execution_direction == EXEC_REVERSE)
6377 /* We are stepping over a function call in reverse, and just
6378 hit the step-resume breakpoint at the start address of
6379 the function. Go back to single-stepping, which should
6380 take us back to the function call. */
6381 ecs->event_thread->stepping_over_breakpoint = 1;
6387 case BPSTAT_WHAT_STOP_NOISY:
6389 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6390 stop_print_frame = 1;
6392 /* Assume the thread stopped for a breapoint. We'll still check
6393 whether a/the breakpoint is there when the thread is next
6395 ecs->event_thread->stepping_over_breakpoint = 1;
6400 case BPSTAT_WHAT_STOP_SILENT:
6402 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6403 stop_print_frame = 0;
6405 /* Assume the thread stopped for a breapoint. We'll still check
6406 whether a/the breakpoint is there when the thread is next
6408 ecs->event_thread->stepping_over_breakpoint = 1;
6412 case BPSTAT_WHAT_HP_STEP_RESUME:
6414 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6416 delete_step_resume_breakpoint (ecs->event_thread);
6417 if (ecs->event_thread->step_after_step_resume_breakpoint)
6419 /* Back when the step-resume breakpoint was inserted, we
6420 were trying to single-step off a breakpoint. Go back to
6422 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6423 ecs->event_thread->stepping_over_breakpoint = 1;
6429 case BPSTAT_WHAT_KEEP_CHECKING:
6433 /* If we stepped a permanent breakpoint and we had a high priority
6434 step-resume breakpoint for the address we stepped, but we didn't
6435 hit it, then we must have stepped into the signal handler. The
6436 step-resume was only necessary to catch the case of _not_
6437 stepping into the handler, so delete it, and fall through to
6438 checking whether the step finished. */
6439 if (ecs->event_thread->stepped_breakpoint)
6441 struct breakpoint *sr_bp
6442 = ecs->event_thread->control.step_resume_breakpoint;
6445 && sr_bp->loc->permanent
6446 && sr_bp->type == bp_hp_step_resume
6447 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6450 fprintf_unfiltered (gdb_stdlog,
6451 "infrun: stepped permanent breakpoint, stopped in "
6453 delete_step_resume_breakpoint (ecs->event_thread);
6454 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6458 /* We come here if we hit a breakpoint but should not stop for it.
6459 Possibly we also were stepping and should stop for that. So fall
6460 through and test for stepping. But, if not stepping, do not
6463 /* In all-stop mode, if we're currently stepping but have stopped in
6464 some other thread, we need to switch back to the stepped thread. */
6465 if (switch_back_to_stepped_thread (ecs))
6468 if (ecs->event_thread->control.step_resume_breakpoint)
6471 fprintf_unfiltered (gdb_stdlog,
6472 "infrun: step-resume breakpoint is inserted\n");
6474 /* Having a step-resume breakpoint overrides anything
6475 else having to do with stepping commands until
6476 that breakpoint is reached. */
6481 if (ecs->event_thread->control.step_range_end == 0)
6484 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6485 /* Likewise if we aren't even stepping. */
6490 /* Re-fetch current thread's frame in case the code above caused
6491 the frame cache to be re-initialized, making our FRAME variable
6492 a dangling pointer. */
6493 frame = get_current_frame ();
6494 gdbarch = get_frame_arch (frame);
6495 fill_in_stop_func (gdbarch, ecs);
6497 /* If stepping through a line, keep going if still within it.
6499 Note that step_range_end is the address of the first instruction
6500 beyond the step range, and NOT the address of the last instruction
6503 Note also that during reverse execution, we may be stepping
6504 through a function epilogue and therefore must detect when
6505 the current-frame changes in the middle of a line. */
6507 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6508 && (execution_direction != EXEC_REVERSE
6509 || frame_id_eq (get_frame_id (frame),
6510 ecs->event_thread->control.step_frame_id)))
6514 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6515 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6516 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6518 /* Tentatively re-enable range stepping; `resume' disables it if
6519 necessary (e.g., if we're stepping over a breakpoint or we
6520 have software watchpoints). */
6521 ecs->event_thread->control.may_range_step = 1;
6523 /* When stepping backward, stop at beginning of line range
6524 (unless it's the function entry point, in which case
6525 keep going back to the call point). */
6526 if (stop_pc == ecs->event_thread->control.step_range_start
6527 && stop_pc != ecs->stop_func_start
6528 && execution_direction == EXEC_REVERSE)
6529 end_stepping_range (ecs);
6536 /* We stepped out of the stepping range. */
6538 /* If we are stepping at the source level and entered the runtime
6539 loader dynamic symbol resolution code...
6541 EXEC_FORWARD: we keep on single stepping until we exit the run
6542 time loader code and reach the callee's address.
6544 EXEC_REVERSE: we've already executed the callee (backward), and
6545 the runtime loader code is handled just like any other
6546 undebuggable function call. Now we need only keep stepping
6547 backward through the trampoline code, and that's handled further
6548 down, so there is nothing for us to do here. */
6550 if (execution_direction != EXEC_REVERSE
6551 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6552 && in_solib_dynsym_resolve_code (stop_pc))
6554 CORE_ADDR pc_after_resolver =
6555 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6558 fprintf_unfiltered (gdb_stdlog,
6559 "infrun: stepped into dynsym resolve code\n");
6561 if (pc_after_resolver)
6563 /* Set up a step-resume breakpoint at the address
6564 indicated by SKIP_SOLIB_RESOLVER. */
6565 symtab_and_line sr_sal;
6566 sr_sal.pc = pc_after_resolver;
6567 sr_sal.pspace = get_frame_program_space (frame);
6569 insert_step_resume_breakpoint_at_sal (gdbarch,
6570 sr_sal, null_frame_id);
6577 if (ecs->event_thread->control.step_range_end != 1
6578 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6579 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6580 && get_frame_type (frame) == SIGTRAMP_FRAME)
6583 fprintf_unfiltered (gdb_stdlog,
6584 "infrun: stepped into signal trampoline\n");
6585 /* The inferior, while doing a "step" or "next", has ended up in
6586 a signal trampoline (either by a signal being delivered or by
6587 the signal handler returning). Just single-step until the
6588 inferior leaves the trampoline (either by calling the handler
6594 /* If we're in the return path from a shared library trampoline,
6595 we want to proceed through the trampoline when stepping. */
6596 /* macro/2012-04-25: This needs to come before the subroutine
6597 call check below as on some targets return trampolines look
6598 like subroutine calls (MIPS16 return thunks). */
6599 if (gdbarch_in_solib_return_trampoline (gdbarch,
6600 stop_pc, ecs->stop_func_name)
6601 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6603 /* Determine where this trampoline returns. */
6604 CORE_ADDR real_stop_pc;
6606 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6609 fprintf_unfiltered (gdb_stdlog,
6610 "infrun: stepped into solib return tramp\n");
6612 /* Only proceed through if we know where it's going. */
6615 /* And put the step-breakpoint there and go until there. */
6616 symtab_and_line sr_sal;
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 /* Normal function call return (static or dynamic). */
6715 symtab_and_line sr_sal;
6716 sr_sal.pc = ecs->stop_func_start;
6717 sr_sal.pspace = get_frame_program_space (frame);
6718 insert_step_resume_breakpoint_at_sal (gdbarch,
6719 sr_sal, null_frame_id);
6723 insert_step_resume_breakpoint_at_caller (frame);
6729 /* If we are in a function call trampoline (a stub between the
6730 calling routine and the real function), locate the real
6731 function. That's what tells us (a) whether we want to step
6732 into it at all, and (b) what prologue we want to run to the
6733 end of, if we do step into it. */
6734 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6735 if (real_stop_pc == 0)
6736 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6737 if (real_stop_pc != 0)
6738 ecs->stop_func_start = real_stop_pc;
6740 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6742 symtab_and_line sr_sal;
6743 sr_sal.pc = ecs->stop_func_start;
6744 sr_sal.pspace = get_frame_program_space (frame);
6746 insert_step_resume_breakpoint_at_sal (gdbarch,
6747 sr_sal, null_frame_id);
6752 /* If we have line number information for the function we are
6753 thinking of stepping into and the function isn't on the skip
6756 If there are several symtabs at that PC (e.g. with include
6757 files), just want to know whether *any* of them have line
6758 numbers. find_pc_line handles this. */
6760 struct symtab_and_line tmp_sal;
6762 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6763 if (tmp_sal.line != 0
6764 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6767 if (execution_direction == EXEC_REVERSE)
6768 handle_step_into_function_backward (gdbarch, ecs);
6770 handle_step_into_function (gdbarch, ecs);
6775 /* If we have no line number and the step-stop-if-no-debug is
6776 set, we stop the step so that the user has a chance to switch
6777 in assembly mode. */
6778 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6779 && step_stop_if_no_debug)
6781 end_stepping_range (ecs);
6785 if (execution_direction == EXEC_REVERSE)
6787 /* If we're already at the start of the function, we've either just
6788 stepped backward into a single instruction function without line
6789 number info, or stepped back out of a signal handler to the first
6790 instruction of the function without line number info. Just keep
6791 going, which will single-step back to the caller. */
6792 if (ecs->stop_func_start != stop_pc)
6794 /* Set a breakpoint at callee's start address.
6795 From there we can step once and be back in the caller. */
6796 symtab_and_line sr_sal;
6797 sr_sal.pc = ecs->stop_func_start;
6798 sr_sal.pspace = get_frame_program_space (frame);
6799 insert_step_resume_breakpoint_at_sal (gdbarch,
6800 sr_sal, null_frame_id);
6804 /* Set a breakpoint at callee's return address (the address
6805 at which the caller will resume). */
6806 insert_step_resume_breakpoint_at_caller (frame);
6812 /* Reverse stepping through solib trampolines. */
6814 if (execution_direction == EXEC_REVERSE
6815 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6817 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6818 || (ecs->stop_func_start == 0
6819 && in_solib_dynsym_resolve_code (stop_pc)))
6821 /* Any solib trampoline code can be handled in reverse
6822 by simply continuing to single-step. We have already
6823 executed the solib function (backwards), and a few
6824 steps will take us back through the trampoline to the
6829 else if (in_solib_dynsym_resolve_code (stop_pc))
6831 /* Stepped backward into the solib dynsym resolver.
6832 Set a breakpoint at its start and continue, then
6833 one more step will take us out. */
6834 symtab_and_line sr_sal;
6835 sr_sal.pc = ecs->stop_func_start;
6836 sr_sal.pspace = get_frame_program_space (frame);
6837 insert_step_resume_breakpoint_at_sal (gdbarch,
6838 sr_sal, null_frame_id);
6844 stop_pc_sal = find_pc_line (stop_pc, 0);
6846 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6847 the trampoline processing logic, however, there are some trampolines
6848 that have no names, so we should do trampoline handling first. */
6849 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6850 && ecs->stop_func_name == NULL
6851 && stop_pc_sal.line == 0)
6854 fprintf_unfiltered (gdb_stdlog,
6855 "infrun: stepped into undebuggable function\n");
6857 /* The inferior just stepped into, or returned to, an
6858 undebuggable function (where there is no debugging information
6859 and no line number corresponding to the address where the
6860 inferior stopped). Since we want to skip this kind of code,
6861 we keep going until the inferior returns from this
6862 function - unless the user has asked us not to (via
6863 set step-mode) or we no longer know how to get back
6864 to the call site. */
6865 if (step_stop_if_no_debug
6866 || !frame_id_p (frame_unwind_caller_id (frame)))
6868 /* If we have no line number and the step-stop-if-no-debug
6869 is set, we stop the step so that the user has a chance to
6870 switch in assembly mode. */
6871 end_stepping_range (ecs);
6876 /* Set a breakpoint at callee's return address (the address
6877 at which the caller will resume). */
6878 insert_step_resume_breakpoint_at_caller (frame);
6884 if (ecs->event_thread->control.step_range_end == 1)
6886 /* It is stepi or nexti. We always want to stop stepping after
6889 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6890 end_stepping_range (ecs);
6894 if (stop_pc_sal.line == 0)
6896 /* We have no line number information. That means to stop
6897 stepping (does this always happen right after one instruction,
6898 when we do "s" in a function with no line numbers,
6899 or can this happen as a result of a return or longjmp?). */
6901 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6902 end_stepping_range (ecs);
6906 /* Look for "calls" to inlined functions, part one. If the inline
6907 frame machinery detected some skipped call sites, we have entered
6908 a new inline function. */
6910 if (frame_id_eq (get_frame_id (get_current_frame ()),
6911 ecs->event_thread->control.step_frame_id)
6912 && inline_skipped_frames (ecs->ptid))
6915 fprintf_unfiltered (gdb_stdlog,
6916 "infrun: stepped into inlined function\n");
6918 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6920 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6922 /* For "step", we're going to stop. But if the call site
6923 for this inlined function is on the same source line as
6924 we were previously stepping, go down into the function
6925 first. Otherwise stop at the call site. */
6927 if (call_sal.line == ecs->event_thread->current_line
6928 && call_sal.symtab == ecs->event_thread->current_symtab)
6929 step_into_inline_frame (ecs->ptid);
6931 end_stepping_range (ecs);
6936 /* For "next", we should stop at the call site if it is on a
6937 different source line. Otherwise continue through the
6938 inlined function. */
6939 if (call_sal.line == ecs->event_thread->current_line
6940 && call_sal.symtab == ecs->event_thread->current_symtab)
6943 end_stepping_range (ecs);
6948 /* Look for "calls" to inlined functions, part two. If we are still
6949 in the same real function we were stepping through, but we have
6950 to go further up to find the exact frame ID, we are stepping
6951 through a more inlined call beyond its call site. */
6953 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6954 && !frame_id_eq (get_frame_id (get_current_frame ()),
6955 ecs->event_thread->control.step_frame_id)
6956 && stepped_in_from (get_current_frame (),
6957 ecs->event_thread->control.step_frame_id))
6960 fprintf_unfiltered (gdb_stdlog,
6961 "infrun: stepping through inlined function\n");
6963 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6966 end_stepping_range (ecs);
6970 if ((stop_pc == stop_pc_sal.pc)
6971 && (ecs->event_thread->current_line != stop_pc_sal.line
6972 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6974 /* We are at the start of a different line. So stop. Note that
6975 we don't stop if we step into the middle of a different line.
6976 That is said to make things like for (;;) statements work
6979 fprintf_unfiltered (gdb_stdlog,
6980 "infrun: stepped to a different line\n");
6981 end_stepping_range (ecs);
6985 /* We aren't done stepping.
6987 Optimize by setting the stepping range to the line.
6988 (We might not be in the original line, but if we entered a
6989 new line in mid-statement, we continue stepping. This makes
6990 things like for(;;) statements work better.) */
6992 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6993 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6994 ecs->event_thread->control.may_range_step = 1;
6995 set_step_info (frame, stop_pc_sal);
6998 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
7002 /* In all-stop mode, if we're currently stepping but have stopped in
7003 some other thread, we may need to switch back to the stepped
7004 thread. Returns true we set the inferior running, false if we left
7005 it stopped (and the event needs further processing). */
7008 switch_back_to_stepped_thread (struct execution_control_state *ecs)
7010 if (!target_is_non_stop_p ())
7012 struct thread_info *tp;
7013 struct thread_info *stepping_thread;
7015 /* If any thread is blocked on some internal breakpoint, and we
7016 simply need to step over that breakpoint to get it going
7017 again, do that first. */
7019 /* However, if we see an event for the stepping thread, then we
7020 know all other threads have been moved past their breakpoints
7021 already. Let the caller check whether the step is finished,
7022 etc., before deciding to move it past a breakpoint. */
7023 if (ecs->event_thread->control.step_range_end != 0)
7026 /* Check if the current thread is blocked on an incomplete
7027 step-over, interrupted by a random signal. */
7028 if (ecs->event_thread->control.trap_expected
7029 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7033 fprintf_unfiltered (gdb_stdlog,
7034 "infrun: need to finish step-over of [%s]\n",
7035 target_pid_to_str (ecs->event_thread->ptid));
7041 /* Check if the current thread is blocked by a single-step
7042 breakpoint of another thread. */
7043 if (ecs->hit_singlestep_breakpoint)
7047 fprintf_unfiltered (gdb_stdlog,
7048 "infrun: need to step [%s] over single-step "
7050 target_pid_to_str (ecs->ptid));
7056 /* If this thread needs yet another step-over (e.g., stepping
7057 through a delay slot), do it first before moving on to
7059 if (thread_still_needs_step_over (ecs->event_thread))
7063 fprintf_unfiltered (gdb_stdlog,
7064 "infrun: thread [%s] still needs step-over\n",
7065 target_pid_to_str (ecs->event_thread->ptid));
7071 /* If scheduler locking applies even if not stepping, there's no
7072 need to walk over threads. Above we've checked whether the
7073 current thread is stepping. If some other thread not the
7074 event thread is stepping, then it must be that scheduler
7075 locking is not in effect. */
7076 if (schedlock_applies (ecs->event_thread))
7079 /* Otherwise, we no longer expect a trap in the current thread.
7080 Clear the trap_expected flag before switching back -- this is
7081 what keep_going does as well, if we call it. */
7082 ecs->event_thread->control.trap_expected = 0;
7084 /* Likewise, clear the signal if it should not be passed. */
7085 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7086 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7088 /* Do all pending step-overs before actually proceeding with
7090 if (start_step_over ())
7092 prepare_to_wait (ecs);
7096 /* Look for the stepping/nexting thread. */
7097 stepping_thread = NULL;
7099 ALL_NON_EXITED_THREADS (tp)
7101 /* Ignore threads of processes the caller is not
7104 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
7107 /* When stepping over a breakpoint, we lock all threads
7108 except the one that needs to move past the breakpoint.
7109 If a non-event thread has this set, the "incomplete
7110 step-over" check above should have caught it earlier. */
7111 if (tp->control.trap_expected)
7113 internal_error (__FILE__, __LINE__,
7114 "[%s] has inconsistent state: "
7115 "trap_expected=%d\n",
7116 target_pid_to_str (tp->ptid),
7117 tp->control.trap_expected);
7120 /* Did we find the stepping thread? */
7121 if (tp->control.step_range_end)
7123 /* Yep. There should only one though. */
7124 gdb_assert (stepping_thread == NULL);
7126 /* The event thread is handled at the top, before we
7128 gdb_assert (tp != ecs->event_thread);
7130 /* If some thread other than the event thread is
7131 stepping, then scheduler locking can't be in effect,
7132 otherwise we wouldn't have resumed the current event
7133 thread in the first place. */
7134 gdb_assert (!schedlock_applies (tp));
7136 stepping_thread = tp;
7140 if (stepping_thread != NULL)
7143 fprintf_unfiltered (gdb_stdlog,
7144 "infrun: switching back to stepped thread\n");
7146 if (keep_going_stepped_thread (stepping_thread))
7148 prepare_to_wait (ecs);
7157 /* Set a previously stepped thread back to stepping. Returns true on
7158 success, false if the resume is not possible (e.g., the thread
7162 keep_going_stepped_thread (struct thread_info *tp)
7164 struct frame_info *frame;
7165 struct execution_control_state ecss;
7166 struct execution_control_state *ecs = &ecss;
7168 /* If the stepping thread exited, then don't try to switch back and
7169 resume it, which could fail in several different ways depending
7170 on the target. Instead, just keep going.
7172 We can find a stepping dead thread in the thread list in two
7175 - The target supports thread exit events, and when the target
7176 tries to delete the thread from the thread list, inferior_ptid
7177 pointed at the exiting thread. In such case, calling
7178 delete_thread does not really remove the thread from the list;
7179 instead, the thread is left listed, with 'exited' state.
7181 - The target's debug interface does not support thread exit
7182 events, and so we have no idea whatsoever if the previously
7183 stepping thread is still alive. For that reason, we need to
7184 synchronously query the target now. */
7186 if (is_exited (tp->ptid)
7187 || !target_thread_alive (tp->ptid))
7190 fprintf_unfiltered (gdb_stdlog,
7191 "infrun: not resuming previously "
7192 "stepped thread, it has vanished\n");
7194 delete_thread (tp->ptid);
7199 fprintf_unfiltered (gdb_stdlog,
7200 "infrun: resuming previously stepped thread\n");
7202 reset_ecs (ecs, tp);
7203 switch_to_thread (tp->ptid);
7205 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7206 frame = get_current_frame ();
7208 /* If the PC of the thread we were trying to single-step has
7209 changed, then that thread has trapped or been signaled, but the
7210 event has not been reported to GDB yet. Re-poll the target
7211 looking for this particular thread's event (i.e. temporarily
7212 enable schedlock) by:
7214 - setting a break at the current PC
7215 - resuming that particular thread, only (by setting trap
7218 This prevents us continuously moving the single-step breakpoint
7219 forward, one instruction at a time, overstepping. */
7221 if (stop_pc != tp->prev_pc)
7226 fprintf_unfiltered (gdb_stdlog,
7227 "infrun: expected thread advanced also (%s -> %s)\n",
7228 paddress (target_gdbarch (), tp->prev_pc),
7229 paddress (target_gdbarch (), stop_pc));
7231 /* Clear the info of the previous step-over, as it's no longer
7232 valid (if the thread was trying to step over a breakpoint, it
7233 has already succeeded). It's what keep_going would do too,
7234 if we called it. Do this before trying to insert the sss
7235 breakpoint, otherwise if we were previously trying to step
7236 over this exact address in another thread, the breakpoint is
7238 clear_step_over_info ();
7239 tp->control.trap_expected = 0;
7241 insert_single_step_breakpoint (get_frame_arch (frame),
7242 get_frame_address_space (frame),
7246 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7247 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7252 fprintf_unfiltered (gdb_stdlog,
7253 "infrun: expected thread still hasn't advanced\n");
7255 keep_going_pass_signal (ecs);
7260 /* Is thread TP in the middle of (software or hardware)
7261 single-stepping? (Note the result of this function must never be
7262 passed directly as target_resume's STEP parameter.) */
7265 currently_stepping (struct thread_info *tp)
7267 return ((tp->control.step_range_end
7268 && tp->control.step_resume_breakpoint == NULL)
7269 || tp->control.trap_expected
7270 || tp->stepped_breakpoint
7271 || bpstat_should_step ());
7274 /* Inferior has stepped into a subroutine call with source code that
7275 we should not step over. Do step to the first line of code in
7279 handle_step_into_function (struct gdbarch *gdbarch,
7280 struct execution_control_state *ecs)
7282 fill_in_stop_func (gdbarch, ecs);
7284 compunit_symtab *cust = find_pc_compunit_symtab (stop_pc);
7285 if (cust != NULL && compunit_language (cust) != language_asm)
7286 ecs->stop_func_start
7287 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7289 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7290 /* Use the step_resume_break to step until the end of the prologue,
7291 even if that involves jumps (as it seems to on the vax under
7293 /* If the prologue ends in the middle of a source line, continue to
7294 the end of that source line (if it is still within the function).
7295 Otherwise, just go to end of prologue. */
7296 if (stop_func_sal.end
7297 && stop_func_sal.pc != ecs->stop_func_start
7298 && stop_func_sal.end < ecs->stop_func_end)
7299 ecs->stop_func_start = stop_func_sal.end;
7301 /* Architectures which require breakpoint adjustment might not be able
7302 to place a breakpoint at the computed address. If so, the test
7303 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7304 ecs->stop_func_start to an address at which a breakpoint may be
7305 legitimately placed.
7307 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7308 made, GDB will enter an infinite loop when stepping through
7309 optimized code consisting of VLIW instructions which contain
7310 subinstructions corresponding to different source lines. On
7311 FR-V, it's not permitted to place a breakpoint on any but the
7312 first subinstruction of a VLIW instruction. When a breakpoint is
7313 set, GDB will adjust the breakpoint address to the beginning of
7314 the VLIW instruction. Thus, we need to make the corresponding
7315 adjustment here when computing the stop address. */
7317 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7319 ecs->stop_func_start
7320 = gdbarch_adjust_breakpoint_address (gdbarch,
7321 ecs->stop_func_start);
7324 if (ecs->stop_func_start == stop_pc)
7326 /* We are already there: stop now. */
7327 end_stepping_range (ecs);
7332 /* Put the step-breakpoint there and go until there. */
7333 symtab_and_line sr_sal;
7334 sr_sal.pc = ecs->stop_func_start;
7335 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7336 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7338 /* Do not specify what the fp should be when we stop since on
7339 some machines the prologue is where the new fp value is
7341 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7343 /* And make sure stepping stops right away then. */
7344 ecs->event_thread->control.step_range_end
7345 = ecs->event_thread->control.step_range_start;
7350 /* Inferior has stepped backward into a subroutine call with source
7351 code that we should not step over. Do step to the beginning of the
7352 last line of code in it. */
7355 handle_step_into_function_backward (struct gdbarch *gdbarch,
7356 struct execution_control_state *ecs)
7358 struct compunit_symtab *cust;
7359 struct symtab_and_line stop_func_sal;
7361 fill_in_stop_func (gdbarch, ecs);
7363 cust = find_pc_compunit_symtab (stop_pc);
7364 if (cust != NULL && compunit_language (cust) != language_asm)
7365 ecs->stop_func_start
7366 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7368 stop_func_sal = find_pc_line (stop_pc, 0);
7370 /* OK, we're just going to keep stepping here. */
7371 if (stop_func_sal.pc == stop_pc)
7373 /* We're there already. Just stop stepping now. */
7374 end_stepping_range (ecs);
7378 /* Else just reset the step range and keep going.
7379 No step-resume breakpoint, they don't work for
7380 epilogues, which can have multiple entry paths. */
7381 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7382 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7388 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7389 This is used to both functions and to skip over code. */
7392 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7393 struct symtab_and_line sr_sal,
7394 struct frame_id sr_id,
7395 enum bptype sr_type)
7397 /* There should never be more than one step-resume or longjmp-resume
7398 breakpoint per thread, so we should never be setting a new
7399 step_resume_breakpoint when one is already active. */
7400 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7401 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7404 fprintf_unfiltered (gdb_stdlog,
7405 "infrun: inserting step-resume breakpoint at %s\n",
7406 paddress (gdbarch, sr_sal.pc));
7408 inferior_thread ()->control.step_resume_breakpoint
7409 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7413 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7414 struct symtab_and_line sr_sal,
7415 struct frame_id sr_id)
7417 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7422 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7423 This is used to skip a potential signal handler.
7425 This is called with the interrupted function's frame. The signal
7426 handler, when it returns, will resume the interrupted function at
7430 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7432 gdb_assert (return_frame != NULL);
7434 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7436 symtab_and_line sr_sal;
7437 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7438 sr_sal.section = find_pc_overlay (sr_sal.pc);
7439 sr_sal.pspace = get_frame_program_space (return_frame);
7441 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7442 get_stack_frame_id (return_frame),
7446 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7447 is used to skip a function after stepping into it (for "next" or if
7448 the called function has no debugging information).
7450 The current function has almost always been reached by single
7451 stepping a call or return instruction. NEXT_FRAME belongs to the
7452 current function, and the breakpoint will be set at the caller's
7455 This is a separate function rather than reusing
7456 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7457 get_prev_frame, which may stop prematurely (see the implementation
7458 of frame_unwind_caller_id for an example). */
7461 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7463 /* We shouldn't have gotten here if we don't know where the call site
7465 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7467 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7469 symtab_and_line sr_sal;
7470 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7471 frame_unwind_caller_pc (next_frame));
7472 sr_sal.section = find_pc_overlay (sr_sal.pc);
7473 sr_sal.pspace = frame_unwind_program_space (next_frame);
7475 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7476 frame_unwind_caller_id (next_frame));
7479 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7480 new breakpoint at the target of a jmp_buf. The handling of
7481 longjmp-resume uses the same mechanisms used for handling
7482 "step-resume" breakpoints. */
7485 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7487 /* There should never be more than one longjmp-resume breakpoint per
7488 thread, so we should never be setting a new
7489 longjmp_resume_breakpoint when one is already active. */
7490 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7493 fprintf_unfiltered (gdb_stdlog,
7494 "infrun: inserting longjmp-resume breakpoint at %s\n",
7495 paddress (gdbarch, pc));
7497 inferior_thread ()->control.exception_resume_breakpoint =
7498 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7501 /* Insert an exception resume breakpoint. TP is the thread throwing
7502 the exception. The block B is the block of the unwinder debug hook
7503 function. FRAME is the frame corresponding to the call to this
7504 function. SYM is the symbol of the function argument holding the
7505 target PC of the exception. */
7508 insert_exception_resume_breakpoint (struct thread_info *tp,
7509 const struct block *b,
7510 struct frame_info *frame,
7515 struct block_symbol vsym;
7516 struct value *value;
7518 struct breakpoint *bp;
7520 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7521 value = read_var_value (vsym.symbol, vsym.block, frame);
7522 /* If the value was optimized out, revert to the old behavior. */
7523 if (! value_optimized_out (value))
7525 handler = value_as_address (value);
7528 fprintf_unfiltered (gdb_stdlog,
7529 "infrun: exception resume at %lx\n",
7530 (unsigned long) handler);
7532 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7533 handler, bp_exception_resume);
7535 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7538 bp->thread = tp->global_num;
7539 inferior_thread ()->control.exception_resume_breakpoint = bp;
7542 CATCH (e, RETURN_MASK_ERROR)
7544 /* We want to ignore errors here. */
7549 /* A helper for check_exception_resume that sets an
7550 exception-breakpoint based on a SystemTap probe. */
7553 insert_exception_resume_from_probe (struct thread_info *tp,
7554 const struct bound_probe *probe,
7555 struct frame_info *frame)
7557 struct value *arg_value;
7559 struct breakpoint *bp;
7561 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7565 handler = value_as_address (arg_value);
7568 fprintf_unfiltered (gdb_stdlog,
7569 "infrun: exception resume at %s\n",
7570 paddress (get_objfile_arch (probe->objfile),
7573 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7574 handler, bp_exception_resume);
7575 bp->thread = tp->global_num;
7576 inferior_thread ()->control.exception_resume_breakpoint = bp;
7579 /* This is called when an exception has been intercepted. Check to
7580 see whether the exception's destination is of interest, and if so,
7581 set an exception resume breakpoint there. */
7584 check_exception_resume (struct execution_control_state *ecs,
7585 struct frame_info *frame)
7587 struct bound_probe probe;
7588 struct symbol *func;
7590 /* First see if this exception unwinding breakpoint was set via a
7591 SystemTap probe point. If so, the probe has two arguments: the
7592 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7593 set a breakpoint there. */
7594 probe = find_probe_by_pc (get_frame_pc (frame));
7597 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7601 func = get_frame_function (frame);
7607 const struct block *b;
7608 struct block_iterator iter;
7612 /* The exception breakpoint is a thread-specific breakpoint on
7613 the unwinder's debug hook, declared as:
7615 void _Unwind_DebugHook (void *cfa, void *handler);
7617 The CFA argument indicates the frame to which control is
7618 about to be transferred. HANDLER is the destination PC.
7620 We ignore the CFA and set a temporary breakpoint at HANDLER.
7621 This is not extremely efficient but it avoids issues in gdb
7622 with computing the DWARF CFA, and it also works even in weird
7623 cases such as throwing an exception from inside a signal
7626 b = SYMBOL_BLOCK_VALUE (func);
7627 ALL_BLOCK_SYMBOLS (b, iter, sym)
7629 if (!SYMBOL_IS_ARGUMENT (sym))
7636 insert_exception_resume_breakpoint (ecs->event_thread,
7642 CATCH (e, RETURN_MASK_ERROR)
7649 stop_waiting (struct execution_control_state *ecs)
7652 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7654 /* Let callers know we don't want to wait for the inferior anymore. */
7655 ecs->wait_some_more = 0;
7657 /* If all-stop, but the target is always in non-stop mode, stop all
7658 threads now that we're presenting the stop to the user. */
7659 if (!non_stop && target_is_non_stop_p ())
7660 stop_all_threads ();
7663 /* Like keep_going, but passes the signal to the inferior, even if the
7664 signal is set to nopass. */
7667 keep_going_pass_signal (struct execution_control_state *ecs)
7669 /* Make sure normal_stop is called if we get a QUIT handled before
7671 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7673 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7674 gdb_assert (!ecs->event_thread->resumed);
7676 /* Save the pc before execution, to compare with pc after stop. */
7677 ecs->event_thread->prev_pc
7678 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7680 if (ecs->event_thread->control.trap_expected)
7682 struct thread_info *tp = ecs->event_thread;
7685 fprintf_unfiltered (gdb_stdlog,
7686 "infrun: %s has trap_expected set, "
7687 "resuming to collect trap\n",
7688 target_pid_to_str (tp->ptid));
7690 /* We haven't yet gotten our trap, and either: intercepted a
7691 non-signal event (e.g., a fork); or took a signal which we
7692 are supposed to pass through to the inferior. Simply
7694 discard_cleanups (old_cleanups);
7695 resume (ecs->event_thread->suspend.stop_signal);
7697 else if (step_over_info_valid_p ())
7699 /* Another thread is stepping over a breakpoint in-line. If
7700 this thread needs a step-over too, queue the request. In
7701 either case, this resume must be deferred for later. */
7702 struct thread_info *tp = ecs->event_thread;
7704 if (ecs->hit_singlestep_breakpoint
7705 || thread_still_needs_step_over (tp))
7708 fprintf_unfiltered (gdb_stdlog,
7709 "infrun: step-over already in progress: "
7710 "step-over for %s deferred\n",
7711 target_pid_to_str (tp->ptid));
7712 thread_step_over_chain_enqueue (tp);
7717 fprintf_unfiltered (gdb_stdlog,
7718 "infrun: step-over in progress: "
7719 "resume of %s deferred\n",
7720 target_pid_to_str (tp->ptid));
7723 discard_cleanups (old_cleanups);
7727 struct regcache *regcache = get_current_regcache ();
7730 step_over_what step_what;
7732 /* Either the trap was not expected, but we are continuing
7733 anyway (if we got a signal, the user asked it be passed to
7736 We got our expected trap, but decided we should resume from
7739 We're going to run this baby now!
7741 Note that insert_breakpoints won't try to re-insert
7742 already inserted breakpoints. Therefore, we don't
7743 care if breakpoints were already inserted, or not. */
7745 /* If we need to step over a breakpoint, and we're not using
7746 displaced stepping to do so, insert all breakpoints
7747 (watchpoints, etc.) but the one we're stepping over, step one
7748 instruction, and then re-insert the breakpoint when that step
7751 step_what = thread_still_needs_step_over (ecs->event_thread);
7753 remove_bp = (ecs->hit_singlestep_breakpoint
7754 || (step_what & STEP_OVER_BREAKPOINT));
7755 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7757 /* We can't use displaced stepping if we need to step past a
7758 watchpoint. The instruction copied to the scratch pad would
7759 still trigger the watchpoint. */
7761 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7763 set_step_over_info (get_regcache_aspace (regcache),
7764 regcache_read_pc (regcache), remove_wps,
7765 ecs->event_thread->global_num);
7767 else if (remove_wps)
7768 set_step_over_info (NULL, 0, remove_wps, -1);
7770 /* If we now need to do an in-line step-over, we need to stop
7771 all other threads. Note this must be done before
7772 insert_breakpoints below, because that removes the breakpoint
7773 we're about to step over, otherwise other threads could miss
7775 if (step_over_info_valid_p () && target_is_non_stop_p ())
7776 stop_all_threads ();
7778 /* Stop stepping if inserting breakpoints fails. */
7781 insert_breakpoints ();
7783 CATCH (e, RETURN_MASK_ERROR)
7785 exception_print (gdb_stderr, e);
7787 discard_cleanups (old_cleanups);
7792 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7794 discard_cleanups (old_cleanups);
7795 resume (ecs->event_thread->suspend.stop_signal);
7798 prepare_to_wait (ecs);
7801 /* Called when we should continue running the inferior, because the
7802 current event doesn't cause a user visible stop. This does the
7803 resuming part; waiting for the next event is done elsewhere. */
7806 keep_going (struct execution_control_state *ecs)
7808 if (ecs->event_thread->control.trap_expected
7809 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7810 ecs->event_thread->control.trap_expected = 0;
7812 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7813 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7814 keep_going_pass_signal (ecs);
7817 /* This function normally comes after a resume, before
7818 handle_inferior_event exits. It takes care of any last bits of
7819 housekeeping, and sets the all-important wait_some_more flag. */
7822 prepare_to_wait (struct execution_control_state *ecs)
7825 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7827 ecs->wait_some_more = 1;
7829 if (!target_is_async_p ())
7830 mark_infrun_async_event_handler ();
7833 /* We are done with the step range of a step/next/si/ni command.
7834 Called once for each n of a "step n" operation. */
7837 end_stepping_range (struct execution_control_state *ecs)
7839 ecs->event_thread->control.stop_step = 1;
7843 /* Several print_*_reason functions to print why the inferior has stopped.
7844 We always print something when the inferior exits, or receives a signal.
7845 The rest of the cases are dealt with later on in normal_stop and
7846 print_it_typical. Ideally there should be a call to one of these
7847 print_*_reason functions functions from handle_inferior_event each time
7848 stop_waiting is called.
7850 Note that we don't call these directly, instead we delegate that to
7851 the interpreters, through observers. Interpreters then call these
7852 with whatever uiout is right. */
7855 print_end_stepping_range_reason (struct ui_out *uiout)
7857 /* For CLI-like interpreters, print nothing. */
7859 if (uiout->is_mi_like_p ())
7861 uiout->field_string ("reason",
7862 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7867 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7869 annotate_signalled ();
7870 if (uiout->is_mi_like_p ())
7872 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7873 uiout->text ("\nProgram terminated with signal ");
7874 annotate_signal_name ();
7875 uiout->field_string ("signal-name",
7876 gdb_signal_to_name (siggnal));
7877 annotate_signal_name_end ();
7879 annotate_signal_string ();
7880 uiout->field_string ("signal-meaning",
7881 gdb_signal_to_string (siggnal));
7882 annotate_signal_string_end ();
7883 uiout->text (".\n");
7884 uiout->text ("The program no longer exists.\n");
7888 print_exited_reason (struct ui_out *uiout, int exitstatus)
7890 struct inferior *inf = current_inferior ();
7891 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7893 annotate_exited (exitstatus);
7896 if (uiout->is_mi_like_p ())
7897 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7898 uiout->text ("[Inferior ");
7899 uiout->text (plongest (inf->num));
7901 uiout->text (pidstr);
7902 uiout->text (") exited with code ");
7903 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7904 uiout->text ("]\n");
7908 if (uiout->is_mi_like_p ())
7910 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7911 uiout->text ("[Inferior ");
7912 uiout->text (plongest (inf->num));
7914 uiout->text (pidstr);
7915 uiout->text (") exited normally]\n");
7919 /* Some targets/architectures can do extra processing/display of
7920 segmentation faults. E.g., Intel MPX boundary faults.
7921 Call the architecture dependent function to handle the fault. */
7924 handle_segmentation_fault (struct ui_out *uiout)
7926 struct regcache *regcache = get_current_regcache ();
7927 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7929 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7930 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7934 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7936 struct thread_info *thr = inferior_thread ();
7940 if (uiout->is_mi_like_p ())
7942 else if (show_thread_that_caused_stop ())
7946 uiout->text ("\nThread ");
7947 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7949 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7952 uiout->text (" \"");
7953 uiout->field_fmt ("name", "%s", name);
7958 uiout->text ("\nProgram");
7960 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7961 uiout->text (" stopped");
7964 uiout->text (" received signal ");
7965 annotate_signal_name ();
7966 if (uiout->is_mi_like_p ())
7968 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7969 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7970 annotate_signal_name_end ();
7972 annotate_signal_string ();
7973 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7975 if (siggnal == GDB_SIGNAL_SEGV)
7976 handle_segmentation_fault (uiout);
7978 annotate_signal_string_end ();
7980 uiout->text (".\n");
7984 print_no_history_reason (struct ui_out *uiout)
7986 uiout->text ("\nNo more reverse-execution history.\n");
7989 /* Print current location without a level number, if we have changed
7990 functions or hit a breakpoint. Print source line if we have one.
7991 bpstat_print contains the logic deciding in detail what to print,
7992 based on the event(s) that just occurred. */
7995 print_stop_location (struct target_waitstatus *ws)
7998 enum print_what source_flag;
7999 int do_frame_printing = 1;
8000 struct thread_info *tp = inferior_thread ();
8002 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
8006 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8007 should) carry around the function and does (or should) use
8008 that when doing a frame comparison. */
8009 if (tp->control.stop_step
8010 && frame_id_eq (tp->control.step_frame_id,
8011 get_frame_id (get_current_frame ()))
8012 && tp->control.step_start_function == find_pc_function (stop_pc))
8014 /* Finished step, just print source line. */
8015 source_flag = SRC_LINE;
8019 /* Print location and source line. */
8020 source_flag = SRC_AND_LOC;
8023 case PRINT_SRC_AND_LOC:
8024 /* Print location and source line. */
8025 source_flag = SRC_AND_LOC;
8027 case PRINT_SRC_ONLY:
8028 source_flag = SRC_LINE;
8031 /* Something bogus. */
8032 source_flag = SRC_LINE;
8033 do_frame_printing = 0;
8036 internal_error (__FILE__, __LINE__, _("Unknown value."));
8039 /* The behavior of this routine with respect to the source
8041 SRC_LINE: Print only source line
8042 LOCATION: Print only location
8043 SRC_AND_LOC: Print location and source line. */
8044 if (do_frame_printing)
8045 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8051 print_stop_event (struct ui_out *uiout)
8053 struct target_waitstatus last;
8055 struct thread_info *tp;
8057 get_last_target_status (&last_ptid, &last);
8060 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8062 print_stop_location (&last);
8064 /* Display the auto-display expressions. */
8068 tp = inferior_thread ();
8069 if (tp->thread_fsm != NULL
8070 && thread_fsm_finished_p (tp->thread_fsm))
8072 struct return_value_info *rv;
8074 rv = thread_fsm_return_value (tp->thread_fsm);
8076 print_return_value (uiout, rv);
8083 maybe_remove_breakpoints (void)
8085 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8087 if (remove_breakpoints ())
8089 target_terminal::ours_for_output ();
8090 printf_filtered (_("Cannot remove breakpoints because "
8091 "program is no longer writable.\nFurther "
8092 "execution is probably impossible.\n"));
8097 /* The execution context that just caused a normal stop. */
8104 /* The event PTID. */
8108 /* If stopp for a thread event, this is the thread that caused the
8110 struct thread_info *thread;
8112 /* The inferior that caused the stop. */
8116 /* Returns a new stop context. If stopped for a thread event, this
8117 takes a strong reference to the thread. */
8119 static struct stop_context *
8120 save_stop_context (void)
8122 struct stop_context *sc = XNEW (struct stop_context);
8124 sc->stop_id = get_stop_id ();
8125 sc->ptid = inferior_ptid;
8126 sc->inf_num = current_inferior ()->num;
8128 if (!ptid_equal (inferior_ptid, null_ptid))
8130 /* Take a strong reference so that the thread can't be deleted
8132 sc->thread = inferior_thread ();
8133 sc->thread->incref ();
8141 /* Release a stop context previously created with save_stop_context.
8142 Releases the strong reference to the thread as well. */
8145 release_stop_context_cleanup (void *arg)
8147 struct stop_context *sc = (struct stop_context *) arg;
8149 if (sc->thread != NULL)
8150 sc->thread->decref ();
8154 /* Return true if the current context no longer matches the saved stop
8158 stop_context_changed (struct stop_context *prev)
8160 if (!ptid_equal (prev->ptid, inferior_ptid))
8162 if (prev->inf_num != current_inferior ()->num)
8164 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8166 if (get_stop_id () != prev->stop_id)
8176 struct target_waitstatus last;
8178 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
8181 get_last_target_status (&last_ptid, &last);
8185 /* If an exception is thrown from this point on, make sure to
8186 propagate GDB's knowledge of the executing state to the
8187 frontend/user running state. A QUIT is an easy exception to see
8188 here, so do this before any filtered output. */
8190 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
8191 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8192 || last.kind == TARGET_WAITKIND_EXITED)
8194 /* On some targets, we may still have live threads in the
8195 inferior when we get a process exit event. E.g., for
8196 "checkpoint", when the current checkpoint/fork exits,
8197 linux-fork.c automatically switches to another fork from
8198 within target_mourn_inferior. */
8199 if (!ptid_equal (inferior_ptid, null_ptid))
8201 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
8202 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
8205 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8206 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
8208 /* As we're presenting a stop, and potentially removing breakpoints,
8209 update the thread list so we can tell whether there are threads
8210 running on the target. With target remote, for example, we can
8211 only learn about new threads when we explicitly update the thread
8212 list. Do this before notifying the interpreters about signal
8213 stops, end of stepping ranges, etc., so that the "new thread"
8214 output is emitted before e.g., "Program received signal FOO",
8215 instead of after. */
8216 update_thread_list ();
8218 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8219 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
8221 /* As with the notification of thread events, we want to delay
8222 notifying the user that we've switched thread context until
8223 the inferior actually stops.
8225 There's no point in saying anything if the inferior has exited.
8226 Note that SIGNALLED here means "exited with a signal", not
8227 "received a signal".
8229 Also skip saying anything in non-stop mode. In that mode, as we
8230 don't want GDB to switch threads behind the user's back, to avoid
8231 races where the user is typing a command to apply to thread x,
8232 but GDB switches to thread y before the user finishes entering
8233 the command, fetch_inferior_event installs a cleanup to restore
8234 the current thread back to the thread the user had selected right
8235 after this event is handled, so we're not really switching, only
8236 informing of a stop. */
8238 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8239 && target_has_execution
8240 && last.kind != TARGET_WAITKIND_SIGNALLED
8241 && last.kind != TARGET_WAITKIND_EXITED
8242 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8244 SWITCH_THRU_ALL_UIS ()
8246 target_terminal::ours_for_output ();
8247 printf_filtered (_("[Switching to %s]\n"),
8248 target_pid_to_str (inferior_ptid));
8249 annotate_thread_changed ();
8251 previous_inferior_ptid = inferior_ptid;
8254 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8256 SWITCH_THRU_ALL_UIS ()
8257 if (current_ui->prompt_state == PROMPT_BLOCKED)
8259 target_terminal::ours_for_output ();
8260 printf_filtered (_("No unwaited-for children left.\n"));
8264 /* Note: this depends on the update_thread_list call above. */
8265 maybe_remove_breakpoints ();
8267 /* If an auto-display called a function and that got a signal,
8268 delete that auto-display to avoid an infinite recursion. */
8270 if (stopped_by_random_signal)
8271 disable_current_display ();
8273 SWITCH_THRU_ALL_UIS ()
8275 async_enable_stdin ();
8278 /* Let the user/frontend see the threads as stopped. */
8279 do_cleanups (old_chain);
8281 /* Select innermost stack frame - i.e., current frame is frame 0,
8282 and current location is based on that. Handle the case where the
8283 dummy call is returning after being stopped. E.g. the dummy call
8284 previously hit a breakpoint. (If the dummy call returns
8285 normally, we won't reach here.) Do this before the stop hook is
8286 run, so that it doesn't get to see the temporary dummy frame,
8287 which is not where we'll present the stop. */
8288 if (has_stack_frames ())
8290 if (stop_stack_dummy == STOP_STACK_DUMMY)
8292 /* Pop the empty frame that contains the stack dummy. This
8293 also restores inferior state prior to the call (struct
8294 infcall_suspend_state). */
8295 struct frame_info *frame = get_current_frame ();
8297 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8299 /* frame_pop calls reinit_frame_cache as the last thing it
8300 does which means there's now no selected frame. */
8303 select_frame (get_current_frame ());
8305 /* Set the current source location. */
8306 set_current_sal_from_frame (get_current_frame ());
8309 /* Look up the hook_stop and run it (CLI internally handles problem
8310 of stop_command's pre-hook not existing). */
8311 if (stop_command != NULL)
8313 struct stop_context *saved_context = save_stop_context ();
8314 struct cleanup *old_chain
8315 = make_cleanup (release_stop_context_cleanup, saved_context);
8317 catch_errors (hook_stop_stub, stop_command,
8318 "Error while running hook_stop:\n", RETURN_MASK_ALL);
8320 /* If the stop hook resumes the target, then there's no point in
8321 trying to notify about the previous stop; its context is
8322 gone. Likewise if the command switches thread or inferior --
8323 the observers would print a stop for the wrong
8325 if (stop_context_changed (saved_context))
8327 do_cleanups (old_chain);
8330 do_cleanups (old_chain);
8333 /* Notify observers about the stop. This is where the interpreters
8334 print the stop event. */
8335 if (!ptid_equal (inferior_ptid, null_ptid))
8336 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8339 observer_notify_normal_stop (NULL, stop_print_frame);
8341 annotate_stopped ();
8343 if (target_has_execution)
8345 if (last.kind != TARGET_WAITKIND_SIGNALLED
8346 && last.kind != TARGET_WAITKIND_EXITED)
8347 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8348 Delete any breakpoint that is to be deleted at the next stop. */
8349 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8352 /* Try to get rid of automatically added inferiors that are no
8353 longer needed. Keeping those around slows down things linearly.
8354 Note that this never removes the current inferior. */
8361 hook_stop_stub (void *cmd)
8363 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
8368 signal_stop_state (int signo)
8370 return signal_stop[signo];
8374 signal_print_state (int signo)
8376 return signal_print[signo];
8380 signal_pass_state (int signo)
8382 return signal_program[signo];
8386 signal_cache_update (int signo)
8390 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8391 signal_cache_update (signo);
8396 signal_pass[signo] = (signal_stop[signo] == 0
8397 && signal_print[signo] == 0
8398 && signal_program[signo] == 1
8399 && signal_catch[signo] == 0);
8403 signal_stop_update (int signo, int state)
8405 int ret = signal_stop[signo];
8407 signal_stop[signo] = state;
8408 signal_cache_update (signo);
8413 signal_print_update (int signo, int state)
8415 int ret = signal_print[signo];
8417 signal_print[signo] = state;
8418 signal_cache_update (signo);
8423 signal_pass_update (int signo, int state)
8425 int ret = signal_program[signo];
8427 signal_program[signo] = state;
8428 signal_cache_update (signo);
8432 /* Update the global 'signal_catch' from INFO and notify the
8436 signal_catch_update (const unsigned int *info)
8440 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8441 signal_catch[i] = info[i] > 0;
8442 signal_cache_update (-1);
8443 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8447 sig_print_header (void)
8449 printf_filtered (_("Signal Stop\tPrint\tPass "
8450 "to program\tDescription\n"));
8454 sig_print_info (enum gdb_signal oursig)
8456 const char *name = gdb_signal_to_name (oursig);
8457 int name_padding = 13 - strlen (name);
8459 if (name_padding <= 0)
8462 printf_filtered ("%s", name);
8463 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8464 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8465 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8466 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8467 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8470 /* Specify how various signals in the inferior should be handled. */
8473 handle_command (char *args, int from_tty)
8475 int digits, wordlen;
8476 int sigfirst, signum, siglast;
8477 enum gdb_signal oursig;
8480 unsigned char *sigs;
8484 error_no_arg (_("signal to handle"));
8487 /* Allocate and zero an array of flags for which signals to handle. */
8489 nsigs = (int) GDB_SIGNAL_LAST;
8490 sigs = (unsigned char *) alloca (nsigs);
8491 memset (sigs, 0, nsigs);
8493 /* Break the command line up into args. */
8495 gdb_argv built_argv (args);
8497 /* Walk through the args, looking for signal oursigs, signal names, and
8498 actions. Signal numbers and signal names may be interspersed with
8499 actions, with the actions being performed for all signals cumulatively
8500 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8502 for (char *arg : built_argv)
8504 wordlen = strlen (arg);
8505 for (digits = 0; isdigit (arg[digits]); digits++)
8509 sigfirst = siglast = -1;
8511 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8513 /* Apply action to all signals except those used by the
8514 debugger. Silently skip those. */
8517 siglast = nsigs - 1;
8519 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8521 SET_SIGS (nsigs, sigs, signal_stop);
8522 SET_SIGS (nsigs, sigs, signal_print);
8524 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8526 UNSET_SIGS (nsigs, sigs, signal_program);
8528 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8530 SET_SIGS (nsigs, sigs, signal_print);
8532 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8534 SET_SIGS (nsigs, sigs, signal_program);
8536 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8538 UNSET_SIGS (nsigs, sigs, signal_stop);
8540 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8542 SET_SIGS (nsigs, sigs, signal_program);
8544 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8546 UNSET_SIGS (nsigs, sigs, signal_print);
8547 UNSET_SIGS (nsigs, sigs, signal_stop);
8549 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8551 UNSET_SIGS (nsigs, sigs, signal_program);
8553 else if (digits > 0)
8555 /* It is numeric. The numeric signal refers to our own
8556 internal signal numbering from target.h, not to host/target
8557 signal number. This is a feature; users really should be
8558 using symbolic names anyway, and the common ones like
8559 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8561 sigfirst = siglast = (int)
8562 gdb_signal_from_command (atoi (arg));
8563 if (arg[digits] == '-')
8566 gdb_signal_from_command (atoi (arg + digits + 1));
8568 if (sigfirst > siglast)
8570 /* Bet he didn't figure we'd think of this case... */
8578 oursig = gdb_signal_from_name (arg);
8579 if (oursig != GDB_SIGNAL_UNKNOWN)
8581 sigfirst = siglast = (int) oursig;
8585 /* Not a number and not a recognized flag word => complain. */
8586 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8590 /* If any signal numbers or symbol names were found, set flags for
8591 which signals to apply actions to. */
8593 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8595 switch ((enum gdb_signal) signum)
8597 case GDB_SIGNAL_TRAP:
8598 case GDB_SIGNAL_INT:
8599 if (!allsigs && !sigs[signum])
8601 if (query (_("%s is used by the debugger.\n\
8602 Are you sure you want to change it? "),
8603 gdb_signal_to_name ((enum gdb_signal) signum)))
8609 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8610 gdb_flush (gdb_stdout);
8615 case GDB_SIGNAL_DEFAULT:
8616 case GDB_SIGNAL_UNKNOWN:
8617 /* Make sure that "all" doesn't print these. */
8626 for (signum = 0; signum < nsigs; signum++)
8629 signal_cache_update (-1);
8630 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8631 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8635 /* Show the results. */
8636 sig_print_header ();
8637 for (; signum < nsigs; signum++)
8639 sig_print_info ((enum gdb_signal) signum);
8646 /* Complete the "handle" command. */
8649 handle_completer (struct cmd_list_element *ignore,
8650 completion_tracker &tracker,
8651 const char *text, const char *word)
8653 static const char * const keywords[] =
8667 signal_completer (ignore, tracker, text, word);
8668 complete_on_enum (tracker, keywords, word, word);
8672 gdb_signal_from_command (int num)
8674 if (num >= 1 && num <= 15)
8675 return (enum gdb_signal) num;
8676 error (_("Only signals 1-15 are valid as numeric signals.\n\
8677 Use \"info signals\" for a list of symbolic signals."));
8680 /* Print current contents of the tables set by the handle command.
8681 It is possible we should just be printing signals actually used
8682 by the current target (but for things to work right when switching
8683 targets, all signals should be in the signal tables). */
8686 info_signals_command (char *signum_exp, int from_tty)
8688 enum gdb_signal oursig;
8690 sig_print_header ();
8694 /* First see if this is a symbol name. */
8695 oursig = gdb_signal_from_name (signum_exp);
8696 if (oursig == GDB_SIGNAL_UNKNOWN)
8698 /* No, try numeric. */
8700 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8702 sig_print_info (oursig);
8706 printf_filtered ("\n");
8707 /* These ugly casts brought to you by the native VAX compiler. */
8708 for (oursig = GDB_SIGNAL_FIRST;
8709 (int) oursig < (int) GDB_SIGNAL_LAST;
8710 oursig = (enum gdb_signal) ((int) oursig + 1))
8714 if (oursig != GDB_SIGNAL_UNKNOWN
8715 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8716 sig_print_info (oursig);
8719 printf_filtered (_("\nUse the \"handle\" command "
8720 "to change these tables.\n"));
8723 /* The $_siginfo convenience variable is a bit special. We don't know
8724 for sure the type of the value until we actually have a chance to
8725 fetch the data. The type can change depending on gdbarch, so it is
8726 also dependent on which thread you have selected.
8728 1. making $_siginfo be an internalvar that creates a new value on
8731 2. making the value of $_siginfo be an lval_computed value. */
8733 /* This function implements the lval_computed support for reading a
8737 siginfo_value_read (struct value *v)
8739 LONGEST transferred;
8741 /* If we can access registers, so can we access $_siginfo. Likewise
8743 validate_registers_access ();
8746 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8748 value_contents_all_raw (v),
8750 TYPE_LENGTH (value_type (v)));
8752 if (transferred != TYPE_LENGTH (value_type (v)))
8753 error (_("Unable to read siginfo"));
8756 /* This function implements the lval_computed support for writing a
8760 siginfo_value_write (struct value *v, struct value *fromval)
8762 LONGEST transferred;
8764 /* If we can access registers, so can we access $_siginfo. Likewise
8766 validate_registers_access ();
8768 transferred = target_write (¤t_target,
8769 TARGET_OBJECT_SIGNAL_INFO,
8771 value_contents_all_raw (fromval),
8773 TYPE_LENGTH (value_type (fromval)));
8775 if (transferred != TYPE_LENGTH (value_type (fromval)))
8776 error (_("Unable to write siginfo"));
8779 static const struct lval_funcs siginfo_value_funcs =
8785 /* Return a new value with the correct type for the siginfo object of
8786 the current thread using architecture GDBARCH. Return a void value
8787 if there's no object available. */
8789 static struct value *
8790 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8793 if (target_has_stack
8794 && !ptid_equal (inferior_ptid, null_ptid)
8795 && gdbarch_get_siginfo_type_p (gdbarch))
8797 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8799 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8802 return allocate_value (builtin_type (gdbarch)->builtin_void);
8806 /* infcall_suspend_state contains state about the program itself like its
8807 registers and any signal it received when it last stopped.
8808 This state must be restored regardless of how the inferior function call
8809 ends (either successfully, or after it hits a breakpoint or signal)
8810 if the program is to properly continue where it left off. */
8812 struct infcall_suspend_state
8814 struct thread_suspend_state thread_suspend;
8818 struct regcache *registers;
8820 /* Format of SIGINFO_DATA or NULL if it is not present. */
8821 struct gdbarch *siginfo_gdbarch;
8823 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8824 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8825 content would be invalid. */
8826 gdb_byte *siginfo_data;
8829 struct infcall_suspend_state *
8830 save_infcall_suspend_state (void)
8832 struct infcall_suspend_state *inf_state;
8833 struct thread_info *tp = inferior_thread ();
8834 struct regcache *regcache = get_current_regcache ();
8835 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8836 gdb_byte *siginfo_data = NULL;
8838 if (gdbarch_get_siginfo_type_p (gdbarch))
8840 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8841 size_t len = TYPE_LENGTH (type);
8842 struct cleanup *back_to;
8844 siginfo_data = (gdb_byte *) xmalloc (len);
8845 back_to = make_cleanup (xfree, siginfo_data);
8847 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8848 siginfo_data, 0, len) == len)
8849 discard_cleanups (back_to);
8852 /* Errors ignored. */
8853 do_cleanups (back_to);
8854 siginfo_data = NULL;
8858 inf_state = XCNEW (struct infcall_suspend_state);
8862 inf_state->siginfo_gdbarch = gdbarch;
8863 inf_state->siginfo_data = siginfo_data;
8866 inf_state->thread_suspend = tp->suspend;
8868 /* run_inferior_call will not use the signal due to its `proceed' call with
8869 GDB_SIGNAL_0 anyway. */
8870 tp->suspend.stop_signal = GDB_SIGNAL_0;
8872 inf_state->stop_pc = stop_pc;
8874 inf_state->registers = regcache_dup (regcache);
8879 /* Restore inferior session state to INF_STATE. */
8882 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8884 struct thread_info *tp = inferior_thread ();
8885 struct regcache *regcache = get_current_regcache ();
8886 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8888 tp->suspend = inf_state->thread_suspend;
8890 stop_pc = inf_state->stop_pc;
8892 if (inf_state->siginfo_gdbarch == gdbarch)
8894 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8896 /* Errors ignored. */
8897 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8898 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8901 /* The inferior can be gone if the user types "print exit(0)"
8902 (and perhaps other times). */
8903 if (target_has_execution)
8904 /* NB: The register write goes through to the target. */
8905 regcache_cpy (regcache, inf_state->registers);
8907 discard_infcall_suspend_state (inf_state);
8911 do_restore_infcall_suspend_state_cleanup (void *state)
8913 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8917 make_cleanup_restore_infcall_suspend_state
8918 (struct infcall_suspend_state *inf_state)
8920 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8924 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8926 delete inf_state->registers;
8927 xfree (inf_state->siginfo_data);
8932 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8934 return inf_state->registers;
8937 /* infcall_control_state contains state regarding gdb's control of the
8938 inferior itself like stepping control. It also contains session state like
8939 the user's currently selected frame. */
8941 struct infcall_control_state
8943 struct thread_control_state thread_control;
8944 struct inferior_control_state inferior_control;
8947 enum stop_stack_kind stop_stack_dummy;
8948 int stopped_by_random_signal;
8950 /* ID if the selected frame when the inferior function call was made. */
8951 struct frame_id selected_frame_id;
8954 /* Save all of the information associated with the inferior<==>gdb
8957 struct infcall_control_state *
8958 save_infcall_control_state (void)
8960 struct infcall_control_state *inf_status =
8961 XNEW (struct infcall_control_state);
8962 struct thread_info *tp = inferior_thread ();
8963 struct inferior *inf = current_inferior ();
8965 inf_status->thread_control = tp->control;
8966 inf_status->inferior_control = inf->control;
8968 tp->control.step_resume_breakpoint = NULL;
8969 tp->control.exception_resume_breakpoint = NULL;
8971 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8972 chain. If caller's caller is walking the chain, they'll be happier if we
8973 hand them back the original chain when restore_infcall_control_state is
8975 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8978 inf_status->stop_stack_dummy = stop_stack_dummy;
8979 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8981 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8987 restore_selected_frame (void *args)
8989 struct frame_id *fid = (struct frame_id *) args;
8990 struct frame_info *frame;
8992 frame = frame_find_by_id (*fid);
8994 /* If inf_status->selected_frame_id is NULL, there was no previously
8998 warning (_("Unable to restore previously selected frame."));
9002 select_frame (frame);
9007 /* Restore inferior session state to INF_STATUS. */
9010 restore_infcall_control_state (struct infcall_control_state *inf_status)
9012 struct thread_info *tp = inferior_thread ();
9013 struct inferior *inf = current_inferior ();
9015 if (tp->control.step_resume_breakpoint)
9016 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
9018 if (tp->control.exception_resume_breakpoint)
9019 tp->control.exception_resume_breakpoint->disposition
9020 = disp_del_at_next_stop;
9022 /* Handle the bpstat_copy of the chain. */
9023 bpstat_clear (&tp->control.stop_bpstat);
9025 tp->control = inf_status->thread_control;
9026 inf->control = inf_status->inferior_control;
9029 stop_stack_dummy = inf_status->stop_stack_dummy;
9030 stopped_by_random_signal = inf_status->stopped_by_random_signal;
9032 if (target_has_stack)
9034 /* The point of catch_errors is that if the stack is clobbered,
9035 walking the stack might encounter a garbage pointer and
9036 error() trying to dereference it. */
9038 (restore_selected_frame, &inf_status->selected_frame_id,
9039 "Unable to restore previously selected frame:\n",
9040 RETURN_MASK_ERROR) == 0)
9041 /* Error in restoring the selected frame. Select the innermost
9043 select_frame (get_current_frame ());
9050 do_restore_infcall_control_state_cleanup (void *sts)
9052 restore_infcall_control_state ((struct infcall_control_state *) sts);
9056 make_cleanup_restore_infcall_control_state
9057 (struct infcall_control_state *inf_status)
9059 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9063 discard_infcall_control_state (struct infcall_control_state *inf_status)
9065 if (inf_status->thread_control.step_resume_breakpoint)
9066 inf_status->thread_control.step_resume_breakpoint->disposition
9067 = disp_del_at_next_stop;
9069 if (inf_status->thread_control.exception_resume_breakpoint)
9070 inf_status->thread_control.exception_resume_breakpoint->disposition
9071 = disp_del_at_next_stop;
9073 /* See save_infcall_control_state for info on stop_bpstat. */
9074 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9082 clear_exit_convenience_vars (void)
9084 clear_internalvar (lookup_internalvar ("_exitsignal"));
9085 clear_internalvar (lookup_internalvar ("_exitcode"));
9089 /* User interface for reverse debugging:
9090 Set exec-direction / show exec-direction commands
9091 (returns error unless target implements to_set_exec_direction method). */
9093 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9094 static const char exec_forward[] = "forward";
9095 static const char exec_reverse[] = "reverse";
9096 static const char *exec_direction = exec_forward;
9097 static const char *const exec_direction_names[] = {
9104 set_exec_direction_func (char *args, int from_tty,
9105 struct cmd_list_element *cmd)
9107 if (target_can_execute_reverse)
9109 if (!strcmp (exec_direction, exec_forward))
9110 execution_direction = EXEC_FORWARD;
9111 else if (!strcmp (exec_direction, exec_reverse))
9112 execution_direction = EXEC_REVERSE;
9116 exec_direction = exec_forward;
9117 error (_("Target does not support this operation."));
9122 show_exec_direction_func (struct ui_file *out, int from_tty,
9123 struct cmd_list_element *cmd, const char *value)
9125 switch (execution_direction) {
9127 fprintf_filtered (out, _("Forward.\n"));
9130 fprintf_filtered (out, _("Reverse.\n"));
9133 internal_error (__FILE__, __LINE__,
9134 _("bogus execution_direction value: %d"),
9135 (int) execution_direction);
9140 show_schedule_multiple (struct ui_file *file, int from_tty,
9141 struct cmd_list_element *c, const char *value)
9143 fprintf_filtered (file, _("Resuming the execution of threads "
9144 "of all processes is %s.\n"), value);
9147 /* Implementation of `siginfo' variable. */
9149 static const struct internalvar_funcs siginfo_funcs =
9156 /* Callback for infrun's target events source. This is marked when a
9157 thread has a pending status to process. */
9160 infrun_async_inferior_event_handler (gdb_client_data data)
9162 inferior_event_handler (INF_REG_EVENT, NULL);
9166 _initialize_infrun (void)
9170 struct cmd_list_element *c;
9172 /* Register extra event sources in the event loop. */
9173 infrun_async_inferior_event_token
9174 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9176 add_info ("signals", info_signals_command, _("\
9177 What debugger does when program gets various signals.\n\
9178 Specify a signal as argument to print info on that signal only."));
9179 add_info_alias ("handle", "signals", 0);
9181 c = add_com ("handle", class_run, handle_command, _("\
9182 Specify how to handle signals.\n\
9183 Usage: handle SIGNAL [ACTIONS]\n\
9184 Args are signals and actions to apply to those signals.\n\
9185 If no actions are specified, the current settings for the specified signals\n\
9186 will be displayed instead.\n\
9188 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9189 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9190 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9191 The special arg \"all\" is recognized to mean all signals except those\n\
9192 used by the debugger, typically SIGTRAP and SIGINT.\n\
9194 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9195 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9196 Stop means reenter debugger if this signal happens (implies print).\n\
9197 Print means print a message if this signal happens.\n\
9198 Pass means let program see this signal; otherwise program doesn't know.\n\
9199 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9200 Pass and Stop may be combined.\n\
9202 Multiple signals may be specified. Signal numbers and signal names\n\
9203 may be interspersed with actions, with the actions being performed for\n\
9204 all signals cumulatively specified."));
9205 set_cmd_completer (c, handle_completer);
9208 stop_command = add_cmd ("stop", class_obscure,
9209 not_just_help_class_command, _("\
9210 There is no `stop' command, but you can set a hook on `stop'.\n\
9211 This allows you to set a list of commands to be run each time execution\n\
9212 of the program stops."), &cmdlist);
9214 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9215 Set inferior debugging."), _("\
9216 Show inferior debugging."), _("\
9217 When non-zero, inferior specific debugging is enabled."),
9220 &setdebuglist, &showdebuglist);
9222 add_setshow_boolean_cmd ("displaced", class_maintenance,
9223 &debug_displaced, _("\
9224 Set displaced stepping debugging."), _("\
9225 Show displaced stepping debugging."), _("\
9226 When non-zero, displaced stepping specific debugging is enabled."),
9228 show_debug_displaced,
9229 &setdebuglist, &showdebuglist);
9231 add_setshow_boolean_cmd ("non-stop", no_class,
9233 Set whether gdb controls the inferior in non-stop mode."), _("\
9234 Show whether gdb controls the inferior in non-stop mode."), _("\
9235 When debugging a multi-threaded program and this setting is\n\
9236 off (the default, also called all-stop mode), when one thread stops\n\
9237 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9238 all other threads in the program while you interact with the thread of\n\
9239 interest. When you continue or step a thread, you can allow the other\n\
9240 threads to run, or have them remain stopped, but while you inspect any\n\
9241 thread's state, all threads stop.\n\
9243 In non-stop mode, when one thread stops, other threads can continue\n\
9244 to run freely. You'll be able to step each thread independently,\n\
9245 leave it stopped or free to run as needed."),
9251 numsigs = (int) GDB_SIGNAL_LAST;
9252 signal_stop = XNEWVEC (unsigned char, numsigs);
9253 signal_print = XNEWVEC (unsigned char, numsigs);
9254 signal_program = XNEWVEC (unsigned char, numsigs);
9255 signal_catch = XNEWVEC (unsigned char, numsigs);
9256 signal_pass = XNEWVEC (unsigned char, numsigs);
9257 for (i = 0; i < numsigs; i++)
9260 signal_print[i] = 1;
9261 signal_program[i] = 1;
9262 signal_catch[i] = 0;
9265 /* Signals caused by debugger's own actions should not be given to
9266 the program afterwards.
9268 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9269 explicitly specifies that it should be delivered to the target
9270 program. Typically, that would occur when a user is debugging a
9271 target monitor on a simulator: the target monitor sets a
9272 breakpoint; the simulator encounters this breakpoint and halts
9273 the simulation handing control to GDB; GDB, noting that the stop
9274 address doesn't map to any known breakpoint, returns control back
9275 to the simulator; the simulator then delivers the hardware
9276 equivalent of a GDB_SIGNAL_TRAP to the program being
9278 signal_program[GDB_SIGNAL_TRAP] = 0;
9279 signal_program[GDB_SIGNAL_INT] = 0;
9281 /* Signals that are not errors should not normally enter the debugger. */
9282 signal_stop[GDB_SIGNAL_ALRM] = 0;
9283 signal_print[GDB_SIGNAL_ALRM] = 0;
9284 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9285 signal_print[GDB_SIGNAL_VTALRM] = 0;
9286 signal_stop[GDB_SIGNAL_PROF] = 0;
9287 signal_print[GDB_SIGNAL_PROF] = 0;
9288 signal_stop[GDB_SIGNAL_CHLD] = 0;
9289 signal_print[GDB_SIGNAL_CHLD] = 0;
9290 signal_stop[GDB_SIGNAL_IO] = 0;
9291 signal_print[GDB_SIGNAL_IO] = 0;
9292 signal_stop[GDB_SIGNAL_POLL] = 0;
9293 signal_print[GDB_SIGNAL_POLL] = 0;
9294 signal_stop[GDB_SIGNAL_URG] = 0;
9295 signal_print[GDB_SIGNAL_URG] = 0;
9296 signal_stop[GDB_SIGNAL_WINCH] = 0;
9297 signal_print[GDB_SIGNAL_WINCH] = 0;
9298 signal_stop[GDB_SIGNAL_PRIO] = 0;
9299 signal_print[GDB_SIGNAL_PRIO] = 0;
9301 /* These signals are used internally by user-level thread
9302 implementations. (See signal(5) on Solaris.) Like the above
9303 signals, a healthy program receives and handles them as part of
9304 its normal operation. */
9305 signal_stop[GDB_SIGNAL_LWP] = 0;
9306 signal_print[GDB_SIGNAL_LWP] = 0;
9307 signal_stop[GDB_SIGNAL_WAITING] = 0;
9308 signal_print[GDB_SIGNAL_WAITING] = 0;
9309 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9310 signal_print[GDB_SIGNAL_CANCEL] = 0;
9311 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9312 signal_print[GDB_SIGNAL_LIBRT] = 0;
9314 /* Update cached state. */
9315 signal_cache_update (-1);
9317 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9318 &stop_on_solib_events, _("\
9319 Set stopping for shared library events."), _("\
9320 Show stopping for shared library events."), _("\
9321 If nonzero, gdb will give control to the user when the dynamic linker\n\
9322 notifies gdb of shared library events. The most common event of interest\n\
9323 to the user would be loading/unloading of a new library."),
9324 set_stop_on_solib_events,
9325 show_stop_on_solib_events,
9326 &setlist, &showlist);
9328 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9329 follow_fork_mode_kind_names,
9330 &follow_fork_mode_string, _("\
9331 Set debugger response to a program call of fork or vfork."), _("\
9332 Show debugger response to a program call of fork or vfork."), _("\
9333 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9334 parent - the original process is debugged after a fork\n\
9335 child - the new process is debugged after a fork\n\
9336 The unfollowed process will continue to run.\n\
9337 By default, the debugger will follow the parent process."),
9339 show_follow_fork_mode_string,
9340 &setlist, &showlist);
9342 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9343 follow_exec_mode_names,
9344 &follow_exec_mode_string, _("\
9345 Set debugger response to a program call of exec."), _("\
9346 Show debugger response to a program call of exec."), _("\
9347 An exec call replaces the program image of a process.\n\
9349 follow-exec-mode can be:\n\
9351 new - the debugger creates a new inferior and rebinds the process\n\
9352 to this new inferior. The program the process was running before\n\
9353 the exec call can be restarted afterwards by restarting the original\n\
9356 same - the debugger keeps the process bound to the same inferior.\n\
9357 The new executable image replaces the previous executable loaded in\n\
9358 the inferior. Restarting the inferior after the exec call restarts\n\
9359 the executable the process was running after the exec call.\n\
9361 By default, the debugger will use the same inferior."),
9363 show_follow_exec_mode_string,
9364 &setlist, &showlist);
9366 add_setshow_enum_cmd ("scheduler-locking", class_run,
9367 scheduler_enums, &scheduler_mode, _("\
9368 Set mode for locking scheduler during execution."), _("\
9369 Show mode for locking scheduler during execution."), _("\
9370 off == no locking (threads may preempt at any time)\n\
9371 on == full locking (no thread except the current thread may run)\n\
9372 This applies to both normal execution and replay mode.\n\
9373 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9374 In this mode, other threads may run during other commands.\n\
9375 This applies to both normal execution and replay mode.\n\
9376 replay == scheduler locked in replay mode and unlocked during normal execution."),
9377 set_schedlock_func, /* traps on target vector */
9378 show_scheduler_mode,
9379 &setlist, &showlist);
9381 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9382 Set mode for resuming threads of all processes."), _("\
9383 Show mode for resuming threads of all processes."), _("\
9384 When on, execution commands (such as 'continue' or 'next') resume all\n\
9385 threads of all processes. When off (which is the default), execution\n\
9386 commands only resume the threads of the current process. The set of\n\
9387 threads that are resumed is further refined by the scheduler-locking\n\
9388 mode (see help set scheduler-locking)."),
9390 show_schedule_multiple,
9391 &setlist, &showlist);
9393 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9394 Set mode of the step operation."), _("\
9395 Show mode of the step operation."), _("\
9396 When set, doing a step over a function without debug line information\n\
9397 will stop at the first instruction of that function. Otherwise, the\n\
9398 function is skipped and the step command stops at a different source line."),
9400 show_step_stop_if_no_debug,
9401 &setlist, &showlist);
9403 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9404 &can_use_displaced_stepping, _("\
9405 Set debugger's willingness to use displaced stepping."), _("\
9406 Show debugger's willingness to use displaced stepping."), _("\
9407 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9408 supported by the target architecture. If off, gdb will not use displaced\n\
9409 stepping to step over breakpoints, even if such is supported by the target\n\
9410 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9411 if the target architecture supports it and non-stop mode is active, but will not\n\
9412 use it in all-stop mode (see help set non-stop)."),
9414 show_can_use_displaced_stepping,
9415 &setlist, &showlist);
9417 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9418 &exec_direction, _("Set direction of execution.\n\
9419 Options are 'forward' or 'reverse'."),
9420 _("Show direction of execution (forward/reverse)."),
9421 _("Tells gdb whether to execute forward or backward."),
9422 set_exec_direction_func, show_exec_direction_func,
9423 &setlist, &showlist);
9425 /* Set/show detach-on-fork: user-settable mode. */
9427 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9428 Set whether gdb will detach the child of a fork."), _("\
9429 Show whether gdb will detach the child of a fork."), _("\
9430 Tells gdb whether to detach the child of a fork."),
9431 NULL, NULL, &setlist, &showlist);
9433 /* Set/show disable address space randomization mode. */
9435 add_setshow_boolean_cmd ("disable-randomization", class_support,
9436 &disable_randomization, _("\
9437 Set disabling of debuggee's virtual address space randomization."), _("\
9438 Show disabling of debuggee's virtual address space randomization."), _("\
9439 When this mode is on (which is the default), randomization of the virtual\n\
9440 address space is disabled. Standalone programs run with the randomization\n\
9441 enabled by default on some platforms."),
9442 &set_disable_randomization,
9443 &show_disable_randomization,
9444 &setlist, &showlist);
9446 /* ptid initializations */
9447 inferior_ptid = null_ptid;
9448 target_last_wait_ptid = minus_one_ptid;
9450 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9451 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9452 observer_attach_thread_exit (infrun_thread_thread_exit);
9453 observer_attach_inferior_exit (infrun_inferior_exit);
9455 /* Explicitly create without lookup, since that tries to create a
9456 value with a void typed value, and when we get here, gdbarch
9457 isn't initialized yet. At this point, we're quite sure there
9458 isn't another convenience variable of the same name. */
9459 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9461 add_setshow_boolean_cmd ("observer", no_class,
9462 &observer_mode_1, _("\
9463 Set whether gdb controls the inferior in observer mode."), _("\
9464 Show whether gdb controls the inferior in observer mode."), _("\
9465 In observer mode, GDB can get data from the inferior, but not\n\
9466 affect its execution. Registers and memory may not be changed,\n\
9467 breakpoints may not be set, and the program cannot be interrupted\n\