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 sig_print_info (enum gdb_signal);
77 static void sig_print_header (void);
79 static void resume_cleanups (void *);
81 static int follow_fork (void);
83 static int follow_fork_inferior (int follow_child, int detach_fork);
85 static void follow_inferior_reset_breakpoints (void);
87 static void set_schedlock_func (char *args, int from_tty,
88 struct cmd_list_element *c);
90 static int currently_stepping (struct thread_info *tp);
92 void nullify_last_target_wait_ptid (void);
94 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
96 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
98 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
100 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
102 /* Asynchronous signal handler registered as event loop source for
103 when we have pending events ready to be passed to the core. */
104 static struct async_event_handler *infrun_async_inferior_event_token;
106 /* Stores whether infrun_async was previously enabled or disabled.
107 Starts off as -1, indicating "never enabled/disabled". */
108 static int infrun_is_async = -1;
113 infrun_async (int enable)
115 if (infrun_is_async != enable)
117 infrun_is_async = enable;
120 fprintf_unfiltered (gdb_stdlog,
121 "infrun: infrun_async(%d)\n",
125 mark_async_event_handler (infrun_async_inferior_event_token);
127 clear_async_event_handler (infrun_async_inferior_event_token);
134 mark_infrun_async_event_handler (void)
136 mark_async_event_handler (infrun_async_inferior_event_token);
139 /* When set, stop the 'step' command if we enter a function which has
140 no line number information. The normal behavior is that we step
141 over such function. */
142 int step_stop_if_no_debug = 0;
144 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
145 struct cmd_list_element *c, const char *value)
147 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
150 /* proceed and normal_stop use this to notify the user when the
151 inferior stopped in a different thread than it had been running
154 static ptid_t previous_inferior_ptid;
156 /* If set (default for legacy reasons), when following a fork, GDB
157 will detach from one of the fork branches, child or parent.
158 Exactly which branch is detached depends on 'set follow-fork-mode'
161 static int detach_fork = 1;
163 int debug_displaced = 0;
165 show_debug_displaced (struct ui_file *file, int from_tty,
166 struct cmd_list_element *c, const char *value)
168 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
171 unsigned int debug_infrun = 0;
173 show_debug_infrun (struct ui_file *file, int from_tty,
174 struct cmd_list_element *c, const char *value)
176 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
180 /* Support for disabling address space randomization. */
182 int disable_randomization = 1;
185 show_disable_randomization (struct ui_file *file, int from_tty,
186 struct cmd_list_element *c, const char *value)
188 if (target_supports_disable_randomization ())
189 fprintf_filtered (file,
190 _("Disabling randomization of debuggee's "
191 "virtual address space is %s.\n"),
194 fputs_filtered (_("Disabling randomization of debuggee's "
195 "virtual address space is unsupported on\n"
196 "this platform.\n"), file);
200 set_disable_randomization (char *args, int from_tty,
201 struct cmd_list_element *c)
203 if (!target_supports_disable_randomization ())
204 error (_("Disabling randomization of debuggee's "
205 "virtual address space is unsupported on\n"
209 /* User interface for non-stop mode. */
212 static int non_stop_1 = 0;
215 set_non_stop (char *args, int from_tty,
216 struct cmd_list_element *c)
218 if (target_has_execution)
220 non_stop_1 = non_stop;
221 error (_("Cannot change this setting while the inferior is running."));
224 non_stop = non_stop_1;
228 show_non_stop (struct ui_file *file, int from_tty,
229 struct cmd_list_element *c, const char *value)
231 fprintf_filtered (file,
232 _("Controlling the inferior in non-stop mode is %s.\n"),
236 /* "Observer mode" is somewhat like a more extreme version of
237 non-stop, in which all GDB operations that might affect the
238 target's execution have been disabled. */
240 int observer_mode = 0;
241 static int observer_mode_1 = 0;
244 set_observer_mode (char *args, int from_tty,
245 struct cmd_list_element *c)
247 if (target_has_execution)
249 observer_mode_1 = observer_mode;
250 error (_("Cannot change this setting while the inferior is running."));
253 observer_mode = observer_mode_1;
255 may_write_registers = !observer_mode;
256 may_write_memory = !observer_mode;
257 may_insert_breakpoints = !observer_mode;
258 may_insert_tracepoints = !observer_mode;
259 /* We can insert fast tracepoints in or out of observer mode,
260 but enable them if we're going into this mode. */
262 may_insert_fast_tracepoints = 1;
263 may_stop = !observer_mode;
264 update_target_permissions ();
266 /* Going *into* observer mode we must force non-stop, then
267 going out we leave it that way. */
270 pagination_enabled = 0;
271 non_stop = non_stop_1 = 1;
275 printf_filtered (_("Observer mode is now %s.\n"),
276 (observer_mode ? "on" : "off"));
280 show_observer_mode (struct ui_file *file, int from_tty,
281 struct cmd_list_element *c, const char *value)
283 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
286 /* This updates the value of observer mode based on changes in
287 permissions. Note that we are deliberately ignoring the values of
288 may-write-registers and may-write-memory, since the user may have
289 reason to enable these during a session, for instance to turn on a
290 debugging-related global. */
293 update_observer_mode (void)
297 newval = (!may_insert_breakpoints
298 && !may_insert_tracepoints
299 && may_insert_fast_tracepoints
303 /* Let the user know if things change. */
304 if (newval != observer_mode)
305 printf_filtered (_("Observer mode is now %s.\n"),
306 (newval ? "on" : "off"));
308 observer_mode = observer_mode_1 = newval;
311 /* Tables of how to react to signals; the user sets them. */
313 static unsigned char *signal_stop;
314 static unsigned char *signal_print;
315 static unsigned char *signal_program;
317 /* Table of signals that are registered with "catch signal". A
318 non-zero entry indicates that the signal is caught by some "catch
319 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
321 static unsigned char *signal_catch;
323 /* Table of signals that the target may silently handle.
324 This is automatically determined from the flags above,
325 and simply cached here. */
326 static unsigned char *signal_pass;
328 #define SET_SIGS(nsigs,sigs,flags) \
330 int signum = (nsigs); \
331 while (signum-- > 0) \
332 if ((sigs)[signum]) \
333 (flags)[signum] = 1; \
336 #define UNSET_SIGS(nsigs,sigs,flags) \
338 int signum = (nsigs); \
339 while (signum-- > 0) \
340 if ((sigs)[signum]) \
341 (flags)[signum] = 0; \
344 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
345 this function is to avoid exporting `signal_program'. */
348 update_signals_program_target (void)
350 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
353 /* Value to pass to target_resume() to cause all threads to resume. */
355 #define RESUME_ALL minus_one_ptid
357 /* Command list pointer for the "stop" placeholder. */
359 static struct cmd_list_element *stop_command;
361 /* Nonzero if we want to give control to the user when we're notified
362 of shared library events by the dynamic linker. */
363 int stop_on_solib_events;
365 /* Enable or disable optional shared library event breakpoints
366 as appropriate when the above flag is changed. */
369 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
371 update_solib_breakpoints ();
375 show_stop_on_solib_events (struct ui_file *file, int from_tty,
376 struct cmd_list_element *c, const char *value)
378 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
382 /* Nonzero after stop if current stack frame should be printed. */
384 static int stop_print_frame;
386 /* This is a cached copy of the pid/waitstatus of the last event
387 returned by target_wait()/deprecated_target_wait_hook(). This
388 information is returned by get_last_target_status(). */
389 static ptid_t target_last_wait_ptid;
390 static struct target_waitstatus target_last_waitstatus;
392 static void context_switch (ptid_t ptid);
394 void init_thread_stepping_state (struct thread_info *tss);
396 static const char follow_fork_mode_child[] = "child";
397 static const char follow_fork_mode_parent[] = "parent";
399 static const char *const follow_fork_mode_kind_names[] = {
400 follow_fork_mode_child,
401 follow_fork_mode_parent,
405 static const char *follow_fork_mode_string = follow_fork_mode_parent;
407 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
408 struct cmd_list_element *c, const char *value)
410 fprintf_filtered (file,
411 _("Debugger response to a program "
412 "call of fork or vfork is \"%s\".\n"),
417 /* Handle changes to the inferior list based on the type of fork,
418 which process is being followed, and whether the other process
419 should be detached. On entry inferior_ptid must be the ptid of
420 the fork parent. At return inferior_ptid is the ptid of the
421 followed inferior. */
424 follow_fork_inferior (int follow_child, int detach_fork)
427 ptid_t parent_ptid, child_ptid;
429 has_vforked = (inferior_thread ()->pending_follow.kind
430 == TARGET_WAITKIND_VFORKED);
431 parent_ptid = inferior_ptid;
432 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
435 && !non_stop /* Non-stop always resumes both branches. */
436 && current_ui->prompt_state == PROMPT_BLOCKED
437 && !(follow_child || detach_fork || sched_multi))
439 /* The parent stays blocked inside the vfork syscall until the
440 child execs or exits. If we don't let the child run, then
441 the parent stays blocked. If we're telling the parent to run
442 in the foreground, the user will not be able to ctrl-c to get
443 back the terminal, effectively hanging the debug session. */
444 fprintf_filtered (gdb_stderr, _("\
445 Can not resume the parent process over vfork in the foreground while\n\
446 holding the child stopped. Try \"set detach-on-fork\" or \
447 \"set schedule-multiple\".\n"));
448 /* FIXME output string > 80 columns. */
454 /* Detach new forked process? */
457 /* Before detaching from the child, remove all breakpoints
458 from it. If we forked, then this has already been taken
459 care of by infrun.c. If we vforked however, any
460 breakpoint inserted in the parent is visible in the
461 child, even those added while stopped in a vfork
462 catchpoint. This will remove the breakpoints from the
463 parent also, but they'll be reinserted below. */
466 /* Keep breakpoints list in sync. */
467 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
470 if (info_verbose || debug_infrun)
472 /* Ensure that we have a process ptid. */
473 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
475 target_terminal::ours_for_output ();
476 fprintf_filtered (gdb_stdlog,
477 _("Detaching after %s from child %s.\n"),
478 has_vforked ? "vfork" : "fork",
479 target_pid_to_str (process_ptid));
484 struct inferior *parent_inf, *child_inf;
486 /* Add process to GDB's tables. */
487 child_inf = add_inferior (ptid_get_pid (child_ptid));
489 parent_inf = current_inferior ();
490 child_inf->attach_flag = parent_inf->attach_flag;
491 copy_terminal_info (child_inf, parent_inf);
492 child_inf->gdbarch = parent_inf->gdbarch;
493 copy_inferior_target_desc_info (child_inf, parent_inf);
495 scoped_restore_current_pspace_and_thread restore_pspace_thread;
497 inferior_ptid = child_ptid;
498 add_thread (inferior_ptid);
499 set_current_inferior (child_inf);
500 child_inf->symfile_flags = SYMFILE_NO_READ;
502 /* If this is a vfork child, then the address-space is
503 shared with the parent. */
506 child_inf->pspace = parent_inf->pspace;
507 child_inf->aspace = parent_inf->aspace;
509 /* The parent will be frozen until the child is done
510 with the shared region. Keep track of the
512 child_inf->vfork_parent = parent_inf;
513 child_inf->pending_detach = 0;
514 parent_inf->vfork_child = child_inf;
515 parent_inf->pending_detach = 0;
519 child_inf->aspace = new_address_space ();
520 child_inf->pspace = add_program_space (child_inf->aspace);
521 child_inf->removable = 1;
522 set_current_program_space (child_inf->pspace);
523 clone_program_space (child_inf->pspace, parent_inf->pspace);
525 /* Let the shared library layer (e.g., solib-svr4) learn
526 about this new process, relocate the cloned exec, pull
527 in shared libraries, and install the solib event
528 breakpoint. If a "cloned-VM" event was propagated
529 better throughout the core, this wouldn't be
531 solib_create_inferior_hook (0);
537 struct inferior *parent_inf;
539 parent_inf = current_inferior ();
541 /* If we detached from the child, then we have to be careful
542 to not insert breakpoints in the parent until the child
543 is done with the shared memory region. However, if we're
544 staying attached to the child, then we can and should
545 insert breakpoints, so that we can debug it. A
546 subsequent child exec or exit is enough to know when does
547 the child stops using the parent's address space. */
548 parent_inf->waiting_for_vfork_done = detach_fork;
549 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
554 /* Follow the child. */
555 struct inferior *parent_inf, *child_inf;
556 struct program_space *parent_pspace;
558 if (info_verbose || debug_infrun)
560 target_terminal::ours_for_output ();
561 fprintf_filtered (gdb_stdlog,
562 _("Attaching after %s %s to child %s.\n"),
563 target_pid_to_str (parent_ptid),
564 has_vforked ? "vfork" : "fork",
565 target_pid_to_str (child_ptid));
568 /* Add the new inferior first, so that the target_detach below
569 doesn't unpush the target. */
571 child_inf = add_inferior (ptid_get_pid (child_ptid));
573 parent_inf = current_inferior ();
574 child_inf->attach_flag = parent_inf->attach_flag;
575 copy_terminal_info (child_inf, parent_inf);
576 child_inf->gdbarch = parent_inf->gdbarch;
577 copy_inferior_target_desc_info (child_inf, parent_inf);
579 parent_pspace = parent_inf->pspace;
581 /* If we're vforking, we want to hold on to the parent until the
582 child exits or execs. At child exec or exit time we can
583 remove the old breakpoints from the parent and detach or
584 resume debugging it. Otherwise, detach the parent now; we'll
585 want to reuse it's program/address spaces, but we can't set
586 them to the child before removing breakpoints from the
587 parent, otherwise, the breakpoints module could decide to
588 remove breakpoints from the wrong process (since they'd be
589 assigned to the same address space). */
593 gdb_assert (child_inf->vfork_parent == NULL);
594 gdb_assert (parent_inf->vfork_child == NULL);
595 child_inf->vfork_parent = parent_inf;
596 child_inf->pending_detach = 0;
597 parent_inf->vfork_child = child_inf;
598 parent_inf->pending_detach = detach_fork;
599 parent_inf->waiting_for_vfork_done = 0;
601 else if (detach_fork)
603 if (info_verbose || debug_infrun)
605 /* Ensure that we have a process ptid. */
606 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
608 target_terminal::ours_for_output ();
609 fprintf_filtered (gdb_stdlog,
610 _("Detaching after fork from "
612 target_pid_to_str (process_ptid));
615 target_detach (NULL, 0);
618 /* Note that the detach above makes PARENT_INF dangling. */
620 /* Add the child thread to the appropriate lists, and switch to
621 this new thread, before cloning the program space, and
622 informing the solib layer about this new process. */
624 inferior_ptid = child_ptid;
625 add_thread (inferior_ptid);
626 set_current_inferior (child_inf);
628 /* If this is a vfork child, then the address-space is shared
629 with the parent. If we detached from the parent, then we can
630 reuse the parent's program/address spaces. */
631 if (has_vforked || detach_fork)
633 child_inf->pspace = parent_pspace;
634 child_inf->aspace = child_inf->pspace->aspace;
638 child_inf->aspace = new_address_space ();
639 child_inf->pspace = add_program_space (child_inf->aspace);
640 child_inf->removable = 1;
641 child_inf->symfile_flags = SYMFILE_NO_READ;
642 set_current_program_space (child_inf->pspace);
643 clone_program_space (child_inf->pspace, parent_pspace);
645 /* Let the shared library layer (e.g., solib-svr4) learn
646 about this new process, relocate the cloned exec, pull in
647 shared libraries, and install the solib event breakpoint.
648 If a "cloned-VM" event was propagated better throughout
649 the core, this wouldn't be required. */
650 solib_create_inferior_hook (0);
654 return target_follow_fork (follow_child, detach_fork);
657 /* Tell the target to follow the fork we're stopped at. Returns true
658 if the inferior should be resumed; false, if the target for some
659 reason decided it's best not to resume. */
664 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
665 int should_resume = 1;
666 struct thread_info *tp;
668 /* Copy user stepping state to the new inferior thread. FIXME: the
669 followed fork child thread should have a copy of most of the
670 parent thread structure's run control related fields, not just these.
671 Initialized to avoid "may be used uninitialized" warnings from gcc. */
672 struct breakpoint *step_resume_breakpoint = NULL;
673 struct breakpoint *exception_resume_breakpoint = NULL;
674 CORE_ADDR step_range_start = 0;
675 CORE_ADDR step_range_end = 0;
676 struct frame_id step_frame_id = { 0 };
677 struct thread_fsm *thread_fsm = NULL;
682 struct target_waitstatus wait_status;
684 /* Get the last target status returned by target_wait(). */
685 get_last_target_status (&wait_ptid, &wait_status);
687 /* If not stopped at a fork event, then there's nothing else to
689 if (wait_status.kind != TARGET_WAITKIND_FORKED
690 && wait_status.kind != TARGET_WAITKIND_VFORKED)
693 /* Check if we switched over from WAIT_PTID, since the event was
695 if (!ptid_equal (wait_ptid, minus_one_ptid)
696 && !ptid_equal (inferior_ptid, wait_ptid))
698 /* We did. Switch back to WAIT_PTID thread, to tell the
699 target to follow it (in either direction). We'll
700 afterwards refuse to resume, and inform the user what
702 switch_to_thread (wait_ptid);
707 tp = inferior_thread ();
709 /* If there were any forks/vforks that were caught and are now to be
710 followed, then do so now. */
711 switch (tp->pending_follow.kind)
713 case TARGET_WAITKIND_FORKED:
714 case TARGET_WAITKIND_VFORKED:
716 ptid_t parent, child;
718 /* If the user did a next/step, etc, over a fork call,
719 preserve the stepping state in the fork child. */
720 if (follow_child && should_resume)
722 step_resume_breakpoint = clone_momentary_breakpoint
723 (tp->control.step_resume_breakpoint);
724 step_range_start = tp->control.step_range_start;
725 step_range_end = tp->control.step_range_end;
726 step_frame_id = tp->control.step_frame_id;
727 exception_resume_breakpoint
728 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
729 thread_fsm = tp->thread_fsm;
731 /* For now, delete the parent's sr breakpoint, otherwise,
732 parent/child sr breakpoints are considered duplicates,
733 and the child version will not be installed. Remove
734 this when the breakpoints module becomes aware of
735 inferiors and address spaces. */
736 delete_step_resume_breakpoint (tp);
737 tp->control.step_range_start = 0;
738 tp->control.step_range_end = 0;
739 tp->control.step_frame_id = null_frame_id;
740 delete_exception_resume_breakpoint (tp);
741 tp->thread_fsm = NULL;
744 parent = inferior_ptid;
745 child = tp->pending_follow.value.related_pid;
747 /* Set up inferior(s) as specified by the caller, and tell the
748 target to do whatever is necessary to follow either parent
750 if (follow_fork_inferior (follow_child, detach_fork))
752 /* Target refused to follow, or there's some other reason
753 we shouldn't resume. */
758 /* This pending follow fork event is now handled, one way
759 or another. The previous selected thread may be gone
760 from the lists by now, but if it is still around, need
761 to clear the pending follow request. */
762 tp = find_thread_ptid (parent);
764 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
766 /* This makes sure we don't try to apply the "Switched
767 over from WAIT_PID" logic above. */
768 nullify_last_target_wait_ptid ();
770 /* If we followed the child, switch to it... */
773 switch_to_thread (child);
775 /* ... and preserve the stepping state, in case the
776 user was stepping over the fork call. */
779 tp = inferior_thread ();
780 tp->control.step_resume_breakpoint
781 = step_resume_breakpoint;
782 tp->control.step_range_start = step_range_start;
783 tp->control.step_range_end = step_range_end;
784 tp->control.step_frame_id = step_frame_id;
785 tp->control.exception_resume_breakpoint
786 = exception_resume_breakpoint;
787 tp->thread_fsm = thread_fsm;
791 /* If we get here, it was because we're trying to
792 resume from a fork catchpoint, but, the user
793 has switched threads away from the thread that
794 forked. In that case, the resume command
795 issued is most likely not applicable to the
796 child, so just warn, and refuse to resume. */
797 warning (_("Not resuming: switched threads "
798 "before following fork child."));
801 /* Reset breakpoints in the child as appropriate. */
802 follow_inferior_reset_breakpoints ();
805 switch_to_thread (parent);
809 case TARGET_WAITKIND_SPURIOUS:
810 /* Nothing to follow. */
813 internal_error (__FILE__, __LINE__,
814 "Unexpected pending_follow.kind %d\n",
815 tp->pending_follow.kind);
819 return should_resume;
823 follow_inferior_reset_breakpoints (void)
825 struct thread_info *tp = inferior_thread ();
827 /* Was there a step_resume breakpoint? (There was if the user
828 did a "next" at the fork() call.) If so, explicitly reset its
829 thread number. Cloned step_resume breakpoints are disabled on
830 creation, so enable it here now that it is associated with the
833 step_resumes are a form of bp that are made to be per-thread.
834 Since we created the step_resume bp when the parent process
835 was being debugged, and now are switching to the child process,
836 from the breakpoint package's viewpoint, that's a switch of
837 "threads". We must update the bp's notion of which thread
838 it is for, or it'll be ignored when it triggers. */
840 if (tp->control.step_resume_breakpoint)
842 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
843 tp->control.step_resume_breakpoint->loc->enabled = 1;
846 /* Treat exception_resume breakpoints like step_resume breakpoints. */
847 if (tp->control.exception_resume_breakpoint)
849 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
850 tp->control.exception_resume_breakpoint->loc->enabled = 1;
853 /* Reinsert all breakpoints in the child. The user may have set
854 breakpoints after catching the fork, in which case those
855 were never set in the child, but only in the parent. This makes
856 sure the inserted breakpoints match the breakpoint list. */
858 breakpoint_re_set ();
859 insert_breakpoints ();
862 /* The child has exited or execed: resume threads of the parent the
863 user wanted to be executing. */
866 proceed_after_vfork_done (struct thread_info *thread,
869 int pid = * (int *) arg;
871 if (ptid_get_pid (thread->ptid) == pid
872 && is_running (thread->ptid)
873 && !is_executing (thread->ptid)
874 && !thread->stop_requested
875 && thread->suspend.stop_signal == GDB_SIGNAL_0)
878 fprintf_unfiltered (gdb_stdlog,
879 "infrun: resuming vfork parent thread %s\n",
880 target_pid_to_str (thread->ptid));
882 switch_to_thread (thread->ptid);
883 clear_proceed_status (0);
884 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
890 /* Save/restore inferior_ptid, current program space and current
891 inferior. Only use this if the current context points at an exited
892 inferior (and therefore there's no current thread to save). */
893 class scoped_restore_exited_inferior
896 scoped_restore_exited_inferior ()
897 : m_saved_ptid (&inferior_ptid)
901 scoped_restore_tmpl<ptid_t> m_saved_ptid;
902 scoped_restore_current_program_space m_pspace;
903 scoped_restore_current_inferior m_inferior;
906 /* Called whenever we notice an exec or exit event, to handle
907 detaching or resuming a vfork parent. */
910 handle_vfork_child_exec_or_exit (int exec)
912 struct inferior *inf = current_inferior ();
914 if (inf->vfork_parent)
916 int resume_parent = -1;
918 /* This exec or exit marks the end of the shared memory region
919 between the parent and the child. If the user wanted to
920 detach from the parent, now is the time. */
922 if (inf->vfork_parent->pending_detach)
924 struct thread_info *tp;
925 struct program_space *pspace;
926 struct address_space *aspace;
928 /* follow-fork child, detach-on-fork on. */
930 inf->vfork_parent->pending_detach = 0;
932 gdb::optional<scoped_restore_exited_inferior>
933 maybe_restore_inferior;
934 gdb::optional<scoped_restore_current_pspace_and_thread>
935 maybe_restore_thread;
937 /* If we're handling a child exit, then inferior_ptid points
938 at the inferior's pid, not to a thread. */
940 maybe_restore_inferior.emplace ();
942 maybe_restore_thread.emplace ();
944 /* We're letting loose of the parent. */
945 tp = any_live_thread_of_process (inf->vfork_parent->pid);
946 switch_to_thread (tp->ptid);
948 /* We're about to detach from the parent, which implicitly
949 removes breakpoints from its address space. There's a
950 catch here: we want to reuse the spaces for the child,
951 but, parent/child are still sharing the pspace at this
952 point, although the exec in reality makes the kernel give
953 the child a fresh set of new pages. The problem here is
954 that the breakpoints module being unaware of this, would
955 likely chose the child process to write to the parent
956 address space. Swapping the child temporarily away from
957 the spaces has the desired effect. Yes, this is "sort
960 pspace = inf->pspace;
961 aspace = inf->aspace;
965 if (debug_infrun || info_verbose)
967 target_terminal::ours_for_output ();
971 fprintf_filtered (gdb_stdlog,
972 _("Detaching vfork parent process "
973 "%d after child exec.\n"),
974 inf->vfork_parent->pid);
978 fprintf_filtered (gdb_stdlog,
979 _("Detaching vfork parent process "
980 "%d after child exit.\n"),
981 inf->vfork_parent->pid);
985 target_detach (NULL, 0);
988 inf->pspace = pspace;
989 inf->aspace = aspace;
993 /* We're staying attached to the parent, so, really give the
994 child a new address space. */
995 inf->pspace = add_program_space (maybe_new_address_space ());
996 inf->aspace = inf->pspace->aspace;
998 set_current_program_space (inf->pspace);
1000 resume_parent = inf->vfork_parent->pid;
1002 /* Break the bonds. */
1003 inf->vfork_parent->vfork_child = NULL;
1007 struct program_space *pspace;
1009 /* If this is a vfork child exiting, then the pspace and
1010 aspaces were shared with the parent. Since we're
1011 reporting the process exit, we'll be mourning all that is
1012 found in the address space, and switching to null_ptid,
1013 preparing to start a new inferior. But, since we don't
1014 want to clobber the parent's address/program spaces, we
1015 go ahead and create a new one for this exiting
1018 /* Switch to null_ptid while running clone_program_space, so
1019 that clone_program_space doesn't want to read the
1020 selected frame of a dead process. */
1021 scoped_restore restore_ptid
1022 = make_scoped_restore (&inferior_ptid, null_ptid);
1024 /* This inferior is dead, so avoid giving the breakpoints
1025 module the option to write through to it (cloning a
1026 program space resets breakpoints). */
1029 pspace = add_program_space (maybe_new_address_space ());
1030 set_current_program_space (pspace);
1032 inf->symfile_flags = SYMFILE_NO_READ;
1033 clone_program_space (pspace, inf->vfork_parent->pspace);
1034 inf->pspace = pspace;
1035 inf->aspace = pspace->aspace;
1037 resume_parent = inf->vfork_parent->pid;
1038 /* Break the bonds. */
1039 inf->vfork_parent->vfork_child = NULL;
1042 inf->vfork_parent = NULL;
1044 gdb_assert (current_program_space == inf->pspace);
1046 if (non_stop && resume_parent != -1)
1048 /* If the user wanted the parent to be running, let it go
1050 scoped_restore_current_thread restore_thread;
1053 fprintf_unfiltered (gdb_stdlog,
1054 "infrun: resuming vfork parent process %d\n",
1057 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1062 /* Enum strings for "set|show follow-exec-mode". */
1064 static const char follow_exec_mode_new[] = "new";
1065 static const char follow_exec_mode_same[] = "same";
1066 static const char *const follow_exec_mode_names[] =
1068 follow_exec_mode_new,
1069 follow_exec_mode_same,
1073 static const char *follow_exec_mode_string = follow_exec_mode_same;
1075 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1076 struct cmd_list_element *c, const char *value)
1078 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1081 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1084 follow_exec (ptid_t ptid, char *exec_file_target)
1086 struct thread_info *th, *tmp;
1087 struct inferior *inf = current_inferior ();
1088 int pid = ptid_get_pid (ptid);
1089 ptid_t process_ptid;
1090 char *exec_file_host;
1091 struct cleanup *old_chain;
1093 /* This is an exec event that we actually wish to pay attention to.
1094 Refresh our symbol table to the newly exec'd program, remove any
1095 momentary bp's, etc.
1097 If there are breakpoints, they aren't really inserted now,
1098 since the exec() transformed our inferior into a fresh set
1101 We want to preserve symbolic breakpoints on the list, since
1102 we have hopes that they can be reset after the new a.out's
1103 symbol table is read.
1105 However, any "raw" breakpoints must be removed from the list
1106 (e.g., the solib bp's), since their address is probably invalid
1109 And, we DON'T want to call delete_breakpoints() here, since
1110 that may write the bp's "shadow contents" (the instruction
1111 value that was overwritten witha TRAP instruction). Since
1112 we now have a new a.out, those shadow contents aren't valid. */
1114 mark_breakpoints_out ();
1116 /* The target reports the exec event to the main thread, even if
1117 some other thread does the exec, and even if the main thread was
1118 stopped or already gone. We may still have non-leader threads of
1119 the process on our list. E.g., on targets that don't have thread
1120 exit events (like remote); or on native Linux in non-stop mode if
1121 there were only two threads in the inferior and the non-leader
1122 one is the one that execs (and nothing forces an update of the
1123 thread list up to here). When debugging remotely, it's best to
1124 avoid extra traffic, when possible, so avoid syncing the thread
1125 list with the target, and instead go ahead and delete all threads
1126 of the process but one that reported the event. Note this must
1127 be done before calling update_breakpoints_after_exec, as
1128 otherwise clearing the threads' resources would reference stale
1129 thread breakpoints -- it may have been one of these threads that
1130 stepped across the exec. We could just clear their stepping
1131 states, but as long as we're iterating, might as well delete
1132 them. Deleting them now rather than at the next user-visible
1133 stop provides a nicer sequence of events for user and MI
1135 ALL_THREADS_SAFE (th, tmp)
1136 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1137 delete_thread (th->ptid);
1139 /* We also need to clear any left over stale state for the
1140 leader/event thread. E.g., if there was any step-resume
1141 breakpoint or similar, it's gone now. We cannot truly
1142 step-to-next statement through an exec(). */
1143 th = inferior_thread ();
1144 th->control.step_resume_breakpoint = NULL;
1145 th->control.exception_resume_breakpoint = NULL;
1146 th->control.single_step_breakpoints = NULL;
1147 th->control.step_range_start = 0;
1148 th->control.step_range_end = 0;
1150 /* The user may have had the main thread held stopped in the
1151 previous image (e.g., schedlock on, or non-stop). Release
1153 th->stop_requested = 0;
1155 update_breakpoints_after_exec ();
1157 /* What is this a.out's name? */
1158 process_ptid = pid_to_ptid (pid);
1159 printf_unfiltered (_("%s is executing new program: %s\n"),
1160 target_pid_to_str (process_ptid),
1163 /* We've followed the inferior through an exec. Therefore, the
1164 inferior has essentially been killed & reborn. */
1166 gdb_flush (gdb_stdout);
1168 breakpoint_init_inferior (inf_execd);
1170 exec_file_host = exec_file_find (exec_file_target, NULL);
1171 old_chain = make_cleanup (xfree, exec_file_host);
1173 /* If we were unable to map the executable target pathname onto a host
1174 pathname, tell the user that. Otherwise GDB's subsequent behavior
1175 is confusing. Maybe it would even be better to stop at this point
1176 so that the user can specify a file manually before continuing. */
1177 if (exec_file_host == NULL)
1178 warning (_("Could not load symbols for executable %s.\n"
1179 "Do you need \"set sysroot\"?"),
1182 /* Reset the shared library package. This ensures that we get a
1183 shlib event when the child reaches "_start", at which point the
1184 dld will have had a chance to initialize the child. */
1185 /* Also, loading a symbol file below may trigger symbol lookups, and
1186 we don't want those to be satisfied by the libraries of the
1187 previous incarnation of this process. */
1188 no_shared_libraries (NULL, 0);
1190 if (follow_exec_mode_string == follow_exec_mode_new)
1192 /* The user wants to keep the old inferior and program spaces
1193 around. Create a new fresh one, and switch to it. */
1195 /* Do exit processing for the original inferior before adding
1196 the new inferior so we don't have two active inferiors with
1197 the same ptid, which can confuse find_inferior_ptid. */
1198 exit_inferior_num_silent (current_inferior ()->num);
1200 inf = add_inferior_with_spaces ();
1202 target_follow_exec (inf, exec_file_target);
1204 set_current_inferior (inf);
1205 set_current_program_space (inf->pspace);
1209 /* The old description may no longer be fit for the new image.
1210 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1211 old description; we'll read a new one below. No need to do
1212 this on "follow-exec-mode new", as the old inferior stays
1213 around (its description is later cleared/refetched on
1215 target_clear_description ();
1218 gdb_assert (current_program_space == inf->pspace);
1220 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1221 because the proper displacement for a PIE (Position Independent
1222 Executable) main symbol file will only be computed by
1223 solib_create_inferior_hook below. breakpoint_re_set would fail
1224 to insert the breakpoints with the zero displacement. */
1225 try_open_exec_file (exec_file_host, inf, SYMFILE_DEFER_BP_RESET);
1227 do_cleanups (old_chain);
1229 /* If the target can specify a description, read it. Must do this
1230 after flipping to the new executable (because the target supplied
1231 description must be compatible with the executable's
1232 architecture, and the old executable may e.g., be 32-bit, while
1233 the new one 64-bit), and before anything involving memory or
1235 target_find_description ();
1237 /* The add_thread call ends up reading registers, so do it after updating the
1238 target description. */
1239 if (follow_exec_mode_string == follow_exec_mode_new)
1242 solib_create_inferior_hook (0);
1244 jit_inferior_created_hook ();
1246 breakpoint_re_set ();
1248 /* Reinsert all breakpoints. (Those which were symbolic have
1249 been reset to the proper address in the new a.out, thanks
1250 to symbol_file_command...). */
1251 insert_breakpoints ();
1253 /* The next resume of this inferior should bring it to the shlib
1254 startup breakpoints. (If the user had also set bp's on
1255 "main" from the old (parent) process, then they'll auto-
1256 matically get reset there in the new process.). */
1259 /* The queue of threads that need to do a step-over operation to get
1260 past e.g., a breakpoint. What technique is used to step over the
1261 breakpoint/watchpoint does not matter -- all threads end up in the
1262 same queue, to maintain rough temporal order of execution, in order
1263 to avoid starvation, otherwise, we could e.g., find ourselves
1264 constantly stepping the same couple threads past their breakpoints
1265 over and over, if the single-step finish fast enough. */
1266 struct thread_info *step_over_queue_head;
1268 /* Bit flags indicating what the thread needs to step over. */
1270 enum step_over_what_flag
1272 /* Step over a breakpoint. */
1273 STEP_OVER_BREAKPOINT = 1,
1275 /* Step past a non-continuable watchpoint, in order to let the
1276 instruction execute so we can evaluate the watchpoint
1278 STEP_OVER_WATCHPOINT = 2
1280 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1282 /* Info about an instruction that is being stepped over. */
1284 struct step_over_info
1286 /* If we're stepping past a breakpoint, this is the address space
1287 and address of the instruction the breakpoint is set at. We'll
1288 skip inserting all breakpoints here. Valid iff ASPACE is
1290 const address_space *aspace;
1293 /* The instruction being stepped over triggers a nonsteppable
1294 watchpoint. If true, we'll skip inserting watchpoints. */
1295 int nonsteppable_watchpoint_p;
1297 /* The thread's global number. */
1301 /* The step-over info of the location that is being stepped over.
1303 Note that with async/breakpoint always-inserted mode, a user might
1304 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1305 being stepped over. As setting a new breakpoint inserts all
1306 breakpoints, we need to make sure the breakpoint being stepped over
1307 isn't inserted then. We do that by only clearing the step-over
1308 info when the step-over is actually finished (or aborted).
1310 Presently GDB can only step over one breakpoint at any given time.
1311 Given threads that can't run code in the same address space as the
1312 breakpoint's can't really miss the breakpoint, GDB could be taught
1313 to step-over at most one breakpoint per address space (so this info
1314 could move to the address space object if/when GDB is extended).
1315 The set of breakpoints being stepped over will normally be much
1316 smaller than the set of all breakpoints, so a flag in the
1317 breakpoint location structure would be wasteful. A separate list
1318 also saves complexity and run-time, as otherwise we'd have to go
1319 through all breakpoint locations clearing their flag whenever we
1320 start a new sequence. Similar considerations weigh against storing
1321 this info in the thread object. Plus, not all step overs actually
1322 have breakpoint locations -- e.g., stepping past a single-step
1323 breakpoint, or stepping to complete a non-continuable
1325 static struct step_over_info step_over_info;
1327 /* Record the address of the breakpoint/instruction we're currently
1329 N.B. We record the aspace and address now, instead of say just the thread,
1330 because when we need the info later the thread may be running. */
1333 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1334 int nonsteppable_watchpoint_p,
1337 step_over_info.aspace = aspace;
1338 step_over_info.address = address;
1339 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1340 step_over_info.thread = thread;
1343 /* Called when we're not longer stepping over a breakpoint / an
1344 instruction, so all breakpoints are free to be (re)inserted. */
1347 clear_step_over_info (void)
1350 fprintf_unfiltered (gdb_stdlog,
1351 "infrun: clear_step_over_info\n");
1352 step_over_info.aspace = NULL;
1353 step_over_info.address = 0;
1354 step_over_info.nonsteppable_watchpoint_p = 0;
1355 step_over_info.thread = -1;
1361 stepping_past_instruction_at (struct address_space *aspace,
1364 return (step_over_info.aspace != NULL
1365 && breakpoint_address_match (aspace, address,
1366 step_over_info.aspace,
1367 step_over_info.address));
1373 thread_is_stepping_over_breakpoint (int thread)
1375 return (step_over_info.thread != -1
1376 && thread == step_over_info.thread);
1382 stepping_past_nonsteppable_watchpoint (void)
1384 return step_over_info.nonsteppable_watchpoint_p;
1387 /* Returns true if step-over info is valid. */
1390 step_over_info_valid_p (void)
1392 return (step_over_info.aspace != NULL
1393 || stepping_past_nonsteppable_watchpoint ());
1397 /* Displaced stepping. */
1399 /* In non-stop debugging mode, we must take special care to manage
1400 breakpoints properly; in particular, the traditional strategy for
1401 stepping a thread past a breakpoint it has hit is unsuitable.
1402 'Displaced stepping' is a tactic for stepping one thread past a
1403 breakpoint it has hit while ensuring that other threads running
1404 concurrently will hit the breakpoint as they should.
1406 The traditional way to step a thread T off a breakpoint in a
1407 multi-threaded program in all-stop mode is as follows:
1409 a0) Initially, all threads are stopped, and breakpoints are not
1411 a1) We single-step T, leaving breakpoints uninserted.
1412 a2) We insert breakpoints, and resume all threads.
1414 In non-stop debugging, however, this strategy is unsuitable: we
1415 don't want to have to stop all threads in the system in order to
1416 continue or step T past a breakpoint. Instead, we use displaced
1419 n0) Initially, T is stopped, other threads are running, and
1420 breakpoints are inserted.
1421 n1) We copy the instruction "under" the breakpoint to a separate
1422 location, outside the main code stream, making any adjustments
1423 to the instruction, register, and memory state as directed by
1425 n2) We single-step T over the instruction at its new location.
1426 n3) We adjust the resulting register and memory state as directed
1427 by T's architecture. This includes resetting T's PC to point
1428 back into the main instruction stream.
1431 This approach depends on the following gdbarch methods:
1433 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1434 indicate where to copy the instruction, and how much space must
1435 be reserved there. We use these in step n1.
1437 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1438 address, and makes any necessary adjustments to the instruction,
1439 register contents, and memory. We use this in step n1.
1441 - gdbarch_displaced_step_fixup adjusts registers and memory after
1442 we have successfuly single-stepped the instruction, to yield the
1443 same effect the instruction would have had if we had executed it
1444 at its original address. We use this in step n3.
1446 The gdbarch_displaced_step_copy_insn and
1447 gdbarch_displaced_step_fixup functions must be written so that
1448 copying an instruction with gdbarch_displaced_step_copy_insn,
1449 single-stepping across the copied instruction, and then applying
1450 gdbarch_displaced_insn_fixup should have the same effects on the
1451 thread's memory and registers as stepping the instruction in place
1452 would have. Exactly which responsibilities fall to the copy and
1453 which fall to the fixup is up to the author of those functions.
1455 See the comments in gdbarch.sh for details.
1457 Note that displaced stepping and software single-step cannot
1458 currently be used in combination, although with some care I think
1459 they could be made to. Software single-step works by placing
1460 breakpoints on all possible subsequent instructions; if the
1461 displaced instruction is a PC-relative jump, those breakpoints
1462 could fall in very strange places --- on pages that aren't
1463 executable, or at addresses that are not proper instruction
1464 boundaries. (We do generally let other threads run while we wait
1465 to hit the software single-step breakpoint, and they might
1466 encounter such a corrupted instruction.) One way to work around
1467 this would be to have gdbarch_displaced_step_copy_insn fully
1468 simulate the effect of PC-relative instructions (and return NULL)
1469 on architectures that use software single-stepping.
1471 In non-stop mode, we can have independent and simultaneous step
1472 requests, so more than one thread may need to simultaneously step
1473 over a breakpoint. The current implementation assumes there is
1474 only one scratch space per process. In this case, we have to
1475 serialize access to the scratch space. If thread A wants to step
1476 over a breakpoint, but we are currently waiting for some other
1477 thread to complete a displaced step, we leave thread A stopped and
1478 place it in the displaced_step_request_queue. Whenever a displaced
1479 step finishes, we pick the next thread in the queue and start a new
1480 displaced step operation on it. See displaced_step_prepare and
1481 displaced_step_fixup for details. */
1483 /* Default destructor for displaced_step_closure. */
1485 displaced_step_closure::~displaced_step_closure () = default;
1487 /* Per-inferior displaced stepping state. */
1488 struct displaced_step_inferior_state
1490 /* Pointer to next in linked list. */
1491 struct displaced_step_inferior_state *next;
1493 /* The process this displaced step state refers to. */
1496 /* True if preparing a displaced step ever failed. If so, we won't
1497 try displaced stepping for this inferior again. */
1500 /* If this is not null_ptid, this is the thread carrying out a
1501 displaced single-step in process PID. This thread's state will
1502 require fixing up once it has completed its step. */
1505 /* The architecture the thread had when we stepped it. */
1506 struct gdbarch *step_gdbarch;
1508 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1509 for post-step cleanup. */
1510 struct displaced_step_closure *step_closure;
1512 /* The address of the original instruction, and the copy we
1514 CORE_ADDR step_original, step_copy;
1516 /* Saved contents of copy area. */
1517 gdb_byte *step_saved_copy;
1520 /* The list of states of processes involved in displaced stepping
1522 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1524 /* Get the displaced stepping state of process PID. */
1526 static struct displaced_step_inferior_state *
1527 get_displaced_stepping_state (int pid)
1529 struct displaced_step_inferior_state *state;
1531 for (state = displaced_step_inferior_states;
1533 state = state->next)
1534 if (state->pid == pid)
1540 /* Returns true if any inferior has a thread doing a displaced
1544 displaced_step_in_progress_any_inferior (void)
1546 struct displaced_step_inferior_state *state;
1548 for (state = displaced_step_inferior_states;
1550 state = state->next)
1551 if (!ptid_equal (state->step_ptid, null_ptid))
1557 /* Return true if thread represented by PTID is doing a displaced
1561 displaced_step_in_progress_thread (ptid_t ptid)
1563 struct displaced_step_inferior_state *displaced;
1565 gdb_assert (!ptid_equal (ptid, null_ptid));
1567 displaced = get_displaced_stepping_state (ptid_get_pid (ptid));
1569 return (displaced != NULL && ptid_equal (displaced->step_ptid, ptid));
1572 /* Return true if process PID has a thread doing a displaced step. */
1575 displaced_step_in_progress (int pid)
1577 struct displaced_step_inferior_state *displaced;
1579 displaced = get_displaced_stepping_state (pid);
1580 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1586 /* Add a new displaced stepping state for process PID to the displaced
1587 stepping state list, or return a pointer to an already existing
1588 entry, if it already exists. Never returns NULL. */
1590 static struct displaced_step_inferior_state *
1591 add_displaced_stepping_state (int pid)
1593 struct displaced_step_inferior_state *state;
1595 for (state = displaced_step_inferior_states;
1597 state = state->next)
1598 if (state->pid == pid)
1601 state = XCNEW (struct displaced_step_inferior_state);
1603 state->next = displaced_step_inferior_states;
1604 displaced_step_inferior_states = state;
1609 /* If inferior is in displaced stepping, and ADDR equals to starting address
1610 of copy area, return corresponding displaced_step_closure. Otherwise,
1613 struct displaced_step_closure*
1614 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1616 struct displaced_step_inferior_state *displaced
1617 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1619 /* If checking the mode of displaced instruction in copy area. */
1620 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1621 && (displaced->step_copy == addr))
1622 return displaced->step_closure;
1627 /* Remove the displaced stepping state of process PID. */
1630 remove_displaced_stepping_state (int pid)
1632 struct displaced_step_inferior_state *it, **prev_next_p;
1634 gdb_assert (pid != 0);
1636 it = displaced_step_inferior_states;
1637 prev_next_p = &displaced_step_inferior_states;
1642 *prev_next_p = it->next;
1647 prev_next_p = &it->next;
1653 infrun_inferior_exit (struct inferior *inf)
1655 remove_displaced_stepping_state (inf->pid);
1658 /* If ON, and the architecture supports it, GDB will use displaced
1659 stepping to step over breakpoints. If OFF, or if the architecture
1660 doesn't support it, GDB will instead use the traditional
1661 hold-and-step approach. If AUTO (which is the default), GDB will
1662 decide which technique to use to step over breakpoints depending on
1663 which of all-stop or non-stop mode is active --- displaced stepping
1664 in non-stop mode; hold-and-step in all-stop mode. */
1666 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1669 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1670 struct cmd_list_element *c,
1673 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1674 fprintf_filtered (file,
1675 _("Debugger's willingness to use displaced stepping "
1676 "to step over breakpoints is %s (currently %s).\n"),
1677 value, target_is_non_stop_p () ? "on" : "off");
1679 fprintf_filtered (file,
1680 _("Debugger's willingness to use displaced stepping "
1681 "to step over breakpoints is %s.\n"), value);
1684 /* Return non-zero if displaced stepping can/should be used to step
1685 over breakpoints of thread TP. */
1688 use_displaced_stepping (struct thread_info *tp)
1690 struct regcache *regcache = get_thread_regcache (tp->ptid);
1691 struct gdbarch *gdbarch = regcache->arch ();
1692 struct displaced_step_inferior_state *displaced_state;
1694 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
1696 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1697 && target_is_non_stop_p ())
1698 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1699 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1700 && find_record_target () == NULL
1701 && (displaced_state == NULL
1702 || !displaced_state->failed_before));
1705 /* Clean out any stray displaced stepping state. */
1707 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1709 /* Indicate that there is no cleanup pending. */
1710 displaced->step_ptid = null_ptid;
1712 delete displaced->step_closure;
1713 displaced->step_closure = NULL;
1717 displaced_step_clear_cleanup (void *arg)
1719 struct displaced_step_inferior_state *state
1720 = (struct displaced_step_inferior_state *) arg;
1722 displaced_step_clear (state);
1725 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1727 displaced_step_dump_bytes (struct ui_file *file,
1728 const gdb_byte *buf,
1733 for (i = 0; i < len; i++)
1734 fprintf_unfiltered (file, "%02x ", buf[i]);
1735 fputs_unfiltered ("\n", file);
1738 /* Prepare to single-step, using displaced stepping.
1740 Note that we cannot use displaced stepping when we have a signal to
1741 deliver. If we have a signal to deliver and an instruction to step
1742 over, then after the step, there will be no indication from the
1743 target whether the thread entered a signal handler or ignored the
1744 signal and stepped over the instruction successfully --- both cases
1745 result in a simple SIGTRAP. In the first case we mustn't do a
1746 fixup, and in the second case we must --- but we can't tell which.
1747 Comments in the code for 'random signals' in handle_inferior_event
1748 explain how we handle this case instead.
1750 Returns 1 if preparing was successful -- this thread is going to be
1751 stepped now; 0 if displaced stepping this thread got queued; or -1
1752 if this instruction can't be displaced stepped. */
1755 displaced_step_prepare_throw (ptid_t ptid)
1757 struct cleanup *ignore_cleanups;
1758 struct thread_info *tp = find_thread_ptid (ptid);
1759 struct regcache *regcache = get_thread_regcache (ptid);
1760 struct gdbarch *gdbarch = regcache->arch ();
1761 const address_space *aspace = regcache->aspace ();
1762 CORE_ADDR original, copy;
1764 struct displaced_step_closure *closure;
1765 struct displaced_step_inferior_state *displaced;
1768 /* We should never reach this function if the architecture does not
1769 support displaced stepping. */
1770 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1772 /* Nor if the thread isn't meant to step over a breakpoint. */
1773 gdb_assert (tp->control.trap_expected);
1775 /* Disable range stepping while executing in the scratch pad. We
1776 want a single-step even if executing the displaced instruction in
1777 the scratch buffer lands within the stepping range (e.g., a
1779 tp->control.may_range_step = 0;
1781 /* We have to displaced step one thread at a time, as we only have
1782 access to a single scratch space per inferior. */
1784 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1786 if (!ptid_equal (displaced->step_ptid, null_ptid))
1788 /* Already waiting for a displaced step to finish. Defer this
1789 request and place in queue. */
1791 if (debug_displaced)
1792 fprintf_unfiltered (gdb_stdlog,
1793 "displaced: deferring step of %s\n",
1794 target_pid_to_str (ptid));
1796 thread_step_over_chain_enqueue (tp);
1801 if (debug_displaced)
1802 fprintf_unfiltered (gdb_stdlog,
1803 "displaced: stepping %s now\n",
1804 target_pid_to_str (ptid));
1807 displaced_step_clear (displaced);
1809 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1810 inferior_ptid = ptid;
1812 original = regcache_read_pc (regcache);
1814 copy = gdbarch_displaced_step_location (gdbarch);
1815 len = gdbarch_max_insn_length (gdbarch);
1817 if (breakpoint_in_range_p (aspace, copy, len))
1819 /* There's a breakpoint set in the scratch pad location range
1820 (which is usually around the entry point). We'd either
1821 install it before resuming, which would overwrite/corrupt the
1822 scratch pad, or if it was already inserted, this displaced
1823 step would overwrite it. The latter is OK in the sense that
1824 we already assume that no thread is going to execute the code
1825 in the scratch pad range (after initial startup) anyway, but
1826 the former is unacceptable. Simply punt and fallback to
1827 stepping over this breakpoint in-line. */
1828 if (debug_displaced)
1830 fprintf_unfiltered (gdb_stdlog,
1831 "displaced: breakpoint set in scratch pad. "
1832 "Stepping over breakpoint in-line instead.\n");
1838 /* Save the original contents of the copy area. */
1839 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1840 ignore_cleanups = make_cleanup (free_current_contents,
1841 &displaced->step_saved_copy);
1842 status = target_read_memory (copy, displaced->step_saved_copy, len);
1844 throw_error (MEMORY_ERROR,
1845 _("Error accessing memory address %s (%s) for "
1846 "displaced-stepping scratch space."),
1847 paddress (gdbarch, copy), safe_strerror (status));
1848 if (debug_displaced)
1850 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1851 paddress (gdbarch, copy));
1852 displaced_step_dump_bytes (gdb_stdlog,
1853 displaced->step_saved_copy,
1857 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1858 original, copy, regcache);
1859 if (closure == NULL)
1861 /* The architecture doesn't know how or want to displaced step
1862 this instruction or instruction sequence. Fallback to
1863 stepping over the breakpoint in-line. */
1864 do_cleanups (ignore_cleanups);
1868 /* Save the information we need to fix things up if the step
1870 displaced->step_ptid = ptid;
1871 displaced->step_gdbarch = gdbarch;
1872 displaced->step_closure = closure;
1873 displaced->step_original = original;
1874 displaced->step_copy = copy;
1876 make_cleanup (displaced_step_clear_cleanup, displaced);
1878 /* Resume execution at the copy. */
1879 regcache_write_pc (regcache, copy);
1881 discard_cleanups (ignore_cleanups);
1883 if (debug_displaced)
1884 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1885 paddress (gdbarch, copy));
1890 /* Wrapper for displaced_step_prepare_throw that disabled further
1891 attempts at displaced stepping if we get a memory error. */
1894 displaced_step_prepare (ptid_t ptid)
1900 prepared = displaced_step_prepare_throw (ptid);
1902 CATCH (ex, RETURN_MASK_ERROR)
1904 struct displaced_step_inferior_state *displaced_state;
1906 if (ex.error != MEMORY_ERROR
1907 && ex.error != NOT_SUPPORTED_ERROR)
1908 throw_exception (ex);
1912 fprintf_unfiltered (gdb_stdlog,
1913 "infrun: disabling displaced stepping: %s\n",
1917 /* Be verbose if "set displaced-stepping" is "on", silent if
1919 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1921 warning (_("disabling displaced stepping: %s"),
1925 /* Disable further displaced stepping attempts. */
1927 = get_displaced_stepping_state (ptid_get_pid (ptid));
1928 displaced_state->failed_before = 1;
1936 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1937 const gdb_byte *myaddr, int len)
1939 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1941 inferior_ptid = ptid;
1942 write_memory (memaddr, myaddr, len);
1945 /* Restore the contents of the copy area for thread PTID. */
1948 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1951 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1953 write_memory_ptid (ptid, displaced->step_copy,
1954 displaced->step_saved_copy, len);
1955 if (debug_displaced)
1956 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1957 target_pid_to_str (ptid),
1958 paddress (displaced->step_gdbarch,
1959 displaced->step_copy));
1962 /* If we displaced stepped an instruction successfully, adjust
1963 registers and memory to yield the same effect the instruction would
1964 have had if we had executed it at its original address, and return
1965 1. If the instruction didn't complete, relocate the PC and return
1966 -1. If the thread wasn't displaced stepping, return 0. */
1969 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1971 struct cleanup *old_cleanups;
1972 struct displaced_step_inferior_state *displaced
1973 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1976 /* Was any thread of this process doing a displaced step? */
1977 if (displaced == NULL)
1980 /* Was this event for the pid we displaced? */
1981 if (ptid_equal (displaced->step_ptid, null_ptid)
1982 || ! ptid_equal (displaced->step_ptid, event_ptid))
1985 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1987 displaced_step_restore (displaced, displaced->step_ptid);
1989 /* Fixup may need to read memory/registers. Switch to the thread
1990 that we're fixing up. Also, target_stopped_by_watchpoint checks
1991 the current thread. */
1992 switch_to_thread (event_ptid);
1994 /* Did the instruction complete successfully? */
1995 if (signal == GDB_SIGNAL_TRAP
1996 && !(target_stopped_by_watchpoint ()
1997 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1998 || target_have_steppable_watchpoint)))
2000 /* Fix up the resulting state. */
2001 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
2002 displaced->step_closure,
2003 displaced->step_original,
2004 displaced->step_copy,
2005 get_thread_regcache (displaced->step_ptid));
2010 /* Since the instruction didn't complete, all we can do is
2012 struct regcache *regcache = get_thread_regcache (event_ptid);
2013 CORE_ADDR pc = regcache_read_pc (regcache);
2015 pc = displaced->step_original + (pc - displaced->step_copy);
2016 regcache_write_pc (regcache, pc);
2020 do_cleanups (old_cleanups);
2022 displaced->step_ptid = null_ptid;
2027 /* Data to be passed around while handling an event. This data is
2028 discarded between events. */
2029 struct execution_control_state
2032 /* The thread that got the event, if this was a thread event; NULL
2034 struct thread_info *event_thread;
2036 struct target_waitstatus ws;
2037 int stop_func_filled_in;
2038 CORE_ADDR stop_func_start;
2039 CORE_ADDR stop_func_end;
2040 const char *stop_func_name;
2043 /* True if the event thread hit the single-step breakpoint of
2044 another thread. Thus the event doesn't cause a stop, the thread
2045 needs to be single-stepped past the single-step breakpoint before
2046 we can switch back to the original stepping thread. */
2047 int hit_singlestep_breakpoint;
2050 /* Clear ECS and set it to point at TP. */
2053 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2055 memset (ecs, 0, sizeof (*ecs));
2056 ecs->event_thread = tp;
2057 ecs->ptid = tp->ptid;
2060 static void keep_going_pass_signal (struct execution_control_state *ecs);
2061 static void prepare_to_wait (struct execution_control_state *ecs);
2062 static int keep_going_stepped_thread (struct thread_info *tp);
2063 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2065 /* Are there any pending step-over requests? If so, run all we can
2066 now and return true. Otherwise, return false. */
2069 start_step_over (void)
2071 struct thread_info *tp, *next;
2073 /* Don't start a new step-over if we already have an in-line
2074 step-over operation ongoing. */
2075 if (step_over_info_valid_p ())
2078 for (tp = step_over_queue_head; tp != NULL; tp = next)
2080 struct execution_control_state ecss;
2081 struct execution_control_state *ecs = &ecss;
2082 step_over_what step_what;
2083 int must_be_in_line;
2085 gdb_assert (!tp->stop_requested);
2087 next = thread_step_over_chain_next (tp);
2089 /* If this inferior already has a displaced step in process,
2090 don't start a new one. */
2091 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2094 step_what = thread_still_needs_step_over (tp);
2095 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2096 || ((step_what & STEP_OVER_BREAKPOINT)
2097 && !use_displaced_stepping (tp)));
2099 /* We currently stop all threads of all processes to step-over
2100 in-line. If we need to start a new in-line step-over, let
2101 any pending displaced steps finish first. */
2102 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2105 thread_step_over_chain_remove (tp);
2107 if (step_over_queue_head == NULL)
2110 fprintf_unfiltered (gdb_stdlog,
2111 "infrun: step-over queue now empty\n");
2114 if (tp->control.trap_expected
2118 internal_error (__FILE__, __LINE__,
2119 "[%s] has inconsistent state: "
2120 "trap_expected=%d, resumed=%d, executing=%d\n",
2121 target_pid_to_str (tp->ptid),
2122 tp->control.trap_expected,
2128 fprintf_unfiltered (gdb_stdlog,
2129 "infrun: resuming [%s] for step-over\n",
2130 target_pid_to_str (tp->ptid));
2132 /* keep_going_pass_signal skips the step-over if the breakpoint
2133 is no longer inserted. In all-stop, we want to keep looking
2134 for a thread that needs a step-over instead of resuming TP,
2135 because we wouldn't be able to resume anything else until the
2136 target stops again. In non-stop, the resume always resumes
2137 only TP, so it's OK to let the thread resume freely. */
2138 if (!target_is_non_stop_p () && !step_what)
2141 switch_to_thread (tp->ptid);
2142 reset_ecs (ecs, tp);
2143 keep_going_pass_signal (ecs);
2145 if (!ecs->wait_some_more)
2146 error (_("Command aborted."));
2148 gdb_assert (tp->resumed);
2150 /* If we started a new in-line step-over, we're done. */
2151 if (step_over_info_valid_p ())
2153 gdb_assert (tp->control.trap_expected);
2157 if (!target_is_non_stop_p ())
2159 /* On all-stop, shouldn't have resumed unless we needed a
2161 gdb_assert (tp->control.trap_expected
2162 || tp->step_after_step_resume_breakpoint);
2164 /* With remote targets (at least), in all-stop, we can't
2165 issue any further remote commands until the program stops
2170 /* Either the thread no longer needed a step-over, or a new
2171 displaced stepping sequence started. Even in the latter
2172 case, continue looking. Maybe we can also start another
2173 displaced step on a thread of other process. */
2179 /* Update global variables holding ptids to hold NEW_PTID if they were
2180 holding OLD_PTID. */
2182 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2184 struct displaced_step_inferior_state *displaced;
2186 if (ptid_equal (inferior_ptid, old_ptid))
2187 inferior_ptid = new_ptid;
2189 for (displaced = displaced_step_inferior_states;
2191 displaced = displaced->next)
2193 if (ptid_equal (displaced->step_ptid, old_ptid))
2194 displaced->step_ptid = new_ptid;
2201 /* Things to clean up if we QUIT out of resume (). */
2203 resume_cleanups (void *ignore)
2205 if (!ptid_equal (inferior_ptid, null_ptid))
2206 delete_single_step_breakpoints (inferior_thread ());
2211 static const char schedlock_off[] = "off";
2212 static const char schedlock_on[] = "on";
2213 static const char schedlock_step[] = "step";
2214 static const char schedlock_replay[] = "replay";
2215 static const char *const scheduler_enums[] = {
2222 static const char *scheduler_mode = schedlock_replay;
2224 show_scheduler_mode (struct ui_file *file, int from_tty,
2225 struct cmd_list_element *c, const char *value)
2227 fprintf_filtered (file,
2228 _("Mode for locking scheduler "
2229 "during execution is \"%s\".\n"),
2234 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2236 if (!target_can_lock_scheduler)
2238 scheduler_mode = schedlock_off;
2239 error (_("Target '%s' cannot support this command."), target_shortname);
2243 /* True if execution commands resume all threads of all processes by
2244 default; otherwise, resume only threads of the current inferior
2246 int sched_multi = 0;
2248 /* Try to setup for software single stepping over the specified location.
2249 Return 1 if target_resume() should use hardware single step.
2251 GDBARCH the current gdbarch.
2252 PC the location to step over. */
2255 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2259 if (execution_direction == EXEC_FORWARD
2260 && gdbarch_software_single_step_p (gdbarch))
2261 hw_step = !insert_single_step_breakpoints (gdbarch);
2269 user_visible_resume_ptid (int step)
2275 /* With non-stop mode on, threads are always handled
2277 resume_ptid = inferior_ptid;
2279 else if ((scheduler_mode == schedlock_on)
2280 || (scheduler_mode == schedlock_step && step))
2282 /* User-settable 'scheduler' mode requires solo thread
2284 resume_ptid = inferior_ptid;
2286 else if ((scheduler_mode == schedlock_replay)
2287 && target_record_will_replay (minus_one_ptid, execution_direction))
2289 /* User-settable 'scheduler' mode requires solo thread resume in replay
2291 resume_ptid = inferior_ptid;
2293 else if (!sched_multi && target_supports_multi_process ())
2295 /* Resume all threads of the current process (and none of other
2297 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2301 /* Resume all threads of all processes. */
2302 resume_ptid = RESUME_ALL;
2308 /* Return a ptid representing the set of threads that we will resume,
2309 in the perspective of the target, assuming run control handling
2310 does not require leaving some threads stopped (e.g., stepping past
2311 breakpoint). USER_STEP indicates whether we're about to start the
2312 target for a stepping command. */
2315 internal_resume_ptid (int user_step)
2317 /* In non-stop, we always control threads individually. Note that
2318 the target may always work in non-stop mode even with "set
2319 non-stop off", in which case user_visible_resume_ptid could
2320 return a wildcard ptid. */
2321 if (target_is_non_stop_p ())
2322 return inferior_ptid;
2324 return user_visible_resume_ptid (user_step);
2327 /* Wrapper for target_resume, that handles infrun-specific
2331 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2333 struct thread_info *tp = inferior_thread ();
2335 gdb_assert (!tp->stop_requested);
2337 /* Install inferior's terminal modes. */
2338 target_terminal::inferior ();
2340 /* Avoid confusing the next resume, if the next stop/resume
2341 happens to apply to another thread. */
2342 tp->suspend.stop_signal = GDB_SIGNAL_0;
2344 /* Advise target which signals may be handled silently.
2346 If we have removed breakpoints because we are stepping over one
2347 in-line (in any thread), we need to receive all signals to avoid
2348 accidentally skipping a breakpoint during execution of a signal
2351 Likewise if we're displaced stepping, otherwise a trap for a
2352 breakpoint in a signal handler might be confused with the
2353 displaced step finishing. We don't make the displaced_step_fixup
2354 step distinguish the cases instead, because:
2356 - a backtrace while stopped in the signal handler would show the
2357 scratch pad as frame older than the signal handler, instead of
2358 the real mainline code.
2360 - when the thread is later resumed, the signal handler would
2361 return to the scratch pad area, which would no longer be
2363 if (step_over_info_valid_p ()
2364 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2365 target_pass_signals (0, NULL);
2367 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2369 target_resume (resume_ptid, step, sig);
2371 target_commit_resume ();
2374 /* Resume the inferior, but allow a QUIT. This is useful if the user
2375 wants to interrupt some lengthy single-stepping operation
2376 (for child processes, the SIGINT goes to the inferior, and so
2377 we get a SIGINT random_signal, but for remote debugging and perhaps
2378 other targets, that's not true).
2380 SIG is the signal to give the inferior (zero for none). */
2382 resume (enum gdb_signal sig)
2384 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2385 struct regcache *regcache = get_current_regcache ();
2386 struct gdbarch *gdbarch = regcache->arch ();
2387 struct thread_info *tp = inferior_thread ();
2388 CORE_ADDR pc = regcache_read_pc (regcache);
2389 const address_space *aspace = regcache->aspace ();
2391 /* This represents the user's step vs continue request. When
2392 deciding whether "set scheduler-locking step" applies, it's the
2393 user's intention that counts. */
2394 const int user_step = tp->control.stepping_command;
2395 /* This represents what we'll actually request the target to do.
2396 This can decay from a step to a continue, if e.g., we need to
2397 implement single-stepping with breakpoints (software
2401 gdb_assert (!tp->stop_requested);
2402 gdb_assert (!thread_is_in_step_over_chain (tp));
2406 if (tp->suspend.waitstatus_pending_p)
2411 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2413 fprintf_unfiltered (gdb_stdlog,
2414 "infrun: resume: thread %s has pending wait "
2415 "status %s (currently_stepping=%d).\n",
2416 target_pid_to_str (tp->ptid), statstr.c_str (),
2417 currently_stepping (tp));
2422 /* FIXME: What should we do if we are supposed to resume this
2423 thread with a signal? Maybe we should maintain a queue of
2424 pending signals to deliver. */
2425 if (sig != GDB_SIGNAL_0)
2427 warning (_("Couldn't deliver signal %s to %s."),
2428 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2431 tp->suspend.stop_signal = GDB_SIGNAL_0;
2432 discard_cleanups (old_cleanups);
2434 if (target_can_async_p ())
2439 tp->stepped_breakpoint = 0;
2441 /* Depends on stepped_breakpoint. */
2442 step = currently_stepping (tp);
2444 if (current_inferior ()->waiting_for_vfork_done)
2446 /* Don't try to single-step a vfork parent that is waiting for
2447 the child to get out of the shared memory region (by exec'ing
2448 or exiting). This is particularly important on software
2449 single-step archs, as the child process would trip on the
2450 software single step breakpoint inserted for the parent
2451 process. Since the parent will not actually execute any
2452 instruction until the child is out of the shared region (such
2453 are vfork's semantics), it is safe to simply continue it.
2454 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2455 the parent, and tell it to `keep_going', which automatically
2456 re-sets it stepping. */
2458 fprintf_unfiltered (gdb_stdlog,
2459 "infrun: resume : clear step\n");
2464 fprintf_unfiltered (gdb_stdlog,
2465 "infrun: resume (step=%d, signal=%s), "
2466 "trap_expected=%d, current thread [%s] at %s\n",
2467 step, gdb_signal_to_symbol_string (sig),
2468 tp->control.trap_expected,
2469 target_pid_to_str (inferior_ptid),
2470 paddress (gdbarch, pc));
2472 /* Normally, by the time we reach `resume', the breakpoints are either
2473 removed or inserted, as appropriate. The exception is if we're sitting
2474 at a permanent breakpoint; we need to step over it, but permanent
2475 breakpoints can't be removed. So we have to test for it here. */
2476 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2478 if (sig != GDB_SIGNAL_0)
2480 /* We have a signal to pass to the inferior. The resume
2481 may, or may not take us to the signal handler. If this
2482 is a step, we'll need to stop in the signal handler, if
2483 there's one, (if the target supports stepping into
2484 handlers), or in the next mainline instruction, if
2485 there's no handler. If this is a continue, we need to be
2486 sure to run the handler with all breakpoints inserted.
2487 In all cases, set a breakpoint at the current address
2488 (where the handler returns to), and once that breakpoint
2489 is hit, resume skipping the permanent breakpoint. If
2490 that breakpoint isn't hit, then we've stepped into the
2491 signal handler (or hit some other event). We'll delete
2492 the step-resume breakpoint then. */
2495 fprintf_unfiltered (gdb_stdlog,
2496 "infrun: resume: skipping permanent breakpoint, "
2497 "deliver signal first\n");
2499 clear_step_over_info ();
2500 tp->control.trap_expected = 0;
2502 if (tp->control.step_resume_breakpoint == NULL)
2504 /* Set a "high-priority" step-resume, as we don't want
2505 user breakpoints at PC to trigger (again) when this
2507 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2508 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2510 tp->step_after_step_resume_breakpoint = step;
2513 insert_breakpoints ();
2517 /* There's no signal to pass, we can go ahead and skip the
2518 permanent breakpoint manually. */
2520 fprintf_unfiltered (gdb_stdlog,
2521 "infrun: resume: skipping permanent breakpoint\n");
2522 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2523 /* Update pc to reflect the new address from which we will
2524 execute instructions. */
2525 pc = regcache_read_pc (regcache);
2529 /* We've already advanced the PC, so the stepping part
2530 is done. Now we need to arrange for a trap to be
2531 reported to handle_inferior_event. Set a breakpoint
2532 at the current PC, and run to it. Don't update
2533 prev_pc, because if we end in
2534 switch_back_to_stepped_thread, we want the "expected
2535 thread advanced also" branch to be taken. IOW, we
2536 don't want this thread to step further from PC
2538 gdb_assert (!step_over_info_valid_p ());
2539 insert_single_step_breakpoint (gdbarch, aspace, pc);
2540 insert_breakpoints ();
2542 resume_ptid = internal_resume_ptid (user_step);
2543 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2544 discard_cleanups (old_cleanups);
2551 /* If we have a breakpoint to step over, make sure to do a single
2552 step only. Same if we have software watchpoints. */
2553 if (tp->control.trap_expected || bpstat_should_step ())
2554 tp->control.may_range_step = 0;
2556 /* If enabled, step over breakpoints by executing a copy of the
2557 instruction at a different address.
2559 We can't use displaced stepping when we have a signal to deliver;
2560 the comments for displaced_step_prepare explain why. The
2561 comments in the handle_inferior event for dealing with 'random
2562 signals' explain what we do instead.
2564 We can't use displaced stepping when we are waiting for vfork_done
2565 event, displaced stepping breaks the vfork child similarly as single
2566 step software breakpoint. */
2567 if (tp->control.trap_expected
2568 && use_displaced_stepping (tp)
2569 && !step_over_info_valid_p ()
2570 && sig == GDB_SIGNAL_0
2571 && !current_inferior ()->waiting_for_vfork_done)
2573 int prepared = displaced_step_prepare (inferior_ptid);
2578 fprintf_unfiltered (gdb_stdlog,
2579 "Got placed in step-over queue\n");
2581 tp->control.trap_expected = 0;
2582 discard_cleanups (old_cleanups);
2585 else if (prepared < 0)
2587 /* Fallback to stepping over the breakpoint in-line. */
2589 if (target_is_non_stop_p ())
2590 stop_all_threads ();
2592 set_step_over_info (regcache->aspace (),
2593 regcache_read_pc (regcache), 0, tp->global_num);
2595 step = maybe_software_singlestep (gdbarch, pc);
2597 insert_breakpoints ();
2599 else if (prepared > 0)
2601 struct displaced_step_inferior_state *displaced;
2603 /* Update pc to reflect the new address from which we will
2604 execute instructions due to displaced stepping. */
2605 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2607 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2608 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2609 displaced->step_closure);
2613 /* Do we need to do it the hard way, w/temp breakpoints? */
2615 step = maybe_software_singlestep (gdbarch, pc);
2617 /* Currently, our software single-step implementation leads to different
2618 results than hardware single-stepping in one situation: when stepping
2619 into delivering a signal which has an associated signal handler,
2620 hardware single-step will stop at the first instruction of the handler,
2621 while software single-step will simply skip execution of the handler.
2623 For now, this difference in behavior is accepted since there is no
2624 easy way to actually implement single-stepping into a signal handler
2625 without kernel support.
2627 However, there is one scenario where this difference leads to follow-on
2628 problems: if we're stepping off a breakpoint by removing all breakpoints
2629 and then single-stepping. In this case, the software single-step
2630 behavior means that even if there is a *breakpoint* in the signal
2631 handler, GDB still would not stop.
2633 Fortunately, we can at least fix this particular issue. We detect
2634 here the case where we are about to deliver a signal while software
2635 single-stepping with breakpoints removed. In this situation, we
2636 revert the decisions to remove all breakpoints and insert single-
2637 step breakpoints, and instead we install a step-resume breakpoint
2638 at the current address, deliver the signal without stepping, and
2639 once we arrive back at the step-resume breakpoint, actually step
2640 over the breakpoint we originally wanted to step over. */
2641 if (thread_has_single_step_breakpoints_set (tp)
2642 && sig != GDB_SIGNAL_0
2643 && step_over_info_valid_p ())
2645 /* If we have nested signals or a pending signal is delivered
2646 immediately after a handler returns, might might already have
2647 a step-resume breakpoint set on the earlier handler. We cannot
2648 set another step-resume breakpoint; just continue on until the
2649 original breakpoint is hit. */
2650 if (tp->control.step_resume_breakpoint == NULL)
2652 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2653 tp->step_after_step_resume_breakpoint = 1;
2656 delete_single_step_breakpoints (tp);
2658 clear_step_over_info ();
2659 tp->control.trap_expected = 0;
2661 insert_breakpoints ();
2664 /* If STEP is set, it's a request to use hardware stepping
2665 facilities. But in that case, we should never
2666 use singlestep breakpoint. */
2667 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2669 /* Decide the set of threads to ask the target to resume. */
2670 if (tp->control.trap_expected)
2672 /* We're allowing a thread to run past a breakpoint it has
2673 hit, either by single-stepping the thread with the breakpoint
2674 removed, or by displaced stepping, with the breakpoint inserted.
2675 In the former case, we need to single-step only this thread,
2676 and keep others stopped, as they can miss this breakpoint if
2677 allowed to run. That's not really a problem for displaced
2678 stepping, but, we still keep other threads stopped, in case
2679 another thread is also stopped for a breakpoint waiting for
2680 its turn in the displaced stepping queue. */
2681 resume_ptid = inferior_ptid;
2684 resume_ptid = internal_resume_ptid (user_step);
2686 if (execution_direction != EXEC_REVERSE
2687 && step && breakpoint_inserted_here_p (aspace, pc))
2689 /* There are two cases where we currently need to step a
2690 breakpoint instruction when we have a signal to deliver:
2692 - See handle_signal_stop where we handle random signals that
2693 could take out us out of the stepping range. Normally, in
2694 that case we end up continuing (instead of stepping) over the
2695 signal handler with a breakpoint at PC, but there are cases
2696 where we should _always_ single-step, even if we have a
2697 step-resume breakpoint, like when a software watchpoint is
2698 set. Assuming single-stepping and delivering a signal at the
2699 same time would takes us to the signal handler, then we could
2700 have removed the breakpoint at PC to step over it. However,
2701 some hardware step targets (like e.g., Mac OS) can't step
2702 into signal handlers, and for those, we need to leave the
2703 breakpoint at PC inserted, as otherwise if the handler
2704 recurses and executes PC again, it'll miss the breakpoint.
2705 So we leave the breakpoint inserted anyway, but we need to
2706 record that we tried to step a breakpoint instruction, so
2707 that adjust_pc_after_break doesn't end up confused.
2709 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2710 in one thread after another thread that was stepping had been
2711 momentarily paused for a step-over. When we re-resume the
2712 stepping thread, it may be resumed from that address with a
2713 breakpoint that hasn't trapped yet. Seen with
2714 gdb.threads/non-stop-fair-events.exp, on targets that don't
2715 do displaced stepping. */
2718 fprintf_unfiltered (gdb_stdlog,
2719 "infrun: resume: [%s] stepped breakpoint\n",
2720 target_pid_to_str (tp->ptid));
2722 tp->stepped_breakpoint = 1;
2724 /* Most targets can step a breakpoint instruction, thus
2725 executing it normally. But if this one cannot, just
2726 continue and we will hit it anyway. */
2727 if (gdbarch_cannot_step_breakpoint (gdbarch))
2732 && tp->control.trap_expected
2733 && use_displaced_stepping (tp)
2734 && !step_over_info_valid_p ())
2736 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2737 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2738 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2741 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2742 paddress (resume_gdbarch, actual_pc));
2743 read_memory (actual_pc, buf, sizeof (buf));
2744 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2747 if (tp->control.may_range_step)
2749 /* If we're resuming a thread with the PC out of the step
2750 range, then we're doing some nested/finer run control
2751 operation, like stepping the thread out of the dynamic
2752 linker or the displaced stepping scratch pad. We
2753 shouldn't have allowed a range step then. */
2754 gdb_assert (pc_in_thread_step_range (pc, tp));
2757 do_target_resume (resume_ptid, step, sig);
2759 discard_cleanups (old_cleanups);
2766 /* Counter that tracks number of user visible stops. This can be used
2767 to tell whether a command has proceeded the inferior past the
2768 current location. This allows e.g., inferior function calls in
2769 breakpoint commands to not interrupt the command list. When the
2770 call finishes successfully, the inferior is standing at the same
2771 breakpoint as if nothing happened (and so we don't call
2773 static ULONGEST current_stop_id;
2780 return current_stop_id;
2783 /* Called when we report a user visible stop. */
2791 /* Clear out all variables saying what to do when inferior is continued.
2792 First do this, then set the ones you want, then call `proceed'. */
2795 clear_proceed_status_thread (struct thread_info *tp)
2798 fprintf_unfiltered (gdb_stdlog,
2799 "infrun: clear_proceed_status_thread (%s)\n",
2800 target_pid_to_str (tp->ptid));
2802 /* If we're starting a new sequence, then the previous finished
2803 single-step is no longer relevant. */
2804 if (tp->suspend.waitstatus_pending_p)
2806 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2809 fprintf_unfiltered (gdb_stdlog,
2810 "infrun: clear_proceed_status: pending "
2811 "event of %s was a finished step. "
2813 target_pid_to_str (tp->ptid));
2815 tp->suspend.waitstatus_pending_p = 0;
2816 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2818 else if (debug_infrun)
2821 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2823 fprintf_unfiltered (gdb_stdlog,
2824 "infrun: clear_proceed_status_thread: thread %s "
2825 "has pending wait status %s "
2826 "(currently_stepping=%d).\n",
2827 target_pid_to_str (tp->ptid), statstr.c_str (),
2828 currently_stepping (tp));
2832 /* If this signal should not be seen by program, give it zero.
2833 Used for debugging signals. */
2834 if (!signal_pass_state (tp->suspend.stop_signal))
2835 tp->suspend.stop_signal = GDB_SIGNAL_0;
2837 thread_fsm_delete (tp->thread_fsm);
2838 tp->thread_fsm = NULL;
2840 tp->control.trap_expected = 0;
2841 tp->control.step_range_start = 0;
2842 tp->control.step_range_end = 0;
2843 tp->control.may_range_step = 0;
2844 tp->control.step_frame_id = null_frame_id;
2845 tp->control.step_stack_frame_id = null_frame_id;
2846 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2847 tp->control.step_start_function = NULL;
2848 tp->stop_requested = 0;
2850 tp->control.stop_step = 0;
2852 tp->control.proceed_to_finish = 0;
2854 tp->control.stepping_command = 0;
2856 /* Discard any remaining commands or status from previous stop. */
2857 bpstat_clear (&tp->control.stop_bpstat);
2861 clear_proceed_status (int step)
2863 /* With scheduler-locking replay, stop replaying other threads if we're
2864 not replaying the user-visible resume ptid.
2866 This is a convenience feature to not require the user to explicitly
2867 stop replaying the other threads. We're assuming that the user's
2868 intent is to resume tracing the recorded process. */
2869 if (!non_stop && scheduler_mode == schedlock_replay
2870 && target_record_is_replaying (minus_one_ptid)
2871 && !target_record_will_replay (user_visible_resume_ptid (step),
2872 execution_direction))
2873 target_record_stop_replaying ();
2877 struct thread_info *tp;
2880 resume_ptid = user_visible_resume_ptid (step);
2882 /* In all-stop mode, delete the per-thread status of all threads
2883 we're about to resume, implicitly and explicitly. */
2884 ALL_NON_EXITED_THREADS (tp)
2886 if (!ptid_match (tp->ptid, resume_ptid))
2888 clear_proceed_status_thread (tp);
2892 if (!ptid_equal (inferior_ptid, null_ptid))
2894 struct inferior *inferior;
2898 /* If in non-stop mode, only delete the per-thread status of
2899 the current thread. */
2900 clear_proceed_status_thread (inferior_thread ());
2903 inferior = current_inferior ();
2904 inferior->control.stop_soon = NO_STOP_QUIETLY;
2907 observer_notify_about_to_proceed ();
2910 /* Returns true if TP is still stopped at a breakpoint that needs
2911 stepping-over in order to make progress. If the breakpoint is gone
2912 meanwhile, we can skip the whole step-over dance. */
2915 thread_still_needs_step_over_bp (struct thread_info *tp)
2917 if (tp->stepping_over_breakpoint)
2919 struct regcache *regcache = get_thread_regcache (tp->ptid);
2921 if (breakpoint_here_p (regcache->aspace (),
2922 regcache_read_pc (regcache))
2923 == ordinary_breakpoint_here)
2926 tp->stepping_over_breakpoint = 0;
2932 /* Check whether thread TP still needs to start a step-over in order
2933 to make progress when resumed. Returns an bitwise or of enum
2934 step_over_what bits, indicating what needs to be stepped over. */
2936 static step_over_what
2937 thread_still_needs_step_over (struct thread_info *tp)
2939 step_over_what what = 0;
2941 if (thread_still_needs_step_over_bp (tp))
2942 what |= STEP_OVER_BREAKPOINT;
2944 if (tp->stepping_over_watchpoint
2945 && !target_have_steppable_watchpoint)
2946 what |= STEP_OVER_WATCHPOINT;
2951 /* Returns true if scheduler locking applies. STEP indicates whether
2952 we're about to do a step/next-like command to a thread. */
2955 schedlock_applies (struct thread_info *tp)
2957 return (scheduler_mode == schedlock_on
2958 || (scheduler_mode == schedlock_step
2959 && tp->control.stepping_command)
2960 || (scheduler_mode == schedlock_replay
2961 && target_record_will_replay (minus_one_ptid,
2962 execution_direction)));
2965 /* Basic routine for continuing the program in various fashions.
2967 ADDR is the address to resume at, or -1 for resume where stopped.
2968 SIGGNAL is the signal to give it, or 0 for none,
2969 or -1 for act according to how it stopped.
2970 STEP is nonzero if should trap after one instruction.
2971 -1 means return after that and print nothing.
2972 You should probably set various step_... variables
2973 before calling here, if you are stepping.
2975 You should call clear_proceed_status before calling proceed. */
2978 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2980 struct regcache *regcache;
2981 struct gdbarch *gdbarch;
2982 struct thread_info *tp;
2985 struct execution_control_state ecss;
2986 struct execution_control_state *ecs = &ecss;
2987 struct cleanup *old_chain;
2990 /* If we're stopped at a fork/vfork, follow the branch set by the
2991 "set follow-fork-mode" command; otherwise, we'll just proceed
2992 resuming the current thread. */
2993 if (!follow_fork ())
2995 /* The target for some reason decided not to resume. */
2997 if (target_can_async_p ())
2998 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3002 /* We'll update this if & when we switch to a new thread. */
3003 previous_inferior_ptid = inferior_ptid;
3005 regcache = get_current_regcache ();
3006 gdbarch = regcache->arch ();
3007 const address_space *aspace = regcache->aspace ();
3009 pc = regcache_read_pc (regcache);
3010 tp = inferior_thread ();
3012 /* Fill in with reasonable starting values. */
3013 init_thread_stepping_state (tp);
3015 gdb_assert (!thread_is_in_step_over_chain (tp));
3017 if (addr == (CORE_ADDR) -1)
3020 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
3021 && execution_direction != EXEC_REVERSE)
3022 /* There is a breakpoint at the address we will resume at,
3023 step one instruction before inserting breakpoints so that
3024 we do not stop right away (and report a second hit at this
3027 Note, we don't do this in reverse, because we won't
3028 actually be executing the breakpoint insn anyway.
3029 We'll be (un-)executing the previous instruction. */
3030 tp->stepping_over_breakpoint = 1;
3031 else if (gdbarch_single_step_through_delay_p (gdbarch)
3032 && gdbarch_single_step_through_delay (gdbarch,
3033 get_current_frame ()))
3034 /* We stepped onto an instruction that needs to be stepped
3035 again before re-inserting the breakpoint, do so. */
3036 tp->stepping_over_breakpoint = 1;
3040 regcache_write_pc (regcache, addr);
3043 if (siggnal != GDB_SIGNAL_DEFAULT)
3044 tp->suspend.stop_signal = siggnal;
3046 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3048 /* If an exception is thrown from this point on, make sure to
3049 propagate GDB's knowledge of the executing state to the
3050 frontend/user running state. */
3051 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
3053 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3054 threads (e.g., we might need to set threads stepping over
3055 breakpoints first), from the user/frontend's point of view, all
3056 threads in RESUME_PTID are now running. Unless we're calling an
3057 inferior function, as in that case we pretend the inferior
3058 doesn't run at all. */
3059 if (!tp->control.in_infcall)
3060 set_running (resume_ptid, 1);
3063 fprintf_unfiltered (gdb_stdlog,
3064 "infrun: proceed (addr=%s, signal=%s)\n",
3065 paddress (gdbarch, addr),
3066 gdb_signal_to_symbol_string (siggnal));
3068 annotate_starting ();
3070 /* Make sure that output from GDB appears before output from the
3072 gdb_flush (gdb_stdout);
3074 /* In a multi-threaded task we may select another thread and
3075 then continue or step.
3077 But if a thread that we're resuming had stopped at a breakpoint,
3078 it will immediately cause another breakpoint stop without any
3079 execution (i.e. it will report a breakpoint hit incorrectly). So
3080 we must step over it first.
3082 Look for threads other than the current (TP) that reported a
3083 breakpoint hit and haven't been resumed yet since. */
3085 /* If scheduler locking applies, we can avoid iterating over all
3087 if (!non_stop && !schedlock_applies (tp))
3089 struct thread_info *current = tp;
3091 ALL_NON_EXITED_THREADS (tp)
3093 /* Ignore the current thread here. It's handled
3098 /* Ignore threads of processes we're not resuming. */
3099 if (!ptid_match (tp->ptid, resume_ptid))
3102 if (!thread_still_needs_step_over (tp))
3105 gdb_assert (!thread_is_in_step_over_chain (tp));
3108 fprintf_unfiltered (gdb_stdlog,
3109 "infrun: need to step-over [%s] first\n",
3110 target_pid_to_str (tp->ptid));
3112 thread_step_over_chain_enqueue (tp);
3118 /* Enqueue the current thread last, so that we move all other
3119 threads over their breakpoints first. */
3120 if (tp->stepping_over_breakpoint)
3121 thread_step_over_chain_enqueue (tp);
3123 /* If the thread isn't started, we'll still need to set its prev_pc,
3124 so that switch_back_to_stepped_thread knows the thread hasn't
3125 advanced. Must do this before resuming any thread, as in
3126 all-stop/remote, once we resume we can't send any other packet
3127 until the target stops again. */
3128 tp->prev_pc = regcache_read_pc (regcache);
3131 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
3133 started = start_step_over ();
3135 if (step_over_info_valid_p ())
3137 /* Either this thread started a new in-line step over, or some
3138 other thread was already doing one. In either case, don't
3139 resume anything else until the step-over is finished. */
3141 else if (started && !target_is_non_stop_p ())
3143 /* A new displaced stepping sequence was started. In all-stop,
3144 we can't talk to the target anymore until it next stops. */
3146 else if (!non_stop && target_is_non_stop_p ())
3148 /* In all-stop, but the target is always in non-stop mode.
3149 Start all other threads that are implicitly resumed too. */
3150 ALL_NON_EXITED_THREADS (tp)
3152 /* Ignore threads of processes we're not resuming. */
3153 if (!ptid_match (tp->ptid, resume_ptid))
3159 fprintf_unfiltered (gdb_stdlog,
3160 "infrun: proceed: [%s] resumed\n",
3161 target_pid_to_str (tp->ptid));
3162 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3166 if (thread_is_in_step_over_chain (tp))
3169 fprintf_unfiltered (gdb_stdlog,
3170 "infrun: proceed: [%s] needs step-over\n",
3171 target_pid_to_str (tp->ptid));
3176 fprintf_unfiltered (gdb_stdlog,
3177 "infrun: proceed: resuming %s\n",
3178 target_pid_to_str (tp->ptid));
3180 reset_ecs (ecs, tp);
3181 switch_to_thread (tp->ptid);
3182 keep_going_pass_signal (ecs);
3183 if (!ecs->wait_some_more)
3184 error (_("Command aborted."));
3187 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3189 /* The thread wasn't started, and isn't queued, run it now. */
3190 reset_ecs (ecs, tp);
3191 switch_to_thread (tp->ptid);
3192 keep_going_pass_signal (ecs);
3193 if (!ecs->wait_some_more)
3194 error (_("Command aborted."));
3198 target_commit_resume ();
3200 discard_cleanups (old_chain);
3202 /* Tell the event loop to wait for it to stop. If the target
3203 supports asynchronous execution, it'll do this from within
3205 if (!target_can_async_p ())
3206 mark_async_event_handler (infrun_async_inferior_event_token);
3210 /* Start remote-debugging of a machine over a serial link. */
3213 start_remote (int from_tty)
3215 struct inferior *inferior;
3217 inferior = current_inferior ();
3218 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3220 /* Always go on waiting for the target, regardless of the mode. */
3221 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3222 indicate to wait_for_inferior that a target should timeout if
3223 nothing is returned (instead of just blocking). Because of this,
3224 targets expecting an immediate response need to, internally, set
3225 things up so that the target_wait() is forced to eventually
3227 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3228 differentiate to its caller what the state of the target is after
3229 the initial open has been performed. Here we're assuming that
3230 the target has stopped. It should be possible to eventually have
3231 target_open() return to the caller an indication that the target
3232 is currently running and GDB state should be set to the same as
3233 for an async run. */
3234 wait_for_inferior ();
3236 /* Now that the inferior has stopped, do any bookkeeping like
3237 loading shared libraries. We want to do this before normal_stop,
3238 so that the displayed frame is up to date. */
3239 post_create_inferior (¤t_target, from_tty);
3244 /* Initialize static vars when a new inferior begins. */
3247 init_wait_for_inferior (void)
3249 /* These are meaningless until the first time through wait_for_inferior. */
3251 breakpoint_init_inferior (inf_starting);
3253 clear_proceed_status (0);
3255 target_last_wait_ptid = minus_one_ptid;
3257 previous_inferior_ptid = inferior_ptid;
3259 /* Discard any skipped inlined frames. */
3260 clear_inline_frame_state (minus_one_ptid);
3265 static void handle_inferior_event (struct execution_control_state *ecs);
3267 static void handle_step_into_function (struct gdbarch *gdbarch,
3268 struct execution_control_state *ecs);
3269 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3270 struct execution_control_state *ecs);
3271 static void handle_signal_stop (struct execution_control_state *ecs);
3272 static void check_exception_resume (struct execution_control_state *,
3273 struct frame_info *);
3275 static void end_stepping_range (struct execution_control_state *ecs);
3276 static void stop_waiting (struct execution_control_state *ecs);
3277 static void keep_going (struct execution_control_state *ecs);
3278 static void process_event_stop_test (struct execution_control_state *ecs);
3279 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3281 /* This function is attached as a "thread_stop_requested" observer.
3282 Cleanup local state that assumed the PTID was to be resumed, and
3283 report the stop to the frontend. */
3286 infrun_thread_stop_requested (ptid_t ptid)
3288 struct thread_info *tp;
3290 /* PTID was requested to stop. If the thread was already stopped,
3291 but the user/frontend doesn't know about that yet (e.g., the
3292 thread had been temporarily paused for some step-over), set up
3293 for reporting the stop now. */
3294 ALL_NON_EXITED_THREADS (tp)
3295 if (ptid_match (tp->ptid, ptid))
3297 if (tp->state != THREAD_RUNNING)
3302 /* Remove matching threads from the step-over queue, so
3303 start_step_over doesn't try to resume them
3305 if (thread_is_in_step_over_chain (tp))
3306 thread_step_over_chain_remove (tp);
3308 /* If the thread is stopped, but the user/frontend doesn't
3309 know about that yet, queue a pending event, as if the
3310 thread had just stopped now. Unless the thread already had
3312 if (!tp->suspend.waitstatus_pending_p)
3314 tp->suspend.waitstatus_pending_p = 1;
3315 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3316 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3319 /* Clear the inline-frame state, since we're re-processing the
3321 clear_inline_frame_state (tp->ptid);
3323 /* If this thread was paused because some other thread was
3324 doing an inline-step over, let that finish first. Once
3325 that happens, we'll restart all threads and consume pending
3326 stop events then. */
3327 if (step_over_info_valid_p ())
3330 /* Otherwise we can process the (new) pending event now. Set
3331 it so this pending event is considered by
3338 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3340 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3341 nullify_last_target_wait_ptid ();
3344 /* Delete the step resume, single-step and longjmp/exception resume
3345 breakpoints of TP. */
3348 delete_thread_infrun_breakpoints (struct thread_info *tp)
3350 delete_step_resume_breakpoint (tp);
3351 delete_exception_resume_breakpoint (tp);
3352 delete_single_step_breakpoints (tp);
3355 /* If the target still has execution, call FUNC for each thread that
3356 just stopped. In all-stop, that's all the non-exited threads; in
3357 non-stop, that's the current thread, only. */
3359 typedef void (*for_each_just_stopped_thread_callback_func)
3360 (struct thread_info *tp);
3363 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3365 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3368 if (target_is_non_stop_p ())
3370 /* If in non-stop mode, only the current thread stopped. */
3371 func (inferior_thread ());
3375 struct thread_info *tp;
3377 /* In all-stop mode, all threads have stopped. */
3378 ALL_NON_EXITED_THREADS (tp)
3385 /* Delete the step resume and longjmp/exception resume breakpoints of
3386 the threads that just stopped. */
3389 delete_just_stopped_threads_infrun_breakpoints (void)
3391 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3394 /* Delete the single-step breakpoints of the threads that just
3398 delete_just_stopped_threads_single_step_breakpoints (void)
3400 for_each_just_stopped_thread (delete_single_step_breakpoints);
3403 /* A cleanup wrapper. */
3406 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3408 delete_just_stopped_threads_infrun_breakpoints ();
3414 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3415 const struct target_waitstatus *ws)
3417 std::string status_string = target_waitstatus_to_string (ws);
3420 /* The text is split over several lines because it was getting too long.
3421 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3422 output as a unit; we want only one timestamp printed if debug_timestamp
3425 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3426 ptid_get_pid (waiton_ptid),
3427 ptid_get_lwp (waiton_ptid),
3428 ptid_get_tid (waiton_ptid));
3429 if (ptid_get_pid (waiton_ptid) != -1)
3430 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3431 stb.printf (", status) =\n");
3432 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3433 ptid_get_pid (result_ptid),
3434 ptid_get_lwp (result_ptid),
3435 ptid_get_tid (result_ptid),
3436 target_pid_to_str (result_ptid));
3437 stb.printf ("infrun: %s\n", status_string.c_str ());
3439 /* This uses %s in part to handle %'s in the text, but also to avoid
3440 a gcc error: the format attribute requires a string literal. */
3441 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3444 /* Select a thread at random, out of those which are resumed and have
3447 static struct thread_info *
3448 random_pending_event_thread (ptid_t waiton_ptid)
3450 struct thread_info *event_tp;
3452 int random_selector;
3454 /* First see how many events we have. Count only resumed threads
3455 that have an event pending. */
3456 ALL_NON_EXITED_THREADS (event_tp)
3457 if (ptid_match (event_tp->ptid, waiton_ptid)
3458 && event_tp->resumed
3459 && event_tp->suspend.waitstatus_pending_p)
3462 if (num_events == 0)
3465 /* Now randomly pick a thread out of those that have had events. */
3466 random_selector = (int)
3467 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3469 if (debug_infrun && num_events > 1)
3470 fprintf_unfiltered (gdb_stdlog,
3471 "infrun: Found %d events, selecting #%d\n",
3472 num_events, random_selector);
3474 /* Select the Nth thread that has had an event. */
3475 ALL_NON_EXITED_THREADS (event_tp)
3476 if (ptid_match (event_tp->ptid, waiton_ptid)
3477 && event_tp->resumed
3478 && event_tp->suspend.waitstatus_pending_p)
3479 if (random_selector-- == 0)
3485 /* Wrapper for target_wait that first checks whether threads have
3486 pending statuses to report before actually asking the target for
3490 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3493 struct thread_info *tp;
3495 /* First check if there is a resumed thread with a wait status
3497 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3499 tp = random_pending_event_thread (ptid);
3504 fprintf_unfiltered (gdb_stdlog,
3505 "infrun: Waiting for specific thread %s.\n",
3506 target_pid_to_str (ptid));
3508 /* We have a specific thread to check. */
3509 tp = find_thread_ptid (ptid);
3510 gdb_assert (tp != NULL);
3511 if (!tp->suspend.waitstatus_pending_p)
3516 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3517 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3519 struct regcache *regcache = get_thread_regcache (tp->ptid);
3520 struct gdbarch *gdbarch = regcache->arch ();
3524 pc = regcache_read_pc (regcache);
3526 if (pc != tp->suspend.stop_pc)
3529 fprintf_unfiltered (gdb_stdlog,
3530 "infrun: PC of %s changed. was=%s, now=%s\n",
3531 target_pid_to_str (tp->ptid),
3532 paddress (gdbarch, tp->prev_pc),
3533 paddress (gdbarch, pc));
3536 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3539 fprintf_unfiltered (gdb_stdlog,
3540 "infrun: previous breakpoint of %s, at %s gone\n",
3541 target_pid_to_str (tp->ptid),
3542 paddress (gdbarch, pc));
3550 fprintf_unfiltered (gdb_stdlog,
3551 "infrun: pending event of %s cancelled.\n",
3552 target_pid_to_str (tp->ptid));
3554 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3555 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3564 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3566 fprintf_unfiltered (gdb_stdlog,
3567 "infrun: Using pending wait status %s for %s.\n",
3569 target_pid_to_str (tp->ptid));
3572 /* Now that we've selected our final event LWP, un-adjust its PC
3573 if it was a software breakpoint (and the target doesn't
3574 always adjust the PC itself). */
3575 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3576 && !target_supports_stopped_by_sw_breakpoint ())
3578 struct regcache *regcache;
3579 struct gdbarch *gdbarch;
3582 regcache = get_thread_regcache (tp->ptid);
3583 gdbarch = regcache->arch ();
3585 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3590 pc = regcache_read_pc (regcache);
3591 regcache_write_pc (regcache, pc + decr_pc);
3595 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3596 *status = tp->suspend.waitstatus;
3597 tp->suspend.waitstatus_pending_p = 0;
3599 /* Wake up the event loop again, until all pending events are
3601 if (target_is_async_p ())
3602 mark_async_event_handler (infrun_async_inferior_event_token);
3606 /* But if we don't find one, we'll have to wait. */
3608 if (deprecated_target_wait_hook)
3609 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3611 event_ptid = target_wait (ptid, status, options);
3616 /* Prepare and stabilize the inferior for detaching it. E.g.,
3617 detaching while a thread is displaced stepping is a recipe for
3618 crashing it, as nothing would readjust the PC out of the scratch
3622 prepare_for_detach (void)
3624 struct inferior *inf = current_inferior ();
3625 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3626 struct displaced_step_inferior_state *displaced;
3628 displaced = get_displaced_stepping_state (inf->pid);
3630 /* Is any thread of this process displaced stepping? If not,
3631 there's nothing else to do. */
3632 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3636 fprintf_unfiltered (gdb_stdlog,
3637 "displaced-stepping in-process while detaching");
3639 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3641 while (!ptid_equal (displaced->step_ptid, null_ptid))
3643 struct cleanup *old_chain_2;
3644 struct execution_control_state ecss;
3645 struct execution_control_state *ecs;
3648 memset (ecs, 0, sizeof (*ecs));
3650 overlay_cache_invalid = 1;
3651 /* Flush target cache before starting to handle each event.
3652 Target was running and cache could be stale. This is just a
3653 heuristic. Running threads may modify target memory, but we
3654 don't get any event. */
3655 target_dcache_invalidate ();
3657 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3660 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3662 /* If an error happens while handling the event, propagate GDB's
3663 knowledge of the executing state to the frontend/user running
3665 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3668 /* Now figure out what to do with the result of the result. */
3669 handle_inferior_event (ecs);
3671 /* No error, don't finish the state yet. */
3672 discard_cleanups (old_chain_2);
3674 /* Breakpoints and watchpoints are not installed on the target
3675 at this point, and signals are passed directly to the
3676 inferior, so this must mean the process is gone. */
3677 if (!ecs->wait_some_more)
3679 restore_detaching.release ();
3680 error (_("Program exited while detaching"));
3684 restore_detaching.release ();
3687 /* Wait for control to return from inferior to debugger.
3689 If inferior gets a signal, we may decide to start it up again
3690 instead of returning. That is why there is a loop in this function.
3691 When this function actually returns it means the inferior
3692 should be left stopped and GDB should read more commands. */
3695 wait_for_inferior (void)
3697 struct cleanup *old_cleanups;
3698 struct cleanup *thread_state_chain;
3702 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3705 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3708 /* If an error happens while handling the event, propagate GDB's
3709 knowledge of the executing state to the frontend/user running
3711 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3715 struct execution_control_state ecss;
3716 struct execution_control_state *ecs = &ecss;
3717 ptid_t waiton_ptid = minus_one_ptid;
3719 memset (ecs, 0, sizeof (*ecs));
3721 overlay_cache_invalid = 1;
3723 /* Flush target cache before starting to handle each event.
3724 Target was running and cache could be stale. This is just a
3725 heuristic. Running threads may modify target memory, but we
3726 don't get any event. */
3727 target_dcache_invalidate ();
3729 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3732 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3734 /* Now figure out what to do with the result of the result. */
3735 handle_inferior_event (ecs);
3737 if (!ecs->wait_some_more)
3741 /* No error, don't finish the state yet. */
3742 discard_cleanups (thread_state_chain);
3744 do_cleanups (old_cleanups);
3747 /* Cleanup that reinstalls the readline callback handler, if the
3748 target is running in the background. If while handling the target
3749 event something triggered a secondary prompt, like e.g., a
3750 pagination prompt, we'll have removed the callback handler (see
3751 gdb_readline_wrapper_line). Need to do this as we go back to the
3752 event loop, ready to process further input. Note this has no
3753 effect if the handler hasn't actually been removed, because calling
3754 rl_callback_handler_install resets the line buffer, thus losing
3758 reinstall_readline_callback_handler_cleanup (void *arg)
3760 struct ui *ui = current_ui;
3764 /* We're not going back to the top level event loop yet. Don't
3765 install the readline callback, as it'd prep the terminal,
3766 readline-style (raw, noecho) (e.g., --batch). We'll install
3767 it the next time the prompt is displayed, when we're ready
3772 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3773 gdb_rl_callback_handler_reinstall ();
3776 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3777 that's just the event thread. In all-stop, that's all threads. */
3780 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3782 struct thread_info *thr = ecs->event_thread;
3784 if (thr != NULL && thr->thread_fsm != NULL)
3785 thread_fsm_clean_up (thr->thread_fsm, thr);
3789 ALL_NON_EXITED_THREADS (thr)
3791 if (thr->thread_fsm == NULL)
3793 if (thr == ecs->event_thread)
3796 switch_to_thread (thr->ptid);
3797 thread_fsm_clean_up (thr->thread_fsm, thr);
3800 if (ecs->event_thread != NULL)
3801 switch_to_thread (ecs->event_thread->ptid);
3805 /* Helper for all_uis_check_sync_execution_done that works on the
3809 check_curr_ui_sync_execution_done (void)
3811 struct ui *ui = current_ui;
3813 if (ui->prompt_state == PROMPT_NEEDED
3815 && !gdb_in_secondary_prompt_p (ui))
3817 target_terminal::ours ();
3818 observer_notify_sync_execution_done ();
3819 ui_register_input_event_handler (ui);
3826 all_uis_check_sync_execution_done (void)
3828 SWITCH_THRU_ALL_UIS ()
3830 check_curr_ui_sync_execution_done ();
3837 all_uis_on_sync_execution_starting (void)
3839 SWITCH_THRU_ALL_UIS ()
3841 if (current_ui->prompt_state == PROMPT_NEEDED)
3842 async_disable_stdin ();
3846 /* Asynchronous version of wait_for_inferior. It is called by the
3847 event loop whenever a change of state is detected on the file
3848 descriptor corresponding to the target. It can be called more than
3849 once to complete a single execution command. In such cases we need
3850 to keep the state in a global variable ECSS. If it is the last time
3851 that this function is called for a single execution command, then
3852 report to the user that the inferior has stopped, and do the
3853 necessary cleanups. */
3856 fetch_inferior_event (void *client_data)
3858 struct execution_control_state ecss;
3859 struct execution_control_state *ecs = &ecss;
3860 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3861 struct cleanup *ts_old_chain;
3863 ptid_t waiton_ptid = minus_one_ptid;
3865 memset (ecs, 0, sizeof (*ecs));
3867 /* Events are always processed with the main UI as current UI. This
3868 way, warnings, debug output, etc. are always consistently sent to
3869 the main console. */
3870 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3872 /* End up with readline processing input, if necessary. */
3873 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3875 /* We're handling a live event, so make sure we're doing live
3876 debugging. If we're looking at traceframes while the target is
3877 running, we're going to need to get back to that mode after
3878 handling the event. */
3881 make_cleanup_restore_current_traceframe ();
3882 set_current_traceframe (-1);
3885 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3888 /* In non-stop mode, the user/frontend should not notice a thread
3889 switch due to internal events. Make sure we reverse to the
3890 user selected thread and frame after handling the event and
3891 running any breakpoint commands. */
3892 maybe_restore_thread.emplace ();
3894 overlay_cache_invalid = 1;
3895 /* Flush target cache before starting to handle each event. Target
3896 was running and cache could be stale. This is just a heuristic.
3897 Running threads may modify target memory, but we don't get any
3899 target_dcache_invalidate ();
3901 scoped_restore save_exec_dir
3902 = make_scoped_restore (&execution_direction, target_execution_direction ());
3904 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3905 target_can_async_p () ? TARGET_WNOHANG : 0);
3908 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3910 /* If an error happens while handling the event, propagate GDB's
3911 knowledge of the executing state to the frontend/user running
3913 if (!target_is_non_stop_p ())
3914 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3916 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3918 /* Get executed before make_cleanup_restore_current_thread above to apply
3919 still for the thread which has thrown the exception. */
3920 make_bpstat_clear_actions_cleanup ();
3922 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3924 /* Now figure out what to do with the result of the result. */
3925 handle_inferior_event (ecs);
3927 if (!ecs->wait_some_more)
3929 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3930 int should_stop = 1;
3931 struct thread_info *thr = ecs->event_thread;
3932 int should_notify_stop = 1;
3934 delete_just_stopped_threads_infrun_breakpoints ();
3938 struct thread_fsm *thread_fsm = thr->thread_fsm;
3940 if (thread_fsm != NULL)
3941 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3950 clean_up_just_stopped_threads_fsms (ecs);
3952 if (thr != NULL && thr->thread_fsm != NULL)
3955 = thread_fsm_should_notify_stop (thr->thread_fsm);
3958 if (should_notify_stop)
3962 /* We may not find an inferior if this was a process exit. */
3963 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3964 proceeded = normal_stop ();
3968 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3975 /* No error, don't finish the thread states yet. */
3976 discard_cleanups (ts_old_chain);
3978 /* Revert thread and frame. */
3979 do_cleanups (old_chain);
3981 /* If a UI was in sync execution mode, and now isn't, restore its
3982 prompt (a synchronous execution command has finished, and we're
3983 ready for input). */
3984 all_uis_check_sync_execution_done ();
3987 && exec_done_display_p
3988 && (ptid_equal (inferior_ptid, null_ptid)
3989 || !is_running (inferior_ptid)))
3990 printf_unfiltered (_("completed.\n"));
3993 /* Record the frame and location we're currently stepping through. */
3995 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3997 struct thread_info *tp = inferior_thread ();
3999 tp->control.step_frame_id = get_frame_id (frame);
4000 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
4002 tp->current_symtab = sal.symtab;
4003 tp->current_line = sal.line;
4006 /* Clear context switchable stepping state. */
4009 init_thread_stepping_state (struct thread_info *tss)
4011 tss->stepped_breakpoint = 0;
4012 tss->stepping_over_breakpoint = 0;
4013 tss->stepping_over_watchpoint = 0;
4014 tss->step_after_step_resume_breakpoint = 0;
4017 /* Set the cached copy of the last ptid/waitstatus. */
4020 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4022 target_last_wait_ptid = ptid;
4023 target_last_waitstatus = status;
4026 /* Return the cached copy of the last pid/waitstatus returned by
4027 target_wait()/deprecated_target_wait_hook(). The data is actually
4028 cached by handle_inferior_event(), which gets called immediately
4029 after target_wait()/deprecated_target_wait_hook(). */
4032 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4034 *ptidp = target_last_wait_ptid;
4035 *status = target_last_waitstatus;
4039 nullify_last_target_wait_ptid (void)
4041 target_last_wait_ptid = minus_one_ptid;
4044 /* Switch thread contexts. */
4047 context_switch (ptid_t ptid)
4049 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4051 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4052 target_pid_to_str (inferior_ptid));
4053 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4054 target_pid_to_str (ptid));
4057 switch_to_thread (ptid);
4060 /* If the target can't tell whether we've hit breakpoints
4061 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4062 check whether that could have been caused by a breakpoint. If so,
4063 adjust the PC, per gdbarch_decr_pc_after_break. */
4066 adjust_pc_after_break (struct thread_info *thread,
4067 struct target_waitstatus *ws)
4069 struct regcache *regcache;
4070 struct gdbarch *gdbarch;
4071 CORE_ADDR breakpoint_pc, decr_pc;
4073 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4074 we aren't, just return.
4076 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4077 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4078 implemented by software breakpoints should be handled through the normal
4081 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4082 different signals (SIGILL or SIGEMT for instance), but it is less
4083 clear where the PC is pointing afterwards. It may not match
4084 gdbarch_decr_pc_after_break. I don't know any specific target that
4085 generates these signals at breakpoints (the code has been in GDB since at
4086 least 1992) so I can not guess how to handle them here.
4088 In earlier versions of GDB, a target with
4089 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4090 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4091 target with both of these set in GDB history, and it seems unlikely to be
4092 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4094 if (ws->kind != TARGET_WAITKIND_STOPPED)
4097 if (ws->value.sig != GDB_SIGNAL_TRAP)
4100 /* In reverse execution, when a breakpoint is hit, the instruction
4101 under it has already been de-executed. The reported PC always
4102 points at the breakpoint address, so adjusting it further would
4103 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4106 B1 0x08000000 : INSN1
4107 B2 0x08000001 : INSN2
4109 PC -> 0x08000003 : INSN4
4111 Say you're stopped at 0x08000003 as above. Reverse continuing
4112 from that point should hit B2 as below. Reading the PC when the
4113 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4114 been de-executed already.
4116 B1 0x08000000 : INSN1
4117 B2 PC -> 0x08000001 : INSN2
4121 We can't apply the same logic as for forward execution, because
4122 we would wrongly adjust the PC to 0x08000000, since there's a
4123 breakpoint at PC - 1. We'd then report a hit on B1, although
4124 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4126 if (execution_direction == EXEC_REVERSE)
4129 /* If the target can tell whether the thread hit a SW breakpoint,
4130 trust it. Targets that can tell also adjust the PC
4132 if (target_supports_stopped_by_sw_breakpoint ())
4135 /* Note that relying on whether a breakpoint is planted in memory to
4136 determine this can fail. E.g,. the breakpoint could have been
4137 removed since. Or the thread could have been told to step an
4138 instruction the size of a breakpoint instruction, and only
4139 _after_ was a breakpoint inserted at its address. */
4141 /* If this target does not decrement the PC after breakpoints, then
4142 we have nothing to do. */
4143 regcache = get_thread_regcache (thread->ptid);
4144 gdbarch = regcache->arch ();
4146 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4150 const address_space *aspace = regcache->aspace ();
4152 /* Find the location where (if we've hit a breakpoint) the
4153 breakpoint would be. */
4154 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4156 /* If the target can't tell whether a software breakpoint triggered,
4157 fallback to figuring it out based on breakpoints we think were
4158 inserted in the target, and on whether the thread was stepped or
4161 /* Check whether there actually is a software breakpoint inserted at
4164 If in non-stop mode, a race condition is possible where we've
4165 removed a breakpoint, but stop events for that breakpoint were
4166 already queued and arrive later. To suppress those spurious
4167 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4168 and retire them after a number of stop events are reported. Note
4169 this is an heuristic and can thus get confused. The real fix is
4170 to get the "stopped by SW BP and needs adjustment" info out of
4171 the target/kernel (and thus never reach here; see above). */
4172 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4173 || (target_is_non_stop_p ()
4174 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4176 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4178 if (record_full_is_used ())
4179 restore_operation_disable.emplace
4180 (record_full_gdb_operation_disable_set ());
4182 /* When using hardware single-step, a SIGTRAP is reported for both
4183 a completed single-step and a software breakpoint. Need to
4184 differentiate between the two, as the latter needs adjusting
4185 but the former does not.
4187 The SIGTRAP can be due to a completed hardware single-step only if
4188 - we didn't insert software single-step breakpoints
4189 - this thread is currently being stepped
4191 If any of these events did not occur, we must have stopped due
4192 to hitting a software breakpoint, and have to back up to the
4195 As a special case, we could have hardware single-stepped a
4196 software breakpoint. In this case (prev_pc == breakpoint_pc),
4197 we also need to back up to the breakpoint address. */
4199 if (thread_has_single_step_breakpoints_set (thread)
4200 || !currently_stepping (thread)
4201 || (thread->stepped_breakpoint
4202 && thread->prev_pc == breakpoint_pc))
4203 regcache_write_pc (regcache, breakpoint_pc);
4208 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4210 for (frame = get_prev_frame (frame);
4212 frame = get_prev_frame (frame))
4214 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4216 if (get_frame_type (frame) != INLINE_FRAME)
4223 /* If the event thread has the stop requested flag set, pretend it
4224 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4228 handle_stop_requested (struct execution_control_state *ecs)
4230 if (ecs->event_thread->stop_requested)
4232 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4233 ecs->ws.value.sig = GDB_SIGNAL_0;
4234 handle_signal_stop (ecs);
4240 /* Auxiliary function that handles syscall entry/return events.
4241 It returns 1 if the inferior should keep going (and GDB
4242 should ignore the event), or 0 if the event deserves to be
4246 handle_syscall_event (struct execution_control_state *ecs)
4248 struct regcache *regcache;
4251 if (!ptid_equal (ecs->ptid, inferior_ptid))
4252 context_switch (ecs->ptid);
4254 regcache = get_thread_regcache (ecs->ptid);
4255 syscall_number = ecs->ws.value.syscall_number;
4256 stop_pc = regcache_read_pc (regcache);
4258 if (catch_syscall_enabled () > 0
4259 && catching_syscall_number (syscall_number) > 0)
4262 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4265 ecs->event_thread->control.stop_bpstat
4266 = bpstat_stop_status (regcache->aspace (),
4267 stop_pc, ecs->ptid, &ecs->ws);
4269 if (handle_stop_requested (ecs))
4272 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4274 /* Catchpoint hit. */
4279 if (handle_stop_requested (ecs))
4282 /* If no catchpoint triggered for this, then keep going. */
4287 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4290 fill_in_stop_func (struct gdbarch *gdbarch,
4291 struct execution_control_state *ecs)
4293 if (!ecs->stop_func_filled_in)
4295 /* Don't care about return value; stop_func_start and stop_func_name
4296 will both be 0 if it doesn't work. */
4297 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4298 &ecs->stop_func_start, &ecs->stop_func_end);
4299 ecs->stop_func_start
4300 += gdbarch_deprecated_function_start_offset (gdbarch);
4302 if (gdbarch_skip_entrypoint_p (gdbarch))
4303 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4304 ecs->stop_func_start);
4306 ecs->stop_func_filled_in = 1;
4311 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4313 static enum stop_kind
4314 get_inferior_stop_soon (ptid_t ptid)
4316 struct inferior *inf = find_inferior_ptid (ptid);
4318 gdb_assert (inf != NULL);
4319 return inf->control.stop_soon;
4322 /* Wait for one event. Store the resulting waitstatus in WS, and
4323 return the event ptid. */
4326 wait_one (struct target_waitstatus *ws)
4329 ptid_t wait_ptid = minus_one_ptid;
4331 overlay_cache_invalid = 1;
4333 /* Flush target cache before starting to handle each event.
4334 Target was running and cache could be stale. This is just a
4335 heuristic. Running threads may modify target memory, but we
4336 don't get any event. */
4337 target_dcache_invalidate ();
4339 if (deprecated_target_wait_hook)
4340 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4342 event_ptid = target_wait (wait_ptid, ws, 0);
4345 print_target_wait_results (wait_ptid, event_ptid, ws);
4350 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4351 instead of the current thread. */
4352 #define THREAD_STOPPED_BY(REASON) \
4354 thread_stopped_by_ ## REASON (ptid_t ptid) \
4356 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4357 inferior_ptid = ptid; \
4359 return target_stopped_by_ ## REASON (); \
4362 /* Generate thread_stopped_by_watchpoint. */
4363 THREAD_STOPPED_BY (watchpoint)
4364 /* Generate thread_stopped_by_sw_breakpoint. */
4365 THREAD_STOPPED_BY (sw_breakpoint)
4366 /* Generate thread_stopped_by_hw_breakpoint. */
4367 THREAD_STOPPED_BY (hw_breakpoint)
4369 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4372 switch_to_thread_cleanup (void *ptid_p)
4374 ptid_t ptid = *(ptid_t *) ptid_p;
4376 switch_to_thread (ptid);
4379 /* Save the thread's event and stop reason to process it later. */
4382 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4384 struct regcache *regcache;
4388 std::string statstr = target_waitstatus_to_string (ws);
4390 fprintf_unfiltered (gdb_stdlog,
4391 "infrun: saving status %s for %d.%ld.%ld\n",
4393 ptid_get_pid (tp->ptid),
4394 ptid_get_lwp (tp->ptid),
4395 ptid_get_tid (tp->ptid));
4398 /* Record for later. */
4399 tp->suspend.waitstatus = *ws;
4400 tp->suspend.waitstatus_pending_p = 1;
4402 regcache = get_thread_regcache (tp->ptid);
4403 const address_space *aspace = regcache->aspace ();
4405 if (ws->kind == TARGET_WAITKIND_STOPPED
4406 && ws->value.sig == GDB_SIGNAL_TRAP)
4408 CORE_ADDR pc = regcache_read_pc (regcache);
4410 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4412 if (thread_stopped_by_watchpoint (tp->ptid))
4414 tp->suspend.stop_reason
4415 = TARGET_STOPPED_BY_WATCHPOINT;
4417 else if (target_supports_stopped_by_sw_breakpoint ()
4418 && thread_stopped_by_sw_breakpoint (tp->ptid))
4420 tp->suspend.stop_reason
4421 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4423 else if (target_supports_stopped_by_hw_breakpoint ()
4424 && thread_stopped_by_hw_breakpoint (tp->ptid))
4426 tp->suspend.stop_reason
4427 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4429 else if (!target_supports_stopped_by_hw_breakpoint ()
4430 && hardware_breakpoint_inserted_here_p (aspace,
4433 tp->suspend.stop_reason
4434 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4436 else if (!target_supports_stopped_by_sw_breakpoint ()
4437 && software_breakpoint_inserted_here_p (aspace,
4440 tp->suspend.stop_reason
4441 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4443 else if (!thread_has_single_step_breakpoints_set (tp)
4444 && currently_stepping (tp))
4446 tp->suspend.stop_reason
4447 = TARGET_STOPPED_BY_SINGLE_STEP;
4452 /* A cleanup that disables thread create/exit events. */
4455 disable_thread_events (void *arg)
4457 target_thread_events (0);
4463 stop_all_threads (void)
4465 /* We may need multiple passes to discover all threads. */
4469 struct cleanup *old_chain;
4471 gdb_assert (target_is_non_stop_p ());
4474 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4476 entry_ptid = inferior_ptid;
4477 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4479 target_thread_events (1);
4480 make_cleanup (disable_thread_events, NULL);
4482 /* Request threads to stop, and then wait for the stops. Because
4483 threads we already know about can spawn more threads while we're
4484 trying to stop them, and we only learn about new threads when we
4485 update the thread list, do this in a loop, and keep iterating
4486 until two passes find no threads that need to be stopped. */
4487 for (pass = 0; pass < 2; pass++, iterations++)
4490 fprintf_unfiltered (gdb_stdlog,
4491 "infrun: stop_all_threads, pass=%d, "
4492 "iterations=%d\n", pass, iterations);
4496 struct target_waitstatus ws;
4498 struct thread_info *t;
4500 update_thread_list ();
4502 /* Go through all threads looking for threads that we need
4503 to tell the target to stop. */
4504 ALL_NON_EXITED_THREADS (t)
4508 /* If already stopping, don't request a stop again.
4509 We just haven't seen the notification yet. */
4510 if (!t->stop_requested)
4513 fprintf_unfiltered (gdb_stdlog,
4514 "infrun: %s executing, "
4516 target_pid_to_str (t->ptid));
4517 target_stop (t->ptid);
4518 t->stop_requested = 1;
4523 fprintf_unfiltered (gdb_stdlog,
4524 "infrun: %s executing, "
4525 "already stopping\n",
4526 target_pid_to_str (t->ptid));
4529 if (t->stop_requested)
4535 fprintf_unfiltered (gdb_stdlog,
4536 "infrun: %s not executing\n",
4537 target_pid_to_str (t->ptid));
4539 /* The thread may be not executing, but still be
4540 resumed with a pending status to process. */
4548 /* If we find new threads on the second iteration, restart
4549 over. We want to see two iterations in a row with all
4554 event_ptid = wait_one (&ws);
4555 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4557 /* All resumed threads exited. */
4559 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4560 || ws.kind == TARGET_WAITKIND_EXITED
4561 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4565 ptid_t ptid = pid_to_ptid (ws.value.integer);
4567 fprintf_unfiltered (gdb_stdlog,
4568 "infrun: %s exited while "
4569 "stopping threads\n",
4570 target_pid_to_str (ptid));
4575 struct inferior *inf;
4577 t = find_thread_ptid (event_ptid);
4579 t = add_thread (event_ptid);
4581 t->stop_requested = 0;
4584 t->control.may_range_step = 0;
4586 /* This may be the first time we see the inferior report
4588 inf = find_inferior_ptid (event_ptid);
4589 if (inf->needs_setup)
4591 switch_to_thread_no_regs (t);
4595 if (ws.kind == TARGET_WAITKIND_STOPPED
4596 && ws.value.sig == GDB_SIGNAL_0)
4598 /* We caught the event that we intended to catch, so
4599 there's no event pending. */
4600 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4601 t->suspend.waitstatus_pending_p = 0;
4603 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4605 /* Add it back to the step-over queue. */
4608 fprintf_unfiltered (gdb_stdlog,
4609 "infrun: displaced-step of %s "
4610 "canceled: adding back to the "
4611 "step-over queue\n",
4612 target_pid_to_str (t->ptid));
4614 t->control.trap_expected = 0;
4615 thread_step_over_chain_enqueue (t);
4620 enum gdb_signal sig;
4621 struct regcache *regcache;
4625 std::string statstr = target_waitstatus_to_string (&ws);
4627 fprintf_unfiltered (gdb_stdlog,
4628 "infrun: target_wait %s, saving "
4629 "status for %d.%ld.%ld\n",
4631 ptid_get_pid (t->ptid),
4632 ptid_get_lwp (t->ptid),
4633 ptid_get_tid (t->ptid));
4636 /* Record for later. */
4637 save_waitstatus (t, &ws);
4639 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4640 ? ws.value.sig : GDB_SIGNAL_0);
4642 if (displaced_step_fixup (t->ptid, sig) < 0)
4644 /* Add it back to the step-over queue. */
4645 t->control.trap_expected = 0;
4646 thread_step_over_chain_enqueue (t);
4649 regcache = get_thread_regcache (t->ptid);
4650 t->suspend.stop_pc = regcache_read_pc (regcache);
4654 fprintf_unfiltered (gdb_stdlog,
4655 "infrun: saved stop_pc=%s for %s "
4656 "(currently_stepping=%d)\n",
4657 paddress (target_gdbarch (),
4658 t->suspend.stop_pc),
4659 target_pid_to_str (t->ptid),
4660 currently_stepping (t));
4667 do_cleanups (old_chain);
4670 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4673 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4676 handle_no_resumed (struct execution_control_state *ecs)
4678 struct inferior *inf;
4679 struct thread_info *thread;
4681 if (target_can_async_p ())
4688 if (ui->prompt_state == PROMPT_BLOCKED)
4696 /* There were no unwaited-for children left in the target, but,
4697 we're not synchronously waiting for events either. Just
4701 fprintf_unfiltered (gdb_stdlog,
4702 "infrun: TARGET_WAITKIND_NO_RESUMED "
4703 "(ignoring: bg)\n");
4704 prepare_to_wait (ecs);
4709 /* Otherwise, if we were running a synchronous execution command, we
4710 may need to cancel it and give the user back the terminal.
4712 In non-stop mode, the target can't tell whether we've already
4713 consumed previous stop events, so it can end up sending us a
4714 no-resumed event like so:
4716 #0 - thread 1 is left stopped
4718 #1 - thread 2 is resumed and hits breakpoint
4719 -> TARGET_WAITKIND_STOPPED
4721 #2 - thread 3 is resumed and exits
4722 this is the last resumed thread, so
4723 -> TARGET_WAITKIND_NO_RESUMED
4725 #3 - gdb processes stop for thread 2 and decides to re-resume
4728 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4729 thread 2 is now resumed, so the event should be ignored.
4731 IOW, if the stop for thread 2 doesn't end a foreground command,
4732 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4733 event. But it could be that the event meant that thread 2 itself
4734 (or whatever other thread was the last resumed thread) exited.
4736 To address this we refresh the thread list and check whether we
4737 have resumed threads _now_. In the example above, this removes
4738 thread 3 from the thread list. If thread 2 was re-resumed, we
4739 ignore this event. If we find no thread resumed, then we cancel
4740 the synchronous command show "no unwaited-for " to the user. */
4741 update_thread_list ();
4743 ALL_NON_EXITED_THREADS (thread)
4745 if (thread->executing
4746 || thread->suspend.waitstatus_pending_p)
4748 /* There were no unwaited-for children left in the target at
4749 some point, but there are now. Just ignore. */
4751 fprintf_unfiltered (gdb_stdlog,
4752 "infrun: TARGET_WAITKIND_NO_RESUMED "
4753 "(ignoring: found resumed)\n");
4754 prepare_to_wait (ecs);
4759 /* Note however that we may find no resumed thread because the whole
4760 process exited meanwhile (thus updating the thread list results
4761 in an empty thread list). In this case we know we'll be getting
4762 a process exit event shortly. */
4768 thread = any_live_thread_of_process (inf->pid);
4772 fprintf_unfiltered (gdb_stdlog,
4773 "infrun: TARGET_WAITKIND_NO_RESUMED "
4774 "(expect process exit)\n");
4775 prepare_to_wait (ecs);
4780 /* Go ahead and report the event. */
4784 /* Given an execution control state that has been freshly filled in by
4785 an event from the inferior, figure out what it means and take
4788 The alternatives are:
4790 1) stop_waiting and return; to really stop and return to the
4793 2) keep_going and return; to wait for the next event (set
4794 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4798 handle_inferior_event_1 (struct execution_control_state *ecs)
4800 enum stop_kind stop_soon;
4802 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4804 /* We had an event in the inferior, but we are not interested in
4805 handling it at this level. The lower layers have already
4806 done what needs to be done, if anything.
4808 One of the possible circumstances for this is when the
4809 inferior produces output for the console. The inferior has
4810 not stopped, and we are ignoring the event. Another possible
4811 circumstance is any event which the lower level knows will be
4812 reported multiple times without an intervening resume. */
4814 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4815 prepare_to_wait (ecs);
4819 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4822 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4823 prepare_to_wait (ecs);
4827 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4828 && handle_no_resumed (ecs))
4831 /* Cache the last pid/waitstatus. */
4832 set_last_target_status (ecs->ptid, ecs->ws);
4834 /* Always clear state belonging to the previous time we stopped. */
4835 stop_stack_dummy = STOP_NONE;
4837 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4839 /* No unwaited-for children left. IOW, all resumed children
4842 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4844 stop_print_frame = 0;
4849 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4850 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4852 ecs->event_thread = find_thread_ptid (ecs->ptid);
4853 /* If it's a new thread, add it to the thread database. */
4854 if (ecs->event_thread == NULL)
4855 ecs->event_thread = add_thread (ecs->ptid);
4857 /* Disable range stepping. If the next step request could use a
4858 range, this will be end up re-enabled then. */
4859 ecs->event_thread->control.may_range_step = 0;
4862 /* Dependent on valid ECS->EVENT_THREAD. */
4863 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4865 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4866 reinit_frame_cache ();
4868 breakpoint_retire_moribund ();
4870 /* First, distinguish signals caused by the debugger from signals
4871 that have to do with the program's own actions. Note that
4872 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4873 on the operating system version. Here we detect when a SIGILL or
4874 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4875 something similar for SIGSEGV, since a SIGSEGV will be generated
4876 when we're trying to execute a breakpoint instruction on a
4877 non-executable stack. This happens for call dummy breakpoints
4878 for architectures like SPARC that place call dummies on the
4880 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4881 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4882 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4883 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4885 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4887 if (breakpoint_inserted_here_p (regcache->aspace (),
4888 regcache_read_pc (regcache)))
4891 fprintf_unfiltered (gdb_stdlog,
4892 "infrun: Treating signal as SIGTRAP\n");
4893 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4897 /* Mark the non-executing threads accordingly. In all-stop, all
4898 threads of all processes are stopped when we get any event
4899 reported. In non-stop mode, only the event thread stops. */
4903 if (!target_is_non_stop_p ())
4904 mark_ptid = minus_one_ptid;
4905 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4906 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4908 /* If we're handling a process exit in non-stop mode, even
4909 though threads haven't been deleted yet, one would think
4910 that there is nothing to do, as threads of the dead process
4911 will be soon deleted, and threads of any other process were
4912 left running. However, on some targets, threads survive a
4913 process exit event. E.g., for the "checkpoint" command,
4914 when the current checkpoint/fork exits, linux-fork.c
4915 automatically switches to another fork from within
4916 target_mourn_inferior, by associating the same
4917 inferior/thread to another fork. We haven't mourned yet at
4918 this point, but we must mark any threads left in the
4919 process as not-executing so that finish_thread_state marks
4920 them stopped (in the user's perspective) if/when we present
4921 the stop to the user. */
4922 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4925 mark_ptid = ecs->ptid;
4927 set_executing (mark_ptid, 0);
4929 /* Likewise the resumed flag. */
4930 set_resumed (mark_ptid, 0);
4933 switch (ecs->ws.kind)
4935 case TARGET_WAITKIND_LOADED:
4937 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4938 if (!ptid_equal (ecs->ptid, inferior_ptid))
4939 context_switch (ecs->ptid);
4940 /* Ignore gracefully during startup of the inferior, as it might
4941 be the shell which has just loaded some objects, otherwise
4942 add the symbols for the newly loaded objects. Also ignore at
4943 the beginning of an attach or remote session; we will query
4944 the full list of libraries once the connection is
4947 stop_soon = get_inferior_stop_soon (ecs->ptid);
4948 if (stop_soon == NO_STOP_QUIETLY)
4950 struct regcache *regcache;
4952 regcache = get_thread_regcache (ecs->ptid);
4954 handle_solib_event ();
4956 ecs->event_thread->control.stop_bpstat
4957 = bpstat_stop_status (regcache->aspace (),
4958 stop_pc, ecs->ptid, &ecs->ws);
4960 if (handle_stop_requested (ecs))
4963 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4965 /* A catchpoint triggered. */
4966 process_event_stop_test (ecs);
4970 /* If requested, stop when the dynamic linker notifies
4971 gdb of events. This allows the user to get control
4972 and place breakpoints in initializer routines for
4973 dynamically loaded objects (among other things). */
4974 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4975 if (stop_on_solib_events)
4977 /* Make sure we print "Stopped due to solib-event" in
4979 stop_print_frame = 1;
4986 /* If we are skipping through a shell, or through shared library
4987 loading that we aren't interested in, resume the program. If
4988 we're running the program normally, also resume. */
4989 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4991 /* Loading of shared libraries might have changed breakpoint
4992 addresses. Make sure new breakpoints are inserted. */
4993 if (stop_soon == NO_STOP_QUIETLY)
4994 insert_breakpoints ();
4995 resume (GDB_SIGNAL_0);
4996 prepare_to_wait (ecs);
5000 /* But stop if we're attaching or setting up a remote
5002 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5003 || stop_soon == STOP_QUIETLY_REMOTE)
5006 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5011 internal_error (__FILE__, __LINE__,
5012 _("unhandled stop_soon: %d"), (int) stop_soon);
5014 case TARGET_WAITKIND_SPURIOUS:
5016 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5017 if (handle_stop_requested (ecs))
5019 if (!ptid_equal (ecs->ptid, inferior_ptid))
5020 context_switch (ecs->ptid);
5021 resume (GDB_SIGNAL_0);
5022 prepare_to_wait (ecs);
5025 case TARGET_WAITKIND_THREAD_CREATED:
5027 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5028 if (handle_stop_requested (ecs))
5030 if (!ptid_equal (ecs->ptid, inferior_ptid))
5031 context_switch (ecs->ptid);
5032 if (!switch_back_to_stepped_thread (ecs))
5036 case TARGET_WAITKIND_EXITED:
5037 case TARGET_WAITKIND_SIGNALLED:
5040 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5041 fprintf_unfiltered (gdb_stdlog,
5042 "infrun: TARGET_WAITKIND_EXITED\n");
5044 fprintf_unfiltered (gdb_stdlog,
5045 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5048 inferior_ptid = ecs->ptid;
5049 set_current_inferior (find_inferior_ptid (ecs->ptid));
5050 set_current_program_space (current_inferior ()->pspace);
5051 handle_vfork_child_exec_or_exit (0);
5052 target_terminal::ours (); /* Must do this before mourn anyway. */
5054 /* Clearing any previous state of convenience variables. */
5055 clear_exit_convenience_vars ();
5057 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5059 /* Record the exit code in the convenience variable $_exitcode, so
5060 that the user can inspect this again later. */
5061 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5062 (LONGEST) ecs->ws.value.integer);
5064 /* Also record this in the inferior itself. */
5065 current_inferior ()->has_exit_code = 1;
5066 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5068 /* Support the --return-child-result option. */
5069 return_child_result_value = ecs->ws.value.integer;
5071 observer_notify_exited (ecs->ws.value.integer);
5075 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5076 struct gdbarch *gdbarch = regcache->arch ();
5078 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5080 /* Set the value of the internal variable $_exitsignal,
5081 which holds the signal uncaught by the inferior. */
5082 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5083 gdbarch_gdb_signal_to_target (gdbarch,
5084 ecs->ws.value.sig));
5088 /* We don't have access to the target's method used for
5089 converting between signal numbers (GDB's internal
5090 representation <-> target's representation).
5091 Therefore, we cannot do a good job at displaying this
5092 information to the user. It's better to just warn
5093 her about it (if infrun debugging is enabled), and
5096 fprintf_filtered (gdb_stdlog, _("\
5097 Cannot fill $_exitsignal with the correct signal number.\n"));
5100 observer_notify_signal_exited (ecs->ws.value.sig);
5103 gdb_flush (gdb_stdout);
5104 target_mourn_inferior (inferior_ptid);
5105 stop_print_frame = 0;
5109 /* The following are the only cases in which we keep going;
5110 the above cases end in a continue or goto. */
5111 case TARGET_WAITKIND_FORKED:
5112 case TARGET_WAITKIND_VFORKED:
5115 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5116 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5118 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5121 /* Check whether the inferior is displaced stepping. */
5123 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5124 struct gdbarch *gdbarch = regcache->arch ();
5126 /* If checking displaced stepping is supported, and thread
5127 ecs->ptid is displaced stepping. */
5128 if (displaced_step_in_progress_thread (ecs->ptid))
5130 struct inferior *parent_inf
5131 = find_inferior_ptid (ecs->ptid);
5132 struct regcache *child_regcache;
5133 CORE_ADDR parent_pc;
5135 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5136 indicating that the displaced stepping of syscall instruction
5137 has been done. Perform cleanup for parent process here. Note
5138 that this operation also cleans up the child process for vfork,
5139 because their pages are shared. */
5140 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
5141 /* Start a new step-over in another thread if there's one
5145 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5147 struct displaced_step_inferior_state *displaced
5148 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
5150 /* Restore scratch pad for child process. */
5151 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5154 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5155 the child's PC is also within the scratchpad. Set the child's PC
5156 to the parent's PC value, which has already been fixed up.
5157 FIXME: we use the parent's aspace here, although we're touching
5158 the child, because the child hasn't been added to the inferior
5159 list yet at this point. */
5162 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5164 parent_inf->aspace);
5165 /* Read PC value of parent process. */
5166 parent_pc = regcache_read_pc (regcache);
5168 if (debug_displaced)
5169 fprintf_unfiltered (gdb_stdlog,
5170 "displaced: write child pc from %s to %s\n",
5172 regcache_read_pc (child_regcache)),
5173 paddress (gdbarch, parent_pc));
5175 regcache_write_pc (child_regcache, parent_pc);
5179 if (!ptid_equal (ecs->ptid, inferior_ptid))
5180 context_switch (ecs->ptid);
5182 /* Immediately detach breakpoints from the child before there's
5183 any chance of letting the user delete breakpoints from the
5184 breakpoint lists. If we don't do this early, it's easy to
5185 leave left over traps in the child, vis: "break foo; catch
5186 fork; c; <fork>; del; c; <child calls foo>". We only follow
5187 the fork on the last `continue', and by that time the
5188 breakpoint at "foo" is long gone from the breakpoint table.
5189 If we vforked, then we don't need to unpatch here, since both
5190 parent and child are sharing the same memory pages; we'll
5191 need to unpatch at follow/detach time instead to be certain
5192 that new breakpoints added between catchpoint hit time and
5193 vfork follow are detached. */
5194 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5196 /* This won't actually modify the breakpoint list, but will
5197 physically remove the breakpoints from the child. */
5198 detach_breakpoints (ecs->ws.value.related_pid);
5201 delete_just_stopped_threads_single_step_breakpoints ();
5203 /* In case the event is caught by a catchpoint, remember that
5204 the event is to be followed at the next resume of the thread,
5205 and not immediately. */
5206 ecs->event_thread->pending_follow = ecs->ws;
5208 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5210 ecs->event_thread->control.stop_bpstat
5211 = bpstat_stop_status (get_current_regcache ()->aspace (),
5212 stop_pc, ecs->ptid, &ecs->ws);
5214 if (handle_stop_requested (ecs))
5217 /* If no catchpoint triggered for this, then keep going. Note
5218 that we're interested in knowing the bpstat actually causes a
5219 stop, not just if it may explain the signal. Software
5220 watchpoints, for example, always appear in the bpstat. */
5221 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5227 = (follow_fork_mode_string == follow_fork_mode_child);
5229 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5231 should_resume = follow_fork ();
5234 child = ecs->ws.value.related_pid;
5236 /* At this point, the parent is marked running, and the
5237 child is marked stopped. */
5239 /* If not resuming the parent, mark it stopped. */
5240 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5241 set_running (parent, 0);
5243 /* If resuming the child, mark it running. */
5244 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5245 set_running (child, 1);
5247 /* In non-stop mode, also resume the other branch. */
5248 if (!detach_fork && (non_stop
5249 || (sched_multi && target_is_non_stop_p ())))
5252 switch_to_thread (parent);
5254 switch_to_thread (child);
5256 ecs->event_thread = inferior_thread ();
5257 ecs->ptid = inferior_ptid;
5262 switch_to_thread (child);
5264 switch_to_thread (parent);
5266 ecs->event_thread = inferior_thread ();
5267 ecs->ptid = inferior_ptid;
5275 process_event_stop_test (ecs);
5278 case TARGET_WAITKIND_VFORK_DONE:
5279 /* Done with the shared memory region. Re-insert breakpoints in
5280 the parent, and keep going. */
5283 fprintf_unfiltered (gdb_stdlog,
5284 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5286 if (!ptid_equal (ecs->ptid, inferior_ptid))
5287 context_switch (ecs->ptid);
5289 current_inferior ()->waiting_for_vfork_done = 0;
5290 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5292 if (handle_stop_requested (ecs))
5295 /* This also takes care of reinserting breakpoints in the
5296 previously locked inferior. */
5300 case TARGET_WAITKIND_EXECD:
5302 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5304 /* Note we can't read registers yet (the stop_pc), because we
5305 don't yet know the inferior's post-exec architecture.
5306 'stop_pc' is explicitly read below instead. */
5307 if (!ptid_equal (ecs->ptid, inferior_ptid))
5308 switch_to_thread_no_regs (ecs->event_thread);
5310 /* Do whatever is necessary to the parent branch of the vfork. */
5311 handle_vfork_child_exec_or_exit (1);
5313 /* This causes the eventpoints and symbol table to be reset.
5314 Must do this now, before trying to determine whether to
5316 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5318 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5320 /* In follow_exec we may have deleted the original thread and
5321 created a new one. Make sure that the event thread is the
5322 execd thread for that case (this is a nop otherwise). */
5323 ecs->event_thread = inferior_thread ();
5325 ecs->event_thread->control.stop_bpstat
5326 = bpstat_stop_status (get_current_regcache ()->aspace (),
5327 stop_pc, ecs->ptid, &ecs->ws);
5329 /* Note that this may be referenced from inside
5330 bpstat_stop_status above, through inferior_has_execd. */
5331 xfree (ecs->ws.value.execd_pathname);
5332 ecs->ws.value.execd_pathname = NULL;
5334 if (handle_stop_requested (ecs))
5337 /* If no catchpoint triggered for this, then keep going. */
5338 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5340 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5344 process_event_stop_test (ecs);
5347 /* Be careful not to try to gather much state about a thread
5348 that's in a syscall. It's frequently a losing proposition. */
5349 case TARGET_WAITKIND_SYSCALL_ENTRY:
5351 fprintf_unfiltered (gdb_stdlog,
5352 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5353 /* Getting the current syscall number. */
5354 if (handle_syscall_event (ecs) == 0)
5355 process_event_stop_test (ecs);
5358 /* Before examining the threads further, step this thread to
5359 get it entirely out of the syscall. (We get notice of the
5360 event when the thread is just on the verge of exiting a
5361 syscall. Stepping one instruction seems to get it back
5363 case TARGET_WAITKIND_SYSCALL_RETURN:
5365 fprintf_unfiltered (gdb_stdlog,
5366 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5367 if (handle_syscall_event (ecs) == 0)
5368 process_event_stop_test (ecs);
5371 case TARGET_WAITKIND_STOPPED:
5373 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5374 handle_signal_stop (ecs);
5377 case TARGET_WAITKIND_NO_HISTORY:
5379 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5380 /* Reverse execution: target ran out of history info. */
5382 /* Switch to the stopped thread. */
5383 if (!ptid_equal (ecs->ptid, inferior_ptid))
5384 context_switch (ecs->ptid);
5386 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5388 delete_just_stopped_threads_single_step_breakpoints ();
5389 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5391 if (handle_stop_requested (ecs))
5394 observer_notify_no_history ();
5400 /* A wrapper around handle_inferior_event_1, which also makes sure
5401 that all temporary struct value objects that were created during
5402 the handling of the event get deleted at the end. */
5405 handle_inferior_event (struct execution_control_state *ecs)
5407 struct value *mark = value_mark ();
5409 handle_inferior_event_1 (ecs);
5410 /* Purge all temporary values created during the event handling,
5411 as it could be a long time before we return to the command level
5412 where such values would otherwise be purged. */
5413 value_free_to_mark (mark);
5416 /* Restart threads back to what they were trying to do back when we
5417 paused them for an in-line step-over. The EVENT_THREAD thread is
5421 restart_threads (struct thread_info *event_thread)
5423 struct thread_info *tp;
5425 /* In case the instruction just stepped spawned a new thread. */
5426 update_thread_list ();
5428 ALL_NON_EXITED_THREADS (tp)
5430 if (tp == event_thread)
5433 fprintf_unfiltered (gdb_stdlog,
5434 "infrun: restart threads: "
5435 "[%s] is event thread\n",
5436 target_pid_to_str (tp->ptid));
5440 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5443 fprintf_unfiltered (gdb_stdlog,
5444 "infrun: restart threads: "
5445 "[%s] not meant to be running\n",
5446 target_pid_to_str (tp->ptid));
5453 fprintf_unfiltered (gdb_stdlog,
5454 "infrun: restart threads: [%s] resumed\n",
5455 target_pid_to_str (tp->ptid));
5456 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5460 if (thread_is_in_step_over_chain (tp))
5463 fprintf_unfiltered (gdb_stdlog,
5464 "infrun: restart threads: "
5465 "[%s] needs step-over\n",
5466 target_pid_to_str (tp->ptid));
5467 gdb_assert (!tp->resumed);
5472 if (tp->suspend.waitstatus_pending_p)
5475 fprintf_unfiltered (gdb_stdlog,
5476 "infrun: restart threads: "
5477 "[%s] has pending status\n",
5478 target_pid_to_str (tp->ptid));
5483 gdb_assert (!tp->stop_requested);
5485 /* If some thread needs to start a step-over at this point, it
5486 should still be in the step-over queue, and thus skipped
5488 if (thread_still_needs_step_over (tp))
5490 internal_error (__FILE__, __LINE__,
5491 "thread [%s] needs a step-over, but not in "
5492 "step-over queue\n",
5493 target_pid_to_str (tp->ptid));
5496 if (currently_stepping (tp))
5499 fprintf_unfiltered (gdb_stdlog,
5500 "infrun: restart threads: [%s] was stepping\n",
5501 target_pid_to_str (tp->ptid));
5502 keep_going_stepped_thread (tp);
5506 struct execution_control_state ecss;
5507 struct execution_control_state *ecs = &ecss;
5510 fprintf_unfiltered (gdb_stdlog,
5511 "infrun: restart threads: [%s] continuing\n",
5512 target_pid_to_str (tp->ptid));
5513 reset_ecs (ecs, tp);
5514 switch_to_thread (tp->ptid);
5515 keep_going_pass_signal (ecs);
5520 /* Callback for iterate_over_threads. Find a resumed thread that has
5521 a pending waitstatus. */
5524 resumed_thread_with_pending_status (struct thread_info *tp,
5528 && tp->suspend.waitstatus_pending_p);
5531 /* Called when we get an event that may finish an in-line or
5532 out-of-line (displaced stepping) step-over started previously.
5533 Return true if the event is processed and we should go back to the
5534 event loop; false if the caller should continue processing the
5538 finish_step_over (struct execution_control_state *ecs)
5540 int had_step_over_info;
5542 displaced_step_fixup (ecs->ptid,
5543 ecs->event_thread->suspend.stop_signal);
5545 had_step_over_info = step_over_info_valid_p ();
5547 if (had_step_over_info)
5549 /* If we're stepping over a breakpoint with all threads locked,
5550 then only the thread that was stepped should be reporting
5552 gdb_assert (ecs->event_thread->control.trap_expected);
5554 clear_step_over_info ();
5557 if (!target_is_non_stop_p ())
5560 /* Start a new step-over in another thread if there's one that
5564 /* If we were stepping over a breakpoint before, and haven't started
5565 a new in-line step-over sequence, then restart all other threads
5566 (except the event thread). We can't do this in all-stop, as then
5567 e.g., we wouldn't be able to issue any other remote packet until
5568 these other threads stop. */
5569 if (had_step_over_info && !step_over_info_valid_p ())
5571 struct thread_info *pending;
5573 /* If we only have threads with pending statuses, the restart
5574 below won't restart any thread and so nothing re-inserts the
5575 breakpoint we just stepped over. But we need it inserted
5576 when we later process the pending events, otherwise if
5577 another thread has a pending event for this breakpoint too,
5578 we'd discard its event (because the breakpoint that
5579 originally caused the event was no longer inserted). */
5580 context_switch (ecs->ptid);
5581 insert_breakpoints ();
5583 restart_threads (ecs->event_thread);
5585 /* If we have events pending, go through handle_inferior_event
5586 again, picking up a pending event at random. This avoids
5587 thread starvation. */
5589 /* But not if we just stepped over a watchpoint in order to let
5590 the instruction execute so we can evaluate its expression.
5591 The set of watchpoints that triggered is recorded in the
5592 breakpoint objects themselves (see bp->watchpoint_triggered).
5593 If we processed another event first, that other event could
5594 clobber this info. */
5595 if (ecs->event_thread->stepping_over_watchpoint)
5598 pending = iterate_over_threads (resumed_thread_with_pending_status,
5600 if (pending != NULL)
5602 struct thread_info *tp = ecs->event_thread;
5603 struct regcache *regcache;
5607 fprintf_unfiltered (gdb_stdlog,
5608 "infrun: found resumed threads with "
5609 "pending events, saving status\n");
5612 gdb_assert (pending != tp);
5614 /* Record the event thread's event for later. */
5615 save_waitstatus (tp, &ecs->ws);
5616 /* This was cleared early, by handle_inferior_event. Set it
5617 so this pending event is considered by
5621 gdb_assert (!tp->executing);
5623 regcache = get_thread_regcache (tp->ptid);
5624 tp->suspend.stop_pc = regcache_read_pc (regcache);
5628 fprintf_unfiltered (gdb_stdlog,
5629 "infrun: saved stop_pc=%s for %s "
5630 "(currently_stepping=%d)\n",
5631 paddress (target_gdbarch (),
5632 tp->suspend.stop_pc),
5633 target_pid_to_str (tp->ptid),
5634 currently_stepping (tp));
5637 /* This in-line step-over finished; clear this so we won't
5638 start a new one. This is what handle_signal_stop would
5639 do, if we returned false. */
5640 tp->stepping_over_breakpoint = 0;
5642 /* Wake up the event loop again. */
5643 mark_async_event_handler (infrun_async_inferior_event_token);
5645 prepare_to_wait (ecs);
5653 /* Come here when the program has stopped with a signal. */
5656 handle_signal_stop (struct execution_control_state *ecs)
5658 struct frame_info *frame;
5659 struct gdbarch *gdbarch;
5660 int stopped_by_watchpoint;
5661 enum stop_kind stop_soon;
5664 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5666 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5668 /* Do we need to clean up the state of a thread that has
5669 completed a displaced single-step? (Doing so usually affects
5670 the PC, so do it here, before we set stop_pc.) */
5671 if (finish_step_over (ecs))
5674 /* If we either finished a single-step or hit a breakpoint, but
5675 the user wanted this thread to be stopped, pretend we got a
5676 SIG0 (generic unsignaled stop). */
5677 if (ecs->event_thread->stop_requested
5678 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5679 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5681 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5685 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5686 struct gdbarch *gdbarch = regcache->arch ();
5687 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5689 inferior_ptid = ecs->ptid;
5691 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5692 paddress (gdbarch, stop_pc));
5693 if (target_stopped_by_watchpoint ())
5697 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5699 if (target_stopped_data_address (¤t_target, &addr))
5700 fprintf_unfiltered (gdb_stdlog,
5701 "infrun: stopped data address = %s\n",
5702 paddress (gdbarch, addr));
5704 fprintf_unfiltered (gdb_stdlog,
5705 "infrun: (no data address available)\n");
5709 /* This is originated from start_remote(), start_inferior() and
5710 shared libraries hook functions. */
5711 stop_soon = get_inferior_stop_soon (ecs->ptid);
5712 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5714 if (!ptid_equal (ecs->ptid, inferior_ptid))
5715 context_switch (ecs->ptid);
5717 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5718 stop_print_frame = 1;
5723 /* This originates from attach_command(). We need to overwrite
5724 the stop_signal here, because some kernels don't ignore a
5725 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5726 See more comments in inferior.h. On the other hand, if we
5727 get a non-SIGSTOP, report it to the user - assume the backend
5728 will handle the SIGSTOP if it should show up later.
5730 Also consider that the attach is complete when we see a
5731 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5732 target extended-remote report it instead of a SIGSTOP
5733 (e.g. gdbserver). We already rely on SIGTRAP being our
5734 signal, so this is no exception.
5736 Also consider that the attach is complete when we see a
5737 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5738 the target to stop all threads of the inferior, in case the
5739 low level attach operation doesn't stop them implicitly. If
5740 they weren't stopped implicitly, then the stub will report a
5741 GDB_SIGNAL_0, meaning: stopped for no particular reason
5742 other than GDB's request. */
5743 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5744 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5745 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5746 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5748 stop_print_frame = 1;
5750 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5754 /* See if something interesting happened to the non-current thread. If
5755 so, then switch to that thread. */
5756 if (!ptid_equal (ecs->ptid, inferior_ptid))
5759 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5761 context_switch (ecs->ptid);
5763 if (deprecated_context_hook)
5764 deprecated_context_hook (ptid_to_global_thread_id (ecs->ptid));
5767 /* At this point, get hold of the now-current thread's frame. */
5768 frame = get_current_frame ();
5769 gdbarch = get_frame_arch (frame);
5771 /* Pull the single step breakpoints out of the target. */
5772 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5774 struct regcache *regcache;
5777 regcache = get_thread_regcache (ecs->ptid);
5778 const address_space *aspace = regcache->aspace ();
5780 pc = regcache_read_pc (regcache);
5782 /* However, before doing so, if this single-step breakpoint was
5783 actually for another thread, set this thread up for moving
5785 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5788 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5792 fprintf_unfiltered (gdb_stdlog,
5793 "infrun: [%s] hit another thread's "
5794 "single-step breakpoint\n",
5795 target_pid_to_str (ecs->ptid));
5797 ecs->hit_singlestep_breakpoint = 1;
5804 fprintf_unfiltered (gdb_stdlog,
5805 "infrun: [%s] hit its "
5806 "single-step breakpoint\n",
5807 target_pid_to_str (ecs->ptid));
5811 delete_just_stopped_threads_single_step_breakpoints ();
5813 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5814 && ecs->event_thread->control.trap_expected
5815 && ecs->event_thread->stepping_over_watchpoint)
5816 stopped_by_watchpoint = 0;
5818 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5820 /* If necessary, step over this watchpoint. We'll be back to display
5822 if (stopped_by_watchpoint
5823 && (target_have_steppable_watchpoint
5824 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5826 /* At this point, we are stopped at an instruction which has
5827 attempted to write to a piece of memory under control of
5828 a watchpoint. The instruction hasn't actually executed
5829 yet. If we were to evaluate the watchpoint expression
5830 now, we would get the old value, and therefore no change
5831 would seem to have occurred.
5833 In order to make watchpoints work `right', we really need
5834 to complete the memory write, and then evaluate the
5835 watchpoint expression. We do this by single-stepping the
5838 It may not be necessary to disable the watchpoint to step over
5839 it. For example, the PA can (with some kernel cooperation)
5840 single step over a watchpoint without disabling the watchpoint.
5842 It is far more common to need to disable a watchpoint to step
5843 the inferior over it. If we have non-steppable watchpoints,
5844 we must disable the current watchpoint; it's simplest to
5845 disable all watchpoints.
5847 Any breakpoint at PC must also be stepped over -- if there's
5848 one, it will have already triggered before the watchpoint
5849 triggered, and we either already reported it to the user, or
5850 it didn't cause a stop and we called keep_going. In either
5851 case, if there was a breakpoint at PC, we must be trying to
5853 ecs->event_thread->stepping_over_watchpoint = 1;
5858 ecs->event_thread->stepping_over_breakpoint = 0;
5859 ecs->event_thread->stepping_over_watchpoint = 0;
5860 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5861 ecs->event_thread->control.stop_step = 0;
5862 stop_print_frame = 1;
5863 stopped_by_random_signal = 0;
5865 /* Hide inlined functions starting here, unless we just performed stepi or
5866 nexti. After stepi and nexti, always show the innermost frame (not any
5867 inline function call sites). */
5868 if (ecs->event_thread->control.step_range_end != 1)
5870 const address_space *aspace =
5871 get_thread_regcache (ecs->ptid)->aspace ();
5873 /* skip_inline_frames is expensive, so we avoid it if we can
5874 determine that the address is one where functions cannot have
5875 been inlined. This improves performance with inferiors that
5876 load a lot of shared libraries, because the solib event
5877 breakpoint is defined as the address of a function (i.e. not
5878 inline). Note that we have to check the previous PC as well
5879 as the current one to catch cases when we have just
5880 single-stepped off a breakpoint prior to reinstating it.
5881 Note that we're assuming that the code we single-step to is
5882 not inline, but that's not definitive: there's nothing
5883 preventing the event breakpoint function from containing
5884 inlined code, and the single-step ending up there. If the
5885 user had set a breakpoint on that inlined code, the missing
5886 skip_inline_frames call would break things. Fortunately
5887 that's an extremely unlikely scenario. */
5888 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5889 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5890 && ecs->event_thread->control.trap_expected
5891 && pc_at_non_inline_function (aspace,
5892 ecs->event_thread->prev_pc,
5895 skip_inline_frames (ecs->ptid);
5897 /* Re-fetch current thread's frame in case that invalidated
5899 frame = get_current_frame ();
5900 gdbarch = get_frame_arch (frame);
5904 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5905 && ecs->event_thread->control.trap_expected
5906 && gdbarch_single_step_through_delay_p (gdbarch)
5907 && currently_stepping (ecs->event_thread))
5909 /* We're trying to step off a breakpoint. Turns out that we're
5910 also on an instruction that needs to be stepped multiple
5911 times before it's been fully executing. E.g., architectures
5912 with a delay slot. It needs to be stepped twice, once for
5913 the instruction and once for the delay slot. */
5914 int step_through_delay
5915 = gdbarch_single_step_through_delay (gdbarch, frame);
5917 if (debug_infrun && step_through_delay)
5918 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5919 if (ecs->event_thread->control.step_range_end == 0
5920 && step_through_delay)
5922 /* The user issued a continue when stopped at a breakpoint.
5923 Set up for another trap and get out of here. */
5924 ecs->event_thread->stepping_over_breakpoint = 1;
5928 else if (step_through_delay)
5930 /* The user issued a step when stopped at a breakpoint.
5931 Maybe we should stop, maybe we should not - the delay
5932 slot *might* correspond to a line of source. In any
5933 case, don't decide that here, just set
5934 ecs->stepping_over_breakpoint, making sure we
5935 single-step again before breakpoints are re-inserted. */
5936 ecs->event_thread->stepping_over_breakpoint = 1;
5940 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5941 handles this event. */
5942 ecs->event_thread->control.stop_bpstat
5943 = bpstat_stop_status (get_current_regcache ()->aspace (),
5944 stop_pc, ecs->ptid, &ecs->ws);
5946 /* Following in case break condition called a
5948 stop_print_frame = 1;
5950 /* This is where we handle "moribund" watchpoints. Unlike
5951 software breakpoints traps, hardware watchpoint traps are
5952 always distinguishable from random traps. If no high-level
5953 watchpoint is associated with the reported stop data address
5954 anymore, then the bpstat does not explain the signal ---
5955 simply make sure to ignore it if `stopped_by_watchpoint' is
5959 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5960 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5962 && stopped_by_watchpoint)
5963 fprintf_unfiltered (gdb_stdlog,
5964 "infrun: no user watchpoint explains "
5965 "watchpoint SIGTRAP, ignoring\n");
5967 /* NOTE: cagney/2003-03-29: These checks for a random signal
5968 at one stage in the past included checks for an inferior
5969 function call's call dummy's return breakpoint. The original
5970 comment, that went with the test, read:
5972 ``End of a stack dummy. Some systems (e.g. Sony news) give
5973 another signal besides SIGTRAP, so check here as well as
5976 If someone ever tries to get call dummys on a
5977 non-executable stack to work (where the target would stop
5978 with something like a SIGSEGV), then those tests might need
5979 to be re-instated. Given, however, that the tests were only
5980 enabled when momentary breakpoints were not being used, I
5981 suspect that it won't be the case.
5983 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5984 be necessary for call dummies on a non-executable stack on
5987 /* See if the breakpoints module can explain the signal. */
5989 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5990 ecs->event_thread->suspend.stop_signal);
5992 /* Maybe this was a trap for a software breakpoint that has since
5994 if (random_signal && target_stopped_by_sw_breakpoint ())
5996 if (program_breakpoint_here_p (gdbarch, stop_pc))
5998 struct regcache *regcache;
6001 /* Re-adjust PC to what the program would see if GDB was not
6003 regcache = get_thread_regcache (ecs->event_thread->ptid);
6004 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
6007 gdb::optional<scoped_restore_tmpl<int>>
6008 restore_operation_disable;
6010 if (record_full_is_used ())
6011 restore_operation_disable.emplace
6012 (record_full_gdb_operation_disable_set ());
6014 regcache_write_pc (regcache, stop_pc + decr_pc);
6019 /* A delayed software breakpoint event. Ignore the trap. */
6021 fprintf_unfiltered (gdb_stdlog,
6022 "infrun: delayed software breakpoint "
6023 "trap, ignoring\n");
6028 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6029 has since been removed. */
6030 if (random_signal && target_stopped_by_hw_breakpoint ())
6032 /* A delayed hardware breakpoint event. Ignore the trap. */
6034 fprintf_unfiltered (gdb_stdlog,
6035 "infrun: delayed hardware breakpoint/watchpoint "
6036 "trap, ignoring\n");
6040 /* If not, perhaps stepping/nexting can. */
6042 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6043 && currently_stepping (ecs->event_thread));
6045 /* Perhaps the thread hit a single-step breakpoint of _another_
6046 thread. Single-step breakpoints are transparent to the
6047 breakpoints module. */
6049 random_signal = !ecs->hit_singlestep_breakpoint;
6051 /* No? Perhaps we got a moribund watchpoint. */
6053 random_signal = !stopped_by_watchpoint;
6055 /* Always stop if the user explicitly requested this thread to
6057 if (ecs->event_thread->stop_requested)
6061 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6064 /* For the program's own signals, act according to
6065 the signal handling tables. */
6069 /* Signal not for debugging purposes. */
6070 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6071 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6074 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6075 gdb_signal_to_symbol_string (stop_signal));
6077 stopped_by_random_signal = 1;
6079 /* Always stop on signals if we're either just gaining control
6080 of the program, or the user explicitly requested this thread
6081 to remain stopped. */
6082 if (stop_soon != NO_STOP_QUIETLY
6083 || ecs->event_thread->stop_requested
6085 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6091 /* Notify observers the signal has "handle print" set. Note we
6092 returned early above if stopping; normal_stop handles the
6093 printing in that case. */
6094 if (signal_print[ecs->event_thread->suspend.stop_signal])
6096 /* The signal table tells us to print about this signal. */
6097 target_terminal::ours_for_output ();
6098 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
6099 target_terminal::inferior ();
6102 /* Clear the signal if it should not be passed. */
6103 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6104 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6106 if (ecs->event_thread->prev_pc == stop_pc
6107 && ecs->event_thread->control.trap_expected
6108 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6110 /* We were just starting a new sequence, attempting to
6111 single-step off of a breakpoint and expecting a SIGTRAP.
6112 Instead this signal arrives. This signal will take us out
6113 of the stepping range so GDB needs to remember to, when
6114 the signal handler returns, resume stepping off that
6116 /* To simplify things, "continue" is forced to use the same
6117 code paths as single-step - set a breakpoint at the
6118 signal return address and then, once hit, step off that
6121 fprintf_unfiltered (gdb_stdlog,
6122 "infrun: signal arrived while stepping over "
6125 insert_hp_step_resume_breakpoint_at_frame (frame);
6126 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6127 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6128 ecs->event_thread->control.trap_expected = 0;
6130 /* If we were nexting/stepping some other thread, switch to
6131 it, so that we don't continue it, losing control. */
6132 if (!switch_back_to_stepped_thread (ecs))
6137 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6138 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6139 || ecs->event_thread->control.step_range_end == 1)
6140 && frame_id_eq (get_stack_frame_id (frame),
6141 ecs->event_thread->control.step_stack_frame_id)
6142 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6144 /* The inferior is about to take a signal that will take it
6145 out of the single step range. Set a breakpoint at the
6146 current PC (which is presumably where the signal handler
6147 will eventually return) and then allow the inferior to
6150 Note that this is only needed for a signal delivered
6151 while in the single-step range. Nested signals aren't a
6152 problem as they eventually all return. */
6154 fprintf_unfiltered (gdb_stdlog,
6155 "infrun: signal may take us out of "
6156 "single-step range\n");
6158 clear_step_over_info ();
6159 insert_hp_step_resume_breakpoint_at_frame (frame);
6160 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6161 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6162 ecs->event_thread->control.trap_expected = 0;
6167 /* Note: step_resume_breakpoint may be non-NULL. This occures
6168 when either there's a nested signal, or when there's a
6169 pending signal enabled just as the signal handler returns
6170 (leaving the inferior at the step-resume-breakpoint without
6171 actually executing it). Either way continue until the
6172 breakpoint is really hit. */
6174 if (!switch_back_to_stepped_thread (ecs))
6177 fprintf_unfiltered (gdb_stdlog,
6178 "infrun: random signal, keep going\n");
6185 process_event_stop_test (ecs);
6188 /* Come here when we've got some debug event / signal we can explain
6189 (IOW, not a random signal), and test whether it should cause a
6190 stop, or whether we should resume the inferior (transparently).
6191 E.g., could be a breakpoint whose condition evaluates false; we
6192 could be still stepping within the line; etc. */
6195 process_event_stop_test (struct execution_control_state *ecs)
6197 struct symtab_and_line stop_pc_sal;
6198 struct frame_info *frame;
6199 struct gdbarch *gdbarch;
6200 CORE_ADDR jmp_buf_pc;
6201 struct bpstat_what what;
6203 /* Handle cases caused by hitting a breakpoint. */
6205 frame = get_current_frame ();
6206 gdbarch = get_frame_arch (frame);
6208 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6210 if (what.call_dummy)
6212 stop_stack_dummy = what.call_dummy;
6215 /* A few breakpoint types have callbacks associated (e.g.,
6216 bp_jit_event). Run them now. */
6217 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6219 /* If we hit an internal event that triggers symbol changes, the
6220 current frame will be invalidated within bpstat_what (e.g., if we
6221 hit an internal solib event). Re-fetch it. */
6222 frame = get_current_frame ();
6223 gdbarch = get_frame_arch (frame);
6225 switch (what.main_action)
6227 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6228 /* If we hit the breakpoint at longjmp while stepping, we
6229 install a momentary breakpoint at the target of the
6233 fprintf_unfiltered (gdb_stdlog,
6234 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6236 ecs->event_thread->stepping_over_breakpoint = 1;
6238 if (what.is_longjmp)
6240 struct value *arg_value;
6242 /* If we set the longjmp breakpoint via a SystemTap probe,
6243 then use it to extract the arguments. The destination PC
6244 is the third argument to the probe. */
6245 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6248 jmp_buf_pc = value_as_address (arg_value);
6249 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6251 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6252 || !gdbarch_get_longjmp_target (gdbarch,
6253 frame, &jmp_buf_pc))
6256 fprintf_unfiltered (gdb_stdlog,
6257 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6258 "(!gdbarch_get_longjmp_target)\n");
6263 /* Insert a breakpoint at resume address. */
6264 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6267 check_exception_resume (ecs, frame);
6271 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6273 struct frame_info *init_frame;
6275 /* There are several cases to consider.
6277 1. The initiating frame no longer exists. In this case we
6278 must stop, because the exception or longjmp has gone too
6281 2. The initiating frame exists, and is the same as the
6282 current frame. We stop, because the exception or longjmp
6285 3. The initiating frame exists and is different from the
6286 current frame. This means the exception or longjmp has
6287 been caught beneath the initiating frame, so keep going.
6289 4. longjmp breakpoint has been placed just to protect
6290 against stale dummy frames and user is not interested in
6291 stopping around longjmps. */
6294 fprintf_unfiltered (gdb_stdlog,
6295 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6297 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6299 delete_exception_resume_breakpoint (ecs->event_thread);
6301 if (what.is_longjmp)
6303 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6305 if (!frame_id_p (ecs->event_thread->initiating_frame))
6313 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6317 struct frame_id current_id
6318 = get_frame_id (get_current_frame ());
6319 if (frame_id_eq (current_id,
6320 ecs->event_thread->initiating_frame))
6322 /* Case 2. Fall through. */
6332 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6334 delete_step_resume_breakpoint (ecs->event_thread);
6336 end_stepping_range (ecs);
6340 case BPSTAT_WHAT_SINGLE:
6342 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6343 ecs->event_thread->stepping_over_breakpoint = 1;
6344 /* Still need to check other stuff, at least the case where we
6345 are stepping and step out of the right range. */
6348 case BPSTAT_WHAT_STEP_RESUME:
6350 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6352 delete_step_resume_breakpoint (ecs->event_thread);
6353 if (ecs->event_thread->control.proceed_to_finish
6354 && execution_direction == EXEC_REVERSE)
6356 struct thread_info *tp = ecs->event_thread;
6358 /* We are finishing a function in reverse, and just hit the
6359 step-resume breakpoint at the start address of the
6360 function, and we're almost there -- just need to back up
6361 by one more single-step, which should take us back to the
6363 tp->control.step_range_start = tp->control.step_range_end = 1;
6367 fill_in_stop_func (gdbarch, ecs);
6368 if (stop_pc == ecs->stop_func_start
6369 && execution_direction == EXEC_REVERSE)
6371 /* We are stepping over a function call in reverse, and just
6372 hit the step-resume breakpoint at the start address of
6373 the function. Go back to single-stepping, which should
6374 take us back to the function call. */
6375 ecs->event_thread->stepping_over_breakpoint = 1;
6381 case BPSTAT_WHAT_STOP_NOISY:
6383 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6384 stop_print_frame = 1;
6386 /* Assume the thread stopped for a breapoint. We'll still check
6387 whether a/the breakpoint is there when the thread is next
6389 ecs->event_thread->stepping_over_breakpoint = 1;
6394 case BPSTAT_WHAT_STOP_SILENT:
6396 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6397 stop_print_frame = 0;
6399 /* Assume the thread stopped for a breapoint. We'll still check
6400 whether a/the breakpoint is there when the thread is next
6402 ecs->event_thread->stepping_over_breakpoint = 1;
6406 case BPSTAT_WHAT_HP_STEP_RESUME:
6408 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6410 delete_step_resume_breakpoint (ecs->event_thread);
6411 if (ecs->event_thread->step_after_step_resume_breakpoint)
6413 /* Back when the step-resume breakpoint was inserted, we
6414 were trying to single-step off a breakpoint. Go back to
6416 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6417 ecs->event_thread->stepping_over_breakpoint = 1;
6423 case BPSTAT_WHAT_KEEP_CHECKING:
6427 /* If we stepped a permanent breakpoint and we had a high priority
6428 step-resume breakpoint for the address we stepped, but we didn't
6429 hit it, then we must have stepped into the signal handler. The
6430 step-resume was only necessary to catch the case of _not_
6431 stepping into the handler, so delete it, and fall through to
6432 checking whether the step finished. */
6433 if (ecs->event_thread->stepped_breakpoint)
6435 struct breakpoint *sr_bp
6436 = ecs->event_thread->control.step_resume_breakpoint;
6439 && sr_bp->loc->permanent
6440 && sr_bp->type == bp_hp_step_resume
6441 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6444 fprintf_unfiltered (gdb_stdlog,
6445 "infrun: stepped permanent breakpoint, stopped in "
6447 delete_step_resume_breakpoint (ecs->event_thread);
6448 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6452 /* We come here if we hit a breakpoint but should not stop for it.
6453 Possibly we also were stepping and should stop for that. So fall
6454 through and test for stepping. But, if not stepping, do not
6457 /* In all-stop mode, if we're currently stepping but have stopped in
6458 some other thread, we need to switch back to the stepped thread. */
6459 if (switch_back_to_stepped_thread (ecs))
6462 if (ecs->event_thread->control.step_resume_breakpoint)
6465 fprintf_unfiltered (gdb_stdlog,
6466 "infrun: step-resume breakpoint is inserted\n");
6468 /* Having a step-resume breakpoint overrides anything
6469 else having to do with stepping commands until
6470 that breakpoint is reached. */
6475 if (ecs->event_thread->control.step_range_end == 0)
6478 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6479 /* Likewise if we aren't even stepping. */
6484 /* Re-fetch current thread's frame in case the code above caused
6485 the frame cache to be re-initialized, making our FRAME variable
6486 a dangling pointer. */
6487 frame = get_current_frame ();
6488 gdbarch = get_frame_arch (frame);
6489 fill_in_stop_func (gdbarch, ecs);
6491 /* If stepping through a line, keep going if still within it.
6493 Note that step_range_end is the address of the first instruction
6494 beyond the step range, and NOT the address of the last instruction
6497 Note also that during reverse execution, we may be stepping
6498 through a function epilogue and therefore must detect when
6499 the current-frame changes in the middle of a line. */
6501 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6502 && (execution_direction != EXEC_REVERSE
6503 || frame_id_eq (get_frame_id (frame),
6504 ecs->event_thread->control.step_frame_id)))
6508 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6509 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6510 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6512 /* Tentatively re-enable range stepping; `resume' disables it if
6513 necessary (e.g., if we're stepping over a breakpoint or we
6514 have software watchpoints). */
6515 ecs->event_thread->control.may_range_step = 1;
6517 /* When stepping backward, stop at beginning of line range
6518 (unless it's the function entry point, in which case
6519 keep going back to the call point). */
6520 if (stop_pc == ecs->event_thread->control.step_range_start
6521 && stop_pc != ecs->stop_func_start
6522 && execution_direction == EXEC_REVERSE)
6523 end_stepping_range (ecs);
6530 /* We stepped out of the stepping range. */
6532 /* If we are stepping at the source level and entered the runtime
6533 loader dynamic symbol resolution code...
6535 EXEC_FORWARD: we keep on single stepping until we exit the run
6536 time loader code and reach the callee's address.
6538 EXEC_REVERSE: we've already executed the callee (backward), and
6539 the runtime loader code is handled just like any other
6540 undebuggable function call. Now we need only keep stepping
6541 backward through the trampoline code, and that's handled further
6542 down, so there is nothing for us to do here. */
6544 if (execution_direction != EXEC_REVERSE
6545 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6546 && in_solib_dynsym_resolve_code (stop_pc))
6548 CORE_ADDR pc_after_resolver =
6549 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6552 fprintf_unfiltered (gdb_stdlog,
6553 "infrun: stepped into dynsym resolve code\n");
6555 if (pc_after_resolver)
6557 /* Set up a step-resume breakpoint at the address
6558 indicated by SKIP_SOLIB_RESOLVER. */
6559 symtab_and_line sr_sal;
6560 sr_sal.pc = pc_after_resolver;
6561 sr_sal.pspace = get_frame_program_space (frame);
6563 insert_step_resume_breakpoint_at_sal (gdbarch,
6564 sr_sal, null_frame_id);
6571 if (ecs->event_thread->control.step_range_end != 1
6572 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6573 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6574 && get_frame_type (frame) == SIGTRAMP_FRAME)
6577 fprintf_unfiltered (gdb_stdlog,
6578 "infrun: stepped into signal trampoline\n");
6579 /* The inferior, while doing a "step" or "next", has ended up in
6580 a signal trampoline (either by a signal being delivered or by
6581 the signal handler returning). Just single-step until the
6582 inferior leaves the trampoline (either by calling the handler
6588 /* If we're in the return path from a shared library trampoline,
6589 we want to proceed through the trampoline when stepping. */
6590 /* macro/2012-04-25: This needs to come before the subroutine
6591 call check below as on some targets return trampolines look
6592 like subroutine calls (MIPS16 return thunks). */
6593 if (gdbarch_in_solib_return_trampoline (gdbarch,
6594 stop_pc, ecs->stop_func_name)
6595 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6597 /* Determine where this trampoline returns. */
6598 CORE_ADDR real_stop_pc;
6600 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6603 fprintf_unfiltered (gdb_stdlog,
6604 "infrun: stepped into solib return tramp\n");
6606 /* Only proceed through if we know where it's going. */
6609 /* And put the step-breakpoint there and go until there. */
6610 symtab_and_line sr_sal;
6611 sr_sal.pc = real_stop_pc;
6612 sr_sal.section = find_pc_overlay (sr_sal.pc);
6613 sr_sal.pspace = get_frame_program_space (frame);
6615 /* Do not specify what the fp should be when we stop since
6616 on some machines the prologue is where the new fp value
6618 insert_step_resume_breakpoint_at_sal (gdbarch,
6619 sr_sal, null_frame_id);
6621 /* Restart without fiddling with the step ranges or
6628 /* Check for subroutine calls. The check for the current frame
6629 equalling the step ID is not necessary - the check of the
6630 previous frame's ID is sufficient - but it is a common case and
6631 cheaper than checking the previous frame's ID.
6633 NOTE: frame_id_eq will never report two invalid frame IDs as
6634 being equal, so to get into this block, both the current and
6635 previous frame must have valid frame IDs. */
6636 /* The outer_frame_id check is a heuristic to detect stepping
6637 through startup code. If we step over an instruction which
6638 sets the stack pointer from an invalid value to a valid value,
6639 we may detect that as a subroutine call from the mythical
6640 "outermost" function. This could be fixed by marking
6641 outermost frames as !stack_p,code_p,special_p. Then the
6642 initial outermost frame, before sp was valid, would
6643 have code_addr == &_start. See the comment in frame_id_eq
6645 if (!frame_id_eq (get_stack_frame_id (frame),
6646 ecs->event_thread->control.step_stack_frame_id)
6647 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6648 ecs->event_thread->control.step_stack_frame_id)
6649 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6651 || (ecs->event_thread->control.step_start_function
6652 != find_pc_function (stop_pc)))))
6654 CORE_ADDR real_stop_pc;
6657 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6659 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6661 /* I presume that step_over_calls is only 0 when we're
6662 supposed to be stepping at the assembly language level
6663 ("stepi"). Just stop. */
6664 /* And this works the same backward as frontward. MVS */
6665 end_stepping_range (ecs);
6669 /* Reverse stepping through solib trampolines. */
6671 if (execution_direction == EXEC_REVERSE
6672 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6673 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6674 || (ecs->stop_func_start == 0
6675 && in_solib_dynsym_resolve_code (stop_pc))))
6677 /* Any solib trampoline code can be handled in reverse
6678 by simply continuing to single-step. We have already
6679 executed the solib function (backwards), and a few
6680 steps will take us back through the trampoline to the
6686 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6688 /* We're doing a "next".
6690 Normal (forward) execution: set a breakpoint at the
6691 callee's return address (the address at which the caller
6694 Reverse (backward) execution. set the step-resume
6695 breakpoint at the start of the function that we just
6696 stepped into (backwards), and continue to there. When we
6697 get there, we'll need to single-step back to the caller. */
6699 if (execution_direction == EXEC_REVERSE)
6701 /* If we're already at the start of the function, we've either
6702 just stepped backward into a single instruction function,
6703 or stepped back out of a signal handler to the first instruction
6704 of the function. Just keep going, which will single-step back
6706 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6708 /* Normal function call return (static or dynamic). */
6709 symtab_and_line sr_sal;
6710 sr_sal.pc = ecs->stop_func_start;
6711 sr_sal.pspace = get_frame_program_space (frame);
6712 insert_step_resume_breakpoint_at_sal (gdbarch,
6713 sr_sal, null_frame_id);
6717 insert_step_resume_breakpoint_at_caller (frame);
6723 /* If we are in a function call trampoline (a stub between the
6724 calling routine and the real function), locate the real
6725 function. That's what tells us (a) whether we want to step
6726 into it at all, and (b) what prologue we want to run to the
6727 end of, if we do step into it. */
6728 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6729 if (real_stop_pc == 0)
6730 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6731 if (real_stop_pc != 0)
6732 ecs->stop_func_start = real_stop_pc;
6734 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6736 symtab_and_line sr_sal;
6737 sr_sal.pc = ecs->stop_func_start;
6738 sr_sal.pspace = get_frame_program_space (frame);
6740 insert_step_resume_breakpoint_at_sal (gdbarch,
6741 sr_sal, null_frame_id);
6746 /* If we have line number information for the function we are
6747 thinking of stepping into and the function isn't on the skip
6750 If there are several symtabs at that PC (e.g. with include
6751 files), just want to know whether *any* of them have line
6752 numbers. find_pc_line handles this. */
6754 struct symtab_and_line tmp_sal;
6756 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6757 if (tmp_sal.line != 0
6758 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6761 if (execution_direction == EXEC_REVERSE)
6762 handle_step_into_function_backward (gdbarch, ecs);
6764 handle_step_into_function (gdbarch, ecs);
6769 /* If we have no line number and the step-stop-if-no-debug is
6770 set, we stop the step so that the user has a chance to switch
6771 in assembly mode. */
6772 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6773 && step_stop_if_no_debug)
6775 end_stepping_range (ecs);
6779 if (execution_direction == EXEC_REVERSE)
6781 /* If we're already at the start of the function, we've either just
6782 stepped backward into a single instruction function without line
6783 number info, or stepped back out of a signal handler to the first
6784 instruction of the function without line number info. Just keep
6785 going, which will single-step back to the caller. */
6786 if (ecs->stop_func_start != stop_pc)
6788 /* Set a breakpoint at callee's start address.
6789 From there we can step once and be back in the caller. */
6790 symtab_and_line sr_sal;
6791 sr_sal.pc = ecs->stop_func_start;
6792 sr_sal.pspace = get_frame_program_space (frame);
6793 insert_step_resume_breakpoint_at_sal (gdbarch,
6794 sr_sal, null_frame_id);
6798 /* Set a breakpoint at callee's return address (the address
6799 at which the caller will resume). */
6800 insert_step_resume_breakpoint_at_caller (frame);
6806 /* Reverse stepping through solib trampolines. */
6808 if (execution_direction == EXEC_REVERSE
6809 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6811 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6812 || (ecs->stop_func_start == 0
6813 && in_solib_dynsym_resolve_code (stop_pc)))
6815 /* Any solib trampoline code can be handled in reverse
6816 by simply continuing to single-step. We have already
6817 executed the solib function (backwards), and a few
6818 steps will take us back through the trampoline to the
6823 else if (in_solib_dynsym_resolve_code (stop_pc))
6825 /* Stepped backward into the solib dynsym resolver.
6826 Set a breakpoint at its start and continue, then
6827 one more step will take us out. */
6828 symtab_and_line sr_sal;
6829 sr_sal.pc = ecs->stop_func_start;
6830 sr_sal.pspace = get_frame_program_space (frame);
6831 insert_step_resume_breakpoint_at_sal (gdbarch,
6832 sr_sal, null_frame_id);
6838 stop_pc_sal = find_pc_line (stop_pc, 0);
6840 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6841 the trampoline processing logic, however, there are some trampolines
6842 that have no names, so we should do trampoline handling first. */
6843 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6844 && ecs->stop_func_name == NULL
6845 && stop_pc_sal.line == 0)
6848 fprintf_unfiltered (gdb_stdlog,
6849 "infrun: stepped into undebuggable function\n");
6851 /* The inferior just stepped into, or returned to, an
6852 undebuggable function (where there is no debugging information
6853 and no line number corresponding to the address where the
6854 inferior stopped). Since we want to skip this kind of code,
6855 we keep going until the inferior returns from this
6856 function - unless the user has asked us not to (via
6857 set step-mode) or we no longer know how to get back
6858 to the call site. */
6859 if (step_stop_if_no_debug
6860 || !frame_id_p (frame_unwind_caller_id (frame)))
6862 /* If we have no line number and the step-stop-if-no-debug
6863 is set, we stop the step so that the user has a chance to
6864 switch in assembly mode. */
6865 end_stepping_range (ecs);
6870 /* Set a breakpoint at callee's return address (the address
6871 at which the caller will resume). */
6872 insert_step_resume_breakpoint_at_caller (frame);
6878 if (ecs->event_thread->control.step_range_end == 1)
6880 /* It is stepi or nexti. We always want to stop stepping after
6883 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6884 end_stepping_range (ecs);
6888 if (stop_pc_sal.line == 0)
6890 /* We have no line number information. That means to stop
6891 stepping (does this always happen right after one instruction,
6892 when we do "s" in a function with no line numbers,
6893 or can this happen as a result of a return or longjmp?). */
6895 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6896 end_stepping_range (ecs);
6900 /* Look for "calls" to inlined functions, part one. If the inline
6901 frame machinery detected some skipped call sites, we have entered
6902 a new inline function. */
6904 if (frame_id_eq (get_frame_id (get_current_frame ()),
6905 ecs->event_thread->control.step_frame_id)
6906 && inline_skipped_frames (ecs->ptid))
6909 fprintf_unfiltered (gdb_stdlog,
6910 "infrun: stepped into inlined function\n");
6912 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6914 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6916 /* For "step", we're going to stop. But if the call site
6917 for this inlined function is on the same source line as
6918 we were previously stepping, go down into the function
6919 first. Otherwise stop at the call site. */
6921 if (call_sal.line == ecs->event_thread->current_line
6922 && call_sal.symtab == ecs->event_thread->current_symtab)
6923 step_into_inline_frame (ecs->ptid);
6925 end_stepping_range (ecs);
6930 /* For "next", we should stop at the call site if it is on a
6931 different source line. Otherwise continue through the
6932 inlined function. */
6933 if (call_sal.line == ecs->event_thread->current_line
6934 && call_sal.symtab == ecs->event_thread->current_symtab)
6937 end_stepping_range (ecs);
6942 /* Look for "calls" to inlined functions, part two. If we are still
6943 in the same real function we were stepping through, but we have
6944 to go further up to find the exact frame ID, we are stepping
6945 through a more inlined call beyond its call site. */
6947 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6948 && !frame_id_eq (get_frame_id (get_current_frame ()),
6949 ecs->event_thread->control.step_frame_id)
6950 && stepped_in_from (get_current_frame (),
6951 ecs->event_thread->control.step_frame_id))
6954 fprintf_unfiltered (gdb_stdlog,
6955 "infrun: stepping through inlined function\n");
6957 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6960 end_stepping_range (ecs);
6964 if ((stop_pc == stop_pc_sal.pc)
6965 && (ecs->event_thread->current_line != stop_pc_sal.line
6966 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6968 /* We are at the start of a different line. So stop. Note that
6969 we don't stop if we step into the middle of a different line.
6970 That is said to make things like for (;;) statements work
6973 fprintf_unfiltered (gdb_stdlog,
6974 "infrun: stepped to a different line\n");
6975 end_stepping_range (ecs);
6979 /* We aren't done stepping.
6981 Optimize by setting the stepping range to the line.
6982 (We might not be in the original line, but if we entered a
6983 new line in mid-statement, we continue stepping. This makes
6984 things like for(;;) statements work better.) */
6986 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6987 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6988 ecs->event_thread->control.may_range_step = 1;
6989 set_step_info (frame, stop_pc_sal);
6992 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6996 /* In all-stop mode, if we're currently stepping but have stopped in
6997 some other thread, we may need to switch back to the stepped
6998 thread. Returns true we set the inferior running, false if we left
6999 it stopped (and the event needs further processing). */
7002 switch_back_to_stepped_thread (struct execution_control_state *ecs)
7004 if (!target_is_non_stop_p ())
7006 struct thread_info *tp;
7007 struct thread_info *stepping_thread;
7009 /* If any thread is blocked on some internal breakpoint, and we
7010 simply need to step over that breakpoint to get it going
7011 again, do that first. */
7013 /* However, if we see an event for the stepping thread, then we
7014 know all other threads have been moved past their breakpoints
7015 already. Let the caller check whether the step is finished,
7016 etc., before deciding to move it past a breakpoint. */
7017 if (ecs->event_thread->control.step_range_end != 0)
7020 /* Check if the current thread is blocked on an incomplete
7021 step-over, interrupted by a random signal. */
7022 if (ecs->event_thread->control.trap_expected
7023 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7027 fprintf_unfiltered (gdb_stdlog,
7028 "infrun: need to finish step-over of [%s]\n",
7029 target_pid_to_str (ecs->event_thread->ptid));
7035 /* Check if the current thread is blocked by a single-step
7036 breakpoint of another thread. */
7037 if (ecs->hit_singlestep_breakpoint)
7041 fprintf_unfiltered (gdb_stdlog,
7042 "infrun: need to step [%s] over single-step "
7044 target_pid_to_str (ecs->ptid));
7050 /* If this thread needs yet another step-over (e.g., stepping
7051 through a delay slot), do it first before moving on to
7053 if (thread_still_needs_step_over (ecs->event_thread))
7057 fprintf_unfiltered (gdb_stdlog,
7058 "infrun: thread [%s] still needs step-over\n",
7059 target_pid_to_str (ecs->event_thread->ptid));
7065 /* If scheduler locking applies even if not stepping, there's no
7066 need to walk over threads. Above we've checked whether the
7067 current thread is stepping. If some other thread not the
7068 event thread is stepping, then it must be that scheduler
7069 locking is not in effect. */
7070 if (schedlock_applies (ecs->event_thread))
7073 /* Otherwise, we no longer expect a trap in the current thread.
7074 Clear the trap_expected flag before switching back -- this is
7075 what keep_going does as well, if we call it. */
7076 ecs->event_thread->control.trap_expected = 0;
7078 /* Likewise, clear the signal if it should not be passed. */
7079 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7080 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7082 /* Do all pending step-overs before actually proceeding with
7084 if (start_step_over ())
7086 prepare_to_wait (ecs);
7090 /* Look for the stepping/nexting thread. */
7091 stepping_thread = NULL;
7093 ALL_NON_EXITED_THREADS (tp)
7095 /* Ignore threads of processes the caller is not
7098 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
7101 /* When stepping over a breakpoint, we lock all threads
7102 except the one that needs to move past the breakpoint.
7103 If a non-event thread has this set, the "incomplete
7104 step-over" check above should have caught it earlier. */
7105 if (tp->control.trap_expected)
7107 internal_error (__FILE__, __LINE__,
7108 "[%s] has inconsistent state: "
7109 "trap_expected=%d\n",
7110 target_pid_to_str (tp->ptid),
7111 tp->control.trap_expected);
7114 /* Did we find the stepping thread? */
7115 if (tp->control.step_range_end)
7117 /* Yep. There should only one though. */
7118 gdb_assert (stepping_thread == NULL);
7120 /* The event thread is handled at the top, before we
7122 gdb_assert (tp != ecs->event_thread);
7124 /* If some thread other than the event thread is
7125 stepping, then scheduler locking can't be in effect,
7126 otherwise we wouldn't have resumed the current event
7127 thread in the first place. */
7128 gdb_assert (!schedlock_applies (tp));
7130 stepping_thread = tp;
7134 if (stepping_thread != NULL)
7137 fprintf_unfiltered (gdb_stdlog,
7138 "infrun: switching back to stepped thread\n");
7140 if (keep_going_stepped_thread (stepping_thread))
7142 prepare_to_wait (ecs);
7151 /* Set a previously stepped thread back to stepping. Returns true on
7152 success, false if the resume is not possible (e.g., the thread
7156 keep_going_stepped_thread (struct thread_info *tp)
7158 struct frame_info *frame;
7159 struct execution_control_state ecss;
7160 struct execution_control_state *ecs = &ecss;
7162 /* If the stepping thread exited, then don't try to switch back and
7163 resume it, which could fail in several different ways depending
7164 on the target. Instead, just keep going.
7166 We can find a stepping dead thread in the thread list in two
7169 - The target supports thread exit events, and when the target
7170 tries to delete the thread from the thread list, inferior_ptid
7171 pointed at the exiting thread. In such case, calling
7172 delete_thread does not really remove the thread from the list;
7173 instead, the thread is left listed, with 'exited' state.
7175 - The target's debug interface does not support thread exit
7176 events, and so we have no idea whatsoever if the previously
7177 stepping thread is still alive. For that reason, we need to
7178 synchronously query the target now. */
7180 if (is_exited (tp->ptid)
7181 || !target_thread_alive (tp->ptid))
7184 fprintf_unfiltered (gdb_stdlog,
7185 "infrun: not resuming previously "
7186 "stepped thread, it has vanished\n");
7188 delete_thread (tp->ptid);
7193 fprintf_unfiltered (gdb_stdlog,
7194 "infrun: resuming previously stepped thread\n");
7196 reset_ecs (ecs, tp);
7197 switch_to_thread (tp->ptid);
7199 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7200 frame = get_current_frame ();
7202 /* If the PC of the thread we were trying to single-step has
7203 changed, then that thread has trapped or been signaled, but the
7204 event has not been reported to GDB yet. Re-poll the target
7205 looking for this particular thread's event (i.e. temporarily
7206 enable schedlock) by:
7208 - setting a break at the current PC
7209 - resuming that particular thread, only (by setting trap
7212 This prevents us continuously moving the single-step breakpoint
7213 forward, one instruction at a time, overstepping. */
7215 if (stop_pc != tp->prev_pc)
7220 fprintf_unfiltered (gdb_stdlog,
7221 "infrun: expected thread advanced also (%s -> %s)\n",
7222 paddress (target_gdbarch (), tp->prev_pc),
7223 paddress (target_gdbarch (), stop_pc));
7225 /* Clear the info of the previous step-over, as it's no longer
7226 valid (if the thread was trying to step over a breakpoint, it
7227 has already succeeded). It's what keep_going would do too,
7228 if we called it. Do this before trying to insert the sss
7229 breakpoint, otherwise if we were previously trying to step
7230 over this exact address in another thread, the breakpoint is
7232 clear_step_over_info ();
7233 tp->control.trap_expected = 0;
7235 insert_single_step_breakpoint (get_frame_arch (frame),
7236 get_frame_address_space (frame),
7240 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7241 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7246 fprintf_unfiltered (gdb_stdlog,
7247 "infrun: expected thread still hasn't advanced\n");
7249 keep_going_pass_signal (ecs);
7254 /* Is thread TP in the middle of (software or hardware)
7255 single-stepping? (Note the result of this function must never be
7256 passed directly as target_resume's STEP parameter.) */
7259 currently_stepping (struct thread_info *tp)
7261 return ((tp->control.step_range_end
7262 && tp->control.step_resume_breakpoint == NULL)
7263 || tp->control.trap_expected
7264 || tp->stepped_breakpoint
7265 || bpstat_should_step ());
7268 /* Inferior has stepped into a subroutine call with source code that
7269 we should not step over. Do step to the first line of code in
7273 handle_step_into_function (struct gdbarch *gdbarch,
7274 struct execution_control_state *ecs)
7276 fill_in_stop_func (gdbarch, ecs);
7278 compunit_symtab *cust = find_pc_compunit_symtab (stop_pc);
7279 if (cust != NULL && compunit_language (cust) != language_asm)
7280 ecs->stop_func_start
7281 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7283 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7284 /* Use the step_resume_break to step until the end of the prologue,
7285 even if that involves jumps (as it seems to on the vax under
7287 /* If the prologue ends in the middle of a source line, continue to
7288 the end of that source line (if it is still within the function).
7289 Otherwise, just go to end of prologue. */
7290 if (stop_func_sal.end
7291 && stop_func_sal.pc != ecs->stop_func_start
7292 && stop_func_sal.end < ecs->stop_func_end)
7293 ecs->stop_func_start = stop_func_sal.end;
7295 /* Architectures which require breakpoint adjustment might not be able
7296 to place a breakpoint at the computed address. If so, the test
7297 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7298 ecs->stop_func_start to an address at which a breakpoint may be
7299 legitimately placed.
7301 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7302 made, GDB will enter an infinite loop when stepping through
7303 optimized code consisting of VLIW instructions which contain
7304 subinstructions corresponding to different source lines. On
7305 FR-V, it's not permitted to place a breakpoint on any but the
7306 first subinstruction of a VLIW instruction. When a breakpoint is
7307 set, GDB will adjust the breakpoint address to the beginning of
7308 the VLIW instruction. Thus, we need to make the corresponding
7309 adjustment here when computing the stop address. */
7311 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7313 ecs->stop_func_start
7314 = gdbarch_adjust_breakpoint_address (gdbarch,
7315 ecs->stop_func_start);
7318 if (ecs->stop_func_start == stop_pc)
7320 /* We are already there: stop now. */
7321 end_stepping_range (ecs);
7326 /* Put the step-breakpoint there and go until there. */
7327 symtab_and_line sr_sal;
7328 sr_sal.pc = ecs->stop_func_start;
7329 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7330 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7332 /* Do not specify what the fp should be when we stop since on
7333 some machines the prologue is where the new fp value is
7335 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7337 /* And make sure stepping stops right away then. */
7338 ecs->event_thread->control.step_range_end
7339 = ecs->event_thread->control.step_range_start;
7344 /* Inferior has stepped backward into a subroutine call with source
7345 code that we should not step over. Do step to the beginning of the
7346 last line of code in it. */
7349 handle_step_into_function_backward (struct gdbarch *gdbarch,
7350 struct execution_control_state *ecs)
7352 struct compunit_symtab *cust;
7353 struct symtab_and_line stop_func_sal;
7355 fill_in_stop_func (gdbarch, ecs);
7357 cust = find_pc_compunit_symtab (stop_pc);
7358 if (cust != NULL && compunit_language (cust) != language_asm)
7359 ecs->stop_func_start
7360 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7362 stop_func_sal = find_pc_line (stop_pc, 0);
7364 /* OK, we're just going to keep stepping here. */
7365 if (stop_func_sal.pc == stop_pc)
7367 /* We're there already. Just stop stepping now. */
7368 end_stepping_range (ecs);
7372 /* Else just reset the step range and keep going.
7373 No step-resume breakpoint, they don't work for
7374 epilogues, which can have multiple entry paths. */
7375 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7376 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7382 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7383 This is used to both functions and to skip over code. */
7386 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7387 struct symtab_and_line sr_sal,
7388 struct frame_id sr_id,
7389 enum bptype sr_type)
7391 /* There should never be more than one step-resume or longjmp-resume
7392 breakpoint per thread, so we should never be setting a new
7393 step_resume_breakpoint when one is already active. */
7394 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7395 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7398 fprintf_unfiltered (gdb_stdlog,
7399 "infrun: inserting step-resume breakpoint at %s\n",
7400 paddress (gdbarch, sr_sal.pc));
7402 inferior_thread ()->control.step_resume_breakpoint
7403 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7407 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7408 struct symtab_and_line sr_sal,
7409 struct frame_id sr_id)
7411 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7416 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7417 This is used to skip a potential signal handler.
7419 This is called with the interrupted function's frame. The signal
7420 handler, when it returns, will resume the interrupted function at
7424 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7426 gdb_assert (return_frame != NULL);
7428 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7430 symtab_and_line sr_sal;
7431 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7432 sr_sal.section = find_pc_overlay (sr_sal.pc);
7433 sr_sal.pspace = get_frame_program_space (return_frame);
7435 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7436 get_stack_frame_id (return_frame),
7440 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7441 is used to skip a function after stepping into it (for "next" or if
7442 the called function has no debugging information).
7444 The current function has almost always been reached by single
7445 stepping a call or return instruction. NEXT_FRAME belongs to the
7446 current function, and the breakpoint will be set at the caller's
7449 This is a separate function rather than reusing
7450 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7451 get_prev_frame, which may stop prematurely (see the implementation
7452 of frame_unwind_caller_id for an example). */
7455 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7457 /* We shouldn't have gotten here if we don't know where the call site
7459 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7461 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7463 symtab_and_line sr_sal;
7464 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7465 frame_unwind_caller_pc (next_frame));
7466 sr_sal.section = find_pc_overlay (sr_sal.pc);
7467 sr_sal.pspace = frame_unwind_program_space (next_frame);
7469 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7470 frame_unwind_caller_id (next_frame));
7473 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7474 new breakpoint at the target of a jmp_buf. The handling of
7475 longjmp-resume uses the same mechanisms used for handling
7476 "step-resume" breakpoints. */
7479 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7481 /* There should never be more than one longjmp-resume breakpoint per
7482 thread, so we should never be setting a new
7483 longjmp_resume_breakpoint when one is already active. */
7484 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7487 fprintf_unfiltered (gdb_stdlog,
7488 "infrun: inserting longjmp-resume breakpoint at %s\n",
7489 paddress (gdbarch, pc));
7491 inferior_thread ()->control.exception_resume_breakpoint =
7492 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7495 /* Insert an exception resume breakpoint. TP is the thread throwing
7496 the exception. The block B is the block of the unwinder debug hook
7497 function. FRAME is the frame corresponding to the call to this
7498 function. SYM is the symbol of the function argument holding the
7499 target PC of the exception. */
7502 insert_exception_resume_breakpoint (struct thread_info *tp,
7503 const struct block *b,
7504 struct frame_info *frame,
7509 struct block_symbol vsym;
7510 struct value *value;
7512 struct breakpoint *bp;
7514 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
7515 value = read_var_value (vsym.symbol, vsym.block, frame);
7516 /* If the value was optimized out, revert to the old behavior. */
7517 if (! value_optimized_out (value))
7519 handler = value_as_address (value);
7522 fprintf_unfiltered (gdb_stdlog,
7523 "infrun: exception resume at %lx\n",
7524 (unsigned long) handler);
7526 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7528 bp_exception_resume).release ();
7530 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7533 bp->thread = tp->global_num;
7534 inferior_thread ()->control.exception_resume_breakpoint = bp;
7537 CATCH (e, RETURN_MASK_ERROR)
7539 /* We want to ignore errors here. */
7544 /* A helper for check_exception_resume that sets an
7545 exception-breakpoint based on a SystemTap probe. */
7548 insert_exception_resume_from_probe (struct thread_info *tp,
7549 const struct bound_probe *probe,
7550 struct frame_info *frame)
7552 struct value *arg_value;
7554 struct breakpoint *bp;
7556 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7560 handler = value_as_address (arg_value);
7563 fprintf_unfiltered (gdb_stdlog,
7564 "infrun: exception resume at %s\n",
7565 paddress (get_objfile_arch (probe->objfile),
7568 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7569 handler, bp_exception_resume).release ();
7570 bp->thread = tp->global_num;
7571 inferior_thread ()->control.exception_resume_breakpoint = bp;
7574 /* This is called when an exception has been intercepted. Check to
7575 see whether the exception's destination is of interest, and if so,
7576 set an exception resume breakpoint there. */
7579 check_exception_resume (struct execution_control_state *ecs,
7580 struct frame_info *frame)
7582 struct bound_probe probe;
7583 struct symbol *func;
7585 /* First see if this exception unwinding breakpoint was set via a
7586 SystemTap probe point. If so, the probe has two arguments: the
7587 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7588 set a breakpoint there. */
7589 probe = find_probe_by_pc (get_frame_pc (frame));
7592 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7596 func = get_frame_function (frame);
7602 const struct block *b;
7603 struct block_iterator iter;
7607 /* The exception breakpoint is a thread-specific breakpoint on
7608 the unwinder's debug hook, declared as:
7610 void _Unwind_DebugHook (void *cfa, void *handler);
7612 The CFA argument indicates the frame to which control is
7613 about to be transferred. HANDLER is the destination PC.
7615 We ignore the CFA and set a temporary breakpoint at HANDLER.
7616 This is not extremely efficient but it avoids issues in gdb
7617 with computing the DWARF CFA, and it also works even in weird
7618 cases such as throwing an exception from inside a signal
7621 b = SYMBOL_BLOCK_VALUE (func);
7622 ALL_BLOCK_SYMBOLS (b, iter, sym)
7624 if (!SYMBOL_IS_ARGUMENT (sym))
7631 insert_exception_resume_breakpoint (ecs->event_thread,
7637 CATCH (e, RETURN_MASK_ERROR)
7644 stop_waiting (struct execution_control_state *ecs)
7647 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7649 /* Let callers know we don't want to wait for the inferior anymore. */
7650 ecs->wait_some_more = 0;
7652 /* If all-stop, but the target is always in non-stop mode, stop all
7653 threads now that we're presenting the stop to the user. */
7654 if (!non_stop && target_is_non_stop_p ())
7655 stop_all_threads ();
7658 /* Like keep_going, but passes the signal to the inferior, even if the
7659 signal is set to nopass. */
7662 keep_going_pass_signal (struct execution_control_state *ecs)
7664 /* Make sure normal_stop is called if we get a QUIT handled before
7666 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7668 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7669 gdb_assert (!ecs->event_thread->resumed);
7671 /* Save the pc before execution, to compare with pc after stop. */
7672 ecs->event_thread->prev_pc
7673 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7675 if (ecs->event_thread->control.trap_expected)
7677 struct thread_info *tp = ecs->event_thread;
7680 fprintf_unfiltered (gdb_stdlog,
7681 "infrun: %s has trap_expected set, "
7682 "resuming to collect trap\n",
7683 target_pid_to_str (tp->ptid));
7685 /* We haven't yet gotten our trap, and either: intercepted a
7686 non-signal event (e.g., a fork); or took a signal which we
7687 are supposed to pass through to the inferior. Simply
7689 discard_cleanups (old_cleanups);
7690 resume (ecs->event_thread->suspend.stop_signal);
7692 else if (step_over_info_valid_p ())
7694 /* Another thread is stepping over a breakpoint in-line. If
7695 this thread needs a step-over too, queue the request. In
7696 either case, this resume must be deferred for later. */
7697 struct thread_info *tp = ecs->event_thread;
7699 if (ecs->hit_singlestep_breakpoint
7700 || thread_still_needs_step_over (tp))
7703 fprintf_unfiltered (gdb_stdlog,
7704 "infrun: step-over already in progress: "
7705 "step-over for %s deferred\n",
7706 target_pid_to_str (tp->ptid));
7707 thread_step_over_chain_enqueue (tp);
7712 fprintf_unfiltered (gdb_stdlog,
7713 "infrun: step-over in progress: "
7714 "resume of %s deferred\n",
7715 target_pid_to_str (tp->ptid));
7718 discard_cleanups (old_cleanups);
7722 struct regcache *regcache = get_current_regcache ();
7725 step_over_what step_what;
7727 /* Either the trap was not expected, but we are continuing
7728 anyway (if we got a signal, the user asked it be passed to
7731 We got our expected trap, but decided we should resume from
7734 We're going to run this baby now!
7736 Note that insert_breakpoints won't try to re-insert
7737 already inserted breakpoints. Therefore, we don't
7738 care if breakpoints were already inserted, or not. */
7740 /* If we need to step over a breakpoint, and we're not using
7741 displaced stepping to do so, insert all breakpoints
7742 (watchpoints, etc.) but the one we're stepping over, step one
7743 instruction, and then re-insert the breakpoint when that step
7746 step_what = thread_still_needs_step_over (ecs->event_thread);
7748 remove_bp = (ecs->hit_singlestep_breakpoint
7749 || (step_what & STEP_OVER_BREAKPOINT));
7750 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7752 /* We can't use displaced stepping if we need to step past a
7753 watchpoint. The instruction copied to the scratch pad would
7754 still trigger the watchpoint. */
7756 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7758 set_step_over_info (regcache->aspace (),
7759 regcache_read_pc (regcache), remove_wps,
7760 ecs->event_thread->global_num);
7762 else if (remove_wps)
7763 set_step_over_info (NULL, 0, remove_wps, -1);
7765 /* If we now need to do an in-line step-over, we need to stop
7766 all other threads. Note this must be done before
7767 insert_breakpoints below, because that removes the breakpoint
7768 we're about to step over, otherwise other threads could miss
7770 if (step_over_info_valid_p () && target_is_non_stop_p ())
7771 stop_all_threads ();
7773 /* Stop stepping if inserting breakpoints fails. */
7776 insert_breakpoints ();
7778 CATCH (e, RETURN_MASK_ERROR)
7780 exception_print (gdb_stderr, e);
7782 discard_cleanups (old_cleanups);
7787 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7789 discard_cleanups (old_cleanups);
7790 resume (ecs->event_thread->suspend.stop_signal);
7793 prepare_to_wait (ecs);
7796 /* Called when we should continue running the inferior, because the
7797 current event doesn't cause a user visible stop. This does the
7798 resuming part; waiting for the next event is done elsewhere. */
7801 keep_going (struct execution_control_state *ecs)
7803 if (ecs->event_thread->control.trap_expected
7804 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7805 ecs->event_thread->control.trap_expected = 0;
7807 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7808 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7809 keep_going_pass_signal (ecs);
7812 /* This function normally comes after a resume, before
7813 handle_inferior_event exits. It takes care of any last bits of
7814 housekeeping, and sets the all-important wait_some_more flag. */
7817 prepare_to_wait (struct execution_control_state *ecs)
7820 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7822 ecs->wait_some_more = 1;
7824 if (!target_is_async_p ())
7825 mark_infrun_async_event_handler ();
7828 /* We are done with the step range of a step/next/si/ni command.
7829 Called once for each n of a "step n" operation. */
7832 end_stepping_range (struct execution_control_state *ecs)
7834 ecs->event_thread->control.stop_step = 1;
7838 /* Several print_*_reason functions to print why the inferior has stopped.
7839 We always print something when the inferior exits, or receives a signal.
7840 The rest of the cases are dealt with later on in normal_stop and
7841 print_it_typical. Ideally there should be a call to one of these
7842 print_*_reason functions functions from handle_inferior_event each time
7843 stop_waiting is called.
7845 Note that we don't call these directly, instead we delegate that to
7846 the interpreters, through observers. Interpreters then call these
7847 with whatever uiout is right. */
7850 print_end_stepping_range_reason (struct ui_out *uiout)
7852 /* For CLI-like interpreters, print nothing. */
7854 if (uiout->is_mi_like_p ())
7856 uiout->field_string ("reason",
7857 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7862 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7864 annotate_signalled ();
7865 if (uiout->is_mi_like_p ())
7867 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7868 uiout->text ("\nProgram terminated with signal ");
7869 annotate_signal_name ();
7870 uiout->field_string ("signal-name",
7871 gdb_signal_to_name (siggnal));
7872 annotate_signal_name_end ();
7874 annotate_signal_string ();
7875 uiout->field_string ("signal-meaning",
7876 gdb_signal_to_string (siggnal));
7877 annotate_signal_string_end ();
7878 uiout->text (".\n");
7879 uiout->text ("The program no longer exists.\n");
7883 print_exited_reason (struct ui_out *uiout, int exitstatus)
7885 struct inferior *inf = current_inferior ();
7886 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7888 annotate_exited (exitstatus);
7891 if (uiout->is_mi_like_p ())
7892 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7893 uiout->text ("[Inferior ");
7894 uiout->text (plongest (inf->num));
7896 uiout->text (pidstr);
7897 uiout->text (") exited with code ");
7898 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7899 uiout->text ("]\n");
7903 if (uiout->is_mi_like_p ())
7905 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7906 uiout->text ("[Inferior ");
7907 uiout->text (plongest (inf->num));
7909 uiout->text (pidstr);
7910 uiout->text (") exited normally]\n");
7914 /* Some targets/architectures can do extra processing/display of
7915 segmentation faults. E.g., Intel MPX boundary faults.
7916 Call the architecture dependent function to handle the fault. */
7919 handle_segmentation_fault (struct ui_out *uiout)
7921 struct regcache *regcache = get_current_regcache ();
7922 struct gdbarch *gdbarch = regcache->arch ();
7924 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7925 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7929 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7931 struct thread_info *thr = inferior_thread ();
7935 if (uiout->is_mi_like_p ())
7937 else if (show_thread_that_caused_stop ())
7941 uiout->text ("\nThread ");
7942 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7944 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7947 uiout->text (" \"");
7948 uiout->field_fmt ("name", "%s", name);
7953 uiout->text ("\nProgram");
7955 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7956 uiout->text (" stopped");
7959 uiout->text (" received signal ");
7960 annotate_signal_name ();
7961 if (uiout->is_mi_like_p ())
7963 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7964 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7965 annotate_signal_name_end ();
7967 annotate_signal_string ();
7968 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7970 if (siggnal == GDB_SIGNAL_SEGV)
7971 handle_segmentation_fault (uiout);
7973 annotate_signal_string_end ();
7975 uiout->text (".\n");
7979 print_no_history_reason (struct ui_out *uiout)
7981 uiout->text ("\nNo more reverse-execution history.\n");
7984 /* Print current location without a level number, if we have changed
7985 functions or hit a breakpoint. Print source line if we have one.
7986 bpstat_print contains the logic deciding in detail what to print,
7987 based on the event(s) that just occurred. */
7990 print_stop_location (struct target_waitstatus *ws)
7993 enum print_what source_flag;
7994 int do_frame_printing = 1;
7995 struct thread_info *tp = inferior_thread ();
7997 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
8001 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8002 should) carry around the function and does (or should) use
8003 that when doing a frame comparison. */
8004 if (tp->control.stop_step
8005 && frame_id_eq (tp->control.step_frame_id,
8006 get_frame_id (get_current_frame ()))
8007 && tp->control.step_start_function == find_pc_function (stop_pc))
8009 /* Finished step, just print source line. */
8010 source_flag = SRC_LINE;
8014 /* Print location and source line. */
8015 source_flag = SRC_AND_LOC;
8018 case PRINT_SRC_AND_LOC:
8019 /* Print location and source line. */
8020 source_flag = SRC_AND_LOC;
8022 case PRINT_SRC_ONLY:
8023 source_flag = SRC_LINE;
8026 /* Something bogus. */
8027 source_flag = SRC_LINE;
8028 do_frame_printing = 0;
8031 internal_error (__FILE__, __LINE__, _("Unknown value."));
8034 /* The behavior of this routine with respect to the source
8036 SRC_LINE: Print only source line
8037 LOCATION: Print only location
8038 SRC_AND_LOC: Print location and source line. */
8039 if (do_frame_printing)
8040 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8046 print_stop_event (struct ui_out *uiout)
8048 struct target_waitstatus last;
8050 struct thread_info *tp;
8052 get_last_target_status (&last_ptid, &last);
8055 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8057 print_stop_location (&last);
8059 /* Display the auto-display expressions. */
8063 tp = inferior_thread ();
8064 if (tp->thread_fsm != NULL
8065 && thread_fsm_finished_p (tp->thread_fsm))
8067 struct return_value_info *rv;
8069 rv = thread_fsm_return_value (tp->thread_fsm);
8071 print_return_value (uiout, rv);
8078 maybe_remove_breakpoints (void)
8080 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8082 if (remove_breakpoints ())
8084 target_terminal::ours_for_output ();
8085 printf_filtered (_("Cannot remove breakpoints because "
8086 "program is no longer writable.\nFurther "
8087 "execution is probably impossible.\n"));
8092 /* The execution context that just caused a normal stop. */
8099 /* The event PTID. */
8103 /* If stopp for a thread event, this is the thread that caused the
8105 struct thread_info *thread;
8107 /* The inferior that caused the stop. */
8111 /* Returns a new stop context. If stopped for a thread event, this
8112 takes a strong reference to the thread. */
8114 static struct stop_context *
8115 save_stop_context (void)
8117 struct stop_context *sc = XNEW (struct stop_context);
8119 sc->stop_id = get_stop_id ();
8120 sc->ptid = inferior_ptid;
8121 sc->inf_num = current_inferior ()->num;
8123 if (!ptid_equal (inferior_ptid, null_ptid))
8125 /* Take a strong reference so that the thread can't be deleted
8127 sc->thread = inferior_thread ();
8128 sc->thread->incref ();
8136 /* Release a stop context previously created with save_stop_context.
8137 Releases the strong reference to the thread as well. */
8140 release_stop_context_cleanup (void *arg)
8142 struct stop_context *sc = (struct stop_context *) arg;
8144 if (sc->thread != NULL)
8145 sc->thread->decref ();
8149 /* Return true if the current context no longer matches the saved stop
8153 stop_context_changed (struct stop_context *prev)
8155 if (!ptid_equal (prev->ptid, inferior_ptid))
8157 if (prev->inf_num != current_inferior ()->num)
8159 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8161 if (get_stop_id () != prev->stop_id)
8171 struct target_waitstatus last;
8173 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
8176 get_last_target_status (&last_ptid, &last);
8180 /* If an exception is thrown from this point on, make sure to
8181 propagate GDB's knowledge of the executing state to the
8182 frontend/user running state. A QUIT is an easy exception to see
8183 here, so do this before any filtered output. */
8185 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
8186 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8187 || last.kind == TARGET_WAITKIND_EXITED)
8189 /* On some targets, we may still have live threads in the
8190 inferior when we get a process exit event. E.g., for
8191 "checkpoint", when the current checkpoint/fork exits,
8192 linux-fork.c automatically switches to another fork from
8193 within target_mourn_inferior. */
8194 if (!ptid_equal (inferior_ptid, null_ptid))
8196 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
8197 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
8200 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8201 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
8203 /* As we're presenting a stop, and potentially removing breakpoints,
8204 update the thread list so we can tell whether there are threads
8205 running on the target. With target remote, for example, we can
8206 only learn about new threads when we explicitly update the thread
8207 list. Do this before notifying the interpreters about signal
8208 stops, end of stepping ranges, etc., so that the "new thread"
8209 output is emitted before e.g., "Program received signal FOO",
8210 instead of after. */
8211 update_thread_list ();
8213 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8214 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
8216 /* As with the notification of thread events, we want to delay
8217 notifying the user that we've switched thread context until
8218 the inferior actually stops.
8220 There's no point in saying anything if the inferior has exited.
8221 Note that SIGNALLED here means "exited with a signal", not
8222 "received a signal".
8224 Also skip saying anything in non-stop mode. In that mode, as we
8225 don't want GDB to switch threads behind the user's back, to avoid
8226 races where the user is typing a command to apply to thread x,
8227 but GDB switches to thread y before the user finishes entering
8228 the command, fetch_inferior_event installs a cleanup to restore
8229 the current thread back to the thread the user had selected right
8230 after this event is handled, so we're not really switching, only
8231 informing of a stop. */
8233 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
8234 && target_has_execution
8235 && last.kind != TARGET_WAITKIND_SIGNALLED
8236 && last.kind != TARGET_WAITKIND_EXITED
8237 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8239 SWITCH_THRU_ALL_UIS ()
8241 target_terminal::ours_for_output ();
8242 printf_filtered (_("[Switching to %s]\n"),
8243 target_pid_to_str (inferior_ptid));
8244 annotate_thread_changed ();
8246 previous_inferior_ptid = inferior_ptid;
8249 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8251 SWITCH_THRU_ALL_UIS ()
8252 if (current_ui->prompt_state == PROMPT_BLOCKED)
8254 target_terminal::ours_for_output ();
8255 printf_filtered (_("No unwaited-for children left.\n"));
8259 /* Note: this depends on the update_thread_list call above. */
8260 maybe_remove_breakpoints ();
8262 /* If an auto-display called a function and that got a signal,
8263 delete that auto-display to avoid an infinite recursion. */
8265 if (stopped_by_random_signal)
8266 disable_current_display ();
8268 SWITCH_THRU_ALL_UIS ()
8270 async_enable_stdin ();
8273 /* Let the user/frontend see the threads as stopped. */
8274 do_cleanups (old_chain);
8276 /* Select innermost stack frame - i.e., current frame is frame 0,
8277 and current location is based on that. Handle the case where the
8278 dummy call is returning after being stopped. E.g. the dummy call
8279 previously hit a breakpoint. (If the dummy call returns
8280 normally, we won't reach here.) Do this before the stop hook is
8281 run, so that it doesn't get to see the temporary dummy frame,
8282 which is not where we'll present the stop. */
8283 if (has_stack_frames ())
8285 if (stop_stack_dummy == STOP_STACK_DUMMY)
8287 /* Pop the empty frame that contains the stack dummy. This
8288 also restores inferior state prior to the call (struct
8289 infcall_suspend_state). */
8290 struct frame_info *frame = get_current_frame ();
8292 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8294 /* frame_pop calls reinit_frame_cache as the last thing it
8295 does which means there's now no selected frame. */
8298 select_frame (get_current_frame ());
8300 /* Set the current source location. */
8301 set_current_sal_from_frame (get_current_frame ());
8304 /* Look up the hook_stop and run it (CLI internally handles problem
8305 of stop_command's pre-hook not existing). */
8306 if (stop_command != NULL)
8308 struct stop_context *saved_context = save_stop_context ();
8309 struct cleanup *old_chain
8310 = make_cleanup (release_stop_context_cleanup, saved_context);
8314 execute_cmd_pre_hook (stop_command);
8316 CATCH (ex, RETURN_MASK_ALL)
8318 exception_fprintf (gdb_stderr, ex,
8319 "Error while running hook_stop:\n");
8323 /* If the stop hook resumes the target, then there's no point in
8324 trying to notify about the previous stop; its context is
8325 gone. Likewise if the command switches thread or inferior --
8326 the observers would print a stop for the wrong
8328 if (stop_context_changed (saved_context))
8330 do_cleanups (old_chain);
8333 do_cleanups (old_chain);
8336 /* Notify observers about the stop. This is where the interpreters
8337 print the stop event. */
8338 if (!ptid_equal (inferior_ptid, null_ptid))
8339 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
8342 observer_notify_normal_stop (NULL, stop_print_frame);
8344 annotate_stopped ();
8346 if (target_has_execution)
8348 if (last.kind != TARGET_WAITKIND_SIGNALLED
8349 && last.kind != TARGET_WAITKIND_EXITED)
8350 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8351 Delete any breakpoint that is to be deleted at the next stop. */
8352 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8355 /* Try to get rid of automatically added inferiors that are no
8356 longer needed. Keeping those around slows down things linearly.
8357 Note that this never removes the current inferior. */
8364 signal_stop_state (int signo)
8366 return signal_stop[signo];
8370 signal_print_state (int signo)
8372 return signal_print[signo];
8376 signal_pass_state (int signo)
8378 return signal_program[signo];
8382 signal_cache_update (int signo)
8386 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8387 signal_cache_update (signo);
8392 signal_pass[signo] = (signal_stop[signo] == 0
8393 && signal_print[signo] == 0
8394 && signal_program[signo] == 1
8395 && signal_catch[signo] == 0);
8399 signal_stop_update (int signo, int state)
8401 int ret = signal_stop[signo];
8403 signal_stop[signo] = state;
8404 signal_cache_update (signo);
8409 signal_print_update (int signo, int state)
8411 int ret = signal_print[signo];
8413 signal_print[signo] = state;
8414 signal_cache_update (signo);
8419 signal_pass_update (int signo, int state)
8421 int ret = signal_program[signo];
8423 signal_program[signo] = state;
8424 signal_cache_update (signo);
8428 /* Update the global 'signal_catch' from INFO and notify the
8432 signal_catch_update (const unsigned int *info)
8436 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8437 signal_catch[i] = info[i] > 0;
8438 signal_cache_update (-1);
8439 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8443 sig_print_header (void)
8445 printf_filtered (_("Signal Stop\tPrint\tPass "
8446 "to program\tDescription\n"));
8450 sig_print_info (enum gdb_signal oursig)
8452 const char *name = gdb_signal_to_name (oursig);
8453 int name_padding = 13 - strlen (name);
8455 if (name_padding <= 0)
8458 printf_filtered ("%s", name);
8459 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8460 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8461 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8462 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8463 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8466 /* Specify how various signals in the inferior should be handled. */
8469 handle_command (const char *args, int from_tty)
8471 int digits, wordlen;
8472 int sigfirst, signum, siglast;
8473 enum gdb_signal oursig;
8476 unsigned char *sigs;
8480 error_no_arg (_("signal to handle"));
8483 /* Allocate and zero an array of flags for which signals to handle. */
8485 nsigs = (int) GDB_SIGNAL_LAST;
8486 sigs = (unsigned char *) alloca (nsigs);
8487 memset (sigs, 0, nsigs);
8489 /* Break the command line up into args. */
8491 gdb_argv built_argv (args);
8493 /* Walk through the args, looking for signal oursigs, signal names, and
8494 actions. Signal numbers and signal names may be interspersed with
8495 actions, with the actions being performed for all signals cumulatively
8496 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8498 for (char *arg : built_argv)
8500 wordlen = strlen (arg);
8501 for (digits = 0; isdigit (arg[digits]); digits++)
8505 sigfirst = siglast = -1;
8507 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8509 /* Apply action to all signals except those used by the
8510 debugger. Silently skip those. */
8513 siglast = nsigs - 1;
8515 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8517 SET_SIGS (nsigs, sigs, signal_stop);
8518 SET_SIGS (nsigs, sigs, signal_print);
8520 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8522 UNSET_SIGS (nsigs, sigs, signal_program);
8524 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8526 SET_SIGS (nsigs, sigs, signal_print);
8528 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8530 SET_SIGS (nsigs, sigs, signal_program);
8532 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8534 UNSET_SIGS (nsigs, sigs, signal_stop);
8536 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8538 SET_SIGS (nsigs, sigs, signal_program);
8540 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8542 UNSET_SIGS (nsigs, sigs, signal_print);
8543 UNSET_SIGS (nsigs, sigs, signal_stop);
8545 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8547 UNSET_SIGS (nsigs, sigs, signal_program);
8549 else if (digits > 0)
8551 /* It is numeric. The numeric signal refers to our own
8552 internal signal numbering from target.h, not to host/target
8553 signal number. This is a feature; users really should be
8554 using symbolic names anyway, and the common ones like
8555 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8557 sigfirst = siglast = (int)
8558 gdb_signal_from_command (atoi (arg));
8559 if (arg[digits] == '-')
8562 gdb_signal_from_command (atoi (arg + digits + 1));
8564 if (sigfirst > siglast)
8566 /* Bet he didn't figure we'd think of this case... */
8574 oursig = gdb_signal_from_name (arg);
8575 if (oursig != GDB_SIGNAL_UNKNOWN)
8577 sigfirst = siglast = (int) oursig;
8581 /* Not a number and not a recognized flag word => complain. */
8582 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8586 /* If any signal numbers or symbol names were found, set flags for
8587 which signals to apply actions to. */
8589 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8591 switch ((enum gdb_signal) signum)
8593 case GDB_SIGNAL_TRAP:
8594 case GDB_SIGNAL_INT:
8595 if (!allsigs && !sigs[signum])
8597 if (query (_("%s is used by the debugger.\n\
8598 Are you sure you want to change it? "),
8599 gdb_signal_to_name ((enum gdb_signal) signum)))
8605 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8606 gdb_flush (gdb_stdout);
8611 case GDB_SIGNAL_DEFAULT:
8612 case GDB_SIGNAL_UNKNOWN:
8613 /* Make sure that "all" doesn't print these. */
8622 for (signum = 0; signum < nsigs; signum++)
8625 signal_cache_update (-1);
8626 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8627 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8631 /* Show the results. */
8632 sig_print_header ();
8633 for (; signum < nsigs; signum++)
8635 sig_print_info ((enum gdb_signal) signum);
8642 /* Complete the "handle" command. */
8645 handle_completer (struct cmd_list_element *ignore,
8646 completion_tracker &tracker,
8647 const char *text, const char *word)
8649 static const char * const keywords[] =
8663 signal_completer (ignore, tracker, text, word);
8664 complete_on_enum (tracker, keywords, word, word);
8668 gdb_signal_from_command (int num)
8670 if (num >= 1 && num <= 15)
8671 return (enum gdb_signal) num;
8672 error (_("Only signals 1-15 are valid as numeric signals.\n\
8673 Use \"info signals\" for a list of symbolic signals."));
8676 /* Print current contents of the tables set by the handle command.
8677 It is possible we should just be printing signals actually used
8678 by the current target (but for things to work right when switching
8679 targets, all signals should be in the signal tables). */
8682 info_signals_command (char *signum_exp, int from_tty)
8684 enum gdb_signal oursig;
8686 sig_print_header ();
8690 /* First see if this is a symbol name. */
8691 oursig = gdb_signal_from_name (signum_exp);
8692 if (oursig == GDB_SIGNAL_UNKNOWN)
8694 /* No, try numeric. */
8696 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8698 sig_print_info (oursig);
8702 printf_filtered ("\n");
8703 /* These ugly casts brought to you by the native VAX compiler. */
8704 for (oursig = GDB_SIGNAL_FIRST;
8705 (int) oursig < (int) GDB_SIGNAL_LAST;
8706 oursig = (enum gdb_signal) ((int) oursig + 1))
8710 if (oursig != GDB_SIGNAL_UNKNOWN
8711 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8712 sig_print_info (oursig);
8715 printf_filtered (_("\nUse the \"handle\" command "
8716 "to change these tables.\n"));
8719 /* The $_siginfo convenience variable is a bit special. We don't know
8720 for sure the type of the value until we actually have a chance to
8721 fetch the data. The type can change depending on gdbarch, so it is
8722 also dependent on which thread you have selected.
8724 1. making $_siginfo be an internalvar that creates a new value on
8727 2. making the value of $_siginfo be an lval_computed value. */
8729 /* This function implements the lval_computed support for reading a
8733 siginfo_value_read (struct value *v)
8735 LONGEST transferred;
8737 /* If we can access registers, so can we access $_siginfo. Likewise
8739 validate_registers_access ();
8742 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8744 value_contents_all_raw (v),
8746 TYPE_LENGTH (value_type (v)));
8748 if (transferred != TYPE_LENGTH (value_type (v)))
8749 error (_("Unable to read siginfo"));
8752 /* This function implements the lval_computed support for writing a
8756 siginfo_value_write (struct value *v, struct value *fromval)
8758 LONGEST transferred;
8760 /* If we can access registers, so can we access $_siginfo. Likewise
8762 validate_registers_access ();
8764 transferred = target_write (¤t_target,
8765 TARGET_OBJECT_SIGNAL_INFO,
8767 value_contents_all_raw (fromval),
8769 TYPE_LENGTH (value_type (fromval)));
8771 if (transferred != TYPE_LENGTH (value_type (fromval)))
8772 error (_("Unable to write siginfo"));
8775 static const struct lval_funcs siginfo_value_funcs =
8781 /* Return a new value with the correct type for the siginfo object of
8782 the current thread using architecture GDBARCH. Return a void value
8783 if there's no object available. */
8785 static struct value *
8786 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8789 if (target_has_stack
8790 && !ptid_equal (inferior_ptid, null_ptid)
8791 && gdbarch_get_siginfo_type_p (gdbarch))
8793 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8795 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8798 return allocate_value (builtin_type (gdbarch)->builtin_void);
8802 /* infcall_suspend_state contains state about the program itself like its
8803 registers and any signal it received when it last stopped.
8804 This state must be restored regardless of how the inferior function call
8805 ends (either successfully, or after it hits a breakpoint or signal)
8806 if the program is to properly continue where it left off. */
8808 struct infcall_suspend_state
8810 struct thread_suspend_state thread_suspend;
8814 struct regcache *registers;
8816 /* Format of SIGINFO_DATA or NULL if it is not present. */
8817 struct gdbarch *siginfo_gdbarch;
8819 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8820 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8821 content would be invalid. */
8822 gdb_byte *siginfo_data;
8825 struct infcall_suspend_state *
8826 save_infcall_suspend_state (void)
8828 struct infcall_suspend_state *inf_state;
8829 struct thread_info *tp = inferior_thread ();
8830 struct regcache *regcache = get_current_regcache ();
8831 struct gdbarch *gdbarch = regcache->arch ();
8832 gdb_byte *siginfo_data = NULL;
8834 if (gdbarch_get_siginfo_type_p (gdbarch))
8836 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8837 size_t len = TYPE_LENGTH (type);
8838 struct cleanup *back_to;
8840 siginfo_data = (gdb_byte *) xmalloc (len);
8841 back_to = make_cleanup (xfree, siginfo_data);
8843 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8844 siginfo_data, 0, len) == len)
8845 discard_cleanups (back_to);
8848 /* Errors ignored. */
8849 do_cleanups (back_to);
8850 siginfo_data = NULL;
8854 inf_state = XCNEW (struct infcall_suspend_state);
8858 inf_state->siginfo_gdbarch = gdbarch;
8859 inf_state->siginfo_data = siginfo_data;
8862 inf_state->thread_suspend = tp->suspend;
8864 /* run_inferior_call will not use the signal due to its `proceed' call with
8865 GDB_SIGNAL_0 anyway. */
8866 tp->suspend.stop_signal = GDB_SIGNAL_0;
8868 inf_state->stop_pc = stop_pc;
8870 inf_state->registers = regcache_dup (regcache);
8875 /* Restore inferior session state to INF_STATE. */
8878 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8880 struct thread_info *tp = inferior_thread ();
8881 struct regcache *regcache = get_current_regcache ();
8882 struct gdbarch *gdbarch = regcache->arch ();
8884 tp->suspend = inf_state->thread_suspend;
8886 stop_pc = inf_state->stop_pc;
8888 if (inf_state->siginfo_gdbarch == gdbarch)
8890 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8892 /* Errors ignored. */
8893 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8894 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8897 /* The inferior can be gone if the user types "print exit(0)"
8898 (and perhaps other times). */
8899 if (target_has_execution)
8900 /* NB: The register write goes through to the target. */
8901 regcache_cpy (regcache, inf_state->registers);
8903 discard_infcall_suspend_state (inf_state);
8907 do_restore_infcall_suspend_state_cleanup (void *state)
8909 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8913 make_cleanup_restore_infcall_suspend_state
8914 (struct infcall_suspend_state *inf_state)
8916 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8920 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8922 delete inf_state->registers;
8923 xfree (inf_state->siginfo_data);
8928 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8930 return inf_state->registers;
8933 /* infcall_control_state contains state regarding gdb's control of the
8934 inferior itself like stepping control. It also contains session state like
8935 the user's currently selected frame. */
8937 struct infcall_control_state
8939 struct thread_control_state thread_control;
8940 struct inferior_control_state inferior_control;
8943 enum stop_stack_kind stop_stack_dummy;
8944 int stopped_by_random_signal;
8946 /* ID if the selected frame when the inferior function call was made. */
8947 struct frame_id selected_frame_id;
8950 /* Save all of the information associated with the inferior<==>gdb
8953 struct infcall_control_state *
8954 save_infcall_control_state (void)
8956 struct infcall_control_state *inf_status =
8957 XNEW (struct infcall_control_state);
8958 struct thread_info *tp = inferior_thread ();
8959 struct inferior *inf = current_inferior ();
8961 inf_status->thread_control = tp->control;
8962 inf_status->inferior_control = inf->control;
8964 tp->control.step_resume_breakpoint = NULL;
8965 tp->control.exception_resume_breakpoint = NULL;
8967 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8968 chain. If caller's caller is walking the chain, they'll be happier if we
8969 hand them back the original chain when restore_infcall_control_state is
8971 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8974 inf_status->stop_stack_dummy = stop_stack_dummy;
8975 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8977 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8983 restore_selected_frame (const frame_id &fid)
8985 frame_info *frame = frame_find_by_id (fid);
8987 /* If inf_status->selected_frame_id is NULL, there was no previously
8991 warning (_("Unable to restore previously selected frame."));
8995 select_frame (frame);
8998 /* Restore inferior session state to INF_STATUS. */
9001 restore_infcall_control_state (struct infcall_control_state *inf_status)
9003 struct thread_info *tp = inferior_thread ();
9004 struct inferior *inf = current_inferior ();
9006 if (tp->control.step_resume_breakpoint)
9007 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
9009 if (tp->control.exception_resume_breakpoint)
9010 tp->control.exception_resume_breakpoint->disposition
9011 = disp_del_at_next_stop;
9013 /* Handle the bpstat_copy of the chain. */
9014 bpstat_clear (&tp->control.stop_bpstat);
9016 tp->control = inf_status->thread_control;
9017 inf->control = inf_status->inferior_control;
9020 stop_stack_dummy = inf_status->stop_stack_dummy;
9021 stopped_by_random_signal = inf_status->stopped_by_random_signal;
9023 if (target_has_stack)
9025 /* The point of the try/catch is that if the stack is clobbered,
9026 walking the stack might encounter a garbage pointer and
9027 error() trying to dereference it. */
9030 restore_selected_frame (inf_status->selected_frame_id);
9032 CATCH (ex, RETURN_MASK_ERROR)
9034 exception_fprintf (gdb_stderr, ex,
9035 "Unable to restore previously selected frame:\n");
9036 /* Error in restoring the selected frame. Select the
9038 select_frame (get_current_frame ());
9047 do_restore_infcall_control_state_cleanup (void *sts)
9049 restore_infcall_control_state ((struct infcall_control_state *) sts);
9053 make_cleanup_restore_infcall_control_state
9054 (struct infcall_control_state *inf_status)
9056 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9060 discard_infcall_control_state (struct infcall_control_state *inf_status)
9062 if (inf_status->thread_control.step_resume_breakpoint)
9063 inf_status->thread_control.step_resume_breakpoint->disposition
9064 = disp_del_at_next_stop;
9066 if (inf_status->thread_control.exception_resume_breakpoint)
9067 inf_status->thread_control.exception_resume_breakpoint->disposition
9068 = disp_del_at_next_stop;
9070 /* See save_infcall_control_state for info on stop_bpstat. */
9071 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9079 clear_exit_convenience_vars (void)
9081 clear_internalvar (lookup_internalvar ("_exitsignal"));
9082 clear_internalvar (lookup_internalvar ("_exitcode"));
9086 /* User interface for reverse debugging:
9087 Set exec-direction / show exec-direction commands
9088 (returns error unless target implements to_set_exec_direction method). */
9090 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9091 static const char exec_forward[] = "forward";
9092 static const char exec_reverse[] = "reverse";
9093 static const char *exec_direction = exec_forward;
9094 static const char *const exec_direction_names[] = {
9101 set_exec_direction_func (char *args, int from_tty,
9102 struct cmd_list_element *cmd)
9104 if (target_can_execute_reverse)
9106 if (!strcmp (exec_direction, exec_forward))
9107 execution_direction = EXEC_FORWARD;
9108 else if (!strcmp (exec_direction, exec_reverse))
9109 execution_direction = EXEC_REVERSE;
9113 exec_direction = exec_forward;
9114 error (_("Target does not support this operation."));
9119 show_exec_direction_func (struct ui_file *out, int from_tty,
9120 struct cmd_list_element *cmd, const char *value)
9122 switch (execution_direction) {
9124 fprintf_filtered (out, _("Forward.\n"));
9127 fprintf_filtered (out, _("Reverse.\n"));
9130 internal_error (__FILE__, __LINE__,
9131 _("bogus execution_direction value: %d"),
9132 (int) execution_direction);
9137 show_schedule_multiple (struct ui_file *file, int from_tty,
9138 struct cmd_list_element *c, const char *value)
9140 fprintf_filtered (file, _("Resuming the execution of threads "
9141 "of all processes is %s.\n"), value);
9144 /* Implementation of `siginfo' variable. */
9146 static const struct internalvar_funcs siginfo_funcs =
9153 /* Callback for infrun's target events source. This is marked when a
9154 thread has a pending status to process. */
9157 infrun_async_inferior_event_handler (gdb_client_data data)
9159 inferior_event_handler (INF_REG_EVENT, NULL);
9163 _initialize_infrun (void)
9167 struct cmd_list_element *c;
9169 /* Register extra event sources in the event loop. */
9170 infrun_async_inferior_event_token
9171 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9173 add_info ("signals", info_signals_command, _("\
9174 What debugger does when program gets various signals.\n\
9175 Specify a signal as argument to print info on that signal only."));
9176 add_info_alias ("handle", "signals", 0);
9178 c = add_com ("handle", class_run, handle_command, _("\
9179 Specify how to handle signals.\n\
9180 Usage: handle SIGNAL [ACTIONS]\n\
9181 Args are signals and actions to apply to those signals.\n\
9182 If no actions are specified, the current settings for the specified signals\n\
9183 will be displayed instead.\n\
9185 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9186 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9187 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9188 The special arg \"all\" is recognized to mean all signals except those\n\
9189 used by the debugger, typically SIGTRAP and SIGINT.\n\
9191 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9192 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9193 Stop means reenter debugger if this signal happens (implies print).\n\
9194 Print means print a message if this signal happens.\n\
9195 Pass means let program see this signal; otherwise program doesn't know.\n\
9196 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9197 Pass and Stop may be combined.\n\
9199 Multiple signals may be specified. Signal numbers and signal names\n\
9200 may be interspersed with actions, with the actions being performed for\n\
9201 all signals cumulatively specified."));
9202 set_cmd_completer (c, handle_completer);
9205 stop_command = add_cmd ("stop", class_obscure,
9206 not_just_help_class_command, _("\
9207 There is no `stop' command, but you can set a hook on `stop'.\n\
9208 This allows you to set a list of commands to be run each time execution\n\
9209 of the program stops."), &cmdlist);
9211 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9212 Set inferior debugging."), _("\
9213 Show inferior debugging."), _("\
9214 When non-zero, inferior specific debugging is enabled."),
9217 &setdebuglist, &showdebuglist);
9219 add_setshow_boolean_cmd ("displaced", class_maintenance,
9220 &debug_displaced, _("\
9221 Set displaced stepping debugging."), _("\
9222 Show displaced stepping debugging."), _("\
9223 When non-zero, displaced stepping specific debugging is enabled."),
9225 show_debug_displaced,
9226 &setdebuglist, &showdebuglist);
9228 add_setshow_boolean_cmd ("non-stop", no_class,
9230 Set whether gdb controls the inferior in non-stop mode."), _("\
9231 Show whether gdb controls the inferior in non-stop mode."), _("\
9232 When debugging a multi-threaded program and this setting is\n\
9233 off (the default, also called all-stop mode), when one thread stops\n\
9234 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9235 all other threads in the program while you interact with the thread of\n\
9236 interest. When you continue or step a thread, you can allow the other\n\
9237 threads to run, or have them remain stopped, but while you inspect any\n\
9238 thread's state, all threads stop.\n\
9240 In non-stop mode, when one thread stops, other threads can continue\n\
9241 to run freely. You'll be able to step each thread independently,\n\
9242 leave it stopped or free to run as needed."),
9248 numsigs = (int) GDB_SIGNAL_LAST;
9249 signal_stop = XNEWVEC (unsigned char, numsigs);
9250 signal_print = XNEWVEC (unsigned char, numsigs);
9251 signal_program = XNEWVEC (unsigned char, numsigs);
9252 signal_catch = XNEWVEC (unsigned char, numsigs);
9253 signal_pass = XNEWVEC (unsigned char, numsigs);
9254 for (i = 0; i < numsigs; i++)
9257 signal_print[i] = 1;
9258 signal_program[i] = 1;
9259 signal_catch[i] = 0;
9262 /* Signals caused by debugger's own actions should not be given to
9263 the program afterwards.
9265 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9266 explicitly specifies that it should be delivered to the target
9267 program. Typically, that would occur when a user is debugging a
9268 target monitor on a simulator: the target monitor sets a
9269 breakpoint; the simulator encounters this breakpoint and halts
9270 the simulation handing control to GDB; GDB, noting that the stop
9271 address doesn't map to any known breakpoint, returns control back
9272 to the simulator; the simulator then delivers the hardware
9273 equivalent of a GDB_SIGNAL_TRAP to the program being
9275 signal_program[GDB_SIGNAL_TRAP] = 0;
9276 signal_program[GDB_SIGNAL_INT] = 0;
9278 /* Signals that are not errors should not normally enter the debugger. */
9279 signal_stop[GDB_SIGNAL_ALRM] = 0;
9280 signal_print[GDB_SIGNAL_ALRM] = 0;
9281 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9282 signal_print[GDB_SIGNAL_VTALRM] = 0;
9283 signal_stop[GDB_SIGNAL_PROF] = 0;
9284 signal_print[GDB_SIGNAL_PROF] = 0;
9285 signal_stop[GDB_SIGNAL_CHLD] = 0;
9286 signal_print[GDB_SIGNAL_CHLD] = 0;
9287 signal_stop[GDB_SIGNAL_IO] = 0;
9288 signal_print[GDB_SIGNAL_IO] = 0;
9289 signal_stop[GDB_SIGNAL_POLL] = 0;
9290 signal_print[GDB_SIGNAL_POLL] = 0;
9291 signal_stop[GDB_SIGNAL_URG] = 0;
9292 signal_print[GDB_SIGNAL_URG] = 0;
9293 signal_stop[GDB_SIGNAL_WINCH] = 0;
9294 signal_print[GDB_SIGNAL_WINCH] = 0;
9295 signal_stop[GDB_SIGNAL_PRIO] = 0;
9296 signal_print[GDB_SIGNAL_PRIO] = 0;
9298 /* These signals are used internally by user-level thread
9299 implementations. (See signal(5) on Solaris.) Like the above
9300 signals, a healthy program receives and handles them as part of
9301 its normal operation. */
9302 signal_stop[GDB_SIGNAL_LWP] = 0;
9303 signal_print[GDB_SIGNAL_LWP] = 0;
9304 signal_stop[GDB_SIGNAL_WAITING] = 0;
9305 signal_print[GDB_SIGNAL_WAITING] = 0;
9306 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9307 signal_print[GDB_SIGNAL_CANCEL] = 0;
9308 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9309 signal_print[GDB_SIGNAL_LIBRT] = 0;
9311 /* Update cached state. */
9312 signal_cache_update (-1);
9314 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9315 &stop_on_solib_events, _("\
9316 Set stopping for shared library events."), _("\
9317 Show stopping for shared library events."), _("\
9318 If nonzero, gdb will give control to the user when the dynamic linker\n\
9319 notifies gdb of shared library events. The most common event of interest\n\
9320 to the user would be loading/unloading of a new library."),
9321 set_stop_on_solib_events,
9322 show_stop_on_solib_events,
9323 &setlist, &showlist);
9325 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9326 follow_fork_mode_kind_names,
9327 &follow_fork_mode_string, _("\
9328 Set debugger response to a program call of fork or vfork."), _("\
9329 Show debugger response to a program call of fork or vfork."), _("\
9330 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9331 parent - the original process is debugged after a fork\n\
9332 child - the new process is debugged after a fork\n\
9333 The unfollowed process will continue to run.\n\
9334 By default, the debugger will follow the parent process."),
9336 show_follow_fork_mode_string,
9337 &setlist, &showlist);
9339 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9340 follow_exec_mode_names,
9341 &follow_exec_mode_string, _("\
9342 Set debugger response to a program call of exec."), _("\
9343 Show debugger response to a program call of exec."), _("\
9344 An exec call replaces the program image of a process.\n\
9346 follow-exec-mode can be:\n\
9348 new - the debugger creates a new inferior and rebinds the process\n\
9349 to this new inferior. The program the process was running before\n\
9350 the exec call can be restarted afterwards by restarting the original\n\
9353 same - the debugger keeps the process bound to the same inferior.\n\
9354 The new executable image replaces the previous executable loaded in\n\
9355 the inferior. Restarting the inferior after the exec call restarts\n\
9356 the executable the process was running after the exec call.\n\
9358 By default, the debugger will use the same inferior."),
9360 show_follow_exec_mode_string,
9361 &setlist, &showlist);
9363 add_setshow_enum_cmd ("scheduler-locking", class_run,
9364 scheduler_enums, &scheduler_mode, _("\
9365 Set mode for locking scheduler during execution."), _("\
9366 Show mode for locking scheduler during execution."), _("\
9367 off == no locking (threads may preempt at any time)\n\
9368 on == full locking (no thread except the current thread may run)\n\
9369 This applies to both normal execution and replay mode.\n\
9370 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9371 In this mode, other threads may run during other commands.\n\
9372 This applies to both normal execution and replay mode.\n\
9373 replay == scheduler locked in replay mode and unlocked during normal execution."),
9374 set_schedlock_func, /* traps on target vector */
9375 show_scheduler_mode,
9376 &setlist, &showlist);
9378 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9379 Set mode for resuming threads of all processes."), _("\
9380 Show mode for resuming threads of all processes."), _("\
9381 When on, execution commands (such as 'continue' or 'next') resume all\n\
9382 threads of all processes. When off (which is the default), execution\n\
9383 commands only resume the threads of the current process. The set of\n\
9384 threads that are resumed is further refined by the scheduler-locking\n\
9385 mode (see help set scheduler-locking)."),
9387 show_schedule_multiple,
9388 &setlist, &showlist);
9390 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9391 Set mode of the step operation."), _("\
9392 Show mode of the step operation."), _("\
9393 When set, doing a step over a function without debug line information\n\
9394 will stop at the first instruction of that function. Otherwise, the\n\
9395 function is skipped and the step command stops at a different source line."),
9397 show_step_stop_if_no_debug,
9398 &setlist, &showlist);
9400 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9401 &can_use_displaced_stepping, _("\
9402 Set debugger's willingness to use displaced stepping."), _("\
9403 Show debugger's willingness to use displaced stepping."), _("\
9404 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9405 supported by the target architecture. If off, gdb will not use displaced\n\
9406 stepping to step over breakpoints, even if such is supported by the target\n\
9407 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9408 if the target architecture supports it and non-stop mode is active, but will not\n\
9409 use it in all-stop mode (see help set non-stop)."),
9411 show_can_use_displaced_stepping,
9412 &setlist, &showlist);
9414 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9415 &exec_direction, _("Set direction of execution.\n\
9416 Options are 'forward' or 'reverse'."),
9417 _("Show direction of execution (forward/reverse)."),
9418 _("Tells gdb whether to execute forward or backward."),
9419 set_exec_direction_func, show_exec_direction_func,
9420 &setlist, &showlist);
9422 /* Set/show detach-on-fork: user-settable mode. */
9424 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9425 Set whether gdb will detach the child of a fork."), _("\
9426 Show whether gdb will detach the child of a fork."), _("\
9427 Tells gdb whether to detach the child of a fork."),
9428 NULL, NULL, &setlist, &showlist);
9430 /* Set/show disable address space randomization mode. */
9432 add_setshow_boolean_cmd ("disable-randomization", class_support,
9433 &disable_randomization, _("\
9434 Set disabling of debuggee's virtual address space randomization."), _("\
9435 Show disabling of debuggee's virtual address space randomization."), _("\
9436 When this mode is on (which is the default), randomization of the virtual\n\
9437 address space is disabled. Standalone programs run with the randomization\n\
9438 enabled by default on some platforms."),
9439 &set_disable_randomization,
9440 &show_disable_randomization,
9441 &setlist, &showlist);
9443 /* ptid initializations */
9444 inferior_ptid = null_ptid;
9445 target_last_wait_ptid = minus_one_ptid;
9447 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9448 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9449 observer_attach_thread_exit (infrun_thread_thread_exit);
9450 observer_attach_inferior_exit (infrun_inferior_exit);
9452 /* Explicitly create without lookup, since that tries to create a
9453 value with a void typed value, and when we get here, gdbarch
9454 isn't initialized yet. At this point, we're quite sure there
9455 isn't another convenience variable of the same name. */
9456 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9458 add_setshow_boolean_cmd ("observer", no_class,
9459 &observer_mode_1, _("\
9460 Set whether gdb controls the inferior in observer mode."), _("\
9461 Show whether gdb controls the inferior in observer mode."), _("\
9462 In observer mode, GDB can get data from the inferior, but not\n\
9463 affect its execution. Registers and memory may not be changed,\n\
9464 breakpoints may not be set, and the program cannot be interrupted\n\