1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2014 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 /* Prototypes for local functions */
66 static void signals_info (char *, int);
68 static void handle_command (char *, int);
70 static void sig_print_info (enum gdb_signal);
72 static void sig_print_header (void);
74 static void resume_cleanups (void *);
76 static int hook_stop_stub (void *);
78 static int restore_selected_frame (void *);
80 static int follow_fork (void);
82 static int follow_fork_inferior (int follow_child, int detach_fork);
84 static void follow_inferior_reset_breakpoints (void);
86 static void set_schedlock_func (char *args, int from_tty,
87 struct cmd_list_element *c);
89 static int currently_stepping (struct thread_info *tp);
91 static void xdb_handle_command (char *args, int from_tty);
93 void _initialize_infrun (void);
95 void nullify_last_target_wait_ptid (void);
97 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
99 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
101 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
103 /* When set, stop the 'step' command if we enter a function which has
104 no line number information. The normal behavior is that we step
105 over such function. */
106 int step_stop_if_no_debug = 0;
108 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
109 struct cmd_list_element *c, const char *value)
111 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
114 /* In asynchronous mode, but simulating synchronous execution. */
116 int sync_execution = 0;
118 /* proceed and normal_stop use this to notify the user when the
119 inferior stopped in a different thread than it had been running
122 static ptid_t previous_inferior_ptid;
124 /* If set (default for legacy reasons), when following a fork, GDB
125 will detach from one of the fork branches, child or parent.
126 Exactly which branch is detached depends on 'set follow-fork-mode'
129 static int detach_fork = 1;
131 int debug_displaced = 0;
133 show_debug_displaced (struct ui_file *file, int from_tty,
134 struct cmd_list_element *c, const char *value)
136 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
139 unsigned int debug_infrun = 0;
141 show_debug_infrun (struct ui_file *file, int from_tty,
142 struct cmd_list_element *c, const char *value)
144 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
148 /* Support for disabling address space randomization. */
150 int disable_randomization = 1;
153 show_disable_randomization (struct ui_file *file, int from_tty,
154 struct cmd_list_element *c, const char *value)
156 if (target_supports_disable_randomization ())
157 fprintf_filtered (file,
158 _("Disabling randomization of debuggee's "
159 "virtual address space is %s.\n"),
162 fputs_filtered (_("Disabling randomization of debuggee's "
163 "virtual address space is unsupported on\n"
164 "this platform.\n"), file);
168 set_disable_randomization (char *args, int from_tty,
169 struct cmd_list_element *c)
171 if (!target_supports_disable_randomization ())
172 error (_("Disabling randomization of debuggee's "
173 "virtual address space is unsupported on\n"
177 /* User interface for non-stop mode. */
180 static int non_stop_1 = 0;
183 set_non_stop (char *args, int from_tty,
184 struct cmd_list_element *c)
186 if (target_has_execution)
188 non_stop_1 = non_stop;
189 error (_("Cannot change this setting while the inferior is running."));
192 non_stop = non_stop_1;
196 show_non_stop (struct ui_file *file, int from_tty,
197 struct cmd_list_element *c, const char *value)
199 fprintf_filtered (file,
200 _("Controlling the inferior in non-stop mode is %s.\n"),
204 /* "Observer mode" is somewhat like a more extreme version of
205 non-stop, in which all GDB operations that might affect the
206 target's execution have been disabled. */
208 int observer_mode = 0;
209 static int observer_mode_1 = 0;
212 set_observer_mode (char *args, int from_tty,
213 struct cmd_list_element *c)
215 if (target_has_execution)
217 observer_mode_1 = observer_mode;
218 error (_("Cannot change this setting while the inferior is running."));
221 observer_mode = observer_mode_1;
223 may_write_registers = !observer_mode;
224 may_write_memory = !observer_mode;
225 may_insert_breakpoints = !observer_mode;
226 may_insert_tracepoints = !observer_mode;
227 /* We can insert fast tracepoints in or out of observer mode,
228 but enable them if we're going into this mode. */
230 may_insert_fast_tracepoints = 1;
231 may_stop = !observer_mode;
232 update_target_permissions ();
234 /* Going *into* observer mode we must force non-stop, then
235 going out we leave it that way. */
238 pagination_enabled = 0;
239 non_stop = non_stop_1 = 1;
243 printf_filtered (_("Observer mode is now %s.\n"),
244 (observer_mode ? "on" : "off"));
248 show_observer_mode (struct ui_file *file, int from_tty,
249 struct cmd_list_element *c, const char *value)
251 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
254 /* This updates the value of observer mode based on changes in
255 permissions. Note that we are deliberately ignoring the values of
256 may-write-registers and may-write-memory, since the user may have
257 reason to enable these during a session, for instance to turn on a
258 debugging-related global. */
261 update_observer_mode (void)
265 newval = (!may_insert_breakpoints
266 && !may_insert_tracepoints
267 && may_insert_fast_tracepoints
271 /* Let the user know if things change. */
272 if (newval != observer_mode)
273 printf_filtered (_("Observer mode is now %s.\n"),
274 (newval ? "on" : "off"));
276 observer_mode = observer_mode_1 = newval;
279 /* Tables of how to react to signals; the user sets them. */
281 static unsigned char *signal_stop;
282 static unsigned char *signal_print;
283 static unsigned char *signal_program;
285 /* Table of signals that are registered with "catch signal". A
286 non-zero entry indicates that the signal is caught by some "catch
287 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
289 static unsigned char *signal_catch;
291 /* Table of signals that the target may silently handle.
292 This is automatically determined from the flags above,
293 and simply cached here. */
294 static unsigned char *signal_pass;
296 #define SET_SIGS(nsigs,sigs,flags) \
298 int signum = (nsigs); \
299 while (signum-- > 0) \
300 if ((sigs)[signum]) \
301 (flags)[signum] = 1; \
304 #define UNSET_SIGS(nsigs,sigs,flags) \
306 int signum = (nsigs); \
307 while (signum-- > 0) \
308 if ((sigs)[signum]) \
309 (flags)[signum] = 0; \
312 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
313 this function is to avoid exporting `signal_program'. */
316 update_signals_program_target (void)
318 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
321 /* Value to pass to target_resume() to cause all threads to resume. */
323 #define RESUME_ALL minus_one_ptid
325 /* Command list pointer for the "stop" placeholder. */
327 static struct cmd_list_element *stop_command;
329 /* Function inferior was in as of last step command. */
331 static struct symbol *step_start_function;
333 /* Nonzero if we want to give control to the user when we're notified
334 of shared library events by the dynamic linker. */
335 int stop_on_solib_events;
337 /* Enable or disable optional shared library event breakpoints
338 as appropriate when the above flag is changed. */
341 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
343 update_solib_breakpoints ();
347 show_stop_on_solib_events (struct ui_file *file, int from_tty,
348 struct cmd_list_element *c, const char *value)
350 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
354 /* Nonzero means expecting a trace trap
355 and should stop the inferior and return silently when it happens. */
359 /* Save register contents here when executing a "finish" command or are
360 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
361 Thus this contains the return value from the called function (assuming
362 values are returned in a register). */
364 struct regcache *stop_registers;
366 /* Nonzero after stop if current stack frame should be printed. */
368 static int stop_print_frame;
370 /* This is a cached copy of the pid/waitstatus of the last event
371 returned by target_wait()/deprecated_target_wait_hook(). This
372 information is returned by get_last_target_status(). */
373 static ptid_t target_last_wait_ptid;
374 static struct target_waitstatus target_last_waitstatus;
376 static void context_switch (ptid_t ptid);
378 void init_thread_stepping_state (struct thread_info *tss);
380 static const char follow_fork_mode_child[] = "child";
381 static const char follow_fork_mode_parent[] = "parent";
383 static const char *const follow_fork_mode_kind_names[] = {
384 follow_fork_mode_child,
385 follow_fork_mode_parent,
389 static const char *follow_fork_mode_string = follow_fork_mode_parent;
391 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
392 struct cmd_list_element *c, const char *value)
394 fprintf_filtered (file,
395 _("Debugger response to a program "
396 "call of fork or vfork is \"%s\".\n"),
401 /* Handle changes to the inferior list based on the type of fork,
402 which process is being followed, and whether the other process
403 should be detached. On entry inferior_ptid must be the ptid of
404 the fork parent. At return inferior_ptid is the ptid of the
405 followed inferior. */
408 follow_fork_inferior (int follow_child, int detach_fork)
411 int parent_pid, child_pid;
413 has_vforked = (inferior_thread ()->pending_follow.kind
414 == TARGET_WAITKIND_VFORKED);
415 parent_pid = ptid_get_lwp (inferior_ptid);
417 parent_pid = ptid_get_pid (inferior_ptid);
419 = ptid_get_pid (inferior_thread ()->pending_follow.value.related_pid);
422 && !non_stop /* Non-stop always resumes both branches. */
423 && (!target_is_async_p () || sync_execution)
424 && !(follow_child || detach_fork || sched_multi))
426 /* The parent stays blocked inside the vfork syscall until the
427 child execs or exits. If we don't let the child run, then
428 the parent stays blocked. If we're telling the parent to run
429 in the foreground, the user will not be able to ctrl-c to get
430 back the terminal, effectively hanging the debug session. */
431 fprintf_filtered (gdb_stderr, _("\
432 Can not resume the parent process over vfork in the foreground while\n\
433 holding the child stopped. Try \"set detach-on-fork\" or \
434 \"set schedule-multiple\".\n"));
435 /* FIXME output string > 80 columns. */
441 /* Detach new forked process? */
444 struct cleanup *old_chain;
446 /* Before detaching from the child, remove all breakpoints
447 from it. If we forked, then this has already been taken
448 care of by infrun.c. If we vforked however, any
449 breakpoint inserted in the parent is visible in the
450 child, even those added while stopped in a vfork
451 catchpoint. This will remove the breakpoints from the
452 parent also, but they'll be reinserted below. */
455 /* Keep breakpoints list in sync. */
456 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
459 if (info_verbose || debug_infrun)
461 target_terminal_ours_for_output ();
462 fprintf_filtered (gdb_stdlog,
463 _("Detaching after %s from "
464 "child process %d.\n"),
465 has_vforked ? "vfork" : "fork",
471 struct inferior *parent_inf, *child_inf;
472 struct cleanup *old_chain;
474 /* Add process to GDB's tables. */
475 child_inf = add_inferior (child_pid);
477 parent_inf = current_inferior ();
478 child_inf->attach_flag = parent_inf->attach_flag;
479 copy_terminal_info (child_inf, parent_inf);
480 child_inf->gdbarch = parent_inf->gdbarch;
481 copy_inferior_target_desc_info (child_inf, parent_inf);
483 old_chain = save_inferior_ptid ();
484 save_current_program_space ();
486 inferior_ptid = ptid_build (child_pid, child_pid, 0);
487 add_thread (inferior_ptid);
488 child_inf->symfile_flags = SYMFILE_NO_READ;
490 /* If this is a vfork child, then the address-space is
491 shared with the parent. */
494 child_inf->pspace = parent_inf->pspace;
495 child_inf->aspace = parent_inf->aspace;
497 /* The parent will be frozen until the child is done
498 with the shared region. Keep track of the
500 child_inf->vfork_parent = parent_inf;
501 child_inf->pending_detach = 0;
502 parent_inf->vfork_child = child_inf;
503 parent_inf->pending_detach = 0;
507 child_inf->aspace = new_address_space ();
508 child_inf->pspace = add_program_space (child_inf->aspace);
509 child_inf->removable = 1;
510 set_current_program_space (child_inf->pspace);
511 clone_program_space (child_inf->pspace, parent_inf->pspace);
513 /* Let the shared library layer (e.g., solib-svr4) learn
514 about this new process, relocate the cloned exec, pull
515 in shared libraries, and install the solib event
516 breakpoint. If a "cloned-VM" event was propagated
517 better throughout the core, this wouldn't be
519 solib_create_inferior_hook (0);
522 do_cleanups (old_chain);
527 struct inferior *parent_inf;
529 parent_inf = current_inferior ();
531 /* If we detached from the child, then we have to be careful
532 to not insert breakpoints in the parent until the child
533 is done with the shared memory region. However, if we're
534 staying attached to the child, then we can and should
535 insert breakpoints, so that we can debug it. A
536 subsequent child exec or exit is enough to know when does
537 the child stops using the parent's address space. */
538 parent_inf->waiting_for_vfork_done = detach_fork;
539 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
544 /* Follow the child. */
545 struct inferior *parent_inf, *child_inf;
546 struct program_space *parent_pspace;
548 if (info_verbose || debug_infrun)
550 target_terminal_ours_for_output ();
551 fprintf_filtered (gdb_stdlog,
552 _("Attaching after process %d "
553 "%s to child process %d.\n"),
555 has_vforked ? "vfork" : "fork",
559 /* Add the new inferior first, so that the target_detach below
560 doesn't unpush the target. */
562 child_inf = add_inferior (child_pid);
564 parent_inf = current_inferior ();
565 child_inf->attach_flag = parent_inf->attach_flag;
566 copy_terminal_info (child_inf, parent_inf);
567 child_inf->gdbarch = parent_inf->gdbarch;
568 copy_inferior_target_desc_info (child_inf, parent_inf);
570 parent_pspace = parent_inf->pspace;
572 /* If we're vforking, we want to hold on to the parent until the
573 child exits or execs. At child exec or exit time we can
574 remove the old breakpoints from the parent and detach or
575 resume debugging it. Otherwise, detach the parent now; we'll
576 want to reuse it's program/address spaces, but we can't set
577 them to the child before removing breakpoints from the
578 parent, otherwise, the breakpoints module could decide to
579 remove breakpoints from the wrong process (since they'd be
580 assigned to the same address space). */
584 gdb_assert (child_inf->vfork_parent == NULL);
585 gdb_assert (parent_inf->vfork_child == NULL);
586 child_inf->vfork_parent = parent_inf;
587 child_inf->pending_detach = 0;
588 parent_inf->vfork_child = child_inf;
589 parent_inf->pending_detach = detach_fork;
590 parent_inf->waiting_for_vfork_done = 0;
592 else if (detach_fork)
594 if (info_verbose || debug_infrun)
596 target_terminal_ours_for_output ();
597 fprintf_filtered (gdb_stdlog,
598 _("Detaching after fork from "
599 "child process %d.\n"),
603 target_detach (NULL, 0);
606 /* Note that the detach above makes PARENT_INF dangling. */
608 /* Add the child thread to the appropriate lists, and switch to
609 this new thread, before cloning the program space, and
610 informing the solib layer about this new process. */
612 inferior_ptid = ptid_build (child_pid, child_pid, 0);
613 add_thread (inferior_ptid);
615 /* If this is a vfork child, then the address-space is shared
616 with the parent. If we detached from the parent, then we can
617 reuse the parent's program/address spaces. */
618 if (has_vforked || detach_fork)
620 child_inf->pspace = parent_pspace;
621 child_inf->aspace = child_inf->pspace->aspace;
625 child_inf->aspace = new_address_space ();
626 child_inf->pspace = add_program_space (child_inf->aspace);
627 child_inf->removable = 1;
628 child_inf->symfile_flags = SYMFILE_NO_READ;
629 set_current_program_space (child_inf->pspace);
630 clone_program_space (child_inf->pspace, parent_pspace);
632 /* Let the shared library layer (e.g., solib-svr4) learn
633 about this new process, relocate the cloned exec, pull in
634 shared libraries, and install the solib event breakpoint.
635 If a "cloned-VM" event was propagated better throughout
636 the core, this wouldn't be required. */
637 solib_create_inferior_hook (0);
641 return target_follow_fork (follow_child, detach_fork);
644 /* Tell the target to follow the fork we're stopped at. Returns true
645 if the inferior should be resumed; false, if the target for some
646 reason decided it's best not to resume. */
651 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
652 int should_resume = 1;
653 struct thread_info *tp;
655 /* Copy user stepping state to the new inferior thread. FIXME: the
656 followed fork child thread should have a copy of most of the
657 parent thread structure's run control related fields, not just these.
658 Initialized to avoid "may be used uninitialized" warnings from gcc. */
659 struct breakpoint *step_resume_breakpoint = NULL;
660 struct breakpoint *exception_resume_breakpoint = NULL;
661 CORE_ADDR step_range_start = 0;
662 CORE_ADDR step_range_end = 0;
663 struct frame_id step_frame_id = { 0 };
664 struct interp *command_interp = NULL;
669 struct target_waitstatus wait_status;
671 /* Get the last target status returned by target_wait(). */
672 get_last_target_status (&wait_ptid, &wait_status);
674 /* If not stopped at a fork event, then there's nothing else to
676 if (wait_status.kind != TARGET_WAITKIND_FORKED
677 && wait_status.kind != TARGET_WAITKIND_VFORKED)
680 /* Check if we switched over from WAIT_PTID, since the event was
682 if (!ptid_equal (wait_ptid, minus_one_ptid)
683 && !ptid_equal (inferior_ptid, wait_ptid))
685 /* We did. Switch back to WAIT_PTID thread, to tell the
686 target to follow it (in either direction). We'll
687 afterwards refuse to resume, and inform the user what
689 switch_to_thread (wait_ptid);
694 tp = inferior_thread ();
696 /* If there were any forks/vforks that were caught and are now to be
697 followed, then do so now. */
698 switch (tp->pending_follow.kind)
700 case TARGET_WAITKIND_FORKED:
701 case TARGET_WAITKIND_VFORKED:
703 ptid_t parent, child;
705 /* If the user did a next/step, etc, over a fork call,
706 preserve the stepping state in the fork child. */
707 if (follow_child && should_resume)
709 step_resume_breakpoint = clone_momentary_breakpoint
710 (tp->control.step_resume_breakpoint);
711 step_range_start = tp->control.step_range_start;
712 step_range_end = tp->control.step_range_end;
713 step_frame_id = tp->control.step_frame_id;
714 exception_resume_breakpoint
715 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
716 command_interp = tp->control.command_interp;
718 /* For now, delete the parent's sr breakpoint, otherwise,
719 parent/child sr breakpoints are considered duplicates,
720 and the child version will not be installed. Remove
721 this when the breakpoints module becomes aware of
722 inferiors and address spaces. */
723 delete_step_resume_breakpoint (tp);
724 tp->control.step_range_start = 0;
725 tp->control.step_range_end = 0;
726 tp->control.step_frame_id = null_frame_id;
727 delete_exception_resume_breakpoint (tp);
728 tp->control.command_interp = NULL;
731 parent = inferior_ptid;
732 child = tp->pending_follow.value.related_pid;
734 /* Set up inferior(s) as specified by the caller, and tell the
735 target to do whatever is necessary to follow either parent
737 if (follow_fork_inferior (follow_child, detach_fork))
739 /* Target refused to follow, or there's some other reason
740 we shouldn't resume. */
745 /* This pending follow fork event is now handled, one way
746 or another. The previous selected thread may be gone
747 from the lists by now, but if it is still around, need
748 to clear the pending follow request. */
749 tp = find_thread_ptid (parent);
751 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
753 /* This makes sure we don't try to apply the "Switched
754 over from WAIT_PID" logic above. */
755 nullify_last_target_wait_ptid ();
757 /* If we followed the child, switch to it... */
760 switch_to_thread (child);
762 /* ... and preserve the stepping state, in case the
763 user was stepping over the fork call. */
766 tp = inferior_thread ();
767 tp->control.step_resume_breakpoint
768 = step_resume_breakpoint;
769 tp->control.step_range_start = step_range_start;
770 tp->control.step_range_end = step_range_end;
771 tp->control.step_frame_id = step_frame_id;
772 tp->control.exception_resume_breakpoint
773 = exception_resume_breakpoint;
774 tp->control.command_interp = command_interp;
778 /* If we get here, it was because we're trying to
779 resume from a fork catchpoint, but, the user
780 has switched threads away from the thread that
781 forked. In that case, the resume command
782 issued is most likely not applicable to the
783 child, so just warn, and refuse to resume. */
784 warning (_("Not resuming: switched threads "
785 "before following fork child.\n"));
788 /* Reset breakpoints in the child as appropriate. */
789 follow_inferior_reset_breakpoints ();
792 switch_to_thread (parent);
796 case TARGET_WAITKIND_SPURIOUS:
797 /* Nothing to follow. */
800 internal_error (__FILE__, __LINE__,
801 "Unexpected pending_follow.kind %d\n",
802 tp->pending_follow.kind);
806 return should_resume;
810 follow_inferior_reset_breakpoints (void)
812 struct thread_info *tp = inferior_thread ();
814 /* Was there a step_resume breakpoint? (There was if the user
815 did a "next" at the fork() call.) If so, explicitly reset its
816 thread number. Cloned step_resume breakpoints are disabled on
817 creation, so enable it here now that it is associated with the
820 step_resumes are a form of bp that are made to be per-thread.
821 Since we created the step_resume bp when the parent process
822 was being debugged, and now are switching to the child process,
823 from the breakpoint package's viewpoint, that's a switch of
824 "threads". We must update the bp's notion of which thread
825 it is for, or it'll be ignored when it triggers. */
827 if (tp->control.step_resume_breakpoint)
829 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
830 tp->control.step_resume_breakpoint->loc->enabled = 1;
833 /* Treat exception_resume breakpoints like step_resume breakpoints. */
834 if (tp->control.exception_resume_breakpoint)
836 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
837 tp->control.exception_resume_breakpoint->loc->enabled = 1;
840 /* Reinsert all breakpoints in the child. The user may have set
841 breakpoints after catching the fork, in which case those
842 were never set in the child, but only in the parent. This makes
843 sure the inserted breakpoints match the breakpoint list. */
845 breakpoint_re_set ();
846 insert_breakpoints ();
849 /* The child has exited or execed: resume threads of the parent the
850 user wanted to be executing. */
853 proceed_after_vfork_done (struct thread_info *thread,
856 int pid = * (int *) arg;
858 if (ptid_get_pid (thread->ptid) == pid
859 && is_running (thread->ptid)
860 && !is_executing (thread->ptid)
861 && !thread->stop_requested
862 && thread->suspend.stop_signal == GDB_SIGNAL_0)
865 fprintf_unfiltered (gdb_stdlog,
866 "infrun: resuming vfork parent thread %s\n",
867 target_pid_to_str (thread->ptid));
869 switch_to_thread (thread->ptid);
870 clear_proceed_status (0);
871 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0);
877 /* Called whenever we notice an exec or exit event, to handle
878 detaching or resuming a vfork parent. */
881 handle_vfork_child_exec_or_exit (int exec)
883 struct inferior *inf = current_inferior ();
885 if (inf->vfork_parent)
887 int resume_parent = -1;
889 /* This exec or exit marks the end of the shared memory region
890 between the parent and the child. If the user wanted to
891 detach from the parent, now is the time. */
893 if (inf->vfork_parent->pending_detach)
895 struct thread_info *tp;
896 struct cleanup *old_chain;
897 struct program_space *pspace;
898 struct address_space *aspace;
900 /* follow-fork child, detach-on-fork on. */
902 inf->vfork_parent->pending_detach = 0;
906 /* If we're handling a child exit, then inferior_ptid
907 points at the inferior's pid, not to a thread. */
908 old_chain = save_inferior_ptid ();
909 save_current_program_space ();
910 save_current_inferior ();
913 old_chain = save_current_space_and_thread ();
915 /* We're letting loose of the parent. */
916 tp = any_live_thread_of_process (inf->vfork_parent->pid);
917 switch_to_thread (tp->ptid);
919 /* We're about to detach from the parent, which implicitly
920 removes breakpoints from its address space. There's a
921 catch here: we want to reuse the spaces for the child,
922 but, parent/child are still sharing the pspace at this
923 point, although the exec in reality makes the kernel give
924 the child a fresh set of new pages. The problem here is
925 that the breakpoints module being unaware of this, would
926 likely chose the child process to write to the parent
927 address space. Swapping the child temporarily away from
928 the spaces has the desired effect. Yes, this is "sort
931 pspace = inf->pspace;
932 aspace = inf->aspace;
936 if (debug_infrun || info_verbose)
938 target_terminal_ours_for_output ();
942 fprintf_filtered (gdb_stdlog,
943 _("Detaching vfork parent process "
944 "%d after child exec.\n"),
945 inf->vfork_parent->pid);
949 fprintf_filtered (gdb_stdlog,
950 _("Detaching vfork parent process "
951 "%d after child exit.\n"),
952 inf->vfork_parent->pid);
956 target_detach (NULL, 0);
959 inf->pspace = pspace;
960 inf->aspace = aspace;
962 do_cleanups (old_chain);
966 /* We're staying attached to the parent, so, really give the
967 child a new address space. */
968 inf->pspace = add_program_space (maybe_new_address_space ());
969 inf->aspace = inf->pspace->aspace;
971 set_current_program_space (inf->pspace);
973 resume_parent = inf->vfork_parent->pid;
975 /* Break the bonds. */
976 inf->vfork_parent->vfork_child = NULL;
980 struct cleanup *old_chain;
981 struct program_space *pspace;
983 /* If this is a vfork child exiting, then the pspace and
984 aspaces were shared with the parent. Since we're
985 reporting the process exit, we'll be mourning all that is
986 found in the address space, and switching to null_ptid,
987 preparing to start a new inferior. But, since we don't
988 want to clobber the parent's address/program spaces, we
989 go ahead and create a new one for this exiting
992 /* Switch to null_ptid, so that clone_program_space doesn't want
993 to read the selected frame of a dead process. */
994 old_chain = save_inferior_ptid ();
995 inferior_ptid = null_ptid;
997 /* This inferior is dead, so avoid giving the breakpoints
998 module the option to write through to it (cloning a
999 program space resets breakpoints). */
1002 pspace = add_program_space (maybe_new_address_space ());
1003 set_current_program_space (pspace);
1005 inf->symfile_flags = SYMFILE_NO_READ;
1006 clone_program_space (pspace, inf->vfork_parent->pspace);
1007 inf->pspace = pspace;
1008 inf->aspace = pspace->aspace;
1010 /* Put back inferior_ptid. We'll continue mourning this
1012 do_cleanups (old_chain);
1014 resume_parent = inf->vfork_parent->pid;
1015 /* Break the bonds. */
1016 inf->vfork_parent->vfork_child = NULL;
1019 inf->vfork_parent = NULL;
1021 gdb_assert (current_program_space == inf->pspace);
1023 if (non_stop && resume_parent != -1)
1025 /* If the user wanted the parent to be running, let it go
1027 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
1030 fprintf_unfiltered (gdb_stdlog,
1031 "infrun: resuming vfork parent process %d\n",
1034 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1036 do_cleanups (old_chain);
1041 /* Enum strings for "set|show follow-exec-mode". */
1043 static const char follow_exec_mode_new[] = "new";
1044 static const char follow_exec_mode_same[] = "same";
1045 static const char *const follow_exec_mode_names[] =
1047 follow_exec_mode_new,
1048 follow_exec_mode_same,
1052 static const char *follow_exec_mode_string = follow_exec_mode_same;
1054 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1055 struct cmd_list_element *c, const char *value)
1057 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1060 /* EXECD_PATHNAME is assumed to be non-NULL. */
1063 follow_exec (ptid_t pid, char *execd_pathname)
1065 struct thread_info *th = inferior_thread ();
1066 struct inferior *inf = current_inferior ();
1068 /* This is an exec event that we actually wish to pay attention to.
1069 Refresh our symbol table to the newly exec'd program, remove any
1070 momentary bp's, etc.
1072 If there are breakpoints, they aren't really inserted now,
1073 since the exec() transformed our inferior into a fresh set
1076 We want to preserve symbolic breakpoints on the list, since
1077 we have hopes that they can be reset after the new a.out's
1078 symbol table is read.
1080 However, any "raw" breakpoints must be removed from the list
1081 (e.g., the solib bp's), since their address is probably invalid
1084 And, we DON'T want to call delete_breakpoints() here, since
1085 that may write the bp's "shadow contents" (the instruction
1086 value that was overwritten witha TRAP instruction). Since
1087 we now have a new a.out, those shadow contents aren't valid. */
1089 mark_breakpoints_out ();
1091 update_breakpoints_after_exec ();
1093 /* If there was one, it's gone now. We cannot truly step-to-next
1094 statement through an exec(). */
1095 th->control.step_resume_breakpoint = NULL;
1096 th->control.exception_resume_breakpoint = NULL;
1097 th->control.single_step_breakpoints = NULL;
1098 th->control.step_range_start = 0;
1099 th->control.step_range_end = 0;
1101 /* The target reports the exec event to the main thread, even if
1102 some other thread does the exec, and even if the main thread was
1103 already stopped --- if debugging in non-stop mode, it's possible
1104 the user had the main thread held stopped in the previous image
1105 --- release it now. This is the same behavior as step-over-exec
1106 with scheduler-locking on in all-stop mode. */
1107 th->stop_requested = 0;
1109 /* What is this a.out's name? */
1110 printf_unfiltered (_("%s is executing new program: %s\n"),
1111 target_pid_to_str (inferior_ptid),
1114 /* We've followed the inferior through an exec. Therefore, the
1115 inferior has essentially been killed & reborn. */
1117 gdb_flush (gdb_stdout);
1119 breakpoint_init_inferior (inf_execd);
1121 if (gdb_sysroot && *gdb_sysroot)
1123 char *name = alloca (strlen (gdb_sysroot)
1124 + strlen (execd_pathname)
1127 strcpy (name, gdb_sysroot);
1128 strcat (name, execd_pathname);
1129 execd_pathname = name;
1132 /* Reset the shared library package. This ensures that we get a
1133 shlib event when the child reaches "_start", at which point the
1134 dld will have had a chance to initialize the child. */
1135 /* Also, loading a symbol file below may trigger symbol lookups, and
1136 we don't want those to be satisfied by the libraries of the
1137 previous incarnation of this process. */
1138 no_shared_libraries (NULL, 0);
1140 if (follow_exec_mode_string == follow_exec_mode_new)
1142 struct program_space *pspace;
1144 /* The user wants to keep the old inferior and program spaces
1145 around. Create a new fresh one, and switch to it. */
1147 inf = add_inferior (current_inferior ()->pid);
1148 pspace = add_program_space (maybe_new_address_space ());
1149 inf->pspace = pspace;
1150 inf->aspace = pspace->aspace;
1152 exit_inferior_num_silent (current_inferior ()->num);
1154 set_current_inferior (inf);
1155 set_current_program_space (pspace);
1159 /* The old description may no longer be fit for the new image.
1160 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1161 old description; we'll read a new one below. No need to do
1162 this on "follow-exec-mode new", as the old inferior stays
1163 around (its description is later cleared/refetched on
1165 target_clear_description ();
1168 gdb_assert (current_program_space == inf->pspace);
1170 /* That a.out is now the one to use. */
1171 exec_file_attach (execd_pathname, 0);
1173 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
1174 (Position Independent Executable) main symbol file will get applied by
1175 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
1176 the breakpoints with the zero displacement. */
1178 symbol_file_add (execd_pathname,
1180 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
1183 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
1184 set_initial_language ();
1186 /* If the target can specify a description, read it. Must do this
1187 after flipping to the new executable (because the target supplied
1188 description must be compatible with the executable's
1189 architecture, and the old executable may e.g., be 32-bit, while
1190 the new one 64-bit), and before anything involving memory or
1192 target_find_description ();
1194 solib_create_inferior_hook (0);
1196 jit_inferior_created_hook ();
1198 breakpoint_re_set ();
1200 /* Reinsert all breakpoints. (Those which were symbolic have
1201 been reset to the proper address in the new a.out, thanks
1202 to symbol_file_command...). */
1203 insert_breakpoints ();
1205 /* The next resume of this inferior should bring it to the shlib
1206 startup breakpoints. (If the user had also set bp's on
1207 "main" from the old (parent) process, then they'll auto-
1208 matically get reset there in the new process.). */
1211 /* Info about an instruction that is being stepped over. */
1213 struct step_over_info
1215 /* If we're stepping past a breakpoint, this is the address space
1216 and address of the instruction the breakpoint is set at. We'll
1217 skip inserting all breakpoints here. Valid iff ASPACE is
1219 struct address_space *aspace;
1222 /* The instruction being stepped over triggers a nonsteppable
1223 watchpoint. If true, we'll skip inserting watchpoints. */
1224 int nonsteppable_watchpoint_p;
1227 /* The step-over info of the location that is being stepped over.
1229 Note that with async/breakpoint always-inserted mode, a user might
1230 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1231 being stepped over. As setting a new breakpoint inserts all
1232 breakpoints, we need to make sure the breakpoint being stepped over
1233 isn't inserted then. We do that by only clearing the step-over
1234 info when the step-over is actually finished (or aborted).
1236 Presently GDB can only step over one breakpoint at any given time.
1237 Given threads that can't run code in the same address space as the
1238 breakpoint's can't really miss the breakpoint, GDB could be taught
1239 to step-over at most one breakpoint per address space (so this info
1240 could move to the address space object if/when GDB is extended).
1241 The set of breakpoints being stepped over will normally be much
1242 smaller than the set of all breakpoints, so a flag in the
1243 breakpoint location structure would be wasteful. A separate list
1244 also saves complexity and run-time, as otherwise we'd have to go
1245 through all breakpoint locations clearing their flag whenever we
1246 start a new sequence. Similar considerations weigh against storing
1247 this info in the thread object. Plus, not all step overs actually
1248 have breakpoint locations -- e.g., stepping past a single-step
1249 breakpoint, or stepping to complete a non-continuable
1251 static struct step_over_info step_over_info;
1253 /* Record the address of the breakpoint/instruction we're currently
1257 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1258 int nonsteppable_watchpoint_p)
1260 step_over_info.aspace = aspace;
1261 step_over_info.address = address;
1262 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1265 /* Called when we're not longer stepping over a breakpoint / an
1266 instruction, so all breakpoints are free to be (re)inserted. */
1269 clear_step_over_info (void)
1271 step_over_info.aspace = NULL;
1272 step_over_info.address = 0;
1273 step_over_info.nonsteppable_watchpoint_p = 0;
1279 stepping_past_instruction_at (struct address_space *aspace,
1282 return (step_over_info.aspace != NULL
1283 && breakpoint_address_match (aspace, address,
1284 step_over_info.aspace,
1285 step_over_info.address));
1291 stepping_past_nonsteppable_watchpoint (void)
1293 return step_over_info.nonsteppable_watchpoint_p;
1296 /* Returns true if step-over info is valid. */
1299 step_over_info_valid_p (void)
1301 return (step_over_info.aspace != NULL
1302 || stepping_past_nonsteppable_watchpoint ());
1306 /* Displaced stepping. */
1308 /* In non-stop debugging mode, we must take special care to manage
1309 breakpoints properly; in particular, the traditional strategy for
1310 stepping a thread past a breakpoint it has hit is unsuitable.
1311 'Displaced stepping' is a tactic for stepping one thread past a
1312 breakpoint it has hit while ensuring that other threads running
1313 concurrently will hit the breakpoint as they should.
1315 The traditional way to step a thread T off a breakpoint in a
1316 multi-threaded program in all-stop mode is as follows:
1318 a0) Initially, all threads are stopped, and breakpoints are not
1320 a1) We single-step T, leaving breakpoints uninserted.
1321 a2) We insert breakpoints, and resume all threads.
1323 In non-stop debugging, however, this strategy is unsuitable: we
1324 don't want to have to stop all threads in the system in order to
1325 continue or step T past a breakpoint. Instead, we use displaced
1328 n0) Initially, T is stopped, other threads are running, and
1329 breakpoints are inserted.
1330 n1) We copy the instruction "under" the breakpoint to a separate
1331 location, outside the main code stream, making any adjustments
1332 to the instruction, register, and memory state as directed by
1334 n2) We single-step T over the instruction at its new location.
1335 n3) We adjust the resulting register and memory state as directed
1336 by T's architecture. This includes resetting T's PC to point
1337 back into the main instruction stream.
1340 This approach depends on the following gdbarch methods:
1342 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1343 indicate where to copy the instruction, and how much space must
1344 be reserved there. We use these in step n1.
1346 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1347 address, and makes any necessary adjustments to the instruction,
1348 register contents, and memory. We use this in step n1.
1350 - gdbarch_displaced_step_fixup adjusts registers and memory after
1351 we have successfuly single-stepped the instruction, to yield the
1352 same effect the instruction would have had if we had executed it
1353 at its original address. We use this in step n3.
1355 - gdbarch_displaced_step_free_closure provides cleanup.
1357 The gdbarch_displaced_step_copy_insn and
1358 gdbarch_displaced_step_fixup functions must be written so that
1359 copying an instruction with gdbarch_displaced_step_copy_insn,
1360 single-stepping across the copied instruction, and then applying
1361 gdbarch_displaced_insn_fixup should have the same effects on the
1362 thread's memory and registers as stepping the instruction in place
1363 would have. Exactly which responsibilities fall to the copy and
1364 which fall to the fixup is up to the author of those functions.
1366 See the comments in gdbarch.sh for details.
1368 Note that displaced stepping and software single-step cannot
1369 currently be used in combination, although with some care I think
1370 they could be made to. Software single-step works by placing
1371 breakpoints on all possible subsequent instructions; if the
1372 displaced instruction is a PC-relative jump, those breakpoints
1373 could fall in very strange places --- on pages that aren't
1374 executable, or at addresses that are not proper instruction
1375 boundaries. (We do generally let other threads run while we wait
1376 to hit the software single-step breakpoint, and they might
1377 encounter such a corrupted instruction.) One way to work around
1378 this would be to have gdbarch_displaced_step_copy_insn fully
1379 simulate the effect of PC-relative instructions (and return NULL)
1380 on architectures that use software single-stepping.
1382 In non-stop mode, we can have independent and simultaneous step
1383 requests, so more than one thread may need to simultaneously step
1384 over a breakpoint. The current implementation assumes there is
1385 only one scratch space per process. In this case, we have to
1386 serialize access to the scratch space. If thread A wants to step
1387 over a breakpoint, but we are currently waiting for some other
1388 thread to complete a displaced step, we leave thread A stopped and
1389 place it in the displaced_step_request_queue. Whenever a displaced
1390 step finishes, we pick the next thread in the queue and start a new
1391 displaced step operation on it. See displaced_step_prepare and
1392 displaced_step_fixup for details. */
1394 struct displaced_step_request
1397 struct displaced_step_request *next;
1400 /* Per-inferior displaced stepping state. */
1401 struct displaced_step_inferior_state
1403 /* Pointer to next in linked list. */
1404 struct displaced_step_inferior_state *next;
1406 /* The process this displaced step state refers to. */
1409 /* A queue of pending displaced stepping requests. One entry per
1410 thread that needs to do a displaced step. */
1411 struct displaced_step_request *step_request_queue;
1413 /* If this is not null_ptid, this is the thread carrying out a
1414 displaced single-step in process PID. This thread's state will
1415 require fixing up once it has completed its step. */
1418 /* The architecture the thread had when we stepped it. */
1419 struct gdbarch *step_gdbarch;
1421 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1422 for post-step cleanup. */
1423 struct displaced_step_closure *step_closure;
1425 /* The address of the original instruction, and the copy we
1427 CORE_ADDR step_original, step_copy;
1429 /* Saved contents of copy area. */
1430 gdb_byte *step_saved_copy;
1433 /* The list of states of processes involved in displaced stepping
1435 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1437 /* Get the displaced stepping state of process PID. */
1439 static struct displaced_step_inferior_state *
1440 get_displaced_stepping_state (int pid)
1442 struct displaced_step_inferior_state *state;
1444 for (state = displaced_step_inferior_states;
1446 state = state->next)
1447 if (state->pid == pid)
1453 /* Add a new displaced stepping state for process PID to the displaced
1454 stepping state list, or return a pointer to an already existing
1455 entry, if it already exists. Never returns NULL. */
1457 static struct displaced_step_inferior_state *
1458 add_displaced_stepping_state (int pid)
1460 struct displaced_step_inferior_state *state;
1462 for (state = displaced_step_inferior_states;
1464 state = state->next)
1465 if (state->pid == pid)
1468 state = xcalloc (1, sizeof (*state));
1470 state->next = displaced_step_inferior_states;
1471 displaced_step_inferior_states = state;
1476 /* If inferior is in displaced stepping, and ADDR equals to starting address
1477 of copy area, return corresponding displaced_step_closure. Otherwise,
1480 struct displaced_step_closure*
1481 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1483 struct displaced_step_inferior_state *displaced
1484 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1486 /* If checking the mode of displaced instruction in copy area. */
1487 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1488 && (displaced->step_copy == addr))
1489 return displaced->step_closure;
1494 /* Remove the displaced stepping state of process PID. */
1497 remove_displaced_stepping_state (int pid)
1499 struct displaced_step_inferior_state *it, **prev_next_p;
1501 gdb_assert (pid != 0);
1503 it = displaced_step_inferior_states;
1504 prev_next_p = &displaced_step_inferior_states;
1509 *prev_next_p = it->next;
1514 prev_next_p = &it->next;
1520 infrun_inferior_exit (struct inferior *inf)
1522 remove_displaced_stepping_state (inf->pid);
1525 /* If ON, and the architecture supports it, GDB will use displaced
1526 stepping to step over breakpoints. If OFF, or if the architecture
1527 doesn't support it, GDB will instead use the traditional
1528 hold-and-step approach. If AUTO (which is the default), GDB will
1529 decide which technique to use to step over breakpoints depending on
1530 which of all-stop or non-stop mode is active --- displaced stepping
1531 in non-stop mode; hold-and-step in all-stop mode. */
1533 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1536 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1537 struct cmd_list_element *c,
1540 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1541 fprintf_filtered (file,
1542 _("Debugger's willingness to use displaced stepping "
1543 "to step over breakpoints is %s (currently %s).\n"),
1544 value, non_stop ? "on" : "off");
1546 fprintf_filtered (file,
1547 _("Debugger's willingness to use displaced stepping "
1548 "to step over breakpoints is %s.\n"), value);
1551 /* Return non-zero if displaced stepping can/should be used to step
1552 over breakpoints. */
1555 use_displaced_stepping (struct gdbarch *gdbarch)
1557 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1558 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1559 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1560 && find_record_target () == NULL);
1563 /* Clean out any stray displaced stepping state. */
1565 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1567 /* Indicate that there is no cleanup pending. */
1568 displaced->step_ptid = null_ptid;
1570 if (displaced->step_closure)
1572 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1573 displaced->step_closure);
1574 displaced->step_closure = NULL;
1579 displaced_step_clear_cleanup (void *arg)
1581 struct displaced_step_inferior_state *state = arg;
1583 displaced_step_clear (state);
1586 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1588 displaced_step_dump_bytes (struct ui_file *file,
1589 const gdb_byte *buf,
1594 for (i = 0; i < len; i++)
1595 fprintf_unfiltered (file, "%02x ", buf[i]);
1596 fputs_unfiltered ("\n", file);
1599 /* Prepare to single-step, using displaced stepping.
1601 Note that we cannot use displaced stepping when we have a signal to
1602 deliver. If we have a signal to deliver and an instruction to step
1603 over, then after the step, there will be no indication from the
1604 target whether the thread entered a signal handler or ignored the
1605 signal and stepped over the instruction successfully --- both cases
1606 result in a simple SIGTRAP. In the first case we mustn't do a
1607 fixup, and in the second case we must --- but we can't tell which.
1608 Comments in the code for 'random signals' in handle_inferior_event
1609 explain how we handle this case instead.
1611 Returns 1 if preparing was successful -- this thread is going to be
1612 stepped now; or 0 if displaced stepping this thread got queued. */
1614 displaced_step_prepare (ptid_t ptid)
1616 struct cleanup *old_cleanups, *ignore_cleanups;
1617 struct thread_info *tp = find_thread_ptid (ptid);
1618 struct regcache *regcache = get_thread_regcache (ptid);
1619 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1620 CORE_ADDR original, copy;
1622 struct displaced_step_closure *closure;
1623 struct displaced_step_inferior_state *displaced;
1626 /* We should never reach this function if the architecture does not
1627 support displaced stepping. */
1628 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1630 /* Disable range stepping while executing in the scratch pad. We
1631 want a single-step even if executing the displaced instruction in
1632 the scratch buffer lands within the stepping range (e.g., a
1634 tp->control.may_range_step = 0;
1636 /* We have to displaced step one thread at a time, as we only have
1637 access to a single scratch space per inferior. */
1639 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1641 if (!ptid_equal (displaced->step_ptid, null_ptid))
1643 /* Already waiting for a displaced step to finish. Defer this
1644 request and place in queue. */
1645 struct displaced_step_request *req, *new_req;
1647 if (debug_displaced)
1648 fprintf_unfiltered (gdb_stdlog,
1649 "displaced: defering step of %s\n",
1650 target_pid_to_str (ptid));
1652 new_req = xmalloc (sizeof (*new_req));
1653 new_req->ptid = ptid;
1654 new_req->next = NULL;
1656 if (displaced->step_request_queue)
1658 for (req = displaced->step_request_queue;
1662 req->next = new_req;
1665 displaced->step_request_queue = new_req;
1671 if (debug_displaced)
1672 fprintf_unfiltered (gdb_stdlog,
1673 "displaced: stepping %s now\n",
1674 target_pid_to_str (ptid));
1677 displaced_step_clear (displaced);
1679 old_cleanups = save_inferior_ptid ();
1680 inferior_ptid = ptid;
1682 original = regcache_read_pc (regcache);
1684 copy = gdbarch_displaced_step_location (gdbarch);
1685 len = gdbarch_max_insn_length (gdbarch);
1687 /* Save the original contents of the copy area. */
1688 displaced->step_saved_copy = xmalloc (len);
1689 ignore_cleanups = make_cleanup (free_current_contents,
1690 &displaced->step_saved_copy);
1691 status = target_read_memory (copy, displaced->step_saved_copy, len);
1693 throw_error (MEMORY_ERROR,
1694 _("Error accessing memory address %s (%s) for "
1695 "displaced-stepping scratch space."),
1696 paddress (gdbarch, copy), safe_strerror (status));
1697 if (debug_displaced)
1699 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1700 paddress (gdbarch, copy));
1701 displaced_step_dump_bytes (gdb_stdlog,
1702 displaced->step_saved_copy,
1706 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1707 original, copy, regcache);
1709 /* We don't support the fully-simulated case at present. */
1710 gdb_assert (closure);
1712 /* Save the information we need to fix things up if the step
1714 displaced->step_ptid = ptid;
1715 displaced->step_gdbarch = gdbarch;
1716 displaced->step_closure = closure;
1717 displaced->step_original = original;
1718 displaced->step_copy = copy;
1720 make_cleanup (displaced_step_clear_cleanup, displaced);
1722 /* Resume execution at the copy. */
1723 regcache_write_pc (regcache, copy);
1725 discard_cleanups (ignore_cleanups);
1727 do_cleanups (old_cleanups);
1729 if (debug_displaced)
1730 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1731 paddress (gdbarch, copy));
1737 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1738 const gdb_byte *myaddr, int len)
1740 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1742 inferior_ptid = ptid;
1743 write_memory (memaddr, myaddr, len);
1744 do_cleanups (ptid_cleanup);
1747 /* Restore the contents of the copy area for thread PTID. */
1750 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1753 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1755 write_memory_ptid (ptid, displaced->step_copy,
1756 displaced->step_saved_copy, len);
1757 if (debug_displaced)
1758 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1759 target_pid_to_str (ptid),
1760 paddress (displaced->step_gdbarch,
1761 displaced->step_copy));
1765 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1767 struct cleanup *old_cleanups;
1768 struct displaced_step_inferior_state *displaced
1769 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1771 /* Was any thread of this process doing a displaced step? */
1772 if (displaced == NULL)
1775 /* Was this event for the pid we displaced? */
1776 if (ptid_equal (displaced->step_ptid, null_ptid)
1777 || ! ptid_equal (displaced->step_ptid, event_ptid))
1780 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1782 displaced_step_restore (displaced, displaced->step_ptid);
1784 /* Did the instruction complete successfully? */
1785 if (signal == GDB_SIGNAL_TRAP)
1787 /* Fix up the resulting state. */
1788 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1789 displaced->step_closure,
1790 displaced->step_original,
1791 displaced->step_copy,
1792 get_thread_regcache (displaced->step_ptid));
1796 /* Since the instruction didn't complete, all we can do is
1798 struct regcache *regcache = get_thread_regcache (event_ptid);
1799 CORE_ADDR pc = regcache_read_pc (regcache);
1801 pc = displaced->step_original + (pc - displaced->step_copy);
1802 regcache_write_pc (regcache, pc);
1805 do_cleanups (old_cleanups);
1807 displaced->step_ptid = null_ptid;
1809 /* Are there any pending displaced stepping requests? If so, run
1810 one now. Leave the state object around, since we're likely to
1811 need it again soon. */
1812 while (displaced->step_request_queue)
1814 struct displaced_step_request *head;
1816 struct regcache *regcache;
1817 struct gdbarch *gdbarch;
1818 CORE_ADDR actual_pc;
1819 struct address_space *aspace;
1821 head = displaced->step_request_queue;
1823 displaced->step_request_queue = head->next;
1826 context_switch (ptid);
1828 regcache = get_thread_regcache (ptid);
1829 actual_pc = regcache_read_pc (regcache);
1830 aspace = get_regcache_aspace (regcache);
1832 if (breakpoint_here_p (aspace, actual_pc))
1834 if (debug_displaced)
1835 fprintf_unfiltered (gdb_stdlog,
1836 "displaced: stepping queued %s now\n",
1837 target_pid_to_str (ptid));
1839 displaced_step_prepare (ptid);
1841 gdbarch = get_regcache_arch (regcache);
1843 if (debug_displaced)
1845 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1848 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1849 paddress (gdbarch, actual_pc));
1850 read_memory (actual_pc, buf, sizeof (buf));
1851 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1854 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1855 displaced->step_closure))
1856 target_resume (ptid, 1, GDB_SIGNAL_0);
1858 target_resume (ptid, 0, GDB_SIGNAL_0);
1860 /* Done, we're stepping a thread. */
1866 struct thread_info *tp = inferior_thread ();
1868 /* The breakpoint we were sitting under has since been
1870 tp->control.trap_expected = 0;
1872 /* Go back to what we were trying to do. */
1873 step = currently_stepping (tp);
1875 if (debug_displaced)
1876 fprintf_unfiltered (gdb_stdlog,
1877 "displaced: breakpoint is gone: %s, step(%d)\n",
1878 target_pid_to_str (tp->ptid), step);
1880 target_resume (ptid, step, GDB_SIGNAL_0);
1881 tp->suspend.stop_signal = GDB_SIGNAL_0;
1883 /* This request was discarded. See if there's any other
1884 thread waiting for its turn. */
1889 /* Update global variables holding ptids to hold NEW_PTID if they were
1890 holding OLD_PTID. */
1892 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1894 struct displaced_step_request *it;
1895 struct displaced_step_inferior_state *displaced;
1897 if (ptid_equal (inferior_ptid, old_ptid))
1898 inferior_ptid = new_ptid;
1900 for (displaced = displaced_step_inferior_states;
1902 displaced = displaced->next)
1904 if (ptid_equal (displaced->step_ptid, old_ptid))
1905 displaced->step_ptid = new_ptid;
1907 for (it = displaced->step_request_queue; it; it = it->next)
1908 if (ptid_equal (it->ptid, old_ptid))
1909 it->ptid = new_ptid;
1916 /* Things to clean up if we QUIT out of resume (). */
1918 resume_cleanups (void *ignore)
1920 if (!ptid_equal (inferior_ptid, null_ptid))
1921 delete_single_step_breakpoints (inferior_thread ());
1926 static const char schedlock_off[] = "off";
1927 static const char schedlock_on[] = "on";
1928 static const char schedlock_step[] = "step";
1929 static const char *const scheduler_enums[] = {
1935 static const char *scheduler_mode = schedlock_off;
1937 show_scheduler_mode (struct ui_file *file, int from_tty,
1938 struct cmd_list_element *c, const char *value)
1940 fprintf_filtered (file,
1941 _("Mode for locking scheduler "
1942 "during execution is \"%s\".\n"),
1947 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1949 if (!target_can_lock_scheduler)
1951 scheduler_mode = schedlock_off;
1952 error (_("Target '%s' cannot support this command."), target_shortname);
1956 /* True if execution commands resume all threads of all processes by
1957 default; otherwise, resume only threads of the current inferior
1959 int sched_multi = 0;
1961 /* Try to setup for software single stepping over the specified location.
1962 Return 1 if target_resume() should use hardware single step.
1964 GDBARCH the current gdbarch.
1965 PC the location to step over. */
1968 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1972 if (execution_direction == EXEC_FORWARD
1973 && gdbarch_software_single_step_p (gdbarch)
1974 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1982 user_visible_resume_ptid (int step)
1984 /* By default, resume all threads of all processes. */
1985 ptid_t resume_ptid = RESUME_ALL;
1987 /* Maybe resume only all threads of the current process. */
1988 if (!sched_multi && target_supports_multi_process ())
1990 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1993 /* Maybe resume a single thread after all. */
1996 /* With non-stop mode on, threads are always handled
1998 resume_ptid = inferior_ptid;
2000 else if ((scheduler_mode == schedlock_on)
2001 || (scheduler_mode == schedlock_step && step))
2003 /* User-settable 'scheduler' mode requires solo thread resume. */
2004 resume_ptid = inferior_ptid;
2007 /* We may actually resume fewer threads at first, e.g., if a thread
2008 is stopped at a breakpoint that needs stepping-off, but that
2009 should not be visible to the user/frontend, and neither should
2010 the frontend/user be allowed to proceed any of the threads that
2011 happen to be stopped for internal run control handling, if a
2012 previous command wanted them resumed. */
2016 /* Resume the inferior, but allow a QUIT. This is useful if the user
2017 wants to interrupt some lengthy single-stepping operation
2018 (for child processes, the SIGINT goes to the inferior, and so
2019 we get a SIGINT random_signal, but for remote debugging and perhaps
2020 other targets, that's not true).
2022 STEP nonzero if we should step (zero to continue instead).
2023 SIG is the signal to give the inferior (zero for none). */
2025 resume (int step, enum gdb_signal sig)
2027 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2028 struct regcache *regcache = get_current_regcache ();
2029 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2030 struct thread_info *tp = inferior_thread ();
2031 CORE_ADDR pc = regcache_read_pc (regcache);
2032 struct address_space *aspace = get_regcache_aspace (regcache);
2034 /* From here on, this represents the caller's step vs continue
2035 request, while STEP represents what we'll actually request the
2036 target to do. STEP can decay from a step to a continue, if e.g.,
2037 we need to implement single-stepping with breakpoints (software
2038 single-step). When deciding whether "set scheduler-locking step"
2039 applies, it's the callers intention that counts. */
2040 const int entry_step = step;
2044 if (current_inferior ()->waiting_for_vfork_done)
2046 /* Don't try to single-step a vfork parent that is waiting for
2047 the child to get out of the shared memory region (by exec'ing
2048 or exiting). This is particularly important on software
2049 single-step archs, as the child process would trip on the
2050 software single step breakpoint inserted for the parent
2051 process. Since the parent will not actually execute any
2052 instruction until the child is out of the shared region (such
2053 are vfork's semantics), it is safe to simply continue it.
2054 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2055 the parent, and tell it to `keep_going', which automatically
2056 re-sets it stepping. */
2058 fprintf_unfiltered (gdb_stdlog,
2059 "infrun: resume : clear step\n");
2064 fprintf_unfiltered (gdb_stdlog,
2065 "infrun: resume (step=%d, signal=%s), "
2066 "trap_expected=%d, current thread [%s] at %s\n",
2067 step, gdb_signal_to_symbol_string (sig),
2068 tp->control.trap_expected,
2069 target_pid_to_str (inferior_ptid),
2070 paddress (gdbarch, pc));
2072 /* Normally, by the time we reach `resume', the breakpoints are either
2073 removed or inserted, as appropriate. The exception is if we're sitting
2074 at a permanent breakpoint; we need to step over it, but permanent
2075 breakpoints can't be removed. So we have to test for it here. */
2076 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2078 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
2079 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2082 The program is stopped at a permanent breakpoint, but GDB does not know\n\
2083 how to step past a permanent breakpoint on this architecture. Try using\n\
2084 a command like `return' or `jump' to continue execution."));
2087 /* If we have a breakpoint to step over, make sure to do a single
2088 step only. Same if we have software watchpoints. */
2089 if (tp->control.trap_expected || bpstat_should_step ())
2090 tp->control.may_range_step = 0;
2092 /* If enabled, step over breakpoints by executing a copy of the
2093 instruction at a different address.
2095 We can't use displaced stepping when we have a signal to deliver;
2096 the comments for displaced_step_prepare explain why. The
2097 comments in the handle_inferior event for dealing with 'random
2098 signals' explain what we do instead.
2100 We can't use displaced stepping when we are waiting for vfork_done
2101 event, displaced stepping breaks the vfork child similarly as single
2102 step software breakpoint. */
2103 if (use_displaced_stepping (gdbarch)
2104 && tp->control.trap_expected
2105 && sig == GDB_SIGNAL_0
2106 && !current_inferior ()->waiting_for_vfork_done)
2108 struct displaced_step_inferior_state *displaced;
2110 if (!displaced_step_prepare (inferior_ptid))
2112 /* Got placed in displaced stepping queue. Will be resumed
2113 later when all the currently queued displaced stepping
2114 requests finish. The thread is not executing at this
2115 point, and the call to set_executing will be made later.
2116 But we need to call set_running here, since from the
2117 user/frontend's point of view, threads were set running.
2118 Unless we're calling an inferior function, as in that
2119 case we pretend the inferior doesn't run at all. */
2120 if (!tp->control.in_infcall)
2121 set_running (user_visible_resume_ptid (entry_step), 1);
2122 discard_cleanups (old_cleanups);
2126 /* Update pc to reflect the new address from which we will execute
2127 instructions due to displaced stepping. */
2128 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2130 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2131 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2132 displaced->step_closure);
2135 /* Do we need to do it the hard way, w/temp breakpoints? */
2137 step = maybe_software_singlestep (gdbarch, pc);
2139 /* Currently, our software single-step implementation leads to different
2140 results than hardware single-stepping in one situation: when stepping
2141 into delivering a signal which has an associated signal handler,
2142 hardware single-step will stop at the first instruction of the handler,
2143 while software single-step will simply skip execution of the handler.
2145 For now, this difference in behavior is accepted since there is no
2146 easy way to actually implement single-stepping into a signal handler
2147 without kernel support.
2149 However, there is one scenario where this difference leads to follow-on
2150 problems: if we're stepping off a breakpoint by removing all breakpoints
2151 and then single-stepping. In this case, the software single-step
2152 behavior means that even if there is a *breakpoint* in the signal
2153 handler, GDB still would not stop.
2155 Fortunately, we can at least fix this particular issue. We detect
2156 here the case where we are about to deliver a signal while software
2157 single-stepping with breakpoints removed. In this situation, we
2158 revert the decisions to remove all breakpoints and insert single-
2159 step breakpoints, and instead we install a step-resume breakpoint
2160 at the current address, deliver the signal without stepping, and
2161 once we arrive back at the step-resume breakpoint, actually step
2162 over the breakpoint we originally wanted to step over. */
2163 if (thread_has_single_step_breakpoints_set (tp)
2164 && sig != GDB_SIGNAL_0
2165 && step_over_info_valid_p ())
2167 /* If we have nested signals or a pending signal is delivered
2168 immediately after a handler returns, might might already have
2169 a step-resume breakpoint set on the earlier handler. We cannot
2170 set another step-resume breakpoint; just continue on until the
2171 original breakpoint is hit. */
2172 if (tp->control.step_resume_breakpoint == NULL)
2174 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2175 tp->step_after_step_resume_breakpoint = 1;
2178 delete_single_step_breakpoints (tp);
2180 clear_step_over_info ();
2181 tp->control.trap_expected = 0;
2183 insert_breakpoints ();
2186 /* If STEP is set, it's a request to use hardware stepping
2187 facilities. But in that case, we should never
2188 use singlestep breakpoint. */
2189 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2191 /* Decide the set of threads to ask the target to resume. Start
2192 by assuming everything will be resumed, than narrow the set
2193 by applying increasingly restricting conditions. */
2194 resume_ptid = user_visible_resume_ptid (entry_step);
2196 /* Even if RESUME_PTID is a wildcard, and we end up resuming less
2197 (e.g., we might need to step over a breakpoint), from the
2198 user/frontend's point of view, all threads in RESUME_PTID are now
2199 running. Unless we're calling an inferior function, as in that
2200 case pretend we inferior doesn't run at all. */
2201 if (!tp->control.in_infcall)
2202 set_running (resume_ptid, 1);
2204 /* Maybe resume a single thread after all. */
2205 if ((step || thread_has_single_step_breakpoints_set (tp))
2206 && tp->control.trap_expected)
2208 /* We're allowing a thread to run past a breakpoint it has
2209 hit, by single-stepping the thread with the breakpoint
2210 removed. In which case, we need to single-step only this
2211 thread, and keep others stopped, as they can miss this
2212 breakpoint if allowed to run. */
2213 resume_ptid = inferior_ptid;
2216 if (execution_direction != EXEC_REVERSE
2217 && step && breakpoint_inserted_here_p (aspace, pc))
2219 /* The only case we currently need to step a breakpoint
2220 instruction is when we have a signal to deliver. See
2221 handle_signal_stop where we handle random signals that could
2222 take out us out of the stepping range. Normally, in that
2223 case we end up continuing (instead of stepping) over the
2224 signal handler with a breakpoint at PC, but there are cases
2225 where we should _always_ single-step, even if we have a
2226 step-resume breakpoint, like when a software watchpoint is
2227 set. Assuming single-stepping and delivering a signal at the
2228 same time would takes us to the signal handler, then we could
2229 have removed the breakpoint at PC to step over it. However,
2230 some hardware step targets (like e.g., Mac OS) can't step
2231 into signal handlers, and for those, we need to leave the
2232 breakpoint at PC inserted, as otherwise if the handler
2233 recurses and executes PC again, it'll miss the breakpoint.
2234 So we leave the breakpoint inserted anyway, but we need to
2235 record that we tried to step a breakpoint instruction, so
2236 that adjust_pc_after_break doesn't end up confused. */
2237 gdb_assert (sig != GDB_SIGNAL_0);
2239 tp->stepped_breakpoint = 1;
2241 /* Most targets can step a breakpoint instruction, thus
2242 executing it normally. But if this one cannot, just
2243 continue and we will hit it anyway. */
2244 if (gdbarch_cannot_step_breakpoint (gdbarch))
2249 && use_displaced_stepping (gdbarch)
2250 && tp->control.trap_expected)
2252 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
2253 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2254 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2257 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2258 paddress (resume_gdbarch, actual_pc));
2259 read_memory (actual_pc, buf, sizeof (buf));
2260 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2263 if (tp->control.may_range_step)
2265 /* If we're resuming a thread with the PC out of the step
2266 range, then we're doing some nested/finer run control
2267 operation, like stepping the thread out of the dynamic
2268 linker or the displaced stepping scratch pad. We
2269 shouldn't have allowed a range step then. */
2270 gdb_assert (pc_in_thread_step_range (pc, tp));
2273 /* Install inferior's terminal modes. */
2274 target_terminal_inferior ();
2276 /* Avoid confusing the next resume, if the next stop/resume
2277 happens to apply to another thread. */
2278 tp->suspend.stop_signal = GDB_SIGNAL_0;
2280 /* Advise target which signals may be handled silently. If we have
2281 removed breakpoints because we are stepping over one (in any
2282 thread), we need to receive all signals to avoid accidentally
2283 skipping a breakpoint during execution of a signal handler. */
2284 if (step_over_info_valid_p ())
2285 target_pass_signals (0, NULL);
2287 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2289 target_resume (resume_ptid, step, sig);
2291 discard_cleanups (old_cleanups);
2296 /* Clear out all variables saying what to do when inferior is continued.
2297 First do this, then set the ones you want, then call `proceed'. */
2300 clear_proceed_status_thread (struct thread_info *tp)
2303 fprintf_unfiltered (gdb_stdlog,
2304 "infrun: clear_proceed_status_thread (%s)\n",
2305 target_pid_to_str (tp->ptid));
2307 /* If this signal should not be seen by program, give it zero.
2308 Used for debugging signals. */
2309 if (!signal_pass_state (tp->suspend.stop_signal))
2310 tp->suspend.stop_signal = GDB_SIGNAL_0;
2312 tp->control.trap_expected = 0;
2313 tp->control.step_range_start = 0;
2314 tp->control.step_range_end = 0;
2315 tp->control.may_range_step = 0;
2316 tp->control.step_frame_id = null_frame_id;
2317 tp->control.step_stack_frame_id = null_frame_id;
2318 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2319 tp->stop_requested = 0;
2321 tp->control.stop_step = 0;
2323 tp->control.proceed_to_finish = 0;
2325 tp->control.command_interp = NULL;
2327 /* Discard any remaining commands or status from previous stop. */
2328 bpstat_clear (&tp->control.stop_bpstat);
2332 clear_proceed_status (int step)
2336 struct thread_info *tp;
2339 resume_ptid = user_visible_resume_ptid (step);
2341 /* In all-stop mode, delete the per-thread status of all threads
2342 we're about to resume, implicitly and explicitly. */
2343 ALL_NON_EXITED_THREADS (tp)
2345 if (!ptid_match (tp->ptid, resume_ptid))
2347 clear_proceed_status_thread (tp);
2351 if (!ptid_equal (inferior_ptid, null_ptid))
2353 struct inferior *inferior;
2357 /* If in non-stop mode, only delete the per-thread status of
2358 the current thread. */
2359 clear_proceed_status_thread (inferior_thread ());
2362 inferior = current_inferior ();
2363 inferior->control.stop_soon = NO_STOP_QUIETLY;
2366 stop_after_trap = 0;
2368 clear_step_over_info ();
2370 observer_notify_about_to_proceed ();
2374 regcache_xfree (stop_registers);
2375 stop_registers = NULL;
2379 /* Returns true if TP is still stopped at a breakpoint that needs
2380 stepping-over in order to make progress. If the breakpoint is gone
2381 meanwhile, we can skip the whole step-over dance. */
2384 thread_still_needs_step_over (struct thread_info *tp)
2386 if (tp->stepping_over_breakpoint)
2388 struct regcache *regcache = get_thread_regcache (tp->ptid);
2390 if (breakpoint_here_p (get_regcache_aspace (regcache),
2391 regcache_read_pc (regcache)))
2394 tp->stepping_over_breakpoint = 0;
2400 /* Returns true if scheduler locking applies. STEP indicates whether
2401 we're about to do a step/next-like command to a thread. */
2404 schedlock_applies (int step)
2406 return (scheduler_mode == schedlock_on
2407 || (scheduler_mode == schedlock_step
2411 /* Look a thread other than EXCEPT that has previously reported a
2412 breakpoint event, and thus needs a step-over in order to make
2413 progress. Returns NULL is none is found. STEP indicates whether
2414 we're about to step the current thread, in order to decide whether
2415 "set scheduler-locking step" applies. */
2417 static struct thread_info *
2418 find_thread_needs_step_over (int step, struct thread_info *except)
2420 struct thread_info *tp, *current;
2422 /* With non-stop mode on, threads are always handled individually. */
2423 gdb_assert (! non_stop);
2425 current = inferior_thread ();
2427 /* If scheduler locking applies, we can avoid iterating over all
2429 if (schedlock_applies (step))
2431 if (except != current
2432 && thread_still_needs_step_over (current))
2438 ALL_NON_EXITED_THREADS (tp)
2440 /* Ignore the EXCEPT thread. */
2443 /* Ignore threads of processes we're not resuming. */
2445 && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
2448 if (thread_still_needs_step_over (tp))
2455 /* Basic routine for continuing the program in various fashions.
2457 ADDR is the address to resume at, or -1 for resume where stopped.
2458 SIGGNAL is the signal to give it, or 0 for none,
2459 or -1 for act according to how it stopped.
2460 STEP is nonzero if should trap after one instruction.
2461 -1 means return after that and print nothing.
2462 You should probably set various step_... variables
2463 before calling here, if you are stepping.
2465 You should call clear_proceed_status before calling proceed. */
2468 proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
2470 struct regcache *regcache;
2471 struct gdbarch *gdbarch;
2472 struct thread_info *tp;
2474 struct address_space *aspace;
2476 /* If we're stopped at a fork/vfork, follow the branch set by the
2477 "set follow-fork-mode" command; otherwise, we'll just proceed
2478 resuming the current thread. */
2479 if (!follow_fork ())
2481 /* The target for some reason decided not to resume. */
2483 if (target_can_async_p ())
2484 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2488 /* We'll update this if & when we switch to a new thread. */
2489 previous_inferior_ptid = inferior_ptid;
2491 regcache = get_current_regcache ();
2492 gdbarch = get_regcache_arch (regcache);
2493 aspace = get_regcache_aspace (regcache);
2494 pc = regcache_read_pc (regcache);
2495 tp = inferior_thread ();
2498 step_start_function = find_pc_function (pc);
2500 stop_after_trap = 1;
2502 /* Fill in with reasonable starting values. */
2503 init_thread_stepping_state (tp);
2505 if (addr == (CORE_ADDR) -1)
2507 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
2508 && execution_direction != EXEC_REVERSE)
2509 /* There is a breakpoint at the address we will resume at,
2510 step one instruction before inserting breakpoints so that
2511 we do not stop right away (and report a second hit at this
2514 Note, we don't do this in reverse, because we won't
2515 actually be executing the breakpoint insn anyway.
2516 We'll be (un-)executing the previous instruction. */
2517 tp->stepping_over_breakpoint = 1;
2518 else if (gdbarch_single_step_through_delay_p (gdbarch)
2519 && gdbarch_single_step_through_delay (gdbarch,
2520 get_current_frame ()))
2521 /* We stepped onto an instruction that needs to be stepped
2522 again before re-inserting the breakpoint, do so. */
2523 tp->stepping_over_breakpoint = 1;
2527 regcache_write_pc (regcache, addr);
2530 if (siggnal != GDB_SIGNAL_DEFAULT)
2531 tp->suspend.stop_signal = siggnal;
2533 /* Record the interpreter that issued the execution command that
2534 caused this thread to resume. If the top level interpreter is
2535 MI/async, and the execution command was a CLI command
2536 (next/step/etc.), we'll want to print stop event output to the MI
2537 console channel (the stepped-to line, etc.), as if the user
2538 entered the execution command on a real GDB console. */
2539 inferior_thread ()->control.command_interp = command_interp ();
2542 fprintf_unfiltered (gdb_stdlog,
2543 "infrun: proceed (addr=%s, signal=%s, step=%d)\n",
2544 paddress (gdbarch, addr),
2545 gdb_signal_to_symbol_string (siggnal), step);
2548 /* In non-stop, each thread is handled individually. The context
2549 must already be set to the right thread here. */
2553 struct thread_info *step_over;
2555 /* In a multi-threaded task we may select another thread and
2556 then continue or step.
2558 But if the old thread was stopped at a breakpoint, it will
2559 immediately cause another breakpoint stop without any
2560 execution (i.e. it will report a breakpoint hit incorrectly).
2561 So we must step over it first.
2563 Look for a thread other than the current (TP) that reported a
2564 breakpoint hit and hasn't been resumed yet since. */
2565 step_over = find_thread_needs_step_over (step, tp);
2566 if (step_over != NULL)
2569 fprintf_unfiltered (gdb_stdlog,
2570 "infrun: need to step-over [%s] first\n",
2571 target_pid_to_str (step_over->ptid));
2573 /* Store the prev_pc for the stepping thread too, needed by
2574 switch_back_to_stepping thread. */
2575 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2576 switch_to_thread (step_over->ptid);
2581 /* If we need to step over a breakpoint, and we're not using
2582 displaced stepping to do so, insert all breakpoints (watchpoints,
2583 etc.) but the one we're stepping over, step one instruction, and
2584 then re-insert the breakpoint when that step is finished. */
2585 if (tp->stepping_over_breakpoint && !use_displaced_stepping (gdbarch))
2587 struct regcache *regcache = get_current_regcache ();
2589 set_step_over_info (get_regcache_aspace (regcache),
2590 regcache_read_pc (regcache), 0);
2593 clear_step_over_info ();
2595 insert_breakpoints ();
2597 tp->control.trap_expected = tp->stepping_over_breakpoint;
2599 annotate_starting ();
2601 /* Make sure that output from GDB appears before output from the
2603 gdb_flush (gdb_stdout);
2605 /* Refresh prev_pc value just prior to resuming. This used to be
2606 done in stop_waiting, however, setting prev_pc there did not handle
2607 scenarios such as inferior function calls or returning from
2608 a function via the return command. In those cases, the prev_pc
2609 value was not set properly for subsequent commands. The prev_pc value
2610 is used to initialize the starting line number in the ecs. With an
2611 invalid value, the gdb next command ends up stopping at the position
2612 represented by the next line table entry past our start position.
2613 On platforms that generate one line table entry per line, this
2614 is not a problem. However, on the ia64, the compiler generates
2615 extraneous line table entries that do not increase the line number.
2616 When we issue the gdb next command on the ia64 after an inferior call
2617 or a return command, we often end up a few instructions forward, still
2618 within the original line we started.
2620 An attempt was made to refresh the prev_pc at the same time the
2621 execution_control_state is initialized (for instance, just before
2622 waiting for an inferior event). But this approach did not work
2623 because of platforms that use ptrace, where the pc register cannot
2624 be read unless the inferior is stopped. At that point, we are not
2625 guaranteed the inferior is stopped and so the regcache_read_pc() call
2626 can fail. Setting the prev_pc value here ensures the value is updated
2627 correctly when the inferior is stopped. */
2628 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2630 /* Resume inferior. */
2631 resume (tp->control.trap_expected || step || bpstat_should_step (),
2632 tp->suspend.stop_signal);
2634 /* Wait for it to stop (if not standalone)
2635 and in any case decode why it stopped, and act accordingly. */
2636 /* Do this only if we are not using the event loop, or if the target
2637 does not support asynchronous execution. */
2638 if (!target_can_async_p ())
2640 wait_for_inferior ();
2646 /* Start remote-debugging of a machine over a serial link. */
2649 start_remote (int from_tty)
2651 struct inferior *inferior;
2653 inferior = current_inferior ();
2654 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2656 /* Always go on waiting for the target, regardless of the mode. */
2657 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2658 indicate to wait_for_inferior that a target should timeout if
2659 nothing is returned (instead of just blocking). Because of this,
2660 targets expecting an immediate response need to, internally, set
2661 things up so that the target_wait() is forced to eventually
2663 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2664 differentiate to its caller what the state of the target is after
2665 the initial open has been performed. Here we're assuming that
2666 the target has stopped. It should be possible to eventually have
2667 target_open() return to the caller an indication that the target
2668 is currently running and GDB state should be set to the same as
2669 for an async run. */
2670 wait_for_inferior ();
2672 /* Now that the inferior has stopped, do any bookkeeping like
2673 loading shared libraries. We want to do this before normal_stop,
2674 so that the displayed frame is up to date. */
2675 post_create_inferior (¤t_target, from_tty);
2680 /* Initialize static vars when a new inferior begins. */
2683 init_wait_for_inferior (void)
2685 /* These are meaningless until the first time through wait_for_inferior. */
2687 breakpoint_init_inferior (inf_starting);
2689 clear_proceed_status (0);
2691 target_last_wait_ptid = minus_one_ptid;
2693 previous_inferior_ptid = inferior_ptid;
2695 /* Discard any skipped inlined frames. */
2696 clear_inline_frame_state (minus_one_ptid);
2700 /* This enum encodes possible reasons for doing a target_wait, so that
2701 wfi can call target_wait in one place. (Ultimately the call will be
2702 moved out of the infinite loop entirely.) */
2706 infwait_normal_state,
2707 infwait_step_watch_state,
2708 infwait_nonstep_watch_state
2711 /* Current inferior wait state. */
2712 static enum infwait_states infwait_state;
2714 /* Data to be passed around while handling an event. This data is
2715 discarded between events. */
2716 struct execution_control_state
2719 /* The thread that got the event, if this was a thread event; NULL
2721 struct thread_info *event_thread;
2723 struct target_waitstatus ws;
2724 int stop_func_filled_in;
2725 CORE_ADDR stop_func_start;
2726 CORE_ADDR stop_func_end;
2727 const char *stop_func_name;
2730 /* True if the event thread hit the single-step breakpoint of
2731 another thread. Thus the event doesn't cause a stop, the thread
2732 needs to be single-stepped past the single-step breakpoint before
2733 we can switch back to the original stepping thread. */
2734 int hit_singlestep_breakpoint;
2737 static void handle_inferior_event (struct execution_control_state *ecs);
2739 static void handle_step_into_function (struct gdbarch *gdbarch,
2740 struct execution_control_state *ecs);
2741 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2742 struct execution_control_state *ecs);
2743 static void handle_signal_stop (struct execution_control_state *ecs);
2744 static void check_exception_resume (struct execution_control_state *,
2745 struct frame_info *);
2747 static void end_stepping_range (struct execution_control_state *ecs);
2748 static void stop_waiting (struct execution_control_state *ecs);
2749 static void prepare_to_wait (struct execution_control_state *ecs);
2750 static void keep_going (struct execution_control_state *ecs);
2751 static void process_event_stop_test (struct execution_control_state *ecs);
2752 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
2754 /* Callback for iterate over threads. If the thread is stopped, but
2755 the user/frontend doesn't know about that yet, go through
2756 normal_stop, as if the thread had just stopped now. ARG points at
2757 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2758 ptid_is_pid(PTID) is true, applies to all threads of the process
2759 pointed at by PTID. Otherwise, apply only to the thread pointed by
2763 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2765 ptid_t ptid = * (ptid_t *) arg;
2767 if ((ptid_equal (info->ptid, ptid)
2768 || ptid_equal (minus_one_ptid, ptid)
2769 || (ptid_is_pid (ptid)
2770 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2771 && is_running (info->ptid)
2772 && !is_executing (info->ptid))
2774 struct cleanup *old_chain;
2775 struct execution_control_state ecss;
2776 struct execution_control_state *ecs = &ecss;
2778 memset (ecs, 0, sizeof (*ecs));
2780 old_chain = make_cleanup_restore_current_thread ();
2782 overlay_cache_invalid = 1;
2783 /* Flush target cache before starting to handle each event.
2784 Target was running and cache could be stale. This is just a
2785 heuristic. Running threads may modify target memory, but we
2786 don't get any event. */
2787 target_dcache_invalidate ();
2789 /* Go through handle_inferior_event/normal_stop, so we always
2790 have consistent output as if the stop event had been
2792 ecs->ptid = info->ptid;
2793 ecs->event_thread = find_thread_ptid (info->ptid);
2794 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2795 ecs->ws.value.sig = GDB_SIGNAL_0;
2797 handle_inferior_event (ecs);
2799 if (!ecs->wait_some_more)
2801 struct thread_info *tp;
2805 /* Finish off the continuations. */
2806 tp = inferior_thread ();
2807 do_all_intermediate_continuations_thread (tp, 1);
2808 do_all_continuations_thread (tp, 1);
2811 do_cleanups (old_chain);
2817 /* This function is attached as a "thread_stop_requested" observer.
2818 Cleanup local state that assumed the PTID was to be resumed, and
2819 report the stop to the frontend. */
2822 infrun_thread_stop_requested (ptid_t ptid)
2824 struct displaced_step_inferior_state *displaced;
2826 /* PTID was requested to stop. Remove it from the displaced
2827 stepping queue, so we don't try to resume it automatically. */
2829 for (displaced = displaced_step_inferior_states;
2831 displaced = displaced->next)
2833 struct displaced_step_request *it, **prev_next_p;
2835 it = displaced->step_request_queue;
2836 prev_next_p = &displaced->step_request_queue;
2839 if (ptid_match (it->ptid, ptid))
2841 *prev_next_p = it->next;
2847 prev_next_p = &it->next;
2854 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2858 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2860 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2861 nullify_last_target_wait_ptid ();
2864 /* Delete the step resume, single-step and longjmp/exception resume
2865 breakpoints of TP. */
2868 delete_thread_infrun_breakpoints (struct thread_info *tp)
2870 delete_step_resume_breakpoint (tp);
2871 delete_exception_resume_breakpoint (tp);
2872 delete_single_step_breakpoints (tp);
2875 /* If the target still has execution, call FUNC for each thread that
2876 just stopped. In all-stop, that's all the non-exited threads; in
2877 non-stop, that's the current thread, only. */
2879 typedef void (*for_each_just_stopped_thread_callback_func)
2880 (struct thread_info *tp);
2883 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
2885 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
2890 /* If in non-stop mode, only the current thread stopped. */
2891 func (inferior_thread ());
2895 struct thread_info *tp;
2897 /* In all-stop mode, all threads have stopped. */
2898 ALL_NON_EXITED_THREADS (tp)
2905 /* Delete the step resume and longjmp/exception resume breakpoints of
2906 the threads that just stopped. */
2909 delete_just_stopped_threads_infrun_breakpoints (void)
2911 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
2914 /* Delete the single-step breakpoints of the threads that just
2918 delete_just_stopped_threads_single_step_breakpoints (void)
2920 for_each_just_stopped_thread (delete_single_step_breakpoints);
2923 /* A cleanup wrapper. */
2926 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
2928 delete_just_stopped_threads_infrun_breakpoints ();
2931 /* Pretty print the results of target_wait, for debugging purposes. */
2934 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2935 const struct target_waitstatus *ws)
2937 char *status_string = target_waitstatus_to_string (ws);
2938 struct ui_file *tmp_stream = mem_fileopen ();
2941 /* The text is split over several lines because it was getting too long.
2942 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2943 output as a unit; we want only one timestamp printed if debug_timestamp
2946 fprintf_unfiltered (tmp_stream,
2947 "infrun: target_wait (%d", ptid_get_pid (waiton_ptid));
2948 if (ptid_get_pid (waiton_ptid) != -1)
2949 fprintf_unfiltered (tmp_stream,
2950 " [%s]", target_pid_to_str (waiton_ptid));
2951 fprintf_unfiltered (tmp_stream, ", status) =\n");
2952 fprintf_unfiltered (tmp_stream,
2953 "infrun: %d [%s],\n",
2954 ptid_get_pid (result_ptid),
2955 target_pid_to_str (result_ptid));
2956 fprintf_unfiltered (tmp_stream,
2960 text = ui_file_xstrdup (tmp_stream, NULL);
2962 /* This uses %s in part to handle %'s in the text, but also to avoid
2963 a gcc error: the format attribute requires a string literal. */
2964 fprintf_unfiltered (gdb_stdlog, "%s", text);
2966 xfree (status_string);
2968 ui_file_delete (tmp_stream);
2971 /* Prepare and stabilize the inferior for detaching it. E.g.,
2972 detaching while a thread is displaced stepping is a recipe for
2973 crashing it, as nothing would readjust the PC out of the scratch
2977 prepare_for_detach (void)
2979 struct inferior *inf = current_inferior ();
2980 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2981 struct cleanup *old_chain_1;
2982 struct displaced_step_inferior_state *displaced;
2984 displaced = get_displaced_stepping_state (inf->pid);
2986 /* Is any thread of this process displaced stepping? If not,
2987 there's nothing else to do. */
2988 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2992 fprintf_unfiltered (gdb_stdlog,
2993 "displaced-stepping in-process while detaching");
2995 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2998 while (!ptid_equal (displaced->step_ptid, null_ptid))
3000 struct cleanup *old_chain_2;
3001 struct execution_control_state ecss;
3002 struct execution_control_state *ecs;
3005 memset (ecs, 0, sizeof (*ecs));
3007 overlay_cache_invalid = 1;
3008 /* Flush target cache before starting to handle each event.
3009 Target was running and cache could be stale. This is just a
3010 heuristic. Running threads may modify target memory, but we
3011 don't get any event. */
3012 target_dcache_invalidate ();
3014 if (deprecated_target_wait_hook)
3015 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
3017 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
3020 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3022 /* If an error happens while handling the event, propagate GDB's
3023 knowledge of the executing state to the frontend/user running
3025 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3028 /* Now figure out what to do with the result of the result. */
3029 handle_inferior_event (ecs);
3031 /* No error, don't finish the state yet. */
3032 discard_cleanups (old_chain_2);
3034 /* Breakpoints and watchpoints are not installed on the target
3035 at this point, and signals are passed directly to the
3036 inferior, so this must mean the process is gone. */
3037 if (!ecs->wait_some_more)
3039 discard_cleanups (old_chain_1);
3040 error (_("Program exited while detaching"));
3044 discard_cleanups (old_chain_1);
3047 /* Wait for control to return from inferior to debugger.
3049 If inferior gets a signal, we may decide to start it up again
3050 instead of returning. That is why there is a loop in this function.
3051 When this function actually returns it means the inferior
3052 should be left stopped and GDB should read more commands. */
3055 wait_for_inferior (void)
3057 struct cleanup *old_cleanups;
3061 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3064 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3069 struct execution_control_state ecss;
3070 struct execution_control_state *ecs = &ecss;
3071 struct cleanup *old_chain;
3072 ptid_t waiton_ptid = minus_one_ptid;
3074 memset (ecs, 0, sizeof (*ecs));
3076 overlay_cache_invalid = 1;
3078 /* Flush target cache before starting to handle each event.
3079 Target was running and cache could be stale. This is just a
3080 heuristic. Running threads may modify target memory, but we
3081 don't get any event. */
3082 target_dcache_invalidate ();
3084 if (deprecated_target_wait_hook)
3085 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
3087 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
3090 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3092 /* If an error happens while handling the event, propagate GDB's
3093 knowledge of the executing state to the frontend/user running
3095 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3097 /* Now figure out what to do with the result of the result. */
3098 handle_inferior_event (ecs);
3100 /* No error, don't finish the state yet. */
3101 discard_cleanups (old_chain);
3103 if (!ecs->wait_some_more)
3107 do_cleanups (old_cleanups);
3110 /* Cleanup that reinstalls the readline callback handler, if the
3111 target is running in the background. If while handling the target
3112 event something triggered a secondary prompt, like e.g., a
3113 pagination prompt, we'll have removed the callback handler (see
3114 gdb_readline_wrapper_line). Need to do this as we go back to the
3115 event loop, ready to process further input. Note this has no
3116 effect if the handler hasn't actually been removed, because calling
3117 rl_callback_handler_install resets the line buffer, thus losing
3121 reinstall_readline_callback_handler_cleanup (void *arg)
3123 if (async_command_editing_p && !sync_execution)
3124 gdb_rl_callback_handler_reinstall ();
3127 /* Asynchronous version of wait_for_inferior. It is called by the
3128 event loop whenever a change of state is detected on the file
3129 descriptor corresponding to the target. It can be called more than
3130 once to complete a single execution command. In such cases we need
3131 to keep the state in a global variable ECSS. If it is the last time
3132 that this function is called for a single execution command, then
3133 report to the user that the inferior has stopped, and do the
3134 necessary cleanups. */
3137 fetch_inferior_event (void *client_data)
3139 struct execution_control_state ecss;
3140 struct execution_control_state *ecs = &ecss;
3141 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3142 struct cleanup *ts_old_chain;
3143 int was_sync = sync_execution;
3145 ptid_t waiton_ptid = minus_one_ptid;
3147 memset (ecs, 0, sizeof (*ecs));
3149 /* End up with readline processing input, if necessary. */
3150 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3152 /* We're handling a live event, so make sure we're doing live
3153 debugging. If we're looking at traceframes while the target is
3154 running, we're going to need to get back to that mode after
3155 handling the event. */
3158 make_cleanup_restore_current_traceframe ();
3159 set_current_traceframe (-1);
3163 /* In non-stop mode, the user/frontend should not notice a thread
3164 switch due to internal events. Make sure we reverse to the
3165 user selected thread and frame after handling the event and
3166 running any breakpoint commands. */
3167 make_cleanup_restore_current_thread ();
3169 overlay_cache_invalid = 1;
3170 /* Flush target cache before starting to handle each event. Target
3171 was running and cache could be stale. This is just a heuristic.
3172 Running threads may modify target memory, but we don't get any
3174 target_dcache_invalidate ();
3176 make_cleanup_restore_integer (&execution_direction);
3177 execution_direction = target_execution_direction ();
3179 if (deprecated_target_wait_hook)
3181 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3183 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3186 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3188 /* If an error happens while handling the event, propagate GDB's
3189 knowledge of the executing state to the frontend/user running
3192 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3194 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3196 /* Get executed before make_cleanup_restore_current_thread above to apply
3197 still for the thread which has thrown the exception. */
3198 make_bpstat_clear_actions_cleanup ();
3200 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3202 /* Now figure out what to do with the result of the result. */
3203 handle_inferior_event (ecs);
3205 if (!ecs->wait_some_more)
3207 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
3209 delete_just_stopped_threads_infrun_breakpoints ();
3211 /* We may not find an inferior if this was a process exit. */
3212 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3215 if (target_has_execution
3216 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
3217 && ecs->ws.kind != TARGET_WAITKIND_EXITED
3218 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3219 && ecs->event_thread->step_multi
3220 && ecs->event_thread->control.stop_step)
3221 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
3224 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3229 /* No error, don't finish the thread states yet. */
3230 discard_cleanups (ts_old_chain);
3232 /* Revert thread and frame. */
3233 do_cleanups (old_chain);
3235 /* If the inferior was in sync execution mode, and now isn't,
3236 restore the prompt (a synchronous execution command has finished,
3237 and we're ready for input). */
3238 if (interpreter_async && was_sync && !sync_execution)
3239 observer_notify_sync_execution_done ();
3243 && exec_done_display_p
3244 && (ptid_equal (inferior_ptid, null_ptid)
3245 || !is_running (inferior_ptid)))
3246 printf_unfiltered (_("completed.\n"));
3249 /* Record the frame and location we're currently stepping through. */
3251 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3253 struct thread_info *tp = inferior_thread ();
3255 tp->control.step_frame_id = get_frame_id (frame);
3256 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3258 tp->current_symtab = sal.symtab;
3259 tp->current_line = sal.line;
3262 /* Clear context switchable stepping state. */
3265 init_thread_stepping_state (struct thread_info *tss)
3267 tss->stepped_breakpoint = 0;
3268 tss->stepping_over_breakpoint = 0;
3269 tss->stepping_over_watchpoint = 0;
3270 tss->step_after_step_resume_breakpoint = 0;
3273 /* Set the cached copy of the last ptid/waitstatus. */
3276 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3278 target_last_wait_ptid = ptid;
3279 target_last_waitstatus = status;
3282 /* Return the cached copy of the last pid/waitstatus returned by
3283 target_wait()/deprecated_target_wait_hook(). The data is actually
3284 cached by handle_inferior_event(), which gets called immediately
3285 after target_wait()/deprecated_target_wait_hook(). */
3288 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3290 *ptidp = target_last_wait_ptid;
3291 *status = target_last_waitstatus;
3295 nullify_last_target_wait_ptid (void)
3297 target_last_wait_ptid = minus_one_ptid;
3300 /* Switch thread contexts. */
3303 context_switch (ptid_t ptid)
3305 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
3307 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3308 target_pid_to_str (inferior_ptid));
3309 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3310 target_pid_to_str (ptid));
3313 switch_to_thread (ptid);
3317 adjust_pc_after_break (struct execution_control_state *ecs)
3319 struct regcache *regcache;
3320 struct gdbarch *gdbarch;
3321 struct address_space *aspace;
3322 CORE_ADDR breakpoint_pc, decr_pc;
3324 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3325 we aren't, just return.
3327 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3328 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3329 implemented by software breakpoints should be handled through the normal
3332 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3333 different signals (SIGILL or SIGEMT for instance), but it is less
3334 clear where the PC is pointing afterwards. It may not match
3335 gdbarch_decr_pc_after_break. I don't know any specific target that
3336 generates these signals at breakpoints (the code has been in GDB since at
3337 least 1992) so I can not guess how to handle them here.
3339 In earlier versions of GDB, a target with
3340 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3341 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3342 target with both of these set in GDB history, and it seems unlikely to be
3343 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3345 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
3348 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
3351 /* In reverse execution, when a breakpoint is hit, the instruction
3352 under it has already been de-executed. The reported PC always
3353 points at the breakpoint address, so adjusting it further would
3354 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3357 B1 0x08000000 : INSN1
3358 B2 0x08000001 : INSN2
3360 PC -> 0x08000003 : INSN4
3362 Say you're stopped at 0x08000003 as above. Reverse continuing
3363 from that point should hit B2 as below. Reading the PC when the
3364 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3365 been de-executed already.
3367 B1 0x08000000 : INSN1
3368 B2 PC -> 0x08000001 : INSN2
3372 We can't apply the same logic as for forward execution, because
3373 we would wrongly adjust the PC to 0x08000000, since there's a
3374 breakpoint at PC - 1. We'd then report a hit on B1, although
3375 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3377 if (execution_direction == EXEC_REVERSE)
3380 /* If this target does not decrement the PC after breakpoints, then
3381 we have nothing to do. */
3382 regcache = get_thread_regcache (ecs->ptid);
3383 gdbarch = get_regcache_arch (regcache);
3385 decr_pc = target_decr_pc_after_break (gdbarch);
3389 aspace = get_regcache_aspace (regcache);
3391 /* Find the location where (if we've hit a breakpoint) the
3392 breakpoint would be. */
3393 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3395 /* Check whether there actually is a software breakpoint inserted at
3398 If in non-stop mode, a race condition is possible where we've
3399 removed a breakpoint, but stop events for that breakpoint were
3400 already queued and arrive later. To suppress those spurious
3401 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3402 and retire them after a number of stop events are reported. */
3403 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3404 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3406 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
3408 if (record_full_is_used ())
3409 record_full_gdb_operation_disable_set ();
3411 /* When using hardware single-step, a SIGTRAP is reported for both
3412 a completed single-step and a software breakpoint. Need to
3413 differentiate between the two, as the latter needs adjusting
3414 but the former does not.
3416 The SIGTRAP can be due to a completed hardware single-step only if
3417 - we didn't insert software single-step breakpoints
3418 - the thread to be examined is still the current thread
3419 - this thread is currently being stepped
3421 If any of these events did not occur, we must have stopped due
3422 to hitting a software breakpoint, and have to back up to the
3425 As a special case, we could have hardware single-stepped a
3426 software breakpoint. In this case (prev_pc == breakpoint_pc),
3427 we also need to back up to the breakpoint address. */
3429 if (thread_has_single_step_breakpoints_set (ecs->event_thread)
3430 || !ptid_equal (ecs->ptid, inferior_ptid)
3431 || !currently_stepping (ecs->event_thread)
3432 || (ecs->event_thread->stepped_breakpoint
3433 && ecs->event_thread->prev_pc == breakpoint_pc))
3434 regcache_write_pc (regcache, breakpoint_pc);
3436 do_cleanups (old_cleanups);
3441 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3443 for (frame = get_prev_frame (frame);
3445 frame = get_prev_frame (frame))
3447 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3449 if (get_frame_type (frame) != INLINE_FRAME)
3456 /* Auxiliary function that handles syscall entry/return events.
3457 It returns 1 if the inferior should keep going (and GDB
3458 should ignore the event), or 0 if the event deserves to be
3462 handle_syscall_event (struct execution_control_state *ecs)
3464 struct regcache *regcache;
3467 if (!ptid_equal (ecs->ptid, inferior_ptid))
3468 context_switch (ecs->ptid);
3470 regcache = get_thread_regcache (ecs->ptid);
3471 syscall_number = ecs->ws.value.syscall_number;
3472 stop_pc = regcache_read_pc (regcache);
3474 if (catch_syscall_enabled () > 0
3475 && catching_syscall_number (syscall_number) > 0)
3478 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3481 ecs->event_thread->control.stop_bpstat
3482 = bpstat_stop_status (get_regcache_aspace (regcache),
3483 stop_pc, ecs->ptid, &ecs->ws);
3485 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3487 /* Catchpoint hit. */
3492 /* If no catchpoint triggered for this, then keep going. */
3497 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3500 fill_in_stop_func (struct gdbarch *gdbarch,
3501 struct execution_control_state *ecs)
3503 if (!ecs->stop_func_filled_in)
3505 /* Don't care about return value; stop_func_start and stop_func_name
3506 will both be 0 if it doesn't work. */
3507 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3508 &ecs->stop_func_start, &ecs->stop_func_end);
3509 ecs->stop_func_start
3510 += gdbarch_deprecated_function_start_offset (gdbarch);
3512 if (gdbarch_skip_entrypoint_p (gdbarch))
3513 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
3514 ecs->stop_func_start);
3516 ecs->stop_func_filled_in = 1;
3521 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
3523 static enum stop_kind
3524 get_inferior_stop_soon (ptid_t ptid)
3526 struct inferior *inf = find_inferior_pid (ptid_get_pid (ptid));
3528 gdb_assert (inf != NULL);
3529 return inf->control.stop_soon;
3532 /* Given an execution control state that has been freshly filled in by
3533 an event from the inferior, figure out what it means and take
3536 The alternatives are:
3538 1) stop_waiting and return; to really stop and return to the
3541 2) keep_going and return; to wait for the next event (set
3542 ecs->event_thread->stepping_over_breakpoint to 1 to single step
3546 handle_inferior_event (struct execution_control_state *ecs)
3548 enum stop_kind stop_soon;
3550 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3552 /* We had an event in the inferior, but we are not interested in
3553 handling it at this level. The lower layers have already
3554 done what needs to be done, if anything.
3556 One of the possible circumstances for this is when the
3557 inferior produces output for the console. The inferior has
3558 not stopped, and we are ignoring the event. Another possible
3559 circumstance is any event which the lower level knows will be
3560 reported multiple times without an intervening resume. */
3562 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3563 prepare_to_wait (ecs);
3567 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3568 && target_can_async_p () && !sync_execution)
3570 /* There were no unwaited-for children left in the target, but,
3571 we're not synchronously waiting for events either. Just
3572 ignore. Otherwise, if we were running a synchronous
3573 execution command, we need to cancel it and give the user
3574 back the terminal. */
3576 fprintf_unfiltered (gdb_stdlog,
3577 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3578 prepare_to_wait (ecs);
3582 /* Cache the last pid/waitstatus. */
3583 set_last_target_status (ecs->ptid, ecs->ws);
3585 /* Always clear state belonging to the previous time we stopped. */
3586 stop_stack_dummy = STOP_NONE;
3588 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3590 /* No unwaited-for children left. IOW, all resumed children
3593 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3595 stop_print_frame = 0;
3600 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3601 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3603 ecs->event_thread = find_thread_ptid (ecs->ptid);
3604 /* If it's a new thread, add it to the thread database. */
3605 if (ecs->event_thread == NULL)
3606 ecs->event_thread = add_thread (ecs->ptid);
3608 /* Disable range stepping. If the next step request could use a
3609 range, this will be end up re-enabled then. */
3610 ecs->event_thread->control.may_range_step = 0;
3613 /* Dependent on valid ECS->EVENT_THREAD. */
3614 adjust_pc_after_break (ecs);
3616 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3617 reinit_frame_cache ();
3619 breakpoint_retire_moribund ();
3621 /* First, distinguish signals caused by the debugger from signals
3622 that have to do with the program's own actions. Note that
3623 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3624 on the operating system version. Here we detect when a SIGILL or
3625 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3626 something similar for SIGSEGV, since a SIGSEGV will be generated
3627 when we're trying to execute a breakpoint instruction on a
3628 non-executable stack. This happens for call dummy breakpoints
3629 for architectures like SPARC that place call dummies on the
3631 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3632 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3633 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3634 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3636 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3638 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3639 regcache_read_pc (regcache)))
3642 fprintf_unfiltered (gdb_stdlog,
3643 "infrun: Treating signal as SIGTRAP\n");
3644 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3648 /* Mark the non-executing threads accordingly. In all-stop, all
3649 threads of all processes are stopped when we get any event
3650 reported. In non-stop mode, only the event thread stops. If
3651 we're handling a process exit in non-stop mode, there's nothing
3652 to do, as threads of the dead process are gone, and threads of
3653 any other process were left running. */
3655 set_executing (minus_one_ptid, 0);
3656 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3657 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3658 set_executing (ecs->ptid, 0);
3660 switch (ecs->ws.kind)
3662 case TARGET_WAITKIND_LOADED:
3664 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3665 if (!ptid_equal (ecs->ptid, inferior_ptid))
3666 context_switch (ecs->ptid);
3667 /* Ignore gracefully during startup of the inferior, as it might
3668 be the shell which has just loaded some objects, otherwise
3669 add the symbols for the newly loaded objects. Also ignore at
3670 the beginning of an attach or remote session; we will query
3671 the full list of libraries once the connection is
3674 stop_soon = get_inferior_stop_soon (ecs->ptid);
3675 if (stop_soon == NO_STOP_QUIETLY)
3677 struct regcache *regcache;
3679 regcache = get_thread_regcache (ecs->ptid);
3681 handle_solib_event ();
3683 ecs->event_thread->control.stop_bpstat
3684 = bpstat_stop_status (get_regcache_aspace (regcache),
3685 stop_pc, ecs->ptid, &ecs->ws);
3687 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3689 /* A catchpoint triggered. */
3690 process_event_stop_test (ecs);
3694 /* If requested, stop when the dynamic linker notifies
3695 gdb of events. This allows the user to get control
3696 and place breakpoints in initializer routines for
3697 dynamically loaded objects (among other things). */
3698 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3699 if (stop_on_solib_events)
3701 /* Make sure we print "Stopped due to solib-event" in
3703 stop_print_frame = 1;
3710 /* If we are skipping through a shell, or through shared library
3711 loading that we aren't interested in, resume the program. If
3712 we're running the program normally, also resume. */
3713 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3715 /* Loading of shared libraries might have changed breakpoint
3716 addresses. Make sure new breakpoints are inserted. */
3717 if (stop_soon == NO_STOP_QUIETLY)
3718 insert_breakpoints ();
3719 resume (0, GDB_SIGNAL_0);
3720 prepare_to_wait (ecs);
3724 /* But stop if we're attaching or setting up a remote
3726 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
3727 || stop_soon == STOP_QUIETLY_REMOTE)
3730 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
3735 internal_error (__FILE__, __LINE__,
3736 _("unhandled stop_soon: %d"), (int) stop_soon);
3738 case TARGET_WAITKIND_SPURIOUS:
3740 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3741 if (!ptid_equal (ecs->ptid, inferior_ptid))
3742 context_switch (ecs->ptid);
3743 resume (0, GDB_SIGNAL_0);
3744 prepare_to_wait (ecs);
3747 case TARGET_WAITKIND_EXITED:
3748 case TARGET_WAITKIND_SIGNALLED:
3751 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3752 fprintf_unfiltered (gdb_stdlog,
3753 "infrun: TARGET_WAITKIND_EXITED\n");
3755 fprintf_unfiltered (gdb_stdlog,
3756 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3759 inferior_ptid = ecs->ptid;
3760 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3761 set_current_program_space (current_inferior ()->pspace);
3762 handle_vfork_child_exec_or_exit (0);
3763 target_terminal_ours (); /* Must do this before mourn anyway. */
3765 /* Clearing any previous state of convenience variables. */
3766 clear_exit_convenience_vars ();
3768 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3770 /* Record the exit code in the convenience variable $_exitcode, so
3771 that the user can inspect this again later. */
3772 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3773 (LONGEST) ecs->ws.value.integer);
3775 /* Also record this in the inferior itself. */
3776 current_inferior ()->has_exit_code = 1;
3777 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3779 /* Support the --return-child-result option. */
3780 return_child_result_value = ecs->ws.value.integer;
3782 observer_notify_exited (ecs->ws.value.integer);
3786 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3787 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3789 if (gdbarch_gdb_signal_to_target_p (gdbarch))
3791 /* Set the value of the internal variable $_exitsignal,
3792 which holds the signal uncaught by the inferior. */
3793 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
3794 gdbarch_gdb_signal_to_target (gdbarch,
3795 ecs->ws.value.sig));
3799 /* We don't have access to the target's method used for
3800 converting between signal numbers (GDB's internal
3801 representation <-> target's representation).
3802 Therefore, we cannot do a good job at displaying this
3803 information to the user. It's better to just warn
3804 her about it (if infrun debugging is enabled), and
3807 fprintf_filtered (gdb_stdlog, _("\
3808 Cannot fill $_exitsignal with the correct signal number.\n"));
3811 observer_notify_signal_exited (ecs->ws.value.sig);
3814 gdb_flush (gdb_stdout);
3815 target_mourn_inferior ();
3816 stop_print_frame = 0;
3820 /* The following are the only cases in which we keep going;
3821 the above cases end in a continue or goto. */
3822 case TARGET_WAITKIND_FORKED:
3823 case TARGET_WAITKIND_VFORKED:
3826 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3827 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3829 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3832 /* Check whether the inferior is displaced stepping. */
3834 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3835 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3836 struct displaced_step_inferior_state *displaced
3837 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3839 /* If checking displaced stepping is supported, and thread
3840 ecs->ptid is displaced stepping. */
3841 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3843 struct inferior *parent_inf
3844 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3845 struct regcache *child_regcache;
3846 CORE_ADDR parent_pc;
3848 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3849 indicating that the displaced stepping of syscall instruction
3850 has been done. Perform cleanup for parent process here. Note
3851 that this operation also cleans up the child process for vfork,
3852 because their pages are shared. */
3853 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3855 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3857 /* Restore scratch pad for child process. */
3858 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3861 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3862 the child's PC is also within the scratchpad. Set the child's PC
3863 to the parent's PC value, which has already been fixed up.
3864 FIXME: we use the parent's aspace here, although we're touching
3865 the child, because the child hasn't been added to the inferior
3866 list yet at this point. */
3869 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3871 parent_inf->aspace);
3872 /* Read PC value of parent process. */
3873 parent_pc = regcache_read_pc (regcache);
3875 if (debug_displaced)
3876 fprintf_unfiltered (gdb_stdlog,
3877 "displaced: write child pc from %s to %s\n",
3879 regcache_read_pc (child_regcache)),
3880 paddress (gdbarch, parent_pc));
3882 regcache_write_pc (child_regcache, parent_pc);
3886 if (!ptid_equal (ecs->ptid, inferior_ptid))
3887 context_switch (ecs->ptid);
3889 /* Immediately detach breakpoints from the child before there's
3890 any chance of letting the user delete breakpoints from the
3891 breakpoint lists. If we don't do this early, it's easy to
3892 leave left over traps in the child, vis: "break foo; catch
3893 fork; c; <fork>; del; c; <child calls foo>". We only follow
3894 the fork on the last `continue', and by that time the
3895 breakpoint at "foo" is long gone from the breakpoint table.
3896 If we vforked, then we don't need to unpatch here, since both
3897 parent and child are sharing the same memory pages; we'll
3898 need to unpatch at follow/detach time instead to be certain
3899 that new breakpoints added between catchpoint hit time and
3900 vfork follow are detached. */
3901 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3903 /* This won't actually modify the breakpoint list, but will
3904 physically remove the breakpoints from the child. */
3905 detach_breakpoints (ecs->ws.value.related_pid);
3908 delete_just_stopped_threads_single_step_breakpoints ();
3910 /* In case the event is caught by a catchpoint, remember that
3911 the event is to be followed at the next resume of the thread,
3912 and not immediately. */
3913 ecs->event_thread->pending_follow = ecs->ws;
3915 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3917 ecs->event_thread->control.stop_bpstat
3918 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3919 stop_pc, ecs->ptid, &ecs->ws);
3921 /* If no catchpoint triggered for this, then keep going. Note
3922 that we're interested in knowing the bpstat actually causes a
3923 stop, not just if it may explain the signal. Software
3924 watchpoints, for example, always appear in the bpstat. */
3925 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3931 = (follow_fork_mode_string == follow_fork_mode_child);
3933 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3935 should_resume = follow_fork ();
3938 child = ecs->ws.value.related_pid;
3940 /* In non-stop mode, also resume the other branch. */
3941 if (non_stop && !detach_fork)
3944 switch_to_thread (parent);
3946 switch_to_thread (child);
3948 ecs->event_thread = inferior_thread ();
3949 ecs->ptid = inferior_ptid;
3954 switch_to_thread (child);
3956 switch_to_thread (parent);
3958 ecs->event_thread = inferior_thread ();
3959 ecs->ptid = inferior_ptid;
3967 process_event_stop_test (ecs);
3970 case TARGET_WAITKIND_VFORK_DONE:
3971 /* Done with the shared memory region. Re-insert breakpoints in
3972 the parent, and keep going. */
3975 fprintf_unfiltered (gdb_stdlog,
3976 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3978 if (!ptid_equal (ecs->ptid, inferior_ptid))
3979 context_switch (ecs->ptid);
3981 current_inferior ()->waiting_for_vfork_done = 0;
3982 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3983 /* This also takes care of reinserting breakpoints in the
3984 previously locked inferior. */
3988 case TARGET_WAITKIND_EXECD:
3990 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3992 if (!ptid_equal (ecs->ptid, inferior_ptid))
3993 context_switch (ecs->ptid);
3995 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3997 /* Do whatever is necessary to the parent branch of the vfork. */
3998 handle_vfork_child_exec_or_exit (1);
4000 /* This causes the eventpoints and symbol table to be reset.
4001 Must do this now, before trying to determine whether to
4003 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
4005 ecs->event_thread->control.stop_bpstat
4006 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4007 stop_pc, ecs->ptid, &ecs->ws);
4009 /* Note that this may be referenced from inside
4010 bpstat_stop_status above, through inferior_has_execd. */
4011 xfree (ecs->ws.value.execd_pathname);
4012 ecs->ws.value.execd_pathname = NULL;
4014 /* If no catchpoint triggered for this, then keep going. */
4015 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4017 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4021 process_event_stop_test (ecs);
4024 /* Be careful not to try to gather much state about a thread
4025 that's in a syscall. It's frequently a losing proposition. */
4026 case TARGET_WAITKIND_SYSCALL_ENTRY:
4028 fprintf_unfiltered (gdb_stdlog,
4029 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
4030 /* Getting the current syscall number. */
4031 if (handle_syscall_event (ecs) == 0)
4032 process_event_stop_test (ecs);
4035 /* Before examining the threads further, step this thread to
4036 get it entirely out of the syscall. (We get notice of the
4037 event when the thread is just on the verge of exiting a
4038 syscall. Stepping one instruction seems to get it back
4040 case TARGET_WAITKIND_SYSCALL_RETURN:
4042 fprintf_unfiltered (gdb_stdlog,
4043 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
4044 if (handle_syscall_event (ecs) == 0)
4045 process_event_stop_test (ecs);
4048 case TARGET_WAITKIND_STOPPED:
4050 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
4051 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
4052 handle_signal_stop (ecs);
4055 case TARGET_WAITKIND_NO_HISTORY:
4057 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
4058 /* Reverse execution: target ran out of history info. */
4060 delete_just_stopped_threads_single_step_breakpoints ();
4061 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4062 observer_notify_no_history ();
4068 /* Come here when the program has stopped with a signal. */
4071 handle_signal_stop (struct execution_control_state *ecs)
4073 struct frame_info *frame;
4074 struct gdbarch *gdbarch;
4075 int stopped_by_watchpoint;
4076 enum stop_kind stop_soon;
4079 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
4081 /* Do we need to clean up the state of a thread that has
4082 completed a displaced single-step? (Doing so usually affects
4083 the PC, so do it here, before we set stop_pc.) */
4084 displaced_step_fixup (ecs->ptid,
4085 ecs->event_thread->suspend.stop_signal);
4087 /* If we either finished a single-step or hit a breakpoint, but
4088 the user wanted this thread to be stopped, pretend we got a
4089 SIG0 (generic unsignaled stop). */
4090 if (ecs->event_thread->stop_requested
4091 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4092 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4094 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4098 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4099 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4100 struct cleanup *old_chain = save_inferior_ptid ();
4102 inferior_ptid = ecs->ptid;
4104 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
4105 paddress (gdbarch, stop_pc));
4106 if (target_stopped_by_watchpoint ())
4110 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
4112 if (target_stopped_data_address (¤t_target, &addr))
4113 fprintf_unfiltered (gdb_stdlog,
4114 "infrun: stopped data address = %s\n",
4115 paddress (gdbarch, addr));
4117 fprintf_unfiltered (gdb_stdlog,
4118 "infrun: (no data address available)\n");
4121 do_cleanups (old_chain);
4124 /* This is originated from start_remote(), start_inferior() and
4125 shared libraries hook functions. */
4126 stop_soon = get_inferior_stop_soon (ecs->ptid);
4127 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4129 if (!ptid_equal (ecs->ptid, inferior_ptid))
4130 context_switch (ecs->ptid);
4132 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4133 stop_print_frame = 1;
4138 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4141 if (!ptid_equal (ecs->ptid, inferior_ptid))
4142 context_switch (ecs->ptid);
4144 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4145 stop_print_frame = 0;
4150 /* This originates from attach_command(). We need to overwrite
4151 the stop_signal here, because some kernels don't ignore a
4152 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4153 See more comments in inferior.h. On the other hand, if we
4154 get a non-SIGSTOP, report it to the user - assume the backend
4155 will handle the SIGSTOP if it should show up later.
4157 Also consider that the attach is complete when we see a
4158 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4159 target extended-remote report it instead of a SIGSTOP
4160 (e.g. gdbserver). We already rely on SIGTRAP being our
4161 signal, so this is no exception.
4163 Also consider that the attach is complete when we see a
4164 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4165 the target to stop all threads of the inferior, in case the
4166 low level attach operation doesn't stop them implicitly. If
4167 they weren't stopped implicitly, then the stub will report a
4168 GDB_SIGNAL_0, meaning: stopped for no particular reason
4169 other than GDB's request. */
4170 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4171 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4172 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4173 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4175 stop_print_frame = 1;
4177 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4181 /* See if something interesting happened to the non-current thread. If
4182 so, then switch to that thread. */
4183 if (!ptid_equal (ecs->ptid, inferior_ptid))
4186 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
4188 context_switch (ecs->ptid);
4190 if (deprecated_context_hook)
4191 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
4194 /* At this point, get hold of the now-current thread's frame. */
4195 frame = get_current_frame ();
4196 gdbarch = get_frame_arch (frame);
4198 /* Pull the single step breakpoints out of the target. */
4199 if (gdbarch_software_single_step_p (gdbarch))
4201 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4203 struct regcache *regcache;
4204 struct address_space *aspace;
4207 regcache = get_thread_regcache (ecs->ptid);
4208 aspace = get_regcache_aspace (regcache);
4209 pc = regcache_read_pc (regcache);
4211 /* However, before doing so, if this single-step breakpoint was
4212 actually for another thread, set this thread up for moving
4214 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
4217 if (single_step_breakpoint_inserted_here_p (aspace, pc))
4221 fprintf_unfiltered (gdb_stdlog,
4222 "infrun: [%s] hit another thread's "
4223 "single-step breakpoint\n",
4224 target_pid_to_str (ecs->ptid));
4226 ecs->hit_singlestep_breakpoint = 1;
4233 fprintf_unfiltered (gdb_stdlog,
4234 "infrun: [%s] hit its "
4235 "single-step breakpoint\n",
4236 target_pid_to_str (ecs->ptid));
4241 delete_just_stopped_threads_single_step_breakpoints ();
4244 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4245 && ecs->event_thread->control.trap_expected
4246 && ecs->event_thread->stepping_over_watchpoint)
4247 stopped_by_watchpoint = 0;
4249 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4251 /* If necessary, step over this watchpoint. We'll be back to display
4253 if (stopped_by_watchpoint
4254 && (target_have_steppable_watchpoint
4255 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4257 /* At this point, we are stopped at an instruction which has
4258 attempted to write to a piece of memory under control of
4259 a watchpoint. The instruction hasn't actually executed
4260 yet. If we were to evaluate the watchpoint expression
4261 now, we would get the old value, and therefore no change
4262 would seem to have occurred.
4264 In order to make watchpoints work `right', we really need
4265 to complete the memory write, and then evaluate the
4266 watchpoint expression. We do this by single-stepping the
4269 It may not be necessary to disable the watchpoint to step over
4270 it. For example, the PA can (with some kernel cooperation)
4271 single step over a watchpoint without disabling the watchpoint.
4273 It is far more common to need to disable a watchpoint to step
4274 the inferior over it. If we have non-steppable watchpoints,
4275 we must disable the current watchpoint; it's simplest to
4276 disable all watchpoints.
4278 Any breakpoint at PC must also be stepped over -- if there's
4279 one, it will have already triggered before the watchpoint
4280 triggered, and we either already reported it to the user, or
4281 it didn't cause a stop and we called keep_going. In either
4282 case, if there was a breakpoint at PC, we must be trying to
4284 ecs->event_thread->stepping_over_watchpoint = 1;
4289 ecs->event_thread->stepped_breakpoint = 0;
4290 ecs->event_thread->stepping_over_breakpoint = 0;
4291 ecs->event_thread->stepping_over_watchpoint = 0;
4292 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4293 ecs->event_thread->control.stop_step = 0;
4294 stop_print_frame = 1;
4295 stopped_by_random_signal = 0;
4297 /* Hide inlined functions starting here, unless we just performed stepi or
4298 nexti. After stepi and nexti, always show the innermost frame (not any
4299 inline function call sites). */
4300 if (ecs->event_thread->control.step_range_end != 1)
4302 struct address_space *aspace =
4303 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4305 /* skip_inline_frames is expensive, so we avoid it if we can
4306 determine that the address is one where functions cannot have
4307 been inlined. This improves performance with inferiors that
4308 load a lot of shared libraries, because the solib event
4309 breakpoint is defined as the address of a function (i.e. not
4310 inline). Note that we have to check the previous PC as well
4311 as the current one to catch cases when we have just
4312 single-stepped off a breakpoint prior to reinstating it.
4313 Note that we're assuming that the code we single-step to is
4314 not inline, but that's not definitive: there's nothing
4315 preventing the event breakpoint function from containing
4316 inlined code, and the single-step ending up there. If the
4317 user had set a breakpoint on that inlined code, the missing
4318 skip_inline_frames call would break things. Fortunately
4319 that's an extremely unlikely scenario. */
4320 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4321 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4322 && ecs->event_thread->control.trap_expected
4323 && pc_at_non_inline_function (aspace,
4324 ecs->event_thread->prev_pc,
4327 skip_inline_frames (ecs->ptid);
4329 /* Re-fetch current thread's frame in case that invalidated
4331 frame = get_current_frame ();
4332 gdbarch = get_frame_arch (frame);
4336 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4337 && ecs->event_thread->control.trap_expected
4338 && gdbarch_single_step_through_delay_p (gdbarch)
4339 && currently_stepping (ecs->event_thread))
4341 /* We're trying to step off a breakpoint. Turns out that we're
4342 also on an instruction that needs to be stepped multiple
4343 times before it's been fully executing. E.g., architectures
4344 with a delay slot. It needs to be stepped twice, once for
4345 the instruction and once for the delay slot. */
4346 int step_through_delay
4347 = gdbarch_single_step_through_delay (gdbarch, frame);
4349 if (debug_infrun && step_through_delay)
4350 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4351 if (ecs->event_thread->control.step_range_end == 0
4352 && step_through_delay)
4354 /* The user issued a continue when stopped at a breakpoint.
4355 Set up for another trap and get out of here. */
4356 ecs->event_thread->stepping_over_breakpoint = 1;
4360 else if (step_through_delay)
4362 /* The user issued a step when stopped at a breakpoint.
4363 Maybe we should stop, maybe we should not - the delay
4364 slot *might* correspond to a line of source. In any
4365 case, don't decide that here, just set
4366 ecs->stepping_over_breakpoint, making sure we
4367 single-step again before breakpoints are re-inserted. */
4368 ecs->event_thread->stepping_over_breakpoint = 1;
4372 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4373 handles this event. */
4374 ecs->event_thread->control.stop_bpstat
4375 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4376 stop_pc, ecs->ptid, &ecs->ws);
4378 /* Following in case break condition called a
4380 stop_print_frame = 1;
4382 /* This is where we handle "moribund" watchpoints. Unlike
4383 software breakpoints traps, hardware watchpoint traps are
4384 always distinguishable from random traps. If no high-level
4385 watchpoint is associated with the reported stop data address
4386 anymore, then the bpstat does not explain the signal ---
4387 simply make sure to ignore it if `stopped_by_watchpoint' is
4391 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4392 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4394 && stopped_by_watchpoint)
4395 fprintf_unfiltered (gdb_stdlog,
4396 "infrun: no user watchpoint explains "
4397 "watchpoint SIGTRAP, ignoring\n");
4399 /* NOTE: cagney/2003-03-29: These checks for a random signal
4400 at one stage in the past included checks for an inferior
4401 function call's call dummy's return breakpoint. The original
4402 comment, that went with the test, read:
4404 ``End of a stack dummy. Some systems (e.g. Sony news) give
4405 another signal besides SIGTRAP, so check here as well as
4408 If someone ever tries to get call dummys on a
4409 non-executable stack to work (where the target would stop
4410 with something like a SIGSEGV), then those tests might need
4411 to be re-instated. Given, however, that the tests were only
4412 enabled when momentary breakpoints were not being used, I
4413 suspect that it won't be the case.
4415 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4416 be necessary for call dummies on a non-executable stack on
4419 /* See if the breakpoints module can explain the signal. */
4421 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4422 ecs->event_thread->suspend.stop_signal);
4424 /* If not, perhaps stepping/nexting can. */
4426 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4427 && currently_stepping (ecs->event_thread));
4429 /* Perhaps the thread hit a single-step breakpoint of _another_
4430 thread. Single-step breakpoints are transparent to the
4431 breakpoints module. */
4433 random_signal = !ecs->hit_singlestep_breakpoint;
4435 /* No? Perhaps we got a moribund watchpoint. */
4437 random_signal = !stopped_by_watchpoint;
4439 /* For the program's own signals, act according to
4440 the signal handling tables. */
4444 /* Signal not for debugging purposes. */
4445 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4446 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
4449 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
4450 gdb_signal_to_symbol_string (stop_signal));
4452 stopped_by_random_signal = 1;
4454 /* Always stop on signals if we're either just gaining control
4455 of the program, or the user explicitly requested this thread
4456 to remain stopped. */
4457 if (stop_soon != NO_STOP_QUIETLY
4458 || ecs->event_thread->stop_requested
4460 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4466 /* Notify observers the signal has "handle print" set. Note we
4467 returned early above if stopping; normal_stop handles the
4468 printing in that case. */
4469 if (signal_print[ecs->event_thread->suspend.stop_signal])
4471 /* The signal table tells us to print about this signal. */
4472 target_terminal_ours_for_output ();
4473 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
4474 target_terminal_inferior ();
4477 /* Clear the signal if it should not be passed. */
4478 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4479 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4481 if (ecs->event_thread->prev_pc == stop_pc
4482 && ecs->event_thread->control.trap_expected
4483 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4485 /* We were just starting a new sequence, attempting to
4486 single-step off of a breakpoint and expecting a SIGTRAP.
4487 Instead this signal arrives. This signal will take us out
4488 of the stepping range so GDB needs to remember to, when
4489 the signal handler returns, resume stepping off that
4491 /* To simplify things, "continue" is forced to use the same
4492 code paths as single-step - set a breakpoint at the
4493 signal return address and then, once hit, step off that
4496 fprintf_unfiltered (gdb_stdlog,
4497 "infrun: signal arrived while stepping over "
4500 insert_hp_step_resume_breakpoint_at_frame (frame);
4501 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4502 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4503 ecs->event_thread->control.trap_expected = 0;
4505 /* If we were nexting/stepping some other thread, switch to
4506 it, so that we don't continue it, losing control. */
4507 if (!switch_back_to_stepped_thread (ecs))
4512 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4513 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
4514 || ecs->event_thread->control.step_range_end == 1)
4515 && frame_id_eq (get_stack_frame_id (frame),
4516 ecs->event_thread->control.step_stack_frame_id)
4517 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4519 /* The inferior is about to take a signal that will take it
4520 out of the single step range. Set a breakpoint at the
4521 current PC (which is presumably where the signal handler
4522 will eventually return) and then allow the inferior to
4525 Note that this is only needed for a signal delivered
4526 while in the single-step range. Nested signals aren't a
4527 problem as they eventually all return. */
4529 fprintf_unfiltered (gdb_stdlog,
4530 "infrun: signal may take us out of "
4531 "single-step range\n");
4533 insert_hp_step_resume_breakpoint_at_frame (frame);
4534 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4535 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4536 ecs->event_thread->control.trap_expected = 0;
4541 /* Note: step_resume_breakpoint may be non-NULL. This occures
4542 when either there's a nested signal, or when there's a
4543 pending signal enabled just as the signal handler returns
4544 (leaving the inferior at the step-resume-breakpoint without
4545 actually executing it). Either way continue until the
4546 breakpoint is really hit. */
4548 if (!switch_back_to_stepped_thread (ecs))
4551 fprintf_unfiltered (gdb_stdlog,
4552 "infrun: random signal, keep going\n");
4559 process_event_stop_test (ecs);
4562 /* Come here when we've got some debug event / signal we can explain
4563 (IOW, not a random signal), and test whether it should cause a
4564 stop, or whether we should resume the inferior (transparently).
4565 E.g., could be a breakpoint whose condition evaluates false; we
4566 could be still stepping within the line; etc. */
4569 process_event_stop_test (struct execution_control_state *ecs)
4571 struct symtab_and_line stop_pc_sal;
4572 struct frame_info *frame;
4573 struct gdbarch *gdbarch;
4574 CORE_ADDR jmp_buf_pc;
4575 struct bpstat_what what;
4577 /* Handle cases caused by hitting a breakpoint. */
4579 frame = get_current_frame ();
4580 gdbarch = get_frame_arch (frame);
4582 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4584 if (what.call_dummy)
4586 stop_stack_dummy = what.call_dummy;
4589 /* If we hit an internal event that triggers symbol changes, the
4590 current frame will be invalidated within bpstat_what (e.g., if we
4591 hit an internal solib event). Re-fetch it. */
4592 frame = get_current_frame ();
4593 gdbarch = get_frame_arch (frame);
4595 switch (what.main_action)
4597 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4598 /* If we hit the breakpoint at longjmp while stepping, we
4599 install a momentary breakpoint at the target of the
4603 fprintf_unfiltered (gdb_stdlog,
4604 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4606 ecs->event_thread->stepping_over_breakpoint = 1;
4608 if (what.is_longjmp)
4610 struct value *arg_value;
4612 /* If we set the longjmp breakpoint via a SystemTap probe,
4613 then use it to extract the arguments. The destination PC
4614 is the third argument to the probe. */
4615 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4618 jmp_buf_pc = value_as_address (arg_value);
4619 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
4621 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4622 || !gdbarch_get_longjmp_target (gdbarch,
4623 frame, &jmp_buf_pc))
4626 fprintf_unfiltered (gdb_stdlog,
4627 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4628 "(!gdbarch_get_longjmp_target)\n");
4633 /* Insert a breakpoint at resume address. */
4634 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4637 check_exception_resume (ecs, frame);
4641 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4643 struct frame_info *init_frame;
4645 /* There are several cases to consider.
4647 1. The initiating frame no longer exists. In this case we
4648 must stop, because the exception or longjmp has gone too
4651 2. The initiating frame exists, and is the same as the
4652 current frame. We stop, because the exception or longjmp
4655 3. The initiating frame exists and is different from the
4656 current frame. This means the exception or longjmp has
4657 been caught beneath the initiating frame, so keep going.
4659 4. longjmp breakpoint has been placed just to protect
4660 against stale dummy frames and user is not interested in
4661 stopping around longjmps. */
4664 fprintf_unfiltered (gdb_stdlog,
4665 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4667 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4669 delete_exception_resume_breakpoint (ecs->event_thread);
4671 if (what.is_longjmp)
4673 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
4675 if (!frame_id_p (ecs->event_thread->initiating_frame))
4683 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4687 struct frame_id current_id
4688 = get_frame_id (get_current_frame ());
4689 if (frame_id_eq (current_id,
4690 ecs->event_thread->initiating_frame))
4692 /* Case 2. Fall through. */
4702 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
4704 delete_step_resume_breakpoint (ecs->event_thread);
4706 end_stepping_range (ecs);
4710 case BPSTAT_WHAT_SINGLE:
4712 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4713 ecs->event_thread->stepping_over_breakpoint = 1;
4714 /* Still need to check other stuff, at least the case where we
4715 are stepping and step out of the right range. */
4718 case BPSTAT_WHAT_STEP_RESUME:
4720 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4722 delete_step_resume_breakpoint (ecs->event_thread);
4723 if (ecs->event_thread->control.proceed_to_finish
4724 && execution_direction == EXEC_REVERSE)
4726 struct thread_info *tp = ecs->event_thread;
4728 /* We are finishing a function in reverse, and just hit the
4729 step-resume breakpoint at the start address of the
4730 function, and we're almost there -- just need to back up
4731 by one more single-step, which should take us back to the
4733 tp->control.step_range_start = tp->control.step_range_end = 1;
4737 fill_in_stop_func (gdbarch, ecs);
4738 if (stop_pc == ecs->stop_func_start
4739 && execution_direction == EXEC_REVERSE)
4741 /* We are stepping over a function call in reverse, and just
4742 hit the step-resume breakpoint at the start address of
4743 the function. Go back to single-stepping, which should
4744 take us back to the function call. */
4745 ecs->event_thread->stepping_over_breakpoint = 1;
4751 case BPSTAT_WHAT_STOP_NOISY:
4753 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4754 stop_print_frame = 1;
4756 /* Assume the thread stopped for a breapoint. We'll still check
4757 whether a/the breakpoint is there when the thread is next
4759 ecs->event_thread->stepping_over_breakpoint = 1;
4764 case BPSTAT_WHAT_STOP_SILENT:
4766 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4767 stop_print_frame = 0;
4769 /* Assume the thread stopped for a breapoint. We'll still check
4770 whether a/the breakpoint is there when the thread is next
4772 ecs->event_thread->stepping_over_breakpoint = 1;
4776 case BPSTAT_WHAT_HP_STEP_RESUME:
4778 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4780 delete_step_resume_breakpoint (ecs->event_thread);
4781 if (ecs->event_thread->step_after_step_resume_breakpoint)
4783 /* Back when the step-resume breakpoint was inserted, we
4784 were trying to single-step off a breakpoint. Go back to
4786 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4787 ecs->event_thread->stepping_over_breakpoint = 1;
4793 case BPSTAT_WHAT_KEEP_CHECKING:
4797 /* We come here if we hit a breakpoint but should not stop for it.
4798 Possibly we also were stepping and should stop for that. So fall
4799 through and test for stepping. But, if not stepping, do not
4802 /* In all-stop mode, if we're currently stepping but have stopped in
4803 some other thread, we need to switch back to the stepped thread. */
4804 if (switch_back_to_stepped_thread (ecs))
4807 if (ecs->event_thread->control.step_resume_breakpoint)
4810 fprintf_unfiltered (gdb_stdlog,
4811 "infrun: step-resume breakpoint is inserted\n");
4813 /* Having a step-resume breakpoint overrides anything
4814 else having to do with stepping commands until
4815 that breakpoint is reached. */
4820 if (ecs->event_thread->control.step_range_end == 0)
4823 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4824 /* Likewise if we aren't even stepping. */
4829 /* Re-fetch current thread's frame in case the code above caused
4830 the frame cache to be re-initialized, making our FRAME variable
4831 a dangling pointer. */
4832 frame = get_current_frame ();
4833 gdbarch = get_frame_arch (frame);
4834 fill_in_stop_func (gdbarch, ecs);
4836 /* If stepping through a line, keep going if still within it.
4838 Note that step_range_end is the address of the first instruction
4839 beyond the step range, and NOT the address of the last instruction
4842 Note also that during reverse execution, we may be stepping
4843 through a function epilogue and therefore must detect when
4844 the current-frame changes in the middle of a line. */
4846 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
4847 && (execution_direction != EXEC_REVERSE
4848 || frame_id_eq (get_frame_id (frame),
4849 ecs->event_thread->control.step_frame_id)))
4853 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4854 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4855 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4857 /* Tentatively re-enable range stepping; `resume' disables it if
4858 necessary (e.g., if we're stepping over a breakpoint or we
4859 have software watchpoints). */
4860 ecs->event_thread->control.may_range_step = 1;
4862 /* When stepping backward, stop at beginning of line range
4863 (unless it's the function entry point, in which case
4864 keep going back to the call point). */
4865 if (stop_pc == ecs->event_thread->control.step_range_start
4866 && stop_pc != ecs->stop_func_start
4867 && execution_direction == EXEC_REVERSE)
4868 end_stepping_range (ecs);
4875 /* We stepped out of the stepping range. */
4877 /* If we are stepping at the source level and entered the runtime
4878 loader dynamic symbol resolution code...
4880 EXEC_FORWARD: we keep on single stepping until we exit the run
4881 time loader code and reach the callee's address.
4883 EXEC_REVERSE: we've already executed the callee (backward), and
4884 the runtime loader code is handled just like any other
4885 undebuggable function call. Now we need only keep stepping
4886 backward through the trampoline code, and that's handled further
4887 down, so there is nothing for us to do here. */
4889 if (execution_direction != EXEC_REVERSE
4890 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4891 && in_solib_dynsym_resolve_code (stop_pc))
4893 CORE_ADDR pc_after_resolver =
4894 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4897 fprintf_unfiltered (gdb_stdlog,
4898 "infrun: stepped into dynsym resolve code\n");
4900 if (pc_after_resolver)
4902 /* Set up a step-resume breakpoint at the address
4903 indicated by SKIP_SOLIB_RESOLVER. */
4904 struct symtab_and_line sr_sal;
4907 sr_sal.pc = pc_after_resolver;
4908 sr_sal.pspace = get_frame_program_space (frame);
4910 insert_step_resume_breakpoint_at_sal (gdbarch,
4911 sr_sal, null_frame_id);
4918 if (ecs->event_thread->control.step_range_end != 1
4919 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4920 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4921 && get_frame_type (frame) == SIGTRAMP_FRAME)
4924 fprintf_unfiltered (gdb_stdlog,
4925 "infrun: stepped into signal trampoline\n");
4926 /* The inferior, while doing a "step" or "next", has ended up in
4927 a signal trampoline (either by a signal being delivered or by
4928 the signal handler returning). Just single-step until the
4929 inferior leaves the trampoline (either by calling the handler
4935 /* If we're in the return path from a shared library trampoline,
4936 we want to proceed through the trampoline when stepping. */
4937 /* macro/2012-04-25: This needs to come before the subroutine
4938 call check below as on some targets return trampolines look
4939 like subroutine calls (MIPS16 return thunks). */
4940 if (gdbarch_in_solib_return_trampoline (gdbarch,
4941 stop_pc, ecs->stop_func_name)
4942 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4944 /* Determine where this trampoline returns. */
4945 CORE_ADDR real_stop_pc;
4947 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4950 fprintf_unfiltered (gdb_stdlog,
4951 "infrun: stepped into solib return tramp\n");
4953 /* Only proceed through if we know where it's going. */
4956 /* And put the step-breakpoint there and go until there. */
4957 struct symtab_and_line sr_sal;
4959 init_sal (&sr_sal); /* initialize to zeroes */
4960 sr_sal.pc = real_stop_pc;
4961 sr_sal.section = find_pc_overlay (sr_sal.pc);
4962 sr_sal.pspace = get_frame_program_space (frame);
4964 /* Do not specify what the fp should be when we stop since
4965 on some machines the prologue is where the new fp value
4967 insert_step_resume_breakpoint_at_sal (gdbarch,
4968 sr_sal, null_frame_id);
4970 /* Restart without fiddling with the step ranges or
4977 /* Check for subroutine calls. The check for the current frame
4978 equalling the step ID is not necessary - the check of the
4979 previous frame's ID is sufficient - but it is a common case and
4980 cheaper than checking the previous frame's ID.
4982 NOTE: frame_id_eq will never report two invalid frame IDs as
4983 being equal, so to get into this block, both the current and
4984 previous frame must have valid frame IDs. */
4985 /* The outer_frame_id check is a heuristic to detect stepping
4986 through startup code. If we step over an instruction which
4987 sets the stack pointer from an invalid value to a valid value,
4988 we may detect that as a subroutine call from the mythical
4989 "outermost" function. This could be fixed by marking
4990 outermost frames as !stack_p,code_p,special_p. Then the
4991 initial outermost frame, before sp was valid, would
4992 have code_addr == &_start. See the comment in frame_id_eq
4994 if (!frame_id_eq (get_stack_frame_id (frame),
4995 ecs->event_thread->control.step_stack_frame_id)
4996 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4997 ecs->event_thread->control.step_stack_frame_id)
4998 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
5000 || step_start_function != find_pc_function (stop_pc))))
5002 CORE_ADDR real_stop_pc;
5005 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
5007 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
5009 /* I presume that step_over_calls is only 0 when we're
5010 supposed to be stepping at the assembly language level
5011 ("stepi"). Just stop. */
5012 /* And this works the same backward as frontward. MVS */
5013 end_stepping_range (ecs);
5017 /* Reverse stepping through solib trampolines. */
5019 if (execution_direction == EXEC_REVERSE
5020 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
5021 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5022 || (ecs->stop_func_start == 0
5023 && in_solib_dynsym_resolve_code (stop_pc))))
5025 /* Any solib trampoline code can be handled in reverse
5026 by simply continuing to single-step. We have already
5027 executed the solib function (backwards), and a few
5028 steps will take us back through the trampoline to the
5034 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5036 /* We're doing a "next".
5038 Normal (forward) execution: set a breakpoint at the
5039 callee's return address (the address at which the caller
5042 Reverse (backward) execution. set the step-resume
5043 breakpoint at the start of the function that we just
5044 stepped into (backwards), and continue to there. When we
5045 get there, we'll need to single-step back to the caller. */
5047 if (execution_direction == EXEC_REVERSE)
5049 /* If we're already at the start of the function, we've either
5050 just stepped backward into a single instruction function,
5051 or stepped back out of a signal handler to the first instruction
5052 of the function. Just keep going, which will single-step back
5054 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
5056 struct symtab_and_line sr_sal;
5058 /* Normal function call return (static or dynamic). */
5060 sr_sal.pc = ecs->stop_func_start;
5061 sr_sal.pspace = get_frame_program_space (frame);
5062 insert_step_resume_breakpoint_at_sal (gdbarch,
5063 sr_sal, null_frame_id);
5067 insert_step_resume_breakpoint_at_caller (frame);
5073 /* If we are in a function call trampoline (a stub between the
5074 calling routine and the real function), locate the real
5075 function. That's what tells us (a) whether we want to step
5076 into it at all, and (b) what prologue we want to run to the
5077 end of, if we do step into it. */
5078 real_stop_pc = skip_language_trampoline (frame, stop_pc);
5079 if (real_stop_pc == 0)
5080 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
5081 if (real_stop_pc != 0)
5082 ecs->stop_func_start = real_stop_pc;
5084 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
5086 struct symtab_and_line sr_sal;
5089 sr_sal.pc = ecs->stop_func_start;
5090 sr_sal.pspace = get_frame_program_space (frame);
5092 insert_step_resume_breakpoint_at_sal (gdbarch,
5093 sr_sal, null_frame_id);
5098 /* If we have line number information for the function we are
5099 thinking of stepping into and the function isn't on the skip
5102 If there are several symtabs at that PC (e.g. with include
5103 files), just want to know whether *any* of them have line
5104 numbers. find_pc_line handles this. */
5106 struct symtab_and_line tmp_sal;
5108 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
5109 if (tmp_sal.line != 0
5110 && !function_name_is_marked_for_skip (ecs->stop_func_name,
5113 if (execution_direction == EXEC_REVERSE)
5114 handle_step_into_function_backward (gdbarch, ecs);
5116 handle_step_into_function (gdbarch, ecs);
5121 /* If we have no line number and the step-stop-if-no-debug is
5122 set, we stop the step so that the user has a chance to switch
5123 in assembly mode. */
5124 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5125 && step_stop_if_no_debug)
5127 end_stepping_range (ecs);
5131 if (execution_direction == EXEC_REVERSE)
5133 /* If we're already at the start of the function, we've either just
5134 stepped backward into a single instruction function without line
5135 number info, or stepped back out of a signal handler to the first
5136 instruction of the function without line number info. Just keep
5137 going, which will single-step back to the caller. */
5138 if (ecs->stop_func_start != stop_pc)
5140 /* Set a breakpoint at callee's start address.
5141 From there we can step once and be back in the caller. */
5142 struct symtab_and_line sr_sal;
5145 sr_sal.pc = ecs->stop_func_start;
5146 sr_sal.pspace = get_frame_program_space (frame);
5147 insert_step_resume_breakpoint_at_sal (gdbarch,
5148 sr_sal, null_frame_id);
5152 /* Set a breakpoint at callee's return address (the address
5153 at which the caller will resume). */
5154 insert_step_resume_breakpoint_at_caller (frame);
5160 /* Reverse stepping through solib trampolines. */
5162 if (execution_direction == EXEC_REVERSE
5163 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5165 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5166 || (ecs->stop_func_start == 0
5167 && in_solib_dynsym_resolve_code (stop_pc)))
5169 /* Any solib trampoline code can be handled in reverse
5170 by simply continuing to single-step. We have already
5171 executed the solib function (backwards), and a few
5172 steps will take us back through the trampoline to the
5177 else if (in_solib_dynsym_resolve_code (stop_pc))
5179 /* Stepped backward into the solib dynsym resolver.
5180 Set a breakpoint at its start and continue, then
5181 one more step will take us out. */
5182 struct symtab_and_line sr_sal;
5185 sr_sal.pc = ecs->stop_func_start;
5186 sr_sal.pspace = get_frame_program_space (frame);
5187 insert_step_resume_breakpoint_at_sal (gdbarch,
5188 sr_sal, null_frame_id);
5194 stop_pc_sal = find_pc_line (stop_pc, 0);
5196 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5197 the trampoline processing logic, however, there are some trampolines
5198 that have no names, so we should do trampoline handling first. */
5199 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5200 && ecs->stop_func_name == NULL
5201 && stop_pc_sal.line == 0)
5204 fprintf_unfiltered (gdb_stdlog,
5205 "infrun: stepped into undebuggable function\n");
5207 /* The inferior just stepped into, or returned to, an
5208 undebuggable function (where there is no debugging information
5209 and no line number corresponding to the address where the
5210 inferior stopped). Since we want to skip this kind of code,
5211 we keep going until the inferior returns from this
5212 function - unless the user has asked us not to (via
5213 set step-mode) or we no longer know how to get back
5214 to the call site. */
5215 if (step_stop_if_no_debug
5216 || !frame_id_p (frame_unwind_caller_id (frame)))
5218 /* If we have no line number and the step-stop-if-no-debug
5219 is set, we stop the step so that the user has a chance to
5220 switch in assembly mode. */
5221 end_stepping_range (ecs);
5226 /* Set a breakpoint at callee's return address (the address
5227 at which the caller will resume). */
5228 insert_step_resume_breakpoint_at_caller (frame);
5234 if (ecs->event_thread->control.step_range_end == 1)
5236 /* It is stepi or nexti. We always want to stop stepping after
5239 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5240 end_stepping_range (ecs);
5244 if (stop_pc_sal.line == 0)
5246 /* We have no line number information. That means to stop
5247 stepping (does this always happen right after one instruction,
5248 when we do "s" in a function with no line numbers,
5249 or can this happen as a result of a return or longjmp?). */
5251 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5252 end_stepping_range (ecs);
5256 /* Look for "calls" to inlined functions, part one. If the inline
5257 frame machinery detected some skipped call sites, we have entered
5258 a new inline function. */
5260 if (frame_id_eq (get_frame_id (get_current_frame ()),
5261 ecs->event_thread->control.step_frame_id)
5262 && inline_skipped_frames (ecs->ptid))
5264 struct symtab_and_line call_sal;
5267 fprintf_unfiltered (gdb_stdlog,
5268 "infrun: stepped into inlined function\n");
5270 find_frame_sal (get_current_frame (), &call_sal);
5272 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5274 /* For "step", we're going to stop. But if the call site
5275 for this inlined function is on the same source line as
5276 we were previously stepping, go down into the function
5277 first. Otherwise stop at the call site. */
5279 if (call_sal.line == ecs->event_thread->current_line
5280 && call_sal.symtab == ecs->event_thread->current_symtab)
5281 step_into_inline_frame (ecs->ptid);
5283 end_stepping_range (ecs);
5288 /* For "next", we should stop at the call site if it is on a
5289 different source line. Otherwise continue through the
5290 inlined function. */
5291 if (call_sal.line == ecs->event_thread->current_line
5292 && call_sal.symtab == ecs->event_thread->current_symtab)
5295 end_stepping_range (ecs);
5300 /* Look for "calls" to inlined functions, part two. If we are still
5301 in the same real function we were stepping through, but we have
5302 to go further up to find the exact frame ID, we are stepping
5303 through a more inlined call beyond its call site. */
5305 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5306 && !frame_id_eq (get_frame_id (get_current_frame ()),
5307 ecs->event_thread->control.step_frame_id)
5308 && stepped_in_from (get_current_frame (),
5309 ecs->event_thread->control.step_frame_id))
5312 fprintf_unfiltered (gdb_stdlog,
5313 "infrun: stepping through inlined function\n");
5315 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5318 end_stepping_range (ecs);
5322 if ((stop_pc == stop_pc_sal.pc)
5323 && (ecs->event_thread->current_line != stop_pc_sal.line
5324 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5326 /* We are at the start of a different line. So stop. Note that
5327 we don't stop if we step into the middle of a different line.
5328 That is said to make things like for (;;) statements work
5331 fprintf_unfiltered (gdb_stdlog,
5332 "infrun: stepped to a different line\n");
5333 end_stepping_range (ecs);
5337 /* We aren't done stepping.
5339 Optimize by setting the stepping range to the line.
5340 (We might not be in the original line, but if we entered a
5341 new line in mid-statement, we continue stepping. This makes
5342 things like for(;;) statements work better.) */
5344 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5345 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5346 ecs->event_thread->control.may_range_step = 1;
5347 set_step_info (frame, stop_pc_sal);
5350 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5354 /* In all-stop mode, if we're currently stepping but have stopped in
5355 some other thread, we may need to switch back to the stepped
5356 thread. Returns true we set the inferior running, false if we left
5357 it stopped (and the event needs further processing). */
5360 switch_back_to_stepped_thread (struct execution_control_state *ecs)
5364 struct thread_info *tp;
5365 struct thread_info *stepping_thread;
5366 struct thread_info *step_over;
5368 /* If any thread is blocked on some internal breakpoint, and we
5369 simply need to step over that breakpoint to get it going
5370 again, do that first. */
5372 /* However, if we see an event for the stepping thread, then we
5373 know all other threads have been moved past their breakpoints
5374 already. Let the caller check whether the step is finished,
5375 etc., before deciding to move it past a breakpoint. */
5376 if (ecs->event_thread->control.step_range_end != 0)
5379 /* Check if the current thread is blocked on an incomplete
5380 step-over, interrupted by a random signal. */
5381 if (ecs->event_thread->control.trap_expected
5382 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5386 fprintf_unfiltered (gdb_stdlog,
5387 "infrun: need to finish step-over of [%s]\n",
5388 target_pid_to_str (ecs->event_thread->ptid));
5394 /* Check if the current thread is blocked by a single-step
5395 breakpoint of another thread. */
5396 if (ecs->hit_singlestep_breakpoint)
5400 fprintf_unfiltered (gdb_stdlog,
5401 "infrun: need to step [%s] over single-step "
5403 target_pid_to_str (ecs->ptid));
5409 /* Otherwise, we no longer expect a trap in the current thread.
5410 Clear the trap_expected flag before switching back -- this is
5411 what keep_going does as well, if we call it. */
5412 ecs->event_thread->control.trap_expected = 0;
5414 /* Likewise, clear the signal if it should not be passed. */
5415 if (!signal_program[ecs->event_thread->suspend.stop_signal])
5416 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5418 /* If scheduler locking applies even if not stepping, there's no
5419 need to walk over threads. Above we've checked whether the
5420 current thread is stepping. If some other thread not the
5421 event thread is stepping, then it must be that scheduler
5422 locking is not in effect. */
5423 if (schedlock_applies (0))
5426 /* Look for the stepping/nexting thread, and check if any other
5427 thread other than the stepping thread needs to start a
5428 step-over. Do all step-overs before actually proceeding with
5430 stepping_thread = NULL;
5432 ALL_NON_EXITED_THREADS (tp)
5434 /* Ignore threads of processes we're not resuming. */
5436 && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
5439 /* When stepping over a breakpoint, we lock all threads
5440 except the one that needs to move past the breakpoint.
5441 If a non-event thread has this set, the "incomplete
5442 step-over" check above should have caught it earlier. */
5443 gdb_assert (!tp->control.trap_expected);
5445 /* Did we find the stepping thread? */
5446 if (tp->control.step_range_end)
5448 /* Yep. There should only one though. */
5449 gdb_assert (stepping_thread == NULL);
5451 /* The event thread is handled at the top, before we
5453 gdb_assert (tp != ecs->event_thread);
5455 /* If some thread other than the event thread is
5456 stepping, then scheduler locking can't be in effect,
5457 otherwise we wouldn't have resumed the current event
5458 thread in the first place. */
5459 gdb_assert (!schedlock_applies (currently_stepping (tp)));
5461 stepping_thread = tp;
5463 else if (thread_still_needs_step_over (tp))
5467 /* At the top we've returned early if the event thread
5468 is stepping. If some other thread not the event
5469 thread is stepping, then scheduler locking can't be
5470 in effect, and we can resume this thread. No need to
5471 keep looking for the stepping thread then. */
5476 if (step_over != NULL)
5481 fprintf_unfiltered (gdb_stdlog,
5482 "infrun: need to step-over [%s]\n",
5483 target_pid_to_str (tp->ptid));
5486 /* Only the stepping thread should have this set. */
5487 gdb_assert (tp->control.step_range_end == 0);
5489 ecs->ptid = tp->ptid;
5490 ecs->event_thread = tp;
5491 switch_to_thread (ecs->ptid);
5496 if (stepping_thread != NULL)
5498 struct frame_info *frame;
5499 struct gdbarch *gdbarch;
5501 tp = stepping_thread;
5503 /* If the stepping thread exited, then don't try to switch
5504 back and resume it, which could fail in several different
5505 ways depending on the target. Instead, just keep going.
5507 We can find a stepping dead thread in the thread list in
5510 - The target supports thread exit events, and when the
5511 target tries to delete the thread from the thread list,
5512 inferior_ptid pointed at the exiting thread. In such
5513 case, calling delete_thread does not really remove the
5514 thread from the list; instead, the thread is left listed,
5515 with 'exited' state.
5517 - The target's debug interface does not support thread
5518 exit events, and so we have no idea whatsoever if the
5519 previously stepping thread is still alive. For that
5520 reason, we need to synchronously query the target
5522 if (is_exited (tp->ptid)
5523 || !target_thread_alive (tp->ptid))
5526 fprintf_unfiltered (gdb_stdlog,
5527 "infrun: not switching back to "
5528 "stepped thread, it has vanished\n");
5530 delete_thread (tp->ptid);
5536 fprintf_unfiltered (gdb_stdlog,
5537 "infrun: switching back to stepped thread\n");
5539 ecs->event_thread = tp;
5540 ecs->ptid = tp->ptid;
5541 context_switch (ecs->ptid);
5543 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5544 frame = get_current_frame ();
5545 gdbarch = get_frame_arch (frame);
5547 /* If the PC of the thread we were trying to single-step has
5548 changed, then that thread has trapped or been signaled,
5549 but the event has not been reported to GDB yet. Re-poll
5550 the target looking for this particular thread's event
5551 (i.e. temporarily enable schedlock) by:
5553 - setting a break at the current PC
5554 - resuming that particular thread, only (by setting
5557 This prevents us continuously moving the single-step
5558 breakpoint forward, one instruction at a time,
5561 if (gdbarch_software_single_step_p (gdbarch)
5562 && stop_pc != tp->prev_pc)
5565 fprintf_unfiltered (gdb_stdlog,
5566 "infrun: expected thread advanced also\n");
5568 /* Clear the info of the previous step-over, as it's no
5569 longer valid. It's what keep_going would do too, if
5570 we called it. Must do this before trying to insert
5571 the sss breakpoint, otherwise if we were previously
5572 trying to step over this exact address in another
5573 thread, the breakpoint ends up not installed. */
5574 clear_step_over_info ();
5576 insert_single_step_breakpoint (get_frame_arch (frame),
5577 get_frame_address_space (frame),
5579 ecs->event_thread->control.trap_expected = 1;
5581 resume (0, GDB_SIGNAL_0);
5582 prepare_to_wait (ecs);
5587 fprintf_unfiltered (gdb_stdlog,
5588 "infrun: expected thread still "
5589 "hasn't advanced\n");
5599 /* Is thread TP in the middle of single-stepping? */
5602 currently_stepping (struct thread_info *tp)
5604 return ((tp->control.step_range_end
5605 && tp->control.step_resume_breakpoint == NULL)
5606 || tp->control.trap_expected
5607 || bpstat_should_step ());
5610 /* Inferior has stepped into a subroutine call with source code that
5611 we should not step over. Do step to the first line of code in
5615 handle_step_into_function (struct gdbarch *gdbarch,
5616 struct execution_control_state *ecs)
5619 struct symtab_and_line stop_func_sal, sr_sal;
5621 fill_in_stop_func (gdbarch, ecs);
5623 s = find_pc_symtab (stop_pc);
5624 if (s && s->language != language_asm)
5625 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5626 ecs->stop_func_start);
5628 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5629 /* Use the step_resume_break to step until the end of the prologue,
5630 even if that involves jumps (as it seems to on the vax under
5632 /* If the prologue ends in the middle of a source line, continue to
5633 the end of that source line (if it is still within the function).
5634 Otherwise, just go to end of prologue. */
5635 if (stop_func_sal.end
5636 && stop_func_sal.pc != ecs->stop_func_start
5637 && stop_func_sal.end < ecs->stop_func_end)
5638 ecs->stop_func_start = stop_func_sal.end;
5640 /* Architectures which require breakpoint adjustment might not be able
5641 to place a breakpoint at the computed address. If so, the test
5642 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5643 ecs->stop_func_start to an address at which a breakpoint may be
5644 legitimately placed.
5646 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5647 made, GDB will enter an infinite loop when stepping through
5648 optimized code consisting of VLIW instructions which contain
5649 subinstructions corresponding to different source lines. On
5650 FR-V, it's not permitted to place a breakpoint on any but the
5651 first subinstruction of a VLIW instruction. When a breakpoint is
5652 set, GDB will adjust the breakpoint address to the beginning of
5653 the VLIW instruction. Thus, we need to make the corresponding
5654 adjustment here when computing the stop address. */
5656 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5658 ecs->stop_func_start
5659 = gdbarch_adjust_breakpoint_address (gdbarch,
5660 ecs->stop_func_start);
5663 if (ecs->stop_func_start == stop_pc)
5665 /* We are already there: stop now. */
5666 end_stepping_range (ecs);
5671 /* Put the step-breakpoint there and go until there. */
5672 init_sal (&sr_sal); /* initialize to zeroes */
5673 sr_sal.pc = ecs->stop_func_start;
5674 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5675 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5677 /* Do not specify what the fp should be when we stop since on
5678 some machines the prologue is where the new fp value is
5680 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5682 /* And make sure stepping stops right away then. */
5683 ecs->event_thread->control.step_range_end
5684 = ecs->event_thread->control.step_range_start;
5689 /* Inferior has stepped backward into a subroutine call with source
5690 code that we should not step over. Do step to the beginning of the
5691 last line of code in it. */
5694 handle_step_into_function_backward (struct gdbarch *gdbarch,
5695 struct execution_control_state *ecs)
5698 struct symtab_and_line stop_func_sal;
5700 fill_in_stop_func (gdbarch, ecs);
5702 s = find_pc_symtab (stop_pc);
5703 if (s && s->language != language_asm)
5704 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5705 ecs->stop_func_start);
5707 stop_func_sal = find_pc_line (stop_pc, 0);
5709 /* OK, we're just going to keep stepping here. */
5710 if (stop_func_sal.pc == stop_pc)
5712 /* We're there already. Just stop stepping now. */
5713 end_stepping_range (ecs);
5717 /* Else just reset the step range and keep going.
5718 No step-resume breakpoint, they don't work for
5719 epilogues, which can have multiple entry paths. */
5720 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5721 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5727 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5728 This is used to both functions and to skip over code. */
5731 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5732 struct symtab_and_line sr_sal,
5733 struct frame_id sr_id,
5734 enum bptype sr_type)
5736 /* There should never be more than one step-resume or longjmp-resume
5737 breakpoint per thread, so we should never be setting a new
5738 step_resume_breakpoint when one is already active. */
5739 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5740 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5743 fprintf_unfiltered (gdb_stdlog,
5744 "infrun: inserting step-resume breakpoint at %s\n",
5745 paddress (gdbarch, sr_sal.pc));
5747 inferior_thread ()->control.step_resume_breakpoint
5748 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5752 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5753 struct symtab_and_line sr_sal,
5754 struct frame_id sr_id)
5756 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5761 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5762 This is used to skip a potential signal handler.
5764 This is called with the interrupted function's frame. The signal
5765 handler, when it returns, will resume the interrupted function at
5769 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5771 struct symtab_and_line sr_sal;
5772 struct gdbarch *gdbarch;
5774 gdb_assert (return_frame != NULL);
5775 init_sal (&sr_sal); /* initialize to zeros */
5777 gdbarch = get_frame_arch (return_frame);
5778 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5779 sr_sal.section = find_pc_overlay (sr_sal.pc);
5780 sr_sal.pspace = get_frame_program_space (return_frame);
5782 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5783 get_stack_frame_id (return_frame),
5787 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5788 is used to skip a function after stepping into it (for "next" or if
5789 the called function has no debugging information).
5791 The current function has almost always been reached by single
5792 stepping a call or return instruction. NEXT_FRAME belongs to the
5793 current function, and the breakpoint will be set at the caller's
5796 This is a separate function rather than reusing
5797 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5798 get_prev_frame, which may stop prematurely (see the implementation
5799 of frame_unwind_caller_id for an example). */
5802 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5804 struct symtab_and_line sr_sal;
5805 struct gdbarch *gdbarch;
5807 /* We shouldn't have gotten here if we don't know where the call site
5809 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5811 init_sal (&sr_sal); /* initialize to zeros */
5813 gdbarch = frame_unwind_caller_arch (next_frame);
5814 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5815 frame_unwind_caller_pc (next_frame));
5816 sr_sal.section = find_pc_overlay (sr_sal.pc);
5817 sr_sal.pspace = frame_unwind_program_space (next_frame);
5819 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5820 frame_unwind_caller_id (next_frame));
5823 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5824 new breakpoint at the target of a jmp_buf. The handling of
5825 longjmp-resume uses the same mechanisms used for handling
5826 "step-resume" breakpoints. */
5829 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5831 /* There should never be more than one longjmp-resume breakpoint per
5832 thread, so we should never be setting a new
5833 longjmp_resume_breakpoint when one is already active. */
5834 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
5837 fprintf_unfiltered (gdb_stdlog,
5838 "infrun: inserting longjmp-resume breakpoint at %s\n",
5839 paddress (gdbarch, pc));
5841 inferior_thread ()->control.exception_resume_breakpoint =
5842 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5845 /* Insert an exception resume breakpoint. TP is the thread throwing
5846 the exception. The block B is the block of the unwinder debug hook
5847 function. FRAME is the frame corresponding to the call to this
5848 function. SYM is the symbol of the function argument holding the
5849 target PC of the exception. */
5852 insert_exception_resume_breakpoint (struct thread_info *tp,
5853 const struct block *b,
5854 struct frame_info *frame,
5857 volatile struct gdb_exception e;
5859 /* We want to ignore errors here. */
5860 TRY_CATCH (e, RETURN_MASK_ERROR)
5862 struct symbol *vsym;
5863 struct value *value;
5865 struct breakpoint *bp;
5867 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5868 value = read_var_value (vsym, frame);
5869 /* If the value was optimized out, revert to the old behavior. */
5870 if (! value_optimized_out (value))
5872 handler = value_as_address (value);
5875 fprintf_unfiltered (gdb_stdlog,
5876 "infrun: exception resume at %lx\n",
5877 (unsigned long) handler);
5879 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5880 handler, bp_exception_resume);
5882 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
5885 bp->thread = tp->num;
5886 inferior_thread ()->control.exception_resume_breakpoint = bp;
5891 /* A helper for check_exception_resume that sets an
5892 exception-breakpoint based on a SystemTap probe. */
5895 insert_exception_resume_from_probe (struct thread_info *tp,
5896 const struct bound_probe *probe,
5897 struct frame_info *frame)
5899 struct value *arg_value;
5901 struct breakpoint *bp;
5903 arg_value = probe_safe_evaluate_at_pc (frame, 1);
5907 handler = value_as_address (arg_value);
5910 fprintf_unfiltered (gdb_stdlog,
5911 "infrun: exception resume at %s\n",
5912 paddress (get_objfile_arch (probe->objfile),
5915 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5916 handler, bp_exception_resume);
5917 bp->thread = tp->num;
5918 inferior_thread ()->control.exception_resume_breakpoint = bp;
5921 /* This is called when an exception has been intercepted. Check to
5922 see whether the exception's destination is of interest, and if so,
5923 set an exception resume breakpoint there. */
5926 check_exception_resume (struct execution_control_state *ecs,
5927 struct frame_info *frame)
5929 volatile struct gdb_exception e;
5930 struct bound_probe probe;
5931 struct symbol *func;
5933 /* First see if this exception unwinding breakpoint was set via a
5934 SystemTap probe point. If so, the probe has two arguments: the
5935 CFA and the HANDLER. We ignore the CFA, extract the handler, and
5936 set a breakpoint there. */
5937 probe = find_probe_by_pc (get_frame_pc (frame));
5940 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
5944 func = get_frame_function (frame);
5948 TRY_CATCH (e, RETURN_MASK_ERROR)
5950 const struct block *b;
5951 struct block_iterator iter;
5955 /* The exception breakpoint is a thread-specific breakpoint on
5956 the unwinder's debug hook, declared as:
5958 void _Unwind_DebugHook (void *cfa, void *handler);
5960 The CFA argument indicates the frame to which control is
5961 about to be transferred. HANDLER is the destination PC.
5963 We ignore the CFA and set a temporary breakpoint at HANDLER.
5964 This is not extremely efficient but it avoids issues in gdb
5965 with computing the DWARF CFA, and it also works even in weird
5966 cases such as throwing an exception from inside a signal
5969 b = SYMBOL_BLOCK_VALUE (func);
5970 ALL_BLOCK_SYMBOLS (b, iter, sym)
5972 if (!SYMBOL_IS_ARGUMENT (sym))
5979 insert_exception_resume_breakpoint (ecs->event_thread,
5988 stop_waiting (struct execution_control_state *ecs)
5991 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
5993 clear_step_over_info ();
5995 /* Let callers know we don't want to wait for the inferior anymore. */
5996 ecs->wait_some_more = 0;
5999 /* Called when we should continue running the inferior, because the
6000 current event doesn't cause a user visible stop. This does the
6001 resuming part; waiting for the next event is done elsewhere. */
6004 keep_going (struct execution_control_state *ecs)
6006 /* Make sure normal_stop is called if we get a QUIT handled before
6008 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
6010 /* Save the pc before execution, to compare with pc after stop. */
6011 ecs->event_thread->prev_pc
6012 = regcache_read_pc (get_thread_regcache (ecs->ptid));
6014 if (ecs->event_thread->control.trap_expected
6015 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6017 /* We haven't yet gotten our trap, and either: intercepted a
6018 non-signal event (e.g., a fork); or took a signal which we
6019 are supposed to pass through to the inferior. Simply
6021 discard_cleanups (old_cleanups);
6022 resume (currently_stepping (ecs->event_thread),
6023 ecs->event_thread->suspend.stop_signal);
6027 volatile struct gdb_exception e;
6028 struct regcache *regcache = get_current_regcache ();
6032 /* Either the trap was not expected, but we are continuing
6033 anyway (if we got a signal, the user asked it be passed to
6036 We got our expected trap, but decided we should resume from
6039 We're going to run this baby now!
6041 Note that insert_breakpoints won't try to re-insert
6042 already inserted breakpoints. Therefore, we don't
6043 care if breakpoints were already inserted, or not. */
6045 /* If we need to step over a breakpoint, and we're not using
6046 displaced stepping to do so, insert all breakpoints
6047 (watchpoints, etc.) but the one we're stepping over, step one
6048 instruction, and then re-insert the breakpoint when that step
6051 remove_bp = (ecs->hit_singlestep_breakpoint
6052 || thread_still_needs_step_over (ecs->event_thread));
6053 remove_wps = (ecs->event_thread->stepping_over_watchpoint
6054 && !target_have_steppable_watchpoint);
6056 if (remove_bp && !use_displaced_stepping (get_regcache_arch (regcache)))
6058 set_step_over_info (get_regcache_aspace (regcache),
6059 regcache_read_pc (regcache), remove_wps);
6061 else if (remove_wps)
6062 set_step_over_info (NULL, 0, remove_wps);
6064 clear_step_over_info ();
6066 /* Stop stepping if inserting breakpoints fails. */
6067 TRY_CATCH (e, RETURN_MASK_ERROR)
6069 insert_breakpoints ();
6073 exception_print (gdb_stderr, e);
6078 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
6080 /* Do not deliver GDB_SIGNAL_TRAP (except when the user
6081 explicitly specifies that such a signal should be delivered
6082 to the target program). Typically, that would occur when a
6083 user is debugging a target monitor on a simulator: the target
6084 monitor sets a breakpoint; the simulator encounters this
6085 breakpoint and halts the simulation handing control to GDB;
6086 GDB, noting that the stop address doesn't map to any known
6087 breakpoint, returns control back to the simulator; the
6088 simulator then delivers the hardware equivalent of a
6089 GDB_SIGNAL_TRAP to the program being debugged. */
6090 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6091 && !signal_program[ecs->event_thread->suspend.stop_signal])
6092 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6094 discard_cleanups (old_cleanups);
6095 resume (currently_stepping (ecs->event_thread),
6096 ecs->event_thread->suspend.stop_signal);
6099 prepare_to_wait (ecs);
6102 /* This function normally comes after a resume, before
6103 handle_inferior_event exits. It takes care of any last bits of
6104 housekeeping, and sets the all-important wait_some_more flag. */
6107 prepare_to_wait (struct execution_control_state *ecs)
6110 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
6112 /* This is the old end of the while loop. Let everybody know we
6113 want to wait for the inferior some more and get called again
6115 ecs->wait_some_more = 1;
6118 /* We are done with the step range of a step/next/si/ni command.
6119 Called once for each n of a "step n" operation. */
6122 end_stepping_range (struct execution_control_state *ecs)
6124 ecs->event_thread->control.stop_step = 1;
6128 /* Several print_*_reason functions to print why the inferior has stopped.
6129 We always print something when the inferior exits, or receives a signal.
6130 The rest of the cases are dealt with later on in normal_stop and
6131 print_it_typical. Ideally there should be a call to one of these
6132 print_*_reason functions functions from handle_inferior_event each time
6133 stop_waiting is called.
6135 Note that we don't call these directly, instead we delegate that to
6136 the interpreters, through observers. Interpreters then call these
6137 with whatever uiout is right. */
6140 print_end_stepping_range_reason (struct ui_out *uiout)
6142 /* For CLI-like interpreters, print nothing. */
6144 if (ui_out_is_mi_like_p (uiout))
6146 ui_out_field_string (uiout, "reason",
6147 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
6152 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
6154 annotate_signalled ();
6155 if (ui_out_is_mi_like_p (uiout))
6157 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
6158 ui_out_text (uiout, "\nProgram terminated with signal ");
6159 annotate_signal_name ();
6160 ui_out_field_string (uiout, "signal-name",
6161 gdb_signal_to_name (siggnal));
6162 annotate_signal_name_end ();
6163 ui_out_text (uiout, ", ");
6164 annotate_signal_string ();
6165 ui_out_field_string (uiout, "signal-meaning",
6166 gdb_signal_to_string (siggnal));
6167 annotate_signal_string_end ();
6168 ui_out_text (uiout, ".\n");
6169 ui_out_text (uiout, "The program no longer exists.\n");
6173 print_exited_reason (struct ui_out *uiout, int exitstatus)
6175 struct inferior *inf = current_inferior ();
6176 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
6178 annotate_exited (exitstatus);
6181 if (ui_out_is_mi_like_p (uiout))
6182 ui_out_field_string (uiout, "reason",
6183 async_reason_lookup (EXEC_ASYNC_EXITED));
6184 ui_out_text (uiout, "[Inferior ");
6185 ui_out_text (uiout, plongest (inf->num));
6186 ui_out_text (uiout, " (");
6187 ui_out_text (uiout, pidstr);
6188 ui_out_text (uiout, ") exited with code ");
6189 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
6190 ui_out_text (uiout, "]\n");
6194 if (ui_out_is_mi_like_p (uiout))
6196 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
6197 ui_out_text (uiout, "[Inferior ");
6198 ui_out_text (uiout, plongest (inf->num));
6199 ui_out_text (uiout, " (");
6200 ui_out_text (uiout, pidstr);
6201 ui_out_text (uiout, ") exited normally]\n");
6206 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
6210 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
6212 struct thread_info *t = inferior_thread ();
6214 ui_out_text (uiout, "\n[");
6215 ui_out_field_string (uiout, "thread-name",
6216 target_pid_to_str (t->ptid));
6217 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
6218 ui_out_text (uiout, " stopped");
6222 ui_out_text (uiout, "\nProgram received signal ");
6223 annotate_signal_name ();
6224 if (ui_out_is_mi_like_p (uiout))
6226 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
6227 ui_out_field_string (uiout, "signal-name",
6228 gdb_signal_to_name (siggnal));
6229 annotate_signal_name_end ();
6230 ui_out_text (uiout, ", ");
6231 annotate_signal_string ();
6232 ui_out_field_string (uiout, "signal-meaning",
6233 gdb_signal_to_string (siggnal));
6234 annotate_signal_string_end ();
6236 ui_out_text (uiout, ".\n");
6240 print_no_history_reason (struct ui_out *uiout)
6242 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
6245 /* Print current location without a level number, if we have changed
6246 functions or hit a breakpoint. Print source line if we have one.
6247 bpstat_print contains the logic deciding in detail what to print,
6248 based on the event(s) that just occurred. */
6251 print_stop_event (struct target_waitstatus *ws)
6255 int do_frame_printing = 1;
6256 struct thread_info *tp = inferior_thread ();
6258 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
6262 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
6263 should) carry around the function and does (or should) use
6264 that when doing a frame comparison. */
6265 if (tp->control.stop_step
6266 && frame_id_eq (tp->control.step_frame_id,
6267 get_frame_id (get_current_frame ()))
6268 && step_start_function == find_pc_function (stop_pc))
6270 /* Finished step, just print source line. */
6271 source_flag = SRC_LINE;
6275 /* Print location and source line. */
6276 source_flag = SRC_AND_LOC;
6279 case PRINT_SRC_AND_LOC:
6280 /* Print location and source line. */
6281 source_flag = SRC_AND_LOC;
6283 case PRINT_SRC_ONLY:
6284 source_flag = SRC_LINE;
6287 /* Something bogus. */
6288 source_flag = SRC_LINE;
6289 do_frame_printing = 0;
6292 internal_error (__FILE__, __LINE__, _("Unknown value."));
6295 /* The behavior of this routine with respect to the source
6297 SRC_LINE: Print only source line
6298 LOCATION: Print only location
6299 SRC_AND_LOC: Print location and source line. */
6300 if (do_frame_printing)
6301 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
6303 /* Display the auto-display expressions. */
6307 /* Here to return control to GDB when the inferior stops for real.
6308 Print appropriate messages, remove breakpoints, give terminal our modes.
6310 STOP_PRINT_FRAME nonzero means print the executing frame
6311 (pc, function, args, file, line number and line text).
6312 BREAKPOINTS_FAILED nonzero means stop was due to error
6313 attempting to insert breakpoints. */
6318 struct target_waitstatus last;
6320 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
6322 get_last_target_status (&last_ptid, &last);
6324 /* If an exception is thrown from this point on, make sure to
6325 propagate GDB's knowledge of the executing state to the
6326 frontend/user running state. A QUIT is an easy exception to see
6327 here, so do this before any filtered output. */
6329 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
6330 else if (last.kind != TARGET_WAITKIND_SIGNALLED
6331 && last.kind != TARGET_WAITKIND_EXITED
6332 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6333 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
6335 /* As we're presenting a stop, and potentially removing breakpoints,
6336 update the thread list so we can tell whether there are threads
6337 running on the target. With target remote, for example, we can
6338 only learn about new threads when we explicitly update the thread
6339 list. Do this before notifying the interpreters about signal
6340 stops, end of stepping ranges, etc., so that the "new thread"
6341 output is emitted before e.g., "Program received signal FOO",
6342 instead of after. */
6343 update_thread_list ();
6345 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
6346 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
6348 /* As with the notification of thread events, we want to delay
6349 notifying the user that we've switched thread context until
6350 the inferior actually stops.
6352 There's no point in saying anything if the inferior has exited.
6353 Note that SIGNALLED here means "exited with a signal", not
6354 "received a signal".
6356 Also skip saying anything in non-stop mode. In that mode, as we
6357 don't want GDB to switch threads behind the user's back, to avoid
6358 races where the user is typing a command to apply to thread x,
6359 but GDB switches to thread y before the user finishes entering
6360 the command, fetch_inferior_event installs a cleanup to restore
6361 the current thread back to the thread the user had selected right
6362 after this event is handled, so we're not really switching, only
6363 informing of a stop. */
6365 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
6366 && target_has_execution
6367 && last.kind != TARGET_WAITKIND_SIGNALLED
6368 && last.kind != TARGET_WAITKIND_EXITED
6369 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6371 target_terminal_ours_for_output ();
6372 printf_filtered (_("[Switching to %s]\n"),
6373 target_pid_to_str (inferior_ptid));
6374 annotate_thread_changed ();
6375 previous_inferior_ptid = inferior_ptid;
6378 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
6380 gdb_assert (sync_execution || !target_can_async_p ());
6382 target_terminal_ours_for_output ();
6383 printf_filtered (_("No unwaited-for children left.\n"));
6386 /* Note: this depends on the update_thread_list call above. */
6387 if (!breakpoints_should_be_inserted_now () && target_has_execution)
6389 if (remove_breakpoints ())
6391 target_terminal_ours_for_output ();
6392 printf_filtered (_("Cannot remove breakpoints because "
6393 "program is no longer writable.\nFurther "
6394 "execution is probably impossible.\n"));
6398 /* If an auto-display called a function and that got a signal,
6399 delete that auto-display to avoid an infinite recursion. */
6401 if (stopped_by_random_signal)
6402 disable_current_display ();
6404 /* Notify observers if we finished a "step"-like command, etc. */
6405 if (target_has_execution
6406 && last.kind != TARGET_WAITKIND_SIGNALLED
6407 && last.kind != TARGET_WAITKIND_EXITED
6408 && inferior_thread ()->control.stop_step)
6410 /* But not if in the middle of doing a "step n" operation for
6412 if (inferior_thread ()->step_multi)
6415 observer_notify_end_stepping_range ();
6418 target_terminal_ours ();
6419 async_enable_stdin ();
6421 /* Set the current source location. This will also happen if we
6422 display the frame below, but the current SAL will be incorrect
6423 during a user hook-stop function. */
6424 if (has_stack_frames () && !stop_stack_dummy)
6425 set_current_sal_from_frame (get_current_frame ());
6427 /* Let the user/frontend see the threads as stopped, but do nothing
6428 if the thread was running an infcall. We may be e.g., evaluating
6429 a breakpoint condition. In that case, the thread had state
6430 THREAD_RUNNING before the infcall, and shall remain set to
6431 running, all without informing the user/frontend about state
6432 transition changes. If this is actually a call command, then the
6433 thread was originally already stopped, so there's no state to
6435 if (target_has_execution && inferior_thread ()->control.in_infcall)
6436 discard_cleanups (old_chain);
6438 do_cleanups (old_chain);
6440 /* Look up the hook_stop and run it (CLI internally handles problem
6441 of stop_command's pre-hook not existing). */
6443 catch_errors (hook_stop_stub, stop_command,
6444 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6446 if (!has_stack_frames ())
6449 if (last.kind == TARGET_WAITKIND_SIGNALLED
6450 || last.kind == TARGET_WAITKIND_EXITED)
6453 /* Select innermost stack frame - i.e., current frame is frame 0,
6454 and current location is based on that.
6455 Don't do this on return from a stack dummy routine,
6456 or if the program has exited. */
6458 if (!stop_stack_dummy)
6460 select_frame (get_current_frame ());
6462 /* If --batch-silent is enabled then there's no need to print the current
6463 source location, and to try risks causing an error message about
6464 missing source files. */
6465 if (stop_print_frame && !batch_silent)
6466 print_stop_event (&last);
6469 /* Save the function value return registers, if we care.
6470 We might be about to restore their previous contents. */
6471 if (inferior_thread ()->control.proceed_to_finish
6472 && execution_direction != EXEC_REVERSE)
6474 /* This should not be necessary. */
6476 regcache_xfree (stop_registers);
6478 /* NB: The copy goes through to the target picking up the value of
6479 all the registers. */
6480 stop_registers = regcache_dup (get_current_regcache ());
6483 if (stop_stack_dummy == STOP_STACK_DUMMY)
6485 /* Pop the empty frame that contains the stack dummy.
6486 This also restores inferior state prior to the call
6487 (struct infcall_suspend_state). */
6488 struct frame_info *frame = get_current_frame ();
6490 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6492 /* frame_pop() calls reinit_frame_cache as the last thing it
6493 does which means there's currently no selected frame. We
6494 don't need to re-establish a selected frame if the dummy call
6495 returns normally, that will be done by
6496 restore_infcall_control_state. However, we do have to handle
6497 the case where the dummy call is returning after being
6498 stopped (e.g. the dummy call previously hit a breakpoint).
6499 We can't know which case we have so just always re-establish
6500 a selected frame here. */
6501 select_frame (get_current_frame ());
6505 annotate_stopped ();
6507 /* Suppress the stop observer if we're in the middle of:
6509 - a step n (n > 1), as there still more steps to be done.
6511 - a "finish" command, as the observer will be called in
6512 finish_command_continuation, so it can include the inferior
6513 function's return value.
6515 - calling an inferior function, as we pretend we inferior didn't
6516 run at all. The return value of the call is handled by the
6517 expression evaluator, through call_function_by_hand. */
6519 if (!target_has_execution
6520 || last.kind == TARGET_WAITKIND_SIGNALLED
6521 || last.kind == TARGET_WAITKIND_EXITED
6522 || last.kind == TARGET_WAITKIND_NO_RESUMED
6523 || (!(inferior_thread ()->step_multi
6524 && inferior_thread ()->control.stop_step)
6525 && !(inferior_thread ()->control.stop_bpstat
6526 && inferior_thread ()->control.proceed_to_finish)
6527 && !inferior_thread ()->control.in_infcall))
6529 if (!ptid_equal (inferior_ptid, null_ptid))
6530 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6533 observer_notify_normal_stop (NULL, stop_print_frame);
6536 if (target_has_execution)
6538 if (last.kind != TARGET_WAITKIND_SIGNALLED
6539 && last.kind != TARGET_WAITKIND_EXITED)
6540 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6541 Delete any breakpoint that is to be deleted at the next stop. */
6542 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6545 /* Try to get rid of automatically added inferiors that are no
6546 longer needed. Keeping those around slows down things linearly.
6547 Note that this never removes the current inferior. */
6552 hook_stop_stub (void *cmd)
6554 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6559 signal_stop_state (int signo)
6561 return signal_stop[signo];
6565 signal_print_state (int signo)
6567 return signal_print[signo];
6571 signal_pass_state (int signo)
6573 return signal_program[signo];
6577 signal_cache_update (int signo)
6581 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6582 signal_cache_update (signo);
6587 signal_pass[signo] = (signal_stop[signo] == 0
6588 && signal_print[signo] == 0
6589 && signal_program[signo] == 1
6590 && signal_catch[signo] == 0);
6594 signal_stop_update (int signo, int state)
6596 int ret = signal_stop[signo];
6598 signal_stop[signo] = state;
6599 signal_cache_update (signo);
6604 signal_print_update (int signo, int state)
6606 int ret = signal_print[signo];
6608 signal_print[signo] = state;
6609 signal_cache_update (signo);
6614 signal_pass_update (int signo, int state)
6616 int ret = signal_program[signo];
6618 signal_program[signo] = state;
6619 signal_cache_update (signo);
6623 /* Update the global 'signal_catch' from INFO and notify the
6627 signal_catch_update (const unsigned int *info)
6631 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6632 signal_catch[i] = info[i] > 0;
6633 signal_cache_update (-1);
6634 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6638 sig_print_header (void)
6640 printf_filtered (_("Signal Stop\tPrint\tPass "
6641 "to program\tDescription\n"));
6645 sig_print_info (enum gdb_signal oursig)
6647 const char *name = gdb_signal_to_name (oursig);
6648 int name_padding = 13 - strlen (name);
6650 if (name_padding <= 0)
6653 printf_filtered ("%s", name);
6654 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6655 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6656 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6657 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6658 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6661 /* Specify how various signals in the inferior should be handled. */
6664 handle_command (char *args, int from_tty)
6667 int digits, wordlen;
6668 int sigfirst, signum, siglast;
6669 enum gdb_signal oursig;
6672 unsigned char *sigs;
6673 struct cleanup *old_chain;
6677 error_no_arg (_("signal to handle"));
6680 /* Allocate and zero an array of flags for which signals to handle. */
6682 nsigs = (int) GDB_SIGNAL_LAST;
6683 sigs = (unsigned char *) alloca (nsigs);
6684 memset (sigs, 0, nsigs);
6686 /* Break the command line up into args. */
6688 argv = gdb_buildargv (args);
6689 old_chain = make_cleanup_freeargv (argv);
6691 /* Walk through the args, looking for signal oursigs, signal names, and
6692 actions. Signal numbers and signal names may be interspersed with
6693 actions, with the actions being performed for all signals cumulatively
6694 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6696 while (*argv != NULL)
6698 wordlen = strlen (*argv);
6699 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6703 sigfirst = siglast = -1;
6705 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6707 /* Apply action to all signals except those used by the
6708 debugger. Silently skip those. */
6711 siglast = nsigs - 1;
6713 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6715 SET_SIGS (nsigs, sigs, signal_stop);
6716 SET_SIGS (nsigs, sigs, signal_print);
6718 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6720 UNSET_SIGS (nsigs, sigs, signal_program);
6722 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6724 SET_SIGS (nsigs, sigs, signal_print);
6726 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6728 SET_SIGS (nsigs, sigs, signal_program);
6730 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6732 UNSET_SIGS (nsigs, sigs, signal_stop);
6734 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6736 SET_SIGS (nsigs, sigs, signal_program);
6738 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6740 UNSET_SIGS (nsigs, sigs, signal_print);
6741 UNSET_SIGS (nsigs, sigs, signal_stop);
6743 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6745 UNSET_SIGS (nsigs, sigs, signal_program);
6747 else if (digits > 0)
6749 /* It is numeric. The numeric signal refers to our own
6750 internal signal numbering from target.h, not to host/target
6751 signal number. This is a feature; users really should be
6752 using symbolic names anyway, and the common ones like
6753 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6755 sigfirst = siglast = (int)
6756 gdb_signal_from_command (atoi (*argv));
6757 if ((*argv)[digits] == '-')
6760 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6762 if (sigfirst > siglast)
6764 /* Bet he didn't figure we'd think of this case... */
6772 oursig = gdb_signal_from_name (*argv);
6773 if (oursig != GDB_SIGNAL_UNKNOWN)
6775 sigfirst = siglast = (int) oursig;
6779 /* Not a number and not a recognized flag word => complain. */
6780 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6784 /* If any signal numbers or symbol names were found, set flags for
6785 which signals to apply actions to. */
6787 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6789 switch ((enum gdb_signal) signum)
6791 case GDB_SIGNAL_TRAP:
6792 case GDB_SIGNAL_INT:
6793 if (!allsigs && !sigs[signum])
6795 if (query (_("%s is used by the debugger.\n\
6796 Are you sure you want to change it? "),
6797 gdb_signal_to_name ((enum gdb_signal) signum)))
6803 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6804 gdb_flush (gdb_stdout);
6809 case GDB_SIGNAL_DEFAULT:
6810 case GDB_SIGNAL_UNKNOWN:
6811 /* Make sure that "all" doesn't print these. */
6822 for (signum = 0; signum < nsigs; signum++)
6825 signal_cache_update (-1);
6826 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6827 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
6831 /* Show the results. */
6832 sig_print_header ();
6833 for (; signum < nsigs; signum++)
6835 sig_print_info (signum);
6841 do_cleanups (old_chain);
6844 /* Complete the "handle" command. */
6846 static VEC (char_ptr) *
6847 handle_completer (struct cmd_list_element *ignore,
6848 const char *text, const char *word)
6850 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
6851 static const char * const keywords[] =
6865 vec_signals = signal_completer (ignore, text, word);
6866 vec_keywords = complete_on_enum (keywords, word, word);
6868 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
6869 VEC_free (char_ptr, vec_signals);
6870 VEC_free (char_ptr, vec_keywords);
6875 xdb_handle_command (char *args, int from_tty)
6878 struct cleanup *old_chain;
6881 error_no_arg (_("xdb command"));
6883 /* Break the command line up into args. */
6885 argv = gdb_buildargv (args);
6886 old_chain = make_cleanup_freeargv (argv);
6887 if (argv[1] != (char *) NULL)
6892 bufLen = strlen (argv[0]) + 20;
6893 argBuf = (char *) xmalloc (bufLen);
6897 enum gdb_signal oursig;
6899 oursig = gdb_signal_from_name (argv[0]);
6900 memset (argBuf, 0, bufLen);
6901 if (strcmp (argv[1], "Q") == 0)
6902 sprintf (argBuf, "%s %s", argv[0], "noprint");
6905 if (strcmp (argv[1], "s") == 0)
6907 if (!signal_stop[oursig])
6908 sprintf (argBuf, "%s %s", argv[0], "stop");
6910 sprintf (argBuf, "%s %s", argv[0], "nostop");
6912 else if (strcmp (argv[1], "i") == 0)
6914 if (!signal_program[oursig])
6915 sprintf (argBuf, "%s %s", argv[0], "pass");
6917 sprintf (argBuf, "%s %s", argv[0], "nopass");
6919 else if (strcmp (argv[1], "r") == 0)
6921 if (!signal_print[oursig])
6922 sprintf (argBuf, "%s %s", argv[0], "print");
6924 sprintf (argBuf, "%s %s", argv[0], "noprint");
6930 handle_command (argBuf, from_tty);
6932 printf_filtered (_("Invalid signal handling flag.\n"));
6937 do_cleanups (old_chain);
6941 gdb_signal_from_command (int num)
6943 if (num >= 1 && num <= 15)
6944 return (enum gdb_signal) num;
6945 error (_("Only signals 1-15 are valid as numeric signals.\n\
6946 Use \"info signals\" for a list of symbolic signals."));
6949 /* Print current contents of the tables set by the handle command.
6950 It is possible we should just be printing signals actually used
6951 by the current target (but for things to work right when switching
6952 targets, all signals should be in the signal tables). */
6955 signals_info (char *signum_exp, int from_tty)
6957 enum gdb_signal oursig;
6959 sig_print_header ();
6963 /* First see if this is a symbol name. */
6964 oursig = gdb_signal_from_name (signum_exp);
6965 if (oursig == GDB_SIGNAL_UNKNOWN)
6967 /* No, try numeric. */
6969 gdb_signal_from_command (parse_and_eval_long (signum_exp));
6971 sig_print_info (oursig);
6975 printf_filtered ("\n");
6976 /* These ugly casts brought to you by the native VAX compiler. */
6977 for (oursig = GDB_SIGNAL_FIRST;
6978 (int) oursig < (int) GDB_SIGNAL_LAST;
6979 oursig = (enum gdb_signal) ((int) oursig + 1))
6983 if (oursig != GDB_SIGNAL_UNKNOWN
6984 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
6985 sig_print_info (oursig);
6988 printf_filtered (_("\nUse the \"handle\" command "
6989 "to change these tables.\n"));
6992 /* Check if it makes sense to read $_siginfo from the current thread
6993 at this point. If not, throw an error. */
6996 validate_siginfo_access (void)
6998 /* No current inferior, no siginfo. */
6999 if (ptid_equal (inferior_ptid, null_ptid))
7000 error (_("No thread selected."));
7002 /* Don't try to read from a dead thread. */
7003 if (is_exited (inferior_ptid))
7004 error (_("The current thread has terminated"));
7006 /* ... or from a spinning thread. */
7007 if (is_running (inferior_ptid))
7008 error (_("Selected thread is running."));
7011 /* The $_siginfo convenience variable is a bit special. We don't know
7012 for sure the type of the value until we actually have a chance to
7013 fetch the data. The type can change depending on gdbarch, so it is
7014 also dependent on which thread you have selected.
7016 1. making $_siginfo be an internalvar that creates a new value on
7019 2. making the value of $_siginfo be an lval_computed value. */
7021 /* This function implements the lval_computed support for reading a
7025 siginfo_value_read (struct value *v)
7027 LONGEST transferred;
7029 validate_siginfo_access ();
7032 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
7034 value_contents_all_raw (v),
7036 TYPE_LENGTH (value_type (v)));
7038 if (transferred != TYPE_LENGTH (value_type (v)))
7039 error (_("Unable to read siginfo"));
7042 /* This function implements the lval_computed support for writing a
7046 siginfo_value_write (struct value *v, struct value *fromval)
7048 LONGEST transferred;
7050 validate_siginfo_access ();
7052 transferred = target_write (¤t_target,
7053 TARGET_OBJECT_SIGNAL_INFO,
7055 value_contents_all_raw (fromval),
7057 TYPE_LENGTH (value_type (fromval)));
7059 if (transferred != TYPE_LENGTH (value_type (fromval)))
7060 error (_("Unable to write siginfo"));
7063 static const struct lval_funcs siginfo_value_funcs =
7069 /* Return a new value with the correct type for the siginfo object of
7070 the current thread using architecture GDBARCH. Return a void value
7071 if there's no object available. */
7073 static struct value *
7074 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
7077 if (target_has_stack
7078 && !ptid_equal (inferior_ptid, null_ptid)
7079 && gdbarch_get_siginfo_type_p (gdbarch))
7081 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7083 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
7086 return allocate_value (builtin_type (gdbarch)->builtin_void);
7090 /* infcall_suspend_state contains state about the program itself like its
7091 registers and any signal it received when it last stopped.
7092 This state must be restored regardless of how the inferior function call
7093 ends (either successfully, or after it hits a breakpoint or signal)
7094 if the program is to properly continue where it left off. */
7096 struct infcall_suspend_state
7098 struct thread_suspend_state thread_suspend;
7099 #if 0 /* Currently unused and empty structures are not valid C. */
7100 struct inferior_suspend_state inferior_suspend;
7105 struct regcache *registers;
7107 /* Format of SIGINFO_DATA or NULL if it is not present. */
7108 struct gdbarch *siginfo_gdbarch;
7110 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
7111 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
7112 content would be invalid. */
7113 gdb_byte *siginfo_data;
7116 struct infcall_suspend_state *
7117 save_infcall_suspend_state (void)
7119 struct infcall_suspend_state *inf_state;
7120 struct thread_info *tp = inferior_thread ();
7122 struct inferior *inf = current_inferior ();
7124 struct regcache *regcache = get_current_regcache ();
7125 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7126 gdb_byte *siginfo_data = NULL;
7128 if (gdbarch_get_siginfo_type_p (gdbarch))
7130 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7131 size_t len = TYPE_LENGTH (type);
7132 struct cleanup *back_to;
7134 siginfo_data = xmalloc (len);
7135 back_to = make_cleanup (xfree, siginfo_data);
7137 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
7138 siginfo_data, 0, len) == len)
7139 discard_cleanups (back_to);
7142 /* Errors ignored. */
7143 do_cleanups (back_to);
7144 siginfo_data = NULL;
7148 inf_state = XCNEW (struct infcall_suspend_state);
7152 inf_state->siginfo_gdbarch = gdbarch;
7153 inf_state->siginfo_data = siginfo_data;
7156 inf_state->thread_suspend = tp->suspend;
7157 #if 0 /* Currently unused and empty structures are not valid C. */
7158 inf_state->inferior_suspend = inf->suspend;
7161 /* run_inferior_call will not use the signal due to its `proceed' call with
7162 GDB_SIGNAL_0 anyway. */
7163 tp->suspend.stop_signal = GDB_SIGNAL_0;
7165 inf_state->stop_pc = stop_pc;
7167 inf_state->registers = regcache_dup (regcache);
7172 /* Restore inferior session state to INF_STATE. */
7175 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
7177 struct thread_info *tp = inferior_thread ();
7179 struct inferior *inf = current_inferior ();
7181 struct regcache *regcache = get_current_regcache ();
7182 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7184 tp->suspend = inf_state->thread_suspend;
7185 #if 0 /* Currently unused and empty structures are not valid C. */
7186 inf->suspend = inf_state->inferior_suspend;
7189 stop_pc = inf_state->stop_pc;
7191 if (inf_state->siginfo_gdbarch == gdbarch)
7193 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7195 /* Errors ignored. */
7196 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
7197 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
7200 /* The inferior can be gone if the user types "print exit(0)"
7201 (and perhaps other times). */
7202 if (target_has_execution)
7203 /* NB: The register write goes through to the target. */
7204 regcache_cpy (regcache, inf_state->registers);
7206 discard_infcall_suspend_state (inf_state);
7210 do_restore_infcall_suspend_state_cleanup (void *state)
7212 restore_infcall_suspend_state (state);
7216 make_cleanup_restore_infcall_suspend_state
7217 (struct infcall_suspend_state *inf_state)
7219 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
7223 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
7225 regcache_xfree (inf_state->registers);
7226 xfree (inf_state->siginfo_data);
7231 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
7233 return inf_state->registers;
7236 /* infcall_control_state contains state regarding gdb's control of the
7237 inferior itself like stepping control. It also contains session state like
7238 the user's currently selected frame. */
7240 struct infcall_control_state
7242 struct thread_control_state thread_control;
7243 struct inferior_control_state inferior_control;
7246 enum stop_stack_kind stop_stack_dummy;
7247 int stopped_by_random_signal;
7248 int stop_after_trap;
7250 /* ID if the selected frame when the inferior function call was made. */
7251 struct frame_id selected_frame_id;
7254 /* Save all of the information associated with the inferior<==>gdb
7257 struct infcall_control_state *
7258 save_infcall_control_state (void)
7260 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
7261 struct thread_info *tp = inferior_thread ();
7262 struct inferior *inf = current_inferior ();
7264 inf_status->thread_control = tp->control;
7265 inf_status->inferior_control = inf->control;
7267 tp->control.step_resume_breakpoint = NULL;
7268 tp->control.exception_resume_breakpoint = NULL;
7270 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
7271 chain. If caller's caller is walking the chain, they'll be happier if we
7272 hand them back the original chain when restore_infcall_control_state is
7274 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
7277 inf_status->stop_stack_dummy = stop_stack_dummy;
7278 inf_status->stopped_by_random_signal = stopped_by_random_signal;
7279 inf_status->stop_after_trap = stop_after_trap;
7281 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
7287 restore_selected_frame (void *args)
7289 struct frame_id *fid = (struct frame_id *) args;
7290 struct frame_info *frame;
7292 frame = frame_find_by_id (*fid);
7294 /* If inf_status->selected_frame_id is NULL, there was no previously
7298 warning (_("Unable to restore previously selected frame."));
7302 select_frame (frame);
7307 /* Restore inferior session state to INF_STATUS. */
7310 restore_infcall_control_state (struct infcall_control_state *inf_status)
7312 struct thread_info *tp = inferior_thread ();
7313 struct inferior *inf = current_inferior ();
7315 if (tp->control.step_resume_breakpoint)
7316 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
7318 if (tp->control.exception_resume_breakpoint)
7319 tp->control.exception_resume_breakpoint->disposition
7320 = disp_del_at_next_stop;
7322 /* Handle the bpstat_copy of the chain. */
7323 bpstat_clear (&tp->control.stop_bpstat);
7325 tp->control = inf_status->thread_control;
7326 inf->control = inf_status->inferior_control;
7329 stop_stack_dummy = inf_status->stop_stack_dummy;
7330 stopped_by_random_signal = inf_status->stopped_by_random_signal;
7331 stop_after_trap = inf_status->stop_after_trap;
7333 if (target_has_stack)
7335 /* The point of catch_errors is that if the stack is clobbered,
7336 walking the stack might encounter a garbage pointer and
7337 error() trying to dereference it. */
7339 (restore_selected_frame, &inf_status->selected_frame_id,
7340 "Unable to restore previously selected frame:\n",
7341 RETURN_MASK_ERROR) == 0)
7342 /* Error in restoring the selected frame. Select the innermost
7344 select_frame (get_current_frame ());
7351 do_restore_infcall_control_state_cleanup (void *sts)
7353 restore_infcall_control_state (sts);
7357 make_cleanup_restore_infcall_control_state
7358 (struct infcall_control_state *inf_status)
7360 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
7364 discard_infcall_control_state (struct infcall_control_state *inf_status)
7366 if (inf_status->thread_control.step_resume_breakpoint)
7367 inf_status->thread_control.step_resume_breakpoint->disposition
7368 = disp_del_at_next_stop;
7370 if (inf_status->thread_control.exception_resume_breakpoint)
7371 inf_status->thread_control.exception_resume_breakpoint->disposition
7372 = disp_del_at_next_stop;
7374 /* See save_infcall_control_state for info on stop_bpstat. */
7375 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7380 /* restore_inferior_ptid() will be used by the cleanup machinery
7381 to restore the inferior_ptid value saved in a call to
7382 save_inferior_ptid(). */
7385 restore_inferior_ptid (void *arg)
7387 ptid_t *saved_ptid_ptr = arg;
7389 inferior_ptid = *saved_ptid_ptr;
7393 /* Save the value of inferior_ptid so that it may be restored by a
7394 later call to do_cleanups(). Returns the struct cleanup pointer
7395 needed for later doing the cleanup. */
7398 save_inferior_ptid (void)
7400 ptid_t *saved_ptid_ptr;
7402 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7403 *saved_ptid_ptr = inferior_ptid;
7404 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7410 clear_exit_convenience_vars (void)
7412 clear_internalvar (lookup_internalvar ("_exitsignal"));
7413 clear_internalvar (lookup_internalvar ("_exitcode"));
7417 /* User interface for reverse debugging:
7418 Set exec-direction / show exec-direction commands
7419 (returns error unless target implements to_set_exec_direction method). */
7421 int execution_direction = EXEC_FORWARD;
7422 static const char exec_forward[] = "forward";
7423 static const char exec_reverse[] = "reverse";
7424 static const char *exec_direction = exec_forward;
7425 static const char *const exec_direction_names[] = {
7432 set_exec_direction_func (char *args, int from_tty,
7433 struct cmd_list_element *cmd)
7435 if (target_can_execute_reverse)
7437 if (!strcmp (exec_direction, exec_forward))
7438 execution_direction = EXEC_FORWARD;
7439 else if (!strcmp (exec_direction, exec_reverse))
7440 execution_direction = EXEC_REVERSE;
7444 exec_direction = exec_forward;
7445 error (_("Target does not support this operation."));
7450 show_exec_direction_func (struct ui_file *out, int from_tty,
7451 struct cmd_list_element *cmd, const char *value)
7453 switch (execution_direction) {
7455 fprintf_filtered (out, _("Forward.\n"));
7458 fprintf_filtered (out, _("Reverse.\n"));
7461 internal_error (__FILE__, __LINE__,
7462 _("bogus execution_direction value: %d"),
7463 (int) execution_direction);
7468 show_schedule_multiple (struct ui_file *file, int from_tty,
7469 struct cmd_list_element *c, const char *value)
7471 fprintf_filtered (file, _("Resuming the execution of threads "
7472 "of all processes is %s.\n"), value);
7475 /* Implementation of `siginfo' variable. */
7477 static const struct internalvar_funcs siginfo_funcs =
7485 _initialize_infrun (void)
7489 struct cmd_list_element *c;
7491 add_info ("signals", signals_info, _("\
7492 What debugger does when program gets various signals.\n\
7493 Specify a signal as argument to print info on that signal only."));
7494 add_info_alias ("handle", "signals", 0);
7496 c = add_com ("handle", class_run, handle_command, _("\
7497 Specify how to handle signals.\n\
7498 Usage: handle SIGNAL [ACTIONS]\n\
7499 Args are signals and actions to apply to those signals.\n\
7500 If no actions are specified, the current settings for the specified signals\n\
7501 will be displayed instead.\n\
7503 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7504 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7505 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7506 The special arg \"all\" is recognized to mean all signals except those\n\
7507 used by the debugger, typically SIGTRAP and SIGINT.\n\
7509 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7510 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7511 Stop means reenter debugger if this signal happens (implies print).\n\
7512 Print means print a message if this signal happens.\n\
7513 Pass means let program see this signal; otherwise program doesn't know.\n\
7514 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7515 Pass and Stop may be combined.\n\
7517 Multiple signals may be specified. Signal numbers and signal names\n\
7518 may be interspersed with actions, with the actions being performed for\n\
7519 all signals cumulatively specified."));
7520 set_cmd_completer (c, handle_completer);
7524 add_com ("lz", class_info, signals_info, _("\
7525 What debugger does when program gets various signals.\n\
7526 Specify a signal as argument to print info on that signal only."));
7527 add_com ("z", class_run, xdb_handle_command, _("\
7528 Specify how to handle a signal.\n\
7529 Args are signals and actions to apply to those signals.\n\
7530 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7531 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7532 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7533 The special arg \"all\" is recognized to mean all signals except those\n\
7534 used by the debugger, typically SIGTRAP and SIGINT.\n\
7535 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7536 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7537 nopass), \"Q\" (noprint)\n\
7538 Stop means reenter debugger if this signal happens (implies print).\n\
7539 Print means print a message if this signal happens.\n\
7540 Pass means let program see this signal; otherwise program doesn't know.\n\
7541 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7542 Pass and Stop may be combined."));
7546 stop_command = add_cmd ("stop", class_obscure,
7547 not_just_help_class_command, _("\
7548 There is no `stop' command, but you can set a hook on `stop'.\n\
7549 This allows you to set a list of commands to be run each time execution\n\
7550 of the program stops."), &cmdlist);
7552 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7553 Set inferior debugging."), _("\
7554 Show inferior debugging."), _("\
7555 When non-zero, inferior specific debugging is enabled."),
7558 &setdebuglist, &showdebuglist);
7560 add_setshow_boolean_cmd ("displaced", class_maintenance,
7561 &debug_displaced, _("\
7562 Set displaced stepping debugging."), _("\
7563 Show displaced stepping debugging."), _("\
7564 When non-zero, displaced stepping specific debugging is enabled."),
7566 show_debug_displaced,
7567 &setdebuglist, &showdebuglist);
7569 add_setshow_boolean_cmd ("non-stop", no_class,
7571 Set whether gdb controls the inferior in non-stop mode."), _("\
7572 Show whether gdb controls the inferior in non-stop mode."), _("\
7573 When debugging a multi-threaded program and this setting is\n\
7574 off (the default, also called all-stop mode), when one thread stops\n\
7575 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7576 all other threads in the program while you interact with the thread of\n\
7577 interest. When you continue or step a thread, you can allow the other\n\
7578 threads to run, or have them remain stopped, but while you inspect any\n\
7579 thread's state, all threads stop.\n\
7581 In non-stop mode, when one thread stops, other threads can continue\n\
7582 to run freely. You'll be able to step each thread independently,\n\
7583 leave it stopped or free to run as needed."),
7589 numsigs = (int) GDB_SIGNAL_LAST;
7590 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7591 signal_print = (unsigned char *)
7592 xmalloc (sizeof (signal_print[0]) * numsigs);
7593 signal_program = (unsigned char *)
7594 xmalloc (sizeof (signal_program[0]) * numsigs);
7595 signal_catch = (unsigned char *)
7596 xmalloc (sizeof (signal_catch[0]) * numsigs);
7597 signal_pass = (unsigned char *)
7598 xmalloc (sizeof (signal_pass[0]) * numsigs);
7599 for (i = 0; i < numsigs; i++)
7602 signal_print[i] = 1;
7603 signal_program[i] = 1;
7604 signal_catch[i] = 0;
7607 /* Signals caused by debugger's own actions
7608 should not be given to the program afterwards. */
7609 signal_program[GDB_SIGNAL_TRAP] = 0;
7610 signal_program[GDB_SIGNAL_INT] = 0;
7612 /* Signals that are not errors should not normally enter the debugger. */
7613 signal_stop[GDB_SIGNAL_ALRM] = 0;
7614 signal_print[GDB_SIGNAL_ALRM] = 0;
7615 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7616 signal_print[GDB_SIGNAL_VTALRM] = 0;
7617 signal_stop[GDB_SIGNAL_PROF] = 0;
7618 signal_print[GDB_SIGNAL_PROF] = 0;
7619 signal_stop[GDB_SIGNAL_CHLD] = 0;
7620 signal_print[GDB_SIGNAL_CHLD] = 0;
7621 signal_stop[GDB_SIGNAL_IO] = 0;
7622 signal_print[GDB_SIGNAL_IO] = 0;
7623 signal_stop[GDB_SIGNAL_POLL] = 0;
7624 signal_print[GDB_SIGNAL_POLL] = 0;
7625 signal_stop[GDB_SIGNAL_URG] = 0;
7626 signal_print[GDB_SIGNAL_URG] = 0;
7627 signal_stop[GDB_SIGNAL_WINCH] = 0;
7628 signal_print[GDB_SIGNAL_WINCH] = 0;
7629 signal_stop[GDB_SIGNAL_PRIO] = 0;
7630 signal_print[GDB_SIGNAL_PRIO] = 0;
7632 /* These signals are used internally by user-level thread
7633 implementations. (See signal(5) on Solaris.) Like the above
7634 signals, a healthy program receives and handles them as part of
7635 its normal operation. */
7636 signal_stop[GDB_SIGNAL_LWP] = 0;
7637 signal_print[GDB_SIGNAL_LWP] = 0;
7638 signal_stop[GDB_SIGNAL_WAITING] = 0;
7639 signal_print[GDB_SIGNAL_WAITING] = 0;
7640 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7641 signal_print[GDB_SIGNAL_CANCEL] = 0;
7643 /* Update cached state. */
7644 signal_cache_update (-1);
7646 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7647 &stop_on_solib_events, _("\
7648 Set stopping for shared library events."), _("\
7649 Show stopping for shared library events."), _("\
7650 If nonzero, gdb will give control to the user when the dynamic linker\n\
7651 notifies gdb of shared library events. The most common event of interest\n\
7652 to the user would be loading/unloading of a new library."),
7653 set_stop_on_solib_events,
7654 show_stop_on_solib_events,
7655 &setlist, &showlist);
7657 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7658 follow_fork_mode_kind_names,
7659 &follow_fork_mode_string, _("\
7660 Set debugger response to a program call of fork or vfork."), _("\
7661 Show debugger response to a program call of fork or vfork."), _("\
7662 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7663 parent - the original process is debugged after a fork\n\
7664 child - the new process is debugged after a fork\n\
7665 The unfollowed process will continue to run.\n\
7666 By default, the debugger will follow the parent process."),
7668 show_follow_fork_mode_string,
7669 &setlist, &showlist);
7671 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7672 follow_exec_mode_names,
7673 &follow_exec_mode_string, _("\
7674 Set debugger response to a program call of exec."), _("\
7675 Show debugger response to a program call of exec."), _("\
7676 An exec call replaces the program image of a process.\n\
7678 follow-exec-mode can be:\n\
7680 new - the debugger creates a new inferior and rebinds the process\n\
7681 to this new inferior. The program the process was running before\n\
7682 the exec call can be restarted afterwards by restarting the original\n\
7685 same - the debugger keeps the process bound to the same inferior.\n\
7686 The new executable image replaces the previous executable loaded in\n\
7687 the inferior. Restarting the inferior after the exec call restarts\n\
7688 the executable the process was running after the exec call.\n\
7690 By default, the debugger will use the same inferior."),
7692 show_follow_exec_mode_string,
7693 &setlist, &showlist);
7695 add_setshow_enum_cmd ("scheduler-locking", class_run,
7696 scheduler_enums, &scheduler_mode, _("\
7697 Set mode for locking scheduler during execution."), _("\
7698 Show mode for locking scheduler during execution."), _("\
7699 off == no locking (threads may preempt at any time)\n\
7700 on == full locking (no thread except the current thread may run)\n\
7701 step == scheduler locked during every single-step operation.\n\
7702 In this mode, no other thread may run during a step command.\n\
7703 Other threads may run while stepping over a function call ('next')."),
7704 set_schedlock_func, /* traps on target vector */
7705 show_scheduler_mode,
7706 &setlist, &showlist);
7708 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7709 Set mode for resuming threads of all processes."), _("\
7710 Show mode for resuming threads of all processes."), _("\
7711 When on, execution commands (such as 'continue' or 'next') resume all\n\
7712 threads of all processes. When off (which is the default), execution\n\
7713 commands only resume the threads of the current process. The set of\n\
7714 threads that are resumed is further refined by the scheduler-locking\n\
7715 mode (see help set scheduler-locking)."),
7717 show_schedule_multiple,
7718 &setlist, &showlist);
7720 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7721 Set mode of the step operation."), _("\
7722 Show mode of the step operation."), _("\
7723 When set, doing a step over a function without debug line information\n\
7724 will stop at the first instruction of that function. Otherwise, the\n\
7725 function is skipped and the step command stops at a different source line."),
7727 show_step_stop_if_no_debug,
7728 &setlist, &showlist);
7730 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7731 &can_use_displaced_stepping, _("\
7732 Set debugger's willingness to use displaced stepping."), _("\
7733 Show debugger's willingness to use displaced stepping."), _("\
7734 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7735 supported by the target architecture. If off, gdb will not use displaced\n\
7736 stepping to step over breakpoints, even if such is supported by the target\n\
7737 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7738 if the target architecture supports it and non-stop mode is active, but will not\n\
7739 use it in all-stop mode (see help set non-stop)."),
7741 show_can_use_displaced_stepping,
7742 &setlist, &showlist);
7744 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7745 &exec_direction, _("Set direction of execution.\n\
7746 Options are 'forward' or 'reverse'."),
7747 _("Show direction of execution (forward/reverse)."),
7748 _("Tells gdb whether to execute forward or backward."),
7749 set_exec_direction_func, show_exec_direction_func,
7750 &setlist, &showlist);
7752 /* Set/show detach-on-fork: user-settable mode. */
7754 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7755 Set whether gdb will detach the child of a fork."), _("\
7756 Show whether gdb will detach the child of a fork."), _("\
7757 Tells gdb whether to detach the child of a fork."),
7758 NULL, NULL, &setlist, &showlist);
7760 /* Set/show disable address space randomization mode. */
7762 add_setshow_boolean_cmd ("disable-randomization", class_support,
7763 &disable_randomization, _("\
7764 Set disabling of debuggee's virtual address space randomization."), _("\
7765 Show disabling of debuggee's virtual address space randomization."), _("\
7766 When this mode is on (which is the default), randomization of the virtual\n\
7767 address space is disabled. Standalone programs run with the randomization\n\
7768 enabled by default on some platforms."),
7769 &set_disable_randomization,
7770 &show_disable_randomization,
7771 &setlist, &showlist);
7773 /* ptid initializations */
7774 inferior_ptid = null_ptid;
7775 target_last_wait_ptid = minus_one_ptid;
7777 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7778 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7779 observer_attach_thread_exit (infrun_thread_thread_exit);
7780 observer_attach_inferior_exit (infrun_inferior_exit);
7782 /* Explicitly create without lookup, since that tries to create a
7783 value with a void typed value, and when we get here, gdbarch
7784 isn't initialized yet. At this point, we're quite sure there
7785 isn't another convenience variable of the same name. */
7786 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7788 add_setshow_boolean_cmd ("observer", no_class,
7789 &observer_mode_1, _("\
7790 Set whether gdb controls the inferior in observer mode."), _("\
7791 Show whether gdb controls the inferior in observer mode."), _("\
7792 In observer mode, GDB can get data from the inferior, but not\n\
7793 affect its execution. Registers and memory may not be changed,\n\
7794 breakpoints may not be set, and the program cannot be interrupted\n\