1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2015 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 /* 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 /* Nonzero if we want to give control to the user when we're notified
330 of shared library events by the dynamic linker. */
331 int stop_on_solib_events;
333 /* Enable or disable optional shared library event breakpoints
334 as appropriate when the above flag is changed. */
337 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
339 update_solib_breakpoints ();
343 show_stop_on_solib_events (struct ui_file *file, int from_tty,
344 struct cmd_list_element *c, const char *value)
346 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
350 /* Nonzero means expecting a trace trap
351 and should stop the inferior and return silently when it happens. */
355 /* Save register contents here when executing a "finish" command or are
356 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
357 Thus this contains the return value from the called function (assuming
358 values are returned in a register). */
360 struct regcache *stop_registers;
362 /* Nonzero after stop if current stack frame should be printed. */
364 static int stop_print_frame;
366 /* This is a cached copy of the pid/waitstatus of the last event
367 returned by target_wait()/deprecated_target_wait_hook(). This
368 information is returned by get_last_target_status(). */
369 static ptid_t target_last_wait_ptid;
370 static struct target_waitstatus target_last_waitstatus;
372 static void context_switch (ptid_t ptid);
374 void init_thread_stepping_state (struct thread_info *tss);
376 static const char follow_fork_mode_child[] = "child";
377 static const char follow_fork_mode_parent[] = "parent";
379 static const char *const follow_fork_mode_kind_names[] = {
380 follow_fork_mode_child,
381 follow_fork_mode_parent,
385 static const char *follow_fork_mode_string = follow_fork_mode_parent;
387 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
388 struct cmd_list_element *c, const char *value)
390 fprintf_filtered (file,
391 _("Debugger response to a program "
392 "call of fork or vfork is \"%s\".\n"),
397 /* Handle changes to the inferior list based on the type of fork,
398 which process is being followed, and whether the other process
399 should be detached. On entry inferior_ptid must be the ptid of
400 the fork parent. At return inferior_ptid is the ptid of the
401 followed inferior. */
404 follow_fork_inferior (int follow_child, int detach_fork)
407 ptid_t parent_ptid, child_ptid;
409 has_vforked = (inferior_thread ()->pending_follow.kind
410 == TARGET_WAITKIND_VFORKED);
411 parent_ptid = inferior_ptid;
412 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
415 && !non_stop /* Non-stop always resumes both branches. */
416 && (!target_is_async_p () || sync_execution)
417 && !(follow_child || detach_fork || sched_multi))
419 /* The parent stays blocked inside the vfork syscall until the
420 child execs or exits. If we don't let the child run, then
421 the parent stays blocked. If we're telling the parent to run
422 in the foreground, the user will not be able to ctrl-c to get
423 back the terminal, effectively hanging the debug session. */
424 fprintf_filtered (gdb_stderr, _("\
425 Can not resume the parent process over vfork in the foreground while\n\
426 holding the child stopped. Try \"set detach-on-fork\" or \
427 \"set schedule-multiple\".\n"));
428 /* FIXME output string > 80 columns. */
434 /* Detach new forked process? */
437 struct cleanup *old_chain;
439 /* Before detaching from the child, remove all breakpoints
440 from it. If we forked, then this has already been taken
441 care of by infrun.c. If we vforked however, any
442 breakpoint inserted in the parent is visible in the
443 child, even those added while stopped in a vfork
444 catchpoint. This will remove the breakpoints from the
445 parent also, but they'll be reinserted below. */
448 /* Keep breakpoints list in sync. */
449 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
452 if (info_verbose || debug_infrun)
454 target_terminal_ours_for_output ();
455 fprintf_filtered (gdb_stdlog,
456 _("Detaching after %s from child %s.\n"),
457 has_vforked ? "vfork" : "fork",
458 target_pid_to_str (child_ptid));
463 struct inferior *parent_inf, *child_inf;
464 struct cleanup *old_chain;
466 /* Add process to GDB's tables. */
467 child_inf = add_inferior (ptid_get_pid (child_ptid));
469 parent_inf = current_inferior ();
470 child_inf->attach_flag = parent_inf->attach_flag;
471 copy_terminal_info (child_inf, parent_inf);
472 child_inf->gdbarch = parent_inf->gdbarch;
473 copy_inferior_target_desc_info (child_inf, parent_inf);
475 old_chain = save_inferior_ptid ();
476 save_current_program_space ();
478 inferior_ptid = child_ptid;
479 add_thread (inferior_ptid);
480 child_inf->symfile_flags = SYMFILE_NO_READ;
482 /* If this is a vfork child, then the address-space is
483 shared with the parent. */
486 child_inf->pspace = parent_inf->pspace;
487 child_inf->aspace = parent_inf->aspace;
489 /* The parent will be frozen until the child is done
490 with the shared region. Keep track of the
492 child_inf->vfork_parent = parent_inf;
493 child_inf->pending_detach = 0;
494 parent_inf->vfork_child = child_inf;
495 parent_inf->pending_detach = 0;
499 child_inf->aspace = new_address_space ();
500 child_inf->pspace = add_program_space (child_inf->aspace);
501 child_inf->removable = 1;
502 set_current_program_space (child_inf->pspace);
503 clone_program_space (child_inf->pspace, parent_inf->pspace);
505 /* Let the shared library layer (e.g., solib-svr4) learn
506 about this new process, relocate the cloned exec, pull
507 in shared libraries, and install the solib event
508 breakpoint. If a "cloned-VM" event was propagated
509 better throughout the core, this wouldn't be
511 solib_create_inferior_hook (0);
514 do_cleanups (old_chain);
519 struct inferior *parent_inf;
521 parent_inf = current_inferior ();
523 /* If we detached from the child, then we have to be careful
524 to not insert breakpoints in the parent until the child
525 is done with the shared memory region. However, if we're
526 staying attached to the child, then we can and should
527 insert breakpoints, so that we can debug it. A
528 subsequent child exec or exit is enough to know when does
529 the child stops using the parent's address space. */
530 parent_inf->waiting_for_vfork_done = detach_fork;
531 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
536 /* Follow the child. */
537 struct inferior *parent_inf, *child_inf;
538 struct program_space *parent_pspace;
540 if (info_verbose || debug_infrun)
542 target_terminal_ours_for_output ();
543 fprintf_filtered (gdb_stdlog,
544 _("Attaching after %s %s to child %s.\n"),
545 target_pid_to_str (parent_ptid),
546 has_vforked ? "vfork" : "fork",
547 target_pid_to_str (child_ptid));
550 /* Add the new inferior first, so that the target_detach below
551 doesn't unpush the target. */
553 child_inf = add_inferior (ptid_get_pid (child_ptid));
555 parent_inf = current_inferior ();
556 child_inf->attach_flag = parent_inf->attach_flag;
557 copy_terminal_info (child_inf, parent_inf);
558 child_inf->gdbarch = parent_inf->gdbarch;
559 copy_inferior_target_desc_info (child_inf, parent_inf);
561 parent_pspace = parent_inf->pspace;
563 /* If we're vforking, we want to hold on to the parent until the
564 child exits or execs. At child exec or exit time we can
565 remove the old breakpoints from the parent and detach or
566 resume debugging it. Otherwise, detach the parent now; we'll
567 want to reuse it's program/address spaces, but we can't set
568 them to the child before removing breakpoints from the
569 parent, otherwise, the breakpoints module could decide to
570 remove breakpoints from the wrong process (since they'd be
571 assigned to the same address space). */
575 gdb_assert (child_inf->vfork_parent == NULL);
576 gdb_assert (parent_inf->vfork_child == NULL);
577 child_inf->vfork_parent = parent_inf;
578 child_inf->pending_detach = 0;
579 parent_inf->vfork_child = child_inf;
580 parent_inf->pending_detach = detach_fork;
581 parent_inf->waiting_for_vfork_done = 0;
583 else if (detach_fork)
585 if (info_verbose || debug_infrun)
587 target_terminal_ours_for_output ();
588 fprintf_filtered (gdb_stdlog,
589 _("Detaching after fork from "
591 target_pid_to_str (child_ptid));
594 target_detach (NULL, 0);
597 /* Note that the detach above makes PARENT_INF dangling. */
599 /* Add the child thread to the appropriate lists, and switch to
600 this new thread, before cloning the program space, and
601 informing the solib layer about this new process. */
603 inferior_ptid = child_ptid;
604 add_thread (inferior_ptid);
606 /* If this is a vfork child, then the address-space is shared
607 with the parent. If we detached from the parent, then we can
608 reuse the parent's program/address spaces. */
609 if (has_vforked || detach_fork)
611 child_inf->pspace = parent_pspace;
612 child_inf->aspace = child_inf->pspace->aspace;
616 child_inf->aspace = new_address_space ();
617 child_inf->pspace = add_program_space (child_inf->aspace);
618 child_inf->removable = 1;
619 child_inf->symfile_flags = SYMFILE_NO_READ;
620 set_current_program_space (child_inf->pspace);
621 clone_program_space (child_inf->pspace, parent_pspace);
623 /* Let the shared library layer (e.g., solib-svr4) learn
624 about this new process, relocate the cloned exec, pull in
625 shared libraries, and install the solib event breakpoint.
626 If a "cloned-VM" event was propagated better throughout
627 the core, this wouldn't be required. */
628 solib_create_inferior_hook (0);
632 return target_follow_fork (follow_child, detach_fork);
635 /* Tell the target to follow the fork we're stopped at. Returns true
636 if the inferior should be resumed; false, if the target for some
637 reason decided it's best not to resume. */
642 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
643 int should_resume = 1;
644 struct thread_info *tp;
646 /* Copy user stepping state to the new inferior thread. FIXME: the
647 followed fork child thread should have a copy of most of the
648 parent thread structure's run control related fields, not just these.
649 Initialized to avoid "may be used uninitialized" warnings from gcc. */
650 struct breakpoint *step_resume_breakpoint = NULL;
651 struct breakpoint *exception_resume_breakpoint = NULL;
652 CORE_ADDR step_range_start = 0;
653 CORE_ADDR step_range_end = 0;
654 struct frame_id step_frame_id = { 0 };
655 struct interp *command_interp = NULL;
660 struct target_waitstatus wait_status;
662 /* Get the last target status returned by target_wait(). */
663 get_last_target_status (&wait_ptid, &wait_status);
665 /* If not stopped at a fork event, then there's nothing else to
667 if (wait_status.kind != TARGET_WAITKIND_FORKED
668 && wait_status.kind != TARGET_WAITKIND_VFORKED)
671 /* Check if we switched over from WAIT_PTID, since the event was
673 if (!ptid_equal (wait_ptid, minus_one_ptid)
674 && !ptid_equal (inferior_ptid, wait_ptid))
676 /* We did. Switch back to WAIT_PTID thread, to tell the
677 target to follow it (in either direction). We'll
678 afterwards refuse to resume, and inform the user what
680 switch_to_thread (wait_ptid);
685 tp = inferior_thread ();
687 /* If there were any forks/vforks that were caught and are now to be
688 followed, then do so now. */
689 switch (tp->pending_follow.kind)
691 case TARGET_WAITKIND_FORKED:
692 case TARGET_WAITKIND_VFORKED:
694 ptid_t parent, child;
696 /* If the user did a next/step, etc, over a fork call,
697 preserve the stepping state in the fork child. */
698 if (follow_child && should_resume)
700 step_resume_breakpoint = clone_momentary_breakpoint
701 (tp->control.step_resume_breakpoint);
702 step_range_start = tp->control.step_range_start;
703 step_range_end = tp->control.step_range_end;
704 step_frame_id = tp->control.step_frame_id;
705 exception_resume_breakpoint
706 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
707 command_interp = tp->control.command_interp;
709 /* For now, delete the parent's sr breakpoint, otherwise,
710 parent/child sr breakpoints are considered duplicates,
711 and the child version will not be installed. Remove
712 this when the breakpoints module becomes aware of
713 inferiors and address spaces. */
714 delete_step_resume_breakpoint (tp);
715 tp->control.step_range_start = 0;
716 tp->control.step_range_end = 0;
717 tp->control.step_frame_id = null_frame_id;
718 delete_exception_resume_breakpoint (tp);
719 tp->control.command_interp = NULL;
722 parent = inferior_ptid;
723 child = tp->pending_follow.value.related_pid;
725 /* Set up inferior(s) as specified by the caller, and tell the
726 target to do whatever is necessary to follow either parent
728 if (follow_fork_inferior (follow_child, detach_fork))
730 /* Target refused to follow, or there's some other reason
731 we shouldn't resume. */
736 /* This pending follow fork event is now handled, one way
737 or another. The previous selected thread may be gone
738 from the lists by now, but if it is still around, need
739 to clear the pending follow request. */
740 tp = find_thread_ptid (parent);
742 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
744 /* This makes sure we don't try to apply the "Switched
745 over from WAIT_PID" logic above. */
746 nullify_last_target_wait_ptid ();
748 /* If we followed the child, switch to it... */
751 switch_to_thread (child);
753 /* ... and preserve the stepping state, in case the
754 user was stepping over the fork call. */
757 tp = inferior_thread ();
758 tp->control.step_resume_breakpoint
759 = step_resume_breakpoint;
760 tp->control.step_range_start = step_range_start;
761 tp->control.step_range_end = step_range_end;
762 tp->control.step_frame_id = step_frame_id;
763 tp->control.exception_resume_breakpoint
764 = exception_resume_breakpoint;
765 tp->control.command_interp = command_interp;
769 /* If we get here, it was because we're trying to
770 resume from a fork catchpoint, but, the user
771 has switched threads away from the thread that
772 forked. In that case, the resume command
773 issued is most likely not applicable to the
774 child, so just warn, and refuse to resume. */
775 warning (_("Not resuming: switched threads "
776 "before following fork child.\n"));
779 /* Reset breakpoints in the child as appropriate. */
780 follow_inferior_reset_breakpoints ();
783 switch_to_thread (parent);
787 case TARGET_WAITKIND_SPURIOUS:
788 /* Nothing to follow. */
791 internal_error (__FILE__, __LINE__,
792 "Unexpected pending_follow.kind %d\n",
793 tp->pending_follow.kind);
797 return should_resume;
801 follow_inferior_reset_breakpoints (void)
803 struct thread_info *tp = inferior_thread ();
805 /* Was there a step_resume breakpoint? (There was if the user
806 did a "next" at the fork() call.) If so, explicitly reset its
807 thread number. Cloned step_resume breakpoints are disabled on
808 creation, so enable it here now that it is associated with the
811 step_resumes are a form of bp that are made to be per-thread.
812 Since we created the step_resume bp when the parent process
813 was being debugged, and now are switching to the child process,
814 from the breakpoint package's viewpoint, that's a switch of
815 "threads". We must update the bp's notion of which thread
816 it is for, or it'll be ignored when it triggers. */
818 if (tp->control.step_resume_breakpoint)
820 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
821 tp->control.step_resume_breakpoint->loc->enabled = 1;
824 /* Treat exception_resume breakpoints like step_resume breakpoints. */
825 if (tp->control.exception_resume_breakpoint)
827 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
828 tp->control.exception_resume_breakpoint->loc->enabled = 1;
831 /* Reinsert all breakpoints in the child. The user may have set
832 breakpoints after catching the fork, in which case those
833 were never set in the child, but only in the parent. This makes
834 sure the inserted breakpoints match the breakpoint list. */
836 breakpoint_re_set ();
837 insert_breakpoints ();
840 /* The child has exited or execed: resume threads of the parent the
841 user wanted to be executing. */
844 proceed_after_vfork_done (struct thread_info *thread,
847 int pid = * (int *) arg;
849 if (ptid_get_pid (thread->ptid) == pid
850 && is_running (thread->ptid)
851 && !is_executing (thread->ptid)
852 && !thread->stop_requested
853 && thread->suspend.stop_signal == GDB_SIGNAL_0)
856 fprintf_unfiltered (gdb_stdlog,
857 "infrun: resuming vfork parent thread %s\n",
858 target_pid_to_str (thread->ptid));
860 switch_to_thread (thread->ptid);
861 clear_proceed_status (0);
862 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
868 /* Called whenever we notice an exec or exit event, to handle
869 detaching or resuming a vfork parent. */
872 handle_vfork_child_exec_or_exit (int exec)
874 struct inferior *inf = current_inferior ();
876 if (inf->vfork_parent)
878 int resume_parent = -1;
880 /* This exec or exit marks the end of the shared memory region
881 between the parent and the child. If the user wanted to
882 detach from the parent, now is the time. */
884 if (inf->vfork_parent->pending_detach)
886 struct thread_info *tp;
887 struct cleanup *old_chain;
888 struct program_space *pspace;
889 struct address_space *aspace;
891 /* follow-fork child, detach-on-fork on. */
893 inf->vfork_parent->pending_detach = 0;
897 /* If we're handling a child exit, then inferior_ptid
898 points at the inferior's pid, not to a thread. */
899 old_chain = save_inferior_ptid ();
900 save_current_program_space ();
901 save_current_inferior ();
904 old_chain = save_current_space_and_thread ();
906 /* We're letting loose of the parent. */
907 tp = any_live_thread_of_process (inf->vfork_parent->pid);
908 switch_to_thread (tp->ptid);
910 /* We're about to detach from the parent, which implicitly
911 removes breakpoints from its address space. There's a
912 catch here: we want to reuse the spaces for the child,
913 but, parent/child are still sharing the pspace at this
914 point, although the exec in reality makes the kernel give
915 the child a fresh set of new pages. The problem here is
916 that the breakpoints module being unaware of this, would
917 likely chose the child process to write to the parent
918 address space. Swapping the child temporarily away from
919 the spaces has the desired effect. Yes, this is "sort
922 pspace = inf->pspace;
923 aspace = inf->aspace;
927 if (debug_infrun || info_verbose)
929 target_terminal_ours_for_output ();
933 fprintf_filtered (gdb_stdlog,
934 _("Detaching vfork parent process "
935 "%d after child exec.\n"),
936 inf->vfork_parent->pid);
940 fprintf_filtered (gdb_stdlog,
941 _("Detaching vfork parent process "
942 "%d after child exit.\n"),
943 inf->vfork_parent->pid);
947 target_detach (NULL, 0);
950 inf->pspace = pspace;
951 inf->aspace = aspace;
953 do_cleanups (old_chain);
957 /* We're staying attached to the parent, so, really give the
958 child a new address space. */
959 inf->pspace = add_program_space (maybe_new_address_space ());
960 inf->aspace = inf->pspace->aspace;
962 set_current_program_space (inf->pspace);
964 resume_parent = inf->vfork_parent->pid;
966 /* Break the bonds. */
967 inf->vfork_parent->vfork_child = NULL;
971 struct cleanup *old_chain;
972 struct program_space *pspace;
974 /* If this is a vfork child exiting, then the pspace and
975 aspaces were shared with the parent. Since we're
976 reporting the process exit, we'll be mourning all that is
977 found in the address space, and switching to null_ptid,
978 preparing to start a new inferior. But, since we don't
979 want to clobber the parent's address/program spaces, we
980 go ahead and create a new one for this exiting
983 /* Switch to null_ptid, so that clone_program_space doesn't want
984 to read the selected frame of a dead process. */
985 old_chain = save_inferior_ptid ();
986 inferior_ptid = null_ptid;
988 /* This inferior is dead, so avoid giving the breakpoints
989 module the option to write through to it (cloning a
990 program space resets breakpoints). */
993 pspace = add_program_space (maybe_new_address_space ());
994 set_current_program_space (pspace);
996 inf->symfile_flags = SYMFILE_NO_READ;
997 clone_program_space (pspace, inf->vfork_parent->pspace);
998 inf->pspace = pspace;
999 inf->aspace = pspace->aspace;
1001 /* Put back inferior_ptid. We'll continue mourning this
1003 do_cleanups (old_chain);
1005 resume_parent = inf->vfork_parent->pid;
1006 /* Break the bonds. */
1007 inf->vfork_parent->vfork_child = NULL;
1010 inf->vfork_parent = NULL;
1012 gdb_assert (current_program_space == inf->pspace);
1014 if (non_stop && resume_parent != -1)
1016 /* If the user wanted the parent to be running, let it go
1018 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
1021 fprintf_unfiltered (gdb_stdlog,
1022 "infrun: resuming vfork parent process %d\n",
1025 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1027 do_cleanups (old_chain);
1032 /* Enum strings for "set|show follow-exec-mode". */
1034 static const char follow_exec_mode_new[] = "new";
1035 static const char follow_exec_mode_same[] = "same";
1036 static const char *const follow_exec_mode_names[] =
1038 follow_exec_mode_new,
1039 follow_exec_mode_same,
1043 static const char *follow_exec_mode_string = follow_exec_mode_same;
1045 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1046 struct cmd_list_element *c, const char *value)
1048 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1051 /* EXECD_PATHNAME is assumed to be non-NULL. */
1054 follow_exec (ptid_t ptid, char *execd_pathname)
1056 struct thread_info *th, *tmp;
1057 struct inferior *inf = current_inferior ();
1058 int pid = ptid_get_pid (ptid);
1060 /* This is an exec event that we actually wish to pay attention to.
1061 Refresh our symbol table to the newly exec'd program, remove any
1062 momentary bp's, etc.
1064 If there are breakpoints, they aren't really inserted now,
1065 since the exec() transformed our inferior into a fresh set
1068 We want to preserve symbolic breakpoints on the list, since
1069 we have hopes that they can be reset after the new a.out's
1070 symbol table is read.
1072 However, any "raw" breakpoints must be removed from the list
1073 (e.g., the solib bp's), since their address is probably invalid
1076 And, we DON'T want to call delete_breakpoints() here, since
1077 that may write the bp's "shadow contents" (the instruction
1078 value that was overwritten witha TRAP instruction). Since
1079 we now have a new a.out, those shadow contents aren't valid. */
1081 mark_breakpoints_out ();
1083 /* The target reports the exec event to the main thread, even if
1084 some other thread does the exec, and even if the main thread was
1085 stopped or already gone. We may still have non-leader threads of
1086 the process on our list. E.g., on targets that don't have thread
1087 exit events (like remote); or on native Linux in non-stop mode if
1088 there were only two threads in the inferior and the non-leader
1089 one is the one that execs (and nothing forces an update of the
1090 thread list up to here). When debugging remotely, it's best to
1091 avoid extra traffic, when possible, so avoid syncing the thread
1092 list with the target, and instead go ahead and delete all threads
1093 of the process but one that reported the event. Note this must
1094 be done before calling update_breakpoints_after_exec, as
1095 otherwise clearing the threads' resources would reference stale
1096 thread breakpoints -- it may have been one of these threads that
1097 stepped across the exec. We could just clear their stepping
1098 states, but as long as we're iterating, might as well delete
1099 them. Deleting them now rather than at the next user-visible
1100 stop provides a nicer sequence of events for user and MI
1102 ALL_NON_EXITED_THREADS_SAFE (th, tmp)
1103 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1104 delete_thread (th->ptid);
1106 /* We also need to clear any left over stale state for the
1107 leader/event thread. E.g., if there was any step-resume
1108 breakpoint or similar, it's gone now. We cannot truly
1109 step-to-next statement through an exec(). */
1110 th = inferior_thread ();
1111 th->control.step_resume_breakpoint = NULL;
1112 th->control.exception_resume_breakpoint = NULL;
1113 th->control.single_step_breakpoints = NULL;
1114 th->control.step_range_start = 0;
1115 th->control.step_range_end = 0;
1117 /* The user may have had the main thread held stopped in the
1118 previous image (e.g., schedlock on, or non-stop). Release
1120 th->stop_requested = 0;
1122 update_breakpoints_after_exec ();
1124 /* What is this a.out's name? */
1125 printf_unfiltered (_("%s is executing new program: %s\n"),
1126 target_pid_to_str (inferior_ptid),
1129 /* We've followed the inferior through an exec. Therefore, the
1130 inferior has essentially been killed & reborn. */
1132 gdb_flush (gdb_stdout);
1134 breakpoint_init_inferior (inf_execd);
1136 if (gdb_sysroot && *gdb_sysroot)
1138 char *name = alloca (strlen (gdb_sysroot)
1139 + strlen (execd_pathname)
1142 strcpy (name, gdb_sysroot);
1143 strcat (name, execd_pathname);
1144 execd_pathname = name;
1147 /* Reset the shared library package. This ensures that we get a
1148 shlib event when the child reaches "_start", at which point the
1149 dld will have had a chance to initialize the child. */
1150 /* Also, loading a symbol file below may trigger symbol lookups, and
1151 we don't want those to be satisfied by the libraries of the
1152 previous incarnation of this process. */
1153 no_shared_libraries (NULL, 0);
1155 if (follow_exec_mode_string == follow_exec_mode_new)
1157 struct program_space *pspace;
1159 /* The user wants to keep the old inferior and program spaces
1160 around. Create a new fresh one, and switch to it. */
1162 inf = add_inferior (current_inferior ()->pid);
1163 pspace = add_program_space (maybe_new_address_space ());
1164 inf->pspace = pspace;
1165 inf->aspace = pspace->aspace;
1167 exit_inferior_num_silent (current_inferior ()->num);
1169 set_current_inferior (inf);
1170 set_current_program_space (pspace);
1174 /* The old description may no longer be fit for the new image.
1175 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1176 old description; we'll read a new one below. No need to do
1177 this on "follow-exec-mode new", as the old inferior stays
1178 around (its description is later cleared/refetched on
1180 target_clear_description ();
1183 gdb_assert (current_program_space == inf->pspace);
1185 /* That a.out is now the one to use. */
1186 exec_file_attach (execd_pathname, 0);
1188 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
1189 (Position Independent Executable) main symbol file will get applied by
1190 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
1191 the breakpoints with the zero displacement. */
1193 symbol_file_add (execd_pathname,
1195 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
1198 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
1199 set_initial_language ();
1201 /* If the target can specify a description, read it. Must do this
1202 after flipping to the new executable (because the target supplied
1203 description must be compatible with the executable's
1204 architecture, and the old executable may e.g., be 32-bit, while
1205 the new one 64-bit), and before anything involving memory or
1207 target_find_description ();
1209 solib_create_inferior_hook (0);
1211 jit_inferior_created_hook ();
1213 breakpoint_re_set ();
1215 /* Reinsert all breakpoints. (Those which were symbolic have
1216 been reset to the proper address in the new a.out, thanks
1217 to symbol_file_command...). */
1218 insert_breakpoints ();
1220 /* The next resume of this inferior should bring it to the shlib
1221 startup breakpoints. (If the user had also set bp's on
1222 "main" from the old (parent) process, then they'll auto-
1223 matically get reset there in the new process.). */
1226 /* Info about an instruction that is being stepped over. */
1228 struct step_over_info
1230 /* If we're stepping past a breakpoint, this is the address space
1231 and address of the instruction the breakpoint is set at. We'll
1232 skip inserting all breakpoints here. Valid iff ASPACE is
1234 struct address_space *aspace;
1237 /* The instruction being stepped over triggers a nonsteppable
1238 watchpoint. If true, we'll skip inserting watchpoints. */
1239 int nonsteppable_watchpoint_p;
1242 /* The step-over info of the location that is being stepped over.
1244 Note that with async/breakpoint always-inserted mode, a user might
1245 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1246 being stepped over. As setting a new breakpoint inserts all
1247 breakpoints, we need to make sure the breakpoint being stepped over
1248 isn't inserted then. We do that by only clearing the step-over
1249 info when the step-over is actually finished (or aborted).
1251 Presently GDB can only step over one breakpoint at any given time.
1252 Given threads that can't run code in the same address space as the
1253 breakpoint's can't really miss the breakpoint, GDB could be taught
1254 to step-over at most one breakpoint per address space (so this info
1255 could move to the address space object if/when GDB is extended).
1256 The set of breakpoints being stepped over will normally be much
1257 smaller than the set of all breakpoints, so a flag in the
1258 breakpoint location structure would be wasteful. A separate list
1259 also saves complexity and run-time, as otherwise we'd have to go
1260 through all breakpoint locations clearing their flag whenever we
1261 start a new sequence. Similar considerations weigh against storing
1262 this info in the thread object. Plus, not all step overs actually
1263 have breakpoint locations -- e.g., stepping past a single-step
1264 breakpoint, or stepping to complete a non-continuable
1266 static struct step_over_info step_over_info;
1268 /* Record the address of the breakpoint/instruction we're currently
1272 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1273 int nonsteppable_watchpoint_p)
1275 step_over_info.aspace = aspace;
1276 step_over_info.address = address;
1277 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1280 /* Called when we're not longer stepping over a breakpoint / an
1281 instruction, so all breakpoints are free to be (re)inserted. */
1284 clear_step_over_info (void)
1286 step_over_info.aspace = NULL;
1287 step_over_info.address = 0;
1288 step_over_info.nonsteppable_watchpoint_p = 0;
1294 stepping_past_instruction_at (struct address_space *aspace,
1297 return (step_over_info.aspace != NULL
1298 && breakpoint_address_match (aspace, address,
1299 step_over_info.aspace,
1300 step_over_info.address));
1306 stepping_past_nonsteppable_watchpoint (void)
1308 return step_over_info.nonsteppable_watchpoint_p;
1311 /* Returns true if step-over info is valid. */
1314 step_over_info_valid_p (void)
1316 return (step_over_info.aspace != NULL
1317 || stepping_past_nonsteppable_watchpoint ());
1321 /* Displaced stepping. */
1323 /* In non-stop debugging mode, we must take special care to manage
1324 breakpoints properly; in particular, the traditional strategy for
1325 stepping a thread past a breakpoint it has hit is unsuitable.
1326 'Displaced stepping' is a tactic for stepping one thread past a
1327 breakpoint it has hit while ensuring that other threads running
1328 concurrently will hit the breakpoint as they should.
1330 The traditional way to step a thread T off a breakpoint in a
1331 multi-threaded program in all-stop mode is as follows:
1333 a0) Initially, all threads are stopped, and breakpoints are not
1335 a1) We single-step T, leaving breakpoints uninserted.
1336 a2) We insert breakpoints, and resume all threads.
1338 In non-stop debugging, however, this strategy is unsuitable: we
1339 don't want to have to stop all threads in the system in order to
1340 continue or step T past a breakpoint. Instead, we use displaced
1343 n0) Initially, T is stopped, other threads are running, and
1344 breakpoints are inserted.
1345 n1) We copy the instruction "under" the breakpoint to a separate
1346 location, outside the main code stream, making any adjustments
1347 to the instruction, register, and memory state as directed by
1349 n2) We single-step T over the instruction at its new location.
1350 n3) We adjust the resulting register and memory state as directed
1351 by T's architecture. This includes resetting T's PC to point
1352 back into the main instruction stream.
1355 This approach depends on the following gdbarch methods:
1357 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1358 indicate where to copy the instruction, and how much space must
1359 be reserved there. We use these in step n1.
1361 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1362 address, and makes any necessary adjustments to the instruction,
1363 register contents, and memory. We use this in step n1.
1365 - gdbarch_displaced_step_fixup adjusts registers and memory after
1366 we have successfuly single-stepped the instruction, to yield the
1367 same effect the instruction would have had if we had executed it
1368 at its original address. We use this in step n3.
1370 - gdbarch_displaced_step_free_closure provides cleanup.
1372 The gdbarch_displaced_step_copy_insn and
1373 gdbarch_displaced_step_fixup functions must be written so that
1374 copying an instruction with gdbarch_displaced_step_copy_insn,
1375 single-stepping across the copied instruction, and then applying
1376 gdbarch_displaced_insn_fixup should have the same effects on the
1377 thread's memory and registers as stepping the instruction in place
1378 would have. Exactly which responsibilities fall to the copy and
1379 which fall to the fixup is up to the author of those functions.
1381 See the comments in gdbarch.sh for details.
1383 Note that displaced stepping and software single-step cannot
1384 currently be used in combination, although with some care I think
1385 they could be made to. Software single-step works by placing
1386 breakpoints on all possible subsequent instructions; if the
1387 displaced instruction is a PC-relative jump, those breakpoints
1388 could fall in very strange places --- on pages that aren't
1389 executable, or at addresses that are not proper instruction
1390 boundaries. (We do generally let other threads run while we wait
1391 to hit the software single-step breakpoint, and they might
1392 encounter such a corrupted instruction.) One way to work around
1393 this would be to have gdbarch_displaced_step_copy_insn fully
1394 simulate the effect of PC-relative instructions (and return NULL)
1395 on architectures that use software single-stepping.
1397 In non-stop mode, we can have independent and simultaneous step
1398 requests, so more than one thread may need to simultaneously step
1399 over a breakpoint. The current implementation assumes there is
1400 only one scratch space per process. In this case, we have to
1401 serialize access to the scratch space. If thread A wants to step
1402 over a breakpoint, but we are currently waiting for some other
1403 thread to complete a displaced step, we leave thread A stopped and
1404 place it in the displaced_step_request_queue. Whenever a displaced
1405 step finishes, we pick the next thread in the queue and start a new
1406 displaced step operation on it. See displaced_step_prepare and
1407 displaced_step_fixup for details. */
1409 struct displaced_step_request
1412 struct displaced_step_request *next;
1415 /* Per-inferior displaced stepping state. */
1416 struct displaced_step_inferior_state
1418 /* Pointer to next in linked list. */
1419 struct displaced_step_inferior_state *next;
1421 /* The process this displaced step state refers to. */
1424 /* A queue of pending displaced stepping requests. One entry per
1425 thread that needs to do a displaced step. */
1426 struct displaced_step_request *step_request_queue;
1428 /* If this is not null_ptid, this is the thread carrying out a
1429 displaced single-step in process PID. This thread's state will
1430 require fixing up once it has completed its step. */
1433 /* The architecture the thread had when we stepped it. */
1434 struct gdbarch *step_gdbarch;
1436 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1437 for post-step cleanup. */
1438 struct displaced_step_closure *step_closure;
1440 /* The address of the original instruction, and the copy we
1442 CORE_ADDR step_original, step_copy;
1444 /* Saved contents of copy area. */
1445 gdb_byte *step_saved_copy;
1448 /* The list of states of processes involved in displaced stepping
1450 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1452 /* Get the displaced stepping state of process PID. */
1454 static struct displaced_step_inferior_state *
1455 get_displaced_stepping_state (int pid)
1457 struct displaced_step_inferior_state *state;
1459 for (state = displaced_step_inferior_states;
1461 state = state->next)
1462 if (state->pid == pid)
1468 /* Add a new displaced stepping state for process PID to the displaced
1469 stepping state list, or return a pointer to an already existing
1470 entry, if it already exists. Never returns NULL. */
1472 static struct displaced_step_inferior_state *
1473 add_displaced_stepping_state (int pid)
1475 struct displaced_step_inferior_state *state;
1477 for (state = displaced_step_inferior_states;
1479 state = state->next)
1480 if (state->pid == pid)
1483 state = xcalloc (1, sizeof (*state));
1485 state->next = displaced_step_inferior_states;
1486 displaced_step_inferior_states = state;
1491 /* If inferior is in displaced stepping, and ADDR equals to starting address
1492 of copy area, return corresponding displaced_step_closure. Otherwise,
1495 struct displaced_step_closure*
1496 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1498 struct displaced_step_inferior_state *displaced
1499 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1501 /* If checking the mode of displaced instruction in copy area. */
1502 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1503 && (displaced->step_copy == addr))
1504 return displaced->step_closure;
1509 /* Remove the displaced stepping state of process PID. */
1512 remove_displaced_stepping_state (int pid)
1514 struct displaced_step_inferior_state *it, **prev_next_p;
1516 gdb_assert (pid != 0);
1518 it = displaced_step_inferior_states;
1519 prev_next_p = &displaced_step_inferior_states;
1524 *prev_next_p = it->next;
1529 prev_next_p = &it->next;
1535 infrun_inferior_exit (struct inferior *inf)
1537 remove_displaced_stepping_state (inf->pid);
1540 /* If ON, and the architecture supports it, GDB will use displaced
1541 stepping to step over breakpoints. If OFF, or if the architecture
1542 doesn't support it, GDB will instead use the traditional
1543 hold-and-step approach. If AUTO (which is the default), GDB will
1544 decide which technique to use to step over breakpoints depending on
1545 which of all-stop or non-stop mode is active --- displaced stepping
1546 in non-stop mode; hold-and-step in all-stop mode. */
1548 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1551 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1552 struct cmd_list_element *c,
1555 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1556 fprintf_filtered (file,
1557 _("Debugger's willingness to use displaced stepping "
1558 "to step over breakpoints is %s (currently %s).\n"),
1559 value, non_stop ? "on" : "off");
1561 fprintf_filtered (file,
1562 _("Debugger's willingness to use displaced stepping "
1563 "to step over breakpoints is %s.\n"), value);
1566 /* Return non-zero if displaced stepping can/should be used to step
1567 over breakpoints. */
1570 use_displaced_stepping (struct gdbarch *gdbarch)
1572 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1573 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1574 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1575 && find_record_target () == NULL);
1578 /* Clean out any stray displaced stepping state. */
1580 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1582 /* Indicate that there is no cleanup pending. */
1583 displaced->step_ptid = null_ptid;
1585 if (displaced->step_closure)
1587 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1588 displaced->step_closure);
1589 displaced->step_closure = NULL;
1594 displaced_step_clear_cleanup (void *arg)
1596 struct displaced_step_inferior_state *state = arg;
1598 displaced_step_clear (state);
1601 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1603 displaced_step_dump_bytes (struct ui_file *file,
1604 const gdb_byte *buf,
1609 for (i = 0; i < len; i++)
1610 fprintf_unfiltered (file, "%02x ", buf[i]);
1611 fputs_unfiltered ("\n", file);
1614 /* Prepare to single-step, using displaced stepping.
1616 Note that we cannot use displaced stepping when we have a signal to
1617 deliver. If we have a signal to deliver and an instruction to step
1618 over, then after the step, there will be no indication from the
1619 target whether the thread entered a signal handler or ignored the
1620 signal and stepped over the instruction successfully --- both cases
1621 result in a simple SIGTRAP. In the first case we mustn't do a
1622 fixup, and in the second case we must --- but we can't tell which.
1623 Comments in the code for 'random signals' in handle_inferior_event
1624 explain how we handle this case instead.
1626 Returns 1 if preparing was successful -- this thread is going to be
1627 stepped now; or 0 if displaced stepping this thread got queued. */
1629 displaced_step_prepare (ptid_t ptid)
1631 struct cleanup *old_cleanups, *ignore_cleanups;
1632 struct thread_info *tp = find_thread_ptid (ptid);
1633 struct regcache *regcache = get_thread_regcache (ptid);
1634 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1635 CORE_ADDR original, copy;
1637 struct displaced_step_closure *closure;
1638 struct displaced_step_inferior_state *displaced;
1641 /* We should never reach this function if the architecture does not
1642 support displaced stepping. */
1643 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1645 /* Disable range stepping while executing in the scratch pad. We
1646 want a single-step even if executing the displaced instruction in
1647 the scratch buffer lands within the stepping range (e.g., a
1649 tp->control.may_range_step = 0;
1651 /* We have to displaced step one thread at a time, as we only have
1652 access to a single scratch space per inferior. */
1654 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1656 if (!ptid_equal (displaced->step_ptid, null_ptid))
1658 /* Already waiting for a displaced step to finish. Defer this
1659 request and place in queue. */
1660 struct displaced_step_request *req, *new_req;
1662 if (debug_displaced)
1663 fprintf_unfiltered (gdb_stdlog,
1664 "displaced: defering step of %s\n",
1665 target_pid_to_str (ptid));
1667 new_req = xmalloc (sizeof (*new_req));
1668 new_req->ptid = ptid;
1669 new_req->next = NULL;
1671 if (displaced->step_request_queue)
1673 for (req = displaced->step_request_queue;
1677 req->next = new_req;
1680 displaced->step_request_queue = new_req;
1686 if (debug_displaced)
1687 fprintf_unfiltered (gdb_stdlog,
1688 "displaced: stepping %s now\n",
1689 target_pid_to_str (ptid));
1692 displaced_step_clear (displaced);
1694 old_cleanups = save_inferior_ptid ();
1695 inferior_ptid = ptid;
1697 original = regcache_read_pc (regcache);
1699 copy = gdbarch_displaced_step_location (gdbarch);
1700 len = gdbarch_max_insn_length (gdbarch);
1702 /* Save the original contents of the copy area. */
1703 displaced->step_saved_copy = xmalloc (len);
1704 ignore_cleanups = make_cleanup (free_current_contents,
1705 &displaced->step_saved_copy);
1706 status = target_read_memory (copy, displaced->step_saved_copy, len);
1708 throw_error (MEMORY_ERROR,
1709 _("Error accessing memory address %s (%s) for "
1710 "displaced-stepping scratch space."),
1711 paddress (gdbarch, copy), safe_strerror (status));
1712 if (debug_displaced)
1714 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1715 paddress (gdbarch, copy));
1716 displaced_step_dump_bytes (gdb_stdlog,
1717 displaced->step_saved_copy,
1721 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1722 original, copy, regcache);
1724 /* We don't support the fully-simulated case at present. */
1725 gdb_assert (closure);
1727 /* Save the information we need to fix things up if the step
1729 displaced->step_ptid = ptid;
1730 displaced->step_gdbarch = gdbarch;
1731 displaced->step_closure = closure;
1732 displaced->step_original = original;
1733 displaced->step_copy = copy;
1735 make_cleanup (displaced_step_clear_cleanup, displaced);
1737 /* Resume execution at the copy. */
1738 regcache_write_pc (regcache, copy);
1740 discard_cleanups (ignore_cleanups);
1742 do_cleanups (old_cleanups);
1744 if (debug_displaced)
1745 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1746 paddress (gdbarch, copy));
1752 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1753 const gdb_byte *myaddr, int len)
1755 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1757 inferior_ptid = ptid;
1758 write_memory (memaddr, myaddr, len);
1759 do_cleanups (ptid_cleanup);
1762 /* Restore the contents of the copy area for thread PTID. */
1765 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1768 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1770 write_memory_ptid (ptid, displaced->step_copy,
1771 displaced->step_saved_copy, len);
1772 if (debug_displaced)
1773 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1774 target_pid_to_str (ptid),
1775 paddress (displaced->step_gdbarch,
1776 displaced->step_copy));
1780 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1782 struct cleanup *old_cleanups;
1783 struct displaced_step_inferior_state *displaced
1784 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1786 /* Was any thread of this process doing a displaced step? */
1787 if (displaced == NULL)
1790 /* Was this event for the pid we displaced? */
1791 if (ptid_equal (displaced->step_ptid, null_ptid)
1792 || ! ptid_equal (displaced->step_ptid, event_ptid))
1795 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1797 displaced_step_restore (displaced, displaced->step_ptid);
1799 /* Did the instruction complete successfully? */
1800 if (signal == GDB_SIGNAL_TRAP)
1802 /* Fixup may need to read memory/registers. Switch to the
1803 thread that we're fixing up. */
1804 switch_to_thread (event_ptid);
1806 /* Fix up the resulting state. */
1807 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1808 displaced->step_closure,
1809 displaced->step_original,
1810 displaced->step_copy,
1811 get_thread_regcache (displaced->step_ptid));
1815 /* Since the instruction didn't complete, all we can do is
1817 struct regcache *regcache = get_thread_regcache (event_ptid);
1818 CORE_ADDR pc = regcache_read_pc (regcache);
1820 pc = displaced->step_original + (pc - displaced->step_copy);
1821 regcache_write_pc (regcache, pc);
1824 do_cleanups (old_cleanups);
1826 displaced->step_ptid = null_ptid;
1828 /* Are there any pending displaced stepping requests? If so, run
1829 one now. Leave the state object around, since we're likely to
1830 need it again soon. */
1831 while (displaced->step_request_queue)
1833 struct displaced_step_request *head;
1835 struct regcache *regcache;
1836 struct gdbarch *gdbarch;
1837 CORE_ADDR actual_pc;
1838 struct address_space *aspace;
1840 head = displaced->step_request_queue;
1842 displaced->step_request_queue = head->next;
1845 context_switch (ptid);
1847 regcache = get_thread_regcache (ptid);
1848 actual_pc = regcache_read_pc (regcache);
1849 aspace = get_regcache_aspace (regcache);
1851 if (breakpoint_here_p (aspace, actual_pc))
1853 if (debug_displaced)
1854 fprintf_unfiltered (gdb_stdlog,
1855 "displaced: stepping queued %s now\n",
1856 target_pid_to_str (ptid));
1858 displaced_step_prepare (ptid);
1860 gdbarch = get_regcache_arch (regcache);
1862 if (debug_displaced)
1864 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1867 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1868 paddress (gdbarch, actual_pc));
1869 read_memory (actual_pc, buf, sizeof (buf));
1870 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1873 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1874 displaced->step_closure))
1875 target_resume (ptid, 1, GDB_SIGNAL_0);
1877 target_resume (ptid, 0, GDB_SIGNAL_0);
1879 /* Done, we're stepping a thread. */
1885 struct thread_info *tp = inferior_thread ();
1887 /* The breakpoint we were sitting under has since been
1889 tp->control.trap_expected = 0;
1891 /* Go back to what we were trying to do. */
1892 step = currently_stepping (tp);
1894 if (debug_displaced)
1895 fprintf_unfiltered (gdb_stdlog,
1896 "displaced: breakpoint is gone: %s, step(%d)\n",
1897 target_pid_to_str (tp->ptid), step);
1899 target_resume (ptid, step, GDB_SIGNAL_0);
1900 tp->suspend.stop_signal = GDB_SIGNAL_0;
1902 /* This request was discarded. See if there's any other
1903 thread waiting for its turn. */
1908 /* Update global variables holding ptids to hold NEW_PTID if they were
1909 holding OLD_PTID. */
1911 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1913 struct displaced_step_request *it;
1914 struct displaced_step_inferior_state *displaced;
1916 if (ptid_equal (inferior_ptid, old_ptid))
1917 inferior_ptid = new_ptid;
1919 for (displaced = displaced_step_inferior_states;
1921 displaced = displaced->next)
1923 if (ptid_equal (displaced->step_ptid, old_ptid))
1924 displaced->step_ptid = new_ptid;
1926 for (it = displaced->step_request_queue; it; it = it->next)
1927 if (ptid_equal (it->ptid, old_ptid))
1928 it->ptid = new_ptid;
1935 /* Things to clean up if we QUIT out of resume (). */
1937 resume_cleanups (void *ignore)
1939 if (!ptid_equal (inferior_ptid, null_ptid))
1940 delete_single_step_breakpoints (inferior_thread ());
1945 static const char schedlock_off[] = "off";
1946 static const char schedlock_on[] = "on";
1947 static const char schedlock_step[] = "step";
1948 static const char *const scheduler_enums[] = {
1954 static const char *scheduler_mode = schedlock_off;
1956 show_scheduler_mode (struct ui_file *file, int from_tty,
1957 struct cmd_list_element *c, const char *value)
1959 fprintf_filtered (file,
1960 _("Mode for locking scheduler "
1961 "during execution is \"%s\".\n"),
1966 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1968 if (!target_can_lock_scheduler)
1970 scheduler_mode = schedlock_off;
1971 error (_("Target '%s' cannot support this command."), target_shortname);
1975 /* True if execution commands resume all threads of all processes by
1976 default; otherwise, resume only threads of the current inferior
1978 int sched_multi = 0;
1980 /* Try to setup for software single stepping over the specified location.
1981 Return 1 if target_resume() should use hardware single step.
1983 GDBARCH the current gdbarch.
1984 PC the location to step over. */
1987 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1991 if (execution_direction == EXEC_FORWARD
1992 && gdbarch_software_single_step_p (gdbarch)
1993 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
2001 user_visible_resume_ptid (int step)
2003 /* By default, resume all threads of all processes. */
2004 ptid_t resume_ptid = RESUME_ALL;
2006 /* Maybe resume only all threads of the current process. */
2007 if (!sched_multi && target_supports_multi_process ())
2009 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2012 /* Maybe resume a single thread after all. */
2015 /* With non-stop mode on, threads are always handled
2017 resume_ptid = inferior_ptid;
2019 else if ((scheduler_mode == schedlock_on)
2020 || (scheduler_mode == schedlock_step && step))
2022 /* User-settable 'scheduler' mode requires solo thread resume. */
2023 resume_ptid = inferior_ptid;
2026 /* We may actually resume fewer threads at first, e.g., if a thread
2027 is stopped at a breakpoint that needs stepping-off, but that
2028 should not be visible to the user/frontend, and neither should
2029 the frontend/user be allowed to proceed any of the threads that
2030 happen to be stopped for internal run control handling, if a
2031 previous command wanted them resumed. */
2035 /* Wrapper for target_resume, that handles infrun-specific
2039 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2041 struct thread_info *tp = inferior_thread ();
2043 /* Install inferior's terminal modes. */
2044 target_terminal_inferior ();
2046 /* Avoid confusing the next resume, if the next stop/resume
2047 happens to apply to another thread. */
2048 tp->suspend.stop_signal = GDB_SIGNAL_0;
2050 /* Advise target which signals may be handled silently. If we have
2051 removed breakpoints because we are stepping over one (in any
2052 thread), we need to receive all signals to avoid accidentally
2053 skipping a breakpoint during execution of a signal handler. */
2054 if (step_over_info_valid_p ())
2055 target_pass_signals (0, NULL);
2057 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2059 target_resume (resume_ptid, step, sig);
2062 /* Resume the inferior, but allow a QUIT. This is useful if the user
2063 wants to interrupt some lengthy single-stepping operation
2064 (for child processes, the SIGINT goes to the inferior, and so
2065 we get a SIGINT random_signal, but for remote debugging and perhaps
2066 other targets, that's not true).
2068 SIG is the signal to give the inferior (zero for none). */
2070 resume (enum gdb_signal sig)
2072 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2073 struct regcache *regcache = get_current_regcache ();
2074 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2075 struct thread_info *tp = inferior_thread ();
2076 CORE_ADDR pc = regcache_read_pc (regcache);
2077 struct address_space *aspace = get_regcache_aspace (regcache);
2079 /* This represents the user's step vs continue request. When
2080 deciding whether "set scheduler-locking step" applies, it's the
2081 user's intention that counts. */
2082 const int user_step = tp->control.stepping_command;
2083 /* This represents what we'll actually request the target to do.
2084 This can decay from a step to a continue, if e.g., we need to
2085 implement single-stepping with breakpoints (software
2087 int step = currently_stepping (tp);
2089 tp->stepped_breakpoint = 0;
2093 if (current_inferior ()->waiting_for_vfork_done)
2095 /* Don't try to single-step a vfork parent that is waiting for
2096 the child to get out of the shared memory region (by exec'ing
2097 or exiting). This is particularly important on software
2098 single-step archs, as the child process would trip on the
2099 software single step breakpoint inserted for the parent
2100 process. Since the parent will not actually execute any
2101 instruction until the child is out of the shared region (such
2102 are vfork's semantics), it is safe to simply continue it.
2103 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2104 the parent, and tell it to `keep_going', which automatically
2105 re-sets it stepping. */
2107 fprintf_unfiltered (gdb_stdlog,
2108 "infrun: resume : clear step\n");
2113 fprintf_unfiltered (gdb_stdlog,
2114 "infrun: resume (step=%d, signal=%s), "
2115 "trap_expected=%d, current thread [%s] at %s\n",
2116 step, gdb_signal_to_symbol_string (sig),
2117 tp->control.trap_expected,
2118 target_pid_to_str (inferior_ptid),
2119 paddress (gdbarch, pc));
2121 /* Normally, by the time we reach `resume', the breakpoints are either
2122 removed or inserted, as appropriate. The exception is if we're sitting
2123 at a permanent breakpoint; we need to step over it, but permanent
2124 breakpoints can't be removed. So we have to test for it here. */
2125 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2127 if (sig != GDB_SIGNAL_0)
2129 /* We have a signal to pass to the inferior. The resume
2130 may, or may not take us to the signal handler. If this
2131 is a step, we'll need to stop in the signal handler, if
2132 there's one, (if the target supports stepping into
2133 handlers), or in the next mainline instruction, if
2134 there's no handler. If this is a continue, we need to be
2135 sure to run the handler with all breakpoints inserted.
2136 In all cases, set a breakpoint at the current address
2137 (where the handler returns to), and once that breakpoint
2138 is hit, resume skipping the permanent breakpoint. If
2139 that breakpoint isn't hit, then we've stepped into the
2140 signal handler (or hit some other event). We'll delete
2141 the step-resume breakpoint then. */
2144 fprintf_unfiltered (gdb_stdlog,
2145 "infrun: resume: skipping permanent breakpoint, "
2146 "deliver signal first\n");
2148 clear_step_over_info ();
2149 tp->control.trap_expected = 0;
2151 if (tp->control.step_resume_breakpoint == NULL)
2153 /* Set a "high-priority" step-resume, as we don't want
2154 user breakpoints at PC to trigger (again) when this
2156 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2157 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2159 tp->step_after_step_resume_breakpoint = step;
2162 insert_breakpoints ();
2166 /* There's no signal to pass, we can go ahead and skip the
2167 permanent breakpoint manually. */
2169 fprintf_unfiltered (gdb_stdlog,
2170 "infrun: resume: skipping permanent breakpoint\n");
2171 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2172 /* Update pc to reflect the new address from which we will
2173 execute instructions. */
2174 pc = regcache_read_pc (regcache);
2178 /* We've already advanced the PC, so the stepping part
2179 is done. Now we need to arrange for a trap to be
2180 reported to handle_inferior_event. Set a breakpoint
2181 at the current PC, and run to it. Don't update
2182 prev_pc, because if we end in
2183 switch_back_to_stepping, we want the "expected thread
2184 advanced also" branch to be taken. IOW, we don't
2185 want this thread to step further from PC
2187 insert_single_step_breakpoint (gdbarch, aspace, pc);
2188 insert_breakpoints ();
2190 tp->suspend.stop_signal = GDB_SIGNAL_0;
2191 /* We're continuing with all breakpoints inserted. It's
2192 safe to let the target bypass signals. */
2193 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2194 /* ... and safe to let other threads run, according to
2196 resume_ptid = user_visible_resume_ptid (user_step);
2197 target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2198 discard_cleanups (old_cleanups);
2204 /* If we have a breakpoint to step over, make sure to do a single
2205 step only. Same if we have software watchpoints. */
2206 if (tp->control.trap_expected || bpstat_should_step ())
2207 tp->control.may_range_step = 0;
2209 /* If enabled, step over breakpoints by executing a copy of the
2210 instruction at a different address.
2212 We can't use displaced stepping when we have a signal to deliver;
2213 the comments for displaced_step_prepare explain why. The
2214 comments in the handle_inferior event for dealing with 'random
2215 signals' explain what we do instead.
2217 We can't use displaced stepping when we are waiting for vfork_done
2218 event, displaced stepping breaks the vfork child similarly as single
2219 step software breakpoint. */
2220 if (use_displaced_stepping (gdbarch)
2221 && tp->control.trap_expected
2222 && sig == GDB_SIGNAL_0
2223 && !current_inferior ()->waiting_for_vfork_done)
2225 struct displaced_step_inferior_state *displaced;
2227 if (!displaced_step_prepare (inferior_ptid))
2229 /* Got placed in displaced stepping queue. Will be resumed
2230 later when all the currently queued displaced stepping
2231 requests finish. The thread is not executing at this
2232 point, and the call to set_executing will be made later.
2233 But we need to call set_running here, since from the
2234 user/frontend's point of view, threads were set running.
2235 Unless we're calling an inferior function, as in that
2236 case we pretend the inferior doesn't run at all. */
2237 if (!tp->control.in_infcall)
2238 set_running (user_visible_resume_ptid (user_step), 1);
2239 discard_cleanups (old_cleanups);
2243 /* Update pc to reflect the new address from which we will execute
2244 instructions due to displaced stepping. */
2245 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2247 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2248 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2249 displaced->step_closure);
2252 /* Do we need to do it the hard way, w/temp breakpoints? */
2254 step = maybe_software_singlestep (gdbarch, pc);
2256 /* Currently, our software single-step implementation leads to different
2257 results than hardware single-stepping in one situation: when stepping
2258 into delivering a signal which has an associated signal handler,
2259 hardware single-step will stop at the first instruction of the handler,
2260 while software single-step will simply skip execution of the handler.
2262 For now, this difference in behavior is accepted since there is no
2263 easy way to actually implement single-stepping into a signal handler
2264 without kernel support.
2266 However, there is one scenario where this difference leads to follow-on
2267 problems: if we're stepping off a breakpoint by removing all breakpoints
2268 and then single-stepping. In this case, the software single-step
2269 behavior means that even if there is a *breakpoint* in the signal
2270 handler, GDB still would not stop.
2272 Fortunately, we can at least fix this particular issue. We detect
2273 here the case where we are about to deliver a signal while software
2274 single-stepping with breakpoints removed. In this situation, we
2275 revert the decisions to remove all breakpoints and insert single-
2276 step breakpoints, and instead we install a step-resume breakpoint
2277 at the current address, deliver the signal without stepping, and
2278 once we arrive back at the step-resume breakpoint, actually step
2279 over the breakpoint we originally wanted to step over. */
2280 if (thread_has_single_step_breakpoints_set (tp)
2281 && sig != GDB_SIGNAL_0
2282 && step_over_info_valid_p ())
2284 /* If we have nested signals or a pending signal is delivered
2285 immediately after a handler returns, might might already have
2286 a step-resume breakpoint set on the earlier handler. We cannot
2287 set another step-resume breakpoint; just continue on until the
2288 original breakpoint is hit. */
2289 if (tp->control.step_resume_breakpoint == NULL)
2291 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2292 tp->step_after_step_resume_breakpoint = 1;
2295 delete_single_step_breakpoints (tp);
2297 clear_step_over_info ();
2298 tp->control.trap_expected = 0;
2300 insert_breakpoints ();
2303 /* If STEP is set, it's a request to use hardware stepping
2304 facilities. But in that case, we should never
2305 use singlestep breakpoint. */
2306 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2308 /* Decide the set of threads to ask the target to resume. Start
2309 by assuming everything will be resumed, than narrow the set
2310 by applying increasingly restricting conditions. */
2311 resume_ptid = user_visible_resume_ptid (user_step);
2313 /* Even if RESUME_PTID is a wildcard, and we end up resuming less
2314 (e.g., we might need to step over a breakpoint), from the
2315 user/frontend's point of view, all threads in RESUME_PTID are now
2316 running. Unless we're calling an inferior function, as in that
2317 case pretend we inferior doesn't run at all. */
2318 if (!tp->control.in_infcall)
2319 set_running (resume_ptid, 1);
2321 /* Maybe resume a single thread after all. */
2322 if ((step || thread_has_single_step_breakpoints_set (tp))
2323 && tp->control.trap_expected)
2325 /* We're allowing a thread to run past a breakpoint it has
2326 hit, by single-stepping the thread with the breakpoint
2327 removed. In which case, we need to single-step only this
2328 thread, and keep others stopped, as they can miss this
2329 breakpoint if allowed to run. */
2330 resume_ptid = inferior_ptid;
2333 if (execution_direction != EXEC_REVERSE
2334 && step && breakpoint_inserted_here_p (aspace, pc))
2336 /* The only case we currently need to step a breakpoint
2337 instruction is when we have a signal to deliver. See
2338 handle_signal_stop where we handle random signals that could
2339 take out us out of the stepping range. Normally, in that
2340 case we end up continuing (instead of stepping) over the
2341 signal handler with a breakpoint at PC, but there are cases
2342 where we should _always_ single-step, even if we have a
2343 step-resume breakpoint, like when a software watchpoint is
2344 set. Assuming single-stepping and delivering a signal at the
2345 same time would takes us to the signal handler, then we could
2346 have removed the breakpoint at PC to step over it. However,
2347 some hardware step targets (like e.g., Mac OS) can't step
2348 into signal handlers, and for those, we need to leave the
2349 breakpoint at PC inserted, as otherwise if the handler
2350 recurses and executes PC again, it'll miss the breakpoint.
2351 So we leave the breakpoint inserted anyway, but we need to
2352 record that we tried to step a breakpoint instruction, so
2353 that adjust_pc_after_break doesn't end up confused. */
2354 gdb_assert (sig != GDB_SIGNAL_0);
2356 tp->stepped_breakpoint = 1;
2358 /* Most targets can step a breakpoint instruction, thus
2359 executing it normally. But if this one cannot, just
2360 continue and we will hit it anyway. */
2361 if (gdbarch_cannot_step_breakpoint (gdbarch))
2366 && use_displaced_stepping (gdbarch)
2367 && tp->control.trap_expected)
2369 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
2370 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2371 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2374 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2375 paddress (resume_gdbarch, actual_pc));
2376 read_memory (actual_pc, buf, sizeof (buf));
2377 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2380 if (tp->control.may_range_step)
2382 /* If we're resuming a thread with the PC out of the step
2383 range, then we're doing some nested/finer run control
2384 operation, like stepping the thread out of the dynamic
2385 linker or the displaced stepping scratch pad. We
2386 shouldn't have allowed a range step then. */
2387 gdb_assert (pc_in_thread_step_range (pc, tp));
2390 do_target_resume (resume_ptid, step, sig);
2391 discard_cleanups (old_cleanups);
2396 /* Clear out all variables saying what to do when inferior is continued.
2397 First do this, then set the ones you want, then call `proceed'. */
2400 clear_proceed_status_thread (struct thread_info *tp)
2403 fprintf_unfiltered (gdb_stdlog,
2404 "infrun: clear_proceed_status_thread (%s)\n",
2405 target_pid_to_str (tp->ptid));
2407 /* If this signal should not be seen by program, give it zero.
2408 Used for debugging signals. */
2409 if (!signal_pass_state (tp->suspend.stop_signal))
2410 tp->suspend.stop_signal = GDB_SIGNAL_0;
2412 tp->control.trap_expected = 0;
2413 tp->control.step_range_start = 0;
2414 tp->control.step_range_end = 0;
2415 tp->control.may_range_step = 0;
2416 tp->control.step_frame_id = null_frame_id;
2417 tp->control.step_stack_frame_id = null_frame_id;
2418 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2419 tp->control.step_start_function = NULL;
2420 tp->stop_requested = 0;
2422 tp->control.stop_step = 0;
2424 tp->control.proceed_to_finish = 0;
2426 tp->control.command_interp = NULL;
2427 tp->control.stepping_command = 0;
2429 /* Discard any remaining commands or status from previous stop. */
2430 bpstat_clear (&tp->control.stop_bpstat);
2434 clear_proceed_status (int step)
2438 struct thread_info *tp;
2441 resume_ptid = user_visible_resume_ptid (step);
2443 /* In all-stop mode, delete the per-thread status of all threads
2444 we're about to resume, implicitly and explicitly. */
2445 ALL_NON_EXITED_THREADS (tp)
2447 if (!ptid_match (tp->ptid, resume_ptid))
2449 clear_proceed_status_thread (tp);
2453 if (!ptid_equal (inferior_ptid, null_ptid))
2455 struct inferior *inferior;
2459 /* If in non-stop mode, only delete the per-thread status of
2460 the current thread. */
2461 clear_proceed_status_thread (inferior_thread ());
2464 inferior = current_inferior ();
2465 inferior->control.stop_soon = NO_STOP_QUIETLY;
2468 stop_after_trap = 0;
2470 clear_step_over_info ();
2472 observer_notify_about_to_proceed ();
2476 regcache_xfree (stop_registers);
2477 stop_registers = NULL;
2481 /* Returns true if TP is still stopped at a breakpoint that needs
2482 stepping-over in order to make progress. If the breakpoint is gone
2483 meanwhile, we can skip the whole step-over dance. */
2486 thread_still_needs_step_over (struct thread_info *tp)
2488 if (tp->stepping_over_breakpoint)
2490 struct regcache *regcache = get_thread_regcache (tp->ptid);
2492 if (breakpoint_here_p (get_regcache_aspace (regcache),
2493 regcache_read_pc (regcache))
2494 == ordinary_breakpoint_here)
2497 tp->stepping_over_breakpoint = 0;
2503 /* Returns true if scheduler locking applies. STEP indicates whether
2504 we're about to do a step/next-like command to a thread. */
2507 schedlock_applies (struct thread_info *tp)
2509 return (scheduler_mode == schedlock_on
2510 || (scheduler_mode == schedlock_step
2511 && tp->control.stepping_command));
2514 /* Look a thread other than EXCEPT that has previously reported a
2515 breakpoint event, and thus needs a step-over in order to make
2516 progress. Returns NULL is none is found. */
2518 static struct thread_info *
2519 find_thread_needs_step_over (struct thread_info *except)
2521 struct thread_info *tp, *current;
2523 /* With non-stop mode on, threads are always handled individually. */
2524 gdb_assert (! non_stop);
2526 current = inferior_thread ();
2528 /* If scheduler locking applies, we can avoid iterating over all
2530 if (schedlock_applies (except))
2532 if (except != current
2533 && thread_still_needs_step_over (current))
2539 ALL_NON_EXITED_THREADS (tp)
2541 /* Ignore the EXCEPT thread. */
2544 /* Ignore threads of processes we're not resuming. */
2546 && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
2549 if (thread_still_needs_step_over (tp))
2556 /* Basic routine for continuing the program in various fashions.
2558 ADDR is the address to resume at, or -1 for resume where stopped.
2559 SIGGNAL is the signal to give it, or 0 for none,
2560 or -1 for act according to how it stopped.
2561 STEP is nonzero if should trap after one instruction.
2562 -1 means return after that and print nothing.
2563 You should probably set various step_... variables
2564 before calling here, if you are stepping.
2566 You should call clear_proceed_status before calling proceed. */
2569 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2571 struct regcache *regcache;
2572 struct gdbarch *gdbarch;
2573 struct thread_info *tp;
2575 struct address_space *aspace;
2577 /* If we're stopped at a fork/vfork, follow the branch set by the
2578 "set follow-fork-mode" command; otherwise, we'll just proceed
2579 resuming the current thread. */
2580 if (!follow_fork ())
2582 /* The target for some reason decided not to resume. */
2584 if (target_can_async_p ())
2585 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2589 /* We'll update this if & when we switch to a new thread. */
2590 previous_inferior_ptid = inferior_ptid;
2592 regcache = get_current_regcache ();
2593 gdbarch = get_regcache_arch (regcache);
2594 aspace = get_regcache_aspace (regcache);
2595 pc = regcache_read_pc (regcache);
2596 tp = inferior_thread ();
2598 /* Fill in with reasonable starting values. */
2599 init_thread_stepping_state (tp);
2601 if (addr == (CORE_ADDR) -1)
2604 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2605 && execution_direction != EXEC_REVERSE)
2606 /* There is a breakpoint at the address we will resume at,
2607 step one instruction before inserting breakpoints so that
2608 we do not stop right away (and report a second hit at this
2611 Note, we don't do this in reverse, because we won't
2612 actually be executing the breakpoint insn anyway.
2613 We'll be (un-)executing the previous instruction. */
2614 tp->stepping_over_breakpoint = 1;
2615 else if (gdbarch_single_step_through_delay_p (gdbarch)
2616 && gdbarch_single_step_through_delay (gdbarch,
2617 get_current_frame ()))
2618 /* We stepped onto an instruction that needs to be stepped
2619 again before re-inserting the breakpoint, do so. */
2620 tp->stepping_over_breakpoint = 1;
2624 regcache_write_pc (regcache, addr);
2627 if (siggnal != GDB_SIGNAL_DEFAULT)
2628 tp->suspend.stop_signal = siggnal;
2630 /* Record the interpreter that issued the execution command that
2631 caused this thread to resume. If the top level interpreter is
2632 MI/async, and the execution command was a CLI command
2633 (next/step/etc.), we'll want to print stop event output to the MI
2634 console channel (the stepped-to line, etc.), as if the user
2635 entered the execution command on a real GDB console. */
2636 inferior_thread ()->control.command_interp = command_interp ();
2639 fprintf_unfiltered (gdb_stdlog,
2640 "infrun: proceed (addr=%s, signal=%s)\n",
2641 paddress (gdbarch, addr),
2642 gdb_signal_to_symbol_string (siggnal));
2645 /* In non-stop, each thread is handled individually. The context
2646 must already be set to the right thread here. */
2650 struct thread_info *step_over;
2652 /* In a multi-threaded task we may select another thread and
2653 then continue or step.
2655 But if the old thread was stopped at a breakpoint, it will
2656 immediately cause another breakpoint stop without any
2657 execution (i.e. it will report a breakpoint hit incorrectly).
2658 So we must step over it first.
2660 Look for a thread other than the current (TP) that reported a
2661 breakpoint hit and hasn't been resumed yet since. */
2662 step_over = find_thread_needs_step_over (tp);
2663 if (step_over != NULL)
2666 fprintf_unfiltered (gdb_stdlog,
2667 "infrun: need to step-over [%s] first\n",
2668 target_pid_to_str (step_over->ptid));
2670 /* Store the prev_pc for the stepping thread too, needed by
2671 switch_back_to_stepping thread. */
2672 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2673 switch_to_thread (step_over->ptid);
2678 /* If we need to step over a breakpoint, and we're not using
2679 displaced stepping to do so, insert all breakpoints (watchpoints,
2680 etc.) but the one we're stepping over, step one instruction, and
2681 then re-insert the breakpoint when that step is finished. */
2682 if (tp->stepping_over_breakpoint && !use_displaced_stepping (gdbarch))
2684 struct regcache *regcache = get_current_regcache ();
2686 set_step_over_info (get_regcache_aspace (regcache),
2687 regcache_read_pc (regcache), 0);
2690 clear_step_over_info ();
2692 insert_breakpoints ();
2694 tp->control.trap_expected = tp->stepping_over_breakpoint;
2696 annotate_starting ();
2698 /* Make sure that output from GDB appears before output from the
2700 gdb_flush (gdb_stdout);
2702 /* Refresh prev_pc value just prior to resuming. This used to be
2703 done in stop_waiting, however, setting prev_pc there did not handle
2704 scenarios such as inferior function calls or returning from
2705 a function via the return command. In those cases, the prev_pc
2706 value was not set properly for subsequent commands. The prev_pc value
2707 is used to initialize the starting line number in the ecs. With an
2708 invalid value, the gdb next command ends up stopping at the position
2709 represented by the next line table entry past our start position.
2710 On platforms that generate one line table entry per line, this
2711 is not a problem. However, on the ia64, the compiler generates
2712 extraneous line table entries that do not increase the line number.
2713 When we issue the gdb next command on the ia64 after an inferior call
2714 or a return command, we often end up a few instructions forward, still
2715 within the original line we started.
2717 An attempt was made to refresh the prev_pc at the same time the
2718 execution_control_state is initialized (for instance, just before
2719 waiting for an inferior event). But this approach did not work
2720 because of platforms that use ptrace, where the pc register cannot
2721 be read unless the inferior is stopped. At that point, we are not
2722 guaranteed the inferior is stopped and so the regcache_read_pc() call
2723 can fail. Setting the prev_pc value here ensures the value is updated
2724 correctly when the inferior is stopped. */
2725 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2727 /* Resume inferior. */
2728 resume (tp->suspend.stop_signal);
2730 /* Wait for it to stop (if not standalone)
2731 and in any case decode why it stopped, and act accordingly. */
2732 /* Do this only if we are not using the event loop, or if the target
2733 does not support asynchronous execution. */
2734 if (!target_can_async_p ())
2736 wait_for_inferior ();
2742 /* Start remote-debugging of a machine over a serial link. */
2745 start_remote (int from_tty)
2747 struct inferior *inferior;
2749 inferior = current_inferior ();
2750 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2752 /* Always go on waiting for the target, regardless of the mode. */
2753 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2754 indicate to wait_for_inferior that a target should timeout if
2755 nothing is returned (instead of just blocking). Because of this,
2756 targets expecting an immediate response need to, internally, set
2757 things up so that the target_wait() is forced to eventually
2759 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2760 differentiate to its caller what the state of the target is after
2761 the initial open has been performed. Here we're assuming that
2762 the target has stopped. It should be possible to eventually have
2763 target_open() return to the caller an indication that the target
2764 is currently running and GDB state should be set to the same as
2765 for an async run. */
2766 wait_for_inferior ();
2768 /* Now that the inferior has stopped, do any bookkeeping like
2769 loading shared libraries. We want to do this before normal_stop,
2770 so that the displayed frame is up to date. */
2771 post_create_inferior (¤t_target, from_tty);
2776 /* Initialize static vars when a new inferior begins. */
2779 init_wait_for_inferior (void)
2781 /* These are meaningless until the first time through wait_for_inferior. */
2783 breakpoint_init_inferior (inf_starting);
2785 clear_proceed_status (0);
2787 target_last_wait_ptid = minus_one_ptid;
2789 previous_inferior_ptid = inferior_ptid;
2791 /* Discard any skipped inlined frames. */
2792 clear_inline_frame_state (minus_one_ptid);
2796 /* Data to be passed around while handling an event. This data is
2797 discarded between events. */
2798 struct execution_control_state
2801 /* The thread that got the event, if this was a thread event; NULL
2803 struct thread_info *event_thread;
2805 struct target_waitstatus ws;
2806 int stop_func_filled_in;
2807 CORE_ADDR stop_func_start;
2808 CORE_ADDR stop_func_end;
2809 const char *stop_func_name;
2812 /* True if the event thread hit the single-step breakpoint of
2813 another thread. Thus the event doesn't cause a stop, the thread
2814 needs to be single-stepped past the single-step breakpoint before
2815 we can switch back to the original stepping thread. */
2816 int hit_singlestep_breakpoint;
2819 static void handle_inferior_event (struct execution_control_state *ecs);
2821 static void handle_step_into_function (struct gdbarch *gdbarch,
2822 struct execution_control_state *ecs);
2823 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2824 struct execution_control_state *ecs);
2825 static void handle_signal_stop (struct execution_control_state *ecs);
2826 static void check_exception_resume (struct execution_control_state *,
2827 struct frame_info *);
2829 static void end_stepping_range (struct execution_control_state *ecs);
2830 static void stop_waiting (struct execution_control_state *ecs);
2831 static void prepare_to_wait (struct execution_control_state *ecs);
2832 static void keep_going (struct execution_control_state *ecs);
2833 static void process_event_stop_test (struct execution_control_state *ecs);
2834 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
2836 /* Callback for iterate over threads. If the thread is stopped, but
2837 the user/frontend doesn't know about that yet, go through
2838 normal_stop, as if the thread had just stopped now. ARG points at
2839 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2840 ptid_is_pid(PTID) is true, applies to all threads of the process
2841 pointed at by PTID. Otherwise, apply only to the thread pointed by
2845 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2847 ptid_t ptid = * (ptid_t *) arg;
2849 if ((ptid_equal (info->ptid, ptid)
2850 || ptid_equal (minus_one_ptid, ptid)
2851 || (ptid_is_pid (ptid)
2852 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2853 && is_running (info->ptid)
2854 && !is_executing (info->ptid))
2856 struct cleanup *old_chain;
2857 struct execution_control_state ecss;
2858 struct execution_control_state *ecs = &ecss;
2860 memset (ecs, 0, sizeof (*ecs));
2862 old_chain = make_cleanup_restore_current_thread ();
2864 overlay_cache_invalid = 1;
2865 /* Flush target cache before starting to handle each event.
2866 Target was running and cache could be stale. This is just a
2867 heuristic. Running threads may modify target memory, but we
2868 don't get any event. */
2869 target_dcache_invalidate ();
2871 /* Go through handle_inferior_event/normal_stop, so we always
2872 have consistent output as if the stop event had been
2874 ecs->ptid = info->ptid;
2875 ecs->event_thread = find_thread_ptid (info->ptid);
2876 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2877 ecs->ws.value.sig = GDB_SIGNAL_0;
2879 handle_inferior_event (ecs);
2881 if (!ecs->wait_some_more)
2883 struct thread_info *tp;
2887 /* Finish off the continuations. */
2888 tp = inferior_thread ();
2889 do_all_intermediate_continuations_thread (tp, 1);
2890 do_all_continuations_thread (tp, 1);
2893 do_cleanups (old_chain);
2899 /* This function is attached as a "thread_stop_requested" observer.
2900 Cleanup local state that assumed the PTID was to be resumed, and
2901 report the stop to the frontend. */
2904 infrun_thread_stop_requested (ptid_t ptid)
2906 struct displaced_step_inferior_state *displaced;
2908 /* PTID was requested to stop. Remove it from the displaced
2909 stepping queue, so we don't try to resume it automatically. */
2911 for (displaced = displaced_step_inferior_states;
2913 displaced = displaced->next)
2915 struct displaced_step_request *it, **prev_next_p;
2917 it = displaced->step_request_queue;
2918 prev_next_p = &displaced->step_request_queue;
2921 if (ptid_match (it->ptid, ptid))
2923 *prev_next_p = it->next;
2929 prev_next_p = &it->next;
2936 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2940 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2942 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2943 nullify_last_target_wait_ptid ();
2946 /* Delete the step resume, single-step and longjmp/exception resume
2947 breakpoints of TP. */
2950 delete_thread_infrun_breakpoints (struct thread_info *tp)
2952 delete_step_resume_breakpoint (tp);
2953 delete_exception_resume_breakpoint (tp);
2954 delete_single_step_breakpoints (tp);
2957 /* If the target still has execution, call FUNC for each thread that
2958 just stopped. In all-stop, that's all the non-exited threads; in
2959 non-stop, that's the current thread, only. */
2961 typedef void (*for_each_just_stopped_thread_callback_func)
2962 (struct thread_info *tp);
2965 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
2967 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
2972 /* If in non-stop mode, only the current thread stopped. */
2973 func (inferior_thread ());
2977 struct thread_info *tp;
2979 /* In all-stop mode, all threads have stopped. */
2980 ALL_NON_EXITED_THREADS (tp)
2987 /* Delete the step resume and longjmp/exception resume breakpoints of
2988 the threads that just stopped. */
2991 delete_just_stopped_threads_infrun_breakpoints (void)
2993 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
2996 /* Delete the single-step breakpoints of the threads that just
3000 delete_just_stopped_threads_single_step_breakpoints (void)
3002 for_each_just_stopped_thread (delete_single_step_breakpoints);
3005 /* A cleanup wrapper. */
3008 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3010 delete_just_stopped_threads_infrun_breakpoints ();
3013 /* Pretty print the results of target_wait, for debugging purposes. */
3016 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3017 const struct target_waitstatus *ws)
3019 char *status_string = target_waitstatus_to_string (ws);
3020 struct ui_file *tmp_stream = mem_fileopen ();
3023 /* The text is split over several lines because it was getting too long.
3024 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3025 output as a unit; we want only one timestamp printed if debug_timestamp
3028 fprintf_unfiltered (tmp_stream,
3029 "infrun: target_wait (%d", ptid_get_pid (waiton_ptid));
3030 if (ptid_get_pid (waiton_ptid) != -1)
3031 fprintf_unfiltered (tmp_stream,
3032 " [%s]", target_pid_to_str (waiton_ptid));
3033 fprintf_unfiltered (tmp_stream, ", status) =\n");
3034 fprintf_unfiltered (tmp_stream,
3035 "infrun: %d [%s],\n",
3036 ptid_get_pid (result_ptid),
3037 target_pid_to_str (result_ptid));
3038 fprintf_unfiltered (tmp_stream,
3042 text = ui_file_xstrdup (tmp_stream, NULL);
3044 /* This uses %s in part to handle %'s in the text, but also to avoid
3045 a gcc error: the format attribute requires a string literal. */
3046 fprintf_unfiltered (gdb_stdlog, "%s", text);
3048 xfree (status_string);
3050 ui_file_delete (tmp_stream);
3053 /* Prepare and stabilize the inferior for detaching it. E.g.,
3054 detaching while a thread is displaced stepping is a recipe for
3055 crashing it, as nothing would readjust the PC out of the scratch
3059 prepare_for_detach (void)
3061 struct inferior *inf = current_inferior ();
3062 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3063 struct cleanup *old_chain_1;
3064 struct displaced_step_inferior_state *displaced;
3066 displaced = get_displaced_stepping_state (inf->pid);
3068 /* Is any thread of this process displaced stepping? If not,
3069 there's nothing else to do. */
3070 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3074 fprintf_unfiltered (gdb_stdlog,
3075 "displaced-stepping in-process while detaching");
3077 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3080 while (!ptid_equal (displaced->step_ptid, null_ptid))
3082 struct cleanup *old_chain_2;
3083 struct execution_control_state ecss;
3084 struct execution_control_state *ecs;
3087 memset (ecs, 0, sizeof (*ecs));
3089 overlay_cache_invalid = 1;
3090 /* Flush target cache before starting to handle each event.
3091 Target was running and cache could be stale. This is just a
3092 heuristic. Running threads may modify target memory, but we
3093 don't get any event. */
3094 target_dcache_invalidate ();
3096 if (deprecated_target_wait_hook)
3097 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
3099 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
3102 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3104 /* If an error happens while handling the event, propagate GDB's
3105 knowledge of the executing state to the frontend/user running
3107 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3110 /* Now figure out what to do with the result of the result. */
3111 handle_inferior_event (ecs);
3113 /* No error, don't finish the state yet. */
3114 discard_cleanups (old_chain_2);
3116 /* Breakpoints and watchpoints are not installed on the target
3117 at this point, and signals are passed directly to the
3118 inferior, so this must mean the process is gone. */
3119 if (!ecs->wait_some_more)
3121 discard_cleanups (old_chain_1);
3122 error (_("Program exited while detaching"));
3126 discard_cleanups (old_chain_1);
3129 /* Wait for control to return from inferior to debugger.
3131 If inferior gets a signal, we may decide to start it up again
3132 instead of returning. That is why there is a loop in this function.
3133 When this function actually returns it means the inferior
3134 should be left stopped and GDB should read more commands. */
3137 wait_for_inferior (void)
3139 struct cleanup *old_cleanups;
3143 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3146 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3151 struct execution_control_state ecss;
3152 struct execution_control_state *ecs = &ecss;
3153 struct cleanup *old_chain;
3154 ptid_t waiton_ptid = minus_one_ptid;
3156 memset (ecs, 0, sizeof (*ecs));
3158 overlay_cache_invalid = 1;
3160 /* Flush target cache before starting to handle each event.
3161 Target was running and cache could be stale. This is just a
3162 heuristic. Running threads may modify target memory, but we
3163 don't get any event. */
3164 target_dcache_invalidate ();
3166 if (deprecated_target_wait_hook)
3167 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
3169 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
3172 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3174 /* If an error happens while handling the event, propagate GDB's
3175 knowledge of the executing state to the frontend/user running
3177 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3179 /* Now figure out what to do with the result of the result. */
3180 handle_inferior_event (ecs);
3182 /* No error, don't finish the state yet. */
3183 discard_cleanups (old_chain);
3185 if (!ecs->wait_some_more)
3189 do_cleanups (old_cleanups);
3192 /* Cleanup that reinstalls the readline callback handler, if the
3193 target is running in the background. If while handling the target
3194 event something triggered a secondary prompt, like e.g., a
3195 pagination prompt, we'll have removed the callback handler (see
3196 gdb_readline_wrapper_line). Need to do this as we go back to the
3197 event loop, ready to process further input. Note this has no
3198 effect if the handler hasn't actually been removed, because calling
3199 rl_callback_handler_install resets the line buffer, thus losing
3203 reinstall_readline_callback_handler_cleanup (void *arg)
3205 if (!interpreter_async)
3207 /* We're not going back to the top level event loop yet. Don't
3208 install the readline callback, as it'd prep the terminal,
3209 readline-style (raw, noecho) (e.g., --batch). We'll install
3210 it the next time the prompt is displayed, when we're ready
3215 if (async_command_editing_p && !sync_execution)
3216 gdb_rl_callback_handler_reinstall ();
3219 /* Asynchronous version of wait_for_inferior. It is called by the
3220 event loop whenever a change of state is detected on the file
3221 descriptor corresponding to the target. It can be called more than
3222 once to complete a single execution command. In such cases we need
3223 to keep the state in a global variable ECSS. If it is the last time
3224 that this function is called for a single execution command, then
3225 report to the user that the inferior has stopped, and do the
3226 necessary cleanups. */
3229 fetch_inferior_event (void *client_data)
3231 struct execution_control_state ecss;
3232 struct execution_control_state *ecs = &ecss;
3233 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3234 struct cleanup *ts_old_chain;
3235 int was_sync = sync_execution;
3237 ptid_t waiton_ptid = minus_one_ptid;
3239 memset (ecs, 0, sizeof (*ecs));
3241 /* End up with readline processing input, if necessary. */
3242 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3244 /* We're handling a live event, so make sure we're doing live
3245 debugging. If we're looking at traceframes while the target is
3246 running, we're going to need to get back to that mode after
3247 handling the event. */
3250 make_cleanup_restore_current_traceframe ();
3251 set_current_traceframe (-1);
3255 /* In non-stop mode, the user/frontend should not notice a thread
3256 switch due to internal events. Make sure we reverse to the
3257 user selected thread and frame after handling the event and
3258 running any breakpoint commands. */
3259 make_cleanup_restore_current_thread ();
3261 overlay_cache_invalid = 1;
3262 /* Flush target cache before starting to handle each event. Target
3263 was running and cache could be stale. This is just a heuristic.
3264 Running threads may modify target memory, but we don't get any
3266 target_dcache_invalidate ();
3268 make_cleanup_restore_integer (&execution_direction);
3269 execution_direction = target_execution_direction ();
3271 if (deprecated_target_wait_hook)
3273 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3275 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3278 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3280 /* If an error happens while handling the event, propagate GDB's
3281 knowledge of the executing state to the frontend/user running
3284 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3286 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3288 /* Get executed before make_cleanup_restore_current_thread above to apply
3289 still for the thread which has thrown the exception. */
3290 make_bpstat_clear_actions_cleanup ();
3292 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3294 /* Now figure out what to do with the result of the result. */
3295 handle_inferior_event (ecs);
3297 if (!ecs->wait_some_more)
3299 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3301 delete_just_stopped_threads_infrun_breakpoints ();
3303 /* We may not find an inferior if this was a process exit. */
3304 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3307 if (target_has_execution
3308 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
3309 && ecs->ws.kind != TARGET_WAITKIND_EXITED
3310 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3311 && ecs->event_thread->step_multi
3312 && ecs->event_thread->control.stop_step)
3313 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
3316 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3321 /* No error, don't finish the thread states yet. */
3322 discard_cleanups (ts_old_chain);
3324 /* Revert thread and frame. */
3325 do_cleanups (old_chain);
3327 /* If the inferior was in sync execution mode, and now isn't,
3328 restore the prompt (a synchronous execution command has finished,
3329 and we're ready for input). */
3330 if (interpreter_async && was_sync && !sync_execution)
3331 observer_notify_sync_execution_done ();
3335 && exec_done_display_p
3336 && (ptid_equal (inferior_ptid, null_ptid)
3337 || !is_running (inferior_ptid)))
3338 printf_unfiltered (_("completed.\n"));
3341 /* Record the frame and location we're currently stepping through. */
3343 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3345 struct thread_info *tp = inferior_thread ();
3347 tp->control.step_frame_id = get_frame_id (frame);
3348 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3350 tp->current_symtab = sal.symtab;
3351 tp->current_line = sal.line;
3354 /* Clear context switchable stepping state. */
3357 init_thread_stepping_state (struct thread_info *tss)
3359 tss->stepped_breakpoint = 0;
3360 tss->stepping_over_breakpoint = 0;
3361 tss->stepping_over_watchpoint = 0;
3362 tss->step_after_step_resume_breakpoint = 0;
3365 /* Set the cached copy of the last ptid/waitstatus. */
3368 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3370 target_last_wait_ptid = ptid;
3371 target_last_waitstatus = status;
3374 /* Return the cached copy of the last pid/waitstatus returned by
3375 target_wait()/deprecated_target_wait_hook(). The data is actually
3376 cached by handle_inferior_event(), which gets called immediately
3377 after target_wait()/deprecated_target_wait_hook(). */
3380 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3382 *ptidp = target_last_wait_ptid;
3383 *status = target_last_waitstatus;
3387 nullify_last_target_wait_ptid (void)
3389 target_last_wait_ptid = minus_one_ptid;
3392 /* Switch thread contexts. */
3395 context_switch (ptid_t ptid)
3397 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
3399 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3400 target_pid_to_str (inferior_ptid));
3401 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3402 target_pid_to_str (ptid));
3405 switch_to_thread (ptid);
3409 adjust_pc_after_break (struct execution_control_state *ecs)
3411 struct regcache *regcache;
3412 struct gdbarch *gdbarch;
3413 struct address_space *aspace;
3414 CORE_ADDR breakpoint_pc, decr_pc;
3416 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3417 we aren't, just return.
3419 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3420 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3421 implemented by software breakpoints should be handled through the normal
3424 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3425 different signals (SIGILL or SIGEMT for instance), but it is less
3426 clear where the PC is pointing afterwards. It may not match
3427 gdbarch_decr_pc_after_break. I don't know any specific target that
3428 generates these signals at breakpoints (the code has been in GDB since at
3429 least 1992) so I can not guess how to handle them here.
3431 In earlier versions of GDB, a target with
3432 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3433 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3434 target with both of these set in GDB history, and it seems unlikely to be
3435 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3437 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
3440 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
3443 /* In reverse execution, when a breakpoint is hit, the instruction
3444 under it has already been de-executed. The reported PC always
3445 points at the breakpoint address, so adjusting it further would
3446 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3449 B1 0x08000000 : INSN1
3450 B2 0x08000001 : INSN2
3452 PC -> 0x08000003 : INSN4
3454 Say you're stopped at 0x08000003 as above. Reverse continuing
3455 from that point should hit B2 as below. Reading the PC when the
3456 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3457 been de-executed already.
3459 B1 0x08000000 : INSN1
3460 B2 PC -> 0x08000001 : INSN2
3464 We can't apply the same logic as for forward execution, because
3465 we would wrongly adjust the PC to 0x08000000, since there's a
3466 breakpoint at PC - 1. We'd then report a hit on B1, although
3467 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3469 if (execution_direction == EXEC_REVERSE)
3472 /* If the target can tell whether the thread hit a SW breakpoint,
3473 trust it. Targets that can tell also adjust the PC
3475 if (target_supports_stopped_by_sw_breakpoint ())
3478 /* Note that relying on whether a breakpoint is planted in memory to
3479 determine this can fail. E.g,. the breakpoint could have been
3480 removed since. Or the thread could have been told to step an
3481 instruction the size of a breakpoint instruction, and only
3482 _after_ was a breakpoint inserted at its address. */
3484 /* If this target does not decrement the PC after breakpoints, then
3485 we have nothing to do. */
3486 regcache = get_thread_regcache (ecs->ptid);
3487 gdbarch = get_regcache_arch (regcache);
3489 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3493 aspace = get_regcache_aspace (regcache);
3495 /* Find the location where (if we've hit a breakpoint) the
3496 breakpoint would be. */
3497 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3499 /* If the target can't tell whether a software breakpoint triggered,
3500 fallback to figuring it out based on breakpoints we think were
3501 inserted in the target, and on whether the thread was stepped or
3504 /* Check whether there actually is a software breakpoint inserted at
3507 If in non-stop mode, a race condition is possible where we've
3508 removed a breakpoint, but stop events for that breakpoint were
3509 already queued and arrive later. To suppress those spurious
3510 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3511 and retire them after a number of stop events are reported. Note
3512 this is an heuristic and can thus get confused. The real fix is
3513 to get the "stopped by SW BP and needs adjustment" info out of
3514 the target/kernel (and thus never reach here; see above). */
3515 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3516 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3518 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
3520 if (record_full_is_used ())
3521 record_full_gdb_operation_disable_set ();
3523 /* When using hardware single-step, a SIGTRAP is reported for both
3524 a completed single-step and a software breakpoint. Need to
3525 differentiate between the two, as the latter needs adjusting
3526 but the former does not.
3528 The SIGTRAP can be due to a completed hardware single-step only if
3529 - we didn't insert software single-step breakpoints
3530 - this thread is currently being stepped
3532 If any of these events did not occur, we must have stopped due
3533 to hitting a software breakpoint, and have to back up to the
3536 As a special case, we could have hardware single-stepped a
3537 software breakpoint. In this case (prev_pc == breakpoint_pc),
3538 we also need to back up to the breakpoint address. */
3540 if (thread_has_single_step_breakpoints_set (ecs->event_thread)
3541 || !currently_stepping (ecs->event_thread)
3542 || (ecs->event_thread->stepped_breakpoint
3543 && ecs->event_thread->prev_pc == breakpoint_pc))
3544 regcache_write_pc (regcache, breakpoint_pc);
3546 do_cleanups (old_cleanups);
3551 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3553 for (frame = get_prev_frame (frame);
3555 frame = get_prev_frame (frame))
3557 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3559 if (get_frame_type (frame) != INLINE_FRAME)
3566 /* Auxiliary function that handles syscall entry/return events.
3567 It returns 1 if the inferior should keep going (and GDB
3568 should ignore the event), or 0 if the event deserves to be
3572 handle_syscall_event (struct execution_control_state *ecs)
3574 struct regcache *regcache;
3577 if (!ptid_equal (ecs->ptid, inferior_ptid))
3578 context_switch (ecs->ptid);
3580 regcache = get_thread_regcache (ecs->ptid);
3581 syscall_number = ecs->ws.value.syscall_number;
3582 stop_pc = regcache_read_pc (regcache);
3584 if (catch_syscall_enabled () > 0
3585 && catching_syscall_number (syscall_number) > 0)
3588 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3591 ecs->event_thread->control.stop_bpstat
3592 = bpstat_stop_status (get_regcache_aspace (regcache),
3593 stop_pc, ecs->ptid, &ecs->ws);
3595 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3597 /* Catchpoint hit. */
3602 /* If no catchpoint triggered for this, then keep going. */
3607 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3610 fill_in_stop_func (struct gdbarch *gdbarch,
3611 struct execution_control_state *ecs)
3613 if (!ecs->stop_func_filled_in)
3615 /* Don't care about return value; stop_func_start and stop_func_name
3616 will both be 0 if it doesn't work. */
3617 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3618 &ecs->stop_func_start, &ecs->stop_func_end);
3619 ecs->stop_func_start
3620 += gdbarch_deprecated_function_start_offset (gdbarch);
3622 if (gdbarch_skip_entrypoint_p (gdbarch))
3623 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
3624 ecs->stop_func_start);
3626 ecs->stop_func_filled_in = 1;
3631 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
3633 static enum stop_kind
3634 get_inferior_stop_soon (ptid_t ptid)
3636 struct inferior *inf = find_inferior_ptid (ptid);
3638 gdb_assert (inf != NULL);
3639 return inf->control.stop_soon;
3642 /* Given an execution control state that has been freshly filled in by
3643 an event from the inferior, figure out what it means and take
3646 The alternatives are:
3648 1) stop_waiting and return; to really stop and return to the
3651 2) keep_going and return; to wait for the next event (set
3652 ecs->event_thread->stepping_over_breakpoint to 1 to single step
3656 handle_inferior_event (struct execution_control_state *ecs)
3658 enum stop_kind stop_soon;
3660 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3662 /* We had an event in the inferior, but we are not interested in
3663 handling it at this level. The lower layers have already
3664 done what needs to be done, if anything.
3666 One of the possible circumstances for this is when the
3667 inferior produces output for the console. The inferior has
3668 not stopped, and we are ignoring the event. Another possible
3669 circumstance is any event which the lower level knows will be
3670 reported multiple times without an intervening resume. */
3672 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3673 prepare_to_wait (ecs);
3677 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3678 && target_can_async_p () && !sync_execution)
3680 /* There were no unwaited-for children left in the target, but,
3681 we're not synchronously waiting for events either. Just
3682 ignore. Otherwise, if we were running a synchronous
3683 execution command, we need to cancel it and give the user
3684 back the terminal. */
3686 fprintf_unfiltered (gdb_stdlog,
3687 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3688 prepare_to_wait (ecs);
3692 /* Cache the last pid/waitstatus. */
3693 set_last_target_status (ecs->ptid, ecs->ws);
3695 /* Always clear state belonging to the previous time we stopped. */
3696 stop_stack_dummy = STOP_NONE;
3698 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3700 /* No unwaited-for children left. IOW, all resumed children
3703 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3705 stop_print_frame = 0;
3710 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3711 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3713 ecs->event_thread = find_thread_ptid (ecs->ptid);
3714 /* If it's a new thread, add it to the thread database. */
3715 if (ecs->event_thread == NULL)
3716 ecs->event_thread = add_thread (ecs->ptid);
3718 /* Disable range stepping. If the next step request could use a
3719 range, this will be end up re-enabled then. */
3720 ecs->event_thread->control.may_range_step = 0;
3723 /* Dependent on valid ECS->EVENT_THREAD. */
3724 adjust_pc_after_break (ecs);
3726 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3727 reinit_frame_cache ();
3729 breakpoint_retire_moribund ();
3731 /* First, distinguish signals caused by the debugger from signals
3732 that have to do with the program's own actions. Note that
3733 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3734 on the operating system version. Here we detect when a SIGILL or
3735 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3736 something similar for SIGSEGV, since a SIGSEGV will be generated
3737 when we're trying to execute a breakpoint instruction on a
3738 non-executable stack. This happens for call dummy breakpoints
3739 for architectures like SPARC that place call dummies on the
3741 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3742 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3743 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3744 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3746 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3748 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3749 regcache_read_pc (regcache)))
3752 fprintf_unfiltered (gdb_stdlog,
3753 "infrun: Treating signal as SIGTRAP\n");
3754 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3758 /* Mark the non-executing threads accordingly. In all-stop, all
3759 threads of all processes are stopped when we get any event
3760 reported. In non-stop mode, only the event thread stops. If
3761 we're handling a process exit in non-stop mode, there's nothing
3762 to do, as threads of the dead process are gone, and threads of
3763 any other process were left running. */
3765 set_executing (minus_one_ptid, 0);
3766 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3767 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3768 set_executing (ecs->ptid, 0);
3770 switch (ecs->ws.kind)
3772 case TARGET_WAITKIND_LOADED:
3774 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3775 if (!ptid_equal (ecs->ptid, inferior_ptid))
3776 context_switch (ecs->ptid);
3777 /* Ignore gracefully during startup of the inferior, as it might
3778 be the shell which has just loaded some objects, otherwise
3779 add the symbols for the newly loaded objects. Also ignore at
3780 the beginning of an attach or remote session; we will query
3781 the full list of libraries once the connection is
3784 stop_soon = get_inferior_stop_soon (ecs->ptid);
3785 if (stop_soon == NO_STOP_QUIETLY)
3787 struct regcache *regcache;
3789 regcache = get_thread_regcache (ecs->ptid);
3791 handle_solib_event ();
3793 ecs->event_thread->control.stop_bpstat
3794 = bpstat_stop_status (get_regcache_aspace (regcache),
3795 stop_pc, ecs->ptid, &ecs->ws);
3797 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3799 /* A catchpoint triggered. */
3800 process_event_stop_test (ecs);
3804 /* If requested, stop when the dynamic linker notifies
3805 gdb of events. This allows the user to get control
3806 and place breakpoints in initializer routines for
3807 dynamically loaded objects (among other things). */
3808 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3809 if (stop_on_solib_events)
3811 /* Make sure we print "Stopped due to solib-event" in
3813 stop_print_frame = 1;
3820 /* If we are skipping through a shell, or through shared library
3821 loading that we aren't interested in, resume the program. If
3822 we're running the program normally, also resume. */
3823 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3825 /* Loading of shared libraries might have changed breakpoint
3826 addresses. Make sure new breakpoints are inserted. */
3827 if (stop_soon == NO_STOP_QUIETLY)
3828 insert_breakpoints ();
3829 resume (GDB_SIGNAL_0);
3830 prepare_to_wait (ecs);
3834 /* But stop if we're attaching or setting up a remote
3836 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
3837 || stop_soon == STOP_QUIETLY_REMOTE)
3840 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
3845 internal_error (__FILE__, __LINE__,
3846 _("unhandled stop_soon: %d"), (int) stop_soon);
3848 case TARGET_WAITKIND_SPURIOUS:
3850 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3851 if (!ptid_equal (ecs->ptid, inferior_ptid))
3852 context_switch (ecs->ptid);
3853 resume (GDB_SIGNAL_0);
3854 prepare_to_wait (ecs);
3857 case TARGET_WAITKIND_EXITED:
3858 case TARGET_WAITKIND_SIGNALLED:
3861 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3862 fprintf_unfiltered (gdb_stdlog,
3863 "infrun: TARGET_WAITKIND_EXITED\n");
3865 fprintf_unfiltered (gdb_stdlog,
3866 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3869 inferior_ptid = ecs->ptid;
3870 set_current_inferior (find_inferior_ptid (ecs->ptid));
3871 set_current_program_space (current_inferior ()->pspace);
3872 handle_vfork_child_exec_or_exit (0);
3873 target_terminal_ours (); /* Must do this before mourn anyway. */
3875 /* Clearing any previous state of convenience variables. */
3876 clear_exit_convenience_vars ();
3878 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3880 /* Record the exit code in the convenience variable $_exitcode, so
3881 that the user can inspect this again later. */
3882 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3883 (LONGEST) ecs->ws.value.integer);
3885 /* Also record this in the inferior itself. */
3886 current_inferior ()->has_exit_code = 1;
3887 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3889 /* Support the --return-child-result option. */
3890 return_child_result_value = ecs->ws.value.integer;
3892 observer_notify_exited (ecs->ws.value.integer);
3896 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3897 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3899 if (gdbarch_gdb_signal_to_target_p (gdbarch))
3901 /* Set the value of the internal variable $_exitsignal,
3902 which holds the signal uncaught by the inferior. */
3903 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
3904 gdbarch_gdb_signal_to_target (gdbarch,
3905 ecs->ws.value.sig));
3909 /* We don't have access to the target's method used for
3910 converting between signal numbers (GDB's internal
3911 representation <-> target's representation).
3912 Therefore, we cannot do a good job at displaying this
3913 information to the user. It's better to just warn
3914 her about it (if infrun debugging is enabled), and
3917 fprintf_filtered (gdb_stdlog, _("\
3918 Cannot fill $_exitsignal with the correct signal number.\n"));
3921 observer_notify_signal_exited (ecs->ws.value.sig);
3924 gdb_flush (gdb_stdout);
3925 target_mourn_inferior ();
3926 stop_print_frame = 0;
3930 /* The following are the only cases in which we keep going;
3931 the above cases end in a continue or goto. */
3932 case TARGET_WAITKIND_FORKED:
3933 case TARGET_WAITKIND_VFORKED:
3936 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3937 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3939 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3942 /* Check whether the inferior is displaced stepping. */
3944 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3945 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3946 struct displaced_step_inferior_state *displaced
3947 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3949 /* If checking displaced stepping is supported, and thread
3950 ecs->ptid is displaced stepping. */
3951 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3953 struct inferior *parent_inf
3954 = find_inferior_ptid (ecs->ptid);
3955 struct regcache *child_regcache;
3956 CORE_ADDR parent_pc;
3958 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3959 indicating that the displaced stepping of syscall instruction
3960 has been done. Perform cleanup for parent process here. Note
3961 that this operation also cleans up the child process for vfork,
3962 because their pages are shared. */
3963 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3965 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3967 /* Restore scratch pad for child process. */
3968 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3971 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3972 the child's PC is also within the scratchpad. Set the child's PC
3973 to the parent's PC value, which has already been fixed up.
3974 FIXME: we use the parent's aspace here, although we're touching
3975 the child, because the child hasn't been added to the inferior
3976 list yet at this point. */
3979 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3981 parent_inf->aspace);
3982 /* Read PC value of parent process. */
3983 parent_pc = regcache_read_pc (regcache);
3985 if (debug_displaced)
3986 fprintf_unfiltered (gdb_stdlog,
3987 "displaced: write child pc from %s to %s\n",
3989 regcache_read_pc (child_regcache)),
3990 paddress (gdbarch, parent_pc));
3992 regcache_write_pc (child_regcache, parent_pc);
3996 if (!ptid_equal (ecs->ptid, inferior_ptid))
3997 context_switch (ecs->ptid);
3999 /* Immediately detach breakpoints from the child before there's
4000 any chance of letting the user delete breakpoints from the
4001 breakpoint lists. If we don't do this early, it's easy to
4002 leave left over traps in the child, vis: "break foo; catch
4003 fork; c; <fork>; del; c; <child calls foo>". We only follow
4004 the fork on the last `continue', and by that time the
4005 breakpoint at "foo" is long gone from the breakpoint table.
4006 If we vforked, then we don't need to unpatch here, since both
4007 parent and child are sharing the same memory pages; we'll
4008 need to unpatch at follow/detach time instead to be certain
4009 that new breakpoints added between catchpoint hit time and
4010 vfork follow are detached. */
4011 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4013 /* This won't actually modify the breakpoint list, but will
4014 physically remove the breakpoints from the child. */
4015 detach_breakpoints (ecs->ws.value.related_pid);
4018 delete_just_stopped_threads_single_step_breakpoints ();
4020 /* In case the event is caught by a catchpoint, remember that
4021 the event is to be followed at the next resume of the thread,
4022 and not immediately. */
4023 ecs->event_thread->pending_follow = ecs->ws;
4025 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4027 ecs->event_thread->control.stop_bpstat
4028 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4029 stop_pc, ecs->ptid, &ecs->ws);
4031 /* If no catchpoint triggered for this, then keep going. Note
4032 that we're interested in knowing the bpstat actually causes a
4033 stop, not just if it may explain the signal. Software
4034 watchpoints, for example, always appear in the bpstat. */
4035 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4041 = (follow_fork_mode_string == follow_fork_mode_child);
4043 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4045 should_resume = follow_fork ();
4048 child = ecs->ws.value.related_pid;
4050 /* In non-stop mode, also resume the other branch. */
4051 if (non_stop && !detach_fork)
4054 switch_to_thread (parent);
4056 switch_to_thread (child);
4058 ecs->event_thread = inferior_thread ();
4059 ecs->ptid = inferior_ptid;
4064 switch_to_thread (child);
4066 switch_to_thread (parent);
4068 ecs->event_thread = inferior_thread ();
4069 ecs->ptid = inferior_ptid;
4077 process_event_stop_test (ecs);
4080 case TARGET_WAITKIND_VFORK_DONE:
4081 /* Done with the shared memory region. Re-insert breakpoints in
4082 the parent, and keep going. */
4085 fprintf_unfiltered (gdb_stdlog,
4086 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
4088 if (!ptid_equal (ecs->ptid, inferior_ptid))
4089 context_switch (ecs->ptid);
4091 current_inferior ()->waiting_for_vfork_done = 0;
4092 current_inferior ()->pspace->breakpoints_not_allowed = 0;
4093 /* This also takes care of reinserting breakpoints in the
4094 previously locked inferior. */
4098 case TARGET_WAITKIND_EXECD:
4100 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
4102 if (!ptid_equal (ecs->ptid, inferior_ptid))
4103 context_switch (ecs->ptid);
4105 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4107 /* Do whatever is necessary to the parent branch of the vfork. */
4108 handle_vfork_child_exec_or_exit (1);
4110 /* This causes the eventpoints and symbol table to be reset.
4111 Must do this now, before trying to determine whether to
4113 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
4115 ecs->event_thread->control.stop_bpstat
4116 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4117 stop_pc, ecs->ptid, &ecs->ws);
4119 /* Note that this may be referenced from inside
4120 bpstat_stop_status above, through inferior_has_execd. */
4121 xfree (ecs->ws.value.execd_pathname);
4122 ecs->ws.value.execd_pathname = NULL;
4124 /* If no catchpoint triggered for this, then keep going. */
4125 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4127 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4131 process_event_stop_test (ecs);
4134 /* Be careful not to try to gather much state about a thread
4135 that's in a syscall. It's frequently a losing proposition. */
4136 case TARGET_WAITKIND_SYSCALL_ENTRY:
4138 fprintf_unfiltered (gdb_stdlog,
4139 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
4140 /* Getting the current syscall number. */
4141 if (handle_syscall_event (ecs) == 0)
4142 process_event_stop_test (ecs);
4145 /* Before examining the threads further, step this thread to
4146 get it entirely out of the syscall. (We get notice of the
4147 event when the thread is just on the verge of exiting a
4148 syscall. Stepping one instruction seems to get it back
4150 case TARGET_WAITKIND_SYSCALL_RETURN:
4152 fprintf_unfiltered (gdb_stdlog,
4153 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
4154 if (handle_syscall_event (ecs) == 0)
4155 process_event_stop_test (ecs);
4158 case TARGET_WAITKIND_STOPPED:
4160 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
4161 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
4162 handle_signal_stop (ecs);
4165 case TARGET_WAITKIND_NO_HISTORY:
4167 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
4168 /* Reverse execution: target ran out of history info. */
4170 delete_just_stopped_threads_single_step_breakpoints ();
4171 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4172 observer_notify_no_history ();
4178 /* Come here when the program has stopped with a signal. */
4181 handle_signal_stop (struct execution_control_state *ecs)
4183 struct frame_info *frame;
4184 struct gdbarch *gdbarch;
4185 int stopped_by_watchpoint;
4186 enum stop_kind stop_soon;
4189 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
4191 /* Do we need to clean up the state of a thread that has
4192 completed a displaced single-step? (Doing so usually affects
4193 the PC, so do it here, before we set stop_pc.) */
4194 displaced_step_fixup (ecs->ptid,
4195 ecs->event_thread->suspend.stop_signal);
4197 /* If we either finished a single-step or hit a breakpoint, but
4198 the user wanted this thread to be stopped, pretend we got a
4199 SIG0 (generic unsignaled stop). */
4200 if (ecs->event_thread->stop_requested
4201 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4202 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4204 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4208 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4209 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4210 struct cleanup *old_chain = save_inferior_ptid ();
4212 inferior_ptid = ecs->ptid;
4214 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
4215 paddress (gdbarch, stop_pc));
4216 if (target_stopped_by_watchpoint ())
4220 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
4222 if (target_stopped_data_address (¤t_target, &addr))
4223 fprintf_unfiltered (gdb_stdlog,
4224 "infrun: stopped data address = %s\n",
4225 paddress (gdbarch, addr));
4227 fprintf_unfiltered (gdb_stdlog,
4228 "infrun: (no data address available)\n");
4231 do_cleanups (old_chain);
4234 /* This is originated from start_remote(), start_inferior() and
4235 shared libraries hook functions. */
4236 stop_soon = get_inferior_stop_soon (ecs->ptid);
4237 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4239 if (!ptid_equal (ecs->ptid, inferior_ptid))
4240 context_switch (ecs->ptid);
4242 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4243 stop_print_frame = 1;
4248 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4251 if (!ptid_equal (ecs->ptid, inferior_ptid))
4252 context_switch (ecs->ptid);
4254 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4255 stop_print_frame = 0;
4260 /* This originates from attach_command(). We need to overwrite
4261 the stop_signal here, because some kernels don't ignore a
4262 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4263 See more comments in inferior.h. On the other hand, if we
4264 get a non-SIGSTOP, report it to the user - assume the backend
4265 will handle the SIGSTOP if it should show up later.
4267 Also consider that the attach is complete when we see a
4268 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4269 target extended-remote report it instead of a SIGSTOP
4270 (e.g. gdbserver). We already rely on SIGTRAP being our
4271 signal, so this is no exception.
4273 Also consider that the attach is complete when we see a
4274 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4275 the target to stop all threads of the inferior, in case the
4276 low level attach operation doesn't stop them implicitly. If
4277 they weren't stopped implicitly, then the stub will report a
4278 GDB_SIGNAL_0, meaning: stopped for no particular reason
4279 other than GDB's request. */
4280 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4281 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4282 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4283 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4285 stop_print_frame = 1;
4287 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4291 /* See if something interesting happened to the non-current thread. If
4292 so, then switch to that thread. */
4293 if (!ptid_equal (ecs->ptid, inferior_ptid))
4296 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
4298 context_switch (ecs->ptid);
4300 if (deprecated_context_hook)
4301 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
4304 /* At this point, get hold of the now-current thread's frame. */
4305 frame = get_current_frame ();
4306 gdbarch = get_frame_arch (frame);
4308 /* Pull the single step breakpoints out of the target. */
4309 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4311 struct regcache *regcache;
4312 struct address_space *aspace;
4315 regcache = get_thread_regcache (ecs->ptid);
4316 aspace = get_regcache_aspace (regcache);
4317 pc = regcache_read_pc (regcache);
4319 /* However, before doing so, if this single-step breakpoint was
4320 actually for another thread, set this thread up for moving
4322 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
4325 if (single_step_breakpoint_inserted_here_p (aspace, pc))
4329 fprintf_unfiltered (gdb_stdlog,
4330 "infrun: [%s] hit another thread's "
4331 "single-step breakpoint\n",
4332 target_pid_to_str (ecs->ptid));
4334 ecs->hit_singlestep_breakpoint = 1;
4341 fprintf_unfiltered (gdb_stdlog,
4342 "infrun: [%s] hit its "
4343 "single-step breakpoint\n",
4344 target_pid_to_str (ecs->ptid));
4348 delete_just_stopped_threads_single_step_breakpoints ();
4350 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4351 && ecs->event_thread->control.trap_expected
4352 && ecs->event_thread->stepping_over_watchpoint)
4353 stopped_by_watchpoint = 0;
4355 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4357 /* If necessary, step over this watchpoint. We'll be back to display
4359 if (stopped_by_watchpoint
4360 && (target_have_steppable_watchpoint
4361 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4363 /* At this point, we are stopped at an instruction which has
4364 attempted to write to a piece of memory under control of
4365 a watchpoint. The instruction hasn't actually executed
4366 yet. If we were to evaluate the watchpoint expression
4367 now, we would get the old value, and therefore no change
4368 would seem to have occurred.
4370 In order to make watchpoints work `right', we really need
4371 to complete the memory write, and then evaluate the
4372 watchpoint expression. We do this by single-stepping the
4375 It may not be necessary to disable the watchpoint to step over
4376 it. For example, the PA can (with some kernel cooperation)
4377 single step over a watchpoint without disabling the watchpoint.
4379 It is far more common to need to disable a watchpoint to step
4380 the inferior over it. If we have non-steppable watchpoints,
4381 we must disable the current watchpoint; it's simplest to
4382 disable all watchpoints.
4384 Any breakpoint at PC must also be stepped over -- if there's
4385 one, it will have already triggered before the watchpoint
4386 triggered, and we either already reported it to the user, or
4387 it didn't cause a stop and we called keep_going. In either
4388 case, if there was a breakpoint at PC, we must be trying to
4390 ecs->event_thread->stepping_over_watchpoint = 1;
4395 ecs->event_thread->stepping_over_breakpoint = 0;
4396 ecs->event_thread->stepping_over_watchpoint = 0;
4397 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4398 ecs->event_thread->control.stop_step = 0;
4399 stop_print_frame = 1;
4400 stopped_by_random_signal = 0;
4402 /* Hide inlined functions starting here, unless we just performed stepi or
4403 nexti. After stepi and nexti, always show the innermost frame (not any
4404 inline function call sites). */
4405 if (ecs->event_thread->control.step_range_end != 1)
4407 struct address_space *aspace =
4408 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4410 /* skip_inline_frames is expensive, so we avoid it if we can
4411 determine that the address is one where functions cannot have
4412 been inlined. This improves performance with inferiors that
4413 load a lot of shared libraries, because the solib event
4414 breakpoint is defined as the address of a function (i.e. not
4415 inline). Note that we have to check the previous PC as well
4416 as the current one to catch cases when we have just
4417 single-stepped off a breakpoint prior to reinstating it.
4418 Note that we're assuming that the code we single-step to is
4419 not inline, but that's not definitive: there's nothing
4420 preventing the event breakpoint function from containing
4421 inlined code, and the single-step ending up there. If the
4422 user had set a breakpoint on that inlined code, the missing
4423 skip_inline_frames call would break things. Fortunately
4424 that's an extremely unlikely scenario. */
4425 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4426 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4427 && ecs->event_thread->control.trap_expected
4428 && pc_at_non_inline_function (aspace,
4429 ecs->event_thread->prev_pc,
4432 skip_inline_frames (ecs->ptid);
4434 /* Re-fetch current thread's frame in case that invalidated
4436 frame = get_current_frame ();
4437 gdbarch = get_frame_arch (frame);
4441 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4442 && ecs->event_thread->control.trap_expected
4443 && gdbarch_single_step_through_delay_p (gdbarch)
4444 && currently_stepping (ecs->event_thread))
4446 /* We're trying to step off a breakpoint. Turns out that we're
4447 also on an instruction that needs to be stepped multiple
4448 times before it's been fully executing. E.g., architectures
4449 with a delay slot. It needs to be stepped twice, once for
4450 the instruction and once for the delay slot. */
4451 int step_through_delay
4452 = gdbarch_single_step_through_delay (gdbarch, frame);
4454 if (debug_infrun && step_through_delay)
4455 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4456 if (ecs->event_thread->control.step_range_end == 0
4457 && step_through_delay)
4459 /* The user issued a continue when stopped at a breakpoint.
4460 Set up for another trap and get out of here. */
4461 ecs->event_thread->stepping_over_breakpoint = 1;
4465 else if (step_through_delay)
4467 /* The user issued a step when stopped at a breakpoint.
4468 Maybe we should stop, maybe we should not - the delay
4469 slot *might* correspond to a line of source. In any
4470 case, don't decide that here, just set
4471 ecs->stepping_over_breakpoint, making sure we
4472 single-step again before breakpoints are re-inserted. */
4473 ecs->event_thread->stepping_over_breakpoint = 1;
4477 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4478 handles this event. */
4479 ecs->event_thread->control.stop_bpstat
4480 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4481 stop_pc, ecs->ptid, &ecs->ws);
4483 /* Following in case break condition called a
4485 stop_print_frame = 1;
4487 /* This is where we handle "moribund" watchpoints. Unlike
4488 software breakpoints traps, hardware watchpoint traps are
4489 always distinguishable from random traps. If no high-level
4490 watchpoint is associated with the reported stop data address
4491 anymore, then the bpstat does not explain the signal ---
4492 simply make sure to ignore it if `stopped_by_watchpoint' is
4496 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4497 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4499 && stopped_by_watchpoint)
4500 fprintf_unfiltered (gdb_stdlog,
4501 "infrun: no user watchpoint explains "
4502 "watchpoint SIGTRAP, ignoring\n");
4504 /* NOTE: cagney/2003-03-29: These checks for a random signal
4505 at one stage in the past included checks for an inferior
4506 function call's call dummy's return breakpoint. The original
4507 comment, that went with the test, read:
4509 ``End of a stack dummy. Some systems (e.g. Sony news) give
4510 another signal besides SIGTRAP, so check here as well as
4513 If someone ever tries to get call dummys on a
4514 non-executable stack to work (where the target would stop
4515 with something like a SIGSEGV), then those tests might need
4516 to be re-instated. Given, however, that the tests were only
4517 enabled when momentary breakpoints were not being used, I
4518 suspect that it won't be the case.
4520 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4521 be necessary for call dummies on a non-executable stack on
4524 /* See if the breakpoints module can explain the signal. */
4526 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4527 ecs->event_thread->suspend.stop_signal);
4529 /* Maybe this was a trap for a software breakpoint that has since
4531 if (random_signal && target_stopped_by_sw_breakpoint ())
4533 if (program_breakpoint_here_p (gdbarch, stop_pc))
4535 struct regcache *regcache;
4538 /* Re-adjust PC to what the program would see if GDB was not
4540 regcache = get_thread_regcache (ecs->event_thread->ptid);
4541 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4544 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4546 if (record_full_is_used ())
4547 record_full_gdb_operation_disable_set ();
4549 regcache_write_pc (regcache, stop_pc + decr_pc);
4551 do_cleanups (old_cleanups);
4556 /* A delayed software breakpoint event. Ignore the trap. */
4558 fprintf_unfiltered (gdb_stdlog,
4559 "infrun: delayed software breakpoint "
4560 "trap, ignoring\n");
4565 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
4566 has since been removed. */
4567 if (random_signal && target_stopped_by_hw_breakpoint ())
4569 /* A delayed hardware breakpoint event. Ignore the trap. */
4571 fprintf_unfiltered (gdb_stdlog,
4572 "infrun: delayed hardware breakpoint/watchpoint "
4573 "trap, ignoring\n");
4577 /* If not, perhaps stepping/nexting can. */
4579 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4580 && currently_stepping (ecs->event_thread));
4582 /* Perhaps the thread hit a single-step breakpoint of _another_
4583 thread. Single-step breakpoints are transparent to the
4584 breakpoints module. */
4586 random_signal = !ecs->hit_singlestep_breakpoint;
4588 /* No? Perhaps we got a moribund watchpoint. */
4590 random_signal = !stopped_by_watchpoint;
4592 /* For the program's own signals, act according to
4593 the signal handling tables. */
4597 /* Signal not for debugging purposes. */
4598 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4599 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
4602 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
4603 gdb_signal_to_symbol_string (stop_signal));
4605 stopped_by_random_signal = 1;
4607 /* Always stop on signals if we're either just gaining control
4608 of the program, or the user explicitly requested this thread
4609 to remain stopped. */
4610 if (stop_soon != NO_STOP_QUIETLY
4611 || ecs->event_thread->stop_requested
4613 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4619 /* Notify observers the signal has "handle print" set. Note we
4620 returned early above if stopping; normal_stop handles the
4621 printing in that case. */
4622 if (signal_print[ecs->event_thread->suspend.stop_signal])
4624 /* The signal table tells us to print about this signal. */
4625 target_terminal_ours_for_output ();
4626 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
4627 target_terminal_inferior ();
4630 /* Clear the signal if it should not be passed. */
4631 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4632 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4634 if (ecs->event_thread->prev_pc == stop_pc
4635 && ecs->event_thread->control.trap_expected
4636 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4638 /* We were just starting a new sequence, attempting to
4639 single-step off of a breakpoint and expecting a SIGTRAP.
4640 Instead this signal arrives. This signal will take us out
4641 of the stepping range so GDB needs to remember to, when
4642 the signal handler returns, resume stepping off that
4644 /* To simplify things, "continue" is forced to use the same
4645 code paths as single-step - set a breakpoint at the
4646 signal return address and then, once hit, step off that
4649 fprintf_unfiltered (gdb_stdlog,
4650 "infrun: signal arrived while stepping over "
4653 insert_hp_step_resume_breakpoint_at_frame (frame);
4654 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4655 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4656 ecs->event_thread->control.trap_expected = 0;
4658 /* If we were nexting/stepping some other thread, switch to
4659 it, so that we don't continue it, losing control. */
4660 if (!switch_back_to_stepped_thread (ecs))
4665 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4666 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
4667 || ecs->event_thread->control.step_range_end == 1)
4668 && frame_id_eq (get_stack_frame_id (frame),
4669 ecs->event_thread->control.step_stack_frame_id)
4670 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4672 /* The inferior is about to take a signal that will take it
4673 out of the single step range. Set a breakpoint at the
4674 current PC (which is presumably where the signal handler
4675 will eventually return) and then allow the inferior to
4678 Note that this is only needed for a signal delivered
4679 while in the single-step range. Nested signals aren't a
4680 problem as they eventually all return. */
4682 fprintf_unfiltered (gdb_stdlog,
4683 "infrun: signal may take us out of "
4684 "single-step range\n");
4686 insert_hp_step_resume_breakpoint_at_frame (frame);
4687 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4688 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4689 ecs->event_thread->control.trap_expected = 0;
4694 /* Note: step_resume_breakpoint may be non-NULL. This occures
4695 when either there's a nested signal, or when there's a
4696 pending signal enabled just as the signal handler returns
4697 (leaving the inferior at the step-resume-breakpoint without
4698 actually executing it). Either way continue until the
4699 breakpoint is really hit. */
4701 if (!switch_back_to_stepped_thread (ecs))
4704 fprintf_unfiltered (gdb_stdlog,
4705 "infrun: random signal, keep going\n");
4712 process_event_stop_test (ecs);
4715 /* Come here when we've got some debug event / signal we can explain
4716 (IOW, not a random signal), and test whether it should cause a
4717 stop, or whether we should resume the inferior (transparently).
4718 E.g., could be a breakpoint whose condition evaluates false; we
4719 could be still stepping within the line; etc. */
4722 process_event_stop_test (struct execution_control_state *ecs)
4724 struct symtab_and_line stop_pc_sal;
4725 struct frame_info *frame;
4726 struct gdbarch *gdbarch;
4727 CORE_ADDR jmp_buf_pc;
4728 struct bpstat_what what;
4730 /* Handle cases caused by hitting a breakpoint. */
4732 frame = get_current_frame ();
4733 gdbarch = get_frame_arch (frame);
4735 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4737 if (what.call_dummy)
4739 stop_stack_dummy = what.call_dummy;
4742 /* If we hit an internal event that triggers symbol changes, the
4743 current frame will be invalidated within bpstat_what (e.g., if we
4744 hit an internal solib event). Re-fetch it. */
4745 frame = get_current_frame ();
4746 gdbarch = get_frame_arch (frame);
4748 switch (what.main_action)
4750 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4751 /* If we hit the breakpoint at longjmp while stepping, we
4752 install a momentary breakpoint at the target of the
4756 fprintf_unfiltered (gdb_stdlog,
4757 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4759 ecs->event_thread->stepping_over_breakpoint = 1;
4761 if (what.is_longjmp)
4763 struct value *arg_value;
4765 /* If we set the longjmp breakpoint via a SystemTap probe,
4766 then use it to extract the arguments. The destination PC
4767 is the third argument to the probe. */
4768 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4771 jmp_buf_pc = value_as_address (arg_value);
4772 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
4774 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4775 || !gdbarch_get_longjmp_target (gdbarch,
4776 frame, &jmp_buf_pc))
4779 fprintf_unfiltered (gdb_stdlog,
4780 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4781 "(!gdbarch_get_longjmp_target)\n");
4786 /* Insert a breakpoint at resume address. */
4787 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4790 check_exception_resume (ecs, frame);
4794 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4796 struct frame_info *init_frame;
4798 /* There are several cases to consider.
4800 1. The initiating frame no longer exists. In this case we
4801 must stop, because the exception or longjmp has gone too
4804 2. The initiating frame exists, and is the same as the
4805 current frame. We stop, because the exception or longjmp
4808 3. The initiating frame exists and is different from the
4809 current frame. This means the exception or longjmp has
4810 been caught beneath the initiating frame, so keep going.
4812 4. longjmp breakpoint has been placed just to protect
4813 against stale dummy frames and user is not interested in
4814 stopping around longjmps. */
4817 fprintf_unfiltered (gdb_stdlog,
4818 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4820 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4822 delete_exception_resume_breakpoint (ecs->event_thread);
4824 if (what.is_longjmp)
4826 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
4828 if (!frame_id_p (ecs->event_thread->initiating_frame))
4836 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4840 struct frame_id current_id
4841 = get_frame_id (get_current_frame ());
4842 if (frame_id_eq (current_id,
4843 ecs->event_thread->initiating_frame))
4845 /* Case 2. Fall through. */
4855 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
4857 delete_step_resume_breakpoint (ecs->event_thread);
4859 end_stepping_range (ecs);
4863 case BPSTAT_WHAT_SINGLE:
4865 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4866 ecs->event_thread->stepping_over_breakpoint = 1;
4867 /* Still need to check other stuff, at least the case where we
4868 are stepping and step out of the right range. */
4871 case BPSTAT_WHAT_STEP_RESUME:
4873 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4875 delete_step_resume_breakpoint (ecs->event_thread);
4876 if (ecs->event_thread->control.proceed_to_finish
4877 && execution_direction == EXEC_REVERSE)
4879 struct thread_info *tp = ecs->event_thread;
4881 /* We are finishing a function in reverse, and just hit the
4882 step-resume breakpoint at the start address of the
4883 function, and we're almost there -- just need to back up
4884 by one more single-step, which should take us back to the
4886 tp->control.step_range_start = tp->control.step_range_end = 1;
4890 fill_in_stop_func (gdbarch, ecs);
4891 if (stop_pc == ecs->stop_func_start
4892 && execution_direction == EXEC_REVERSE)
4894 /* We are stepping over a function call in reverse, and just
4895 hit the step-resume breakpoint at the start address of
4896 the function. Go back to single-stepping, which should
4897 take us back to the function call. */
4898 ecs->event_thread->stepping_over_breakpoint = 1;
4904 case BPSTAT_WHAT_STOP_NOISY:
4906 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4907 stop_print_frame = 1;
4909 /* Assume the thread stopped for a breapoint. We'll still check
4910 whether a/the breakpoint is there when the thread is next
4912 ecs->event_thread->stepping_over_breakpoint = 1;
4917 case BPSTAT_WHAT_STOP_SILENT:
4919 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4920 stop_print_frame = 0;
4922 /* Assume the thread stopped for a breapoint. We'll still check
4923 whether a/the breakpoint is there when the thread is next
4925 ecs->event_thread->stepping_over_breakpoint = 1;
4929 case BPSTAT_WHAT_HP_STEP_RESUME:
4931 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4933 delete_step_resume_breakpoint (ecs->event_thread);
4934 if (ecs->event_thread->step_after_step_resume_breakpoint)
4936 /* Back when the step-resume breakpoint was inserted, we
4937 were trying to single-step off a breakpoint. Go back to
4939 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4940 ecs->event_thread->stepping_over_breakpoint = 1;
4946 case BPSTAT_WHAT_KEEP_CHECKING:
4950 /* If we stepped a permanent breakpoint and we had a high priority
4951 step-resume breakpoint for the address we stepped, but we didn't
4952 hit it, then we must have stepped into the signal handler. The
4953 step-resume was only necessary to catch the case of _not_
4954 stepping into the handler, so delete it, and fall through to
4955 checking whether the step finished. */
4956 if (ecs->event_thread->stepped_breakpoint)
4958 struct breakpoint *sr_bp
4959 = ecs->event_thread->control.step_resume_breakpoint;
4961 if (sr_bp->loc->permanent
4962 && sr_bp->type == bp_hp_step_resume
4963 && sr_bp->loc->address == ecs->event_thread->prev_pc)
4966 fprintf_unfiltered (gdb_stdlog,
4967 "infrun: stepped permanent breakpoint, stopped in "
4969 delete_step_resume_breakpoint (ecs->event_thread);
4970 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4974 /* We come here if we hit a breakpoint but should not stop for it.
4975 Possibly we also were stepping and should stop for that. So fall
4976 through and test for stepping. But, if not stepping, do not
4979 /* In all-stop mode, if we're currently stepping but have stopped in
4980 some other thread, we need to switch back to the stepped thread. */
4981 if (switch_back_to_stepped_thread (ecs))
4984 if (ecs->event_thread->control.step_resume_breakpoint)
4987 fprintf_unfiltered (gdb_stdlog,
4988 "infrun: step-resume breakpoint is inserted\n");
4990 /* Having a step-resume breakpoint overrides anything
4991 else having to do with stepping commands until
4992 that breakpoint is reached. */
4997 if (ecs->event_thread->control.step_range_end == 0)
5000 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
5001 /* Likewise if we aren't even stepping. */
5006 /* Re-fetch current thread's frame in case the code above caused
5007 the frame cache to be re-initialized, making our FRAME variable
5008 a dangling pointer. */
5009 frame = get_current_frame ();
5010 gdbarch = get_frame_arch (frame);
5011 fill_in_stop_func (gdbarch, ecs);
5013 /* If stepping through a line, keep going if still within it.
5015 Note that step_range_end is the address of the first instruction
5016 beyond the step range, and NOT the address of the last instruction
5019 Note also that during reverse execution, we may be stepping
5020 through a function epilogue and therefore must detect when
5021 the current-frame changes in the middle of a line. */
5023 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
5024 && (execution_direction != EXEC_REVERSE
5025 || frame_id_eq (get_frame_id (frame),
5026 ecs->event_thread->control.step_frame_id)))
5030 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
5031 paddress (gdbarch, ecs->event_thread->control.step_range_start),
5032 paddress (gdbarch, ecs->event_thread->control.step_range_end));
5034 /* Tentatively re-enable range stepping; `resume' disables it if
5035 necessary (e.g., if we're stepping over a breakpoint or we
5036 have software watchpoints). */
5037 ecs->event_thread->control.may_range_step = 1;
5039 /* When stepping backward, stop at beginning of line range
5040 (unless it's the function entry point, in which case
5041 keep going back to the call point). */
5042 if (stop_pc == ecs->event_thread->control.step_range_start
5043 && stop_pc != ecs->stop_func_start
5044 && execution_direction == EXEC_REVERSE)
5045 end_stepping_range (ecs);
5052 /* We stepped out of the stepping range. */
5054 /* If we are stepping at the source level and entered the runtime
5055 loader dynamic symbol resolution code...
5057 EXEC_FORWARD: we keep on single stepping until we exit the run
5058 time loader code and reach the callee's address.
5060 EXEC_REVERSE: we've already executed the callee (backward), and
5061 the runtime loader code is handled just like any other
5062 undebuggable function call. Now we need only keep stepping
5063 backward through the trampoline code, and that's handled further
5064 down, so there is nothing for us to do here. */
5066 if (execution_direction != EXEC_REVERSE
5067 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5068 && in_solib_dynsym_resolve_code (stop_pc))
5070 CORE_ADDR pc_after_resolver =
5071 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
5074 fprintf_unfiltered (gdb_stdlog,
5075 "infrun: stepped into dynsym resolve code\n");
5077 if (pc_after_resolver)
5079 /* Set up a step-resume breakpoint at the address
5080 indicated by SKIP_SOLIB_RESOLVER. */
5081 struct symtab_and_line sr_sal;
5084 sr_sal.pc = pc_after_resolver;
5085 sr_sal.pspace = get_frame_program_space (frame);
5087 insert_step_resume_breakpoint_at_sal (gdbarch,
5088 sr_sal, null_frame_id);
5095 if (ecs->event_thread->control.step_range_end != 1
5096 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5097 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5098 && get_frame_type (frame) == SIGTRAMP_FRAME)
5101 fprintf_unfiltered (gdb_stdlog,
5102 "infrun: stepped into signal trampoline\n");
5103 /* The inferior, while doing a "step" or "next", has ended up in
5104 a signal trampoline (either by a signal being delivered or by
5105 the signal handler returning). Just single-step until the
5106 inferior leaves the trampoline (either by calling the handler
5112 /* If we're in the return path from a shared library trampoline,
5113 we want to proceed through the trampoline when stepping. */
5114 /* macro/2012-04-25: This needs to come before the subroutine
5115 call check below as on some targets return trampolines look
5116 like subroutine calls (MIPS16 return thunks). */
5117 if (gdbarch_in_solib_return_trampoline (gdbarch,
5118 stop_pc, ecs->stop_func_name)
5119 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5121 /* Determine where this trampoline returns. */
5122 CORE_ADDR real_stop_pc;
5124 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
5127 fprintf_unfiltered (gdb_stdlog,
5128 "infrun: stepped into solib return tramp\n");
5130 /* Only proceed through if we know where it's going. */
5133 /* And put the step-breakpoint there and go until there. */
5134 struct symtab_and_line sr_sal;
5136 init_sal (&sr_sal); /* initialize to zeroes */
5137 sr_sal.pc = real_stop_pc;
5138 sr_sal.section = find_pc_overlay (sr_sal.pc);
5139 sr_sal.pspace = get_frame_program_space (frame);
5141 /* Do not specify what the fp should be when we stop since
5142 on some machines the prologue is where the new fp value
5144 insert_step_resume_breakpoint_at_sal (gdbarch,
5145 sr_sal, null_frame_id);
5147 /* Restart without fiddling with the step ranges or
5154 /* Check for subroutine calls. The check for the current frame
5155 equalling the step ID is not necessary - the check of the
5156 previous frame's ID is sufficient - but it is a common case and
5157 cheaper than checking the previous frame's ID.
5159 NOTE: frame_id_eq will never report two invalid frame IDs as
5160 being equal, so to get into this block, both the current and
5161 previous frame must have valid frame IDs. */
5162 /* The outer_frame_id check is a heuristic to detect stepping
5163 through startup code. If we step over an instruction which
5164 sets the stack pointer from an invalid value to a valid value,
5165 we may detect that as a subroutine call from the mythical
5166 "outermost" function. This could be fixed by marking
5167 outermost frames as !stack_p,code_p,special_p. Then the
5168 initial outermost frame, before sp was valid, would
5169 have code_addr == &_start. See the comment in frame_id_eq
5171 if (!frame_id_eq (get_stack_frame_id (frame),
5172 ecs->event_thread->control.step_stack_frame_id)
5173 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
5174 ecs->event_thread->control.step_stack_frame_id)
5175 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
5177 || (ecs->event_thread->control.step_start_function
5178 != find_pc_function (stop_pc)))))
5180 CORE_ADDR real_stop_pc;
5183 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
5185 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
5187 /* I presume that step_over_calls is only 0 when we're
5188 supposed to be stepping at the assembly language level
5189 ("stepi"). Just stop. */
5190 /* And this works the same backward as frontward. MVS */
5191 end_stepping_range (ecs);
5195 /* Reverse stepping through solib trampolines. */
5197 if (execution_direction == EXEC_REVERSE
5198 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
5199 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5200 || (ecs->stop_func_start == 0
5201 && in_solib_dynsym_resolve_code (stop_pc))))
5203 /* Any solib trampoline code can be handled in reverse
5204 by simply continuing to single-step. We have already
5205 executed the solib function (backwards), and a few
5206 steps will take us back through the trampoline to the
5212 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5214 /* We're doing a "next".
5216 Normal (forward) execution: set a breakpoint at the
5217 callee's return address (the address at which the caller
5220 Reverse (backward) execution. set the step-resume
5221 breakpoint at the start of the function that we just
5222 stepped into (backwards), and continue to there. When we
5223 get there, we'll need to single-step back to the caller. */
5225 if (execution_direction == EXEC_REVERSE)
5227 /* If we're already at the start of the function, we've either
5228 just stepped backward into a single instruction function,
5229 or stepped back out of a signal handler to the first instruction
5230 of the function. Just keep going, which will single-step back
5232 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
5234 struct symtab_and_line sr_sal;
5236 /* Normal function call return (static or dynamic). */
5238 sr_sal.pc = ecs->stop_func_start;
5239 sr_sal.pspace = get_frame_program_space (frame);
5240 insert_step_resume_breakpoint_at_sal (gdbarch,
5241 sr_sal, null_frame_id);
5245 insert_step_resume_breakpoint_at_caller (frame);
5251 /* If we are in a function call trampoline (a stub between the
5252 calling routine and the real function), locate the real
5253 function. That's what tells us (a) whether we want to step
5254 into it at all, and (b) what prologue we want to run to the
5255 end of, if we do step into it. */
5256 real_stop_pc = skip_language_trampoline (frame, stop_pc);
5257 if (real_stop_pc == 0)
5258 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
5259 if (real_stop_pc != 0)
5260 ecs->stop_func_start = real_stop_pc;
5262 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
5264 struct symtab_and_line sr_sal;
5267 sr_sal.pc = ecs->stop_func_start;
5268 sr_sal.pspace = get_frame_program_space (frame);
5270 insert_step_resume_breakpoint_at_sal (gdbarch,
5271 sr_sal, null_frame_id);
5276 /* If we have line number information for the function we are
5277 thinking of stepping into and the function isn't on the skip
5280 If there are several symtabs at that PC (e.g. with include
5281 files), just want to know whether *any* of them have line
5282 numbers. find_pc_line handles this. */
5284 struct symtab_and_line tmp_sal;
5286 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
5287 if (tmp_sal.line != 0
5288 && !function_name_is_marked_for_skip (ecs->stop_func_name,
5291 if (execution_direction == EXEC_REVERSE)
5292 handle_step_into_function_backward (gdbarch, ecs);
5294 handle_step_into_function (gdbarch, ecs);
5299 /* If we have no line number and the step-stop-if-no-debug is
5300 set, we stop the step so that the user has a chance to switch
5301 in assembly mode. */
5302 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5303 && step_stop_if_no_debug)
5305 end_stepping_range (ecs);
5309 if (execution_direction == EXEC_REVERSE)
5311 /* If we're already at the start of the function, we've either just
5312 stepped backward into a single instruction function without line
5313 number info, or stepped back out of a signal handler to the first
5314 instruction of the function without line number info. Just keep
5315 going, which will single-step back to the caller. */
5316 if (ecs->stop_func_start != stop_pc)
5318 /* Set a breakpoint at callee's start address.
5319 From there we can step once and be back in the caller. */
5320 struct symtab_and_line sr_sal;
5323 sr_sal.pc = ecs->stop_func_start;
5324 sr_sal.pspace = get_frame_program_space (frame);
5325 insert_step_resume_breakpoint_at_sal (gdbarch,
5326 sr_sal, null_frame_id);
5330 /* Set a breakpoint at callee's return address (the address
5331 at which the caller will resume). */
5332 insert_step_resume_breakpoint_at_caller (frame);
5338 /* Reverse stepping through solib trampolines. */
5340 if (execution_direction == EXEC_REVERSE
5341 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5343 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5344 || (ecs->stop_func_start == 0
5345 && in_solib_dynsym_resolve_code (stop_pc)))
5347 /* Any solib trampoline code can be handled in reverse
5348 by simply continuing to single-step. We have already
5349 executed the solib function (backwards), and a few
5350 steps will take us back through the trampoline to the
5355 else if (in_solib_dynsym_resolve_code (stop_pc))
5357 /* Stepped backward into the solib dynsym resolver.
5358 Set a breakpoint at its start and continue, then
5359 one more step will take us out. */
5360 struct symtab_and_line sr_sal;
5363 sr_sal.pc = ecs->stop_func_start;
5364 sr_sal.pspace = get_frame_program_space (frame);
5365 insert_step_resume_breakpoint_at_sal (gdbarch,
5366 sr_sal, null_frame_id);
5372 stop_pc_sal = find_pc_line (stop_pc, 0);
5374 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5375 the trampoline processing logic, however, there are some trampolines
5376 that have no names, so we should do trampoline handling first. */
5377 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5378 && ecs->stop_func_name == NULL
5379 && stop_pc_sal.line == 0)
5382 fprintf_unfiltered (gdb_stdlog,
5383 "infrun: stepped into undebuggable function\n");
5385 /* The inferior just stepped into, or returned to, an
5386 undebuggable function (where there is no debugging information
5387 and no line number corresponding to the address where the
5388 inferior stopped). Since we want to skip this kind of code,
5389 we keep going until the inferior returns from this
5390 function - unless the user has asked us not to (via
5391 set step-mode) or we no longer know how to get back
5392 to the call site. */
5393 if (step_stop_if_no_debug
5394 || !frame_id_p (frame_unwind_caller_id (frame)))
5396 /* If we have no line number and the step-stop-if-no-debug
5397 is set, we stop the step so that the user has a chance to
5398 switch in assembly mode. */
5399 end_stepping_range (ecs);
5404 /* Set a breakpoint at callee's return address (the address
5405 at which the caller will resume). */
5406 insert_step_resume_breakpoint_at_caller (frame);
5412 if (ecs->event_thread->control.step_range_end == 1)
5414 /* It is stepi or nexti. We always want to stop stepping after
5417 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5418 end_stepping_range (ecs);
5422 if (stop_pc_sal.line == 0)
5424 /* We have no line number information. That means to stop
5425 stepping (does this always happen right after one instruction,
5426 when we do "s" in a function with no line numbers,
5427 or can this happen as a result of a return or longjmp?). */
5429 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5430 end_stepping_range (ecs);
5434 /* Look for "calls" to inlined functions, part one. If the inline
5435 frame machinery detected some skipped call sites, we have entered
5436 a new inline function. */
5438 if (frame_id_eq (get_frame_id (get_current_frame ()),
5439 ecs->event_thread->control.step_frame_id)
5440 && inline_skipped_frames (ecs->ptid))
5442 struct symtab_and_line call_sal;
5445 fprintf_unfiltered (gdb_stdlog,
5446 "infrun: stepped into inlined function\n");
5448 find_frame_sal (get_current_frame (), &call_sal);
5450 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5452 /* For "step", we're going to stop. But if the call site
5453 for this inlined function is on the same source line as
5454 we were previously stepping, go down into the function
5455 first. Otherwise stop at the call site. */
5457 if (call_sal.line == ecs->event_thread->current_line
5458 && call_sal.symtab == ecs->event_thread->current_symtab)
5459 step_into_inline_frame (ecs->ptid);
5461 end_stepping_range (ecs);
5466 /* For "next", we should stop at the call site if it is on a
5467 different source line. Otherwise continue through the
5468 inlined function. */
5469 if (call_sal.line == ecs->event_thread->current_line
5470 && call_sal.symtab == ecs->event_thread->current_symtab)
5473 end_stepping_range (ecs);
5478 /* Look for "calls" to inlined functions, part two. If we are still
5479 in the same real function we were stepping through, but we have
5480 to go further up to find the exact frame ID, we are stepping
5481 through a more inlined call beyond its call site. */
5483 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5484 && !frame_id_eq (get_frame_id (get_current_frame ()),
5485 ecs->event_thread->control.step_frame_id)
5486 && stepped_in_from (get_current_frame (),
5487 ecs->event_thread->control.step_frame_id))
5490 fprintf_unfiltered (gdb_stdlog,
5491 "infrun: stepping through inlined function\n");
5493 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5496 end_stepping_range (ecs);
5500 if ((stop_pc == stop_pc_sal.pc)
5501 && (ecs->event_thread->current_line != stop_pc_sal.line
5502 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5504 /* We are at the start of a different line. So stop. Note that
5505 we don't stop if we step into the middle of a different line.
5506 That is said to make things like for (;;) statements work
5509 fprintf_unfiltered (gdb_stdlog,
5510 "infrun: stepped to a different line\n");
5511 end_stepping_range (ecs);
5515 /* We aren't done stepping.
5517 Optimize by setting the stepping range to the line.
5518 (We might not be in the original line, but if we entered a
5519 new line in mid-statement, we continue stepping. This makes
5520 things like for(;;) statements work better.) */
5522 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5523 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5524 ecs->event_thread->control.may_range_step = 1;
5525 set_step_info (frame, stop_pc_sal);
5528 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5532 /* In all-stop mode, if we're currently stepping but have stopped in
5533 some other thread, we may need to switch back to the stepped
5534 thread. Returns true we set the inferior running, false if we left
5535 it stopped (and the event needs further processing). */
5538 switch_back_to_stepped_thread (struct execution_control_state *ecs)
5542 struct thread_info *tp;
5543 struct thread_info *stepping_thread;
5544 struct thread_info *step_over;
5546 /* If any thread is blocked on some internal breakpoint, and we
5547 simply need to step over that breakpoint to get it going
5548 again, do that first. */
5550 /* However, if we see an event for the stepping thread, then we
5551 know all other threads have been moved past their breakpoints
5552 already. Let the caller check whether the step is finished,
5553 etc., before deciding to move it past a breakpoint. */
5554 if (ecs->event_thread->control.step_range_end != 0)
5557 /* Check if the current thread is blocked on an incomplete
5558 step-over, interrupted by a random signal. */
5559 if (ecs->event_thread->control.trap_expected
5560 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5564 fprintf_unfiltered (gdb_stdlog,
5565 "infrun: need to finish step-over of [%s]\n",
5566 target_pid_to_str (ecs->event_thread->ptid));
5572 /* Check if the current thread is blocked by a single-step
5573 breakpoint of another thread. */
5574 if (ecs->hit_singlestep_breakpoint)
5578 fprintf_unfiltered (gdb_stdlog,
5579 "infrun: need to step [%s] over single-step "
5581 target_pid_to_str (ecs->ptid));
5587 /* Otherwise, we no longer expect a trap in the current thread.
5588 Clear the trap_expected flag before switching back -- this is
5589 what keep_going does as well, if we call it. */
5590 ecs->event_thread->control.trap_expected = 0;
5592 /* Likewise, clear the signal if it should not be passed. */
5593 if (!signal_program[ecs->event_thread->suspend.stop_signal])
5594 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5596 /* If scheduler locking applies even if not stepping, there's no
5597 need to walk over threads. Above we've checked whether the
5598 current thread is stepping. If some other thread not the
5599 event thread is stepping, then it must be that scheduler
5600 locking is not in effect. */
5601 if (schedlock_applies (ecs->event_thread))
5604 /* Look for the stepping/nexting thread, and check if any other
5605 thread other than the stepping thread needs to start a
5606 step-over. Do all step-overs before actually proceeding with
5608 stepping_thread = NULL;
5610 ALL_NON_EXITED_THREADS (tp)
5612 /* Ignore threads of processes we're not resuming. */
5614 && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
5617 /* When stepping over a breakpoint, we lock all threads
5618 except the one that needs to move past the breakpoint.
5619 If a non-event thread has this set, the "incomplete
5620 step-over" check above should have caught it earlier. */
5621 gdb_assert (!tp->control.trap_expected);
5623 /* Did we find the stepping thread? */
5624 if (tp->control.step_range_end)
5626 /* Yep. There should only one though. */
5627 gdb_assert (stepping_thread == NULL);
5629 /* The event thread is handled at the top, before we
5631 gdb_assert (tp != ecs->event_thread);
5633 /* If some thread other than the event thread is
5634 stepping, then scheduler locking can't be in effect,
5635 otherwise we wouldn't have resumed the current event
5636 thread in the first place. */
5637 gdb_assert (!schedlock_applies (tp));
5639 stepping_thread = tp;
5641 else if (thread_still_needs_step_over (tp))
5645 /* At the top we've returned early if the event thread
5646 is stepping. If some other thread not the event
5647 thread is stepping, then scheduler locking can't be
5648 in effect, and we can resume this thread. No need to
5649 keep looking for the stepping thread then. */
5654 if (step_over != NULL)
5659 fprintf_unfiltered (gdb_stdlog,
5660 "infrun: need to step-over [%s]\n",
5661 target_pid_to_str (tp->ptid));
5664 /* Only the stepping thread should have this set. */
5665 gdb_assert (tp->control.step_range_end == 0);
5667 ecs->ptid = tp->ptid;
5668 ecs->event_thread = tp;
5669 switch_to_thread (ecs->ptid);
5674 if (stepping_thread != NULL)
5676 struct frame_info *frame;
5677 struct gdbarch *gdbarch;
5679 tp = stepping_thread;
5681 /* If the stepping thread exited, then don't try to switch
5682 back and resume it, which could fail in several different
5683 ways depending on the target. Instead, just keep going.
5685 We can find a stepping dead thread in the thread list in
5688 - The target supports thread exit events, and when the
5689 target tries to delete the thread from the thread list,
5690 inferior_ptid pointed at the exiting thread. In such
5691 case, calling delete_thread does not really remove the
5692 thread from the list; instead, the thread is left listed,
5693 with 'exited' state.
5695 - The target's debug interface does not support thread
5696 exit events, and so we have no idea whatsoever if the
5697 previously stepping thread is still alive. For that
5698 reason, we need to synchronously query the target
5700 if (is_exited (tp->ptid)
5701 || !target_thread_alive (tp->ptid))
5704 fprintf_unfiltered (gdb_stdlog,
5705 "infrun: not switching back to "
5706 "stepped thread, it has vanished\n");
5708 delete_thread (tp->ptid);
5714 fprintf_unfiltered (gdb_stdlog,
5715 "infrun: switching back to stepped thread\n");
5717 ecs->event_thread = tp;
5718 ecs->ptid = tp->ptid;
5719 context_switch (ecs->ptid);
5721 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5722 frame = get_current_frame ();
5723 gdbarch = get_frame_arch (frame);
5725 /* If the PC of the thread we were trying to single-step has
5726 changed, then that thread has trapped or been signaled,
5727 but the event has not been reported to GDB yet. Re-poll
5728 the target looking for this particular thread's event
5729 (i.e. temporarily enable schedlock) by:
5731 - setting a break at the current PC
5732 - resuming that particular thread, only (by setting
5735 This prevents us continuously moving the single-step
5736 breakpoint forward, one instruction at a time,
5739 if (stop_pc != tp->prev_pc)
5744 fprintf_unfiltered (gdb_stdlog,
5745 "infrun: expected thread advanced also\n");
5747 /* Clear the info of the previous step-over, as it's no
5748 longer valid. It's what keep_going would do too, if
5749 we called it. Must do this before trying to insert
5750 the sss breakpoint, otherwise if we were previously
5751 trying to step over this exact address in another
5752 thread, the breakpoint ends up not installed. */
5753 clear_step_over_info ();
5755 insert_single_step_breakpoint (get_frame_arch (frame),
5756 get_frame_address_space (frame),
5759 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
5760 do_target_resume (resume_ptid,
5761 currently_stepping (tp), GDB_SIGNAL_0);
5762 prepare_to_wait (ecs);
5767 fprintf_unfiltered (gdb_stdlog,
5768 "infrun: expected thread still "
5769 "hasn't advanced\n");
5779 /* Is thread TP in the middle of single-stepping? */
5782 currently_stepping (struct thread_info *tp)
5784 return ((tp->control.step_range_end
5785 && tp->control.step_resume_breakpoint == NULL)
5786 || tp->control.trap_expected
5787 || tp->stepped_breakpoint
5788 || bpstat_should_step ());
5791 /* Inferior has stepped into a subroutine call with source code that
5792 we should not step over. Do step to the first line of code in
5796 handle_step_into_function (struct gdbarch *gdbarch,
5797 struct execution_control_state *ecs)
5799 struct compunit_symtab *cust;
5800 struct symtab_and_line stop_func_sal, sr_sal;
5802 fill_in_stop_func (gdbarch, ecs);
5804 cust = find_pc_compunit_symtab (stop_pc);
5805 if (cust != NULL && compunit_language (cust) != language_asm)
5806 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5807 ecs->stop_func_start);
5809 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5810 /* Use the step_resume_break to step until the end of the prologue,
5811 even if that involves jumps (as it seems to on the vax under
5813 /* If the prologue ends in the middle of a source line, continue to
5814 the end of that source line (if it is still within the function).
5815 Otherwise, just go to end of prologue. */
5816 if (stop_func_sal.end
5817 && stop_func_sal.pc != ecs->stop_func_start
5818 && stop_func_sal.end < ecs->stop_func_end)
5819 ecs->stop_func_start = stop_func_sal.end;
5821 /* Architectures which require breakpoint adjustment might not be able
5822 to place a breakpoint at the computed address. If so, the test
5823 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5824 ecs->stop_func_start to an address at which a breakpoint may be
5825 legitimately placed.
5827 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5828 made, GDB will enter an infinite loop when stepping through
5829 optimized code consisting of VLIW instructions which contain
5830 subinstructions corresponding to different source lines. On
5831 FR-V, it's not permitted to place a breakpoint on any but the
5832 first subinstruction of a VLIW instruction. When a breakpoint is
5833 set, GDB will adjust the breakpoint address to the beginning of
5834 the VLIW instruction. Thus, we need to make the corresponding
5835 adjustment here when computing the stop address. */
5837 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5839 ecs->stop_func_start
5840 = gdbarch_adjust_breakpoint_address (gdbarch,
5841 ecs->stop_func_start);
5844 if (ecs->stop_func_start == stop_pc)
5846 /* We are already there: stop now. */
5847 end_stepping_range (ecs);
5852 /* Put the step-breakpoint there and go until there. */
5853 init_sal (&sr_sal); /* initialize to zeroes */
5854 sr_sal.pc = ecs->stop_func_start;
5855 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5856 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5858 /* Do not specify what the fp should be when we stop since on
5859 some machines the prologue is where the new fp value is
5861 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5863 /* And make sure stepping stops right away then. */
5864 ecs->event_thread->control.step_range_end
5865 = ecs->event_thread->control.step_range_start;
5870 /* Inferior has stepped backward into a subroutine call with source
5871 code that we should not step over. Do step to the beginning of the
5872 last line of code in it. */
5875 handle_step_into_function_backward (struct gdbarch *gdbarch,
5876 struct execution_control_state *ecs)
5878 struct compunit_symtab *cust;
5879 struct symtab_and_line stop_func_sal;
5881 fill_in_stop_func (gdbarch, ecs);
5883 cust = find_pc_compunit_symtab (stop_pc);
5884 if (cust != NULL && compunit_language (cust) != language_asm)
5885 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5886 ecs->stop_func_start);
5888 stop_func_sal = find_pc_line (stop_pc, 0);
5890 /* OK, we're just going to keep stepping here. */
5891 if (stop_func_sal.pc == stop_pc)
5893 /* We're there already. Just stop stepping now. */
5894 end_stepping_range (ecs);
5898 /* Else just reset the step range and keep going.
5899 No step-resume breakpoint, they don't work for
5900 epilogues, which can have multiple entry paths. */
5901 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5902 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5908 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5909 This is used to both functions and to skip over code. */
5912 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5913 struct symtab_and_line sr_sal,
5914 struct frame_id sr_id,
5915 enum bptype sr_type)
5917 /* There should never be more than one step-resume or longjmp-resume
5918 breakpoint per thread, so we should never be setting a new
5919 step_resume_breakpoint when one is already active. */
5920 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5921 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5924 fprintf_unfiltered (gdb_stdlog,
5925 "infrun: inserting step-resume breakpoint at %s\n",
5926 paddress (gdbarch, sr_sal.pc));
5928 inferior_thread ()->control.step_resume_breakpoint
5929 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5933 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5934 struct symtab_and_line sr_sal,
5935 struct frame_id sr_id)
5937 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5942 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5943 This is used to skip a potential signal handler.
5945 This is called with the interrupted function's frame. The signal
5946 handler, when it returns, will resume the interrupted function at
5950 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5952 struct symtab_and_line sr_sal;
5953 struct gdbarch *gdbarch;
5955 gdb_assert (return_frame != NULL);
5956 init_sal (&sr_sal); /* initialize to zeros */
5958 gdbarch = get_frame_arch (return_frame);
5959 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5960 sr_sal.section = find_pc_overlay (sr_sal.pc);
5961 sr_sal.pspace = get_frame_program_space (return_frame);
5963 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5964 get_stack_frame_id (return_frame),
5968 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5969 is used to skip a function after stepping into it (for "next" or if
5970 the called function has no debugging information).
5972 The current function has almost always been reached by single
5973 stepping a call or return instruction. NEXT_FRAME belongs to the
5974 current function, and the breakpoint will be set at the caller's
5977 This is a separate function rather than reusing
5978 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5979 get_prev_frame, which may stop prematurely (see the implementation
5980 of frame_unwind_caller_id for an example). */
5983 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5985 struct symtab_and_line sr_sal;
5986 struct gdbarch *gdbarch;
5988 /* We shouldn't have gotten here if we don't know where the call site
5990 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5992 init_sal (&sr_sal); /* initialize to zeros */
5994 gdbarch = frame_unwind_caller_arch (next_frame);
5995 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5996 frame_unwind_caller_pc (next_frame));
5997 sr_sal.section = find_pc_overlay (sr_sal.pc);
5998 sr_sal.pspace = frame_unwind_program_space (next_frame);
6000 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
6001 frame_unwind_caller_id (next_frame));
6004 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
6005 new breakpoint at the target of a jmp_buf. The handling of
6006 longjmp-resume uses the same mechanisms used for handling
6007 "step-resume" breakpoints. */
6010 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
6012 /* There should never be more than one longjmp-resume breakpoint per
6013 thread, so we should never be setting a new
6014 longjmp_resume_breakpoint when one is already active. */
6015 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
6018 fprintf_unfiltered (gdb_stdlog,
6019 "infrun: inserting longjmp-resume breakpoint at %s\n",
6020 paddress (gdbarch, pc));
6022 inferior_thread ()->control.exception_resume_breakpoint =
6023 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
6026 /* Insert an exception resume breakpoint. TP is the thread throwing
6027 the exception. The block B is the block of the unwinder debug hook
6028 function. FRAME is the frame corresponding to the call to this
6029 function. SYM is the symbol of the function argument holding the
6030 target PC of the exception. */
6033 insert_exception_resume_breakpoint (struct thread_info *tp,
6034 const struct block *b,
6035 struct frame_info *frame,
6040 struct symbol *vsym;
6041 struct value *value;
6043 struct breakpoint *bp;
6045 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
6046 value = read_var_value (vsym, frame);
6047 /* If the value was optimized out, revert to the old behavior. */
6048 if (! value_optimized_out (value))
6050 handler = value_as_address (value);
6053 fprintf_unfiltered (gdb_stdlog,
6054 "infrun: exception resume at %lx\n",
6055 (unsigned long) handler);
6057 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
6058 handler, bp_exception_resume);
6060 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
6063 bp->thread = tp->num;
6064 inferior_thread ()->control.exception_resume_breakpoint = bp;
6067 CATCH (e, RETURN_MASK_ERROR)
6069 /* We want to ignore errors here. */
6074 /* A helper for check_exception_resume that sets an
6075 exception-breakpoint based on a SystemTap probe. */
6078 insert_exception_resume_from_probe (struct thread_info *tp,
6079 const struct bound_probe *probe,
6080 struct frame_info *frame)
6082 struct value *arg_value;
6084 struct breakpoint *bp;
6086 arg_value = probe_safe_evaluate_at_pc (frame, 1);
6090 handler = value_as_address (arg_value);
6093 fprintf_unfiltered (gdb_stdlog,
6094 "infrun: exception resume at %s\n",
6095 paddress (get_objfile_arch (probe->objfile),
6098 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
6099 handler, bp_exception_resume);
6100 bp->thread = tp->num;
6101 inferior_thread ()->control.exception_resume_breakpoint = bp;
6104 /* This is called when an exception has been intercepted. Check to
6105 see whether the exception's destination is of interest, and if so,
6106 set an exception resume breakpoint there. */
6109 check_exception_resume (struct execution_control_state *ecs,
6110 struct frame_info *frame)
6112 struct bound_probe probe;
6113 struct symbol *func;
6115 /* First see if this exception unwinding breakpoint was set via a
6116 SystemTap probe point. If so, the probe has two arguments: the
6117 CFA and the HANDLER. We ignore the CFA, extract the handler, and
6118 set a breakpoint there. */
6119 probe = find_probe_by_pc (get_frame_pc (frame));
6122 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
6126 func = get_frame_function (frame);
6132 const struct block *b;
6133 struct block_iterator iter;
6137 /* The exception breakpoint is a thread-specific breakpoint on
6138 the unwinder's debug hook, declared as:
6140 void _Unwind_DebugHook (void *cfa, void *handler);
6142 The CFA argument indicates the frame to which control is
6143 about to be transferred. HANDLER is the destination PC.
6145 We ignore the CFA and set a temporary breakpoint at HANDLER.
6146 This is not extremely efficient but it avoids issues in gdb
6147 with computing the DWARF CFA, and it also works even in weird
6148 cases such as throwing an exception from inside a signal
6151 b = SYMBOL_BLOCK_VALUE (func);
6152 ALL_BLOCK_SYMBOLS (b, iter, sym)
6154 if (!SYMBOL_IS_ARGUMENT (sym))
6161 insert_exception_resume_breakpoint (ecs->event_thread,
6167 CATCH (e, RETURN_MASK_ERROR)
6174 stop_waiting (struct execution_control_state *ecs)
6177 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
6179 clear_step_over_info ();
6181 /* Let callers know we don't want to wait for the inferior anymore. */
6182 ecs->wait_some_more = 0;
6185 /* Called when we should continue running the inferior, because the
6186 current event doesn't cause a user visible stop. This does the
6187 resuming part; waiting for the next event is done elsewhere. */
6190 keep_going (struct execution_control_state *ecs)
6192 /* Make sure normal_stop is called if we get a QUIT handled before
6194 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
6196 /* Save the pc before execution, to compare with pc after stop. */
6197 ecs->event_thread->prev_pc
6198 = regcache_read_pc (get_thread_regcache (ecs->ptid));
6200 if (ecs->event_thread->control.trap_expected
6201 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6203 /* We haven't yet gotten our trap, and either: intercepted a
6204 non-signal event (e.g., a fork); or took a signal which we
6205 are supposed to pass through to the inferior. Simply
6207 discard_cleanups (old_cleanups);
6208 resume (ecs->event_thread->suspend.stop_signal);
6212 struct regcache *regcache = get_current_regcache ();
6216 /* Either the trap was not expected, but we are continuing
6217 anyway (if we got a signal, the user asked it be passed to
6220 We got our expected trap, but decided we should resume from
6223 We're going to run this baby now!
6225 Note that insert_breakpoints won't try to re-insert
6226 already inserted breakpoints. Therefore, we don't
6227 care if breakpoints were already inserted, or not. */
6229 /* If we need to step over a breakpoint, and we're not using
6230 displaced stepping to do so, insert all breakpoints
6231 (watchpoints, etc.) but the one we're stepping over, step one
6232 instruction, and then re-insert the breakpoint when that step
6235 remove_bp = (ecs->hit_singlestep_breakpoint
6236 || thread_still_needs_step_over (ecs->event_thread));
6237 remove_wps = (ecs->event_thread->stepping_over_watchpoint
6238 && !target_have_steppable_watchpoint);
6240 if (remove_bp && !use_displaced_stepping (get_regcache_arch (regcache)))
6242 set_step_over_info (get_regcache_aspace (regcache),
6243 regcache_read_pc (regcache), remove_wps);
6245 else if (remove_wps)
6246 set_step_over_info (NULL, 0, remove_wps);
6248 clear_step_over_info ();
6250 /* Stop stepping if inserting breakpoints fails. */
6253 insert_breakpoints ();
6255 CATCH (e, RETURN_MASK_ERROR)
6257 exception_print (gdb_stderr, e);
6263 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
6265 /* Do not deliver GDB_SIGNAL_TRAP (except when the user
6266 explicitly specifies that such a signal should be delivered
6267 to the target program). Typically, that would occur when a
6268 user is debugging a target monitor on a simulator: the target
6269 monitor sets a breakpoint; the simulator encounters this
6270 breakpoint and halts the simulation handing control to GDB;
6271 GDB, noting that the stop address doesn't map to any known
6272 breakpoint, returns control back to the simulator; the
6273 simulator then delivers the hardware equivalent of a
6274 GDB_SIGNAL_TRAP to the program being debugged. */
6275 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6276 && !signal_program[ecs->event_thread->suspend.stop_signal])
6277 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6279 discard_cleanups (old_cleanups);
6280 resume (ecs->event_thread->suspend.stop_signal);
6283 prepare_to_wait (ecs);
6286 /* This function normally comes after a resume, before
6287 handle_inferior_event exits. It takes care of any last bits of
6288 housekeeping, and sets the all-important wait_some_more flag. */
6291 prepare_to_wait (struct execution_control_state *ecs)
6294 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
6296 /* This is the old end of the while loop. Let everybody know we
6297 want to wait for the inferior some more and get called again
6299 ecs->wait_some_more = 1;
6302 /* We are done with the step range of a step/next/si/ni command.
6303 Called once for each n of a "step n" operation. */
6306 end_stepping_range (struct execution_control_state *ecs)
6308 ecs->event_thread->control.stop_step = 1;
6312 /* Several print_*_reason functions to print why the inferior has stopped.
6313 We always print something when the inferior exits, or receives a signal.
6314 The rest of the cases are dealt with later on in normal_stop and
6315 print_it_typical. Ideally there should be a call to one of these
6316 print_*_reason functions functions from handle_inferior_event each time
6317 stop_waiting is called.
6319 Note that we don't call these directly, instead we delegate that to
6320 the interpreters, through observers. Interpreters then call these
6321 with whatever uiout is right. */
6324 print_end_stepping_range_reason (struct ui_out *uiout)
6326 /* For CLI-like interpreters, print nothing. */
6328 if (ui_out_is_mi_like_p (uiout))
6330 ui_out_field_string (uiout, "reason",
6331 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
6336 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
6338 annotate_signalled ();
6339 if (ui_out_is_mi_like_p (uiout))
6341 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
6342 ui_out_text (uiout, "\nProgram terminated with signal ");
6343 annotate_signal_name ();
6344 ui_out_field_string (uiout, "signal-name",
6345 gdb_signal_to_name (siggnal));
6346 annotate_signal_name_end ();
6347 ui_out_text (uiout, ", ");
6348 annotate_signal_string ();
6349 ui_out_field_string (uiout, "signal-meaning",
6350 gdb_signal_to_string (siggnal));
6351 annotate_signal_string_end ();
6352 ui_out_text (uiout, ".\n");
6353 ui_out_text (uiout, "The program no longer exists.\n");
6357 print_exited_reason (struct ui_out *uiout, int exitstatus)
6359 struct inferior *inf = current_inferior ();
6360 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
6362 annotate_exited (exitstatus);
6365 if (ui_out_is_mi_like_p (uiout))
6366 ui_out_field_string (uiout, "reason",
6367 async_reason_lookup (EXEC_ASYNC_EXITED));
6368 ui_out_text (uiout, "[Inferior ");
6369 ui_out_text (uiout, plongest (inf->num));
6370 ui_out_text (uiout, " (");
6371 ui_out_text (uiout, pidstr);
6372 ui_out_text (uiout, ") exited with code ");
6373 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
6374 ui_out_text (uiout, "]\n");
6378 if (ui_out_is_mi_like_p (uiout))
6380 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
6381 ui_out_text (uiout, "[Inferior ");
6382 ui_out_text (uiout, plongest (inf->num));
6383 ui_out_text (uiout, " (");
6384 ui_out_text (uiout, pidstr);
6385 ui_out_text (uiout, ") exited normally]\n");
6390 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
6394 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
6396 struct thread_info *t = inferior_thread ();
6398 ui_out_text (uiout, "\n[");
6399 ui_out_field_string (uiout, "thread-name",
6400 target_pid_to_str (t->ptid));
6401 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
6402 ui_out_text (uiout, " stopped");
6406 ui_out_text (uiout, "\nProgram received signal ");
6407 annotate_signal_name ();
6408 if (ui_out_is_mi_like_p (uiout))
6410 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
6411 ui_out_field_string (uiout, "signal-name",
6412 gdb_signal_to_name (siggnal));
6413 annotate_signal_name_end ();
6414 ui_out_text (uiout, ", ");
6415 annotate_signal_string ();
6416 ui_out_field_string (uiout, "signal-meaning",
6417 gdb_signal_to_string (siggnal));
6418 annotate_signal_string_end ();
6420 ui_out_text (uiout, ".\n");
6424 print_no_history_reason (struct ui_out *uiout)
6426 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
6429 /* Print current location without a level number, if we have changed
6430 functions or hit a breakpoint. Print source line if we have one.
6431 bpstat_print contains the logic deciding in detail what to print,
6432 based on the event(s) that just occurred. */
6435 print_stop_event (struct target_waitstatus *ws)
6439 int do_frame_printing = 1;
6440 struct thread_info *tp = inferior_thread ();
6442 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
6446 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
6447 should) carry around the function and does (or should) use
6448 that when doing a frame comparison. */
6449 if (tp->control.stop_step
6450 && frame_id_eq (tp->control.step_frame_id,
6451 get_frame_id (get_current_frame ()))
6452 && tp->control.step_start_function == find_pc_function (stop_pc))
6454 /* Finished step, just print source line. */
6455 source_flag = SRC_LINE;
6459 /* Print location and source line. */
6460 source_flag = SRC_AND_LOC;
6463 case PRINT_SRC_AND_LOC:
6464 /* Print location and source line. */
6465 source_flag = SRC_AND_LOC;
6467 case PRINT_SRC_ONLY:
6468 source_flag = SRC_LINE;
6471 /* Something bogus. */
6472 source_flag = SRC_LINE;
6473 do_frame_printing = 0;
6476 internal_error (__FILE__, __LINE__, _("Unknown value."));
6479 /* The behavior of this routine with respect to the source
6481 SRC_LINE: Print only source line
6482 LOCATION: Print only location
6483 SRC_AND_LOC: Print location and source line. */
6484 if (do_frame_printing)
6485 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
6487 /* Display the auto-display expressions. */
6491 /* Here to return control to GDB when the inferior stops for real.
6492 Print appropriate messages, remove breakpoints, give terminal our modes.
6494 STOP_PRINT_FRAME nonzero means print the executing frame
6495 (pc, function, args, file, line number and line text).
6496 BREAKPOINTS_FAILED nonzero means stop was due to error
6497 attempting to insert breakpoints. */
6502 struct target_waitstatus last;
6504 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
6506 get_last_target_status (&last_ptid, &last);
6508 /* If an exception is thrown from this point on, make sure to
6509 propagate GDB's knowledge of the executing state to the
6510 frontend/user running state. A QUIT is an easy exception to see
6511 here, so do this before any filtered output. */
6513 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
6514 else if (last.kind != TARGET_WAITKIND_SIGNALLED
6515 && last.kind != TARGET_WAITKIND_EXITED
6516 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6517 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
6519 /* As we're presenting a stop, and potentially removing breakpoints,
6520 update the thread list so we can tell whether there are threads
6521 running on the target. With target remote, for example, we can
6522 only learn about new threads when we explicitly update the thread
6523 list. Do this before notifying the interpreters about signal
6524 stops, end of stepping ranges, etc., so that the "new thread"
6525 output is emitted before e.g., "Program received signal FOO",
6526 instead of after. */
6527 update_thread_list ();
6529 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
6530 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
6532 /* As with the notification of thread events, we want to delay
6533 notifying the user that we've switched thread context until
6534 the inferior actually stops.
6536 There's no point in saying anything if the inferior has exited.
6537 Note that SIGNALLED here means "exited with a signal", not
6538 "received a signal".
6540 Also skip saying anything in non-stop mode. In that mode, as we
6541 don't want GDB to switch threads behind the user's back, to avoid
6542 races where the user is typing a command to apply to thread x,
6543 but GDB switches to thread y before the user finishes entering
6544 the command, fetch_inferior_event installs a cleanup to restore
6545 the current thread back to the thread the user had selected right
6546 after this event is handled, so we're not really switching, only
6547 informing of a stop. */
6549 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
6550 && target_has_execution
6551 && last.kind != TARGET_WAITKIND_SIGNALLED
6552 && last.kind != TARGET_WAITKIND_EXITED
6553 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6555 target_terminal_ours_for_output ();
6556 printf_filtered (_("[Switching to %s]\n"),
6557 target_pid_to_str (inferior_ptid));
6558 annotate_thread_changed ();
6559 previous_inferior_ptid = inferior_ptid;
6562 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
6564 gdb_assert (sync_execution || !target_can_async_p ());
6566 target_terminal_ours_for_output ();
6567 printf_filtered (_("No unwaited-for children left.\n"));
6570 /* Note: this depends on the update_thread_list call above. */
6571 if (!breakpoints_should_be_inserted_now () && target_has_execution)
6573 if (remove_breakpoints ())
6575 target_terminal_ours_for_output ();
6576 printf_filtered (_("Cannot remove breakpoints because "
6577 "program is no longer writable.\nFurther "
6578 "execution is probably impossible.\n"));
6582 /* If an auto-display called a function and that got a signal,
6583 delete that auto-display to avoid an infinite recursion. */
6585 if (stopped_by_random_signal)
6586 disable_current_display ();
6588 /* Notify observers if we finished a "step"-like command, etc. */
6589 if (target_has_execution
6590 && last.kind != TARGET_WAITKIND_SIGNALLED
6591 && last.kind != TARGET_WAITKIND_EXITED
6592 && inferior_thread ()->control.stop_step)
6594 /* But not if in the middle of doing a "step n" operation for
6596 if (inferior_thread ()->step_multi)
6599 observer_notify_end_stepping_range ();
6602 target_terminal_ours ();
6603 async_enable_stdin ();
6605 /* Set the current source location. This will also happen if we
6606 display the frame below, but the current SAL will be incorrect
6607 during a user hook-stop function. */
6608 if (has_stack_frames () && !stop_stack_dummy)
6609 set_current_sal_from_frame (get_current_frame ());
6611 /* Let the user/frontend see the threads as stopped, but do nothing
6612 if the thread was running an infcall. We may be e.g., evaluating
6613 a breakpoint condition. In that case, the thread had state
6614 THREAD_RUNNING before the infcall, and shall remain set to
6615 running, all without informing the user/frontend about state
6616 transition changes. If this is actually a call command, then the
6617 thread was originally already stopped, so there's no state to
6619 if (target_has_execution && inferior_thread ()->control.in_infcall)
6620 discard_cleanups (old_chain);
6622 do_cleanups (old_chain);
6624 /* Look up the hook_stop and run it (CLI internally handles problem
6625 of stop_command's pre-hook not existing). */
6627 catch_errors (hook_stop_stub, stop_command,
6628 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6630 if (!has_stack_frames ())
6633 if (last.kind == TARGET_WAITKIND_SIGNALLED
6634 || last.kind == TARGET_WAITKIND_EXITED)
6637 /* Select innermost stack frame - i.e., current frame is frame 0,
6638 and current location is based on that.
6639 Don't do this on return from a stack dummy routine,
6640 or if the program has exited. */
6642 if (!stop_stack_dummy)
6644 select_frame (get_current_frame ());
6646 /* If --batch-silent is enabled then there's no need to print the current
6647 source location, and to try risks causing an error message about
6648 missing source files. */
6649 if (stop_print_frame && !batch_silent)
6650 print_stop_event (&last);
6653 /* Save the function value return registers, if we care.
6654 We might be about to restore their previous contents. */
6655 if (inferior_thread ()->control.proceed_to_finish
6656 && execution_direction != EXEC_REVERSE)
6658 /* This should not be necessary. */
6660 regcache_xfree (stop_registers);
6662 /* NB: The copy goes through to the target picking up the value of
6663 all the registers. */
6664 stop_registers = regcache_dup (get_current_regcache ());
6667 if (stop_stack_dummy == STOP_STACK_DUMMY)
6669 /* Pop the empty frame that contains the stack dummy.
6670 This also restores inferior state prior to the call
6671 (struct infcall_suspend_state). */
6672 struct frame_info *frame = get_current_frame ();
6674 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6676 /* frame_pop() calls reinit_frame_cache as the last thing it
6677 does which means there's currently no selected frame. We
6678 don't need to re-establish a selected frame if the dummy call
6679 returns normally, that will be done by
6680 restore_infcall_control_state. However, we do have to handle
6681 the case where the dummy call is returning after being
6682 stopped (e.g. the dummy call previously hit a breakpoint).
6683 We can't know which case we have so just always re-establish
6684 a selected frame here. */
6685 select_frame (get_current_frame ());
6689 annotate_stopped ();
6691 /* Suppress the stop observer if we're in the middle of:
6693 - a step n (n > 1), as there still more steps to be done.
6695 - a "finish" command, as the observer will be called in
6696 finish_command_continuation, so it can include the inferior
6697 function's return value.
6699 - calling an inferior function, as we pretend we inferior didn't
6700 run at all. The return value of the call is handled by the
6701 expression evaluator, through call_function_by_hand. */
6703 if (!target_has_execution
6704 || last.kind == TARGET_WAITKIND_SIGNALLED
6705 || last.kind == TARGET_WAITKIND_EXITED
6706 || last.kind == TARGET_WAITKIND_NO_RESUMED
6707 || (!(inferior_thread ()->step_multi
6708 && inferior_thread ()->control.stop_step)
6709 && !(inferior_thread ()->control.stop_bpstat
6710 && inferior_thread ()->control.proceed_to_finish)
6711 && !inferior_thread ()->control.in_infcall))
6713 if (!ptid_equal (inferior_ptid, null_ptid))
6714 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6717 observer_notify_normal_stop (NULL, stop_print_frame);
6720 if (target_has_execution)
6722 if (last.kind != TARGET_WAITKIND_SIGNALLED
6723 && last.kind != TARGET_WAITKIND_EXITED)
6724 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6725 Delete any breakpoint that is to be deleted at the next stop. */
6726 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6729 /* Try to get rid of automatically added inferiors that are no
6730 longer needed. Keeping those around slows down things linearly.
6731 Note that this never removes the current inferior. */
6736 hook_stop_stub (void *cmd)
6738 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6743 signal_stop_state (int signo)
6745 return signal_stop[signo];
6749 signal_print_state (int signo)
6751 return signal_print[signo];
6755 signal_pass_state (int signo)
6757 return signal_program[signo];
6761 signal_cache_update (int signo)
6765 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6766 signal_cache_update (signo);
6771 signal_pass[signo] = (signal_stop[signo] == 0
6772 && signal_print[signo] == 0
6773 && signal_program[signo] == 1
6774 && signal_catch[signo] == 0);
6778 signal_stop_update (int signo, int state)
6780 int ret = signal_stop[signo];
6782 signal_stop[signo] = state;
6783 signal_cache_update (signo);
6788 signal_print_update (int signo, int state)
6790 int ret = signal_print[signo];
6792 signal_print[signo] = state;
6793 signal_cache_update (signo);
6798 signal_pass_update (int signo, int state)
6800 int ret = signal_program[signo];
6802 signal_program[signo] = state;
6803 signal_cache_update (signo);
6807 /* Update the global 'signal_catch' from INFO and notify the
6811 signal_catch_update (const unsigned int *info)
6815 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6816 signal_catch[i] = info[i] > 0;
6817 signal_cache_update (-1);
6818 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6822 sig_print_header (void)
6824 printf_filtered (_("Signal Stop\tPrint\tPass "
6825 "to program\tDescription\n"));
6829 sig_print_info (enum gdb_signal oursig)
6831 const char *name = gdb_signal_to_name (oursig);
6832 int name_padding = 13 - strlen (name);
6834 if (name_padding <= 0)
6837 printf_filtered ("%s", name);
6838 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6839 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6840 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6841 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6842 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6845 /* Specify how various signals in the inferior should be handled. */
6848 handle_command (char *args, int from_tty)
6851 int digits, wordlen;
6852 int sigfirst, signum, siglast;
6853 enum gdb_signal oursig;
6856 unsigned char *sigs;
6857 struct cleanup *old_chain;
6861 error_no_arg (_("signal to handle"));
6864 /* Allocate and zero an array of flags for which signals to handle. */
6866 nsigs = (int) GDB_SIGNAL_LAST;
6867 sigs = (unsigned char *) alloca (nsigs);
6868 memset (sigs, 0, nsigs);
6870 /* Break the command line up into args. */
6872 argv = gdb_buildargv (args);
6873 old_chain = make_cleanup_freeargv (argv);
6875 /* Walk through the args, looking for signal oursigs, signal names, and
6876 actions. Signal numbers and signal names may be interspersed with
6877 actions, with the actions being performed for all signals cumulatively
6878 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6880 while (*argv != NULL)
6882 wordlen = strlen (*argv);
6883 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6887 sigfirst = siglast = -1;
6889 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6891 /* Apply action to all signals except those used by the
6892 debugger. Silently skip those. */
6895 siglast = nsigs - 1;
6897 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6899 SET_SIGS (nsigs, sigs, signal_stop);
6900 SET_SIGS (nsigs, sigs, signal_print);
6902 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6904 UNSET_SIGS (nsigs, sigs, signal_program);
6906 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6908 SET_SIGS (nsigs, sigs, signal_print);
6910 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6912 SET_SIGS (nsigs, sigs, signal_program);
6914 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6916 UNSET_SIGS (nsigs, sigs, signal_stop);
6918 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6920 SET_SIGS (nsigs, sigs, signal_program);
6922 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6924 UNSET_SIGS (nsigs, sigs, signal_print);
6925 UNSET_SIGS (nsigs, sigs, signal_stop);
6927 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6929 UNSET_SIGS (nsigs, sigs, signal_program);
6931 else if (digits > 0)
6933 /* It is numeric. The numeric signal refers to our own
6934 internal signal numbering from target.h, not to host/target
6935 signal number. This is a feature; users really should be
6936 using symbolic names anyway, and the common ones like
6937 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6939 sigfirst = siglast = (int)
6940 gdb_signal_from_command (atoi (*argv));
6941 if ((*argv)[digits] == '-')
6944 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6946 if (sigfirst > siglast)
6948 /* Bet he didn't figure we'd think of this case... */
6956 oursig = gdb_signal_from_name (*argv);
6957 if (oursig != GDB_SIGNAL_UNKNOWN)
6959 sigfirst = siglast = (int) oursig;
6963 /* Not a number and not a recognized flag word => complain. */
6964 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6968 /* If any signal numbers or symbol names were found, set flags for
6969 which signals to apply actions to. */
6971 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6973 switch ((enum gdb_signal) signum)
6975 case GDB_SIGNAL_TRAP:
6976 case GDB_SIGNAL_INT:
6977 if (!allsigs && !sigs[signum])
6979 if (query (_("%s is used by the debugger.\n\
6980 Are you sure you want to change it? "),
6981 gdb_signal_to_name ((enum gdb_signal) signum)))
6987 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6988 gdb_flush (gdb_stdout);
6993 case GDB_SIGNAL_DEFAULT:
6994 case GDB_SIGNAL_UNKNOWN:
6995 /* Make sure that "all" doesn't print these. */
7006 for (signum = 0; signum < nsigs; signum++)
7009 signal_cache_update (-1);
7010 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
7011 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
7015 /* Show the results. */
7016 sig_print_header ();
7017 for (; signum < nsigs; signum++)
7019 sig_print_info (signum);
7025 do_cleanups (old_chain);
7028 /* Complete the "handle" command. */
7030 static VEC (char_ptr) *
7031 handle_completer (struct cmd_list_element *ignore,
7032 const char *text, const char *word)
7034 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
7035 static const char * const keywords[] =
7049 vec_signals = signal_completer (ignore, text, word);
7050 vec_keywords = complete_on_enum (keywords, word, word);
7052 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
7053 VEC_free (char_ptr, vec_signals);
7054 VEC_free (char_ptr, vec_keywords);
7059 xdb_handle_command (char *args, int from_tty)
7062 struct cleanup *old_chain;
7065 error_no_arg (_("xdb command"));
7067 /* Break the command line up into args. */
7069 argv = gdb_buildargv (args);
7070 old_chain = make_cleanup_freeargv (argv);
7071 if (argv[1] != (char *) NULL)
7076 bufLen = strlen (argv[0]) + 20;
7077 argBuf = (char *) xmalloc (bufLen);
7081 enum gdb_signal oursig;
7083 oursig = gdb_signal_from_name (argv[0]);
7084 memset (argBuf, 0, bufLen);
7085 if (strcmp (argv[1], "Q") == 0)
7086 sprintf (argBuf, "%s %s", argv[0], "noprint");
7089 if (strcmp (argv[1], "s") == 0)
7091 if (!signal_stop[oursig])
7092 sprintf (argBuf, "%s %s", argv[0], "stop");
7094 sprintf (argBuf, "%s %s", argv[0], "nostop");
7096 else if (strcmp (argv[1], "i") == 0)
7098 if (!signal_program[oursig])
7099 sprintf (argBuf, "%s %s", argv[0], "pass");
7101 sprintf (argBuf, "%s %s", argv[0], "nopass");
7103 else if (strcmp (argv[1], "r") == 0)
7105 if (!signal_print[oursig])
7106 sprintf (argBuf, "%s %s", argv[0], "print");
7108 sprintf (argBuf, "%s %s", argv[0], "noprint");
7114 handle_command (argBuf, from_tty);
7116 printf_filtered (_("Invalid signal handling flag.\n"));
7121 do_cleanups (old_chain);
7125 gdb_signal_from_command (int num)
7127 if (num >= 1 && num <= 15)
7128 return (enum gdb_signal) num;
7129 error (_("Only signals 1-15 are valid as numeric signals.\n\
7130 Use \"info signals\" for a list of symbolic signals."));
7133 /* Print current contents of the tables set by the handle command.
7134 It is possible we should just be printing signals actually used
7135 by the current target (but for things to work right when switching
7136 targets, all signals should be in the signal tables). */
7139 signals_info (char *signum_exp, int from_tty)
7141 enum gdb_signal oursig;
7143 sig_print_header ();
7147 /* First see if this is a symbol name. */
7148 oursig = gdb_signal_from_name (signum_exp);
7149 if (oursig == GDB_SIGNAL_UNKNOWN)
7151 /* No, try numeric. */
7153 gdb_signal_from_command (parse_and_eval_long (signum_exp));
7155 sig_print_info (oursig);
7159 printf_filtered ("\n");
7160 /* These ugly casts brought to you by the native VAX compiler. */
7161 for (oursig = GDB_SIGNAL_FIRST;
7162 (int) oursig < (int) GDB_SIGNAL_LAST;
7163 oursig = (enum gdb_signal) ((int) oursig + 1))
7167 if (oursig != GDB_SIGNAL_UNKNOWN
7168 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
7169 sig_print_info (oursig);
7172 printf_filtered (_("\nUse the \"handle\" command "
7173 "to change these tables.\n"));
7176 /* Check if it makes sense to read $_siginfo from the current thread
7177 at this point. If not, throw an error. */
7180 validate_siginfo_access (void)
7182 /* No current inferior, no siginfo. */
7183 if (ptid_equal (inferior_ptid, null_ptid))
7184 error (_("No thread selected."));
7186 /* Don't try to read from a dead thread. */
7187 if (is_exited (inferior_ptid))
7188 error (_("The current thread has terminated"));
7190 /* ... or from a spinning thread. */
7191 if (is_running (inferior_ptid))
7192 error (_("Selected thread is running."));
7195 /* The $_siginfo convenience variable is a bit special. We don't know
7196 for sure the type of the value until we actually have a chance to
7197 fetch the data. The type can change depending on gdbarch, so it is
7198 also dependent on which thread you have selected.
7200 1. making $_siginfo be an internalvar that creates a new value on
7203 2. making the value of $_siginfo be an lval_computed value. */
7205 /* This function implements the lval_computed support for reading a
7209 siginfo_value_read (struct value *v)
7211 LONGEST transferred;
7213 validate_siginfo_access ();
7216 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
7218 value_contents_all_raw (v),
7220 TYPE_LENGTH (value_type (v)));
7222 if (transferred != TYPE_LENGTH (value_type (v)))
7223 error (_("Unable to read siginfo"));
7226 /* This function implements the lval_computed support for writing a
7230 siginfo_value_write (struct value *v, struct value *fromval)
7232 LONGEST transferred;
7234 validate_siginfo_access ();
7236 transferred = target_write (¤t_target,
7237 TARGET_OBJECT_SIGNAL_INFO,
7239 value_contents_all_raw (fromval),
7241 TYPE_LENGTH (value_type (fromval)));
7243 if (transferred != TYPE_LENGTH (value_type (fromval)))
7244 error (_("Unable to write siginfo"));
7247 static const struct lval_funcs siginfo_value_funcs =
7253 /* Return a new value with the correct type for the siginfo object of
7254 the current thread using architecture GDBARCH. Return a void value
7255 if there's no object available. */
7257 static struct value *
7258 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
7261 if (target_has_stack
7262 && !ptid_equal (inferior_ptid, null_ptid)
7263 && gdbarch_get_siginfo_type_p (gdbarch))
7265 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7267 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
7270 return allocate_value (builtin_type (gdbarch)->builtin_void);
7274 /* infcall_suspend_state contains state about the program itself like its
7275 registers and any signal it received when it last stopped.
7276 This state must be restored regardless of how the inferior function call
7277 ends (either successfully, or after it hits a breakpoint or signal)
7278 if the program is to properly continue where it left off. */
7280 struct infcall_suspend_state
7282 struct thread_suspend_state thread_suspend;
7283 #if 0 /* Currently unused and empty structures are not valid C. */
7284 struct inferior_suspend_state inferior_suspend;
7289 struct regcache *registers;
7291 /* Format of SIGINFO_DATA or NULL if it is not present. */
7292 struct gdbarch *siginfo_gdbarch;
7294 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
7295 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
7296 content would be invalid. */
7297 gdb_byte *siginfo_data;
7300 struct infcall_suspend_state *
7301 save_infcall_suspend_state (void)
7303 struct infcall_suspend_state *inf_state;
7304 struct thread_info *tp = inferior_thread ();
7306 struct inferior *inf = current_inferior ();
7308 struct regcache *regcache = get_current_regcache ();
7309 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7310 gdb_byte *siginfo_data = NULL;
7312 if (gdbarch_get_siginfo_type_p (gdbarch))
7314 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7315 size_t len = TYPE_LENGTH (type);
7316 struct cleanup *back_to;
7318 siginfo_data = xmalloc (len);
7319 back_to = make_cleanup (xfree, siginfo_data);
7321 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
7322 siginfo_data, 0, len) == len)
7323 discard_cleanups (back_to);
7326 /* Errors ignored. */
7327 do_cleanups (back_to);
7328 siginfo_data = NULL;
7332 inf_state = XCNEW (struct infcall_suspend_state);
7336 inf_state->siginfo_gdbarch = gdbarch;
7337 inf_state->siginfo_data = siginfo_data;
7340 inf_state->thread_suspend = tp->suspend;
7341 #if 0 /* Currently unused and empty structures are not valid C. */
7342 inf_state->inferior_suspend = inf->suspend;
7345 /* run_inferior_call will not use the signal due to its `proceed' call with
7346 GDB_SIGNAL_0 anyway. */
7347 tp->suspend.stop_signal = GDB_SIGNAL_0;
7349 inf_state->stop_pc = stop_pc;
7351 inf_state->registers = regcache_dup (regcache);
7356 /* Restore inferior session state to INF_STATE. */
7359 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
7361 struct thread_info *tp = inferior_thread ();
7363 struct inferior *inf = current_inferior ();
7365 struct regcache *regcache = get_current_regcache ();
7366 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7368 tp->suspend = inf_state->thread_suspend;
7369 #if 0 /* Currently unused and empty structures are not valid C. */
7370 inf->suspend = inf_state->inferior_suspend;
7373 stop_pc = inf_state->stop_pc;
7375 if (inf_state->siginfo_gdbarch == gdbarch)
7377 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7379 /* Errors ignored. */
7380 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
7381 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
7384 /* The inferior can be gone if the user types "print exit(0)"
7385 (and perhaps other times). */
7386 if (target_has_execution)
7387 /* NB: The register write goes through to the target. */
7388 regcache_cpy (regcache, inf_state->registers);
7390 discard_infcall_suspend_state (inf_state);
7394 do_restore_infcall_suspend_state_cleanup (void *state)
7396 restore_infcall_suspend_state (state);
7400 make_cleanup_restore_infcall_suspend_state
7401 (struct infcall_suspend_state *inf_state)
7403 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
7407 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
7409 regcache_xfree (inf_state->registers);
7410 xfree (inf_state->siginfo_data);
7415 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
7417 return inf_state->registers;
7420 /* infcall_control_state contains state regarding gdb's control of the
7421 inferior itself like stepping control. It also contains session state like
7422 the user's currently selected frame. */
7424 struct infcall_control_state
7426 struct thread_control_state thread_control;
7427 struct inferior_control_state inferior_control;
7430 enum stop_stack_kind stop_stack_dummy;
7431 int stopped_by_random_signal;
7432 int stop_after_trap;
7434 /* ID if the selected frame when the inferior function call was made. */
7435 struct frame_id selected_frame_id;
7438 /* Save all of the information associated with the inferior<==>gdb
7441 struct infcall_control_state *
7442 save_infcall_control_state (void)
7444 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
7445 struct thread_info *tp = inferior_thread ();
7446 struct inferior *inf = current_inferior ();
7448 inf_status->thread_control = tp->control;
7449 inf_status->inferior_control = inf->control;
7451 tp->control.step_resume_breakpoint = NULL;
7452 tp->control.exception_resume_breakpoint = NULL;
7454 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
7455 chain. If caller's caller is walking the chain, they'll be happier if we
7456 hand them back the original chain when restore_infcall_control_state is
7458 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
7461 inf_status->stop_stack_dummy = stop_stack_dummy;
7462 inf_status->stopped_by_random_signal = stopped_by_random_signal;
7463 inf_status->stop_after_trap = stop_after_trap;
7465 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
7471 restore_selected_frame (void *args)
7473 struct frame_id *fid = (struct frame_id *) args;
7474 struct frame_info *frame;
7476 frame = frame_find_by_id (*fid);
7478 /* If inf_status->selected_frame_id is NULL, there was no previously
7482 warning (_("Unable to restore previously selected frame."));
7486 select_frame (frame);
7491 /* Restore inferior session state to INF_STATUS. */
7494 restore_infcall_control_state (struct infcall_control_state *inf_status)
7496 struct thread_info *tp = inferior_thread ();
7497 struct inferior *inf = current_inferior ();
7499 if (tp->control.step_resume_breakpoint)
7500 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
7502 if (tp->control.exception_resume_breakpoint)
7503 tp->control.exception_resume_breakpoint->disposition
7504 = disp_del_at_next_stop;
7506 /* Handle the bpstat_copy of the chain. */
7507 bpstat_clear (&tp->control.stop_bpstat);
7509 tp->control = inf_status->thread_control;
7510 inf->control = inf_status->inferior_control;
7513 stop_stack_dummy = inf_status->stop_stack_dummy;
7514 stopped_by_random_signal = inf_status->stopped_by_random_signal;
7515 stop_after_trap = inf_status->stop_after_trap;
7517 if (target_has_stack)
7519 /* The point of catch_errors is that if the stack is clobbered,
7520 walking the stack might encounter a garbage pointer and
7521 error() trying to dereference it. */
7523 (restore_selected_frame, &inf_status->selected_frame_id,
7524 "Unable to restore previously selected frame:\n",
7525 RETURN_MASK_ERROR) == 0)
7526 /* Error in restoring the selected frame. Select the innermost
7528 select_frame (get_current_frame ());
7535 do_restore_infcall_control_state_cleanup (void *sts)
7537 restore_infcall_control_state (sts);
7541 make_cleanup_restore_infcall_control_state
7542 (struct infcall_control_state *inf_status)
7544 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
7548 discard_infcall_control_state (struct infcall_control_state *inf_status)
7550 if (inf_status->thread_control.step_resume_breakpoint)
7551 inf_status->thread_control.step_resume_breakpoint->disposition
7552 = disp_del_at_next_stop;
7554 if (inf_status->thread_control.exception_resume_breakpoint)
7555 inf_status->thread_control.exception_resume_breakpoint->disposition
7556 = disp_del_at_next_stop;
7558 /* See save_infcall_control_state for info on stop_bpstat. */
7559 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7564 /* restore_inferior_ptid() will be used by the cleanup machinery
7565 to restore the inferior_ptid value saved in a call to
7566 save_inferior_ptid(). */
7569 restore_inferior_ptid (void *arg)
7571 ptid_t *saved_ptid_ptr = arg;
7573 inferior_ptid = *saved_ptid_ptr;
7577 /* Save the value of inferior_ptid so that it may be restored by a
7578 later call to do_cleanups(). Returns the struct cleanup pointer
7579 needed for later doing the cleanup. */
7582 save_inferior_ptid (void)
7584 ptid_t *saved_ptid_ptr;
7586 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7587 *saved_ptid_ptr = inferior_ptid;
7588 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7594 clear_exit_convenience_vars (void)
7596 clear_internalvar (lookup_internalvar ("_exitsignal"));
7597 clear_internalvar (lookup_internalvar ("_exitcode"));
7601 /* User interface for reverse debugging:
7602 Set exec-direction / show exec-direction commands
7603 (returns error unless target implements to_set_exec_direction method). */
7605 int execution_direction = EXEC_FORWARD;
7606 static const char exec_forward[] = "forward";
7607 static const char exec_reverse[] = "reverse";
7608 static const char *exec_direction = exec_forward;
7609 static const char *const exec_direction_names[] = {
7616 set_exec_direction_func (char *args, int from_tty,
7617 struct cmd_list_element *cmd)
7619 if (target_can_execute_reverse)
7621 if (!strcmp (exec_direction, exec_forward))
7622 execution_direction = EXEC_FORWARD;
7623 else if (!strcmp (exec_direction, exec_reverse))
7624 execution_direction = EXEC_REVERSE;
7628 exec_direction = exec_forward;
7629 error (_("Target does not support this operation."));
7634 show_exec_direction_func (struct ui_file *out, int from_tty,
7635 struct cmd_list_element *cmd, const char *value)
7637 switch (execution_direction) {
7639 fprintf_filtered (out, _("Forward.\n"));
7642 fprintf_filtered (out, _("Reverse.\n"));
7645 internal_error (__FILE__, __LINE__,
7646 _("bogus execution_direction value: %d"),
7647 (int) execution_direction);
7652 show_schedule_multiple (struct ui_file *file, int from_tty,
7653 struct cmd_list_element *c, const char *value)
7655 fprintf_filtered (file, _("Resuming the execution of threads "
7656 "of all processes is %s.\n"), value);
7659 /* Implementation of `siginfo' variable. */
7661 static const struct internalvar_funcs siginfo_funcs =
7669 _initialize_infrun (void)
7673 struct cmd_list_element *c;
7675 add_info ("signals", signals_info, _("\
7676 What debugger does when program gets various signals.\n\
7677 Specify a signal as argument to print info on that signal only."));
7678 add_info_alias ("handle", "signals", 0);
7680 c = add_com ("handle", class_run, handle_command, _("\
7681 Specify how to handle signals.\n\
7682 Usage: handle SIGNAL [ACTIONS]\n\
7683 Args are signals and actions to apply to those signals.\n\
7684 If no actions are specified, the current settings for the specified signals\n\
7685 will be displayed instead.\n\
7687 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7688 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7689 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7690 The special arg \"all\" is recognized to mean all signals except those\n\
7691 used by the debugger, typically SIGTRAP and SIGINT.\n\
7693 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7694 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7695 Stop means reenter debugger if this signal happens (implies print).\n\
7696 Print means print a message if this signal happens.\n\
7697 Pass means let program see this signal; otherwise program doesn't know.\n\
7698 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7699 Pass and Stop may be combined.\n\
7701 Multiple signals may be specified. Signal numbers and signal names\n\
7702 may be interspersed with actions, with the actions being performed for\n\
7703 all signals cumulatively specified."));
7704 set_cmd_completer (c, handle_completer);
7708 add_com ("lz", class_info, signals_info, _("\
7709 What debugger does when program gets various signals.\n\
7710 Specify a signal as argument to print info on that signal only."));
7711 add_com ("z", class_run, xdb_handle_command, _("\
7712 Specify how to handle a signal.\n\
7713 Args are signals and actions to apply to those signals.\n\
7714 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7715 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7716 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7717 The special arg \"all\" is recognized to mean all signals except those\n\
7718 used by the debugger, typically SIGTRAP and SIGINT.\n\
7719 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7720 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7721 nopass), \"Q\" (noprint)\n\
7722 Stop means reenter debugger if this signal happens (implies print).\n\
7723 Print means print a message if this signal happens.\n\
7724 Pass means let program see this signal; otherwise program doesn't know.\n\
7725 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7726 Pass and Stop may be combined."));
7730 stop_command = add_cmd ("stop", class_obscure,
7731 not_just_help_class_command, _("\
7732 There is no `stop' command, but you can set a hook on `stop'.\n\
7733 This allows you to set a list of commands to be run each time execution\n\
7734 of the program stops."), &cmdlist);
7736 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7737 Set inferior debugging."), _("\
7738 Show inferior debugging."), _("\
7739 When non-zero, inferior specific debugging is enabled."),
7742 &setdebuglist, &showdebuglist);
7744 add_setshow_boolean_cmd ("displaced", class_maintenance,
7745 &debug_displaced, _("\
7746 Set displaced stepping debugging."), _("\
7747 Show displaced stepping debugging."), _("\
7748 When non-zero, displaced stepping specific debugging is enabled."),
7750 show_debug_displaced,
7751 &setdebuglist, &showdebuglist);
7753 add_setshow_boolean_cmd ("non-stop", no_class,
7755 Set whether gdb controls the inferior in non-stop mode."), _("\
7756 Show whether gdb controls the inferior in non-stop mode."), _("\
7757 When debugging a multi-threaded program and this setting is\n\
7758 off (the default, also called all-stop mode), when one thread stops\n\
7759 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7760 all other threads in the program while you interact with the thread of\n\
7761 interest. When you continue or step a thread, you can allow the other\n\
7762 threads to run, or have them remain stopped, but while you inspect any\n\
7763 thread's state, all threads stop.\n\
7765 In non-stop mode, when one thread stops, other threads can continue\n\
7766 to run freely. You'll be able to step each thread independently,\n\
7767 leave it stopped or free to run as needed."),
7773 numsigs = (int) GDB_SIGNAL_LAST;
7774 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7775 signal_print = (unsigned char *)
7776 xmalloc (sizeof (signal_print[0]) * numsigs);
7777 signal_program = (unsigned char *)
7778 xmalloc (sizeof (signal_program[0]) * numsigs);
7779 signal_catch = (unsigned char *)
7780 xmalloc (sizeof (signal_catch[0]) * numsigs);
7781 signal_pass = (unsigned char *)
7782 xmalloc (sizeof (signal_pass[0]) * numsigs);
7783 for (i = 0; i < numsigs; i++)
7786 signal_print[i] = 1;
7787 signal_program[i] = 1;
7788 signal_catch[i] = 0;
7791 /* Signals caused by debugger's own actions
7792 should not be given to the program afterwards. */
7793 signal_program[GDB_SIGNAL_TRAP] = 0;
7794 signal_program[GDB_SIGNAL_INT] = 0;
7796 /* Signals that are not errors should not normally enter the debugger. */
7797 signal_stop[GDB_SIGNAL_ALRM] = 0;
7798 signal_print[GDB_SIGNAL_ALRM] = 0;
7799 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7800 signal_print[GDB_SIGNAL_VTALRM] = 0;
7801 signal_stop[GDB_SIGNAL_PROF] = 0;
7802 signal_print[GDB_SIGNAL_PROF] = 0;
7803 signal_stop[GDB_SIGNAL_CHLD] = 0;
7804 signal_print[GDB_SIGNAL_CHLD] = 0;
7805 signal_stop[GDB_SIGNAL_IO] = 0;
7806 signal_print[GDB_SIGNAL_IO] = 0;
7807 signal_stop[GDB_SIGNAL_POLL] = 0;
7808 signal_print[GDB_SIGNAL_POLL] = 0;
7809 signal_stop[GDB_SIGNAL_URG] = 0;
7810 signal_print[GDB_SIGNAL_URG] = 0;
7811 signal_stop[GDB_SIGNAL_WINCH] = 0;
7812 signal_print[GDB_SIGNAL_WINCH] = 0;
7813 signal_stop[GDB_SIGNAL_PRIO] = 0;
7814 signal_print[GDB_SIGNAL_PRIO] = 0;
7816 /* These signals are used internally by user-level thread
7817 implementations. (See signal(5) on Solaris.) Like the above
7818 signals, a healthy program receives and handles them as part of
7819 its normal operation. */
7820 signal_stop[GDB_SIGNAL_LWP] = 0;
7821 signal_print[GDB_SIGNAL_LWP] = 0;
7822 signal_stop[GDB_SIGNAL_WAITING] = 0;
7823 signal_print[GDB_SIGNAL_WAITING] = 0;
7824 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7825 signal_print[GDB_SIGNAL_CANCEL] = 0;
7827 /* Update cached state. */
7828 signal_cache_update (-1);
7830 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7831 &stop_on_solib_events, _("\
7832 Set stopping for shared library events."), _("\
7833 Show stopping for shared library events."), _("\
7834 If nonzero, gdb will give control to the user when the dynamic linker\n\
7835 notifies gdb of shared library events. The most common event of interest\n\
7836 to the user would be loading/unloading of a new library."),
7837 set_stop_on_solib_events,
7838 show_stop_on_solib_events,
7839 &setlist, &showlist);
7841 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7842 follow_fork_mode_kind_names,
7843 &follow_fork_mode_string, _("\
7844 Set debugger response to a program call of fork or vfork."), _("\
7845 Show debugger response to a program call of fork or vfork."), _("\
7846 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7847 parent - the original process is debugged after a fork\n\
7848 child - the new process is debugged after a fork\n\
7849 The unfollowed process will continue to run.\n\
7850 By default, the debugger will follow the parent process."),
7852 show_follow_fork_mode_string,
7853 &setlist, &showlist);
7855 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7856 follow_exec_mode_names,
7857 &follow_exec_mode_string, _("\
7858 Set debugger response to a program call of exec."), _("\
7859 Show debugger response to a program call of exec."), _("\
7860 An exec call replaces the program image of a process.\n\
7862 follow-exec-mode can be:\n\
7864 new - the debugger creates a new inferior and rebinds the process\n\
7865 to this new inferior. The program the process was running before\n\
7866 the exec call can be restarted afterwards by restarting the original\n\
7869 same - the debugger keeps the process bound to the same inferior.\n\
7870 The new executable image replaces the previous executable loaded in\n\
7871 the inferior. Restarting the inferior after the exec call restarts\n\
7872 the executable the process was running after the exec call.\n\
7874 By default, the debugger will use the same inferior."),
7876 show_follow_exec_mode_string,
7877 &setlist, &showlist);
7879 add_setshow_enum_cmd ("scheduler-locking", class_run,
7880 scheduler_enums, &scheduler_mode, _("\
7881 Set mode for locking scheduler during execution."), _("\
7882 Show mode for locking scheduler during execution."), _("\
7883 off == no locking (threads may preempt at any time)\n\
7884 on == full locking (no thread except the current thread may run)\n\
7885 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
7886 In this mode, other threads may run during other commands."),
7887 set_schedlock_func, /* traps on target vector */
7888 show_scheduler_mode,
7889 &setlist, &showlist);
7891 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7892 Set mode for resuming threads of all processes."), _("\
7893 Show mode for resuming threads of all processes."), _("\
7894 When on, execution commands (such as 'continue' or 'next') resume all\n\
7895 threads of all processes. When off (which is the default), execution\n\
7896 commands only resume the threads of the current process. The set of\n\
7897 threads that are resumed is further refined by the scheduler-locking\n\
7898 mode (see help set scheduler-locking)."),
7900 show_schedule_multiple,
7901 &setlist, &showlist);
7903 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7904 Set mode of the step operation."), _("\
7905 Show mode of the step operation."), _("\
7906 When set, doing a step over a function without debug line information\n\
7907 will stop at the first instruction of that function. Otherwise, the\n\
7908 function is skipped and the step command stops at a different source line."),
7910 show_step_stop_if_no_debug,
7911 &setlist, &showlist);
7913 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7914 &can_use_displaced_stepping, _("\
7915 Set debugger's willingness to use displaced stepping."), _("\
7916 Show debugger's willingness to use displaced stepping."), _("\
7917 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7918 supported by the target architecture. If off, gdb will not use displaced\n\
7919 stepping to step over breakpoints, even if such is supported by the target\n\
7920 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7921 if the target architecture supports it and non-stop mode is active, but will not\n\
7922 use it in all-stop mode (see help set non-stop)."),
7924 show_can_use_displaced_stepping,
7925 &setlist, &showlist);
7927 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7928 &exec_direction, _("Set direction of execution.\n\
7929 Options are 'forward' or 'reverse'."),
7930 _("Show direction of execution (forward/reverse)."),
7931 _("Tells gdb whether to execute forward or backward."),
7932 set_exec_direction_func, show_exec_direction_func,
7933 &setlist, &showlist);
7935 /* Set/show detach-on-fork: user-settable mode. */
7937 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7938 Set whether gdb will detach the child of a fork."), _("\
7939 Show whether gdb will detach the child of a fork."), _("\
7940 Tells gdb whether to detach the child of a fork."),
7941 NULL, NULL, &setlist, &showlist);
7943 /* Set/show disable address space randomization mode. */
7945 add_setshow_boolean_cmd ("disable-randomization", class_support,
7946 &disable_randomization, _("\
7947 Set disabling of debuggee's virtual address space randomization."), _("\
7948 Show disabling of debuggee's virtual address space randomization."), _("\
7949 When this mode is on (which is the default), randomization of the virtual\n\
7950 address space is disabled. Standalone programs run with the randomization\n\
7951 enabled by default on some platforms."),
7952 &set_disable_randomization,
7953 &show_disable_randomization,
7954 &setlist, &showlist);
7956 /* ptid initializations */
7957 inferior_ptid = null_ptid;
7958 target_last_wait_ptid = minus_one_ptid;
7960 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7961 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7962 observer_attach_thread_exit (infrun_thread_thread_exit);
7963 observer_attach_inferior_exit (infrun_inferior_exit);
7965 /* Explicitly create without lookup, since that tries to create a
7966 value with a void typed value, and when we get here, gdbarch
7967 isn't initialized yet. At this point, we're quite sure there
7968 isn't another convenience variable of the same name. */
7969 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7971 add_setshow_boolean_cmd ("observer", no_class,
7972 &observer_mode_1, _("\
7973 Set whether gdb controls the inferior in observer mode."), _("\
7974 Show whether gdb controls the inferior in observer mode."), _("\
7975 In observer mode, GDB can get data from the inferior, but not\n\
7976 affect its execution. Registers and memory may not be changed,\n\
7977 breakpoints may not be set, and the program cannot be interrupted\n\